PHP Manual

Stig Sæther Bakken

Alexander Aulbach

Egon Schmid

Jim Winstead

Lars Torben Wilson

Rasmus Lerdorf

Andrei Zmievski

Jouni Ahto

Edited by

Stig Sæther Bakken

Egon Schmid

23-10-2002

Copyright

This manual can be redistributed under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

The 'Extending PHP 4.0' section of this manual is copyright © 2000 by Zend Technologies, Ltd. This material may be distributed only subject to the terms and conditions set forth in the Open Publication License, v1.0 or later (the latest version is presently available at http://www.opencontent.org/openpub/).

Table of Contents

Preface

I. Getting Started

1. Introduction
2. A simple tutorial
3. Installation
4. Configuration
5. Security

II. Language Reference

6. Basic syntax
7. Types
8. Variables
9. Constants
10. Expressions
11. Operators
12. Control Structures
13. Functions
14. Classes and Objects
15. References Explained

III. Features

16. HTTP authentication with PHP
17. Cookies
18. Handling file uploads
19. Using remote files
20. Connection handling
21. Persistent Database Connections
22. Safe Mode
23. Using PHP from the command line

IV. Function Reference

I. Apache-specific Functions
II. Array Functions
III. Aspell functions [deprecated]
IV. BCMath Arbitrary Precision Mathematics Functions
V. Bzip2 Compression Functions
VI. Calendar functions
VII. CCVS API Functions
VIII. COM support functions for Windows
IX. Class/Object Functions
X. ClibPDF functions
XI. Crack functions
XII. CURL, Client URL Library Functions
XIII. Cybercash payment functions
XIV. Crédit Mutuel CyberMUT functions
XV. Cyrus IMAP administration functions
XVI. Character type functions
XVII. Database (dbm-style) abstraction layer functions
XVIII. Date and Time functions
XIX. dBase functions
XX. DBM Functions
XXI. dbx functions
XXII. DB++ Functions
XXIII. Direct IO functions
XXIV. Directory functions
XXV. DOM XML functions
XXVI. .NET functions
XXVII. Error Handling and Logging Functions
XXVIII. FrontBase Functions
XXIX. filePro functions
XXX. Filesystem functions
XXXI. Forms Data Format functions
XXXII. FriBiDi functions
XXXIII. FTP functions
XXXIV. Function Handling functions
XXXV. Gettext
XXXVI. GMP functions
XXXVII. HTTP functions
XXXVIII. Hyperwave functions
XXXIX. Hyperwave API functions
XL. iconv functions
XLI. Image functions
XLII. IMAP, POP3 and NNTP functions
XLIII. Informix functions
XLIV. InterBase functions
XLV. Ingres II functions
XLVI. IRC Gateway Functions
XLVII. PHP / Java Integration
XLVIII. LDAP functions
XLIX. Mail functions
L. mailparse functions
LI. Mathematical Functions
LII. Multi-Byte String Functions
LIII. MCAL functions
LIV. Mcrypt Encryption Functions
LV. MCVE Payment Functions
LVI. Mhash Functions
LVII. Mimetype Functions
LVIII. Microsoft SQL Server functions
LIX. Ming functions for Flash
LX. Miscellaneous functions
LXI. mnoGoSearch Functions
LXII. mSQL functions
LXIII. MySQL Functions
LXIV. Mohawk Software session handler functions
LXV. muscat functions
LXVI. Network Functions
LXVII. Ncurses terminal screen control functions
LXVIII. Lotus Notes functions
LXIX. Unified ODBC functions
LXX. Object Aggregation/Composition Functions
LXXI. Oracle 8 functions
LXXII. OpenSSL functions
LXXIII. Oracle functions
LXXIV. Ovrimos SQL functions
LXXV. Output Control Functions
LXXVI. Object property and method call overloading
LXXVII. PDF functions
LXXVIII. Verisign Payflow Pro functions
LXXIX. PHP Options&Information
LXXX. POSIX functions
LXXXI. PostgreSQL functions
LXXXII. Process Control Functions
LXXXIII. Program Execution functions
LXXXIV. Printer functions
LXXXV. Pspell Functions
LXXXVI. GNU Readline
LXXXVII. GNU Recode functions
LXXXVIII. Regular Expression Functions (Perl-Compatible)
LXXXIX. qtdom functions
XC. Regular Expression Functions (POSIX Extended)
XCI. Semaphore, Shared Memory and IPC Functions
XCII. SESAM database functions
XCIII. Session handling functions
XCIV. Shared Memory Functions
XCV. Shockwave Flash functions
XCVI. SNMP functions
XCVII. Socket functions
XCVIII. String functions
XCIX. Sybase functions
C. Tokenizer functions
CI. URL Functions
CII. Variable Functions
CIII. vpopmail functions
CIV. W32api functions
CV. WDDX Functions
CVI. XML parser functions
CVII. XML-RPC functions
CVIII. XSLT functions
CIX. YAZ functions
CX. YP/NIS Functions
CXI. Zip File Functions (Read Only Access)
CXII. Zlib Compression Functions

V. Extending PHP 4.0

24. Overview
25. Extension Possibilities
26. Source Layout
27. PHP's Automatic Build System
28. Creating Extensions
29. Using Extensions
30. Troubleshooting
31. Source Discussion
32. Accepting Arguments
33. Creating Variables
34. Duplicating Variable Contents: The Copy Constructor
35. Returning Values
36. Printing Information
37. Startup and Shutdown Functions
38. Calling User Functions
39. Initialization File Support
40. Where to Go from Here
41. Reference: Some Configuration Macros
42. API Macros

43. Streams API for PHP Extension Authors

Overview
Streams Basics
Streams Common API Reference
Streams Dir API Reference
Streams File API Reference
Streams Socket API Reference
Streams Structures
Streams Constants

VI. FAQ: Frequently Asked Questions

44. General Information
45. Mailing lists
46. Obtaining PHP
47. Database issues
48. Installation
49. Build Problems
50. Using PHP
51. PHP and HTML
52. PHP and COM
53. PHP and other languages
54. Migrating from PHP 2 to PHP 3
55. Migrating from PHP 3 to PHP 4
56. Miscellaneous Questions

VII. Appendixes

A. History of PHP and related projects
B. Migrating from PHP 3 to PHP 4
C. Migrating from PHP/FI 2 to PHP 3
D. Debugging PHP
E. Extending PHP
F. List of Function Aliases
G. List of Reserved Words
H. List of Resource Types
I. List of Supported Protocols/Wrappers
J. List of Parser Tokens
K. About the manual
L. Missing Stuff

Preface

PHP, which stands for "PHP: Hypertext Preprocessor" is a widely-used Open Source general-purpose scripting language that is especially suited for Web development and can be embedded into HTML. Its syntax draws upon C, Java, and Perl, and is easy to learn. The main goal of the language is to allow web developers to write dynamically generated webpages quickly, but you can do much more with PHP.

This manual consists primarily of a function reference, but also contains a language reference, explanations of some of PHP's major features, and other supplemental information.

You can download this manual in several formats at http://www.php.net/docs.php. The downloads are updated as the content changes. More information about how this manual is developed can be found in the 'About the manual' appendix.

I. Getting Started

Table of Contents
1. Introduction
2. A simple tutorial
3. Installation
4. Configuration
5. Security

Chapter 1. Introduction

What is PHP?

PHP (recursive acronym for "PHP: Hypertext Preprocessor") is a widely-used Open Source general-purpose scripting language that is especially suited for Web development and can be embedded into HTML.

Simple answer, but what does that mean? An example:

Example 1-1. An introductory example
<html> <head> <title>Example</title> </head> <body> <?php echo "Hi, I'm a PHP script!"; ?> </body> </html>

Notice how this is different from a script written in other languages like Perl or C -- instead of writing a program with lots of commands to output HTML, you write an HTML script with some embedded code to do something (in this case, output some text). The PHP code is enclosed in special start and end tags that allow you to jump into and out of "PHP mode".

What distinguishes PHP from something like client-side JavaScript is that the code is executed on the server. If you were to have a script similar to the above on your server, the client would receive the results of running that script, with no way of determining what the underlying code may be. You can even configure your web server to process all your HTML files with PHP, and then there's really no way that users can tell what you have up your sleeve.

The best things in using PHP are that it is extremely simple for a newcomer, but offers many advanced features for a professional programmer. Don't be afraid reading the long list of PHP's features. You can jump in, in a short time, and start writing simple scripts in a few hours.

Although PHP's development is focused on server-side scripting, you can do much more with it. Read on, and see more in the What can PHP do? section.

What can PHP do?

Anything. PHP is mainly focused on server-side scripting, so you can do anything any other CGI program can do, such as collect form data, generate dynamic page content, or send and receive cookies. But PHP can do much more.

There are three main fields where PHP scripts are used.

Server-side scripting. This is the most traditional and main target field for PHP. You need three things to make this work. The PHP parser (CGI or server module), a webserver and a web browser. You need to run the webserver, with a connected PHP installation. You can access the PHP program output with a web browser, viewing the PHP page through the server. See the installation instructions section for more information.
Command line scripting. You can make a PHP script to run it without any server or browser. You only need the PHP parser to use it this way. This type of usage is ideal for scripts regularly executed using cron (on *nix or Linux) or Task Scheduler (on Windows). These scripts can also be used for simple text processing tasks. See the section about Command line usage of PHP for more information.
Writing client-side GUI applications. PHP is probably not the very best language to write windowing applications, but if you know PHP very well, and would like to use some advanced PHP features in your client-side applications you can also use PHP-GTK to write such programs. You also have the ability to write cross-platform applications this way. PHP-GTK is an extension to PHP, not available in the main distribution. If you are interested in PHP-GTK, visit it's own website.

PHP can be used on all major operating systems, including Linux, many Unix variants (including HP-UX, Solaris and OpenBSD), Microsoft Windows, Mac OS X, RISC OS, and probably others. PHP has also support for most of the web servers today. This includes Apache, Microsoft Internet Information Server, Personal Web Server, Netscape and iPlanet servers, Oreilly Website Pro server, Caudium, Xitami, OmniHTTPd, and many others. For the majority of the servers PHP has a module, for the others supporting the CGI standard, PHP can work as a CGI processor.

So with PHP, you have the freedom of choosing an operating system and a web server. Furthermore, you also have the choice of using procedural programming or object oriented programming, or a mixture of them. Although not every standard OOP feature is realized in the current version of PHP, many code libraries and large applications (including the PEAR library) are written only using OOP code.

With PHP you are not limited to output HTML. PHP's abilities includes outputting images, PDF files and even Flash movies (using libswf and Ming) generated on the fly. You can also output easily any text, such as XHTML and any other XML file. PHP can autogenerate these files, and save them in the file system, instead of printing it out, forming a server-side cache for your dynamic content.

One of the strongest and most significant feature in PHP is its support for a wide range of databases. Writing a database-enabled web page is incredibly simple. The following databases are currently supported:

Adabas D Ingres Oracle (OCI7 and OCI8)
dBase InterBase Ovrimos
Empress FrontBase PostgreSQL
FilePro (read-only) mSQL Solid
Hyperwave Direct MS-SQL Sybase
IBM DB2 MySQL Velocis
Informix ODBC Unix dbm

We also have a DBX database abstraction extension allowing you to transparently use any database supported by that extension. Additionally PHP supports ODBC, the Open Database Connection standard, so you can connect to any other database supporting this world standard.

PHP also has support for talking to other services using protocols such as LDAP, IMAP, SNMP, NNTP, POP3, HTTP, COM (on Windows) and countless others. You can also open raw network sockets and interact using any other protocol. PHP has support for the WDDX complex data exchange between virtually all Web programming languages. Talking about interconnection, PHP has support for instantiation of Java objects and using them transparently as PHP objects. You can also use our CORBA extension to access remote objects.

PHP has extremely useful text processing features, from the POSIX Extended or Perl regular expressions to parsing XML documents. For parsing and accessing XML documents, we support the SAX and DOM standards. You can use our XSLT extension to transform XML documents.

While using PHP in the ecommerce field, you'll find the Cybercash payment, CyberMUT, VeriSign Payflow Pro and CCVS functions useful for your online payment programs.

At last but not least, we have many other interesting extensions, the mnoGoSearch search engine functions, the IRC Gateway functions, many compression utilities (gzip, bz2), calendar conversion, translation...

As you can see this page is not enough to list all the features and benefits PHP can offer. Read on in the sections about installing PHP, and see the function reference part for explanation of the extensions mentioned here.

Chapter 2. A simple tutorial

Here we would like to show the very basics of PHP in a short simple tutorial. This text only deals with dynamic webpage creation with PHP, though PHP is not only capable of creating webpages. See the section titled What can PHP do for more information.

PHP-enabled web pages are treated just like regular HTML pages and you can create and edit them the same way you normally create regular HTML pages.

What do I need?

In this tutorial we assume that your server has support for PHP activated and that all files ending in .php are handled by PHP. On most servers this is the default extension for PHP files, but ask your server administrator to be sure. If your server supports PHP then you don't need to do anything. Just create your .php files and put them in your web directory and the server will magically parse them for you. There is no need to compile anything nor do you need to install any extra tools. Think of these PHP-enabled files as simple HTML files with a whole new family of magical tags that let you do all sorts of things.

Your first PHP-enabled page

Create a file named hello.php under your webserver root directory with the following content:

Example 2-1. Our first PHP script: hello.php
<html> <head> <title>PHP Test</title> </head> <body> <?php echo "Hello World<p>"; ?> </body> </html>
The output of this script will be:
<html> <head> <title>PHP Test</title> </head> <body> Hello World<p> </body> </html>

Note that this is not like a CGI script. The file does not need to be executable or special in any way. Think of it as a normal HTML file which happens to have a set of special tags available to you that do a lot of interesting things.

This program is extremely simple and you really didn't need to use PHP to create a page like this. All it does is display: Hello World using the PHP echo() statement.

If you tried this example and it didn't output anything, or it prompted for download, or you see the whole file as text, chances are that the server you are on does not have PHP enabled. Ask your administrator to enable it for you using the Installation chapter of the manual. If you want to develop PHP scripts locally, see the downloads section. You can develop locally on any Operating system, be sure to install an appropriate web server too.

The point of the example is to show the special PHP tag format. In this example we used <?php to indicate the start of a PHP tag. Then we put the PHP statement and left PHP mode by adding the closing tag, ?>. You may jump in and out of PHP mode in an HTML file like this all you want.

A Note on Text Editors: There are many text editors and Integrated Development Environments (IDEs) that you can use to create, edit and manage PHP files. A partial list of these tools is maintained at PHP Editor's List. If you wish to recommend an editor, please visit the above page and ask the page maintainer to add the editor to the list.

A Note on Word Processors: Word processors such as StarOffice Writer, Microsoft Word and Abiword are not good choices for editing PHP files.
If you wish to use one for this test script, you must ensure that you save the file as PLAIN TEXT or PHP will not be able to read and execute the script.

A Note on Windows Notepad: If you are writing your PHP scripts using Windows Notepad, you will need to ensure that your files are saved with the .php extension. (Notepad adds a .txt extension to files automatically unless you take one of the following steps to prevent it.)
When you save the file and are prompted to provide a name for the file, place the filename in quotes (i.e. "hello.php").
Alternately, you can click on the 'Text Documents' drop-down menu in the save dialog box and change the setting to "All Files". You can then enter your filename without quotes.

Something Useful

Let's do something a bit more useful now. We are going to check what sort of browser the person viewing the page is using. In order to do that we check the user agent string that the browser sends as part of its HTTP request. This information is stored in a variable. Variables always start with a dollar-sign in PHP. The variable we are interested in right now is $_SERVER["HTTP_USER_AGENT"].

PHP Autoglobals Note: $_SERVER is a special reserved PHP variable that contains all web server information. It's known as an Autoglobal (or Superglobal). See the related manual page on Autoglobals for more information. These special variables were introduced in PHP 4.1.0. Before this time, we used the older $HTTP_*_VARS arrays instead, such as $HTTP_SERVER_VARS. Although deprecated, these older variables still exist. (See also the note on old code.)

To display this variable, we can simply do:

Example 2-2. Printing a variable (Array element)
<?php echo $_SERVER["HTTP_USER_AGENT"]; ?>
A sample output of this script may be:
Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)

There are many types of variables available in PHP. In the above example we printed an Array element. Arrays can be very useful.

$_SERVER is just one variable that's automatically made available to you by PHP. A list can be seen in the Reserved Variables section of the manual or you can get a complete list of them by creating a file that looks like this:

Example 2-3. Show all predefined variables with phpinfo()
<?php phpinfo(); ?>

If you load up this file in your browser you will see a page full of information about PHP along with a list of all the variables available to you.

You can put multiple PHP statements inside a PHP tag and create little blocks of code that do more than just a single echo. For example, if we wanted to check for Internet Explorer we could do something like this:

Example 2-4. Example using control structures and functions
<?php if (strstr($_SERVER["HTTP_USER_AGENT"], "MSIE")) { echo "You are using Internet Explorer<br />"; } ?>
A sample output of this script may be:
You are using Internet Explorer<br />

Here we introduce a couple of new concepts. We have an if statement. If you are familiar with the basic syntax used by the C language this should look logical to you. If you don't know enough C or some other language where the syntax used above is used, you should probably pick up any introductory PHP book and read the first couple of chapters, or read the Language Reference part of the manual. You can find a list of PHP books at http://www.php.net/books.php.

The second concept we introduced was the strstr() function call. strstr() is a function built into PHP which searches a string for another string. In this case we are looking for "MSIE" inside $_SERVER["HTTP_USER_AGENT"]. If the string is found, the function returns TRUE and if it isn't, it returns FALSE. If it returns TRUE, the if statement evaluates to TRUE and the code within its {braces} is executed. Otherwise, it's not. Feel free to create similar examples, with if, else, and other functions such as strtoupper() and strlen(). Each related manual page contains examples too.

We can take this a step further and show how you can jump in and out of PHP mode even in the middle of a PHP block:

Example 2-5. Mixing both HTML and PHP modes
<?php if (strstr($_SERVER["HTTP_USER_AGENT"], "MSIE")) { ?> <h3>strstr must have returned true</h3> <center><b>You are using Internet Explorer</b></center> <?php } else { ?> <h3>strstr must have returned false</h3> <center><b>You are not using Internet Explorer</b></center> <?php } ?>
A sample output of this script may be:
<h3>strstr must have returned true</h3> <center><b>You are using Internet Explorer</b></center>

Instead of using a PHP echo statement to output something, we jumped out of PHP mode and just sent straight HTML. The important and powerful point to note here is that the logical flow of the script remains intact. Only one of the HTML blocks will end up getting sent to the viewer depending on if strstr() returned TRUE or FALSE In other words, if the string MSIE was found or not.

Dealing with Forms

One of the most powerful features of PHP is the way it handles HTML forms. The basic concept that is important to understand is that any form element in a form will automatically be available to your PHP scripts. Please read the manual section on Variables from outside of PHP for more information and examples on using forms with PHP. Here's an example HTML form:

Example 2-6. A simple HTML form
<form action="action.php" method="POST"> Your name: <input type="text" name="name" /> Your age: <input type="text" name="age" /> <input type="submit"> </form>

There is nothing special about this form. It is a straight HTML form with no special tags of any kind. When the user fills in this form and hits the submit button, the action.php page is called. In this file you would have something like this:

Example 2-7. Printing data from our form
Hi <?php echo $_POST["name"]; ?>. You are <?php echo $_POST["age"]; ?> years old.
A sample output of this script may be:
Hi Joe. You are 22 years old.

It should be obvious what this does. There is nothing more to it. The $_POST["name"] and $_POST["age"] variables are automatically set for you by PHP. Earlier we used the $_SERVER autoglobal, now above we just introduced the $_POST autoglobal which contains all POST data. Notice how the method of our form is POST. If we used the method GET then our form information would live in the $_GET autoglobal instead. You may also use the $_REQUEST autoglobal if you don't care the source of your request data. It contains a mix of GET, POST, COOKIE and FILE data. See also the import_request_variables() function.

Using old code with new versions of PHP

Now that PHP has grown to be a popular scripting language, there are more resources out there that have listings of code you can reuse in your own scripts. For the most part the developers of the PHP language have tried to be backwards compatible, so a script written for an older version should run (ideally) without changes in a newer version of PHP, in practice some changes will usually be needed.

Two of the most important recent changes that affect old code are:

The deprecation of the old $HTTP_*_VARS arrays (which need to be indicated as global when used inside a function or method). The following autoglobal arrays were introduced in PHP 4.1.0. They are: $_GET, $_POST, $_COOKIE, $_SERVER, $_ENV, $_REQUEST, and $_SESSION. The older $HTTP_*_VARS arrays, such as $HTTP_POST_VARS, still exist and have since PHP 3.
External variables are no longer registered in the global scope by default. In other words, as of PHP 4.2.0 the PHP directive register_globals is off by default in php.ini. The preferred method of accessing these values is via the autoglobal arrays mentioned above. Older scripts, books, and tutorials may rely on this directive being on. If on, for example, one could use $id from the URL http://www.example.com/foo.php?id=42. Whether on or off, $_GET['id'] is available.

For more details on these changes, see the section on predefined variables and links therein.

What's next?

With what you know now you should be able to understand most of the manual and also the various example scripts available in the example archives. You can also find other examples on the php.net websites in the links section: http://www.php.net/links.php.

Chapter 3. Installation

General Installation Considerations

Before installing first, you need to know what do you want to use PHP for. There are three main fields you can use PHP, as described in the What can PHP do? section:

Server-side scripting
Command line scripting
Client-side GUI applications

For the first and most common form, you need three things: PHP itself, a web server and a web browser. You probably already have a web browser, and depending on your operating system setup, you may also have a web server (eg. Apache on Linux or IIS on Windows). You may also rent webspace at a company. This way, you don't need to set up anything on your own, only write your PHP scripts, upload it to the server you rent, and see the results in your browser. You can find a list of hosting companies at http://hosts.php.net/.

While setting up the server and PHP on your own, you have two choices for the method of connecting PHP to the server. For many servers PHP has a direct module interface (also called SAPI). These servers include Apache, Microsoft Internet Information Server, Netscape and iPlanet servers. Many other servers have support for ISAPI, the Microsoft module interface (OmniHTTPd for example). If PHP has no module support for your web server, you can always use it as a CGI processor. This means you set up your server to use the command line executable of PHP (php.exe on Windows) to process all PHP file requests on the server.

If you are also interested to use PHP for command line scripting (eg. write scripts autogenerating some images for you offline, or processing text files depending on some arguments you pass to them), you always need the command line executable. For more information, read the section about writing command line PHP applications. In this case, you need no server and no browser.

With PHP you can also write client side GUI applications using the PHP-GTK extension. This is a completely different approach than writing web pages, as you do not output any HTML, but manage windows and objects within them. For more information about PHP-GTK, please visit the site dedicated to this extension. PHP-GTK is not included in the official PHP distribution.

From now on, this section deals with setting up PHP for web servers on Unix and Windows with server module interfaces and CGI executables.

Downloading PHP, the source code, and binary distributions for Windows can be found at http://www.php.net/. We recommend you to choose a mirror nearest to you for downloading the distributions.

Unix/HP-UX installs

This section contains notes and hints specific to installing PHP on HP-UX systems.

Example 3-1. Installation Instructions for HP-UX 10

From: paul_mckay@clearwater-it.co.uk
04-Jan-2001 09:49
(These tips are for PHP 4.0.4 and Apache v1.3.9) 

So you want to install PHP and Apache on a HP-UX 10.20 box? 

1. You need gzip, download a binary distribution from
http://hpux.connect.org.uk/ftp/hpux/Gnu/gzip-1.2.4a/gzip-1.2.4a-sd-10.20.depot.Z
uncompress the file and install using swinstall 

2. You need gcc, download a binary distribution from 
http://gatekeep.cs.utah.edu/ftp/hpux/Gnu/gcc-2.95.2/gcc-2.95.2-sd-10.20.depot.gz 
gunzip this file and install gcc using swinstall. 

3. You need the GNU binutils, you can download a binary distribution from 
http://hpux.connect.org.uk/ftp/hpux/Gnu/binutils-2.9.1/binutils-2.9.1-sd-10.20.depot.gz 
gunzip and install using swinstall. 

4. You now need bison, you can download a binary distribution from 
http://hpux.connect.org.uk/ftp/hpux/Gnu/bison-1.28/bison-1.28-sd-10.20.depot.gz 
install as above. 

5. You now need flex, you need to download the source from one of the
http://www.gnu.org mirrors. It is in the <filename>non-gnu</filename> directory of the ftp site. 
Download the file, gunzip, then tar -xvf it. Go into the newly created flex
directory and do a ./configure, then a make, and then a make install 

If you have errors here, it's probably because gcc etc. are not in your
PATH so add them to your PATH. 

Right, now into the hard stuff. 

6. Download the PHP and apache sources. 

7. gunzip and tar -xvf them. 

We need to hack a couple of files so that they can compile ok. 

8. Firstly the configure file needs to be hacked because it seems to lose
track of the fact that you are a hpux machine, there will be a
better way of doing this but a cheap and cheerful hack is to put 
    lt_target=hpux10.20 
on line 47286 of the configure script. 

9. Next, the Apache GuessOS file needs to be hacked. Under
apache_1.3.9/src/helpers change line 89 from 
    "echo "hp${HPUXMACH}-hpux${HPUXVER}"; exit 0" 
to: 
    "echo "hp${HPUXMACH}-hp-hpux${HPUXVER}"; exit 0" 
    
10. You cannot install PHP as a shared object under HP-UX so you must compile
it as a static, just follow the instructions at the Apache page. 

11. PHP and apache should have compiled OK, but Apache won't start. you need
to create a new user for Apache, eg www, or apache. You then change lines 252
and 253 of the conf/httpd.conf in Apache so that instead of 
    User nobody 
    Group nogroup 
you have something like 
    User www 
    Group sys 

This is because you can't run Apache as nobody under hp-ux. 
Apache and PHP should then work. 

Hope this helps somebody,
Paul Mckay.

Unix/Linux installs

This section contains notes and hints specific to installing PHP on Linux distributions.

Using Packages

Many Linux distributions have some sort of package installation system, such as RPM. This can assist in setting up a standard configuration, but if you need to have a different set of features (such as a secure server, or a different database driver), you may need to build PHP and/or your webserver. If you are unfamiliar with building and compiling your own software, it is worth checking to see whether somebody has already built a packaged version of PHP with the features you need.

Unix/Mac OS X installs

This section contains notes and hints specific to installing PHP on Mac OS X Server.

Using Packages

There are a few pre-packaged and pre-compiled versions of PHP for Mac OS X. This can help in setting up a standard configuration, but if you need to have a different set of features (such as a secure server, or a different database driver), you may need to build PHP and/or your web server yourself. If you are unfamiliar with building and compiling your own software, it's worth checking whether somebody has already built a packaged version of PHP with the features you need.

Compiling for OS X server

There are two slightly different versions of Mac OS X, client and server. The following is for OS X Server.

Example 3-2. Mac OS X server install

1. Get the latest distributions of Apache and PHP
2. Untar them, and run the configure program on Apache like so.
    ./configure --exec-prefix=/usr \ 
    --localstatedir=/var \ 
    --mandir=/usr/share/man \ 
    --libexecdir=/System/Library/Apache/Modules \ 
    --iconsdir=/System/Library/Apache/Icons \ 
    --includedir=/System/Library/Frameworks/Apache.framework/Versions/1.3/Headers \ 
    --enable-shared=max \ 
    --enable-module=most \ 
    --target=apache 

4. You may also want to add this line: 
    setenv OPTIM=-O2 
    If you want the compiler to do some optimization. 
    
5. Next, go to the PHP 4 source directory and configure it. 
    ./configure --prefix=/usr \ 
    --sysconfdir=/etc \ 
    --localstatedir=/var \ 
    --mandir=/usr/share/man \ 
    --with-xml \ 
    --with-apache=/src/apache_1.3.12 

    If you have any other additions (MySQL, GD, etc.), be sure to add
    them here. For the --with-apache string, put in the path to your 
    apache source directory, for example "/src/apache_1.3.12". 
6. make
7. make install    
    This will add a directory to your Apache source directory under
    src/modules/php4.
    
8. Now, reconfigure Apache to build in PHP 4.
    ./configure --exec-prefix=/usr \ 
    --localstatedir=/var \ 
    --mandir=/usr/share/man \ 
    --libexecdir=/System/Library/Apache/Modules \ 
    --iconsdir=/System/Library/Apache/Icons \ 
    --includedir=/System/Library/Frameworks/Apache.framework/Versions/1.3/Headers \ 
    --enable-shared=max \ 
    --enable-module=most \ 
    --target=apache \ 
    --activate-module=src/modules/php4/libphp4.a 

    You may get a message telling you that libmodphp4.a is out of date.
    If so, go to the src/modules/php4 directory inside your apache
    source directory and run this command: 

    ranlib libmodphp4.a 

    Then go back to the root of the apache source directory and run the
    above configure command again. That'll bring the link table up to
    date. 

9. make

10. make install

11. copy and rename the php.ini-dist file to your "bin" directory from your
    PHP 4 source directory:
    cp php.ini-dist /usr/local/bin/php.ini 

    or (if your don't have a local directory) 

    cp php.ini-dist /usr/bin/php.ini

Other examples for Mac OS X client and Mac OS X server are available at Stepwise.

Compiling for MacOS X client

Those tips are graciously provided by Marc Liyanage.

The PHP module for the Apache web server included in Mac OS X. This version includes support for the MySQL and PostgreSQL databases.

NOTE: Be careful when you do this, you could screw up your Apache web server!

Do this to install:

1. Open a terminal window
2. Type "wget http://www.diax.ch/users/liyanage/software/macosx/libphp4.so.gz", wait for download to finish
3. Type "gunzip libphp4.so.gz"
4. Type "sudo apxs -i -a -n php4 libphp4.so"

Now type "sudo open -a TextEdit /etc/httpd/httpd.conf" TextEdit will open with the web server configuration file. Locate these two lines towards the end of the file: (Use the Find command)

#AddType application/x-httpd-php .php 
   #AddType application/x-httpd-php-source .phps

Remove the two hash marks (#), then save the file and quit TextEdit.

Finally, type "sudo apachectl graceful" to restart the web server.

PHP should now be up and running. You can test it by dropping a file into your "Sites" folder which is called "test.php". Into that file, write this line: "<?php phpinfo() ?>".

Now open up 127.0.0.1/~your_username/test.php in your web browser. You should see a status table with information about the PHP module.

Unix/OpenBSD installs

This section contains notes and hints specific to installing PHP on OpenBSD.

Using Ports

This is the recommended method of installing PHP on OpenBSD, as it will have the latest patches and security fixes applied to it by the maintainers. To use this method, ensure that you have a recent ports tree. Then simply find out which flavors you wish to install, and issue the make install command. Below is an example of how to do this.

Example 3-3. OpenBSD Ports Install Example

$ cd /usr/ports/www/php4
$ make show VARNAME=FLAVORS
 (choose which flavors you want from the list)
$ env FLAVOR="imap gettext ldap mysql gd" make install
$ /usr/local/sbin/php4-enable

Using Packages

There are pre-compiled packages available for your release of OpenBSD. These integrate automatically with the version of Apache installed with the OS. However, since there are a large number of options (called flavors) available for this port, you may find it easier to compile it from source using the ports tree. Read the packages(7) manual page for more information in what packages are available.

Unix/Solaris installs

This section contains notes and hints specific to installing PHP on Solaris systems.

Required software

Solaris installs often lack C compilers and their related tools. The required software is as follows:

gcc (recommended, other C compilers may work)
make
flex
bison
m4
autoconf
automake
perl
gzip
tar

In addition, you will need to install (and possibly compile) any additional software specific to your configuration, such as Oracle or MySQL.

Using Packages

You can simplify the Solaris install process by using pkgadd to install most of your needed components.

Installation on UNIX systems

This section will guide you through the general configuration and installation of PHP on Unix systems. Be sure to investigate any sections specific to your platform or web server before you begin the process.

Prerequisite knowledge and software:

Basic UNIX skills (being able to operate "make" and a C compiler, if compiling)
An ANSI C compiler (if compiling)
flex (for compiling)
bison (for compiling)
A web server
Any module specific components (such as gd, pdf libs, etc.)

There are several ways to install PHP for the Unix platform, either with a compile and configure process, or through various pre-packaged methods. This documentation is mainly focused around the process of compiling and configuring PHP.

The initial PHP setup and configuration process is controlled by the use of the commandline options of the configure script. This page outlines the usage of the most common options, but there are many others to play with. Check out the Complete list of configure options for an exhaustive rundown. There are several ways to install PHP:

As an Apache module
As an fhttpd module
For use with AOLServer, NSAPI, phttpd, Pi3Web, Roxen, thttpd, or Zeus.
As a CGI executable

Apache Module Quick Reference

PHP can be compiled in a number of different ways, but one of the most popular is as an Apache module. The following is a quick installation overview.

Example 3-4. Quick Installation Instructions for PHP 4 (Apache Module Version)

1.  gunzip apache_1.3.x.tar.gz
2.  tar xvf apache_1.3.x.tar
3.  gunzip php-x.x.x.tar.gz
4.  tar xvf php-x.x.x.tar
5.  cd apache_1.3.x
6.  ./configure --prefix=/www
7.  cd ../php-x.x.x
8.  ./configure --with-mysql --with-apache=../apache_1.3.x --enable-track-vars
9.  make
10. make install
11. cd ../apache_1.3.x
12. ./configure --activate-module=src/modules/php4/libphp4.a
13. make
14. make install
15. cd ../php-x.x.x
16. cp php.ini-dist /usr/local/lib/php.ini
17. Edit your httpd.conf or srm.conf file and add: 
      AddType application/x-httpd-php .php

18. Use your normal procedure for restarting the Apache server. (You must
    stop and restart the server, not just cause the server to reload by
    use a HUP or USR1 signal.)

Building

When PHP is configured, you are ready to build the CGI executable. The command make should take care of this. If it fails and you can't figure out why, see the Problems section.

Installation on Windows systems

This section applies to Windows 95/98/Me and Windows NT/2000/XP. Do not expect PHP to work on 16 bit platforms such as Windows 3.1. Sometimes we refer to the supported Windows platforms as Win32.

There are two main ways to install PHP for Windows: either manually or by using the InstallShield installer.

If you have Microsoft Visual Studio, you can also build PHP from the original source code.

Once you have PHP installed on your Windows system, you may also want to load various extensions for added functionality.

Windows InstallShield

The Windows PHP installer available from the downloads page at http://www.php.net/, this installs the CGI version of PHP and, for IIS, PWS, and Xitami, configures the web server as well. Also note, that while the InstallShield installer is an easy way to make PHP work, it is restricted in many aspects, as automatic setup of extensions for example is not supported.

Install your selected HTTP server on your system and make sure that it works.

Run the executable installer and follow the instructions provided by the installation wizard. Two types of installation are supported - standard, which provides sensible defaults for all the settings it can, and advanced, which asks questions as it goes along.

The installation wizard gathers enough information to set up the php.ini file and configure the web server to use PHP. For IIS and also PWS on NT Workstation, a list of all the nodes on the server with script map settings is displayed, and you can choose those nodes to which you wish to add the PHP script mappings.

Once the installation has completed the installer will inform you if you need to restart your system, restart the server, or just start using PHP.

Warning

Be aware, that this setup of PHP is not secure. If you would like to have a secure PHP setup, you'd better go on the manual way, and set every option carefully. This automatically working setup gives you an instantly working PHP installation, but it is not meant to be used on online servers.

Manual Installation Steps

This install guide will help you manually install and configure PHP on your Windows webserver. You need to download the zip binary distribution from the downloads page at http://www.php.net/. The original version of this guide was compiled by Bob Silva, and can be found at http://www.umesd.k12.or.us/php/win32install.html.

This guide provides manual installation support for:

Personal Web Server 3 and 4 or newer
Internet Information Server 3 and 4 or newer
Apache 1.3.x
OmniHTTPd 2.0b1 and up
Oreilly Website Pro
Xitami
Netscape Enterprise Server, iPlanet

PHP 4 for Windows comes in two flavours - a CGI executable (php.exe), and several SAPI modules (for example: php4isapi.dll). The latter form is new to PHP 4, and provides significantly improved performance and some new functionality.

Warning

The SAPI modules have been significantly improved in the 4.1 release, however, you may find that you encounter possible server errors or other server modules such as ASP failing, in older systems.

If you choose one of the SAPI modules and use Windows 95, be sure to download the DCOM update from the Microsoft DCOM pages. For the ISAPI module, an ISAPI 4.0 compliant Web server is required (tested on IIS 4.0, PWS 4.0 and IIS 5.0). IIS 3.0 is NOT supported. You should download and install the Windows NT 4.0 Option Pack with IIS 4.0 if you want native PHP support.

The following steps should be performed on all installations before the server specific instructions.

Extract the distribution file to a directory of your choice. c:\php\ is a good start. You probably do not want to use a path in which spaces are included (for example: c:\program files\php is not a good idea). Some web servers will crash if you do.

You need to ensure that the DLLs which PHP uses can be found. The precise DLLs involved depend on which web server you use and whether you want to run PHP as a CGI or as a server module. php4ts.dll is always used. If you are using a server module (e.g. ISAPI or Apache) then you will need the relevant DLL from the sapi folder. If you are using any PHP extension DLLs then you will need those as well. To make sure that the DLLs can be found, you can either copy them to the system directory (e.g. winnt/system32 or windows/system) or you can make sure that they live in the same directory as the main PHP executable or DLL your web server will use (e.g. php.exe, php4apache.dll).

The PHP binary, the SAPI modules, and some extensions rely on external DLLs for execution. Make sure that these DLLs in the distribution exist in a directory that is in the Windows PATH. The best bet to do it is to copy the files below into your system directory, which is typically:

c:\windows\system for Windows 9x/ME

c:\winnt\system32 for Windows NT/2000

c:\windows\system32 for Windows XP

The files to copy are:

php4ts.dll, if it already exists there, overwrite it

The files in your distribution's 'dlls' directory. If you have them already installed on your system, overwrite them only if something doesn't work correctly (Before overwriting them, it is a good idea to make a backup of them, or move them to another folder - just in case something goes wrong).

Download the latest version of the Microsoft Data Access Components (MDAC) for your platform, especially if you use Microsoft Windows 9x/NT4. MDAC is available at http://www.microsoft.com/data/.

Copy your chosen ini file (see below) to your '%WINDOWS%' directory on Windows 9x/Me or to your '%SYSTEMROOT%' directory under Windows NT/2000/XP and rename it to php.ini. Your '%WINDOWS%' or '%SYSTEMROOT%' directory is typically:
c:\windows for Windows 9x/ME/XP
c:\winnt or c:\winnt40 for NT/2000 servers

There are two ini files distributed in the zip file, php.ini-dist and php.ini-optimized. We advise you to use php.ini-optimized, because we optimized the default settings in this file for performance, and security. The best is to study all the ini settings and set every element manually yourself. If you would like to achieve the best security, then this is the way for you, although PHP works fine with these default ini files.
Edit your new php.ini file:
- You will need to change the 'extension_dir' setting to point to your php-install-dir, or where you have placed your php_*.dll files. Please do not forget the last backslash. ex: c:\php\extensions\
- If you are using OmniHTTPd, do not follow the next step. Set the 'doc_root' to point to your webservers document_root. For example: c:\apache\htdocs or c:\webroot
- Choose which extensions you would like to load when PHP starts. See the section about Windows extensions, about how to set up one, and what is already built in. Note that on a new installation it is advisable to first get PHP working and tested without any extensions before enabling them in php.ini.
- On PWS and IIS, you can set the browscap.ini to point to: c:\windows\system\inetsrv\browscap.ini on Windows 9x/Me, c:\winnt\system32\inetsrv\browscap.ini on NT/2000, and c:\windows\system32\inetsrv\browscap.ini on XP.
- Note that the mibs directory supplied with the Windows distribution contains support files for SNMP. This directory should be moved to DRIVE:\usr\mibs (DRIVE being the drive where PHP is installed.)
- If you're using NTFS on Windows NT, 2000 or XP, make sure that the user running the webserver has read permissions to your php.ini (e.g. make it readable by Everyone).
For PWS give execution permission to the webroot:
- Start PWS Web Manager
- Edit Properties of the "Home"-Directory
- Select the "execute"-Checkbox

Building from source

Before getting started, it is worthwhile answering the question: "Why is building on Windows so hard?" Two reasons come to mind:

Windows does not (yet) enjoy a large community of developers who are willing to freely share their source. As a direct result, the necessary investment in infrastructure required to support such development hasn't been made. By and large, what is available has been made possible by the porting of necessary utilities from Unix. Don't be surprised if some of this heritage shows through from time to time.
Pretty much all of the instructions that follow are of the "set and forget" variety. So sit back and try follow the instructions below as faithfully as you can.

Preparations

Before you get started, you have a lot to download...

For starters, get the Cygwin toolkit from the closest cygwin mirror site. This will provide you most of the popular GNU utilities used by the build process.
Download the rest of the build tools you will need from the PHP site at http://www.php.net/extra/win32build.zip.
Get the source code for the DNS name resolver used by PHP at http://www.php.net/extra/bindlib_w32.zip. This is a replacement for the resolv.lib library included in win32build.zip.
If you don't already have an unzip utility, you will need one. A free version is available from InfoZip.
If you plan to compile PHP as a static Apache module you will also need the Apache sources of your version of Apache.

Finally, you are going to need the source to PHP 4 itself. You can get the latest development version using anonymous CVS. If you get a snapshot or a source tarball, you not only will have to untar and ungzip it, but you will have to convert the bare linefeeds to crlf's in the *.dsp and *.dsw files before Microsoft Visual C++ will have anything to do with them.

Note: Place the Zend and TSRM directories inside the php4 directory in order for the projects to be found during the build process.

Putting it all together

Follow the instructions for installing the unzip utility of your choosing.
Execute setup.exe and follow the installation instructions. If you choose to install to a path other than c:\cygnus, let the build process know by setting the Cygwin environment variable. On Windows 95/98 setting an environment variable can be done by placing a line in your autoexec.bat. On Windows NT, go to My Computer => Control Panel => System and select the environment tab.

Warning

Make a temporary directory for Cygwin to use, otherwise many commands (particularly bison) will fail. On Windows 95/98, mkdir C:\TMP. For Windows NT, mkdir %SystemDrive%\tmp.

Make a directory and unzip win32build.zip into it.
Launch Microsoft Visual C++, and from the menu select Tools => Options. In the dialog, select the directories tab. Sequentially change the dropdown to Executables, Includes, and Library files, and ensure that cygwin\bin, win32build\include, and win32build\lib are in each list, respectively. (To add an entry, select a blank line at the end of the list and begin typing). Typical entries will look like this:
- c:\cygnus\bin
- c:\php-win32build\include
- c:\php-win32build\lib
Press OK, and exit out of Visual C++.
Make another directory and unzip bindlib_w32.zip into it. Decide whether you want to have debug symbols available (bindlib - Win32 Debug) or not (bindlib - Win32 Release). Build the appropriate configuration:
- For GUI users, launch VC++, and then select File => Open Workspace and select bindlib. Then select Build=>Set Active Configuration and select the desired configuration. Finally select Build=>Rebuild All.
- For command line users, make sure that you either have the C++ environment variables registered, or have run vcvars.bat, and then execute one of the following:
  - msdev bindlib.dsp /MAKE "bindlib - Win32 Debug"
  - msdev bindlib.dsp /MAKE "bindlib - Win32 Release"
- At this point, you should have a usable resolv.lib in either your Debug or Release subdirectories. Copy this file into your win32build\lib directory over the file by the same name found in there.

Compiling

The best way to get started is to build the standalone/CGI version.

For GUI users, launch VC++, and then select File => Open Workspace and select php4ts. Then select Build=>Set Active Configuration and select the desired configuration. Finally select Build=>Rebuild All.
For command line users, make sure that you either have the C++ environment variables registered, or have run vcvars.bat, and then execute one of the following:
- msdev php4ts.dsp /MAKE "php4ts - Win32 Debug_TS"
- msdev php4ts.dsp /MAKE "php4ts - Win32 Release_TS"
- At this point, you should have a usable php.exe in either your Debug_TS or Release_TS subdirectories.

Repeat the above steps with php4isapi.dsp (which can be found in sapi\isapi) in order to build the code necessary for integrating PHP with Microsoft IIS.

It is possible to do minor customization to the build process by editing the main/config.win32.h.in file.

Installation of Windows extensions

After installing PHP and a webserver on Windows, you will probably want to install some extensions for added functionality. The following table describes some of the extensions available. You can choose which extensions you would like to load when PHP starts by uncommenting the: 'extension=php_*.dll' lines in php.ini. You can also load a module dynamically in your script using dl().

The DLLs for PHP extensions are prefixed with 'php_' in PHP 4 (and 'php3_' in PHP 3). This prevents confusion between PHP extensions and their supporting libraries.

Note: In PHP 4.0.6 BCMath, Calendar, COM, FTP, MySQL, ODBC, PCRE, Session, WDDX and XML support is built in. You don't need to load any additional extensions in order to use these functions. See your distributions README.txt or install.txt for a list of built in modules.

Note: Some of these extensions need extra DLLs to work. Couple of them can be found in the distribution package, in the 'dlls' folder but some, for example Oracle (php_oci8.dll) require DLLs which are not bundled with the distribution package.
Copy the bundled DLLs from 'DLLs' folder to your Windows PATH, safe places are:
c:\windows\system for Windows 9x/Me
c:\winnt\system32 for Windows NT/2000
c:\windows\system32 for Windows XP
If you have them already installed on your system, overwrite them only if something doesn't work correctly (Before overwriting them, it is a good idea to make a backup of them, or move them to another folder - just in case something goes wrong).

Table 3-1. PHP Extensions

Extension	Description	Notes
php_bz2.dll	bzip2 compression functions	None
php_calendar.dll	Calendar conversion functions	Built in since PHP 4.0.3
php_cpdf.dll	ClibPDF functions	None
php_crack.dll	Crack functions	None
php3_crypt.dll	Crypt functions	unknown
php_ctype.dll	ctype family functions	None
php_curl.dll	CURL, Client URL library functions	Requires: libeay32.dll, ssleay32.dll (bundled)
php_cybercash.dll	Cybercash payment functions	None
php_db.dll	DBM functions	Deprecated. Use DBA instead (php_dba.dll)
php_dba.dll	DBA: DataBase (dbm-style) Abstraction layer functions	None
php_dbase.dll	dBase functions	None
php3_dbm.dll	Berkeley DB2 library	unknown
php_domxml.dll	DOM XML functions	Requires: libxml2.dll (bundled)
php_dotnet.dll	.NET functions	None
php_exif.dll	Read EXIF headers from JPEG	None
php_fbsql.dll	FrontBase functions	None
php_fdf.dll	FDF: Forms Data Format functions.	Requires: fdftk.dll (bundled)
php_filepro.dll	filePro functions	Read-only access
php_ftp.dll	FTP functions	Built-in since PHP 4.0.3
php_gd.dll	GD library image functions	None
php_gettext.dll	Gettext functions	Requires: gnu_gettext.dll (bundled)
php_hyperwave.dll	HyperWave functions	None
php_iconv.dll	ICONV characterset conversion	Requires: iconv-1.3.dll (bundled)
php_ifx.dll	Informix functions	Requires: Informix libraries
php_iisfunc.dll	IIS management functions	None
php_imap.dll	IMAP POP3 and NNTP functions	PHP 3: php3_imap4r1.dll
php_ingres.dll	Ingres II functions	Requires: Ingres II libraries
php_interbase.dll	InterBase functions	Requires: gds32.dll (bundled)
php_java.dll	Java extension	Requires: jvm.dll (bundled)
php_ldap.dll	LDAP functions	Requires: libsasl.dll (bundled)
php_mhash.dll	Mhash Functions	None
php_ming.dll	Ming functions for Flash	None
php_msql.dll	mSQL functions	Requires: msql.dll (bundled)
php3_msql1.dll	mSQL 1 client	unknown
php3_msql2.dll	mSQL 2 client	unknown
php_mssql.dll	MSSQL functions	Requires: ntwdblib.dll (bundled)
php3_mysql.dll	MySQL functions	Built-in in PHP 4
php3_nsmail.dll	Netscape mail functions	unknown
php3_oci73.dll	Oracle functions	unknown
php_oci8.dll	Oracle 8 functions	Requires: Oracle 8 client libraries
php_openssl.dll	OpenSSL functions	Requires: libeay32.dll (bundled)
php_oracle.dll	Oracle functions	Requires: Oracle 7 client libraries
php_pdf.dll	PDF functions	None
php_pgsql.dll	PostgreSQL functions	None
php_printer.dll	Printer functions	None
php_xslt.dll	XSLT functions	Requires: sablot.dll (bundled)
php_snmp.dll	SNMP get and walk functions	NT only!
php_sybase_ct.dll	Sybase functions	Requires: Sybase client libraries
php_yaz.dll	YAZ functions	None
php_zlib.dll	ZLib compression functions	None

Servers-CGI/Commandline

The default is to build PHP as a CGI program. This creates a commandline interpreter, which can be used for CGI processing, or for non-web-related PHP scripting. If you are running a web server PHP has module support for, you should generally go for that solution for performance reasons. However, the CGI version enables Apache users to run different PHP-enabled pages under different user-ids. Please make sure you read through the Security chapter if you are going to run PHP as a CGI.

Testing

If you have built PHP as a CGI program, you may test your build by typing make test. It is always a good idea to test your build. This way you may catch a problem with PHP on your platform early instead of having to struggle with it later.

Benchmarking

If you have built PHP 3 as a CGI program, you may benchmark your build by typing make bench. Note that if Safe Mode is on by default, the benchmark may not be able to finish if it takes longer then the 30 seconds allowed. This is because the set_time_limit() can not be used in safe mode. Use the max_execution_time configuration setting to control this time for your own scripts. make bench ignores the configuration file.

Note: make bench is only available for PHP 3.

Using Variables

Some server supplied enviroment variables are not defined in the current CGI/1.1 specification. Only the following variables are defined there; everything else should be treated as 'vendor extensions': AUTH_TYPE, CONTENT_LENGTH, CONTENT_TYPE, GATEWAY_INTERFACE, PATH_INFO, PATH_TRANSLATED, QUERY_STRING, REMOTE_ADDR, REMOTE_HOST, REMOTE_IDENT, REMOTE_USER, REQUEST_METHOD, SCRIPT_NAME, SERVER_NAME, SERVER_PORT, SERVER_PROTOCOL and SERVER_SOFTWARE

Servers-Apache

This section contains notes and hints specific to Apache installs of PHP, both for Unix and Windows versions.

Details of installing PHP with Apache on Unix

You can select arguments to add to the configure on line 10 below from the Complete list of configure options. The version numbers have been omitted here, to ensure the instructions are not incorrect. You will need to replace the 'xxx' here with the correct values from your files.

Example 3-5. Installation Instructions (Apache Shared Module Version) for PHP 4

1.  gunzip apache_xxx.tar.gz
2.  tar -xvf apache_xxx.tar
3.  gunzip php-xxx.tar.gz
4.  tar -xvf php-xxx.tar
5.  cd apache_xxx
6.  ./configure --prefix=/www --enable-module=so
7.  make
8.  make install
9.  cd ../php-xxx
10. ./configure --with-mysql --with-apxs=/www/bin/apxs
11. make
12. make install

  If you decide to change your configure options after installation
  you only need to repeat the last three steps. You only need to 
  restart apache for the new module to take effect. A recompile of
  Apache is not needed.

13. cp php.ini-dist /usr/local/lib/php.ini

  You can edit your .ini file to set PHP options.  If
  you prefer this file in another location, use
  --with-config-file-path=/path in step 10.

14. Edit your httpd.conf or srm.conf file and check that these lines are
    present and not commented out:
  
   AddType application/x-httpd-php .php

   LoadModule php4_module        libexec/libphp4.so
 
  You can choose any extension you wish here.  .php is simply the one
  we suggest. You can even include .html, and .php3 can be added for 
  backwards compatibility.
 
  The path on the right hand side of the LoadModule statement must point
  to the path of the PHP module on your system. The above statement is 
  correct for the steps shown above.


15. Use your normal procedure for starting the Apache server. (You must
    stop and restart the server, not just cause the server to reload by
    use a HUP or USR1 signal.)

Depending on your Apache install and Unix variant, there are many possible ways to stop and restart the server. Below are some typical lines used in restarting the server, for different apache/unix installations. You should replace /path/to/ with the path to these applications on your systems.

1. Several Linux and SysV variants:
/etc/rc.d/init.d/httpd restart

2. Using apachectl scripts:
/path/to/apachectl stop
/path/to/apachectl start

3. httpdctl and httpsdctl (Using OpenSSL), similar to apachectl:
/path/to/httpsdctl stop
/path/to/httpsdctl start

4. Using mod_ssl, or another SSL server, you may want to manually
stop and start:
/path/to/apachectl stop
/path/to/apachectl startssl

The locations of the apachectl and http(s)dctl binaries often vary. If your system has locate or whereis or which commands, these can assist you in finding your server control programs.

Different examples of compiling PHP for apache are as follows:

./configure --with-apxs --with-pgsql

This will create a libphp4.so shared library that is loaded into Apache using a LoadModule line in Apache's httpd.conf file. The PostgreSQL support is embedded into this libphp4.so library.

./configure --with-apxs --with-pgsql=shared

This will create a libphp4.so shared library for Apache, but it will also create a pgsql.so shared library that is loaded into PHP either by using the extension directive in php.ini file or by loading it explicitly in a script using the dl() function.

./configure --with-apache=/path/to/apache_source --with-pgsql

This will create a libmodphp4.a library, a mod_php4.c and some accompanying files and copy this into the src/modules/php4 directory in the Apache source tree. Then you compile Apache using --activate-module=src/modules/php4/libphp4.a and the Apache build system will create libphp4.a and link it statically into the httpd binary. The PostgreSQL support is included directly into this httpd binary, so the final result here is a single httpd binary that includes all of Apache and all of PHP.

./configure --with-apache=/path/to/apache_source --with-pgsql=shared

Same as before, except instead of including PostgreSQL support directly into the final httpd you will get a pgsql.so shared library that you can load into PHP from either the php.ini file or directly using dl().

When choosing to build PHP in different ways, you should consider the advantages and drawbacks of each method. Building as a shared object will mean that you can compile apache separately, and don't have to recompile everything as you add to, or change, PHP. Building PHP into apache (static method) means that PHP will load and run faster. For more information, see the Apache webpage on DSO support.

Note: Apache's default http.conf currently ships with a section that looks like this:
User nobody
Group "#-1"
Unless you change that to "Group nogroup" or something like that ("Group daemon" is also very common) PHP will not be able to open files.

Note: Make sure you specify the installed version of apxs when using --with-apxs=/path/to/apxs. You must NOT use the apxs version that is in the apache sources but the one that is actually installed on your system.

Installing PHP on Windows with Apache 1.3.x

There are two ways to set up PHP to work with Apache 1.3.x on Windows. One is to use the CGI binary (php.exe), the other is to use the Apache module DLL. In either case you need to stop the Apache server, and edit your srm.conf or httpd.conf to configure Apache to work with PHP.

It is worth noting here that now the SAPI module has been made more stable under windows, we recommend it's use above the CGI binary, since it is more transparent and secure.

Although there can be a few variations of configuring PHP under Apache, these are simple enough to be used by the newcomer. Please consult the Apache Docs for further configuration directives.

If you unziped the PHP package to c:\php\ as described in the Manual Installation Steps section, you need to insert these lines to your Apache configuration file to set up the CGI binary:

ScriptAlias /php/ "c:/php/"
AddType application/x-httpd-php .php .phtml
Action application/x-httpd-php "/php/php.exe"

Note that the second line in the list above can be found in the actual versions of httpd.conf, but it is commented out. Remember also to substitute the c:/php/ for your actual path to PHP.

Warning

By using the CGI setup, your server is open to several possible attacks. Please read our CGI security section to learn how to defend yourself from attacks.

If you would like to use PHP as a module in Apache, be sure to move php4ts.dll to the windows/system (for Windows 9x/Me) or winnt/system32 (for Windows NT/2000/XP) directory, overwriting any older file. Then you should add the following two lines to you Apache conf file:

LoadModule php4_module c:/php/sapi/php4apache.dll
AddType application/x-httpd-php .php .phtml

After changing the configuration file, remember to restart the server, for example, NET STOP APACHE followed by NET START APACHE, if you run Apache as a Windows Service, or use your regular shortcuts.

Note: You may find after using the windows installer for Apache that you need to define the AddModule directive for mod_php4.c in the configuration file (httpd.conf). This is done by adding AddModule mod_php4.c to the AddModule list, near the beginning of the configuration file. This is especially important if the ClearModuleList directive is defined. Failure to do this may mean PHP will not be registered as an Apache module.

There are 2 ways you can use the source code highlighting feature, however their ability to work depends on your installation. If you have configured Apache to use PHP as an ISAPI module, then by adding the following line to your configuration file you can use this feature: AddType application/x-httpd-php-source .phps

If you chose to configure Apache to use PHP as a CGI binary, you will need to use the show_source() function. To do this simply create a PHP script file and add this code: <?php show_source ("original_php_script.php"); ?>. Substitute original_php_script.php with the name of the file you wish to show the source of.

Note: On Win-Apache all backslashes in a path statement such as "c:\directory\file.ext", must be converted to forward slashes, as "c:/directory/file.ext".

Servers-Caudium

PHP 4 can be built as a Pike module for the Caudium webserver. Note that this is not supported with PHP 3. Follow the simple instructions below to install PHP 4 for Caudium.

Example 3-6. Caudium Installation Instructions

1.  Make sure you have Caudium installed prior to attempting to
    install PHP 4. For PHP 4 to work correctly, you will need Pike
    7.0.268 or newer. For the sake of this example we assume that
    Caudium is installed in /opt/caudium/server/.
2.  Change directory to php-x.y.z (where x.y.z is the version number).
3.  ./configure --with-caudium=/opt/caudium/server
4.  make
5.  make install
6.  Restart Caudium if it's currently running.
7.  Log into the graphical configuration interface and go to the
    virtual server where you want to add PHP 4 support.
8.  Click Add Module and locate and then add the PHP 4 Script Support module.
9.  If the documentation says that the 'PHP 4 interpreter isn't
    available', make sure that you restarted the server. If you did
    check /opt/caudium/logs/debug/default.1 for any errors related to
    <filename>PHP4.so</filename>. Also make sure that 
    <filename>caudium/server/lib/[pike-version]/PHP4.so</filename>
    is present.
10. Configure the PHP Script Support module if needed.

You can of course compile your Caudium module with support for the various extensions available in PHP 4. See the complete list of configure options for an exhaustive rundown.

Note: When compiling PHP 4 with MySQL support you must make sure that the normal MySQL client code is used. Otherwise there might be conflicts if your Pike already has MySQL support. You do this by specifying a MySQL install directory the --with-mysql option.

Servers-fhttpd

To build PHP as an fhttpd module, answer "yes" to "Build as an fhttpd module?" (the --with-fhttpd=DIR option to configure) and specify the fhttpd source base directory. The default directory is /usr/local/src/fhttpd. If you are running fhttpd, building PHP as a module will give better performance, more control and remote execution capability.

Servers-IIS/PWS

This section contains notes and hints specific to IIS (Microsoft Internet Information Server). Installing PHP for PWS/IIS 3, PWS 4 or newer and IIS 4 or newer versions.

Windows and PWS/IIS 3

The recommended method for configuring these servers is to use the REG file included with the distribution (pws-php4cgi.reg). You may want to edit this file and make sure the extensions and PHP install directories match your configuration. Or you can follow the steps below to do it manually.

Warning

These steps involve working directly with the Windows registry. One error here can leave your system in an unstable state. We highly recommend that you back up your registry first. The PHP Development team will not be held responsible if you damage your registry.

Run Regedit.
Navigate to: HKEY_LOCAL_MACHINE /System /CurrentControlSet /Services /W3Svc /Parameters /ScriptMap.
On the edit menu select: New->String Value.
Type in the extension you wish to use for your php scripts. For example .php
Double click on the new string value and enter the path to php.exe in the value data field. ex: c:\php\php.exe.
Repeat these steps for each extension you wish to associate with PHP scripts.

The following steps do not affect the web server installation and only apply if you want your php scripts to be executed when they are run from the command line (ex. run c:\myscripts\test.php) or by double clicking on them in a directory viewer window. You may wish to skip these steps as you might prefer the PHP files to load into a text editor when you double click on them.

Navigate to: HKEY_CLASSES_ROOT
On the edit menu select: New->Key.
Name the key to the extension you setup in the previous section. ex: .php
Highlight the new key and in the right side pane, double click the "default value" and enter phpfile.
Repeat the last step for each extension you set up in the previous section.
Now create another New->Key under HKEY_CLASSES_ROOT and name it phpfile.
Highlight the new key phpfile and in the right side pane, double click the "default value" and enter PHP Script.
Right click on the phpfile key and select New->Key, name it Shell.
Right click on the Shell key and select New->Key, name it open.
Right click on the open key and select New->Key, name it command.
Highlight the new key command and in the right side pane, double click the "default value" and enter the path to php.exe. ex: c:\php\php.exe -q %1. (don't forget the %1).
Exit Regedit.
If using PWS on Windows, reboot to reload the registry.

PWS and IIS 3 users now have a fully operational system. IIS 3 users can use a nifty tool from Steven Genusa to configure their script maps.

Windows and PWS 4 or newer

When installing PHP on Windows with PWS 4 or newer version, you have two options. One to set up the PHP CGI binary, the other is to use the ISAPI module DLL.

If you choose the CGI binary, do the following:

Edit the enclosed pws-php4cgi.reg file (look into the SAPI dir) to reflect the location of your php.exe. Forward slashes should be escaped, for example: [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\w3svc\parameters\Script Map] ".php"="c:\\php\\php.exe"
In the PWS Manager, right click on a given directory you want to add PHP support to, and select Properties. Check the 'Execute' checkbox, and confirm.

If you choose the ISAPI module, do the following:

Edit the enclosed pws-php4isapi.reg file (look into the SAPI dir) to reflect the location of your php4isapi.dll. Forward slashes should be escaped, for example: [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\w3svc\parameters\Script Map] ".php"="c:\\php\\sapi\\php4isapi.dll"
In the PWS Manager, right click on a given directory you want to add PHP support to, and select Properties. Check the 'Execute' checkbox, and confirm.

Windows NT/2000/XP and IIS 4 or newer

To install PHP on an NT/2000/XP Server running IIS 4 or newer, follow these instructions. You have two options to set up PHP, using the CGI binary (php.exe) or with the ISAPI module.

In either case, you need to start the Microsoft Management Console (may appear as 'Internet Services Manager', either in your Windows NT 4.0 Option Pack branch or the Control Panel=>Administrative Tools under Windows 2000/XP). Then right click on your Web server node (this will most probably appear as 'Default Web Server'), and select 'Properties'.

If you want to use the CGI binary, do the following:

Under 'Home Directory', 'Virtual Directory', or 'Directory', click on the 'Configuration' button, and then enter the App Mappings tab.
Click Add, and in the Executable box, type: c:\php\php.exe (assuming that you have unziped PHP in c:\php\).
In the Extension box, type the file name extension you want associated with PHP scripts. Leave 'Method exclusions' blank, and check the Script engine checkbox. You may also like to check the 'check that file exists' box - for a small performance penalty, IIS (or PWS) will check that the script file exists and sort out authentication before firing up php. This means that you will get sensible 404 style error messages instead of cgi errors complaining that php did not output any data.
You must start over from the previous step for each extension you want associated with PHP scripts. .php and .phtml are common, although .php3 may be required for legacy applications.
Set up the appropriate security. (This is done in Internet Service Manager), and if your NT Server uses NTFS file system, add execute rights for I_USR_ to the directory that contains php.exe.

To use the ISAPI module, do the following:

If you don't want to perform HTTP Authentication using PHP, you can (and should) skip this step. Under ISAPI Filters, add a new ISAPI filter. Use PHP as the filter name, and supply a path to the php4isapi.dll.
Under 'Home Directory', click on the 'Configuration' button. Add a new entry to the Application Mappings. Use the path to the php4isapi.dll as the Executable, supply .php as the extension, leave Method exclusions blank, and check the Script engine checkbox.
Stop IIS completely (NET STOP iisadmin)
Start IIS again (NET START w3svc)

Servers-Netscape and iPlanet

This section contains notes and hints specific to Netscape and iPlanet installs of PHP, both for Sun Solaris and Windows versions.

You can find more information about setting up PHP for the Netscape Enterprise Server here: http://benoit.noss.free.fr/php/install-php4.html

Installing PHP with Netscape on Sun Solaris

To build PHP with NES or iPlanet web servers, enter the proper install directory for the --with-nsapi = DIR option. The default directory is usually /opt/netscape/suitespot/. Please also read /php-xxx-version/sapi/nsapi/nsapi-readme.txt.

Example 3-7. Installation Example for Netscape Enterprise on Solaris
Instructions for Sun Solaris 2.6 with Netscape Enterprise Server 3.6 From: bhager@invacare.com 1. Install the following packages from www.sunfreeware.com or another download site: flex-2_5_4a-sol26-sparc-local gcc-2_95_2-sol26-sparc-local gzip-1.2.4-sol26-sparc-local perl-5_005_03-sol26-sparc-local bison-1_25-sol26-sparc-local make-3_76_1-sol26-sparc-local m4-1_4-sol26-sparc-local autoconf-2.13 automake-1.4 mysql-3.23.24-beta (if you want mysql support) tar-1.13 (GNU tar) 2. Make sure your path includes the proper directories PATH=.:/usr/local/bin:/usr/sbin:/usr/bin:/usr/ccs/bin export PATH 3. gunzip php-x.x.x.tar.gz (if you have a .gz dist, otherwise go to 4) 4. tar xvf php-x.x.x.tar 5. cd ../php-x.x.x 6. For the following step, make sure /opt/netscape/suitespot/ is where your netscape server is installed. Otherwise, change to correct path: /configure --with-mysql=/usr/local/mysql --with-nsapi=/opt/netscape/suitespot/ --enable-track-vars --enable-libgcc 7. make 8. make install
After performing the base install and reading the appropriate readme file, you may need to performs some additional configuration steps.

Firstly you may need to add some paths to the LD_LIBRARY_PATH environment for Netscape to find all the shared libs. This can best done in the start script for your Netscape server. Windows users can probably skip this step. The start script is often located in: /path/to/server/https-servername/start

You may also need to edit the configuration files that are located in:/path/to/server/https-servername/config/.

Example 3-8. Configuration Example for Netscape Enterprise

Configuration Instructions for Netscape Enterprise Server
From: bhager@invacare.com

1. Add the following line to mime.types:
    type=magnus-internal/x-httpd-php exts=php

2. Add the following to obj.conf, shlib will vary depending on
    your OS, for unix it will be something like
    /opt/netscape/suitespot/bin/libphp4.so.

    You should place the following lines after mime types init.
    Init fn="load-modules" funcs="php4_init,php4_close,php4_execute,php4_auth_trans" shlib="/php4/nsapiPHP4.dll"
    Init fn=php4_init errorString="Failed to initialize PHP!"

    <object name="default">
    . 
    . 
    . 
    .#NOTE this next line should happen after all 'ObjectType' and before all 'AddLog' lines 
    Service fn="php4_execute" type="magnus-internal/x-httpd-php" 
    . 
    . 
    </Object>


    <Object name="x-httpd-php"> 
    ObjectType fn="force-type" type="magnus-internal/x-httpd-php" 
    Service fn=php4_execute 
    </Object> 


    Authentication configuration 

    PHP authentication cannot be used with any other authentication. ALL AUTHENTICATION IS 
    PASSED TO YOUR PHP SCRIPT. To configure PHP Authentication for the entire server, add 
    the following line: 

    <Object name="default"> 
    AuthTrans fn=php4_auth_trans 
    . 
    . 
    . 
    . 
    </Object> 

    To use PHP Authentication on a single directory, add the following: 

    <Object ppath="d:\path\to\authenticated\dir\*"> 
    AuthTrans fn=php4_auth_trans 
    </Object>

If you are running Netscape Enterprise 4.x, then you should use the following:

Example 3-9. Configuration Example for Netscape Enterprise 4.x

Place these lines after the mime types init, and everything else is similar
to the example configuration above.
From: Graeme Hoose (GraemeHoose@BrightStation.com)

Init fn="load-modules" shlib="/path/to/server4/bin/libphp4.so" funcs="php4_init,php4_close,php4_execute,php4_auth_trans"
Init fn="php4_init" LateInit="yes"

Installing PHP with Netscape on Windows

To Install PHP as CGI (for Netscape Enterprise Server, iPlanet, perhaps Fastrack), do the following:

Copy php4ts.dll to your systemroot (the directory where you installed windows)
Make a file association from the command line. Type the following two lines:
assoc .php=PHPScript ftype PHPScript=c:\php\php.exe %1 %*
In the Netscape Enterprise Administration Server create a dummy shellcgi directory and remove it just after (this step creates 5 important lines in obj.conf and allow the web server to handle shellcgi scripts).
In the Netscape Enterprise Administration Server create a new mime type (Category: type, Content-Type: magnus-internal/shellcgi, File Suffix:php).
Do it for each web server instance you want php to run

More details about setting up PHP as a CGI executable can be found here: http://benoit.noss.free.fr/php/install-php.html

To Install PHP as NSAPI (for Netscape Enterprise Server, iPlanet, perhaps Fastrack, do the following:

Copy php4ts.dll to your systemroot (the directory where you installed windows)
Make a file association from the command line. Type the following two lines:
assoc .php=PHPScript ftype PHPScript=c:\php\php.exe %1 %*
In the Netscape Enterprise Administration Server create a new mime type (Category: type, Content-Type: magnus-internal/x-httpd-php, File Suffix:php).

Stop your web service and edit obj.conf. At the end of the Init section, place these two lines (necessarily after mime type init!):
Init fn="load-modules" funcs="php4_init,php4_close,php4_execute,php4_auth_trans" shlib="c:/php/sapi/php4nsapi.dll" Init fn="php4_init" errorString="Failed to initialise PHP!"

In The < Object name="default" > section, place this line necessarily after all 'ObjectType' and before all 'AddLog' lines:
Service fn="php4_execute" type="magnus-internal/x-httpd-php"

At the end of the file, create a new object called x-httpd-php, by inserting these lines:
<Object name="x-httpd-php"> ObjectType fn="force-type" type="magnus-internal/x-httpd-php" Service fn=php4_execute </Object>

Restart your web service and apply changes
Do it for each web server instance you want PHP to run

More details about setting up PHP as an NSAPI filter can be found here: http://benoit.noss.free.fr/php/install-php4.html

Servers-OmniHTTPd Server

This section contains notes and hints specific to OmniHTTPd.

OmniHTTPd 2.0b1 and up for Windows

You need to complete the following steps to make PHP work with OmniHTTPd. This is a CGI executable setup. SAPI is supported by OmniHTTPd, but some tests have shown that it is not so stable to use PHP as an ISAPI module.

Step 1: Install OmniHTTPd server.
Step 2: Right click on the blue OmniHTTPd icon in the system tray and select Properties
Step 3: Click on Web Server Global Settings
Step 4: On the 'External' tab, enter: virtual = .php | actual = c:\path-to-php-dir\php.exe, and use the Add button.
Step 5: On the Mime tab, enter: virtual = wwwserver/stdcgi | actual = .php, and use the Add button.
Step 6: Click OK

Repeat steps 2 - 6 for each extension you want to associate with PHP.

Note: Some OmniHTTPd packages come with built in PHP support. You can choose at setup time to do a custom setup, and uncheck the PHP component. We recommend you to use the latest PHP binaries. Some OmniHTTPd servers come with PHP 4 beta distributions, so you should choose not to set up the built in support, but install your own. If the server is already on your machine, use the Replace button in Step 4 and 5 to set the new, correct information.

Servers-Oreilly Website Pro

This section contains notes and hints specific to Oreilly Website Pro.

Oreilly Website Pro 2.5 and up for Windows

This list describes how to set up the PHP CGI binary or the ISAPI module to work with Oreilly Website Pro on Windows.

Edit the Server Properties and select the tab "Mapping".
From the List select "Associations" and enter the desired extension (.php) and the path to the CGI exe (ex. c:\php\php.exe) or the ISAPI DLL file (ex. c:\php\sapi\php4isapi.dll).
Select "Content Types" add the same extension (.php) and enter the content type. If you choose the CGI executable file, enter 'wwwserver/shellcgi', if you choose the ISAPI module, enter 'wwwserver/isapi' (both without quotes).

Servers-Sambar

This section contains notes and hints specific to the Sambar server for Windows.

Sambar Windows

This list describes how to set up the ISAPI module to work with the Sambar server on Windows.

Find the file called mappings.ini (in the config directory) in the Sambar isntall directory.
Open mappings.ini and add the following line under [ISAPI]:
*.php = c:\php\php4isapi.dll
(This line assumes that PHP was installed in c:\php.)
Now restart the Sambar server for the changes to take effect.

Servers-Xitami

This section contains notes and hints specific to Xitami.

Xitami for Windows

This list describes how to set up the PHP CGI binary to work with Xitami on Windows.

Make sure the webserver is running, and point your browser to xitamis admin console (usually http://127.0.0.1/admin), and click on Configuration.
Navigate to the Filters, and put the extension which PHP should parse (i.e. .php) into the field File extensions (.xxx).
In Filter command or script put the path and name of your php executable i.e. c:\php\php.exe.
Press the 'Save' icon.
Restart the server to reflect changes.

Servers-Other web servers

PHP can be built to support a large number of web servers. Please see Server-related options for a full list of server-related configure options. The PHP CGI binaries are compatible with almost all webservers supporting the CGI standard.

Problems?

Read the FAQ

Some problems are more common than others. The most common ones are listed in the PHP FAQ, part of this manual.

Bug reports

If you think you have found a bug in PHP, please report it. The PHP developers probably don't know about it, and unless you report it, chances are it won't be fixed. You can report bugs using the bug-tracking system at http://bugs.php.net/. Please do not send bug reports in mailing list or personal letters. The bug system is also suitable to submit feature requests.

Read the How to report a bug document before submitting any bug reports!

Complete list of configure options

Note: These are only used at compile time. If you want to alter PHP's runtime configuration, please see the chapter on Configuration.

The following is a complete list of options supported by PHP 4 configure scripts (as of 4.1.0), used when compiling in Unix-like environments. Some are available in PHP 3, some in PHP 4, and some in both. This is not noted yet.

There are general configuration options for the configure script, consult the appropriate manual pages for GNU autoconf or use the command configure --help for a full, up-to-date list.

Database
Graphics
Miscellaneous
PHP Behaviour
Server
XML

Configure Options in PHP 4

Note: These options are only used in PHP 4 as of PHP 4.1.0. Some are available in older versions of PHP 4, some even in PHP 3, some only in PHP 4.1.0. If you want to compile an older version, some options will probably not be available.

Database options

--with-db: Include old xDBM support (deprecated).
--enable-dba=shared: Build DBA as a shared module.
--with-gdbm[=DIR]: Include GDBM support.
--with-ndbm[=DIR]: Include NDBM support.
--with-db2[=DIR]: Include Berkeley DB2 support.
--with-db3[=DIR]: Include Berkeley DB3 support.
--with-dbm[=DIR]: Include DBM support.
--with-cdb[=DIR]: Include CDB support.
--enable-dbase: Enable the bundled dbase library.
--with-dbplus: Include dbplus support.
--enable-dbx: Enable dbx.
--with-fbsql[=DIR]: Include FrontBase support. DIR is the FrontBase base directory.
--enable-filepro: Enable the bundled read-only filePro support.
--with-fribidi[=DIR]: Include fribidi support (requires FriBidi >=0.1.12). DIR is the fribidi installation directory - default /usr/local/.
--with-informix[=DIR]: Include Informix support. DIR is the Informix base install directory, defaults to nothing.
--with-ingres[=DIR]: Include Ingres II support. DIR is the Ingres base directory (default /II/ingres).
--with-interbase[=DIR]: Include InterBase support. DIR is the InterBase base install directory, defaults to /usr/interbase.
--with-msql[=DIR]: Include mSQL support. DIR is the mSQL base install directory, defaults to /usr/local/Hughes.
--with-mysql[=DIR]: Include MySQL support. DIR is the MySQL base directory. If unspecified, the bundled MySQL library will be used.
--with-oci8[=DIR]: Include Oracle-oci8 support. Default DIR is ORACLE_HOME.
--with-adabas[=DIR]: Include Adabas D support. DIR is the Adabas base install directory, defaults to /usr/local.
--with-sapdb[=DIR]: Include SAP DB support. DIR is SAP DB base install directory, defaults to /usr/local.
--with-solid[=DIR]: Include Solid support. DIR is the Solid base install directory, defaults to /usr/local/solid.
--with-ibm-db2[=DIR]: Include IBM DB2 support. DIR is the DB2 base install directory, defaults to /home/db2inst1/sqllib.
--with-empress[=DIR]: Include Empress support. DIR is the Empress base install directory, defaults to $EMPRESSPATH. From PHP4, this option only supports Empress Version 8.60 and above.
--with-empress-bcs[=DIR]: Include Empress Local Access support. DIR is the Empress base install directory, defaults to $EMPRESSPATH. From PHP4, this option only supports Empress Version 8.60 and above.
--with-birdstep[=DIR]: Include Birdstep support. DIR is the Birdstep base install directory, defaults to /usr/local/birdstep.
--with-custom-odbc[=DIR]: Include a user defined ODBC support. The DIR is ODBC install base directory, which defaults to /usr/local. Make sure to define CUSTOM_ODBC_LIBS and have some odbc.h in your include dirs. E.g., you should define following for Sybase SQL Anywhere 5.5.00 on QNX, prior to run configure script: CPPFLAGS="-DODBC_QNX -DSQLANY_BUG" LDFLAGS=-lunix CUSTOM_ODBC_LIBS="-ldblib -lodbc".
--with-iodbc[=DIR]: Include iODBC support. DIR is the iODBC base install directory, defaults to /usr/local.
--with-esoob[=DIR]: Include Easysoft OOB support. DIR is the OOB base install directory, defaults to /usr/local/easysoft/oob/client.
--with-unixODBC[=DIR]: Include unixODBC support. DIR is the unixODBC base install directory, defaults to /usr/local.
--with-openlink[=DIR]: Include OpenLink ODBC support. DIR is the OpenLink base install directory, defaults to /usr/local. This is the same as iODBC.
--with-dbmaker[=DIR]: Include DBMaker support. DIR is the DBMaker base install directory, defaults to where the latest version of DBMaker is installed (such as /home/dbmaker/3.6).
--with-oracle[=DIR]: Include Oracle-oci7 support. Default DIR is ORACLE_HOME.
--with-ovrimos[=DIR]: Include Ovrimos SQL Server support. DIR is the Ovrimos' libsqlcli install directory.
--with-pgsql[=DIR]: Include PostgreSQL support. DIR is the PostgreSQL base install directory, defaults to /usr/local/pgsql. Set DIR to shared to build as a dl, or shared,DIR to build as a dl and still specify DIR.
--with-sybase[=DIR]: Include Sybase-DB support. DIR is the Sybase home directory, defaults to /home/sybase.
--with-sybase-ct[=DIR]: Include Sybase-CT support. DIR is the Sybase home directory. Defaults to /home/sybase.
--disable-unified-odbc: Disable unified ODBC support. Only applicable if iODBC, Adabas, Solid, Velocis or a custom ODBC interface is enabled. PHP 3 only!

Graphics options

--with-gd[=DIR]: Include GD support (DIR is GD's install dir). Set DIR to shared to build as a dl, or shared,DIR to build as a dl and still specify DIR.
--enable-gd-native-ttf: GD: Enable TrueType string function in gd.
--with-jpeg-dir=DIR: GD: Set the path to libjpeg install prefix.
--with-png-dir=DIR: GD: Set the path to libpng install prefix.
--with-xpm-dir=DIR: GD: Set the path to libXpm install prefix.
--with-freetype-dir=DIR: GD: Set the path to freetype2 install prefix.
--with-ttf[=DIR]: GD: Include FreeType 1.x support.
--with-t1lib[=DIR]: GD: Include T1lib support.
--with-cpdflib[=DIR]: Include cpdflib support (requires cpdflib >= 2). DIR is the cpdfllib install directory, defaults to /usr.
--with-jpeg-dir[=DIR]: jpeg dir for cpdflib 2.x.
--with-tiff-dir[=DIR]: tiff dir for cpdflib 2.x.
--with-pdflib[=DIR]: Include PDFlib support. DIR is the pdflib base install directory, defaults to /usr/local. Set DIR to shared to build as dl, or shared,DIR to build as dl and still specify DIR.
--with-jpeg-dir[=DIR]: PDFLIB: define libjpeg install directory.
--with-png-dir[=DIR]: PDFLIB: define libpng install directory.
--with-tiff-dir[=DIR]: PDFLIB: define libtiff install directory.
--with-swf[=DIR]: Include swf support.
--without-gd: Disable GD support. PHP 3 only!
--with-imagick: Include ImageMagick support. DIR is the install directory, and if left out, PHP will try to find it on its own. [experimental]. PHP 3 only!
--with-ming[=DIR]: Include ming support.

Misc options

--enable-force-cgi-redirect: Enable the security check for internal server redirects. You should use this if you are running the CGI version with Apache.
--enable-discard-path: If this is enabled, the PHP CGI binary can safely be placed outside of the web tree and people will not be able to circumvent .htaccess security.
--with-fastcgi=SRCDIR: Build PHP as FastCGI application.
--enable-debug: Compile with debugging symbols.
--with-layout=TYPE: Sets how installed files will be laid out. Type is one of PHP (default) or GNU.
--with-pear=DIR: Install PEAR in DIR (default PREFIX/lib/php).
--without-pear: Do not install PEAR.
--with-openssl[=DIR]: Include OpenSSL support (requires OpenSSL >= 0.9.5).
--enable-sigchild: Enable PHP's own SIGCHLD handler.
--disable-rpath: Disable passing additional runtime library search paths.
--enable-libgcc: Enable explicitly linking against libgcc.
--enable-dmalloc: Enable dmalloc.
--enable-php-streams: Include experimental php streams. Do not use unless you are testing the code!
--with-zlib-dir=<DIR>: Define the location of zlib install directory.
--with-zlib[=DIR]: Include zlib support (requires zlib >= 1.0.9). DIR is the zlib install directory.
--with-aspell[=DIR]: Include ASPELL support.
--enable-bcmath: Enable bc style precision math functions.
--with-bz2[=DIR]: Include BZip2 support.
--enable-calendar: Enable support for calendar conversion.
--with-ccvs[=DIR]: Include CCVS support.
--with-crack[=DIR]: Include crack support.
--enable-ctype: Enable ctype support.
--with-curl[=DIR]: Include CURL support.
--with-cybercash[=DIR]: Include CyberCash support. DIR is the CyberCash MCK install directory.
--with-cybermut[=DIR]: Include CyberMut (French Credit Mutuel telepaiement).
--with-cyrus: Include cyrus IMAP support.
--enable-exif: Enable exif support.
--with-fdftk[=DIR]: Include fdftk support.
--enable-ftp: Enable FTP support.
--with-gettext[=DIR]: Include GNU gettext support. DIR is the gettext install directory, defaults to /usr/local.
--with-gmp: Include gmp support.
--with-hyperwave: Include Hyperwave support.
--with-icap[=DIR]: Include ICAP support.
--with-iconv[=DIR]: Include iconv support.
--with-imap[=DIR]: Include IMAP support. DIR is the c-client install prefix.
--with-kerberos[=DIR]: IMAP: Include Kerberos support. DIR is the Kerberos install dir.
--with-imap-ssl[=DIR]: IMAP: Include SSL support. DIR is the OpenSSL install dir.
--with-ircg-config: Path to the ircg-config script.
--with-ircg: Include ircg support.
--with-java[=DIR]: Include Java support. DIR is the base install directory for the JDK. This extension can only be built as a shared dl.
--with-ldap[=DIR]: Include LDAP support. DIR is the LDAP base install directory.
--enable-mailparse: Enable mailparse support.
--enable-mbstring: Enable multibyte string support.
--enable-mbstr-enc-trans: Enable japanese encoding translation.
--with-mcal[=DIR]: Include MCAL support.
--with-mcrypt[=DIR]: Include mcrypt support. DIR is the mcrypt install directory.
--with-mhash[=DIR]: Include mhash support. DIR is the mhash install directory.
--with-mnogosearch[=DIR]: Include mnoGoSearch support. DIR is the mnoGoSearch base install directory, defaults to /usr/local/mnogosearch.
--with-muscat[=DIR]: Include muscat support.
--with-ncurses: Include ncurses support.
--enable-pcntl: Enable experimental pcntl support (CGI ONLY!)
--without-pcre-regex: Do not include Perl Compatible Regular Expressions support. Use --with-pcre-regex=DIR to specify DIR where PCRE's include and library files are located, if not using bundled library.
--with-pfpro[=DIR]: Include Verisign Payflow Pro support.
--disable-posix: Disable POSIX-like functions.
--with-pspell[=DIR]: Include PSPELL support.
--with-qtdom: Include QtDOM support (requires Qt >= 2.2.0).
--with-libedit[=DIR]: Include libedit readline replacement.
--with-readline[=DIR]: Include readline support. DIR is the readline install directory.
--with-recode[=DIR]: Include recode support. DIR is the recode install directory.
--with-satellite[=DIR]: Enable CORBA support via Satellite (EXPERIMENTAL) DIR is the base directory for ORBit.
--with-mm[=DIR]: Include mm support for session storage.
--enable-trans-sid: Enable transparent session id propagation.
--disable-session: Disable session support.
--enable-shmop: Enable shmop support.
--with-snmp[=DIR]: Include SNMP support. DIR is the SNMP base install directory, defaults to searching through a number of common locations for the snmp install. Set DIR to shared to build as a dl, or shared,DIR to build as a dl and still specify DIR.
--enable-ucd-snmp-hack: Enable UCD SNMP hack.
--enable-sockets: Enable sockets support.
--with-regex=TYPE: regex library type: system, apache, php.
--with-system-regex: Use system regex library (deprecated).
--enable-sysvsem: Enable System V semaphore support.
--enable-sysvshm: Enable the System V shared memory support.
--with-vpopmail[=DIR]: Include vpopmail support.
--with-tsrm-pthreads: Use POSIX threads (default).
--enable-shared[=PKGS]: Build shared libraries [default=yes].
--enable-static[=PKGS]: Build static libraries [default=yes].
--enable-fast-install[=PKGS]: Optimize for fast installation [default=yes].
--with-gnu-ld: Assume the C compiler uses GNU ld [default=no].
--disable-libtool-lock: Avoid locking (might break parallel builds).
--with-pic: Try to use only PIC/non-PIC objects [default=use both].
--with-yaz[=DIR]: Include YAZ support (ANSI/NISO Z39.50). DIR is the YAZ bin install directory.
--enable-memory-limit: Compile with memory limit support.
--disable-url-fopen-wrapper: Disable the URL-aware fopen wrapper that allows accessing files via HTTP or FTP.
--enable-versioning: Export only required symbols. See INSTALL for more information.
--disable-bcmath: Compile without bc style precision math functions. PHP 3 only!
--with-imsp[=DIR]: Include IMSp support (DIR is IMSP's include dir and libimsp.a dir). PHP 3 only!
--with-ftp: Include FTP support. PHP 3 only!
--with-mck[=DIR]: Include Cybercash MCK support. DIR is the cybercash mck build directory, defaults to /usr/src/mck-3.2.0.3-linux for help look in extra/cyberlib. PHP 3 only!
--disable-overload: Disable user-space object overloading support. PHP 3 only!
--enable-yp: Include YP support. PHP 3 only!
--with-zip: Include ZIP support (requires zziplib >= 0.10.6). PHP 3 only!
--with-mod-dav=DIR: Include DAV support through Apache's mod_dav, DIR is mod_dav's installation directory (Apache module version only!) PHP 3 only!
--enable-debugger: Compile with remote debugging functions. PHP 3 only!
--enable-versioning: Take advantage of versioning and scoping provided by Solaris 2.x and Linux. PHP 3 only!

PHP options

--enable-maintainer-mode: Enable make rules and dependencies not useful (and sometimes confusing) to the casual installer.
--with-config-file-path=PATH: Sets the path in which to look for php.ini, defaults to PREFIX/lib.
--enable-safe-mode: Enable safe mode by default.
--with-exec-dir[=DIR]: Only allow executables in DIR when in safe mode defaults to /usr/local/php/bin.
--enable-magic-quotes: Enable magic quotes by default.
--disable-short-tags: Disable the short-form <? start tag by default.

Server options

--with-aolserver=DIR: Specify path to the installed AOLserver.
--with-apxs[=FILE]: Build shared Apache module. FILE is the optional pathname to the Apache apxs tool; defaults to apxs. Make sure you specify the version of apxs that is actually installed on your system and NOT the one that is in the apache source tarball.
--with-apache[=DIR]: Build Apache module. DIR is the top-level Apache build directory, defaults to /usr/local/apache.
--with-mod_charset: Enable transfer tables for mod_charset (Rus Apache).
--with-apxs2[=FILE]: Build shared Apache 2.0 module. FILE is the optional pathname to the Apache apxs tool; defaults to apxs.
--with-fhttpd[=DIR]: Build fhttpd module. DIR is the fhttpd sources directory, defaults to /usr/local/src/fhttpd.
--with-isapi=DIR: Build PHP as an ISAPI module for use with Zeus.
--with-nsapi=DIR: Specify path to the installed Netscape Server.
--with-phttpd=DIR: No information yet.
--with-pi3web=DIR: Build PHP as a module for use with Pi3Web.
--with-roxen=DIR: Build PHP as a Pike module. DIR is the base Roxen directory, normally /usr/local/roxen/server.
--enable-roxen-zts: Build the Roxen module using Zend Thread Safety.
--with-servlet[=DIR]: Include servlet support. DIR is the base install directory for the JSDK. This SAPI prereqs the java extension must be built as a shared dl.
--with-thttpd=SRCDIR: Build PHP as thttpd module.
--with-tux=MODULEDIR: Build PHP as a TUX module (Linux only).

XML options

--with-dom[=DIR]: Include DOM support (requires libxml >= 2.4.2). DIR is the libxml install directory, defaults to /usr.
--disable-xml: Disable XML support using bundled expat lib.
--with-expat-dir=DIR: XML: external libexpat install dir.
--with-xmlrpc[=DIR]: Include XMLRPC-EPI support.
--enable-wddx: Enable WDDX support.

Chapter 4. Configuration

The configuration file

The configuration file (called php3.ini in PHP 3.0, and simply php.ini as of PHP 4.0) is read when PHP starts up. For the server module versions of PHP, this happens only once when the web server is started. For the CGI and CLI version, it happens on every invocation.

The default location of php.ini is a compile time option (see the FAQ entry), but can be changed for the CGI and CLI version with the -c command line switch, see the chapter about using PHP from the command line. You can also use the environment variable PHPRC for an additional path to search for a php.ini file.

Not every PHP directive is documented below. For a list of all directives, please read your well commented php.ini file. You may want to view the latest php.ini here from CVS.

Note: The default value for the PHP directive register_globals changed from on to off in PHP 4.2.0.

Example 4-1. php.ini example
; any text on a line after an unquoted semicolon (;) is ignored [php] ; section markers (text within square brackets) are also ignored ; Boolean values can be set to either: ; true, on, yes ; or false, off, no, none register_globals = off magic_quotes_gpc = yes ; you can enclose strings in double-quotes include_path = ".:/usr/local/lib/php" ; backslashes are treated the same as any other character include_path = ".;c:\php\lib"

How to change configuration settings

Running `PHP` as Apache module

When using PHP as an Apache module, you can also change the configuration settings using directives in Apache configuration files (e.g. httpd.conf) and .htaccess files (You will need "AllowOverride Options" or "AllowOverride All" privileges)

With PHP 3.0, there are Apache directives that correspond to each configuration setting in the php3.ini name, except the name is prefixed by "php3_".

With PHP 4.0, there are several Apache directives that allow you to change the PHP configuration from within the Apache configuration file itself.

php_value name value: This sets the value of the specified variable.
php_flag name on|off: This is used to set a Boolean configuration option.
php_admin_value name value: This sets the value of the specified variable. "Admin" configuration settings can only be set from within the main Apache configuration files, and not from .htaccess files.
php_admin_flag name on|off: This is used to set a Boolean configuration option.

Example 4-2. Apache configuration example
<IfModule mod_php4.c> php_value include_path ".:/usr/local/lib/php" php_admin_flag safe_mode on </IfModule> <IfModule mod_php3.c> php3_include_path ".:/usr/local/lib/php" php3_safe_mode on </IfModule>

Note: PHP constants do not exist outside of PHP. For example, in httpd.conf do not use PHP constants such as E_ALL or E_NOTICE to set the error_reporting directive as they will have no meaning and will evaluate to 0. Use the associated bitmask values instead. These constants can be used in php.ini

Other interfaces to `PHP`

Regardless of the interface to PHP you can change certain values at runtime of your scripts through ini_set(). The following table provides an overview at which level a directive can be set/changed.

Table 4-1. Definition of PHP_INI_* constants

Constant	Value	Meaning
PHP_INI_USER	1	Entry can be set in user scripts
PHP_INI_PERDIR	2	Entry can be set in `.htaccess` and VHost directives in httpd.conf.
PHP_INI_SYSTEM	4	Entry can be set in `php.ini` or `httpd.conf` (but not in VHost blocks in httpd.conf).
PHP_INI_ALL	7	Entry can be set anywhere

You can view the settings of the configuration values in the output of phpinfo(). You can also access the values of individual configuration settings using ini_get() or get_cfg_var().

Configuration directives

Httpd Options

Table 4-2. Httpd Options

Name	Default	Changeable
async_send	"0"	PHP_INI_ALL

Language Options

Table 4-3. Language and Misc Configuration Options

Name	Default	Changeable
short_open_tag	On	PHP_INI_SYSTEM\|PHP_INI_PERDIR
asp_tags	Off	PHP_INI_SYSTEM\|PHP_INI_PERDIR
precision	"14"	PHP_INI_ALL
y2k_compliance	Off	PHP_INI_ALL
allow_call_time_pass_reference	On	PHP_INI_SYSTEM\|PHP_INI_PERDIR
expose_php	On	PHP_INI_SYSTEM

Here is a short explanation of the configuration directives.

short_open_tag boolean

Tells whether the short form (<? ?>) of PHP's open tag should be allowed. If you want to use PHP in combination with XML, you can disable this option in order to use <?xml ?> inline. Otherwise, you can print it with PHP, for example: <?php echo '<?xml version="1.0"'; ?>. Also if disabled, you must use the long form of the PHP open tag (<?php ?>).

Note: This directive also affects the shorthand <?=, which is identical to <? echo. Use of this shortcut requires short_open_tag to be on.

asp_tags boolean

Enables the use of ASP-like <% %> tags in addition to the usual <?php ?> tags. This includes the variable-value printing shorthand of <%= $value %>. For more information, see Escaping from HTML.

Note: Support for ASP-style tags was added in 3.0.4.

precision integer

The number of significant digits displayed in floating point numbers.

y2k_compliance boolean

Enforce year 2000 compliance (will cause problems with non-compliant browsers)

allow_call_time_pass_reference boolean

Whether to enable the ability to force arguments to be passed by reference at function call time. This method is deprecated and is likely to be unsupported in future versions of PHP/Zend. The encouraged method of specifying which arguments should be passed by reference is in the function declaration. You're encouraged to try and turn this option Off and make sure your scripts work properly with it in order to ensure they will work with future versions of the language (you will receive a warning each time you use this feature, and the argument will be passed by value instead of by reference).

Resource Limits

Table 4-4. Resource Limits

Name	Default	Changeable
memory_limit	"8M"	PHP_INI_ALL

Here is a short explanation of the configuration directives.

memory_limit integer: This sets the maximum amount of memory in bytes that a script is allowed to allocate. This helps prevent poorly written scripts for eating up all available memory on a server.

Data Handling

Table 4-5. Data Handling Configuration Options

Name	Default	Changeable
track-vars	"On"	PHP_INI_??
arg_separator.output	"&"	PHP_INI_ALL
arg_separator.input	"&"	PHP_INI_SYSTEM\|PHP_INI_PERDIR
variables_order	"EGPCS"	PHP_INI_ALL
register_globals	"Off"	PHP_INI_PERDIR\|PHP_INI_SYSTEM
register_argc_argv	"On"	PHP_INI_PERDIR\|PHP_INI_SYSTEM
post_max_size	"8M"	PHP_INI_SYSTEM\|PHP_INI_PERDIR
gpc_order	"GPC"	PHP_INI_ALL
auto_prepend_file	""	PHP_INI_SYSTEM\|PHP_INI_PERDIR
auto_append_file	""	PHP_INI_SYSTEM\|PHP_INI_PERDIR
default_mimetype	"text/html"	PHP_INI_ALL
default_charset	"iso-8859-1"	PHP_INI_ALL
always_populate_raw_post_data	"0"	PHP_INI_SYSTEM\|PHP_INI_PERDIR
allow_webdav_methods	"0"	PHP_INI_SYSTEM\|PHP_INI_PERDIR

Here is a short explanation of the configuration directives.

track_vars boolean

If enabled, then Environment, GET, POST, Cookie, and Server variables can be found in the global associative arrays $_ENV, $_GET, $_POST, $_COOKIE, and $_SERVER.

Note that as of PHP 4.0.3, track_vars is always turned on.

arg_separator.output string

The separator used in PHP generated URLs to separate arguments.

arg_separator.input string

List of separator(s) used by PHP to parse input URLs into variables.

Note: Every character in this directive is considered as separator!

variables_order string

Set the order of the EGPCS (Environment, GET, POST, Cookie, Server) variable parsing. The default setting of this directive is "EGPCS". Setting this to "GP", for example, will cause PHP to completely ignore environment variables, cookies and server variables, and to overwrite any GET method variables with POST-method variables of the same name.

Paths and Directories

Table 4-6. Paths and Directories Configuration Options

Name	Default	Changeable
include_path	PHP_INCLUDE_PATH	PHP_INI_ALL
doc_root	PHP_INCLUDE_PATH	PHP_INI_SYSTEM
user_dir	NULL	PHP_INI_SYSTEM
extension_dir	PHP_EXTENSION_DIR	PHP_INI_SYSTEM
cgi.force_redirect	"1"	PHP_INI_SYSTEM
cgi.redirect_status_env	""	PHP_INI_SYSTEM
fastcgi.impersonate	"0"	PHP_INI_SYSTEM

Here is a short explanation of the configuration directives.

include_path string

Specifies a list of directories where the require(), include() and fopen_with_path() functions look for files. The format is like the system's PATH environment variable: a list of directories separated with a colon in UNIX or semicolon in Windows.
Example 4-3. UNIX include_path
include_path=.:/home/httpd/php-lib

Example 4-4. Windows include_path
include_path=".;c:\www\phplib"
The default value for this directive is . (only the current directory).

doc_root string

PHP's "root directory" on the server. Only used if non-empty. If PHP is configured with safe mode, no files outside this directory are served. If PHP was not compiled with FORCE_REDIRECT, you SHOULD set doc_root if you are running php as a CGI under any web server (other than IIS) The alternative is to use the cgi.force_redirect configuration below.

user_dir string

The base name of the directory used on a user's home directory for PHP files, for example public_html.

extension_dir string

In what directory PHP should look for dynamically loadable extensions. See also: enable_dl, and dl().

extension string

Which dynamically loadable extensions to load when PHP starts up.

cgi.force_redirect boolean

cgi.force_redirect is necessary to provide security running PHP as a CGI under most web servers. Left undefined, PHP turns this on by default. You can turn it off AT YOUR OWN RISK.

Note: Windows Users: You CAN safely turn this off for IIS, in fact, you MUST. To get OmniHTTPD or Xitami to work you MUST turn it off.

cgi.cgi.redirect_status_env string

If cgi.force_redirect is turned on, and you are not running under Apache or Netscape (iPlanet) web servers, you MAY need to set an environment variable name that PHP will look for to know it is OK to continue execution.

Note: Setting this variable MAY cause security issues, KNOW WHAT YOU ARE DOING FIRST.

fastcgi.impersonate string

FastCGI under IIS (on WINNT based OS) supports the ability to impersonate security tokens of the calling client. This allows IIS to define the security context that the request runs under. mod_fastcgi under Apache does not currently support this feature (03/17/2002) Set to 1 if running under IIS. Default is zero.

File Uploads

Table 4-7. File Uploads Configuration Options

Name	Default	Changeable
file_uploads	"1"	PHP_INI_SYSTEM
upload_tmp_dir	NULL	PHP_INI_SYSTEM
upload_max_filesize	"2M"	PHP_INI_SYSTEM\|PHP_INI_PERDIR

Here is a short explanation of the configuration directives.

file_uploads boolean: Whether or not to allow HTTP file uploads. See also the upload_max_filesize, upload_tmp_dir, and post_max_size directives.
upload_tmp_dir string: The temporary directory used for storing files when doing file upload. Must be writable by whatever user PHP is running as. If not specified PHP will use the system's default.
upload_max_filesize integer: The maximum size of an uploaded file.

General SQL

Table 4-8. General SQL Configuration Options

Name	Default	Changeable
sql.safe_mode	"0"	PHP_INI_SYSTEM

Here is a short explanation of the configuration directives.

sql.safe_mode boolean

Debugger Configuration Directives

debugger.host string: DNS name or IP address of host used by the debugger.
debugger.port string: Port number used by the debugger.
debugger.enabled boolean: Whether the debugger is enabled.

Chapter 5. Security

PHP is a powerful language and the interpreter, whether included in a web server as a module or executed as a separate CGI binary, is able to access files, execute commands and open network connections on the server. These properties make anything run on a web server insecure by default. PHP is designed specifically to be a more secure language for writing CGI programs than Perl or C, and with correct selection of compile-time and runtime configuration options, and proper coding practices, it can give you exactly the combination of freedom and security you need.

As there are many different ways of utilizing PHP, there are many configuration options controlling its behaviour. A large selection of options guarantees you can use PHP for a lot of purposes, but it also means there are combinations of these options and server configurations that result in an insecure setup.

The configuration flexibility of PHP is equally rivalled by the code flexibility. PHP can be used to build complete server applications, with all the power of a shell user, or it can be used for simple server-side includes with little risk in a tightly controlled environment. How you build that environment, and how secure it is, is largely up to the PHP developer.

This chapter starts with some general security advice, explains the different configuration option combinations and the situations they can be safely used, and describes different considerations in coding for different levels of security.

General considerations

A completely secure system is a virtual impossibility, so an approach often used in the security profession is one of balancing risk and usability. If every variable submitted by a user required two forms of biometric validation (such as a retinal scan and a fingerprint), you would have an extremely high level of accountability. It would also take half an hour to fill out a fairly complex form, which would tend to encourage users to find ways of bypassing the security.

The best security is often inobtrusive enough to suit the requirements without the user being prevented from accomplishing their work, or over-burdening the code author with excessive complexity. Indeed, some security attacks are merely exploits of this kind of overly built security, which tends to erode over time.

A phrase worth remembering: A system is only as good as the weakest link in a chain. If all transactions are heavily logged based on time, location, transaction type, etc. but the user is only verified based on a single cookie, the validity of tying the users to the transaction log is severely weakened.

When testing, keep in mind that you will not be able to test all possibilities for even the simplest of pages. The input you may expect will be completely unrelated to the input given by a disgruntled employee, a cracker with months of time on their hands, or a housecat walking across the keyboard. This is why it's best to look at the code from a logical perspective, to discern where unexpected data can be introduced, and then follow how it is modified, reduced, or amplified.

The Internet is filled with people trying to make a name for themselves by breaking your code, crashing your site, posting inappropriate content, and otherwise making your day interesting. It doesn't matter if you have a small or large site, you are a target by simply being online, by having a server that can be connected to. Many cracking programs do not discern by size, they simply trawl massive IP blocks looking for victims. Try not to become one.

Installed as CGI binary

Possible attacks

Using PHP as a CGI binary is an option for setups that for some reason do not wish to integrate PHP as a module into server software (like Apache), or will use PHP with different kinds of CGI wrappers to create safe chroot and setuid environments for scripts. This setup usually involves installing executable PHP binary to the web server cgi-bin directory. CERT advisory CA-96.11 recommends against placing any interpreters into cgi-bin. Even if the PHP binary can be used as a standalone interpreter, PHP is designed to prevent the attacks this setup makes possible:

Accessing system files: http://my.host/cgi-bin/php?/etc/passwd
The query information in a url after the question mark (?) is passed as command line arguments to the interpreter by the CGI interface. Usually interpreters open and execute the file specified as the first argument on the command line.
When invoked as a CGI binary, PHP refuses to interpret the command line arguments.
Accessing any web document on server: http://my.host/cgi-bin/php/secret/doc.html
The path information part of the url after the PHP binary name, /secret/doc.html is conventionally used to specify the name of the file to be opened and interpreted by the CGI program. Usually some web server configuration directives (Apache: Action) are used to redirect requests to documents like http://my.host/secret/script.php to the PHP interpreter. With this setup, the web server first checks the access permissions to the directory /secret, and after that creates the redirected request http://my.host/cgi-bin/php/secret/script.php. Unfortunately, if the request is originally given in this form, no access checks are made by web server for file /secret/script.php, but only for the /cgi-bin/php file. This way any user able to access /cgi-bin/php is able to access any protected document on the web server.
In PHP, compile-time configuration option --enable-force-cgi-redirect and runtime configuration directives doc_root and user_dir can be used to prevent this attack, if the server document tree has any directories with access restrictions. See below for full the explanation of the different combinations.

Case 1: only public files served

If your server does not have any content that is not restricted by password or ip based access control, there is no need for these configuration options. If your web server does not allow you to do redirects, or the server does not have a way to communicate to the PHP binary that the request is a safely redirected request, you can specify the option --enable-force-cgi-redirect to the configure script. You still have to make sure your PHP scripts do not rely on one or another way of calling the script, neither by directly http://my.host/cgi-bin/php/dir/script.php nor by redirection http://my.host/dir/script.php.

Redirection can be configured in Apache by using AddHandler and Action directives (see below).

Case 2: using --enable-force-cgi-redirect

This compile-time option prevents anyone from calling PHP directly with a url like http://my.host/cgi-bin/php/secretdir/script.php. Instead, PHP will only parse in this mode if it has gone through a web server redirect rule.

Usually the redirection in the Apache configuration is done with the following directives:

Action php-script /cgi-bin/php
AddHandler php-script .php

This option has only been tested with the Apache web server, and relies on Apache to set the non-standard CGI environment variable REDIRECT_STATUS on redirected requests. If your web server does not support any way of telling if the request is direct or redirected, you cannot use this option and you must use one of the other ways of running the CGI version documented here.

Case 3: setting doc_root or user_dir

To include active content, like scripts and executables, in the web server document directories is sometimes consider an insecure practice. If, because of some configuration mistake, the scripts are not executed but displayed as regular HTML documents, this may result in leakage of intellectual property or security information like passwords. Therefore many sysadmins will prefer setting up another directory structure for scripts that are accessible only through the PHP CGI, and therefore always interpreted and not displayed as such.

Also if the method for making sure the requests are not redirected, as described in the previous section, is not available, it is necessary to set up a script doc_root that is different from web document root.

You can set the PHP script document root by the configuration directive doc_root in the configuration file, or you can set the environment variable PHP_DOCUMENT_ROOT. If it is set, the CGI version of PHP will always construct the file name to open with this doc_root and the path information in the request, so you can be sure no script is executed outside this directory (except for user_dir below).

Another option usable here is user_dir. When user_dir is unset, only thing controlling the opened file name is doc_root. Opening an url like http://my.host/~user/doc.php does not result in opening a file under users home directory, but a file called ~user/doc.php under doc_root (yes, a directory name starting with a tilde [~]).

If user_dir is set to for example public_php, a request like http://my.host/~user/doc.php will open a file called doc.php under the directory named public_php under the home directory of the user. If the home of the user is /home/user, the file executed is /home/user/public_php/doc.php.

user_dir expansion happens regardless of the doc_root setting, so you can control the document root and user directory access separately.

Case 4: PHP parser outside of web tree

A very secure option is to put the PHP parser binary somewhere outside of the web tree of files. In /usr/local/bin, for example. The only real downside to this option is that you will now have to put a line similar to:

#!/usr/local/bin/php

as the first line of any file containing PHP tags. You will also need to make the file executable. That is, treat it exactly as you would treat any other CGI script written in Perl or sh or any other common scripting language which uses the #! shell-escape mechanism for launching itself.

To get PHP to handle PATH_INFO and PATH_TRANSLATED information correctly with this setup, the php parser should be compiled with the --enable-discard-path configure option.

Installed as an Apache module

When PHP is used as an Apache module it inherits Apache's user permissions (typically those of the "nobody" user). This has several impacts on security and authorization. For example, if you are using PHP to access a database, unless that database has built-in access control, you will have to make the database accessable to the "nobody" user. This means a malicious script could access and modify the database, even without a username and password. It's entirely possible that a web spider could stumble across a database administrator's web page, and drop all of your databases. You can protect against this with Apache authorization, or you can design your own access model using LDAP, .htaccess files, etc. and include that code as part of your PHP scripts.

Often, once security is established to the point where the PHP user (in this case, the apache user) has very little risk attached to it, it is discovered that PHP is now prevented from writing any files to user directories. Or perhaps it has been prevented from accessing or changing databases. It has equally been secured from writing good and bad files, or entering good and bad database transactions.

A frequent security mistake made at this point is to allow apache root permissions, or to escalate apache's abilitites in some other way.

Escalating the Apache user's permissions to root is extremely dangerous and may compromise the entire system, so sudo'ing, chroot'ing, or otherwise running as root should not be considered by those who are not security professionals.

There are some simpler solutions. By using open_basedir you can control and restrict what directories are allowed to be used for PHP. You can also set up apache-only areas, to restrict all web based activity to non-user, or non-system, files.

Filesystem Security

PHP is subject to the security built into most server systems with respect to permissions on a file and directory basis. This allows you to control which files in the filesystem may be read. Care should be taken with any files which are world readable to ensure that they are safe for reading by all users who have access to that filesystem.

Since PHP was designed to allow user level access to the filesystem, it's entirely possible to write a PHP script that will allow you to read system files such as /etc/passwd, modify your ethernet connections, send massive printer jobs out, etc. This has some obvious implications, in that you need to ensure that the files that you read from and write to are the appropriate ones.

Consider the following script, where a user indicates that they'd like to delete a file in their home directory. This assumes a situation where a PHP web interface is regularly used for file management, so the Apache user is allowed to delete files in the user home directories.

Example 5-1. Poor variable checking leads to....
<?php // remove a file from the user's home directory $username = $_POST['user_submitted_name']; $homedir = "/home/$username"; $file_to_delete = "$userfile"; unlink ($homedir/$userfile); echo "$file_to_delete has been deleted!"; ?>
Since the username is postable from a user form, they can submit a username and file belonging to someone else, and delete files. In this case, you'd want to use some other form of authentication. Consider what could happen if the variables submitted were "../etc/" and "passwd". The code would then effectively read:
Example 5-2. ... A filesystem attack
<?php // removes a file from anywhere on the hard drive that // the PHP user has access to. If PHP has root access: $username = "../etc/"; $homedir = "/home/../etc/"; $file_to_delete = "passwd"; unlink ("/home/../etc/passwd"); echo "/home/../etc/passwd has been deleted!"; ?>
There are two important measures you should take to prevent these issues.

Only allow limited permissions to the PHP web user binary.
Check all variables which are submitted.

Here is an improved script:

Example 5-3. More secure file name checking

<?php
// removes a file from the hard drive that
// the PHP user has access to.
$username = $_SERVER['REMOTE_USER']; // using an authentication mechanisim

$homedir = "/home/$username";

$file_to_delete = basename("$userfile"); // strip paths
unlink ($homedir/$file_to_delete);

$fp = fopen("/home/logging/filedelete.log","+a"); //log the deletion
$logstring = "$username $homedir $file_to_delete";
fputs ($fp, $logstring);
fclose($fp);

echo "$file_to_delete has been deleted!";
?>

However, even this is not without it's flaws. If your authentication system allowed users to create their own user logins, and a user chose the login "../etc/", the system is once again exposed. For this reason, you may prefer to write a more customized check:

Example 5-4. More secure file name checking

<?php
$username = $_SERVER['REMOTE_USER']; // using an authentication mechanisim
$homedir = "/home/$username";

if (!ereg('^[^./][^/]*$', $userfile))
     die('bad filename'); //die, do not process

if (!ereg('^[^./][^/]*$', $username))
     die('bad username'); //die, do not process
//etc...
?>

Depending on your operating system, there are a wide variety of files which you should be concerned about, including device entries (/dev/ or COM1), configuration files (/etc/ files and the .ini files), well known file storage areas (/home/, My Documents), etc. For this reason, it's usually easier to create a policy where you forbid everything except for what you explicitly allow.

Database Security

Nowadays, databases are cardinal components of any web based application by enabling websites to provide varying dynamic content. Since very sensitive or secret informations can be stored in such database, you should strongly consider to protect them somehow.

To retrieve or to store any information you need to connect to the database, send a legitimate query, fetch the result, and close the connecion. Nowadays, the commonly used query language in this interaction is the Structured Query Language (SQL). See how an attacker can tamper with an SQL query.

As you can realize, PHP cannot protect your database by itself. The following sections aim to be an introduction into the very basics of how to access and manipulate databases within PHP scripts.

Keep in mind this simple rule: defence in depth. In the more place you take the more action to increase the protection of your database, the less probability of that an attacker succeeds, and exposes or abuse any stored secret information. Good design of the database schema and the application deals with your greatest fears.

Designing Databases

The first step is always to create the database, unless you want to use an existing third party's one. When a database is created, it is assigned to an owner, who executed the creation statement. Usually, only the owner (or a superuser) can do anything with the objects in that database, and in order to allow other users to use it, privileges must be granted.

Applications should never connect to the database as its owner or a superuser, because these users can execute any query at will, for example, modifying the schema (e.g. dropping tables) or deleting its entire content.

You may create different database users for every aspect of your application with very limited rights to database objects. The most required privileges should be granted only, and avoid that the same user can interact with the database in different use cases. This means that if intruders gain access to your database using one of these credentials, they can only effect as many changes as your application can.

You are encouraged not to implement all the business logic in the web application (i.e. your script), instead to do it in the database schema using views, triggers or rules. If the system evolves, new ports will be intended to open to the database, and you have to reimplement the logic in each separate database client. Over and above, triggers can be used to transparently and automatically handle fields, which often provides insight when debugging problems with your application or tracing back transactions.

Connecting to Database

You may want to estabilish the connections over SSL to encrypt client/server communications for increased security, or you can use ssh to encrypt the network connection between clients and the database server. If either of them is done, then monitoring your traffic and gaining informations in this way will be a hard work.

Encrypted Storage Model

SSL/SSH protects data travelling from the client to the server, SSL/SSH does not protect the persistent data stored in a database. SSL is an on-the-wire protocol.

Once an attacker gains access to your database directly (bypassing the webserver), the stored sensitive data may be exposed or misused, unless the information is protected by the database itself. Encrypting the data is a good way to mitigate this threat, but very few databases offer this type of data encryption.

The easiest way to work around this problem is to first create your own encryption package, and then use it from within your PHP scripts. PHP can assist you in this case with its several extensions, such as Mcrypt and Mhash, covering a wide variety of encryption algorithms. The script encrypts the data be stored first, and decrypts it when retrieving. See the references for further examples how encryption works.

In case of truly hidden data, if its raw representation is not needed (i.e. not be displayed), hashing may be also taken into consideration. The well-known example for the hashing is storing the MD5 hash of a password in a database, instead of the password itself. See also crypt() and md5().

Example 5-5. Using hashed password field

// storing password hash
$query  = sprintf("INSERT INTO users(name,pwd) VALUES('%s','%s');",
            addslashes($username), md5($password));
$result = pg_exec($connection, $query);

// querying if user submitted the right password
$query = sprintf("SELECT 1 FROM users WHERE name='%s' AND pwd='%s';",
            addslashes($username), md5($password));
$result = pg_exec($connection, $query);

if (pg_numrows($result) > 0) {
    echo "Welcome, $username!";
}
else {
    echo "Authentication failed for $username.";
}

SQL Injection

Many web developers are unaware of how SQL queries can be tampered with, and assume that an SQL query is a trusted command. It means that SQL queries are able to circumvent access controls, thereby bypassing standard authentication and authorization checks, and sometimes SQL queries even may allow access to host operating system level commands.

Direct SQL Command Injection is a technique where an attacker creates or alters existing SQL commands to expose hidden data, or to override valuable ones, or even to execute dangerous system level commands on the database host. This is accomplished by the application taking user input and combining it with static parameters to build a SQL query. The following examples are based on true stories, unfortunately.

Owing to the lack of input validation and connecting to the database on behalf of a superuser or the one who can create users, the attacker may create a superuser in your database.
Example 5-6. Splitting the result set into pages ... and making superusers (PostgreSQL and MySQL)
$offset = argv[0]; // beware, no input validation! $query = "SELECT id, name FROM products ORDER BY name LIMIT 20 OFFSET $offset;"; // with PostgreSQL $result = pg_exec($conn, $query); // with MySQL $result = mysql_query($query);
Normal users click on the 'next', 'prev' links where the $offset is encoded into the URL. The script expects that the incoming $offset is decimal number. However, someone tries to break in with appending urlencode()'d form of the following to the URL

// in case of PostgreSQL
0;
insert into pg_shadow(usename,usesysid,usesuper,usecatupd,passwd)
    select 'crack', usesysid, 't','t','crack'
    from pg_shadow where usename='postgres';
--

// in case of MySQL
0;
UPDATE user SET Password=PASSWORD('crack') WHERE user='root';
FLUSH PRIVILEGES;

If it happened, then the script would present a superuser access to him. Note that 0; is to supply a valid offset to the original query and to terminate it.

Note: It is common technique to force the SQL parser to ignore the rest of the query written by the developer with -- which is the comment sign in SQL.

A feasible way to gain passwords is to circumvent your search result pages. What the attacker needs only is to try if there is any submitted variable used in SQL statement which is not handled properly. These filters can be set commonly in a preceding form to customize WHERE, ORDER BY, LIMIT and OFFSET clauses in SELECT statements. If your database supports the UNION construct, the attacker may try to append an entire query to the original one to list passwords from an arbitrary table. Using encrypted password fields is strongly encouraged.
Example 5-7. Listing out articles ... and some passwords (any database server)
$query = "SELECT id, name, inserted, size FROM products WHERE size = '$size' ORDER BY $order LIMIT $limit, $offset;"; $result = odbc_exec($conn, $query);
The static part of the query can be combined with another SELECT statement which reveals all passwords:

'
union select '1', concat(uname||'-'||passwd) as name, '1971-01-01', '0' from usertable;
--

If this query (playing with the ' and --) were assigned to one of the variables used in $query, the query beast awakened.

SQL UPDATEs are also subject to attacking your database. These queries are also threatened by chopping and appending an entirely new query to it. But the attacker might fiddle with the SET clause. In this case some schema information must be possessed to manipulate the query successfully. This can be acquired by examing the form variable names, or just simply brute forcing. There are not so many naming convention for fields storing passwords or usernames.
Example 5-8. From resetting a password ... to gaining more privileges (any database server)
$query = "UPDATE usertable SET pwd='$pwd' WHERE uid='$uid';";
But a malicious user sumbits the value ' or uid like'%admin%'; -- to $uid to change the admin's password, or simply sets $pwd to "hehehe', admin='yes', trusted=100 " (with a trailing space) to gain more privileges. Then, the query will be twisted:

// $uid == ' or uid like'%admin%'; --
$query = "UPDATE usertable SET pwd='...' WHERE uid='' or uid like '%admin%'; --";

// $pwd == "hehehe', admin='yes', trusted=100 "
$query = "UPDATE usertable SET pwd='hehehe', admin='yes', trusted=100 WHERE ...;"

A frightening example how operating system level commands can be accessed on some database hosts.
Example 5-9. Attacking the database host's operating system (MSSQL Server)
$query = "SELECT * FROM products WHERE id LIKE '%$prod%'"; $result = mssql_query($query);
If attacker submits the value a%' exec master..xp_cmdshell 'net user test testpass /ADD' -- to $prod, then the $query will be:

$query  = "SELECT * FROM products
                    WHERE id LIKE '%a%'
                    exec master..xp_cmdshell 'net user test testpass /ADD'--";
$result = mssql_query($query);

MSSQL Server executes the SQL statements in the batch including a command to add a new user to the local accounts database. If this application were running as sa and the MSSQLSERVER service is running with sufficient privileges, the attacker would now have an account with which to access this machine.

Note: Some of the examples above is tied to a specific database server. This does not mean that a similar attack is impossible against other products. Your database server may be so vulnerable in other manner.

Avoiding techniques

You may plead that the attacker must possess a piece of information about the database schema in most examples. You are right, but you never know when and how it can be taken out, and if it happens, your database may be exposed. If you are using an open source, or publicly available database handling package, which may belong to a content management system or forum, the intruders easily produce a copy of a piece of your code. It may be also a security risk if it is a poorly designed one.

These attacks are mainly based on exploiting the code not being written with security in mind. Never trust on any kind of input, especially which comes from the client side, even though it comes from a select box, a hidden input field or a cookie. The first example shows that such a blameless query can cause disasters.

Never connect to the database as a superuser or as the database owner. Use always customized users with very limited privileges.
Check if the given input has the expected data type. PHP has a wide range of input validating functions, from the simplest ones found in Variable Functions and in Character Type Functions (e.g. is_numeric(), ctype_digit() respectively) onwards the Perl compatible Regular Expressions support.

If the application waits for numerical input, consider to verify data with is_numeric(), or silently change its type using settype(), or use its numeric representation by sprintf().
Example 5-10. A more secure way to compose a query for paging
settype($offset, 'integer'); $query = "SELECT id, name FROM products ORDER BY name LIMIT 20 OFFSET $offset;"; // please note %d in the format string, using %s would be meaningless $query = sprintf("SELECT id, name FROM products ORDER BY name LIMIT 20 OFFSET %d;", $offset);

Quote each non numeric user input which is passed to the database with addslashes() or addcslashes(). See the first example. As the examples shows, quotes burnt into the static part of the query is not enough, and can be easily hacked.
Do not print out any database specific information, especially about the schema, by fair means or foul. See also Error Reporting and Error Handling and Logging Functions.
You may use stored procedures and previously defined cursors to abstract data access so that users do not directly access tables or views, but this solution has another impacts.

Besides these, you benefit from logging queries either within your script or by the database itself, if it supports. Obviously, the logging is unable to prevent any harmful attempt, but it can be helpful to trace back which application has been circumvented. The log is not useful by itself, but through the information it contains. The more detail is generally better.

Error Reporting

With PHP security, there are two sides to error reporting. One is beneficial to increasing security, the other is detrimental.

A standard attack tactic involves profiling a system by feeding it improper data, and checking for the kinds, and contexts, of the errors which are returned. This allows the system cracker to probe for information about the server, to determine possible weaknesses. For example, if an attacker had gleaned information about a page based on a prior form submission, they may attempt to override variables, or modify them:
Example 5-11. Attacking Variables with a custom HTML page
<form method="post" action="attacktarget?username=badfoo&password=badfoo"> <input type="hidden" name="username" value="badfoo"> <input type="hidden" name="password" value="badfoo"> </form>

The PHP errors which are normally returned can be quite helpful to a developer who is trying to debug a script, indicating such things as the function or file that failed, the PHP file it failed in, and the line number which the failure occured in. This is all information that can be exploited. It is not uncommon for a php developer to use show_source(), highlight_string(), or highlight_file() as a debugging measure, but in a live site, this can expose hidden variables, unchecked syntax, and other dangerous information. Especially dangerous is running code from known sources with built-in debugging handlers, or using common debugging techniques. If the attacker can determine what general technique you are using, they may try to brute-force a page, by sending various common debugging strings:
Example 5-12. Exploiting common debugging variables
<form method="post" action="attacktarget?errors=Y&showerrors=1"&debug=1"> <input type="hidden" name="errors" value="Y"> <input type="hidden" name="showerrors" value="1"> <input type="hidden" name="debug" value="1"> </form>

Regardless of the method of error handling, the ability to probe a system for errors leads to providing an attacker with more information.

For example, the very style of a generic PHP error indicates a system is running PHP. If the attacker was looking at an .html page, and wanted to probe for the back-end (to look for known weaknesses in the system), by feeding it the wrong data they may be able to determine that a system was built with PHP.

A function error can indicate whether a system may be running a specific database engine, or give clues as to how a web page or programmed or designed. This allows for deeper investigation into open database ports, or to look for specific bugs or weaknesses in a web page. By feeding different pieces of bad data, for example, an attacker can determine the order of authentication in a script, (from the line number errors) as well as probe for exploits that may be exploited in different locations in the script.

A filesystem or general PHP error can indicate what permissions the webserver has, as well as the structure and organization of files on the web server. Developer written error code can aggravate this problem, leading to easy exploitation of formerly "hidden" information.

There are three major solutions to this issue. The first is to scrutinize all functions, and attempt to compensate for the bulk of the errors. The second is to disable error reporting entirely on the running code. The third is to use PHP's custom error handling functions to create your own error handler. Depending on your security policy, you may find all three to be applicable to your situation.

One way of catching this issue ahead of time is to make use of PHP's own error_reporting(), to help you secure your code and find variable usage that may be dangerous. By testing your code, prior to deployment, with E_ALL, you can quickly find areas where your variables may be open to poisoning or modification in other ways. Once you are ready for deployment, by using E_NONE, you insulate your code from probing.
Example 5-13. Finding dangerous variables with E_ALL
<?php if ($username) { // Not initialized or checked before usage $good_login = 1; } if ($good_login == 1) { // If above test fails, not initialized or checked before usage fpassthru ("/highly/sensitive/data/index.html"); } ?>

Using Register Globals

One feature of PHP that can be used to enhance security is configuring PHP with register_globals = off. By turning off the ability for any user-submitted variable to be injected into PHP code, you can reduce the amount of variable poisoning a potential attacker may inflict. They will have to take the additional time to forge submissions, and your internal variables are effectively isolated from user submitted data.

While it does slightly increase the amount of effort required to work with PHP, it has been argued that the benefits far outweigh the effort.
Example 5-14. Working with register_globals=on
<?php if ($username) { // can be forged by a user in get/post/cookies $good_login = 1; } if ($good_login == 1) { // can be forged by a user in get/post/cookies, fpassthru ("/highly/sensitive/data/index.html"); } ?>

Example 5-15. Working with register_globals = off
<?php if($_COOKIE['username']){ // can only come from a cookie, forged or otherwise $good_login = 1; fpassthru ("/highly/sensitive/data/index.html"); } ?>
By using this wisely, it's even possible to take preventative measures to warn when forging is being attempted. If you know ahead of time exactly where a variable should be coming from, you can check to see if submitted data is coming from an inappropriate kind of submission. While it doesn't guarantee that data has not been forged, it does require an attacker to guess the right kind of forging.
Example 5-16. Detecting simple variable poisoning
<?php if ($_COOKIE['username'] && !$_POST['username'] && !$_GET['username'] ) { // Perform other checks to validate the user name... $good_login = 1; fpassthru ("/highly/sensitive/data/index.html"); } else { mail("admin@example.com", "Possible breakin attempt", $_SERVER['REMOTE_ADDR']); echo "Security violation, admin has been alerted."; exit; } ?>
Of course, simply turning off register_globals does not mean code is secure. For every piece of data that is submitted, it should also be checked in other ways.

User Submitted Data

The greatest weakness in many PHP programs is not inherent in the language itself, but merely an issue of code not being written with security in mind. For this reason, you should always take the time to consider the implications of a given piece of code, to ascertain the possible damage if an unexpected variable is submitted to it.
Example 5-17. Dangerous Variable Usage
<?php // remove a file from the user's home directory... or maybe // somebody else's? unlink ($evil_var); // Write logging of their access... or maybe an /etc/passwd entry? fputs ($fp, $evil_var); // Execute something trivial.. or rm -rf *? system ($evil_var); exec ($evil_var); ?>
You should always carefully examine your code to make sure that any variables being submitted from a web browser are being properly checked, and ask yourself the following questions:

Will this script only affect the intended files?
Can unusual or undesirable data be acted upon?
Can this script be used in unintended ways?
Can this be used in conjunction with other scripts in a negative manner?
Will any transactions be adequately logged?

By adequately asking these questions while writing the script, rather than later, you prevent an unfortunate re-write when you need to increase your security. By starting out with this mindset, you won't guarantee the security of your system, but you can help improve it.

You may also want to consider turning off register_globals, magic_quotes, or other convenience settings which may confuse you as to the validity, source, or value of a given variable. Working with PHP in error_reporting(E_ALL) mode can also help warn you about variables being used before they are checked or initialized (so you can prevent unusual data from being operated upon).

Hiding PHP

In general, security by obscurity is one of the weakest forms of security. But in some cases, every little bit of extra security is desirable.

A few simple techniques can help to hide PHP, possibly slowing down an attacker who is attempting to discover weaknesses in your system. By setting expose_php = off in your php.ini file, you reduce the amount of information available to them.

Another tactic is to configure web servers such as apache to parse different filetypes through PHP, either with an .htaccess directive, or in the apache configuration file itself. You can then use misleading file extensions:
Example 5-18. Hiding PHP as another language
# Make PHP code look like other code types AddType application/x-httpd-php .asp .py .pl
Or obscure it completely:
Example 5-19. Using unknown types for PHP extensions
# Make PHP code look like unknown types AddType application/x-httpd-php .bop .foo .133t
Or hide it as html code, which has a slight performance hit because all html will be parsed through the PHP engine:
Example 5-20. Using html types for PHP extensions
# Make all PHP code look like html AddType application/x-httpd-php .htm .html
For this to work effectively, you must rename your PHP files with the above extensions. While it is a form of security through obscurity, it's a minor preventative measure with few drawbacks.

Keeping Current

PHP, like any other large system, is under constant scrutiny and improvement. Each new version will often include both major and minor changes to enhance and repair security flaws, configuration mishaps, and other issues that will affect the overall security and stability of your system.

Like other system-level scripting languages and programs, the best approach is to update often, and maintain awareness of the latest versions and their changes.

II. Language Reference

Table of Contents
6. Basic syntax
7. Types
8. Variables
9. Constants
10. Expressions
11. Operators
12. Control Structures
13. Functions
14. Classes and Objects
15. References Explained

Chapter 6. Basic syntax

Escaping from HTML

When PHP parses a file, it simply passes the text of the file through until it encounters one of the special tags which tell it to start interpreting the text as PHP code. The parser then executes all the code it finds, up until it runs into a PHP closing tag, which tells the parser to just start passing the text through again. This is the mechanism which allows you to embed PHP code inside HTML: everything outside the PHP tags is left utterly alone, while everything inside is parsed as code.

There are four sets of tags which can be used to denote blocks of PHP code. Of these, only two (<?php. . .?> and <script language="php">. . .</script>) are always available; the others can be turned on or off from the php.ini configuration file. While the short-form tags and ASP-style tags may be convenient, they are not as portable as the longer versions. Also, if you intend to embed PHP code in XML or XHTML, you will need to use the <?php. . .?> form to conform to the XML.

The tags supported by PHP are:

Example 6-1. Ways of escaping from HTML
1. <?php echo("if you want to serve XHTML or XML documents, do like this\n"); ?> 2. <? echo ("this is the simplest, an SGML processing instruction\n"); ?> <?= expression ?> This is a shortcut for "<? echo expression ?>" 3. <script language="php"> echo ("some editors (like FrontPage) don't like processing instructions"); </script> 4. <% echo ("You may optionally use ASP-style tags"); %> <%= $variable; # This is a shortcut for "<% echo . . ." %>

The first way, <?php. . .?>, is the preferred method, as it allows the use of PHP in XML-conformant code such as XHTML.

The second way is not available always. Short tags are available only when they have been enabled. This can be done via the short_tags() function (PHP 3 only), by enabling the short_open_tag configuration setting in the PHP config file, or by compiling PHP with the --enable-short-tags option to configure. Even if it is enabled by default in php.ini-dist, use of short tags are discouraged.

The fourth way is only available if ASP-style tags have been enabled using the asp_tags configuration setting.

Note: Support for ASP-style tags was added in 3.0.4.

Note: Using short tags should be avoided when developing applications or libraries that are meant for redistribution, or deployment on PHP servers which are not under your control, because short tags may not be supported on the target server. For portable, redistributable code, be sure not to use short tags.

The closing tag for the block will include the immediately trailing newline if one is present. Also, the closing tag automatically implies a semicolon; you do not need to have a semicolon terminating the last line of a PHP block.

PHP allows you to use structures like this:
Example 6-2. Advanced escaping
<?php if ($expression) { ?> <strong>This is true.</strong> <?php } else { ?> <strong>This is false.</strong> <?php } ?>
This works as expected, because when PHP hits the ?> closing tags, it simply starts outputting whatever it finds until it hits another opening tag. The example given here is contrived, of course, but for outputting large blocks of text, dropping out of PHP parsing mode is generally more efficient than sending all of the text through echo() or print() or somesuch.

Instruction separation

Instructions are separated the same as in C or Perl - terminate each statement with a semicolon.

The closing tag (?>) also implies the end of the statement, so the following are equivalent:

<?php
    echo "This is a test";
?>

<?php echo "This is a test" ?>

Comments

PHP supports 'C', 'C++' and Unix shell-style comments. For example:

<?php
    echo "This is a test"; // This is a one-line c++ style comment
    /* This is a multi line comment
       yet another line of comment */
    echo "This is yet another test";
    echo "One Final Test"; # This is shell-style style comment
?>

The "one-line" comment styles actually only comment to the end of the line or the current block of PHP code, whichever comes first.

<h1>This is an <?php # echo "simple";?> example.</h1>
<p>The header above will say 'This is an example'.

You should be careful not to nest 'C' style comments, which can happen when commenting out large blocks.

<?php
 /* 
    echo "This is a test"; /* This comment will cause a problem */
 */
?>

The one-line comment styles actually only comment to the end of the line or the current block of PHP code, whichever comes first. This means that HTML code after // ?> WILL be printed: ?> skips out of the PHP mode and returns to HTML mode, and // cannot influence that.

Chapter 7. Types

Introduction

PHP supports eight primitive types.

Four scalar types:

boolean
integer
floating-point number (float)
string

Two compound types:

array
object

And finally two special types:

resource
NULL

Note: In this manual you'll often find mixed parameters. This pseudo-type indicates multiple possibilities for that parameter.

The type of a variable is usually not set by the programmer; rather, it is decided at runtime by PHP depending on the context in which that variable is used.

Note: If you want to check out the type and value of a certain expression, use var_dump().
If you simply want a human-readable representation of the type for debugging, use gettype(). To check for a certain type, do not use gettype(), but use the is_type functions.

If you would like to force a variable to be converted to a certain type, you may either cast the variable or use the settype() function on it.

Note that a variable may behave in different manners in certain situations, depending on what type it is at the time. For more information, see the section on Type Juggling.

Booleans

This is the easiest type. A boolean expresses a truth value. It can be either TRUE or FALSE.

Note: The boolean type was introduced in PHP 4.

Syntax

To specify a boolean literal, use either the keyword TRUE or FALSE. Both are case-insensitive.

$foo = True; // assign the value TRUE to $foo

Usually you use some kind of operator which returns a boolean value, and then pass it on to a control structure.

// == is an operator which returns a boolean
if ($action == "show_version") {
    echo "The version is 1.23";
}

// this is not necessary:
if ($show_separators == TRUE) {
    echo "<hr>\n";
}

// because you can simply type this:
if ($show_separators) {
    echo "<hr>\n";
}

Converting to boolean

To explicitly convert a value to boolean, use either the (bool) or the (boolean) cast. However, in most cases you do not need to use the cast, since a value will be automatically converted if an operator, function or control structure requires a boolean argument.

Integers

An integer is a number of the set Z = {..., -2, -1, 0, 1, 2, ...}.

Syntax

Integers can be specified in decimal (10-based), hexadecimal (16-based) or octal (8-based) notation, optionally preceded by a sign (- or +).

If you use the octal notation, you must precede the number with a 0 (zero), to use hexadecimal notation precede the number with 0x.
Example 7-1. Integer literals
$a = 1234; # decimal number $a = -123; # a negative number $a = 0123; # octal number (equivalent to 83 decimal) $a = 0x1A; # hexadecimal number (equivalent to 26 decimal)
The size of an integer is platform-dependent, although a maximum value of about two billion is the usual value (that's 32 bits signed). PHP does not support unsigned integers.

Integer overflow

If you specify a number beyond the bounds of the integer type, it will be interpreted as a float instead. Also, if you perform an operation that results in a number beyond the bounds of the integer type, a float will be returned instead.

$large_number =  2147483647;
var_dump($large_number);
// output: int(2147483647)

$large_number =  2147483648;
var_dump($large_number);
// output: float(2147483648)

// this goes also for hexadecimal specified integers:
var_dump( 0x80000000 );
// output: float(2147483648)

$million = 1000000;
$large_number =  50000 * $million;
var_dump($large_number);
// output: float(50000000000)

Warning

Unfortunately, there was a bug in PHP so that this does not always work correctly when there are negative numbers involved. For example: when you do -50000 * $million, the result will be -429496728. However, when both operands are positive there is no problem.

This is solved in PHP 4.1.0.

There is no integer division operator in PHP. 1/2 yields the float 0.5.

var_dump( 25/7 );
// output: float(3.5714285714286)

Converting to integer

To explicitly convert a value to integer, use either the (int) or the (integer) cast. However, in most cases you do not need to use the cast, since a value will be automatically converted if an operator, function or control structure requires a integer argument.

From booleans

FALSE will yield 0 (zero), and TRUE will yield 1 (one).

From floating point numbers

When converting from float to integer, the number will be rounded towards zero.

If the float is beyond the boundaries of integer (usually +/- 2.15e+9 = 2^31), the result is undefined, since the float hasn't got enough precision to give an exact integer result. No warning, not even a notice will be issued in this case!

Warning

Never cast an unknown fraction to integer, as this can sometimes lead to unexpected results.

echo (int) ( (0.1+0.7) * 10 ); // echoes 7!

See for more information the warning about float-precision.

From strings

See String conversion

From other types

Caution

Behaviour of converting to integer is undefined for other types. Currently, the behaviour is the same as if the value was first converted to boolean. However, do not rely on this behaviour, as it can change without notice.

Floating point numbers

Floating point numbers (AKA "floats", "doubles" or "real numbers") can be specified using any of the following syntaxes:
$a = 1.234; $a = 1.2e3; $a = 7E-10;
The size of a float is platform-dependent, although a maximum of ~1.8e308 with a precision of roughly 14 decimal digits is a common value (that's 64 bit IEEE format).

Floating point precision

It is quite usual that simple decimal fractions like 0.1 or 0.7 cannot be converted into their internal binary counterparts without a little loss of precision. This can lead to confusing results: for example, floor((0.1+0.7)*10) will usually return 7 instead of the expected 8 as the result of the internal representation really being something like 7.9999999999....

This is related to the fact that it is impossible to exactly express some fractions in decimal notation with a finite number of digits. For instance, 1/3 in decimal form becomes 0.3333333. . ..

So never trust floating number results to the last digit and never compare floating point numbers for equality. If you really need higher precision, you should use the arbitrary precision math functions or gmp functions instead.

Strings

A string is series of characters. In PHP, a character is the same as a byte, that is, there are exactly 256 different characters possible. This also implies that PHP has no native support of Unicode.

Note: It is no problem for a string to become very large. There is no practical bound to the size of strings imposed by PHP, so there is no reason at all to worry about long strings.

Syntax

A string literal can be specified in three different ways.

single quoted
double quoted
heredoc syntax

Single quoted

The easiest way to specify a simple string is to enclose it in single quotes (the character ').

To specify a literal single quote, you will need to escape it with a backslash (\), like in many other languages. If a backslash needs to occur before a single quote or at the end of the string, you need to double it. Note that if you try to escape any other character, the backslash too will be printed! So usually there is no need to escape the backslash itself.

Note: In PHP 3, a warning will be issued at the E_NOTICE level when this happens.

Note: Unlike the two other syntaxes, variables will not be expanded when they occur in single quoted strings.

echo 'this is a simple string';
echo 'You can also have embedded newlines in strings,
like this way.';
echo 'Arnold once said: "I\'ll be back"';
// output: ... "I'll be back"
echo 'Are you sure you want to delete C:\\*.*?';
// output: ... delete C:\*.*?
echo 'Are you sure you want to delete C:\*.*?';
// output: ... delete C:\*.*?
echo 'I am trying to include at this point: \n a newline';
// output: ... this point: \n a newline

Double quoted

If the string is enclosed in double-quotes ("), PHP understands more escape sequences for special characters:

Table 7-1. Escaped characters

sequence	meaning
`\n`	linefeed (LF or 0x0A (10) in ASCII)
`\r`	carriage return (CR or 0x0D (13) in ASCII)
`\t`	horizontal tab (HT or 0x09 (9) in ASCII)
`\\`	backslash
`\$`	dollar sign
`\"`	double-quote
`\[0-7]{1,3}`	the sequence of characters matching the regular expression is a character in octal notation
`\x[0-9A-Fa-f]{1,2}`	the sequence of characters matching the regular expression is a character in hexadecimal notation

Again, if you try to escape any other character, the backslash will be printed too!

But the most important pre of double-quoted strings is the fact that variable names will be expanded. See string parsing for details.

Heredoc

Another way to delimit strings is by using heredoc syntax ("<<<"). One should provide an identifier after <<<, then the string, and then the same identifier to close the quotation.

The closing identifier must begin in the first column of the line. Also, the identifier used must follow the same naming rules as any other label in PHP: it must contain only alphanumeric characters and underscores, and must start with a non-digit character or underscore.

Warning

It is very important to note that the line with the closing identifier contains no other characters, except possibly a semicolon (;). That means especially that the identifier may not be indented, and there may not be any spaces or tabs after or before the semicolon.

Heredoc text behaves just like a double-quoted string, without the double-quotes. This means that you do not need to escape quotes in your here docs, but you can still use the escape codes listed above. Variables are expanded, but the same care must be taken when expressing complex variables inside a here doc as with strings.
Example 7-2. Heredoc string quoting example
<?php $str = <<<EOD Example of string spanning multiple lines using heredoc syntax. EOD; /* More complex example, with variables. */ class foo { var $foo; var $bar; function foo() { $this->foo = 'Foo'; $this->bar = array('Bar1', 'Bar2', 'Bar3'); } } $foo = new foo(); $name = 'MyName'; echo <<<EOT My name is "$name". I am printing some $foo->foo. Now, I am printing some {$foo->bar[1]}. This should print a capital 'A': \x41 EOT; ?>

Note: Heredoc support was added in PHP 4.

Variable parsing

When a string is specified in double quotes or with heredoc, variables are parsed within it.

There are two types of syntax, a simple one and a complex one. The simple syntax is the most common and convenient, it provides a way to parse a variable, an array value, or an object property.

The complex syntax was introduced in PHP 4, and can be recognised by the curly braces surrounding the expression.

Simple syntax

If a dollar sign ($) is encountered, the parser will greedily take as much tokens as possible to form a valid variable name. Enclose the variable name in curly braces if you want to explicitly specify the end of the name.

$beer = 'Heineken';
echo "$beer's taste is great"; // works, "'" is an invalid character for varnames
echo "He drank some $beers"; // won't work, 's' is a valid character for varnames
echo "He drank some ${beer}s"; // works

Similarly, you can also have an array index or an object property parsed. With array indices, the closing square bracket (]) marks the end of the index. For object properties the same rules apply as to simple variables, though with object properties there doesn't exist a trick like the one with variables.

$fruits = array( 'strawberry' => 'red' , 'banana' => 'yellow' );

// note that this works differently outside string-quotes.
echo "A banana is $fruits[banana].";

echo "This square is $square->width meters broad.";

// Won't work. For a solution, see the complex syntax.
echo "This square is $square->width00 centimeters broad.";

For anything more complex, you should use the complex syntax.

Complex (curly) syntax

This isn't called complex because the syntax is complex, but because you can include complex expressions this way.

In fact, you can include any value that is in the namespace in strings with this syntax. You simply write the expression the same way as you would outside the string, and then include it in { and }. Since you can't escape '{', this syntax will only be recognised when the $ is immediately following the {. (Use "{\$" or "\{$" to get a literal "{$"). Some examples to make it clear:

$great = 'fantastic';
echo "This is { $great}"; // won't work, outputs: This is { fantastic}
echo "This is {$great}";  // works, outputs: This is fantastic
echo "This square is {$square->width}00 centimeters broad."; 
echo "This works: {$arr[4][3]}";     

// This is wrong for the same reason
// as $foo[bar] is wrong outside a string. 
echo "This is wrong: {$arr[foo][3]}"; 

echo "You should do it this way: {$arr['foo'][3]}";
echo "You can even write {$obj->values[3]->name}";
echo "This is the value of the var named $name: {${$name}}";

String access by character

Characters within strings may be accessed by specifying the zero-based offset of the desired character after the string in curly braces.

Note: For backwards compatibility, you can still use the array-braces. However, this syntax is deprecated as of PHP 4.

Example 7-3. Some string examples
<?php /* Assigning a string. */ $str = "This is a string"; /* Appending to it. */ $str = $str . " with some more text"; /* Another way to append, includes an escaped newline. */ $str .= " and a newline at the end.\n"; /* This string will end up being '<p>Number: 9</p>' */ $num = 9; $str = "<p>Number: $num</p>"; /* This one will be '<p>Number: $num</p>' */ $num = 9; $str = '<p>Number: $num</p>'; /* Get the first character of a string */ $str = 'This is a test.'; $first = $str{0}; /* Get the last character of a string. */ $str = 'This is still a test.'; $last = $str{strlen($str)-1}; ?>

Useful functions

Strings may be concatenated using the '.' (dot) operator. Note that the '+' (addition) operator will not work for this. Please see String operators for more information.

There are a lot of useful functions for string modification.

See the string functions section for general functions, the regular expression functions for advanced find&replacing (in two tastes: Perl and POSIX extended).

There are also functions for URL-strings, and functions to encrypt/decrypt strings (mcrypt and mhash).

Finally, if you still didn't find what you're looking for, see also the character type functions.

String conversion

When a string is evaluated as a numeric value, the resulting value and type are determined as follows.

The string will evaluate as a float if it contains any of the characters '.', 'e', or 'E'. Otherwise, it will evaluate as an integer.

The value is given by the initial portion of the string. If the string starts with valid numeric data, this will be the value used. Otherwise, the value will be 0 (zero). Valid numeric data is an optional sign, followed by one or more digits (optionally containing a decimal point), followed by an optional exponent. The exponent is an 'e' or 'E' followed by one or more digits.

$foo = 1 + "10.5";              // $foo is float (11.5)
$foo = 1 + "-1.3e3";            // $foo is float (-1299)
$foo = 1 + "bob-1.3e3";         // $foo is integer (1)
$foo = 1 + "bob3";              // $foo is integer (1)
$foo = 1 + "10 Small Pigs";     // $foo is integer (11)
$foo = 4 + "10.2 Little Piggies"; // $foo is float (14.2)
$foo = "10.0 pigs " + 1;        // $foo is float (11)
$foo = "10.0 pigs " + 1.0;      // $foo is float (11)

For more information on this conversion, see the Unix manual page for strtod(3).

If you would like to test any of the examples in this section, you can cut and paste the examples and insert the following line to see for yourself what's going on:

echo "\$foo==$foo; type is " . gettype ($foo) . "<br />\n";

Arrays

An array in PHP is actually an ordered map. A map is a type that maps values to keys. This type is optimized in several ways, so you can use it as a real array, or a list (vector), hashtable (which is an implementation of a map), dictionary, collection, stack, queue and probably more. Because you can have another PHP-array as a value, you can also quite easily simulate trees.

Explanation of those structures is beyond the scope of this manual, but you'll find at least one example for each of those structures. For more information about those structures, we refer you to external literature about this broad topic.

Syntax

Specifying with array()

An array can be created by the array() language-construct. It takes a certain number of comma-separated key => value pairs.

A key is either an integer or a string. If a key is the standard representation of an integer, it will be interpreted as such (i.e. "8" will be interpreted as 8, while "08" will be interpreted as "08").

A value can be anything.

If you omit a key, the maximum of the integer-indices is taken, and the new key will be that maximum + 1. As integers can be negative, this is also true for negative indices. Having e.g. the highest index being -6 will result in being -5 the new key. If no integer-indices exist yet, the key will be 0 (zero). If you specify a key that already has a value assigned to it, that value will be overwritten.

Using true as a key will evalute to integer 1 as key. Using false as a key will evalute to integer 0 as key. Using NULL as a key will evaluate to an empty string. Using an emptry string as key will create (or overwrite) a key with an empty string and its value, it is not the same as using empty brackets.

You cannot use arrays or objects as keys. Doing so will result in a warning: Illegal offset type.

array( [key =>] value , ... ) // key is either string or nonnegative integer // value can be anything

Creating/modifying with square-bracket syntax

You can also modify an existing array, by explicitly setting values.

This is done by assigning values to the array while specifying the key in brackets. You can also omit the key, add an empty pair of brackets ("[]") to the variable-name in that case.
$arr[key] = value; $arr[] = value; // key is either string or nonnegative integer // value can be anything
If $arr doesn't exist yet, it will be created. So this is also an alternative way to specify an array. To change a certain value, just assign a new value to it. If you want to remove a key/value pair, you need to unset() it.

Useful functions

There are quite some useful function for working with arrays, see the array-functions section.

Note: The unset() function allows unsetting keys of an array. Be aware that the array will NOT be reindexed.
$a = array( 1 => 'one', 2 => 'two', 3 => 'three' );
unset( $a[2] );
/* will produce an array that would have been defined as
   $a = array( 1=>'one', 3=>'three');
   and NOT
   $a = array( 1 => 'one', 2 => 'three');
*/

The foreach control structure exists specifically for arrays. It provides an easy way to traverse an array.

Array do's and don'ts

Why is `$foo[bar]` wrong?

You should always use quotes around an associative array index. For example, use $foo['bar'] and not $foo[bar]. But why is $foo[bar] wrong? You might have seen the following syntax in old scripts:

$foo[bar] = 'enemy';
echo $foo[bar];
// etc

This is wrong, but it works. Then, why is it wrong? The reason is that this code has an undefined constant (bar) rather than a string ('bar' - notice the quotes), and PHP may in future define constants which, unfortunately for your code, have the same name. It works, because the undefined constant gets converted to a string of the same name.

As stated in the syntax section, there must be an expression between the square brackets ('[' and ']'). That means that you can write things like this:

echo $arr[ foo(true) ];

This is an example of using a function return value as the array index. PHP knows also about constants, and you may have seen the E_* before.

$error_descriptions[E_ERROR] = "A fatal error has occured";
$error_descriptions[E_WARNING] = "PHP issued a warning";
$error_descriptions[E_NOTICE] = "This is just an informal notice";

Note that E_ERROR is also a valid identifier, just like bar in the first example. But the last example is in fact the same as writing:

$error_descriptions[1] = "A fatal error has occured";
$error_descriptions[2] = "PHP issued a warning";
$error_descriptions[8] = "This is just an informal notice";

because E_ERROR equals 1, etc.

Then, how is it possible that $foo[bar] works? It works, because bar is due to its syntax expected to be a constant expression. However, in this case no constant with the name bar exists. PHP now assumes that you meant bar literally, as the string "bar", but that you forgot to write the quotes.

So why is it bad then?

At some point in the future, the PHP team might want to add another constant or keyword, and then you get in trouble. For example, you already cannot use the words empty and default this way, since they are special reserved keywords.

Note: When you turn error_reporting to E_ALL, you will see that PHP generates notices whenever an index is used which is not defined (put the line error_reporting(E_ALL); in your script).

Note: Inside a double-quoted string, an other syntax is valid. See variable parsing in strings for more details.

Examples

The array type in PHP is very versatile, so here will be some examples to show you the full power of arrays.

// this
$a = array( 'color' => 'red'
          , 'taste' => 'sweet'
          , 'shape' => 'round'
          , 'name'  => 'apple'
          ,            4        // key will be 0
          );

// is completely equivalent with
$a['color'] = 'red';
$a['taste'] = 'sweet';
$a['shape'] = 'round';
$a['name'] = 'apple';
$a[]        = 4;        // key will be 0

$b[] = 'a';
$b[] = 'b';
$b[] = 'c';
// will result in the array array( 0 => 'a' , 1 => 'b' , 2 => 'c' ),
// or simply array('a', 'b', 'c')

Example 7-4. Using array()

// Array as (property-)map
$map = array( 'version'    => 4
            , 'OS'         => 'Linux'
            , 'lang'       => 'english'
            , 'short_tags' => true
            );
            
// strictly numerical keys
$array = array( 7
              , 8
              , 0
              , 156
              , -10
              );
// this is the same as array( 0 => 7, 1 => 8, ...)

$switching = array(         10 // key = 0
                  , 5    =>  6
                  , 3    =>  7 
                  , 'a'  =>  4
                  ,         11 // key = 6 (maximum of integer-indices was 5)
                  , '8'  =>  2 // key = 8 (integer!)
                  , '02' => 77 // key = '02'
                  , 0    => 12 // the value 10 will be overwritten by 12
                  );
                  
// empty array
$empty = array();

Example 7-5. Collection

$colors = array('red','blue','green','yellow');

foreach ( $colors as $color ) {
    echo "Do you like $color?\n";
}

/* output:
Do you like red?
Do you like blue?
Do you like green?
Do you like yellow?
*/

Note that it is currently not possible to change the values of the array directly in such a loop. A workaround is the following:
Example 7-6. Collection
foreach ($colors as $key => $color) { // won't work: //$color = strtoupper($color); //works: $colors[$key] = strtoupper($color); } print_r($colors); /* output: Array ( [0] => RED [1] => BLUE [2] => GREEN [3] => YELLOW ) */

This example creates a one-based array.
Example 7-7. One-based index
$firstquarter = array(1 => 'January', 'February', 'March'); print_r($firstquarter); /* output: Array ( [1] => 'January' [2] => 'February' [3] => 'March' ) */

Example 7-8. Filling real array

// fill an array with all items from a directory
$handle = opendir('.');
while ($file = readdir($handle)) 
{
    $files[] = $file;
}
closedir($handle);

Arrays are ordered. You can also change the order using various sorting-functions. See array-functions for more information.

Example 7-9. Sorting array

sort($files);
print_r($files);

Because the value of an array can be everything, it can also be another array. This way you can make recursive and multi-dimensional arrays.

Example 7-10. Recursive and multi-dimensional arrays

$fruits = array ( "fruits"  => array ( "a" => "orange"
                                     , "b" => "banana"
                                     , "c" => "apple"
                                     )
                , "numbers" => array ( 1
                                     , 2
                                     , 3
                                     , 4
                                     , 5
                                     , 6
                                     )
                , "holes"   => array (      "first"
                                     , 5 => "second"
                                     ,      "third"
                                     )
                );

Objects

Object Initialization

To initialize an object, you use the new statement to instantiate the object to a variable.

<?php
class foo
{
    function do_foo()
    {
        echo "Doing foo."; 
    }
}

$bar = new foo;
$bar->do_foo();
?>

For a full discussion, please read the section Classes and Objects.

Resource

A resource is a special variable, holding a reference to an external resource. Resources are created and used by special functions. See the appendix for a listing of all these functions and the corresponding resource types.

Note: The resource type was introduced in PHP 4

Freeing resources

Due to the reference-counting system introduced with PHP4's Zend-engine, it is automatically detected when a resource is no longer referred to (just like Java). When this is the case, all resources that were in use for this resource are made free by the garbage collector. For this reason, it is rarely ever necessary to free the memory manually by using some free_result function.

Note: Persistent database-links are special, they are not destroyed by the gc. See also persistent links

NULL

The special NULL value represents that a variable has no value. NULL is the only possible value of type NULL.

Note: The null type was introduced in PHP 4

A variable is considered to be NULL if

it has been assigned the constant NULL.
it has not been set to any value yet.
it has been unset().

Syntax

There is only one value of type NULL, and that is the case-insensitive keyword NULL.

$var = NULL;

Type Juggling

PHP does not require (or support) explicit type definition in variable declaration; a variable's type is determined by the context in which that variable is used. That is to say, if you assign a string value to variable var, var becomes a string. If you then assign an integer value to var, it becomes an integer.

An example of PHP's automatic type conversion is the addition operator '+'. If any of the operands is a float, then all operands are evaluated as floats, and the result will be a float. Otherwise, the operands will be interpreted as integers, and the result will also be an integer. Note that this does NOT change the types of the operands themselves; the only change is in how the operands are evaluated.

$foo = "0";  // $foo is string (ASCII 48)

$foo += 2;   // $foo is now an integer (2)
$foo = $foo + 1.3;  // $foo is now a float (3.3)
$foo = 5 + "10 Little Piggies"; // $foo is integer (15)
$foo = 5 + "10 Small Pigs";     // $foo is integer (15)

If the last two examples above seem odd, see String conversion.

If you wish to force a variable to be evaluated as a certain type, see the section on Type casting. If you wish to change the type of a variable, see settype().

If you would like to test any of the examples in this section, you can use the var_dump() function.

Note: The behaviour of an automatic conversion to array is currently undefined.
$a = "1";     // $a is a string
$a[0] = "f";  // What about string offsets? What happens?
Since PHP supports indexing into strings via offsets using the same syntax as array indexing, the example above leads to a problem: should $a become an array with its first element being "f", or should "f" become the first character of the string $a?
For this reason, as of PHP 3.0.12 and PHP 4.0b3-RC4, the result of this automatic conversion is considered to be undefined. Fixes are, however, being discussed.

Type Casting

Type casting in PHP works much as it does in C: the name of the desired type is written in parentheses before the variable which is to be cast.

$foo = 10;   // $foo is an integer
$bar = (float) $foo;   // $bar is a float

The casts allowed are:

(int), (integer) - cast to integer
(bool), (boolean) - cast to boolean
(float), (double), (real) - cast to float
(string) - cast to string
(array) - cast to array
(object) - cast to object

Note: Instead of casting a variable to string, you can also enclose the variable in double quotes.

Note that tabs and spaces are allowed inside the parentheses, so the following are functionally equivalent:

$foo = (int) $bar;
$foo = ( int ) $bar;

It may not be obvious exactly what will happen when casting between certain types. For more info, see these sections:

Converting to boolean
Converting to integer

When casting or forcing a conversion from array to string, the result will be the word Array. When casting or forcing a conversion from object to string, the result will be the word Object.

When casting from a scalar or a string variable to an array, the variable will become the first element of the array:

$var = 'ciao';
$arr = (array) $var;
echo $arr[0];  // outputs 'ciao'

When casting from a scalar or a string variable to an object, the variable will become an attribute of the object; the attribute name will be 'scalar':

$var = 'ciao';
$obj = (object) $var;
echo $obj->scalar;  // outputs 'ciao'

Chapter 8. Variables

Basics

Variables in PHP are represented by a dollar sign followed by the name of the variable. The variable name is case-sensitive.

Variable names follow the same rules as other labels in PHP. A valid variable name starts with a letter or underscore, followed by any number of letters, numbers, or underscores. As a regular expression, it would be expressed thus: '[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*'

Note: For our purposes here, a letter is a-z, A-Z, and the ASCII characters from 127 through 255 (0x7f-0xff).

<?php
$var = "Bob";
$Var = "Joe";
echo "$var, $Var";      // outputs "Bob, Joe"

$4site = 'not yet';     // invalid; starts with a number
$_4site = 'not yet';    // valid; starts with an underscore
$täyte = 'mansikka';    // valid; 'ä' is ASCII 228.
?>

In PHP 3, variables are always assigned by value. That is to say, when you assign an expression to a variable, the entire value of the original expression is copied into the destination variable. This means, for instance, that after assigning one variable's value to another, changing one of those variables will have no effect on the other. For more information on this kind of assignment, see the chapter on Expressions.

PHP 4 offers another way to assign values to variables: assign by reference. This means that the new variable simply references (in other words, "becomes an alias for" or "points to") the original variable. Changes to the new variable affect the original, and vice versa. This also means that no copying is performed; thus, the assignment happens more quickly. However, any speedup will likely be noticed only in tight loops or when assigning large arrays or objects.

To assign by reference, simply prepend an ampersand (&) to the beginning of the variable which is being assigned (the source variable). For instance, the following code snippet outputs 'My name is Bob' twice:

<?php
$foo = 'Bob';              // Assign the value 'Bob' to $foo
$bar = &$foo;              // Reference $foo via $bar.
$bar = "My name is $bar";  // Alter $bar...
echo $bar;
echo $foo;                 // $foo is altered too.
?>

One important thing to note is that only named variables may be assigned by reference.

<?php
$foo = 25;
$bar = &$foo;      // This is a valid assignment.
$bar = &(24 * 7);  // Invalid; references an unnamed expression.

function test()
{
   return 25;
}

$bar = &test();    // Invalid.
?>

Predefined variables

PHP provides a large number of predefined variables to any script which it runs. Many of these variables, however, cannot be fully documented as they are dependent upon which server is running, the version and setup of the server, and other factors. Some of these variables will not be available when PHP is run on the command line. For a listing of these variables, please see the section on Reserved Predefined Variables.

Warning

In PHP 4.2.0 and later, the default value for the PHP directive register_globals is off. This is a major change in PHP. Having register_globals off affects the set of predefined variables available in the global scope. For example, to get DOCUMENT_ROOT you'll use $_SERVER['DOCUMENT_ROOT'] instead of $DOCUMENT_ROOT, or $_GET['id'] from the URL http://www.example.com/test.php?id=3 instead of $id, or $_ENV['HOME'] instead of $HOME.

For related information on this change, read the configuration entry for register_globals, the security chapter on Using Register Globals , as well as the PHP 4.1.0 and 4.2.0 Release Announcements.

Using the available PHP Reserved Predefined Variables, like the superglobal arrays, is preferred.

From version 4.1.0 onward, PHP provides an additional set of predefined arrays containing variables from the web server (if applicable), the environment, and user input. These new arrays are rather special in that they are automatically global--i.e., automatically available in every scope. For this reason, they are often known as 'autoglobals' or 'superglobals'. (There is no mechanism in PHP for user-defined superglobals.) The superglobals are listed below; however, for a listing of their contents and further discussion on PHP predefined variables and their natures, please see the section Reserved Predefined Variables. Also, you'll notice how the older predefined variables ($HTTP_*_VARS) still exist.

If certain variables in variables_order are not set, their appropriate PHP predefined arrays are also left empty.

PHP Superglobals

$GLOBALS: Contains a reference to every variable which is currently available within the global scope of the script. The keys of this array are the names of the global variables. $GLOBALS has existed since PHP 3.
$_SERVER: Variables set by the web server or otherwise directly related to the execution environment of the current script. Analogous to the old $HTTP_SERVER_VARS array (which is still available, but deprecated).
$_GET: Variables provided to the script via HTTP GET. Analogous to the old $HTTP_GET_VARS array (which is still available, but deprecated).
$_POST: Variables provided to the script via HTTP POST. Analogous to the old $HTTP_POST_VARS array (which is still available, but deprecated).
$_COOKIE: Variables provided to the script via HTTP cookies. Analogous to the old $HTTP_COOKIE_VARS array (which is still available, but deprecated).
$_FILES: Variables provided to the script via HTTP post file uploads. Analogous to the old $HTTP_POST_FILES array (which is still available, but deprecated). See POST method uploads for more information.
$_ENV: Variables provided to the script via the environment. Analogous to the old $HTTP_ENV_VARS array (which is still available, but deprecated).
$_REQUEST: Variables provided to the script via any user input mechanism, and which therefore cannot be trusted. The presence and order of variable inclusion in this array is defined according to the variables_order configuration directive. This array has no direct analogue in versions of PHP prior to 4.1.0. See also import_request_variables().
Note: When running on the command line , this will not include the argv and argc entries; these are present in the $_SERVER array.
$_SESSION: Variables which are currently registered to a script's session. Analogous to the old $HTTP_SESSION_VARS array (which is still available, but deprecated). See the Session handling functions section for more information.

Variable scope

The scope of a variable is the context within which it is defined. For the most part all PHP variables only have a single scope. This single scope spans included and required files as well. For example:

<?php
$a = 1;
include "b.inc";
?>

Here the $a variable will be available within the included b.inc script. However, within user-defined functions a local function scope is introduced. Any variable used inside a function is by default limited to the local function scope. For example:

<?php
$a = 1; /* global scope */ 

function Test()
{ 
    echo $a; /* reference to local scope variable */ 
} 

Test();
?>

This script will not produce any output because the echo statement refers to a local version of the $a variable, and it has not been assigned a value within this scope. You may notice that this is a little bit different from the C language in that global variables in C are automatically available to functions unless specifically overridden by a local definition. This can cause some problems in that people may inadvertently change a global variable. In PHP global variables must be declared global inside a function if they are going to be used in that function. An example:

<?php
$a = 1;
$b = 2;

function Sum()
{
    global $a, $b;

    $b = $a + $b;
} 

Sum();
echo $b;
?>

The above script will output "3". By declaring $a and $b global within the function, all references to either variable will refer to the global version. There is no limit to the number of global variables that can be manipulated by a function.

A second way to access variables from the global scope is to use the special PHP-defined $GLOBALS array. The previous example can be rewritten as:

<?php
$a = 1;
$b = 2;

function Sum()
{
    $GLOBALS["b"] = $GLOBALS["a"] + $GLOBALS["b"];
} 

Sum();
echo $b;
?>

The $GLOBALS array is an associative array with the name of the global variable being the key and the contents of that variable being the value of the array element. Notice how $GLOBALS exists in any scope, this is because $GLOBALS is a superglobal. Here's an example demonstrating the power of superglobals:

<?php
function test_global()
{
    // Most predefined variables aren't "super" and require 
    // 'global' to be available to the functions local scope.
    global $HTTP_POST_VARS;
    
    print $HTTP_POST_VARS['name'];
    
    // Superglobals are available in any scope and do 
    // not require 'global'.  Superglobals are available 
    // as of PHP 4.1.0
    print $_POST['name'];
}
?>

Another important feature of variable scoping is the static variable. A static variable exists only in a local function scope, but it does not lose its value when program execution leaves this scope. Consider the following example:

<?php
function Test ()
{
    $a = 0;
    echo $a;
    $a++;
}
?>

This function is quite useless since every time it is called it sets $a to 0 and prints "0". The $a++ which increments the variable serves no purpose since as soon as the function exits the $a variable disappears. To make a useful counting function which will not lose track of the current count, the $a variable is declared static:

<?php
function Test()
{
    static $a = 0;
    echo $a;
    $a++;
}
?>

Now, every time the Test() function is called it will print the value of $a and increment it.

Static variables also provide one way to deal with recursive functions. A recursive function is one which calls itself. Care must be taken when writing a recursive function because it is possible to make it recurse indefinitely. You must make sure you have an adequate way of terminating the recursion. The following simple function recursively counts to 10, using the static variable $count to know when to stop:

<?php
function Test()
{
    static $count = 0;

    $count++;
    echo $count;
    if ($count < 10) {
        Test ();
    }
    $count--;
}
?>

The Zend Engine 1, driving PHP4, implements the static and global modifier for variables in terms of references. For example, a true global variable imported inside a function scope with the global statement actually creates a reference to the global variable. This can lead to unexpected behaviour which the following example addresses:

<?php
function test_global_ref() {
    global $obj;
    $obj = &new stdclass;
}

function test_global_noref() {
    global $obj;
    $obj = new stdclass;
}

test_global_ref();
var_dump($obj);
test_global_noref();
var_dump($obj);
?>

Executing this example will result in the following output:

NULL
object(stdClass)(0) {
}

A similar behaviour applies to the static statement. References are not stored statically:

<?php
function &get_instance_ref() {
    static $obj;

    echo "Static object: ";
    var_dump($obj);
    if (!isset($obj)) {
        // Assign a reference to the static variable
        $obj = &new stdclass;
    }
    $obj->property++;
    return $obj;
}

function &get_instance_noref() {
    static $obj;

    echo "Static object: ";
    var_dump($obj);
    if (!isset($obj)) {
        // Assign the object to the static variable
        $obj = new stdclass;
    }
    $obj->property++;
    return $obj;
}

$obj1 = get_instance_ref();
$still_obj1 = get_instance_ref();
echo "\n";
$obj2 = get_instance_noref();
$still_obj2 = get_instance_noref();
?>

Executing this example will result in the following output:

Static object: NULL
Static object: NULL

Static object: NULL
Static object: object(stdClass)(1) {
  ["property"]=>
  int(1)
}

This example demonstrates that when assigning a reference to a static variable, it's not remembered when you call the &get_instance_ref() function a second time.

Variable variables

Sometimes it is convenient to be able to have variable variable names. That is, a variable name which can be set and used dynamically. A normal variable is set with a statement such as:

<?php
$a = "hello";
?>

A variable variable takes the value of a variable and treats that as the name of a variable. In the above example, hello, can be used as the name of a variable by using two dollar signs. i.e.

<?php
$$a = "world";
?>

At this point two variables have been defined and stored in the PHP symbol tree: $a with contents "hello" and $hello with contents "world". Therefore, this statement:

<?php
echo "$a ${$a}";
?>

produces the exact same output as:

<?php
echo "$a $hello";
?>

i.e. they both produce: hello world.

In order to use variable variables with arrays, you have to resolve an ambiguity problem. That is, if you write $$a[1] then the parser needs to know if you meant to use $a[1] as a variable, or if you wanted $$a as the variable and then the [1] index from that variable. The syntax for resolving this ambiguity is: ${$a[1]} for the first case and ${$a}[1] for the second.

Warning

Please note that variable variables cannot be used with PHP's Superglobal arrays. This means you cannot do things like ${$_GET}. If you are looking for a way to handle availability of superglobals and the old HTTP_*_VARS, you might want to try referencing them.

Variables from outside PHP

HTML Forms (GET and POST)

When a form is submitted to a PHP script, the information from that form is automatically made available to the script. There are many ways to access this information, for example:

Example 8-1. A simple HTML form
<form action="foo.php" method="post"> Name: <input type="text" name="username"><br> Email: <input type="text" name="email"><br> <input type="submit" name="submit" value="Submit me!"> </form>

Depending on your particular setup and personal preferences, there are many ways to access data from your HTML forms. Some examples are:

Example 8-2. Accessing data from a simple POST HTML form
<?php // Available since PHP 4.1.0 print $_POST['username']; print $_REQUEST['username']; import_request_variables('p', 'p_'); print $p_username; // Available since PHP 3. print $HTTP_POST_VARS['username']; // Available if the PHP directive register_globals = on. As of // PHP 4.2.0 the default value of register_globals = off. // Using/relying on this method is not preferred. print $username; ?>

Using a GET form is similar except you'll use the appropriate GET predefined variable instead. GET also applies to the QUERY_STRING (the information after the '?' in an URL). So, for example, http://www.example.com/test.php?id=3 contains GET data which is accessible with $_GET['id']. See also $_REQUEST and import_request_variables().

Note: Superglobal arrays, like $_POST and $_GET, became available in PHP 4.1.0

As shown, before PHP 4.2.0 the default value for register_globals was on. And, in PHP 3 it was always on. The PHP community is encouraging all to not rely on this directive as it's preferred to assume it's off and code accordingly.

Note: The magic_quotes_gpc configuration directive affects Get, Post and Cookie values. If turned on, value (It's "PHP!") will automagically become (It\'s \"PHP!\"). Escaping is needed for DB insertion. See also addslashes(), stripslashes() and magic_quotes_sybase.

PHP also understands arrays in the context of form variables (see the related faq). You may, for example, group related variables together, or use this feature to retrieve values from a multiple select input. For example, let's post a form to itself and upon submission display the data:

Example 8-3. More complex form variables
<?php if ($HTTP_POST_VARS['action'] == 'submitted') { print '<pre>'; print_r($HTTP_POST_VARS); print '<a href="'. $HTTP_SERVER_VARS['PHP_SELF'] .'">Please try again</a>'; print '</pre>'; } else { ?> <form action="<?php echo $HTTP_SERVER_VARS['PHP_SELF']; ?>" method="post"> Name: <input type="text" name="personal[name]"><br> Email: <input type="text" name="personal[email]"><br> Beer: <br> <select multiple name="beer[]"> <option value="warthog">Warthog</option> <option value="guinness">Guinness</option> <option value="stuttgarter">Stuttgarter Schwabenbräu</option> </select><br> <input type="hidden" name="action" value="submitted"> <input type="submit" name="submit" value="submit me!"> </form> <?php } ?>

In PHP 3, the array form variable usage is limited to single-dimensional arrays. In PHP 4, no such restriction applies.

IMAGE SUBMIT variable names

When submitting a form, it is possible to use an image instead of the standard submit button with a tag like:

<input type="image" src="image.gif" name="sub">

When the user clicks somewhere on the image, the accompanying form will be transmitted to the server with two additional variables, sub_x and sub_y. These contain the coordinates of the user click within the image. The experienced may note that the actual variable names sent by the browser contains a period rather than an underscore, but PHP converts the period to an underscore automatically.

HTTP Cookies

PHP transparently supports HTTP cookies as defined by Netscape's Spec. Cookies are a mechanism for storing data in the remote browser and thus tracking or identifying return users. You can set cookies using the setcookie() function. Cookies are part of the HTTP header, so the SetCookie function must be called before any output is sent to the browser. This is the same restriction as for the header() function. Cookie data is then available in the appropriate cookie data arrays, such as $_COOKIE, $HTTP_COOKIE_VARS as well as in $_REQUEST. See the setcookie() manual page for more details and examples.

If you wish to assign multiple values to a single cookie variable, you may assign it as an array. For example:

<?php
  setcookie("MyCookie[foo]", "Testing 1", time()+3600);
  setcookie("MyCookie[bar]", "Testing 2", time()+3600);
?>

That will create two seperate cookies although MyCookie will now be a single array in your script. If you want to set just one cookie with multiple values, consider using serialize() or explode() on the value first.

Note that a cookie will replace a previous cookie by the same name in your browser unless the path or domain is different. So, for a shopping cart application you may want to keep a counter and pass this along. i.e.

Example 8-4. A setcookie() example

<?php
$count++;
setcookie("count", $count, time()+3600);
setcookie("Cart[$count]", $item, time()+3600);
?>

Dots in incoming variable names

Typically, PHP does not alter the names of variables when they are passed into a script. However, it should be noted that the dot (period, full stop) is not a valid character in a PHP variable name. For the reason, look at it:
<?php $varname.ext; /* invalid variable name */ ?>
Now, what the parser sees is a variable named $varname, followed by the string concatenation operator, followed by the barestring (i.e. unquoted string which doesn't match any known key or reserved words) 'ext'. Obviously, this doesn't have the intended result.

For this reason, it is important to note that PHP will automatically replace any dots in incoming variable names with underscores.

Determining variable types

Because PHP determines the types of variables and converts them (generally) as needed, it is not always obvious what type a given variable is at any one time. PHP includes several functions which find out what type a variable is, such as: gettype(), is_array(), is_float(), is_int(), is_object(), and is_string(). See also the chapter on Types.

Chapter 9. Constants

A constant is a identifier (name) for a simple value. As the name suggests, that value cannot change during the execution of the script. (The 'magic constants' __FILE__ and __LINE__ appear to be an exception to this, but they're not actually constants.) A constant is case-sensitive by default. By convention constant identifiers are always uppercase.

The name of a constant follows the same rules as any label in PHP. A valid constant name starts with a letter or underscore, followed by any number of letters, numbers, or underscores. As a regular expression, it would be expressed thus: [a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*

Note: For our purposes here, a letter is a-z, A-Z, and the ASCII characters from 127 through 255 (0x7f-0xff).

The scope of a constant is global--you can access it anywhere in your script without regard to scope.

Syntax

You can define a constant by using the define()-function. Once a constant is defined, it can never be changed or undefined.

Only scalar data (boolean, integer, float and string) can be contained in constants.

You can get the value of a constant by simply specifying its name. Unlike with variables, you should not prepend a constant with a $. You can also use the function constant(), to read a constant's value, if you are to obtain the constant's name dynamically. Use get_defined_constants() to get a list of all defined constants.

Note: Constants and (global) variables are in a different namespace. This implies that for example TRUE and $TRUE are generally different.

If you use an undefined constant, PHP assumes that you mean the name of the constant itself. A notice will be issued when this happens. Use the defined()-function if you want to know if a constant is set.

These are the differences between constants and variables:

Constants do not have a dollar sign ($) before them;
Constants may only be defined using the define() function, not by simple assignment;
Constants may be defined and accessed anywhere without regard to variable scoping rules;
Constants may not be redefined or undefined once they have been set; and
Constants may only evaluate to scalar values.

Example 9-1. Defining Constants
<?php define("CONSTANT", "Hello world."); echo CONSTANT; // outputs "Hello world." echo Constant; // outputs "Constant" and issues a notice. ?>

Predefined constants

PHP provides a large number of predefined constants to any script which it runs. Many of these constants, however, are created by various extensions, and will only be present when those extensions are available, either via dynamic loading or because they have been compiled in.

A list of predefined constants is available in the section Predefined constants.

Chapter 10. Expressions

Expressions are the most important building stones of PHP. In PHP, almost anything you write is an expression. The simplest yet most accurate way to define an expression is "anything that has a value".

The most basic forms of expressions are constants and variables. When you type "$a = 5", you're assigning '5' into $a. '5', obviously, has the value 5, or in other words '5' is an expression with the value of 5 (in this case, '5' is an integer constant).

After this assignment, you'd expect $a's value to be 5 as well, so if you wrote $b = $a, you'd expect it to behave just as if you wrote $b = 5. In other words, $a is an expression with the value of 5 as well. If everything works right, this is exactly what will happen.

Slightly more complex examples for expressions are functions. For instance, consider the following function:

function foo ()
{
    return 5;
}

Assuming you're familiar with the concept of functions (if you're not, take a look at the chapter about functions), you'd assume that typing $c = foo() is essentially just like writing $c = 5, and you're right. Functions are expressions with the value of their return value. Since foo() returns 5, the value of the expression 'foo()' is 5. Usually functions don't just return a static value but compute something.

Of course, values in PHP don't have to be integers, and very often they aren't. PHP supports three scalar value types: integer values, floating point values and string values (scalar values are values that you can't 'break' into smaller pieces, unlike arrays, for instance). PHP also supports two composite (non-scalar) types: arrays and objects. Each of these value types can be assigned into variables or returned from functions.

So far, users of PHP/FI 2 shouldn't feel any change. However, PHP takes expressions much further, in the same way many other languages do. PHP is an expression-oriented language, in the sense that almost everything is an expression. Consider the example we've already dealt with, '$a = 5'. It's easy to see that there are two values involved here, the value of the integer constant '5', and the value of $a which is being updated to 5 as well. But the truth is that there's one additional value involved here, and that's the value of the assignment itself. The assignment itself evaluates to the assigned value, in this case 5. In practice, it means that '$a = 5', regardless of what it does, is an expression with the value 5. Thus, writing something like '$b = ($a = 5)' is like writing '$a = 5; $b = 5;' (a semicolon marks the end of a statement). Since assignments are parsed in a right to left order, you can also write '$b = $a = 5'.

Another good example of expression orientation is pre- and post-increment and decrement. Users of PHP/FI 2 and many other languages may be familiar with the notation of variable++ and variable--. These are increment and decrement operators. In PHP/FI 2, the statement '$a++' has no value (is not an expression), and thus you can't assign it or use it in any way. PHP enhances the increment/decrement capabilities by making these expressions as well, like in C. In PHP, like in C, there are two types of increment - pre-increment and post-increment. Both pre-increment and post-increment essentially increment the variable, and the effect on the variable is idential. The difference is with the value of the increment expression. Pre-increment, which is written '++$variable', evaluates to the incremented value (PHP increments the variable before reading its value, thus the name 'pre-increment'). Post-increment, which is written '$variable++' evaluates to the original value of $variable, before it was incremented (PHP increments the variable after reading its value, thus the name 'post-increment').

A very common type of expressions are comparison expressions. These expressions evaluate to either 0 or 1, meaning FALSE or TRUE (respectively). PHP supports > (bigger than), >= (bigger than or equal to), == (equal), != (not equal), < (smaller than) and <= (smaller than or equal to). These expressions are most commonly used inside conditional execution, such as if statements.

The last example of expressions we'll deal with here is combined operator-assignment expressions. You already know that if you want to increment $a by 1, you can simply write '$a++' or '++$a'. But what if you want to add more than one to it, for instance 3? You could write '$a++' multiple times, but this is obviously not a very efficient or comfortable way. A much more common practice is to write '$a = $a + 3'. '$a + 3' evaluates to the value of $a plus 3, and is assigned back into $a, which results in incrementing $a by 3. In PHP, as in several other languages like C, you can write this in a shorter way, which with time would become clearer and quicker to understand as well. Adding 3 to the current value of $a can be written '$a += 3'. This means exactly "take the value of $a, add 3 to it, and assign it back into $a". In addition to being shorter and clearer, this also results in faster execution. The value of '$a += 3', like the value of a regular assignment, is the assigned value. Notice that it is NOT 3, but the combined value of $a plus 3 (this is the value that's assigned into $a). Any two-place operator can be used in this operator-assignment mode, for example '$a -= 5' (subtract 5 from the value of $a), '$b *= 7' (multiply the value of $b by 7), etc.

There is one more expression that may seem odd if you haven't seen it in other languages, the ternary conditional operator:

$first ? $second : $third

If the value of the first subexpression is TRUE (non-zero), then the second subexpression is evaluated, and that is the result of the conditional expression. Otherwise, the third subexpression is evaluated, and that is the value.

The following example should help you understand pre- and post-increment and expressions in general a bit better:

function double($i)
{
    return $i*2;
}
$b = $a = 5;        /* assign the value five into the variable $a and $b */
$c = $a++;          /* post-increment, assign original value of $a 
                       (5) to $c */
$e = $d = ++$b;     /* pre-increment, assign the incremented value of 
                       $b (6) to $d and $e */

/* at this point, both $d and $e are equal to 6 */

$f = double($d++);  /* assign twice the value of $d <emphasis>before</emphasis> 
                       the increment, 2*6 = 12 to $f */
$g = double(++$e);  /* assign twice the value of $e <emphasis>after</emphasis>
                       the increment, 2*7 = 14 to $g */
$h = $g += 10;      /* first, $g is incremented by 10 and ends with the 
                       value of 24. the value of the assignment (24) is 
                       then assigned into $h, and $h ends with the value 
                       of 24 as well. */

In the beginning of the chapter we said that we'll be describing the various statement types, and as promised, expressions can be statements. However, not every expression is a statement. In this case, a statement has the form of 'expr' ';' that is, an expression followed by a semicolon. In '$b=$a=5;', $a=5 is a valid expression, but it's not a statement by itself. '$b=$a=5;' however is a valid statement.

One last thing worth mentioning is the truth value of expressions. In many events, mainly in conditional execution and loops, you're not interested in the specific value of the expression, but only care about whether it means TRUE or FALSE. The constants TRUE and FALSE (case-insensitive) are the two possible boolean values. When necessary, an expression is automatically converted to boolean. See the section about type-casting for details about how.

PHP provides a full and powerful implementation of expressions, and documenting it entirely goes beyond the scope of this manual. The above examples should give you a good idea about what expressions are and how you can construct useful expressions. Throughout the rest of this manual we'll write expr to indicate any valid PHP expression.

Chapter 11. Operators

Operator Precedence

The precedence of an operator specifies how "tightly" it binds two expressions together. For example, in the expression 1 + 5 * 3, the answer is 16 and not 18 because the multiplication ("*") operator has a higher precedence than the addition ("+") operator. Parentheses may be used to force precedence, if necessary. For instance: (1 + 5) * 3 evaluates to 18.

The following table lists the precedence of operators with the lowest-precedence operators listed first.

Table 11-1. Operator Precedence

Associativity	Operators
left	,
left	or
left	xor
left	and
right	print
left	= += -= *= /= .= %= &= \|= ^= ~= <<= >>=
left	? :
left	\|\|
left	&&
left	\|
left	^
left	&
non-associative	== != === !==
non-associative	< <= > >=
left	<< >>
left	+ - .
left	* / %
right	! ~ ++ -- (int) (float) (string) (array) (object) @
right	[
non-associative	new

Arithmetic Operators

Remember basic arithmetic from school? These work just like those.

Table 11-2. Arithmetic Operators

Example	Name	Result
$a + $b	Addition	Sum of $a and $b.
$a - $b	Subtraction	Difference of $a and $b.
$a * $b	Multiplication	Product of $a and $b.
$a / $b	Division	Quotient of $a and $b.
$a % $b	Modulus	Remainder of $a divided by $b.

The division operator ("/") returns a float value anytime, even if the two operands are integers (or strings that get converted to integers).

Assignment Operators

The basic assignment operator is "=". Your first inclination might be to think of this as "equal to". Don't. It really means that the the left operand gets set to the value of the expression on the rights (that is, "gets set to").

The value of an assignment expression is the value assigned. That is, the value of "$a = 3" is 3. This allows you to do some tricky things:

$a = ($b = 4) + 5; // $a is equal to 9 now, and $b has been set to 4.

In addition to the basic assignment operator, there are "combined operators" for all of the binary arithmetic and string operators that allow you to use a value in an expression and then set its value to the result of that expression. For example:

$a = 3;
$a += 5; // sets $a to 8, as if we had said: $a = $a + 5;
$b = "Hello ";
$b .= "There!"; // sets $b to "Hello There!", just like $b = $b . "There!";

Note that the assignment copies the original variable to the new one (assignment by value), so changes to one will not affect the other. This may also have relevance if you need to copy something like a large array inside a tight loop. PHP 4 supports assignment by reference, using the $var = &$othervar; syntax, but this is not possible in PHP 3. 'Assignment by reference' means that both variables end up pointing at the same data, and nothing is copied anywhere. To learn more about references, please read References explained.

Bitwise Operators

Bitwise operators allow you to turn specific bits within an integer on or off. If both the left- and right-hand parameters are strings, the bitwise operator will operate on the characters in this string.

<?php
    echo 12 ^ 9; // Outputs '5'

    echo "12" ^ "9"; // Outputs the Backspace character (ascii 8)
                     // ('1' (ascii 49)) ^ ('9' (ascii 57)) = #8

    echo "hallo" ^ "hello"; // Outputs the ascii values #0 #4 #0 #0 #0
                            // 'a' ^ 'e' = #4
?>

Table 11-3. Bitwise Operators

Example	Name	Result
$a & $b	And	Bits that are set in both $a and $b are set.
$a \| $b	Or	Bits that are set in either $a or $b are set.
$a ^ $b	Xor	Bits that are set in $a or $b but not both are set.
~ $a	Not	Bits that are set in $a are not set, and vice versa.
$a << $b	Shift left	Shift the bits of $a $b steps to the left (each step means "multiply by two")
$a >> $b	Shift right	Shift the bits of $a $b steps to the right (each step means "divide by two")

Comparison Operators

Comparison operators, as their name implies, allow you to compare two values.

Table 11-4. Comparison Operators

Example	Name	Result
$a == $b	Equal	`TRUE` if $a is equal to $b.
$a === $b	Identical	`TRUE` if $a is equal to $b, and they are of the same type. (PHP 4 only)
$a != $b	Not equal	`TRUE` if $a is not equal to $b.
$a <> $b	Not equal	`TRUE` if $a is not equal to $b.
$a !== $b	Not identical	`TRUE` if $a is not equal to $b, or they are not of the same type. (PHP 4 only)
$a < $b	Less than	`TRUE` if $a is strictly less than $b.
$a > $b	Greater than	`TRUE` if $a is strictly greater than $b.
$a <= $b	Less than or equal to	`TRUE` if $a is less than or equal to $b.
$a >= $b	Greater than or equal to	`TRUE` if $a is greater than or equal to $b.

Another conditional operator is the "?:" (or ternary) operator, which operates as in C and many other languages.

(expr1) ? (expr2) : (expr3);

This expression evaluates to expr2 if expr1 evaluates to TRUE, and expr3 if expr1 evaluates to FALSE.

Error Control Operators

PHP supports one error control operator: the at sign (@). When prepended to an expression in PHP, any error messages that might be generated by that expression will be ignored.

If the track_errors feature is enabled, any error message generated by the expression will be saved in the variable $php_errormsg. This variable will be overwritten on each error, so check early if you want to use it.

<?php
/* Intentional file error */
$my_file = @file ('non_existent_file') or
    die ("Failed opening file: error was '$php_errormsg'");

// this works for any expression, not just functions:
$value = @$cache[$key]; 
// will not issue a notice if the index $key doesn't exist.

?>

Note: The @-operator works only on expressions. A simple rule of thumb is: if you can take the value of something, you can prepend the @ operator to it. For instance, you can prepend it to variables, function and include() calls, constants, and so forth. You cannot prepend it to function or class definitions, or conditional structures such as if and foreach, and so forth.

Execution Operators

PHP supports one execution operator: backticks (``). Note that these are not single-quotes! PHP will attempt to execute the contents of the backticks as a shell command; the output will be returned (i.e., it won't simply be dumped to output; it can be assigned to a variable).

$output = `ls -al`;
echo "<pre>$output</pre>";

Note: The backtick operator is disabled when safe mode is enabled or shell_exec() is disabled.

Incrementing/Decrementing Operators

PHP supports C-style pre- and post-increment and decrement operators.

Table 11-5. Increment/decrement Operators

Example	Name	Effect
++$a	Pre-increment	Increments $a by one, then returns $a.
$a++	Post-increment	Returns $a, then increments $a by one.
--$a	Pre-decrement	Decrements $a by one, then returns $a.
$a--	Post-decrement	Returns $a, then decrements $a by one.

Here's a simple example script:

<?php
echo "<h3>Postincrement</h3>";
$a = 5;
echo "Should be 5: " . $a++ . "<br />\n";
echo "Should be 6: " . $a . "<br />\n";

echo "<h3>Preincrement</h3>";
$a = 5;
echo "Should be 6: " . ++$a . "<br />\n";
echo "Should be 6: " . $a . "<br />\n";

echo "<h3>Postdecrement</h3>";
$a = 5;
echo "Should be 5: " . $a-- . "<br />\n";
echo "Should be 4: " . $a . "<br />\n";

echo "<h3>Predecrement</h3>";
$a = 5;
echo "Should be 4: " . --$a . "<br />\n";
echo "Should be 4: " . $a . "<br />\n";
?>

Logical Operators

Table 11-6. Logical Operators

Example	Name	Result
$a and $b	And	`TRUE` if both $a and $b are `TRUE`.
$a or $b	Or	`TRUE` if either $a or $b is `TRUE`.
$a xor $b	Xor	`TRUE` if either $a or $b is `TRUE`, but not both.
! $a	Not	`TRUE` if $a is not `TRUE`.
$a && $b	And	`TRUE` if both $a and $b are `TRUE`.
$a \|\| $b	Or	`TRUE` if either $a or $b is `TRUE`.

The reason for the two different variations of "and" and "or" operators is that they operate at different precedences. (See Operator Precedence.)

String Operators

There are two string operators. The first is the concatenation operator ('.'), which returns the concatenation of its right and left arguments. The second is the concatenating assignment operator ('.='), which appends the argument on the right side to the argument on the left side. Please read Assignment Operators for more information.

$a = "Hello ";
$b = $a . "World!"; // now $b contains "Hello World!"

$a = "Hello ";
$a .= "World!";     // now $a contains "Hello World!"

Array Operators

The only array operator in PHP is the + operator. It appends the right handed array to the left handed, whereas duplicated keys are NOT overwritten.

$a = array("a" => "apple", "b" => "banana");
$b = array("a" =>"pear", "b" => "strawberry", "c" => "cherry");

$c = $a + $b;

var_dump($c);

array(3) {
  ["a"]=>
  string(5) "apple"
  ["b"]=>
  string(6) "banana"
  ["c"]=>
  string(6) "cherry"
}

Chapter 12. Control Structures

Any PHP script is built out of a series of statements. A statement can be an assignment, a function call, a loop, a conditional statement of even a statement that does nothing (an empty statement). Statements usually end with a semicolon. In addition, statements can be grouped into a statement-group by encapsulating a group of statements with curly braces. A statement-group is a statement by itself as well. The various statement types are described in this chapter.

`if`

The if construct is one of the most important features of many languages, PHP included. It allows for conditional execution of code fragments. PHP features an if structure that is similar to that of C:

if (expr)
    statement

As described in the section about expressions, expr is evaluated to its Boolean value. If expr evaluates to TRUE, PHP will execute statement, and if it evaluates to FALSE - it'll ignore it. More information about what values evaluate to FALSE can be found in the 'Converting to boolean' section.

The following example would display a is bigger than b if $a is bigger than $b:

if ($a > $b)
    print "a is bigger than b";

Often you'd want to have more than one statement to be executed conditionally. Of course, there's no need to wrap each statement with an if clause. Instead, you can group several statements into a statement group. For example, this code would display a is bigger than b if $a is bigger than $b, and would then assign the value of $a into $b:

if ($a > $b) {
    print "a is bigger than b";
    $b = $a;
}

If statements can be nested indefinitely within other if statements, which provides you with complete flexibility for conditional execution of the various parts of your program.

`else`

Often you'd want to execute a statement if a certain condition is met, and a different statement if the condition is not met. This is what else is for. else extends an if statement to execute a statement in case the expression in the if statement evaluates to FALSE. For example, the following code would display a is bigger than b if $a is bigger than $b, and a is NOT bigger than b otherwise:

if ($a > $b) {
    print "a is bigger than b";
} else {
    print "a is NOT bigger than b";
}

The else statement is only executed if the if expression evaluated to FALSE, and if there were any elseif expressions - only if they evaluated to FALSE as well (see elseif).

`elseif`

elseif, as its name suggests, is a combination of if and else. Like else, it extends an if statement to execute a different statement in case the original if expression evaluates to FALSE. However, unlike else, it will execute that alternative expression only if the elseif conditional expression evaluates to TRUE. For example, the following code would display a is bigger than b, a equal to b or a is smaller than b:

if ($a > $b) {
    print "a is bigger than b";
} elseif ($a == $b) {
    print "a is equal to b";
} else {
    print "a is smaller than b";
}

There may be several elseifs within the same if statement. The first elseif expression (if any) that evaluates to TRUE would be executed. In PHP, you can also write 'else if' (in two words) and the behavior would be identical to the one of 'elseif' (in a single word). The syntactic meaning is slightly different (if you're familiar with C, this is the same behavior) but the bottom line is that both would result in exactly the same behavior.

The elseif statement is only executed if the preceding if expression and any preceding elseif expressions evaluated to FALSE, and the current elseif expression evaluated to TRUE.

Alternative syntax for control structures

PHP offers an alternative syntax for some of its control structures; namely, if, while, for, foreach, and switch. In each case, the basic form of the alternate syntax is to change the opening brace to a colon (:) and the closing brace to endif;, endwhile;, endfor;, endforeach;, or endswitch;, respectively.

<?php if ($a == 5): ?>
A is equal to 5
<?php endif; ?>

In the above example, the HTML block "A is equal to 5" is nested within an if statement written in the alternative syntax. The HTML block would be displayed only if $a is equal to 5.

The alternative syntax applies to else and elseif as well. The following is an if structure with elseif and else in the alternative format:

if ($a == 5):
    print "a equals 5";
    print "...";
elseif ($a == 6):
    print "a equals 6";
    print "!!!";
else:
    print "a is neither 5 nor 6";
endif;

See also while, for, and if for further examples.

`while`

while loops are the simplest type of loop in PHP. They behave just like their C counterparts. The basic form of a while statement is:

while (expr) statement

The meaning of a while statement is simple. It tells PHP to execute the nested statement(s) repeatedly, as long as the while expression evaluates to TRUE. The value of the expression is checked each time at the beginning of the loop, so even if this value changes during the execution of the nested statement(s), execution will not stop until the end of the iteration (each time PHP runs the statements in the loop is one iteration). Sometimes, if the while expression evaluates to FALSE from the very beginning, the nested statement(s) won't even be run once.

Like with the if statement, you can group multiple statements within the same while loop by surrounding a group of statements with curly braces, or by using the alternate syntax:

while (expr): statement ... endwhile;

The following examples are identical, and both print numbers from 1 to 10:

/* example 1 */

$i = 1;
while ($i <= 10) {
    print $i++;  /* the printed value would be
                    $i before the increment
                    (post-increment) */
}

/* example 2 */

$i = 1;
while ($i <= 10):
    print $i;
    $i++;
endwhile;

`do..while`

do..while loops are very similar to while loops, except the truth expression is checked at the end of each iteration instead of in the beginning. The main difference from regular while loops is that the first iteration of a do..while loop is guaranteed to run (the truth expression is only checked at the end of the iteration), whereas it's may not necessarily run with a regular while loop (the truth expression is checked at the beginning of each iteration, if it evaluates to FALSE right from the beginning, the loop execution would end immediately).

There is just one syntax for do..while loops:

$i = 0;
do {
   print $i;
} while ($i>0);

The above loop would run one time exactly, since after the first iteration, when truth expression is checked, it evaluates to FALSE ($i is not bigger than 0) and the loop execution ends.

Advanced C users may be familiar with a different usage of the do..while loop, to allow stopping execution in the middle of code blocks, by encapsulating them with do..while(0), and using the break statement. The following code fragment demonstrates this:

do {
    if ($i < 5) {
        print "i is not big enough";
        break;
    }
    $i *= $factor;
    if ($i < $minimum_limit) {
        break;
    }
    print "i is ok";

     ...process i...

} while(0);

Don't worry if you don't understand this right away or at all. You can code scripts and even powerful scripts without using this 'feature'.

`for`

for loops are the most complex loops in PHP. They behave like their C counterparts. The syntax of a for loop is:

for (expr1; expr2; expr3) statement

The first expression (expr1) is evaluated (executed) once unconditionally at the beginning of the loop.

In the beginning of each iteration, expr2 is evaluated. If it evaluates to TRUE, the loop continues and the nested statement(s) are executed. If it evaluates to FALSE, the execution of the loop ends.

At the end of each iteration, expr3 is evaluated (executed).

Each of the expressions can be empty. expr2 being empty means the loop should be run indefinitely (PHP implicitly considers it as TRUE, like C). This may not be as useless as you might think, since often you'd want to end the loop using a conditional break statement instead of using the for truth expression.

Consider the following examples. All of them display numbers from 1 to 10:

/* example 1 */

for ($i = 1; $i <= 10; $i++) {
    print $i;
}

/* example 2 */

for ($i = 1;;$i++) {
    if ($i > 10) {
        break;
    }
    print $i;
}

/* example 3 */

$i = 1;
for (;;) {
    if ($i > 10) {
        break;
    }
    print $i;
    $i++;
}

/* example 4 */

for ($i = 1; $i <= 10; print $i, $i++);

Of course, the first example appears to be the nicest one (or perhaps the fourth), but you may find that being able to use empty expressions in for loops comes in handy in many occasions.

PHP also supports the alternate "colon syntax" for for loops.

for (expr1; expr2; expr3): statement; ...; endfor;

Other languages have a foreach statement to traverse an array or hash. PHP 3 has no such construct; PHP 4 does (see foreach). In PHP 3, you can combine while with the list() and each() functions to achieve the same effect. See the documentation for these functions for an example.

`foreach`

PHP 4 (not PHP 3) includes a foreach construct, much like Perl and some other languages. This simply gives an easy way to iterate over arrays. foreach works only on arrays, and will issue an error when you try to use it on a variable with a different data type or an uninitialized variables. There are two syntaxes; the second is a minor but useful extension of the first:

foreach(array_expression as $value) statement
foreach(array_expression as $key => $value) statement

The first form loops over the array given by array_expression. On each loop, the value of the current element is assigned to $value and the internal array pointer is advanced by one (so on the next loop, you'll be looking at the next element).

The second form does the same thing, except that the current element's key will be assigned to the variable $key on each loop.

Note: When foreach first starts executing, the internal array pointer is automatically reset to the first element of the array. This means that you do not need to call reset() before a foreach loop.

Note: Also note that foreach operates on a copy of the specified array, not the array itself, therefore the array pointer is not modified as with the each() construct and changes to the array element returned are not reflected in the original array.

Note: foreach does not support the ability to suppress error messages using '@'.

You may have noticed that the following are functionally identical:

reset ($arr);
while (list(, $value) = each ($arr)) {
    echo "Value: $value<br>\n";
}

foreach ($arr as $value) {
    echo "Value: $value<br>\n";
}

The following are also functionally identical:

reset ($arr);
while (list($key, $value) = each ($arr)) {
    echo "Key: $key; Value: $value<br>\n";
}

foreach ($arr as $key => $value) {
    echo "Key: $key; Value: $value<br>\n";
}

Some more examples to demonstrate usages:

/* foreach example 1: value only */

$a = array (1, 2, 3, 17);

foreach ($a as $v) {
   print "Current value of \$a: $v.\n";
}

/* foreach example 2: value (with key printed for illustration) */

$a = array (1, 2, 3, 17);

$i = 0; /* for illustrative purposes only */

foreach($a as $v) {
    print "\$a[$i] => $v.\n";
    $i++;
}

/* foreach example 3: key and value */

$a = array (
    "one" => 1,
    "two" => 2,
    "three" => 3,
    "seventeen" => 17
);

foreach($a as $k => $v) {
    print "\$a[$k] => $v.\n";
}

/* foreach example 4: multi-dimensional arrays */

$a[0][0] = "a";
$a[0][1] = "b";
$a[1][0] = "y";
$a[1][1] = "z";

foreach($a as $v1) {
    foreach ($v1 as $v2) {
        print "$v2\n";
    }
}

/* foreach example 5: dynamic arrays */

foreach(array(1, 2, 3, 4, 5) as $v) {
    print "$v\n";
}

`break`

break ends execution of the current for, foreach while, do..while or switch structure.

break accepts an optional numeric argument which tells it how many nested enclosing structures are to be broken out of.

$arr = array ('one', 'two', 'three', 'four', 'stop', 'five');
while (list (, $val) = each ($arr)) {
    if ($val == 'stop') {
        break;    /* You could also write 'break 1;' here. */
    }
    echo "$val<br>\n";
}

/* Using the optional argument. */

$i = 0;
while (++$i) {
    switch ($i) {
    case 5:
        echo "At 5<br>\n";
        break 1;  /* Exit only the switch. */
    case 10:
        echo "At 10; quitting<br>\n";
        break 2;  /* Exit the switch and the while. */
    default:
        break;
    }
}

`continue`

continue is used within looping structures to skip the rest of the current loop iteration and continue execution at the beginning of the next iteration.

continue accepts an optional numeric argument which tells it how many levels of enclosing loops it should skip to the end of.

while (list ($key, $value) = each ($arr)) {
    if (!($key % 2)) { // skip odd members
        continue;
    }
    do_something_odd ($value);
}

$i = 0;
while ($i++ < 5) {
    echo "Outer<br>\n";
    while (1) {
        echo "&nbsp;&nbsp;Middle<br>\n";
        while (1) {
            echo "&nbsp;&nbsp;Inner<br>\n";
            continue 3;
        }
        echo "This never gets output.<br>\n";
    }
    echo "Neither does this.<br>\n";
}

`switch`

The switch statement is similar to a series of IF statements on the same expression. In many occasions, you may want to compare the same variable (or expression) with many different values, and execute a different piece of code depending on which value it equals to. This is exactly what the switch statement is for.

The following two examples are two different ways to write the same thing, one using a series of if statements, and the other using the switch statement:

if ($i == 0) {
    print "i equals 0";
}
if ($i == 1) {
    print "i equals 1";
}
if ($i == 2) {
    print "i equals 2";
}

switch ($i) {
    case 0:
        print "i equals 0";
        break;
    case 1:
        print "i equals 1";
        break;
    case 2:
        print "i equals 2";
        break;
}

It is important to understand how the switch statement is executed in order to avoid mistakes. The switch statement executes line by line (actually, statement by statement). In the beginning, no code is executed. Only when a case statement is found with a value that matches the value of the switch expression does PHP begin to execute the statements. PHP continues to execute the statements until the end of the switch block, or the first time it sees a break statement. If you don't write a break statement at the end of a case's statement list, PHP will go on executing the statements of the following case. For example:

switch ($i) {
    case 0:
        print "i equals 0";
    case 1:
        print "i equals 1";
    case 2:
        print "i equals 2";
}

Here, if $i is equal to 0, PHP would execute all of the print statements! If $i is equal to 1, PHP would execute the last two print statements. You would get the expected behavior ('i equals 2' would be displayed) only if $i is equal to 2. Thus, it is important not to forget break statements (even though you may want to avoid supplying them on purpose under certain circumstances).

In a switch statement, the condition is evaluated only once and the result is compared to each case statement. In an elseif statement, the condition is evaluated again. If your condition is more complicated than a simple compare and/or is in a tight loop, a switch may be faster.

The statement list for a case can also be empty, which simply passes control into the statement list for the next case.

switch ($i) {
    case 0:
    case 1:
    case 2:
        print "i is less than 3 but not negative";
        break;
    case 3:
        print "i is 3";
}

A special case is the default case. This case matches anything that wasn't matched by the other cases, and should be the last case statement. For example:

switch ($i) {
    case 0:
        print "i equals 0";
        break;
    case 1:
        print "i equals 1";
        break;
    case 2:
        print "i equals 2";
        break;
    default:
        print "i is not equal to 0, 1 or 2";
}

The case expression may be any expression that evaluates to a simple type, that is, integer or floating-point numbers and strings. Arrays or objects cannot be used here unless they are dereferenced to a simple type.

The alternative syntax for control structures is supported with switches. For more information, see Alternative syntax for control structures .

switch ($i):
    case 0:
        print "i equals 0";
        break;
    case 1:
        print "i equals 1";
        break;
    case 2:
        print "i equals 2";
        break;
    default:
        print "i is not equal to 0, 1 or 2";
endswitch;

`declare`

The declare construct is used to set execution directives for a block of code. The syntax of declare is similar to the syntax of other flow control constructs:

declare (directive) statement

The directive section allows the behavior of the declare block to be set. Currently only one directive is recognized: the ticks directive. (See below for more information on the ticks directive)

The statement part of the declare block will be executed -- how it is executed and what side effects occur during execution may depend on the directive set in the directive block.

Ticks

A tick is an event that occurs for every N low-level statements executed by the parser within the declare block. The value for N is specified using ticks=N within the declare blocks's directive section.

The event(s) that occur on each tick are specified using the register_tick_function(). See the example below for more details. Note that more than one event can occur for each tick.

Example 12-1. Profile a section of PHP code
<?php // A function that records the time when it is called function profile ($dump = FALSE) { static $profile; // Return the times stored in profile, then erase it if ($dump) { $temp = $profile; unset ($profile); return ($temp); } $profile[] = microtime (); } // Set up a tick handler register_tick_function("profile"); // Initialize the function before the declare block profile (); // Run a block of code, throw a tick every 2nd statement declare (ticks=2) { for ($x = 1; $x < 50; ++$x) { echo similar_text (md5($x), md5($x*$x)), "<br />;"; } } // Display the data stored in the profiler print_r (profile (TRUE)); ?>
The example profiles the PHP code within the 'declare' block, recording the time at which every second low-level statement in the block was executed. This information can then be used to find the slow areas within particular segments of code. This process can be performed using other methods: using ticks is more convenient and easier to implement.

Ticks are well suited for debugging, implementing simple multitasking, backgrounded I/O and many other tasks.

return

If called from within a function, the return() statement immediately ends execution of the current function, and returns its argument as the value of the function call. return() will also end the execution of an eval() statement or script file.

If called from the global scope, then execution of the current script file is ended. If the current script file was include()ed or require()ed, then control is passed back to the calling file. Furthermore, if the current script file was include()ed, then the value given to return() will be returned as the value of the include() call. If return() is called from within the main script file, then script execution ends. If the current script file was named by the auto_prepend_file or auto_append_file configuration options in the configuration file, then that script file's execution is ended.

For more information, see Returning values.

Note: Note that since return() is a language construct and not a function, the parentheses surrounding its arguments are not required--in fact, it is more common to leave them out than to use them, although it doesn't matter one way or the other.

require()

The require() statement includes and evaluates the specific file.

require() includes and evaluates a specific file. Detailed information on how this inclusion works is described in the documentation for include().

require() and include() are identical in every way except how they handle failure. include() produces a Warning while require() results in a Fatal Error. In other words, don't hesitate to use require() if you want a missing file to halt processing of the page. include() does not behave this way, the script will continue regardless. Be sure to have an appropriate include_path setting as well.

Example 12-2. Basic require() examples
<?php require 'prepend.php'; require $somefile; require ('somefile.txt'); ?>

See the include() documentation for more examples.

Note: Prior to PHP 4.0.2, the following applies: require() will always attempt to read the target file, even if the line it's on never executes. The conditional statement won't affect require(). However, if the line on which the require() occurs is not executed, neither will any of the code in the target file be executed. Similarly, looping structures do not affect the behaviour of require(). Although the code contained in the target file is still subject to the loop, the require() itself happens only once.

Warning

Windows versions of PHP prior to PHP 4.3 do not support accessing remote files via this function, even if allow_url_fopen is enabled.

include()

The include() statement includes and evaluates the specified file.

The documentation below also applies to require(). The two constructs are identical in every way except how they handle failure. include() produces a Warning while require() results in a Fatal Error. In other words, use require() if you want a missing file to halt processing of the page. include() does not behave this way, the script will continue regardless. Be sure to have an appropriate include_path setting as well.

When a file is included, the code it contains inherits the variable scope of the line on which the include occurs. Any variables available at that line in the calling file will be available within the called file, from that point forward.

Example 12-3. Basic include() example
vars.php <?php $color = 'green'; $fruit = 'apple'; ?> test.php <?php echo "A $color $fruit"; // A include 'vars.php'; echo "A $color $fruit"; // A green apple ?>

If the include occurs inside a function within the calling file, then all of the code contained in the called file will behave as though it had been defined inside that function. So, it will follow the variable scope of that function.

Example 12-4. Including within functions
<?php function foo() { global $color; include 'vars.php'; echo "A $color $fruit"; } /* vars.php is in the scope of foo() so * * $fruit is NOT available outside of this * * scope. $color is because we declared it * * as global. */ foo(); // A green apple echo "A $color $fruit"; // A green ?>

When a file is included, parsing drops out of PHP mode and into HTML mode at the beginning of the target file, and resumes again at the end. For this reason, any code inside the target file which should be executed as PHP code must be enclosed within valid PHP start and end tags.

If "URL fopen wrappers" are enabled in PHP (which they are in the default configuration), you can specify the file to be included using an URL (via HTTP or other supported wrapper - see Appendix I for a list of protocols) instead of a local pathname. If the target server interprets the target file as PHP code, variables may be passed to the included file using an URL request string as used with HTTP GET. This is not strictly speaking the same thing as including the file and having it inherit the parent file's variable scope; the script is actually being run on the remote server and the result is then being included into the local script.

Warning

Windows versions of PHP prior to PHP 4.3 do not support accessing remote files via this function, even if allow_url_fopen is enabled.

Example 12-5. include() through HTTP
<?php /* This example assumes that www.example.com is configured to parse .php * * files and not .txt files. Also, 'Works' here means that the variables * * $foo and $bar are available within the included file. */ // Won't work; file.txt wasn't handled by www.example.com as PHP include 'http://www.example.com/file.txt?foo=1&bar=2'; // Won't work; looks for a file named 'file.php?foo=1&bar=2' on the // local filesystem. include 'file.php?foo=1&bar=2'; // Works. include 'http://www.example.com/file.php?foo=1&bar=2'; $foo = 1; $bar = 2; include 'file.txt'; // Works. include 'file.php'; // Works. ?>
See also Remote files, fopen() and file() for related information.

Because include() and require() are special language constructs, you must enclose them within a statement block if it's inside a conditional block.

Example 12-6. include() and conditional blocks
<?php // This is WRONG and will not work as desired. if ($condition) include $file; else include $other; // This is CORRECT. if ($condition) { include $file; } else { include $other; } ?>

Handling Returns: It is possible to execute a return() statement inside an included file in order to terminate processing in that file and return to the script which called it. Also, it's possible to return values from included files. You can take the value of the include call as you would a normal function.

Note: In PHP 3, the return may not appear inside a block unless it's a function block, in which case the return() applies to that function and not the whole file.

Example 12-7. include() and the return() statement
return.php <?php $var = 'PHP'; return $var; ?> noreturn.php <?php $var = 'PHP'; ?> testreturns.php <?php $foo = include 'return.php'; echo $foo; // prints 'PHP' $bar = include 'noreturn.php'; echo $bar; // prints 1 ?>

$bar is the value 1 because the include was successful. Notice the difference between the above examples. The first uses return() within the included file while the other does not. A few other ways to "include" files into variables are with fopen(), file() or by using include() along with Output Control Functions.

require_once()

The require_once() statement includes and evaluates the specified file during the execution of the script. This is a behavior similar to the require() statement, with the only difference being that if the code from a file has already been included, it will not be included again. See the documentation for require() for more information on how this statement works.

require_once() should be used in cases where the same file might be included and evaluated more than once during a particular execution of a script, and you want to be sure that it is included exactly once to avoid problems with function redefinitions, variable value reassignments, etc.

For examples on using require_once() and include_once(), look at the PEAR code included in the latest PHP source code distributions.

Note: require_once() was added in PHP 4.0.1pl2

Note: Be aware, that the behaviour of require_once() and include_once() may not be what you expect on a non case sensitive operating system (such as Windows).
Example 12-8. require_once() is case sensitive
require_once("a.php"); // this will include a.php
require_once("A.php"); // this will include a.php again on Windows!

Warning

Windows versions of PHP prior to PHP 4.3 do not support accessing remote files via this function, even if allow_url_fopen is enabled.

include_once()

The include_once() statement includes and evaluates the specified file during the execution of the script. This is a behavior similar to the include() statement, with the only difference being that if the code from a file has already been included, it will not be included again. As the name suggests, it will be included just once.

include_once() should be used in cases where the same file might be included and evaluated more than once during a particular execution of a script, and you want to be sure that it is included exactly once to avoid problems with function redefinitions, variable value reassignments, etc.

For more examples on using require_once() and include_once(), look at the PEAR code included in the latest PHP source code distributions.

Note: include_once() was added in PHP 4.0.1pl2

Note: Be aware, that the behaviour of include_once() and require_once() may not be what you expect on a non case sensitive operating system (such as Windows).
Example 12-9. include_once() is case sensitive
include_once("a.php"); // this will include a.php
include_once("A.php"); // this will include a.php again on Windows!

Warning

Windows versions of PHP prior to PHP 4.3 do not support accessing remote files via this function, even if allow_url_fopen is enabled.

Chapter 13. Functions

User-defined functions

A function may be defined using syntax such as the following:

function foo ($arg_1, $arg_2, ..., $arg_n)
{
    echo "Example function.\n";
    return $retval;
}

Any valid PHP code may appear inside a function, even other functions and class definitions.

In PHP 3, functions must be defined before they are referenced. No such requirement exists in PHP 4.

PHP does not support function overloading, nor is it possible to undefine or redefine previously-declared functions.

PHP 3 does not support variable numbers of arguments to functions, although default arguments are supported (see Default argument values for more information). PHP 4 supports both: see Variable-length argument lists and the function references for func_num_args(), func_get_arg(), and func_get_args() for more information.

Function arguments

Information may be passed to functions via the argument list, which is a comma-delimited list of variables and/or constants.

PHP supports passing arguments by value (the default), passing by reference, and default argument values. Variable-length argument lists are supported only in PHP 4 and later; see Variable-length argument lists and the function references for func_num_args(), func_get_arg(), and func_get_args() for more information. A similar effect can be achieved in PHP 3 by passing an array of arguments to a function:

function takes_array($input)
{
    echo "$input[0] + $input[1] = ", $input[0]+$input[1];
}

Making arguments be passed by reference

By default, function arguments are passed by value (so that if you change the value of the argument within the function, it does not get changed outside of the function). If you wish to allow a function to modify its arguments, you must pass them by reference.

If you want an argument to a function to always be passed by reference, you can prepend an ampersand (&) to the argument name in the function definition:

function add_some_extra(&$string)
{
    $string .= 'and something extra.';
}
$str = 'This is a string, ';
add_some_extra($str);
echo $str;    // outputs 'This is a string, and something extra.'

Default argument values

A function may define C++-style default values for scalar arguments as follows:

function makecoffee ($type = "cappuccino")
{
    return "Making a cup of $type.\n";
}
echo makecoffee ();
echo makecoffee ("espresso");

The output from the above snippet is:
Making a cup of cappuccino. Making a cup of espresso.

The default value must be a constant expression, not (for example) a variable or class member.

Note that when using default arguments, any defaults should be on the right side of any non-default arguments; otherwise, things will not work as expected. Consider the following code snippet:

function makeyogurt ($type = "acidophilus", $flavour)
{
    return "Making a bowl of $type $flavour.\n";
}
 
echo makeyogurt ("raspberry");   // won't work as expected

The output of the above example is:
Warning: Missing argument 2 in call to makeyogurt() in /usr/local/etc/httpd/htdocs/php3test/functest.html on line 41 Making a bowl of raspberry .

Now, compare the above with this:

function makeyogurt ($flavour, $type = "acidophilus")
{
    return "Making a bowl of $type $flavour.\n";
}
 
echo makeyogurt ("raspberry");   // works as expected

The output of this example is:
Making a bowl of acidophilus raspberry.

Variable-length argument lists

PHP 4 has support for variable-length argument lists in user-defined functions. This is really quite easy, using the func_num_args(), func_get_arg(), and func_get_args() functions.

No special syntax is required, and argument lists may still be explicitly provided with function definitions and will behave as normal.

Returning values

Values are returned by using the optional return statement. Any type may be returned, including lists and objects. This causes the function to end its execution immediately and pass control back to the line from which it was called. See return() for more information.

function square ($num)
{
    return $num * $num;
}
echo square (4);   // outputs '16'.

You can't return multiple values from a function, but similar results can be obtained by returning a list.

function small_numbers()
{
    return array (0, 1, 2);
}
list ($zero, $one, $two) = small_numbers();

To return a reference from a function, you have to use the reference operator & in both the function declaration and when assigning the returned value to a variable:

function &returns_reference()
{
    return $someref;
}

$newref =& returns_reference();

For more information on references, please check out References Explained.

`old_function`

The old_function statement allows you to declare a function using a syntax identical to PHP/FI2 (except you must replace 'function' with 'old_function'.

This is a deprecated feature, and should only be used by the PHP/FI2->PHP 3 convertor.

Warning

Functions declared as old_function cannot be called from PHP's internal code. Among other things, this means you can't use them in functions such as usort(), array_walk(), and register_shutdown_function(). You can get around this limitation by writing a wrapper function (in normal PHP 3 form) to call the old_function.

Variable functions

PHP supports the concept of variable functions. This means that if a variable name has parentheses appended to it, PHP will look for a function with the same name as whatever the variable evaluates to, and will attempt to execute it. Among other things, this can be used to implement callbacks, function tables, and so forth.

Variable functions won't work with language constructs such as echo(), unset(), isset(), empty(), include() and print().

Example 13-1. Variable function example
<?php function foo() { echo "In foo()<br>\n"; } function bar($arg = '') { echo "In bar(); argument was '$arg'.<br>\n"; } $func = 'foo'; $func(); $func = 'bar'; $func('test'); ?>

Chapter 14. Classes and Objects

`class`

A class is a collection of variables and functions working with these variables. A class is defined using the following syntax:

<?php
class Cart
{
    var $items;  // Items in our shopping cart
   
    // Add $num articles of $artnr to the cart
 
    function add_item ($artnr, $num)
    {
        $this->items[$artnr] += $num;
    }
   
    // Take $num articles of $artnr out of the cart
 
    function remove_item ($artnr, $num)
    {
        if ($this->items[$artnr] > $num) {
            $this->items[$artnr] -= $num;
            return true;
        } else {
            return false;
        }   
    }
}
?>

This defines a class named Cart that consists of an associative array of articles in the cart and two functions to add and remove items from this cart.

Caution

The following cautionary notes are valid for PHP 4.

The name stdClass is used interally by Zend and is reserved. You cannot have a class named stdClass in PHP.

The function names __sleep and __wakeup are magical in PHP classes. You cannot have functions with these names in any of your classes unless you want the magic functionality associated with them. See below for more information.

PHP reserves all function names starting with __ as magical. It is recommended that you do not use function names with __ in PHP unless you want some documented magic functionality.

Note: In PHP 4, only constant initializers for var variables are allowed. To initialize variables with non-constant values, you need an initialization function which is called automatically when an object is being constructed from the class. Such a function is called a constructor (see below).
<?php
/* None of these will work in PHP 4. */
class Cart
{
    var $todays_date = date("Y-m-d");
    var $name = $firstname;
    var $owner = 'Fred ' . 'Jones';
    var $items = array("VCR", "TV");
}

/* This is how it should be done. */
class Cart
{
    var $todays_date;
    var $name;
    var $owner;
    var $items;

    function Cart()
    {
        $this->todays_date = date("Y-m-d");
        $this->name = $GLOBALS['firstname'];
        /* etc. . . */
    }
}
?>

Classes are types, that is, they are blueprints for actual variables. You have to create a variable of the desired type with the new operator.

<?php
$cart = new Cart;
$cart->add_item("10", 1);

$another_cart = new Cart;
$another_cart->add_item("0815", 3);

This creates the objects $cart and $another_cart, both of the class Cart. The function add_item() of the $cart object is being called to add 1 item of article number 10 to the $cart. 3 items of article number 0815 are being added to $another_cart.

Both, $cart and $another_cart, have functions add_item(), remove_item() and a variable items. These are distinct functions and variables. You can think of the objects as something similar to directories in a filesystem. In a filesystem you can have two different files README.TXT, as long as they are in different directories. Just like with directories where you'll have to type the full pathname in order to reach each file from the toplevel directory, you have to specify the complete name of the function you want to call: In PHP terms, the toplevel directory would be the global namespace, and the pathname separator would be ->. Thus, the names $cart->items and $another_cart->items name two different variables. Note that the variable is named $cart->items, not $cart->$items, that is, a variable name in PHP has only a single dollar sign.

// correct, single $
$cart->items = array("10" => 1); 

// invalid, because $cart->$items becomes $cart->""
$cart->$items = array("10" => 1);

// correct, but may or may not be what was intended:
// $cart->$myvar becomes $cart->items
$myvar = 'items';
$cart->$myvar = array("10" => 1);

Within a class definition, you do not know under which name the object will be accessible in your program: at the time the Cart class was written, it was unknown that the object will be named $cart or $another_cart later. Thus, you cannot write $cart->items within the Cart class itself. Instead, in order to be able to access it's own functions and variables from within a class, one can use the pseudo-variable $this which can be read as 'my own' or 'current object'. Thus, '$this->items[$artnr] += $num' can be read as 'add $num to the $artnr counter of my own items array' or 'add $num to the $artnr counter of the items array within the current object'.

Note: There are some nice functions to handle classes and objects. You might want to take a look at the Class/Object Functions

`extends`

Often you need classes with similar variables and functions to another existing class. In fact, it is good practice to define a generic class which can be used in all your projects and adapt this class for the needs of each of your specific projects. To facilitate this, classes can be extensions of other classes. The extended or derived class has all variables and functions of the base class (this is called 'inheritance' despite the fact that nobody died) and what you add in the extended definition. It is not possible to substract from a class, that is, to undefine any existing functions or variables. An extended class is always dependent on a single base class, that is, multiple inheritance is not supported. Classes are extended using the keyword 'extends'.

class Named_Cart extends Cart
{
    var $owner;
  
    function set_owner ($name)
    {
        $this->owner = $name;
    }
}

This defines a class Named_Cart that has all variables and functions of Cart plus an additional variable $owner and an additional function set_owner(). You create a named cart the usual way and can now set and get the carts owner. You can still use normal cart functions on named carts:

$ncart = new Named_Cart;    // Create a named cart
$ncart->set_owner("kris");  // Name that cart
print $ncart->owner;        // print the cart owners name
$ncart->add_item("10", 1);  // (inherited functionality from cart)

This is also called a "parent-child" relationship. You create a class, parent, and use extends to create a new class based on the parent class: the child class. You can even use this new child class and create another class based on this child class.

Note: Classes must be defined before they are used! If you want the class Named_Cart to extend the class Cart, you will have to define the class Cart first. If you want to create another class called Yellow_named_cart based on the class Named_Cart you have to define Named_Cart first. To make it short: the order in which the classes are defined is important.

`Constructors`

Caution

In PHP 3 and PHP 4 constructors behave differently. The PHP 4 semantics are strongly preferred.

Constructors are functions in a class that are automatically called when you create a new instance of a class with new. In PHP 3, a function becomes a constructor when it has the same name as the class. In PHP 4, a function becomes a constructor, when it has the same name as the class it is defined in - the difference is subtle, but crucial (see below).

// Works in PHP 3 and PHP 4.
class Auto_Cart extends Cart
{
    function Auto_Cart()
    {
        $this->add_item ("10", 1);
    }
}

This defines a class Auto_Cart that is a Cart plus a constructor which initializes the cart with one item of article number "10" each time a new Auto_Cart is being made with "new". Constructors can take arguments and these arguments can be optional, which makes them much more useful. To be able to still use the class without parameters, all parameters to constructors should be made optional by providing default values.

// Works in PHP 3 and PHP 4.
class Constructor_Cart extends Cart
{
    function Constructor_Cart($item = "10", $num = 1)
    {
        $this->add_item ($item, $num);
    }
}
 
// Shop the same old boring stuff.
 
$default_cart = new Constructor_Cart;
 
// Shop for real...
 
$different_cart = new Constructor_Cart("20", 17);

You also can use the @ operator to mute errors occuring in the constructor, e.g. @new.

Caution

In PHP 3, derived classes and constructors have a number of limitations. The following examples should be read carefully to understand these limitations.

class A
{
    function A()
    {
      echo "I am the constructor of A.<br>\n";
    }
}

class B extends A
{
    function C()
    {
        echo "I am a regular function.<br>\n";
    }
}

// no constructor is being called in PHP 3.
$b = new B;

In PHP 3, no constructor is being called in the above example. The rule in PHP 3 is: 'A constructor is a function of the same name as the class.'. The name of the class is B, and there is no function called B() in class B. Nothing happens.

This is fixed in PHP 4 by introducing another rule: If a class has no constructor, the constructor of the base class is being called, if it exists. The above example would have printed 'I am the constructor of A.<br>' in PHP 4.

class A
{
    function A()
    {
        echo "I am the constructor of A.<br>\n";
    }

    function B()
    {
        echo "I am a regular function named B in class A.<br>\n";
        echo "I am not a constructor in A.<br>\n";
    }
}

class B extends A
{
    function C()
    {
        echo "I am a regular function.<br>\n";
    }
}

// This will call B() as a constructor.
$b = new B;

In PHP 3, the function B() in class A will suddenly become a constructor in class B, although it was never intended to be. The rule in PHP 3 is: 'A constructor is a function of the same name as the class.'. PHP 3 does not care if the function is being defined in class B, or if it has been inherited.

This is fixed in PHP 4 by modifying the rule to: 'A constructor is a function of the same name as the class it is being defined in.'. Thus in PHP 4, the class B would have no constructor function of its own and the constructor of the base class would have been called, printing 'I am the constructor of A.<br>'.

Caution

Neither PHP 3 nor PHP 4 call constructors of the base class automatically from a constructor of a derived class. It is your responsibility to propagate the call to constructors upstream where appropriate.

Note: There are no destructors in PHP 3 or PHP 4. You may use register_shutdown_function() instead to simulate most effects of destructors.

Destructors are functions that are called automatically when an object is destroyed, either with unset() or by simply going out of scope. There are no destructors in PHP.

`::`

Caution

The following is valid for PHP 4 only.

Sometimes it is useful to refer to functions and variables in base classes or to refer to functions in classes that have not yet any instances. The :: operator is being used for this.

class A
{
    function example()
    {
        echo "I am the original function A::example().<br>\n";
    }
}

class B extends A
{
    function example()
    {
        echo "I am the redefined function B::example().<br>\n";
        A::example();
    }
}

// there is no object of class A.
// this will print
//   I am the original function A::example().<br>
A::example();

// create an object of class B.
$b = new B;

// this will print 
//   I am the redefined function B::example().<br>
//   I am the original function A::example().<br>
$b->example();

The above example calls the function example() in class A, but there is no object of class A, so that we cannot write $a->example() or similar. Instead we call example() as a 'class function', that is, as a function of the class itself, not any object of that class.

There are class functions, but there are no class variables. In fact, there is no object at all at the time of the call. Thus, a class function may not use any object variables (but it can use local and global variables), and it may no use $this at all.

In the above example, class B redefines the function example(). The original definition in class A is shadowed and no longer available, unless you are refering specifically to the implementation of example() in class A using the ::-operator. Write A::example() to do this (in fact, you should be writing parent::example(), as shown in the next section).

In this context, there is a current object and it may have object variables. Thus, when used from WITHIN an object function, you may use $this and object variables.

`parent`

You may find yourself writing code that refers to variables and functions in base classes. This is particularly true if your derived class is a refinement or specialisation of code in your base class.

Instead of using the literal name of the base class in your code, you should be using the special name parent, which refers to the name of your base class as given in the extends declaration of your class. By doing this, you avoid using the name of your base class in more than one place. Should your inheritance tree change during implementation, the change is easily made by simply changing the extends declaration of your class.

class A
{
    function example()
    {
        echo "I am A::example() and provide basic functionality.<br>\n";
    }
}

class B extends A
{
    function example()
    {
        echo "I am B::example() and provide additional functionality.<br>\n";
        parent::example();
    }
}

$b = new B;

// This will call B::example(), which will in turn call A::example().
$b->example();

Serializing objects - objects in sessions

Note: In PHP 3, objects will lose their class association throughout the process of serialization and unserialization. The resulting variable is of type object, but has no class and no methods, thus it is pretty useless (it has become just like an array with a funny syntax).

Caution

The following information is valid for PHP 4 only.

serialize() returns a string containing a byte-stream representation of any value that can be stored in PHP. unserialize() can use this string to recreate the original variable values. Using serialize to save an object will save all variables in an object. The functions in an object will not be saved, only the name of the class.

In order to be able to unserialize() an object, the class of that object needs to be defined. That is, if you have an object $a of class A on page1.php and serialize this, you'll get a string that refers to class A and contains all values of variabled contained in $a. If you want to be able to unserialize this on page2.php, recreating $a of class A, the definition of class A must be present in page2.php. This can be done for example by storing the class defintion of class A in an include file and including this file in both page1.php and page2.php.

classa.inc:
  class A 
  {
      var $one = 1;
    
      function show_one()
      {
          echo $this->one;
      }
  }
  
page1.php:
  include("classa.inc");
  
  $a = new A;
  $s = serialize($a);
  // store $s somewhere where page2.php can find it.
  $fp = fopen("store", "w");
  fputs($fp, $s);
  fclose($fp);

page2.php:
  // this is needed for the unserialize to work properly.
  include("classa.inc");

  $s = implode("", @file("store"));
  $a = unserialize($s);

  // now use the function show_one() of the $a object.  
  $a->show_one();

If you are using sessions and use session_register() to register objects, these objects are serialized automatically at the end of each PHP page, and are unserialized automatically on each of the following pages. This basically means that these objects can show up on any of your pages once they become part of your session.

It is strongly recommended that you include the class definitions of all such registered objects on all of your pages, even if you do not actually use these classes on all of your pages. If you don't and an object is being unserialized without its class definition being present, it will lose its class association and become an object of class stdClass without any functions available at all, that is, it will become quite useless.

So if in the example above $a became part of a session by running session_register("a"), you should include the file classa.inc on all of your pages, not only page1.php and page2.php.

The magic functions `sleep` and `wakeup`

serialize() checks if your class has a function with the magic name __sleep. If so, that function is being run prior to any serialization. It can clean up the object and is supposed to return an array with the names of all variables of that object that should be serialized.

The intended use of __sleep is to close any database connections that object may have, committing pending data or perform similar cleanup tasks. Also, the function is useful if you have very large objects which need not be saved completely.

Conversely, unserialize() checks for the presence of a function with the magic name __wakeup. If present, this function can reconstruct any resources that object may have.

The intended use of __wakeup is to reestablish any database connections that may have been lost during serialization and perform other reinitialization tasks.

References inside the constructor

Creating references within the constructor can lead to confusing results. This tutorial-like section helps you to avoid problems.

class Foo
{
    function Foo($name)
    {
        // create a reference inside the global array $globalref
        global $globalref;
        $globalref[] = &$this;
        // set name to passed value
        $this->setName($name);
        // and put it out
        $this->echoName();
    }

    function echoName()
    {
        echo "<br>",$this->name;
    }
	
    function setName($name)
    {
        $this->name = $name;
    }
}

Let us check out if there is a difference between $bar1 which has been created using the copy = operator and $bar2 which has been created using the reference =& operator...

$bar1 = new Foo('set in constructor');
$bar1->echoName();
$globalref[0]->echoName();

/* output:
set in constructor
set in constructor
set in constructor */

$bar2 =& new Foo('set in constructor');
$bar2->echoName();
$globalref[1]->echoName();

/* output:
set in constructor
set in constructor
set in constructor */

Apparently there is no difference, but in fact there is a very significant one: $bar1 and $globalref[0] are _NOT_ referenced, they are NOT the same variable. This is because "new" does not return a reference by default, instead it returns a copy.

Note: There is no performance loss (since PHP 4 and up use reference counting) returning copies instead of references. On the contrary it is most often better to simply work with copies instead of references, because creating references takes some time where creating copies virtually takes no time (unless none of them is a large array or object and one of them gets changed and the other(s) one(s) subsequently, then it would be wise to use references to change them all concurrently).

To prove what is written above let us watch the code below.

// now we will change the name. what do you expect?
// you could expect that both $bar1 and $globalref[0] change their names...
$bar1->setName('set from outside');

// as mentioned before this is not the case.
$bar1->echoName();
$globalref[0]->echoName();

/* output:
set from outside
set in constructor */

// let us see what is different with $bar2 and $globalref[1]
$bar2->setName('set from outside');

// luckily they are not only equal, they are the same variable
// thus $bar2->name and $globalref[1]->name are the same too
$bar2->echoName();
$globalref[1]->echoName();

/* output:
set from outside
set from outside */

Another final example, try to understand it.

class A
{
    function A($i)
    {
        $this->value = $i;
        // try to figure out why we do not need a reference here
        $this->b = new B($this);
    }

    function createRef()
    {
        $this->c = new B($this);
    }

    function echoValue()
    {
        echo "<br>","class ",get_class($this),': ',$this->value;
    }
}


class B
{
    function B(&$a)
    {
        $this->a = &$a;
    }

    function echoValue()
    {
        echo "<br>","class ",get_class($this),': ',$this->a->value;
    }
}

// try to undestand why using a simple copy here would yield
// in an undesired result in the *-marked line
$a =& new A(10);
$a->createRef();

$a->echoValue();
$a->b->echoValue();
$a->c->echoValue();

$a->value = 11;

$a->echoValue();
$a->b->echoValue(); // *
$a->c->echoValue();

/*
output:
class A: 10
class B: 10
class B: 10
class A: 11
class B: 11
class B: 11
*/

Chapter 15. References Explained

What References Are

References in PHP are a means to access the same variable content by different names. They are not like C pointers, they are symbol table aliases. Note that in PHP, variable name and variable content are different, so the same content can have different names. The most close analogy is with Unix filenames and files - variable names are directory entries, while variable contents is the file itself. References can be thought of as hardlinking in Unix filesystem.

What References Do

PHP references allow you to make two variables to refer to the same content. Meaning, when you do:

$a =& $b

it means that $a and $b point to the same variable.

Note: $a and $b are completely equal here, that's not $a is pointing to $b or vice versa, that's $a and $b pointing to the same place.

The same syntax can be used with functions, that return references, and with new operator (in PHP 4.0.4 and later):

$bar =& new fooclass();
$foo =& find_var ($bar);

Note: Not using the & operator causes a copy of the object to be made. If you use $this in the class it will operate on the current instance of the class. The assignment without & will copy the instance (i.e. the object) and $this will operate on the copy, which is not always what is desired. Usually you want to have a single instance to work with, due to performance and memory consumption issues.
While you can use the @ operator to mute any errors in the constructor when using it as @new, this does not work when using the &new statement. This is a limitation of the Zend Engine and will therefore result in a parser error.

The second thing references do is to pass variables by-reference. This is done by making a local variable in a function and a variable in the calling scope reference to the same content. Example:

function foo (&$var)
{
    $var++;
}

$a=5;
foo ($a);

will make $a to be 6. This happens because in the function foo the variable $var refers to the same content as $a. See also more detailed explanations about passing by reference.

The third thing reference can do is return by reference.

What References Are Not

As said before, references aren't pointers. That means, the following construct won't do what you expect:

function foo (&$var)
{
    $var =& $GLOBALS["baz"];
}
foo($bar);

What happens is that $var in foo will be bound with $bar in caller, but then it will be re-bound with $GLOBALS["baz"]. There's no way to bind $bar in the calling scope to something else using the reference mechanism, since $bar is not available in the function foo (it is represented by $var, but $var has only variable contents and not name-to-value binding in the calling symbol table).

Passing by Reference

You can pass variable to function by reference, so that function could modify its arguments. The syntax is as follows:

function foo (&$var)
{
    $var++;
}

$a=5;
foo ($a);
// $a is 6 here

Note that there's no reference sign on function call - only on function definition. Function definition alone is enough to correctly pass the argument by reference.

Following things can be passed by reference:

Variable, i.e. foo($a)
New statement, i.e. foo(new foobar())
Reference, returned from a function, i.e.:
function &bar() { $a = 5; return $a; } foo(bar());
See also explanations about returning by reference.

Any other expression should not be passed by reference, as the result is undefined. For example, the following examples of passing by reference are invalid:

function bar() // Note the missing &
{
    $a = 5;
    return $a;
}
foo(bar());

foo($a = 5) // Expression, not variable
foo(5) // Constant, not variable

These requirements are for PHP 4.0.4 and later.

Returning References

Returning by-reference is useful when you want to use a function to find which variable a reference should be bound to. When returning references, use this syntax:

function &find_var ($param)
{
    ...code...
    return $found_var;
}

$foo =& find_var ($bar);
$foo->x = 2;

In this example, the property of the object returned by the find_var function would be set, not the copy, as it would be without using reference syntax.

Note: Unlike parameter passing, here you have to use & in both places - to indicate that you return by-reference, not a copy as usual, and to indicate that reference binding, rather than usual assignment, should be done for $foo.

Unsetting References

When you unset the reference, you just break the binding between variable name and variable content. This does not mean that variable content will be destroyed. For example:

$a = 1;
$b =& $a;
unset ($a);

won't unset $b, just $a.

Again, it might be useful to think about this as analogous to Unix unlink call.

Spotting References

Many syntax constructs in PHP are implemented via referencing mechanisms, so everything told above about reference binding also apply to these constructs. Some constructs, like passing and returning by-reference, are mentioned above. Other constructs that use references are:

`global` References

When you declare variable as global $var you are in fact creating reference to a global variable. That means, this is the same as:

$var =& $GLOBALS["var"];

That means, for example, that unsetting $var won't unset global variable.

`$this`

In an object method, $this is always reference to the caller object.

III. Features

Table of Contents
16. HTTP authentication with PHP
17. Cookies
18. Handling file uploads
19. Using remote files
20. Connection handling
21. Persistent Database Connections
22. Safe Mode
23. Using PHP from the command line

Chapter 16. HTTP authentication with PHP

The HTTP Authentication hooks in PHP are only available when it is running as an Apache module and is hence not available in the CGI version. In an Apache module PHP script, it is possible to use the header() function to send an "Authentication Required" message to the client browser causing it to pop up a Username/Password input window. Once the user has filled in a username and a password, the URL containing the PHP script will be called again with the predefined variables PHP_AUTH_USER, PHP_AUTH_PW, and PHP_AUTH_TYPE set to the user name, password and authentication type respectively. These predefined variables are found in the $_SERVER and $HTTP_SERVER_VARS arrays. Only "Basic" authentication is supported. See the header() function for more information.

PHP Version Note: Autoglobals, such as $_SERVER, became available in PHP version 4.1.0. $HTTP_SERVER_VARS has been available since PHP 3.

An example script fragment which would force client authentication on a page is as follows:

Example 16-1. HTTP Authentication example
<?php if (!isset($_SERVER['PHP_AUTH_USER'])) { header('WWW-Authenticate: Basic realm="My Realm"'); header('HTTP/1.0 401 Unauthorized'); echo 'Text to send if user hits Cancel button'; exit; } else { echo "<p>Hello {$_SERVER['PHP_AUTH_USER']}.</p>"; echo "<p>You entered {$_SERVER['PHP_AUTH_PW']} as your password.</p>"; } ?>

Compatibility Note: Please be careful when coding the HTTP header lines. In order to guarantee maximum compatibility with all clients, the keyword "Basic" should be written with an uppercase "B", the realm string must be enclosed in double (not single) quotes, and exactly one space should precede the 401 code in the HTTP/1.0 401 header line.

Instead of simply printing out PHP_AUTH_USER and PHP_AUTH_PW, as done in the above example, you may want to check the username and password for validity. Perhaps by sending a query to a database, or by looking up the user in a dbm file.

Watch out for buggy Internet Explorer browsers out there. They seem very picky about the order of the headers. Sending the WWW-Authenticate header before the HTTP/1.0 401 header seems to do the trick for now.

In order to prevent someone from writing a script which reveals the password for a page that was authenticated through a traditional external mechanism, the PHP_AUTH variables will not be set if external authentication is enabled for that particular page. In this case, REMOTE_USER can be used to identify the externally-authenticated user. So, $_SERVER['REMOTE_USER'].

Configuration Note: PHP uses the presence of an AuthType directive to determine whether external authentication is in effect. Remember to avoid this directive for the context where you want to use PHP authentication (otherwise each authentication attempt will fail).

Note, however, that the above does not prevent someone who controls a non-authenticated URL from stealing passwords from authenticated URLs on the same server.

Both Netscape Navigator and Internet Explorer will clear the local browser window's authentication cache for the realm upon receiving a server response of 401. This can effectively "log out" a user, forcing them to re-enter their username and password. Some people use this to "time out" logins, or provide a "log-out" button.

Example 16-2. HTTP Authentication example forcing a new name/password
<?php function authenticate() { header('WWW-Authenticate: Basic realm="Test Authentication System"'); header('HTTP/1.0 401 Unauthorized'); echo "You must enter a valid login ID and password to access this resource\n"; exit; } if (!isset($_SERVER['PHP_AUTH_USER']) || ($_POST['SeenBefore'] == 1 && $_POST['OldAuth'] == $_SERVER['PHP_AUTH_USER'])) { authenticate(); } else { echo "<p>Welcome: {$_SERVER['PHP_AUTH_USER']}<br>"; echo "Old: {$_REQUEST['OldAuth']}"; echo "<form action='{$_SERVER['PHP_SELF']}' METHOD='POST'>\n"; echo "<input type='hidden' name='SeenBefore' value='1'>\n"; echo "<input type='hidden' name='OldAuth' value='{$_SERVER['PHP_AUTH_USER']}'>\n"; echo "<input type='submit' value='Re Authenticate'>\n"; echo "</form></p>\n"; } ?>

This behavior is not required by the HTTP Basic authentication standard, so you should never depend on this. Testing with Lynx has shown that Lynx does not clear the authentication credentials with a 401 server response, so pressing back and then forward again will open the resource as long as the credential requirements haven't changed. The user can press the '_' key to clear their authentication information, however.

Also note that this does not work using Microsoft's IIS server and the CGI version of PHP due to a limitation of IIS.

Note: If safe mode is enabled, the uid of the script is added to the realm part of the WWW-Authenticate header.

Chapter 17. Cookies

PHP transparently supports HTTP cookies. Cookies are a mechanism for storing data in the remote browser and thus tracking or identifying return users. You can set cookies using the setcookie() function. Cookies are part of the HTTP header, so setcookie() must be called before any output is sent to the browser. This is the same limitation that header() has. You can use the output buffering functions to delay the script output until you have decided whether or not to set any cookies or send any headers.

Any cookies sent to you from the client will automatically be turned into a PHP variable just like GET and POST method data, depending on the register_globals and variables_order configuration variables. If you wish to assign multiple values to a single cookie, just add [] to the cookie name.

In PHP 4.1.0 and later, the $_COOKIE auto-global array will always be set with any cookies sent from the client. $HTTP_COOKIE_VARS is also set in earlier versions of PHP when the track_vars configuration variable is set.

For more details, including notes on browser bugs, see the setcookie() function.

Chapter 18. Handling file uploads

POST method uploads

PHP is capable of receiving file uploads from any RFC-1867 compliant browser (which includes Netscape Navigator 3 or later, Microsoft Internet Explorer 3 with a patch from Microsoft, or later without a patch). This feature lets people upload both text and binary files. With PHP's authentication and file manipulation functions, you have full control over who is allowed to upload and what is to be done with the file once it has been uploaded.

Related Configurations Note: See also the file_uploads, upload_max_filesize, upload_tmp_dir, and post_max_size directives in php.ini

Note that PHP also supports PUT-method file uploads as used by Netscape Composer and W3C's Amaya clients. See the PUT Method Support for more details.

A file upload screen can be built by creating a special form which looks something like this:
Example 18-1. File Upload Form
<form enctype="multipart/form-data" action="_URL_" method="post"> <input type="hidden" name="MAX_FILE_SIZE" value="1000"> Send this file: <input name="userfile" type="file"> <input type="submit" value="Send File"> </form>
The _URL_ should point to a PHP file. The MAX_FILE_SIZE hidden field must precede the file input field and its value is the maximum filesize accepted. The value is in bytes.

Warning

The MAX_FILE_SIZE is advisory to the browser. It is easy to circumvent this maximum. So don't count on it that the browser obeys your wish! The PHP-settings for maximum-size, however, cannot be fooled.

The Variables defined for uploaded files differs depending on the PHP version and configuration. The autoglobal $_FILES exists as of PHP 4.1.0 The $HTTP_POST_FILES array has existed since PHP 4.0.0. These arrays will contain all your uploaded file information. Using $_FILES is preferred. If the PHP directive register_globals is on, related variable names will also exist. register_globals defaults to off as of PHP 4.2.0.

The contents of $_FILES from our example script is as follows. Note that this assumes the use of the file upload name userfile, as used in the example script above.

$_FILES['userfile']['name']: The original name of the file on the client machine.
$_FILES['userfile']['type']: The mime type of the file, if the browser provided this information. An example would be "image/gif".
$_FILES['userfile']['size']: The size, in bytes, of the uploaded file.
$_FILES['userfile']['tmp_name']: The temporary filename of the file in which the uploaded file was stored on the server.
$_FILES['userfile']['error']: The error code associated with this file upload. ['error'] was added in PHP 4.2.0

Note: In PHP versions prior 4.1.0 this was named $HTTP_POST_FILES and it's not an autoglobal variable like $_FILES is. PHP 3 does not support $HTTP_POST_FILES.

When register_globals is turned on in php.ini, additional variables are available. For example, $userfile_name will equal $_FILES['userfile']['name'], $userfile_type will equal $_FILES['userfile']['type'], etc. Keep in mind that as of PHP 4.2.0, register_globals defaults to off. It's preferred to not rely on this directive.

Files will by default be stored in the server's default temporary directory, unless another location has been given with the upload_tmp_dir directive in php.ini. The server's default directory can be changed by setting the environment variable TMPDIR in the environment in which PHP runs. Setting it using putenv() from within a PHP script will not work. This environment variable can also be used to make sure that other operations are working on uploaded files, as well.
Example 18-2. Validating file uploads
The following examples are for versions of PHP 4 greater than 4.0.2. See the function entries for is_uploaded_file() and move_uploaded_file().
<?php // In PHP earlier then 4.1.0, $HTTP_POST_FILES should be used instead of $_FILES. if (is_uploaded_file($_FILES['userfile']['tmp_name'])) { copy($_FILES['userfile']['tmp_name'], "/place/to/put/uploaded/file"); } else { echo "Possible file upload attack. Filename: " . $_FILES['userfile']['name']; } /* ...or... */ move_uploaded_file($_FILES['userfile']['tmp_name'], "/place/to/put/uploaded/file"); ?>

The PHP script which receives the uploaded file should implement whatever logic is necessary for determining what should be done with the uploaded file. You can for example use the $_FILES['userfile']['size'] variable to throw away any files that are either too small or too big. You could use the $_FILES['userfile']['type'] variable to throw away any files that didn't match a certain type criteria. As of PHP 4.2.0, you could use $_FILES['userfile']['error'] and plan your logic according to the error codes. Whatever the logic, you should either delete the file from the temporary directory or move it elsewhere.

The file will be deleted from the temporary directory at the end of the request if it has not been moved away or renamed.

Error Messages Explained

Since PHP 4.2.0, PHP returns an appropriate error code along with the file array. The error code can be found in the ['error'] segment of the file array that is created during the file upload by PHP. In otherwords, the error might be found in $_FILES['userfile']['error'].

UPLOAD_ERR_OK: Value: 0; There is no error, the file uploaded with success.
UPLOAD_ERR_INI_SIZE: Value: 1; The uploaded file exceeds the upload_max_filesize directive in php.ini.
UPLOAD_ERR_FORM_SIZE: Value: 2; The uploaded file exceeds the MAX_FILE_SIZE directive that was specified in the html form.
UPLOAD_ERR_PARTIAL: Value: 3; The uploaded file was only partially uploaded.
UPLOAD_ERR_NO_FILE: Value: 4; No file was uploaded.

Note: These became PHP constants in PHP 4.3.0

Common Pitfalls

The MAX_FILE_SIZE item cannot specify a file size greater than the file size that has been set in the upload_max_filesize ini-setting. The default is 2 Megabytes.

If memory limit is enabled, larger memory_limit may be needed. Make sure to set memory_limit large enough.

If max_execution_time is set too small, script execution may be exceeded the value. Make sure to set max_execution_time large enough.

If post_max_size set too small, large files cannot be uploaded. Make sure to set post_max_size large enough.

Not validating which file you operate on may mean that users can access sensitive information in other directories.

Please note that the CERN httpd seems to strip off everything starting at the first whitespace in the content-type mime header it gets from the client. As long as this is the case, CERN httpd will not support the file upload feature.

Due to the large amount of directory listing styles we cannot guarantee that files with exotic names (like containing spaces) are handled properly.

Uploading multiple files

Multiple files can be uploaded using different name for input.

It is also possible to upload multiple files simultaneously and have the information organized automatically in arrays for you. To do so, you need to use the same array submission syntax in the HTML form as you do with multiple selects and checkboxes:

Note: Support for multiple file uploads was added in version 3.0.10.

Example 18-3. Uploading multiple files
<form action="file-upload.php" method="post" enctype="multipart/form-data"> Send these files:<br> <input name="userfile[]" type="file"><br> <input name="userfile[]" type="file"><br> <input type="submit" value="Send files"> </form>

When the above form is submitted, the arrays $_FILES['userfile'], $_FILES['userfile']['name'], and $_FILES['userfile']['size'] will be initialized (as well as in $HTTP_POST_FILES for PHP version prior 4.1.0). When register_globals is on, globals for uploaded files are also initialized). Each of these will be a numerically indexed array of the appropriate values for the submitted files.

For instance, assume that the filenames /home/test/review.html and /home/test/xwp.out are submitted. In this case, $_FILES['userfile']['name'][0] would contain the value review.html, and $_FILES['userfile']['name'][1] would contain the value xwp.out. Similarly, $_FILES['userfile']['size'][0] would contain review.html's filesize, and so forth.

$_FILES['userfile']['name'][0], $_FILES['userfile']['tmp_name'][0], $_FILES['userfile']['size'][0], and $_FILES['userfile']['type'][0] are also set.

PUT method support

PHP provides support for the HTTP PUT method used by clients such as Netscape Composer and W3C Amaya. PUT requests are much simpler than a file upload and they look something like this:

PUT /path/filename.html HTTP/1.1

This would normally mean that the remote client would like to save the content that follows as: /path/filename.html in your web tree. It is obviously not a good idea for Apache or PHP to automatically let everybody overwrite any files in your web tree. So, to handle such a request you have to first tell your web server that you want a certain PHP script to handle the request. In Apache you do this with the Script directive. It can be placed almost anywhere in your Apache configuration file. A common place is inside a <Directory> block or perhaps inside a <Virtualhost> block. A line like this would do the trick:

Script PUT /put.php

This tells Apache to send all PUT requests for URIs that match the context in which you put this line to the put.php script. This assumes, of course, that you have PHP enabled for the .php extension and PHP is active.

Inside your put.php file you would then do something like this:

<?php copy($PHP_UPLOADED_FILE_NAME,$DOCUMENT_ROOT.$REQUEST_URI); ?>

This would copy the file to the location requested by the remote client. You would probably want to perform some checks and/or authenticate the user before performing this file copy. The only trick here is that when PHP sees a PUT-method request it stores the uploaded file in a temporary file just like those handled but the POST-method. When the request ends, this temporary file is deleted. So, your PUT handling PHP script has to copy that file somewhere. The filename of this temporary file is in the $PHP_PUT_FILENAME variable, and you can see the suggested destination filename in the $REQUEST_URI (may vary on non-Apache web servers). This destination filename is the one that the remote client specified. You do not have to listen to this client. You could, for example, copy all uploaded files to a special uploads directory.

Chapter 19. Using remote files

As long as allow_url_fopen is enabled in php.ini, you can use HTTP and FTP URLs with most of the functions that take a filename as a parameter. In addition, URLs can be used with the include(), include_once(), require() and require_once() statements. See Appendix I for more information about the protocols supported by PHP.

Note: In PHP 4.0.3 and older, in order to use URL wrappers, you were required to configure PHP using the configure option --enable-url-fopen-wrapper.

Note: The Windows versions of PHP earlier than PHP 4.3 did not support remote file accessing for the following functions: include(), include_once(), require(), require_once(), and the imagecreatefromXXX functions in the Reference XLI, Image functions extension.

For example, you can use this to open a file on a remote web server, parse the output for the data you want, and then use that data in a database query, or simply to output it in a style matching the rest of your website.

Example 19-1. Getting the title of a remote page
<?php $file = fopen ("http://www.example.com/", "r"); if (!$file) { echo "<p>Unable to open remote file.\n"; exit; } while (!feof ($file)) { $line = fgets ($file, 1024); /* This only works if the title and its tags are on one line */ if (eregi ("<title>(.*)</title>", $line, $out)) { $title = $out[1]; break; } } fclose($file); ?>

You can also write to files on an FTP server (provided that you have connected as a user with the correct access rights). You can only create new files using this method; if you try to overwrite a file that already exists, the fopen() call will fail.

To connect as a user other than 'anonymous', you need to specify the username (and possibly password) within the URL, such as 'ftp://user:password@ftp.example.com/path/to/file'. (You can use the same sort of syntax to access files via HTTP when they require Basic authentication.)

Example 19-2. Storing data on a remote server
<?php $file = fopen ("ftp://ftp.example.com/incoming/outputfile", "w"); if (!$file) { echo "<p>Unable to open remote file for writing.\n"; exit; } /* Write the data here. */ fputs ($file, $_SERVER['HTTP_USER_AGENT'] . "\n"); fclose ($file); ?>

Note: You might get the idea from the example above that you can use this technique to write to a remote log file. Unfortunately that would not work because the fopen() call will fail if the remote file already exists. To do distributed logging like that, you should take a look at syslog().

Chapter 20. Connection handling

Note: The following applies to 3.0.7 and later.

Internally in PHP a connection status is maintained. There are 3 possible states:

0 - NORMAL
1 - ABORTED
2 - TIMEOUT

When a PHP script is running normally the NORMAL state, is active. If the remote client disconnects the ABORTED state flag is turned on. A remote client disconnect is usually caused by the user hitting his STOP button. If the PHP-imposed time limit (see set_time_limit()) is hit, the TIMEOUT state flag is turned on.

You can decide whether or not you want a client disconnect to cause your script to be aborted. Sometimes it is handy to always have your scripts run to completion even if there is no remote browser receiving the output. The default behaviour is however for your script to be aborted when the remote client disconnects. This behaviour can be set via the ignore_user_abort php.ini directive as well as through the corresponding "php_value ignore_user_abort" Apache .conf directive or with the ignore_user_abort() function. If you do not tell PHP to ignore a user abort and the user aborts, your script will terminate. The one exception is if you have registered a shutdown function using register_shutdown_function(). With a shutdown function, when the remote user hits his STOP button, the next time your script tries to output something PHP will detect that the connection has been aborted and the shutdown function is called. This shutdown function will also get called at the end of your script terminating normally, so to do something different in case of a client disconnect you can use the connection_aborted() function. This function will return TRUE if the connection was aborted.

Your script can also be terminated by the built-in script timer. The default timeout is 30 seconds. It can be changed using the max_execution_time php.ini directive or the corresponding "php_value max_execution_time" Apache .conf directive as well as with the set_time_limit() function. When the timer expires the script will be aborted and as with the above client disconnect case, if a shutdown function has been registered it will be called. Within this shutdown function you can check to see if a timeout caused the shutdown function to be called by calling the connection_timeout() function. This function will return TRUE if a timeout caused the shutdown function to be called.

One thing to note is that both the ABORTED and the TIMEOUT states can be active at the same time. This is possible if you tell PHP to ignore user aborts. PHP will still note the fact that a user may have broken the connection, but the script will keep running. If it then hits the time limit it will be aborted and your shutdown function, if any, will be called. At this point you will find that connection_timeout() and connection_aborted() return TRUE. You can also check both states in a single call by using the connection_status(). This function returns a bitfield of the active states. So, if both states are active it would return 3, for example.

Chapter 21. Persistent Database Connections

Persistent connections are SQL links that do not close when the execution of your script ends. When a persistent connection is requested, PHP checks if there's already an identical persistent connection (that remained open from earlier) - and if it exists, it uses it. If it does not exist, it creates the link. An 'identical' connection is a connection that was opened to the same host, with the same username and the same password (where applicable).

Note: There are other extensions that provide persistent connections, such as the IMAP extension.

People who aren't thoroughly familiar with the way web servers work and distribute the load may mistake persistent connects for what they're not. In particular, they do not give you an ability to open 'user sessions' on the same SQL link, they do not give you an ability to build up a transaction efficiently, and they don't do a whole lot of other things. In fact, to be extremely clear about the subject, persistent connections don't give you any functionality that wasn't possible with their non-persistent brothers.

Why?

This has to do with the way web servers work. There are three ways in which your web server can utilize PHP to generate web pages.

The first method is to use PHP as a CGI "wrapper". When run this way, an instance of the PHP interpreter is created and destroyed for every page request (for a PHP page) to your web server. Because it is destroyed after every request, any resources that it acquires (such as a link to an SQL database server) are closed when it is destroyed. In this case, you do not gain anything from trying to use persistent connections -- they simply don't persist.

The second, and most popular, method is to run PHP as a module in a multiprocess web server, which currently only includes Apache. A multiprocess server typically has one process (the parent) which coordinates a set of processes (its children) who actually do the work of serving up web pages. When each request comes in from a client, it is handed off to one of the children that is not already serving another client. This means that when the same client makes a second request to the server, it may be serviced by a different child process than the first time. What a persistent connection does for you in this case it make it so each child process only needs to connect to your SQL server the first time that it serves a page that makes use of such a connection. When another page then requires a connection to the SQL server, it can reuse the connection that child established earlier.

The last method is to use PHP as a plug-in for a multithreaded web server. Currently PHP 4 has support for ISAPI, WSAPI, and NSAPI (on Windows), which all allow PHP to be used as a plug-in on multithreaded servers like Netscape FastTrack (iPlanet), Microsoft's Internet Information Server (IIS), and O'Reilly's WebSite Pro. The behavior is essentially the same as for the multiprocess model described before. Note that SAPI support is not available in PHP 3.

If persistent connections don't have any added functionality, what are they good for?

The answer here is extremely simple -- efficiency. Persistent connections are good if the overhead to create a link to your SQL server is high. Whether or not this overhead is really high depends on many factors. Like, what kind of database it is, whether or not it sits on the same computer on which your web server sits, how loaded the machine the SQL server sits on is and so forth. The bottom line is that if that connection overhead is high, persistent connections help you considerably. They cause the child process to simply connect only once for its entire lifespan, instead of every time it processes a page that requires connecting to the SQL server. This means that for every child that opened a persistent connection will have its own open persistent connection to the server. For example, if you had 20 different child processes that ran a script that made a persistent connection to your SQL server, you'd have 20 different connections to the SQL server, one from each child.

Note, however, that this can have some drawbacks if you are using a database with connection limits that are exceeded by persistent child connections. If your database has a limit of 16 simultaneous connections, and in the course of a busy server session, 17 child threads attempt to connect, one will not be able to. If there are bugs in your scripts which do not allow the connections to shut down (such as infinite loops), a database with only 32 connections may be rapidly swamped. Check your database documentation for information on handling abandoned or idle connections.

Warning

There are a couple of additional caveats to keep in mind when using persistent connections. One is that when using table locking on a persistent connection, if the script for whatever reason cannot release the lock, then subsequent scripts using the same connection will block indefinitely and may require that you either restart the httpd server or the database server. Another is that when using transactions, a transaction block will also carry over to the next script which uses that connection if script execution ends before the transaction block does. In either case, you can use register_shutdown_function() to register a simple cleanup function to unlock your tables or roll back your transactions. Better yet, avoid the problem entirely by not using persistent connections in scripts which use table locks or transactions (you can still use them elsewhere).

An important summary. Persistent connections were designed to have one-to-one mapping to regular connections. That means that you should always be able to replace persistent connections with non-persistent connections, and it won't change the way your script behaves. It may (and probably will) change the efficiency of the script, but not its behavior!

Chapter 22. Safe Mode

The PHP safe mode is an attempt to solve the shared-server security problem. It is architecturally incorrect to try to solve this problem at the PHP level, but since the alternatives at the web server and OS levels aren't very realistic, many people, especially ISP's, use safe mode for now.

Security and Safe Mode

Table 22-1. Security and Safe Mode Configuration Directives

Name	Default	Changeable
safe_mode	"0"	PHP_INI_SYSTEM
safe_mode_gid	"0"	PHP_INI_SYSTEM
safe_mode_include_dir	NULL	PHP_INI_SYSTEM
safe_mode_exec_dir	""	PHP_INI_SYSTEM
safe_mode_allowed_env_vars	PHP_	PHP_INI_SYSTEM
safe_mode_protected_env_vars	LD_LIBRARY_PATH	PHP_INI_SYSTEM
open_basedir	NULL	PHP_INI_SYSTEM
disable_functions	""	PHP_INI_SYSTEM

For further details and definition of the PHP_INI_* constants see ini_set().

Here is a short explanation of the configuration directives.

safe_mode boolean

Whether to enable PHP's safe mode. Read the Security and chapter for more information.

safe_mode_gid boolean

By default, Safe Mode does a UID compare check when opening files. If you want to relax this to a GID compare, then turn on safe_mode_gid. Whether to use UID (FALSE) or GID (TRUE) checking upon file access.

safe_mode_include_dir string

UID/GID checks are bypassed when including files from this directory and its subdirectories (directory must also be in include_path or full path must including).

As of PHP 4.2.0, this directive can take a semi-colon separated path in a similar fashion to the include_path directive, rather than just a single directory.

safe_mode_exec_dir string

If PHP is used in safe mode, system() and the other functions executing system programs refuse to start programs that are not in this directory.

safe_mode_allowed_env_vars string

Setting certain environment variables may be a potential security breach. This directive contains a comma-delimited list of prefixes. In Safe Mode, the user may only alter environment variables whose names begin with the prefixes supplied here. By default, users will only be able to set environment variables that begin with PHP_ (e.g. PHP_FOO=BAR).

Note: If this directive is empty, PHP will let the user modify ANY environment variable!

safe_mode_protected_env_vars string

This directive contains a comma-delimited list of environment variables that the end user won't be able to change using putenv(). These variables will be protected even if safe_mode_allowed_env_vars is set to allow to change them.

open_basedir string

Limit the files that can be opened by PHP to the specified directory-tree. This directive is NOT affected by whether Safe Mode is turned On or Off.

When a script tries to open a file with, for example, fopen or gzopen, the location of the file is checked. When the file is outside the specified directory-tree, PHP will refuse to open it. All symbolic links are resolved, so it's not possible to avoid this restriction with a symlink.

The special value . indicates that the directory in which the script is stored will be used as base-directory.

Under Windows, separate the directories with a semicolon. On all other systems, separate the directories with a colon. As an Apache module, open_basedir paths from parent directories are now automatically inherited.

The restriction specified with open_basedir is actually a prefix, not a directory name. This means that "open_basedir = /dir/incl" also allows access to "/dir/include" and "/dir/incls" if they exist. When you want to restrict access to only the specified directory, end with a slash. For example: "open_basedir = /dir/incl/"

Note: Support for multiple directories was added in 3.0.7.

The default is to allow all files to be opened.

disable_functions string

This directive allows you to disable certain functions for security reasons. It takes on a comma-dilimited list of function names. disable_functions is not affected by Safe Mode.

This directive must be set in php.ini For example, you cannot set this in httpd.conf.

See also: register_globals, display_errors, and log_errors

When safe_mode is on, PHP checks to see if the owner of the current script matches the owner of the file to be operated on by a file function. For example:
-rw-rw-r-- 1 rasmus rasmus 33 Jul 1 19:20 script.php -rw-r--r-- 1 root root 1116 May 26 18:01 /etc/passwd
Running this script.php
<?php readfile('/etc/passwd'); ?>
results in this error when safe mode is enabled:
Warning: SAFE MODE Restriction in effect. The script whose uid is 500 is not allowed to access /etc/passwd owned by uid 0 in /docroot/script.php on line 2

However, there may be environments where a strict UID check is not appropriate and a relaxed GID check is sufficient. This is supported by means of the safe_mode_gid switch. Setting it to On performs the relaxed GID checking, setting it to Off (the default) performs UID checking.

If instead of safe_mode, you set an open_basedir directory then all file operations will be limited to files under the specified directory For example (Apache httpd.conf example):
<Directory /docroot> php_admin_value open_basedir /docroot </Directory>
If you run the same script.php with this open_basedir setting then this is the result:
Warning: open_basedir restriction in effect. File is in wrong directory in /docroot/script.php on line 2

You can also disable individual functions. Note that the disable_functions directive can not be used outside of the php.ini file which means that you cannot disable functions on a per-virtualhost or per-directory basis in your httpd.conf file. If we add this to our php.ini file:
disable_functions readfile,system
Then we get this output:
Warning: readfile() has been disabled for security reasons in /docroot/script.php on line 2

Functions restricted/disabled by safe mode

This is a still probably incomplete and possibly incorrect listing of the functions limited by safe mode.

Table 22-2. Safe mode limited functions

Function	Limitations
dbmopen()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
dbase_open()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
filepro()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
filepro_rowcount()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
filepro_retrieve()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
*ifx_()**	sql_safe_mode restrictions, (!= safe mode)
*ingres_()**	sql_safe_mode restrictions, (!= safe mode)
*mysql_()**	sql_safe_mode restrictions, (!= safe mode)
pg_loimport()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
posix_mkfifo()	Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed.
putenv()	Obeys the safe_mode_protected_env_vars and safe_mode_allowed_env_vars ini-directives. See also the documentation on putenv()
move_uploaded_file()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
chdir()	Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed.
dl()	This function is disabled in safe mode.
backtick operator	This function is disabled in safe mode.
shell_exec() (functional equivalent of backticks)	This function is disabled in safe mode.
exec()	You can only execute executables within the safe_mode_exec_dir. For practical reasons it's currently not allowed to have `..` components in the path to the executable.
system()	You can only execute executables within the safe_mode_exec_dir. For practical reasons it's currently not allowed to have `..` components in the path to the executable.
passthru()	You can only execute executables within the safe_mode_exec_dir. For practical reasons it's currently not allowed to have `..` components in the path to the executable.
popen()	You can only execute executables within the safe_mode_exec_dir. For practical reasons it's currently not allowed to have `..` components in the path to the executable.
mkdir()	Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed.
rmdir()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
rename()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed.
unlink()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed.
copy()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed. (on `source` and `target`)
chgrp()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
chown()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.
chmod()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. In addition, you cannot set the SUID, SGID and sticky bits
touch()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed.
symlink()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed. (note: only the target is checked)
link()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed. (note: only the target is checked)
getallheaders()	In safe mode, headers beginning with 'authorization' (case-insensitive) will not be returned. Warning: this is broken with the aol-server implementation of getallheaders()!
header()	In safe mode, the uid of the script is added to the `realm` part of the `WWW-Authenticate` header if you set this header (used for HTTP Authentication).
highlight_file(), show_source()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed. (note: only affected since PHP 4.2.1)
parse_ini_file()	Checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed. Checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed. (note: only affected since PHP 4.2.1)
Any function that uses `php4/main/fopen_wrappers.c`	??

Chapter 23. Using PHP from the command line

As of version 4.3, PHP supports a new SAPI type (Server Application Programming Interface) named CLI which means Command Line Interface. As the name implies, this SAPI type main focus is on developing shell (or desktop as well) applications with PHP. There are quite some differences between the CLI SAPI and other SAPIs which are further explained throughout this chapter.

The CLI SAPI was released for the first time with PHP 4.2.0, but was still experimental back then and had to be explicitely enabled with --enable-cli when running ./configure. Since PHP 4.3.0 the CLI SAPI is no longer experimental and is therefore always built and installed as the php (called php.exe on Windows) binary.

Remarkable differences of the CLI SAPI compared to other SAPIs:

Unlike the CGI SAPI, no headers are written to the output.
Though the CGI SAPI provies a way to suppress HTTP headers, there's not equivalent switch to enable them in the CLI SAPI.
CLI is started up in quiet mode by default. But -q switch is kept for compatibility so that you can use older CGI scripts.
It does not change the working directory to that of the script. (-C switch kept for compatibility)
Plain text error messages (no HTML formatting).

The are certain php.ini directives which are overriden by the CLI SAPI because they do not make sense in shell environments:

Table 23-1. Overriden php.ini directives

Directive	`CLI SAPI` default value	Comment
html_errors	`FALSE`	It can be quite hard to read the error message in your shell when it's cluttered with all those meaningless `HTML` tags, therefore this directive defaults to `FALSE`.
implicit_flush	`TRUE`	It is desired that any output coming from print(), echo() and friends is immidiately written to the output and not cached in any buffer. You still can use output buffering if you want to defer or manipulate standard output.
max_execution_time	0 (unlimited)	Due to endless possibilities of using `PHP` in shell environments, the maximum execution time has been set to unlimited. Whereas applications written for the web are executed within splits of a seconds, shell application tend to have a much longer execution time.
register_argc_argv	`TRUE`	The global `PHP` variables `$argc` (number of arguments passed to the application) and `$argv` (array of the actual arguments) are always registered and filled in with the appropriate values when using the `CLI SAPI`.

Note: These directives cannot be initialzied with another value from the configuration file php.ini or a custom one (if specified). This is a limitation because those default values are applied after all configuration files have been parsed. However, their value can be changed during runtime (which does not make sense for all of those directives, e.g. register_argc_argv).

To ease working in the shell environment, the following constants are defined:

Table 23-2. CLI specific Constants

Constant Description

STDIN

An already opened stream to stdin. This saves opening it with

$stdin = fopen('php://stdin', 'r');

STDOUT

An already opened stream to stdout. This saves opening it with

$stdout = fopen('php://stdout', 'w');

STDERR

An already opened stream to stdout. This saves opening it with

$stderr = fopen('php://stderr', 'w');

Given the above, you don't need to open e.g. a stream for stderr yourself but simply use the constant instead of the stream resource:
php -r 'fwrite(STDERR, "stderr\n");'
You do not need to explicitly close these streams, this is automatically done by PHP.

The CLI SAPI does not change the current directory to the directory of the executed script !
Example showing the difference to the CGI SAPI:
<?php /* Our simple test application */ echo getcwd(), "\n"; ?>
When using the CGI version, the output is
$ pwd /tmp $ php-cgi -f another_directory/test.php /tmp/another_directory
This clearly shows that PHP changes its current directory to the one of the executed script.
Using the CLI SAPI yields:
$ pwd /tmp $ php -f another_directory/test.php /tmp
This allows greater flexibility when writing shell tools in PHP.
Note: The CGI SAPI supports the CLI SAPI behaviour by means of the -C switch when ran from the command line.

The list of command line options provided by the PHP binary can be queried anytime by running PHP with the -h switch:
Usage: php [options] [-f] <file> [args...] php [options] -r <code> [args...] php [options] [-- args...] -s Display colour syntax highlighted source. -w Display source with stripped comments and whitespace. -f <file> Parse <file>. -v Version number -c <path>|<file> Look for php.ini file in this directory -a Run interactively -d foo[=bar] Define INI entry foo with value 'bar' -e Generate extended information for debugger/profiler -z <file> Load Zend extension <file>. -l Syntax check only (lint) -m Show compiled in modules -i PHP information -r <code> Run PHP <code> without using script tags <?..?> -h This help args... Arguments passed to script. Use -- args when first argument starts with - or script is read from stdin

The CLI SAPI has three different ways of getting the PHP code you want to execute:

Telling PHP to execute a certain file.
php my_script.php php -f my_script.php
Both ways (using the -f switch or not) execute the given file my_script.php. You can choose any file to execute, your PHP scripts do not have to end with the .php extension but can give them any name or extension you want them to have.
Pass the PHP code to execute directly on the command line.
php -r 'print_r(get_defined_constants());'
Special care has to be taken in regards of shell variable substitution and quoting usage.
Note: Read the example carefully, thera are no beginning or ending tags! The -r switch simply does not need them. Using them will lead to a parser error.
Provide the PHP code to execute via standard input (stdin).
This gives the powerful ability to dynamically create PHP code and feed it to the binary, as shown in this (fictional) example:
$ some_application | some_filter | php | sort -u >final_output.txt

You cannot combine any of the three ways to execute code.

Like every shell application, the PHP binary accepts a number of arguments but also your PHP script can receive them. The number of arguments which can be passed to your script is not limited by PHP (the shell has a certain size limit in numbers of characters which can be passed; usually you won't hit this limit). The arguments passed to your script are available in the global array $argv. The zero index always contains the script name (which is - in case the PHP code is coming from either standard input or from the command line switch -r). The second registered global variable is $argc which contains the number of elements in the $argv array (not the number of arguments passed to the script).

As long as the arguments you want to pass to your script do not start with the - character, there's nothing special to watch out for. Passing an argument to your script which starts with a - will cause trouble because PHP itself thinks it has to handle it. To prevent this use the argument list separator --. After the argument has been parsed by PHP, every argument following it is passed untoched/unparsed to your script.

# This will not execute the given code but will show the PHP usage
$ php -r 'var_dump($argv);' -h
Usage: php [options] [-f] <file> [args...]
[...]

# This will pass the '-h' argument to your script and prevent PHP from showing it's usage
$ php -r 'var_dump($argv);' -- -h
array(2) {
  [0]=>
  string(1) "-"
  [1]=>
  string(2) "-h"
}

However, there's another way of using PHP for shell scripting. You can write a script where the first line starts with #!/usr/bin/php and then following the normal PHP code included within the PHP starting and end tags and set the execution attributes of the file appropriately. This way it can be executed like a normal shell or perl script:
#!/usr/bin/php <?php var_dump($argv); ?>
Assuming this file is named test in the current directory, we can now do the following:
$ chmod 755 test $ ./test -h -- foo array(4) { [0]=> string(6) "./test" [1]=> string(2) "-h" [2]=> string(2) "--" [3]=> string(3) "foo" }
As you see no care has to be taken when passing parameters to your script which start with -.

Table 23-3. Command line options

Option Description

-s

Display colour syntax highlighted source.

This option uses the internal mechanism to parse the file and produces a HTML highlighted version of it and writes it to standard output. Note that all it does it to generate a block of <code> [...] </code> HTML tags, no HTML headers.

Note: This option does not work together with the -r option.

-w

Display source with stripped comments and whitespace.

Note: This option does not work together with the -r option.

-f

Parses and executed the given filename to the -f option. This switch is optional and can be left out. Only providing the filename to execute is sufficient.

-v

Writes the PHP, PHP SAPI, and Zend version to standard output, e.g.
$ php -v PHP 4.3.0-dev (cli), Copyright (c) 1997-2002 The PHP Group Zend Engine v1.2.1, Copyright (c) 1998-2002 Zend Technologies

-c

With this option one can either specify a directory where to look for php.ini or you can specify a custom INI file directly (which does not need to be named php.ini), e.g.:
$ php -c /custom/directory/ my_script.php $ php -c /custom/directory/custom-file.ini my_script.php

-a

Runs PHP interactively.

-d

This option allows to set a custom value for any of the configuration directives allowed in php.ini. The syntax is:
-d configuration_directive[=value]

Examples:
# Ommiting the value part will set the given configuration directive to "1" $ php -d max_execution_time -r '$foo = ini_get("max_execution_time"); var_dump($foo);' string(1) "1" # Passing an empty value part will set the configuration directive to "" php -d max_execution_time= -r '$foo = ini_get("max_execution_time"); var_dump($foo);' string(0) "" # The configuration directive will be set to anything passed after the '=' character $ php -d max_execution_time=20 -r '$foo = ini_get("max_execution_time"); var_dump($foo);' string(2) "20" $ php -d max_execution_time=doesntmakesense -r '$foo = ini_get("max_execution_time"); var_dump($foo);' string(15) "doesntmakesense"

-e

Generate extended information for debugger/profiler.

-z

Load Zend extension. If only a filename is given, PHP tries to load this extension from the current default library path on your system (usually specified /etc/ld.so.conf on Linux systems). Passing a filename with an absolute path information will not use the systems library search path. A relative filename with a directory information will tell PHP only to try to load the extension relative to the current directory.

-l

This option provides a convenient way to only perform a syntax check on the given PHP code. On succes, the text No syntax errors detected in <filename> is written to standard output and the shell return code is 0. On failure, the text Errors parsing <filename> in addition to the internal parser error message is written to standard output and the shell return code is set to 255.

This option won't find fatal errors (like undefined functions). Use -f if you would like to test for fatal errors too.

Note: This option does not work together with the -r option.

-m

Using this option, PHP prints out the built in (and loaded) PHP and Zend modules:
$ php -m [PHP Modules] xml tokenizer standard session posix pcre overload mysql mbstring ctype [Zend Modules]

-i This command line option calls phpinfo(), and prints out the results. If PHP is not working well, it is advisable to make a php -i and see if any error messages are printed out before or in place of the information tables. Beware that the output is in HTML and therefore quite huge.

-r

This option allows execution of PHP right from within the command line. The PHP start and end tags (<?php and ?>) are not needed and will cause a parser errors.

Note: Care has to be taken when using this form of PHP to not collide with command line variable substitution done by the shell.
Example showing a parser error
$ php -r "$foo = get_defined_constants();"
Command line code(1) : Parse error - parse error, unexpected '='
The problem here is that the sh/bash performs variable substritution even when using double quotes ". Since the variable $foo is unlikely to be defined, it expands to nothing which results in being the code passed to PHP for executin in fact reads:
$ php -r " = get_defined_constants();"
The correct way would be to use single quotes '. variables in strings quoted with single quotes are not expanded by sh/bash.
$ php -r '$foo = get_defined_constants(); var_dump($foo);'
array(370) {
  ["E_ERROR"]=>
  int(1)
  ["E_WARNING"]=>
  int(2)
  ["E_PARSE"]=>
  int(4)
  ["E_NOTICE"]=>
  int(8)
  ["E_CORE_ERROR"]=>
  [...]
If you are using a shell different from sh/bash, you might experience further issues. Feel free to open a bug report or send a mail to phpdoc@lists.php.net. One still can easily run intro troubles when trying to get shell variables into the code or using backslashes for escaping. You've been warned.

-h With this option, you can get information about the actual list of command line options and some one line descriptions about what they do.

The PHP executable can be used to run PHP scripts absolutely independent from the web server. If you are on a Unix system, you should add a special first line to your PHP script, and make it executable, so the system will know, what program should run the script. On a Windows platform you can associate php.exe with the double click option of the .php files, or you can make a batch file to run the script through PHP. The first line added to the script to work on Unix won't hurt on Windows, so you can write cross platform programs this way. A simple example of writing a command line PHP program can be found below.

Example 23-1. Script intended to be run from command line (script.php)

#!/usr/bin/php
<?php

if ($argc != 2 || in_array($argv[1], array('--help', '-help', '-h', '-?'))) {
?>

This is a command line PHP script with one option.

  Usage:
  <?php echo $argv[0]; ?> <option>

  <option> can be some word you would like
  to print out. With the --help, -help, -h,
  or -? options, you can get this help.

<?php
} else {
    echo $argv[1];
}
?>

In the script above, we used the special first line to indicate, that this file should be run by PHP. We work with a CLI version here, so there will be no HTTP header printouts. There are two variables you can use while writing command line applications with PHP: $argc and $argv. The first is the number of arguments plus one (the name of the script running). The second is an array containing the arguments, starting with the script name as number zero ($argv[0]).

In the program above we checked if there are less or more than one arguments. Also if the argument was --help, -help, -h or -?, we printed out the help message, printing the script name dynamically. If we received some other argument we echoed that out.

If you would like to run the above script on Unix, you need to make it executable, and simply call it as script.php echothis or script.php -h. On Windows, you can make a batch file for this task:

Example 23-2. Batch file to run a command line PHP script (script.bat)

@c:\php\php.exe script.php %1 %2 %3 %4

Assuming, you named the above program as script.php, and you have your php.exe in c:\php\php.exe this batch file will run it for you with your added options: script.bat echothis or script.bat -h.

See also the Readline extension documentation for more functions you can use to enhance your command line applications in PHP.

IV. Function Reference

Table of Contents
I. Apache-specific Functions
II. Array Functions
III. Aspell functions [deprecated]
IV. BCMath Arbitrary Precision Mathematics Functions
V. Bzip2 Compression Functions
VI. Calendar functions
VII. CCVS API Functions
VIII. COM support functions for Windows
IX. Class/Object Functions
X. ClibPDF functions
XI. Crack functions
XII. CURL, Client URL Library Functions
XIII. Cybercash payment functions
XIV. Crédit Mutuel CyberMUT functions
XV. Cyrus IMAP administration functions
XVI. Character type functions
XVII. Database (dbm-style) abstraction layer functions
XVIII. Date and Time functions
XIX. dBase functions
XX. DBM Functions
XXI. dbx functions
XXII. DB++ Functions
XXIII. Direct IO functions
XXIV. Directory functions
XXV. DOM XML functions
XXVI. .NET functions
XXVII. Error Handling and Logging Functions
XXVIII. FrontBase Functions
XXIX. filePro functions
XXX. Filesystem functions
XXXI. Forms Data Format functions
XXXII. FriBiDi functions
XXXIII. FTP functions
XXXIV. Function Handling functions
XXXV. Gettext
XXXVI. GMP functions
XXXVII. HTTP functions
XXXVIII. Hyperwave functions
XXXIX. Hyperwave API functions
XL. iconv functions
XLI. Image functions
XLII. IMAP, POP3 and NNTP functions
XLIII. Informix functions
XLIV. InterBase functions
XLV. Ingres II functions
XLVI. IRC Gateway Functions
XLVII. PHP / Java Integration
XLVIII. LDAP functions
XLIX. Mail functions
L. mailparse functions
LI. Mathematical Functions
LII. Multi-Byte String Functions
LIII. MCAL functions
LIV. Mcrypt Encryption Functions
LV. MCVE Payment Functions
LVI. Mhash Functions
LVII. Mimetype Functions
LVIII. Microsoft SQL Server functions
LIX. Ming functions for Flash
LX. Miscellaneous functions
LXI. mnoGoSearch Functions
LXII. mSQL functions
LXIII. MySQL Functions
LXIV. Mohawk Software session handler functions
LXV. muscat functions
LXVI. Network Functions
LXVII. Ncurses terminal screen control functions
LXVIII. Lotus Notes functions
LXIX. Unified ODBC functions
LXX. Object Aggregation/Composition Functions
LXXI. Oracle 8 functions
LXXII. OpenSSL functions
LXXIII. Oracle functions
LXXIV. Ovrimos SQL functions
LXXV. Output Control Functions
LXXVI. Object property and method call overloading
LXXVII. PDF functions
LXXVIII. Verisign Payflow Pro functions
LXXIX. PHP Options&Information
LXXX. POSIX functions
LXXXI. PostgreSQL functions
LXXXII. Process Control Functions
LXXXIII. Program Execution functions
LXXXIV. Printer functions
LXXXV. Pspell Functions
LXXXVI. GNU Readline
LXXXVII. GNU Recode functions
LXXXVIII. Regular Expression Functions (Perl-Compatible)
LXXXIX. qtdom functions
XC. Regular Expression Functions (POSIX Extended)
XCI. Semaphore, Shared Memory and IPC Functions
XCII. SESAM database functions
XCIII. Session handling functions
XCIV. Shared Memory Functions
XCV. Shockwave Flash functions
XCVI. SNMP functions
XCVII. Socket functions
XCVIII. String functions
XCIX. Sybase functions
C. Tokenizer functions
CI. URL Functions
CII. Variable Functions
CIII. vpopmail functions
CIV. W32api functions
CV. WDDX Functions
CVI. XML parser functions
CVII. XML-RPC functions
CVIII. XSLT functions
CIX. YAZ functions
CX. YP/NIS Functions
CXI. Zip File Functions (Read Only Access)
CXII. Zlib Compression Functions

I. Apache-specific Functions

Introduction

These functions are only available when running PHP as an Apache 1.x module.

Installation

For PHP installation on Apache 1.x see the Apache section in the installation chapter.

Runtime Configuration

The behaviour of the Apache PHP module is affected by settings in php.ini. Configuration settings from php.ini may be overridden by php_flag settings in the server configuration file or local .htaccess files.

Example 1. Turning off PHP parsing for a directory using .htaccess

php_flag engine off

Table 1. Apache configuration options

Name	Default	Changeable	Function
engine	On	PHP_INI_ALL	turns PHP parsing on or off
child_terminate	Off	PHP_INI_ALL	specify whether PHP scripts may request child process termination on end of request, see also apache_child_terminate()
last_modified	Off	PHP_INI_ALL	send PHP scripts modification date as Last-Modified: header for this request
xbit_hack	Off	PHP_INI_ALL	parse files with executable bit set as PHP regardles of their file ending

Here is a short explanation of the configuration directives.

engine boolean: This directive is really only useful in the Apache module version of PHP. It is used by sites that would like to turn PHP parsing on and off on a per-directory or per-virtual server basis. By putting engine off in the appropriate places in the httpd.conf file, PHP can be enabled or disabled.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Table of Contents
apache_child_terminate -- Terminate apache process after this request
apache_lookup_uri -- Perform a partial request for the specified URI and return all info about it
apache_note -- Get and set apache request notes
apache_request_headers -- Fetch all HTTP request headers
apache_response_headers -- Fetch all HTTP response headers
apache_setenv -- Set an Apache subprocess_env variable
ascii2ebcdic -- Translate string from ASCII to EBCDIC
ebcdic2ascii -- Translate string from EBCDIC to ASCII
getallheaders -- Fetch all HTTP request headers
virtual -- Perform an Apache sub-request

apache_child_terminate

(PHP 4 >= 4.0.5)

apache_child_terminate -- Terminate apache process after this request

Description

bool apache_child_terminate ( void)

apache_child_terminate() will register the Apache process executing the current PHP request for termination once execution of PHP code it is completed. It may be used to terminate a process after a script with high memory consumption has been run as memory will usually only be freed internally but not given back to the operating system.

Note: The availability of this feature is controlled by the php.ini directive apache.child_terminate, which is set to off by default.
This feature is also not available on multithreaded versions of apache like the win32 version.

apache_lookup_uri

(PHP 3>= 3.0.4, PHP 4 )

apache_lookup_uri -- Perform a partial request for the specified URI and return all info about it

Description

object apache_lookup_uri ( string filename)

This performs a partial request for a URI. It goes just far enough to obtain all the important information about the given resource and returns this information in a class. The properties of the returned class are:

status

the_request

status_line

method

content_type

handler

uri

filename

path_info

args

boundary

no_cache

no_local_copy

allowed

send_bodyct

bytes_sent

byterange

clength

unparsed_uri

mtime

request_time

Note: apache_lookup_uri() only works when PHP is installed as an Apache module.

apache_note

int virtual ( string filename)

virtual() is an Apache-specific function which is equivalent to  in mod_include. It performs an Apache sub-request. It is useful for including CGI scripts or .shtml files, or anything else that you would parse through Apache. Note that for a CGI script, the script must generate valid CGI headers. At the minimum that means it must generate a Content-type header. For PHP files, you need to use include() or require(); virtual() cannot be used to include a document which is itself a PHP file.

To run the sub-request, all buffers are terminated and flushed to the browser, pending headers are sent too.

II. Array Functions

Introduction

These functions allow you to interact with and manipulate arrays in various ways. Arrays are essential for storing, managing, and operating on sets of variables.

Simple and multi-dimensional arrays are supported, and may be either user created or created by another function. There are specific database handling functions for populating arrays from database queries, and several functions return arrays.

Please see the Arrays section of the manual for a detailed explanation of how arrays are implemented and used in PHP.

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are always available as part of the PHP core.

CASE_LOWER (integer): CASE_LOWER is used with array_change_key_case() and is used to convert array keys to lower case. This is also the default case for array_change_key_case().
CASE_UPPER (integer): CASE_UPPER is used with array_change_key_case() and is used to convert array keys to upper case.

Sorting order flags:

SORT_ASC (integer): SORT_ASC is used with array_multisort() to sort in ascending order.
SORT_DESC (integer): SORT_DESC is used with array_multisort() to sort in descending order.

Sorting type flags: used by various sort functions

SORT_REGULAR (integer): SORT_REGULAR is used to compare items normally.
SORT_NUMERIC (integer): SORT_NUMERIC is used to compare items numerically.
SORT_STRING (integer): SORT_STRING is used to compare items as strings.

array_change_key_case

(PHP 4 >= 4.2.0)

array_change_key_case -- Returns an array with all string keys lowercased or uppercased

Description

array array_change_key_case ( array input [, int case])

array_change_key_case() changes the keys in the input array to be all lowercase or uppercase. The change depends on the last optional case parameter. You can pass two constants there, CASE_UPPER and CASE_LOWER. The default is CASE_LOWER. The function will leave number indices as is.

Example 1. array_change_key_case() example

$input_array = array("FirSt" => 1, "SecOnd" => 4);
print_r(array_change_key_case($input_array, CASE_UPPER));

The printout of the above program will be:
Array ( [FIRST] => 1 [SECOND] => 2 )

array_chunk

(PHP 4 >= 4.2.0)

array_chunk -- Split an array into chunks

Description

array array_chunk ( array input, int size [, bool preserve_keys])

array_chunk() splits the array into several arrays with size values in them. You may also have an array with less values at the end. You get the arrays as members of a multidimensional array indexed with numbers starting from zero.

By setting the optional preserve_keys parameter to TRUE, you can force PHP to preserve the original keys from the input array. If you specify FALSE new number indices will be used in each resulting array with indices starting from zero. The default is FALSE.

Example 1. array_chunk() example

$input_array = array('a', 'b', 'c', 'd', 'e');
print_r(array_chunk($input_array, 2));
print_r(array_chunk($input_array, 2, TRUE));

The printout of the above program will be:
Array ( [0] => Array ( [0] => a [1] => b ) [1] => Array ( [0] => c [1] => d ) [2] => Array ( [0] => e ) ) Array ( [0] => Array ( [0] => a [1] => b ) [1] => Array ( [2] => c [3] => d ) [2] => Array ( [4] => e ) )

array_count_values

(PHP 4 )

array_count_values -- Counts all the values of an array

Description

array array_count_values ( array input)

array_count_values() returns an array using the values of the input array as keys and their frequency in input as values.

Example 1. array_count_values() example
$array = array (1, "hello", 1, "world", "hello"); print_r(array_count_values ($array));
The printout of the above program will be:
Array ( [1] => 2 [hello] => 2 [world] => 1 )

array_diff

(PHP 4 >= 4.0.1)

array_diff -- Computes the difference of arrays

Description

array array_diff ( array array1, array array2 [, array ...])

array_diff() returns an array containing all the values of array1 that are not present in any of the other arguments. Note that keys are preserved.

Example 1. array_diff() example
$array1 = array ("a" => "green", "red", "blue", "red"); $array2 = array ("b" => "green", "yellow", "red"); $result = array_diff ($array1, $array2);

This makes $result have array ("blue");. Multiple occurrences in $array1 are all treated the same way.

Note: Two elements are considered equal if and only if (string) $elem1 === (string) $elem2. In words: when the string representation is the same.

Note: Please note that this function only checks one dimension of a n-dimensional array. Of course you can check deeper dimensions by using array_diff($array1[0], $array2[0]);.

Warning

This was broken in PHP 4.0.4!

array_fill

(PHP 4 >= 4.2.0)

array_fill -- Fill an array with values

Description

array array_fill ( int start_index, int num, mixed value)

array_fill() fills an array with num entries of the value of the value parameter, keys starting at the start_index parameter.

Example 1. array_fill() example
$a = array_fill(5, 6, 'banana');
$a now has the following entries using print_r():
Array ( [5] => banana [6] => banana [7] => banana [8] => banana [9] => banana [10] => banana )

array_filter

(PHP 4 >= 4.0.6)

array_filter -- Filters elements of an array using a callback function

Description

array array_filter ( array input [, mixed callback])

array_filter() returns an array containing all the elements of input filtered according a callback function. If the input is an associative array the keys are preserved.

Example 1. array_filter() example
function odd($var) { return ($var % 2 == 1); } function even($var) { return ($var % 2 == 0); } $array1 = array ("a"=>1, "b"=>2, "c"=>3, "d"=>4, "e"=>5); $array2 = array (6, 7, 8, 9, 10, 11, 12); echo "Odd :\n"; print_r(array_filter($array1, "odd")); echo "Even:\n"; print_r(array_filter($array2, "even"));
The printout of the program above will be:
Odd : Array ( [a] => 1 [c] => 3 [e] => 5 ) Even: Array ( [0] => 6 [2] => 8 [4] => 10 [6] => 12 )

Note: Instead of a function name, an array containing an object reference and a method name can also be supplied.

Users may not change the array itself from the callback function. e.g. Add/delete an element, unset the array that array_filter() is applied to. If the array is changed, the behavior of this function is undefined.

See also array_map() and array_reduce().

array_flip

(PHP 4 )

array_flip -- Flip all the values of an array

Description

array array_flip ( array trans)

array_flip() returns an array in flip order, i.e. keys from trans become values and trans's values become keys.

Note that the values of trans need to be valid keys, i.e. they need to be either integer or string. A warning will be emitted if a value has the wrong type, and the key/value pair in question will not be flipped.

If a value has several occurrences, the latest key will be used as its values, and all others will be lost.

array_flip() returns FALSE if it fails.

Example 1. array_flip() example
$trans = array_flip ($trans); $original = strtr ($str, $trans);

Example 2. array_flip() example : collision
$trans = array ("a" => 1, "b" => 1, "c" => 2); $trans = array_flip ($trans); print_r($trans);
now $trans is :
Array ( [1] => b [2] => c )

array_intersect

(PHP 4 >= 4.0.1)

array_intersect -- Computes the intersection of arrays

Description

array array_intersect ( array array1, array array2 [, array ...])

array_intersect() returns an array containing all the values of array1 that are present in all the arguments. Note that keys are preserved.

Example 1. array_intersect() example
$array1 = array ("a" => "green", "red", "blue"); $array2 = array ("b" => "green", "yellow", "red"); $result = array_intersect ($array1, $array2);
This makes $result have
Array ( [a] => green [0] => red )

Note: Two elements are considered equal if and only if (string) $elem1 === (string) $elem2. In words: when the string representation is the same.

Warning

This was broken in PHP 4.0.4!

array_key_exists

(PHP 4 >= 4.1.0)

array_key_exists -- Checks if the given key or index exists in the array

Description

bool array_key_exists ( mixed key, array search)

array_key_exists() returns TRUE if the given key is set in the array. key can be any value possible for an array index.

Example 1. array_key_exists() example
$search_array = array("first" => 1, "second" => 4); if (array_key_exists("first", $search_array)) { echo "The 'first' element is in the array"; }

Note: The name of this function is key_exists() in PHP version 4.0.6.

array_keys

(PHP 4 )

array_keys -- Return all the keys of an array

Description

array array_keys ( array input [, mixed search_value])

array_keys() returns the keys, numeric and string, from the input array.

If the optional search_value is specified, then only the keys for that value are returned. Otherwise, all the keys from the input are returned.

Example 1. array_keys() example
$array = array (0 => 100, "color" => "red"); print_r(array_keys ($array)); $array = array ("blue", "red", "green", "blue", "blue"); print_r(array_keys ($array, "blue")); $array = array ("color" => array("blue", "red", "green"), "size" => array("small", "medium", "large")); print_r(array_keys ($array));
The printout of the program above will be:
Array ( [0] => 0 [1] => color ) Array ( [0] => 0 [1] => 3 [2] => 4 ) Array ( [0] => color [1] => size )

Note: This function was added to PHP 4, below is an implementation for those still using PHP 3.
Example 2. Implementation of array_keys() for PHP 3 users
function array_keys ($arr, $term="") {
    $t = array();
    while (list($k,$v) = each($arr)) {
        if ($term && $v != $term) {
            continue;
        }
        $t[] = $k;
    }
    return $t;
}

array_map

(PHP 4 >= 4.0.6)

array_map -- Applies the callback to the elements of the given arrays

Description

array array_map ( mixed callback, array arr1 [, array arr2...])

array_map() returns an array containing all the elements of arr1 after applying the callback function to each one. The number of parameters that the callback function accepts should match the number of arrays passed to the array_map()

Example 1. array_map() example
function cube($n) { return $n*$n*$n; } $a = array(1, 2, 3, 4, 5); $b = array_map("cube", $a); print_r($b);
This makes $b have:
Array ( [0] => 1 [1] => 8 [2] => 27 [3] => 64 [4] => 125 )

Example 2. array_map() - using more arrays
function show_Spanish($n, $m) { return "The number $n is called $m in Spanish"; } function map_Spanish($n, $m) { return array ($n => $m); } $a = array(1, 2, 3, 4, 5); $b = array("uno", "dos", "tres", "cuatro", "cinco"); $c = array_map("show_Spanish", $a, $b); print_r($c); $d = array_map("map_Spanish", $a , $b); print_r($d);
This results:
// printout of $c Array ( [0] => The number 1 is called uno in Spanish [1] => The number 2 is called dos in Spanish [2] => The number 3 is called tres in Spanish [3] => The number 4 is called cuatro in Spanish [4] => The number 5 is called cinco in Spanish ) // printout of $d Array ( [0] => Array ( [1] => uno ) [1] => Array ( [2] => dos ) [2] => Array ( [3] => tres ) [3] => Array ( [4] => cuatro ) [4] => Array ( [5] => cinco ) )

Usually when using two or more arrays, they should be of equal length because the callback function is applied in parallel to the corresponding elements. If the arrays are of unequal length, the shortest one will be extended with empty elements.

An interesting use of this function is to construct an array of arrays, which can be easily performed by using NULL as the name of the callback function

Example 3. Creating an array of arrays
$a = array(1, 2, 3, 4, 5); $b = array("one", "two", "three", "four", "five"); $c = array("uno", "dos", "tres", "cuatro", "cinco"); $d = array_map(null, $a, $b, $c); print_r($d);

The printout of the program above will be:
Array ( [0] => Array ( [0] => 1 [1] => one [2] => uno ) [1] => Array ( [0] => 2 [1] => two [2] => dos ) [2] => Array ( [0] => 3 [1] => three [2] => tres ) [3] => Array ( [0] => 4 [1] => four [2] => cuatro ) [4] => Array ( [0] => 5 [1] => five [2] => cinco ) )

array_merge_recursive

(PHP 4 >= 4.0.1)

array_merge_recursive -- Merge two or more arrays recursively

Description

array array_merge_recursive ( array array1, array array2 [, array ...])

array_merge_recursive() merges the elements of two or more arrays together so that the values of one are appended to the end of the previous one. It returns the resulting array.

If the input arrays have the same string keys, then the values for these keys are merged together into an array, and this is done recursively, so that if one of the values is an array itself, the function will merge it with a corresponding entry in another array too. If, however, the arrays have the same numeric key, the later value will not overwrite the original value, but will be appended.

Example 1. array_merge_recursive() example
$ar1 = array ("color" => array ("favorite" => "red"), 5); $ar2 = array (10, "color" => array ("favorite" => "green", "blue")); $result = array_merge_recursive ($ar1, $ar2);
The $result will be:
Array ( [color] => Array ( [favorite] => Array ( [0] => red [1] => green ) [0] => blue ) [0] => 5 [1] => 10 )

array_merge

(PHP 4 )

array_merge -- Merge two or more arrays

Description

array array_merge ( array array1, array array2 [, array ...])

array_merge() merges the elements of two or more arrays together so that the values of one are appended to the end of the previous one. It returns the resulting array.

If the input arrays have the same string keys, then the later value for that key will overwrite the previous one. If, however, the arrays contain numeric keys, the later value will not overwrite the original value, but will be appended.

Example 1. array_merge() example
$array1 = array ("color" => "red", 2, 4); $array2 = array ("a", "b", "color" => "green", "shape" => "trapezoid", 4); $result = array_merge ($array1, $array2);
The $result will be:
Array ( [color] => green [0] => 2 [1] => 4 [2] => a [3] => b [shape] => trapezoid [4] => 4 )

Example 2. Simple array_merge() example
$array1 = array(); $array2 = array(1 => "data"); $result = array_merge($array1, $array2);
Don't forget that numeric keys will be renumbered!
Array ( [0] => data )

If you want to completely preserve the arrays and just want to append them to each other, use the + operator:
$array1 = array(); $array2 = array(1 => "data"); $result = $array1 + $array2;
The numeric key will be preserved and thus the association remains.
Array ( [1] => data )

Note: Shared keys will be overwritten on a first-come first-served basis.

array_multisort

(PHP 4 )

array_multisort -- Sort multiple or multi-dimensional arrays

Description

bool array_multisort ( array ar1 [, mixed arg [, mixed ... [, array ...]]])

array_multisort() can be used to sort several arrays at once or a multi-dimensional array according by one of more dimensions. It maintains key association when sorting.

The input arrays are treated as columns of a table to be sorted by rows - this resembles the functionality of SQL ORDER BY clause. The first array is the primary one to sort by. The rows (values) in that array that compare the same are sorted by the next input array, and so on.

The argument structure of this function is a bit unusual, but flexible. The very first argument has to be an array. Subsequently, each argument can be either an array or a sorting flag from the following lists.

Sorting order flags:

SORT_ASC - sort in ascending order
SORT_DESC - sort in descending order

Sorting type flags:

SORT_REGULAR - compare items normally
SORT_NUMERIC - compare items numerically
SORT_STRING - compare items as strings

No two sorting flags of the same type can be specified after each array. The sorting flags specified after an array argument apply only to that array - they are reset to default SORT_ASC and SORT_REGULAR after before each new array argument.

Returns TRUE on success or FALSE on failure.

Example 1. Sorting multiple arrays
$ar1 = array ("10", 100, 100, "a"); $ar2 = array (1, 3, "2", 1); array_multisort ($ar1, $ar2);

In this example, after sorting, the first array will contain 10, "a", 100, 100. The second array will contain 1, 1, "2", 3. The entries in the second array corresponding to the identical entries in the first array (100 and 100) were sorted as well.

Example 2. Sorting multi-dimensional array
$ar = array (array ("10", 100, 100, "a"), array (1, 3, "2", 1)); array_multisort ($ar[0], SORT_ASC, SORT_STRING, $ar[1], SORT_NUMERIC, SORT_DESC);

In this example, after sorting, the first array will contain 10, 100, 100, "a" (it was sorted as strings in ascending order), and the second one will contain 1, 3, "2", 1 (sorted as numbers, in descending order).

array_pad

(PHP 4 )

array_pad -- Pad array to the specified length with a value

Description

array array_pad ( array input, int pad_size, mixed pad_value)

array_pad() returns a copy of the input padded to size specified by pad_size with value pad_value. If pad_size is positive then the array is padded on the right, if it's negative then on the left. If the absolute value of pad_size is less than or equal to the length of the input then no padding takes place.

Example 1. array_pad() example
$input = array (12, 10, 9); $result = array_pad ($input, 5, 0); // result is array (12, 10, 9, 0, 0) $result = array_pad ($input, -7, -1); // result is array (-1, -1, -1, -1, 12, 10, 9) $result = array_pad ($input, 2, "noop"); // not padded

array_pop

(PHP 4 )

array_pop -- Pop the element off the end of array

Description

mixed array_pop ( array array)

array_pop() pops and returns the last value of the array, shortening the array by one element. If array is empty (or is not an array), NULL will be returned.

Example 1. array_pop() example
$stack = array ("orange", "banana", "apple", "raspberry"); $fruit = array_pop ($stack);
After this, $stack will have only 3 elements:
Array ( [0] => orange [1] => banana [2] => apple )
and rasberry will be assigned to $fruit.

Warning

This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE, such as 0 or "". Please read the section on Booleans for more information. Use the === operator for testing the return value of this function.

array_push

(PHP 4 )

array_push -- Push one or more elements onto the end of array

array array_reverse ( array array [, bool preserve_keys])

array_reverse() takes input array and returns a new array with the order of the elements reversed, preserving the keys if preserve_keys is TRUE.

Example 1. array_reverse() example
$input = array ("php", 4.0, array ("green", "red")); $result = array_reverse ($input); $result_keyed = array_reverse ($input, TRUE);
This makes both $result and $result_keyed have the same elements, but note the difference between the keys. The printout of $result and $result_keyed will be:
Array ( [0] => Array ( [0] => green [1] => red ) [1] => 4 [2] => php ) Array ( [2] => Array ( [0] => green [1] => red ) [1] => 4 [0] => php )

Note: The second parameter was added in PHP 4.0.3.

array_search

(PHP 4 >= 4.0.5)

array_search -- Searches the array for a given value and returns the corresponding key if successful

Description

mixed array_search ( mixed needle, array haystack [, bool strict])

Searches haystack for needle and returns the key if it is found in the array, FALSE otherwise.

Note: Prior to PHP 4.2.0, array_search() returns NULL on failure instead of FALSE.

If the optional third parameter strict is set to TRUE then the array_search() will also check the types of the needle in the haystack.

Warning

See also array_keys() and in_array().

array_shift

(PHP 4 )

array_shift -- Shift an element off the beginning of array

Description

mixed array_shift ( array array)

array_shift() shifts the first value of the array off and returns it, shortening the array by one element and moving everything down. All numerical array keys will be modified to start counting from zero while literal keys won't be touched. If array is empty (or is not an array), NULL will be returned.

Example 1. array_shift() example
$stack = array ("orange", "banana", "apple", "raspberry"); $fruit = array_shift ($stack);
This would result in $stack having 3 elements left:
Array ( [0] => banana [1] => apple [2] => raspberry )
and orange will be assigned to $fruit.

array_slice

(PHP 4 )

array_slice -- Extract a slice of the array

Description

array array_slice ( array array, int offset [, int length])

array_slice() returns the sequence of elements from the array array as specified by the offset and length parameters.

If offset is positive, the sequence will start at that offset in the array. If offset is negative, the sequence will start that far from the end of the array.

If length is given and is positive, then the sequence will have that many elements in it. If length is given and is negative then the sequence will stop that many elements from the end of the array. If it is omitted, then the sequence will have everything from offset up until the end of the array.

Note that array_slice() will ignore array keys, and will calculate offsets and lengths based on the actual positions of elements within the array.

Example 1. array_slice() examples
$input = array ("a", "b", "c", "d", "e"); $output = array_slice ($input, 2); // returns "c", "d", and "e" $output = array_slice ($input, 2, -1); // returns "c", "d" $output = array_slice ($input, -2, 1); // returns "d" $output = array_slice ($input, 0, 3); // returns "a", "b", and "c"

array_splice

(PHP 4 )

array_splice -- Remove a portion of the array and replace it with something else

Description

array array_splice ( array input, int offset [, int length [, array replacement]])

array_splice() removes the elements designated by offset and length from the input array, and replaces them with the elements of the replacement array, if supplied. It returns an array containing the extracted elements.

If offset is positive then the start of removed portion is at that offset from the beginning of the input array. If offset is negative then it starts that far from the end of the input array.

If length is omitted, removes everything from offset to the end of the array. If length is specified and is positive, then that many elements will be removed. If length is specified and is negative then the end of the removed portion will be that many elements from the end of the array. Tip: to remove everything from offset to the end of the array when replacement is also specified, use count($input) for length.

If replacement array is specified, then the removed elements are replaced with elements from this array. If offset and length are such that nothing is removed, then the elements from the replacement array are inserted in the place specified by the offset. Tip: if the replacement is just one element it is not necessary to put array() around it, unless the element is an array itself.

The following equivalences hold:
array_push ($input, $x, $y) array_splice ($input, count ($input), 0, array ($x, $y)) array_pop ($input) array_splice ($input, -1) array_shift ($input) array_splice ($input, 0, 1) array_unshift ($input, $x, $y) array_splice ($input, 0, 0, array ($x, $y)) $input[$x] = $y array_splice ($input, $x, 1, $y)

Returns the array consisting of removed elements.

Example 1. array_splice() examples
$input = array ("red", "green", "blue", "yellow"); array_splice ($input, 2); // $input is now array ("red", "green") $input = array ("red", "green", "blue", "yellow"); array_splice ($input, 1, -1); // $input is now array ("red", "yellow") $input = array ("red", "green", "blue", "yellow"); array_splice ($input, 1, count($input), "orange"); // $input is now array ("red", "orange") $input = array ("red", "green", "blue", "yellow"); array_splice ($input, -1, 1, array("black", "maroon")); // $input is now array ("red", "green", // "blue", "black", "maroon")

array_sum

(PHP 4 >= 4.0.4)

array_sum -- Calculate the sum of values in an array.

Description

mixed array_sum ( array array)

array_sum() returns the sum of values in an array as an integer or float.

Example 1. array_sum() examples
$a = array(2, 4, 6, 8); echo "sum(a) = ".array_sum($a)."\n"; $b = array("a"=>1.2,"b"=>2.3,"c"=>3.4); echo "sum(b) = ".array_sum($b)."\n";
The printout of the program above will be:
sum(a) = 20 sum(b) = 6.9

Note: PHP versions prior to 4.0.6 modified the passed array itself and converted strings to numbers (which most of the time converted them to zero, depending on their value).

array_unique

(PHP 4 >= 4.0.1)

array_unique -- Removes duplicate values from an array

Description

array array_unique ( array array)

array_unique() takes input array and returns a new array without duplicate values.

Note that keys are preserved. array_unique() sorts the values treated as string at first, then will keep the first key encountered for every value, and ignore all following keys. It does not mean that the key of the first related value from the unsorted array will be kept.

Note: Two elements are considered equal if and only if (string) $elem1 === (string) $elem2. In words: when the string representation is the same.
The first element will be used.

int array_walk ( array array, string func [, mixed userdata])

Applies the user-defined function func to each element of the array array. Typically, func takes on two parameters. The array parameter's value being the first, and the key/index second. If the optional userdata parameter is supplied, it will be passed as the third parameter to function func.

func must be a user-defined function, not a built-in PHP function such as strtolower() or stripslashes(). The user-defined function can use built-in PHP functions.

Note: Instead of a function name, an array containing an object reference and a method name can also be supplied.

If function func requires more parameters than given to it, an error of level E_WARNING will be generated each time array_walk() calls func. These warnings may be suppressed by prepending the PHP error operator @ to the array_walk() call, or by using error_reporting().

Note: If func needs to be working with the actual values of the array, specify the first parameter of func as a reference. Then, any changes made to those elements will be made in the original array itself.

Note: Passing the key and userdata to func was added in 4.0.0

array_walk() is not affected by the internal array pointer of array. array_walk() will walk through the entire array regardless of pointer position. To reset the pointer, use reset(). In PHP 3, array_walk() resets the pointer.

Users may not change the array itself from the callback function. e.g. Add/delete elements, unset elements, etc. If the array that array_walk() is applied to is changed, the behavior of this function is undefined, and unpredictable.

Example 1. array_walk() example
<?php $fruits = array ("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple"); function test_alter (&$item1, $key, $prefix) { $item1 = "$prefix: $item1"; } function test_print ($item2, $key) { echo "$key. $item2<br>\n"; } echo "Before ...:\n"; array_walk ($fruits, 'test_print'); array_walk ($fruits, 'test_alter', 'fruit'); echo "... and after:\n"; array_walk ($fruits, 'test_print'); ?>
The printout of the program above will be:
Before ...: d. lemon a. orange b. banana c. apple ... and after: d. fruit: lemon a. fruit: orange b. fruit: banana c. fruit: apple

array

(PHP 3, PHP 4 )

array -- Create an array

Description

array array ( [mixed ...])

Returns an array of the parameters. The parameters can be given an index with the => operator.

Note: array() is a language construct used to represent literal arrays, and not a regular function.

Syntax "index => values", separated by commas, define index and values. index may be of type string or numeric. When index is omitted, a integer index is automatically generated, starting at 0. If index is an integer, next generated index will be the biggest integer index + 1. Note that when two identical index are defined, the last overwrite the first.

The following example demonstrates how to create a two-dimensional array, how to specify keys for associative arrays, and how to skip-and-continue numeric indices in normal arrays.
Example 1. array() example
$fruits = array ( "fruits" => array ("a"=>"orange", "b"=>"banana", "c"=>"apple"), "numbers" => array (1, 2, 3, 4, 5, 6), "holes" => array ("first", 5 => "second", "third") );

Example 2. Automatic index with array()
$array = array( 1, 1, 1, 1, 1, 8=>1, 4=>1, 19, 3=>13); print_r($array);
will display :
Array ( [0] => 1 [1] => 1 [2] => 1 [3] => 13 [4] => 1 [8] => 1 [9] => 19 )

Note that index '3' is defined twice, and keep its final value of 13. Index 4 is defined after index 8, and next generated index (value 19) is 9, since biggest index was 8.

This example creates a 1-based array.
Example 3. 1-based index with array()
$firstquarter = array(1 => 'January', 'February', 'March'); print_r($firstquarter);
will display :
Array ( [1] => 'January' [2] => 'February' [3] => 'March' )

See also array_pad(), list(), and range().

arsort

(PHP 3, PHP 4 )

arsort -- Sort an array in reverse order and maintain index association

Description

void arsort ( array array [, int sort_flags])

This function sorts an array such that array indices maintain their correlation with the array elements they are associated with. This is used mainly when sorting associative arrays where the actual element order is significant.

Example 1. arsort() example

$fruits = array ("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple");
arsort ($fruits);
reset ($fruits);
while (list ($key, $val) = each ($fruits)) {
    echo "$key = $val\n";
}

This example would display:
a = orange d = lemon b = banana c = apple

The fruits have been sorted in reverse alphabetical order, and the index associated with each element has been maintained.

You may modify the behavior of the sort using the optional parameter sort_flags, for details see sort().

See also asort(), rsort(), ksort(), and sort().

asort

(PHP 3, PHP 4 )

asort -- Sort an array and maintain index association

Description

void asort ( array array [, int sort_flags])

Example 1. asort() example

$fruits = array ("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple");
asort ($fruits);
reset ($fruits);
while (list ($key, $val) = each ($fruits)) {
    echo "$key = $val\n";
}

This example would display:
c = apple b = banana d = lemon a = orange

The fruits have been sorted in alphabetical order, and the index associated with each element has been maintained.

You may modify the behavior of the sort using the optional parameter sort_flags, for details see sort().

See also arsort(), rsort(), ksort(), and sort().

compact

(PHP 4 )

compact -- Create array containing variables and their values

Description

array compact ( mixed varname [, mixed ...])

compact() takes a variable number of parameters. Each parameter can be either a string containing the name of the variable, or an array of variable names. The array can contain other arrays of variable names inside it; compact() handles it recursively.

For each of these, compact() looks for a variable with that name in the current symbol table and adds it to the output array such that the variable name becomes the key and the contents of the variable become the value for that key. In short, it does the opposite of extract(). It returns the output array with all the variables added to it.

Any strings that are not set will simply be skipped.

Example 1. compact() example
$city = "San Francisco"; $state = "CA"; $event = "SIGGRAPH"; $location_vars = array ("city", "state"); $result = compact ("event", "nothing_here", $location_vars);
After this, $result will be:
Array ( [event] => SIGGRAPH [city] => San Francisco [state] => CA )

count

(PHP 3, PHP 4 )

count -- Count elements in a variable

Description

int count ( mixed var)

Returns the number of elements in var, which is typically an array (since anything else will have one element).

If var is not an array, 1 will be returned (exception: count(NULL) equals 0).

Warning

count() may return 0 for a variable that isn't set, but it may also return 0 for a variable that has been initialized with an empty array. Use isset() to test if a variable is set.

Please see the Arrays section of the manual for a detailed explanation of how arrays are implemented and used in PHP.

Example 1. count() example
$a[0] = 1; $a[1] = 3; $a[2] = 5; $result = count ($a); // $result == 3 $b[0] = 7; $b[5] = 9; $b[10] = 11; $result = count ($b); // $result == 3;

Note: The sizeof() function is an alias for count().

See also is_array(), isset(), and strlen().

current

(PHP 3, PHP 4 )

current -- Return the current element in an array

Description

mixed current ( array array)

Every array has an internal pointer to its "current" element, which is initialized to the first element inserted into the array.

The current() function simply returns the array element that's currently being pointed by the internal pointer. It does not move the pointer in any way. If the internal pointer points beyond the end of the elements list, current() returns FALSE.

Warning

If the array contains empty elements (0 or "", the empty string) then this function will return FALSE for these elements as well. This makes it impossible to determine if you are really at the end of the list in such an array using current(). To properly traverse an array that may contain empty elements, use the each() function.

See also end(), next(), prev(), and reset().

each

(PHP 3, PHP 4 )

each -- Return the current key and value pair from an array and advance the array cursor

Description

array each ( array array)

Returns the current key and value pair from the array array and advances the array cursor. This pair is returned in a four-element array, with the keys 0, 1, key, and value. Elements 0 and key contain the key name of the array element, and 1 and value contain the data.

If the internal pointer for the array points past the end of the array contents, each() returns FALSE.

Example 1. each() examples
$foo = array ("bob", "fred", "jussi", "jouni", "egon", "marliese"); $bar = each ($foo);
$bar now contains the following key/value pairs:
0 => 0
1 => 'bob'
key => 0
value => 'bob'

$foo = array ("Robert" => "Bob", "Seppo" => "Sepi"); $bar = each ($foo);

$bar now contains the following key/value pairs:
0 => 'Robert'
1 => 'Bob'
key => 'Robert'
value => 'Bob'

each() is typically used in conjunction with list() to traverse an array; for instance, $_POST:
Example 2. Traversing $_POST with each()
echo "Values submitted via POST method:<br />\n"; reset ($_POST); while (list ($key, $val) = each ($_POST)) { echo "$key => $val<br />\n"; }

After each() has executed, the array cursor will be left on the next element of the array, or on the last element if it hits the end of the array. You have to use reset() if you want to traverse the array again using each.

See also key(), list(), current(), reset(), next(), prev(), and foreach().

end

(PHP 3, PHP 4 )

end -- Set the internal pointer of an array to its last element

Description

mixed end ( array array)

end() advances array's internal pointer to the last element, and returns that element.

Example 1. A simple end() example
<?php $fruits = array('apple','banana','cranberry'); print end($fruits); // cranberry ?>

See also current(), each(), next(), and reset().

extract

(PHP 3>= 3.0.7, PHP 4 )

extract -- Import variables into the current symbol table from an array

Description

int extract ( array var_array [, int extract_type [, string prefix]])

This function is used to import variables from an array into the current symbol table. It takes an associative array var_array and treats keys as variable names and values as variable values. For each key/value pair it will create a variable in the current symbol table, subject to extract_type and prefix parameters.

Note: Beginning with version 4.0.5, this function returns the number of variables extracted.

Note: EXTR_IF_EXISTS and EXTR_PREFIX_IF_EXISTS was introduced in version 4.2.0.

Note: EXTR_REFS was introduced in version 4.3.0.

extract() checks each key to see whether it has a valid variable name. It also checks for collisions with existing variables in the symbol table. The way invalid/numeric keys and collisions are treated is determined by the extract_type. It can be one of the following values:

EXTR_OVERWRITE: If there is a collision, overwrite the existing variable.
EXTR_SKIP: If there is a collision, don't overwrite the existing variable.
EXTR_PREFIX_SAME: If there is a collision, prefix the variable name with prefix.
EXTR_PREFIX_ALL: Prefix all variable names with prefix. Beginning with PHP 4.0.5, this includes numeric variables as well.
EXTR_PREFIX_INVALID: Only prefix invalid/numeric variable names with prefix. This flag was added in PHP 4.0.5.
EXTR_IF_EXISTS: Only overwrite the variable if it already exists in the current symbol table, otherwise do nothing. This is useful for defining a list of valid variables and then extracting only those variables you have defined out of $_REQUEST, for example. This flag was added in PHP 4.2.0.
EXTR_PREFIX_IF_EXISTS: Only create prefixed variable names if the non-prefixed version of the same variable exists in the current symbol table. This flag was added in PHP 4.2.0.
EXTR_REFS: Extracts variables as references. This effectively means that the values of the imported variables are still referencing the values of the var_array parameter. You can use this flag on its own or combine it with any other flag by OR'ing the extract_type. This flag was added in PHP 4.3.0.

If extract_type is not specified, it is assumed to be EXTR_OVERWRITE.

Note that prefix is only required if extract_type is EXTR_PREFIX_SAME, EXTR_PREFIX_ALL, EXTR_PREFIX_INVALID or EXTR_PREFIX_IF_EXISTS. If the prefixed result is not a valid variable name, it is not imported into the symbol table.

extract() returns the number of variables successfully imported into the symbol table.

A possible use for extract is to import into the symbol table variables contained in an associative array returned by wddx_deserialize().

Example 1. extract() example
<?php /* Suppose that $var_array is an array returned from wddx_deserialize */ $size = "large"; $var_array = array ("color" => "blue", "size" => "medium", "shape" => "sphere"); extract ($var_array, EXTR_PREFIX_SAME, "wddx"); print "$color, $size, $shape, $wddx_size\n"; ?>

The above example will produce:
blue, large, sphere, medium

The $size wasn't overwritten, because we specified EXTR_PREFIX_SAME, which resulted in $wddx_size being created. If EXTR_SKIP was specified, then $wddx_size wouldn't even have been created. EXTR_OVERWRITE would have caused $size to have value "medium", and EXTR_PREFIX_ALL would result in new variables being named $wddx_color, $wddx_size, and $wddx_shape.

You must use an associative array, a numerically indexed array will not produce results unless you use EXTR_PREFIX_ALL or EXTR_PREFIX_INVALID.

in_array

(PHP 4 )

in_array -- Return TRUE if a value exists in an array

Description

bool in_array ( mixed needle, array haystack [, bool strict])

Searches haystack for needle and returns TRUE if it is found in the array, FALSE otherwise.

If the third parameter strict is set to TRUE then the in_array() function will also check the types of the needle in the haystack.

Note: If needle is a string, the comparison is done in a case-sensitive manner.

Note: In PHP versions before 4.2.0 needle was not allowed to be an array.

Example 1. in_array() example
$os = array ("Mac", "NT", "Irix", "Linux"); if (in_array ("Irix", $os)) { print "Got Irix"; } if (in_array ("mac", $os)) { print "Got mac"; }
The second condition fails because in_array() is case-sensitive, so the program above will display:
Got Irix

Example 2. in_array() with strict example
<?php $a = array('1.10', 12.4, 1.13); if (in_array('12.4', $a, TRUE)) echo "'12.4' found with strict check\n"; if (in_array(1.13, $a, TRUE)) echo "1.13 found with strict check\n"; ?>
This will display:
1.13 found with strict check

Example 3. in_array() with an array as needle
<?php $a = array(array('p', 'h'), array('p', 'r'), 'o'); if (in_array(array ('p', 'h'), $a)) echo "'ph' was found\n"; if (in_array(array ('f', 'i'), $a)) echo "'fi' was found\n"; if (in_array('o', $a)) echo "'o' was found\n"; ?> // This will output: 'ph' was found 'o' was found

key

(PHP 3, PHP 4 )

key -- Fetch a key from an associative array

Description

mixed key ( array array)

key() returns the index element of the current array position.

krsort

(PHP 3>= 3.0.13, PHP 4 )

krsort -- Sort an array by key in reverse order

Description

int krsort ( array array [, int sort_flags])

Sorts an array by key in reverse order, maintaining key to data correlations. This is useful mainly for associative arrays.
Example 1. krsort() example
$fruits = array ("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple"); krsort ($fruits); reset ($fruits); while (list ($key, $val) = each ($fruits)) { echo "$key = $val\n"; }

This example would display:

d = lemon c = apple b = banana a = orange

You may modify the behavior of the sort using the optional parameter sort_flags, for details see sort().

ksort

(PHP 3, PHP 4 )

ksort -- Sort an array by key

Description

int ksort ( array array [, int sort_flags])

Sorts an array by key, maintaining key to data correlations. This is useful mainly for associative arrays.
Example 1. ksort() example
$fruits = array ("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple"); ksort ($fruits); reset ($fruits); while (list ($key, $val) = each ($fruits)) { echo "$key = $val\n"; }

This example would display:

a = orange b = banana c = apple d = lemon

You may modify the behavior of the sort using the optional parameter sort_flags, for details see sort().

Note: The second parameter was added in PHP 4.

list

(PHP 3, PHP 4 )

list -- Assign variables as if they were an array

Description

void list ( mixed ...)

Like array(), this is not really a function, but a language construct. list() is used to assign a list of variables in one operation.

Note: list() only works on numerical arrays and assumes the numerical indices start at 0.

Example 1. list() examples
<?php $info = array('coffee', 'brown', 'caffeine'); // Listing all the variables list($drink, $color, $power) = $info; print "$drink is $color and $power makes it special.\n"; // Listing some of them list($drink, , $power) = $info; print "$drink has $power.\n"; // Or let's skip to only the third one list( , , $power) = $info; print "I need $power!\n"; ?>

Example 2. An example use of list()
<table> <tr> <th>Employee name</th> <th>Salary</th> </tr> <?php $result = mysql_query ("SELECT id, name, salary FROM employees",$conn); while (list ($id, $name, $salary) = mysql_fetch_row ($result)) { print (" <tr>\n". " <td><a href=\"info.php?id=$id\">$name</a></td>\n". " <td>$salary</td>\n". " </tr>\n"); } ?> </table>

Warning

list() assigns the values starting with the right-most parameter. If you are using plain variables, you don't have to worry about this. But if you are using arrays with indices you usually expect the order of the indices in the array the same you wrote in the list() from left to right; which it isn't. It's assigned in the reverse order.

Example 3. Using list() with array indices
<?php $info = array('coffee', 'brown', 'caffeine'); list($a[0], $a[1], $a[2]) = $info; var_dump($a); ?>
Gives the following output (note the order of the elements compared in which order they were written in the list() syntax):
array(3) { [2]=> string(8) "caffeine" [1]=> string(5) "brown" [0]=> string(6) "coffee" }

See also each(), array() and extract().

natcasesort

(PHP 4 )

natcasesort -- Sort an array using a case insensitive "natural order" algorithm

Description

void natcasesort ( array array)

This function implements a sort algorithm that orders alphanumeric strings in the way a human being would. This is described as a "natural ordering".

natcasesort() is a case insensitive version of natsort(). See natsort() for an example of the difference between this algorithm and the regular computer string sorting algorithms.

For more information see: Martin Pool's Natural Order String Comparison page.

natsort

(PHP 4 )

natsort -- Sort an array using a "natural order" algorithm

Description

void natsort ( array array)

This function implements a sort algorithm that orders alphanumeric strings in the way a human being would. This is described as a "natural ordering". An example of the difference between this algorithm and the regular computer string sorting algorithms (used in sort()) can be seen below:

Example 1. natsort() example
<?php $array1 = $array2 = array ("img12.png", "img10.png", "img2.png", "img1.png"); sort($array1); echo "Standard sorting\n"; print_r($array1); natsort($array2); echo "\nNatural order sorting\n"; print_r($array2); ?>

The code above will generate the following output:

Standard sorting Array ( [0] => img1.png [1] => img10.png [2] => img12.png [3] => img2.png ) Natural order sorting Array ( [3] => img1.png [2] => img2.png [1] => img10.png [0] => img12.png )
For more information see: Martin Pool's Natural Order String Comparison page.

Note: If you're wanting to maintain index/value associations, consider using usort($arr, 'strnatcmp').

(PHP 3, PHP 4 )

next -- Advance the internal array pointer of an array

Description

mixed next ( array array)

Returns the array element in the next place that's pointed by the internal array pointer, or FALSE if there are no more elements.

next() behaves like current(), with one difference. It advances the internal array pointer one place forward before returning the element. That means it returns the next array element and advances the internal array pointer by one. If advancing the internal array pointer results in going beyond the end of the element list, next() returns FALSE.

Warning

If the array contains empty elements, or elements that have a key value of 0 then this function will return FALSE for these elements as well. To properly traverse an array which may contain empty elements or elements with key values of 0 see the each() function.

See also current(), end(), prev(), and reset().

pos

(PHP 3, PHP 4 )

pos -- Get the current element from an array

Description

mixed pos ( array array)

This is an alias for current().

See also end(), next(), prev(), and reset().

(PHP 3, PHP 4 )

prev -- Rewind the internal array pointer

Description

mixed prev ( array array)

Returns the array element in the previous place that's pointed by the internal array pointer, or FALSE if there are no more elements.

Warning

If the array contains empty elements then this function will return FALSE for these elements as well. To properly traverse an array which may contain empty elements see the each() function.

prev() behaves just like next(), except it rewinds the internal array pointer one place instead of advancing it.

See also current(), end(), next(), and reset().

range

(PHP 3>= 3.0.8, PHP 4 )

range -- Create an array containing a range of elements

Description

array range ( mixed low, mixed high)

range() returns an array of elements from low to high, inclusive. If low > high, the sequence will be from high to low.

Example 1. range() examples

foreach(range(0, 9) as $number) {
    echo $number;
}
foreach(range('a', 'z') as $letter) {
    echo $letter;
}
foreach(range('z', 'a') as $letter) {
    echo $letter;
}

Note: Prior to version 4.1.0 the range() function only generated incrementing integer arrays. Support for character sequences and decrementing arrays was added in 4.1.0.
Example 2. Simulating decrementing ranges and character sequences
# array_reverse can be used to flip the order of a range
foreach(array_reverse(range(0,9)) as $number) {
    echo $number;
}

# array_map() can be used to turn integers into characters using chr()
foreach(array_map('chr', range(ord('a'),ord('z'))) as $character) {
    echo $character;
}

See shuffle() for another example of its use.

reset

(PHP 3, PHP 4 )

reset -- Set the internal pointer of an array to its first element

Description

mixed reset ( array array)

reset() rewinds array's internal pointer to the first element.

reset() returns the value of the first array element.

See also current(), each(), next(), and prev().

rsort

(PHP 3, PHP 4 )

rsort -- Sort an array in reverse order

Description

void rsort ( array array [, int sort_flags])

This function sorts an array in reverse order (highest to lowest).
Example 1. rsort() example
$fruits = array ("lemon", "orange", "banana", "apple"); rsort ($fruits); reset ($fruits); while (list ($key, $val) = each ($fruits)) { echo "$key = $val\n"; }

This example would display:

0 = orange 1 = lemon 2 = banana 3 = apple

void sort ( array array [, int sort_flags])

This function sorts an array. Elements will be arranged from lowest to highest when this function has completed.
Example 1. sort() example
<?php $fruits = array ("lemon", "orange", "banana", "apple"); sort ($fruits); reset ($fruits); while (list ($key, $val) = each ($fruits)) { echo "fruits[".$key."] = ".$val."\n"; } ?>

This example would display:

fruits[0] = apple fruits[1] = banana fruits[2] = lemon fruits[3] = orange

The fruits have been sorted in alphabetical order.

The optional second parameter sort_flags may be used to modify the sorting behavior using these values:

Sorting type flags:

SORT_REGULAR - compare items normally
SORT_NUMERIC - compare items numerically
SORT_STRING - compare items as strings

Note: The second parameter was added in PHP 4.

uasort

(PHP 3>= 3.0.4, PHP 4 )

uasort -- Sort an array with a user-defined comparison function and maintain index association

Description

void uasort ( array array, function cmp_function)

Note: Please see usort() and uksort() for examples of user-defined comparison functions.

Note: Instead of a function name, an array containing an object reference and a method name can also be supplied.

uksort

(PHP 3>= 3.0.4, PHP 4 )

uksort -- Sort an array by keys using a user-defined comparison function

Description

void uksort ( array array, function cmp_function)

This function will sort the keys of an array using a user-supplied comparison function. If the array you wish to sort needs to be sorted by some non-trivial criteria, you should use this function.

Example 1. uksort() example

function cmp ($a, $b) {
    if ($a == $b) return 0;
    return ($a > $b) ? -1 : 1;
}

$a = array (4 => "four", 3 => "three", 20 => "twenty", 10 => "ten");

uksort ($a, "cmp");

while (list ($key, $value) = each ($a)) {
    echo "$key: $value\n";
}

This example would display:

20: twenty 10: ten 4: four 3: three

Note: Instead of a function name, an array containing an object reference and a method name can also be supplied.

usort

(PHP 3>= 3.0.3, PHP 4 )

usort -- Sort an array by values using a user-defined comparison function

Description

void usort ( array array, string cmp_function)

This function will sort an array by its values using a user-supplied comparison function. If the array you wish to sort needs to be sorted by some non-trivial criteria, you should use this function.

The comparison function must return an integer less than, equal to, or greater than zero if the first argument is considered to be respectively less than, equal to, or greater than the second.

Note: If two members compare as equal, their order in the sorted array is undefined. Up to PHP 4.0.6 the user defined functions would keep the original order for those elements, but with the new sort algorithm intruduced with 4.1.0 this is no longer the case as there is no solution to do so in an efficient way.

Example 1. usort() example
function cmp ($a, $b) { if ($a == $b) return 0; return ($a > $b) ? -1 : 1; } $a = array (3, 2, 5, 6, 1); usort ($a, "cmp"); while (list ($key, $value) = each ($a)) { echo "$key: $value\n"; }

This example would display:

0: 6 1: 5 2: 3 3: 2 4: 1

Note: Obviously in this trivial case the rsort() function would be more appropriate.

Example 2. usort() example using multi-dimensional array
function cmp ($a, $b) { return strcmp($a["fruit"], $b["fruit"]); } $fruits[0]["fruit"] = "lemons"; $fruits[1]["fruit"] = "apples"; $fruits[2]["fruit"] = "grapes"; usort($fruits, "cmp"); while (list ($key, $value) = each ($fruits)) { echo "\$fruits[$key]: " . $value["fruit"] . "\n"; }

When sorting a multi-dimensional array, $a and $b contain references to the first index of the array.

This example would display:

$fruits[0]: apples $fruits[1]: grapes $fruits[2]: lemons

Note: Instead of a function name, an array containing an object reference and a method name can also be supplied.

Example 3. usort() example using a member function of an object
class TestObj { var $name; function TestObj($name) { $this->name = $name; } /* This is the static comparing function: */ function cmp_obj($a, $b) { $al = strtolower($a->name); $bl = strtolower($b->name); if ($al == $bl) return 0; return ($al > $bl) ? +1 : -1; } } $a[] = new TestObj("c"); $a[] = new TestObj("b"); $a[] = new TestObj("d"); uasort($a, array ("TestObj", "cmp_obj")); foreach ($a as $item) { print $item->name."\n"; }

This example would display:

b c d

Warning

The underlying quicksort function in some C libraries (such as on Solaris systems) may cause PHP to crash if the comparison function does not return consistent values.

III. Aspell functions [deprecated]

Introduction

aspell_suggest -- Suggest spellings of a word [deprecated]

Description

array aspell_suggest ( int dictionary_link, string word)

aspell_suggest() returns an array of possible spellings for the given word.

Example 1. aspell_suggest()
$aspell_link = aspell_new("english"); if (!aspell_check($aspell_link, "test")) { $suggestions = aspell_suggest($aspell_link, "test"); foreach ($suggestions as $suggestion) { echo "Possible spelling: $suggestion<br>\n"; } }

IV. BCMath Arbitrary Precision Mathematics Functions

Introduction

For arbitrary precision mathematics PHP offers the Binary Calculator which supports numbers of any size and precision, represented as strings.

Requirements

Since PHP 4.0.4, libbcmath is bundled with PHP. You don't need any external libraries for this extension.

Installation

In PHP 4, these functions are only available if PHP was configured with --enable-bcmath. In PHP 3, these functions are only available if PHP was not configured with --disable-bcmath.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. BC math configuration options

Name	Default	Changeable
bcmath.scale	0	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Here is a short explanation of the configuration directives.

bcmath.scale integer: Number of decimal digits for all bcmath functions.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Table of Contents
bcadd -- Add two arbitrary precision numbers
bccomp -- Compare two arbitrary precision numbers
bcdiv -- Divide two arbitrary precision numbers
bcmod -- Get modulus of an arbitrary precision number
bcmul -- Multiply two arbitrary precision number
bcpow -- Raise an arbitrary precision number to another
bcscale -- Set default scale parameter for all bc math functions
bcsqrt -- Get the square root of an arbitrary precision number
bcsub -- Subtract one arbitrary precision number from another

V. Bzip2 Compression Functions

Introduction

The bzip2 functions are used to transparently read and write bzip2 (.bz2) compressed files.

Requirements

This module uses the functions of the bzip2 library by Julian Seward

Installation

Bzip2 support in PHP is not enabled by default. You will need to use the --with-bz2 configuration option when compiling PHP to enable bzip2 support. This module requires bzip2/libbzip2 version >= 1.0.x.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension defines one resource type: a file pointer identifying the bz2-file to work on.

Predefined Constants

This extension has no constants defined.

Examples

This example opens a temporary file and writes a test string to it, then prints out the contents of the file.

Example 1. Small bzip2 Example

<?php

$filename = "/tmp/testfile.bz2";
$str = "This is a test string.\n";

// open file for writing
$bz = bzopen($filename, "w");

// write string to file
bzwrite($bz, $str);

// close file
bzclose($bz);

// open file for reading
$bz = bzopen($filename, "r");

// read 10 characters
print bzread($bz, 10);

// output until end of the file (or the next 1024 char) and close it.  
print bzread($bz);

bzclose($bz);

?>

Table of Contents
bzclose -- Close a bzip2 file pointer
bzcompress -- Compress a string into bzip2 encoded data
bzdecompress -- Decompresses bzip2 encoded data
bzerrno -- Returns a bzip2 error number
bzerror -- Returns the bzip2 error number and error string in an array
bzerrstr -- Returns a bzip2 error string
bzflush -- Force a write of all buffered data
bzopen -- Open a bzip2 compressed file
bzread -- Binary safe bzip2 file read
bzwrite -- Binary safe bzip2 file write

bzclose

(PHP 4 >= 4.0.4)

bzclose -- Close a bzip2 file pointer

Description

int bzclose ( resource bz)

Closes the bzip2 file referenced by the pointer bz.

Returns TRUE on success or FALSE on failure.

The file pointer must be valid, and must point to a file successfully opened by bzopen().

bzcompress

(PHP 4 >= 4.0.4)

bzcompress -- Compress a string into bzip2 encoded data

Description

string bzcompress ( string source [, int blocksize [, int workfactor]])

bzcompress() compresses the source string and returns it as bzip2 encoded data.

array bzerror ( resource bz)

Returns the error number and error string, in an associative array, of any bzip2 error returned by the file pointer bz.

Example 1. bzerror() Example
<?php $error = bzerror($bz); echo $error["errno"]; echo $error["errstr"]; ?>

See also bzerrno() and bzerrstr().

bzerrstr

(PHP 4 >= 4.0.4)

bzerrstr -- Returns a bzip2 error string

int bzwrite ( resource bz, string data [, int length])

bzwrite() writes the contents of the string data to the bzip2 file stream pointed to by bz. If the optional length argument is given, writing will stop after length (uncompressed) bytes have been written or the end of string is reached, whichever comes first.

Example 1. bzwrite() Example
<?php $str = "uncompressed data"; $bz = bzopen("/tmp/foo.bz2", "w"); bzwrite($bz, $str, strlen($str)); bzclose($bz); ?>

VI. Calendar functions

Introduction

The calendar extension presents a series of functions to simplify converting between different calendar formats. The intermediary or standard it is based on is the Julian Day Count. The Julian Day Count is a count of days starting from January 1st, 4713 B.C. To convert between calendar systems, you must first convert to Julian Day Count, then to the calendar system of your choice. Julian Day Count is very different from the Julian Calendar! For more information on Julian Day Count, visit http://serendipity.magnet.ch/hermetic/cal_stud/jdn.htm. For more information on calendar systems visit http://genealogy.org/~scottlee/cal-overview.html. Excerpts from this page are included in these instructions, and are in quotes.

Installation

To get these functions to work, you have to compile PHP with --enable-calendar.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

CAL_GREGORIAN (integer)
CAL_JULIAN (integer)
CAL_JEWISH (integer)
CAL_FRENCH (integer)
CAL_NUM_CALS (integer)
CAL_DOW_DAYNO (integer)
CAL_DOW_SHORT (integer)
CAL_DOW_LONG (integer)
CAL_MONTH_GREGORIAN_SHORT (integer)
CAL_MONTH_GREGORIAN_LONG (integer)
CAL_MONTH_JULIAN_SHORT (integer)
CAL_MONTH_JULIAN_LONG (integer)
CAL_MONTH_JEWISH (integer)
CAL_MONTH_FRENCH (integer)

The following constants are available since PHP 4.3.0 :

CAL_EASTER_DEFAULT (integer)
CAL_EASTER_ROMAN (integer)
CAL_EASTER_ALWAYS_GREGORIAN (integer)
CAL_EASTER_ALWAYS_JULIAN (integer)

Table of Contents
cal_days_in_month -- Return the number of days in a month for a given year and calendar
cal_from_jd -- Converts from Julian Day Count to a supported calendar and return extended information
cal_info -- Returns information about a particular calendar
cal_to_jd -- Converts from a supported calendar to Julian Day Count
easter_date -- Get UNIX timestamp for midnight on Easter of a given year
easter_days -- Get number of days after March 21 on which Easter falls for a given year
FrenchToJD -- Converts a date from the French Republican Calendar to a Julian Day Count
GregorianToJD -- Converts a Gregorian date to Julian Day Count
JDDayOfWeek -- Returns the day of the week
JDMonthName -- Returns a month name
JDToFrench -- Converts a Julian Day Count to the French Republican Calendar
JDToGregorian -- Converts Julian Day Count to Gregorian date
JDToJewish -- Converts a Julian Day Count to the Jewish Calendar
JDToJulian -- Converts a Julian Day Count to a Julian Calendar Date
jdtounix -- Convert Julian Day to UNIX timestamp
JewishToJD -- Converts a date in the Jewish Calendar to Julian Day Count
JulianToJD -- Converts a Julian Calendar date to Julian Day Count
unixtojd -- Convert UNIX timestamp to Julian Day

cal_days_in_month

(PHP 4 >= 4.1.0)

cal_days_in_month -- Return the number of days in a month for a given year and calendar

Description

int cal_days_in_month ( int calendar, int month, int year)

int easter_date ( [int year])

Returns the UNIX timestamp corresponding to midnight on Easter of the given year.

Since PHP 4.3.0, the year parameter is optional and defaults to the current year according to the localtime if ommited.

Warning: This function will generate a warning if the year is outside of the range for UNIX timestamps (i.e. before 1970 or after 2037).
Example 1. easter_date() example
echo date ("M-d-Y", easter_date(1999)); /* "Apr-04-1999" */ echo date ("M-d-Y", easter_date(2000)); /* "Apr-23-2000" */ echo date ("M-d-Y", easter_date(2001)); /* "Apr-15-2001" */

The date of Easter Day was defined by the Council of Nicaea in AD325 as the Sunday after the first full moon which falls on or after the Spring Equinox. The Equinox is assumed to always fall on 21st March, so the calculation reduces to determining the date of the full moon and the date of the following Sunday. The algorithm used here was introduced around the year 532 by Dionysius Exiguus. Under the Julian Calendar (for years before 1753) a simple 19-year cycle is used to track the phases of the Moon. Under the Gregorian Calendar (for years after 1753 - devised by Clavius and Lilius, and introduced by Pope Gregory XIII in October 1582, and into Britain and its then colonies in September 1752) two correction factors are added to make the cycle more accurate.

(The code is based on a C program by Simon Kershaw, <webmaster@ely.anglican.org>)

See easter_days() for calculating Easter before 1970 or after 2037.

easter_days

(PHP 3>= 3.0.9, PHP 4 )

easter_days -- Get number of days after March 21 on which Easter falls for a given year

Description

int easter_days ( [int year [, int method]])

Returns the number of days after March 21 on which Easter falls for a given year. If no year is specified, the current year is assumed.

Since PHP 4.3.0, the year parameter is optional and defaults to the current year according to the localtime if ommited.

mixed jddayofweek ( int julianday, int mode)

Returns the day of the week. Can return a string or an integer depending on the mode.

Table 1. Calendar week modes

Mode	Meaning
0	Returns the day number as an int (0=sunday, 1=monday, etc)
1	Returns string containing the day of week (english-gregorian)
2	Returns a string containing the abbreviated day of week (english-gregorian)

JDMonthName

(PHP 3, PHP 4 )

JDMonthName -- Returns a month name

Description

string jdmonthname ( int julianday, int mode)

Returns a string containing a month name. mode tells this function which calendar to convert the Julian Day Count to, and what type of month names are to be returned.

Table 1. Calendar modes

Mode	Meaning	Values
0	Gregorian - abbreviated	Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec
1	Gregorian	January, February, March, April, May, June, July, August, September, October, November, December
2	Julian - abbreviated	Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec
3	Julian	January, February, March, April, May, June, July, August, September, October, November, December
4	Jewish	Tishri, Heshvan, Kislev, Tevet, Shevat, AdarI, AdarII, Nisan, Iyyar, Sivan, Tammuz, Av, Elul
5	French Republican	Vendemiaire, Brumaire, Frimaire, Nivose, Pluviose, Ventose, Germinal, Floreal, Prairial, Messidor, Thermidor, Fructidor, Extra

Note: CCVS has been discontinued by Red Hat and there are no plans to issue further keys or support contracts. Those looking for a replacement can consider MCVE by Main Street Softworks as a potential replacement. It is similar in design and has documented PHP support!

string ccvs_void ( string session, string invoice)

Warning

This function is currently not documented; only the argument list is available.

VIII. COM support functions for Windows

Introduction

COM is a technology which allows the reuse of code written in any language (by any language) using a standard calling convention and hiding behind APIs the implementation details such as what machine the Component is stored on and the executable which houses it. It can be thought of as a super Remote Procedure Call (RPC) mechanism with some basic object roots. It separates implementation from interface.

COM encourages versioning, separation of implementation from interface and hiding the implementation details such as executable location and the language it was written in.

Requirements

COM functions are only available on the Windows version of PHP.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Com configuration options

Name	Default	Changeable
com.allow_dcom	"0"	PHP_INI_SYSTEM
com.autoregister_typelib	"0"	PHP_INI_SYSTEM
com.autoregister_verbose	"0"	PHP_INI_SYSTEM
com.autoregister_casesensitive	"1"	PHP_INI_SYSTEM
com.typelib_file	""	PHP_INI_SYSTEM

For further details and definition of the PHP_INI_* constants see ini_set().

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

CLSCTX_INPROC_SERVER (integer)
CLSCTX_INPROC_HANDLER (integer)
CLSCTX_LOCAL_SERVER (integer)
CLSCTX_REMOTE_SERVER (integer)
CLSCTX_SERVER (integer)
CLSCTX_ALL (integer)
VT_NULL (integer)
VT_EMPTY (integer)
VT_UI1 (integer)
VT_I2 (integer)
VT_I4 (integer)
VT_R4 (integer)
VT_R8 (integer)
VT_BOOL (integer)
VT_ERROR (integer)
VT_CY (integer)
VT_DATE (integer)
VT_BSTR (integer)
VT_DECIMAL (integer)
VT_UNKNOWN (integer)
VT_DISPATCH (integer)
VT_VARIANT (integer)
VT_I1 (integer)
VT_UI2 (integer)
VT_UI4 (integer)
VT_INT (integer)
VT_UINT (integer)
VT_ARRAY (integer)
VT_BYREF (integer)
CP_ACP (integer)
CP_MACCP (integer)
CP_OEMCP (integer)
CP_UTF7 (integer)
CP_UTF8 (integer)
CP_SYMBOL (integer)
CP_THREAD_ACP (integer)

COM

(no version information, might be only in CVS)

COM -- COM class

Synopsis

$obj = new COM("server.object")

Description

The COM class provides a framework to integrate (D)COM components into your php scripts.

Methods

string COM::COM ( string module_name [, string server_name [, int codepage]])

COM class constructor. Parameters:

module_name: name or class-id of the requested component.
server_name: name of the DCOM server from which the component should be fetched. If NULL, localhost is assumed. To allow DCOM com.allow_dcom has to be set to TRUE in php.ini.
codepage: specifies the codepage that is used to convert php-strings to unicode-strings and vice versa. Possible values are CP_ACP, CP_MACCP, CP_OEMCP, CP_SYMBOL, CP_THREAD_ACP, CP_UTF7 and CP_UTF8.

Example 1. COM example (1)
// starting word $word = new COM("word.application") or die("Unable to instanciate Word"); print "Loaded Word, version {$word->Version}\n"; //bring it to front $word->Visible = 1; //open an empty document $word->Documents->Add(); //do some weird stuff $word->Selection->TypeText("This is a test..."); $word->Documents[1]->SaveAs("Useless test.doc"); //closing word $word->Quit(); //free the object $word->Release(); $word = null;

Example 2. COM example (2)
$conn = new COM("ADODB.Connection") or die("Cannot start ADO"); $conn->Open("Provider=SQLOLEDB; Data Source=localhost; Initial Catalog=database; User ID=user; Password=password"); $rs = $conn->Execute("SELECT * FROM sometable"); // Recordset $num_columns = $rs->Fields->Count(); echo $num_columns . "\n"; for ($i=0; $i < $num_columns; $i++) { $fld[$i] = $rs->Fields($i); } $rowcount = 0; while (!$rs->EOF) { for ($i=0; $i < $num_columns; $i++) { echo $fld[$i]->value . "\t"; } echo "\n"; $rowcount++; // increments rowcount $rs->MoveNext(); } $rs->Close(); $conn->Close(); $rs->Release(); $conn->Release(); $rs = null; $conn = null;

VARIANT

(no version information, might be only in CVS)

VARIANT -- VARIANT class

Synopsis

$vVar = new VARIANT($var)

Description

A simple container to wrap variables into VARIANT structures.

Methods

string VARIANT::VARIANT ( [mixed value [, int type [, int codepage]]])

VARIANT class constructor. Parameters:

value: initial value. if omitted an VT_EMPTY object is created.
type: specifies the content type of the VARIANT object. Possible values are VT_UI1, VT_UI2, VT_UI4, VT_I1, VT_I2, VT_I4, VT_R4, VT_R8, VT_INT, VT_UINT, VT_BOOL, VT_ERROR, VT_CY, VT_DATE, VT_BSTR, VT_DECIMAL, VT_UNKNOWN, VT_DISPATCH and VT_VARIANT. These values are mutual exclusive, but they can be combined with VT_BYREF to specify being a value. If omitted, the type of value is used. Consult the msdn library for additional information.
codepage: specifies the codepage that is used to convert php-strings to unicode-strings and vice versa. Possible values are CP_ACP, CP_MACCP, CP_OEMCP, CP_SYMBOL, CP_THREAD_ACP, CP_UTF7 and CP_UTF8.

This function is currently not documented; only the argument list is available.

com_load_typelib

(PHP 4 >= 4.1.0)

com_load_typelib -- Loads a Typelib

Description

Description

void com_set ( resource com_object, string property, mixed value)

Sets the value of the property of the COM component referenced by com_object. Returns the newly set value if succeeded, FALSE on error.

IX. Class/Object Functions

Introduction

These functions allow you to obtain information about classes and instance objects. You can obtain the name of the class to which a object belongs, as well as its member properties and methods. Using these functions, you can find out not only the class membership of an object, but also its parentage (i.e. what class is the object class extending).

Examples

In this example, we first define a base class and an extension of the class. The base class describes a general vegetable, whether it is edible or not and what is its color. The subclass Spinach adds a method to cook it and another to find out if it is cooked.

Example 1. classes.inc
<?php // base class with member properties and methods class Vegetable { var $edible; var $color; function Vegetable( $edible, $color="green" ) { $this->edible = $edible; $this->color = $color; } function is_edible() { return $this->edible; } function what_color() { return $this->color; } } // end of class Vegetable // extends the base class class Spinach extends Vegetable { var $cooked = false; function Spinach() { $this->Vegetable( true, "green" ); } function cook_it() { $this->cooked = true; } function is_cooked() { return $this->cooked; } } // end of class Spinach ?>

We then instantiate 2 objects from these classes and print out information about them, including their class parentage. We also define some utility functions, mainly to have a nice printout of the variables.

Example 2. test_script.php
<pre> <?php include "classes.inc"; // utility functions function print_vars($obj) { $arr = get_object_vars($obj); while (list($prop, $val) = each($arr)) echo "\t$prop = $val\n"; } function print_methods($obj) { $arr = get_class_methods(get_class($obj)); foreach ($arr as $method) echo "\tfunction $method()\n"; } function class_parentage($obj, $class) { global $$obj; if (is_subclass_of($$obj, $class)) { echo "Object $obj belongs to class ".get_class($$obj); echo " a subclass of $class\n"; } else { echo "Object $obj does not belong to a subclass of $class\n"; } } // instantiate 2 objects $veggie = new Vegetable(true,"blue"); $leafy = new Spinach(); // print out information about objects echo "veggie: CLASS ".get_class($veggie)."\n"; echo "leafy: CLASS ".get_class($leafy); echo ", PARENT ".get_parent_class($leafy)."\n"; // show veggie properties echo "\nveggie: Properties\n"; print_vars($veggie); // and leafy methods echo "\nleafy: Methods\n"; print_methods($leafy); echo "\nParentage:\n"; class_parentage("leafy", "Spinach"); class_parentage("leafy", "Vegetable"); ?> </pre>

One important thing to note in the example above is that the object $leafy is an instance of the class Spinach which is a subclass of Vegetable, therefore the last part of the script above will output:

[...]
Parentage:
Object leafy does not belong to a subclass of Spinach
Object leafy belongs to class spinach a subclass of Vegetable

Table of Contents
call_user_method_array -- Call a user method given with an array of parameters [deprecated]
call_user_method -- Call a user method on an specific object [deprecated]
class_exists -- Checks if the class has been defined
get_class_methods -- Returns an array of class methods' names
get_class_vars -- Returns an array of default properties of the class
get_class -- Returns the name of the class of an object
get_declared_classes -- Returns an array with the name of the defined classes
get_object_vars -- Returns an associative array of object properties
get_parent_class -- Retrieves the parent class name for object or class
is_a -- Returns TRUE if the object is of this class or has this class as one of its parents
is_subclass_of -- Returns TRUE if the object has this class as one of its parents
method_exists -- Checks if the class method exists

call_user_method_array

(PHP 4 >= 4.0.5)

call_user_method_array -- Call a user method given with an array of parameters [deprecated]

Description

mixed call_user_method_array ( string method_name, object obj [, array paramarr])

Warning

The call_user_method_array() function is deprecated as of PHP 4.1.0, use the call_user_func_array() variety with the array(&$obj, "method_name") syntax instead.

Calls the method referred by method_name from the user defined obj object, using the parameters in paramarr.

Note: This function was added to the CVS code after release of PHP 4.0.4pl1

call_user_method

(PHP 3>= 3.0.3, PHP 4 )

call_user_method -- Call a user method on an specific object [deprecated]

Description

mixed call_user_method ( string method_name, object obj [, mixed parameter [, mixed ...]])

Warning

The call_user_method() function is deprecated as of PHP 4.1.0, use the call_user_func() variety with the array(&$obj, "method_name") syntax instead.

Calls the method referred by method_name from the user defined obj object. An example of usage is below, where we define a class, instantiate an object and use call_user_method() to call indirectly its print_info method.

<?php
class Country {
    var $NAME;
    var $TLD;
    
    function Country($name, $tld) {
        $this->NAME = $name;
        $this->TLD = $tld;
    }

    function print_info($prestr="") {
        echo $prestr."Country: ".$this->NAME."\n";
        echo $prestr."Top Level Domain: ".$this->TLD."\n";
    }
}

$cntry = new Country("Peru","pe");

echo "* Calling the object method directly\n";
$cntry->print_info();

echo "\n* Calling the same method indirectly\n";
call_user_method ("print_info", $cntry, "\t");
?>

class_exists

(PHP 4 )

class_exists -- Checks if the class has been defined

Description

bool class_exists ( string class_name)

This function returns TRUE if the class given by class_name has been defined, FALSE otherwise.

get_class_methods

(PHP 4 )

get_class_methods -- Returns an array of class methods' names

Description

array get_class_methods ( mixed class_name)

This function returns an array of method names defined for the class specified by class_name.

Note: As of PHP 4.0.6, you can specify the object itself instead of class_name. For example:
$class_methods = get_class_methods($my_class); // see below the full example

Example 1. get_class_methods() example
<?php class myclass { // constructor function myclass() { return(TRUE); } // method 1 function myfunc1() { return(TRUE); } // method 2 function myfunc2() { return(TRUE); } } $my_object = new myclass(); $class_methods = get_class_methods(get_class($my_object)); foreach ($class_methods as $method_name) { echo "$method_name\n"; } ?>

Will produce:

myclass
myfunc1
myfunc2

get_class_vars

(PHP 4 )

get_class_vars -- Returns an array of default properties of the class

Description

array get_class_vars ( string class_name)

This function will return an associative array of default properties of the class. The resulting array elements are in the form of varname => value.

Note: Uninitialized class variables will not be reported by get_class_vars().

Example 1. get_class_vars() example
<?php class myclass { var $var1; // this has no default value... var $var2 = "xyz"; var $var3 = 100; // constructor function myclass() { return(TRUE); } } $my_class = new myclass(); $class_vars = get_class_vars(get_class($my_class)); foreach ($class_vars as $name => $value) { echo "$name : $value\n"; } ?>

Will produce:

var2 : xyz
var3 : 100

get_class

(PHP 4 )

get_class -- Returns the name of the class of an object

Description

string get_class ( object obj)

This function returns the name of the class of which the object obj is an instance. Returns FALSE if obj is not an object.

Note: get_class() returns a user defined class name in lowercase. A class defined in a PHP extension is returned in its original notation.

get_declared_classes

(PHP 4 )

get_declared_classes -- Returns an array with the name of the defined classes

Description

array get_declared_classes ( void)

This function returns an array of the names of the declared classes in the current script.

Note: In PHP 4.0.1pl2, three extra classes are returned at the beginning of the array: stdClass (defined in Zend/zend.c), OverloadedTestClass (defined in ext/standard/basic_functions.c) and Directory (defined in ext/standard/dir.c).
Also note that depending on what libraries you have compiled into PHP, additional classes could be present. This means that you will not be able to define your own classes using these names. There is a list of predefined classes in the Predefined Classes section of the appendices.

get_object_vars

(PHP 4 )

get_object_vars -- Returns an associative array of object properties

Description

array get_object_vars ( object obj)

This function returns an associative array of defined object properties for the specified object obj. If variables declared in the class of which the obj is an instance, have not been assigned a value, those will not be returned in the array.
Example 1. Use of get_object_vars()
<?php class Point2D { var $x, $y; var $label; function Point2D($x, $y) { $this->x = $x; $this->y = $y; } function setLabel($label) { $this->label = $label; } function getPoint() { return array("x" => $this->x, "y" => $this->y, "label" => $this->label); } } // "$label" is declared but not defined $p1 = new Point2D(1.233, 3.445); print_r(get_object_vars($p1)); $p1->setLabel("point #1"); print_r(get_object_vars($p1)); ?>
The printout of the above program will be:
Array ( [x] => 1.233 [y] => 3.445 ) Array ( [x] => 1.233 [y] => 3.445 [label] => point #1 )

get_parent_class

(PHP 4 )

get_parent_class -- Retrieves the parent class name for object or class

Description

string get_parent_class ( mixed obj)

bool method_exists ( object object, string method_name)

This function returns TRUE if the method given by method_name has been defined for the given object, FALSE otherwise.

X. ClibPDF functions

Introduction

ClibPDF lets you create PDF documents with PHP. It is available for download from FastIO, but requires that you purchase a license for commercial use. ClibPDF functionality and API are similar to PDFlib.

This documentation should be read alongside the ClibPDF manual since it explains the library in much greater detail.

Many functions in the native ClibPDF and the PHP module, as well as in PDFlib, have the same name. All functions except for cpdf_open() take the handle for the document as their first parameter.

Currently this handle is not used internally since ClibPDF does not support the creation of several PDF documents at the same time. Actually, you should not even try it, the results are unpredictable. I can't oversee what the consequences in a multi threaded environment are. According to the author of ClibPDF this will change in one of the next releases (current version when this was written is 1.10). If you need this functionality use the pdflib module.

A nice feature of ClibPDF (and PDFlib) is the ability to create the pdf document completely in memory without using temporary files. It also provides the ability to pass coordinates in a predefined unit length. (This feature can also be simulated by pdf_translate() when using the PDFlib functions.)

Another nice feature of ClibPDF is the fact that any page can be modified at any time even if a new page has been already opened. The function cpdf_set_current_page() allows to leave the current page and presume modifying an other page.

Most of the functions are fairly easy to use. The most difficult part is probably creating a very simple PDF document at all. The following example should help you to get started. It creates a document with one page. The page contains the text "Times-Roman" in an outlined 30pt font. The text is underlined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

CPDF_PM_NONE (integer)
CPDF_PM_OUTLINES (integer)
CPDF_PM_THUMBS (integer)
CPDF_PM_FULLSCREEN (integer)
CPDF_PL_SINGLE (integer)
CPDF_PL_1COLUMN (integer)
CPDF_PL_2LCOLUMN (integer)
CPDF_PL_2RCOLUMN (integer)

Examples

Example 1. Simple ClibPDF Example

<?php
$cpdf = cpdf_open(0);
cpdf_page_init($cpdf, 1, 0, 595, 842, 1.0);
cpdf_add_outline($cpdf, 0, 0, 0, 1, "Page 1");
cpdf_begin_text($cpdf);
cpdf_set_font($cpdf, "Times-Roman", 30, "WinAnsiEncoding");
cpdf_set_text_rendering($cpdf, 1);
cpdf_text($cpdf, "Times Roman outlined", 50, 750);
cpdf_end_text($cpdf);
cpdf_moveto($cpdf, 50, 740);
cpdf_lineto($cpdf, 330, 740);
cpdf_stroke($cpdf);
cpdf_finalize($cpdf);
Header("Content-type: application/pdf");
cpdf_output_buffer($cpdf);
cpdf_close($cpdf);
?>

The pdflib distribution contains a more complex example which creates a series of pages with an analog clock. Here is that example converted into PHP using the ClibPDF extension:

Example 2. pdfclock example from pdflib 2.0 distribution

<?php
$radius = 200;
$margin = 20;
$pagecount = 40;

$pdf = cpdf_open(0);
cpdf_set_creator($pdf, "pdf_clock.php3");
cpdf_set_title($pdf, "Analog Clock");
  
while($pagecount-- > 0) {
  cpdf_page_init($pdf, $pagecount+1, 0, 2 * ($radius + $margin), 2 * ($radius + $margin), 1.0);
  
  cpdf_set_page_animation($pdf, 4, 0.5, 0, 0, 0);  /* wipe */
  
  cpdf_translate($pdf, $radius + $margin, $radius + $margin);
  cpdf_save($pdf);
  cpdf_setrgbcolor($pdf, 0.0, 0.0, 1.0);
  
  /* minute strokes */
  cpdf_setlinewidth($pdf, 2.0);
  for ($alpha = 0; $alpha < 360; $alpha += 6)
    {
    cpdf_rotate($pdf, 6.0);
    cpdf_moveto($pdf, $radius, 0.0);
    cpdf_lineto($pdf, $radius-$margin/3, 0.0);
    cpdf_stroke($pdf);
    }
  
  cpdf_restore($pdf);
  cpdf_save($pdf);
 
  /* 5 minute strokes */
  cpdf_setlinewidth($pdf, 3.0);
  for ($alpha = 0; $alpha < 360; $alpha += 30)
  {
    cpdf_rotate($pdf, 30.0);
    cpdf_moveto($pdf, $radius, 0.0);
    cpdf_lineto($pdf, $radius-$margin, 0.0);
    cpdf_stroke($pdf);
  }

  $ltime = getdate();

  /* draw hour hand */
  cpdf_save($pdf);
  cpdf_rotate($pdf, -(($ltime['minutes']/60.0) + $ltime['hours'] - 3.0) * 30.0);
  cpdf_moveto($pdf, -$radius/10, -$radius/20);
  cpdf_lineto($pdf, $radius/2, 0.0);
  cpdf_lineto($pdf, -$radius/10, $radius/20);
  cpdf_closepath($pdf);
  cpdf_fill($pdf);
  cpdf_restore($pdf);

  /* draw minute hand */
  cpdf_save($pdf);
  cpdf_rotate($pdf, -(($ltime['seconds']/60.0) + $ltime['minutes'] - 15.0) * 6.0);
  cpdf_moveto($pdf, -$radius/10, -$radius/20);
  cpdf_lineto($pdf, $radius * 0.8, 0.0);
  cpdf_lineto($pdf, -$radius/10, $radius/20);
  cpdf_closepath($pdf);
  cpdf_fill($pdf);
  cpdf_restore($pdf);

  /* draw second hand */
  cpdf_setrgbcolor($pdf, 1.0, 0.0, 0.0);
  cpdf_setlinewidth($pdf, 2);
  cpdf_save($pdf);
  cpdf_rotate($pdf, -(($ltime['seconds'] - 15.0) * 6.0));
  cpdf_moveto($pdf, -$radius/5, 0.0);
  cpdf_lineto($pdf, $radius, 0.0);
  cpdf_stroke($pdf);
  cpdf_restore($pdf);

  /* draw little circle at center */
  cpdf_circle($pdf, 0, 0, $radius/30);
  cpdf_fill($pdf);

  cpdf_restore($pdf);

  cpdf_finalize_page($pdf, $pagecount+1);
}

cpdf_finalize($pdf);
Header("Content-type: application/pdf");
cpdf_output_buffer($pdf);
cpdf_close($pdf);
?>

Note: The return value will be needed in further versions of ClibPDF as the first parameter in all other functions which are writing to the pdf document.
The ClibPDF library takes the filename "-" as a synonym for stdout. If PHP is compiled as an apache module this will not work because the way ClibPDF outputs to stdout does not work with apache. You can solve this problem by skipping the filename and using cpdf_output_buffer() to output the pdf document.

Description

void cpdf_rotate_text ( int pdfdoc, float angle)

Warning

This function is currently not documented; only the argument list is available.

cpdf_rotate

(PHP 3>= 3.0.8, PHP 4 )

cpdf_rotate -- Sets rotation

Description

void cpdf_rotate ( int pdf document, float angle)

The cpdf_rotate() function set the rotation in degrees to angle.

cpdf_save_to_file

(PHP 3>= 3.0.8, PHP 4 )

cpdf_save_to_file -- Writes the pdf document into a file

Description

void cpdf_save_to_file ( int pdf document, string filename)

void cpdf_set_action_url ( int pdfdoc, float xll, float yll, float xur, float xur, string url [, int mode])

void cpdf_set_font_directories ( int pdfdoc, string pfmdir, string pfbdir)

Warning

This function is currently not documented; only the argument list is available.

cpdf_set_font_map_file

(PHP 4 >= 4.0.6)

cpdf_set_font_map_file -- Sets fontname to filename translation map when using external fonts

Description

void cpdf_set_font_map_file ( int pdfdoc, string filename)

Warning

This function is currently not documented; only the argument list is available.

cpdf_set_font

(PHP 3>= 3.0.8, PHP 4 )

cpdf_set_font -- Select the current font face and size

Description

void cpdf_set_font ( int pdf document, string font name, float size, string encoding)

The cpdf_set_font() function sets the current font face, font size and encoding. Currently only the standard postscript fonts are supported.

void cpdf_set_page_animation ( int pdf document, int transition, float duration)

The cpdf_set_page_animation() function set the transition between following pages.

The value of transition can be

0 for none,

1 for two lines sweeping across the screen reveal the page,

2 for multiple lines sweeping across the screen reveal the page,

3 for a box reveals the page,

4 for a single line sweeping across the screen reveals the page,

5 for the old page dissolves to reveal the page,

6 for the dissolve effect moves from one screen edge to another,

void cpdf_set_text_rendering ( int pdf document, int mode)

void cpdf_show_xy ( int pdf document, string text, float x-coor, float y-coor [, int mode])

The cpdf_show_xy() function outputs the string text at position with coordinates (x-coor, y-coor).

Note: The function cpdf_show_xy() is identical to cpdf_text() without the optional parameters.

The optional parameter mode determines the unit length. If it's 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit. The optional parameter orientation is the rotation of the text in degree. The optional parameter alignmode determines how the text is aligned.

See the ClibPDF documentation for possible values.

cpdf_translate

(PHP 3>= 3.0.8, PHP 4 )

cpdf_translate -- Sets origin of coordinate system

Description

void cpdf_translate ( int pdf document, float x-coor, float y-coor [, int mode])

The cpdf_translate() function set the origin of coordinate system to the point (x-coor, y-coor).

XI. Crack functions

Introduction

These functions allow you to use the CrackLib library to test the 'strength' of a password. The 'strength' of a password is tested by that checks length, use of upper and lower case and checked against the specified CrackLib dictionary. CrackLib will also give helpful diagnostic messages that will help 'strengthen' the password.

Requirements

More information regarding CrackLib along with the library can be found at http://www.users.dircon.co.uk/~crypto/.

Installation

In order to use these functions, you must compile PHP with Crack support by using the --with-crack[=DIR] option.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Crack configuration options

Name	Default	Changeable
crack.default_dictionary	NULL	PHP_INI_SYSTEM

For further details and definition of the PHP_INI_* constants see ini_set().

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Examples

This example shows how to open a CrackLib dictionary, test a given password, retrieve any diagnostic messages, and close the dictionary.
Example 1. CrackLib example
<?php // Open CrackLib Dictionary $dictionary = crack_opendict('/usr/local/lib/pw_dict') or die('Unable to open CrackLib dictionary'); // Perform password check $check = crack_check($dictionary, 'gx9A2s0x'); // Retrieve messages $diag = crack_getlastmessage(); echo $diag; // 'strong password' // Close dictionary crack_closedict($dictionary); ?>

Note: If crack_check() returns TRUE, crack_getlastmessage() will return 'strong password'.

Table of Contents
crack_check -- Performs an obscure check with the given password
crack_closedict -- Closes an open CrackLib dictionary
crack_getlastmessage -- Returns the message from the last obscure check
crack_opendict -- Opens a new CrackLib dictionary

crack_check

(PHP 4 >= 4.0.5)

crack_check -- Performs an obscure check with the given password

Description

bool crack_check ( [resource dictionary, string password])

Returns TRUE if password is strong, or FALSE otherwise.

Warning

This function is EXPERIMENTAL. The behaviour of this function, the name of this function, and anything else documented about this function may change without notice in a future release of PHP. Use this function at your own risk.

crack_check() performs an obscure check with the given password on the specified dictionary. If dictionary is not specified, the last opened dictionary is used.

crack_closedict

(PHP 4 >= 4.0.5)

crack_closedict -- Closes an open CrackLib dictionary

Description

bool crack_closedict ( [resource dictionary])

Returns TRUE on success or FALSE on failure.

Warning

crack_closedict() closes the specified dictionary identifier. If dictionary is not specified, the current dictionary is closed.

crack_getlastmessage

(PHP 4 >= 4.0.5)

crack_getlastmessage -- Returns the message from the last obscure check

Description

string crack_getlastmessage ( void)

Warning

crack_getlastmessage() returns the message from the last obscure check.

crack_opendict

(PHP 4 >= 4.0.5)

crack_opendict -- Opens a new CrackLib dictionary

Description

resource crack_opendict ( string dictionary)

Returns a dictionary resource identifier on success, or FALSE on failure.

Warning

crack_opendict() opens the specified CrackLib dictionary for use with crack_check().

Note: Only one dictionary may be open at a time.

See also: crack_check(), and crack_closedict().

XII. CURL, Client URL Library Functions

Introduction

PHP supports libcurl, a library created by Daniel Stenberg, that allows you to connect and communicate to many different types of servers with many different types of protocols. libcurl currently supports the http, https, ftp, gopher, telnet, dict, file, and ldap protocols. libcurl also supports HTTPS certificates, HTTP POST, HTTP PUT, FTP uploading (this can also be done with PHP's ftp extension), HTTP form based upload, proxies, cookies, and user+password authentication.

These functions have been added in PHP 4.0.2.

Requirements

In order to use the CURL functions you need to install the CURL package. PHP requires that you use CURL 7.0.2-beta or higher. PHP will not work with any version of CURL below version 7.0.2-beta. From PHP version 4.2.3 you will atleast need CURL version 7.9.0 or higher.

Installation

To use PHP's CURL support you must also compile PHP --with-curl[=DIR] where DIR is the location of the directory containing the lib and include directories. In the "include" directory there should be a folder named "curl" which should contain the easy.h and curl.h files. There should be a file named "libcurl.a" located in the "lib" directory.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

CURLOPT_PORT (integer)
CURLOPT_FILE (integer)
CURLOPT_INFILE (integer)
CURLOPT_INFILESIZE (integer)
CURLOPT_URL (integer)
CURLOPT_PROXY (integer)
CURLOPT_VERBOSE (integer)
CURLOPT_HEADER (integer)
CURLOPT_HTTPHEADER (integer)
CURLOPT_NOPROGRESS (integer)
CURLOPT_NOBODY (integer)
CURLOPT_FAILONERROR (integer)
CURLOPT_UPLOAD (integer)
CURLOPT_POST (integer)
CURLOPT_FTPLISTONLY (integer)
CURLOPT_FTPAPPEND (integer)
CURLOPT_NETRC (integer)
CURLOPT_FOLLOWLOCATION (integer)
CURLOPT_FTPASCII (integer)
CURLOPT_PUT (integer)
CURLOPT_MUTE (integer)
CURLOPT_USERPWD (integer)
CURLOPT_PROXYUSERPWD (integer)
CURLOPT_RANGE (integer)
CURLOPT_TIMEOUT (integer)
CURLOPT_POSTFIELDS (integer)
CURLOPT_REFERER (integer)
CURLOPT_USERAGENT (integer)
CURLOPT_FTPPORT (integer)
CURLOPT_LOW_SPEED_LIMIT (integer)
CURLOPT_LOW_SPEED_TIME (integer)
CURLOPT_RESUME_FROM (integer)
CURLOPT_COOKIE (integer)
CURLOPT_SSLCERT (integer)
CURLOPT_SSLCERTPASSWD (integer)
CURLOPT_WRITEHEADER (integer)
CURLOPT_SSL_VERIFYHOST (integer)
CURLOPT_COOKIEFILE (integer)
CURLOPT_SSLVERSION (integer)
CURLOPT_TIMECONDITION (integer)
CURLOPT_TIMEVALUE (integer)
CURLOPT_CUSTOMREQUEST (integer)
CURLOPT_STDERR (integer)
CURLOPT_TRANSFERTEXT (integer)
CURLOPT_RETURNTRANSFER (integer)
CURLOPT_QUOTE (integer)
CURLOPT_POSTQUOTE (integer)
CURLOPT_INTERFACE (integer)
CURLOPT_KRB4LEVEL (integer)
CURLOPT_HTTPPROXYTUNNEL (integer)
CURLOPT_FILETIME (integer)
CURLOPT_WRITEFUNCTION (integer)
CURLOPT_READFUNCTION (integer)
CURLOPT_PASSWDFUNCTION (integer)
CURLOPT_HEADERFUNCTION (integer)
CURLOPT_MAXREDIRS (integer)
CURLOPT_MAXCONNECTS (integer)
CURLOPT_CLOSEPOLICY (integer)
CURLOPT_FRESH_CONNECT (integer)
CURLOPT_FORBID_REUSE (integer)
CURLOPT_RANDOM_FILE (integer)
CURLOPT_EGDSOCKET (integer)
CURLOPT_CONNECTTIMEOUT (integer)
CURLOPT_SSL_VERIFYPEER (integer)
CURLOPT_CAINFO (integer)
CURLOPT_COOKIEJAR (integer)
CURLOPT_SSL_CIPHER_LIST (integer)
CURLOPT_BINARYTRANSFER (integer)
CURLCLOSEPOLICY_LEAST_RECENTLY_USED (integer)
CURLCLOSEPOLICY_LEAST_TRAFFIC (integer)
CURLCLOSEPOLICY_SLOWEST (integer)
CURLCLOSEPOLICY_CALLBACK (integer)
CURLCLOSEPOLICY_OLDEST (integer)
CURLINFO_EFFECTIVE_URL (integer)
CURLINFO_HTTP_CODE (integer)
CURLINFO_HEADER_SIZE (integer)
CURLINFO_REQUEST_SIZE (integer)
CURLINFO_TOTAL_TIME (integer)
CURLINFO_NAMELOOKUP_TIME (integer)
CURLINFO_CONNECT_TIME (integer)
CURLINFO_PRETRANSFER_TIME (integer)
CURLINFO_SIZE_UPLOAD (integer)
CURLINFO_SIZE_DOWNLOAD (integer)
CURLINFO_SPEED_DOWNLOAD (integer)
CURLINFO_SPEED_UPLOAD (integer)
CURLINFO_FILETIME (integer)
CURLINFO_SSL_VERIFYRESULT (integer)
CURLINFO_CONTENT_LENGTH_DOWNLOAD (integer)
CURLINFO_CONTENT_LENGTH_UPLOAD (integer)
CURLE_OK (integer)
CURLE_UNSUPPORTED_PROTOCOL (integer)
CURLE_FAILED_INIT (integer)
CURLE_URL_MALFORMAT (integer)
CURLE_URL_MALFORMAT_USER (integer)
CURLE_COULDNT_RESOLVE_PROXY (integer)
CURLE_COULDNT_RESOLVE_HOST (integer)
CURLE_COULDNT_CONNECT (integer)
CURLE_FTP_WEIRD_SERVER_REPLY (integer)
CURLE_FTP_ACCESS_DENIED (integer)
CURLE_FTP_USER_PASSWORD_INCORRECT (integer)
CURLE_FTP_WEIRD_PASS_REPLY (integer)
CURLE_FTP_WEIRD_USER_REPLY (integer)
CURLE_FTP_WEIRD_PASV_REPLY (integer)
CURLE_FTP_WEIRD_227_FORMAT (integer)
CURLE_FTP_CANT_GET_HOST (integer)
CURLE_FTP_CANT_RECONNECT (integer)
CURLE_FTP_COULDNT_SET_BINARY (integer)
CURLE_PARTIAL_FILE (integer)
CURLE_FTP_COULDNT_RETR_FILE (integer)
CURLE_FTP_WRITE_ERROR (integer)
CURLE_FTP_QUOTE_ERROR (integer)
CURLE_HTTP_NOT_FOUND (integer)
CURLE_WRITE_ERROR (integer)
CURLE_MALFORMAT_USER (integer)
CURLE_FTP_COULDNT_STOR_FILE (integer)
CURLE_READ_ERROR (integer)
CURLE_OUT_OF_MEMORY (integer)
CURLE_OPERATION_TIMEOUTED (integer)
CURLE_FTP_COULDNT_SET_ASCII (integer)
CURLE_FTP_PORT_FAILED (integer)
CURLE_FTP_COULDNT_USE_REST (integer)
CURLE_FTP_COULDNT_GET_SIZE (integer)
CURLE_HTTP_RANGE_ERROR (integer)
CURLE_HTTP_POST_ERROR (integer)
CURLE_SSL_CONNECT_ERROR (integer)
CURLE_FTP_BAD_DOWNLOAD_RESUME (integer)
CURLE_FILE_COULDNT_READ_FILE (integer)
CURLE_LDAP_CANNOT_BIND (integer)
CURLE_LDAP_SEARCH_FAILED (integer)
CURLE_LIBRARY_NOT_FOUND (integer)
CURLE_FUNCTION_NOT_FOUND (integer)
CURLE_ABORTED_BY_CALLBACK (integer)
CURLE_BAD_FUNCTION_ARGUMENT (integer)
CURLE_BAD_CALLING_ORDER (integer)
CURLE_HTTP_PORT_FAILED (integer)
CURLE_BAD_PASSWORD_ENTERED (integer)
CURLE_TOO_MANY_REDIRECTS (integer)
CURLE_UNKNOWN_TELNET_OPTION (integer)
CURLE_TELNET_OPTION_SYNTAX (integer)
CURLE_OBSOLETE (integer)
CURLE_SSL_PEER_CERTIFICATE (integer)

Examples

Once you've compiled PHP with CURL support, you can begin using the curl functions. The basic idea behind the CURL functions is that you initialize a CURL session using the curl_init(), then you can set all your options for the transfer via the curl_exec() and then you finish off your session using the curl_close(). Here is an example that uses the CURL functions to fetch the example.com homepage into a file:
Example 1. Using PHP's CURL module to fetch the example.com homepage
<?php $ch = curl_init ("http://www.example.com/"); $fp = fopen ("example_homepage.txt", "w"); curl_setopt ($ch, CURLOPT_FILE, $fp); curl_setopt ($ch, CURLOPT_HEADER, 0); curl_exec ($ch); curl_close ($ch); fclose ($fp); ?>

Table of Contents
curl_close -- Close a CURL session
curl_errno -- Return an integer containing the last error number
curl_error -- Return a string containing the last error for the current session
curl_exec -- Perform a CURL session
curl_getinfo -- Get information regarding a specific transfer
curl_init -- Initialize a CURL session
curl_setopt -- Set an option for a CURL transfer
curl_version -- Return the current CURL version

curl_close

(PHP 4 >= 4.0.2)

curl_close -- Close a CURL session

bool curl_exec ( resource ch)

This function should be called after you initialize a CURL session and all the options for the session are set. Its purpose is simply to execute the predefined CURL session (given by the ch).

Tip: As with anything that outputs its result directly to the browser, you can use the output-control functions to capture the output of this function, and save it in a string (for example).

curl_getinfo

(PHP 4 >= 4.0.4)

curl_getinfo -- Get information regarding a specific transfer

Description

string curl_getinfo ( resource ch, int opt)

Warning

This function is currently not documented; only the argument list is available.

curl_init

(PHP 4 >= 4.0.2)

curl_init -- Initialize a CURL session

Description

resource curl_init ( [string url])

The curl_init() will initialize a new session and return a CURL handle for use with the curl_setopt(), curl_exec(), and curl_close() functions. If the optional url parameter is supplied then the CURLOPT_URL option will be set to the value of the parameter. You can manually set this using the curl_setopt() function.
Example 1. Initializing a new CURL session and fetching a webpage
<?php $ch = curl_init(); curl_setopt ($ch, CURLOPT_URL, "http://www.example.com/"); curl_setopt ($ch, CURLOPT_HEADER, 0); curl_exec ($ch); curl_close ($ch); ?>

curl_setopt

(PHP 4 >= 4.0.2)

curl_setopt -- Set an option for a CURL transfer

Description

bool curl_setopt ( resource ch, string option, mixed value)

The curl_setopt() function will set options for a CURL session identified by the ch parameter. The option parameter is the option you want to set, and the value is the value of the option given by the option.

The value should be a long for the following options (specified in the option parameter):

CURLOPT_INFILESIZE: When you are uploading a file to a remote site, this option should be used to tell PHP what the expected size of the infile will be.
CURLOPT_VERBOSE: Set this option to a non-zero value if you want CURL to report everything that is happening.
CURLOPT_HEADER: Set this option to a non-zero value if you want the header to be included in the output.
CURLOPT_NOPROGRESS: Set this option to a non-zero value if you don't want PHP to display a progress meter for CURL transfers.
Note: PHP automatically sets this option to a non-zero parameter, this should only be changed for debugging purposes.
CURLOPT_NOBODY: Set this option to a non-zero value if you don't want the body included with the output.
CURLOPT_FAILONERROR: Set this option to a non-zero value if you want PHP to fail silently if the HTTP code returned is greater than 300. The default behavior is to return the page normally, ignoring the code.
CURLOPT_UPLOAD: Set this option to a non-zero value if you want PHP to prepare for an upload.
CURLOPT_POST: Set this option to a non-zero value if you want PHP to do a regular HTTP POST. This POST is a normal application/x-www-form-urlencoded kind, most commonly used by HTML forms.
CURLOPT_FTPLISTONLY: Set this option to a non-zero value and PHP will just list the names of an FTP directory.
CURLOPT_FTPAPPEND: Set this option to a non-zero value and PHP will append to the remote file instead of overwriting it.
CURLOPT_NETRC: Set this option to a non-zero value and PHP will scan your ~./netrc file to find your username and password for the remote site that you're establishing a connection with.
CURLOPT_FOLLOWLOCATION: Set this option to a non-zero value to follow any "Location: " header that the server sends as a part of the HTTP header (note this is recursive, PHP will follow as many "Location: " headers that it is sent.)
CURLOPT_PUT: Set this option to a non-zero value to HTTP PUT a file. The file to PUT must be set with the CURLOPT_INFILE and CURLOPT_INFILESIZE.
CURLOPT_MUTE: Set this option to a non-zero value and PHP will be completely silent with regards to the CURL functions.
CURLOPT_TIMEOUT: Pass a long as a parameter that contains the maximum time, in seconds, that you'll allow the CURL functions to take.
CURLOPT_LOW_SPEED_LIMIT: Pass a long as a parameter that contains the transfer speed in bytes per second that the transfer should be below during CURLOPT_LOW_SPEED_TIME seconds for PHP to consider it too slow and abort.
CURLOPT_LOW_SPEED_TIME: Pass a long as a parameter that contains the time in seconds that the transfer should be below the CURLOPT_LOW_SPEED_LIMIT for PHP to consider it too slow and abort.
CURLOPT_RESUME_FROM: Pass a long as a parameter that contains the offset, in bytes, that you want the transfer to start from.
CURLOPT_SSLVERSION: Pass a long as a parameter that contains the SSL version (2 or 3) to use. By default PHP will try and determine this by itself, although, in some cases you must set this manually.
CURLOPT_SSL_VERIFYHOST: Pass a long if CURL should verify the Common name of the peer certificate in the SSL handshake. A value of 1 denotes that we should check for the existence of the common name, a value of 2 denotes that we should make sure it matches the provided hostname.
CURLOPT_TIMECONDITION: Pass a long as a parameter that defines how the CURLOPT_TIMEVALUE is treated. You can set this parameter to TIMECOND_IFMODSINCE or TIMECOND_ISUNMODSINCE. This is a HTTP-only feature.
CURLOPT_TIMEVALUE: Pass a long as a parameter that is the time in seconds since January 1st, 1970. The time will be used as specified by the CURLOPT_TIMEVALUE option, or by default the TIMECOND_IFMODSINCE will be used.
CURLOPT_RETURNTRANSFER: Pass a non-zero value if you want CURL to directly return the transfer instead of printing it out directly.

The value parameter should be a string for the following values of the option parameter:

CURLOPT_URL: This is the URL that you want PHP to fetch. You can also set this option when initializing a session with the curl_init() function.
CURLOPT_USERPWD: Pass a string formatted in the [username]:[password] manner, for PHP to use for the connection.
CURLOPT_PROXYUSERPWD: Pass a string formatted in the [username]:[password] format for connection to the HTTP proxy.
CURLOPT_RANGE: Pass the specified range you want. It should be in the "X-Y" format, where X or Y may be left out. The HTTP transfers also support several intervals, separated with commas as in X-Y,N-M.
CURLOPT_POSTFIELDS: Pass a string containing the full data to post in an HTTP "POST" operation.
CURLOPT_REFERER: Pass a string containing the "referer" header to be used in an HTTP request.
CURLOPT_USERAGENT: Pass a string containing the "user-agent" header to be used in an HTTP request.
CURLOPT_FTPPORT: Pass a string containing the value which will be used to get the IP address to use for the ftp "POST" instruction. The POST instruction tells the remote server to connect to our specified IP address. The string may be a plain IP address, a hostname, a network interface name (under UNIX), or just a plain '-' to use the systems default IP address.
CURLOPT_COOKIE: Pass a string containing the content of the cookie to be set in the HTTP header.
CURLOPT_SSLCERT: Pass a string containing the filename of PEM formatted certificate.
CURLOPT_SSLCERTPASSWD: Pass a string containing the password required to use the CURLOPT_SSLCERT certificate.
CURLOPT_COOKIEFILE: Pass a string containing the name of the file containing the cookie data. The cookie file can be in Netscape format, or just plain HTTP-style headers dumped into a file.
CURLOPT_CUSTOMREQUEST: Pass a string to be used instead of GET or HEAD when doing an HTTP request. This is useful for doing DELETE or other, more obscure, HTTP requests. Valid values are things like GET, POST, and so on; i.e. do not enter a whole HTTP request line here. For instance, entering 'GET /index.html HTTP/1.0\r\n\r\n' would be incorrect.
Note: Don't do this without making sure your server supports the command first.
CURLOPT_PROXY: Give the name of the HTTP proxy to tunnel requests through.
CURLOPT_INTERFACE: Pass the name of the outgoing network interface to use. This can be an interface name, an IP address or a host name.
CURLOPT_KRB4LEVEL: Pass the KRB4 (Kerberos 4) security level. Anyone of the following strings (in order from least powerful, to most powerful): 'clear', 'safe', 'confidential', 'private'. If the string does not match one of these, then 'private' is used. If you set this to NULL, this disables KRB4 security. KRB4 security only works with FTP transactions currently.
CURLOPT_HTTPHEADER: Pass an array of HTTP header fields to set.
CURLOPT_QUOTE: Pass an array of FTP commands to perform on the server prior to the FTP request.
CURLOPT_POSTQUOTE: Pass an array of FTP commands to execute on the server, after the FTP request has been performed.

The following options expect a file descriptor that is obtained by using the fopen() function:

CURLOPT_FILE: The file where the output of your transfer should be placed, the default is STDOUT.
CURLOPT_INFILE: The file where the input of your transfer comes from.
CURLOPT_WRITEHEADER: The file to write the header part of the output into.
CURLOPT_STDERR: The file to write errors to instead of stderr.

curl_version

(PHP 4 >= 4.0.2)

curl_version -- Return the current CURL version

Description

string curl_version ( void)

The curl_version() function returns a string containing the current CURL version.

XIII. Cybercash payment functions

Installation

These functions are only available if the interpreter has been compiled with the --with-cybercash=[DIR].

Table of Contents
cybercash_base64_decode -- base64 decode data for Cybercash
cybercash_base64_encode -- base64 encode data for Cybercash
cybercash_decr -- Cybercash decrypt
cybercash_encr -- Cybercash encrypt

The function returns an associative array with the elements "errcode" and, if "errcode" is FALSE, "outbuff" (string), "outLth" (long) and "macbuff" (string).

cybercash_encr

(PHP 4 )

cybercash_encr -- Cybercash encrypt

Description

array cybercash_encr ( string wmk, string sk, string inbuff)

The function returns an associative array with the elements "errcode" and, if "errcode" is FALSE, "outbuff" (string), "outLth" (long) and "macbuff" (string).

XIV. Crédit Mutuel CyberMUT functions

Introduction

This extension allows you to process credit cards transactions using Crédit Mutuel CyberMUT system (http://www.creditmutuel.fr/centre_commercial/vendez_sur_internet.html).

CyberMUT is a popular Web Payment Service in France, provided by the Crédit Mutuel bank. If you are foreign in France, these functions will not be useful for you.

The use of these functions is almost identical to the original SDK functions, except for the parameters of return for cybermut_creerformulairecm() and cybermut_creerreponsecm(), which are returned directly by functions PHP, whereas they had passed in reference in the original functions.

These functions have been added in PHP 4.0.6.

Note: These functions only provide a link to CyberMUT SDK. Be sure to read the CyberMUT Developers Guide for full details of the required parameters.

Installation

These functions are only available if PHP has been compiled with the --with-cybermut[=DIR] option, where DIR is the location of libcm-mac.a and cm-mac.h. You will require the appropriate SDK for your platform, which may be sent to you after your CyberMUT's subscription (contact them via Web, or go to the nearest Crédit Mutuel).

Table of Contents
cybermut_creerformulairecm -- Generate HTML form of request for payment
cybermut_creerreponsecm -- Generate the acknowledgement of delivery of the confirmation of payment
cybermut_testmac -- Make sure that there no was data diddling contained in the received message of confirmation

cybermut_creerformulairecm

(PHP 4 >= 4.0.5)

cybermut_creerformulairecm -- Generate HTML form of request for payment

Description

string cybermut_creerformulairecm ( string url_CM, string version, string TPE, string montant, string ref_commande, string texte_libre, string url_retour, string url_retour_ok, string url_retour_err, string langue, string code_societe, string texte_bouton)

cybermut_creerformulairecm() is used to generate the HTML form of request for payment.

Example 1. First step of payment (equiv cgi1.c)

<?php
// Directory where the keys are located
putenv("CMKEYDIR=/var/creditmut/cles");
 
// Version number
$VERSION="1.2";

  $retour =  cybermut_creerformulairecm(
  "https://www.creditmutuel.fr/test/telepaiement/paiement.cgi",
  $VERSION,
  "1234567890",
  "300FRF",
  $REFERENCE,
  $TEXTE_LIBRE,
  $URL_RETOUR,
  $URL_RETOUR_OK,
  $URL_RETOUR_ERR,
  "francais",
  "company",
  "Paiement par carte bancaire");
 
  echo $retour;                                                               
?>

cybermut_creerreponsecm

(PHP 4 >= 4.0.5)

cybermut_creerreponsecm -- Generate the acknowledgement of delivery of the confirmation of payment

Description

string cybermut_creerreponsecm ( string phrase)

cybermut_creerreponsecm() returns a string containing delivery acknowledgement message.

The parameter is "OK" if the message of confirmation of the payment was correctly identified by cybermut_testmac(). Any other chain is regarded as an error message.

cybermut_testmac

(PHP 4 >= 4.0.5)

cybermut_testmac -- Make sure that there no was data diddling contained in the received message of confirmation

Description

bool cybermut_testmac ( string code_MAC, string version, string TPE, string cdate, string montant, string ref_commande, string texte_libre, string code-retour)

cybermut_testmac() is used to make sure that there was not data diddling contained in the received message of confirmation. Pay attention to parameters code-retour and texte-libre, which cannot be evaluated as is, because of the dash. You must retrieve them by using:
<?php $code_retour = $_GET["code-retour"]; $texte_libre = $_GET["texte-libre"]; ?>

Example 1. Last step of payment (equiv cgi2.c)

<?php
// Make sure that Enable Track Vars is ON.
// Directory where are located the keys
putenv("CMKEYDIR=/var/creditmut/cles");
 
// Version number
$VERSION="1.2";

$texte_libre = $_GET["texte-libre"];
$code_retour = $_GET["code-retour"];                                     

$mac_ok = cybermut_testmac($MAC,$VERSION,$TPE,$date,$montant,$reference,$texte_libre,$code_retour);

if ($mac_ok) {

  //
  // insert data processing here
  //
  //

  $result=cybermut_creerreponsecm("OK");
} else {
  $result=cybermut_creerreponsecm("Document Falsifie");
}
 
?>

XV. Cyrus IMAP administration functions

Introduction

Warning

This function is currently not documented; only the argument list is available.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

CYRUS_CONN_NONSYNCLITERAL (integer)
CYRUS_CONN_INITIALRESPONSE (integer)
CYRUS_CALLBACK_NUMBERED (integer)
CYRUS_CALLBACK_NOLITERAL (integer)

Table of Contents
cyrus_authenticate -- Authenticate against a Cyrus IMAP server
cyrus_bind -- Bind callbacks to a Cyrus IMAP connection
cyrus_close -- Close connection to a Cyrus IMAP server
cyrus_connect -- Connect to a Cyrus IMAP server
cyrus_query -- Send a query to a Cyrus IMAP server
cyrus_unbind -- Unbind ...

XVI. Character type functions

Introduction

The functions provided by this extension check whether a character or string falls into a certain character class according to the current locale (see also setlocale()).

When called with an integer argument these functions behave exactly like their C counterparts from "ctype.h".

When called with a string argument they will check every character in the string and will only return TRUE if every character in the string matches the requested criteria. When called with an empty string the result will always be TRUE.

Passing anything else but a string or integer will return FALSE immediately.

Requirements

None besides functions from the standard C library which are always available.

Installation

Beginning with PHP 4.2.0 these functions are enabled by default. For older versions you have to configure and compile PHP with --enable-ctype.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Table of Contents
ctype_alnum -- Check for alphanumeric character(s)
ctype_alpha -- Check for alphabetic character(s)
ctype_cntrl -- Check for control character(s)
ctype_digit -- Check for numeric character(s)
ctype_graph -- Check for any printable character(s) except space
ctype_lower -- Check for lowercase character(s)
ctype_print -- Check for printable character(s)
ctype_punct -- Check for any printable character which is not whitespace or an alphanumeric character
ctype_space -- Check for whitespace character(s)
ctype_upper -- Check for uppercase character(s)
ctype_xdigit -- Check for character(s) representing a hexadecimal digit

See also ctype_alpha() and ctype_upper().

ctype_print

(PHP 4 >= 4.0.4)

ctype_print -- Check for printable character(s)

Description

bool ctype_print ( string text)

Returns TRUE if every character in text will actually create output (including blanks). Returns FALSE if text contains control characters or characters that do not have any output or control function at all.

ctype_punct

(PHP 4 >= 4.0.4)

ctype_punct -- Check for any printable character which is not whitespace or an alphanumeric character

Description

bool ctype_punct ( string text)

Returns TRUE if every character in text is printable, but neither letter, digit or blank, FALSE otherwise.

See also ctype_cntrl(), ctype_graph(), and ctype_punct().

ctype_space

(PHP 4 >= 4.0.4)

ctype_space -- Check for whitespace character(s)

Description

bool ctype_space ( string text)

Returns TRUE if every character in text creates some sort of white space, FALSE otherwise. Besides the blank character this also includes tab, vertical tab, line feed, carriage return and form feed characters.

ctype_upper

(PHP 4 >= 4.0.4)

ctype_upper -- Check for uppercase character(s)

Description

bool ctype_upper ( string text)

Returns TRUE if every character in text is a uppercase letter in the current locale.

See also ctype_alpha() and ctype_lower().

ctype_xdigit

(PHP 4 >= 4.0.4)

ctype_xdigit -- Check for character(s) representing a hexadecimal digit

Description

bool ctype_xdigit ( string text)

Returns TRUE if every character in text is a hexadecimal 'digit', that is a decimal digit or a character from [A-Fa-f] , FALSE otherwise.

XVII. Database (dbm-style) abstraction layer functions

Introduction

These functions build the foundation for accessing Berkeley DB style databases.

This is a general abstraction layer for several file-based databases. As such, functionality is limited to a common subset of features supported by modern databases such as Sleepycat Software's DB2. (This is not to be confused with IBM's DB2 software, which is supported through the ODBC functions.)

Requirements

The behaviour of various aspects depends on the implementation of the underlying database. Functions such as dba_optimize() and dba_sync() will do what they promise for one database and will do nothing for others. You have to download and install supported dba-Handlers.

Table 1. List of DBA handlers

Handler	Notes
`dbm`	Dbm is the oldest (original) type of Berkeley DB style databases. You should avoid it, if possible. We do not support the compatibility functions built into DB2 and gdbm, because they are only compatible on the source code level, but cannot handle the original dbm format.
`ndbm`	Ndbm is a newer type and more flexible than dbm. It still has most of the arbitrary limits of dbm (therefore it is deprecated).
`gdbm`	Gdbm is the GNU database manager.
`db2`	DB2 is Sleepycat Software's DB2. It is described as "a programmatic toolkit that provides high-performance built-in database support for both standalone and client/server applications.
`db3`	DB3 is Sleepycat Software's DB3.
`cdb`	Cdb is "a fast, reliable, lightweight package for creating and reading constant databases." It is from the author of qmail and can be found here. Since it is constant, we support only reading operations.

When invoking the dba_open() or dba_popen() functions, one of the handler names must be supplied as an argument. The actually available list of handlers is displayed by invoking phpinfo().

Installation

By using the --enable-dba=shared configuration option you can build a dynamic loadable modul to enable PHP for basic support of dbm-style databases. You also have to add support for at least one of the following handlers by specifying the --with-XXXX configure switch to your PHP configure line.

Table 2. Supported DBA handlers

Handler	Configure Switch
`dbm`	To enable support for dbm add `--with-dbm[=DIR]`.
`ndbm`	To enable support for ndbm add `--with-ndbm[=DIR]`.
`gdbm`	To enable support for gdbm add `--with-gdbm[=DIR]`.
`db2`	To enable support for db2 add `--with-db2[=DIR]`.
`db3`	To enable support for db3 add `--with-db3[=DIR]`.
`cdb`	To enable support for cdb add `--with-cdb[=DIR]`.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

The functions dba_open() and dba_popen() return a handle to the specified database file to access which is used by all other dba-function calls.

Predefined Constants

This extension has no constants defined.

Examples

Example 1. DBA example
<?php $id = dba_open ("/tmp/test.db", "n", "db2"); if (!$id) { echo "dba_open failed\n"; exit; } dba_replace ("key", "This is an example!", $id); if (dba_exists ("key", $id)) { echo dba_fetch ("key", $id); dba_delete ("key", $id); } dba_close ($id); ?>

DBA is binary safe and does not have any arbitrary limits. However, it inherits all limits set by the underlying database implementation.

All file-based databases must provide a way of setting the file mode of a new created database, if that is possible at all. The file mode is commonly passed as the fourth argument to dba_open() or dba_popen().

You can access all entries of a database in a linear way by using the dba_firstkey() and dba_nextkey() functions. You may not change the database while traversing it.

Example 2. Traversing a database
<?php // ...open database... $key = dba_firstkey ($id); while ($key != false) { if (...) { // remember the key to perform some action later $handle_later[] = $key; } $key = dba_nextkey ($id); } for ($i = 0; $i < count($handle_later); $i++) dba_delete ($handle_later[$i], $id); ?>

Table of Contents
dba_close -- Close database
dba_delete -- Delete entry specified by key
dba_exists -- Check whether key exists
dba_fetch -- Fetch data specified by key
dba_firstkey -- Fetch first key
dba_insert -- Insert entry
dba_nextkey -- Fetch next key
dba_open -- Open database
dba_optimize -- Optimize database
dba_popen -- Open database persistently
dba_replace -- Replace or insert entry
dba_sync -- Synchronize database

dba_insert() returns TRUE or FALSE, depending on whether it succeeds of fails, respectively.

dba_nextkey

(PHP 3>= 3.0.8, PHP 4 )

dba_nextkey -- Fetch next key

Description

string dba_nextkey ( resource handle)

dba_nextkey() returns the next key of the database specified by handle and advances the internal key pointer.

handle is a database handle returned by dba_open().

dba_nextkey() returns the key or FALSE depending on whether it succeeds or fails, respectively.

See also: dba_firstkey() and example 2 in the DBA examples

dba_open

(PHP 3>= 3.0.8, PHP 4 )

dba_open -- Open database

Description

resource dba_open ( string path, string mode, string handler [, ...])

dba_open() establishes a database instance for path with mode using handler.

path is commonly a regular path in your filesystem.

mode is "r" for read access, "w" for read/write access to an already existing database, "c" for read/write access and database creation if it doesn't currently exist, and "n" for create, truncate and read/write access.

handler is the name of the handler which shall be used for accessing path. It is passed all optional parameters given to dba_open() and can act on behalf of them.

dba_open() returns a positive handle or FALSE, in the case the open is successful or fails, respectively.

dba_optimize

(PHP 3>= 3.0.8, PHP 4 )

dba_optimize -- Optimize database

Description

bool dba_optimize ( resource handle)

dba_optimize() optimizes the underlying database specified by handle.

handle is a database handle returned by dba_open().

dba_optimize() returns TRUE or FALSE, if the optimization succeeds or fails, respectively.

dba_popen

(PHP 3>= 3.0.8, PHP 4 )

dba_popen -- Open database persistently

Description

resource dba_popen ( string path, string mode, string handler [, ...])

dba_popen() establishes a persistent database instance for path with mode using handler.

path is commonly a regular path in your filesystem.

handler is the name of the handler which shall be used for accessing path. It is passed all optional parameters given to dba_popen() and can act on behalf of them.

dba_popen() returns a positive handle or FALSE, in the case the open is successful or fails, respectively.

dba_replace

(PHP 3>= 3.0.8, PHP 4 )

dba_replace -- Replace or insert entry

Description

bool dba_replace ( string key, string value, resource handle)

dba_replace() replaces or inserts the entry described with key and value into the database specified by handle.

key is the key of the entry to be inserted.

value is the value to be inserted.

handle is a database handle returned by dba_open().

dba_replace() returns TRUE or FALSE, depending on whether it succeeds of fails, respectively.

dba_sync

(PHP 3>= 3.0.8, PHP 4 )

dba_sync -- Synchronize database

Description

bool dba_sync ( resource handle)

dba_sync() synchronizes the database specified by handle. This will probably trigger a physical write to disk, if supported.

handle is a database handle returned by dba_open().

dba_sync() returns TRUE or FALSE, if the synchronization succeeds or fails, respectively.

XVIII. Date and Time functions

Introduction

These functions allow you to get the date and time from the server where your PHP scripts are running. You can use these functions to format the date and time in many different ways.

Note: Please keep in mind that these functions are dependent on the locale settings of your server. Make sure to take daylight saving time and leap years into consideration when working with these functions.

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Table of Contents
checkdate -- Validate a gregorian date
date -- Format a local time/date
getdate -- Get date/time information
gettimeofday -- Get current time
gmdate -- Format a GMT/CUT date/time
gmmktime -- Get UNIX timestamp for a GMT date
gmstrftime -- Format a GMT/CUT time/date according to locale settings
localtime -- Get the local time
microtime -- Return current UNIX timestamp with microseconds
mktime -- Get UNIX timestamp for a date
strftime -- Format a local time/date according to locale settings
strtotime -- Parse about any English textual datetime description into a UNIX timestamp
time -- Return current UNIX timestamp

checkdate

(PHP 3, PHP 4 )

checkdate -- Validate a gregorian date

Description

bool checkdate ( int month, int day, int year)

Returns TRUE if the date given is valid; otherwise returns FALSE. Checks the validity of the date formed by the arguments. A date is considered valid if:

year is between 1 and 32767 inclusive
month is between 1 and 12 inclusive
Day is within the allowed number of days for the given month. Leap years are taken into consideration.

See also mktime() and strtotime().

date

(PHP 3, PHP 4 )

date -- Format a local time/date

Description

string date ( string format [, int timestamp])

Returns a string formatted according to the given format string using the given integer timestamp or the current local time if no timestamp is given.

Note: The valid range of a timestamp is typically from Fri, 13 Dec 1901 20:45:54 GMT to Tue, 19 Jan 2038 03:14:07 GMT. (These are the dates that correspond to the minimum and maximum values for a 32-bit signed integer). On windows this range is limited from 01-01-1970 to 19-01-2038.
To generate a timestamp from a string representation of the date, you may be able to use strtotime(). Additionally, some databases have functions to convert their date formats into timestamps (such as MySQL's UNIX_TIMESTAMP function).

The following characters are recognized in the format string:

a - "am" or "pm"
A - "AM" or "PM"
B - Swatch Internet time
d - day of the month, 2 digits with leading zeros; i.e. "01" to "31"
D - day of the week, textual, 3 letters; e.g. "Fri"
F - month, textual, long; e.g. "January"
g - hour, 12-hour format without leading zeros; i.e. "1" to "12"
G - hour, 24-hour format without leading zeros; i.e. "0" to "23"
h - hour, 12-hour format; i.e. "01" to "12"
H - hour, 24-hour format; i.e. "00" to "23"
i - minutes; i.e. "00" to "59"
I (capital i) - "1" if Daylight Savings Time, "0" otherwise.
j - day of the month without leading zeros; i.e. "1" to "31"
l (lowercase 'L') - day of the week, textual, long; e.g. "Friday"
L - boolean for whether it is a leap year; i.e. "0" or "1"
m - month; i.e. "01" to "12"
M - month, textual, 3 letters; e.g. "Jan"
n - month without leading zeros; i.e. "1" to "12"
O - Difference to Greenwich time in hours; e.g. "+0200"
r - RFC 822 formatted date; e.g. "Thu, 21 Dec 2000 16:01:07 +0200" (added in PHP 4.0.4)
s - seconds; i.e. "00" to "59"
S - English ordinal suffix for the day of the month, 2 characters; i.e. "st", "nd", "rd" or "th"
t - number of days in the given month; i.e. "28" to "31"
T - Timezone setting of this machine; e.g. "EST" or "MDT"
U - seconds since the Unix Epoch (January 1 1970 00:00:00 GMT)
w - day of the week, numeric, i.e. "0" (Sunday) to "6" (Saturday)
W - ISO-8601 week number of year, weeks starting on Monday (added in PHP 4.1.0)
Y - year, 4 digits; e.g. "1999"
y - year, 2 digits; e.g. "99"
z - day of the year; i.e. "0" to "365"
Z - timezone offset in seconds (i.e. "-43200" to "43200"). The offset for timezones west of UTC is always negative, and for those east of UTC is always positive.

Unrecognized characters in the format string will be printed as-is. The "Z" format will always return "0" when using gmdate().

Example 1. date() example
echo date ("l dS of F Y h:i:s A"); echo "July 1, 2000 is on a " . date ("l", mktime(0,0,0,7,1,2000));

You can prevent a recognized character in the format string from being expanded by escaping it with a preceding backslash. If the character with a backslash is already a special sequence, you may need to also escape the backslash.
Example 2. Escaping characters in date()
echo date("l \\t\h\e jS"); // prints something like 'Saturday the 8th'

It is possible to use date() and mktime() together to find dates in the future or the past.
Example 3. date() and mktime() example
$tomorrow = mktime (0,0,0,date("m") ,date("d")+1,date("Y")); $lastmonth = mktime (0,0,0,date("m")-1,date("d"), date("Y")); $nextyear = mktime (0,0,0,date("m"), date("d"), date("Y")+1);

Note: This can be more reliable than simply adding or subtracting the number of seconds in a day or month to a timestamp because of daylight savings time.

Some examples of date() formatting. Note that you should escape any other characters, as any which currently have a special meaning will produce undesirable results, and other characters may be assigned meaning in future PHP versions. When escaping, be sure to use single quotes to prevent characters like \n from becoming newlines.
Example 4. date() Formatting
/* Today is March 10th, 2001, 5:16:18 pm */ $today = date("F j, Y, g:i a"); // March 10, 2001, 5:16 pm $today = date("m.d.y"); // 03.10.01 $today = date("j, n, Y"); // 10, 3, 2001 $today = date("Ymd"); // 20010310 $today = date('h-i-s, j-m-y, it is w Day z '); // 05-16-17, 10-03-01, 1631 1618 6 Fripm01 $today = date('\i\t \i\s \t\h\e jS \d\a\y.'); // It is the 10th day. $today = date("D M j G:i:s T Y"); // Sat Mar 10 15:16:08 MST 2001 $today = date('H:m:s \m \i\s\ \m\o\n\t\h'); // 17:03:17 m is month $today = date("H:i:s"); // 17:16:17

To format dates in other languages, you should use the setlocale() and strftime() functions.

getdate

(PHP 3, PHP 4 )

getdate -- Get date/time information

Description

array getdate ( [int timestamp])

Returns an associative array containing the date information of the timestamp, or the current local time if no timestamp is given, as the following array elements:

"seconds" - seconds
"minutes" - minutes
"hours" - hours
"mday" - day of the month
"wday" - day of the week, numeric : from 0 as Sunday up to 6 as Saturday
"mon" - month, numeric
"year" - year, numeric
"yday" - day of the year, numeric; i.e. "299"
"weekday" - day of the week, textual, full; i.e. "Friday"
"month" - month, textual, full; i.e. "January"

Example 1. getdate() example

$today = getdate(); 
$month = $today['month']; 
$mday = $today['mday']; 
$year = $today['year']; 
echo "$month $mday, $year";

gettimeofday

(PHP 3>= 3.0.7, PHP 4 )

gettimeofday -- Get current time

Description

array gettimeofday ( void)

This is an interface to gettimeofday(2). It returns an associative array containing the data returned from the system call.

"sec" - seconds
"usec" - microseconds
"minuteswest" - minutes west of Greenwich
"dsttime" - type of dst correction

"tm_sec" - seconds
"tm_min" - minutes
"tm_hour" - hour
"tm_mday" - day of the month
"tm_mon" - month of the year, starting with 0 for January
"tm_year" - Years since 1900
"tm_wday" - Day of the week
"tm_yday" - Day of the year
"tm_isdst" - Is daylight savings time in effect

microtime

(PHP 3, PHP 4 )

microtime -- Return current UNIX timestamp with microseconds

Description

string microtime ( void)

Returns the string "msec sec" where sec is the current time measured in the number of seconds since the Unix Epoch (0:00:00 January 1, 1970 GMT), and msec is the microseconds part. This function is only available on operating systems that support the gettimeofday() system call.

Both portions of the string are returned in units of seconds.
Example 1. microtime() example
function getmicrotime(){ list($usec, $sec) = explode(" ",microtime()); return ((float)$usec + (float)$sec); } $time_start = getmicrotime(); for ($i=0; $i < 1000; $i++){ //do nothing, 1000 times } $time_end = getmicrotime(); $time = $time_end - $time_start; echo "Did nothing in $time seconds";

mktime

(PHP 3, PHP 4 )

mktime -- Get UNIX timestamp for a date

Description

int mktime ( int hour, int minute, int second, int month, int day, int year [, int is_dst])

Warning: Note the strange order of arguments, which differs from the order of arguments in a regular UNIX mktime() call and which does not lend itself well to leaving out parameters from right to left (see below). It is a common error to mix these values up in a script.

Returns the Unix timestamp corresponding to the arguments given. This timestamp is a long integer containing the number of seconds between the Unix Epoch (January 1 1970) and the time specified.

Arguments may be left out in order from right to left; any arguments thus omitted will be set to the current value according to the local date and time.

is_dst can be set to 1 if the time is during daylight savings time, 0 if it is not, or -1 (the default) if it is unknown whether the time is within daylight savings time or not. If it's unknown, PHP tries to figure it out itself. This can cause unexpected (but not incorrect) results.

Note: is_dst was added in 3.0.10.

mktime() is useful for doing date arithmetic and validation, as it will automatically calculate the correct value for out-of-range input. For example, each of the following lines produces the string "Jan-01-1998".
Example 1. mktime() example
echo date ("M-d-Y", mktime (0,0,0,12,32,1997)); echo date ("M-d-Y", mktime (0,0,0,13,1,1997)); echo date ("M-d-Y", mktime (0,0,0,1,1,1998)); echo date ("M-d-Y", mktime (0,0,0,1,1,98));
Year may be a two or four digit value, with values between 0-69 mapping to 2000-2069 and 70-99 to 1970-1999 (on systems where time_t is a 32bit signed integer, as most common today, the valid range for year is somewhere between 1902 and 2037).

The last day of any given month can be expressed as the "0" day of the next month, not the -1 day. Both of the following examples will produce the string "The last day in Feb 2000 is: 29".
Example 2. Last day of next month
$lastday = mktime (0,0,0,3,0,2000); echo strftime ("Last day in Feb 2000 is: %d", $lastday); $lastday = mktime (0,0,0,4,-31,2000); echo strftime ("Last day in Feb 2000 is: %d", $lastday);

Date with year, month and day equal to zero is considered illegal (otherwise it what be regarded as 30.11.1999, which would be strange behavior).

strftime

(PHP 3, PHP 4 )

strftime -- Format a local time/date according to locale settings

Description

string strftime ( string format [, int timestamp])

Returns a string formatted according to the given format string using the given timestamp or the current local time if no timestamp is given. Month and weekday names and other language dependent strings respect the current locale set with setlocale().

The following conversion specifiers are recognized in the format string:

%a - abbreviated weekday name according to the current locale
%A - full weekday name according to the current locale
%b - abbreviated month name according to the current locale
%B - full month name according to the current locale
%c - preferred date and time representation for the current locale
%C - century number (the year divided by 100 and truncated to an integer, range 00 to 99)
%d - day of the month as a decimal number (range 01 to 31)
%D - same as %m/%d/%y
%e - day of the month as a decimal number, a single digit is preceded by a space (range ' 1' to '31')
%g - like %G, but without the century.
%G - The 4-digit year corresponding to the ISO week number (see %V). This has the same format and value as %Y, except that if the ISO week number belongs to the previous or next year, that year is used instead.
%h - same as %b
%H - hour as a decimal number using a 24-hour clock (range 00 to 23)
%I - hour as a decimal number using a 12-hour clock (range 01 to 12)
%j - day of the year as a decimal number (range 001 to 366)
%m - month as a decimal number (range 01 to 12)
%M - minute as a decimal number
%n - newline character
%p - either `am' or `pm' according to the given time value, or the corresponding strings for the current locale
%r - time in a.m. and p.m. notation
%R - time in 24 hour notation
%S - second as a decimal number
%t - tab character
%T - current time, equal to %H:%M:%S
%u - weekday as a decimal number [1,7], with 1 representing Monday
Warning
Sun Solaris seems to start with Sunday as 1 although ISO 9889:1999 (the current C standard) clearly specifies that it should be Monday.
%U - week number of the current year as a decimal number, starting with the first Sunday as the first day of the first week
%V - The ISO 8601:1988 week number of the current year as a decimal number, range 01 to 53, where week 1 is the first week that has at least 4 days in the current year, and with Monday as the first day of the week. (Use %G or %g for the year component that corresponds to the week number for the specified timestamp.)
%W - week number of the current year as a decimal number, starting with the first Monday as the first day of the first week
%w - day of the week as a decimal, Sunday being 0
%x - preferred date representation for the current locale without the time
%X - preferred time representation for the current locale without the date
%y - year as a decimal number without a century (range 00 to 99)
%Y - year as a decimal number including the century
%Z - time zone or name or abbreviation
%% - a literal `%' character

Note: Not all conversion specifiers may be supported by your C library, in which case they will not be supported by PHP's strftime(). This means that e.g. %e, %T and %D (there might be more) will not work on Windows.

Example 1. strftime() example

setlocale (LC_TIME, "C");
print (strftime ("%A in Finnish is "));
setlocale (LC_TIME, "fi_FI");
print (strftime ("%A, in French "));
setlocale (LC_TIME, "fr_FR");
print (strftime ("%A and in German "));
setlocale (LC_TIME, "de_DE");
print (strftime ("%A.\n"));

This example works if you have the respective locales installed in your system.

strtotime

(PHP 3>= 3.0.12, PHP 4 )

strtotime -- Parse about any English textual datetime description into a UNIX timestamp

Description

int strtotime ( string time [, int now])

The function expects to be given a string containing an English date format and will try to parse that format into a UNIX timestamp relative to the timestamp given in now, or the current time if none is supplied. Upon failure, -1 is returned.

Because strtotime() behaves according to GNU date syntax, have a look at the GNU manual page titled Date Input Formats. Described there is valid syntax for the time parameter.

Example 1. strtotime() examples
echo strtotime ("now"), "\n"; echo strtotime ("10 September 2000"), "\n"; echo strtotime ("+1 day"), "\n"; echo strtotime ("+1 week"), "\n"; echo strtotime ("+1 week 2 days 4 hours 2 seconds"), "\n"; echo strtotime ("next Thursday"), "\n"; echo strtotime ("last Monday"), "\n";

Example 2. Checking for failure
$str = 'Not Good'; if (($timestamp = strtotime($str)) === -1) { echo "The string ($str) is bogus"; } else { echo "$str == ". date('l dS of F Y h:i:s A',$timestamp); }

Note: The valid range of a timestamp is typically from Fri, 13 Dec 1901 20:45:54 GMT to Tue, 19 Jan 2038 03:14:07 GMT. (These are the dates that correspond to the minimum and maximum values for a 32-bit signed integer.)

time

(PHP 3, PHP 4 )

time -- Return current UNIX timestamp

Description

int time ( void)

Returns the current time measured in the number of seconds since the Unix Epoch (January 1 1970 00:00:00 GMT).

XIX. dBase functions

Introduction

These functions allow you to access records stored in dBase-format (dbf) databases.

There is no support for indexes or memo fields. There is no support for locking, too. Two concurrent webserver processes modifying the same dBase file will very likely ruin your database.

dBase files are simple sequential files of fixed length records. Records are appended to the end of the file and delete records are kept until you call dbase_pack().

We recommend that you do not use dBase files as your production database. Choose any real SQL server instead; MySQL or Postgres are common choices with PHP. dBase support is here to allow you to import and export data to and from your web database, because the file format is commonly understood by Windows spreadsheets and organizers.

Installation

In order to use these functions, you must compile PHP with the --enable-dbase option.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Table of Contents
dbase_add_record -- Add a record to a dBase database
dbase_close -- Close a dBase database
dbase_create -- Creates a dBase database
dbase_delete_record -- Deletes a record from a dBase database
dbase_get_record_with_names -- Gets a record from a dBase database as an associative array
dbase_get_record -- Gets a record from a dBase database
dbase_numfields -- Find out how many fields are in a dBase database
dbase_numrecords -- Find out how many records are in a dBase database
dbase_open -- Opens a dBase database
dbase_pack -- Packs a dBase database
dbase_replace_record -- Replace a record in a dBase database

dbase_add_record

array dbase_get_record_with_names ( int dbase_identifier, int record)

Returns the data from record in an associative array. The array also includes an associative member named 'deleted' which is set to 1 if the record has been marked for deletion (see dbase_delete_record()).

Each field is converted to the appropriate PHP type, except:

Dates are left as strings
Integers that would have caused an overflow (> 32 bits) are returned as strings

dbase_get_record

(PHP 3, PHP 4 )

dbase_get_record -- Gets a record from a dBase database

Description

array dbase_get_record ( int dbase_identifier, int record)

Returns the data from record in an array. The array is indexed starting at 0, and includes an associative member named 'deleted' which is set to 1 if the record has been marked for deletion (see dbase_delete_record().

Each field is converted to the appropriate PHP type, except:

Dates are left as strings
Integers that would have caused an overflow (> 32 bits) are returned as strings

Returns a dbase_identifier for the opened database, or FALSE if the database couldn't be opened.

Note: When safe mode is enabled, PHP checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.

dbase_pack

(PHP 3, PHP 4 )

dbase_pack -- Packs a dBase database

Description

bool dbase_pack ( int dbase_identifier)

Packs the specified database (permanently deleting all records marked for deletion using dbase_delete_record()).

dbase_replace_record

(PHP 3>= 3.0.11, PHP 4 )

dbase_replace_record -- Replace a record in a dBase database

Description

bool dbase_replace_record ( int dbase_identifier, array record, int dbase_record_number)

Replaces the data associated with the record record_number with the data in the record in the database. If the number of items in the supplied record is not equal to the number of fields in the database, the operation will fail and FALSE will be returned.

dbase_record_number is an integer which spans from 1 to the number of records in the database (as returned by dbase_numrecords()).

XX. DBM Functions

Introduction

These functions allow you to store records stored in a dbm-style database. This type of database (supported by the Berkeley DB, GDBM, and some system libraries, as well as a built-in flatfile library) stores key/value pairs (as opposed to the full-blown records supported by relational databases).

Note: However, dbm support is deprecated and you are encourged to use the Database (dbm-style) abstraction layer functions instead.

Requirements

To use this functions you have to compile PHP with support for an underlying database. See the list of supported Databases.

Installation

In order to use these functions, you must compile PHP with dbm support by using the --with-db option. In addtion you must ensure support for an underlying database or you can use some sytem libraries.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

The function dbmopen() returns an database identifier which is used by the other dbm-functions.

Predefined Constants

This extension has no constants defined.

Examples

Example 1. DBM example
$dbm = dbmopen ("lastseen", "w"); if (dbmexists ($dbm, $userid)) { $last_seen = dbmfetch ($dbm, $userid); } else { dbminsert ($dbm, $userid, time()); } do_stuff(); dbmreplace ($dbm, $userid, time()); dbmclose ($dbm);

Table of Contents
dblist -- Describes the DBM-compatible library being used
dbmclose -- Closes a dbm database
dbmdelete -- Deletes the value for a key from a DBM database
dbmexists -- Tells if a value exists for a key in a DBM database
dbmfetch -- Fetches a value for a key from a DBM database
dbmfirstkey -- Retrieves the first key from a DBM database
dbminsert -- Inserts a value for a key in a DBM database
dbmnextkey -- Retrieves the next key from a DBM database
dbmopen -- Opens a DBM database
dbmreplace -- Replaces the value for a key in a DBM database

dblist

(PHP 3, PHP 4 )

dblist -- Describes the DBM-compatible library being used

Description

string dblist ( void)

dbmclose

(PHP 3, PHP 4 )

dbmclose -- Closes a dbm database

Description

bool dbmclose ( resource dbm_identifier)

Unlocks and closes the specified database.

dbmdelete

(PHP 3, PHP 4 )

dbmdelete -- Deletes the value for a key from a DBM database

Description

bool dbmdelete ( resource dbm_identifier, string key)

int dbminsert ( resource dbm_identifier, string key, string value)

Adds the value to the database with the specified key.

Returns -1 if the database was opened read-only, 0 if the insert was successful, and 1 if the specified key already exists. (To replace the value, use dbmreplace().)

dbmnextkey

int dbmreplace ( resource dbm_identifier, string key, string value)

Replaces the value for the specified key in the database.

This will also add the key to the database if it didn't already exist.

XXI. dbx functions

Introduction

The dbx module is a database abstraction layer (db 'X', where 'X' is a supported database). The dbx functions allow you to access all supported databases using a single calling convention. The dbx-functions themselves do not interface directly to the databases, but interface to the modules that are used to support these databases.

Requirements

To be able to use a database with the dbx-module, the module must be either linked or loaded into PHP, and the database module must be supported by the dbx-module. Currently, following databases are supported, but others will follow (soon, I hope :-):

FrontBase (available from PHP 4.1.0).
Microsoft SQL Server
MySQL
ODBC
PostgreSQL
Sybase-CT (available from PHP 4.2.0).

Documentation for adding additional database support to dbx can be found at http://www.guidance.nl/php/dbx/doc/.

Installation

In order to have these functions available, you must compile PHP with dbx support by using the --enable-dbx option and all options for the databases that will be used, e.g. for MySQL you must also specify --with-mysql=[DIR]. To get other supported databases to work with the dbx-module refer to their specific documentation.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

There are two resource types used in the dbx module. The first one is the link-object for a database connection, the second a result-object which helds the result of a query.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

DBX_MYSQL (integer)
DBX_ODBC (integer)
DBX_PGSQL (integer)
DBX_MSSQL (integer)
DBX_FBSQL (integer)
DBX_OCI8 (integer)
DBX_SYBASECT (integer)
DBX_PERSISTENT (integer)
DBX_RESULT_INFO (integer)
DBX_RESULT_INDEX (integer)
DBX_RESULT_ASSOC (integer)
DBX_CMP_NATIVE (integer)
DBX_CMP_TEXT (integer)
DBX_CMP_NUMBER (integer)
DBX_CMP_ASC (integer)
DBX_CMP_DESC (integer)

Table of Contents
dbx_close -- Close an open connection/database
dbx_compare -- Compare two rows for sorting purposes
dbx_connect -- Open a connection/database
dbx_error -- Report the error message of the latest function call in the module (not just in the connection)
dbx_query -- Send a query and fetch all results (if any)
dbx_sort -- Sort a result from a dbx_query by a custom sort function

dbx_close

(PHP 4 >= 4.0.6)

dbx_close -- Close an open connection/database

Description

bool dbx_close ( object link_identifier)

Returns TRUE on success or FALSE on failure.

Example 1. dbx_close() example

<?php
$link = dbx_connect(DBX_MYSQL, "localhost", "db", "username", "password")
    or die ("Could not connect");

print("Connected successfully");
dbx_close($link);
?>

Note: Always refer to the module-specific documentation as well.

dbx_compare

(PHP 4 >= 4.1.0)

dbx_compare -- Compare two rows for sorting purposes

Description

int dbx_compare ( array row_a, array row_b, string column_key [, int flags])

dbx_compare() returns 0 if the row_a[$column_key] is equal to row_b[$column_key], and 1 or -1 if the former is greater or is smaller than the latter one, respectively, or vice versa if the flag is set to DBX_CMP_DESC. dbx_compare() is a helper function for dbx_sort() to ease the make and use of the custom sorting function.

The flags can be set to specify comparison direction:

DBX_CMP_ASC - ascending order
DBX_CMP_DESC - descending order

and the preferred comparison type:

DBX_CMP_NATIVE - no type conversion
DBX_CMP_TEXT - compare items as strings
DBX_CMP_NUMBER - compare items numerically

One of the direction and one of the type constant can be combined with bitwise OR operator (|). The default value for the flags parameter is DBX_CMP_ASC | DBX_CMP_NATIVE.

Example 1. dbx_compare() example

<?php
function user_re_order ($a, $b) {
    $rv = dbx_compare ($a, $b, "parentid", DBX_CMP_DESC);
    if ( !$rv ) {
        $rv = dbx_compare ($a, $b, "id", DBX_CMP_NUMBER);
    }
    return $rv;
}

$link   = dbx_connect (DBX_ODBC, "", "db", "username", "password")
    or die ("Could not connect");

$result = dbx_query ($link, "SELECT id, parentid, description FROM table ORDER BY id");
    // data in $result is now ordered by id

dbx_sort ($result, "user_re_order");
    // date in $result is now ordered by parentid (descending), then by id

dbx_close ($link);
?>

dbx_connect

(PHP 4 >= 4.0.6)

dbx_connect -- Open a connection/database

Description

object dbx_connect ( mixed module, string host, string database, string username, string password [, int persistent])

dbx_connect() returns an object on success, FALSE on error. If a connection has been made but the database could not be selected, the connection is closed and FALSE is returned. The persistent parameter can be set to DBX_PERSISTENT, if so, a persistent connection will be created.

The module parameter can be either a string or a constant, though the latter form is preferred. The possible values are given below, but keep in mind that they only work if the module is actually loaded.

DBX_MYSQL or "mysql"
DBX_ODBC or "odbc"
DBX_PGSQL or "pgsql"
DBX_MSSQL or "mssql"
DBX_FBSQL or "fbsql" (available from PHP 4.1.0)
DBX_SYBASECT or "sybase_ct" (available from PHP 4.2.0)

The host, database, username and password parameters are expected, but not always used depending on the connect functions for the abstracted module.

The returned object has three properties:

database

It is the name of the currently selected database.

handle

It is a valid handle for the connected database, and as such it can be used in module-specific functions (if required).

$link = dbx_connect (DBX_MYSQL, "localhost", "db", "username", "password");
mysql_close ($link->handle); // dbx_close($link) would be better here

module

It is used internally by dbx only, and is actually the module number mentioned above.

Example 1. dbx_connect() example
<?php $link = dbx_connect (DBX_ODBC, "", "db", "username", "password", DBX_PERSISTENT) or die ("Could not connect"); print ("Connected successfully"); dbx_close ($link); ?>

Note: Always refer to the module-specific documentation as well.

dbx_error

(PHP 4 >= 4.0.6)

dbx_error -- Report the error message of the latest function call in the module (not just in the connection)

Description

string dbx_error ( object link_identifier)

dbx_error() returns a string containing the error message from the last function call of the abstracted module (e.g. mysql module). If there are multiple connections in the same module, just the last error is given. If there are connections on different modules, the latest error is returned for the module specified by the link_identifier parameter.

Example 1. dbx_error() example

<?php
$link   = dbx_connect(DBX_MYSQL, "localhost", "db", "username", "password")
    or die ("Could not connect");

$result = dbx_query($link, "select id from non_existing_table");
if ( $result == 0 ) {
    echo dbx_error ($link);
}
dbx_close ($link);
?>

Note: Always refer to the module-specific documentation as well.
The error message for Microsoft SQL Server is actually the result of the mssql_get_last_message() function.

dbx_query

(PHP 4 >= 4.0.6)

dbx_query -- Send a query and fetch all results (if any)

Description

object dbx_query ( object link_identifier, string sql_statement [, long flags])

dbx_query() returns an object or 1 on success, and 0 on failure. The result object is returned only if the query given in sql_statement produces a result set.

Example 1. How to handle the returned value

<?php
$link   = dbx_connect(DBX_ODBC, "", "db", "username", "password")
    or die("Could not connect");

$result = dbx_query($link, 'SELECT id, parentid, description FROM table');

if ( is_object($result) ) {
    // ... do some stuff here, see detailed examples below ...
    // first, print out field names and types 
    // then, draw a table filled with the returned field values
}
else if ( $result == 1 ) {
    echo("Query executed successfully, but no result set returned");
}
else {
    exit("Query failed");
}

dbx_close($link);
?>

The flags parameter is used to control the amount of information that is returned. It may be any combination of the following constants with the bitwise OR operator (|):

DBX_RESULT_INDEX

It is always set, that is, the returned object has a data property which is a 2 dimensional array indexed numerically. For example, in the expression data[2][3] 2 stands for the row (or record) number and 3 stands for the column (or field) number. The first row and column are indexed at 0.

If DBX_RESULT_ASSOC is also specified, the returning object contains the information related to DBX_RESULT_INFO too, even if it was not specified.

DBX_RESULT_INFO

It provides info about columns, such as field names and field types.

DBX_RESULT_ASSOC

It effects that the field values can be accessed with the respective column names used as keys to the returned object's data property.

Associated results are actually references to the numerically indexed data, so modifying data[0][0] causes that data[0]['field_name_for_first_column'] is modified as well.

Note that DBX_RESULT_INDEX is always used, regardless of the actual value of flags parameter. This means that the following combinations is effective only:

DBX_RESULT_INDEX
DBX_RESULT_INDEX | DBX_RESULT_INFO
DBX_RESULT_INDEX | DBX_RESULT_INFO | DBX_RESULT_ASSOC - this is the default, if flags is not specified.

The returing object has four or five properties depending on flags:

handle

It is a valid handle for the connected database, and as such it can be used in module specific functions (if required).

$result = dbx_query ($link, "SELECT id FROM table");
mysql_field_len ($result->handle, 0);

cols and rows

These contain the number of columns (or fields) and rows (or records) respectively.

$result = dbx_query ($link, 'SELECT id FROM table');
echo $result->rows; // number of records
echo $result->cols; // number of fields

info (optional)

It is returned only if either DBX_RESULT_INFO or DBX_RESULT_ASSOC is specified in the flags parameter. It is a 2 dimensional array, that has two named rows (name and type) to retrieve column information.

Example 2. lists each field's name and type

$result = dbx_query ($link, 'SELECT id FROM table',
                     DBX_RESULT_INDEX | DBX_RESULT_INFO);

for ($i = 0; $i < $result->cols; $i++ ) {
    echo $result->info['name'][$i] . "\n";
    echo $result->info['type'][$i] . "\n";  
}

data

This property contains the actual resulting data, possibly associated with column names as well depending on flags. If DBX_RESULT_ASSOC is set, it is possible to use $result->data[2]["field_name"].

Example 3. outputs the content of data property into HTML table

$result = dbx_query ($link, 'SELECT id, parentid, description FROM table');

echo "<table>\n";
foreach ( $result->data as $row ) {
    echo "<tr>\n";
    foreach ( $row as $field ) {
        echo "<td>$field</td>";
    }
    echo "</tr>\n";
}
echo "</table>\n";

Note: Always refer to the module-specific documentation as well.

dbx_sort

(PHP 4 >= 4.0.6)

dbx_sort -- Sort a result from a dbx_query by a custom sort function

Description

bool dbx_sort ( object result, string user_compare_function)

Returns TRUE on success or FALSE on failure.

Note: It is always better to use ORDER BY SQL clause instead of dbx_sort(), if possible.

Example 1. dbx_sort() example

<?php
function user_re_order ($a, $b) {
    $rv = dbx_compare ($a, $b, "parentid", DBX_CMP_DESC);
    if ( !$rv ) {
        $rv = dbx_compare ($a, $b, "id", DBX_CMP_NUMBER);
    }
    return $rv;
}

$link   = dbx_connect (DBX_ODBC, "", "db", "username", "password")
    or die ("Could not connect");

$result = dbx_query ($link, "SELECT id, parentid, description FROM tbl ORDER BY id");
    // data in $result is now ordered by id

dbx_sort ($result, "user_re_order");
    // data in $result is now ordered by parentid (descending), then by id

dbx_close ($link);
?>

XXII. DB++ Functions

Warning

This extension is EXPERIMENTAL. The behaviour of this extension -- including the names of its functions and anything else documented about this extension -- may change without notice in a future release of PHP. Use this extension at your own risk.

Introduction

db++, made by the German company Concept asa, is a relational database system with high performance and low memory and disk usage in mind. While providing SQL as an additional language interface, it is not really a SQL database in the first place but provides its own AQL query language which is much more influenced by the relational algebra then SQL is.

Concept asa always had an interest in supporting open source languages, db++ has had Perl and Tcl call interfaces for years now and uses Tcl as its internal stored procedure language.

Requirements

This extension relies on external client libraries so you have to have a db++ client installed on the system you want to use this extension on.

Concept asa provides db++ Demo versions and documentation for Linux, some other UNIX versions. There is also a Windows version of db++, but this extension doesn't support it (yet).

Installation

In order to build this extension yourself you need the db++ client libraries and header files to be installed on your system (these are included in the db++ installation archives by default). You have to run configure with option --with-dbplus to build this extension.

configure looks for the client libraries and header files under the default paths /usr/dbplus, /usr/local/dbplus and /opt/dblus. If you have installed db++ in a different place you have add the installation path to the configure option like this: --with-dbplus=/your/installation/path.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

dbplus_relation

Most db++ functions operate on or return dbplus_relation resources. A dbplus_relation is a handle to a stored relation or a relation generated as the result of a query.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

db++ error codes

Table 1. DB++ Error Codes

PHP Constant	db++ constant	meaning
`DBPLUS_ERR_NOERR` (integer)	ERR_NOERR	Null error condition
`DBPLUS_ERR_DUPLICATE` (integer)	ERR_DUPLICATE	Tried to insert a duplicate tuple
`DBPLUS_ERR_EOSCAN` (integer)	ERR_EOSCAN	End of scan from rget()
`DBPLUS_ERR_EMPTY` (integer)	ERR_EMPTY	Relation is empty (server)
`DBPLUS_ERR_CLOSE` (integer)	ERR_CLOSE	The server can't close
`DBPLUS_ERR_WLOCKED` (integer)	ERR_WLOCKED	The record is write locked
`DBPLUS_ERR_LOCKED` (integer)	ERR_LOCKED	Relation was already locked
`DBPLUS_ERR_NOLOCK` (integer)	ERR_NOLOCK	Relation cannot be locked
`DBPLUS_ERR_READ` (integer)	ERR_READ	Read error on relation
`DBPLUS_ERR_WRITE` (integer)	ERR_WRITE	Write error on relation
`DBPLUS_ERR_CREATE` (integer)	ERR_CREATE	Create() system call failed
`DBPLUS_ERR_LSEEK` (integer)	ERR_LSEEK	Lseek() system call failed
`DBPLUS_ERR_LENGTH` (integer)	ERR_LENGTH	Tuple exceeds maximum length
`DBPLUS_ERR_OPEN` (integer)	ERR_OPEN	Open() system call failed
`DBPLUS_ERR_WOPEN` (integer)	ERR_WOPEN	Relation already opened for writing
`DBPLUS_ERR_MAGIC` (integer)	ERR_MAGIC	File is not a relation
`DBPLUS_ERR_VERSION` (integer)	ERR_VERSION	File is a very old relation
`DBPLUS_ERR_PGSIZE` (integer)	ERR_PGSIZE	Relation uses a different page size
`DBPLUS_ERR_CRC` (integer)	ERR_CRC	Invalid crc in the superpage
`DBPLUS_ERR_PIPE` (integer)	ERR_PIPE	Piped relation requires lseek()
`DBPLUS_ERR_NIDX` (integer)	ERR_NIDX	Too many secondary indices
`DBPLUS_ERR_MALLOC` (integer)	ERR_MALLOC	Malloc() call failed
`DBPLUS_ERR_NUSERS` (integer)	ERR_NUSERS	Error use of max users
`DBPLUS_ERR_PREEXIT` (integer)	ERR_PREEXIT	Caused by invalid usage
`DBPLUS_ERR_ONTRAP` (integer)	ERR_ONTRAP	Caused by a signal
`DBPLUS_ERR_PREPROC` (integer)	ERR_PREPROC	Error in the preprocessor
`DBPLUS_ERR_DBPARSE` (integer)	ERR_DBPARSE	Error in the parser
`DBPLUS_ERR_DBRUNERR` (integer)	ERR_DBRUNERR	Run error in db
`DBPLUS_ERR_DBPREEXIT` (integer)	ERR_DBPREEXIT	Exit condition caused by prexit() * procedure
`DBPLUS_ERR_WAIT` (integer)	ERR_WAIT	Wait a little (Simple only)
`DBPLUS_ERR_CORRUPT_TUPLE` (integer)	ERR_CORRUPT_TUPLE	A client sent a corrupt tuple
`DBPLUS_ERR_WARNING0` (integer)	ERR_WARNING0	The Simple routines encountered a non fatal error which was corrected
`DBPLUS_ERR_PANIC` (integer)	ERR_PANIC	The server should not really die but after a disaster send ERR_PANIC to all its clients
`DBPLUS_ERR_FIFO` (integer)	ERR_FIFO	Can't create a fifo
`DBPLUS_ERR_PERM` (integer)	ERR_PERM	Permission denied
`DBPLUS_ERR_TCL` (integer)	ERR_TCL	TCL_error
`DBPLUS_ERR_RESTRICTED` (integer)	ERR_RESTRICTED	Only two users
`DBPLUS_ERR_USER` (integer)	ERR_USER	An error in the use of the library by an application programmer
`DBPLUS_ERR_UNKNOWN` (integer)	ERR_UNKNOWN

Table of Contents
dbplus_add -- Add a tuple to a relation
dbplus_aql -- Perform AQL query
dbplus_chdir -- Get/Set database virtual current directory
dbplus_close -- Close a relation
dbplus_curr -- Get current tuple from relation
dbplus_errcode -- Get error string for given errorcode or last error
dbplus_errno -- Get error code for last operation
dbplus_find -- Set a constraint on a relation
dbplus_first -- Get first tuple from relation
dbplus_flush -- Flush all changes made on a relation
dbplus_freealllocks -- Free all locks held by this client
dbplus_freelock -- Release write lock on tuple
dbplus_freerlocks -- Free all tuple locks on given relation
dbplus_getlock -- Get a write lock on a tuple
dbplus_getunique -- Get a id number unique to a relation
dbplus_info -- ???
dbplus_last -- Get last tuple from relation
dbplus_lockrel -- Request write lock on relation
dbplus_next -- Get next tuple from relation
dbplus_open -- Open relation file
dbplus_prev -- Get previous tuple from relation
dbplus_rchperm -- Change relation permissions
dbplus_rcreate -- Creates a new DB++ relation
dbplus_rcrtexact -- Creates an exact but empty copy of a relation including indices
dbplus_rcrtlike -- Creates an empty copy of a relation with default indices
dbplus_resolve -- Resolve host information for relation
dbplus_restorepos -- ???
dbplus_rkeys -- Specify new primary key for a relation
dbplus_ropen -- Open relation file local
dbplus_rquery -- Perform local (raw) AQL query
dbplus_rrename -- Rename a relation
dbplus_rsecindex -- Create a new secondary index for a relation
dbplus_runlink -- Remove relation from filesystem
dbplus_rzap -- Remove all tuples from relation
dbplus_savepos -- ???
dbplus_setindex -- ???
dbplus_setindexbynumber -- ???
dbplus_sql -- Perform SQL query
dbplus_tcl -- Execute TCL code on server side
dbplus_tremove -- Remove tuple and return new current tuple
dbplus_undo -- ???
dbplus_undoprepare -- ???
dbplus_unlockrel -- Give up write lock on relation
dbplus_unselect -- Remove a constraint from relation
dbplus_update -- Update specified tuple in relation
dbplus_xlockrel -- Request exclusive lock on relation
dbplus_xunlockrel -- Free exclusive lock on relation

dbplus_add

(4.1.0 - 4.2.3 only)

dbplus_add -- Add a tuple to a relation

Description

int dbplus_add ( resource relation, array tuple)

Warning

This function will add a tuple to a relation. The tuple data is an array of attribute/value pairs to be inserted into the given relation. After successful execution the tuple array will contain the complete data of the newly created tuple, including all implicitly set domain fields like sequences.

The function will return zero (aka. DBPLUS_ERR_NOERR) on success or a db++ error code on failure. See dbplus_errcode() or the introduction to this chapter for more information on db++ error codes.

dbplus_aql

(4.1.0 - 4.2.3 only)

dbplus_aql -- Perform AQL query

Description

resource dbplus_aql ( string query [, string server [, string dbpath]])

Warning

resource dbplus_open ( string name)

resource dbplus_rcreate ( string name, mixed domlist [, boolean overwrite])

resource dbplus_rkeys ( resource relation, mixed domlist)

resource dbplus_rsecindex ( resource relation, mixed domlist, int type)

int dbplus_tcl ( int sid, string script)

No external libraries are needed to build this extension.

Installation

To get these functions to work, you have to configure PHP with --enable-dio.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

One resource type is defined by this extension: a file descriptor returnded by dio_open().

Predefined Constants

This extension has no constants defined.

Table of Contents
dio_close -- Closes the file descriptor given by fd
dio_fcntl -- Performs a c library fcntl on fd
dio_open -- Opens a new filename with specified permissions of flags and creation permissions of mode
dio_read -- Reads n bytes from fd and returns them, if n is not specified, reads 1k block
dio_seek -- Seeks to pos on fd from whence
dio_stat -- Gets stat information about the file descriptor fd
dio_tcsetattr -- Sets terminal attributes and baud rate for a serial port
dio_truncate -- Truncates file descriptor fd to offset bytes
dio_write -- Writes data to fd with optional truncation at length

dio_close

(PHP 4 >= 4.2.0)

dio_close -- Closes the file descriptor given by fd

Description

void dio_close ( resource fd)

The function dio_close() closes the file descriptor resource.

dio_fcntl

(PHP 4 >= 4.2.0)

dio_fcntl -- Performs a c library fcntl on fd

Description

mixed dio_fcntl ( resource fd, int cmd [, mixed arg])

The dio_fcntl() function performs the operation specified by cmd on the file descriptor fd. Some commands require additional arguments args to be supplied.

arg is an associative array, when cmd is F_SETLK or F_SETLLW, with the following keys:

"start" - offset where lock begins
"length" - size of locked area. zero means to end of file
"wenth" - Where l_start is relative to: can be SEEK_SET, SEEK_END and SEEK_CUR
"type" - type of lock: can be F_RDLCK (read lock), F_WRLCK (write lock) or F_UNLCK (unlock)

cmd can be one of the following operations:

F_SETLK - Lock is set or cleared. If the lock is held by someone else dio_fcntl() returns -1.
F_SETLKW - like F_SETLK, but in case the lock is held by someone else, dio_fcntl() waits until the lock is released.
F_GETLK - dio_fcntl() returns an associative array (as described above) if someone else prevents lock. If there is no obstruction key "type" will set to F_UNLCK.
F_DUPFD - finds the lowest numbered available file descriptor greater or equal than arg and returns them.
F_SETFL - Sets the file descriptors flags to the value specified by arg, Which can be O_APPEND,O_NONBLOCK or O_ASYNC . To use O_ASYNC you will need to use the pcntl extension.

dio_open

(PHP 4 >= 4.2.0)

dio_open -- Opens a new filename with specified permissions of flags and creation permissions of mode

Description

resource dio_open ( string filename, int flags [, int mode])

dio_open() opens a file and returns a new file descriptor for it, or -1 if any error occurred. If flags is O_CREAT, optional third parameter mode will set the mode of the file (creation permissions). The flags parameter can be one of the following options:

O_RDONLY - opens the file for read access
O_WRONLY - opens the file for write access
O_RDWR - opens the file for both reading and writing

The flags parameter can also include any combination of the following flags:

O_CREAT - creates the file, if it doesn't already exist
O_EXCL - if both, O_CREAT and O_EXCL are set, dio_open() fails, if file already exists
O_TRUNC - if file exists, and its opened for write access, file will be truncated to zero length.
O_APPEND - write operations write data at the end of file
O_NONBLOCK - sets non blocking mode

dio_read

(PHP 4 >= 4.2.0)

dio_read -- Reads n bytes from fd and returns them, if n is not specified, reads 1k block

Description

string dio_read ( resource fd [, int n])

The function dio_read() reads and returns n bytes from file with descriptor resource. If n is not specified, dio_read() reads 1K sized block and returns them.

dio_seek

(PHP 4 >= 4.2.0)

dio_seek -- Seeks to pos on fd from whence

Description

int dio_seek ( resource fd, int pos, int whence)

The function dio_seek() is used to change the file position of the file with descriptor resource. The parameter whence specifies how the position pos should be interpreted:

SEEK_SET - specifies that pos is specified from the beginning of the file
SEEK_CUR - Specifies that pos is a count of characters from the current file position. This count may be positive or negative
SEEK_END - Specifies that pos is a count of characters from the end of the file. A negative count specifies a position within the current extent of the file; a positive count specifies a position past the current end. If you set the position past the current end, and actually write data, you will extend the file with zeros up to that position

dio_stat

(PHP 4 >= 4.2.0)

dio_stat -- Gets stat information about the file descriptor fd

Description

array dio_stat ( resource fd)

Function dio_stat() returns information about the file with file descriptor fd. dio_stat() returns an associative array with the following keys:

"device" - device
"inode" - inode
"mode" - mode
"nlink" - number of hard links
"uid" - user id
"gid" - group id
"device_type" - device type (if inode device)
"size" - total size in bytes
"blocksize" - blocksize
"blocks" - number of blocks allocated
"atime" - time of last access
"mtime" - time of last modification
"ctime" - time of last change

On error dio_stat() returns NULL.

dio_tcsetattr

(PHP 4 CVS only)

dio_tcsetattr -- Sets terminal attributes and baud rate for a serial port

Description

dio_tcsetattr ( resource fd, array options)

The function dio_tcsetattr() sets the terminal attributes and baud rate of the open resource. The currently available options are

'baud' - baud rate of the port - can be 38400,19200,9600,4800,2400,1800,1200,600,300,200,150,134,110,75 or 50, default value is 9600
'bits' - data bits - can be 8,7,6 or 5 default value is 8
'stop' - stop bits - can be 1 or 2 default value is 1
'parity' - can be 0,1 or 2 default value is 0

Example 1. Setting the baud rate on a serial port

<?php

$fd = dio_open('/dev/ttyS0', O_RDWR | O_NOCTTY | O_NONBLOCK);

dio_fcntl($fd,F_SETFL, O_SYNC );

dio_tcsetattr($fd, array(
  'baud' => 9600,
  'bits' => 8,
  'stop'  =>1,
  'parity' => 0
)); 

while (1) {

  $data = dio_read($fd,256);

  if ($data) {
      echo $data;
  }
} 

?>

Note: This function was introduced in PHP 4.3.0.

dio_truncate

(PHP 4 >= 4.2.0)

dio_truncate -- Truncates file descriptor fd to offset bytes

Description

bool dio_truncate ( resource fd, int offset)

Function dio_truncate() causes the file referenced by fd to be truncated to at most offset bytes in size. If the file previously was larger than this size, the extra data is lost. If the file previously was shorter, it is unspecified whether the file is left unchanged or is extended. In the latter case the extended part reads as zero bytes. Returns 0 on success, otherwise -1.

dio_write

(PHP 4 >= 4.2.0)

dio_write -- Writes data to fd with optional truncation at length

Description

int dio_write ( resource fd, string data [, int len])

The function dio_write() writes up to len bytes from data to file fd. If len is not specified, dio_write() writes all data to the specified file. dio_write() returns the number of bytes written to fd.

XXIV. Directory functions

Introduction

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

Predefined Constants

This extension has no constants defined.

chdir

(PHP 3, PHP 4 )

chdir -- change directory

Description

bool chdir ( string directory)

Changes PHP's current directory to directory. Returns FALSE if unable to change directory, TRUE otherwise.

chroot

(PHP 4 >= 4.0.5)

chroot -- change the root directory

Description

bool chroot ( string directory)

Changes the root directory of the current process to directory. Returns FALSE if unable to change the root directory, TRUE otherwise.

Note: It's not wise to use this function when running in a webserver environment, because it's not possible to reset the root directory to / again at the end of the request. This function will only function correct when running as CGI this way.

Note: This function is not implemented on Windows platforms.

dir

dir -- directory class

Description

 class dir {
  dir(string directory);  string path;  resource handle;  string read();  void rewind();  void close();}

A pseudo-object oriented mechanism for reading a directory. The given directory is opened. Two properties are available once the directory has been opened. The handle property can be used with other directory functions such as readdir(), rewinddir() and closedir(). The path property is set to path the directory that was opened. Three methods are available: read, rewind and close.

Please note the fashion in which dir()'s return value is checked in the example below. We are explicitly testing whether the return value is identical to (equal to and of the same type as--see Comparison Operators for more information) FALSE since otherwise, any directory entry whose name evaluates to FALSE will stop the loop.
Example 1. dir() example
$d = dir("/etc"); echo "Handle: ".$d->handle."<br>\n"; echo "Path: ".$d->path."<br>\n"; while (false !== ($entry = $d->read())) { echo $entry."<br>\n"; } $d->close();

Note: The order in which directory entries are returned by the read method is system-dependent.

Note: This defines the internal class Directory, meaning that you will not be able to define your own classes with that name. For a full list of predefined classes in PHP, please see Predefined Classes.

If path is not a valid directory or the directory can not be opened due to permission restrictions or filesystem errors, opendir() returns FALSE and generates a PHP error. You can suppress the error output of opendir() by prepending `@' to the front of the function name.

Example 1. opendir() example
<?php if ($dir = @opendir("/tmp")) { while (($file = readdir($dir)) !== false) { echo "$file\n"; } closedir($dir); } ?>

readdir

(PHP 3, PHP 4 )

readdir -- read entry from directory handle

Description

string readdir ( resource dir_handle)

Returns the filename of the next file from the directory. The filenames are returned in the order in which they are stored by the filesystem.

Please note the fashion in which readdir()'s return value is checked in the examples below. We are explicitly testing whether the return value is identical to (equal to and of the same type as--see Comparison Operators for more information) FALSE since otherwise, any directory entry whose name evaluates to FALSE will stop the loop (e.g. a directory named "0").

Example 1. List all files in a directory
// Note that !== did not exist until 4.0.0-RC2 <?php if ($handle = opendir('/path/to/files')) { echo "Directory handle: $handle\n"; echo "Files:\n"; /* This is the correct way to loop over the directory. */ while (false !== ($file = readdir($handle))) { echo "$file\n"; } /* This is the WRONG way to loop over the directory. */ while ($file = readdir($handle)) { echo "$file\n"; } closedir($handle); } ?>

Note that readdir() will return the . and .. entries. If you don't want these, simply strip them out:
Example 2. List all files in the current directory and strip out . and ..
<?php if ($handle = opendir('.')) { while (false !== ($file = readdir($handle))) { if ($file != "." && $file != "..") { echo "$file\n"; } } closedir($handle); } ?>

rewinddir

(PHP 3, PHP 4 )

rewinddir -- rewind directory handle

Description

void rewinddir ( resource dir_handle)

Resets the directory stream indicated by dir_handle to the beginning of the directory.

XXV. DOM XML functions

Introduction

Warning

The DOM XML extension has been overhauled in PHP 4.3.0 to better comply with the DOM standard. The extension still contains many old functions, but they should no longer be used. In particular, functions that are not object-oriented should be avoided.

The extension allows you to operate on an XML document with the DOM API. It also provides a function domxml_xmltree() to turn the complete XML document into a tree of PHP objects. Currently, this tree should be considered read-only — you can modify it, but this would not make any sense since DomDocument_dump_mem() cannot be applied to it. Therefore, if you want to read an XML file and write a modified version, use DomDocument_create_element(), DomDocument_create_text_node(), set_attribute(), etc. and finally the DomDocument_dump_mem() function.

Requirements

This extension makes use of the GNOME XML library. Download and install this library. You will need at least libxml-2.4.14.

Installation

This extension is only available if PHP was configured with --with-dom=[DIR].

Deprecated functions

There are quite a few functions that do not fit into the DOM standard and should no longer be used. These functions are listed in the following table. The function DomNode_append_child() has changed its behaviour. It now adds a child and not a sibling. If this breaks your application, use the non-DOM function DomNode_append_sibling().

Table 1. Deprecated functions and their replacements

Old function	New function
xmldoc	domxml_open_mem()
xmldocfile	domxml_open_file()
domxml_new_xmldoc	domxml_new_doc()
domxml_dump_mem	DomDocument_dump_mem()
domxml_dump_mem_file	DomDocument_dump_file()
DomDocument_dump_mem_file	DomDocument_dump_file()
DomDocument_add_root	DomDocument_create_element() followed by DomNode_append_child()
DomDocument_dtd	DomDocument_doctype()
DomDocument_root	DomDocument_document_element()
DomDocument_children	DomNode_child_nodes()
DomDocument_imported_node	No replacement.
DomNode_add_child	Create a new node with e.g. DomDocument_create_element() und add it with DomNode_append_child().
DomNode_children	DomNode_child_nodes()
DomNode_parent	DomNode_parent_node()
DomNode_new_child	Create a new node with e.g. DomDocument_create_element() and add it with DomNode_append_child().
DomNode_set_content	Create a new node with e.g. DomDocument_create_text_node() and add it with DomNode_append_child().
DomNode_get_content	Content is just a text node and can be accessed with DomNode_child_nodes().
DomNode_set_content	Content is just a text node and can be added with DomNode_append_child().

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

Table 2. XML constants

Constant	Value	Description
`XML_ELEMENT_NODE` (integer)	1	Node is an element
`XML_ATTRIBUTE_NODE` (integer)	2	Node is an attribute
`XML_TEXT_NODE` (integer)	3	Node is a piece of text
`XML_CDATA_SECTION_NODE` (integer)	4
`XML_ENTITY_REF_NODE` (integer)	5
`XML_ENTITY_NODE` (integer)	6	Node is an entity like
`XML_PI_NODE` (integer)	7	Node is a processing instruction
`XML_COMMENT_NODE` (integer)	8	Node is a comment
`XML_DOCUMENT_NODE` (integer)	9	Node is a document
`XML_DOCUMENT_TYPE_NODE` (integer)	10
`XML_DOCUMENT_FRAG_NODE` (integer)	11
`XML_NOTATION_NODE` (integer)	12
`XML_GLOBAL_NAMESPACE` (integer)	1
`XML_LOCAL_NAMESPACE` (integer)	2
`XML_HTML_DOCUMENT_NODE` (integer)
`XML_DTD_NODE` (integer)
`XML_ELEMENT_DECL_NODE` (integer)
`XML_ATTRIBUTE_DECL_NODE` (integer)
`XML_ENTITY_DECL_NODE` (integer)
`XML_NAMESPACE_DECL_NODE` (integer)
`XML_ATTRIBUTE_CDATA` (integer)
`XML_ATTRIBUTE_ID` (integer)
`XML_ATTRIBUTE_IDREF` (integer)
`XML_ATTRIBUTE_IDREFS` (integer)
`XML_ATTRIBUTE_ENTITY` (integer)
`XML_ATTRIBUTE_NMTOKEN` (integer)
`XML_ATTRIBUTE_NMTOKENS` (integer)
`XML_ATTRIBUTE_ENUMERATION` (integer)
`XML_ATTRIBUTE_NOTATION` (integer)
`XPATH_UNDEFINED` (integer)
`XPATH_NODESET` (integer)
`XPATH_BOOLEAN` (integer)
`XPATH_NUMBER` (integer)
`XPATH_STRING` (integer)
`XPATH_POINT` (integer)
`XPATH_RANGE` (integer)
`XPATH_LOCATIONSET` (integer)
`XPATH_USERS` (integer)
`XPATH_NUMBER` (integer)

Classes

The API of the module follows the DOM Level 2 standard as closely as possible. Consequently, the API is fully object-oriented. It is a good idea to have the DOM standard available when using this module. Though the API is object-oriented, there are many functions which can be called in a non-object-oriented way by passing the object to operate on as the first argument. These functions are mainly to retain compatibilty to older versions of the extension, and should not be used when creating new scripts.

This API differs from the official DOM API in two ways. First, all class attributes are implemented as functions with the same name. Secondly, the function names follow the PHP naming convention. This means that a DOM function lastChild() will be written as last_child().

This module defines a number of classes, which are listed — including their method — in the following tables. Classes with an equivalent in the DOM standard are named DOMxxx.

Table 3. List of classes

Class name	Parent classes
DomAttribute	DomNode
DomCData	DomNode
DomComment	DomCData : DomNode
DomDocument	DomNode
DomDocumentType	DomNode
DomElement	DomNode
DomEntity	DomNode
DomEntityReference	DomNode
DomProcessingInstruction	DomNode
DomText	DomCData : DomNode
Parser	Currently still called DomParser
XPathContext

Table 4. DomDocument class (DomDocument : DomNode)

Method name	Function name	Remark
doctype	DomDocument_doctype()
document_elemnent	DomDocument_document_element()
create_element	DomDocument_create_element()
create_text_node	DomDocument_create_text_node()
create_comment	DomDocument_create_comment()
create_cdata_section	DomDocument_create_cdata_section()
create_processing_instruction	DomDocument_create_processing_instruction()
create_attribute	DomDocument_create_attribute()
create_entity_reference	DomDocument_create_entity_reference()
get_elements_by_tagname	DomDocument_get_elements_by_tagname()
get_element_by_id	DomDocument_get_element_by_id()
dump_mem	DomDocument_dump_mem()	not DOM standard
dump_file	DomDocument_dump_file()	not DOM standard
html_dump_mem	DomDocument_html_dump_mem()	not DOM standard
xpath_init	xpath_init	not DOM standard
xpath_new_context	xpath_new_context	not DOM standard
xptr_new_context	xptr_new_context	not DOM standard

Table 5. DomElement class (DomElement : DomNode)

Method name	Function name	Remark
tagname	DomElement_tagname()
get_attribute	DomElement_get_attribute()
set_attribute	DomElement_set_attribute()
remove_attribute	DomElement_remove_attribute()
get_attribute_node	DomElement_get_attribute_node()
get_elements_by_tagname	DomElement_get_elements_by_tagname()
has_attribute	DomElement_has_attribute()

Table 6. DomNode class

Method name	Remark
DomNode_node_name()
DomNode_node_value()
DomNode_node_type()
DomNode_last_child()
DomNode_first_child()
DomNode_child_nodes()
DomNode_previous_sibling()
DomNode_next_sibling()
DomNode_parent_node()
DomNode_owner_document()
DomNode_insert_before()
DomNode_append_child()
DomNode_append_sibling()	Not in DOM standard. This function emulates the former behaviour of DomNode_append_child().
DomNode_remove_child()
DomNode_has_child_nodes()
DomNode_has_attributes()
DomNode_clone_node()
DomNode_attributes()
DomNode_unlink_node()	Not in DOM standard
DomNode_replace_node()	Not in DOM standard
DomNode_set_content()	Not in DOM standard, deprecated
DomNode_get_content()	Not in DOM standard, deprecated
DomNode_dump_node()	Not in DOM standard
DomNode_is_blank_node()	Not in DOM standard

Table 7. DomAttribute class (DomAttribute : DomNode)

Method name		Remark
name	DomAttribute_name()
value	DomAttribute_value()
specified	DomAttribute_specified()

Table 8. DomProcessingInstruction class (DomProcessingInstruction : DomNode)

Method name	Function name	Remark
target	DomProcessingInstruction_target()
data	DomProcessingInstruction_data()

Table 9. Parser class

Method name	Function name	Remark
add_chunk	Parser_add_chunk()
end	Parser_end()

Table 10. XPathContext class

Method name	Function name	Remark
eval	XPathContext_eval()
eval_expression	XPathContext_eval_expression()
register_ns	XPathContext_register_ns()

Table 11. DomDocumentType class (DomDocumentType : DomNode)

Method name	Function name	Remark
name	DomDocumentType_name()
entities	DomDocumentType_entities()
notations	DomDocumentType_notations()
public_id	DomDocumentType_public_id()
system_id	DomDocumentType_system_id()
internal_subset	DomDocumentType_internal_subset()

The classes DomDtd is derived from DomNode. DomComment is derived from DomCData.

Examples

Many examples in this reference require an XML string. Instead of repeating this string in every example, it will be put into a file which will be included by each example. This include file is shown in the following example section. Alternatively, you could create an XML document and read it with DomDocument_open_file().

Example 1. Include file example.inc with XML string
<?php $xmlstr = "<?xml version='1.0' standalone='yes'?> <!DOCTYPE chapter SYSTEM '/share/sgml/Norman_Walsh/db3xml10/db3xml10.dtd' [ <!ENTITY sp \"spanish\"> ]>  <chapter language='en'><title language='en'>Title</title> <para language='ge'> &sp;  <informaltable ID='findme' language='&sp;'> <tgroup cols='3'> <tbody> <row><entry>a1</entry><entry morerows='1'>b1</entry><entry>c1</entry></row> <row><entry>a2</entry><entry>c2</entry></row> <row><entry>a3</entry><entry>b3</entry><entry>c3</entry></row> </tbody> </tgroup> </informaltable> </para> </chapter>"; ?>

Table of Contents
DomAttribute->name -- Returns name of attribute
DomAttribute->specified -- Checks if attribute is specified
DomAttribute->value -- Returns value of attribute
DomDocument->add_root [deprecated] -- Adds a root node
DomDocument->create_attribute -- Create new attribute
DomDocument->create_cdata_section -- Create new cdata node
DomDocument->create_comment -- Create new comment node
DomDocument->create_element_ns -- Create new element node with an associated namespace
DomDocument->create_element -- Create new element node
DomDocument->create_entity_reference --
DomDocument->create_processing_instruction -- Creates new PI node
DomDocument->create_text_node -- Create new text node
DomDocument->doctype -- Returns the document type
DomDocument->document_element -- Returns root element node
DomDocument->dump_file -- Dumps the internal XML tree back into a file
DomDocument->dump_mem -- Dumps the internal XML tree back into a string
DomDocument->get_element_by_id -- Searches for an element with a certain id
DomDocument->get_elements_by_tagname --
DomDocument->html_dump_mem -- Dumps the internal XML tree back into a string as HTML
DomDocument->xinclude -- Substitutes XIncludes in a DomDocument Object.
DomDocumentType->entities -- Returns list of entities
DomDocumentType->internal_subset -- Returns internal subset
DomDocumentType->name -- Returns name of document type
DomDocumentType->notations -- Returns list of notations
DomDocumentType->public_id -- Returns public id of document type
DomDocumentType->system_id -- Returns system id of document type
DomElement->get_attribute_node -- Returns value of attribute
DomElement->get_attribute -- Returns value of attribute
DomElement->get_elements_by_tagname -- Gets elements by tagname
DomElement->has_attribute -- Checks to see if attribute exists
DomElement->remove_attribute -- Removes attribute
DomElement->set_attribute -- Adds new attribute
DomElement->tagname -- Returns name of element
DomNode->add_namespace -- Adds a namespace declaration to a node.
DomNode->append_child -- Adds new child at the end of the children
DomNode->append_sibling -- Adds new sibling to a node
DomNode->attributes -- Returns list of attributes
DomNode->child_nodes -- Returns children of node
DomNode->clone_node -- Clones a node
DomNode->dump_node -- Dumps a single node
DomNode->first_child -- Returns first child of node
DomNode->get_content -- Gets content of node
DomNode->has_attributess -- Checks if node has attributes
DomNode->has_child_nodes -- Checks if node has children
DomNode->insert_before -- Inserts new node as child
DomNode->is_blank_node -- Checks if node is blank
DomNode->last_child -- Returns last child of node
DomNode->next_sibling -- Returns the next sibling of node
DomNode->node_name -- Returns name of node
DomNode->node_type -- Returns type of node
DomNode->node_value -- Returns value of a node
DomNode->owner_document -- Returns the document this node belongs to
DomNode->parent_node -- Returns the parent of the node
DomNode->prefix -- Returns name space prefix of node
DomNode->previous_sibling -- Returns the previous sibling of node
DomNode->remove_child -- Removes child from list of children
DomNode->replace_child -- Replaces a child
DomNode->replace_node -- Replaces node
DomNode->set_content -- Sets content of node
DomNode->set_name -- Sets name of node
DomNode->set_namespace -- Sets namespace of a node.
DomNode->unlink_node -- Deletes node
DomProcessingInstruction->data -- Returns data of pi node
DomProcessingInstruction->target -- Returns target of pi node
DomXsltStylesheet->process -- Applies the XSLT-Transformation on a DomDocument Object.
domxml_new_doc -- Creates new empty XML document
domxml_open_file -- Creates a DOM object from XML file
domxml_open_mem -- Creates a DOM object of an XML document
domxml_version -- Get XML library version
domxml_xmltree -- Creates a tree of PHP objects from an XML document
domxml_xslt_stylesheet_doc -- Creates a DomXsltStylesheet Object from a DomDocument Object.
domxml_xslt_stylesheet_file -- Creates a DomXsltStylesheet Object from a xsl document in a file.
domxml_xslt_stylesheet -- Creates a DomXsltStylesheet Object from a xml document in a string.
xpath_eval_expression -- Evaluates the XPath Location Path in the given string
xpath_eval -- Evaluates the XPath Location Path in the given string
xpath_new_context -- Creates new xpath context
xptr_eval -- Evaluate the XPtr Location Path in the given string
xptr_new_context -- Create new XPath Context

DomDocument->create_processing_instruction

(no version information, might be only in CVS)

DomDocument->create_processing_instruction -- Creates new PI node

Description

string DomDocument->create_processing_instruction ( string content)

This function returns a new instance of class DomCData. The content of the pi is the value of the passed parameter. This node will not show up in the document unless it is inserted with e.g. DomNode_append_child().

The return value is false if an error occured.

See also DomNode_append_child(), DomDocument_create_element(), DomDocument_create_text(), DomDocument_create_cdata_section(), DomDocument_create_attribute(), DomDocument_create_entity_reference(), DomNode_insert_before().

DomDocument->create_text_node

(no version information, might be only in CVS)

DomDocument->create_text_node -- Create new text node

Description

object DomDocument->create_text_node ( string content)

string DomDocument->dump_file ( string filename [, bool compressionmode [, bool format]])

Creates an XML document from the dom representation. This function usually is called after building a new dom document from scratch as in the example below. The format specifies whether the output should be neatly formatted, or not. The first parameter specifies the name of the filename and the second parameter, whether it should be compressed or not.

Example 1. Creating a simple HTML document header
<?php $doc = domxml_new_doc("1.0"); $root = $doc->create_element("HTML"); $root = $doc->append_child($root); $head = $doc->create_element("HEAD"); $head = $root->append_child($head); $title = $doc->create_element("TITLE"); $title = $head->append_child($title); $text = $doc->create_text_node("This is the title"); $text = $title->append_child($text); $doc->dump_file("/tmp/test.xml", false, true); ?>

See also DomDocument_dump_mem() DomDocument_html_dump_mem().

DomDocument->dump_mem

(no version information, might be only in CVS)

DomDocument->dump_mem -- Dumps the internal XML tree back into a string

Description

string DomDocument->dump_mem ( [bool format [, string encoding]])

Warning

Note: The first parameter was added in PHP 4.3.0.

See also DomDocument_dump_file(), DomDocument_html_dump_mem().

DomDocument->get_element_by_id

(no version information, might be only in CVS)

DomDocument->get_element_by_id -- Searches for an element with a certain id

Description

object DomDocument->get_element_by_id ( string id)

This function is similar to DomDocument_get_elements_by_tagname() but searches for an element with a given id. According to the DOM standard this requires a DTD which defines the attribute ID to be of type ID, though the current implementation simply does an xpath search for "//*[@ID = '%s']". This does not comply to the DOM standard which requires to return null if it is not known which attribute is of type id. This behaviour is likely to be fixed, so do not rely on the current behaviour.

See also DomDocument_get_elements_by_tagname()

DomDocument->get_elements_by_tagname

(no version information, might be only in CVS)

See also DomDocument_create_element_ns(), DomNode_set_namespace()

DomNode->append_child

(no version information, might be only in CVS)

DomNode->append_child -- Adds new child at the end of the children

Description

object DomNode->append_child ( object newnode)

This functions appends a child to an existing list of children or creates a new list of children. The child can be created with e.g. DomDocument_create_element(), DomDocument_create_text() etc. or simply by using any other node.

(PHP < 4.3) Before a new child is appended it is first duplicated. Therefore the new child is a completely new copy which can be modified without changing the node which was passed to this function. If the node passed has children itself, they will be duplicated as well, which makes it quite easy to duplicate large parts of a xml document. The return value is the appended child. If you plan to do further modifications on the appended child you must use the returned node.

(PHP >= 4.3) The new child newnode is first unlinked from its existing context, if it already existed in a document. Therefore the node is moved and not copies anymore. This is the behaviour according to the W3C specifications. If you want to duplicate large parts of a xml document, use DomNode->clone_node() before appending.

The following example will add a new element node to a fresh document and sets the attribute "align" to "left".
Example 1. Adding a child
<?php $doc = domxml_new_doc("1.0"); $node = $doc->create_element("para"); $newnode = $doc->append_child($node); $newnode->set_attribute("align", "left"); ?>
The above example could also be written as the following:
Example 2. Adding a child
<?php $doc = domxml_new_doc("1.0"); $node = $doc->create_element("para"); $node->set_attribute("align", "left"); $newnode = $doc->append_child($node); ?>
A more comples example is the one below. It first searches for a certain element, duplicates it including its children and adds it as a sibling. Finally a new attribute is added to one of the children of the new sibling and the whole document is dumped.
Example 3. Adding a child
<?php include("example.inc"); if(!$dom = domxml_open_mem($xmlstr)) { echo "Error while parsing the document\n"; exit; } $elements = $dom->get_elements_by_tagname("informaltable"); print_r($elements); $element = $elements[0]; $parent = $element->parent_node(); $newnode = $parent->append_child($element); $children = $newnode->children(); $attr = $children[1]->set_attribute("align", "left"); echo "<PRE>"; $xmlfile = $dom->dump_mem(); echo htmlentities($xmlfile); echo "</PRE>"; ?>
The above example could also be done with DomNode_insert_before() instead of DomNode_append_child().

See also DomNode_insert_before(), DomNode_clone_node().

DomNode->append_sibling

(no version information, might be only in CVS)

DomNode->append_sibling -- Adds new sibling to a node

Description

object DomNode->append_sibling ( object newnode)

bool DomNode->first_child ( void)

Returns the first child of the node.

(PHP >= 4.3 only) If no first child is found, NULL is returned.

See also DomNode_last_child(), DomNode_next_sibling(), DomNode_previous_sibling().

DomNode->get_content

(no version information, might be only in CVS)

DomNode->get_content -- Gets content of node

Description

string DomNode->get_content ( void)

string DomNode->node_name ( void)

Returns name of the node. The name has different meanings for the different types of nodes as illustrated in the following table.

Table 1. Meaning of value

Type	Meaning
DomAttribute	value of attribute
DomAttribute
DomCDataSection	#cdata-section
DomComment	#comment
DomDocument	#document
DomDocumentType	document type name
DomElement	tag name
DomEntity	name of entity
DomEntityReference	name of entity reference
DomNotation	notation name
DomProcessingInstruction	target
DomText	#text

DomNode->node_type

(no version information, might be only in CVS)

DomNode->node_type -- Returns type of node

Description

int DomNode->node_type ( void)

Returns the type of the node. All possible types are listed in the table in the introduction.

DomNode->node_value

(no version information, might be only in CVS)

DomNode->node_value -- Returns value of a node

Description

string DomNode->node_value ( void)

Returns value of the node. The value has different meanings for the different types of nodes as illustrated in the following table.

Table 1. Meaning of value

Type	Meaning
DomAttribute	value of attribute
DomAttribute
DomCDataSection	content
DomComment	content of comment
DomDocument	null
DomDocumentType	null
DomElement	null
DomEntity	null
DomEntityReference	null
DomNotation	null
DomProcessingInstruction	entire content without target
DomText	content of text

DomNode->owner_document

(no version information, might be only in CVS)

DomNode->owner_document -- Returns the document this node belongs to

Description

object DomNode->owner_document ( void)

This function returns the document the current node belongs to.

The following example will create two identical lists of children.
Example 1. Finding the document of a node
<?php $doc = domxml_new_doc("1.0"); $node = $doc->create_element("para"); $node = $doc->append_child($node); $children = $doc->children(); print_r($children); $doc2 = $node->owner_document(); $children = $doc2->children(); print_r($children); ?>

DomNode->parent_node

(no version information, might be only in CVS)

DomNode->parent_node -- Returns the parent of the node

Description

object DomNode->parent_node ( void)

This function returns the parent node.

This function returns the version of the XML library version currently used.

domxml_xmltree

(PHP 4 >= 4.2.1)

domxml_xmltree -- Creates a tree of PHP objects from an XML document

int xptr_eval ( [object xpath_context, string eval_str])

Warning

This function is currently not documented; only the argument list is available.

xptr_new_context

(PHP 4 >= 4.0.4)

xptr_new_context -- Create new XPath Context

Description

string xptr_new_context ( [object doc_handle])

Warning

This function is currently not documented; only the argument list is available.

XXVI. .NET functions

Introduction

Warning

Table of Contents
dotnet_load -- Loads a DOTNET module

dotnet_load

(no version information, might be only in CVS)

dotnet_load -- Loads a DOTNET module

Description

int dotnet_load ( string assembly_name [, string datatype_name [, int codepage]])

Warning

This function is currently not documented; only the argument list is available.

XXVII. Error Handling and Logging Functions

Introduction

These are functions dealing with error handling and logging. They allow you to define your own error handling rules, as well as modify the way the errors can be logged. This allows you to change and enhance error reporting to suit your needs.

With the logging functions, you can send messages directly to other machines, to an email (or email to pager gateway!), to system logs, etc., so you can selectively log and monitor the most important parts of your applications and websites.

The error reporting functions allow you to customize what level and kind of error feedback is given, ranging from simple notices to customized functions returned during errors.

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Errors and Logging Configuration Options

Name	Default	Changeable
error_reporting	E_ALL & ~E_NOTICE	PHP_INI_ALL
display_errors	"1"	PHP_INI_ALL
display_startup_errors	"0"	PHP_INI_ALL
log_errors	"0"	PHP_INI_ALL
log_errors_max_len	"1024"	PHP_INI_ALL
ignore_repeated_errors	"0"	PHP_INI_ALL
ignore_repeated_source	"0"	PHP_INI_ALL
report_memleaks	"1"	PHP_INI_SYSTEM
track_errors	"0"	PHP_INI_ALL
html_errors	"1"	PHP_INI_ALL
docref_root	"http://www.php.net/"	PHP_INI_ALL
docref_ext	".html"	PHP_INI_ALL
error_prepend_string	NULL	PHP_INI_ALL
error_append_string	NULL	PHP_INI_ALL
error_log	NULL	PHP_INI_ALL
warn_plus_overloading	NULL	PHP_INI??

For further details and definition of the PHP_INI_* constants see ini_set().

Here is a short explanation of the configuration directives.

error_reporting integer

Set the error reporting level. The parameter is either an integer representing a bit field, or named constants. The error_reporting levels and constants are described in Predefined Constants, and in php.ini. To set at runtime, use the error_reporting() function. See also the display_errors directive.

In PHP 4 the default value does not show E_NOTICE level errors. You may want to show them during development.

Note: Enabling E_NOTICE during development has some benefits. For debugging purposes: NOTICE messages will warn you about possibls bugs in your code. For example, use of unassigned values are warned. It is extremely useful to find typos and to save time for debugging. NOTICE messages will warn you about bad style. For example, $arr[item] is better to be written as $arr['item'] since PHP tries to treat "item" as constant. If it is not a constant, PHP assumes it is a string index for the array.

In PHP 3, the default setting is (E_ERROR | E_WARNING | E_PARSE), meaning the same thing. Note, however, that since constants are not supported in PHP 3's php3.ini, the error_reporting setting there must be numeric; hence, it is 7.

display_errors boolean

This determines whether errors should be printed to the screen as part of the HTML output or not.

display_startup_errors boolean

Even when display_errors is on, errors that occur during PHP's startup sequence are not displayed. It's strongly recommended to keep display_startup_errors off, except for debugging.

log_errors boolean

Tells whether script error messages should be logged to the server's error log or error_log. This option is thus server-specific.

Note: You're strongly advised to use error logging in place of error displaying on production web sites.

log_errors_max_len integer

Set the maximum length of log_errors in kbytes. In error_log information about the source is added. The default is 1024 and 0 allows to not apply any maximum length at all.

ignore_repeated_errors boolean

Do not log repeated messages. Repeated errors must occur in the same file on the same line until ignore_repeated_source is set true.

ignore_repeated_source boolean

Ignore source of message when ignoring repeated messages. When this setting is On you will not log errors with repeated messages from different files or sourcelines.

report_memleaks boolean

If this parameter is set to Off, then memory leaks will not be shown (on stdout or in the log). This has only effect in a debug compile, and if error_reporting includes E_WARNING in the allowed list

track_errors boolean

If enabled, the last error message will always be present in the variable $php_errormsg.

html_errors boolean

Turn off HTML tags in error messages. The new format for html errors produces clickable messages that direct the user to a page describing the error or function in causing the error. These references are affected by docref_root and docref_ext.

docref_root string

The new error format contains a reference to a page describing the error or function in causing the error. In case of manual pages you can download the manual in your language and set this ini directive to the url of your local copy. If your local copy of the manual can be reached by '/manual/' you can simply use docref_root=/manual/. Additional you have to set docref_ext to match the fileextensions of your copy docref_ext=.html. It is possible to use external references. For example you can use docref_root=http://manual/en/ or docref_root="http://landonize.it/?how=url&theme=classic&filter=Landon&url=http%3A%2F%2Fwww.php.net%2F"

Most of the time you want the docref_root value to end with a slash '/'. But see the second example above which does not have nor need it.

docref_ext string

See docref_root.

Note: The value of docref_ext must begin with a dot '.'.

error_prepend_string string

String to output before an error message.

error_append_string string

String to output after an error message.

error_log string

Name of the file where script errors should be logged. If the special value syslog is used, the errors are sent to the system logger instead. On UNIX, this means syslog(3) and on Windows NT it means the event log. The system logger is not supported on Windows 95. See also: syslog().

warn_plus_overloading boolean

If enabled, this option makes PHP output a warning when the plus (+) operator is used on strings. This is to make it easier to find scripts that need to be rewritten to using the string concatenator instead (.).

Predefined Constants

The constants below are always available as part of the PHP core.

Note: You may use these constant names in php.ini but not outside of PHP, like in httpd.conf, where you'd use the bitmask values instead.

Table 2. Errors and Logging

Value	Constant	Description	Note
1	`E_ERROR` (integer)	Fatal run-time errors. These indicate errors that can not be recovered from, such as a memory allocation problem. Execution of the script is halted.
2	`E_WARNING` (integer)	Run-time warnings (non-fatal errors). Execution of the script is not halted.
4	`E_PARSE` (integer)	Compile-time parse errors. Parse errors should only be generated by the parser.
8	`E_NOTICE` (integer)	Run-time notices. Indicate that the script encountered something that could indicate an error, but could also happen in the normal course of running a script.
16	`E_CORE_ERROR` (integer)	Fatal errors that occur during PHP's initial startup. This is like an `E_ERROR`, except it is generated by the core of PHP.	PHP 4 only
32	`E_CORE_WARNING` (integer)	Warnings (non-fatal errors) that occur during PHP's initial startup. This is like an `E_WARNING`, except it is generated by the core of PHP.	PHP 4 only
64	`E_COMPILE_ERROR` (integer)	Fatal compile-time errors. This is like an `E_ERROR`, except it is generated by the Zend Scripting Engine.	PHP 4 only
128	`E_COMPILE_WARNING` (integer)	Compile-time warnings (non-fatal errors). This is like an `E_WARNING`, except it is generated by the Zend Scripting Engine.	PHP 4 only
256	`E_USER_ERROR` (integer)	User-generated error message. This is like an `E_ERROR`, except it is generated in PHP code by using the PHP function trigger_error().	PHP 4 only
512	`E_USER_WARNING` (integer)	User-generated warning message. This is like an `E_WARNING`, except it is generated in PHP code by using the PHP function trigger_error().	PHP 4 only
1024	`E_USER_NOTICE` (integer)	User-generated notice message. This is like an `E_NOTICE`, except it is generated in PHP code by using the PHP function trigger_error().	PHP 4 only
2047	`E_ALL` (integer)	All errors and warnings, as supported.

The above values (either numerical or symbolic) are used to build up a bitmask that specifies which errors to report. You can use the bitwise operators to combine these values or mask out certain types of errors. Note that only '|', '~', '!', and '&' will be understood within php.ini, however, and that no bitwise operators will be understood within php3.ini.

Examples

Below we can see an example of using the error handling capabilities in PHP. We define a error handling function which logs the information into a file (using an XML format), and e-mails the developer in case a critical error in the logic happens.
Example 1. Using error handling in a script
<?php // we will do our own error handling error_reporting(0); // user defined error handling function function userErrorHandler ($errno, $errmsg, $filename, $linenum, $vars) { // timestamp for the error entry $dt = date("Y-m-d H:i:s (T)"); // define an assoc array of error string // in reality the only entries we should // consider are 2,8,256,512 and 1024 $errortype = array ( 1 => "Error", 2 => "Warning", 4 => "Parsing Error", 8 => "Notice", 16 => "Core Error", 32 => "Core Warning", 64 => "Compile Error", 128 => "Compile Warning", 256 => "User Error", 512 => "User Warning", 1024=> "User Notice" ); // set of errors for which a var trace will be saved $user_errors = array(E_USER_ERROR, E_USER_WARNING, E_USER_NOTICE); $err = "<errorentry>\n"; $err .= "\t<datetime>".$dt."</datetime>\n"; $err .= "\t<errornum>".$errno."</errornum>\n"; $err .= "\t<errortype>".$errortype[$errno]."</errortype>\n"; $err .= "\t<errormsg>".$errmsg."</errormsg>\n"; $err .= "\t<scriptname>".$filename."</scriptname>\n"; $err .= "\t<scriptlinenum>".$linenum."</scriptlinenum>\n"; if (in_array($errno, $user_errors)) $err .= "\t<vartrace>".wddx_serialize_value($vars,"Variables")."</vartrace>\n"; $err .= "</errorentry>\n\n"; // for testing // echo $err; // save to the error log, and e-mail me if there is a critical user error error_log($err, 3, "/usr/local/php4/error.log"); if ($errno == E_USER_ERROR) mail("phpdev@example.com","Critical User Error",$err); } function distance ($vect1, $vect2) { if (!is_array($vect1) || !is_array($vect2)) { trigger_error("Incorrect parameters, arrays expected", E_USER_ERROR); return NULL; } if (count($vect1) != count($vect2)) { trigger_error("Vectors need to be of the same size", E_USER_ERROR); return NULL; } for ($i=0; $i<count($vect1); $i++) { $c1 = $vect1[$i]; $c2 = $vect2[$i]; $d = 0.0; if (!is_numeric($c1)) { trigger_error("Coordinate $i in vector 1 is not a number, using zero", E_USER_WARNING); $c1 = 0.0; } if (!is_numeric($c2)) { trigger_error("Coordinate $i in vector 2 is not a number, using zero", E_USER_WARNING); $c2 = 0.0; } $d += $c2*$c2 - $c1*$c1; } return sqrt($d); } $old_error_handler = set_error_handler("userErrorHandler"); // undefined constant, generates a warning $t = I_AM_NOT_DEFINED; // define some "vectors" $a = array(2,3,"foo"); $b = array(5.5, 4.3, -1.6); $c = array (1,-3); // generate a user error $t1 = distance($c,$b)."\n"; // generate another user error $t2 = distance($b,"i am not an array")."\n"; // generate a warning $t3 = distance($a,$b)."\n"; ?>

error_log

(PHP 3, PHP 4 )

error_log -- send an error message somewhere

Description

int error_log ( string message [, int message_type [, string destination [, string extra_headers]]])

Sends an error message to the web server's error log, a TCP port or to a file. The first parameter, message, is the error message that should be logged. The second parameter, message_type says where the message should go:

Table 1. error_log() log types

0	`message` is sent to PHP's system logger, using the Operating System's system logging mechanism or a file, depending on what the error_log configuration directive is set to.
1	`message` is sent by email to the address in the `destination` parameter. This is the only message type where the fourth parameter, `extra_headers` is used. This message type uses the same internal function as mail() does.
2	`message` is sent through the PHP debugging connection. This option is only available if remote debugging has been enabled. In this case, the `destination` parameter specifies the host name or IP address and optionally, port number, of the socket receiving the debug information.
3	`message` is appended to the file `destination`.

Warning

Remote debugging via TCP/IP is a PHP 3 feature that is not available in PHP 4.

Example 1. error_log() examples
// Send notification through the server log if we can not // connect to the database. if (!Ora_Logon ($username, $password)) { error_log ("Oracle database not available!", 0); } // Notify administrator by email if we run out of FOO if (!($foo = allocate_new_foo()) { error_log ("Big trouble, we're all out of FOOs!", 1, "operator@mydomain.com"); } // other ways of calling error_log(): error_log ("You messed up!", 2, "127.0.0.1:7000"); error_log ("You messed up!", 2, "loghost"); error_log ("You messed up!", 3, "/var/tmp/my-errors.log");

error_reporting

(PHP 3, PHP 4 )

error_reporting -- set which PHP errors are reported

Description

int error_reporting ( [int level])

The error_reporting() function sets the error_reporting directive at runtime. PHP has many levels of errors, using this function sets that level for the duration (runtime) of your script.

error_reporting() sets PHP's error reporting level, and returns the old level. The level parameter takes on either a bitmask, or named constants. Using named constants is strongly encouraged to ensure compatibility for future versions. As error levels are added, the range of integers increases, so older integer-based error levels will not always behave as expected.

Some example uses:

Example 1. error_reporting() examples
<?php // Turn off all error reporting error_reporting(0); // Report simple running errors error_reporting (E_ERROR | E_WARNING | E_PARSE); // Reporting E_NOTICE can be good too (to report uninitialized // variables or catch variable name misspellings ...) error_reporting (E_ERROR | E_WARNING | E_PARSE | E_NOTICE); // Report all errors except E_NOTICE // This is the default value set in php.ini error_reporting (E_ALL ^ E_NOTICE); // Report all PHP errors (bitwise 63 may be used in PHP 3) error_reporting (E_ALL); // Same as error_reporting(E_ALL); ini_set ('error_reporting', E_ALL); ?>

The available error level constants are listed below. The actual meanings of these error levels are described in the predefined constants.

Table 1. error_reporting() level constants and bit values

value	constant
1	E_ERROR
2	E_WARNING
4	E_PARSE
8	E_NOTICE
16	E_CORE_ERROR
32	E_CORE_WARNING
64	E_COMPILE_ERROR
128	E_COMPILE_WARNING
256	E_USER_ERROR
512	E_USER_WARNING
1024	E_USER_NOTICE
2047	E_ALL

See also the display_errors directive and ini_set().

restore_error_handler

(PHP 4 >= 4.0.1)

restore_error_handler -- Restores the previous error handler function

Description

void restore_error_handler ( void)

Used after changing the error handler function using set_error_handler(), to revert to the previous error handler (which could be the built-in or a user defined function)

set_error_handler

(PHP 4 >= 4.0.1)

set_error_handler -- Sets a user-defined error handler function.

Description

string set_error_handler ( string error_handler)

Sets a user function (error_handler) to handle errors in a script. Returns the previously defined error handler (if any), or FALSE on error. This function can be used for defining your own way of handling errors during runtime, for example in applications in which you need to do cleanup of data/files when a critical error happens, or when you need to trigger an error under certain conditions (using trigger_error())

The user function needs to accept 2 parameters: the error code, and a string describing the error. From PHP 4.0.2, an additional 3 optional parameters are supplied: the filename in which the error occurred, the line number in which the error occurred, and the context in which the error occurred (an array that points to the active symbol table at the point the error occurred).

Note: Instead of a function name, an array containing an object reference and a method name can also be supplied. (Since PHP 4.3.0)

Note: The following error types cannot be handled with a user defined function: E_ERROR, E_PARSE, E_CORE_ERROR, E_CORE_WARNING, E_COMPILE_ERROR and E_COMPILE_WARNING.

The example below shows the handling of internal exceptions by triggering errors and handling them with a user defined function:
Example 1. Error handling with set_error_handler() and trigger_error()
<?php // redefine the user error constants - PHP 4 only define ("FATAL",E_USER_ERROR); define ("ERROR",E_USER_WARNING); define ("WARNING",E_USER_NOTICE); // set the error reporting level for this script error_reporting (FATAL | ERROR | WARNING); // error handler function function myErrorHandler ($errno, $errstr, $errfile, $errline) { switch ($errno) { case FATAL: echo "<b>FATAL</b> [$errno] $errstr<br>\n"; echo " Fatal error in line ".$errline." of file ".$errfile; echo ", PHP ".PHP_VERSION." (".PHP_OS.")<br>\n"; echo "Aborting...<br>\n"; exit(1); break; case ERROR: echo "<b>ERROR</b> [$errno] $errstr<br>\n"; break; case WARNING: echo "<b>WARNING</b> [$errno] $errstr<br>\n"; break; default: echo "Unkown error type: [$errno] $errstr<br>\n"; break; } } // function to test the error handling function scale_by_log ($vect, $scale) { if ( !is_numeric($scale) || $scale <= 0 ) trigger_error("log(x) for x <= 0 is undefined, you used: scale = $scale", FATAL); if (!is_array($vect)) { trigger_error("Incorrect input vector, array of values expected", ERROR); return null; } for ($i=0; $i<count($vect); $i++) { if (!is_numeric($vect[$i])) trigger_error("Value at position $i is not a number, using 0 (zero)", WARNING); $temp[$i] = log($scale) * $vect[$i]; } return $temp; } // set to the user defined error handler $old_error_handler = set_error_handler("myErrorHandler"); // trigger some errors, first define a mixed array with a non-numeric item echo "vector a\n"; $a = array(2,3,"foo",5.5,43.3,21.11); print_r($a); // now generate second array, generating a warning echo "----\nvector b - a warning (b = log(PI) * a)\n"; $b = scale_by_log($a, M_PI); print_r($b); // this is trouble, we pass a string instead of an array echo "----\nvector c - an error\n"; $c = scale_by_log("not array",2.3); var_dump($c); // this is a critical error, log of zero or negative number is undefined echo "----\nvector d - fatal error\n"; $d = scale_by_log($a, -2.5); ?>
And when you run this sample script, the output will be

vector a
Array
(
    [0] => 2
    [1] => 3
    [2] => foo
    [3] => 5.5
    [4] => 43.3
    [5] => 21.11
)
----
vector b - a warning (b = log(PI) * a)
<b>WARNING</b> [1024] Value at position 2 is not a number, using 0 (zero)<br>
Array
(
    [0] => 2.2894597716988
    [1] => 3.4341896575482
    [2] => 0
    [3] => 6.2960143721717
    [4] => 49.566804057279
    [5] => 24.165247890281
)
----
vector c - an error
<b>ERROR</b> [512] Incorrect input vector, array of values expected<br>
NULL
----
vector d - fatal error
<b>FATAL</b> [256] log(x) for x <= 0 is undefined, you used: scale = -2.5<br>
  Fatal error in line 36 of file trigger_error.php, PHP 4.0.2 (Linux)<br>
Aborting...<br>

It is important to remember that the standard PHP error handler is completely bypassed. error_reporting() settings will have no effect and your error handler will be called regardless - however you are still able to read the current value of error_reporting and act appropriately. Of particular note is that this value will be 0 if the statement that caused the error was prepended by the @ error-control operator.

Also note that it is your responsibility to die() if necessary. If the error-handler function returns, script execution will continue with the next statement after the one that caused an error.

Note: If errors occur before the script is executed (e.g. on file uploads) the custom error handler cannot be called since it is not registered at that time.

trigger_error

(PHP 4 >= 4.0.1)

trigger_error -- Generates a user-level error/warning/notice message

Description

void trigger_error ( string error_msg [, int error_type])

Used to trigger a user error condition, it can be used by in conjunction with the built-in error handler, or with a user defined function that has been set as the new error handler (set_error_handler()). It only works with the E_USER family of constants, and will default to E_USER_NOTICE.

This function is useful when you need to generate a particular response to an exception at runtime. For example:

if (assert ($divisor == 0))
   trigger_error ("Cannot divide by zero", E_USER_ERROR);

Note: See set_error_handler() for a more extensive example.

user_error

(PHP 4 )

user_error -- Generates a user-level error/warning/notice message

Description

void user_error ( string error_msg [, int error_type])

This is an alias for the function trigger_error().

XXVIII. FrontBase Functions

Introduction

These functions allow you to access FrontBase database servers. More information about FrontBase can be found at http://www.frontbase.com/.

Documentation for FrontBase can be found at http://www.frontbase.com/cgi-bin/WebObjects/FrontBase.woa/wa/productsPage?currentPage=Documentation.

Frontbase support has been added to PHP 4.0.6.

Requirements

You must install the FrontBase database server or at least the fbsql client libraries to use this functions. You can get FrontBase from http://www.frontbase.com/.

Installation

In order to have these functions available, you must compile PHP with fbsql support by using the --with-fbsql option. If you use this option without specifying the path to fbsql, PHP will search for the fbsql client libraries in the default installation location for the platform. Users who installed FrontBase in a non standard directory should always specify the path to fbsql: --with-fbsql=/path/to/fbsql. This will force PHP to use the client libraries installed by FrontBase, avoiding any conflicts.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. FrontBase configuration options

Name	Default	Changeable
fbsql.allow_persistent	"1"	PHP_INI_SYSTEM
fbsql.generate_warnings	"0"	PHP_INI_SYSTEM
fbsql.autocommit	"1"	PHP_INI_SYSTEM
fbsql.max_persistent	"-1"	PHP_INI_SYSTEM
fbsql.max_links	"128"	PHP_INI_SYSTEM
fbsql.max_connections	"128"	PHP_INI_SYSTEM
fbsql.max_results	"128"	PHP_INI_SYSTEM
fbsql.batchSize	"1000"	PHP_INI_SYSTEM
fbsql.default_host	NULL	PHP_INI_SYSTEM
fbsql.default_user	"_SYSTEM"	PHP_INI_SYSTEM
fbsql.default_password	""	PHP_INI_SYSTEM
fbsql.default_database	""	PHP_INI_SYSTEM
fbsql.default_database_password	""	PHP_INI_SYSTEM

For further details and definition of the PHP_INI_* constants see ini_set().

Resource Types

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

FBSQL_ASSOC (integer)
FBSQL_NUM (integer)
FBSQL_BOTH (integer)
FBSQL_LOCK_DEFERRED (integer)
FBSQL_LOCK_OPTIMISTIC (integer)
FBSQL_LOCK_PESSIMISTIC (integer)
FBSQL_ISO_READ_UNCOMMITTED (integer)
FBSQL_ISO_READ_COMMITTED (integer)
FBSQL_ISO_REPEATABLE_READ (integer)
FBSQL_ISO_SERIALIZABLE (integer)
FBSQL_ISO_VERSIONED (integer)
FBSQL_UNKNOWN (integer)
FBSQL_STOPPED (integer)
FBSQL_STARTING (integer)
FBSQL_RUNNING (integer)
FBSQL_STOPPING (integer)
FBSQL_NOEXEC (integer)
FBSQL_LOB_DIRECT (integer)
FBSQL_LOB_HANDLE (integer)

Table of Contents
fbsql_affected_rows -- Get number of affected rows in previous FrontBase operation
fbsql_autocommit -- Enable or disable autocommit
fbsql_change_user -- Change logged in user of the active connection
fbsql_close -- Close FrontBase connection
fbsql_commit -- Commits a transaction to the database
fbsql_connect -- Open a connection to a FrontBase Server
fbsql_create_blob -- Create a BLOB
fbsql_create_clob -- Create a CLOB
fbsql_create_db -- Create a FrontBase database
fbsql_data_seek -- Move internal result pointer
fbsql_database_password -- Sets or retrieves the password for a FrontBase database
fbsql_database -- Get or set the database name used with a connection
fbsql_db_query -- Send a FrontBase query
fbsql_db_status -- Get the status for a given database
fbsql_drop_db -- Drop (delete) a FrontBase database
fbsql_errno -- Returns the numerical value of the error message from previous FrontBase operation
fbsql_error -- Returns the text of the error message from previous FrontBase operation
fbsql_fetch_array -- Fetch a result row as an associative array, a numeric array, or both
fbsql_fetch_assoc -- Fetch a result row as an associative array
fbsql_fetch_field -- Get column information from a result and return as an object
fbsql_fetch_lengths -- Get the length of each output in a result
fbsql_fetch_object -- Fetch a result row as an object
fbsql_fetch_row -- Get a result row as an enumerated array
fbsql_field_flags -- Get the flags associated with the specified field in a result
fbsql_field_len -- Returns the length of the specified field
fbsql_field_name -- Get the name of the specified field in a result
fbsql_field_seek -- Set result pointer to a specified field offset
fbsql_field_table -- Get name of the table the specified field is in
fbsql_field_type -- Get the type of the specified field in a result
fbsql_free_result -- Free result memory
fbsql_get_autostart_info -- No description given yet
fbsql_hostname -- Get or set the host name used with a connection
fbsql_insert_id -- Get the id generated from the previous INSERT operation
fbsql_list_dbs -- List databases available on a FrontBase server
fbsql_list_fields -- List FrontBase result fields
fbsql_list_tables -- List tables in a FrontBase database
fbsql_next_result -- Move the internal result pointer to the next result
fbsql_num_fields -- Get number of fields in result
fbsql_num_rows -- Get number of rows in result
fbsql_password -- Get or set the user password used with a connection
fbsql_pconnect -- Open a persistent connection to a FrontBase Server
fbsql_query -- Send a FrontBase query
fbsql_read_blob -- Read a BLOB from the database
fbsql_read_clob -- Read a CLOB from the database
fbsql_result -- Get result data
fbsql_rollback -- Rollback a transaction to the database
fbsql_select_db -- Select a FrontBase database
fbsql_set_lob_mode -- Set the LOB retrieve mode for a FrontBase result set
fbsql_set_transaction -- Set the transaction locking and isolation
fbsql_start_db -- Start a database on local or remote server
fbsql_stop_db -- Stop a database on local or remote server
fbsql_tablename -- Get table name of field
fbsql_username -- Get or set the host user used with a connection
fbsql_warnings -- Enable or disable FrontBase warnings

fbsql_affected_rows

(PHP 4 >= 4.0.6)

fbsql_affected_rows -- Get number of affected rows in previous FrontBase operation

Description

int fbsql_affected_rows ( [resource link_identifier])

fbsql_affected_rows() returns the number of rows affected by the last INSERT, UPDATE or DELETE query associated with link_identifier. If the link identifier isn't specified, the last link opened by fbsql_connect() is assumed.

Note: If you are using transactions, you need to call fbsql_affected_rows() after your INSERT, UPDATE, or DELETE query, not after the commit.

If the last query was a DELETE query with no WHERE clause, all of the records will have been deleted from the table but this function will return zero.

Note: When using UPDATE, FrontBase will not update columns where the new value is the same as the old value. This creates the possibility that fbsql_affected_rows() may not actually equal the number of rows matched, only the number of rows that were literally affected by the query.

Returns: TRUE on success, FALSE on error.

fbsql_close() closes the connection to the FrontBase server that's associated with the specified link identifier. If link_identifier isn't specified, the last opened link is used.

Using fbsql_close() isn't usually necessary, as non-persistent open links are automatically closed at the end of the script's execution.

Example 1. fbsql_close() example

<?php
    $link = fbsql_connect ("localhost", "_SYSTEM", "secret")
        or die ("Could not connect");
    print ("Connected successfully");
    fbsql_close ($link);
?>

fbsql_commit

(PHP 4 >= 4.0.6)

fbsql_commit -- Commits a transaction to the database

Description

bool fbsql_commit ( [resource link_identifier])

Returns TRUE on success or FALSE on failure.

fbsql_commit() ends the current transaction by writing all inserts, updates and deletes to the disk and unlocking all row and table locks held by the transaction. This command is only needed if autocommit is set to false.

fbsql_connect

(PHP 4 >= 4.0.6)

fbsql_connect -- Open a connection to a FrontBase Server

Description

resource fbsql_connect ( [string hostname [, string username [, string password]]])

Returns a positive FrontBase link identifier on success, or an error message on failure.

fbsql_connect() establishes a connection to a FrontBase server. The following defaults are assumed for missing optional parameters: hostname = 'NULL', username = '_SYSTEM' and password = empty password.

If a second call is made to fbsql_connect() with the same arguments, no new link will be established, but instead, the link identifier of the already opened link will be returned.

The link to the server will be closed as soon as the execution of the script ends, unless it's closed earlier by explicitly calling fbsql_close().

Example 1. fbsql_connect() example

<?php

    $link = fbsql_connect ("localhost", "_SYSTEM", "secret")
        or die ("Could not connect");
    print ("Connected successfully");
    fbsql_close ($link);

?>

fbsql_create_blob

(PHP 4 >= 4.2.0)

fbsql_create_blob -- Create a BLOB

Description

string fbsql_create_blob ( string blob_data [, resource link_identifier])

Returns: A resource handle to the newly created blob.

fbsql_create_blob() creates a blob from blob_data. The returned resource handle can be used with insert and update commands to store the blob in the database.

Example 1. fbsql_create_blob() example

<?php
    $link = fbsql_pconnect ("localhost", "_SYSTEM", "secret")
        or die ("Could not connect");
    $filename = "blobfile.bin";
    $fp = fopen($filename, "rb");
    $blobdata = fread($fp, filesize($filename));
    fclose($fp);
    
    $blobHandle = fbsql_create_blob($blobdata, $link);
    
    $sql = "INSERT INTO BLOB_TABLE (BLOB_COLUMN) VALUES ($blobHandle);";
    $rs = fbsql_query($sql, $link);
?>

fbsql_create_clob

(PHP 4 >= 4.2.0)

fbsql_create_clob -- Create a CLOB

Description

string fbsql_create_clob ( string clob_data [, resource link_identifier])

Returns: A resource handle to the newly created CLOB.

fbsql_create_clob() creates a clob from clob_data. The returned resource handle can be used with insert and update commands to store the clob in the database.

Example 1. fbsql_create_clob() example

<?php
    $link = fbsql_pconnect ("localhost", "_SYSTEM", "secret")
        or die ("Could not connect");
    $filename = "clob_file.txt";
    $fp = fopen($filename, "rb");
    $clobdata = fread($fp, filesize($filename));
    fclose($fp);
    
    $clobHandle = fbsql_create_clob($clobdata, $link);
    
    $sql = "INSERT INTO CLOB_TABLE (CLOB_COLUMN) VALUES ($clobHandle);";
    $rs = fbsql_query($sql, $link);
?>

fbsql_create_db

(PHP 4 >= 4.0.6)

fbsql_create_db -- Create a FrontBase database

Description

bool fbsql_create_db ( string database name [, resource link_identifier])

fbsql_create_db() attempts to create a new database on the server associated with the specified link identifier.

Example 1. fbsql_create_db() example

<?php
    $link = fbsql_pconnect ("localhost", "_SYSTEM", "secret")
        or die ("Could not connect");
    if (fbsql_create_db ("my_db")) {
        print("Database created successfully\n");
    } else {
        printf("Error creating database: %s\n", fbsql_error ());
    }
?>

fbsql_data_seek

(PHP 4 >= 4.0.6)

fbsql_data_seek -- Move internal result pointer

Description

bool fbsql_data_seek ( resource result_identifier, int row_number)

Returns TRUE on success or FALSE on failure.

fbsql_data_seek() moves the internal row pointer of the FrontBase result associated with the specified result identifier to point to the specified row number. The next call to fbsql_fetch_row() would return that row.

Row_number starts at 0.

Example 1. fbsql_data_seek() example

<?php
    $link = fbsql_pconnect ("localhost", "_SYSTEM", "secret")
        or die ("Could not connect");

    fbsql_select_db ("samp_db")
        or die ("Could not select database");

    $query = "SELECT last_name, first_name FROM friends;";
    $result = fbsql_query ($query)
        or die ("Query failed");

    # fetch rows in reverse order

    for ($i = fbsql_num_rows ($result) - 1; $i >=0; $i--) {
        if (!fbsql_data_seek ($result, $i)) {
            printf ("Cannot seek to row %d\n", $i);
            continue;
        }

        if(!($row = fbsql_fetch_object ($result)))
            continue;

        printf("%s %s<BR>\n", $row->last_name, $row->first_name);
    }

    fbsql_free_result ($result);
?>

fbsql_database_password

(PHP 4 >= 4.0.6)

fbsql_database_password -- Sets or retrieves the password for a FrontBase database

Description

string fbsql_database_password ( resource link_identifier [, string database_password])

Returns: The database password associated with the link identifier.

fbsql_database_password() sets and retrieves the database password used by the connection. if a database is protected by a database password, the user must call this function before calling fbsql_select_db(). if the second optional parameter is given the function sets the database password for the specified link identifier. If no link identifier is specified, the last opened link is assumed. If no link is open, the function will try to establish a link as if fbsql_connect() was called, and use it.

This function does not change the database password in the database nor can it be used to retrive the database password for a database.

Example 1. fbsql_create_clob() example

<?php
    $link = fbsql_pconnect ("localhost", "_SYSTEM", "secret")
        or die ("Could not connect");
    fbsql_database_password($link, "secret db password");
    fbsql_select_db($database, $link);
?>

The return value can be one of the following constants:

FALSE - The exec handler for the host was invalid. This error will occur when the link_identifier connects directly to a database by using a port number. FBExec can be available on the server but no connection has been made for it.
FBSQL_UNKNOWN - The Status is unknown.
FBSQL_STOPPED - The database is not running. Use fbsql_start_db() to start the database.
FBSQL_STARTING - The database is starting.
FBSQL_RUNNING - The database is running and can be used to perform SQL operations.
FBSQL_STOPPING - The database is stopping.
FBSQL_NOEXEC - FBExec is not running on the server and it is not possible to get the status of the database.

fbsql_drop_db

(PHP 4 >= 4.0.6)

fbsql_drop_db -- Drop (delete) a FrontBase database

Description

fbsql_fetch_array() is an extended version of fbsql_fetch_row(). In addition to storing the data in the numeric indices of the result array, it also stores the data in associative indices, using the field names as keys.

If two or more columns of the result have the same field names, the last column will take precedence. To access the other column(s) of the same name, you must the numeric index of the column or make an alias for the column.

select t1.f1 as foo t2.f1 as bar from t1, t2

An important thing to note is that using fbsql_fetch_array() is NOT significantly slower than using fbsql_fetch_row(), while it provides a significant added value.

The optional second argument result_type in fbsql_fetch_array() is a constant and can take the following values: FBSQL_ASSOC, FBSQL_NUM, and FBSQL_BOTH.

For further details, see also fbsql_fetch_row() and fbsql_fetch_assoc().

Example 1. fbsql_fetch_array() example

<?php 
fbsql_connect ($host, $user, $password);
$result = fbsql_db_query ("database","select user_id, fullname from table");
while ($row = fbsql_fetch_array ($result)) {
    echo "user_id: ".$row["user_id"]."<br>\n";
    echo "user_id: ".$row[0]."<br>\n";
    echo "fullname: ".$row["fullname"]."<br>\n";
    echo "fullname: ".$row[1]."<br>\n";
}
fbsql_free_result ($result);
?>

fbsql_fetch_assoc

(PHP 4 >= 4.0.6)

fbsql_fetch_assoc -- Fetch a result row as an associative array

Description

array fbsql_fetch_assoc ( resource result)

Returns an associative array that corresponds to the fetched row, or FALSE if there are no more rows.

fbsql_fetch_assoc() is equivalent to calling fbsql_fetch_array() with FBSQL_ASSOC for the optional second parameter. It only returns an associative array. This is the way fbsql_fetch_array() originally worked. If you need the numeric indices as well as the associative, use fbsql_fetch_array().

If two or more columns of the result have the same field names, the last column will take precedence. To access the other column(s) of the same name, you must use fbsql_fetch_array() and have it return the numeric indices as well.

An important thing to note is that using fbsql_fetch_assoc() is NOT significantly slower than using fbsql_fetch_row(), while it provides a significant added value.

For further details, see also fbsql_fetch_row() and fbsql_fetch_array().

Example 1. fbsql_fetch_assoc() example

<?php 
fbsql_connect ($host, $user, $password);
$result = fbsql_db_query ("database","select * from table");
while ($row = fbsql_fetch_assoc ($result)) {
    echo $row["user_id"];
    echo $row["fullname"];
}
fbsql_free_result ($result);
?>

fbsql_fetch_field

(PHP 4 >= 4.0.6)

fbsql_fetch_field -- Get column information from a result and return as an object

Description

object fbsql_fetch_field ( resource result [, int field_offset])

Returns an object containing field information.

fbsql_fetch_field() can be used in order to obtain information about fields in a certain query result. If the field offset isn't specified, the next field that wasn't yet retrieved by fbsql_fetch_field() is retrieved.

The properties of the object are:

name - column name
table - name of the table the column belongs to
max_length - maximum length of the column
not_null - 1 if the column cannot be NULL
type - the type of the column

Example 1. fbsql_fetch_field() example

<?php 
fbsql_connect ($host, $user, $password)
    or die ("Could not connect");
$result = fbsql_db_query ("database", "select * from table")
    or die ("Query failed");
# get column metadata
$i = 0;
while ($i < fbsql_num_fields ($result)) {
    echo "Information for column $i:<BR>\n";
    $meta = fbsql_fetch_field ($result);
    if (!$meta) {
        echo "No information available<BR>\n";
    }
    echo "<PRE>
max_length:   $meta->max_length
name:         $meta->name
not_null:     $meta->not_null
table:        $meta->table
type:         $meta->type
</PRE>";
    $i++;
}
fbsql_free_result ($result);
?>

fbsql_fetch_lengths

(PHP 4 >= 4.0.6)

fbsql_fetch_lengths -- Get the length of each output in a result

Description

array fbsql_fetch_lengths ( [resource result])

Returns: An array that corresponds to the lengths of each field in the last row fetched by fbsql_fetch_row(), or FALSE on error.

fbsql_fetch_lengths() stores the lengths of each result column in the last row returned by fbsql_fetch_row(), fbsql_fetch_array() and fbsql_fetch_object() in an array, starting at offset 0.

fbsql_fetch_object

(PHP 4 >= 4.0.6)

fbsql_fetch_object -- Fetch a result row as an object

Description

object fbsql_fetch_object ( resource result [, int result_type])

Returns an object with properties that correspond to the fetched row, or FALSE if there are no more rows.

fbsql_fetch_object() is similar to fbsql_fetch_array(), with one difference - an object is returned, instead of an array. Indirectly, that means that you can only access the data by the field names, and not by their offsets (numbers are illegal property names).

The optional argument result_type is a constant and can take the following values: FBSQL_ASSOC, FBSQL_NUM, and FBSQL_BOTH.

Speed-wise, the function is identical to fbsql_fetch_array(), and almost as quick as fbsql_fetch_row() (the difference is insignificant).
Example 1. fbsql_fetch_object() example
<?php fbsql_connect ($host, $user, $password); $result = fbsql_db_query ("database", "select * from table"); while ($row = fbsql_fetch_object ($result)) { echo $row->user_id; echo $row->fullname; } fbsql_free_result ($result); ?>

fbsql_fetch_row

(PHP 4 >= 4.0.6)

fbsql_fetch_row -- Get a result row as an enumerated array

Description

array fbsql_fetch_row ( resource result)

Returns: An array that corresponds to the fetched row, or FALSE if there are no more rows.

fbsql_fetch_row() fetches one row of data from the result associated with the specified result identifier. The row is returned as an array. Each result column is stored in an array offset, starting at offset 0.

fbsql_field_name() returns the name of the specified field index. result must be a valid result identifier and field_index is the numerical offset of the field.

Note: field_index starts at 0.
e.g. The index of the third field would actually be 2, the index of the fourth field would be 3 and so on.

Example 1. fbsql_field_name() example
// The users table consists of three fields: // user_id // username // password. $res = fbsql_db_query("users", "select * from users", $link); echo fbsql_field_name($res, 0) . "\n"; echo fbsql_field_name($res, 2);

The above example would produce the following output:

user_id
password

fbsql_insert_id() returns 0 if the previous query does not generate an DEFAULT UNIQUE value. If you need to save the value for later, be sure to call fbsql_insert_id() immediately after the query that generates the value.

Note: The value of the FrontBase SQL function LAST_INSERT_ID() always contains the most recently generated DEFAULT UNIQUE value, and is not reset between queries.

fbsql_list_dbs

(PHP 4 >= 4.0.6)

fbsql_list_dbs -- List databases available on a FrontBase server

Description

resource fbsql_list_dbs ( [resource link_identifier])

fbsql_list_dbs() will return a result pointer containing the databases available from the current fbsql daemon. Use the fbsql_tablename() function to traverse this result pointer.

Example 1. fbsql_list_dbs() example
$link = fbsql_connect('localhost', 'myname', 'secret'); $db_list = fbsql_list_dbs($link); while ($row = fbsql_fetch_object($db_list)) { echo $row->Database . "\n"; }

The above example would produce the following output:

database1
database2
database3
...

Note: The above code would just as easily work with fbsql_fetch_row() or other similar functions.

fbsql_list_fields

(PHP 4 >= 4.0.6)

fbsql_list_fields -- List FrontBase result fields

Description

resource fbsql_list_fields ( string database_name, string table_name [, resource link_identifier])

fbsql_list_fields() retrieves information about the given tablename. Arguments are the database name and the table name. A result pointer is returned which can be used with fbsql_field_flags(), fbsql_field_len(), fbsql_field_name(), and fbsql_field_type().

A result identifier is a positive integer. The function returns -1 if a error occurs. A string describing the error will be placed in $phperrmsg, and unless the function was called as @fbsql() then this error string will also be printed out.

Example 1. fbsql_list_fields() example
$link = fbsql_connect('localhost', 'myname', 'secret'); $fields = fbsql_list_fields("database1", "table1", $link); $columns = fbsql_num_fields($fields); for ($i = 0; $i < $columns; $i++) { echo fbsql_field_name($fields, $i) . "\n";; }

The above example would produce the following output:

field1
field2
field3
...

fbsql_list_tables

(PHP 4 >= 4.0.6)

fbsql_list_tables -- List tables in a FrontBase database

Description

resource fbsql_list_tables ( string database [, resource link_identifier])

fbsql_list_tables() takes a database name and returns a result pointer much like the fbsql_db_query() function. The fbsql_tablename() function should be used to extract the actual table names from the result pointer.

fbsql_next_result

(PHP 4 >= 4.0.6)

fbsql_next_result -- Move the internal result pointer to the next result

Description

bool fbsql_next_result ( resource result_id)

When sending more than one SQL statement to the server or executing a stored procedure with multiple results will cause the server to return multiple result sets. This function will test for additional results available form the server. If an additional result set exists it will free the existing result set and prepare to fetch the words from the new result set. The function will return TRUE if an additional result set was available or FALSE otherwise.

Example 1. fbsql_next_result() example

<?php
    $link = fbsql_connect ("localhost", "_SYSTEM", "secret");
    fbsql_select_db("MyDB", $link);
    $SQL = "Select * from table1; select * from table2;";
    $rs = fbsql_query($SQL, $link);
    do {
        while ($row = fbsql_fetch_row($rs)) {
        }
    } while (fbsql_next_result($rs));
    fbsql_free_result($rs);
    fbsql_close ($link);
?>

This function is currently not documented; only the argument list is available.

fbsql_pconnect

(PHP 4 >= 4.0.6)

fbsql_pconnect -- Open a persistent connection to a FrontBase Server

Description

resource fbsql_pconnect ( [string hostname [, string username [, string password]]])

Returns: A positive FrontBase persistent link identifier on success, or FALSE on error.

fbsql_pconnect() establishes a connection to a FrontBase server. The following defaults are assumed for missing optional parameters: host = 'localhost', username = "_SYSTEM" and password = empty password.

fbsql_pconnect() acts very much like fbsql_connect() with two major differences.

To set Frontbase server port number, use fbsql_select_db().

First, when connecting, the function would first try to find a (persistent) link that's already open with the same host, username and password. If one is found, an identifier for it will be returned instead of opening a new connection.

Second, the connection to the SQL server will not be closed when the execution of the script ends. Instead, the link will remain open for future use.

This type of links is therefore called 'persistent'.

fbsql_query

(PHP 4 >= 4.0.6)

fbsql_query -- Send a FrontBase query

Description

resource fbsql_query ( string query [, resource link_identifier])

fbsql_query() sends a query to the currently active database on the server that's associated with the specified link identifier. If link_identifier isn't specified, the last opened link is assumed. If no link is open, the function tries to establish a link as if fbsql_connect() was called with no arguments, and use it.

Note: The query string shall always end with a semicolon.

mixed fbsql_result ( resource result, int row [, mixed field])

fbsql_result() returns the contents of one cell from a FrontBase result set. The field argument can be the field's offset, or the field's name, or the field's table dot field's name (tabledname.fieldname). If the column name has been aliased ('select foo as bar from...'), use the alias instead of the column name.

When working on large result sets, you should consider using one of the functions that fetch an entire row (specified below). As these functions return the contents of multiple cells in one function call, they're MUCH quicker than fbsql_result(). Also, note that specifying a numeric offset for the field argument is much quicker than specifying a fieldname or tablename.fieldname argument.

Calls to fbsql_result() should not be mixed with calls to other functions that deal with the result set.

Recommended high-performance alternatives: fbsql_fetch_row(), fbsql_fetch_array(), and fbsql_fetch_object().

fbsql_rollback

(PHP 4 >= 4.0.6)

fbsql_rollback -- Rollback a transaction to the database

Description

bool fbsql_rollback ( [resource link_identifier])

Returns TRUE on success or FALSE on failure.

fbsql_rollback() ends the current transaction by rolling back all statements issued since last commit. This command is only needed if autocommit is set to false.

fbsql_select_db

(PHP 4 >= 4.0.6)

fbsql_select_db -- Select a FrontBase database

Description

bool fbsql_select_db ( string database_name [, resource link_identifier])

Returns: TRUE on success, FALSE on error.

fbsql_select_db() sets the current active database on the server that's associated with the specified link identifier. If no link identifier is specified, the last opened link is assumed. If no link is open, the function will try to establish a link as if fbsql_connect() was called, and use it.

The client contacts FBExec to obtain the port number to use for the connection to the database. If the database name is a number the system will use that as a port number and it will not ask FBExec for the port number. The FrontBase server can be stared as FRontBase -FBExec=No -port=<port number> <database name>.

Every subsequent call to fbsql_query() will be made on the active database.

if the database is protected with a database password, the user must call fbsql_database_password() before selecting the database.

fbsql_set_lob_mode

(PHP 4 >= 4.2.0)

fbsql_set_lob_mode -- Set the LOB retrieve mode for a FrontBase result set

Description

bool fbsql_set_lob_mode ( resource result, string database_name)

Returns: TRUE on success, FALSE on error.

fbsql_set_lob_mode() sets the mode for retrieving LOB data from the database. When BLOB and CLOB data is stored in FrontBase it can be stored direct or indirect. Direct stored LOB data will always be fetched no matter the setting of the lob mode. If the LOB data is less than 512 bytes it will always be stored directly.

FBSQL_LOB_DIRECT - LOB data is retrieved directly. When data is fetched from the database with fbsql_fetch_row(), and other fetch functions, all CLOB and BLOB columns will be returned as ordinary columns. This is the default value on a new FrontBase result.
FBSQL_LOB_HANDLE - LOB data is retrieved as handles to the data. When data is fetched from the database with fbsql_fetch_row (), and other fetch functions, LOB data will be returned as a handle to the data if the data is stored indirect or the data if it is stored direct. If a handle is returned it will be a 27 byte string formatted as "@'000000000000000000000000'".

(PHP 4 >= 4.0.6)

fbsql_username -- Get or set the host user used with a connection

Description

string fbsql_username ( resource link_identifier [, string username])

Warning

This function is currently not documented; only the argument list is available.

fbsql_warnings

(PHP 4 >= 4.0.6)

fbsql_warnings -- Enable or disable FrontBase warnings

Description

bool fbsql_warnings ( [bool OnOff])

Returns TRUE if warnings is turned on otherwise FALSE.

fbsql_warnings() enables or disables FrontBase warnings.

XXIX. filePro functions

Introduction

These functions allow read-only access to data stored in filePro databases.

filePro is a registered trademark of fP Technologies, Inc. You can find more information about filePro at http://www.fptech.com/.

Table of Contents
filepro_fieldcount -- Find out how many fields are in a filePro database
filepro_fieldname -- Gets the name of a field
filepro_fieldtype -- Gets the type of a field
filepro_fieldwidth -- Gets the width of a field
filepro_retrieve -- Retrieves data from a filePro database
filepro_rowcount -- Find out how many rows are in a filePro database
filepro -- Read and verify the map file

Note: When safe mode is enabled, PHP checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.

filepro_rowcount

(PHP 3, PHP 4 )

filepro_rowcount -- Find out how many rows are in a filePro database

Description

int filepro_rowcount ( void)

Returns the number of rows in the opened filePro database.

Note: When safe mode is enabled, PHP checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.

filepro

(PHP 3, PHP 4 )

filepro -- Read and verify the map file

Description

bool filepro ( string directory)

This reads and verifies the map file, storing the field count and info.

No locking is done, so you should avoid modifying your filePro database while it may be opened in PHP.

Note: When safe mode is enabled, PHP checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.

XXX. Filesystem functions

Introduction

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Filesystem and Streams Configuration Options

Name	Default	Changeable
allow_url_fopen	"1"	PHP_INI_ALL
user_agent	NULL	PHP_INI_ALL
default_socket_timeout	"60"	PHP_INI_ALL
from	NULL	??
auto_detect_line_endings	"Off"	PHP_INI_ALL

Here is a short explanation of the configuration directives.

allow_url_fopen boolean

This option enables the URL-aware fopen wrappers that enable accessing URL object like files. Default wrappers are provided for the access of remote files using the ftp or http protocol, some extensions like zlib may register additional wrappers.

Note: This option was introduced immediately after the release of version 4.0.3. For versions up to and including 4.0.3 you can only disable this feature at compile time by using the configuration switch --disable-url-fopen-wrapper.

Warning

On Windows versions prior to PHP 4.3, the following functions do not support remote file accesing: include(), include_once(), require(), require_once() and the imagecreatefromXXX functions in the Reference XLI, Image functions extension.

user_agent string

Define the user agent for PHP to send.

default_socket_timeout integer

Default timeout (in seconds) for socket based streams.

Note: This configuration option was introduced in PHP 4.3.

from="joe@example.com" string

Define the anonymous ftp password (your email address).

auto_detect_line_endings boolean

When turned on, PHP will examine the data read by fgets() and file() to see if it is using Unix, MS-Dos or Macintosh line-ending conventions.

This enables PHP to interoperate with Macintosh systems, but defaults to Off, as there is a very small performance penalty when detecting the EOL conventions for the first line, and also because people using carriage-returns as item separators under Unix systems would experience non-backwards-compatible behaviour.

Note: This configuration option was introduced in PHP 4.3.

Resource Types

Predefined Constants

This extension has no constants defined.

basename

(PHP 3, PHP 4 )

basename -- Returns filename component of path

Description

string basename ( string path [, string suffix])

Given a string containing a path to a file, this function will return the base name of the file. If the filename ends in suffix this will also be cut off.

On Windows, both slash (/) and backslash (\) are used as path separator character. In other environments, it is the forward slash (/).

Example 1. basename() example
$path = "/home/httpd/html/index.php"; $file = basename ($path); // $file is set to "index.php" $file = basename ($path,".php"); // $file is set to "index"

Note: The suffix parameter was added in PHP 4.1.0.

chgrp

(PHP 3, PHP 4 )

chgrp -- Changes file group

Description

int chgrp ( string filename, mixed group)

Attempts to change the group of the file filename to group (specified by name or number). Only the superuser may change the group of a file arbitrarily; other users may change the group of a file to any group of which that user is a member.

Returns TRUE on success or FALSE on failure.

chmod

(PHP 3, PHP 4 )

chmod -- Changes file mode

Description

int chmod ( string filename, int mode)

Attempts to change the mode of the file specified by filename to that given in mode.

Note that mode is not automatically assumed to be an octal value, so strings (such as "g+w") will not work properly. To ensure the expected operation, you need to prefix mode with a zero (0):

chmod ("/somedir/somefile", 755);   // decimal; probably incorrect   
chmod ("/somedir/somefile", "u+rwx,go+rx"); // string; incorrect       
chmod ("/somedir/somefile", 0755);  // octal; correct value of mode

Returns TRUE on success or FALSE on failure.

chown

(PHP 3, PHP 4 )

chown -- Changes file owner

Description

int chown ( string filename, mixed user)

Attempts to change the owner of the file filename to user user (specified by name or number). Only the superuser may change the owner of a file.

Returns TRUE on success or FALSE on failure.

clearstatcache

(PHP 3, PHP 4 )

clearstatcache -- Clears file status cache

Description

void clearstatcache ( void)

When you use stat(), lstat(), or any of the other functions listed in the affected functions list (below), PHP caches the information those functions return in order to provide faster performance. However, in certain cases, you may want to clear the cached information. For instance, if the same file is being checked multiple times within a single script, and that file is in danger of being removed or changed during that script's operation, you may elect to clear the status cache. In these cases, you can use the clearstatcache() function to clear the information that PHP caches about a file.

Note: This function caches information about specific filenames, so you only need to call clearstatcache() if you are performing multiple operations on the same filename and require the information about that particular file to not be cached.

Affected functions include stat(), lstat(), file_exists(), is_writable(), is_readable(), is_executable(), is_file(), is_dir(), is_link(), filectime(), fileatime(), filemtime(), fileinode(), filegroup(), fileowner(), filesize(), filetype(), and fileperms().

copy

(PHP 3, PHP 4 )

copy -- Copies file

Description

int copy ( string source, string dest)

Makes a copy of a file. Returns TRUE if the copy succeeded, FALSE otherwise.
Example 1. copy() example
if (!copy($file, $file.'.bak')) { print ("failed to copy $file...<br>\n"); }

Note: As of PHP 4.3.0, both source and dest may be URLs if the "fopen wrappers" have been enabled. See fopen() for more details. If dest is an URL, the copy operation may fail if the wrapper does not support overwriting of existing files.

Warning

If the destination file already exists, it will be overwritten.

See also move_uploaded_file(), rename(), and the section of the manual about handling file uploads.

delete

(no version information, might be only in CVS)

delete -- See unlink() or unset()

Description

void delete ( string file)

This is a dummy manual entry to satisfy those people who are looking for unlink() or unset() in the wrong place.

See also: unlink() to delete files, unset() to delete variables.

dirname

(PHP 3, PHP 4 )

dirname -- Returns directory name component of path

Description

string dirname ( string path)

Given a string containing a path to a file, this function will return the name of the directory.

On Windows, both slash (/) and backslash (\) are used as path separator character. In other environments, it is the forward slash (/).

Example 1. dirname() example
$path = "/etc/passwd"; $file = dirname ($path); // $file is set to "/etc"

Note: In PHP 4.0.3, dirname() was fixed to be POSIX-compliant. Essentially, this means that if there are no slashes in path , a dot ('.') is returned, indicating the current directory. Otherwise, the returned string is path with any trailing /component removed. Note that this means that you will often get a slash or a dot back from dirname() in situations where the older functionality would have given you the empty string.

fclose

(PHP 3, PHP 4 )

fclose -- Closes an open file pointer

Description

bool fclose ( int fp)

The file pointed to by fp is closed.

array fgetcsv ( int fp, int length [, string delimiter [, string enclosure]])

Similar to fgets() except that fgetcsv() parses the line it reads for fields in CSV format and returns an array containing the fields read. The optional third delimiter parameter defaults as a comma. The optional enclosure cannot be null, and is limited to one character. If enclosure is more than one character, only the first character is used.

Note: The enclosure parameter was added in PHP 4.3.0.

The fp parameter must be a valid file pointer to a file successfully opened by fopen(), popen(), or fsockopen().

The length parameter must be greater than the longest line to be found in the CSV file (allowing for trailing line-end characters).

fgetcsv() returns FALSE on error, including end of file.

Note: A blank line in a CSV file will be returned as an array comprising a single null field, and will not be treated as an error.

Example 1. Read and print the entire contents of a CSV file
<?php $row = 1; $fp = fopen ("test.csv","r"); while ($data = fgetcsv ($fp, 1000, ",")) { $num = count ($data); print "<p> $num fields in line $row: <br>\n"; $row++; for ($c=0; $c < $num; $c++) { print $data[$c] . "<br>\n"; } } fclose ($fp); ?>

See also explode(), file(), and pack()

fgets

(PHP 3, PHP 4 )

fgets -- Gets line from file pointer

Description

string fgets ( int fp [, int length])

Returns a string of up to length - 1 bytes read from the file pointed to by fp. Reading ends when length - 1 bytes have been read, on a newline (which is included in the return value), or on EOF (whichever comes first). If no length is specified, the length defaults to 1k, or 1024 bytes.

If an error occurs, returns FALSE.

Common Pitfalls:

People used to the 'C' semantics of fgets() should note the difference in how EOF is returned.

The file pointer must be valid, and must point to a file successfully opened by fopen(), popen(), or fsockopen().

A simple example follows:
Example 1. Reading a file line by line
$fd = fopen ("/tmp/inputfile.txt", "r"); while (!feof ($fd)) { $buffer = fgets($fd, 4096); echo $buffer; } fclose ($fd);

Note: The length parameter became optional in PHP 4.2.0, if omitted, it would assume 1024 as the line length. As of PHP 4.3, omitting length will keep reading from the stream until it reaches the end of the line. If the majority of the lines in the file are all larger than 8KB, it is more resource efficient for your script to specify the maximum line length.

Note: This function is binary safe as of PHP 4.3. Earlier versions were not binary safe.

Note: If you are having problems with PHP not recognizing the line endings when reading files either on or created by a Macintosh computer, you might want to enable the auto_detect_line_endings run-time configuration option.

fgetss

(PHP 3, PHP 4 )

fgetss -- Gets line from file pointer and strip HTML tags

Description

string fgetss ( int fp, int length [, string allowable_tags])

Identical to fgets(), except that fgetss attempts to strip any HTML and PHP tags from the text it reads.

You can use the optional third parameter to specify tags which should not be stripped.

Note: allowable_tags was added in PHP 3.0.13, PHP 4.0.0.

Note: If you are having problems with PHP not recognizing the line endings when reading files either on or created by a Macintosh computer, you might want to enable the auto_detect_line_endings run-time configuration option.

file_exists

(PHP 3, PHP 4 )

file_exists -- Checks whether a file exists

Description

bool file_exists ( string filename)

Returns TRUE if the file specified by filename exists; FALSE otherwise.

This function will not work on remote files; the file to be examined must be accessible via the server's filesystem.

The results of this function are cached. See clearstatcache() for more details.

Using Windows shares: On windows, use //computername/share/filename or \\\\computername\share\filename to check files on network shares.

Example 1. Testing whether a file exists
<?php $filename = '/path/to/foo.txt'; if (file_exists($filename)) { print "The file $filename exists"; } else { print "The file $filename does not exist"; } ?>

file_get_contents

(PHP 4 CVS only)

file_get_contents -- Reads entire file into a string

Description

string file_get_contents ( string filename [, int use_include_path])

Identical to readfile(), except that file_get_contents() returns the file in a string.

Note: This function is binary-safe.

Tip: You can use a URL as a filename with this function if the fopen wrappers have been enabled. See fopen() for more details on how to specify the filename and Appendix I for a list of supported URL protocols.

file

(PHP 3, PHP 4 )

file -- Reads entire file into an array

Description

array file ( string filename [, int use_include_path])

Identical to readfile(), except that file() returns the file in an array. Each element of the array corresponds to a line in the file, with the newline still attached.

Note: Each line in the resulting array will include the line ending, so you still need to use trim() if you do not want the line ending present.

Note: If you are having problems with PHP not recognizing the line endings when reading files either on or created by a Macintosh computer, you might want to enable the auto_detect_line_endings run-time configuration option.

You can use the optional second parameter and set it to "1", if you want to search for the file in the include_path, too.

<?php
// Get a file into an array.  In this example we'll go through HTTP to get 
// the HTML source of a URL.
$lines = file ('http://www.example.com/');

// Loop through our array, show html source as html source; and line numbers too.
foreach ($lines as $line_num => $line) {
    echo "Line #<b>{$line_num}</b> : " . htmlspecialchars($line) . "<br>\n";
}

// Another example, let's get a web page into a string.  See also file_get_contents().
$html = implode ('', file ('http://www.example.com/'));
?>

Note: As of PHP 4.3.0 you can use file_get_contents() to return the contents of a file as a string.
In PHP 4.3.0 file() became binary safe.

Tip: You can use a URL as a filename with this function if the fopen wrappers have been enabled. See fopen() for more details on how to specify the filename and Appendix I for a list of supported URL protocols.

fileatime

(PHP 3, PHP 4 )

fileatime -- Gets last access time of file

Description

int fileatime ( string filename)

Returns the time the file was last accessed, or FALSE in case of an error. The time is returned as a Unix timestamp.

The results of this function are cached. See clearstatcache() for more details.

Note: The atime of a file is supposed to change whenever the data blocks of a file are being read. This can be costly performancewise when an application regularly accesses a very large number of files or directories. Some Unix filesystems can be mounted with atime updates disabled to increase the performance of such applications; USENET news spools are a common example. On such filesystems this function will be useless.

This function will not work on remote files; the file to be examined must be accessible via the server's filesystem.

filectime

(PHP 3, PHP 4 )

filectime -- Gets inode change time of file

Description

int filectime ( string filename)

Returns the time the file was last changed, or FALSE in case of an error. The time is returned as a Unix timestamp.

int filemtime ( string filename)

Returns the time the file was last modified, or FALSE in case of an error. The time is returned as a Unix timestamp.

string filetype ( string filename)

Returns the type of the file. Possible values are fifo, char, dir, block, link, file, and unknown.

Returns FALSE if an error occurs.

The results of this function are cached. See clearstatcache() for more details.

This function will not work on remote files; the file to be examined must be accessible via the server's filesystem.

flock

(PHP 3>= 3.0.7, PHP 4 )

flock -- Portable advisory file locking

Description

bool flock ( int fp, int operation [, int &wouldblock])

PHP supports a portable way of locking complete files in an advisory way (which means all accessing programs have to use the same way of locking or it will not work).

flock() operates on fp which must be an open file pointer. operation is one of the following values:

To acquire a shared lock (reader), set operation to LOCK_SH (set to 1 prior to PHP 4.0.1).
To acquire an exclusive lock (writer), set operation to LOCK_EX (set to 2 prior to PHP 4.0.1).
To release a lock (shared or exclusive), set operation to LOCK_UN (set to 3 prior to PHP 4.0.1).
If you don't want flock() to block while locking, add LOCK_NB (4 prior to PHP 4.0.1) to operation.

flock() allows you to perform a simple reader/writer model which can be used on virtually every platform (including most Unix derivatives and even Windows). The optional third argument is set to TRUE if the lock would block (EWOULDBLOCK errno condition)

flock() returns TRUE on success and FALSE on error (e.g. when a lock could not be acquired).

Note: Because flock() requires a file pointer, you may have to use a special lock file to protect access to a file that you intend to truncate by opening it in write mode (with a "w" or "w+" argument to fopen()).

Warning

flock() will not work on NFS and many other networked file systems. Check your operating system documentation for more details.

On some operating systems flock() is implemented at the process level. When using a multithreaded server API like ISAPI you may not be able to rely on flock() to protect files against other PHP scripts running in parallel threads of the same server instance!

flock() is not supported on antiquated filesystems like FAT and its derivates and will therefore always return FALSE under this environments (this is especially true for Windows 98 users).

fnmatch

(PHP 4 CVS only)

fnmatch -- Match filename against a pattern

Description

array fnmatch ( string pattern, string string [, int flags])

fnmatch() checks if the passed string would match the given shell wildcard pattern.

This is especialy usefull for filenames, but may also be used on regular strings. The average user may be used to shell patterns or at least in their simplest form to '?' and '*' wildcards so using fnmatch() instead of ereg() or preg_match() for frontend search expression input may be way more convenient for non-programming users.

Example 1. Checking a color name against a shell wildcard pattern.

if(fnmatch("*gr[ae]y", $color)) {
  echo "some form of gray ...";
}

See also glob(), ereg(), preg_match() and the unix manpage on fnmatch(3) for flag names (as long as they are not documented here ).

fopen

(PHP 3, PHP 4 )

fopen -- Opens file or URL

Description

int fopen ( string filename, string mode [, int use_include_path [, resource zcontext]])

fopen() binds a named resource, specified by filename, to a stream. If filename is of the form "scheme://...", it is assumed to be a URL and PHP will search for a protocol handler (also known as a wrapper) for that scheme. If no wrappers for that protocol are registered, PHP will emit a notice to help you track potential problems in your script and then continue as though filename specifies a regular file.

If PHP has decided that filename specifies a local file, then it will try to open a stream on that file. The file must be accessible to PHP, so you need to ensure that the file access permissions allow this access. If you have enabled safe_mode, or open_basedir further restrictions may apply.

If PHP has decided that filename specifies a registered protocol, and that protocol is registered as a network URL, PHP will check to make sure that allow_url_fopen is enabled. If it is switched off, PHP will emit a warning and the fopen call will fail.

Note: The list of supported protocols can be found in Appendix I.

mode specifies the type of access you require to the stream. It may be any of the following:

'r' - Open for reading only; place the file pointer at the beginning of the file.
'r+' - Open for reading and writing; place the file pointer at the beginning of the file.
'w' - Open for writing only; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.
'w+' - Open for reading and writing; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.
'a' - Open for writing only; place the file pointer at the end of the file. If the file does not exist, attempt to create it.
'a+' - Open for reading and writing; place the file pointer at the end of the file. If the file does not exist, attempt to create it.

Note: The mode may contain the letter 'b'. This is useful only on systems which differentiate between binary and text files (i.e. Windows. It's useless on Unix). If not needed, this will be ignored. You are encouraged to include the 'b' flag in order to make your scripts more portable.

The optional third use_include_path parameter can be set to '1' or TRUE if you want to search for the file in the include_path, too.

The optional fourth zcontext is used for specifying tuning parameters and callbacks.

If the open fails, the function returns FALSE.

Example 1. fopen() example
<?php $fp = fopen ("/home/rasmus/file.txt", "r"); $fp = fopen ("/home/rasmus/file.gif", "wb"); $fp = fopen ("http://www.example.com/", "r"); $fp = fopen ("ftp://user:password@example.com/", "w"); ?>

If you are experiencing problems with reading and writing to files and you're using the server module version of PHP, remember to make sure that the files and directories you're using are accessible to the server process.

On the Windows platform, be careful to escape any backslashes used in the path to the file, or use forward slashes.

<?php
$fp = fopen ("c:\\data\\info.txt", "r");
?>

fpassthru

(PHP 3, PHP 4 )

fpassthru -- Output all remaining data on a file pointer

Description

int fpassthru ( int fp)

Reads to EOF on the given file pointer from the current position and writes the results to the output buffer.

If an error occurs, fpassthru() returns FALSE.

The file pointer must be valid, and must point to a file successfully opened by fopen(), popen(), or fsockopen(). You may need to call rewind() to reset the file pointer to the beginning of the file if you have already written data to the file. The file is closed when fpassthru() is done reading it (leaving fp useless).

If you just want to dump the contents of a file to the output buffer, without first modifying it or seeking to a particular offset, you may want to use the readfile(), which saves you the fopen() call.

Note: When using fpassthru() on a binary file on Windows systems, you should make sure to open the file in binary mode by appending a b to the mode used in the call to fopen().
You are encouraged to use the b flag when dealing with binary files, even if your system does not require it, so that your scripts will be more portable.

fputs

(PHP 3, PHP 4 )

fputs -- Writes to a file pointer

Description

int fputs ( int fp, string str [, int length])

fputs() is an alias to fwrite(), and is identical in every way. Note that the length parameter is optional and if not specified the entire string will be written.

fread

(PHP 3, PHP 4 )

fread -- Binary-safe file read

Description

string fread ( int fp, int length)

fread() reads up to length bytes from the file pointer referenced by fp. Reading stops when length bytes have been read or EOF is reached, whichever comes first.

// get contents of a file into a string
$filename = "/usr/local/something.txt";
$fd = fopen ($filename, "r");
$contents = fread ($fd, filesize ($filename));
fclose ($fd);

Note: On systems which differentiate between binary and text files (i.e. Windows) the file must be opened with 'b' included in fopen() mode parameter.

$filename = "c:\\files\\somepic.gif";
$fd = fopen ($filename, "rb");
$contents = fread ($fd, filesize ($filename));
fclose ($fd);

fscanf

(PHP 4 >= 4.0.1)

fscanf -- Parses input from a file according to a format

Description

mixed fscanf ( int handle, string format [, string var1])

The function fscanf() is similar to sscanf(), but it takes its input from a file associated with handle and interprets the input according to the specified format. If only two parameters were passed to this function, the values parsed will be returned as an array. Otherwise, if optional parameters are passed, the function will return the number of assigned values. The optional parameters must be passed by reference.

Any whitespace in the format string matches any whitespace in the input stream. This means that even a tab \t in the format string can match a single space character in the input stream.

Example 1. fscanf() Example
$fp = fopen ("users.txt","r"); while ($userinfo = fscanf ($fp, "%s\t%s\t%s\n")) { list ($name, $profession, $countrycode) = $userinfo; //... do something with the values } fclose($fp);

Example 2. users.txt
javier argonaut pe hiroshi sculptor jp robert slacker us luigi florist it

fseek

(PHP 3, PHP 4 )

fseek -- Seeks on a file pointer

Description

int fseek ( int fp, int offset [, int whence])

Sets the file position indicator for the file referenced by fp.The new position, measured in bytes from the beginning of the file, is obtained by adding offset to the position specified by whence, whose values are defined as follows:

SEEK_SET - Set position equal to offset bytes.

SEEK_CUR - Set position to current location plus offset.

SEEK_END - Set position to end-of-file plus offset. (To move to a position before the end-of-file, you need to pass a negative value in offset.)

If whence is not specified, it is assumed to be SEEK_SET.

Upon success, returns 0; otherwise, returns -1. Note that seeking past EOF is not considered an error.

May not be used on file pointers returned by fopen() if they use the "http://" or "ftp://" formats.

Note: The whence argument was added after PHP 4.0.0.

fstat

(PHP 4 )

fstat -- Gets information about a file using an open file pointer

Description

array fstat ( int fp)

Gathers the statistics of the file opened by the file pointer fp. This function is similar to the stat() function except that it operates on an open file pointer instead of a filename.

Returns an array with the statistics of the file with the following elements:

device
inode
number of links
user id of owner
group id owner
device type if inode device *
size in bytes
time of last access
time of last modification
time of last change
blocksize for filesystem I/O *
number of blocks allocated

* - only valid on systems supporting the st_blksize type--other systems (i.e. Windows) return -1

The results of this function are cached. See clearstatcache() for more details.

ftell

(PHP 3, PHP 4 )

ftell -- Tells file pointer read/write position

Description

int ftell ( int fp)

Returns the position of the file pointer referenced by fp; i.e., its offset into the file stream.

If an error occurs, returns FALSE.

The file pointer must be valid, and must point to a file successfully opened by fopen() or popen().

See also fopen(), popen(), fseek(), and rewind().

ftruncate

(PHP 4 )

ftruncate -- Truncates a file to a given length

Description

int ftruncate ( int fp, int size)

Takes the filepointer, fp, and truncates the file to length, size. This function returns TRUE on success and FALSE on failure.

fwrite

(PHP 3, PHP 4 )

fwrite -- Binary-safe file write

Description

int fwrite ( int fp, string string [, int length])

fwrite() writes the contents of string to the file stream pointed to by fp. If the length argument is given, writing will stop after length bytes have been written or the end of string is reached, whichever comes first.

fwrite() returns the number of bytes written, or -1 on error.

Note that if the length argument is given, then the magic_quotes_runtime configuration option will be ignored and no slashes will be stripped from string.

Note: On systems which differentiate between binary and text files (i.e. Windows) the file must be opened with 'b' included in fopen() mode parameter.

Example 1. A simple fwrite example
<?php $filename = 'test.txt'; $somecontent = "Add this to the file\n"; // Let's make sure the file exists and is writable first. if (is_writable($filename)) { // In our example we're opening $filename in append mode. // The file pointer is at the bottom of the file hence // that's where $somecontent will go when we fwrite() it. if (!$fp = fopen($filename, 'a')) { print "Cannot open file ($filename)"; exit; } // Write $somecontent to our opened file. if (!fwrite($fp, $somecontent)) { print "Cannot write to file ($filename)"; exit; } print "Success, wrote ($somecontent) to file ($filename)"; fclose($fp); } else { print "The file $filename is not writable"; } ?>

glob

(PHP 4 CVS only)

glob -- Find pathnames matching a pattern

Description

array glob ( string pattern [, int flags])

The glob() function searches for all the pathnames matching pattern according to the rules used by the shell. No tilde expansion or parameter substitution is done.

Returns an array containing the matched files/directories or FALSE on error.

Example 1. Convenient way how glob() can replace opendir() and friends.

foreach (glob("*.txt") as $filename) {
    echo "$filename size " . filesize($filename) . "\n";
}

This could result in the following output:

funclist.txt size 44686
funcsummary.txt size 267625
quickref.txt size 137820

See also opendir(), readdir() and closedir(), fnmatch() and the unix manpage on glob(3) for flag names (as long as they are not documented here ).

is_dir

(PHP 3, PHP 4 )

is_dir -- Tells whether the filename is a directory

Description

bool is_dir ( string filename)

Returns TRUE if the filename exists and is a directory. If filename is a relative filename, it will be checked relative to the current working directory.

The results of this function are cached. See clearstatcache() for more details.

This function will not work on remote files; the file to be examined must be accessible via the server's filesystem.

is_executable

(PHP 3, PHP 4 )

is_executable -- Tells whether the filename is executable

Description

bool is_executable ( string filename)

Returns TRUE if the filename exists and is executable.

The results of this function are cached. See clearstatcache() for more details.

This function will not work on remote files; the file to be examined must be accessible via the server's filesystem.

Note: This function is not available on Win32.

Note: The following example will not work in versions of PHP 4 after 4.0.2. It depends on internal functionality of PHP which changed after that version.

<?php
/* Userland test for uploaded file. */
function is_uploaded_file($filename) {
    if (!$tmp_file = get_cfg_var('upload_tmp_dir')) {
        $tmp_file = dirname(tempnam('', ''));
    }
    $tmp_file .= '/' . basename($filename);
    /* User might have trailing slash in php.ini... */
    return (ereg_replace('/+', '/', $tmp_file) == $filename);
}

/* This is how to use it, since you also don't have
 * move_uploaded_file() in these older versions: */
if (is_uploaded_file($HTTP_POST_FILES['userfile'])) {
    copy($HTTP_POST_FILES['userfile'], "/place/to/put/uploaded/file");
} else {
    echo "Possible file upload attack: filename '$HTTP_POST_FILES[userfile]'.";
}
?>

See also move_uploaded_file(), and the section Handling file uploads for a simple usage example.

is_writable

(PHP 4 )

is_writable -- Tells whether the filename is writable

Description

bool is_writable ( string filename)

Returns TRUE if the filename exists and is writable. The filename argument may be a directory name allowing you to check if a directory is writeable.

Keep in mind that PHP may be accessing the file as the user id that the web server runs as (often 'nobody'). Safe mode limitations are not taken into account.

The results of this function are cached. See clearstatcache() for more details.

This function will not work on remote files; the file to be examined must be accessible via the server's filesystem.

is_writeable

(PHP 3, PHP 4 )

is_writeable -- Tells whether the filename is writable

array lstat ( string filename)

Gathers the statistics of the file or symbolic link named by filename. This function is identical to the stat() function except that if the filename parameter is a symbolic link, the status of the symbolic link is returned, not the status of the file pointed to by the symbolic link.

Returns an array with the statistics of the file with the following elements:

device
inode
inode protection mode
number of links
user id of owner
group id owner
device type if inode device *
size in bytes
time of last access
time of last modification
time of last change
blocksize for filesystem I/O *
number of blocks allocated

* - only valid on systems supporting the st_blksize type--other systems (i.e. Windows) return -1.

lstat() cannot be used on remote files.

The results of this function are cached. See clearstatcache() for more details.

mkdir

(PHP 3, PHP 4 )

mkdir -- Makes directory

Description

int mkdir ( string pathname, int mode)

Attempts to create the directory specified by pathname.

Note that you probably want to specify the mode as an octal number, which means it should have a leading zero. The mode is also modified by the current umask, which you can change using umask().

mkdir ("/path/to/my/dir", 0700);

Returns TRUE on success or FALSE on failure.

move_uploaded_file

(PHP 4 >= 4.0.3)

move_uploaded_file -- Moves an uploaded file to a new location

Description

bool move_uploaded_file ( string filename, string destination)

This function checks to ensure that the file designated by filename is a valid upload file (meaning that it was uploaded via PHP's HTTP POST upload mechanism). If the file is valid, it will be moved to the filename given by destination.

If filename is not a valid upload file, then no action will occur, and move_uploaded_file() will return FALSE.

If filename is a valid upload file, but cannot be moved for some reason, no action will occur, and move_uploaded_file() will return FALSE. Additionally, a warning will be issued.

This sort of check is especially important if there is any chance that anything done with uploaded files could reveal their contents to the user, or even to other users on the same system.

Note: When safe mode is enabled, PHP checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.

Note: move_uploaded_file() is not affected by the normal safe-mode UID-restrictions. This is not unsafe because move_uploaded_file() only operates on files uploaded via PHP.

Warning

If the destination file already exists, it will be overwritten.

See also is_uploaded_file(), and the section Handling file uploads for a simple usage example.

parse_ini_file

(PHP 4 )

parse_ini_file -- Parse a configuration file

Description

array parse_ini_file ( string filename [, bool process_sections])

parse_ini_file() loads in the ini file specified in filename, and returns the settings in it in an associative array. By setting the last process_sections parameter to TRUE, you get a multidimensional array, with the section names and settings included. The default for process_sections is FALSE

Note: This function has nothing to do with the php.ini file. It is already processed, the time you run your script. This function can be used to read in your own application's configuration files.

Note: If a value in the ini file contains any non-alphanumeric characters it needs to be enclosed in double-quotes (").

Note: Since PHP 4.2.1 this function is also affected by safe_mode and open_basedir.

The structure of the ini file is similar to that of the php.ini's.

Warning

If the ini file you are trying to parse is malformed, PHP will exit.

Example 1. Contents of sample.ini
; This is a sample configuration file ; Comments start with ';', as in php.ini [first_section] one = 1 five = 5 [second_section] path = /usr/local/bin URL = "http://www.example.com/~username"

Example 2. parse_ini_file() example
<?php // Parse without sections $ini_array = parse_ini_file("sample.ini"); print_r($ini_array); // Parse with sections $ini_array = parse_ini_file("sample.ini", TRUE); print_r($ini_array); ?>

Would produce:

Array
(
    [one] => 1
    [five] => 5
    [path] => /usr/local/bin
    [URL] => http://www.example.com/~username
)
Array
(
    [first_section] => Array
        (
            [one] => 1
            [five] => 5
        )

    [second_section] => Array
        (
            [path] => /usr/local/bin
            [URL] => http://www.example.com/~username
        )

)

pathinfo

(PHP 4 >= 4.0.3)

pathinfo -- Returns information about a file path

Description

array pathinfo ( string path)

pathinfo() returns an associative array containing information about path. The following array elements are returned: dirname, basename and extension.

Example 1. pathinfo() Example
<?php $path_parts = pathinfo("/www/htdocs/index.html"); echo $path_parts["dirname"] . "\n"; echo $path_parts["basename"] . "\n"; echo $path_parts["extension"] . "\n"; ?>

Would produce:

/www/htdocs
index.html
html

Note: For information on retrieving the current path info, read the section on predefined reserved variables.

pclose

(PHP 3, PHP 4 )

pclose -- Closes process file pointer

Description

int pclose ( int fp)

Closes a file pointer to a pipe opened by popen().

The file pointer must be valid, and must have been returned by a successful call to popen().

Returns the termination status of the process that was run.

popen

(PHP 3, PHP 4 )

popen -- Opens process file pointer

Description

int popen ( string command, string mode)

Opens a pipe to a process executed by forking the command given by command.

Returns a file pointer identical to that returned by fopen(), except that it is unidirectional (may only be used for reading or writing) and must be closed with pclose(). This pointer may be used with fgets(), fgetss(), and fputs().

If an error occurs, returns FALSE.

Note: If you're looking for bi-directional support (two-way), use proc_open().

<?php
$fp = popen ("/bin/ls", "r");
?>

Note: If the command to be executed could not be found, a valid resource is returned. This may seem odd, but makes sense; it allows you to access any error message returned by the shell:
<?php
error_reporting(E_ALL);

/* Add redirection so we can get stderr. */
$fp = popen('/path/to/spooge 2>&1', 'r');
echo "'$fp'; " . gettype($fp) . "\n";
$read = fread($fp, 2096);
echo $read;
pclose($fp);
?>

See also pclose(), fopen(), and proc_open().

readfile

(PHP 3, PHP 4 )

readfile -- Outputs a file

Description

int readfile ( string filename [, int use_include_path])

Reads a file and writes it to the output buffer.

Returns the number of bytes read from the file. If an error occurs, FALSE is returned and unless the function was called as @readfile, an error message is printed.

Tip: You can use a URL as a filename with this function if the fopen wrappers have been enabled. See fopen() for more details on how to specify the filename and Appendix I for a list of supported URL protocols.

You can use the optional second parameter and set it to "1", if you want to search for the file in the include_path, too.

readlink

(PHP 3, PHP 4 )

readlink -- Returns the target of a symbolic link

Description

string readlink ( string path)

readlink() does the same as the readlink C function and returns the contents of the symbolic link path or 0 in case of error.

See also is_link(), symlink(), and linkinfo().

realpath

(PHP 4 )

realpath -- Returns canonicalized absolute pathname

Description

string realpath ( string path)

realpath() expands all symbolic links and resolves references to '/./', '/../' and extra '/' characters in the input path and return the canonicalized absolute pathname. The resulting path will have no symbolic link, '/./' or '/../' components.

realpath() returns FALSE on failure, e.g. if the file does not exists.

Example 1. realpath() example
$real_path = realpath ("../../index.php");

See also: basename(), dirname(), and pathinfo().

rename

(PHP 3, PHP 4 )

rename -- Renames a file

Description

bool rename ( string oldname, string newname)

Attempts to rename oldname to newname.

Returns TRUE on success or FALSE on failure.
Example 1. Example with rename()
<?php rename("/tmp/tmp_file.txt", "/home/user/login/docs/my_file.txt"); ?>

rewind

(PHP 3, PHP 4 )

rewind -- Rewind the position of a file pointer

Description

int rewind ( int fp)

Sets the file position indicator for fp to the beginning of the file stream.

If an error occurs, returns 0, otherwise it returns 1.

The file pointer must be valid, and must point to a file successfully opened by fopen().

Note: If you have opened the file in append ("a") mode, any data you write to the file will always be appended, regardless of the file position.

rmdir

(PHP 3, PHP 4 )

rmdir -- Removes directory

Description

bool rmdir ( string dirname)

Attempts to remove the directory named by dirname. The directory must be empty, and the relevant permissions must permit this. Returns TRUE on success or FALSE on failure.

set_file_buffer

set_file_buffer -- Alias of stream_set_write_buffer()

Description

This function is an alias of stream_set_write_buffer().

stat

(PHP 3, PHP 4 )

stat -- Gives information about a file

Description

array stat ( string filename)

Gathers the statistics of the file named by filename.

Returns an array with the statistics of the file with the following elements:

device
inode
inode protection mode
number of links
user id of owner
group id owner
device type if inode device *
size in bytes
time of last access
time of last modification
time of last change
blocksize for filesystem I/O *
number of blocks allocated

* - only valid on systems supporting the st_blksize type--other systems (i.e. Windows) return -1.

Returns FALSE in case of error.

stat() cannot be used on remote files.

The results of this function are cached. See clearstatcache() for more details.

stream_get_meta_data

(no version information, might be only in CVS)

stream_get_meta_data -- Retrieves header/meta data from streams/file pointers

Description

array file_get_meta_data ( resource stream)

Returns information about an existing stream. The stream can be any stream created by fopen(), fsockopen() and pfsockopen(). The result array contains the following items:

timed_out (bool) - TRUE if the stream timed out while waiting for data on the last call to fread() or fgets().
blocked (bool) - TRUE if the stream is in blocking IO mode. See socket_set_blocking().
eof (bool) - TRUE if the stream has reached end-of-file. Note that for socket streams this member can be TRUE even when unread_bytes is non-zero. To determine if there is more data to be read, use feof() instead of reading this item.
unread_bytes (int) - the number of bytes currently contained in the read buffer.

The following items were added in PHP 4.3:

stream_type (string) - a label describing the underlying implementation of the stream.
wrapper_type (string) - a label describing the protocol wrapper implementation layered over the stream. See Appendix I for more information about wrappers.
wrapper_data (mixed) - wrapper specific data attached to this stream. See Appendix I for more information about wrappers and their wrapper data.
filters (array) - and array containing the names of any filters that have been stacked onto this stream. Filters are currently undocumented.

Note: This function was introduced in PHP 4.3, but prior to this version, socket_get_status() could be used to retrieve the first four items, for socket based streams only.
In PHP 4.3 and later, socket_get_status() is an alias for this function.

Note: This function does NOT work on sockets created by the Socket extension.

stream_register_wrapper

(no version information, might be only in CVS)

stream_register_wrapper -- Register a URL wrapper implemented as a PHP class

Description

boolean stream_register_wrapper ( string protocol, string classname)

stream_register_wrapper() allows you to implement your own protocol handlers and streams for use with all the other filesystem functions (such as fopen(), fread() etc.).

To implement a wrapper, you need to define a class with a number of member functions, as defined below. When someone fopens your stream, PHP will create an instance of classname and then call methods on that instance. You must implement the methods exactly as described below - doing otherwise will lead to undefined behaviour.

stream_register_wrapper() will return FALSE if the protocol already has a handler.

boolean stream_open ( string path, string mode, int options, string opened_path)

This method is called immediately after your stream object is created. path specifies the URL that was passed to fopen() and that this object is expected to retrieve. You can use parse_url() to break it apart.

mode is the mode used to open the file, as detailed for fopen(). You are responsible for checking that mode is valid for the path requested.

options holds additional flags set by the streams API. It can hold one or more of the following values OR'd together.

Flag	Description
STREAM_USE_PATH	If `path` is relative, search for the resource using the include_path.
STREAM_REPORT_ERRORS	If this flag is set, you are responsible for raising errors using trigger_error() during opening of the stream. If this flag is not set, you should not raise any errors.

If the path is opened successfully, and STREAM_USE_PATH is set in options, you should set opened_path to the full path of the file/resource that was actually opened.

If the requested resource was opened successfully, you should return TRUE, otherwise you should return FALSE

void stream_close ( void )

This method is called when the stream is closed, using fclose(). You must release any resources that were locked or allocated by the stream.

string stream_read ( int count)

This method is called in response to fread() and fgets() calls on the stream. You must return up-to count bytes of data from the current read/write position as a string. If there are less than count bytes available, return as many as are available. If no more data is available, return either FALSE or an empty string. You must also update the read/write position of the stream by the number of bytes that were successfully read.

int stream_write ( string data)

This method is called in response to fwrite() calls on the stream. You should store data into the underlying storage used by your stream. If there is not enough room, try to store as many bytes as possible. You should return the number of bytes that were successfully stored in the stream, or 0 if none could be stored. You must also update the read/write position of the stream by the number of bytes that were successfully written.

boolean stream_eof ( void )

This method is called in response to feof() calls on the stream. You should return TRUE if the read/write position is at the end of the stream and if no more data is available to be read, or FALSE otherwise.

int stream_tell ( void )

This method is called in response to ftell() calls on the stream. You should return the current read/write position of the stream.

boolean stream_seek ( int offset, int whence)

This method is called in response to fseek() calls on the stream. You should update the read/write position of the stream according to offset and whence. See fseek() for more information about these parameters. Return TRUE if the position was updated, FALSE otherwise.

boolean stream_flush ( void )

This method is called in response to fflush() calls on the stream. If you have cached data in your stream but not yet stored it into the underlying storage, you should do so now. Return TRUE if the cached data was successfully stored (or if there was no data to store), or FALSE if the data could not be stored.

The example below implements a var:// protocol handler that allows read/write access to a named global variable using standard filesystem stream functions such as fread(). The var:// protocol implemented below, given the url "var://foo" will read/write data to/from $GLOBALS["foo"].
Example 1. A Stream for reading/writing global variables
class VariableStream { var $position; var $varname; function stream_open($path, $mode, $options, &$opened_path) { $url = parse_url($path); $this->varname = $url["host"]; $this->position = 0; return true; } function stream_read($count) { $ret = substr($GLOBALS[$this->varname], $this->position, $count); $this->position += strlen($ret); return $ret; } function stream_write($data) { $left = substr($GLOBALS[$this->varname], 0, $this->position); $right = substr($GLOBALS[$this->varname], $this->position + strlen($data)); $GLOBALS[$this->varname] = $left . $data . $right; $this->position += strlen($data); return strlen($data); } function stream_tell() { return $this->position; } function stream_eof() { return $this->position >= strlen($GLOBALS[$this->varname]); } function stream_seek($offset, $whence) { switch($whence) { case SEEK_SET: if ($offset < strlen($GLOBALS[$this->varname]) && $offset >= 0) { $this->position = $offset; return true; } else { return false; } break; case SEEK_CUR: if ($offset >= 0) { $this->position += $offset; return true; } else { return false; } break; case SEEK_END: if (strlen($GLOBALS[$this->varname]) + $offset >= 0) { $this->position = strlen($GLOBALS[$this->varname]) + $offset; return true; } else { return false; } break; default: return false; } } } stream_register_wrapper("var", "VariableStream") or die("Failed to register protocol"); $myvar = ""; $fp = fopen("var://myvar", "r+"); fwrite($fp, "line1\n"); fwrite($fp, "line2\n"); fwrite($fp, "line3\n"); rewind($fp); while(!feof($fp)) { echo fgets($fp) } fclose($fp); var_dump($myvar);

stream_set_blocking

(no version information, might be only in CVS)

stream_set_blocking -- Set blocking/non-blocking mode on a stream

Description

bool stream_set_blocking ( resource stream, int mode)

If mode is FALSE, the given stream will be switched to non-blocking mode, and if TRUE, it will be switched to blocking mode. This affects calls like fgets() and fread() that read from the stream. In non-blocking mode an fgets() call will always return right away while in blocking mode it will wait for data to become available on the stream.

This function was previously called as set_socket_blocking() and later socket_set_blocking() but this usage is deprecated.

Note: Prior to PHP 4.3, this function only worked on socket based streams. Since PHP 4.3, this function works for any stream that supports non-blocking mode (currently, regular files and socket streams).

stream_set_timeout

(no version information, might be only in CVS)

stream_set_timeout -- Set timeout period on a stream

Description

bool stream_set_timeout ( resource stream, int seconds, int microseconds)

Sets the timeout value on stream, expressed in the sum of seconds and microseconds.
Example 1. stream_set_timeout() Example
<?php $fp = fsockopen("www.example.com", 80); if(!$fp) { echo "Unable to open\n"; } else { fputs($fp, "GET / HTTP/1.0\n\n"); $start = time(); socket_set_timeout($fp, 2); $res = fread($fp, 2000); var_dump(stream_get_meta_data($fp)); fclose($fp); print $res; } ?>

Note: As of PHP 4.3, this function can (potentially) work on any kind of stream. In PHP 4.3, socket based streams are still the only kind supported in the PHP core, although streams from other extensions may support this function.

This function was previously called as set_socket_timeout() and later socket_set_timeout() but this usage is deprecated.

See also: fsockopen() and fopen().

stream_set_write_buffer

(no version information, might be only in CVS)

stream_set_write_buffer -- Sets file buffering on the given stream

Description

int stream_set_write_buffer ( resource stream, int buffer)

Output using fwrite() is normally buffered at 8K. This means that if there are two processes wanting to write to the same output stream (a file), each is paused after 8K of data to allow the other to write. stream_set_write_buffer() sets the buffering for write operations on the given filepointer stream to buffer bytes. If buffer is 0 then write operations are unbuffered. This ensures that all writes with fwrite() are completed before other processes are allowed to write to that output stream.

The function returns 0 on success, or EOF if the request cannot be honored.

The following example demonstrates how to use stream_set_write_buffer() to create an unbuffered stream.
Example 1. stream_set_write_buffer() example
$fp = fopen($file, "w"); if ($fp) { stream_set_write_buffer($fp, 0); fputs($fp, $output); fclose($fp); }

symlink

(PHP 3, PHP 4 )

symlink -- Creates a symbolic link

Description

int symlink ( string target, string link)

symlink() creates a symbolic link from the existing target with the specified name link.

See also link() to create hard links, and readlink() along with linkinfo().

tempnam

(PHP 3, PHP 4 )

tempnam -- Create file with unique file name

Description

string tempnam ( string dir, string prefix)

Creates a file with a unique filename in the specified directory. If the directory does not exist, tempnam() may generate a file in the system's temporary directory, and return the name of that.

Prior to PHP 4.0.6, the behaviour of the tempnam() function was system dependent. On Windows the TMP environment variable will override the dir parameter, on Linux the TMPDIR environment variable has precedence, while SVR4 will always use your dir parameter if the directory it points to exists. Consult your system documentation on the tempnam(3) function if in doubt.

Returns the new temporary filename, or the FALSE string on failure.
Example 1. tempnam() example
$tmpfname = tempnam ("/tmp", "FOO"); $fp = fopen($tmpfname, "w"); fwrite($fp, "writing to tempfile"); fclose($fp); // do here something unlink($tmpfname);

Note: This function's behavior changed in 4.0.3. The temporary file is also created to avoid a race condition where the file might appear in the filesystem between the time the string was generated and before the the script gets around to creating the file. Note, that you need to remove the file in case you need it no more, it is not done automatically.

unlink

(PHP 3, PHP 4 )

unlink -- Deletes a file

Description

int unlink ( string filename)

Deletes filename. Similar to the Unix C unlink() function.

Returns TRUE on success or FALSE on failure.

See also rmdir() for removing directories.

XXXI. Forms Data Format functions

Introduction

Forms Data Format (FDF) is a format for handling forms within PDF documents. You should read the documentation at http://partners.adobe.com/asn/developer/acrosdk/forms.html for more information on what FDF is and how it is used in general.

The general idea of FDF is similar to HTML forms. The difference is basically the format how data is transmitted to the server when the submit button is pressed (this is actually the Form Data Format) and the format of the form itself (which is the Portable Document Format, PDF). Processing the FDF data is one of the features provided by the fdf functions. But there is more. One may as well take an existing PDF form and populated the input fields with data without modifying the form itself. In such a case one would create a FDF document (fdf_create()) set the values of each input field (fdf_set_value()) and associate it with a PDF form (fdf_set_file()). Finally it has to be sent to the browser with MimeType application/vnd.fdf. The Acrobat reader plugin of your browser recognizes the MimeType, reads the associated PDF form and fills in the data from the FDF document.

If you look at an FDF-document with a text editor you will find a catalogue object with the name FDF. Such an object may contain a number of entries like Fields, F, Status etc.. The most commonly used entries are Fields which points to a list of input fields, and F which contains the filename of the PDF-document this data belongs to. Those entries are referred to in the FDF documentation as /F-Key or /Status-Key. Modifying this entries is done by functions like fdf_set_file() and fdf_set_status(). Fields are modified with fdf_set_value(), fdf_set_opt() etc..

Requirements

You need the FDF toolkit SDK available from http://partners.adobe.com/asn/developer/acrosdk/forms.html. As of PHP 4.3 you need at least SDK version 5.0. The FDF toolkit library is available in binary form only, platforms supported by Adobe are Win32, Linux, Solaris and AIX.

Installation

You must compile PHP with --with-fdftk[=DIR].

Note: If you run into problems configuring PHP with fdftk support, check whether the header file fdftk.h and the library libfdftk.so are at the right place. The configure script supports both the directory structure of the FDF SDK distribution and the usual DIR/include / DIR/lib layout, so you can point it either directly to the unpacked distribution directory or put the header file and the appropriate library for your platform into e.g. /usr/local/include and /usr/local/lib and configure with --with-fdftk=/usr/local.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

fdf

Most fdf functions require a fdf resource as their first parameter. A fdf resource is a handle to an opened fdf file. fdf resources may be obtained using fdf_create(), fdf_open() and fdf_open_string().

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

FDFValue (integer)
FDFStatus (integer)
FDFFile (integer)
FDFID (integer)
FDFFf (integer)
FDFSetFf (integer)
FDFClearFf (integer)
FDFFlags (integer)
FDFSetF (integer)
FDFClrF (integer)
FDFAP (integer)
FDFAS (integer)
FDFAction (integer)
FDFAA (integer)
FDFAPRef (integer)
FDFIF (integer)
FDFEnter (integer)
FDFExit (integer)
FDFDown (integer)
FDFUp (integer)
FDFFormat (integer)
FDFValidate (integer)
FDFKeystroke (integer)
FDFCalculate (integer)
FDFNormalAP (integer)
FDFRolloverAP (integer)
FDFDownAP (integer)

Examples

The following examples shows just the evaluation of form data.
Example 1. Evaluating a FDF document
<?php // Open fdf from input string provided by the extension // The pdf form contained several input text fields with the names // volume, date, comment, publisher, preparer, and two checkboxes // show_publisher and show_preparer. $fdf = fdf_open_string($HTTP_FDF_DATA); $volume = fdf_get_value($fdf, "volume"); echo "The volume field has the value '<B>$volume</B>'<BR>"; $date = fdf_get_value($fdf, "date"); echo "The date field has the value '<B>$date</B>'<BR>"; $comment = fdf_get_value($fdf, "comment"); echo "The comment field has the value '<B>$comment</B>'<BR>"; if(fdf_get_value($fdf, "show_publisher") == "On") { $publisher = fdf_get_value($fdf, "publisher"); echo "The publisher field has the value '<B>$publisher</B>'<BR>"; } else echo "Publisher shall not be shown.<BR>"; if(fdf_get_value($fdf, "show_preparer") == "On") { $preparer = fdf_get_value($fdf, "preparer"); echo "The preparer field has the value '<B>$preparer</B>'<BR>"; } else echo "Preparer shall not be shown.<BR>"; fdf_close($fdf); ?>

Table of Contents
fdf_add_doc_javascript -- Adds javascript code to the FDF document
fdf_add_template -- Adds a template into the FDF document
fdf_close -- Close an FDF document
fdf_create -- Create a new FDF document
fdf_errno -- Return error code for last fdf operation
fdf_error -- Return error description for fdf error code
fdf_get_ap -- Get the appearance of a field
fdf_get_attachment -- Extracts uploaded file embedded in the FDF
fdf_get_encoding -- Get the value of the /Encoding key
fdf_get_file -- Get the value of the /F key
fdf_get_status -- Get the value of the /STATUS key
fdf_get_value -- Get the value of a field
fdf_get_version -- Gets version number for FDF api or file
fdf_header -- Sets FDF-specific output headers
fdf_next_field_name -- Get the next field name
fdf_open_string -- Read a FDF document from a string
fdf_open -- Open a FDF document
fdf_save_string -- Returns the FDF document as a string
fdf_save -- Save a FDF document
fdf_set_ap -- Set the appearance of a field
fdf_set_encoding -- Sets FDF character encoding
fdf_set_file -- Set PDF document to display FDF data in
fdf_set_flags -- Sets a flag of a field
fdf_set_javascript_action -- Sets an javascript action of a field
fdf_set_opt -- Sets an option of a field
fdf_set_status -- Set the value of the /STATUS key
fdf_set_submit_form_action -- Sets a submit form action of a field
fdf_set_target_frame -- Set target frame for form display
fdf_set_value -- Set the value of a field
fdf_set_version -- Sets version number for a FDF file

(PHP 3>= 3.0.6, PHP 4 )

fdf_create -- Create a new FDF document

Description

resource fdf_create ( void)

array fdf_get_attachment ( resource fdf_document, string fieldname, string savepath)

Extracts a file uploaded by means of the "file selection" field fieldname and stores it under savepath. savepath may be the name of a plain file or an existing directory in which the file is to be created under its original name. Any existing file under the same name will be overwritten.

Note: There seems to be no other way to find out the original filename but to store the file using a directory as savepath and check for the basename it was stored under.

The returned array contains the following fields:

path - path were the file got stored
size - size of the stored file in bytes
type - mimetype if given in the FDF

The fdf_get_value() function returns the value for the requested fieldname.

Elements of an array field can be retrieved by passing the optional which, starting at zero. For non-array fields the optional parameter which will be ignored.

Note: Array support and optional which parameter were added in PHP 4.3.

fdf_get_version

(no version information, might be only in CVS)

fdf_get_version -- Gets version number for FDF api or file

Description

string fdf_get_version ( [resource fdf_document])

This function will return the fdf version for the given fdf_document, or the toolkit api version number if no parameter is given.

For the current FDF toolkit 5.0 the api version number is '5.0' and the document version number is either '1.2', '1.3' or '1.4'.

fdf_header

(no version information, might be only in CVS)

string fdf_save_string ( resource fdf_document)

The fdf_save_string() function returns the FDF document as a string.

Example 1. Retrieving FDF as a string
<?php $fdf = fdf_create(); fdf_set_value($fdf, "foo", "bar"); $str = fdf_save_string($fdf); fdf_close($fdf); echo $str; ?>
will output something like
%FDF-1.2 %âãÏÓ 1 0 obj << /FDF << /Fields 2 0 R >> >> endobj 2 0 obj [ << /T (foo)/V (bar)>> ] endobj trailer << /Root 1 0 R >> %%EOF

fdf_save

bool fdf_target_frame ( resource fdf_document, string frame_name)

Sets the target frame to display a result PDF defined with fdf_save_file() in.

fdf_set_value

(PHP 3>= 3.0.6, PHP 4 )

fdf_set_value -- Set the value of a field

Description

bool fdf_set_value ( resource fdf_document, string fieldname, mixed value [, int isName])

The fdf_set_value() function sets the value for a field named fieldname. The value will be stored as a string unless it is an array. In this case all array elements will be stored as a value array.

Note: In older versions of the fdf toolkit last parameter determined if the field value was to be converted to a PDF Name (isName = 1) or set to a PDF String (isName = 0). The value is no longer used in the current toolkit version 5.0. For compatibility reasons it is still supported as an optional parameter beginning with PHP 4.3, but ignored internaly.
Support for value arrays was added in PHP 4.3.

See also fdf_get_value() and fdf_remove_item().

fdf_set_version

(no version information, might be only in CVS)

fdf_set_version -- Sets version number for a FDF file

Description

string fdf_set_version ( resource fdf_document, string version)

This function will set the fdf version for the given fdf_document. Some features supported by this extension are only available in newer fdf versions. For the current FDF toolkit 5.0 version may be either '1.2', '1.3' or '1.4'.

XXXII. FriBiDi functions

Introduction

Requirements

Installation

Runtime Configuration

Resource Types

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

FRIBIDI_CHARSET_UTF8 (integer)
FRIBIDI_CHARSET_8859_6 (integer)
FRIBIDI_CHARSET_8859_8 (integer)
FRIBIDI_CHARSET_CP1255 (integer)
FRIBIDI_CHARSET_CP1256 (integer)
FRIBIDI_CHARSET_ISIRI_3342 (integer)

Table of Contents
fribidi_log2vis -- Convert a logical string to a visual one

fribidi_log2vis

(PHP 4 >= 4.0.4)

fribidi_log2vis -- Convert a logical string to a visual one

Description

string fribidi_log2vis ( string str, string direction, int charset)

Warning

This function is currently not documented; only the argument list is available.

XXXIII. FTP functions

Introduction

The functions in this extension implement client access to file servers speaking the File Transfer Protocol (FTP) as defined in http://www.faqs.org/rfcs/rfc959.html.

Requirements

No external libraries are needed to build this extension.

Installation

In order to use FTP functions with your PHP configuration, you should add the --enable-ftp option when installing PHP 4 or --with-ftp when using PHP 3.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension uses one resource type, which is the link identifier of the FTP connection.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

FTP_ASCII (integer)
FTP_TEXT (integer)
FTP_BINARY (integer)
FTP_IMAGE (integer)
FTP_TIMEOUT_SEC (integer): See ftp_set_option() for information.

The following constants were introduced in PHP 4.3.0.

FTP_AUTOSEEK (integer): See ftp_set_option() for information.
FTP_AUTORESUME (integer): Automatically determine resume position and start position for GET and PUT requests (only works if FTP_AUTOSEEK is enabled)
FTP_FAILED (integer): Asynchronous transfer has failed
FTP_FINISHED (integer): Asynchronous transfer has finished
FTP_MOREDATA (integer): Asynchronous transfer is still active

Examples

Example 1. FTP example
<?php // set up basic connection $conn_id = ftp_connect($ftp_server); // login with username and password $login_result = ftp_login($conn_id, $ftp_user_name, $ftp_user_pass); // check connection if ((!$conn_id) || (!$login_result)) { echo "FTP connection has failed!"; echo "Attempted to connect to $ftp_server for user $ftp_user_name"; die; } else { echo "Connected to $ftp_server, for user $ftp_user_name"; } // upload the file $upload = ftp_put($conn_id, $destination_file, $source_file, FTP_BINARY); // check upload status if (!$upload) { echo "FTP upload has failed!"; } else { echo "Uploaded $source_file to $ftp_server as $destination_file"; } // close the FTP stream ftp_close($conn_id); ?>

Table of Contents
ftp_cdup -- Changes to the parent directory
ftp_chdir -- Changes directories on a FTP server
ftp_close -- Closes an FTP connection
ftp_connect -- Opens an FTP connection
ftp_delete -- Deletes a file on the FTP server
ftp_exec -- Requests execution of a program on the FTP server
ftp_fget -- Downloads a file from the FTP server and saves to an open file
ftp_fput -- Uploads from an open file to the FTP server
ftp_get_option -- Retrieves various runtime behaviours of the current FTP stream
ftp_get -- Downloads a file from the FTP server
ftp_login -- Logs in to an FTP connection
ftp_mdtm -- Returns the last modified time of the given file
ftp_mkdir -- Creates a directory
ftp_nb_continue -- Continues retrieving/sending a file (non-blocking)
ftp_nb_fget -- Retrieves a file from the FTP server and writes it to an open file (non-blocking)
ftp_nb_fput -- Stores a file from an open file to the FTP server (non-blocking)
ftp_nb_get -- Retrieves a file from the FTP server and writes it to a local file (non-blocking)
ftp_nb_put -- Stores a file on the FTP server (non-blocking)
ftp_nlist -- Returns a list of files in the given directory
ftp_pasv -- Turns passive mode on or off
ftp_put -- Uploads a file to the FTP server
ftp_pwd -- Returns the current directory name
ftp_quit -- Closes an FTP connection
ftp_rawlist -- Returns a detailed list of files in the given directory
ftp_rename -- Renames a file on the FTP server
ftp_rmdir -- Removes a directory
ftp_set_option -- Set miscellaneous runtime FTP options
ftp_site -- Sends a SITE command to the server
ftp_size -- Returns the size of the given file
ftp_systype -- Returns the system type identifier of the remote FTP server

The timeout parameter specifies the timeout for all subsequent network operations. If omitted, the default value is 90 seconds. The timeout can be changed and queried at any time with ftp_set_option() and ftp_get_option().

Note: This parameter is available beginning with PHP 4.2.0.

ftp_delete

(PHP 3>= 3.0.13, PHP 4 )

ftp_delete -- Deletes a file on the FTP server

Description

bool ftp_delete ( resource ftp_stream, string path)

ftp_delete() deletes the file specified by path from the FTP server.

Returns TRUE on success or FALSE on error.

ftp_exec

(PHP 4 >= 4.0.3)

ftp_exec -- Requests execution of a program on the FTP server

Description

bool ftp_exec ( resource ftp_stream, string command)

Sends a SITE EXEC command request to the FTP server. Returns the output of the command if successful; otherwise returns FALSE.

ftp_fget

(PHP 3>= 3.0.13, PHP 4 )

ftp_fget -- Downloads a file from the FTP server and saves to an open file

Description

bool ftp_fget ( resource ftp_stream, resource fp, string remote_file, int mode [, int resumepos])

ftp_fget() retrieves remote_file from the FTP server, and writes it to the given file pointer, fp. The transfer mode specified must be either FTP_ASCII or FTP_BINARY.

Note: The resumepos parameter was added in PHP 4.3.0.

Returns TRUE on success or FALSE on error.

ftp_fput

(PHP 3>= 3.0.13, PHP 4 )

ftp_fput -- Uploads from an open file to the FTP server

Description

bool ftp_fput ( resource ftp_stream, string remote_file, resource fp, int mode [, int startpos])

ftp_fput() uploads the data from the file pointer fp until the end of the file is reached. The results are stored in remote_file on the FTP server. The transfer mode specified must be either FTP_ASCII or FTP_BINARY.

Note: The startpos parameter was added in PHP 4.3.0.

Returns TRUE on success or FALSE on error.

ftp_get_option

(PHP 4 >= 4.2.0)

ftp_get_option -- Retrieves various runtime behaviours of the current FTP stream

Description

mixed ftp_get_option ( resource ftp_stream, int option)

Note: This function is only available in CVS.

Returns the value on success or FALSE if the given option is not supported. In the latter case, a warning message is also thrown.

This function returns the value for the requested option from the specified ftp_stream. Currently, the following options are supported:

Table 1. Supported runtime FTP options

FTP_TIMEOUT_SEC

Returns the current timeout used for network related operations.

Example 1. ftp_get_option() example
// Get the timeout of the given FTP stream $timeout = ftp_get_option($conn_id, FTP_TIMEOUT_SEC);

ftp_get

(PHP 3>= 3.0.13, PHP 4 )

ftp_get -- Downloads a file from the FTP server

Description

bool ftp_get ( resource ftp_stream, string local_file, string remote_file, int mode [, int resumepos])

ftp_get() retrieves remote_file from the FTP server, and saves it to local_file locally. The transfer mode specified must be either FTP_ASCII or FTP_BINARY.

Note: The resumepos parameter was added in PHP 4.3.0.

Returns TRUE on success or FALSE on error.

See also ftp_fget() and ftp_async_get().

ftp_login

(PHP 3>= 3.0.13, PHP 4 )

ftp_login -- Logs in to an FTP connection

Description

bool ftp_login ( resource ftp_stream, string username, string password)

Logs in to the given FTP stream.

Returns TRUE on success or FALSE on error.

ftp_mdtm

(PHP 3>= 3.0.13, PHP 4 )

ftp_mdtm -- Returns the last modified time of the given file

Description

int ftp_mdtm ( resource ftp_stream, string remote_file)

ftp_mdtm() checks the last modified time for a file, and returns it as a UNIX timestamp. If an error occurs, or the file does not exist, -1 is returned.

Returns a UNIX timestamp on success, or -1 on error.

Note: Not all servers support this feature!

Note: ftp_mdtm() does not work with directories.

Example 1. ftp_nb_get() example
// Initate the download $ret = ftp_nb_get($my_connection, "test", "README", FTP_BINARY); while ($ret == FTP_MOREDATA) { // Do whatever you want echo "."; // Continue downloading... $ret = ftp_nb_continue ($my_connection); } if ($ret != FTP_FINISHED) { echo "There was an error downloading the file..."; exit(1); }

Example 2. Resuming a download with ftp_nb_get()
// Initate $ret = ftp_nb_get ($my_connection, "test", "README", FTP_BINARY, filesize("test")); // OR: $ret = ftp_nb_get ($my_connection, "test", "README", // FTP_BINARY, FTP_AUTORESUME); while ($ret == FTP_MOREDATA) { // Do whatever you want echo "."; // Continue downloading... $ret = ftp_nb_continue ($my_connection); } if ($ret != FTP_FINISHED) { echo "There was an error downloading the file..."; exit(1); }

Example 3. Resuming a download at position 100 to a new file with ftp_nb_get()
// Disable Autoseek ftp_set_option ($my_connection, FTP_AUTOSEEK, FALSE); // Initiate $ret = ftp_nb_get ($my_connection, "newfile", "README", FTP_BINARY, 100); while ($ret == FTP_MOREDATA) { ... // Continue downloading... $ret = ftp_nb_continue ($my_connection); }

In the example above, "newfile" is 100 bytes smaller than "README" on the FTP server because we started reading at offset 100. If we have not have disabled FTP_AUTOSEEK, the first 100 bytes of newfile will be '\0'.

ftp_nb_put

(no version information, might be only in CVS)

ftp_nb_put -- Stores a file on the FTP server (non-blocking)

Description

bool ftp_nb_put ( resource ftp_stream, string remote_file, string local_file, int mode [, int startpos])

ftp_nb_put() stores local_file on the FTP server, as remote_file. The transfer mode specified must be either FTP_ASCII or FTP_BINARY. The difference between this function and the ftp_put() is that this function uploads the file asynchronously, so your program can perform other operations while the file is being downloaded.

Returns TRUE on success or FALSE on error.

Example 1. ftp_nb_put() example
// Initiate the Upload $ret = ftp_nb_put($my_connection, "test.remote", "test.local", FTP_BINARY); while ($ret == FTP_MOREDATA) { // Do whatever you want echo "."; // Continue uploading... $ret = ftp_nb_continue ($my_connection); } if ($ret != FTP_FINISHED) { echo "There was an error uploading the file..."; exit(1); }

Example 2. Resuming an upload with ftp_nb_put()
// Initiate $ret = ftp_nb_put ($my_connection, "test.remote", "test.local", FTP_BINARY, ftp_size("test.remote")); // OR: $ret = ftp_nb_put ($my_connection, "test.remote", "test.local", // FTP_BINARY, FTP_AUTORESUME); while ($ret == FTP_MOREDATA) { // Do whatever you want echo "."; // Continue uploading... $ret = ftp_nb_continue ($my_connection); } if ($ret != FTP_FINISHED) { echo "There was an error uploading the file..."; exit(1); }

ftp_nlist

(PHP 3>= 3.0.13, PHP 4 )

ftp_nlist -- Returns a list of files in the given directory

Description

array ftp_nlist ( resource ftp_stream, string directory)

Returns an array of filenames from the specified directory on success or FALSE on error.

ftp_pasv

(PHP 3>= 3.0.13, PHP 4 )

ftp_pasv -- Turns passive mode on or off

Description

bool ftp_set_option ( resource ftp_stream, int option, mixed value)

Note: This function is only available in CVS.

Returns TRUE if the option could be set; FALSE if not. A warning message will be thrown if the option is not supported or the passed value doesn't match the expected value for the given option.

This function controls various runtime options for the specified FTP stream. The value parameter depends on which option parameter is chosen to be altered. Currently, the following options are supported:

Table 1. Supported runtime FTP options

FTP_TIMEOUT_SEC	Changes the timeout in seconds used for all network related functions. `value` must be an integer that is greater than 0. The default timeout is 90 seconds.
FTP_AUTOSEEK	When enabled, GET or PUT requests with a `resumepos` or `startpos` parameter will first seek to the requested position within the file. This is enabled by default.

XXXIV. Function Handling functions

Introduction

These functions all handle various operations involved in working with functions.

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Predefined Constants

This extension has no constants defined.

Table of Contents
call_user_func_array -- Call a user function given with an array of parameters
call_user_func -- Call a user function given by the first parameter
create_function -- Create an anonymous (lambda-style) function
func_get_arg -- Return an item from the argument list
func_get_args -- Returns an array comprising a function's argument list
func_num_args -- Returns the number of arguments passed to the function
function_exists -- Return TRUE if the given function has been defined
get_defined_functions -- Returns an array of all defined functions
register_shutdown_function -- Register a function for execution on shutdown
register_tick_function -- Register a function for execution on each tick
unregister_tick_function -- De-register a function for execution on each tick

call_user_func_array

(PHP 4 >= 4.0.4)

call_user_func_array -- Call a user function given with an array of parameters

Description

mixed call_user_func_array ( string function_name [, array paramarr])

Call a user defined function given by function_name, with the parameters in paramarr. For example:

function debug($var, $val)
    echo "***DEBUGGING\nVARIABLE: $var\nVALUE:";
    if (is_array($val) || is_object($val) || is_resource($val))
        print_r($val);
    else
        echo "\n$val\n";
    echo "***\n";
}

$c = mysql_connect();
$host = $_SERVER["SERVER_NAME"];

call_user_func_array ('debug', array("host", $host));
call_user_func_array ('debug', array("c", $c));
call_user_func_array ('debug', array("_POST", $_POST));

Note: This function was added to the CVS code after release of PHP 4.0.4pl1

call_user_func

(PHP 3>= 3.0.3, PHP 4 )

call_user_func -- Call a user function given by the first parameter

Description

mixed call_user_func ( string function_name [, mixed parameter [, mixed ...]])

Call a user defined function given by the function_name parameter. Take the following:

function barber ($type) {
    print "You wanted a $type haircut, no problem";
}
call_user_func ('barber', "mushroom");
call_user_func ('barber', "shave");

create_function

(PHP 4 >= 4.0.1)

create_function -- Create an anonymous (lambda-style) function

Description

string create_function ( string args, string code)

Creates an anonymous function from the parameters passed, and returns a unique name for it. Usually the args will be passed as a single quote delimited string, and this is also recommended for the code. The reason for using single quoted strings, is to protect the variable names from parsing, otherwise, if you use double quotes there will be a need to escape the variable names, e.g. \$avar.

You can use this function, to (for example) create a function from information gathered at run time:
Example 1. Creating an anonymous function with create_function()
$newfunc = create_function('$a,$b','return "ln($a) + ln($b) = ".log($a * $b);'); echo "New anonymous function: $newfunc\n"; echo $newfunc(2,M_E)."\n"; // outputs // New anonymous function: lambda_1 // ln(2) + ln(2.718281828459) = 1.6931471805599
Or, perhaps to have general handler function that can apply a set of operations to a list of parameters:
Example 2. Making a general processing function with create_function()
function process($var1, $var2, $farr) { for ($f=0; $f < count($farr); $f++) echo $farr[$f]($var1,$var2)."\n"; } // create a bunch of math functions $f1 = 'if ($a >=0) {return "b*a^2 = ".$b*sqrt($a);} else {return false;}'; $f2 = "return \"min(b^2+a, a^2,b) = \".min(\$a*\$a+\$b,\$b*\$b+\$a);"; $f3 = 'if ($a > 0 && $b != 0) {return "ln(a)/b = ".log($a)/$b; } else { return false; }'; $farr = array( create_function('$x,$y', 'return "some trig: ".(sin($x) + $x*cos($y));'), create_function('$x,$y', 'return "a hypotenuse: ".sqrt($x*$x + $y*$y);'), create_function('$a,$b', $f1), create_function('$a,$b', $f2), create_function('$a,$b', $f3) ); echo "\nUsing the first array of anonymous functions\n"; echo "parameters: 2.3445, M_PI\n"; process(2.3445, M_PI, $farr); // now make a bunch of string processing functions $garr = array( create_function('$b,$a','if (strncmp($a,$b,3) == 0) return "** \"$a\" '. 'and \"$b\"\n** Look the same to me! (looking at the first 3 chars)";'), create_function('$a,$b','; return "CRCs: ".crc32($a)." , ".crc32(b);'), create_function('$a,$b','; return "similar(a,b) = ".similar_text($a,$b,&$p)."($p%)";') ); echo "\nUsing the second array of anonymous functions\n"; process("Twas brilling and the slithy toves", "Twas the night", $garr);
and when you run the code above, the output will be:

Using the first array of anonymous functions
parameters: 2.3445, M_PI
some trig: -1.6291725057799
a hypotenuse: 3.9199852871011
b*a^2 = 4.8103313314525
min(b^2+a, a^2,b) = 8.6382729035898
ln(a/b) = 0.27122299212594

Using the second array of anonymous functions
** "Twas the night" and "Twas brilling and the slithy toves"
** Look the same to me! (looking at the first 3 chars)
CRCs: -725381282 , 1908338681
similar(a,b) = 11(45.833333333333%)

But perhaps the most common use for of lambda-style (anonymous) functions is to create callback functions, for example when using array_walk() or usort()

Example 3. Using anonymous functions as callback functions

$av = array("the ","a ","that ","this ");
array_walk($av, create_function('&$v,$k','$v = $v."mango";'));
print_r($av);  // for PHP 3 use var_dump()
// outputs:
// Array
// (
//   [0] => the mango
//   [1] => a mango
//   [2] => that mango
//   [3] => this mango
// )

// an array of strings ordered from shorter to longer
$sv = array("small","larger","a big string","it is a string thing");
print_r($sv);
// outputs:
// Array
// (
//   [0] => small
//   [1] => larger
//   [2] => a big string
//   [3] => it is a string thing
// )

// sort it from longer to shorter
usort($sv, create_function('$a,$b','return strlen($b) - strlen($a);'));
print_r($sv);
// outputs:
// Array
// (
//   [0] => it is a string thing
//   [1] => a big string
//   [2] => larger
//   [3] => small
// )

func_get_arg

(PHP 4 )

func_get_arg -- Return an item from the argument list

Description

mixed func_get_arg ( int arg_num)

Returns the argument which is at the arg_num'th offset into a user-defined function's argument list. Function arguments are counted starting from zero. func_get_arg() will generate a warning if called from outside of a function definition.

If arg_num is greater than the number of arguments actually passed, a warning will be generated and func_get_arg() will return FALSE.

<?php
function foo() {
     $numargs = func_num_args();
     echo "Number of arguments: $numargs<br>\n";
     if ($numargs >= 2) {
     echo "Second argument is: " . func_get_arg (1) . "<br>\n";
     }
} 

foo (1, 2, 3);
?>

func_get_arg() may be used in conjunction with func_num_args() and func_get_args() to allow user-defined functions to accept variable-length argument lists.

Note: This function was added in PHP 4.

func_get_args

(PHP 4 )

func_get_args -- Returns an array comprising a function's argument list

Description

array func_get_args ( void)

Returns an array in which each element is the corresponding member of the current user-defined function's argument list. func_get_args() will generate a warning if called from outside of a function definition.

<?php
function foo() {
    $numargs = func_num_args();
    echo "Number of arguments: $numargs<br>\n";
    if ($numargs >= 2) {
    echo "Second argument is: " . func_get_arg (1) . "<br>\n";
    }
    $arg_list = func_get_args();
    for ($i = 0; $i < $numargs; $i++) {
    echo "Argument $i is: " . $arg_list[$i] . "<br>\n";
    }
} 

foo (1, 2, 3);
?>

func_get_args() may be used in conjunction with func_num_args() and func_get_arg() to allow user-defined functions to accept variable-length argument lists.

Note: This function was added in PHP 4.

func_num_args

(PHP 4 )

func_num_args -- Returns the number of arguments passed to the function

Description

int func_num_args ( void)

Returns the number of arguments passed into the current user-defined function. func_num_args() will generate a warning if called from outside of a user-defined function.

<?php
function foo() {
    $numargs = func_num_args();
    echo "Number of arguments: $numargs\n";
} 

foo (1, 2, 3);    // Prints 'Number of arguments: 3'
?>

func_num_args() may be used in conjunction with func_get_arg() and func_get_args() to allow user-defined functions to accept variable-length argument lists.

function_exists

(PHP 3>= 3.0.7, PHP 4 )

function_exists -- Return TRUE if the given function has been defined

Description

bool function_exists ( string function_name)

Checks the list of defined functions, both built-in (internal) and user-defined, for function_name. Returns TRUE on success or FALSE on failure.

if (function_exists('imap_open')) {
    echo "IMAP functions are available.<br>\n";
} else {
    echo "IMAP functions are not available.<br>\n";
}

Note that a function name may exist even if the function itself is unusable due to configuration or compiling options (with the image functions being an example). Also note that function_exists() will return FALSE for constructs, such as include_once() and echo().

get_defined_functions

(PHP 4 >= 4.0.4)

get_defined_functions -- Returns an array of all defined functions

Description

array get_defined_functions ( void)

This function returns an multidimensional array containing a list of all defined functions, both built-in (internal) and user-defined. The internal functions will be accessible via $arr["internal"], and the user defined ones using $arr["user"] (see example below).

function myrow($id, $data) {
    return "<tr><th>$id</th><td>$data</td></tr>\n";
}

$arr = get_defined_functions();

print_r($arr);

Will output something along the lines of:

Array
(
    [internal] => Array
        (
            [0] => zend_version
            [1] => func_num_args
            [2] => func_get_arg
            [3] => func_get_args
            [4] => strlen
            [5] => strcmp
            [6] => strncmp
            ...
            [750] => bcscale
            [751] => bccomp
        )

    [user] => Array
        (
            [0] => myrow
        )

)

register_shutdown_function

(PHP 3>= 3.0.4, PHP 4 )

register_shutdown_function -- Register a function for execution on shutdown

Description

int register_shutdown_function ( string func)

Registers the function named by func to be executed when script processing is complete.

Multiple calls to register_shutdown_function() can be made, and each will be called in the same order as they were registered. If you call exit() within one registered shutdown function, processing will stop completely and no other registered shutdown functions will be called.

The registered shutdown functions are called after the request has been completed (including sending any output buffers), so it is not possible to send output to the browser using echo() or print(), or retrieve the contents of any output buffers using ob_get_contents().

Note: Instead of a function name, an array containing an object reference and a method name can also be supplied.

register_tick_function

(PHP 4 >= 4.0.3)

register_tick_function -- Register a function for execution on each tick

Description

void register_tick_function ( string func [, mixed arg])

Registers the function named by func to be executed when a tick is called.

unregister_tick_function

(PHP 4 >= 4.0.3)

unregister_tick_function -- De-register a function for execution on each tick

Description

void unregister_tick_function ( string func [, mixed arg])

De-registers the function named by func so it is no longer executed when a tick is called.

XXXV. Gettext

Introduction

The gettext functions implement an NLS (Native Language Support) API which can be used to internationalize your PHP applications. Please see the gettext documentation for your system for a thorough explanation of these functions or view the docs at http://www.gnu.org/manual/gettext/index.html.

Requirements

To use these functions you must download and install the GNU gettext package from http://www.gnu.org/software/gettext/gettext.html

Installation

To include GNU gettext support in your PHP build you must add the option --with-gettext[=DIR] where DIR is the gettext install directory, defaults to /usr/local.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Table of Contents
bind_textdomain_codeset -- Specify the character encoding in which the messages from the DOMAIN message catalog will be returned
bindtextdomain -- Sets the path for a domain
dcgettext -- Overrides the domain for a single lookup
dcngettext -- Plural version of dcgettext
dgettext -- Override the current domain
dngettext -- Plural version of dgettext
gettext -- Lookup a message in the current domain
ngettext -- Plural version of gettext
textdomain -- Sets the default domain

bind_textdomain_codeset

(PHP 4 >= 4.2.0)

bind_textdomain_codeset -- Specify the character encoding in which the messages from the DOMAIN message catalog will be returned

Description

string bind_textdomain_codeset ( string domain, string codeset)

string dcngettext ( string domain, string msgid1, string msgid2, int n, int category)

Warning

This function is currently not documented; only the argument list is available.

dgettext

(PHP 3>= 3.0.7, PHP 4 )

dgettext -- Override the current domain

Description

string dgettext ( string domain, string message)

The dgettext() function allows you to override the current domain for a single message lookup.

dngettext

(PHP 4 >= 4.2.0)

dngettext -- Plural version of dgettext

Description

string dngettext ( string domain, string msgid1, string msgid2, int n)

Warning

This function is currently not documented; only the argument list is available.

gettext

(PHP 3>= 3.0.7, PHP 4 )

gettext -- Lookup a message in the current domain

Description

string gettext ( string message)

This function returns a translated string if one is found in the translation table, or the submitted message if not found. You may use the underscore character '_' as an alias to this function.

Example 1. gettext()-check

<?php
// Set language to German
setlocale(LC_ALL, 'de');

// Specify location of translation tables
bindtextdomain("myPHPApp", "./locale");

// Choose domain
textdomain("myPHPApp");

// Print a test message
print gettext("Welcome to My PHP Application");

// Or use the alias _() for gettext()
print _("Have a nice day");
?>

ngettext

(PHP 4 >= 4.2.0)

ngettext -- Plural version of gettext

Description

string ngettext ( string msgid1, string msgid2, int n)

Warning

This function is currently not documented; only the argument list is available.

textdomain

(PHP 3>= 3.0.7, PHP 4 )

textdomain -- Sets the default domain

Description

string textdomain ( string text_domain)

This function sets the domain to search within when calls are made to gettext(), usually the named after an application. The previous default domain is returned. Call it with NULL as parameter to get the current setting without changing it.

XXXVI. GMP functions

Introduction

These functions allow you to work with arbitrary-length integers using the GNU MP library.

These functions have been added in PHP 4.0.4.

Note: Most GMP functions accept GMP number arguments, defined as resource below. However, most of these functions will also accept numeric and string arguments, given that it is possible to convert the latter to a number. Also, if there is a faster function that can operate on integer arguments, it would be used instead of the slower function when the supplied arguments are integers. This is done transparently, so the bottom line is that you can use integers in every function that expects GMP number. See also the gmp_init() function.

Warning

If you want to explicitly specify a large integer, specify it as a string. If you don't do that, PHP will interpret the integer-literal first, possibly resulting in loss of precision, even before GMP comes into play.

Requirements

You can download the GMP library from http://www.swox.com/gmp/. This site also has the GMP manual available.

You will need GMP version 2 or better to use these functions. Some functions may require more recent version of the GMP library.

Installation

In order to have these functions available, you must compile PHP with GMP support by using the --with-gmp option.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

GMP_ROUND_ZERO (integer)
GMP_ROUND_PLUSINF (integer)
GMP_ROUND_MINUSINF (integer)

Description

Example 1. Creating GMP number
<?php $a = gmp_init (123456); $b = gmp_init ("0xFFFFDEBACDFEDF7200"); ?>

Note: It is not necessary to call this function if you want to use integer or string in place of GMP number in GMP functions, like gmp_add(). Function arguments are automatically converted to GMP numbers, if such conversion is possible and needed, using the same rules as gmp_init().

gmp_intval

(PHP 4 >= 4.0.4)

gmp_intval -- Convert GMP number to integer

Description

bool gmp_perfect_square ( resource a)

string gmp_strval ( resource gmpnumber [, int base])

Convert GMP number to string representation in base base. The default base is 10. Allowed values for the base are from 2 to 36.

Example 1. Converting a GMP number to a string
<?php $a = gmp_init("0x41682179fbf5"); printf ("Decimal: %s, 36-based: %s", gmp_strval($a), gmp_strval($a,36)); ?>

gmp_sub

(PHP 4 >= 4.0.4)

gmp_sub -- Subtract numbers

Description

resource gmp_sub ( resource a, resource b)

Subtracts b from a and returns the result.

gmp_xor

(PHP 4 >= 4.0.4)

gmp_xor -- Logical XOR

Description

resource gmp_xor ( resource a, resource b)

Calculates logical exclusive OR (XOR) of two GMP numbers.

XXXVII. HTTP functions

Introduction

These functions let you manipulate the output sent back to the remote browser right down to the HTTP protocol level.

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Table of Contents
header -- Send a raw HTTP header
headers_sent -- Returns TRUE if headers have been sent
setcookie -- Send a cookie

header

(PHP 3, PHP 4 )

header -- Send a raw HTTP header

Description

int header ( string string [, bool replace [, int http_reponse_code]])

header() is used to send raw HTTP headers. See the HTTP/1.1 specification for more information on HTTP headers.

The optional replace parameter indicates whether the header should replace a previous similar header, or add a second header of the same type. By default it will replace, but if you pass in FALSE as the second argument you can force multiple headers of the same type. For example:

<?php
header('WWW-Authenticate: Negotiate');
header('WWW-Authenticate: NTLM', FALSE);
?>

The second optional http_response_code force the HTTP response code to the specified value. (This parameter is available in PHP 4.3.0 and higher.)

There are two special-case header calls. The first is a header that starts with the string "HTTP/" (case is not significant), which will be used to figure out the HTTP status code to send. For example, if you have configured Apache to use a PHP script to handle requests for missing files (using the ErrorDocument directive), you may want to make sure that your script generates the proper status code.

<?php
  header("HTTP/1.0 404 Not Found");
?>

Note: The HTTP status header line will always be the first sent to the client, regardless of the actual header() call beeing the first or not. The status may be overridden by calling header() with a new status line at any time unless the HTTP headers have already been sent.

Note: In PHP 3, this only works when PHP is compiled as an Apache module. You can achieve the same effect using the Status header.
<?php
header("Status: 404 Not Found");
?>

The second special case is the "Location:" header. Not only does it send this header back to the browser, but it also returns a REDIRECT (302) status code to the browser unless some 3xx status code has already been set.

<?php
header("Location: http://www.example.com/"); /* Redirect browser */
exit;                 /* Make sure that code below does 
                         not get executed when we redirect. */
?>

Note: HTTP/1.1 requires an absolute URI as argument to Location: including the scheme, hostname and absolute path, but some clients accept relative URIs. You can usually use $_SERVER['HTTP_HOST'], $_SERVER['PHP_SELF'] and dirname() to make an absolute URI from a relative one yourself:
<?php
header("Location: http://".$_SERVER['HTTP_HOST']
                      .dirname($_SERVER['PHP_SELF'])
                      ."/".$relative_url);
?>

PHP scripts often generate dynamic content that must not be cached by the client browser or any proxy caches between the server and the client browser. Many proxies and clients can be forced to disable caching with

<?php
header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");    // Date in the past
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT"); 
                                                     // always modified
header("Cache-Control: no-store, no-cache, must-revalidate");  // HTTP/1.1
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");                          // HTTP/1.0
?>

Note: You may find that your pages aren't cached even if you don't output all of the headers above. There are a number of options that users may be able to set for their browser that change its default caching behavior. By sending the headers above, you should override any settings that may otherwise cause the output of your script to be cached.
Additionally, session_cache_limiter() and the session.cache_limiter configuration setting can be used to automatically generate the correct caching-related headers when sessions are being used.

Remember that header() must be called before any actual output is sent, either by normal HTML tags, blank lines in a file, or from PHP. It is a very common error to read code with include(), or require(), functions, or another file access function, and have spaces or empty lines that are output before header() is called. The same problem exists when using a single PHP/HTML file.

<?php header ("Content-type: audio/x-pn-realaudio"); ?>
// Broken, note the blank line above

Note: In PHP 4, you can use output buffering to get around this problem, with the overhead of all of your output to the browser being buffered in the server until you send it. You can do this by calling ob_start() and ob_end_flush() in your script, or setting the output_buffering configuration directive on in your php.ini or server configuration files.

If you want the user to be prompted to save the data you are sending, such as a generated PDF file, you can use the Content-Disposition header to supply a recommended filename and force the browser to display the save dialog.

<?php
// We'll be outputting a PDF
header("Content-type: application/pdf");

// It will be called downloaded.pdf
header("Content-Disposition: attachment; filename=downloaded.pdf");

// The PDF source is in original.pdf
readfile('original.pdf');
?>

Note: There is a bug in Microsoft Internet Explorer 4.01 that prevents this from working. There is no workaround. There is also a bug in Microsoft Internet Explorer 5.5 that interferes with this, which can be resolved by upgrading to Service Pack 2 or later.

Note: If safe mode is enabled the uid of the script is added to the realm part of the WWW-Authenticate header if you set this header (used for HTTP Authentication).

See also headers_sent(), setcookie(), and the section on HTTP authentication.

headers_sent

(PHP 3>= 3.0.8, PHP 4 )

headers_sent -- Returns TRUE if headers have been sent

Description

bool headers_sent ( string &file [, int &line])

This function returns TRUE if the HTTP headers have already been sent, FALSE otherwise. You can't add any more header lines using the header() function once the header block has already been sent. Using this function you can at least prevent getting the "Duplicate headers ..." error messages.

The function will return the php source file and line number where output started in the optional file and line parameters if these are given.

Note: file and line where added for PHP 4.3.0.

See also header() for a more detailed discussion of the matters involved.

setcookie

(PHP 3, PHP 4 )

setcookie -- Send a cookie

Description

boolean setcookie ( string name [, string value [, int expire [, string path [, string domain [, int secure]]]]])

setcookie() defines a cookie to be sent along with the rest of the header information. Cookies must be sent before any other headers are sent (this is a restriction of cookies, not PHP). This requires you to place calls to this function before any <html> or <head> tags. If headers exist prior to calling this function, setcookie() will fail and return FALSE. If setcookie() successfully runs, it will return TRUE This does not mean the user accepted the cookie or not.

All the arguments except the name argument are optional. If only the name argument is present, the cookie by that name will be deleted from the remote client. You may also replace any argument with an empty string ("") in order to skip that argument. The expire and secure arguments are integers and cannot be skipped with an empty string. Use a zero (0) instead. The expire argument is a regular Unix time integer as returned by the time() or mktime() functions. The secure indicates that the cookie should only be transmitted over a secure HTTPS connection.

Once the cookies have been set, they can be accessed on the next page load with the $_COOKIE or $HTTP_COOKIE_VARS arrays. Note, autoglobals such as $_COOKIE became available in PHP 4.1.0. $HTTP_COOKIE_VARS has existed since PHP 3.

Common Pitfalls:

Cookies will not become visible until the next loading of a page that the cookie should be visible for. To test if a cookie was successfully set, check for the cookie on a next loading page before the cookie expires. Expire time is set via the expire parameter.
Cookies must be deleted with the same parameters as they were set with.
Cookies names can be set as array names and will be available to your PHP scripts as arrays but seperate cookies are stored on the users system. Consider explode() or serialize() to set one cookie with multiple names and values.

In PHP 3, multiple calls to setcookie() in the same script will be performed in reverse order. If you are trying to delete one cookie before inserting another you should put the insert before the delete. In PHP 4, multiple calls to setcookie() are performed in the order called.

Some examples follow how to send cookies:
Example 1. setcookie() send examples
setcookie ("TestCookie", $value); setcookie ("TestCookie", $value,time()+3600); /* expire in 1 hour */ setcookie ("TestCookie", $value,time()+3600, "/~rasmus/", ".utoronto.ca", 1);

When deleting a cookie you should assure that the expiration date is in the past, to trigger the removal mechanism in your browser. Examples follow how to delete cookies sent in previous example:
Example 2. setcookie() delete examples
// set the expiration date to one hour ago setcookie ("TestCookie", "", time() - 3600); setcookie ("TestCookie", "", time() - 3600, "/~rasmus/", ".utoronto.ca", 1);

Note that the value portion of the cookie will automatically be urlencoded when you send the cookie, and when it is received, it is automatically decoded and assigned to a variable by the same name as the cookie name. To see the contents of our test cookie in a script, simply use one of the following examples:

echo $TestCookie;
echo $_COOKIE["TestCookie"];

You may also set array cookies by using array notation in the cookie name. This has the effect of setting as many cookies as you have array elements, but when the cookie is received by your script, the values are all placed in an array with the cookie's name:

setcookie ("cookie[three]", "cookiethree");
setcookie ("cookie[two]", "cookietwo");
setcookie ("cookie[one]", "cookieone");
if (isset ($cookie)) {
    while (list ($name, $value) = each ($cookie)) {
        echo "$name == $value<br>\n";
    }
}

For more information on cookies, see Netscape's cookie specification at http://www.netscape.com/newsref/std/cookie_spec.html.

Microsoft Internet Explorer 4 with Service Pack 1 applied does not correctly deal with cookies that have their path parameter set.

Netscape Communicator 4.05 and Microsoft Internet Explorer 3.x appear to handle cookies incorrectly when the path and time are not set.

XXXVIII. Hyperwave functions

Introduction

Hyperwave has been developed at IICM in Graz. It started with the name Hyper-G and changed to Hyperwave when it was commercialised (in 1996).

Hyperwave is not free software. The current version, 5.5 is available at http://www.hyperwave.com/. A time limited version can be ordered for free (30 days).

Requirements

This extension needs a Hyperwave server downloadable from http://www.hyperwave.com/.

Installation

Integration with Apache

The Hyperwave extension is best used when PHP is compiled as an Apache module. In such a case the underlying Hyperwave server can be hidden from users almost completely if Apache uses its rewriting engine. The following instructions will explain this.

Since PHP with Hyperwave support built into Apache is intended to replace the native Hyperwave solution based on Wavemaster, we will assume that the Apache server will only serve as a Hyperwave web interface for these examples. This is not necessary but it simplifies the configuration. The concept is quite simple. First of all you need a PHP script which evaluates the $_ENV['PATH_INFO'] variable and treats its value as the name of a Hyperwave object. Let's call this script 'Hyperwave'. The URL http://your.hostname/Hyperwave/name_of_object would than return the Hyperwave object with the name 'name_of_object'. Depending on the type of the object the script has to react accordingly. If it is a collection, it will probably return a list of children. If it is a document it will return the mime type and the content. A slight improvement can be achieved if the Apache rewriting engine is used. From the users point of view it would be more straight forward if the URL http://your.hostname/name_of_object would return the object. The rewriting rule is quite easy:

RewriteRule ^/(.*) /usr/local/apache/htdocs/HyperWave/$1 [L]

Now every URL relates to an object in the Hyperwave server. This causes a simple to solve problem. There is no way to execute a different script, e.g. for searching, than the 'Hyperwave' script. This can be fixed with another rewriting rule like the following:

RewriteRule ^/hw/(.*) /usr/local/apache/htdocs/hw/$1 [L]

This will reserve the directory /usr/local/apache/htdocs/hw for additional scripts and other files. Just make sure this rule is evaluated before the one above. There is just a little drawback: all Hyperwave objects whose name starts with 'hw/' will be shadowed. So, make sure you don't use such names. If you need more directories, e.g. for images just add more rules or place them all in one directory. Before you put those instructions, don't forget to turn on the rewriting engine with

RewriteEngine on

You will need scripts:

to return the object itself
to allow searching
to identify yourself
to set your profile
one for each additional function like to show the object attributes, to show information about users, to show the status of the server, etc.

As an alternative to the Rewrite Engine, you can also consider using the Apache ErrorDocument directive, but be aware, that ErrorDocument redirected pages cannot receive POST data.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Hyperwave configuration options

Name	Default	Changeable
hyerwave.allow_persistent	"0"	PHP_INI_SYSTEM
hyperwave.default_port	"418"	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

HW_ATTR_LANG (integer)
HW_ATTR_NR (integer)
HW_ATTR_NONE (integer)

Todo

There are still some things to do:

The hw_InsertDocument has to be split into hw_insertobject() and hw_putdocument().
The names of several functions are not fixed, yet.
Most functions require the current connection as its first parameter. This leads to a lot of typing, which is quite often not necessary if there is just one open connection. A default connection will improve this.
Conversion form object record into object array needs to handle any multiple attribute.

Table of Contents
hw_Array2Objrec -- convert attributes from object array to object record
hw_changeobject -- Changes attributes of an object (obsolete)
hw_Children -- object ids of children
hw_ChildrenObj -- object records of children
hw_Close -- closes the Hyperwave connection
hw_Connect -- opens a connection
hw_connection_info -- Prints information about the connection to Hyperwave server
hw_Cp -- copies objects
hw_Deleteobject -- deletes object
hw_DocByAnchor -- object id object belonging to anchor
hw_DocByAnchorObj -- object record object belonging to anchor
hw_Document_Attributes -- object record of hw_document
hw_Document_BodyTag -- body tag of hw_document
hw_Document_Content -- returns content of hw_document
hw_Document_SetContent -- sets/replaces content of hw_document
hw_Document_Size -- size of hw_document
hw_dummy -- Hyperwave dummy function
hw_EditText -- retrieve text document
hw_Error -- error number
hw_ErrorMsg -- returns error message
hw_Free_Document -- frees hw_document
hw_GetAnchors -- object ids of anchors of document
hw_GetAnchorsObj -- object records of anchors of document
hw_GetAndLock -- return bject record and lock object
hw_GetChildColl -- object ids of child collections
hw_GetChildCollObj -- object records of child collections
hw_GetChildDocColl -- object ids of child documents of collection
hw_GetChildDocCollObj -- object records of child documents of collection
hw_GetObject -- object record
hw_GetObjectByQuery -- search object
hw_GetObjectByQueryColl -- search object in collection
hw_GetObjectByQueryCollObj -- search object in collection
hw_GetObjectByQueryObj -- search object
hw_GetParents -- object ids of parents
hw_GetParentsObj -- object records of parents
hw_getrellink -- Get link from source to dest relative to rootid
hw_GetRemote -- Gets a remote document
hw_GetRemoteChildren -- Gets children of remote document
hw_GetSrcByDestObj -- Returns anchors pointing at object
hw_GetText -- retrieve text document
hw_getusername -- name of currently logged in user
hw_Identify -- identifies as user
hw_InCollections -- check if object ids in collections
hw_Info -- info about connection
hw_InsColl -- insert collection
hw_InsDoc -- insert document
hw_insertanchors -- Inserts only anchors into text
hw_InsertDocument -- upload any document
hw_InsertObject -- inserts an object record
hw_mapid -- Maps global id on virtual local id
hw_Modifyobject -- modifies object record
hw_Mv -- moves objects
hw_New_Document -- create new document
hw_Objrec2Array -- convert attributes from object record to object array
hw_Output_Document -- prints hw_document
hw_pConnect -- make a persistent database connection
hw_PipeDocument -- retrieve any document
hw_Root -- root object id
hw_setlinkroot -- Set the id to which links are calculated
hw_stat -- Returns status string
hw_Unlock -- unlock object
hw_Who -- List of currently logged in users

hw_Array2Objrec

(PHP 3>= 3.0.4, PHP 4 )

hw_Array2Objrec -- convert attributes from object array to object record

Description

strin hw_array2objrec ( array object_array)

Converts an object_array into an object record. Multiple attributes like 'Title' in different languages are treated properly.

hw_changeobject

(PHP 3>= 3.0.3, PHP 4 )

hw_changeobject -- Changes attributes of an object (obsolete)

Description

void hw_changeobject ( int link, int objid, array attributes)

string hw_document_attributes ( int hw_document)

Returns the object record of the document.

For backward compatibility, hw_documentattributes() is also accepted. This is deprecated, however.

hw_Document_BodyTag

(PHP 3>= 3.0.3, PHP 4 )

hw_Document_BodyTag -- body tag of hw_document

Description

string hw_document_bodytag ( int hw_document)

int hw_document_size ( int hw_document)

Returns the size in bytes of the document.

For backward compatibility, hw_documentsize() is also accepted. This is deprecated, however.

hw_dummy

(PHP 3>= 3.0.3, PHP 4 )

hw_dummy -- Hyperwave dummy function

Description

array hw_getobject ( int connection, [int|array] objectID, string query)

Returns the object record for the object with ID objectID if the second parameter is an integer. If the second parameter is an array of integer the function will return an array of object records. In such a case the last parameter is also evaluated which is a query string.

The query string has the following syntax:

<expr> ::= "(" <expr> ")" |

"!" <expr> | /* NOT */

<expr> "||" <expr> | /* OR */

<expr> "&&" <expr> | /* AND */

<attribute> ::= /* any attribute name (Title, Author, DocumentType ...) */

<operator> ::= "=" | /* equal */

"<" | /* less than (string compare) */

array hw_getparents ( int connection, int objectID)

Returns an indexed array of object ids. Each object id belongs to a parent of the object with ID objectID.

hw_GetParentsObj

(PHP 3>= 3.0.3, PHP 4 )

hw_GetParentsObj -- object records of parents

Description

array hw_getparentsobj ( int connection, int objectID)

Returns an indexed array of object records plus an associated array with statistical information about the object records. The associated array is the last entry of the returned array. Each object record belongs to a parent of the object with ID objectID.

hw_getrellink

(PHP 3>= 3.0.3, PHP 4 )

hw_getrellink -- Get link from source to dest relative to rootid

Description

string hw_getrellink ( int link, int rootid, int sourceid, int destid)

Warning

This function is currently not documented; only the argument list is available.

hw_InsertDocument

(PHP 3>= 3.0.3, PHP 4 )

hw_InsertDocument -- upload any document

int hw_modifyobject ( int connection, int object_to_change, array remove, array add, int mode)

This command allows to remove, add, or modify individual attributes of an object record. The object is specified by the Object ID object_to_change. The first array remove is a list of attributes to remove. The second array add is a list of attributes to add. In order to modify an attribute one will have to remove the old one and add a new one. hw_modifyobject() will always remove the attributes before it adds attributes unless the value of the attribute to remove is not a string or array.

The last parameter determines if the modification is performed recursively. 1 means recurive modification. If some of the objects cannot be modified they will be skiped without notice. hw_error() may not indicate an error though some of the objects could not be modified.

The keys of both arrays are the attributes name. The value of each array element can either be an array, a string or anything else. If it is an array each attribute value is constructed by the key of each element plus a colon and the value of each element. If it is a string it is taken as the attribute value. An empty string will result in a complete removal of that attribute. If the value is neither a string nor an array but something else, e.g. an integer, no operation at all will be performed on the attribute. This is neccessary if you want to to add a completely new attribute not just a new value for an existing attribute. If the remove array contained an empty string for that attribute, the attribute would be tried to be removed which would fail since it doesn't exist. The following addition of a new value for that attribute would also fail. Setting the value for that attribute to e.g. 0 would not even try to remove it and the addition will work.

If you would like to change the attribute 'Name' with the current value 'books' into 'articles' you will have to create two arrays and call hw_modifyobject().
Example 1. modifying an attribute
// $connect is an existing connection to the Hyperwave server // $objid is the ID of the object to modify $remarr = array("Name" => "books"); $addarr = array("Name" => "articles"); $hw_modifyobject($connect, $objid, $remarr, $addarr);
In order to delete/add a name=value pair from/to the object record just pass the remove/add array and set the last/third parameter to an empty array. If the attribute is the first one with that name to add, set attribute value in the remove array to an integer.
Example 2. adding a completely new attribute
// $connect is an existing connection to the Hyperwave server // $objid is the ID of the object to modify $remarr = array("Name" => 0); $addarr = array("Name" => "articles"); $hw_modifyobject($connect, $objid, $remarr, $addarr);

Note: Multilingual attributes, e.g. 'Title', can be modified in two ways. Either by providing the attributes value in its native form 'language':'title' or by providing an array with elements for each language as described above. The above example would than be:

Example 3. modifying Title attribute

$remarr = array("Title" => "en:Books");
       $addarr = array("Title" => "en:Articles");
       $hw_modifyobject($connect, $objid, $remarr, $addarr);

Example 4. modifying Title attribute

$remarr = array("Title" => array("en" => "Books"));
       $addarr = array("Title" => array("en" => "Articles", "ge"=>"Artikel"));
       $hw_modifyobject($connect, $objid, $remarr, $addarr);

This removes the english title 'Books' and adds the english title 'Articles' and the german title 'Artikel'.

Example 5. removing attribute

$remarr = array("Title" => "");
       $addarr = array("Title" => "en:Articles");
       $hw_modifyobject($connect, $objid, $remarr, $addarr);

Note: This will remove all attributes with the name 'Title' and adds a new 'Title' attribute. This comes in handy if you want to remove attributes recursively.

Note: If you need to delete all attributes with a certain name you will have to pass an empty string as the attribute value.

Note: Only the attributes 'Title', 'Description' and 'Keyword' will properly handle the language prefix. If those attributes don't carry a language prefix, the prefix 'xx' will be assigned.

Note: The 'Name' attribute is somewhat special. In some cases it cannot be complete removed. You will get an error message 'Change of base attribute' (not clear when this happens). Therefore you will always have to add a new Name first and than remove the old one.

Note: You may not suround this function by calls to hw_getandlock() and hw_unlock(). hw_modifyobject() does this internally.

Returns TRUE if no error occurs otherwise FALSE.

hw_Mv

(PHP 3>= 3.0.3, PHP 4 )

hw_Mv -- moves objects

Description

int hw_mv ( int connection, array object id array, int source id, int destination id)

Moves the objects with object ids as specified in the second parameter from the collection with id source id to the collection with the id destination id. If the destination id is 0 the objects will be unlinked from the source collection. If this is the last instance of that object it will be deleted. If you want to delete all instances at once, use hw_deleteobject().

int hw_output_document ( int hw_document)

Prints the document without the BODY tag.

For backward compatibility, hw_outputdocument() is also accepted. This is deprecated, however.

hw_pConnect

(PHP 3>= 3.0.3, PHP 4 )

hw_pConnect -- make a persistent database connection

Description

int hw_pconnect ( string host, int port, string username, string password)

Returns a connection index on success, or FALSE if the connection could not be made. Opens a persistent connection to a Hyperwave server. Each of the arguments should be a quoted string, except for the port number. The username and password arguments are optional and can be left out. In such a case no identification with the server will be done. It is similar to identify as user anonymous. This function returns a connection index that is needed by other Hyperwave functions. You can have multiple persistent connections open at once.

hw_PipeDocument

(PHP 3>= 3.0.3, PHP 4 )

hw_PipeDocument -- retrieve any document

Description

int hw_pipedocument ( int connection, int objectID)

Returns the Hyperwave document with object ID objectID. If the document has anchors which can be inserted, they will have been inserted already. The document will be transfered via a special data connection which does not block the control connection.

See also hw_gettext() for more on link insertion, hw_free_document(), hw_document_size(), hw_document_bodytag(), and hw_output_document().

hw_Root

(PHP 3>= 3.0.3, PHP 4 )

hw_Root -- root object id

int hw_unlock ( int connection, int objectID)

Unlocks a document, so other users regain access.

hw_Who

(PHP 3>= 3.0.3, PHP 4 )

hw_Who -- List of currently logged in users

Description

int hw_who ( int connection)

Returns an array of users currently logged into the Hyperwave server. Each entry in this array is an array itself containing the elements id, name, system, onSinceDate, onSinceTime, TotalTime and self. 'self' is 1 if this entry belongs to the user who initianted the request.

XXXIX. Hyperwave API functions

Introduction

Hyperwave has been developed at IICM in Graz. It started with the name Hyper-G and changed to Hyperwave when it was commercialised (in 1996).

Hyperwave is not free software. The current version, 5.5, is available at http://www.hyperwave.com/. A time limited version can be ordered for free (30 days).

Requirements

Since 2001 there is a Hyperwave SDK available. It supports Java, JavaScript and C++. This PHP Extension is based on the C++ interface. In order to activate the hwapi support in PHP you will have to install the Hyperwave SDK first.

Installation

After installing the Hyperwave SDK, configure PHP with --with-hwapi=<dir$gt;.

Integration with Apache

The integration with Apache and possible other servers is already described in the Hyperwave module which has been the first extension to connect a Hyperwave Server.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Hyperwave API configuration options

Name	Default	Changeable
hwapi.allow_persistent	"0"	PHP_INI_SYSTEM

For further details and definition of the PHP_INI_* constants see ini_set().

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Classes

The API provided by the HW_API extension is fully object oriented. It is very similar to the C++ interface of the Hyperwave SDK. It consist of the following classes.

HW_API
HW_API_Object
HW_API_Attribute
HW_API_Error
HW_API_Content
HW_API_Reason

Some basic classes like HW_API_String, HW_API_String_Array, etc., which exist in the Hyperwave SDK have not been implemented since PHP has powerful replacements for them.

Each class has certain method, whose names are identical to its counterparts in the Hyperwave SDK. Passing arguments to this function differs from all the other PHP extensions but is close to the C++ API of the HW SDK. Instead of passing serval parameters they are all put into an associated array and passed as one paramter. The names of the keys are identical to those documented in the HW SDK. The common parameters are listed below. If other parameters are required they will be documented if needed.

objectIdentifier The name or id of an object, e.g. "rootcollection", "0x873A8768 0x00000002".
parentIdentifier The name or id of an object which is considered to be a parent.
object An instance of class HW_API_Object.
parameters An instance of class HW_API_Object.
version The version of an object.
mode An integer value determine the way an operation is executed.
attributeSelector Any array of strings, each containing a name of an attribute. This is used if you retrieve the object record and want to include certain attributes.
objectQuery A query to select certain object out of a list of objects. This is used to reduce the number of objects which was delivered by a function like hw_api->children() or hw_api->find().

Table of Contents
hw_api_attribute->key -- Returns key of the attribute
hw_api_attribute->langdepvalue -- Returns value for a given language
hw_api_attribute->value -- Returns value of the attribute
hw_api_attribute->values -- Returns all values of the attribute
hw_api_attribute -- Creates instance of class hw_api_attribute
hw_api->checkin -- Checks in an object
hw_api->checkout -- Checks out an object
hw_api->children -- Returns children of an object
hw_api_content->mimetype -- Returns mimetype
hw_api_content->read -- Read content
hw_api->content -- Returns content of an object
hw_api->copy -- Copies physically
hw_api->dbstat -- Returns statistics about database server
hw_api->dcstat -- Returns statistics about document cache server
hw_api->dstanchors -- Returns a list of all destination anchors
hw_api->dstofsrcanchors -- Returns destination of a source anchor
hw_api_error->count -- Returns number of reasons
hw_api_error->reason -- Returns reason of error
hw_api->find -- Search for objects
hw_api->ftstat -- Returns statistics about fulltext server
hwapi_hgcsp -- Returns object of class hw_api
hw_api->hwstat -- Returns statistics about Hyperwave server
hw_api->identify -- Log into Hyperwave Server
hw_api->info -- Returns information about server configuration
hw_api->insert -- Inserts a new object
hw_api->insertanchor -- Inserts a new object of type anchor
hw_api->insertcollection -- Inserts a new object of type collection
hw_api->insertdocument -- Inserts a new object of type document
hw_api->link -- Creates a link to an object
hw_api->lock -- Locks an object
hw_api->move -- Moves object between collections
hw_api_content -- Create new instance of class hw_api_content
hw_api_object->assign -- Clones object
hw_api_object->attreditable -- Checks whether an attribute is editable
hw_api_object->count -- Returns number of attributes
hw_api_object->insert -- Inserts new attribute
hw_api_object -- Creates a new instance of class hw_api_object
hw_api_object->remove -- Removes attribute
hw_api_object->title -- Returns the title attribute
hw_api_object->value -- Returns value of attribute
hw_api->object -- Retrieve attribute information
hw_api->objectbyanchor -- Returns the object an anchor belongs to
hw_api->parents -- Returns parents of an object
hw_api_reason->description -- Returns description of reason
hw_api_reason->type -- Returns type of reason
hw_api->remove -- Delete an object
hw_api->replace -- Replaces an object
hw_api->setcommitedversion -- Commits version other than last version
hw_api->srcanchors -- Returns a list of all source anchors
hw_api->srcsofdst -- Returns source of a destination object
hw_api->unlock -- Unlocks a locked object
hw_api->user -- Returns the own user object
hw_api->userlist -- Returns a list of all logged in users

HW_API_CHECKIN_NORMAL: Checks in and commits the object. The object must be a document.
HW_API_CHECKIN_RECURSIVE: If the object to check in is a collection, all children will be checked in recursively if they are documents. Trying to check in a collection would result in an error.
HW_API_CHECKIN_FORCE_VERSION_CONTROL: Checks in an object even if it is not under version control.
HW_API_CHECKIN_REVERT_IF_NOT_CHANGED: Check if the new version is different from the last version. Unless this is the case the object will be checked in.
HW_API_CHECKIN_KEEP_TIME_MODIFIED: Keeps the time modified from the most recent object.
HW_API_CHECKIN_NO_AUTO_COMMIT: The object is not automatically commited on checkin.

hw_api->checkout

(no version information, might be only in CVS)

hw_api->checkout -- Checks out an object

Description

object checkout ( array parameter)

This function checks out an object or a whole hiearchie of objects. The parameters array contains the required element 'objectIdentifier' and the optional element 'version', 'mode' and 'objectQuery'. 'mode' can be one of the following values:

HW_API_CHECKIN_NORMAL: Checks out an object. The object must be a document.
HW_API_CHECKIN_RECURSIVE: If the object to check out is a collection, all children will be checked out recursively if they are documents. Trying to check out a collection would result in an error.

hw_api->children

(no version information, might be only in CVS)

hw_api->children -- Returns children of an object

Description

array children ( array parameter)

object ftstat ( array parameter)

hwapi_hgcsp

(no version information, might be only in CVS)

hwapi_hgcsp -- Returns object of class hw_api

Description

object hwapi_hgcsp ( string hostname [, int port])

Opens a connection to the Hyperwave server on host hostname. The protocol used is HGCSP. If you do not pass a port number, 418 is used.

hw_api->hwstat

(no version information, might be only in CVS)

hw_api->hwstat -- Returns statistics about Hyperwave server

Description

object hwstat ( array parameter)

hw_api->identify

(no version information, might be only in CVS)

hw_api->identify -- Log into Hyperwave Server

Description

object identify ( array parameter)

Logs into the Hyperwave Server. The parameter array must contain the elements 'username' und 'password'.

The return value will be an object of type HW_API_Error if identification failed or TRUE if it was successful.

hw_api->info

(no version information, might be only in CVS)

hw_api->info -- Returns information about server configuration

Description

object info ( array parameter)

hw_api->insert

(no version information, might be only in CVS)

hw_api->insert -- Inserts a new object

Description

object insert ( array parameter)

Insert a new object. The object type can be user, group, document or anchor. Depending on the type other object attributes has to be set. The parameter array contains the required elements 'object' and 'content' (if the object is a document) and the optional parameters 'parameters', 'mode' and 'attributeSelector'. The 'object' must contain all attributes of the object. 'parameters' is an object as well holding futher attributes like the destination (attribute key is 'Parent'). 'content' is the content of the document. 'mode' can be a combination of the following flags:

HW_API_INSERT_NORMAL: The object in inserted into the server.
HW_API_INSERT_FORCE-VERSION-CONTROL
HW_API_INSERT_AUTOMATIC-CHECKOUT
HW_API_INSERT_PLAIN
HW_API_INSERT_KEEP_TIME_MODIFIED
HW_API_INSERT_DELAY_INDEXING

The function returns true on success or an error object.

hw_api->lock

(no version information, might be only in CVS)

hw_api->lock -- Locks an object

Description

object lock ( array parameter)

Locks an object for exclusive editing by the user calling this function. The object can be only unlocked by this user or the sytem user. The parameter array contains the required element 'objectIdentifier' and the optional parameters 'mode' and 'objectquery'. 'mode' determines how an object is locked. HW_API_LOCK_NORMAL means, an object is locked until it is unlocked. HW_API_LOCK_RECURSIVE is only valid for collection and locks all objects within th collection und possible subcollections. HW_API_LOCK_SESSION means, an object is locked only as long as the session is valid.

hw_api->move

(no version information, might be only in CVS)

hw_api->move -- Moves object between collections

object replace ( array parameter)

Replaces the attributes and the content of an object The parameter array contains the required elements 'objectIdentifier' and 'object' and the optional parameters 'content', 'parameters', 'mode' and 'attributeSelector'. 'objectIdentifier' contains the object to be replaced. 'object' contains the new object. 'content' contains the new content. 'parameters' contain extra information for HTML documents. HTML_Language is the letter abbreviation of the language of the title. HTML_Base sets the base attribute of the HTML document. 'mode' can be a combination of the following flags:

HW_API_REPLACE_NORMAL: The object on the server is replace with the object passed.
HW_API_REPLACE_FORCE_VERSION_CONTROL
HW_API_REPLACE_AUTOMATIC_CHECKOUT
HW_API_REPLACE_AUTOMATIC_CHECKIN
HW_API_REPLACE_PLAIN
HW_API_REPLACE_REVERT_IF_NOT_CHANGED
HW_API_REPLACE_KEEP_TIME_MODIFIED

hw_api->setcommitedversion

(no version information, might be only in CVS)

hw_api->setcommitedversion -- Commits version other than last version

Description

object setcommitedversion ( array parameter)

object unlock ( array parameter)

Unlocks a locked object. Only the user who has locked the object and the system user may unlock an object. The parameter array contains the required element 'objectIdentifier' and the optional parameters 'mode' and 'objectquery'. The meaning of 'mode' is the same as in function hwapi_lock().

Returns true on success or an object of class HW_API_Error.

hw_api->user

(no version information, might be only in CVS)

hw_api->user -- Returns the own user object

Description

object user ( array parameter)

hw_api->userlist

(no version information, might be only in CVS)

hw_api->userlist -- Returns a list of all logged in users

Description

object userlist ( array parameter)

XL. iconv functions

Introduction

This module contains an interface to the iconv library functions. The iconv library functions convert strings between various character sets encodings. The supported character sets depend on the iconv() implementation on your system. Note that the iconv() function on some systems may not work as well as you expect. In this case, you should install the libiconv library.

Requirements

Your systems standard C library must provide the iconv() function or you must have libiconv installed on your system. The libiconv library is available from http://www.gnu.org/software/libiconv/.

Installation

To be able to use the functions defined in this module you must compile your PHP interpreter using the configure line --with-iconv[=DIR].

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Iconv configuration options

Name	Default	Changeable
iconv.input_encoding	ICONV_INPUT_ENCODING	PHP_INI_ALL
iconv.output_encoding	ICONV_OUTPUT_ENCODING	PHP_INI_ALL
iconv.internal_encoding	ICONV_INTERNAL_ENCODING	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

iconv_get_encoding

(PHP 4 >= 4.0.5)

iconv_get_encoding -- Get current setting for character encoding conversion

Description

array iconv_get_encoding ( [string type])

It returns the current settings of ob_iconv_handler() as array or FALSE on failure. The value of the optinal type can be:

all

input_encoding

output_encoding

internal_encoding

If type is omitted or not 'all' iconv_get_encoding() returns the current settings of ob_iconv_handler() as string.

Example 1. iconv_get_encoding() example:
<pre> <?php iconv_set_encoding("internal_encoding", "UTF-8"); iconv_set_encoding("output_encoding", "ISO-8859-1"); var_dump(iconv_get_encoding('all')); ?> </pre>
The printout of the above program will be:
Array ( [input_encoding] => ISO-8859-1 [output_encoding] => ISO-8859-1 [internal_encoding] => UTF-8 )

iconv_set_encoding

(PHP 4 >= 4.0.5)

iconv_set_encoding -- Set current setting for character encoding conversion

Description

bool iconv_set_encoding ( string type, string charset)

It changes the value of type to charset. Returns TRUE on success or FALSE on failure.

The value of type can be:

input_encoding

output_encoding

internal_encoding

Example 1. iconv_set_encoding() example:
iconv_set_encoding("internal_encoding", "UTF-8"); iconv_set_encoding("output_encoding", "ISO-8859-1");

iconv

(PHP 4 >= 4.0.5)

iconv -- Convert string to requested character encoding

Description

string iconv ( string in_charset, string out_charset, string str)

It converts the string str encoded in in_charset to the string encoded in out_charset. It returns the converted string or FALSE, if it fails.

Example 1. iconv() example:
echo iconv("ISO-8859-1","UTF-8","This is a test.");

ob_iconv_handler

(PHP 4 >= 4.0.5)

ob_iconv_handler -- Convert character encoding as output buffer handler

Description

array ob_iconv_handler ( string contents, int status)

It converts the string encoded in internal_encoding to output_encoding.

internal_encoding and output_encoding should be defined by iconv_set_encoding() or in the configuration file php.ini.

Example 1. ob_iconv_handler() example:
ob_start("ob_iconv_handler"); // start output buffering

XLI. Image functions

Introduction

PHP is not limited to creating just HTML output. It can also be used to create and manipulate image files in a variety of different image formats, including gif, png, jpg, wbmp, and xpm. Even more convenient, PHP can output image streams directly to a browser. You will need to compile PHP with the GD library of image functions for this to work. GD and PHP may also require other libraries, depending on which image formats you want to work with.

You can use the image functions in PHP to get the size of JPEG, GIF, PNG, SWF, TIFF and JPEG2000 images.

Note: Read requirements section about how to expand image capabilities to read, write and modify images and to read meta data of pictures taken by digital cameras.

Requirements

If you have the GD library (available at http://www.boutell.com/gd/) you will also be able to create and manipulate images.

The format of images you are able to manipulate depend on the version of GD you install, and any other libraries GD might need to access those image formats. Versions of GD older than gd-1.6 support gif format images, and do not support png, where versions greater than gd-1.6 support png, not gif.

Note: Since PHP 4.3 there is a bundled version of the GD lib. This bundled version has some additional features like alpha blending and should be used in preference to the external library since it's codebase is better maintained and more stable.

If you have PHP compiled with --enable-exif you are able to work with information stored in headers of JPEG and TIFF images. This way you can read meta data generated by digital cameras as mentioned above. These functions does not require the GD library.

Note: PHP does not require any additional library for exif the module.

Installation

In order to read and write images in jpeg format, you will need to obtain and install jpeg-6b (available at ftp://ftp.uu.net/graphics/jpeg/), and then recompile GD to make use of jpeg-6b. You will also have to compile PHP with --with-jpeg-dir=/path/to/jpeg-6b.

To add support for Type 1 fonts, you can install t1lib (available at ftp://sunsite.unc.edu/pub/Linux/libs/graphics/), and then add --with-t1lib[=dir].

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Exif supports automatically conversion for Unicode and JIS character encodings of user comments when module mbstring is available. This is done by first decoding the comment using the specified characterset. The result is then encoded with another characterset which should match your HTTP output.

Table 1. Exif configuration options

Name	Default	Changeable
exif.encode_unicode	"ISO-8859-15"	PHP_INI_ALL
exif.decode_unicode_motorola	"UCS-2BE"	PHP_INI_ALL
exif.decode_unicode_intel	"UCS-2LE"	PHP_INI_ALL
exif.encode_jis	""	PHP_INI_ALL
exif.decode_jis_motorola	"JIS"	PHP_INI_ALL
exif.decode_jis_intel	"JIS"	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Here is a short explanation of the configuration directives.

exif.encode_unicode string: exif.encode_unicode defines the characterset UNICODE user comments are handled. This defaults to ISO-8859-15 which should work for most non asian countries. The setting can be empty or must be an encoding supported by mbstring. If it is empty the current internal encoding of mbstring is used.
exif.decode_unicode_motorola string: exif.decode_unicode_motorola defines the image internal characterset for Unicode encoded user comments if image is in motorola byte order (big-endian). This setting cannot be empty but you can specify a list of encodings supported by mbstring. The default is UCS-2BE.
exif.decode_unicode_intel string: exif.decode_unicode_intel defines the image internal characterset for Unicode encoded user comments if image is in intel byte order (little-endian). This setting cannot be empty but you can specify a list of encodings supported by mbstring. The default is UCS-2LE.
exif.encode_jis string: exif.encode_jis defines the characterset JIS user comments are handled. This defaults to an empty value which forces the functions to use the current internal encoding of mbstring.
exif.decode_jis_motorola string: exif.decode_jis_motorola defines the image internal characterset for JIS encoded user comments if image is in motorola byte order (big-endian). This setting cannot be empty but you can specify a list of encodings supported by mbstring. The default is JIS.
exif.decode_jis_intel string: exif.decode_jis_intel defines the image internal characterset for JIS encoded user comments if image is in intel byte order (little-endian). This setting cannot be empty but you can specify a list of encodings supported by mbstring. The default is JIS.

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

IMG_GIF (integer)
IMG_JPG (integer)
IMG_JPEG (integer)
IMG_PNG (integer)
IMG_WBMP (integer)
IMG_XPM (integer)
IMG_COLOR_TILED (integer)
IMG_COLOR_STYLED (integer)
IMG_COLOR_BRUSHED (integer)
IMG_COLOR_STYLEDBRUSHED (integer)
IMG_COLOR_TRANSPARENT (integer)
IMG_ARC_ROUNDED (integer)
IMG_ARC_PIE (integer)
IMG_ARC_CHORD (integer)
IMG_ARC_NOFILL (integer)
IMG_ARC_EDGED (integer)
IMAGETYPE_GIF (integer)
IMAGETYPE_JPG (integer)
IMAGETYPE_PNG (integer)
IMAGETYPE_SWF (integer)
IMAGETYPE_PSD (integer)
IMAGETYPE_BMP (integer)
IMAGETYPE_TIFF_II (integer)
IMAGETYPE_TIFF_MM (integer)
IMAGETYPE_JPC (integer)
IMAGETYPE_JP2 (integer)
IMAGETYPE_JPX (integer)
IMAGETYPE_SWC (integer)

Examples

Example 1. PNG creation with PHP
<?php header("Content-type: image/png"); $string = $_GET['text']; $im = imagecreatefrompng("images/button1.png"); $orange = imagecolorallocate($im, 220, 210, 60); $px = (imagesx($im) - 7.5 * strlen($string)) / 2; imagestring($im, 3, $px, 9, $string, $orange); imagepng($im); imagedestroy($im); ?>
This example would be called from a page with a tag like: <img src="button.php?text">. The above button.php script then takes this "text" string and overlays it on top of a base image which in this case is "images/button1.png" and outputs the resulting image. This is a very convenient way to avoid having to draw new button images every time you want to change the text of a button. With this method they are dynamically generated.

Table of Contents
exif_imagetype -- Determine the type of an image
exif_read_data -- Read the EXIF headers from JPEG or TIFF. This way you can read meta data generated by digital cameras.
exif_thumbnail -- Retrieve the embedded thumbnail of a TIFF or JPEG image
getimagesize -- Get the size of an image
image_type_to_mime_type -- Get Mime-Type for image-type returned by getimagesize, exif_read_data, exif_thumbnail, exif_imagetype
image2wbmp -- Output image to browser or file
imagealphablending -- Set the blending mode for an image
imagearc -- Draw a partial ellipse
imagechar -- Draw a character horizontally
imagecharup -- Draw a character vertically
imagecolorallocate -- Allocate a color for an image
imagecolorat -- Get the index of the color of a pixel
imagecolorclosest -- Get the index of the closest color to the specified color
imagecolorclosestalpha -- Get the index of the closest color to the specified color + alpha
imagecolorclosesthwb -- Get the index of the color which has the hue, white and blackness nearest to the given color
imagecolordeallocate -- De-allocate a color for an image
imagecolorexact -- Get the index of the specified color
imagecolorexactalpha -- Get the index of the specified color + alpha
imagecolorresolve -- Get the index of the specified color or its closest possible alternative
imagecolorresolvealpha -- Get the index of the specified color + alpha or its closest possible alternative
imagecolorset -- Set the color for the specified palette index
imagecolorsforindex -- Get the colors for an index
imagecolorstotal -- Find out the number of colors in an image's palette
imagecolortransparent -- Define a color as transparent
imagecopy -- Copy part of an image
imagecopymerge -- Copy and merge part of an image
imagecopymergegray -- Copy and merge part of an image with gray scale
imagecopyresampled -- Copy and resize part of an image with resampling
imagecopyresized -- Copy and resize part of an image
imagecreate -- Create a new palette based image
imagecreatefromgd2 -- Create a new image from GD2 file or URL
imagecreatefromgd2part -- Create a new image from a given part of GD2 file or URL
imagecreatefromgd -- Create a new image from GD file or URL
imagecreatefromgif -- Create a new image from file or URL
imagecreatefromjpeg -- Create a new image from file or URL
imagecreatefrompng -- Create a new image from file or URL
imagecreatefromstring -- Create a new image from the image stream in the string
imagecreatefromwbmp -- Create a new image from file or URL
imagecreatefromxbm -- Create a new image from file or URL
imagecreatefromxpm -- Create a new image from file or URL
imagecreatetruecolor -- Create a new true color image
imagedashedline -- Draw a dashed line
imagedestroy -- Destroy an image
imageellipse -- Draw an ellipse
imagefill -- Flood fill
imagefilledarc -- Draw a partial ellipse and fill it
imagefilledellipse -- Draw a filled ellipse
imagefilledpolygon -- Draw a filled polygon
imagefilledrectangle -- Draw a filled rectangle
imagefilltoborder -- Flood fill to specific color
imagefontheight -- Get font height
imagefontwidth -- Get font width
imageftbbox -- Give the bounding box of a text using fonts via freetype2
imagefttext -- Write text to the image using fonts using FreeType 2
imagegammacorrect -- Apply a gamma correction to a GD image
imagegd2 -- Output GD2 image to browser or file
imagegd -- Output GD image to browser or file
imagegif -- Output image to browser or file
imageinterlace -- Enable or disable interlace
imagejpeg -- Output image to browser or file
imageline -- Draw a line
imageloadfont -- Load a new font
imagepalettecopy -- Copy the palette from one image to another
imagepng -- Output a PNG image to either the browser or a file
imagepolygon -- Draw a polygon
imagepsbbox -- Give the bounding box of a text rectangle using PostScript Type1 fonts
imagepscopyfont -- Make a copy of an already loaded font for further modification
imagepsencodefont -- Change the character encoding vector of a font
imagepsextendfont -- Extend or condense a font
imagepsfreefont -- Free memory used by a PostScript Type 1 font
imagepsloadfont -- Load a PostScript Type 1 font from file
imagepsslantfont -- Slant a font
imagepstext -- To draw a text string over an image using PostScript Type1 fonts
imagerectangle -- Draw a rectangle
imagesetbrush -- Set the brush image for line drawing
imagesetpixel -- Set a single pixel
imagesetstyle -- Set the style for line drawing
imagesetthickness -- Set the thickness for line drawing
imagesettile -- Set the tile image for filling
imagestring -- Draw a string horizontally
imagestringup -- Draw a string vertically
imagesx -- Get image width
imagesy -- Get image height
imagetruecolortopalette -- Convert a true color image to a palette image
imagettfbbox -- Give the bounding box of a text using TrueType fonts
imagettftext -- Write text to the image using TrueType fonts
imagetypes -- Return the image types supported by this PHP build
imagewbmp -- Output image to browser or file
iptcembed -- Embed binary IPTC data into a JPEG image
iptcparse -- Parse a binary IPTC http://www.iptc.org/ block into single tags.
jpeg2wbmp -- Convert JPEG image file to WBMP image file
png2wbmp -- Convert PNG image file to WBMP image file
read_exif_data -- Reads header information stored in TIFF and JPEG images

exif_imagetype

(PHP 4 CVS only)

exif_imagetype -- Determine the type of an image

Description

int|false exif_imagetype ( string filename)

exif_imagetype() reads the first bytes of an image and checks its signature. When a correct signature is found a constant will be returned otherwise the return value is FALSE. The return value is the same value that getimagesize() returns in index 2 but this function is much faster.

The following constants are defined: 1 = IMAGETYPE_GIF, 2 = IMAGETYPE_JPG, 3 = IMAGETYPE_PNG, 4 = IMAGETYPE_SWF, 5 = IMAGETYPE_PSD, 6 = IMAGETYPE_BMP, 7 = IMAGETYPE_TIFF_II (intel byte order), 8 = IMAGETYPE_TIFF_MM (motorola byte order), 9 = IMAGETYPE_JPC, 10 = IMAGETYPE_JP2, 11 = IMAGETYPE_JPX, 12 = IMAGETYPE_SWC.

This function can be used to avoid calls to other exif functions with unsupported file teypes or in conjunction with $_SERVER['HTTP_ACCEPT'] to check whether or not the viewer is able to see a specific image in his browser.

Note: This function is only available in PHP 4 compiled using --enable-exif.
This function does not require the GD image library.
See also getimagesize().

exif_read_data

(PHP 4 >= 4.2.0)

exif_read_data -- Read the EXIF headers from JPEG or TIFF. This way you can read meta data generated by digital cameras.

Description

array exif_read_data ( string filename [, string sections [, bool arrays [, bool thumbnail]]])

The exif_read_data() function reads the EXIF headers from a JPEG or TIFF image file. It returns an associative array where the indexes are the header names and the values are the values associated with those headers. If no data can be returned the result is FALSE.

filename is the name of the file to read. This cannot be a url.

sections a comma separated list of sections that need to be present in file to produce a result array.

FILE	FileName, FileSize, FileDateTime, SectionsFound
COMPUTED	html, Width, Height, IsColor and some more if available.
ANY_TAG	Any information that has a Tag e.g. IFD0, EXIF, ...
IFD0	All tagged data of IFD0. In normal imagefiles this contains image size and so forth.
THUMBNAIL	A file is supposed to contain a thumbnail if it has a second IFD. All tagged information about the embedded thumbnail is stored in this section.
COMMENT	Comment headers of JPEG images.
EXIF	The EXIF section is a sub section of IFD0. It contains more detailed information about an image. Most of these entries are digital camera related.

arrays specifies whether or not each section becomes an array. The sections FILE, COMPUTED and THUMBNAIL allways become arrays as they may contain values whose names are conflict with other sections.

thumbnail whether or not to read the thumbnail itself and not only its tagged data.

Note: Exif headers tend to be present in JPEG/TIFF images generated by digital cameras, but unfortunately each digital camera maker has a different idea of how to actually tag their images, so you can't always rely on a specific Exif header being present.

Example 1. exif_read_data() example
<?php echo "test1.jpg:<br />\n"; $exif = exif_read_data ('tests/test1.jpg','IFD0'); echo $exif===false ? "No header data found.<br />\n" : "Image contains headers<br />"; $exif = exif_read_data ('tests/test2.jpg',0,true); echo "test2.jpg:<br />\n"; foreach($exif as $key=>$section) { foreach($section as $name=>$val) { echo "$key.$name: $val<br />\n"; } }?>
The first call fails because the image has no header information.
test1.jpg: No header data found. test2.jpg: FILE.FileName: test2.jpg FILE.FileDateTime: 1017666176 FILE.FileSize: 1240 FILE.FileType: 2 FILE.SectionsFound: ANY_TAG, IFD0, THUMBNAIL, COMMENT COMPUTED.html: width="1" height="1" COMPUTED.Height: 1 COMPUTED.Width: 1 COMPUTED.IsColor: 1 COMPUTED.ByteOrderMotorola: 1 COMPUTED.UserComment: Exif test image. COMPUTED.UserCommentEncoding: ASCII COMPUTED.Copyright: Photo (c) M.Boerger, Edited by M.Boerger. COMPUTED.Copyright.Photographer: Photo (c) M.Boerger COMPUTED.Copyright.Editor: Edited by M.Boerger. IFD0.Copyright: Photo (c) M.Boerger IFD0.UserComment: ASCII THUMBNAIL.JPEGInterchangeFormat: 134 THUMBNAIL.JPEGInterchangeFormatLength: 523 COMMENT.0: Comment #1. COMMENT.1: Comment #2. COMMENT.2: Comment #3end THUMBNAIL.JPEGInterchangeFormat: 134 THUMBNAIL.Thumbnail.Height: 1 THUMBNAIL.Thumbnail.Height: 1

Note: If the image contains any IFD0 data then COMPUTED contains the entry ByteOrderMotorola which is 0 for little-endian (intel) and 1 for big-endian (motorola) byte order. This was added in PHP 4.3.
When an Exif header contains a Copyright note this itself can contain two values. As the solution is inconsitent in the Exif 2.10 standard the COMPUTED section will return both entries Copyright.Photographer and Copyright.Editor while the IFD0 sections contains the byte array with the NULL character that splits both entries. Or just the first entry if the datatype was wrong (normal behaviour of Exif). The COMPUTED will contain also an entry Copyright Which is either the original copyright string or it is a comma separated list of photo and editor copyright.

Note: The tag UserComment has the same problem as the Copyright tag. It can store two values first the encoding used and second the value itself. If so the IFD section only contains the encoding or a byte array. The COMPUTED section will store both in the entries UserCommentEncoding and UserComment. The entry UserComment is available in both cases so it should be used in preference to the value in IFD0 section.
If the user comment uses Unicode or JIS encoding and the module mbstring is available this encoding will automatically changed according to the exif ini settings. This was added in PHP 4.3.

Note: Height and Width are computed the same way getimagesize() does so their values must not be part of any header returned. Also html is a height/width text string to be used inside normal HTML.

Note: Starting from PHP 4.3 the function can read all embedded IFD data including arrays (returned as such). Also the size of an embedded thumbnail is returned in THUMBNAIL subarray and the function exif_read_data() can return thumbnails in TIFF format. Last but not least there is no longer a maximum legth for returned values (not until memory limit is reached).

Note: This function is only available in PHP 4 compiled using --enable-exif. Its functionality and behaviour has changed in PHP 4.2. Earlier versions are very unstable.
Since PHP 4.3 user comment can automatically change encoding if PHP 4 was compiled using --enable-mbstring.
This function does not require the GD image library.
See also exif_thumbnail() and getimagesize().

exif_thumbnail

(PHP 4 >= 4.2.0)

exif_thumbnail -- Retrieve the embedded thumbnail of a TIFF or JPEG image

Description

string exif_thumbnail ( string filename [, int &width [, int &height [, int &imagetype]]])

exif_thumbnail() reads the embedded thumbnail of a TIFF or JPEG image. If the image contains no thumbnail FALSE will be returned.

The parameters width, height and imagetype are available since PHP 4.3 and return the size of the thumbnail as well as its type. It is possible that exif_thumbnail() cannot create an image but determine its size. In this case the return value is FALSE but width and height are set.

If you want to deliver thumbnails through this function you should send the mimetype information using header() function. The following example demonstrates this:
Example 1. exif_thumbnail() example
<?php if (array_key_exists('file',$_REQUEST)) { $image = exif_thumbnail($_REQUEST['file'], $width, $height, $type); } else { $image = false; } if ($image!==false) { header("Content-type: ".image_type_to_mime_type($type)); echo $image; exit; } else { // no thumbnail available, handle the error here echo "No thumbnail available"; } ?>

Starting from version PHP 4.3 the function exif_thumbnail() can return thumbnails in TIFF format.

Note: This function is only available in PHP 4 compiled using --enable-exif. Its functionality and behaviour has changed in PHP 4.2
This function does not require the GD image library.
See also exif_read_data() and image_type_to_mime_type().

getimagesize

(PHP 3, PHP 4 )

getimagesize -- Get the size of an image

Description

array getimagesize ( string filename [, array imageinfo])

The getimagesize() function will determine the size of any GIF, JPG, PNG, SWF, SWC, PSD, TIFF, BMP or IFF image file and return the dimensions along with the file type and a height/width text string to be used inside a normal HTML IMG tag.

Returns an array with 4 elements. Index 0 contains the width of the image in pixels. Index 1 contains the height. Index 2 is a flag indicating the type of the image: 1 = GIF, 2 = JPG, 3 = PNG, 4 = SWF, 5 = PSD, 6 = BMP, 7 = TIFF(intel byte order), 8 = TIFF(motorola byte order), 9 = JPC, 10 = JP2, 11 = JPX, 12 = JB2, 13 = SWC, 14 = IFF. These values correspond to the IMAGETYPE constants that were added in PHP 4.3. Index 3 is a text string with the correct height="yyy" width="xxx" string that can be used directly in an IMG tag.
Example 1. getimagesize (file)
<?php $size = getimagesize ("img/flag.jpg"); echo "<img src=\"img/flag.jpg\" {$size[3]}>"; ?>

Example 2. getimagesize (URL)
<?php $size = getimagesize ("http://www.example.com/gifs/logo.gif"); ?>

With JPG images, two extra indexes are returned: channels and bits. channels will be 3 for RGB pictures and 4 for CMYK pictures. bits is the number of bits for each color.

Beginning with PHP 4.3, bits and channels are present for other image types, too. However, the presence of these values can be a bit confusing. As an example, GIF always uses 3 channels per pixel, but the number of bits per pixel cannot be calculated for an animated GIF with a global color table.

Some formats may contain no image or may contain multiple images. In these cases, getimagesize() might not be able to properly determine the image size. getimagesize() will return zero for width and height in these cases.

Beginning with PHP 4.3, getimagesize() also returns an additional parameter, MIME, that corresponds with the MIME type of the image. This information can be used to deliver images with correct HTTP Content-type headers:
Example 3. getimagesize() and MIME types
<?php $size = getimagesize ($filename); $fp=fopen($filename, "rb"); if ($size && $fp) { header("Content-type: {$size['mime']}"); fpassthru($fp); exit; } else { // error } ?>

If accessing the filename image is impossible, or if it isn't a valid picture, getimagesize() will return FALSE and generate a warning.

The optional imageinfo parameter allows you to extract some extended information from the image file. Currently, this will return the different JPG APP markers as an associative array. Some programs use these APP markers to embed text information in images. A very common one is to embed IPTC http://www.iptc.org/ information in the APP13 marker. You can use the iptcparse() function to parse the binary APP13 marker into something readable.
Example 4. getimagesize() returning IPTC
<?php $size = getimagesize ("testimg.jpg",&$info); if (isset ($info["APP13"])) { $iptc = iptcparse ($info["APP13"]); var_dump ($iptc); } ?>

Note: TIFF support was added in PHP 4.2. JPEG2000 support will be added in PHP 4.3.
This function does not require the GD image library.
See also image_type_to_mime_type(), exif_imagetype(), exif_read_data() and exif_thumbnail().
URL support was added in PHP 4.0.5.

image_type_to_mime_type

(PHP 4 CVS only)

image_type_to_mime_type -- Get Mime-Type for image-type returned by getimagesize, exif_read_data, exif_thumbnail, exif_imagetype

Description

string image_type_to_mime_type ( int imagetype)

The image_type_to_mime_type() function will determine the Mime-Type for an IMAGETYPE constant.
Example 1. image_type_to_mime_type (file)
<?php header ("Content-type: ".image_type_to_mime_type (IMAGETYPE_PNG)); ?>

Note: This function does not require the GD image library.
See also getimagesize(), exif_imagetype(), exif_read_data() and exif_thumbnail().

image2wbmp

(PHP 4 >= 4.0.5)

image2wbmp -- Output image to browser or file

Description

int image2wbmp ( resource image [, string filename [, int threshold]])

image2wbmp() creates the WBMP file in filename from the image image. The image argument is the return from imagecreate().

The filename argument is optional, and if left off, the raw image stream will be output directly. By sending an image/vnd.wap.wbmp content-type using header(), you can create a PHP script that outputs WBMP images directly.

Note: WBMP support is only available if PHP was compiled against GD-1.8 or later.

imagealphablending

(PHP 4 >= 4.0.6)

imagealphablending -- Set the blending mode for an image

Description

int imagealphablending ( resource image, bool blendmode)

imagealphablending() allows for two different modes of drawing on truecolor images. In blending mode, the alpha channel component of the color supplied to all drawing function, such as imagesetpixel() determines how much of the underlying color should be allowed to shine through. As a result, gd automatically blends the existing color at that point with the drawing color, and stores the result in the image. The resulting pixel is opaque. In non-blending mode, the drawing color is copied literally with its alpha channel information, replacing the destination pixel. Blending mode is not available when drawing on palette images. If blendmode is TRUE, then blending mode is enabled, otherwise disabled.

Note: This function was added in PHP 4.0.6 and requires GD 2.0.1

imagearc

(PHP 3, PHP 4 )

imagearc -- Draw a partial ellipse

int imagecolorallocate ( resource image, int red, int green, int blue)

imagecolorallocate() returns a color identifier representing the color composed of the given RGB components. The im argument is the return from the imagecreate() function. red, green and blue are the values of the red, green and blue component of the requested color respectively. These parameters are integers between 0 and 255. imagecolorallocate() must be called to create each color that is to be used in the image represented by image.

$white = imagecolorallocate ($im, 255, 255, 255);
$black = imagecolorallocate ($im, 0, 0, 0);

int imagecolortransparent ( resource image [, int color])

imagecolortransparent() sets the transparent color in the image image to color. image is the image identifier returned by imagecreate() and color is a color identifier returned by imagecolorallocate().

Note: The transparent color is a property of the image, transparency is not a property of the color. Once you have a set a color to be the transparent color, any regions of the image in that color that were drawn previously will be transparent.

The identifier of the new (or current, if none is specified) transparent color is returned.

imagecopy

(PHP 3>= 3.0.6, PHP 4 )

imagecopy -- Copy part of an image

Description

int imagecopy ( resource dst_im, resource src_im, int dst_x, int dst_y, int src_x, int src_y, int src_w, int src_h)

imagecopymerge

(PHP 4 >= 4.0.1)

imagecopymerge -- Copy and merge part of an image

Description

int imagecopymerge ( resource dst_im, resource src_im, int dst_x, int dst_y, int src_x, int src_y, int src_w, int src_h, int pct)

Copy a part of src_im onto dst_im starting at the x,y coordinates src_x, src_y with a width of src_w and a height of src_h. The portion defined will be copied onto the x,y coordinates, dst_x and dst_y. The two images will be merged according to pct which can range from 0 to 100. When pct = 0, no action is taken, when 100 this function behaves identically to imagecopy().

Note: This function was added in PHP 4.0.6

imagecopymergegray

(PHP 4 >= 4.0.6)

imagecopymergegray -- Copy and merge part of an image with gray scale

Description

int imagecopymergegray ( resource dst_im, resource src_im, int dst_x, int dst_y, int src_x, int src_y, int src_w, int src_h, int pct)

imagecopymergegray() copy a part of src_im onto dst_im starting at the x,y coordinates src_x, src_y with a width of src_w and a height of src_h. The portion defined will be copied onto the x,y coordinates, dst_x and dst_y. The two images will be merged according to pct which can range from 0 to 100. When pct = 0, no action is taken, when 100 this function behaves identically to imagecopy().

This function is identical to imagecopymerge() except that when merging it preservese the hue of the source by converting the destination pixels to gray scale before the copy operation.

Note: This function was added in PHP 4.0.6

This function is currently not documented; only the argument list is available.

Tip: You can use a URL as a filename with this function if the fopen wrappers have been enabled. See fopen() for more details on how to specify the filename and Appendix I for a list of supported URL protocols.

Warning

Windows versions of PHP prior to PHP 4.3 do not support accessing remote files via this function, even if allow_url_fopen is enabled.

imagecreatefromgd2part

(PHP 4 >= 4.1.0)

imagecreatefromgd2part -- Create a new image from a given part of GD2 file or URL

Description

resource imagecreatefromgd2part ( string filename, int srcX, int srcY, int width, int height)

Warning

This function is currently not documented; only the argument list is available.

Tip: You can use a URL as a filename with this function if the fopen wrappers have been enabled. See fopen() for more details on how to specify the filename and Appendix I for a list of supported URL protocols.

Warning

Windows versions of PHP prior to PHP 4.3 do not support accessing remote files via this function, even if allow_url_fopen is enabled.

imagecreatefromgd

(PHP 4 >= 4.1.0)

imagecreatefromgd -- Create a new image from GD file or URL

Description

resource imagecreatefromgd ( string filename)

Warning

This function is currently not documented; only the argument list is available.

Tip: You can use a URL as a filename with this function if the fopen wrappers have been enabled. See fopen() for more details on how to specify the filename and Appendix I for a list of supported URL protocols.

Warning

Windows versions of PHP prior to PHP 4.3 do not support accessing remote files via this function, even if allow_url_fopen is enabled.

imagecreatefromgif

(PHP 3, PHP 4 )

imagecreatefromgif -- Create a new image from file or URL

Description

resource imagecreatefromgif ( string filename)

imagecreatefromgif() returns an image identifier representing the image obtained from the given filename.

imagecreatefromgif() returns an empty string on failure. It also outputs an error message, which unfortunately displays as a broken link in a browser. To ease debugging the following example will produce an error GIF:
Example 1. Example to handle an error during creation (courtesy vic@zymsys.com)
function LoadGif ($imgname) { $im = @imagecreatefromgif ($imgname); /* Attempt to open */ if (!$im) { /* See if it failed */ $im = imagecreate (150, 30); /* Create a blank image */ $bgc = imagecolorallocate ($im, 255, 255, 255); $tc = imagecolorallocate ($im, 0, 0, 0); imagefilledrectangle ($im, 0, 0, 150, 30, $bgc); /* Output an errmsg */ imagestring ($im, 1, 5, 5, "Error loading $imgname", $tc); } return $im; }

Note: Since all GIF support was removed from the GD library in version 1.6, this function is not available if you are using that version of the GD library.

Tip: You can use a URL as a filename with this function if the fopen wrappers have been enabled. See fopen() for more details on how to specify the filename and Appendix I for a list of supported URL protocols.

Warning

Windows versions of PHP prior to PHP 4.3 do not support accessing remote files via this function, even if allow_url_fopen is enabled.

imagecreatefromjpeg

(PHP 3>= 3.0.16, PHP 4 )

imagecreatefromjpeg -- Create a new image from file or URL

Description

resource imagecreatefromjpeg ( string filename)

imagecreatefromjpeg() returns an image identifier representing the image obtained from the given filename.

imagecreatefromjpeg() returns an empty string on failure. It also outputs an error message, which unfortunately displays as a broken link in a browser. To ease debugging the following example will produce an error JPEG:
Example 1. Example to handle an error during creation (courtesy vic@zymsys.com )
function LoadJpeg ($imgname) { $im = @imagecreatefromjpeg ($imgname); /* Attempt to open */ if (!$im) { /* See if it failed */ $im = imagecreate (150, 30); /* Create a blank image */ $bgc = imagecolorallocate ($im, 255, 255, 255); $tc = imagecolorallocate ($im, 0, 0, 0); imagefilledrectangle ($im, 0, 0, 150, 30, $bgc); /* Output an errmsg */ imagestring ($im, 1, 5, 5, "Error loading $imgname", $tc); } return $im; }

Tip: You can use a URL as a filename with this function if the fopen wrappers have been enabled. See fopen() for more details on how to specify the filename and Appendix I for a list of supported URL protocols.

Warning

Windows versions of PHP prior to PHP 4.3 do not support accessing remote files via this function, even if allow_url_fopen is enabled.

imagecreatefrompng

(PHP 3>= 3.0.13, PHP 4 )

imagecreatefrompng -- Create a new image from file or URL

Description

resource imagecreatefrompng ( string filename)

imagecreatefrompng() returns an image identifier representing the image obtained from the given filename.

imagecreatefrompng() returns an empty string on failure. It also outputs an error message, which unfortunately displays as a broken link in a browser. To ease debugging the following example will produce an error PNG:
Example 1. Example to handle an error during creation (courtesy vic@zymsys.com)
function LoadPNG ($imgname) { $im = @imagecreatefrompng ($imgname); /* Attempt to open */ if (!$im) { /* See if it failed */ $im = imagecreate (150, 30); /* Create a blank image */ $bgc = imagecolorallocate ($im, 255, 255, 255); $tc = imagecolorallocate ($im, 0, 0, 0); imagefilledrectangle ($im, 0, 0, 150, 30, $bgc); /* Output an errmsg */ imagestring ($im, 1, 5, 5, "Error loading $imgname", $tc); } return $im; }

Tip: You can use a URL as a filename with this function if the fopen wrappers have been enabled. See fopen() for more details on how to specify the filename and Appendix I for a list of supported URL protocols.

Warning

Windows versions of PHP prior to PHP 4.3 do not support accessing remote files via this function, even if allow_url_fopen is enabled.

imagecreatefromstring

(PHP 4 >= 4.0.4)

imagecreatefromstring -- Create a new image from the image stream in the string

Description

resource imagecreatefromstring ( string image)

imagecreatefromstring() returns an image identifier representing the image obtained from the given string.

imagecreatefromwbmp

(PHP 4 >= 4.0.1)

imagecreatefromwbmp -- Create a new image from file or URL

Description

resource imagecreatefromwbmp ( string filename)

imagecreatefromwbmp() returns an image identifier representing the image obtained from the given filename.

imagecreatefromwbmp() returns an empty string on failure. It also outputs an error message, which unfortunately displays as a broken link in a browser. To ease debugging the following example will produce an error WBMP:
Example 1. Example to handle an error during creation (courtesy vic@zymsys.com)
function LoadWBMP ($imgname) { $im = @imagecreatefromwbmp ($imgname); /* Attempt to open */ if (!$im) { /* See if it failed */ $im = imagecreate (20, 20); /* Create a blank image */ $bgc = imagecolorallocate ($im, 255, 255, 255); $tc = imagecolorallocate ($im, 0, 0, 0); imagefilledrectangle ($im, 0, 0, 10, 10, $bgc); /* Output an errmsg */ imagestring ($im, 1, 5, 5, "Error loading $imgname", $tc); } return $im; }

Note: WBMP support is only available if PHP was compiled against GD-1.8 or later.

Tip: You can use a URL as a filename with this function if the fopen wrappers have been enabled. See fopen() for more details on how to specify the filename and Appendix I for a list of supported URL protocols.

Warning

Windows versions of PHP prior to PHP 4.3 do not support accessing remote files via this function, even if allow_url_fopen is enabled.

imagecreatefromxbm

(PHP 4 >= 4.0.1)

imagecreatefromxbm -- Create a new image from file or URL

Description

resource imagecreatefromxbm ( string filename)

imagecreatefromxbm() returns an image identifier representing the image obtained from the given filename.

Tip: You can use a URL as a filename with this function if the fopen wrappers have been enabled. See fopen() for more details on how to specify the filename and Appendix I for a list of supported URL protocols.

Warning

Windows versions of PHP prior to PHP 4.3 do not support accessing remote files via this function, even if allow_url_fopen is enabled.

imagecreatefromxpm

(PHP 4 >= 4.0.1)

imagecreatefromxpm -- Create a new image from file or URL

Description

resource imagecreatefromxpm ( string filename)

imagecreatefromxpm() returns an image identifier representing the image obtained from the given filename.

Tip: You can use a URL as a filename with this function if the fopen wrappers have been enabled. See fopen() for more details on how to specify the filename and Appendix I for a list of supported URL protocols.

Warning

Windows versions of PHP prior to PHP 4.3 do not support accessing remote files via this function, even if allow_url_fopen is enabled.

imagecreatetruecolor

(PHP 4 >= 4.0.6)

imagecreatetruecolor -- Create a new true color image

Description

resource imagecreatetruecolor ( int x_size, int y_size)

imagecreatetruecolor() returns an image identifier representing a black image of size x_size by y_size.

Note: This function was added in PHP 4.0.6 and requires GD 2.0.1 or later

Note: This function will not work with GIF file formats.

Note: This function was added in PHP 4.0.6 and requires GD 2.0.2 or later

imagefill

int imagefilledellipse ( resource image, int cx, int cy, int w, int h, int col)

imagefilledellipse() draws an ellipse centered at cx, cy (top left is 0, 0) in the image represented by image. W and h specifies the ellipse's width and height respectively. The ellipse is filled using color

Note: This function was added in PHP 4.0.6 and requires GD 2.0.1 or later

This function is currently not documented; only the argument list is available.

imagefttext

(PHP 4 >= 4.1.0)

imagefttext -- Write text to the image using fonts using FreeType 2

Description

array imagefttext ( resource image, int size, int angle, int x, int y, int col, string font_file, string text [, array extrainfo])

Warning

This function is currently not documented; only the argument list is available.

imagegammacorrect

(PHP 3>= 3.0.13, PHP 4 )

imagegammacorrect -- Apply a gamma correction to a GD image

int imagegif ( resource image [, string filename])

imagegif() creates the GIF file in filename from the image image. The image argument is the return from the imagecreate() function.

The image format will be GIF87a unless the image has been made transparent with imagecolortransparent(), in which case the image format will be GIF89a.

The filename argument is optional, and if left off, the raw image stream will be output directly. By sending an image/gif content-type using header(), you can create a PHP script that outputs GIF images directly.

Note: Since all GIF support was removed from the GD library in version 1.6, this function is not available if you are using that version of the GD library.
The following code snippet allows you to write more portable PHP applications by auto-detecting the type of GD support which is available. Replace the sequence header ("Content-type: image/gif"); imagegif ($im); by the more flexible sequence:
<?php
if (function_exists("imagegif")) {
    header ("Content-type: image/gif");
    imagegif ($im);
}
elseif (function_exists("imagejpeg")) {
    header ("Content-type: image/jpeg");
    imagejpeg ($im, "", 0.5);
}
elseif (function_exists("imagepng")) {
    header ("Content-type: image/png");
    imagepng ($im);
}
elseif (function_exists("imagewbmp")) {
    header ("Content-type: image/vnd.wap.wbmp");
    imagewbmp ($im);
}
else
    die("No image support in this PHP server");
?>

Note: As of version 3.0.18 and 4.0.2 you can use the function imagetypes() in place of function_exists() for checking the presence of the various supported image formats:
if (imagetypes() & IMG_GIF) {
    header ("Content-type: image/gif");
    imagegif ($im);
}
elseif (imagetypes() & IMG_JPG) {
        ... etc.

imageinterlace

(PHP 3, PHP 4 )

imageinterlace -- Enable or disable interlace

Description

int imageinterlace ( resource image [, int interlace])

imageinterlace() turns the interlace bit on or off. If interlace is 1 the image will be interlaced, and if interlace is 0 the interlace bit is turned off.

If the interlace bit is set and the image is used as a JPEG image, the image is created as a progressive JPEG.

This function returns whether the interlace bit is set for the image.

imagejpeg

(PHP 3>= 3.0.16, PHP 4 )

imagejpeg -- Output image to browser or file

Description

int imagejpeg ( resource image [, string filename [, int quality]])

imagejpeg() creates the JPEG file in filename from the image image. The image argument is the return from the imagecreate() function.

The filename argument is optional, and if left off, the raw image stream will be output directly. To skip the filename argument in order to provide a quality argument just use an empty string (''). By sending an image/jpeg content-type using header(), you can create a PHP script that outputs JPEG images directly.

Note: JPEG support is only available if PHP was compiled against GD-1.8 or later.

quality is optional, and ranges from 0 (worst quality, smaller file) to 100 (best quality, biggest file). The default is the default IJG quality value (about 75).

If you want to output Progressive JPEGs, you need to set interlacing on with imageinterlace().

imageline

int imagepng ( resource image [, string filename])

The imagepng() outputs a GD image stream (image) in PNG format to standard output (usually the browser) or, if a filename is given by the filename it outputs the image to the file.

<?php
$im = imagecreatefrompng ("test.png");
imagepng ($im);
?>

imagepolygon

(PHP 3, PHP 4 )

imagepolygon -- Draw a polygon

Description

int imagepolygon ( resource image, array points, int num_points, int col)

imagepolygon() creates a polygon in image id. points is a PHP array containing the polygon's vertices, ie. points[0] = x0, points[1] = y0, points[2] = x1, points[3] = y1, etc. num_points is the total number of vertices.

imagepsbbox

(PHP 3>= 3.0.9, PHP 4 )

imagepsbbox -- Give the bounding box of a text rectangle using PostScript Type1 fonts

Description

array imagepsbbox ( string text, int font, int size [, int space [, int tightness [, float angle]]])

Size is expressed in pixels.

Space allows you to change the default value of a space in a font. This amount is added to the normal value and can also be negative.

Tightness allows you to control the amount of white space between characters. This amount is added to the normal character width and can also be negative.

Angle is in degrees.

Parameters space and tightness are expressed in character space units, where 1 unit is 1/1000th of an em-square.

Parameters space, tightness, and angle are optional.

The bounding box is calculated using information available from character metrics, and unfortunately tends to differ slightly from the results achieved by actually rasterizing the text. If the angle is 0 degrees, you can expect the text to need 1 pixel more to every direction.

This function returns an array containing the following elements:

0	lower left x-coordinate
1	lower left y-coordinate
2	upper right x-coordinate
3	upper right y-coordinate

imagepscopyfont

(PHP 3>= 3.0.9, PHP 4 )

imagepscopyfont -- Make a copy of an already loaded font for further modification

Description

int imagepscopyfont ( int fontindex)

Use this function if you need make further modifications to the font, for example extending/condensing, slanting it or changing it's character encoding vector, but need to keep the original along as well. Note that the font you want to copy must be one obtained using imagepsloadfont(), not a font that is itself a copied one. You can although make modifications to it before copying.

If you use this function, you must free the fonts obtained this way yourself and in reverse order. Otherwise your script will hang.

In the case everything went right, a valid font index will be returned and can be used for further purposes. Otherwise the function returns FALSE and prints a message describing what went wrong.

imagepsencodefont

(PHP 3>= 3.0.9, PHP 4 )

imagepsencodefont -- Change the character encoding vector of a font

Description

int imagepsencodefont ( int font_index, string encodingfile)

Loads a character encoding vector from from a file and changes the fonts encoding vector to it. As a PostScript fonts default vector lacks most of the character positions above 127, you'll definitely want to change this if you use an other language than english. The exact format of this file is described in T1libs documentation. T1lib comes with two ready-to-use files, IsoLatin1.enc and IsoLatin2.enc.

If you find yourself using this function all the time, a much better way to define the encoding is to set ps.default_encoding in the configuration file to point to the right encoding file and all fonts you load will automatically have the right encoding.

imagepsextendfont

(PHP 3>= 3.0.9, PHP 4 )

imagepsextendfont -- Extend or condense a font

Description

bool imagepsextendfont ( int font_index, float extend)

Extend or condense a font (font_index), if the value of the extend parameter is less than one you will be condensing the font.

imagepsfreefont

(PHP 3>= 3.0.9, PHP 4 )

imagepsfreefont -- Free memory used by a PostScript Type 1 font

Description

void imagepsfreefont ( int fontindex)

imagepsloadfont

(PHP 3>= 3.0.9, PHP 4 )

imagepsloadfont -- Load a PostScript Type 1 font from file

Description

int imagepsloadfont ( string filename)

In the case everything went right, a valid font index will be returned and can be used for further purposes. Otherwise the function returns FALSE and prints a message describing what went wrong, which you cannot read directly, while the output type is image.

<?php header ("Content-type: image/jpeg"); $im = imagecreate (350, 45); $black = imagecolorallocate ($im, 0, 0, 0); $white = imagecolorallocate ($im, 255, 255, 255); $font = imagepsloadfont ("bchbi.pfb"); // or locate your .pfb files on your machine imagepstext ($im, "Testing... It worked!", $font, 32, $white, $black, 32, 32); imagepsfreefont ($font); imagejpeg ($im, "", 100); //for best quality...your mileage may vary imagedestroy ($im); ?>

imagepsslantfont

(PHP 3>= 3.0.9, PHP 4 )

imagepsslantfont -- Slant a font

Description

bool imagepsslantfont ( int font_index, float slant)

Slant a font given by the font_index parameter with a slant of the value of the slant parameter.

imagepstext

(PHP 3>= 3.0.9, PHP 4 )

imagepstext -- To draw a text string over an image using PostScript Type1 fonts

Description

array imagepstext ( resource image, string text, int font, int size, int foreground, int background, int x, int y [, int space [, int tightness [, float angle [, int antialias_steps]]]])

Size is expressed in pixels.

Foreground is the color in which the text will be painted. Background is the color to which the text will try to fade in with antialiasing. No pixels with the color background are actually painted, so the background image does not need to be of solid color.

The coordinates given by x, y will define the origin (or reference point) of the first character (roughly the lower-left corner of the character). This is different from the imagestring(), where x, y define the upper-right corner of the first character. Refer to PostScipt documentation about fonts and their measuring system if you have trouble understanding how this works.

Space allows you to change the default value of a space in a font. This amount is added to the normal value and can also be negative.

Tightness allows you to control the amount of white space between characters. This amount is added to the normal character width and can also be negative.

Angle is in degrees.

Antialias_steps allows you to control the number of colours used for antialiasing text. Allowed values are 4 and 16. The higher value is recommended for text sizes lower than 20, where the effect in text quality is quite visible. With bigger sizes, use 4. It's less computationally intensive.

Parameters space and tightness are expressed in character space units, where 1 unit is 1/1000th of an em-square.

Parameters space, tightness, angle and antialias are optional.

This function returns an array containing the following elements:

0	lower left x-coordinate
1	lower left y-coordinate
2	upper right x-coordinate
3	upper right y-coordinate

imagerectangle

(PHP 3, PHP 4 )

imagerectangle -- Draw a rectangle

Description

int imagerectangle ( resource image, int x1, int y1, int x2, int y2, int col)

imagerectangle() creates a rectangle of color col in image image starting at upper left coordinate x1, y1 and ending at bottom right coordinate x2, y2. 0, 0 is the top left corner of the image.

imagesetbrush

(PHP 4 >= 4.0.6)

imagesetbrush -- Set the brush image for line drawing

Description

int imagesetbrush ( resource image, resource brush)

imagesetbrush() sets the brush image to be used by all line drawing functions (such as imageline() and imagepolygon()) when drawing with the special colors IMG_COLOR_BRUSHED or IMG_COLOR_STYLEDBRUSHED.

Note: You need not take special action when you are finished with a brush, but if you destroy the brush image, you must not use the IMG_COLOR_BRUSHED or IMG_COLOR_STYLEDBRUSHED colors until you have set a new brush image!

Note: This function was added in PHP 4.0.6

imagesetpixel

(PHP 3, PHP 4 )

imagesetpixel -- Set a single pixel

Description

int imagesetpixel ( resource image, int x, int y, int col)

imagesetpixel() draws a pixel at x, y (top left is 0, 0) in image image of color col.

imagesetstyle

(PHP 4 >= 4.0.6)

imagesetstyle -- Set the style for line drawing

Description

int imagesetstyle ( resource image, array style)

imagesetstyle() sets the style to be used by all line drawing functions (such as imageline() and imagepolygon()) when drawing with the special color IMG_COLOR_STYLED or lines of images with color IMG_COLOR_STYLEDBRUSHED.

The style parameter is an array of pixels. Following example script draws a dashed line from upper left to lower right corner of the canvas:
Example 1. imagesetstyle
<?php header ("Content-type: image/png"); $im = imagecreate (100, 100); $w = imagecolorallocate ($im, 255, 255, 255); $red = imagecolorallocate ($im, 255, 0, 0); /* Draw a dashed line, 5 red pixels, 5 white pixels */ $style = array ($red,$red,$red,$red,$red,$w,$w,$w,$w,$w); imagesetstyle ($im, $style); imageline ($im, 0, 0, 100, 100, IMG_COLOR_STYLED); /* Draw a line of happy faces using imagesetbrush() with imagesetstyle */ $style = array ($w,$w,$w,$w,$w,$w,$w,$w,$w,$w,$w,$w,$red); imagesetstyle ($im, $style); $brush = imagecreatefrompng ("http://www.libpng.org/pub/png/images/smile.happy.png"); imagecolortransparent ($brush, $w); imagesetbrush ($im, $brush); imageline ($im, 100, 0, 0, 100, IMG_COLOR_STYLEDBRUSHED); imagepng ($im); imagedestroy ($im); ?>

Note: This function was added in PHP 4.0.6

imagesetthickness

(PHP 4 >= 4.0.6)

imagesetthickness -- Set the thickness for line drawing

Description

void imagesetthickness ( resource image, int thickness)

imagesetthickness() sets the thickness of the lines drawn when drawing rectangles, polygons, ellipses etc. etc. to thickness pixels.

Note: This function was added in PHP 4.0.6 and requires GD 2.0.1 or later

imagesettile

(PHP 4 >= 4.0.6)

imagesettile -- Set the tile image for filling

Description

int imagesettile ( resource image, resource tile)

imagesettile() sets the tile image to be used by all region filling functions (such as imagefill() and imagefilledpolygon()) when filling with the special color IMG_COLOR_TILED.

A tile is an image used to fill an area with a repeated pattern. Any GD image can be used as a tile, and by setting the transparent color index of the tile image with imagecolortransparent(), a tile allows certain parts of the underlying area to shine through can be created.

Note: You need not take special action when you are finished with a tile, but if you destroy the tile image, you must not use the IMG_COLOR_TILED color until you have set a new tile image!

Note: This function was added in PHP 4.0.6

ncolors sets the maximum number of colors that should be retained in the palette.

Note: This function was added in PHP 4.0.6 and requires GD 2.0.1 or later

imagettfbbox

(PHP 3>= 3.0.1, PHP 4 )

imagettfbbox -- Give the bounding box of a text using TrueType fonts

Description

array imagettfbbox ( int size, int angle, string fontfile, string text)

This function calculates and returns the bounding box in pixels for a TrueType text.

text: The string to be measured.
size: The font size in pixels.
fontfile: The name of the TrueType font file. (Can also be an URL.) Depending on which version of the GD library that PHP is using, it may attempt to search for files that do not begin with a leading '/' by appending '.ttf' to the filename and searching along a library-defined font path.
angle: Angle in degrees in which text will be measured.

imagettfbbox() returns an array with 8 elements representing four points making the bounding box of the text:

0	lower left corner, X position
1	lower left corner, Y position
2	lower right corner, X position
3	lower right corner, Y position
4	upper right corner, X position
5	upper right corner, Y position
6	upper left corner, X position
7	upper left corner, Y position

The points are relative to the text regardless of the angle, so "upper left" means in the top left-hand corner seeing the text horizontallty.

This function requires both the GD library and the FreeType library.

imagettftext

(PHP 3, PHP 4 )

imagettftext -- Write text to the image using TrueType fonts

Description

array imagettftext ( resource image, int size, int angle, int x, int y, int col, string fontfile, string text)

imagettftext() draws the string text in the image identified by image, starting at coordinates x, y (top left is 0, 0), at an angle of angle in color col, using the TrueType font file identified by fontfile. Depending on which version of the GD library that PHP is using, when fontfile does not begin with a leading '/', '.ttf' will be appended to the filename and the the library will attempt to search for that filename along a library-defined font path.

The coordinates given by x, y will define the basepoint of the first character (roughly the lower-left corner of the character). This is different from the imagestring(), where x, y define the upper-right corner of the first character.

Angle is in degrees, with 0 degrees being left-to-right reading text (3 o'clock direction), and higher values representing a counter-clockwise rotation. (i.e., a value of 90 would result in bottom-to-top reading text).

Fontfile is the path to the TrueType font you wish to use.

Text is the text string which may include UTF-8 character sequences (of the form: {) to access characters in a font beyond the first 255.

Col is the color index. Using the negative of a color index has the effect of turning off antialiasing.

imagettftext() returns an array with 8 elements representing four points making the bounding box of the text. The order of the points is lower left, lower right, upper right, upper left. The points are relative to the text regardless of the angle, so "upper left" means in the top left-hand corner when you see the text horizontallty.

This example script will produce a black GIF 400x30 pixels, with the words "Testing..." in white in the font Arial.
Example 1. imagettftext
<?php header ("Content-type: image/gif"); $im = imagecreate (400, 30); $black = imagecolorallocate ($im, 0, 0, 0); $white = imagecolorallocate ($im, 255, 255, 255); imagettftext ($im, 20, 0, 10, 20, $white, "/path/arial.ttf", "Testing...Omega: Ω"); imagegif ($im); imagedestroy ($im); ?>

This function requires both the GD library and the FreeType library.

imagetypes

(PHP 3 CVS only, PHP 4 >= 4.0.2)

imagetypes -- Return the image types supported by this PHP build

Description

int imagetypes ( void)

This function returns a bit-field corresponding to the image formats supported by the version of GD linked into PHP. The following bits are returned, IMG_GIF | IMG_JPG | IMG_PNG | IMG_WBMP. To check for PNG support, for example, do this:
Example 1. imagetypes
<?php if (imagetypes() & IMG_PNG) { echo "PNG Support is enabled"; } ?>

imagewbmp

(PHP 3>= 3.0.15, PHP 4 >= 4.0.1)

imagewbmp -- Output image to browser or file

Description

int imagewbmp ( resource image [, string filename [, int foreground]])

imagewbmp() creates the WBMP file in filename from the image image. The image argument is the return from the imagecreate() function.

Note: WBMP support is only available if PHP was compiled against GD-1.8 or later.

Using the optional foreground parameter, you can set the foreground color. Use an identifier obtained from imagecolorallocate(). The default foreground color is black.

iptcembed

(PHP 3>= 3.0.7, PHP 4 )

iptcembed -- Embed binary IPTC data into a JPEG image

Description

array iptcembed ( string iptcdata, string jpeg_file_name [, int spool])

Warning

This function is currently not documented; only the argument list is available.

iptcparse

(PHP 3>= 3.0.6, PHP 4 )

iptcparse -- Parse a binary IPTC http://www.iptc.org/ block into single tags.

Description

Note: The read_exif_data() function is an alias for exif_read_data().

XLII. IMAP, POP3 and NNTP functions

Introduction

These functions are not limited to the IMAP protocol, despite their name. The underlying c-client library also supports NNTP, POP3 and local mailbox access methods.

Requirements

This extension requires the c-client library to be installed. Grab the latest version from ftp://ftp.cac.washington.edu/imap/ and compile it.

You have to copy some files to make sure they are in your link path (e.g.: /usr/local/lib/) and include directory (e.g.: /usr/local/include). The files to copy can be found in the source tree under imap-200x/c-lient after a succesfull run of make. Copy c-client.a to /usr/local/lib/libc-client.a or some other directory on your link path.

Note: Make sure c-client.a ends up in your link path under the name libc-client.a.

Copy the following files to /usr/local/include or some other directory in your include path.

c-client.h

imap4r1.h

rfc822.h

mail.h

linkage.h

env.h

env_unix.h

fs.h

ftl.h

misc.h

nntp.h

nl.h

osdep.h

smtp.h

tcp.h

Note: The name of env_unix.h depends on your OS. Make sure to copy this files with following symlinks option. To build the c-client library with SSL or/and Kerberos support read the docs supplied with the package.

Installation

To get these functions to work, you have to compile PHP with --with-imap.

Note: Depending how the c-client was configured, you might also need to add --with-imap-ssl=/path/to/openssl/ and/or --with-kerberos into the PHP configure line.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

NIL (integer)
OP_DEBUG (integer)
OP_READONLY (integer)
OP_ANONYMOUS (integer)
OP_SHORTCACHE (integer)
OP_SILENT (integer)
OP_PROTOTYPE (integer)
OP_HALFOPEN (integer)
OP_EXPUNGE (integer)
OP_SECURE (integer)
CL_EXPUNGE (integer)
FT_UID (integer)
FT_PEEK (integer)
FT_NOT (integer)
FT_INTERNAL (integer)
FT_PREFETCHTEXT (integer)
ST_UID (integer)
ST_SILENT (integer)
ST_SET (integer)
CP_UID (integer)
CP_MOVE (integer)
SE_UID (integer)
SE_FREE (integer)
SE_NOPREFETCH (integer)
SO_FREE (integer)
SO_NOSERVER (integer)
SA_MESSAGES (integer)
SA_RECENT (integer)
SA_UNSEEN (integer)
SA_UIDNEXT (integer)
SA_UIDVALIDITY (integer)
SA_ALL (integer)
LATT_NOINFERIORS (integer)
LATT_NOSELECT (integer)
LATT_MARKED (integer)
LATT_UNMARKED (integer)
SORTDATE (integer)
SORTARRIVAL (integer)
SORTFROM (integer)
SORTSUBJECT (integer)
SORTTO (integer)
SORTCC (integer)
SORTSIZE (integer)
TYPETEXT (integer)
TYPEMULTIPART (integer)
TYPEMESSAGE (integer)
TYPEAPPLICATION (integer)
TYPEAUDIO (integer)
TYPEIMAGE (integer)
TYPEVIDEO (integer)
TYPEOTHER (integer)
ENC7BIT (integer)
ENC8BIT (integer)
ENCBINARY (integer)
ENCBASE64 (integer)
ENCQUOTEDPRINTABLE (integer)
ENCOTHER (integer)

imap_8bit

(PHP 3, PHP 4 )

imap_8bit -- Convert an 8bit string to a quoted-printable string

Description

string imap_8bit ( string string)

string imap_binary ( string string)

Convert an 8bit string to a base64 string (according to RFC2045, Section 6.8).

Returns a base64 string.

imap_body

(PHP 3, PHP 4 )

imap_body -- Read the message body

Description

string imap_body ( resource imap_stream, int msg_number [, int options])

imap_body() returns the body of the message, numbered msg_number in the current mailbox. The optional flags are a bit mask with one or more of the following:

FT_UID - The msgno is a UID
FT_PEEK - Do not set the \Seen flag if not already set
FT_INTERNAL - The return string is in internal format, will not canonicalize to CRLF.

imap_body() will only return a verbatim copy of the message body. To extract single parts of a multipart MIME-encoded message you have to use imap_fetchstructure() to analyze its structure and imap_fetchbody() to extract a copy of a single body component.

imap_bodystruct

(PHP 3>= 3.0.4, PHP 4 )

imap_bodystruct -- Read the structure of a specified body section of a specific message

Description

bool imap_deletemailbox ( resource imap_stream, string mbox)

imap_deletemailbox() deletes the specified mailbox (see imap_open() for the format of mbox names).

Returns TRUE on success and FALSE on error.

See also imap_createmailbox(), imap_renamemailbox(), and imap_open() for the format of mbox.

imap_errors

(PHP 3>= 3.0.12, PHP 4 )

imap_errors -- This function returns all of the IMAP errors (if any) that have occurred during this page request or since the error stack was reset.

Description

array imap_errors ( void)

This function returns an array of all of the IMAP error messages generated since the last imap_errors() call, or the beginning of the page. When imap_errors() is called, the error stack is subsequently cleared.

imap_expunge

(PHP 3, PHP 4 )

imap_expunge -- Delete all messages marked for deletion

Description

This function fetches all the structured information for a given message. The optional flags parameter only has a single option, FT_UID, which tells the function to treat the msg_number argument as a UID. The returned object includes the envelope, internal date, size, flags and body structure along with a similar object for each mime attachement. The structure of the returned objects is as follows:

Table 1. Returned Objects for imap_fetchstructure()

type	Primary body type
encoding	Body transfer encoding
ifsubtype	`TRUE` if there is a subtype string
subtype	MIME subtype
ifdescription	`TRUE` if there is a description string
description	Content description string
ifid	`TRUE` if there is an identification string
id	Identification string
lines	Number of lines
bytes	Number of bytes
ifdisposition	`TRUE` if there is a disposition string
disposition	Disposition string
ifdparameters	`TRUE` if the dparameters array exists
dparameters	An array of objects where each object has an "attribute" and a "value" property corresponding to the parameters on the Content-disposition MIMEheader.
ifparameters	`TRUE` if the parameters array exists
parameters	An array of objects where each object has an "attribute" and a "value" property.
parts	An array of objects identical in structure to the top-level object, each of which corresponds to a MIME body part.

Table 2. Primary body type

0	text
1	multipart
2	message
3	application
4	audio
5	image
6	video
7	other

Table 3. Transfer encodings

0	7BIT
1	8BIT
2	BINARY
3	BASE64
4	QUOTED-PRINTABLE
5	OTHER

imap_get_quota

(PHP 4 >= 4.0.5)

imap_get_quota -- Retrieve the quota level settings, and usage statics per mailbox

Description

array imap_get_quota ( resource imap_stream, string quota_root)

Returns an array with integer values limit and usage for the given mailbox. The value of limit represents the total amount of space allowed for this mailbox. The usage value represents the mailboxes current level of capacity. Will return FALSE in the case of failure.

This function is currently only available to users of the c-client2000 or greater library.

NOTE: For this function to work, the mail stream is required to be opened as the mail-admin user. For a non-admin user version of this function, please see the imap_get_quotaroot() function of PHP.

imap_stream should be the value returned from an imap_open() call. NOTE: This stream is required to be opened as the mail admin user for the get_quota function to work. quota_root should normally be in the form of user.name where name is the mailbox you wish to retrieve information about.

Example 1. imap_get_quota() example
$mbox = imap_open("{your.imap.host}","mailadmin","password",OP_HALFOPEN) or die("can't connect: ".imap_last_error()); $quota_value = imap_get_quota($mbox, "user.kalowsky"); if(is_array($quota_value)) { print "Usage level is: " . $quota_value['usage']; print "Limit level is: " . $quota_value['limit']; } imap_close($mbox);

As of PHP version 4.3, the function more properly reflects the functionality as dictated by the RFC 2087. The array return value has changed to support an unlimited number of returned resources (i.e. messages, or sub-folders) with each named resource receiving an individual array key. Each key value then contains an another array with the usage and limit values within it. The example below shows the updated returned output.

For backwards compatibility reasons, the originial access methods are still available for use, although it is suggested to update.

Example 2. imap_get_quota() 4.3 or greater example
$mbox = imap_open("{your.imap.host}","mailadmin","password",OP_HALFOPEN) or die("can't connect: ".imap_last_error()); $quota_values = imap_get_quota($mbox, "user.kalowsky"); if(is_array($quota_values)) { $storage = $quota_values['STORAGE']; print "STORAGE usage level is: " . $storage['usage']; print "STORAGE limit level is: " . $storage['limit']; $message = $quota_values['MESSAGE']; print "MESSAGE usage level is: " . $message['usage']; print "MESSAGE usage level is: " . $message['limit']; /* ... */ } imap_close($mbox);

imap_get_quotaroot

(PHP 4 CVS only)

imap_get_quotaroot -- Retrieve the quota settings per user

Description

array imap_get_quotaroot ( resource imap_stream, string quota_root)

Returns an array of integer values pertaining to the specified user mailbox. All values contain a key based upon the resource name, and a corresponding array with the usage and limit values within.

The limit value represents the total amount of space allowed for this user's total mailbox usage. The usage value represents the user's current total mailbox capacity. This function will return FALSE in the case of call failure, and an array of information about the connection upon an un-parsable response from the server.

This function is currently only available to users of the c-client2000 or greater library.

imap_stream should be the value returned from an imap_open() call. This stream should be opened as the user whose mailbox you wish to check. quota_root should normally be in the form of which mailbox (i.e. INBOX).

Example 1. imap_get_quotaroot() example
$mbox = imap_open("{your.imap.host}","kalowsky","password",OP_HALFOPEN) or die("can't connect: ".imap_last_error()); $quota = imap_get_quotaroot($mbox, "INBOX"); if(is_array($quota)) { $storage = $quota_values['STORAGE']; print "STORAGE usage level is: " . $storage['usage']; print "STORAGE limit level is: " . $storage['limit']; $message = $quota_values['MESSAGE']; print "MESSAGE usage level is: " . $message['usage']; print "MESSAGE usage level is: " . $message['limit']; /* ... */ } imap_close($mbox);

imap_getmailboxes

(PHP 3>= 3.0.12, PHP 4 )

imap_getmailboxes -- Read the list of mailboxes, returning detailed information on each one

Description

array imap_getmailboxes ( resource imap_stream, string ref, string pattern)

Returns an array of objects containing mailbox information. Each object has the attributes name, specifying the full name of the mailbox; delimiter, which is the hierarchy delimiter for the part of the hierarchy this mailbox is in; and attributes. Attributes is a bitmask that can be tested against:

LATT_NOINFERIORS - This mailbox has no "children" (there are no mailboxes below this one).
LATT_NOSELECT - This is only a container, not a mailbox - you cannot open it.
LATT_MARKED - This mailbox is marked. Only used by UW-IMAPD.
LATT_UNMARKED - This mailbox is not marked. Only used by UW-IMAPD.

Mailbox names containing international Characters outside the printable ASCII range will be encoded and may be decoded by imap_utf7_decode().

ref should normally be just the server specification as described in imap_open(), and pattern specifies where in the mailbox hierarchy to start searching. If you want all mailboxes, pass '*' for pattern.

object imap_headerinfo ( resource imap_stream, int msg_number [, int fromlength [, int subjectlength [, string defaulthost]]])

array imap_list ( resource imap_stream, string ref, string pattern)

bool imap_mail_copy ( resource imap_stream, string msglist, string mbox [, int options])

Returns TRUE on success and FALSE on error.

Copies mail messages specified by msglist to specified mailbox. msglist is a range not just message numbers (as described in RFC2060).

Flags is a bitmask of one or more of

CP_UID - the sequence numbers contain UIDS
CP_MOVE - Delete the messages from the current mailbox after copying

imap_mail_move

(PHP 3, PHP 4 )

imap_mail_move -- Move specified messages to a mailbox

Description

bool imap_mail_move ( resource imap_stream, string msglist, string mbox [, int options])

Returns TRUE on success and FALSE on error.

Moves mail messages specified by msglist to specified mailbox. msglist is a range not just message numbers (as described in RFC2060).

Flags is a bitmask and may contain the single option

CP_UID - the sequence numbers contain UIDS

imap_mail

(PHP 3>= 3.0.14, PHP 4 )

imap_mail -- Send an email message

Description

string imap_mail ( string to, string subject, string message [, string additional_headers [, string cc [, string bcc [, string rpath]]]])

This function allows sending of emails with correct handling of Cc and Bcc receivers. The parameters to, cc and bcc are all strings and are all parsed as rfc822 address lists. The receivers specified in bcc will get the mail, but are excluded from the headers. Use the rpath parameter to specify return path. This is useful when using php as a mail client for multiple users.

imap_mailboxmsginfo

(PHP 3>= 3.0.2, PHP 4 )

imap_mailboxmsginfo -- Get information about the current mailbox

Description

object imap_mailboxmsginfo ( resource imap_stream)

Returns information about the current mailbox. Returns FALSE on failure.

The imap_mailboxmsginfo() function checks the current mailbox status on the server. It is similar to imap_status(), but will additionally sum up the size of all messages in the mailbox, which will take some additional time to execute. It returns the information in an object with following properties.

Table 1. Mailbox properties

Date	date of last change
Driver	driver
Mailbox	name of the mailbox
Nmsgs	number of messages
Recent	number of recent messages
Unread	number of unread messages
Deleted	number of deleted messages
Size	mailbox size

Example 1. imap_mailboxmsginfo() example
<?php $mbox = imap_open("{your.imap.host}INBOX","username", "password") or die("can't connect: ".imap_last_error()); $check = imap_mailboxmsginfo($mbox); if($check) { print "Date: " . $check->Date ."<br>\n" ; print "Driver: " . $check->Driver ."<br>\n" ; print "Mailbox: " . $check->Mailbox ."<br>\n" ; print "Messages: ". $check->Nmsgs ."<br>\n" ; print "Recent: " . $check->Recent ."<br>\n" ; print "Unread: " . $check->Unread ."<br>\n" ; print "Deleted: " . $check->Deleted ."<br>\n" ; print "Size: " . $check->Size ."<br>\n" ; } else { print "imap_check() failed: ".imap_last_error(). "<br>\n"; } imap_close($mbox); ?>

imap_mime_header_decode

(PHP 3>= 3.0.17, PHP 4 )

imap_mime_header_decode -- Decode MIME header elements

Description

array imap_mime_header_decode ( string text)

imap_mime_header_decode() function decodes MIME message header extensions that are non ASCII text (see RFC2047) The decoded elements are returned in an array of objects, where each object has two properties, "charset" & "text". If the element hasn't been encoded, and in other words is in plain US-ASCII,the "charset" property of that element is set to "default".

int imap_num_recent ( resource imap_stream)

Returns the number of recent messages in the current mailbox.

See also: imap_num_msg() and imap_status().

imap_open

(PHP 3, PHP 4 )

imap_open -- Open an IMAP stream to a mailbox

Description

resource imap_open ( string mailbox, string username, string password [, int options])

Returns an IMAP stream on success and FALSE on error. This function can also be used to open streams to POP3 and NNTP servers, but some functions and features are only available on IMAP servers.

A mailbox name consists of a server part and a mailbox path on this server. The special name INBOX stands for the current users personal mailbox. The server part, which is enclosed in '{' and '}', consists of the servers name or ip address, an optional port (prefixed by ':'), and an optional protocol specification (prefixed by '/'). The server part is mandatory in all mailbox parameters. Mailbox names that contain international characters besides those in the printable ASCII space have to be encoded with imap_utf7_encode().

The options are a bit mask with one or more of the following:

OP_READONLY - Open mailbox read-only
OP_ANONYMOUS - Dont use or update a .newsrc for news (NNTP only)
OP_HALFOPEN - For IMAP and NNTP names, open a connection but dont open a mailbox
CL_EXPUNGE - Expunge mailbox automatically upon mailbox close

To connect to an IMAP server running on port 143 on the local machine, do the following:

$mbox = imap_open ("{localhost:143}INBOX", "user_id", "password");

To connect to a POP3 server on port 110 on the local server, use:

$mbox = imap_open ("{localhost:110/pop3}INBOX", "user_id", "password");

To connect to an SSL IMAP or POP3 server, add /ssl after the protocol specification:

$mbox = imap_open ("{localhost:993/imap/ssl}INBOX", "user_id", "password");

To connect to an SSL IMAP or POP3 server with a self-signed certificate, add /ssl/novalidate-cert after the protocol specification:

$mbox = imap_open ("{localhost:995/pop3/ssl/novalidate-cert}", "user_id", "password");

To connect to an NNTP server on port 119 on the local server, use:

$nntp = imap_open ("{localhost:119/nntp}comp.test", "", "");

This function renames on old mailbox to new mailbox (see imap_open() for the format of mbox names).

Returns TRUE on success and FALSE on error.

See also imap_createmailbox(), imap_deletemailbox(), and imap_open() for the format of mbox.

imap_reopen

(PHP 3, PHP 4 )

imap_reopen -- Reopen IMAP stream to new mailbox

Description

bool imap_reopen ( resource imap_stream, string mailbox [, string options])

This function reopens the specified stream to a new mailbox on an IMAP or NNTP server.

The options are a bit mask with one or more of the following:

OP_READONLY - Open mailbox read-only
OP_ANONYMOUS - Dont use or update a .newsrc for news (NNTP only)
OP_HALFOPEN - For IMAP and NNTP names, open a connection but dont open a mailbox.
CL_EXPUNGE - Expunge mailbox automatically upon mailbox close (see also imap_delete() and imap_expunge())

Returns TRUE on success and FALSE on error.

imap_rfc822_parse_adrlist

(PHP 3>= 3.0.2, PHP 4 )

imap_rfc822_parse_adrlist -- Parses an address string

Description

array imap_rfc822_parse_adrlist ( string address, string default_host)

This function parses the address string as defined in RFC2822 and for each address, returns an array of objects. The objects properties are:

mailbox - the mailbox name (username)
host - the host name
personal - the personal name
adl - at domain source route

Example 1. imap_rfc822_parse_adrlist() example
$address_string = "Hartmut Holzgraefe <hartmut@cvs.php.net>, postmaster@somedomain.net, root"; $address_array = imap_rfc822_parse_adrlist($address_string,"somedomain.net"); if(! is_array($address_array)) die("somethings wrong\n"); reset($address_array); while(list($key,$val)=each($address_array)){ print "mailbox : ".$val->mailbox."<br>\n"; print "host : ".$val->host."<br>\n"; print "personal: ".$val->personal."<br>\n"; print "adl : ".$val->adl."<p>\n"; }

imap_rfc822_parse_headers

(PHP 4 )

imap_rfc822_parse_headers -- Parse mail headers from a string

Description

object imap_rfc822_parse_headers ( string headers [, string defaulthost])

This function returns an object of various header elements, similar to imap_header(), except without the flags and other elements that come from the IMAP server.

imap_rfc822_write_address

(PHP 3>= 3.0.2, PHP 4 )

imap_rfc822_write_address -- Returns a properly formatted email address given the mailbox, host, and personal info.

Description

string imap_rfc822_write_address ( string mailbox, string host, string personal)

Returns a properly formatted email address as defined in RFC2822 given the mailbox, host, and personal info.

Example 1. imap_rfc822_write_address() example
print imap_rfc822_write_address("hartmut","cvs.php.net","Hartmut Holzgraefe")."\n";

imap_scanmailbox

(PHP 3, PHP 4 )

imap_scanmailbox -- Read the list of mailboxes, takes a string to search for in the text of the mailbox

Description

array imap_scanmailbox ( resource imap_stream, string ref, string pattern, string content)

This function is an alias to imap_listscan() and is identical to it in every way.

imap_search

(PHP 3>= 3.0.12, PHP 4 )

imap_search -- This function returns an array of messages matching the given search criteria

Description

array imap_search ( resource imap_stream, string criteria, int options)

This function performs a search on the mailbox currently opened in the given imap stream. criteria is a string, delimited by spaces, in which the following keywords are allowed. Any multi-word arguments (eg. FROM "joey smith") must be quoted.

ALL - return all messages matching the rest of the criteria
ANSWERED - match messages with the \\ANSWERED flag set
BCC "string" - match messages with "string" in the Bcc: field
BEFORE "date" - match messages with Date: before "date"
BODY "string" - match messages with "string" in the body of the message
CC "string" - match messages with "string" in the Cc: field
DELETED - match deleted messages
FLAGGED - match messages with the \\FLAGGED (sometimes referred to as Important or Urgent) flag set
FROM "string" - match messages with "string" in the From: field
KEYWORD "string" - match messages with "string" as a keyword
NEW - match new messages
OLD - match old messages
ON "date" - match messages with Date: matching "date"
RECENT - match messages with the \\RECENT flag set
SEEN - match messages that have been read (the \\SEEN flag is set)
SINCE "date" - match messages with Date: after "date"
SUBJECT "string" - match messages with "string" in the Subject:
TEXT "string" - match messages with text "string"
TO "string" - match messages with "string" in the To:
UNANSWERED - match messages that have not been answered
UNDELETED - match messages that are not deleted
UNFLAGGED - match messages that are not flagged
UNKEYWORD "string" - match messages that do not have the keyword "string"
UNSEEN - match messages which have not been read yet

For example, to match all unanswered messages sent by Mom, you'd use: "UNANSWERED FROM mom". Searches appear to be case insensitive. This list of criteria is from a reading of the UW c-client source code and may be uncomplete or inaccurate (see also RFC2060, section 6.4.4).

Valid values for flags are SE_UID, which causes the returned array to contain UIDs instead of messages sequence numbers.

imap_set_quota

(PHP 4 >= 4.0.5)

imap_set_quota -- Sets a quota for a given mailbox

Description

bool imap_set_quota ( resource imap_stream, string quota_root, int quota_limit)

Sets an upper limit quota on a per mailbox basis. This function requires the imap_stream to have been opened as the mail administrator account. It will not work if opened as any other user.

This function is currently only available to users of the c-client2000 or greater library.

imap_stream is the stream pointer returned from a imap_open() call. This stream must be opened as the mail administrator, other wise this function will fail. quota_root is the mailbox to have a quota set. This should follow the IMAP standard format for a mailbox, 'user.name'. quota_limit is the maximum size (in KB) for the quota_root.

Returns TRUE on success and FALSE on error.

Example 1. imap_set_quota() example
$mbox = imap_open ("{your.imap.host:143}", "mailadmin", "password"); if(!imap_set_quota($mbox, "user.kalowsky", 3000)) { print "Error in setting quota\n"; return; } imap_close($mbox);

See also imap_open(), imap_set_quota().

imap_setacl

(PHP 4 >= 4.1.0)

imap_setacl -- Sets the ACL for a giving mailbox

Description

bool imap_setacl ( resource stream_id, string mailbox, string id, string rights)

Warning

This function is currently not documented; only the argument list is available.

imap_setflag_full

(PHP 3>= 3.0.3, PHP 4 )

imap_setflag_full -- Sets flags on messages

Description

bool imap_setflag_full ( resource stream, string sequence, string flag, string options)

This function causes a store to add the specified flag to the flags set for the messages in the specified sequence.

The flags which you can set are "\\Seen", "\\Answered", "\\Flagged", "\\Deleted", and "\\Draft" (as defined by RFC2060).

The options are a bit mask with one or more of the following:

ST_UID          The sequence argument contains UIDs instead of
                sequence numbers

Example 1. imap_setflag_full() example
$mbox = imap_open("{your.imap.host:143}","username","password") or die("can't connect: ".imap_last_error()); $status = imap_setflag_full($mbox,"2,5","\\Seen \\Flagged"); print gettype($status)."\n"; print $status."\n"; imap_close($mbox);

imap_sort

(PHP 3>= 3.0.3, PHP 4 )

imap_sort -- Sort an array of message headers

Description

array imap_sort ( resource stream, int criteria, int reverse [, int options [, string search_criteria]])

Returns an array of message numbers sorted by the given parameters.

Reverse is 1 for reverse-sorting.

Criteria can be one (and only one) of the following:

SORTDATE        message Date
SORTARRIVAL     arrival date
SORTFROM        mailbox in first From address
SORTSUBJECT     message Subject
SORTTO          mailbox in first To address
SORTCC          mailbox in first cc address
SORTSIZE        size of message in octets

The flags are a bitmask of one or more of the following:

SE_UID          Return UIDs instead of sequence numbers
SE_NOPREFETCH   Don't prefetch searched messages.

imap_status

(PHP 3>= 3.0.4, PHP 4 )

imap_status -- This function returns status information on a mailbox other than the current one

Description

object imap_status ( resource imap_stream, string mailbox, int options)

This function returns an object containing status information. Valid flags are:

SA_MESSAGES - set status->messages to the number of messages in the mailbox
SA_RECENT - set status->recent to the number of recent messages in the mailbox
SA_UNSEEN - set status->unseen to the number of unseen (new) messages in the mailbox
SA_UIDNEXT - set status->uidnext to the next uid to be used in the mailbox
SA_UIDVALIDITY - set status->uidvalidity to a constant that changes when uids for the mailbox may no longer be valid
SA_ALL - set all of the above

Converts the given text to UTF8 (as defined in RFC2044).

XLIII. Informix functions

Introduction

The Informix driver for Informix (IDS) 7.x, SE 7.x, Universal Server (IUS) 9.x and IDS 2000 is implemented in "ifx.ec" and "php3_ifx.h" in the informix extension directory. IDS 7.x support is fairly complete, with full support for BYTE and TEXT columns. IUS 9.x support is partly finished: the new data types are there, but SLOB and CLOB support is still under construction.

Requirements

Configuration notes: You need a version of ESQL/C to compile the PHP Informix driver. ESQL/C versions from 7.2x on should be OK. ESQL/C is now part of the Informix Client SDK.
Make sure that the "INFORMIXDIR" variable has been set, and that $INFORMIXDIR/bin is in your PATH before you run the "configure" script.

Installation

Note: The configure script will autodetect the libraries and include directories, if you run configure --with_informix=yes. You can override this detection by specifying "IFX_LIBDIR", "IFX_LIBS" and "IFX_INCDIR" in the environment. The configure script will also try to detect your Informix server version. It will set the "HAVE_IFX_IUS" conditional compilation variable if your Informix version >= 9.00.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Note: Make sure that the Informix environment variables INFORMIXDIR and INFORMIXSERVER are available to the PHP ifx driver, and that the INFORMIX bin directory is in the PATH. Check this by running a script that contains a call to phpinfo() before you start testing. The phpinfo() output should list these environment variables. This is TRUE for both CGI php and Apache mod_php. You may have to set these environment variables in your Apache startup script.
The Informix shared libraries should also be available to the loader (check LD_LIBRARY_PATH or ld.so.conf/ldconfig).

Some notes on the use of BLOBs (TEXT and BYTE columns): BLOBs are normally addressed by BLOB identifiers. Select queries return a "blob id" for every BYTE and TEXT column. You can get at the contents with "string_var = ifx_get_blob($blob_id);" if you choose to get the BLOBs in memory (with : "ifx_blobinfile(0);"). If you prefer to receive the content of BLOB columns in a file, use "ifx_blobinfile(1);", and "ifx_get_blob($blob_id);" will get you the filename. Use normal file I/O to get at the blob contents.
For insert/update queries you must create these "blob id's" yourself with "ifx_create_blob();". You then plug the blob id's into an array, and replace the blob columns with a question mark (?) in the query string. For updates/inserts, you are responsible for setting the blob contents with ifx_update_blob().
The behaviour of BLOB columns can be altered by configuration variables that also can be set at runtime :
configuration variable : ifx.textasvarchar
configuration variable : ifx.byteasvarchar
runtime functions :
ifx_textasvarchar(0) : use blob id's for select queries with TEXT columns
ifx_byteasvarchar(0) : use blob id's for select queries with BYTE columns
ifx_textasvarchar(1) : return TEXT columns as if they were VARCHAR columns, so that you don't need to use blob id's for select queries.
ifx_byteasvarchar(1) : return BYTE columns as if they were VARCHAR columns, so that you don't need to use blob id's for select queries.
configuration variable : ifx.blobinfile
runtime function :
ifx_blobinfile_mode(0) : return BYTE columns in memory, the blob id lets you get at the contents.
ifx_blobinfile_mode(1) : return BYTE columns in a file, the blob id lets you get at the file name.
If you set ifx_text/byteasvarchar to 1, you can use TEXT and BYTE columns in select queries just like normal (but rather long) VARCHAR fields. Since all strings are "counted" in PHP, this remains "binary safe". It is up to you to handle this correctly. The returned data can contain anything, you are responsible for the contents.
If you set ifx_blobinfile to 1, use the file name returned by ifx_get_blob(..) to get at the blob contents. Note that in this case YOU ARE RESPONSIBLE FOR DELETING THE TEMPORARY FILES CREATED BY INFORMIX when fetching the row. Every new row fetched will create new temporary files for every BYTE column.
The location of the temporary files can be influenced by the environment variable "blobdir", default is "." (the current directory). Something like : putenv(blobdir=tmpblob"); will ease the cleaning up of temp files accidentally left behind (their names all start with "blb").

Automatically trimming "char" (SQLCHAR and SQLNCHAR) data: This can be set with the configuration variable
ifx.charasvarchar : if set to 1 trailing spaces will be automatically trimmed, to save you some "chopping".

NULL values: The configuration variable ifx.nullformat (and the runtime function ifx_nullformat()) when set to TRUE will return NULL columns as the string "NULL", when set to FALSE they return the empty string. This allows you to discriminate between NULL columns and empty columns.

Table 1. Informix configuration options

Name	Default	Changeable
ifx.allow_persistent	"1"	PHP_INI_SYSTEM
ifx.max_persistent	"-1"	PHP_INI_SYSTEM
ifx.max_links	"-1"	PHP_INI_SYSTEM
ifx.default_host	NULL	PHP_INI_SYSTEM
ifx.default_user	NULL	PHP_INI_SYSTEM
ifx.default_password	NULL	PHP_INI_SYSTEM
ifx.blobinfile	"1"	PHP_INI_ALL
ifx.textasvarchar	"0"	PHP_INI_ALL
ifx.byteasvarchar	"0"	PHP_INI_ALL
ifx.charasvarchar	"0"	PHP_INI_ALL
ifx.nullformat	"0"	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Here is a short explanation of the configuration directives.

ifx.allow_persistent boolean: Whether to allow persistent Informix connections.
ifx.max_persistent integer: The maximum number of persistent Informix connections per process.
ifx.max_links integer: The maximum number of Informix connections per process, including persistent connections.
ifx.default_host string: The default host to connect to when no host is specified in ifx_connect() or ifx_pconnect(). Doesn't apply in safe mode.
ifx.default_user string: The default user id to use when none is specified in ifx_connect() or ifx_pconnect(). Doesn't apply in safe mode.
ifx.default_password string: The default password to use when none is specified in ifx_connect() or ifx_pconnect(). Doesn't apply in safe mode.
ifx.blobinfile boolean: Set to TRUE if you want to return blob columns in a file, FALSE if you want them in memory. You can override the setting at runtime with ifx_blobinfile_mode().
ifx.textasvarchar boolean: Set to TRUE if you want to return TEXT columns as normal strings in select statements, FALSE if you want to use blob id parameters. You can override the setting at runtime with ifx_textasvarchar().
ifx.byteasvarchar boolean: Set to TRUE if you want to return BYTE columns as normal strings in select queries, FALSE if you want to use blob id parameters. You can override the setting at runtime with ifx_textasvarchar().
ifx.charasvarchar boolean: Set to TRUE if you want to trim trailing spaces from CHAR columns when fetching them.
ifx.nullformat boolean: Set to TRUE if you want to return NULL columns as the literal string "NULL", FALSE if you want them returned as the empty string "". You can override this setting at runtime with ifx_nullformat().

Resource Types

Predefined Constants

This extension has no constants defined.

Table of Contents
ifx_affected_rows -- Get number of rows affected by a query
ifx_blobinfile_mode -- Set the default blob mode for all select queries
ifx_byteasvarchar -- Set the default byte mode
ifx_close -- Close Informix connection
ifx_connect -- Open Informix server connection
ifx_copy_blob -- Duplicates the given blob object
ifx_create_blob -- Creates an blob object
ifx_create_char -- Creates an char object
ifx_do -- Execute a previously prepared SQL-statement
ifx_error -- Returns error code of last Informix call
ifx_errormsg -- Returns error message of last Informix call
ifx_fetch_row -- Get row as enumerated array
ifx_fieldproperties -- List of SQL fieldproperties
ifx_fieldtypes -- List of Informix SQL fields
ifx_free_blob -- Deletes the blob object
ifx_free_char -- Deletes the char object
ifx_free_result -- Releases resources for the query
ifx_get_blob -- Return the content of a blob object
ifx_get_char -- Return the content of the char object
ifx_getsqlca -- Get the contents of sqlca.sqlerrd[0..5] after a query
ifx_htmltbl_result -- Formats all rows of a query into a HTML table
ifx_nullformat -- Sets the default return value on a fetch row
ifx_num_fields -- Returns the number of columns in the query
ifx_num_rows -- Count the rows already fetched from a query
ifx_pconnect -- Open persistent Informix connection
ifx_prepare -- Prepare an SQL-statement for execution
ifx_query -- Send Informix query
ifx_textasvarchar -- Set the default text mode
ifx_update_blob -- Updates the content of the blob object
ifx_update_char -- Updates the content of the char object
ifxus_close_slob -- Deletes the slob object
ifxus_create_slob -- Creates an slob object and opens it
ifxus_free_slob -- Deletes the slob object
ifxus_open_slob -- Opens an slob object
ifxus_read_slob -- Reads nbytes of the slob object
ifxus_seek_slob -- Sets the current file or seek position
ifxus_tell_slob -- Returns the current file or seek position
ifxus_write_slob -- Writes a string into the slob object

ifx_affected_rows

(PHP 3>= 3.0.3, PHP 4 )

ifx_affected_rows -- Get number of rows affected by a query

Description

int ifx_affected_rows ( int result_id)

result_id is a valid result id returned by ifx_query() or ifx_prepare().

Returns the number of rows affected by a query associated with result_id.

For inserts, updates and deletes the number is the real number (sqlerrd[2]) of affected rows. For selects it is an estimate (sqlerrd[0]). Don't rely on it. The database server can never return the actual number of rows that will be returned by a SELECT because it has not even begun fetching them at this stage (just after the "PREPARE" when the optimizer has determined the query plan).

Useful after ifx_prepare() to limit queries to reasonable result sets.

ifx_blobinfile_mode

(PHP 3>= 3.0.4, PHP 4 )

ifx_blobinfile_mode -- Set the default blob mode for all select queries

Description

void ifx_blobinfile_mode ( int mode)

Set the default blob mode for all select queries. Mode "0" means save Byte-Blobs in memory, and mode "1" means save Byte-Blobs in a file.

ifx_byteasvarchar

ifx_do -- Execute a previously prepared SQL-statement

Description

int ifx_do ( int result_id)

Returns TRUE on success or FALSE on failure.

Executes a previously prepared query or opens a cursor for it.

Does NOT free result_id on error.

Also sets the real number of ifx_affected_rows() for non-select statements for retrieval by ifx_affected_rows()

ifx_error

(PHP 3>= 3.0.3, PHP 4 )

ifx_error -- Returns error code of last Informix call

Description

string ifx_error ( void)

The Informix error codes (SQLSTATE & SQLCODE) formatted as follows :

x [SQLSTATE = aa bbb SQLCODE=cccc]

where x = space : no error

E : error

N : no more data

W : warning

? : undefined

If the "x" character is anything other than space, SQLSTATE and SQLCODE describe the error in more detail.

See the Informix manual for the description of SQLSTATE and SQLCODE

Returns in a string one character describing the general results of a statement and both SQLSTATE and SQLCODE associated with the most recent SQL statement executed. The format of the string is "(char) [SQLSTATE=(two digits) (three digits) SQLCODE=(one digit)]". The first character can be ' ' (space) (success), 'W' (the statement caused some warning), 'E' (an error happened when executing the statement) or 'N' (the statement didn't return any data).

ifx_errormsg

(PHP 3>= 3.0.4, PHP 4 )

ifx_errormsg -- Returns error message of last Informix call

Description

string ifx_errormsg ( [int errorcode])

Returns the Informix error message associated with the most recent Informix error, or, when the optional "errorcode" param is present, the error message corresponding to "errorcode".

ifx_fetch_row

(PHP 3>= 3.0.3, PHP 4 )

ifx_fetch_row -- Get row as enumerated array

Description

array ifx_fetch_row ( int result_id [, mixed position])

Returns an associative array that corresponds to the fetched row, or FALSE if there are no more rows.

Blob columns are returned as integer blob id values for use in ifx_get_blob() unless you have used ifx_textasvarchar(1) or ifx_byteasvarchar(1), in which case blobs are returned as string values. Returns FALSE on error

result_id is a valid resultid returned by ifx_query() or ifx_prepare() (select type queries only!).

position is an optional parameter for a "fetch" operation on "scroll" cursors: "NEXT", "PREVIOUS", "CURRENT", "FIRST", "LAST" or a number. If you specify a number, an "absolute" row fetch is executed. This parameter is optional, and only valid for SCROLL cursors.

ifx_fetch_row() fetches one row of data from the result associated with the specified result identifier. The row is returned as an array. Each result column is stored in an array offset, starting at offset 0, with the column name as key.

Subsequent calls to ifx_fetch_row() would return the next row in the result set, or FALSE if there are no more rows.

Example 1. Informix fetch rows

$rid = ifx_prepare ("select * from emp where name like " . $name,
                     $connid, IFX_SCROLL);
if (! $rid) {
    ... error ...
}
$rowcount = ifx_affected_rows($rid);
if ($rowcount > 1000) {
    printf ("Too many rows in result set (%d)\n<br>", $rowcount);
    die ("Please restrict your query<br>\n");
}
if (! ifx_do ($rid)) {
   ... error ...
}
$row = ifx_fetch_row ($rid, "NEXT");
while (is_array($row)) {
    for(reset($row); $fieldname=key($row); next($row)) {
        $fieldvalue = $row[$fieldname];
        printf ("%s = %s,", $fieldname, $fieldvalue);
    }
    printf("\n<br>");
    $row = ifx_fetch_row ($rid, "NEXT");
}
ifx_free_result ($rid);

ifx_fieldproperties

(PHP 3>= 3.0.3, PHP 4 )

ifx_fieldproperties -- List of SQL fieldproperties

Description

array ifx_fieldproperties ( int result_id)

Returns an associative array with fieldnames as key and the SQL fieldproperties as data for a query with result_id. Returns FALSE on error.

Returns the Informix SQL fieldproperties of every field in the query as an associative array. Properties are encoded as: "SQLTYPE;length;precision;scale;ISNULLABLE" where SQLTYPE = the Informix type like "SQLVCHAR" etc. and ISNULLABLE = "Y" or "N".

Example 1. Informix SQL fieldproperties

$properties = ifx_fieldproperties ($resultid);
if (! isset($properties)) {
  ... error ...
}
for ($i = 0; $i < count($properties); $i++) {
    $fname = key ($properties);
    printf ("%s:\t type =  %s\n", $fname, $properties[$fname]);
    next ($properties);
}

ifx_fieldtypes

(PHP 3>= 3.0.3, PHP 4 )

ifx_fieldtypes -- List of Informix SQL fields

Description

array ifx_fieldtypes ( int result_id)

Returns an associative array with fieldnames as key and the SQL fieldtypes as data for query with result_id. Returns FALSE on error.

Example 1. Fieldnames and SQL fieldtypes

$types = ifx_fieldtypes ($resultid);
if (! isset ($types)) {
  ... error ...
}
for ($i = 0; $i < count($types); $i++) {
    $fname = key($types);
    printf("%s :\t type =  %s\n", $fname, $types[$fname]);
    next($types);
}

Returns a pseudo-row (associative array) with sqlca.sqlerrd[0] ... sqlca.sqlerrd[5] after the query associated with result_id.

For inserts, updates and deletes the values returned are those as set by the server after executing the query. This gives access to the number of affected rows and the serial insert value. For SELECTs the values are those saved after the PREPARE statement. This gives access to the *estimated* number of affected rows. The use of this function saves the overhead of executing a "select dbinfo('sqlca.sqlerrdx')" query, as it retrieves the values that were saved by the ifx driver at the appropriate moment.

Example 1. Retrieve Informix sqlca.sqlerrd[x] values

/* assume the first column of 'sometable' is a serial */
$qid = ifx_query("insert into sometable 
                  values (0, '2nd column', 'another column') ", $connid);
if (! $qid) {
    ... error ...
}
$sqlca = ifx_getsqlca ($qid);
$serial_value = $sqlca["sqlerrd1"];
echo "The serial value of the inserted row is : " . $serial_value<br>\n";

ifx_htmltbl_result

(PHP 3>= 3.0.3, PHP 4 )

ifx_htmltbl_result -- Formats all rows of a query into a HTML table

Description

int ifx_htmltbl_result ( int result_id [, string html_table_options])

Returns the number of rows fetched or FALSE on error.

Formats all rows of the result_id query into a html table. The optional second argument is a string of <table> tag options

Example 1. Informix results as HTML table

$rid = ifx_prepare ("select * from emp where name like " . $name,
                     $connid, IFX_SCROLL);
if (! $rid) {
   ... error ...
}
$rowcount = ifx_affected_rows ($rid);
if ($rowcount > 1000) {
    printf ("Too many rows in result set (%d)\n<br>", $rowcount);
    die ("Please restrict your query<br>\n");
}
if (! ifx_do($rid) {
  ... error ...
}

ifx_htmltbl_result ($rid, "border=\"2\"");

ifx_free_result($rid);

ifx_nullformat

(PHP 3>= 3.0.4, PHP 4 )

ifx_nullformat -- Sets the default return value on a fetch row

Description

void ifx_nullformat ( int mode)

Sets the default return value of a NULL-value on a fetch row. Mode "0" returns "", and mode "1" returns "NULL".

ifx_num_fields

(PHP 3>= 3.0.3, PHP 4 )

ifx_num_fields -- Returns the number of columns in the query

Description

int ifx_num_fields ( int result_id)

Returns the number of columns in query for result_id or FALSE on error

After preparing or executing a query, this call gives you the number of columns in the query.

ifx_num_rows

(PHP 3>= 3.0.3, PHP 4 )

ifx_num_rows -- Count the rows already fetched from a query

Description

int ifx_num_rows ( int result_id)

Gives the number of rows fetched so far for a query with result_id after a ifx_query() or ifx_do() query.

ifx_pconnect

(PHP 3>= 3.0.3, PHP 4 )

ifx_pconnect -- Open persistent Informix connection

Description

int ifx_pconnect ( [string database [, string userid [, string password]]])

Returns: A positive Informix persistent link identifier on success, or FALSE on error

ifx_pconnect() acts very much like ifx_connect() with two major differences.

This function behaves exactly like ifx_connect() when PHP is not running as an Apache module. First, when connecting, the function would first try to find a (persistent) link that's already open with the same host, username and password. If one is found, an identifier for it will be returned instead of opening a new connection.

Second, the connection to the SQL server will not be closed when the execution of the script ends. Instead, the link will remain open for future use (ifx_close() will not close links established by ifx_pconnect()).

This type of links is therefore called 'persistent'.

ifx_prepare

(PHP 3>= 3.0.4, PHP 4 )

ifx_prepare -- Prepare an SQL-statement for execution

Description

int ifx_prepare ( string query, int conn_id [, int cursor_def, mixed blobidarray])

Returns a integer result_id for use by ifx_do(). Sets affected_rows for retrieval by the ifx_affected_rows() function.

Introduction

InterBase is a popular database put out by Borland/Inprise. More information about InterBase is available at http://www.interbase.com/. Oh, by the way, InterBase just joined the open source movement!

Note: Full support for InterBase 6 was added in PHP 4.0.
This database uses a single quote (') character for escaping, a behavior similar to the Sybase database, add to your php.ini the following directive:
magic_quotes_sybase = On

Requirements

Installation

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. InterBase configuration options

Name	Default	Changeable
ibase.allow_persistent	"1"	PHP_INI_SYSTEM
ibase.max_persistent	"-1"	PHP_INI_SYSTEM
ibase.max_links	"-1"	PHP_INI_SYSTEM
ibase.default_user	NULL	PHP_INI_ALL
ibase.default_password	NULL	PHP_INI_ALL
ibase.timestampformat	"%m/%d/%Y%H:%M:%S"	PHP_INI_ALL
ibase.dateformat	"%m/%d/%Y"	PHP_INI_ALL
ibase.timeformat	"%H:%M:%S"	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Resource Types

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

IBASE_DEFAULT (integer)
IBASE_TEXT (integer)
IBASE_UNIXTIME (integer)
IBASE_READ (integer)
IBASE_COMMITTED (integer)
IBASE_CONSISTENCY (integer)
IBASE_NOWAIT (integer)
IBASE_TIMESTAMP (integer)
IBASE_DATE (integer)
IBASE_TIME (integer)

Table of Contents
ibase_blob_add -- Add data into created blob
ibase_blob_cancel -- Cancel creating blob
ibase_blob_close -- Close blob
ibase_blob_create -- Create blob for adding data
ibase_blob_echo -- Output blob contents to browser
ibase_blob_get -- Get len bytes data from open blob
ibase_blob_import -- Create blob, copy file in it, and close it
ibase_blob_info -- Return blob length and other useful info
ibase_blob_open -- Open blob for retrieving data parts
ibase_close -- Close a connection to an InterBase database
ibase_commit -- Commit a transaction
ibase_connect -- Open a connection to an InterBase database
ibase_errmsg -- Returns error messages
ibase_execute -- Execute a previously prepared query
ibase_fetch_object -- Get an object from a InterBase database
ibase_fetch_row -- Fetch a row from an InterBase database
ibase_field_info -- Get information about a field
ibase_free_query -- Free memory allocated by a prepared query
ibase_free_result -- Free a result set
ibase_num_fields -- Get the number of fields in a result set
ibase_pconnect -- Creates an persistent connection to an InterBase database
ibase_prepare -- Prepare a query for later binding of parameter placeholders and execution
ibase_query -- Execute a query on an InterBase database
ibase_rollback -- Rolls back a transaction
ibase_timefmt -- Sets the format of timestamp, date and time type columns returned from queries
ibase_trans -- Begin a transaction

(PHP 3>= 3.0.7, PHP 4 )

ibase_commit -- Commit a transaction

Description

int ibase_commit ( [int link_identifier, int trans_number])

Commits transaction trans_number which was created with ibase_trans().

ibase_connect

(PHP 3>= 3.0.6, PHP 4 )

ibase_connect -- Open a connection to an InterBase database

Description

int ibase_connect ( string database [, string username [, string password [, string charset [, int buffers [, int dialect [, string role]]]]]])

Establishes a connection to an InterBase server. The database argument has to be a valid path to database file on the server it resides on. If the server is not local, it must be prefixed with either 'hostname:' (TCP/IP), '//hostname/' (NetBEUI) or 'hostname@' (IPX/SPX), depending on the connection protocol used. username and password can also be specified with PHP configuration directives ibase.default_user and ibase.default_password. charset is the default character set for a database. buffers is the number of database buffers to allocate for the server-side cache. If 0 or omitted, server chooses its own default. dialect selects the default SQL dialect for any statement executed within a connection, and it defaults to the highest one supported by client libraries.

In case a second call is made to ibase_connect() with the same arguments, no new link will be established, but instead, the link identifier of the already opened link will be returned. The link to the server will be closed as soon as the execution of the script ends, unless it's closed earlier by explicitly calling ibase_close().
Example 1. ibase_connect() example
<?php $dbh = ibase_connect($host, $username, $password); $stmt = 'SELECT * FROM tblname'; $sth = ibase_query($dbh, $stmt); while ($row = ibase_fetch_object($sth)) { echo $row->email, "\n"; } ibase_free_result($sth); ibase_close($dbh); ?>

Note: buffers was added in PHP 4.0RC2.

Note: dialect was added in PHP 4.0RC2. It is functional only with InterBase 6 and versions higher than that.

Note: role was added in PHP 4.0RC2. It is functional only with InterBase 5 and versions higher than that.

ibase_errmsg

(PHP 3>= 3.0.7, PHP 4 )

ibase_errmsg -- Returns error messages

Description

string ibase_errmsg ( void)

Returns a string containing an error message.

ibase_execute

(PHP 3>= 3.0.6, PHP 4 )

ibase_execute -- Execute a previously prepared query

Description

int ibase_execute ( int query [, int bind_args])

Execute a query prepared by ibase_prepare(). This is a lot more effective than using ibase_query() if you are repeating a same kind of query several times with only some parameters changing.

<?php
    $updates = array(
        1 => 'Eric',
        5 => 'Filip',
        7 => 'Larry'
    );

    $query = ibase_prepare("UPDATE FOO SET BAR = ? WHERE BAZ = ?");

    while (list($baz, $bar) = each($updates)) {
        ibase_execute($query, $bar, $baz);
    }
?>

ibase_fetch_object

(PHP 3>= 3.0.7, PHP 4 )

ibase_fetch_object -- Get an object from a InterBase database

Description

object ibase_fetch_object ( int result_id)

Fetches a row as a pseudo-object from a result_id obtained either by ibase_query() or ibase_execute().

<php
    $dbh = ibase_connect ($host, $username, $password);
    $stmt = 'SELECT * FROM tblname';
    $sth = ibase_query ($dbh, $stmt);
    while ($row = ibase_fetch_object ($sth)) {
        print $row->email . "\n";
    }
    ibase_close ($dbh);
?>

Subsequent call to ibase_fetch_object() would return the next row in the result set, or FALSE if there are no more rows.

ibase_fetch_row

(PHP 3>= 3.0.6, PHP 4 )

ibase_fetch_row -- Fetch a row from an InterBase database

Description

array ibase_fetch_row ( int result_identifier)

Returns an array that corresponds to the fetched row, or FALSE if there are no more rows.

ibase_fetch_row() fetches one row of data from the result associated with the specified result_identifier. The row is returned as an array. Each result column is stored in an array offset, starting at offset 0.

Subsequent call to ibase_fetch_row() would return the next row in the result set, or FALSE if there are no more rows.

ibase_field_info

(PHP 3>= 3.0.7, PHP 4 )

ibase_field_info -- Get information about a field

Description

array ibase_field_info ( int result, int field number)

Returns an array with information about a field after a select query has been run. The array is in the form of name, alias, relation, length, type.

$rs=ibase_query("SELECT * FROM tablename"); 
$coln = ibase_num_fields($rs);
for ($i=0; $i < $coln; $i++) {
    $col_info = ibase_field_info($rs, $i); 
    echo "name: ".$col_info['name']."\n"; 
    echo "alias: ".$col_info['alias']."\n"; 
    echo "relation: ".$col_info['relation']."\n"; 
    echo "length: ".$col_info['length']."\n"; 
    echo "type: ".$col_info['type']."\n"; 
    }

<?php
       $dbh = ibase_connect ($host, $username, $password);
       $stmt = 'SELECT * FROM tblname';
       $sth = ibase_query ($dbh, $stmt);

       if (ibase_num_fields($sth) > 0) {
       while ($row = ibase_fetch_object ($sth)) {
       print $row->email . "\n";
       }
       } else {
       die ("No Results were found for your query");
       }

       ibase_close ($dbh);
       ?>

ibase_pconnect

(PHP 3>= 3.0.6, PHP 4 )

ibase_pconnect -- Creates an persistent connection to an InterBase database

Description

int ibase_pconnect ( string database [, string username [, string password [, string charset [, int buffers [, int dialect [, string role]]]]]])

ibase_pconnect() acts very much like ibase_connect() with two major differences. First, when connecting, the function will first try to find a (persistent) link that's already opened with the same parameters. If one is found, an identifier for it will be returned instead of opening a new connection. Second, the connection to the InterBase server will not be closed when the execution of the script ends. Instead, the link will remain open for future use (ibase_close() will not close links established by ibase_pconnect()). This type of link is therefore called 'persistent'.

Note: buffers was added in PHP4-RC2.

Note: dialect was added in PHP4-RC2. It is functional only with InterBase 6 and versions higher than that.

Note: role was added in PHP4-RC2. It is functional only with InterBase 5 and versions higher than that.

Sets the format of timestamp, date or time type columns returned from queries. Internally, the columns are formatted by c-function strftime(), so refer to it's documentation regarding to the format of the string. columntype is one of the constants IBASE_TIMESTAMP, IBASE_DATE and IBASE_TIME. If omitted, defaults to IBASE_TIMESTAMP for backwards compatibility.

<?php
       // InterBase 6 TIME-type columns will be returned in
       // the form '05 hours 37 minutes'. 
       ibase_timefmt("%H hours %M minutes", IBASE_TIME);
       ?>

You can also set defaults for these formats with PHP configuration directives ibase.timestampformat, ibase.dateformat and ibase.timeformat.

Note: columntype was added in PHP 4.0. It has any meaning only with InterBase version 6 and higher.

Note: A backwards incompatible change happened in PHP 4.0 when PHP configuration directive ibase.timeformat was renamed to ibase.timestampformat and directives ibase.dateformat and ibase.timeformat were added, so that the names would match better their functionality.

ibase_trans

(PHP 3>= 3.0.7, PHP 4 )

ibase_trans -- Begin a transaction

Description

int ibase_trans ( [int trans_args [, int link_identifier]])

Begins a transaction.

XLV. Ingres II functions

Introduction

These functions allow you to access Ingres II database servers.

Note: If you already used PHP extensions to access other database servers, note that Ingres doesn't allow concurrent queries and/or transaction over one connection, thus you won't find any result or transaction handle in this extension. The result of a query must be treated before sending another query, and a transaction must be commited or rolled back before opening another transaction (which is automaticaly done when sending the first query).

Warning

Requirements

To compile PHP with Ingres support, you need the Open API library and header files included with Ingres II.

Installation

In order to have these functions available, you must compile php with Ingres support by using the --with-ingres option. If the II_SYSTEM environment variable isn't correctly set you may have to use --with-ingres=DIR to specify your Ingres installation directory.

When using this extension with Apache, if Apache does not start and complains with "PHP Fatal error: Unable to start ingres_ii module in Unknown on line 0" then make sure the environement variable II_SYSTEM is correctly set. Adding "export II_SYSTEM="/home/ingres/II" in the script that starts Apache, just before launching httpd, should be fine.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Ingres II configuration options

Name	Default	Changeable
ingres.allow_persistent	"1"	PHP_INI_SYSTEM
ingres.max_persistent	"-1"	PHP_INI_SYSTEM
ingres.max_links	"-1"	PHP_INI_SYSTEM
ingres.default_database	NULL	PHP_INI_ALL
ingres.default_user	NULL	PHP_INI_ALL
ingres.default_password	NULL	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

INGRES_ASSOC (integer)
INGRES_NUM (integer)
INGRES_BOTH (integer)

Table of Contents
ingres_autocommit -- Switch autocommit on or off
ingres_close -- Close an Ingres II database connection
ingres_commit -- Commit a transaction
ingres_connect -- Open a connection to an Ingres II database
ingres_fetch_array -- Fetch a row of result into an array
ingres_fetch_object -- Fetch a row of result into an object.
ingres_fetch_row -- Fetch a row of result into an enumerated array
ingres_field_length -- Get the length of a field
ingres_field_name -- Get the name of a field in a query result.
ingres_field_nullable -- Test if a field is nullable
ingres_field_precision -- Get the precision of a field
ingres_field_scale -- Get the scale of a field
ingres_field_type -- Get the type of a field in a query result
ingres_num_fields -- Get the number of fields returned by the last query
ingres_num_rows -- Get the number of rows affected or returned by the last query
ingres_pconnect -- Open a persistent connection to an Ingres II database
ingres_query -- Send a SQL query to Ingres II
ingres_rollback -- Roll back a transaction

ingres_autocommit

(PHP 4 >= 4.0.2)

ingres_autocommit -- Switch autocommit on or off

resource ingres_connect ( [string database [, string username [, string password]]])

Warning

Returns a Ingres II link resource on success, or FALSE on failure.

ingres_connect() opens a connection with the Ingres database designated by database, which follows the syntax [node_id::]dbname[/svr_class].

If some parameters are missing, ingres_connect() uses the values in php.ini for ingres.default_database, ingres.default_user, and ingres.default_password.

The connection is closed when the script ends or when ingres_close() is called on this link.

All the other ingres functions use the last opened link as a default, so you need to store the returned value only if you use more than one link at a time.

Example 1. ingres_connect() example

<?php
    $link = ingres_connect ("mydb", "user", "pass")
        or die ("Could not connect");
    print ("Connected successfully");
    ingres_close ($link);
?>

Example 2. ingres_connect() example using default link

<?php
    ingres_connect ("mydb", "user", "pass")
        or die ("Could not connect");
    print ("Connected successfully");
    ingres_close ();
?>

ingres_fetch_array

(PHP 4 >= 4.0.2)

ingres_fetch_array -- Fetch a row of result into an array

Description

array ingres_fetch_array ( [int result_type [, resource link]])

Warning

ingres_fetch_array() Returns an array that corresponds to the fetched row, or FALSE if there are no more rows.

This function is an extended version of ingres_fetch_row(). In addition to storing the data in the numeric indices of the result array, it also stores the data in associative indices, using the field names as keys.

ingres_query(select t1.f1 as foo t2.f1 as bar from t1, t2);
$result = ingres_fetch_array();
$foo = $result["foo"];
$bar = $result["bar"];

result_type can be INGRES_NUM for enumerated array, INGRES_ASSOC for associative array, or INGRES_BOTH (default).

Speed-wise, the function is identical to ingres_fetch_object(), and almost as quick as ingres_fetch_row() (the difference is insignificant).

Example 1. ingres_fetch_array() example
<?php ingres_connect ($database, $user, $password); ingres_query ("select * from table"); while ($row = ingres_fetch_array()) { echo $row["user_id"]; # using associative array echo $row["fullname"]; echo $row[1]; # using enumerated array echo $row[2]; } ?>

ingres_fetch_object

(PHP 4 >= 4.0.2)

ingres_fetch_object -- Fetch a row of result into an object.

Description

object ingres_fetch_object ( [int result_type [, resource link]])

Warning

ingres_fetch_object() Returns an object that corresponds to the fetched row, or FALSE if there are no more rows.

This function is similar to ingres_fetch_array(), with one difference - an object is returned, instead of an array. Indirectly, that means that you can only access the data by the field names, and not by their offsets (numbers are illegal property names).

The optional argument result_type is a constant and can take the following values: INGRES_ASSOC, INGRES_NUM, and INGRES_BOTH.

Speed-wise, the function is identical to ingres_fetch_array(), and almost as quick as ingres_fetch_row() (the difference is insignificant).

Example 1. ingres_fetch_object() example
<?php ingres_connect ($database, $user, $password); ingres_query ("select * from table"); while ($row = ingres_fetch_object()) { echo $row->user_id; echo $row->fullname; } ?>

ingres_fetch_row

(PHP 4 >= 4.0.2)

ingres_fetch_row -- Fetch a row of result into an enumerated array

Description

array ingres_fetch_row ( [resource link])

Warning

Returns TRUE on success, or FALSE on failure.

ingres_query() sends the given query to the Ingres server. This query must be a valid SQL query (see the Ingres SQL reference guide)

The query becomes part of the currently open transaction. If there is no open transaction, ingres_query() opens a new transaction. To close the transaction, you can either call ingres_commit() to commit the changes made to the database or ingres_rollback() to cancel these changes. When the script ends, any open transaction is rolled back (by calling ingres_rollback()). You can also use ingres_autocommit() before opening a new transaction to have every SQL query immediatly commited.

Some types of SQL queries can't be sent with this function:

close (see ingres_close())
commit (see ingres_commit())
connect (see ingres_connect())
disconnect (see ingres_close())
get dbevent
prepare to commit
rollback (see ingres_rollback())
savepoint
set autocommit (see ingres_autocommit())
all cursor related queries are unsupported

Example 1. ingres_query() example
<?php ingres_connect ($database, $user, $password); ingres_query ("select * from table"); while ($row = ingres_fetch_row()) { echo $row[1]; echo $row[2]; } ?>

ingres_rollback

(PHP 4 >= 4.0.2)

ingres_rollback -- Roll back a transaction

Description

bool ingres_rollback ( [resource link])

Warning

ingres_rollback() rolls back the currently open transaction, actually canceling all changes made to the database during the transaction.

This closes the transaction. A new one can be open by sending a query with ingres_query().

XLVI. IRC Gateway Functions

Introduction

With ircg you can build powerful, fast and scalable webchat solutions in conjunction with dedicated or public IRC servers.

IRCG runs under tis platforms:

AIX
FreeBSD
HP-UX
Irix
Linux
Solaris
Tru64

Requirements

To install and use IRCG you need the following software:

IRCG-Library from Sascha Schumann.
SGI Static Threads Library
thttpd webserver

Installation

A detailed installation instruction can be found here.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

Predefined Constants

This extension has no constants defined.

Table of Contents
ircg_channel_mode -- Set channel mode flags for user
ircg_disconnect -- Close connection to server
ircg_fetch_error_msg -- Returns the error from previous ircg operation
ircg_get_username -- Get username for connection
ircg_html_encode -- Encodes HTML preserving output
ircg_ignore_add -- Add a user to your ignore list on a server
ircg_ignore_del -- Remove a user from your ignore list on a server
ircg_is_conn_alive -- Check connection status
ircg_join -- Join a channel on a connected server
ircg_kick -- Kick a user out of a channel on server
ircg_lookup_format_messages -- Select a set of format strings for display of IRC messages
ircg_msg -- Send message to channel or user on server
ircg_nick -- Change nickname on server
ircg_nickname_escape -- Encode special characters in nickname to be IRC-compliant
ircg_nickname_unescape -- Decodes encoded nickname
ircg_notice -- Send a notice to a user on server
ircg_part -- Leave a channel on server
ircg_pconnect -- Connect to an IRC server
ircg_register_format_messages -- Register a set of format strings for display of IRC messages
ircg_set_current -- Set current connection for output
ircg_set_file -- Set logfile for connection
ircg_set_on_die -- Set hostaction to be execute when connection dies
ircg_topic -- Set topic for channel on server
ircg_whois -- Query user information for nick on server

ircg_channel_mode

(PHP 4 >= 4.0.5)

ircg_channel_mode -- Set channel mode flags for user

Description

boolean ircg_channel_mode ( resource connection, string channel, string mode_spec, string nick)

Set channel mode flags for channel on server connected to by connection. Mode flags are passed in mode_spec and are applied to the user specified by nick.

Mode flags are set or cleared by specifind a mode character and prepending it with a plus or minus character respectively. E.g. operator mode is granted by '+o' and revoked by '-o' passed as mode_spec.

ircg_disconnect

(PHP 4 >= 4.0.4)

ircg_disconnect -- Close connection to server

Description

boolean ircg_disconnect ( resource connection, string reason)

ircg_disconnect() will close a connection to a server previously established with ircg-pconnect().

ircg_fetch_error_msg

(PHP 4 >= 4.1.0)

ircg_fetch_error_msg -- Returns the error from previous ircg operation

Description

array ircg_fetch_error_msg ( resource connection)

ircg_fetch_error_msg() returns the error from the last called ircg function.

Note: Errorcode is stored in first array element, errortext in second.

ircg_msg() will send the message to a channel or user on the server connected to by connection. A recipient starting with # or & will send the message to a channel, anything else will be interpreted as a username.

Setting the optional parameter suppress to a TRUE value will suppress output of your message to your own connection.

ircg_nick

(PHP 4 >= 4.0.5)

ircg_nick -- Change nickname on server

Description

boolean ircg_nick ( resource connection, string nick)

resource ircg_pconnect ( string username [, string server_ip [, int server_port [, string msg_format [, array ctcp_messages [, array user_settings]]]]])

ircg_pconnect() will try to establish a connection to an IRC server and return a connection resource handle for further use.

The only mandatory parameter is username, this will set your initial nickname on the server. server_ip and server_port are optional and default to 127.0.0.1 and 6667.

Note: For now parameter server_ip will not do any hostname lookups and will only accept IP addresses in numerical form.
Currently ircg_pconnect() always returns a valid handle, even if the connection failed.

You can customize the output of IRC messages and events by selection a format string set previously created with ircg_register_format_messages() by specifing the sets name in msg_format.

ctcp_messages

user_settings

ircg_register_format_messages

(PHP 4 >= 4.0.5)

ircg_register_format_messages -- Register a set of format strings for display of IRC messages

Description

boolean ircg_register_format_messages ( string name, array messages)

With ircg_register_format_messages() you can customize the way your IRC output looks like. You can even register different format string sets and switch between them on the fly with ircg_lookup_format_messages().

Plain channel message
Private message received
Private message sent
Some user leaves channel
Some user enters channel
Some user was kicked from the channel
Topic has been changed
Error
Fatal error
Join list end(?)
Self part(?)
Some user changes his nick
Some user quits his connection
Mass join begin
Mass join element
Mass join end
Whois user
Whois server
Whois idle
Whois channel
Whois end
Voice status change on user
Operator status change on user
Banlist
Banlist end

%f - from
%t - to
%c - channel
%r - plain message
%m - encoded message
%j - js encoded message

1 - mod encode
2 - nickname decode

XLVII. PHP / Java Integration

Introduction

There are two possible ways to bridge PHP and Java: you can either integrate PHP into a Java Servlet environment, which is the more stable and efficient solution, or integrate Java support into PHP. The former is provided by a SAPI module that interfaces with the Servlet server, the latter by this Java extension.

The Java extension provides a simple and effective means for creating and invoking methods on Java objects from PHP. The JVM is created using JNI, and everything runs in-process.

Warning

Requirements

You need a Java VM installed on your machine to use this extension.

Installation

Build instructions for this extension can be found in php4/ext/java/README.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Java configuration options

Name	Default	Changeable
java.class.path	NULL	PHP_INI_ALL
java.home	NULL	PHP_INI_ALL
java.library.path	NULL	PHP_INI_ALL
java.library	JAVALIB	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Examples

Example 1. Java Example
<?php // get instance of Java class java.lang.System in PHP $system = new Java('java.lang.System'); // demonstrate property access print 'Java version='.$system->getProperty('java.version').' <br>'; print 'Java vendor=' .$system->getProperty('java.vendor').' <br>'; print 'OS='.$system->getProperty('os.name').' '. $system->getProperty('os.version').' on '. $system->getProperty('os.arch').' <br>'; // java.util.Date example $formatter = new Java('java.text.SimpleDateFormat', "EEEE, MMMM dd, yyyy 'at' h:mm:ss a zzzz"); print $formatter->format(new Java('java.util.Date')); ?>

Example 2. AWT Example
<?php // This example is only intented to be run as a CGI. $frame = new Java('java.awt.Frame', 'PHP'); $button = new Java('java.awt.Button', 'Hello Java World!'); $frame->add('North', $button); $frame->validate(); $frame->pack(); $frame->visible = True; $thread = new Java('java.lang.Thread'); $thread->sleep(10000); $frame->dispose(); ?>
Notes:

new Java() will create an instance of a class if a suitable constructor is available. If no parameters are passed and the default constructor is useful as it provides access to classes like java.lang.System which expose most of their functionallity through static methods.
Accessing a member of an instance will first look for bean properties then public fields. In other words, print $date.time will first attempt to be resolved as $date.getTime(), then as $date.time.
Both static and instance members can be accessed on an object with the same syntax. Furthermore, if the java object is of type java.lang.Class, then static members of the class (fields and methods) can be accessed.
Exceptions raised result in PHP warnings, and NULL results. The warnings may be eliminated by prefixing the method call with an "@" sign. The following APIs may be used to retrieve and reset the last error:
- java_last_exception_get()
- java_last_exception_clear()
Overload resolution is in general a hard problem given the differences in types between the two languages. The PHP Java extension employs a simple, but fairly effective, metric for determining which overload is the best match.
Additionally, method names in PHP are not case sensitive, potentially increasing the number of overloads to select from.
Once a method is selected, the parameters are cooerced if necessary, possibly with a loss of data (example: double precision floating point numbers will be converted to boolean).
In the tradition of PHP, arrays and hashtables may pretty much be used interchangably. Note that hashtables in PHP may only be indexed by integers or strings; and that arrays of primitive types in Java can not be sparse. Also note that these constructs are passed by value, so may be expensive in terms of memory and time.

Java Servlet SAPI

The Java Servlet SAPI builds upon the mechanism defined by the Java extension to enable the entire PHP processor to be run as a servlet. The primary advanatage of this from a PHP perspective is that web servers which support servlets typically take great care in pooling and reusing JVMs. Build instructions for the Servlet SAPI module can be found in php4/sapi/README. Notes:

While this code is intended to be able to run on any servlet engine, it has only been tested on Apache's Jakarta/tomcat to date. Bug reports, success stories and/or patches required to get this code to run on other engines would be appreciated.
PHP has a habit of changing the working directory. sapi/servlet will eventually change it back, but while PHP is running the servlet engine may not be able to load any classes from the CLASSPATH which are specified using a relative directory syntax, or find the work directory used for administration and JSP compilation tasks.

Table of Contents
java_last_exception_clear -- Clear last Java exception
java_last_exception_get -- Get last Java exception

java_last_exception_clear

(PHP 4 >= 4.0.2)

java_last_exception_clear -- Clear last Java exception

Description

void java_last_exception_clear ( void)

Warning

See java_last_exception_get() for an example.

java_last_exception_get

(PHP 4 >= 4.0.2)

java_last_exception_get -- Get last Java exception

Description

exception java_last_exception_get ( void)

Warning

The following example demonstrates the usage of Java's exception handler from within PHP:
Example 1. Java exception handler
<?php $stack = new Java('java.util.Stack'); $stack->push(1); // This should succeed $result = $stack->pop(); $ex = java_last_exception_get(); if (!$ex) print "$result\n"; // This should fail (error suppressed by @) $result = @$stack->pop(); $ex = java_last_exception_get(); if ($ex) print $ex->toString(); // Clear last exception java_last_exception_clear(); ?>

XLVIII. LDAP functions

Introduction

LDAP is the Lightweight Directory Access Protocol, and is a protocol used to access "Directory Servers". The Directory is a special kind of database that holds information in a tree structure.

The concept is similar to your hard disk directory structure, except that in this context, the root directory is "The world" and the first level subdirectories are "countries". Lower levels of the directory structure contain entries for companies, organisations or places, while yet lower still we find directory entries for people, and perhaps equipment or documents.

To refer to a file in a subdirectory on your hard disk, you might use something like:

/usr/local/myapp/docs

The forwards slash marks each division in the reference, and the sequence is read from left to right.

The equivalent to the fully qualified file reference in LDAP is the "distinguished name", referred to simply as "dn". An example dn might be:

cn=John Smith,ou=Accounts,o=My Company,c=US

The comma marks each division in the reference, and the sequence is read from right to left. You would read this dn as:

     country = US
     organization = My Company
     organizationalUnit = Accounts
     commonName = John Smith

In the same way as there are no hard rules about how you organise the directory structure of a hard disk, a directory server manager can set up any structure that is meaningful for the purpose. However, there are some conventions that are used. The message is that you can not write code to access a directory server unless you know something about its structure, any more than you can use a database without some knowledge of what is available.

Lots of information about LDAP can be found at

The Netscape SDK contains a helpful Programmer's Guide in HTML format.

Requirements

You will need to get and compile LDAP client libraries from either the University of Michigan ldap-3.3 package or the Netscape Directory SDK 3.0 to compile PHP with LDAP support.

Installation

LDAP support in PHP is not enabled by default. You will need to use the --with-ldap configuration option when compiling PHP to enable LDAP support.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. LDAP configuration options

Name	Default	Changeable
ldap.max_links	"-1"	PHP_INI_SYSTEM

For further details and definition of the PHP_INI_* constants see ini_set().

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

LDAP_DEREF_NEVER (integer)
LDAP_DEREF_SEARCHING (integer)
LDAP_DEREF_FINDING (integer)
LDAP_DEREF_ALWAYS (integer)
LDAP_OPT_DEREF (integer)
LDAP_OPT_SIZELIMIT (integer)
LDAP_OPT_TIMELIMIT (integer)
LDAP_OPT_PROTOCOL_VERSION (integer)
LDAP_OPT_ERROR_NUMBER (integer)
LDAP_OPT_REFERRALS (integer)
LDAP_OPT_RESTART (integer)
LDAP_OPT_HOST_NAME (integer)
LDAP_OPT_ERROR_STRING (integer)
LDAP_OPT_MATCHED_DN (integer)
LDAP_OPT_SERVER_CONTROLS (integer)
LDAP_OPT_CLIENT_CONTROLS (integer)
LDAP_OPT_DEBUG_LEVEL (integer)
GSLC_SSL_NO_AUTH (integer)
GSLC_SSL_ONEWAY_AUTH (integer)
GSLC_SSL_TWOWAY_AUTH (integer)

Examples

Retrieve information for all entries where the surname starts with "S" from a directory server, displaying an extract with name and email address.

Example 1. LDAP search example

<?php
// basic sequence with LDAP is connect, bind, search, interpret search
// result, close connection

echo "<h3>LDAP query test</h3>";
echo "Connecting ...";
$ds=ldap_connect("localhost");  // must be a valid LDAP server!
echo "connect result is ".$ds."<p>";

if ($ds) { 
    echo "Binding ..."; 
    $r=ldap_bind($ds);     // this is an "anonymous" bind, typically
                           // read-only access
    echo "Bind result is ".$r."<p>";

    echo "Searching for (sn=S*) ...";
    // Search surname entry
    $sr=ldap_search($ds,"o=My Company, c=US", "sn=S*");  
    echo "Search result is ".$sr."<p>";

    echo "Number of entires returned is ".ldap_count_entries($ds,$sr)."<p>";

    echo "Getting entries ...<p>";
    $info = ldap_get_entries($ds, $sr);
    echo "Data for ".$info["count"]." items returned:<p>";

    for ($i=0; $i<$info["count"]; $i++) {
        echo "dn is: ". $info[$i]["dn"] ."<br>";
        echo "first cn entry is: ". $info[$i]["cn"][0] ."<br>";
        echo "first email entry is: ". $info[$i]["mail"][0] ."<p>";
    }

    echo "Closing connection";
    ldap_close($ds);

} else {
    echo "<h4>Unable to connect to LDAP server</h4>";
}
?>

Using the PHP LDAP calls

Before you can use the LDAP calls you will need to know ..

The name or address of the directory server you will use
The "base dn" of the server (the part of the world directory that is held on this server, which could be "o=My Company,c=US")
Whether you need a password to access the server (many servers will provide read access for an "anonymous bind" but require a password for anything else)

The typical sequence of LDAP calls you will make in an application will follow this pattern:

  ldap_connect()    // establish connection to server
     |
  ldap_bind()       // anonymous or authenticated "login"
     |
  do something like search or update the directory
  and display the results
     |
  ldap_close()      // "logout"

Table of Contents
ldap_8859_to_t61 -- Translate 8859 characters to t61 characters
ldap_add -- Add entries to LDAP directory
ldap_bind -- Bind to LDAP directory
ldap_close -- Close link to LDAP server
ldap_compare -- Compare value of attribute found in entry specified with DN
ldap_connect -- Connect to an LDAP server
ldap_count_entries -- Count the number of entries in a search
ldap_delete -- Delete an entry from a directory
ldap_dn2ufn -- Convert DN to User Friendly Naming format
ldap_err2str -- Convert LDAP error number into string error message
ldap_errno -- Return the LDAP error number of the last LDAP command
ldap_error -- Return the LDAP error message of the last LDAP command
ldap_explode_dn -- Splits DN into its component parts
ldap_first_attribute -- Return first attribute
ldap_first_entry -- Return first result id
ldap_first_reference -- Return first reference
ldap_free_result -- Free result memory
ldap_get_attributes -- Get attributes from a search result entry
ldap_get_dn -- Get the DN of a result entry
ldap_get_entries -- Get all result entries
ldap_get_option -- Get the current value for given option
ldap_get_values_len -- Get all binary values from a result entry
ldap_get_values -- Get all values from a result entry
ldap_list -- Single-level search
ldap_mod_add -- Add attribute values to current attributes
ldap_mod_del -- Delete attribute values from current attributes
ldap_mod_replace -- Replace attribute values with new ones
ldap_modify -- Modify an LDAP entry
ldap_next_attribute -- Get the next attribute in result
ldap_next_entry -- Get next result entry
ldap_next_reference -- Get next reference
ldap_parse_reference -- Extract information from reference entry
ldap_parse_result -- Extract information from result
ldap_read -- Read an entry
ldap_rename -- Modify the name of an entry
ldap_search -- Search LDAP tree
ldap_set_option -- Set the value of the given option
ldap_set_rebind_proc -- Set a callback function to do re-binds on referral chasing.
ldap_sort -- Sort LDAP result entries
ldap_start_tls -- Start TLS
ldap_t61_to_8859 -- Translate t61 characters to 8859 characters
ldap_unbind -- Unbind from LDAP directory

ldap_8859_to_t61

(PHP 4 >= 4.0.2)

ldap_8859_to_t61 -- Translate 8859 characters to t61 characters

Description

string ldap_8859_to_t61 ( string value)

Warning

This function is currently not documented; only the argument list is available.

ldap_add

(PHP 3, PHP 4 )

ldap_add -- Add entries to LDAP directory

Description

bool ldap_add ( resource link_identifier, string dn, array entry)

Returns TRUE on success or FALSE on failure.

The ldap_add() function is used to add entries in the LDAP directory. The DN of the entry to be added is specified by dn. Array entry specifies the information about the entry. The values in the entries are indexed by individual attributes. In case of multiple values for an attribute, they are indexed using integers starting with 0.

    entry["attribute1"] = value
    entry["attribute2"][0] = value1
    entry["attribute2"][1] = value2

Example 1. Complete example with authenticated bind

<?php
$ds=ldap_connect("localhost");  // assuming the LDAP server is on this host

if ($ds) {
    // bind with appropriate dn to give update access
    $r=ldap_bind($ds,"cn=root, o=My Company, c=US", "secret");

    // prepare data
    $info["cn"]="John Jones";
    $info["sn"]="Jones";
    $info["mail"]="jonj@here.and.now";
    $info["objectclass"]="person";

    // add data to directory
    $r=ldap_add($ds, "cn=John Jones, o=My Company, c=US", $info);

    ldap_close($ds);
} else {
    echo "Unable to connect to LDAP server"; 
}
?>

ldap_bind

(PHP 3, PHP 4 )

ldap_bind -- Bind to LDAP directory

Description

bool ldap_bind ( resource link_identifier [, string bind_rdn [, string bind_password]])

Binds to the LDAP directory with specified RDN and password. Returns TRUE on success or FALSE on failure.

ldap_bind() does a bind operation on the directory. bind_rdn and bind_password are optional. If not specified, anonymous bind is attempted.

ldap_close

(PHP 3, PHP 4 )

ldap_close -- Close link to LDAP server

Description

bool ldap_close ( resource link_identifier)

Returns TRUE on success or FALSE on failure.

ldap_close() closes the link to the LDAP server that's associated with the specified link_identifier.

This call is internally identical to ldap_unbind(). The LDAP API uses the call ldap_unbind(), so perhaps you should use this in preference to ldap_close().

Note: This function is an alias of ldap_unbind().

ldap_compare

(PHP 4 >= 4.0.2)

ldap_compare -- Compare value of attribute found in entry specified with DN

Description

bool ldap_compare ( resource link_identifier, string dn, string attribute, string value)

Returns TRUE if value matches otherwise returns FALSE. Returns -1 on error.

ldap_compare() is used to compare value of attribute to value of same attribute in LDAP directory entry specified with dn.

The following example demonstrates how to check whether or not given password matches the one defined in DN specified entry.

Example 1. Complete example of password check

<?php

$ds=ldap_connect("localhost");  // assuming the LDAP server is on this host
      
if ($ds) {

    // bind 
    if(ldap_bind($ds)) {

        // prepare data
        $dn = "cn=Matti Meikku, ou=My Unit, o=My Company, c=FI";
        $value = "secretpassword";
        $attr = "password"; 

        // compare value
        $r=ldap_compare($ds, $dn, $attr, $value);

        if ($r === -1) {
            echo "Error: ".ldap_error($ds);
        } elseif ($r === TRUE) {
            echo "Password correct.";
        } elseif ($r === FALSE) {
            echo "Wrong guess! Password incorrect.";
        }

    } else {
        echo "Unable to bind to LDAP server.";
    }          

    ldap_close($ds);

} else {
    echo "Unable to connect to LDAP server.";
}
?>

Warning

ldap_compare() can NOT be used to compare BINARY values!

Note: This function was added in 4.0.2.

ldap_connect

(PHP 3, PHP 4 )

ldap_connect -- Connect to an LDAP server

Description

resource ldap_connect ( [string hostname [, int port]])

Returns a positive LDAP link identifier on success, or FALSE on error.

ldap_connect() establishes a connection to a LDAP server on a specified hostname and port. Both the arguments are optional. If no arguments are specified then the link identifier of the already opened link will be returned. If only hostname is specified, then the port defaults to 389.

If you are using OpenLDAP 2.x.x you can specify a URL instead of the hostname. To use LDAP with SSL, compile OpenLDAP 2.x.x with SSL support, configure PHP with SSL, and use ldaps://hostname/ as host parameter. The port parameter is not used when using URLs.

Note: URL and SSL support were added in 4.0.4.

(PHP 3>= 3.0.13, PHP 4 )

ldap_err2str -- Convert LDAP error number into string error message

bool ldap_free_result ( resource result_identifier)

Returns TRUE on success or FALSE on failure.

ldap_free_result() frees up the memory allocated internally to store the result and pointed by the result_identifier. All result memory will be automatically freed when the script terminates.

Typically all the memory allocated for the ldap result gets freed at the end of the script. In case the script is making successive searches which return large result sets, ldap_free_result() could be called to keep the runtime memory usage by the script low.

ldap_get_attributes

(PHP 3, PHP 4 )

ldap_get_attributes -- Get attributes from a search result entry

Description

array ldap_get_attributes ( resource link_identifier, resource result_entry_identifier)

Returns a complete entry information in a multi-dimensional array on success and FALSE on error.

ldap_get_attributes() function is used to simplify reading the attributes and values from an entry in the search result. The return value is a multi-dimensional array of attributes and values.

Having located a specific entry in the directory, you can find out what information is held for that entry by using this call. You would use this call for an application which "browses" directory entries and/or where you do not know the structure of the directory entries. In many applications you will be searching for a specific attribute such as an email address or a surname, and won't care what other data is held.

return_value["count"] = number of attributes in the entry
return_value[0] = first attribute
return_value[n] = nth attribute

return_value["attribute"]["count"] = number of values for attribute
return_value["attribute"][0] = first value of the attribute
return_value["attribute"][i] = (i+1)th value of the attribute

Example 1. Show the list of attributes held for a particular directory entry

// $ds is the link identifier for the directory

// $sr is a valid search result from a prior call to
// one of the ldap directory search calls

$entry = ldap_first_entry($ds, $sr);

$attrs = ldap_get_attributes($ds, $entry);

echo $attrs["count"]." attributes held for this entry:<p>";

for ($i=0; $i<$attrs["count"]; $i++)
    echo $attrs[$i]."<br>";

ldap_get_dn

(PHP 3, PHP 4 )

ldap_get_dn -- Get the DN of a result entry

Description

ldap_get_values() function is used to read all the values of the attribute in the entry in the result. entry is specified by the result_entry_identifier. The number of values can be found by indexing "count" in the resultant array. Individual values are accessed by integer index in the array. The first index is 0.

This call needs a result_entry_identifier, so needs to be preceded by one of the ldap search calls and one of the calls to get an individual entry.

You application will either be hard coded to look for certain attributes (such as "surname" or "mail") or you will have to use the ldap_get_attributes() call to work out what attributes exist for a given entry.

LDAP allows more than one entry for an attribute, so it can, for example, store a number of email addresses for one person's directory entry all labeled with the attribute "mail"

return_value["count"] = number of values for attribute
return_value[0] = first value of attribute
return_value[i] = ith value of attribute

Example 1. List all values of the "mail" attribute for a directory entry

// $ds is a valid link identifier for a directory server

// $sr is a valid search result from a prior call to
//     one of the ldap directory search calls

// $entry is a valid entry identifier from a prior call to
//        one of the calls that returns a directory entry

$values = ldap_get_values($ds, $entry,"mail");

echo $values["count"]." email addresses for this entry.<p>";

for ($i=0; $i < $values["count"]; $i++)
    echo $values[$i]."<br>";

ldap_list

(PHP 3, PHP 4 )

ldap_list -- Single-level search

Description

resource ldap_list ( resource link_identifier, string base_dn, string filter [, array attributes [, int attrsonly [, int sizelimit [, int timelimit [, int deref]]]]])

Returns a search result identifier or FALSE on error.

ldap_list() performs the search for a specified filter on the directory with the scope LDAP_SCOPE_ONELEVEL.

LDAP_SCOPE_ONELEVEL means that the search should only return information that is at the level immediately below the base_dn given in the call. (Equivalent to typing "ls" and getting a list of files and folders in the current working directory.)

This call takes 5 optional parameters. See ldap_search() notes.

Note: These optional parameters were added in 4.0.2: attrsonly, sizelimit, timelimit, deref.

Example 1. Produce a list of all organizational units of an organization

// $ds is a valid link identifier for a directory server

$basedn = "o=My Company, c=US";
$justthese = array("ou");

$sr=ldap_list($ds, $basedn, "ou=*", $justthese);

$info = ldap_get_entries($ds, $sr);

for ($i=0; $i<$info["count"]; $i++)
    echo $info[$i]["ou"][0] ;

Note: From 4.0.5 on it's also possible to do parallel searches. See ldap_search() for details.

An empty filter is not allowed. If you want to retrieve absolutely all information for this entry, use a filter of "objectClass=*". If you know which entry types are used on the directory server, you might use an appropriate filter such as "objectClass=inetOrgPerson".

This call takes 5 optional parameters. See ldap_search() notes.

Note: These optional parameters were added in 4.0.2: attrsonly, sizelimit, timelimit, deref.

From 4.0.5 on it's also possible to do parallel searches. See ldap_search() for details.

ldap_rename

(PHP 4 >= 4.0.5)

ldap_rename -- Modify the name of an entry

Description

bool ldap_rename ( resource link_identifier, string dn, string newrdn, string newparent, bool deleteoldrdn)

The entry specified by dn is renamed/moved. The new RDN is specified by newrdn and the new parent/superior entry is specified by newparent. If the parameter deleteoldrdn is TRUE the old RDN value(s) is removed, else the old RDN value(s) is retained as non-distinguished values of the entry. Returns TRUE on success or FALSE on failure.

Note: This function currently only works with LDAPv3. You may have to use ldap_set_option() prior to binding to use LDAPv3. This function is only available when using OpenLDAP 2.x.x OR Netscape Directory SDK x.x, and was added in PHP 4.0.5.

ldap_search

(PHP 3, PHP 4 )

ldap_search -- Search LDAP tree

Description

resource ldap_search ( resource link_identifier, string base_dn, string filter [, array attributes [, int attrsonly [, int sizelimit [, int timelimit [, int deref]]]]])

Returns a search result identifier or FALSE on error.

ldap_search() performs the search for a specified filter on the directory with the scope of LDAP_SCOPE_SUBTREE. This is equivalent to searching the entire directory. base_dn specifies the base DN for the directory.

There is a optional fourth parameter, that can be added to restrict the attributes and values returned by the server to just those required. This is much more efficient than the default action (which is to return all attributes and their associated values). The use of the fourth parameter should therefore be considered good practice.

The fourth parameter is a standard PHP string array of the required attributes, eg array("mail","sn","cn") Note that the "dn" is always returned irrespective of which attributes types are requested.

Note too that some directory server hosts will be configured to return no more than a preset number of entries. If this occurs, the server will indicate that it has only returned a partial results set. This occurs also if the sixth parameter sizelimit has been used to limit the count of fetched entries.

The fifth parameter attrsonly should be set to 1 if only attribute types are wanted. If set to 0 both attributes types and attribute values are fetched which is the default behaviour.

With the sixth parameter sizelimit it is possible to limit the count of entries fetched. Setting this to 0 means no limit. NOTE: This parameter can NOT override server-side preset sizelimit. You can set it lower though.

The seventh parameter timelimit sets the number of seconds how long is spend on the search. Setting this to 0 means no limit. NOTE: This parameter can NOT override server-side preset timelimit. You can set it lower though.

The eigth parameter deref specifies how aliases should be handled during the search. It can be one of the following:

LDAP_DEREF_NEVER - (default) aliases are never dereferenced.
LDAP_DEREF_SEARCHING - aliases should be dereferenced during the search but not when locating the base object of the search.
LDAP_DEREF_FINDING - aliases should be dereferenced when locating the base object but not during the search.
LDAP_DEREF_ALWAYS - aliases should be dereferenced always.

Note: These optional parameters were added in 4.0.2: attrsonly, sizelimit, timelimit, deref.

The search filter can be simple or advanced, using boolean operators in the format described in the LDAP doumentation (see the Netscape Directory SDK for full information on filters).

The example below retrieves the organizational unit, surname, given name and email address for all people in "My Company" where the surname or given name contains the substring $person. This example uses a boolean filter to tell the server to look for information in more than one attribute.
Example 1. LDAP search
// $ds is a valid link identifier for a directory server // $person is all or part of a person's name, eg "Jo" $dn = "o=My Company, c=US"; $filter="(|(sn=$person*)(givenname=$person*))"; $justthese = array( "ou", "sn", "givenname", "mail"); $sr=ldap_search($ds, $dn, $filter, $justthese); $info = ldap_get_entries($ds, $sr); print $info["count"]." entries returned<p>";

From 4.0.5 on it's also possible to do parallel searches. To do this you use an array of link identifiers, rather than a single identifier, as the first argument. If you don't want the same base DN and the same filter for all the searches, you can also use an array of base DNs and/or an array of filters. Those arrays must be of the same size as the link identifier array since the first entries of the arrays are used for one search, the second entries are used for another, and so on. When doing parallel searches an array of search result identifiers is returned, except in case of error, then the entry corresponding to the search will be FALSE. This is very much like the value normally returned, except that a result identifier is always returned when a search was made. There are some rare cases where the normal search returns FALSE while the parallel search returns an identifier.

ldap_set_option

(PHP 4 >= 4.0.4)

ldap_set_option -- Set the value of the given option

Description

bool ldap_set_option ( resource link_identifier, int option, mixed newval)

Sets the value of the specified option to be newval. Returns TRUE on success or FALSE on failure. on error.

The parameter option can be one of: LDAP_OPT_DEREF, LDAP_OPT_SIZELIMIT, LDAP_OPT_TIMELIMIT, LDAP_OPT_PROTOCOL_VERSION, LDAP_OPT_ERROR_NUMBER, LDAP_OPT_REFERRALS, LDAP_OPT_RESTART, LDAP_OPT_HOST_NAME, LDAP_OPT_ERROR_STRING, LDAP_OPT_MATCHED_DN, LDAP_OPT_SERVER_CONTROLS, LDAP_OPT_CLIENT_CONTROLS. Here's a brief description, see draft-ietf-ldapext-ldap-c-api-xx.txt for details.

The options LDAP_OPT_DEREF, LDAP_OPT_SIZELIMIT, LDAP_OPT_TIMELIMIT, LDAP_OPT_PROTOCOL_VERSION and LDAP_OPT_ERROR_NUMBER have integer value, LDAP_OPT_REFERRALS and LDAP_OPT_RESTART have boolean value, and the options LDAP_OPT_HOST_NAME, LDAP_OPT_ERROR_STRING and LDAP_OPT_MATCHED_DN have string value. The first example illustrates their use. The options LDAP_OPT_SERVER_CONTROLS and LDAP_OPT_CLIENT_CONTROLS require a list of controls, this means that the value must be an array of controls. A control consists of an oid identifying the control, an optional value, and an optional flag for criticality. In PHP a control is given by an array containing an element with the key oid and string value, and two optional elements. The optional elements are key value with string value and key iscritical with boolean value. iscritical defaults to FALSE if not supplied. See also the second example below.

Note: This function is only available when using OpenLDAP 2.x.x OR Netscape Directory SDK x.x, and was added in PHP 4.0.4.

ldap_unbind() function unbinds from the LDAP directory.

XLIX. Mail functions

Introduction

The mail() function allows you to send mail.

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Mail configuration options

Name	Default	Changeable
SMTP	"localhost"	PHP_INI_ALL
smtp_port	"25"	PHP_INI_ALL
sendmail_from	NULL	PHP_INI_ALL
sendmail_path	DEFAULT_SENDMAIL_PATH	PHP_INI_SYSTEM

For further details and definition of the PHP_INI_* constants see ini_set().

Here is a short explanation of the configuration directives.

SMTP string

Used under Windows only: DNS name or IP address of the SMTP server PHP should use for mail sent with the mail() function.

SMTP int

Used under Windows only: Number of the port to connect to the server specified with the SMTP setting when sending mail with mail(); defaults to 25. Only available since PHP 4.3.0.

sendmail_from string

Which "From:" mail address should be used in mail sent from PHP under Windows.

sendmail_path string

Where the sendmail program can be found, usually /usr/sbin/sendmail or /usr/lib/sendmail. configure does an honest attempt of locating this one for you and set a default, but if it fails, you can set it here.

Systems not using sendmail should set this directive to the sendmail wrapper/replacement their mail system offers, if any. For example, Qmail users can normally set it to /var/qmail/bin/sendmail or /var/qmail/bin/qmail-inject.

qmail-inject does not require any option to process mail correctly.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Table of Contents
ezmlm_hash -- Calculate the hash value needed by EZMLM
mail -- send mail

ezmlm_hash

(PHP 3>= 3.0.17, PHP 4 >= 4.0.2)

ezmlm_hash -- Calculate the hash value needed by EZMLM

Description

int ezmlm_hash ( string addr)

ezmlm_hash() calculates the hash value needed when keeping EZMLM mailing lists in a MySQL database.

Example 1. Calculating the hash and subscribing a user
$user = "joecool@example.com"; $hash = ezmlm_hash ($user); $query = sprintf ("INSERT INTO sample VALUES (%s, '%s')", $hash, $user); $db->query($query); // using PHPLIB db interface

mail

(PHP 3, PHP 4 )

mail -- send mail

Description

bool mail ( string to, string subject, string message [, string additional_headers [, string additional_parameters]])

mail() automatically mails the message specified in message to the receiver specified in to. Multiple recipients can be specified by putting a comma between each address in to. Email with attachments and special types of content can be sent using this function. This is accomplished via MIME-encoding - for more information, see this Zend article or the PEAR Mime Classes.

The following RFC's may also be useful: RFC 1896, RFC 2045, RFC 2046, RFC 2047, RFC 2048, and RFC 2049.

mail() returns TRUE if the mail was successfully accepted for delivery, FALSE otherwise.

Warning

The Windows implementation of mail() differs in many ways from the Unix implementation. First, it doesn't use a local binary for composing messages but only operates on direct sockets which means a MTA is needed listening on a network socket (which can either on the localhost or a remote machine). Second, the custom headers like From:, Cc:, Bcc: and Date: are not interpreted by the MTA in the first place, but are parsed by PHP. PHP < 4.3 only supported the Cc: header element (and was case-sensitive). PHP >= 4.3 supports all the mentioned header elements and is no longer case-sensitive.

Example 1. Sending mail.
mail("joecool@example.com", "My Subject", "Line 1\nLine 2\nLine 3");

If a fourth string argument is passed, this string is inserted at the end of the header. This is typically used to add extra headers. Multiple extra headers are separated with a carriage return and newline.

Note: You must use \r\n to seperate headers, although some Unix mail transfer agents may work with just a single newline (\n).

Example 2. Sending mail with extra headers.
mail("nobody@example.com", "the subject", $message, "From: webmaster@$SERVER_NAME\r\n" ."Reply-To: webmaster@$SERVER_NAME\r\n" ."X-Mailer: PHP/" . phpversion());

The additional_parameters parameter can be used to pass an additional parameter to the program configured to use when sending mail using the sendmail_path configuration setting. For example, this can be used to set the envelope sender address when using sendmail. You may need to add the user that your web server runs as to your sendmail configuration to prevent a 'X-Warning' header from being added to the message when you set the envelope sender using this method.
Example 3. Sending mail with extra headers and setting an additional command line parameter.
mail("nobody@example.com", "the subject", $message, "From: webmaster@$SERVER_NAME", "-fwebmaster@$SERVER_NAME");

Note: This fifth parameter was added in PHP 4.0.5. Since PHP 4.2.3 this parameter is disabled in safe_mode and the mail() function will expose a warning message and return FALSE if you're trying to use it.

You can also use simple string building techniques to build complex email messages.
Example 4. Sending complex email.
/* recipients */ $to = "Mary <mary@example.com>" . ", " ; // note the comma $to .= "Kelly <kelly@example.com>"; /* subject */ $subject = "Birthday Reminders for August"; /* message */ $message = ' <html> <head> <title>Birthday Reminders for August</title> </head> <body> <p>Here are the birthdays upcoming in August!</p> <table> <tr> <th>Person</th><th>Day</th><th>Month</th><th>Year</th> </tr> <tr> <td>Joe</td><td>3rd</td><td>August</td><td>1970</td> </tr> <tr> <td>Sally</td><td>17th</td><td>August</td><td>1973</td> </tr> </table> </body> </html> '; /* To send HTML mail, you can set the Content-type header. */ $headers = "MIME-Version: 1.0\r\n"; $headers .= "Content-type: text/html; charset=iso-8859-1\r\n"; /* additional headers */ $headers .= "From: Birthday Reminder <birthday@example.com>\r\n"; $headers .= "Cc: birthdayarchive@example.com\r\n"; $headers .= "Bcc: birthdaycheck@example.com\r\n"; /* and now mail it */ mail($to, $subject, $message, $headers);

Note: Make sure you do not have any newline characters in the to or subject, or the mail may not be sent properly.

Note: The to parameter cannot be an address in the form of "Something <someone@example.com>". The mail command will not parse this properly while talking with the MTA.

L. mailparse functions

Introduction

Warning

Table of Contents
mailparse_determine_best_xfer_encoding -- Figures out the best way of encoding the content read from the file pointer fp, which must be seek-able
mailparse_msg_create -- Returns a handle that can be used to parse a message
mailparse_msg_extract_part_file -- Extracts/decodes a message section, decoding the transfer encoding
mailparse_msg_extract_part -- Extracts/decodes a message section. If callbackfunc is not specified, the contents will be sent to "stdout"
mailparse_msg_free -- Frees a handle allocated by mailparse_msg_crea
mailparse_msg_get_part_data -- Returns an associative array of info about the message
mailparse_msg_get_part -- Returns a handle on a given section in a mimemessage
mailparse_msg_get_structure -- Returns an array of mime section names in the supplied message
mailparse_msg_parse_file -- Parse file and return a resource representing the structure
mailparse_msg_parse -- Incrementally parse data into buffer
mailparse_rfc822_parse_addresses -- Parse addresses and returns a hash containing that data
mailparse_stream_encode -- Streams data from source file pointer, apply encoding and write to destfp
mailparse_uudecode_all -- Scans the data from fp and extract each embedded uuencoded file. Returns an array listing filename information

LI. Mathematical Functions

Introduction

These math functions will only handle values within the range of the integer and float types on your computer (this corresponds currently to the C types long resp. double). If you need to handle bigger numbers, take a look at the arbitrary precision math functions.

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are always available as part of the PHP core.

Table 1. Math constants

Constant	Value	Description
M_PI	3.14159265358979323846	Pi
M_E	2.7182818284590452354	e
M_LOG2E	1.4426950408889634074	log_2 e
M_LOG10E	0.43429448190325182765	log_10 e
M_LN2	0.69314718055994530942	log_e 2
M_LN10	2.30258509299404568402	log_e 10
M_PI_2	1.57079632679489661923	pi/2
M_PI_4	0.78539816339744830962	pi/4
M_1_PI	0.31830988618379067154	1/pi
M_2_PI	0.63661977236758134308	2/pi
M_SQRTPI	1.77245385090551602729	sqrt(pi) [4.0.2]
M_2_SQRTPI	1.12837916709551257390	2/sqrt(pi)
M_SQRT2	1.41421356237309504880	sqrt(2)
M_SQRT3	1.73205080756887729352	sqrt(3) [4.0.2]
M_SQRT1_2	0.70710678118654752440	1/sqrt(2)
M_LNPI	1.14472988584940017414	log_e(pi) [4.0.2]
M_EULER	0.57721566490153286061	Euler constant [4.0.2]

Only M_PI is available in PHP versions up to and including PHP 4.0.0. All other constants are available starting with PHP 4.0.0. Constants labeled [4.0.2] were added in PHP 4.0.2.

Table of Contents
abs -- Absolute value
acos -- Arc cosine
acosh -- Inverse hyperbolic cosine
asin -- Arc sine
asinh -- Inverse hyperbolic sine
atan2 -- arc tangent of two variables
atan -- Arc tangent
atanh -- Inverse hyperbolic tangent
base_convert -- Convert a number between arbitrary bases
bindec -- Binary to decimal
ceil -- Round fractions up
cos -- Cosine
cosh -- Hyperbolic cosine
decbin -- Decimal to binary
dechex -- Decimal to hexadecimal
decoct -- Decimal to octal
deg2rad -- Converts the number in degrees to the radian equivalent
exp -- e to the power of ...
expm1 -- Returns exp(number) - 1, computed in a way that is accurate even when the value of number is close to zero
floor -- Round fractions down
getrandmax -- Show largest possible random value
hexdec -- Hexadecimal to decimal
hypot -- Returns sqrt( num1*num1 + num2*num2)
is_finite --
is_infinite --
is_nan --
lcg_value -- Combined linear congruential generator
log10 -- Base-10 logarithm
log1p -- Returns log(1 + number), computed in a way that accurate even when the val ue of number is close to zero
log -- Natural logarithm
max -- Find highest value
min -- Find lowest value
mt_getrandmax -- Show largest possible random value
mt_rand -- Generate a better random value
mt_srand -- Seed the better random number generator
octdec -- Octal to decimal
pi -- Get value of pi
pow -- Exponential expression
rad2deg -- Converts the radian number to the equivalent number in degrees
rand -- Generate a random value
round -- Rounds a float
sin -- Sine
sinh -- Hyperbolic sine
sqrt -- Square root
srand -- Seed the random number generator
tan -- Tangent
tanh -- Hyperbolic tangent

abs

(PHP 3, PHP 4 )

abs -- Absolute value

Description

mixed abs ( mixed number)

Returns the absolute value of number. If the argument number is of type float, the return type is also float, otherwise it is integer (as float usually has a bigger value range than integer).

Example 1. abs() example

$abs = abs(-4.2); // $abs = 4.2; (double/float)
$abs2 = abs(5);   // $abs2 = 5; (integer)
$abs3 = abs(-5);  // $abs3 = 5; (integer)

acos

(PHP 3, PHP 4 )

acos -- Arc cosine

Description

float acos ( float arg)

Returns the arc cosine of arg in radians. acos() is the complementary function of cos(), which means that a==cos(acos(a)) for every value of a that is within acos()' range.

See also acosh(), asin() and atan().

acosh

(PHP 4 >= 4.1.0)

acosh -- Inverse hyperbolic cosine

Description

float acosh ( float arg)

Returns the inverse hyperbolic cosine of arg, i.e. the value whose hyperbolic cosine is arg.

Note: This function is not implemented on Windows platforms.

See also acos(), asinh() and atanh().

asin

(PHP 3, PHP 4 )

asin -- Arc sine

Description

float asin ( float arg)

Returns the arc sine of arg in radians. asin() is the complementary function of sin(), which means that a==sin(asin(a)) for every value of a that is within asin()'s range.

See also asinh(), acos() and atan().

asinh

(PHP 4 >= 4.1.0)

asinh -- Inverse hyperbolic sine

Description

float asinh ( float arg)

Returns the inverse hyperbolic sine of arg, i.e. the value whose hyperbolic sine is arg.

Note: This function is not implemented on Windows platforms.

Note: This function is not implemented on Windows platforms.

See also atan(), asinh() and acosh().

base_convert

(PHP 3>= 3.0.6, PHP 4 )

base_convert -- Convert a number between arbitrary bases

Description

string base_convert ( string number, int frombase, int tobase)

Returns a string containing number represented in base tobase. The base in which number is given is specified in frombase. Both frombase and tobase have to be between 2 and 36, inclusive. Digits in numbers with a base higher than 10 will be represented with the letters a-z, with a meaning 10, b meaning 11 and z meaning 35.
Example 1. base_convert()
$binary = base_convert ($hexadecimal, 16, 2);

bindec

(PHP 3, PHP 4 )

bindec -- Binary to decimal

Description

int bindec ( string binary_string)

Returns the decimal equivalent of the binary number represented by the binary_string argument.

bindec() converts a binary number to an integer. The largest number that can be converted is 31 bits of 1's or 2147483647 in decimal.

ceil

(PHP 3, PHP 4 )

ceil -- Round fractions up

Description

float ceil ( float value)

Returns the next highest integer value by rounding up value if necessary. The return value of ceil() is still of type float as the value range of float is usually bigger than that of integer.

Example 1. ceil() example

echo ceil(4.3);    // 5
echo ceil(9.999);  // 10

cos

(PHP 3, PHP 4 )

cos -- Cosine

Description

float cos ( float arg)

cos() returns the cosine of the arg parameter. The arg parameter is in radians.

See also acos(), sin() tan() and deg2rad().

cosh

(PHP 4 >= 4.1.0)

cosh -- Hyperbolic cosine

Description

float cosh ( float arg)

float expm1 ( float number)

Warning

This function is currently not documented; only the argument list is available.

floor

(PHP 3, PHP 4 )

floor -- Round fractions down

Description

float floor ( float value)

Returns the next lowest integer value by rounding down value if necessary. The return value of floor() is still of type float because the value range of float is usually bigger than that of integer.

Example 1. floor() example

echo floor(4.3);   // 4
echo floor(9.999); // 9

getrandmax

(PHP 3, PHP 4 )

getrandmax -- Show largest possible random value

float log1p ( float number)

Warning

This function is currently not documented; only the argument list is available.

log

(PHP 3, PHP 4 )

log -- Natural logarithm

Description

float log ( float arg)

Returns the natural logarithm of arg.

max

(PHP 3, PHP 4 )

max -- Find highest value

Description

mixed max ( mixed arg1, mixed arg2, mixed argn)

max() returns the numerically highest of the parameter values.

If the first parameter is an array, max() returns the highest value in that array. If the first parameter is an integer, string or float, you need at least two parameters and max() returns the biggest of these values. You can compare an unlimited number of values.

If one or more of the values is a float, all the values will be treated as floats, and a float is returned. If none of the values is a float, all of them will be treated as integers, and an integer is returned.

min

(PHP 3, PHP 4 )

min -- Find lowest value

Description

number min ( number arg1, number arg2 [, ...])

number min ( array numbers)

min() returns the numerically lowest of the parameter values.

In the first variant, you need at least two parameters and min() returns the lowest of these values. You can compare an unlimited number of values. If one of the variables is undefined, min() will fail.

In the second variant, min() returns the lowest value in numbers.

If one or more of the values is a float, all the values will be treated as floats, and a float is returned. If none of the values is a float, all of them will be treated as integers, and an integer is returned. Upon failure, min() returns NULL and an error of level E_WARNING is generated.

<?php
$a = 4; 
$b = 9; 
$c = 3;
$arr = array(99, 34, 11);

// You may want to implement your own error checking in 
// case of failure (a variable may not be set)
if (!$min_value = @min($a, $b, $c)) {
    echo "Could not get min value, please try again.";
} else {
    echo "min value is $min_value";
}

print min($arr);  // 11

?>

mt_getrandmax

void mt_srand ( int seed)

Seeds the random number generator with seed.

// seed with microseconds
function make_seed() {
    list($usec, $sec) = explode(' ', microtime());
    return (float) $sec + ((float) $usec * 100000);
}
mt_srand(make_seed());
$randval = mt_rand();

Note: Since PHP 4.2.0 it's no longer necessary to seed the random number generator before using it.

octdec

(PHP 3, PHP 4 )

octdec -- Octal to decimal

Description

int octdec ( string octal_string)

Returns the decimal equivalent of the octal number represented by the octal_string argument. The largest number that can be converted is 17777777777 or 2147483647 in decimal.

pi

(PHP 3, PHP 4 )

pi -- Get value of pi

Description

float pi ( void)

Returns an approximation of pi. The returned float has a precision based on the precision directive in php.ini, which defaults to 14. Also, you can use the M_PI constant which yields identical results to pi().

echo pi(); // 3.1415926535898
echo M_PI; // 3.1415926535898

pow

(PHP 3, PHP 4 )

pow -- Exponential expression

Description

number pow ( number base, number exp)

Returns base raised to the power of exp. If possible, this function will return an integer.

If the power cannot be computed, a warning will be issued, and pow() will return FALSE.

Example 1. Some examples of pow()

<?php

var_dump( pow(2,8) ); // int(256)
echo pow(-1,20); // 1
echo pow(0, 0); // 1

echo pow(-1, 5.5); // error

?>

Warning

In PHP 4.0.6 and earlier pow() always returned a float, and did not issue warnings.

rad2deg

float round ( float val [, int precision])

Returns the rounded value of val to specified precision (number of digits after the decimal point). precision can also be negative or zero (default).

Caution

PHP doesn't handle strings like "12,300.2" correctly by default. See converting from strings.

echo round(3.4);         // 3
echo round(3.5);         // 4
echo round(3.6);         // 4
echo round(3.6, 0);      // 4
echo round(1.95583, 2);  // 1.96
echo round(1241757, -3); // 1242000

Note: The precision parameter is only available in PHP 4.

sin

(PHP 3, PHP 4 )

sin -- Sine

Description

float sin ( float arg)

sin() returns the sine of the arg parameter. The arg parameter is in radians.

<?php

// Precision depends on your precision directive
print sin(deg2rad(60));  //  0.866025403 ...
print sin(60);           // -0.304810621 ...

?>

// seed with microseconds
function make_seed() {
    list($usec, $sec) = explode(' ', microtime());
    return (float) $sec + ((float) $usec * 100000);
}
srand(make_seed());
$randval = rand();

Note: Since PHP 4.2.0 it's no longer necessary to seed the random number generator before using it.

tan

(PHP 3, PHP 4 )

tan -- Tangent

Description

float tan ( float arg)

tan() returns the tangent of the arg parameter. The arg parameter is in radians.

See also atan(), sin(), cos() and deg2rad().

tanh

(PHP 4 >= 4.1.0)

tanh -- Hyperbolic tangent

Description

float tanh ( float arg)

Returns the hyperbolic tangent of arg, defined as sinh(arg)/cosh(arg).

See also tan(), atanh(), sin() and cos().

LII. Multi-Byte String Functions

Introduction

There are many languages in which all characters can be expressed by single byte. Multi-byte character codes are used to express many characters for many languages. mbstring is developed to handle Japanese characters. However, many mbstring functions are able to handle character encoding other than Japanese.

A multi-byte character encoding represents single character with consecutive bytes. Some character encoding has shift(escape) sequences to start/end multi-byte character strings. Therefore, a multi-byte character string may be destroyed when it is divided and/or counted unless multi-byte character encoding safe method is used. This module provides multi-byte character safe string functions and other utility functions such as conversion functions.

Since PHP is basically designed for ISO-8859-1, some multi-byte character encoding does not work well with PHP. Therefore, it is important to set mbstring.internal_encoding to a character encoding that works with PHP.

PHP4 Character Encoding Requirements

Per byte encoding
Single byte characters in range of 00h-7fh which is compatible with ASCII
Multi-byte characters without 00h-7fh

These are examples of internal character encoding that works with PHP and does NOT work with PHP.

Character encodings work with PHP: 
ISO-8859-*, EUC-JP, UTF-8

Character encodings do NOT work with PHP:
JIS, SJIS

Character encoding, that does not work with PHP, may be converted with mbstring's HTTP input/output conversion feature/function.

Note: SJIS should not be used for internal encoding unless the reader is familiar with parser/compiler, character encoding and character encoding issues.

Note: If you use databases with PHP, it is recommended that you use the same character encoding for both database and internal encoding for ease of use and better performance.
If you are using PostgreSQL, it supports character encoding that is different from backend character encoding. See the PostgreSQL manual for details.

Installation

mbstring is an extended module. You must enable the module with the configure script. Refer to the Install section for details.

The following configure options are related to the mbstring module.

--enable-mbstring : Enable mbstring functions. This option is required to use mbstring functions.
Note: As of PHP 4.3.0, the option --enable-mbstring will be enabled by default and replaced with --with-mbstring[=LANG] to support Chinese, Korean and Russian language support. Japanese character encoding is supported by default. If --with-mbstring=cn is used, simplified chinese encoding will be supported. If --with-mbstring=tw is used, traditional chinese encoding will be supported. If --with-mbstring=kr is used, korean encoding will be supported. If --with-mbstring=ru is used, russian encoding will be supported. If --with-mbstring=all is added, all supported character encoding in mbstring will be enabled, but the binary size of PHP will be maximized because of huge Unicode character maps. Note that Chinese, Korean and Russian encoding is experimentally supported in PHP 4.3.0.
--enable-mbstr-enc-trans : Enable HTTP input character encoding conversion using mbstring conversion engine. If this feature is enabled, HTTP input character encoding may be converted to mbstring.internal_encoding automatically.
Note: As of PHP 4.3.0, the option --enable-mbstr-enc-trans will be eliminated and replaced with mbstring.encoding_translation. HTTP input character encoding conversion is enabled when this is set to On (the default is Off).
--enable-mbregex : Enable regular expression functions with multibyte character support.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Multi-Byte String configuration options

Name	Default	Changeable
mbstring.language	NULL	PHP_INI_ALL
mbstring.detect_order	NULL	PHP_INI_ALL
mbstring.http_input	NULL	PHP_INI_ALL
mbstring.http_output	NULL	PHP_INI_ALL
mbstring.internal_encoding	NULL	PHP_INI_ALL
mbstring.script_encoding	NULL	PHP_INI_ALL
mbstring.substitute_character	NULL	PHP_INI_ALL
mbstring.func_overload	"0"	PHP_INI_SYSTEM
mbstring.encoding_translation	"0"	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Here is a short explanation of the configuration directives.

mbstring.language defines default language used in mbstring. Note that this option defines mbstring.interanl_encoding and mbstring.interanl_encoding should be placed after mbstring.language in php.ini
mbstring.encoding_translation enables HTTP input character encoding detection and translation into internal chatacter encoding.
mbstring.internal_encoding defines default internal character encoding.
mbstring.http_input defines default HTTP input character encoding.
mbstring.http_output defines default HTTP output character encoding.
mbstring.detect_order defines default character code detection order. See also mb_detect_order().
mbstring.substitute_character defines character to substitute for invalid character encoding.
mbstring.func_overloadoverload(replace) single byte functions by mbstring functions. mail(), ereg(), etc. are overloaded by mb_send_mail(), mb_ereg(), etc. Possible values are 0, 1, 2, 4 or a combination of them. For example, 7 for overload everything. 0: No overload, 1: Overload mail() function, 2: Overload str*() functions, 4: Overload ereg*() functions.

Web Browsers are supposed to use the same character encoding when submitting form. However, browsers may not use the same character encoding. See mb_http_input() to detect character encoding used by browsers.

If enctype is set to multipart/form-data in HTML forms, mbstring does not convert character encoding in POST data. The user must convert them in the script, if conversion is needed.

Although, browsers are smart enough to detect character encoding in HTML. charset is better to be set in HTTP header. Change default_charset according to character encoding.

Example 1. php.ini setting example
; Set default language mbstring.language = English; Set default language to English (default) mbstring.language = Japanese; Set default language to Japanese ;; Set default internal encoding ;; Note: Make sure to use character encoding works with PHP mbstring.internal_encoding = UTF-8 ; Set internal encoding to UTF-8 ;; HTTP input encoding translation is enabled. mbstring.encoding_translation = On ;; Set default HTTP input character encoding ;; Note: Script cannot change http_input setting. mbstring.http_input = pass ; No conversion. mbstring.http_input = auto ; Set HTTP input to auto ; "auto" is expanded to "ASCII,JIS,UTF-8,EUC-JP,SJIS" mbstring.http_input = SJIS ; Set HTTP2 input to SJIS mbstring.http_input = UTF-8,SJIS,EUC-JP ; Specify order ;; Set default HTTP output character encoding mbstring.http_output = pass ; No conversion mbstring.http_output = UTF-8 ; Set HTTP output encoding to UTF-8 ;; Set default character encoding detection order mbstring.detect_order = auto ; Set detect order to auto mbstring.detect_order = ASCII,JIS,UTF-8,SJIS,EUC-JP ; Specify order ;; Set default substitute character mbstring.substitute_character = 12307 ; Specify Unicode value mbstring.substitute_character = none ; Do not print character mbstring.substitute_character = long ; Long Example: U+3000,JIS+7E7E

Example 2. php.ini setting for EUC-JP users
;; Disable Output Buffering output_buffering = Off ;; Set HTTP header charset default_charset = EUC-JP ;; Set default language to Japanese mbstring.language = Japanese ;; HTTP input encoding translation is enabled. mbstring.encoding_translation = On ;; Set HTTP input encoding conversion to auto mbstring.http_input = auto ;; Convert HTTP output to EUC-JP mbstring.http_output = EUC-JP ;; Set internal encoding to EUC-JP mbstring.internal_encoding = EUC-JP ;; Do not print invalid characters mbstring.substitute_character = none

Example 3. php.ini setting for SJIS users
;; Enable Output Buffering output_buffering = On ;; Set mb_output_handler to enable output conversion output_handler = mb_output_handler ;; Set HTTP header charset default_charset = Shift_JIS ;; Set default language to Japanese mbstring.language = Japanese ;; Set http input encoding conversion to auto mbstring.http_input = auto ;; Convert to SJIS mbstring.http_output = SJIS ;; Set internal encoding to EUC-JP mbstring.internal_encoding = EUC-JP ;; Do not print invalid characters mbstring.substitute_character = none

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

MB_OVERLOAD_MAIL (integer)
MB_OVERLOAD_STRING (integer)
MB_OVERLOAD_REGEX (integer)

HTTP Input and Output

HTTP input/output character encoding conversion may convert binary data also. Users are supposed to control character encoding conversion if binary data is used for HTTP input/output.

If enctype for HTML form is set to multipart/form-data, mbstring does not convert character encoding in POST data. If it is the case, strings are needed to be converted to internal character encoding.

HTTP Input

There is no way to control HTTP input character conversion from PHP script. To disable HTTP input character conversion, it has to be done in php.ini.
Example 4. Disable HTTP input conversion in php.ini
;; Disable HTTP Input conversion mbstring.http_input = pass ;; Disable HTTP Input conversion (PHP 4.3.0 or higher) mbstring.encoding_translation = Off

When using PHP as an Apache module, it is possible to override PHP ini setting per Virtual Host in httpd.conf or per directory with .htaccess. Refer to the Configuration section and Apache Manual for details.

HTTP Output
There are several ways to enable output character encoding conversion. One is using php.ini, another is using ob_start() with mb_output_handler() as ob_start callback function.
Note: For PHP3-i18n users, mbstring's output conversion differs from PHP3-i18n. Character encoding is converted using output buffer.

Example 5. php.ini setting example
;; Enable output character encoding conversion for all PHP pages ;; Enable Output Buffering output_buffering = On ;; Set mb_output_handler to enable output conversion output_handler = mb_output_handler

Example 6. Script example
<?php // Enable output character encoding conversion only for this page // Set HTTP output character encoding to SJIS mb_http_output('SJIS'); // Start buffering and specify "mb_output_handler" as // callback function ob_start('mb_output_handler'); ?>

Supported Character Encodings

Currently, the following character encoding is supported by the mbstring module. Character encoding may be specified for mbstring functions' encoding parameter.

The following character encoding is supported in this PHP extension:

UCS-4, UCS-4BE, UCS-4LE, UCS-2, UCS-2BE, UCS-2LE, UTF-32, UTF-32BE, UTF-32LE, UCS-2LE, UTF-16, UTF-16BE, UTF-16LE, UTF-8, UTF-7, ASCII, EUC-JP, SJIS, eucJP-win, SJIS-win, ISO-2022-JP, JIS, ISO-8859-1, ISO-8859-2, ISO-8859-3, ISO-8859-4, ISO-8859-5, ISO-8859-6, ISO-8859-7, ISO-8859-8, ISO-8859-9, ISO-8859-10, ISO-8859-13, ISO-8859-14, ISO-8859-15, byte2be, byte2le, byte4be, byte4le, BASE64, 7bit, 8bit and UTF7-IMAP.

As of PHP 4.3.0, the following character encoding support will be added experimentaly : EUC-CN, CP936, HZ, EUC-TW, CP950, BIG-5, EUC-KR, UHC (CP949), ISO-2022-KR, Windows-1251 (CP1251), Windows-1252 (CP1252), CP866, KOI8-R.

php.ini entry, which accepts encoding name, accepts "auto" and "pass" also. mbstring functions, which accepts encoding name, and accepts "auto".

If "pass" is set, no character encoding conversion is performed.

If "auto" is set, it is expanded to "ASCII,JIS,UTF-8,EUC-JP,SJIS".

Overloading PHP string functions with multi byte string functions

Because almost PHP application written for language using single-byte character encoding, there are some difficulties for multibyte string handling including japanese. Almost PHP string functions such as substr() do not support multibyte string.

Multibyte extension (mbstring) has some PHP string functions with multibyte support (ex. substr() supports mb_substr()).

Multibyte extension (mbstring) also supports 'function overloading' to add multibyte string functionality without code modification. Using function overloading, some PHP string functions will be oveloaded multibyte string functions. For example, mb_substr() is called instead of substr() if function overloading is enabled. Function overload makes easy to port application supporting only single-byte encoding for multibyte application.

mbstring.func_overload in php.ini should be set some positive value to use function overloading. The value should specify the category of overloading functions, sbould be set 1 to enable mail function overloading. 2 to enable string functions, 4 to regular expression functions. For example, if is set for 7, mail, strings, regex functions should be overloaded. The list of overloaded functions are shown in below.

Table 2. Functions to be overloaded

value of mbstring.func_overload	original function	overloaded function
1	mail()	mb_send_mail()
2	strlen()	mb_strlen()
2	strpos()	mb_strpos()
2	strrpos()	mb_strrpos()
2	substr()	mb_substr()
4	ereg()	mb_ereg()
4	eregi()	mb_eregi()
4	ereg_replace()	mb_ereg_replace()
4	eregi_replace()	mb_eregi_replace()
4	split()	mb_split()

Basics of Japanese multi-byte characters

Most Japanese characters need more than 1 byte per character. In addition, several character encoding schemas are used under a Japanese environment. There are EUC-JP, Shift_JIS(SJIS) and ISO-2022-JP(JIS) character encoding. As Unicode becomes popular, UTF-8 is used also. To develop Web applications for a Japanese environment, it is important to use the character set for the task in hand, whether HTTP input/output, RDBMS and E-mail.

Storage for a character can be up to six bytes
A multi-byte character is usually twice of the width compared to single-byte characters. Wider characters are called "zen-kaku" - meaning full width, narrower characters are called "han-kaku" - meaning half width. "zen-kaku" characters are usually fixed width.
Some character encoding defines shift(escape) sequence for entering/exiting multi-byte character strings.
ISO-2022-JP must be used for SMTP/NNTP.
"i-mode" web site is supposed to use SJIS.

References

Multi-byte character encoding and its related issues are very complex. It is impossible to cover in sufficient detail here. Please refer to the following URLs and other resources for further readings.

Unicode/UTF/UCS/etc
http://www.unicode.org/
Japanese/Korean/Chinese character information
ftp://ftp.ora.com/pub/examples/nutshell/ujip/doc/cjk.inf

Table of Contents
mb_convert_encoding -- Convert character encoding
mb_convert_kana -- Convert "kana" one from another ("zen-kaku" ,"han-kaku" and more)
mb_convert_variables -- Convert character code in variable(s)
mb_decode_mimeheader -- Decode string in MIME header field
mb_decode_numericentity -- Decode HTML numeric string reference to character
mb_detect_encoding -- Detect character encoding
mb_detect_order -- Set/Get character encoding detection order
mb_encode_mimeheader -- Encode string for MIME header
mb_encode_numericentity -- Encode character to HTML numeric string reference
mb_ereg_match -- Regular expression match for multibyte string
mb_ereg_replace -- Replace regular expression with multibyte support
mb_ereg_search_getpos -- Returns start point for next regular expression match
mb_ereg_search_getregs -- Retrive the result from the last multibyte regular expression match
mb_ereg_search_init -- Setup string and regular expression for multibyte regular expression match
mb_ereg_search_pos -- Return position and length of matched part of multibyte regular expression for predefined multibyte string
mb_ereg_search_regs -- Returns the matched part of multibyte regular expression
mb_ereg_search_setpos -- Set start point of next regular expression match
mb_ereg_search -- Multibyte regular expression match for predefined multibyte string
mb_ereg -- Regular expression match with multibyte support
mb_eregi_replace -- Replace regular expression with multibyte support ignoring case
mb_eregi -- Regular expression match ignoring case with multibyte support
mb_get_info -- Get internal settings of mbstring
mb_http_input -- Detect HTTP input character encoding
mb_http_output -- Set/Get HTTP output character encoding
mb_internal_encoding -- Set/Get internal character encoding
mb_language -- Set/Get current language
mb_output_handler -- Callback function converts character encoding in output buffer
mb_parse_str -- Parse GET/POST/COOKIE data and set global variable
mb_preferred_mime_name -- Get MIME charset string
mb_regex_encoding -- Returns current encoding for multibyte regex as string
mb_regex_set_options -- Set/Get the default options for mbregex functions
mb_send_mail -- Send encoded mail.
mb_split -- Split multibyte string using regular expression
mb_strcut -- Get part of string
mb_strimwidth -- Get truncated string with specified width
mb_strlen -- Get string length
mb_strpos -- Find position of first occurrence of string in a string
mb_strrpos -- Find position of last occurrence of a string in a string
mb_strwidth -- Return width of string
mb_substitute_character -- Set/Get substitution character
mb_substr -- Get part of string

mb_convert_encoding

(PHP 4 >= 4.0.6)

mb_convert_encoding -- Convert character encoding

Description

array mb_detect_order ( [mixed encoding-list])

mb_detect_order() sets automatic character encoding detection order to encoding-list. It returns TRUE for success, FALSE for failure.

encoding-list is array or comma separated list of character encoding. ("auto" is expanded to "ASCII, JIS, UTF-8, EUC-JP, SJIS")

If encoding-list is omitted, it returns current character encoding detection order as array.

This setting affects mb_detect_encoding() and mb_send_mail().

Note: mbstring currently implements following encoding detection filters. If there is a invalid byte sequence for following encoding, encoding detection will fail.
Note: UTF-8, UTF-7, ASCII, EUC-JP,SJIS, eucJP-win, SJIS-win, JIS, ISO-2022-JP
For ISO-8859-*, mbstring always detects as ISO-8859-*.
For UTF-16, UTF-32, UCS2 and UCS4, encoding detection will fail always.
Example 1. Useless detect order example
; Always detect as ISO-8859-1
detect_order = ISO-8859-1, UTF-8

; Always detect as UTF-8, since ASCII/UTF-7 values are 
; valid for UTF-8
detect_order = UTF-8, ASCII, UTF-7

Example 2. mb_detect_order() examples
/* Set detection order by enumerated list */ mb_detect_order("eucjp-win,sjis-win,UTF-8"); /* Set detection order by array */ $ary[] = "ASCII"; $ary[] = "JIS"; $ary[] = "EUC-JP"; mb_detect_order($ary); /* Display current detection order */ echo implode(", ", mb_detect_order());

mb_encode_mimeheader

(PHP 4 >= 4.0.6)

mb_encode_mimeheader -- Encode string for MIME header

Description

string mb_encode_mimeheader ( string str [, string charset [, string transfer-encoding [, string linefeed]]])

string mb_ereg_replace ( string pattern, string replacement, string string [, array option])

Warning

mb_ereg_replace() scans string for matches to pattern, then replaces the matched text with replacement and returns the result string or FALSE on error. Multibyte character can be used in pattern.

Matching condition can be set by option parameter. If i is specified for this parameter, the case will be ignored. If x is specified, white space will be ignored. If m is specified, match will be executed in multiline mode and line break will be included in '.'. If p is specified, match will be executed in POSIX mode, line break will be considered as normal character. If e is specified, replacement string will be evaluated as PHP expression.

The internal encoding or the character encoding specified in mb_regex_encoding() will be used as character encoding.

Note: This function is supported in PHP 4.2.0 or higher.

mb_ereg_search_getpos

(PHP 4 >= 4.2.0)

mb_ereg_search_getpos -- Returns start point for next regular expression match

Description

array mb_ereg_search_getpos ( void)

Warning

mb_ereg_search_getpos() returns the point to start regular expression match for mb_ereg_search(), mb_ereg_search_pos(), mb_ereg_search_regs(). The position is represented by bytes from the head of string.

The internal encoding or the character encoding specified in mb_regex_encoding() will be used as character encoding.

Note: This function is supported in PHP 4.2.0 or higher.

mb_ereg_search_getregs

(PHP 4 >= 4.2.0)

mb_ereg_search_getregs -- Retrive the result from the last multibyte regular expression match

Description

array mb_ereg_search_getregs ( void)

Warning

mb_ereg_search_getregs() returns an array including the sub-string of matched part by last mb_ereg_search(), mb_ereg_search_pos(), mb_ereg_search_regs(). If there are some maches, the first element will have the matched sub-string, the second element will have the first part grouped with brackets, the third element will have the second part grouped with brackets, and so on. It returns FALSE on error;

The internal encoding or the character encoding specified in mb_regex_encoding() will be used as character encoding.

Note: This function is supported in PHP 4.2.0 or higher.

mb_ereg_search_init

(PHP 4 >= 4.2.0)

mb_ereg_search_init -- Setup string and regular expression for multibyte regular expression match

Description

array mb_ereg_search_init ( string string [, string pattern [, string option]])

Warning

mb_ereg_search_init() sets string and pattern for multibyte regular expression. These values are used for mb_ereg_search(), mb_ereg_search_pos(), mb_ereg_search_regs(). It returns TRUE for success, FALSE for error.

The internal encoding or the character encoding specified in mb_regex_encoding() will be used as character encoding.

Note: This function is supported in PHP 4.2.0 or higher.

mb_ereg_search_pos

(PHP 4 >= 4.2.0)

mb_ereg_search_pos -- Return position and length of matched part of multibyte regular expression for predefined multibyte string

Description

array mb_ereg_search_pos ( [string pattern [, string option]])

Warning

mb_ereg_search_pos() returns an array including position of matched part for multibyte regular expression. The first element of the array will be the beggining of matched part, the second element will be length (bytes) of matched part. It returns FALSE on error.

The string for match is specified by mb_ereg_search_init(). It it is not specified, the previous one will be used.

The internal encoding or the character encoding specified in mb_regex_encoding() will be used as character encoding.

Note: This function is supported in PHP 4.2.0 or higher.

mb_ereg_search_regs

(PHP 4 >= 4.2.0)

mb_ereg_search_regs -- Returns the matched part of multibyte regular expression

Description

array mb_ereg_search_regs ( [string pattern [, string option]])

Warning

mb_ereg_search_regs() executes the multibyte regular expression match, and if there are some matched part, it returns an array including substring of matched part as first element, the first grouped part with brackets as second element, the second grouped part as third element, and so on. It returns FALSE on error.

The internal encoding or the character encoding specified in mb_regex_encoding() will be used as character encoding.

Note: This function is supported in PHP 4.2.0 or higher.

mb_ereg_search_setpos

(PHP 4 >= 4.2.0)

mb_ereg_search_setpos -- Set start point of next regular expression match

Description

array mb_ereg_search_setpos ( void)

Warning

mb_ereg_search_setpos() sets the starting point of match for mb_ereg_search().

The internal encoding or the character encoding specified in mb_regex_encoding() will be used as character encoding.

Note: This function is supported in PHP 4.2.0 or higher.

mb_ereg_search

(PHP 4 >= 4.2.0)

mb_ereg_search -- Multibyte regular expression match for predefined multibyte string

Description

bool mb_ereg_search ( [string pattern [, string option]])

Warning

mb_ereg_search() returns TRUE if the multibyte string matches with the regular expression, FALSE for otherwise. The string for matching is set by mb_ereg_search_init(). If pattern is not specified, the previous one is used.

The internal encoding or the character encoding specified in mb_regex_encoding() will be used as character encoding.

Note: This function is supported in PHP 4.2.0 or higher.

mb_ereg

(PHP 4 >= 4.2.0)

mb_ereg -- Regular expression match with multibyte support

Description

int mb_ereg ( string pattern, string string [, array regs])

Warning

mb_ereg() executes the regular expression match with multibyte support, and returns 1 if matches are found. If the optional third parameter was specified, the function returns the byte length of matched part, and therarray regs will contain the substring of matched string. The functions returns 1 if it matches with the empty string. It no matche found or error happend, FALSE will be returned.

The internal encoding or the character encoding specified in mb_regex_encoding() will be used as character encoding.

Note: This function is supported in PHP 4.2.0 or higher.

mb_eregi_replace

(PHP 4 >= 4.2.0)

mb_eregi_replace -- Replace regular expression with multibyte support ignoring case

Description

string mb_eregi_replace ( string pattern, string replace, string string)

Warning

The internal encoding or the character encoding specified in mb_regex_encoding() will be used as character encoding.

Note: This function is supported in PHP 4.2.0 or higher.

mb_eregi

(PHP 4 >= 4.2.0)

mb_eregi -- Regular expression match ignoring case with multibyte support

Description

int mb_eregi ( string pattern, string string [, array regs])

Warning

mb_eregi() executes the regular expression match with multibyte support, and returns 1 if matches are found. This function ignore case. If the optional third parameter was specified, the function returns the byte length of matched part, and therarray regs will contain the substring of matched string. The functions returns 1 if it matches with the empty string. It no matche found or error happend, FALSE will be returned.

The internal encoding or the character encoding specified in mb_regex_encoding() will be used as character encoding.

Note: This function is supported in PHP 4.2.0 or higher.

mb_get_info

(PHP 4 >= 4.2.0)

mb_get_info -- Get internal settings of mbstring

Description

string mb_get_info ( [string type])

Warning

mb_get_info() returns internal setting parameter of mbstring.

If type isn't specified or is specified to "all", an array having the elements "internal_encoding", "http_output", "http_input", "func_overload" will be returned.

If type is specified for "http_output", "http_input", "internal_encoding", "func_overload", the specified setting parameter will be returned.

mb_http_input

(PHP 4 >= 4.0.6)

mb_http_input -- Detect HTTP input character encoding

Description

string mb_http_input ( [string type])

mb_http_input() returns result of HTTP input character encoding detection.

type: Input string specifies input type. "G" for GET, "P" for POST, "C" for COOKIE. If type is omitted, it returns last input type processed.

Return Value: Character encoding name. If mb_http_input() does not process specified HTTP input, it returns FALSE.

mb_http_output

(PHP 4 >= 4.0.6)

mb_http_output -- Set/Get HTTP output character encoding

Description

string mb_http_output ( [string encoding])

If encoding is set, mb_http_output() sets HTTP output character encoding to encoding. Output after this function is converted to encoding. mb_http_output() returns TRUE for success and FALSE for failure.

If encoding is omitted, mb_http_output() returns current HTTP output character encoding.

mb_internal_encoding

(PHP 4 >= 4.0.6)

mb_internal_encoding -- Set/Get internal character encoding

Description

string mb_internal_encoding ( [string encoding])

mb_internal_encoding() sets internal character encoding to encoding If parameter is omitted, it returns current internal encoding.

encoding is used for HTTP input character encoding conversion, HTTP output character encoding conversion and default character encoding for string functions defined by mbstring module.

encoding: Character encoding name

Return Value: If encoding is set,mb_internal_encoding() returns TRUE for success, otherwise returns FALSE. If encoding is omitted, it returns current character encoding name.

Example 1. mb_internal_encoding() example
/* Set internal character encoding to UTF-8 */ mb_internal_encoding("UTF-8"); /* Display current internal character encoding */ echo mb_internal_encoding();

mb_language

(PHP 4 >= 4.0.6)

mb_language -- Set/Get current language

Description

string mb_language ( [string language])

mb_language() sets language. If language is omitted, it returns current language as string.

language setting is used for encoding e-mail messages. Valid languages are "Japanese", "ja","English","en" and "uni" (UTF-8). mb_send_mail() uses this setting to encode e-mail.

Language and its setting is ISO-2022-JP/Base64 for Japanese, UTF-8/Base64 for uni, ISO-8859-1/quoted printable for English.

Return Value: If language is set and language is valid, it returns TRUE. Otherwise, it returns FALSE. When language is omitted, it returns language name as string. If no language is set previously, it returns FALSE.

mb_output_handler

(PHP 4 >= 4.0.6)

mb_output_handler -- Callback function converts character encoding in output buffer

Description

string mb_output_handler ( string contents, int status)

mb_output_handler() is ob_start() callback function. mb_output_handler() converts characters in output buffer from internal character encoding to HTTP output character encoding.

4.1.0 or later version, this hanlder adds charset HTTP header when following conditions are met:

Does not set Content-Type by header()
Default MIME type begins with text/
http_output setting is other than pass

contents : Output buffer contents

status : Output buffer status

Return Value: String converted

Example 1. mb_output_handler() example
mb_http_output("UTF-8"); ob_start("mb_output_handler");

Note: If you want to output some binary data such as image from PHP script, you must set output encoding to "pass" using mb_http_output().

mb_parse_str

(PHP 4 >= 4.0.6)

mb_parse_str -- Parse GET/POST/COOKIE data and set global variable

Description

boolean mb_parse_str ( string encoded_string [, array result])

mb_parse_str() parses GET/POST/COOKIE data and sets global variables. Since PHP does not provide raw POST/COOKIE data, it can only used for GET data for now. It preses URL encoded data, detects encoding, converts coding to internal encoding and set values to result array or global variables.

encoded_string: URL encoded data.

result: Array contains decoded and character encoding converted values.

Return Value: It returns TRUE for success or FALSE for failure.

mb_preferred_mime_name

(PHP 4 >= 4.0.6)

mb_preferred_mime_name -- Get MIME charset string

Description

string mb_preferred_mime_name ( string encoding)

mb_preferred_mime_name() returns MIME charset string for character encoding encoding. It returns charset string.

Example 1. mb_preferred_mime_string() example
$outputenc = "sjis-win"; mb_http_output($outputenc); ob_start("mb_output_handler"); header("Content-Type: text/html; charset=" . mb_preferred_mime_name($outputenc));

mb_regex_encoding

(PHP 4 >= 4.2.0)

mb_regex_encoding -- Returns current encoding for multibyte regex as string

Description

string mb_regex_encoding ( [string encoding])

Warning

mb_regex_encoding() returns the character encoding used by multibyte regex functions.

If the optional parameter encoding is specified, it is set to the character encoding for multibyte regex. The default value is the internal character encoding.

Note: This function is supported in PHP 4.2.0 or higher.

mb_regex_set_options

(no version information, might be only in CVS)

mb_regex_set_options -- Set/Get the default options for mbregex functions

Description

string mb_regex_set_options ( [string options])

Warning

mb_regex_set_options() sets the default options described by options for multibyte regex functions.

Returns the previous options. If options is omitted, it returns the string that describes the current options.

Note: This function is supported in PHP 4.3.0 or higher.

mb_send_mail

(PHP 4 >= 4.0.6)

mb_send_mail -- Send encoded mail.

Description

boolean mb_send_mail ( string to, string subject, string message [, string additional_headers [, string additional_parameter]])

mb_send_mail() sends email. Headers and message are converted and encoded according to mb_language() setting. mb_send_mail() is wrapper function of mail(). See mail() for details.

to is mail addresses send to. Multiple recipients can be specified by putting a comma between each address in to. This parameter is not automatically encoded.

subject is subject of mail.

message is mail message.

additional_headers is inserted at the end of the header. This is typically used to add extra headers. Multiple extra headers are separated with a newline ("\n").

additional_parameter is a MTA command line parameter. It is useful when setting the correct Return-Path header when using sendmail.

Returns TRUE on success or FALSE on failure.

mb_split

(PHP 4 >= 4.2.0)

mb_split -- Split multibyte string using regular expression

Description

array mb_split ( string pattern, string string [, int limit])

Warning

mb_split() split multibyte string using regular expression pattern and returns the result as an array.

If optional parameter limit is specified, it will be split in limit elements as maximum.

The internal encoding or the character encoding specified in mb_regex_encoding() will be used as character encoding.

Note: This function is supported in PHP 4.2.0 or higher.

mb_strcut

(PHP 4 >= 4.0.6)

mb_strcut -- Get part of string

Description

string mb_strcut ( string str, int start [, int length [, string encoding]])

mb_strcut() returns the portion of str specified by the start and length parameters.

mb_strcut() performs equivalent operation as mb_substr() with different method. If start position is multi-byte character's second byte or larger, it starts from first byte of multi-byte character.

It subtracts string from str that is shorter than length AND character that is not part of multi-byte string or not being middle of shift sequence.

encoding is character encoding. If it is not set, internal character encoding is used.

mb_strimwidth

(PHP 4 >= 4.0.6)

mb_strimwidth -- Get truncated string with specified width

Description

string mb_strimwidth ( string str, int start, int width, string trimmarker [, string encoding])

mb_strimwidth() truncates string str to specified width. It returns truncated string.

If trimmarker is set, trimmarker is appended to return value.

start is start position offset. Number of characters from the beginning of string. (First character is 0)

trimmarker is string that is added to the end of string when string is truncated.

encoding is character encoding. If it is omitted, internal encoding is used.

Example 1. mb_strimwidth() example
$str = mb_strimwidth($str, 0, 40, "..>");

mb_strlen

(PHP 4 >= 4.0.6)

mb_strlen -- Get string length

Description

string mb_strlen ( string str [, string encoding])

mb_strlen() returns number of characters in string str having character encoding encoding. A multi-byte character is counted as 1.

encoding is character encoding for str. If encoding is omitted, internal character encoding is used.

mb_strpos

(PHP 4 >= 4.0.6)

mb_strpos -- Find position of first occurrence of string in a string

Description

int mb_strpos ( string haystack, string needle [, int offset [, string encoding]])

mb_strpos() returns the numeric position of the first occurrence of needle in the haystack string. If needle is not found, it returns FALSE.

mixed mb_substitute_character ( [mixed substrchar])

mb_substitute_character() specifies substitution character when input character encoding is invalid or character code is not exist in output character encoding. Invalid characters may be substituted NULL(no output), string or integer value (Unicode character code value).

This setting affects mb_detect_encoding() and mb_send_mail().

substchar : Specify Unicode value as integer or specify as string as follows

"none" : no output
"long" : Output character code value (Example: U+3000,JIS+7E7E)

Return Value: If substchar is set, it returns TRUE for success, otherwise returns FALSE. If substchar is not set, it returns Unicode value or "none"/"long".

Example 1. mb_substitute_character() example
/* Set with Unicode U+3013 (GETA MARK) */ mb_substitute_character(0x3013); /* Set hex format */ mb_substitute_character("long"); /* Display current setting */ echo mb_substitute_character();

mb_substr

(PHP 4 >= 4.0.6)

mb_substr -- Get part of string

Description

string mb_substr ( string str, int start [, int length [, string encoding]])

mb_substr() returns the portion of str specified by the start and length parameters.

mb_substr() performs multi-byte safe substr() operation based on number of characters. Position is counted from the beginning of str. First character's position is 0. Second character position is 1, and so on.

If encoding is omitted, internal encoding is assumed.

encoding is character encoding. If it is omitted, internal character encoding is used.

LIII. MCAL functions

Introduction

MCAL stands for Modular Calendar Access Library.

Libmcal is a C library for accessing calendars. It's written to be very modular, with pluggable drivers. MCAL is the calendar equivalent of the IMAP module for mailboxes.

With mcal support, a calendar stream can be opened much like the mailbox stream with the IMAP support. Calendars can be local file stores, remote ICAP servers, or other formats that are supported by the mcal library.

Calendar events can be pulled up, queried, and stored. There is also support for calendar triggers (alarms) and recurring events.

With libmcal, central calendar servers can be accessed, removing the need for any specific database or local file programming.

Most of the functions use an internal event structure that is unique for each stream. This alleviates the need to pass around large objects between functions. There are convenience functions for setting, initializing, and retrieving the event structure values.

Note: PHP had an ICAP extension previously, but the original library and the PHP extension is not supported anymore. The suggested replacement is MCAL.

Requirements

This extension requires the mcal library to be installed. Grab the latest version from http://mcal.chek.com/ and compile and install it.

Installation

After you installed the mcal library, to get these functions to work, you have to compile PHP with --with-mcal.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

MCAL_SUNDAY (integer)
MCAL_MONDAY (integer)
MCAL_TUESDAY (integer)
MCAL_WEDNESDAY (integer)
MCAL_THURSDAY (integer)
MCAL_FRIDAY (integer)
MCAL_SATURDAY (integer)
MCAL_JANUARY (integer)
MCAL_FEBRUARY (integer)
MCAL_MARCH (integer)
MCAL_APRIL (integer)
MCAL_MAY (integer)
MCAL_JUNE (integer)
MCAL_JULY (integer)
MCAL_AUGUST (integer)
MCAL_SEPTEMBER (integer)
MCAL_OCTOBER (integer)
MCAL_NOVEMBER (integer)
MCAL_DECEMBER (integer)
MCAL_RECUR_NONE (integer)
MCAL_RECUR_DAILY (integer)
MCAL_RECUR_WEEKLY (integer)
MCAL_RECUR_MONTHLY_MDAY (integer)
MCAL_RECUR_MONTHLY_WDAY (integer)
MCAL_RECUR_YEARLY (integer)
MCAL_M_SUNDAY (integer)
MCAL_M_MONDAY (integer)
MCAL_M_TUESDAY (integer)
MCAL_M_WEDNESDAY (integer)
MCAL_M_THURSDAY (integer)
MCAL_M_FRIDAY (integer)
MCAL_M_SATURDAY (integer)
MCAL_M_WEEKDAYS (integer)
MCAL_M_WEEKEND (integer)
MCAL_M_ALLDAYS (integer)

Table of Contents
mcal_append_event -- Store a new event into an MCAL calendar
mcal_close -- Close an MCAL stream
mcal_create_calendar -- Create a new MCAL calendar
mcal_date_compare -- Compares two dates
mcal_date_valid -- Returns TRUE if the given year, month, day is a valid date
mcal_day_of_week -- Returns the day of the week of the given date
mcal_day_of_year -- Returns the day of the year of the given date
mcal_days_in_month -- Returns the number of days in the given month
mcal_delete_calendar -- Delete an MCAL calendar
mcal_delete_event -- Delete an event from an MCAL calendar
mcal_event_add_attribute -- Adds an attribute and a value to the streams global event structure
mcal_event_init -- Initializes a streams global event structure
mcal_event_set_alarm -- Sets the alarm of the streams global event structure
mcal_event_set_category -- Sets the category of the streams global event structure
mcal_event_set_class -- Sets the class of the streams global event structure
mcal_event_set_description -- Sets the description of the streams global event structure
mcal_event_set_end -- Sets the end date and time of the streams global event structure
mcal_event_set_recur_daily -- Sets the recurrence of the streams global event structure
mcal_event_set_recur_monthly_mday -- Sets the recurrence of the streams global event structure
mcal_event_set_recur_monthly_wday -- Sets the recurrence of the streams global event structure
mcal_event_set_recur_none -- Sets the recurrence of the streams global event structure
mcal_event_set_recur_weekly -- Sets the recurrence of the streams global event structure
mcal_event_set_recur_yearly -- Sets the recurrence of the streams global event structure
mcal_event_set_start -- Sets the start date and time of the streams global event structure
mcal_event_set_title -- Sets the title of the streams global event structure
mcal_expunge -- Deletes all events marked for being expunged.
mcal_fetch_current_stream_event -- Returns an object containing the current streams event structure
mcal_fetch_event -- Fetches an event from the calendar stream
mcal_is_leap_year -- Returns if the given year is a leap year or not
mcal_list_alarms -- Return a list of events that has an alarm triggered at the given datetime
mcal_list_events -- Return a list of IDs for a date or a range of dates.
mcal_next_recurrence -- Returns the next recurrence of the event
mcal_open -- Opens up an MCAL connection
mcal_popen -- Opens up a persistent MCAL connection
mcal_rename_calendar -- Rename an MCAL calendar
mcal_reopen -- Reopens an MCAL connection
mcal_snooze -- Turn off an alarm for an event
mcal_store_event -- Modify an existing event in an MCAL calendar
mcal_time_valid -- Returns TRUE if the given year, month, day is a valid time
mcal_week_of_year -- Returns the week number of the given date

mcal_append_event

(PHP 4 )

mcal_append_event -- Store a new event into an MCAL calendar

Description

int mcal_delete_event ( int mcal_stream [, int event_id])

mcal_delete_event() deletes the calendar event specified by the event_id.

Returns TRUE.

mcal_event_add_attribute

(PHP 3>= 3.0.15, PHP 4 )

mcal_event_add_attribute -- Adds an attribute and a value to the streams global event structure

int mcal_event_set_start ( int stream, int year, int month [, int day [, int hour [, int min [, int sec]]]])

mcal_event_set_start() sets the streams global event structure's start date and time to the given values.

Returns TRUE.

mcal_event_set_title

(PHP 3>= 3.0.13, PHP 4 )

mcal_event_set_title -- Sets the title of the streams global event structure

Description

int mcal_event_set_title ( int stream, string title)

mcal_event_set_title() sets the streams global event structure's title to the given string.

Returns TRUE.

mcal_expunge

object mcal_fetch_event ( int mcal_stream, int event_id [, int options])

mcal_fetch_event() fetches an event from the calendar stream specified by id.

Returns an event object consisting of:

int id - ID of that event.
int public - TRUE if the event if public, FALSE if it is private.
string category - Category string of the event.
string title - Title string of the event.
string description - Description string of the event.
int alarm - number of minutes before the event to send an alarm/reminder.
object start - Object containing a datetime entry.
object end - Object containing a datetime entry.
int recur_type - recurrence type
int recur_interval - recurrence interval
datetime recur_enddate - recurrence end date
int recur_data - recurrence data

All datetime entries consist of an object that contains:

int year - year
int month - month
int mday - day of month
int hour - hour
int min - minutes
int sec - seconds
int alarm - minutes before event to send an alarm

The possible values for recur_type are:

0 - Indicates that this event does not recur
1 - This event recurs daily
2 - This event recurs on a weekly basis
3 - This event recurs monthly on a specific day of the month (e.g. the 10th of the month)
4 - This event recurs monthly on a sequenced day of the week (e.g. the 3rd Saturday)
5 - This event recurs on an annual basis

mcal_is_leap_year

(PHP 3>= 3.0.13, PHP 4 )

mcal_is_leap_year -- Returns if the given year is a leap year or not

mcal_week_of_year

(PHP 4 )

mcal_week_of_year -- Returns the week number of the given date

Description

int mcal_week_of_year ( int day, int month, int year)

LIV. Mcrypt Encryption Functions

Introduction

This is an interface to the mcrypt library, which supports a wide variety of block algorithms such as DES, TripleDES, Blowfish (default), 3-WAY, SAFER-SK64, SAFER-SK128, TWOFISH, TEA, RC2 and GOST in CBC, OFB, CFB and ECB cipher modes. Additionally, it supports RC6 and IDEA which are considered "non-free".

Requirements

These functions work using mcrypt.

If you linked against libmcrypt 2.4.x or higher, the following additional block algorithms are supported: CAST, LOKI97, RIJNDAEL, SAFERPLUS, SERPENT and the following stream ciphers: ENIGMA (crypt), PANAMA, RC4 and WAKE. With libmcrypt 2.4.x or higher another cipher mode is also available; nOFB.

Installation

To use it, download libmcrypt-x.x.tar.gz from here and follow the included installation instructions. You need to compile PHP with the --with-mcrypt parameter to enable this extension. Make sure you compile libmcrypt with the option --disable-posix-threads.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Mcrypt configuration options

Name	Default	Changeable
mcrypt.algorithms_dir	NULL	PHP_INI_ALL
mcrypt.modes_dir	NULL	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

Mcrypt can operate in four block cipher modes (CBC, OFB, CFB, and ECB). If linked against libmcrypt-2.4.x or higher the functions can also operate in the block cipher mode nOFB and in STREAM mode. Below you find a list with all supported encryption modes together with the constants that are defines for the encryption mode. For a more complete reference and discussion see Applied Cryptography by Schneier (ISBN 0-471-11709-9).

MCRYPT_MODE_ECB (electronic codebook) is suitable for random data, such as encrypting other keys. Since data there is short and random, the disadvantages of ECB have a favorable negative effect.
MCRYPT_MODE_CBC (cipher block chaining) is especially suitable for encrypting files where the security is increased over ECB significantly.
MCRYPT_MODE_CFB (cipher feedback) is the best mode for encrypting byte streams where single bytes must be encrypted.
MCRYPT_MODE_OFB (output feedback, in 8bit) is comparable to CFB, but can be used in applications where error propagation cannot be tolerated. It's insecure (because it operates in 8bit mode) so it is not recommended to use it.
MCRYPT_MODE_NOFB (output feedback, in nbit) is comparable to OFB, but more secure because it operates on the block size of the algorithm.
MCRYPT_MODE_STREAM is an extra mode to include some stream algorithms like WAKE or RC4.

Some other mode and random device constants:

MCRYPT_ENCRYPT (integer)
MCRYPT_DECRYPT (integer)
MCRYPT_DEV_RANDOM (integer)
MCRYPT_DEV_URANDOM (integer)
MCRYPT_RAND (integer)

Mcrypt ciphers

Here is a list of ciphers which are currently supported by the mcrypt extension. For a complete list of supported ciphers, see the defines at the end of mcrypt.h. The general rule with the mcrypt-2.2.x API is that you can access the cipher from PHP with MCRYPT_ciphername. With the libmcrypt-2.4.x and libmcrypt-2.5.x API these constants also work, but it is possible to specify the name of the cipher as a string with a call to mcrypt_module_open().

MCRYPT_3DES
MCRYPT_ARCFOUR_IV (libmcrypt > 2.4.x only)
MCRYPT_ARCFOUR (libmcrypt > 2.4.x only)
MCRYPT_BLOWFISH
MCRYPT_CAST_128
MCRYPT_CAST_256
MCRYPT_CRYPT
MCRYPT_DES
MCRYPT_DES_COMPAT (libmcrypt 2.2.x only)
MCRYPT_ENIGMA (libmcrypt > 2.4.x only, alias for MCRYPT_CRYPT)
MCRYPT_GOST
MCRYPT_IDEA (non-free)
MCRYPT_LOKI97 (libmcrypt > 2.4.x only)
MCRYPT_MARS (libmcrypt > 2.4.x only, non-free)
MCRYPT_PANAMA (libmcrypt > 2.4.x only)
MCRYPT_RIJNDAEL_128 (libmcrypt > 2.4.x only)
MCRYPT_RIJNDAEL_192 (libmcrypt > 2.4.x only)
MCRYPT_RIJNDAEL_256 (libmcrypt > 2.4.x only)
MCRYPT_RC2
MCRYPT_RC4 (libmcrypt 2.2.x only)
MCRYPT_RC6 (libmcrypt > 2.4.x only)
MCRYPT_RC6_128 (libmcrypt 2.2.x only)
MCRYPT_RC6_192 (libmcrypt 2.2.x only)
MCRYPT_RC6_256 (libmcrypt 2.2.x only)
MCRYPT_SAFER64
MCRYPT_SAFER128
MCRYPT_SAFERPLUS (libmcrypt > 2.4.x only)
MCRYPT_SERPENT(libmcrypt > 2.4.x only)
MCRYPT_SERPENT_128 (libmcrypt 2.2.x only)
MCRYPT_SERPENT_192 (libmcrypt 2.2.x only)
MCRYPT_SERPENT_256 (libmcrypt 2.2.x only)
MCRYPT_SKIPJACK (libmcrypt > 2.4.x only)
MCRYPT_TEAN (libmcrypt 2.2.x only)
MCRYPT_THREEWAY
MCRYPT_TRIPLEDES (libmcrypt > 2.4.x only)
MCRYPT_TWOFISH (for older mcrypt 2.x versions, or mcrypt > 2.4.x )
MCRYPT_TWOFISH128 (TWOFISHxxx are available in newer 2.x versions, but not in the 2.4.x versions)
MCRYPT_TWOFISH192
MCRYPT_TWOFISH256
MCRYPT_WAKE (libmcrypt > 2.4.x only)
MCRYPT_XTEA (libmcrypt > 2.4.x only)

You must (in CFB and OFB mode) or can (in CBC mode) supply an initialization vector (IV) to the respective cipher function. The IV must be unique and must be the same when decrypting/encrypting. With data which is stored encrypted, you can take the output of a function of the index under which the data is stored (e.g. the MD5 key of the filename). Alternatively, you can transmit the IV together with the encrypted data (see chapter 9.3 of Applied Cryptography by Schneier (ISBN 0-471-11709-9) for a discussion of this topic).

Examples

Mcrypt can be used to encrypt and decrypt using the above mentioned ciphers. If you linked against libmcrypt-2.2.x, the four important mcrypt commands (mcrypt_cfb(), mcrypt_cbc(), mcrypt_ecb(), and mcrypt_ofb()) can operate in both modes which are named MCRYPT_ENCRYPT and MCRYPT_DECRYPT, respectively.
Example 1. Encrypt an input value with TripleDES under 2.2.x in ECB mode
<?php $key = "this is a very secret key"; $input = "Let us meet at 9 o'clock at the secret place."; $encrypted_data = mcrypt_ecb (MCRYPT_3DES, $key, $input, MCRYPT_ENCRYPT); ?>
This example will give you the encrypted data as a string in $encrypted_data.

If you linked against libmcrypt 2.4.x or 2.5.x, these functions are still available, but it is recommended that you use the advanced functions.
Example 2. Encrypt an input value with TripleDES under 2.4.x and higher in ECB mode
<?php $key = "this is a very secret key"; $input = "Let us meet at 9 o'clock at the secret place."; $td = mcrypt_module_open ('tripledes', '', 'ecb', ''); $iv = mcrypt_create_iv (mcrypt_enc_get_iv_size ($td), MCRYPT_RAND); mcrypt_generic_init ($td, $key, $iv); $encrypted_data = mcrypt_generic ($td, $input); mcrypt_generic_end ($td); ?>
This example will give you the encrypted data as a string in $encrypted_data. For a full example see mcrypt_module_open().

Table of Contents
mcrypt_cbc -- Encrypt/decrypt data in CBC mode
mcrypt_cfb -- Encrypt/decrypt data in CFB mode
mcrypt_create_iv -- Create an initialization vector (IV) from a random source
mcrypt_decrypt -- Decrypts crypttext with given parameters
mcrypt_ecb -- Encrypt/decrypt data in ECB mode
mcrypt_enc_get_algorithms_name -- Returns the name of the opened algorithm
mcrypt_enc_get_block_size -- Returns the blocksize of the opened algorithm
mcrypt_enc_get_iv_size -- Returns the size of the IV of the opened algorithm
mcrypt_enc_get_key_size -- Returns the maximum supported keysize of the opened mode
mcrypt_enc_get_modes_name -- Returns the name of the opened mode
mcrypt_enc_get_supported_key_sizes -- Returns an array with the supported keysizes of the opened algorithm
mcrypt_enc_is_block_algorithm_mode -- Checks whether the encryption of the opened mode works on blocks
mcrypt_enc_is_block_algorithm -- Checks whether the algorithm of the opened mode is a block algorithm
mcrypt_enc_is_block_mode -- Checks whether the opened mode outputs blocks
mcrypt_enc_self_test -- This function runs a self test on the opened module
mcrypt_encrypt -- Encrypts plaintext with given parameters
mcrypt_generic_deinit -- This function deinitializes an encryption module
mcrypt_generic_end -- This function terminates encryption
mcrypt_generic_init -- This function initializes all buffers needed for encryption
mcrypt_generic -- This function encrypts data
mcrypt_get_block_size -- Get the block size of the specified cipher
mcrypt_get_cipher_name -- Get the name of the specified cipher
mcrypt_get_iv_size -- Returns the size of the IV belonging to a specific cipher/mode combination
mcrypt_get_key_size -- Get the key size of the specified cipher
mcrypt_list_algorithms -- Get an array of all supported ciphers
mcrypt_list_modes -- Get an array of all supported modes
mcrypt_module_close -- Close the mcrypt module
mcrypt_module_get_algo_block_size -- Returns the blocksize of the specified algorithm
mcrypt_module_get_algo_key_size -- Returns the maximum supported keysize of the opened mode
mcrypt_module_get_supported_key_sizes -- Returns an array with the supported keysizes of the opened algorithm
mcrypt_module_is_block_algorithm_mode -- This function returns if the the specified module is a block algorithm or not
mcrypt_module_is_block_algorithm -- This function checks whether the specified algorithm is a block algorithm
mcrypt_module_is_block_mode -- This function returns if the the specified mode outputs blocks or not
mcrypt_module_open -- This function opens the module of the algorithm and the mode to be used
mcrypt_module_self_test -- This function runs a self test on the specified module
mcrypt_ofb -- Encrypt/decrypt data in OFB mode
mdecrypt_generic -- This function decrypts data

The source can be MCRYPT_RAND (system random number generator), MCRYPT_DEV_RANDOM (read data from /dev/random) and MCRYPT_DEV_URANDOM (read data from /dev/urandom). If you use MCRYPT_RAND, make sure to call srand() before to initialize the random number generator.

Example 1. mcrypt_create_iv() example
<?php $size = mcrypt_get_iv_size (MCRYPT_CAST_256, MCRYPT_MODE_CFB); $iv = mcrypt_create_iv ($size, MCRYPT_DEV_RANDOM); ?>

The IV is only meant to give an alternative seed to the encryption routines. This IV does not need to be secret at all, though it can be desirable. You even can send it along with your ciphertext without loosing security.

More information can be found at http://www.ciphersbyritter.com/GLOSSARY.HTM#IV, http://fn2.freenet.edmonton.ab.ca/~jsavard/crypto/co0409.htm and in chapter 9.3 of Applied Cryptography by Schneier (ISBN 0-471-11709-9) for a discussion of this topic.

mcrypt_decrypt

(PHP 4 >= 4.0.2)

mcrypt_decrypt -- Decrypts crypttext with given parameters

Description

string mcrypt_decrypt ( string cipher, string key, string data, string mode [, string iv])

mcrypt_decrypt() decrypts the data and returns the unencrypted data.

Cipher is one of the MCRYPT_ciphername constants of the name of the algorithm as string.

Key is the key with which the data is encrypted. If it's smaller that the required keysize, it is padded with '\0'.

string mcrypt_enc_get_modes_name ( resource td)

This function returns the name of the mode.

Example 1. mcrypt_enc_get_modes_name() example
<?php $td = mcrypt_module_open (MCRYPT_CAST_256, '', MCRYPT_MODE_CFB, ''); echo mcrypt_enc_get_modes_name($td). "\n"; $td = mcrypt_module_open ('cast-256', '', 'ecb', ''); echo mcrypt_enc_get_modes_name($td). "\n"; ?> Prints: CFB ECB

mcrypt_enc_get_supported_key_sizes

(PHP 4 >= 4.0.2)

mcrypt_enc_get_supported_key_sizes -- Returns an array with the supported keysizes of the opened algorithm

Description

array mcrypt_enc_get_supported_key_sizes ( resource td)

string mcrypt_encrypt ( string cipher, string key, string data, string mode [, string iv])

mcrypt_encrypt() encrypts the data and returns the encrypted data.

Cipher is one of the MCRYPT_ciphername constants of the name of the algorithm as string.

Key is the key with which the data will be encrypted. If it's smaller that the required keysize, it is padded with '\0'. It is better not to use ASCII strings for keys. It is recommended to use the mhash functions to create a key from a string.

Data is the data that will be encrypted with the given cipher and mode. If the size of the data is not n * blocksize, the data will be padded with '\0'. The returned crypttext can be larger that the size of the data that is given by data.

int mcrypt_generic_init ( resource td, string key, string iv)

The maximum length of the key should be the one obtained by calling mcrypt_enc_get_key_size() and every value smaller than this is legal. The IV should normally have the size of the algorithms block size, but you must obtain the size by calling mcrypt_enc_get_iv_size(). IV is ignored in ECB. IV MUST exist in CFB, CBC, STREAM, nOFB and OFB modes. It needs to be random and unique (but not secret). The same IV must be used for encryption/decryption. If you do not want to use it you should set it to zeros, but this is not recommended. The function returns a negative value on error.

You need to call this function before every call to mcrypt_generic() or mdecrypt_generic().

See for an example mcrypt_module_open() and the entry on mcrypt_generic_deinit().

mcrypt_generic

(PHP 4 >= 4.0.2)

mcrypt_generic -- This function encrypts data

int mcrypt_get_iv_size ( resource td)

int mcrypt_get_iv_size ( string cipher, string mode)

The first prototype is when linked against libmcrypt 2.2.x, the second when linked against libmcrypt 2.4.x or higher.

mcrypt_get_iv_size() returns the size of the Initialisation Vector (IV) in bytes. On error the function returns FALSE. If the IV is ignored in the specified cipher/mode combination zero is returned.

bool mcrypt_module_close ( resource td)

array mcrypt_module_get_supported_key_sizes ( string algorithm [, string lib_dir])

resource mcrypt_module_open ( string algorithm, string algorithm_directory, string mode, string mode_directory)

This function opens the module of the algorithm and the mode to be used. The name of the algorithm is specified in algorithm, eg. "twofish" or is one of the MCRYPT_ciphername constants. The module is closed by calling mcrypt_module_close(). Normally it returns an encryption descriptor, or FALSE on error.

The algorithm_directory and mode_directory are used to locate the encryption modules. When you supply a directory name, it is used. When you set one of these to the empty string (""), the value set by the mcrypt.algorithms_dir or mcrypt.modes_dir ini-directive is used. When these are not set, the default directories that are used are the ones that were compiled in into libmcrypt (usally /usr/local/lib/libmcrypt).

string mdecrypt_generic ( resource td, string data)

This function decrypts data. Note that the length of the returned string can in fact be longer then the unencrypted string, due to the padding of the data.

Example 1. mdecrypt_generic() Example
<?php /* Data */ $key = 'this is a very long key, even too long for the cipher'; $plain_text = 'very important data'; /* Open module, and create IV */ $td = mcrypt_module_open ('des', '', 'ecb', ''); $key = substr ($key, 0, mcrypt_enc_get_key_size ($td)); $iv_size = mcrypt_enc_get_iv_size ($td); $iv = mcrypt_create_iv ($iv_size, MCRYPT_RAND); /* Initialize encryption handle */ if (mcrypt_generic_init ($td, $key, $iv) != -1) { /* Encrypt data */ $c_t = mcrypt_generic ($td, $plain_text); mcrypt_generic_deinit ($td); /* Reinitialize buffers for decryption */ mcrypt_generic_init ($td, $key, $iv); $p_t = mdecrypt_generic ($td, $c_t); /* Clean up */ mcrypt_generic_deinit ($td); mcrypt_module_close ($td); } if (strncmp ($p_t, $plain_text, strlen($plain_text)) == 0) { echo "ok\n"; } else { echo "error\n"; } ?>

The above example shows how to check if the data before the encryption is the same as the data after the decryption. It is very important to reinitialize the encryption buffer with mcrypt_generic_init() before you try to decrypt the data.

The decryption handle should alwayws be initialized with mcrypt_generic_init() with a key and an IV before calling this function. Where the encryption is done, you should free the encryption buffers by calling mcrypt_generic_deinit(). See mcrypt_module_open() for an example.

LV. MCVE Payment Functions

Introduction

These functions interface the MCVE API (libmcve), allowing you to work directly with MCVE from your PHP scripts. MCVE is Main Street Softworks' solution to direct credit card processing. It lets you directly address the credit card clearing houses via your *nix box, modem and/or internet connection (bypassing the need for an additional service such as Authorize.Net or Pay Flow Pro). Using the MCVE module for PHP, you can process credit cards directly through MCVE via your PHP scripts. The following references will outline the process.

Note: MCVE is the replacement for RedHat's CCVS. They contracted with RedHat in late 2001 to migrate all existing clientelle to the MCVE platform.

int mcve_void ( resource conn, string username, string password, int sid, int ptrannum)

Warning

This function is currently not documented; only the argument list is available.

LVI. Mhash Functions

Introduction

These functions are intended to work with mhash. Mhash can be used to create checksums, message digests, message authentication codes, and more.

This is an interface to the mhash library. mhash supports a wide variety of hash algorithms such as MD5, SHA1, GOST, and many others. For a complete list of supported hashes, refer to the documentation of mhash. The general rule is that you can access the hash algorithm from PHP with MHASH_HASHNAME. For example, to access TIGER you use the PHP constant MHASH_TIGER.

Requirements

To use it, download the mhash distribution from its web site and follow the included installation instructions.

Installation

You need to compile PHP with the --with-mhash[=DIR] parameter to enable this extension. DIR is the mhash install directory.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

Here is a list of hashes which are currently supported by mhash. If a hash is not listed here, but is listed by mhash as supported, you can safely assume that this documentation is outdated.

MHASH_MD5
MHASH_SHA1
MHASH_HAVAL256
MHASH_HAVAL192
MHASH_HAVAL160
MHASH_HAVAL128
MHASH_RIPEMD160
MHASH_GOST
MHASH_TIGER
MHASH_CRC32
MHASH_CRC32B

Examples

Example 1. Compute the MD5 digest and hmac and print it out as hex
<?php $input = "what do ya want for nothing?"; $hash = mhash (MHASH_MD5, $input); print "The hash is ".bin2hex ($hash)."<br />\n"; $hash = mhash (MHASH_MD5, $input, "Jefe"); print "The hmac is ".bin2hex ($hash)."<br />\n"; ?>
This will produce:
The hash is d03cb659cbf9192dcd066272249f8412 The hmac is 750c783e6ab0b503eaa86e310a5db738

Table of Contents
mhash_count -- Get the highest available hash id
mhash_get_block_size -- Get the block size of the specified hash
mhash_get_hash_name -- Get the name of the specified hash
mhash_keygen_s2k -- Generates a key
mhash -- Compute hash

Example 1. mhash_get_hash_name() example
<?php $hash = MHASH_MD5; print mhash_get_hash_name ($hash); ?>
The above example will print out:
MD5

mhash_keygen_s2k

(PHP 4 >= 4.0.4)

mhash_keygen_s2k -- Generates a key

Description

string mhash_keygen_s2k ( int hash, string password, string salt, int bytes)

mhash_keygen_s2k() generates a key that is bytes long, from a user given password. This is the Salted S2K algorithm as specified in the OpenPGP document (RFC 2440). That algorithm will use the specified hash algorithm to create the key. The salt must be different and random enough for every key you generate in order to create different keys. That salt must be known when you check the keys, thus it is a good idea to append the key to it. Salt has a fixed length of 8 bytes and will be padded with zeros if you supply less bytes.

Keep in mind that user supplied passwords are not really suitable to be used as keys in cryptographic algorithms, since users normally choose keys they can write on keyboard. These passwords use only 6 to 7 bits per character (or less). It is highly recommended to use some kind of tranformation (like this function) to the user supplied key.

mhash

(PHP 3>= 3.0.9, PHP 4 )

mhash -- Compute hash

Description

string mhash ( int hash, string data [, string key])

mhash() applies a hash function specified by hash to the data and returns the resulting hash (also called digest). If the key is specified it will return the resulting HMAC. HMAC is keyed hashing for message authentication, or simply a message digest that depends on the specified key. Not all algorithms supported in mhash can be used in HMAC mode. In case of an error returns FALSE.

LVII. Mimetype Functions

Introduction

The functions in this module try to guess the content type and encoding of a file by looking for certain magic byte sequences at specific positions within the file. While this is not a bullet proof approach the heuristics used do a very good job.

This extension is derivated from Apache mod_mime_magic, which is itself based on the file command maintaind by Ian F. Darwin. See the source code for further historic and copyright information.

Requirements

No external libraries are needed to build this extension.

Installation

The extension needs a copy of the magic.mime as distributed with the file command. This file also part of most recent Linux distributions and usually stored in the /usr/share/misc directory.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Mimetype configuration options

Name	Default	Changeable
mime_magic.magicfile	"/usr/share/misc/magic.mime"	PHP_INI_SYSTEM

For further details and definition of the PHP_INI_* constants see ini_set().

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Table of Contents
mime_content_type -- Detect MIME Content-type for a file

mime_content_type

(PHP 4 CVS only)

mime_content_type -- Detect MIME Content-type for a file

Description

string mime_content_type ( string filename)

Returns the MIME content type for a file as determined by using information from the magic.mime file. Content types are returned in MIME format, like text/plain or application/octet-stream.

LVIII. Microsoft SQL Server functions

Introduction

These functions allow you to access MS SQL Server database.

Note: The MSSQL extension is available on Win32 systems only. You can use the Sybase extension to connect to MSSQL databases from other platforms.

Requirements

The extension requires the MS SQL Client Tools to be installed on the system where PHP is installed. The Client Tools can be installed from the MS SQL Server CD or by copying ntwdblib.dll from \winnt\system32 on the server to \winnt\system32 on the PHP box. Copying ntwdblib.dll will only provide access. Configuration of the client will require installation of all the tools.

Installation

The MSSQL extension is enabled by adding extension=php_mssql.dll to php.ini.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. MS SQL Server configuration options

Name	Default	Changeable
mssql.allow_persistent	"1"	PHP_INI_SYSTEM
mssql.max_persistent	"-1"	PHP_INI_SYSTEM
mssql.max_links	"-1"	PHP_INI_SYSTEM
mssql.min_error_severity	"10"	PHP_INI_ALL
mssql.min_message_severity	"10"	PHP_INI_ALL
mssql.compatability_mode	"0"	PHP_INI_ALL
mssql.connect_timeout	"5"	PHP_INI_ALL
mssql.timeout	"60"	PHP_INI_ALL
mssql.textsize	"-1"	PHP_INI_ALL
mssql.textlimit	"-1"	PHP_INI_ALL
mssql.batchsize	"0"	PHP_INI_ALL
mssql.datetimeconvert	"1"	PHP_INI_ALL
mssql.secure_connection	"0"	PHP_INI_SYSTEM
mssql.max_procs	"25"	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Resource Types

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

MSSQL_ASSOC (integer)
MSSQL_NUM (integer)
MSSQL_BOTH (integer)
SQLTEXT (integer)
SQLVARCHAR (integer)
SQLCHAR (integer)
SQLINT1 (integer)
SQLINT2 (integer)
SQLINT4 (integer)
SQLBIT (integer)
SQLFLT8 (integer)

Table of Contents
mssql_bind -- Adds a parameter to a stored procedure or a remote stored procedure
mssql_close -- Close MS SQL Server connection
mssql_connect -- Open MS SQL server connection
mssql_data_seek -- Move internal row pointer
mssql_execute -- Executes a stored procedure on a MS SQL server database
mssql_fetch_array -- Fetch row as array
mssql_fetch_assoc -- Returns an associative array of the current row in the result set specified by result_id
mssql_fetch_batch -- Returns the next batch of records
mssql_fetch_field -- Get field information
mssql_fetch_object -- Fetch row as object
mssql_fetch_row -- Get row as enumerated array
mssql_field_length -- Get the length of a field
mssql_field_name -- Get the name of a field
mssql_field_seek -- Set field offset
mssql_field_type -- Get the type of a field
mssql_free_result -- Free result memory
mssql_get_last_message -- Returns the last message from server (over min_message_severity?)
mssql_guid_string -- Converts a 16 byte binary GUID to a string
mssql_init -- Initializes a stored procedure or a remote stored procedure
mssql_min_error_severity -- Sets the lower error severity
mssql_min_message_severity -- Sets the lower message severity
mssql_next_result -- Move the internal result pointer to the next result
mssql_num_fields -- Get number of fields in result
mssql_num_rows -- Get number of rows in result
mssql_pconnect -- Open persistent MS SQL connection
mssql_query -- Send MS SQL query
mssql_result -- Get result data
mssql_rows_affected -- Returns the number of records affected by the query
mssql_select_db -- Select MS SQL database

mssql_bind

(PHP 4 >= 4.1.0)

array mssql_fetch_array ( int result)

Returns: An array that corresponds to the fetched row, or FALSE if there are no more rows.

object mssql_fetch_field ( int result [, int field_offset])

Returns an object containing field information.

mssql_fetch_field() can be used in order to obtain information about fields in a certain query result. If the field offset isn't specified, the next field that wasn't yet retrieved by mssql_fetch_field() is retrieved.

The properties of the object are:

name - column name. if the column is a result of a function, this property is set to computed#N, where #N is a serial number.
column_source - the table from which the column was taken
max_length - maximum length of the column
numeric - 1 if the column is numeric

mssql_fetch_object

(PHP 3)

mssql_fetch_object -- Fetch row as object

Description

int mssql_fetch_object ( int result)

Returns: An object with properties that correspond to the fetched row, or FALSE if there are no more rows.

mssql_fetch_object() is similar to mssql_fetch_array(), with one difference - an object is returned, instead of an array. Indirectly, that means that you can only access the data by the field names, and not by their offsets (numbers are illegal property names).

Speed-wise, the function is identical to mssql_fetch_array(), and almost as quick as mssql_fetch_row() (the difference is insignificant).

mssql_fetch_row

(PHP 3, PHP 4 )

mssql_fetch_row -- Get row as enumerated array

Description

array mssql_fetch_row ( int result)

Returns: An array that corresponds to the fetched row, or FALSE if there are no more rows.

mssql_fetch_row() fetches one row of data from the result associated with the specified result identifier. The row is returned as an array. Each result column is stored in an array offset, starting at offset 0.

Subsequent call to mssql_fetch_rows() would return the next row in the result set, or FALSE if there are no more rows.

See also: mssql_fetch_array(), mssql_fetch_object(), mssql_data_seek(), mssql_fetch_lengths(), and mssql_result().

mssql_field_length

(PHP 3>= 3.0.3, PHP 4 )

mssql_field_length -- Get the length of a field

Description

mssql_free_result() only needs to be called if you are worried about using too much memory while your script is running. All result memory will automatically be freed when the script ends. You may call mssql_free_result() with the result identifier as an argument and the associated result memory will be freed.

mssql_get_last_message

(PHP 3, PHP 4 )

bool mssql_next_result ( int result_id)

When sending more than one SQL statement to the server or executing a stored procedure with multiple results, it will cause the server to return multiple result sets. This function will test for additional results available form the server. If an additional result set exists it will free the existing result set and prepare to fetch the rows from the new result set. The function will return TRUE if an additional result set was available or FALSE otherwise.

Example 1. mssql_next_result() example

<?php
    $link = mssql_connect ("localhost", "userid", "secret");
    mssql_select_db("MyDB", $link);
    $SQL = "Select * from table1 select * from table2";
    $rs = mssql_query($SQL, $link);
    do {
        while ($row = mssql_fetch_row($rs)) {
        }
    } while (mssql_next_result($rs));
    mssql_free_result($rs);
    mssql_close ($link);
?>

This function is currently not documented; only the argument list is available.

mssql_select_db

(PHP 3, PHP 4 )

mssql_select_db -- Select MS SQL database

Description

int mssql_select_db ( string database_name [, int link_identifier])

Returns: TRUE on success, FALSE on error

mssql_select_db() sets the current active database on the server that's associated with the specified link identifier. If no link identifier is specified, the last opened link is assumed. If no link is open, the function will try to establish a link as if mssql_connect() was called, and use it.

Every subsequent call to mssql_query() will be made on the active database.

LIX. Ming functions for Flash

Warning

Introduction

First of all: Ming is not an acronym. Ming is an open-source (LGPL) library which allows you to create SWF ("Flash") format movies. Ming supports almost all of Flash 4's features, including: shapes, gradients, bitmaps (pngs and jpegs), morphs ("shape tweens"), text, buttons, actions, sprites ("movie clips"), streaming mp3, and color transforms --the only thing that's missing is sound events.

Note that all values specifying length, distance, size, etc. are in "twips", twenty units per pixel. That's pretty much arbitrary, though, since the player scales the movie to whatever pixel size is specified in the embed/object tag, or the entire frame if not embedded.

Ming offers a number of advantages over the existing PHP/libswf module. You can use Ming anywhere you can compile the code, whereas libswf is closed-source and only available for a few platforms, Windows not one of them. Ming provides some insulation from the mundane details of the SWF file format, wrapping the movie elements in PHP objects. Also, Ming is still being maintained; if there's a feature that you want to see, just let us know ming@opaque.net.

Ming was added in PHP 4.0.5.

Requirements

To use Ming with PHP, you first need to build and install the Ming library. Source code and installation instructions are available at the Ming home page: http://ming.sourceforge.net/ along with examples, a small tutorial, and the latest news.

Download the ming archive. Unpack the archive. Go in the Ming directory. make. make install.

This will build libming.so and install it into /usr/lib/, and copy ming.h into /usr/include/. Edit the PREFIX= line in the Makefile to change the installation directory.

Installation

Example 1. built into php (unix)

       mkdir <phpdir>/ext/ming
       cp php_ext/* <phpdir>/ext/ming
       cd <phpdir>
       ./buildconf
       ./configure --with-ming <other config options>


Build and install php as usual, restart web server if necessary.

Now either just add extension=php_ming.so to your php.ini file, or put dl('php_ming.so'); at the head of all of your Ming scripts.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

SWFBUTTON_HIT (integer)
SWFBUTTON_DOWN (integer)
SWFBUTTON_OVER (integer)
SWFBUTTON_UP (integer)
SWFBUTTON_MOUSEUPOUTSIDE (integer)
SWFBUTTON_DRAGOVER (integer)
SWFBUTTON_DRAGOUT (integer)
SWFBUTTON_MOUSEUP (integer)
SWFBUTTON_MOUSEDOWN (integer)
SWFBUTTON_MOUSEOUT (integer)
SWFBUTTON_MOUSEOVER (integer)
SWFFILL_RADIAL_GRADIENT (integer)
SWFFILL_LINEAR_GRADIENT (integer)
SWFFILL_TILED_BITMAP (integer)
SWFFILL_CLIPPED_BITMAP (integer)
SWFTEXTFIELD_HASLENGTH (integer)
SWFTEXTFIELD_NOEDIT (integer)
SWFTEXTFIELD_PASSWORD (integer)
SWFTEXTFIELD_MULTILINE (integer)
SWFTEXTFIELD_WORDWRAP (integer)
SWFTEXTFIELD_DRAWBOX (integer)
SWFTEXTFIELD_NOSELECT (integer)
SWFTEXTFIELD_HTML (integer)
SWFTEXTFIELD_ALIGN_LEFT (integer)
SWFTEXTFIELD_ALIGN_RIGHT (integer)
SWFTEXTFIELD_ALIGN_CENTER (integer)
SWFTEXTFIELD_ALIGN_JUSTIFY (integer)
SWFACTION_ONLOAD (integer)
SWFACTION_ENTERFRAME (integer)
SWFACTION_UNLOAD (integer)
SWFACTION_MOUSEMOVE (integer)
SWFACTION_MOUSEDOWN (integer)
SWFACTION_MOUSEUP (integer)
SWFACTION_KEYDOWN (integer)
SWFACTION_KEYUP (integer)
SWFACTION_DATA (integer)

Predefined Classes

The classes below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

Ming introduces 13 new objects in PHP, all with matching methods and attributes. To use them, you need to know about objects.

swfshape
swffill
swfgradient
swfbitmap
swftext
swftextfield
swffont
swfdisplayitem
swfmovie
swfbutton
swfaction
swfmorph
swfsprite

Table of Contents
ming_setcubicthreshold -- Set cubic threshold (?)
ming_setscale -- Set scale (?)
ming_useswfversion -- Use SWF version (?)
SWFAction -- Creates a new Action.
SWFBitmap->getHeight -- Returns the bitmap's height.
SWFBitmap->getWidth -- Returns the bitmap's width.
SWFBitmap -- Loads Bitmap object
swfbutton_keypress -- Returns the action flag for keyPress(char)
SWFbutton->addAction -- Adds an action
SWFbutton->addShape -- Adds a shape to a button
SWFbutton->setAction -- Sets the action
SWFbutton->setdown -- Alias for addShape(shape, SWFBUTTON_DOWN))
SWFbutton->setHit -- Alias for addShape(shape, SWFBUTTON_HIT)
SWFbutton->setOver -- Alias for addShape(shape, SWFBUTTON_OVER)
SWFbutton->setUp -- Alias for addShape(shape, SWFBUTTON_UP)
SWFbutton -- Creates a new Button.
SWFDisplayItem->addColor -- Adds the given color to this item's color transform.
SWFDisplayItem->move -- Moves object in relative coordinates.
SWFDisplayItem->moveTo -- Moves object in global coordinates.
SWFDisplayItem->multColor -- Multiplies the item's color transform.
SWFDisplayItem->remove -- Removes the object from the movie
SWFDisplayItem->Rotate -- Rotates in relative coordinates.
SWFDisplayItem->rotateTo -- Rotates the object in global coordinates.
SWFDisplayItem->scale -- Scales the object in relative coordinates.
SWFDisplayItem->scaleTo -- Scales the object in global coordinates.
SWFDisplayItem->setDepth -- Sets z-order
SWFDisplayItem->setName -- Sets the object's name
SWFDisplayItem->setRatio -- Sets the object's ratio.
SWFDisplayItem->skewX -- Sets the X-skew.
SWFDisplayItem->skewXTo -- Sets the X-skew.
SWFDisplayItem->skewY -- Sets the Y-skew.
SWFDisplayItem->skewYTo -- Sets the Y-skew.
SWFDisplayItem -- Creates a new displayitem object.
SWFFill->moveTo -- Moves fill origin
SWFFill->rotateTo -- Sets fill's rotation
SWFFill->scaleTo -- Sets fill's scale
SWFFill->skewXTo -- Sets fill x-skew
SWFFill->skewYTo -- Sets fill y-skew
SWFFill -- Loads SWFFill object
swffont->getwidth -- Returns the string's width
SWFFont -- Loads a font definition
SWFGradient->addEntry -- Adds an entry to the gradient list.
SWFGradient -- Creates a gradient object
SWFMorph->getshape1 -- Gets a handle to the starting shape
SWFMorph->getshape2 -- Gets a handle to the ending shape
SWFMorph -- Creates a new SWFMorph object.
SWFMovie->add -- Adds any type of data to a movie.
SWFMovie->nextframe -- Moves to the next frame of the animation.
SWFMovie->output -- Dumps your lovingly prepared movie out.
SWFMovie->remove -- Removes the object instance from the display list.
SWFMovie->save -- Saves your movie in a file.
SWFMovie->setbackground -- Sets the background color.
SWFMovie->setdimension -- Sets the movie's width and height.
SWFMovie->setframes -- Sets the total number of frames in the animation.
SWFMovie->setrate -- Sets the animation's frame rate.
SWFMovie->streammp3 -- Streams a MP3 file.
SWFMovie -- Creates a new movie object, representing an SWF version 4 movie.
SWFShape->addFill -- Adds a solid fill to the shape.
SWFShape->drawCurve -- Draws a curve (relative).
SWFShape->drawCurveTo -- Draws a curve.
SWFShape->drawLine -- Draws a line (relative).
SWFShape->drawLineTo -- Draws a line.
SWFShape->movePen -- Moves the shape's pen (relative).
SWFShape->movePenTo -- Moves the shape's pen.
SWFShape->setLeftFill -- Sets left rasterizing color.
SWFShape->setLine -- Sets the shape's line style.
SWFShape->setRightFill -- Sets right rasterizing color.
SWFShape -- Creates a new shape object.
SWFSprite->add -- Adds an object to a sprite
SWFSprite->nextframe -- Moves to the next frame of the animation.
SWFSprite->remove -- Removes an object to a sprite
SWFSprite->setframes -- Sets the total number of frames in the animation.
SWFSprite -- Creates a movie clip (a sprite)
SWFText->addString -- Draws a string
SWFText->getWidth -- Computes string's width
SWFText->moveTo -- Moves the pen
SWFText->setColor -- Sets the current font color
SWFText->setFont -- Sets the current font
SWFText->setHeight -- Sets the current font height
SWFText->setSpacing -- Sets the current font spacing
SWFText -- Creates a new SWFText object.
SWFTextField->addstring -- Concatenates the given string to the text field
SWFTextField->align -- Sets the text field alignment
SWFTextField->setbounds -- Sets the text field width and height
SWFTextField->setcolor -- Sets the color of the text field.
SWFTextField->setFont -- Sets the text field font
SWFTextField->setHeight -- Sets the font height of this text field font.
SWFTextField->setindentation -- Sets the indentation of the first line.
SWFTextField->setLeftMargin -- Sets the left margin width of the text field.
SWFTextField->setLineSpacing -- Sets the line spacing of the text field.
SWFTextField->setMargins -- Sets the margins width of the text field.
SWFTextField->setname -- Sets the variable name
SWFTextField->setrightMargin -- Sets the right margin width of the text field.
SWFTextField -- Creates a text field object

The script syntax is based on the C language, but with a lot taken out- the SWF bytecode machine is just too simpleminded to do a lot of things we might like. For instance, we can't implement function calls without a tremendous amount of hackery because the jump bytecode has a hardcoded offset value. No pushing your calling address to the stack and returning- every function would have to know exactly where to return to.

So what's left? The compiler recognises the following tokens:

break
for
continue
if
else
do
while

There is no typed data; all values in the SWF action machine are stored as strings. The following functions can be used in expressions:

time(): Returns the number of milliseconds (?) elapsed since the movie started.
random(seed): Returns a pseudo-random number in the range 0-seed.
length(expr): Returns the length of the given expression.
int(number): Returns the given number rounded down to the nearest integer.
concat(expr, expr): Returns the concatenation of the given expressions.
ord(expr): Returns the ASCII code for the given character
chr(num): Returns the character for the given ASCII code
substr(string, location, length): Returns the substring of length length at location location of the given string string.

Additionally, the following commands may be used:

duplicateClip(clip, name, depth): Duplicate the named movie clip (aka sprite). The new movie clip has name name and is at depth depth.
removeClip(expr): Removes the named movie clip.
trace(expr): Write the given expression to the trace log. Doubtful that the browser plugin does anything with this.
startDrag(target, lock, [left, top, right, bottom]): Start dragging the movie clip target. The lock argument indicates whether to lock the mouse (?)- use 0 (FALSE) or 1 (TRUE). Optional parameters define a bounding area for the dragging.
stopDrag(): Stop dragging my heart around. And this movie clip, too.
callFrame(expr): Call the named frame as a function.
getURL(url, target, [method]): Load the given URL into the named target. The target argument corresponds to HTML document targets (such as "_top" or "_blank"). The optional method argument can be POST or GET if you want to submit variables back to the server.
loadMovie(url, target): Load the given URL into the named target. The target argument can be a frame name (I think), or one of the magical values "_level0" (replaces current movie) or "_level1" (loads new movie on top of current movie).
nextFrame(): Go to the next frame.
prevFrame(): Go to the last (or, rather, previous) frame.
play(): Start playing the movie.
stop(): Stop playing the movie.
toggleQuality(): Toggle between high and low quality.
stopSounds(): Stop playing all sounds.
gotoFrame(num): Go to frame number num. Frame numbers start at 0.
gotoFrame(name): Go to the frame named name. Which does a lot of good, since I haven't added frame labels yet.
setTarget(expr): Sets the context for action. Or so they say- I really have no idea what this does.

And there's one weird extra thing. The expression frameLoaded(num) can be used in if statements and while loops to check if the given frame number has been loaded yet. Well, it's supposed to, anyway, but I've never tested it and I seriously doubt it actually works. You can just use /:framesLoaded instead.

Movie clips (all together now- aka sprites) have properties. You can read all of them (or can you?), you can set some of them, and here they are:

x
y
xScale
yScale
currentFrame - (read-only)
totalFrames - (read-only)
alpha - transparency level
visible - 1=on, 0=off (?)
width - (read-only)
height - (read-only)
rotation
target - (read-only) (???)
framesLoaded - (read-only)
name
dropTarget - (read-only) (???)
url - (read-only) (???)
highQuality - 1=high, 0=low (?)
focusRect - (???)
soundBufTime - (???)

So, setting a sprite's x position is as simple as /box.x = 100;. Why the slash in front of the box, though? That's how flash keeps track of the sprites in the movie, just like a unix filesystem- here it shows that box is at the top level. If the sprite named box had another sprite named biff inside of it, you'd set its x position with /box/biff.x = 100;. At least, I think so; correct me if I'm wrong here.

This simple example will move the red square across the window.
Example 1. swfaction() example
<?php $s = new SWFShape(); $f = $s->addFill(0xff, 0, 0); $s->setRightFill($f); $s->movePenTo(-500,-500); $s->drawLineTo(500,-500); $s->drawLineTo(500,500); $s->drawLineTo(-500,500); $s->drawLineTo(-500,-500); $p = new SWFSprite(); $i = $p->add($s); $i->setDepth(1); $p->nextFrame(); for($n=0; $n<5; ++$n) { $i->rotate(-15); $p->nextFrame(); } $m = new SWFMovie(); $m->setBackground(0xff, 0xff, 0xff); $m->setDimension(6000,4000); $i = $m->add($p); $i->setDepth(1); $i->moveTo(-500,2000); $i->setName("box"); $m->add(new SWFAction("/box.x += 3;")); $m->nextFrame(); $m->add(new SWFAction("gotoFrame(0); play();")); $m->nextFrame(); header('Content-type: application/x-shockwave-flash'); $m->output(); ?>

new swfbitmap ( string filename [, int alphafilename])

Warning

swfbitmap() creates a new SWFBitmap object from the Jpeg or DBL file named filename. alphafilename indicates a MSK file to be used as an alpha mask for a Jpeg image.

Note: We can only deal with baseline (frame 0) jpegs, no baseline optimized or progressive scan jpegs!

SWFBitmap has the following methods : swfbitmap->getwidth() and swfbitmap->getheight().

You can't import png images directly, though- have to use the png2dbl utility to make a dbl ("define bits lossless") file from the png. The reason for this is that I don't want a dependency on the png library in ming- autoconf should solve this, but that's not set up yet.
Example 1. Import PNG files
<?php $s = new SWFShape(); $f = $s->addFill(new SWFBitmap("png.dbl")); $s->setRightFill($f); $s->drawLine(32, 0); $s->drawLine(0, 32); $s->drawLine(-32, 0); $s->drawLine(0, -32); $m = new SWFMovie(); $m->setDimension(32, 32); $m->add($s); header('Content-type: application/x-shockwave-flash'); $m->output(); ?>

And you can put an alpha mask on a jpeg fill.
Example 2. swfbitmap() example
<?php $s = new SWFShape(); // .msk file generated with "gif2mask" utility $f = $s->addFill(new SWFBitmap("alphafill.jpg", "alphafill.msk")); $s->setRightFill($f); $s->drawLine(640, 0); $s->drawLine(0, 480); $s->drawLine(-640, 0); $s->drawLine(0, -480); $c = new SWFShape(); $c->setRightFill($c->addFill(0x99, 0x99, 0x99)); $c->drawLine(40, 0); $c->drawLine(0, 40); $c->drawLine(-40, 0); $c->drawLine(0, -40); $m = new SWFMovie(); $m->setDimension(640, 480); $m->setBackground(0xcc, 0xcc, 0xcc); // draw checkerboard background for($y=0; $y<480; $y+=40) { for($x=0; $x<640; $x+=80) { $i = $m->add($c); $i->moveTo($x, $y); } $y+=40; for($x=40; $x<640; $x+=80) { $i = $m->add($c); $i->moveTo($x, $y); } } $m->add($s); header('Content-type: application/x-shockwave-flash'); $m->output(); ?>

swfbutton_keypress

(PHP 4 >= 4.0.5)

swfbutton_keypress -- Returns the action flag for keyPress(char)

Description

int swfbutton_keypress ( string str)

Warning

This function is currently not documented; only the argument list is available.

SWFbutton->addAction

(no version information, might be only in CVS)

SWFbutton->addAction -- Adds an action

Description

void swfbutton->addaction ( ressource action, int flags)

Warning

swfbutton->addaction() adds the action action to this button for the given conditions. The following flags are valid: SWFBUTTON_MOUSEOVER, SWFBUTTON_MOUSEOUT, SWFBUTTON_MOUSEUP, SWFBUTTON_MOUSEUPOUTSIDE, SWFBUTTON_MOUSEDOWN, SWFBUTTON_DRAGOUT and SWFBUTTON_DRAGOVER.

See also swfbutton->addshape() and SWFAction().

SWFbutton->addShape

(no version information, might be only in CVS)

SWFbutton->addShape -- Adds a shape to a button

new swfbutton ( void)

Warning

void swfdisplayitem->multcolor ( [int red [, int green [, int blue [, int a]]]])

Warning

swfdisplayitem->multcolor() multiplies the item's color transform by the given values.

The object may be a swfshape(), a swfbutton(), a swftext() or a swfsprite() object. It must have been added using the swfmovie->add().

This simple example will modify your picture's atmospher to Halloween (use a landscape or bright picture).
Example 1. swfdisplayitem->multcolor() example
<?php $b = new SWFBitmap("backyard.jpg"); // note use your own picture :-) $s = new SWFShape(); $s->setRightFill($s->addFill($b)); $s->drawLine($b->getWidth(), 0); $s->drawLine(0, $b->getHeight()); $s->drawLine(-$b->getWidth(), 0); $s->drawLine(0, -$b->getHeight()); $m = new SWFMovie(); $m->setDimension($b->getWidth(), $b->getHeight()); $i = $m->add($s); for($n=0; $n<=20; ++$n) { $i->multColor(1.0-$n/10, 1.0, 1.0); $i->addColor(0xff*$n/20, 0, 0); $m->nextFrame(); } header('Content-type: application/x-shockwave-flash'); $m->output(); ?>

SWFDisplayItem->remove

(no version information, might be only in CVS)

SWFDisplayItem->remove -- Removes the object from the movie

void swffill->skewyto ( float y)

Warning

swffill->skewyto() sets fill y-skew to y. For y is 1.0, it is a is a 45-degree upward slant. More is more upward, less is more downward.

SWFFill

SWFFill -- Loads SWFFill object

Description

The swffill() object allows you to transform (scale, skew, rotate) bitmap and gradient fills. swffill() objects are created by the swfshape->addfill() methods.

SWFFill has the following methods : swffill->moveto() and swffill->scaleto(), swffill->rotateto(), swffill->skewxto() and swffill->skewyto().

swffont->getwidth

(no version information, might be only in CVS)

swffont->getwidth -- Returns the string's width

Description

int swffont->getwidth ( string string)

Warning

swffont->getwidth() returns the string string's width, using font's default scaling. You'll probably want to use the SWFText() version of this method which uses the text object's scale.

SWFFont

(PHP 4 >= 4.0.5)

SWFFont -- Loads a font definition

Description

new swffont ( string filename)

Warning

If filename is the name of an FDB file (i.e., it ends in ".fdb"), load the font definition found in said file. Otherwise, create a browser-defined font reference.

FDB ("font definition block") is a very simple wrapper for the SWF DefineFont2 block which contains a full description of a font. One may create FDB files from SWT Generator template files with the included makefdb utility- look in the util directory off the main ming distribution directory.

Browser-defined fonts don't contain any information about the font other than its name. It is assumed that the font definition will be provided by the movie player. The fonts _serif, _sans, and _typewriter should always be available. For example:
<?php $f = newSWFFont("_sans"); ?>
will give you the standard sans-serif font, probably the same as what you'd get with <font name="sans-serif"> in HTML.

swffont() returns a reference to the font definition, for use in the SWFText->setFont() and the SWFTextField->setFont() methods.

SWFFont has the following methods : swffont->getwidth().

SWFGradient->addEntry

(no version information, might be only in CVS)

SWFGradient->addEntry -- Adds an entry to the gradient list.

Description

void swfgradient->addentry ( float ratio, int red, int green, int blue [, int a])

Warning

swfgradient->addentry() adds an entry to the gradient list. ratio is a number between 0 and 1 indicating where in the gradient this color appears. Thou shalt add entries in order of increasing ratio.

red, green, blue is a color (RGB mode). Last parameter a is optional.

SWFGradient

(PHP 4 >= 4.0.5)

SWFGradient -- Creates a gradient object

Description

new swfgradient ( void)

Warning

swfgradient() creates a new SWFGradient object.

new swfmorph ( void)

Warning

swfmorph() creates a new SWFMorph object.

Also called a "shape tween". This thing lets you make those tacky twisting things that make your computer choke. Oh, joy!

The methods here are sort of weird. It would make more sense to just have newSWFMorph(shape1, shape2);, but as things are now, shape2 needs to know that it's the second part of a morph. (This, because it starts writing its output as soon as it gets drawing commands- if it kept its own description of its shapes and wrote on completion this and some other things would be much easier.)

SWFMorph has the following methods : swfmorph->getshape1() and swfmorph->getshape1().

This simple example will morph a big red square into a smaller blue black-bordered square.
Example 1. swfmorph() example
<?php $p = new SWFMorph(); $s = $p->getShape1(); $s->setLine(0,0,0,0); /* Note that this is backwards from normal shapes (left instead of right). I have no idea why, but this seems to work.. */ $s->setLeftFill($s->addFill(0xff, 0, 0)); $s->movePenTo(-1000,-1000); $s->drawLine(2000,0); $s->drawLine(0,2000); $s->drawLine(-2000,0); $s->drawLine(0,-2000); $s = $p->getShape2(); $s->setLine(60,0,0,0); $s->setLeftFill($s->addFill(0, 0, 0xff)); $s->movePenTo(0,-1000); $s->drawLine(1000,1000); $s->drawLine(-1000,1000); $s->drawLine(-1000,-1000); $s->drawLine(1000,-1000); $m = new SWFMovie(); $m->setDimension(3000,2000); $m->setBackground(0xff, 0xff, 0xff); $i = $m->add($p); $i->moveTo(1500,1000); for($r=0.0; $r<=1.0; $r+=0.1) { $i->setRatio($r); $m->nextFrame(); } header('Content-type: application/x-shockwave-flash'); $m->output(); ?>

SWFMovie->add

(no version information, might be only in CVS)

SWFMovie->add -- Adds any type of data to a movie.

Description

void swfmovie->add ( ressource instance)

Warning

swfmovie->add() adds instance to the current movie. instance is any type of data : Shapes, text, fonts, etc. must all be add'ed to the movie to make this work.

void swfmovie->streammp3 ( string mp3FileName)

Warning

swfmovie->streammp3() streams the mp3 file mp3FileName. Not very robust in dealing with oddities (can skip over an initial ID3 tag, but that's about it). Like SWFShape->addJpegFill(), this isn't a stable function- we'll probably need to make a separate SWFSound object to contain sound types.

Note that the movie isn't smart enough to put enough frames in to contain the entire mp3 stream- you'll have to add (length of song * frames per second) frames to get the entire stream in.

Yes, now you can use ming to put that rock and roll devil worship music into your SWF files. Just don't tell the RIAA.
Example 1. swfmovie->streammp3() example
<?php $m = new SWFMovie(); $m->setRate(12.0); $m->streamMp3("distortobass.mp3"); // use your own MP3 // 11.85 seconds at 12.0 fps = 142 frames $m->setFrames(142); header('Content-type: application/x-shockwave-flash'); $m->output(); ?>

SWFMovie

(PHP 4 >= 4.0.5)

SWFMovie -- Creates a new movie object, representing an SWF version 4 movie.

Description

new swfmovie ( void)

Warning

swfmovie() creates a new movie object, representing an SWF version 4 movie.

SWFMovie has the following methods : swfmovie->output(),swfmovie->save(), swfmovie->add(), swfmovie->remove(), swfmovie->nextframe(), swfmovie->setbackground(), swfmovie->setrate(), swfmovie->setdimension(), swfmovie->setframes() and swfmovie->streammp3().

See examples in : swfdisplayitem->rotateto(), swfshape->setline(), swfshape->addfill()... Any example will use this object.

SWFShape->addFill

(no version information, might be only in CVS)

SWFShape->addFill -- Adds a solid fill to the shape.

Description

void swfshape->addfill ( int red, int green, int blue [, int a])

Warning

void swfshape->addfill ( SWFbitmap bitmap [, int flags])

Warning

void swfshape->addfill ( SWFGradient gradient [, int flags])

Warning

swfshape->addfill() adds a solid fill to the shape's list of fill styles. swfshape->addfill() accepts three different types of arguments.

red, green, blue is a color (RGB mode). Last parameter a is optional.

The bitmap argument is an swfbitmap() object. The flags argument can be one of the following values : SWFFILL_CLIPPED_BITMAP or SWFFILL_TILED_BITMAP. Default is SWFFILL_TILED_BITMAP. I think.

void swfshape->setleftfill ( swfgradient fill)

Warning

void swfshape->setleftfill ( int red, int green, int blue [, int a])

Warning

What this nonsense is about is, every edge segment borders at most two fills. When rasterizing the object, it's pretty handy to know what those fills are ahead of time, so the swf format requires these to be specified.

swfshape->setleftfill() sets the fill on the left side of the edge- that is, on the interior if you're defining the outline of the shape in a counter-clockwise fashion. The fill object is an SWFFill object returned from one of the addFill functions above.

This seems to be reversed when you're defining a shape in a morph, though. If your browser crashes, just try setting the fill on the other side.

Shortcut for swfshape->setleftfill($s->addfill($r, $g, $b [, $a]));.

SWFShape->setLine

(no version information, might be only in CVS)

SWFShape->setLine -- Sets the shape's line style.

Description

void swfshape->setline ( int width [, int red [, int green [, int blue [, int a]]]])

Warning

swfshape->setline() sets the shape's line style. width is the line's width. If width is 0, the line's style is removed (then, all other arguments are ignored). If width > 0, then line's color is set to red, green, blue. Last parameter a is optional.

swfshape->setline() accepts 1, 4 or 5 arguments (not 3 or 2).

You must declare all line styles before you use them (see example).

This simple example will draw a big "!#%*@", in funny colors and gracious style.
Example 1. swfshape->setline() example
<?php $s = new SWFShape(); $f1 = $s->addFill(0xff, 0, 0); $f2 = $s->addFill(0xff, 0x7f, 0); $f3 = $s->addFill(0xff, 0xff, 0); $f4 = $s->addFill(0, 0xff, 0); $f5 = $s->addFill(0, 0, 0xff); // bug: have to declare all line styles before you use them $s->setLine(40, 0x7f, 0, 0); $s->setLine(40, 0x7f, 0x3f, 0); $s->setLine(40, 0x7f, 0x7f, 0); $s->setLine(40, 0, 0x7f, 0); $s->setLine(40, 0, 0, 0x7f); $f = new SWFFont('Techno.fdb'); $s->setRightFill($f1); $s->setLine(40, 0x7f, 0, 0); $s->drawGlyph($f, '!'); $s->movePen($f->getWidth('!'), 0); $s->setRightFill($f2); $s->setLine(40, 0x7f, 0x3f, 0); $s->drawGlyph($f, '#'); $s->movePen($f->getWidth('#'), 0); $s->setRightFill($f3); $s->setLine(40, 0x7f, 0x7f, 0); $s->drawGlyph($f, '%'); $s->movePen($f->getWidth('%'), 0); $s->setRightFill($f4); $s->setLine(40, 0, 0x7f, 0); $s->drawGlyph($f, '*'); $s->movePen($f->getWidth('*'), 0); $s->setRightFill($f5); $s->setLine(40, 0, 0, 0x7f); $s->drawGlyph($f, '@'); $m = new SWFMovie(); $m->setDimension(3000,2000); $m->setRate(12.0); $i = $m->add($s); $i->moveTo(1500-$f->getWidth("!#%*@")/2, 1000+$f->getAscent()/2); header('Content-type: application/x-shockwave-flash'); $m->output(); ?>

SWFShape->setRightFill

(no version information, might be only in CVS)

SWFShape->setRightFill -- Sets right rasterizing color.

Description

void swfshape->setrightfill ( swfgradient fill)

Warning

new swftext ( void)

Warning

new swftextfield ( [int flags])

Warning

swftextfield() creates a new text field object. Text Fields are less flexible than swftext() objects- they can't be rotated, scaled non-proportionally, or skewed, but they can be used as form entries, and they can use browser-defined fonts.

The optional flags change the text field's behavior. It has the following possibles values :

SWFTEXTFIELD_DRAWBOX draws the outline of the textfield
SWFTEXTFIELD_HASLENGTH
SWFTEXTFIELD_HTML allows text markup using HTML-tags
SWFTEXTFIELD_MULTILINE allows multiple lines
SWFTEXTFIELD_NOEDIT indicates that the field shouldn't be user-editable
SWFTEXTFIELD_NOSELECT makes the field non-selectable
SWFTEXTFIELD_PASSWORD obscures the data entry
SWFTEXTFIELD_WORDWRAP allows text to wrap

Flags are combined with the bitwise OR operation. For example,

<?php
$t = newSWFTextField(SWFTEXTFIELD_PASSWORD | SWFTEXTFIELD_NOEDIT); 
?>

creates a totally useless non-editable password field.

SWFTextField has the following methods : swftextfield->setfont(), swftextfield->setbounds(), swftextfield->align(), swftextfield->setheight(), swftextfield->setleftmargin(), swftextfield->setrightmargin(), swftextfield->setmargins(), swftextfield->setindentation(), swftextfield->setlinespacing(), swftextfield->setcolor(), swftextfield->setname() and swftextfield->addstring().

LX. Miscellaneous functions

Introduction

These functions were placed here because none of the other categories seemed to fit.

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Misc. Configuration Options

Name	Default	Changeable
ignore_user_abort	"0"	PHP_INI_ALL
highlight.string	#CC0000	PHP_INI_ALL
highlight.comment	#FF9900	PHP_INI_ALL
highlight.keyword	#006600	PHP_INI_ALL
highlight.bg	#FFFFFF	PHP_INI_ALL
highlight.default	#0000CC	PHP_INI_ALL
highlight.html	#000000	PHP_INI_ALL
browscap	NULL	PHP_INI_SYSTEM

For further details and definition of the PHP_INI_* constants see ini_set().

Here is a short explanation of the configuration directives.

ignore_user_abort boolean

TRUE by default. If changed to FALSE scripts will be terminated as soon as they try to output something after a client has aborted their connection.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Table of Contents
connection_aborted -- Returns TRUE if client disconnected
connection_status -- Returns connection status bitfield
connection_timeout -- Return TRUE if script timed out
constant -- Returns the value of a constant
define -- Defines a named constant.
defined -- Checks whether a given named constant exists
die -- Alias of exit()
eval -- Evaluate a string as PHP code
exit -- Output a message and terminate the current script
get_browser -- Tells what the user's browser is capable of
highlight_file -- Syntax highlighting of a file
highlight_string -- Syntax highlighting of a string
ignore_user_abort -- Set whether a client disconnect should abort script execution
leak -- Leak memory
pack -- Pack data into binary string.
show_source -- Syntax highlighting of a file
sleep -- Delay execution
uniqid -- Generate a unique ID
unpack -- Unpack data from binary string
usleep -- Delay execution in microseconds

The name of the constant is given by name; the value is given by value.

The optional third parameter case_insensitive is also available. If the value TRUE is given, then the constant will be defined case-insensitive. The default behaviour is case-sensitive; i.e. CONSTANT and Constant represent different values.

Example 1. Defining Constants
<?php define ("CONSTANT", "Hello world."); echo CONSTANT; // outputs "Hello world." echo Constant; // outputs "Constant" and issues a notice. define ("GREETING", "Hello you.",TRUE); echo GREETING; // outputs "Hello you." echo Greeting; // outputs "Hello you." ?>

define() returns TRUE on success and FALSE if an error occurs.

See also defined(), constant() and the section on Constants.

defined

(PHP 3, PHP 4 )

defined -- Checks whether a given named constant exists

Description

bool defined ( string name)

Returns TRUE if the named constant given by name has been defined, FALSE otherwise.
Example 1. Checking Constants
<?php if (defined("CONSTANT")){ // Note that it should be quoted echo CONSTANT; // } ?>

See also define(), constant(), get_defined_constants() and the section on Constants.

die

die -- Alias of exit()

Description

This function is an alias of exit().

eval

(PHP 3, PHP 4 )

eval -- Evaluate a string as PHP code

Description

mixed eval ( string code_str)

eval() evaluates the string given in code_str as PHP code. Among other things, this can be useful for storing code in a database text field for later execution.

There are some factors to keep in mind when using eval(). Remember that the string passed must be valid PHP code, including things like terminating statements with a semicolon so the parser doesn't die on the line after the eval(), and properly escaping things in code_str.

Also remember that variables given values under eval() will retain these values in the main script afterwards.

A return statement will terminate the evaluation of the string immediately. In PHP 4, eval() returns NULL unless return() is called in the evaluated code, in which case the value passed to return() is returned. In PHP 3, eval() does not return a value.

Example 1. eval() example - simple text merge
<?php $string = 'cup'; $name = 'coffee'; $str = 'This is a $string with my $name in it.<br>'; echo $str; eval ("\$str = \"$str\";"); echo $str; ?>
The above example will show:
This is a $string with my $name in it. This is a cup with my coffee in it.

Tip: As with anything that outputs its result directly to the browser, you can use the output-control functions to capture the output of this function, and save it in a string (for example).

exit

(PHP 3, PHP 4 )

exit -- Output a message and terminate the current script

Description

void exit ( [string status])

void exit ( int status)

Note: This is not a real function, but a language construct.

The exit() function terminates execution of the script. It prints status just before exiting.

If status is an integer, that value will also be used as the exit status. Exit statuses should be in the range 1 to 254, the exit status 255 is reserved by PHP and shall not be used.

Note: The current CVS version does NOT print the status if it is an integer.

Note: The die() function is an alias for exit().

Example 1. exit() example
<?php $filename = '/path/to/data-file'; $file = fopen ($filename, 'r') or exit("unable to open file ($filename)"); ?>

get_browser

(PHP 3, PHP 4 )

get_browser -- Tells what the user's browser is capable of

Description

object get_browser ( [string user_agent])

get_browser() attempts to determine the capabilities of the user's browser. This is done by looking up the browser's information in the browscap.ini file. By default, the value of $HTTP_USER_AGENT is used; however, you can alter this (i.e., look up another browser's info) by passing the optional user_agent parameter to get_browser().

The information is returned in an object, which will contain various data elements representing, for instance, the browser's major and minor version numbers and ID string; TRUE/false values for features such as frames, JavaScript, and cookies; and so forth.

While browscap.ini contains information on many browsers, it relies on user updates to keep the database current. The format of the file is fairly self-explanatory.

The following example shows how one might list all available information retrieved about the user's browser.
Example 1. get_browser() example
<?php function list_array ($array) { while (list ($key, $value) = each ($array)) { $str .= "<b>$key:</b> $value<br />\n"; } return $str; } echo "$HTTP_USER_AGENT<hr />\n"; $browser = get_browser(); echo list_array ((array) $browser); ?>

The output of the above script would look something like this:

Mozilla/4.5 [en] (X11; U; Linux 2.2.9 i586)<hr />
<b>browser_name_pattern:</b> Mozilla/4\.5.*<br />
<b>parent:</b> Netscape 4.0<br />
<b>platform:</b> Unknown<br />
<b>majorver:</b> 4<br />
<b>minorver:</b> 5<br />
<b>browser:</b> Netscape<br />
<b>version:</b> 4<br />
<b>frames:</b> 1<br />
<b>tables:</b> 1<br />
<b>cookies:</b> 1<br />
<b>backgroundsounds:</b> <br />
<b>vbscript:</b> <br />
<b>javascript:</b> 1<br />
<b>javaapplets:</b> 1<br />
<b>activexcontrols:</b> <br />
<b>beta:</b> <br />
<b>crawler:</b> <br />
<b>authenticodeupdate:</b> <br />
<b>msn:</b> <br />

In order for this to work, your browscap configuration file setting must point to the correct location of the browscap.ini file.

For more information (including locations from which you may obtain a browscap.ini file), check the PHP FAQ at http://www.php.net/FAQ.php.

highlight_file

(PHP 4 )

highlight_file -- Syntax highlighting of a file

Description

mixed highlight_file ( string filename [, bool return])

The highlight_file() function prints out a syntax higlighted version of the code contained in filename using the colors defined in the built-in syntax highlighter for PHP.

If the second parameter return is set to TRUE then highlight_file() will return the highlighted code as a string instead of printing it out. If the second parameter is not set to TRUE then highlight_file() will return TRUE on success, FALSE on failure.

Note: The return parameter became available in PHP 4.2.0. Before this time it behaved like the default, which is FALSE

Note: Care should be taken when using the show_source() and highlight_file() functions to make sure that you do not inadvertently reveal sensitive information such as passwords or any other type of information that might create a potential security risk.

Note: Since PHP 4.2.1 this function is also affected by safe_mode and open_basedir.

Example 1. Creating a source highlighting URL
To setup a URL that can code hightlight any script that you pass to it, we will make use of the "ForceType" directive in Apache to generate a nice URL pattern, and use the function highlight_file() to show a nice looking code list.
In your httpd.conf you can add the following:

<Location /source> ForceType application/x-httpd-php </Location>

And then make a file named "source" and put it in your web root directory.

<HTML> <HEAD> <TITLE>Source Display</TITLE> </HEAD> <BODY BGCOLOR="white"> <?php $script = getenv ("PATH_TRANSLATED"); if(!$script) { echo "<BR><B>ERROR: Script Name needed</B><BR>"; } else { if (ereg("(\.php|\.inc)$",$script)) { echo "<H1>Source of: $PATH_INFO</H1>\n<HR>\n"; highlight_file($script); } else { echo "<H1>ERROR: Only PHP or include script names are allowed</H1>"; } } echo "<HR>Processed: ".date("Y/M/d H:i:s",time()); ?> </BODY> </HTML>

Then you can use an URL like the one below to display a colorized version of a script located in "/path/to/script.php" in your web site.

http://your.server.com/source/path/to/script.php

highlight_string

(PHP 4 )

highlight_string -- Syntax highlighting of a string

Description

mixed highlight_string ( string str [, bool return])

The highlight_string() function outputs a syntax highlighted version of str using the colors defined in the built-in syntax highlighter for PHP.

If the second parameter return is set to TRUE then highlight_string() will return the highlighted code as a string instead of printing it out. If the second parameter is not set to TRUE then highlight_string() will return TRUE on success, FALSE on failure.

Note: The return parameter became available in PHP 4.2.0. Before this time it behaved like the default, which is FALSE

See also highlight_file(), and show_source().

ignore_user_abort

(PHP 3>= 3.0.7, PHP 4 )

ignore_user_abort -- Set whether a client disconnect should abort script execution

Description

int ignore_user_abort ( [int setting])

This function sets whether a client disconnect should cause a script to be aborted. It will return the previous setting and can be called without an argument to not change the current setting and only return the current setting. See the Connection Handling section in the Features chapter for a complete description of connection handling in PHP.

leak

(PHP 3, PHP 4 )

leak -- Leak memory

Description

void leak ( int bytes)

leak() leaks the specified amount of memory.

This is useful when debugging the memory manager, which automatically cleans up "leaked" memory when each request is completed.

pack

(PHP 3, PHP 4 )

pack -- Pack data into binary string.

Description

string pack ( string format [, mixed args])

Pack given arguments into binary string according to format. Returns binary string containing data.

The idea to this function was taken from Perl and all formatting codes work the same as there, however, there are some formatting codes that are missing such as Perl's "u" format code. The format string consists of format codes followed by an optional repeater argument. The repeater argument can be either an integer value or * for repeating to the end of the input data. For a, A, h, H the repeat count specifies how many characters of one data argument are taken, for @ it is the absolute position where to put the next data, for everything else the repeat count specifies how many data arguments are consumed and packed into the resulting binary string. Currently implemented are

a NUL-padded string
A SPACE-padded string
h Hex string, low nibble first
H Hex string, high nibble first
c signed char
C unsigned char
s signed short (always 16 bit, machine byte order)
S unsigned short (always 16 bit, machine byte order)
n unsigned short (always 16 bit, big endian byte order)
v unsigned short (always 16 bit, little endian byte order)
i signed integer (machine dependent size and byte order)
I unsigned integer (machine dependent size and byte order)
l signed long (always 32 bit, machine byte order)
L unsigned long (always 32 bit, machine byte order)
N unsigned long (always 32 bit, big endian byte order)
V unsigned long (always 32 bit, little endian byte order)
f float (machine dependent size and representation)
d double (machine dependent size and representation)
x NUL byte
X Back up one byte
@ NUL-fill to absolute position

Example 1. pack() format string

$binarydata = pack ("nvc*", 0x1234, 0x5678, 65, 66);

The resulting binary string will be 6 bytes long and contain the byte sequence 0x12, 0x34, 0x78, 0x56, 0x41, 0x42.

Note that the distinction between signed and unsigned values only affects the function unpack(), where as function pack() gives the same result for signed and unsigned format codes.

Also note that PHP internally stores integer values as signed values of a machine dependent size. If you give it an unsigned integer value too large to be stored that way it is converted to a float which often yields an undesired result.

show_source

(PHP 4 )

show_source -- Syntax highlighting of a file

Description

bool show_source ( string filename [, bool return])

This function is an alias to highlight_file(). For more information see the documentation there.

sleep

(PHP 3, PHP 4 )

sleep -- Delay execution

Description

void sleep ( int seconds)

The sleep function delays program execution for the given number of seconds.

See also usleep() and set_time_limit()

uniqid

(PHP 3, PHP 4 )

uniqid -- Generate a unique ID

Description

string uniqid ( string prefix [, bool lcg])

uniqid() returns a prefixed unique identifier based on the current time in microseconds. The prefix can be useful for instance if you generate identifiers simultaneously on several hosts that might happen to generate the identifier at the same microsecond. Prefix can be up to 114 characters long.

If the optional lcg parameter is TRUE, uniqid() will add additional "combined LCG" entropy at the end of the return value, which should make the results more unique.

With an empty prefix, the returned string will be 13 characters long. If lcg is TRUE, it will be 23 characters.

Note: The lcg parameter is only available in PHP 4 and PHP 3.0.13 and later.

If you need a unique identifier or token and you intend to give out that token to the user via the network (i.e. session cookies), it is recommended that you use something along the lines of

$token = md5(uniqid("")); // no prefix
$better_token = md5(uniqid(rand(),1)); // better, difficult to guess

This will create a 32 character identifier (a 128 bit hex number) that is extremely difficult to predict.

unpack

(PHP 3, PHP 4 )

unpack -- Unpack data from binary string

Description

array unpack ( string format, string data)

unpack() from binary string into array according to format. Returns array containing unpacked elements of binary string.

unpack() works slightly different from Perl as the unpacked data is stored in an associative array. To accomplish this you have to name the different format codes and separate them by a slash /.
Example 1. unpack() format string
$array = unpack ("c2chars/nint", $binarydata);
The resulting array will contain the entries "chars1", "chars2" and "int".

For an explanation of the format codes see also: pack()

Note that PHP internally stores integral values as signed. If you unpack a large unsigned long and it is of the same size as PHP internally stored values the result will be a negative number even though unsigned unpacking was specified.

usleep

(PHP 3, PHP 4 )

usleep -- Delay execution in microseconds

Description

void usleep ( int micro_seconds)

The usleep() function delays program execution for the given number of micro_seconds. A microsecond is one millionth of a second.

See also sleep() and set_time_limit().

Note: This function does not work on Windows systems.

LXI. mnoGoSearch Functions

Introduction

These functions allow you to access the mnoGoSearch (former UdmSearch) free search engine. mnoGoSearch is a full-featured search engine software for intranet and internet servers, distributed under the GNU license. mnoGoSearch has a number of unique features, which makes it appropriate for a wide range of applications from search within your site to a specialized search system such as cooking recipes or newspaper search, FTP archive search, news articles search, etc. It offers full-text indexing and searching for HTML, PDF, and text documents. mnoGoSearch consists of two parts. The first is an indexing mechanism (indexer). The purpose of the indexer is to walk through HTTP, FTP, NEWS servers or local files, recursively grabbing all the documents and storing meta-data about that documents in a SQL database in a smart and effective manner. After every document is referenced by its corresponding URL, meta-data is collected by the indexer for later use in a search process. The search is performed via Web interface. C, CGI, PHP and Perl search front ends are included.

More information about mnoGoSearch can be found at http://www.mnogosearch.ru/.

Requirements

Download mnoGosearch from http://www.mnogosearch.ru/ and install it on your system. You need at least version 3.1.10 of mnoGoSearch installed to use these functions.

Installation

In order to have these functions available, you must compile PHP with mnoGosearch support by using the --with-mnogosearch option. If you use this option without specifying the path to mnoGosearch, PHP will look for mnoGosearch under /usr/local/mnogosearch path by default. If you installed mnoGosearch at a different location you should specify it: --with-mnogosearch=DIR.

Note: PHP contains built-in MySQL access library, which can be used to access MySQL. It is known that mnoGoSearch is not compatible with this built-in library and can work only with generic MySQL libraries. Thus, if you use mnoGoSearch with MySQL, during PHP configuration you have to indicate the directory of your MySQL installation, that was used during mnoGoSearch configuration, i.e. for example: --with-mnogosearch --with-mysql=/usr.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

UDM_FIELD_URLID (integer)
UDM_FIELD_URL (integer)
UDM_FIELD_CONTENT (integer)
UDM_FIELD_TITLE (integer)
UDM_FIELD_KEYWORDS (integer)
UDM_FIELD_DESC (integer)
UDM_FIELD_DESCRIPTION (integer)
UDM_FIELD_TEXT (integer)
UDM_FIELD_SIZE (integer)
UDM_FIELD_RATING (integer)
UDM_FIELD_SCORE (integer)
UDM_FIELD_MODIFIED (integer)
UDM_FIELD_ORDER (integer)
UDM_FIELD_CRC (integer)
UDM_FIELD_CATEGORY (integer)
UDM_FIELD_LANG (integer)
UDM_FIELD_CHARSET (integer)
UDM_PARAM_PAGE_SIZE (integer)
UDM_PARAM_PAGE_NUM (integer)
UDM_PARAM_SEARCH_MODE (integer)
UDM_PARAM_CACHE_MODE (integer)
UDM_PARAM_TRACK_MODE (integer)
UDM_PARAM_PHRASE_MODE (integer)
UDM_PARAM_CHARSET (integer)
UDM_PARAM_LOCAL_CHARSET (integer)
UDM_PARAM_BROWSER_CHARSET (integer)
UDM_PARAM_STOPTABLE (integer)
UDM_PARAM_STOP_TABLE (integer)
UDM_PARAM_STOPFILE (integer)
UDM_PARAM_STOP_FILE (integer)
UDM_PARAM_WEIGHT_FACTOR (integer)
UDM_PARAM_WORD_MATCH (integer)
UDM_PARAM_MAX_WORD_LEN (integer)
UDM_PARAM_MAX_WORDLEN (integer)
UDM_PARAM_MIN_WORD_LEN (integer)
UDM_PARAM_MIN_WORDLEN (integer)
UDM_PARAM_ISPELL_PREFIXES (integer)
UDM_PARAM_ISPELL_PREFIX (integer)
UDM_PARAM_PREFIXES (integer)
UDM_PARAM_PREFIX (integer)
UDM_PARAM_CROSS_WORDS (integer)
UDM_PARAM_CROSSWORDS (integer)
UDM_PARAM_VARDIR (integer)
UDM_PARAM_DATADIR (integer)
UDM_PARAM_HLBEG (integer)
UDM_PARAM_HLEND (integer)
UDM_PARAM_SYNONYM (integer)
UDM_PARAM_SEARCHD (integer)
UDM_PARAM_QSTRING (integer)
UDM_PARAM_REMOTE_ADDR (integer)
UDM_LIMIT_CAT (integer)
UDM_LIMIT_URL (integer)
UDM_LIMIT_TAG (integer)
UDM_LIMIT_LANG (integer)
UDM_LIMIT_DATE (integer)
UDM_PARAM_FOUND (integer)
UDM_PARAM_NUM_ROWS (integer)
UDM_PARAM_WORDINFO (integer)
UDM_PARAM_WORD_INFO (integer)
UDM_PARAM_SEARCHTIME (integer)
UDM_PARAM_SEARCH_TIME (integer)
UDM_PARAM_FIRST_DOC (integer)
UDM_PARAM_LAST_DOC (integer)
UDM_MODE_ALL (integer)
UDM_MODE_ANY (integer)
UDM_MODE_BOOL (integer)
UDM_MODE_PHRASE (integer)
UDM_CACHE_ENABLED (integer)
UDM_CACHE_DISABLED (integer)
UDM_TRACK_ENABLED (integer)
UDM_TRACK_DISABLED (integer)
UDM_PHRASE_ENABLED (integer)
UDM_PHRASE_DISABLED (integer)
UDM_CROSS_WORDS_ENABLED (integer)
UDM_CROSSWORDS_ENABLED (integer)
UDM_CROSS_WORDS_DISABLED (integer)
UDM_CROSSWORDS_DISABLED (integer)
UDM_PREFIXES_ENABLED (integer)
UDM_PREFIX_ENABLED (integer)
UDM_ISPELL_PREFIXES_ENABLED (integer)
UDM_ISPELL_PREFIX_ENABLED (integer)
UDM_PREFIXES_DISABLED (integer)
UDM_PREFIX_DISABLED (integer)
UDM_ISPELL_PREFIXES_DISABLED (integer)
UDM_ISPELL_PREFIX_DISABLED (integer)
UDM_ISPELL_TYPE_AFFIX (integer)
UDM_ISPELL_TYPE_SPELL (integer)
UDM_ISPELL_TYPE_DB (integer)
UDM_ISPELL_TYPE_SERVER (integer)
UDM_MATCH_WORD (integer)
UDM_MATCH_BEGIN (integer)
UDM_MATCH_SUBSTR (integer)
UDM_MATCH_END (integer)

Table of Contents
udm_add_search_limit -- Add various search limits
udm_alloc_agent -- Allocate mnoGoSearch session
udm_api_version -- Get mnoGoSearch API version.
udm_cat_list -- Get all the categories on the same level with the current one.
udm_cat_path -- Get the path to the current category.
udm_check_charset -- Check if the given charset is known to mnogosearch
udm_check_stored -- Check connection to stored
udm_clear_search_limits -- Clear all mnoGoSearch search restrictions
udm_close_stored -- Close connection to stored
udm_crc32 -- Return CRC32 checksum of gived string
udm_errno -- Get mnoGoSearch error number
udm_error -- Get mnoGoSearch error message
udm_find -- Perform search
udm_free_agent -- Free mnoGoSearch session
udm_free_ispell_data -- Free memory allocated for ispell data
udm_free_res -- Free mnoGoSearch result
udm_get_doc_count -- Get total number of documents in database.
udm_get_res_field -- Fetch mnoGoSearch result field
udm_get_res_param -- Get mnoGoSearch result parameters
udm_load_ispell_data -- Load ispell data
udm_open_stored -- Open connection to stored
udm_set_agent_param -- Set mnoGoSearch agent session parameters

udm_add_search_limit

(PHP 4 >= 4.0.5)

udm_add_search_limit -- Add various search limits

Description

int udm_add_search_limit ( int agent, int var, string val)

udm_add_search_limit() returns TRUE on success, FALSE on error. Adds search restrictions.

agent - a link to Agent, received after call to udm_alloc_agent().

var - defines parameter, indicating limit.

val - defines value of the current parameter.

Possible var values:

UDM_LIMIT_URL - defines document URL limitations to limit search through subsection of database. It supports SQL % and _ LIKE wildcards, where % matches any number of characters, even zero characters, and _ matches exactly one character. E.g. http://my.domain.__/catalog may stand for http://my.domain.ru/catalog and http://my.domain.ua/catalog.
UDM_LIMIT_TAG - defines site TAG limitations. In indexer-conf you can assign specific TAGs to various sites and parts of a site. Tags in mnoGoSearch 3.1.x are lines, that may contain metasymbols % and _. Metasymbols allow searching among groups of tags. E.g. there are links with tags ABCD and ABCE, and search restriction is by ABC_ - the search will be made among both of the tags.
UDM_LIMIT_LANG - defines document language limitations.
UDM_LIMIT_CAT - defines document category limitations. Categories are similar to tag feature, but nested. So you can have one category inside another and so on. You have to use two characters for each level. Use a hex number going from 0-F or a 36 base number going from 0-Z. Therefore a top-level category like 'Auto' would be 01. If it has a subcategory like 'Ford', then it would be 01 (the parent category) and then 'Ford' which we will give 01. Put those together and you get 0101. If 'Auto' had another subcategory named 'VW', then it's id would be 01 because it belongs to the 'Ford' category and then 02 because it's the next category. So it's id would be 0102. If VW had a sub category called 'Engine' then it's id would start at 01 again and it would get the 'VW' id 02 and 'Auto' id of 01, making it 010201. If you want to search for sites under that category then you pass it cat=010201 in the url.
UDM_LIMIT_DATE - defines limitation by date document was modified.
Format of parameter value: a string with first character < or >, then with no space - date in unixtime format, for example:
Udm_Add_Search_Limit($udm,UDM_LIMIT_DATE,"<908012006");
If > character is used, then search will be restricted to those documents having modification date greater than entered. If <, then smaller.

udm_alloc_agent

(PHP 4 >= 4.0.5)

udm_alloc_agent -- Allocate mnoGoSearch session

Description

int udm_alloc_agent ( string dbaddr [, string dbmode])

udm_alloc_agent() returns mnogosearch agent identifier on success, FALSE on error. This function creates a session with database parameters.

dbaddr - URL-style database description. Options (type, host, database name, port, user and password) to connect to SQL database. Do not matter for built-in text files support. Format: DBAddr DBType:[//[DBUser[:DBPass]@]DBHost[:DBPort]]/DBName/ Currently supported DBType values are: mysql, pgsql, msql, solid, mssql, oracle, ibase. Actually, it does not matter for native libraries support. But ODBC users should specify one of supported values. If your database type is not supported, you may use "unknown" instead.

dbmode - You may select SQL database mode of words storage. When "single" is specified, all words are stored in the same table. If "multi" is selected, words will be located in different tables depending of their lengths. "multi" mode is usually faster but requires more tables in database. If "crc" mode is selected, mnoGoSearch will store 32 bit integer word IDs calculated by CRC32 algorythm instead of words. This mode requres less disk space and it is faster comparing with "single" and "multi" modes. "crc-multi" uses the same storage structure with the "crc" mode, but also stores words in different tables depending on words lengths like "multi" mode. Format: DBMode single/multi/crc/crc-multi

Note: dbaddr and dbmode must match those used during indexing.

Note: In fact this function does not open connection to database and thus does not check entered login and password. Actual connection to database and login/password verification is done by udm_find().

udm_api_version

(PHP 4 >= 4.0.5)

udm_api_version -- Get mnoGoSearch API version.

Description

int udm_api_version ( void)

udm_api_version() returns mnoGoSearch API version number. E.g. if mnoGoSearch 3.1.10 API is used, this function will return 30110.

This function allows user to identify which API functions are available, e.g. udm_get_doc_count() function is only available in mnoGoSearch 3.1.11 or later.

Example:

if (udm_api_version() >= 30111) {
   print  "Total number of urls in database: ".udm_get_doc_count($udm)."<br>\n";
   }

udm_cat_list

(PHP 4 >= 4.0.6)

udm_cat_list -- Get all the categories on the same level with the current one.

Description

array udm_cat_list ( int agent, string category)

udm_cat_list() returns array listing all categories of the same level as current category in the categories tree.

The function can be useful for developing categories tree browser.

Returns array with the following format:

The array consists of pairs. Elements with even index numbers contain category paths, odd elements contain corresponding category names.

  $array[0] will contain '020300'
  $array[1] will contain 'Audi'
  $array[2] will contain '020301'
  $array[3] will contain 'BMW'
  $array[4] will contain '020302'
  $array[5] will contain 'Opel'
  ...
etc.

Following is an example of displaying links of the current level in format:
  Audi
  BMW
  Opel
  ...

<?php
 $cat_list_arr = udm_cat_list($udm_agent,$cat);
 $cat_list = '';
 for ($i=0; $i<count($cat_list_arr); $i+=2) {
   $path = $cat_list_arr[$i];
   $name = $cat_list_arr[$i+1];
   $cat_list .= "<a href=\"$PHP_SELF?cat=$path\">$name</a><br>";
 }
?>

udm_cat_path

(PHP 4 >= 4.0.6)

udm_cat_path -- Get the path to the current category.

Description

array udm_cat_path ( int agent, string category)

udm_cat_path() returns array describing path in the categories tree from the tree root to the current category.

agent - agent link identifier.

category - current category - the one to get path to.

Returns array with the following format:

The array consists of pairs. Elements with even index numbers contain category paths, odd elements contain corresponding category names.

For example, the call $array=udm_cat_path($agent, '02031D'); may return the following array:

$array[0] will contain ''
$array[1] will contain 'Root'
$array[2] will contain '02'
$array[3] will contain 'Sport'
$array[4] will contain '0203'
$array[5] will contain 'Auto'
$array[4] will contain '02031D'
$array[5] will contain 'Ferrari'

Example 1. Specifying path to the current category in the following format: '> Root > Sport > Auto > Ferrari'

<?php
  $cat_path_arr = udm_cat_path($udm_agent,$cat);
  $cat_path = '';
  for ($i=0; $i<count($cat_path_arr); $i+=2) {
    $path = $cat_path_arr[$i];
    $name = $cat_path_arr[$i+1];
    $cat_path .= " > <a href=\"$PHP_SELF?cat=$path\">$name</a> ";
  }
?>

udm_error

(PHP 4 >= 4.0.5)

udm_error -- Get mnoGoSearch error message

Description

string udm_error ( int agent)

udm_error() returns mnoGoSearch error message, empty string if no error.

agent - link to agent identifier, received after call to udm_alloc_agent().

Receiving agent error message.

udm_find

(PHP 4 >= 4.0.5)

udm_find -- Perform search

Description

int udm_find ( int agent, string query)

udm_find() returns result link identifier on success, FALSE on error.

The search itself. The first argument - session, the next one - query itself. To find something just type words you want to find and press SUBMIT button. For example, "mysql odbc". You should not use quotes " in query, they are written here only to divide a query from other text. mnoGoSearch will find all documents that contain word "mysql" and/or word "odbc". Best documents having bigger weights will be displayed first. If you use search mode ALL, search will return documents that contain both (or more) words you entered. In case you use mode ANY, the search will return list of documents that contain any of the words you entered. If you want more advanced results you may use query language. You should select "bool" match mode in the search from.

mnoGoSearch understands the following boolean operators:

string udm_get_res_field ( int res, int row, int field)

udm_get_res_field() returns result field value on success, FALSE on error.

res - a link to result identifier, received after call to udm_find().

row - the number of the link on the current page. May have values from 0 to UDM_PARAM_NUM_ROWS-1.

field - field identifier, may have the following values:

UDM_FIELD_URL - document URL field
UDM_FIELD_CONTENT - document Content-type field (for example, text/html).
UDM_FIELD_CATEGORY - document category field. Use udm_cat_path() to get full path to current category from the categories tree root. (This parameter is available only in PHP 4.0.6 or later).
UDM_FIELD_TITLE - document title field.
UDM_FIELD_KEYWORDS - document keywords field (from META KEYWORDS tag).
UDM_FIELD_DESC - document description field (from META DESCRIPTION tag).
UDM_FIELD_TEXT - document body text (the first couple of lines to give an idea of what the document is about).
UDM_FIELD_SIZE - document size.
UDM_FIELD_URLID - unique URL ID of the link.
UDM_FIELD_RATING - page rating (as calculated by mnoGoSearch).
UDM_FIELD_MODIFIED - last-modified field in unixtime format.
UDM_FIELD_ORDER - the number of the current document in set of found documents.
UDM_FIELD_CRC - document CRC.

udm_get_res_param

(PHP 4 >= 4.0.5)

udm_get_res_param -- Get mnoGoSearch result parameters

Description

string udm_get_res_param ( int res, int param)

udm_get_res_param() returns result parameter value on success, FALSE on error.

res - a link to result identifier, received after call to udm_find().

param - parameter identifier, may have the following values:

UDM_PARAM_NUM_ROWS - number of received found links on the current page. It is equal to UDM_PARAM_PAGE_SIZE for all search pages, on the last page - the rest of links.
UDM_PARAM_FOUND - total number of results matching the query.
UDM_PARAM_WORDINFO - information on the words found. E.g. search for "a good book" will return "a: stopword, good:5637, book: 120"
UDM_PARAM_SEARCHTIME - search time in seconds.
UDM_PARAM_FIRST_DOC - the number of the first document displayed on current page.
UDM_PARAM_LAST_DOC - the number of the last document displayed on current page.

udm_load_ispell_data

(PHP 4 >= 4.0.5)

udm_load_ispell_data -- Load ispell data

Description

int udm_load_ispell_data ( int agent, int var, string val1, string val2, int flag)

udm_load_ispell_data() loads ispell data. Returns TRUE on success, FALSE on error.

agent - agent link identifier, received after call to udm_alloc_agent().

var - parameter, indicating the source for ispell data. May have the following values:

After using this function to free memory allocated for ispell data, please use udm_free_ispell_data(), even if you use UDM_ISPELL_TYPE_SERVER mode.

The fastest mode is UDM_ISPELL_TYPE_SERVER. UDM_ISPELL_TYPE_TEXT is slower and UDM_ISPELL_TYPE_DB is the slowest. The above pattern is TRUE for mnoGoSearch 3.1.10 - 3.1.11. It is planned to speed up DB mode in future versions and it is going to be faster than TEXT mode.

UDM_ISPELL_TYPE_DB - indicates that ispell data should be loaded from SQL. In this case, parameters val1 and val2 are ignored and should be left blank. flag should be equal to 1.
Note: flag indicates that after loading ispell data from defined source it sould be sorted (it is necessary for correct functioning of ispell). In case of loading ispell data from files there may be several calls to udm_load_ispell_data(), and there is no sense to sort data after every call, but only after the last one. Since in db mode all the data is loaded by one call, this parameter should have the value 1. In this mode in case of error, e.g. if ispell tables are absent, the function will return FALSE and code and error message will be accessible through udm_error() and udm_errno().
Example:
if (! udm_load_ispell_data($udm,UDM_ISPELL_TYPE_DB,'','',1)) { printf("Error #%d: '%s'\n", udm_errno($udm), udm_error($udm)); exit; }

UDM_ISPELL_TYPE_AFFIX - indicates that ispell data should be loaded from file and initiates loading affixes file. In this case val1 defines double letter language code for which affixes are loaded, and val2 - file path. Please note, that if a relative path entered, the module looks for the file not in UDM_CONF_DIR, but in relation to current path, i.e. to the path where the script is executed. In case of error in this mode, e.g. if file is absent, the function will return FALSE, and an error message will be displayed. Error message text cannot be accessed through udm_error() and udm_errno(), since those functions can only return messages associated with SQL. Please, see flag parameter description in UDM_ISPELL_TYPE_DB.

Example:

if ((! udm_load_ispell_data($udm,UDM_ISPELL_TYPE_AFFIX,'en','/opt/ispell/en.aff',0)) ||
        (! udm_load_ispell_data($udm,UDM_ISPELL_TYPE_AFFIX,'ru','/opt/ispell/ru.aff',0)) ||
        (! udm_load_ispell_data($udm,UDM_ISPELL_TYPE_SPELL,'en','/opt/ispell/en.dict',0)) ||
        (! udm_load_ispell_data($udm,UDM_ISPELL_TYPE_SPELL,'ru','/opt/ispell/ru.dict',1))) {
     exit;
     }

Note: flag is equal to 1 only in the last call.

UDM_ISPELL_TYPE_SPELL - indicates that ispell data should be loaded from file and initiates loading of ispell dictionary file. In this case val1 defines double letter language code for which affixes are loaded, and val2 - file path. Please note, that if a relative path entered, the module looks for the file not in UDM_CONF_DIR, but in relation to current path, i.e. to the path where the script is executed. In case of error in this mode, e.g. if file is absent, the function will return FALSE, and an error message will be displayed. Error message text cannot be accessed through udm_error() and udm_errno(), since those functions can only return messages associated with SQL. Please, see flag parameter description in UDM_ISPELL_TYPE_DB.

if ((! Udm_Load_Ispell_Data($udm,UDM_ISPELL_TYPE_AFFIX,'en','/opt/ispell/en.aff',0)) ||
        (! Udm_Load_Ispell_Data($udm,UDM_ISPELL_TYPE_AFFIX,'ru','/opt/ispell/ru.aff',0)) ||
        (! Udm_Load_Ispell_Data($udm,UDM_ISPELL_TYPE_SPELL,'en','/opt/ispell/en.dict',0)) ||
        (! Udm_Load_Ispell_Data($udm,UDM_ISPELL_TYPE_SPELL,'ru','/opt/ispell/ru.dict',1))) {
      exit;
      }

Note: flag is equal to 1 only in the last call.

UDM_ISPELL_TYPE_SERVER - enables spell server support. val1 parameter indicates address of the host running spell server. val2 ` is not used yet, but in future releases it is going to indicate number of port used by spell server. flag parameter in this case is not needed since ispell data is stored on spellserver already sorted.
Spelld server reads spell-data from a separate configuration file (/usr/local/mnogosearch/etc/spelld.conf by default), sorts it and stores in memory. With clients server communicates in two ways: to indexer all the data is transferred (so that indexer starts faster), from search.cgi server receives word to normalize and then passes over to client (search.cgi) list of normalized word forms. This allows fastest, compared to db and text modes processing of search queries (by omitting loading and sorting all the spell data).
udm_load_ispell_data() function in UDM_ISPELL_TYPE_SERVER mode does not actually load ispell data, but only defines server address. In fact, server is automatically used by udm_find() function when performing search. In case of errors, e.g. if spellserver is not running or invalid host indicated, there are no messages returned and ispell conversion does not work.
Note: This function is available in mnoGoSearch 3.1.12 or later.
Example:
if (!udm_load_ispell_data($udm,UDM_ISPELL_TYPE_SERVER,'','',1)) { printf("Error loading ispell data from server<br>\n"); exit; }

udm_open_stored

(PHP 4 >= 4.2.0)

udm_open_stored -- Open connection to stored

Description

int udm_open_stored ( int agent, string storedaddr)

Warning

This function is currently not documented; only the argument list is available.

udm_set_agent_param

(PHP 4 >= 4.0.5)

udm_set_agent_param -- Set mnoGoSearch agent session parameters

Description

int udm_set_agent_param ( int agent, int var, string val)

udm_set_agent_param() returns TRUE on success, FALSE on error. Defines mnoGoSearch session parameters.

The following parameters and their values are available:

UDM_PARAM_PAGE_NUM - used to choose search results page number (results are returned by pages beginning from 0, with UDM_PARAM_PAGE_SIZE results per page).
UDM_PARAM_PAGE_SIZE - number of search results displayed on one page.
UDM_PARAM_SEARCH_MODE - search mode. The following values available: UDM_MODE_ALL - search for all words; UDM_MODE_ANY - search for any word; UDM_MODE_PHRASE - phrase search; UDM_MODE_BOOL - boolean search. See udm_find() for details on boolean search.
UDM_PARAM_CACHE_MODE - turns on or off search result cache mode. When enabled, the search engine will store search results to disk. In case a similar search is performed later, the engine will take results from the cache for faster performance. Available values: UDM_CACHE_ENABLED, UDM_CACHE_DISABLED.
UDM_PARAM_TRACK_MODE - turns on or off trackquery mode. Since version 3.1.2 mnoGoSearch has a query tracking support. Note that tracking is implemented in SQL version only and not available in built-in database. To use tracking, you have to create tables for tracking support. For MySQL, use create/mysql/track.txt. When doing a search, front-end uses those tables to store query words, a number of found documents and current UNIX timestamp in seconds. Available values: UDM_TRACK_ENABLED, UDM_TRACK_DISABLED.
UDM_PARAM_PHRASE_MODE - defines whether index database using phrases ("phrase" parameter in indexer.conf). Possible values: UDM_PHRASE_ENABLED and UDM_PHRASE_DISABLED. Please note, that if phrase search is enabled (UDM_PHRASE_ENABLED), it is still possible to do search in any mode (ANY, ALL, BOOL or PHRASE). In 3.1.10 version of mnoGoSearch phrase search is supported only in sql and built-in database modes, while beginning with 3.1.11 phrases are supported in cachemode as well.
Examples of phrase search:
"Arizona desert" - This query returns all indexed documents that contain "Arizona desert" as a phrase. Notice that you need to put double quotes around the phrase
UDM_PARAM_CHARSET - defines local charset. Available values: set of charsets supported by mnoGoSearch, e.g. koi8-r, cp1251, ...
UDM_PARAM_STOPFILE - Defines name and path to stopwords file. (There is a small difference with mnoGoSearch - while in mnoGoSearch if relative path or no path entered, it looks for this file in relation to UDM_CONF_DIR, the module looks for the file in relation to current path, i.e. to the path where the php script is executed.)
UDM_PARAM_STOPTABLE - Load stop words from the given SQL table. You may use several StopwordTable commands. This command has no effect when compiled without SQL database support.
UDM_PARAM_WEIGHT_FACTOR - represents weight factors for specific document parts. Currently body, title, keywords, description, url are supported. To activate this feature please use degrees of 2 in *Weight commands of the indexer.conf. Let's imagine that we have these weights:

  URLWeight     1
  BodyWeight    2
  TitleWeight   4
  KeywordWeight 8
  DescWeight    16

As far as indexer uses bit OR operation for word weights when some word presents several time in the same document, it is possible at search time to detect word appearance in different document parts. Word which appears only in the body will have 00000010 argegate weight (in binary notation). Word used in all document parts will have 00011111 aggregate weight.
This parameter's value is a string of hex digits ABCDE. Each digit is a factor for corresponding bit in word weight. For the given above weights configuration:

   E is a factor for weight 1  (URL Weight bit)
   D is a factor for weight 2  (BodyWeight bit)
   C is a factor for weight 4  (TitleWeight bit)
   B is a factor for weight 8  (KeywordWeight bit)
   A is a factor for weight 16 (DescWeight bit)

Examples:
UDM_PARAM_WEIGHT_FACTOR=00001 will search through URLs only.
UDM_PARAM_WEIGHT_FACTOR=00100 will search through Titles only.
UDM_PARAM_WEIGHT_FACTOR=11100 will search through Title,Keywords,Description but not through URL and Body.
UDM_PARAM_WEIGHT_FACTOR=F9421 will search through:

    Description with factor 15  (F hex)
    Keywords with factor 9
    Title with factor  4
    Body with factor 2
    URL with factor 1

If UDM_PARAM_WEIGHT_FACTOR variable is ommited, original weight value is taken to sort results. For a given above weight configuration it means that document description has a most big weight 16.
UDM_PARAM_WORD_MATCH - word match. You may use this parameter to choose word match type. This feature works only in "single" and "multi" modes using SQL based and built-in database. It does not work in cachemode and other modes since they use word CRC and do not support substring search. Available values:
UDM_MATCH_BEGIN - word beginning match;
UDM_MATCH_END - word ending match;
UDM_MATCH_WORD - whole word match;
UDM_MATCH_SUBSTR - word substring match.
UDM_PARAM_MIN_WORD_LEN - defines minimal word length. Any word shorter this limit is considered to be a stopword. Please note that this parameter value is inclusive, i.e. if UDM_PARAM_MIN_WORD_LEN=3, a word 3 characters long will not be considered a stopword, while a word 2 characters long will be. Default value is 1.
UDM_PARAM_ISPELL_PREFIXES - Possible values: UDM_PREFIXES_ENABLED and UDM_PREFIXES_DISABLED, that respectively enable or disable using prefixes. E.g. if a word "tested" is in search query, also words like "test", "testing", etc. Only suffixes are supported by default. Prefixes usually change word meanings, for example if somebody is searching for the word "tested" one hardly wants "untested" to be found. Prefixes support may also be found useful for site's spelling checking purposes. In order to enable ispell, you have to load ispell data with udm_load_ispell_data().
UDM_PARAM_CROSS_WORDS - enables or disables crosswords support. Possible values: UDM_CROSS_WORDS_ENABLED and UDM_CROSS_WORDS_DISABLED.
The corsswords feature allows to assign words between <a href="xxx"> and </a> also to a document this link leads to. It works in SQL database mode and is not supported in built-in database and Cachemode.
Note: Crosswords are supported only in mnoGoSearch 3.1.11 or later.
UDM_PARAM_VARDIR - specifies a custom path to directory where indexer stores data when using built-in database and in cache mode. By default /var directory of mnoGoSearch installation is used. Can have only string values. The parameter is available in PHP 4.1.0 or later.
UDM_PARAM_VARDIR - specifies a custom path to directory where indexer stores data when using built-in database and in cache mode. By default /var directory of mnoGoSearch installation is used. Can have only string values. The parameter is available in PHP 4.1.0 or later.

LXII. mSQL functions

Introduction

These functions allow you to access mSQL database servers. More information about mSQL can be found at http://www.hughes.com.au/.

Requirements

Installation

In order to have these functions available, you must compile PHP with msql support by using the --with-msql[=dir] option. The default location is /usr/local/Hughes.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. mSQL configuration options

Name	Default	Changeable
msql.allow_persistent	"On"	PHP_INI_SYSTEM
msql.max_persistent	"-1"	PHP_INI_SYSTEM
msql.max_links	"-1"	PHP_INI_SYSTEM

For further details and definition of the PHP_INI_* constants see ini_set().

Here is a short explanation of the configuration directives.

msql.allow_persistent boolean: Whether to allow persistent mSQL connections.
msql.max_persistent integer: The maximum number of persistent mSQL connections per process.
msql.max_links integer: The maximum number of mSQL connections per process, including persistent connections.

Resource Types

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

MSQL_ASSOC (integer)
MSQL_NUM (integer)
MSQL_BOTH (integer)

Table of Contents
msql_affected_rows -- Returns number of affected rows
msql_close -- Close mSQL connection
msql_connect -- Open mSQL connection
msql_create_db -- Create mSQL database
msql_createdb -- Create mSQL database
msql_data_seek -- Move internal row pointer
msql_dbname -- Get current mSQL database name
msql_drop_db -- Drop (delete) mSQL database
msql_dropdb -- Drop (delete) mSQL database
msql_error -- Returns error message of last msql call
msql_fetch_array -- Fetch row as array
msql_fetch_field -- Get field information
msql_fetch_object -- Fetch row as object
msql_fetch_row -- Get row as enumerated array
msql_field_seek -- Set field offset
msql_fieldflags -- Get field flags
msql_fieldlen -- Get field length
msql_fieldname -- Get field name
msql_fieldtable -- Get table name for field
msql_fieldtype -- Get field type
msql_free_result -- Free result memory
msql_freeresult -- Free result memory
msql_list_dbs -- List mSQL databases on server
msql_list_fields -- List result fields
msql_list_tables -- List tables in an mSQL database
msql_listdbs -- List mSQL databases on server
msql_listfields -- List result fields
msql_listtables -- List tables in an mSQL database
msql_num_fields -- Get number of fields in result
msql_num_rows -- Get number of rows in result
msql_numfields -- Get number of fields in result
msql_numrows -- Get number of rows in result
msql_pconnect -- Open persistent mSQL connection
msql_query -- Send mSQL query
msql_regcase -- Make regular expression for case insensitive match
msql_result -- Get result data
msql_select_db -- Select mSQL database
msql_selectdb -- Select mSQL database
msql_tablename -- Get table name of field
msql -- Send mSQL query

msql_affected_rows

(PHP 3>= 3.0.6, PHP 4 )

msql_affected_rows -- Returns number of affected rows

Description

int msql_affected_rows ( int query_identifier)

Returns number of affected ("touched") rows by a specific query (i.e. the number of rows returned by a SELECT, the number of rows modified by an update, or the number of rows removed by a delete).

msql_close

(PHP 3, PHP 4 )

msql_close -- Close mSQL connection

Description

int msql_close ( int link_identifier)

Returns TRUE on success, FALSE on error.

msql_close() closes the link to a mSQL database that's associated with the specified link identifier. If the link identifier isn't specified, the last opened link is assumed.

Note that this isn't usually necessary, as non-persistent open links are automatically closed at the end of the script's execution.

msql_dbname

(PHP 3, PHP 4 )

msql_dbname -- Get current mSQL database name

Description

string msql_dbname ( int query_identifier, int i)

msql_dbname() returns the database name stored in position i of the result pointer returned from the msql_listdbs() function. The msql_numrows() function can be used to determine how many database names are available.

msql_drop_db

(PHP 3, PHP 4 )

msql_drop_db -- Drop (delete) mSQL database

Description

int msql_drop_db ( string database_name, int link_identifier)

Returns TRUE on success or FALSE on failure.

msql_drop_db() attempts to drop (remove) an entire database from the server associated with the specified link identifier.

msql_dropdb

msql_dropdb -- Drop (delete) mSQL database

Description

See msql_drop_db().

msql_error

(PHP 3, PHP 4 )

msql_error -- Returns error message of last msql call

Description

string msql_error ( [int link_identifier])

Errors coming back from the mSQL database backend no longer issue warnings. Instead, use these functions to retrieve the error string.

msql_fetch_array

(PHP 3, PHP 4 )

msql_fetch_array -- Fetch row as array

Description

int msql_fetch_array ( int query_identifier [, int result_type])

Returns an array that corresponds to the fetched row, or FALSE if there are no more rows.

msql_free_result() frees the memory associated with query_identifier. When PHP completes a request, this memory is freed automatically, so you only need to call this function when you want to make sure you don't use too much memory while the script is running.

msql_freeresult

msql_freeresult -- Free result memory

int msql_list_tables ( string database)

int msql_pconnect ( [string server [, string username [, string password]]])

Returns a positive mSQL persistent link identifier on success, or FALSE on error.

msql_pconnect() acts very much like msql_connect() with two major differences.

First, when connecting, the function would first try to find a (persistent) link that's already open with the same host. If one is found, an identifier for it will be returned instead of opening a new connection.

Second, the connection to the SQL server will not be closed when the execution of the script ends. Instead, the link will remain open for future use (msql_close() will not close links established by msql_pconnect()).

This type of links is therefore called 'persistent'.

msql_query

(PHP 3, PHP 4 )

msql_query -- Send mSQL query

Description

int msql_query ( string query, int link_identifier)

msql_query() sends a query to the currently active database on the server that's associated with the specified link identifier. If the link identifier isn't specified, the last opened link is assumed. If no link is open, the function tries to establish a link as if msql_connect() was called, and use it.

Returns a positive mSQL query identifier on success, or FALSE on error.

Example 1. msql_query()

<?php 
$link = msql_connect("dbserver")
   or die("unable to connect to msql server: ".msql_error());
msql_select_db("db", $link)
   or die("unable to select database 'db': ".msql_error());

$result = msql_query("SELECT * FROM table WHERE id=1", $link);
if (!$result) {
   die("query failed: ".msql_error());
}

while ($row = msql_fetch_array($result)) {
    echo $row["id"];
}
?>

msql_regcase

msql_regcase -- Make regular expression for case insensitive match

Description

See sql_regcase().

msql_result

(PHP 3, PHP 4 )

msql_result -- Get result data

Description

int msql_result ( int query_identifier, int i, mixed field)

Returns the contents of the cell at the row and offset in the specified mSQL result set.

msql_result() returns the contents of one cell from a mSQL result set. The field argument can be the field's offset, or the field's name, or the field's table dot field's name (fieldname.tablename). If the column name has been aliased ('select foo as bar from ...'), use the alias instead of the column name.

When working on large result sets, you should consider using one of the functions that fetch an entire row (specified below). As these functions return the contents of multiple cells in one function call, they're MUCH quicker than msql_result(). Also, note that specifying a numeric offset for the field argument is much quicker than specifying a fieldname or tablename.fieldname argument.

Recommended high-performance alternatives: msql_fetch_row(), msql_fetch_array(), and msql_fetch_object().

msql_select_db

(PHP 3, PHP 4 )

msql_select_db -- Select mSQL database

Description

int msql_select_db ( string database_name, int link_identifier)

Returns TRUE on success, FALSE on error.

msql_select_db() sets the current active database on the server that's associated with the specified link identifier. If no link identifier is specified, the last opened link is assumed. If no link is open, the function will try to establish a link as if msql_connect() was called, and use it.

Every subsequent call to msql_query() will be made on the active database.

msql_selectdb

msql_selectdb -- Select mSQL database

Description

See msql_select_db().

msql_tablename

(PHP 3, PHP 4 )

msql_tablename -- Get table name of field

Description

string msql_tablename ( int query_identifier, int field)

msql_tablename() takes a result pointer returned by the msql_list_tables() function as well as an integer index and returns the name of a table. The msql_numrows() function may be used to determine the number of tables in the result pointer.
Example 1. msql_tablename() example
<?php msql_connect ("localhost"); $result = msql_list_tables ("wisconsin"); $i = 0; while ($i < msql_numrows ($result)) { $tb_names[$i] = msql_tablename ($result, $i); echo $tb_names[$i] . "<BR>"; $i++; } ?>

msql

(PHP 3, PHP 4 )

msql -- Send mSQL query

Description

int msql ( string database, string query, int link_identifier)

Returns a positive mSQL query identifier to the query result, or FALSE on error.

msql() selects a database and executes a query on it. If the optional link identifier isn't specified, the function will try to find an open link to the mSQL server and if no such link is found it'll try to create one as if msql_connect() was called with no arguments (see msql_connect()).

LXIII. MySQL Functions

Introduction

These functions allow you to access MySQL database servers. More information about MySQL can be found at http://www.mysql.com/.

Documentation for MySQL can be found at http://www.mysql.com/documentation/.

Requirements

In order to have these functions available, you must compile PHP with MySQL support.

Installation

By using the --with-mysql configuration option you enable PHP to access MySQL databases. If you use this option without specifying the path to MySQL, PHP will use the built-in MySQL client libraries. With PHP4 MySQL support is always enabled; if you don't specify the configure option, the bundled libraries are used. Users who run other applications that use MySQL (for example, running PHP 3 and PHP 4 as concurrent apache modules, or auth-mysql) should always specify the path to MySQL: --with-mysql=/path/to/mysql. This will force PHP to use the client libraries installed by MySQL, avoiding any conflicts.

Warning

Crashes and startup problems of PHP may be encountered when loading this extension in conjunction with the recode extension. See the recode extension for more information.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. MySQL Configuration Options

Name	Default	Changeable
mysql.allow_persistent	"On"	PHP_INI_SYSTEM
mysql.max_persistent	"-1"	PHP_INI_SYSTEM
mysql.max_links	"-1"	PHP_INI_SYSTEM
mysql.default_port	NULL	PHP_INI_ALL
mysql.default_socket	NULL	PHP_INI_ALL
mysql.default_host	NULL	PHP_INI_ALL
mysql.default_user	NULL	PHP_INI_ALL
mysql.default_password	NULL	PHP_INI_ALL
mysql.connect_timeout	"0"	PHP_INI_SYSTEM

For further details and definition of the PHP_INI_* constants see ini_set().

Here is a short explanation of the configuration directives.

mysql.allow_persistent boolean: Whether to allow persistent connections to MySQL.
mysql.max_persistent integer: The maximum number of persistent MySQL connections per process.
mysql.max_links integer: The maximum number of MySQL connections per process, including persistent connections.
mysql.default_port string: The default TCP port number to use when connecting to the database server if no other port is specified. If no default is specified, the port will be obtained from the MYSQL_TCP_PORT environment variable, the mysql-tcp entry in /etc/services or the compile-time MYSQL_PORT constant, in that order. Win32 will only use the MYSQL_PORT constant.
mysql.default_socket string: The default socket name to use when connecting to a local database server if no other socket name is specified.
mysql.default_host string: The default server host to use when connecting to the database server if no other host is specified. Doesn't apply in safe mode.
mysql.default_user string: The default user name to use when connecting to the database server if no other name is specified. Doesn't apply in safe mode.
mysql.default_password string: The default password to use when connecting to the database server if no other password is specified. Doesn't apply in safe mode.
mysql.connect_timeout integer: Connect timeout in seconds. On Linux this timeout is also used for waiting for the first answer from the server.

Resource Types

There are two resource types used in the MySQL module. The first one is the link identifier for a database connection, the second a resource which holds the result of a query.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

Since PHP 4.3.0 it is possible to specify additional client flags for the mysql_connect() and mysql_pconnect() functions. The following constants are defined:

Table 2. MySQL client constants

constant	description
MYSQL_CLIENT_COMPRESS	use compression protocol
MYSQL_CLIENT_IGNORE_SPACE	Allow space after function names
MYSQL_CLIENT_INTERACTIVE	Allow interactive_timeout seconds (instead of wait_timeout) of inactivity before closing the connection.

The function mysql_fetch_array() uses a constant for the different types of result arrays. The following constants are defined:

Table 3. MySQL fetch constants

constant	description
MYSQL_ASSOC	Columns are returned into the array having the fieldname as the array index.
MYSQL_BOTH	Columns are returned into the array having both a numerical index and the fieldname as the array index.
MYSQL_NUM	Columns are returned into the array having a numerical index to the fields. This index starts with 0, the first field in the result.

Examples

This simple example shows how to connect, execute a query, print resulting rows and disconnect from a MySQL database.
Example 1. MySQL extension overview example
<?php /* Connecting, selecting database */ $link = mysql_connect("mysql_host", "mysql_user", "mysql_password") or die("Could not connect"); print "Connected successfully"; mysql_select_db("my_database") or die("Could not select database"); /* Performing SQL query */ $query = "SELECT * FROM my_table"; $result = mysql_query($query) or die("Query failed"); /* Printing results in HTML */ print "<table>\n"; while ($line = mysql_fetch_array($result, MYSQL_ASSOC)) { print "\t<tr>\n"; foreach ($line as $col_value) { print "\t\t<td>$col_value</td>\n"; } print "\t</tr>\n"; } print "</table>\n"; /* Free resultset */ mysql_free_result($result); /* Closing connection */ mysql_close($link); ?>

Table of Contents
mysql_affected_rows -- Get number of affected rows in previous MySQL operation
mysql_change_user -- Change logged in user of the active connection
mysql_client_encoding -- Returns the name of the character set
mysql_close -- Close MySQL connection
mysql_connect -- Open a connection to a MySQL Server
mysql_create_db -- Create a MySQL database
mysql_data_seek -- Move internal result pointer
mysql_db_name -- Get result data
mysql_db_query -- Send a MySQL query
mysql_drop_db -- Drop (delete) a MySQL database
mysql_errno -- Returns the numerical value of the error message from previous MySQL operation
mysql_error -- Returns the text of the error message from previous MySQL operation
mysql_escape_string -- Escapes a string for use in a mysql_query.
mysql_fetch_array -- Fetch a result row as an associative array, a numeric array, or both.
mysql_fetch_assoc -- Fetch a result row as an associative array
mysql_fetch_field -- Get column information from a result and return as an object
mysql_fetch_lengths -- Get the length of each output in a result
mysql_fetch_object -- Fetch a result row as an object
mysql_fetch_row -- Get a result row as an enumerated array
mysql_field_flags -- Get the flags associated with the specified field in a result
mysql_field_len -- Returns the length of the specified field
mysql_field_name -- Get the name of the specified field in a result
mysql_field_seek -- Set result pointer to a specified field offset
mysql_field_table -- Get name of the table the specified field is in
mysql_field_type -- Get the type of the specified field in a result
mysql_free_result -- Free result memory
mysql_get_client_info -- Get MySQL client info
mysql_get_host_info -- Get MySQL host info
mysql_get_proto_info -- Get MySQL protocol info
mysql_get_server_info -- Get MySQL server info
mysql_info -- Get information about the most recent query
mysql_insert_id -- Get the ID generated from the previous INSERT operation
mysql_list_dbs -- List databases available on a MySQL server
mysql_list_fields -- List MySQL result fields
mysql_list_processes -- List MySQL processes
mysql_list_tables -- List tables in a MySQL database
mysql_num_fields -- Get number of fields in result
mysql_num_rows -- Get number of rows in result
mysql_pconnect -- Open a persistent connection to a MySQL server
mysql_ping -- Ping a server connection or reconnect if there is no connection
mysql_query -- Send a MySQL query
mysql_real_escape_string -- Escapes special characters in a string for use in a SQL statement, taking into account the current charset of the connection.
mysql_result -- Get result data
mysql_select_db -- Select a MySQL database
mysql_stat -- Get current system status
mysql_tablename -- Get table name of field
mysql_thread_id -- Return the current thread ID
mysql_unbuffered_query -- Send an SQL query to MySQL, without fetching and buffering the result rows

mysql_affected_rows

(PHP 3, PHP 4 )

mysql_affected_rows -- Get number of affected rows in previous MySQL operation

Description

int mysql_affected_rows ( [resource link_identifier])

mysql_affected_rows() returns the number of rows affected by the last INSERT, UPDATE or DELETE query associated with link_identifier. If the link identifier isn't specified, the last link opened by mysql_connect() is assumed.

Note: If you are using transactions, you need to call mysql_affected_rows() after your INSERT, UPDATE, or DELETE query, not after the commit.

If the last query was a DELETE query with no WHERE clause, all of the records will have been deleted from the table but this function will return zero.

Note: When using UPDATE, MySQL will not update columns where the new value is the same as the old value. This creates the possiblity that mysql_affected_rows() may not actually equal the number of rows matched, only the number of rows that were literally affected by the query.

mysql_affected_rows() does not work with SELECT statements; only on statements which modify records. To retrieve the number of rows returned by a SELECT, use mysql_num_rows().

If the last query failed, this function will return -1.
Example 1. Delete-Query
<?php /* connect to database */ mysql_pconnect("localhost", "mysql_user", "mysql_password") or die ("Could not connect"); /* this should return the correct numbers of deleted records */ mysql_query("DELETE FROM mytable WHERE id < 10"); printf ("Records deleted: %d\n", mysql_affected_rows()); /* without a where clause in a delete statement, it should return 0 */ mysql_query("DELETE FROM mytable"); printf ("Records deleted: %d\n", mysql_affected_rows()); ?>
The above example would produce the following output:
Records deleted: 10 Records deleted: 0

Example 2. Update-Query
<?php /* connect to database */ mysql_pconnect("localhost", "mysql_user", "mysql_password") or die ("Could not connect"); /* Update records */ mysql_query("UPDATE mytable SET used=1 WHERE id < 10"); printf ("Updated records: %d\n", mysql_affected_rows()); mysql_query("COMMIT"); ?>
The above example would produce the following output:
Updated Records: 10

mysql_change_user

(PHP 3>= 3.0.13)

mysql_change_user -- Change logged in user of the active connection

Description

int mysql_change_user ( string user, string password [, string database [, resource link_identifier]])

mysql_change_user() changes the logged in user of the current active connection, or the connection given by the optional link_identifier parameter. If a database is specified, this will be the current database after the user has been changed. If the new user and password authorization fails, the current connected user stays active. Returns TRUE on success or FALSE on failure.

Note: This function was introduced in PHP 3.0.13 and requires MySQL 3.23.3 or higher. It is not available in PHP 4.

mysql_client_encoding

(PHP 4 CVS only)

mysql_client_encoding -- Returns the name of the character set

Description

int mysql_client_encoding ( [resource link_identifier])

mysql_client_encoding() returns the default character set name for the current connection.

Example 1. mysql_client_encoding() example

<?php
$link = mysql_connect('localhost', 'mysql_user', 'mysql_password');
$charset = mysql_client_encoding($link);
printf ("current character set is %s\n", $charset);
?>

The above example would produce the following output:
current character set is latin1

mysql_close

(PHP 3, PHP 4 )

mysql_close -- Close MySQL connection

Description

bool mysql_close ( [resource link_identifier])

Returns TRUE on success or FALSE on failure.

mysql_close() closes the connection to the MySQL server that's associated with the specified link identifier. If link_identifier isn't specified, the last opened link is used.

Using mysql_close() isn't usually necessary, as non-persistent open links are automatically closed at the end of the script's execution. See also freeing resources.

Note: mysql_close() will not close persistent links created by mysql_pconnect().

Example 1. MySQL close example

<?php
    $link = mysql_connect("localhost", "mysql_user", "mysql_password")
        or exit("Could not connect");
    print ("Connected successfully");
    mysql_close($link);
?>

See also: mysql_connect(), and mysql_pconnect().

mysql_connect

(PHP 3, PHP 4 )

mysql_connect -- Open a connection to a MySQL Server

Description

resource mysql_connect ( [string server [, string username [, string password [, bool new_link [, int client_flags]]]]])

Returns a MySQL link identifier on success, or FALSE on failure.

mysql_connect() establishes a connection to a MySQL server. The following defaults are assumed for missing optional parameters: server = 'localhost:3306', username = name of the user that owns the server process and password = empty password.

The server parameter can also include a port number. eg. "hostname:port" or a path to a socket eg. ":/path/to/socket" for the localhost.

Note: Support for ":port" was added in PHP 3.0B4.
Support for ":/path/to/socket" was added in PHP 3.0.10.
You can suppress the error message on failure by prepending a @ to the function name.

If a second call is made to mysql_connect() with the same arguments, no new link will be established, but instead, the link identifier of the already opened link will be returned. The new_link parameter modifies this behavior and makes mysql_connect() always open a new link, even if mysql_connect() was called before with the same parameters. The client_flags parameter can be a combination of the constants MYSQL_CLIENT_SSL, MYSQL_CLIENT_COMPRESS, MYSQL_CLIENT_IGNORE_SPACE or MYSQL_CLIENT_INTERACTIVE.

Note: The new_link parameter became available in PHP 4.2.0
The client_flags parameter became available in PHP 4.3.0

The link to the server will be closed as soon as the execution of the script ends, unless it's closed earlier by explicitly calling mysql_close().

Example 1. MySQL connect example

<?php
    $link = mysql_connect("localhost", "mysql_user", "mysql_password")
        or die("Could not connect");
    print ("Connected successfully");
    mysql_close($link);
?>

mysql_create_db

(PHP 3, PHP 4 )

mysql_create_db -- Create a MySQL database

Description

bool mysql_create_db ( string database name [, resource link_identifier])

mysql_create_db() attempts to create a new database on the server associated with the specified link identifier.

Returns TRUE on success or FALSE on failure.

Example 1. MySQL create database example

<?php
    $link = mysql_pconnect("localhost", "mysql_user", "mysql_password")
        or exit("Could not connect");

    if (mysql_create_db("my_db")) {
        print ("Database created successfully\n");
    } else {
        printf ("Error creating database: %s\n", mysql_error ());
    }
?>

For downwards compatibility mysql_createdb() can also be used. This is deprecated, however.

Note: The function mysql_create_db() is deprecated. It is preferable to use mysql_query() to issue a SQL CREATE DATABASE Statement instead.

mysql_data_seek

(PHP 3, PHP 4 )

mysql_data_seek -- Move internal result pointer

Description

bool mysql_data_seek ( resource result_identifier, int row_number)

Returns TRUE on success or FALSE on failure.

mysql_data_seek() moves the internal row pointer of the MySQL result associated with the specified result identifier to point to the specified row number. The next call to mysql_fetch_row() would return that row.

Row_number starts at 0. The row_number should be a value in the range from 0 to mysql_num_rows - 1.

Note: The function mysql_data_seek() can be used in conjunction only with mysql_query(), not with mysql_unbuffered_query().

Example 1. MySQL data seek example

<?php
    $link = mysql_pconnect("localhost", "mysql_user", "mysql_password")
        or die("Could not connect");

    mysql_select_db("samp_db")
        or exit("Could not select database");

    $query = "SELECT last_name, first_name FROM friends";
    $result = mysql_query($query)
        or die("Query failed");

    /* fetch rows in reverse order */
    for ($i = mysql_num_rows($result) - 1; $i >= 0; $i--) {
        if (!mysql_data_seek($result, $i)) {
            echo "Cannot seek to row $i\n";
            continue;
        }

        if(!($row = mysql_fetch_object($result)))
            continue;

        echo "$row->last_name $row->first_name<br />\n";
    }

    mysql_free_result($result);
?>

mysql_db_name

(PHP 3>= 3.0.6, PHP 4 )

mysql_db_name -- Get result data

Description

string mysql_db_name ( resource result, int row [, mixed field])

mysql_db_name() takes as its first parameter the result pointer from a call to mysql_list_dbs(). The row parameter is an index into the result set.

If an error occurs, FALSE is returned. Use mysql_errno() and mysql_error() to determine the nature of the error.

Example 1. mysql_db_name() example

<?php
    error_reporting(E_ALL);

    mysql_connect('dbhost', 'username', 'password');
    $db_list = mysql_list_dbs();

    $i = 0;
    $cnt = mysql_num_rows($db_list);
    while ($i < $cnt) {
        echo mysql_db_name($db_list, $i) . "\n";
        $i++;
    }
?>

For backward compatibility, mysql_dbname() is also accepted. This is deprecated, however.

mysql_db_query

(PHP 3, PHP 4 )

mysql_db_query -- Send a MySQL query

Description

resource mysql_db_query ( string database, string query [, resource link_identifier])

Returns a positive MySQL result resource to the query result, or FALSE on error. The function also returns TRUE/FALSE for INSERT/UPDATE/DELETE queries to indicate success/failure.

mysql_db_query() selects a database and executes a query on it. If the optional link identifier isn't specified, the function will try to find an open link to the MySQL server and if no such link is found it'll try to create one as if mysql_connect() was called with no arguments.

Be aware that this function does NOT switch back to the database you were connected before. In other words, you can't use this function to temporarily run a sql query on another database, you would have to manually switch back. Users are strongly encouraged to use the database.table syntax in their sql queries instead of this function.

Note: This function has been deprecated since PHP 4.0.6. Do not use this function. Use mysql_select_db() and mysql_query() instead.

mysql_drop_db

(PHP 3, PHP 4 )

mysql_drop_db -- Drop (delete) a MySQL database

Description

bool mysql_drop_db ( string database_name [, resource link_identifier])

Returns TRUE on success or FALSE on failure.

mysql_drop_db() attempts to drop (remove) an entire database from the server associated with the specified link identifier.

For downward compatibility mysql_dropdb() can also be used. This is deprecated, however.

Note: The function mysql_drop_db() is deprecated. It is preferable to use mysql_query() to issue a SQL DROP DATABASE statement instead.

mysql_errno

(PHP 3, PHP 4 )

mysql_errno -- Returns the numerical value of the error message from previous MySQL operation

Description

int mysql_errno ( [resource link_identifier])

Returns the error number from the last MySQL function, or 0 (zero) if no error occurred.

Errors coming back from the MySQL database backend no longer issue warnings. Instead, use mysql_errno() to retrieve the error code. Note that this function only returns the error code from the most recently executed MySQL function (not including mysql_error() and mysql_errno()), so if you want to use it, make sure you check the value before calling another MySQL function.
Example 1. mysql_errno Example
<?php mysql_connect("localhost", "mysql_user", "mysql_password"); mysql_select_db("nonexistentdb"); echo mysql_errno() . ": " . mysql_error(). "\n"; mysql_select_db("kossu"); mysql_query("SELECT * FROM nonexistenttable"); echo mysql_errno() . ": " . mysql_error() . "\n"; ?>
The above example would produce the following output:
1049: Unknown database 'nonexistentdb' 1146: Table 'kossu.nonexistenttable' doesn't exist

Note: If the optional argument is specified the given link is used to retrieve the error code. If not, the last opened link is used.

mysql_error

(PHP 3, PHP 4 )

mysql_error -- Returns the text of the error message from previous MySQL operation

Description

string mysql_error ( [resource link_identifier])

Returns the error text from the last MySQL function, or '' (the empty string) if no error occurred.

Errors coming back from the MySQL database backend no longer issue warnings. Instead, use mysql_error() to retrieve the error text. Note that this function only returns the error text from the most recently executed MySQL function (not including mysql_error() and mysql_errno()), so if you want to use it, make sure you check the value before calling another MySQL function.
Example 1. mysql_error Example
<?php mysql_connect("localhost", "mysql_user", "mysql_password"); mysql_select_db("nonexistentdb"); echo mysql_errno() . ": " . mysql_error(). "\n"; mysql_select_db("kossu"); mysql_query("SELECT * FROM nonexistenttable"); echo mysql_errno() . ": " . mysql_error() . "\n"; ?>
The above example would produce the following output:
1049: Unknown database 'nonexistentdb' 1146: Table 'kossu.nonexistenttable' doesn't exist

Note: If the optional argument is specified the given link is used to retrieve the error message. If not, the last opened link is used.

mysql_escape_string

(PHP 4 >= 4.0.3)

mysql_escape_string -- Escapes a string for use in a mysql_query.

Description

string mysql_escape_string ( string unescaped_string)

This function will escape the unescaped_string, so that it is safe to place it in a mysql_query().

Note: mysql_escape_string() does not escape % and _.
This function is identical to mysql_real_escape_string() except that mysql_real_escape_string() takes a connection handler and escapes the string according to the current character set. mysql_escape_string() does not take a connection argument and does not respect the current charset setting.

Example 1. mysql_escape_string() example

<?php
    $item = "Zak's Laptop";
    $escaped_item = mysql_escape_string($item);
    printf ("Escaped string: %s\n", $escaped_item);
?>

The above example would produce the following output:
Escaped string: Zak\'s Laptop

See also: mysql_real_escape_string(), addslashes(), and the magic_quotes_gpc directive.

mysql_fetch_array

(PHP 3, PHP 4 )

mysql_fetch_array -- Fetch a result row as an associative array, a numeric array, or both.

Description

array mysql_fetch_array ( resource result [, int result_type])

Returns an array that corresponds to the fetched row, or FALSE if there are no more rows.

mysql_fetch_array() is an extended version of mysql_fetch_row(). In addition to storing the data in the numeric indices of the result array, it also stores the data in associative indices, using the field names as keys.

If two or more columns of the result have the same field names, the last column will take precedence. To access the other column(s) of the same name, you must use the numeric index of the column or make an alias for the column. For aliased columns, you cannot access the contents with the original column name (by using 'field' in this example).
Example 1. Query with duplicate field names
select table1.field as foo table2.field as bar from table1, table2

An important thing to note is that using mysql_fetch_array() is not significantly slower than using mysql_fetch_row(), while it provides a significant added value.

The optional second argument result_type in mysql_fetch_array() is a constant and can take the following values: MYSQL_ASSOC, MYSQL_NUM, and MYSQL_BOTH. This feature was added in PHP 3.0.7. MYSQL_BOTH is the default for this argument.

By using MYSQL_BOTH, you'll get an array with both associative and number indices. Using MYSQL_ASSOC, you only get associative indices (as mysql_fetch_assoc() works), using MYSQL_NUM, you only get number indices (as mysql_fetch_row() works).

Example 2. mysql_fetch_array with MYSQL_NUM

<?php
    mysql_connect("localhost", "mysql_user", "mysql_password") or
        die("could not connect");
    mysql_select_db("mydb");

    $result = mysql_query("SELECT id, name FROM mytable");

    while ($row = mysql_fetch_array($result, MYSQL_NUM)) {
        printf ("ID: %s  Name: %s", $row[0], $row[1]);  
    }

    mysql_free_result($result);
?>

Example 3. mysql_fetch_array with MYSQL_ASSOC

<?php
    mysql_connect("localhost", "mysql_user", "mysql_password") or
        die("could not connect");
    mysql_select_db("mydb");

    $result = mysql_query("SELECT id, name FROM mytable");

    while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) {
        printf ("ID: %s  Name: %s", $row["id"], $row["name"]);
    }

    mysql_free_result($result);
?>

Example 4. mysql_fetch_array with MYSQL_BOTH

<?php
    mysql_connect("localhost", "mysql_user", "mysql_password") or
        die("could not connect");
    mysql_select_db("mydb");

    $result = mysql_query("SELECT id, name FROM mytable");

    while ($row = mysql_fetch_array($result, MYSQL_BOTH)) {
        printf ("ID: %s  Name: %s", $row[0], $row["name"]);
    }

    mysql_free_result($result);
?>

For further details, see also mysql_fetch_row() and mysql_fetch_assoc().

mysql_fetch_assoc

(PHP 4 >= 4.0.3)

mysql_fetch_assoc -- Fetch a result row as an associative array

Description

array mysql_fetch_assoc ( resource result)

Returns an associative array that corresponds to the fetched row, or FALSE if there are no more rows.

mysql_fetch_assoc() is equivalent to calling mysql_fetch_array() with MYSQL_ASSOC for the optional second parameter. It only returns an associative array. This is the way mysql_fetch_array() originally worked. If you need the numeric indices as well as the associative, use mysql_fetch_array().

If two or more columns of the result have the same field names, the last column will take precedence. To access the other column(s) of the same name, you either need to access the result with numeric indices by using mysql_fetch_row() or add alias names. See the example at the mysql_fetch_array() description about aliases.

An important thing to note is that using mysql_fetch_assoc() is not significantly slower than using mysql_fetch_row(), while it provides a significant added value.

Example 1. mysql_fetch_assoc()

<?php
    mysql_connect("localhost", "mysql_user", "mysql_password");
    mysql_select_db("mydb");
    $query = "select * from table";
    $result = mysql_query($query);
    while ($row = mysql_fetch_assoc($result)) {
        echo $row["user_id"];
        echo $row["fullname"];
    }
    mysql_free_result($result);
?>

For further details, see also mysql_fetch_row(), mysql_fetch_array() and mysql_query().

mysql_fetch_field

(PHP 3, PHP 4 )

mysql_fetch_field -- Get column information from a result and return as an object

Description

object mysql_fetch_field ( resource result [, int field_offset])

Returns an object containing field information.

mysql_fetch_field() can be used in order to obtain information about fields in a certain query result. If the field offset isn't specified, the next field that wasn't yet retrieved by mysql_fetch_field() is retrieved.

The properties of the object are:

name - column name
table - name of the table the column belongs to
max_length - maximum length of the column
not_null - 1 if the column cannot be NULL
primary_key - 1 if the column is a primary key
unique_key - 1 if the column is a unique key
multiple_key - 1 if the column is a non-unique key
numeric - 1 if the column is numeric
blob - 1 if the column is a BLOB
type - the type of the column
unsigned - 1 if the column is unsigned
zerofill - 1 if the column is zero-filled

Example 1. mysql_fetch_field()

<?php
mysql_connect('localhost:3306', $user, $password)
    or die ("Could not connect");
mysql_select_db("database");
$result = mysql_query("select * from table")
    or die("Query failed");
/* get column metadata */
$i = 0;
while ($i < mysql_num_fields($result)) {
    echo "Information for column $i:<br />\n";
    $meta = mysql_fetch_field($result);
    if (!$meta) {
        echo "No information available<br />\n";
    }
    echo "<pre>
blob:         $meta->blob
max_length:   $meta->max_length
multiple_key: $meta->multiple_key
name:         $meta->name
not_null:     $meta->not_null
numeric:      $meta->numeric
primary_key:  $meta->primary_key
table:        $meta->table
type:         $meta->type
unique_key:   $meta->unique_key
unsigned:     $meta->unsigned
zerofill:     $meta->zerofill
</pre>";
    $i++;
}
mysql_free_result($result);
?>

mysql_fetch_lengths

(PHP 3, PHP 4 )

mysql_fetch_lengths -- Get the length of each output in a result

Description

array mysql_fetch_lengths ( resource result)

Returns an array that corresponds to the lengths of each field in the last row fetched by mysql_fetch_row(), or FALSE on error.

mysql_fetch_lengths() stores the lengths of each result column in the last row returned by mysql_fetch_row(), mysql_fetch_array(), and mysql_fetch_object() in an array, starting at offset 0.

mysql_fetch_object

(PHP 3, PHP 4 )

mysql_fetch_object -- Fetch a result row as an object

Description

object mysql_fetch_object ( resource result)

int mysql_field_len ( resource result, int field_offset)

mysql_field_len() returns the length of the specified field.

For downward compatibility mysql_fieldlen() can also be used. This is deprecated, however.

mysql_field_name

(PHP 3, PHP 4 )

mysql_field_name -- Get the name of the specified field in a result

Description

string mysql_field_name ( resource result, int field_index)

mysql_field_name() returns the name of the specified field index. result must be a valid result identifier and field_index is the numerical offset of the field.

Note: field_index starts at 0.
e.g. The index of the third field would actually be 2, the index of the fourth field would be 3 and so on.

Example 1. mysql_field_name() example
/* The users table consists of three fields: * user_id * username * password. */ $link = mysql_connect('localhost', "mysql_user", "mysql_password"); mysql_select_db($dbname, $link) or die("Could not set $dbname"); $res = mysql_query("select * from users", $link); echo mysql_field_name($res, 0) . "\n"; echo mysql_field_name($res, 2);
The above example would produce the following output:
user_id password

For downwards compatibility mysql_fieldname() can also be used. This is deprecated, however.

mysql_field_seek

(PHP 3, PHP 4 )

mysql_field_seek -- Set result pointer to a specified field offset

bool mysql_free_result ( resource result)

mysql_free_result() will free all memory associated with the result identifier result.

mysql_free_result() only needs to be called if you are concerned about how much memory is being used for queries that return large result sets. All associated result memory is automatically freed at the end of the script's execution.

Returns TRUE on success or FALSE on failure.

For downward compatibility mysql_freeresult() can also be used. This is deprecated, however.

mysql_get_client_info

(PHP 4 >= 4.0.5)

mysql_get_client_info -- Get MySQL client info

Description

string mysql_get_client_info ( void)

mysql_get_client_info() returns a string that represents the client library version.

Example 1. mysql_get_client_info Example

<?php
    printf ("MySQL client info: %s\n", mysql_get_client_info());
?>

The above example would produce the following output:

MySQL client info: 3.23.39

mysql_get_host_info

(PHP 4 >= 4.0.5)

mysql_get_host_info -- Get MySQL host info

Description

string mysql_get_host_info ( [resource link_identifier])

mysql_get_host_info() returns a string describing the type of connection in use for the connection link_identifier, including the server host name. If link_identifier is omitted, the last opened connection will be used.

Example 1. mysql_get_host_info Example

<?php
    mysql_connect("localhost", "mysql_user", "mysql_password") or
        die("could not connect");
    printf ("MySQL host info: %s\n", mysql_get_host_info());
?>

The above example would produce the following output:

MySQL host info: Localhost via UNIX socket

mysql_get_proto_info

(PHP 4 >= 4.0.5)

mysql_get_proto_info -- Get MySQL protocol info

Description

int mysql_get_proto_info ( [resource link_identifier])

mysql_get_proto_info() returns the protocol version used by connection link_identifier. If link_identifier is omitted, the last opened connection will be used.

Example 1. mysql_get_proto_info Example

<?php
    mysql_connect("localhost", "mysql_user", "mysql_password") or
        die("could not connect");
    printf ("MySQL protocol version: %s\n", mysql_get_proto_info());
?>

The above example would produce the following output:

MySQL protocol version : 10

mysql_get_server_info

(PHP 4 >= 4.0.5)

mysql_get_server_info -- Get MySQL server info

Description

string mysql_get_server_info ( [resource link_identifier])

mysql_get_server_info() returns the server version used by connection link_identifier. If link_identifier is omitted, the last opened connection will be used.

Example 1. mysql_get_server_info Example

<?php
    mysql_connect("localhost", "mysql_user", "mysql_password") or
        die("could not connect");
    printf ("MySQL server version: %s\n", mysql_get_server_info());
?>

The above example would produce the following output:

MySQL server version: 4.0.1-alpha

mysql_info

(PHP 4 CVS only)

mysql_info -- Get information about the most recent query

Description

string mysql_info ( [resource link_identifier])

mysql_info() returns detailed information about the last query using the given link_identifier. If link_identifier isn't specified, the last opened link is assumed.

mysql_info() returns a string for all statements listed below. For all other FALSE. The string format depends on the given statement.
Example 1. Relevant MySQL Statements
INSERT INTO ... SELECT ... String format: Records: 23 Duplicates: 0 Warnings: 0 INSERT INTO ... VALUES (...),(...),(...)... String format: Records: 37 Duplicates: 0 Warnings: 0 LOAD DATA INFILE ... String format: Records: 42 Deleted: 0 Skipped: 0 Warnings: 0 ALTER TABLE String format: Records: 60 Duplicates: 0 Warnings: 0 UPDATE String format: Rows matched: 65 Changed: 65 Warnings: 0
The numbers are only for illustrating purpose; their values will correspond to the query.

Note: mysql_info() returns a non-FALSE value for the INSERT ... VALUES statement only if multiple value lists are specified in the statement.

mysql_insert_id

(PHP 3, PHP 4 )

mysql_insert_id -- Get the ID generated from the previous INSERT operation

Description

int mysql_insert_id ( [resource link_identifier])

mysql_insert_id() returns the ID generated for an AUTO_INCREMENT column by the previous INSERT query using the given link_identifier. If link_identifier isn't specified, the last opened link is assumed.

mysql_insert_id() returns 0 if the previous query does not generate an AUTO_INCREMENT value. If you need to save the value for later, be sure to call mysql_insert_id() immediately after the query that generates the value.

Note: The value of the MySQL SQL function LAST_INSERT_ID() always contains the most recently generated AUTO_INCREMENT value, and is not reset between queries.

Warning

mysql_insert_id() converts the return type of the native MySQL C API function mysql_insert_id() to a type of long (named int in PHP). If your AUTO_INCREMENT column has a column type of BIGINT, the value returned by mysql_insert_id() will be incorrect. Instead, use the internal MySQL SQL function LAST_INSERT_ID() in an SQL query.

Example 1. mysql_insert_id Example

<?php
    mysql_connect("localhost", "mysql_user", "mysql_password") or
        die("could not connect");
    mysql_select_db("mydb");

    mysql_query("INSERT INTO mytable (product) values ('kossu')");
    printf ("Last inserted record has id %d\n", mysql_insert_id());
?>

mysql_list_dbs

(PHP 3, PHP 4 )

mysql_list_dbs -- List databases available on a MySQL server

Description

resource mysql_list_dbs ( [resource link_identifier])

mysql_list_dbs() will return a result pointer containing the databases available from the current mysql daemon. Use the mysql_tablename() function to traverse this result pointer, or any function for result tables.

Example 1. mysql_list_dbs() example
<?php $link = mysql_connect('localhost', 'mysql_user', 'mysql_password'); $db_list = mysql_list_dbs($link); while ($row = mysql_fetch_object($db_list)) { echo $row->Database . "\n"; } ?>
The above example would produce the following output:
database1 database2 database3 ...

Note: The above code would just as easily work with mysql_fetch_row() or other similar functions.

For downward compatibility mysql_listdbs() can also be used. This is deprecated however.

mysql_list_fields

(PHP 3, PHP 4 )

mysql_list_fields -- List MySQL result fields

Description

resource mysql_list_fields ( string database_name, string table_name [, resource link_identifier])

mysql_list_fields() retrieves information about the given table name. Arguments are the database name and the table name. A result pointer is returned which can be used with mysql_field_flags(), mysql_field_len(), mysql_field_name(), and mysql_field_type().

Example 1. mysql_list_fields() example
<?php $link = mysql_connect('localhost', 'mysql_user', 'mysql_password'); $fields = mysql_list_fields("database1", "table1", $link); $columns = mysql_num_fields($fields); for ($i = 0; $i < $columns; $i++) { echo mysql_field_name($fields, $i) . "\n"; }
The above example would produce the following output:
field1 field2 field3 ...

For downward compatibility mysql_listfields() can also be used. This is deprecated however.

mysql_list_processes

(PHP 4 CVS only)

mysql_list_processes -- List MySQL processes

Description

resource mysql_list_processes ( [resource link_identifier])

mysql_list_processes() returns a result pointer describing the current server threads.

Example 1. mysql_list_processes() example
<?php $link = mysql_connect('localhost', 'mysql_user', 'mysql_password'); $result = mysql_list_processes($link); while ($row = mysql_fetch_row($result)){ printf("%s %s %s %s %s\n", $row["Id"], $row["Host"], $row["db"], $row["Command"], $row["Time"]); } mysql_free_result ($result); ?>
The above example would produce the following output:
1 localhost test Processlist 0 4 localhost mysql sleep 5

mysql_list_tables

(PHP 3, PHP 4 )

mysql_list_tables -- List tables in a MySQL database

Description

resource mysql_list_tables ( string database [, resource link_identifier])

mysql_list_tables() takes a database name and returns a result pointer much like the mysql_query() function. You can use the mysql_tablename() function to extract the actual table names from the result pointer, or any other result table function such as mysql_fetch_assoc().

The database parameter is the name of the database to retrieve the list of tables from. Upon failure, mysql_list_tables() returns FALSE.

For downward compatibility, the function alias named mysql_listtables() can be used. This is deprecated however and is not recommended.

Example 1. mysql_list_tables Example

<?php
    $dbname = 'mysql_dbname';

    if (!mysql_connect('mysql_host', 'mysql_user', 'mysql_password')) {
        print 'Could not connect to mysql';
        exit;
    }

    $result = mysql_list_tables($dbname);
    
    if (!$result) {
        print "DB Error, could not list tables\n";
        print 'MySQL Error: ' . mysql_error();
        exit;
    }
    
    while ($row = mysql_fetch_row($result)) {
        print "Table: $row[0]\n";
    }

    mysql_free_result($result);
?>

mysql_num_fields

(PHP 3, PHP 4 )

mysql_num_fields -- Get number of fields in result

Description

int mysql_num_fields ( resource result)

mysql_num_fields() returns the number of fields in a result set.

For downward compatibility mysql_numfields() can also be used. This is deprecated however.

mysql_num_rows

(PHP 3, PHP 4 )

mysql_num_rows -- Get number of rows in result

Description

int mysql_num_rows ( resource result)

mysql_num_rows() returns the number of rows in a result set. This command is only valid for SELECT statements. To retrieve the number of rows affected by a INSERT, UPDATE or DELETE query, use mysql_affected_rows().
Example 1. mysql_num_rows() example
<?php $link = mysql_connect("localhost", "mysql_user", "mysql_password"); mysql_select_db("database", $link); $result = mysql_query("SELECT * FROM table1", $link); $num_rows = mysql_num_rows($result); echo "$num_rows Rows\n"; ?>

Note: If you use mysql_unbuffered_query(), mysql_num_rows() will not return the correct value until all the rows in the result set have been retrieved.

For downward compatibility mysql_numrows() can also be used. This is deprecated however.

mysql_pconnect

(PHP 3, PHP 4 )

mysql_pconnect -- Open a persistent connection to a MySQL server

Description

resource mysql_pconnect ( [string server [, string username [, string password [, int client_flags]]]])

Returns a positive MySQL persistent link identifier on success, or FALSE on error.

mysql_pconnect() establishes a connection to a MySQL server. The following defaults are assumed for missing optional parameters: server = 'localhost:3306', username = name of the user that owns the server process and password = empty password. The client_flags parameter can be a combination of the constants MYSQL_CLIENT_SSL, MYSQL_CLIENT_COMPRESS, MYSQL_CLIENT_IGNORE_SPACE or MYSQL_CLIENT_INTERACTIVE.

The server parameter can also include a port number. eg. "hostname:port" or a path to a socket eg. ":/path/to/socket" for the localhost.

Note: Support for ":port" was added in 3.0B4.
Support for the ":/path/to/socket" was added in 3.0.10.

mysql_pconnect() acts very much like mysql_connect() with two major differences.

Second, the connection to the SQL server will not be closed when the execution of the script ends. Instead, the link will remain open for future use (mysql_close() will not close links established by mysql_pconnect()).

The optional client_flags parameter became available in PHP 4.3.0.

This type of link is therefore called 'persistent'.

Note: Note, that these kind of links only work if you are using a module version of PHP. See the Persistent Database Connections section for more information.

Warning

Using persistent connections can require a bit of tuning of your Apache and MySQL configurations to ensure that you do not exceed the number of connections allowed by MySQL.

mysql_ping

(PHP 4 CVS only)

mysql_ping -- Ping a server connection or reconnect if there is no connection

Description

bool mysql_ping ( [resource link_identifier])

mysql_ping() checks whether or not the connection to the server is working. If it has gone down, an automatic reconnection is attempted. This function can be used by scripts that remain idle for a long while, to check whether or not the server has closed the connection and reconnect if necessary. mysql_ping() returns TRUE if the connection to the server is working, otherwise FALSE.

mysql_query

(PHP 3, PHP 4 )

mysql_query -- Send a MySQL query

Description

resource mysql_query ( string query [, resource link_identifier [, int result_mode]])

mysql_query() sends a query to the currently active database on the server that's associated with the specified link identifier. If link_identifier isn't specified, the last opened link is assumed. If no link is open, the function tries to establish a link as if mysql_connect() was called with no arguments, and use it.

The optional result_mode parameter can be MYSQL_USE_RESULT and MYSQL_STORE_RESULT. It defaults to MYSQL_STORE_RESULT, so the result is buffered. See also mysql_unbuffered_query() for the counterpart of this behaviour.

Note: The query string should not end with a semicolon.

Only for SELECT,SHOW,EXPLAIN or DESCRIBE statements mysql_query() returns a resource identifier or FALSE if the query was not executed correctly. For other type of SQL statements, mysql_query() returns TRUE on success and FALSE on error. A non-FALSE return value means that the query was legal and could be executed by the server. It does not indicate anything about the number of rows affected or returned. It is perfectly possible for a query to succeed but affect no rows or return no rows.

The following query is syntactically invalid, so mysql_query() fails and returns FALSE:
Example 1. mysql_query()
<php $result = mysql_query("SELECT * WHERE 1=1") or die("Invalid query"); ?>

The following query is semantically invalid if my_col is not a column in the table my_tbl, so mysql_query() fails and returns FALSE:
Example 2. mysql_query()
<?php $result = mysql_query("SELECT my_col FROM my_tbl") or die ("Invalid query"); ?>

mysql_query() will also fail and return FALSE if you don't have permission to access the table(s) referenced by the query.

Assuming the query succeeds, you can call mysql_num_rows() to find out how many rows were returned for a SELECT statment or mysql_affected_rows() to find out how many rows were affected by a DELETE, INSERT, REPLACE, or UPDATE statement.

Only for SELECT,SHOW,DESCRIBE or EXPLAIN statements, mysql_query() returns a new result identifier that you can pass to mysql_fetch_array() and other functions dealing with result tables. When you are done with the result set, you can free the resources associated with it by calling mysql_free_result(). Although, the memory will automatically be freed at the end of the script's execution.

mysql_real_escape_string

(PHP 4 CVS only)

mysql_real_escape_string -- Escapes special characters in a string for use in a SQL statement, taking into account the current charset of the connection.

Description

string mysql_real_escape_string ( string unescaped_string [, resource link_identifier])

This function will escape special characters in the unescaped_string, taking into account the current charset of the connection so that it is safe to place it in a mysql_query().

Note: mysql_real_escape_string() does not escape % and _.

Example 1. mysql_real_escape_string() example

<?php
$link = mysql_connect('localhost', 'mysql_user', 'mysql_password');
$item = "Zak's and Derick's Laptop";
$escaped_item = mysql_real_escape_string($item);
printf ("Escaped string: %s\n", $escaped_item);
?>

mysql_tablename

resource mysql_unbuffered_query ( string query [, resource link_identifier [, int result_mode]])

mysql_unbuffered_query() sends a SQL query query to MySQL, without fetching and buffering the result rows automatically, as mysql_query() does. On the one hand, this saves a considerable amount of memory with SQL queries that produce large result sets. On the other hand, you can start working on the result set immediately after the first row has been retrieved: you don't have to wait until the complete SQL query has been performed. When using multiple DB-connects, you have to specify the optional parameter link_identifier.

The optional result_mode parameter can be MYSQL_USE_RESULT and MYSQL_STORE_RESULT. It defaults to MYSQL_USE_RESULT, so the result is not buffered. See also mysql_query() for the counterpart of this behaviour.

Note: The benefits of mysql_unbuffered_query() come at a cost: You cannot use mysql_num_rows() on a result set returned from mysql_unbuffered_query(). You also have to fetch all result rows from an unbuffered SQL query, before you can send a new SQL query to MySQL.

LXIV. Mohawk Software session handler functions

Introduction

msession is an interface to a high speed session daemon which can run either locally or remotely. It is designed to provide consistent session management for a PHP web farm. More Information about msession and the session server software itself can be found at http://www.mohawksoft.com/phoenix/.

Requirements

Installation

Runtime Configuration

Resource Types

Predefined Constants

Table of Contents
msession_connect -- Connect to msession server
msession_count -- Get session count
msession_create -- Create a session
msession_destroy -- Destroy a session
msession_disconnect -- Close connection to msession server
msession_find -- Find value
msession_get_array -- Get array of ... ?
msession_get -- Get value from session
msession_getdata -- Get data ... ?
msession_inc -- Increment value in session
msession_list -- List ... ?
msession_listvar -- List sessions with variable
msession_lock -- Lock a session
msession_plugin -- Call an escape function within the msession personality plugin
msession_randstr -- Get random string
msession_set_array -- Set array of ...
msession_set -- Set value in session
msession_setdata -- Set data ... ?
msession_timeout -- Set/get session timeout
msession_uniq -- Get uniq id
msession_unlock -- Unlock a session

LXV. muscat functions

Introduction

Warning

Table of Contents
muscat_close -- Shuts down the muscat session and releases any memory back to PHP.
muscat_get -- Gets a line back from the core muscat API.
muscat_give -- Sends string to the core muscat API
muscat_setup_net -- Creates a new muscat session and returns the handle.
muscat_setup -- Creates a new muscat session and returns the handle.

(4.0.5 - 4.2.3 only)

muscat_setup_net -- Creates a new muscat session and returns the handle.

Description

resource muscat_setup_net ( string muscat_host, int port)

Warning

This function is currently not documented; only the argument list is available.

muscat_host is the hostname to connect to port is the port number to connect to - actually takes exactly the same args as fsockopen

muscat_setup

(4.0.5 - 4.2.3 only)

muscat_setup -- Creates a new muscat session and returns the handle.

Description

resource muscat_setup ( int size [, string muscat_dir])

Warning

This function is currently not documented; only the argument list is available.

Size is the ammount of memory in bytes to allocate for muscat muscat_dir is the muscat installation dir e.g. "/usr/local/empower", it defaults to the compile time muscat directory

LXVI. Network Functions

Introduction

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Network Configuration Options

Name	Default	Changeable
define_syslog_variables	"0"	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Here is a short explanation of the configuration directives.

define_syslog_variables boolean: Whether or not to define the various syslog variables (e.g. $LOG_PID, $LOG_CRON, etc.). Turning it off is a good idea performance-wise. At runtime, you can define these variables by calling define_syslog_variables().

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are always available as part of the PHP core.

Table 2. openlog() Options

Constant	Description
LOG_CONS	if there is an error while sending data to the system logger, write directly to the system console
LOG_NDELAY	open the connection to the logger immediately
LOG_ODELAY	(default) delay opening the connection until the first message is logged
LOG_PERROR	print log message also to standard error
LOG_PID	include PID with each message

Table 3. syslog() Priorities (in descending order)

Constant	Description
LOG_EMERG	system is unusable
LOG_ALERT	action must be taken immediately
LOG_CRIT	critical conditions
LOG_ERR	error conditions
LOG_WARNING	warning conditions
LOG_NOTICE	normal, but significant, condition
LOG_INFO	informational message
LOG_DEBUG	debug-level message

Table of Contents
checkdnsrr -- Check DNS records corresponding to a given Internet host name or IP address
closelog -- Close connection to system logger
debugger_off -- Disable internal PHP debugger
debugger_on -- Enable internal PHP debugger
define_syslog_variables -- Initializes all syslog related constants
fsockopen -- Open Internet or Unix domain socket connection
gethostbyaddr -- Get the Internet host name corresponding to a given IP address
gethostbyname -- Get the IP address corresponding to a given Internet host name
gethostbynamel -- Get a list of IP addresses corresponding to a given Internet host name
getmxrr -- Get MX records corresponding to a given Internet host name
getprotobyname -- Get protocol number associated with protocol name
getprotobynumber -- Get protocol name associated with protocol number
getservbyname -- Get port number associated with an Internet service and protocol
getservbyport -- Get Internet service which corresponds to port and protocol
ip2long -- Converts a string containing an (IPv4) Internet Protocol dotted address into a proper address.
long2ip -- Converts an (IPv4) Internet network address into a string in Internet standard dotted format
openlog -- Open connection to system logger
pfsockopen -- Open persistent Internet or Unix domain socket connection
socket_get_status -- Alias of stream_get_meta_data().
socket_set_blocking -- Alias for stream_set_blocking()
socket_set_timeout -- Alias for stream_set_timeout()
syslog -- Generate a system log message

checkdnsrr

(PHP 3, PHP 4 )

checkdnsrr -- Check DNS records corresponding to a given Internet host name or IP address

Description

int checkdnsrr ( string host [, string type])

Searches DNS for records of type type corresponding to host. Returns TRUE if any records are found; returns FALSE if no records were found or if an error occurred.

type may be any one of: A, MX, NS, SOA, PTR, CNAME, or ANY. The default is MX.

Host may either be the IP address in dotted-quad notation or the host name.

Note: This function is not implemented on Windows platforms.

Initializes all constants used in the syslog functions.

See also openlog(), syslog() and closelog().

fsockopen

(PHP 3, PHP 4 )

fsockopen -- Open Internet or Unix domain socket connection

Description

int fsockopen ( string hostname, int port [, int errno [, string errstr [, float timeout]]])

Initiates a stream connection in the Internet (AF_INET, using TCP or UDP) or Unix (AF_UNIX) domain. For the Internet domain, it will open a TCP socket connection to hostname on port port. hostname may in this case be either a fully qualified domain name or an IP address. For UDP connections, you need to explicitly specify the protocol by prefixing hostname with 'udp://'. For the Unix domain, hostname will be used as the path to the socket, port must be set to 0 in this case. The optional timeout can be used to set a timeout in seconds for the connect system call.

Note: If you need to set a timeout for reading/writing data over the socket, use socket_set_timeout(), as the timeout parameter to fsockopen() only applies while connecting the socket.

As of PHP 4.3.0, if you have compiled in OpenSSL support, you may prefix the hostname with either 'ssl://' or 'tls://' to use an SSL or TLS client connection over TCP/IP to connect to the remote host.

fsockopen() returns a file pointer which may be used together with the other file functions (such as fgets(), fgetss(), fputs(), fclose(), and feof()).

If the call fails, it will return FALSE and if the optional errno and errstr arguments are present they will be set to indicate the actual system level error that occurred in the system-level connect() call. If the value returned in errno is 0 and the function returned FALSE, it is an indication that the error occurred before the connect() call. This is most likely due to a problem initializing the socket. Note that the errno and errstr arguments will always be passed by reference.

Depending on the environment, the Unix domain or the optional connect timeout may not be available.

The socket will by default be opened in blocking mode. You can switch it to non-blocking mode by using socket_set_blocking().
Example 1. fsockopen() Example
<?php $fp = fsockopen ("www.example.com", 80, $errno, $errstr, 30); if (!$fp) { echo "$errstr ($errno)<br>\n"; } else { fputs ($fp, "GET / HTTP/1.0\r\nHost: www.example.com\r\n\r\n"); while (!feof($fp)) { echo fgets ($fp,128); } fclose ($fp); } ?>
The example below shows how to retrieve the day and time from the UDP service "daytime" (port 13) in your own machine.
Example 2. Using UDP connection
<?php $fp = fsockopen("udp://127.0.0.1", 13, $errno, $errstr); if (!$fp) { echo "ERROR: $errno - $errstr<br>\n"; } else { fwrite($fp,"\n"); echo fread($fp, 26); fclose($fp); } ?>

Warning

UDP sockets will sometimes appear to have opened without an error, even if the remote host is unreachable. The error will only become apparent when you read or write data to/from the socket. The reason for this is because UDP is a "connectionless" protocol, which means that the operating system does not try to establish a link for the socket until it actually needs to send or receive data.

Note: The timeout parameter was introduced in PHP 3.0.9 and UDP support was added in PHP 4.

Returns a list of IP addresses to which the Internet host specified by hostname resolves.

See also gethostbyname(), gethostbyaddr(), checkdnsrr(), getmxrr(), and the named(8) manual page.

getmxrr

(PHP 3, PHP 4 )

getmxrr -- Get MX records corresponding to a given Internet host name

Description

int getmxrr ( string hostname, array mxhosts [, array weight])

Searches DNS for MX records corresponding to hostname. Returns TRUE if any records are found; returns FALSE if no records were found or if an error occurred.

A list of the MX records found is placed into the array mxhosts. If the weight array is given, it will be filled with the weight information gathered.

Note: This function is not implemented on Windows platforms.

The function ip2long() generates an IPv4 Internet network address from its Internet standard format (dotted string) representation.
Example 1. ip2long() Example
<?php $ip = gethostbyname("www.example.com"); $out = "The following URLs are equivalent:<br>\n"; $out .= "http://www.example.com/, http://".$ip."/, and http://".sprintf("%u",ip2long($ip))."/<br>\n"; echo $out; ?>

Note: Because PHP's integer type is signed, and many IP addresses will result in negative integers, you need to use the "%u" formatter of sprintf() or printf() to get the string representation of the unsigned IP address.

This second example shows how to print a converted address with the printf() function :

Example 2. Displaying an IP address

<?php
$ip = gethostbyname("www.example.com");
printf("%u\n", ip2long($ip));
echo $out;
?>

long2ip

(PHP 4 )

long2ip -- Converts an (IPv4) Internet network address into a string in Internet standard dotted format

Description

string long2ip ( int proper_address)

The function long2ip() generates an Internet address in dotted format (i.e.: aaa.bbb.ccc.ddd) from the proper address representation.

openlog

(PHP 3, PHP 4 )

openlog -- Open connection to system logger

Description

int openlog ( string ident, int option, int facility)

openlog() opens a connection to the system logger for a program. The string ident is added to each message. Values for option and facility are given below. The option argument is used to indicate what loggin options will be used when generating a log message. The facility argument is used to specify what type of program is logging the message. This allows you to specify (in your machine's syslog configuration) how messages coming from different facilities will be handled. The use of openlog() is optional. It will automatically be called by syslog() if necessary, in which case ident will default to FALSE.

Table 1. openlog() Options

Constant	Description
LOG_CONS	if there is an error while sending data to the system logger, write directly to the system console
LOG_NDELAY	open the connection to the logger immediately
LOG_ODELAY	(default) delay opening the connection until the first message is logged
LOG_PERROR	print log message also to standard error
LOG_PID	include PID with each message

You can use one or more of this options. When using multiple options you need to OR them, i.e. to open the connection immediately, write to the console and include the PID in each message, you will use: LOG_CONS | LOG_NDELAY | LOG_PID

Table 2. openlog() Facilities

Constant	Description
LOG_AUTH	security/authorization messages (use LOG_AUTHPRIV instead in systems where that constant is defined)
LOG_AUTHPRIV	security/authorization messages (private)
LOG_CRON	clock daemon (cron and at)
LOG_DAEMON	other system daemons
LOG_KERN	kernel messages
LOG_LOCAL0 ... LOG_LOCAL7	reserved for local use
LOG_LPR	line printer subsystem
LOG_MAIL	mail subsystem
LOG_NEWS	USENET news subsystem
LOG_SYSLOG	messages generated internally by syslogd
LOG_USER	generic user-level messages
LOG_UUCP	UUCP subsystem

pfsockopen

(PHP 3>= 3.0.7, PHP 4 )

pfsockopen -- Open persistent Internet or Unix domain socket connection

Description

int pfsockopen ( string hostname, int port [, int errno [, string errstr [, int timeout]]])

This function behaves exactly as fsockopen() with the difference that the connection is not closed after the script finishes. It is the persistent version of fsockopen().

socket_get_status

socket_get_status -- Alias of stream_get_meta_data().

Description

This function is an alias of stream_get_meta_data().

socket_set_blocking

socket_set_blocking -- Alias for stream_set_blocking()

Description

This function is an alias for stream_set_blocking().

socket_set_timeout

socket_set_timeout -- Alias for stream_set_timeout()

Description

This is an alias for stream_set_timeout().

syslog

(PHP 3, PHP 4 )

syslog -- Generate a system log message

Description

int syslog ( int priority, string message)

syslog() generates a log message that will be distributed by the system logger. priority is a combination of the facility and the level, values for which are given in the next section. The remaining argument is the message to send, except that the two characters %m will be replaced by the error message string (strerror) corresponding to the present value of errno.

Table 1. syslog() Priorities (in descending order)

Constant	Description
LOG_EMERG	system is unusable
LOG_ALERT	action must be taken immediately
LOG_CRIT	critical conditions
LOG_ERR	error conditions
LOG_WARNING	warning conditions
LOG_NOTICE	normal, but significant, condition
LOG_INFO	informational message
LOG_DEBUG	debug-level message

Example 1. Using syslog()
<?php define_syslog_variables(); // open syslog, include the process ID and also send // the log to standard error, and use a user defined // logging mechanism openlog("myScripLog", LOG_PID | LOG_PERROR, LOG_LOCAL0); // some code if (authorized_client()) { // do something } else { // unauthorized client! // log the attempt $access = date("Y/m/d H:i:s"); syslog(LOG_WARNING,"Unauthorized client: $access $REMOTE_ADDR ($HTTP_USER_AGENT)"); } closelog(); ?>
For information on setting up a user defined log handler, see the syslog.conf(5) Unix manual page. More information on the syslog facilities and option can be found in the man pages for syslog(3) on Unix machines.

On Windows NT, the syslog service is emulated using the Event Log.

LXVII. Ncurses terminal screen control functions

Introduction

ncurses (new curses) is a free software emulation of curses in System V Rel 4.0 (and above). It uses terminfo format, supports pads, colors, multiple highlights, form characters and function key mapping.

Warning

Ncurses is available for the following platforms:

AIX
BeOS
Cygwin
Digital Unix (aka OSF1)
FreeBSD
GNU/Linux
HPUX
IRIX
OS/2
SCO OpenServer
Solaris
SunOS

Requirements

You need the ncurses libraries and headerfiles. Download the latest version from the ftp://ftp.gnu.org/pub/gnu/ncurses/ or from an other GNU-Mirror.

Installation

To get these functions to work, you have to compile the CGI version of PHP with --with-ncurses.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Ncurses configuration options

Name	Default	Changeable
ncurses.value	"42"	PHP_INI_ALL
ncurses.string	"foobar"	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

Error codes

On error ncurses functions return NCURSES_ERR.

Colors

Table 2. ncurses color constants

constant	meaning
NCURSES_COLOR_BLACK	no color (black)
NCURSES_COLOR_WHITE	white
NCURSES_COLOR_RED	red - supported when terminal is in color mode
NCURSES_COLOR_GREEN	green - supported when terminal is in color mod
NCURSES_COLOR_YELLOW	yellow - supported when terminal is in color mod
NCURSES_COLOR_BLUE	blue - supported when terminal is in color mod
NCURSES_COLOR_CYAN	cyan - supported when terminal is in color mod
NCURSES_COLOR_MAGENTA	magenta - supported when terminal is in color mod

Keys

Table 3. ncurses key constants

constant	meaning
NCURSES_KEY_F0 - NCURSES_KEY_F64	function keys F1 - F64
NCURSES_KEY_DOWN	down arrow
NCURSES_KEY_UP	up arrow
NCURSES_KEY_LEFT	left arrow
NCURSES_KEY_RIGHT	right arrow
NCURSES_KEY_HOME	home key (upward+left arrow)
NCURSES_KEY_BACKSPACE	backspace
NCURSES_KEY_DL	delete line
NCURSES_KEY_IL	insert line
NCURSES_KEY_DC	delete character
NCURSES_KEY_IC	insert char or enter insert mode
NCURSES_KEY_EIC	exit insert char mode
NCURSES_KEY_CLEAR	clear screen
NCURSES_KEY_EOS	clear to end of screen
NCURSES_KEY_EOL	clear to end of line
NCURSES_KEY_SF	scroll one line forward
NCURSES_KEY_SR	scroll one line backward
NCURSES_KEY_NPAGE	next page
NCURSES_KEY_PPAGE	previous page
NCURSES_KEY_STAB	set tab
NCURSES_KEY_CTAB	clear tab
NCURSES_KEY_CATAB	clear all tabs
NCURSES_KEY_SRESET	soft (partial) reset
NCURSES_KEY_RESET	reset or hard reset
NCURSES_KEY_PRINT	print
NCURSES_KEY_LL	lower left
NCURSES_KEY_A1	upper left of keypad
NCURSES_KEY_A3	upper right of keypad
NCURSES_KEY_B2	center of keypad
NCURSES_KEY_C1	lower left of keypad
NCURSES_KEY_C3	lower right of keypad
NCURSES_KEY_BTAB	back tab
NCURSES_KEY_BEG	beginning
NCURSES_KEY_CANCEL	cancel
NCURSES_KEY_CLOSE	close
NCURSES_KEY_COMMAND	cmd (command)
NCURSES_KEY_COPY	copy
NCURSES_KEY_CREATE	create
NCURSES_KEY_END	end
NCURSES_KEY_EXIT	exit
NCURSES_KEY_FIND	find
NCURSES_KEY_HELP	help
NCURSES_KEY_MARK	mark
NCURSES_KEY_MESSAGE	message
NCURSES_KEY_MOVE	move
NCURSES_KEY_NEXT	next
NCURSES_KEY_OPEN	open
NCURSES_KEY_OPTIONS	options
NCURSES_KEY_PREVIOUS	previous
NCURSES_KEY_REDO	redo
NCURSES_KEY_REFERENCE	ref (reference)
NCURSES_KEY_REFRESH	refresh
NCURSES_KEY_REPLACE	replace
NCURSES_KEY_RESTART	restart
NCURSES_KEY_RESUME	resume
NCURSES_KEY_SAVE	save
NCURSES_KEY_SBEG	shiftet beg (beginning)
NCURSES_KEY_SCANCEL	shifted cancel
NCURSES_KEY_SCOMMAND	shifted command
NCURSES_KEY_SCOPY	shifted copy
NCURSES_KEY_SCREATE	shifted create
NCURSES_KEY_SDC	shifted delete char
NCURSES_KEY_SDL	shifted delete line
NCURSES_KEY_SELECT	select
NCURSES_KEY_SEND	shifted end
NCURSES_KEY_SEOL	shifted end of line
NCURSES_KEY_SEXIT	shifted exit
NCURSES_KEY_SFIND	shifted find
NCURSES_KEY_SHELP	shifted help
NCURSES_KEY_SHOME	shifted home
NCURSES_KEY_SIC	shifted input
NCURSES_KEY_SLEFT	shifted left arrow
NCURSES_KEY_SMESSAGE	shifted message
NCURSES_KEY_SMOVE	shifted move
NCURSES_KEY_SNEXT	shifted next
NCURSES_KEY_SOPTIONS	shifted options
NCURSES_KEY_SPREVIOUS	shifted previous
NCURSES_KEY_SPRINT	shifted print
NCURSES_KEY_SREDO	shifted redo
NCURSES_KEY_SREPLACE	shifted replace
NCURSES_KEY_SRIGHT	shifted right arrow
NCURSES_KEY_SRSUME	shifted resume
NCURSES_KEY_SSAVE	shifted save
NCURSES_KEY_SSUSPEND	shifted suspend
NCURSES_KEY_UNDO	undo
NCURSES_KEY_MOUSE	mouse event has occured
NCURSES_KEY_MAX	maximum key value

Mouse

Table 4. mouse constants

Constant	meaning
NCURSES_BUTTON1_RELEASED - NCURSES_BUTTON4_RELEASED	button (1-4) released
NCURSES_BUTTON1_PRESSED - NCURSES_BUTTON4_PRESSED	button (1-4) pressed
NCURSES_BUTTON1_CLICKED - NCURSES_BUTTON4_CLICKED	button (1-4) clicked
NCURSES_BUTTON1_DOUBLE_CLICKED - NCURSES_BUTTON4_DOUBLE_CLICKED	button (1-4) double clicked
NCURSES_BUTTON1_TRIPLE_CLICKED - NCURSES_BUTTON4_TRIPLE_CLICKED	button (1-4) triple clicked
NCURSES_BUTTON_CTRL	ctrl pressed during click
NCURSES_BUTTON_SHIFT	shift pressed during click
NCURSES_BUTTON_ALT	alt pressed during click
NCURSES_ALL_MOUSE_EVENTS	report all mouse events
NCURSES_REPORT_MOUSE_POSITION	report mouse position

Table of Contents
ncurses_addch -- Add character at current position and advance cursor
ncurses_addchnstr -- Add attributed string with specified length at current position
ncurses_addchstr -- Add attributed string at current position
ncurses_addnstr -- Add string with specified length at current position
ncurses_addstr -- Output text at current position
ncurses_assume_default_colors -- Define default colors for color 0
ncurses_attroff -- Turn off the given attributes
ncurses_attron -- Turn on the given attributes
ncurses_attrset -- Set given attributes
ncurses_baudrate -- Returns baudrate of terminal
ncurses_beep -- Let the terminal beep
ncurses_bkgd -- Set background property for terminal screen
ncurses_bkgdset -- Control screen background
ncurses_border -- Draw a border around the screen using attributed characters
ncurses_can_change_color -- Check if we can change terminals colors
ncurses_cbreak -- Switch of input buffering
ncurses_clear -- Clear screen
ncurses_clrtobot -- Clear screen from current position to bottom
ncurses_clrtoeol -- Clear screen from current position to end of line
ncurses_color_set -- Set fore- and background color
ncurses_curs_set -- Set cursor state
ncurses_def_prog_mode -- Saves terminals (program) mode
ncurses_def_shell_mode -- Saves terminals (shell) mode
ncurses_define_key -- Define a keycode
ncurses_delay_output -- Delay output on terminal using padding characters
ncurses_delch -- Delete character at current position, move rest of line left
ncurses_deleteln -- Delete line at current position, move rest of screen up
ncurses_delwin -- Delete a ncurses window
ncurses_doupdate -- Write all prepared refreshes to terminal
ncurses_echo -- Activate keyboard input echo
ncurses_echochar -- Single character output including refresh
ncurses_end -- Stop using ncurses, clean up the screen
ncurses_erase -- Erase terminal screen
ncurses_erasechar -- Returns current erase character
ncurses_filter --
ncurses_flash -- Flash terminal screen (visual bell)
ncurses_flushinp -- Flush keyboard input buffer
ncurses_getch -- Read a character from keyboard
ncurses_getmouse -- Reads mouse event
ncurses_halfdelay -- Put terminal into halfdelay mode
ncurses_has_colors -- Check if terminal has colors
ncurses_has_ic -- Check for insert- and delete-capabilities
ncurses_has_il -- Check for line insert- and delete-capabilities
ncurses_has_key -- Check for presence of a function key on terminal keyboard
ncurses_hline -- Draw a horizontal line at current position using an attributed character and max. n characters long
ncurses_inch -- Get character and attribute at current position
ncurses_init_color -- Set new RGB value for color
ncurses_init_pair -- Allocate a color pair
ncurses_init -- Initialize ncurses
ncurses_insch -- Insert character moving rest of line including character at current position
ncurses_insdelln -- Insert lines before current line scrolling down (negative numbers delete and scroll up)
ncurses_insertln -- Insert a line, move rest of screen down
ncurses_insstr -- Insert string at current position, moving rest of line right
ncurses_instr -- Reads string from terminal screen
ncurses_isendwin -- Ncurses is in endwin mode, normal screen output may be performed
ncurses_keyok -- Enable or disable a keycode
ncurses_killchar -- Returns current line kill character
ncurses_longname -- Returns terminals description
ncurses_mouseinterval -- Set timeout for mouse button clicks
ncurses_mousemask -- Sets mouse options
ncurses_move -- Move output position
ncurses_mvaddch -- Move current position and add character
ncurses_mvaddchnstr -- Move position and add attrributed string with specified length
ncurses_mvaddchstr -- Move position and add attributed string
ncurses_mvaddnstr -- Move position and add string with specified length
ncurses_mvaddstr -- Move position and add string
ncurses_mvcur -- Move cursor immediately
ncurses_mvdelch -- Move position and delete character, shift rest of line left
ncurses_mvgetch -- Move position and get character at new position
ncurses_mvhline -- Set new position and draw a horizontal line using an attributed character and max. n characters long
ncurses_mvinch -- Move position and get attributed character at new position
ncurses_mvvline -- Set new position and draw a vertical line using an attributed character and max. n characters long
ncurses_mvwaddstr -- Add string at new position in window
ncurses_napms -- Sleep
ncurses_newwin -- Create a new window
ncurses_nl -- Translate newline and carriage return / line feed
ncurses_nocbreak -- Switch terminal to cooked mode
ncurses_noecho -- Switch off keyboard input echo
ncurses_nonl -- Do not translate newline and carriage return / line feed
ncurses_noqiflush -- Do not flush on signal characters
ncurses_noraw -- Switch terminal out of raw mode
ncurses_putp --
ncurses_qiflush -- Flush on signal characters
ncurses_raw -- Switch terminal into raw mode
ncurses_refresh -- Refresh screen
ncurses_resetty -- Restores saved terminal state
ncurses_savetty -- Saves terminal state
ncurses_scr_dump -- Dump screen content to file
ncurses_scr_init -- Initialize screen from file dump
ncurses_scr_restore -- Restore screen from file dump
ncurses_scr_set -- Inherit screen from file dump
ncurses_scrl -- Scroll window content up or down without changing current position
ncurses_slk_attr -- Returns current soft label key attribute
ncurses_slk_attroff --
ncurses_slk_attron --
ncurses_slk_attrset --
ncurses_slk_clear -- Clears soft labels from screen
ncurses_slk_color -- Sets color for soft label keys
ncurses_slk_init -- Initializes soft label key functions
ncurses_slk_noutrefresh -- Copies soft label keys to virtual screen
ncurses_slk_refresh -- Copies soft label keys to screen
ncurses_slk_restore -- Restores soft label keys
ncurses_slk_touch -- Fources output when ncurses_slk_noutrefresh is performed
ncurses_standend -- Stop using 'standout' attribute
ncurses_standout -- Start using 'standout' attribute
ncurses_start_color -- Start using colors
ncurses_termattrs -- Returns a logical OR of all attribute flags supported by terminal
ncurses_termname -- Returns terminals (short)-name
ncurses_timeout -- Set timeout for special key sequences
ncurses_typeahead -- Specify different filedescriptor for typeahead checking
ncurses_ungetch -- Put a character back into the input stream
ncurses_ungetmouse -- Pushes mouse event to queue
ncurses_use_default_colors -- Assign terminal default colors to color id -1
ncurses_use_env -- Control use of environment information about terminal size
ncurses_use_extended_names -- Control use of extended names in terminfo descriptions
ncurses_vidattr --
ncurses_vline -- Draw a vertical line at current position using an attributed character and max. n characters long
ncurses_wrefresh -- Refresh window on terminal screen

ncurses_cbreak() returns TRUE or NCURSES_ERR if any error occured.

ncurses_clear

(PHP 4 >= 4.1.0)

ncurses_clear -- Clear screen

Description

bool ncurses_clear ( void)

bool ncurses_def_shell_mode ( void)

bool ncurses_echo ( void)

bool ncurses_getmouse ( array mevent)

Warning

ncurses_getmouse() reads mouse event out of queue. Function ncurses_getmouse() will return ;FALSE if a mouse event is actually visible in the given window, otherwise it will return TRUE. Event options will be delivered in parameter mevent, which has to be an array, passed by reference (see example below). On success an associative array with following keys will be delivered:

"id" : Id to distinguish multiple devices
"x" : screen relative x-position in character cells
"y" : screen relative y-position in character cells
"z" : currently not supported
"mmask" : Mouse action

Warning

Function ncurses_mousemask() will set mouse events to be reported. By default no mouse events will be reported. The function ncurses_mousemask() will return a mask to indicated which of the in parameter newmask specified mouse events can be reported. On complete failure, it returns 0. In parameter oldmask, which is passed by reference ncurses_mousemask() returns the previous value of mouse event mask. Mouse events are represented bei NCURSES_KEY_MOUSE in the ncurses_wgetch() input stream. To read the event data and pop the event of of queue, call ncurses_getmouse().

As a side effect, setting a zero mousemask in newmask turns off the mouse pointer. Setting a non zero value turns mouse pointer on.

mouse mask options can be set with the following predefined constants:

NCURSES_BUTTON1_PRESSED
NCURSES_BUTTON1_RELEASED
NCURSES_BUTTON1_CLICKED
NCURSES_BUTTON1_DOUBLE_CLICKED
NCURSES_BUTTON1_TRIPLE_CLICKED
NCURSES_BUTTON2_PRESSED
NCURSES_BUTTON2_RELEASED
NCURSES_BUTTON2_CLICKED
NCURSES_BUTTON2_DOUBLE_CLICKED
NCURSES_BUTTON2_TRIPLE_CLICKED
NCURSES_BUTTON3_PRESSED
NCURSES_BUTTON3_RELEASED
NCURSES_BUTTON3_CLICKED
NCURSES_BUTTON3_DOUBLE_CLICKED
NCURSES_BUTTON3_TRIPLE_CLICKED
NCURSES_BUTTON4_PRESSED
NCURSES_BUTTON4_RELEASED
NCURSES_BUTTON4_CLICKED
NCURSES_BUTTON4_DOUBLE_CLICKED
NCURSES_BUTTON4_TRIPLE_CLICKED
NCURSES_BUTTON_SHIFT>
NCURSES_BUTTON_CTRL
NCURSES_BUTTON_ALT
NCURSES_ALL_MOUSE_EVENTS
NCURSES_REPORT_MOUSE_POSITION

Warning

ncurses_getmouse() pushes a KEY_MOUSE event onto the unput queue and associates with this event the given state sata and screen-relative character cell coordinates, specified in mevent. Event options will be specified in associative array mevent:

"id" : Id to distinguish multiple devices
"x" : screen relative x-position in character cells
"y" : screen relative y-position in character cells
"z" : currently not supported
"mmask" : Mouse action

undocumented

LXVIII. Lotus Notes functions

Introduction

Warning

Table of Contents
notes_body -- Open the message msg_number in the specified mailbox on the specified server (leave serv
notes_copy_db -- Create a note using form form_name
notes_create_db -- Create a Lotus Notes database
notes_create_note -- Create a note using form form_name
notes_drop_db -- Drop a Lotus Notes database
notes_find_note -- Returns a note id found in database_name. Specify the name of the note. Leaving type bla
notes_header_info -- Open the message msg_number in the specified mailbox on the specified server (leave serv
notes_list_msgs -- Returns the notes from a selected database_name
notes_mark_read -- Mark a note_id as read for the User user_name
notes_mark_unread -- Mark a note_id as unread for the User user_name
notes_nav_create -- Create a navigator name, in database_name
notes_search -- Find notes that match keywords in database_name
notes_unread -- Returns the unread note id's for the current User user_name
notes_version -- Get the version Lotus Notes

LXIX. Unified ODBC functions

Introduction

In addition to normal ODBC support, the Unified ODBC functions in PHP allow you to access several databases that have borrowed the semantics of the ODBC API to implement their own API. Instead of maintaining multiple database drivers that were all nearly identical, these drivers have been unified into a single set of ODBC functions.

The following databases are supported by the Unified ODBC functions: Adabas D, IBM DB2, iODBC, Solid, and Sybase SQL Anywhere.

Note: There is no ODBC involved when connecting to the above databases. The functions that you use to speak natively to them just happen to share the same names and syntax as the ODBC functions. The exception to this is iODBC. Building PHP with iODBC support enables you to use any ODBC-compliant drivers with your PHP applications. iODBC is maintained by OpenLink Software. More information on iODBC, as well as a HOWTO, is available at www.iodbc.org.

Requirements

To access any of the supported databases you need to have the required libraries installed.

Installation

Please see the Database installation options chapter for more information about configuring PHP with these databases.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Unified ODBC Configuration Options

Name	Default	Changeable
odbc.default_db *	NULL	PHP_INI_ALL
odbc.default_user *	NULL	PHP_INI_ALL
odbc.default_pw *	NULL	PHP_INI_ALL
odbc.allow_persistent	"1"	PHP_INI_SYSTEM
odbc.check_persistent	"1"	PHP_INI_SYSTEM
odbc.max_persistent	"-1"	PHP_INI_SYSTEM
odbc.max_links	"-1"	PHP_INI_SYSTEM
odbc.defaultlrl	"4096"	PHP_INI_ALL
odbc.defaultbinmode	"1"	PHP_INI_ALL

Note: Entries marked with * are not implemented yet.

For further details and definition of the PHP_INI_* constants see ini_set().

Here is a short explanation of the configuration directives.

odbc.default_db string: ODBC data source to use if none is specified in odbc_connect() or odbc_pconnect().
odbc.default_user string: User name to use if none is specified in odbc_connect() or odbc_pconnect().
odbc.default_pw string: Password to use if none is specified in odbc_connect() or odbc_pconnect().
odbc.allow_persistent boolean: Whether to allow persistent ODBC connections.
odbc.check_persistent boolean: Check that a connection is still valid before reuse.
odbc.max_persistent integer: The maximum number of persistent ODBC connections per process.
odbc.max_links integer: The maximum number of ODBC connections per process, including persistent connections.
odbc.defaultlrl integer: Handling of LONG fields. Specifies the number of bytes returned to variables.
odbc.defaultbinmode integer: Handling of binary data.

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

ODBC_TYPE (integer)
ODBC_BINMODE_PASSTHRU (integer)
ODBC_BINMODE_RETURN (integer)
ODBC_BINMODE_CONVERT (integer)
SQL_ODBC_CURSORS (integer)
SQL_CUR_USE_DRIVER (integer)
SQL_CUR_USE_IF_NEEDED (integer)
SQL_CUR_USE_ODBC (integer)
SQL_CONCURRENCY (integer)
SQL_CONCUR_READ_ONLY (integer)
SQL_CONCUR_LOCK (integer)
SQL_CONCUR_ROWVER (integer)
SQL_CONCUR_VALUES (integer)
SQL_CURSOR_TYPE (integer)
SQL_CURSOR_FORWARD_ONLY (integer)
SQL_CURSOR_KEYSET_DRIVEN (integer)
SQL_CURSOR_DYNAMIC (integer)
SQL_CURSOR_STATIC (integer)
SQL_KEYSET_SIZE (integer)
SQL_CHAR (integer)
SQL_VARCHAR (integer)
SQL_LONGVARCHAR (integer)
SQL_DECIMAL (integer)
SQL_NUMERIC (integer)
SQL_BIT (integer)
SQL_TINYINT (integer)
SQL_SMALLINT (integer)
SQL_INTEGER (integer)
SQL_BIGINT (integer)
SQL_REAL (integer)
SQL_FLOAT (integer)
SQL_DOUBLE (integer)
SQL_BINARY (integer)
SQL_VARBINARY (integer)
SQL_LONGVARBINARY (integer)
SQL_DATE (integer)
SQL_TIME (integer)
SQL_TIMESTAMP (integer)
SQL_TYPE_DATE (integer)
SQL_TYPE_TIME (integer)
SQL_TYPE_TIMESTAMP (integer)
SQL_BEST_ROWID (integer)
SQL_ROWVER (integer)
SQL_SCOPE_CURROW (integer)
SQL_SCOPE_TRANSACTION (integer)
SQL_SCOPE_SESSION (integer)
SQL_NO_NULLS (integer)
SQL_NULLABLE (integer)
SQL_INDEX_UNIQUE (integer)
SQL_INDEX_ALL (integer)
SQL_ENSURE (integer)
SQL_QUICK (integer)

Table of Contents
odbc_autocommit -- Toggle autocommit behaviour
odbc_binmode -- Handling of binary column data
odbc_close_all -- Close all ODBC connections
odbc_close -- Close an ODBC connection
odbc_columnprivileges -- Returns a result identifier that can be used to fetch a list of columns and associated privileges
odbc_columns -- Lists the column names in specified tables. Returns a result identifier containing the information.
odbc_commit -- Commit an ODBC transaction
odbc_connect -- Connect to a datasource
odbc_cursor -- Get cursorname
odbc_data_source -- Returns information about a current connection
odbc_do -- Synonym for odbc_exec()
odbc_error -- Get the last error code
odbc_errormsg -- Get the last error message
odbc_exec -- Prepare and execute a SQL statement
odbc_execute -- Execute a prepared statement
odbc_fetch_array -- Fetch a result row as an associative array
odbc_fetch_into -- Fetch one result row into array
odbc_fetch_object -- Fetch a result row as an object
odbc_fetch_row -- Fetch a row
odbc_field_len -- Get the length (precision) of a field
odbc_field_name -- Get the columnname
odbc_field_num -- Return column number
odbc_field_precision -- Synonym for odbc_field_len()
odbc_field_scale -- Get the scale of a field
odbc_field_type -- Datatype of a field
odbc_foreignkeys -- Returns a list of foreign keys in the specified table or a list of foreign keys in other tables that refer to the primary key in the specified table
odbc_free_result -- Free resources associated with a result
odbc_gettypeinfo -- Returns a result identifier containing information about data types supported by the data source.
odbc_longreadlen -- Handling of LONG columns
odbc_next_result -- Checks if multiple results are avaiable
odbc_num_fields -- Number of columns in a result
odbc_num_rows -- Number of rows in a result
odbc_pconnect -- Open a persistent database connection
odbc_prepare -- Prepares a statement for execution
odbc_primarykeys -- Returns a result identifier that can be used to fetch the column names that comprise the primary key for a table
odbc_procedurecolumns -- Retrieve information about parameters to procedures
odbc_procedures -- Get the list of procedures stored in a specific data source. Returns a result identifier containing the information.
odbc_result_all -- Print result as HTML table
odbc_result -- Get result data
odbc_rollback -- Rollback a transaction
odbc_setoption -- Adjust ODBC settings. Returns FALSE if an error occurs, otherwise TRUE.
odbc_specialcolumns -- Returns either the optimal set of columns that uniquely identifies a row in the table or columns that are automatically updated when any value in the row is updated by a transaction
odbc_statistics -- Retrieve statistics about a table
odbc_tableprivileges -- Lists tables and the privileges associated with each table
odbc_tables -- Get the list of table names stored in a specific data source. Returns a result identifier containing the information.

odbc_autocommit

(PHP 3>= 3.0.6, PHP 4 )

odbc_autocommit -- Toggle autocommit behaviour

Description

bool odbc_autocommit ( resource connection_id [, bool OnOff])

Without the OnOff parameter, this function returns auto-commit status for connection_id. TRUE is returned if auto-commit is on, FALSE if it is off or an error occurs.

If OnOff is TRUE, auto-commit is enabled, if it is FALSE auto-commit is disabled. Returns TRUE on success, FALSE on failure.

By default, auto-commit is on for a connection. Disabling auto-commit is equivalent with starting a transaction.

odbc_binmode

(PHP 3>= 3.0.6, PHP 4 )

odbc_binmode -- Handling of binary column data

Description

int odbc_binmode ( resource result_id, int mode)

(ODBC SQL types affected: BINARY, VARBINARY, LONGVARBINARY)

ODBC_BINMODE_PASSTHRU: Passthru BINARY data
ODBC_BINMODE_RETURN: Return as is
ODBC_BINMODE_CONVERT: Convert to char and return

When binary SQL data is converted to character C data, each byte (8 bits) of source data is represented as two ASCII characters. These characters are the ASCII character representation of the number in its hexadecimal form. For example, a binary 00000001 is converted to "01" and a binary 11111111 is converted to "FF".

Table 1. LONGVARBINARY handling

binmode	longreadlen	result
ODBC_BINMODE_PASSTHRU	0	passthru
ODBC_BINMODE_RETURN	0	passthru
ODBC_BINMODE_CONVERT	0	passthru
ODBC_BINMODE_PASSTHRU	0	passthru
ODBC_BINMODE_PASSTHRU	>0	passthru
ODBC_BINMODE_RETURN	>0	return as is
ODBC_BINMODE_CONVERT	>0	return as char

If odbc_fetch_into() is used, passthru means that an empty string is returned for these columns.

If result_id is 0, the settings apply as default for new results.

Note: Default for longreadlen is 4096 and binmode defaults to ODBC_BINMODE_RETURN. Handling of binary long columns is also affected by odbc_longreadlen()

odbc_close_all

(PHP 3>= 3.0.6, PHP 4 )

odbc_close_all -- Close all ODBC connections

Description

void odbc_close_all ( void)

odbc_close_all() will close down all connections to database server(s).

Note: This function will fail if there are open transactions on a connection. This connection will remain open in this case.

odbc_close

(PHP 3>= 3.0.6, PHP 4 )

odbc_close -- Close an ODBC connection

Description

void odbc_close ( resource connection_id)

odbc_close() will close down the connection to the database server associated with the given connection identifier.

Note: This function will fail if there are open transactions on this connection. The connection will remain open in this case.

odbc_columnprivileges

(PHP 4 )

odbc_columnprivileges -- Returns a result identifier that can be used to fetch a list of columns and associated privileges

Description

int odbc_columnprivileges ( resource connection_id [, string qualifier [, string owner [, string table_name [, string column_name]]]])

Lists columns and associated privileges for the given table. Returns an ODBC result identifier or FALSE on failure.

The result set has the following columns:

TABLE_QUALIFIER
TABLE_OWNER
TABLE_NAME
GRANTOR
GRANTEE
PRIVILEGE
IS_GRANTABLE

The result set is ordered by TABLE_QUALIFIER, TABLE_OWNER and TABLE_NAME.

The column_name argument accepts search patterns ('%' to match zero or more characters and '_' to match a single character).

odbc_columns

(PHP 4 )

odbc_columns -- Lists the column names in specified tables. Returns a result identifier containing the information.

Description

int odbc_columns ( resource connection_id [, string qualifier [, string schema [, string table_name [, string column_name]]]])

Lists all columns in the requested range. Returns an ODBC result identifier or FALSE on failure.

The result set has the following columns:

TABLE_QUALIFIER
TABLE_SCHEM
TABLE_NAME
COLUMN_NAME
DATA_TYPE
TYPE_NAME
PRECISION
LENGTH
SCALE
RADIX
NULLABLE
REMARKS

The result set is ordered by TABLE_QUALIFIER, TABLE_SCHEM and TABLE_NAME.

The schema, table_name and column_name arguments accept search patterns ('%' to match zero or more characters and '_' to match a single character).

See also odbc_columnprivileges() to retrieve associated privileges.

odbc_commit

(PHP 3>= 3.0.6, PHP 4 )

odbc_commit -- Commit an ODBC transaction

Description

bool odbc_commit ( resource connection_id)

Returns: TRUE on success, FALSE on failure. All pending transactions on connection_id are committed.

odbc_connect

(PHP 3>= 3.0.6, PHP 4 )

odbc_connect -- Connect to a datasource

Description

resource odbc_connect ( string dsn, string user, string password [, int cursor_type])

Returns an ODBC connection id or 0 (FALSE) on error.

The connection id returned by this functions is needed by other ODBC functions. You can have multiple connections open at once. The optional fourth parameter sets the type of cursor to be used for this connection. This parameter is not normally needed, but can be useful for working around problems with some ODBC drivers.

With some ODBC drivers, executing a complex stored procedure may fail with an error similar to: "Cannot open a cursor on a stored procedure that has anything other than a single select statement in it". Using SQL_CUR_USE_ODBC may avoid that error. Also, some drivers don't support the optional row_number parameter in odbc_fetch_row(). SQL_CUR_USE_ODBC might help in that case, too.

The following constants are defined for cursortype:

SQL_CUR_USE_IF_NEEDED
SQL_CUR_USE_ODBC
SQL_CUR_USE_DRIVER
SQL_CUR_DEFAULT

For persistent connections see odbc_pconnect().

odbc_cursor

(PHP 3>= 3.0.6, PHP 4 )

odbc_cursor -- Get cursorname

Description

string odbc_cursor ( resource result_id)

odbc_cursor will return a cursorname for the given result_id.

odbc_data_source

(PHP 4 CVS only)

odbc_data_source -- Returns information about a current connection

Description

resource odbc_data_source ( resource connection_id, constant fetch_type)

Returns FALSE on error, and an array upon success.

This function will return information about the active connection following the information from within the DSN. The connection_id is required to be a valid ODBC connection. The fetch_type can be one of two constant types: SQL_FETCH_FIRST, SQL_FETCH_NEXT. Use SQL_FETCH_FIRST the first time this function is called, thereafter use the SQL_FETCH_NEXT.

odbc_do

(PHP 3>= 3.0.6, PHP 4 )

odbc_do -- Synonym for odbc_exec()

resource odbc_exec ( resource connection_id, string query_string)

Returns FALSE on error. Returns an ODBC result identifier if the SQL command was executed successfully.

odbc_exec() will send an SQL statement to the database server specified by connection_id. This parameter must be a valid identifier returned by odbc_connect() or odbc_pconnect().

See also: odbc_prepare() and odbc_execute() for multiple execution of SQL statements.

odbc_execute

(PHP 3>= 3.0.6, PHP 4 )

odbc_execute -- Execute a prepared statement

Description

resource odbc_execute ( resource result_id [, array parameters_array])

Executes a statement prepared with odbc_prepare(). Returns TRUE on successful execution; FALSE otherwise. The array parameters_array only needs to be given if you really have parameters in your statement.

Parameters in parameter_array will be substituted for placeholders in the prepared statement in order.

Any parameters in parameter_array which start and end with single quotes will be taken as the name of a file to read and send to the database server as the data for the appropriate placeholder.

Note: As of PHP 4.1.1, this file reading functionality has the following restrictions:
File reading is not subject to any safe mode or safe mode restrictions. This is fixed in PHP 4.2.0.
Remote files are not supported.
If you wish to store a string which actually begins and ends with single quotes, you must escape them or add a space or other non-single-quote character to the beginning or end of the parameter, which will prevent the parameter's being taken as a file name. If this is not an option, then you must use another mechanism to store the string, such as executing the query directly with odbc_exec()).

odbc_fetch_array

(PHP 4 >= 4.0.2)

odbc_fetch_array -- Fetch a result row as an associative array

Description

array odbc_fetch_array ( resource result [, int rownumber])

Warning

This function is currently not documented; only the argument list is available.

odbc_fetch_into

(PHP 3>= 3.0.6, PHP 4 )

odbc_fetch_into -- Fetch one result row into array

Description

bool odbc_fetch_into ( resource result_id [, int rownumber, array result_array])

resource odbc_fetch_into ( resource result_id, array result_array [, int rownumber])

Returns the number of columns in the result; FALSE on error. result_array must be passed by reference, but it can be of any type since it will be converted to type array. The array will contain the column values starting at array index 0.

As of PHP 4.0.5 the result_array does not need to be passed by reference any longer.

As of PHP 4.0.6 the rownumber cannot be passed as a constant, but rather as a variable.

As of PHP 4.2.0 the result_array and rownumber have been swapped. This allows the rownumber to be a constant again. This change will also be the last one to this function.

Example 1. odbc_fetch_into() pre 4.0.6 example
$rc = odbc_fetch_into($res_id, $my_array);
or
$rc = odbc_fetch_into($res_id, $row, $my_array); $rc = odbc_fetch_into($res_id, 1, $my_array);

Example 2. odbc_fetch_into() 4.0.6 example
$rc = odbc_fetch_into($res_id, $my_array);
or
$row = 1; $rc = odbc_fetch_into($res_id, $row, $my_array);

Example 3. odbc_fetch_into() 4.2.0 example
$rc = odbc_fetch_into($res_id, $my_array);
or
$rc = odbc_fetch_into($res_id,$my_array, 2);

odbc_fetch_object

(PHP 4 >= 4.0.2)

odbc_fetch_object -- Fetch a result row as an object

Description

object odbc_fetch_object ( resource result [, int rownumber])

Warning

This function is currently not documented; only the argument list is available.

odbc_fetch_row

(PHP 3>= 3.0.6, PHP 4 )

odbc_fetch_row -- Fetch a row

Description

bool odbc_fetch_row ( resource result_id [, int row_number])

If odbc_fetch_row() was succesful (there was a row), TRUE is returned. If there are no more rows, FALSE is returned.

odbc_fetch_row() fetches a row of the data that was returned by odbc_do() / odbc_exec(). After odbc_fetch_row() is called, the fields of that row can be accessed with odbc_result().

If row_number is not specified, odbc_fetch_row() will try to fetch the next row in the result set. Calls to odbc_fetch_row() with and without row_number can be mixed.

To step through the result more than once, you can call odbc_fetch_row() with row_number 1, and then continue doing odbc_fetch_row() without row_number to review the result. If a driver doesn't support fetching rows by number, the row_number parameter is ignored.

odbc_field_len

(PHP 3>= 3.0.6, PHP 4 )

odbc_field_len -- Get the length (precision) of a field

Description

int odbc_field_len ( resource result_id, int field_number)

odbc_field_len() will return the length of the field referecend by number in the given ODBC result identifier. Field numbering starts at 1.

See also: odbc_field_scale() to get the scale of a floating point number.

odbc_foreignkeys() retrieves information about foreign keys. Returns an ODBC result identifier or FALSE on failure.

The result set has the following columns:

PKTABLE_QUALIFIER
PKTABLE_OWNER
PKTABLE_NAME
PKCOLUMN_NAME
FKTABLE_QUALIFIER
FKTABLE_OWNER
FKTABLE_NAME
FKCOLUMN_NAME
KEY_SEQ
UPDATE_RULE
DELETE_RULE
FK_NAME
PK_NAME

If pk_table contains a table name, odbc_foreignkeys() returns a result set containing the primary key of the specified table and all of the foreign keys that refer to it.

If fk_table contains a table name, odbc_foreignkeys() returns a result set containing all of the foreign keys in the specified table and the primary keys (in other tables) to which they refer.

If both pk_table and fk_table contain table names, odbc_foreignkeys() returns the foreign keys in the table specified in fk_table that refer to the primary key of the table specified in pk_table. This should be one key at most.

odbc_free_result

(PHP 3>= 3.0.6, PHP 4 )

odbc_free_result -- Free resources associated with a result

Description

bool odbc_free_result ( resource result_id)

Always returns TRUE.

odbc_free_result() only needs to be called if you are worried about using too much memory while your script is running. All result memory will automatically be freed when the script is finished. But, if you are sure you are not going to need the result data anymore in a script, you may call odbc_free_result(), and the memory associated with result_id will be freed.

Note: If auto-commit is disabled (see odbc_autocommit()) and you call odbc_free_result() before commiting, all pending transactions are rolled back.

odbc_gettypeinfo

(PHP 4 )

odbc_gettypeinfo -- Returns a result identifier containing information about data types supported by the data source.

Description

int odbc_gettypeinfo ( resource connection_id [, int data_type])

Retrieves information about data types supported by the data source. Returns an ODBC result identifier or FALSE on failure. The optional argument data_type can be used to restrict the information to a single data type.

The result set has the following columns:

TYPE_NAME
DATA_TYPE
PRECISION
LITERAL_PREFIX
LITERAL_SUFFIX
CREATE_PARAMS
NULLABLE
CASE_SENSITIVE
SEARCHABLE
UNSIGNED_ATTRIBUTE
MONEY
AUTO_INCREMENT
LOCAL_TYPE_NAME
MINIMUM_SCALE
MAXIMUM_SCALE

odbc_num_rows

(PHP 3>= 3.0.6, PHP 4 )

odbc_num_rows -- Number of rows in a result

Description

int odbc_num_rows ( resource result_id)

odbc_num_rows() will return the number of rows in an ODBC result. This function will return -1 on error. For INSERT, UPDATE and DELETE statements odbc_num_rows() returns the number of rows affected. For a SELECT clause this can be the number of rows available.

Note: Using odbc_num_rows() to determine the number of rows available after a SELECT will return -1 with many drivers.

odbc_pconnect

(PHP 3>= 3.0.6, PHP 4 )

odbc_pconnect -- Open a persistent database connection

Description

int odbc_pconnect ( string dsn, string user, string password [, int cursor_type])

Returns an ODBC connection id or 0 (FALSE) on error. This function is much like odbc_connect(), except that the connection is not really closed when the script has finished. Future requests for a connection with the same dsn, user, password combination (via odbc_connect() and odbc_pconnect()) can reuse the persistent connection.

Note: Persistent connections have no effect if PHP is used as a CGI program.

For information about the optional cursor_type parameter see the odbc_connect() function. For more information on persistent connections, refer to the PHP FAQ.

odbc_prepare

(PHP 3>= 3.0.6, PHP 4 )

odbc_prepare -- Prepares a statement for execution

Description

resource odbc_prepare ( resource connection_id, string query_string)

Returns FALSE on error.

Returns an ODBC result identifier if the SQL command was prepared successfully. The result identifier can be used later to execute the statement with odbc_execute().

odbc_primarykeys

(PHP 4 )

odbc_primarykeys -- Returns a result identifier that can be used to fetch the column names that comprise the primary key for a table

Description

resource odbc_primarykeys ( resource connection_id, string qualifier, string owner, string table)

Returns the column names that comprise the primary key for a table. Returns an ODBC result identifier or FALSE on failure.

The result set has the following columns:

TABLE_QUALIFIER
TABLE_OWNER
TABLE_NAME
COLUMN_NAME
KEY_SEQ
PK_NAME

odbc_procedurecolumns

(PHP 4 )

odbc_procedurecolumns -- Retrieve information about parameters to procedures

Description

resource odbc_procedurecolumns ( resource connection_id [, string qualifier [, string owner [, string proc [, string column]]]])

Returns the list of input and output parameters, as well as the columns that make up the result set for the specified procedures. Returns an ODBC result identifier or FALSE on failure.

The result set has the following columns:

PROCEDURE_QUALIFIER
PROCEDURE_OWNER
PROCEDURE_NAME
COLUMN_NAME
COLUMN_TYPE
DATA_TYPE
TYPE_NAME
PRECISION
LENGTH
SCALE
RADIX
NULLABLE
REMARKS

The result set is ordered by PROCEDURE_QUALIFIER, PROCEDURE_OWNER, PROCEDURE_NAME and COLUMN_TYPE.

The owner, proc and column arguments accept search patterns ('%' to match zero or more characters and '_' to match a single character).

odbc_procedures

(PHP 4 )

odbc_procedures -- Get the list of procedures stored in a specific data source. Returns a result identifier containing the information.

Description

resource odbc_procedures ( resource connection_id [, string qualifier [, string owner [, string name]]])

Lists all procedures in the requested range. Returns an ODBC result identifier or FALSE on failure.

The result set has the following columns:

PROCEDURE_QUALIFIER
PROCEDURE_OWNER
PROCEDURE_NAME
NUM_INPUT_PARAMS
NUM_OUTPUT_PARAMS
NUM_RESULT_SETS
REMARKS
PROCEDURE_TYPE

Description

int odbc_rollback ( resource connection_id)

Rolls back all pending statements on connection_id. Returns TRUE on success, FALSE on failure.

odbc_setoption

(PHP 3>= 3.0.6, PHP 4 )

odbc_setoption -- Adjust ODBC settings. Returns FALSE if an error occurs, otherwise TRUE.

Description

int odbc_setoption ( resource id, int function, int option, int param)

This function allows fiddling with the ODBC options for a particular connection or query result. It was written to help find work arounds to problems in quirky ODBC drivers. You should probably only use this function if you are an ODBC programmer and understand the effects the various options will have. You will certainly need a good ODBC reference to explain all the different options and values that can be used. Different driver versions support different options.

Because the effects may vary depending on the ODBC driver, use of this function in scripts to be made publicly available is strongly discouraged. Also, some ODBC options are not available to this function because they must be set before the connection is established or the query is prepared. However, if on a particular job it can make PHP work so your boss doesn't tell you to use a commercial product, that's all that really matters.

id is a connection id or result id on which to change the settings.For SQLSetConnectOption(), this is a connection id. For SQLSetStmtOption(), this is a result id.

Function is the ODBC function to use. The value should be 1 for SQLSetConnectOption() and 2 for SQLSetStmtOption().

Parameter option is the option to set.

Parameter param is the value for the given option.
Example 1. ODBC Setoption Examples
// 1. Option 102 of SQLSetConnectOption() is SQL_AUTOCOMMIT. // Value 1 of SQL_AUTOCOMMIT is SQL_AUTOCOMMIT_ON. // This example has the same effect as // odbc_autocommit($conn, true); odbc_setoption ($conn, 1, 102, 1); // 2. Option 0 of SQLSetStmtOption() is SQL_QUERY_TIMEOUT. // This example sets the query to timeout after 30 seconds. $result = odbc_prepare ($conn, $sql); odbc_setoption ($result, 2, 0, 30); odbc_execute ($result);

odbc_specialcolumns

(PHP 4 )

odbc_specialcolumns -- Returns either the optimal set of columns that uniquely identifies a row in the table or columns that are automatically updated when any value in the row is updated by a transaction

Description

resource odbc_specialcolumns ( resource connection_id, int type, string qualifier, string owner, string table, int scope, int nullable)

When the type argument is SQL_BEST_ROWID, odbc_specialcolumns() returns the column or columns that uniquely identify each row in the table.

When the type argument is SQL_ROWVER, odbc_specialcolumns() returns the optimal column or set of columns that, by retrieving values from the column or columns, allows any row in the specified table to be uniquely identified.

Returns an ODBC result identifier or FALSE on failure.

The result set has the following columns:

SCOPE
COLUMN_NAME
DATA_TYPE
TYPE_NAME
PRECISION
LENGTH
SCALE
PSEUDO_COLUMN

The result set is ordered by SCOPE.

odbc_statistics

(PHP 4 )

odbc_statistics -- Retrieve statistics about a table

Description

resource odbc_statistics ( resource connection_id, string qualifier, string owner, string table_name, int unique, int accuracy)

Get statistics about a table and it's indexes. Returns an ODBC result identifier or FALSE on failure.

The result set has the following columns:

TABLE_QUALIFIER
TABLE_OWNER
TABLE_NAME
NON_UNIQUE
INDEX_QUALIFIER
INDEX_NAME
TYPE
SEQ_IN_INDEX
COLUMN_NAME
COLLATION
CARDINALITY
PAGES
FILTER_CONDITION

The result set is ordered by NON_UNIQUE, TYPE, INDEX_QUALIFIER, INDEX_NAME and SEQ_IN_INDEX.

odbc_tableprivileges

(PHP 4 )

odbc_tableprivileges -- Lists tables and the privileges associated with each table

Description

int odbc_tableprivileges ( resource connection_id [, string qualifier [, string owner [, string name]]])

Lists tables in the requested range and the privileges associated with each table. Returns an ODBC result identifier or FALSE on failure.

The result set has the following columns:

TABLE_QUALIFIER
TABLE_OWNER
TABLE_NAME
GRANTOR
GRANTEE
PRIVILEGE
IS_GRANTABLE

The result set is ordered by TABLE_QUALIFIER, TABLE_OWNER and TABLE_NAME.

The owner and name arguments accept search patterns ('%' to match zero or more characters and '_' to match a single character).

odbc_tables

(PHP 3>= 3.0.17, PHP 4 )

odbc_tables -- Get the list of table names stored in a specific data source. Returns a result identifier containing the information.

Description

int odbc_tables ( resource connection_id [, string qualifier [, string owner [, string name [, string types]]]])

Lists all tables in the requested range. Returns an ODBC result identifier or FALSE on failure.

The result set has the following columns:

TABLE_QUALIFIER
TABLE_OWNER
TABLE_NAME
TABLE_TYPE
REMARKS

The result set is ordered by TABLE_TYPE, TABLE_QUALIFIER, TABLE_OWNER and TABLE_NAME.

The owner and name arguments accept search patterns ('%' to match zero or more characters and '_' to match a single character).

To support enumeration of qualifiers, owners, and table types, the following special semantics for the qualifier, owner, name, and table_type are available:

If qualifier is a single percent character (%) and owner and name are empty strings, then the result set contains a list of valid qualifiers for the data source. (All columns except the TABLE_QUALIFIER column contain NULLs.)
If owner is a single percent character (%) and qualifier and name are empty strings, then the result set contains a list of valid owners for the data source. (All columns except the TABLE_OWNER column contain NULLs.)
If table_type is a single percent character (%) and qualifier, owner and name are empty strings, then the result set contains a list of valid table types for the data source. (All columns except the TABLE_TYPE column contain NULLs.)

If table_type is not an empty string, it must contain a list of comma-separated values for the types of interest; each value may be enclosed in single quotes (') or unquoted. For example, "'TABLE','VIEW'" or "TABLE, VIEW". If the data source does not support a specified table type, odbc_tables() does not return any results for that type.

See also odbc_tableprivileges() to retrieve associated privileges.

LXX. Object Aggregation/Composition Functions

Warning

Introduction

In Object Oriented Programming, it is common to see the composition of simple classes (and/or instances) into a more complex one. This is a flexible strategy for building complicated objects and object hierachies and can function as a dynamic alternative to multiple inheritance. There are two ways to perform class (and/or object) composition depending on the relationship between the composed elements: Association and Aggregation.

An Association is a composition of independently constructed and externally visible parts. When we associate classes or objects, each one keeps a reference to the ones it is associated with. When we associate classes statically, one class will contain a reference to an instance of the other class. For example:
Example 1. Class association
class DateTime { function DateTime() { // empty constructor } function now() { return date("Y-m-d H:i:s"); } } class Report { var $_dt = new DateTime(); // more properties ... function Report() { // initialization code ... } function generateReport() { $dateTime = $_dt->now(); // more code ... } // more methods ... } $rep = new Report();
We can also associate instances at runtime by passing a reference in a constructor (or any othe method), which allow us to dynamically change the association relationship between objects. We will modify the example above to illustrate this point:
Example 2. Object association
class DateTime { // same as previous example } class DateTimePlus { var $_format; function DateTimePlus($format="Y-m-d H:i:s") { $this->_format = $format } function now() { return date($this->_format); } } class Report { var $_dt; // we'll keep the reference to DateTime here // more properties ... function Report() { // do some initialization } function setDateTime(&$dt) { $this->_dt =& $dt; } function generateReport() { $dateTime = $_dt->now(); // more code ... } // more methods ... } $rep = new Report(); $dt = new DateTime(); $dtp = new DateTimePlus("l, F j, Y (h:i:s a, T)"); // generate report with simple date for web display $rep->setDateTime(&$dt); echo $rep->generateReport(); // later on in the code ... // generate report with fancy date $rep->setDateTime(&$dtp); $output = $rep->generateReport(); // save $output in database // ... etc ...

Aggregation, on the other hand, implies encapsulation (hidding) of the parts of the composition. We can aggregate classes by using a (static) inner class (PHP does not yet support inner classes), in this case the aggregated class definition is not accessible, except through the class that contains it. The aggregation of instances (object aggregation) involves the dynamic creation of subobjects inside an object, in the process, expanding the properties and methods of that object.

Object aggregation is a natural way of representing a whole-part relationship, (for example, molecules are aggregates of atoms), or can be used to obtain an effect equivalent to multiple inheritance, without having to permanently bind a subclass to two or more parent classes and their interfaces. In fact object aggregation can be more flexible, in which we can select what methods or properties to "inherit" in the aggregated object.

Examples

We define 3 classes, each implementing a different storage method:

Example 3. storage_classes.inc
<?php class FileStorage { var $data; function FileStorage($data) { $this->data = $data; } function write($name) { $fp = fopen(name, "w"); fwrite($fp, $this->data); fclose($data); } } class WDDXStorage { var $data; var $version = "1.0"; var $_id; // "private" variable function WDDXStorage($data) { $this->data = $data; $this->_id = $this->_genID(); } function store() { if ($this->_id) { $pid = wddx_packet_start($this->_id); wddx_add_vars($pid, "this->data"); $packet = wddx_packet_end($pid); } else { $packet = wddx_serialize_value($this->data); } $dbh = dba_open("varstore", "w", "gdbm"); dba_insert(md5(uniqid("",true)), $packet, $dbh); dba_close($dbh); } // a private method function _genID() { return md5(uniqid(rand(),true)); } } class DBStorage { var $data; var $dbtype = "mysql"; function DBStorage($data) { $this->data = $data; } function save() { $dbh = mysql_connect(); mysql_select_db("storage", $dbh); $serdata = serialize($this->data); mysql_query("insert into vars ('$serdata',now())", $dbh); mysql_close($dbh); } } ?>

We then instantiate a couple of objects from the defined classes, and perform some aggregations and deaggregations, printing some object information along the way:

Example 4. test_aggregation.php
<?php include "storageclasses.inc"; // some utilty functions function p_arr($arr) { foreach($arr as $k=>$v) $out[] = "\t$k => $v"; return implode("\n", $out); } function object_info($obj) { $out[] = "Class: ".get_class($obj); foreach(get_object_vars($obj) as $var=>$val) if (is_array($val)) $out[] = "property: $var (array)\n".p_arr($val); else $out[] = "property: $var = $val"; foreach(get_class_methods($obj) as $method) $out[] = "method: $method"; return implode("\n", $out); } $data = array(M_PI, "kludge != cruft"); // we create some basic objects $fs = new FileStorage($data); $ws = new WDDXStorage($data); // print information on the objects echo "\$fs object\n"; echo object_info($fs)."\n"; echo "\n\$ws object\n"; echo object_info($ws)."\n"; // do some aggregation echo "\nLet's aggregate \$fs to the WDDXStorage class\n"; aggregate($fs, "WDDXStorage"); echo "\$fs object\n"; echo object_info($fs)."\n"; echo "\nNow let us aggregate it to the DBStorage class\n"; aggregate($fs, "DBStorage"); echo "\$fs object\n"; echo object_info($fs)."\n"; echo "\nAnd finally deaggregate WDDXStorage\n"; deaggregate($fs, "WDDXStorage"); echo "\$fs object\n"; echo object_info($fs)."\n"; ?>

We will now consider the output to understand some of the side-effects and limitation of object aggregation in PHP. First, the newly created $fs and $ws objects give the expected output (according to their respective class declaration). Note that for the purposes of object aggregation, private elements of a class/object begin with an underscore character ("_"), even though there is not real distinction between public and private class/object elements in PHP.

$fs object
Class: filestorage
property: data (array)
	0 => 3.1415926535898
	1 => kludge != cruft
method: filestorage
method: write

$ws object
Class: wddxstorage
property: data (array)
	0 => 3.1415926535898
	1 => kludge != cruft
property: version = 1.0
property: _id = ID::9bb2b640764d4370eb04808af8b076a5
method: wddxstorage
method: store
method: _genid

We then aggregate $fs with the WDDXStorage class, and print out the object information. We can see now that even though nominally the $fs object is still of FileStorage, it now has the property $version, and the method store(), both defined in WDDXStorage. One important thing to note is that it has not aggregated the private elements defined in the class, which are present in the $ws object. Also absent is the constructor from WDDXStorage, which will not be logical to aggegate.

Let's aggregate $fs to the WDDXStorage class
$fs object
Class: filestorage
property: data (array)
	0 => 3.1415926535898
	1 => kludge != cruft
property: version = 1.0
method: filestorage
method: write
method: store

The proccess of aggregation is cummulative, so when we aggregate $fs with the class DBStorage, generating an object that can use the storage methods of all the defined classes.

Now let us aggregate it to the DBStorage class
$fs object
Class: filestorage
property: data (array)
	0 => 3.1415926535898
	1 => kludge != cruft
property: version = 1.0
property: dbtype = mysql
method: filestorage
method: write
method: store
method: save

Finally, the same way we aggregated properties and methods dynamically, we can also deaggregate them from the object. So, if we deaggregate the class WDDXStorage from $fs, we will obtain:

And deaggregate the WDDXStorage methods and properties
$fs object
Class: filestorage
property: data (array)
	0 => 3.1415926535898
	1 => kludge != cruft
property: dbtype = mysql
method: filestorage
method: write
method: save

One point that we have not mentioned above, is that the process of aggregation will not override existing properties or methods in the objects. For example, the class FileStorage defines a $data property, and the class WDDXStorage also defines a similar property which will not override the one in the object acquired during instantiation from the class FileStorage.

Table of Contents
aggregate_methods_by_list -- selective dynamic class methods aggregation to an object
aggregate_methods_by_regexp -- selective class methods aggregation to an object using a regular expression
aggregate_methods -- dynamic class and object aggregation of methods
aggregate_properties_by_list -- selective dynamic class properties aggregation to an object
aggregate_properties_by_regexp -- selective class properties aggregation to an object using a regular expression
aggregate_properties -- dynamic aggregation of class properties to an object
aggregate -- dynamic class and object aggregation of methods and properties
aggregation_info -- returns an associative array of the methods and properties from each class that has been aggregated to the object.
deaggregate -- removes the aggregated methods and properties from an object

(PHP 4 >= 4.2.0)

aggregate_properties_by_list -- selective dynamic class properties aggregation to an object

Description

void aggregate_properties_by_list ( object object, string class_name, array properties_list [, boolean exclude])

Aggregates properties from a class to an existing object using a list of property names. The optional paramater exclude is used to decide whether the list contains the names of class properties to include in the aggregation (i.e. exclude is FALSE, which is the default value), or to exclude from the aggregation (exclude is TRUE).

The properties whose names start with an underscore character (_), which are considered private to the aggregated class, are always excluded.

aggregate_properties_by_regexp

(PHP 4 >= 4.2.0)

aggregate_properties_by_regexp -- selective class properties aggregation to an object using a regular expression

Description

void aggregate_properties_by_regexp ( object object, string class_name, string regexp [, boolean exclude])

array aggregation_info ( object object)

Will return the aggretaion information for a particular object as an associative array of arrays of methods and properties. The key for the main array is the name of the aggregated class.

For example the code below
Example 1. Using aggregation_info()
<?php class Slicer { var $vegetable; function Slicer($vegetable) { $this->vegetable = $vegetable; } function slice_it($num_cuts) { echo "Doing some simple slicing\n"; for ($i=0; $i < $num_cuts; $i++) { // do some slicing } } } class Dicer { var $vegetable; var $rotation_angle = 90; // degrees function Dicer($vegetable) { $this->vegetable = $vegetable; } function dice_it($num_cuts) { echo "Cutting in one direction\n"; for ($i=0; $i < $num_cuts; $i++) { // do some cutting } $this->rotate($this->rotation_angle); echo "Cutting in a second direction\n"; for ($i=0; $i < $num_cuts; $i++) { // do some more cutting } } function rotate($deg) { echo "Now rotating {$this->vegetable} {$deg} degrees\n"; } function _secret_super_dicing($num_cuts) { // so secret we cannot show you ;-) } } $obj = new Slicer('onion'); aggregate($obj, 'Dicer'); print_r(aggregate_info($obj)); ?>

Will produce the output

Array
(
    [dicer] => Array
        (
            [methods] => Array
                (
                    [0] => dice_it
                    [1] => rotate
                )

            [properties] => Array
                (
                    [0] => rotation_angle
                )

        )

)

As you can see, all properties and methods of the Dicer class have been aggregated into our new object, with the exception of the class constructor and the method _secret_super_dicing

deaggregate

(PHP 4 >= 4.2.0)

deaggregate -- removes the aggregated methods and properties from an object

Description

void object_aggregation ( object object [, string class_name])

Removes the methods and properties from classes that were aggregated to an object. If the optional class_name parameters is passed, only those methods and properties defined in that class are removed, otherwise all aggregated methods and properties are eliminated.

LXXI. Oracle 8 functions

Introduction

These functions allow you to access Oracle8 and Oracle7 databases. It uses the Oracle8 Call-Interface (OCI8)

This extension is more flexible than the standard Oracle extension. It supports binding of global and local PHP variables to Oracle placeholders, has full LOB, FILE and ROWID support and allows you to use user-supplied define variables.

Requirements

You will need the Oracle8 client libraries to use this extension.

Before using this extension, make sure that you have set up your Oracle environment variables properly for the Oracle user, as well as your web daemon user. The variables you might need to set are as follows:

ORACLE_HOME
ORACLE_SID
LD_PRELOAD
LD_LIBRARY_PATH
NLS_LANG
ORA_NLS33

After setting up the environment variables for your webserver user, be sure to also add the webserver user (nobody, www) to the oracle group.

If your webserver doesn't start or crashes at startup: Check that Apache is linked with the pthread library:
# ldd /www/apache/bin/httpd 
    libpthread.so.0 => /lib/libpthread.so.0 (0x4001c000)
    libm.so.6 => /lib/libm.so.6 (0x4002f000)
    libcrypt.so.1 => /lib/libcrypt.so.1 (0x4004c000)
    libdl.so.2 => /lib/libdl.so.2 (0x4007a000)
    libc.so.6 => /lib/libc.so.6 (0x4007e000)
    /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x40000000)
If the libpthread is not listed you have to reinstall Apache:
# cd /usr/src/apache_1.3.xx
# make clean
# LIBS=-lpthread ./config.status
# make
# make install
Please note that on some systems like UnixWare it is libthread instead of libpthread. PHP and Apache have to be configured with EXTRA_LIBS=-lthread.

Installation

You have to compile PHP with the option --with-oci8[=DIR], where DIR defaults to your environmment variable ORACLE_HOME.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

OCI_DEFAULT (integer)
OCI_DESCRIBE_ONLY (integer)
OCI_COMMIT_ON_SUCCESS (integer)
OCI_EXACT_FETCH (integer)
SQLT_BFILEE (integer)
SQLT_CFILEE (integer)
SQLT_CLOB (integer)
SQLT_BLOB (integer)
SQLT_RDD (integer)
OCI_B_SQLT_NTY (integer)
OCI_SYSDATE (integer)
OCI_B_BFILE (integer)
OCI_B_CFILEE (integer)
OCI_B_CLOB (integer)
OCI_B_BLOB (integer)
OCI_B_ROWID (integer)
OCI_B_CURSOR (integer)
OCI_B_BIN (integer)
OCI_FETCHSTATEMENT_BY_COLUMN (integer)
OCI_FETCHSTATEMENT_BY_ROW (integer)
OCI_ASSOC (integer)
OCI_NUM (integer)
OCI_BOTH (integer)
OCI_RETURN_NULLS (integer)
OCI_RETURN_LOBS (integer)
OCI_DTYPE_FILE (integer)
OCI_DTYPE_LOB (integer)
OCI_DTYPE_ROWID (integer)
OCI_D_FILE (integer)
OCI_D_LOB (integer)
OCI_D_ROWID (integer)

Examples

Example 1. OCI Hints
<?php // by sergo@bacup.ru // Use option: OCI_DEFAULT for execute command to delay execution OCIExecute($stmt, OCI_DEFAULT); // for retrieve data use (after fetch): $result = OCIResult($stmt, $n); if (is_object ($result)) $result = $result->load(); // For INSERT or UPDATE statement use: $sql = "insert into table (field1, field2) values (field1 = 'value', field2 = empty_clob()) returning field2 into :field2"; OCIParse($conn, $sql); $clob = OCINewDescriptor($conn, OCI_D_LOB); OCIBindByName ($stmt, ":field2", &$clob, -1, OCI_B_CLOB); OCIExecute($stmt, OCI_DEFAULT); $clob->save ("some text"); OCICommit($conn); ?>

You can easily access stored procedures in the same way as you would from the commands line.
Example 2. Using Stored Procedures
<?php // by webmaster@remoterealty.com $sth = OCIParse ( $dbh, "begin sp_newaddress( :address_id, '$firstname', '$lastname', '$company', '$address1', '$address2', '$city', '$state', '$postalcode', '$country', :error_code );end;" ); // This calls stored procedure sp_newaddress, with :address_id being an // in/out variable and :error_code being an out variable. // Then you do the binding: OCIBindByName ( $sth, ":address_id", $addr_id, 10 ); OCIBindByName ( $sth, ":error_code", $errorcode, 10 ); OCIExecute ( $sth ); ?>

Table of Contents
OCIBindByName -- Bind a PHP variable to an Oracle Placeholder
OCICancel -- Cancel reading from cursor
OCICollAppend -- Coming soon
OCICollAssign -- Coming soon
OCICollAssignElem -- Coming soon
OCICollGetElem -- Coming soon
OCICollMax -- Coming soon
OCICollSize -- Coming soon
OCICollTrim -- Coming soon
OCIColumnIsNULL -- Test whether a result column is NULL
OCIColumnName -- Returns the name of a column
OCIColumnPrecision -- Coming soon
OCIColumnScale -- Coming soon
OCIColumnSize -- Return result column size
OCIColumnType -- Returns the data type of a column
OCIColumnTypeRaw -- Coming soon
OCICommit -- Commits outstanding transactions
OCIDefineByName -- Use a PHP variable for the define-step during a SELECT
OCIError -- Return the last error of stmt|conn|global
OCIExecute -- Execute a statement
OCIFetch -- Fetches the next row into result-buffer
OCIFetchInto -- Fetches the next row into result-array
OCIFetchStatement -- Fetch all rows of result data into an array
OCIFreeCollection -- Coming soon
OCIFreeCursor -- Free all resources associated with a cursor
OCIFreeDesc -- Deletes a large object descriptor
OCIFreeStatement -- Free all resources associated with a statement
OCIInternalDebug -- Enables or disables internal debug output
OCILoadLob -- Coming soon
OCILogOff -- Disconnects from Oracle
OCILogon -- Establishes a connection to Oracle
OCINewCollection -- Coming soon
OCINewCursor -- Return a new cursor (Statement-Handle)
OCINewDescriptor -- Initialize a new empty LOB or FILE descriptor
OCINLogon -- Establishes a new connection to Oracle
OCINumCols -- Return the number of result columns in a statement
OCIParse -- Parse a query and return a statement
OCIPLogon -- Connect to an Oracle database using a persistent connection
OCIResult -- Returns column value for fetched row
OCIRollback -- Rolls back outstanding transactions
OCIRowCount -- Gets the number of affected rows
OCISaveLob -- Coming soon
OCISaveLobFile -- Coming soon
OCIServerVersion -- Return a string containing server version information
OCISetPrefetch -- Sets number of rows to be prefetched
OCIStatementType -- Return the type of an OCI statement
OCIWriteLobToFile -- Coming soon

OCIBindByName

(PHP 3>= 3.0.4, PHP 4 )

OCIBindByName -- Bind a PHP variable to an Oracle Placeholder

Description

int OCIBindByName ( int stmt, string ph_name, mixed & variable, int length [, int type])

OCIBindByName() binds the PHP variable variable to the Oracle placeholder ph_name. Whether it will be used for input or output will be determined run-time, and the necessary storage space will be allocated. The length parameter sets the maximum length for the bind. If you set length to -1 OCIBindByName() will use the current length of variable to set the maximum length.

If you need to bind an abstract Datatype (LOB/ROWID/BFILE) you need to allocate it first using OCINewDescriptor() function. The length is not used for abstract Datatypes and should be set to -1. The type variable tells oracle, what kind of descriptor we want to use. Possible values are: OCI_B_FILE (Binary-File), OCI_B_CFILE (Character-File), OCI_B_CLOB (Character-LOB), OCI_B_BLOB (Binary-LOB) and OCI_B_ROWID (ROWID).

Example 1. OCIDefineByName

<?php
/* OCIBindByPos example thies@thieso.net (980221)
  inserts 3 records into emp, and uses the ROWID for updating the 
  records just after the insert.
*/

$conn = OCILogon("scott","tiger");

$stmt = OCIParse($conn,"insert into emp (empno, ename) ".
					   "values (:empno,:ename) ".
					   "returning ROWID into :rid");

$data = array(1111 => "Larry", 2222 => "Bill", 3333 => "Jim");

$rowid = OCINewDescriptor($conn,OCI_D_ROWID);

OCIBindByName($stmt,":empno",&$empno,32);
OCIBindByName($stmt,":ename",&$ename,32);
OCIBindByName($stmt,":rid",&$rowid,-1,OCI_B_ROWID);

$update = OCIParse($conn,"update emp set sal = :sal where ROWID = :rid");
OCIBindByName($update,":rid",&$rowid,-1,OCI_B_ROWID);
OCIBindByName($update,":sal",&$sal,32);

$sal = 10000;

while (list($empno,$ename) = each($data)) {
	OCIExecute($stmt);
	OCIExecute($update);
} 

$rowid->free();

OCIFreeStatement($update);
OCIFreeStatement($stmt);

$stmt = OCIParse($conn,"select * from emp where empno in (1111,2222,3333)");
OCIExecute($stmt);
while (OCIFetchInto($stmt,&$arr,OCI_ASSOC)) {
	var_dump($arr);
}
OCIFreeStatement($stmt);

/* delete our "junk" from the emp table.... */
$stmt = OCIParse($conn,"delete from emp where empno in (1111,2222,3333)");
OCIExecute($stmt);
OCIFreeStatement($stmt);

OCILogoff($conn);
?>

Warning

It is a bad idea to use magic quotes and OciBindByName() simultaneously as no quoting is needed on quoted variables and any quotes magically applied will be written into your database as OciBindByName() is not able to distinguish magically added quotings from those added by intention.

OCICancel

(PHP 3>= 3.0.8, PHP 4 )

OCICancel -- Cancel reading from cursor

int OCIExecute ( int statement [, int mode])

OCIExecute() executes a previously parsed statement. (see OCIParse()). The optional mode allows you to specify the execution-mode (default is OCI_COMMIT_ON_SUCCESS). If you don't want statements to be committed automatically specify OCI_DEFAULT as your mode.

Returns TRUE on success or FALSE on failure.

OCIFetch

(PHP 3>= 3.0.4, PHP 4 )

OCIFetch -- Fetches the next row into result-buffer

Description

int OCIFetch ( int statement)

OCIFetch() fetches the next row (for SELECT statements) into the internal result-buffer.

OCIFetchInto

(PHP 3>= 3.0.4, PHP 4 )

OCIFetchInto -- Fetches the next row into result-array

Description

int OCIFetchInto ( int stmt, array & result [, int mode])

OCIFetchInto() fetches the next row (for SELECT statements) into the result array. OCIFetchInto() will overwrite the previous content of result. By default result will contain a zero-based array of all columns that are not NULL.

The mode parameter allows you to change the default behaviour. You can specify more than one flag by simply adding them up (eg OCI_ASSOC+OCI_RETURN_NULLS). The known flags are:

OCI_ASSOC Return an associative array.

OCI_NUM Return an numbered array starting with zero. (DEFAULT)

OCI_RETURN_NULLS Return empty columns.

OCI_RETURN_LOBS Return the value of a LOB instead of the descriptor.

OCIFetchStatement

(PHP 3>= 3.0.8, PHP 4 )

OCIFetchStatement -- Fetch all rows of result data into an array

Description

int OCIFetchStatement ( int stmt, array & variable)

OCIFetchStatement() fetches all the rows from a result into a user-defined array. OCIFetchStatement() returns the number of rows fetched.

Example 1. OCIFetchStatement

<?php
/* OCIFetchStatement example mbritton@verinet.com (990624) */

$conn = OCILogon("scott","tiger");

$stmt = OCIParse($conn,"select * from emp");

OCIExecute($stmt);

$nrows = OCIFetchStatement($stmt,$results);
if ( $nrows > 0 ) {
   print "<TABLE BORDER=\"1\">\n";
   print "<TR>\n";
   while ( list( $key, $val ) = each( $results ) ) {
      print "<TH>$key</TH>\n";
   }
   print "</TR>\n";
   
   for ( $i = 0; $i < $nrows; $i++ ) {
      reset($results);
      print "<TR>\n";
      while ( $column = each($results) ) {   
         $data = $column['value'];
         print "<TD>$data[$i]</TD>\n";
      }
      print "</TR>\n";
   }
   print "</TABLE>\n";
} else {
   echo "No data found<BR>\n";
}      
print "$nrows Records Selected<BR>\n";
 
OCIFreeStatement($stmt);
OCILogoff($conn);
?>

OCIFreeCollection

(PHP 4 >= 4.1.0)

OCIFreeCollection -- Coming soon

Description

string OCIFreeCollection ( object lob)

string OCILoadLob ( object lob)

Warning

This function is currently not documented; only the argument list is available.

OCILogOff

(PHP 3>= 3.0.4, PHP 4 )

OCILogOff -- Disconnects from Oracle

Description

int OCILogOff ( int connection)

OCILogOff() closes an Oracle connection.

OCILogon

(PHP 3>= 3.0.4, PHP 4 )

OCILogon -- Establishes a connection to Oracle

Description

int OCILogon ( string username, string password [, string db])

OCILogon() returns an connection identifier needed for most other OCI calls. The optional third parameter can either contain the name of the local Oracle instance or the name of the entry in tnsnames.ora to which you want to connect. If the optional third parameter is not specified, PHP uses the environment variables ORACLE_SID (Oracle instance) or TWO_TASK (tnsnames.ora) to determine which database to connect to.

Connections are shared at the page level when using OCILogon(). This means that commits and rollbacks apply to all open transactions in the page, even if you have created multiple connections.

This example demonstrates how the connections are shared.
Example 1. OCILogon
<?php print "<HTML><PRE>"; $db = ""; $c1 = ocilogon("scott","tiger",$db); $c2 = ocilogon("scott","tiger",$db); function create_table($conn) { $stmt = ociparse($conn,"create table scott.hallo (test varchar2(64))"); ociexecute($stmt); echo $conn." created table\n\n"; } function drop_table($conn) { $stmt = ociparse($conn,"drop table scott.hallo"); ociexecute($stmt); echo $conn." dropped table\n\n"; } function insert_data($conn) { $stmt = ociparse($conn,"insert into scott.hallo values('$conn' || ' ' || to_char(sysdate,'DD-MON-YY HH24:MI:SS'))"); ociexecute($stmt,OCI_DEFAULT); echo $conn." inserted hallo\n\n"; } function delete_data($conn) { $stmt = ociparse($conn,"delete from scott.hallo"); ociexecute($stmt,OCI_DEFAULT); echo $conn." deleted hallo\n\n"; } function commit($conn) { ocicommit($conn); echo $conn." committed\n\n"; } function rollback($conn) { ocirollback($conn); echo $conn." rollback\n\n"; } function select_data($conn) { $stmt = ociparse($conn,"select * from scott.hallo"); ociexecute($stmt,OCI_DEFAULT); echo $conn."----selecting\n\n"; while (ocifetch($stmt)) echo $conn." <".ociresult($stmt,"TEST").">\n\n"; echo $conn."----done\n\n"; } create_table($c1); insert_data($c1); // Insert a row using c1 insert_data($c2); // Insert a row using c2 select_data($c1); // Results of both inserts are returned select_data($c2); rollback($c1); // Rollback using c1 select_data($c1); // Both inserts have been rolled back select_data($c2); insert_data($c2); // Insert a row using c2 commit($c2); // commit using c2 select_data($c1); // result of c2 insert is returned delete_data($c1); // delete all rows in table using c1 select_data($c1); // no rows returned select_data($c2); // no rows returned commit($c1); // commit using c1 select_data($c1); // no rows returned select_data($c2); // no rows returned drop_table($c1); print "</PRE></HTML>"; ?>

See also OCIPLogon() and OCINLogon().

OCINewCollection

(PHP 4 >= 4.0.6)

OCINewCollection -- Coming soon

Description

string OCINewCollection ( int conn, string tdo [, string shema])

Warning

This function is currently not documented; only the argument list is available.

OCINewCursor

(PHP 3>= 3.0.8, PHP 4 )

OCINewCursor -- Return a new cursor (Statement-Handle)

Description

int OCINewCursor ( int conn)

OCINewCursor() allocates a new statement handle on the specified connection.

Example 1. Using a REF CURSOR from a stored procedure
<?php // suppose your stored procedure info.output returns a ref cursor in :data $conn = OCILogon("scott","tiger"); $curs = OCINewCursor($conn); $stmt = OCIParse($conn,"begin info.output(:data); end;"); ocibindbyname($stmt,"data",&$curs,-1,OCI_B_CURSOR); ociexecute($stmt); ociexecute($curs); while (OCIFetchInto($curs,&$data)) { var_dump($data); } OCIFreeStatement($stmt); OCIFreeCursor($curs); OCILogoff($conn); ?>

Example 2. Using a REF CURSOR in a select statement
<?php print "<HTML><BODY>"; $conn = OCILogon("scott","tiger"); $count_cursor = "CURSOR(select count(empno) num_emps from emp " . "where emp.deptno = dept.deptno) as EMPCNT from dept"; $stmt = OCIParse($conn,"select deptno,dname,$count_cursor"); ociexecute($stmt); print "<TABLE BORDER=\"1\">"; print "<TR>"; print "<TH>DEPT NAME</TH>"; print "<TH>DEPT #</TH>"; print "<TH># EMPLOYEES</TH>"; print "</TR>"; while (OCIFetchInto($stmt,&$data,OCI_ASSOC)) { print "<TR>"; $dname = $data["DNAME"]; $deptno = $data["DEPTNO"]; print "<TD>$dname</TD>"; print "<TD>$deptno</TD>"; ociexecute($data["EMPCNT"]); while (OCIFetchInto($data["EMPCNT"],&$subdata,OCI_ASSOC)) { $num_emps = $subdata["NUM_EMPS"]; print "<TD>$num_emps</TD>"; } print "</TR>"; } print "</TABLE>"; print "</BODY></HTML>"; OCIFreeStatement($stmt); OCILogoff($conn); ?>

OCINewDescriptor

(PHP 3>= 3.0.7, PHP 4 )

OCINewDescriptor -- Initialize a new empty LOB or FILE descriptor

Description

string OCINewDescriptor ( int connection [, int type])

OCINewDescriptor() allocates storage to hold descriptors or LOB locators. Valid values for type are OCI_D_FILE, OCI_D_LOB, OCI_D_ROWID. For LOB descriptors, the methods load, save, and savefile are associated with the descriptor, for BFILE only the load method exists. See the second example usage hints.

Example 1. OCINewDescriptor

<?php   
    /* This script is designed to be called from a HTML form.
     * It expects $user, $password, $table, $where, and $commitsize
     * to be passed in from the form.  The script then deletes
     * the selected rows using the ROWID and commits after each
     * set of $commitsize rows. (Use with care, there is no rollback)
     */
    $conn = OCILogon($user, $password);
    $stmt = OCIParse($conn,"select rowid from $table $where");
    $rowid = OCINewDescriptor($conn,OCI_D_ROWID);
    OCIDefineByName($stmt,"ROWID",&$rowid);   
    OCIExecute($stmt);
    while ( OCIFetch($stmt) ) {      
       $nrows = OCIRowCount($stmt);
       $delete = OCIParse($conn,"delete from $table where ROWID = :rid");
       OCIBindByName($delete,":rid",&$rowid,-1,OCI_B_ROWID);
       OCIExecute($delete);      
       print "$nrows\n";
       if ( ($nrows % $commitsize) == 0 ) {
           OCICommit($conn);      
       }   
    }
    $nrows = OCIRowCount($stmt);   
    print "$nrows deleted...\n";
    OCIFreeStatement($stmt);  
    OCILogoff($conn);
?>

<?php
    /* This script demonstrates file upload to LOB columns
     * The formfield used for this example looks like this
     * <form action="upload.php" method="post" enctype="multipart/form-data">
     * <input type="file" name="lob_upload">
     * ...
     */
  if(!isset($lob_upload) || $lob_upload == 'none'){
?>
<form action="upload.php" method="post" enctype="multipart/form-data">
Upload file: <input type="file" name="lob_upload"><br>
<input type="submit" value="Upload"> - <input type="reset">
</form>
<?php
  } else {

     // $lob_upload contains the temporary filename of the uploaded file

     // see also the features section on file upload,
     // if you would like to use secure uploads
     
     $conn = OCILogon($user, $password);
     $lob = OCINewDescriptor($conn, OCI_D_LOB);
     $stmt = OCIParse($conn,"insert into $table (id, the_blob) 
               values(my_seq.NEXTVAL, EMPTY_BLOB()) returning the_blob into :the_blob");
     OCIBindByName($stmt, ':the_blob', &$lob, -1, OCI_B_BLOB);
     OCIExecute($stmt, OCI_DEFAULT);
     if($lob->savefile($lob_upload)){
        OCICommit($conn);
        echo "Blob successfully uploaded\n";
     }else{
        echo "Couldn't upload Blob\n";
     }
     OCIFreeDesc($lob);
     OCIFreeStatement($stmt);
     OCILogoff($conn);
  }
?>

Example 2. OCINewDescriptor

<?php   
    /* Calling PL/SQL stored procedures which contain clobs as input
     * parameters (PHP 4 >= 4.0.6). 
     * Example PL/SQL stored procedure signature is:
     *
     * PROCEDURE save_data
     *   Argument Name                  Type                    In/Out Default?
     *   ------------------------------ ----------------------- ------ --------
     *   KEY                            NUMBER(38)              IN
     *   DATA                           CLOB                    IN
     *
     */

    $conn = OCILogon($user, $password);
    $stmt = OCIParse($conn, "begin save_data(:key, :data); end;");
    $clob = OCINewDescriptor($conn, OCI_D_LOB);
	OCIBindByName($stmt, ':key', $key);
	OCIBindByName($stmt, ':data', $clob, -1, OCI_B_CLOB);
	$clob->WriteTemporary($data);
	OCIExecute($stmt, OCI_DEFAULT);
	OCICommit($conn);
	$clob->close();
	$clob->free();
	OCIFreeStatement($stmt);
?>

OCINLogon

(PHP 3>= 3.0.8, PHP 4 )

OCINLogon -- Establishes a new connection to Oracle

Description

int OCINLogon ( string username, string password [, string db])

OCINLogon() creates a new connection to an Oracle 8 database and logs on. The optional third parameter can either contain the name of the local Oracle instance or the name of the entry in tnsnames.ora to which you want to connect. If the optional third parameter is not specified, PHP uses the environment variables ORACLE_SID (Oracle instance) or TWO_TASK (tnsnames.ora) to determine which database to connect to.

OCINLogon() forces a new connection. This should be used if you need to isolate a set of transactions. By default, connections are shared at the page level if using OCILogon() or at the web server process level if using OCIPLogon(). If you have multiple connections open using OCINLogon(), all commits and rollbacks apply to the specified connection only.

This example demonstrates how the connections are separated.
Example 1. OCINLogon
<?php print "<HTML><PRE>"; $db = ""; $c1 = ocilogon("scott","tiger",$db); $c2 = ocinlogon("scott","tiger",$db); function create_table($conn) { $stmt = ociparse($conn,"create table scott.hallo (test varchar2(64))"); ociexecute($stmt); echo $conn." created table\n\n"; } function drop_table($conn) { $stmt = ociparse($conn,"drop table scott.hallo"); ociexecute($stmt); echo $conn." dropped table\n\n"; } function insert_data($conn) { $stmt = ociparse($conn,"insert into scott.hallo values('$conn' || ' ' || to_char(sysdate,'DD-MON-YY HH24:MI:SS'))"); ociexecute($stmt,OCI_DEFAULT); echo $conn." inserted hallo\n\n"; } function delete_data($conn) { $stmt = ociparse($conn,"delete from scott.hallo"); ociexecute($stmt,OCI_DEFAULT); echo $conn." deleted hallo\n\n"; } function commit($conn) { ocicommit($conn); echo $conn." committed\n\n"; } function rollback($conn) { ocirollback($conn); echo $conn." rollback\n\n"; } function select_data($conn) { $stmt = ociparse($conn,"select * from scott.hallo"); ociexecute($stmt,OCI_DEFAULT); echo $conn."----selecting\n\n"; while (ocifetch($stmt)) echo $conn." <".ociresult($stmt,"TEST").">\n\n"; echo $conn."----done\n\n"; } create_table($c1); insert_data($c1); select_data($c1); select_data($c2); rollback($c1); select_data($c1); select_data($c2); insert_data($c2); commit($c2); select_data($c1); delete_data($c1); select_data($c1); select_data($c2); commit($c1); select_data($c1); select_data($c2); drop_table($c1); print "</PRE></HTML>"; ?>

See also OCILogon() and OCIPLogon().

OCINumCols

(PHP 3>= 3.0.4, PHP 4 )

OCINumCols -- Return the number of result columns in a statement

Description

int OCINumCols ( int stmt)

OCINumCols() returns the number of columns in a statement.

Example 1. OCINumCols

<?php   
    print "<HTML><PRE>\n";   
    $conn = OCILogon("scott", "tiger");
    $stmt = OCIParse($conn,"select * from emp");
    OCIExecute($stmt);
    while ( OCIFetch($stmt) ) {
        print "\n";   
        $ncols = OCINumCols($stmt);
        for ( $i = 1; $i <= $ncols; $i++ ) {
            $column_name  = OCIColumnName($stmt,$i);
            $column_value = OCIResult($stmt,$i);
            print $column_name . ': ' . $column_value . "\n";
        }
        print "\n";
    }
    OCIFreeStatement($stmt);  
    OCILogoff($conn);   
    print "</PRE>";
    print "</HTML>\n"; 
?>

OCIParse

(PHP 3>= 3.0.4, PHP 4 )

OCIParse -- Parse a query and return a statement

Description

int OCIParse ( int conn, string query)

OCIParse() parses the query using conn. It returns the statement identity if the query is valid, FALSE if not. The query can be any valid SQL statement or PL/SQL block.

OCIPLogon

(PHP 3>= 3.0.8, PHP 4 )

OCIPLogon -- Connect to an Oracle database using a persistent connection

Description

int OCIPLogon ( string username, string password [, string db])

string OCIStatementType ( int stmt)

OCIStatementType() returns one of the following values:

"SELECT"
"UPDATE"
"DELETE"
"INSERT"
"CREATE"
"DROP"
"ALTER"
"BEGIN"
"DECLARE"
"UNKNOWN"

Example 1. OCIStatementType() examples
<?php print "<HTML><PRE>"; $conn = OCILogon("scott","tiger"); $sql = "delete from emp where deptno = 10"; $stmt = OCIParse($conn,$sql); if ( OCIStatementType($stmt) == "DELETE" ) { die "You are not allowed to delete from this table<BR>"; } OCILogoff($conn); print "</PRE></HTML>"; ?>

OCIWriteLobToFile

(PHP 4 )

OCIWriteLobToFile -- Coming soon

Description

void OCIWriteLobToFile ( object lob [, string filename [, int start [, int lenght]]])

Warning

This function is currently not documented; only the argument list is available.

LXXII. OpenSSL functions

Warning

Introduction

This module uses the functions of OpenSSL for generation and verification of signatures and for sealing (encrypting) and opening (decrypting) data. OpenSSL offers many features that this module currently doesn't support. Some of these may be added in the future.

Requirements

In order to use the OpenSSL functions you need to install the OpenSSL package. PHP-4.0.4pl1 requires OpenSSL >= 0.9.6, but PHP-4.0.5 and greater will also work with OpenSSL >= 0.9.5.

Installation

To use PHP's OpenSSL support you must also compile PHP --with-openssl[=DIR].

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

Key/Certificate parameters

Quite a few of the openssl functions require a key or a certificate parameter. PHP 4.0.5 and earlier have to use a key or certificate resource returned by one of the openssl_get_xxx functions. Later versions may use one of the following methods:

Certificates
1. An X.509 resource returned from openssl_x509_read()
2. A string having the format file://path/to/cert.pem; the named file must contain a PEM encoded certificate
3. A string containing the content of a certificate, PEM encoded
Public/Private Keys
1. A key resource returned from openssl_get_publickey() or openssl_get_privatekey()
2. For public keys only: an X.509 resource
3. A string having the format file://path/to/file.pem - the named file must contain a PEM encoded certificate/private key (it may contain both)
4. A string containing the content of a certificate/key, PEM encoded
5. For private keys, you may also use the syntax array($key, $passphrase) where $key represents a key specified using the file:// or textual content notation above, and $passphrase represents a string containing the passphrase for that private key

Certificate Verification

When calling a function that will verify a signature/certificate, the cainfo parameter is an array containing file and directory names that specify the locations of trusted CA files. If a directory is specified, then it must be a correctly formed hashed directory as the openssl command would use.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

X509_PURPOSE_SSL_CLIENT (integer)
X509_PURPOSE_SSL_SERVER (integer)
X509_PURPOSE_NS_SSL_SERVER (integer)
X509_PURPOSE_SMIME_SIGN (integer)
X509_PURPOSE_SMIME_ENCRYPT (integer)
X509_PURPOSE_CRL_SIGN (integer)
X509_PURPOSE_ANY (integer)
OPENSSL_PKCS1_PADDING (integer)
OPENSSL_SSLV23_PADDING (integer)
OPENSSL_NO_PADDING (integer)
OPENSSL_PKCS1_OAEP_PADDING (integer)
OPENSSL_KEYTYPE_RSA (integer)
OPENSSL_KEYTYPE_DSA (integer)
OPENSSL_KEYTYPE_DH (integer)

PKCS7 Flags/Constants

The S/MIME functions make use of flags which are specified using a bitfield which can include one or more of the following values:

Table 1. PKCS7 CONSTANTS

Constant	Description
PKCS7_TEXT	adds text/plain content type headers to encrypted/signed message. If decrypting or verifying, it strips those headers from the output - if the decrypted or verified message is not of MIME type text/plain then an error will occur.
PKCS7_BINARY	normally the input message is converted to "canonical" format which is effectively using CR and LF as end of line: as required by the S/MIME specification. When this options is present, no translation occurs. This is useful when handling binary data which may not be in MIME format.
PKCS7_NOINTERN	when verifying a message, certificates (if any) included in the message are normally searched for the signing certificate. With this option only the certificates specified in the `extracerts` parameter of openssl_pkcs7_verify() are used. The supplied certificates can still be used as untrusted CAs however.
PKCS7_NOVERIFY	do not verify the signers certificate of a signed message.
PKCS7_NOCHAIN	do not chain verification of signers certificates: that is don't use the certificates in the signed message as untrusted CAs.
PKCS7_NOCERTS	when signing a message the signer's certificate is normally included - with this option it is excluded. This will reduce the size of the signed message but the verifier must have a copy of the signers certificate available locally (passed using the `extracerts` to openssl_pkcs7_verify() for example.
PKCS7_NOATTR	normally when a message is signed, a set of attributes are included which include the signing time and the supported symmetric algorithms. With this option they are not included.
PKCS7_DETACHED	When signing a message, use cleartext signing with the MIME type multipart/signed. This is the default if the `flags` parameter to openssl_pkcs7_sign() if you do not specify any flags. If you turn this option off, the message will be signed using opaque signing, which is more resistant to translation by mail relays but cannot be read by mail agents that do not support S/MIME.
PKCS7_NOSIGS	Don't try and verify the signatures on a message

Note: These constants were added in 4.0.6.

Table of Contents
openssl_csr_export_to_file -- Exports a CSR to a file
openssl_csr_export -- Exports a CSR to file or a var
openssl_csr_new -- Generates a privkey and CSR
openssl_csr_sign -- Signs a cert with another CERT
openssl_error_string -- Return openSSL error message
openssl_free_key -- Free key resource
openssl_get_privatekey -- Prepare a PEM formatted private key for use
openssl_get_publickey -- Extract public key from certificate and prepare it for use
openssl_open -- Open sealed data
openssl_pkcs7_decrypt -- Decrypts an S/MIME encrypted message
openssl_pkcs7_encrypt -- Encrypt an S/MIME message
openssl_pkcs7_sign -- sign an S/MIME message
openssl_pkcs7_verify -- Verifies the signature of an S/MIME signed message
openssl_pkey_export_to_file -- Gets an exportable representation of a key into a file
openssl_pkey_export -- Gets an exportable representation of a key into a string or file
openssl_pkey_new -- Generates a new private key
openssl_private_decrypt -- Decrypts data with private key
openssl_private_encrypt -- Encrypts data with private key
openssl_public_decrypt -- Decrypts data with public key
openssl_public_encrypt -- Encrypts data with public key
openssl_seal -- Seal (encrypt) data
openssl_sign -- Generate signature
openssl_verify -- Verify signature
openssl_x509_check_private_key -- Checks if a private key corresponds to a CERT
openssl_x509_checkpurpose -- Verifies if a certificate can be used for a particular purpose
openssl_x509_export_to_file -- Exports a CERT to file or a var
openssl_x509_export -- Exports a CERT to file or a var
openssl_x509_free -- Free certificate resource
openssl_x509_parse -- Parse an X509 certificate and return the information as an array
openssl_x509_read -- Parse an X.509 certificate and return a resource identifier for it

openssl_error_string() returns the last error from the openSSL library. Error messages are stacked, so this function should be called multiple times to collect all of the information.

The parameters/return type of this function may change before it appears in a release version of PHP

Example 1. openssl_error_string() example
// lets assume you just called an openssl function that failed while($msg = openssl_error_string()) echo $msg . "<br />\n";

Note: This function was added in 4.0.6.

openssl_free_key

(PHP 4 >= 4.0.4)

openssl_free_key -- Free key resource

bool openssl_open ( string sealed_data, string open_data, string env_key, mixed priv_key_id)

Warning

Returns TRUE on success or FALSE on failure. If successful the opened data is returned in open_data.

openssl_open() opens (decrypts) sealed_data using the private key associated with the key identifier priv_key_id and the envelope key env_key, and fills open_data with the decrypted data. The envelope key is generated when the data are sealed and can only be used by one specific private key. See openssl_seal() for more information.

Example 1. openssl_open() example
// $sealed and $env_key are assumed to contain the sealed data // and our envelope key, both given to us by the sealer. // fetch private key from file and ready it $fp = fopen("/src/openssl-0.9.6/demos/sign/key.pem", "r"); $priv_key = fread($fp, 8192); fclose($fp); $pkeyid = openssl_get_privatekey($priv_key); // decrypt the data and store it in $open if (openssl_open($sealed, $open, $env_key, $pkeyid)) echo "here is the opened data: ", $open; else echo "failed to open data"; // free the private key from memory openssl_free_key($pkeyid);

openssl_pkcs7_decrypt

(PHP 4 >= 4.0.6)

openssl_pkcs7_decrypt -- Decrypts an S/MIME encrypted message

Description

bool openssl_pkcs7_decrypt ( string infilename, string outfilename, mixed recipcert, mixed recipkey)

Warning

Decrypts the S/MIME encrypted message contained in the file specified by infilename using the certificate and it's associated private key specified by recipcert and recipkey.

The decrypted message is output to the file specified by outfilename

Example 1. openssl_pkcs7_decrypt() example
// $cert and $key are assumed to contain your personal certificate and private // key pair, and that you are the recipient of an S/MIME message $infilename = "encrypted.msg"; // this file holds your encrypted message $outfilename = "decrypted.msg"; // make sure you can write to this file if (openssl_pkcs7_decrypt($infilename, $outfilename, $cert, $key)) echo "decrypted!"; else echo "failed to decrypt!";

Note: This function was added in 4.0.6.

openssl_pkcs7_encrypt

(PHP 4 >= 4.0.6)

openssl_pkcs7_encrypt -- Encrypt an S/MIME message

Description

bool openssl_pkcs7_encrypt ( string infile, string outfile, mixed recipcerts, array headers [, long flags])

Warning

openssl_pkcs7_encrypt() takes the contents of the file named infile and encrypts them using an RC2 40-bit cipher so that they can only be read by the intended recipients specified by recipcerts, which is either a lone X.509 certificate, or an array of X.509 certificates. headers is an array of headers that will be prepended to the data after it has been encrypted. flags can be used to specify options that affect the encoding process - see PKCS7 constants. headers can be either an associative array keyed by header name, or an indexed array, where each element contains a single header line.

Example 1. openssl_pkcs7_encrypt() example
// the message you want to encrypt and send to your secret agent // in the field, known as nighthawk. You have his certificate // in the file nighthawk.pem $data = <<<EOD Nighthawk, Top secret, for your eyes only! The enemy is closing in! Meet me at the cafe at 8.30am to collect your forged passport! HQ EOD; // load key $key = implode("", file("nighthawk.pem")); // save message to file $fp = fopen("msg.txt", "w"); fwrite($fp, $data); fclose($fp); // encrypt it if (openssl_pkcs7_encrypt("msg.txt", "enc.txt", $key, array("To" => "nighthawk@example.com", // keyed syntax "From: HQ <hq@example.com>", // indexed syntax "Subject" => "Eyes only"))) { // message encrypted - send it! exec(ini_get("sendmail_path") . " < enc.txt"); }

openssl_pkcs7_sign

(PHP 4 >= 4.0.6)

openssl_pkcs7_sign -- sign an S/MIME message

Description

bool openssl_pkcs7_sign ( string infilename, string outfilename, mixed signcert, mixed privkey, array headers [, long flags [, string extracertsfilename]])

Warning

openssl_pkcs7_sign() takes the contents of the file named infilename and signs them using the certificate and it's matching private key specified by signcert and privkey parameters.

headers is an array of headers that will be prepended to the data after it has been signed (see openssl_pkcs7_encrypt() for more information about the format of this parameter.

flags can be used to alter the output - see PKCS7 constants - if not specified, it defaults to PKCS7_DETACHED.

extracerts specifies the name of a file containing a bunch of extra certificates to include in the signature which can for example be used to help the recipient to verify the certificate that you used.

Example 1. openssl_pkcs7_sign() example
// the message you want to sign so that recipient can be sure it was you that // sent it $data = <<<EOD You have my authorization to spend $10,000 on dinner expenses. The CEO EOD; // save message to file $fp = fopen("msg.txt", "w"); fwrite($fp, $data); fclose($fp); // encrypt it if (openssl_pkcs7_sign("msg.txt", "signed.txt", "mycert.pem", array("mycert.pem", "mypassphrase"), array("To" => "joes@sales.com", // keyed syntax "From: HQ <ceo@sales.com>", // indexed syntax "Subject" => "Eyes only")) { // message signed - send it! exec(ini_get("sendmail_path") . " < signed.txt"); }

Note: This function was added in 4.0.6.

openssl_pkcs7_verify

(PHP 4 >= 4.0.6)

openssl_pkcs7_verify -- Verifies the signature of an S/MIME signed message

Description

bool openssl_pkcs7_verify ( string filename, int flags [, string outfilename [, array cainfo [, string extracerts]]])

Warning

openssl_pkcs7_verify() reads the S/MIME message contained in the filename specified by filename and examines the digital signature. It returns TRUE if the signature is verified, FALSE if it is not correct (the message has been tampered with, or the signing certificate is invalid), or -1 on error.

flags can be used to affect how the signature is verified - see PKCS7 constants for more information.

If the outfilename is specified, it should be a string holding the name of a file into which the certificates of the persons that signed the messages will be stored in PEM format.

If the cainfo is specified, it should hold information about the trusted CA certificates to use in the verification process - see certificate verification for more information about this parameter.

If the extracerts is specified, it is the filename of a file containing a bunch of certificates to use as untrusted CAs.

Note: This function was added in 4.0.6.

openssl_x509_checkpurpose

(PHP 4 >= 4.0.6)

openssl_x509_checkpurpose -- Verifies if a certificate can be used for a particular purpose

Description

bool openssl_x509_checkpurpose ( mixed x509cert, int purpose, array cainfo [, string untrustedfile])

Warning

Returns TRUE if the certificate can be used for the intended purpose, FALSE if it cannot, or -1 on error.

openssl_x509_checkpurpose() examines the certificate specified by x509cert to see if it can be used for the purpose specified by purpose.

cainfo should be an array of trusted CA files/dirs as described in Certificate Verification.

untrustedfile, if specified, is the name of a PEM encoded file holding certificates that can be used to help verify the certificate, although no trust in placed in the certificates that come from that file.

Table 1. openssl_x509_checkpurpose() purposes

Constant	Description
X509_PURPOSE_SSL_CLIENT	Can the certificate be used for the client side of an SSL connection?
X509_PURPOSE_SSL_SERVER	Can the certificate be used for the server side of an SSL connection?
X509_PURPOSE_NS_SSL_SERVER	Can the cert be used for Netscape SSL server?
X509_PURPOSE_SMIME_SIGN	Can the cert be used to sign S/MIME email?
X509_PURPOSE_SMIME_ENCRYPT	Can the cert be used to encrypt S/MIME email?
X509_PURPOSE_CRL_SIGN	Can the cert be used to sign a certificate revocation list (CRL)?
X509_PURPOSE_ANY	Can the cert be used for Any/All purposes?

These options are not bitfields - you may specify one only!

Note: This function was added in 4.0.6.

Note: This function was added in 4.0.6.

openssl_x509_parse

(PHP 4 >= 4.0.6)

openssl_x509_parse -- Parse an X509 certificate and return the information as an array

Description

array openssl_x509_parse ( mixed x509cert [, bool shortnames])

Warning

openssl_x509_parse() returns information about the supplied x509cert, including fields such as subject name, issuer name, purposes, valid from and valid to dates etc. shortnames controls how the data is indexed in the array - if shortnames is TRUE (the default) then fields will be indexed with the short name form, otherwise, the long name form will be used - e.g.: CN is the shortname form of commonName.

The structure of the returned data is (deliberately) not yet documented, as it is still subject to change.

Note: This function was added in 4.0.6.

openssl_x509_read

(PHP 4 >= 4.0.6)

openssl_x509_read -- Parse an X.509 certificate and return a resource identifier for it

Description

resource openssl_x509_read ( mixed x509certdata)

Warning

openssl_x509_read() parses the certificate supplied by x509certdata and returns a resource identifier for it.

Note: This function was added in 4.0.6.

LXXIII. Oracle functions

Introduction

This extension adds support for Oracle database server access. See also the OCI8 extension.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

ORA_BIND_INOUT (integer)
ORA_BIND_IN (integer)
ORA_BIND_OUT (integer)
ORA_FETCHINTO_ASSOC (integer)
ORA_FETCHINTO_NULLS (integer)

Table of Contents
Ora_Bind -- bind a PHP variable to an Oracle parameter
Ora_Close -- close an Oracle cursor
Ora_ColumnName -- get name of Oracle result column
Ora_ColumnSize -- get size of Oracle result column
Ora_ColumnType -- get type of Oracle result column
Ora_Commit -- commit an Oracle transaction
Ora_CommitOff -- disable automatic commit
Ora_CommitOn -- enable automatic commit
Ora_Do -- Parse, Exec, Fetch
Ora_Error -- get Oracle error message
Ora_ErrorCode -- get Oracle error code
Ora_Exec -- execute parsed statement on an Oracle cursor
Ora_Fetch_Into -- Fetch a row into the specified result array
Ora_Fetch -- fetch a row of data from a cursor
Ora_GetColumn -- get data from a fetched column
Ora_Logoff -- close an Oracle connection
Ora_Logon -- open an Oracle connection
Ora_Numcols -- Returns the number of columns
Ora_Numrows -- Returns the number of rows
Ora_Open -- open an Oracle cursor
Ora_Parse -- parse an SQL statement
Ora_pLogon -- Open a persistent Oracle connection
Ora_Rollback -- roll back transaction

Ora_Bind

(PHP 3, PHP 4 )

Ora_Bind -- bind a PHP variable to an Oracle parameter

Description

int ora_bind ( int cursor, string PHP variable name, string SQL parameter name, int length [, int type])

Returns TRUE if the bind succeeds, otherwise FALSE. Details about the error can be retrieved using the ora_error() and ora_errorcode() functions.

This function binds the named PHP variable with a SQL parameter. The SQL parameter must be in the form ":name". With the optional type parameter, you can define whether the SQL parameter is an in/out (0, default), in (1) or out (2) parameter. As of PHP 3.0.1, you can use the constants ORA_BIND_INOUT, ORA_BIND_IN and ORA_BIND_OUT instead of the numbers.

ora_bind must be called after ora_parse() and before ora_exec(). Input values can be given by assignment to the bound PHP variables, after calling ora_exec() the bound PHP variables contain the output values if available.

<?php
ora_parse($curs, "declare tmp INTEGER; begin tmp := :in; :out := tmp; :x := 7.77; end;");
ora_bind($curs, "result", ":x", $len, 2);
ora_bind($curs, "input", ":in", 5, 1);
ora_bind($curs, "output", ":out", 5, 2);
$input = 765;
ora_exec($curs);
echo "Result: $result<BR>Out: $output<BR>In: $input";
?>

Ora_Close

(PHP 3, PHP 4 )

Ora_Close -- close an Oracle cursor

Description

int ora_close ( int cursor)

string Ora_ColumnType ( int cursor, int column)

Returns the Oracle data type name of the field/column column on the cursor cursor. Column 0 is the first column. The returned type will be one of the following:

"VARCHAR2"

"VARCHAR"

"CHAR"

"NUMBER"

"LONG"

"LONG RAW"

string Ora_Error ( int cursor_or_connection)

Returns an error message of the form XXX-NNNNN where XXX is where the error comes from and NNNNN identifies the error message.

Note: Support for connection ids was added in 3.0.4.

On UNIX versions of Oracle, you can find details about an error message like this: $ oerr ora 00001 00001, 00000, "unique constraint (%s.%s) violated" // *Cause: An update or insert statement attempted to insert a duplicate key // For Trusted ORACLE configured in DBMS MAC mode, you may see // this message if a duplicate entry exists at a different level. // *Action: Either remove the unique restriction or do not insert the key

Ora_ErrorCode

(PHP 3, PHP 4 )

Ora_ErrorCode -- get Oracle error code

Description

int Ora_ErrorCode ( int cursor_or_connection)

Returns the numeric error code of the last executed statement on the specified cursor or connection.

Note: Support for connection ids was added in 3.0.4.

Ora_Exec

(PHP 3, PHP 4 )

Ora_Exec -- execute parsed statement on an Oracle cursor

Description

int ora_exec ( int cursor)

Returns TRUE on success or FALSE on failure. Details about the error can be retrieved using the ora_error() and ora_errorcode() functions.

Ora_Fetch_Into

(PHP 3, PHP 4 )

Ora_Fetch_Into -- Fetch a row into the specified result array

Description

int ora_fetch_into ( int cursor, array result [, int flags])

Ora_Parse

(PHP 3, PHP 4 )

Ora_Parse -- parse an SQL statement

Description

int ora_parse ( int cursor_ind, string sql_statement, int defer)

This function parses an SQL statement or a PL/SQL block and associates it with the given cursor.

Returns TRUE on success or FALSE on failure.

See also ora_exec(), ora_fetch(), and ora_do().

Ora_pLogon

(PHP 3, PHP 4 )

Ora_pLogon -- Open a persistent Oracle connection

Description

int ora_plogon ( string user, string password)

Establishes a persistent connection between PHP and an Oracle database with the given username and password.

Ora_Rollback

(PHP 3, PHP 4 )

Ora_Rollback -- roll back transaction

Description

int ora_rollback ( int connection)

This function undoes an Oracle transaction. (See ora_commit() for the definition of a transaction.)

Returns TRUE on success or FALSE on failure. Details about the error can be retrieved using the ora_error() and ora_errorcode() functions.

LXXIV. Ovrimos SQL functions

Introduction

Ovrimos SQL Server, is a client/server, transactional RDBMS combined with Web capabilities and fast transactions.

Requirements

Ovrimos SQL Server is available at http://www.ovrimos.com/. You'll need to install the sqlcli library available in the Ovrimos SQL Server distribution.

Installation

To enable Ovrimos support in PHP just compile PHP with the --with-ovrimos parameter to configure script.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

Examples

Example 1. Connect to Ovrimos SQL Server and select from a system table
<?php $conn = ovrimos_connect ("server.domain.com", "8001", "admin", "password"); if ($conn != 0) { echo ("Connection ok!"); $res = ovrimos_exec ($conn, "select table_id, table_name from sys.tables"); if ($res != 0) { echo "Statement ok!"; ovrimos_result_all ($res); ovrimos_free_result ($res); } ovrimos_close($conn); } ?>
This will just connect to an Ovrimos SQL server.

Table of Contents
ovrimos_close -- Closes the connection to ovrimos
ovrimos_commit -- Commits the transaction
ovrimos_connect -- Connect to the specified database
ovrimos_cursor -- Returns the name of the cursor
ovrimos_exec -- Executes an SQL statement
ovrimos_execute -- Executes a prepared SQL statement
ovrimos_fetch_into -- Fetches a row from the result set
ovrimos_fetch_row -- Fetches a row from the result set
ovrimos_field_len -- Returns the length of the output column
ovrimos_field_name -- Returns the output column name
ovrimos_field_num -- Returns the (1-based) index of the output column
ovrimos_field_type -- Returns the (numeric) type of the output column
ovrimos_free_result -- Frees the specified result_id
ovrimos_longreadlen -- Specifies how many bytes are to be retrieved from long datatypes
ovrimos_num_fields -- Returns the number of columns
ovrimos_num_rows -- Returns the number of rows affected by update operations
ovrimos_prepare -- Prepares an SQL statement
ovrimos_result_all -- Prints the whole result set as an HTML table
ovrimos_result -- Retrieves the output column
ovrimos_rollback -- Rolls back the transaction

ovrimos_fetch_into() fetches a row from the result set into 'result_array', which should be passed by reference. Which row is fetched is determined by the two last parameters. 'how' is one of 'Next' (default), 'Prev', 'First', 'Last', 'Absolute', corresponding to forward direction from current position, backward direction from current position, forward direction from the start, backward direction from the end and absolute position from the start (essentially equivalent to 'first' but needs 'rownumber'). Case is not significant. 'Rownumber' is optional except for absolute positioning. Returns TRUE or FALSE.

Example 1. A fetch into example
<?php $conn=ovrimos_connect ("neptune", "8001", "admin", "password"); if ($conn!=0) { echo "Connection ok!"; $res=ovrimos_exec ($conn,"select table_id, table_name from sys.tables"); if ($res != 0) { echo "Statement ok!"; if (ovrimos_fetch_into ($res, &$row)) { list ($table_id, $table_name) = $row; echo "table_id=".$table_id.", table_name=".$table_name."\n"; if (ovrimos_fetch_into ($res, &$row)) { list ($table_id, $table_name) = $row; echo "table_id=".$table_id.", table_name=".$table_name."\n"; } else { echo "Next: error\n"; } } else { echo "First: error\n"; } ovrimos_free_result ($res); } ovrimos_close($conn); } ?>
This example will fetch a row.

ovrimos_fetch_row

(PHP 4 >= 4.0.3)

ovrimos_fetch_row -- Fetches a row from the result set

Description

bool ovrimos_fetch_row ( int result_id [, int how [, int row_number]])

int ovrimos_prepare ( int connection_id, string query)

ovrimos_prepare() is used to prepare an SQL statement.

ovrimos_prepare() prepares an SQL statement and returns a result_id (or FALSE on failure).

Example 1. Connect to Ovrimos SQL Server and prepare a statement
<?php $conn=ovrimos_connect ("db_host", "8001", "admin", "password"); if ($conn!=0) { echo "Connection ok!"; $res=ovrimos_prepare ($conn, "select table_id, table_name from sys.tables where table_id=1"); if ($res != 0) { echo "Prepare ok!"; if (ovrimos_execute ($res)) { echo "Execute ok!\n"; ovrimos_result_all ($res); } else { echo "Execute not ok!"; } ovrimos_free_result ($res); } else { echo "Prepare not ok!\n"; } ovrimos_close($conn); } ?>
This will connect to Ovrimos SQL Server, prepare a statement and the execute it.

ovrimos_result_all

(PHP 4 >= 4.0.3)

ovrimos_result_all -- Prints the whole result set as an HTML table

Description

bool ovrimos_result_all ( int result_id [, string format])

ovrimos_result_all() is used to print an HTML table containing the whole result set.

ovrimos_result_all() prints the whole result set as an HTML table. Returns TRUE or FALSE.

Example 1. Prepare a statement, execute, and view the result
<?php $conn = ovrimos_connect ("db_host", "8001", "admin", "password"); if ($conn != 0) { echo "Connection ok!"; $res = ovrimos_prepare ($conn, "select table_id, table_name from sys.tables where table_id = 7"); if ($res != 0) { echo "Prepare ok!"; if (ovrimos_execute ($res, array(3))) { echo "Execute ok!\n"; ovrimos_result_all ($res); } else { echo "Execute not ok!"; } ovrimos_free_result ($res); } else { echo "Prepare not ok!\n"; } ovrimos_close($conn); } ?>
This will execute an SQL statement and print the result in an HTML table.

Example 2. Ovrimos_result_all with meta-information
<?php $conn = ovrimos_connect ("db_host", "8001", "admin", "password"); if ($conn != 0) { echo "Connection ok!"; $res = ovrimos_exec ($conn, "select table_id, table_name from sys.tables where table_id = 1") if ($res != 0) { echo "Statement ok! cursor=".ovrimos_cursor ($res)."\n"; $colnb = ovrimos_num_fields ($res); echo "Output columns=".$colnb."\n"; for ($i=1; $i <= $colnb; $i++) { $name = ovrimos_field_name ($res, $i); $type = ovrimos_field_type ($res, $i); $len = ovrimos_field_len ($res, $i); echo "Column ".$i." name=".$name." type=".$type." len=".$len."\n"; } ovrimos_result_all ($res); ovrimos_free_result ($res); } ovrimos_close($conn); } ?>

Example 3. ovrimos_result_all example
<?php $conn = ovrimos_connect ("db_host", "8001", "admin", "password"); if ($conn != 0) { echo "Connection ok!"; $res = ovrimos_exec ($conn, "update test set i=5"); if ($res != 0) { echo "Statement ok!"; echo ovrimos_num_rows ($res)." rows affected\n"; ovrimos_free_result ($res); } ovrimos_close($conn); } ?>

ovrimos_result

(PHP 4 >= 4.0.3)

ovrimos_result -- Retrieves the output column

Description

int ovrimos_result ( int result_id, mixed field)

ovrimos_result() is used to retrieve the output column.

ovrimos_result() retrieves the output column specified by 'field', either as a string or as an 1-based index.

ovrimos_rollback

(PHP 4 >= 4.0.3)

ovrimos_rollback -- Rolls back the transaction

Description

int ovrimos_rollback ( int connection_id)

ovrimos_rollback() is used to roll back the transaction.

ovrimos_rollback() rolls back the transaction.

LXXV. Output Control Functions

Introduction

The Output Control functions allow you to control when output is sent from the script. This can be useful in several different situations, especially if you need to send headers to the browser after your script has began outputting data. The Output Control functions do not affect headers sent using header() or setcookie(), only functions such as echo() and data between blocks of PHP code.

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Output Control configuration options

Name	Default	Changeable
output_buffering	"0"	PHP_INI_PERDIR\|PHP_INI_SYSTEM
output_handler	NULL	PHP_INI_PERDIR\|PHP_INI_SYSTEM
implicit_flush	"0"	PHP_INI_PERDIR\|PHP_INI_SYSTEM

For further details and definition of the PHP_INI_* constants see ini_set().

Here is a short explanation of the configuration directives.

output_buffering boolean/integer

You can enable output buffering for all files by setting this directive to 'On'. If you wish to limit the size of the buffer to a certain size - you can use a maximum number of bytes instead of 'On', as a value for this directive (e.g., output_buffering=4096).

output_handler string

You can redirect all of the output of your scripts to a function. For example, if you set output_handler to mb_output_handler(), character encoding will be transparently converted to the specified encoding. Setting any output handler automatically turns on output buffering.

Note: You cannot use both mb_output_handler() with ob_inconv_handler() and you cannot use both ob_gzhandler() and zlib.output_compression.

implicit_flush boolean

FALSE by default. Changing this to TRUE tells PHP to tell the output layer to flush itself automatically after every output block. This is equivalent to calling the PHP function flush() after each and every call to print() or echo() and each and every HTML block.

When using PHP within an web environment, turning this option on has serious performance implications and is generally recommended for debugging purposes only. This value defaults to TRUE when operating under the CLI SAPI.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Examples

Example 1. Output Control example
<?php ob_start(); echo "Hello\n"; setcookie ("cookiename", "cookiedata"); ob_end_flush(); ?>

In the above example, the output from echo() would be stored in the output buffer until ob_end_flush() was called. In the mean time, the call to setcookie() successfully stored a cookie without causing an error. (You can not normally send headers to the browser after data has already been sent.)

Note: When upgrading from PHP 4.1 (& 4.2) to 4.3 that due to a bug in earlier versions you must ensure that implict_flush is OFF in your php.ini, otherwise any output with ob_start() will be not be hidden from output.

flush

(PHP 3, PHP 4 )

flush -- Flush the output buffer

Description

void flush ( void)

Flushes the output buffers of PHP and whatever backend PHP is using (CGI, a web server, etc). This effectively tries to push all the output so far to the user's browser.

Note: flush() has no effect on the buffering scheme of your webserver or the browser on the client side.
Several servers, especially on Win32, will still buffer the output from your script until it terminates before transmitting the results to the browser.
Server modules for Apache like mod_gzip may do buffering of their own that will cause flush() to not result in data being sent immediately to the client.
Even the browser may buffer its input before displaying it. Netscape, for example, buffers text until it receives an end-of-line or the beginning of a tag, and it won't render tables until the </table> tag of the outermost table is seen.
Some versions of Microsoft Internet Explorer will only start to display the page after they have received 256 bytes of output, so you may need to send extra whitespace before flushing to get those browsers to display the page.

ob_clean

(PHP 4 >= 4.2.0)

ob_clean -- Clean (erase) the output buffer

Description

void ob_clean ( void)

void ob_flush ( void)

This function will send the contents of the output buffer (if any). If you want to further process the buffer's contents you have to call ob_get_contents() before ob_flush() as the buffer contents are discarded after ob_flush() is called.

This function does not destroy the output buffer like ob_end_flush() does.

ob_get_contents

(PHP 4 )

ob_get_contents -- Return the contents of the output buffer

Description

string ob_get_contents ( void)

array ob_get_status ( [bool full_status])

Warning

This will return the current status of output buffers. It returns array contains buffer status or FALSE for error.

ob_gzhandler

(PHP 4 >= 4.0.4)

ob_gzhandler -- ob_start callback function to gzip output buffer

Description

string ob_gzhandler ( string buffer [, int mode])

Note: mode was added in PHP 4.0.5.

ob_gzhandler() is intended to be used as a callback function for ob_start() to help facilitate sending gz-encoded data to web browsers that support compressed web pages. Before ob_gzhandler() actually sends compressed data, it determines what type of content encoding the browser will accept ("gzip", "deflate" or none at all) and will return it's output accordingly. All browsers are supported since it's up to the browser to send the correct header saying that it accepts compressed web pages.

Example 1. ob_gzhandler() Example
<?php ob_start("ob_gzhandler"); ?> <html> <body> <p>This should be a compressed page. </html> <body>

See also ob_start() and ob_end_flush().

ob_implicit_flush

(PHP 4 )

ob_implicit_flush -- Turn implicit flush on/off

Description

void ob_implicit_flush ( [int flag])

ob_implicit_flush() will turn implicit flushing on or off (if no flag is given, it defaults to on). Implicit flushing will result in a flush operation after every output call, so that explicit calls to flush() will no longer be needed.

Turning implicit flushing on will disable output buffering, the output buffers current output will be sent as if ob_end_flush() had been called.

ob_start

(PHP 4 )

ob_start -- Turn on output buffering

Description

void ob_start ( [string output_callback])

This function will turn output buffering on. While output buffering is active no output is sent from the script (other than headers), instead the output is stored in an internal buffer.

The contents of this internal buffer may be copied into a string variable using ob_get_contents(). To output what is stored in the internal buffer, use ob_end_flush(). Alternatively, ob_end_clean() will silently discard the buffer contents.

An optional output_callback function may be specified. This function takes a string as a parameter and should return a string. The function will be called when ob_end_flush() is called, or when the output buffer is flushed to the browser at the end of the request. When output_callback is called, it will receive the contents of the output buffer as its parameter and is expected to return a new output buffer as a result, which will be sent to the browser.

Note: In PHP 4.0.4, ob_gzhandler() was introduced to facilitate sending gz-encoded data to web browsers that support compressed web pages. ob_gzhandler() determines what type of content encoding the browser will accept and will return it's output accordingly.

Output buffers are stackable, that is, you may call ob_start() while another ob_start() is active. Just make sure that you call ob_end_flush() the appropriate number of times. If multiple output callback functions are active, output is being filtered sequentially through each of them in nesting order.

ob_end_clean(), ob_end_flush(), ob_clean(), ob_flush() and ob_start() may not be called from a callback function. If you call them from callback function, the behavior is undefined. If you would like to delete the contents of a buffer, return "" (a null string) from callback function.

Example 1. User defined callback function example

<?php

function callback($buffer) {

  // replace all the apples with oranges
  return (ereg_replace("apples", "oranges", $buffer));

}

ob_start("callback");

?>

<html>
<body>
<p>It's like comparing apples to oranges.
</body>
</html>

<?php

ob_end_flush();

?>

Would produce:

<html>
<body>
<p>It's like comparing oranges to oranges.
</body>
</html>

LXXVI. Object property and method call overloading

Introduction

The purpose of this extension is to allow overloading of object property access and method calls. Only one function is defined in this extension, overload() which takes the name of the class that should have this functionality enabled. The class named has to define appropriate methods if it wants to have this functionality: __get(), __set() and __call() respectively for getting/setting a property, or calling a method. This way overloading can be selective. Inside these handler functions the overloading is disabled so you can access object properties normally.

Warning

Requirements

No external libraries are needed to build this extension.

Installation

In order to use these functions, you must compile PHP with the --enable-overload option.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Examples

Some simple examples on using the overload() function:
Example 1. Overloading a PHP class
<?php class OO { var $a = 111; var $elem = array('b' => 9, 'c' => 42); // Callback method for getting a property function __get($prop_name, &$prop_value) { if (isset($this->elem[$prop_name])) { $prop_value = $this->elem[$prop_name]; return true; } else { return false; } } // Callback method for setting a property function __set($prop_name, $prop_value) { $this->elem[$prop_name] = $prop_value; return true; } } // Here we overload the OO object overload('OO'); $o = new OO; print "\$o->a: $o->a\n"; // print: $o->a: print "\$o->b: $o->b\n"; // print: $o->b: 9 print "\$o->c: $o->c\n"; // print: $o->c: 42 print "\$o->d: $o->d\n"; // print: $o->d: // add a new item to the $elem array in OO $o->x = 56; // instantiate stdclass (it is built-in in PHP 4) // $val is not overloaded! $val = new stdclass; $val->prop = 555; // Set "a" to be an array with the $val object in it // But __set() will put this in the $elem array $o->a = array($val); var_dump($o->a[0]->prop); ?>

Warning

As this is an experimental extension, not all things work. There is no __call() support currently, you can only overload the get and set operations for properties. You cannot invoke the original overloading handlers of the class, and __set() only works to one level of property access.

Table of Contents
overload -- Enable property and method call overloading for a class

overload

(PHP 4 >= 4.2.0)

overload -- Enable property and method call overloading for a class

Description

void overload ( [string class_name])

The overload() function will enable property and method call overloading for a class identified by class_name. See an example in the introductory section of this part.

LXXVII. PDF functions

Introduction

The PDF functions in PHP can create PDF files using the PDFlib library created by Thomas Merz.

The documentation in this section is only meant to be an overview of the available functions in the PDFlib library and should not be considered an exhaustive reference. Please consult the documentation included in the source distribution of PDFlib for the full and detailed explanation of each function here. It provides a very good overview of what PDFlib is capable of doing and contains the most up-to-date documentation of all functions.

All of the functions in PDFlib and the PHP module have identical function names and parameters. You will need to understand some of the basic concepts of PDF and PostScript to efficiently use this extension. All lengths and coordinates are measured in PostScript points. There are generally 72 PostScript points to an inch, but this depends on the output resolution. Please see the PDFlib documentation included with the source distribution of PDFlib for a more thorough explanation of the coordinate system used.

Please note that most of the PDF functions require a pdf object as its first parameter. Please see the examples below for more information.

Requirements

PDFlib is available for download at http://www.pdflib.com/pdflib/index.html, but requires that you purchase a license for commercial use. The JPEG and TIFF libraries are required to compile this extension.

PDFlib 3.x Installation Hints

When using version 3.x of PDFlib, you should configure PDFlib with the option --enable-shared-pdflib.

Issues with older versions of PDFlib

Any version of PHP 4 after March 9, 2000 does not support versions of PDFlib older than 3.0.

PDFlib 3.0 or greater is supported by PHP 3.0.19 and later.

Installation

Please see the PDFlib installation section for more information about compiling PDF support into PHP.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Confusion with old PDFlib versions

Starting with PHP 4.0.5, the PHP extension for PDFlib is officially supported by PDFlib GmbH. This means that all the functions described in the PDFlib manual (V3.00 or greater) are supported by PHP 4 with exactly the same meaning and the same parameters. Only the return values may differ from the PDFlib manual, because the PHP convention of returning FALSE was adopted. For compatibility reasons, this binding for PDFlib still supports the old functions, but they should be replaced by their new versions. PDFlib GmbH will not support any problems arising from the use of these deprecated functions.

Table 1. Deprecated functions and their replacements

Old function	Replacement
pdf_put_image()	Not needed anymore.
pdf_execute_image()	Not needed anymore.
pdf_get_annotation()	pdf_get_bookmark() using the same parameters.
pdf_get_font()	pdf_get_value() passing `"font"` as the second parameter.
pdf_get_fontsize()	pdf_get_value() passing `"fontsize"` as the second parameter.
pdf_get_fontname()	pdf_get_parameter() passing `"fontname"` as the second parameter.
pdf_set_info_creator()	pdf_set_info() passing `"Creator"` as the second parameter.
pdf_set_info_title()	pdf_set_info() passing `"Title"` as the second parameter.
pdf_set_info_subject()	pdf_set_info() passing `"Subject"` as the second parameter.
pdf_set_info_author()	pdf_set_info() passing `"Author"` as the second parameter.
pdf_set_info_keywords()	pdf_set_info() passing `"Keywords"` as the second parameter.
pdf_set_leading()	pdf_set_value() passing `"leading"` as the second parameter.
pdf_set_text_rendering()	pdf_set_value() passing `"textrendering"` as the second parameter.
pdf_set_text_rise()	pdf_set_value() passing `"textrise"` as the second parameter.
pdf_set_horiz_scaling()	pdf_set_value() passing `"horizscaling"` as the second parameter.
pdf_set_text_matrix()	Not available anymore
pdf_set_char_spacing()	pdf_set_value() passing `"charspacing"` as the second parameter.
pdf_set_word_spacing()	pdf_set_value() passing `"wordspacing"` as the second parameter.
pdf_set_transition()	pdf_set_parameter() passing `"transition"` as the second parameter.
pdf_open()	pdf_new() plus an subsequent call of pdf_open_file()
pdf_set_font()	pdf_findfont() plus an subsequent call of pdf_setfont()
pdf_set_duration()	pdf_set_value() passing `"duration"` as the second parameter.
pdf_open_gif()	pdf_open_image_file() passing `"gif"` as the second parameter.
pdf_open_jpeg()	pdf_open_image_file() passing `"jpeg"` as the second parameter.
pdf_open_tiff()	pdf_open_image_file() passing `"tiff"` as the second parameter.
pdf_open_png()	pdf_open_image_file() passing `"png"` as the second parameter.
pdf_get_image_width()	pdf_get_value() passing `"imagewidth"` as the second parameter and the image as the third parameter.
pdf_get_image_height()	pdf_get_value() passing `"imageheight"` as the second parameter and the image as the third parameter.

Examples

Most of the functions are fairly easy to use. The most difficult part is probably creating your first PDF document. The following example should help to get you started. It creates test.pdf with one page. The page contains the text "Times Roman outlined" in an outlined, 30pt font. The text is also underlined.

Example 1. Creating a PDF document with PDFlib
<?php $pdf = pdf_new(); pdf_open_file($pdf, "test.pdf"); pdf_set_info($pdf, "Author", "Uwe Steinmann"); pdf_set_info($pdf, "Title", "Test for PHP wrapper of PDFlib 2.0"); pdf_set_info($pdf, "Creator", "See Author"); pdf_set_info($pdf, "Subject", "Testing"); pdf_begin_page($pdf, 595, 842); pdf_add_outline($pdf, "Page 1"); pdf_set_font($pdf, "Times-Roman", 30, "host"); pdf_set_value($pdf, "textrendering", 1); pdf_show_xy($pdf, "Times Roman outlined", 50, 750); pdf_moveto($pdf, 50, 740); pdf_lineto($pdf, 330, 740); pdf_stroke($pdf); pdf_end_page($pdf); pdf_close($pdf); pdf_delete($pdf); echo "<A HREF=getpdf.php>finished</A>"; ?>
The script getpdf.php just returns the pdf document.
<?php $len = filesize($filename); header("Content-type: application/pdf"); header("Content-Length: $len"); header("Content-Disposition: inline; filename=foo.pdf"); readfile($filename); ?>

The PDFlib distribution contains a more complex example which creates a page with an analog clock. Here we use the in-memory creation feature of PDFlib to alleviate the need to use temporary files. The example was converted to PHP from the PDFlib example. (The same example is available in the CLibPDF documentation.)

Example 2. pdfclock example from PDFlib distribution
<?php $radius = 200; $margin = 20; $pagecount = 10; $pdf = pdf_new(); if (!pdf_open_file($pdf, "")) { print error; exit; }; pdf_set_parameter($pdf, "warning", "true"); pdf_set_info($pdf, "Creator", "pdf_clock.php"); pdf_set_info($pdf, "Author", "Uwe Steinmann"); pdf_set_info($pdf, "Title", "Analog Clock"); while($pagecount-- > 0) { pdf_begin_page($pdf, 2 * ($radius + $margin), 2 * ($radius + $margin)); pdf_set_parameter($pdf, "transition", "wipe"); pdf_set_value($pdf, "duration", 0.5); pdf_translate($pdf, $radius + $margin, $radius + $margin); pdf_save($pdf); pdf_setrgbcolor($pdf, 0.0, 0.0, 1.0); /* minute strokes */ pdf_setlinewidth($pdf, 2.0); for ($alpha = 0; $alpha < 360; $alpha += 6) { pdf_rotate($pdf, 6.0); pdf_moveto($pdf, $radius, 0.0); pdf_lineto($pdf, $radius-$margin/3, 0.0); pdf_stroke($pdf); } pdf_restore($pdf); pdf_save($pdf); /* 5 minute strokes */ pdf_setlinewidth($pdf, 3.0); for ($alpha = 0; $alpha < 360; $alpha += 30) { pdf_rotate($pdf, 30.0); pdf_moveto($pdf, $radius, 0.0); pdf_lineto($pdf, $radius-$margin, 0.0); pdf_stroke($pdf); } $ltime = getdate(); /* draw hour hand */ pdf_save($pdf); pdf_rotate($pdf,-(($ltime['minutes']/60.0)+$ltime['hours']-3.0)*30.0); pdf_moveto($pdf, -$radius/10, -$radius/20); pdf_lineto($pdf, $radius/2, 0.0); pdf_lineto($pdf, -$radius/10, $radius/20); pdf_closepath($pdf); pdf_fill($pdf); pdf_restore($pdf); /* draw minute hand */ pdf_save($pdf); pdf_rotate($pdf,-(($ltime['seconds']/60.0)+$ltime['minutes']-15.0)*6.0); pdf_moveto($pdf, -$radius/10, -$radius/20); pdf_lineto($pdf, $radius * 0.8, 0.0); pdf_lineto($pdf, -$radius/10, $radius/20); pdf_closepath($pdf); pdf_fill($pdf); pdf_restore($pdf); /* draw second hand */ pdf_setrgbcolor($pdf, 1.0, 0.0, 0.0); pdf_setlinewidth($pdf, 2); pdf_save($pdf); pdf_rotate($pdf, -(($ltime['seconds'] - 15.0) * 6.0)); pdf_moveto($pdf, -$radius/5, 0.0); pdf_lineto($pdf, $radius, 0.0); pdf_stroke($pdf); pdf_restore($pdf); /* draw little circle at center */ pdf_circle($pdf, 0, 0, $radius/30); pdf_fill($pdf); pdf_restore($pdf); pdf_end_page($pdf); # to see some difference sleep(1); } pdf_close($pdf); $buf = pdf_get_buffer($pdf); $len = strlen($buf); header("Content-type: application/pdf"); header("Content-Length: $len"); header("Content-Disposition: inline; filename=foo.pdf"); print $buf; pdf_delete($pdf); ?>

pdf_add_annotation

pdf_add_annotation -- Deprecated: Adds annotation

int pdf_add_note ( int pdf object, float llx, float lly, float urx, float ury, string contents, string title, string icon, int open)

Add a note annotation. icon is one of of "comment, "insert", "note", "paragraph", "newparagraph", "key", or "help".

(PHP 3>= 3.0.6, PHP 4 )

pdf_begin_page -- Starts new page

Description

void pdf_begin_page ( int pdf object, float width, float height)

Add a new page to the document. The width and height are specified in points, which are 1/72 of an inch.

Table 1. Common Page Sizes in Points

name	size
A0	2380✗3368
A1	1684✗2380
A2	1190✗1684
A3	842✗1190
A4	595✗842
A5	421✗595
A6	297✗421
B5	501✗709
letter (8.5"✗11")	612✗792
legal (8.5"✗14")	612✗1008
ledger (17"✗11")	1224✗792
11"✗17"	792✗1224

pdf_endpath

pdf_endpath -- Deprecated: Ends current path

int pdf_findfont ( int pdf object, string fontname, string encoding, int embed)

Prepare a font for later use with pdf_setfont(). The metrics will be loaded, and if embed is nonzero, the font file will be checked, but not yet used. encoding is one of "builtin", "macroman", "winansi", "host", or a user-defined encoding name, or the name of a CMap.

pdf_findfont() returns a font handle or FALSE on error.

Example 1. pdf_findfont() example
<?php $font = pdf_findfont($pdf, "Times New Roman", "winansi", 1); if ($font) { pdf_setfont($pdf, $font, 10); } ?>

pdf_get_buffer

(PHP 4 >= 4.0.5)

The following example shows how to create a pdf document in memory and how to output it correctly.
Example 1. Creating a PDF document in memory
<?php $pdf = pdf_new(); pdf_open_file($pdf); pdf_begin_page($pdf, 595, 842); pdf_set_font($pdf, "Times-Roman", 30, "host"); pdf_set_value($pdf, "textrendering", 1); pdf_show_xy($pdf, "A PDF document created in memory!", 50, 750); pdf_end_page($pdf); pdf_close($pdf); $data = pdf_get_buffer($pdf); header("Content-type: application/pdf"); header("Content-disposition: inline; filename=test.pdf"); header("Content-length: " . strlen($data)); echo $data; ?>

pdf_open_jpeg -- Deprecated: Opens a JPEG image

int pdf_open_pdi ( int pdf object, string filename, string stringparam, int intparam)

Open an existing PDF document for later use.

pdf_open_png

pdf_open_png -- Deprecated: Opens a PNG image

Description

Deprecated.

See pdf_open_image().

pdf_open_tiff

(PHP 4 )

pdf_open_tiff -- Deprecated: Opens a TIFF image

Description

int pdf_open_tiff ( int PDF-document, string filename)

Deprecated.

pdf_open

pdf_open -- Deprecated: Open a new pdf object

void pdf_set_border_style ( int pdf object, string style, float width)

Set the border style for all kinds of annotations. style is "solid" or "dashed".

pdf_set_char_spacing

pdf_set_char_spacing -- Deprecated: Sets character spacing

Description

Deprecated.

See also pdf_set_value(),

pdf_set_duration

pdf_set_duration -- Deprecated: Sets duration between pages

Description

Deprecated.

See pdf_set_value().

pdf_set_font

pdf_set_font -- Deprecated: Selects a font face and size

Description

Deprecated. You should use pdf_findfont() plus pdf_setfont() instead.

See pdf_findfont(), pdf_setfont().

pdf_set_horiz_scaling

(PHP 3>= 3.0.6, PHP 4 )

pdf_set_horiz_scaling -- Sets horizontal scaling of text

Description

void pdf_set_horiz_scaling ( int pdf object, float scale)

void pdf_set_info ( int pdf object, string key, string value)

Fill document information field key with value. key is one of "Subject", "Title", "Creator", "Author", "Keywords", or a user-defined key.

pdf_set_leading

pdf_set_leading -- Deprecated: Sets distance between text lines

Description

Deprecated.

See also pdf_set_value(),

pdf_set_parameter

(PHP 4 )

pdf_set_parameter -- Sets certain parameters

Description

void pdf_set_parameter ( int pdf object, string key, string value)

Set some PDFlib parameter with string type.

pdf_set_text_matrix

pdf_set_text_matrix -- Deprecated: Sets the text matrix

Description

See pdf_set_paramter().

pdf_set_text_pos

(PHP 3>= 3.0.6, PHP 4 )

(PHP 4 >= 4.0.1)

pdf_set_value -- Sets certain numerical value

Description

void pdf_set_value ( int pdf object, string key, float value)

Set the value of some PDFlib parameter with float type.

pdf_set_word_spacing

pdf_set_word_spacing -- Depriciated: Sets spacing between words

Description

Deprecated.

See also pdf_set_value(),

pdf_setcolor

(PHP 4 >= 4.0.5)

pdf_setcolor -- Sets fill and stroke color

Description

void pdf_setcolor ( int pdf object, string type, string colorspace, float c1 [, float c2 [, float c3 [, float c4]]])

Set the current color space and color. The parameter type can be "fill", "stroke", or "both" to specify that the color is set for filling, stroking or both filling and stroking. The parameter colorspace can be gray, rgb, cmyk, spot or pattern. The parameters c1, c2, c3 and c4 represent the color components for the color space specified by colorspace. Except as otherwise noted, the color components are floating-point values that range from 0 to 1.

For gray only c1 is used.

For rgb parameters c1, c2, and c3 specify the red, green and blue values respectively.

// Set fill and stroke colors to white.
pdf_setcolor($pdf, "both", "rgb", 1, 1, 1);

For cmyk, parameters c1, c2, c3, and c4 are the cyan, magenta, yellow and black values, respectively.

// Set fill and stroke colors to white.
pdf_setcolor($pdf, "both", "cmyk", 0, 0, 0, 1);

void pdf_setgray_fill ( int pdf object, float gray)

Set the current fill color to a gray value between 0 and 1 inclusive.

Note: PDFlib V4.0: Deprecated, use pdf_setcolor() instead.

pdf_setgray_stroke

(PHP 3>= 3.0.6, PHP 4 )

pdf_setgray_stroke -- Sets drawing color to gray value

Description

void pdf_setgray_stroke ( int pdf object, float gray)

Set the current stroke color to a gray value between 0 and 1 inclusive

Note: PDFlib V4.0: Deprecated, use pdf_setcolor() instead.

pdf_setgray

(PHP 3>= 3.0.6, PHP 4 )

pdf_setgray -- Sets drawing and filling color to gray value

Description

void pdf_setgray ( int pdf object, float gray)

Set the current fill and stroke color.

Note: PDFlib V4.0: Deprecated, use pdf_setcolor() instead.

Note: PDFlib V4.0: Deprecated, use pdf_setcolor() instead.

pdf_setrgbcolor_stroke

(PHP 3>= 3.0.6, PHP 4 )

pdf_setrgbcolor_stroke -- Sets drawing color to rgb color value

Description

void pdf_setrgbcolor_stroke ( int pdf object, float red value, float green value, float blue value)

Set the current stroke color to the supplied RGB values.

Note: PDFlib V4.0: Deprecated, use pdf_setcolor() instead.

pdf_setrgbcolor

(PHP 3>= 3.0.6, PHP 4 )

pdf_setrgbcolor -- Sets drawing and filling color to rgb color value

Description

void pdf_setrgbcolor ( int pdf object, float red value, float green value, float blue value)

Set the current fill and stroke color to the supplied RGB values.

Note: PDFlib V4.0: Deprecated, use pdf_setcolor() instead.

pdf_show_boxed

(PHP 4 )

pdf_show_boxed -- Output text in a box

Description

int pdf_show_boxed ( int pdf object, string text, float left, float top, float width, float height, string hmode [, string feature])

float pdf_stringwidth ( int pdf object, string text [, int font [, float size]])

Returns the width of text using the last font set by pdf_setfont(). If the optional parameters font and size are specified, the width will be calculated using that font and size instead. Please note that font is a font handle returned by pdf_findfont().

Note: Both the font and size parameters must used together.

See Also: pdf_setfont() and pdf_findfont().

pdf_stroke

(PHP 3>= 3.0.6, PHP 4 )

pdf_stroke -- Draws line along path

Description

void pdf_stroke ( int pdf object)

Stroke the path with the current color and line width, and clear it.

pdf_translate

(PHP 3>= 3.0.6, PHP 4 )

pdf_translate -- Sets origin of coordinate system

Description

void pdf_translate ( int pdf object, float tx, float ty)

Translate the origin of the coordinate system.

LXXVIII. Verisign Payflow Pro functions

Introduction

This extension allows you to process credit cards and other financial transactions using Verisign Payment Services, formerly known as Signio (http://www.verisign.com/products/payflow/pro/index.html).

When using these functions, you may omit calls to pfpro_init() and pfpro_cleanup() as this extension will do so automatically if required. However the functions are still available in case you are processing a number of transactions and require fine control over the library. You may perform any number of transactions using pfpro_process() between the two.

These functions were added in PHP 4.0.2.

Note: These functions only provide a link to Verisign Payment Services. Be sure to read the Payflow Pro Developers Guide for full details of the required parameters.

Requirements

You will require the appropriate SDK for your platform, which may be downloaded from within the manager interface once you have registered. If you are going to use this extension in an SSL-enabled webserver or with other SSL components (such as the CURL+SSL extension) you MUST get the beta SDK.

Once you have downloaded the SDK you should copy the files from the lib directory of the distribution. Copy the header file pfpro.h to /usr/local/include and the library file libpfpro.so to /usr/local/lib.

Installation

These functions are only available if PHP has been compiled with the --with-pfpro[=DIR] option.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Verisign Payflow Pro configuration options

Name	Default	Changeable
pfpro.defaulthost/PFPRO_VERSION < 3	"test.signio.com"	PHP_INI_ALL
pfpro.defaulthost	"test-payflow.verisign.com"	PHP_INI_ALL
pfpro.defaultport	"443"	PHP_INI_ALL
pfpro.defaulttimeout	"30"	PHP_INI_ALL
pfpro.proxyaddress	""	PHP_INI_ALL
pfpro.proxyport	""	PHP_INI_ALL
pfpro.proxylogon	""	PHP_INI_ALL
pfpro.proxypassword	""	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Table of Contents
pfpro_cleanup -- Shuts down the Payflow Pro library
pfpro_init -- Initialises the Payflow Pro library
pfpro_process_raw -- Process a raw transaction with Payflow Pro
pfpro_process -- Process a transaction with Payflow Pro
pfpro_version -- Returns the version of the Payflow Pro software

pfpro_process_raw() processes a raw transaction string with Payflow Pro. You should really use pfpro_process() instead, as the encoding rules of these transactions are non-standard.

The first parameter in this case is a string containing the raw transaction request. All other parameters are the same as with pfpro_process(). The return value is a string containing the raw response.

Note: Be sure to read the Payflow Pro Developers Guide for full details of the required parameters and encoding rules. You would be well advised to use pfpro_process() instead.

Example 1. Payflow Pro raw example

<?php

pfpro_init();

$response = pfpro_process_raw("USER=mylogin&PWD[5]=m&ndy&PARTNER=VeriSign&TRXTYPE=S&TENDER=C&AMT=1.50&ACCT=4111111111111111&EXPDATE=0904");

if (!$response) {
  die("Couldn't establish link to Verisign.\n");
}

echo "Verisign raw response was ".$response;

pfpro_cleanup();

?>

pfpro_process

(PHP 4 >= 4.0.2)

pfpro_process -- Process a transaction with Payflow Pro

Description

array pfpro_process ( array parameters [, string address [, int port [, int timeout [, string proxy address [, int proxy port [, string proxy logon [, string proxy password]]]]]]])

Returns: An associative array containing the response

pfpro_process() processes a transaction with Payflow Pro. The first parameter is an associative array containing keys and values that will be encoded and passed to the processor.

The second parameter is optional and specifies the host to connect to. By default this is "test.signio.com", so you will certainly want to change this to "connect.signio.com" in order to process live transactions.

The third parameter specifies the port to connect on. It defaults to 443, the standard SSL port.

The fourth parameter specifies the timeout to be used, in seconds. This defaults to 30 seconds. Note that this timeout appears to only begin once a link to the processor has been established and so your script could potentially continue for a very long time in the event of DNS or network problems.

The fifth parameter, if required, specifies the hostname of your SSL proxy. The sixth parameter specifies the port to use.

The seventh and eighth parameters specify the logon identity and password to use on the proxy.

The function returns an associative array of the keys and values in the response.

Note: Be sure to read the Payflow Pro Developers Guide for full details of the required parameters.

Example 1. Payflow Pro example

<?php

pfpro_init();

$transaction = array('USER'    => 'mylogin',
                     'PWD'     => 'mypassword',
                     'PARTNER' => 'VeriSign',
                     'TRXTYPE' => 'S',
                     'TENDER'  => 'C',
                     'AMT'     => 1.50,
                     'ACCT'    => '4111111111111111',
                     'EXPDATE' => '0904'
                    );

$response = pfpro_process($transaction);

if (!$response) {
  die("Couldn't establish link to Verisign.\n");
}

echo "Verisign response code was ".$response['RESULT'];
echo ", which means: ".$response['RESPMSG']."\n";

echo "\nThe transaction request: ";
print_r($transaction);

echo "\nThe response: ";
print_r($response);

pfpro_cleanup();

?>

pfpro_version

(PHP 4 >= 4.0.2)

pfpro_version -- Returns the version of the Payflow Pro software

Description

string pfpro_version ( void)

pfpro_version() returns the version string of the Payflow Pro library. At the time of writing, this was L211.

LXXIX. PHP Options&Information

Introduction

This functions enable you to get a lot of information about PHP itself, e.g. runtime configuration, loaded extensions, version and much more. You'll also find functions to set options for your running PHP. The probably best known function of PHP - phpinfo() - can be found here.

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. PHP Options/Inf Configuration Options

Name	Default	Changeable
assert.active	"1"	PHP_INI_ALL
assert.bail	"0"	PHP_INI_ALL
assert.warning	"1"	PHP_INI_ALL
assert.callback	NULL	PHP_INI_ALL
assert.quiet_eval	"0"	PHP_INI_ALL
enable_dl	"1"	PHP_INI_SYSTEM
max_execution_time	"30"	PHP_INI_ALL
magic_quotes_gpc	"1"	PHP_INI_PERDIR\|PHP_INI_SYSTEM
magic_quotes_runtime	"0"	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Here is a short explanation of the configuration directives.

assert.active boolean

Enable assert() evaluation.

assert.bail boolean

Terminate script execution on failed assertions.

assert.warning boolean

Issue a PHP warning for each failed assertion.

assert.callback string

user function to call on failed assertions

assert.quiet_eval boolean

Use the current setting of error_reporting() during assertion expression evaluation. If enabled, no errors are shown (implicit error_reporting(0)) while evaluation. If disabled, errors are shown according to the settings of error_reporting()

enable_dl boolean

This directive is really only useful in the Apache module version of PHP. You can turn dynamic loading of PHP extensions with dl() on and off per virtual server or per directory.

The main reason for turning dynamic loading off is security. With dynamic loading, it's possible to ignore all the safe_mode and open_basedir restrictions.

The default is to allow dynamic loading, except when using safe-mode. In safe-mode, it's always imposible to use dl().

max_execution_time integer

This sets the maximum time in seconds a script is allowed to run before it is terminated by the parser. This helps prevent poorly written scripts from tying up the server. The default setting is 30.

The maximum execution time is not affected by system calls, the sleep() function, etc. Please see the set_time_limit() function for more details.

magic_quotes_gpc boolean

Sets the magic_quotes state for GPC (Get/Post/Cookie) operations. When magic_quotes are on, all ' (single-quote), " (double quote), \ (backslash) and NUL's are escaped with a backslash automatically. If magic_quotes_sybase is also on, a single-quote is escaped with a single-quote instead of a backslash.

magic_quotes_runtime boolean

If magic_quotes_runtime is enabled, most functions that return data from any sort of external source including databases and text files will have quotes escaped with a backslash. If magic_quotes_sybase is also on, a single-quote is escaped with a single-quote instead of a backslash.

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are always available as part of the PHP core.

Table 2. Pre-defined phpcredits() constants

Constant	Description
CREDITS_ALL	All the credits, equivalent to using: CREDITS_DOCS + CREDITS_GENERAL + CREDITS_GROUP + CREDITS_MODULES + CREDITS_FULLPAGE. It generates a complete stand-alone HTML page with the appropriate tags.
CREDITS_DOCS	The credits for the documentation team
CREDITS_FULLPAGE	Usually used in combination with the other flags. Indicates that the a complete stand-alone HTML page needs to be printed including the information indicated by the other flags.
CREDITS_GENERAL	General credits: Language design and concept, PHP 4.0 authors and SAPI module.
CREDITS_GROUP	A list of the core developers
CREDITS_MODULES	A list of the extension modules for PHP, and their authors
CREDITS_SAPI	A list of the server API modules for PHP, and their authors

Table 3. phpinfo() constants

Constant	Value	Description
INFO_GENERAL	1	The configuration line, `php.ini` location, build date, Web Server, System and more.
INFO_CREDITS	2	PHP 4 Credits. See also phpcredits().
INFO_CONFIGURATION	4	Current Local and Master values for php directives. See also ini_get().
INFO_MODULES	8	Loaded modules and their respective settings.
INFO_ENVIRONMENT	16	Environment Variable information that's also available in `$_ENV`.
INFO_VARIABLES	32	Shows all predefined variables from EGPCS (Environment, GET, POST, Cookie, Server).
INFO_LICENSE	64	PHP License information. See also the license faq.
INFO_ALL	-1	Shows all of the above. This is the default value.

ASSERT_ACTIVE (integer)
ASSERT_CALLBACK (integer)
ASSERT_BAIL (integer)
ASSERT_WARNING (integer)
ASSERT_QUIET_EVAL (integer)

Table of Contents
assert_options -- Set/get the various assert flags
assert -- Checks if assertion is FALSE
dl -- Loads a PHP extension at runtime
extension_loaded -- Find out whether an extension is loaded
get_cfg_var -- Gets the value of a PHP configuration option
get_current_user -- Gets the name of the owner of the current PHP script
get_defined_constants -- Returns an associative array with the names of all the constants and their values
get_extension_funcs -- Returns an array with the names of the functions of a module
get_included_files -- Returns an array with the names of included or required files
get_loaded_extensions -- Returns an array with the names of all modules compiled and loaded
get_magic_quotes_gpc -- Gets the current active configuration setting of magic quotes gpc
get_magic_quotes_runtime -- Gets the current active configuration setting of magic_quotes_runtime
get_required_files -- Returns an array with the names of included or required files
getenv -- Gets the value of an environment variable
getlastmod -- Gets time of last page modification
getmygid -- Get PHP script owner's GID
getmyinode -- Gets the inode of the current script
getmypid -- Gets PHP's process ID
getmyuid -- Gets PHP script owner's UID
getopt -- Gets options from the command line argument list
getrusage -- Gets the current resource usages
ini_alter -- Changes the value of a configuration option
ini_get_all -- Gets all configuration options
ini_get -- Gets the value of a configuration option
ini_restore -- Restores the value of a configuration option
ini_set -- Sets the value of a configuration option
php_logo_guid -- Gets the logo guid
php_sapi_name -- Returns the type of interface between web server and PHP
php_uname -- Returns information about the operating system PHP was built on
phpcredits -- Prints out the credits for PHP
phpinfo -- Outputs lots of PHP information
phpversion -- Gets the current PHP version
putenv -- Sets the value of an environment variable
set_magic_quotes_runtime -- Sets the current active configuration setting of magic_quotes_runtime
set_time_limit -- Limits the maximum execution time
version_compare -- Compares two "PHP-standardized" version number strings
zend_logo_guid -- Gets the zend guid
zend_version -- Gets the version of the current Zend engine

assert_options

(PHP 4 )

assert_options -- Set/get the various assert flags

Description

mixed assert_options ( int what [, mixed value])

Using assert_options() you may set the various assert() control options or just query their current settings.

Table 1. Assert Options

option	ini-parameter	default	description
ASSERT_ACTIVE	assert.active	1	enable assert() evaluation
ASSERT_WARNING	assert.warning	1	issue a PHP warning for each failed assertion
ASSERT_BAIL	assert.bail	0	terminate execution on failed assertions
ASSERT_QUIET_EVAL	assert.quiet_eval	0	disable error_reporting during assertion expression evaluation
ASSERT_CALLBACK	assert_callback	(`NULL`)	user function to call on failed assertions

assert_options() will return the original setting of any option or FALSE on errors.

assert

(PHP 4 )

assert -- Checks if assertion is FALSE

Description

int assert ( string|bool assertion)

assert() will check the given assertion and take appropriate action if its result is FALSE.

If the assertion is given as a string it will be evaluated as PHP code by assert(). The advantages of a string assertion are less overhead when assertion checking is off and messages containing the assertion expression when an assertion fails.

Assertions should be used as a debugging feature only. You may use them for sanity-checks that test for conditions that should always be TRUE and that indicate some programming errors if not or to check for the presence of certain features like extension functions or certain system limits and features.

Assertions should not be used for normal runtime operations like input parameter checks. As a rule of thumb your code should always be able to work correctly if assertion checking is not activated.

The behavior of assert() may be configured by assert_options() or by .ini-settings described in that functions manual page.

The assert_options() function and/or ASSERT_CALLBACK configuration directive allow a callback function to be set to handle failed assertions.

assert() callbacks are particularly useful for building automated test suites because they allow you to easily capture the code passed to the assertion, along with information on where the assertion was made. While this information can be captured via other methods, using assertions makes it much faster and easier!

The callback function should accept three arguments. The first argument will contain the file the assertion failed in. The second argument will contain the line the assertion failed on and the third argument will contain the expression that failed (if any - literal values such as 1 or "two" will not be passed via this argument)

Example 1. Handle a failed assertion with a custom handler
<?php // Active assert and make it quiet assert_options (ASSERT_ACTIVE, 1); assert_options (ASSERT_WARNING, 0); assert_options (ASSERT_QUIET_EVAL, 1); // Create a handler function function my_assert_handler ($file, $line, $code) { echo "<hr>Assertion Failed: File '$file'<br> Line '$line'<br> Code '$code'<br><hr>"; } // Set up the callback assert_options (ASSERT_CALLBACK, 'my_assert_handler'); // Make an assertion that should fail assert ('mysql_query ("")'); ?>

dl

(PHP 3, PHP 4 )

dl -- Loads a PHP extension at runtime

Description

bool dl ( string library)

Loads the PHP extension given by the parameter library. The library parameter is only the filename of the extension to load which also depends on your platform. For example, the sockets extension (if compiled as a shared module, not the default!) would be called sockets.so on unix platforms whereas it is called php_sockets.dll on the windows platform.

Returns TRUE on success or FALSE on failure. If the functionality of loading modules is not available (see Note) or has been disabled (either by turning it off enable_dl or by enabling safe_mode in php.ini) an E_ERROR is emitted and execution is stopped. If dl() fails because the specified library couldn't be loaded, in addition to FALSE an E_WARNING message is emitted.

Use extension_loaded() to test whether a given extension is already available or not. This works on both built-in extensions and dynamically loaded ones (either through php.ini or dl()).

Example:
if (!extension_loaded('gd')) { if (!dl('gd.so')) { exit; } }

The directory where the extension is loaded from depends on your platform:

Windows - If not explicitly set in the php.ini, the extension is loaded from c:\php4\extensions\ by default.

Unix - If not explicitly set in the php.ini, the default extension directory depends on

whether PHP has been built with --enable-debug or not
whether PHP has been built with (experimental) ZTS (Zend Thread Safety) support or not
the current internal ZEND_MODULE_API_NO (Zend internal module API number, which is basically the date on which a major module API change happened, e.g. 20010901)

Taking into account the above, the directory then defaults to <php-install-directory>/lib/php/extension/<debug-or-not>-<zts-or-not>-ZEND_MODULE_API_NO, e.g. /usr/local/php/lib/php/extensions/debug-non-zts-20010901 or /usr/local/php/lib/php/extensions/no-debug-zts-20010901.

Note: dl() is not supported in multithreaded Web servers. Use the extensions statement in your php.ini when operating under such an environment. However, the CGI and CLI build are not affected !

Note: dl() is case sensitive on unix platforms.

extension_loaded

(PHP 3>= 3.0.10, PHP 4 )

extension_loaded -- Find out whether an extension is loaded

Description

bool extension_loaded ( string name)

Returns TRUE if the extension identified by name is loaded, FALSE otherwise.

Example:
if (!extension_loaded('gd')) { if (!dl('gd.so')) { exit; } }

You can see the names of various extensions by using phpinfo() or if you're usnig the CGI or CLI version of PHP you can use the -m switch to list all available extensions:
$ php -m [PHP Modules] xml tokenizer standard sockets session posix pcre overload mysql mbstring ctype [Zend Modules]

Note: extension_loaded() uses the internal extension name to test whether a certain extension is available or not. Most internal extension names are written in lower case but there may be extension available which also use uppercase letters. Be warned that this function compares case sensitive !

get_cfg_var

(PHP 3, PHP 4 )

get_cfg_var -- Gets the value of a PHP configuration option

Description

string get_cfg_var ( string varname)

Returns the current value of the PHP configuration variable specified by varname, or FALSE if an error occurs.

It will not return configuration information set when the PHP was compiled, or read from an Apache configuration file (using the php3_configuration_option directives).

To check whether the system is using a configuration file, try retrieving the value of the cfg_file_path configuration setting. If this is available, a configuration file is being used.

get_current_user

(PHP 3, PHP 4 )

get_current_user -- Gets the name of the owner of the current PHP script

Description

string get_current_user ( void)

Returns the name of the owner of the current PHP script.

get_defined_constants

(PHP 4 >= 4.1.0)

get_defined_constants -- Returns an associative array with the names of all the constants and their values

Description

array get_defined_constants ( void)

This function returns the names and values of all the constants currently defined. This includes those created by extensions as well as those created with the define() function.

For example the line below

print_r (get_defined_constants());

will print a list like:

Array
(
    [E_ERROR] => 1
    [E_WARNING] => 2
    [E_PARSE] => 4
    [E_NOTICE] => 8
    [E_CORE_ERROR] => 16
    [E_CORE_WARNING] => 32
    [E_COMPILE_ERROR] => 64
    [E_COMPILE_WARNING] => 128
    [E_USER_ERROR] => 256
    [E_USER_WARNING] => 512
    [E_USER_NOTICE] => 1024
    [E_ALL] => 2047
    [TRUE] => 1
)

get_extension_funcs

(PHP 4 )

get_extension_funcs -- Returns an array with the names of the functions of a module

Description

array get_extension_funcs ( string module_name)

This function returns the names of all the functions defined in the module indicated by module_name.

For example the lines below

print_r (get_extension_funcs ("xml"));
print_r (get_extension_funcs ("gd"));

will print a list of the functions in the modules xml and gd respectively.

get_included_files

(PHP 4 )

get_included_files -- Returns an array with the names of included or required files

Description

array get_included_files ( void)

Returns an array of the names of all files that have been included using include(), include_once(), require() or require_once().

Files that are included or required multiple times only show up once in the returned array.

Note: Files included using the auto_prepend_file configuration directive are not included in the returned array.

Example 1. get_included_files() Example
<?php include("test1.php"); include_once("test2.php"); require("test3.php"); require_once("test4.php"); $included_files = get_included_files(); foreach($included_files as $filename) { echo "$filename\n"; } ?>
will generate the following output:

test1.php
test2.php
test3.php
test4.php

Note: In PHP 4.0.1pl2 and previous versions get_included_files() assumed that the required files ended in the extension .php; other extensions would not be returned. The array returned by get_included_files() was an associative array and only listed files included by include() and include_once().

get_loaded_extensions

(PHP 4 )

get_loaded_extensions -- Returns an array with the names of all modules compiled and loaded

Description

array get_loaded_extensions ( void)

This function returns the names of all the modules compiled and loaded in the PHP interpreter.

For example the line below

print_r (get_loaded_extensions());

will print a list like:

Array
(
   [0] => xml
   [1] => wddx
   [2] => standard
   [3] => session
   [4] => posix
   [5] => pgsql
   [6] => pcre
   [7] => gd
   [8] => ftp
   [9] => db
   [10] => calendar
   [11] => bcmath
)

In PHP 4.0.1pl2 and previous versions get_required_files() assumed that the required files ended in the extension .php, other extensions would not be returned. The array returned by get_required_files() was an associative array and only listed files included by require() and require_once().

getenv

(PHP 3, PHP 4 )

getenv -- Gets the value of an environment variable

Description

string getenv ( string varname)

Returns the value of the environment variable varname, or FALSE on an error.

$ip = getenv ("REMOTE_ADDR"); // get the ip number of the user

You can see a list of all the environmental variables by using phpinfo(). You can find out what many of them mean by taking a look at the CGI specification, specifically the page on environmental variables.

Note: This function does not work in ISAPI mode.

Note: This function is not implemented on Windows platforms.

getmypid

(PHP 3, PHP 4 )

getmypid -- Gets PHP's process ID

Description

int getmypid ( void)

Returns the current PHP process ID, or FALSE on error.

Warning

Process IDs are not unique, thus they are a weak entropy source. We recommend against relying on pids in security-dependent contexts.

getmyuid

(PHP 3, PHP 4 )

getmyuid -- Gets PHP script owner's UID

Description

int getmyuid ( void)

Returns the user ID of the current script, or FALSE on error.

getopt

(no version information, might be only in CVS)

getopt -- Gets options from the command line argument list

Description

string getopt ( string options)

Returns an associative array of option / argument pairs based on the options format specified in options, or FALSE on an error.

$options = getopt("f:hp:"); // parse the command line ($_GLOBALS['argv'])

The options parameter may contain the following elements: individual characters, and characters followed by a colon to indicate an option argument is to follow. For example, an option string x recognizes an option -x, and an option string x: recognizes an option and argument -x argument. It does not matter if an argument has leading white space.

This function will return an array of option / argument pairs. If an option does not have an argument, the value will be set to FALSE.

Note: This function requires that the register_argc_argv configuration option be enabled.

getrusage

(PHP 3>= 3.0.7, PHP 4 )

getrusage -- Gets the current resource usages

Description

array getrusage ( [int who])

This is an interface to getrusage(2). It returns an associative array containing the data returned from the system call. If who is 1, getrusage will be called with RUSAGE_CHILDREN.

All entries are accessible by using their documented field names.
Example 1. Getrusage Example
$dat = getrusage(); echo $dat["ru_nswap"]; # number of swaps echo $dat["ru_majflt"]; # number of page faults echo $dat["ru_utime.tv_sec"]; # user time used (seconds) echo $dat["ru_utime.tv_usec"]; # user time used (microseconds)
See your system's man page on getrusage(2) for more details.

ini_alter

(PHP 4 )

ini_alter -- Changes the value of a configuration option

Description

string ini_alter ( string varname, string newvalue)

Changes the value of a configuration option, returns FALSE on failure, and the previous value of the configuration option on success.

Note: This is an alias of ini_set()

Not all the available options can be changed using ini_set(). Below is a table with a list of all PHP options (as of PHP 4.2.0), indicating which ones can be changed/set and at what level.

Table 1. Configuration options

Name	Default	Changeable
com.allow_dcom	"0"	PHP_INI_SYSTEM
com.autoregister_typelib	"0"	PHP_INI_SYSTEM
com.autoregister_verbose	"0"	PHP_INI_SYSTEM
com.autoregister_casesensitive	"1"	PHP_INI_SYSTEM
com.typelib_file	""	PHP_INI_SYSTEM
crack.default_dictionary	NULL	PHP_INI_SYSTEM
exif.encode_unicode	"ISO-8859-15"	PHP_INI_ALL
exif.decode_unicode_motorola	"UCS-2BE"	PHP_INI_ALL
exif.decode_unicode_intel	"UCS-2LE"	PHP_INI_ALL
exif.encode_jis	""	PHP_INI_ALL
exif.decode_jis_motorola	"JIS"	PHP_INI_ALL
exif.decode_jis_intel	"JIS"	PHP_INI_ALL
fbsql.allow_persistent	"1"	PHP_INI_SYSTEM
fbsql.generate_warnings	"0"	PHP_INI_SYSTEM
fbsql.autocommit	"1"	PHP_INI_SYSTEM
fbsql.max_persistent	"-1"	PHP_INI_SYSTEM
fbsql.max_links	"128"	PHP_INI_SYSTEM
fbsql.max_connections	"128"	PHP_INI_SYSTEM
fbsql.max_results	"128"	PHP_INI_SYSTEM
fbsql.batchSize	"1000"	PHP_INI_SYSTEM
fbsql.default_host	NULL	PHP_INI_SYSTEM
fbsql.default_user	"_SYSTEM"	PHP_INI_SYSTEM
fbsql.default_password	""	PHP_INI_SYSTEM
fbsql.default_database	""	PHP_INI_SYSTEM
fbsql.default_database_password	""	PHP_INI_SYSTEM
hwapi.allow_persistent	"0"	PHP_INI_SYSTEM
hyerwave.allow_persistent	"0"	PHP_INI_SYSTEM
hyperwave.default_port	"418"	PHP_INI_ALL
iconv.input_encoding	ICONV_INPUT_ENCODING	PHP_INI_ALL
iconv.output_encoding	ICONV_OUTPUT_ENCODING	PHP_INI_ALL
iconv.internal_encoding	ICONV_INTERNAL_ENCODING	PHP_INI_ALL
ifx.allow_persistent	"1"	PHP_INI_SYSTEM
ifx.max_persistent	"-1"	PHP_INI_SYSTEM
ifx.max_links	"-1"	PHP_INI_SYSTEM
ifx.default_host	NULL	PHP_INI_SYSTEM
ifx.default_user	NULL	PHP_INI_SYSTEM
ifx.default_password	NULL	PHP_INI_SYSTEM
ifx.blobinfile	"1"	PHP_INI_ALL
ifx.textasvarchar	"0"	PHP_INI_ALL
ifx.byteasvarchar	"0"	PHP_INI_ALL
ifx.charasvarchar	"0"	PHP_INI_ALL
ifx.nullformat	"0"	PHP_INI_ALL
ingres.allow_persistent	"1"	PHP_INI_SYSTEM
ingres.max_persistent	"-1"	PHP_INI_SYSTEM
ingres.max_links	"-1"	PHP_INI_SYSTEM
ingres.default_database	NULL	PHP_INI_ALL
ingres.default_user	NULL	PHP_INI_ALL
ingres.default_password	NULL	PHP_INI_ALL
ibase.allow_persistent	"1"	PHP_INI_SYSTEM
ibase.max_persistent	"-1"	PHP_INI_SYSTEM
ibase.max_links	"-1"	PHP_INI_SYSTEM
ibase.default_user	NULL	PHP_INI_ALL
ibase.default_password	NULL	PHP_INI_ALL
ibase.timestampformat	"%m/%d/%Y%H:%M:%S"	PHP_INI_ALL
ibase.dateformat	"%m/%d/%Y"	PHP_INI_ALL
ibase.timeformat	"%H:%M:%S"	PHP_INI_ALL
java.class.path	NULL	PHP_INI_ALL
java.home	NULL	PHP_INI_ALL
java.library.path	NULL	PHP_INI_ALL
java.library	JAVALIB	PHP_INI_ALL
java.library	NULL	PHP_INI_ALL
ldap.max_links	"-1"	PHP_INI_SYSTEM
mbstring.detect_order	NULL	PHP_INI_ALL
mbstring.http_input	NULL	PHP_INI_ALL
mbstring.http_output	NULL	PHP_INI_ALL
mbstring.internal_encoding	NULL	PHP_INI_ALL
mbstring.substitute_character	NULL	PHP_INI_ALL
mbstring.func_overload	"0"	PHP_INI_SYSTEM
mcrypt.algorithms_dir	NULL	PHP_INI_ALL
mcrypt.modes_dir	NULL	PHP_INI_ALL
mime_magic.magicfile	"/usr/share/misc/magic.mime"	PHP_INI_SYSTEM
mssql.allow_persistent	"1"	PHP_INI_SYSTEM
mssql.max_persistent	"-1"	PHP_INI_SYSTEM
mssql.max_links	"-1"	PHP_INI_SYSTEM
mssql.max_procs	"25"	PHP_INI_ALL
mssql.min_error_severity	"10"	PHP_INI_ALL
mssql.min_message_severity	"10"	PHP_INI_ALL
mssql.compatability_mode	"0"	PHP_INI_ALL
mssql.connect_timeout	"5"	PHP_INI_ALL
mssql.timeout	"60"	PHP_INI_ALL
mssql.textsize	"-1"	PHP_INI_ALL
mssql.textlimit	"-1"	PHP_INI_ALL
mssql.batchsize	"0"	PHP_INI_ALL
mssql.datetimeconvert	"1"	PHP_INI_ALL
mysql.allow_persistent	"1"	PHP_INI_SYSTEM
mysql.max_persistent	"-1"	PHP_INI_SYSTEM
mysql.max_links	"-1"	PHP_INI_SYSTEM
mysql.default_host	NULL	PHP_INI_ALL
mysql.default_user	NULL	PHP_INI_ALL
mysql.default_password	NULL	PHP_INI_ALL
mysql.default_port	NULL	PHP_INI_ALL
mysql.default_socket	NULL	PHP_INI_ALL
ncurses.value	"42"	PHP_INI_ALL
ncurses.string	"foobar"	PHP_INI_ALL
odbc.allow_persistent	"1"	PHP_INI_SYSTEM
odbc.max_persistent	"-1"	PHP_INI_SYSTEM
odbc.max_links	"-1"	PHP_INI_SYSTEM
odbc.default_db	NULL	PHP_INI_ALL
odbc.default_user	NULL	PHP_INI_ALL
odbc.default_pw	NULL	PHP_INI_ALL
odbc.defaultlrl	"4096"	PHP_INI_ALL
odbc.defaultbinmode	"1"	PHP_INI_ALL
odbc.check_persistent	"1"	PHP_INI_SYSTEM
pfpro.defaulthost	"test.signio.com"
pfpro.defaulthost	"test-payflow.verisign.com"
pfpro.defaultport	"443"	PHP_INI_ALL
pfpro.defaulttimeout	"30"	PHP_INI_ALL
pfpro.proxyaddress	""	PHP_INI_ALL
pfpro.proxyport	""	PHP_INI_ALL
pfpro.proxylogon	""	PHP_INI_ALL
pfpro.proxypassword	""	PHP_INI_ALL
pgsql.allow_persistent	"1"	PHP_INI_SYSTEM
pgsql.max_persistent	"-1"	PHP_INI_SYSTEM
pgsql.max_links	"-1"	PHP_INI_SYSTEM
pgsql.auto_reset_persistent	"0"	PHP_INI_SYSTEM
pgsql.ignore_notice	"0"	PHP_INI_ALL
pgsql.log_notice	"0"	PHP_INI_ALL
session.save_path	"/tmp"	PHP_INI_ALL
session.name	"PHPSESSID"	PHP_INI_ALL
session.save_handler	"files"	PHP_INI_ALL
session.auto_start	"0"	PHP_INI_ALL
session.gc_probability	"1"	PHP_INI_ALL
session.gc_maxlifetime	"1440"	PHP_INI_ALL
session.serialize_handler	"php"	PHP_INI_ALL
session.cookie_lifetime	"0"	PHP_INI_ALL
session.cookie_path	"/"	PHP_INI_ALL
session.cookie_domain	""	PHP_INI_ALL
session.cookie_secure	""	PHP_INI_ALL
session.use_cookies	"1"	PHP_INI_ALL
session.use_only_cookies	"0"	PHP_INI_ALL
session.referer_check	""	PHP_INI_ALL
session.entropy_file	""	PHP_INI_ALL
session.entropy_length	"0"	PHP_INI_ALL
session.cache_limiter	"nocache"	PHP_INI_ALL
session.cache_expire	"180"	PHP_INI_ALL
session.use_trans_sid	"1"	PHP_INI_SYSTEM\|PHP_INI_PERDIR
session.encode_sources	"globals,track"	PHP_INI_ALL
extname.global_value	"42"	PHP_INI_ALL
extname.global_string	"foobar"	PHP_INI_ALL
assert.active	"1"	PHP_INI_ALL
assert.bail	"0"	PHP_INI_ALL
assert.warning	"1"	PHP_INI_ALL
assert.callback	NULL	PHP_INI_ALL
assert.quiet_eval	"0"	PHP_INI_ALL
safe_mode_protected_env_vars	SAFE_MODE_PROTECTED_ENV_VARS	PHP_INI_SYSTEM
safe_mode_allowed_env_vars	SAFE_MODE_ALLOWED_ENV_VARS	PHP_INI_SYSTEM
url_rewriter.tags	"a=href,area=href,frame=src,form=fakeentry"	PHP_INI_ALL
sybct.allow_persistent	"1"	PHP_INI_SYSTEM
sybct.max_persistent	"-1"	PHP_INI_SYSTEM
sybct.max_links	"-1"	PHP_INI_SYSTEM
sybct.min_server_severity	"10"	PHP_INI_ALL
sybct.min_client_severity	"10"	PHP_INI_ALL
sybct.hostname	NULL	PHP_INI_ALL
tokenizer.global_value	"42"	PHP_INI_ALL
tokenizer.global_string	"foobar"	PHP_INI_ALL
vpopmail.directory	""	PHP_INI_ALL
zlib.output_compression	"0"	PHP_INI_SYSTEM\|PHP_INI_PERDIR
zlib.output_compression_level	"-1"	PHP_INI_ALL
define_syslog_variables	"0"	PHP_INI_ALL
highlight.bg	HL_BG_COLOR	PHP_INI_ALL
highlight.comment	HL_COMMENT_COLOR	PHP_INI_ALL
highlight.default	HL_DEFAULT_COLOR	PHP_INI_ALL
highlight.html	HL_HTML_COLOR	PHP_INI_ALL
highlight.keyword	HL_KEYWORD_COLOR	PHP_INI_ALL
highlight.string	HL_STRING_COLOR	PHP_INI_ALL
allow_call_time_pass_reference	"1"	PHP_INI_SYSTEM\|PHP_INI_PERDIR
asp_tags	"0"	PHP_INI_SYSTEM\|PHP_INI_PERDIR
display_errors	"1"	PHP_INI_ALL
display_startup_errors	"0"	PHP_INI_ALL
enable_dl	"1"	PHP_INI_SYSTEM
expose_php	"1"	PHP_INI_SYSTEM
html_errors	"1"	PHP_INI_SYSTEM
xmlrpc_errors	"0"	PHP_INI_SYSTEM
xmlrpc_error_number	"0"	PHP_INI_ALL
ignore_user_abort	"0"	PHP_INI_ALL
implicit_flush	"0"	PHP_INI_PERDIR\|PHP_INI_SYSTEM
log_errors	"0"	PHP_INI_ALL
log_errors_max_len	"1024"	PHP_INI_ALL
ignore_repeated_errors	"0"	PHP_INI_ALL
ignore_repeated_source	"0"	PHP_INI_ALL
magic_quotes_gpc	"1"	PHP_INI_PERDIR\|PHP_INI_SYSTEM
magic_quotes_runtime	"0"	PHP_INI_ALL
magic_quotes_sybase	"0"	PHP_INI_ALL
output_buffering	"0"	PHP_INI_PERDIR\|PHP_INI_SYSTEM
output_handler	NULL	PHP_INI_PERDIR\|PHP_INI_SYSTEM
register_argc_argv	"1"	PHP_INI_PERDIR\|PHP_INI_SYSTEM
register_globals	"0"	PHP_INI_PERDIR\|PHP_INI_SYSTEM
safe_mode	"1"	PHP_INI_SYSTEM
safe_mode	"0"	PHP_INI_SYSTEM
safe_mode_include_dir	NULL	PHP_INI_SYSTEM
safe_mode_gid	"0"	PHP_INI_SYSTEM
short_open_tag	DEFAULT_SHORT_OPEN_TAG	PHP_INI_SYSTEM\|PHP_INI_PERDIR
sql.safe_mode	"0"	PHP_INI_SYSTEM
track_errors	"0"	PHP_INI_ALL
y2k_compliance	"0"	PHP_INI_ALL
unserialize_callback_func	NULL	PHP_INI_ALL
arg_separator.output	"&"	PHP_INI_ALL
arg_separator.input	"&"	PHP_INI_SYSTEM\|PHP_INI_PERDIR
auto_append_file	NULL	PHP_INI_SYSTEM\|PHP_INI_PERDIR
auto_prepend_file	NULL	PHP_INI_SYSTEM\|PHP_INI_PERDIR
doc_root	NULL	PHP_INI_SYSTEM
default_charset	SAPI_DEFAULT_CHARSET	PHP_INI_ALL
default_mimetype	SAPI_DEFAULT_MIMETYPE	PHP_INI_ALL
error_log	NULL	PHP_INI_ALL
extension_dir	PHP_EXTENSION_DIR	PHP_INI_SYSTEM
gpc_order	"GPC"	PHP_INI_ALL
include_path	PHP_INCLUDE_PATH	PHP_INI_ALL
max_execution_time	"30"	PHP_INI_ALL
open_basedir	NULL	PHP_INI_SYSTEM
safe_mode_exec_dir	"1"	PHP_INI_SYSTEM
upload_max_filesize	"2M"	PHP_INI_SYSTEM
file_uploads	"1"	PHP_INI_SYSTEM
post_max_size	"8M"	PHP_INI_SYSTEM
upload_tmp_dir	NULL	PHP_INI_SYSTEM
user_dir	NULL	PHP_INI_SYSTEM
variables_order	NULL	PHP_INI_ALL
error_append_string	NULL	PHP_INI_ALL
error_prepend_string	NULL	PHP_INI_ALL
SMTP	"localhost"	PHP_INI_ALL
smtp_port	25	PHP_INI_ALL
browscap	NULL	PHP_INI_SYSTEM
error_reporting	NULL	PHP_INI_ALL
memory_limit	"8M"	PHP_INI_ALL
precision	"14"	PHP_INI_ALL
sendmail_from	NULL	PHP_INI_ALL
sendmail_path	DEFAULT_SENDMAIL_PATH	PHP_INI_SYSTEM
disable_functions	""	PHP_INI_SYSTEM
allow_url_fopen	"1"	PHP_INI_ALL
always_populate_raw_post_data	"0"	PHP_INI_ALL
xbithack	"0"	PHP_INI_ALL
engine	"1"	PHP_INI_ALL
last_modified	"0"	PHP_INI_ALL
child_terminate	"0"	PHP_INI_ALL
async_send	"0"	PHP_INI_ALL

Table 2. Definition of PHP_INI_* constants

Constant	Value	Meaning
PHP_INI_USER	1	Entry can be set in user scripts
PHP_INI_PERDIR	2	Entry can be set in `.htaccess` and VHost directives in httpd.conf.
PHP_INI_SYSTEM	4	Entry can be set in `php.ini` or `httpd.conf` (but not in VHost blocks in httpd.conf).
PHP_INI_ALL	7	Entry can be set anywhere

php_logo_guid

(PHP 4 )

php_logo_guid -- Gets the logo guid

Description

string php_logo_guid ( void)

Note: This functionality was added in PHP 4.0.0.

And if you want to print the core developers and the documentation group, in a page of its own, you will use:

<?php
phpcredits(CREDITS_GROUP + CREDITS_DOCS + CREDITS_FULLPAGE);
?>

And if you feel like embedding all the credits in your page, then code like the one below will do it:

<html>
 <head>
  <title>My credits page</title>
 </head>
 <body>
  <?php
 // some code of your own
 phpcredits(CREDITS_ALL);
 // some more code
 ?>
 </body>
</html>

Table 1. Pre-defined phpcredits() flags

name	description
CREDITS_ALL	All the credits, equivalent to using: CREDITS_DOCS + CREDITS_GENERAL + CREDITS_GROUP + CREDITS_MODULES + CREDITS_FULLPAGE. It generates a complete stand-alone HTML page with the appropriate tags.
CREDITS_DOCS	The credits for the documentation team
CREDITS_FULLPAGE	Usually used in combination with the other flags. Indicates that the a complete stand-alone HTML page needs to be printed including the information indicated by the other flags.
CREDITS_GENERAL	General credits: Language design and concept, PHP 4.0 authors and SAPI module.
CREDITS_GROUP	A list of the core developers
CREDITS_MODULES	A list of the extension modules for PHP, and their authors
CREDITS_SAPI	A list of the server API modules for PHP, and their authors

phpinfo

(PHP 3, PHP 4 )

phpinfo -- Outputs lots of PHP information

Description

int phpinfo ( [int what])

Outputs a large amount of information about the current state of PHP. This includes information about PHP compilation options and extensions, the PHP version, server information and environment (if compiled as a module), the PHP environment, OS version information, paths, master and local values of configuration options, HTTP headers, and the PHP License.

Because every system is setup differently, phpinfo() is commonly used to check configuration settings and for available predefined variables on a given system. Also, phpinfo() is a valuable debugging tool as it contains all EGPCS (Environment, GET, POST, Cookie, Server) data.

The output may be customized by passing one or more of the following constants bitwise values summed together in the optional what parameter. One can also combine the respective constants or bitwise values together with the or operator.

Table 1. phpinfo() options

Name (constant)	Value	Description
INFO_GENERAL	1	The configuration line, `php.ini` location, build date, Web Server, System and more.
INFO_CREDITS	2	PHP 4 Credits. See also phpcredits().
INFO_CONFIGURATION	4	Current Local and Master values for php directives. See also ini_get().
INFO_MODULES	8	Loaded modules and their respective settings.
INFO_ENVIRONMENT	16	Environment Variable information that's also available in `$_ENV`.
INFO_VARIABLES	32	Shows all predefined variables from EGPCS (Environment, GET, POST, Cookie, Server).
INFO_LICENSE	64	PHP License information. See also the license faq.
INFO_ALL	-1	Shows all of the above. This is the default value.

Example 1. phpinfo() examples
<?php // Show all information, defaults to INFO_ALL phpinfo(); // Show just the module information. // phpinfo(8) yields identical results. phpinfo(INFO_MODULES); ?>

Note: Parts of the information displayed are disabled when the expose_php configuration setting is set to off. This includes the PHP and Zend logos, and the credits.

phpversion

(PHP 3, PHP 4 )

phpversion -- Gets the current PHP version

Description

string phpversion ( void)

Returns a string containing the version of the currently running PHP parser.

Note: This information is also available in the predefined constant PHP_VERSION.

Example 1. phpversion() Example
<?php // prints e.g. 'Current PHP version: 4.1.1' echo 'Current PHP version: ' . phpversion(); ?>

putenv

(PHP 3, PHP 4 )

putenv -- Sets the value of an environment variable

Description

void putenv ( string setting)

Adds setting to the server environment. The environment variable will only exist for the duration of the current request. At the end of the request the environment is restored to its original state.

Setting certain environment variables may be a potential security breach. The safe_mode_allowed_env_vars directive contains a comma-delimited list of prefixes. In Safe Mode, the user may only alter environment variables whose names begin with the prefixes supplied by this directive. By default, users will only be able to set environment variables that begin with PHP_ (e.g. PHP_FOO=BAR). Note: if this directive is empty, PHP will let the user modify ANY environment variable!

The safe_mode_protected_env_vars directive contains a comma-delimited list of environment variables, that the end user won't be able to change using putenv(). These variables will be protected even if safe_mode_allowed_env_vars is set to allow to change them.

Warning

These directives have only effect when safe-mode itself is enabled!

Example 1. Setting an Environment Variable
putenv ("UNIQID=$uniqid");

set_magic_quotes_runtime

(PHP 3>= 3.0.6, PHP 4 )

set_magic_quotes_runtime -- Sets the current active configuration setting of magic_quotes_runtime

Description

long set_magic_quotes_runtime ( int new_setting)

Set the current active configuration setting of magic_quotes_runtime (0 for off, 1 for on).

set_time_limit

(PHP 3, PHP 4 )

set_time_limit -- Limits the maximum execution time

Description

void set_time_limit ( int seconds)

Set the number of seconds a script is allowed to run. If this is reached, the script returns a fatal error. The default limit is 30 seconds or, if it exists, the max_execution_time value defined in the configuration file. If seconds is set to zero, no time limit is imposed.

When called, set_time_limit() restarts the timeout counter from zero. In other words, if the timeout is the default 30 seconds, and 25 seconds into script execution a call such as set_time_limit(20) is made, the script will run for a total of 45 seconds before timing out.

set_time_limit() has no effect when PHP is running in safe mode. There is no workaround other than turning off safe mode or changing the time limit in the configuration file.

Note: The set_time_limit() function and the configuration directive max_execution_time only affect the execution time of the script itself. Any time spent on activity that happens outside the execution of the script such as system calls using system(), the sleep() function, database queries, etc. is not included when determining the maximum time that the script has been running.

version_compare

(PHP 4 >= 4.1.0)

version_compare -- Compares two "PHP-standardized" version number strings

Description

int version_compare ( string version1, string version2 [, string operator])

version_compare() compares two "PHP-standardized" version number strings. This is useful if you would like to write programs working only on some versions of PHP.

version_compare() returns -1 if the first version is lower than the second, 0 if they are equal, and +1 if the second is lower.

If you specify the third optional operator argument, you can test for a particular relationship. The possible operators are: <, lt, <=, le, >, gt, >=, ge, ==, =, eq, !=, <>, ne respectively. Using this argument, the function will return 1 if the relationship is the one specified by the operator, 0 otherwise.

Example 1. version_compare() Example
// prints -1 echo version_compare("4.0.4", "4.0.6"); // these all print 1 echo version_compare("4.0.4", "4.0.6", "<"); echo version_compare("4.0.6", "4.0.6", "eq");

zend_logo_guid

(PHP 4 )

zend_logo_guid -- Gets the zend guid

Description

string zend_logo_guid ( void)

Note: This functionality was added in PHP 4.0.0.

zend_version

(PHP 4 )

zend_version -- Gets the version of the current Zend engine

Description

string zend_version ( void)

Returns a string containing the version of the currently running PHP parser.
Example 1. zend_version() Example
// prints e.g. 'Zend engine version: 1.0.4' echo "Zend engine version: " . zend_version();

LXXX. POSIX functions

Introduction

This module contains an interface to those functions defined in the IEEE 1003.1 (POSIX.1) standards document which are not accessible through other means. POSIX.1 for example defined the open(), read(), write() and close() functions, too, which traditionally have been part of PHP 3 for a long time. Some more system specific functions have not been available before, though, and this module tries to remedy this by providing easy access to these functions.

Warning

Sensitive data can be retrieved with the POSIX functions, e.g. posix_getpwnam() and friends. None of the POSIX function perform any kind of access checking when safe mode is enabled. It's therefore strongly advised to disable the POSIX extension at all (use --disable-posix in your configure line) if you're operating in such an environment.

Note: The POSIX extension is not available on the Windows platform.

posix_getsid

(PHP 3>= 3.0.10, PHP 4 )

posix_getsid -- Get the current sid of the process

Description

int posix_getsid ( int pid)

bool posix_kill ( int pid, int sig)

Send the signal sig to the process with the process identifier pid. Returns FALSE, if unable to send the signal, TRUE otherwise.

See also the kill(2) manual page of your POSIX system, which contains additional information about negative process identifiers, the special pid 0, the special pid -1, and the signal number 0.

posix_mkfifo

(PHP 3>= 3.0.13, PHP 4 )

posix_mkfifo -- Create a fifo special file (a named pipe)

Description

bool posix_mkfifo ( string pathname, int mode)

posix_mkfifo() creates a special FIFO file which exists in the file system and acts as a bidirectional communication endpoint for processes.

The second parameter mode has to be given in octal notation (e.g. 0644). The permission of the newly created FIFO also depends on the setting of the current umask(). The permissions of the created file are (mode & ~umask).

Note: When safe mode is enabled, PHP checks whether the directory in which you are about to operate has the same UID (owner) as the script that is being executed.

bool posix_setuid ( int uid)

Set the real user ID of the current process. This is a privileged function and you need appropriate privileges (usually root) on your system to be able to perform this function.

Returns TRUE on success, FALSE otherwise. See also posix_setgid().

posix_times

(PHP 3>= 3.0.13, PHP 4 )

posix_times -- Get process times

Description

array posix_times ( void)

Returns a hash of strings with information about the current process CPU usage. The indices of the hash are

ticks - the number of clock ticks that have elapsed since reboot.
utime - user time used by the current process.
stime - system time used by the current process.
cutime - user time used by current process and children.
cstime - system time used by current process and children.

posix_ttyname

(PHP 3>= 3.0.13, PHP 4 )

posix_ttyname -- Determine terminal device name

Description

string posix_ttyname ( int fd)

Needs to be written.

posix_uname

(PHP 3>= 3.0.10, PHP 4 )

posix_uname -- Get system name

Description

array posix_uname ( void)

Returns a hash of strings with information about the system. The indices of the hash are

sysname - operating system name (e.g. Linux)
nodename - system name (e.g. valiant)
release - operating system release (e.g. 2.2.10)
version - operating system version (e.g. #4 Tue Jul 20 17:01:36 MEST 1999)
machine - system architecture (e.g. i586)
domainname - DNS domainname (e.g. php.net)

domainname is a GNU extension and not part of POSIX.1, so this field is only available on GNU systems or when using the GNU libc.

Posix requires that you must not make any assumptions about the format of the values, e.g. you cannot rely on three digit version numbers or anything else returned by this function.

LXXXI. PostgreSQL functions

Introduction

PostgreSQL database is Open Source product and available without cost. Postgres, developed originally in the UC Berkeley Computer Science Department, pioneered many of the object-relational concepts now becoming available in some commercial databases. It provides SQL92/SQL99 language support, transaction integrity and type extensibility. PostgreSQL is an open source descendant of this original Berkeley code.

Requirements

To use PostgreSQL support, you need PostgreSQL 6.5 or later, PostgreSQL 7.0 or later to enable all PostgreSQL module features. PostgreSQL supports many character encoding including multibyte character encoding. The current version and more information about PostgreSQL is available at http://www.postgresql.org/.

Installation

In order to enable PostgreSQL support, --with-pgsql[=DIR] is required when you compile PHP. If shared object module is available, PostgreSQL module may be loaded using extension directive in php.ini or dl() function.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. PostgreSQL configuration options

Name	Default	Changeable
pgsql.allow_persistent	"1"	PHP_INI_SYSTEM
pgsql.max_persistent	"-1"	PHP_INI_SYSTEM
pgsql.max_links	"-1"	PHP_INI_SYSTEM
pgsql.auto_reset_persistent	"0"	PHP_INI_SYSTEM
pgsql.ignore_notice	"0"	PHP_INI_ALL
pgsql.log_notice	"0"	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Here is a short explanation of the configuration directives.

pgsql.allow_persistent boolean: Whether to allow persistent Postgres connections.
pgsql.max_persistent integer: The maximum number of persistent Postgres connections per process.
pgsql.max_links integer: The maximum number of Postgres connections per process, including persistent connections.

How to use and hints

Warning

Using the PostgreSQL module with PHP 4.0.6 is not recommended due to a bug in the notice message handling code. Use 4.1.0 or later.

Warning

PostgreSQL function names will be changed in 4.2.0 release to confirm to current coding standards. Most of new names will have additional underscores, e.g. pg_lo_open(). Some functions are renamed to different name for consistency. e.g. pg_exec() to pg_query(). Older names can be used in 4.2.0 and a few releases from 4.2.0, but they may be deleted in the future.

Table 2. Function names changed

Old name	New name
pg_exec()	pg_query()
pg_getlastoid()	pg_last_oid()
pg_cmdtuples()	pg_affected_rows()
pg_numrows()	pg_num_rows()
pg_numfields()	pg_num_fields()
pg_fieldname()	pg_field_name()
pg_fieldsize()	pg_field_size()
pg_fieldnum()	pg_field_num()
pg_fieldprtlen()	pg_field_prtlen()
pg_fieldisnull()	pg_field_is_null()
pg_freeresult()	pg_free_result()
pg_result()	pg_fetch_result()
pg_loreadall()	pg_lo_read_all()
pg_locreate()	pg_lo_create()
pg_lounlink()	pg_lo_unlink()
pg_loopen()	pg_lo_open()
pg_loclose()	pg_lo_close()
pg_loread()	pg_lo_read()
pg_lowrite()	pg_lo_write()
pg_loimport()	pg_lo_import()
pg_loexport()	pg_lo_export()

The old pg_connect()/pg_pconnect() syntax will be deprecated to support asynchronous connections in the future. Please use a connection string for pg_connect() and pg_pconnect().

Not all functions are supported by all builds. It depends on your libpq (The PostgreSQL C Client interface) version and how libpq is compiled. If there is missing function, libpq does not support the feature required for the function.

It is also important that you use newer libpq than PostgreSQL Server to be connected. If you use libpq older than PostgreSQL Server expects, you may have problems.

Since version 6.3 (03/02/1998) PostgreSQL uses unix domain sockets by default. TCP port will NOT be opened by default. A table is shown below describing these new connection possibilities. This socket will be found in /tmp/.s.PGSQL.5432. This option can be enabled with the '-i' flag to postmaster and it's meaning is: "listen on TCP/IP sockets as well as Unix domain sockets".

Table 3. Postmaster and PHP

Postmaster	PHP	Status
postmaster &	pg_connect("dbname=MyDbName");	OK
postmaster -i &	pg_connect("dbname=MyDbName");	OK
postmaster &	pg_connect("host=localhost dbname=MyDbName");	Unable to connect to PostgreSQL server: connectDB() failed: Is the postmaster running and accepting TCP/IP (with -i) connection at 'localhost' on port '5432'? in /path/to/file.php on line 20.
postmaster -i &	pg_connect("host=localhost dbname=MyDbName");	OK

A connection to PostgreSQL server can be established with the following value pairs set in the command string: $conn = pg_connect("host=myHost port=myPort tty=myTTY options=myOptions dbname=myDB user=myUser password=myPassword ");

The previous syntax of: $conn = pg_connect ("host", "port", "options", "tty", "dbname") has been deprecated.

Environmental variables affect PostgreSQL server/client behavior. For example, PostgreSQL module will lookup PGHOST environment variable when the hostname is omitted in the connection string. Supported environment variables are different from version to version. Refer to PostgreSQL Programmer's Manual (libpq - Environment Variables) for details.

Make sure you set environment variables for appropriate user. Use $_ENV or getenv() to check which environment variables are available to the current process.

Example 1. Setting default parameters

PGHOST=pgsql.example.com
PGPORT=7890
PGDATABASE=web-system
PGUSER=web-user
PGPASSWORD=secret
PGDATESTYLE=ISO
PGTZ=JST
PGCLIENTENCODING=EUC-JP

export PGHOST PGPORT PGDATABASE PGUSER PGPASSWORD PGDATESTYLE PGTZ PGCLIENTENCODING

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

PGSQL_ASSOC (integer)
PGSQL_NUM (integer)
PGSQL_BOTH (integer)
PGSQL_CONNECTION_BAD (integer)
PGSQL_CONNECTION_OK (integer)
PGSQL_SEEK_SET (integer)
PGSQL_SEEK_CUR (integer)
PGSQL_SEEK_END (integer)
PGSQL_ESCAPE_STRING (integer)
PGSQL_ESCAPE_BYTEA (integer)
PGSQL_EMPTY_QUERY (integer)
PGSQL_COMMAND_OK (integer)
PGSQL_TUPLES_OK (integer)
PGSQL_COPY_OUT (integer)
PGSQL_COPY_IN (integer)
PGSQL_BAD_RESPONSE (integer)
PGSQL_NONFATAL_ERROR (integer)
PGSQL_FATAL_ERROR (integer)

Examples

Starting with PostgreSQL 7.1.0, you can store up to 1GB into a field of type text. In older versions, this was limited to the block size (default was 8KB, maximum was 32KB, defined at compile time)

To use the large object (lo) interface, it is required to enclose large object functions within a transaction block. A transaction block starts with a SQL statement BEGIN and if the transaction was valid ends with COMMIT or END. If the transaction fails the transaction should be closed with ROLLBACK or ABORT.
Example 2. Using Large Objects
<?php $database = pg_connect ("dbname=jacarta"); pg_query ($database, "begin"); $oid = pg_lo_create ($database); echo "$oid\n"; $handle = pg_lo_open ($database, $oid, "w"); echo "$handle\n"; pg_lo_write ($handle, "large object data"); pg_lo_close ($handle); pg_query ($database, "commit"); ?>
You should not close the connection to the PostgreSQL server before closing the large object.

Table of Contents
pg_affected_rows -- Returns number of affected records(tuples)
pg_cancel_query -- Cancel async query
pg_client_encoding -- Get the client encoding
pg_close -- Close a PostgreSQL connection
pg_connect -- Open a PostgreSQL connection
pg_connection_busy -- Get connection is busy or not
pg_connection_reset -- Reset connection (reconnect)
pg_connection_status -- Get connection status
pg_convert -- Convert associative array value into suitable for SQL statement.
pg_copy_from -- Insert records into a table from an array
pg_copy_to -- Copy a table to an array
pg_dbname -- Get the database name
pg_delete -- Delete records.
pg_end_copy -- Sync with PostgreSQL backend
pg_escape_bytea -- Escape binary for bytea type
pg_escape_string -- Escape string for text/char type
pg_fetch_all -- Fetch a row as an array
pg_fetch_array -- Fetch a row as an array
pg_fetch_assoc -- Fetch a row as an array
pg_fetch_object -- Fetch a row as an object
pg_fetch_result -- Returns values from a result resource
pg_fetch_row -- Get a row as an enumerated array
pg_field_is_null -- Test if a field is NULL
pg_field_name -- Returns the name of a field
pg_field_num -- Returns the field number of the named field
pg_field_prtlen -- Returns the printed length
pg_field_size -- Returns the internal storage size of the named field
pg_field_type -- Returns the type name for the corresponding field number
pg_free_result -- Free result memory
pg_get_notify -- Ping database connection
pg_get_pid -- Ping database connection
pg_get_result -- Get asynchronous query result
pg_host -- Returns the host name associated with the connection
pg_insert -- Insert array into table.
pg_last_error -- Get the last error message string of a connection
pg_last_notice -- Returns the last notice message from PostgreSQL server
pg_last_oid -- Returns the last object's oid
pg_lo_close -- Close a large object
pg_lo_create -- Create a large object
pg_lo_export -- Export a large object to file
pg_lo_import -- Import a large object from file
pg_lo_open -- Open a large object
pg_lo_read_all -- Read a entire large object and send straight to browser
pg_lo_read -- Read a large object
pg_lo_seek -- Seeks position of large object
pg_lo_tell -- Returns current position of large object
pg_lo_unlink -- Delete a large object
pg_lo_write -- Write a large object
pg_meta_data -- Get meta data for table.
pg_num_fields -- Returns the number of fields
pg_num_rows -- Returns the number of rows
pg_options -- Get the options associated with the connection
pg_pconnect -- Open a persistent PostgreSQL connection
pg_ping -- Ping database connection
pg_port -- Return the port number associated with the connection
pg_put_line -- Send a NULL-terminated string to PostgreSQL backend
pg_query -- Execute a query
pg_result_error -- Get error message associated with result
pg_result_seek -- Set internal row offset in result resource
pg_result_status -- Get status of query result
pg_select -- Select records.
pg_send_query -- Send asynchronous query
pg_set_client_encoding -- Set the client encoding
pg_trace -- Enable tracing a PostgreSQL connection
pg_tty -- Return the tty name associated with the connection
pg_unescape_bytea -- Escape binary for bytea type
pg_untrace -- Disable tracing of a PostgreSQL connection
pg_update -- Update table.

pg_affected_rows

(PHP 4 >= 4.2.0)

pg_affected_rows -- Returns number of affected records(tuples)

Description

int pg_affected_rows ( resource result)

pg_affected_rows() returns the number of tuples (instances/records/rows) affected by INSERT, UPDATE, and DELETE queries executed by pg_query(). If no tuple is affected by this function, it will return 0.
Example 1. pg_affected_rows()
<?php $result = pg_query ($conn, "INSERT INTO publisher VALUES ('Author')"); $cmdtuples = pg_affected_rows ($result); echo $cmdtuples . " tuples are affected."; ?>

Note: This function used to be called pg_cmdtuples().

See also pg_query() and pg_num_rows().

pg_cancel_query

(PHP 4 >= 4.2.0)

pg_cancel_query -- Cancel async query

Description

bool pg_cancel_query ( resource connection)

pg_cancel_query() cancel asynchronous query sent by pg_send_query(). You cannot cancel query executed by pg_query().

pg_client_encoding

(PHP 3 CVS only, PHP 4 >= 4.0.3)

pg_client_encoding -- Get the client encoding

Description

string pg_client_encoding ( [resource connection])

pg_client_encoding() returns the client encoding as the string. The returned string should be either : SQL_ASCII, EUC_JP, EUC_CN, EUC_KR, EUC_TW, UNICODE, MULE_INTERNAL, LATINX (X=1...9), KOI8, WIN, ALT, SJIS, BIG5, WIN1250.

Note: This function requires PHP-4.0.3 or higher and PostgreSQL-7.0 or higher. If libpq is compiled without multibyte encoding support, pg_set_client_encoding() always return "SQL_ASCII". Supported encoding depends on PostgreSQL version. Refer to PostgreSQL manual for details to enable multibyte support and encoding supported.
The function used to be called pg_clientencoding().

pg_close

(PHP 3, PHP 4 )

pg_close -- Close a PostgreSQL connection

Description

bool pg_close ( resource connection)

pg_close() closes the non-persistent connection to a PostgreSQL database associated with the given connection resource. Returns TRUE on success or FALSE on failure.

Note: Using pg_close() is not usually necessary, as non-persistent open connections are automatically closed at the end of the script.

pg_connection_status() returns a connection status. Possible statuses are PGSQL_CONNECTION_OK and PGSQL_CONNECTION_BAD.

pg_convert

(PHP 4 CVS only)

pg_convert -- Convert associative array value into suitable for SQL statement.

Description

array pg_convert ( resource connection, string table_name, array assoc_array [, int options])

pg_convert() check and convert assoc_array suitable for SQL statement.

Note: This function is experimental.

Example 1. pg_delete

<?php 
    $db = pg_connect ('dbname=foo');
    // This is safe, since $_POST is converted automatically
    $res = pg_delete($db, 'post_log', $_POST);
    if ($res) {
        echo "POST data is deleted: $res\n";
    }
    else {
        echo "User must have sent wrong inputs\n";
    }
?>

Note: This function is experimental.

pg_fetch_array() is an extended version of pg_fetch_row(). In addition to storing the data in the numeric indices (field index) to the result array, it also stores the data in associative indices (field name) by default.

row is row (record) number to be retrieved. First row is 0.

result_type is optional parameter controls how return value is initialized. result_type is a constant and can take the following values: PGSQL_ASSOC, PGSQL_NUM, and PGSQL_BOTH. pg_fetch_array() returns associative array that has field name as key for PGSQL_ASSOC. field index as key with PGSQL_NUM and both field name/index as key with PGSQL_BOTH. Default is PGSQL_BOTH.

Note: result_type was added in PHP 4.0.

pg_fetch_array() is NOT significantly slower than using pg_fetch_row(), while it provides a significant ease of use.

Note: From 4.1.0, row became optional. Calling pg_fetch_array() will increment internal row counter by 1.

pg_fetch_assoc

(no version information, might be only in CVS)

pg_fetch_assoc -- Fetch a row as an array

Description

array pg_fetch_assoc ( resource result [, int row])

pg_fetch_assoc() returns an associative array that corresponds to the fetched row (tuples/records). It returns FALSE, if there are no more rows.

pg_fetch_assoc() is an extended version of pg_fetch_row(). In addition to storing the data in the numeric indices (field index) to the result array, it also stores the data in associative indices (field name) by default.

row is row (record) number to be retrieved. First row is 0.

pg_fetch_assoc() is NOT significantly slower than using pg_fetch_row(), while it provides a significant ease of use.

pg_fetch_object

(PHP 3>= 3.0.1, PHP 4 )

pg_fetch_object -- Fetch a row as an object

Description

object pg_fetch_object ( resource result [, int row [, int result_type]])

pg_fetch_object() returns an object with properties that correspond to the fetched row. It returns FALSE if there are no more rows or error.

pg_fetch_object() is similar to pg_fetch_array(), with one difference - an object is returned, instead of an array. Indirectly, that means that you can only access the data by the field names, and not by their offsets (numbers are illegal property names).

row is row (record) number to be retrieved. First row is 0.

Speed-wise, the function is identical to pg_fetch_array(), and almost as quick as pg_fetch_row() (the difference is insignificant).

Note: From 4.1.0, row is optional.
From 4.3.0, result_type is default to PGSQL_ASSOC while older versions' default was PGSQL_BOTH. There is no use for numeric property, since numeric property name is invalid in PHP.
result_type may be deleted in future versions.

Example 1. Postgres fetch object
<?php $database = "verlag"; $db_conn = pg_connect ("host=localhost port=5432 dbname=$database"); if (!$db_conn): ?> <H1>Failed connecting to postgres database <?php echo $database ?></H1> <?php exit; endif; $qu = pg_query ($db_conn, "SELECT * FROM verlag ORDER BY autor"); $row = 0; // postgres needs a row counter other dbs might not while ($data = pg_fetch_object ($qu, $row)) { echo $data->autor." ("; echo $data->jahr ."): "; echo $data->titel."<BR>"; $row++; } ?> <PRE> <?php $fields[] = Array ("autor", "Author"); $fields[] = Array ("jahr", " Year"); $fields[] = Array ("titel", " Title"); $row= 0; // postgres needs a row counter other dbs might not while ($data = pg_fetch_object ($qu, $row)) { echo "----------\n"; reset ($fields); while (list (,$item) = each ($fields)): echo $item[1].": ".$data->$item[0]."\n"; endwhile; $row++; } echo "----------\n"; ?> </PRE> <?php pg_free_result ($qu); pg_close ($db_conn); ?>

Note: From 4.1.0, row became optional. Calling pg_fetch_object() will increment internal row counter counter by 1.

pg_fetch_result

(PHP 4 >= 4.2.0)

pg_fetch_result -- Returns values from a result resource

Description

mixed pg_fetch_result ( resource result, int row, mixed field)

pg_fetch_result() returns values from a result resource returned by pg_query(). row is integer. field is field name (string) or field index (integer). The row and field specify what cell in the table of results to return. Row numbering starts from 0. Instead of naming the field, you may use the field index as an unquoted number. Field indices start from 0.

PostgreSQL has many built in types and only the basic ones are directly supported here. All forms of integer types are returned as integer values. All forms of float, and real types are returned as float values. Boolean is returned as "t" or "f". All other types, including arrays are returned as strings formatted in the same default PostgreSQL manner that you would see in the psql program.

pg_fetch_row

(PHP 3>= 3.0.1, PHP 4 )

pg_fetch_row -- Get a row as an enumerated array

Description

array pg_fetch_row ( resource result, int row)

pg_fetch_row() fetches one row of data from the result associated with the specified result resource. The row (record) is returned as an array. Each result column is stored in an array offset, starting at offset 0.

It returns an array that corresponds to the fetched row, or FALSE if there are no more rows.

Example 1. Postgres fetch row
<?php $conn = pg_pconnect ("dbname=publisher"); if (!$conn) { echo "An error occured.\n"; exit; } $result = pg_query ($conn, "SELECT * FROM authors"); if (!$result) { echo "An error occured.\n"; exit; } $num = pg_num_rows($result); for ($i=0; $i < $num; $i++) { $r = pg_fetch_row($result, $i); for ($j=0; $j < count($r); $j++) { echo "$r[$j] "; } echo "<BR>"; } ?>

Note: From 4.1.0, row became optional. Calling pg_fetch_row() will increment internal row counter by 1.

pg_field_is_null

(PHP 4 >= 4.2.0)

pg_field_is_null -- Test if a field is NULL

Description

int pg_field_is_null ( resource result, int row, mixed field)

pg_field_is_null() test if a field is NULL or not. It returns 1 if the field in the given row is NULL. It returns 0 if the field in the given row is NOT NULL. Field can be specified as column index (number) or fieldname (string). Row numbering starts at 0.

Note: This function used to be called pg_fieldisnull().

pg_field_name

(PHP 4 >= 4.2.0)

pg_field_name -- Returns the name of a field

Description

string pg_field_name ( resource result, int field_number)

pg_field_name() returns the name of the field occupying the given field_number in the given PostgreSQL result resource. Field numbering starts from 0.

Note: This function used to be called pg_fieldname().

pg_field_num

(PHP 4 >= 4.2.0)

pg_field_num -- Returns the field number of the named field

Description

int pg_field_num ( resource result, string field_name)

pg_field_num() will return the number of the column (field) slot that corresponds to the field_name in the given PostgreSQL result resource. Field numbering starts at 0. This function will return -1 on error.

Note: This function used to be called pg_fieldnum().

pg_field_prtlen

(PHP 4 >= 4.2.0)

pg_field_prtlen -- Returns the printed length

Description

int pg_field_prtlen ( resource result, int row_number, string field_name)

pg_field_prtlen() returns the actual printed length (number of characters) of a specific value in a PostgreSQL result. Row numbering starts at 0. This function will return -1 on an error.

Note: This function used to be called pg_field_prtlen().

pg_field_size

(PHP 4 >= 4.2.0)

pg_field_size -- Returns the internal storage size of the named field

Description

int pg_field_size ( resource result, int field_number)

pg_field_size() returns the internal storage size (in bytes) of the field number in the given PostgreSQL result. Field numbering starts at 0. A field size of -1 indicates a variable length field. This function will return FALSE on error.

Note: This function used to be called pg_fieldsize().

pg_field_type

(PHP 4 >= 4.2.0)

pg_field_type -- Returns the type name for the corresponding field number

Description

string pg_field_type ( resource result, int field_number)

pg_field_type() returns a string containing the type name of the given field_number in the given PostgreSQL result resource. Field numbering starts at 0.

Note: This function used to be called pg_fieldtype().

See also pg_field_len() and pg_field_name().

pg_free_result

(PHP 4 >= 4.2.0)

pg_free_result -- Free result memory

Description

bool pg_free_result ( resource result)

pg_free_result() only needs to be called if you are worried about using too much memory while your script is running. All result memory will automatically be freed when the script is finished. But, if you are sure you are not going to need the result data anymore in a script, you may call pg_free_result() with the result resource as an argument and the associated result memory will be freed. Returns TRUE on success or FALSE on failure.

Note: This function used to be called pg_freeresult().

See also pg_connect() and pg_pconnect().

pg_insert

(PHP 4 CVS only)

pg_insert -- Insert array into table.

Description

bool pg_insert ( resource connection, string table_name, array assoc_array [, int options])

pg_insert() inserts assoc_array which has field=>value into table specified as table_name. If options is specified, pg_convert() is applied to assoc_array with specified option.

Example 1. pg_insert

<?php 
    $db = pg_connect ('dbname=foo');
    // This is safe, since $_POST is converted automatically
    $res = pg_insert($db, 'post_log', $_POST);
    if ($res) {
        echo "POST data is succesfully logged\n";
    }
    else {
        echo "User must have sent wrong inputs\n";
    }
?>

Note: This function is experimental.

See also pg_convert()

pg_last_error

(PHP 4 >= 4.2.0)

pg_last_error -- Get the last error message string of a connection

Description

string pg_last_error ( [resource connection])

pg_last_error() returns the last error message for given connection.

Error messages may be overwritten by internal PostgreSQL(libpq) function calls. It may not return appropriate error message, if multiple errors are occured inside a PostgreSQL module function.

Use pg_result_error(), pg_result_status() and pg_connection_status() for better error handling.

Note: This function used to be called pg_errormessage().

pg_last_notice

(PHP 4 >= 4.0.6)

pg_last_notice -- Returns the last notice message from PostgreSQL server

Description

string pg_last_notice ( resource connection)

pg_last_notice() returns the last notice message from the PostgreSQL server specified by connection. The PostgreSQL server sends notice messages in several cases, e.g. if the transactions can't be continued. With pg_last_notice(), you can avoid issuing useless queries, by checking whether the notice is related to the transaction or not.

Warning

This function is EXPERIMENTAL and it is not fully implemented yet. pg_last_notice() was added in PHP 4.0.6. However, PHP 4.0.6 has problem with notice message handling. Use of the PostgreSQL module with PHP 4.0.6 is not recommended even if you are not using pg_last_notice().

int pg_lo_import ( [resource connection, string pathname])

In versions before PHP 4.2.0 the syntax of this function was different, see the following definition:

int pg_lo_import ( string pathname [, resource connection])

The pathname argument specifies the pathname of the file to be imported as a large object. It returns FALSE if an error occurred, oid of the just created large object otherwise.

To use the large object (lo) interface, it is necessary to enclose it within a transaction block.

Note: When safe mode is enabled, PHP checks whether the files or directories you are about to operate on have the same UID (owner) as the script that is being executed.

Note: This function used to be called pg_loimport().

See also pg_lo_export() and pg_lo_open().

pg_lo_open

(PHP 4 >= 4.2.0)

pg_lo_open -- Open a large object

Description

resource pg_lo_open ( resource connection, int oid, string mode)

pg_lo_open() opens a Large Object and returns large object resource. The resource encapsulates information about the connection. oid specifies a valid large object oid and mode can be either "r", "w", or "rw". It returns FALSE if there is an error.

Warning

Do not close the database connection before closing the large object resource.

To use the large object (lo) interface, it is necessary to enclose it within a transaction block.

Note: This function used to be called pg_loopen().

pg_lo_read_all

(PHP 4 >= 4.2.0)

pg_lo_read_all -- Read a entire large object and send straight to browser

Description

int pg_lo_read_all ( resource large_object)

pg_lo_read_all() reads a large object and passes it straight through to the browser after sending all pending headers. Mainly intended for sending binary data like images or sound. It returns number of bytes read. It returns FALSE, if an error occurred.

To use the large object (lo) interface, it is necessary to enclose it within a transaction block.

Note: This function used to be called pg_loreadall().

pg_lo_read

(PHP 4 >= 4.2.0)

pg_lo_read -- Read a large object

Description

string pg_lo_read ( resource large_object, int len)

pg_lo_read() reads at most len bytes from a large object and returns it as a string. large_object specifies a valid large object resource andlen specifies the maximum allowable size of the large object segment. It returns FALSE if there is an error.

To use the large object (lo) interface, it is necessary to enclose it within a transaction block.

Note: This function used to be called pg_loread().

To use the large object (lo) interface, it is necessary to enclose it within a transaction block.

Note: This function used to be called pg_lo_unlink().

pg_lo_write

(PHP 4 >= 4.2.0)

pg_lo_write -- Write a large object

Description

int pg_lo_write ( resource large_object, string data)

pg_lo_write() writes at most to a large object from a variable data and returns the number of bytes actually written, or FALSE in the case of an error. large_object is a large object resource from pg_lo_open().

To use the large object (lo) interface, it is necessary to enclose it within a transaction block.

Note: This function used to be called pg_lo_write().

See also pg_lo_create() and pg_lo_open().

pg_meta_data

(no version information, might be only in CVS)

pg_meta_data -- Get meta data for table.

Description

array pg_meta_data ( resource connection, string table_name)

pg_meta_data() returns table definition for table_name as array. If there is error, it returns FALSE

Note: This function is experimental.

See also pg_convert()

pg_num_fields

(PHP 4 >= 4.2.0)

pg_num_fields -- Returns the number of fields

Description

int pg_num_fields ( resource result)

pg_num_fields() returns the number of fields (columns) in a PostgreSQL result. The argument is a result resource returned by pg_query(). This function will return -1 on error.

Note: This function used to be called pg_numfields().

pg_num_rows

(PHP 4 >= 4.2.0)

pg_num_rows -- Returns the number of rows

Description

int pg_num_rows ( resource result)

pg_num_rows() will return the number of rows in a PostgreSQL result resource. result is a query result resource returned by pg_query(). This function will return -1 on error.

Note: Use pg_affected_rows() to get number of rows affected by INSERT, UPDATE and DELETE query.

Note: This function used to be called pg_numrows().

pg_options

(PHP 3, PHP 4 )

pg_options -- Get the options associated with the connection

Description

string pg_options ( resource connection)

pg_options() will return a string containing the options specified on the given PostgreSQL connection resource.

pg_pconnect

(PHP 3, PHP 4 )

pg_pconnect -- Open a persistent PostgreSQL connection

Description

resource pg_pconnect ( string connection_string)

pg_pconnect() opens a connection to a PostgreSQL database. It returns a connection resource that is needed by other PostgreSQL functions.

For a description of the connection_string parameter, see pg_connect().

To enable persistent connection, the pgsql.allow_persistent php.ini directive must be set to "On" (which is the default). The maximum number of persistent connection can be defined with the pgsql.max_persistent php.ini directive (defaults to -1 for no limit). The total number of connections can be set with the pgsql.max_links php.ini directive.

pg_close() will not close persistent links generated by pg_pconnect().

pg_ping

(no version information, might be only in CVS)

pg_ping -- Ping database connection

Description

array pg_ping ( resource connection)

pg_ping() ping database connection, try to reconnect if it is broken. It returns TRUE if connection is alive, otherwise FALSE.

Example 1. PostgreSQL fetch array
<?php $conn = pg_pconnect ("dbname=publisher"); if (!$conn) { echo "An error occured.\n"; exit; } if (!pg_ping($conn)) die("Connection is broken\n"); ?>

pg_port

(PHP 3, PHP 4 )

pg_port -- Return the port number associated with the connection

Description

int pg_port ( resource connection)

pg_port() returns the port number that the given PostgreSQL connection resource is connected to.

pg_put_line

(PHP 4 >= 4.0.3)

pg_put_line -- Send a NULL-terminated string to PostgreSQL backend

Description

bool pg_put_line ( [resource connection, string data])

pg_put_line() sends a NULL-terminated string to the PostgreSQL backend server. This is useful for example for very high-speed inserting of data into a table, initiated by starting a PostgreSQL copy-operation. That final NULL-character is added automatically. Returns TRUE on success or FALSE on failure.

Note: The application must explicitly send the two characters "\." on the last line to indicate to the backend that it has finished sending its data.

See also pg_end_copy().
Example 1. High-speed insertion of data into a table
<?php $conn = pg_pconnect ("dbname=foo"); pg_query($conn, "create table bar (a int4, b char(16), d float8)"); pg_query($conn, "copy bar from stdin"); pg_put_line($conn, "3\thello world\t4.5\n"); pg_put_line($conn, "4\tgoodbye world\t7.11\n"); pg_put_line($conn, "\\.\n"); pg_end_copy($conn); ?>

pg_query

(PHP 4 >= 4.2.0)

pg_query -- Execute a query

Description

resource pg_query ( resource connection, string query)

pg_query() returns a query result resource if query could be executed. It returns FALSE on failure or if connection is not a valid connection. Details about the error can be retrieved using the pg_last_error() function if connection is valid. pg_last_error() sends an SQL statement to the PostgreSQL database specified by the connection resource. The connection must be a valid connection that was returned by pg_connect() or pg_pconnect(). The return value of this function is an query result resource to be used to access the results from other PostgreSQL functions such as pg_fetch_array().

Note: connection is a optional parameter for pg_query(). If connection is not set, default connection is used. Default connection is the last connection made by pg_connect() or pg_pconnect().
Although connection can be omitted, it is not recommended, since it could be a cause of hard to find bug in script.

Note: This function used to be called pg_exec(). pg_exec() is still available for compatibility reasons but users are encouraged to use the newer name.

Example 1. pg_select

<?php 
    $db = pg_connect ('dbname=foo');
    // This is safe, since $_POST is converted automatically
    $rec = pg_select($db, 'post_log', $_POST);
    if ($rec) {
        echo "Records selected\n";
        var_dump($rec);
    }
    else {
        echo "User must have sent wrong inputs\n";
    }
?>

Note: This function is experimental.

See also pg_convert()

pg_send_query

(PHP 4 >= 4.2.0)

pg_send_query -- Send asynchronous query

Description

bool pg_send_query ( resource connection, string query)

bool pg_send_query ( string query)

pg_send_query() send asynchronous query to the connection. Unlike pg_query(), it can send multiple query to PostgreSQL and get the result one by one using pg_get_result(). Script execution is not blocked while query is executing. Use pg_connection_busy() to check connection is busy (i.e. query is executing). Query may be canceled by calling pg_cancel_query().

Although user can send multiple query at once, user cannot send multiple query over busy connection. If query is sent while connection is busy, it waits until last query is finished and discards all result.

pg_set_client_encoding

(PHP 3 CVS only, PHP 4 >= 4.0.3)

pg_set_client_encoding -- Set the client encoding

Description

int pg_set_client_encoding ( [resource connection, string encoding])

pg_set_client_encoding() sets the client encoding and returns 0 if success or -1 if error.

encoding is the client encoding and can be either : SQL_ASCII, EUC_JP, EUC_CN, EUC_KR, EUC_TW, UNICODE, MULE_INTERNAL, LATINX (X=1...9), KOI8, WIN, ALT, SJIS, BIG5, WIN1250. Available encoding depends on your PostgreSQL and libpq version. Refer to PostgreSQL manual for supported encodings for your PostgreSQL.

Note: This function requires PHP-4.0.3 or higher and PostgreSQL-7.0 or higher. Supported encoding depends on PostgreSQL version. Refer to PostgreSQL manual for details.
The function used to be called pg_setclientencoding().

pg_trace

(PHP 4 >= 4.0.1)

pg_trace -- Enable tracing a PostgreSQL connection

Description

bool pg_trace ( string pathname [, string mode [, resource connection]])

pg_trace() enables tracing of the PostgreSQL frontend/backend communication to a debugging file specified as pathname. To fully understand the results, one needs to be familiar with the internals of PostgreSQL communication protocol. For those who are not, it can still be useful for tracing errors in queries sent to the server, you could do for example grep '^To backend' trace.log and see what query actually were sent to the PostgreSQL server. For more information, refer to PostgreSQL manual.

pathname and mode are the same as in fopen() (mode defaults to 'w'), connection specifies the connection to trace and defaults to the last one opened.

It returns TRUE if pathname could be opened for logging, FALSE otherwise.

See also fopen() and pg_untrace().

pg_tty

(PHP 3, PHP 4 )

pg_tty -- Return the tty name associated with the connection

Description

pg_update() updates records that matches condition with data. If options is specified, pg_convert() is applied to data with specified options.

Example 1. pg_update

<?php 
    $db = pg_connect ('dbname=foo');
    $data = array('field1'=>'AA', 'field2'=>'BB');
    // This is safe, since $_POST is converted automatically
    $res = pg_update($db, 'post_log', $_POST, $data);
    if ($res) {
        echo "Data is updated: $res\n";
    }
    else {
        echo "User must have sent wrong inputs\n";
    }
?>

Note: This function is experimental.

See also pg_convert()

LXXXII. Process Control Functions

Introduction

Process Control support in PHP implements the Unix style of process creation, program execution, signal handling and process termination. Process Control should not be enabled within a webserver environment and unexpected results may happen if any Process Control functions are used within a webserver environment.

This documentation is intended to explain the general usage of each of the Process Control functions. For detailed information about Unix process control you are encouraged to consult your systems documentation including fork(2), waitpid(2) and signal(2) or a comprehensive reference such as Advanced Programming in the UNIX Environment by W. Richard Stevens (Addison-Wesley).

Requirements

No external libraries are needed to build this extension.

Installation

Process Control support in PHP is not enabled by default. You will need to use the --enable-pcntl configuration option when compiling PHP to enable Process Control support.

Note: Currently, this module will not function on non-Unix platforms (Windows).

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

The following list of signals are supported by the Process Control functions. Please see your systems signal(7) man page for details of the default behavior of these signals.

WNOHANG (integer)
WUNTRACED (integer)
SIG_IGN (integer)
SIG_DFL (integer)
SIG_ERR (integer)
SIGHUP (integer)
SIGINT (integer)
SIGQUIT (integer)
SIGILL (integer)
SIGTRAP (integer)
SIGABRT (integer)
SIGIOT (integer)
SIGBUS (integer)
SIGFPE (integer)
SIGKILL (integer)
SIGUSR1 (integer)
SIGSEGV (integer)
SIGUSR2 (integer)
SIGPIPE (integer)
SIGALRM (integer)
SIGTERM (integer)
SIGSTKFLT (integer)
SIGCLD (integer)
SIGCHLD (integer)
SIGCONT (integer)
SIGSTOP (integer)
SIGTSTP (integer)
SIGTTIN (integer)
SIGTTOU (integer)
SIGURG (integer)
SIGXCPU (integer)
SIGXFSZ (integer)
SIGVTALRM (integer)
SIGPROF (integer)
SIGWINCH (integer)
SIGPOLL (integer)
SIGIO (integer)
SIGPWR (integer)
SIGSYS (integer)
SIGBABY (integer)

Examples

This example forks off a daemon process with a signal handler.

Example 1. Process Control Example

<?php

$pid = pcntl_fork();
if ($pid == -1) {
     die("could not fork"); 
} else if ($pid) {
     exit(); // we are the parent 
} else {
     // we are the child
}

// detatch from the controlling terminal
if (!posix_setsid()) {
    die("could not detach from terminal");
}

// setup signal handlers
pcntl_signal(SIGTERM, "sig_handler");
pcntl_signal(SIGHUP, "sig_handler");

// loop forever performing tasks
while(1) {

    // do something interesting here

}

function sig_handler($signo) {

     switch($signo) {
         case SIGTERM:
             // handle shutdown tasks
             exit;
             break;
         case SIGHUP:
             // handle restart tasks
             break;
         default:
             // handle all other signals
     }

}

?>

pcntl_exec

(PHP 4 >= 4.2.0)

pcntl_exec -- Executes specified program in current process space

Description

pcntl_waitpid() returns the process ID of the child which exited, -1 on error or zero if WNOHANG was used and no child was available

The value of pid can be one of the following:

Table 1. possible values for pid

`< -1`	wait for any child process whose process group ID is equal to the absolute value of `pid`.
`-1`	wait for any child process; this is the same behaviour that the wait function exhibits.
`0`	wait for any child process whose process group ID is equal to that of the calling process.
`> 0`	wait for the child whose process ID is equal to the value of `pid`.

pcntl_waitpid() will store status information in the status parameter which can be evaluated using the following functions: pcntl_wifexited(), pcntl_wifstopped(), pcntl_wifsignaled(), pcntl_wexitstatus(), pcntl_wtermsig() and pcntl_wstopsig().

The value of options is the value of zero or more of the following two global constants OR'ed together:

Table 2. possible values for options

`WNOHANG`	return immediately if no child has exited.
`WUNTRACED`	return for children which are stopped, and whose status has not been reported.

LXXXIII. Program Execution functions

Introduction

Those functions provides means to executes commands on the system itself, and means secure such commands.

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

escapeshellarg

(PHP 4 >= 4.0.3)

escapeshellarg -- escape a string to be used as a shell argument

Description

string escapeshellarg ( string arg)

escapeshellarg() adds single quotes around a string and quotes/escapes any existing single quotes allowing you to pass a string directly to a shell function and having it be treated as a single safe argument. This function should be used to escape individual arguments to shell functions coming from user input. The shell functions include exec(), system() and the backtick operator. A standard use would be:

system("ls ".escapeshellarg($dir));

See also exec(), popen(), system(), and the backtick operator.

escapeshellcmd

(PHP 3, PHP 4 )

escapeshellcmd -- escape shell metacharacters

Description

string escapeshellcmd ( string command)

escapeshellcmd() escapes any characters in a string that might be used to trick a shell command into executing arbitrary commands. This function should be used to make sure that any data coming from user input is escaped before this data is passed to the exec() or system() functions, or to the backtick operator. A standard use would be:

$e = escapeshellcmd($userinput);
system("echo $e"); // here we don't care if $e has spaces
$f = escapeshellcmd($filename);
system("touch \"/tmp/$f\"; ls -l \"/tmp/$f\""); // and here we do, so we use quotes

exec

(PHP 3, PHP 4 )

exec -- Execute an external program

Description

string exec ( string command [, array output [, int return_var]])

exec() executes the given command, however it does not output anything. It simply returns the last line from the result of the command. If you need to execute a command and have all the data from the command passed directly back without any interference, use the passthru() function.

If the array argument is present, then the specified array will be filled with every line of output from the command. Note that if the array already contains some elements, exec() will append to the end of the array. If you do not want the function to append elements, call unset() on the array before passing it to exec().

If the return_var argument is present along with the array argument, then the return status of the executed command will be written to this variable.

Warning

If you are going to allow data coming from user input to be passed to this function, then you should be using escapeshellarg() or escapeshellcmd() to make sure that users cannot trick the system into executing arbitrary commands.

Note: If you start a program using this function and want to leave it running in the background, you have to make sure that the output of that program is redirected to a file or some other output stream or else PHP will hang until the execution of the program ends.

passthru

(PHP 3, PHP 4 )

passthru -- Execute an external program and display raw output

Description

void passthru ( string command [, int return_var])

The passthru() function is similar to the exec() function in that it executes a command. If the return_var argument is present, the return status of the Unix command will be placed here. This function should be used in place of exec() or system() when the output from the Unix command is binary data which needs to be passed directly back to the browser. A common use for this is to execute something like the pbmplus utilities that can output an image stream directly. By setting the Content-type to image/gif and then calling a pbmplus program to output a gif, you can create PHP scripts that output images directly.

Warning

Note: If you start a program using this function and want to leave it running in the background, you have to make sure that the output of that program is redirected to a file or some other output stream or else PHP will hang until the execution of the program ends.

proc_close

(PHP 4 CVS only)

proc_close -- Close a process opened by proc_open and return the exit code of that process.

Description

int proc_close ( resource process)

proc_close() is similar to pclose() except that it only works on processes opened by proc_open(). proc_close() waits for the process to terminate, and returns it's exit code. If you have open pipes to that process, you should fclose() them prior to calling this function in order to avoid a deadlock - the child process may not be able to exit while the pipes are open.

proc_open

(PHP 4 CVS only)

proc_open -- Execute a command and open file pointers for input/output

Description

resource proc_open ( string cmd, array descriptorspec, array pipes)

proc_open() is similar to popen() but provides a much greater degree of control over the program execution. cmd is the command to be executed by the shell. descriptorspec is an indexed array where the key represents the descriptor number and the value represents how PHP will pass that descriptor to the child process. pipes will be set to an indexed array of file pointers that correspond to PHP's end of any pipes that are created. The return value is a resource representing the process; you should free it using proc_close() when you are finished with it.

$descriptorspec = array(
   0 => array("pipe", "r"),  // stdin is a pipe that the child will read from
   1 => array("pipe", "w"),  // stdout is a pipe that the child will write to
   2 => array("file", "/tmp/error-output.txt", "a"), // stderr is a file to write to
);
$process = proc_open("php", $descriptorspec, $pipes);
if (is_resource($process)) {
    // $pipes now looks like this:
    // 0 => writeable handle connected to child stdin
    // 1 => readable handle connected to child stdout
    // Any error output will be appended to /tmp/error-output.txt

    fwrite($pipes[0], "<?php echo \"Hello World!\"; ?>");
    fclose($pipes[0]);

    while(!feof($pipes[1])) {
        echo fgets($pipes[1], 1024);
    }
    fclose($pipes[1]);
    // It is important that you close any pipes before calling
    // proc_close in order to avoid a deadlock
    $return_value = proc_close($process);

    echo "command returned $return_value\n";
}

The file descriptor numbers in descriptorspec are not limited to 0, 1 and 2 - you may specify any valid file descriptor number and it will be passed to the child process. This allows your script to interoperate with other scripts that run as "co-processes". In particular, this is useful for passing passphrases to programs like PGP, GPG and openssl in a more secure manner. It is also useful for reading status information provided by those programs on auxillary file descriptors.

Note: Windows compatibility: Descriptors beyond 2 (stderr) are made available to the child process as inheritable handles, but since the Windows architecture does not associate file descriptor numbers with low-level handles, the child process does not (yet) have a means of accessing those handles. Stdin, stdout and stderr work as expected.

Note: This function was introduced in PHP 4.3.0.

Note: If you only need a uni-directional (one-way) process pipe, use popen() instead, as it is much easier to use.

shell_exec

(PHP 4 )

shell_exec -- Execute command via shell and return complete output as string

Description

string shell_exec ( string cmd)

This function is identical to the backtick operator.

system

(PHP 3, PHP 4 )

system -- Execute an external program and display output

Description

string system ( string command [, int return_var])

system() is just like the C version of the function in that it executes the given command and outputs the result. If a variable is provided as the second argument, then the return status code of the executed command will be written to this variable.

Warning

Note: If you start a program using this function and want to leave it running in the background, you have to make sure that the output of that program is redirected to a file or some other output stream or else PHP will hang until the execution of the program ends.

The system() call also tries to automatically flush the web server's output buffer after each line of output if PHP is running as a server module.

Returns the last line of the command output on success, and FALSE on failure.

If you need to execute a command and have all the data from the command passed directly back without any interference, use the passthru() function.

LXXXIV. Printer functions

Introduction

These functions are only available under Windows 9.x, ME, NT4 and 2000. They have been added in PHP 4 (4.0.4).

Installation

Add the line extension=php_printer.dll to your php.ini file.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Printer configuration options

Name	Default	Changeable
printer.default_printer	""	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Table of Contents
printer_abort -- Deletes the printer's spool file
printer_close -- Close an open printer connection
printer_create_brush -- Create a new brush
printer_create_dc -- Create a new device context
printer_create_font -- Create a new font
printer_create_pen -- Create a new pen
printer_delete_brush -- Delete a brush
printer_delete_dc -- Delete a device context
printer_delete_font -- Delete a font
printer_delete_pen -- Delete a pen
printer_draw_bmp -- Draw a bmp
printer_draw_chord -- Draw a chord
printer_draw_elipse -- Draw an ellipse
printer_draw_line -- Draw a line
printer_draw_pie -- Draw a pie
printer_draw_rectangle -- Draw a rectangle
printer_draw_roundrect -- Draw a rectangle with rounded corners
printer_draw_text -- Draw text
printer_end_doc -- Close document
printer_end_page -- Close active page
printer_get_option -- Retrieve printer configuration data
printer_list -- Return an array of printers attached to the server
printer_logical_fontheight -- Get logical font height
printer_open -- Open connection to a printer
printer_select_brush -- Select a brush
printer_select_font -- Select a font
printer_select_pen -- Select a pen
printer_set_option -- Configure the printer connection
printer_start_doc -- Start a new document
printer_start_page -- Start a new page
printer_write -- Write data to the printer

printer_abort

(no version information, might be only in CVS)

printer_abort -- Deletes the printer's spool file

Description

void printer_abort ( resource handle)

This function deletes the printers spool file.

handle must be a valid handle to a printer.

Example 1. printer_abort() example

$handle = printer_open();
printer_abort($handle);
printer_close($handle);

printer_close

(no version information, might be only in CVS)

printer_close -- Close an open printer connection

Description

void printer_close ( resource handle)

This function closes the printer connection. printer_close() also closes the active device context.

handle must be a valid handle to a printer.

Example 1. printer_close() example

$handle = printer_open();
printer_close($handle);

printer_create_brush

(no version information, might be only in CVS)

printer_create_brush -- Create a new brush

Description

mixed printer_create_brush ( int style, string color)

The function creates a new brush and returns a handle to it. A brush is used to fill shapes. For an example see printer_select_brush(). color must be a color in RGB hex format, i.e. "000000" for black, style must be one of the following constants:

PRINTER_BRUSH_SOLID: creates a brush with a solid color.
PRINTER_BRUSH_DIAGONAL: creates a brush with a 45-degree upward left-to-right hatch ( / ).
PRINTER_BRUSH_CROSS: creates a brush with a cross hatch ( + ).
PRINTER_BRUSH_DIAGCROSS: creates a brush with a 45 cross hatch ( x ).
PRINTER_BRUSH_FDIAGONAL: creates a brush with a 45-degree downward left-to-right hatch ( \ ).
PRINTER_BRUSH_HORIZONTAL: creates a brush with a horizontal hatch ( - ).
PRINTER_BRUSH_VERTICAL: creates a brush with a vertical hatch ( | ).
PRINTER_BRUSH_CUSTOM: creates a custom brush from an BMP file. The second parameter is used to specify the BMP instead of the RGB color code.

printer_create_dc

(no version information, might be only in CVS)

printer_create_dc -- Create a new device context

Description

void printer_create_dc ( resource handle)

The function creates a new device context. A device context is used to customize the graphic objects of the document. handle must be a valid handle to a printer.

Example 1. printer_create_dc() example

$handle = printer_open();
printer_start_doc($handle);
printer_start_page($handle);

printer_create_dc($handle);
/* do some stuff with the dc */
printer_set_option($handle, PRINTER_TEXT_COLOR, "333333");
printer_draw_text($handle, 1, 1, "text");
printer_delete_dc($handle);

/* create another dc */
printer_create_dc($handle);
printer_set_option($handle, PRINTER_TEXT_COLOR, "000000");
printer_draw_text($handle, 1, 1, "text");
/* do some stuff with the dc */

printer_delete_dc($handle);

printer_endpage($handle);
printer_end_doc($handle);
printer_close($handle);

printer_create_font

(no version information, might be only in CVS)

printer_create_font -- Create a new font

Description

mixed printer_create_font ( string face, int height, int width, int font_weight, bool italic, bool underline, bool strikeout, int orientaton)

The function creates a new font and returns a handle to it. A font is used to draw text. For an example see printer_select_font(). face must be a string specifying the font face. height specifies the font height, and width the font width. The font_weight specifies the font weight (400 is normal), and can be one of the following predefined constants.

PRINTER_FW_THIN: sets the font weight to thin (100).
PRINTER_FW_ULTRALIGHT: sets the font weight to ultra light (200).
PRINTER_FW_LIGHT: sets the font weight to light (300).
PRINTER_FW_NORMAL: sets the font weight to normal (400).
PRINTER_FW_MEDIUM: sets the font weight to medium (500).
PRINTER_FW_BOLD: sets the font weight to bold (700).
PRINTER_FW_ULTRABOLD: sets the font weight to ultra bold (800).
PRINTER_FW_HEAVY: sets the font weight to heavy (900).

italic can be TRUE or FALSE, and sets whether the font should be italic.

underline can be TRUE or FALSE, and sets whether the font should be underlined.

strikeout can be TRUE or FALSE, and sets whether the font should be striked out.

orientation specifies a rotation. For an example see printer_select_font().

printer_create_pen

(no version information, might be only in CVS)

printer_create_pen -- Create a new pen

Description

mixed printer_create_pen ( int style, int width, string color)

The function creates a new pen and returns a handle to it. A pen is used to draw lines and curves. For an example see printer_select_pen(). color must be a color in RGB hex format, i.e. "000000" for black, width specifies the width of the pen whereas style must be one of the following constants:

PRINTER_PEN_SOLID: creates a solid pen.
PRINTER_PEN_DASH: creates a dashed pen.
PRINTER_PEN_DOT: creates a dotted pen.
PRINTER_PEN_DASHDOT: creates a pen with dashes and dots.
PRINTER_PEN_DASHDOTDOT: creates a pen with dashes and double dots.
PRINTER_PEN_INVISIBLE: creates an invisible pen.

The function returns TRUE on success, or otherwise FALSE.

Example 1. printer_draw_bmp() example

$handle = printer_open();
printer_start_doc($handle, "My Document");
printer_start_page($handle);

printer_draw_bmp($handle, "c:\\image.bmp", 1, 1);

printer_end_page($handle);
printer_end_doc($handle);
printer_close($handle);

printer_draw_chord

(no version information, might be only in CVS)

printer_draw_chord -- Draw a chord

Description

void printer_draw_chord ( resource handle, int rec_x, int rec_y, int rec_x1, int rec_y1, int rad_x, int rad_y, int rad_x1, int rad_y1)

The function simply draws an chord. handle must be a valid handle to a printer.

rec_x is the upper left x coordinate of the bounding rectangle.

rec_y is the upper left y coordinate of the bounding rectangle.

rec_x1 is the lower right x coordinate of the bounding rectangle.

rec_y1 is the lower right y coordinate of the bounding rectangle.

rad_x is x coordinate of the radial defining the beginning of the chord.

rad_y is y coordinate of the radial defining the beginning of the chord.

rad_x1 is x coordinate of the radial defining the end of the chord.

rad_y1 is y coordinate of the radial defining the end of the chord.

Example 1. printer_draw_chord() example

$handle = printer_open();
printer_start_doc($handle, "My Document");
printer_start_page($handle);

$pen = printer_create_pen(PRINTER_PEN_SOLID, 2, "000000");
printer_select_pen($handle, $pen);

$brush = printer_create_brush(PRINTER_BRUSH_SOLID, "2222FF");
printer_select_brush($handle, $brush);

printer_draw_chord($handle, 1, 1, 500, 500, 1, 1, 500, 1);

printer_delete_brush($brush);
printer_delete_pen($pen);

printer_end_page($handle);
printer_end_doc($handle);
printer_close($handle);

printer_draw_elipse

(no version information, might be only in CVS)

printer_draw_elipse -- Draw an ellipse

Description

void printer_draw_elipse ( resource handle, int ul_x, int ul_y, int lr_x, int lr_y)

The function simply draws an ellipse. handle must be a valid handle to a printer.

ul_x is the upper left x coordinate of the ellipse.

ul_y is the upper left y coordinate of the ellipse.

lr_x is the lower right x coordinate of the ellipse.

lr_y is the lower right y coordinate of the ellipse.

Example 1. printer_draw_elipse() example

$handle = printer_open();
printer_start_doc($handle, "My Document");
printer_start_page($handle);

$pen = printer_create_pen(PRINTER_PEN_SOLID, 2, "000000");
printer_select_pen($handle, $pen);

$brush = printer_create_brush(PRINTER_BRUSH_SOLID, "2222FF");
printer_select_brush($handle, $brush);

printer_draw_elipse($handle, 1, 1, 500, 500);

printer_delete_brush($brush);
printer_delete_pen($pen);

printer_end_page($handle);
printer_end_doc($handle);
printer_close($handle);

printer_draw_line

(no version information, might be only in CVS)

printer_draw_line -- Draw a line

Description

void printer_draw_line ( resource printer_handle, int from_x, int from_y, int to_x, int to_y)

The function simply draws a line from position from_x, from_y to position to_x, to_y using the selected pen. printer_handle must be a valid handle to a printer.

Example 1. printer_draw_line() example

$handle = printer_open();
printer_start_doc($handle, "My Document");
printer_start_page($handle);

$pen = printer_create_pen(PRINTER_PEN_SOLID, 30, "000000");
printer_select_pen($handle, $pen);

printer_draw_line($handle, 1, 10, 1000, 10);
printer_draw_line($handle, 1, 60, 500, 60);

printer_delete_pen($pen);

printer_end_page($handle);
printer_end_doc($handle);
printer_close($handle);

printer_draw_pie

(no version information, might be only in CVS)

printer_draw_pie -- Draw a pie

Description

void printer_draw_pie ( resource handle, int rec_x, int rec_y, int rec_x1, int rec_y1, int rad1_x, int rad1_y, int rad2_x, int rad2_y)

The function simply draws an pie. handle must be a valid handle to a printer.

rec_x is the upper left x coordinate of the bounding rectangle.

rec_y is the upper left y coordinate of the bounding rectangle.

rec_x1 is the lower right x coordinate of the bounding rectangle.

rec_y1 is the lower right y coordinate of the bounding rectangle.

rad1_x is x coordinate of the first radial's ending.

rad1_y is y coordinate of the first radial's ending.

rad2_x is x coordinate of the second radial's ending.

rad2_y is y coordinate of the second radial's ending.

Example 1. printer_draw_pie() example

$handle = printer_open();
printer_start_doc($handle, "My Document");
printer_start_page($handle);

$pen = printer_create_pen(PRINTER_PEN_SOLID, 2, "000000");
printer_select_pen($handle, $pen);

$brush = printer_create_brush(PRINTER_BRUSH_SOLID, "2222FF");
printer_select_brush($handle, $brush);

printer_draw_pie($handle, 1, 1, 500, 500, 1, 1, 500, 1);

printer_delete_brush($brush);
printer_delete_pen($pen);

printer_end_page($handle);
printer_end_doc($handle);
printer_close($handle);

printer_draw_rectangle

(no version information, might be only in CVS)

printer_draw_rectangle -- Draw a rectangle

Description

void printer_draw_rectangle ( resource handle, int ul_x, int ul_y, int lr_x, int lr_y)

The function simply draws a rectangle.

handle must be a valid handle to a printer.

ul_x is the upper left x coordinate of the rectangle.

ul_y is the upper left y coordinate of the rectangle.

lr_x is the lower right x coordinate of the rectangle.

lr_y is the lower right y coordinate of the rectangle.

Example 1. printer_draw_rectangle() example

$handle = printer_open();
printer_start_doc($handle, "My Document");
printer_start_page($handle);

$pen = printer_create_pen(PRINTER_PEN_SOLID, 2, "000000");
printer_select_pen($handle, $pen);

$brush = printer_create_brush(PRINTER_BRUSH_SOLID, "2222FF");
printer_select_brush($handle, $brush);

printer_draw_rectangle($handle, 1, 1, 500, 500);

printer_delete_brush($brush);
printer_delete_pen($pen);

printer_end_page($handle);
printer_end_doc($handle);
printer_close($handle);

printer_draw_roundrect

(no version information, might be only in CVS)

printer_draw_roundrect -- Draw a rectangle with rounded corners

Description

void printer_draw_roundrect ( resource handle, int ul_x, int ul_y, int lr_x, int lr_y, int width, int height)

The function simply draws a rectangle with rounded corners.

handle must be a valid handle to a printer.

ul_x is the upper left x coordinate of the rectangle.

ul_y is the upper left y coordinate of the rectangle.

lr_x is the lower right x coordinate of the rectangle.

lr_y is the lower right y coordinate of the rectangle.

width is the width of the ellipse.

height is the height of the ellipse.

Example 1. printer_draw_roundrect() example

$handle = printer_open();
printer_start_doc($handle, "My Document");
printer_start_page($handle);

$pen = printer_create_pen(PRINTER_PEN_SOLID, 2, "000000");
printer_select_pen($handle, $pen);

$brush = printer_create_brush(PRINTER_BRUSH_SOLID, "2222FF");
printer_select_brush($handle, $brush);

printer_draw_roundrect($handle, 1, 1, 500, 500, 200, 200);

printer_delete_brush($brush);
printer_delete_pen($pen);

printer_end_page($handle);
printer_end_doc($handle);
printer_close($handle);

printer_draw_text

(no version information, might be only in CVS)

printer_draw_text -- Draw text

Description

void printer_draw_text ( resource printer_handle, string text, int x, int y)

The function simply draws text at position x, y using the selected font. printer_handle must be a valid handle to a printer.

Example 1. printer_draw_text() example

$handle = printer_open();
printer_start_doc($handle, "My Document");
printer_start_page($handle);

$font = printer_create_font("Arial",72,48,400,false,false,false,0);
printer_select_font($handle, $font);
printer_draw_text($handle, "test", 10, 10);
printer_delete_font($font);

printer_end_page($handle);
printer_end_doc($handle);
printer_close($handle);

PRINTER_DEVICENAME returns the devicename of the printer.
PRINTER_DRIVERVERSION returns the printer driver version.

Example 1. printer_get_option() example

$handle = printer_open();
print printer_get_option($handle, PRINTER_DRIVERVERSION);
printer_close($handle);

printer_list

(no version information, might be only in CVS)

printer_list -- Return an array of printers attached to the server

Description

array printer_list ( int enumtype [, string name [, int level]])

The function enumerates available printers and their capabilities. level sets the level of information request. Can be 1,2,4 or 5. enumtype must be one of the following predefined constants:

PRINTER_ENUM_LOCAL: enumerates the locally installed printers.
PRINTER_ENUM_NAME: enumerates the printer of name, can be a server, domain or print provider.
PRINTER_ENUM_SHARED: this parameter can't be used alone, it has to be OR'ed with other parameters, i.e. PRINTER_ENUM_LOCAL to detect the locally shared printers.
PRINTER_ENUM_DEFAULT: (Win9.x only) enumerates the default printer.
PRINTER_ENUM_CONNECTIONS: (WinNT/2000 only) enumerates the printers to which the user has made connections.
PRINTER_ENUM_NETWORK: (WinNT/2000 only) enumerates network printers in the computer's domain. Only valid if level is 1.
PRINTER_ENUM_REMOTE: (WinNT/2000 only) enumerates network printers and print servers in the computer's domain. Only valid if level is 1.

Example 1. printer_list() example

/* detect locally shared printer */
var_dump( printer_list(PRINTER_ENUM_LOCAL | PRINTER_ENUM_SHARED) );

printer_logical_fontheight

(no version information, might be only in CVS)

printer_logical_fontheight -- Get logical font height

Description

int printer_logical_fontheight ( resource handle, int height)

The function calculates the logical font height of height. handle must be a valid handle to a printer.

Example 1. printer_logical_fontheight() example

$handle = printer_open();
print printer_logical_fontheight($handle, 72);
printer_close($handle);

printer_open

(no version information, might be only in CVS)

printer_open -- Open connection to a printer

Description

mixed printer_open ( [string devicename])

This function tries to open a connection to the printer devicename, and returns a handle on success or FALSE on failure.

If no parameter was given it tries to open a connection to the default printer (if not specified in php.ini as printer.default_printer, php tries to detect it).

printer_open() also starts a device context.

Example 1. printer_open() example

$handle = printer_open("HP Deskjet 930c");
$handle = printer_open();

printer_select_brush

(no version information, might be only in CVS)

printer_select_brush -- Select a brush

Description

void printer_select_brush ( resource printer_handle, resource brush_handle)

The function selects a brush as the active drawing object of the actual device context. A brush is used to fill shapes. If you draw an rectangle the brush is used to draw the shapes, while the pen is used to draw the border. If you haven't selected a brush before drawing shapes, the shape won't be filled. printer_handle must be a valid handle to a printer. brush_handle must be a valid handle to a brush.

Example 1. printer_select_brush() example

$handle = printer_open();
printer_start_doc($handle, "My Document");
printer_start_page($handle);

$pen = printer_create_pen(PRINTER_PEN_SOLID, 2, "000000");
printer_select_pen($handle, $pen);
$brush = printer_create_brush(PRINTER_BRUSH_CUSTOM, "c:\\brush.bmp");
printer_select_brush($handle, $brush);

printer_draw_rectangle($handle, 1,1,500,500);

printer_delete_brush($brush);

$brush = printer_create_brush(PRINTER_BRUSH_SOLID, "000000");
printer_select_brush($handle, $brush);
printer_draw_rectangle($handle, 1,501,500,1001);
printer_delete_brush($brush);

printer_delete_pen($pen);

printer_end_page($handle);
printer_end_doc($handle);
printer_close($handle);

printer_select_font

(no version information, might be only in CVS)

printer_select_font -- Select a font

Description

void printer_select_font ( resource printer_handle, resource font_handle)

The function selects a font to draw text. printer_handle must be a valid handle to a printer. font_handle must be a valid handle to a font.

Example 1. printer_select_font() example

$handle = printer_open();
printer_start_doc($handle, "My Document");
printer_start_page($handle);

$font = printer_create_font("Arial", 148, 76, PRINTER_FW_MEDIUM, false, false, false, -50);
printer_select_font($handle, $font);
printer_draw_text($handle, "PHP is simply cool", 40, 40);
printer_delete_font($font);

printer_end_page($handle);
printer_end_doc($handle);
printer_close($handle);

printer_select_pen

(no version information, might be only in CVS)

printer_select_pen -- Select a pen

Description

void printer_select_pen ( resource printer_handle, resource pen_handle)

The function selects a pen as the active drawing object of the actual device context. A pen is used to draw lines and curves. I.e. if you draw a single line the pen is used. If you draw an rectangle the pen is used to draw the borders, while the brush is used to fill the shape. If you haven't selected a pen before drawing shapes, the shape won't be outlined. printer_handle must be a valid handle to a printer. pen_handle must be a valid handle to a pen.

Example 1. printer_select_pen() example

$handle = printer_open();
printer_start_doc($handle, "My Document");
printer_start_page($handle);

$pen = printer_create_pen(PRINTER_PEN_SOLID, 30, "2222FF");
printer_select_pen($handle, $pen);

printer_draw_line($handle, 1, 60, 500, 60);

printer_delete_pen($pen);

printer_end_page($handle);
printer_end_doc($handle);
printer_close($handle);

printer_set_option

(no version information, might be only in CVS)

printer_set_option -- Configure the printer connection

Description

bool printer_set_option ( resource handle, int option, mixed value)

The function sets the following options for the current connection. handle must be a valid handle to a printer. For option can be one of the following constants:

PRINTER_COPIES: sets how many copies should be printed, value must be an integer.
PRINTER_MODE: specifies the type of data (text, raw or emf), value must be a string.
PRINTER_TITLE: specifies the name of the document, value must be a string.
PRINTER_ORIENTATION: specifies the orientation of the paper, value can be either PRINTER_ORIENTATION_PORTRAIT or PRINTER_ORIENTATION_LANDSCAPE
PRINTER_RESOLUTION_Y: specifies the y-resolution in DPI, value must be an integer.
PRINTER_RESOLUTION_X: specifies the x-resolution in DPI, value must be an integer.
PRINTER_PAPER_FORMAT: specifies the a predefined paper format, set value to PRINTER_FORMAT_CUSTOM if you want to specify a custom format with PRINTER_PAPER_WIDTH and PRINTER_PAPER_LENGTH. value can be one of the following constants.
- PRINTER_FORMAT_CUSTOM: let's you specify a custom paper format.
- PRINTER_FORMAT_LETTER: specifies standard letter format (8 1/2- by 11-inches).
- PRINTER_FORMAT_LETTER: specifies standard legal format (8 1/2- by 14-inches).
- PRINTER_FORMAT_A3: specifies standard A3 format (297- by 420-millimeters).
- PRINTER_FORMAT_A4: specifies standard A4 format (210- by 297-millimeters).
- PRINTER_FORMAT_A5: specifies standard A5 format (148- by 210-millimeters).
- PRINTER_FORMAT_B4: specifies standard B4 format (250- by 354-millimeters).
- PRINTER_FORMAT_B5: specifies standard B5 format (182- by 257-millimeter).
- PRINTER_FORMAT_FOLIO: specifies standard FOLIO format (8 1/2- by 13-inch).
PRINTER_PAPER_LENGTH: if PRINTER_PAPER_FORMAT is set to PRINTER_FORMAT_CUSTOM, PRINTER_PAPER_LENGTH specifies a custom paper length in mm, value must be an integer.
PRINTER_PAPER_WIDTH: if PRINTER_PAPER_FORMAT is set to PRINTER_FORMAT_CUSTOM, PRINTER_PAPER_WIDTH specifies a custom paper width in mm, value must be an integer.
PRINTER_SCALE: specifies the factor by which the printed output is to be scaled. the page size is scaled from the physical page size by a factor of scale/100. for example if you set the scale to 50, the output would be half of it's original size. value must be an integer.
PRINTER_BACKGROUND_COLOR: specifies the background color for the actual device context, value must be a string containing the rgb information in hex format i.e. "005533".
PRINTER_TEXT_COLOR: specifies the text color for the actual device context, value must be a string containing the rgb information in hex format i.e. "005533".
PRINTER_TEXT_ALIGN: specifies the text alignment for the actual device context, value can be combined through OR'ing the following constants:
- PRINTER_TA_BASELINE: text will be aligned at the base line.
- PRINTER_TA_BOTTOM: text will be aligned at the bottom.
- PRINTER_TA_TOP: text will be aligned at the top.
- PRINTER_TA_CENTER: text will be aligned at the center.
- PRINTER_TA_LEFT: text will be aligned at the left.
- PRINTER_TA_RIGHT: text will be aligned at the right.

Example 1. printer_set_option() example

$handle = printer_open();
printer_set_option($handle, PRINTER_SCALE, 75);
printer_set_option($handle, PRINTER_TEXT_ALIGN, PRINTER_TA_LEFT);
printer_close($handle);

printer_start_doc

(no version information, might be only in CVS)

printer_start_doc -- Start a new document

Description

bool printer_start_doc ( resource handle [, string document])

The function creates a new document in the printer spooler. A document can contain multiple pages, it's used to schedule the print job in the spooler. handle must be a valid handle to a printer. The optional parameter document can be used to set an alternative document name.

Example 1. printer_start_doc() example

$handle = printer_open();
printer_start_doc($handle, "My Document");
printer_start_page($handle);

printer_end_page($handle);
printer_end_doc($handle);
printer_close($handle);

printer_start_page

(no version information, might be only in CVS)

printer_start_page -- Start a new page

Description

bool printer_start_page ( resource handle)

The function creates a new page in the active document. For an example see printer_start_doc(). handle must be a valid handle to a printer.

printer_write

(no version information, might be only in CVS)

printer_write -- Write data to the printer

Description

bool printer_write ( resource handle, string content)

Writes content directly to the printer, and returns TRUE on success or FALSE if it failed.

handle must be a valid handle to a printer.

Example 1. printer_write() example

$handle = printer_open();
printer_write($handle, "Text to print");
printer_close($handle);

LXXXV. Pspell Functions

Introduction

These functions allow you to check the spelling of a word and offer suggestions.

Requirements

To compile PHP with pspell support, you need the aspell and pspell libraries, available from http://aspell.sourceforge.net/ and http://aspell.net/ respectively.

Installation

If you have the libraries needed add the --with-pspell[=dir] option when compiling PHP.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

PSPELL_FAST (integer)
PSPELL_NORMAL (integer)
PSPELL_BAD_SPELLERS (integer)
PSPELL_RUN_TOGETHER (integer)

Table of Contents
pspell_add_to_personal -- Add the word to a personal wordlist
pspell_add_to_session -- Add the word to the wordlist in the current session
pspell_check -- Check a word
pspell_clear_session -- Clear the current session
pspell_config_create -- Create a config used to open a dictionary
pspell_config_ignore -- Ignore words less than N characters long
pspell_config_mode -- Change the mode number of suggestions returned
pspell_config_personal -- Set a file that contains personal wordlist
pspell_config_repl -- Set a file that contains replacement pairs
pspell_config_runtogether -- Consider run-together words as valid compounds
pspell_config_save_repl -- Determine whether to save a replacement pairs list along with the wordlist
pspell_new_config -- Load a new dictionary with settings based on a given config
pspell_new_personal -- Load a new dictionary with personal wordlist
pspell_new -- Load a new dictionary
pspell_save_wordlist -- Save the personal wordlist to a file
pspell_store_replacement -- Store a replacement pair for a word
pspell_suggest -- Suggest spellings of a word

pspell_add_to_personal

(PHP 4 >= 4.0.2)

pspell_add_to_personal -- Add the word to a personal wordlist

Description

int pspell_add_to_personal ( int dictionary_link, string word)

pspell_add_to_personal() adds a word to the personal wordlist. If you used pspell_new_config() with pspell_config_personal() to open the dictionary, you can save the wordlist later with pspell_save_wordlist(). Please, note that this function will not work unless you have pspell .11.2 and aspell .32.5 or later.

Example 1. pspell_add_to_personal()
$pspell_config = pspell_config_create ("en"); pspell_config_personal ($pspell_config, "/var/dictionaries/custom.pws"); $pspell_link = pspell_new_config ($pspell_config); pspell_add_to_personal ($pspell_link, "Vlad"); pspell_save_wordlist ($pspell_link);

pspell_add_to_session

(PHP 4 >= 4.0.2)

pspell_add_to_session -- Add the word to the wordlist in the current session

Description

int pspell_add_to_session ( int dictionary_link, string word)

pspell_add_to_session() adds a word to the wordlist associated with the current session. It is very similar to pspell_add_to_personal()

pspell_check

(PHP 4 >= 4.0.2)

pspell_check -- Check a word

Description

bool pspell_check ( int dictionary_link, string word)

pspell_check() checks the spelling of a word and returns TRUE if the spelling is correct, FALSE if not.

Example 1. pspell_check()
$pspell_link = pspell_new ("en"); if (pspell_check ($pspell_link, "testt")) { echo "This is a valid spelling"; } else { echo "Sorry, wrong spelling"; }

pspell_clear_session

(PHP 4 >= 4.0.2)

pspell_clear_session -- Clear the current session

Description

int pspell_clear_session ( int dictionary_link)

pspell_clear_session() clears the current session. The current wordlist becomes blank, and, for example, if you try to save it with pspell_save_wordlist(), nothing happens.

pspell_config_create

(PHP 4 >= 4.0.2)

pspell_config_create -- Create a config used to open a dictionary

Description

int pspell_config_create ( string language [, string spelling [, string jargon [, string encoding]]])

pspell_config_create() has a very similar syntax to pspell_new(). In fact, using pspell_config_create() immediatelly followed by pspell_new_config() will produce the exact same result. However, after creating a new config, you can also use pspell_config_*() functions before calling pspell_new_config() to take advantage of some advanced functionality.

The language parameter is the language code which consists of the two letter ISO 639 language code and an optional two letter ISO 3166 country code after a dash or underscore.

The spelling parameter is the requested spelling for languages with more than one spelling such as English. Known values are 'american', 'british', and 'canadian'.

The jargon parameter contains extra information to distinguish two different words lists that have the same language and spelling parameters.

The encoding parameter is the encoding that words are expected to be in. Valid values are 'utf-8', 'iso8859-*', 'koi8-r', 'viscii', 'cp1252', 'machine unsigned 16', 'machine unsigned 32'. This parameter is largely untested, so be careful when using.

The mode parameter is the mode in which spellchecker will work. There are several modes available:

PSPELL_FAST - Fast mode (least number of suggestions)
PSPELL_NORMAL - Normal mode (more suggestions)
PSPELL_BAD_SPELLERS - Slow mode (a lot of suggestions)

For more information and examples, check out inline manual pspell website:http://aspell.net/.

Example 1. pspell_config_create()
$pspell_config = pspell_config_create ("en"); pspell_config_personal ($pspell_config, "/var/dictionaries/custom.pws"); pspell_config_repl ($pspell_config, "/var/dictionaries/custom.repl"); $pspell_link = pspell_new_personal ($pspell_config, "en");

pspell_config_ignore

(PHP 4 >= 4.0.2)

pspell_config_ignore -- Ignore words less than N characters long

Description

int pspell_config_ignore ( int dictionary_link, int n)

pspell_config_ignore() should be used on a config before calling pspell_new_config(). This function allows short words to be skipped by the spellchecker. Words less then n characters will be skipped.

Example 1. pspell_config_ignore()
$pspell_config = pspell_config_create ("en"); pspell_config_ignore($pspell_config, 5); $pspell_link = pspell_new_config($pspell_config); pspell_check($pspell_link, "abcd"); //will not result in an error

pspell_config_mode

(PHP 4 >= 4.0.2)

pspell_config_mode -- Change the mode number of suggestions returned

Description

int pspell_config_mode ( int dictionary_link, int mode)

pspell_config_mode() should be used on a config before calling pspell_new_config(). This function determines how many suggestions will be returned by pspell_suggest().

The mode parameter is the mode in which spellchecker will work. There are several modes available:

PSPELL_FAST - Fast mode (least number of suggestions)
PSPELL_NORMAL - Normal mode (more suggestions)
PSPELL_BAD_SPELLERS - Slow mode (a lot of suggestions)

pspell_new_config

(PHP 4 >= 4.0.2)

pspell_new_config -- Load a new dictionary with settings based on a given config

Description

int pspell_new_config ( int config)

pspell_new_config() opens up a new dictionary with settings specified in a config, created with with pspell_config_create() and modified with pspell_config_*() functions. This method provides you with the most flexibility and has all the functionality provided by pspell_new() and pspell_new_personal().

The config parameter is the one returned by pspell_config_create() when the config was created.

Example 1. pspell_new_config()
$pspell_config = pspell_config_create ("en"); pspell_config_personal ($pspell_config, "/var/dictionaries/custom.pws"); pspell_config_repl ($pspell_config, "/var/dictionaries/custom.repl"); $pspell_link = pspell_new_config ($pspell_config);

pspell_new_personal

(PHP 4 >= 4.0.2)

pspell_new_personal -- Load a new dictionary with personal wordlist

Description

int pspell_new_personal ( string personal, string language [, string spelling [, string jargon [, string encoding [, int mode]]]])

pspell_new_personal() opens up a new dictionary with a personal wordlist and returns the dictionary link identifier for use in other pspell functions. The wordlist can be modified and saved with pspell_save_wordlist(), if desired. However, the replacement pairs are not saved. In order to save replacement pairs, you should create a config using pspell_config_create(), set the personal wordlist file with pspell_config_personal(), set the file for replacement pairs with pspell_config_repl(), and open a new dictionary with pspell_new_config().

The personal parameter specifies the file where words added to the personal list will be stored. It should be an absolute filename beginning with '/' because otherwise it will be relative to $HOME, which is "/root" for most systems, and is probably not what you want.

The language parameter is the language code which consists of the two letter ISO 639 language code and an optional two letter ISO 3166 country code after a dash or underscore.

The spelling parameter is the requested spelling for languages with more than one spelling such as English. Known values are 'american', 'british', and 'canadian'.

The jargon parameter contains extra information to distinguish two different words lists that have the same language and spelling parameters.

The mode parameter is the mode in which spellchecker will work. There are several modes available:

PSPELL_FAST - Fast mode (least number of suggestions)
PSPELL_NORMAL - Normal mode (more suggestions)
PSPELL_BAD_SPELLERS - Slow mode (a lot of suggestions)
PSPELL_RUN_TOGETHER - Consider run-together words as legal compounds. That is, "thecat" will be a legal compound, athough there should be a space between the two words. Changing this setting only affects the results returned by pspell_check(); pspell_suggest() will still return suggestions.

Mode is a bitmask constructed from different constants listed above. However, PSPELL_FAST, PSPELL_NORMAL and PSPELL_BAD_SPELLERS are mutually exclusive, so you should select only one of them.

For more information and examples, check out inline manual pspell website:http://aspell.net/.

Example 1. pspell_new_personal()
$pspell_link = pspell_new_personal ("/var/dictionaries/custom.pws", "en", "", "", "", PSPELL_FAST|PSPELL_RUN_TOGETHER));

pspell_new

(PHP 4 >= 4.0.2)

pspell_new -- Load a new dictionary

Description

int pspell_new ( string language [, string spelling [, string jargon [, string encoding [, int mode]]]])

pspell_new() opens up a new dictionary and returns the dictionary link identifier for use in other pspell functions.

The language parameter is the language code which consists of the two letter ISO 639 language code and an optional two letter ISO 3166 country code after a dash or underscore.

The spelling parameter is the requested spelling for languages with more than one spelling such as English. Known values are 'american', 'british', and 'canadian'.

The jargon parameter contains extra information to distinguish two different words lists that have the same language and spelling parameters.

The mode parameter is the mode in which spellchecker will work. There are several modes available:

PSPELL_FAST - Fast mode (least number of suggestions)
PSPELL_NORMAL - Normal mode (more suggestions)
PSPELL_BAD_SPELLERS - Slow mode (a lot of suggestions)
PSPELL_RUN_TOGETHER - Consider run-together words as legal compounds. That is, "thecat" will be a legal compound, athough there should be a space between the two words. Changing this setting only affects the results returned by pspell_check(); pspell_suggest() will still return suggestions.

Mode is a bitmask constructed from different constants listed above. However, PSPELL_FAST, PSPELL_NORMAL and PSPELL_BAD_SPELLERS are mutually exclusive, so you should select only one of them.

For more information and examples, check out inline manual pspell website:http://aspell.net/.

Example 1. pspell_new()
$pspell_link = pspell_new ("en", "", "", "", (PSPELL_FAST|PSPELL_RUN_TOGETHER));

pspell_save_wordlist

(PHP 4 >= 4.0.2)

pspell_save_wordlist -- Save the personal wordlist to a file

Description

int pspell_save_wordlist ( int dictionary_link)

pspell_save_wordlist() saves the personal wordlist from the current session. The dictionary has to be open with pspell_new_personal(), and the location of files to be saved specified with pspell_config_personal() and (optionally) pspell_config_repl(). Please, note that this function will not work unless you have pspell .11.2 and aspell .32.5 or later.

Example 1. pspell_add_to_personal()
$pspell_config = pspell_config_create ("en"); pspell_config_personal ($pspell_config, "/tmp/dicts/newdict"); $pspell_link = pspell_new_config ($pspell_config); pspell_add_to_personal ($pspell_link, "Vlad"); pspell_save_wordlist ($pspell_link);

pspell_store_replacement

(PHP 4 >= 4.0.2)

pspell_store_replacement -- Store a replacement pair for a word

Description

int pspell_store_replacement ( int dictionary_link, string misspelled, string correct)

pspell_store_replacement() stores a replacement pair for a word, so that replacement can be returned by pspell_suggest() later. In order to be able to take advantage of this function, you have to use pspell_new_personal() to open the dictionary. In order to permanently save the replacement pair, you have to use pspell_config_personal() and pspell_config_repl() to set the path where to save your custom wordlists, and then use pspell_save_wordlist() for the changes to be written to disk. Please, note that this function will not work unless you have pspell .11.2 and aspell .32.5 or later.

Example 1. pspell_store_replacement()
$pspell_config = pspell_config_create ("en"); pspell_config_personal ($pspell_config, "/var/dictionaries/custom.pws"); pspell_config_repl ($pspell_config, "/var/dictionaries/custom.repl"); $pspell_link = pspell_new_config ($pspell_config); pspell_store_replacement ($pspell_link, $misspelled, $correct); pspell_save_wordlist ($pspell_link);

pspell_suggest

(PHP 4 >= 4.0.2)

pspell_suggest -- Suggest spellings of a word

Description

array pspell_suggest ( int dictionary_link, string word)

pspell_suggest() returns an array of possible spellings for the given word.

Example 1. pspell_suggest()
$pspell_link = pspell_new ("en"); if (!pspell_check ($pspell_link, "testt")) { $suggestions = pspell_suggest ($pspell_link, "testt"); foreach ($suggestions as $suggestion) { echo "Possible spelling: $suggestion<br>"; } }

LXXXVI. GNU Readline

Introduction

The readline() functions implement an interface to the GNU Readline library. These are functions that provide editable command lines. An example being the way Bash allows you to use the arrow keys to insert characters or scroll through command history. Because of the interactive nature of this library, it will be of little use for writing Web applications, but may be useful when writing scripts meant to be run from a shell.

Requirements

To use the readline functions, you need to install libreadline. You can find libreadline on the home page of the GNU Readline project, at http://cnswww.cns.cwru.edu/~chet/readline/rltop.html. It's maintained by Chet Ramey, who's also the author of Bash.

Installation

To use this functions you must compile PHP with readline support. You need to configure PHP --with-readline.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Table of Contents
readline_add_history -- Adds a line to the history
readline_clear_history -- Clears the history
readline_completion_function -- Registers a completion function
readline_info -- Gets/sets various internal readline variables
readline_list_history -- Lists the history
readline_read_history -- Reads the history
readline_write_history -- Writes the history
readline -- Reads a line

This function returns a single string from the user. You may specify a string with which to prompt the user. The line returned has the ending newline removed. You must add this line to the history yourself using readline_add_history().

Example 1. readline()

//get 3 commands from user
for ($i=0; $i < 3; $i++) {
        $line = readline ("Command: ");
        readline_add_history ($line);
}

//dump history
print_r (readline_list_history());

//dump variables
print_r (readline_info());

LXXXVII. GNU Recode functions

Introduction

This module contains an interface to the GNU Recode library, version 3.5. The GNU Recode library converts files between various coded character sets and surface encodings. When this cannot be achieved exactly, it may get rid of the offending characters or fall back on approximations. The library recognises or produces nearly 150 different character sets and is able to convert files between almost any pair. Most RFC 1345 character sets are supported.

Requirements

You must have GNU Recode 3.5 or higher installed on your system. You can download the package from here.

Installation

To be able to use the functions defined in this module you must compile your PHP interpreter using the --with-recode[=DIR] option.

Warning

Crashes and startup problems of PHP may be encountered when loading the recode as extension after loading any extension of mysql or imap. Loading the recode before those extension has proven to fix the problem. This is due a technical problem that both the c-client library used by imap and recode have their own hash_lookup() function and both mysql and recode have their own hash_insert function.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Table of Contents
recode_file -- Recode from file to file according to recode request
recode_string -- Recode a string according to a recode request
recode -- Recode a string according to a recode request

recode_file

(PHP 3>= 3.0.13, PHP 4 )

recode_file -- Recode from file to file according to recode request

Description

bool recode_file ( string request, resource input, resource output)

Recode the file referenced by file handle input into the file referenced by file handle output according to the recode request. Returns FALSE, if unable to comply, TRUE otherwise.

This function does not currently process filehandles referencing remote files (URLs). Both filehandles must refer to local files.

Example 1. Basic recode_file() example
$input = fopen ('input.txt', 'r'); $output = fopen ('output.txt', 'w'); recode_file ("us..flat", $input, $output);

recode_string

(PHP 3>= 3.0.13, PHP 4 )

recode_string -- Recode a string according to a recode request

Description

string recode_string ( string request, string string)

Recode the string string according to the recode request request. Returns the recoded string or FALSE, if unable to perform the recode request.

A simple recode request may be "lat1..iso646-de". See also the GNU Recode documentation of your installation for detailed instructions about recode requests.
Example 1. Basic recode_string() example:
print recode_string ("us..flat", "The following character has a diacritical mark: á");

recode

(PHP 4 )

recode -- Recode a string according to a recode request

Description

string recode ( string request, string string)

Note: This is an alias for recode_string(). It has been added in PHP 4.

LXXXVIII. Regular Expression Functions (Perl-Compatible)

Introduction

The syntax for patterns used in these functions closely resembles Perl. The expression should be enclosed in the delimiters, a forward slash (/), for example. Any character can be used for delimiter as long as it's not alphanumeric or backslash (\). If the delimiter character has to be used in the expression itself, it needs to be escaped by backslash. Since PHP 4.0.4, you can also use Perl-style (), {}, [], and <> matching delimiters.

The ending delimiter may be followed by various modifiers that affect the matching. See Pattern Modifiers.

PHP also supports regular expressions using a POSIX-extended syntax using the POSIX-extended regex functions..

Requirements

Regular expression support is provided by the PCRE library package, which is open source software, written by Philip Hazel, and copyright by the University of Cambridge, England. It is available at ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/.

Installation

Beginning with PHP 4.2.0 this function are enabled by default. For older versions you have to configure and compile PHP with --with-pcre-regex[=DIR] in order to use these functions. You can disable the pcre functions with --without-pcre-regex.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

Table 1. PREG constants

constant	description
PREG_PATTERN_ORDER	Orders results so that $matches[0] is an array of full pattern matches, $matches[1] is an array of strings matched by the first parenthesized subpattern, and so on. This flag is only used with preg_match_all().
PREG_SET_ORDER	Orders results so that $matches[0] is an array of first set of matches, $matches[1] is an array of second set of matches, and so on. This flag is only used with preg_match_all().
PREG_OFFSET_CAPTURE	See the description of `PREG_SPLIT_OFFSET_CAPTURE`. This flag is available since `PHP` 4.3.0 .
PREG_SPLIT_NO_EMPTY	This flag tells preg_split() to only return only non-empty pieces.
PREG_SPLIT_DELIM_CAPTURE	This flag tells preg_split() to capture parenthesized expression in the delimiter pattern as well. This flag is available since `PHP` 4.0.5 .
PREG_SPLIT_OFFSET_CAPTURE	If this flag is set, for every occuring match the appendant string offset will also be returned. Note that this changes the return value in an array where very element is an array consisting of the matched string at offset 0 and it's string offset into subject at offset 1. This flag is available since `PHP` 4.3.0 and is only used for preg_split().

Examples

Example 1. Examples of valid patterns
/<\/\w+>/
|(\d{3})-\d+|Sm
/^(?i)php[34]/
{^\s+(\s+)?$}

Example 2. Examples of invalid patterns
/href='(.*)' - missing ending delimiter
/\w+\s*\w+/J - unknown modifier 'J'
1-\d3-\d3-\d4| - missing starting delimiter

Table of Contents
Pattern Modifiers -- Describes possible modifiers in regex patterns
Pattern Syntax -- Describes PCRE regex syntax
preg_grep -- Return array entries that match the pattern
preg_match_all -- Perform a global regular expression match
preg_match -- Perform a regular expression match
preg_quote -- Quote regular expression characters
preg_replace_callback -- Perform a regular expression search and replace using a callback
preg_replace -- Perform a regular expression search and replace
preg_split -- Split string by a regular expression

Pattern Modifiers

Pattern Modifiers -- Describes possible modifiers in regex patterns

Description

The current possible PCRE modifiers are listed below. The names in parentheses refer to internal PCRE names for these modifiers.

i (PCRE_CASELESS)
If this modifier is set, letters in the pattern match both upper and lower case letters.
m (PCRE_MULTILINE)
By default, PCRE treats the subject string as consisting of a single "line" of characters (even if it actually contains several newlines). The "start of line" metacharacter (^) matches only at the start of the string, while the "end of line" metacharacter ($) matches only at the end of the string, or before a terminating newline (unless D modifier is set). This is the same as Perl.
When this modifier is set, the "start of line" and "end of line" constructs match immediately following or immediately before any newline in the subject string, respectively, as well as at the very start and end. This is equivalent to Perl's /m modifier. If there are no "\n" characters in a subject string, or no occurrences of ^ or $ in a pattern, setting this modifier has no effect.
s (PCRE_DOTALL)
If this modifier is set, a dot metacharacter in the pattern matches all characters, including newlines. Without it, newlines are excluded. This modifier is equivalent to Perl's /s modifier. A negative class such as [^a] always matches a newline character, independent of the setting of this modifier.
x (PCRE_EXTENDED)
If this modifier is set, whitespace data characters in the pattern are totally ignored except when escaped or inside a character class, and characters between an unescaped # outside a character class and the next newline character, inclusive, are also ignored. This is equivalent to Perl's /x modifier, and makes it possible to include comments inside complicated patterns. Note, however, that this applies only to data characters. Whitespace characters may never appear within special character sequences in a pattern, for example within the sequence (?( which introduces a conditional subpattern.
e
If this modifier is set, preg_replace() does normal substitution of backreferences in the replacement string, evaluates it as PHP code, and uses the result for replacing the search string.
Only preg_replace() uses this modifier; it is ignored by other PCRE functions.
Note: This modifier was not available in PHP3.
A (PCRE_ANCHORED)
If this modifier is set, the pattern is forced to be "anchored", that is, it is constrained to match only at the start of the string which is being searched (the "subject string"). This effect can also be achieved by appropriate constructs in the pattern itself, which is the only way to do it in Perl.
D (PCRE_DOLLAR_ENDONLY)
If this modifier is set, a dollar metacharacter in the pattern matches only at the end of the subject string. Without this modifier, a dollar also matches immediately before the final character if it is a newline (but not before any other newlines). This modifier is ignored if m modifier is set. There is no equivalent to this modifier in Perl.
S
When a pattern is going to be used several times, it is worth spending more time analyzing it in order to speed up the time taken for matching. If this modifier is set, then this extra analysis is performed. At present, studying a pattern is useful only for non-anchored patterns that do not have a single fixed starting character.
U (PCRE_UNGREEDY)
This modifier inverts the "greediness" of the quantifiers so that they are not greedy by default, but become greedy if followed by "?". It is not compatible with Perl. It can also be set by a (?U) modifier setting within the pattern.
X (PCRE_EXTRA)
This modifier turns on additional functionality of PCRE that is incompatible with Perl. Any backslash in a pattern that is followed by a letter that has no special meaning causes an error, thus reserving these combinations for future expansion. By default, as in Perl, a backslash followed by a letter with no special meaning is treated as a literal. There are at present no other features controlled by this modifier.
u (PCRE_UTF8)
This modifier turns on additional functionality of PCRE that is incompatible with Perl. Pattern strings are treated as UTF-8. This modifier is available from PHP 4.1.0 or greater on Unix and from PHP 4.2.3 on win32.

Pattern Syntax

Pattern Syntax -- Describes PCRE regex syntax

Description

The PCRE library is a set of functions that implement regular expression pattern matching using the same syntax and semantics as Perl 5, with just a few differences (see below). The current implementation corresponds to Perl 5.005.

Differences From Perl

The differences described here are with respect to Perl 5.005.

By default, a whitespace character is any character that the C library function isspace() recognizes, though it is possible to compile PCRE with alternative character type tables. Normally isspace() matches space, formfeed, newline, carriage return, horizontal tab, and vertical tab. Perl 5 no longer includes vertical tab in its set of whitespace characters. The \v escape that was in the Perl documentation for a long time was never in fact recognized. However, the character itself was treated as whitespace at least up to 5.002. In 5.004 and 5.005 it does not match \s.
PCRE does not allow repeat quantifiers on lookahead assertions. Perl permits them, but they do not mean what you might think. For example, (?!a){3} does not assert that the next three characters are not "a". It just asserts that the next character is not "a" three times.
Capturing subpatterns that occur inside negative looka- head assertions are counted, but their entries in the offsets vector are never set. Perl sets its numerical vari- ables from any such patterns that are matched before the assertion fails to match something (thereby succeeding), but only if the negative lookahead assertion contains just one branch.
Though binary zero characters are supported in the subject string, they are not allowed in a pattern string because it is passed as a normal C string, terminated by zero. The escape sequence "\\x00" can be used in the pattern to represent a binary zero.
The following Perl escape sequences are not supported: \l, \u, \L, \U, \E, \Q. In fact these are implemented by Perl's general string-handling and are not part of its pat- tern matching engine.
The Perl \G assertion is not supported as it is not relevant to single pattern matches.
Fairly obviously, PCRE does not support the (?{code}) construction.
There are at the time of writing some oddities in Perl 5.005_02 concerned with the settings of captured strings when part of a pattern is repeated. For example, matching "aba" against the pattern /^(a(b)?)+$/ sets $2 to the value "b", but matching "aabbaa" against /^(aa(bb)?)+$/ leaves $2 unset. However, if the pattern is changed to /^(aa(b(b))?)+$/ then $2 (and $3) get set. In Perl 5.004 $2 is set in both cases, and that is also TRUE of PCRE. If in the future Perl changes to a consistent state that is different, PCRE may change to follow.
Another as yet unresolved discrepancy is that in Perl 5.005_02 the pattern /^(a)?(?(1)a|b)+$/ matches the string "a", whereas in PCRE it does not. However, in both Perl and PCRE /^(a)?a/ matched against "a" leaves $1 unset.
PCRE provides some extensions to the Perl regular expression facilities:
1. Although lookbehind assertions must match fixed length strings, each alternative branch of a lookbehind assertion can match a different length of string. Perl 5.005 requires them all to have the same length.
2. If PCRE_DOLLAR_ENDONLY is set and PCRE_MULTILINE is not set, the $ meta- character matches only at the very end of the string.
3. If PCRE_EXTRA is set, a backslash followed by a letter with no special meaning is faulted.
4. If PCRE_UNGREEDY is set, the greediness of the repeti- tion quantifiers is inverted, that is, by default they are not greedy, but if followed by a question mark they are.

Regular Expression Details

Introduction

The syntax and semantics of the regular expressions sup- ported by PCRE are described below. Regular expressions are also described in the Perl documentation and in a number of other books, some of which have copious examples. Jeffrey Friedl's "Mastering Regular Expressions", published by O'Reilly (ISBN 1-56592-257-3), covers them in great detail. The description here is intended as reference documentation. A regular expression is a pattern that is matched against a subject string from left to right. Most characters stand for themselves in a pattern, and match the corresponding charac- ters in the subject. As a trivial example, the pattern The quick brown fox matches a portion of a subject string that is identical to itself.

Meta-characters

The power of regular expressions comes from the ability to include alternatives and repetitions in the pat- tern. These are encoded in the pattern by the use of meta- characters, which do not stand for themselves but instead are interpreted in some special way.

There are two different sets of meta-characters: those that are recognized anywhere in the pattern except within square brackets, and those that are recognized in square brackets. Outside square brackets, the meta-characters are as follows:

\: general escape character with several uses
^: assert start of subject (or line, in multiline mode)
$: assert end of subject (or line, in multiline mode)
.: match any character except newline (by default)
[: start character class definition
]: end character class definition
|: start of alternative branch
(: start subpattern
): end subpattern
?: extends the meaning of (, also 0 or 1 quantifier, also quantifier minimizer
*: 0 or more quantifier
+: 1 or more quantifier
{: start min/max quantifier
}: end min/max quantifier

Part of a pattern that is in square brackets is called a "character class". In a character class the only meta- characters are:

\: general escape character
^: negate the class, but only if the first character
-: indicates character range
]: terminates the character class

The following sections describe the use of each of the meta-characters.

backslash

The backslash character has several uses. Firstly, if it is followed by a non-alphanumeric character, it takes away any special meaning that character may have. This use of backslash as an escape character applies both inside and outside character classes.

For example, if you want to match a "*" character, you write "\*" in the pattern. This applies whether or not the follow- ing character would otherwise be interpreted as a meta- character, so it is always safe to precede a non-alphanumeric with "\" to specify that it stands for itself. In particu- lar, if you want to match a backslash, you write "\\".

If a pattern is compiled with the PCRE_EXTENDED option, whi- tespace in the pattern (other than in a character class) and characters between a "#" outside a character class and the next newline character are ignored. An escaping backslash can be used to include a whitespace or "#" character as part of the pattern.

A second use of backslash provides a way of encoding non- printing characters in patterns in a visible manner. There is no restriction on the appearance of non-printing characters, apart from the binary zero that terminates a pattern, but when a pattern is being prepared by text editing, it is usually easier to use one of the following escape sequences than the binary character it represents:

\a: alarm, that is, the BEL character (hex 07)
\cx: "control-x", where x is any character
\e: escape (hex 1B)
\f: formfeed (hex 0C)
\n: newline (hex 0A)
\r: carriage return (hex 0D)
\t: tab (hex 09)
\xhh: character with hex code hh
\ddd: character with octal code ddd, or backreference

The precise effect of "\cx" is as follows: if "x" is a lower case letter, it is converted to upper case. Then bit 6 of the character (hex 40) is inverted. Thus "\cz" becomes hex 1A, but "\c{" becomes hex 3B, while "\c;" becomes hex 7B.

After "\x", up to two hexadecimal digits are read (letters can be in upper or lower case).

After "\0" up to two further octal digits are read. In both cases, if there are fewer than two digits, just those that are present are used. Thus the sequence "\0\x\07" specifies two binary zeros followed by a BEL character. Make sure you supply two digits after the initial zero if the character that follows is itself an octal digit.

The handling of a backslash followed by a digit other than 0 is complicated. Outside a character class, PCRE reads it and any following digits as a decimal number. If the number is less than 10, or if there have been at least that many previous capturing left parentheses in the expression, the entire sequence is taken as a back reference. A description of how this works is given later, following the discussion of parenthesized subpatterns.

Inside a character class, or if the decimal number is greater than 9 and there have not been that many capturing subpatterns, PCRE re-reads up to three octal digits following the backslash, and generates a single byte from the least significant 8 bits of the value. Any subsequent digits stand for themselves. For example:

\040: is another way of writing a space
\40: is the same, provided there are fewer than 40 previous capturing subpatterns
\7: is always a back reference
\11: might be a back reference, or another way of writing a tab
\011: is always a tab
\0113: is a tab followed by the character "3"
\113: is the character with octal code 113 (since there can be no more than 99 back references)
\377: is a byte consisting entirely of 1 bits
\81: is either a back reference, or a binary zero followed by the two characters "8" and "1"

Note that octal values of 100 or greater must not be intro- duced by a leading zero, because no more than three octal digits are ever read.

All the sequences that define a single byte value can be used both inside and outside character classes. In addition, inside a character class, the sequence "\b" is interpreted as the backspace character (hex 08). Outside a character class it has a different meaning (see below).

The third use of backslash is for specifying generic charac- ter types:

\d: any decimal digit
\D: any character that is not a decimal digit
\s: any whitespace character
\S: any character that is not a whitespace character
\w: any "word" character
\W: any "non-word" character

Each pair of escape sequences partitions the complete set of characters into two disjoint sets. Any given character matches one, and only one, of each pair.

A "word" character is any letter or digit or the underscore character, that is, any character which can be part of a Perl "word". The definition of letters and digits is controlled by PCRE's character tables, and may vary if locale-specific matching is taking place (see "Locale support" above). For example, in the "fr" (French) locale, some char- acter codes greater than 128 are used for accented letters, and these are matched by \w.

These character type sequences can appear both inside and outside character classes. They each match one character of the appropriate type. If the current matching point is at the end of the subject string, all of them fail, since there is no character to match.

The fourth use of backslash is for certain simple asser- tions. An assertion specifies a condition that has to be met at a particular point in a match, without consuming any characters from the subject string. The use of subpatterns for more complicated assertions is described below. The backslashed assertions are

\b: word boundary
\B: not a word boundary
\A: start of subject (independent of multiline mode)
\Z: end of subject or newline at end (independent of multiline mode)
\z: end of subject(independent of multiline mode)

These assertions may not appear in character classes (but note that "\b" has a different meaning, namely the backspace character, inside a character class).

A word boundary is a position in the subject string where the current character and the previous character do not both match \w or \W (i.e. one matches \w and the other matches \W), or the start or end of the string if the first or last character matches \w, respectively.

The \A, \Z, and \z assertions differ from the traditional circumflex and dollar (described below) in that they only ever match at the very start and end of the subject string, whatever options are set. They are not affected by the PCRE_NOTBOL or PCRE_NOTEOL options. The difference between \Z and \z is that \Z matches before a newline that is the last character of the string as well as at the end of the string, whereas \z matches only at the end.

Circumflex and dollar

     Outside a character class, in the default matching mode, the
     circumflex  character  is an assertion which is true only if
     the current matching point is at the start  of  the  subject
     string. Inside a character class, circumflex has an entirely
     different meaning (see below).

     Circumflex need not be the first character of the pattern if
     a number of alternatives are involved, but it should be the
     first thing in each alternative in which it appears  if  the
     pattern is ever to match that branch. If all possible alter-
     natives start with a circumflex, that is, if the pattern  is
     constrained to match only at the start of the subject, it is
     said to be an "anchored" pattern. (There are also other con-
     structs that can cause a pattern to be anchored.)

     A dollar character is an assertion which is TRUE only if the
     current  matching point is at the end of the subject string,
     or immediately before a newline character that is  the  last
     character in the string (by default). Dollar need not be the
     last character of the pattern if a  number  of  alternatives
     are  involved,  but it should be the last item in any branch
     in which it appears.  Dollar has no  special  meaning  in  a
     character class.

     The meaning of dollar can be changed so that it matches only
     at   the   very   end   of   the   string,  by  setting  the
     PCRE_DOLLAR_ENDONLY
     option at compile or matching time. This
     does not affect the \Z assertion.

     The meanings of the circumflex  and  dollar  characters  are
     changed  if  the  PCRE_MULTILINE  option is set. When this is
     the case,  they  match  immediately  after  and  immediately
     before an internal "\n" character, respectively, in addition
     to matching at the start and end of the subject string.  For
     example,  the  pattern  /^abc$/  matches  the subject string
     "def\nabc" in multiline  mode,  but  not  otherwise.  Conse-
     quently,  patterns  that  are  anchored  in single line mode
     because all branches start with "^" are not anchored in mul-
     tiline  mode.  The  PCRE_DOLLAR_ENDONLY  option is ignored if
     PCRE_MULTILINE  is set.

     Note that the sequences \A, \Z, and \z can be used to  match
     the  start  and end of the subject in both modes, and if all
     branches of a pattern start with \A is it  always  anchored,
     whether PCRE_MULTILINE  is set or not.

FULL STOP

     Outside a character class, a dot in the pattern matches  any
     one  character  in  the  subject,  including  a non-printing
     character, but not (by default) newline.  If the PCRE_DOTALL
     option  is  set,  then dots match newlines as well. The han-
     dling of dot is entirely independent of the handling of cir-
     cumflex  and  dollar,  the only relationship being that they
     both involve newline characters.  Dot has no special meaning
     in a character class.

Square brackets

     An opening square bracket introduces a character class, ter-
     minated  by  a  closing  square  bracket.  A  closing square
     bracket on its own is  not  special.  If  a  closing  square
     bracket  is  required as a member of the class, it should be
     the first data character in the class (after an initial cir-
     cumflex, if present) or escaped with a backslash.

     A character class matches a single character in the subject;
     the  character  must  be in the set of characters defined by
     the class, unless the first character in the class is a cir-
     cumflex,  in which case the subject character must not be in
     the set defined by the class. If a  circumflex  is  actually
     required  as  a  member  of  the class, ensure it is not the
     first character, or escape it with a backslash.

     For example, the character class [aeiou] matches  any  lower
     case vowel, while [^aeiou] matches any character that is not
     a lower case vowel. Note that a circumflex is  just  a  con-
     venient  notation for specifying the characters which are in
     the class by enumerating those that are not. It  is  not  an
     assertion:  it  still  consumes a character from the subject
     string, and fails if the current pointer is at  the  end  of
     the string.

     When caseless matching  is  set,  any  letters  in  a  class
     represent  both their upper case and lower case versions, so
     for example, a caseless [aeiou] matches "A" as well as  "a",
     and  a caseless [^aeiou] does not match "A", whereas a case-
     ful version would.

     The newline character is never treated in any special way in
     character  classes,  whatever the setting of the PCRE_DOTALL
     or PCRE_MULTILINE  options is. A  class  such  as  [^a]  will
     always match a newline.

     The minus (hyphen) character can be used to specify a  range
     of  characters  in  a  character  class.  For example, [d-m]
     matches any letter between d and m, inclusive.  If  a  minus
     character  is required in a class, it must be escaped with a
     backslash or appear in a position where it cannot be  inter-
     preted as indicating a range, typically as the first or last
     character in the class.

     It is not possible to have the literal character "]" as  the
     end  character  of  a  range.  A  pattern such as [W-]46] is
     interpreted as a class of two characters ("W" and "-")  fol-
     lowed by a literal string "46]", so it would match "W46]" or
     "-46]". However, if the "]" is escaped with a  backslash  it
     is  interpreted  as  the end of range, so [W-\]46] is inter-
     preted as a single class containing a range followed by  two
     separate characters. The octal or hexadecimal representation
     of "]" can also be used to end a range.

     Ranges operate in ASCII collating sequence. They can also be
     used  for  characters  specified  numerically,  for  example
     [\000-\037]. If a range that includes letters is  used  when
     caseless  matching  is set, it matches the letters in either
     case. For example, [W-c] is equivalent  to  [][\^_`wxyzabc],
     matched  caselessly,  and  if  character tables for the "fr"
     locale are in use, [\xc8-\xcb] matches accented E characters
     in both cases.

     The character types \d, \D, \s, \S,  \w,  and  \W  may  also
     appear  in  a  character  class, and add the characters that
     they match to the class. For example, [\dABCDEF] matches any
     hexadecimal  digit.  A  circumflex  can conveniently be used
     with the upper case character types to specify a  more  res-
     tricted set of characters than the matching lower case type.
     For example, the class [^\W_] matches any letter  or  digit,
     but not underscore.

     All non-alphanumeric characters other than \,  -,  ^  (at  the
     start)  and  the  terminating ] are non-special in character
     classes, but it does no harm if they are escaped.

Vertical bar

     Vertical bar characters are  used  to  separate  alternative
     patterns. For example, the pattern

       gilbert|sullivan

     matches either "gilbert" or "sullivan". Any number of alternatives
     may  appear,  and an empty alternative is permitted
     (matching the empty string).   The  matching  process  tries
     each  alternative in turn, from left to right, and the first
     one that succeeds is used. If the alternatives are within  a
     subpattern  (defined  below),  "succeeds" means matching the
     rest of the main pattern as well as the alternative  in  the
     subpattern.

Internal option setting

     The settings of PCRE_CASELESS ,
     PCRE_MULTILINE ,
     PCRE_DOTALL ,
     and  PCRE_EXTENDED  can be changed from within the pattern by
     a sequence of Perl option letters enclosed between "(?"  and
     ")". The option letters are

       i  for PCRE_CASELESS
       m  for PCRE_MULTILINE
       s  for PCRE_DOTALL
       x  for PCRE_EXTENDED

     For example, (?im) sets caseless, multiline matching. It  is
     also possible to unset these options by preceding the letter
     with a hyphen, and a combined setting and unsetting such  as
     (?im-sx),  which sets PCRE_CASELESS  and PCRE_MULTILINE  while
     unsetting PCRE_DOTALL  and PCRE_EXTENDED , is also  permitted.
     If  a  letter  appears both before and after the hyphen, the
     option is unset.

     The scope of these option changes depends on  where  in  the
     pattern  the  setting  occurs. For settings that are outside
     any subpattern (defined below), the effect is the same as if
     the  options were set or unset at the start of matching. The
     following patterns all behave in exactly the same way:

       (?i)abc
       a(?i)bc
       ab(?i)c
       abc(?i)

     which in turn is the same as compiling the pattern abc  with
     PCRE_CASELESS set.
     In  other words, such "top level" settings apply to the whole
     pattern  (unless  there  are  other changes  inside subpatterns).
     If there is more than one setting of the same option at top level,
     the rightmost  setting is used.

     If an option change occurs inside a subpattern,  the  effect
     is  different.  This is a change of behaviour in Perl 5.005.
     An option change inside a subpattern affects only that  part
     of the subpattern that follows it, so

       (a(?i)b)c

     matches  abc  and  aBc  and  no  other   strings   (assuming
     PCRE_CASELESS   is  not used).  By this means, options can be
     made to have different settings in different  parts  of  the
     pattern.  Any  changes  made  in one alternative do carry on
     into subsequent branches within  the  same  subpattern.  For
     example,

       (a(?i)b|c)

     matches "ab", "aB", "c", and "C", even though when  matching
     "C" the first branch is abandoned before the option setting.
     This is because the effects of  option  settings  happen  at
     compile  time. There would be some very weird behaviour otherwise.

     The PCRE-specific options PCRE_UNGREEDY  and
     PCRE_EXTRA   can
     be changed in the same way as the Perl-compatible options by
     using the characters U and X  respectively.  The  (?X)  flag
     setting  is  special in that it must always occur earlier in
     the pattern than any of the additional features it turns on,
     even when it is at top level. It is best put at the start.

subpatterns

     Subpatterns are delimited by parentheses  (round  brackets),
     which can be nested.  Marking part of a pattern as a subpattern
     does two things:

     1. It localizes a set of alternatives. For example, the pat-
     tern

       cat(aract|erpillar|)

     matches one of the words "cat",  "cataract",  or  "caterpillar".
     Without  the  parentheses, it would match "cataract",
     "erpillar" or the empty string.

     2. It sets up the subpattern as a capturing  subpattern  (as
     defined  above).   When the whole pattern matches, that portion
     of the subject string that matched  the  subpattern  is
     passed  back  to  the  caller  via  the  ovector
     argument of
     pcre_exec(). Opening parentheses are counted
     from  left  to right (starting from 1) to obtain the numbers of the
     capturing subpatterns.

     For example, if the string "the red king" is matched against
     the pattern

       the ((red|white) (king|queen))

     the captured substrings are "red king", "red",  and  "king",
     and are numbered 1, 2, and 3.

     The fact that plain parentheses fulfil two functions is  not
     always  helpful.  There are often times when a grouping subpattern
     is required without a capturing requirement.  If  an
     opening parenthesis is followed by "?:", the subpattern does
     not do any capturing, and is not counted when computing  the
     number of any subsequent capturing subpatterns. For example,
     if the string "the  white  queen"  is  matched  against  the
     pattern

       the ((?:red|white) (king|queen))

     the captured substrings are "white queen" and  "queen",  and
     are  numbered  1  and 2. The maximum number of captured substrings
     is 99, and the maximum number  of  all  subpatterns,
     both capturing and non-capturing, is 200.

     As a  convenient  shorthand,  if  any  option  settings  are
     required  at  the  start  of a non-capturing subpattern, the
     option letters may appear between the "?" and the ":".  Thus
     the two patterns

       (?i:saturday|sunday)
       (?:(?i)saturday|sunday)

     match exactly the same set of strings.  Because  alternative
     branches  are  tried from left to right, and options are not
     reset until the end of the subpattern is reached, an  option
     setting  in  one  branch does affect subsequent branches, so
     the above patterns match "SUNDAY" as well as "Saturday".

Repetition

     Repetition is specified by quantifiers, which can follow any
     of the following items:

       a single character, possibly escaped
       the . metacharacter
       a character class
       a back reference (see next section)
       a parenthesized subpattern (unless it is  an  assertion  -
     see below)

     The general repetition quantifier specifies  a  minimum  and
     maximum  number  of  permitted  matches,  by  giving the two
     numbers in curly brackets (braces), separated  by  a  comma.
     The  numbers  must be less than 65536, and the first must be
     less than or equal to the second. For example:

       z{2,4}

     matches "zz", "zzz", or "zzzz". A closing brace on  its  own
     is not a special character. If the second number is omitted,
     but the comma is present, there is no upper  limit;  if  the
     second number and the comma are both omitted, the quantifier
     specifies an exact number of required matches. Thus

       [aeiou]{3,}

     matches at least 3 successive vowels,  but  may  match  many
     more, while

       \d{8}

     matches exactly 8 digits.  An  opening  curly  bracket  that
     appears  in a position where a quantifier is not allowed, or
     one that does not match the syntax of a quantifier, is taken
     as  a literal character. For example, {,6} is not a quantifier,
     but a literal string of four characters.

     The quantifier {0} is permitted, causing the  expression  to
     behave  as  if the previous item and the quantifier were not
     present.

     For convenience (and  historical  compatibility)  the  three
     most common quantifiers have single-character abbreviations:

       *    is equivalent to {0,}
       +    is equivalent to {1,}
       ?    is equivalent to {0,1}

     It is possible to construct infinite loops  by  following  a
     subpattern  that  can  match no characters with a quantifier
     that has no upper limit, for example:

       (a?)*

     Earlier versions of Perl and PCRE used to give an  error  at
     compile  time  for such patterns. However, because there are
     cases where this  can  be  useful,  such  patterns  are  now
     accepted,  but  if  any repetition of the subpattern does in
     fact match no characters, the loop is forcibly broken.

     By default, the quantifiers  are  "greedy",  that  is,  they
     match  as much as possible (up to the maximum number of permitted
     times), without causing the rest of  the  pattern  to
     fail. The classic example of where this gives problems is in
     trying to match comments in C programs. These appear between
     the  sequences /* and */ and within the sequence, individual
     * and / characters may appear. An attempt to  match  C  comments
     by applying the pattern

       /\*.*\*/

     to the string

       /* first command */  not comment  /* second comment */

     fails, because it matches  the  entire  string  due  to  the
     greediness of the .*  item.

     However, if a quantifier is followed  by  a  question  mark,
     then it ceases to be greedy, and instead matches the minimum
     number of times possible, so the pattern

       /\*.*?\*/

     does the right thing with the C comments. The meaning of the
     various  quantifiers is not otherwise changed, just the preferred
     number of matches.  Do not confuse this use of  ques-
     tion  mark  with  its  use as a quantifier in its own right.
     Because it has two uses, it can sometimes appear doubled, as
     in

       \d??\d

     which matches one digit by preference, but can match two  if
     that is the only way the rest of the pattern matches.

     If the PCRE_UNGREEDY  option is set (an option which  is  not
     available  in  Perl)  then the quantifiers are not greedy by
     default, but individual ones can be made greedy by following
     them  with  a  question mark. In other words, it inverts the
     default behaviour.

     When a parenthesized subpattern is quantified with a minimum
     repeat  count  that is greater than 1 or with a limited maximum,
     more store is required for the  compiled  pattern,  in
     proportion to the size of the minimum or maximum.

     If a pattern starts with .* or  .{0,}  and  the  PCRE_DOTALL
     option (equivalent to Perl's /s) is set, thus allowing the .
     to match newlines, then the pattern is implicitly  anchored,
     because whatever follows will be tried against every character
     position in the subject string, so there is no point  in
     retrying  the overall match at any position after the first.
     PCRE treats such a pattern as though it were preceded by \A.
     In  cases where it is known that the subject string contains
     no newlines, it is worth setting PCRE_DOTALL  when  the  pattern begins with .* in order to
     obtain this optimization, or
     alternatively using ^ to indicate anchoring explicitly.

     When a capturing subpattern is repeated, the value  captured
     is the substring that matched the final iteration. For example, after

       (tweedle[dume]{3}\s*)+

     has matched "tweedledum tweedledee" the value  of  the  captured
     substring  is  "tweedledee".  However,  if  there are
     nested capturing  subpatterns,  the  corresponding  captured
     values  may  have been set in previous iterations. For example,
     after

       /(a|(b))+/

     matches "aba" the value of the second captured substring  is
     "b".

BACK REFERENCES

     Outside a character class, a backslash followed by  a  digit
     greater  than  0  (and  possibly  further  digits) is a back
     reference to a capturing subpattern  earlier  (i.e.  to  its
     left)  in  the  pattern,  provided there have been that many
     previous capturing left parentheses.

     However, if the decimal number following  the  backslash  is
     less  than  10,  it is always taken as a back reference, and
     causes an error only if there are not  that  many  capturing
     left  parentheses in the entire pattern. In other words, the
     parentheses that are referenced need not be to the  left  of
     the  reference  for  numbers  less  than 10. See the section
     entitled "Backslash" above for further details of  the  handling
     of digits following a backslash.

     A back reference matches whatever actually matched the  capturing
     subpattern in the current subject string, rather than
     anything matching the subpattern itself. So the pattern

       (sens|respons)e and \1ibility

     matches "sense and sensibility" and "response and  responsibility",
     but  not  "sense  and  responsibility". If caseful
     matching is in force at the time of the back reference, then
     the case of letters is relevant. For example,

       ((?i)rah)\s+\1

     matches "rah rah" and "RAH RAH", but  not  "RAH  rah",  even
     though  the  original  capturing subpattern is matched caselessly.

     There may be more than one back reference to the  same  subpattern.
     If  a  subpattern  has not actually been used in a
     particular match, then any  back  references  to  it  always
     fail. For example, the pattern

       (a|(bc))\2

     always fails if it starts to match  "a"  rather  than  "bc".
     Because  there  may  be up to 99 back references, all digits
     following the backslash are taken as  part  of  a  potential
     back reference number. If the pattern continues with a digit
     character, then some delimiter must be used to terminate the
     back reference. If the PCRE_EXTENDED  option is set, this can
     be whitespace.  Otherwise an empty comment can be used.

     A back reference that occurs inside the parentheses to which
     it  refers  fails when the subpattern is first used, so, for
     example, (a\1) never matches.  However, such references  can
     be useful inside repeated subpatterns. For example, the pattern

       (a|b\1)+

     matches any number of "a"s and also "aba", "ababaa" etc.  At
     each iteration of the subpattern, the back reference matches
     the character string corresponding to  the  previous  iteration.
     In order for this to work, the pattern must be such
     that the first iteration does not need  to  match  the  back
     reference.  This  can  be  done using alternation, as in the
     example above, or by a quantifier with a minimum of zero.

Assertions

     An assertion is  a  test  on  the  characters  following  or
     preceding  the current matching point that does not actually
     consume any characters. The simple assertions coded  as  \b,
     \B,  \A,  \Z,  \z, ^ and $ are described above. More complicated
     assertions are coded as  subpatterns.  There  are  two
     kinds:  those that look ahead of the current position in the
     subject string, and those that look behind it.

     An assertion subpattern is matched in the normal way, except
     that  it  does not cause the current matching position to be
     changed. Lookahead assertions start with  (?=  for  positive
     assertions and (?! for negative assertions. For example,

       \w+(?=;)

     matches a word followed by a semicolon, but does not include
     the semicolon in the match, and

       foo(?!bar)

     matches any occurrence of "foo"  that  is  not  followed  by
     "bar". Note that the apparently similar pattern

       (?!foo)bar

     does not find an occurrence of "bar"  that  is  preceded  by
     something other than "foo"; it finds any occurrence of "bar"
     whatsoever, because the assertion  (?!foo)  is  always  TRUE
     when  the  next  three  characters  are  "bar". A lookbehind
     assertion is needed to achieve this effect.

     Lookbehind assertions start with (?<=  for  positive  assertions
     and (?<! for negative assertions. For example,

       (?<!foo)bar

     does find an occurrence of "bar" that  is  not  preceded  by
     "foo". The contents of a lookbehind assertion are restricted
     such that all the strings  it  matches  must  have  a  fixed
     length.  However, if there are several alternatives, they do
     not all have to have the same fixed length. Thus

       (?<=bullock|donkey)

     is permitted, but

       (?<!dogs?|cats?)

     causes an error at compile time. Branches  that  match  different
     length strings are permitted only at the top level of
     a lookbehind assertion. This is an extension  compared  with
     Perl  5.005,  which  requires all branches to match the same
     length of string. An assertion such as

       (?<=ab(c|de))

     is not permitted, because its single  top-level  branch  can
     match two different lengths, but it is acceptable if rewritten
     to use two top-level branches:

       (?<=abc|abde)

     The implementation of lookbehind  assertions  is,  for  each
     alternative,  to  temporarily move the current position back
     by the fixed width and then  try  to  match.  If  there  are
     insufficient  characters  before  the  current position, the
     match is deemed to fail.  Lookbehinds  in  conjunction  with
     once-only  subpatterns can be particularly useful for matching
     at the ends of strings; an example is given at  the  end
     of the section on once-only subpatterns.

     Several assertions (of any sort) may  occur  in  succession.
     For example,

       (?<=\d{3})(?<!999)foo

     matches "foo" preceded by three digits that are  not  "999".
     Notice  that each of the assertions is applied independently
     at the same point in the subject string. First  there  is  a
     check  that  the  previous  three characters are all digits,
     then there is a check that the same three characters are not
     "999".   This  pattern  does not match "foo" preceded by six
     characters, the first of which are digits and the last three
     of  which  are  not  "999".  For  example,  it doesn't match
     "123abcfoo". A pattern to do that is

       (?<=\d{3}...)(?<!999)foo

     This time the first assertion looks  at  the  preceding  six
     characters,  checking  that  the first three are digits, and
     then the second assertion checks that  the  preceding  three
     characters are not "999".

     Assertions can be nested in any combination. For example,

       (?<=(?<!foo)bar)baz

     matches an occurrence of "baz" that  is  preceded  by  "bar"
     which in turn is not preceded by "foo", while

       (?<=\d{3}(?!999)...)foo

     is another pattern which matches  "foo"  preceded  by  three
     digits and any three characters that are not "999".

     Assertion subpatterns are not capturing subpatterns, and may
     not  be  repeated,  because  it makes no sense to assert the
     same thing several times. If any kind of assertion  contains
     capturing  subpatterns  within it, these are counted for the
     purposes of numbering the capturing subpatterns in the whole
     pattern.   However,  substring capturing is carried out only
     for positive assertions, because it does not make sense  for
     negative assertions.

     Assertions count towards the maximum  of  200  parenthesized
     subpatterns.

Once-only subpatterns

     With both maximizing and minimizing repetition,  failure  of
     what  follows  normally  causes  the repeated item to be re-
     evaluated to see if a different number of repeats allows the
     rest  of  the  pattern  to  match. Sometimes it is useful to
     prevent this, either to change the nature of the  match,  or
     to  cause  it fail earlier than it otherwise might, when the
     author of the pattern knows there is no  point  in  carrying
     on.

     Consider, for example, the pattern \d+foo  when  applied  to
     the subject line

       123456bar

     After matching all 6 digits and then failing to match "foo",
     the normal action of the matcher is to try again with only 5
     digits matching the \d+ item, and then with 4,  and  so  on,
     before ultimately failing. Once-only subpatterns provide the
     means for specifying that once a portion of the pattern  has
     matched,  it  is  not to be re-evaluated in this way, so the
     matcher would give up immediately on failing to match  "foo"
     the  first  time.  The  notation  is another kind of special
     parenthesis, starting with (?> as in this example:

       (?>\d+)bar

     This kind of parenthesis "locks up" the  part of the pattern
     it  contains once it has matched, and a failure further into
     the pattern is prevented from backtracking  into  it.  Back-
     tracking  past  it to previous items, however, works as normal.

     An alternative description is that a subpattern of this type
     matches  the  string  of  characters that an identical standalone
     pattern would match, if anchored at the current point
     in the subject string.

     Once-only subpatterns are not capturing subpatterns.  Simple
     cases  such as the above example can be thought of as a maximizing
     repeat that must  swallow  everything  it  can.  So,
     while both \d+ and \d+? are prepared to adjust the number of
     digits they match in order to make the rest of  the  pattern
     match, (?>\d+) can only match an entire sequence of digits.

     This construction can of course contain arbitrarily  complicated
     subpatterns, and it can be nested.

     Once-only subpatterns can be used in conjunction with  look-
     behind  assertions  to specify efficient matching at the end
     of the subject string. Consider a simple pattern such as

       abcd$

     when applied to a long string which does not match.  Because
     matching  proceeds  from  left  to right, PCRE will look for
     each "a" in the subject and then see if what follows matches
     the rest of the pattern. If the pattern is specified as

       ^.*abcd$

     then the initial .* matches the entire string at first,  but
     when  this  fails  (because  there  is no following "a"), it
     backtracks to match all but the last character, then all but
     the  last  two  characters, and so on. Once again the search
     for "a" covers the entire string, from right to left, so  we
     are no better off. However, if the pattern is written as

       ^(?>.*)(?<=abcd)

     then there can be no backtracking for the .*  item;  it  can
     match  only  the  entire  string.  The subsequent lookbehind
     assertion does a single test on the last four characters. If
     it  fails,  the  match  fails immediately. For long strings,
     this approach makes a significant difference to the processing time.

     When a pattern contains an unlimited repeat inside a subpattern
     that can itself be repeated an unlimited number of
     times, the use of a once-only subpattern is the only way  to
     avoid  some  failing matches taking a very long time indeed.
     The pattern

       (\D+|<\d+>)*[!?]

     matches an unlimited number of substrings that  either  consist
     of  non-digits,  or digits enclosed in <>, followed by
     either ! or ?. When it matches, it runs quickly. However, if
     it is applied to

       aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

     it takes a long  time  before  reporting  failure.  This  is
     because the string can be divided between the two repeats in
     a large number of ways, and all have to be tried. (The example
     used  [!?]  rather  than a single character at the end,
     because both PCRE and Perl have an optimization that  allows
     for  fast  failure  when  a  single  character is used. They
     remember the last single character that is  required  for  a
     match,  and  fail early if it is not present in the string.)
     If the pattern is changed to

       ((?>\D+)|<\d+>)*[!?]

     sequences of non-digits cannot be broken, and  failure  happens quickly.

Conditional subpatterns

     It is possible to cause the matching process to obey a  subpattern
     conditionally  or to choose between two alternative
     subpatterns, depending on the result  of  an  assertion,  or
     whether  a previous capturing subpattern matched or not. The
     two possible forms of conditional subpattern are

       (?(condition)yes-pattern)
       (?(condition)yes-pattern|no-pattern)

     If the condition is satisfied, the yes-pattern is used; otherwise
     the  no-pattern  (if  present) is used. If there are
     more than two alternatives in the subpattern, a compile-time
     error occurs.

     There are two kinds of condition. If the  text  between  the
     parentheses  consists  of  a  sequence  of  digits, then the
     condition is satisfied if the capturing subpattern  of  that
     number  has  previously matched. Consider the following pattern,
     which contains non-significant white space to make  it
     more  readable  (assume  the  PCRE_EXTENDED   option)  and to
     divide it into three parts for ease of discussion:

       ( $ )?    [^()]+    (?(1) $ )

     The first part matches an optional opening parenthesis,  and
     if  that character is present, sets it as the first captured
     substring. The second part matches one  or  more  characters
     that  are  not  parentheses. The third part is a conditional
     subpattern that tests whether the first set  of  parentheses
     matched  or  not.  If  they did, that is, if subject started
     with an opening parenthesis, the condition is TRUE,  and  so
     the  yes-pattern  is  executed  and a closing parenthesis is
     required. Otherwise, since no-pattern is  not  present,  the
     subpattern  matches  nothing.  In  other words, this pattern
     matches a sequence of non-parentheses,  optionally  enclosed
     in parentheses.

     If the condition is not a sequence of digits, it must be  an
     assertion.  This  may be a positive or negative lookahead or
     lookbehind assertion. Consider this pattern, again  containing
     non-significant  white space, and with the two alternatives on
     the second line:

       (?(?=[^a-z]*[a-z])
       \d{2}-[a-z]{3}-\d{2}  |  \d{2}-\d{2}-\d{2} )

     The condition is a positive lookahead assertion that matches
     an optional sequence of non-letters followed by a letter. In
     other words, it tests for  the  presence  of  at  least  one
     letter  in the subject. If a letter is found, the subject is
     matched against  the  first  alternative;  otherwise  it  is
     matched  against the second. This pattern matches strings in
     one of the two forms dd-aaa-dd or dd-dd-dd,  where  aaa  are
     letters and dd are digits.

Comments

     The  sequence  (?#  marks  the  start  of  a  comment  which
     continues   up  to  the  next  closing  parenthesis.  Nested
     parentheses are not permitted. The characters that make up a
     comment play no part in the pattern matching at all.

     If the PCRE_EXTENDED  option is set, an unescaped # character
     outside  a character class introduces a comment that contin-
     ues up to the next newline character in the pattern.

Recursive patterns

     Consider the problem of matching a  string  in  parentheses,
     allowing  for  unlimited nested parentheses. Without the use
     of recursion, the best that can be done is to use a  pattern
     that  matches  up  to some fixed depth of nesting. It is not
     possible to handle an arbitrary nesting depth. Perl 5.6  has
     provided   an  experimental  facility  that  allows  regular
     expressions to recurse (amongst other things).  The  special
     item (?R) is  provided for  the specific  case of recursion.
     This PCRE  pattern  solves the  parentheses  problem (assume
     the PCRE_EXTENDED
     option is set so that white space is
     ignored):

       $ ( (?>[^()]+) | (?R) )* $

     First it matches an opening parenthesis. Then it matches any
     number  of substrings which can either be a sequence of non-
     parentheses, or a recursive  match  of  the  pattern  itself
     (i.e. a correctly parenthesized substring). Finally there is
     a closing parenthesis.

     This particular example pattern  contains  nested  unlimited
     repeats, and so the use of a once-only subpattern for matching
     strings of non-parentheses is  important  when  applying
     the  pattern to strings that do not match. For example, when
     it is applied to

       (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa()

     it yields "no match" quickly. However, if a  once-only  subpattern
     is  not  used,  the match runs for a very long time
     indeed because there are so many different ways the + and  *
     repeats  can carve up the subject, and all have to be tested
     before failure can be reported.

     The values set for any capturing subpatterns are those  from
     the outermost level of the recursion at which the subpattern
     value is set. If the pattern above is matched against

       (ab(cd)ef)

     the value for the capturing parentheses is  "ef",  which  is
     the  last  value  taken  on  at the top level. If additional
     parentheses are added, giving

       $ ( ( (?>[^()]+) | (?R) )* ) $
          ^                        ^
          ^                        ^ then the string they capture
     is "ab(cd)ef", the contents of the top level parentheses. If
     there are more than 15 capturing parentheses in  a  pattern,
     PCRE  has  to  obtain  extra  memory  to store data during a
     recursion, which it does by using  pcre_malloc,  freeing  it
     via  pcre_free  afterwards. If no memory can be obtained, it
     saves data for the first 15 capturing parentheses  only,  as
     there is no way to give an out-of-memory error from within a
     recursion.

Performances

     Certain items that may appear in patterns are more efficient
     than  others.  It is more efficient to use a character class
     like [aeiou] than a set of alternatives such as (a|e|i|o|u).
     In  general,  the  simplest  construction  that provides the
     required behaviour is usually the  most  efficient.  Jeffrey
     Friedl's  book contains a lot of discussion about optimizing
     regular expressions for efficient performance.

     When a pattern begins with .* and the PCRE_DOTALL  option  is
     set,  the  pattern  is implicitly anchored by PCRE, since it
     can match only at the start of a subject string. However, if
     PCRE_DOTALL   is not set, PCRE cannot make this optimization,
     because the . metacharacter does not then match  a  newline,
     and if the subject string contains newlines, the pattern may
     match from the character immediately following one  of  them
     instead of from the very start. For example, the pattern

       (.*) second

     matches the subject "first\nand second" (where \n stands for
     a newline character) with the first captured substring being
     "and". In order to do this, PCRE  has  to  retry  the  match
     starting after every newline in the subject.

     If you are using such a pattern with subject strings that do
     not  contain  newlines,  the best performance is obtained by
     setting PCRE_DOTALL , or starting the  pattern  with  ^.*  to
     indicate  explicit anchoring. That saves PCRE from having to
     scan along the subject looking for a newline to restart at.

     Beware of patterns that contain nested  indefinite  repeats.
     These  can  take a long time to run when applied to a string
     that does not match. Consider the pattern fragment

       (a+)*

     This can match "aaaa" in 33 different ways, and this  number
     increases  very  rapidly  as  the string gets longer. (The *
     repeat can match 0, 1, 2, 3, or 4 times,  and  for  each  of
     those  cases other than 0, the + repeats can match different
     numbers of times.) When the remainder of the pattern is such
     that  the entire match is going to fail, PCRE has in principle
     to try every possible variation, and this  can  take  an
     extremely long time.

     An optimization catches some of the more simple  cases  such
     as

       (a+)*b

     where a literal character follows. Before embarking  on  the
     standard matching procedure, PCRE checks that there is a "b"
     later in the subject string, and if there is not,  it  fails
     the  match  immediately. However, when there is no following
     literal this optimization cannot be used. You  can  see  the
     difference by comparing the behaviour of

       (a+)*\d

     with the pattern above. The former gives  a  failure  almost
     instantly  when  applied  to a whole line of "a" characters,
     whereas the latter takes an appreciable  time  with  strings
     longer than about 20 characters.

preg_grep

(PHP 4 )

preg_grep -- Return array entries that match the pattern

Description

array preg_grep ( string pattern, array input)

preg_grep() returns the array consisting of the elements of the input array that match the given pattern.

Since PHP 4.0.4, the results returned by preg_grep() are indexed using the keys from the input array. If this behavior is undesirable, use array_values() on the array returned by preg_grep() to reindex the values.

Example 1. preg_grep() example
// return all array elements // containing floating point numbers $fl_array = preg_grep ("/^(\d+)?\.\d+$/", $array);

preg_match_all

(PHP 3>= 3.0.9, PHP 4 )

preg_match_all -- Perform a global regular expression match

Description

int preg_match_all ( string pattern, string subject, array matches [, int flags])

Searches subject for all matches to the regular expression given in pattern and puts them in matches in the order specified by order.

After the first match is found, the subsequent searches are continued on from end of the last match.

flags can be a combination of the following flags (note that it doesn't make sense to use PREG_PATTERN_ORDER together with PREG_SET_ORDER):

PREG_PATTERN_ORDER

Orders results so that $matches[0] is an array of full pattern matches, $matches[1] is an array of strings matched by the first parenthesized subpattern, and so on.

preg_match_all ("|<[^>]+>(.*)</[^>]+>|U", 
    "<b>example: </b><div align=left>this is a test</div>", 
    $out, PREG_PATTERN_ORDER);
print $out[0][0].", ".$out[0][1]."\n";
print $out[1][0].", ".$out[1][1]."\n";

This example will produce:
<b>example: </b>, <div align=left>this is a test</div> example: , this is a test
So, $out[0] contains array of strings that matched full pattern, and $out[1] contains array of strings enclosed by tags.

PREG_SET_ORDER

Orders results so that $matches[0] is an array of first set of matches, $matches[1] is an array of second set of matches, and so on.

preg_match_all ("|<[^>]+>(.*)</[^>]+>|U", 
    "<b>example: </b><div align=left>this is a test</div>", 
    $out, PREG_SET_ORDER);
print $out[0][0].", ".$out[0][1]."\n";
print $out[1][0].", ".$out[1][1]."\n";

This example will produce:

<b>example: </b>, example: 
<div align=left>this is a test</div>, this is a test

In this case, $matches[0] is the first set of matches, and $matches[0][0] has text matched by full pattern, $matches[0][1] has text matched by first subpattern and so on. Similarly, $matches[1] is the second set of matches, etc.

PREG_OFFSET_CAPTURE

If this flag is set, for every occuring match the appendant string offset will also be returned. Note that this changes the return value in an array where every element is an array consisting of the matched string at offset 0 and it's string offset into subject at offset 1. This flag is available since PHP 4.3.0 .

If no order flag is given, PREG_PATTERN_ORDER is assumed.

Returns the number of full pattern matches (which might be zero), or FALSE if an error occurred.

Example 1. Getting all phone numbers out of some text.
preg_match_all ("/$? (\d{3})? $? (?(1) [\-\s] ) \d{3}-\d{4}/x", "Call 555-1212 or 1-800-555-1212", $phones);

Example 2. Find matching HTML tags (greedy)
// The \\2 is an example of backreferencing. This tells pcre that // it must match the second set of parentheses in the regular expression // itself, which would be the ([\w]+) in this case. The extra backslash is // required because the string is in double quotes. $html = "<b>bold text</b><a href=howdy.html>click me</a>"; preg_match_all ("/(<([\w]+)[^>]*>)(.*)(<\/\\2>)/", $html, $matches); for ($i=0; $i< count($matches[0]); $i++) { echo "matched: ".$matches[0][$i]."\n"; echo "part 1: ".$matches[1][$i]."\n"; echo "part 2: ".$matches[3][$i]."\n"; echo "part 3: ".$matches[4][$i]."\n\n"; }
This example will produce:
matched: <b>bold text</b> part 1: <b> part 2: bold text part 3: </b> matched: <a href=howdy.html>click me</a> part 1: <a href=howdy.html> part 2: click me part 3: </a>

preg_match

(PHP 3>= 3.0.9, PHP 4 )

preg_match -- Perform a regular expression match

Description

int preg_match ( string pattern, string subject [, array matches [, int flags]])

Searches subject for a match to the regular expression given in pattern.

If matches is provided, then it is filled with the results of search. $matches[0] will contain the text that matched the full pattern, $matches[1] will have the text that matched the first captured parenthesized subpattern, and so on.

flags can be the following flag:

PREG_OFFSET_CAPTURE: If this flag is set, for every occuring match the appendant string offset will also be returned. Note that this changes the return value in an array where every element is an array consisting of the matched string at offset 0 and it's string offset into subject at offset 1. This flag is available since PHP 4.3.0 .

The flags parameter is available since PHP 4.3.0 .

If pattern and replacement are arrays, then preg_replace() takes a value from each array and uses them to do search and replace on subject. If replacement has fewer values than pattern, then empty string is used for the rest of replacement values. If pattern is an array and replacement is a string, then this replacement string is used for every value of pattern. The converse would not make sense, though.

/e modifier makes preg_replace() treat the replacement parameter as PHP code after the appropriate references substitution is done. Tip: make sure that replacement constitutes a valid PHP code string, otherwise PHP will complain about a parse error at the line containing preg_replace().

Example 1. Replacing several values
$patterns = array ("/(19|20)(\d{2})-(\d{1,2})-(\d{1,2})/", "/^\s*{(\w+)}\s*=/"); $replace = array ("\\3/\\4/\\1\\2", "$\\1 ="); print preg_replace ($patterns, $replace, "{startDate} = 1999-5-27");
This example will produce:
$startDate = 5/27/1999

Example 2. Using /e modifier
preg_replace ("/(<\/?)(\w+)([^>]*>)/e", "'\\1'.strtoupper('\\2').'\\3'", $html_body);
This would capitalize all HTML tags in the input text.

Example 3. Convert HTML to text
// $document should contain an HTML document. // This will remove HTML tags, javascript sections // and white space. It will also convert some // common HTML entities to their text equivalent. $search = array ("'<script[^>]*?>.*?</script>'si", // Strip out javascript "'<[\/\!]*?[^<>]*?>'si", // Strip out html tags "'([\r\n])[\s]+'", // Strip out white space "'&(quot|#34);'i", // Replace html entities "'&(amp|#38);'i", "'&(lt|#60);'i", "'&(gt|#62);'i", "'&(nbsp|#160);'i", "'&(iexcl|#161);'i", "'&(cent|#162);'i", "'&(pound|#163);'i", "'&(copy|#169);'i", "'&#(\d+);'e"); // evaluate as php $replace = array ("", "", "\\1", "\"", "&", "<", ">", " ", chr(161), chr(162), chr(163), chr(169), "chr(\\1)"); $text = preg_replace ($search, $replace, $document);

Note: Parameter limit was added after PHP 4.0.1pl2.

preg_split

(PHP 3>= 3.0.9, PHP 4 )

preg_split -- Split string by a regular expression

Description

array preg_split ( string pattern, string subject [, int limit [, int flags]])

Note: Parameter flags was added in PHP 4 Beta 3.

Returns an array containing substrings of subject split along boundaries matched by pattern.

If limit is specified, then only substrings up to limit are returned, and if limit is -1, it actually means "no limit", which is useful for specifying the flags.

flags can be any combination of the following flags (combined with bitwise | operator):

PREG_SPLIT_NO_EMPTY: If this flag is set, only non-empty pieces will be returned by preg_split().
PREG_SPLIT_DELIM_CAPTURE: If this flag is set, parenthesized expression in the delimiter pattern will be captured and returned as well. This flag was added for 4.0.5.
PREG_SPLIT_OFFSET_CAPTURE: If this flag is set, for every occuring match the appendant string offset will also be returned. Note that this changes the return value in an array where every element is an array consisting of the matched string at offset 0 and it's string offset into subject at offset 1. This flag is available since PHP 4.3.0 .

Example 1. preg_split() example : Get the parts of a search string.
// split the phrase by any number of commas or space characters, // which include " ", \r, \t, \n and \f $keywords = preg_split ("/[\s,]+/", "hypertext language, programming");

Example 2. Splitting a string into component characters.
$str = 'string'; $chars = preg_split('//', $str, -1, PREG_SPLIT_NO_EMPTY); print_r($chars);

Example 3. Splitting a string into matches and their offsets.
$str = 'hypertext language programming'; $chars = preg_split('/ /', $str, -1, PREG_SPLIT_OFFSET_CAPTURE); print_r($chars);
will yield
Array ( [0] => Array ( [0] => hypertext [1] => 0 ) [1] => Array ( [0] => language [1] => 10 ) [2] => Array ( [0] => programming [1] => 19 ) )

LXXXIX. qtdom functions

Warning

Table of Contents
qdom_error -- Returns the error string from the last QDOM operation or FALSE if no errors occured
qdom_tree -- creates a tree of an xml string

qdom_error

(PHP 4 >= 4.0.5)

qdom_error -- Returns the error string from the last QDOM operation or FALSE if no errors occured

Description

string qdom_error ( void)

Warning

This function is currently not documented; only the argument list is available.

qdom_tree

(PHP 4 >= 4.0.4)

qdom_tree -- creates a tree of an xml string

Description

object qdom_tree ( string )

Warning

This function is currently not documented; only the argument list is available.

XC. Regular Expression Functions (POSIX Extended)

Introduction

Note: PHP also supports regular expressions using a Perl-compatible syntax using the PCRE functions. Those functions support non-greedy matching, assertions, conditional subpatterns, and a number of other features not supported by the POSIX-extended regular expression syntax.

Warning

These regular expression functions are not binary-safe. The PCRE functions are.

Regular expressions are used for complex string manipulation in PHP. The functions that support regular expressions are:

ereg()
ereg_replace()
eregi()
eregi_replace()
split()
spliti()

These functions all take a regular expression string as their first argument. PHP uses the POSIX extended regular expressions as defined by POSIX 1003.2. For a full description of POSIX regular expressions see the regex man pages included in the regex directory in the PHP distribution. It's in manpage format, so you'll want to do something along the lines of man /usr/local/src/regex/regex.7 in order to read it.

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Examples

Example 1. Regular Expression Examples
ereg ("abc", $string); /* Returns true if"abc" is found anywhere in $string. */ ereg ("^abc", $string); /* Returns true if "abc"; is found at the beginning of $string. */ ereg ("abc$", $string); /* Returns true if "abc" is found at the end of $string. */ eregi ("(ozilla.[23]|MSIE.3)", $HTTP_USER_AGENT); /* Returns true if client browser is Netscape 2, 3 or MSIE 3. */ ereg ("([[:alnum:]]+) ([[:alnum:]]+) ([[:alnum:]]+)", $string,$regs); /* Places three space separated words into $regs[1], $regs[2] and $regs[3]. */ $string = ereg_replace ("^", "<br />", $string); /* Put a <br /> tag at the beginning of $string. */ $string = ereg_replace ("$", "<br />", $string); /* Put a <br />; tag at the end of $string. */ $string = ereg_replace ("\n", "", $string); /* Get rid of any newline characters in $string. */

ereg_replace

(PHP 3, PHP 4 )

ereg_replace -- Replace regular expression

Description

string ereg_replace ( string pattern, string replacement, string string)

Note: preg_replace(), which uses a Perl-compatible regular expression syntax, is often a faster alternative to ereg_replace().

This function scans string for matches to pattern, then replaces the matched text with replacement.

The modified string is returned. (Which may mean that the original string is returned if there are no matches to be replaced.)

If pattern contains parenthesized substrings, replacement may contain substrings of the form \\digit, which will be replaced by the text matching the digit'th parenthesized substring; \\0 will produce the entire contents of string. Up to nine substrings may be used. Parentheses may be nested, in which case they are counted by the opening parenthesis.

If no matches are found in string, then string will be returned unchanged.

For example, the following code snippet prints "This was a test" three times:
Example 1. ereg_replace() Example
$string = "This is a test"; echo ereg_replace (" is", " was", $string); echo ereg_replace ("( )is", "\\1was", $string); echo ereg_replace ("(( )is)", "\\2was", $string);

One thing to take note of is that if you use an integer value as the replacement parameter, you may not get the results you expect. This is because ereg_replace() will interpret the number as the ordinal value of a character, and apply that. For instance:
Example 2. ereg_replace() Example
<?php /* This will not work as expected. */ $num = 4; $string = "This string has four words."; $string = ereg_replace('four', $num, $string); echo $string; /* Output: 'This string has words.' */ /* This will work. */ $num = '4'; $string = "This string has four words."; $string = ereg_replace('four', $num, $string); echo $string; /* Output: 'This string has 4 words.' */ ?>

Example 3. Replace URLs with links
$text = ereg_replace("[[:alpha:]]+://[^<>[:space:]]+[[:alnum:]/]", "<a href=\"\\0\">\\0</a>", $text);

ereg

(PHP 3, PHP 4 )

ereg -- Regular expression match

Description

int ereg ( string pattern, string string [, array regs])

Note: preg_match(), which uses a Perl-compatible regular expression syntax, is often a faster alternative to ereg().

Searches a string for matches to the regular expression given in pattern.

If matches are found for parenthesized substrings of pattern and the function is called with the third argument regs, the matches will be stored in the elements of the array regs. $regs[1] will contain the substring which starts at the first left parenthesis; $regs[2] will contain the substring starting at the second, and so on. $regs[0] will contain a copy of the complete string matched.

Note: Up to (and including) PHP 4.1.0 $regs will be filled with exactly ten elements, even though more or fewer than ten parenthesized substrings may actually have matched. This has no effect on ereg()'s ability to match more substrings. If no matches are found, $regs will not be altered by ereg().

Searching is case sensitive.

Returns TRUE if a match for pattern was found in string, or FALSE if no matches were found or an error occurred.

The following code snippet takes a date in ISO format (YYYY-MM-DD) and prints it in DD.MM.YYYY format:
Example 1. ereg() Example
if (ereg ("([0-9]{4})-([0-9]{1,2})-([0-9]{1,2})", $date, $regs)) { echo "$regs[3].$regs[2].$regs[1]"; } else { echo "Invalid date format: $date"; }

eregi_replace

(PHP 3, PHP 4 )

eregi_replace -- replace regular expression case insensitive

Description

string eregi_replace ( string pattern, string replacement, string string)

This function is identical to ereg_replace() except that this ignores case distinction when matching alphabetic characters.

See also ereg(), eregi(), and ereg_replace().

eregi

(PHP 3, PHP 4 )

eregi -- case insensitive regular expression match

Description

int eregi ( string pattern, string string [, array regs])

This function is identical to ereg() except that this ignores case distinction when matching alphabetic characters.
Example 1. eregi() example
if (eregi("z", $string)) { echo "'$string' contains a 'z' or 'Z'!"; }

split

(PHP 3, PHP 4 )

split -- split string into array by regular expression

Description

array split ( string pattern, string string [, int limit])

Note: preg_split(), which uses a Perl-compatible regular expression syntax, is often a faster alternative to split().

Returns an array of strings, each of which is a substring of string formed by splitting it on boundaries formed by the regular expression pattern. If limit is set, the returned array will contain a maximum of limit elements with the last element containing the whole rest of string. If an error occurs, split() returns FALSE.

To split off the first four fields from a line from /etc/passwd:
Example 1. split() Example
list($user,$pass,$uid,$gid,$extra)= split (":", $passwd_line, 5);

Note: If there are n occurrences of pattern, the returned array will contain n+1 items. For example, if there is no occurrence of pattern, an array with only one element will be returned. Of course, this is also true if string is empty.

To parse a date which may be delimited with slashes, dots, or hyphens:
Example 2. split() Example
$date = "04/30/1973"; // Delimiters may be slash, dot, or hyphen list ($month, $day, $year) = split ('[/.-]', $date); echo "Month: $month; Day: $day; Year: $year<br>\n";

Note that pattern is case-sensitive.

Note that if you don't require the power of regular expressions, it is faster to use explode(), which doesn't incur the overhead of the regular expression engine.

For users looking for a way to emulate Perl's @chars = split('', $str) behaviour, please see the examples for preg_split().

Please note that pattern is a regular expression. If you want to split on any of the characters which are considered special by regular expressions, you'll need to escape them first. If you think split() (or any other regex function, for that matter) is doing something weird, please read the file regex.7, included in the regex/ subdirectory of the PHP distribution. It's in manpage format, so you'll want to do something along the lines of man /usr/local/src/regex/regex.7 in order to read it.

spliti

(PHP 4 >= 4.0.1)

spliti -- Split string into array by regular expression case insensitive

Description

array spliti ( string pattern, string string [, int limit])

This function is identical to split() except that this ignores case distinction when matching alphabetic characters.

See also preg_spliti(), split(), explode(), and implode().

sql_regcase

(PHP 3, PHP 4 )

sql_regcase -- Make regular expression for case insensitive match

Description

string sql_regcase ( string string)

Returns a valid regular expression which will match string, ignoring case. This expression is string with each character converted to a bracket expression; this bracket expression contains that character's uppercase and lowercase form if applicable, otherwise it contains the original character twice.
Example 1. sql_regcase() Example
echo sql_regcase ("Foo bar");
prints
[Ff][Oo][Oo] [Bb][Aa][Rr]
.

This can be used to achieve case insensitive pattern matching in products which support only case sensitive regular expressions.

XCI. Semaphore, Shared Memory and IPC Functions

Introduction

This module provides wrappers for the System V IPC family of functions. It includes semaphores, shared memory and inter-process messaging (IPC).

Semaphores may be used to provide exclusive access to resources on the current machine, or to limit the number of processes that may simultaneously use a resource.

This module provides also shared memory functions using System V shared memory. Shared memory may be used to provide access to global variables. Different httpd-daemons and even other programs (such as Perl, C, ...) are able to access this data to provide a global data-exchange. Remember, that shared memory is NOT safe against simultaneous access. Use semaphores for synchronization.

Table 1. Limits of Shared Memory by the Unix OS

SHMMAX	max size of shared memory, normally 131072 bytes
SHMMIN	minimum size of shared memory, normally 1 byte
SHMMNI	max amount of shared memory segments on a system, normally 100
SHMSEG	max amount of shared memory segments per process, normally 6

The messaging functions may be used to send and receive messages to/from other processes. They provide a simple and effective means of exchanging data between processes, without the need for setting up an alternative using unix domain sockets.

Note: These functions do not work on Windows systems.

Requirements

No external libraries are needed to build this extension.

Installation

Support for this functions are not enabled by default. To enable System V semaphore support compile PHP with the option --enable-sysvsem. To enable the System V shared memory support compile PHP with the option --enable-sysvshm. To enable the System V messages support compile PHP with the option --enable-sysvmsg.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 2. Semaphore Configuration Options

Name	Default	Changeable
sysvmsg.value	"42"	PHP_INI_ALL
sysvmsg.string	"foobar"	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Resource Types

Predefined Constants

This extension has no constants defined.

Table of Contents
ftok -- Convert a pathname and a project identifier to a System V IPC key
msg_get_queue -- Create or attach to a message queue
msg_receive -- Receive a message from a message queue
msg_remove_queue -- Destroy a message queue
msg_send -- Send a message to a message queue
msg_set_queue -- Set information in the message queue data structure
msg_stat_queue -- Returns information from the message queue data structure
sem_acquire -- Acquire a semaphore
sem_get -- Get a semaphore id
sem_release -- Release a semaphore
sem_remove -- Remove a semaphore
shm_attach -- Creates or open a shared memory segment
shm_detach -- Disconnects from shared memory segment
shm_get_var -- Returns a variable from shared memory
shm_put_var -- Inserts or updates a variable in shared memory
shm_remove_var -- Removes a variable from shared memory
shm_remove -- Removes shared memory from Unix systems

unserialize defaults to TRUE; if it is set to TRUE, the message is treated as though it was serialized using the same mechanism as the session module. The message will be unserialized and then returned to your script. This allows you to easily receive arrays or complex object structures from other PHP scripts, or if you are using the WDDX serializer, from any WDDX compatible source. If unserialize is FALSE, the message will be returned as a binary-safe string.

The optional flags allows you to pass flags to the low-level msgrcv system call. It defaults to 0, but you may specify one or more of the following values (by adding or ORing them together).

Table 1. Flag values for msg_receive

MSG_IPC_NOWAIT	If there are no messages of the `desiredmsgtype`, return immediately and do not wait. The function will fail and return an integer value corresponding to ENOMSG.
MSG_EXCEPT	Using this flag in combination with a `desiredmsgtype` greater than 0 will cause the function to receive the first message that is not equal to `desiredmsgtype`.
MSG_NOERROR	If the message is longer than `maxsize`, setting this flag will truncate the message to `maxsize` and will not signal an error.

Upon successful completion the message queue data structure is updated as follows: msg_lrpid is set to the process-ID of the calling process, msg_qnum is decremented by 1 and msg_rtime is set to the current time.

msg_receive() returns TRUE on success or FALSE on failure. If the function fails, the optional errorcode will be set to the value of the system errno variable.

This function was introduced in PHP 4.3.0 (not yet released).

msg_remove_queue

(PHP 4 CVS only)

msg_remove_queue -- Destroy a message queue

Description

bool msg_remove_queue ( int queue)

msg_remove_queue() destroys the message queue specified by the queue. Only use this function when all processes have finished working with the message queue and you need to release the system resources held by it.

See also: msg_remove_queue(), msg_receive(), msg_stat_queue() and msg_set_queue().

This function was introduced in PHP 4.3.0 (not yet released).

msg_send

(PHP 4 CVS only)

msg_send -- Send a message to a message queue

Description

bool msg_send ( int queue, int msgtype, mixed message [, bool serialize [, bool blocking [, int errorcode]]])

msg_send() sends a message of type msgtype (which MUST be greater than 0) to a the message queue specified by queue.

If the message is too large to fit in the queue, your script will wait until another process reads messages from the queue and frees enough space for your message to be sent. This is called blocking; you can prevent blocking by setting the optional blocking parameter to FALSE, in which case msg_send() will immediately return FALSE if the message is too big for the queue, and set the optional errorcode to EAGAIN, indicating that you should try to send your message again a little later on.

The optional serialize controls how the message is sent. serialize defaults to TRUE which means that the message is serialized using the same mechanism as the session module before being sent to the queue. This allows complex arrays and objects to be sent to other PHP scripts, or if you are using the WDDX serializer, to any WDDX compatible client.

Upon successful completion the message queue data structure is updated as follows: msg_lspid is set to the process-ID of the calling process, msg_qnum is incremented by 1 and msg_stime is set to the current time.

This function was introduced in PHP 4.3.0 (not yet released).

msg_set_queue

(PHP 4 CVS only)

msg_set_queue -- Set information in the message queue data structure

Description

bool msg_set_queue ( int queue, array data)

msg_set_queue() allows you to change the values of the msg_perm.uid, msg_perm.gid, msg_perm.mode and msg_qbytes fields of the underlying message queue data structure. You specify the values you require by setting the value of the keys that you require in the data array.

Changing the data structure will require that PHP be running as the same user that created the the queue, owns the queue (as determined by the existing msg_perm.xxx fields), or be running with root privileges. root privileges are required to raise the msg_qbytes values above the system defined limit.

See also: msg_remove_queue(), msg_receive(), msg_stat_queue() and msg_set_queue().

This function was introduced in PHP 4.3.0 (not yet released).

msg_stat_queue

(PHP 4 CVS only)

msg_stat_queue -- Returns information from the message queue data structure

Description

array msg_stat_queue ( int queue)

msg_stat_queue() returns the message queue meta data for the message queue specified by the queue. This is useful, for example, to determine which process sent the message that was just received.

The return value is an array whose keys and values have the following meanings:

Table 1. Array structure for msg_stat_queue

msg_perm.uid	The uid of the owner of the queue.
msg_perm.gid	The gid of the owner of the queue.
msg_perm.mode	The file access mode of the queue.
msg_stime	The time that the last message was sent to the queue.
msg_rtime	The time that the last message was received from the queue.
msg_ctime	The time that the queue was last changed.
msg_qnum	The number of messages waiting to be read from the queue.
msg_qbytes	The number of bytes of space currently available in the queue to hold sent messages until they are received.
msg_lspid	The pid of the process that sent the last message to the queue.
msg_lrpid	The pid of the process that received the last message from the queue.

After releasing the semaphore, sem_acquire() may be called to re-acquire it.

See also: sem_get() and sem_acquire().

Note: This function does not work on Windows systems.

sem_remove

(PHP 4 >= 4.1.0)

sem_remove -- Remove a semaphore

Description

bool sem_remove ( int sem_identifier)

Returns: TRUE on success, FALSE on error.

sem_remove() removes the semaphore sem_identifier if it has been created by sem_get(), otherwise generates a warning.

After removing the semaphore, it is no more accessible.

Note: This function does not work on Windows systems. It was added on PHP 4.1.0.

shm_attach

(PHP 3>= 3.0.6, PHP 4 )

shm_attach -- Creates or open a shared memory segment

Description

int shm_attach ( int key [, int memsize [, int perm]])

shm_attach() returns an id that that can be used to access the System V shared memory with the given key, the first call creates the shared memory segment with mem_size (default: sysvshm.init_mem in the configuration file, otherwise 10000 bytes) and the optional perm-bits (default: 0666).

A second call to shm_attach() for the same key will return a different shared memory identifier, but both identifiers access the same underlying shared memory. Memsize and perm will be ignored.

shm_detach

(PHP 3>= 3.0.6, PHP 4 )

shm_detach -- Disconnects from shared memory segment

Description

Removes shared memory from Unix systems. All data will be destroyed.

Note: This function does not work on Windows systems.

XCII. SESAM database functions

Introduction

SESAM/SQL-Server is a mainframe database system, developed by Fujitsu Siemens Computers, Germany. It runs on high-end mainframe servers using the operating system BS2000/OSD.

In numerous productive BS2000 installations, SESAM/SQL-Server has proven

the ease of use of Java-, Web- and client/server connectivity,
the capability to work with an availability of more than 99.99%,
the ability to manage tens and even hundreds of thousands of users.

There is a PHP3 SESAM interface available which allows database operations via PHP-scripts.

Note: Access to SESAM is only available with the latest CVS-Version of PHP3. PHP 4 does not support the SESAM database.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

sesam_oml string

Name of BS2000 PLAM library containing the loadable SESAM driver modules. Required for using SESAM functions. The BS2000 PLAM library must be set ACCESS=READ,SHARE=YES because it must be readable by the apache server's user id.

sesam_configfile string

Name of SESAM application configuration file. Required for using SESAM functions. The BS2000 file must be readable by the apache server's user id.

The application configuration file will usually contain a configuration like (see SESAM reference manual):

CNF=B
NAM=K
NOTYPE

sesam_messagecatalog string

Name of SESAM message catalog file. In most cases, this directive is not neccessary. Only if the SESAM message file is not installed in the system's BS2000 message file table, it can be set with this directive.

The message catalog must be set ACCESS=READ,SHARE=YES because it must be readable by the apache server's user id.

Configuration notes

There is no standalone support for the PHP SESAM interface, it works only as an integrated Apache module. In the Apache PHP module, this SESAM interface is configured using Apache directives.

Table 1. SESAM Configuration directives

Directive Meaning

php3_sesam_oml

Name of BS2000 PLAM library containing the loadable SESAM driver modules. Required for using SESAM functions.

Example:

php3_sesam_oml $.SYSLNK.SESAM-SQL.030

php3_sesam_configfile

Name of SESAM application configuration file. Required for using SESAM functions.

Example:

php3_sesam_configfile $SESAM.SESAM.CONF.AW

It will usually contain a configuration like (see SESAM reference manual):

CNF=B
NAM=K
NOTYPE

php3_sesam_messagecatalog

Example:

php3_sesam_messagecatalog $.SYSMES.SESAM-SQL.030

In addition to the configuration of the PHP/SESAM interface, you have to configure the SESAM-Database server itself on your mainframe as usual. That means:

starting the SESAM database handler (DBH), and
connecting the databases with the SESAM database handler

To get a connection between a PHP script and the database handler, the CNF and NAM parameters of the selected SESAM configuration file must match the id of the started database handler.

In case of distributed databases you have to start a SESAM/SQL-DCN agent with the distribution table including the host and database names.

The communication between PHP (running in the POSIX subsystem) and the database handler (running outside the POSIX subsystem) is realized by a special driver module called SQLSCI and SESAM connection modules using common memory. Because of the common memory access, and because PHP is a static part of the web server, database accesses are very fast, as they do not require remote accesses via ODBC, JDBC or UTM.

Only a small stub loader (SESMOD) is linked with PHP, and the SESAM connection modules are pulled in from SESAM's OML PLAM library. In the configuration, you must tell PHP the name of this PLAM library, and the file link to use for the SESAM configuration file (As of SESAM V3.0, SQLSCI is available in the SESAM Tool Library, which is part of the standard distribution).

Because the SQL command quoting for single quotes uses duplicated single quotes (as opposed to a single quote preceded by a backslash, used in some other databases), it is advisable to set the PHP configuration directives php3_magic_quotes_gpc and php3_magic_quotes_sybase to On for all PHP scripts using the SESAM interface.

Runtime considerations

Because of limitations of the BS2000 process model, the driver can be loaded only after the Apache server has forked off its server child processes. This will slightly slow down the initial SESAM request of each child, but subsequent accesses will respond at full speed.

When explicitly defining a Message Catalog for SESAM, that catalog will be loaded each time the driver is loaded (i.e., at the initial SESAM request). The BS2000 operating system prints a message after successful load of the message catalog, which will be sent to Apache's error_log file. BS2000 currently does not allow suppression of this message, it will slowly fill up the log.

Make sure that the SESAM OML PLAM library and SESAM configuration file are readable by the user id running the web server. Otherwise, the server will be unable to load the driver, and will not allow to call any SESAM functions. Also, access to the database must be granted to the user id under which the Apache server is running. Otherwise, connections to the SESAM database handler will fail.

Cursor Types

The result cursors which are allocated for SQL "select type" queries can be either "sequential" or "scrollable". Because of the larger memory overhead needed by "scrollable" cursors, the default is "sequential".

When using "scrollable" cursors, the cursor can be freely positioned on the result set. For each "scrollable" query, there are global default values for the scrolling type (initialized to: SESAM_SEEK_NEXT) and the scrolling offset which can either be set once by sesam_seek_row() or each time when fetching a row using sesam_fetch_row(). When fetching a row using a "scrollable" cursor, the following post-processing is done for the global default values for the scrolling type and scrolling offset:

Table 2. Scrolled Cursor Post-Processing

Scroll Type	Action
`SESAM_SEEK_NEXT`	none
`SESAM_SEEK_PRIOR`	none
`SESAM_SEEK_FIRST`	set scroll type to `SESAM_SEEK_NEXT`
`SESAM_SEEK_LAST`	set scroll type to `SESAM_SEEK_PRIOR`
`SESAM_SEEK_ABSOLUTE`	Auto-Increment internal offset value
`SESAM_SEEK_RELATIVE`	none. (maintain global default `offset` value, which allows for, e.g., fetching each 10th row backwards)

Porting note

Because in the PHP world it is natural to start indexes at zero (rather than 1), some adaptions have been made to the SESAM interface: whenever an indexed array is starting with index 1 in the native SESAM interface, the PHP interface uses index 0 as a starting point. E.g., when retrieving columns with sesam_fetch_row(), the first column has the index 0, and the subsequent columns have indexes up to (but not including) the column count ($array["count"]). When porting SESAM applications from other high level languages to PHP, be aware of this changed interface. Where appropriate, the description of the respective php sesam functions include a note that the index is zero based.

Security concerns

When allowing access to the SESAM databases, the web server user should only have as little privileges as possible. For most databases, only read access privilege should be granted. Depending on your usage scenario, add more access rights as you see fit. Never allow full control to any database for any user from the 'net! Restrict access to php scripts which must administer the database by using password control and/or SSL security.

Migration from other SQL databases

No two SQL dialects are ever 100% compatible. When porting SQL applications from other database interfaces to SESAM, some adaption may be required. The following typical differences should be noted:

Vendor specific data types
Some vendor specific data types may have to be replaced by standard SQL data types (e.g., TEXT could be replaced by VARCHAR(max. size)).
Keywords as SQL identifiers
In SESAM (as in standard SQL), such identifiers must be enclosed in double quotes (or renamed).
Display length in data types
SESAM data types have a precision, not a display length. Instead of int(4) (intended use: integers up to '9999'), SESAM requires simply int for an implied size of 31 bits. Also, the only datetime data types available in SESAM are: DATE, TIME(3) and TIMESTAMP(3).
SQL types with vendor-specific unsigned, zerofill, or auto_increment attributes
Unsigned and zerofill are not supported. Auto_increment is automatic (use "INSERT ... VALUES(*, ...)" instead of "... VALUES(0, ...)" to take advantage of SESAM-implied auto-increment.
int ... DEFAULT '0000'
Numeric variables must not be initialized with string constants. Use DEFAULT 0 instead. To initialize variables of the datetime SQL data types, the initialization string must be prefixed with the respective type keyword, as in: CREATE TABLE exmpl ( xtime timestamp(3) DEFAULT TIMESTAMP '1970-01-01 00:00:00.000' NOT NULL );
$count = xxxx_num_rows();
Some databases promise to guess/estimate the number of the rows in a query result, even though the returned value is grossly incorrect. SESAM does not know the number of rows in a query result before actually fetching them. If you REALLY need the count, try SELECT COUNT(...) WHERE ..., it will tell you the number of hits. A second query will (hopefully) return the results.
DROP TABLE thename;
In SESAM, in the DROP TABLE command, the table name must be either followed by the keyword RESTRICT or CASCADE. When specifying RESTRICT, an error is returned if there are dependent objects (e.g., VIEWs), while with CASCADE, dependent objects will be deleted along with the specified table.

Notes on the use of various SQL types

SESAM does not currently support the BLOB type. A future version of SESAM will have support for BLOB.

At the PHP interface, the following type conversions are automatically applied when retrieving SQL fields:

Table 3. SQL to PHP Type Conversions

SQL Type	PHP Type
SMALLINT, INTEGER	integer
NUMERIC, DECIMAL, FLOAT, REAL, DOUBLE	float
DATE, TIME, TIMESTAMP	string
VARCHAR, CHARACTER	string

When retrieving a complete row, the result is returned as an array. Empty fields are not filled in, so you will have to check for the existence of the individual fields yourself (use isset() or empty() to test for empty fields). That allows more user control over the appearance of empty fields (than in the case of an empty string as the representation of an empty field).

Support of SESAM's "multiple fields" feature

if (!sesam_execimm ($stmt))
  printf ("%s<br>\n", sesam_errormsg());

See also: sesam_diagnostic() for the full set of SESAM SQL status information

sesam_execimm

(PHP 3 CVS only)

sesam_execimm -- Execute an "immediate" SQL-statement

Description

string sesam_execimm ( string query)

Returns: A SESAM "result identifier" on success, or FALSE on error.

sesam_execimm() executes an "immediate" statement (i.e., a statement like UPDATE, INSERT or DELETE which returns no result, and has no INPUT or OUTPUT variables). "select type" queries can not be used with sesam_execimm(). Sets the affected_rows value for retrieval by the sesam_affected_rows() function.

Note that sesam_query() can handle both "immediate" and "select-type" queries. Use sesam_execimm() only if you know beforehand what type of statement will be executed. An attempt to use SELECT type queries with sesam_execimm() will return $err["sqlstate"] == "42SBW".

The returned "result identifier" can not be used for retrieving anything but the sesam_affected_rows(); it is only returned for symmetry with the sesam_query() function.

$stmt = "INSERT INTO mytable VALUES ('one', 'two')";
$result = sesam_execimm ($stmt);
$err = sesam_diagnostic();
print ("sqlstate = ".$err["sqlstate"]."\n".
       "Affected rows = ".$err["rowcount"]." == ".
       sesam_affected_rows($result)."\n");

See also: sesam_query() and sesam_affected_rows().

sesam_fetch_array

(PHP 3 CVS only)

sesam_fetch_array -- Fetch one row as an associative array

Description

array sesam_fetch_array ( string result_id [, int whence [, int offset]])

Returns an array that corresponds to the fetched row, or FALSE if there are no more rows.

sesam_fetch_array() is an alternative version of sesam_fetch_row(). Instead of storing the data in the numeric indices of the result array, it stores the data in associative indices, using the field names as keys.

result_id is a valid result id returned by sesam_query() (select type queries only!).

For the valid values of the optional whenceand offset parameters, see the sesam_fetch_row() function for details.

sesam_fetch_array() fetches one row of data from the result associated with the specified result identifier. The row is returned as an associative array. Each result column is stored with an associative index equal to its column (aka. field) name. The column names are converted to lower case.

Columns without a field name (e.g., results of arithmetic operations) and empty fields are not stored in the array. Also, if two or more columns of the result have the same column names, the later column will take precedence. In this situation, either call sesam_fetch_row() or make an alias for the column.

SELECT TBL1.COL AS FOO, TBL2.COL AS BAR FROM TBL1, TBL2

A special handling allows fetching "multiple field" columns (which would otherwise all have the same column names). For each column of a "multiple field", the index name is constructed by appending the string "(n)" where n is the sub-index of the multiple field column, ranging from 1 to its declared repetition factor. The indices are NOT zero based, in order to match the nomenclature used in the respective query syntax. For a column declared as:

CREATE TABLE ... ( ... MULTI(3) INT )

the associative indices used for the individual "multiple field" columns would be "multi(1)", "multi(2)", and "multi(3)" respectively.

Subsequent calls to sesam_fetch_array() would return the next (or prior, or n'th next/prior, depending on the scroll attributes) row in the result set, or FALSE if there are no more rows.

Example 1. SESAM fetch array

<?php
$result = sesam_query ("SELECT * FROM phone\n".
                       "  WHERE LASTNAME='".strtoupper($name)."'\n".
                       "  ORDER BY FIRSTNAME", 1);
if (!$result) {
    ... error ...
}
// print the table:
print "<TABLE BORDER>\n";
while (($row = sesam_fetch_array ($result)) && count ($row) > 0) {
    print " <TR>\n";
    print " <TD>".htmlspecialchars ($row["firstname"])."</TD>\n";
    print " <TD>".htmlspecialchars ($row["lastname"])."</TD>\n";
    print " <TD>".htmlspecialchars ($row["phoneno"])."</TD>\n";
    print " </TR>\n";
}
print "</TABLE>\n";
sesam_free_result ($result);
?>

See also: sesam_fetch_row() which returns an indexed array.

sesam_fetch_result

(PHP 3 CVS only)

sesam_fetch_result -- Return all or part of a query result

Description

mixed sesam_fetch_result ( string result_id [, int max_rows])

Returns a mixed array with the query result entries, optionally limited to a maximum of max_rows rows. Note that both row and column indexes are zero-based.

Table 1. Mixed result set returned by sesam_fetch_result()

Array Element	Contents
int $arr["count"]	number of columns in result set (or zero if this was an "immediate" query)
int $arr["rows"]	number of rows in result set (between zero and `max_rows`)
bool $arr["truncated"]	`TRUE` if the number of rows was at least `max_rows`, `FALSE` otherwise. Note that even when this is `TRUE`, the next sesam_fetch_result() call may return zero rows because there are no more result entries.
mixed $arr[col][row]	result data for all the fields at row(`row`) and column(`col`), (where the integer index `row` is between 0 and `$arr["rows"]-1`, and `col` is between 0 and `$arr["count"]-1`). Fields may be empty, so you must check for the existence of a field by using the php isset() function. The type of the returned fields depend on the respective SQL type declared for its column (see SESAM overview for the conversions applied). SESAM "multiple fields" are "inlined" and treated like a sequence of columns.

Note that the amount of memory used up by a large query may be gigantic. Use the max_rows parameter to limit the maximum number of rows returned, unless you are absolutely sure that your result will not use up all available memory.

See also: sesam_fetch_row(), and sesam_field_array() to check for "multiple fields". See the description of the sesam_query() function for a complete example using sesam_fetch_result().

sesam_fetch_row

(PHP 3 CVS only)

sesam_fetch_row -- Fetch one row as an array

Description

array sesam_fetch_row ( string result_id [, int whence [, int offset]])

Returns an array that corresponds to the fetched row, or FALSE if there are no more rows.

The number of columns in the result set is returned in an associative array element $array["count"]. Because some of the result columns may be empty, the count() function can not be used on the result row returned by sesam_fetch_row().

result_id is a valid result id returned by sesam_query() (select type queries only!).

whence is an optional parameter for a fetch operation on "scrollable" cursors, which can be set to the following predefined constants:

Table 1. Valid values for "whence" parameter

Value	Constant	Meaning
0	`SESAM_SEEK_NEXT`	read sequentially (after fetch, the internal default is set to `SESAM_SEEK_NEXT`)
1	`SESAM_SEEK_PRIOR`	read sequentially backwards (after fetch, the internal default is set to `SESAM_SEEK_PRIOR`)
2	`SESAM_SEEK_FIRST`	rewind to first row (after fetch, the default is set to `SESAM_SEEK_NEXT`)
3	`SESAM_SEEK_LAST`	seek to last row (after fetch, the default is set to `SESAM_SEEK_PRIOR`)
4	`SESAM_SEEK_ABSOLUTE`	seek to absolute row number given as `offset` (Zero-based. After fetch, the internal default is set to `SESAM_SEEK_ABSOLUTE`, and the internal offset value is auto-incremented)
5	`SESAM_SEEK_RELATIVE`	seek relative to current scroll position, where `offset` can be a positive or negative offset value.

This parameter is only valid for "scrollable" cursors.

When using "scrollable" cursors, the cursor can be freely positioned on the result set. If the whence parameter is omitted, the global default values for the scrolling type (initialized to: SESAM_SEEK_NEXT, and settable by sesam_seek_row()) are used. If whence is supplied, its value replaces the global default.

offset is an optional parameter which is only evaluated (and required) if whence is either SESAM_SEEK_RELATIVE or SESAM_SEEK_ABSOLUTE. This parameter is only valid for "scrollable" cursors.

sesam_fetch_row() fetches one row of data from the result associated with the specified result identifier. The row is returned as an array (indexed by values between 0 and $array["count"]-1). Fields may be empty, so you must check for the existence of a field by using the php isset() function. The type of the returned fields depend on the respective SQL type declared for its column (see SESAM overview for the conversions applied). SESAM "multiple fields" are "inlined" and treated like a sequence of columns.

Subsequent calls to sesam_fetch_row() would return the next (or prior, or n'th next/prior, depending on the scroll attributes) row in the result set, or FALSE if there are no more rows.

Example 1. SESAM fetch rows

<?php
$result = sesam_query ("SELECT * FROM phone\n".
                       "  WHERE LASTNAME='".strtoupper($name)."'\n".
                       "  ORDER BY FIRSTNAME", 1);
if (!$result) {
    ... error ...
}
// print the table in backward order
print "<TABLE BORDER>\n";
$row = sesam_fetch_row ($result, SESAM_SEEK_LAST);
while (is_array ($row)) {
    print " <TR>\n";
    for ($col = 0; $col < $row["count"]; ++$col) {
        print "  <TD>".htmlspecialchars ($row[$col])."</TD>\n";
    }
    print " </TR>\n";
    // use implied SESAM_SEEK_PRIOR
    $row = sesam_fetch_row ($result);
}
print "</TABLE>\n";
sesam_free_result ($result);
?>

See also: sesam_fetch_array() which returns an associative array, and sesam_fetch_result() which returns many rows per invocation.

sesam_field_array

(PHP 3 CVS only)

sesam_field_array -- Return meta information about individual columns in a result

Description

array sesam_field_array ( string result_id)

result_id is a valid result id returned by sesam_query().

Returns a mixed associative/indexed array with meta information (column name, type, precision, ...) about individual columns of the result after the query associated with result_id.

Table 1. Mixed result set returned by sesam_field_array()

Array Element	Contents
int $arr["count"]	Total number of columns in result set (or zero if this was an "immediate" query). SESAM "multiple fields" are "inlined" and treated like the respective number of columns.
string $arr[col]["name"]	column name for column(`col`), where `col` is between 0 and `$arr["count"]-1`. The returned value can be the empty string (for dynamically computed columns). SESAM "multiple fields" are "inlined" and treated like the respective number of columns, each with the same column name.
string $arr[col]["count"]	The "count" attribute describes the repetition factor when the column has been declared as a "multiple field". Usually, the "count" attribute is 1. The first column of a "multiple field" column however contains the number of repetitions (the second and following column of the "multiple field" contain a "count" attribute of 1). This can be used to detect "multiple fields" in the result set. See the example shown in the sesam_query() description for a sample use of the "count" attribute.
string $arr[col]["type"]	php variable type of the data for column(`col`), where `col` is between 0 and `$arr["count"]-1`. The returned value can be one of integer float string depending on the SQL type of the result. SESAM "multiple fields" are "inlined" and treated like the respective number of columns, each with the same php type.
string $arr[col]["sqltype"]	SQL variable type of the column data for column(`col`), where `col` is between 0 and `$arr["count"]-1`. The returned value can be one of "CHARACTER" "VARCHAR" "NUMERIC" "DECIMAL" "INTEGER" "SMALLINT" "FLOAT" "REAL" "DOUBLE" "DATE" "TIME" "TIMESTAMP" describing the SQL type of the result. SESAM "multiple fields" are "inlined" and treated like the respective number of columns, each with the same SQL type.
string $arr[col]["length"]	The SQL "length" attribute of the SQL variable in column(`col`), where `col` is between 0 and `$arr["count"]-1`. The "length" attribute is used with "CHARACTER" and "VARCHAR" SQL types to specify the (maximum) length of the string variable. SESAM "multiple fields" are "inlined" and treated like the respective number of columns, each with the same length attribute.
string $arr[col]["precision"]	The "precision" attribute of the SQL variable in column(`col`), where `col` is between 0 and `$arr["count"]-1`. The "precision" attribute is used with numeric and time data types. SESAM "multiple fields" are "inlined" and treated like the respective number of columns, each with the same precision attribute.
string $arr[col]["scale"]	The "scale" attribute of the SQL variable in column(`col`), where `col` is between 0 and `$arr["count"]-1`. The "scale" attribute is used with numeric data types. SESAM "multiple fields" are "inlined" and treated like the respective number of columns, each with the same scale attribute.

See the sesam_query() function for an example of the sesam_field_array() use.

sesam_field_name

(PHP 3 CVS only)

sesam_field_name -- Return one column name of the result set

Description

int sesam_field_name ( string result_id, int index)

Returns the name of a field (i.e., the column name) in the result set, or FALSE on error.

For "immediate" queries, or for dynamic columns, an empty string is returned.

Note: The column index is zero-based, not one-based as in SESAM.

See also: sesam_field_array(). It provides an easier interface to access the column names and types, and allows for detection of "multiple fields".

sesam_free_result

(PHP 3 CVS only)

sesam_free_result -- Releases resources for the query

Description

int sesam_free_result ( string result_id)

Releases resources for the query associated with result_id. Returns FALSE on error.

sesam_num_fields

(PHP 3 CVS only)

sesam_num_fields -- Return the number of fields/columns in a result set

Description

int sesam_num_fields ( string result_id)

After calling sesam_query() with a "select type" query, this function gives you the number of columns in the result. Returns an integer describing the total number of columns (aka. fields) in the current result_id result set or FALSE on error.

For "immediate" statements, the value zero is returned. The SESAM "multiple field" columns count as their respective dimension, i.e., a three-column "multiple field" counts as three columns.

See also: sesam_query() and sesam_field_array() for a way to distinguish between "multiple field" columns and regular columns.

sesam_query

(PHP 3 CVS only)

sesam_query -- Perform a SESAM SQL query and prepare the result

Description

string sesam_query ( string query [, bool scrollable])

Returns: A SESAM "result identifier" on success, or FALSE on error.

A "result_id" resource is used by other functions to retrieve the query results.

sesam_query() sends a query to the currently active database on the server. It can execute both "immediate" SQL statements and "select type" queries. If an "immediate" statement is executed, then no cursor is allocated, and any subsequent sesam_fetch_row() or sesam_fetch_result() call will return an empty result (zero columns, indicating end-of-result). For "select type" statements, a result descriptor and a (scrollable or sequential, depending on the optional boolean scrollable parameter) cursor will be allocated. If scrollable is omitted, the cursor will be sequential.

For "immediate" statements, the number of affected rows is saved for retrieval by the sesam_affected_rows() function.

See also: sesam_fetch_row() and sesam_fetch_result().
Example 1. Show all rows of the "phone" table as a html table
<?php if (!sesam_connect ("phonedb", "demo", "otto")) die ("cannot connect"); $result = sesam_query ("select * from phone"); if (!$result) { $err = sesam_diagnostic(); die ($err["errmsg"]); } echo "<TABLE BORDER>\n"; // Add title header with column names above the result: if ($cols = sesam_field_array ($result)) { echo " <TR><TH COLSPAN=".$cols["count"].">Result:</TH></TR>\n"; echo " <TR>\n"; for ($col = 0; $col < $cols["count"]; ++$col) { $colattr = $cols[$col]; /* Span the table head over SESAM's "Multiple Fields": */ if ($colattr["count"] > 1) { echo " <TH COLSPAN=".$colattr["count"].">".$colattr["name"]. "(1..".$colattr["count"].")</TH>\n"; $col += $colattr["count"] - 1; } else echo " <TH>" . $colattr["name"] . "</TH>\n"; } echo " </TR>\n"; } do { // Fetch the result in chunks of 100 rows max. $ok = sesam_fetch_result ($result, 100); for ($row=0; $row < $ok["rows"]; ++$row) { echo " <TR>\n"; for ($col = 0; $col < $ok["cols"]; ++$col) { if (isset($ok[$col][$row])) echo " <TD>" . $ok[$col][$row] . "</TD>\n"; } else { echo " <TD>-empty-</TD>\n"; } } echo " </TR>\n"; } } while ($ok["truncated"]) { // while there may be more data echo "</TABLE>\n"; } // free result id sesam_free_result($result); ?>

sesam_rollback

(PHP 3 CVS only)

sesam_rollback -- Discard any pending updates to the SESAM database

Description

bool sesam_rollback ( void)

Returns: TRUE on success, FALSE on errors

sesam_rollback() discards any pending updates to the database. Also affected are result cursors and result descriptors.

At the end of each script, and as part of the sesam_disconnect() function, an implied sesam_rollback() is executed, discarding any pending changes to the database.

See also: sesam_commit().
Example 1. Discarding an update to the SESAM database
<?php if (sesam_connect ("mycatalog", "myschema", "otto")) { if (sesam_execimm ("INSERT INTO mytable VALUES (*, 'Small Test', <0, 8, 15>)") && sesam_execimm ("INSERT INTO othertable VALUES (*, 'Another Test', 1)")) sesam_commit(); else sesam_rollback(); } ?>

sesam_seek_row

(PHP 3 CVS only)

sesam_seek_row -- Set scrollable cursor mode for subsequent fetches

Description

bool sesam_seek_row ( string result_id, int whence [, int offset])

result_id is a valid result id (select type queries only, and only if a "scrollable" cursor was requested when calling sesam_query()).

whence sets the global default value for the scrolling type, it specifies the scroll type to use in subsequent fetch operations on "scrollable" cursors, which can be set to the following predefined constants:

Table 1. Valid values for "whence" parameter

Value	Constant	Meaning
0	`SESAM_SEEK_NEXT`	read sequentially
1	`SESAM_SEEK_PRIOR`	read sequentially backwards
2	`SESAM_SEEK_FIRST`	fetch first row (after fetch, the default is set to `SESAM_SEEK_NEXT`)
3	`SESAM_SEEK_LAST`	fetch last row (after fetch, the default is set to `SESAM_SEEK_PRIOR`)
4	`SESAM_SEEK_ABSOLUTE`	fetch absolute row number given as `offset` (Zero-based. After fetch, the default is set to `SESAM_SEEK_ABSOLUTE`, and the offset value is auto-incremented)
5	`SESAM_SEEK_RELATIVE`	fetch relative to current scroll position, where `offset` can be a positive or negative offset value (this also sets the default "offset" value for subsequent fetches).

offset is an optional parameter which is only evaluated (and required) if whence is either SESAM_SEEK_RELATIVE or SESAM_SEEK_ABSOLUTE.

sesam_settransaction

(PHP 3 CVS only)

sesam_settransaction -- Set SESAM transaction parameters

Description

bool sesam_settransaction ( int isolation_level, int read_only)

Returns: TRUE if the values are valid, and the settransaction() operation was successful, FALSE otherwise.

sesam_settransaction() overrides the default values for the "isolation level" and "read-only" transaction parameters (which are set in the SESAM configuration file), in order to optimize subsequent queries and guarantee database consistency. The overridden values are used for the next transaction only.

sesam_settransaction() can only be called before starting a transaction, not after the transaction has been started already.

To simplify the use in php scripts, the following constants have been predefined in php (see SESAM handbook for detailed explanation of the semantics):

Table 1. Valid values for "Isolation_Level" parameter

Value	Constant	Meaning
1	`SESAM_TXISOL_READ_UNCOMMITTED`	Read Uncommitted
2	`SESAM_TXISOL_READ_COMMITTED`	Read Committed
3	`SESAM_TXISOL_REPEATABLE_READ`	Repeatable Read
4	`SESAM_TXISOL_SERIALIZABLE`	Serializable

Table 2. Valid values for "Read_Only" parameter

Value	Constant	Meaning
0	`SESAM_TXREAD_READWRITE`	Read/Write
1	`SESAM_TXREAD_READONLY`	Read-Only

The values set by sesam_settransaction() will override the default setting specified in the SESAM configuration file.

Example 1. Setting SESAM transaction parameters
<?php sesam_settransaction (SESAM_TXISOL_REPEATABLE_READ, SESAM_TXREAD_READONLY); ?>

XCIII. Session handling functions

Introduction

Session support in PHP consists of a way to preserve certain data across subsequent accesses. This enables you to build more customized applications and increase the appeal of your web site.

If you are familiar with the session management of PHPLIB, you will notice that some concepts are similar to PHP's session support.

A visitor accessing your web site is assigned an unique id, the so-called session id. This is either stored in a cookie on the user side or is propagated in the URL.

The session support allows you to register arbitrary numbers of variables to be preserved across requests. When a visitor accesses your site, PHP will check automatically (if session.auto_start is set to 1) or on your request (explicitly through session_start() or implicitly through session_register()) whether a specific session id has been sent with the request. If this is the case, the prior saved environment is recreated.

All registered variables are serialized after the request finishes. Registered variables which are undefined are marked as being not defined. On subsequent accesses, these are not defined by the session module unless the user defines them later.

Note: Session handling was added in PHP 4.0.

Sessions and security

Using sessions, does not mean, you can be absolutely sure, that the session data can only be viewed by that user. This is important to keep in mind, when storing and displaying sensitive information. When storing data into a session, one should always ask themselves, what the damage is, when somebody else views that information, or how your application is affected when this session is actually somebody else.

For instance, if somebody else takes a session, can he then post a message in a forum, as that user and how big of a problem is that? Or perhaps he can view what the original user was thinking of ordering, because he gets access to that user's shopping cart. Obviously for a flowershop, this is less dramatic, than for a pharmacy.

Therefore, when dealing with sensitive information, there should always be additional methods to decide whether it is a valid session. Sessions are not reliable as a secure authentication mechanism.

Sessions rely on the session ID, meaning one can 'steal' a session, by stealing the session ID. This can be made harder, by using a cookie specifically a session cookie, but does not in any way make it impossible and still relies on the user closing all browser windows, to expire the session cookie. Besides that, even session cookies can be sniffed on a network or logged by a proxyserver.

Requirements

No external libraries are needed to build this extension.

Installation

Session support is enabled in PHP by default. If you would not like to build your PHP with session support, you should specify the --disable-session option to configure.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Session configuration options

Name	Default	Changeable
session.save_path	"/tmp"	PHP_INI_ALL
session.name	"PHPSESSID"	PHP_INI_ALL
session.save_handler	"files"	PHP_INI_ALL
session.auto_start	"0"	PHP_INI_ALL
session.gc_probability	"1"	PHP_INI_ALL
session.gc_maxlifetime	"1440"	PHP_INI_ALL
session.serialize_handler	"php"	PHP_INI_ALL
session.cookie_lifetime	"0"	PHP_INI_ALL
session.cookie_path	"/"	PHP_INI_ALL
session.cookie_domain	""	PHP_INI_ALL
session.cookie_secure	""	PHP_INI_ALL
session.use_cookies	"1"	PHP_INI_ALL
session.use_only_cookies	"0"	PHP_INI_ALL
session.referer_check	""	PHP_INI_ALL
session.entropy_file	""	PHP_INI_ALL
session.entropy_length	"0"	PHP_INI_ALL
session.cache_limiter	"nocache"	PHP_INI_ALL
session.cache_expire	"180"	PHP_INI_ALL
session.use_trans_sid	"0"	PHP_INI_SYSTEM\|PHP_INI_PERDIR
url_rewriter.tags	"a=href,area=href,frame=src,input=src,form=fakeentry"	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

The session management system supports a number of configuration options which you can place in your php.ini file. We will give a short overview.

session.save_handler defines the name of the handler which is used for storing and retrieving data associated with a session. Defaults to files.

session.save_path defines the argument which is passed to the save handler. If you choose the default files handler, this is the path where the files are created. Defaults to /tmp. If session.save_path's path depth is more than 2, garbage collection will not be performed.

Warning

If you leave this set to a world-readable directory, such as /tmp (the default), other users on the server may be able to hijack sessions by getting the list of files in that directory.

Note: Windows users have to change this variable in order to use PHP's session functions. Make sure to specify a valid path, e.g.: c:/temp.

session.name specifies the name of the session which is used as cookie name. It should only contain alphanumeric characters. Defaults to PHPSESSID.
session.auto_start specifies whether the session module starts a session automatically on request startup. Defaults to 0 (disabled).
session.cookie_lifetime specifies the lifetime of the cookie in seconds which is sent to the browser. The value 0 means "until the browser is closed." Defaults to 0.
session.serialize_handler defines the name of the handler which is used to serialize/deserialize data. Currently, a PHP internal format (name php) and WDDX is supported (name wddx). WDDX is only available, if PHP is compiled with WDDX support. Defaults to php.
session.gc_probability specifies the probability that the gc (garbage collection) routine is started on each request in percent. Defaults to 1.
session.gc_maxlifetime specifies the number of seconds after which data will be seen as 'garbage' and cleaned up.
Note: If you are using the default file-based session handler, your filesystem must keep track of access times (atime). Windows FAT does not so you will have to come up with another way to handle garbage collecting your session if you are stuck with a FAT filesystem or any other fs where atime tracking is not available.
session.referer_check contains the substring you want to check each HTTP Referer for. If the Referer was sent by the client and the substring was not found, the embedded session id will be marked as invalid. Defaults to the empty string.
session.entropy_file gives a path to an external resource (file) which will be used as an additional entropy source in the session id creation process. Examples are /dev/random or /dev/urandom which are available on many Unix systems.
session.entropy_length specifies the number of bytes which will be read from the file specified above. Defaults to 0 (disabled).
session.use_cookies specifies whether the module will use cookies to store the session id on the client side. Defaults to 1 (enabled).
session.use_only_cookies specifies whether the module will only use cookies to store the session id on the client side. Defaults to 0 (disabled, for backward compatibility). Enabling this setting prevents attacks involved passing session ids in URLs. This setting was added in PHP 4.3.0.
session.cookie_path specifies path to set in session_cookie. Defaults to /.
session.cookie_domain specifies domain to set in session_cookie. Default is none at all.
session.cache_limiter specifies cache control method to use for session pages (none/nocache/private/private_no_expire/public). Defaults to nocache.
session.cache_expire specifies time-to-live for cached session pages in minutes, this has no effect for nocache limiter. Defaults to 180.
session.use_trans_sid whether transparent sid support is enabled or not. Defaults to 0 (disabled).
Note: For PHP 4.1.2 or less, it is enabled by compiling with --enable-trans-sid. From PHP 4.2.0, trans-sid feature is always compiled.
URL based session management has additional security risks compared to cookie based session management. Users may send an URL that contains an active session ID to their friends by email or users may save an URL that contains a session ID to their bookmarks and access your site with the same session ID always, for example.
url_rewriter.tags specifies which html tags are rewritten to include session id if transparent sid support is enabled. Defaults to a=href,area=href,frame=src,input=src,form=fakeentry

The track_vars and register_globals configuration settings influence how the session variables get stored and restored.

Note: As of PHP 4.0.3, track_vars is always turned on.

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

SID (string): Constant containing the session name and session ID in the form of "name=ID".

Examples

Note: As of PHP 4.1.0, $_SESSION is available as global variable just like $_POST, $_GET, $_REQUEST and so on. Unlike $HTTP_SESSION_VARS, $_SESSION is always global. Therefore, you do not need to use the global keyword for $_SESSION. Please note that this documentation has been changed to use $_SESSION everywhere. You can substitute $HTTP_SESSION_VARS for $_SESSION, if you prefer the former.
The keys in the $_SESSION associative array are subject to the same limitations as regular variable names in PHP, i.e. they cannot start with a number and must start with a letter or underscore. For more details see the section on variables in this manual.

If register_globals is disabled, only members of the global associative array $_SESSION can be registered as session variables. The restored session variables will only be available in the array $_SESSION.

Use of $_SESSION (or $HTTP_SESSION_VARS with PHP 4.0.6 or less) is recommended for improved security and code readablity. With $_SESSION, there is no need to use the session_register(), session_unregister(), session_is_registered() functions. Session variables are accessible like any other variables.
Example 1. Registering a variable with $_SESSION.
<?php session_start(); // Use $HTTP_SESSION_VARS with PHP 4.0.6 or less if (!isset($_SESSION['count'])) { $_SESSION['count'] = 0; } else { $_SESSION['count']++; } ?>

Example 2. Unregistering a variable with $_SESSION and register_globals disabled.
<?php session_start(); // Use $HTTP_SESSION_VARS with PHP 4.0.6 or less unset($_SESSION['count']); ?>

Example 3. Unregistering a variable with register_globals enabled, after registering it using $_SESSION.
<?php session_start(); // With PHP 4.3 and later, you can also simply use the prior example. session_unregister('count'); ?>

If register_globals is enabled, then each global variable can be registered as session variable. Upon a restart of a session, these variables will be restored to corresponding global variables. Since PHP must know which global variables are registered as session variables, users need to register variables with session_register() function. You can avoid this by simply setting entries in $_SESSION.

Caution

If you are using $_SESSION and disable register_globals, do not use session_register(), session_is_registered() and session_unregister(), if your scripts shall work in PHP 4.2 and earlier. You can use these functions in 4.3 and later.

If you enable register_globals, session_unregister() should be used since session variables are registered as global variables when session data is deserialized. Disabling register_globals is recommended for both security and performance reasons.

Example 4. Registering a variable with register_globals enabled

<?php
if (!session_is_registered('count')) {
    session_register("count");
    $count = 0;
}
else {
    $count++;
}
?>

If register_globals is enabled, then the global variables and the $_SESSION entries will automatically reference the same value for session variables which were registered in prior session instances.

Additionally, if you register a new session variable by using session_register(), the entry in the global scope and the $_SESSION entry will not reference the same value until the next session_start() (this applies to PHP 4.2 and before only). I.e. a modification to the global variable will not be reflected by the $_SESSION entry. This is unlikely to matter in practice and has been corrected in PHP 4.3.

Passing the Session ID

There are two methods to propagate a session id:

Cookies
URL parameter

The session module supports both methods. Cookies are optimal, but since they are not reliable (clients are not bound to accept them), we cannot rely on them. The second method embeds the session id directly into URLs.

PHP is capable of doing this transparently if compiled with --enable-trans-sid. This option is always enabled in PHP 4.2 and later. If you enable this option, relative URIs will be changed to contain the session id automatically. Alternatively, you can use the constant SID which is defined, if the client did not send the appropriate cookie. SID is either of the form session_name=session_id or is an empty string.

Note: The arg_separator.output php.ini directive allows to customize the argument seperator.

The following example demonstrates how to register a variable, and how to link correctly to another page using SID.
Example 5. Counting the number of hits of a single user
<?php if (!session_is_registered('count')) { session_register('count'); $count = 1; } else { $count++; } ?> Hello visitor, you have seen this page <?php echo $count; ?> times.<p> To continue, <A HREF="nextpage.php?<?php echo SID?>">click here</A>

The <?php echo SID?> (<?=SID?> can be used if short_open_tag is enabled) is necessary to preserve the session id in the case that the user has disabled cookies. The <?=SID?> is not necessary, if --enable-trans-sid was used to compile PHP.

Note: Non-relative URLs are assumed to point to external sites and hence don't append the SID, as it would be a security risk to leak the SID to a different server.

Custom Session Handlers

To implement database storage, or any other storage method, you will need to use session_set_save_handler() to create a set of user-level storage functions.

Table of Contents
session_cache_expire -- Return current cache expire
session_cache_limiter -- Get and/or set the current cache limiter
session_decode -- Decodes session data from a string
session_destroy -- Destroys all data registered to a session
session_encode -- Encodes the current session data as a string
session_get_cookie_params -- Get the session cookie parameters
session_id -- Get and/or set the current session id
session_is_registered -- Find out if a variable is registered in a session
session_module_name -- Get and/or set the current session module
session_name -- Get and/or set the current session name
session_readonly -- Begin session - reinitializes frozen variables, but no writeback on request end
session_register -- Register one or more variables with the current session
session_save_path -- Get and/or set the current session save path
session_set_cookie_params -- Set the session cookie parameters
session_set_save_handler -- Sets user-level session storage functions
session_start -- Initialize session data
session_unregister -- Unregister a variable from the current session
session_unset -- Free all session variables
session_write_close -- Write session data and end session

session_cache_expire

(PHP 4 >= 4.2.0)

session_cache_expire -- Return current cache expire

Description

int session_cache_expire ( [int new_cache_expire])

session_cache_expire() returns current cache expire. If new_cache_expire is given, the current cache expire is replaced with new_cache_expire.

session_cache_limiter

(PHP 4 >= 4.0.3)

session_cache_limiter -- Get and/or set the current cache limiter

Description

string session_cache_limiter ( [string cache_limiter])

session_cache_limiter() returns the name of the current cache limiter. If cache_limiter is specified, the name of the current cache limiter is changed to the new value.

The cache limiter controls the cache control HTTP headers sent to the client. These headers determine the rules by which the page content may be cached. Setting the cache limiter to nocache, for example, would disallow any client-side caching. A value of public, however, would permit caching. It can also be set to private, which is slightly more restrictive than public.

In private mode, the Expire header sent to the client may cause confusion for some browsers, including Mozilla. You can avoid this problem by using private_no_expire mode. The expire header is never sent to the client in this mode.

Note: private_no_expire was added in PHP 4.2.0dev.

The cache limiter is reset to the default value stored in session.cache_limiter at request startup time. Thus, you need to call session_cache_limiter() for every request (and before session_start() is called).

Example 1. session_cache_limiter() examples

<?php

# set the cache limiter to 'private'

session_cache_limiter('private');
$cache_limiter = session_cache_limiter();

echo "The cache limiter is now set to $cache_limiter<p>";
?>

Description

array session_get_cookie_params ( void)

The session_get_cookie_params() function returns an array with the current session cookie information, the array contains the following items:

"lifetime" - The lifetime of the cookie.
"path" - The path where information is stored.
"domain" - The domain of the cookie.
"secure" - The cookie should only be sent over secure connections. (This item was added in PHP 4.0.4.)

session_id

(PHP 4 )

session_id -- Get and/or set the current session id

Description

string session_id ( [string id])

session_id() returns the session id for the current session.

If id is specified, it will replace the current session id. session_id() needs to be called before session_start() for that purpose. Depending on the session handler, not all characters are allowed within the session id. For example, the file session handler only allows characters in the range a-z, A-Z and 0-9!

The constant SID can also be used to retrieve the current name and session id as a string suitable for adding to URLs. Note that SID is only defined if the client didn't sent the right cookie. See also Session handling.

session_is_registered

(PHP 4 )

session_is_registered -- Find out if a variable is registered in a session

Description

bool session_is_registered ( string name)

session_is_registered() returns TRUE if there is a variable with the name name registered in the current session.

Note: If $_SESSION (or $HTTP_SESSION_VARS for PHP 4.0.6 or less) is used, use isset() to check a variable is registered in $_SESSION.

Caution

If you are using $_SESSION (or $HTTP_SESSION_VARS), do not use session_register(), session_is_registered() and session_unregister().

session_module_name

(PHP 4 )

session_module_name -- Get and/or set the current session module

Description

string session_module_name ( [string module])

session_module_name() returns the name of the current session module. If module is specified, that module will be used instead.

session_name

(PHP 4 )

session_name -- Get and/or set the current session name

Description

string session_name ( [string name])

session_name() returns the name of the current session. If name is specified, the name of the current session is changed to its value.

The session name references the session id in cookies and URLs. It should contain only alphanumeric characters; it should be short and descriptive (i.e. for users with enabled cookie warnings). The session name is reset to the default value stored in session.name at request startup time. Thus, you need to call session_name() for every request (and before session_start() or session_register() are called).

Example 1. session_name() examples

<?php

// set the session name to WebsiteID

$previous_name = session_name("WebsiteID");

echo "The previous session name was $previous_name<p>";
?>

session_readonly

(no version information, might be only in CVS)

session_readonly -- Begin session - reinitializes frozen variables, but no writeback on request end

Description

void session_readonly ( void)

Read in session data without locking the session data. Changing session data is not possible, but frameset performance will be improved.

session_register

(PHP 4 )

session_register -- Register one or more variables with the current session

Description

bool session_register ( mixed name [, mixed ...])

session_register() accepts a variable number of arguments, any of which can be either a string holding the name of a variable or an array consisting of variable names or other arrays. For each name, session_register() registers the global variable with that name in the current session.

Caution

This registers a global variable. If you want to register a session variable from within a function, you need to make sure to make it global using the global keyword or the $GLOBALS[] array, or use the special session arrays as noted below.

Caution

If you are using $_SESSION (or $HTTP_SESSION_VARS), do not use session_register(), session_is_registered() and session_unregister().

This function returns TRUE when all of the variables are successfully registered with the session.

If session_start() was not called before this function is called, an implicit call to session_start() with no parameters will be made.

You can also create a session variable by simply setting the appropriate member of the $_SESSION or $HTTP_SESSION_VARS (PHP < 4.1.0) array.

$barney = "A big purple dinosaur.";
session_register("barney");

$_SESSION["zim"] = "An invader from another planet.";

# The old way was to use $HTTP_SESSION_VARS
$HTTP_SESSION_VARS["spongebob"] = "He's got square pants.";

Note: It is not currently possible to register resource variables in a session. For example, you can not create a connection to a database and store the connection id as a session variable and expect the connection to still be valid the next time the session is restored. PHP functions that return a resource are identified by having a return type of resource in their function definitions. A list of functions that return resources are available in the resource types appendix.
If $_SESSION (or $HTTP_SESSION_VARS for PHP 4.0.6 or less) is used, assign variable to $_SESSION. i.e. $_SESSION['var'] = 'ABC';

session_save_path

(PHP 4 )

session_save_path -- Get and/or set the current session save path

Description

string session_save_path ( [string path])

session_save_path() returns the path of the current directory used to save session data. If path is specified, the path to which data is saved will be changed.

Note: On some operating systems, you may want to specify a path on a filesystem that handles lots of small files efficiently. For example, on Linux, reiserfs may provide better performance than ext2fs.

session_set_cookie_params

(PHP 4 )

session_set_cookie_params -- Set the session cookie parameters

Description

void session_set_cookie_params ( int lifetime [, string path [, string domain [, bool secure]]])

Set cookie parameters defined in the php.ini file. The effect of this function only lasts for the duration of the script.

Note: The secure parameter was added in PHP 4.0.4.

session_set_save_handler

(PHP 4 )

session_set_save_handler -- Sets user-level session storage functions

Description

bool session_set_save_handler ( string open, string close, string read, string write, string destroy, string gc)

session_set_save_handler() sets the user-level session storage functions which are used for storing and retrieving data associated with a session. This is most useful when a storage method other than those supplied by PHP sessions is preferred. i.e. Storing the session data in a local database. Returns TRUE on success or FALSE on failure.

Note: The "write" handler is not executed until after the output stream is closed. Thus, output from debugging statements in the "write" handler will never be seen in the browser. If debugging output is necessary, it is suggested that the debug output be written to a file instead.

Note: The write handler is not executed if the session contains no data; this applies even if empty session variables are registered. This differs to the default file-based session save handler, which creates empty session files.

The following example provides file based session storage similar to the PHP sessions default save handler files. This example could easily be extended to cover database storage using your favorite PHP supported database engine.

Read function must return string value always to make save handler work as expected. Return empty string if there is no data to read. Return values from other handlers are converted to boolean expression. TRUE for success, FALSE for failure.

Example 1. session_set_save_handler() example
<?php function open ($save_path, $session_name) { global $sess_save_path, $sess_session_name; $sess_save_path = $save_path; $sess_session_name = $session_name; return(true); } function close() { return(true); } function read ($id) { global $sess_save_path, $sess_session_name; $sess_file = "$sess_save_path/sess_$id"; if ($fp = @fopen($sess_file, "r")) { $sess_data = fread($fp, filesize($sess_file)); return($sess_data); } else { return(""); // Must return "" here. } } function write ($id, $sess_data) { global $sess_save_path, $sess_session_name; $sess_file = "$sess_save_path/sess_$id"; if ($fp = @fopen($sess_file, "w")) { return(fwrite($fp, $sess_data)); } else { return(false); } } function destroy ($id) { global $sess_save_path, $sess_session_name; $sess_file = "$sess_save_path/sess_$id"; return(@unlink($sess_file)); } /********************************************* * WARNING - You will need to implement some * * sort of garbage collection routine here. * *********************************************/ function gc ($maxlifetime) { return true; } session_set_save_handler ("open", "close", "read", "write", "destroy", "gc"); session_start(); // proceed to use sessions normally ?>

session_start

(PHP 4 )

session_start -- Initialize session data

Description

bool session_start ( void)

session_start() creates a session (or resumes the current one based on the session id being passed via a GET variable or a cookie).

If you want to use a named session, you must call session_name() before calling session_start().

This function always returns TRUE.

Note: If you are using cookie-based sessions, you must call session_start() before anything is output to the browser.

session_start() will register internal output handler for URL rewriting when trans-sid is enabled. If a user uses ob_gzhandler or like with ob_start(), the order of output handler is important for proper output. For example, user must register ob_gzhandler before session start.

Note: Use of zlib.output_compression is recommended rather than ob_gzhandler()

session_unregister

(PHP 4 )

session_unregister -- Unregister a variable from the current session

Description

bool session_unregister ( string name)

session_unregister() unregisters (forgets) the global variable named name from the current session.

This function returns TRUE when the variable is successfully unregistered from the session.

Note: If $_SESSION (or $HTTP_SESSION_VARS for PHP 4.0.6 or less) is used, use unset() to unregister a session variable.

Caution

This function doesn't unset the corresponding global variable for name, it only prevents the variable from being saved as part of the session. You must call unset() to remove the corresponding global variable.

Caution

If you are using $_SESSION (or $HTTP_SESSION_VARS), do not use session_register(), session_is_registered() and session_unregister().

session_unset

(PHP 4 )

session_unset -- Free all session variables

Description

void session_unset ( void)

The session_unset() function frees all session variables currently registered.

Note: If $_SESSION (or $HTTP_SESSION_VARS for PHP 4.0.6 or less) is used, use unset() to unregister session variable. i.e. $_SESSION = array();

session_write_close

(PHP 4 >= 4.0.4)

session_write_close -- Write session data and end session

Description

void session_write_close ( void)

End the current session and store session data.

Session data is usually stored after your script terminated without the need to call session_write_close(), but as session data is locked to prevent concurrent writes only one script may operate on a session at any time. When using framesets together with sessions you will experience the frames loading one by one due to this locking. You can reduce the time needed to load all the frames by ending the session as soon as all changes to session variables are done.

XCIV. Shared Memory Functions

Introduction

Shmop is an easy to use set of functions that allows PHP to read, write, create and delete UNIX shared memory segments. These functions will not typically work on Windows, as it does not support shared memory. As of Windows 2000 though, enabling the php_shmop.dll in your php.ini will enable this functionality though.

Note: In PHP 4.0.3, these functions were prefixed by shm rather than shmop.

Requirements

No external libraries are needed to build this extension.

Installation

To use shmop you will need to compile php with the --enable-shmop parameter in your configure line.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

Predefined Constants

This extension has no constants defined.

Examples

Example 1. Shared Memory Operations Overview
<?php // Create 100 byte shared memory block with system id if 0xff3 $shm_id = shmop_open(0xff3, "c", 0644, 100); if(!$shm_id) { echo "Couldn't create shared memory segment\n"; } // Get shared memory block's size $shm_size = shmop_size($shm_id); echo "SHM Block Size: ".$shm_size. " has been created.\n"; // Lets write a test string into shared memory $shm_bytes_written = shmop_write($shm_id, "my shared memory block", 0); if($shm_bytes_written != strlen("my shared memory block")) { echo "Couldn't write the entire length of data\n"; } // Now lets read the string back $my_string = shmop_read($shm_id, 0, $shm_size); if(!$my_string) { echo "Couldn't read from shared memory block\n"; } echo "The data inside shared memory was: ".$my_string."\n"; //Now lets delete the block and close the shared memory segment if(!shmop_delete($shm_id)) { echo "Couldn't mark shared memory block for deletion."; } shmop_close($shm_id); ?>

Table of Contents
shmop_close -- Close shared memory block
shmop_delete -- Delete shared memory block
shmop_open -- Create or open shared memory block
shmop_read -- Read data from shared memory block
shmop_size -- Get size of shared memory block
shmop_write -- Write data into shared memory block

Note: Note: the 3rd and 4th should be entered as 0 if you are opening an existing memory segment. On success shmop_open() will return an id that you can use to access the shared memory segment you've created.

Example 1. Writing to shared memory block
<?php $shm_bytes_written = shmop_write($shm_id, $my_string, 0); ?>

This example will write data inside $my_string into shared memory block, $shm_bytes_written will contain the number of bytes written.

XCV. Shockwave Flash functions

Introduction

PHP offers the ability to create Shockwave Flash files via Paul Haeberli's libswf module.

Note: SWF support was added in PHP 4 RC2.
The libswf does not have support for Windows. The development of that library has been stopped, and the source is not available to port it to another systems.
For up to date SWF support take a look at the MING functions.

Requirements

You need the libswf library to compile PHP with support for this extension. You can download libswf at ftp://ftp.sgi.com/sgi/graphics/grafica/flash.

Installation

Once you have libswf all you need to do is to configure --with-swf[=DIR] where DIR is a location containing the directories include and lib. The include directory has to contain the swf.h file and the lib directory has to contain the libswf.a file. If you unpack the libswf distribution the two files will be in one directory. Consequently you will have to copy the files to the proper location manually.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

MOD_COLOR (integer)
MOD_MATRIX (integer)
TYPE_PUSHBUTTON (integer)
TYPE_MENUBUTTON (integer)
BSHitTest (float)
BSDown (float)
BSOver (float)
BSUp (float)
OverDowntoIdle (integer)
IdletoOverDown (integer)
OutDowntoIdle (integer)
OutDowntoOverDown (integer)
OverDowntoOutDown (integer)
OverUptoOverDown (integer)
OverUptoIdle (integer)
IdletoOverUp (integer)
ButtonEnter (integer)
ButtonExit (integer)
MenuEnter (integer)
MenuExit (integer)

Examples

Once you've successfully installed PHP with Shockwave Flash support you can then go about creating Shockwave files from PHP. You would be surprised at what you can do, take the following code:
Example 1. SWF example
<?php swf_openfile ("test.swf", 256, 256, 30, 1, 1, 1); swf_ortho2 (-100, 100, -100, 100); swf_defineline (1, -70, 0, 70, 0, .2); swf_definerect (4, 60, -10, 70, 0, 0); swf_definerect (5, -60, 0, -70, 10, 0); swf_addcolor (0, 0, 0, 0); swf_definefont (10, "Mod"); swf_fontsize (5); swf_fontslant (10); swf_definetext (11, "This be Flash wit PHP!", 1); swf_pushmatrix (); swf_translate (-50, 80, 0); swf_placeobject (11, 60); swf_popmatrix (); for ($i = 0; $i < 30; $i++) { $p = $i/(30-1); swf_pushmatrix (); swf_scale (1-($p*.9), 1, 1); swf_rotate (60*$p, 'z'); swf_translate (20+20*$p, $p/1.5, 0); swf_rotate (270*$p, 'z'); swf_addcolor ($p, 0, $p/1.2, -$p); swf_placeobject (1, 50); swf_placeobject (4, 50); swf_placeobject (5, 50); swf_popmatrix (); swf_showframe (); } for ($i = 0; $i < 30; $i++) { swf_removeobject (50); if (($i%4) == 0) { swf_showframe (); } } swf_startdoaction (); swf_actionstop (); swf_enddoaction (); swf_closefile (); ?>

Table of Contents
swf_actiongeturl -- Get a URL from a Shockwave Flash movie
swf_actiongotoframe -- Play a frame and then stop
swf_actiongotolabel -- Display a frame with the specified label
swf_actionnextframe -- Go foward one frame
swf_actionplay -- Start playing the flash movie from the current frame
swf_actionprevframe -- Go backwards one frame
swf_actionsettarget -- Set the context for actions
swf_actionstop -- Stop playing the flash movie at the current frame
swf_actiontogglequality -- Toggle between low and high quality
swf_actionwaitforframe -- Skip actions if a frame has not been loaded
swf_addbuttonrecord -- Controls location, appearance and active area of the current button
swf_addcolor -- Set the global add color to the rgba value specified
swf_closefile -- Close the current Shockwave Flash file
swf_definebitmap -- Define a bitmap
swf_definefont -- Defines a font
swf_defineline -- Define a line
swf_definepoly -- Define a polygon
swf_definerect -- Define a rectangle
swf_definetext -- Define a text string
swf_endbutton -- End the definition of the current button
swf_enddoaction -- End the current action
swf_endshape -- Completes the definition of the current shape
swf_endsymbol -- End the definition of a symbol
swf_fontsize -- Change the font size
swf_fontslant -- Set the font slant
swf_fonttracking -- Set the current font tracking
swf_getbitmapinfo -- Get information about a bitmap
swf_getfontinfo -- The height in pixels of a capital A and a lowercase x
swf_getframe -- Get the frame number of the current frame
swf_labelframe -- Label the current frame
swf_lookat -- Define a viewing transformation
swf_modifyobject -- Modify an object
swf_mulcolor -- Sets the global multiply color to the rgba value specified
swf_nextid -- Returns the next free object id
swf_oncondition -- Describe a transition used to trigger an action list
swf_openfile -- Open a new Shockwave Flash file
swf_ortho2 -- Defines 2D orthographic mapping of user coordinates onto the current viewport
swf_ortho -- Defines an orthographic mapping of user coordinates onto the current viewport
swf_perspective -- Define a perspective projection transformation
swf_placeobject -- Place an object onto the screen
swf_polarview -- Define the viewer's position with polar coordinates
swf_popmatrix -- Restore a previous transformation matrix
swf_posround -- Enables or Disables the rounding of the translation when objects are placed or moved
swf_pushmatrix -- Push the current transformation matrix back unto the stack
swf_removeobject -- Remove an object
swf_rotate -- Rotate the current transformation
swf_scale -- Scale the current transformation
swf_setfont -- Change the current font
swf_setframe -- Switch to a specified frame
swf_shapearc -- Draw a circular arc
swf_shapecurveto3 -- Draw a cubic bezier curve
swf_shapecurveto -- Draw a quadratic bezier curve between two points
swf_shapefillbitmapclip -- Set current fill mode to clipped bitmap
swf_shapefillbitmaptile -- Set current fill mode to tiled bitmap
swf_shapefilloff -- Turns off filling
swf_shapefillsolid -- Set the current fill style to the specified color
swf_shapelinesolid -- Set the current line style
swf_shapelineto -- Draw a line
swf_shapemoveto -- Move the current position
swf_showframe -- Display the current frame
swf_startbutton -- Start the definition of a button
swf_startdoaction -- Start a description of an action list for the current frame
swf_startshape -- Start a complex shape
swf_startsymbol -- Define a symbol
swf_textwidth -- Get the width of a string
swf_translate -- Translate the current transformations
swf_viewport -- Select an area for future drawing

swf_closefile

(PHP 4 )

swf_closefile -- Close the current Shockwave Flash file

Description

array swf_getbitmapinfo ( int bitmapid)

The swf_getbitmapinfo() function returns an array of information about a bitmap given by the bitmapid parameter. The returned array has the following elements:

"size" - The size in bytes of the bitmap.
"width" - The width in pixels of the bitmap.
"height" - The height in pixels of the bitmap.

swf_getfontinfo

(PHP 4 )

swf_getfontinfo -- The height in pixels of a capital A and a lowercase x

Description

array swf_getfontinfo ( void)

The swf_getfontinfo() function returns an associative array with the following parameters:

Aheight - The height in pixels of a capital A.
xheight - The height in pixels of a lowercase x.

MOD_COLOR uses the current mulcolor (specified by the function swf_mulcolor()) and addcolor (specified by the function swf_addcolor()) to color the object. MOD_MATRIX uses the current matrix to position the object.

swf_mulcolor

(PHP 4 )

swf_mulcolor -- Sets the global multiply color to the rgba value specified

Description

void swf_mulcolor ( float r, float g, float b, float a)

The swf_mulcolor() function sets the global multiply color to the rgba color specified. This color is then used (implicitly) by the swf_placeobject(), swf_modifyobject() and the swf_addbuttonrecord() functions. The color of the object will be multiplied by the rgba values when the object is written to the screen.

Note: The rgba values can be either positive or negative.

swf_nextid

void swf_openfile ( string filename, float width, float height, float framerate, float r, float g, float b)

void swf_perspective ( float fovy, float aspect, float near, float far)

The swf_perspective() function defines a perspective projection transformation. The fovy parameter is field-of-view angle in the y direction. The aspect parameter should be set to the aspect ratio of the viewport that is being drawn onto. The near parameter is the near clipping plane and the far parameter is the far clipping plane.

Note: Various distortion artifacts may appear when performing a perspective projection, this is because Flash players only have a two dimensional matrix. Some are not to pretty.

swf_placeobject

(PHP 4 )

swf_placeobject -- Place an object onto the screen

Description

void swf_placeobject ( int objid, int depth)

Places the object specified by objid in the current frame at a depth of depth. The objid parameter and the depth must be between 1 and 65535.

This uses the current mulcolor (specified by swf_mulcolor()) and the current addcolor (specified by swf_addcolor()) to color the object and it uses the current matrix to position the object.

Note: Full RGBA colors are supported.

XCVI. SNMP functions

Introduction

Requirements

In order to use the SNMP functions on Unix you need to install the UCD SNMP package. On Windows these functions are only available on NT and not on Win95/98.

Installation

Important: In order to use the UCD SNMP package, you need to define NO_ZEROLENGTH_COMMUNITY to 1 before compiling it. After configuring UCD SNMP, edit config.h and search for NO_ZEROLENGTH_COMMUNITY. Uncomment the #define line. It should look like this afterwards:
#define NO_ZEROLENGTH_COMMUNITY 1
Now compile PHP --with-snmp[=DIR].

If you see strange segmentation faults in combination with SNMP commands, you did not follow the above instructions. If you do not want to recompile UCD SNMP, you can compile PHP with the --enable-ucd-snmp-hack switch which will work around the misfeature.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

Predefined Constants

This extension has no constants defined.

Table of Contents
snmp_get_quick_print -- Fetch the current value of the UCD library's quick_print setting
snmp_set_quick_print -- Set the value of quick_print within the UCD SNMP library
snmpget -- Fetch an SNMP object
snmprealwalk -- Return all objects including their respective object ID within the specified one
snmpset -- Set an SNMP object
snmpwalk -- Fetch all the SNMP objects from an agent
snmpwalkoid -- Query for a tree of information about a network entity

snmp_get_quick_print

(PHP 3>= 3.0.8, PHP 4 )

snmp_get_quick_print -- Fetch the current value of the UCD library's quick_print setting

Description

bool snmp_get_quick_print ( void)

Returns the current value stored in the UCD Library for quick_print. quick_print is off by default.

$quickprint = snmp_get_quick_print();

Above function call would return FALSE if quick_print is off, and TRUE if quick_print is on.

snmp_get_quick_print() is only available when using the UCD SNMP library. This function is not available when using the Windows SNMP library.

See: snmp_set_quick_print() for a full description of what quick_print does.

snmp_set_quick_print

(PHP 3>= 3.0.8, PHP 4 )

snmp_set_quick_print -- Set the value of quick_print within the UCD SNMP library

Description

void snmp_set_quick_print ( bool quick_print)

Sets the value of quick_print within the UCD SNMP library. When this is set (1), the SNMP library will return 'quick printed' values. This means that just the value will be printed. When quick_print is not enabled (default) the UCD SNMP library prints extra information including the type of the value (i.e. IpAddress or OID). Additionally, if quick_print is not enabled, the library prints additional hex values for all strings of three characters or less.

Setting quick_print is often used when using the information returned rather then displaying it.

snmp_set_quick_print(0);
$a = snmpget("127.0.0.1", "public", ".1.3.6.1.2.1.2.2.1.9.1");
echo "$a<BR>\n";
snmp_set_quick_print(1);
$a = snmpget("127.0.0.1", "public", ".1.3.6.1.2.1.2.2.1.9.1");
echo "$a<BR>\n";

The first value printed might be: 'Timeticks: (0) 0:00:00.00', whereas with quick_print enabled, just '0:00:00.00' would be printed.

By default the UCD SNMP library returns verbose values, quick_print is used to return only the value.

Currently strings are still returned with extra quotes, this will be corrected in a later release.

snmp_set_quick_print() is only available when using the UCD SNMP library. This function is not available when using the Windows SNMP library.

snmpget

(PHP 3, PHP 4 )

snmpget -- Fetch an SNMP object

Description

string snmpget ( string hostname, string community, string object_id [, int timeout [, int retries]])

Returns SNMP object value on success and FALSE on error.

The snmpget() function is used to read the value of an SNMP object specified by the object_id. SNMP agent is specified by the hostname and the read community is specified by the community parameter.

$syscontact = snmpget("127.0.0.1", "public", "system.SysContact.0");

$a = snmpwalk("127.0.0.1", "public", "");

Above function call would return all the SNMP objects from the SNMP agent running on localhost. One can step through the values with a loop

for ($i=0; $i < count($a); $i++) {
    echo $a[$i];
}

snmpwalkoid

(PHP 3>= 3.0.8, PHP 4 )

snmpwalkoid -- Query for a tree of information about a network entity

Description

array snmpwalkoid ( string hostname, string community, string object_id [, int timeout [, int retries]])

Returns an associative array with object ids and their respective object value starting from the object_id as root and FALSE on error.

snmpwalkoid() function is used to read all object ids and their respective values from an SNMP agent specified by the hostname. Community specifies the read community for that agent. A NULL object_id is taken as the root of the SNMP objects tree and all objects under that tree are returned as an array. If object_id is specified, all the SNMP objects below that object_id are returned.

The existence of snmpwalkoid() and snmpwalk() has historical reasons. Both functions are provided for backward compatibility.

$a = snmpwalkoid("127.0.0.1", "public", "");

Above function call would return all the SNMP objects from the SNMP agent running on localhost. One can step through the values with a loop

for (reset($a); $i = key($a); next($a)) {
    echo "$i: $a[$i]<br>\n";
}

XCVII. Socket functions

Introduction

The socket extension implements a low-level interface to the socket communication functions based on the popular BSD sockets, providing the possibility to act as a socket server as well as a client.

For a more generic client-side socket interface, see fsockopen() and pfsockopen().

When using these functions, it is important to remember that while many of them have identical names to their C counterparts, they often have different declarations. Please be sure to read the descriptions to avoid confusion.

Those unfamiliar with socket programming can find a lot of useful material in the appropriate Unix man pages, and there is a great deal of tutorial information on socket programming in C on the web, much of which can be applied, with slight modifications, to socket programming in PHP. The UNIX Socket FAQ might be a good start.

Warning

Requirements

No external libraries are needed to build this extension.

Installation

The socket functions described here are part of an extension to PHP which must be enabled at compile time by giving the --enable-sockets option to configure.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

AF_UNIX (integer)
AF_INET (integer)
SOCK_STREAM (integer)
SOCK_DGRAM (integer)
SOCK_RAW (integer)
SOCK_SEQPACKET (integer)
SOCK_RDM (integer)
MSG_OOB (integer)
MSG_WAITALL (integer)
MSG_PEEK (integer)
MSG_DONTROUTE (integer)
SO_DEBUG (integer)
SO_REUSEADDR (integer)
SO_KEEPALIVE (integer)
SO_DONTROUTE (integer)
SO_LINGER (integer)
SO_BROADCAST (integer)
SO_OOBINLINE (integer)
SO_SNDBUF (integer)
SO_RCVBUF (integer)
SO_SNDLOWAT (integer)
SO_RCVLOWAT (integer)
SO_SNDTIMEO (integer)
SO_RCVTIMEO (integer)
SO_TYPE (integer)
SO_ERROR (integer)
SOL_SOCKET (integer)
PHP_NORMAL_READ (integer)
PHP_BINARY_READ (integer)
SOL_TCP (integer)
SOL_UDP (integer)

Socket Errors

The socket extension was written to provide a useable interface to the powerful BSD sockets. Care has been taken that the functions work equally well on Win32 and Unix implementations. Almost all of the sockets functions may fail under certain conditions and therefore emit an E_WARNING message describing the error. Sometimes this doesn't happen to the desire of the developer. For example the function socket_read() may suddenly emit an E_WARNING message because the connection broke unexpectedly. It's common to suppress the warning with the @-operator and catch the error code within the application with the socket_last_error() function. You may call the socket_strerror() function with this error code to retrieve a string describing the error. See their description for more information.

Note: The E_WARNING messages generated by the socket extension are in english though the retrieved error message will appear depending on the current locale (LC_MESSAGES):
Warning - socket_bind() unable to bind address [98]: Die Adresse wird bereits verwendet

Examples

Example 1. Socket example: Simple TCP/IP server
This example shows a simple talkback server. Change the address and port variables to suit your setup and execute. You may then connect to the server with a command similar to: telnet 192.168.1.53 10000 (where the address and port match your setup). Anything you type will then be output on the server side, and echoed back to you. To disconnect, enter 'quit'.
#!/usr/local/bin/php -q <?php error_reporting (E_ALL); /* Allow the script to hang around waiting for connections. */ set_time_limit (0); /* Turn on implicit output flushing so we see what we're getting * as it comes in. */ ob_implicit_flush (); $address = '192.168.1.53'; $port = 10000; if (($sock = socket_create (AF_INET, SOCK_STREAM, 0)) < 0) { echo "socket_create() failed: reason: " . socket_strerror ($sock) . "\n"; } if (($ret = socket_bind ($sock, $address, $port)) < 0) { echo "socket_bind() failed: reason: " . socket_strerror ($ret) . "\n"; } if (($ret = socket_listen ($sock, 5)) < 0) { echo "socket_listen() failed: reason: " . socket_strerror ($ret) . "\n"; } do { if (($msgsock = socket_accept($sock)) < 0) { echo "socket_accept() failed: reason: " . socket_strerror ($msgsock) . "\n"; break; } /* Send instructions. */ $msg = "\nWelcome to the PHP Test Server. \n" . "To quit, type 'quit'. To shut down the server type 'shutdown'.\n"; socket_write($msgsock, $msg, strlen($msg)); do { if (FALSE === ($buf = socket_read ($msgsock, 2048))) { echo "socket_read() failed: reason: " . socket_strerror ($ret) . "\n"; break 2; } if (!$buf = trim ($buf)) { continue; } if ($buf == 'quit') { break; } if ($buf == 'shutdown') { socket_close ($msgsock); break 2; } $talkback = "PHP: You said '$buf'.\n"; socket_write ($msgsock, $talkback, strlen ($talkback)); echo "$buf\n"; } while (true); socket_close ($msgsock); } while (true); socket_close ($sock); ?>

Example 2. Socket example: Simple TCP/IP client
This example shows a simple, one-shot HTTP client. It simply connects to a page, submits a HEAD request, echoes the reply, and exits.
<?php error_reporting (E_ALL); echo "<h2>TCP/IP Connection</h2>\n"; /* Get the port for the WWW service. */ $service_port = getservbyname ('www', 'tcp'); /* Get the IP address for the target host. */ $address = gethostbyname ('www.example.com'); /* Create a TCP/IP socket. */ $socket = socket_create (AF_INET, SOCK_STREAM, 0); if ($socket < 0) { echo "socket_create() failed: reason: " . socket_strerror ($socket) . "\n"; } else { echo "OK.\n"; } echo "Attempting to connect to '$address' on port '$service_port'..."; $result = socket_connect ($socket, $address, $service_port); if ($result < 0) { echo "socket_connect() failed.\nReason: ($result) " . socket_strerror($result) . "\n"; } else { echo "OK.\n"; } $in = "HEAD / HTTP/1.0\r\n\r\n"; $out = ''; echo "Sending HTTP HEAD request..."; socket_write ($socket, $in, strlen ($in)); echo "OK.\n"; echo "Reading response:\n\n"; while ($out = socket_read ($socket, 2048)) { echo $out; } echo "Closing socket..."; socket_close ($socket); echo "OK.\n\n"; ?>

Table of Contents
socket_accept -- Accepts a connection on a socket
socket_bind -- Binds a name to a socket
socket_clear_error -- Clears the error on the socket or the last error code
socket_close -- Closes a socket resource
socket_connect -- Initiates a connection on a socket
socket_create_listen -- Opens a socket on port to accept connections
socket_create_pair -- Creates a pair of indistinguishable sockets and stores them in fds.
socket_create -- Create a socket (endpoint for communication)
socket_get_option -- Gets socket options for the socket
socket_getpeername -- Queries the remote side of the given socket which may either result in host/port or in a UNIX filesystem path, dependent on its type.
socket_getsockname -- Queries the local side of the given socket which may either result in host/port or in a UNIX filesystem path, dependent on its type.
socket_iovec_add -- Adds a new vector to the scatter/gather array
socket_iovec_alloc -- ...]) Builds a 'struct iovec' for use with sendmsg, recvmsg, writev, and readv
socket_iovec_delete -- Deletes a vector from an array of vectors
socket_iovec_fetch -- Returns the data held in the iovec specified by iovec_id[iovec_position]
socket_iovec_free -- Frees the iovec specified by iovec_id
socket_iovec_set -- Sets the data held in iovec_id[iovec_position] to new_val
socket_last_error -- Returns the last error on the socket
socket_listen -- Listens for a connection on a socket
socket_read -- Reads a maximum of length bytes from a socket
socket_readv -- Reads from an fd, using the scatter-gather array defined by iovec_id
socket_recv -- Receives data from a connected socket
socket_recvfrom -- Receives data from a socket, connected or not
socket_recvmsg -- Used to receive messages on a socket, whether connection-oriented or not
socket_select -- Runs the select() system call on the given arrays of sockets with a timeout specified by tv_sec and tv_usec
socket_send -- Sends data to a connected socket
socket_sendmsg -- Sends a message to a socket, regardless of whether it is connection-oriented or not
socket_sendto -- Sends a message to a socket, whether it is connected or not
socket_set_nonblock -- Sets nonblocking mode for file descriptor fd
socket_set_option -- Sets socket options for the socket
socket_shutdown -- Shuts down a socket for receiving, sending, or both.
socket_strerror -- Return a string describing a socket error
socket_write -- Write to a socket
socket_writev -- Writes to a file descriptor, fd, using the scatter-gather array defined by iovec_id

socket_accept

(PHP 4 >= 4.1.0)

socket_accept -- Accepts a connection on a socket

Description

resource socket_accept ( resource socket)

Warning

After the socket socket has been created using socket_create(), bound to a name with socket_bind(), and told to listen for connections with socket_listen(), this function will accept incoming connections on that socket. Once a successful connection is made, a new socket resource is returned, which may be used for communication. If there are multiple connections queued on the socket, the first will be used. If there are no pending connections, socket_accept() will block until a connection becomes present. If socket has been made non-blocking using socket_set_blocking() or socket_set_nonblock(), FALSE will be returned.

The socket resource returned by socket_accept() may not be used to accept new connections. The original listening socket socket, however, remains open and may be reused.

Returns a new socket resource on success, or FALSE on error. The actual error code can be retrieved by calling socket_last_error(). This error code may be passed to socket_strerror() to get a textual explanation of the error.

socket_bind

(PHP 4 >= 4.1.0)

socket_bind -- Binds a name to a socket

Description

bool socket_bind ( resource socket, string address [, int port])

Warning

resource socket_create_listen ( int port [, int backlog])

Warning

This function is meant to ease the task of creating a new socket which only listens to accept new connections.

socket_create_listen() create a new socket resource of type AF_INET listening on all local interfaces on the given port waiting for new connections.

The backlog parameter defines the maximum length the queue of pending connections may grow to. SOMAXCONN may be passed as backlog parameter, see socket_listen() for more information.

socket_create_listen() returns a new socket resource on success or FALSE on error. The error code can be retrieved with socket_last_error(). This code may be passed to socket_strerror() to get a textual explanation of the error.

Note: If you want to create a socket which only listens on a certain interfaces you need to use socket_create(), socket_bind() and socket_listen().

socket_create_pair

(PHP 4 >= 4.1.0)

socket_create_pair -- Creates a pair of indistinguishable sockets and stores them in fds.

Description

bool socket_create_pair ( int domain, int type, int protocol, array &fd)

Warning

This function is currently not documented; only the argument list is available.

socket_create

(PHP 4 >= 4.1.0)

socket_create -- Create a socket (endpoint for communication)

Description

resource socket_create ( int domain, int type, int protocol)

Warning

Creates a communication endpoint (a socket), and returns a socket resource.

The domain parameter sets the domain (protocol family) to be used for communication. Currently, AF_INET and AF_UNIX are understood. AF_INET is typical used for internet based communication. AF_UNIX uses pathnames to identify sockets and can therefore only be used for local communication (which is faster, on the other hand).

The type parameter selects the socket type. This is one of SOCK_STREAM, SOCK_DGRAM, SOCK_SEQPACKET, SOCK_RAW, SOCK_RDM, or SOCK_PACKET. The two most common types are SOCK_DGRAM for UDP (connectionless) communication and SOCK_STREAM for TCP communication.

protocol sets the protocol which is either SOL_UDP or SOL_TCP.

Returns a socket resource on success, or FALSE on error. The actual error code can be retrieved by calling socket_last_error(). This error code may be passed to socket_strerror() to get a textual explanation of the error.

For more information on the usage of socket_create(), as well as on the meanings of the various parameters, see the Unix man page socket (2).

Note: If an invalid domain or type is given, socket_create() defaults to AF_INET and SOCK_STREAM respectively and additionally emits an E_WARNING message.

socket_get_option

(PHP 4 CVS only)

socket_get_option -- Gets socket options for the socket

Description

mixed socket_get_option ( resource socket, int level, int optname)

Warning

This function is currently not documented; only the argument list is available.

Note: This function used to be called socket_getopt() prior to PHP 4.3.0

socket_getpeername

(PHP 4 >= 4.1.0)

socket_getpeername -- Queries the remote side of the given socket which may either result in host/port or in a UNIX filesystem path, dependent on its type.

Description

bool socket_getpeername ( resource socket, string &addr [, int &port])

Warning

If the given socket is of type AF_INET, socket_getpeername() will return the peers (remote) IP address in dotted-quad notation (e.g. 127.0.0.1) in the address parameter and, if the optional port parameter is present, also the associated port.

If the given socket is of type AF_UNIX, socket_getpeername() will return the UNIX filesystem path (e.g. /var/run/daemon.sock) in the address parameter.

Returns TRUE on success or FALSE on failure. socket_getpeername() may also return FALSE if the socket type is not any of AF_INET or AF_UNIX, in which case the last socket error code is not updated.

See also socket_getpeername(), socket_last_error() and socket_strerror().

socket_getsockname

(PHP 4 >= 4.1.0)

socket_getsockname -- Queries the local side of the given socket which may either result in host/port or in a UNIX filesystem path, dependent on its type.

Description

bool socket_getsockname ( resource socket, string &addr [, int &port])

Warning

int socket_last_error ( [resource socket])

Warning

This function returns a socket error code.

If a socket resource is passed to this function, the last error which occured on this particular socket is returned. If the socket resource is ommited, the error code of the last failed socket function is returned. The latter is in particular helpful for functions like socket_create() which don't return a socket on failure and socket_select() which can fail for reasons not directly tied to a particular socket. The error code is suitable to be fed to socket_strerror() which returns a string describing the given error code.
if (false == ($socket = @socket_create(AF_INET, SOCK_STREAM, SOL_TCP))) { die("Couldn't create socket, error code is: " . socket_last_error() . ",error message is: " . socket_strerror(socket_last_error())); }

Note: socket_last_error() does not clear the error code, use socket_clear_error() for this purpose.

socket_listen

(PHP 4 >= 4.1.0)

socket_listen -- Listens for a connection on a socket

Description

bool socket_listen ( resource socket [, int backlog])

Warning

After the socket socket has been created using socket_create() and bound to a name with socket_bind(), it may be told to listen for incoming connections on socket.

A maximum of backlog incoming connections will be queued for processing. If a connection request arrives with the queue full the client may receive an error with an indication of ECONNREFUSED, or, if the underlying protocol supports retransmission, the request may be ignored so that retries may succeed.

Note: The maximum number passed to the backlog parameter highly depends on the underlying platform. On linux, it is silently truncated to SOMAXCONN. On win32, if passed SOMAXCONN, the underlying service provider responsible for the socket will set the backlog to a maximum reasonable value. There is no standard provision to find out the actual backlog value on this platform.

socket_listen() is applicable only to sockets of type SOCK_STREAM or SOCK_SEQPACKET.

socket_read

(PHP 4 >= 4.1.0)

socket_read -- Reads a maximum of length bytes from a socket

Description

string socket_read ( resource socket, int length [, int type])

Warning

The function socket_read() reads from the socket resource socket created by the socket_create() or socket_accept() functions. The maximum number of bytes read is specified by the length parameter. Otherwise you can use \r, \n, or \0 to end reading (depending on the type parameter, see below).

socket_read() returns the data as a string on success, or FALSE on error. The error code can be retrieved with socket_last_error(). This code may be passed to socket_strerror() to get a textual representation of the error.

Note: socket_read() may return a zero length string ("") indicating the end of communication (i.e. the remote end point has closed the connection).

Optional type parameter is a named constant:

PHP_BINARY_READ - use the system read() function. Safe for reading binary data. (Default in PHP >= 4.1.0)
PHP_NORMAL_READ - reading stops at \n or \r. (Default in PHP <= 4.0.6)

The sockets listed in the read array will be watched to see if characters become available for reading (more precisely, to see if a read will not block - in particular, a socket resource is also ready on end-of-file, in which case a socket_read() will return a zero length string).

The sockets listed in the write array will be watched to see if a write will not block.

The sockets listed in the except array will be watched for exceptions.

Warning

On exit, the arrays are modified to indicate which socket resource actually changed status.

You do not need to pass every array to socket_select(). You can leave it out and use an empty array or NULL instead. Also do not forget that those arrays are passed by reference and will be modified after socket_select() returns.

Example:
/* Prepare the read array */ $read = array($socket1, $socket2); if (false === ($num_changed_sockets = socket_select($read, $write = NULL, $except = NULL, 0))) { /* Error handling */ else if ($num_changed_sockets > 0) { /* At least at one of the sockets something interesting happened */ }

Note: Due a limitation in the current Zend Engine it is not possible to pass a constant modifier like NULL directly as a parameter to a function which expects this parameter to be passed by reference. Instead use a temporary variable or an expression with the leftmost member being a temporary variable:
socket_select($r, $w, $e = NULL, 0);

The tv_sec and tv_usec together form the timeout parameter. The timeout is an upper bound on the amount of time elapsed before socket_select() return. tv_sec may be zero , causing socket_select() to return immediately. This is useful for polling. If tv_sec is NULL (no timeout), socket_select() can block indefinitely.

On success socket_select() returns the number of socket resorces contained in the modified arrays, which may be zero if the timeout expires before anything interesting happens. On error FALSE is returned. The error code can be retrieved with socket_last_error().

Note: Be sure to use the === operator when checking for an error. Since the socket_select() may return 0 the comparison with == would evaluate to TRUE:
if (false === socket_select($r, $w, $e = NULL, 0)) {
    echo "socket_select() failed, reason: " . socket_strerror(socket_last_error()) . "\n";
}

Note: Be aware that some socket implementations need to be handled very carefully. A few basic rules:
You should always try to use socket_select() without timeout. Your program should have nothing to do if there is no data available. Code that depends on timeouts is not usually portable and difficult to debug.
No socket resource must be added to any set if you do not intend to check its result after the socket_select() call, and respond appropriately. After socket_select() returns, all socket resources in all arrays must be checked. Any socket resource that is available for writing must be written to, and any socket resource available for reading must be read from.
If you read/write to a socket returns in the arrays be aware that they do not necessarily read/write the full amount of data you have requested. Be prepared to even only be able to read/write a single byte.
It's common to most socket implementations that the only exception caught with the except array is out-of-bound data received on a socket.

Note: This function used to be called socket_setopt() prior to PHP 4.3.0

socket_shutdown

(PHP 4 >= 4.1.0)

socket_shutdown -- Shuts down a socket for receiving, sending, or both.

Description

bool socket_shutdown ( resource socket [, int how])

Warning

This function is currently not documented; only the argument list is available.

socket_strerror

(PHP 4 >= 4.1.0)

socket_strerror -- Return a string describing a socket error

Description

string socket_strerror ( int errno)

Warning

socket_strerror() takes as its errno parameter a socket error code as returned by socket_last_error() and returns the corresponding explanatory text. This makes it a bit more pleasant to figure out why something didn't work; for instance, instead of having to track down a system include file to find out what '-111' means, you just pass it to socket_strerror(), and it tells you what happened.

Example 1. socket_strerror() example
<?php if (false == ($socket = @socket_create(AF_INET, SOCK_STREAM, 0))) { echo "socket_create() failed: reason: " . socket_strerror(socket_last_error()) . "\n"; } if (false == (@socket_bind($socket, '127.0.0.1', 80))) { echo "socket_bind() failed: reason: " . socket_strerror(socket_last_error($socket)) . "\n"; } ?>
The expected output from the above example (assuming the script is not run with root privileges):
socket_bind() failed: reason: Permission denied

socket_write

(PHP 4 >= 4.1.0)

socket_write -- Write to a socket

Description

int socket_write ( resource socket, string buffer [, int length])

Warning

The function socket_write() writes to the socket socket from buffer.

The optional parameter length can specify an alternate length of bytes written to the socket. If this length is greater then the buffer length, it is silently truncated to the length of the buffer.

Returns the number of bytes successfully written to the socket or FALSE one error. The error code can be retrieved with socket_last_error(). This code may be passed to socket_strerror() to get a textual explanation of the error.

Note: socket_write() does not necessarily write all bytes from the given buffer. It's valid that, depending on the network buffers etc., only a certain amount of data, even one byte, is written though your buffer is greater. You have to watch out so you don't unintentionally forget to transmit the rest of your data.

Note: It is perfectly valid for socket_write() to return zero which means no bytes have been written. Be sure to use the === operator to check for FALSE in case of an error.

socket_writev

(PHP 4 >= 4.1.0)

socket_writev -- Writes to a file descriptor, fd, using the scatter-gather array defined by iovec_id

Description

bool socket_writev ( resource socket, resource iovec_id)

Warning

This function is currently not documented; only the argument list is available.

XCVIII. String functions

Introduction

These functions all manipulate strings in various ways. Some more specialized sections can be found in the regular expression and URL handling sections.

For information on how strings behave, especially with regard to usage of single quotes, double quotes, and escape sequences, see the Strings entry in the Types section of the manual.

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Predefined Constants

This extension has no constants defined.

addcslashes

(PHP 4 )

addcslashes -- Quote string with slashes in a C style

Description

string addcslashes ( string str, string charlist)

Returns a string with backslashes before characters that are listed in charlist parameter. It escapes \n, \r etc. in C-like style, characters with ASCII code lower than 32 and higher than 126 are converted to octal representation.

Be careful if you choose to escape characters 0, a, b, f, n, r, t and v. They will be converted to \0, \a, \b, \f, \n, \r, \t and \v. In PHP \0 (NULL), \r (carriage return), \n (newline) and \t (tab) are predefined escape sequences, while in C all of these are predefined escape sequences.

charlist like "\0..\37", which would escape all characters with ASCII code between 0 and 31.
Example 1. addcslashes() example
$escaped = addcslashes($not_escaped, "\0..\37!@\177..\377");

When you define a sequence of characters in the charlist argument make sure that you know what characters come between the characters that you set as the start and end of the range.

echo addcslashes('foo[ ]', 'A..z');
// output:  \f\o\o\[ \]
// All upper and lower-case letters will be escaped
// ... but so will the [\]^_` and any tabs, line
// feeds, carriage returns, etc.

Also, if the first character in a range has a lower ASCII value than the second character in the range, no range will be constructed. Only the start, end and period characters will be escaped. Use the ord() function to find the ASCII value for a character.

echo addcslashes("zoo['.']", 'z..A');
// output:  \zoo['\.']

addslashes

(PHP 3, PHP 4 )

addslashes -- Quote string with slashes

Description

string addslashes ( string str)

Returns a string with backslashes before characters that need to be quoted in database queries etc. These characters are single quote ('), double quote ("), backslash (\) and NUL (the NULL byte).

Note: magic_quotes_gpc is ON by default.

Generates the cyclic redundancy checksum polynomial of 32-bit lengths of the str. This is usually used to validate the integrity of data being transmitted.

crypt

(PHP 3, PHP 4 )

crypt -- One-way string encryption (hashing)

Description

string crypt ( string str [, string salt])

crypt() will return an encrypted string using the standard Unix DES-based encryption algorithm or alternative algorithms that may be available on the system. Arguments are a string to be encrypted and an optional salt string to base the encryption on. See the Unix man page for your crypt function for more information.

If the salt argument is not provided, one will be randomly generated by PHP.

Some operating systems support more than one type of encryption. In fact, sometimes the standard DES-based encryption is replaced by an MD5-based encryption algorithm. The encryption type is triggered by the salt argument. At install time, PHP determines the capabilities of the crypt function and will accept salts for other encryption types. If no salt is provided, PHP will auto-generate a standard two character salt by default, unless the default encryption type on the system is MD5, in which case a random MD5-compatible salt is generated. PHP sets a constant named CRYPT_SALT_LENGTH which tells you whether a regular two character salt applies to your system or the longer twelve character salt is applicable.

If you are using the supplied salt, you should be aware that the salt is generated once. If you are calling this function recursively, this may impact both appearance and security.

The standard DES-based encryption crypt() returns the salt as the first two characters of the output. It also only uses the first eight characters of str, so longer strings that start with the same eight characters will generate the same result (when the same salt is used).

On systems where the crypt() function supports multiple encryption types, the following constants are set to 0 or 1 depending on whether the given type is available:

CRYPT_STD_DES - Standard DES-based encryption with a two character salt
CRYPT_EXT_DES - Extended DES-based encryption with a nine character salt
CRYPT_MD5 - MD5 encryption with a twelve character salt starting with $1$
CRYPT_BLOWFISH - Blowfish encryption with a sixteen character salt starting with $2$

Note: There is no decrypt function, since crypt() uses a one-way algorithm.

Example 1. crypt() examples

<?php
$password = crypt("My1sTpassword"); # let salt be generated

# You should pass the entire results of crypt() as the salt for comparing a
# password, to avoid problems when different hashing algorithms are used. (As
# it says above, standard DES-based password hashing uses a 2-character salt,
# but MD5-based hashing uses 12.)
if (crypt($user_input,$password) == $password) {
   echo "Password verified!";
}
?>

See also md5() and the Mcrypt extension.

echo

(PHP 3, PHP 4 )

echo -- Output one or more strings

Description

echo ( string arg1 [, string argn...])

Outputs all parameters.

echo() is not actually a function (it is a language construct) so you are not required to use parentheses with it. In fact, if you want to pass more than one parameter to echo, you must not enclose the parameters within parentheses. It is not possible to use echo() in a variable function context, but you can use print() instead.
Example 1. echo() examples
<?php echo "Hello World"; echo "This spans multiple lines. The newlines will be output as well"; echo "This spans\nmultiple lines. The newlines will be\noutput as well."; echo "Escaping characters is done \"Like this\"."; //You can use variables inside of an echo statement $foo = "foobar"; $bar = "barbaz"; echo "foo is $foo"; // foo is foobar // Using single quotes will print the variable name, not the value echo 'foo is $foo'; // foo is $foo // If you are not using any other characters, you can just echo variables echo $foo; // foobar echo $foo,$bar; // foobarbarbaz echo <<<END This uses the "here document" syntax to output multiple lines with $variable interpolation. Note that the here document terminator must appear on a line with just a semicolon no extra whitespace! END; // Because echo is not a function, following code is invalid. ($some_var) ? echo('true'): echo('false'); // However, the following examples will work: ($some_var) ? print('true'): print('false'); // print is a function echo $some_var ? 'true': 'false'; // changing the statement around ?>

echo() also has a shortcut syntax, where you can immediately follow the opening tag with an equals sign.

I have <?=$foo?> foo.

Note: This short syntax only works with the short_open_tag configuration setting enabled.

See also print(), printf(), and flush().

explode

(PHP 3, PHP 4 )

explode -- Split a string by string

Description

array explode ( string separator, string string [, int limit])

Returns an array of strings, each of which is a substring of string formed by splitting it on boundaries formed by the string separator. If limit is set, the returned array will contain a maximum of limit elements with the last element containing the rest of string.

If separator is an empty string (""), explode() will return FALSE. If separator contains a value that is not contained in string, then explode() will return an array containing string.

Note: The limit parameter was added in PHP 4.0.1

Example 1. explode() examples
$pizza = "piece1 piece2 piece3 piece4 piece5 piece6"; $pieces = explode(" ", $pizza); $data = "foo:*:1023:1000::/home/foo:/bin/sh"; list($user,$pass,$uid,$gid,$gecos,$home,$shell) = explode(":",$data);

Note: Although implode() can for historical reasons accept its parameters in either order, explode() cannot. You must ensure that the separator argument comes before the string argument.

get_html_translation_table

(PHP 4 )

get_html_translation_table -- Returns the translation table used by htmlspecialchars() and htmlentities()

Description

string get_html_translation_table ( int table [, int quote_style])

get_html_translation_table() will return the translation table that is used internally for htmlspecialchars() and htmlentities(). There are two new defines (HTML_ENTITIES, HTML_SPECIALCHARS) that allow you to specify the table you want. And as in the htmlspecialchars() and htmlentities() functions you can optionally specify the quote_style you are working with. The default is ENT_COMPAT mode. See the description of these modes in htmlspecialchars().
Example 1. Translation Table Example
$trans = get_html_translation_table(HTML_ENTITIES); $str = "Hallo & <Frau> & Krämer"; $encoded = strtr($str, $trans);
The $encoded variable will now contain: "Hallo & <Frau> & Krämer".

The cool thing is using array_flip() to change the direction of the translation.

$trans = array_flip($trans);
$original = strtr($encoded, $trans);

The content of $original would be: "Hallo & <Frau> & Krämer".

get_meta_tags

(PHP 3>= 3.0.4, PHP 4 )

get_meta_tags -- Extracts all meta tag content attributes from a file and returns an array

Description

array get_meta_tags ( string filename [, int use_include_path])

Opens filename and parses it line by line for <meta> tags of the form
Example 1. Meta Tags Example
<meta name="author" content="name"> <meta name="tags" content="php3 documentation"> </head> 
(pay attention to line endings - PHP uses a native function to parse the input, so a Mac file won't work on Unix).

string htmlentities ( string string [, int quote_style [, string charset]])

This function is identical to htmlspecialchars() in all ways, except that all characters which have HTML character entity equivalents are translated into these entities. Like htmlspecialchars(), it takes an optional second argument which indicates what should be done with single and double quotes. ENT_COMPAT (the default) will only convert double-quotes and leave single-quotes alone. ENT_QUOTES will convert both double and single quotes, and ENT_NOQUOTES will leave both double and single quotes unconverted.

At present, the ISO-8859-1 character set is used as default. Support for the optional second argument was added in PHP 3.0.17 and PHP 4.0.3.

Like htmlspecialchars(), it takes an optional third argument which defines character set used in conversion. Support for this argument was added in PHP 4.1.0.

There is no reverse of this function. However, you can create one on your own. Here is an example of how to do this.

Example 1. Reverse of htmlentities()

<?php
function unhtmlentities ($string)
{
	$trans_tbl = get_html_translation_table (HTML_ENTITIES);
	$trans_tbl = array_flip ($trans_tbl);
	return strtr ($string, $trans_tbl);
}
?>

htmlspecialchars

(PHP 3, PHP 4 )

htmlspecialchars -- Convert special characters to HTML entities

Description

string htmlspecialchars ( string string [, int quote_style [, string charset]])

Certain characters have special significance in HTML, and should be represented by HTML entities if they are to preserve their meanings. This function returns a string with some of these conversions made; the translations made are those most useful for everyday web programming. If you require all HTML character entities to be translated, use htmlentities() instead.

This function is useful in preventing user-supplied text from containing HTML markup, such as in a message board or guest book application. The optional second argument, quote_style, tells the function what to do with single and double quote characters. The default mode, ENT_COMPAT, is the backwards compatible mode which only translates the double-quote character and leaves the single-quote untranslated. If ENT_QUOTES is set, both single and double quotes are translated and if ENT_NOQUOTES is set neither single nor double quotes are translated.

The translations performed are:

'&' (ampersand) becomes '&'
'"' (double quote) becomes '"' when ENT_NOQUOTES is not set.
''' (single quote) becomes ''' only when ENT_QUOTES is set.
'<' (less than) becomes '<'
'>' (greater than) becomes '>'

Example 1. htmlspecialchars() example

$new = htmlspecialchars("<a href='test'>Test</a>", ENT_QUOTES);

Note that this function does not translate anything beyond what is listed above. For full entity translation, see htmlentities(). Support for the optional second argument was added in PHP 3.0.17 and PHP 4.0.3.

The third argument defines character set used in conversion. The default character set is ISO-8859-1. Support for this third argument was added in PHP 4.1.0.

implode

(PHP 3, PHP 4 )

implode -- Join array elements with a string

Description

string implode ( string glue, array pieces)

Returns a string containing a string representation of all the array elements in the same order, with the glue string between each element.
Example 1. implode() example
<?php $array = array('lastname', 'email', 'phone'); $comma_separated = implode(",", $array); print $comma_separated; // lastname,email,phone ?>

Note: implode() can, for historical reasons, accept its parameters in either order. For consistency with explode(), however, it may be less confusing to use the documented order of arguments.

See also explode(), and split().

join

(PHP 3, PHP 4 )

join -- Join array elements with a string

Description

string join ( string glue, array pieces)

join() is an alias to implode(), and is identical in every way.

See also explode(), implode(), and split().

levenshtein

(PHP 3>= 3.0.17, PHP 4 >= 4.0.1)

levenshtein -- Calculate Levenshtein distance between two strings

Description

int levenshtein ( string str1, string str2)

int levenshtein ( string str1, string str2, int cost_ins, int cost_rep, int cost_del)

int levenshtein ( string str1, string str2, function cost)

This function returns the Levenshtein-Distance between the two argument strings or -1, if one of the argument strings is longer than the limit of 255 characters (255 should be more than enough for name or dictionary comparison, and nobody serious would be doing genetic analysis with PHP).

The Levenshtein distance is defined as the minimal number of characters you have to replace, insert or delete to transform str1 into str2. The complexity of the algorithm is O(m*n), where n and m are the length of str1 and str2 (rather good when compared to similar_text(), which is O(max(n,m)**3), but still expensive).

In its simplest form the function will take only the two strings as parameter and will calculate just the number of insert, replace and delete operations needed to transform str1 into str2.

A second variant will take three additional parameters that define the cost of insert, replace and delete operations. This is more general and adaptive than variant one, but not as efficient.

The third variant (which is not implemented yet) will be the most general and adaptive, but also the slowest alternative. It will call a user-supplied function that will determine the cost for every possible operation.

The user-supplied function will be called with the following arguments:

operation to apply: 'I', 'R' or 'D'
actual character in string 1
actual character in string 2
position in string 1
position in string 2
remaining characters in string 1
remaining characters in string 2

The user-supplied function has to return a positive integer describing the cost for this particular operation, but it may decide to use only some of the supplied arguments.

The user-supplied function approach offers the possibility to take into account the relevance of and/or difference between certain symbols (characters) or even the context those symbols appear in to determine the cost of insert, replace and delete operations, but at the cost of losing all optimizations done regarding cpu register utilization and cache misses that have been worked into the other two variants.

localeconv

(PHP 4 >= 4.0.5)

localeconv -- Get numeric formatting information

Description

array localeconv ( void)

Returns an associative array containing localized numeric and monetary formatting information.

localeconv() returns data based upon the current locale as set by setlocale(). The associative array that is returned contains the following fields:

Array element Description

decimal_point Decimal point character

thousands_sep Thousands separator

grouping Array containing numeric groupings

int_curr_symbol International currency symbol (i.e. USD)

currency_symbol Local currency symbol (i.e. $)

mon_decimal_point Monetary decimal point character

mon_thousands_sep Monetary thousands separator

mon_grouping Array containing monetary groupings

positive_sign Sign for positive values

negative_sign Sign for negative values

int_frac_digits International fractional digits

frac_digits Local fractional digits

p_cs_precedes TRUE if currency_symbol precedes a positive value, FALSE if it succeeds one

p_sep_by_space TRUE if a space separates currency_symbol from a positive value, FALSE otherwise

n_cs_precedes TRUE if currency_symbol precedes a negative value, FALSE if it succeeds one

n_sep_by_space TRUE if a space separates currency_symbol from a negative value, FALSE otherwise

p_sign_posn

0	Parentheses surround the quantity and currency_symbol
1	The sign string precedes the quantity and currency_symbol
2	The sign string succeeds the quantity and currency_symbol
3	The sign string immediately precedes the currency_symbol
4	The sign string immediately succeeds the currency_symbol

n_sign_posn

0	Parentheses surround the quantity and currency_symbol
1	The sign string precedes the quantity and currency_symbol
2	The sign string succeeds the quantity and currency_symbol
3	The sign string immediately precedes the currency_symbol
4	The sign string immediately succeeds the currency_symbol

The grouping fields contain arrays that define the way numbers should be grouped. For example, the grouping field for the en_US locale, would contain a 2 item array with the values 3 and 3. The higher the index in the array, the farther left the grouping is. If an array element is equal to CHAR_MAX, no further grouping is done. If an array element is equal to 0, the previous element should be used.

Example 1. localeconv() example

setlocale(LC_ALL, "en_US");

$locale_info = localeconv();

echo "<PRE>\n";
echo "--------------------------------------------\n";
echo "  Monetary information for current locale:  \n";
echo "--------------------------------------------\n\n";

echo "int_curr_symbol:   {$locale_info["int_curr_symbol"]}\n";
echo "currency_symbol:   {$locale_info["currency_symbol"]}\n";
echo "mon_decimal_point: {$locale_info["mon_decimal_point"]}\n";
echo "mon_thousands_sep: {$locale_info["mon_thousands_sep"]}\n";
echo "positive_sign:     {$locale_info["positive_sign"]}\n";
echo "negative_sign:     {$locale_info["negative_sign"]}\n";
echo "int_frac_digits:   {$locale_info["int_frac_digits"]}\n";
echo "frac_digits:       {$locale_info["frac_digits"]}\n";
echo "p_cs_precedes:     {$locale_info["p_cs_precedes"]}\n";
echo "p_sep_by_space:    {$locale_info["p_sep_by_space"]}\n";
echo "n_cs_precedes:     {$locale_info["n_cs_precedes"]}\n";
echo "n_sep_by_space:    {$locale_info["n_sep_by_space"]}\n";
echo "p_sign_posn:       {$locale_info["p_sign_posn"]}\n";
echo "n_sign_posn:       {$locale_info["n_sign_posn"]}\n";
echo "</PRE>\n";

The constant CHAR_MAX is also defined for the use mentioned above.

ltrim

(PHP 3, PHP 4 )

ltrim -- Strip whitespace from the beginning of a string

Description

string ltrim ( string str [, string charlist])

Note: The second parameter was added in PHP 4.1.0

This function returns a string with whitespace stripped from the beginning of str. Without the second parameter, ltrim() will strip these characters:

" " (ASCII 32 (0x20)), an ordinary space.
"\t" (ASCII 9 (0x09)), a tab.
"\n" (ASCII 10 (0x0A)), a new line (line feed).
"\r" (ASCII 13 (0x0D)), a carriage return.
"\0" (ASCII 0 (0x00)), the NUL-byte.
"\x0B" (ASCII 11 (0x0B)), a vertical tab.

You can also specify the characters you want to strip, by means of the charlist parameter. Simply list all characters that you want to be stripped. With .. you can specify a range of characters.

Example 1. Usage example of ltrim()

<?php $text = "\t\tThese are a few words :) ... "; $trimmed = ltrim($text); // $trimmed = "These are a few words :) ... " $trimmed = ltrim($text," \t."); // $trimmed = "These are a few words :) ... " $clean = ltrim($binary,"\0x00..\0x1F"); // trim the ASCII control characters at the beginning of $binary // (from 0 to 31 inclusive) ?>

md5_file

(PHP 4 >= 4.2.0)

md5_file -- Calculates the md5 hash of a given filename

Description

string md5_file ( string filename)

Calculates the MD5 hash of the specified filename using the RSA Data Security, Inc. MD5 Message-Digest Algorithm, and returns that hash.

This function has the same purpose of the command line utility md5sum.

md5

(PHP 3, PHP 4 )

md5 -- Calculate the md5 hash of a string

Description

string md5 ( string str)

Calculates the MD5 hash of str using the RSA Data Security, Inc. MD5 Message-Digest Algorithm, and returns that hash. The hash is a 32-character hexadecimal number.

metaphone

(PHP 4 )

metaphone -- Calculate the metaphone key of a string

Description

string metaphone ( string str)

string number_format ( float number [, int decimals [, string dec_point [, string thousands_sep]]])

number_format() returns a formatted version of number. This function accepts either one, two or four parameters (not three):

If only one parameter is given, number will be formatted without decimals, but with a comma (",") between every group of thousands.

If two parameters are given, number will be formatted with decimals decimals with a dot (".") in front, and a comma (",") between every group of thousands.

If all four parameters are given, number will be formatted with decimals decimals, dec_point instead of a dot (".") before the decimals and thousands_sep instead of a comma (",") between every group of thousands.

Note: Only the first character of thousands_sep is used. For example, if you use foo as thousands_sep on the number 1000, number_format() will return 1f000.

Example 1. number_format() Example
For instance, French notation usually use two decimals, comma (',') as decimal separator, and space (' ') as thousand separator. This is achieved with this line :
<?php $number = 1234.56; // english notation (default) $english_format_number = number_format($number); // 1,234.56 // French notation $nombre_format_francais = number_format($number, 2, ',', ' '); // 1 234,56 $number = 1234.5678; // english notation without thousands seperator $english_format_number = number_format($number, 2, '.', ''); // 1234.57 ?>

See also: sprintf(), printf() and sscanf().

ord

(PHP 3, PHP 4 )

ord -- Return ASCII value of character

Description

int ord ( string string)

Returns the ASCII value of the first character of string. This function complements chr().
Example 1. ord() example
if (ord($str) == 10) { echo "The first character of \$str is a line feed.\n"; }

You can find an ASCII-table over here: http://www.asciitable.com.

parse_str

(PHP 3, PHP 4 )

parse_str -- Parses the string into variables

Description

void parse_str ( string str [, array arr])

Parses str as if it were the query string passed via an URL and sets variables in the current scope. If the second parameter arr is present, variables are stored in this variable as an array elements instead.

Note: Support for the optional second parameter was added in PHP 4.0.3.

Note: To get the current QUERY_STRING, you may use the variable $_SERVER['QUERY_STRING']. Also, you may want to read the section on variables from outside of PHP.

Example 1. Using parse_str()
<?php $str = "first=value&arr[]=foo+bar&arr[]=baz"; parse_str($str); echo $first; // value echo $arr[0]; // foo bar echo $arr[1]; // baz parse_str($str, $output); echo $output['first']; // value echo $output['arr'][0]; // foo bar echo $output['arr'][1]; // baz ?>

print

(PHP 3, PHP 4 )

print -- Output a string

Description

print ( string arg)

Outputs arg. Returns TRUE on success or FALSE on failure.

print() is not actually a real function (it is a language construct) so you are not required to use parentheses with it.

Example 1. print() examples

<?php
print("Hello World");

print "print() also works without parentheses.";

print "This spans
multiple lines. The newlines will be 
output as well";

print "This spans\nmultiple lines. The newlines will be\noutput as well.";

print "escaping characters is done \"Like this\".";

// You can use variables inside of an print statement
$foo = "foobar";
$bar = "barbaz";

print "foo is $foo"; // foo is foobar

// Using single quotes will print the variable name, not the value
print 'foo is $foo'; // foo is $foo

// If you are not using any other characters, you can just print variables
print $foo;          // foobar

print <<<END
This uses the "here document" syntax to output
multiple lines with $variable interpolation. Note
that the here document terminator must appear on a
line with just a semicolon no extra whitespace!
END;
?>

Note: The second parameter was added in PHP 4.1.0

This function returns a string with whitespace stripped from the end of str. Without the second parameter, rtrim() will strip these characters:

" " (ASCII 32 (0x20)), an ordinary space.
"\t" (ASCII 9 (0x09)), a tab.
"\n" (ASCII 10 (0x0A)), a new line (line feed).
"\r" (ASCII 13 (0x0D)), a carriage return.
"\0" (ASCII 0 (0x00)), the NUL-byte.
"\x0B" (ASCII 11 (0x0B)), a vertical tab.

You can also specify the characters you want to strip, by means of the charlist parameter. Simply list all characters that you want to be stripped. With .. you can specify a range of characters.

Example 1. Usage example of rtrim()

<?php $text = "\t\tThese are a few words :) ... "; $trimmed = rtrim($text); // $trimmed = "\t\tThese are a few words :) ..." $trimmed = rtrim($text," \t."); // $trimmed = "\t\tThese are a few words :)" $clean = rtrim($binary,"\0x00..\0x1F"); // trim the ASCII control characters at the end of $binary // (from 0 to 31 inclusive) ?>

setlocale

(PHP 3, PHP 4 )

setlocale -- Set locale information

Description

string setlocale ( mixed category, string locale [, string ...])

string setlocale ( mixed category, array locale)

Category is a named constant (or string) specifying the category of the functions affected by the locale setting:

LC_ALL for all of the below
LC_COLLATE for string comparison, see strcoll()
LC_CTYPE for character classification and conversion, for example strtoupper()
LC_MONETARY for localeconv()
LC_NUMERIC for decimal separator (See also localeconv())
LC_TIME for date and time formatting with strftime()

If locale is the empty string "", the locale names will be set from the values of environment variables with the same names as the above categories, or from "LANG".

If locale is zero or "0", the locale setting is not affected, only the current setting is returned.

If locale is an array or followed by additional parameters then each array element or parameter is tried to be set as new locale until success. This is usefull if a locale is known under different names on different systems or for providing a fallback for a possibly not available locale.

Note: Passing multiple locales is not available before PHP 4.3

Setlocale returns the new current locale, or FALSE if the locale functionality is not implemented in the platform, the specified locale does not exist or the category name is invalid. An invalid category name also causes a warning message.

Example 1. setlocale() Examples
<?php /* Set locale to Dutch */ setlocale (LC_ALL, 'nl_NL'); /* Output: vrijdag 22 december 1978 */ echo strftime ("%A %e %B %Y", mktime (0, 0, 0, 12, 22, 1978)); /* try different possible locale names for german */ $loc_de = setlocale (LC_ALL, 'de_DE@euro', 'de_DE', 'de', 'ge'); echo "Preferred locale for german on this system is '$loc_de'"; ?>

similar_text

(PHP 3>= 3.0.7, PHP 4 )

similar_text -- Calculate the similarity between two strings

Description

int similar_text ( string first, string second [, float percent])

This calculates the similarity between two strings as described in Oliver [1993]. Note that this implementation does not use a stack as in Oliver's pseudo code, but recursive calls which may or may not speed up the whole process. Note also that the complexity of this algorithm is O(N**3) where N is the length of the longest string.

By passing a reference as third argument, similar_text() will calculate the similarity in percent for you. It returns the number of matching chars in both strings.

soundex

(PHP 3, PHP 4 )

soundex -- Calculate the soundex key of a string

Description

string soundex ( string str)

Calculates the soundex key of str.

Soundex keys have the property that words pronounced similarly produce the same soundex key, and can thus be used to simplify searches in databases where you know the pronunciation but not the spelling. This soundex function returns a string 4 characters long, starting with a letter.

This particular soundex function is one described by Donald Knuth in "The Art Of Computer Programming, vol. 3: Sorting And Searching", Addison-Wesley (1973), pp. 391-392.

Example 1. Soundex Examples
soundex("Euler") == soundex("Ellery") == 'E460'; soundex("Gauss") == soundex("Ghosh") == 'G200'; soundex("Hilbert") == soundex("Heilbronn") == 'H416'; soundex("Knuth") == soundex("Kant") == 'K530'; soundex("Lloyd") == soundex("Ladd") == 'L300'; soundex("Lukasiewicz") == soundex("Lissajous") == 'L222';

sprintf

(PHP 3, PHP 4 )

sprintf -- Return a formatted string

Description

string sprintf ( string format [, mixed args])

Returns a string produced according to the formatting string format.

The format string is composed of zero or more directives: ordinary characters (excluding %) that are copied directly to the result, and conversion specifications, each of which results in fetching its own parameter. This applies to both sprintf() and printf().

Each conversion specification consists of a percent sign (%), followed by one or more of these elements, in order:

An optional padding specifier that says what character will be used for padding the results to the right string size. This may be a space character or a 0 (zero character). The default is to pad with spaces. An alternate padding character can be specified by prefixing it with a single quote ('). See the examples below.
An optional alignment specifier that says if the result should be left-justified or right-justified. The default is right-justified; a - character here will make it left-justified.
An optional number, a width specifier that says how many characters (minimum) this conversion should result in.
An optional precision specifier that says how many decimal digits should be displayed for floating-point numbers. This option has no effect for other types than float. (Another function useful for formatting numbers is number_format().)

A type specifier that says what type the argument data should be treated as. Possible types:

% - a literal percent character. No argument is required.

b - the argument is treated as an integer, and presented as a binary number.

c - the argument is treated as an integer, and presented as the character with that ASCII value.

d - the argument is treated as an integer, and presented as a (signed) decimal number.

u - the argument is treated as an integer, and presented as an unsigned decimal number.

f - the argument is treated as a float, and presented as a floating-point number.

o - the argument is treated as an integer, and presented as an octal number.

s - the argument is treated as and presented as a string.

string str_repeat ( string input, int multiplier)

Returns input_str repeated multiplier times. multiplier has to be greater than or equal to 0. If the multiplier is set to 0, the function will return an empty string.

Example 1. str_repeat() example

echo str_repeat("-=", 10);

This will output "-=-=-=-=-=-=-=-=-=-=".

See also for, str_pad(), and substr_count().

str_replace

(PHP 3>= 3.0.6, PHP 4 )

str_replace -- Replace all occurrences of the search string with the replacement string

Description

mixed str_replace ( mixed search, mixed replace, mixed subject)

This function returns a string or an array with all occurences of search in subject replaced with the given replace value. If you don't need fancy replacing rules, you should always use this function instead of ereg_replace() or preg_replace().

In PHP 4.0.5 and later, every parameter to str_replace() can be an array.

If subject is an array, then the search and replace is performed with every entry of subject, and the return value is an array as well.

If search and replace are arrays, then str_replace() takes a value from each array and uses them to do search and replace on subject. If replace has fewer values than search, then an empty string is used for the rest of replacement values. If search is an array and replace is a string; then this replacement string is used for every value of search.

Example 1. str_replace() example
$bodytag = str_replace("%body%", "black", "<body text=%body%>");

This function is binary safe.

Note: str_replace() was added in PHP 3.0.6, but was buggy up until PHP 3.0.8.

str_rot13

(PHP 4 >= 4.2.0)

str_rot13 -- Perform the rot13 transform on a string

Description

string str_rot13 ( string str)

This function performs the ROT13 encoding on the str argument and returns the resulting string. The ROT13 encoding simply shifts every letter by 13 places in the alphabet while leaving non-alpha characters untouched. Encoding and decoding are done by the same function, passing an encoded string as argument will return the original version.

str_word_count

(no version information, might be only in CVS)

str_word_count -- Return information about words used in a string

Description

mixed str_word_count ( string string [, int format])

Counts the number of words inside string. If the optional format is not specified, then the return value will be an integer representing the number of words found. In the event the format is specified, the return value will be an array, content of which is dependent on the format. The possible value for the format and the resultant outputs are listed below.

1 - returns an array containing all the words found inside the string.
2 - returns an associative array, where the key is the numeric position of the word inside the string and the value is the actual word itself.

Returns < 0 if str1 is less than str2; > 0 if str1 is greater than str2, and 0 if they are equal.

Note that this comparison is case sensitive.

strcoll

(PHP 4 >= 4.0.5)

strcoll -- Locale based string comparison

Description

int strcoll ( string str1, string str2)

Returns < 0 if str1 is less than str2; > 0 if str1 is greater than str2, and 0 if they are equal. strcoll() uses the current locale for doing the comparisons. If the current locale is C or POSIX, this function is equivalent to strcmp().

Note that this comparison is case sensitive, and unlike strcmp() this function is not binary safe.

Note: strcoll() was added in PHP 4.0.5, but was not enabled for win32 until 4.2.3.

strcspn

(PHP 3>= 3.0.3, PHP 4 )

strcspn -- Find length of initial segment not matching mask

Description

int strcspn ( string str1, string str2)

Returns the length of the initial segment of str1 which does not contain any of the characters in str2.

strip_tags

(PHP 3>= 3.0.8, PHP 4 )

strip_tags -- Strip HTML and PHP tags from a string

Description

string strip_tags ( string str [, string allowable_tags])

This function tries to return a string with all HTML and PHP tags stripped from a given str. It errors on the side of caution in case of incomplete or bogus tags. It uses the same tag stripping state machine as the fgetss() function.

You can use the optional second parameter to specify tags which should not be stripped.

Note: allowable_tags was added in PHP 3.0.13 and PHP 4.0b3.

Example 1. strip_tags() example
$string = strip_tags($string, '<a><b><i><u>');

string stristr ( string haystack, string needle)

Returns all of haystack from the first occurrence of needle to the end. needle and haystack are examined in a case-insensitive manner.

If needle is not found, returns FALSE.

If needle is not a string, it is converted to an integer and applied as the ordinal value of a character.

strlen

(PHP 3, PHP 4 )

strlen -- Get string length

Description

int strlen ( string str)

Returns the length of string.

strnatcasecmp

(PHP 4 )

strnatcasecmp -- Case insensitive string comparisons using a "natural order" algorithm

Description

int strnatcasecmp ( string str1, string str2)

This function implements a comparison algorithm that orders alphanumeric strings in the way a human being would. The behaviour of this function is similar to strnatcmp(), except that the comparison is not case sensitive. For more infomation see: Martin Pool's Natural Order String Comparison page.

Similar to other string comparison functions, this one returns < 0 if str1 is less than str2; > 0 if str1 is greater than str2, and 0 if they are equal.

strnatcmp

(PHP 4 )

strnatcmp -- String comparisons using a "natural order" algorithm

Description

int strnatcmp ( string str1, string str2)

This function implements a comparison algorithm that orders alphanumeric strings in the way a human being would, this is described as a "natural ordering". An example of the difference between this algorithm and the regular computer string sorting algorithms (used in strcmp()) can be seen below:

$arr1 = $arr2 = array("img12.png","img10.png","img2.png","img1.png");
echo "Standard string comparison\n";
usort($arr1,"strcmp");
print_r($arr1);
echo "\nNatural order string comparison\n";
usort($arr2,"strnatcmp");
print_r($arr2);

The code above will generate the following output:

Standard string comparison
Array
(
    [0] => img1.png
    [1] => img10.png
    [2] => img12.png
    [3] => img2.png
)

Natural order string comparison
Array
(
    [0] => img1.png
    [1] => img2.png
    [2] => img10.png
    [3] => img12.png
)

For more information see: Martin Pool's Natural Order String Comparison page.

Similar to other string comparison functions, this one returns < 0 if str1 is less than str2; > 0 if str1 is greater than str2, and 0 if they are equal.

Note that this comparison is case sensitive.

strncasecmp

(PHP 4 >= 4.0.2)

strncasecmp -- Binary safe case-insensitive string comparison of the first n characters

Description

int strncasecmp ( string str1, string str2, int len)

This function is similar to strcasecmp(), with the difference that you can specify the (upper limit of the) number of characters (len) from each string to be used in the comparison. If any of the strings is shorter than len, then the length of that string will be used for the comparison.

Returns < 0 if str1 is less than str2; > 0 if str1 is greater than str2, and 0 if they are equal.

strncmp

(PHP 4 )

strncmp -- Binary safe string comparison of the first n characters

Description

int strncmp ( string str1, string str2, int len)

This function is similar to strcmp(), with the difference that you can specify the (upper limit of the) number of characters (len) from each string to be used in the comparison. If any of the strings is shorter than len, then the length of that string will be used for the comparison.

Returns < 0 if str1 is less than str2; > 0 if str1 is greater than str2, and 0 if they are equal.

Note that this comparison is case sensitive.

strpos

(PHP 3, PHP 4 )

strpos -- Find position of first occurrence of a string

Description

int strpos ( string haystack, string needle [, int offset])

Returns the numeric position of the first occurrence of needle in the haystack string. Unlike the strrpos(), this function can take a full string as the needle parameter and the entire string will be used.

If needle is not found, returns FALSE.

Note: It is easy to mistake the return values for "character found at position 0" and "character not found". Here's how to detect the difference:
// in PHP 4.0b3 and newer:
$pos = strpos($mystring, "b");
if ($pos === false) { // note: three equal signs
    // not found...
}

// in versions older than 4.0b3:
$pos = strpos($mystring, "b");
if (!is_integer($pos)) {
    // not found...
}

If needle is not a string, it is converted to an integer and applied as the ordinal value of a character.

The optional offset parameter allows you to specify which character in haystack to start searching. The position returned is still relative to the the beginning of haystack.

strrchr

(PHP 3, PHP 4 )

strrchr -- Find the last occurrence of a character in a string

Description

string strrchr ( string haystack, string needle)

This function returns the portion of haystack which starts at the last occurrence of needle and goes until the end of haystack.

Returns FALSE if needle is not found.

If needle contains more than one character, the first is used.

If needle is not a string, it is converted to an integer and applied as the ordinal value of a character.
Example 1. strrchr() example
// get last directory in $PATH $dir = substr(strrchr($PATH, ":"), 1); // get everything after last newline $text = "Line 1\nLine 2\nLine 3"; $last = substr(strrchr($text, 10), 1 );

strrev

(PHP 3, PHP 4 )

strrev -- Reverse a string

Description

If needle is not a string, it is converted to an integer and applied as the ordinal value of a character.

Note: This function is case-sensitive. For case-insensitive searches, use stristr().

Examples:

$trans = array("hello" => "hi", "hi" => "hello");
echo strtr("hi all, I said hello", $trans) . "\n";

This will show: "hello all, I said hi",

Note: This optional to and from parameters were added in PHP 4.0.0

substr_count

(PHP 4 )

substr_count -- Count the number of substring occurrences

Description

int substr_count ( string haystack, string needle)

substr_count() returns the number of times the needle substring occurs in the haystack string.

Example 1. substr_count() example
print substr_count("This is a test", "is"); // prints out 2

substr_replace

(PHP 4 )

substr_replace -- Replace text within a portion of a string

Description

string substr_replace ( string string, string replacement, int start [, int length])

substr_replace() replaces a copy of string delimited by the start and (optionally) length parameters with the string given in replacement. The result is returned.

If start is positive, the replacing will begin at the start'th offset into string.

If start is negative, the replacing will begin at the start'th character from the end of string.

If length is given and is positive, it represents the length of the portion of string which is to be replaced. If it is negative, it represents the number of characters from the end of string at which to stop replacing. If it is not given, then it will default to strlen( string ); i.e. end the replacing at the end of string.

Example 1. substr_replace() example
<?php $var = 'ABCDEFGH:/MNRPQR/'; echo "Original: $var<hr>\n"; /* These two examples replace all of $var with 'bob'. */ echo substr_replace($var, 'bob', 0) . "<br>\n"; echo substr_replace($var, 'bob', 0, strlen($var)) . "<br>\n"; /* Insert 'bob' right at the beginning of $var. */ echo substr_replace($var, 'bob', 0, 0) . "<br>\n"; /* These next two replace 'MNRPQR' in $var with 'bob'. */ echo substr_replace($var, 'bob', 10, -1) . "<br>\n"; echo substr_replace($var, 'bob', -7, -1) . "<br>\n"; /* Delete 'MNRPQR' from $var. */ echo substr_replace($var, '', 10, -1) . "<br>\n"; ?>

See also str_replace() and substr().

substr

(PHP 3, PHP 4 )

substr -- Return part of a string

Description

string substr ( string string, int start [, int length])

Substr returns the portion of string specified by the start and length parameters.

If start is non-negative, the returned string will start at the start'th position in string, counting from zero. For instance, in the string 'abcdef', the character at position 0 is 'a', the character at position 2 is 'c', and so forth.

Example 1. Basic substr() usage

<?php
$rest = substr("abcdef", 1);    // returns "bcdef"
$rest = substr("abcdef", 1, 3); // returns "bcd"
$rest = substr("abcdef", 0, 4); // returns "abcd"
$rest = substr("abcdef", 0, 8); // returns "abcdef"

// Accessing via curly braces is another option
$string = 'abcdef';
echo $string{0};                // returns a
echo $string{3};                // returns d
?>

If start is negative, the returned string will start at the start'th character from the end of string.

Example 2. Using a negative start

<?php
$rest = substr("abcdef", -1);    // returns "f"
$rest = substr("abcdef", -2);    // returns "ef"
$rest = substr("abcdef", -3, 1); // returns "d"
?>

If length is given and is positive, the string returned will contain at most length characters beginning from start (depending on the length of string. If string is less than start characters long, FALSE will be returned.

If length is given and is negative, then that many characters will be omitted from the end of string (after the start position has been calculated when a start is negative). If start denotes a position beyond this truncation, an empty string will be returned.

Example 3. Using a negative length

<?php
$rest = substr("abcdef", 0, -1);  // returns "abcde"
$rest = substr("abcdef", 2, -1);  // returns "cde"
$rest = substr("abcdef", 4, -4);  // returns ""
$rest = substr("abcdef", -3, -1); // returns "de"
?>

trim

(PHP 3, PHP 4 )

trim -- Strip whitespace from the beginning and end of a string

Description

string trim ( string str [, string charlist])

Note: The optional charlist parameter was added in PHP 4.1.0

This function returns a string with whitespace stripped from the beginning and end of str. Without the second parameter, trim() will strip these characters:

" " (ASCII 32 (0x20)), an ordinary space.
"\t" (ASCII 9 (0x09)), a tab.
"\n" (ASCII 10 (0x0A)), a new line (line feed).
"\r" (ASCII 13 (0x0D)), a carriage return.
"\0" (ASCII 0 (0x00)), the NUL-byte.
"\x0B" (ASCII 11 (0x0B)), a vertical tab.

string vsprintf ( string format, array args)

Return array values as a formatted string according to format (which is described in the documentation for sprintf()).

Operates as sprintf() but accepts an array of arguments, rather than a variable number of arguments.

See also sprintf(), vsprintf(), vprintf()

wordwrap

(PHP 4 >= 4.0.2)

wordwrap -- Wraps a string to a given number of characters using a string break character.

Description

string wordwrap ( string str [, int width [, string break [, int cut]]])

Returns a string with str wrapped at the column number specified by the (optional) width parameter. The line is broken using the (optional) break parameter.

wordwrap() will automatically wrap at column 75 and break using '\n' (newline) if width or break are not given.

If the cut is set to 1, the string is always wrapped at the specified width. So if you have a word that is larger than the given width, it is broken apart. (See second example).

Note: The optional cut parameter was added in PHP 4.0.3

Example 1. wordwrap() example
$text = "The quick brown fox jumped over the lazy dog."; $newtext = wordwrap( $text, 20 ); echo "$newtext\n";

This example would display:

The quick brown fox
jumped over the lazy dog.

Example 2. wordwrap() example
$text = "A very long woooooooooooord."; $newtext = wordwrap( $text, 8, "\n", 1); echo "$newtext\n";

This example would display:

A very
long
wooooooo
ooooord.

XCIX. Sybase functions

Introduction

Requirements

Installation

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Sybase configuration options

Name	Default	Changeable
sybase.allow_persistent	"On"	PHP_INI_SYSTEM
sybase.max_persistent	"-1"	PHP_INI_SYSTEM
sybase.max_links	"-1"	PHP_INI_SYSTEM
sybase.interface_file	"/usr/sybase/interfaces"	PHP_INI_SYSTEM
sybase.min_error_severity	"10"	PHP_INI_ALL
sybase.min_message_severity	"10"	PHP_INI_ALL
sybase.compatability_mode	"Off"	PHP_INI_SYSTEM
magic_quotes_sybase	"Off"	PHP_INI_ALL

Here is a short explanation of the configuration directives.

sybase.allow_persistent boolean: Whether to allow persistent Sybase connections.
sybase.max_persistent integer: The maximum number of persistent Sybase connections per process. -1 means no limit.
sybase.max_links integer: The maximum number of Sybase connections per process, including persistent connections. -1 means no limit.
sybase.min_error_severity integer: Minimum error severity to display.
sybase.min_message_severity integer: Minimum message severity to display.
sybase.compatability_mode boolean: Compatability mode with old versions of PHP 3.0. If on, this will cause PHP to automatically assign types to results according to their Sybase type, instead of treating them all as strings. This compatability mode will probably not stay around forever, so try applying whatever necessary changes to your code, and turn it off.
magic_quotes_sybase boolean: If magic_quotes_sybase is also on, a single-quote is escaped with a single-quote instead of a backslash if magic_quotes_gpc or magic_quotes_runtime is enabled.

Table 2. Sybase-CT configuration options

Name	Default	Changeable
sybct.allow_persistent	"On"	PHP_INI_SYSTEM
sybct.max_persistent	"-1"	PHP_INI_SYSTEM
sybct.max_links	"-1"	PHP_INI_SYSTEM
sybct.min_server_severity	"10"	PHP_INI_ALL
sybct.min_client_severity	"10"	PHP_INI_ALL
sybct.hostname	NULL	PHP_INI_ALL

Here is a short explanation of the configuration directives.

sybct.allow_persistent boolean: Whether to allow persistent Sybase-CT connections. The default is on.
sybct.max_persistent integer: The maximum number of persistent Sybase-CT connections per process. The default is -1 meaning unlimited.
sybct.max_links integer: The maximum number of Sybase-CT connections per process, including persistent connections. The default is -1 meaning unlimited.
sybct.min_server_severity integer: Server messages with severity greater than or equal to sybct.min_server_severity will be reported as warnings. This value can also be set from a script by calling sybase_min_server_severity(). The default is 10 which reports errors of information severity or greater.
sybct.min_client_severity integer: Client library messages with severity greater than or equal to sybct.min_client_severity will be reported as warnings. This value can also be set from a script by calling sybase_min_client_severity(). The default is 10 which effectively disables reporting.
sybct.hostname string: The name of the host you claim to be connecting from, for display by sp_who. The default is none.

For further details and definition of the PHP_INI_* constants see ini_set().

Resource Types

Predefined Constants

This extension has no constants defined.

Table of Contents
sybase_affected_rows -- get number of affected rows in last query
sybase_close -- close Sybase connection
sybase_connect -- open Sybase server connection
sybase_data_seek -- move internal row pointer
sybase_fetch_array -- fetch row as array
sybase_fetch_field -- get field information
sybase_fetch_object -- fetch row as object
sybase_fetch_row -- get row as enumerated array
sybase_field_seek -- set field offset
sybase_free_result -- free result memory
sybase_get_last_message -- Returns the last message from the server
sybase_min_client_severity -- Sets minimum client severity
sybase_min_error_severity -- Sets minimum error severity
sybase_min_message_severity -- Sets minimum message severity
sybase_min_server_severity -- Sets minimum server severity
sybase_num_fields -- get number of fields in result
sybase_num_rows -- get number of rows in result
sybase_pconnect -- open persistent Sybase connection
sybase_query -- send Sybase query
sybase_result -- get result data
sybase_select_db -- select Sybase database

sybase_affected_rows

(PHP 3>= 3.0.6, PHP 4 )

sybase_affected_rows -- get number of affected rows in last query

Description

int sybase_affected_rows ( [int link_identifier])

Returns: The number of affected rows by the last query.

sybase_affected_rows() returns the number of rows affected by the last INSERT, UPDATE or DELETE query on the server associated with the specified link identifier. If the link identifier isn't specified, the last opened link is assumed.

This command is not effective for SELECT statements, only on statements which modify records. To retrieve the number of rows returned from a SELECT, use sybase_num_rows().

Note: This function is only available using the CT library interface to Sybase, and not the DB library.

sybase_fetch_array -- fetch row as array

Description

array sybase_fetch_array ( int result)

Returns: An array that corresponds to the fetched row, or FALSE if there are no more rows.

sybase_fetch_array() is an extended version of sybase_fetch_row(). In addition to storing the data in the numeric indices of the result array, it also stores the data in associative indices, using the field names as keys.

An important thing to note is that using sybase_fetch_array() is NOT significantly slower than using sybase_fetch_row(), while it provides a significant added value.

For further details, also see sybase_fetch_row().

sybase_fetch_field

(PHP 3, PHP 4 )

sybase_fetch_field -- get field information

Description

object sybase_fetch_field ( int result [, int field_offset])

Returns an object containing field information.

sybase_fetch_field() can be used in order to obtain information about fields in a certain query result. If the field offset isn't specified, the next field that wasn't yet retreived by sybase_fetch_field() is retreived.

The properties of the object are:

name - column name. if the column is a result of a function, this property is set to computed#N, where #N is a serial number.
column_source - the table from which the column was taken
max_length - maximum length of the column
numeric - 1 if the column is numeric
type - datatype of the column

sybase_fetch_object

(PHP 3, PHP 4 )

sybase_fetch_object -- fetch row as object

Description

int sybase_fetch_object ( int result)

Returns: An object with properties that correspond to the fetched row, or FALSE if there are no more rows.

Note: This function is only available using the CT library interface to Sybase, and not the DB library.

Second, the connection to the SQL server will not be closed when the execution of the script ends. Instead, the link will remain open for future use (sybase_close() will not close links established by sybase_pconnect()()).

This type of links is therefore called 'persistent'.

sybase_query

(PHP 3, PHP 4 )

sybase_query -- send Sybase query

Description

int sybase_query ( string query, int link_identifier)

Returns: A positive Sybase result identifier on success, or FALSE on error.

sybase_query() sends a query to the currently active database on the server that's associated with the specified link identifier. If the link identifier isn't specified, the last opened link is assumed. If no link is open, the function tries to establish a link as if sybase_connect() was called, and use it.

See also: sybase_db_query(), sybase_select_db(), and sybase_connect().

sybase_result

(PHP 3, PHP 4 )

sybase_result -- get result data

Description

string sybase_result ( int result, int row, mixed field)

Returns: The contents of the cell at the row and offset in the specified Sybase result set.

sybase_result() returns the contents of one cell from a Sybase result set. The field argument can be the field's offset, or the field's name, or the field's table dot field's name (tablename.fieldname). If the column name has been aliased ('select foo as bar from...'), use the alias instead of the column name.

When working on large result sets, you should consider using one of the functions that fetch an entire row (specified below). As these functions return the contents of multiple cells in one function call, they're MUCH quicker than sybase_result(). Also, note that specifying a numeric offset for the field argument is much quicker than specifying a fieldname or tablename.fieldname argument.

Recommended high-performance alternatives: sybase_fetch_row(), sybase_fetch_array(), and sybase_fetch_object().

sybase_select_db

(PHP 3, PHP 4 )

sybase_select_db -- select Sybase database

Description

bool sybase_select_db ( string database_name, int link_identifier)

Returns: TRUE on success, FALSE on error

sybase_select_db() sets the current active database on the server that's associated with the specified link identifier. If no link identifier is specified, the last opened link is assumed. If no link is open, the function will try to establish a link as if sybase_connect() was called, and use it.

Every subsequent call to sybase_query() will be made on the active database.

C. Tokenizer functions

Introduction

Warning

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Tokenizer Configuration Options

Name	Default	Changeable
tokenizer.global_value	"42"	PHP_INI_ALL
tokenizer.global_string	"foobar"	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

T_INCLUDE (integer)
T_INCLUDE_ONCE (integer)
T_EVAL (integer)
T_REQUIRE (integer)
T_REQUIRE_ONCE (integer)
T_LOGICAL_OR (integer)
T_LOGICAL_XOR (integer)
T_LOGICAL_AND (integer)
T_PRINT (integer)
T_PLUS_EQUAL (integer)
T_MINUS_EQUAL (integer)
T_MUL_EQUAL (integer)
T_DIV_EQUAL (integer)
T_CONCAT_EQUAL (integer)
T_MOD_EQUAL (integer)
T_AND_EQUAL (integer)
T_OR_EQUAL (integer)
T_XOR_EQUAL (integer)
T_SL_EQUAL (integer)
T_SR_EQUAL (integer)
T_BOOLEAN_OR (integer)
T_BOOLEAN_AND (integer)
T_IS_EQUAL (integer)
T_IS_NOT_EQUAL (integer)
T_IS_IDENTICAL (integer)
T_IS_NOT_IDENTICAL (integer)
T_IS_SMALLER_OR_EQUAL (integer)
T_IS_GREATER_OR_EQUAL (integer)
T_SL (integer)
T_SR (integer)
T_INC (integer)
T_DEC (integer)
T_INT_CAST (integer)
T_DOUBLE_CAST (integer)
T_STRING_CAST (integer)
T_ARRAY_CAST (integer)
T_OBJECT_CAST (integer)
T_BOOL_CAST (integer)
T_UNSET_CAST (integer)
T_NEW (integer)
T_EXIT (integer)
T_IF (integer)
T_ELSEIF (integer)
T_ELSE (integer)
T_ENDIF (integer)
T_LNUMBER (integer)
T_DNUMBER (integer)
T_STRING (integer)
T_STRING_VARNAME (integer)
T_VARIABLE (integer)
T_NUM_STRING (integer)
T_INLINE_HTML (integer)
T_CHARACTER (integer)
T_BAD_CHARACTER (integer)
T_ENCAPSED_AND_WHITESPACE (integer)
T_CONSTANT_ENCAPSED_STRING (integer)
T_ECHO (integer)
T_DO (integer)
T_WHILE (integer)
T_ENDWHILE (integer)
T_FOR (integer)
T_ENDFOR (integer)
T_FOREACH (integer)
T_ENDFOREACH (integer)
T_DECLARE (integer)
T_ENDDECLARE (integer)
T_AS (integer)
T_SWITCH (integer)
T_ENDSWITCH (integer)
T_CASE (integer)
T_DEFAULT (integer)
T_BREAK (integer)
T_CONTINUE (integer)
T_OLD_FUNCTION (integer)
T_FUNCTION (integer)
T_CONST (integer)
T_RETURN (integer)
T_USE (integer)
T_GLOBAL (integer)
T_STATIC (integer)
T_VAR (integer)
T_UNSET (integer)
T_ISSET (integer)
T_EMPTY (integer)
T_CLASS (integer)
T_EXTENDS (integer)
T_OBJECT_OPERATOR (integer)
T_DOUBLE_ARROW (integer)
T_LIST (integer)
T_ARRAY (integer)
T_LINE (integer)
T_FILE (integer)
T_COMMENT (integer)
T_ML_COMMENT (integer)
T_OPEN_TAG (integer)
T_OPEN_TAG_WITH_ECHO (integer)
T_CLOSE_TAG (integer)
T_WHITESPACE (integer)
T_START_HEREDOC (integer)
T_END_HEREDOC (integer)
T_DOLLAR_OPEN_CURLY_BRACES (integer)
T_CURLY_OPEN (integer)
T_PAAMAYIM_NEKUDOTAYIM (integer)
T_DOUBLE_COLON (integer)

Table of Contents
token_get_all -- Split given source in tokens
token_name -- Get the name of a given token

token_get_all

(PHP 4 >= 4.2.0)

token_get_all -- Split given source in tokens

Description

array token_get_all ( string source)

Warning

This function is currently not documented; only the argument list is available.

token_name

(PHP 4 >= 4.2.0)

token_name -- Get the name of a given token

Description

string token_name ( int type)

Warning

This function is currently not documented; only the argument list is available.

CI. URL Functions

Introduction

Dealing with URL strings: encoding, decoding and parsing.

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Table of Contents
base64_decode -- Decodes data encoded with MIME base64
base64_encode -- Encodes data with MIME base64
parse_url -- Parse a URL and return its components
rawurldecode -- Decode URL-encoded strings
rawurlencode -- URL-encode according to RFC 1738
urldecode -- Decodes URL-encoded string
urlencode -- URL-encodes string

base64_decode

(PHP 3, PHP 4 )

base64_decode -- Decodes data encoded with MIME base64

Description

string base64_decode ( string encoded_data)

base64_decode() decodes encoded_data and returns the original data. The returned data may be binary.

See also: base64_encode(), RFC 2045 section 6.8.

base64_encode

(PHP 3, PHP 4 )

base64_encode -- Encodes data with MIME base64

Description

string base64_encode ( string data)

base64_encode() returns data encoded with base64. This encoding is designed to make binary data survive transport through transport layers that are not 8-bit clean, such as mail bodies.

Base64-encoded data takes about 33% more space than the original data.

See also: base64_decode(), chunk_split(), RFC 2045 section 6.8.

parse_url

(PHP 3, PHP 4 )

parse_url -- Parse a URL and return its components

Description

array parse_url ( string url)

This function returns an associative array returning any of the various components of the URL that are present. This includes the

scheme - e.g. http
host
port
user
pass
path
query - after the question mark ?
fragment - after the hashmark #

This function is not meant to validate the given URL, it only breaks it up into the above listed parts. Partial urls are also accepted, parse_url() tries its best to parse them correctly.

Example 1. Using parse_url()

$ php -r 'print_r( parse_url("http://username:password@hostname/path?arg=value#anchor"));'
Array
(
    [scheme] => http
    [host] => hostname
    [user] => username
    [pass] => password
    [path] => /path
    [query] => arg=value
    [fragment] => anchor
)

$ php -r 'print_r( parse_url("http://invalid_host..name/"));'
Array
(
    [scheme] => http
    [host] => invalid_host..name
    [path] => /
)

rawurldecode

(PHP 3, PHP 4 )

rawurldecode -- Decode URL-encoded strings

Description

string rawurldecode ( string str)

Returns a string in which the sequences with percent (%) signs followed by two hex digits have been replaced with literal characters. For example, the string
foo%20bar%40baz
decodes into
foo bar@baz
.

Note: rawurldecode() does not decode plus symbols ('+') into spaces. urldecode() does.

rawurlencode

(PHP 3, PHP 4 )

rawurlencode -- URL-encode according to RFC 1738

Description

string rawurlencode ( string str)

Returns a string in which all non-alphanumeric characters except
-_.
have been replaced with a percent (%) sign followed by two hex digits. This is the encoding described in RFC 1738 for protecting literal characters from being interpreted as special URL delimiters, and for protecting URL's from being mangled by transmission media with character conversions (like some email systems). For example, if you want to include a password in an FTP URL:

Example 1. rawurlencode() example 1

echo '<a href="ftp://user:', rawurlencode('foo @+%/'),
     '@ftp.my.com/x.txt">';

Or, if you pass information in a PATH_INFO component of the URL:

Example 2. rawurlencode() example 2

echo '<a href="http://x.com/department_list_script/',
    rawurlencode('sales and marketing/Miami'), '">';

urldecode

(PHP 3, PHP 4 )

urldecode -- Decodes URL-encoded string

Description

string urldecode ( string str)

Decodes any %## encoding in the given string. The decoded string is returned.
Example 1. urldecode() example
$a = explode('&', $QUERY_STRING); $i = 0; while ($i < count($a)) { $b = split('=', $a[$i]); echo 'Value for parameter ', htmlspecialchars(urldecode($b[0])), ' is ', htmlspecialchars(urldecode($b[1])), "<br />\n"; $i++; }

urlencode

(PHP 3, PHP 4 )

urlencode -- URL-encodes string

Description

string urlencode ( string str)

Returns a string in which all non-alphanumeric characters except -_. have been replaced with a percent (%) sign followed by two hex digits and spaces encoded as plus (+) signs. It is encoded the same way that the posted data from a WWW form is encoded, that is the same way as in application/x-www-form-urlencoded media type. This differs from the RFC1738 encoding (see rawurlencode()) in that for historical reasons, spaces are encoded as plus (+) signs. This function is convenient when encoding a string to be used in a query part of an URL, as a convenient way to pass variables to the next page:
Example 1. urlencode() example
echo '<a href="mycgi?foo=', urlencode($userinput), '">';

Note: Be careful about variables that may match HTML entities. Things like &amp, &copy and &pound are parsed by the browser and the actual entity is used instead of the desired variable name. This is an obvious hassle that the W3C has been telling people about for years. The reference is here: http://www.w3.org/TR/html4/appendix/notes.html#h-B.2.2 PHP supports changing the argument separator to the W3C-suggested semi-colon through the arg_separator .ini directive. Unfortunately most user agents do not send form data in this semi-colon separated format. A more portable way around this is to use & instead of & as the separator. You don't need to change PHP's arg_separator for this. Leave it as &, but simply encode your URLs using htmlentities()(urlencode($data)).
Example 2. urlencode/htmlentities() example
echo '<a href="mycgi?foo=', htmlentities(urlencode($userinput)), '">';

CII. Variable Functions

Introduction

For information on how variables behave, see the Variables entry in the Language Reference section of the manual.

Requirements

No external libraries are needed to build this extension.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. Variables Configuration Options

Name	Default	Changeable
unserialize_callback_func	""	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Here is a short explanation of the configuration directives.

unserialize_callback_func string

The unserialize callback function will called (with the undefind class' name as parameter), if the unserializer finds an undefined class which should be instanciated. A warning appears if the specified function is not defined, or if the function doesn't include/implement the missing class. So only set this entry, if you really want to implement such a callback-function.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Table of Contents
doubleval -- Alias of floatval()
empty -- Determine whether a variable is set
floatval -- Get float value of a variable
get_defined_vars -- Returns an array of all defined variables
get_resource_type -- Returns the resource type
gettype -- Get the type of a variable
import_request_variables -- Import GET/POST/Cookie variables into the global scope
intval -- Get integer value of a variable
is_array -- Finds whether a variable is an array
is_bool -- Finds out whether a variable is a boolean
is_callable -- Find out whether the argument is a valid callable construct
is_double -- Alias of is_float()
is_float -- Finds whether a variable is a float
is_int -- Find whether a variable is an integer
is_integer -- Alias of is_int()
is_long -- Alias of is_int()
is_null -- Finds whether a variable is NULL
is_numeric -- Finds whether a variable is a number or a numeric string
is_object -- Finds whether a variable is an object
is_real -- Alias of is_float()
is_resource -- Finds whether a variable is a resource
is_scalar -- Finds whether a variable is a scalar
is_string -- Finds whether a variable is a string
isset -- Determine whether a variable is set
print_r -- Prints human-readable information about a variable
serialize -- Generates a storable representation of a value
settype -- Set the type of a variable
strval -- Get string value of a variable
unserialize -- Creates a PHP value from a stored representation
unset -- Unset a given variable
var_dump -- Dumps information about a variable
var_export -- Outputs or returns a string representation of a variable

doubleval

doubleval -- Alias of floatval()

Description

This function is an alias of floatval().

Note: This alias is a left-over from a function-renaming. In older versions of PHP you'll need to use this alias of the floatval() function, because floatval() wasn't yet available in that version.

empty

(PHP 3, PHP 4 )

empty -- Determine whether a variable is set

Description

boolean empty ( mixed var)

Note: empty() is a language construct.

This is the opposite of (boolean) var, except that no warning is generated when the variable is not set. See converting to boolean for more information.

$var = 0;

if (empty($var)) {  // evaluates true
    echo '$var is either 0 or not set at all';
}

if (!isset($var)) { // evaluates false
    echo '$var is not set at all';
}

Note that this is meaningless when used on anything which isn't a variable; i.e. empty (addslashes ($name)) has no meaning since it would be checking whether something which isn't a variable is a variable with a FALSE value.

floatval

(PHP 4 >= 4.2.0)

floatval -- Get float value of a variable

Description

float floatval ( mixed var)

Returns the float value of var.

Var may be any scalar type. You cannot use floatval() on arrays or objects.

$var = '122.34343The';
$float_value_of_var = floatval ($var);
print $float_value_of_var; // prints 122.34343

get_defined_vars

(PHP 4 >= 4.0.4)

get_defined_vars -- Returns an array of all defined variables

Description

array get_defined_vars ( void)

This function returns an multidimensional array containing a list of all defined variables, be them environment, server or user-defined variables.

$b = array(1,1,2,3,5,8);

$arr = get_defined_vars();

// print $b
print_r($arr["b"]);

// print path to the PHP interpreter (if used as a CGI)
// e.g. /usr/local/bin/php
echo $arr["_"];

// print the command-line paramaters if any
print_r($arr["argv"]);

// print all the server vars
print_r($arr["_SERVER"]);

// print all the available keys for the arrays of variables
print_r(array_keys(get_defined_vars()));

get_resource_type

(PHP 4 >= 4.0.2)

get_resource_type -- Returns the resource type

Description

string get_resource_type ( resource handle)

This function returns a string representing the type of the resource passed to it. If the paramater is not a valid resource, it generates an error.

$c = mysql_connect();
echo get_resource_type($c)."\n";
// prints: mysql link

$fp = fopen("foo","w");
echo get_resource_type($fp)."\n";
// prints: file

$doc = new_xmldoc("1.0");
echo get_resource_type($doc->doc)."\n";
// prints: domxml document

gettype

(PHP 3, PHP 4 )

gettype -- Get the type of a variable

Description

string gettype ( mixed var)

Returns the type of the PHP variable var.

Warning

Never use gettype() to test for a certain type, since the returned string may be subject to change in a future version. In addition, it is slow too, as it involves string comparision .

Instead, use the is_* functions.

Possibles values for the returned string are:

"boolean" (since PHP 4)
"integer"
"double" (for historical reasons "double" is returned in case of a float, and not simply "float")
"string"
"array"
"object"
"resource" (since PHP 4)
"NULL" (since PHP 4)
"user function" (PHP 3 only, deprecated)
"unknown type"

For PHP 4, you should use function_exists() and method_exists() to replace the prior usage of gettype() on a function.

import_request_variables

(PHP 4 >= 4.1.0)

import_request_variables -- Import GET/POST/Cookie variables into the global scope

Description

bool import_request_variables ( string types [, string prefix])

Imports GET/POST/Cookie variables into the global scope. It is useful if you disabled register_globals, but would like to see some variables in the global scope.

Using the types parameter, you can specify which request variables to import. You can use 'G', 'P' and 'C' characters respectively for GET, POST and Cookie. These characters are not case sensitive, so you can also use any combination of 'g', 'p' and 'c'. POST includes the POST uploaded file information. Note that the order of the letters matters, as when using "gp", the POST variables will overwrite GET variables with the same name. Any other letters than GPC are discarded.

The prefix parameter is used as a variable name prefix, prepended before all variable's name imported into the global scope. So if you have a GET value named "userid", and provide a prefix "pref_", then you'll get a global variable named $pref_userid.

If you're interested in importing other variables into the global scope, such as SERVER, consider using extract().

Note: Although the prefix parameter is optional, you will get an E_NOTICE level error if you specify no prefix, or specify an empty string as a prefix. This is a possible security hazard. Notice level errors are not displayed using the default error reporting level.

// This will import GET and POST vars
// with an "rvar_" prefix
import_request_variables("gP", "rvar_");

print $rvar_foo;

intval

(PHP 3, PHP 4 )

intval -- Get integer value of a variable

Description

int intval ( mixed var [, int base])

Returns the integer value of var, using the specified base for the conversion (the default is base 10).

var may be any scalar type. You cannot use intval() on arrays or objects.

Note: The base argument for intval() has no effect unless the var argument is a string.

This function is currently not documented; only the argument list is available.

is_double

is_double -- Alias of is_float()

Description

This function is an alias of is_float().

is_float

(PHP 3, PHP 4 )

is_float -- Finds whether a variable is a float

Description

bool is_float ( mixed var)

Returns TRUE if var is a float, FALSE otherwise.

Note: To test if a variable is a number or a numeric string (such as form input, which is always a string), you must use is_numeric().

is_int

(PHP 3, PHP 4 )

is_int -- Find whether a variable is an integer

Description

bool is_int ( mixed var)

Returns TRUE if var is an integer FALSE otherwise.

Note: To test if a variable is a number or a numeric string (such as form input, which is always a string), you must use is_numeric().

is_integer

is_integer -- Alias of is_int()

Description

This function is an alias of is_int().

is_long

is_long -- Alias of is_int()

Description

This function is an alias of is_int().

is_null

(PHP 4 >= 4.0.4)

is_null -- Finds whether a variable is NULL

Description

bool is_null ( mixed var)

Returns TRUE if var is null, FALSE otherwise.

See the NULL type when a variable is considered to be NULL and when not.

is_numeric

(PHP 4 )

is_numeric -- Finds whether a variable is a number or a numeric string

Description

bool is_numeric ( mixed var)

Returns TRUE if var is a number or a numeric string, FALSE otherwise.

is_object

is_scalar() returns TRUE if the variable given by the var parameter is a scalar, otherwise it returns FALSE.

Scalar variables are those containing an integer, float, string or boolean. Types array, object and resource or not scalar.

function show_var($var) {
    if (is_scalar($var)) {
        echo $var;
    } else {
        var_dump($var);
    }
}
$pi = 3.1416;
$proteins = array("hemoglobin", "cytochrome c oxidase", "ferredoxin");

show_var($pi);
// prints: 3.1416

show_var($proteins)
// prints:
// array(3) {
//   [0]=>
//   string(10) "hemoglobin"
//   [1]=>
//   string(20) "cytochrome c oxidase"
//   [2]=>
//   string(10) "ferredoxin"
// }

Note: is_scalar() does not consider resource type values to be scalar as resources are abstract datatypes which are currently based on integers. This implementation detail should not be relied upon, as it may change.

is_string

(PHP 3, PHP 4 )

is_string -- Finds whether a variable is a string

Description

bool is_string ( mixed var)

Returns TRUE if var is a string, FALSE otherwise.

isset

(PHP 3, PHP 4 )

isset -- Determine whether a variable is set

Description

bool isset ( mixed var [, mixed var [, ...]])

Note: isset() is a language construct.

Returns TRUE if var exists; FALSE otherwise.

If a variable has been unset with unset(), it will no longer be isset(). isset() will return FALSE if testing a variable that has been set to NULL. Also note that a NULL byte ("\0") is not equivalent to the PHP NULL constant.

<?php
    $a = "test";
    $b = "anothertest";

    echo isset ($a); // TRUE
    echo isset ($a, $b); //TRUE

    unset ($a);
    echo isset ($a); // FALSE
    echo isset ($a, $b); //FALSE

$foo = NULL;
    print isset ($foo); // FALSE
?>

This also work for elements in arrays:

<?php
    $a = array ('test' => 1, 'hello' => null);

    echo isset ($a['test']);  // TRUE
    echo isset ($a['foo']);   // FALSE
    echo isset ($a['hello']); // FALSE
    echo array_key_exists('hello', $a); // TRUE
?>

print_r

(PHP 4 )

print_r -- Prints human-readable information about a variable

Description

bool print_r ( mixed expression)

print_r() displays information about a variable in a way that's readable by humans. If given a string, integer or float, the value itself will be printed. If given an array, values will be presented in a format that shows keys and elements. Similar notation is used for objects.

Remember that print_r() will move the array pointer to the end. Use reset() to bring it back to beginning.

Tip: As with anything that outputs its result directly to the browser, you can use the output-control functions to capture the output of this function, and save it in a string (for example).

<pre>
<?php
    $a = array ('a' => 'apple', 'b' => 'banana', 'c' => array ('x','y','z'));
    print_r ($a);
?>
</pre>

Which will output:
<pre> Array ( [a] => apple [b] => banana [c] => Array ( [0] => x [1] => y [2] => z ) ) </pre>

Note: Prior to PHP 4.0.4, print_r() will continue forever if given an array or object that contains a direct or indirect reference to itself. An example is print_r($GLOBALS) because $GLOBALS is itself a global variable that contains a reference to itself.

serialize

(PHP 3>= 3.0.5, PHP 4 )

serialize -- Generates a storable representation of a value

Description

string serialize ( mixed value)

serialize() returns a string containing a byte-stream representation of value that can be stored anywhere.

This is useful for storing or passing PHP values around without losing their type and structure.

To make the serialized string into a PHP value again, use unserialize(). serialize() handles all types, except the resource-type. You can even serialize() arrays that contain references to itself. References inside the array/object you are serialize()ing will also be stored.

Note: In PHP 3, object properties will be serialized, but methods are lost. PHP 4 removes that limitation and restores both properties and methods. Please see the Serializing Objects section of Classes and Objects for more information.

Example 1. serialize() example
// $session_data contains a multi-dimensional array with session // information for the current user. We use serialize() to store // it in a database at the end of the request. $conn = odbc_connect ("webdb", "php", "chicken"); $stmt = odbc_prepare ($conn, "UPDATE sessions SET data = ? WHERE id = ?"); $sqldata = array (serialize($session_data), $PHP_AUTH_USER); if (!odbc_execute ($stmt, &$sqldata)) { $stmt = odbc_prepare($conn, "INSERT INTO sessions (id, data) VALUES(?, ?)"); if (!odbc_execute($stmt, &$sqldata)) { /* Something went wrong. Bitch, whine and moan. */ } }

settype

(PHP 3, PHP 4 )

settype -- Set the type of a variable

Description

bool settype ( mixed var, string type)

Set the type of variable var to type.

Possibles values of type are:

"boolean" (or, since PHP 4.2.0, "bool")
"integer" (or, since PHP 4.2.0, "int")
"float" (only possible since PHP 4.2.0, for older versions use the deprecated variant "double")
"string"
"array"
"object"
"null" (since PHP 4.2.0)

Returns TRUE if successful; otherwise returns FALSE.

Example 1. settype() example
$foo = "5bar"; // string $bar = true; // boolean settype($foo, "integer"); // $foo is now 5 (integer) settype($bar, "string"); // $bar is now "1" (string)

See also gettype(), type-casting and type-juggling.

strval

(PHP 3, PHP 4 )

strval -- Get string value of a variable

Description

string strval ( mixed var)

Returns the string value of var. See the documentation on string for more information on converting to string.

var may be any scalar type. You cannot use strval() on arrays or objects.

unserialize

(PHP 3>= 3.0.5, PHP 4 )

unserialize -- Creates a PHP value from a stored representation

Description

mixed unserialize ( string str)

unserialize() takes a single serialized variable (see serialize()) and converts it back into a PHP value. The converted value is returned, and can be an integer, float, string, array or object. In case the passed string is not unserializeable, FALSE is returned.

Note: It's possible to set a callback-function which will be called, if an undefined class should be instanciated during unserializing. (to prevent getting an incomplete object "__PHP_Incomplete_Class".) Use your php.ini, ini_set() or .htaccess-file to define 'unserialize_callback_func'. Everytime an undefined class should be instanciated, it'll be called. To disable this feature just empty this setting.

Example 1. unserialize_callback_func example
$serialized_object='O:1:"a":1:{s:5:"value";s:3:"100";}'; ini_set('unserialize_callback_func','mycallback'); // set your callback_function function mycallback($classname) { // just include a file containing your classdefinition // you get $classname to figure out which classdefinition is required }

Note: In PHP 3, methods are not preserved when unserializing a serialized object. PHP 4 removes that limitation and restores both properties and methods. Please see the Serializing Objects section of Classes and Objects or more information.

Example 2. unserialize() example
// Here, we use unserialize() to load session data to the // $session_data array from the string selected from a database. // This example complements the one described with serialize(). $conn = odbc_connect ("webdb", "php", "chicken"); $stmt = odbc_prepare ($conn, "SELECT data FROM sessions WHERE id = ?"); $sqldata = array ($PHP_AUTH_USER); if (!odbc_execute ($stmt, &$sqldata) || !odbc_fetch_into ($stmt, &$tmp)) { // if the execute or fetch fails, initialize to empty array $session_data = array(); } else { // we should now have the serialized data in $tmp[0]. $session_data = unserialize ($tmp[0]); if (!is_array ($session_data)) { // something went wrong, initialize to empty array $session_data = array(); } }

unset

(PHP 3, PHP 4 )

unset -- Unset a given variable

Description

void unset ( mixed var [, mixed var [, ...]])

Note: unset() is a language construct.

unset() destroys the specified variables. Note that in PHP 3, unset() will always return TRUE (actually, the integer value 1). In PHP 4, however, unset() is no longer a true function: it is now a statement. As such no value is returned, and attempting to take the value of unset() results in a parse error.

Example 1. unset() example
// destroy a single variable unset ($foo); // destroy a single element of an array unset ($bar['quux']); // destroy more than one variable unset ($foo1, $foo2, $foo3);

The behavior of unset() inside of a function can vary depending on what type of variable you are attempting to destroy.

If a globalized variable is unset() inside of a function, only the local variable is destroyed. The variable in the calling environment will retain the same value as before unset() was called.

function destroy_foo() {
    global $foo;
    unset($foo);
}

$foo = 'bar';
destroy_foo();
echo $foo;

The above example would output:

bar

If a variable that is PASSED BY REFERENCE is unset() inside of a function, only the local variable is destroyed. The variable in the calling environment will retain the same value as before unset() was called.

function foo(&$bar) {
    unset($bar);
    $bar = "blah";
}

$bar = 'something';
echo "$bar\n";

foo($bar);
echo "$bar\n";

The above example would output:

something
something

If a static variable is unset() inside of a function, unset() destroyes the variable and all its references.

function foo() {
    static $a;
    $a++;
    echo "$a\n";
    unset($a);
}

foo();
foo();
foo();

The above example would output:

1
2
3

If you would like to unset() a global variable inside of a function, you can use the $GLOBALS array to do so:

function foo() {
    unset($GLOBALS['bar']);
}

$bar = "something";
foo();

var_dump

(PHP 3>= 3.0.5, PHP 4 )

var_dump -- Dumps information about a variable

Description

void var_dump ( mixed expression [, mixed expression [, ...]])

This function returns structured information about one or more expressions that includes its type and value. Arrays are explored recursively with values indented to show structure.

Tip: As with anything that outputs its result directly to the browser, you can use the output-control functions to capture the output of this function, and save it in a string (for example).

Compare var_dump() to print_r().

<pre>
<?php
$a = array (1, 2, array ("a", "b", "c"));
var_dump ($a);

/* output:
array(3) {
  [0]=>
  int(1)
  [1]=>
  int(2)
  [2]=>
  array(3) {
    [0]=>
    string(1) "a"
    [1]=>
    string(1) "b"
    [2]=>
    string(1) "c"
  }
}

*/

$b = 3.1;
$c = TRUE;
var_dump($b,$c);

/* output:
float(3.1)
bool(true)

*/
?>
</pre>

var_export

(PHP 4 >= 4.2.0)

var_export -- Outputs or returns a string representation of a variable

Description

mixed var_export ( mixed expression [, bool return])

This function returns structured information about the variable that is passed to this function. It is similar to var_dump() with the exception that the returned representation is valid PHP code.

You can also return the variable representation by using TRUE as second parameter to this function.

Compare var_export() to var_dump().

<pre>
<?php
$a = array (1, 2, array ("a", "b", "c"));
var_export ($a);

/* output:
array (
  0 => 1,
  1 => 2,
  2 => 
  array (
    0 => 'a',
    1 => 'b',
    2 => 'c',
  ),
)
*/

$b = 3.1;
$v = var_export($b, TRUE);
echo $v;

/* output:
3.1
*/
?>
</pre>

CIII. vpopmail functions

Introduction

Warning

Table of Contents
vpopmail_add_alias_domain_ex -- Add alias to an existing virtual domain
vpopmail_add_alias_domain -- Add an alias for a virtual domain
vpopmail_add_domain_ex -- Add a new virtual domain
vpopmail_add_domain -- Add a new virtual domain
vpopmail_add_user -- Add a new user to the specified virtual domain
vpopmail_alias_add -- insert a virtual alias
vpopmail_alias_del_domain -- deletes all virtual aliases of a domain
vpopmail_alias_del -- deletes all virtual aliases of a user
vpopmail_alias_get_all -- get all lines of an alias for a domain
vpopmail_alias_get -- get all lines of an alias for a domain
vpopmail_auth_user -- Attempt to validate a username/domain/password. Returns true/false
vpopmail_del_domain_ex -- Delete a virtual domain
vpopmail_del_domain -- Delete a virtual domain
vpopmail_del_user -- Delete a user from a virtual domain
vpopmail_error -- Get text message for last vpopmail error. Returns string
vpopmail_passwd -- Change a virtual user's password
vpopmail_set_user_quota -- Sets a virtual user's quota

CIV. W32api functions

Introduction

This extension is a generic extension API to DLLs. This was originally written to allow access to the Win32 API from PHP, although you can also access other functions exported via other DLLs.

Currently supported types are generic PHP types (strings, booleans, floats, integers and nulls) and types you define with w32api_deftype().

Warning

Requirements

This extension will only work on Windows systems.

Installation

There is no installation needed to use these functions; they are part of the PHP core.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension defines one resource type, used for user defined types. The name of this resource is "dynaparm".

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

DC_MICROSOFT (integer)
DC_BORLAND (integer)
DC_CALL_CDECL (integer)
DC_CALL_STD (integer)
DC_RETVAL_MATH4 (integer)
DC_RETVAL_MATH8 (integer)
DC_CALL_STD_BO (integer)
DC_CALL_STD_MS (integer)
DC_CALL_STD_M8 (integer)
DC_FLAG_ARGPTR (integer)

Examples

This example gets the amount of time the system has been running and displays it in a message box.

Example 1. Get the uptime and display it in a message box

<?php
// Define constants needed, taken from
// Visual Studio/Tools/Winapi/WIN32API.txt
define("MB_OK", 0);

// Load the extension in
dl("php_w32api.dll");

// Register the GetTickCount function from kernel32.dll
w32api_register_function("kernel32.dll", 
                         "GetTickCount",
                         "long");
                         
// Register the MessageBoxA function from User32.dll
w32api_register_function("User32.dll",
                         "MessageBoxA",
                         "long");

// Get uptime information
$ticks = GetTickCount();

// Convert it to a nicely displayable text
$secs  = floor($ticks / 1000);
$mins  = floor($secs / 60);
$hours = floor($mins / 60);

$str = sprintf("You have been using your computer for:".
                "\r\n %d Milliseconds, or \r\n %d Seconds".
                "or \r\n %d mins or\r\n %d hours %d mins.",
                $ticks,
                $secs,
                $mins,
                $hours,
                $mins - ($hours*60));

// Display a message box with only an OK button and the uptime text
MessageBoxA(NULL, 
            $str, 
            "Uptime Information", 
            MB_OK);
?>

Table of Contents
w32api_deftype -- Defines a type for use with other w32api_functions
w32api_init_dtype -- Creates an instance of the data type typename and fills it with the values passed
w32api_invoke_function -- Invokes function funcname with the arguments passed after the function name
w32api_register_function -- Registers function function_name from library with PHP
w32api_set_call_method -- Sets the calling method used

CV. WDDX Functions

Introduction

These functions are intended for work with WDDX.

Requirements

In order to use WDDX, you will need to install the expat library (which comes with Apache 1.3.7 or higher).

Installation

After installing expat compile PHP with --with-xml and --enable-wddx.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Examples

All the functions that serialize variables use the first element of an array to determine whether the array is to be serialized into an array or structure. If the first element has string key, then it is serialized into a structure, otherwise, into an array.
Example 1. Serializing a single value
<?php print wddx_serialize_value("PHP to WDDX packet example", "PHP packet"); ?>

This example will produce:

<wddxPacket version='1.0'><header comment='PHP packet'/><data>
<string>PHP to WDDX packet example</string></data></wddxPacket>

Example 2. Using incremental packets

<?php
$pi = 3.1415926;
$packet_id = wddx_packet_start("PHP");
wddx_add_vars($packet_id, "pi");

/* Suppose $cities came from database */
$cities = array("Austin", "Novato", "Seattle");
wddx_add_vars($packet_id, "cities");

$packet = wddx_packet_end($packet_id);
print $packet;
?>

This example will produce:

<wddxPacket version='1.0'><header comment='PHP'/><data><struct>
<var name='pi'><number>3.1415926</number></var><var name='cities'>
<array length='3'><string>Austin</string><string>Novato</string>
<string>Seattle</string></array></var></struct></data></wddxPacket>

Note: If you want to serialize non-ASCII characters you have to set the appropriate locale before doing so (see setlocale()).

Table of Contents
wddx_add_vars -- Add variables to a WDDX packet with the specified ID
wddx_deserialize -- Deserializes a WDDX packet
wddx_packet_end -- Ends a WDDX packet with the specified ID
wddx_packet_start -- Starts a new WDDX packet with structure inside it
wddx_serialize_value -- Serialize a single value into a WDDX packet
wddx_serialize_vars -- Serialize variables into a WDDX packet

wddx_serialize_vars() takes a variable number of arguments, each of which can be either a string naming a variable or an array containing strings naming the variables or another array, etc.

Example 1. wddx_serialize_vars() example
<?php $a = 1; $b = 5.5; $c = array("blue", "orange", "violet"); $d = "colors"; $clvars = array("c", "d"); print wddx_serialize_vars("a", "b", $clvars); ?>

The above example will produce:
<wddxPacket version='1.0'><header/><data><struct><var name='a'><number>1</number></var> <var name='b'><number>5.5</number></var><var name='c'><array length='3'> <string>blue</string><string>orange</string><string>violet</string></array></var> <var name='d'><string>colors</string></var></struct></data></wddxPacket>

CVI. XML parser functions

Introduction

XML (eXtensible Markup Language) is a data format for structured document interchange on the Web. It is a standard defined by The World Wide Web consortium (W3C). Information about XML and related technologies can be found at http://www.w3.org/XML/.

This PHP extension implements support for James Clark's expat in PHP. This toolkit lets you parse, but not validate, XML documents. It supports three source character encodings also provided by PHP: US-ASCII, ISO-8859-1 and UTF-8. UTF-16 is not supported.

This extension lets you create XML parsers and then define handlers for different XML events. Each XML parser also has a few parameters you can adjust.

Requirements

This extension uses expat, which can be found at http://www.jclark.com/xml/. The Makefile that comes with expat does not build a library by default, you can use this make rule for that:
libexpat.a: $(OBJS) ar -rc $@ $(OBJS) ranlib $@
A source RPM package of expat can be found at http://sourceforge.net/projects/expat/.

Installation

If you are using Apache-1.3.7 or later, you already have the required expat library. Simply configure PHP using --with-xml (without any additional path) and it will automatically use the expat library built into Apache.

On UNIX, run configure with the --with-xml option. The expat library should be installed somewhere your compiler can find it. If you compile PHP as a module for Apache 1.3.9 or later, PHP will automatically use the bundled expat library from Apache. You may need to set CPPFLAGS and LDFLAGS in your environment before running configure if you have installed expat somewhere exotic.

Build PHP. Tada! That should be it.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

XML_ERROR_NONE (integer)
XML_ERROR_NO_MEMORY (integer)
XML_ERROR_SYNTAX (integer)
XML_ERROR_NO_ELEMENTS (integer)
XML_ERROR_INVALID_TOKEN (integer)
XML_ERROR_UNCLOSED_TOKEN (integer)
XML_ERROR_PARTIAL_CHAR (integer)
XML_ERROR_TAG_MISMATCH (integer)
XML_ERROR_DUPLICATE_ATTRIBUTE (integer)
XML_ERROR_JUNK_AFTER_DOC_ELEMENT (integer)
XML_ERROR_PARAM_ENTITY_REF (integer)
XML_ERROR_UNDEFINED_ENTITY (integer)
XML_ERROR_RECURSIVE_ENTITY_REF (integer)
XML_ERROR_ASYNC_ENTITY (integer)
XML_ERROR_BAD_CHAR_REF (integer)
XML_ERROR_BINARY_ENTITY_REF (integer)
XML_ERROR_ATTRIBUTE_EXTERNAL_ENTITY_REF (integer)
XML_ERROR_MISPLACED_XML_PI (integer)
XML_ERROR_UNKNOWN_ENCODING (integer)
XML_ERROR_INCORRECT_ENCODING (integer)
XML_ERROR_UNCLOSED_CDATA_SECTION (integer)
XML_ERROR_EXTERNAL_ENTITY_HANDLING (integer)
XML_OPTION_CASE_FOLDING (integer)
XML_OPTION_TARGET_ENCODING (integer)
XML_OPTION_SKIP_TAGSTART (integer)
XML_OPTION_SKIP_WHITE (integer)

Event Handlers

The XML event handlers defined are:

Table 1. Supported XML handlers

PHP function to set handler	Event description
xml_set_element_handler()	Element events are issued whenever the XML parser encounters start or end tags. There are separate handlers for start tags and end tags.
xml_set_character_data_handler()	Character data is roughly all the non-markup contents of XML documents, including whitespace between tags. Note that the XML parser does not add or remove any whitespace, it is up to the application (you) to decide whether whitespace is significant.
xml_set_processing_instruction_handler()	PHP programmers should be familiar with processing instructions (PIs) already. <?php ?> is a processing instruction, where `php` is called the "PI target". The handling of these are application-specific, except that all PI targets starting with "XML" are reserved.
xml_set_default_handler()	What goes not to another handler goes to the default handler. You will get things like the XML and document type declarations in the default handler.
xml_set_unparsed_entity_decl_handler()	This handler will be called for declaration of an unparsed (NDATA) entity.
xml_set_notation_decl_handler()	This handler is called for declaration of a notation.
xml_set_external_entity_ref_handler()	This handler is called when the XML parser finds a reference to an external parsed general entity. This can be a reference to a file or URL, for example. See the external entity example for a demonstration.

Case Folding

The element handler functions may get their element names case-folded. Case-folding is defined by the XML standard as "a process applied to a sequence of characters, in which those identified as non-uppercase are replaced by their uppercase equivalents". In other words, when it comes to XML, case-folding simply means uppercasing.

By default, all the element names that are passed to the handler functions are case-folded. This behaviour can be queried and controlled per XML parser with the xml_parser_get_option() and xml_parser_set_option() functions, respectively.

Error Codes

The following constants are defined for XML error codes (as returned by xml_parse()):

XML_ERROR_NONE

XML_ERROR_NO_MEMORY

XML_ERROR_SYNTAX

XML_ERROR_NO_ELEMENTS

XML_ERROR_INVALID_TOKEN

XML_ERROR_UNCLOSED_TOKEN

XML_ERROR_PARTIAL_CHAR

XML_ERROR_TAG_MISMATCH

XML_ERROR_DUPLICATE_ATTRIBUTE

XML_ERROR_JUNK_AFTER_DOC_ELEMENT

XML_ERROR_PARAM_ENTITY_REF

XML_ERROR_UNDEFINED_ENTITY

XML_ERROR_RECURSIVE_ENTITY_REF

XML_ERROR_ASYNC_ENTITY

XML_ERROR_BAD_CHAR_REF

XML_ERROR_BINARY_ENTITY_REF

XML_ERROR_ATTRIBUTE_EXTERNAL_ENTITY_REF

XML_ERROR_MISPLACED_XML_PI

XML_ERROR_UNKNOWN_ENCODING

XML_ERROR_INCORRECT_ENCODING

XML_ERROR_UNCLOSED_CDATA_SECTION

XML_ERROR_EXTERNAL_ENTITY_HANDLING

Character Encoding

PHP's XML extension supports the Unicode character set through different character encodings. There are two types of character encodings, source encoding and target encoding. PHP's internal representation of the document is always encoded with UTF-8.

Source encoding is done when an XML document is parsed. Upon creating an XML parser, a source encoding can be specified (this encoding can not be changed later in the XML parser's lifetime). The supported source encodings are ISO-8859-1, US-ASCII and UTF-8. The former two are single-byte encodings, which means that each character is represented by a single byte. UTF-8 can encode characters composed by a variable number of bits (up to 21) in one to four bytes. The default source encoding used by PHP is ISO-8859-1.

Target encoding is done when PHP passes data to XML handler functions. When an XML parser is created, the target encoding is set to the same as the source encoding, but this may be changed at any point. The target encoding will affect character data as well as tag names and processing instruction targets.

If the XML parser encounters characters outside the range that its source encoding is capable of representing, it will return an error.

If PHP encounters characters in the parsed XML document that can not be represented in the chosen target encoding, the problem characters will be "demoted". Currently, this means that such characters are replaced by a question mark.

Examples

Here are some example PHP scripts parsing XML documents.

XML Element Structure Example

This first example displays the stucture of the start elements in a document with indentation.
Example 1. Show XML Element Structure
$file = "data.xml"; $depth = array(); function startElement($parser, $name, $attrs) { global $depth; for ($i = 0; $i < $depth[$parser]; $i++) { print " "; } print "$name\n"; $depth[$parser]++; } function endElement($parser, $name) { global $depth; $depth[$parser]--; } $xml_parser = xml_parser_create(); xml_set_element_handler($xml_parser, "startElement", "endElement"); if (!($fp = fopen($file, "r"))) { die("could not open XML input"); } while ($data = fread($fp, 4096)) { if (!xml_parse($xml_parser, $data, feof($fp))) { die(sprintf("XML error: %s at line %d", xml_error_string(xml_get_error_code($xml_parser)), xml_get_current_line_number($xml_parser))); } } xml_parser_free($xml_parser);

XML Tag Mapping Example

Example 2. Map XML to HTML
This example maps tags in an XML document directly to HTML tags. Elements not found in the "map array" are ignored. Of course, this example will only work with a specific XML document type.
$file = "data.xml"; $map_array = array( "BOLD" => "B", "EMPHASIS" => "I", "LITERAL" => "TT" ); function startElement($parser, $name, $attrs) { global $map_array; if ($htmltag = $map_array[$name]) { print "<$htmltag>"; } } function endElement($parser, $name) { global $map_array; if ($htmltag = $map_array[$name]) { print "</$htmltag>"; } } function characterData($parser, $data) { print $data; } $xml_parser = xml_parser_create(); // use case-folding so we are sure to find the tag in $map_array xml_parser_set_option($xml_parser, XML_OPTION_CASE_FOLDING, true); xml_set_element_handler($xml_parser, "startElement", "endElement"); xml_set_character_data_handler($xml_parser, "characterData"); if (!($fp = fopen($file, "r"))) { die("could not open XML input"); } while ($data = fread($fp, 4096)) { if (!xml_parse($xml_parser, $data, feof($fp))) { die(sprintf("XML error: %s at line %d", xml_error_string(xml_get_error_code($xml_parser)), xml_get_current_line_number($xml_parser))); } } xml_parser_free($xml_parser);

XML External Entity Example

This example highlights XML code. It illustrates how to use an external entity reference handler to include and parse other documents, as well as how PIs can be processed, and a way of determining "trust" for PIs containing code.

XML documents that can be used for this example are found below the example (xmltest.xml and xmltest2.xml.)

Example 3. External Entity Example
<?php $file = "xmltest.xml"; function trustedFile($file) { // only trust local files owned by ourselves if (!eregi("^([a-z]+)://", $file) && fileowner($file) == getmyuid()) { return true; } return false; } function startElement($parser, $name, $attribs) { print "<<font color=\"#0000cc\">$name</font>"; if (sizeof($attribs)) { while (list($k, $v) = each($attribs)) { print " <font color=\"#009900\">$k</font>=\"<font color=\"#990000\">$v</font>\""; } } print ">"; } function endElement($parser, $name) { print "</<font color=\"#0000cc\">$name</font>>"; } function characterData($parser, $data) { print "<b>$data</b>"; } function PIHandler($parser, $target, $data) { switch (strtolower($target)) { case "php": global $parser_file; // If the parsed document is "trusted", we say it is safe // to execute PHP code inside it. If not, display the code // instead. if (trustedFile($parser_file[$parser])) { eval($data); } else { printf("Untrusted PHP code: <i>%s</i>", htmlspecialchars($data)); } break; } } function defaultHandler($parser, $data) { if (substr($data, 0, 1) == "&" && substr($data, -1, 1) == ";") { printf('<font color="#aa00aa">%s</font>', htmlspecialchars($data)); } else { printf('<font size="-1">%s</font>', htmlspecialchars($data)); } } function externalEntityRefHandler($parser, $openEntityNames, $base, $systemId, $publicId) { if ($systemId) { if (!list($parser, $fp) = new_xml_parser($systemId)) { printf("Could not open entity %s at %s\n", $openEntityNames, $systemId); return false; } while ($data = fread($fp, 4096)) { if (!xml_parse($parser, $data, feof($fp))) { printf("XML error: %s at line %d while parsing entity %s\n", xml_error_string(xml_get_error_code($parser)), xml_get_current_line_number($parser), $openEntityNames); xml_parser_free($parser); return false; } } xml_parser_free($parser); return true; } return false; } function new_xml_parser($file) { global $parser_file; $xml_parser = xml_parser_create(); xml_parser_set_option($xml_parser, XML_OPTION_CASE_FOLDING, 1); xml_set_element_handler($xml_parser, "startElement", "endElement"); xml_set_character_data_handler($xml_parser, "characterData"); xml_set_processing_instruction_handler($xml_parser, "PIHandler"); xml_set_default_handler($xml_parser, "defaultHandler"); xml_set_external_entity_ref_handler($xml_parser, "externalEntityRefHandler"); if (!($fp = @fopen($file, "r"))) { return false; } if (!is_array($parser_file)) { settype($parser_file, "array"); } $parser_file[$xml_parser] = $file; return array($xml_parser, $fp); } if (!(list($xml_parser, $fp) = new_xml_parser($file))) { die("could not open XML input"); } print "<pre>"; while ($data = fread($fp, 4096)) { if (!xml_parse($xml_parser, $data, feof($fp))) { die(sprintf("XML error: %s at line %d\n", xml_error_string(xml_get_error_code($xml_parser)), xml_get_current_line_number($xml_parser))); } } print "</pre>"; print "parse complete\n"; xml_parser_free($xml_parser); ?>

Example 4. xmltest.xml
<?xml version='1.0'?> <!DOCTYPE chapter SYSTEM "/just/a/test.dtd" [ <!ENTITY plainEntity "FOO entity"> <!ENTITY systemEntity SYSTEM "xmltest2.xml"> ]> <chapter> <TITLE>Title &plainEntity;</TITLE> <para> <informaltable> <tgroup cols="3"> <tbody> <row><entry>a1</entry><entry morerows="1">b1</entry><entry>c1</entry></row> <row><entry>a2</entry><entry>c2</entry></row> <row><entry>a3</entry><entry>b3</entry><entry>c3</entry></row> </tbody> </tgroup> </informaltable> </para> &systemEntity; <section id="about"> <title>About this Document</title> <para>  <?php print 'Hi! This is PHP version '.phpversion(); ?> </para> </section> </chapter>

This file is included from xmltest.xml:
Example 5. xmltest2.xml
<?xml version="1.0"?> <!DOCTYPE foo [ <!ENTITY testEnt "test entity"> ]> <foo> <element attrib="value"/> &testEnt; <?php print "This is some more PHP code being executed."; ?> </foo>

Table of Contents
utf8_decode -- Converts a string with ISO-8859-1 characters encoded with UTF-8 to single-byte ISO-8859-1.
utf8_encode -- encodes an ISO-8859-1 string to UTF-8
xml_error_string -- get XML parser error string
xml_get_current_byte_index -- get current byte index for an XML parser
xml_get_current_column_number -- Get current column number for an XML parser
xml_get_current_line_number -- get current line number for an XML parser
xml_get_error_code -- get XML parser error code
xml_parse_into_struct -- Parse XML data into an array structure
xml_parse -- start parsing an XML document
xml_parser_create_ns -- Create an XML parser
xml_parser_create -- create an XML parser
xml_parser_free -- Free an XML parser
xml_parser_get_option -- get options from an XML parser
xml_parser_set_option -- set options in an XML parser
xml_set_character_data_handler -- set up character data handler
xml_set_default_handler -- set up default handler
xml_set_element_handler -- set up start and end element handlers
xml_set_end_namespace_decl_handler -- Set up character data handler
xml_set_external_entity_ref_handler -- set up external entity reference handler
xml_set_notation_decl_handler -- set up notation declaration handler
xml_set_object -- Use XML Parser within an object
xml_set_processing_instruction_handler -- Set up processing instruction (PI) handler
xml_set_start_namespace_decl_handler -- Set up character data handler
xml_set_unparsed_entity_decl_handler -- Set up unparsed entity declaration handler

utf8_decode

(PHP 3>= 3.0.6, PHP 4 )

utf8_decode -- Converts a string with ISO-8859-1 characters encoded with UTF-8 to single-byte ISO-8859-1.

Description

string utf8_decode ( string data)

This function decodes data, assumed to be UTF-8 encoded, to ISO-8859-1.

See utf8_encode() for an explaination of UTF-8 encoding.

utf8_encode

(PHP 3>= 3.0.6, PHP 4 )

utf8_encode -- encodes an ISO-8859-1 string to UTF-8

Description

string utf8_encode ( string data)

This function encodes the string data to UTF-8, and returns the encoded version. UTF-8 is a standard mechanism used by Unicode for encoding wide character values into a byte stream. UTF-8 is transparent to plain ASCII characters, is self-synchronized (meaning it is possible for a program to figure out where in the bytestream characters start) and can be used with normal string comparison functions for sorting and such. PHP encodes UTF-8 characters in up to four bytes, like this:

Table 1. UTF-8 encoding

bytes	bits	representation
1	7	0bbbbbbb
2	11	110bbbbb 10bbbbbb
3	16	1110bbbb 10bbbbbb 10bbbbbb
4	21	11110bbb 10bbbbbb 10bbbbbb 10bbbbbb

Each b represents a bit that can be used to store character data.

xml_error_string

(PHP 3>= 3.0.6, PHP 4 )

xml_error_string -- get XML parser error string

Description

string xml_error_string ( int code)

code: An error code from xml_get_error_code().

Returns a string with a textual description of the error code code, or FALSE if no description was found.

xml_get_current_byte_index

(PHP 3>= 3.0.6, PHP 4 )

xml_get_current_byte_index -- get current byte index for an XML parser

Description

int xml_get_current_byte_index ( resource parser)

parser: A reference to the XML parser to get byte index from.

This function returns FALSE if parser does not refer to a valid parser, or else it returns which byte index the parser is currently at in its data buffer (starting at 0).

xml_get_current_column_number

(PHP 3>= 3.0.6, PHP 4 )

xml_get_current_column_number -- Get current column number for an XML parser

Description

int xml_get_current_column_number ( resource parser)

parser: A reference to the XML parser to get column number from.

This function returns FALSE if parser does not refer to a valid parser, or else it returns which column on the current line (as given by xml_get_current_line_number()) the parser is currently at.

xml_get_current_line_number

(PHP 3>= 3.0.6, PHP 4 )

xml_get_current_line_number -- get current line number for an XML parser

Description

int xml_get_current_line_number ( resource parser)

parser: A reference to the XML parser to get line number from.

This function returns FALSE if parser does not refer to a valid parser, or else it returns which line the parser is currently at in its data buffer.

xml_get_error_code

(PHP 3>= 3.0.6, PHP 4 )

xml_get_error_code -- get XML parser error code

Description

int xml_get_error_code ( resource parser)

parser: A reference to the XML parser to get error code from.

This function returns FALSE if parser does not refer to a valid parser, or else it returns one of the error codes listed in the error codes section.

xml_parse_into_struct

(PHP 3>= 3.0.8, PHP 4 )

xml_parse_into_struct -- Parse XML data into an array structure

Description

int xml_parse_into_struct ( resource parser, string data, array &values, array &index)

This function parses an XML file into 2 parallel array structures, one (index) containing pointers to the location of the appropriate values in the values array. These last two parameters must be passed by reference.

Below is an example that illustrates the internal structure of the arrays being generated by the function. We use a simple note tag embeded inside a para tag, and then we parse this an print out the structures generated:

$simple = "<para><note>simple note</note></para>";
$p = xml_parser_create();
xml_parse_into_struct($p,$simple,$vals,$index);
xml_parser_free($p);
echo "Index array\n";
print_r($index);
echo "\nVals array\n";
print_r($vals);

When we run that code, the output will be:

Index array
Array
(
    [PARA] => Array
        (
            [0] => 0
            [1] => 2
        )

    [NOTE] => Array
        (
            [0] => 1
        )

)

Vals array
Array
(
    [0] => Array
        (
            [tag] => PARA
            [type] => open
            [level] => 1
        )

    [1] => Array
        (
            [tag] => NOTE
            [type] => complete
            [level] => 2
            [value] => simple note
        )

    [2] => Array
        (
            [tag] => PARA
            [type] => close
            [level] => 1
        )

)

Event-driven parsing (based on the expat library) can get complicated when you have an XML document that is complex. This function does not produce a DOM style object, but it generates structures amenable of being transversed in a tree fashion. Thus, we can create objects representing the data in the XML file easily. Let's consider the following XML file representing a small database of aminoacids information:
Example 1. moldb.xml - small database of molecular information
<?xml version="1.0"?> <moldb> <molecule> <name>Alanine</name> <symbol>ala</symbol> <code>A</code> <type>hydrophobic</type> </molecule> <molecule> <name>Lysine</name> <symbol>lys</symbol> <code>K</code> <type>charged</type> </molecule> </moldb>
And some code to parse the document and generate the appropriate objects:
Example 2. parsemoldb.php - parses moldb.xml into and array of molecular objects
<?php class AminoAcid { var $name; // aa name var $symbol; // three letter symbol var $code; // one letter code var $type; // hydrophobic, charged or neutral function AminoAcid ($aa) { foreach ($aa as $k=>$v) $this->$k = $aa[$k]; } } function readDatabase($filename) { // read the xml database of aminoacids $data = implode("",file($filename)); $parser = xml_parser_create(); xml_parser_set_option($parser,XML_OPTION_CASE_FOLDING,0); xml_parser_set_option($parser,XML_OPTION_SKIP_WHITE,1); xml_parse_into_struct($parser,$data,$values,$tags); xml_parser_free($parser); // loop through the structures foreach ($tags as $key=>$val) { if ($key == "molecule") { $molranges = $val; // each contiguous pair of array entries are the // lower and upper range for each molecule definition for ($i=0; $i < count($molranges); $i+=2) { $offset = $molranges[$i] + 1; $len = $molranges[$i + 1] - $offset; $tdb[] = parseMol(array_slice($values, $offset, $len)); } } else { continue; } } return $tdb; } function parseMol($mvalues) { for ($i=0; $i < count($mvalues); $i++) $mol[$mvalues[$i]["tag"]] = $mvalues[$i]["value"]; return new AminoAcid($mol); } $db = readDatabase("moldb.xml"); echo "** Database of AminoAcid objects:\n"; print_r($db); ?>
After executing parsemoldb.php, the variable $db contains an array of AminoAcid objects, and the output of the script confirms that:

** Database of AminoAcid objects:
Array
(
    [0] => aminoacid Object
        (
            [name] => Alanine
            [symbol] => ala
            [code] => A
            [type] => hydrophobic
        )

    [1] => aminoacid Object
        (
            [name] => Lysine
            [symbol] => lys
            [code] => K
            [type] => charged
        )

)

xml_parse

(PHP 3>= 3.0.6, PHP 4 )

xml_parse -- start parsing an XML document

Description

bool xml_parse ( resource parser, string data [, bool is_final])

parser: A reference to the XML parser to use.
data: Chunk of data to parse. A document may be parsed piece-wise by calling xml_parse() several times with new data, as long as the is_final parameter is set and TRUE when the last data is parsed.
is_final (optional): If set and TRUE, data is the last piece of data sent in this parse.

When the XML document is parsed, the handlers for the configured events are called as many times as necessary, after which this function returns TRUE or FALSE.

TRUE is returned if the parse was successful, FALSE if it was not successful, or if parser does not refer to a valid parser. For unsuccessful parses, error information can be retrieved with xml_get_error_code(), xml_error_string(), xml_get_current_line_number(), xml_get_current_column_number() and xml_get_current_byte_index().

xml_parser_create_ns

(PHP 4 >= 4.0.5)

xml_parser_create_ns -- Create an XML parser

Description

resource xml_parser_create_ns ( [string encoding [, string sep]])

Warning

This function is currently not documented; only the argument list is available.

xml_parser_create

(PHP 3>= 3.0.6, PHP 4 )

xml_parser_create -- create an XML parser

Description

resource xml_parser_create ( [string encoding])

encoding (optional)

Which character encoding the parser should use. The following character encodings are supported:

ISO-8859-1 (default)

US-ASCII

UTF-8

This function creates an XML parser and returns a handle for use by other XML functions. Returns FALSE on failure.

xml_parser_free

(PHP 3>= 3.0.6, PHP 4 )

xml_parser_free -- Free an XML parser

Description

bool xml_parser_free ( resource parser)

parser: A reference to the XML parser to free.

This function returns FALSE if parser does not refer to a valid parser, or else it frees the parser and returns TRUE.

xml_parser_get_option

(PHP 3>= 3.0.6, PHP 4 )

xml_parser_get_option -- get options from an XML parser

Description

mixed xml_parser_get_option ( resource parser, int option)

parser: A reference to the XML parser to get an option from.
option: Which option to fetch. See xml_parser_set_option() for a list of options.

This function returns FALSE if parser does not refer to a valid parser, or if the option could not be set. Else the option's value is returned.

See xml_parser_set_option() for the list of options.

xml_parser_set_option

(PHP 3>= 3.0.6, PHP 4 )

xml_parser_set_option -- set options in an XML parser

Description

bool xml_parser_set_option ( resource parser, int option, mixed value)

parser: A reference to the XML parser to set an option in.
option: Which option to set. See below.
value: The option's new value.

This function returns FALSE if parser does not refer to a valid parser, or if the option could not be set. Else the option is set and TRUE is returned.

The following options are available:

Table 1. XML parser options

Option constant	Data type	Description
XML_OPTION_CASE_FOLDING	integer	Controls whether case-folding is enabled for this XML parser. Enabled by default.
XML_OPTION_TARGET_ENCODING	string	Sets which target encoding to use in this XML parser. By default, it is set to the same as the source encoding used by xml_parser_create(). Supported target encodings are `ISO-8859-1`, `US-ASCII` and `UTF-8`.

xml_set_character_data_handler

(PHP 3>= 3.0.6, PHP 4 )

xml_set_character_data_handler -- set up character data handler

Description

bool xml_set_character_data_handler ( resource parser, string handler)

Sets the character data handler function for the XML parser parser. handler is a string containing the name of a function that must exist when xml_parse() is called for parser.

The function named by handler must accept two parameters: handler ( resource parser, string data)

parser: The first parameter, parser, is a reference to the XML parser calling the handler.
data: The second parameter, data, contains the character data as a string.

If a handler function is set to an empty string, or FALSE, the handler in question is disabled.

TRUE is returned if the handler is set up, FALSE if parser is not a parser.

Note: Instead of a function name, an array containing an object reference and a method name can also be supplied.

xml_set_default_handler

(PHP 3>= 3.0.6, PHP 4 )

xml_set_default_handler -- set up default handler

Description

bool xml_set_default_handler ( resource parser, string handler)

Sets the default handler function for the XML parser parser. handler is a string containing the name of a function that must exist when xml_parse() is called for parser.

The function named by handler must accept two parameters: handler ( resource parser, string data)

parser: The first parameter, parser, is a reference to the XML parser calling the handler.
data: The second parameter, data, contains the character data. This may be the XML declaration, document type declaration, entities or other data for which no other handler exists.

If a handler function is set to an empty string, or FALSE, the handler in question is disabled.

TRUE is returned if the handler is set up, FALSE if parser is not a parser.

Note: Instead of a function name, an array containing an object reference and a method name can also be supplied.

xml_set_element_handler

(PHP 3>= 3.0.6, PHP 4 )

xml_set_element_handler -- set up start and end element handlers

Description

bool xml_set_element_handler ( resource parser, string start_element_handler, string end_element_handler)

Sets the element handler functions for the XML parser parser. start_element_handler and end_element_handler are strings containing the names of functions that must exist when xml_parse() is called for parser.

The function named by start_element_handler must accept three parameters: start_element_handler ( resource parser, string name, array attribs)

parser

The first parameter, parser, is a reference to the XML parser calling the handler.

name

The second parameter, name, contains the name of the element for which this handler is called. If case-folding is in effect for this parser, the element name will be in uppercase letters.

attribs

The third parameter, attribs, contains an associative array with the element's attributes (if any). The keys of this array are the attribute names, the values are the attribute values. Attribute names are case-folded on the same criteria as element names. Attribute values are not case-folded.

The original order of the attributes can be retrieved by walking through attribs the normal way, using each(). The first key in the array was the first attribute, and so on.

The function named by end_element_handler must accept two parameters: end_element_handler ( resource parser, string name)

parser: The first parameter, parser, is a reference to the XML parser calling the handler.
name: The second parameter, name, contains the name of the element for which this handler is called. If case-folding is in effect for this parser, the element name will be in uppercase letters.

If a handler function is set to an empty string, or FALSE, the handler in question is disabled.

TRUE is returned if the handlers are set up, FALSE if parser is not a parser.

Note: Instead of a function name, an array containing an object reference and a method name can also be supplied.

xml_set_end_namespace_decl_handler

(PHP 4 >= 4.0.5)

xml_set_end_namespace_decl_handler -- Set up character data handler

Description

bool xml_set_end_namespace_decl_handler ( resource pind, string hdl)

Warning

This function is currently not documented; only the argument list is available.

Note: Instead of a function name, an array containing an object reference and a method name can also be supplied.

xml_set_external_entity_ref_handler

(PHP 3>= 3.0.6, PHP 4 )

xml_set_external_entity_ref_handler -- set up external entity reference handler

Description

bool xml_set_external_entity_ref_handler ( resource parser, string handler)

Sets the external entity reference handler function for the XML parser parser. handler is a string containing the name of a function that must exist when xml_parse() is called for parser.

The function named by handler must accept five parameters, and should return an integer value. If the value returned from the handler is FALSE (which it will be if no value is returned), the XML parser will stop parsing and xml_get_error_code() will return XML_ERROR_EXTERNAL_ENTITY_HANDLING. handler ( resource parser, string open_entity_names, string base, string system_id, string public_id)

parser: The first parameter, parser, is a reference to the XML parser calling the handler.
open_entity_names: The second parameter, open_entity_names, is a space-separated list of the names of the entities that are open for the parse of this entity (including the name of the referenced entity).
base: This is the base for resolving the system identifier (system_id) of the external entity. Currently this parameter will always be set to an empty string.
system_id: The fourth parameter, system_id, is the system identifier as specified in the entity declaration.
public_id: The fifth parameter, public_id, is the public identifier as specified in the entity declaration, or an empty string if none was specified; the whitespace in the public identifier will have been normalized as required by the XML spec.

If a handler function is set to an empty string, or FALSE, the handler in question is disabled.

TRUE is returned if the handler is set up, FALSE if parser is not a parser.

Note: Instead of a function name, an array containing an object reference and a method name can also be supplied.

xml_set_notation_decl_handler

(PHP 3>= 3.0.6, PHP 4 )

xml_set_notation_decl_handler -- set up notation declaration handler

Description

bool xml_set_notation_decl_handler ( resource parser, string handler)

Sets the notation declaration handler function for the XML parser parser. handler is a string containing the name of a function that must exist when xml_parse() is called for parser.

A notation declaration is part of the document's DTD and has the following format:
<!NOTATION name {system_id | public_id}>
See section 4.7 of the XML 1.0 spec for the definition of notation declarations.

The function named by handler must accept five parameters: handler ( resource parser, string notation_name, string base, string system_id, string public_id)

parser: The first parameter, parser, is a reference to the XML parser calling the handler.
notation_name: This is the notation's name, as per the notation format described above.
base: This is the base for resolving the system identifier (system_id) of the notation declaration. Currently this parameter will always be set to an empty string.
system_id: System identifier of the external notation declaration.
public_id: Public identifier of the external notation declaration.

If a handler function is set to an empty string, or FALSE, the handler in question is disabled.

TRUE is returned if the handler is set up, FALSE if parser is not a parser.

Note: Instead of a function name, an array containing an object reference and a method name can also be supplied.

xml_set_object

(PHP 4 )

xml_set_object -- Use XML Parser within an object

Description

void xml_set_object ( resource parser, object object)

This function allows to use parser inside object. All callback functions could be set with xml_set_element_handler() etc and assumed to be methods of object.

<?php
class xml  {
    var $parser;

    function xml()
    {
        $this->parser = xml_parser_create();

        xml_set_object($this->parser, &$this);
        xml_set_element_handler($this->parser, "tag_open", "tag_close");
        xml_set_character_data_handler($this->parser, "cdata");
    }

    function parse($data)
    { 
        xml_parse($this->parser, $data);
    }

    function tag_open($parser, $tag, $attributes)
    { 
        var_dump($parser, $tag, $attributes); 
    }

    function cdata($parser, $cdata)
    {
        var_dump($parser, $cdata);
    }

    function tag_close($parser, $tag)
    {
        var_dump($parser, $tag);
    }

} // end of class xml

$xml_parser = new xml();
$xml_parser->parse("<A ID='hallo'>PHP</A>");
?>

xml_set_processing_instruction_handler

(PHP 3>= 3.0.6, PHP 4 )

xml_set_processing_instruction_handler -- Set up processing instruction (PI) handler

Description

bool xml_set_processing_instruction_handler ( resource parser, string handler)

Sets the processing instruction (PI) handler function for the XML parser parser. handler is a string containing the name of a function that must exist when xml_parse() is called for parser.

A processing instruction has the following format:

<?
       target 
       data?>

You can put PHP code into such a tag, but be aware of one limitation: in an XML PI, the PI end tag (?>) can not be quoted, so this character sequence should not appear in the PHP code you embed with PIs in XML documents. If it does, the rest of the PHP code, as well as the "real" PI end tag, will be treated as character data.

The function named by handler must accept three parameters: handler ( resource parser, string target, string data)

parser: The first parameter, parser, is a reference to the XML parser calling the handler.
target: The second parameter, target, contains the PI target.
data: The third parameter, data, contains the PI data.

If a handler function is set to an empty string, or FALSE, the handler in question is disabled.

TRUE is returned if the handler is set up, FALSE if parser is not a parser.

Note: Instead of a function name, an array containing an object reference and a method name can also be supplied.

xml_set_start_namespace_decl_handler

(PHP 4 >= 4.0.5)

xml_set_start_namespace_decl_handler -- Set up character data handler

Description

bool xml_set_start_namespace_decl_handler ( resource pind, string hdl)

Warning

This function is currently not documented; only the argument list is available.

Note: Instead of a function name, an array containing an object reference and a method name can also be supplied.

xml_set_unparsed_entity_decl_handler

(PHP 3>= 3.0.6, PHP 4 )

xml_set_unparsed_entity_decl_handler -- Set up unparsed entity declaration handler

Description

bool xml_set_unparsed_entity_decl_handler ( resource parser, string handler)

Sets the unparsed entity declaration handler function for the XML parser parser. handler is a string containing the name of a function that must exist when xml_parse() is called for parser.

This handler will be called if the XML parser encounters an external entity declaration with an NDATA declaration, like the following:
<!ENTITY name {publicId | systemId} NDATA notationName>

See section 4.2.2 of the XML 1.0 spec for the definition of notation declared external entities.

The function named by handler must accept six parameters: handler ( resource parser, string entity_name, string base, string system_id, string public_id, string notation_name)

parser: The first parameter, parser, is a reference to the XML parser calling the handler.
entity_name: The name of the entity that is about to be defined.
base: This is the base for resolving the system identifier (systemId) of the external entity. Currently this parameter will always be set to an empty string.
system_id: System identifier for the external entity.
public_id: Public identifier for the external entity.
notation_name: Name of the notation of this entity (see xml_set_notation_decl_handler()).

If a handler function is set to an empty string, or FALSE, the handler in question is disabled.

TRUE is returned if the handler is set up, FALSE if parser is not a parser.

Note: Instead of a function name, an array containing an object reference and a method name can also be supplied.

CVII. XML-RPC functions

Introduction

These functions can be used to write XML-RPC servers and clients. You can find more information about XML-RPC at http://www.xmlrpc.com/, and more documentation on this extension and it's functions at http://xmlrpc-epi.sourceforge.net/.

Warning

Requirements

No external libraries are needed to build this extension.

Installation

XML-RPC support in PHP is not enabled by default. You will need to use the --with-xmlrpc configuration option when compiling PHP to enable XML-RPC support. This extension is bundled into PHP as of 4.1.0.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. XML-RPC configuration options

Name	Default	Changeable
xmlrpc_errors	"0"	PHP_INI_SYSTEM
xmlrpc_error_number	"0"	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Table of Contents
xmlrpc_decode_request -- Decodes XML into native PHP types
xmlrpc_decode -- Decodes XML into native PHP types
xmlrpc_encode_request -- Generates XML for a method request
xmlrpc_encode -- Generates XML for a PHP value
xmlrpc_get_type -- Gets xmlrpc type for a PHP value. Especially useful for base64 and datetime strings
xmlrpc_parse_method_descriptions -- Decodes XML into a list of method descriptions
xmlrpc_server_add_introspection_data -- Adds introspection documentation
xmlrpc_server_call_method -- Parses XML requests and call methods
xmlrpc_server_create -- Creates an xmlrpc server
xmlrpc_server_destroy -- Destroys server resources
xmlrpc_server_register_introspection_callback -- Register a PHP function to generate documentation
xmlrpc_server_register_method -- Register a PHP function to resource method matching method_name
xmlrpc_set_type -- Sets xmlrpc type, base64 or datetime, for a PHP string value

CVIII. XSLT functions

Introduction

This PHP extension provides a processor independent API to XSLT transformations. Currently this extension only supports the Sablotron library from the Ginger Alliance. Support is planned for other libraries, such as the Xalan library or the libxslt library.

XSLT (Extensible Stylesheet Language (XSL) Transformations) is a language for transforming XML documents into other XML documents. It is a standard defined by The World Wide Web Consortium (W3C). Information about XSLT and related technologies can be found at http://www.w3.org/TR/xslt.

Note: This extension is different than the sablotron extension distributed with versions of PHP prior to PHP 4.1, currently only the new XSLT extension in PHP 4.1 is supported. If you need support for the old extension, please ask your questions on the PHP mailing lists.

Requirements

This extension uses Sablotron and expat, which can both be found at http://www.gingerall.com/. Binaries are provided as well as source.

Installation

On UNIX, run configure with the --enable-xslt --with-xslt-sablot options. The Sablotron library should be installed somewhere your compiler can find it.

Make sure you have the same libraries linked to the Sablotron library as those, which are linked with php. The configuration options: --with-expat-dir --with-iconv-dir are there to help you specify them. When asking for support, always mention these directives, and whether there are other versions of those libraries installed on your system somewhere. Naturally, provide all the version numbers.

JavaScript E-XSLT support: If you compiled Sablotron with JavaScript support, you must specify the option: --with-sablot-js.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

XSLT_SILENT (integer): Drop all logging and error reporting. This is a generic option for all backends that may be added in the future.
XSLT_SAB_PARSE_PUBLIC_ENTITIES (integer): Tell Sablotron to parse public entities. By default this has been turned off.
XSLT_SAB_DISABLE_ADDING_META (integer): Do not add the meta tag "Content-Type" for HTML output. The default is set during compilation of Sablotron.
XSLT_SAB_DISABLE_STRIPPING (integer): Suppress the whitespace stripping (on data files only).
XSLT_SAB_IGNORE_DOC_NOT_FOUND (integer): Consider unresolved documents (the document() function) non-lethal.

Table of Contents
xslt_create -- Create a new XSLT processor
xslt_errno -- Return a error number
xslt_error -- Return a error string
xslt_free -- Free XSLT processor
xslt_process -- Perform an XSLT transformation
xslt_set_base -- Set the base URI for all XSLT transformations
xslt_set_encoding -- Set the encoding for the parsing of XML documents
xslt_set_error_handler -- Set an error handler for a XSLT processor
xslt_set_log -- Set the log file to write log messages to
xslt_set_sax_handler -- Set SAX handlers for a XSLT processor
xslt_set_sax_handlers -- Set the SAX handlers to be called when the XML document gets processed
xslt_set_scheme_handler -- Set Scheme handlers for a XSLT processor
xslt_set_scheme_handlers -- Set the scheme handlers for the XSLT processor

Example 1. Handling errors using the xslt_error() and xslt_errno() functions.
<?php $xh = xslt_create(); $result = xslt_process($xh, 'dog.xml', 'pets.xsl'); if (!$result) { die(sprintf("Cannot process XSLT document [%d]: %s", xslt_errno($xh), xslt_error($xh))); } print($result); xslt_free($xh); ?>

xslt_free

(PHP 4 >= 4.0.3)

xslt_free -- Free XSLT processor

Description

void xslt_free ( resource xh)

Free the XSLT processor identified by the given handle.

xslt_process

(PHP 4 >= 4.0.3)

xslt_process -- Perform an XSLT transformation

Description

mixed xslt_process ( resource xh, string xmlcontainer, string xslcontainer [, string resultcontainer [, array arguments [, array parameters]]])

The xslt_process() function is the crux of the new XSLT extension. It allows you to perform an XSLT transformation using almost any type of input source - the containers. This is accomplished through the use of argument buffers -- a concept taken from the Sablotron XSLT processor (currently the only XSLT processor this extension supports). The input containers default to a filename 'containing' the document to be processed. The result container defaults to a filename for the transformed document. If the result container is not specified - i.e. NULL - than the result is returned.

Warning

This function has changed it's arguments, sinceversion 4.0.6. Do NOT provide the actual xml or xsl content as 2nd and 3rd argument, as this will create a segmentation fault, in Sablotron versions up to and including 0.95.

Containers can also be set via the $arguments array (see below).

The simplest type of transformation with the xslt_process() function is the transformation of an XML file with an XSLT file, placing the result in a third file containing the new XML (or HTML) document. Doing this with sablotron is really quite easy...

Example 1. Using the xslt_process() to transform an XML file and a XSL file to a new XML file

<?php

// Allocate a new XSLT processor
$xh = xslt_create();

// Process the document
if (xslt_process($xh, 'sample.xml', 'sample.xsl', 'result.xml')) {
    print "SUCCESS, sample.xml was transformed by sample.xsl into result.xml";
    print ", result.xml has the following contents\n<br>\n";
    print "<pre>\n";
    readfile('result.xml');
    print "</pre>\n";
}
else {
    print "Sorry, sample.xml could not be transformed by sample.xsl into";
    print "  result.xml the reason is that " . xslt_error($xh) . " and the ";
    print "error code is " . xslt_errno($xh);
}

xslt_free($xh);

?>

While this functionality is great, many times, especially in a web environment, you want to be able to print out your results directly. Therefore, if you omit the third argument to the xslt_process() function (or provide a NULL value for the argument), it will automatically return the value of the XSLT transformation, instead of writing it to a file...

Example 2. Using the xslt_process() to transform an XML file and a XSL file to a variable containing the resulting XML data
<?php // Allocate a new XSLT processor $xh = xslt_create(); // Process the document, returning the result into the $result variable $result = xslt_process($xh, 'sample.xml', 'sample.xsl'); if ($result) { print "SUCCESS, sample.xml was transformed by sample.xsl into the \$result"; print " variable, the \$result variable has the following contents\n<br>\n"; print "<pre>\n"; print $result; print "</pre>\n"; } else { print "Sorry, sample.xml could not be transformed by sample.xsl into"; print " the \$result variable the reason is that " . xslt_error($xh) . print " and the error code is " . xslt_errno($xh); } xslt_free($xh); ?>

The above two cases are the two simplest cases there are when it comes to XSLT transformation and I'd dare say that they are the most common cases, however, sometimes you get your XML and XSLT code from external sources, such as a database or a socket. In these cases you'll have the XML and/or XSLT data in a variable -- and in production applications the overhead of dumping these to file may be too much. This is where XSLT's "argument" syntax, comes to the rescue. Instead of files as the XML and XSLT arguments to the xslt_process() function, you can specify "argument place holders" which are then subsituted by values given in the arguments array (5th parameter to the xslt_process() function). The following is an example of processing XML and XSLT into a result variable without the use of files at all.

void xslt_set_log ( resource xh, mixed log)

xh: A reference to the XSLT parser.
log: This parameter is either a boolean value which toggles logging on and off, or a string containing the logfile in which log errors too.

Warning

This function is currently not documented; only the argument list is available.

CIX. YAZ functions

Introduction

This extension offers a PHP interface to the YAZ toolkit that implements the Z39.50 protocol for information retrieval. With this extension you can easily implement a Z39.50 origin (client) that searches or scans Z39.50 targets (servers) in parallel.

The module hides most of the complexity of Z39.50 so it should be fairly easy to use. It supports persistent stateless connections very similar to those offered by the various SQL APIs that are available for PHP. This means that sessions are stateless but shared amongst users, thus saving the connect and initialize phase steps in most cases.

YAZ is available at http://www.indexdata.dk/yaz/. You can find news information, example scripts, etc. for this extension at http://www.indexdata.dk/phpyaz/.

Installation

Compile YAZ and install it. Build PHP with your favourite modules and add option --with-yaz. Your task is roughly the following:

gunzip -c yaz-1.6.tar.gz|tar xf -
gunzip -c php-4.0.X.tar.gz|tar xf -
cd yaz-1.6
./configure --prefix=/usr
make
make install
cd ../php-4.0.X
./configure --with-yaz=/usr/bin
make
make install

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Table 1. YAZ configuration options

Name	Default	Changeable
yaz.max_links	"100"	PHP_INI_ALL
yaz.log_file	""	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Examples

PHP/YAZ keeps track of connections with targets (Z-Associations). A positive integer represents the ID of a particular association.

Example 1. Parallel searching using YAZ()
The script below demonstrates the parallel searching feature of the API. When invoked with no arguments it prints a query form; else (arguments are supplied) it searches the targets as given in in array host.
$num_hosts = count ($host); if (empty($term) || count($host) == 0) { echo '<form method="get"> <input type="checkbox" name="host[]" value="bagel.indexdata.dk/gils"> GILS test <input type="checkbox" name="host[]" value="localhost:9999/Default"> local test <input type="checkbox" checked="1" name="host[]" value="z3950.bell-labs.com/books"> BELL Labs Library <br> RPN Query: <input type="text" size="30" name="term"> <input type="submit" name="action" value="Search"> '; } else { echo 'You searced for ' . htmlspecialchars($term) . '<br>'; for ($i = 0; $i < $num_hosts; $i++) { $id[] = yaz_connect($host[$i]); yaz_syntax($id[$i],"sutrs"); yaz_search($id[$i],"rpn",$term); } yaz_wait(); for ($i = 0; $i < $num_hosts; $i++) { echo '<hr>' . $host[$i] . ":"; $error = yaz_error($id[$i]); if (!empty($error)) { echo "Error: $error"; } else { $hits = yaz_hits($id[$i]); echo "Result Count $hits"; } echo '<dl>'; for ($p = 1; $p <= 10; $p++) { $rec = yaz_record($id[$i],$p,"string"); if (empty($rec)) continue; echo "<dt><b>$p</b></dt><dd>"; echo ereg_replace("\n", "<br>\n",$rec); echo "</dd>"; } echo '</dl>'; } }

Table of Contents
yaz_addinfo -- Returns additional error information
yaz_ccl_conf -- Configure CCL parser
yaz_ccl_parse -- Invoke CCL Parser
yaz_close -- Closes a YAZ connection
yaz_connect -- Prepares for a connection and Z-association to a Z39.50 target.
yaz_database -- Specifies the databases within a session
yaz_element -- Specifies Element-Set Name for retrieval
yaz_errno -- Returns error number
yaz_error -- Returns error description
yaz_hits -- Returns number of hits for last search
yaz_itemorder -- Prepares for Z39.50 Item Order with an ILL-Request package
yaz_present -- Prepares for retrieval (Z39.50 present).
yaz_range -- Specifies the maximum number of records to retrieve
yaz_record -- Returns a record
yaz_scan_result -- Returns Scan Response result
yaz_scan -- Prepares for a scan
yaz_search -- Prepares for a search
yaz_sort -- Sets sorting criteria
yaz_syntax -- Specifies the preferred record syntax for retrieval.
yaz_wait -- Wait for Z39.50 requests to complete

yaz_addinfo

(PHP 4 >= 4.0.1)

yaz_addinfo -- Returns additional error information

Description

int yaz_addinfo ( int id)

Returns additional error message for target (last request). An empty string is returned if last operation was a success or if no additional information was provided by the target.

yaz_ccl_conf

(PHP 4 >= 4.0.5)

yaz_ccl_conf -- Configure CCL parser

Description

int yaz_ccl_conf ( int id, array config)

int yaz_connect ( string zurl [, mixed options])

This function returns a positive ID on success; zero on failure.

yaz_connect() prepares for a connection to a Z39.50 target. The zurl argument takes the form host[:port][/database]. If port is omitted 210 is used. If database is omitted Default is used. This function is non-blocking and doesn't attempt to establish a socket - it merely prepares a connect to be performed later when yaz_wait() is called.

If the second argument, options, is given as a string it is treated as the Z39.50 V2 authentication string (OpenAuth).

If options is given as an array the contents of the array serves as options. Note that array options are only supported for PHP 4.1.0 and later.

yaz_connect() options

user: Username for authentication.
group: Group for authentication.
password: Password for authentication.
cookie: Cookie for session (YAZ proxy).
proxy: Proxy for connection (YAZ proxy).
persistent: A boolean. If TRUE the connection is persistent; If FALSE the connection is not persistent. By default connections are persistent.
piggyback: A boolean. If TRUE piggyback is enabled for searches; If FALSE piggyback is disabled. By default piggyback is enabled. Enabling piggyback is more efficient and usually saves a network-round-trip for first time fetches of records. However, a few Z39.50 targets doesn't support piggyback or they ignore element set names. For those, piggyback should be disabled.

yaz_database

(PHP 4 >= 4.0.6)

yaz_database -- Specifies the databases within a session

Description

int yaz_database ( int id, string databases)

int yaz_hits ( int id)

yaz_hits() returns number of hits for last search.

yaz_itemorder

(PHP 4 >= 4.0.5)

yaz_itemorder -- Prepares for Z39.50 Item Order with an ILL-Request package

Description

int yaz_itemorder ( array args)

This function prepares for an Extended Services request using the Profile for the Use of Z39.50 Item Order Extended Service to Transport ILL (Profile/1). See this and the specification. The args parameter must be a hash array with information about the Item Order request to be sent. The key of the hash is the name of the corresponding ASN.1 tag path. For example, the ISBN below the Item-ID has the key item-id,ISBN.

The ILL-Request parameters are:

protocol-version-num
transaction-id,initial-requester-id,person-or-institution-symbol,person
transaction-id,initial-requester-id,person-or-institution-symbol,institution
transaction-id,initial-requester-id,name-of-person-or-institution,name-of-person
transaction-id,initial-requester-id,name-of-person-or-institution,name-of-institution
transaction-id,transaction-group-qualifier
transaction-id,transaction-qualifier
transaction-id,sub-transaction-qualifier
service-date-time,this,date
service-date-time,this,time
service-date-time,original,date
service-date-time,original,time
requester-id,person-or-institution-symbol,person
requester-id,person-or-institution-symbol,institution
requester-id,name-of-person-or-institution,name-of-person
requester-id,name-of-person-or-institution,name-of-institution
responder-id,person-or-institution-symbol,person
responder-id,person-or-institution-symbol,institution
responder-id,name-of-person-or-institution,name-of-person
responder-id,name-of-person-or-institution,name-of-institution
transaction-type
delivery-address,postal-address,name-of-person-or-institution,name-of-person
delivery-address,postal-address,name-of-person-or-institution,name-of-institution
delivery-address,postal-address,extended-postal-delivery-address
delivery-address,postal-address,street-and-number
delivery-address,postal-address,post-office-box
delivery-address,postal-address,city
delivery-address,postal-address,region
delivery-address,postal-address,country
delivery-address,postal-address,postal-code
delivery-address,electronic-address,telecom-service-identifier
delivery-address,electronic-address,telecom-service-addreess
billing-address,postal-address,name-of-person-or-institution,name-of-person
billing-address,postal-address,name-of-person-or-institution,name-of-institution
billing-address,postal-address,extended-postal-delivery-address
billing-address,postal-address,street-and-number
billing-address,postal-address,post-office-box
billing-address,postal-address,city
billing-address,postal-address,region
billing-address,postal-address,country
billing-address,postal-address,postal-code
billing-address,electronic-address,telecom-service-identifier
billing-address,electronic-address,telecom-service-addreess
ill-service-type
requester-optional-messages,can-send-RECEIVED
requester-optional-messages,can-send-RETURNED
requester-optional-messages,requester-SHIPPED
requester-optional-messages,requester-CHECKED-IN
search-type,level-of-service
search-type,need-before-date
search-type,expiry-date
search-type,expiry-flag
place-on-hold
client-id,client-name
client-id,client-status
client-id,client-identifier
item-id,item-type
item-id,call-number
item-id,author
item-id,title
item-id,sub-title
item-id,sponsoring-body
item-id,place-of-publication
item-id,publisher
item-id,series-title-number
item-id,volume-issue
item-id,edition
item-id,publication-date
item-id,publication-date-of-component
item-id,author-of-article
item-id,title-of-article
item-id,pagination
item-id,ISBN
item-id,ISSN
item-id,additional-no-letters
item-id,verification-reference-source
copyright-complicance
retry-flag
forward-flag
requester-note
forward-note

There are also a few parameters that are part of the Extended Services Request package and the ItemOrder package:

package-name
user-id
contact-name
contact-phone
contact-email
itemorder-item

yaz_present

(PHP 4 >= 4.0.5)

yaz_present -- Prepares for retrieval (Z39.50 present).

array yaz_scan_result ( int id [, array & result])

Given a target ID this function returns and array with terms as received from the target in the last Scan Response. This function returns an array (0..n-1) where n is the number of terms returned. Each value is a pair where first item is term, second item is result-count. If the result is given it will be modified to hold additional information taken from the Scan Response: number (number of entries returned), stepsize (Step-size), position (position of term), status (Scan Status).

yaz_scan

(PHP 4 >= 4.0.5)

yaz_scan -- Prepares for a scan

Description

int yaz_scan ( int id, string type, string startterm [, array flags])

This function prepares for a Z39.50 Scan Request. Argument id specifies target ID. Starting term point for the scan is given by startterm. The form in which is the starting term is specified is given by type. Currently type rpn is supported. The optional flags specifies additional information to control the behaviour of the scan request. Three indexes are currently read from the flags: number (number of terms requested), position (preferred position of term) and stepSize (preferred step size). To actually tranfer the Scan Request to the target and receive the Scan Response, yaz_wait() must be called. Upon completion of yaz_wait() call yaz_error() and yaz_scan_result() to handle the response.

The syntax of startterm is similar to the RPN query as described in yaz_search(). The startterm consists of zero or more @attr-operator specifications, then followed by exactly one token.

Example 1. PHP function that scans titles
function scan_titles($id, $starterm) { yaz_scan($id,"rpn", "@attr 1=4 " . $starterm); yaz_wait(); $errno = yaz_errno($id); if ($errno == 0) { $ar = yaz_scan_result($id,&$options); echo 'Scan ok; '; $ar = yaz_scan_result($id, &$options); while(list($key,$val)=each($options)) { echo "$key = $val  "; } echo '<br><table><tr><td>'; while(list($key,list($k, $term, $tcount))=each($ar)) { if (empty($k)) continue; echo "<tr><td>$term</td><td>"; echo $tcount; echo "</td></tr>"; } echo '</table>'; } else { echo "Scan failed. Error: " . yaz_error($id) . "<br>"; } }

yaz_search

(PHP 4 >= 4.0.1)

yaz_search -- Prepares for a search

Description

int yaz_search ( int id, string type, string query)

yaz_search() prepares for a search on the target with given id. The type represents the query type - only "rpn" is supported now in which case the third argument specifies a Type-1 query (RPN). Like yaz_connect() this function is non-blocking and only prepares for a search to be executed later when yaz_wait() is called.

The RPN query

The RPN query is a textual represenation of the Type-1 query as defined by the Z39.50 standard. However, in the text representation as used by YAZ a prefix notation is used, that is the operater precedes the operands. The query string is a sequence of tokens where white space is ignored is ignored unless surrounded by double quotes. Tokens beginning with an at-character (@) are considered operators, otherwise they are treated as search terms.

Table 1. RPN Operators

Syntax	Description
`@and query1 query2`	intersection of query1 and query2
`@or query1 query2`	union of query1 and query2
`@not query1 query2`	query1 and not query2
`@set name`	result set reference
`@attrset set query`	specifies attribute-set for query. This construction is only allowed once - in the beginning of the whole query
`@attr set type=value query`	applies attribute to query. The type and value are integers specifying the attribute-type and attribute-value respectively. The set, if given, specifies the attribute-set.

Example 1. Query Examples

Query
computer
matches documents where "computer" occur. No attributes are specified.

The Query
"donald knuth"
matches documents where "donald knuth" occur.

For the query
@attr 1=4 art
attribute type is 1 (Bib-1 use), attribute value is 4 Title), so this should match documents where art occur in the title.

Another more complex one:
@attrset gils @and @attr 1=4 art @attr 1=1003 "donald knuth"
The query as a whole uses the GILS attributeset. The query matches documents where art occur in the title and in which donald knuth occur in the author.

yaz_sort

(PHP 4 >= 4.1.0)

yaz_sort -- Sets sorting criteria

Description

int yaz_sort ( int id, string criteria)

This function sets sorting criteria and enables Z39.50 Sort. Use this function together with yaz_search() or yaz_present(). Using this function alone doesn't have any effect. If used in conjunction with yaz_search() a Z39.50 Sort will be sent after a search response has been received and before any records are retrieved with Z39.50 Present. The criteria takes the form

field1 flags1 field2 flags2 ...

where field1 specifies primary attributes for sort, field2 seconds, etc.. The field specifies either numerical attribute combinations consisting of type=value pairs separated by comma (e.g. 1=4,2=1) ; or the field may specify a plain string criteria (e.g. title. The flags is a sequnce of the following characters which may not be separated by any white space.

Sort Flags

a: Sort ascending
d: Sort descending
i: Case insensitive sorting
s: Case sensitive sorting

Example 1. Sort Criterias

To sort on Bib1 attribute title, case insensitive, and ascending you'd use the following sort criteria:
1=4 ia

If the secondary sorting criteria should be author, case sensitive and ascending you'd use:
1=4 ia 1=1003 sa

yaz_syntax

(PHP 4 >= 4.0.1)

yaz_syntax -- Specifies the preferred record syntax for retrieval.

Description

int yaz_syntax ( int id, string syntax)

The syntax is specified as an OID (Object Identifier) in a raw dot-notation (like 1.2.840.10003.5.10) or as one of the known registered record syntaxes (sutrs, usmarc, grs1, xml, etc.). This function is used in conjunction with yaz_search() and yaz_present() to specify the preferred record syntax for retrieval.

yaz_wait

(PHP 4 >= 4.0.1)

yaz_wait -- Wait for Z39.50 requests to complete

Description

int yaz_wait ( [ array options])

This function carries out networked (blocked) activity for outstanding requests which have been prepared by the functions yaz_connect(), yaz_search(), yaz_present(), yaz_scan() and yaz_itemorder(). yaz_wait() returns when all targets have either completed all requests or aborted (in case of errors).

If the options array is given that holds options that change the behaviour of yaz_wait().

timeout: Sets timeout in seconds. If a target hasn't responded within the timeout it is considered dead and yaz_wait() returns. The default value for timeout is 15 seconds.

CX. YP/NIS Functions

Introduction

NIS (formerly called Yellow Pages) allows network management of important administrative files (e.g. the password file). For more information refer to the NIS manpage and Introduction to YP/NIS. There is also a book called Managing NFS and NIS by Hal Stern.

Installation

To get these functions to work, you have to configure PHP with --with-yp(PHP 3) or --enable-yp(PHP 4).

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

YPERR_BADARGS (integer)
YPERR_BADDB (integer)
YPERR_BUSY (integer)
YPERR_DOMAIN (integer)
YPERR_KEY (integer)
YPERR_MAP (integer)
YPERR_NODOM (integer)
YPERR_NOMORE (integer)
YPERR_PMAP (integer)
YPERR_RESRC (integer)
YPERR_RPC (integer)
YPERR_YPBIND (integer)
YPERR_YPERR (integer)
YPERR_YPSERV (integer)
YPERR_VERS (integer)

Table of Contents
yp_all -- Traverse the map and call a function on each entry
yp_cat -- Return an array containing the entire map
yp_err_string -- Returns the error string associated with the previous operation
yp_errno -- Returns the error code of the previous operation
yp_first -- Returns the first key-value pair from the named map
yp_get_default_domain -- Fetches the machine's default NIS domain
yp_master -- Returns the machine name of the master NIS server for a map
yp_match -- Returns the matched line
yp_next -- Returns the next key-value pair in the named map.
yp_order -- Returns the order number for a map

1 args to function are bad

2 RPC failure - domain has been unbound

3 can't bind to server on this domain

4 no such map in server's domain

5 no such key in map

6 internal yp server or client error

7 resource allocation failure

8 no more records in map database

9 can't communicate with portmapper

10 can't communicate with ypbind

11 can't communicate with ypserv

12 local domain name not set

13 yp database is bad

14 yp version mismatch

15 access violation

16 database busy

yp_first

(PHP 3>= 3.0.7, PHP 4 )

yp_first -- Returns the first key-value pair from the named map

Description

array yp_first ( string domain, string map)

yp_first() returns the first key-value pair from the named map in the named domain, otherwise FALSE.

Example 1. Example for the NIS first
<?php $entry = yp_first($domain, "passwd.byname"); $key = $entry ["key"]; $value = $entry ["value"]; echo "First entry in this map has key " . $key . " and value " . $value; ?>

yp_get_default_domain

(PHP 3>= 3.0.7, PHP 4 )

yp_get_default_domain -- Fetches the machine's default NIS domain

Description

int yp_get_default_domain ( void)

yp_get_default_domain() returns the default domain of the node or FALSE. Can be used as the domain parameter for successive NIS calls.

A NIS domain can be described a group of NIS maps. Every host that needs to look up information binds itself to a certain domain. Refer to the documents mentioned at the beginning for more detailed information.

Example 1. Example for the default domain
<?php $domain = yp_get_default_domain(); echo "Default NIS domain is: " . $domain; ?>

yp_master

(PHP 3>= 3.0.7, PHP 4 )

yp_master -- Returns the machine name of the master NIS server for a map

Description

string yp_master ( string domain, string map)

yp_master() returns the machine name of the master NIS server for a map.

Example 1. Example for the NIS master
<?php $number = yp_master ($domain, $mapname); echo "Master for this map is: " . $master; ?>

yp_match

(PHP 3>= 3.0.7, PHP 4 )

yp_match -- Returns the matched line

Description

string yp_match ( string domain, string map, string key)

yp_match() returns the value associated with the passed key out of the specified map or FALSE. This key must be exact.

Example 1. Example for NIS match
<?php $entry = yp_match ($domain, "passwd.byname", "joe"); echo "Matched entry is: " . $entry; ?>

In this case this could be: joe:##joe:11111:100:Joe User:/home/j/joe:/usr/local/bin/bash

yp_next

(PHP 3>= 3.0.7, PHP 4 )

yp_next -- Returns the next key-value pair in the named map.

Description

array yp_next ( string domain, string map, string key)

yp_next() returns the next key-value pair in the named map after the specified key or FALSE.

Example 1. Example for NIS next
<?php $entry = yp_next ($domain, "passwd.byname", "joe"); if (!$entry) { echo "No more entries found\n";  } $key = key ($entry); echo "The next entry after joe has key " . $key . " and value " . $entry[$key]; ?>

yp_order

(PHP 3>= 3.0.7, PHP 4 )

yp_order -- Returns the order number for a map

Description

int yp_order ( string domain, string map)

yp_order() returns the order number for a map or FALSE.

Example 1. Example for the NIS order
<?php $number = yp_order($domain,$mapname); echo "Order number for this map is: " . $number; ?>

CXI. Zip File Functions (Read Only Access)

Introduction

This module enables you to transparently read ZIP compressed archives and the files inside them.

Requirements

This module uses the functions of the ZZIPlib library by Guido Draheim. You need ZZIPlib version >= 0.10.6.

Note that ZZIPlib only provides a subset of functions provided in a full implementation of the ZIP compression algorithm and can only read ZIP file archives. A normal ZIP utility is needed to create the ZIP file archives read by this library.

Installation

Zip support in PHP is not enabled by default. You will need to use the --with-zip configuration option when compiling PHP to enable zip support.

Note: Zip support before PHP 4.1.0 is experimental. This section reflects the Zip extension as it exists in PHP 4.1.0 and later.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Examples

This example opens a ZIP file archive, reads each file in the archive and prints out its contents. The test2.zip archive used in this example is one of the test archives in the ZZIPlib source distribution.

Example 1. Zip Usage Example

<?php

$zip = zip_open("/tmp/test2.zip");

if ($zip) {

    while ($zip_entry = zip_read($zip)) {
        echo "Name:               " . zip_entry_name($zip_entry) . "\n";
        echo "Actual Filesize:    " . zip_entry_filesize($zip_entry) . "\n";
        echo "Compressed Size:    " . zip_entry_compressedsize($zip_entry) . "\n";
        echo "Compression Method: " . zip_entry_compressionmethod($zip_entry) . "\n";

        if (zip_entry_open($zip, $zip_entry, "r")) {
            echo "File Contents:\n";
            $buf = zip_entry_read($zip_entry, zip_entry_filesize($zip_entry));
            echo "$buf\n";

            zip_entry_close($zip_entry);
        }
        echo "\n";

    }

    zip_close($zip);

}

?>

Table of Contents
zip_close -- Close a Zip File Archive
zip_entry_close -- Close a Directory Entry
zip_entry_compressedsize -- Retrieve the Compressed Size of a Directory Entry
zip_entry_compressionmethod -- Retrieve the Compression Method of a Directory Entry
zip_entry_filesize -- Retrieve the Actual File Size of a Directory Entry
zip_entry_name -- Retrieve the Name of a Directory Entry
zip_entry_open -- Open a Directory Entry for Reading
zip_entry_read -- Read From an Open Directory Entry
zip_open -- Open a Zip File Archive
zip_read -- Read Next Entry in a Zip File Archive

zip_close

(PHP 4 >= 4.1.0)

zip_close -- Close a Zip File Archive

Description

void zip_close ( resource zip)

bool zip_entry_open ( resource zip, resource zip_entry [, string mode])

Opens a directory entry in a zip file for reading. The parameter zip is a valid resource handle returned by zip_open(). The parameter zip_entry is a directory entry resource returned by zip_read(). The optional parameter mode can be any of the modes specified in the documentaion for fopen().

Note: Currently, mode is ignored and is always "rb". This is due to the fact that zip support in PHP is read only access. Please see fopen() for an explanation of various modes, including "rb".

Returns TRUE on success or FALSE on failure.

Note: Unlike fopen() and other similar functions, the return value of zip_entry_open() only indicates the result of the operation and is not needed for reading or closing the directory entry.

zip_entry_read

(PHP 4 >= 4.1.0)

zip_entry_read -- Read From an Open Directory Entry

Description

string zip_entry_read ( resource zip_entry [, int length])

Reads up to length bytes from an open directory entry. If length is not specified, then zip_entry_read() will attempt to read 1024 bytes. The parameter zip_entry is a valid directory entry returned by zip_read().

Note: The length parameter should be the uncompressed length you wish to read.

Returns the data read, or FALSE if the end of the file is reached.

zip_open

(PHP 4 >= 4.1.0)

zip_open -- Open a Zip File Archive

Description

resource zip_open ( string filename)

Opens a new zip archive for reading. The filename parameter is the filename of the zip archive to open.

Returns a resource handle for later use with zip_read() and zip_close() or returns FALSE if filename does not exist.

See also zip_read() and zip_close().

zip_read

(PHP 4 >= 4.1.0)

zip_read -- Read Next Entry in a Zip File Archive

Description

resource zip_read ( resource zip)

Reads the next entry in a zip file archive. The parameter zip must be a zip archive previously opened by zip_open().

Returns a directory entry resource for later use with the zip_entry_...() functions.

CXII. Zlib Compression Functions

Introduction

This module enables you to transparently read and write gzip (.gz) compressed files, through versions of most of the filesystem functions which work with gzip-compressed files (and uncompressed files, too, but not with sockets).

Note: Version 4.0.4 introduced a fopen-wrapper for .gz-files, so that you can use a special 'zlib:' URL to access compressed files transparently using the normal f*() file access functions if you prepend the filename or path with a 'zlib:' prefix when calling fopen().
In version 4.3.0, this special prefix has been changed to 'zlib://' to prevent ambiguities with filenames containing ':'.
This feature requires a C runtime library that provides the fopencookie() function. To my current knowledge the GNU libc is the only library that provides this feature.

Requirements

This module uses the functions of zlib by Jean-loup Gailly and Mark Adler. You have to use a zlib version >= 1.0.9 with this module.

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

The zlib extension offers the option to transparently compress your pages on-the-fly, if the requesting browser supports this. Therefore there are three options in the configuration file php.ini.

Table 1. Zlib Configuration Options

Name	Default	Changeable
zlib.output_compression	"Off"	PHP_INI_ALL
zlib.output_compression_level	"-1"	PHP_INI_ALL
zlib.output_handler	""	PHP_INI_ALL

For further details and definition of the PHP_INI_* constants see ini_set().

Here is a short explanation of the configuration directives.

zlib.output_compression boolean/integer

Whether to transparently compress pages. If this option is set to "On" in php.ini or the Apache configuration, pages are compressed if the browser sends an "Accept-Encoding: gzip" or "deflate" header. "Content-Encoding: gzip" (respectively "deflate") and "Vary: Accept-Encoding" headers are added to the output.

You can use ini_set() to disable this in your script if the headers aren't already sent. If you output a "Content-Type: image/" header the compression is disabled, too (in order to circumvent a Netscape bug). You can reenable it, if you add "ini_set('zlib.output_compression', 'On')" after the header call which added the image content-type.

This option also accepts integer values instead of boolean "On"/"Off", using this you can set the output buffer size (default is 4KB).

Note: output_handler must be empty if this is set 'On' ! Instead you must use zlib.output_handler.

zlib.output_compression_level integer

Compression level used for transparent output compression.

zlib.output_handler string

You cannot specify additional output handlers if zlib.output_compression is activated here. This setting does the same as output_handler but in a different order.

Resource Types

This extension has no resource types defined.

Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

FORCE_GZIP (integer)
FORCE_DEFLATE (integer)

Examples

This example opens a temporary file and writes a test string to it, then it prints out the content of this file twice.

Example 1. Small Zlib Example

<?php

$filename = tempnam ('/tmp', 'zlibtest').'.gz';
print "<html>\n<head></head>\n<body>\n<pre>\n";
$s = "Only a test, test, test, test, test, test, test, test!\n";

// open file for writing with maximum compression
$zp = gzopen($filename, "w9");

// write string to file
gzwrite($zp, $s);

// close file
gzclose($zp);

// open file for reading
$zp = gzopen($filename, "r");

// read 3 char
print gzread($zp, 3);

// output until end of the file and close it.
gzpassthru($zp);

print "\n";

// open file and print content (the 2nd time).
if (readgzfile($filename) != strlen($s)) {
        echo "Error with zlib functions!";
}
unlink($filename);
print "</pre>\n</h1></body>\n</html>\n";

?>

Table of Contents
gzclose -- Close an open gz-file pointer
gzcompress -- Compress a string
gzdeflate -- Deflate a string
gzencode -- Create a gzip compressed string
gzeof -- Test for end-of-file on a gz-file pointer
gzfile -- Read entire gz-file into an array
gzgetc -- Get character from gz-file pointer
gzgets -- Get line from file pointer
gzgetss -- Get line from gz-file pointer and strip HTML tags
gzinflate -- Inflate a deflated string
gzopen -- Open gz-file
gzpassthru -- Output all remaining data on a gz-file pointer
gzputs -- Write to a gz-file pointer
gzread -- Binary-safe gz-file read
gzrewind -- Rewind the position of a gz-file pointer
gzseek -- Seek on a gz-file pointer
gztell -- Tell gz-file pointer read/write position
gzuncompress -- Uncompress a deflated string
gzwrite -- Binary-safe gz-file write
readgzfile -- Output a gz-file

(PHP 4 >= 4.0.4)

gzencode -- Create a gzip compressed string

Description

string gzencode ( string data [, int level [, int encoding_mode]])

This function returns a compressed version of the input data compatible with the output of the gzip program, or FALSE if an error is encountered. The optional parameter level can be given as 0 for no compression up to 9 for maximum compression, if not given the default compression level will be the default compression level of the zlib library.

You can also give FORCE_GZIP (the default) or FORCE_DEFLATE as optional third paramter encoding_mode. If you use FORCE_DEFLATE, you get a standard zlib deflated string (inclusive zlib headers) after the gzip file header but without the trailing crc32 checksum.

Note: level was added in PHP 4.2, before PHP 4.2 gzencode() only had the data and (optional) encoding_mode parameters..

The resulting data contains the appropriate headers and data structure to make a standard .gz file, e.g.:
Example 1. Creating a gzip file
<?php $data = implode("", file("bigfile.txt")); $gzdata = gzencode($data, 9); $fp = fopen("bigfile.txt.gz", "w"); fwrite($fp, $gzdata); fclose($fp); ?>

For more information on the GZIP file format, see the document: GZIP file format specification version 4.3 (RFC 1952).

gzeof

(PHP 3, PHP 4 )

gzeof -- Test for end-of-file on a gz-file pointer

string gzgets ( resource zp, int length)

Returns a (uncompressed) string of up to length - 1 bytes read from the file pointed to by fp. Reading ends when length - 1 bytes have been read, on a newline, or on EOF (whichever comes first).

If an error occurs, returns FALSE.

The file pointer must be valid, and must point to a file successfully opened by gzopen().

See also gzopen(), gzgetc(), and fgets().

gzgetss

(PHP 3, PHP 4 )

gzgetss -- Get line from gz-file pointer and strip HTML tags

Description

string gzgetss ( resource zp, int length [, string allowable_tags])

Identical to gzgets(), except that gzgetss() attempts to strip any HTML and PHP tags from the text it reads.

You can use the optional third parameter to specify tags which should not be stripped.

Note: Allowable_tags was added in PHP 3.0.13, PHP4B3.

See also gzgets(), gzopen(), and strip_tags().

gzinflate

(PHP 4 >= 4.0.4)

gzinflate -- Inflate a deflated string

Description

string gzinflate ( string data [, int length])

This function takes data compressed by gzdeflate() and returns the original uncompressed data or FALSE on error. The function will return an error if the uncompressed data is more than 256 times the length of the compressed input data or more than the optional parameter length.

gzopen

(PHP 3, PHP 4 )

gzopen -- Open gz-file

Description

resource gzopen ( string filename, string mode [, int use_include_path])

Opens a gzip (.gz) file for reading or writing. The mode parameter is as in fopen() ("rb" or "wb") but can also include a compression level ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman only compression as in "wb1h". (See the description of deflateInit2 in zlib.h for more information about the strategy parameter.)

gzopen() can be used to read a file which is not in gzip format; in this case gzread() will directly read from the file without decompression.

gzopen() returns a file pointer to the file opened, after that, everything you read from this file descriptor will be transparently decompressed and what you write gets compressed.

If the open fails, the function returns FALSE.

You can use the optional third parameter and set it to "1", if you want to search for the file in the include_path, too.

Example 1. gzopen() Example
$fp = gzopen ("/tmp/file.gz", "r");

gzpassthru

(PHP 3, PHP 4 )

gzpassthru -- Output all remaining data on a gz-file pointer

Description

int gzpassthru ( resource zp)

Reads to EOF on the given gz-file pointer and writes the (uncompressed) results to standard output.

If an error occurs, returns FALSE.

The file pointer must be valid, and must point to a file successfully opened by gzopen().

The gz-file is closed when gzpassthru() is done reading it (leaving zp useless).

gzputs

(PHP 3, PHP 4 )

gzputs -- Write to a gz-file pointer

Description

int gzputs ( resource zp, string str [, int length])

gzputs() is an alias to gzwrite(), and is identical in every way.

gzread

(PHP 3, PHP 4 )

gzread -- Binary-safe gz-file read

Description

string gzread ( resource zp, int length)

gzread() reads up to length bytes from the gz-file pointer referenced by zp. Reading stops when length (uncompressed) bytes have been read or EOF is reached, whichever comes first.

// get contents of a gz-file into a string
$filename = "/usr/local/something.txt.gz";
$zd = gzopen ($filename, "r");
$contents = gzread ($zd, 10000);
gzclose ($zd);

gzrewind

(PHP 3, PHP 4 )

gzrewind -- Rewind the position of a gz-file pointer

string gzuncompress ( string data [, int length])

This function takes data compressed by gzcompress() and returns the original uncompressed data or FALSE on error. The function will return an error if the uncompressed data is more than 256 times the length of the compressed input data or more than the optional parameter length.

gzwrite

(PHP 3, PHP 4 )

gzwrite -- Binary-safe gz-file write

Description

int gzwrite ( resource zp, string string [, int length])

gzwrite() writes the contents of string to the gz-file stream pointed to by zp. If the length argument is given, writing will stop after length (uncompressed) bytes have been written or the end of string is reached, whichever comes first.

gzwrite() returns the number of (uncompressed) bytes written to the gz-file stream pointed to by zp.

Note that if the length argument is given, then the magic_quotes_runtime configuration option will be ignored and no slashes will be stripped from string.

See also gzread(), gzopen(), and gzputs().

readgzfile

(PHP 3, PHP 4 )

readgzfile -- Output a gz-file

Description

int readgzfile ( string filename [, int use_include_path])

Reads a file, decompresses it and writes it to standard output.

readgzfile() can be used to read a file which is not in gzip format; in this case readgzfile() will directly read from the file without decompression.

Returns the number of (uncompressed) bytes read from the file. If an error occurs, FALSE is returned and unless the function was called as @readgzfile, an error message is printed.

The file filename will be opened from the filesystem and its contents written to standard output.

You can use the optional second parameter and set it to "1", if you want to search for the file in the include_path, too.

See also gzpassthru(), gzfile(), and gzopen().

V. Extending PHP 4.0

Hacking the Core of PHP

Those who know don't talk.
Those who talk don't know.

Sometimes, PHP "as is" simply isn't enough. Although these cases are rare for the average user, professional applications will soon lead PHP to the edge of its capabilities, in terms of either speed or functionality. New functionality cannot always be implemented natively due to language restrictions and inconveniences that arise when having to carry around a huge library of default code appended to every single script, so another method needs to be found for overcoming these eventual lacks in PHP.

As soon as this point is reached, it's time to touch the heart of PHP and take a look at its core, the C code that makes PHP go.

Table of Contents
24. Overview
25. Extension Possibilities
26. Source Layout
27. PHP's Automatic Build System
28. Creating Extensions
29. Using Extensions
30. Troubleshooting
31. Source Discussion
32. Accepting Arguments
33. Creating Variables
34. Duplicating Variable Contents: The Copy Constructor
35. Returning Values
36. Printing Information
37. Startup and Shutdown Functions
38. Calling User Functions
39. Initialization File Support
40. Where to Go from Here
41. Reference: Some Configuration Macros
42. API Macros

Hacking the Core of PHP

Chapter 24. Overview

"Extending PHP" is easier said than done. PHP has evolved to a full-fledged tool consisting of a few megabytes of source code, and to hack a system like this quite a few things have to be learned and considered. When structuring this chapter, we finally decided on the "learn by doing" approach. This is not the most scientific and professional approach, but the method that's the most fun and gives the best end results. In the following sections, you'll learn quickly how to get the most basic extensions to work almost instantly. After that, you'll learn about Zend's advanced API functionality. The alternative would have been to try to impart the functionality, design, tips, tricks, etc. as a whole, all at once, thus giving a complete look at the big picture before doing anything practical. Although this is the "better" method, as no dirty hacks have to be made, it can be very frustrating as well as energy- and time-consuming, which is why we've decided on the direct approach.

Note that even though this chapter tries to impart as much knowledge as possible about the inner workings of PHP, it's impossible to really give a complete guide to extending PHP that works 100% of the time in all cases. PHP is such a huge and complex package that its inner workings can only be understood if you make yourself familiar with it by practicing, so we encourage you to work with the source.

What Is Zend? and What Is PHP?

The name Zend refers to the language engine, PHP's core. The term PHP refers to the complete system as it appears from the outside. This might sound a bit confusing at first, but it's not that complicated (see Figure 24-1). To implement a Web script interpreter, you need three parts:

The interpreter part analyzes the input code, translates it, and executes it.
The functionality part implements the functionality of the language (its functions, etc.).
The interface part talks to the Web server, etc.

Zend takes part 1 completely and a bit of part 2; PHP takes parts 2 and 3. Together they form the complete PHP package. Zend itself really forms only the language core, implementing PHP at its very basics with some predefined functions. PHP contains all the modules that actually create the language's outstanding capabilities.

Figure 24-1. The internal structure of PHP.

The following sections discuss where PHP can be extended and how it's done.

Chapter 25. Extension Possibilities

As shown in Figure 24-1 above, PHP can be extended primarily at three points: external modules, built-in modules, and the Zend engine. The following sections discuss these options.

External Modules

External modules can be loaded at script runtime using the function dl(). This function loads a shared object from disk and makes its functionality available to the script to which it's being bound. After the script is terminated, the external module is discarded from memory. This method has both advantages and disadvantages, as described in the following table:

Advantages	Disadvantages
External modules don't require recompiling of PHP.	The shared objects need to be loaded every time a script is being executed (every hit), which is very slow.
The size of PHP remains small by "outsourcing" certain functionality.	External additional files clutter up the disk.
	Every script that wants to use an external module's functionality has to specifically include a call to dl(), or the `extension` tag in `php.ini` needs to be modified (which is not always a suitable solution).

To sum up, external modules are great for third-party products, small additions to PHP that are rarely used, or just for testing purposes. To develop additional functionality quickly, external modules provide the best results. For frequent usage, larger implementations, and complex code, the disadvantages outweigh the advantages.

Third parties might consider using the extension tag in php.ini to create additional external modules to PHP. These external modules are completely detached from the main package, which is a very handy feature in commercial environments. Commercial distributors can simply ship disks or archives containing only their additional modules, without the need to create fixed and solid PHP binaries that don't allow other modules to be bound to them.

Built-in Modules

Built-in modules are compiled directly into PHP and carried around with every PHP process; their functionality is instantly available to every script that's being run. Like external modules, built-in modules have advantages and disadvantages, as described in the following table:

Advantages	Disadvantages
No need to load the module specifically; the functionality is instantly available.	Changes to built-in modules require recompiling of PHP.
No external files clutter up the disk; everything resides in the PHP binary.	The PHP binary grows and consumes more memory.

Built-in modules are best when you have a solid library of functions that remains relatively unchanged, requires better than poor-to-average performance, or is used frequently by many scripts on your site. The need to recompile PHP is quickly compensated by the benefit in speed and ease of use. However, built-in modules are not ideal when rapid development of small additions is required.

The Zend Engine

Of course, extensions can also be implemented directly in the Zend engine. This strategy is good if you need a change in the language behavior or require special functions to be built directly into the language core. In general, however, modifications to the Zend engine should be avoided. Changes here result in incompatibilities with the rest of the world, and hardly anyone will ever adapt to specially patched Zend engines. Modifications can't be detached from the main PHP sources and are overridden with the next update using the "official" source repositories. Therefore, this method is generally considered bad practice and, due to its rarity, is not covered in this book.

Chapter 26. Source Layout

Note: Prior to working through the rest of this chapter, you should retrieve clean, unmodified source trees of your favorite Web server. We're working with Apache (available at http://www.apache.org/) and, of course, with PHP (available at http://www.php.net/ - does it need to be said?).
Make sure that you can compile a working PHP environment by yourself! We won't go into this issue here, however, as you should already have this most basic ability when studying this chapter.

Before we start discussing code issues, you should familiarize yourself with the source tree to be able to quickly navigate through PHP's files. This is a must-have ability to implement and debug extensions.

The following table describes the contents of the major directories.

Directory	Contents
`php4`	Main PHP source files and main header files; here you'll find all of PHP's API definitions, macros, etc. (important). Everything else is below this directory.
`php4/ext`	Repository for dynamic and built-in modules; by default, these are the "official" PHP modules that have been integrated into the main source tree. From PHP 4.0, it's possible to compile these standard extensions as dynamic loadable modules (at least, those that support it).
`php4/main`	This directory contains the main php macros and definitions. (important)
`php4/pear`	Directory for the PHP Extension and Application Repository. This directory contains core PEAR files.
`php4/sapi`	Contains the code for the different server abstraction layers.
`php4/TSRM`	Location of the "Thread Safe Resource Manager" (TSRM) for Zend and PHP.
`php4/Zend`	Location of the Zend Engine files; here you'll find all of Zend's API definitions, macros, etc. (important).

Discussing all the files included in the PHP package is beyond the scope of this chapter. However, you should take a close look at the following files:

php4/main/php.h, located in the main PHP directory. This file contains most of PHP's macro and API definitions.
php4/Zend/zend.h, located in the main Zend directory. This file contains most of Zend's macros and definitions.
php4/Zend/zend_API.h, also located in the Zend directory, which defines Zend's API.

You should also follow some sub-inclusions from these files; for example, the ones relating to the Zend executor, the PHP initialization file support, and such. After reading these files, take the time to navigate around the package a little to see the interdependencies of all files and modules - how they relate to each other and especially how they make use of each other. This also helps you to adapt to the coding style in which PHP is authored. To extend PHP, you should quickly adapt to this style.

Extension Conventions

Zend is built using certain conventions; to avoid breaking its standards, you should follow the rules described in the following sections.

Macros

For almost every important task, Zend ships predefined macros that are extremely handy. The tables and figures in the following sections describe most of the basic functions, structures, and macros. The macro definitions can be found mainly in zend.h and zend_API.h. We suggest that you take a close look at these files after having studied this chapter. (Although you can go ahead and read them now, not everything will make sense to you yet.)

Memory Management

Resource management is a crucial issue, especially in server software. One of the most valuable resources is memory, and memory management should be handled with extreme care. Memory management has been partially abstracted in Zend, and you should stick to this abstraction for obvious reasons: Due to the abstraction, Zend gets full control over all memory allocations. Zend is able to determine whether a block is in use, automatically freeing unused blocks and blocks with lost references, and thus prevent memory leaks. The functions to be used are described in the following table:

Function	Description
emalloc()	Serves as replacement for malloc().
efree()	Serves as replacement for free().
estrdup()	Serves as replacement for strdup().
estrndup()	Serves as replacement for strndup(). Faster than estrdup() and binary-safe. This is the recommended function to use if you know the string length prior to duplicating it.
ecalloc()	Serves as replacement for calloc().
erealloc()	Serves as replacement for realloc().

emalloc(), estrdup(), estrndup(), ecalloc(), and erealloc() allocate internal memory; efree() frees these previously allocated blocks. Memory handled by the e*() functions is considered local to the current process and is discarded as soon as the script executed by this process is terminated.

Warning

To allocate resident memory that survives termination of the current script, you can use malloc() and free(). This should only be done with extreme care, however, and only in conjunction with demands of the Zend API; otherwise, you risk memory leaks.

Zend also features a thread-safe resource manager to provide better native support for multithreaded Web servers. This requires you to allocate local structures for all of your global variables to allow concurrent threads to be run. Because the thread-safe mode of Zend was not finished back when this was written, it is not yet extensively covered here.

Directory and File Functions

The following directory and file functions should be used in Zend modules. They behave exactly like their C counterparts, but provide virtual working directory support on the thread level.

Zend Function	Regular C Function
V_GETCWD()	getcwd()
V_FOPEN()	fopen()
V_OPEN()	open()
V_CHDIR()	chdir()
V_GETWD()	getwd()
V_CHDIR_FILE()	Takes a file path as an argument and changes the current working directory to that file's directory.
V_STAT()	stat()
V_LSTAT()	lstat()

String Handling

Strings are handled a bit differently by the Zend engine than other values such as integers, Booleans, etc., which don't require additional memory allocation for storing their values. If you want to return a string from a function, introduce a new string variable to the symbol table, or do something similar, you have to make sure that the memory the string will be occupying has previously been allocated, using the aforementioned e*() functions for allocation. (This might not make much sense to you yet; just keep it somewhere in your head for now - we'll get back to it shortly.)

Complex Types

Complex types such as arrays and objects require different treatment. Zend features a single API for these types - they're stored using hash tables.

Note: To reduce complexity in the following source examples, we're only working with simple types such as integers at first. A discussion about creating more advanced types follows later in this chapter.

Chapter 27. PHP's Automatic Build System

PHP 4 features an automatic build system that's very flexible. All modules reside in a subdirectory of the ext directory. In addition to its own sources, each module consists of a config.m4 file, for extension configuration. (for example, see http://www.gnu.org/manual/m4/html_mono/m4.html)

All these stub files are generated automatically, along with .cvsignore, by a little shell script named ext_skel that resides in the ext directory. As argument it takes the name of the module that you want to create. The shell script then creates a directory of the same name, along with the appropriate stub files.

Step by step, the process looks like this:
:~/cvs/php4/ext:> ./ext_skel --extname=my_module Creating directory my_module Creating basic files: config.m4 .cvsignore my_module.c php_my_module.h CREDITS EXPERIMENTAL tests/001.phpt my_module.php [done]. To use your new extension, you will have to execute the following steps: 1. $ cd .. 2. $ vi ext/my_module/config.m4 3. $ ./buildconf 4. $ ./configure --[with|enable]-my_module 5. $ make 6. $ ./php -f ext/my_module/my_module.php 7. $ vi ext/my_module/my_module.c 8. $ make Repeat steps 3-6 until you are satisfied with ext/my_module/config.m4 and step 6 confirms that your module is compiled into PHP. Then, start writing code and repeat the last two steps as often as necessary.
This instruction creates the aforementioned files. To include the new module in the automatic configuration and build process, you have to run buildconf, which regenerates the configure script by searching through the ext directory and including all found config.m4 files.

The default config.m4 shown in Example 27-1 is a bit more complex:

Example 27-1. The default config.m4.

dnl $Id: Extending_Zend_Build.xml,v 1.8 2002/10/10 18:13:11 imajes Exp $
dnl config.m4 for extension my_module

dnl Comments in this file start with the string 'dnl'.
dnl Remove where necessary. This file will not work
dnl without editing.

dnl If your extension references something external, use with:

dnl PHP_ARG_WITH(my_module, for my_module support,
dnl Make sure that the comment is aligned:
dnl [  --with-my_module             Include my_module support])

dnl Otherwise use enable:

dnl PHP_ARG_ENABLE(my_module, whether to enable my_module support,
dnl Make sure that the comment is aligned:
dnl [  --enable-my_module           Enable my_module support])

if test "$PHP_MY_MODULE" != "no"; then
  dnl Write more examples of tests here...

  dnl # --with-my_module -> check with-path
  dnl SEARCH_PATH="/usr/local /usr"     # you might want to change this
  dnl SEARCH_FOR="/include/my_module.h"  # you most likely want to change this
  dnl if test -r $PHP_MY_MODULE/; then # path given as parameter
  dnl   MY_MODULE_DIR=$PHP_MY_MODULE
  dnl else # search default path list
  dnl   AC_MSG_CHECKING([for my_module files in default path])
  dnl   for i in $SEARCH_PATH ; do
  dnl     if test -r $i/$SEARCH_FOR; then
  dnl       MY_MODULE_DIR=$i
  dnl       AC_MSG_RESULT(found in $i)
  dnl     fi
  dnl   done
  dnl fi
  dnl
  dnl if test -z "$MY_MODULE_DIR"; then
  dnl   AC_MSG_RESULT([not found])
  dnl   AC_MSG_ERROR([Please reinstall the my_module distribution])
  dnl fi

  dnl # --with-my_module -> add include path
  dnl PHP_ADD_INCLUDE($MY_MODULE_DIR/include)

  dnl # --with-my_module -> chech for lib and symbol presence
  dnl LIBNAME=my_module # you may want to change this
  dnl LIBSYMBOL=my_module # you most likely want to change this 

  dnl PHP_CHECK_LIBRARY($LIBNAME,$LIBSYMBOL,
  dnl [
  dnl   PHP_ADD_LIBRARY_WITH_PATH($LIBNAME, $MY_MODULE_DIR/lib, MY_MODULE_SHARED_LIBADD)
  dnl   AC_DEFINE(HAVE_MY_MODULELIB,1,[ ])
  dnl ],[
  dnl   AC_MSG_ERROR([wrong my_module lib version or lib not found])
  dnl ],[
  dnl   -L$MY_MODULE_DIR/lib -lm -ldl
  dnl ])
  dnl
  dnl PHP_SUBST(MY_MODULE_SHARED_LIBADD)

  PHP_NEW_EXTENSION(my_module, my_module.c, $ext_shared)
fi

If you're unfamiliar with M4 files (now is certainly a good time to get familiar), this might be a bit confusing at first; but it's actually quite easy.

Note: Everything prefixed with dnl is treated as a comment and is not parsed.

The config.m4 file is responsible for parsing the command-line options passed to configure at configuration time. This means that it has to check for required external files and do similar configuration and setup tasks.

The default file creates two configuration directives in the configure script: --with-my_module and --enable-my_module. Use the first option when referring external files (such as the --with-apache directive that refers to the Apache directory). Use the second option when the user simply has to decide whether to enable your extension. Regardless of which option you use, you should uncomment the other, unnecessary one; that is, if you're using --enable-my_module, you should remove support for --with-my_module, and vice versa.

By default, the config.m4 file created by ext_skel accepts both directives and automatically enables your extension. Enabling the extension is done by using the PHP_EXTENSION macro. To change the default behavior to include your module into the PHP binary when desired by the user (by explicitly specifying --enable-my_module or --with-my_module), change the test for $PHP_MY_MODULE to == "yes":
if test "$PHP_MY_MODULE" == "yes"; then dnl Action.. PHP_EXTENSION(my_module, $ext_shared) fi
This would require you to use --enable-my_module each time when reconfiguring and recompiling PHP.

Note: Be sure to run buildconf every time you change config.m4!

We'll go into more details on the M4 macros available to your configuration scripts later in this chapter. For now, we'll simply use the default files.

Chapter 28. Creating Extensions

We'll start with the creation of a very simple extension at first, which basically does nothing more than implement a function that returns the integer it receives as parameter. Example 28-1 shows the source.

Example 28-1. A simple extension.

/* include standard header */
#include "php.h"

/* declaration of functions to be exported */
ZEND_FUNCTION(first_module);

/* compiled function list so Zend knows what's in this module */
zend_function_entry firstmod_functions[] =
{
    ZEND_FE(first_module, NULL)
    {NULL, NULL, NULL}
};

/* compiled module information */
zend_module_entry firstmod_module_entry =
{
    STANDARD_MODULE_HEADER,
    "First Module",
    firstmod_functions,
    NULL, 
    NULL, 
    NULL, 
    NULL, 
    NULL,
    NO_VERSION_YET,
    STANDARD_MODULE_PROPERTIES
};

/* implement standard "stub" routine to introduce ourselves to Zend */
#if COMPILE_DL_FIRST_MODULE
ZEND_GET_MODULE(firstmod)
#endif

/* implement function that is meant to be made available to PHP */
ZEND_FUNCTION(first_module)
{
    long parameter;

    if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "l", &parameter) == FAILURE) {
        return;
    }

    RETURN_LONG(parameter);
}

This code contains a complete PHP module. We'll explain the source code in detail shortly, but first we'd like to discuss the build process. (This will allow the impatient to experiment before we dive into API discussions.)

Note: The example source makes use of some features introduced with the Zend version used in PHP 4.1.0 and above, it won't compile with older PHP 4.0.x versions.

Compiling Modules

There are basically two ways to compile modules:

Use the provided "make" mechanism in the ext directory, which also allows building of dynamic loadable modules.
Compile the sources manually.

The first method should definitely be favored, since, as of PHP 4.0, this has been standardized into a sophisticated build process. The fact that it is so sophisticated is also its drawback, unfortunately - it's hard to understand at first. We'll provide a more detailed introduction to this later in the chapter, but first let's work with the default files.

The second method is good for those who (for some reason) don't have the full PHP source tree available, don't have access to all files, or just like to juggle with their keyboard. These cases should be extremely rare, but for the sake of completeness we'll also describe this method.

Compiling Using Make. To compile the sample sources using the standard mechanism, copy all their subdirectories to the ext directory of your PHP source tree. Then run buildconf, which will create an updated configure script containing appropriate options for the new extension. By default, all the sample sources are disabled, so you don't have to fear breaking your build process.

After you run buildconf, configure --help shows the following additional modules:

--enable-array_experiments   BOOK: Enables array experiments
  --enable-call_userland       BOOK: Enables userland module
  --enable-cross_conversion    BOOK: Enables cross-conversion module
  --enable-first_module        BOOK: Enables first module
  --enable-infoprint           BOOK: Enables infoprint module
  --enable-reference_test      BOOK: Enables reference test module
  --enable-resource_test       BOOK: Enables resource test module
  --enable-variable_creation   BOOK: Enables variable-creation module

The module shown earlier in Example 28-1 can be enabled with --enable-first_module or --enable-first_module=yes.

Compiling Manually. To compile your modules manually, you need the following commands:

Action	Command
Compiling	cc -fpic -DCOMPILE_DL=1 -I/usr/local/include -I. -I.. -I../Zend -c -o `<your_object_file>` `<your_c_file>`
Linking	cc -shared -L/usr/local/lib -rdynamic -o `<your_module_file>` `<your_object_file(s)>`

The command to compile the module simply instructs the compiler to generate position-independent code (-fpic shouldn't be omitted) and additionally defines the constant COMPILE_DL to tell the module code that it's compiled as a dynamically loadable module (the test module above checks for this; we'll discuss it shortly). After these options, it specifies a number of standard include paths that should be used as the minimal set to compile the source files.

Note: All include paths in the example are relative to the directory ext. If you're compiling from another directory, change the pathnames accordingly. Required items are the PHP directory, the Zend directory, and (if necessary), the directory in which your module resides.

The link command is also a plain vanilla command instructing linkage as a dynamic module.

You can include optimization options in the compilation command, although these have been omitted in this example (but some are included in the makefile template described in an earlier section).

Note: Compiling and linking manually as a static module into the PHP binary involves very long instructions and thus is not discussed here. (It's not very efficient to type all those commands.)

Chapter 29. Using Extensions

Depending on the build process you selected, you should either end up with a new PHP binary to be linked into your Web server (or run as CGI), or with an .so (shared object) file. If you compiled the example file first_module.c as a shared object, your result file should be first_module.so. To use it, you first have to copy it to a place from which it's accessible to PHP. For a simple test procedure, you can copy it to your htdocs directory and try it with the source in Example 29-1. If you compiled it into the PHP binary, omit the call to dl(), as the module's functionality is instantly available to your scripts.

Warning

For security reasons, you should not put your dynamic modules into publicly accessible directories. Even though it can be done and it simplifies testing, you should put them into a separate directory in production environments.

Example 29-1. A test file for first_module.so.

<?php
    
// remove next comment if necessary
// dl("first_module.so"); 

$param = 2;
$return = first_module($param);

print("We sent '$param' and got '$return'");

?>

Calling this PHP file in your Web browser should give you the output shown in Figure 29-1.

Figure 29-1. Output of first_module.php.

If required, the dynamic loadable module is loaded by calling the dl() function. This function looks for the specified shared object, loads it, and makes its functions available to PHP. The module exports the function first_module(), which accepts a single parameter, converts it to an integer, and returns the result of the conversion.

If you've gotten this far, congratulations! You just built your first extension to PHP.

Chapter 30. Troubleshooting

Actually, not much troubleshooting can be done when compiling static or dynamic modules. The only problem that could arise is that the compiler will complain about missing definitions or something similar. In this case, make sure that all header files are available and that you specified their path correctly in the compilation command. To be sure that everything is located correctly, extract a clean PHP source tree and use the automatic build in the ext directory with the fresh files; this will guarantee a safe compilation environment. If this fails, try manual compilation.

PHP might also complain about missing functions in your module. (This shouldn't happen with the sample sources if you didn't modify them.) If the names of external functions you're trying to access from your module are misspelled, they'll remain as "unlinked symbols" in the symbol table. During dynamic loading and linkage by PHP, they won't resolve because of the typing errors - there are no corresponding symbols in the main binary. Look for incorrect declarations in your module file or incorrectly written external references. Note that this problem is specific to dynamic loadable modules; it doesn't occur with static modules. Errors in static modules show up at compile time.

Chapter 31. Source Discussion

Now that you've got a safe build environment and you're able to include the modules into PHP files, it's time to discuss how everything works.

Module Structure

All PHP modules follow a common structure:

Header file inclusions (to include all required macros, API definitions, etc.)
C declaration of exported functions (required to declare the Zend function block)
Declaration of the Zend function block
Declaration of the Zend module block
Implementation of get_module()
Implementation of all exported functions

Header File Inclusions

The only header file you really have to include for your modules is php.h, located in the PHP directory. This file makes all macros and API definitions required to build new modules available to your code.

Tip: It's good practice to create a separate header file for your module that contains module-specific definitions. This header file should contain all the forward definitions for exported functions and include php.h. If you created your module using ext_skel you already have such a header file prepared.

Declaring Exported Functions

To declare functions that are to be exported (i.e., made available to PHP as new native functions), Zend provides a set of macros. A sample declaration looks like this:
ZEND_FUNCTION ( my_function );

ZEND_FUNCTION declares a new C function that complies with Zend's internal API. This means that the function is of type void and accepts INTERNAL_FUNCTION_PARAMETERS (another macro) as parameters. Additionally, it prefixes the function name with zif. The immediately expanded version of the above definitions would look like this:
void zif_my_function ( INTERNAL_FUNCTION_PARAMETERS );
Expanding INTERNAL_FUNCTION_PARAMETERS results in the following:
void zif_my_function( int ht , zval * return_value , zval * this_ptr , int return_value_used , zend_executor_globals * executor_globals );

Since the interpreter and executor core have been separated from the main PHP package, a second API defining macros and function sets has evolved: the Zend API. As the Zend API now handles quite a few of the responsibilities that previously belonged to PHP, a lot of PHP functions have been reduced to macros aliasing to calls into the Zend API. The recommended practice is to use the Zend API wherever possible, as the old API is only preserved for compatibility reasons. For example, the types zval and pval are identical. zval is Zend's definition; pval is PHP's definition (actually, pval is an alias for zval now). As the macro INTERNAL_FUNCTION_PARAMETERS is a Zend macro, the above declaration contains zval. When writing code, you should always use zval to conform to the new Zend API.

The parameter list of this declaration is very important; you should keep these parameters in mind (see Table 31-1 for descriptions).

Table 31-1. Zend's Parameters to Functions Called from PHP

Parameter	Description
`ht`	The number of arguments passed to the Zend function. You should not touch this directly, but instead use ZEND_NUM_ARGS() to obtain the value.
`return_value`	This variable is used to pass any return values of your function back to PHP. Access to this variable is best done using the predefined macros. For a description of these see below.
`this_ptr`	Using this variable, you can gain access to the object in which your function is contained, if it's used within an object. Use the function getThis() to obtain this pointer.
`return_value_used`	This flag indicates whether an eventual return value from this function will actually be used by the calling script. `0` indicates that the return value is not used; `1` indicates that the caller expects a return value. Evaluation of this flag can be done to verify correct usage of the function as well as speed optimizations in case returning a value requires expensive operations (for an example, see how `array.c` makes use of this).
`executor_globals`	This variable points to global settings of the Zend engine. You'll find this useful when creating new variables, for example (more about this later). The executor globals can also be introduced to your function by using the macro `TSRMLS_FETCH()`.

Declaration of the Zend Function Block

Now that you have declared the functions to be exported, you also have to introduce them to Zend. Introducing the list of functions is done by using an array of zend_function_entry. This array consecutively contains all functions that are to be made available externally, with the function's name as it should appear in PHP and its name as defined in the C source. Internally, zend_function_entry is defined as shown in Example 31-1.

Example 31-1. Internal declaration of zend_function_entry.
typedef struct _zend_function_entry { char *fname; void (*handler)(INTERNAL_FUNCTION_PARAMETERS); unsigned char *func_arg_types; } zend_function_entry;
Entry Description
fname Denotes the function name as seen in PHP (for example, fopen, mysql_connect, or, in our example, first_module).
handler Pointer to the C function responsible for handling calls to this function. For example, see the standard macro INTERNAL_FUNCTION_PARAMETERS discussed earlier.
func_arg_types Allows you to mark certain parameters so that they're forced to be passed by reference. You usually should set this to NULL.
In the example above, the declaration looks like this:
zend_function_entry firstmod_functions[] = { ZEND_FE(first_module, NULL) {NULL, NULL, NULL} };
You can see that the last entry in the list always has to be {NULL, NULL, NULL}. This marker has to be set for Zend to know when the end of the list of exported functions is reached.

Note: You cannot use the predefined macros for the end marker, as these would try to refer to a function named "NULL"!

The macro ZEND_FE (short for 'Zend Function Entry') simply expands to a structure entry in zend_function_entry. Note that these macros introduce a special naming scheme to your functions - your C functions will be prefixed with zif_, meaning that ZEND_FE(first_module) will refer to a C function zif_first_module(). If you want to mix macro usage with hand-coded entries (not a good practice), keep this in mind.

Tip: Compilation errors that refer to functions named zif_*() relate to functions defined with ZEND_FE.

Table 31-2 shows a list of all the macros that you can use to define functions.

Table 31-2. Macros for Defining Functions

Macro Name	Description
`ZEND_FE(name, arg_types)`	Defines a function entry of the name `name` in `zend_function_entry`. Requires a corresponding C function. `arg_types` needs to be set to `NULL`. This function uses automatic C function name generation by prefixing the PHP function name with `zif_`. For example, `ZEND_FE("first_module", NULL)` introduces a function first_module() to PHP and links it to the C function zif_first_module(). Use in conjunction with `ZEND_FUNCTION`.
`ZEND_NAMED_FE(php_name, name, arg_types)`	Defines a function that will be available to PHP by the name `php_name` and links it to the corresponding C function `name`. `arg_types` needs to be set to `NULL`. Use this function if you don't want the automatic name prefixing introduced by `ZEND_FE`. Use in conjunction with `ZEND_NAMED_FUNCTION`.
`ZEND_FALIAS(name, alias, arg_types)`	Defines an alias named `alias` for `name`. `arg_types` needs to be set to `NULL`. Doesn't require a corresponding C function; refers to the alias target instead.
`PHP_FE(name, arg_types)`	Old PHP API equivalent of `ZEND_FE`.
`PHP_NAMED_FE(runtime_name, name, arg_types)`	Old PHP API equivalent of `ZEND_NAMED_FE`.

Note: You can't use ZEND_FE in conjunction with PHP_FUNCTION, or PHP_FE in conjunction with ZEND_FUNCTION. However, it's perfectly legal to mix ZEND_FE and ZEND_FUNCTION with PHP_FE and PHP_FUNCTION when staying with the same macro set for each function to be declared. But mixing is not recommended; instead, you're advised to use the ZEND_* macros only.

Declaration of the Zend Module Block

This block is stored in the structure zend_module_entry and contains all necessary information to describe the contents of this module to Zend. You can see the internal definition of this module in Example 31-2.

Example 31-2. Internal declaration of zend_module_entry.

typedef struct _zend_module_entry zend_module_entry;
     
    struct _zend_module_entry {
    unsigned short size;
    unsigned int zend_api;
    unsigned char zend_debug;
    unsigned char zts;
    char *name;
    zend_function_entry *functions;
    int (*module_startup_func)(INIT_FUNC_ARGS);
    int (*module_shutdown_func)(SHUTDOWN_FUNC_ARGS);
    int (*request_startup_func)(INIT_FUNC_ARGS);
    int (*request_shutdown_func)(SHUTDOWN_FUNC_ARGS);
    void (*info_func)(ZEND_MODULE_INFO_FUNC_ARGS);
    char *version;
    int (*global_startup_func)(void);
    int (*global_shutdown_func)(void);

[ Rest of the structure is not interesting here ]

};

Entry	Description
`size`, `zend_api`, `zend_debug` and `zts`	Usually filled with the `"STANDARD_MODULE_HEADER"`, which fills these four members with the size of the whole zend_module_entry, the `ZEND_MODULE_API_NO`, whether it is a debug build or normal build (`ZEND_DEBUG`) and if ZTS is enabled (`USING_ZTS`).
`name`	Contains the module name (for example, `"File functions"`, `"Socket functions"`, `"Crypt"`, etc.). This name will show up in phpinfo(), in the section "Additional Modules."
`functions`	Points to the Zend function block, discussed in the preceding section.
`module_startup_func`	This function is called once upon module initialization and can be used to do one-time initialization steps (such as initial memory allocation, etc.). To indicate a failure during initialization, return `FAILURE`; otherwise, `SUCCESS`. To mark this field as unused, use `NULL`. To declare a function, use the macro `ZEND_MINIT`.
`module_shutdown_func`	This function is called once upon module shutdown and can be used to do one-time deinitialization steps (such as memory deallocation). This is the counterpart to module_startup_func(). To indicate a failure during deinitialization, return `FAILURE`; otherwise, `SUCCESS`. To mark this field as unused, use `NULL`. To declare a function, use the macro `ZEND_MSHUTDOWN`.
`request_startup_func`	This function is called once upon every page request and can be used to do one-time initialization steps that are required to process a request. To indicate a failure here, return `FAILURE`; otherwise, `SUCCESS`. Note: As dynamic loadable modules are loaded only on page requests, the request startup function is called right after the module startup function (both initialization events happen at the same time). To mark this field as unused, use `NULL`. To declare a function, use the macro `ZEND_RINIT`.
`request_shutdown_func`	This function is called once after every page request and works as counterpart to request_startup_func(). To indicate a failure here, return `FAILURE`; otherwise, `SUCCESS`. Note: As dynamic loadable modules are loaded only on page requests, the request shutdown function is immediately followed by a call to the module shutdown handler (both deinitialization events happen at the same time). To mark this field as unused, use `NULL`. To declare a function, use the macro `ZEND_RSHUTDOWN`.
`info_func`	When phpinfo() is called in a script, Zend cycles through all loaded modules and calls this function. Every module then has the chance to print its own "footprint" into the output page. Generally this is used to dump environmental or statistical information. To mark this field as unused, use `NULL`. To declare a function, use the macro `ZEND_MINFO`.
`version`	The version of the module. You can use `NO_VERSION_YET` if you don't want to give the module a version number yet, but we really recommend that you add a version string here. Such a version string can look like this (in chronological order): `"2.5-dev"`, `"2.5RC1"`, `"2.5"` or `"2.5pl3"`.
Remaining structure elements	These are used internally and can be prefilled by using the macro `STANDARD_MODULE_PROPERTIES_EX`. You should not assign any values to them. Use `STANDARD_MODULE_PROPERTIES_EX` only if you use global startup and shutdown functions; otherwise, use `STANDARD_MODULE_PROPERTIES` directly.

In our example, this structure is implemented as follows:
zend_module_entry firstmod_module_entry = { STANDARD_MODULE_HEADER, "First Module", firstmod_functions, NULL, NULL, NULL, NULL, NULL, NO_VERSION_YET, STANDARD_MODULE_PROPERTIES, };
This is basically the easiest and most minimal set of values you could ever use. The module name is set to First Module, then the function list is referenced, after which all startup and shutdown functions are marked as being unused.

For reference purposes, you can find a list of the macros involved in declared startup and shutdown functions in Table 31-3. These are not used in our basic example yet, but will be demonstrated later on. You should make use of these macros to declare your startup and shutdown functions, as these require special arguments to be passed (INIT_FUNC_ARGS and SHUTDOWN_FUNC_ARGS), which are automatically included into the function declaration when using the predefined macros. If you declare your functions manually and the PHP developers decide that a change in the argument list is necessary, you'll have to change your module sources to remain compatible.

Table 31-3. Macros to Declare Startup and Shutdown Functions

Macro	Description
`ZEND_MINIT(module)`	Declares a function for module startup. The generated name will be `zend_minit_<module>` (for example, `zend_minit_first_module`). Use in conjunction with `ZEND_MINIT_FUNCTION`.
`ZEND_MSHUTDOWN(module)`	Declares a function for module shutdown. The generated name will be `zend_mshutdown_<module>` (for example, `zend_mshutdown_first_module`). Use in conjunction with `ZEND_MSHUTDOWN_FUNCTION`.
`ZEND_RINIT(module)`	Declares a function for request startup. The generated name will be `zend_rinit_<module>` (for example, `zend_rinit_first_module`). Use in conjunction with `ZEND_RINIT_FUNCTION`.
`ZEND_RSHUTDOWN(module)`	Declares a function for request shutdown. The generated name will be `zend_rshutdown_<module>` (for example, `zend_rshutdown_first_module`). Use in conjunction with `ZEND_RSHUTDOWN_FUNCTION`.
`ZEND_MINFO(module)`	Declares a function for printing module information, used when phpinfo() is called. The generated name will be `zend_info_<module>` (for example, `zend_info_first_module`). Use in conjunction with `ZEND_MINFO_FUNCTION`.

Creation of get_module()

This function is special to all dynamic loadable modules. Take a look at the creation via the ZEND_GET_MODULE macro first:

#if COMPILE_DL_FIRSTMOD
     ZEND_GET_MODULE(firstmod) 
#endif

The function implementation is surrounded by a conditional compilation statement. This is needed since the function get_module() is only required if your module is built as a dynamic extension. By specifying a definition of COMPILE_DL_FIRSTMOD in the compiler command (see above for a discussion of the compilation instructions required to build a dynamic extension), you can instruct your module whether you intend to build it as a dynamic extension or as a built-in module. If you want a built-in module, the implementation of get_module() is simply left out.

get_module() is called by Zend at load time of the module. You can think of it as being invoked by the dl() call in your script. Its purpose is to pass the module information block back to Zend in order to inform the engine about the module contents.

If you don't implement a get_module() function in your dynamic loadable module, Zend will compliment you with an error message when trying to access it.

Implementation of All Exported Functions

Implementing the exported functions is the final step. The example function in first_module looks like this:
ZEND_FUNCTION(first_module) { long parameter; if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "l", &parameter) == FAILURE) { return; } RETURN_LONG(parameter); }
The function declaration is done using ZEND_FUNCTION, which corresponds to ZEND_FE in the function entry table (discussed earlier).

After the declaration, code for checking and retrieving the function's arguments, argument conversion, and return value generation follows (more on this later).

Summary

That's it, basically - there's nothing more to implementing PHP modules. Built-in modules are structured similarly to dynamic modules, so, equipped with the information presented in the previous sections, you'll be able to fight the odds when encountering PHP module source files.

Now, in the following sections, read on about how to make use of PHP's internals to build powerful extensions.

Chapter 32. Accepting Arguments

One of the most important issues for language extensions is accepting and dealing with data passed via arguments. Most extensions are built to deal with specific input data (or require parameters to perform their specific actions), and function arguments are the only real way to exchange data between the PHP level and the C level. Of course, there's also the possibility of exchanging data using predefined global values (which is also discussed later), but this should be avoided by all means, as it's extremely bad practice.

PHP doesn't make use of any formal function declarations; this is why call syntax is always completely dynamic and never checked for errors. Checking for correct call syntax is left to the user code. For example, it's possible to call a function using only one argument at one time and four arguments the next time - both invocations are syntactically absolutely correct.

Determining the Number of Arguments

Since PHP doesn't have formal function definitions with support for call syntax checking, and since PHP features variable arguments, sometimes you need to find out with how many arguments your function has been called. You can use the ZEND_NUM_ARGS macro in this case. In previous versions of PHP, this macro retrieved the number of arguments with which the function has been called based on the function's hash table entry, ht, which is passed in the INTERNAL_FUNCTION_PARAMETERS list. As ht itself now contains the number of arguments that have been passed to the function, ZEND_NUM_ARGS has been stripped down to a dummy macro (see its definition in zend_API.h). But it's still good practice to use it, to remain compatible with future changes in the call interface. Note: The old PHP equivalent of this macro is ARG_COUNT.

The following code checks for the correct number of arguments:
if(ZEND_NUM_ARGS() != 2) WRONG_PARAM_COUNT;
If the function is not called with two arguments, it exits with an error message. The code snippet above makes use of the tool macro WRONG_PARAM_COUNT, which can be used to generate a standard error message (see Figure 32-1).

Figure 32-1. WRONG_PARAM_COUNT in action.

This macro prints a default error message and then returns to the caller. Its definition can also be found in zend_API.h and looks like this:
ZEND_API void wrong_param_count(void); #define WRONG_PARAM_COUNT { wrong_param_count(); return; }
As you can see, it calls an internal function named wrong_param_count() that's responsible for printing the warning. For details on generating customized error messages, see the later section "Printing Information."

Retrieving Arguments

New parameter parsing API: This chapter documents the new Zend parameter parsing API introduced by Andrei Zmievski. It was introduced in the development stage between PHP 4.0.6 and 4.1.0 .

Parsing parameters is a very common operation and it may get a bit tedious. It would also be nice to have standardized error checking and error messages. Since PHP 4.1.0, there is a way to do just that by using the new parameter parsing API. It greatly simplifies the process of receiving parameteres, but it has a drawback in that it can't be used for functions that expect variable number of parameters. But since the vast majority of functions do not fall into those categories, this parsing API is recommended as the new standard way.

The prototype for parameter parsing function looks like this:
int zend_parse_parameters(int num_args TSRMLS_DC, char *type_spec, ...);
The first argument to this function is supposed to be the number of actual parameters passed to your function, so ZEND_NUM_ARGS() can be used for that. The second parameter should always be TSRMLS_CC macro. The third argument is a string that specifies the number and types of arguments your function is expecting, similar to how printf format string specifies the number and format of the output values it should operate on. And finally the rest of the arguments are pointers to variables which should receive the values from the parameters.

zend_parse_parameters() also performs type conversions whenever possible, so that you always receive the data in the format you asked for. Any type of scalar can be converted to another one, but conversions between complex types (arrays, objects, and resources) and scalar types are not allowed.

If the parameters could be obtained successfully and there were no errors during type conversion, the function will return SUCCESS, otherwise it will return FAILURE. The function will output informative error messages, if the number of received parameters does not match the requested number, or if type conversion could not be performed.

Here are some sample error messages:
Warning - ini_get_all() requires at most 1 parameter, 2 given Warning - wddx_deserialize() expects parameter 1 to be string, array given
Of course each error message is accompanied by the filename and line number on which it occurs.

Here is the full list of type specifiers:

l - long
d - double
s - string (with possible null bytes) and its length
b - boolean
r - resource, stored in zval*
a - array, stored in zval*
o - object (of any class), stored in zval*
O - object (of class specified by class entry), stored in zval*
z - the actual zval*

The following characters also have a meaning in the specifier string:

| - indicates that the remaining parameters are optional. The storage variables corresponding to these parameters should be initialized to default values by the extension, since they will not be touched by the parsing function if the parameters are not passed.
/ - the parsing function will call SEPARATE_ZVAL_IF_NOT_REF() on the parameter it follows, to provide a copy of the parameter, unless it's a reference.
! - the parameter it follows can be of specified type or NULL (only applies to a, o, O, r, and z). If NULL value is passed by the user, the storage pointer will be set to NULL.

The best way to illustrate the usage of this function is through examples:
/* Gets a long, a string and its length, and a zval. */ long l; char *s; int s_len; zval *param; if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "lsz", &l, &s, &s_len, &param) == FAILURE) { return; } /* Gets an object of class specified by my_ce, and an optional double. */ zval *obj; double d = 0.5; if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "O|d", &obj, my_ce, &d) == FAILURE) { return; } /* Gets an object or null, and an array. If null is passed for object, obj will be set to NULL. */ zval *obj; zval *arr; if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "O!a", &obj, &arr) == FAILURE) { return; } /* Gets a separated array. */ zval *arr; if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "a/", &arr) == FAILURE) { return; } /* Get only the first three parameters (useful for varargs functions). */ zval *z; zend_bool b; zval *r; if (zend_parse_parameters(3, "zbr!", &z, &b, &r) == FAILURE) { return; }

Note that in the last example we pass 3 for the number of received parameters, instead of ZEND_NUM_ARGS(). What this lets us do is receive the least number of parameters if our function expects a variable number of them. Of course, if you want to operate on the rest of the parameters, you will have to use zend_get_parameters_array_ex() to obtain them.

The parsing function has an extended version that allows for an additional flags argument that controls its actions.
int zend_parse_parameters_ex(int flags, int num_args TSRMLS_DC, char *type_spec, ...);

The only flag you can pass currently is ZEND_PARSE_PARAMS_QUIET, which instructs the function to not output any error messages during its operation. This is useful for functions that expect several sets of completely different arguments, but you will have to output your own error messages.

For example, here is how you would get either a set of three longs or a string:
long l1, l2, l3; char *s; if (zend_parse_parameters_ex(ZEND_PARSE_PARAMS_QUIET, ZEND_NUM_ARGS() TSRMLS_CC, "lll", &l1, &l2, &l3) == SUCCESS) { /* manipulate longs */ } else if (zend_parse_parameters_ex(ZEND_PARSE_PARAMS_QUIET, ZEND_NUM_ARGS(), "s", &s, &s_len) == SUCCESS) { /* manipulate string */ } else { php_error(E_WARNING, "%s() takes either three long values or a string as argument", get_active_function_name(TSRMLS_C)); return; }

With all the abovementioned ways of receiving function parameters you should have a good handle on this process. For even more example, look through the source code for extensions that are shipped with PHP - they illustrate every conceivable situation.

Old way of retrieving arguments (deprecated)

Deprecated parameter parsing API: This API is deprecated and superseded by the new ZEND parameter parsing API.

After having checked the number of arguments, you need to get access to the arguments themselves. This is done with the help of zend_get_parameters_ex():
zval **parameter; if(zend_get_parameters_ex(1, &parameter) != SUCCESS) WRONG_PARAM_COUNT;
All arguments are stored in a zval container, which needs to be pointed to twice. The snippet above tries to retrieve one argument and make it available to us via the parameter pointer.

zend_get_parameters_ex() accepts at least two arguments. The first argument is the number of arguments to retrieve (which should match the number of arguments with which the function has been called; this is why it's important to check for correct call syntax). The second argument (and all following arguments) are pointers to pointers to pointers to zvals. (Confusing, isn't it?) All these pointers are required because Zend works internally with **zval; to adjust a local **zval in our function,zend_get_parameters_ex() requires a pointer to it.

The return value of zend_get_parameters_ex() can either be SUCCESS or FAILURE, indicating (unsurprisingly) success or failure of the argument processing. A failure is most likely related to an incorrect number of arguments being specified, in which case you should exit with WRONG_PARAM_COUNT.

To retrieve more than one argument, you can use a similar snippet:
zval **param1, **param2, **param3, **param4; if(zend_get_parameters_ex(4, &param1, &param2, &param3, &param4) != SUCCESS) WRONG_PARAM_COUNT;

zend_get_parameters_ex() only checks whether you're trying to retrieve too many parameters. If the function is called with five arguments, but you're only retrieving three of them with zend_get_parameters_ex(), you won't get an error but will get the first three parameters instead. Subsequent calls of zend_get_parameters_ex() won't retrieve the remaining arguments, but will get the same arguments again.

Dealing with a Variable Number of Arguments/Optional Parameters

If your function is meant to accept a variable number of arguments, the snippets just described are sometimes suboptimal solutions. You have to create a line calling zend_get_parameters_ex() for every possible number of arguments, which is often unsatisfying.

For this case, you can use the function zend_get_parameters_array_ex(), which accepts the number of parameters to retrieve and an array in which to store them:
zval **parameter_array[4]; /* get the number of arguments */ argument_count = ZEND_NUM_ARGS(); /* see if it satisfies our minimal request (2 arguments) */ /* and our maximal acceptance (4 arguments) */ if(argument_count < 2 || argument_count > 5) WRONG_PARAM_COUNT; /* argument count is correct, now retrieve arguments */ if(zend_get_parameters_array_ex(argument_count, parameter_array) != SUCCESS) WRONG_PARAM_COUNT;
First, the number of arguments is checked to make sure that it's in the accepted range. After that, zend_get_parameters_array_ex() is used to fill parameter_array with valid pointers to the argument values.

A very clever implementation of this can be found in the code handling PHP's fsockopen() located in ext/standard/fsock.c, as shown in Example 32-1. Don't worry if you don't know all the functions used in this source yet; we'll get to them shortly.

Example 32-1. PHP's implementation of variable arguments in fsockopen().

pval **args[5];
int *sock=emalloc(sizeof(int));
int *sockp;
int arg_count=ARG_COUNT(ht);
int socketd = -1;
unsigned char udp = 0;
struct timeval timeout = { 60, 0 };
unsigned short portno;
unsigned long conv;
char *key = NULL;
FLS_FETCH();

if (arg_count > 5 || arg_count < 2 || zend_get_parameters_array_ex(arg_count,args)==FAILURE) {
    CLOSE_SOCK(1);
    WRONG_PARAM_COUNT;
}

switch(arg_count) {
    case 5:
        convert_to_double_ex(args[4]);
        conv = (unsigned long) (Z_DVAL_P(args[4]) * 1000000.0);
        timeout.tv_sec = conv / 1000000;
        timeout.tv_usec = conv % 1000000;
        /* fall-through */
    case 4:
        if (!PZVAL_IS_REF(*args[3])) {
            php_error(E_WARNING,"error string argument to fsockopen not passed by reference");
        }
        pval_copy_constructor(*args[3]);
        ZVAL_EMPTY_STRING(*args[3]);
        /* fall-through */
    case 3:
        if (!PZVAL_IS_REF(*args[2])) {
            php_error(E_WARNING,"error argument to fsockopen not passed by reference");
            return;
        }
        ZVAL_LONG(*args[2], 0);
        break;
}

convert_to_string_ex(args[0]);
convert_to_long_ex(args[1]);
portno = (unsigned short) Z_LVAL_P(args[1]);

key = emalloc(Z_STRLEN_P(args[0]) + 10);

fsockopen() accepts two, three, four, or five parameters. After the obligatory variable declarations, the function checks for the correct range of arguments. Then it uses a fall-through mechanism in a switch() statement to deal with all arguments. The switch() statement starts with the maximum number of arguments being passed (five). After that, it automatically processes the case of four arguments being passed, then three, by omitting the otherwise obligatory break keyword in all stages. After having processed the last case, it exits the switch() statement and does the minimal argument processing needed if the function is invoked with only two arguments.

This multiple-stage type of processing, similar to a stairway, allows convenient processing of a variable number of arguments.

Accessing Arguments

To access arguments, it's necessary for each argument to have a clearly defined type. Again, PHP's extremely dynamic nature introduces some quirks. Because PHP never does any kind of type checking, it's possible for a caller to pass any kind of data to your functions, whether you want it or not. If you expect an integer, for example, the caller might pass an array, and vice versa - PHP simply won't notice.

To work around this, you have to use a set of API functions to force a type conversion on every argument that's being passed (see Table 32-1).

Note: All conversion functions expect a **zval as parameter.

Table 32-1. Argument Conversion Functions

Function	Description
convert_to_boolean_ex()	Forces conversion to a Boolean type. Boolean values remain untouched. Longs, doubles, and strings containing `0` as well as NULL values will result in Boolean `0` (FALSE). Arrays and objects are converted based on the number of entries or properties, respectively, that they have. Empty arrays and objects are converted to FALSE; otherwise, to TRUE. All other values result in a Boolean `1` (TRUE).
convert_to_long_ex()	Forces conversion to a long, the default integer type. NULL values, Booleans, resources, and of course longs remain untouched. Doubles are truncated. Strings containing an integer are converted to their corresponding numeric representation, otherwise resulting in `0`. Arrays and objects are converted to `0` if empty, `1` otherwise.
convert_to_double_ex()	Forces conversion to a double, the default floating-point type. NULL values, Booleans, resources, longs, and of course doubles remain untouched. Strings containing a number are converted to their corresponding numeric representation, otherwise resulting in `0.0`. Arrays and objects are converted to `0.0` if empty, `1.0` otherwise.
convert_to_string_ex()	Forces conversion to a string. Strings remain untouched. NULL values are converted to an empty string. Booleans containing TRUE are converted to `"1"`, otherwise resulting in an empty string. Longs and doubles are converted to their corresponding string representation. Arrays are converted to the string `"Array"` and objects to the string `"Object"`.
`convert_to_array_ex(value)`	Forces conversion to an array. Arrays remain untouched. Objects are converted to an array by assigning all their properties to the array table. All property names are used as keys, property contents as values. NULL values are converted to an empty array. All other values are converted to an array that contains the specific source value in the element with the key `0`.
`convert_to_object_ex(value)`	Forces conversion to an object. Objects remain untouched. NULL values are converted to an empty object. Arrays are converted to objects by introducing their keys as properties into the objects and their values as corresponding property contents in the object. All other types result in an object with the property `scalar` , having the corresponding source value as content.
`convert_to_null_ex(value)`	Forces the type to become a NULL value, meaning empty.

Note: You can find a demonstration of the behavior in cross_conversion.php on the accompanying CD-ROM. Figure 32-2 shows the output.

Figure 32-2. Cross-conversion behavior of PHP.

Using these functions on your arguments will ensure type safety for all data that's passed to you. If the supplied type doesn't match the required type, PHP forces dummy contents on the resulting value (empty strings, arrays, or objects, 0 for numeric values, FALSE for Booleans) to ensure a defined state.

Following is a quote from the sample module discussed previously, which makes use of the conversion functions:
zval **parameter; if((ZEND_NUM_ARGS() != 1) || (zend_get_parameters_ex(1, &parameter) != SUCCESS)) { WRONG_PARAM_COUNT; } convert_to_long_ex(parameter); RETURN_LONG(Z_LVAL_P(parameter));
After retrieving the parameter pointer, the parameter value is converted to a long (an integer), which also forms the return value of this function. Understanding access to the contents of the value requires a short discussion of the zval type, whose definition is shown in Example 32-2.

Example 32-2. PHP/Zend zval type definition.

typedef pval zval;
     
typedef struct _zval_struct zval;

typedef union _zvalue_value {
	long lval;					/* long value */
	double dval;				/* double value */
	struct {
		char *val;
		int len;
	} str;
	HashTable *ht;				/* hash table value */
	struct {
		zend_class_entry *ce;
		HashTable *properties;
	} obj;
} zvalue_value;

struct _zval_struct {
	/* Variable information */
	zvalue_value value;		/* value */
	unsigned char type;	/* active type */
	unsigned char is_ref;
	short refcount;
};

Actually, pval (defined in php.h) is only an alias of zval (defined in zend.h), which in turn refers to _zval_struct. This is a most interesting structure. _zval_struct is the "master" structure, containing the value structure, type, and reference information. The substructure zvalue_value is a union that contains the variable's contents. Depending on the variable's type, you'll have to access different members of this union. For a description of both structures, see Table 32-2, Table 32-3 and Table 32-4.

Table 32-2. Zend zval Structure

Entry	Description
`value`	Union containing this variable's contents. See Table 32-3 for a description.
`type`	Contains this variable's type. For a list of available types, see Table 32-4.
`is_ref`	0 means that this variable is not a reference; 1 means that this variable is a reference to another variable.
`refcount`	The number of references that exist for this variable. For every new reference to the value stored in this variable, this counter is increased by 1. For every lost reference, this counter is decreased by 1. When the reference counter reaches 0, no references exist to this value anymore, which causes automatic freeing of the value.

Table 32-3. Zend zvalue_value Structure

Entry	Description
`lval`	Use this property if the variable is of the type `IS_LONG`, `IS_BOOLEAN`, or `IS_RESOURCE`.
`dval`	Use this property if the variable is of the type `IS_DOUBLE`.
`str`	This structure can be used to access variables of the type `IS_STRING`. The member `len` contains the string length; the member `val` points to the string itself. Zend uses C strings; thus, the string length contains a trailing `0x00`.
`ht`	This entry points to the variable's hash table entry if the variable is an array.
`obj`	Use this property if the variable is of the type `IS_OBJECT`.

Table 32-4. Zend Variable Type Constants

Constant	Description
`IS_NULL`	Denotes a NULL (empty) value.
`IS_LONG`	A long (integer) value.
`IS_DOUBLE`	A double (floating point) value.
`IS_STRING`	A string.
`IS_ARRAY`	Denotes an array.
`IS_OBJECT`	An object.
`IS_BOOL`	A Boolean value.
`IS_RESOURCE`	A resource (for a discussion of resources, see the appropriate section below).
`IS_CONSTANT`	A constant (defined) value.

To access a long you access zval.value.lval, to access a double you use zval.value.dval, and so on. Because all values are stored in a union, trying to access data with incorrect union members results in meaningless output.

Accessing arrays and objects is a bit more complicated and is discussed later.

Dealing with Arguments Passed by Reference

If your function accepts arguments passed by reference that you intend to modify, you need to take some precautions.

What we didn't say yet is that under the circumstances presented so far, you don't have write access to any zval containers designating function parameters that have been passed to you. Of course, you can change any zval containers that you created within your function, but you mustn't change any zvals that refer to Zend-internal data!

We've only discussed the so-called *_ex() API so far. You may have noticed that the API functions we've used are called zend_get_parameters_ex() instead of zend_get_parameters(), convert_to_long_ex() instead of convert_to_long(), etc. The *_ex() functions form the so-called new "extended" Zend API. They give a minor speed increase over the old API, but as a tradeoff are only meant for providing read-only access.

Because Zend works internally with references, different variables may reference the same value. Write access to a zval container requires this container to contain an isolated value, meaning a value that's not referenced by any other containers. If a zval container were referenced by other containers and you changed the referenced zval, you would automatically change the contents of the other containers referencing this zval (because they'd simply point to the changed value and thus change their own value as well).

zend_get_parameters_ex() doesn't care about this situation, but simply returns a pointer to the desired zval containers, whether they consist of references or not. Its corresponding function in the traditional API, zend_get_parameters(), immediately checks for referenced values. If it finds a reference, it creates a new, isolated zval container; copies the referenced data into this newly allocated space; and then returns a pointer to the new, isolated value.

This action is called zval separation (or pval separation). Because the *_ex() API doesn't perform zval separation, it's considerably faster, while at the same time disabling write access.

To change parameters, however, write access is required. Zend deals with this situation in a special way: Whenever a parameter to a function is passed by reference, it performs automatic zval separation. This means that whenever you're calling a function like this in PHP, Zend will automatically ensure that $parameter is being passed as an isolated value, rendering it to a write-safe state:
my_function(&$parameter);

But this is not the case with regular parameters! All other parameters that are not passed by reference are in a read-only state.

This requires you to make sure that you're really working with a reference - otherwise you might produce unwanted results. To check for a parameter being passed by reference, you can use the macro PZVAL_IS_REF. This macro accepts a zval* to check if it is a reference or not. Examples are given in in Example 32-3.

Example 32-3. Testing for referenced parameter passing.

zval *parameter;

if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "z", &parameter) == FAILURE)
    return;

/* check for parameter being passed by reference */
if (!PZVAL_IS_REF(*parameter)) {
{
    zend_error(E_WARNING, "Parameter wasn't passed by reference");
    RETURN_NULL();
}

/* make changes to the parameter */
ZVAL_LONG(*parameter, 10);

Assuring Write Safety for Other Parameters

You might run into a situation in which you need write access to a parameter that's retrieved with zend_get_parameters_ex() but not passed by reference. For this case, you can use the macro SEPARATE_ZVAL, which does a zval separation on the provided container. The newly generated zval is detached from internal data and has only a local scope, meaning that it can be changed or destroyed without implying global changes in the script context:
zval **parameter; /* retrieve parameter */ zend_get_parameters_ex(1, &parameter); /* at this stage, <parameter> still is connected */ /* to Zend's internal data buffers */ /* make <parameter> write-safe */ SEPARATE_ZVAL(parameter); /* now we can safely modify <parameter> */ /* without implying global changes */
SEPARATE_ZVAL uses emalloc() to allocate the new zval container, which means that even if you don't deallocate this memory yourself, it will be destroyed automatically upon script termination. However, doing a lot of calls to this macro without freeing the resulting containers will clutter up your RAM.

Note: As you can easily work around the lack of write access in the "traditional" API (with zend_get_parameters() and so on), this API seems to be obsolete, and is not discussed further in this chapter.

Chapter 33. Creating Variables

When exchanging data from your own extensions with PHP scripts, one of the most important issues is the creation of variables. This section shows you how to deal with the variable types that PHP supports.

Overview

To create new variables that can be seen "from the outside" by the executing script, you need to allocate a new zval container, fill this container with meaningful values, and then introduce it to Zend's internal symbol table. This basic process is common to all variable creations:

zval *new_variable; 

/* allocate and initialize new container */
MAKE_STD_ZVAL(new_variable); 

/* set type and variable contents here, see the following sections */ 

/* introduce this variable by the name "new_variable_name" into the symbol table */
ZEND_SET_SYMBOL(EG(active_symbol_table), "new_variable_name", new_variable); 

/* the variable is now accessible to the script by using $new_variable_name */

The macro MAKE_STD_ZVAL allocates a new zval container using ALLOC_ZVAL and initializes it using INIT_ZVAL. As implemented in Zend at the time of this writing, initializing means setting the reference count to 1 and clearing the is_ref flag, but this process could be extended later - this is why it's a good idea to keep using MAKE_STD_ZVAL instead of only using ALLOC_ZVAL. If you want to optimize for speed (and you don't have to explicitly initialize the zval container here), you can use ALLOC_ZVAL, but this isn't recommended because it doesn't ensure data integrity.

ZEND_SET_SYMBOL takes care of introducing the new variable to Zend's symbol table. This macro checks whether the value already exists in the symbol table and converts the new symbol to a reference if so (with automatic deallocation of the old zval container). This is the preferred method if speed is not a crucial issue and you'd like to keep memory usage low.

Note that ZEND_SET_SYMBOL makes use of the Zend executor globals via the macro EG. By specifying EG(active_symbol_table), you get access to the currently active symbol table, dealing with the active, local scope. The local scope may differ depending on whether the function was invoked from within a function.

If you need to optimize for speed and don't care about optimal memory usage, you can omit the check for an existing variable with the same value and instead force insertion into the symbol table by using zend_hash_update():
zval *new_variable; /* allocate and initialize new container */ MAKE_STD_ZVAL(new_variable); /* set type and variable contents here, see the following sections */ /* introduce this variable by the name "new_variable_name" into the symbol table */ zend_hash_update( EG(active_symbol_table), "new_variable_name", strlen("new_variable_name") + 1, &new_variable, sizeof(zval *), NULL );
This is actually the standard method used in most modules.

The variables generated with the snippet above will always be of local scope, so they reside in the context in which the function has been called. To create new variables in the global scope, use the same method but refer to another symbol table:
zval *new_variable; // allocate and initialize new container MAKE_STD_ZVAL(new_variable); // // set type and variable contents here // // introduce this variable by the name "new_variable_name" into the global symbol table ZEND_SET_SYMBOL(&EG(symbol_table), "new_variable_name", new_variable);
The macro ZEND_SET_SYMBOL is now being called with a reference to the main, global symbol table by referring EG(symbol_table).

Note: The active_symbol_table variable is a pointer, but symbol_table is not. This is why you have to use EG(active_symbol_table) and &EG(symbol_table) as parameters to ZEND_SET_SYMBOL - it requires a pointer.

Similarly, to get a more efficient version, you can hardcode the symbol table update:
zval *new_variable; // allocate and initialize new container MAKE_STD_ZVAL(new_variable); // // set type and variable contents here // // introduce this variable by the name "new_variable_name" into the global symbol table zend_hash_update( &EG(symbol_table), "new_variable_name", strlen("new_variable_name") + 1, &new_variable, sizeof(zval *), NULL );
Example 33-1 shows a sample source that creates two variables - local_variable with a local scope and global_variable with a global scope (see Figure 9.7). The full example can be found on the CD-ROM.

Note: You can see that the global variable is actually not accessible from within the function. This is because it's not imported into the local scope using global $global_variable; in the PHP source.

Example 33-1. Creating variables with different scopes.

ZEND_FUNCTION(variable_creation)
{
    zval *new_var1, *new_var2;

    MAKE_STD_ZVAL(new_var1);
    MAKE_STD_ZVAL(new_var2);

    ZVAL_LONG(new_var1, 10);
    ZVAL_LONG(new_var2, 5);

    ZEND_SET_SYMBOL(EG(active_symbol_table), "local_variable", new_var1);
    ZEND_SET_SYMBOL(&EG(symbol_table), "global_variable", new_var2);

    RETURN_NULL();

}

Longs (Integers)

Now let's get to the assignment of data to variables, starting with longs. Longs are PHP's integers and are very simple to store. Looking at the zval.value container structure discussed earlier in this chapter, you can see that the long data type is directly contained in the union, namely in the lval field. The corresponding type value for longs is IS_LONG (see Example 33-2).
Example 33-2. Creation of a long.
zval *new_long; MAKE_STD_ZVAL(new_long); new_long->type = IS_LONG; new_long->value.lval = 10;
Alternatively, you can use the macro ZVAL_LONG:
zval *new_long; MAKE_STD_ZVAL(new_long); ZVAL_LONG(new_long, 10);

Doubles (Floats)

Doubles are PHP's floats and are as easy to assign as longs, because their value is also contained directly in the union. The member in the zval.value container is dval; the corresponding type is IS_DOUBLE.
zval *new_double; MAKE_STD_ZVAL(new_double); new_double->type = IS_DOUBLE; new_double->value.dval = 3.45;
Alternatively, you can use the macro ZVAL_DOUBLE:
zval *new_double; MAKE_STD_ZVAL(new_double); ZVAL_DOUBLE(new_double, 3.45);

Strings

Strings need slightly more effort. As mentioned earlier, all strings that will be associated with Zend's internal data structures need to be allocated using Zend's own memory-management functions. Referencing of static strings or strings allocated with standard routines is not allowed. To assign strings, you have to access the structure str in the zval.value container. The corresponding type is IS_STRING:
zval *new_string; char *string_contents = "This is a new string variable"; MAKE_STD_ZVAL(new_string); new_string->type = IS_STRING; new_string->value.str.len = strlen(string_contents); new_string->value.str.val = estrdup(string_contents);
Note the usage of Zend's estrdup() here. Of course, you can also use the predefined macro ZVAL_STRING:
zval *new_string; char *string_contents = "This is a new string variable"; MAKE_STD_ZVAL(new_string); ZVAL_STRING(new_string, string_contents, 1);
ZVAL_STRING accepts a third parameter that indicates whether the supplied string contents should be duplicated (using estrdup()). Setting this parameter to 1 causes the string to be duplicated; 0 simply uses the supplied pointer for the variable contents. This is most useful if you want to create a new variable referring to a string that's already allocated in Zend internal memory.

If you want to truncate the string at a certain position or you already know its length, you can use ZVAL_STRINGL(zval, string, length, duplicate), which accepts an explicit string length to be set for the new string. This macro is faster than ZVAL_STRING and also binary-safe.

To create empty strings, set the string length to 0 and use empty_string as contents:
new_string->type = IS_STRING; new_string->value.str.len = 0; new_string->value.str.val = empty_string;
Of course, there's a macro for this as well (ZVAL_EMPTY_STRING):
MAKE_STD_ZVAL(new_string); ZVAL_EMPTY_STRING(new_string);

Booleans

Booleans are created just like longs, but have the type IS_BOOL. Allowed values in lval are 0 and 1:
zval *new_bool; MAKE_STD_ZVAL(new_bool); new_bool->type = IS_BOOL; new_bool->value.lval = 1;
The corresponding macros for this type are ZVAL_BOOL (allowing specification of the value) as well as ZVAL_TRUE and ZVAL_FALSE (which explicitly set the value to TRUE and FALSE, respectively).

Arrays

Arrays are stored using Zend's internal hash tables, which can be accessed using the zend_hash_*() API. For every array that you want to create, you need a new hash table handle, which will be stored in the ht member of the zval.value container.

There's a whole API solely for the creation of arrays, which is extremely handy. To start a new array, you call array_init().
zval *new_array; MAKE_STD_ZVAL(new_array); if(array_init(new_array) != SUCCESS) { // do error handling here }
If array_init() fails to create a new array, it returns FAILURE.

To add new elements to the array, you can use numerous functions, depending on what you want to do. Table 33-1, Table 33-2 and Table 33-3 describe these functions. All functions return FAILURE on failure and SUCCESS on success.

Table 33-1. Zend's API for Associative Arrays

Function	Description
*add_assoc_long(zval array, char key, long n);()*	Adds an element of type `long`.
*add_assoc_unset(zval array, char key);()*	Adds an unset element.
*add_assoc_bool(zval array, char key, int b);()*	Adds a Boolean element.
*add_assoc_resource(zval array, char key, int r);()*	Adds a resource to the array.
*add_assoc_double(zval array, char key, double d);()*	Adds a floating-point value.
*add_assoc_string(zval array, char key, char str, int duplicate);()**	Adds a string to the array. The flag `duplicate` specifies whether the string contents have to be copied to Zend internal memory.
*add_assoc_stringl(zval array, char key, char str, uint length, int duplicate); ()**	Adds a string with the desired length `length` to the array. Otherwise, behaves like add_assoc_string().

Table 33-2. Zend's API for Indexed Arrays, Part 1

Function	Description
*add_index_long(zval array, uint idx, long n);()**	Adds an element of type `long`.
*add_index_unset(zval array, uint idx);()**	Adds an unset element.
*add_index_bool(zval array, uint idx, int b);()**	Adds a Boolean element.
*add_index_resource(zval array, uint idx, int r);()**	Adds a resource to the array.
*add_index_double(zval array, uint idx, double d);()**	Adds a floating-point value.
*add_index_string(zval array, uint idx, char str, int duplicate);()*	Adds a string to the array. The flag `duplicate` specifies whether the string contents have to be copied to Zend internal memory.
*add_index_stringl(zval array, uint idx, char str, uint length, int duplicate);()*	Adds a string with the desired length `length` to the array. This function is faster and binary-safe. Otherwise, behaves like add_index_string()().

Table 33-3. Zend's API for Indexed Arrays, Part 2

Function	Description
*add_next_index_long(zval array, long n);()**	Adds an element of type `long`.
*add_next_index_unset(zval array);()**	Adds an unset element.
*add_next_index_bool(zval array, int b);()**	Adds a Boolean element.
*add_next_index_resource(zval array, int r);()**	Adds a resource to the array.
*add_next_index_double(zval array, double d);()**	Adds a floating-point value.
*add_next_index_string(zval array, char str, int duplicate);()*	Adds a string to the array. The flag `duplicate` specifies whether the string contents have to be copied to Zend internal memory.
*add_next_index_stringl(zval array, char str, uint length, int duplicate);()*	Adds a string with the desired length `length` to the array. This function is faster and binary-safe. Otherwise, behaves like add_index_string()().

All these functions provide a handy abstraction to Zend's internal hash API. Of course, you can also use the hash functions directly - for example, if you already have a zval container allocated that you want to insert into an array. This is done using zend_hash_update()() for associative arrays (see Example 33-3) and zend_hash_index_update() for indexed arrays (see Example 33-4):
Example 33-3. Adding an element to an associative array.
zval *new_array, *new_element; char *key = "element_key"; MAKE_STD_ZVAL(new_array); MAKE_STD_ZVAL(new_element); if(array_init(new_array) == FAILURE) { // do error handling here } ZVAL_LONG(new_element, 10); if(zend_hash_update(new_array->value.ht, key, strlen(key) + 1, (void *)&new_element, sizeof(zval *), NULL) == FAILURE) { // do error handling here }

Example 33-4. Adding an element to an indexed array.
zval *new_array, *new_element; int key = 2; MAKE_STD_ZVAL(new_array); MAKE_STD_ZVAL(new_element); if(array_init(new_array) == FAILURE) { // do error handling here } ZVAL_LONG(new_element, 10); if(zend_hash_index_update(new_array->value.ht, key, (void *)&new_element, sizeof(zval *), NULL) == FAILURE) { // do error handling here }

To emulate the functionality of add_next_index_*(), you can use this:

zend_hash_next_index_insert(ht, zval **new_element, sizeof(zval *), NULL)

Note: To return arrays from a function, use array_init() and all following actions on the predefined variable return_value (given as argument to your exported function; see the earlier discussion of the call interface). You do not have to use MAKE_STD_ZVAL on this.

Tip: To avoid having to write new_array->value.ht every time, you can use HASH_OF(new_array), which is also recommended for compatibility and style reasons.

Objects

Since objects can be converted to arrays (and vice versa), you might have already guessed that they have a lot of similarities to arrays in PHP. Objects are maintained with the same hash functions, but there's a different API for creating them.

To initialize an object, you use the function object_init():
zval *new_object; MAKE_STD_ZVAL(new_object); if(object_init(new_object) != SUCCESS) { // do error handling here }
You can use the functions described in Table 33-4 to add members to your object.

Table 33-4. Zend's API for Object Creation

Function	Description
*add_property_long(zval object, char key, long l);()*	Adds a long to the object.
*add_property_unset(zval object, char key);()*	Adds an unset property to the object.
*add_property_bool(zval object, char key, int b);()*	Adds a Boolean to the object.
*add_property_resource(zval object, char key, long r);()*	Adds a resource to the object.
*add_property_double(zval object, char key, double d);()*	Adds a double to the object.
*add_property_string(zval object, char key, char str, int duplicate);()**	Adds a string to the object.
*add_property_stringl(zval object, char key, char str, uint length, int duplicate);()**	Adds a string of the specified length to the object. This function is faster than add_property_string() and also binary-safe.
*add_property_zval(zval obect, char key, zval container):()**	Adds a `zval` container to the object. This is useful if you have to add properties which aren't simple types like integers or strings but arrays or other objects.

Resources

Resources are a special kind of data type in PHP. The term resources doesn't really refer to any special kind of data, but to an abstraction method for maintaining any kind of information. Resources are kept in a special resource list within Zend. Each entry in the list has a correspondending type definition that denotes the kind of resource to which it refers. Zend then internally manages all references to this resource. Access to a resource is never possible directly - only via a provided API. As soon as all references to a specific resource are lost, a corresponding shutdown function is called.

For example, resources are used to store database links and file descriptors. The de facto standard implementation can be found in the MySQL module, but other modules such as the Oracle module also make use of resources.

Note: In fact, a resource can be a pointer to anything you need to handle in your functions (e.g. pointer to a structure) and the user only has to pass a single resource variable to your function.

To create a new resource you need to register a resource destruction handler for it. Since you can store any kind of data as a resource, Zend needs to know how to free this resource if its not longer needed. This works by registering your own resource destruction handler to Zend which in turn gets called by Zend whenever your resource can be freed (whether manually or automatically). Registering your resource handler within Zend returns you the resource type handle for that resource. This handle is needed whenever you want to access a resource of this type later and is most of time stored in a global static variable within your extension. There is no need to worry about thread safety here because you only register your resource handler once during module initialization.

The Zend function to register your resource handler is defined as:
ZEND_API int zend_register_list_destructors_ex(rsrc_dtor_func_t ld, rsrc_dtor_func_t pld, char *type_name, int module_number);

There are two different kinds of resource destruction handlers you can pass to this function: a handler for normal resources and a handler for persistent resources. Persistent resources are for example used for database connection. When registering a resource, either of these handlers must be given. For the other handler just pass NULL.

zend_register_list_destructors_ex() accepts the following parameters:

`ld`	Normal resource destruction handler callback
`pld`	Pesistent resource destruction handler callback
`type_name`	A string specifying the name of your resource. It's always a good thing to specify an unique name within PHP for the resource type so when the user for example calls `var_dump($resource);` he also gets the name of the resource.
`module_number`	The `module_number` is automatically available in your `PHP_MINIT_FUNCTION` function and therefore you just pass it over.

The return value is an unique integer ID for your resource type.

The resource destruction handler (either normal or persistent resources) has the following prototype:
void resource_destruction_handler(zend_rsrc_list_entry *rsrc TSRMLS_DC);
The passed rsrc is a pointer to the following structure:
typedef struct _zend_rsrc_list_entry { void *ptr; int type; int refcount; } zend_rsrc_list_entry;
The member void *ptr is the actual pointer to your resource.

Now we know how to start things, we define our own resource we want register within Zend. It is only a simple structure with two integer members:
typedef struct { int resource_link; int resource_type; } my_resource;
Our resource destruction handler is probably going to look something like this:
void my_destruction_handler(zend_rsrc_list_entry *rsrc TSRMLS_DC) { // You most likely cast the void pointer to your structure type my_resource *my_rsrc = (my_resource *) rsrc->ptr; // Now do whatever needs to be done with you resource. Closing // Files, Sockets, freeing additional memory, etc. // Also, don't forget to actually free the memory for your resource too! do_whatever_needs_to_be_done_with_the_resource(my_rsrc); }

Note: One important thing to mention: If your resource is a rather complex structure which also contains pointers to memory you allocated during runtime you have to free them before freeing the resource itself!

Now that we have defined

what our resource is and
our resource destruction handler

we can go on and do the rest of the steps:

create a global variable within the extension holding the resource ID so it can be accessed from every function which needs it
define the resource name
write the resource destruction handler
and finally register the handler

// Somewhere in your extension, define the variable for your registered resources.
    // If you wondered what 'le' stands for: it simply means 'list entry'.
    static int le_myresource;

    // It's nice to define your resource name somewhere
    #define le_myresource_name  "My type of resource"

    [...]

    // Now actually define our resource destruction handler
    void my_destruction_handler(zend_rsrc_list_entry *rsrc TSRMLS_DC) {

        my_resource *my_rsrc = (my_resource *) rsrc->ptr;
        do_whatever_needs_to_be_done_with_the_resource(my_rsrc);
    }

    [...]

    PHP_MINIT_FUNCTION(my_extension) {

        // Note that 'module_number' is already provided through the
        // PHP_MINIT_FUNCTION() function definition.

        le_myresource = zend_register_resource_destructors_ex(my_destruction_handler, NULL, le_myresource_name, module_number);

        // You can register additional resources, initialize
        // your global vars, constants, whatever.
    }

To actually register a new resource you use can either use the zend_register_resource() function or the ZEND_REGISTER_RESOURE() macro, both defined in zend_list.h . Although the arguments for both map 1:1 it's a good idea to always use macros to be upwards compatible:
int ZEND_REGISTER_RESOURCE(zval *rsrc_result, void *rsrc_pointer, int rsrc_type);

`rsrc_result`	This is an already initialized `zval *` container.
`rsrc_pointer`	Your resource pointer you want to store.
`rsrc_type`	The type which you received when you registered the resource destruction handler. If you followed the naming scheme this would be `le_myresource`.

The return value is an unique integer identifier for that resource.

What is really going on when you register a new resource is it gets inserted in an internal list in Zend and the result is just stored in the given zval * container:
rsrc_id = zend_list_insert(rsrc_pointer, rsrc_type); if (rsrc_result) { rsrc_result->value.lval = rsrc_id; rsrc_result->type = IS_RESOURCE; } return rsrc_id;
The returned rsrc_id uniquly identifies the newly registered resource. You can use the macro RETURN_RESOURE to return it to the user:
RETURN_RESOURCE(rsrc_id)

Note: It is common practice that if you want to return the resource immidiately to the user you specify the return_value as the zval * container.

Zend now keeps track of all references to this resource. As soon as all references to the resource are lost, the destructor that you previously registered for this resource is called. The nice thing about this setup is that you don't have to worry about memory leakages introduced by allocations in your module - just register all memory allocations that your calling script will refer to as resources. As soon as the script decides it doesn't need them anymore, Zend will find out and tell you.

Now that the user got his resource, at some point he is passing it back to one of your functions. The value.lval inside the zval * container contains the key to your resource and thus can be used to fetch the resource with the following macro: ZEND_FETCH_RESOURCE:
ZEND_FETCH_RESOURCE(rsrc, rsrc_type, rsrc_id, default_rsrc_id, resource_type_name, resource_type)

`rsrc`	This is your pointer which will point to your previously registered resource.
`rsrc_type`	This is the typecast argument for your pointer, e.g. `myresource *`.
`rsrc_id`	This is the address of the `zval `container the user passed to your function, e.g. `&z_resource` if `zval z_resource` is given.
`default_rsrc_id`	This integer specifies the default resource `ID` if no resource could be fetched or -1.
`resource_type_name`	This is the name of the requested resource. It's a string and is used when the resource can't be found or is invalid to form a meaningful error message.
`resource_type`	The `resource_type` you got back when registering the resource destruction handler. In our example this was `le_myresource`.

This macro has no return value. It is for the developers convenience and takes care of TSRMLS arguments passing and also does check if the resource could be fetched. It throws a warning message and returns the current PHP function with NULL if there was a problem retrieving the resource.

To force removal of a resource from the list, use the function zend_list_delete(). You can also force the reference count to increase if you know that you're creating another reference for a previously allocated value (for example, if you're automatically reusing a default database link). For this case, use the function zend_list_addref(). To search for previously allocated resource entries, use zend_list_find(). The complete API can be found in zend_list.h.

Macros for Automatic Global Variable Creation

In addition to the macros discussed earlier, a few macros allow easy creation of simple global variables. These are nice to know in case you want to introduce global flags, for example. This is somewhat bad practice, but Table Table 33-5 describes macros that do exactly this task. They don't need any zval allocation; you simply have to supply a variable name and value.

Table 33-5. Macros for Global Variable Creation

Macro	Description
`SET_VAR_STRING(name, value)`	Creates a new string.
`SET_VAR_STRINGL(name, value, length)`	Creates a new string of the specified length. This macro is faster than `SET_VAR_STRING` and also binary-safe.
`SET_VAR_LONG(name, value)`	Creates a new long.
`SET_VAR_DOUBLE(name, value)`	Creates a new double.

Creating Constants

Zend supports the creation of true constants (as opposed to regular variables). Constants are accessed without the typical dollar sign ($) prefix and are available in all scopes. Examples include TRUE and FALSE, to name just two.

To create your own constants, you can use the macros in Table 33-6. All the macros create a constant with the specified name and value.

You can also specify flags for each constant:

CONST_CS - This constant's name is to be treated as case sensitive.
CONST_PERSISTENT - This constant is persistent and won't be "forgotten" when the current process carrying this constant shuts down.

To use the flags, combine them using a inary OR:

// register a new constant of type "long"
     REGISTER_LONG_CONSTANT("NEW_MEANINGFUL_CONSTANT", 324, CONST_CS |
     CONST_PERSISTENT);

There are two types of macros - REGISTER_*_CONSTANT andREGISTER_MAIN_*_CONSTANT. The first type creates constants bound to the current module. These constants are dumped from the symbol table as soon as the module that registered the constant is unloaded from memory. The second type creates constants that remain in the symbol table independently of the module.

Table 33-6. Macros for Creating Constants

Macro	Description
`REGISTER_LONG_CONSTANT(name, value, flags)` `REGISTER_MAIN_LONG_CONSTANT(name, value, flags)`	Registers a new constant of type long.
`REGISTER_DOUBLE_CONSTANT(name, value, flags)` `REGISTER_MAIN_DOUBLE_CONSTANT(name, value, flags)`	Registers a new constant of type double.
`REGISTER_STRING_CONSTANT(name, value, flags)` `REGISTER_MAIN_STRING_CONSTANT(name, value, flags)`	Registers a new constant of type string. The specified string must reside in Zend's internal memory.
`REGISTER_STRINGL_CONSTANT(name, value, length, flags)` `REGISTER_MAIN_STRINGL_CONSTANT(name, value, length, flags)`	Registers a new constant of type string. The string length is explicitly set to `length`. The specified string must reside in Zend's internal memory.

Chapter 34. Duplicating Variable Contents: The Copy Constructor

Sooner or later, you may need to assign the contents of one zval container to another. This is easier said than done, since the zval container doesn't contain only type information, but also references to places in Zend's internal data. For example, depending on their size, arrays and objects may be nested with lots of hash table entries. By assigning one zval to another, you avoid duplicating the hash table entries, using only a reference to them (at most).

To copy this complex kind of data, use the copy constructor. Copy constructors are typically defined in languages that support operator overloading, with the express purpose of copying complex types. If you define an object in such a language, you have the possibility of overloading the "=" operator, which is usually responsible for assigning the contents of the lvalue (result of the evaluation of the left side of the operator) to the rvalue (same for the right side).

Overloading means assigning a different meaning to this operator, and is usually used to assign a function call to an operator. Whenever this operator would be used on such an object in a program, this function would be called with the lvalue and rvalue as parameters. Equipped with that information, it can perform the operation it intends the "=" operator to have (usually an extended form of copying).

This same form of "extended copying" is also necessary for PHP's zval containers. Again, in the case of an array, this extended copying would imply re-creation of all hash table entries relating to this array. For strings, proper memory allocation would have to be assured, and so on.

Zend ships with such a function, called zend_copy_ctor() (the previous PHP equivalent was pval_copy_constructor()).

A most useful demonstration is a function that accepts a complex type as argument, modifies it, and then returns the argument:

zval *parameter;
   
if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "z", &parameter) == FAILURE)
   return;
}
   
// do modifications to the parameter here

// now we want to return the modified container:
*return_value == *parameter;
zval_copy_ctor(return_value);

The first part of the function is plain-vanilla argument retrieval. After the (left out) modifications, however, it gets interesting: The container of parameter is assigned to the (predefined) return_value container. Now, in order to effectively duplicate its contents, the copy constructor is called. The copy constructor works directly with the supplied argument, and the standard return values are FAILURE on failure and SUCCESS on success.

If you omit the call to the copy constructor in this example, both parameter and return_value would point to the same internal data, meaning that return_value would be an illegal additional reference to the same data structures. Whenever changes occurred in the data that parameter points to, return_value might be affected. Thus, in order to create separate copies, the copy constructor must be used.

The copy constructor's counterpart in the Zend API, the destructor zval_dtor(), does the opposite of the constructor.

Chapter 35. Returning Values

Returning values from your functions to PHP was described briefly in an earlier section; this section gives the details. Return values are passed via the return_value variable, which is passed to your functions as argument. The return_value argument consists of a zval container (see the earlier discussion of the call interface) that you can freely modify. The container itself is already allocated, so you don't have to run MAKE_STD_ZVAL on it. Instead, you can access its members directly.

To make returning values from functions easier and to prevent hassles with accessing the internal structures of the zval container, a set of predefined macros is available (as usual). These macros automatically set the correspondent type and value, as described in Table 35-1 and Table 35-2.

Note: The macros in Table 35-1 automatically return from your function, those in Table 35-2 only set the return value; they don't return from your function.

Table 35-1. Predefined Macros for Returning Values from a Function

Macro	Description
`RETURN_RESOURCE(resource)`	Returns a resource.
`RETURN_BOOL(bool)`	Returns a Boolean.
`RETURN_NULL()`	Returns nothing (a NULL value).
`RETURN_LONG(long)`	Returns a long.
`RETURN_DOUBLE(double)`	Returns a double.
`RETURN_STRING(string, duplicate)`	Returns a string. The `duplicate` flag indicates whether the string should be duplicated using estrdup().
`RETURN_STRINGL(string, length, duplicate)`	Returns a string of the specified length; otherwise, behaves like `RETURN_STRING`. This macro is faster and binary-safe, however.
`RETURN_EMPTY_STRING()`	Returns an empty string.
`RETURN_FALSE`	Returns Boolean false.
`RETURN_TRUE`	Returns Boolean true.

Table 35-2. Predefined Macros for Setting the Return Value of a Function

Macro	Description
`RETVAL_RESOURCE(resource)`	Sets the return value to the specified resource.
`RETVAL_BOOL(bool)`	Sets the return value to the specified Boolean value.
`RETVAL_NULL`	Sets the return value to NULL.
`RETVAL_LONG(long)`	Sets the return value to the specified long.
`RETVAL_DOUBLE(double)`	Sets the return value to the specified double.
`RETVAL_STRING(string, duplicate)`	Sets the return value to the specified string and duplicates it to Zend internal memory if desired (see also `RETURN_STRING`).
`RETVAL_STRINGL(string, length, duplicate)`	Sets the return value to the specified string and forces the length to become `length` (see also `RETVAL_STRING`). This macro is faster and binary-safe, and should be used whenever the string length is known.
`RETVAL_EMPTY_STRING`	Sets the return value to an empty string.
`RETVAL_FALSE`	Sets the return value to Boolean false.
`RETVAL_TRUE`	Sets the return value to Boolean true.

Complex types such as arrays and objects can be returned by using array_init() and object_init(), as well as the corresponding hash functions on return_value. Since these types cannot be constructed of trivial information, there are no predefined macros for them.

Chapter 36. Printing Information

Often it's necessary to print messages to the output stream from your module, just as print() would be used within a script. PHP offers functions for most generic tasks, such as printing warning messages, generating output for phpinfo(), and so on. The following sections provide more details. Examples of these functions can be found on the CD-ROM.

zend_printf()

zend_printf() works like the standard printf(), except that it prints to Zend's output stream.

zend_error()

zend_error() can be used to generate error messages. This function accepts two arguments; the first is the error type (see zend_errors.h), and the second is the error message.
zend_error(E_WARNING, "This function has been called with empty arguments");
Table 36-1 shows a list of possible values (see Figure 36-1). These values are also referred to in php.ini. Depending on which error type you choose, your messages will be logged.

Table 36-1. Zend's Predefined Error Messages.

Error	Description
`E_ERROR`	Signals an error and terminates execution of the script immediately .
`E_WARNING`	Signals a generic warning. Execution continues.
`E_PARSE`	Signals a parser error. Execution continues.
`E_NOTICE`	Signals a notice. Execution continues. Note that by default the display of this type of error messages is turned off in `php.ini`.
`E_CORE_ERROR`	Internal error by the core; shouldn't be used by user-written modules.
`E_COMPILE_ERROR`	Internal error by the compiler; shouldn't be used by user-written modules.
`E_COMPILE_WARNING`	Internal warning by the compiler; shouldn't be used by user-written modules.

Figure 36-1. Display of warning messages in the browser.

Including Output in phpinfo()

After creating a real module, you'll want to show information about the module in phpinfo() (in addition to the module name, which appears in the module list by default). PHP allows you to create your own section in the phpinfo() output with the ZEND_MINFO() function. This function should be placed in the module descriptor block (discussed earlier) and is always called whenever a script calls phpinfo().

PHP automatically prints a section in phpinfo() for you if you specify the ZEND_MINFO function, including the module name in the heading. Everything else must be formatted and printed by you.

Typically, you can print an HTML table header using php_info_print_table_start() and then use the standard functions php_info_print_table_header() and php_info_print_table_row(). As arguments, both take the number of columns (as integers) and the column contents (as strings). Example 36-1 shows a source example and its output. To print the table footer, use php_info_print_table_end().

Example 36-1. Source code and screenshot for output in phpinfo().

php_info_print_table_start();
php_info_print_table_header(2, "First column", "Second column");
php_info_print_table_row(2, "Entry in first row", "Another entry");
php_info_print_table_row(2, "Just to fill", "another row here");
php_info_print_table_end();

Execution Information

You can also print execution information, such as the current file being executed. The name of the function currently being executed can be retrieved using the function get_active_function_name(). This function returns a pointer to the function name and doesn't accept any arguments. To retrieve the name of the file currently being executed, use zend_get_executed_filename(). This function accesses the executor globals, which are passed to it using the TSRMLS_C macro. The executor globals are automatically available to every function that's called directly by Zend (they're part of the INTERNAL_FUNCTION_PARAMETERS described earlier in this chapter). If you want to access the executor globals in another function that doesn't have them available automatically, call the macro TSRMLS_FETCH() once in that function; this will introduce them to your local scope.

Finally, the line number currently being executed can be retrieved using the function zend_get_executed_lineno(). This function also requires the executor globals as arguments. For examples of these functions, see Example 36-2.

Example 36-2. Printing execution information.

zend_printf("The name of the current function is %s<br>", get_active_function_name(TSRMLS_C));
zend_printf("The file currently executed is %s<br>", zend_get_executed_filename(TSRMLS_C));
zend_printf("The current line being executed is %i<br>", zend_get_executed_lineno(TSRMLS_C));

Chapter 37. Startup and Shutdown Functions

Startup and shutdown functions can be used for one-time initialization and deinitialization of your modules. As discussed earlier in this chapter (see the description of the Zend module descriptor block), there are global, module, and request startup and shutdown events.

The global startup functions are called once when PHP starts up; similarly, the global shutdown functions are called once when PHP shuts down. Please note that they're really only called once, not when a new Apache process is being created!

The module startup and shutdown functions are called whenever a module is loaded and needs initialization; the request startup and shutdown functions are called every time a request is processed (meaning that a file is being executed).

For dynamic extensions, module and request startup/shutdown events happen at the same time.

Declaration and implementation of these functions can be done with macros; see the earlier section "Declaration of the Zend Module Block" for details.

Chapter 38. Calling User Functions

You can call user functions from your own modules, which is very handy when implementing callbacks; for example, for array walking, searching, or simply for event-based programs.

User functions can be called with the function call_user_function_ex(). It requires a hash value for the function table you want to access, a pointer to an object (if you want to call a method), the function name, return value, number of arguments, argument array, and a flag indicating whether you want to perform zval separation.

ZEND_API int call_user_function_ex(HashTable *function_table, zval *object,
zval *function_name, zval **retval_ptr_ptr,
int param_count, zval **params[],
int no_separation);

Note that you don't have to specify both function_table and object; either will do. If you want to call a method, you have to supply the object that contains this method, in which case call_user_function()automatically sets the function table to this object's function table. Otherwise, you only need to specify function_table and can set object to NULL.

Usually, the default function table is the "root" function table containing all function entries. This function table is part of the compiler globals and can be accessed using the macro CG. To introduce the compiler globals to your function, call the macro TSRMLS_FETCH once.

The function name is specified in a zval container. This might be a bit surprising at first, but is quite a logical step, since most of the time you'll accept function names as parameters from calling functions within your script, which in turn are contained in zval containers again. Thus, you only have to pass your arguments through to this function. This zval must be of type IS_STRING.

The next argument consists of a pointer to the return value. You don't have to allocate memory for this container; the function will do so by itself. However, you have to destroy this container (using zval_dtor()) afterward!

Next is the parameter count as integer and an array containing all necessary parameters. The last argument specifies whether the function should perform zval separation - this should always be set to 0. If set to 1, the function consumes less memory but fails if any of the parameters need separation.

Example 38-1 shows a small demonstration of calling a user function. The code calls a function that's supplied to it as argument and directly passes this function's return value through as its own return value. Note the use of the constructor and destructor calls at the end - it might not be necessary to do it this way here (since they should be separate values, the assignment might be safe), but this is bulletproof.

Example 38-1. Calling user functions.

zval **function_name;
zval *retval;

if((ZEND_NUM_ARGS() != 1) || (zend_get_parameters_ex(1, &function_name) != SUCCESS))
{
    WRONG_PARAM_COUNT;
}

if((*function_name)->type != IS_STRING)
{
    zend_error(E_ERROR, "Function requires string argument");
}

TSRMSLS_FETCH();

if(call_user_function_ex(CG(function_table), NULL, *function_name, &retval, 0, NULL, 0) != SUCCESS)
{
    zend_error(E_ERROR, "Function call failed");
}

zend_printf("We have %i as type<br>", retval->type);

*return_value = *retval;
zval_copy_ctor(return_value);
zval_ptr_dtor(&retval);

<?php

dl("call_userland.so");

function test_function()
{

    print("We are in the test function!<br>");

    return("hello");

}

$return_value = call_userland("test_function");

print("Return value: \"$return_value\"<br>");
?>

Chapter 39. Initialization File Support

PHP 4 features a redesigned initialization file support. It's now possible to specify default initialization entries directly in your code, read and change these values at runtime, and create message handlers for change notifications.

To create an .ini section in your own module, use the macros PHP_INI_BEGIN() to mark the beginning of such a section and PHP_INI_END() to mark its end. In between you can use PHP_INI_ENTRY() to create entries.
PHP_INI_BEGIN() PHP_INI_ENTRY("first_ini_entry", "has_string_value", PHP_INI_ALL, NULL) PHP_INI_ENTRY("second_ini_entry", "2", PHP_INI_SYSTEM, OnChangeSecond) PHP_INI_ENTRY("third_ini_entry", "xyz", PHP_INI_USER, NULL) PHP_INI_END()
The PHP_INI_ENTRY() macro accepts four parameters: the entry name, the entry value, its change permissions, and a pointer to a change-notification handler. Both entry name and value must be specified as strings, regardless of whether they really are strings or integers.

The permissions are grouped into three sections:PHP_INI_SYSTEM allows a change only directly in the php.ini file; PHP_INI_USER allows a change to be overridden by a user at runtime using additional configuration files, such as .htaccess; and PHP_INI_ALL allows changes to be made without restrictions. There's also a fourth level, PHP_INI_PERDIR, for which we couldn't verify its behavior yet.

The fourth parameter consists of a pointer to a change-notification handler. Whenever one of these initialization entries is changed, this handler is called. Such a handler can be declared using the PHP_INI_MH macro:
PHP_INI_MH(OnChangeSecond); // handler for ini-entry "second_ini_entry" // specify ini-entries here PHP_INI_MH(OnChangeSecond) { zend_printf("Message caught, our ini entry has been changed to %s<br>", new_value); return(SUCCESS); }
The new value is given to the change handler as string in the variable new_value. When looking at the definition of PHP_INI_MH, you actually have a few parameters to use:
#define PHP_INI_MH(name) int name(php_ini_entry *entry, char *new_value, uint new_value_length, void *mh_arg1, void *mh_arg2, void *mh_arg3)
All these definitions can be found in php_ini.h. Your message handler will have access to a structure that contains the full entry, the new value, its length, and three optional arguments. These optional arguments can be specified with the additional macros PHP_INI_ENTRY1 (allowing one additional argument), PHP_INI_ENTRY2 (allowing two additional arguments), and PHP_INI_ENTRY3 (allowing three additional arguments).

The change-notification handlers should be used to cache initialization entries locally for faster access or to perform certain tasks that are required if a value changes. For example, if a constant connection to a certain host is required by a module and someone changes the hostname, automatically terminate the old connection and attempt a new one.

Access to initialization entries can also be handled with the macros shown in Table 39-1.

Table 39-1. Macros to Access Initialization Entries in PHP

Macro	Description
`INI_INT(name)`	Returns the current value of entry `name` as integer (long).
`INI_FLT(name)`	Returns the current value of entry `name` as float (double).
`INI_STR(name)`	Returns the current value of entry `name` as string. Note: This string is not duplicated, but instead points to internal data. Further access requires duplication to local memory.
`INI_BOOL(name)`	Returns the current value of entry `name` as Boolean (defined as `zend_bool`, which currently means `unsigned char`).
`INI_ORIG_INT(name)`	Returns the original value of entry `name` as integer (long).
`INI_ORIG_FLT(name)`	Returns the original value of entry `name` as float (double).
`INI_ORIG_STR(name)`	Returns the original value of entry `name` as string. Note: This string is not duplicated, but instead points to internal data. Further access requires duplication to local memory.
`INI_ORIG_BOOL(name)`	Returns the original value of entry `name` as Boolean (defined as `zend_bool`, which currently means `unsigned char`).

Finally, you have to introduce your initialization entries to PHP. This can be done in the module startup and shutdown functions, using the macros REGISTER_INI_ENTRIES() and UNREGISTER_INI_ENTRIES():
ZEND_MINIT_FUNCTION(mymodule) { REGISTER_INI_ENTRIES(); } ZEND_MSHUTDOWN_FUNCTION(mymodule) { UNREGISTER_INI_ENTRIES(); }

Chapter 40. Where to Go from Here

You've learned a lot about PHP. You now know how to create dynamic loadable modules and statically linked extensions. You've learned how PHP and Zend deal with internal storage of variables and how you can create and access these variables. You know quite a set of tool functions that do a lot of routine tasks such as printing informational texts, automatically introducing variables to the symbol table, and so on.

Even though this chapter often had a mostly "referential" character, we hope that it gave you insight on how to start writing your own extensions. For the sake of space, we had to leave out a lot; we suggest that you take the time to study the header files and some modules (especially the ones in the ext/standard directory and the MySQL module, as these implement commonly known functionality). This will give you an idea of how other people have used the API functions - particularly those that didn't make it into this chapter.

Chapter 41. Reference: Some Configuration Macros

`config.m4`

The file config.m4 is processed by buildconf and must contain all the instructions to be executed during configuration. For example, these can include tests for required external files, such as header files, libraries, and so on. PHP defines a set of macros that can be used in this process, the most useful of which are described in Table 41-1.

Table 41-1. M4 Macros for config.m4

Macro	Description
`AC_MSG_CHECKING(message)`	Prints a "checking <message>" text during `configure`.
`AC_MSG_RESULT(value)`	Gives the result to `AC_MSG_CHECKING`; should specify either `yes` or `no` as `value`.
`AC_MSG_ERROR(message)`	Prints `message` as error message during `configure` and aborts the script.
`AC_DEFINE(name,value,description)`	Adds `#define` to `php_config.h` with the value of `value` and a comment that says `description` (this is useful for conditional compilation of your module).
`AC_ADD_INCLUDE(path)`	Adds a compiler include path; for example, used if the module needs to add search paths for header files.
`AC_ADD_LIBRARY_WITH_PATH(libraryname,librarypath)`	Specifies an additional library to link.
`AC_ARG_WITH(modulename,description,unconditionaltest,conditionaltest)`	Quite a powerful macro, adding the module with `description` to the `configure --help` output. PHP checks whether the option `--with-<modulename>` is given to the `configure` script. If so, it runs the script `unconditionaltest` (for example, `--with-myext=yes`), in which case the value of the option is contained in the variable `$withval`. Otherwise, it executes `conditionaltest`.
`PHP_EXTENSION(modulename, [shared])`	This macro is a must to call for PHP to configure your extension. You can supply a second argument in addition to your module name, indicating whether you intend compilation as a shared module. This will result in a definition at compile time for your source as `COMPILE_DL_<modulename>`.

Chapter 42. API Macros

A set of macros was introduced into Zend's API that simplify access to zval containers (see Table 42-1).

Table 42-1. API Macros for Accessing zval Containers

Macro	Refers to
`Z_LVAL(zval)`	`(zval).value.lval`
`Z_DVAL(zval)`	`(zval).value.dval`
`Z_STRVAL(zval)`	`(zval).value.str.val`
`Z_STRLEN(zval)`	`(zval).value.str.len`
`Z_ARRVAL(zval)`	`(zval).value.ht`
`Z_LVAL_P(zval)`	`(*zval).value.lval`
`Z_DVAL_P(zval)`	`(*zval).value.dval`
`Z_STRVAL_P(zval_p)`	`(*zval).value.str.val`
`Z_STRLEN_P(zval_p)`	`(*zval).value.str.len`
`Z_ARRVAL_P(zval_p)`	`(*zval).value.ht`
`Z_LVAL_PP(zval_pp)`	`(**zval).value.lval`
`Z_DVAL_PP(zval_pp)`	`(**zval).value.dval`
`Z_STRVAL_PP(zval_pp)`	`(**zval).value.str.val`
`Z_STRLEN_PP(zval_pp)`	`(**zval).value.str.len`
`Z_ARRVAL_PP(zval_pp)`	`(**zval).value.ht`

Chapter 43. Streams API for PHP Extension Authors

Overview

The PHP Streams API introduces a unified approach to the handling of files and sockets in PHP extension. Using a single API with standard functions for common operations, the streams API allows your extension to access files, sockets, URLs, memory and script-defined objects. Streams is a run-time extensible API that allows dynamically loaded modules (and scripts!) to register new streams.

The aim of the Streams API is to make it comfortable for developers to open files, urls and other streamable data sources with a unified API that is easy to understand. The API is more or less based on the ANSI C stdio family of functions (with identical semantics for most of the main functions), so C programmers will have a feeling of familiarity with streams.

The streams API operates on a couple of different levels: at the base level, the API defines php_stream objects to represent streamable data sources. On a slightly higher level, the API defines php_stream_wrapper objects which "wrap" around the lower level API to provide support for retrieving data and meta-data from URLs.

Streams can be cast (converted) into other types of file-handles, so that they can be used with third-party libraries without a great deal of trouble. This allows those libraries to access data directly from URL sources. If your system has the fopencookie() function, you can even pass any PHP stream to any library that uses ANSI stdio!

Streams Basics

Using streams is very much like using ANSI stdio functions. The main difference is in how you obtain the stream handle to begin with. In most cases, you will use php_stream_open_wrapper() to obtain the stream handle. This function works very much like fopen, as can be seen from the example below:

Example 43-1. simple stream example that displays the PHP home page
php_stream * stream = php_stream_open_wrapper("http://www.php.net", "rb", REPORT_ERRORS, NULL); if (stream) { while(!php_stream_eof(stream)) { char buf[1024]; if (php_stream_gets(stream, buf, sizeof(buf))) { printf(buf); } else { break; } } php_stream_close(stream); }

The table below shows the Streams equivalents of the more common ANSI stdio functions. Unless noted otherwise, the semantics of the functions are identical.

Table 43-1. ANSI stdio equivalent functions in the Streams API

ANSI Stdio Function	PHP Streams Function	Notes
fopen	php_stream_open_wrapper	Streams includes additional parameters
fclose	php_stream_close
fgets	php_stream_gets
fread	php_stream_read	The nmemb parameter is assumed to have a value of 1, so the prototype looks more like read(2)
fwrite	php_stream_write	The nmemb parameter is assumed to have a value of 1, so the prototype looks more like write(2)
fseek	php_stream_seek
ftell	php_stream_tell
rewind	php_stream_rewind
feof	php_stream_eof
fgetc	php_stream_getc
fputc	php_stream_putc
fflush	php_stream_flush
puts	php_stream_puts	Same semantics as puts, NOT fputs
fstat	php_stream_stat	Streams has a richer stat structure

Streams Common API Reference

Table of Contents
php_stream_stat_path -- Gets the status for a file or URL
php_stream_stat -- Gets the status for the underlying storage associated with a stream
php_stream_open_wrapper -- Opens a stream on a file or URL
php_stream_read -- Read a number of bytes from a stream into a buffer
php_stream_write -- Write a number of bytes from a buffer to a stream
php_stream_eof -- Check for an end-of-file condition on a stream
php_stream_getc -- Read a single byte from a stream
php_stream_gets -- Read a line of data from a stream into a buffer
php_stream_close -- Close a stream
php_stream_flush -- Flush stream buffers to storage
php_stream_seek -- Reposition a stream
php_stream_tell -- Determine the position of a stream
php_stream_copy_to_stream -- Copy data from one stream to another
php_stream_copy_to_mem -- Copy data from stream and into an allocated buffer
php_stream_make_seekable -- Convert a stream into a stream is seekable
php_stream_cast -- Convert a stream into another form, such as a FILE* or socket
php_stream_can_cast -- Determines if a stream can be converted into another form, such as a FILE* or socket
php_stream_is_persistent -- Determines if a stream is a persistent stream
php_stream_is -- Determines if a stream is of a particular type
php_stream_passthru -- Outputs all remaining data from a stream
php_register_url_stream_wrapper -- Registers a wrapper with the Streams API
php_unregister_url_stream_wrapper -- Un-registers a wrapper from the Streams API
php_stream_open_wrapper_ex -- Opens a stream on a file or URL, specifying context
php_stream_open_wrapper_as_file -- Opens a stream on a file or URL, and converts to a FILE*

The 'b' character is ignored on all POSIX conforming systems which treat binary and text files in the same way. It is a good idea to specify the 'b' character whenever your stream is accessing data where the full 8 bits are important, so that your code will work when compiled on a system where the 'b' flag is important.

Any local files created by the streams API will have their initial permissions set according to the operating system defaults - under UNIX based systems this means that the umask of the process will be used. Under Windows, the file will be owned by the creating process. Any remote files will be created according to the URL wrapper that was used to open the file, and the credentials supplied to the remote server.

r: Open text file for reading. The stream is positioned at the beginning of the file.
r+: Open text file for reading and writing. The stream is positioned at the beginning of the file.
w: Truncate the file to zero length or create text file for writing. The stream is positioned at the beginning of the file.
w+: Open text file for reading and writing. The file is created if it does not exist, otherwise it is truncated. The stream is positioned at the beginning of the file.
a: Open for writing. The file is created if it does not exist. The stream is positioned at the end of the file.
a+: Open text file for reading and writing. The file is created if it does not exist. The stream is positioned at the end of the file.

options affects how the path/URL of the stream is interpreted, safe mode checks and actions taken if there is an error during opening of the stream. See Stream open options for more information about options.

If opened is not NULL, it will be set to a string containing the name of the actual file/resource that was opened. This is important when the options include USE_PATH, which causes the include_path to be searched for the file. You, the caller, are responsible for calling efree() on the filename returned in this parameter.

Note: If you specified STREAM_MUST_SEEK in options, the path returned in opened may not be the name of the actual stream that was returned to you. It will, however, be the name of the original resource from which the seekable stream was manufactured.

php_stream_read

(no version information, might be only in CVS)

php_stream_read -- Read a number of bytes from a stream into a buffer

Description

size_t php_stream_read ( php_stream * stream, char * buf, size_t count)

php_stream_read() reads up to count bytes of data from stream and copies them into the buffer buf.

php_stream_read() returns the number of bytes that were read successfully. There is no distinction between a failed read or an end-of-file condition - use php_stream_eof() to test for an EOF.

The internal position of the stream is advanced by the number of bytes that were read, so that subsequent reads will continue reading from that point.

If less than count bytes are available to be read, this call will block (or wait) until the required number are available, depending on the blocking status of the stream. By default, a stream is opened in blocking mode. When reading from regular files, the blocking mode will not usually make any difference: when the stream reaches the EOF php_stream_read() will return a value less than count, and 0 on subsequent reads.

php_stream_write

(no version information, might be only in CVS)

php_stream_write -- Write a number of bytes from a buffer to a stream

Description

size_t php_stream_write ( php_stream * stream, const char * buf, size_t count)

php_stream_write() writes count bytes of data from buf into stream.

php_stream_write() returns the number of bytes that were read successfully. If there was an error, the number of bytes written will be less than count.

The internal position of the stream is advanced by the number of bytes that were written, so that subsequent writes will continue writing from that point.

php_stream_eof

(no version information, might be only in CVS)

php_stream_eof -- Check for an end-of-file condition on a stream

Description

int php_stream_eof ( php_stream * stream)

php_stream_eof() checks for an end-of-file condition on stream.

php_stream_read() returns the 1 to indicate EOF, 0 if there is no EOF and -1 to indicate an error.

php_stream_getc

(no version information, might be only in CVS)

php_stream_getc -- Read a single byte from a stream

Description

int php_stream_getc ( php_stream * stream)

php_stream_getc() reads a single character from stream and returns it as an unsigned char cast as an int, or EOF if the end-of-file is reached, or an error occurred.

php_stream_getc() may block in the same way as php_stream_read() blocks.

The internal position of the stream is advanced by 1 if successful.

php_stream_gets

(no version information, might be only in CVS)

php_stream_gets -- Read a line of data from a stream into a buffer

Description

char * php_stream_gets ( php_stream * stream, char * buf, size_t maxlen)

php_stream_gets() reads up to count-1 bytes of data from stream and copies them into the buffer buf. Reading stops after an EOF or a newline. If a newline is read, it is stored in buf as part of the returned data. A NUL terminating character is stored as the last character in the buffer.

int php_stream_seek ( php_stream * stream, off_t offset, int whence)

php_stream_seek() repositions the internal position of stream. The new position is determined by adding the offset to the position indicated by whence. If whence is set to SEEK_SET, SEEK_CUR or SEEK_END the offset is relative to the start of the stream, the current position or the end of the stream, respectively.

php_stream_seek() returns 0 on success, but -1 if there was an error.

Note: Not all streams support seeking, although the streams API will emulate a seek if whence is set to SEEK_CUR and offset is positive, by calling php_stream_read() to read (and discard) offset bytes.
The emulation is only applied when the underlying stream implementation does not support seeking. If the stream is (for example) a file based stream that is wrapping a non-seekable pipe, the streams api will not apply emulation because the file based stream implements a seek operation; the seek will fail and an error result will be returned to the caller.

php_stream_tell

(no version information, might be only in CVS)

php_stream_tell -- Determine the position of a stream

Description

off_t php_stream_tell ( php_stream * stream)

php_stream_tell() returns the internal position of stream, relative to the start of the stream. If there is an error, -1 is returned.

php_stream_copy_to_stream

(no version information, might be only in CVS)

php_stream_copy_to_stream -- Copy data from one stream to another

Description

size_t php_stream_copy_to_stream ( php_stream * src, php_stream * dest, size_t maxlen)

php_stream_copy_to_stream() attempts to read up to maxlen bytes of data from src and write them to dest, and returns the number of bytes that were successfully copied.

If you want to copy all remaining data from the src stream, pass the constant PHP_STREAM_COPY_ALL as the value of maxlen.

Note: This function will attempt to copy the data in the most efficient manner, using memory mapped files when possible.

php_stream_copy_to_mem

(no version information, might be only in CVS)

php_stream_copy_to_mem -- Copy data from stream and into an allocated buffer

Description

size_t php_stream_copy_to_mem ( php_stream * src, char ** buf, size_t maxlen, int persistent)

php_stream_copy_to_mem() allocates a buffer maxlen+1 bytes in length using pemalloc() (passing persistent). It then reads maxlen bytes from src and stores them in the allocated buffer.

The allocated buffer is returned in buf, and the number of bytes successfully read. You, the caller, are responsible for freeing the buffer by passing it and persistent to pefree().

If you want to copy all remaining data from the src stream, pass the constant PHP_STREAM_COPY_ALL as the value of maxlen.

Note: This function will attempt to copy the data in the most efficient manner, using memory mapped files when possible.

php_stream_make_seekable

(no version information, might be only in CVS)

php_stream_make_seekable -- Convert a stream into a stream is seekable

Description

int php_stream_make_seekable ( php_stream * origstream, php_stream ** newstream, int flags)

php_stream_make_seekable() checks if origstream is seekable. If it is not, it will copy the data into a new temporary stream. If successful, newstream is always set to the stream that is valid to use, even if the original stream was seekable.

flags allows you to specify your preference for the seekeable stream that is returned: use PHP_STREAM_NO_PREFERENCE to use the default seekable stream (which uses a dynamically expanding memory buffer, but switches to temporary file backed storage when the stream size becomes large), or use PHP_STREAM_PREFER_STDIO to use "regular" temporary file backed storage.

Table 43-1. php_stream_make_seekable() return values

Value	Meaning
PHP_STREAM_UNCHANGED	Original stream was seekable anyway. `newstream` is set to the value of `origstream`.
PHP_STREAM_RELEASED	Original stream was not seekable and has been released. `newstream` is set to the new seekable stream. You should not access `origstream` anymore.
PHP_STREAM_FAILED	An error occurred while attempting conversion. `newstream` is set to NULL; `origstream` is still valid.
PHP_STREAM_CRITICAL	An error occurred while attempting conversion that has left `origstream` in an indeterminate state. `newstream` is set to NULL and it is highly recommended that you close `origstream`.

Note: If you need to seek and write to the stream, it does not make sense to use this function, because the stream it returns is not guaranteed to be bound to the same resource as the original stream.

Note: If you only need to seek forwards, there is no need to call this function, as the streams API will emulate forward seeks when the whence parameter is SEEK_CUR.

Note: If origstream is network based, this function will block until the whole contents have been downloaded.

Note: NEVER call this function with an origstream that is reference by a file pointer in a PHP script! This function may cause the underlying stream to be closed which could cause a crash when the script next accesses the file pointer!

Note: In many cases, this function can only succeed when origstream is a newly opened stream with no data buffered in the stream layer. For that reason, and because this function is complicated to use correctly, it is recommended that you use php_stream_open_wrapper() and pass in PHP_STREAM_MUST_SEEK in your options instead of calling this function directly.

php_stream_cast

(no version information, might be only in CVS)

php_stream_cast -- Convert a stream into another form, such as a FILE* or socket

Description

int php_stream_cast ( php_stream * stream, int castas, void ** ret, int flags)

php_stream_cast() attempts to convert stream into a resource indicated by castas. If ret is NULL, the stream is queried to find out if such a conversion is possible, without actually performing the conversion (however, some internal stream state *might* be changed in this case). If flags is set to REPORT_ERRORS, an error message will be displayed is there is an error during conversion.

Note: This function returns SUCCESS for success or FAILURE for failure. Be warned that you must explicitly compare the return value with SUCCESS or FAILURE because of the underlying values of those constants. A simple boolean expression will not be interpreted as you intended.

Table 43-1. Resource types for castas

Value	Meaning
PHP_STREAM_AS_STDIO	Requests an ANSI FILE* that represents the stream
PHP_STREAM_AS_FD	Requests a POSIX file descriptor that represents the stream
PHP_STREAM_AS_SOCKETD	Requests a network socket descriptor that represents the stream

In addition to the basic resource types above, the conversion process can be altered by using the following flags by using the OR operator to combine the resource type with one or more of the following values:

Table 43-2. Resource types for castas

Value	Meaning
PHP_STREAM_CAST_TRY_HARD	Tries as hard as possible, at the expense of additional resources, to ensure that the conversion succeeds
PHP_STREAM_CAST_RELEASE	Informs the streams API that some other code (possibly a third party library) will be responsible for closing the underlying handle/resource. This causes the `stream` to be closed in such a way the underlying handle is preserved and returned in `ret`. If this function succeeds, `stream` should be considered closed and should no longer be used.

Note: If your system supports fopencookie() (systems using glibc 2 or later), the streams API will always be able to synthesize an ANSI FILE* pointer over any stream. While this is tremendously useful for passing any PHP stream to any third-party libraries, such behaviour is not portable. You are requested to consider the portability implications before distributing you extension. If the fopencookie synthesis is not desireable, you should query the stream to see if it naturally supports FILE* by using php_stream_is()

Note: If you ask a socket based stream for a FILE*, the streams API will use fdopen() to create it for you. Be warned that doing do may cause data that was buffered in the streams layer to be lost if you intermix streams API calls with ANSI stdio calls.

See also php_stream_is() and php_stream_can_cast().

php_stream_can_cast

(no version information, might be only in CVS)

php_stream_can_cast -- Determines if a stream can be converted into another form, such as a FILE* or socket

Description

int php_stream_can_cast ( php_stream * stream, int castas)

This function is equivalent to calling php_stream_cast() with ret set to NULL and flags set to 0. It returns SUCCESS if the stream can be converted into the form requested, or FAILURE if the conversion cannot be performed.

Note: Although this function will not perform the conversion, some internal stream state *might* be changed by this call.

Note: You must explicity compare the return value of this function with one of the constants, as described in php_stream_cast().

See also php_stream_cast() and php_stream_is().

php_stream_is_persistent

(no version information, might be only in CVS)

php_stream_is_persistent -- Determines if a stream is a persistent stream

Description

int php_stream_is_persistent ( php_stream * stream)

php_stream_is_persistent() returns 1 if the stream is a persistent stream, 0 otherwise.

php_stream_is

(no version information, might be only in CVS)

php_stream_is -- Determines if a stream is of a particular type

Description

int php_stream_is ( php_stream * stream, int istype)

php_stream_is() returns 1 if stream is of the type specified by istype, or 0 otherwise.

Table 43-1. Values for istype

Value	Meaning
PHP_STREAM_IS_STDIO	The stream is implemented using the stdio implementation
PHP_STREAM_IS_SOCKET	The stream is implemented using the network stream implementation
PHP_STREAM_IS_USERSPACE	The stream is implemented using the userspace object implementation
PHP_STREAM_IS_MEMORY	The stream is implemented using the grow-on-demand memory stream implementation

Note: The PHP_STREAM_IS_XXX "constants" are actually defined as pointers to the underlying stream operations structure. If your extension (or some other extension) defines additional streams, it should also declare a PHP_STREAM_IS_XXX constant in it's header file that you can use as the basis of this comparison.

Note: This function is implemented as a simple (and fast) pointer comparision, and does not change the stream state in any way.

See also php_stream_cast() and php_stream_can_cast().

php_stream_passthru

(no version information, might be only in CVS)

php_stream_passthru -- Outputs all remaining data from a stream

Description

size_t php_stream_passthru ( php_stream * stream)

php_stream_passthru() outputs all remaining data from stream to the active output buffer and returns the number of bytes output. If buffering is disabled, the data is written straight to the output, which is the browser making the request in the case of PHP on a web server, or stdout for CLI based PHP. This function will use memory mapped files if possible to help improve performance.

php_register_url_stream_wrapper

(no version information, might be only in CVS)

php_register_url_stream_wrapper -- Registers a wrapper with the Streams API

Description

int php_register_url_stream_wrapper ( char * protocol, php_stream_wrapper * wrapper, TSRMLS_DC )

php_register_url_stream_wrapper() registers wrapper as the handler for the protocol specified by protocol.

Note: If you call this function from a loadable module, you *MUST* call php_unregister_url_stream_wrapper() in your module shutdown function, otherwise PHP will crash.

Streams File API Reference

Table of Contents
php_stream_fopen_from_file -- Convert an ANSI FILE* into a stream
php_stream_fopen_tmpfile -- Open a FILE* with tmpfile() and convert into a stream
php_stream_fopen_temporary_file -- Generate a temporary file name and open a stream on it

Streams Socket API Reference

Table of Contents
php_stream_sock_open_from_socket -- Convert a socket descriptor into a stream
php_stream_sock_open_host -- Open a connection to a host and return a stream
php_stream_sock_open_unix -- Open a UNIX domain socket and convert into a stream

php_stream_sock_open_from_socket

(no version information, might be only in CVS)

php_stream_sock_open_from_socket -- Convert a socket descriptor into a stream

Description

php_stream * php_stream_sock_open_from_socket ( int socket, int persistent)

php_stream_sock_open_from_socket() returns a stream based on the socket. persistent is a flag that controls whether the stream is opened as a persistent stream. Generally speaking, this parameter will usually be 0.

php_stream_sock_open_host

(no version information, might be only in CVS)

php_stream_sock_open_host -- Open a connection to a host and return a stream

Description

php_stream * php_stream_sock_open_host ( const char * host, unsigned short port, int socktype, struct timeval * timeout, int persistent)

php_stream_sock_open_host() establishes a connect to the specified host and port. socktype specifies the connection semantics that should apply to the connection. Values for socktype are system dependent, but will usually include (at a minimum) SOCK_STREAM for sequenced, reliable, two-way connection based streams (TCP), or SOCK_DGRAM for connectionless, unreliable messages of a fixed maximum length (UDP).

persistent is a flag the controls whether the stream is opened as a persistent stream. Generally speaking, this parameter will usually be 0.

If not NULL, timeout specifies a maximum time to allow for the connection to be made. If the connection attempt takes longer than the timeout value, the connection attempt is aborted and NULL is returned to indicate that the stream could not be opened.

Note: The timeout value does not include the time taken to perform a DNS lookup. The reason for this is because there is no portable way to implement a non-blocking DNS lookup.
The timeout only applies to the connection phase; if you need to set timeouts for subsequent read or write operations, you should use php_stream_sock_set_timeout() to configure the timeout duration for your stream once it has been opened.

The streams API places no restrictions on the values you use for socktype, but encourages you to consider the portability of values you choose before you release your extension.

php_stream_sock_open_unix

(no version information, might be only in CVS)

php_stream_sock_open_unix -- Open a UNIX domain socket and convert into a stream

Description

php_stream * php_stream_sock_open_unix ( const char * path, int pathlen, int persistent, struct timeval * timeout)

php_stream_sock_open_unix() attempts to open the UNIX domain socket specified by path. pathlen specifies the length of path. If timeout is not NULL, it specifies a timeout period for the connection attempt. persistent indicates if the stream should be opened as a persistent stream. Generally speaking, this parameter will usually be 0.

Note: This function will not work under Windows, which does not implement unix domain sockets. A possible exception to this rule is if your PHP binary was built using cygwin. You are encouraged to consider this aspect of the portability of your extension before it's release.

Note: This function treats path in a binary safe manner, suitable for use on systems with an abstract namespace (such as Linux), where the first character of path is a NUL character.

Streams Structures

Table of Contents
struct php_stream_statbuf -- Holds information about a file or URL
struct php_stream_dirent -- Holds information about a single file during dir scanning

struct php_stream_statbuf

struct php_stream_statbuf -- Holds information about a file or URL

Description

php_stream_statbuf
     struct stat sb

sb is a regular, system defined, struct stat.

struct php_stream_dirent

struct php_stream_dirent -- Holds information about a single file during dir scanning

Description

php_stream_dirent
     char d_name[MAXPATHLEN]

d_name holds the name of the file, relative to the directory being scanned.

Streams Constants

Table of Contents
Stream open options -- Affects the operation of stream factory functions

Stream open options

Stream open options -- Affects the operation of stream factory functions

Description

One or more of these values can be combined using the OR operator.

IGNORE_PATH

This is the default option for streams; it requests that the include_path is not to be searched for the requested file.

USE_PATH

Requests that the include_path is to be searched for the requested file.

IGNORE_URL

Requests that registered URL wrappers are to be ignored when opening the stream. Other non-URL wrappers will be taken into consideration when decoding the path. There is no opposite form for this flag; the streams API will use all registered wrappers by default.

IGNORE_URL_WIN

On Windows systems, this is equivalent to IGNORE_URL. On all other systems, this flag has no effect.

ENFORCE_SAFE_MODE

Requests that the underlying stream implementation perform safe_mode checks on the file before opening the file. Omitting this flag will skip safe_mode checks and allow opening of any file that the PHP process has rights to access.

REPORT_ERRORS

If this flag is set, and there was an error during the opening of the file or URL, the streams API will call the php_error function for you. This is useful because the path may contain username/password information that should not be displayed in the browser output (it would be a security risk to do so). When the streams API raises the error, it first strips username/password information from the path, making the error message safe to display in the browser.

STREAM_MUST_SEEK

This flag is useful when your extension really must be able to randomly seek around in a stream. Some streams may not be seekable in their native form, so this flag asks the streams API to check to see if the stream does support seeking. If it does not, it will copy the stream into temporary storage (which may be a temporary file or a memory stream) which does support seeking. Please note that this flag is not useful when you want to seek the stream and write to it, because the stream you are accessing might not be bound to the actual resource you requested.

Note: If the requested resource is network based, this flag will cause the opener to block until the whole contents have been downloaded.

STREAM_WILL_CAST

If your extension is using a third-party library that expects a FILE* or file descriptor, you can use this flag to request the streams API to open the resource but avoid buffering. You can then use php_stream_cast() to retrieve the FILE* or file descriptor that the library requires.

The is particularly useful when accessing HTTP URLs where the start of the actual stream data is found after an indeterminate offset into the stream.

Since this option disables buffering at the streams API level, you may experience lower performance when using streams functions on the stream; this is deemed acceptable because you have told streams that you will be using the functions to match the underlying stream implementation. Only use this option when you are sure you need it.

VI. FAQ: Frequently Asked Questions

Table of Contents
44. General Information
45. Mailing lists
46. Obtaining PHP
47. Database issues
48. Installation
49. Build Problems
50. Using PHP
51. PHP and HTML
52. PHP and COM
53. PHP and other languages
54. Migrating from PHP 2 to PHP 3
55. Migrating from PHP 3 to PHP 4
56. Miscellaneous Questions

Chapter 44. General Information

This section holds the most general questions about PHP: what it is and what it does.

1. What is PHP?
2. What does PHP stand for?
3. What is the relation between the versions?
4. Can I run several versions of PHP at the same time?
5. What are the differences between PHP 3 and PHP 4?
6. I think I found a bug! Who should I tell?

1. What is PHP?

From the preface of the manual:

PHP is an HTML-embedded scripting language. Much of its syntax is borrowed from C, Java and Perl with a couple of unique PHP-specific features thrown in. The goal of the language is to allow web developers to write dynamically generated pages quickly.

A nice introduction to PHP by Stig Sæther Bakken can be found here on the Zend website. Also, much of the PHP Conference Material is freely available.

2. What does PHP stand for?

PHP stands for PHP: Hypertext Preprocessor. This confuses many people because the first word of the acronym is the acronym. This type of acronym is called a recursive acronym. The curious can visit Free On-Line Dictionary of Computing for more information on recursive acronyms.

3. What is the relation between the versions?

PHP/FI 2.0 is an early and no longer supported version of PHP. PHP 3 is the successor to PHP/FI 2.0 and is a lot nicer. PHP 4 is the latest generation of PHP, which uses the Zend engine under the hood.

4. Can I run several versions of PHP at the same time?

Yes. See the INSTALL file that is included in the PHP 4 source distribution. Also, read the related appendix.

5. What are the differences between PHP 3 and PHP 4?

There are a couple of articles written on this by the authors of PHP 4. Here's a list of some of the more important new features:

Extended API module
Generalized build process under UNIX
Generic web server interface that also supports multi-threaded web servers
Improved syntax highlighter
Native HTTP session support
Output buffering support
More powerful configuration system
Reference counting

Please see the What's new in PHP 4 overview for a detailed explanation of these features and more. If you're migrating from PHP 3 to PHP 4, also read the related appendix.

6. I think I found a bug! Who should I tell?

You should go to the PHP Bug Database and make sure the bug isn't a known bug. If you don't see it in the database, use the reporting form to report the bug. It is important to use the bug database instead of just sending an email to one of the mailing lists because the bug will have a tracking number assigned and it will then be possible for you to go back later and check on the status of the bug. The bug database can be found at http://bugs.php.net/.

Chapter 45. Mailing lists

This section holds questions about how to get in touch with the PHP community. The best way is the mailing lists.

1. Are there any PHP mailing lists?
2. Are there any other communities?
3. Help! I can't seem to subscribe/unsubscribe to/from one of the mailing lists!
4. Is there an archive of the mailing lists anywhere?
5. What can I ask the mailing list?
6. What information should I include when posting to the mailing list?

1. Are there any PHP mailing lists?

Of course! There are many mailing lists for several subjects. A whole list of mailing lists can be found on our Support page.

The most general mailing list is php-general. To subscribe, send mail to php-general-subscribe@lists.php.net. You don't need to include anything special in the subject or body of the message. To unsubscribe, send mail to php-general-unsubscribe@lists.php.net.

You can also subscribe and unsubscribe using the web interface on our Support page.

2. Are there any other communities?

There are countless of them around the world. We have links for example to some IRC servers and foreign language mailing lists on our Support page.

3. Help! I can't seem to subscribe/unsubscribe to/from one of the mailing lists!

If you have problems subscribing to or unsubscribing from the php-general mailing list, it may be because the mailing list software can't figure out the correct mailing address to use. If your email address was joeblow@example.com, you can send your subscription request to php-general-subscribe-joeblow=example.com@lists.php.net, or your unsubscription request to php-general-unsubscribe-joeblow=example.com@lists.php.net. Use similar addresses for the other mailing lists.

4. Is there an archive of the mailing lists anywhere?

Yes, you will find a list of archive sites on the Support page. The mailing list articles are also archived as news messages. You can access the news server at news://news.php.net/ with a news client. There is also an experimental web interface for the news server at http://news.php.net/

5. What can I ask the mailing list?

Since PHP is growing more and more popular by the day the traffic has increased on the php-general mailing list and as of now the list gets about 150 to 200 posts a day. Because of this it is in everyones interest that you use the list as a last resort when you have looked everywhere else.

Before you post to the list please have a look in this FAQ and the manual to see if you can find the help there. If there is nothing to be found there try out the mailing list archives (see above). If you're having problem with installing or configuring PHP please read through all included documentation and README's. If you still can't find any information that helps you out you're more than welcome to use the mailing list.

6. What information should I include when posting to the mailing list?

Posts like "I can't get PHP up and running! Help me! What is wrong?" are of absolutely no use to anyone. If you're having problems getting PHP up and running you must include what operating system you are running on, what version of PHP you're trying to set up, how you got it (pre-compiled, CVS, RPMs and so on), what you have done so far, where you got stuck and the exact error message.

This goes for any other problem as well. You have to include information on what you have done, where you got stuck, what you're trying to do and, if applicable, exact error messages. If you're having problems with your source code you need to include the part of the code that isn't working. Do not include more code than necessary though! It makes the post hard to read and a lot of people might just skip it all together because of this. If you're unsure about how much information to include in the mail it's better that you include to much than to little.

Another important thing to remember is to summarize your problem on the subject line. A subject like "HELP MEEEE!!!" or "What is the problem here?" will be ignored by the majority of the readers.

Chapter 46. Obtaining PHP

This section has details about PHP download locations, and OS issues.

1. Where can I obtain PHP?
2. Are pre-compiled binary versions available?
3. Where can I get libraries needed to compile some of the optional PHP extensions?
4. How do I get these libraries to work?
5. I got the latest version of the PHP source code from the CVS repository on my Windows machine, what do I need to compile it?
6. Where do I find the Browser Capabilities File?

1. Where can I obtain PHP?

You can download PHP from any of the members of the PHP network of sites. These can be found at http://www.php.net/. You can also use anonymous CVS to get the absolute latest version of the source. For more information, go to http://cvs.php.net/.

2. Are pre-compiled binary versions available?

We only distribute precompiled binaries for Windows systems, as we are not able to compile PHP for every major Linux/Unix platform with every extension combination. Also note, that many Linux distributions come with PHP built in these days. Windows binaries can be downloaded from our Downloads page, for Linux binaries, please visit your distributions website.

3. Where can I get libraries needed to compile some of the optional PHP extensions?

Note: Those marked with * are not thread-safe libraries, and should not be used with PHP as a server module in the multi-threaded Windows web servers (IIS, Netscape). This does not matter in Unix environments, yet.

LDAP (Unix).
LDAP* (Unix).
LDAP (Unix/Win) : Netscape Directory (LDAP) SDK 1.1.
free LDAP server.
Berkeley DB2 (Unix/Win) : http://www.sleepycat.com/.
SNMP* (Unix): .
GD* (Unix/Win).
mSQL* (Win).
mSQL* (Unix).
PostgreSQL (Unix).
IMAP* (Win/Unix).
Sybase-CT* (Linux, libc5) : Available locally.
FreeType (libttf):.
ZLib (Unix/Win32).
expat XML parser (Unix/Win32).
PDFLib.
mcrypt.
mhash.
t1lib.
dmalloc.
aspell.
readline.

4. How do I get these libraries to work?

You will need to follow instructions provided with the library. Some of these libraries are detected automatically when you run the 'configure' script of PHP (such as the GD library), and others you will have to enable using '--with-EXTENSION' options to 'configure'. Run 'configure --help' for a listing of these.

5. I got the latest version of the PHP source code from the CVS repository on my Windows machine, what do I need to compile it?

First, you will need Microsoft Visual C++ v6 (v5 may do it also, but we do it with v6), and you will need some support files. See the manual section about building PHP from source on Windows.

6. Where do I find the Browser Capabilities File?

You can find a browscap.ini file at http://www.garykeith.com/browsers/downloads.asp.

Chapter 47. Database issues

This section holds common questions about relation between PHP and databases. Yes, PHP can access virtually any database available today.

1. I heard it's possible to access Microsoft SQL Server from PHP. How?
2. Can I access Microsoft Access databases?
3. I upgraded to PHP 4, and now mysql keeps telling me "Warning: MySQL: Unable to save result set in ...". What's up?
4. After installing shared MySQL support, Apache dumps core as soon as libphp4.so is loaded. Can this be fixed?
5. Why do I get an error that looks something like this: "Warning: 0 is not a MySQL result index in <file> on line <x>" or "Warning: Supplied argument is not a valid MySQL result resource in <file> on line <x>?

1. I heard it's possible to access Microsoft SQL Server from PHP. How?

On Windows machines, you can simply use the included ODBC support and the correct ODBC driver.

On Unix machines, you can use the Sybase-CT driver to access Microsoft SQL Servers because they are (at least mostly) protocol-compatible. Sybase has made a free version of the necessary libraries for Linux systems. For other Unix operating systems, you need to contact Sybase for the correct libraries. Also see the answer to the next question.

2. Can I access Microsoft Access databases?

Yes. You already have all the tools you need if you are running entirely under Windows 9x/Me, or NT/2000, where you can use ODBC and Microsoft's ODBC drivers for Microsoft Access databases.

If you are running PHP on a Unix box and want to talk to MS Access on a Windows box you will need Unix ODBC drivers. OpenLink Software has Unix-based ODBC drivers that can do this. There is a free pilot program where you can download an evaluation copy that doesn't expire and prices start at $675 for the commercial supported version.

Another alternative is to use an SQL server that has Windows ODBC drivers and use that to store the data, which you can then access from Microsoft Access (using ODBC) and PHP (using the built in drivers), or to use an intermediary file format that Access and PHP both understand, such as flat files or dBase databases. On this point Tim Hayes from OpenLink software writes:
Using another database as an intermediary is not a good idea, when you can use ODBC from PHP straight to your database - i.e. with OpenLink's drivers. If you do need to use an intermediary file format, OpenLink have now released Virtuoso (a virtual database engine) for NT, Linux and other unix platforms. Please visit our website for a free download.

One option that has proven successful is to use MySQL and its MyODBC drivers on Windows and synchronizing the databases. Steve Lawrence writes:

Install MySQL on your platform according to instructions with MySQL. Latest available from www.mysql.com (get it from your mirror!). No special configuration required except when you set up a database, and configure the user account, you should put % in the host field, or the host name of the Windows computer you wish to access MySQL with. Make a note of your server name, username, and password.
Download the MyODBC for Windows driver from the MySQL site. Latest release is myodbc-2_50_19-win95.zip (NT available too, as well as source code). Install it on your Windows machine. You can test the operation with the utilities included with this program.
Create a user or system dsn in your ODBC administrator, located in the control panel. Make up a dsn name, enter your hostname, user name, password, port, etc for you MySQL database configured in step 1.
Install Access with a full install, this makes sure you get the proper add-ins.. at the least you will need ODBC support and the linked table manager.
Now the fun part! Create a new access database. In the table window right click and select Link Tables, or under the file menu option, select Get External Data and then Link Tables. When the file browser box comes up, select files of type: ODBC. Select System dsn and the name of your dsn created in step 3. Select the table to link, press OK, and presto! You can now open the table and add/delete/edit data on your MySQL server! You can also build queries, import/export tables to MySQL, build forms and reports, etc.

Tips and Tricks:

You can construct your tables in Access and export them to MySQL, then link them back in. That makes table creation quick.
When creating tables in Access, you must have a primary key defined in order to have write access to the table in access. Make sure you create a primary key in MySQL before linking in access
If you change a table in MySQL, you have to re-link it in Access. Go to tools>add-ins>linked table manager, cruise to your ODBC DSN, and select the table to re-link from there. you can also move your dsn source around there, just hit the always prompt for new location checkbox before pressing OK.

3. I upgraded to PHP 4, and now mysql keeps telling me "Warning: MySQL: Unable to save result set in ...". What's up?

Most likely what has happened is, PHP 4 was compiled with the '--with-mysql' option, without specifying the path to MySQL. This means PHP is using its built-in MySQL client library. If your system is running applications, such as PHP 3 as a concurrent Apache module, or auth-mysql, that use other versions of MySQL clients, then there is a conflict between the two differing versions of those clients.

Recompiling PHP 4, and adding the path to MySQL to the flag, '--with-mysql=/your/path/to/mysql' usually solves the problem.

4. After installing shared MySQL support, Apache dumps core as soon as libphp4.so is loaded. Can this be fixed?

If your MySQL libs are linked against pthreads this will happen. Check using ldd. If they are, grab the MySQL tarball and compile from source, or recompile from the source rpm and remove the switch in the spec file that turns on the threaded client code. Either of these suggestions will fix this. Then recompile PHP with the new MySQL libs.

5. Why do I get an error that looks something like this: "Warning: 0 is not a MySQL result index in <file> on line <x>" or "Warning: Supplied argument is not a valid MySQL result resource in <file> on line <x>?

You are trying to use a result identifier that is 0. The 0 indicates that your query failed for some reason. You need to check for errors after submitting a query and before you attempt to use the returned result identifier. The proper way to do this is with code similar to the following:
$result = mysql_query("SELECT * FROM tables_priv"); if (!$result) { echo mysql_error(); exit; }
or
$result = mysql_query("SELECT * FROM tables_priv") or die("Bad query: ".mysql_error());

Chapter 48. Installation

This section holds common questions about the way to install PHP. PHP is available for almost any OS (except maybe for MacOS before OSX), and almost any web server.

To install PHP, follow the instructions in the INSTALL file located in the distribution. Windows users should also read the install.txt file. There are also some helpful hints for Windows users here.

1. Unix/Windows: Where should my php.ini file be located?
2. Unix: I installed PHP, but every time I load a document, I get the message 'Document Contains No Data'! What's going on here?
3. Unix: I installed PHP using RPMS, but Apache isn't processing the PHP pages! What's going on here?
4. Unix: I installed PHP 3 using RPMS, but it doesn't compile with the database support I need! What's going on here?
5. Unix: I patched Apache with the FrontPage extensions patch, and suddenly PHP stopped working. Is PHP incompatible with the Apache FrontPage extensions?
6. Unix/Windows: I have installed PHP, but when I try to access a PHP script file via my browser, I get a blank screen.
7. Unix/Windows: I have installed PHP, but when try to access a PHP script file via my browser, I get a server 500 error.
8. Some operating systems: I have installed PHP without errors, but when I try to start apache I get undefined symbol errors: [mybox:user /src/php4] root# apachectl configtest apachectl: /usr/local/apache/bin/httpd Undefined symbols: _compress _uncompress
9. Windows: I have installed PHP, but when I to access a PHP script file via my browser, I get the error: cgi error: The specified CGI application misbehaved by not returning a complete set of HTTP headers. The headers it did return are:
10. Windows: I've followed all the instructions, but still can't get PHP and IIS to work together!

1. Unix/Windows: Where should my php.ini file be located?

By default on UNIX it should be in /usr/local/lib which is <install-path>/lib. Most people will want to change this at compile-time with the --with-config-file-path flag. You would, for example, set it with something like:
--with-config-file-path=/etc
And then you would copy php.ini-dist from the distribution to /etc/php.ini and edit it to make any local changes you want.

On Windows the default path for the php.ini file is the Windows directory. If you're using the Apache webserver, php.ini is first searched in the Apaches install directory, e.g. c:\program files\apache group\apache. This way you can have different php.ini files for different versions of Apache on the same machine.

See also the chapter about the configuration file.

2. Unix: I installed PHP, but every time I load a document, I get the message 'Document Contains No Data'! What's going on here?

This probably means that PHP is having some sort of problem and is core-dumping. Look in your server error log to see if this is the case, and then try to reproduce the problem with a small test case. If you know how to use 'gdb', it is very helpful when you can provide a backtrace with your bug report to help the developers pinpoint the problem. If you are using PHP as an Apache module try something like:

Stop your httpd processes
gdb httpd
Stop your httpd processes
> run -X -f /path/to/httpd.conf
Then fetch the URL causing the problem with your browser
> run -X -f /path/to/httpd.conf
If you are getting a core dump, gdb should inform you of this now
type: bt
You should include your backtrace in your bug report. This should be submitted to http://bugs.php.net/

If your script uses the regular expression functions (ereg() and friends), you should make sure that you compiled PHP and Apache with the same regular expression package. This should happen automatically with PHP and Apache 1.3.x

3. Unix: I installed PHP using RPMS, but Apache isn't processing the PHP pages! What's going on here?

Assuming you installed both Apache and PHP from RPM packages, you need to uncomment or add some or all of the following lines in your http.conf file:
# Extra Modules AddModule mod_php.c AddModule mod_php3.c AddModule mod_perl.c # Extra Modules LoadModule php_module modules/mod_php.so LoadModule php3_module modules/libphp3.so /* for PHP 3 */ LoadModule php4_module modules/libphp4.so /* for PHP 4 */ LoadModule perl_module modules/libperl.so
And add:
AddType application/x-httpd-php3 .php3 /* for PHP 3 */ AddType application/x-httpd-php .php /* for PHP 4 */
... to the global properties, or to the properties of the VirtualDomain you want to have PHP support added to.

4. Unix: I installed PHP 3 using RPMS, but it doesn't compile with the database support I need! What's going on here?

Due to the way PHP 3 built, it is not easy to build a complete flexible PHP RPM. This issue is addressed in PHP 4. For PHP 3, we currently suggest you use the mechanism described in the INSTALL.REDHAT file in the PHP distribution. If you insist on using an RPM version of PHP 3, read on...

The RPM packagers are setting up the RPMS to install without database support to simplify installations and because RPMS use /usr/ instead of the standard /usr/local/ directory for files. You need to tell the RPM spec file which databases to support and the location of the top-level of your database server.

This example will explain the process of adding support for the popular MySQL database server, using the mod installation for Apache.

Of course all of this information can be adjusted for any database server that PHP supports. We will assume you installed MySQL and Apache completely with RPMS for this example as well.

First remove mod_php3 :
rpm -e mod_php3
Then get the source rpm and INSTALL it, NOT --rebuild
rpm -Uvh mod_php3-3.0.5-2.src.rpm

Then edit the /usr/src/redhat/SPECS/mod_php3.spec file

In the %build section add the database support you want, and the path.

For MySQL you would add
--with-mysql=/usr \
The %build section will look something like this:
./configure --prefix=/usr \ --with-apxs=/usr/sbin/apxs \ --with-config-file-path=/usr/lib \ --enable-debug=no \ --enable-safe-mode \ --with-exec-dir=/usr/bin \ --with-mysql=/usr \ --with-system-regex

Once this modification is made then build the binary rpm as follows:
rpm -bb /usr/src/redhat/SPECS/mod_php3.spec

Then install the rpm
rpm -ivh /usr/src/redhat/RPMS/i386/mod_php3-3.0.5-2.i386.rpm

Make sure you restart Apache, and you now have PHP 3 with MySQL support using RPM's. Note that it is probably much easier to just build from the distribution tarball of PHP 3 and follow the instructions in INSTALL.REDHAT found in that distribution.

5. Unix: I patched Apache with the FrontPage extensions patch, and suddenly PHP stopped working. Is PHP incompatible with the Apache FrontPage extensions?

No, PHP works fine with the FrontPage extensions. The problem is that the FrontPage patch modifies several Apache structures, that PHP relies on. Recompiling PHP (using 'make clean ; make') after the FP patch is applied would solve the problem.

6. Unix/Windows: I have installed PHP, but when I try to access a PHP script file via my browser, I get a blank screen.

Do a 'view source' in the web browser and you will probably find that you can see the source code of your PHP script. This means that the web server did not send the script to PHP for interpretation. Something is wrong with the server configuration - double check the server configuration against the PHP installation instructions.

7. Unix/Windows: I have installed PHP, but when try to access a PHP script file via my browser, I get a server 500 error.

Something went wrong when the server tried to run PHP. To get to see a sensible error message, from the command line, change to the directory containing the PHP executable (php.exe on Windows) and run php -i. If PHP has any problems running, then a suitable error message will be displayed which will give you a clue as to what needs to be done next. If you get a screen full of html codes (the output of the phpinfo() function) then PHP is working, and your problem may be related to your server configuration which you should double check.

8. Some operating systems: I have installed PHP without errors, but when I try to start apache I get undefined symbol errors:
[mybox:user /src/php4] root# apachectl configtest apachectl: /usr/local/apache/bin/httpd Undefined symbols: _compress _uncompress

This has actually nothing to do with PHP, but with the MySQL client libraries. Some need --with-zlib, others do not. This is also covered in the MySQL FAQ.

9. Windows: I have installed PHP, but when I to access a PHP script file via my browser, I get the error:
cgi error: The specified CGI application misbehaved by not returning a complete set of HTTP headers. The headers it did return are:

This error message means that PHP failed to output anything at all. To get to see a sensible error message, from the command line, change to the directory containing the PHP executable (php.exe on Windows) and run php -i. If PHP has any problems running, then a suitable error message will be displayed which will give you a clue as to what needs to be done next. If you get a screen full of html codes (the output of the phpinfo() function) then PHP is working.

Once PHP is working at the command line, try accessing the script via the browser again. If it still fails then it could be one of the following:

File permissions on your PHP script, php.exe, php4ts.dll, php.ini or any PHP extensions you are trying to load are such that the anonymous internet user ISUR_<machinename> cannot access them.
The script file does not exist (or possibly isn't where you think it is relative to your web root directory). Note that for IIS you can trap this error by ticking the 'check file exists' box when setting up the script mappings in the Internet Services Manager. If a script file does not exist then the server will return a 404 error instead. There is also the additional benefit that IIS will do any authentication required for you based on the NTLanMan permissions on your script file.

10. Windows: I've followed all the instructions, but still can't get PHP and IIS to work together!

Make sure any user who needs to run a PHP script has the rights to run php.exe! IIS uses an anonymous user which is added at the time IIS is installed. This user needs rights to php.exe. Also, any authenticated user will also need rights to execute php.exe. And for IIS4 you need to tell it that PHP is a script engine.

Chapter 49. Build Problems

This section gathers most common errors that occur at build time.

1. I got the latest version of PHP using the anonymous CVS service, but there's no configure script!
2. I'm having problems configuring PHP to work with Apache. It says it can't find httpd.h, but it's right where I said it is!
3. When I run configure, it says that it can't find the include files or library for GD, gdbm, or some other package!
4. When it is compiling the file language-parser.tab.c, it gives me errors that say yytname undeclared.
5. When I run make, it seems to run fine but then fails when it tries to link the final application complaining that it can't find some files.
6. When linking PHP, it complains about a number of undefined references.
7. I can't figure out how to build PHP with Apache 1.3.
8. I have followed all the steps to install the Apache module version on UNIX, and my PHP scripts show up in my browser or I am being asked to save the file.
9. It says to use: --activate-module=src/modules/php4/libphp4.a, but that file doesn't exist, so I changed it to --activate-module=src/modules/php4/libmodphp4.a and it doesn't work!? What's going on?
10. When I try to build Apache with PHP as a static module using --activate-module=src/modules/php4/libphp4.a it tells me that my compiler is not ANSI compliant.
11. When I try to build PHP using --with-apxs I get strange error messages.
12. During make, I get errors in microtime, and a lot of RUSAGE_ stuff.
13. I want to upgrade my PHP. Where can I find the ./configure line that was used to build my current PHP installation?
14. When building PHP with the GD library it either gives strange compile errors or segfaults on execution.

1. I got the latest version of PHP using the anonymous CVS service, but there's no configure script!

You have to have the GNU autoconf package installed so you can generate the configure script from configure.in. Just run ./buildconf in the top-level directory after getting the sources from the CVS server. (Also, unless you run configure with the --enable-maintainer-mode option, the configure script will not automatically get rebuilt when the configure.in file is updated, so you should make sure to do that manually when you notice configure.in has changed. One symptom of this is finding things like @VARIABLE@ in your Makefile after configure or config.status is run.)

2. I'm having problems configuring PHP to work with Apache. It says it can't find httpd.h, but it's right where I said it is!

You need to tell the configure/setup script the location of the top-level of your Apache source tree. This means that you want to specify --with-apache=/path/to/apache and not --with-apache=/path/to/apache/src.

3. When I run configure, it says that it can't find the include files or library for GD, gdbm, or some other package!

You can make the configure script looks for header files and libraries in non-standard locations by specifying additional flags to pass to the C preprocessor and linker, such as:
CPPFLAGS=-I/path/to/include LDFLAGS=-L/path/to/library ./configure
If you're using a csh-variant for your login shell (why?), it would be:
env CPPFLAGS=-I/path/to/include LDFLAGS=-L/path/to/library ./configure

4. When it is compiling the file language-parser.tab.c, it gives me errors that say yytname undeclared.

You need to update your version of Bison. You can find the latest version at ftp://ftp.gnu.org/pub/gnu/bison/.

5. When I run make, it seems to run fine but then fails when it tries to link the final application complaining that it can't find some files.

Some old versions of make that don't correctly put the compiled versions of the files in the functions directory into that same directory. Try running cp *.o functions and then re-running make to see if that helps. If it does, you should really upgrade to a recent version of GNU make.

6. When linking PHP, it complains about a number of undefined references.

Take a look at the link line and make sure that all of the appropriate libraries are being included at the end. Common ones that you might have missed are '-ldl' and any libraries required for any database support you included.

If you're linking with Apache 1.2.x, did you remember to add the appropriate information to the EXTRA_LIBS line of the Configuration file and re-rerun Apache's Configure script? See the INSTALL file that comes with the distribution for more information.

Some people have also reported that they had to add '-ldl' immediately following libphp4.a when linking with Apache.

7. I can't figure out how to build PHP with Apache 1.3.

This is actually quite easy. Follow these steps carefully:

Grab the latest Apache 1.3 distribution from http://www.apache.org/dist/.
Ungzip and untar it somewhere, for example /usr/local/src/apache-1.3.
Compile PHP by first running ./configure --with-apache=/<path>/apache-1.3 (substitute <path> for the actual path to your apache-1.3 directory.
Type make followed by make install to build PHP and copy the necessary files to the Apache distribution tree.
Change directories into to your /<path>/apache-1.3/src directory and edit the Configuration file. Add to the file: AddModule modules/php4/libphp4.a.
Type: ./Configure followed by make.
You should now have a PHP-enabled httpd binary!

Note: You can also use the new Apache ./configure script. See the instructions in the README.configure file which is part of your Apache distribution. Also have a look at the INSTALL file in the PHP distribution.

8. I have followed all the steps to install the Apache module version on UNIX, and my PHP scripts show up in my browser or I am being asked to save the file.

This means that the PHP module is not getting invoked for some reason. Three things to check before asking for further help:

Make sure that the httpd binary you are running is the actual new httpd binary you just built. To do this, try running: /path/to/binary/httpd -l
If you don't see mod_php4.c listed then you are not running the right binary. Find and install the correct binary.
Make sure you have added the correct Mime Type to one of your Apache .conf files. It should be: AddType application/x-httpd-php3 .php3 (for PHP 3)
or AddType application/x-httpd-php .php (for PHP 4)
Also make sure that this AddType line is not hidden away inside a <Virtualhost> or <Directory> block which would prevent it from applying to the location of your test script.
Finally, the default location of the Apache configuration files changed between Apache 1.2 and Apache 1.3. You should check to make sure that the configuration file you are adding the AddType line to is actually being read. You can put an obvious syntax error into your httpd.conf file or some other obvious change that will tell you if the file is being read correctly.

9. It says to use: --activate-module=src/modules/php4/libphp4.a, but that file doesn't exist, so I changed it to --activate-module=src/modules/php4/libmodphp4.a and it doesn't work!? What's going on?

Note that the libphp4.a file is not supposed to exist. The apache process will create it!

10. When I try to build Apache with PHP as a static module using --activate-module=src/modules/php4/libphp4.a it tells me that my compiler is not ANSI compliant.

This is a misleading error message from Apache that has been fixed in more recent versions.

11. When I try to build PHP using --with-apxs I get strange error messages.

There are three things to check here. First, for some reason when Apache builds the apxs Perl script, it sometimes ends up getting built without the proper compiler and flags variables. Find your apxs script (try the command which apxs, it's sometimes found in /usr/local/apache/bin/apxs or /usr/sbin/apxs. Open it and check for lines similar to these:
my $CFG_CFLAGS_SHLIB = ' '; # substituted via Makefile.tmpl my $CFG_LD_SHLIB = ' '; # substituted via Makefile.tmpl my $CFG_LDFLAGS_SHLIB = ' '; # substituted via Makefile.tmpl
If this is what you see, you have found your problem. They may contain just spaces or other incorrect values, such as 'q()'. Change these lines to say:
my $CFG_CFLAGS_SHLIB = '-fpic -DSHARED_MODULE'; # substituted via Makefile.tmpl my $CFG_LD_SHLIB = 'gcc'; # substituted via Makefile.tmpl my $CFG_LDFLAGS_SHLIB = q(-shared); # substituted via Makefile.tmpl
The second possible problem should only be an issue on Red Hat 6.1 and 6.2. The apxs script Red Hat ships is broken. Look for this line:
my $CFG_LIBEXECDIR = 'modules'; # substituted via APACI install
If you see the above line, change it to this:
my $CFG_LIBEXECDIR = '/usr/lib/apache'; # substituted via APACI install
Last, if you reconfigure/reinstall Apache, add a make clean to the process after ./configure and before make.

12. During make, I get errors in microtime, and a lot of RUSAGE_ stuff.

During the make portion of installation, if you encounter problems that look similar to this:
microtime.c: In function `php_if_getrusage': microtime.c:94: storage size of `usg' isn't known microtime.c:97: `RUSAGE_SELF' undeclared (first use in this function) microtime.c:97: (Each undeclared identifier is reported only once microtime.c:97: for each function it appears in.) microtime.c:103: `RUSAGE_CHILDREN' undeclared (first use in this function) make[3]: *** [microtime.lo] Error 1 make[3]: Leaving directory `/home/master/php-4.0.1/ext/standard' make[2]: *** [all-recursive] Error 1 make[2]: Leaving directory `/home/master/php-4.0.1/ext/standard' make[1]: *** [all-recursive] Error 1 make[1]: Leaving directory `/home/master/php-4.0.1/ext' make: *** [all-recursive] Error 1

Your system is broken. You need to fix your /usr/include files by installing a glibc-devel package that matches your glibc. This has absolutely nothing to do with PHP. To prove this to yourself, try this simple test:
$ cat >test.c <<X #include <sys/resource.h> X $ gcc -E test.c >/dev/null
If that spews out errors, you know your include files are messed up.

13. I want to upgrade my PHP. Where can I find the ./configure line that was used to build my current PHP installation?

Either you look at config.nice file, in the source tree of your current PHP installation or, if this is not available, you simply run a
<?php phpinfo(); ?>
script. On top of the output the ./configure line, that was used to build this PHP installation is shown.

14. When building PHP with the GD library it either gives strange compile errors or segfaults on execution.

Make sure your GD library and PHP are linked against the same depending libraries (e.g. libpng).

Chapter 50. Using PHP

This section gathers most common errors you can face, while writing PHP scripts.

1. I would like to write a generic PHP script that can handle data coming from any form. How do I know which POST method variables are available?
2. I need to convert all single-quotes (') to a backslash followed by a single-quote. How can I do this with a regular expression?
3. When I do the following, the output is printed in the wrong order: function myfunc($argument) { echo $argument + 10; } $variable = 10; echo "myfunc($variable) = " . myfunc($variable); what's going on?
4. Hey, what happened to my newlines? <pre> <?php echo "This should be the first line."; ?> <?php echo "This should show up after the new line above."; ?> </pre>
5. I get the message 'Warning: Cannot send session cookie - headers already sent...' or 'Cannot add header information - headers already sent...'.
6. I need to access information in the request header directly. How can I do this?
7. When I try to use authentication with IIS I get 'No Input file specified'.
8. My PHP script works on IE and Lynx, but on Netscape some of my output is missing. When I do a "View Source" I see the content in IE but not in Netscape.
9. How am I supposed to mix XML and PHP? It complains about my <?xml> tags!
10. How can I use PHP with FrontPage or some other HTML editor that insists on moving my code around?
11. Where can I find a complete list of pre-set variables available to me, and why are these not documented in the PHP documentation?
12. I'm trying to access one of the standard CGI variables (such as $DOCUMENT_ROOT or $HTTP_REFERER) in a user-defined function, and it can't seem to find it. What's wrong?

1. I would like to write a generic PHP script that can handle data coming from any form. How do I know which POST method variables are available?

Make sure that the track_vars feature is enabled in your php.ini file. Since PHP 4.0.3, this feature is always on. When track_vars is on, it creates some associative arrays, the most important here is: $_POST (this used to be called $HTTP_POST_VARS in PHP versions prior 4.1.0). So, to write a generic script to handle POST method variables you would need something similar to the following:
foreach ($_POST as $var => $value) { echo "$var = $value<br>\n"; }

2. I need to convert all single-quotes (') to a backslash followed by a single-quote. How can I do this with a regular expression?

First off, take a look at the addslashes() function. It will do exactly what you want. You should also have a look at the magic_quotes_gpc directive in your php.ini file.

3. When I do the following, the output is printed in the wrong order:
function myfunc($argument) { echo $argument + 10; } $variable = 10; echo "myfunc($variable) = " . myfunc($variable);
what's going on?

To be able to use the results of your function in an expression (such as concatenating it with other strings in the example above), you need to return the value, not echo() it.

4. Hey, what happened to my newlines?
<pre> <?php echo "This should be the first line."; ?> <?php echo "This should show up after the new line above."; ?> </pre>

In PHP, the ending for a block of code is either "?>" or "?>\n" (where \n means a newline). So in the example above, the echoed sentences will be on one line, because PHP omits the newlines after the block ending. This means that you need to insert an extra newline after each block of PHP code to make it print out one newline.

Why does PHP do this? Because when formatting normal HTML, this usually makes your life easier because you don't want that newline, but you'd have to create extremely long lines or otherwise make the raw page source unreadable to achieve that effect.

5. I get the message 'Warning: Cannot send session cookie - headers already sent...' or 'Cannot add header information - headers already sent...'.

The functions header(), setcookie() and the session functions need to add headers to the output stream. But headers can only be sent before all other content, check if your script is sending headers after having already sent content.

6. I need to access information in the request header directly. How can I do this?

The getallheaders() function will do this if you are running PHP as an Apache module. So, the following bit of code will show you all the request headers:
$headers = getallheaders(); foreach ($headers as $name => $content) { echo "headers[$name] = $content<br>\n"; }

7. When I try to use authentication with IIS I get 'No Input file specified'.

The security model of IIS is at fault here. This is a problem common to all CGI programs running under IIS. A workaround is to create a plain HTML file (not parsed by PHP) as the entry page into an authenticated directory. Then use a META tag to redirect to the PHP page, or have a link to the PHP page. PHP will then recognize the authentication correctly. With the ISAPI module, this is not a problem. This should not effect other NT web servers. For more information, see: http://support.microsoft.com/support/kb/articles/q160/4/22.asp.

8. My PHP script works on IE and Lynx, but on Netscape some of my output is missing. When I do a "View Source" I see the content in IE but not in Netscape.

Netscape is more strict regarding html tags (such as tables) then IE. Running your html output through a html validator, such as validator.w3.org, might be helpful. For example, a missing </table> might cause this.

Also, both IE and Lynx ignore any NULs (\0) in the HTML stream, Netscape does not. The best way to check for this is to compile the command line version of PHP (also known as the CGI version) and run your script from the command line. In *nix, pipe it through od -c and look for any \0 characters. If you are on Windows you need to find an editor or some other program that lets you look at binary files. When Netscape sees a NUL in a file it will typically not output anything else on that line whereas both IE and Lynx will.

9. How am I supposed to mix XML and PHP? It complains about my <?xml> tags!

You need to turn off the short tags by setting short_tags to 0 in your php.ini file, or by using the appropriate Apache directive. You could even use a <File> section to do this selectively.

10. How can I use PHP with FrontPage or some other HTML editor that insists on moving my code around?

One of the easiest things to do is to enable using ASP tags in your PHP code. This allows you to use the ASP-style <% and %> code delimiters. Some of the popular HTML editors handle those more intelligently (for now). To enable the ASP-style tags, you need to set the asp_tags php.ini variable, or use the appropriate Apache directive.

11. Where can I find a complete list of pre-set variables available to me, and why are these not documented in the PHP documentation?

The best way is to stick a <?php phpinfo(); ?> part on a page and load it up. This will show you all sorts of information about your PHP setup, including a list of both environment variables and also special variables set by your web server. This list can't really be documented in the PHP documentation because it will change from one server to another.

12. I'm trying to access one of the standard CGI variables (such as $DOCUMENT_ROOT or $HTTP_REFERER) in a user-defined function, and it can't seem to find it. What's wrong?

Environment variables are normal global variables, so you must either declare them as global variables in your function (by using "global $DOCUMENT_ROOT;", for example) or by using the global variable array (ie, "$GLOBALS["DOCUMENT_ROOT"]".

Chapter 51. PHP and HTML

PHP and HTML interact a lot: PHP can generate HTML, and HTML can pass information to PHP.

1. What encoding/decoding do I need when I pass a value through a form/URL?
2. I'm trying to use an <input type="image"> tag, but the $foo.x and $foo.y variables aren't available. Where are they?
3. How do I create arrays in a HTML <form>?
4. How do I get all the results from a select multiple HTML tag?

1. What encoding/decoding do I need when I pass a value through a form/URL?

There are several stages for which encoding is important. Assuming that you have a string $data, which contains the string you want to pass on in a non-encoded way, these are the relevant stages:

HTML interpretation. In order to specify a random string, you must include it in double quotes, and htmlspecialchars the whole value.
URL: A URL consists of several parts. If you want your data to be interpreted as one item, you must encode it with urlencode().

Example 51-1. A hidden HTML form element
<?php echo "<input type=hidden value=\"" . htmlspecialchars($data) . "\">\n"; ?>

Note: It is wrong to urlencode() $data, because it's the browsers responsibility to urlencode() the data. All popular browsers do that correctly. Note that this will happen regardless of the method (i.e., GET or POST). You'll only notice this in case of GET request though, because POST requests are usually hidden.

Example 51-2. Data to be edited by the user

<?php
    echo "<textarea name=mydata>\n";
    echo htmlspecialchars($data)."\n";
    echo "</textarea>";
?>

Note: The data is shown in the browser as intended, because the browser will interpret the HTML escaped symbols.
Upon submitting, either via GET or POST, the data will be urlencoded by the browser for transferring, and directly urldecoded by PHP. So in the end, you don't need to do any urlencoding/urldecoding yourself, everything is handled automagically.

Example 51-3. In an URL

<?php
    echo "<a href=\"" . htmlspecialchars("/nextpage.php?stage=23&data=" .
        urlencode($data)) . "\">\n";
?>

Note: In fact you are faking a HTML GET request, therefore it's necessary to manually urlencode() the data.

Note: You need to htmlspecialchars() the whole URL, because the URL occurs as value of an HTML-attribute. In this case, the browser will first un-htmlspecialchars() the value, and then pass the URL on. PHP will understand the URL correctly, because you urlencoded() the data.
You'll notice that the & in the URL is replaced by &. Although most browsers will recover if you forget this, this isn't always possible. So even if your URL is not dynamic, you need to htmlspecialchars() the URL.

2. I'm trying to use an <input type="image"> tag, but the $foo.x and $foo.y variables aren't available. Where are they?

When submitting a form, it is possible to use an image instead of the standard submit button with a tag like:
<input type="image" src="image.gif" name="foo">
When the user clicks somewhere on the image, the accompanying form will be transmitted to the server with two additional variables: foo.x and foo.y.

Because $foo.x and $foo.y are invalid variable names in PHP, they are automagically converted to $foo_x and $foo_y. That is, the periods are replaced with underscores.

3. How do I create arrays in a HTML <form>?

To get your <form> result sent as an array to your PHP script you name the <input>, <select> or <textarea> elements like this:
<input name="MyArray[]"> <input name="MyArray[]"> <input name="MyArray[]"> <input name="MyArray[]">
Notice the square brackets after the variable name, that's what makes it an array. You can group the elements into different arrays by assigning the same name to different elements:
<input name="MyArray[]"> <input name="MyArray[]"> <input name="MyOtherArray[]"> <input name="MyOtherArray[]">
This produces two arrays, MyArray and MyOtherArray, that gets sent to the PHP script. It's also possible to assign specific keys to your arrays:
<input name="AnotherArray[]"> <input name="AnotherArray[]"> <input name="AnotherArray[email]"> <input name="AnotherArray[phone]">
The AnotherArray array will now contain the keys 0, 1, email and phone.

Note: Specifying an arrays key is optional in HTML. If you do not specify the keys, the array gets filled in the order the elements appear in the form. Our first example will contain keys 0, 1, 2 and 3.

4. How do I get all the results from a select multiple HTML tag?

The select multiple tag in an HTML construct allows users to select multiple items from a list. These items are then passed to the action handler for the form. The problem is that they are all passed with the same widget name. ie.
<select name="var" multiple>
Each selected option will arrive at the action handler as:
var=option1 var=option2 var=option3
Each option will overwrite the contents of the previous $var variable. The solution is to use PHP's "array from form element" feature. The following should be used:
<select name="var[]" multiple>
This tells PHP to treat $var as an array and each assignment of a value to var[] adds an item to the array. The first item becomes $var[0], the next $var[1], etc. The count() function can be used to determine how many options were selected, and the sort() function can be used to sort the option array if necessary.

Note that if you are using JavaScript the [] on the element name might cause you problems when you try to refer to the element by name. Use it's numerical form element ID instead, or enclose the variable name in single quotes and use that as the index to the elements array, for example:
variable = documents.forms[0].elements['var[]'];

Chapter 52. PHP and COM

PHP can be used to access COM and DCOM objects on Win32 platforms.

1. I have built a DLL to calculate something. Is there any way to run this DLL under PHP ?
2. What does 'Unsupported variant type: xxxx (0xxxxx)' mean ?
3. Is it possible manipulate visual objects in PHP ?
4. Can I store a COM object in a session ?
5. How can I trap COM errors ?
6. Can I generate DLL files from PHP scripts like i can in Perl ?
7. What does 'Unable to obtain IDispatch interface for CLSID {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}' mean ?
8. How can I run COM object from remote server ?
9. I get 'DCOM is disabled in C:\path...\scriptname.php on line 6', what can I do ?
10. Is it possible to load/manipulate an ActiveX object in a page with PHP ?
11. Is it possible to get a running instance of a component ?
12. Is there a way to handle an event sent from COM object ?
13. I'm having problems when trying to invoke a method of a COM object which exposes more than one interface. What can I do ?
14. So PHP works with COM, how about COM+ ?
15. If PHP can manipulate COM objects, can we imagine to use MTS to manage components resources, in conjunction with PHP ?

1. I have built a DLL to calculate something. Is there any way to run this DLL under PHP ?

If this is a simple DLL there is no way yet to run it from PHP. If the DLL contains a COM server you may be able to access it if it implements the IDispatch interface.

2. What does 'Unsupported variant type: xxxx (0xxxxx)' mean ?

There are dozens of VARIANT types and combinations of them. Most of them are already supported but a few still have to be implemented. Arrays are not completely supported. Only single dimensional indexed only arrays can be passed between PHP and COM. If you find other types that aren't supported, please report them as a bug (if not already reported) and provide as much information as available.

3. Is it possible manipulate visual objects in PHP ?

Generally it is, but as PHP is mostly used as a web scripting language it runs in the web servers context, thus visual objects will never appear on the servers desktop. If you use PHP for application scripting e.g. in conjunction with PHP-GTK there is no limitation in accessing and manipulating visual objects through COM.

4. Can I store a COM object in a session ?

No, you can't. COM instances are treated as resources and therefore they are only available in a single script's context.

5. How can I trap COM errors ?

Currently it's not possible to trap COM errors beside the ways provided by PHP itself (@, track_errors, ..), but we are thinking of a way to implement this.

6. Can I generate DLL files from PHP scripts like i can in Perl ?

No, unfortunately there is no such tool available for PHP.

7. What does 'Unable to obtain IDispatch interface for CLSID {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}' mean ?

This error can have multiple reasons:

the CLSID is wrong
the requested DLL is missing
the requested component doesn't implement the IDispatch interface

8. How can I run COM object from remote server ?

Exactly like you run local objects. You only have to pass the IP of the remote machine as second parameter to the COM constructor.

Make sure that you have set com.allow_dcom=true in your php.ini.

9. I get 'DCOM is disabled in C:\path...\scriptname.php on line 6', what can I do ?

Edit your php.ini and set com.allow_dcom=true.

10. Is it possible to load/manipulate an ActiveX object in a page with PHP ?

This has nothing to do with PHP. ActiveX objects are loaded on client side if they are requested by the HTML document. There is no relation to the PHP script and therefore there is no direct server side interaction possible.

11. Is it possible to get a running instance of a component ?

This is possible with the help of monikers. If you want to get multiple references to the same word instance you can create that instance like shown:

$word = new COM("C:\docs\word.doc");

This will create a new instance if there is no running instance available or it will return a handle to the running instance, if available.

12. Is there a way to handle an event sent from COM object ?

Not yet.

13. I'm having problems when trying to invoke a method of a COM object which exposes more than one interface. What can I do ?

The answer is as simple as unsatisfying. I don't know exactly but i think you can do nothing. If someone has specific information about this, please let me know :)

14. So PHP works with COM, how about COM+ ?

COM+ extends COM by a framework for managing components through MTS and MSMQ but there is nothing special that PHP has to support to use such components.

15. If PHP can manipulate COM objects, can we imagine to use MTS to manage components resources, in conjunction with PHP ?

PHP itself doesn't handle transactions yet. Thus if an error occurs no rollback is initiated. If you use components that support transactions you will have to implement the transaction management yourself.

Chapter 53. PHP and other languages

PHP is the best language for web programing, but what about other languages?

1. PHP vs. ASP?
2. Is there an ASP to PHP converter?
3. PHP vs. Cold Fusion?
4. PHP vs. Perl?

1. PHP vs. ASP?

ASP is not really a language in itself, it's an acronym for Active Server Pages, the actual language used to program ASP with is Visual Basic Script or JScript. The biggest drawback of ASP is that it's a proprietary system that is natively used only on Microsoft Internet Information Server (IIS). This limits it's availability to Win32 based servers. There are a couple of projects in the works that allows ASP to run in other environments and webservers: InstantASP from Halcyon (commercial), Chili!Soft ASP from Chili!Soft (commercial) and OpenASP from ActiveScripting.org (free). ASP is said to be a slower and more cumbersome language than PHP, less stable as well. Some of the pros of ASP is that since it primarily uses VBScript it's relatively easy to pick up the language if you're already know how to program in Visual Basic. ASP support is also enabled by default in the IIS server making it easy to get up and running. The components built in ASP are really limited, so if you need to use "advanced" features like interacting with FTP servers, you need to buy additional components.

2. Is there an ASP to PHP converter?

Yes, asp2php is the one most often referred to.

3. PHP vs. Cold Fusion?

PHP is commonly said to be faster and more efficient for complex programming tasks and trying out new ideas. PHP is generally referred to as more stable and less resource intensive as well. Cold Fusion has better error handling, database abstraction and date parsing although database abstraction is addressed in PHP 4. Another thing that is listed as one of Cold Fusion's strengths is its excellent search engine, but it has been mentioned that a search engine is not something that should be included in a web scripting language. PHP runs on almost every platform there is; Cold Fusion is only available on Win32, Solaris, Linux and HP/UX. Cold Fusion has a good IDE and is generally easier to get started with, whereas PHP initially requires more programming knowledge. Cold Fusion is designed with non-programmers in mind, while PHP is focused on programmers.

A great summary by Michael J Sheldon on this topic has been posted to the PHP mailing list. A copy can be found here.

4. PHP vs. Perl?

The biggest advantage of PHP over Perl is that PHP was designed for scripting for the web where Perl was designed to do a lot more and can because of this get very complicated. The flexibility / complexity of Perl makes it easier to write code that another author / coder has a hard time reading. PHP has a less confusing and stricter format without losing flexibility. PHP is easier to integrate into existing HTML than Perl. PHP has pretty much all the 'good' functionality of Perl: constructs, syntax and so on, without making it as complicated as Perl can be. Perl is a very tried and true language, it's been around since the late eighties, but PHP is maturing very quickly.

Chapter 54. Migrating from PHP 2 to PHP 3

PHP has already a long history behind him: Legendary PHP 1.0, PHP/FI, PHP 3.0 and PHP 4.0.

1. Migrating from PHP 2 to PHP 3?

1. Migrating from PHP 2 to PHP 3?

PHP/FI 2.0 is no longer supported. Please see appropriate manual section for information about migration from PHP/FI 2.0.

If you are still working with PHP 2, we strongly recommend you to upgrade straight to PHP 4.

Chapter 55. Migrating from PHP 3 to PHP 4

PHP has already a long history behind him : Legendary PHP 1.0, PHP/FI, PHP 3.0 and PHP 4.0.

1. Migrating from PHP3 to PHP4
2. Incompatible functions?

1. Migrating from PHP3 to PHP4

PHP 4 was designed to be as compatible with earlier versions of PHP as possible and very little functionality was broken in the process. If you're really unsure about compatibility you should install PHP 4 in a test environment and run your scripts there.

Also see the appropriate migration appendix of this manual.

2. Incompatible functions?

Since PHP 4 is basically a rewrite of the entire PHP engine there was very few functions that were altered and only then some of the more exotic ones.

Chapter 56. Miscellaneous Questions

There can be some questions we can't put into other categories. Here you can find them.

1. Where did the pop-ups go on the website? Can I have the code for that?
2. How can I handle the bz2 compressed manuals on Windows?

1. Where did the pop-ups go on the website? Can I have the code for that?

The yellow pop-up windows on the old site were pretty cool, but were very difficult to maintain (since some companies seem to enjoy changing the way their browsers work with every new release).

All the code for previous versions of the website is still available through CVS. Specifically, the last version of shared.inc (that had all the Javascript and DHTML to do the popups) is available here.

2. How can I handle the bz2 compressed manuals on Windows?

If you don't have an archiver-tool to handle bz2 files download the commandline tool from Redhat (please find further information below).

If you would not like to use a command line tool, you can try free tools like Stuffit Expander, UltimateZip, 7-Zip, or Quick Zip. If you have tools like WinRAR or Power Archiver, you can easily decompress the bz2 files with it. If you use Windows Commander, a bz2 plugin for that program is available freely from the Windows Commander site.

The bzip2 commandline tool from Redhat:

Win2k Sp2 users grab the latest version 1.0.2, all other Windows user should grab version 1.00. After downloading rename the executable to bzip2.exe. For convenience put it into a directory in your path, e.g. C:\Windows where C represents your windows installation drive.

Note: lang stands for your language and x for the desired format, e.g.: pdf. To uncompress the php_manual_lang.x.bz2 follow these simple instructions:

open a command prompt window
cd to the folder where you stored the downloaded php_manual_lang.x.bz2
invoke bzip2 -d php_manual_lang.x.bz2, extracting php_manual_lang.x in the same folder

In case you downloaded the php_manual_lang.tar.bz2 with many html-files in it, the procedure is the same. The only difference is that you got a file php_manual_lang.tar. The tar format is known to be treated with most common archivers on Windows like e.g. WinZip.

VII. Appendixes

Table of Contents
A. History of PHP and related projects
B. Migrating from PHP 3 to PHP 4
C. Migrating from PHP/FI 2 to PHP 3
D. Debugging PHP
E. Extending PHP
F. List of Function Aliases
G. List of Reserved Words
H. List of Resource Types
I. List of Supported Protocols/Wrappers
J. List of Parser Tokens
K. About the manual
L. Missing Stuff

Appendix A. History of PHP and related projects

PHP has come a long way in the last few years. Growing to be one of the most prominent languages powering the Web was not an easy task. Those of you interested in briefly seeing how PHP grew out to what it is today, read on.

History of PHP

PHP/FI

PHP succeeds an older product, named PHP/FI. PHP/FI was created by Rasmus Lerdorf in 1995, initially as a simple set of Perl scripts for tracking accesses to his online resume. He named this set of scripts 'Personal Home Page Tools'. As more functionality was required, Rasmus wrote a much larger C implementation, which was able to communicate with databases, and enabled users to develop simple dynamic Web applications. Rasmus chose to release the source code for PHP/FI for everybody to see, so that anybody can use it, as well as fix bugs in it and improve the code.

PHP/FI, which stood for Personal Home Page / Forms Interpreter, included some of the basic functionality of PHP as we know it today. It had Perl-like variables, automatic interpretation of form variables and HTML embedded syntax. The syntax itself was similar to that of Perl, albeit much more limited, simple, and somewhat inconsistent.

By 1997, PHP/FI 2.0, the second write-up of the C implementation, had a cult of several thousand users around the world (estimated), with approximately 50,000 domains reporting as having it installed, accounting for about 1% of the domains on the Internet. While there were several people contributing bits of code to this project, it was still at large a one-man project.

PHP/FI 2.0 was officially released only in November 1997, after spending most of its life in beta releases. It was shortly afterwards succeeded by the first alphas of PHP 3.0.

PHP 3

PHP 3.0 was the first version that closely resembles PHP as we know it today. It was created by Andi Gutmans and Zeev Suraski in 1997 as a complete rewrite, after they found PHP/FI 2.0 severely underpowered for developing their own eCommerce application. In an effort to cooperate and start building upon PHP/FI's existing user-base, Andi, Rasmus and Zeev decided to cooperate and announce PHP 3.0 as the official successor of PHP/FI 2.0, and development of PHP/FI 2.0 was mostly halted.

One of the biggest strengths of PHP 3.0 was its strong extensibility features. In addition to providing end users with a solid infrastructure for lots of different databases, protocols and APIs, PHP 3.0's extensibility features attracted dozens of developers to join in and submit new extension modules. Arguably, this was the key to PHP 3.0's tremendous success. Other key features introduced in PHP 3.0 were the object oriented syntax support and the much more powerful and consistent language syntax.

The whole new language was released under a new name, that removed the implication of limited personal use that the PHP/FI 2.0 name held. It was named plain 'PHP', with the meaning being a recursive acronym - PHP: Hypertext Preprocessor.

By the end of 1998, PHP grew to an install base of tens of thousands of users (estimated) and hundreds of thousands of Web sites reporting it installed. At its peak, PHP 3.0 was installed on approximately 10% of the Web servers on the Internet.

PHP 3.0 was officially released in June 1998, after having spent about 9 months in public testing.

PHP 4

By the winter of 1998, shortly after PHP 3.0 was officially released, Andi Gutmans and Zeev Suraski had begun working on a rewrite of PHP's core. The design goals were to improve performance of complex applications, and improve the modularity of PHP's code base. Such applications were made possible by PHP 3.0's new features and support for a wide variety of third party databases and APIs, but PHP 3.0 was not designed to handle such complex applications efficiently.

The new engine, dubbed 'Zend Engine' (comprised of their first names, Zeev and Andi), met these design goals successfully, and was first introduced in mid 1999. PHP 4.0, based on this engine, and coupled with a wide range of additional new features, was officially released in May 2000, almost two years after its predecessor, PHP 3.0. In addition to the highly improved performance of this version, PHP 4.0 included other key features such as support for many more Web servers, HTTP sessions, output buffering, more secure ways of handling user input and several new language constructs.

PHP 4 is currently the latest released version of PHP. Work has already begun on modifying and improving the Zend Engine to integrate the features which were designed for PHP 5.0.

Today, PHP is being used by hundreds of thousands of developers (estimated), and several million sites report as having it installed, which accounts for over 20% of the domains on the Internet.

PHP's development team includes dozens of developers, as well as dozens others working on PHP-related projects such as PEAR and the documentation project.

History of PHP related projects

PEAR

PEAR, the PHP Extension and Application Repository (originally, PHP Extension and Add-on Repository) is PHP's version of foundation classes, and may grow in the future to be one of the key ways to distribute both PHP and C-based PHP extensions among developers.

PEAR was born in discussions held in the PHP Developers' Meeting (PDM) held in January 2000 in Tel Aviv. It was created by Stig S. Bakken, and is dedicated to his first-born daughter, Malin Bakken.

Since early 2000, PEAR has grown to be a big, significant project with a large number of developers working on implementing common, reusable functionality for the benefit of the entire PHP community. PEAR today includes a wide variety of infrastructure foundation classes for database access, content caching, mathematical calculations, eCommerce and much more.

PHP Quality Assurance Initiative

The PHP Quality Assurance Initiative was set up in the summer of 2000 in response to criticism that PHP releases were not being tested well enough for production environments. The team now consists of a core group of developers with a good understanding of the PHP code base. These developers spend a lot of their time localizing and fixing bugs within PHP. In addition there are many other team members who test and provide feedback on these fixes using a wide variety of platforms.

PHP-GTK

PHP-GTK is the PHP solution for writing client side GUI applications. Andrei Zmievski remembers the planing and creation process of PHP-GTK:

GUI programming has always been of my interests, and I found that Gtk+ is a very nice toolkit, except that programming with it in C is somewhat tedious. After witnessing PyGtk and GTK-Perl implementations, I decided to see if PHP could be made to interface with Gtk+, even minimally. Starting in August of 2000, I began to have a bit more free time so that is when I started experimenting. My main guideline was the PyGtk implementation as it was fairly feature complete and had a nice object-oriented interface. James Henstridge, the author of PyGtk, provided very helpful advice during those initial stages.
Hand-writing the interfaces to all the Gtk+ functions was out of the question, so I seized upon the idea of code-generator, similar to how PyGtk did it. The code generator is a PHP program that reads a set of .defs file containing the Gtk+ classes, constants, and methods information and generates C code that interfaces PHP with them. What cannot be generated automatically can be written by hand in .overrides file.
Working on the code generator and the infrastructure took some time, because I could spend little time on PHP-GTK during the fall of 2000. After I showed PHP-GTK to Frank Kromann, he got interested and started helping me out with code generator work and Win32 implementation. When we wrote the first Hello World program and fired it up, it was extremely exciting. It took a couple more months to get the project to a presentable condition and the initial version was released on March 1, 2001. The story promptly hit SlashDot.
Sensing that PHP-GTK might be extensive, I set up separate mailing lists and CVS repositories for it, as well as the gtk.php.net website with the help of Colin Viebrock. The documentation would also need to be done and James Moore came in to help with that.
Since its release PHP-GTK has been gaining popularity. We have our own documentation team, the manual keeps improving, people start writing extensions for PHP-GTK, and more and more exciting applications with it.

Books about PHP

As PHP grew, it began to be recognized as a world-wide popular development platform. One of the most interesting ways of seeing this trend was by observing the books about PHP that came out throughout the years.

To the best of our knowledge, the first book dedicated to PHP was 'PHP - tvorba interaktivních internetových aplikací' - a Czech book published in April 1999, authored by Jirka Kosek. Next month followed a German book authored by Egon Schmid, Christian Cartus and Richard Blume. The first book in English about PHP was published shortly afterwards, and was 'Core PHP Programming' by Leon Atkinson. Both of these books covered PHP 3.0.

While these books were the first of their kind - they were followed by a large number of books from a host of authors and publishers. There are over 40 books in English, 50 books in German, and over 20 books in French! In addition, you can find books about PHP in many other languages, including Spanish, Korean, Japanese and Hebrew.

Clearly, this large number of books, written by different authors, published by many publishers, and their availability in so many languages - are a strong testimony for PHP's world-wide success.

Publications about PHP

To the best of our knowledge, the first article about PHP in a hard-copy magazine was published in the Czech mutation of Computerworld in the spring of 1998, and covered PHP 3.0. As with books, this was the first in a series of many articles published about PHP in various prominent magazines.

Articles about PHP appeared in Dr. Dobbs, Linux Enterprise, Linux Magazine and many more. Articles about migrating ASP-based applications to PHP under Windows even appear on Microsoft's very own MSDN!

Appendix B. Migrating from PHP 3 to PHP 4

What has changed in PHP 4

PHP 4 and the integrated Zend engine have greatly improved PHP's performance and capabilities, but great care has been taken to break as little existing code as possible. So migrating your code from PHP 3 to 4 should be much easier than migrating from PHP/FI 2 to PHP 3. A lot of existing PHP 3 code should be ready to run without changes, but you should still know about the few differences and take care to test your code before switching versions in production environments. The following should give you some hints about what to look for.

Running PHP 3 and PHP 4 concurrently

Recent operating systems provide the ability to perform versioning and scoping. This features make it possible to let PHP 3 and PHP 4 run as concurrent modules in one Apache server.

This feature is known to work on the following platforms:

Linux with recent binutils (binutils 2.9.1.0.25 tested)
Solaris 2.5 or better
FreeBSD (3.2, 4.0 tested)

To enable it, configure PHP3 and PHP4 to use APXS (--with-apxs) and the necessary link extensions (--enable-versioning). Otherwise, all standard installations instructions apply. For example:

$ ./configure \
  --with-apxs=/apache/bin/apxs \
  --enable-versioning \
  --with-mysql \
  --enable-track-vars

Migrating Configuration Files

The global configuration file, php3.ini, has changed its name to php.ini.

For the Apache configuration file, there are slightly more changes. The MIME types recognized by the PHP module have changed.

application/x-httpd-php3        -->    application/x-httpd-php
application/x-httpd-php3-source -->    application/x-httpd-php-source

You can make your configuration files work with both versions of PHP (depending on which one is currently compiled into the server), using the following syntax:

AddType  application/x-httpd-php3        .php3
AddType  application/x-httpd-php3-source .php3s

AddType  application/x-httpd-php         .php
AddType  application/x-httpd-php-source  .phps

In addition, the PHP directive names for Apache have changed.

Starting with PHP 4.0, there are only four Apache directives that relate to PHP:

php_value [PHP directive name] [value]
php_flag [PHP directive name] [On|Off]
php_admin_value [PHP directive name] [value]
php_admin_flag [PHP directive name] [On|Off]

There are two differences between the Admin values and the non admin values:

Admin values (or flags) can only appear in the server-wide apache configuration files (e.g., httpd.conf).
Standard values (or flags) cannot control certain PHP directives, for example - safe mode (if you could override safe mode settings in .htaccess files, it would defeat safe-mode's purpose). In contrast, Admin values can modify the value of any PHP directive.

To make the transition process easier, PHP 4 is bundled with scripts that automatically convert your Apache configuration and .htaccess files to work with both PHP 3 and PHP 4. These scripts do NOT convert the mime type lines! You have to convert these yourself.

To convert your Apache configuration files, run the apconf-conv.sh script (available in the scripts/apache/ directory). For example:

~/php4/scripts/apache:#  ./apconf-conv.sh /usr/local/apache/conf/httpd.conf

Your original configuration file will be saved in httpd.conf.orig.

To convert your .htaccess files, run the aphtaccess-conv.sh script (available in the scripts/apache/ directory as well):

~/php4/scripts/apache:#  find / -name .htaccess -exec ./aphtaccess-conv.sh {} \;

Likewise, your old .htaccess files will be saved with an .orig prefix.

The conversion scripts require awk to be installed.

Parser behavior

Parsing and execution are now two completely separated steps, no execution of a files code will happen until the complete file and everything it requires has completely and successfully been parsed.

One of the new requirements introduced with this split is that required and included files now have to be syntactically complete. You can no longer spread the different controlling parts of a control structure across file boundaries. That is you cannot start a for or while loop, an if statement or a switch block in one file and have the end of loop, else, endif, case or break statements in a different file.

It still perfectly legal to include additional code within loops or other control structures, only the controlling keywords and corresponding curly braces {...} have to be within the same compile unit (file or eval()ed string).

This should not harm to much as spreading code like this should be considered as very bad style anyway.

Another thing no longer possible, though rarely seen in PHP 3 code is returning values from a required file. Returning a value from an included file is still possible.

Error reporting

Configuration changes

With PHP 3 the error reporting level was set as a simple numeric value formed by summing up the numbers related to different error levels. Usual values where 15 for reporting all errors and warnings or 7 for reporting everything but simple notice messages reporting bad style and things like that.

PHP 4 has a larger set of error and warning levels and comes with a configuration parser that now allows for symbolic constants to be used for setting the intended behavior.

Error reporting level should now be configured by explicitly taking away the warning levels you do not want to generate error messages by x-oring them from the symbolic constant E_ALL. Sounds complicated? Well, lets say you want the error reporting system to report all but the simple style warnings that are categorized by the symbolic constant E_NOTICE. Then you'll put the following into your php.ini: error_reporting = E_ALL & ~ ( E_NOTICE ). If you want to suppress warnings too you add up the appropriate constant within the braces using the binary or operator '|': error_reporting= E_ALL & ~ ( E_NOTICE | E_WARNING ).

Warning

When upgrading code or servers from PHP 3 to PHP 4 you should check these settings and calls to error_reporting() or you might disable reporting the new error types, especially E_COMPILE_ERROR. This may lead to empty documents without any feedback of what happened or where to look for the problem.

Warning

Using the old values 7 and 15 for setting up error reporting is a very bad idea as this suppresses some of the newly added error classes including parse errors. This may lead to very strange behavior as scripts might no longer work without error messages showing up anywhere.

This has lead to a lot of unreproducible bug reports in the past where people reported script engine problems they were not capable to track down while the TRUE case was usually some missing '}' in a required file that the parser was not able to report due to a misconfigured error reporting system.

So checking your error reporting setup should be the first thing to do whenever your scripts silently die. The Zend engine can be considered mature enough nowadays to not cause this kind of strange behavior.

Additional warning messages

A lot of existing PHP 3 code uses language constructs that should be considered as very bad style as this code, while doing the intended thing now, could easily be broken by changes in other places. PHP 4 will output a lot of notice messages in such situations where PHP 3 didn't. The easy fix is to just turn off E_NOTICE messages, but it is usually a good idea to fix the code instead.

The most common case that will now produce notice messages is the use of unquoted string constants as array indices. Both PHP 3 and 4 will fall back to interpret these as strings if no keyword or constant is known by that name, but whenever a constant by that name had been defined anywhere else in the code it might break your script. This can even become a security risk if some intruder manages to redefine string constants in a way that makes your script give him access rights he wasn't intended to have. So PHP 4 will now warn you whenever you use unquoted string constants as for example in $_SERVER[REQUEST_METHOD]. Changing it to $_SERVER['REQUEST_METHOD'] will make the parser happy and greatly improve the style and security of your code.

Another thing PHP 4 will now tell you about is the use of uninitialized variables or array elements.

Initializers

Static variable and class member initializers only accept scalar values while in PHP 3 they accepted any valid expression. This is, once again, due to the split between parsing and execution as no code has yet been executed when the parser sees the initializer.

For classes you should use constructors to initialize member variables instead. For static variables anything but a simple static value rarely makes sense anyway.

`empty("0")`

The perhaps most controversial change in behavior has happened to the behavior of the empty(). A String containing only the character '0' (zero) is now considered empty while it wasn't in PHP 3.

This new behavior makes sense in web applications, with all input fields returning strings even if numeric input is requested, and with PHP's capabilities of automatic type conversion. But on the other had it might break your code in a rather subtle way, leading to misbehavior that is hard to track down if you do not know about what to look for.

Missing functions

While PHP 4 comes with a lot of new features, functions and extensions, you may still find some functions from version 3 missing. A small number of core functions has vanished because they do not work with the new scheme of splitting parsing and execution as introduced into 4 with the Zend engine. Other functions and even complete extensions have become obsolete as newer functions and extensions serve the same task better and/or in a more general way. Some functions just simply haven't been ported yet and finally some functions or extensions may be missing due to license conflicts.

Functions missing due to conceptual changes

As PHP 4 now separates parsing from execution it is no longer possible to change the behavior of the parser (now embedded in the Zend engine) at runtime as parsing already happened by then. So the function short_tags() no longer exists. You can still change the parsers behavior by setting appropriate values in the php.ini file.

Another feature of PHP 3 that is not a part of PHP 4 is the bundled debugging interface. There are third-party add-ons for the Zend engine which add similar functionality.

Deprecate functions and extensions

The Adabas and Solid database extensions are no more. Long live the unified ODBC extension instead.

Changed status for unset()

unset(), although still available, is implemented as a language construct rather than a function.

This does not have any consequences on the behavior of unset(), but testing for "unset" using function_exists() will return FALSE as it would with other language constructs that look like functions such as echo().

Another more practical change is that it is no longer possible to call unset() indirectly, that is $func="unset"; $func($somevar) won't work anymore.

PHP 3 extension

Extensions written for PHP 3 will not work with PHP 4, neither as binaries nor at the source level. It is not difficult to port extensions to PHP 4 if you have access to the original source. A detailed description of the actual porting process is not part of this text.

Variable substitution in strings

PHP 4 adds a new mechanism to variable substitution in strings. You can now finally access object member variables and elements from multidimensional arrays within strings.

To do so you have to enclose your variables with curly braces with the dollar sign immediately following the opening brace: {$...}

To embed the value of an object member variable into a string you simply write "text {$obj->member} text" while in PHP 3 you had to use something like "text ".$obj->member." text".

This should lead to more readable code, while it may break existing scripts written for PHP 3. But you can easily check for this kind of problem by checking for the character combination {$ in your code and by replacing it with \{$ with your favorite search-and-replace tool.

Cookies

PHP 3 had the bad habit of setting cookies in the reverse order of the setcookie() calls in your code. PHP 4 breaks with this habit and creates the cookie header lines in exactly the same order as you set the cookies in the code.

This might break some existing code, but the old behaviour was so strange to understand that it deserved a change to prevent further problems in the future.

Handling of global variables

While handling of global variables had the focus on to be easy in PHP 3 and early versions of PHP 4, the focus has changed to be more secure. While in PHP 3 the following example worked fine, in PHP 4 it has to be unset($GLOBALS["id"]);. This is only one issue of global variable handling. You should always have used $GLOBALS, with newer versions of PHP 4 you are forced to do so in most cases. Read more on this subject in the global references section.

Example B-1. Migration of global variables

<?php
$id = 1;
function test()
{
    global $id;
    unset($id);
}
test();
echo($id); // This will print out 1 in PHP 4
?>

Appendix C. Migrating from PHP/FI 2 to PHP 3

About the incompatibilities in 3.0

PHP 3.0 is rewritten from the ground up. It has a proper parser that is much more robust and consistent than 2.0's. 3.0 is also significantly faster, and uses less memory. However, some of these improvements have not been possible without compatibility changes, both in syntax and functionality.

In addition, PHP's developers have tried to clean up both PHP's syntax and semantics in version 3.0, and this has also caused some incompatibilities. In the long run, we believe that these changes are for the better.

This chapter will try to guide you through the incompatibilities you might run into when going from PHP/FI 2.0 to PHP 3.0 and help you resolve them. New features are not mentioned here unless necessary.

A conversion program that can automatically convert your old PHP/FI 2.0 scripts exists. It can be found in the convertor subdirectory of the PHP 3.0 distribution. This program only catches the syntax changes though, so you should read this chapter carefully anyway.

Start/end tags

The first thing you probably will notice is that PHP's start and end tags have changed. The old <? > form has been replaced by three new possible forms:
Example C-1. Migration: old start/end tags
<? echo "This is PHP/FI 2.0 code.\n"; ?>
As of version 2.0, PHP/FI also supports this variation:
Example C-2. Migration: first new start/end tags
<? echo "This is PHP 3.0 code!\n"; ?>
Notice that the end tag now consists of a question mark and a greater-than character instead of just greater-than. However, if you plan on using XML on your server, you will get problems with the first new variant, because PHP may try to execute the XML markup in XML documents as PHP code. Because of this, the following variation was introduced:
Example C-3. Migration: second new start/end tags
<?php echo "This is PHP 3.0 code!\n"; ?>
Some people have had problems with editors that don't understand the processing instruction tags at all. Microsoft FrontPage is one such editor, and as a workaround for these, the following variation was introduced as well:
Example C-4. Migration: third new start/end tags
<script language="php"> echo "This is PHP 3.0 code!\n"; </script>

if..endif syntax

The `alternative' way to write if/elseif/else statements, using if(); elseif(); else; endif; cannot be efficiently implemented without adding a large amount of complexity to the 3.0 parser. Because of this, the syntax has been changed:
Example C-5. Migration: old if..endif syntax
if ($foo); echo "yep\n"; elseif ($bar); echo "almost\n"; else; echo "nope\n"; endif;

Example C-6. Migration: new if..endif syntax
if ($foo): echo "yep\n"; elseif ($bar): echo "almost\n"; else: echo "nope\n"; endif;
Notice that the semicolons have been replaced by colons in all statements but the one terminating the expression (endif).

while syntax

Just like with if..endif, the syntax of while..endwhile has changed as well:
Example C-7. Migration: old while..endwhile syntax
while ($more_to_come); ... endwhile;

Example C-8. Migration: new while..endwhile syntax
while ($more_to_come): ... endwhile;

Warning

If you use the old while..endwhile syntax in PHP 3.0, you will get a never-ending loop.

Expression types

PHP/FI 2.0 used the left side of expressions to determine what type the result should be. PHP 3.0 takes both sides into account when determining result types, and this may cause 2.0 scripts to behave unexpectedly in 3.0.

Consider this example:

$a[0]=5;
$a[1]=7;

$key = key($a);
while ("" != $key) {
    echo "$keyn";
    next($a);
}

In PHP/FI 2.0, this would display both of $a's indices. In PHP 3.0, it wouldn't display anything. The reason is that in PHP 2.0, because the left argument's type was string, a string comparison was made, and indeed "" does not equal "0", and the loop went through. In PHP 3.0, when a string is compared with an integer, an integer comparison is made (the string is converted to an integer). This results in comparing atoi("") which is 0, and variablelist which is also 0, and since 0==0, the loop doesn't go through even once.

The fix for this is simple. Replace the while statement with:

while ((string)$key != "") {

Error messages have changed

PHP 3.0's error messages are usually more accurate than 2.0's were, but you no longer get to see the code fragment causing the error. You will be supplied with a file name and a line number for the error, though.

Short-circuited boolean evaluation

In PHP 3.0 boolean evaluation is short-circuited. This means that in an expression like (1 || test_me()), the function test_me() would not be executed since nothing can change the result of the expression after the 1.

This is a minor compatibility issue, but may cause unexpected side-effects.

Function `TRUE`/`FALSE` return values

Most internal functions have been rewritten so they return TRUE when successful and FALSE when failing, as opposed to 0 and -1 in PHP/FI 2.0, respectively. The new behaviour allows for more logical code, like $fp = fopen("/your/file") or fail("darn!");. Because PHP/FI 2.0 had no clear rules for what functions should return when they failed, most such scripts will probably have to be checked manually after using the 2.0 to 3.0 convertor.

Example C-9. Migration from 2.0: return values, old code
$fp = fopen($file, "r"); if ($fp == -1); echo("Could not open $file for reading<br>\n"); endif;

Example C-10. Migration from 2.0: return values, new code
$fp = @fopen($file, "r") or print("Could not open $file for reading<br>\n");

Other incompatibilities

The PHP 3.0 Apache module no longer supports Apache versions prior to 1.2. Apache 1.2 or later is required.
echo() no longer supports a format string. Use the printf() function instead.
In PHP/FI 2.0, an implementation side-effect caused $foo[0] to have the same effect as $foo. This is not true for PHP 3.0.
Reading arrays with $array[] is no longer supported
That is, you cannot traverse an array by having a loop that does $data = $array[]. Use current() and next() instead.
Also, $array1[] = $array2 does not append the values of $array2 to $array1, but appends $array2 as the last entry of $array1. See also multidimensional array support.
"+" is no longer overloaded as a concatenation operator for strings, instead it converts it's arguments to numbers and performs numeric addition. Use "." instead.

Example C-11. Migration from 2.0: concatenation for strings

echo "1" + "1";

In PHP 2.0 this would echo 11, in PHP 3.0 it would echo 2. Instead use:
echo "1"."1";

$a = 1; $b = 1; echo $a + $b;

This would echo 2 in both PHP 2.0 and 3.0.
$a = 1; $b = 1; echo $a.$b;
This will echo 11 in PHP 3.0.

Appendix D. Debugging PHP

About the debugger

PHP 3 includes support for a network-based debugger.

PHP 4 does not have an internal debugging facility. You can use one of the external debuggers though. The Zend IDE includes a debugger, and there are also some free debugger extensions like DBG at http://dd.cron.ru/dbg/ or the Advanced PHP Debugger (APD).

Using the Debugger

The internal debugger in PHP 3 is useful for tracking down evasive bugs. The debugger works by connecting to a TCP port for every time PHP 3 starts up. All error messages from that request will be sent to this TCP connection. This information is intended for "debugging server" that can run inside an IDE or programmable editor (such as Emacs).

How to set up the debugger:

Set up a TCP port for the debugger in the configuration file (debugger.port) and enable it (debugger.enabled).
Set up a TCP listener on that port somewhere (for example socket -l -s 1400 on UNIX).
In your code, run "debugger_on(host)", where host is the IP number or name of the host running the TCP listener.

Now, all warnings, notices etc. will show up on that listener socket, even if you turned them off with error_reporting().

Debugger Protocol

The PHP 3 debugger protocol is line-based. Each line has a type, and several lines compose a message. Each message starts with a line of the type start and terminates with a line of the type end. PHP 3 may send lines for different messages simultaneously.

A line has this format:

date time
host(pid)
type:
message-data

date

Date in ISO 8601 format (yyyy-mm-dd)

time

Time including microseconds: hh:mm:uuuuuu

host

DNS name or IP address of the host where the script error was generated.

pid

PID (process id) on host of the process with the PHP 3 script that generated this error.

type

Type of line. Tells the receiving program about what it should treat the following data as:

Table D-1. Debugger Line Types

Name	Meaning
`start`	Tells the receiving program that a debugger message starts here. The contents of `data` will be the type of error message, listed below.
`message`	The PHP 3 error message.
`location`	File name and line number where the error occurred. The first `location` line will always contain the top-level location. `data` will contain `file:line`. There will always be a `location` line after `message` and after every `function`.
`frames`	Number of frames in the following stack dump. If there are four frames, expect information about four levels of called functions. If no "frames" line is given, the depth should be assumed to be 0 (the error occurred at top-level).
`function`	Name of function where the error occurred. Will be repeated once for every level in the function call stack.
`end`	Tells the receiving program that a debugger message ends here.

data

Line data.

Table D-2. Debugger Error Types

Debugger	PHP 3 Internal
warning	E_WARNING
error	E_ERROR
parse	E_PARSE
notice	E_NOTICE
core-error	E_CORE_ERROR
core-warning	E_CORE_WARNING
unknown	(any other)

Example D-1. Example Debugger Message

1998-04-05 23:27:400966 lucifer.guardian.no(20481) start: notice
1998-04-05 23:27:400966 lucifer.guardian.no(20481) message: Uninitialized variable
1998-04-05 23:27:400966 lucifer.guardian.no(20481) location: (NULL):7
1998-04-05 23:27:400966 lucifer.guardian.no(20481) frames: 1
1998-04-05 23:27:400966 lucifer.guardian.no(20481) function: display
1998-04-05 23:27:400966 lucifer.guardian.no(20481) location: /home/ssb/public_html/test.php3:10
1998-04-05 23:27:400966 lucifer.guardian.no(20481) end: notice

Appendix E. Extending PHP

Adding functions to PHP

Function Prototype

All functions look like this:
void php3_foo(INTERNAL_FUNCTION_PARAMETERS) { }
Even if your function doesn't take any arguments, this is how it is called.

Function Arguments

Arguments are always of type pval. This type contains a union which has the actual type of the argument. So, if your function takes two arguments, you would do something like the following at the top of your function:

Example E-1. Fetching function arguments
pval *arg1, *arg2; if (ARG_COUNT(ht) != 2 || getParameters(ht,2,&arg1,&arg2)==FAILURE) { WRONG_PARAM_COUNT; }
NOTE: Arguments can be passed either by value or by reference. In both cases you will need to pass &(pval *) to getParameters. If you want to check if the n'th parameter was sent to you by reference or not, you can use the function, ParameterPassedByReference(ht,n). It will return either 1 or 0.

When you change any of the passed parameters, whether they are sent by reference or by value, you can either start over with the parameter by calling pval_destructor on it, or if it's an ARRAY you want to add to, you can use functions similar to the ones in internal_functions.h which manipulate return_value as an ARRAY.

Also if you change a parameter to IS_STRING make sure you first assign the new estrdup()'ed string and the string length, and only later change the type to IS_STRING. If you change the string of a parameter which already IS_STRING or IS_ARRAY you should run pval_destructor on it first.

Variable Function Arguments

A function can take a variable number of arguments. If your function can take either 2 or 3 arguments, use the following:

Example E-2. Variable function arguments
pval *arg1, *arg2, *arg3; int arg_count = ARG_COUNT(ht); if (arg_count < 2 || arg_count > 3 || getParameters(ht,arg_count,&arg1,&arg2,&arg3)==FAILURE) { WRONG_PARAM_COUNT; }

Using the Function Arguments

The type of each argument is stored in the pval type field. This type can be any of the following:

Table E-1. PHP Internal Types

IS_STRING	String
IS_DOUBLE	Double-precision floating point
IS_LONG	Long integer
IS_ARRAY	Array
IS_EMPTY	None
IS_USER_FUNCTION	??
IS_INTERNAL_FUNCTION	?? (if some of these cannot be passed to a function - delete)
IS_CLASS	??
IS_OBJECT	??

If you get an argument of one type and would like to use it as another, or if you just want to force the argument to be of a certain type, you can use one of the following conversion functions:
convert_to_long(arg1); convert_to_double(arg1); convert_to_string(arg1); convert_to_boolean_long(arg1); /* If the string is "" or "0" it becomes 0, 1 otherwise */ convert_string_to_number(arg1); /* Converts string to either LONG or DOUBLE depending on string */

These function all do in-place conversion. They do not return anything.

The actual argument is stored in a union; the members are:

IS_STRING: arg1->value.str.val
IS_LONG: arg1->value.lval
IS_DOUBLE: arg1->value.dval

Memory Management in Functions

Any memory needed by a function should be allocated with either emalloc() or estrdup(). These are memory handling abstraction functions that look and smell like the normal malloc() and strdup() functions. Memory should be freed with efree().

There are two kinds of memory in this program: memory which is returned to the parser in a variable, and memory which you need for temporary storage in your internal function. When you assign a string to a variable which is returned to the parser you need to make sure you first allocate the memory with either emalloc() or estrdup(). This memory should NEVER be freed by you, unless you later in the same function overwrite your original assignment (this kind of programming practice is not good though).

For any temporary/permanent memory you need in your functions/library you should use the three emalloc(), estrdup(), and efree() functions. They behave EXACTLY like their counterpart functions. Anything you emalloc() or estrdup() you have to efree() at some point or another, unless it's supposed to stick around until the end of the program; otherwise, there will be a memory leak. The meaning of "the functions behave exactly like their counterparts" is: if you efree() something which was not emalloc()'ed nor estrdup()'ed you might get a segmentation fault. So please take care and free all of your wasted memory.

If you compile with "-DDEBUG", PHP will print out a list of all memory that was allocated using emalloc() and estrdup() but never freed with efree() when it is done running the specified script.

Setting Variables in the Symbol Table

A number of macros are available which make it easier to set a variable in the symbol table:

SET_VAR_STRING(name,value)
SET_VAR_DOUBLE(name,value)
SET_VAR_LONG(name,value)

Warning

Be careful with SET_VAR_STRING. The value part must be malloc'ed manually because the memory management code will try to free this pointer later. Do not pass statically allocated memory into a SET_VAR_STRING.

Symbol tables in PHP are implemented as hash tables. At any given time, &symbol_table is a pointer to the 'main' symbol table, and active_symbol_table points to the currently active symbol table (these may be identical like in startup, or different, if you're inside a function).

The following examples use 'active_symbol_table'. You should replace it with &symbol_table if you specifically want to work with the 'main' symbol table. Also, the same functions may be applied to arrays, as explained below.

Example E-3. Checking whether $foo exists in a symbol table
if (hash_exists(active_symbol_table,"foo",sizeof("foo"))) { exists... } else { doesn't exist }

Example E-4. Finding a variable's size in a symbol table
hash_find(active_symbol_table,"foo",sizeof("foo"),&pvalue); check(pvalue.type);
Arrays in PHP are implemented using the same hashtables as symbol tables. This means the two above functions can also be used to check variables inside arrays.

If you want to define a new array in a symbol table, you should do the following.

First, you may want to check whether it exists and abort appropriately, using hash_exists() or hash_find().

Next, initialize the array:

Example E-5. Initializing a new array
pval arr; if (array_init(&arr) == FAILURE) { failed... }; hash_update(active_symbol_table,"foo",sizeof("foo"),&arr,sizeof(pval),NULL);
This code declares a new array, named $foo, in the active symbol table. This array is empty.

Here's how to add new entries to it:

Example E-6. Adding entries to a new array
pval entry; entry.type = IS_LONG; entry.value.lval = 5; /* defines $foo["bar"] = 5 */ hash_update(arr.value.ht,"bar",sizeof("bar"),&entry,sizeof(pval),NULL); /* defines $foo[7] = 5 */ hash_index_update(arr.value.ht,7,&entry,sizeof(pval),NULL); /* defines the next free place in $foo[], * $foo[8], to be 5 (works like php2) */ hash_next_index_insert(arr.value.ht,&entry,sizeof(pval),NULL);
If you'd like to modify a value that you inserted to a hash, you must first retrieve it from the hash. To prevent that overhead, you can supply a pval ** to the hash add function, and it'll be updated with the pval * address of the inserted element inside the hash. If that value is NULL (like in all of the above examples) - that parameter is ignored.

hash_next_index_insert() uses more or less the same logic as "$foo[] = bar;" in PHP 2.0.

If you are building an array to return from a function, you can initialize the array just like above by doing:

if (array_init(return_value) == FAILURE) { failed...; }

...and then adding values with the helper functions:

add_next_index_long(return_value,long_value);
add_next_index_double(return_value,double_value);
add_next_index_string(return_value,estrdup(string_value));

Of course, if the adding isn't done right after the array initialization, you'd probably have to look for the array first:
pval *arr; if (hash_find(active_symbol_table,"foo",sizeof("foo"),(void **)&arr)==FAILURE) { can't find... } else { use arr->value.ht... }

Note that hash_find receives a pointer to a pval pointer, and not a pval pointer.

Just about any hash function returns SUCCESS or FAILURE (except for hash_exists(), which returns a boolean truth value).

Returning simple values

A number of macros are available to make returning values from a function easier.

The RETURN_* macros all set the return value and return from the function:

RETURN
RETURN_FALSE
RETURN_TRUE
RETURN_LONG(l)
RETURN_STRING(s,dup) If dup is TRUE, duplicates the string
RETURN_STRINGL(s,l,dup) Return string (s) specifying length (l).
RETURN_DOUBLE(d)

The RETVAL_* macros set the return value, but do not return.

RETVAL_FALSE
RETVAL_TRUE
RETVAL_LONG(l)
RETVAL_STRING(s,dup) If dup is TRUE, duplicates the string
RETVAL_STRINGL(s,l,dup) Return string (s) specifying length (l).
RETVAL_DOUBLE(d)

The string macros above will all estrdup() the passed 's' argument, so you can safely free the argument after calling the macro, or alternatively use statically allocated memory.

If your function returns boolean success/error responses, always use RETURN_TRUE and RETURN_FALSE respectively.

Returning complex values

Your function can also return a complex data type such as an object or an array.

Returning an object:

Call object_init(return_value).
Fill it up with values. The functions available for this purpose are listed below.
Possibly, register functions for this object. In order to obtain values from the object, the function would have to fetch "this" from the active_symbol_table. Its type should be IS_OBJECT, and it's basically a regular hash table (i.e., you can use regular hash functions on .value.ht). The actual registration of the function can be done using:
add_method( return_value, function_name, function_ptr );

The functions used to populate an object are:

add_property_long( return_value, property_name, l ) - Add a property named 'property_name', of type long, equal to 'l'
add_property_double( return_value, property_name, d ) - Same, only adds a double
add_property_string( return_value, property_name, str ) - Same, only adds a string
add_property_stringl( return_value, property_name, str, l ) - Same, only adds a string of length 'l'

Returning an array:

Call array_init(return_value).
Fill it up with values. The functions available for this purpose are listed below.

The functions used to populate an array are:

add_assoc_long(return_value,key,l) - add associative entry with key 'key' and long value 'l'
add_assoc_double(return_value,key,d)
add_assoc_string(return_value,key,str,duplicate)
add_assoc_stringl(return_value,key,str,length,duplicate) specify the string length
add_index_long(return_value,index,l) - add entry in index 'index' with long value 'l'
add_index_double(return_value,index,d)
add_index_string(return_value,index,str)
add_index_stringl(return_value,index,str,length) - specify the string length
add_next_index_long(return_value,l) - add an array entry in the next free offset with long value 'l'
add_next_index_double(return_value,d)
add_next_index_string(return_value,str)
add_next_index_stringl(return_value,str,length) - specify the string length

Using the resource list

PHP has a standard way of dealing with various types of resources. This replaces all of the local linked lists in PHP 2.0.

Available functions:

php3_list_insert(ptr, type) - returns the 'id' of the newly inserted resource
php3_list_delete(id) - delete the resource with the specified id
php3_list_find(id,*type) - returns the pointer of the resource with the specified id, updates 'type' to the resource's type

Typically, these functions are used for SQL drivers but they can be used for anything else; for instance, maintaining file descriptors.

Typical list code would look like this:

Example E-7. Adding a new resource
RESOURCE *resource; /* ...allocate memory for resource and acquire resource... */ /* add a new resource to the list */ return_value->value.lval = php3_list_insert((void *) resource, LE_RESOURCE_TYPE); return_value->type = IS_LONG;

Example E-8. Using an existing resource
pval *resource_id; RESOURCE *resource; int type; convert_to_long(resource_id); resource = php3_list_find(resource_id->value.lval, &type); if (type != LE_RESOURCE_TYPE) { php3_error(E_WARNING,"resource index %d has the wrong type",resource_id->value.lval); RETURN_FALSE; } /* ...use resource... */

Example E-9. Deleting an existing resource
pval *resource_id; RESOURCE *resource; int type; convert_to_long(resource_id); php3_list_delete(resource_id->value.lval);
The resource types should be registered in php3_list.h, in enum list_entry_type. In addition, one should add shutdown code for any new resource type defined, in list.c's list_entry_destructor() (even if you don't have anything to do on shutdown, you must add an empty case).

Using the persistent resource table

PHP has a standard way of storing persistent resources (i.e., resources that are kept in between hits). The first module to use this feature was the MySQL module, and mSQL followed it, so one can get the general impression of how a persistent resource should be used by reading mysql.c. The functions you should look at are:

php3_mysql_do_connect

php3_mysql_connect()

php3_mysql_pconnect()

The general idea of persistence modules is this:

Code all of your module to work with the regular resource list mentioned in section (9).
Code extra connect functions that check if the resource already exists in the persistent resource list. If it does, register it as in the regular resource list as a pointer to the persistent resource list (because of 1., the rest of the code should work immediately). If it doesn't, then create it, add it to the persistent resource list AND add a pointer to it from the regular resource list, so all of the code would work since it's in the regular resource list, but on the next connect, the resource would be found in the persistent resource list and be used without having to recreate it. You should register these resources with a different type (e.g. LE_MYSQL_LINK for non-persistent link and LE_MYSQL_PLINK for a persistent link).

If you read mysql.c, you'll notice that except for the more complex connect function, nothing in the rest of the module has to be changed.

The very same interface exists for the regular resource list and the persistent resource list, only 'list' is replaced with 'plist':

php3_plist_insert(ptr, type) - returns the 'id' of the newly inserted resource
php3_plist_delete(id) - delete the resource with the specified id
php3_plist_find(id,*type) - returns the pointer of the resource with the specified id, updates 'type' to the resource's type

However, it's more than likely that these functions would prove to be useless for you when trying to implement a persistent module. Typically, one would want to use the fact that the persistent resource list is really a hash table. For instance, in the MySQL/mSQL modules, when there's a pconnect() call (persistent connect), the function builds a string out of the host/user/passwd that were passed to the function, and hashes the SQL link with this string as a key. The next time someone calls a pconnect() with the same host/user/passwd, the same key would be generated, and the function would find the SQL link in the persistent list.

Until further documented, you should look at mysql.c or msql.c to see how one should use the plist's hash table abilities.

One important thing to note: resources going into the persistent resource list must *NOT* be allocated with PHP's memory manager, i.e., they should NOT be created with emalloc(), estrdup(), etc. Rather, one should use the regular malloc(), strdup(), etc. The reason for this is simple - at the end of the request (end of the hit), every memory chunk that was allocated using PHP's memory manager is deleted. Since the persistent list isn't supposed to be erased at the end of a request, one mustn't use PHP's memory manager for allocating resources that go to it.

When you register a resource that's going to be in the persistent list, you should add destructors to it both in the non-persistent list and in the persistent list. The destructor in the non-persistent list destructor shouldn't do anything. The one in the persistent list destructor should properly free any resources obtained by that type (e.g. memory, SQL links, etc). Just like with the non-persistent resources, you *MUST* add destructors for every resource, even it requires no destruction and the destructor would be empty. Remember, since emalloc() and friends aren't to be used in conjunction with the persistent list, you mustn't use efree() here either.

Adding runtime configuration directives

Many of the features of PHP can be configured at runtime. These configuration directives can appear in either the designated php3.ini file, or in the case of the Apache module version in the Apache .conf files. The advantage of having them in the Apache .conf files is that they can be configured on a per-directory basis. This means that one directory may have a certain safemodeexecdir for example, while another directory may have another. This configuration granularity is especially handy when a server supports multiple virtual hosts.

The steps required to add a new directive:

Add directive to php3_ini_structure struct in mod_php3.h.
In main.c, edit the php3_module_startup function and add the appropriate cfg_get_string() or cfg_get_long() call.
Add the directive, restrictions and a comment to the php3_commands structure in mod_php3.c. Note the restrictions part. RSRC_CONF are directives that can only be present in the actual Apache .conf files. Any OR_OPTIONS directives can be present anywhere, include normal .htaccess files.
In either php3take1handler() or php3flaghandler() add the appropriate entry for your directive.
In the configuration section of the _php3_info() function in functions/info.c you need to add your new directive.
And last, you of course have to use your new directive somewhere. It will be addressable as php3_ini.directive.

Calling User Functions

To call user functions from an internal function, you should use the call_user_function() function.

call_user_function() returns SUCCESS on success, and FAILURE in case the function cannot be found. You should check that return value! If it returns SUCCESS, you are responsible for destroying the retval pval yourself (or return it as the return value of your function). If it returns FAILURE, the value of retval is undefined, and you mustn't touch it.

All internal functions that call user functions must be reentrant. Among other things, this means they must not use globals or static variables.

call_user_function() takes six arguments:

HashTable *function_table

This is the hash table in which the function is to be looked up.

pval *object

This is a pointer to an object on which the function is invoked. This should be NULL if a global function is called. If it's not NULL (i.e. it points to an object), the function_table argument is ignored, and instead taken from the object's hash. The object *may* be modified by the function that is invoked on it (that function will have access to it via $this). If for some reason you don't want that to happen, send a copy of the object instead.

pval *function_name

The name of the function to call. Must be a pval of type IS_STRING with function_name.str.val and function_name.str.len set to the appropriate values. The function_name is modified by call_user_function() - it's converted to lowercase. If you need to preserve the case, send a copy of the function name instead.

pval *retval

A pointer to a pval structure, into which the return value of the invoked function is saved. The structure must be previously allocated - call_user_function() does NOT allocate it by itself.

int param_count

The number of parameters being passed to the function.

pval *params[]

An array of pointers to values that will be passed as arguments to the function, the first argument being in offset 0, the second in offset 1, etc. The array is an array of pointers to pval's; The pointers are sent as-is to the function, which means if the function modifies its arguments, the original values are changed (passing by reference). If you don't want that behavior, pass a copy instead.

Reporting Errors

To report errors from an internal function, you should call the php3_error() function. This takes at least two parameters -- the first is the level of the error, the second is the format string for the error message (as in a standard printf() call), and any following arguments are the parameters for the format string. The error levels are:

E_NOTICE

Notices are not printed by default, and indicate that the script encountered something that could indicate an error, but could also happen in the normal course of running a script. For example, trying to access the value of a variable which has not been set, or calling stat() on a file that doesn't exist.

E_WARNING

Warnings are printed by default, but do not interrupt script execution. These indicate a problem that should have been trapped by the script before the call was made. For example, calling ereg() with an invalid regular expression.

E_ERROR

Errors are also printed by default, and execution of the script is halted after the function returns. These indicate errors that can not be recovered from, such as a memory allocation problem.

E_PARSE

Parse errors should only be generated by the parser. The code is listed here only for the sake of completeness.

E_CORE_ERROR

This is like an E_ERROR, except it is generated by the core of PHP. Functions should not generate this type of error.

E_CORE_WARNING

This is like an E_WARNING, except it is generated by the core of PHP. Functions should not generate this type of error.

E_COMPILE_ERROR

This is like an E_ERROR, except it is generated by the Zend Scripting Engine. Functions should not generate this type of error.

E_COMPILE_WARNING

This is like an E_WARNING, except it is generated by the Zend Scripting Engine. Functions should not generate this type of error.

E_USER_ERROR

This is like an E_ERROR, except it is generated in PHP code by using the PHP function trigger_error(). Functions should not generate this type of error.

E_USER_WARNING

This is like an E_WARNING, except it is generated by using the PHP function trigger_error(). Functions should not generate this type of error.

E_USER_NOTICE

This is like an E_NOTICE, except it is generated by using the PHP function trigger_error(). Functions should not generate this type of error.

E_ALL

All of the above. Using this error_reporting level will show all error types.

Appendix F. List of Function Aliases

Here is the aliases list. All aliases are listed here. It is usually a bad idea to use aliases, as they may be bound to obsolescence or renaming, which will lead to unportable script. This list is provided to help those who want to upgrade their old scripts to newer syntax.

However, some functions simply have two names, and there is no real preference. (For example, is_int() and is_integer() are equally good)

This list is consistent with PHP 4.0.6.

Table F-1. Aliases

Alias	Master function	Extension used
_	gettext()	Gettext
add	swfmovie_add()	Ming (flash)
add	swfsprite_add()	Ming (flash)
add_root	domxml_add_root()	DOM XML
addaction	swfbutton_addAction()	Ming (flash)
addcolor	swfdisplayitem_addColor()	Ming (flash)
addentry	swfgradient_addEntry()	Ming (flash)
addfill	swfshape_addfill()	Ming (flash)
addshape	swfbutton_addShape()	Ming (flash)
addstring	swftext_addString()	Ming (flash)
addstring	swftextfield_addString()	Ming (flash)
align	swftextfield_align()	Ming (flash)
attributes	domxml_attributes()	DOM XML
children	domxml_children()	DOM XML
chop	rtrim()	Base syntax
close	closedir()	Base syntax
com_get	com_propget()	COM
com_propset	com_propput()	COM
com_set	com_propput()	COM
cv_add	ccvs_add()	CCVS
cv_auth	ccvs_auth()	CCVS
cv_command	ccvs_command()	CCVS
cv_count	ccvs_count()	CCVS
cv_delete	ccvs_delete()	CCVS
cv_done	ccvs_done()	CCVS
cv_init	ccvs_init()	CCVS
cv_lookup	ccvs_lookup()	CCVS
cv_new	ccvs_new()	CCVS
cv_report	ccvs_report()	CCVS
cv_return	ccvs_return()	CCVS
cv_reverse	ccvs_reverse()	CCVS
cv_sale	ccvs_sale()	CCVS
cv_status	ccvs_status()	CCVS
cv_textvalue	ccvs_textvalue()	CCVS
cv_void	ccvs_void()	CCVS
die	exit()	Miscellaneous functions
dir	getdir()	Base syntax
diskfreespace	disk_free_space()	Filesystem
domxml_getattr	domxml_get_attribute()	DOM XML
domxml_setattr	domxml_set_attribute()	DOM XML
doubleval	floatval()	Base syntax
drawarc	swfshape_drawarc()	Ming (flash)
drawcircle	swfshape_drawcircle()	Ming (flash)
drawcubic	swfshape_drawcubic()	Ming (flash)
drawcubicto	swfshape_drawcubicto()	Ming (flash)
drawcurve	swfshape_drawcurve()	Ming (flash)
drawcurveto	swfshape_drawcurveto()	Ming (flash)
drawglyph	swfshape_drawglyph()	Ming (flash)
drawline	swfshape_drawline()	Ming (flash)
drawlineto	swfshape_drawlineto()	Ming (flash)
dtd	domxml_intdtd()	DOM XML
dumpmem	domxml_dumpmem()	DOM XML
fbsql	fbsql_db_query()	FrontBase
fputs	fwrite()	Base syntax
get_attribute	domxml_get_attribute()	DOM XML
getascent	swffont_getAscent()	Ming (flash)
getascent	swftext_getAscent()	Ming (flash)
getattr	domxml_get_attribute()	DOM XML
getdescent	swffont_getDescent()	Ming (flash)
getdescent	swftext_getDescent()	Ming (flash)
getheight	swfbitmap_getHeight()	Ming (flash)
getleading	swffont_getLeading()	Ming (flash)
getleading	swftext_getLeading()	Ming (flash)
getshape1	swfmorph_getShape1()	Ming (flash)
getshape2	swfmorph_getShape2()	Ming (flash)
getwidth	swfbitmap_getWidth()	Ming (flash)
getwidth	swffont_getWidth()	Ming (flash)
getwidth	swftext_getWidth()	Ming (flash)
gzputs	gzwrite()	Zlib
i18n_convert	mb_convert_encoding()	Multi-bytes Strings
i18n_discover_encoding	mb_detect_encoding()	Multi-bytes Strings
i18n_http_input	mb_http_input()	Multi-bytes Strings
i18n_http_output	mb_http_output()	Multi-bytes Strings
i18n_internal_encoding	mb_internal_encoding()	Multi-bytes Strings
i18n_ja_jp_hantozen	mb_convert_kana()	Multi-bytes Strings
i18n_mime_header_decode	mb_decode_mimeheader()	Multi-bytes Strings
i18n_mime_header_encode	mb_encode_mimeheader()	Multi-bytes Strings
imap_create	imap_createmailbox()	IMAP
imap_fetchtext	imap_body()	IMAP
imap_getmailboxes	imap_list_full()	IMAP
imap_getsubscribed	imap_lsub_full()	IMAP
imap_header	imap_headerinfo()	IMAP
imap_listmailbox	imap_list()	IMAP
imap_listsubscribed	imap_lsub()	IMAP
imap_rename	imap_renamemailbox()	IMAP
imap_scan	imap_listscan()	IMAP
imap_scanmailbox	imap_listscan()	IMAP
ini_alter	ini_set()	Base syntax
is_double	is_float()	Base syntax
is_integer	is_int()	Base syntax
is_long	is_int()	Base syntax
is_real	is_float()	Base syntax
is_writeable	is_writable()	Base syntax
join	implode()	Base syntax
labelframe	swfmovie_labelFrame()	Ming (flash)
labelframe	swfsprite_labelFrame()	Ming (flash)
last_child	domxml_last_child()	DOM XML
lastchild	domxml_last_child()	DOM XML
ldap_close	ldap_unbind()	LDAP
magic_quotes_runtime	set_magic_quotes_runtime()	Base syntax
mbstrcut	mb_strcut()	Multi-bytes Strings
mbstrlen	mb_strlen()	Multi-bytes Strings
mbstrpos	mb_strpos()	Multi-bytes Strings
mbstrrpos	mb_strrpos()	Multi-bytes Strings
mbsubstr	mb_substr()	Multi-bytes Strings
ming_setcubicthreshold	ming_setCubicThreshold()	Ming (flash)
ming_setscale	ming_setScale()	Ming (flash)
move	swfdisplayitem_move()	Ming (flash)
movepen	swfshape_movepen()	Ming (flash)
movepento	swfshape_movepento()	Ming (flash)
moveto	swfdisplayitem_moveTo()	Ming (flash)
moveto	swffill_moveTo()	Ming (flash)
moveto	swftext_moveTo()	Ming (flash)
msql	msql_db_query()	mSQL
msql_createdb	msql_create_db()	mSQL
msql_dbname	msql_result()	mSQL
msql_dropdb	msql_drop_db()	mSQL
msql_fieldflags	msql_field_flags()	mSQL
msql_fieldlen	msql_field_len()	mSQL
msql_fieldname	msql_field_name()	mSQL
msql_fieldtable	msql_field_table()	mSQL
msql_fieldtype	msql_field_type()	mSQL
msql_freeresult	msql_free_result()	mSQL
msql_listdbs	msql_list_dbs()	mSQL
msql_listfields	msql_list_fields()	mSQL
msql_listtables	msql_list_tables()	mSQL
msql_numfields	msql_num_fields()	mSQL
msql_numrows	msql_num_rows()	mSQL
msql_regcase	sql_regcase()	mSQL
msql_selectdb	msql_select_db()	mSQL
msql_tablename	msql_result()	mSQL
mssql_affected_rows	sybase_affected_rows()	Sybase
mssql_affected_rows	sybase_affected_rows()	Sybase
mssql_close	sybase_close()	Sybase
mssql_close	sybase_close()	Sybase
mssql_connect	sybase_connect()	Sybase
mssql_connect	sybase_connect()	Sybase
mssql_data_seek	sybase_data_seek()	Sybase
mssql_data_seek	sybase_data_seek()	Sybase
mssql_fetch_array	sybase_fetch_array()	Sybase
mssql_fetch_array	sybase_fetch_array()	Sybase
mssql_fetch_field	sybase_fetch_field()	Sybase
mssql_fetch_field	sybase_fetch_field()	Sybase
mssql_fetch_object	sybase_fetch_object()	Sybase
mssql_fetch_object	sybase_fetch_object()	Sybase
mssql_fetch_row	sybase_fetch_row()	Sybase
mssql_fetch_row	sybase_fetch_row()	Sybase
mssql_field_seek	sybase_field_seek()	Sybase
mssql_field_seek	sybase_field_seek()	Sybase
mssql_free_result	sybase_free_result()	Sybase
mssql_free_result	sybase_free_result()	Sybase
mssql_get_last_message	sybase_get_last_message()	Sybase
mssql_get_last_message	sybase_get_last_message()	Sybase
mssql_min_client_severity	sybase_min_client_severity()	Sybase
mssql_min_error_severity	sybase_min_error_severity()	Sybase
mssql_min_message_severity	sybase_min_message_severity()	Sybase
mssql_min_server_severity	sybase_min_server_severity()	Sybase
mssql_num_fields	sybase_num_fields()	Sybase
mssql_num_fields	sybase_num_fields()	Sybase
mssql_num_rows	sybase_num_rows()	Sybase
mssql_num_rows	sybase_num_rows()	Sybase
mssql_pconnect	sybase_pconnect()	Sybase
mssql_pconnect	sybase_pconnect()	Sybase
mssql_query	sybase_query()	Sybase
mssql_query	sybase_query()	Sybase
mssql_result	sybase_result()	Sybase
mssql_result	sybase_result()	Sybase
mssql_select_db	sybase_select_db()	Sybase
mssql_select_db	sybase_select_db()	Sybase
multcolor	swfdisplayitem_multColor()	Ming (flash)
mysql	mysql_db_query()	MySQL
mysql_createdb	mysql_create_db()	MySQL
mysql_db_name	mysql_result()	MySQL
mysql_dbname	mysql_result()	MySQL
mysql_dropdb	mysql_drop_db()	MySQL
mysql_fieldflags	mysql_field_flags()	MySQL
mysql_fieldlen	mysql_field_len()	MySQL
mysql_fieldname	mysql_field_name()	MySQL
mysql_fieldtable	mysql_field_table()	MySQL
mysql_fieldtype	mysql_field_type()	MySQL
mysql_freeresult	mysql_free_result()	MySQL
mysql_listdbs	mysql_list_dbs()	MySQL
mysql_listfields	mysql_list_fields()	MySQL
mysql_listtables	mysql_list_tables()	MySQL
mysql_numfields	mysql_num_fields()	MySQL
mysql_numrows	mysql_num_rows()	MySQL
mysql_selectdb	mysql_select_db()	MySQL
mysql_tablename	mysql_result()	MySQL
name	domxml_attrname()	DOM XML
new_child	domxml_new_child()	DOM XML
new_xmldoc	domxml_new_xmldoc()	DOM XML
nextframe	swfmovie_nextFrame()	Ming (flash)
nextframe	swfsprite_nextFrame()	Ming (flash)
node	domxml_node()	DOM XML
oci8append	ocicollappend()	OCI8
oci8assign	ocicollassign()	OCI8
oci8assignelem	ocicollassignelem()	OCI8
oci8close	ocicloselob()	OCI8
oci8free	ocifreecoll()	OCI8
oci8free	ocifreedesc()	OCI8
oci8getelem	ocicollgetelem()	OCI8
oci8load	ociloadlob()	OCI8
oci8max	ocicollmax()	OCI8
oci8ocifreecursor	ocifreestatement()	OCI8
oci8save	ocisavelob()	OCI8
oci8savefile	ocisavelobfile()	OCI8
oci8size	ocicollsize()	OCI8
oci8trim	ocicolltrim()	OCI8
oci8writetemporary	ociwritetemporarylob()	OCI8
oci8writetofile	ociwritelobtofile()	OCI8
odbc_do	odbc_exec()	OCI8
odbc_field_precision	odbc_field_len()	OCI8
output	swfmovie_output()	Ming (flash)
parent	domxml_parent()	DOM XML
pdf_add_outline	pdf_add_bookmark()	PDF
pg_clientencoding	pg_client_encoding()	PostgreSQL
pg_setclientencoding	pg_set_client_encoding()	PostgreSQL
pos	current()	Base syntax
recode	recode_string()	Recode
remove	swfmovie_remove()	Ming (flash)
remove	swfsprite_remove()	Ming (flash)
rewind	rewinddir()	Base syntax
root	domxml_root()	DOM XML
rotate	swfdisplayitem_rotate()	Ming (flash)
rotateto	swfdisplayitem_rotateTo()	Ming (flash)
rotateto	swffill_rotateTo()	Ming (flash)
save	swfmovie_save()	Ming (flash)
savetofile	swfmovie_saveToFile()	Ming (flash)
scale	swfdisplayitem_scale()	Ming (flash)
scaleto	swfdisplayitem_scaleTo()	Ming (flash)
scaleto	swffill_scaleTo()	Ming (flash)
set_attribute	domxml_set_attribute()	DOM XML
set_content	domxml_set_content()	DOM XML
setaction	swfbutton_setAction()	Ming (flash)
setattr	domxml_set_attribute()	DOM XML
setbackground	swfmovie_setBackground()	Ming (flash)
setbounds	swftextfield_setBounds()	Ming (flash)
setcolor	swftext_setColor()	Ming (flash)
setcolor	swftextfield_setColor()	Ming (flash)
setdepth	swfdisplayitem_setDepth()	Ming (flash)
setdimension	swfmovie_setDimension()	Ming (flash)
setdown	swfbutton_setDown()	Ming (flash)
setfont	swftext_setFont()	Ming (flash)
setfont	swftextfield_setFont()	Ming (flash)
setframes	swfmovie_setFrames()	Ming (flash)
setframes	swfsprite_setFrames()	Ming (flash)
setheight	swftext_setHeight()	Ming (flash)
setheight	swftextfield_setHeight()	Ming (flash)
sethit	swfbutton_setHit()	Ming (flash)
setindentation	swftextfield_setIndentation()	Ming (flash)
setleftfill	swfshape_setleftfill()	Ming (flash)
setleftmargin	swftextfield_setLeftMargin()	Ming (flash)
setline	swfshape_setline()	Ming (flash)
setlinespacing	swftextfield_setLineSpacing()	Ming (flash)
setmargins	swftextfield_setMargins()	Ming (flash)
setmatrix	swfdisplayitem_setMatrix()	Ming (flash)
setname	swfdisplayitem_setName()	Ming (flash)
setname	swftextfield_setName()	Ming (flash)
setover	swfbutton_setOver()	Ming (flash)
setrate	swfmovie_setRate()	Ming (flash)
setratio	swfdisplayitem_setRatio()	Ming (flash)
setrightfill	swfshape_setrightfill()	Ming (flash)
setrightmargin	swftextfield_setRightMargin()	Ming (flash)
setspacing	swftext_setSpacing()	Ming (flash)
setup	swfbutton_setUp()	Ming (flash)
show_source	highlight_file ()	Base syntax
sizeof	count()	Base syntax
skewx	swfdisplayitem_skewX()	Ming (flash)
skewxto	swfdisplayitem_skewXTo()	Ming (flash)
skewxto	swffill_skewXTo()	Ming (flash)
skewy	swfdisplayitem_skewY()	Ming (flash)
skewyto	swfdisplayitem_skewYTo()	Ming (flash)
skewyto	swffill_skewYTo()	Ming (flash)
snmpwalkoid	snmprealwalk()	SNMP
strchr	strstr()	Base syntax
streammp3	swfmovie_streamMp3()	Ming (flash)
swfaction	swfaction_init()	Ming (flash)
swfbitmap	swfbitmap_init()	Ming (flash)
swfbutton	swfbutton_init()	Ming (flash)
swffill	swffill_init()	Ming (flash)
swffont	swffont_init()	Ming (flash)
swfgradient	swfgradient_init()	Ming (flash)
swfmorph	swfmorph_init()	Ming (flash)
swfmovie	swfmovie_init()	Ming (flash)
swfshape	swfshape_init()	Ming (flash)
swfsprite	swfsprite_init()	Ming (flash)
swftext	swftext_init()	Ming (flash)
swftextfield	swftextfield_init()	Ming (flash)
unlink	domxml_unlink_node()	DOM XML
xptr_new_context	xpath_new_context()	DOM XML

Appendix G. List of Reserved Words

The following is a listing of predefined identifiers in PHP. None of the identifiers listed here should be used as identifiers in a your scripts. These lists include keywords and predefined variable, constant, and class names. These lists are neither exhaustive or complete.

List of Keywords

These words have special meaning in PHP. Some of them represent things which look like functions, some look like constants, and so on--but they're not, really: they are language constructs. You cannot use any of the following words as constants, class names, or function names. Using them as variable names is generally OK, but could lead to confusion.

Table G-1. PHP Keywords

and	or	xor	__FILE__
__LINE__	array()	as	break	case
cfunction	class	const	continue	declare
default	die()	do	echo()	else
elseif	empty()	enddeclare	endfor	endforeach
endif	endswitch	endwhile	eval	exit()
extends	for	foreach	function	global
if	include()	include_once()	isset()	list()
new	old_function	print()	require()	require_once()
return()	static	switch	unset()	use
var	while	`__FUNCTION__`	`__CLASS__`

Predefined Variables

Server variables: `$_SERVER`

Note: Introduced in 4.1.0. In earlier versions, use $HTTP_SERVER_VARS.

$_SERVER is an array containing information such as headers, paths, and script locations. The entries in this array are created by the webserver. There is no guarantee that every webserver will provide any of these; servers may omit some, or provide others not listed here. That said, a large number of these variables are accounted for in the CGI 1.1 specification, so you should be able to expect those.

This is a 'superglobal', or automatic global, variable. This simply means that it is available in all scopes throughout a script. You don't need to do a global $_SERVER; to access it within functions or methods, as you do with $HTTP_SERVER_VARS.

$HTTP_SERVER_VARS contains the same initial information, but is not an autoglobal. (Note that $HTTP_SERVER_VARS and $_SERVER are different variables and that PHP handles them as such)

If the register_globals directive is set, then these variables will also be made available in the global scope of the script; i.e., separate from the $_SERVER and $HTTP_SERVER_VARS arrays. For related information, see the security chapter titled Using Register Globals. These individual globals are not autoglobals.

You may or may not find any of the following elements in $_SERVER. Note that few, if any, of these will be available (or indeed have any meaning) if running PHP on the command line.

'PHP_SELF'

The filename of the currently executing script, relative to the document root. For instance, $_SERVER['PHP_SELF'] in a script at the address http://example.com/test.php/foo.bar would be /test.php/foo.bar.

If PHP is running as a command-line processor, this variable is not available.

'argv'

Array of arguments passed to the script. When the script is run on the command line, this gives C-style access to the command line parameters. When called via the GET method, this will contain the query string.

'argc'

Contains the number of command line parameters passed to the script (if run on the command line).

'GATEWAY_INTERFACE'

What revision of the CGI specification the server is using; i.e. 'CGI/1.1'.

'SERVER_NAME'

The name of the server host under which the current script is executing. If the script is running on a virtual host, this will be the value defined for that virtual host.

'SERVER_SOFTWARE'

Server identification string, given in the headers when responding to requests.

'SERVER_PROTOCOL'

Name and revision of the information protocol via which the page was requested; i.e. 'HTTP/1.0';

'REQUEST_METHOD'

Which request method was used to access the page; i.e. 'GET', 'HEAD', 'POST', 'PUT'.

'QUERY_STRING'

The query string, if any, via which the page was accessed.

'DOCUMENT_ROOT'

The document root directory under which the current script is executing, as defined in the server's configuration file.

'HTTP_ACCEPT'

Contents of the Accept: header from the current request, if there is one.

'HTTP_ACCEPT_CHARSET'

Contents of the Accept-Charset: header from the current request, if there is one. Example: 'iso-8859-1,*,utf-8'.

'HTTP_ACCEPT_ENCODING'

Contents of the Accept-Encoding: header from the current request, if there is one. Example: 'gzip'.

'HTTP_ACCEPT_LANGUAGE'

Contents of the Accept-Language: header from the current request, if there is one. Example: 'en'.

'HTTP_CONNECTION'

Contents of the Connection: header from the current request, if there is one. Example: 'Keep-Alive'.

'HTTP_HOST'

Contents of the Host: header from the current request, if there is one.

'HTTP_REFERER'

The address of the page (if any) which referred the user agent to the current page. This is set by the user agent. Not all user agents will set this, and some provide the ability to modify HTTP_REFERER as a feature. In short, it cannot really be trusted.

'HTTP_USER_AGENT'

Contents of the User_Agent: header from the current request, if there is one. This is a string denoting the user agent being which is accessing the page. A typical example is: Mozilla/4.5 [en] (X11; U; Linux 2.2.9 i586). Among other things, you can use this value with get_browser() to tailor your page's output to the capabilities of the user agent.

'REMOTE_ADDR'

The IP address from which the user is viewing the current page.

'REMOTE_PORT'

The port being used on the user's machine to communicate with the web server.

'SCRIPT_FILENAME'

The absolute pathname of the currently executing script.

'SERVER_ADMIN'

The value given to the SERVER_ADMIN (for Apache) directive in the web server configuration file. If the script is running on a virtual host, this will be the value defined for that virtual host.

'SERVER_PORT'

The port on the server machine being used by the web server for communication. For default setups, this will be '80'; using SSL, for instance, will change this to whatever your defined secure HTTP port is.

'SERVER_SIGNATURE'

String containing the server version and virtual host name which are added to server-generated pages, if enabled.

'PATH_TRANSLATED'

Filesystem- (not document root-) based path to the current script, after the server has done any virtual-to-real mapping.

'SCRIPT_NAME'

Contains the current script's path. This is useful for pages which need to point to themselves.

'REQUEST_URI'

The URI which was given in order to access this page; for instance, '/index.html'.

'PHP_AUTH_USER'

When running under Apache as module doing HTTP authentication this variable is set to the username provided by the user.

'PHP_AUTH_PW'

When running under Apache as module doing HTTP authentication this variable is set to the password provided by the user.

'PHP_AUTH_TYPE'

When running under Apache as module doing HTTP authenticated this variable is set to the authentication type.

Environment variables: `$_ENV`

Note: Introduced in 4.1.0. In earlier versions, use $HTTP_ENV_VARS.

These variables are imported into PHP's global namespace from the environment under which the PHP parser is running. Many are provided by the shell under which PHP is running and different systems are likely running different kinds of shells, a definitive list is impossible. Please see your shell's documentation for a list of defined environment variables.

Other environment variables include the CGI variables, placed there regardless of whether PHP is running as a server module or CGI processor.

This is a 'superglobal', or automatic global, variable. This simply means that it is available in all scopes throughout a script. You don't need to do a global $_ENV; to access it within functions or methods, as you do with $HTTP_ENV_VARS.

$HTTP_ENV_VARS contains the same initial information, but is not an autoglobal. (Note that HTTP_ENV_VARS and $_ENV are different variables and that PHP handles them as such)

If the register_globals directive is set, then these variables will also be made available in the global scope of the script; i.e., separate from the $_ENV and $HTTP_ENV_VARS arrays. For related information, see the security chapter titled Using Register Globals. These individual globals are not autoglobals.

HTTP Cookies: `$_COOKIE`

Note: Introduced in 4.1.0. In earlier versions, use $HTTP_COOKIE_VARS.

An associative array of variables passed to the current script via HTTP cookies. Automatically global in any scope.

This is a 'superglobal', or automatic global, variable. This simply means that it is available in all scopes throughout a script. You don't need to do a global $_COOKIE; to access it within functions or methods, as you do with $HTTP_COOKIE_VARS.

$HTTP_COOKIE_VARS contains the same initial information, but is not an autoglobal. (Note that HTTP_COOKIE_VARS and $_COOKIE are different variables and that PHP handles them as such)

If the register_globals directive is set, then these variables will also be made available in the global scope of the script; i.e., separate from the $_COOKIE and $HTTP_COOKIE_VARS arrays. For related information, see the security chapter titled Using Register Globals. These individual globals are not autoglobals.

HTTP GET variables: `$_GET`

Note: Introduced in 4.1.0. In earlier versions, use $HTTP_GET_VARS.

An associative array of variables passed to the current script via the HTTP GET method. Automatically global in any scope.

This is a 'superglobal', or automatic global, variable. This simply means that it is available in all scopes throughout a script. You don't need to do a global $_GET; to access it within functions or methods, as you do with $HTTP_GET_VARS.

$HTTP_GET_VARS contains the same initial information, but is not an autoglobal. (Note that HTTP_GET_VARS and $_GET are different variables and that PHP handles them as such)

If the register_globals directive is set, then these variables will also be made available in the global scope of the script; i.e., separate from the $_GET and $HTTP_GET_VARS arrays. For related information, see the security chapter titled Using Register Globals. These individual globals are not autoglobals.

HTTP POST variables: `$_POST`

Note: Introduced in 4.1.0. In earlier versions, use $HTTP_POST_VARS.

An associative array of variables passed to the current script via the HTTP POST method. Automatically global in any scope.

This is a 'superglobal', or automatic global, variable. This simply means that it is available in all scopes throughout a script. You don't need to do a global $_POST; to access it within functions or methods, as you do with $HTTP_POST_VARS.

$HTTP_POST_VARS contains the same initial information, but is not an autoglobal. (Note that HTTP_POST_VARS and $_POST are different variables and that PHP handles them as such)

If the register_globals directive is set, then these variables will also be made available in the global scope of the script; i.e., separate from the $_POST and $HTTP_POST_VARS arrays. For related information, see the security chapter titled Using Register Globals. These individual globals are not autoglobals.

HTTP File upload variables: `$_FILES`

Note: Introduced in 4.1.0. In earlier versions, use $HTTP_POST_FILES.

An associative array of items uploaded to the current script via the HTTP POST method. Automatically global in any scope.

This is a 'superglobal', or automatic global, variable. This simply means that it is available in all scopes throughout a script. You don't need to do a global $_FILES; to access it within functions or methods, as you do with $HTTP_POST_FILES.

$HTTP_POST_FILES contains the same information, but is not an autoglobal.

If the register_globals directive is set, then these variables will also be made available in the global scope of the script; i.e., separate from the $_FILES and $HTTP_POST_FILES arrays. For related information, see the security chapter titled Using Register Globals. These individual globals are not autoglobals.

Request variables: `$_REQUEST`

Note: Introduced in 4.1.0. There is no equivalent array in earlier versions.

An associative array consisting of the contents of $_GET, $_POST, $_COOKIE, and $_FILES.

This is a 'superglobal', or automatic global, variable. This simply means that it is available in all scopes throughout a script. You don't need to do a global $_REQUEST; to access it within functions or methods.

If the register_globals directive is set, then these variables will also be made available in the global scope of the script; i.e., separate from the $_REQUEST array. For related information, see the security chapter titled Using Register Globals. These individual globals are not autoglobals.

Session variables: `$_SESSION`

Note: Introduced in 4.1.0. In earlier versions, use $HTTP_SESSION_VARS.

An associative array containing session variables available to the current script. See the Session functions documentation for more information on how this is used.

This is a 'superglobal', or automatic global, variable. This simply means that it is available in all scopes throughout a script. You don't need to do a global $_SESSION; to access it within functions or methods, as you do with $HTTP_SESSION_VARS.

$HTTP_SESSION_VARS contains the same information, but is not an autoglobal.

If the register_globals directive is set, then these variables will also be made available in the global scope of the script; i.e., separate from the $_SESSION and $HTTP_SESSION_VARS arrays. For related information, see the security chapter titled Using Register Globals. These individual globals are not autoglobals.

Global variables: `$GLOBALS`

Note: $GLOBALS has been available since PHP 3.0.0.

An associative array containing references to all variables which are currently defined in the global scope of the script. The variable names are the keys of the array.

This is a 'superglobal', or automatic global, variable. This simply means that it is available in all scopes throughout a script. You don't need to do a global $GLOBALS; to access it within functions or methods.

The previous error message: `$php_errormsg`

$php_errormsg is a variable containing the text of the last error message generated by PHP. This variable will only be available within the scope in which the error occurred, and only if the track_errors configuration option is turned on (it defaults to off).

Predefined Classes

Standard Defined Classes

These classes are defined in the standard set of functions included in the PHP build.

Directory: The class from which dir() is instantiated.
stdClass

Ming Defined Classes

These classes are defined in the Ming extension, and will only be available when that extension has either been compiled into PHP or dynamically loaded at runtime.

swfshape
swffill
swfgradient
swfbitmap
swftext
swftextfield
swffont
swfdisplayitem
swfmovie
swfbutton
swfaction
swfmorph
swfsprite

Oracle 8 Defined Classes

These classes are defined in the Oracle 8 extension, and will only be available when that extension has either been compiled into PHP or dynamically loaded at runtime.

OCI-Lob
OCI-Collection

qtdom Defined Classes

These classes are defined in the qtdom extension, and will only be available when that extension has either been compiled into PHP or dynamically loaded at runtime.

QDomDocument
QDomNode

Predefined Constants

Table of Contents
Core Predefined Constants -- Constants defined in the PHP core, Zend, and SAPI modules
Standard Predefined Constants -- Constants defined in PHP by default

Core Predefined Constants

Core Predefined Constants -- Constants defined in the PHP core, Zend, and SAPI modules

Description

These constants are defined by the PHP core. This includes PHP, the Zend engine, and SAPI modules.

PHP_VERSION (string)
PHP_OS (string)
DEFAULT_INCLUDE_PATH (string)
PEAR_INSTALL_DIR (string)
PEAR_EXTENSION_DIR (string)
PHP_EXTENSION_DIR (string)
PHP_BINDIR (string)
PHP_LIBDIR (string)
PHP_DATADIR (string)
PHP_SYSCONFDIR (string)
PHP_LOCALSTATEDIR (string)
PHP_CONFIG_FILE_PATH (string)
PHP_OUTPUT_HANDLER_START (integer)
PHP_OUTPUT_HANDLER_CONT (integer)
PHP_OUTPUT_HANDLER_END (integer)
E_ERROR (integer)
E_WARNING (integer)
E_PARSE (integer)
E_NOTICE (integer)
E_CORE_ERROR (integer)
E_CORE_WARNING (integer)
E_COMPILE_ERROR (integer)
E_COMPILE_WARNING (integer)
E_USER_ERROR (integer)
E_USER_WARNING (integer)
E_USER_NOTICE (integer)
E_ALL (integer)

Standard Predefined Constants

Standard Predefined Constants -- Constants defined in PHP by default

Description

These constants are defined in PHP by default.

EXTR_OVERWRITE (integer)
EXTR_SKIP (integer)
EXTR_PREFIX_SAME (integer)
EXTR_PREFIX_ALL (integer)
EXTR_PREFIX_INVALID (integer)
EXTR_PREFIX_IF_EXISTS (integer)
EXTR_IF_EXISTS (integer)
SORT_ASC (integer)
SORT_DESC (integer)
SORT_REGULAR (integer)
SORT_NUMERIC (integer)
SORT_STRING (integer)
CASE_LOWER (integer)
CASE_UPPER (integer)
COUNT_NORMAL (integer)
COUNT_RECURSIVE (integer)
ASSERT_ACTIVE (integer)
ASSERT_CALLBACK (integer)
ASSERT_BAIL (integer)
ASSERT_WARNING (integer)
ASSERT_QUIET_EVAL (integer)
CONNECTION_ABORTED (integer)
CONNECTION_NORMAL (integer)
CONNECTION_TIMEOUT (integer)
INI_USER (integer)
INI_PERDIR (integer)
INI_SYSTEM (integer)
INI_ALL (integer)
M_E (float)
M_LOG2E (float)
M_LOG10E (float)
M_LN2 (float)
M_LN10 (float)
M_PI (float)
M_PI_2 (float)
M_PI_4 (float)
M_1_PI (float)
M_2_PI (float)
M_2_SQRTPI (float)
M_SQRT2 (float)
M_SQRT1_2 (float)
CRYPT_SALT_LENGTH (integer)
CRYPT_STD_DES (integer)
CRYPT_EXT_DES (integer)
CRYPT_MD5 (integer)
CRYPT_BLOWFISH (integer)
DIRECTORY_SEPARATOR (integer)
SEEK_SET (integer)
SEEK_CUR (integer)
SEEK_END (integer)
LOCK_SH (integer)
LOCK_EX (integer)
LOCK_UN (integer)
LOCK_NB (integer)
HTML_SPECIALCHARS (integer)
HTML_ENTITIES (integer)
ENT_COMPAT (integer)
ENT_QUOTES (integer)
ENT_NOQUOTES (integer)
INFO_GENERAL (integer)
INFO_CREDITS (integer)
INFO_CONFIGURATION (integer)
INFO_MODULES (integer)
INFO_ENVIRONMENT (integer)
INFO_VARIABLES (integer)
INFO_LICENSE (integer)
INFO_ALL (integer)
CREDITS_GROUP (integer)
CREDITS_GENERAL (integer)
CREDITS_SAPI (integer)
CREDITS_MODULES (integer)
CREDITS_DOCS (integer)
CREDITS_FULLPAGE (integer)
CREDITS_QA (integer)
CREDITS_ALL (integer)
STR_PAD_LEFT (integer)
STR_PAD_RIGHT (integer)
STR_PAD_BOTH (integer)
PATHINFO_DIRNAME (integer)
PATHINFO_BASENAME (integer)
PATHINFO_EXTENSION (integer)
CHAR_MAX (integer)
LC_CTYPE (integer)
LC_NUMERIC (integer)
LC_TIME (integer)
LC_COLLATE (integer)
LC_MONETARY (integer)
LC_ALL (integer)
LC_MESSAGES (integer)
ABDAY_1 (integer)
ABDAY_2 (integer)
ABDAY_3 (integer)
ABDAY_4 (integer)
ABDAY_5 (integer)
ABDAY_6 (integer)
ABDAY_7 (integer)
DAY_1 (integer)
DAY_2 (integer)
DAY_3 (integer)
DAY_4 (integer)
DAY_5 (integer)
DAY_6 (integer)
DAY_7 (integer)
ABMON_1 (integer)
ABMON_2 (integer)
ABMON_3 (integer)
ABMON_4 (integer)
ABMON_5 (integer)
ABMON_6 (integer)
ABMON_7 (integer)
ABMON_8 (integer)
ABMON_9 (integer)
ABMON_10 (integer)
ABMON_11 (integer)
ABMON_12 (integer)
MON_1 (integer)
MON_2 (integer)
MON_3 (integer)
MON_4 (integer)
MON_5 (integer)
MON_6 (integer)
MON_7 (integer)
MON_8 (integer)
MON_9 (integer)
MON_10 (integer)
MON_11 (integer)
MON_12 (integer)
AM_STR (integer)
PM_STR (integer)
D_T_FMT (integer)
D_FMT (integer)
T_FMT (integer)
T_FMT_AMPM (integer)
ERA (integer)
ERA_YEAR (integer)
ERA_D_T_FMT (integer)
ERA_D_FMT (integer)
ERA_T_FMT (integer)
ALT_DIGITS (integer)
INT_CURR_SYMBOL (integer)
CURRENCY_SYMBOL (integer)
CRNCYSTR (integer)
MON_DECIMAL_POINT (integer)
MON_THOUSANDS_SEP (integer)
MON_GROUPING (integer)
POSITIVE_SIGN (integer)
NEGATIVE_SIGN (integer)
INT_FRAC_DIGITS (integer)
FRAC_DIGITS (integer)
P_CS_PRECEDES (integer)
P_SEP_BY_SPACE (integer)
N_CS_PRECEDES (integer)
N_SEP_BY_SPACE (integer)
P_SIGN_POSN (integer)
N_SIGN_POSN (integer)
DECIMAL_POINT (integer)
RADIXCHAR (integer)
THOUSANDS_SEP (integer)
THOUSEP (integer)
GROUPING (integer)
YESEXPR (integer)
NOEXPR (integer)
YESSTR (integer)
NOSTR (integer)
CODESET (integer)
LOG_EMERG (integer)
LOG_ALERT (integer)
LOG_CRIT (integer)
LOG_ERR (integer)
LOG_WARNING (integer)
LOG_NOTICE (integer)
LOG_INFO (integer)
LOG_DEBUG (integer)
LOG_KERN (integer)
LOG_USER (integer)
LOG_MAIL (integer)
LOG_DAEMON (integer)
LOG_AUTH (integer)
LOG_SYSLOG (integer)
LOG_LPR (integer)
LOG_NEWS (integer)
LOG_UUCP (integer)
LOG_CRON (integer)
LOG_AUTHPRIV (integer)
LOG_LOCAL0 (integer)
LOG_LOCAL1 (integer)
LOG_LOCAL2 (integer)
LOG_LOCAL3 (integer)
LOG_LOCAL4 (integer)
LOG_LOCAL5 (integer)
LOG_LOCAL6 (integer)
LOG_LOCAL7 (integer)
LOG_PID (integer)
LOG_CONS (integer)
LOG_ODELAY (integer)
LOG_NDELAY (integer)
LOG_NOWAIT (integer)
LOG_PERROR (integer)

Appendix H. List of Resource Types

The following is a list of functions which create, use or destroy PHP resources. The function is_resource() can be used to determine if a variable is a resource and get_resource_type() will return the type of resource it is.

Table H-1. Resource Types

Resource Type Name	Created By	Used By	Destroyed By	Definition
aspell	aspell_new()	aspell_check(), aspell_check_raw(), aspell_suggest()	None	Aspell dictionary
bzip2	bzopen()	bzerrno(), bzerror(), bzerrstr(), bzflush(), bzread(), bzwrite()	bzclose()	Bzip2 file
COM	com_load()	com_invoke(), com_propget(), com_get(), com_propput(), com_set(), com_propput()	None	COM object reference
VARIANT
cpdf	cpdf_open()	cpdf_page_init(), cpdf_finalize_page(), cpdf_finalize(), cpdf_output_buffer(), cpdf_save_to_file(), cpdf_set_current_page(), cpdf_begin_text(), cpdf_end_text(), cpdf_show(), cpdf_show_xy(), cpdf_text(), cpdf_set_font(), cpdf_set_leading(), cpdf_set_text_rendering(), cpdf_set_horiz_scaling(), cpdf_set_text_rise(), cpdf_set_text_matrix(), cpdf_set_text_pos(), cpdf_set_text_pos(), cpdf_set_word_spacing(), cpdf_continue_text(), cpdf_stringwidth(), cpdf_save(), cpdf_translate(), cpdf_restore(), cpdf_scale(), cpdf_rotate(), cpdf_setflat(), cpdf_setlinejoin(), cpdf_setlinecap(), cpdf_setmiterlimit(), cpdf_setlinewidth(), cpdf_setdash(), cpdf_moveto(), cpdf_rmoveto(), cpdf_curveto(), cpdf_lineto(), cpdf_rlineto(), cpdf_circle(), cpdf_arc(), cpdf_rect(), cpdf_closepath(), cpdf_stroke(), cpdf_closepath_fill_stroke(), cpdf_fill_stroke(), cpdf_clip(), cpdf_fill(), cpdf_setgray_fill(), cpdf_setgray_stroke(), cpdf_setgray(), cpdf_setrgbcolor_fill(), cpdf_setrgbcolor_stroke(), cpdf_setrgbcolor(), cpdf_add_outline(), cpdf_set_page_animation(), cpdf_import_jpeg(), cpdf_place_inline_image(), cpdf_add_annotation()	cpdf_close()	PDF document with CPDF lib
cpdf outline
curl	curl_init()	curl_init(), curl_exec()	curl_close()	Curl session
dbm	dbmopen()	dbmexists(), dbmfetch(), dbminsert(), dbmreplace(), dbmdelete(), dbmfirstkey(), dbmnextkey()	dbmclose()	Link to DBM database
dba	dba_open()	dba_delete(), dba_exists(), dba_fetch(), dba_firstkey(), dba_insert(), dba_nextkey(), dba_optimize(), dba_replace(), dba_sync()	dba_close()	Link to DBA database
dba persistent	dba_popen()	dba_delete(), dba_exists(), dba_fetch(), dba_firstkey(), dba_insert(), dba_nextkey(), dba_optimize(), dba_replace(), dba_sync()	None	Persistent link to DBA database
dbase	dbase_open()	dbase_pack(), dbase_add_record(), dbase_replace_record(), dbase_delete_record(), dbase_get_record(), dbase_get_record_with_names(), dbase_numfields(), dbase_numrecords()	dbase_close()	Link to Dbase database
dbx_link_object	dbx_connect()	dbx_query()	dbx_close()	dbx connection
dbx_result_object	dbx_query()	()	None	dbx result
domxml attribute
domxml document
domxml node
xpath context
xpath object
fbsql database	fbsql_select_db()	()	None	fbsql database
fbsql link	fbsql_change_user(), fbsql_connect()	fbsql_autocommit(), fbsql_change_user(), fbsql_create_db(), fbsql_data_seek(), fbsql_db_query(), fbsql_drop_db(), (), fbsql_select_db(), fbsql_errno(), fbsql_error(), fbsql_insert_id(), fbsql_list_dbs()	fbsql_close()	Link to fbsql database
fbsql plink	fbsql_change_user(), fbsql_pconnect()	fbsql_autocommit(), fbsql_change_user(), fbsql_create_db(), fbsql_data_seek(), fbsql_db_query(), fbsql_drop_db(), (), fbsql_select_db(), fbsql_errno(), fbsql_error(), fbsql_insert_id(), fbsql_list_dbs()	None	Persistent link to fbsql database
fbsql result	fbsql_db_query(), fbsql_list_dbs(), fbsql_query(), fbsql_list_fields(), fbsql_list_tables(), fbsql_tablename()	fbsql_affected_rows(), fbsql_fetch_array(), fbsql_fetch_assoc(), fbsql_fetch_field(), fbsql_fetch_lengths(), fbsql_fetch_object(), fbsql_fetch_row(), fbsql_field_flags(), fbsql_field_name(), fbsql_field_len(), fbsql_field_seek(), fbsql_field_table(), fbsql_field_type(), fbsql_next_result(), fbsql_num_fields(), fbsql_num_rows(), fbsql_result(), fbsql_num_rows()	fbsql_free_result()	fbsql result
fdf	fdf_open()	fdf_create(), fdf_save(), fdf_get_value(), fdf_set_value(), fdf_next_field_name(), fdf_set_ap(), fdf_set_status(), fdf_get_status(), fdf_set_file(), fdf_get_file(), fdf_set_flags(), fdf_set_opt(), fdf_set_submit_form_action(), fdf_set_javascript_action()	fdf_close()	FDF File
ftp	ftp_connect()	ftp_login(), ftp_pwd(), ftp_cdup(), ftp_chdir(), ftp_mkdir(), ftp_rmdir(), ftp_nlist(), ftp_rawlist(), ftp_systype(), ftp_pasv(), ftp_get(), ftp_fget(), ftp_put(), ftp_fput(), ftp_size(), ftp_mdtm(), ftp_rename(), ftp_delete(), ftp_site()	ftp_quit()	FTP stream
gd	imagecreate(), imagecreatefromgif(), imagecreatefromjpeg(), imagecreatefrompng(), imagecreatefromwbmp(), imagecreatefromstring(), imagecreatetruecolor()	imagearc(), imagechar(), imagecharup(), imagecolorallocate(), imagecolorat(), imagecolorclosest(), imagecolorexact(), imagecolorresolve(), imagegammacorrect(), imagegammacorrect(), imagecolorset(), imagecolorsforindex(), imagecolorstotal(), imagecolortransparent(), imagecopy(), imagecopyresized(), imagedashedline(), imagefill(), imagefilledpolygon(), imagefilledrectangle(), imagefilltoborder(), imagegif(), imagepng(), imagejpeg(), imagewbmp(), imageinterlace(), imageline(), imagepolygon(), imagepstext(), imagerectangle(), imagesetpixel(), imagestring(), imagestringup(), imagesx(), imagesy(), imagettftext(), imagefilledarc(), imageellipse(), imagefilledellipse(), imagecolorclosestalpha(), imagecolorexactalpha(), imagecolorresolvealpha(), imagecopymerge(), imagecopymergegray(), imagecopyresampled(), imagetruecolortopalette(), imagesetbrush(), imagesettile(), imagesetthickness()	imagedestroy()	GD Image
gd font	imageloadfont()	imagechar(), imagecharup(), imagefontheight()	None	Font for GD
gd PS encoding
gd PS font	imagepsloadfont()	imagepstext(), imagepsslantfont(), imagepsextendfont(), imagepsencodefont(), imagepsbbox()	imagepsfreefont()	PS font for GD
GMP integer	gmp_init()	gmp_intval(), gmp_strval(), gmp_add(), gmp_sub(), gmp_mul(), gmp_div_q(), gmp_div_r(), gmp_div_qr(), gmp_div(), gmp_mod(), gmp_divexact(), gmp_cmp(), gmp_neg(), gmp_abs(), gmp_sign(), gmp_fact(), gmp_sqrt(), gmp_sqrtrm(), gmp_perfect_square(), gmp_pow(), gmp_powm(), gmp_prob_prime(), gmp_gcd(), gmp_gcdext(), gmp_invert(), gmp_legendre(), gmp_jacobi(), gmp_random(), gmp_and(), gmp_or(), gmp_xor(), gmp_setbit(), gmp_clrbit(), gmp_scan0(), gmp_scan1(), gmp_popcount(), gmp_hamdist()	None	GMP Number
hyperwave document	hw_cp(), hw_docbyanchor(), hw_getremote(), hw_getremotechildren()	hw_children(), hw_childrenobj(), hw_getparents(), hw_getparentsobj(), hw_getchildcoll(), hw_getchildcollobj(), hw_getremote(), hw_getsrcbydestobj(), hw_getandlock(), hw_gettext(), hw_getobjectbyquerycoll(), hw_getobjectbyquerycollobj(), hw_getchilddoccoll(), hw_getchilddoccollobj(), hw_getanchors(), hw_getanchorsobj(), hw_inscoll(), hw_pipedocument(), hw_unlock()	hw_deleteobject()	Hyperwave object
hyperwave link	hw_connect()	hw_children(), hw_childrenobj(), hw_cp(), hw_deleteobject(), hw_docbyanchor(), hw_docbyanchorobj(), hw_errormsg(), hw_edittext(), hw_error(), hw_getparents(), hw_getparentsobj(), hw_getchildcoll(), hw_getchildcollobj(), hw_getremote(), hw_getremotechildren(), hw_getsrcbydestobj(), hw_getobject(), hw_getandlock(), hw_gettext(), hw_getobjectbyquery(), hw_getobjectbyqueryobj(), hw_getobjectbyquerycoll(), hw_getobjectbyquerycollobj(), hw_getchilddoccoll(), hw_getchilddoccollobj(), hw_getanchors(), hw_getanchorsobj(), hw_mv(), hw_incollections(), hw_info(), hw_inscoll(), hw_insdoc(), hw_insertdocument(), hw_insertobject(), hw_mapid(), hw_modifyobject(), hw_pipedocument(), hw_unlock(), hw_who(), hw_getusername()	hw_close(), hw_free_document()	Link to Hyperwave server
hyperwave link persistent	hw_pconnect()	hw_children(), hw_childrenobj(), hw_cp(), hw_deleteobject(), hw_docbyanchor(), hw_docbyanchorobj(), hw_errormsg(), hw_edittext(), hw_error(), hw_getparents(), hw_getparentsobj(), hw_getchildcoll(), hw_getchildcollobj(), hw_getremote(), hw_getremotechildren(), hw_getsrcbydestobj(), hw_getobject(), hw_getandlock(), hw_gettext(), hw_getobjectbyquery(), hw_getobjectbyqueryobj(), hw_getobjectbyquerycoll(), hw_getobjectbyquerycollobj(), hw_getchilddoccoll(), hw_getchilddoccollobj(), hw_getanchors(), hw_getanchorsobj(), hw_mv(), hw_incollections(), hw_info(), hw_inscoll(), hw_insdoc(), hw_insertdocument(), hw_insertobject(), hw_mapid(), hw_modifyobject(), hw_pipedocument(), hw_unlock(), hw_who(), hw_getusername()	None	Persistent link to Hyperwave server
icap	icap_open()	icap_fetch_event(), icap_list_events(), icap_store_event(), icap_snooze(), icap_list_alarms(), icap_delete_event()	icap_close()	Link to icap server
imap	imap_open()	imap_append(), imap_body(), imap_check(), imap_createmailbox(), imap_delete(), imap_deletemailbox(), imap_expunge(), imap_fetchbody(), imap_fetchstructure(), imap_headerinfo(), imap_header(), imap_headers(), imap_listmailbox(), imap_getmailboxes(), imap_get_quota(), imap_status(), imap_listsubscribed(), imap_set_quota(), imap_set_quota(), imap_getsubscribed(), imap_mail_copy(), imap_mail_move(), imap_num_msg(), imap_num_recent(), imap_ping(), imap_renamemailbox(), imap_reopen(), imap_subscribe(), imap_undelete(), imap_unsubscribe(), imap_scanmailbox(), imap_mailboxmsginfo(), imap_fetchheader(), imap_uid(), imap_msgno(), imap_search(), imap_fetch_overview()	imap_close()	Link to IMAP, POP3 server
imap chain persistent
imap persistent
ingres	ingres_connect()	ingres_query(), ingres_num_rows(), ingres_num_fields(), ingres_field_name(), ingres_field_type(), ingres_field_nullable(), ingres_field_length(), ingres_field_precision(), ingres_field_scale(), ingres_fetch_array(), ingres_fetch_row(), ingres_fetch_object(), ingres_rollback(), ingres_commit(), ingres_autocommit()	ingres_close()	Link to ingresII base
ingres persistent	ingres_pconnect()	ingres_query(), ingres_num_rows(), ingres_num_fields(), ingres_field_name(), ingres_field_type(), ingres_field_nullable(), ingres_field_length(), ingres_field_precision(), ingres_field_scale(), ingres_fetch_array(), ingres_fetch_row(), ingres_fetch_object(), ingres_rollback(), ingres_commit(), ingres_autocommit()	None	Persistent link to ingresII base
interbase blob
interbase link	ibase_connect()	ibase_query(), ibase_prepare(), ibase_trans()	ibase_close()	Link to Interbase database
interbase link persistent	ibase_pconnect()	ibase_query(), ibase_prepare(), ibase_trans()	None	Persistent link to Interbase database
interbase query	ibase_prepare()	ibase_execute()	ibase_free_query()	Interbase query
interbase result	ibase_query()	ibase_fetch_row(), ibase_fetch_object(), ibase_field_info(), ibase_num_fields()	ibase_free_result()	Interbase Result
interbase transaction	ibase_trans()	ibase_commit()	ibase_rollback()	Interbase transaction
java
ldap link	ldap_connect(), ldap_search()	ldap_count_entries(), ldap_first_attribute(), ldap_first_entry(), ldap_get_attributes(), ldap_get_dn(), ldap_get_entries(), ldap_get_values(), ldap_get_values_len(), ldap_next_attribute(), ldap_next_entry()	ldap_close()	ldap connection
ldap result	ldap_read()	ldap_add(), ldap_compare(), ldap_bind(), ldap_count_entries(), ldap_delete(), ldap_errno(), ldap_error(), ldap_first_attribute(), ldap_first_entry(), ldap_get_attributes(), ldap_get_dn(), ldap_get_entries(), ldap_get_values(), ldap_get_values_len(), ldap_get_option(), ldap_list(), ldap_modify(), ldap_mod_add(), ldap_mod_replace(), ldap_next_attribute(), ldap_next_entry(), ldap_mod_del(), ldap_set_option(), ldap_unbind()	ldap_free_result()	ldap search result
ldap result entry
mcal	mcal_open(), mcal_popen()	mcal_create_calendar(), mcal_rename_calendar(), mcal_rename_calendar(), mcal_delete_calendar(), mcal_fetch_event(), mcal_list_events(), mcal_append_event(), mcal_store_event(), mcal_delete_event(), mcal_list_alarms(), mcal_event_init(), mcal_event_set_category(), mcal_event_set_title(), mcal_event_set_description(), mcal_event_set_start(), mcal_event_set_end(), mcal_event_set_alarm(), mcal_event_set_class(), mcal_next_recurrence(), mcal_event_set_recur_none(), mcal_event_set_recur_daily(), mcal_event_set_recur_weekly(), mcal_event_set_recur_monthly_mday(), mcal_event_set_recur_monthly_wday(), mcal_event_set_recur_yearly(), mcal_fetch_current_stream_event(), mcal_event_add_attribute(), mcal_expunge()	mcal_close()	Link to calendar server
SWFAction
SWFBitmap
SWFButton
SWFDisplayItem
SWFFill
SWFFont
SWFGradient
SWFMorph
SWFMovie
SWFShape
SWFSprite
SWFText
SWFTextField
mnogosearch agent
mnogosearch result
msql link	msql_connect()	msql(), msql_create_db(), msql_createdb(), msql_drop_db(), msql_drop_db(), msql_select_db(), msql_select_db()	msql_close()	Link to mSQL database
msql link persistent	msql_pconnect()	msql(), msql_create_db(), msql_createdb(), msql_drop_db(), msql_drop_db(), msql_select_db(), msql_select_db()	None	Persistent link to mSQL
msql query	msql_query()	msql(), msql_affected_rows(), msql_data_seek(), msql_dbname(), msql_fetch_array(), msql_fetch_field(), msql_fetch_object(), msql_fetch_row(), msql_fieldname(), msql_field_seek(), msql_fieldtable(), msql_fieldtype(), msql_fieldflags(), msql_fieldlen(), msql_num_fields(), msql_num_rows(), msql_numfields(), msql_numrows(), msql_result()	msql_free_result(), msql_free_result()	mSQL result
mssql link	mssql_connect()	mssql_query(), mssql_select_db()	mssql_close()	Link to Microsft SQL Server database
mssql link persistent	mssql_pconnect()	mssql_query(), mssql_select_db()	None	Persistent link to Microsft SQL Server
mssql result	mssql_query()	mssql_data_seek(), mssql_fetch_array(), mssql_fetch_field(), mssql_fetch_object(), mssql_fetch_row(), mssql_field_length(), mssql_field_name(), mssql_field_seek(), mssql_field_type(), mssql_num_fields(), mssql_num_rows(), mssql_result()	mssql_free_result()	Microsft SQL Server result
mysql link	mysql_connect()	mysql_affected_rows(), mysql_change_user(), mysql_create_db(), mysql_data_seek(), mysql_db_name(), mysql_db_query(), mysql_drop_db(), mysql_errno(), mysql_error(), mysql_insert_id(), mysql_list_dbs(), mysql_list_fields(), mysql_list_tables(), mysql_query(), mysql_result(), mysql_select_db(), mysql_tablename(), mysql_get_host_info(), mysql_get_proto_info(), mysql_get_server_info()	mysql_close()	Link to MySQL database
mysql link persistent	mysql_pconnect()	mysql_affected_rows(), mysql_change_user(), mysql_create_db(), mysql_data_seek(), mysql_db_name(), mysql_db_query(), mysql_drop_db(), mysql_errno(), mysql_error(), mysql_insert_id(), mysql_list_dbs(), mysql_list_fields(), mysql_list_tables(), mysql_query(), mysql_result(), mysql_select_db(), mysql_tablename(), mysql_get_host_info(), mysql_get_proto_info(), mysql_get_server_info()	None	Persistent link to MySQL database
mysql result	mysql_db_query(), mysql_list_dbs(), mysql_list_fields(), mysql_list_tables(), mysql_query()	mysql_data_seek(), mysql_db_name(), mysql_fetch_array(), mysql_fetch_assoc(), mysql_fetch_field(), mysql_fetch_lengths(), mysql_fetch_object(), mysql_fetch_row(), mysql_fetch_row(), mysql_field_flags(), mysql_field_name(), mysql_field_len(), mysql_field_seek(), mysql_field_table(), mysql_field_type(), mysql_num_fields(), mysql_num_rows(), mysql_result(), mysql_tablename()	mysql_free_result()	MySQL result
oci8 collection
oci8 connection	ocilogon(), ociplogon(), ocinlogon()	ocicommit(), ociserverversion(), ocinewcursor(), ociparse(), ocierror()	ocilogoff()	Link to Oracle database
oci8 descriptor
oci8 server
oci8 session
oci8 statement	ocinewdescriptor()	ocirollback(), ocinewdescriptor(), ocirowcount(), ocidefinebyname(), ocibindbyname(), ociexecute(), ocinumcols(), ociresult(), ocifetch(), ocifetchinto(), ocifetchstatement(), ocicolumnisnull(), ocicolumnname(), ocicolumnsize(), ocicolumntype(), ocistatementtype(), ocierror()	ocifreestatement()	Oracle Cursor
odbc link	odbc_connect()	odbc_autocommit(), odbc_commit(), odbc_error(), odbc_errormsg(), odbc_exec(), odbc_tables(), odbc_tableprivileges(), odbc_do(), odbc_prepare(), odbc_columns(), odbc_columnprivileges(), odbc_procedurecolumns(), odbc_specialcolumns(), odbc_rollback(), odbc_setoption(), odbc_gettypeinfo(), odbc_primarykeys(), odbc_foreignkeys(), odbc_procedures(), odbc_statistics()	odbc_close()	Link to ODBC database
odbc link persistent	odbc_connect()	odbc_autocommit(), odbc_commit(), odbc_error(), odbc_errormsg(), odbc_exec(), odbc_tables(), odbc_tableprivileges(), odbc_do(), odbc_prepare(), odbc_columns(), odbc_columnprivileges(), odbc_procedurecolumns(), odbc_specialcolumns(), odbc_rollback(), odbc_setoption(), odbc_gettypeinfo(), odbc_primarykeys(), odbc_foreignkeys(), odbc_procedures(), odbc_statistics()	None	Persistent link to ODBC database
odbc result	odbc_prepare()	odbc_binmode(), odbc_cursor(), odbc_execute(), odbc_fetch_into(), odbc_fetch_row(), odbc_field_name(), odbc_field_num(), odbc_field_type(), odbc_field_len(), odbc_field_precision(), odbc_field_scale(), odbc_longreadlen(), odbc_num_fields(), odbc_num_rows(), odbc_result(), odbc_result_all(), odbc_setoption()	odbc_free_result()	ODBC result
birdstep link
birdstep result
OpenSSL key	openssl_get_privatekey(), openssl_get_publickey()	openssl_sign(), openssl_seal(), openssl_open(), openssl_verify()	openssl_free_key()	OpenSSL key
OpenSSL X.509	openssl_x509_read()	openssl_x509_parse(), openssl_x509_checkpurpose()	openssl_x509_free()	Public Key
oracle Cursor	ora_open()	ora_bind(), ora_columnname(), ora_columnsize(), ora_columntype(), ora_error(), ora_errorcode(), ora_exec(), ora_fetch(), ora_fetch_into(), ora_getcolumn(), ora_numcols(), ora_numrows(), ora_parse()	ora_close()	Oracle cursor
oracle link	ora_logon()	ora_do(), ora_error(), ora_errorcode(), ora_rollback(), ora_commitoff(), ora_commiton(), ora_open(), ora_commit()	ora_logoff()	Link to oracle database
oracle link persistent	ora_plogon()	ora_do(), ora_error(), ora_errorcode(), ora_rollback(), ora_commitoff(), ora_commiton(), ora_open(), ora_commit()	None	Persistent link to oracle database
pdf document	pdf_new()	pdf_add_bookmark(), pdf_add_launchlink(), pdf_add_locallink(), pdf_add_note(), pdf_add_pdflink(), pdf_add_weblink(), pdf_arc(), pdf_attach_file(), pdf_begin_page(), pdf_circle(), pdf_clip(), pdf_closepath(), pdf_closepath_fill_stroke(), pdf_closepath_stroke(), pdf_concat(), pdf_continue_text(), pdf_curveto(), pdf_end_page(), pdf_endpath(), pdf_fill(), pdf_fill_stroke(), pdf_findfont(), pdf_get_buffer(), pdf_get_image_height(), pdf_get_image_width(), pdf_get_parameter(), pdf_get_value(), pdf_lineto(), pdf_moveto(), pdf_open_ccitt(), pdf_open_file(), pdf_open_image_file(), pdf_place_image(), pdf_rect(), pdf_restore(), pdf_rotate(), pdf_save(), pdf_scale(), pdf_setdash(), pdf_setflat(), pdf_setfont(), pdf_setgray(), pdf_setgray_fill(), pdf_setgray_stroke(), pdf_setlinecap(), pdf_setlinejoin(), pdf_setlinewidth(), pdf_setmiterlimit(), pdf_setpolydash(), pdf_setrgbcolor(), pdf_setrgbcolor_fill(), pdf_setrgbcolor_stroke(), pdf_set_border_color(), pdf_set_border_dash(), pdf_set_border_style(), pdf_set_char_spacing(), pdf_set_duration(), pdf_set_font(), pdf_set_horiz_scaling(), pdf_set_parameter(), pdf_set_text_pos(), pdf_set_text_rendering(), pdf_set_value(), pdf_set_word_spacing(), pdf_show(), pdf_show_boxed(), pdf_show_xy(), pdf_skew(), pdf_stringwidth(), pdf_stroke(), pdf_translate(), pdf_open_memory_image()	pdf_close(), pdf_delete()	PDF document
pdf image	pdf_open_image(), pdf_open_image_file(), pdf_open_memory_image()	pdf_get_image_height(), pdf_get_image_width(), pdf_open_CCITT(), pdf_place_image()	pdf_close_image()	Image in PDF file
pdf object
pdf outline
pgsql large object	pg_lo_open()	pg_lo_open(), pg_lo_create(), pg_lo_read(), pg_lo_read_all(), pg_lo_seek(), pg_lo_tell(), pg_lo_unlink(), pg_lo_write()	pg_lo_close()	PostgreSQL Large Object
pgsql link	pg_connect()	pg_affected_rows(), pg_query(), pg_send_query(), pg_get_result(), pg_connection_busy(), pg_connection_reset(), pg_connection_status(), pg_last_error(), pg_last_notice(), pg_lo_create(), pg_lo_export(), pg_lo_import(), pg_lo_open(), pg_lo_unlink(), pg_host(), pg_port(), pg_dbname(), pg_options(), pg_copy_from(), pg_copy_to(), pg_end_copy(), pg_put_line(), pg_tty(), pg_trace(), pg_untrace(), pg_set_client_encoding(), pg_client_encoding(), pg_metadata(), pg_convert(), pg_insert(), pg_select(), pg_delete(), pg_update()	pg_close()	Link to PostgreSQL database
pgsql link persistent	pg_pconnect()	pg_affected_rows(), pg_query(), pg_send_query(), pg_get_result(), pg_connection_busy(), pg_connection_reset(), pg_connection_status(), pg_last_error(), pg_last_notice(), pg_lo_create(), pg_lo_export(), pg_lo_import(), pg_lo_open(), pg_lo_unlink(), pg_host(), pg_port(), pg_dbname(), pg_options(), pg_copy_from(), pg_copy_to(), pg_end_copy(), pg_put_line(), pg_tty(), pg_trace(), pg_untrace(), pg_set_client_encoding(), pg_client_encoding(), pg_metadata(), pg_convert(), pg_insert(), pg_select(), pg_delete(), pg_update()	None	Persistent link to PostgreSQL database
pgsql result	pg_query(), pg_get_result()	pg_fetch_array(), pg_fetch_object(), pg_fetch_result(), pg_fetch_row(), pg_field_is_null(), pg_field_name(), pg_field_num(), pg_field_prtlen(), pg_field_size(), pg_field_type(), pg_last_oid(), pg_num_fields(), pg_num_rows(), pg_result_error(), pg_result_status()	pg_free_result()	PostgreSQL result
pgsql string
printer
printer brush
printer font
printer pen
pspell	pspell_new(), pspell_new_config(), pspell_new_personal()	pspell_add_to_personal(), pspell_add_to_session(), pspell_check(), pspell_clear_session(), pspell_config_ignore(), pspell_config_mode(), pspell_config_personal(), pspell_config_repl(), pspell_config_runtogether(), pspell_config_save_repl(), pspell_save_wordlist(), pspell_store_replacement(), pspell_suggest()	None	pspell dictionary
pspell config	pspell_config_create()	pspell_new_config()	None	pspell configuration
Sablotron XSLT	xslt_create()	xslt_closelog(), xslt_openlog(), xslt_run(), xslt_set_sax_handler(), xslt_errno(), xslt_error(), xslt_fetch_result(), xslt_free()	xslt_free()	XSLT parser
shmop	shmop_open()	shmop_read(), shmop_write(), shmop_size(), shmop_delete()	shmop_close()
sockets file descriptor set	socket()	accept_connect(), bind(), connect(), listen(), read(), write()	close()	Socket
sockets i/o vector
dir	dir()	readdir(), rewinddir()	closedir()	Dir handle
file	fopen()	feof(), fflush(), fgetc(), fgetcsv(), fgets(), fgetss(), flock(), fpassthru(), fputs(), fwrite(), fread(), fseek(), ftell(), fstat(), ftruncate(), set_file_buffer(), rewind()	fclose()	File handle
pipe	popen()	feof(), fflush(), fgetc(), fgetcsv(), fgets(), fgetss(), fpassthru(), fputs(), fwrite(), fread()	pclose()	Process handle
socket	fsockopen()	fflush(), fgetc(), fgetcsv(), fgets(), fgetss(), fpassthru(), fputs(), fwrite(), fread()	fclose()	Socket handle
stream
sybase-db link	sybase_connect()	sybase_query(), sybase_select_db()	sybase_close()	Link to Sybase database using DB library
sybase-db link persistent	sybase_pconnect()	sybase_query(), sybase_select_db()	None	Persistent link to Sybase database using DB library
sybase-db result	sybase_query()	sybase_data_seek(), sybase_fetch_array(), sybase_fetch_field(), sybase_fetch_object(), sybase_fetch_row(), sybase_field_seek(), sybase_num_fields(), sybase_num_rows(), sybase_result()	sybase_free_result()	Sybase result using DB library
sybase-ct link	sybase_connect()	sybase_affected_rows(), sybase_query(), sybase_select_db()	sybase_close()	Link to Sybase database using CT library
sybase-ct link persistent	sybase_pconnect()	sybase_affected_rows(), sybase_query(), sybase_select_db()	None	Persistent link to Sybase database using CT library
sybase-ct result	sybase_query()	sybase_data_seek(), sybase_fetch_array(), sybase_fetch_field(), sybase_fetch_object(), sybase_fetch_row(), sybase_field_seek(), sybase_num_fields(), sybase_num_rows(), sybase_result()	sybase_free_result()	Sybase result using CT library
sysvsem	sem_get()	sem_acquire()	sem_release()	System V Semaphore
sysvshm	shm_attach()	shm_remove(), shm_put_var(), shm_get_var(), shm_remove_var()	shm_detach()	System V Shared Memory
wddx	wddx_packet_start()	wddx_add_vars()	wddx_packet_end()	WDDX packet
xml	xml_parser_create()	xml_set_object(), xml_set_element_handler(), xml_set_character_data_handler(), xml_set_processing_instruction_handler(), xml_set_default_handler(), xml_set_unparsed_entity_decl_handler(), xml_set_notation_decl_handler(), xml_set_external_entity_ref_handler(), xml_parse(), xml_get_error_code(), xml_error_string(), xml_get_current_line_number(), xml_get_current_column_number(), xml_get_current_byte_index(), xml_parse_into_struct(), xml_parser_set_option(), xml_parser_get_option()	xml_parser_free()	XML parser
zlib	gzopen()	gzeof(), gzgetc(), gzgets(), gzgetss(), gzpassthru(), gzputs(), gzread(), gzrewind(), gzseek(), gztell(), gzwrite()	gzclose()	gz-compressed file

Appendix I. List of Supported Protocols/Wrappers

The following is a list of the various URL style protocols that PHP has built-in for use with the filesystem functions such as fopen() and copy(). In addition to these wrappers, as of PHP 4.3, you can write your own wrappers using PHP script and stream_register_wrapper().

HTTP and HTTPS

PHP 3, PHP 4. https:// since PHP 4.3

http://example.com
http://user:password@example.com
https://example.com
https://user:password@example.com

Allows read-only access to files/resources via HTTP 1.0, using the HTTP GET method. A Host: header is sent with the request to handle name-based virtual hosts. If you have configured a user_agent string using your ini file or the stream context, it will also be included in the request.

Redirects have been supported since PHP 4.0.5; if you are using an earlier version you will need to include trailing slashes in your URLs.

The stream allows access to the body of the resource; the headers are stored in the $http_response_header variable. Since PHP 4.3, the headers are available using stream_get_meta_data().

HTTP connections are read-only; you cannot write data or copy files to an HTTP resource.

Note: HTTPS is supported starting from PHP 4.3, if you have compiled in support for OpenSSL.

FTP and FTPS

PHP 3, PHP 4. ftps:// since PHP 4.3

ftp://example.com/pub/file.txt
ftp://user:password@example.com/pub/file.txt
ftps://example.com/pub/file.txt
ftps://user:password@example.com/pub/file.txt

Allows read access to existing files and creation of new files via FTP. If the server does not support passive mode ftp, the connection will fail.

You can open files for either reading or writing, but not both simultaneously. If the remote file already exists on the ftp server and you attempt to open it for writing, the connection will fail. If you need to update existing files over ftp, use ftp_connect().

ftps:// was introduced in PHP 4.3. It is the same as ftp://, but attempts to negotiate a secure connection with the ftp server. If the server does not support SSL, then the connection falls back to regular unencrypted ftp.

Note: FTPS is supported starting from PHP 4.3, if you have compiled in support for OpenSSL.

PHP input/output streams

PHP 3.0.13 and up, php://output since PHP 4.3

php://stdin
php://stdout
php://stderr
php://output

php://stdin, php://stdout and php://stderr allow access to the corresponding input or output stream of the PHP process.

php://output allows you to write to the output buffer mechanism in the same way as print() and echo().

php://stdin is read-only, whereas php://stdout, php://stderr and php://output are write-only.

Compression Streams

zlib: PHP 4.0.4 - PHP 4.2.3 (systems with fopencookie only)

compress.zlib:// and compress.bzip2:// PHP 4.3 and up

zlib:
compress.zlib://
compress.bzip2://

zlib: works like gzopen(), except that the stream can be used with fread() and the other filesystem functions. This is deprecated as of PHP 4.3 due to ambiguities with filenames containing ':' characters; use compress.zlib:// instead.

compress.zlib:// and compress.bzip2:// are equivalent to gzopen() and bzopen() respectively, and operate even on systems that do not support fopencookie.

Appendix J. List of Parser Tokens

Various parts of the PHP language are represented internally by types like T_SR. PHP outputs identifiers like this one in parse errors, like "Parse error: unexpected T_SR, expecting ',' or ';' in script.php on line 10."

You're supposed to know what T_SR means. For everybody who doesn't know that, here is a table with those identifiers, PHP-syntax and references to the appropriate places in the manual.

Table J-1. Tokens

Token	Syntax	Reference
T_AND_EQUAL	&=	assignment operators
T_ARRAY	array()	array(), array syntax
T_ARRAY_CAST	(array)	type-casting
T_AS	as	foreach
T_BAD_CHARACTER		anything below ASCII 32 except \t (0x09), \n (0x0a) and \r (0x0d)
T_BOOLEAN_AND	&&	logical operators
T_BOOLEAN_OR	\|\|	logical operators
T_BOOL_CAST	(bool) or (boolean)	type-casting
T_BREAK	break	break
T_CASE	case	switch
T_CHARACTER
T_CLASS	class	classes and objects
T_CLOSE_TAG	?> or %>
T_COMMENT	// or #	comments
T_CONCAT_EQUAL	.=	assignment operators
T_CONST	const
T_CONSTANT_ENCAPSED_STRING	"foo" or 'bar'	string syntax
T_CONTINUE	continue
T_CURLY_OPEN
T_DEC	--	incrementing/decrementing operators
T_DECLARE	declare	declare
T_DEFAULT	default	switch
T_DIV_EQUAL	/=	assignment operators
T_DNUMBER	0.12, etc	floating point numbers
T_DO	do	do..while
T_DOLLAR_OPEN_CURLY_BRACES	${	complex variable parsed syntax
T_DOUBLE_ARROW	=>	array syntax
T_DOUBLE_CAST	(real), (double) or (float)	type-casting
T_ECHO	echo	echo()
T_ELSE	else	else
T_ELSEIF	elseif	elseif
T_EMPTY	empty	empty()
T_ENCAPSED_AND_WHITESPACE
T_ENDDECLARE	enddeclare	declare, alternative syntax
T_ENDFOR	endfor	for, alternative syntax
T_ENDFOREACH	endforeach	foreach, alternative syntax
T_ENDIF	endif	if, alternative syntax
T_ENDSWITCH	endswitch	switch, alternative syntax
T_ENDWHILE	endwhile	while, alternative syntax
T_END_HEREDOC		heredoc syntax
T_EVAL	eval()	eval()
T_EXIT	exit or die	exit(), die()
T_EXTENDS	extends	extends, classes and objects
T_FILE	__FILE__	constants
T_FOR	for	for
T_FOREACH	foreach	foreach
T_FUNCTION	function or cfunction	functions
T_GLOBAL	global	variable scope
T_IF	if	if
T_INC	++	incrementing/decrementing operators
T_INCLUDE	include()	include()
T_INCLUDE_ONCE	include_once()	include_once()
T_INLINE_HTML
T_INT_CAST	(int) or (integer)	type-casting
T_ISSET	isset()	isset()
T_IS_EQUAL	==	comparison operators
T_IS_GREATER_OR_EQUAL	>=	comparison operators
T_IS_IDENTICAL	===	comparison operators
T_IS_NOT_EQUAL	!= or <>	comparison operators
T_IS_NOT_IDENTICAL	!==	comparison operators
T_SMALLER_OR_EQUAL	<=	comparison operators
T_LINE	__LINE__	constants
T_LIST	list()	list()
T_LNUMBER	123, 012, 0x1ac, etc	integers
T_LOGICAL_AND	and	logical operators
T_LOGICAL_OR	or	logical operators
T_LOGICAL_XOR	xor	logical operators
T_MINUS_EQUAL	-=	assignment operators
T_ML_COMMENT	/* and */	comments
T_MOD_EQUAL	%=	assignment operators
T_MUL_EQUAL	*=	assignment operators
T_NEW	new	classes and objects
T_NUM_STRING
T_OBJECT_CAST	(object)	type-casting
T_OBJECT_OPERATOR	->	classes and objects
T_OLD_FUNCTION	old_function	old_function
T_OPEN_TAG	<?php, <? or <%	escaping from HTML
T_OPEN_TAG_WITH_ECHO	<?= or <%=	escaping from HTML
T_OR_EQUAL	\|=	assignment operators
T_PAAMAYIM_NEKUDOTAYIM	::	::
T_PLUS_EQUAL	+=	assignment operators
T_PRINT	print()	print()
T_REQUIRE	require()	require()
T_REQUIRE_ONCE	require_once()	require_once()
T_RETURN	return	returning values
T_SL	<<	bitwise operators
T_SL_EQUAL	<<=	assignment operators
T_SR	>>	bitwise operators
T_SR_EQUAL	>>=	assignment operators
T_START_HEREDOC	<<<	heredoc syntax
T_STATIC	static	variable scope
T_STRING
T_STRING_CAST	(string)	type-casting
T_STRING_VARNAME
T_SWITCH	switch	switch
T_UNSET	unset()	unset()
T_UNSET_CAST	(unset)	(not documented; casts to `NULL`)
T_USE	use	(not implemented)
T_VAR	var	classes and objects
T_VARIABLE	$foo	variables
T_WHILE	while	while, do..while
T_WHITESPACE
T_XOR_EQUAL	^=	assignment operators
T_FUNC_C	__FUNCTION__	constants, since `PHP` 4.3.0
T_CLASS_C	__CLASS__	constants, since `PHP` 4.3.0

Appendix K. About the manual

Formats

The PHP manual is provided in several formats. These formats can be divided into two groups: online readable formats, and downloadable packages.

Note: Some publishers have made available printed versions of this manual. We cannot recommend any of those, as they tend to become out-of-date very quickly.

You can read the manual online at http://www.php.net/ and on the numerous mirror sites. For best performance, you should choose the mirror site closest to you. You can view the manual in either its plain (print-friendly) HTML format or an HTML format that integrates the manual into the look and feel of the PHP website itself.

An advantage of the online manual over most of the offline formats is the integration of user-contributed notes. An obvious disadvantage is that you have to be online to view the manual in the online formats.

There are several offline formats of the manual, and the most appropriate format for you depends on what operating system you use and your personal reading style. For information on how the manual is generated in so many formats, read the 'How we generate the formats' section of this appendix.

The most cross-platform formats of the manual are the HTML and plain-text versions. The HTML format is provided both as a single HTML file and as a package of individual files for each section (which results in a collection of several thousand files). The HTML and plaintext formats are provided as tar files compressed using the bzip2 archiver.

Another popular cross-platform format, and the format most suited to printing, is PDF (also known as Adobe Acrobat). But before you rush to download this format and hit the Print button, be warned that the manual is nearly 2000 pages long, and constantly being revised.

Note: If you do not already have a program capable of viewing PDF format files, you may need to download Adobe Acrobat Reader.

For owners of Palm-compatible handhelds, the Palm document and iSilo formats are ideal for this platform. You can bring your handheld with you on your daily commute and use a DOC or iSilo reader to brush up on your PHP knowledge, or just use it as a quick reference.

For Windows platforms, the Windows HTML Help version of the manual soups up the HTML format for use with the Windows HTML Help application. This version provides full-text search, a full index, and bookmarking. Many popular Windows PHP development environments also integrate with this version of the documentation to provide easy access.

About user notes

The user-contributed notes play an important role in the development of this manual. By allowing readers of the manual to contribute examples, caveats, and further clarifications from their browser, we are able to incorporate that feedback into the main text of the manual. And until the notes have been incorporated, they can be viewed in their submitted form online and in some of the offline formats.

Note: The user-contributed notes are not moderated before they appear online, so the quality of the writing or code examples, and even the veracity of the contribution, cannot be guaranteed. (Not that there is any guarantee of the quality or accuracy of the manual text itself.)

How to read a function definition (prototype)

Each function is documented for quick reference, knowing how to read and understand the manual will make using PHP much easier. Rather than relying on examples or cut/paste, you want to know how to read function definitions (prototypes). Let's begin:

Prerequisite: Basic understanding of types: Although PHP is a loosly typed language, it's important to have a basic understanding of types as they have important meaning.

Function definitions tell us what type of value is returned, let's use the definition for strlen() as our first example:

strlen (PHP 3, PHP 4 >= 4.0.0) strlen -- Get string length Description int strlen ( string str ) Returns the length of string.

Table K-1. Explanation of a function definition

Part	Description
strlen	The function name.
(PHP 3, PHP 4 >= 4.0.0)	strlen() has been around in both all of PHP 3 and PHP 4
int	Type of value this function returns, which is an integer (i.e. The length of a string is measured in numbers).
( string str )	The first (and in this case the only) parameter/argument for the function strlen() is named `str`, and it's a string.

We could rewrite the above function definition in a generic way:

returned type function name ( parameter type parameter name )

Many functions take on multiple parameters, such as in_array(). It's prototype is as follows:

bool in_array ( mixed needle, array haystack [, bool strict])

What does this mean? in_array() returns a boolean value, TRUE on success (the needle was found in the haystack) or FALSE on failure (the needle was not found in the haystack). The first parameter is named needle and it can be many different types, so we call it "mixed". This mixed needle (what we're looking for) can either be a scalar value (string, integer, or float), or an array. haystack (the array we're searching in) is the second parameter. The third optional parameter is named strict. All optional parameters are seen in [ brackets ]. The manual states that the strict parameter defaults to boolean FALSE. See the manual page on each function for details on how they work.

How to find more information about PHP

This manual does not attempt to provide instruction about general programming practices. If you are a first-time, or even just a beginning, programmer, you may find it difficult to learn how to program in PHP using just this manual. You may want to seek out a text more oriented towards beginners. You can find a list of PHP-related books at http://www.php.net/books.php.

There are a number of active mailing lists for discussion of all aspects of programming with PHP. If you find yourself stuck on a problem for which you can't find your own solution, you may be able to get help from someone on these lists. You can find a list of the mailing lists at http://www.php.net/support.php, as well as links to the mailing list archives and other online support resources. Furthermore, at http://www.php.net/links.php there is a list of websites devoted to PHP articles, forums, and code galleries.

How to help improve the documentation

There are three ways you can help to improve this documentation.

If you find errors in this manual, in any language, please report them using the bug system at http://bugs.php.net/. Classify the bug as "Documentation Problem". You can also submit problems related to specific manual formats here.

Note: Please don't abuse the bug system by submitting requests for help. Use the mailing lists or community sites mentioned earlier, instead.

By contributing notes, you can provide additional examples, caveats, and clarifications for other readers. But do not submit bug reports using the annotation system please. You can read more about annotations in the 'About user notes' section of this appendix.

If you know English and some foreign language, you may also help out in the translations. If you would like to start a new translation, or help in a translation project, please read http://cvs.php.net/co.php/phpdoc/howto/howto.html.tar.gz.

How we generate the formats

This manual is written in XML using the DocBook XML DTD, using DSSSL (Document Style and Semantics Specification Language) for formatting, and experimentally the XSLT (Extensible Stylesheet Language Transformations) for maintenance and formatting.

Using XML as a source format gives us the ability to generate many output formats from the source files, while only maintaining one source document for all formats. The tools used for formatting HTML and TeX versions are Jade, written by James Clark and The Modular DocBook Stylesheets written by Norman Walsh. We use Microsoft HTML Help Workshop to generate the Windows HTML Help format of the manual, and of course PHP itself to do some additional conversions and formatting.

You can download the manual in various languages and formats, including plain text, plain HTML, PDF, PalmPilot DOC, PalmPilot iSilo and Windows HTML Help, from http://www.php.net/docs.php. The manuals are updated automatically as the text is updated.

You can find more information about downloading the XML source code of this documentation at http://cvs.php.net/. The documentation is stored in the phpdoc module.

Translations

The PHP manual is not only available in various formats, it is also available in various languages. The text of the manual is first written in english, then teams of people across the world take care of translating it to their native language. If a translation for a specified function or chapter has not yet been made, the build system of the manual falls back to the english version of it.

Peoples involved in the translations start from the XML source code available from http://cvs.php.net/ and from it they translate to thier mother language. They do not use the HTML, the plain text, or the PDF version. It is the build system which takes care of the conversions from XML to human readable formats.

Note: If you would like to help translating the documentation to your native language, please get in touch with the translation/documentation team subscribing to the phpdoc mailinglist: send an empty mail to phpdoc-subscribe@lists.php.net. The mailing list address is phpdoc@lists.php.net. State in the message that you are interested in translating the manual to a language and someone will get back to you, helping you start a new language translation or reach the already active documentation team for your language.

At the moment the manual is available, partly or not, in the following languages: Brazilian Portuguese, Chinese, Czech, Dutch, French, German, Hungarian, Italian, Japanese, Korean, Polish and Spanish.

They all can be downloaded here: http://www.php.net/docs.php.

Adabas D	Ingres	Oracle (OCI7 and OCI8)
dBase	InterBase	Ovrimos
Empress	FrontBase	PostgreSQL
FilePro (read-only)	mSQL	Solid
Hyperwave	Direct MS-SQL	Sybase
IBM DB2	MySQL	Velocis
Informix	ODBC	Unix dbm

PHP Manual

Edited by

I. Getting Started

What is PHP?

What can PHP do?

What do I need?

Your first PHP-enabled page

Something Useful

Dealing with Forms

Using old code with new versions of PHP

What's next?

General Installation Considerations

Unix/HP-UX installs

Unix/Linux installs

Using Packages

Unix/Mac OS X installs

Using Packages

Compiling for OS X server

Compiling for MacOS X client

Unix/OpenBSD installs

Using Ports

Using Packages

Unix/Solaris installs

Required software

Using Packages

Installation on UNIX systems

Apache Module Quick Reference

Building

Installation on Windows systems

Windows InstallShield

Manual Installation Steps

Building from source

Preparations

Putting it all together

Compiling

Installation of Windows extensions

Servers-CGI/Commandline

Testing

Benchmarking

Using Variables

Servers-Apache

Details of installing PHP with Apache on Unix

Installing PHP on Windows with Apache 1.3.x

Servers-Caudium

Servers-fhttpd

Servers-IIS/PWS

Windows and PWS/IIS 3

Windows and PWS 4 or newer

Windows NT/2000/XP and IIS 4 or newer

Servers-Netscape and iPlanet

Installing PHP with Netscape on Sun Solaris

Installing PHP with Netscape on Windows

Servers-OmniHTTPd Server

OmniHTTPd 2.0b1 and up for Windows

Servers-Oreilly Website Pro

Oreilly Website Pro 2.5 and up for Windows

Servers-Sambar

Sambar Windows

Servers-Xitami

Xitami for Windows

Servers-Other web servers

Problems?

Read the FAQ

Other problems

Bug reports

Complete list of configure options

Configure Options in PHP 4

Database options

Graphics options

Misc options

PHP options

Server options

XML options

The configuration file

How to change configuration settings

Running PHP as Apache module

Other interfaces to PHP

Configuration directives

Httpd Options

Language Options

Running `PHP` as Apache module

Other interfaces to `PHP`

Why is `$foo[bar]` wrong?