Geoff @ UVM

Update: better yet, read about the -Join and -Split PowerShell operators. Live and learn.
—Geoff

Something I’ve found myself missing in PowerShell is a function to combing the elements of a list with a given separator, like Perl’s join() function. I finally got annoyed enought to write one. It seems to do what I want, so I’m going to add it to my profile.

Here it is in action:

PS C:\> $array = 3.14,'Puppy',$false,'','Green',$null,'foo'
PS C:\> $array | Join-String
3.14,Puppy,False,,Green,,foo
PS C:\> $array | Join-String -collapse
3.14,Puppy,Green,foo
PS C:\> $array | Join-String -collapse ' - '
3.14 - Puppy - Green - foo

Here’s the code:

# Join-String - A simple pipeline-oriented function to
# concatenate a bunch of strings together with a separator
# Geoffrey.Duke@uvm.edu  Wed 11/17/2010 

function Join-String
(   [string] $separator = ',',
    [switch] $Collapse )
{ 

begin {
    [string] $string = '';
    $first  =  $true;
}

process {
    foreach ( $element in $_ ) {
        #Skip blank elements if -Collapse is specified
        if ( $Collapse -and ($element -eq '' -or $element -eq $null ) ) {
            continue
        }

        if ($first) {
            $string = $_
            $first  = $false
        }
        else {
            $string += $separator + $element -as [string]
        }
    }
}

end {
    $string
}

}

If you have a notion for how it could be improved, please comment.

I’m upgrading the components of the user provisioning system I built. Previously, I used ActiveState Perl and the UWinnipeg PPM repository to get the Net::LDAPS stack working.

This time, though, I decided I wanted to use the native architecture of my Server 2008 R2 systems. I am using the Perl64 install from ActiveState, but I have to build my own SSL libraries (and maybe roll up PPMs for the needed perl mods).

I just compiled OpenSSL for x64 (amd64), mostly following the instructions in the INSTALL.W64 and INSTALL.W32 documents. I’m blogging the step for my future reference:

1. Open a VS x64 Win64 Command Prompt and navigate to the source directory
2. perl Configure VC-WIN64A –prefix=c:\local\openssl
3. ms\do_win64a.bat
4. nmake -f ms\ntdll.mak
5. nmake -f ms\ntdll.mak test (all tests passed)
6. nmake -f ms\ntdll.mak install

Running the openssl command succeeds:

C:\local\openssl\bin>openssl version
  OpenSSL 1.0.0a 1 Jun 2010

[contains some adult language : f-word]

Since we don’t use DHCP in our server subnets, I frequently have to locate free IP addresses when deploying a server. I remembered reading a TechNet Magazine article by Don Jones that used the PowerShell PROCESS block and the Win32_PingStatus WMI class in a sample script.

I took that and rewrote the function a little:

function Ping-Address {
  PROCESS {
    $ping = 'unreachable'
    $formatstring = "{0,-15}  {1,-12} {2}"
    $queryString  = "SELECT * FROM Win32_PingStatus"
    $queryString += " WHERE Address = '$_' AND"
    $queryString += " ResolveAddressNames = $true"
    $results = Get-WmiObject -query $queryString

    foreach ($result in $results) {
      if ($results.StatusCode -eq 0) {
        $ping = 'ping!'
      }
    }
    $formatstring -f $_,$ping,$results.ProtocolAddressResolved
   }
}

I can then use this function like so:

PS Z:\> (14..20) | %{ '132.198.59.'+ $_.ToString()} | Ping-Address
132.198.59.14    ping!        132.198.59.14
132.198.59.15    ping!        132.198.59.15
132.198.59.16    ping!        xxxxxxx.campus.ad.uvm.edu
132.198.59.17    ping!        xxxxxxx.uvm.edu
132.198.59.18    unreachable
132.198.59.19    ping!        xxxx.uvm.edu
132.198.59.20    unreachable

I’ve already used it a bunch of times. I think I will probably grow this into a real script, taking the IP address range info as parameters. Another day…