Powershell running under a service hangs on *.zip CopyHere

Question

I'm running a Windows Service (Hudson) which in turn spawns a PowerShell process to run my custom PowerShell commands. Part of my script is to unzip a file using CopyHere. When I run this script locally, I see a progress dialog pop up as the files are extracted and copied. However, when this runs under the service, it hands at the point where a dialog would otherwise appear.

Here's the unzip portion of my script.

# Extract the contents of a zip file to a folder
function Extract-Zip {
    param([string]$zipFilePath, [string]$destination)
    if(test-path($zipFilePath))     {   
        $shellApplication = new-object -com shell.application

        $zipFile = get-item $zipFilePath
        $zipFolder = $shellApplication.NameSpace($zipFile.fullname)

        $destinationFile = get-item $destination
        $destinationFolder = $shellApplication.NameSpace($destinationFile.fullname)

        $destinationFolder.CopyHere($zipFolder.Items())
    }
}

I suspect that because its running under a service process which is headless (no interaction with the desktop), its somehow stuck trying to display a dialog.

Is there a way around this?

Answer 1

Looking at the documentation for PowerShell, it looks like the -NonInteractive option may help here

Answer 2

If this is running on Vista or Windows 7, popping up UI from a service isn't going to be seen by the end user as you suspected. See this paper on Session 0 Isolation. However, does the progress dialog require user input? If not, I wouldn't think that would cause the service to hang. I would look for an option to disable the progress display. If you can't find that, then try switching to another ZIP extractor. PSCX 1.2 comes with an Expand-Archive cmdlet. I'm sure there are also others available.