Powershell start-process -wait parameter fails in remote script block

Question

So here's a sample of what I'm trying to do:

Invoke-Command [Connection Info] -ScriptBlock {
    param (
        [various parameters]
    )
    Start-Process [some .exe] -Wait
} -ArgumentList [various parameters]

It connects to the other machine just fine, and launches the process fine. The problem is it doesn't wait for the process to complete before moving on. This causes issues. Any ideas?

Quick edit: why does the -Wait parameter fail when running the process remotely?

Seems to be a problem with Powershell version 3, not version 2. — Ivan, Oct 09 '14 at 16:01

score 4 · Answer 1 · answered Jun 09 '14 at 22:31

4

I ran into this once before, and IIRC, the workaround was:

Invoke-Command [Connection Info] -ScriptBlock {
    param (
        [various parameters]
    )
    $process = Start-Process [some .exe] -Wait -Passthru

    do {Start-Sleep -Seconds 1 }
     until ($Process.HasExited)

} -ArgumentList [various parameters]

answered Jun 09 '14 at 22:31

mjolinor

66,130
7
114
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The problem with this workaround is that $process.ExitCode is not set – Ivan Oct 09 '14 at 16:00

Ivan · Accepted Answer · 2014-10-09T16:48:06.287

3

This is the problem with Powershell version 3, but not version 2 where -Wait works as it should.

In Powershell 3 .WaitForExit() does the trick for me:

$p = Start-Process [some .exe] -Wait -Passthru
$p.WaitForExit()
if ($p.ExitCode -ne 0) {
    throw "failed"
}

Just Start-Sleep until .HasExited - doesn't set .ExitCode, and it's usually good to know how your .exe finished.

edited Oct 09 '14 at 16:48

answered Oct 09 '14 at 16:43

Ivan

9,089
4
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score 1 · Answer 3 · answered Jun 10 '14 at 06:01

You can also work around this by using the System.Diagnostics.Process class. If you do not care about the output you can just use:

Invoke-Command [Connection Info] -ScriptBlock {
$psi = new-object System.Diagnostics.ProcessStartInfo
$psi.FileName = "powershell.exe"
$psi.Arguments = "dir c:\windows\fonts"
$proc = [System.Diagnostics.Process]::Start($psi)
$proc.WaitForExit()
}

If you do care you can do something similar to the following:

Invoke-Command [Connection Info] -ScriptBlock {
$psi = new-object System.Diagnostics.ProcessStartInfo
$psi.FileName = "powershell.exe"
$psi.Arguments = "dir c:\windows\fonts"
$psi.UseShellExecute = $false
$psi.RedirectStandardOutput = $true
$proc = [System.Diagnostics.Process]::Start($psi)
$proc.StandardOutput.ReadToEnd()
}

This will wait for the process to complete and then return the standard output stream.

Powershell start-process -wait parameter fails in remote script block

3 Answers3