How to capture Powershell errors.

[LisHawj]

I have written the following small script to try and capture the output of a PowerShell file signing result.  I am able to get the output for the success, but I am unable to get an output for when the script is unable to sign a file.  Please let me know what I am missing.  Thank you.

$iPID = _RunDOSCommand(" /c powershell -command " & "import-module c:\SignTool\signpack\sign.psm1;" & " Add-Signature " & $sDefault_Dir & $Filename)

Func _RunDOSCommand($sCommand)
    Local $iPID = Run(@ComSpec & $sCommand, "", @SW_HIDE, BitOR($STDERR_CHILD, $STDOUT_CHILD))
    ;ProcessWaitClose($iPID)
    Local $sOutput = ""
    While 1
        $sOutput &= StdoutRead($iPID)
        If @error Then ; Exit the loop if the process closes or StdoutRead returns an error.
            ExitLoop
        EndIf
        ;MsgBox($MB_SYSTEMMODAL, "Stdout Read:", $sOutput)
    WEnd
   While 1
        $sOutput &= StderrRead($iPID)
        If @error Then ; Exit the loop if the process closes or StdoutRead returns an error.
            ExitLoop
        EndIf
        ;MsgBox($MB_SYSTEMMODAL, "Stdout Read:", $sOutput)
    WEnd
    Msgbox(64,"Result", "$sOutput)
    Return $sOutput
EndFunc   ;==>_RunDOSCommand

 

[rudi]

Hi.

• You can use "Start-Transcript" in powershell to write all output to a TXT file you can analyse later on.
• try $STDERR_MERGED

#include <AutoItConstants.au3>

$sDefault_Dir="some-dir"
$Filename="SomeFile.txt"
_RunDOSCommand(" /c powershell -command " & "import-module c:\SignTool\signpack\sign.psm1;" & " Add-Signature " & $sDefault_Dir & $Filename)

Func _RunDOSCommand($sCommand)
    Local $iPID = Run(@ComSpec & $sCommand, "", @SW_HIDE, $STDERR_MERGED)
    ProcessWaitClose($iPID)
    Local $sOutput = StdoutRead($iPID)
    If @error Then
        MsgBox(48, "Error", @error)
    Else
        MsgBox(0, "StdoutRead with $STDERR_MERGED", $sOutput)
    EndIf
EndFunc   ;==>_RunDOSCommand

 

Edited October 4, 2018 by rudi

[LisHawj]

@Rudi,

Thank you for the STDERR_MERGED example.  That worked for me after I inserted a Return $sOutput.  I am now able to capture both STDOUT and STDERR streams.

/Double thumbs up!

Though I am curious and want to understand why the original method to capture the STDERR stream I used didn't work.  Knowing why it didn't work will help me to understand for future coding.

Edited October 5, 2018 by LisHawj

[rudi]

@LisHawj

glad to help.

 

If I'm allowed to comfort you: It took me quite a while to figure out that $STDERR_MEREGED thing, when I needed to grab that info for the first time.

 

And I'm still not through, e.g. the command line version of wireshark (tshark) is writing the number of packets captured so far to always the same position, and with STDOUT as well as STDERR it seems to be impossible to grab that output.

 

 

 

Regards, Rudi.