Vfrdtyky

I want to avoid errors provoked by a null dsquery. I tried this:

try {

     dsquery user forestroot -samid $a[$i] | dsget user -email | Select-String '@' | select -Expand Line >> output.txt

}

catch [Exception] {

    return $_.Exception.Message

}

But I'm still getting:

dsget : dsget failed:'Target object for this command' is missing.

At ExpiringCertificates.ps1:35 char:49

+         dsquery user forestroot -samid $a[$i] | dsget user -email | Select-Strin ...

+                                                 ~~~~~~~~~~~~~~~~~

    + CategoryInfo          : NotSpecified: (dsget failed:'T...nd' is missing.:String) , RemoteException

    + FullyQualifiedErrorId : NativeCommandError



type dsget /? for help.

How should I handle it?

This might work for you:

try {

     $erroractionpreference = 'stop'

     dsquery user forestroot -samid $a[$i] | dsget user -email | Select-String '@' | select -Expand Line >output

}

catch [Exception] {

    return $_.Exception.Message

}

Try this:

try

{

    dsquery user forestroot -samid $a[$i] | dsget user -email | Select-String '@' | select -Expand Line >> output.txt

}

catch

{

    Write-Error -ErrorRecord $_

}

If $ErrorActionPreference is set to 'Stop', Write-Error will throw an exception and halt execution. Otherwise, it will print to the error stream and continue execution. This allows the caller to decide whether or not to continue on error and keeps you from having to set global variables in your scripts.

If you need to print and return the error message, use the -ErrorVariable parameter:

catch

{

    $errorVar = $null

    Write-Error -ErrorRecord $_ -ErrorVariable errorVar

    return $errorVar

}

Or, if you need to return the error message without printing it, add the "2>" redirect:

catch

{

    $errorVar = $null

    Write-Error -ErrorRecord $_ -ErrorVariable errorVar 2> $null

    return $errorVar

}

dsquery and dsget are not PowerShell commands, so PowerShell looks at the standard error, and processes it, turning it into an ErrorRecord with a "NativeCommandError" exception attached to it, and then sends a text representation of that record to the standard output.

However, if you process the standard error yourself, you have a bit more flexibility:

dsquery user forestroot -samid $a[$i] | dsget user -email | Select-String '@' | select -Expand Line 2>&1

If ($_ -is [Management.Automation.ErrorRecord]) {

    $message = $_.Exception.Message

    # Do what you want with $message.

} Else {

    $_ >> output.txt

}