Question:
I have one PowerShell (2.0) script calling another. I want to receive back not only the main output, but an additional object that I can use separately, e.g. to display a Summary Line in a message.
Let’s have Test2.ps1 as the script being called:
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param([String]$SummaryLine) $Issues = "Potentially long list of issues" $SummaryLine = "37 issues found" $Issues |
And Test1.ps1 as the script that calls it:
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$MainOutput = & ".\Test2.ps1" -SummaryLine $SummaryOutput $MainOutput $SummaryOutput |
The output is simply:
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Potentially long list of issues |
Although the parameter $SummaryLine is filled in by Test2, $SummaryOutput remains undefined in Test1.
Defining $SummaryOutput before calling Test2 doesn’t help; it just retains the value assigned before calling Test2.
I’ve tried setting up $SummaryOutput and $SummaryLine as a [ref] variables (as one can apparently do with functions), but the $SummaryOutput.Value property is $null after calling Test2.
Is it possible in PowerShell to return a value in a parameter? If not, what are the workarounds? Directly assigning a parent-scoped variable in Test2?
Answer:
Ref should work, you don’t say what happened when you tried it. Here is an example:
Test.ps1:
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Param ([ref]$OptionalOutput) "Standard output" $OptionalOutput.Value = "Optional Output" |
Run it:
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$x = "" .\Test.ps1 ([ref]$x) $x |
Here is an alternative that you might like better.
Test.ps1:
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Param ($OptionalOutput) "Standard output" if ($OptionalOutput) { $OptionalOutput | Add-Member NoteProperty Summary "Optional Output" } |
Run it:
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$x = New-Object PSObject .\Test.ps1 $x $x.Summary |