Determine Functions Pipeline Position with PowerShell

by Sep 26, 2012

Assume your function wanted to know whether it is the last element in a pipeline or operating in the middle of it. Here is a way for a function to determine its current pipeline position:

function test {
    param( [Parameter(ValueFromPipeline=$true)]$data )

    process {
    if ($MyInvocation.PipelinePosition -ne $MyInvocation.PipelineLength) {
        } else {
            Write-Host $data -foreground Red -background White

1..3 | test
1..3 | test | Get-Random -count 3

"test" will output the data in red color when it is the last element (thus controlling presentation itself) whereas it forwards the data if it is not the last pipeline command.

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