PowerShell stdout and redirect

Question

I would like to build powershell pipeline like

cmd | transform_a | stdout_and | transform_b | store_variable
                         ^
                         |
    copy input to next consumer and to console

I tried to utilize Tee-Object but without success. I dont want to do this

dir | select -last 5 | tee lastFiveLines | select -first 1
echo $lastFiveLines

altough it works. Instead I want the content to be printed directly.

Answer 1

You can try a foreach-loop and Out-Default or Out-Host to skip the rest of the pipeline (Host is Default output anyways), while also sending the object down the pipeline. Sample:

Get-ChildItem |
Select-Object Name, FullName |
ForEach-Object { 
    #Send Name-value directly to console (default output)
    $_.Name | Out-Default
    #Send original object down the pipeline
    $_
} |
Select-Object -ExpandProperty FullName | % { Start-sleep -Seconds 1; "Hello $_" }

You can create a filter to make it easy to reuse it.

#Bad filter-name, but fits the question.
filter stdout_and { 
    #Send Name-value directly to console (default output)
    $_.Name | Out-Default
    #Send original object down the pipeline
    $_
}

Get-ChildItem |
Select-Object Name, FullName |
stdout_and |
Select-Object -ExpandProperty FullName | % { Start-sleep -Seconds 1; "Hello $_" }