PowerShell -PassThru Parameter

last modified February 15, 2025

In this article, we will cover the -PassThru parameter in PowerShell. This parameter returns objects that would otherwise not be returned by default.

-PassThru basics

The -PassThru parameter tells cmdlets to return output objects even when they normally wouldn't. Many cmdlets perform actions without output by default. -PassThru forces these cmdlets to return the affected objects. This is useful for chaining commands in pipelines.

Basic -PassThru usage with Stop-Process

By default, Stop-Process doesn't return any output when it terminates processes. With -PassThru, it returns the stopped process objects. This allows you to verify the action or pipe results.

Stop-Process -Name "notepad" -PassThru

This command stops all Notepad processes and returns their objects. Without -PassThru, you would get no confirmation of the action.

Using -PassThru with Start-Process

Start-Process doesn't return the new process object by default. With -PassThru, you get the Process object of the started application. This is useful for tracking or managing the new process.

$proc = Start-Process notepad -PassThru
$proc | Select-Object Id, Name, StartTime

This starts Notepad and stores its Process object in $proc. We then display selected properties of the new process.

-PassThru with Wait-Process

Wait-Process normally doesn't return anything when waiting completes. With -PassThru, it returns the waited-on process object. This confirms which process was being monitored.

$proc = Start-Process notepad -PassThru
Wait-Process -InputObject $proc -PassThru

This starts Notepad, waits for it to exit, then returns its process object. The output confirms which process was waited on.

Combining -PassThru with Where-Object

You can filter processes before passing them to another cmdlet with -PassThru. This example stops high-memory processes while keeping the pipeline flowing. The filtered processes are passed through.

Get-Process | Where-Object { $_.WS -gt 100MB } | 
Stop-Process -PassThru | 
Format-Table Name, Id, WS -AutoSize

This finds processes using over 100MB of working set, stops them, and formats the output. -PassThru enables the pipeline flow.

-PassThru with Debug-Process

Debug-Process attaches a debugger without output by default. With -PassThru, it returns the process being debugged. This helps confirm the debugging target.

Debug-Process -Name "powershell" -PassThru

This attaches a debugger to PowerShell processes and returns them. Without -PassThru, you wouldn't see which processes were affected.

Using -PassThru with Suspend-Process

Suspend-Process pauses processes without output by default. With -PassThru, it returns the suspended process objects. This verifies which processes were paused.

Suspend-Process -Name "notepad" -PassThru

This suspends Notepad processes and returns their objects. You can then resume them later using Resume-Process.

-PassThru with Resume-Process

Resume-Process resumes suspended processes without output. With -PassThru, it returns the resumed process objects. This confirms which processes were reactivated.

Resume-Process -Name "notepad" -PassThru

This resumes previously suspended Notepad processes and returns them. The output shows the processes that were brought back to running state.

Chaining multiple -PassThru operations

You can chain multiple operations with -PassThru to maintain the pipeline. This example starts, waits for, and stops a process while keeping the object flowing through each step.

Start-Process notepad -PassThru | 
Wait-Process -PassThru | 
Stop-Process -PassThru

This starts Notepad, waits for it to exit, then stops it, with each cmdlet passing the Process object to the next. -PassThru enables this entire pipeline to work.

Source

PowerShell documentation

In this article, we have covered the -PassThru parameter in PowerShell.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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