Today, I had the need to replicate the bash command at in a PowerShell script that I was writing for an AWS SSM Document.

In bash, the command looks like this: 

echo 'echo hello world' | at now + 1 minute

You won’t see the output of this echo in your terminal, since it’s being run in another process, but sure enough, the echo hello world command will run a minute later.

PowerShell doesn’t have this same functionality and so I have found the following way of reproducing it. If you have a better way, please do let me know in the comments.

Background Jobs

First, I create the script I want to run and I save it into the $myjob variable.

$myjob = {Start-Sleep 5; Write-Host "hello world"}

I can then run the Job as a Background Job. 

$refjob = Start-Job -ScriptBlock $myjob

I am then able to go about executing other commands and my process is not blocked.

I can check on the progress of the job by looking at the state:

$refjob.State

I can also awkwardly check on the job (whilst blocking the process) using the following syntax (If you have any ideas on how I can do this more cleanly, please do let me know):

do { Start-Sleep -Milliseconds 100 } until ($refjob.State -eq "Completed")

Finally, to clear things up, I pipe the Job Reference to the Remove-Job Cmdlet.

$refjob | Remove-Job