How can I pass an argument to a PowerShell script?

Question

There's a PowerShell script named itunesForward.ps1 that makes iTunes fast forward 30 seconds:

$iTunes = New-Object -ComObject iTunes.Application  if ($iTunes.playerstate -eq 1) {   $iTunes.PlayerPosition = $iTunes.PlayerPosition + 30 } 

It is executed with a prompt line command:

powershell.exe itunesForward.ps1 

Is it possible to pass an argument from the command line and have it applied in the script instead of the hardcoded 30 seconds value?

Answer 1

Tested as working:

#Must be the first statement in your script (not coutning comments) param([Int32]$step=30)   $iTunes = New-Object -ComObject iTunes.Application  if ($iTunes.playerstate -eq 1) {   $iTunes.PlayerPosition = $iTunes.PlayerPosition + $step } 

Call it with

powershell.exe -file itunesForward.ps1 -step 15 

Multiple parameters syntax (comments are optional, but allowed):

<#     Script description.      Some notes. #> param (     # height of largest column without top bar     [int]$h = 4000,          # name of the output image     [string]$image = 'out.png' ) 

And some example for advanced parameters, e.g. Mandatory:

<#     Script description.      Some notes. #> param (     # height of largest column without top bar     [Parameter(Mandatory=$true)]     [int]$h,          # name of the output image     [string]$image = 'out.png' )  Write-Host "$image $h" 

A default value will not work with a mandatory parameter. You can omit the =$true for advanced parameters of type boolean [Parameter(Mandatory)].