How do I get help messages to appear for my Powershell script parameters?

Question

I have a powershell script (setup.ps1), that we use as the entry point for our development environment setup scripts. It takes a parameter:

param(     [Parameter(Position=0,HelpMessage="The targets to run.")]     [Alias("t")]     [string[]]     $Targets = "Help" ) 

When I run

PS > get-help .\setup.ps1 -detailed 

in the parameters section, my help message doesn't appear:

PARAMETERS     -Targets <String[]> 

What do I need to do to get my parameter help messages to display?

Answer 1

You put a certain style of comment at the top of the file that can be decoded by the PowerShell help system. Here's an example:

<# .SYNOPSIS     . .DESCRIPTION     . .PARAMETER Path     The path to the . .PARAMETER LiteralPath     Specifies a path to one or more locations. Unlike Path, the value of      LiteralPath is used exactly as it is typed. No characters are interpreted      as wildcards. If the path includes escape characters, enclose it in single     quotation marks. Single quotation marks tell Windows PowerShell not to      interpret any characters as escape sequences. .EXAMPLE     C:\PS>      <Description of example> .NOTES     Author: Keith Hill     Date:   June 28, 2010     #> function AdvFuncToProcessPaths {     [CmdletBinding(DefaultParameterSetName="Path")]     param(         [Parameter(Mandatory=$true, Position=0, ParameterSetName="Path",                     ValueFromPipeline=$true,                     ValueFromPipelineByPropertyName=$true,                    HelpMessage="Path to ...")]         [ValidateNotNullOrEmpty()]         [string[]]         $Path,          [Alias("PSPath")]         [Parameter(Mandatory=$true, Position=0, ParameterSetName="LiteralPath",                     ValueFromPipelineByPropertyName=$true,                    HelpMessage="Path to ...")]         [ValidateNotNullOrEmpty()]         [string[]]         $LiteralPath     )     ... 

For more info see the help topic - man about_comment_based_help.