Edit: There’s a quick addition at the bottom of this post. I tried something else, it worked, and so I decided to include it.

I started writing a PowerShell function to replicate the work of an old executable called ICSWEEP. ICSWEEP “is a command-line utility to clear the Temporary Internet Files Cache and/or the TEMP files folder of ALL user profiles that are NOT in use when this command is executed.” ICSWEEP Information. I may or may not walk through the process of writing this function here; it’s to be determined. What I do want to discuss for sure, however, is the last switch in the above image. It’s /?.

We cannot add ? parameter to a function. Below is an image of the message when we attempt to do that in VS Code.

That’s right, right!? You do remember the $? variable. It stores the execution status of the last command as True or False. Instead of ? as a parameter, I used the value of Help. Therefore, someone can invoke my function and use -Help to get help with the function. But could they?

I sat there, wondering, can you create a parameter of a function so that it’ll return its own, comment-based help? It turns out you can. Here’s the early stage of this function. It consists of the comment-based help, a few parameters, and a small amount of code.

function Clear-UserTemporaryFile {
<#
.SYNOPSIS
    The Clear-UserTemporaryFile command ...
.DESCRIPTION
.PARAMETER <Parameter>
.EXAMPLE
.NOTES
    Name: Clear-UserTemporaryFile
    Author: Tommy Maynard
    Comments: --
    Last Edit: 12/13/2022 [1.0.0]
    Version: 1.0.0
#>
    Param (
        [Parameter()]
        [switch]$ALL,
        [Parameter()]
        [string]$TIF,
        [Parameter()]
        [string]$TMP,
        [Parameter()]
        [string]$SIZE,
        [Parameter()]
        [switch]$HELP
        
    )

    if ($HELP) {
       Get-Help -Name "$($MyInvocation.MyCommand.Name)"
       Exit
    }
}

In the above code, I added a simple if statement. It monitors whether or not the Help parameter is used when the function is invoked. If it is, it runs the Get-Help cmdlet against the name of the executing function—itself—using the $MyInvocation variable and then exits the function.

Clear-UserTemporaryFile -Help

NAME
    Clear-UserTemporaryFile

SYNOPSIS
    The Clear-UserTemporaryFile command ...

SYNTAX
    Clear-UserTemporaryFile [-ALL] [[-TIF] <String>] [[-TMP] <String>] [[-SIZE] <String>] [-HELP] [<CommonParameters>]

DESCRIPTION

RELATED LINKS

REMARKS
    To see the examples, type: "Get-Help Clear-UserTemporaryFile -Examples"
    For more information, type: "Get-Help Clear-UserTemporaryFile -Detailed"
    For technical information, type: "Get-Help Clear-UserTemporaryFile -Full"

At this point, some of you may already know where I’m going to go next. There was something else I had forgotten about every cmdlet and function written. They all have something in common. And what’s that? There is a way to return a command’s help using, of all things, the question mark! Take a look using the built-in Get-Verb and Get-Command cmdlets below.

Get-Verb -?

NAME
    Get-Verb

SYNTAX
    Get-Verb [[-Verb] <string[]>] [[-Group] {Common | Communications | Data | Diagnostic | Lifecycle | Other |
    Security}] [<CommonParameters>]

ALIASES
    None

REMARKS
    Get-Help cannot find the Help files for this cmdlet on this computer. It is displaying only partial help.
        -- To download and install Help files for the module that includes this cmdlet, use Update-Help.
        -- To view the Help topic for this cmdlet online, type: "Get-Help Get-Verb -Online" or
           go to https://go.microsoft.com/fwlink/?LinkID=2097026.

Get-Command -?

NAME
    Get-Command

SYNTAX
    Get-Command [[-ArgumentList] <Object[]>] [-Verb <string[]>] [-Noun <string[]>] [-Module <string[]>]
    [-FullyQualifiedModule <ModuleSpecification[]>] [-TotalCount <int>] [-Syntax] [-ShowCommandInfo] [-All]
    [-ListImported] [-ParameterName <string[]>] [-ParameterType <PSTypeName[]>] [<CommonParameters>]

    Get-Command [[-Name] <string[]>] [[-ArgumentList] <Object[]>] [-Module <string[]>] [-FullyQualifiedModule
    <ModuleSpecification[]>] [-CommandType {Alias | Function | Filter | Cmdlet | ExternalScript | Application | Script
    | Configuration | All}] [-TotalCount <int>] [-Syntax] [-ShowCommandInfo] [-All] [-ListImported] [-ParameterName
    <string[]>] [-ParameterType <PSTypeName[]>] [-UseFuzzyMatching] [-UseAbbreviationExpansion] [<CommonParameters>]

ALIASES
    gcm

REMARKS
    Get-Help cannot find the Help files for this cmdlet on this computer. It is displaying only partial help.
        -- To download and install Help files for the module that includes this cmdlet, use Update-Help.
        -- To view the Help topic for this cmdlet online, type: "Get-Help Get-Command -Online" or
           go to https://go.microsoft.com/fwlink/?LinkID=2096579.

This means I don’t even need a Help parameter. PowerShell already has this covered, and here’s the proof.

Clear-UserTemporaryFile -?

NAME
    Clear-UserTemporaryFile

SYNOPSIS
    The Clear-UserTemporaryFile command ...

SYNTAX
    Clear-UserTemporaryFile [-ALL] [[-TIF] <String>] [[-TMP] <String>] [[-SIZE] <String>] [-HELP] [<CommonParameters>]

DESCRIPTION

RELATED LINKS

REMARKS
    To see the examples, type: "Get-Help Clear-UserTemporaryFile -Examples"
    For more information, type: "Get-Help Clear-UserTemporaryFile -Detailed"
    For technical information, type: "Get-Help Clear-UserTemporaryFile -Full"

Edit: We know that we were able to use this PowerShell to return the help for our function,

Get-Help -Name "$($MyInvocation.MyCommand.Name)"

but we could’ve just as easily done this:

Invoke-Expression -Command "$($MyInvocation.MyCommand.Name) -?"

The first option invokes the Get-Help cmdlet against our function. The second option invokes the same function that’s already being invoked, adding a -? to the end of the complete command.