Are You Sure You Want to Do This?

            June 3, 2025

        Are You Sure You Want to Do This?

            I know I've written before about adding support for -WhatIf to your PowerShell commands. However, I'm not sure I've fully covered the related topic of -Confirm and how it can be used to prompt the user for confirmation before executing a command. Let's remedy that today.
Here's a simple example that defines support for -WhatIf and -Confirm in a PowerShell function:
Function Set-Folder {
    [cmdletbinding(SupportsShouldProcess)]
    Param(
        [Parameter(
            Position = 0,
            ValueFromPipeline,
            ValueFromPipelineByPropertyName
        )]
        [Alias('pspath')]
        [ValidateScript( { Test-Path $_ })]
        [string]$Path = '.')

    Process {
        $Path = (Resolve-Path -Path $Path).ProviderPath
        if ($PSCmdlet.ShouldProcess($Path)) {
            #do the action
            $Path.ToUpper()
        }
    } #Process
} #end function

You can see the parameters.
PS C:\&gt; Get-Command Set-Folder -Syntax

Set-Folder [[-Path] <string>] [-WhatIf] [-Confirm] [<commonparameters>]

And the expected behavior.
PS C:\&gt; Set-Folder c:\temp -WhatIf
What if: Performing the operation "Set-Folder" on target "C:\temp".
PS C:\&gt; Set-Folder c:\temp -confirm

Confirm
Are you sure you want to perform this action?
Performing the operation "Set-Folder" on target "C:\temp".
[Y] Yes  [A] Yes to All  [N] No  [L] No to All  [S] Suspend  [?] Help (default is "Y"): y
C:\TEMP

In the function I am defining my own WhatIf support using $PSCmdlet.ShouldProcess. You have an option to use $PSCmdlet.ShouldContinue` instead, although you will get different behavior.
Function Set-Folder {
    [cmdletbinding(SupportsShouldProcess)]
    Param(
        [Parameter(
            Position = 0,
            ValueFromPipeline,
            ValueFromPipelineByPropertyName
        )]
        [Alias('pspath')]
        [ValidateScript( { Test-Path $_ })]
        [string]$Path = '.')

    Process {
        $Path = (Resolve-Path -Path $Path).ProviderPath
        #ShouldContinue("query","caption")
        if ($PSCmdlet.ShouldContinue("Do you want to process folder",$Path)) {
            #do the action
            $Path.ToUpper()
        }
    } #Process
} #end function

The result may not be what you expect.
PS C:\&gt; Set-Folder c:\temp

C:\temp
Do you want to process folder
[Y] Yes  [N] No  [S] Suspend  [?] Help (default is "Y"): n
PS C:\&gt; Set-Folder c:\temp -WhatIf

C:\temp
Do you want to process folder
[Y] Yes  [N] No  [S] Suspend  [?] Help (default is "Y"): n
PS C:\&gt; Set-Folder c:\temp -Confirm

C:\temp
Do you want to process folder
[Y] Yes  [N] No  [S] Suspend  [?] Help (default is "Y"): n
PS C:\&gt;

                Want to read the full issue?

Behind the PowerShell Pipeline

Are You Sure You Want to Do This?