Powershell: How to get -whatif to propagate to cmdlets in another module

问题:

I've been trying write safe code that supports -whatif with the ShouldProcess method so my users have an idea of what a cmdlet is supposed to do before they run it for real.

However I’ve run into a bit of a snag. If I call a script with -whatif as an argument, $pscmdlet.ShouldProcess will return false. All well and good. If I call a cmdlet defined in the same file (that has SupportsShouldProcess=$true) it will return false as well.

However, if I am calling a cmdlet defined in another module I have loaded using Import-Module, it will return true. The -whatif context does not seem to get passed through to calls in the other module.

I don't want to have to manually pass in a flag to every cmdlet. Does anyone have a better solution?

This issue seems related to this question. However, they are not talking about the cross-module problem.

Example Script:

#whatiftest.ps1 [CmdletBinding(SupportsShouldProcess=$true)] param()  Import-Module  -name .\whatiftest_module  -Force  function Outer {     [CmdletBinding(SupportsShouldProcess=$true)]     param()     if( $pscmdlet.ShouldProcess("Outer"))     {         Write-Host "Outer ShouldProcess"     }     else     {         Write-Host "Outer Should not Process"     }      Write-Host "Calling Inner"     Inner     Write-Host "Calling InnerModule"     InnerModule }  function Inner {     [CmdletBinding(SupportsShouldProcess=$true)]     param()      if( $pscmdlet.ShouldProcess("Inner"))     {         Write-Host "Inner ShouldProcess"     }     else     {         Write-Host "Inner Should not Process"     } }      Write-Host "--Normal--"     Outer      Write-Host "--WhatIf--"     Outer -WhatIf 

The Module:

#whatiftest_module.psm1  function InnerModule  {     [CmdletBinding(SupportsShouldProcess=$true)]     param()          if( $pscmdlet.ShouldProcess("InnerModule"))     {         Write-Host "InnerModule ShouldProcess"     }     else     {         Write-Host "InnerModule Should not Process"     }  } 

Output:

F:\temp> .\whatiftest.ps1 --Normal-- Outer ShouldProcess Calling Inner Inner ShouldProcess Calling InnerModule InnerModule ShouldProcess --WhatIf-- What if: Performing operation "Outer" on Target "Outer". Outer Should not Process Calling Inner What if: Performing operation "Inner" on Target "Inner". Inner Should not Process Calling InnerModule InnerModule ShouldProcess 

回答1:

To do this, you can use a technique I call "CallStack peeking". Use Get-PSCallStack to look up at whatever called the function. Each item will have an InvocationInfo, and a inside of that will be a property called "BoundParameters". This has the parameters @ each level. If -WhatIf was passed to any of them, you can act like -WhatIf was passed to your function.

Hope this helps

文章来源: Powershell: How to get -whatif to propagate to cmdlets in another module