CODEWITHSUNDEEP
powershell
Chris G.
Chris G.

Reputation: 25954

powershell debugging: script vs local, global and auto

When debugging Powershell, what is the difference between local vs script in VSCode?

I have looked for the current folder, calling a module(psm1) and it confused me that $PSScriptRoot did not give the right path.

I have a main.ps1 importing some module.psm1.

In root folder(myroot), main.ps1:

-- Import-Module sub/module.psm1`

module.psm1:

...
Get-Folder() {return $PSScriptRoot}
..

This gives me the folder myroot/sub the modules folder , but if I do: module.psm1:

...
Get-Folder() {return $local:MyInvocation.PSScriptRoot}
...

Then I get the right folder myroot calling the modul - so basically:

$local:MyInvocation.PSScriptRoot

vs

$script:MyInvocation.PSScriptRoot

vs

$PSScriptRoot

Upvotes: 1

Views: 513

Answers (1)

G42
G42

Reputation: 10019

From the about_automatic_variables documentation:*

Unlike the $PSScriptRoot and $PSCommandPath automatic variables, the PSScriptRoot and PSCommandPath properties of the $MyInvocation automatic variable contain information about the invoker or calling script, not the current script.

From the about_scopes documentation:*

Local: The current scope. The local scope can be the global scope or any other scope.

Script: The scope that is created while a script file runs. Only the commands in the script run in the script scope. To the commands in a script, the script scope is the local scope.

Combining these gives you the behavior you're seeing.

So basically if you want to find out the location of the currently running code, use $PSScriptRoot.

If you want to find out what's calling that code, use $MyInvocation.PSScriptRoot.

The $local: scope modifier will give you this from the currently running code, the $script: modifier will list the location of last calling script (i.e. these will be different if you called a function in another module from module.psm1 because $local: will refer to module.psm1 location and $script: will refer to main.ps1 location, as main.ps1 is the calling script).

If it still doesn't make sense, let me know and I'll put together some demo scripts.

*emphasis added

Upvotes: 3

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