I would like to make a PowerShell script trigger other scripts based on the existence of *.mp4 files in subfolders of a parent folder.

The question is the following: I have a folder called "Cut" inside that folder I have other folders that follow the logic Model 01, Model 02, Model 03...

Inside each Model XX folder I have a .ps1 script that I would like to be triggered every time there is a .mp4 file inside it.

The main point is that this script would have to be called in a new instance, not inside the main script.

What's the best way to do this?

What I've come up with so far is this:

Get-ChildItem -Path "$env:USERPROFILE\Desktop\Cut" -Recurse -Filter "*.mp4" -ea 0 | ForEach-Object {
    Start-Process powershell ".\ffmpeg.ps1"
    }

CodePudding user response：

I suggest inverting the logic by searching for all ffmpeg.ps1 files, and filtering them by whether at least one *.mp4 is present alongside each:

Get-ChildItem -Path $env:USERPROFILE\Desktop\Cut -Recurse -Filter ffmpeg.ps1 |
  Where-Object { Test-Path (Join-Path $_.DirectoryName *.mp4) } |
  ForEach-Object {
    Start-Process -WorkingDirectory $_.DirectoryName powershell.exe "-NoExit -File `"$($_.FullName)`""
  }

• Inverting the logic ensures that you call a given directory's ffmpeg.ps1 file only once, whereas invoking it once for each *.mp4 file in that directory, which is what your own approach attempted, is probably undesired.

• The -WorkingDirectory parameter of Start-Process is used to set the working directory to the respective ffmpeg.ps1's directory.

• The -File parameter of powershell.exe, the Windows PowerShell CLI, is used to invoke each target script, which is the preferred way to invoke script files (without it , powershell.exe defaults to -Command, which behaves subtly differently)

  • See this answer for guidance on when to use -File vs. -Command.

• -NoExit is additionally passed so as to keep the window of the newly launched process open after the script terminates, to allow you to examine the results.

CodePudding user response：

Get-ChildItem -Path "$env:USERPROFILE\Desktop\Cut" -Recurse -Filter "*.mp4" -ea 0 | ForEach-Object {
   Invoke-Item (start powershell (Split-Path $_.FullPath   "\ffmpeg.ps1 $_.Name")
}

The first part seems quit alright to me. Secondly you can invoke your script using the path of of the matched file (split-path) but u also want to to to hand over the target file to the script as paramenter in the end.