Searching for only folders that contain a certain folder using powershell

Question

I am trying to use powershell to update some programs for my company. I am writing a script to do so (as instructed). When I install the new version of the program on the machines, it also requires me to 'upgrade' existing folders to match the new version of the software. I need to find all of the folders that contain a certain hidden folder(let the name of said folder be .blah). I am trying to use the get-childitem command, with -path [drives to check] -Recurse -Directory -Force -EA SilentlyContinue. However, I am not sure how to filter correctly to only find folders that contain the .blah folder inside of it. Help would be very much appreciated.

Answer 1

Combine your Get-ChildItem call with a Where-Object call that tests for a child directory of a given name using Test-Path:

# Note: "." refers to the *current* directory
#       Adjust as needed.
Get-ChildItem -LiteralPath . -Recurse -Directory -Force -ErrorAction Ignore |
  Where-Object {
    Test-Path -ItemType Container -LiteralPath "$($_.FullName)\.blah" 
  }

• The Get-ChildItem call outputs all directories (-Directory) in the entire directory subtree (-Recurse), including hidden ones (-Force), ignoring any errors (such as from lack of permissions, -ErrorAction Ignore).

• The Where-Object call calls Test-Path to look for a .blah child directory (-ItemType Container) in the directory at hand ($_).

  • With a -LiteralPath argument, Test-Path finds the specified path if it exists, irrespective of whether the target file or directory is hidden.

    • By contrast, with a wildcard-based -Path argument, hidden items are not found, and given that, as of PowerShell 7.2.5, Test-Path has no -Force switch, there is no way to force their inclusion; this gap in functionality is the subject of GitHub issue #6501.

  • Note: In PowerShell (Core) 7+, you could simplify "$($_.FullName)\.blah" to "$_\.blah", because the [System.IO.DirectoryInfo] and [System.IO.FileInfo] instances output by Get-ChildItem and Get-Item there consistently stringify to their full path (.FullName) property, unlike in WindowsPowerShell, where they situationally stringify by their file/directory name only - see this answer.