Renaming folder with filename in PowerShell 4.0

Question

I've got a lot of folders that I want to batch rename using PowerShell. In each folder there are a lot of different files with different extensions. What I want to do is to rename the folder with the *.nfo filename.

Example:

C:\foldertest\TEST\ In this folder these files reside:
JPG.jpg
NFO.nfo
TXT.txt
WAV.wav

After running a script I want the folder to be renamed like the *.nfo:
C:\foldertest\NFO\
I need a solution that works on > 1 folder at a time.

This is what I have (not working o/c):
Get-ChildItem -Path "C:\foldertest\" | Where-Object{$_.PSisContainer} | ForEach-Object -Process { $new1Name = Get-ChildItem $_ -Filter "*.nfo" | Select-Object -ExpandProperty BaseName Rename-Item -Path $_.FullName -NewName ($_.Name -replace $new1Name }

UPDATE: I am still having problems. The solution (see below) seemed to work at first, but only sometimes. Let's say on 30% of the folders. Then this error happens on the rest:
Rename-Item : Cannot rename because item at 'C:\Users\STOFFES\Desktop\REN\blablablabla' does not exi st. At C:\Users\STOFFES\Desktop\REN\REN.ps1:2 char:3 + Rename-Item (Split-Path $_ -Parent) ($_.BaseName) + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : InvalidOperation: (:) [Rename-Item], PSInvalidOperationException + FullyQualifiedErrorId : InvalidOperation,Microsoft.PowerShell.Commands.RenameItemCommand

Even though there are *.nfo files in most of the folders.

Answer 1

Get-ChildItem -Path "E:\Test\Rename" -Include "*.nfo" -Recurse | 
ForEach-Object {
    $oldFolder = $_.DirectoryName

    # New Folder Name is .nfo Filename, excluding extension
    $newFolder = $_.Name.Substring(0, $_.Name.Length - 4)

    # Verify Not Already Same Name
    if ($_.BaseName.ToUpper() -ne $newFolder.ToUpper()) {
        Write-Host "Rename: $oldFolder To: $newFolder"

        Rename-Item -NewName $newFolder -Path $oldFolder
    }
}

Do you have multiple levels of subfolders? That's most likely why you're getting 'Cannot rename because item does not exist' errors, because you've already renamed a parent folder. If that's the case, you'll need something more complex.

Answer 2

Perhaps something like this?

Get-ChildItem *.nfo -File -Recurse | ForEach-Object {
  Rename-Item (Split-Path $_ -Parent) ([IO.Path]::GetFileNameWithoutExtension($_.Name)) -WhatIf
}

Requires PowerShell 3+ due to -File parameter. Remove -WhatIf when ready.

(Aside: The Where-Object filter you have in your command is no longer necessary in PowerShell 3.0 and later because it has the -File and -Directory parameters.)