Recursively renaming files with Powershell

Question

I currently have a line to batch rename files in a folder that I am currently in.

dir | foreach { move-item -literal $_ $_.name.replace(".mkv.mp4",".mp4") }

This code works perfectly for whatever directory I'm currently in, but what I want is to run a script from a parent folder which contains 11 child-folders. I can accomplish my task by navigating to each folder individually, but I'd rather run the script once and be done with it.

I tried the following:

get-childitem -recurse | foreach { move-item -literal $_ $_.name.replace(".mkv.mp4",".mp4") }

Can anyone please point me in the right direction here? I'm not very familiar with Powershell at all, but it suited my needs in this instance.

Answer 1

You were close:

Get-ChildItem -File -Recurse | % { Rename-Item -Path $_.PSPath -NewName $_.Name.replace(".mkv.mp4",".mp4")}

Answer 2

There is a not well-known feature that was designed for exactly this scenario. Briefly, you can do something like:

Get-ChildItem -Recurse -Include *.ps1 | Rename-Item -NewName { $_.Name.replace(".ps1",".ps1.bak") }

This avoids using ForEach-Object by passing a scriptblock for the parameter NewName. PowerShell is smart enough to evaluate the scriptblock for each object that gets piped, setting $_ just like it would with ForEach-Object.