Windows – How to Loop Through Folders and Rename Extensions in a Batch File

Since I'm wasting my summer inside anyways I might aswell do something helpful, and write the script for you. Assuming you're using Windows, the following PowerShell script would fit your scenario (just save as a .ps1 file and modify the path at the top).

$TVShowFolderPath = "X:\Series\Dexter";

$TVShowSeasons=$(get-childitem "$TVShowFolderPath");

foreach( $s in $TVShowSeasons)
{
    if( ($s.PSisContainer) -and ($s -imatch "^(Season )(\d{2}|\d{1})$") )
    {
        $season = $matches[2];
        write-host "Season $season";

        $episodes=$(get-childitem $s.FullName);

        foreach( $ep in $episodes)
        {
            if( $ep -imatch "^(season) (\d{2}|\d{1}) (ep) (\d{2}|\d{1})(.*)$")
            {
                $newName = "$($season)x$($matches[4])$($matches[5])";
                write-host "`tEpisode: `"$($ep.Name)`" --> `"$newName`"";
                Rename-Item $ep.FullName $newName;
            }
        }
    }
}

If you want to see if it spits out the correct names first just comment out the line starting with "Rename-Item".

Dbenham is right, your existing posted code should rename both files and folders. The only questionable point lays here: move folder folder with the same Source and Target might result to a breakpoint with The process cannot access the file because it is being used by another process error message (see an example in output below). Simple if /I could solve it as follows:

@echo off
SETLOCAL enableextensions enabledelayedexpansion
SET "old=ACK"
SET "new=XYZ"
for /f "tokens=*" %%f in ('dir /b *%old%*.*') do (
  SET "newname=%%~f"
  SET "newname=!newname:%old%=%new%!"
  if /I "!newname!"=="%%~f" (
        echo ==== "%%~f"
    ) else (
        echo move "%%~f" "!newname!"
    )
)
ENDLOCAL
goto :eof

Output:

==>D:\bat\SuperUser\881861.bat
move "ACKnowledge" "XYZnowledge"
move "assocbackup.txt" "assocbXYZup.txt"
move "ftypebackup.txt" "ftypebXYZup.txt"
move "StackOverflow" "StXYZOverflow"

==>move "ftypebackup.txt" "ftypebackup.txt"
        1 file(s) moved.

==>move "StackOverflow" "StackOverflow"
The process cannot access the file because it is being used by another process.

==>