Question

I am trying to write a simple batch file that deletes all files in a directory and its containing sub folders that DON’T match some file extensions.

Logic is like this:

GOTO directory
delete !(.avi, .mkv, .mp4)

Thought this would be simple enough but I have tried multiple times with no luck!

Answer 1

@echo off
for /r C:\test %%a in (*) do (
if not %%~xa==.avi (
    if not %%~xa==.mkv (
        if not %%~xa==.mp4 (    
            del /f /q "%%a"
        )
    )
)
)

Just repeat the if‘s for the extensions that you don’t want to delete.

This answer will work for a few extensions, but if you have any more you would find a better answer here.