I need a command to remove all files from a directory (and subdir) that are under 20MB

Question

With the exception of certain file extensions. (removing junk other than subtitle files from a video directory)

Answer 1

First, run

find . -type f ! -name '*.sub' ! -name '*.srt' -size -20M -print  

to check that it mathes only file types that you want. I'm a long time unix user and I always do this before asking any command to remove anything (typos always happen at the worst possible time). Then edit the previous command line to become

find . -type f ! -name '*.sub' ! -name '*.srt' -size -20M -print0 | xargs -0 /bin/rm -f  

and run it. It should do what you want. You can repeat the ! -name '*.srt' part more times if you need to exclude more files. Be careful to include the single quotes: they are important to prevent the shell from doing filename expansion.

Answer 2

here:

find . -type f -name *.bak -size -20M -exec rm {} \;

with -name *.bak you are looking for files with extension "bak", -type f is looking for files (not directories), -size -20M give you all files smaller than 20MB (-size +20M for the reverse search of files bigger than 20MB) and with the -exec you are removing the results of this search.

Answer 3

find . -type f ! -name '*.ext' -size -20M -delete

is more easy to type and remember than anything else. You have to remember that -delete is position dependent, and deletes without further notice and trashcan.

Just be careful, backup often, and test before deleting:

find . -type f ! -name '*.ext' -size -20M