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 $ find . -name '*' -type f -not -path '*.mp3'

Nov. 23, 2020, 10:21 p.m.sandreas

Explanation

Find is normally used to positively match a pattern, so find . -name '*.mp3' -type f will match every mp3 file in the current folder and its subfolders.

If you would like to exclude something from these matches, you could use the addition -not -path '<exclude pattern>', which I find much easier than using a pipe with | grep -v.

find . -name '*' -type f -not -path '*.mp3'