Delete all files except the newest 3 in bash script

Question

Question: How do you delete all files in a directory except the newest 3?

Finding the newest 3 files is simple:

ls -t | head -3
         


        

Answer 1

In zsh:

rm /files/to/delete/*(Om[1,-4])

If you want to include dotfiles, replace the parenthesized part with (Om[1,-4]D).

I think this works correctly with arbitrary chars in the filenames (just checked with newline).

Explanation: The parentheses contain Glob Qualifiers. O means "order by, descending", m means mtime (See man zshexpn for other sorting keys - large manpage; search for "be sorted"). [1,-4] returns only the matches at one-based index 1 to (last + 1 - 4) (note the -4 for deleting all but 3).