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

This uses find instead of ls with a Schwartzian transform.

find . -type f -printf '%T@\t%p\n' |
sort -t $'\t' -g |
tail -3 |
cut -d $'\t' -f 2-

find searches the files and decorates them with a time stamp and uses the tabulator to separate the two values. sort splits the input by the tabulator and performs a general numeric sort, which sorts floating point numbers correctly. tail should be obvious and cut undecorates.

The problem with decorations in general is to find a suitable delimiter, which is not part of the input, the file names. This answer uses the NULL character.