#!/bin/bash
## Time-stamp: <2000-06-06 18:43:03 ecl>

## Remove old backup files whose originals do not exist anymore or were
## not modified since a given amount of time.
## Intended to run as a cron job.
## Require the GNU file utilities.

## THIS FILE IS IN THE PUBLIC DOMAIN.  USE AT YOUR OWN RISK!

backup_files=`find . -xdev -type f \( -name '*~' -o -name '.*~' \) -print`

time_stamp_file=/tmp/.clean-backups_$$
touch --time=modify --date $(date --date '3 months ago' +'%Y%m%d') $time_stamp_file

for backup in $backup_files; do
    case $backup in
        *.~*~)
            orig=${backup%.\~*\~}
            ;;
        *~*~)
            orig=${backup%\~*\~}
            ;;
        *~)
            orig=${backup%\~}
            ;;
        *)
            echo Something went wrong here: \"$backup\"
            orig=$backup        # so that the backup won't be removed.
            ;;
    esac

    if [ ! -f "$orig" -o "$orig" -ot "$time_stamp_file" ]; then
        echo rm $backup \($orig\)
        old_backups="$old_backups $backup"
    fi
done

rm -f $time_stamp_file $old_backups