Bash script to purge all but the last N files that match a pattern.

purge.sh

#/bin/bash
#
# Purge all but the last N files in the input list.
#
if (( $# > 1 )) ; then
    readonly NUM=$1
    shift
    readonly LIST=($*)
    readonly LEN=$(( ${#LIST[@]} - $NUM ))
    if (( LEN )) ; then
        echo "purging ${LIST[@]:0:$LEN}"
        rm -rf "${LIST[@]:0:$LEN}"
    fi
fi