#!/bin/sh usage() {     echo "RemoveBroken 0.1, a shell script to remove broken link files."     echo "License: MIT, (c) chenzhiqiang"     echo "Usage:"     echo "  $0 --help           print this help."     echo "  $0 --path PATH      broken links under this PATH will be removed."     echo "  $0 --stdin          read PATHs from stdin."     echo "  $0                  same as $0 --stdin." } fromStdin() {     while [ 1==1 ]     do         read         [ "$REPLY" != "" ] || exit 0         [ ! -L $REPLY -o -e $REPLY ] || unlink $REPLY     done } fromPath() {     find $2 | $0 --stdin } if [ $# = 0 ] then     usage     fromStdin     exit 0 fi case $1 in --stdin)     fromStdin --path)     find $2 | $0 --stdin --help)     usage *)     echo "RemoveBroken: unknown usage."     usage esac