#!/bin/sh# Like mv $1 $2, but if the files are the same, just delete $1.# Status is zero if successful, nonzero otherwise.usage="$0: usage: $0 SOURCE DEST"case $# in2) ;;*) echo "$usage" >&2; exit 1;;esacfor arg in "$1" "$2"; docase $arg in-*) echo "$usage" >&2; exit 1;;esacdoneif test -r "$2" && cmp -s "$1" "$2"; thenrm -f "$1"elsemv -f "$1" "$2"fi