#!/bin/bashaction=$(echo $1 | tr a-z A-Z)file=$2game="opencity.save"bak="opencity.bak"usage(){ echo "$0 save|load file"}case $action in LOAD) if [ -e $file.save ] then [ -e $bak ] && rm $bak mv $game $bak mv $file.save $game else usage fi ;; SAVE) [ -e $file.save ] && "$file.save exists" && exit 1 cp $game $file.save ;; *) usageesac