判断用户输入YES或NO

#!bin/bash
#作者:liusingbon
#功能:判断用户输入的是 Yes 或 NO
read -p "Are you sure?[y/n]:" sure
case $sure in
y|Y|Yes|yes|YES)
       echo "you enter $sure";;
n|N|NO|no)
       echo "you enter $sure";;
*)
       echo "error";;
esac