简单密码验证脚本(变量赋值，循环，运算，条件判断) - 曲径通幽论坛

#!/bin/bash

password="i love you"

time=0     #允许密码输入错误次数
echo -n "input password for login:"
while read answer
do
echo $answer
if [ "${answer}" = "${password}" ]; then   #因为字符串含有空格，所以这里一定要用双引号括起变量
echo "password is ok"
        exit 0
else
echo "password is wrong!"
        echo -n "input correct password:"
        time=$(($time+1))     #变量的数学运算

        if [ $time -eq 5 ]; then
echo "too many input"
                exit
        fi

fi
done

exit 0