#! /bin/bash

read -p "pelease input your name:" name

read -p "pleaase input your password:" passwd

if [ $name == "root" -a $passwd == "123" ]; then

    echo "登录成功！"

else

    echo "登录失败！"

fi

if [[ $name == "root" && $passwd == "123" ]]; then

       echo "Login pass"

else

    echo "Login fail"

fi    

输出结果：
pelease input your name:root
pleaase input your password:123
登录成功！
Login pass

#! /usr/bin/ksh

echo "pelease input your name:"

read name

read passwd?"pleaase input your password: "

if [[ $name == "root" && $passwd == "123" ]]; then

       echo "Login pass"

else

    echo "Login fail"

fi    

# ./learn_shell.save

pelease input your name:    （这个地方有回车）

root

pleaase input your password: 123

Login pass