#!/bin/sh

echo -n "login:"

read name

echo -n "password:"

read passwd

if [ "$name" = "aa" -a "$passwd" = "aaa" ];then

echo "right!"

else echo "error"

fi

一。运行过程中出现过 [: missing `]'  的问题，是[ "$name" = "aa" -a "$passwd" = "aaa" ] "$name"前和"aaa"后都必须要有空格。

二。if里面的-a相当于是与，-o相当于是或。还可以用&&和||表达。

if [ "$name" = "aa" -a "$passwd" = "aaa" ];then  与

if [ "$name" = "aa" -o "$passwd" = "aaa" ];then  或

if [ "$name" = "aa" ] && [ "$passwd" = "aaa" ];then  与

if [ "$name" = "aa" ] || [ "$passwd" = "aaa" ];then  或