1. 加法器

#!/bin/bash

#

#echo -n "something"                       #-n,为不换行

read -p "Please Input two shuzi:" A B      #read格式,输入变量时,read后要加空格,A,B才能相应的接收到值

SUM=$[$A+$B]

echo "The plus two shuzi is $SUM"