#!/bin/bash#將第一個命令行參數傳遞給變量a,第二個命令行參數傳遞給變量ba=$1b=$2#判斷a或者b變量是否為空，只要有一個為空就打印提示語句并退出if [ -z $a ] || [ -z $b ]then    echo "please enter 2 no"    exit 1#判斷a和b的大小，并根據判斷結果打印語句fiif [ $a -eq $b ] ; then    echo "number a = number b"else if [ $a -gt $b ]    then        echo "number a>number b"    elif [ $a -lt $b ]        then            echo "number a<number b"    fifi