Shell 面试题 -- 打印用户自定义乘法表

[root@wan day5]# vim lx2.sh
#!/bin/bash
########################################
#File Name: lx2.sh
#Version: V1.0
#Author: WanQiang
#Email: 2794411809@qq.com
#Oranization: https://me.youkuaiyun.com/XY0918ZWQ
#Cleated Time: 2021-04-24 23:30:26
#Description: 
########################################

# 用户自定义打印乘法表

while true
do
	read -p "input number:" n
	if [ $n -le 9 ]
	then
		for ((i=1;i<=9;i++))
		do
			#let res=$n*$i
			#res=$((n*i))
			#res=`expr $n \* $i`
			res=$[n*i]
			echo "$n * $i = $res"

			#echo "$n * $i = `echo $((n*i))`"
			#echo "$n * $i = `echo $[n*i]`"
			#echo "$n * $i = `expr $n \* $i`"
		done
		break
    else
		echo "请输入一个整数..."
	fi
done