shell实现猜数字的小游戏

#/*************************************************************************
#    > File Name: guessgame.sh
#    > Author: liyong
#    > Mail: 2550702985@qq.com
#    > Created Time: 2017-03-22 01:57
#    > Last modified: 2017-03-22 01:57
randNum=$(date +%s%N)
let luckNum=${randNum:0-1:1}
echo $luckNum
let num=luckNum+1
while [ $luckNum -ne $num ];