参考鸟哥linux私房菜p389
#!/bin/bash #for use: #author: jpuyy date jpuyy.com [email protected] #modified by xx at date #version: #history: #relate on: PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin export PATH echo "count down script" echo "how many time to graduate" read -p "please input your graduate time format like 20120620:" date2 date_d=$(echo $date2 | grep '[0-9]\{8\}') if [ "$date_d" == "" ]; then echo "your input is wrong" exit 1 fi declare -i date_dem=`date --date="$date2" +%s` declare -i date_now=`date +%s` declare -i date_total_s=$(($date_dem-$date_now)) declare -i date_d=$(($date_total_s/60/60/24)) if [ "$date_total_s" -lt "0" ]; then echo "you have graduated $((-1*$date_d)) days" else declare -i date_h=$(($(($date_total_s-$date_d*60*60*24))/60/60)) echo "you left $date_d days and $date_h hours." fi
执行
其实不光有倒计时功能，也可以看已发生的事件到现在多长时间了
收获：
打代码时候vim颜色提醒了标点符号，节省了很多力气
找码一定要打出来才知道掌握了多少，空想不可取，再少代码也不可复制。
用到知识：date 和 时间换算常识
root@www:/home/jpuyy/shellstudy# bash sh11.sh count down script how many time to graduate please input your graduate time format like 20120620:20120620 you left 203 days and 11 hours.
离毕业不远了啊