2019年8月学习日记

2019.08.05

1.crontab:Linux一个定时守护进程,在固定的间隔时间执行指定的系统指令或 shell script脚本。

//1.编辑当前用户的crontab中定时任务
crontab -e

//crontab中的内容
 Edit this file to introduce tasks to be run by cron.
#
# Each task to run has to be defined through a single line
# indicating with different fields when the task will be run
# and what command to run for the task
#
# To define the time you can provide concrete values for
# minute (m), hour (h), day of month (dom), month (mon),
# and day of week (dow) or use '*' in these fields (for 'any').#
# Notice that tasks will be started based on the cron's system
# daemon's notion of time and timezones.
#
# Output of the crontab jobs (including errors) is sent through
# email to the user the crontab file belongs to (unless redirected).
#
# For example, you can run a backup of all your user accounts
# at 5 a.m every week with:
# 0 5 * * 1 tar -zcf /var/backups/home.tgz /home/
#
# For more information see the manual pages of crontab(5) and cron(8)
#
# m h  dom mon dow   command
//每一分钟都执行脚本/home/hungxum/shell/record_date.sh
//分 时 日 月 周 command
* * * * * sh /home/hungxum/shell/record_date.sh

//2.重启cron服务
sudo service cron restart