Linux under crontab simple use

0. Personal tagsCaicongyangHttp://blog.csdn.net/caicongyang1.crontab

Crontab is a scheduled task under Linux, which is also available in sping

2. Basic format

* * * * * command
Time-sharing Weekly command

3. Command

Usage:  crontab [-u user] file        crontab [-u user] [-e |-l |-r]                (default operation is replace, per 1003.2) 
   -e      (Edit user ' s crontab)-        L (      list user ' s crontab)-        r      (delete user's crontab)      -I ( Prompt before deleting user ' s crontab)      -S (selinux context)

crontab–u//Set a user's Cron service, which is usually required by the root user when executing this command
crontab–l//list details of a user cron service
crontab–r//Delete a user's cron service
crontab–e//Edit a user's cron service
crontab filename//with filename as the crontab task list file and load
For example, root to view your cron settings: Crontab–u root–l
again, for example, Root wants to delete Fred's cron settings: Crontab–u fred–r
when editing the cron service, the edited content has some formatting and conventions, input: Crontab–u root–e

4. Restart

Modified crontab requires a reboot, and the following commands provide a view of the status of the crontab and the restart

#service crond status#service Crond Restart

5.

#每天早上6点10分
6 * * * Date
#每两个小时
0 */2 * * * Date
#晚上11点到早上8点之间每两个小时, 8 in the morning.
0 23-7/2,8 * * * Date
#每个月的4号和每个礼拜一到礼拜三的早上11点
0 4 * 1-3 date
#1月1日早上4点
0 4 1 1 * Date

* * * * */usr/local/etc/rc.d/lighttpd restart

The above example shows that 21:30 restarts Apache per night.

4 1,10,22 * */USR/LOCAL/ETC/RC.D/LIGHTTPD restart
The above example shows that 4:45 restarts Apache on the 1, 10, and 22nd of the month.

1 * * 6,0/USR/LOCAL/ETC/RC.D/LIGHTTPD restart
The above example shows that 1:10 restarts Apache every Saturday and Sunday.

0,30 18-23 * * */usr/local/etc/rc.d/lighttpd restart
The above example shows that Apache restarts every 30 minutes from 18:00 to 23:00 every day.

0 * * 6/USR/LOCAL/ETC/RC.D/LIGHTTPD restart
The above example shows the restart of Apache every Saturday at 11:00am.

* */1 * * * */usr/local/etc/rc.d/lighttpd restart
Restart Apache every hour

* 23-7/1 * * * */usr/local/etc/rc.d/lighttpd restart
From 11 o'clock to 7 in the morning, restart Apache every hour.

0 4 * mon-wed/usr/local/etc/rc.d/lighttpd restart
4th per month with 11-point restart from Monday to Wednesday Apache

0 4 1 Jan */usr/local/etc/rc.d/lighttpd restart
4-point restart of Apache on January 1

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Linux under crontab simple use