CentOs 7.0 implements timed tasks (regular access to Web pages)

1, CRONTAB-E, enter the editing interface
2, Input/2 * * * * * curl http://www.baidu.com, means every two minutes to visit the Web page
3, save exit, then service Crond Start Services
4, Chkconfig Crond on set to boot from
5,
Basic format:
* * * * command
Time-sharing and Lunar Week command
The 1th column represents minutes 1~59 per minute or/1
The 2nd column represents the hour 1~23 (0 for 0 points)
The 3rd column represents the date 1~31
The 4th column represents the month 1~12
The 5th list of the week 0~6 (0 for Sunday)

* * * */usr/local/etc/rc.d/lighttpd restart
The above example shows the 21:30 restart Apache per night

Crond does not support accurate to second