Crontab is a tool that executes a program at a fixed time in a Linux system, similar to a Task scheduler in a Windows system.
First, install the crontab
Yum Install Vixie-cron #安装
Chkconfig Crond on #设为开机启动, installing Chkconfig (yum install chkconfig) # # #设置启动方式
Service Crond Start #启动
Service Crond Stop #停止
Or
/etc/rc.d/init.d/crond Start/stop/restart/reload
/etc/rc.d/init.d/crond Reload # Non-disruptive service, reload configuration
Second, the meaning of the crontab parameter
The Cron service provides the crontab command to set the cron service , with detailed parameters as follows
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 cron service with no users
CRONTAB-E//Edit a user's cron service
Iii. set up a task plan
/home/mvp/osyunwei.sh #要自动执行的脚本程序路径
chmod +x/home/mvp/osyunwei.sh #对脚本文件添加执行权限, otherwise cannot be executed
Vi/etc/crontab #编辑配置文件, adding content on the last line
1 * * * root/home/mvp/osyunwei.sh #表示每天凌晨1点30执行备份
: wq! #保存退出
/etc/rc.d/init.d/crond Reload #重新载入crond配置文件
Crontab file Format:
minute Hour Day Month Weekday username command
minute: Minute, value is 0-59
Hour: Hour with a value of 1-23
Day: Days with a value of 1-31
Month: The value is 1-12
Weekday: Week, value 0-6 (0 for Sunday, 1 for Monday, etc.)
Username: The user to execute the program is generally set to root
Command: Program path to execute ( set to absolute path ) For example:/home/mvp/osyunwei.sh
*/2 every 2
1-6 1 to 6
1,2,3,4 1, 2, 3, 4
Detailed examples of rules attached to crontab
1, Daily 6:00 execution
0 6 * * * root/home/mvp/osyunwei.sh
2, every Saturday 4:00 to execute
0 4 * * 6 root/home/mvp/osyunwei.sh
3, every Saturday 4:05 to execute
5 4 * * 6 root/home/mvp/osyunwei.sh
4, every Saturday 4:15 to execute
4 * * 6 root/home/mvp/osyunwei.sh
5, every Saturday 4:25 to execute
4 * * 6 root/home/mvp/osyunwei.sh
6, every Saturday 4:35 to execute
4 * * 6 root/home/mvp/osyunwei.sh
7, every Saturday 5:00 to execute
5 * * 6 root/home/mvp/osyunwei.sh
8, Daily 8:40 execution
8 * * * root/home/mvp/osyunwei.sh
9, Daily 8:30 execution
8 * * * root/home/mvp/osyunwei.sh
10, every Monday to Friday, starting 11:41, every 10 minutes to perform a #值得借鉴
41,51 * * 1-5 root/home/mvp/osyunwei.sh
Or
1-59/10 12-23 * * 1-5 root/home/mvp/osyunwei.sh
11. Repeat every 2 hours, starting at 10:31 every day.
10-23/2 * * * root/home/mvp/osyunwei.sh
12, Daily 15:00 execution
0 * * * root/home/mvp/osyunwei.sh
13, starting 10:30 every day, repeat every 2 hours
10-23/2 * * * root/home/mvp/osyunwei.sh
14, Daily 15:30 execution
* * * * root/home/mvp/osyunwei.sh
15, Daily 17:50 execution
* * * * root/home/mvp/osyunwei.sh
16, Daily 8:00 execution
0 8 * * * root/home/mvp/osyunwei.sh
17, Daily 18:00 execution
0 * * * root/home/mvp/osyunwei.sh
18, Daily 8:30 execution
8 * * * root/home/mvp/osyunwei.sh
19, every day 20:30
* * * * root/home/mvp/osyunwei.sh
20, every Monday to Friday 2:00
0 2 * * 1-5 root/home/mvp/osyunwei.sh
21, every Monday to Friday 9:30
9 * * 1-5 root/home/mvp/osyunwei.sh
22, every Monday to Friday 8:00, every Monday to Friday 9:00
0 8,9 * * 1-5 root/home/mvp/osyunwei.sh
23, every day 23:59
* * * * root/home/mvp/osyunwei.sh
24, every Saturday 23:59
* * 6 root/home/mvp/osyunwei.sh
25, every day 0:30
0 * * * root/home/mvp/osyunwei.sh
26. Run every 10 minutes from Monday to Friday from 9:25 to 11:35, between 13:00 and 15:00
Sub-section writing is worth borrowing from
25,35,45,55 9 * * 1-5 root/home/mvp/osyunwei.sh
5-59/10 * * 1-5 root/home/mvp/osyunwei.sh
5,15,25,35 * * 1-5 root/home/mvp/osyunwei.sh
*/10 13-15 * * 1-5 root/home/mvp/osyunwei.sh
27. Execute once every Monday to Friday 8:30, 8:50, 9:30, 10:00, 10:30, 11:00, 11:30, 13:30, 14:00, 14:30, 5:00, respectively
30,50 8 * * 1-5 root/home/mvp/osyunwei.sh
9 * * 1-5 root/home/mvp/osyunwei.sh
*/30 10-11 * * 1-5 root/home/mvp/osyunwei.sh
* * 1-5 root/home/mvp/osyunwei.sh
0,30 14-15 * * 1-5 root/home/mvp/osyunwei.sh
28, Daily 23:50 execution
* * * * root/home/mvp/osyunwei.sh
29, Daily 10:00, 16:00 execution
0 10,16 * * * root/home/mvp/osyunwei.sh
30, Daily 5:30 execution
5 * * * root/home/mvp/osyunwei.sh
31, every Monday to Friday 9:30 to execute
9 * * 1-5 root/home/mvp/osyunwei.sh
32, every Monday to Friday 13:00 to execute
0 * * 1-5 root/home/mvp/osyunwei.sh
33, Daily 7:51 execution
Wuyi 7 * * * root/home/mvp/osyunwei.sh
34, each day 7:53, 12:40 to perform one time
7 * * * root/home/mvp/osyunwei.sh
* * * * root/home/mvp/osyunwei.sh
35, Daily 7:55 execution
7 * * * root/home/mvp/osyunwei.sh
36, each day 8:10, 16:00, 20:00 to perform one time
8 * * * root/home/mvp/osyunwei.sh
0 * * * root/home/mvp/osyunwei.sh
0 * * * root/home/mvp/osyunwei.sh
37, each day 7:57, 8:00 to perform one time
7 * * * root/home/mvp/osyunwei.sh
0 8 * * * root/home/mvp/osyunwei.sh
Crontab Plan Execution Script detailed