Linux Crontab command

Install crontab:

yum install crontabs

Basic cron service control command:

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1. /sbin/service crond start //Start the service
3. /sbin/service crond stop //Close service
5. /sbin/service crond restart //Restart service
7. / sbin/service crond reload //Reload the configuration

Check the crontab service status: service crond status

Manually start the crontab service: service crond start

Check whether the crontab service has been set to start at boot. Execute command: ntsysv

Add automatic startup at boot: chkconfig --level 35 crond on

If you want to know more about the chkconfig --level command, http://www.cnblogs.com/panjun-Donet/archive/2010/08 /10/1796873.html Explain in more detail

crontab command introduction

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1. Function description: Set timer.
5. Syntax: crontab [-u ][Configuration file] or crontab [-u ][-elr]
9. Additional explanation: cron is a resident service that provides a timer function that allows users to execute preset instructions or programs at a specific time. As long as the user can edit the timer's configuration file, the timer function can be used. The configuration file format is as follows:
11. Minute Hour Day Month DayOFWeek Command
15. Parameters:
17. -e Edit this The user's timer settings.
19. -l List the timer settings for this user.
21. -r Delete the timer settings for this user.
23. -u Specify the user name to set the timer.

crontab format

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1. Basic format:
3. * * *
7. The first column represents minutes 1 to 59. Each minute is represented by * or */1
9. The second column represents hours 1 to 23 (0 represents 0 o'clock)
11. 3 columns represent the days 1 to 31
13. The 4th column represents the months 1 to 12
15. The 5th column identifies the week 0 to 6 (0 means Sunday)
17. The command to run in column 6
21. # Use the hash sign to prefix a comment
23. # +———— - minute (0 – 59)
25. # | +————- hour (0 – 23)
26. # | | +————- day of month (1 – 31)
28. # | | | +——- month (1 – 12)
29. 0 – 7) ( Sunday=0 or
30. 7)
32. # | | |
33. mand to be executed crontab file Some examples:
34. code
1. 30 21 * * * /etc/init.d/nginx restart
2. Every night 21
3. :30Restart nginx.
6. 45
7. 41 ,10,22 * * /etc/init. d/nginx restart
8. Every month 1
9. , 10, 22 on 4 : 45Restart nginx.
12. 10
13. 1 * * 6,0 /etc/init.d/nginx restart
14. Every Saturday and Sunday 1
15. : 10Restart nginx.
18. 0
19. ,3018 -23 * * * /etc/init.d/nginx restart
20. Every day 18
21. : 00 to 23 : Every between 00 30Restart nginx.
24. 0
25. 23 * * 6 /etc/init.d/nginx restart
26. Every Saturday 11
27. : 00 pm restart nginx.
30. * */1
31. * * * /etc/init.d/nginx restart
32. Restart nginx every hour
35. * * * /etc/init.d/nginx restart
37. Restart nginx every hour between 11 and morning7
38. 0
39. 11 4 * mon-wed /etc/init.d/nginx restart
The
41. 4 of every month and every Monday to Wednesday
42. 11 points Restart nginx
43. 1 jan * /etc/init.d/nginx restart
45. Restart nginx at 4 on January 1st
*/
49. 3 0 * * * * /usr/sbin/ntpdate 210.72.145.20
51. Synchronize time every half hour
52. Apply to thinkphp

First you have to write the function code to be executed regularly into Action. Or you can use the URL to access it and then execute it.

For example, I put the update code that periodically traverses the order every day to see if there is a transaction volume under Order/update_status.

And my project access address is www.jieqinwang.com, that is: the code execution path of this function is: http://www.jieqinwang.com/Order/update_status

After you get this path, you can go liunx went to configure cron.

crontab -e to enter the task list.

Press the I key to enter edit mode, and then add a task.

For example, if I want to execute the code I just wrote every day at 12 noon

, just add a new line 0 12 * * * * curl http://www.jieqinwang.com/Order/update_status

Then press the Esc key to exit the editing mode, then type: wq and press Enter. Save and exit.

In this way we have added a scheduled task. You can use crontab -l to check whether the task list already contains it.

The last step, because adding it like this may not take effect immediately. We just need to restart the cron service.

Restart service command: /sbin/service crond restart

Original link: http://164418960.iteye.com/blog/2170536





The above introduces the Linux Crontab command, including the relevant content. I hope it will be helpful to friends who are interested in PHP tutorials.