Crontab usage example

20 Super Practical Crontab Use Cases

1. Execute the task every day at 02:00

　　　　0 2 * * * /bin/sh backup.sh

2. Execute tasks every day at 5:00 and 17:00

　　　　0 5,17 * * * /scripts/script.sh

3. Execute a task every minute
   Usually, we don't have a script that needs to be executed every minute (silently think of 12306--)

  　　　* * * * *  /scripts/script.sh

4. Execute the task every Sunday at 17:00

　　　　0 17 * * sun  /scripts/script.sh

5. Execute a task every 10 minutes

　　　　*/10 * * * * /scripts/monitor.sh

6. perform tasks in specific months

  　　　* * * jan,may,aug * /script/script.sh

7. perform tasks on specific days

　　　　0 17 * * sun,fri /script/scripy.sh

　　　　Execute tasks at 17:00 every Friday and Sunday

8. Run the task on the first Sunday of a month

　　　　0 2 * * sun  [ $(date +%d) -le 07 ] && /script/script.sh

9. Execute a task every four hours

　　　　0 */4 * * * /scripts/script.sh

10. Perform tasks every Monday and Sunday

　　　　0 4,17 * * sun,mon /scripts/script.sh

11. Execute a task every 30 seconds
    We have no way to execute it directly by appealing a similar example, because the minimum is 1min. But we can do it as follows.

  　　* * * * * /scripts/script.sh
  　　* * * * *  sleep 30; /scripts/script.sh

12. Multiple tasks configured in one command

  　　* * * * * /scripts/script.sh; /scripts/scrit2.sh

13. Perform a task once a year

　　　@yearly /scripts/script.sh

　　　@yearly is something like "0 0 1 1 *". It is executed in the first minute of every year, usually we can send New Year's greetings with this.

14. Perform a task once a month

　　@yearly /scripts/script.sh

15. Do a task once a week

　　@yearly /scripts/script.sh

16. Execute a task once a day

　　@yearly /scripts/script.sh

17. Execute a task every minute

　　@yearly /scripts/script.sh

18. Executed when the system restarts

　　@reboot /scripts/script.sh

19. A specific account to redirect
    cron results to If you need to send it to other users, you can do it in the following ways:

  　# crontab -l
  　MAIL=bob
  　0 2 * * * /script/backup.sh

20. Backup all cron commands to a text file
    This is a convenient and quick way to restore when we lose cron commands.
    The following is a small example of using this method to restore cron. (Just take a look~)
    First: check the current cron

　　# crontab -l
　　MAIL=rahul
　　0 2 * * * /script/backup.sh

Author: LeeLom
Link: https://www.jianshu.com/p/d93e2b177814
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