my-docs/Security & Networking/CronJob/CronJob.md

 .---------------- minute (0 - 59)
 |  .------------- hour (0 - 23)
 |  |  .---------- day of month (1 - 31)
 |  |  |  .------- month (1 - 12) OR jan,feb,mar,apr ...
 |  |  |  |  .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat
 |  |  |  |  |
 *  *  *  *  * user-name command to be executed

Here are some examples to illustrate different cron job schedules:

Example 1: Run at 12:55 every day

55 12 * * * root hi

This command runs hi as the root user every day at 12:55.

Example 2: Run every minute

*/1 * * * * root hi

This command runs hi as the root user every minute.

Example 3: Run every 2 minutes

*/2 * * * * root hi

This command runs hi as the root user every 2 minutes.

Example 4: Run at specific minutes

10,20,30 10 * * * root hi

This command runs hi as the root user at 10:10, 10:20, and 10:30.

Example 5: Run after every reboot

@reboot root hi

This command runs hi as the root user after system reboot.