To edit the crontab of the current user:
$ crontab -e
To display the crontab of the current user:
$ crontab -l
To remove the crontab of the current user:
$ crontab -r
Basic file format:
* * * * * command to be executed
- - - - -
| | | | |
| | | | +----- day of week (0 - 6) (Sunday=0)
| | | +------- month (1 - 12)
| | +--------- day of month (1 - 31)
| +----------- hour (0 - 23)
+------------- min (0 - 59)
Expressions
1,2,3 list of several values (comma-separated)
1-3 list of consecutive values (dash)
*/2 step value (every N)
Examples
* 12 10-16/2 * * backup.sh
* 12 10,12,14,16 * * backup.sh
Runs backup.sh at noon on the 10th, 12th, 14th, and 16th of each month
*/15 9-17 * * * connection.test
Runs connection.test every 15 mins between the hours or 9am and 5pm
Notes:
* Doesn't load your bash.rc.
* Different Path.
* Use full, absolute paths.
* Sends email with output from each run (only way to debug). sSMTP is simple
emailer.
* Logs to syslog (only indicates that entry was run, no output).
