To view currently active crontab entries: $ sudo crontab -l
To enter the edit the crontab enter the following command in the terminal: $ sudo crontab -e
Note: Don't use sudo in a cron job. Instead edit root's crontab instead of your own, e.g. sudo crontab -e and then enter commands without sudo.
At the bottom of the file enter one line for each task in the following format:
Minute Hour Day of Month Month Day of Week Command
(0-59) (0-23) (1-31) (1-12 or Jan-Dec) (0-6 or Sun-Sat)
The command must use a complete link. Instead of the first five fields, one of eight special strings may appear:
| string | meaning |
|---|---|
| @reboot | Run once, at startup. |
| @yearly | Run once a year, "0 0 1 1 *". |
| @annually | (same as @yearly) |
| @monthly | Run once a month, "0 0 1 * *". |
| @weekly | Run once a week, "0 0 * * 0". |
| @daily | Run once a day, "0 0 * * *". |
| @midnight | (same as @daily) |
| @hourly | Run once an hour, "0 * * * *". |
15 16 * * * sudo python /home/pi/projects/script1.py
30 18 */5 * * sudo python /home/pi/projects/script1.py
On a default installation the cron jobs get logged to
$ /var/log/syslog
You can see just cron jobs in that logfile by running
$ grep CRON /var/log/syslog