Linux Server Tutorials

1. Show list of all tasks

Display all cron jobs for the current user:

crontab -l

2. Add a new task

Edit your crontab file:

crontab -e

Add the following line at the end of the file to run a command every day at midnight:

0 0 * * * php /full/path/to/index.php

Replace /full/path/to/index.php with the actual path to your script.

3. Edit a task

Run:

crontab -e

Then modify the desired line in the editor.

4. Delete a task

Also via:

crontab -e

Just delete the task line and save changes.

To delete all cron jobs at once:

crontab -r

Warning: This removes all crontab entries for the user without confirmation.

Useful Examples

Every 5 minutes:

*/5 * * * * php /home/user/script.php

Every day at 6:30 AM:

30 6 * * * php /home/user/script.php

Every Monday at 7:00 AM:

0 7 * * 1 php /home/user/script.php

Log output to file:

0 0 * * * php /home/user/index.php >> /home/user/logs/cron.log 2>&1

>> appends output; 2>&1 combines stderr and stdout.

Check if cron is running

systemctl status cron

If stopped, start it:

sudo systemctl start cron

Other tips

Edit crontab for another user:

sudo crontab -u username -e

System-wide cron jobs:

• /etc/crontab
• /etc/cron.daily/
• /etc/cron.hourly/
• /etc/cron.weekly/
• /etc/cron.monthly/

Cost: UAH