Cron

Scheduled tasks in a linux environment are handled by the cron daemon. The daemon is already running on your system.

To set up your own cron jobs, create a file called crons.cron.

$ sudo nano -w crons.cron

The example below calls a script called dbbackup every day at 3am, calls a php file called logimport every minute, and performs a clamav virus scan of the web root, tmp and home directories excluding the warpath folder at 8am on Sundays.

#Min	Hour	Day	Month	DOW
0	3	*	*	*	/usr/bin/dbbackup
*/1	*	*	*	*	/usr/bin/php -q /var/www/localhost/htdocs/logimport.php > /dev/null
0	8	*	*	0	/usr/bin/clamscan -r --quiet --remove --no-summary -i -l /var/log/clamav/clamscan.log /var/www/localhost/htdocs/ /tmp /home --exclude-dir=/home/gr0x0rd/warpath

To add these to the cron schedule,

$ sudo crontab //path/to/crons.cron

To stop the cron jobs in order to edit or change them,

$ sudo crontab -r

Use nano to alter your crons.cron file, then use the command above to restart the tasks.