Special Topics - Running Cron Jobs
General Info ¶
Some web applications may require that certain actions are automatically executed by
predefined schedule. In UNIX-like operating systems such actions are managed by the
cron
daemon.
Periodically executed actions are described by means of special instructions added to
crontab configuration files. Each instruction must contain a specially formatted description
and the command to be executed as shown below:
* * * * * executed command
- - - - -
| | | | |
| | | | ----- Day of the week (0 - 7) (Important: Sunday = 0 or 7)
| | | ------- Month (1 - 12)
| | --------- Date (1 - 31)
| ----------- Hour (0 - 23)
------------- Minute (0 - 59)
Examples of cron job descriptions:
# Executed every 5 minutes
*/5 * * * * $HOME/bin/every5min
# Executed every day at 06:30
30 6 * * * $HOME/bin/daily
# Executed each hour on working days
0 * * * 1-5 $HOME/bin/hourly
# Executed at 01:00 from Saturday to Sunday
0 1 * * 7 $HOME/bin/weekly
# Executed at 01:00 every 1st and 15th day of each month
0 1 1,15 * * $HOME/bin/montly
To make sure your application performs such operations you have to create firstly a
CronController
(you nay give any name you want), where you write executable code.
Then you have to set up a cron job in your Hosting Control Panel.
Setting up a cron job in Site5.com Control Panel ¶
Setting up a cron job in cPanel ¶
Two options to perform cron jobs ¶
You may define batch or non-batch options to perform the cron jobs.
The recommended way to run cron code is to set up a cronjob if you run a Unix/Linux server.
If for any reason you can't run a cronjob on your server, you can choose the non-batch option
to have cron code is running by the script itself: in this case cron code will be run each time
someone access your home page. Such option is called "pesudo" oir "non-batch".