Does this site look plain?

This site uses advanced css techniques

Nearly all UNIX/Linux administrators use the cron facility to schedule jobs to run at certain times: logfile rotation at midnight; Cacti or MRTG network monitoring polls every 5 minutes; and so on. This facility has been a useful part part of UNIX since the beginning.

The crontab file contains one line per job, with the first five fields specifying the times the job should run, followed by the job command line itself. An example:

crontab
*/5 * * * * php /var/www/html/cacti/poller.php > /dev/null 2>&1

The time parameters are covered well by the cron documentation, so we shall not cover them here. Instead, we're turning our attention to the command itself.

Our premise:
One ought not include direct commands in a crontab; wrap them in a script instead.

By wrapping the commands in a script, one has much more control over the cron environment, it's much easier to fine-tune the behavior, and it leaves much better clues for a maintainer that a command