Automating db backup using php and cron

I have a script that backups up my DB. I need to call the script once a night and I have a cron script that is called every 15 minutes. I updated the cron script located at

moodle\admin\cron.php.

I added to the end of the script a simple conditional check to see if the time is between a specific 16 minute interval. If it is, which it should be once a night, then include the script file that contains the backup code. Like this:

Adding code to the cron.php file

$time = date('h:i');

if($time >= '03:00' && $time <= '03:16'){
include_once('dbBackup.php');
}

I excluded the if statement initially, to be sure I could include in the cron file. Once I saw the backup file called, I put the conditional back in place. I think the cron.php file has some special magic powers that might exclude the use of a include_once call, of course not, its a script file like any other.

Consequences of updating core moodle code

I kept the backup code in the external file dbBackup.php to minimize the amount of code inserted into a core moodle file, cron.php. When I update the moodle core, this cron.php file will get sacked and I will have to put the same code back into the file. This way its only 4 lines of code. The dbBackup.php file is about 40 lines of code.

I saved the dbBackup.php file into the admin directory (for now), where the cron.php script lives. I may move it into a safer place where the files wont get sacked by upgraded the moodle core.