PHP Cronjobalternative

cronjob_alternative.php

ignore_user_abort(1); // run script in background 
set_time_limit(0); // run script forever 
$interval=60*15; // do every 15 minutes... 
do{ 
   // add the script that has to be ran every 15 minutes here 
   // ... 
   sleep($interval); // wait 15 minutes 
}while(true);