how to test a cronjob execution via server with php

how to test a cronjob execution via server with php

Is there a way to run cronjob via php? but not by open the URL of the
script, like if is really executed by the server.
I need this to test my cronjob.php file because if i open the URL of the
script everything work, but via server cronjob don't!
For example with the function exec? with what url?
<?php echo( exec( ) ); ?>
the url of my cronjo is:
/usr/bin/php -q /home/content/**/***/html/app/script2/cronjobs.php