note 53782 added to function.system

What is the user that executes a bash command via the php system() function embedded in a php web page? I assume that it will be the webserver user (www-data or thinks like this). In this case how to change the user to execute correctly some scripts? e.g. if in a web page I write: <?php system('touch /root/test.txt'); ?> it is not possible if the /root directory gives no write permissions for everyone. So, how these permissions are handled via the system() function? ---- Manual Page -- http://www.php.net/manual/en/function.system.php Edit -- http://master.php.net/manage/user-notes.php?action=edit+53782 Delete: added to the manual -- http://master.php.net/manage/user-notes.php?action=delete+53782&report=yes&reason=added+to+the+manual Delete: bad code -- http://master.php.net/manage/user-notes.php?action=delete+53782&report=yes&reason=bad+code Delete: spam -- http://master.php.net/manage/user-notes.php?action=delete+53782&report=yes&reason=spam Delete: useless -- http://master.php.net/manage/user-notes.php?action=delete+53782&report=yes&reason=useless Delete: other reasons -- http://master.php.net/manage/user-notes.php?action=delete+53782&report=yes Reject -- http://master.php.net/manage/user-notes.php?action=reject+53782&report=yes Search -- http://master.php.net/manage/user-notes.php