exec() cause an infinite loop of starting requested program

OS开发者_StackOverflow中文版: Linux.

WHM, cpanel used.

PHP 5.3.2 (cli) (built: Jun 11 2010 02:25:31) Copyright (c) 1997-2010 The PHP Group Zend Engine v2.3.0, Copyright (c) 1998-2010 Zend Technologies

<?php
exec("php xyz.php");
?>

starts calling the xyz.php innumerable times. the server hangs after sometime.

calling 'php xyz.php' from the console works fine.

found the solution from

http://www.mombu.com/php/php-5-forum/t-24759-exec-or-system-et-all-cause-an-infinite-loop-of-starting-requested-program-8469354.html

<?php
exec("php-cli xyz.php");
?>

worked....