Magento – view entire system config – system.xml :

In Magento modules, system.xml file is used to create admin configuration tabs and options. Magento’s great feature allows developers to create advanced configurable modules in a little time. At the run time Magento collects all the xml files and group them into a single file.
To view the system.xml file simply paste this code snippet in any controllers and run it. A large xml will be open.

<?php

 //header('Content-Type: text/plain');

  header('Content-Type: text/xml');

   echo $config = Mage::getConfig()

    ->loadModulesConfiguration('system.xml')

     ->getNode()

     ->asXML();

    exit();

    ?>