__autoload()

/*
Autoload for php classes with a simple convention so you don't have to include manually files.
The convention is as follow: '_' gets converted into '/' and the strings before and after '_' become
directories or files.
For example Process_Shell class is located under directory Process and the file name that contains
the class Process_Shell is called Shell.php. The classname is Process_Process and is located into
Process/Shell.php.
 
*/
 
function __autoload($class){
    $elems = explode('_',$class);
    $path = implode('/',$elems);
    require_once($path . '.' . 'php');
}