Better php class autoloading

php_class_autoloading.php

<?php
function load_one( $class_name )
{
    $file = 'lib1/' . $class_name . '.php';

    if( file_exists($file) )
    {
        require_once $file;
    }

}

function load_two( $class_name )
{
    $file = 'lib2/' . $class_name . '.php';

    if( file_exists($file) )
    {
        require_once $file;
    }
}

spl_autoload_register( 'load_one' );
spl_autoload_register( 'load_two' );

In PHP 5.3 you could even write

<?php
spl_autoload_register(function ($class_name) {
    $file = 'lib1/' . $class_name . '.php';

    if( file_exists($file) )
    {
        require_once $file;
    }
});

spl_autoload_register(function ($class_name) {
    $file = 'lib2/' . $class_name . '.php';

    if( file_exists($file) )
    {
        require_once $file;
    }
});