Autoloader for CodeIgniter

config.php

function __autoload($class)
{
    if (strpos($class, 'CI_') !== 0)
    {
        if (file_exists($file = APPPATH . 'core/' . $class . EXT))
        {
            include $file;
        }
        elseif (file_exists($file = APPPATH . 'libraries/' . $class . EXT))
        {
            include $file;
        }
    }
}