CodeIgniter autoload classes

ci-autoload

/*
|--------------------------------------------------------------------------
| Autoload Custom Controllers
|--------------------------------------------------------------------------
| http://stackoverflow.com/questions/21351808/codeigniter-extending-controller-controller-not-found
|
| Add this to the bottom of /config/config.php
|
| As long as your library is prefixed with "MY_" and lives in the /core/ folder, this will
| autoload that library when you extend without having to otherwise include it.
|
|
*/
function __autoload($class) {
    if (substr($class,0,3) !== 'CI_') {
        if (file_exists($file = APPPATH.'core/'.$class.".php")) {
            include $file;
        }
    }
}