CI_URI::_parse_request_uri PHP Method

    protected function _parse_request_uri()
    {
        if (!isset($_SERVER['REQUEST_URI'], $_SERVER['SCRIPT_NAME'])) {
            return '';
        }
        // parse_url() returns false if no host is present, but the path or query string
        // contains a colon followed by a number
        $uri = parse_url('http://dummy' . $_SERVER['REQUEST_URI']);
        $query = isset($uri['query']) ? $uri['query'] : '';
        $uri = isset($uri['path']) ? $uri['path'] : '';
        if (isset($_SERVER['SCRIPT_NAME'][0])) {
            if (strpos($uri, $_SERVER['SCRIPT_NAME']) === 0) {
                $uri = (string) substr($uri, strlen($_SERVER['SCRIPT_NAME']));
            } elseif (strpos($uri, dirname($_SERVER['SCRIPT_NAME'])) === 0) {
                $uri = (string) substr($uri, strlen(dirname($_SERVER['SCRIPT_NAME'])));
            }
        }
        // This section ensures that even on servers that require the URI to be in the query string (Nginx) a correct
        // URI is found, and also fixes the QUERY_STRING server var and $_GET array.
        if (trim($uri, '/') === '' && strncmp($query, '/', 1) === 0) {
            $query = explode('?', $query, 2);
            $uri = $query[0];
            $_SERVER['QUERY_STRING'] = isset($query[1]) ? $query[1] : '';
        } else {
            $_SERVER['QUERY_STRING'] = $query;
        }
        parse_str($_SERVER['QUERY_STRING'], $_GET);
        if ($uri === '/' or $uri === '') {
            return '/';
        }
        // Do some final cleaning of the URI and return it
        return $this->_remove_relative_directory($uri);
    }