private function process($what = null) {
        // go through each file
        $output = null;
        foreach($this->$what['intern'] as $idx => $file) {
            // get file contents
            $contents = file_get_contents($file);

            // css? fix paths
            if($what == 'css')
                $contents = $this->dilemma($contents, $this->$what['extern'][$idx]);

            // not compressed? run through algorithms
            if(strpos($file, ".min.{$what}") === false) {
                $contents = Algorithms::$what($contents, $this->_config['config'][$what]);

                // add script delimiter if js
                if($what == 'js')
                    $contents .= ";";
            }

            // add to output
            $output .= "\n" . $contents . "\n";
        }

        // strip newlines
        $output = preg_replace('#(\r\n?|\n){2,}#', "\n", $output);

        // return the compressed string
        return trim($output);
    }