public function input($filename, $input)
    {
        if (substr($filename, strlen($this->_settings['ext']) * -1) !== $this->_settings['ext']) {
            return $input;
        }
        $filename = preg_replace('/ /', '\\ ', $filename);
        $bin = $this->_settings['sass'] . ' ' . $filename;
        $return = $this->_runCmd($bin, '', array('PATH' => $this->_settings['path']));
        return $return;
    }