code: protected function hasMediaTag($strFile)
  	{
  		$return = false;
  		$fh = fopen($this->strRootDir . '/' . $strFile, 'rb');
  
  		while (($line = fgets($fh)) !== false)
  		{
  			if (strpos($line, '@media') !== false)
  			{
  				$return = true;
  				break;
  			}
  		}
  
  		fclose($fh);
  
  		return $return;
  	}
docs: Check if the file has a @media tag
  
  @param string $strFile
  
  @return boolean True if the file has a @media tag