PHP怎么识别系统语言或浏览器语言

<br />preg_match('/^([a-z\-]+)/i', $_SERVER['HTTP_ACCEPT_LANGUAGE'], $matches);<br />$lang = $matches[1];<br />switch ($lang) {<br />	case 'zh-cn' :<br />		//header('Location: http://cn.test.com/');<br />		echo "中国";<br />		break;<br />	case 'zh-tw' :<br />		// header('Location: http://tw.test.com/');<br />		echo "台湾";<br />		break;<br />	case 'ko' :<br />		//header('Location: http://ko.test.com/');<br />		break;<br />	default:<br />		// header('Location: http://en.test.com/');<br />		echo "英文";<br />		break;<br />}<br />