php怎么判断移动端还是pc端

<?php 
    function is_Mobile()
    {
        if (isset($_SERVER['Http_VIA']) && stristr($_SERVER['HTTP_VIA'], "wap")) {
            return true;
        } elseif (isset($_SERVER['HTTP_ACCEPT']) && strpos(strtoupper($_SERVER['HTTP_ACCEPT']), "VND.WAP.WML")) {
            return true;
        } elseif (isset($_SERVER['HTTP_X_WAP_PROFILE']) || isset($_SERVER['HTTP_PROFILE'])) {
            return true;
        } elseif (isset($_SERVER['HTTP_USER_AGENT']) && preg_match('/(blackberry|configuration\/cldc|hp |hp-|htc |htc_|htc-|iemobile|kindle|midp|mmp|motorola|mobile|nokia|opera mini|opera |Googlebot-Mobile|YahooSeeker\/M1A1-R2D2|Android|iphone|ipod|mobi|palm|palmos|pocket|portalmmm|ppc;|smartphone|sonyeriCSSon|sqh|spv|symbian|treo|up.browser|up.link|vodafone|windows ce|xda |xda_)/i',$_SERVER['HTTP_USER_AGENT'])) {
            return true;
        } else {
            return false;
        }
    }?>

<?php if (is_Mobile()) {
   header('Location:https://baidu.com/');
}else{
   header('Location:https://v.qq.com/');
}
?>