/**
 * 判断用户请求设备是否是移动设备
 * @return bool
 */
function isMobile() {

    //如果有HTTP_X_WAP_PROFILE则一定是移动设备
    if (isset($_SERVER['HTTP_X_WAP_PROFILE'])) {
        return true;
    }

    //如果via信息含有wap则一定是移动设备,部分服务商会屏蔽该信息
    if (isset($_SERVER['HTTP_VIA']) && stristr($_SERVER['HTTP_VIA'], 'wap')) {
        return true;
    }

    //野蛮方法,判断手机发送的客户端标志,兼容性有待提高
    if (isset($_SERVER['HTTP_USER_AGENT'])) {

        $clientKeywords = ['nokia','sony','ericsson','mot','samsung','htc','sgh','lg','sharp','sie-','philips','panasonic','alcatel','lenovo','iphone','ipod','blackberry','meizu','android','netfront','symbian','ucweb','windowsce','palm','operamini','operamobi','openwave','nexusone','cldc','midp','wap','mobile'];

        //从HTTP_USER_AGENT中查找手机浏览器的关键字
        if (preg_match("/(".implode('|', $clientKeywords).")/i", strtolower($_SERVER['HTTP_USER_AGENT']))) {
            return true;
        }
    }

    //协议法,因为有可能不准确,放到最后判断
    if (isset($_SERVER['HTTP_ACCEPT'])) {
        //如果只支持wml并且不支持html那一定是移动设备
        //如果支持wml和html但是wml在html之前则是移动设备
        if ((strpos($_SERVER['HTTP_ACCEPT'], 'vnd.wap.wml') !== false) && (strpos($_SERVER['HTTP_ACCEPT'], 'text/html') === false || (strpos($_SERVER['HTTP_ACCEPT'], 'vnd.wap.wml') < strpos($_SERVER['HTTP_ACCEPT'], 'text/html')))) {
            return true;
        }
    }

    return false;
}

转载自:
php判断设备访问来源