$_SERVER['HTTP_USER_AGENT'];
ua即请求头里的user-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.102 Safari/537.36
可以用来判断浏览器类型，微信里可以获取微信版本

public function getOS($id)
    {
        $ua = $_SERVER['HTTP_USER_AGENT'];//这里只进行IOS和Android两个操作系统的判断，其他操作系统原理一样
        if (strpos($ua, 'Android') !== false) {//strpos()定位出第一次出现字符串的位置，这里定位为0
            preg_match("/(?<=Android )[\d\.]{1,}/", $ua, $version);
            $platform['os_platform'] = 'Android';
            $platform['os_version'] = $version[0];
            //echo 'Platform:Android OS_Version:'.$version[0];
        } elseif (strpos($ua, 'iPhone') !== false) {
            preg_match("/(?<=CPU iPhone OS )[\d\_]{1,}/", $ua, $version);
            $platform['os_platform'] = 'iPhone';
            $platform['os_version'] = str_replace('_', '.', $version[0]);
            echo 'Platform:iPhone OS_Version:'.str_replace('_', '.', $version[0]);
        } elseif (strpos($ua, 'iPad') !== false) {
            preg_match("/(?<=CPU OS )[\d\_]{1,}/", $ua, $version);
            $platform['os_platform'] = 'iPad';
            $platform['os_version'] = str_replace('_', '.', $version[0]);
            //echo 'Platform:iPad OS_Version:'.str_replace('_', '.', $version[0]);
        } else{
            $platform['os_platform'] = 'unknown';
            $platform['os_version'] = 'unknown';
        }

        $platform['user_id'] = $id;
        $is_platform_record = RecordPlatformModel::query()->where('user_id',$platform['user_id'])->first();
        if ($is_platform_record) {
            $platform_record = RecordPlatformModel::query()->where('user_id',$platform['user_id'])->update($platform);
        } else {
            $platform['created_at'] = date('Y-m-d H:i:s');
            $platform_record = RecordPlatformModel::query()->insert($platform);
        }
    }