PHP：向ios发送推送通知

$passphrase = '';
$badge = 1;
$path = base_path('path/to/certificate.pem');
$ctx = stream_context_create();
stream_context_set_option($ctx,'ssl','local_cert',$path);
stream_context_set_option($ctx,'passphrase',$passphrase);
$fp = stream_socket_client(
    'ssl://gateway.sandBox.push.apple.com:2195',$err,$errstr,60,STREAM_CLIENT_CONNECT | STREAM_CLIENT_PERSISTENT,$ctx
);

if (!$fp) {
    self::SavePush($device_token,$message,$device_id,$device_type,$user_id,"pending","normal",null);
}

//echo 'Connected to APNS' . PHP_EOL;
$body['aps'] = array(
    'alert' => $message,'badge' => $badge,'sound' => 'default'
);
$payload = json_encode($body);
$msg = chr(0) . pack('n',32) . pack('H*',$device_token) . pack('n',strlen($payload)) . $payload;
$result = fwrite($fp,$msg,strlen($msg));

//print_r($result);exit;

if (!$result) {
    self::SavePush($device_token,null,$result);
} else {
    self::SavePush($device_token,"sent",$result);
}

fclose($fp);

现在我遇到的问题是,我无法确定通知是否失败,因为$result在每种情况下都包含一个整数,成功或失败.我已经传递了一个随机数字作为标记,它返回115或65之类的整数,每次都会改变.所以！$结果不会工作.我怎么知道通知是否失败？