class Server
{
    const PORT = 8888;

    public function port()
    {
        //netstat -anp 2>/dev/null| grep 8888 |grep LISTEN |wc -l
        $shellCommand = 'netstat -anp 2>/dev/null| grep ' . self::PORT . "| grep LISTEN | wc -l";
        $result = shell_exec($shellCommand);
        if ($result != 1) {
            //程序不存在，傳送警報資訊
            echo 'At '.date('Y-m-d H:i:s') . ' service process is exit' . PHP_EOL;
        } else {
            echo 'At '.date('Y-m-d H:i:s') . ' service process is ok' . PHP_EOL;
        }
    }

}

Swoole\Timer::tick(1000, function (int $timer_id) {
    (new Server)->port();
});
 

nohup /usr/bin/php ./Server.php > ~/test.log &