Onion Omega MQTT publisher client

mqttclient.php

<?php

class MqttClient
{
    private $server;
    private $port;
    private $user;
    private $password;

    public function __construct($server, $port = 1883, $user = '', $password = '')
    {
       $this->server = $server;
       $this->port = $port;
       $this->user = $user;
       $this->password = $password;
    }

    public function publish($topic, $payload)
    {
       exec(sprintf('mosquitto_pub -h %s -p %d -u %s -P %s -t "%s" -m "%s"', $this->server, $this->port, $this->user, $this->password, $topic, $payload));
    }
}