ockfd == NULL) {</div><div class="line">        exit_example(EXIT_FAILURE, sockfd, NULL);</div><div class="line">    }</div><div class="line"></div><div class="line">    <span class="comment">/* setup a client */</span></div><div class="line">    <span class="keyword">struct </span><a name="_a1"></a><a class="code" href="structmqtt__client.html">mqtt_client</a> client;</div><div class="line">    uint8_t sendbuf[2048]; <span class="comment">/* sendbuf should be large enough to hold multiple whole mqtt messag