lt;stdio.h&gt;</span></div><div class="line"></div><div class="line"><span class="preprocessor">#include &lt;<a class="code" href="mqtt_8h.html">mqtt.h</a>&gt;</span></div><div class="line"><span class="preprocessor">#include &quot;templates/openssl_sockets.h&quot;</span></div><div class="line"></div><div class="line"></div><div class="line"><span class="keywordtype">void</span> publish_callback(<span class="keywordtype">void</span>** unused, <span class="keyword">struct</span> <a name="_a0"></a><a class="c