.TH "pubsync" 3 "Sat Aug 16 2025 14:15:23" "Paho MQTT C Client Library" \" -*- nroff -*-
.ad l
.nh
.SH NAME
pubsync \- Synchronous publication example 
.PP

.PP
.nf
#include <stdio\&.h>
#include <stdlib\&.h>
#include <string\&.h>
#include "MQTTClient\&.h"

#define ADDRESS     "tcp://test\&.mosquitto\&.org:1883"
#define CLIENTID    "ExampleClientPub"
#define TOPIC       "MQTT Examples"
#define PAYLOAD     "Hello World!"
#define QOS         1
#define TIMEOUT     10000L

int main(int argc, char* argv[])
{
    MQTTClient client;
    MQTTClient_connectOptions conn_opts = MQTTClient_connectOptions_initializer;
    MQTTClient_message pubmsg = MQTTClient_message_initializer;
    MQTTClient_deliveryToken token;
    int rc;

    if ((rc = MQTTClient_create(&client, ADDRESS, CLIENTID,
        MQTTCLIENT_PERSISTENCE_NONE, NULL)) != MQTTCLIENT_SUCCESS)
    {
         printf("Failed to create client, return code %d\\n", rc);
         exit(EXIT_FAILURE);
    }

    conn_opts\&.keepAliveInterval = 20;
    conn_opts\&.cleansession = 1;
    if ((rc = MQTTClient_connect(client, &conn_opts)) != MQTTCLIENT_SUCCESS)
    {
        printf("Failed to connect, return code %d\\n", rc);
        exit(EXIT_FAILURE);
    }

    pubmsg\&.payload = PAYLOAD;
    pubmsg\&.payloadlen = (int)strlen(PAYLOAD);
    pubmsg\&.qos = QOS;
    pubmsg\&.retained = 0;
    if ((rc = MQTTClient_publishMessage(client, TOPIC, &pubmsg, &token)) != MQTTCLIENT_SUCCESS)
    {
         printf("Failed to publish message, return code %d\\n", rc);
         exit(EXIT_FAILURE);
    }

    printf("Waiting for up to %d seconds for publication of %s\\n"
            "on topic %s for client with ClientID: %s\\n",
            (int)(TIMEOUT/1000), PAYLOAD, TOPIC, CLIENTID);
    rc = MQTTClient_waitForCompletion(client, token, TIMEOUT);
    printf("Message with delivery token %d delivered\\n", token);

    if ((rc = MQTTClient_disconnect(client, 10000)) != MQTTCLIENT_SUCCESS)
        printf("Failed to disconnect, return code %d\\n", rc);
    MQTTClient_destroy(&client);
    return rc;
}

.fi
.PP