Paho MQTT C Client Library: Synchronous publication example

| Paho MQTT C Client Library

Synchronous publication example
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "MQTTClient.h"
#define ADDRESS "tcp://mqtt.eclipseprojects.io: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;
}
MQTTClient.h
MQTTClient_disconnect
int MQTTClient_disconnect(MQTTClient handle, int timeout)
MQTTClient_deliveryToken
int MQTTClient_deliveryToken
Definition: MQTTClient.h:262
MQTTClient
void * MQTTClient
Definition: MQTTClient.h:251
MQTTClient_waitForCompletion
int MQTTClient_waitForCompletion(MQTTClient handle, MQTTClient_deliveryToken dt, unsigned long timeout)
MQTTClient_create
int MQTTClient_create(MQTTClient *handle, const char *serverURI, const char *clientId, int persistence_type, void *persistence_context)
MQTTClient_message_initializer
#define MQTTClient_message_initializer
Definition: MQTTClient.h:332
MQTTClient_connect
int MQTTClient_connect(MQTTClient handle, MQTTClient_connectOptions *options)
MQTTCLIENT_SUCCESS
#define MQTTCLIENT_SUCCESS
Definition: MQTTClient.h:132
MQTTClient_publishMessage
int MQTTClient_publishMessage(MQTTClient handle, const char *topicName, MQTTClient_message *msg, MQTTClient_deliveryToken *dt)
MQTTClient_destroy
void MQTTClient_destroy(MQTTClient *handle)
MQTTClient_connectOptions_initializer
#define MQTTClient_connectOptions_initializer
Definition: MQTTClient.h:982
MQTTCLIENT_PERSISTENCE_NONE
#define MQTTCLIENT_PERSISTENCE_NONE
Definition: MQTTClientPersistence.h:74
MQTTClient_connectOptions
Definition: MQTTClient.h:825
MQTTClient_connectOptions::cleansession
int cleansession
Definition: MQTTClient.h:870
MQTTClient_connectOptions::keepAliveInterval
int keepAliveInterval
Definition: MQTTClient.h:848
MQTTClient_message
Definition: MQTTClient.h:272
MQTTClient_message::qos
int qos
Definition: MQTTClient.h:295
MQTTClient_message::retained
int retained
Definition: MQTTClient.h:314
MQTTClient_message::payload
void * payload
Definition: MQTTClient.h:281
MQTTClient_message::payloadlen
int payloadlen
Definition: MQTTClient.h:279