pubasync - Asynchronous publication example

NAME 

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NAME

pubasync − Asynchronous publication example

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "MQTTClient.h"

#if !defined(_WIN32)
#include <unistd.h>
#else
#include <windows.h>
#endif

#define ADDRESS "tcp://mqtt.eclipseprojects.io:1883"
#define CLIENTID "ExampleClientPub"
#define TOPIC "MQTT Examples"
#define PAYLOAD "Hello World!"
#define QOS 1
#define TIMEOUT 10000L

MQTTClient_deliveryToken deliveredtoken;

void delivered(void *context, MQTTClient_deliveryToken dt)
{
printf("Message with token value %d delivery confirmed0, dt);
deliveredtoken = dt;
}

int msgarrvd(void *context, char *topicName, int topicLen, MQTTClient_message *message)
{
printf("Message arrived0);
printf(" topic: %s0, topicName);
printf(" message: %.*s0, message->payloadlen, (char*)message->payload);
MQTTClient_freeMessage(&message);
MQTTClient_free(topicName);
return 1;
}

void connlost(void *context, char *cause)
{
printf("1onnection lost0);
printf(" cause: %s0, cause);
}

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 %d0, rc);
rc = EXIT_FAILURE;
goto exit;
}

if ((rc = MQTTClient_setCallbacks(client, NULL, connlost, msgarrvd, delivered)) != MQTTCLIENT_SUCCESS)
{
printf("Failed to set callbacks, return code %d0, rc);
rc = EXIT_FAILURE;
goto destroy_exit;
}

conn_opts.keepAliveInterval = 20;
conn_opts.cleansession = 1;
if ((rc = MQTTClient_connect(client, &conn_opts)) != MQTTCLIENT_SUCCESS)
{
printf("Failed to connect, return code %d0, rc);
rc = EXIT_FAILURE;
goto destroy_exit;
}

pubmsg.payload = PAYLOAD;
pubmsg.payloadlen = (int)strlen(PAYLOAD);
pubmsg.qos = QOS;
pubmsg.retained = 0;
deliveredtoken = 0;
if ((rc = MQTTClient_publishMessage(client, TOPIC, &pubmsg, &token)) != MQTTCLIENT_SUCCESS)
{
printf("Failed to publish message, return code %d0, rc);
rc = EXIT_FAILURE;
}
else
{
printf("Waiting for publication of %s0
"on topic %s for client with ClientID: %s0,
PAYLOAD, TOPIC, CLIENTID);
while (deliveredtoken != token)
{
#if defined(_WIN32)
Sleep(100);
#else
usleep(10000L);
#endif
}
}

if ((rc = MQTTClient_disconnect(client, 10000)) != MQTTCLIENT_SUCCESS)
{
printf("Failed to disconnect, return code %d0, rc);
rc = EXIT_FAILURE;
}

destroy_exit:
MQTTClient_destroy(&client);

exit:
return rc;
}

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