Sample MQTT program - simple send and receive

Dependencies:   C12832 MQTT

Fork of HelloMQTT by MQTT


main_linux.cpp@ 3:7a6a899de7cc

File content as of revision 8:a3e3113054a1:

 * Copyright (c) 2014 IBM Corp.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v1.0 which accompany this distribution.
 * The Eclipse Public License is available at
 * and the Eclipse Distribution License is available at
 * Contributors:
 *    Ian Craggs - initial API and implementation and/or initial documentation
  This is a sample program to illustrate the use of the MQTT Client library
  on Linux.  The Client class requires two classes which mediate
  access to system interfaces for networking and timing.  As long as these two
  classes provide the required public programming interfaces, it does not matter
  what facilities they use underneath. In this program, they use the Linux
  system libraries.

#if defined(LINUX)

#include "LinuxMQTT.h"
#include "LinuxIPStack.h"
#include "MQTTClient.h"

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/select.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>

#include <stdlib.h>
#include <string.h>
#include <signal.h>


int arrivedcount = 0;

void messageArrived(MQTT::Message* message)
	printf("Message %d arrived: qos %d, retained %d, dup %d, packetid %d\n", 
		++arrivedcount, message->qos, message->retained, message->dup, message->id);
    printf("Payload %.*s\n", message->payloadlen, (char*)message->payload);

int connect(MQTT::Client<IPStack, Countdown>::connectionLostInfo* info)
    const char* hostname = "localhost"; //"";
    int port = 1883;
    printf("Connecting to %s:%d\n", hostname, port);
    int rc = info->network->connect(hostname, port);
	if (rc != 0)
	    printf("rc from TCP connect is %d\n", rc);
    MQTTPacket_connectData data = MQTTPacket_connectData_initializer;       
    data.MQTTVersion = 3;
    data.clientID.cstring = (char*)"mbed-icraggs";
    rc = info->client->connect(&data);
	if (rc != 0)
	    printf("rc from MQTT connect is %d\n", rc);
    return rc;

int main(int argc, char* argv[])
    IPStack ipstack = IPStack();
    float version = 0.3;
    const char* topic = "mbed-sample";
    printf("Version is %f\n", version);
    MQTT::Client<IPStack, Countdown> client = MQTT::Client<IPStack, Countdown>(ipstack);

    MQTT::Client<IPStack, Countdown>::connectionLostInfo info = {&client, &ipstack};
    int rc = connect(&info);
    rc = client.subscribe(topic, MQTT::QOS2, messageArrived);   
    if (rc != 0)
        printf("rc from MQTT subscribe is %d\n", rc);

    MQTT::Message message;

    // QoS 0
    char buf[100];
    sprintf(buf, "Hello World!  QoS 0 message from app version %f", version);
    message.qos = MQTT::QOS0;
    message.retained = false;
    message.dup = false;
    message.payload = (void*)buf;
    message.payloadlen = strlen(buf)+1;
    rc = client.publish(topic, &message);
    while (arrivedcount == 0)
    // QoS 1
	printf("Now QoS 1\n");
    sprintf(buf, "Hello World!  QoS 1 message from app version %f", version);
    message.qos = MQTT::QOS1;
    message.payloadlen = strlen(buf)+1;
    rc = client.publish(topic, &message);
    while (arrivedcount == 1)
    // QoS 2
    sprintf(buf, "Hello World!  QoS 2 message from app version %f", version);
    message.qos = MQTT::QOS2;
    message.payloadlen = strlen(buf)+1;
    rc = client.publish(topic, &message);
    while (arrivedcount == 2)
    rc = client.unsubscribe(topic);
    if (rc != 0)
        printf("rc from unsubscribe was %d\n", rc);
    rc = client.disconnect();
    if (rc != 0)
        printf("rc from disconnect was %d\n", rc);
    printf("Finishing with %d messages received\n", arrivedcount);
    return 0;