Simple MQTT publish and subscribe using Paho embedded C/C++ Client

build.sh

cp ../../src/MQTTClient.c .
sed -e 's/""/"MQTTLinux.h"/g' ../../src/MQTTClient.h > MQTTClient.h

gcc sub.c -I ../../src -I ../../src/linux -I ../../../MQTTPacket/src MQTTClient.c ../../src/linux/MQTTLinux.c ../../../MQTTPacket/src/MQTTFormat.c  ../../../MQTTPacket/src/MQTTPacket.c ../../../MQTTPacket/src/MQTTDeserializePublish.c ../../../MQTTPacket/src/MQTTConnectClient.c ../../../MQTTPacket/src/MQTTSubscribeClient.c ../../../MQTTPacket/src/MQTTSerializePublish.c -o sub ../../../MQTTPacket/src/MQTTConnectServer.c ../../../MQTTPacket/src/MQTTSubscribeServer.c ../../../MQTTPacket/src/MQTTUnsubscribeServer.c ../../../MQTTPacket/src/MQTTUnsubscribeClient.c

gcc pub.c -I ../../src -I ../../src/linux -I ../../../MQTTPacket/src MQTTClient.c ../../src/linux/MQTTLinux.c ../../../MQTTPacket/src/MQTTFormat.c  ../../../MQTTPacket/src/MQTTPacket.c ../../../MQTTPacket/src/MQTTDeserializePublish.c ../../../MQTTPacket/src/MQTTConnectClient.c ../../../MQTTPacket/src/MQTTSubscribeClient.c ../../../MQTTPacket/src/MQTTSerializePublish.c -o pub ../../../MQTTPacket/src/MQTTConnectServer.c ../../../MQTTPacket/src/MQTTSubscribeServer.c ../../../MQTTPacket/src/MQTTUnsubscribeServer.c ../../../MQTTPacket/src/MQTTUnsubscribeClient.c

build_cpp.sh

g++ pub.cpp -I ../../src/ -I ../../src/linux -I ../../../MQTTPacket/src ../../../MQTTPacket/src/MQTTPacket.c ../../../MQTTPacket/src/MQTTDeserializePublish.c ../../../MQTTPacket/src/MQTTConnectClient.c ../../../MQTTPacket/src/MQTTSubscribeClient.c ../../../MQTTPacket/src/MQTTSerializePublish.c ../../../MQTTPacket/src/MQTTUnsubscribeClient.c -o pub

g++ sub.cpp -I ../../src/ -I ../../src/linux -I ../../../MQTTPacket/src ../../../MQTTPacket/src/MQTTPacket.c ../../../MQTTPacket/src/MQTTDeserializePublish.c ../../../MQTTPacket/src/MQTTConnectClient.c ../../../MQTTPacket/src/MQTTSubscribeClient.c ../../../MQTTPacket/src/MQTTSerializePublish.c ../../../MQTTPacket/src/MQTTUnsubscribeClient.c -o sub

pub.c

#include <stdio.h>
#include "MQTTClient.h"
#include <stdio.h>
#include <signal.h>
#include <memory.h>
#include <sys/time.h>

volatile int toStop = 0;

void usage(char** argv)
{
    printf("Usage: %s topic channel_token\n", argv[0]);
    exit(-1);
}

void cfinish(int sig)
{
    signal(SIGINT, NULL);
    toStop = 1;
}

int main(int argc, char** argv)
{
    int rc = 0;
    unsigned char buf[100];
    unsigned char readbuf[100];

    if (argc < 3)
        usage(argv);

    char* host = "mqtt.beebotte.com";
    int port = 1883;
    char* topic = argv[1];
    char* clientid = "myid";
    char* username = argv[2];

    Network n;
    Client c;

    signal(SIGINT, cfinish);
    signal(SIGTERM, cfinish);

    NewNetwork(&n);
    ConnectNetwork(&n, host, port);
    MQTTClient(&c, &n, 1000, buf, 100, readbuf, 100);

    MQTTPacket_connectData data = MQTTPacket_connectData_initializer;
    data.willFlag = 0;
    data.MQTTVersion = 3;
    data.clientID.cstring = clientid;
    data.username.cstring = username;
    //data.password.cstring = opts.password;

    data.keepAliveInterval = 10;
    data.cleansession = 1;
    printf("Connecting to %s %d\n", host, port);

    rc = MQTTConnect(&c, &data);
    printf("Connected %d\n", rc);

    printf("Publishing to %s\n", topic);

    char payload[100];
    sprintf(payload, "Hello World - youppi!");
    MQTTMessage pubmsg;
    pubmsg.payload = payload;
    pubmsg.payloadlen = strlen(payload) + 1;
    pubmsg.qos = QOS0;
    pubmsg.retained = 0;
    rc = MQTTPublish (&c, topic, &pubmsg);

    while (!toStop)
    {
        MQTTYield(&c, 1000);
        rc = MQTTPublish (&c, topic, &pubmsg);
    }

    printf("Stopping\n");

    MQTTDisconnect(&c);
    n.disconnect(&n);

    return 0;
}

pub.cpp

#include "MQTTClient.h"
#include "linux.cpp"

void usage(char** argv)
{
    printf("Usage: %s topic channel_token\n", argv[0]);
    exit(-1);
}

int main(int argc, char* argv[])
{
    IPStack ipstack = IPStack();
    float version = 0.3;

    if (argc < 3)
        usage(argv);

    printf("Version is %f\n", version);

    MQTT::Client<IPStack, Countdown> client = MQTT::Client<IPStack, Countdown>(ipstack);

    const char* hostname = "mqtt.beebotte.com";

    int port = 1883;
    const char* topic = argv[1];
    printf("Connecting to %s:%d\n", hostname, port);
    int rc = ipstack.connect(hostname, port);
    if (rc != 0)
        printf("rc from TCP connect is %d\n", rc);

    printf("MQTT connecting\n");
    MQTTPacket_connectData data = MQTTPacket_connectData_initializer;
    data.MQTTVersion = 3;
    data.clientID.cstring = (char*)"myid";
    data.username.cstring = argv[2];
    rc = client.connect(data);
    if (rc != 0)
        printf("rc from MQTT connect is %d\n", rc);
    printf("MQTT connected\n");


    MQTT::Message message;

    char buf[100];
    sprintf(buf, "Hello World!");
    message.qos = MQTT::QOS0;
    message.retained = false;
    message.dup = false;
    message.payload = (void*)buf;
    message.payloadlen = strlen(buf)+1;

    rc = client.publish(topic, message);
    if (rc != 0)
        printf("Error %d from sending QoS 2 message\n", rc);

    rc = client.disconnect();
    if (rc != 0)
        printf("rc from disconnect was %d\n", rc);

    ipstack.disconnect();

    return 0;
}

sub.c

#include <stdio.h>
#include "MQTTClient.h"
#include <stdio.h>
#include <signal.h>
#include <memory.h>
#include <sys/time.h>

volatile int toStop = 0;

void usage(char** argv)
{
    printf("Usage: %s topic channel_token\n", argv[0]);
    exit(-1);
}

void cfinish(int sig)
{
    signal(SIGINT, NULL);
    toStop = 1;
}

void messageArrived(MessageData* md)
{
    MQTTMessage* message = md->message;

    printf("%.*s\t", md->topicName->lenstring.len, md->topicName->lenstring.data);
    printf("%.*s\n", (int)message->payloadlen, (char*)message->payload);
}


int main(int argc, char** argv)
{
    int rc = 0;
    unsigned char buf[100];
    unsigned char readbuf[100];

    if (argc < 3)
        usage(argv);

    char* host = "mqtt.beebotte.com";
    int port = 1883;
    char* topic = argv[1];
    char* clientid = "myid";
    char* username = argv[2];

    Network n;
    Client c;

    signal(SIGINT, cfinish);
    signal(SIGTERM, cfinish);

    NewNetwork(&n);
    ConnectNetwork(&n, host, port);
    MQTTClient(&c, &n, 1000, buf, 100, readbuf, 100);

    MQTTPacket_connectData data = MQTTPacket_connectData_initializer;
    data.willFlag = 0;
    data.MQTTVersion = 3;
    data.clientID.cstring = clientid;
    data.username.cstring = username;
    //data.password.cstring = opts.password;

    data.keepAliveInterval = 10;
    data.cleansession = 1;
    printf("Connecting to %s %d\n", host, port);

    rc = MQTTConnect(&c, &data);
    printf("Connected %d\n", rc);

    printf("Subscribing to %s\n", topic);
    rc = MQTTSubscribe(&c, topic, QOS1, messageArrived);
    printf("Subscribed %d\n", rc);

    while (!toStop)
    {
        MQTTYield(&c, 1000);
    }

    printf("Stopping\n");

    MQTTDisconnect(&c);
    n.disconnect(&n);

    return 0;
}

sub.cpp

#include "MQTTClient.h"
#include "linux.cpp"

int arrivedcount = 0;

void usage(char** argv)
{
    printf("Usage: %s topic channel_token\n", argv[0]);
    exit(-1);
}

void messageArrived(MQTT::MessageData& md)
{
    MQTT::Message &message = md.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 main(int argc, char* argv[])
{
    IPStack ipstack = IPStack();
    float version = 0.3;

    if (argc < 3)
        usage(argv);

    printf("Version is %f\n", version);

    MQTT::Client<IPStack, Countdown> client = MQTT::Client<IPStack, Countdown>(ipstack);

    const char* hostname = "mqtt.beebotte.com";

    int port = 1883;
    printf("Connecting to %s:%d\n", hostname, port);
    int rc = ipstack.connect(hostname, port);
    if (rc != 0)
        printf("rc from TCP connect is %d\n", rc);

    printf("MQTT connecting\n");

    const char* topic = argv[1];
    MQTTPacket_connectData data = MQTTPacket_connectData_initializer;
    data.username.cstring = (char*)argv[2];
    data.MQTTVersion = 3;
    data.clientID.cstring = (char*)"myid";
    rc = client.connect(data);
    if (rc != 0)
        printf("rc from MQTT connect is %d\n", rc);
    printf("MQTT connected\n");

    rc = client.subscribe(topic, MQTT::QOS1, messageArrived);
    if (rc != 0)
        printf("rc from MQTT subscribe is %d\n", rc);

    while (1) {
        client.yield(5000);
    }

    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);

    ipstack.disconnect();

    printf("Finishing with %d messages received\n", arrivedcount);

    return 0;
}