百度IOT Hub （十） Paho C Client Publish Operation without SSL

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

#define ADDRESS     "tcp://sdmn79a.mqtt.iot.gz.baidubce.com:1883"
#define CLIENTID    "MyMonitor_Pub"
#define TOPIC       "$baidu/iot/general/abc"
#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_publishMessage
    MQTTClient_deliveryToken token; // ==> MQTTClient_publishMessage
    int rc;

    // 1. Create MQTT Client
    MQTTClient_create(&client, ADDRESS, CLIENTID,
        MQTTCLIENT_PERSISTENCE_NONE, NULL);

    conn_opts.keepAliveInterval = 20;
    conn_opts.cleansession = 1;
    conn_opts.username = "sdmn79a/MyMonitor_Pub";
    conn_opts.password = "xxxxxxx";
    conn_opts.MQTTVersion = MQTTVERSION_3_1_1;

    // 2. Establish MQTT Connection
    if ((rc = MQTTClient_connect(client, &conn_opts)) != MQTTCLIENT_SUCCESS)
    {
        printf("Failed to connect, return code %d\n", rc);
        exit(EXIT_FAILURE);
    }

    // 3. Send Topic with Payload
    pubmsg.payload = PAYLOAD;
    pubmsg.payloadlen = (int)strlen(PAYLOAD);
    pubmsg.qos = QOS;
    pubmsg.retained = 0;

    MQTTClient_publishMessage(client, TOPIC, &pubmsg, &token);
    // MQTTClient_publish(c, test_topic, pubmsg.payloadlen, pubmsg.payload, pubmsg.qos, pubmsg.retained, &token);

    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);

    // 4. Wait For Completion
    rc = MQTTClient_waitForCompletion(client, token, TIMEOUT);
    printf("Message with delivery token %d delivered\n", token);

    MQTTClient_disconnect(client, 10000);
    MQTTClient_destroy(&client);

    return rc;
}