p_civil_aviation_mqtt/c/main.c

//
// Created by zwsd
//
#include "MQTTClient.h"
#include "stdlib.h"
#include "string.h"
#include "unistd.h"

#define ADDRESS  "mqtt://iot-06z00dtdbnukzsk.mqtt.iothub.aliyuncs.com:1883"
#define USERNAME "mh_2&iekhmHv4wIC"
#define PASSWORD "8491b7d3391d51f40120bb9d81a4b713c624ce7beb216b9d37076508ac6e7446"
#define CLIENTID "iekhmHv4wIC.mh_2|securemode=2,signmethod=hmacsha256,timestamp=1680575050297|"
#define QOS      0
#define TOPIC    "/sys/iekhmHv4wIC/mh_2/thing/event/property/post"
#define TIMEOUT  10000L

void publish(MQTTClient client, char *topic, char *payload) {
  MQTTClient_message message = MQTTClient_message_initializer;
  message.payload            = payload;
  message.payloadlen         = strlen(payload);
  message.qos                = QOS;
  message.retained           = 0;
  MQTTClient_deliveryToken token;
  MQTTClient_publishMessage(client, topic, &message, &token);
  MQTTClient_waitForCompletion(client, token, TIMEOUT);
  printf("Send `%s` to topic `%s` \n", payload, TOPIC);
}

int on_message(void *context, char *topicName, int topicLen, MQTTClient_message *message) {
  char *payload = message->payload;
  printf("Received `%s` from `%s` topic \n", payload, topicName);
  MQTTClient_freeMessage(&message);
  MQTTClient_free(topicName);
  return 1;
}

int main(int argc, char *argv[]) {
  int        rc;
  MQTTClient client;

  MQTTClient_create(&client, ADDRESS, CLIENTID, 0, NULL);
  MQTTClient_connectOptions conn_opts = MQTTClient_connectOptions_initializer;
  conn_opts.username                  = USERNAME;
  conn_opts.password                  = PASSWORD;
  MQTTClient_setCallbacks(client, NULL, NULL, on_message, NULL);
  if ((rc = MQTTClient_connect(client, &conn_opts)) != MQTTCLIENT_SUCCESS) {
    printf("Failed to connect, return code %d\n", rc);
    exit(-1);
  } else {
    printf("Connected to MQTT Broker!\n");
  }
  // subscribe topic
  MQTTClient_subscribe(client, TOPIC, QOS);
  char payload[23];
  for (int i = 0; i < 100; i += 1) {
    // publish message to broker
    snprintf(payload, 23, "{\"RunningState\": \"%d\"}", i);
    publish(client, TOPIC, payload);
    sleep(1);
  }
  MQTTClient_disconnect(client, TIMEOUT);
  MQTTClient_destroy(&client);
  return rc;
}