MQTT(mosquitto) Visual studio - 2 (Publisher)

간단하게 Publish 할 수 있는 Client를 제작해 봅니다.

<Header>

#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
#include <mosquitto.h>

#define sleep(x) Sleep((x)*1000)
#define strdup _strdup

#define DEFAULT_MQTT_HOST "127.0.0.1"
#define DEFAULT_MQTT_PORT 1883
#define DEFAULT_MQTT_KEEPALIVE 60
#define DEFAULT_MQTT_TOPIC "EXAMPLE_TOPIC"

#define BUF_LENGTH 65536

 

<Callback Function>

void connect_callback(struct mosquitto *mosq, void *obj, int result) {
	printf("connect callback, rc=%d\n", result);
}

void message_callback(struct mosquitto *mosq, void *obj, const struct mosquitto_message *msg) {
	printf("message '%.*s' for topic '%s'\n", msg->payloadlen, (char *)msg->payload, msg->topic);
}

 

<main>

int main(int argc, char **argv)
{
	int rc;
	char *mqtt_host = strdup(DEFAULT_MQTT_HOST);
	char *mqtt_topic = strdup(DEFAULT_MQTT_TOPIC);
	int mqtt_port = DEFAULT_MQTT_PORT;
	int mqtt_keepalive = DEFAULT_MQTT_KEEPALIVE;

	int mdelay = 0;
	bool clean_session = true;
	
	struct mosquitto *mosq = NULL;

	mosquitto_lib_init();
	mosq = mosquitto_new(NULL, clean_session, NULL);
	if (!mosq) {
		fprintf(stderr, "Could not create new mosquitto struct\n");
		exit(1);
	}

	if (mosquitto_connect(mosq, mqtt_host, mqtt_port, mqtt_keepalive)) {
		fprintf(stderr, "Unable to connect mosquitto.\n");
		exit(1);
	}

	char buf[BUF_LENGTH];

	do {
		rc = mosquitto_loop(mosq, -1, 1);

		scanf_s("%s", buf, BUF_LENGTH);
		if (!strcmp(buf, "exit")) break;

		rc = mosquitto_publish(mosq, NULL, mqtt_topic,  strlen(buf), buf, 0, 0);
		if (rc != MOSQ_ERR_SUCCESS) {
			fprintf(stderr, "Error publishing: %s\n", mosquitto_strerror(rc));
		}
		
	} while (rc == MOSQ_ERR_SUCCESS);

	mosquitto_destroy(mosq);
	mosquitto_lib_cleanup();
	free(mqtt_host);
	free(mqtt_topic);

	return 0;
}