基于mosquitto库实现MQTT订阅与发布

一、下载安装mosquitto

• （1）下载地址：https://mosquitto.org/download/
  Linux命令行输入

wget https://mosquitto.org/files/source/mosquitto-1.6.12.tar.gz

• （2）解压

tar -zxvf mosquitto-1.6.12.tar.gz

• （3）编译安装

make
sudo make install

• （4）解决依赖
  在这里可能会遇到编译安装的问题，都是缺少相关依赖，提示错误信息里缺少什么，下载什么即可

sudo apt-get install libssl-dev
sudo apt-get install uuid-dev
sudo apt-get install cmake

二、mosquitto发布与订阅

• 发布端

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include "mosquitto.h"

#define HOST "localhost"
#define PORT  1883
#define KEEP_ALIVE 60
#define MSG_MAX_SIZE  512

static int running = 1;

void my_connect_callback(struct mosquitto *mosq, void *obj, int rc)
{
   
        printf("Call the function: my_connect_callback\n");

}

void my_disconnect_callback(struct mosquitto *mosq, void *obj, int rc)
{
   
        printf("Call the function: my_disconnect_callback\n");
        running = 0;
}

void my_publish_callback(struct mosquitto *mosq, void *obj, int mid)
{
   
        printf("Call the function: my_publish_callback\n");

}


int main()
{
   
        int ret;
        struct mosquitto *mosq;
		char buff[MSG_MAX_SIZE];
		
		/*初始化libmosquitto库*/
        ret = mosquitto_lib_init()