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我也是复制的，没有测试。应该能正常工作中。
发布端
/********************************************************************************** Copyright: (C) 2022 Ye Xingwei<2929273315@qq.com>* All rights reserved.** Filename: subscribe.c* Description: This file MQTT_pub* * Version: 1.0.0(2022年01月04日)* Author: Ye Xingwei <2929273315@qq.com>* ChangeLog: 1, Release initial version on "2022年01月04日 15时08分27秒"* ********************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <mosquitto.h>
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#include <signal.h>
#include <ctype.h>#include "cJSON.h"#define HOST "localhost"
#define PORT 1883
#define KEEP_ALIVE 60
#define MSG_MAX_SIZE 512static int g_stop = 0;void mqtt_connect_callback(struct mosquitto *mosq, void *obj, int rc);
void mqtt_disconnect_callback(struct mosquitto *mosq, void *obj, int rc);
int get_time(char *datetime, int bytes);
int get_temperature(float *temp);
int get_ipaddr(char *interface,char *ipaddr,int ipaddr_size);
void sig_handle(int signum);int main (int argc, char **argv)
{int rv;struct mosquitto *mosq = NULL;/*安装信号*/signal(SIGUSR1,sig_handle);/* MQTT 初始化 */rv = mosquitto_lib_init();if(rv != MOSQ_ERR_SUCCESS){printf("mosquitto lib int failure:%s\n", strerror(errno));goto cleanup;}/* 创建新的客户端 */mosq = mosquitto_new(NULL,true,NULL);if(!mosq){printf("create client failure:%s\n",strerror(errno));goto cleanup;}/* 回调函数 */mosquitto_connect_callback_set(mosq, mqtt_connect_callback);while(!g_stop){/* 连接MQTT服务器,ip,端口,时间 */ if(mosquitto_connect(mosq,HOST,PORT,KEEP_ALIVE) != MOSQ_ERR_SUCCESS){printf("mosquitto_connect() failed: %s\n",strerror(errno));goto cleanup;}printf("connect successfully\n");/* 无阻塞 断线连接 */mosquitto_loop_forever(mosq,-1,1);sleep(10);}cleanup: mosquitto_destroy(mosq);mosquitto_lib_cleanup();return 0;
} /*确认连接回函数*/
void mqtt_connect_callback(struct mosquitto *mosq, void *obj, int rc)
{char ipaddr[16];char *interface="eth0";char datetime[64];cJSON *root;cJSON *item;char *msg;struct mqtt_user_data *mqtt;printf("Connection successful cJSON call packaging\n");float temper = 0.000000;if(get_temperature(&temper) < 0){printf("get_temperature failed.\n");return;}if(get_time(datetime,sizeof(datetime))<0){printf("get_time failure\n");return ;}memset(ipaddr,0,sizeof(ipaddr));if(get_ipaddr(interface,ipaddr,sizeof(ipaddr))<0){printf("ERROR:get ip address failure\n");return ;}root = cJSON_CreateObject();item = cJSON_CreateObject();/* cJSON打包 */cJSON_AddItemToObject(root,"id",cJSON_CreateString(ipaddr));cJSON_AddItemToObject(root,"time",cJSON_CreateString(datetime));cJSON_AddItemToObject(root,"Temperature",cJSON_CreateNumber(temper));msg = cJSON_Print(root);//printf("%s\n",msg);if(!rc){if(mosquitto_publish(mosq,NULL,"temp",strlen(msg),msg,0,NULL) != MOSQ_ERR_SUCCESS){printf("mosquitto_publish failed: %s\n",strerror(errno));return;}}mosquitto_disconnect(mosq);
}/* 获取时间 */
int get_time(char *datetime, int bytes)
{time_t now;struct tm *t;time(&now);t = localtime(&now);snprintf(datetime, bytes, "%04d-%02d-%02d %02d:%02d:%02d", t->tm_year + 1900, t->tm_mon + 1, t->tm_mday, (t->tm_hour)+8, t->tm_min, t->tm_sec);return 0;
}
/* 安装信号 */
void sig_handle(int signum)
{if(SIGUSR1 == signum){g_stop = 1;}
}/* 获取温度 */
int get_temperature(float *temp)
{int fd = -1;char buf[128];char *ptr=NULL;DIR *dirp = NULL;struct dirent *direntp = NULL;char w1_path[64]="/sys/bus/w1/devices/";char chip_sn[32];int found = 0;dirp=opendir(w1_path);if(!dirp){printf("open foldir %s failure:%s\n",w1_path,strerror(errno));return -1;}while(NULL!=(direntp=readdir(dirp))){if(strstr(direntp->d_name,"28-")){strncpy(chip_sn, direntp->d_name,sizeof(chip_sn));found = -1;}}closedir(dirp);if(!found){printf("can not find ds18b20 chipset\n");return -2;}strncat(w1_path,chip_sn,sizeof(w1_path)-strlen(w1_path));strncat(w1_path,"/w1_slave",sizeof(w1_path)-strlen(w1_path));if((fd = open(w1_path,O_RDONLY))<0){printf("File opened successfully:%s\n",strerror(errno));return -3;}memset(buf, 0, sizeof(buf));if(read(fd, buf, sizeof(buf))<0){printf("read data from fd=%d failure:%s\n",fd,strerror(errno));return -4;}ptr = strstr(buf,"t=");if(!ptr){printf("t=string\n");return -5;}ptr+= 2;*temp = atof(ptr)/1000;close(fd);return 0;}/* 获取IP地址 */
int get_ipaddr(char *interface,char *ipaddr,int ipaddr_size)
{char buf[1024];char *ptr;char *ip_start;char *ip_end;FILE *fp;int len;int rv;if(!interface || !ipaddr || ipaddr_size <16){printf("Invalid input argument\n");return -2;}memset(buf, 0 , sizeof(buf));snprintf(buf,sizeof(buf),"ifconfig %s",interface);fp = popen(buf,"r");if(NULL==fp){printf("popen() to extern command\"%s\"failure:%s\n",buf,strerror(errno));return -2;}rv = -3;while(fgets(buf,sizeof(buf),fp)){if(strstr(buf,"netmask")){ptr = strstr(buf,"inet");if(!ptr){break;}ptr +=strlen("inet");while(isblank(*ptr))ptr++;ip_start = ptr;while(!isblank(*ptr))ptr++;ip_end = ptr;memset(ipaddr,0,sizeof(ipaddr));len = ip_end-ip_start;len = len>ipaddr_size ? ipaddr_size:len;memcpy(ipaddr,ip_start,len);rv = 0;break;}}pclose(fp);return rv;
}订阅端
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <mosquitto.h>#include "cJSON.h"#define HOST "localhost"
#define PORT 1883
#define KEEP_ALIVE 60
#define MSG_MAX_SIZE 512static int running = 1;/* 确认连接回调函数 */
void mqtt_connect_callback(struct mosquitto *mosq, void *obj, int rc)
{printf("Confirm the connection to the client\n");if(rc){printf("on_connect error!\n");exit(1);}else{if(mosquitto_subscribe(mosq, NULL, "temp", 2)){printf("Set the topic error!\n");exit(1);}}
}/*获取到订阅的内容*/
void mqtt_message_callback(struct mosquitto *mosq, void *obj, const struct mosquitto_message *msg)
{printf("Obtaining content successfully\n");printf("\n");printf("Succeeded in obtaining the time and temperature:%s\n", (char *)msg->payload);
}int main (int argc, char **argv)
{int ret;struct mosquitto *mosq;/* MQTT 初始化 */ret = mosquitto_lib_init();if(ret){printf("Init lib error!\n");goto cleanup;return -1;}/* 创建新的客户端 */mosq = mosquitto_new(NULL,true, NULL);if(mosq == NULL){printf("Create a new client failure\n");goto cleanup;return -1;}/* 回调函数 */mosquitto_connect_callback_set(mosq, mqtt_connect_callback);mosquitto_message_callback_set(mosq, mqtt_message_callback);/* 连接代理 */ret = mosquitto_connect(mosq, HOST, PORT, KEEP_ALIVE);if(ret){printf("Connect server error!\n");goto cleanup;return -1;}printf("connection client is OK\n");while(running){mosquitto_loop(mosq, -1, 1);}/* 释放 清空 */
cleanup:mosquitto_destroy(mosq);mosquitto_lib_cleanup();return 0;
}
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