LINUX--ubuntu移植MQTT并测试成功

1. #include <stdio.h> #include <stdlib.h> #include <mosquitto.h> #include <string.h>

#define HOST “localhost” #define PORT 1883 #define KEEP_ALIVE 60

bool session = true;

void my_message_callback(struct mosquitto *mosq, void *userdata, const struct mosquitto_message *message) { if(message->payloadlen){ printf("%s %s", message->topic, message->payload); }else{ printf("%s (null) ", message->topic); } fflush(stdout); }

void my_connect_callback(struct mosquitto *mosq, void userdata, int result) { int i; if(!result){ / Subscribe to broker information topics on successful connect. */ mosquitto_subscribe(mosq, NULL, “Gai爷:”, 2); }else{ fprintf(stderr, “Connect failed ”); } }

void my_subscribe_callback(struct mosquitto *mosq, void *userdata, int mid, int qos_count, const int *granted_qos) { int i; printf(“Subscribed (mid: %d): %d”, mid, granted_qos[0]); for(i=1; i<qos_count; i++){ printf(", %d", granted_qos[i]); } printf(" "); }

void my_log_callback(struct mosquitto *mosq, void *userdata, int level, const char str) { / Pring all log messages regardless of level. */ printf("%s ", str); }

int main() { struct mosquitto *mosq = NULL; //libmosquitto 库初始化 mosquitto_lib_init(); //创建mosquitto客户端 mosq = mosquitto_new(NULL,session,NULL); if(!mosq){ printf(“create client failed… ”); mosquitto_lib_cleanup(); return 1; } //设置回调函数，需要时可使用 mosquitto_log_callback_set(mosq, my_log_callback); mosquitto_connect_callback_set(mosq, my_connect_callback); mosquitto_message_callback_set(mosq, my_message_callback); mosquitto_subscribe_callback_set(mosq, my_subscribe_callback); //客户端连接服务器 if(mosquitto_connect(mosq, HOST, PORT, KEEP_ALIVE)){ fprintf(stderr, “Unable to connect. ”); return 1; } //循环处理网络消息 mosquitto_loop_forever(mosq, -1, 1);

mosquitto_destroy(mosq);
mosquitto_lib_cleanup();

return 0;

}

客户端（发布消息）

1. #include <stdio.h> #include <stdlib.h> #include <mosquitto.h> #include <string.h>

#define HOST “localhost” #define PORT 1883 #define KEEP_ALIVE 60 #define MSG_MAX_SIZE 512

bool session = true;

int main() { char buff[MSG_MAX_SIZE]; struct mosquitto *mosq = NULL; //libmosquitto 库初始化 mosquitto_lib_init(); //创建mosquitto客户端 mosq = mosquitto_new(NULL,session,NULL); if(!mosq){ printf(“create client failed… ”); mosquitto_lib_cleanup(); return 1; } //连接服务器 if(mosquitto_connect(mosq, HOST, PORT, KEEP_ALIVE)){ fprintf(stderr, “Unable to connect. ”); return 1; } //开启一个线程，在线程里不停的调用 mosquitto_loop() 来处理网络信息 int loop = mosquitto_loop_start(mosq); if(loop != MOSQ_ERR_SUCCESS) { printf(“mosquitto loop error ”); return 1; } while(fgets(buff, MSG_MAX_SIZE, stdin) != NULL) { /发布消息/ mosquitto_publish(mosq,NULL,“Gai爷:”,strlen(buff)+1,buff,0,0); memset(buff,0,sizeof(buff)); } mosquitto_destroy(mosq); mosquitto_lib_cleanup(); return 0; }

注意 在编译程序时需加上-lmosquitto链接。如：

$ gcc -o mosquitto_client_sub mosquitto_client_sub.c -lmosquitto 5,客户端使用 （1）开启mosquitto服务 $ mosquitto -v （2）启动订阅消息客户端及发布消息客户端 $ ./mosquitto_client_sub $ ./mosquitto_client_pub