C 对mosquitto_lib_init的未定义引用

问题

• 对MOSQUITO_lib_init和其他一些C函数的未定义引用，生成以下错误：
  gcc-o“Protheus”。/src/Brain/Brain.o./src/Brain/Network.o
  ./src/Brain/Network.o:在函数

  mqtt_init_server'中：
  Network.c:（.text+0x1b8）：未定义对

  mosquitto_new' Network.c:（.text+0x1cf）：对

  mosquitto\u connect'的未定义引用
  Network.c:（.text+0x1d8）：对

  mosquitto_lib_init'的未定义引用 makefile:30:目标“Protheus”的配方失败 Network.c:（.text+0x1f2）：对

  mosquitto\u subscribe'的未定义引用
  Network.c:（.text+0x203）：对

  mosquito\u message\u callback\u set'的未定义引用 Network.c:（.text+0x215）：对

  mosquitto\u loop\u forever'的未定义引用
  Network.c:（.text+0x21d）：对

  mosquitto\u destroy'的未定义引用 Network.c:（.text+0x222）：对“mosquitto_lib_cleanup”的未定义引用 collect2:错误：ld返回了1个退出状态 make:**[Protheus]错误1

• 我尝试使用mosquito.h运行代码，但无法编译该源代码

• 当我试着运行代码时，我的makefile就坏了

[制作文件]

    -include ../makefile.init

    RM := rm -rf

    # All of the sources participating in the build are defined here
    -include sources.mk
    -include src/Brain/subdir.mk
    -include subdir.mk
    -include objects.mk

    ifneq ($(MAKECMDGOALS),clean)
    ifneq ($(strip $(C_DEPS)),)
    -include $(C_DEPS)
    endif
    endif

    -include ../makefile.defs

    # Add inputs and outputs from these tool invocations to the build variables 

    # All Target
    all: Protheus

    # Tool invocations
    Protheus: $(OBJS) $(USER_OBJS)
        @echo 'Building target: $@'
        @echo 'Invoking: GCC C Linker'
        gcc  -o "Protheus" $(OBJS) $(USER_OBJS) $(LIBS)
        @echo 'Finished building target: $@'
        @echo ' '

    # Other Targets
    clean:
        -$(RM) $(EXECUTABLES)$(OBJS)$(C_DEPS) Protheus
        -@echo ' '

    .PHONY: all clean dependents
    .SECONDARY:

-include ../makefile.targets

==================================================================

• 我的代码是：

  int ip_address(){
      int fd;
      struct ifreq ifr;
      char iface[] = "eth0";
      fd = socket(AF_INET, SOCK_DGRAM, 0);
  
  
      ifr.ifr_addr.sa_family = AF_INET;
  
  
      strncpy(ifr.ifr_name, iface, IFNAMSIZ - 1);
      ioctl(fd, SIOCGIFADDR, &ifr);
      close(fd);
  
  
      IFACE = iface;
      IP_ADDRESS = inet_ntoa(((struct sockaddr_in *) &ifr.ifr_addr)->sin_addr);
      if (IP_ADDRESS != NULL && strlen(IP_ADDRESS) > 7) {
  
      return 1;
      }
  
  return 0;    }
  

  int check_连接（）{
  void my_message_回调（struct mosquitto*mosq、void*obj、const struct mosquitto_message*message）{
  printf（“获取消息：%s\n”，（char*）消息->负载）

}

---

有人能帮我吗？

未定义的引用是一个链接错误。您没有链接到包含该代码的库。
   if (ip_address()){


        return 0;
    }

return 1;}

int mqtt_init_server(){
    MOSQUITTO *mosq = NULL;
    mosq    = mosquitto_new(NULL,0,NULL);
    int ret = mosquitto_connect(mosq, MQTT_HOSTNAME,MQTT_PORT,0);

    if (0 == ret || !mosquitto_lib_init() || !mosq)
        {
            fprintf (stderr, "Can't initialize Mosquitto library\n");
            return 0;
        }

    ret = mosquitto_subscribe(mosq,NULL,MQTT_TOPIC,0);
    if(ret)
        {
            fprintf (stderr, "Can't publish to Mosquitto server\n");
            return 0;
        }

    mosquitto_message_callback_set (mosq, my_message_callback);
    mosquitto_loop_forever(mosq,-1,1);
    mosquitto_destroy (mosq);
    mosquitto_lib_cleanup();

    return 1;
    printf("CONECTED");
}