Question

我正在尝试为mosquitto pub命令设置一个函数。此命令保存在主.c文件的单独.c文件中。一切都编译得很好但是当我从外部.c文件中调用函数（在外部.c文件中调用）时没有任何反应。相反，如果我在没有外部.c文件的情况下在其自己的编译程序中调用该函数，则该函数将按预期运行。意识到我做错了什么，我尝试通过一个简单的printf函数做一些简单的事情并在外部.c文件中调用它，它编译得很好但仍然不打印我的数据。我究竟做错了什么？我也在.h中定义了函数。

void mosquittoto(void)
{
  struct mosquitto *mosq = NULL;

  // Initialize the Mosquitto library
  mosquitto_lib_init();

  // Create a new Mosquitto runtime instance with a random client ID,
  //  and no application-specific callback data.  
  mosq = mosquitto_new (NULL, true, NULL);
  if (!mosq)
    {
    fprintf (stderr, "Can't initialize Mosquitto library\n");
    exit (-1);
    }

  mosquitto_username_pw_set (mosq, MQTT_USERNAME, MQTT_PASSWORD);

  // Establish a connection to the MQTT server. Do not use a keep-alive ping
  int ret = mosquitto_connect (mosq, MQTT_HOSTNAME, MQTT_PORT, 0);
  if (ret)
    {
    fprintf (stderr, "Can't connect to Mosquitto server\n");
    exit (-1);
    }

  int i;
  char text[20];
  for (i = 0; i < 10; i++)
    {
    //sprintf (text, "Hello, World %d", i);
    // Publish the message to the topic
    ret = mosquitto_publish (mosq, NULL, MQTT_TOPIC,
      strlen (epc4pub), epc4pub, 0, false);
    if (ret)
      {
      fprintf (stderr, "Can't publish to Mosquitto server\n");
      exit (-1);
      }
    }

  // We need a short delay here, to prevent the Mosquitto library being
  //  torn down by the operating system before all the network operations
  //  are finished.
  sleep (1);

  // Tidy up
  mosquitto_disconnect (mosq);
  mosquitto_destroy (mosq);
  mosquitto_lib_cleanup();
}

我在.h文件中定义的函数为：

void mosquittoto(void);

谢谢大家的帮助！

从外部.c文件调用的函数不执行任何操作

0 个答案: