/* This program will take as argument a directory name and monitor it,
   printing event notifications to the console.
*/
int main (int argc, char **argv)
{
   /* This is the file descriptor for the inotify device */
   int inotify_fd;

   /* First we open the inotify dev entry */
   inotify_fd = open_inotify_dev();
   if (inotify_fd < 0)
   {
      return 0;
   }


   /* We will need a place to enqueue inotify events,
      this is needed because if you do not read events
      fast enough, you will miss them.
   */
   queue_t q;
   q = queue_create (128);


   /* Watch the directory passed in as argument
      Read on for why you might want to alter this for
      more efficient inotify use in your app.
   */
   watch_dir (inotify_fd, argv[1], ALL_MASK);
   process_inotify_events (q, inotify_fd);


   /* Finish up by destroying the queue, closing the fd,
      and returning a proper code
   */
   queue_destroy (q);
   close_inotify_dev (inotify_fd);
   return 0;
}

/* This simply opens the inotify node in dev (read only) */
int open_inotify_dev ()
{
   int fd;

   fd = open("/dev/inotify", O_RDONLY);

   if (fd < 0)
   {
      perror ("open(\"/dev/inotify\", O_RDonLY) = ");
   }

   return fd;
}

/* This method does the dirty work of determining what happened,
   then allows us to act appropriately
*/
void handle_event (struct inotify_event *event)
{
   /* If the event was associated with a filename, we will store it here */
   char * cur_event_filename = NULL;


   /* This is the watch descriptor the event occurred on */
   int cur_event_wd = event->wd;

   if (event->len)
   {
      cur_event_filename = event->filename;
   }
   printf("FILENAME=%s\n", cur_event_filename);
        printf("\n");


   /* Perform event dependent handler routines */
   /* The mask is the magic that tells us what file operation occurred */
   switch (event->mask)
   {
      /* File was accessed */
      case IN_ACCESS:
         printf("ACCESS EVENT OCCURRED: File \"%s\" on WD #%i\n",
                 cur_event_filename, cur_event_wd);
      break;


      /* File was modified */
      case IN_MODIFY:
         printf("MODIFY EVENT OCCURRED: File \"%s\" on WD #%i\n",
                 cur_event_filename, cur_event_wd);
      break;


      /* File changed attributes */
      case IN_ATTRIB:
         printf("ATTRIB EVENT OCCURRED: File \"%s\" on WD #%i\n",
                 cur_event_filename, cur_event_wd);
      break;


      /* File was closed */
      case IN_CLOSE:
         printf("CLOSE EVENT OCCURRED: File \"%s\" on WD #%i\n",
                 cur_event_filename, cur_event_wd);
      break;


      /* File was opened */
      case IN_OPEN:
         printf("OPEN EVENT OCCURRED: File \"%s\" on WD #%i\n",
                 cur_event_filename, cur_event_wd);
      break;


      /* File was moved from X */
      case IN_MOVED_FROM:
         printf("MOVE_FROM EVENT OCCURRED: File \"%s\" on WD #%i\n",
                 cur_event_filename, cur_event_wd);
      break;


      /* File was moved to X */
      case IN_MOVED_TO:
         printf("MOVE_TO EVENT OCCURRED: File \"%s\" on WD #%i\n",
                 cur_event_filename, cur_event_wd);
      break;


      /* Subdir was deleted */
      case IN_DELETE_SUBDIR:
         printf("DELETE_SUBDIR EVENT OCCURRED: File \"%s\" on WD #%i\n",
                 cur_event_filename, cur_event_wd);
      break;


      /* File was deleted */
      case IN_DELETE_FILE:
         printf("DELETE_FILE EVENT OCCURRED: File \"%s\" on WD #%i\n",
                 cur_event_filename, cur_event_wd);
      break;


      /* Subdir was created */
      case IN_CREATE_SUBDIR:
         printf("CREATE_SUBDIR EVENT OCCURRED: File \"%s\" on WD #%i\n",
                 cur_event_filename, cur_event_wd);
      break;


      /* File was created */
      case IN_CREATE_FILE:
         printf("CREATE_FILE EVENT OCCURRED: File \"%s\" on WD #%i\n",
                 cur_event_filename, cur_event_wd);
      break;


      /* Watched entry was deleted */
      case IN_DELETE_SELF:
         printf("DELETE_SELF EVENT OCCURRED: File \"%s\" on WD #%i\n",
                 cur_event_filename, cur_event_wd);
      break;


      /* Backing FS was unmounted */
      case IN_UNMOUNT:
         printf("UNMOUNT EVENT OCCURRED: File \"%s\" on WD #%i\n",
                 cur_event_filename, cur_event_wd);
      break;


      /* Too many FS events were received without reading them
         some event notifications were potentially lost.  */
      case IN_Q_OVERFLOW:
         printf("Warning: AN OVERFLOW EVENT OCCURRED: \n");
      break;


      case IN_IGNORED:
         printf("IGNORED EVENT OCCURRED: \n");
      break;


      /* Some unknown message received */
      default:
         printf ("UNKNOWN EVENT OCCURRED for file \"%s\" on WD #%i\n",
              cur_event_filename, cur_event_wd);
      break;
   }
}