Function wait_bc

backend/socket.c:457–494

 */

static ssize_t				/* O - # bytes read or -1 on error */
wait_bc(int device_fd,			/* I - Socket */
        int secs)			/* I - Seconds to wait */
{
  struct timeval timeout;		/* Timeout for select() */
  fd_set	input;			/* Input set for select() */
  ssize_t	bytes;			/* Number of back-channel bytes read */
  char		buffer[1024];		/* Back-channel buffer */


 /*
  * Wait up to "secs" seconds for backchannel data...
  */

  timeout.tv_sec  = secs;
  timeout.tv_usec = 0;

  FD_ZERO(&input);
  FD_SET(device_fd, &input);

  if (select(device_fd + 1, &input, NULL, NULL, &timeout) > 0)
  {
   /*
    * Grab the data coming back and spit it out to stderr...
    */

    if ((bytes = read(device_fd, buffer, sizeof(buffer))) > 0)
    {
      fprintf(stderr, "DEBUG: Received %d bytes of back-channel data\n",
	      (int)bytes);
      cupsBackChannelWrite(buffer, (size_t)bytes, 1.0);
    }

    return (bytes);
  }
  else
    return (-1);
}