static int
read_printer_data()
{
	struct pollfd	fd[1];

	/* Open device file for printer gadget. */
	fd[0].fd = open(PRINTER_FILE, O_RDWR);
	if (fd[0].fd < 0) {
		printf("Error %d opening %s\n", fd[0].fd, PRINTER_FILE);
		close(fd[0].fd);
		return(-1);
	}

	fd[0].events = POLLIN | POLLRDNORM;

	while (1) {
		static char buf[BUF_SIZE];
		int bytes_read;
		int retval;

		/* Wait for up to 1 second for data. */
		retval = poll(fd, 1, 1000);

		if (retval && (fd[0].revents & POLLRDNORM)) {

			/* Read data from printer gadget driver. */
			bytes_read = read(fd[0].fd, buf, BUF_SIZE);

			if (bytes_read < 0) {
				printf("Error %d reading from %s\n",
						fd[0].fd, PRINTER_FILE);
				close(fd[0].fd);
				return(-1);
			} else if (bytes_read > 0) {
				/* Write data to standard OUTPUT (stdout). */
				fwrite(buf, 1, bytes_read, stdout);
				fflush(stdout);
			}

		}

	}

	/* Close the device file. */
	close(fd[0].fd);

	return 0;
}