#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/select.h>
#include <errno.h>
#include <sys/stat.h>

#define FIFO_PATH "/tmp/myfifo"

int
main ()
{
  int fd, tmpfd, nsel;
  fd_set readfds;
  struct timeval wait_tm = { 0l, 200000l }; /* 200 millisecs */

  if (unlink (FIFO_PATH) < 0  && errno != ENOENT)
    {
      perror ("unlink");
      exit (1);
    }

  if (mkfifo (FIFO_PATH, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH
	      | S_IWOTH) < 0)
    {
      perror ("mkfifo");
      exit (1);
    }

  printf ("Opening a FIFO for reading with O_NONBLOCK\n");
  if ((fd = open (FIFO_PATH, O_RDONLY | O_NONBLOCK)) < 0)
    {
      perror ("open");
      exit (1);
    }

  printf ("Testing for read ready...\n");
  FD_ZERO (&readfds);
  FD_SET (fd, &readfds);
  nsel = select (fd + 1, &readfds, NULL, NULL, &wait_tm);
  printf ("  select returned %d\n", nsel);

  printf ("Opening and closing FIFO for writing...\n");
  if ((tmpfd = open (FIFO_PATH, O_WRONLY)) < 0)
    {
      perror ("open");
      exit (1);
    }
  if (close (tmpfd) < 0)
    {
      perror ("close");
      exit (1);
    }

  FD_ZERO (&readfds);
  FD_SET (fd, &readfds);
  nsel = select (fd + 1, &readfds, NULL, NULL, &wait_tm);
  printf ("  now select returned %d\n", nsel);
}