+
−/* Test of select() substitute, reading from stdin.
+
−   Copyright (C) 2008, 2009 Free Software Foundation, Inc.
+
−
+
−   This program is free software: you can redistribute it and/or modify
+
−   it under the terms of the GNU General Public License as published by
+
−   the Free Software Foundation; either version 3 of the License, or
+
−   (at your option) any later version.
+
−
+
−   This program is distributed in the hope that it will be useful,
+
−   but WITHOUT ANY WARRANTY; without even the implied warranty of
+
−   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+
−   GNU General Public License for more details.
+
−
+
−   You should have received a copy of the GNU General Public License
+
−   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
−
+
−/* Written by Bruno Haible <bruno@clisp.org>, 2008.  */
+
−
+
−#include <config.h>
+
−
+
−#include <stdio.h>
+
−#include <stdlib.h>
+
−#include <sys/select.h>
+
−#include <sys/time.h>
+
−#include <unistd.h>
+
−
+
−int
+
−main (void)
+
−{
+
−  printf ("Applying select() from standard input. Press Ctrl-C to abort.\n");
+
−  for (;;)
+
−    {
+
−      struct timeval before;
+
−      struct timeval after;
+
−      unsigned long spent_usec;
+
−      fd_set readfds;
+
−      struct timeval timeout;
+
−      int ret;
+
−
+
−      gettimeofday (&before, NULL);
+
−
+
−      FD_ZERO (&readfds);
+
−      FD_SET (0, &readfds);
+
−      timeout.tv_sec = 0;
+
−      timeout.tv_usec = 500000;
+
−      ret = select (1, &readfds, NULL, NULL, &timeout);
+
−
+
−      gettimeofday (&after, NULL);
+
−      spent_usec = (after.tv_sec - before.tv_sec) * 1000000
+
−		   + after.tv_usec - before.tv_usec;
+
−
+
−      if (ret < 0)
+
−	{
+
−	  perror ("select failed");
+
−	  exit (1);
+
−	}
+
−      if ((ret == 0) != ! FD_ISSET (0, &readfds))
+
−	{
+
−	  fprintf (stderr, "incorrect return value\n");
+
−	  exit (1);
+
−	}
+
−      if (ret == 0)
+
−	{
+
−	  if (spent_usec < 250000)
+
−	    {
+
−	      fprintf (stderr, "returned too early\n");
+
−	      exit (1);
+
−	    }
+
−	  /* Timeout */
+
−	  printf ("."); fflush (stdout);
+
−	}
+
−      else
+
−	{
+
−	  char c;
+
−
+
−	  printf ("Input available! Trying to read 1 byte...\n");
+
−	  read (0, &c, 1);
+
−	}
+
−    }
+
−}