1/*-
2 * Copyright (c) 2010 Jilles Tjoelker
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD$
27 */
28
29#include <sys/select.h>
30
31#include <err.h>
32#include <stdio.h>
33#include <unistd.h>
34
35/*
36 * Check that pipes can be selected for writing in the reverse direction.
37 */
38int
39main(void)
40{
41	int pip[2];
42	fd_set set;
43	int n;
44
45	if (pipe(pip) == -1)
46		err(1, "FAIL: pipe");
47
48	FD_ZERO(&set);
49	FD_SET(pip[0], &set);
50	n = select(pip[1] + 1, NULL, &set, NULL, &(struct timeval){ 0, 0 });
51	if (n != 1)
52		errx(1, "FAIL: select initial reverse direction");
53
54	n = write(pip[0], "x", 1);
55	if (n != 1)
56		err(1, "FAIL: write reverse direction");
57
58	FD_ZERO(&set);
59	FD_SET(pip[0], &set);
60	n = select(pip[1] + 1, NULL, &set, NULL, &(struct timeval){ 0, 0 });
61	if (n != 1)
62		errx(1, "FAIL: select reverse direction after write");
63
64	printf("PASS\n");
65
66	return (0);
67}
68