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
27 #include <sys/select.h>
28
29 #include <err.h>
30 #include <stdio.h>
31 #include <unistd.h>
32
33 /*
34 * Check that pipes can be selected for writing in the reverse direction.
35 */
36 int
main(void)37 main(void)
38 {
39 int pip[2];
40 fd_set set;
41 int n;
42
43 if (pipe(pip) == -1)
44 err(1, "FAIL: pipe");
45
46 FD_ZERO(&set);
47 FD_SET(pip[0], &set);
48 n = select(pip[1] + 1, NULL, &set, NULL, &(struct timeval){ 0, 0 });
49 if (n != 1)
50 errx(1, "FAIL: select initial reverse direction");
51
52 n = write(pip[0], "x", 1);
53 if (n != 1)
54 err(1, "FAIL: write reverse direction");
55
56 FD_ZERO(&set);
57 FD_SET(pip[0], &set);
58 n = select(pip[1] + 1, NULL, &set, NULL, &(struct timeval){ 0, 0 });
59 if (n != 1)
60 errx(1, "FAIL: select reverse direction after write");
61
62 printf("PASS\n");
63
64 return (0);
65 }
66