1 /* Test of SIGPIPE handling.
2 Copyright (C) 2008-2020 Free Software Foundation, Inc.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 3, or (at your option)
7 any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, see <https://www.gnu.org/licenses/>. */
16
17 #include <config.h>
18
19 #include <signal.h>
20
21 /* Check that SIGPIPE is defined. */
22 int s = SIGPIPE;
23
24 #include <errno.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <unistd.h>
28
29 #include "macros.h"
30
31 static void
handler(int sig)32 handler (int sig)
33 {
34 exit (0);
35 }
36
37 int
main(int argc,char ** argv)38 main (int argc, char **argv)
39 {
40 char mode = argv[1][0];
41
42 switch (mode)
43 {
44 case 'A': signal (SIGPIPE, SIG_DFL); break;
45 case 'B': signal (SIGPIPE, SIG_IGN); break;
46 case 'C': signal (SIGPIPE, handler); break;
47 }
48
49 /* Produce infinite output. Since it is piped into "head -1", the writes
50 must ultimately fail. */
51 for (;;)
52 {
53 char c[2] = { 'y', '\n' };
54 int ret = write (1, c, sizeof (c));
55 if (ret <= 0)
56 {
57 switch (mode)
58 {
59 case 'B': /* The write() call should have failed with EPIPE. */
60 if (ret < 0 && errno == EPIPE)
61 exit (0);
62 FALLTHROUGH;
63 case 'A': /* The process should silently die. */
64 case 'C': /* The handler should have been called. */
65 fprintf (stderr, "write() returned %d with error %d.\n", ret, errno);
66 exit (1);
67 }
68 }
69 }
70 }
71