1 /* Test of select() substitute, reading or writing from a given file descriptor.
2 Copyright (C) 2008 Free Software Foundation, Inc.
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 of the License, or
7 (at your option) any later version.
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.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
17 /* Written by Bruno Haible <bruno@clisp.org>, 2008. */
23 #include <sys/select.h>
26 main (int argc, char *argv[])
30 char mode = argv[1][0];
32 if (mode == 'r' || mode == 'w')
34 int fd = atoi (argv[2]);
39 struct timeval timeout;
45 timeout.tv_usec = 10000;
47 ? select (fd + 1, &fds, NULL, NULL, &timeout)
48 : select (fd + 1, NULL, &fds, NULL, &timeout));
51 perror ("select failed");
54 if ((ret == 0) != ! FD_ISSET (fd, &fds))
56 fprintf (stderr, "incorrect return value\n");
59 fprintf (stderr, "%d\n", ret);
64 fprintf (stderr, "Usage: test-select-fd mode fd\n");