1 /* Copyright (C) 2001-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library 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 GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #include <sys/ioctl.h>
19 #include <sys/socket.h>
20
21 /* Determine whether socket is at a out-of-band mark. */
22 int
sockatmark(int fd)23 sockatmark (int fd)
24 {
25 int answ;
26
27 return __ioctl (fd, SIOCATMARK, &answ) == -1 ? -1 : answ;
28 }
29