1/* Copyright (C) 1991-2021 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 <errno.h>
20#include <unistd.h>
21#include <sys/types.h>
22
23/* Return the foreground process group ID of FD. */
24pid_t
25tcgetpgrp (int fd)
26{
27 int pgrp;
28
29 if (__ioctl (fd, TIOCGPGRP, &pgrp) < 0)
30 return (pid_t) -1;
31 return (pid_t) pgrp;
32}
33libc_hidden_def (tcgetpgrp)
34