1/*	$NetBSD: tcgetpgrp.c,v 1.8 2003/08/07 16:44:13 agc Exp $	*/
2
3/*-
4 * Copyright (c) 1989, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#if defined(LIBC_SCCS) && !defined(lint)
34#if 0
35static char sccsid[] = "@(#)termios.c	8.2 (Berkeley) 2/21/94";
36#else
37__RCSID("$NetBSD: tcgetpgrp.c,v 1.8 2003/08/07 16:44:13 agc Exp $");
38#endif
39#endif /* LIBC_SCCS and not lint */
40
41#include "namespace.h"
42#include <sys/types.h>
43#include <sys/ioctl.h>
44
45#include <assert.h>
46#include <errno.h>
47#include <termios.h>
48#include <unistd.h>
49
50#ifdef __weak_alias
51__weak_alias(tcgetpgrp,_tcgetpgrp)
52#endif
53
54pid_t
55tcgetpgrp(fd)
56	int fd;
57{
58	int s;
59
60	_DIAGASSERT(fd != -1);
61
62	if (ioctl(fd, TIOCGPGRP, &s) < 0)
63		return ((pid_t)-1);
64
65	if (s == (pid_t)-1)
66		/* SVID requires a number > 1 that isn't a valid PGID... */
67		s = (uint)(pid_t)~0u >> 1;
68	return ((pid_t)s);
69}
70