1 /* $NetBSD: tcgetpgrp.c,v 1.10 2012/06/25 22:32:46 abs 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
35 static char sccsid[] = "@(#)termios.c 8.2 (Berkeley) 2/21/94";
36 #else
37 __RCSID("$NetBSD: tcgetpgrp.c,v 1.10 2012/06/25 22:32:46 abs 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
__weak_alias(tcgetpgrp,_tcgetpgrp)51 __weak_alias(tcgetpgrp,_tcgetpgrp)
52 #endif
53
54 pid_t
55 tcgetpgrp(int fd)
56 {
57 int s;
58
59 _DIAGASSERT(fd != -1);
60
61 if (ioctl(fd, TIOCGPGRP, &s) < 0)
62 return ((pid_t)-1);
63
64 if (s == (pid_t)-1)
65 /* SVID requires a number > 1 that isn't a valid PGID... */
66 s = (uint)(pid_t)~0u >> 1;
67 return ((pid_t)s);
68 }
69