xref: /illumos-gate/usr/src/lib/libc/port/gen/tcgetsid.c (revision 4db555a5389470c6f15aa8b50a38ca5d533d0641)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #pragma weak _tcgetsid = tcgetsid
33 
34 #include "lint.h"
35 #include <sys/termios.h>
36 #include <sys/types.h>
37 #include <errno.h>
38 #include <unistd.h>
39 
40 pid_t
41 tcgetsid(int fd)
42 {
43 	pid_t ttysid, mysid;
44 
45 	if ((ioctl(fd, TIOCGSID, &ttysid)) < 0 ||
46 	    (mysid = getsid(0)) < 0)
47 		return (-1);
48 	if (mysid != ttysid) {
49 		errno = ENOTTY;
50 		return (-1);
51 	}
52 	return (mysid);
53 }
54