1 /* $NetBSD: ttyname.c,v 1.26 2012/06/12 18:17:04 joerg Exp $ */
2
3 /*
4 * Copyright (c) 1988, 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[] = "@(#)ttyname.c 8.2 (Berkeley) 1/27/94";
36 #else
37 __RCSID("$NetBSD: ttyname.c,v 1.26 2012/06/12 18:17:04 joerg Exp $");
38 #endif
39 #endif /* LIBC_SCCS and not lint */
40
41 #include "namespace.h"
42 #include <sys/ioctl.h>
43 #include <sys/stat.h>
44
45 #include <assert.h>
46 #include <errno.h>
47 #include <limits.h>
48 #include <paths.h>
49 #include <string.h>
50 #include <stdlib.h>
51 #include <termios.h>
52 #include <unistd.h>
53
54 #ifdef __weak_alias
__weak_alias(ttyname,_ttyname)55 __weak_alias(ttyname,_ttyname)
56 __weak_alias(ttyname_r,_ttyname_r)
57 #endif
58
59 int
60 ttyname_r(int fd, char *buf, size_t len)
61 {
62 struct stat sb;
63 struct termios ttyb;
64 struct ptmget ptm;
65
66 _DIAGASSERT(fd != -1);
67
68 /* If it is a pty, deal with it quickly */
69 if (ioctl(fd, TIOCPTSNAME, &ptm) != -1) {
70 if (strlcpy(buf, ptm.sn, len) >= len) {
71 return ERANGE;
72 }
73 return 0;
74 }
75
76 /* Must be a terminal. */
77 if (tcgetattr(fd, &ttyb) == -1)
78 return errno;
79
80 if (fstat(fd, &sb))
81 return errno;
82
83 if (strlcpy(buf, _PATH_DEV, len) >= len)
84 return ERANGE;
85 buf += strlen(_PATH_DEV);
86 len -= strlen(_PATH_DEV);
87 return devname_r(sb.st_rdev, sb.st_mode & S_IFMT, buf, len);
88 }
89
90 char *
ttyname(int fd)91 ttyname(int fd)
92 {
93 static char buf[PATH_MAX];
94 int rv;
95
96 rv = ttyname_r(fd, buf, sizeof(buf));
97 if (rv != 0) {
98 errno = rv;
99 return NULL;
100 }
101 return buf;
102 }
103