1 /*
2 * Copyright (c) 1988 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)ttyname.c 5.10 (Berkeley) 5/6/91";
36 #endif /* LIBC_SCCS and not lint */
37
38 #include <sys/types.h>
39 #include <sys/stat.h>
40 #include <fcntl.h>
41 #include <dirent.h>
42 #include <sgtty.h>
43 #include <db.h>
44 #include <unistd.h>
45 #include <paths.h>
46
47 static char buf[sizeof(_PATH_DEV) + MAXNAMLEN] = _PATH_DEV;
48
49 char *
ttyname(fd)50 ttyname(fd)
51 int fd;
52 {
53 struct stat sb;
54 struct sgttyb ttyb;
55 DB *db;
56 DBT data, key;
57 struct {
58 mode_t type;
59 dev_t dev;
60 } bkey;
61 static char *__oldttyname();
62
63 /* Must be a terminal. */
64 if (ioctl(fd, TIOCGETP, &ttyb) < 0)
65 return(NULL);
66 /* Must be a character device. */
67 if (fstat(fd, &sb) || !S_ISCHR(sb.st_mode))
68 return(NULL);
69
70 if (db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL)) {
71 bkey.type = S_IFCHR;
72 bkey.dev = sb.st_rdev;
73 key.data = &bkey;
74 key.size = sizeof(bkey);
75 if (!(db->get)(db, &key, &data, 0)) {
76 bcopy(data.data,
77 buf + sizeof(_PATH_DEV) - 1, data.size);
78 return(buf);
79 }
80 }
81 return(__oldttyname(fd, &sb));
82 }
83
84 static char *
__oldttyname(fd,sb)85 __oldttyname(fd, sb)
86 int fd;
87 struct stat *sb;
88 {
89 register struct dirent *dirp;
90 register DIR *dp;
91 struct stat dsb;
92 char *rval, *strcpy();
93
94 if ((dp = opendir(_PATH_DEV)) == NULL)
95 return(NULL);
96
97 for (rval = NULL; dirp = readdir(dp);) {
98 if (dirp->d_fileno != sb->st_ino)
99 continue;
100 bcopy(dirp->d_name, buf + sizeof(_PATH_DEV) - 1,
101 dirp->d_namlen + 1);
102 if (stat(buf, &dsb) || sb->st_dev != dsb.st_dev ||
103 sb->st_ino != dsb.st_ino)
104 continue;
105 rval = buf;
106 break;
107 }
108 (void)closedir(dp);
109 return(rval);
110 }
111