freebsd-dev/lib/libc/gen/ttyname.c
1994-05-27 05:00:24 +00:00

113 lines
3.4 KiB
C

/*
* Copyright (c) 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)ttyname.c 8.2 (Berkeley) 1/27/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#include <sgtty.h>
#include <db.h>
#include <string.h>
#include <paths.h>
static char buf[sizeof(_PATH_DEV) + MAXNAMLEN] = _PATH_DEV;
static char *oldttyname __P((int, struct stat *));
char *
ttyname(fd)
int fd;
{
struct stat sb;
struct sgttyb ttyb;
DB *db;
DBT data, key;
struct {
mode_t type;
dev_t dev;
} bkey;
/* Must be a terminal. */
if (ioctl(fd, TIOCGETP, &ttyb) < 0)
return (NULL);
/* Must be a character device. */
if (fstat(fd, &sb) || !S_ISCHR(sb.st_mode))
return (NULL);
if (db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL)) {
memset(&bkey, 0, sizeof(bkey));
bkey.type = S_IFCHR;
bkey.dev = sb.st_rdev;
key.data = &bkey;
key.size = sizeof(bkey);
if (!(db->get)(db, &key, &data, 0)) {
bcopy(data.data,
buf + sizeof(_PATH_DEV) - 1, data.size);
(void)(db->close)(db);
return (buf);
}
(void)(db->close)(db);
}
return (oldttyname(fd, &sb));
}
static char *
oldttyname(fd, sb)
int fd;
struct stat *sb;
{
register struct dirent *dirp;
register DIR *dp;
struct stat dsb;
if ((dp = opendir(_PATH_DEV)) == NULL)
return (NULL);
while (dirp = readdir(dp)) {
if (dirp->d_fileno != sb->st_ino)
continue;
bcopy(dirp->d_name, buf + sizeof(_PATH_DEV) - 1,
dirp->d_namlen + 1);
if (stat(buf, &dsb) || sb->st_dev != dsb.st_dev ||
sb->st_ino != dsb.st_ino)
continue;
(void)closedir(dp);
return (buf);
}
(void)closedir(dp);
return (NULL);
}