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[] = "from: @(#)ttyname.c 5.10 (Berkeley) 5/6/91";*/ 36 static char rcsid[] = "$Id: ttyname.c,v 1.4 1993/07/30 08:23:47 mycroft Exp $"; 37 #endif /* LIBC_SCCS and not lint */ 38 39 #include <sys/types.h> 40 #include <sys/stat.h> 41 #include <fcntl.h> 42 #include <dirent.h> 43 #include <sgtty.h> 44 #include <db.h> 45 #include <unistd.h> 46 #include <paths.h> 47 48 static char buf[sizeof(_PATH_DEV) + MAXNAMLEN] = _PATH_DEV; 49 50 char * 51 ttyname(fd) 52 int fd; 53 { 54 struct stat sb; 55 struct sgttyb ttyb; 56 DB *db; 57 DBT data, key; 58 struct { 59 mode_t type; 60 dev_t dev; 61 } bkey; 62 static char *__oldttyname(); 63 64 /* Must be a terminal. */ 65 if (ioctl(fd, TIOCGETP, &ttyb) < 0) 66 return(NULL); 67 /* Must be a character device. */ 68 if (fstat(fd, &sb) || !S_ISCHR(sb.st_mode)) 69 return(NULL); 70 71 if (db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL)) { 72 bkey.type = S_IFCHR; 73 bkey.dev = sb.st_rdev; 74 key.data = &bkey; 75 key.size = sizeof(bkey); 76 if (!(db->get)(db, &key, &data, 0)) { 77 bcopy(data.data, 78 buf + sizeof(_PATH_DEV) - 1, data.size); 79 return(buf); 80 } 81 } 82 return(__oldttyname(fd, &sb)); 83 } 84 85 static char * 86 __oldttyname(fd, sb) 87 int fd; 88 struct stat *sb; 89 { 90 register struct dirent *dirp; 91 register DIR *dp; 92 struct stat dsb; 93 char *rval, *strcpy(); 94 95 if ((dp = opendir(_PATH_DEV)) == NULL) 96 return(NULL); 97 98 for (rval = NULL; dirp = readdir(dp);) { 99 if (dirp->d_fileno != sb->st_ino) 100 continue; 101 bcopy(dirp->d_name, buf + sizeof(_PATH_DEV) - 1, 102 dirp->d_namlen + 1); 103 if (stat(buf, &dsb) || sb->st_dev != dsb.st_dev || 104 sb->st_ino != dsb.st_ino) 105 continue; 106 rval = buf; 107 break; 108 } 109 (void)closedir(dp); 110 return(rval); 111 } 112