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 1.7 1994/01/28 01:19:11 cgd 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 <string.h> 46 #include <unistd.h> 47 #include <paths.h> 48 49 static char buf[sizeof(_PATH_DEV) + MAXNAMLEN] = _PATH_DEV; 50 51 char * 52 ttyname(fd) 53 int fd; 54 { 55 struct stat sb; 56 struct sgttyb ttyb; 57 DB *db; 58 DBT data, key; 59 struct { 60 mode_t type; 61 dev_t dev; 62 } bkey; 63 static char *__oldttyname(); 64 65 /* Must be a terminal. */ 66 if (ioctl(fd, TIOCGETP, &ttyb) < 0) 67 return(NULL); 68 /* Must be a character device. */ 69 if (fstat(fd, &sb) || !S_ISCHR(sb.st_mode)) 70 return(NULL); 71 72 if (db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL)) { 73 bkey.type = S_IFCHR; 74 bkey.dev = sb.st_rdev; 75 key.data = &bkey; 76 key.size = sizeof(bkey); 77 if (!(db->get)(db, &key, &data, 0)) { 78 bcopy(data.data, 79 buf + sizeof(_PATH_DEV) - 1, data.size); 80 (void)(db->close)(db); 81 return(buf); 82 } 83 (void)(db->close)(db); 84 } 85 return(__oldttyname(fd, &sb)); 86 } 87 88 static char * 89 __oldttyname(fd, sb) 90 int fd; 91 struct stat *sb; 92 { 93 register struct dirent *dirp; 94 register DIR *dp; 95 struct stat dsb; 96 char *rval, *strcpy(); 97 98 if ((dp = opendir(_PATH_DEV)) == NULL) 99 return(NULL); 100 101 for (rval = NULL; dirp = readdir(dp);) { 102 if (dirp->d_fileno != sb->st_ino) 103 continue; 104 bcopy(dirp->d_name, buf + sizeof(_PATH_DEV) - 1, 105 dirp->d_namlen + 1); 106 if (stat(buf, &dsb) || sb->st_dev != dsb.st_dev || 107 sb->st_ino != dsb.st_ino) 108 continue; 109 rval = buf; 110 break; 111 } 112 (void)closedir(dp); 113 return(rval); 114 } 115