1 /* 2 * Copyright (c) 1988 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #if defined(LIBC_SCCS) && !defined(lint) 9 static char sccsid[] = "@(#)ttyname.c 5.9 (Berkeley) 03/06/91"; 10 #endif /* LIBC_SCCS and not lint */ 11 12 #include <sys/types.h> 13 #include <sys/stat.h> 14 #include <fcntl.h> 15 #include <dirent.h> 16 #include <sgtty.h> 17 #include <db.h> 18 #include <unistd.h> 19 #include <paths.h> 20 21 static char buf[sizeof(_PATH_DEV) + MAXNAMLEN] = _PATH_DEV; 22 23 char * 24 ttyname(fd) 25 int fd; 26 { 27 struct stat sb; 28 struct sgttyb ttyb; 29 DB *db; 30 DBT data, key; 31 static char *__oldttyname(); 32 33 /* Must be a terminal. */ 34 if (ioctl(fd, TIOCGETP, &ttyb) < 0) 35 return(NULL); 36 /* Must be a character device. */ 37 if (fstat(fd, &sb) || !S_ISCHR(sb.st_mode)) 38 return(NULL); 39 40 if (db = hash_open(_PATH_DEVDB, O_RDONLY, 0, NULL)) { 41 key.data = (u_char *)&sb.st_rdev; 42 key.size = sizeof(sb.st_rdev); 43 if (!(db->get)(db, &key, &data, 0)) { 44 bcopy(data.data, 45 buf + sizeof(_PATH_DEV) - 1, data.size); 46 return(buf); 47 } 48 } 49 return(__oldttyname(fd, &sb)); 50 } 51 52 static char * 53 __oldttyname(fd, sb) 54 int fd; 55 struct stat *sb; 56 { 57 register struct dirent *dirp; 58 register DIR *dp; 59 struct stat dsb; 60 char *rval, *strcpy(); 61 62 if ((dp = opendir(_PATH_DEV)) == NULL) 63 return(NULL); 64 65 for (rval = NULL; dirp = readdir(dp);) { 66 if (dirp->d_fileno != sb->st_ino) 67 continue; 68 bcopy(dirp->d_name, buf + sizeof(_PATH_DEV) - 1, 69 dirp->d_namlen + 1); 70 if (stat(buf, &dsb) || sb->st_dev != dsb.st_dev || 71 sb->st_ino != dsb.st_ino) 72 continue; 73 (void)closedir(dp); 74 rval = buf; 75 break; 76 } 77 (void)closedir(dp); 78 return(rval); 79 } 80