1 /* $NetBSD: ttyname.c,v 1.26 2012/06/12 18:17:04 joerg Exp $ */ 2 3 /* 4 * Copyright (c) 1988, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 #if 0 35 static char sccsid[] = "@(#)ttyname.c 8.2 (Berkeley) 1/27/94"; 36 #else 37 __RCSID("$NetBSD: ttyname.c,v 1.26 2012/06/12 18:17:04 joerg Exp $"); 38 #endif 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include "namespace.h" 42 #include <sys/ioctl.h> 43 #include <sys/stat.h> 44 45 #include <assert.h> 46 #include <errno.h> 47 #include <limits.h> 48 #include <paths.h> 49 #include <string.h> 50 #include <stdlib.h> 51 #include <termios.h> 52 #include <unistd.h> 53 54 #ifdef __weak_alias 55 __weak_alias(ttyname,_ttyname) 56 __weak_alias(ttyname_r,_ttyname_r) 57 #endif 58 59 int 60 ttyname_r(int fd, char *buf, size_t len) 61 { 62 struct stat sb; 63 struct termios ttyb; 64 struct ptmget ptm; 65 66 _DIAGASSERT(fd != -1); 67 68 /* If it is a pty, deal with it quickly */ 69 if (ioctl(fd, TIOCPTSNAME, &ptm) != -1) { 70 if (strlcpy(buf, ptm.sn, len) >= len) { 71 return ERANGE; 72 } 73 return 0; 74 } 75 76 /* Must be a terminal. */ 77 if (tcgetattr(fd, &ttyb) == -1) 78 return errno; 79 80 if (fstat(fd, &sb)) 81 return errno; 82 83 if (strlcpy(buf, _PATH_DEV, len) >= len) 84 return ERANGE; 85 buf += strlen(_PATH_DEV); 86 len -= strlen(_PATH_DEV); 87 return devname_r(sb.st_rdev, sb.st_mode & S_IFMT, buf, len); 88 } 89 90 char * 91 ttyname(int fd) 92 { 93 static char buf[PATH_MAX]; 94 int rv; 95 96 rv = ttyname_r(fd, buf, sizeof(buf)); 97 if (rv != 0) { 98 errno = rv; 99 return NULL; 100 } 101 return buf; 102 } 103