toolchain/gcc/newlib/libc/unix/ttyname.c

   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[] = "@(#)ttyname.c   5.10 (Berkeley) 5/6/91";
  36 #endif /* LIBC_SCCS and not lint */
  37
  38 #include <sys/types.h>
  39 #include <sys/stat.h>
  40 #include <fcntl.h>
  41 #include <dirent.h>
  42 #include <termios.h>
  43 #include <unistd.h>
  44 #include <string.h>
  45 #include <paths.h>
  46 #include <_syslist.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 termios tty;
  56   struct dirent *dirp;
  57   DIR *dp;
  58   struct stat dsb;
  59   char *rval;
  60
  61   /* Must be a terminal. */
  62   if (tcgetattr (fd, &tty) < 0)
  63     return NULL;
  64
  65   /* Must be a character device. */
  66   if (_fstat (fd, &sb) || !S_ISCHR (sb.st_mode))
  67     return NULL;
  68
  69   if ((dp = _opendir (_PATH_DEV)) == NULL)
  70     return NULL;
  71
  72   for (rval = NULL; dirp = _readdir (dp);)
  73     {
  74       if (dirp->d_ino != sb.st_ino)
  75         continue;
  76       strcpy (buf + sizeof (_PATH_DEV) - 1, dirp->d_name);
  77       if (stat (buf, &dsb) || sb.st_dev != dsb.st_dev ||
  78           sb.st_ino != dsb.st_ino)
  79         continue;
  80       (void) _closedir (dp);
  81       rval = buf;
  82       break;
  83     }
  84   (void) _closedir (dp);
  85   return rval;
  86 }