newlib/libc/unix/ttyname_r.c

   1 #ifndef _NO_TTYNAME
   2 /*
   3  * Copyright (c) 1988 The Regents of the University of California.
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 4. Neither the name of the University nor the names of its contributors
  15  *    may be used to endorse or promote products derived from this software
  16  *    without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  */
  30
  31 #include "ttyname.h"
  32
  33 #include <sys/types.h>
  34 #include <sys/stat.h>
  35 #include <fcntl.h>
  36 #include <dirent.h>
  37 #include <unistd.h>
  38 #include <string.h>
  39 #include <paths.h>
  40 #include <_syslist.h>
  41 #include <errno.h>
  42
  43 /*
  44  *  ttyname_r() - POSIX 1003.1b 4.7.2 - Determine Terminal Device Name
  45  */
  46 int
  47  ttyname_r (int fd,
  48         char   *name,
  49         size_t  namesize)
  50 {
  51   struct stat sb;
  52   struct dirent *dirp;
  53   DIR *dp;
  54   struct stat dsb;
  55   char buf[TTYNAME_BUFSIZE];
  56
  57   /* Must be a terminal. */
  58   if (!isatty(fd))
  59     return ENOTTY;
  60
  61   /* Must be a character device. */
  62   if (fstat (fd, &sb) || !S_ISCHR (sb.st_mode))
  63     return ENOTTY;
  64
  65   if ((dp = opendir (_PATH_DEV)) == NULL)
  66     return EBADF;
  67
  68   strcpy(buf, _PATH_DEV);
  69   while ((dirp = readdir (dp)) != NULL)
  70     {
  71       if (dirp->d_ino != sb.st_ino)
  72         continue;
  73       strcpy (buf + sizeof (_PATH_DEV) - 1, dirp->d_name);
  74       if (stat (buf, &dsb) || sb.st_dev != dsb.st_dev ||
  75           sb.st_ino != dsb.st_ino)
  76         continue;
  77       (void) closedir (dp);
  78       if(strlen(buf) < namesize)  /* < to account for terminating null */
  79         {
  80         strcpy(name, buf);
  81         return 0;
  82         }
  83       else
  84         {
  85         return ERANGE;
  86         }
  87     }
  88   (void) closedir (dp);
  89   return EBADF;
  90 }
  91
  92 #endif /* !_NO_TTYNAME  */