sysdeps/unix/sysv/linux/fd_to_filename.h

   1 /* Query filename corresponding to an open FD.  Linux version.
   2    Copyright (C) 2001-2017 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <stdlib.h>
  20 #include <string.h>
  21 #include <sys/stat.h>
  22 #include <_itoa.h>
  23
  24 static inline const char *
  25 fd_to_filename (int fd)
  26 {
  27   char *ret = malloc (30);
  28
  29   if (ret != NULL)
  30     {
  31       struct stat64 st;
  32
  33       *_fitoa_word (fd, __stpcpy (ret, "/proc/self/fd/"), 10, 0) = '\0';
  34
  35       /* We must make sure the file exists.  */
  36       if (__lxstat64 (_STAT_VER, ret, &st) < 0)
  37         {
  38           /* /proc is not mounted or something else happened.  Don't
  39              return the file name.  */
  40           free (ret);
  41           ret = NULL;
  42         }
  43     }
  44   return ret;
  45 }