gnulib/import/dup.c

   1 /* Duplicate an open file descriptor.
   2
   3    Copyright (C) 2011-2016 Free Software Foundation, Inc.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program 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
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 #include <config.h>
  19
  20 /* Specification.  */
  21 #include <unistd.h>
  22
  23 #include <errno.h>
  24
  25 #include "msvc-inval.h"
  26
  27 #undef dup
  28
  29 #if HAVE_MSVC_INVALID_PARAMETER_HANDLER
  30 static int
  31 dup_nothrow (int fd)
  32 {
  33   int result;
  34
  35   TRY_MSVC_INVAL
  36     {
  37       result = dup (fd);
  38     }
  39   CATCH_MSVC_INVAL
  40     {
  41       result = -1;
  42       errno = EBADF;
  43     }
  44   DONE_MSVC_INVAL;
  45
  46   return result;
  47 }
  48 #elif defined __KLIBC__
  49 # include <fcntl.h>
  50 # include <sys/stat.h>
  51
  52 # include <InnoTekLIBC/backend.h>
  53
  54 static int
  55 dup_nothrow (int fd)
  56 {
  57   int dupfd;
  58   struct stat sbuf;
  59
  60   dupfd = dup (fd);
  61   if (dupfd == -1 && errno == ENOTSUP \
  62       && !fstat (fd, &sbuf) && S_ISDIR (sbuf.st_mode))
  63     {
  64       char path[_MAX_PATH];
  65
  66       /* Get a path from fd */
  67       if (!__libc_Back_ioFHToPath (fd, path, sizeof (path)))
  68         dupfd = open (path, O_RDONLY);
  69     }
  70
  71   return dupfd;
  72 }
  73 #else
  74 # define dup_nothrow dup
  75 #endif
  76
  77 int
  78 rpl_dup (int fd)
  79 {
  80   int result = dup_nothrow (fd);
  81 #if REPLACE_FCHDIR
  82   if (result >= 0)
  83     result = _gl_register_dup (fd, result);
  84 #endif
  85   return result;
  86 }