contrib/diffutils-2.8.1/lib/setmode.c

   1 /* Set a file descriptor's mode to binary or to text.
   2
   3    Copyright (C) 2001 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 2, or (at your option)
   8    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; see the file COPYING.
  17    If not, write to the Free Software Foundation,
  18    59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  19
  20 /* Written by Paul Eggert <eggert@twinsun.com>  */
  21
  22 #if HAVE_CONFIG_H
  23 # include <config.h>
  24 #endif
  25
  26 #if HAVE_STDBOOL_H
  27 # include <stdbool.h>
  28 #else
  29 typedef enum {false = 0, true = 1} bool;
  30 #endif
  31
  32 #if HAVE_SETMODE_DOS
  33 # include <io.h>
  34 # if HAVE_FCNTL_H
  35 #  include <fcntl.h>
  36 # endif
  37 # if HAVE_UNISTD_H
  38 #  include <unistd.h>
  39 # endif
  40 #endif
  41
  42 #include "setmode.h"
  43 #undef set_binary_mode
  44
  45
  46 /* Set the binary mode of FD to MODE, returning its previous mode.
  47    MODE is 1 for binary and 0 for text.  If setting the mode might
  48    cause problems, ignore the request and return MODE.  Always return
  49    1 on POSIX platforms, which do not distinguish between text and
  50    binary.  */
  51
  52 bool
  53 set_binary_mode (int fd, bool mode)
  54 {
  55 #if HAVE_SETMODE_DOS
  56   if (isatty (fd))
  57     return mode;
  58   return setmode (fd, mode ? O_BINARY : O_TEXT) != O_TEXT;
  59 #else
  60   return 1;
  61 #endif
  62 }