gnu/dist/diffutils/lib/setmode.c

   1 /*      $NetBSD$        */
   2
   3 /* Set a file descriptor's mode to binary or to text.
   4
   5    Copyright (C) 2001 Free Software Foundation, Inc.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2, or (at your option)
  10    any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; see the file COPYING.
  19    If not, write to the Free Software Foundation,
  20    59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  21
  22 /* Written by Paul Eggert <eggert@twinsun.com>  */
  23
  24 #if HAVE_CONFIG_H
  25 # include <config.h>
  26 #endif
  27
  28 #if HAVE_STDBOOL_H
  29 # include <stdbool.h>
  30 #else
  31 typedef enum {false = 0, true = 1} bool;
  32 #endif
  33
  34 #if HAVE_SETMODE_DOS
  35 # include <io.h>
  36 # if HAVE_FCNTL_H
  37 #  include <fcntl.h>
  38 # endif
  39 # if HAVE_UNISTD_H
  40 #  include <unistd.h>
  41 # endif
  42 #endif
  43
  44 #include "setmode.h"
  45 #undef set_binary_mode
  46
  47
  48 /* Set the binary mode of FD to MODE, returning its previous mode.
  49    MODE is 1 for binary and 0 for text.  If setting the mode might
  50    cause problems, ignore the request and return MODE.  Always return
  51    1 on POSIX platforms, which do not distinguish between text and
  52    binary.  */
  53
  54 bool
  55 set_binary_mode (int fd, bool mode)
  56 {
  57 #if HAVE_SETMODE_DOS
  58   if (isatty (fd))
  59     return mode;
  60   return setmode (fd, mode ? O_BINARY : O_TEXT) != O_TEXT;
  61 #else
  62   return 1;
  63 #endif
  64 }