lib/binary-io.h

   1 /* Binary mode I/O.
   2    Copyright (C) 2001, 2003, 2005, 2008-2013 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 #ifndef _BINARY_H
  18 #define _BINARY_H
  19
  20 /* For systems that distinguish between text and binary I/O.
  21    O_BINARY is guaranteed by the gnulib <fcntl.h>. */
  22 #include <fcntl.h>
  23
  24 /* The MSVC7 <stdio.h> doesn't like to be included after '#define fileno ...',
  25    so we include it here first.  */
  26 #include <stdio.h>
  27
  28 _GL_INLINE_HEADER_BEGIN
  29 #ifndef BINARY_IO_INLINE
  30 # define BINARY_IO_INLINE _GL_INLINE
  31 #endif
  32
  33 /* set_binary_mode (fd, mode)
  34    sets the binary/text I/O mode of file descriptor fd to the given mode
  35    (must be O_BINARY or O_TEXT) and returns the previous mode.  */
  36 #if O_BINARY
  37 # if defined __EMX__ || defined __DJGPP__ || defined __CYGWIN__
  38 #  include <io.h> /* declares setmode() */
  39 #  define set_binary_mode setmode
  40 # else
  41 #  define set_binary_mode _setmode
  42 #  undef fileno
  43 #  define fileno _fileno
  44 # endif
  45 #else
  46   /* On reasonable systems, binary I/O is the only choice.  */
  47   /* Use a function rather than a macro, to avoid gcc warnings
  48      "warning: statement with no effect".  */
  49 BINARY_IO_INLINE int
  50 set_binary_mode (int fd, int mode)
  51 {
  52   (void) fd;
  53   (void) mode;
  54   return O_BINARY;
  55 }
  56 #endif
  57
  58 /* SET_BINARY (fd);
  59    changes the file descriptor fd to perform binary I/O.  */
  60 #ifdef __DJGPP__
  61 # include <unistd.h> /* declares isatty() */
  62   /* Avoid putting stdin/stdout in binary mode if it is connected to
  63      the console, because that would make it impossible for the user
  64      to interrupt the program through Ctrl-C or Ctrl-Break.  */
  65 # define SET_BINARY(fd) ((void) (!isatty (fd) ? (set_binary_mode (fd, O_BINARY), 0) : 0))
  66 #else
  67 # define SET_BINARY(fd) ((void) set_binary_mode (fd, O_BINARY))
  68 #endif
  69
  70 _GL_INLINE_HEADER_END
  71
  72 #endif /* _BINARY_H */