code.delx.au - gnu-emacs/blob - lib/binary-io.h

   1 /* Binary mode I/O.
   2    Copyright (C) 2001, 2003, 2005, 2008-2015 Free Software Foundation,
   3    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 #ifndef _BINARY_H
  19 #define _BINARY_H
  20
  21 /* For systems that distinguish between text and binary I/O.
  22    O_BINARY is guaranteed by the gnulib <fcntl.h>. */
  23 #include <fcntl.h>
  24
  25 /* The MSVC7 <stdio.h> doesn't like to be included after '#define fileno ...',
  26    so we include it here first.  */
  27 #include <stdio.h>
  28
  29 #ifndef _GL_INLINE_HEADER_BEGIN
  30  #error "Please include config.h first."
  31 #endif
  32 _GL_INLINE_HEADER_BEGIN
  33 #ifndef BINARY_IO_INLINE
  34 # define BINARY_IO_INLINE _GL_INLINE
  35 #endif
  36
  37 /* set_binary_mode (fd, mode)
  38    sets the binary/text I/O mode of file descriptor fd to the given mode
  39    (must be O_BINARY or O_TEXT) and returns the previous mode.  */
  40 #if O_BINARY
  41 # if defined __EMX__ || defined __DJGPP__ || defined __CYGWIN__
  42 #  include <io.h> /* declares setmode() */
  43 #  define set_binary_mode setmode
  44 # else
  45 #  define set_binary_mode _setmode
  46 #  undef fileno
  47 #  define fileno _fileno
  48 # endif
  49 #else
  50   /* On reasonable systems, binary I/O is the only choice.  */
  51   /* Use a function rather than a macro, to avoid gcc warnings
  52      "warning: statement with no effect".  */
  53 BINARY_IO_INLINE int
  54 set_binary_mode (int fd, int mode)
  55 {
  56   (void) fd;
  57   (void) mode;
  58   return O_BINARY;
  59 }
  60 #endif
  61
  62 /* SET_BINARY (fd);
  63    changes the file descriptor fd to perform binary I/O.  */
  64 #ifdef __DJGPP__
  65 # include <unistd.h> /* declares isatty() */
  66   /* Avoid putting stdin/stdout in binary mode if it is connected to
  67      the console, because that would make it impossible for the user
  68      to interrupt the program through Ctrl-C or Ctrl-Break.  */
  69 # define SET_BINARY(fd) ((void) (!isatty (fd) ? (set_binary_mode (fd, O_BINARY), 0) : 0))
  70 #else
  71 # define SET_BINARY(fd) ((void) set_binary_mode (fd, O_BINARY))
  72 #endif
  73
  74 _GL_INLINE_HEADER_END
  75
  76 #endif /* _BINARY_H */