lib/binary-io.h

   1 /* Binary mode I/O.
   2    Copyright (C) 2001, 2003, 2005, 2008-2019 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 <https://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 #if O_BINARY
  38 # if defined __EMX__ || defined __DJGPP__ || defined __CYGWIN__
  39 #  include <io.h> /* declares setmode() */
  40 #  define __gl_setmode setmode
  41 # else
  42 #  define __gl_setmode _setmode
  43 #  undef fileno
  44 #  define fileno _fileno
  45 # endif
  46 #else
  47   /* On reasonable systems, binary I/O is the only choice.  */
  48   /* Use a function rather than a macro, to avoid gcc warnings
  49      "warning: statement with no effect".  */
  50 BINARY_IO_INLINE int
  51 __gl_setmode (int fd, int mode)
  52 {
  53   (void) fd;
  54   (void) mode;
  55   return O_BINARY;
  56 }
  57 #endif
  58
  59 #if defined __DJGPP__ || defined __EMX__
  60 extern int __gl_setmode_check (int);
  61 #else
  62 BINARY_IO_INLINE int
  63 __gl_setmode_check (int fd) { return 0; }
  64 #endif
  65
  66 /* Set FD's mode to MODE, which should be either O_TEXT or O_BINARY.
  67    Return the old mode if successful, -1 (setting errno) on failure.
  68    Ordinarily this function would be called 'setmode', since that is
  69    its name on MS-Windows, but it is called 'set_binary_mode' here
  70    to avoid colliding with a BSD function of another name.  */
  71
  72 BINARY_IO_INLINE int
  73 set_binary_mode (int fd, int mode)
  74 {
  75   int r = __gl_setmode_check (fd);
  76   return r != 0 ? r : __gl_setmode (fd, mode);
  77 }
  78
  79 /* This macro is obsolescent.  */
  80 #define SET_BINARY(fd) ((void) set_binary_mode (fd, O_BINARY))
  81
  82 _GL_INLINE_HEADER_END
  83
  84 #endif /* _BINARY_H */