lib/binary-io.h

   1 /* Binary mode I/O.
   2    Copyright (C) 2001, 2003, 2005, 2008-2017 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 <https://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 #ifndef _GL_INLINE_HEADER_BEGIN
  29  #error "Please include config.h first."
  30 #endif
  31 _GL_INLINE_HEADER_BEGIN
  32 #ifndef BINARY_IO_INLINE
  33 # define BINARY_IO_INLINE _GL_INLINE
  34 #endif
  35
  36 #if O_BINARY
  37 # if defined __EMX__ || defined __DJGPP__ || defined __CYGWIN__
  38 #  include <io.h> /* declares setmode() */
  39 #  define __gl_setmode setmode
  40 # else
  41 #  define __gl_setmode _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 __gl_setmode (int fd, int mode)
  51 {
  52   (void) fd;
  53   (void) mode;
  54   return O_BINARY;
  55 }
  56 #endif
  57
  58 #if defined __DJGPP__ || defined __EMX__
  59 extern int __gl_setmode_check (int);
  60 #else
  61 BINARY_IO_INLINE int
  62 __gl_setmode_check (int fd) { return 0; }
  63 #endif
  64
  65 /* Set FD's mode to MODE, which should be either O_TEXT or O_BINARY.
  66    Return the old mode if successful, -1 (setting errno) on failure.
  67    Ordinarily this function would be called 'setmode', since that is
  68    its name on MS-Windows, but it is called 'set_binary_mode' here
  69    to avoid colliding with a BSD function of another name.  */
  70
  71 BINARY_IO_INLINE int
  72 set_binary_mode (int fd, int mode)
  73 {
  74   int r = __gl_setmode_check (fd);
  75   return r != 0 ? r : __gl_setmode (fd, mode);
  76 }
  77
  78 /* This macro is obsolescent.  */
  79 #define SET_BINARY(fd) ((void) set_binary_mode (fd, O_BINARY))
  80
  81 _GL_INLINE_HEADER_END
  82
  83 #endif /* _BINARY_H */