/*

 * © Portions copyright (c) 2006-2007 Nokia Corporation.  All rights reserved.

 *

 * Copyright (c) 1999

 * Silicon Graphics Computer Systems, Inc.

 *

 * Copyright (c) 1999 

 * Boris Fomitchev

 *

 * This material is provided "as is", with absolutely no warranty expressed

 * or implied. Any use is at your own risk.

 *

 * Permission to use or copy this software for any purpose is hereby granted 

 * without fee, provided the above notices are retained on all copies.

 * Permission to modify the code and to distribute modified code is granted,

 * provided the above notices are retained, and a notice that the code was

 * modified is included with the above copyright notice.

 *

 */ 

// WARNING: This is an internal header file, included by other C++

// standard library headers.  You should not attempt to use this header

// file directly.

#ifndef _STLP_STDIO_FILE_H

#define _STLP_STDIO_FILE_H

// This file provides a low-level interface between the internal 

// representation of struct FILE, from the C stdio library, and 

// the C++ I/O library.  The C++ I/O library views a FILE object as

// a collection of three pointers: the beginning of the buffer, the

// current read/write position, and the end of the buffer.

// The interface:

// - char* _FILE_[IO]_begin(const FILE *__f);

//       Returns a pointer to the beginning of the buffer.

// - char* _FILE_[IO]_next(const FILE *__f);

//       Returns the current read/write position within the buffer.

// - char* _FILE_[IO]_end(const FILE *__f);

//       Returns a pointer immediately past the end of the buffer.

// - char* _FILE_[IO]_avail(const FILE *__f);

//       Returns the number of characters remaining in the buffer, i.e.

//       _FILE_[IO]_end(__f) - _FILE_[IO]_next(__f).

// - char& _FILE_[IO]_preincr(FILE *__f)

//       Increments the current read/write position by 1, returning the 

//       character at the old position.

// - char& _FILE_[IO]_postincr(FILE *__f)

//       Increments the current read/write position by 1, returning the 

//       character at the old position.

// - char& _FILE_[IO]_predecr(FILE *__f)

//       Decrements the current read/write position by 1, returning the 

//       character at the old position.

// - char& _FILE_[IO]_postdecr(FILE *__f)

//       Decrements the current read/write position by 1, returning the 

//       character at the old position.

// - void _FILE_[IO]_bump(FILE *__f, int __n)

//       Increments the current read/write position by __n.

// - void _FILE_[IO]_set(FILE *__f, char* __begin, char* __next, char* __end);

//       Sets the beginning of the bufer to __begin, the current read/write

//       position to __next, and the buffer's past-the-end pointer to __end.

//       If any of those pointers is null, then all of them must be null.

// Each function comes in two versions, one for a FILE used as an input

// buffer and one for a FILE used as an output buffer.  In some stdio

// implementations the two functions are identical, but in others they are

// not.

#ifndef _STLP_CSTDIO

# include <cstdio>

#endif

#ifndef _STLP_CSTDDEF

# include <cstddef>

#endif

#if defined(__MSL__)

# include <unix.h>	// get the definition of fileno

#endif

_STLP_BEGIN_NAMESPACE

#if !defined(_STLP_WINCE)

//----------------------------------------------------------------------

// Implementation for the IRIX C library.

// Solaris interface looks to be identical.

#if !defined(_STLP_USE_GLIBC) && \

    ( defined(__sgi) || \

      ( defined(__sun) && ! defined (_LP64) )  || \

      defined (__osf__) || defined(__DECCXX) || \

      defined (_STLP_MSVC) || defined (__ICL) || defined (__MINGW32__) || defined(__DJGPP) ||\

      defined (_AIX) || defined (_CRAY))

#if defined ( _MSC_VER ) || defined (__ICL) || defined (__MINGW32__) || defined(__DJGPP)

typedef  char* _File_ptr_type;

#else

typedef  unsigned char* _File_ptr_type;

#endif

inline int   _FILE_fd(const FILE *__f) { return __f->_file; }

inline char* _FILE_I_begin(const FILE *__f) { return (char*) __f->_base; }

inline char* _FILE_I_next(const FILE *__f) { return (char*) __f->_ptr; }  

inline char* _FILE_I_end(const FILE *__f)

  { return (char*) __f->_ptr + __f->_cnt; }

inline ptrdiff_t _FILE_I_avail(const FILE *__f) { return __f->_cnt; }

inline char& _FILE_I_preincr(FILE *__f)

  { --__f->_cnt; return *(char*) (++__f->_ptr); }

inline char& _FILE_I_postincr(FILE *__f)

  { --__f->_cnt; return *(char*) (__f->_ptr++); }

inline char& _FILE_I_predecr(FILE *__f)

  { ++__f->_cnt; return *(char*) (--__f->_ptr); }

inline char& _FILE_I_postdecr(FILE *__f)

  { ++__f->_cnt; return *(char*) (__f->_ptr--); }

inline void  _FILE_I_bump(FILE *__f, int __n)

  { __f->_ptr += __n; __f->_cnt -= __n; }

inline void _FILE_I_set(FILE *__f, char* __begin, char* __next, char* __end) {

  __f->_base = (_File_ptr_type) __begin;

  __f->_ptr  = (_File_ptr_type) __next;

  __f->_cnt  = __end - __next;

}

# define _STLP_FILE_I_O_IDENTICAL 1

#elif defined(__EMX__)

inline int   _FILE_fd(const FILE* __f) { return __f->_handle; }

inline char* _FILE_I_begin(const FILE* __f) { return (char*) __f->_buffer; }

inline char* _FILE_I_next(const FILE* __f) { return (char*) __f->_ptr; }

inline char* _FILE_I_end(const FILE* __f) { return (char *) __f->_ptr + __f->_rcount; }

inline ptrdiff_t _FILE_I_avail(const FILE* __f) { return __f->_rcount; }

inline char& _FILE_I_preincr(FILE* __f) { --__f->_rcount; return *(char*) (++__f->_ptr); }

inline char& _FILE_I_postincr(FILE* __f) { --__f->_rcount; return *(char*) (__f->_ptr++); }

inline char& _FILE_I_predecr(FILE* __f) { ++__f->_rcount; return *(char*) (--__f->_ptr); }

inline char& _FILE_I_postdecr(FILE* __f) { ++__f->_rcount; return *(char*) (__f->_ptr--); }

inline void  _FILE_I_bump(FILE* __f, int __n) { __f->_ptr += __n; __f->_rcount -= __n; }

inline void _FILE_I_set(FILE* __f, char* __begin, char* __next, char* __end) {

  __f->_buffer = __begin;

  __f->_ptr  = __next;

  __f->_rcount  = __end - __next;

}

inline char* _FILE_O_begin(const FILE* __f) { return (char*) __f->_buffer; }

inline char* _FILE_O_next(const FILE* __f) { return (char*) __f->_ptr; }

inline char* _FILE_O_end(const FILE* __f) { return (char*) __f->_ptr + __f->_wcount; }

inline ptrdiff_t _FILE_O_avail(const FILE* __f) { return __f->_wcount; }

inline char& _FILE_O_preincr(FILE* __f) { --__f->_wcount; return *(char*) (++__f->_ptr); }

inline char& _FILE_O_postincr(FILE* __f) { --__f->_wcount; return *(char*) (__f->_ptr++); }

inline char& _FILE_O_predecr(FILE* __f) { ++__f->_wcount; return *(char*) (--__f->_ptr); }

inline char& _FILE_O_postdecr(FILE* __f) { ++__f->_wcount; return *(char*) (__f->_ptr--); }

inline void _FILE_O_bump(FILE* __f, int __n) { __f->_ptr += __n; __f->_wcount -= __n; }

inline void _FILE_O_set(FILE* __f, char* __begin, char* __next, char* __end) {

  __f->_buffer = __begin;

  __f->_ptr  = __next;

  __f->_wcount  = __end - __next;

}

# undef _STLP_FILE_I_O_IDENTICAL

# elif defined(_STLP_SCO_OPENSERVER) || defined(__NCR_SVR)

typedef  unsigned char* _File_ptr_type;

inline int   _FILE_fd(const FILE *__f) { return __f->__file; }

inline char* _FILE_I_begin(const FILE *__f) { return (char*) __f->__base; }

inline char* _FILE_I_next(const FILE *__f) { return (char*) __f->__ptr; }

inline char* _FILE_I_end(const FILE *__f)

  { return (char*) __f->__ptr + __f->__cnt; }

inline ptrdiff_t _FILE_I_avail(const FILE *__f) { return __f->__cnt; }

inline char& _FILE_I_preincr(FILE *__f)

  { --__f->__cnt; return *(char*) (++__f->__ptr); }

inline char& _FILE_I_postincr(FILE *__f)

  { --__f->__cnt; return *(char*) (__f->__ptr++); }

inline char& _FILE_I_predecr(FILE *__f)

  { ++__f->__cnt; return *(char*) (--__f->__ptr); }

inline char& _FILE_I_postdecr(FILE *__f)

  { ++__f->__cnt; return *(char*) (__f->__ptr--); }

inline void  _FILE_I_bump(FILE *__f, int __n)

  { __f->__ptr += __n; __f->__cnt -= __n; }

inline void _FILE_I_set(FILE *__f, char* __begin, char* __next, char* __end) {

  __f->__base = (_File_ptr_type) __begin;

  __f->__ptr  = (_File_ptr_type) __next;

  __f->__cnt  = __end - __next;

}

# define _STLP_FILE_I_O_IDENTICAL 1

# elif defined(__sun) && defined( _LP64)

typedef long _File_ptr_type;

inline int _FILE_fd(const FILE *__f) { return (int) __f->__pad[2]; }

inline char* _FILE_I_begin(const FILE *__f) { return (char*)

__f->__pad[1]; }

inline char* _FILE_I_next(const FILE *__f) { return (char*)

__f->__pad[0]; }

inline char* _FILE_I_end(const FILE *__f)

{ return (char*) __f->__pad[0] + __f->__pad[3]; }

inline ptrdiff_t _FILE_I_avail(const FILE *__f) { return __f->__pad[3]; }

inline char& _FILE_I_preincr(FILE *__f)

{ --__f->__pad[3]; return *(char*) (++__f->__pad[0]); }

inline char& _FILE_I_postincr(FILE *__f)

{ --__f->__pad[3]; return *(char*) (__f->__pad[0]++); }

inline char& _FILE_I_predecr(FILE *__f)

{ ++__f->__pad[3]; return *(char*) (--__f->__pad[0]); }

inline char& _FILE_I_postdecr(FILE *__f)

{ ++__f->__pad[3]; return *(char*) (__f->__pad[0]--); }

inline void _FILE_I_bump(FILE *__f, long __n)

{ __f->__pad[0] += __n; __f->__pad[3] -= __n; }

inline void _FILE_I_set(FILE *__f, char* __begin, char* __next, char*

__end) {

__f->__pad[1] = (_File_ptr_type) __begin;

__f->__pad[0] = (_File_ptr_type) __next;

__f->__pad[3] = __end - __next;

}

# define _STLP_FILE_I_O_IDENTICAL

#elif defined (__CYGWIN__) || defined(__FreeBSD__)  || defined(__NetBSD__) \

  || defined(__amigaos__) || ( defined(__GNUC__) && defined(__APPLE__) ) || defined (_STLP_VXWORKS_TORNADO) \

  || defined (__SYMBIAN32__)

inline int _FILE_fd(const FILE *__f) { return __f->_file; }

inline char* _FILE_I_begin(const FILE *__f) { return (char*)

						__f->_bf._base; }

inline char* _FILE_I_next(const FILE *__f) { return (char*) __f->_p; } 

inline char* _FILE_I_end(const FILE *__f)

{ return (char*) __f->_p + __f->_r; }

inline ptrdiff_t _FILE_I_avail(const FILE *__f) { return __f->_r; }

inline char& _FILE_I_preincr(FILE *__f)

{ --__f->_r; --__f->_bf._size; return *(char*) (++__f->_p); }

inline char& _FILE_I_postincr(FILE *__f)

{ --__f->_r; --__f->_bf._size; return *(char*) (__f->_p++); }

inline char& _FILE_I_predecr(FILE *__f)

{ ++__f->_r; ++ __f->_bf._size; return *(char*) (--__f->_p); }

inline char& _FILE_I_postdecr(FILE *__f)

{ ++__f->_r; ++__f->_bf._size; return *(char*) (__f->_p--); }

inline void _FILE_I_bump(FILE *__f, int __n)

{ __f->_p += __n; __f->_bf._size+=__n; __f->_r -= __n; }

inline void _FILE_I_set(FILE *__f, char* __begin, char* __next, char*

			__end) {

  __f->_bf._base = (unsigned char*) __begin;

  __f->_p = (unsigned char*) __next;

  __f->_r = __f->_bf._size = __end - __next;

}

inline char* _FILE_O_begin(const FILE *__f) { return (char*)

						__f->_bf._base; }

inline char* _FILE_O_next(const FILE *__f) { return (char*) __f->_p; } 

inline char* _FILE_O_end(const FILE *__f)

{ return (char*) __f->_p + __f->_w; }

inline ptrdiff_t _FILE_O_avail(const FILE *__f) { return __f->_w; }

inline char& _FILE_O_preincr(FILE *__f)

{ --__f->_w; --__f->_bf._size; return *(char*) (++__f->_p); }

inline char& _FILE_O_postincr(FILE *__f)

{ --__f->_w; --__f->_bf._size; return *(char*) (__f->_p++); }

inline char& _FILE_O_predecr(FILE *__f)

{ ++__f->_w; ++__f->_bf._size; return *(char*) (--__f->_p); }

inline char& _FILE_O_postdecr(FILE *__f)

{ ++__f->_w; ++__f->_bf._size; return *(char*) (__f->_p--); }

inline void _FILE_O_bump(FILE *__f, int __n)

{ __f->_p += __n; __f->_bf._size+=__n; __f->_w -= __n; }

inline void _FILE_O_set(FILE *__f, char* __begin, char* __next, char*

			__end) {

  __f->_bf._base = (unsigned char*) __begin;

  __f->_p = (unsigned char*) __next;

  __f->_w = __f->_bf._size = __end - __next;

}

# undef _STLP_FILE_I_O_IDENTICAL

#elif defined(_STLP_USE_GLIBC)

inline int   _FILE_fd(const FILE *__f) { return __f->_fileno; }

inline char* _FILE_I_begin(const FILE *__f) { return __f->_IO_read_base; }

inline char* _FILE_I_next(const FILE *__f)  { return __f->_IO_read_ptr; }

inline char* _FILE_I_end(const FILE *__f)   { return __f->_IO_read_end; }

inline ptrdiff_t _FILE_I_avail(const FILE *__f) 

  { return __f->_IO_read_end - __f->_IO_read_ptr; }

inline char& _FILE_I_preincr(FILE *__f)  { return *++__f->_IO_read_ptr; }

inline char& _FILE_I_postincr(FILE *__f) { return *__f->_IO_read_ptr++; }

inline char& _FILE_I_predecr(FILE *__f)  { return *--__f->_IO_read_ptr; }

inline char& _FILE_I_postdecr(FILE *__f) { return *__f->_IO_read_ptr--; }

inline void  _FILE_I_bump(FILE *__f, int __n) { __f->_IO_read_ptr += __n; }

inline void _FILE_I_set(FILE *__f, char* __begin, char* __next, char* __end) {

  __f->_IO_read_base = __begin; 

  __f->_IO_read_ptr  = __next; 

  __f->_IO_read_end  = __end; 

}

inline char* _FILE_O_begin(const FILE *__f) { return __f->_IO_write_base; }

inline char* _FILE_O_next(const FILE *__f)  { return __f->_IO_write_ptr; }

inline char* _FILE_O_end(const FILE *__f)   { return __f->_IO_write_end; }

inline ptrdiff_t _FILE_O_avail(const FILE *__f) 

  { return __f->_IO_write_end - __f->_IO_write_ptr; }

inline char& _FILE_O_preincr(FILE *__f)  { return *++__f->_IO_write_ptr; }

inline char& _FILE_O_postincr(FILE *__f) { return *__f->_IO_write_ptr++; }

inline char& _FILE_O_predecr(FILE *__f)  { return *--__f->_IO_write_ptr; }

inline char& _FILE_O_postdecr(FILE *__f) { return *__f->_IO_write_ptr--; }

inline void  _FILE_O_bump(FILE *__f, int __n) { __f->_IO_write_ptr += __n; }

inline void _FILE_O_set(FILE *__f, char* __begin, char* __next, char* __end) {

  __f->_IO_write_base = __begin; 

  __f->_IO_write_ptr  = __next; 

  __f->_IO_write_end  = __end; 

}

#elif defined(__hpux) /* && defined(__hppa) && defined(__HP_aCC)) */

#ifndef _INCLUDE_HPUX_SOURCE

extern "C" unsigned char *__bufendtab[];

#  undef  _bufend

#  define _bufend(__p) \

     (*(((__p)->__flag & _IOEXT)  ? &(((_FILEX *)(__p))->__bufendp)      \

 				    : &(__bufendtab[(__p) - __iob])))

#  define _bufsiz(__p)  (_bufend(__p) - (__p)->__base)

#endif /* _INCLUDE_HPUX_SOURCE */

#if defined(_STLP_HPACC_BROKEN_BUFEND)

#  undef  _bufend

#  define _bufend(__p) \

     (*(((__p)->__flag & _IOEXT)  ? &((__REINTERPRET_CAST(_FILEX*,(__p)))->__bufendp)  \

                               : &(__bufendtab[__REINTERPRET_CAST(FILE*,(__p)) - __iob])))

#endif

inline int   _FILE_fd(const FILE *__f) { return fileno(__CONST_CAST(FILE *,__f)); }

inline char* _FILE_I_begin(const FILE *__f) { return (__REINTERPRET_CAST(char*, __f->__base)); }

inline char* _FILE_I_next(const FILE *__f)  { return (__REINTERPRET_CAST(char*, __f->__ptr)); }

inline char* _FILE_I_end(const FILE *__f)   { return (__REINTERPRET_CAST(char*, __f->__ptr +__f->__cnt)); }

inline ptrdiff_t _FILE_I_avail(const FILE *__f)  { return __f->__cnt; }

inline char& _FILE_I_preincr(FILE *__f)  { --__f->__cnt; return *__REINTERPRET_CAST(char*, ++__f->__ptr); }

inline char& _FILE_I_postincr(FILE *__f) { --__f->__cnt; return *__REINTERPRET_CAST(char*, __f->__ptr++); }

inline char& _FILE_I_predecr(FILE *__f)  { ++__f->__cnt; return *__REINTERPRET_CAST(char*,--__f->__ptr); }

inline char& _FILE_I_postdecr(FILE *__f) { ++__f->__cnt; return *__REINTERPRET_CAST(char*,__f->__ptr--); }

inline void  _FILE_I_bump(FILE *__f, int __n) { __f->__cnt -= __n; __f->__ptr += __n; }

inline void _FILE_I_set(FILE *__f, char* __begin, char* __next, char* __end) {

# if defined(__hpux)

   if( (unsigned long) (__f - &__iob[0]) > _NFILE)

        __f->__flag |= _IOEXT;  // used by stdio's _bufend macro and goodness knows what else...

# endif

  __f->__cnt  = __end - __next; 

  __f->__base = __REINTERPRET_CAST(unsigned char*, __begin); 

  __f->__ptr  = __REINTERPRET_CAST(unsigned char*, __next);

  _bufend(__f) = __REINTERPRET_CAST(unsigned char*, __end); 

}

// For HPUX stdio, input and output FILE manipulation is identical.

# define _STLP_FILE_I_O_IDENTICAL

#elif defined (__BORLANDC__)

typedef unsigned char* _File_ptr_type;

inline int _FILE_fd(const FILE *__f) { return __f->fd; }

inline char* _FILE_I_begin(const FILE *__f) { return (char*) __f->buffer;

}

inline char* _FILE_I_next(const FILE *__f) 

{ return (char*)__f->curp; } 

inline char* _FILE_I_end(const FILE *__f)

{ return (char*) __f->curp + __f->level; }

inline ptrdiff_t _FILE_I_avail(const FILE *__f) { return __f->level; }

inline char& _FILE_I_preincr(FILE *__f)

{ --__f->level; return *(char*) (++__f->curp); }

inline char& _FILE_I_postincr(FILE *__f)

{ --__f->level; return *(char*) (__f->curp++); }

inline char& _FILE_I_predecr(FILE *__f)

{ ++__f->level; return *(char*) (--__f->curp); }

inline char& _FILE_I_postdecr(FILE *__f)

{ ++__f->level; return *(char*) (__f->curp--); }

inline void _FILE_I_bump(FILE *__f, int __n)

{ __f->curp += __n; __f->level -= __n; }

inline void _FILE_I_set(FILE *__f, char* __begin, char* __next, char*

			__end) {

  __f->buffer = (_File_ptr_type) __begin;

  __f->curp = (_File_ptr_type) __next;

  __f->level = __end - __next;

}

# define _STLP_FILE_I_O_IDENTICAL

#elif defined( __MWERKS__ )

// using MWERKS-specific defines here to detect other OS targets

// dwa: I'm not sure they provide fileno for all OS's, but this should

// work for Win32 and WinCE

# if __dest_os == __mac_os

inline int   _FILE_fd(const FILE *__f) { return ::fileno(__CONST_CAST(FILE*, __f)); }

# else

inline int   _FILE_fd(const FILE *__f) { return ::_fileno(__CONST_CAST(FILE*, __f)); }

# endif

//       Returns a pointer to the beginning of the buffer.

inline char* _FILE_I_begin(const FILE *__f) { return __REINTERPRET_CAST(char*, __f->buffer); }

//       Returns the current read/write position within the buffer.

inline char* _FILE_I_next(const FILE *__f) { return __REINTERPRET_CAST(char*, __f->buffer_ptr); }

//       Returns a pointer immediately past the end of the buffer.

inline char* _FILE_I_end(const FILE *__f) { return __REINTERPRET_CAST(char*, __f->buffer_ptr + __f->buffer_len); }

//       Returns the number of characters remaining in the buffer, i.e.

//       _FILE_[IO]_end(__f) - _FILE_[IO]_next(__f).

inline ptrdiff_t _FILE_I_avail(const FILE *__f) { return __f->buffer_len; }

//       Increments the current read/write position by 1, returning the 

//       character at the old position.

inline char& _FILE_I_preincr(FILE *__f)

  { --__f->buffer_len; return *(char*) (++__f->buffer_ptr); }

inline char& _FILE_I_postincr(FILE *__f)

  { --__f->buffer_len; return *(char*) (__f->buffer_ptr++); }

inline char& _FILE_I_predecr(FILE *__f)

  { ++__f->buffer_len; return *(char*) (--__f->buffer_ptr); }

inline char& _FILE_I_postdecr(FILE *__f)

  { ++__f->buffer_len; return *(char*) (__f->buffer_ptr--); }

inline void  _FILE_I_bump(FILE *__f, int __n)

  { __f->buffer_ptr += __n; __f->buffer_len -= __n; }

inline void _FILE_I_set(FILE *__f, char* __begin, char* __next, char* __end) {

  __f->buffer = __REINTERPRET_CAST(unsigned char*, __begin);

  __f->buffer_ptr   = __REINTERPRET_CAST(unsigned char*, __next);

  __f->buffer_len  = __end - __next;

  __f->buffer_size = __end - __begin;

}

# define _STLP_FILE_I_O_IDENTICAL

#elif defined(__DMC__)

inline int   _FILE_fd(const FILE *__f) { return __f->_file; }

//       Returns a pointer to the beginning of the buffer.

inline char* _FILE_I_begin(const FILE *__f) { return __f->_base; }

//       Returns the current read/write position within the buffer.

inline char* _FILE_I_next(const FILE *__f) { return __f->_ptr; }

//       Returns a pointer immediately past the end of the buffer.

inline char* _FILE_I_end(const FILE *__f) { return __f->_ptr + __f->_cnt; }

//       Returns the number of characters remaining in the buffer, i.e.

//       _FILE_[IO]_end(__f) - _FILE_[IO]_next(__f).

inline ptrdiff_t _FILE_I_avail(const FILE *__f) { return __f->_cnt; }

//       Increments the current read/write position by 1, returning the 

//       character at the NEW position.

inline char& _FILE_I_preincr(FILE *__f) { --__f->_cnt; return *(++__f->_ptr); }

//       Increments the current read/write position by 1, returning the 

//       character at the old position.

inline char& _FILE_I_postincr(FILE *__f) { --__f->_cnt; return *(__f->_ptr++); }

//       Decrements the current read/write position by 1, returning the 

//       character at the NEW position.

inline char& _FILE_I_predecr(FILE *__f) { ++__f->_cnt; return *(--__f->_ptr); }

//       Decrements the current read/write position by 1, returning the 

//       character at the old position.

inline char& _FILE_I_postdecr(FILE *__f) { ++__f->_cnt; return *(__f->_ptr--); }

//       Increments the current read/write position by __n.

inline void _FILE_I_bump(FILE *__f, int __n) { __f->_cnt -= __n; __f->_ptr += __n; }

//       Sets the beginning of the bufer to __begin, the current read/write

//       position to __next, and the buffer's past-the-end pointer to __end.

//       If any of those pointers is null, then all of them must be null.

inline void _FILE_I_set(FILE *__f, char* __begin, char* __next, char* __end)

{