struct _IO_FILE {

  int _flags;       /* High-order word is _IO_MAGIC; rest is flags. */

#define _IO_file_flags _flags

​

  /* The following pointers correspond to the C++ streambuf protocol. */

  /* Note:  Tk uses the _IO_read_ptr and _IO_read_end fields directly. */

  char* _IO_read_ptr;   /* Current read pointer */

  char* _IO_read_end;   /* End of get area. */

  char* _IO_read_base;  /* Start of putback+get area. */

  char* _IO_write_base; /* Start of put area. */

  char* _IO_write_ptr;  /* Current put pointer. */

  char* _IO_write_end;  /* End of put area. */

  char* _IO_buf_base;   /* Start of reserve area. */

  char* _IO_buf_end;    /* End of reserve area. */

  /* The following fields are used to support backing up and undo. */

  char *_IO_save_base; /* Pointer to start of non-current get area. */

  char *_IO_backup_base;  /* Pointer to first valid character of backup area */

  char *_IO_save_end; /* Pointer to end of non-current get area. */

​

  struct _IO_marker *_markers;

​

  struct _IO_FILE *_chain;

​

  int _fileno;

#if 0

  int _blksize;

#else

  int _flags2;

#endif

  _IO_off_t _old_offset; /* This used to be _offset but it's too small.  */

​

#define __HAVE_COLUMN /* temporary */

  /* 1+column number of pbase(); 0 is unknown. */

  unsigned short _cur_column;

  signed char _vtable_offset;

  char _shortbuf[1];

​

  /*  char* _save_gptr;  char* _save_egptr; */

​

  _IO_lock_t *_lock;

#ifdef _IO_USE_OLD_IO_FILE

};

​

struct _IO_FILE_complete

{

  struct _IO_FILE _file;

#endif

#if defined _G_IO_IO_FILE_VERSION && _G_IO_IO_FILE_VERSION == 0x20001

  _IO_off64_t _offset;

# if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T

  /* Wide character stream stuff.  */

  struct _IO_codecvt *_codecvt;

  struct _IO_wide_data *_wide_data;

  struct _IO_FILE *_freeres_list;

  void *_freeres_buf;

  size_t _freeres_size;

# else

  void *__pad1;

  void *__pad2;

  void *__pad3;

  void *__pad4;

  size_t __pad5;

# endif

  int _mode;

  /* Make sure we don't get into trouble again.  */

  char _unused2[15 * sizeof (int) - 4 * sizeof (void *) - sizeof (size_t)];

#endif

};