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// This may look like C code, but it is really -*- C++ -*-
/* 
Copyright (C) 1988 Free Software Foundation
    written by Doug Lea (dl@rocky.oswego.edu)

This file is part of GNU CC.

GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY.  No author or distributor
accepts responsibility to anyone for the consequences of using it
or for whether it serves any particular purpose or works at all,
unless he says so in writing.  Refer to the GNU CC General Public
License for full details.

Everyone is granted permission to copy, modify and redistribute
GNU CC, but only under the conditions described in the
GNU CC General Public License.   A copy of this license is
supposed to have been given to you along with GNU CC so you
can know your rights and responsibilities.  It should be in a
file named COPYING.  Among other things, the copyright notice
and this notice must be preserved on all copies.  
*/

#ifndef _File_h 
#pragma once
#define _File_h 1

#include <builtin.h>
#include <stdio.h>
#include <stddef.h>

enum io_mode                    // known unix file IO modes
{
  io_readonly   = 0,            
  io_writeonly  = 1,
  io_readwrite  = 2, 
  io_appendonly = 3,
  io_append     = 4,            // append, plus allow reads
};

enum access_mode                // ways to open a file
{
  a_createonly  = 0,            // create, fail if file exists
  a_create      = 1,            // create if doesn't exist, else truncate
  a_useonly     = 2,            // use (no truncate)  fail if doesn't exist
  a_use         = 3,            // use (no truncate), create if doesn't exist
};

enum state_value                // File states
{ 
  _good         = 0,            // all is well
  _eof          = 1,            // at eof
  _fail         = 2,            // logical or physical IO error
  _bad          = 4             // unopened/corrupted
};


class Filebuf;

class File
{
  friend class  Filebuf;
protected:
  FILE*         fp;              // _iobuf file pointer
  char*         nm;              // file name (dynamically allocated)
  char          rw;              //  1 = read; 2 = write; 3 = readwrite
                                 //  bit 2 (4) means read/write into string
  state_value   state;           // _good/_eof/_fail/_bad
  long          stat;            // last read/write/... return value

  void          initialize();
  void          reinitialize(const char*);
  char         *readline (int chunk_number, char terminator);

public:
                File();
                File(const char* filename, io_mode m, access_mode a);
                File(const char* filename, const char* m);   
                File(int filedesc, io_mode m);
                File(FILE* fileptr);
                File(int sz, char* buf, io_mode m);

                ~File();

// binding, rebinding, unbinding to physical files

  File&         open(const char* filename, io_mode m, access_mode a);
  File&         open(const char* filename, const char* m);
  File&         open(int  filedesc, io_mode m);
  File&         open(FILE* fileptr);

  File&         close();
  File&         remove();

// class variable access

  int           filedesc();
  const char*   name();
  void          setname(const char* newname);
  int           iocount();

                operator FILE*();

  int           rdstate();
  int           eof();
  int           fail();
  int           bad();
  int           good();

// other status queries

  int           readable();
  int           writable();
  int           is_open();

                operator void*();

// error handling

  void          error();
  void          clear(state_value f = _good); // poorly named
  void          set(state_value f); // set corresponding but
  void          unset(state_value f); // clear corresponding bit
  File&         failif(int cond);
  void          check_state();

// character IO

  File&         get(char& c);
  File&         put(char  c);
  File&         unget(char c);
  File&         putback(char c); // a synonym for unget

// char* IO

  File&         put(const char* s);
  File&         get    (char* s, int n, char terminator = '\n');
  File&         getline(char* s, int n, char terminator = '\n');
  File&         gets   (char **s, char terminator = '\n');

// binary IO

  File&         read(void* x, int sz, int n);
  File&         write(void* x, int sz, int n);

// formatted IO

  File&         form(const char* ...);
  File&         scan(const char* ...);

// buffer IO

  File&         flush();
  File&         flush(char ch); // call stdio _flsbuf
  int           fill();         // call stdio _filbuf

// position control

  File&         seek(long pos, int seek_mode=0); // default seek mode=absolute
  long          tell();

// buffer control

  File&         setbuf(int buffer_kind); // legal vals: _IONBF, _IOFBF, _IOLBF
  File&         setbuf(int size, char* buf);
  File&         raw();
};


// error handlers

extern void  verbose_File_error_handler(char*);
extern void  quiet_File_error_handler(char*);
extern void  fatal_File_error_handler(char*);
extern one_arg_error_handler_t File_error_handler;
extern one_arg_error_handler_t set_File_error_handler(one_arg_error_handler_t);

//#ifdef __OPTIMIZE__



inline int File::filedesc()
{ 
  return fileno(fp);
}

inline const char* File::name()
{ 
  return nm; 
}

inline int File::iocount()
{ 
  return stat; 
}

inline File::operator FILE*()
{ 
  return fp; 
}

inline void File::clear(state_value flag = _good)
{ 
  state = flag;
}

inline void File::set(state_value flag)
{ 
  state = state_value(int(state) | int(flag));
}

inline void File::unset(state_value flag)
{ 
  state = state_value(int(state) & ~int(flag));
}

inline int File::readable()
{ 
  if (fp != 0) { if (feof(fp)) set(_eof); if (ferror(fp)) set(_bad);}
  return (state == _good && (rw & 01));
}

inline int File::writable()
{ 
  if (fp != 0 && ferror(fp)) set(_bad);
  return ((int(state) & (int(_fail)|int(_bad))) == 0 && (rw & 02));
}

inline int File::is_open()
{ 
  return (fp != 0);
}


inline File& File::raw()
{ 
  return this->File::setbuf(_IONBF); 
}

inline void File::check_state() // ensure fp & state agree about eof
{
  if (fp != 0)
  {
    if (feof(fp))
      set(_eof);
    else
      unset(_eof);
    if (ferror(fp))
      set(_bad);
  }
}

inline File& File::failif(int cond)
{ 
  if (cond) set(_fail);  return *this; 
}

inline File& File::get(char& c)
{ 
  if (readable())
  {
    int ch = getc(fp);
    c = ch;
    failif (ch == EOF);
  }
  return *this;
}

inline File& File::put(char  c) 
{ 
  return failif (!writable() ||  putc(c, fp) == EOF);
}

inline File& File::unget(char c)
{ 
  return failif(!is_open() || !(rw & 01) || ungetc(c, fp) == EOF);
} 

inline File& File::putback(char c)
{ 
  return failif (!is_open() || !(rw & 01) || ungetc(c, fp) == EOF);
}

inline File& File::read(void* x, int sz, int n)
{ 
  return failif (!readable() || (stat = fread(x, sz, n, fp)) != n);
} 

inline File& File::write(void* x, int sz, int n) 
{ 
  return failif (!writable() || (stat = fwrite(x, sz, n, fp)) != n);
}

inline File& File::flush()
{ 
  return failif(!is_open() || fflush(fp) == EOF);
}

inline File& File::flush(char ch)
{ 
  return failif(!is_open() || _flsbuf(ch, fp) == EOF);
}

inline int File::fill()
{ 
  failif(!is_open() || (stat = _filbuf(fp)) == EOF);
  return stat;
}

inline File& File::seek(long pos, int seek_mode = 0)
{ 
  return failif (!is_open() || fseek(fp, pos, seek_mode) < 0); 
}

inline long File::tell()
{ 
  failif (!is_open() || ((stat = ftell(fp)) < 0));
  return stat;
}

inline int File::rdstate()
{ 
  check_state();  return state; // check_state is necessary in rare but
}                               // possible circumstances

inline File::operator void*()
{ 
  check_state();  return (int(state) & (int(_bad)|int(_fail)))? 0 : this ; 
}

inline int File::eof()
{ 
  check_state(); return state & _eof; 
}

inline int File::fail()
{ 
  check_state(); return state & _fail; 
}

inline int File::bad()
{ 
  check_state(); return state & _bad; 
}

inline int File::good()
{ 
  check_state(); return rdstate() == _good; 
}


//#endif

#endif
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