/*
This product contains certain software code or other information
("AT&T Software") proprietary to AT&T Corp. ("AT&T").  The AT&T
Software is provided to you "AS IS".  YOU ASSUME TOTAL RESPONSIBILITY
AND RISK FOR USE OF THE AT&T SOFTWARE.  AT&T DOES NOT MAKE, AND
EXPRESSLY DISCLAIMS, ANY EXPRESS OR IMPLIED WARRANTIES OF ANY KIND
WHATSOEVER, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, WARRANTIES OF
TITLE OR NON-INFRINGEMENT OF ANY INTELLECTUAL PROPERTY RIGHTS, ANY
WARRANTIES ARISING BY USAGE OF TRADE, COURSE OF DEALING OR COURSE OF
PERFORMANCE, OR ANY WARRANTY THAT THE AT&T SOFTWARE IS "ERROR FREE" OR
WILL MEET YOUR REQUIREMENTS.

Unless you accept a license to use the AT&T Software, you shall not
reverse compile, disassemble or otherwise reverse engineer this
product to ascertain the source code for any AT&T Software.

(c) AT&T Corp. All rights reserved.  AT&T is a registered trademark of AT&T Corp.

***********************************************************************

History:

      24/11/99  - initial release by Hartmut Liefke, liefke@seas.upenn.edu
                                     Dan Suciu,      suciu@research.att.com
*/

//**************************************************************************
//**************************************************************************

// This module contains the main functions for reading a file

#pragma once

#include <stdio.h>
#include <stdlib.h>

#include "Error.hpp"


class CFile
{
   FILE  *file;         // The file handle
   char  *savefilename; // We save the file name

protected:
   unsigned filepos;    // Current file position
   char     iseof;      // Did we reach the end of the file?


public:
   CFile();
  
	/* extra method because Input no longer is a subclass */
	char IsEof();

   virtual char OpenFile(char *filename);
      // Opens a file (if filename==NULL, then the standard input is opened)
      // Returns 1, if okay, otherwise 0

   unsigned GetFilePos();
      // Returns the current position in the file

   virtual unsigned ReadBlock(char *dest,unsigned bytecount);
      // Reads a data block into the memory at 'dest'. The maximum size is 'bytecount'
      // The function returns the number of bytes read or -1, if something fails
      // If the result is smaller than bytecount, the end of the file has been reached
      // and flag eof is set to 1.

   virtual void CloseFile();
      // Closes the file
};