PriceFile* initialize_price_file(char *price_file_name, int file_mode)
{
	PriceFile *price_file;
	FILE *dos_file_stream;
	ItemRecord **temp_cache_ptr;
	ItemRecord *temp_cache_data;
	unsigned i;
	ItemRecord dummy_record;
	unsigned *temp_record_number_ptr;

	price_file = (PriceFile *) malloc(sizeof(PriceFile));

	dos_file_stream = fopen(price_file_name,"r+b");
	if (dos_file_stream == NULL)
		dos_file_stream = fopen(price_file_name,"w+b");
	if (dos_file_stream == NULL)
		{
		printf("Can't open price file %s.\n",price_file_name);
		exit(1);
		}

	price_file->dos_file_stream = dos_file_stream;

	temp_cache_ptr = (ItemRecord **)calloc(CACHE_SIZE, sizeof(ItemRecord *));
	temp_cache_data = (ItemRecord *)calloc(CACHE_SIZE, sizeof(ItemRecord));

	memset(&dummy_record,0,sizeof(ItemRecord));
	dummy_record.upc[0] = (unsigned char)INVALID_BCD_VALUE;

	for (i = 0; i < CACHE_SIZE; i ++)
		{
		temp_cache_ptr[i] = temp_cache_data ++;
		*(temp_cache_ptr[i]) = dummy_record;
		}

	price_file->item_cache = temp_cache_ptr;

	temp_record_number_ptr = (unsigned *)calloc(CACHE_SIZE, sizeof(unsigned));

	for (i = 0; i < CACHE_SIZE; i ++)
		temp_record_number_ptr[i] = INVALID_RECORD_NUMBER;

	price_file->file_record_number = temp_record_number_ptr;

	if (file_mode == CLEAR_FILE)
		{
		for (i = 0; i < FILE_SIZE; i ++)
			{
			position_record(price_file,i);
			fwrite(&dummy_record,1,sizeof(ItemRecord),dos_file_stream);
			}
		}
		
	return(price_file);
}