file_IO_lib.cpp #2

#include "stdafx.h"
#include "file_io_lib.h"


//------------------------------------------------------------------------------------
//	FindNumberOfDigits
//
//	Description - Finds and returns number of digits in 'in_number' integer
//------------------------------------------------------------------------------------
int	FindNumberOfDigits(int in_number)
{
	int digit_cnt = 0;

	// Simply add 1 digit for every division by 10 that does not result in 0
	while ( in_number != 0 )
	{
		in_number /= 10;
		++digit_cnt;
	}

	return digit_cnt;
}


//------------------------------------------------------------------------------------
//	ExtensionTypeToString
//
//	Description - Converts constant number to appropriate file extension string
//------------------------------------------------------------------------------------
char* ExtensionTypeToString(int file_type)
{	
	char* str;

	if (file_type == INPUT_IS_BMP) str = ".BMP";
	else if (file_type == INPUT_IS_RAW) str = ".RAW";
	else if (file_type == INPUT_IS_BIN) str = ".BIN";
	else if (file_type == INPUT_IS_RAW_STACK) str = ".STACK.RAW";
	else if (file_type == INPUT_IS_BIN_STACK) str = ".STACK.BIN";
	else if (file_type == INPUT_IS_CBIN_STACK) str = ".STACK.CBIN";

	else str = "INVALID";

	return str;
}


//------------------------------------------------------------------------------------
//	DeleteFilesWithIndex
//
//	Description - Deletes all files with prefix 'file_prefix' with an appended
//	index from 'first_index' to 'last_index', and extension number 'file_type'
//------------------------------------------------------------------------------------
bool DeleteFilesWithIndex(char* file_prefix, int file_type, int first_index, int last_index)
{
	char * file_name;
	int	max_digits = FindNumberOfDigits( last_index );

	// Loop for each index, creating file name and deleting file
	for (int i = first_index; i <= last_index; i++)
	{
		file_name = AppendDigitsAndExtension(file_prefix, i, max_digits, file_type);

		// Delete the file
		if ( !DeleteFile( file_name ) )
			return false;

		free( file_name );
	}

	return	true;
}


//------------------------------------------------------------------------------------
//	DeleteFilesWithIndex
//
//	Description - Deletes all files with prefix 'file_prefix' with an appended
//	index from 'first_index' to 'last_index', and extension number 'file_type'
//------------------------------------------------------------------------------------
char* AppendDigitsAndExtension(char* file_prefix, int num, int max_dig_cnt, int ext)
{
	char* file_name = (char*) malloc(sizeof(char)*512);	
	
	// Pad with '0's if needed
	sprintf(file_name, "%s", file_prefix);
	for ( int cur_dig = FindNumberOfDigits(num); cur_dig < max_dig_cnt; cur_dig++ )
	{
		sprintf(file_name, "%s0", file_name);
	}

	// There should only be a BMP, BIN, or RAW extension
	if (ext == INPUT_IS_BMP)
		sprintf(file_name, "%s%d.bmp", file_name, num);
	else if (ext == INPUT_IS_RAW)
		sprintf(file_name, "%s%d.raw", file_name, num);
	else if (ext == INPUT_IS_BIN)
		sprintf(file_name, "%s%d.bin", file_name, num);

	return file_name;
}


//------------------------------------------------------------------------------------
//	OpenFileForAppendAtLine
//
//	Description - Opens file 'file_name', and writes '\n' until 'line_number' is
//	total number of lines in the file, and returns a pointer to the file.
//------------------------------------------------------------------------------------
int	OpenFileForAppendAtLine( int line_number, char *file_name, ofstream &res_file )
{
	ifstream file_in;
	char	buffer[512];

	file_in.open( file_name, ios::in );

	// Make sure file is open
	if( !file_in.is_open() )
	{
		return	1;
	}

	// Figure out how many lines there are by counting '\n' characters
	int		line_cnt = 0;
	do
	{
		file_in.getline( buffer, 512 );
		++line_cnt;
	} while ( !file_in.eof() );

	// Now we know how many lines there currently are, reopen the file
	// in append mode, write out however many lines are remining and return
	file_in.close();

	res_file.open( file_name, ios::out | ios::app );

	while ( (++line_cnt) <= line_number )
	{
		res_file << endl;
	}
	
	return	0;
}