Thread: How many chars does it take to fill up 1 megabyte?

Ugh, is there any other way to make the Secure Disk Cleanse loop faster?

Code:

#include <stdio.h>
#include <fstream>
#include <iostream>
#include <windows.h>
int main()
{
    long end,Oend,begin,Obegin;
	std::string Dir,File,Option;
	int Loop,SizeOfDisk,SizeOfFile,OrigSizeOfFile;
	Loop=1;
	std::cout<<"Welcome to C.J.'s Security 'suite'!\n";
	std::cout<<"Please enter what you want to do.\n";
	std::cout<<"To select Secure Disk Wipe, input SDW.\n";
	std::cout<<"To select Secure Disk Cleanse, input SDC.\n";
	std::cout<<"To select Secure File Deletion, input SFD.\n";
	std::cout<<"To select ---this option is not yet available---.\n";
	std::cout<<"To select ---this option is not yet available---.\n";
	std::cout<<"Option:";
	getline(std::cin,Option,'\n');
	if(Option=="SDW")
	{
		std::cout<<"Sorry,This option is not yet available";
		std::cin.get();
	}
	if(Option=="SDC")
	{
		std::cout<<"Please enter Disk(Ex. C:\\):";
		getline(std::cin,Dir,'\n');
		if(Dir.length()!=3)
		{
			while(Loop==1)
			{
				File="";
				std::cout<<"\nPlease enter Disk:";
				getline(std::cin,Dir,'\n');
				if(Dir.length()==3)
				{
					Loop=0;
				}
			}
			Loop=1;
		}
		File=Dir;
		File="SecureDiskCleanse.txt";
		std::ofstream a_file(File.c_str());
		while(Loop==1)
		{
			typedef BOOL (WINAPI *PGETDISKFREESPACEEX)(LPCSTR,
			PULARGE_INTEGER, PULARGE_INTEGER, PULARGE_INTEGER);
			PGETDISKFREESPACEEX pGetDiskFreeSpaceEx;
			__int64 i64FreeBytesToCaller, i64TotalBytes, i64FreeBytes;
			pGetDiskFreeSpaceEx=(PGETDISKFREESPACEEX)GetProcAddress(
			GetModuleHandle("kernel32.dll"),
							"GetFreeDiskSpaceExA");
			GetDiskFreeSpaceExA(
								Dir.c_str(),
								NULL,
								NULL,
								(PULARGE_INTEGER)&i64FreeBytes);
			a_file<<"Secure Disk Cleanse.";
			SizeOfDisk=i64FreeBytes/1024/1024;
			if(SizeOfDisk<100)
			{
				Loop=0;
			}
		}
		a_file.close();
		File="DEL "+File;
		system(File.c_str());
		std::cin.get();
	}
	if(Option=="SFD")
	{
		std::cout<<"Please enter file path and name.:";
		getline(std::cin,File,'\n');
		std::ifstream OrigSize_file(File);
		Obegin=OrigSize_file.tellg();
		OrigSize_file.seekg(0,std::ios::end);
		Oend=OrigSize_file.tellg();
		OrigSize_file.close();
		OrigSizeOfFile=(Oend-Obegin);
		std::ofstream a_file(File.c_str(), std::ios::trunc);
		while(Loop==1)
		{
		    std::ifstream Size_File(File);
		    begin=Size_File.tellg();
		    Size_File.seekg(0,std::ios::end);
		    end=Size_File.tellg();
		    Size_File.close();
		    SizeOfFile=(end-begin);
			a_file<<"Secure File Deletion.";
			if(SizeOfFile>(OrigSizeOfFile+10))
			{
				Loop=0;
			}
		}
		a_file.close();
		File="DEL "+File;
		system(File.c_str());
		std::cin.get();
	}
	else
	{
		std::cin.get();
	}
	return 0;
}

Originally Posted by bikr692002

How many chars(i.e. A) does it take to fill up 1 megabyte?

Only 1 if you re-use it :-)

>>trying to correct was Ancient Dragons implication that a 64bit system will always have a 64bit char type.


After re-reading my post -- I see it is technically incorrect as you mentioned. The point was that there is no standard number of bits in 1 byte. sizeof(char) will always be 1 regardless of the number of bits.