
#include "stdafx.h"

#undef UNICODE
#include 

#include 
using namespace std;

int main()
{
	HANDLE h = CreateFile 
	    ("abc.txt", // lpFileName,
		 GENERIC_READ | GENERIC_WRITE, // dwDesiredAccess,
		 0, // dwShareMode,
		 NULL, // lpSecurityAttributes,
		 CREATE_ALWAYS, // dwCreationDisposition,
  	     FILE_ATTRIBUTE_NORMAL, // dwFlagsAndAttributes,
		 NULL // hTemplateFile
	     );

	if (h == INVALID_HANDLE_VALUE)
	{
		DWORD code = GetLastError ();
		cout << "Chyba pri otvirani " << code << endl;

		char * answer = NULL;

		FormatMessage
		(
			FORMAT_MESSAGE_ALLOCATE_BUFFER |
			FORMAT_MESSAGE_FROM_SYSTEM, // DWORD dwFlags
			NULL, // LPCVOID lpSource,
			code, // DWORD dwMessageId,
			0, // DWORD dwLanguageId,
			(LPTSTR)& answer, //  LPTSTR lpBuffer,
			0, // DWORD nSize,
			NULL // va_list* Arguments
		);

		if (answer)
		{
			cout << "Error: " << answer << endl;
			LocalFree(answer);
		}
	}
	else
	{
		cout << "Otevreno" << endl;

		char data [80] = "Nejaky text";
		int n = strlen (data);

		DWORD answer;
		BOOL ok = WriteFile (h, data, n, &answer, NULL);
		if (ok && answer == n)
			cout << "Zapsano" << endl;
		else
			cout << "Chyba pri zapisovani" << endl;

		SetFilePointer(h, 0, NULL, FILE_BEGIN);

		char line[80];
		n = sizeof (line) -  1;
		ok = ReadFile (h, line, n, &answer, NULL);
		if (ok)
		{
			line[answer] = 0;
			cout << "Precteno " << answer << " bytu: " << line << endl;
		}

		if (CloseHandle(h))
   		    cout << "Uzavreno" << endl;
	}

	char c;
	cout << "Napis cokoli a stiskni enter";
	cin >> c;
	
    return 0;
}