Read a file with the Win32 API

readfile.cpp

void read_file(char* path, PBYTE buffer, size_t bufsize, DWORD* size_read) {

	HANDLE hFile;

	hFile = CreateFileA(path,               // file to open
		GENERIC_READ,          // open for reading
		FILE_SHARE_READ,       // share for reading
		NULL,                  // default security
		OPEN_EXISTING,         // existing file only
		FILE_ATTRIBUTE_NORMAL, // normal file
		NULL);                 // no attr. template

	if (hFile == INVALID_HANDLE_VALUE) {

		std::cout << "Terminal failure: unable to open file for reading" << std::endl;
		return;
	}

	DWORD file_size = 0;

	file_size = GetFileSize(hFile, NULL);

	if (file_size > bufsize) {
		std::cout << ("Not big enough, abort.\n");
		return;
	}

	DWORD dw_read = 0;
	if (FALSE == ReadFile(hFile, buffer, file_size, &dw_read, NULL))
	{
		std::cout << ("Terminal failure: Unable to read from file.\n GetLastError=%08x\n", GetLastError());
		CloseHandle(hFile);
		return;
	}

	if (dw_read == 0)
	{
		std::cout << ("No data read from file\n");
	}

	*size_read = dw_read;

	CloseHandle(hFile);
}