SHFileOperation for recursive folder copy

SHCopy.cpp

bool SHCopy(LPCTSTR from, LPCTSTR to)
{
	Log(_T("Recursive file copy from %s to %s"), from, to);

	SHFILEOPSTRUCT fileOp = {0};
	fileOp.wFunc = FO_COPY;
	TCHAR newFrom[MAX_PATH];
	_tcscpy_s(newFrom, from);
	newFrom[_tcsclen(from) + 1] = NULL;
	fileOp.pFrom = newFrom;
	TCHAR newTo[MAX_PATH];
	_tcscpy_s(newTo, to);
	newTo[_tcsclen(to) + 1] = NULL;
	fileOp.pTo = newTo;
	fileOp.fFlags = FOF_SILENT | FOF_NOCONFIRMATION | FOF_NOERRORUI | FOF_NOCONFIRMMKDIR;
	
	int result = SHFileOperation(&fileOp);

	Log(_T("SHFileOperation return code: 0x%x"), result);

	return result == 0;
}

//sample call, E:\ is a USB stick
bool result = SHCopy(_T("E:\\*"), _T("C:\\SomeDirectory\\"));

//when called on XP SP3 and with the flag FOF_SILENT, this fails with 0x4C7 (ERROR_CANCELLED)
//removal of FOF_SILENT makes it work >.<

Worked! Nothing else worked because of double null terminators issues. Don't know why MS used double nulls, but seems like a hack.

https://learn.microsoft.com/en-us/windows/win32/api/shellapi/ns-shellapi-shfileopstructa

Although this member is declared as a single null-terminated string, it is actually a buffer that can hold multiple null-delimited file names. Each file name is terminated by a single NULL character. The last file name is terminated with a double NULL character ("\0\0") to indicate the end of the buffer.