C / C++ / MFC

if(FALSE == (bTrue = DeviceIoControl(
	(HANDLE) hFile,			// handle to file or directory
	FSCTL_SET_COMPRESSION,		// dwIoControlCode
	(LPVOID)COMPRESSION_FORMAT_DEFAULT,// input buffer
	sizeof(USHORT),			// size of input buffer
	NULL,				// lpOutBuffer
	0,				// nOutBufferSize
	(LPDWORD) lpBytesReturned,	// number of bytes returned
	NULL				// OVERLAPPED structure
	)))
{
	dwError = GetLastError();
}

HANDLE hFile = NULL;
DWORD dwErr = NULL;
if(INVALID_HANDLE_VALUE == (hFile = CreateFile(
						  myfolder, // path to folder!!
						  GENERIC_READ, 
						  FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
						  NULL,
						  OPEN_EXISTING,
						  FILE_FLAG_BACKUP_SEMANTICS,
						  NULL)))
{
	dwErr = GetLastError();
}

HWND hWnd = GetSafeHwnd();
    LPITEMIDLIST ppidl;
    if(SHGetSpecialFolderLocation(hWnd, CSIDL_DESKTOP, &ppidl) == NOERROR)
    {
        SHChangeNotifyEntry shCNE;
        shCNE.pidl = ppidl;
        shCNE.fRecursive = TRUE;

        // Returns a positive integer registration identifier (ID).
        // Returns zero if out of memory or in response to invalid parameters.
        m_ulSHChangeNotifyRegister = SHChangeNotifyRegister(hWnd,                                            // Hwnd to receive notification
                SHCNE_DISKEVENTS,                                                                    // Event types of interest (sources)
                SHCNE_MEDIAINSERTED|SHCNE_MEDIAREMOVED,                                              // Events of interest - use                                           // SHCNE_ALLEVENTS for all events
                WM_USER_MEDIACHANGED,                                               // Notification message to be sent                                           // upon the event
                1,                                                                   // Number of entries in the pfsne array
                &shCNE);  // Array of SHChangeNotifyEntry structures that                           // contain the notifications. This array should                           // always be set to one when calling SHChnageNotifyRegister
                          // or SHChangeNotifyDeregister will not work properly.
    
        ASSERT(m_ulSHChangeNotifyRegister != 0);    // Shell notification failed
    }
    else
        ASSERT(FALSE);    // Failed to get desktop location

Somethings seem HARD to do, until we know how to do them.
_AnShUmAn_

CPallini wrote:

What about reading OP's replies?

int i = atoi("FF");
printf("%d\n", i);