FSCTL_GET_HFS_INFORMATION

[This is preliminary documentation and subject to change.]

The FSCTL_GET_HFS_INFORMATION operation returns Macintosh Finder information about the file associated with the input handle. To perform this operation, call the DeviceIoControl function using the following parameters.

BOOL DeviceIoControl(
  (HANDLE) hFile,             // handle to file of interest
  FSCTL_GET_HFS_INFORMATION,  // dwIoControlCode, control code of
                              // operation to perform
  NULL,                       // lpInBuffer is not used; must be NULL
  0,                          // nInBufferSize is not used;
                              // must be zero
  (LPVOID) lpOutBuffer,       // pointer to buffer to receive
                              // output data
  (DWORD) nOutBufferSize,     // size of output buffer
  (LPDWORD) lpBytesReturned,  // pointer to variable to receive
                              // output byte count
  (LPOVERLAPPED) lpOverlapped      // pointer to OVERLAPPED structure for
                              // asynchronous operation
);

Parameters

hFile

Handle to the file for which HFS information is sought. To obtain a file handle, call the CreateFile function.

dwIoControlCode

Control code for the operation. This value identifies the specific operation to be performed and the type of file on which the operation is to be performed. Use FSCTL_GET_HFS_INFORMATION for this operation.

lpInBuffer

Pointer to the input buffer. Not used; must be NULL.

nInBufferSize

Size, in bytes, of the input buffer. Not used; must be zero.

lpOutBuffer

Pointer to the output buffer, an instance of the HFS_INFORMATION_BUFFER structure.

nOutBufferSize

Size, in bytes, of the output buffer, that is the size of an HFS_INFORMATION_BUFFER structure.

lpBytesReturned

Pointer to a DWORD variable that receives the size, in bytes, of output data returned. If the lpOutBuffer buffer is too small, the lpBytesReturned parameter receives the required buffer size.

If lpOverlapped is NULL (nonoverlapped I/O), lpBytesReturned cannot be NULL.

If lpOverlapped is not NULL (overlapped I/O), lpBytesReturned can be NULL. If this is an overlapped operation, you can get the number of bytes returned by calling the GetOverlappedResult function. If hDevice is associated with an I/O completion port, you can retrieve the number of bytes returned by calling the GetQueuedCompletionStatus function.

lpOverlapped

Pointer to an OVERLAPPED structure.

If hFile was opened with the FILE_FLAG_OVERLAPPED flag, this parameter must point to a valid OVERLAPPED structure. In this case, DeviceIoControl is performed as an overlapped (asynchronous) operation. If the file was opened with the FILE_FLAG_OVERLAPPED flag and lpOverlapped is NULL, the function fails in unpredictable ways.

If hFile was opened without specifying the FILE_FLAG_OVERLAPPED flag, this parameter is ignored and the DeviceIoControl function does not return until the operation has been completed, or until an error occurs.

Return Values

If the operation succeeds, DeviceIoControl returns a nonzero value, and the output buffer pointed to by lpvOutBuffer contains a valid HFS_INFORMATION_BUFFER structure.

If the operation fails, DeviceIoControl returns zero. In this case, the contents of the output buffer pointed to by lpvOutBuffer are meaningless. To get extended error information, call GetLastError.

Remarks

For the implications of overlapped I/O on this operation, see the Remarks section of DeviceIoControl.

QuickInfo

  Windows NT: Requires version 5.0 or later.
  Windows: Unsupported.
  Windows CE: Unsupported.
  Header: Declared in winioctl.h.

See Also

CreateFile, DeviceIoControl, GetOverlappedResult, GetQueuedCompletionStatus, HFS_INFORMATION_BUFFER, OVERLAPPED