FSCTL_GET_HFS_INFORMATION

Using the FSCTL_GET_HFS_INFORMATION control code returns Macintosh Finder information about the file associated with the input handle.

To perform this operation, call the DeviceIoControl function with the following parameters.

BOOL DeviceIoControl(
  (HANDLE) hFile,              // handle to file
  FSCTL_GET_HFS_INFORMATION,   // dwIoControlCode operation
  NULL,                        // lpInBuffer; must be NULL
  0,                           // nInBufferSize; must be zero
  (LPVOID) lpOutBuffer,        // output buffer 
  (DWORD) nOutBufferSize,      // size of output buffer
  (LPDWORD) lpBytesReturned,   // number of bytes returned
  (LPOVERLAPPED) lpOverlapped  // OVERLAPPED structure
);

Parameters

hFile

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

dwIoControlCode

[in] Control code for the operation. This value identifies the specific operation to be performed and the type of file on which to perform it. Use FSCTL_GET_HFS_INFORMATION for this operation.

lpInBuffer

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

nInBufferSize

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

lpOutBuffer

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

nOutBufferSize

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

lpBytesReturned

[out] Pointer to a variable that receives the size, in bytes, of output data returned.

If the output buffer is too small to return any data, then the call fails, GetLastError returns the error code ERROR_INSUFFICIENT_BUFFER, and the returned byte count is zero.

If the output buffer is too small to hold all of the data but can hold some entries, then the operating system returns as much as fits, the call fails, GetLastError returns the error code ERROR_MORE_DATA, and lpBytesReturned indicates the amount of data returned. Your application should call DeviceIoControl again with the same operation, specifying a new starting point.

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

[in] Pointer to an OVERLAPPED structure.

If hFile was opened with the FILE_FLAG_OVERLAPPED flag, lpOverlapped must point to a valid OVERLAPPED structure. In this case, the operation 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, lpOverlapped is ignored and DeviceIoControl 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.

Requirements

  Windows NT/2000: Requires Windows 2000.
  Windows 95/98: Unsupported.
  Header: Declared in Winioctl.h.

See Also

Device Input and Output Overview, Device Input and Output Control Codes, CreateFile, DeviceIoControl, GetOverlappedResult, GetQueuedCompletionStatus, HFS_INFORMATION_BUFFER, OVERLAPPED