FSCTL_GET_REPARSE_POINT

[This is preliminary documentation and subject to change.]

The FSCTL_GET_REPARSE_POINT operation returns the reparse point data associated with the file or directory identified by the specified handle. To perform this operation, call the DeviceIoControl function with the following parameters.

BOOL DeviceIoControl(
  (HANDLE) hDevice,        // handle to the file or directory
  FSCTL_GET_REPARSE_POINT, // 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 a REPARSE_DATA_BUFFER
                           // structure
  (DWORD) nOutBufferSize,  // size, in bytes, of lpOutBuffer
  (LPDWORD) lpBytesReturned,   // pointer to variable to receive
                           // output byte count
  (LPOVERLAPPED) lpOverlapped  // pointer to an OVERLAPPED structure
                           // for asynchronous operation
);
 

Parameters

hDevice

Handle to the file or directory from which to obtain the reparse point data. Call the CreateFile function to obtain a handle.

dwIoControlCode

Specifies the FSCTL_GET_REPARSE_POINT control code.

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 a REPARSE_DATA_BUFFER buffer that receives the reparse point data.

nOutBufferSize

Size, in bytes, of the output buffer.

lpBytesReturned

Pointer to a DWORD variable that receives the size, in bytes, of output data returned. If the lpOutBuffer buffer is too small, lpBytesReturned 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 retrieve the number of bytes returned by calling the GetOverlappedResult function. If hDevice is associated with an I/O completion port, you can get the number of bytes returned by calling the GetQueuedCompletionStatus function.

lpOverlapped

Pointer to an OVERLAPPED structure.

If hDevice 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 device was opened with FILE_FLAG_OVERLAPPED and lpOverlapped is NULL, the function fails in unpredictable ways.

If hDevice 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 an error occurs.

Return Values

If the operation succeeds, DeviceIoControl returns a nonzero value, and the output buffer pointed to by lpOutBuffer contains a valid REPARSE_DATA_BUFFER structure, or a portion thereof, depending on the value of nOutBufferSize.

If the operation fails, DeviceIoControl returns zero. The contents of the output buffer pointed to by lpOutBuffer are meaningless. For extended error information, call GetLastError.

Remarks

See the Remarks section of the DeviceIoControl topic for the implications of overlapped I/O on this operation.

QuickInfo

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

See Also

Device Input and Output Overview, Device Input and Output Operations, CreateFile, DeviceIoControl, FSCTL_SET_REPARSE_POINT, FSCTL_DELETE_REPARSE_POINT, REPARSE_DATA_BUFFER