[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
);
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.
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.
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.
See the Remarks section of the DeviceIoControl topic for the implications of overlapped I/O on this operation.
Windows NT: Requires version 5.0 or later.
Windows: Unsupported.
Windows CE: Unsupported.
Header: Declared in winioctl.h.
Device Input and Output Overview, Device Input and Output Operations, CreateFile, DeviceIoControl, FSCTL_SET_REPARSE_POINT, FSCTL_DELETE_REPARSE_POINT, REPARSE_DATA_BUFFER