The IOCTL_DISK_GET_PARTITION_INFO DeviceIoControl operation returns information about the type, size, and nature of a disk partition.
BOOL DeviceIoControl(
(HANDLE) hDevice, // handle to device of interest
IOCTL_DISK_GET_PARTITION_INFO, // 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 output buffer
(DWORD) nOutBufferSize, // size, in bytes, of lpOutBuffer
(LPDWORD) lpBytesReturned, // pointer to variable to receive
// output byte count
(LPOVERLAPPED) lpOverlapped // pointer to 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 the FILE_FLAG_OVERLAPPED flag 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 until an error occurs.
If the operation succeeds, DeviceIoControl returns a nonzero value.
If the operation fails, DeviceIoControl returns zero. To get extended error information, call GetLastError.
This device I/O control operation is for disk devices. Floppy disk drivers, however, do not need to handle this operation.
Windows NT: Requires version 3.1 or later.
Windows: Unsupported.
Windows CE: Unsupported.
Header: Declared in winioctl.h.
Device Input and Output Overview, Device Input and Output Operations, DeviceIoControl, IOCTL_DISK_SET_PARTITION_INFO, PARTITION_INFORMATION