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DeviceIoControl.md

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Function name : DeviceIoControl

Group: Device Input and Output - Library: kernel32

Sends a control code directly to a specified device driver, causing the corresponding device to perform the corresponding operation.

Code examples:

Obtaining physical parameters for a drive: sectors, clusters, cylinders...

Declaration:

BOOL DeviceIoControl(
  HANDLE hDevice,
  DWORD dwIoControlCode,
  LPVOID lpInBuffer,
  DWORD nInBufferSize,
  LPVOID lpOutBuffer,
  DWORD nOutBufferSize,
  LPDWORD lpBytesReturned,
  LPOVERLAPPED lpOverlapped
);

FoxPro declaration:

DECLARE INTEGER DeviceIoControl IN kernel32;
	INTEGER   hDevice,;
	INTEGER   dwIoControlCode,;
	STRING  @ lpInBuffer,;
	INTEGER   nInBufferSize,;
	STRING  @ lpOutBuffer,;
	INTEGER   nOutBufferSize,;
	INTEGER @ lpBytesReturned,;
	INTEGER   lpOverlapped

Parameters:

hDevice [in] Handle to the device on which the operation is to be performed.

dwIoControlCode [in] Control code for the operation.

lpInBuffer [in] Pointer to the input buffer that contains the data required to perform the operation.

nInBufferSize [in] Size of the input buffer, in bytes.

lpOutBuffer [out] Pointer to the output buffer that is to receive the data returned by the operation.

nOutBufferSize [in] Size of the output buffer, in bytes.

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

lpOverlapped [in] Pointer to an OVERLAPPED structure.

Return value:

If the function succeeds, the return value is nonzero.

Comments:

To retrieve a handle to the device, you must call the CreateFile function with either the name of a device or the name of the driver associated with a device.

To specify a device name, use the following format: \.\DeviceName

Other valid device names:
\.\a:
\.\PhysicalDrive0
\.\PhysicalDrive1
\.\vwin32