IOCTL_SERIAL_PURGE (Compact 2013)

3/26/2014

This I/O control message discards characters from the output or input buffer of a specified communications resource. It can also terminate pending read or write operations on the resource. Send this message with DeviceIoControl.

Syntax

BOOL DeviceIoControl(
    HANDLE hDevice,           // handle to the device
    DWORD dwIoControlCode,    // use IOCTL_ IOCTL_SERIAL_PURGE
    LPVOID lpInBuffer,        // pointer to input buffer
    DWORD nInBufferSize,      // input buffer size
    LPVOID lpOutBuffer,       // pointer to output buffer
    DWORD nOutBufferSize,     // output buffer size
    LPDWORD lpBytesReturned,  // number of bytes returned
    OVERLAPPED lpOverlapped   // pointer to OVERLAPPED structure
);

Parameters

• hDevice
  [in] Handle to the device. To obtain a device handle, call COM_Open.

• dwIoControlCode
  [in] Control code for the operation. Use IOCTL_SERIAL_PURGE for this operation.

• lpInBuffer
  [in] Pointer to a DWORD variable containing the action.

  The following table shows the flags that this DWORD variable can contain.

  Flag	Description
  PURGE_TXABORT	Terminates all outstanding write operations and returns immediately, even if the write operations have not been completed.
  PURGE_RXABORT	Terminates all outstanding read operations and returns immediately, even if the read operations have not been completed.
  PURGE_TXCLEAR	Clears the output buffer if the driver has one.
  PURGE_RXCLEAR	Clears the input buffer if the driver has one.

• nInBufferSize
  Set to sizeof(DWORD).

• lpOutBuffer
  Ignored.

• nOutBufferSize
  Ignored.

• lpBytesReturned
  Ignored.

• lpOverlapped
  Ignored.

Return Values

Returns TRUE if successful; otherwise, returns FALSE.

Remarks

To get extended error information, call GetLastError. GetLastError may return other standard error messages as appropriate.

Requirements

Header

pegdser.h

See Also

Reference

Serial Port Driver IOCTLs
COM_IOControl
COM_Open
DeviceIoControl