PurgeComm (Windows CE 5.0)

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This function can discard all characters from the output or input buffer of a specified communications resource.

It can also terminate pending read or write operations on the resource.

BOOL PurgeComm(HANDLEhFile,DWORDdwFlags);

Parameters

  • hFile
    [in] Handle to the communications resource.

    The CreateFile function returns this handle.

  • dwFlags
    [in] Specifies the action to take.

    The following are values for this parameter.

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

Return Values

Nonzero indicates success.

Zero indicates failure.

To obtain extended error information, call the GetLastError function.

Remarks

If a thread uses PurgeComm to flush an output buffer, the deleted characters are not transmitted.

To empty the output buffer while ensuring that the contents are transmitted, call the FlushFileBuffers function (a synchronous operation).

FlushFileBuffers is subject to flow control but not to write timeouts, and it does not return until all pending write operations have been transmitted.

Requirements

OS Versions: Windows CE 1.0 and later.
Header: Winbase.h.
Link Library: Serdev.lib.

See Also

CreateFile | FlushFileBuffers

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