KsPurgeComm
The availability of this function depends on what the device supports.
Discards 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.
Syntax
BOOL KsPurgeComm(
HANDLE hFile,
DWORD dwFlags
);
Parameters
hFile: a handle to the communications resource. The KsCreateComm function returns this handle.
dwFlags: this parameter can be one or more of the following values.
Value | Description |
---|---|
PURGE_RXABORT 0x0002 |
Terminates all outstanding overlapped read operations and returns immediately, even if the read operations have not been completed. |
PURGE_RXCLEAR 0x0008 |
Clears the input buffer (if the device driver has one). |
PURGE_TXABORT 0x0001 |
Terminates all outstanding overlapped write operations and returns immediately, even if the write operations have not been completed. |
PURGE_TXCLEAR 0x0004 |
Clears the output buffer (if the device driver has one). |
Return value
If the function succeeds, it returns TRUE, otherwise FALSE. To get extended error information, call GetLastError.
Remarks
If a thread uses KsPurgeComm 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). Note, however, that FlushFileBuffers is subject to flow control but not to write time-outs, and it will not return until all pending write operations have been transmitted.
Example
N/A
Requirements
RT | Win32 | |
---|---|---|
Minimum supported version | 4.0 | 4.0 |
Header | kscom.h | kscom.h |
Library | KsApi_Rtss.lib | ksapi.h |
See also