🚀 go-pugleaf

"Mike Collins" <its@TheBottomOfThePost> wrote in message 
news:47be215a@newsgroups.borland.com...

> However, I have found that each time the thread starts, and
> opens / writes data for the first time, it deletes some of the
> previous data.

You are using OPEN_ALWAYS when calling CreateFile(), which allows it to open 
an existing file without clearing its contents.  However, after opening the 
file, you are not seeking to the end before then writing new data to it.  So 
when opening an existing file, you end up overwritting the existing data at 
the beginning of the file.

> My code looks like this:

Try this instead:

    void TEventLogThread::WriteEventToLog(TSTR_LOG_ONLY_EVENT 
&p_strEvtLogData)
    {
        if( hEventLog == INVALID_HANDLE_VALUE )
        {
            hEventLog = CreateFile(szEventLogPath.c_str(), GENERIC_WRITE, 
FILE_SHARE_READ, NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_HIDDEN | 
FILE_ATTRIBUTE_SYSTEM, NULL);

            if( hEventLog == INVALID_HANDLE_VALUE )
                return;

            ULARGE_INTEGER li;
            li.QuadPart = 0;

            li.LowPart = SetFilePointer(hEventLog, (LONG)li.LowPart, 
(PLONG)&li.HighPart, FILE_END);
            if( (li.LowPart == 0xFFFFFFFF) && (GetLastError() != 0) )
            {
                CloseHandle(hEventLog);
                hEventLog = INVALID_HANDLE_VALUE:
                return;
            }
        }

        TDateTime dtEvntWhen = SystemTimeToDateTime(p_strEvtLogData.stWhen);

        AnsiString szBuff;
        szBuff.sprintf("%s,%s,%d,%d,%d,%s,%s\r\n",
            FormatDateTime(SHORT_DATE_FORMAT, dtEvntWhen).c_str(),
            FormatDateTime(SHORT_TIME_FORMAT, dtEvntWhen).c_str(),
            p_strEvtLogData.iEventId,
            p_strEvtLogData.iStatusId,
            p_strEvtLogData.iReasonId,
            p_strEvtLogData.cUserSID.c_str(),
            p_strEvtLogData.cObject.c_str());

        DWORD dwWritten;
        WriteFile(hEventLog, szBuff.c_str(), szBuff.Length(), &dwWritten, 
NULL);
    }


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