C++經過CFile寫本地日誌文件

CFile log_file;
    int log_file_opened = 0;
    void logMessage(const char * sMsg)
    {
        if(!log_file_opened)
        {
            log_file.Open("D:\\tex.log", CFile::modeCreate|CFile::modeWrite);
            log_file_opened = 1;
        }
        int len = strlen(sMsg);
        log_file.Write(sMsg, len);
    }