code: public function serialflush()
      {
          if (!$this->_ckOpened()) {
              return false;
          }
  
          if (fwrite($this->_dHandle, $this->_buffer) !== false) {
              $this->_buffer = "";
  
              return true;
          } else {
              $this->_buffer = "";
              trigger_error("Error while sending message", E_USER_WARNING);
  
              return false;
          }
      }
docs: Flushes the output buffer
  Renamed from flush for osx compat. issues
  
  @return bool