code: func parseControl(line string, c *control) {
  	toks := strings.SplitN(line, _SPC_, 2)
  	if len(toks) == 1 {
  		c.op = strings.TrimSpace(toks[0])
  		c.args = _EMPTY_
  	} else if len(toks) == 2 {
  		c.op, c.args = strings.TrimSpace(toks[0]), strings.TrimSpace(toks[1])
  	} else {
  		c.op = _EMPTY_
  	}
  }
docs: // Parse a control line from the server.