def parse257(resp) # :nodoc:
      if resp[0, 3] != "257"
        raise FTPReplyError, resp
      end
      if resp[3, 2] != ' "'
        return ""
      end
      dirname = ""
      i = 5
      n = resp.length
      while i < n
        c = resp[i, 1]
        i = i + 1
        if c == '"'
          if i > n or resp[i, 1] != '"'
            break
          end
          i = i + 1
        end
        dirname = dirname + c
      end
      return dirname
    end
handler for response code 257
("PATHNAME" created)

Returns host and port.