get_response

# File lib/net/imap.rb, line 1164
    def get_response
      buff = ""
      while true
        s = @sock.gets(CRLF)
        break unless s
        buff.concat(s)
        if /\{(\d+)\}\r\n/ =~ s
          s = @sock.read($1.to_i)
          buff.concat(s)
        else
          break
        end
      end
      return nil if buff.length == 0
      if @@debug
        $stderr.print(buff.gsub(/^/, "S: "))
      end
      return @parser.parse(buff)
    end