def cmd(name, *params)
      @mutex.synchronize do
        connect unless connected?
        @conn.write "#{name} #{params.join(' ').gsub('\\', '\\\\\\')}\n"
        status, length = conn_gets.split # <status> <content_length>\n
        content = conn_read(length.to_i + 1) # +1 = \n
        content.chomp!
        raise CommandFailed, "Command #{name} returned with status #{status}: #{content}" if status.to_i != 200
        content
      end
    end
def cmd(name, *params)
      @mutex.synchronize do
        connect unless connected?
        @conn.write "#{name} #{params.join(' ').gsub('\\', '\\\\\\')}\n"
        status, length = conn_gets.split # <status> <content_length>\n
        content = conn_read(length.to_i + 1) # +1 = \n
        content.chomp!
        raise CommandFailed, "Command #{name} returned with status #{status}: #{content}" if status.to_i != 200
        content
      end
    end
Sends a command to varnishd.
 Raises a Varnish::CommandFailed error when a non-200 status is returned
 Returns the response text