ruby 正则匹配非站内链接

  def has_href_not_XXX?(content)
    content = content.dup
    loop do
      content.sub!(/href=(['"])([^'"]+)\1/, "")
      if $2.blank?
        return false
      else
        if (!$2[".XXX.com"])
          return true
        end
      end
    end
  end