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