2006-08-25 URLに自動タグ $html =preg_replace("/(ftp:\/\/|http:\/\/|https:\/\/|www|[a-zA-Z0-9-]+\.|[a-zA-Z0-9\.-]+@)(([a-zA-Z0-9-][a-zA-Z0-9-]+\.)+[a-zA-Z0-9-\.\/\_\?\%\#\&\=\;\~\!\(\)]+)/","<a href=\"\\1\\2\">\\1\\2</a>",$txt);