自動偵測文字URL並轉成Hyperlink

echo preg_replace("/(http:\/\/|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\" target=\"_blank\">\\1\\2</a>",$text);