php实现过滤UBB代码的类

class day{
   function ubb($text) {      /// ubb代码转换
        //$text=htmlspecialchars($text);
        //$text=ereg_replace("rn","<br>",$text);
        $text=ereg_replace("[br]","<br />",$text);
        $text=nl2br($text);
        $text=stripslashes($text);
        $text=preg_replace("/\t/is"," ",$text);
        $text=preg_replace("/[url](http://.+?)[/url]/is","<a href="\1" target="new"><u>\1</u></a>",$text);
        $text=preg_replace("/[url](.+?)[/url]/is","<a href="http://\1" target="new"><u>\1</u></a>",$text);
        $text=preg_replace("/[url=(http://.+?)](.+?)[/url]/is","<a href="\1" target="new"><u>\2</u></a>",$text);
        $text=preg_replace("/[url=(.+?)](.+?)[/url]/is","<a href="http://\1" target="new"><u>\2</u></a>",$text);
        $text=preg_replace("/[color=(.+?)](.+?)[/color]/is","<font color="\1">\2</font>",$text);
        $text=preg_replace("/[font=(.+?)](.+?)[/font]/is","<font face="\1">\2</font>",$text);
        $text=preg_replace("/[email=(.+?)](.+?)[/email]/is","<a href="mailto:\1"><u>\2</u></a>",$text);
        $text=preg_replace("/[email](.+?)[/email]/is","<a href="mailto:\1"><u>\1</u></a>",$text);
        $text=preg_replace("/[i](.+?)[/i]/is","<i>\1</i>",$text);
        $text=preg_replace("/[u](.+?)[/u]/is","<u>\1</u>",$text);
        $text=preg_replace("/[b](.+?)[/b]/is","<b>\1</b>",$text);
        $text=preg_replace("/[fly](.+?)[/fly]/is","<marquee width="98%" behavior="alternate" scrollamount="3">\1</marquee>",$text);
        $text=preg_replace("/[move](.+?)[/move]/is","<marquee width="98%" scrollamount="3">\1</marquee>",$text);
        $text=preg_replace("/[shadow=([#0-9a-z]{1,10}),([0-9]{1,3}),([0-9]{1,2})](.+?)[/shadow]/is","<table width="*"><tr><td style="filter:shadow(color=\1, direction=\2 ,strength=\3)">\4</td></tr></table>",$text);
        return $text;
  }
}