自定义ubb代码,preg_replace()函数的一些代码

function ubb($Text) {
$Text=htmlspecialchars($Text);
$Text=ereg_replace(“rn”,”<br>”,$Text);
$Text=ereg_replace(“r”,”<br>”,$Text);
$Text=nl2br($Text);
$Text=preg_replace(“/\t/is”,”  “,$Text);
$Text=preg_replace(“/[h1](.+?)[/h1]/is”,”<h1>\1</h1>”,$Text);
$Text=preg_replace(“/[h2](.+?)[/h2]/is”,”<h2>\1</h2>”,$Text);
$Text=preg_replace(“/[h3](.+?)[/h3]/is”,”<h3>\1</h3>”,$Text);
$Text=preg_replace(“/[h4](.+?)[/h4]/is”,”<h4>\1</h4>”,$Text);
$Text=preg_replace(“/[h5](.+?)[/h5]/is”,”<h5>\1</h5>”,$Text);
$Text=preg_replace(“/[h6](.+?)[/h6]/is”,”<h6>\1</h6>”,$Text);

$Text=preg_replace(“/[url](http://.+?)[/url]/is”,”<a href=\1>\1</a>”,$Text);
$Text=preg_replace(“/[url](.+?)[/url]/is”,”<a href=”http://\1″>http://\1</a>”,$Text);
$Text=preg_replace(“/[url=(http://.+?)](.*)[/url]/is”,”<a href=\1>\2</a>”,$Text);
$Text=preg_replace(“/[url=(.+?)](.*)[/url]/is”,”<a href=http://\1>\2</a>”,$Text);

$Text=preg_replace(“/[img](.+?)[/img]/is”,”<img src=\1>”,$Text);
$Text=preg_replace(“/[color=(.+?)](.+?)[/color]/is”,”<font color=\1>\2</font>”,$Text);
$Text=preg_replace(“/[size=(.+?)](.+?)[/size]/is”,”<font size=\1>\2</font>”,$Text);
$Text=preg_replace(“/[sup](.+?)[/sup]/is”,”^\1”,$Text);
$Text=preg_replace(“/[sub](.+?)[/sub]/is”,”_\1”,$Text);
$Text=preg_replace(“/[pre](.+?)[/pre]/is”,”<pre>\1</pre>”,$Text);
$Text=preg_replace(“/[email](.+?)[/email]/is”,”<a href=\1>\1</a>”,$Text);
$Text=preg_replace(“/[i](.+?)[/i]/is”,”<i>\1</i>”,$Text);
$Text=preg_replace(“/[b](.+?)[/b]/is”,”<b>\1</b>”,$Text);
$Text=preg_replace(“/[quote](.+?)[/quote]/is”,”<blockquote><font size=’2′ face=’Courier New’>quote:</font><hr>\1<hr></blockquote>”, $Text);
$Text=preg_replace(“/[code](.+?)[/code]/is”,”<blockquote><font size=’2′ face=’Courier New’>code:</font><hr color=’lightblue’><i>\1</i><hr color=’lightblue’></blockquote>”, $Text);
$Text=preg_replace(“/[sig](.+?)[/sig]/is”,”<div style=’text-align: left; color: darkgreen; margin-left: 5%’><br><br>————————–<br>\1<br>————————–</div>”, $Text);
return $Text;
}
function str($msg){
global $admin;
if(!$admin[html]) $msg=htmlspecialchars($msg);
if($admin[ubb]) $msg=ubb($msg);
$msg=nl2br($msg); #处理message
$msg= str_replace(“n”,””,$msg); #处理message
$msg= str_replace(“r”,””,$msg); #处理message
return $msg;
}
function error($msg){
global $admin;
?>

中的
$Text=preg_replace(“/[h2](.+?)[/h2]/is”,”<h2>\1</h2>”,$Text);

里面的 (“/[h2](.+?)[/h2]/is”,”<h2>\1</h2>”,$text)

/[h2](.+?)[/h2]/is  转化成 <h2>\1</h2>

/[h2](.+?)[/h2]/is  里面的 这些”/(.+?) “之类的符号是怎么看的?是什么意思?
______________________________________________________________________________________________

是转意，本身是特殊符号，如果要作为普通字符就要用来转意，就是说\表示()也是特殊符号，所以要用转意