functionubb($Text){
$Text=htmlspecialchars($Text);
$Text=ereg_replace("\r\n","<br>",$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","<ahref=\\1>\\1</a>",$Text);
$Text=preg_replace("/\[url\](.+?)\[\/url\]/is","<ahref=\"http://\\1\">http://\\1</a>",$Text);
$Text=preg_replace("/\[url=(http:\/\/.+?)\](.*)\[\/url\]/is","<ahref=\\1>\\2</a>",$Text);
$Text=preg_replace("/\[url=(.+?)\](.*)\[\/url\]/is","<ahref=http://\\1>\\2</a>",$Text);

$Text=preg_replace("/\[img\](.+?)\[\/img\]/is","<imgsrc=\\1>",$Text);
$Text=preg_replace("/\[color=(.+?)\](.+?)\[\/color\]/is","<fontcolor=\\1>\\2</font>",$Text);
$Text=preg_replace("/\[size=(.+?)\](.+?)\[\/size\]/is","<fontsize=\\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","<ahref=\\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><fontsize='2'face='CourierNew'>quote:</font><hr>\\1<hr></blockquote>",$Text);
$Text=preg_replace("/\[code\](.+?)\[\/code\]/is","<blockquote><fontsize='2'face='CourierNew'>code:</font><hrcolor='lightblue'><i>\\1</i><hrcolor='lightblue'></blockquote>",$Text);
$Text=preg_replace("/\[sig\](.+?)\[\/sig\]/is","<divstyle='text-align:left;color:darkgreen;margin-left:5%'><br><br>--------------------------<br>\\1<br>--------------------------</div>",$Text);
return$Text;
}
functionstr($msg){
global$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$msg;
}
functionerror($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