function ubb($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","<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