$domain=unserialize($str);
echo $domain[9];//ok.discuz7.com
echo array_search("bbs2.discuz7.com", unserialize($str));//6

重写条件与规则
<VirtualHost *:80>
 DocumentRoot "D:/www/ok"
   ServerName discuz7.com
   ServerAlias *.discuz7.com

 RewriteEngine On
 RewriteCond %{HTTP_HOST} ^([a-zA-Z0-9]+)\.blog\.discuz7\.com$
 RewriteRule ^/?$ /%{HTTP_HOST}
 RewriteRule ^/([a-zA-Z0-9]+)\.blog\.discuz7\.com/?$ /index.php?name=$1
</VirtualHost>

PS：Apache开启重写,在主配置文件中找到
LoadModule rewrite_module modules/mod_rewrite.so
去掉前面的;分号就OK了。