论坛更换域名 网页重定向用301转向比较安全

1. <?php 　//落叶人生域名更换跳转代码  
2. $url=$_SERVER['QUERY_STRING'];   
3. if(preg_match("/\/bbs\/?/i",$url))   
4. {   
5. $url=str_ireplace("404;http://www.***.com:80/bbs/","http://bbs.***.com/",$url);   
6. $url=str_ireplace("404;http://www.***.com/bbs/","http://bbs.***.com/",$url);   
7. $url=str_ireplace("404;http://***com:80/bbs/","http://bbs.***.com/",$url);   
8. $url=str_ireplace("404;http://***.com/bbs/","http://bbs.***.com/",$url);   
9. echo "论坛改版，地址更换，请点击下面地址访问该页面：<BR/>";   
10. echo "<a href=".$url.">".$url."</a>";   
11. echo "<script language=\"javascript\">window.location=\"".$url."\"</script>";   
12. }   
13. else  
14. {   
15. echo "<script language=\"javascript\">window.location=\"http:\/\/bbs.***.com\"</script>";   
16. }   
17. ?>   

If you need to change the URL of a page as it is shown in search engine results， we recommended that you

use a server-side 301 redirect. This is the best way to ensure that users and search engines are directed

to the correct page. The 301 status code means that a page has permanently moved to a new location.

301 redirects are particularly useful in the following circumstances：

You‘ve moved your site to a new domain， and you want to make the transition as seamless as possible.

People access your site through several different URLs. If， for example， your home page can be reached in

multiple ways - for instance， http://example.com/home， http://home.example.com， or http://www.example.com

- it’s a good idea to pick one of those URLs as your preferred （canonical） destination， and use 301

redirects to send traffic from the other URLs to your preferred URL. You can also use Webmaster Tools to

set your preferred domain.

You‘re merging two websites and want to make sure that links to outdated URLs are redirected to the

correct pages.