http://a.xxx.com http://www.xxx.com/a
http://a.xxx..com/1.html http://www.xxx.com/a/1.html


http://b.xxx.com http://www.xxx.com/b
http://b.xxx..com/1.html http://www.xxx.com/b/1.html

http://c.xxx.com http://www.xxx.com/c
http://c.xxx.com/1.html http://www.xxx.com/c/1.html


想实现如上跳转，求高人指教

#301-START
if ($host ~ '^a.xxx.com'){
return 301 http://www.xxx.com$request_uri;
}
#301-END

该如何写规则呢？在宝塔管理中使用的，
可以有偿~谢谢