基础知识

http://bbs.dianbo.org/forum.php?mod=viewthread&tid=5740

http://www.cnblogs.com/hateislove214/archive/2011/03/30/2000030.html

http://blog.chinaunix.net/space.php?uid=287570&do=blog&id=162680

http://blog.chinaunix.net/space.php?uid=287570&do=blog&id=162674