标签：
Read permission is the ability to search the directory,that is,to look through it to see what files it contains.
Write permission is the ability to creat and remove files in the directory.
Execute permission is the ability to go through a directory when opening or otherwise accessing a contained file or subdirectory.
标签：
原文地址：http://www.cnblogs.com/wangqingsong/p/4535740.html
