Why can the `ls` command of Ubuntu list the files of a directory with no execution permission set?

Question

Why can the ls command of Ubuntu list the files of a directory with no execution permission set ?

The Test directory has read and write permissions set but no execution permission set. I understand that the x attribute of the directory specify whether the directory can be accessed, and if it is not set then it doesn't matter whether r or w is set (please correct me if I'm wrong).

The cd and cat commands works as expected, i.e. that cannot do their job, since they cannot access the directory.

Answer 1

Edit:

Apologies, after re-reading the original post, I have a better understanding of the question. The files can be listed even though there is no execute permission because you have read permission on the directory. The x bit controls access to the inode, which contains the file metadata such as permissions info. This is why the files can be listed, but no permission data is available.

https://askubuntu.com/questions/83788/accessing-files-in-a-directory-without-x-permission

See also:

https://unix.stackexchange.com/questions/21251/how-do-directory-permissions-in-linux-work

Answer 2

Having +r but not +x on a directory allows reading its contents, but not making it the current directory. Conversely, having +x on a directory but not +r will allow you to make it your current directory but not list it.

In other words, on a directory:

• r: The read bit allows you to read the contents of that directory
• w: The write bit allows you to create, rename and delete files
• x: The execute bit allows you to chdir into that directory