Lowest permission level to see the content of a file?

Question

How can I see the contents of a file with 111 permissions? A thing called Y-combinator, as an input, prints the content of a file. My instinct says that you can run it with 100 permissions. However, I know only the theory, not the practise.

Which is the lowest permission level to see a file with Y-combinator in Bash?

The user nobody_ comments:

You don't make any sense. The Y combinator is used to create recursive functions and has nothing to do with permissions.

A question arises:

Which is the lowest permission level to see a file in Bash?

Answer 1

To execute a file (script or otherwise), you need to be able to load its content into memory, hence to have read access.

So only leaving execution rights on your files is not going to allow anybody to read it. However, this is still a bad idea. Nothing that should not be executed should receive execution rights. In your position, I would be much more worried in accidentally executing a text file that begins with rm * than somebody using tricks to peek at my files.

Answer 2

I think you can't, and even the interpreter won't be able to (and therefore won't run it).

However, you shouldn't be worried about people seeing your code; if there are eg. security flaws, you should fix them instead.

Answer 3

You can't read the contents of a file with those permissions.

Permissions of '111' are 'execute only' and are almost useless on a regular file. In order for a file to be executed it needs at least read and execute by the owner, and in that case only the owner can read and execute it.

If you are worried about others reading your files you probably want to use '500' that would be read and execute for just you.

For more information and what these numbers mean (octal notation) you should read this page on Wikipedia: http://en.wikipedia.org/wiki/File_system_permissions#Octal_notation

Cheers, Darryl