How to set umask so that directories to be `r-x` and files to be `---`

Question

I want to set the default permissions for newly created directories to have r-x for others and those of newly created files (non-directory files) to have ---.

If I set the umask to 2, directory permissions get r-x but files' get r--.

I couldn't find any way to achieve what I want with umask.

Ultimately, I want others to be able to traverse the directories but not to read the content of the files. I think that is a very reasonable demand but eventually there seems to be no such setting.

Wait, you want no access permissions on the files at all? Not even for their owner? — Jonathan E. Landrum, May 27 '14 at 13:01
no. I'm talking about for others. I want to set directories to be r-x and files to be --- for others using umask. — Marcus Thornton, May 27 '14 at 13:07
Why not do something like chmod 600 foo.bar? I know that's not using umask, but it works. — Jonathan E. Landrum, May 27 '14 at 13:10
I want it to be the default setting. Using chmod, it only works on the existed files and the new files and directories still be using default setting. You have to use chmod every time once you have new files. — Marcus Thornton, May 27 '14 at 13:13
Or what about setting up umask to 7 and then having a script that runs chmod +x on directories when one is created? — Jonathan E. Landrum, May 27 '14 at 13:21
I want the permission to be set once create but not manually change the permission. That's why I wanted to use umask but not chmod. — Marcus Thornton, May 28 '14 at 09:30

Stéphane Chazelas · Accepted Answer · 2014-05-28T09:53:07.373

5

If you only create directories with the mkdir command at the shell prompt, you could have:

umask 7
mkdir() (umask 2 && command mkdir "$@")

In your shell customisation file (~/.zshrc for zsh, ~/.bashrc for bash...).

That is set the umask to 7, but redefine mkdir to a function where the real mkdir is called (with the same arguments ("$@")) with a umask of 2. (note that the (...) create a subshell, so the umask 2 is only applied within that function).

edited May 28 '14 at 09:53

answered May 27 '14 at 13:35

Stéphane Chazelas

544,893

What does "$@" stand for? I haven't seen this before. I create directories not only at the shell prompt but using java programs. – Marcus Thornton May 28 '14 at 09:22
1

"$@" provides all the arguments passed to the program. Which would be the directory name(s) passed to the mkdir function in this case. – Chirag Bhatia - chirag64 May 28 '14 at 09:38

How to set umask so that directories to be `r-x` and files to be `---`

1 Answers1