Permission Inheritance

Kenneth Henry · 10-07-2014, 02:06 PM

I am trying to get new files to inherit their permissions from their parent directory. So, as a test, I created a directory and set desired permissions:

Code:

mkdir content
chmod 740 content
chown ken:dev content

Now, if I cd to the new directory and create a test file, I am expecting the file to have 740 permissions, but it doesn't.

Code:

cd content
> test.txt
ls -l

-rw-rw-r--. 1 root root 0 Oct  7 14:02 test.txt

What is causing the other:read access and how do I get rid of it?

Kustom42 · 10-07-2014, 03:46 PM

Investigate two things:

umask
setuid/setgid

umask is an environment varaible that is set for every user and defines what permissions a new file/folder will get.

http://www.cyberciti.biz/tips/unders...lue-usage.html

Setuid/setgid is the 4 octal permission that allows you to provide inherit permissions in a way. All permissions are 4 digits in linux the first digit is assumed as a 0 if you only give it three.

chmod 740 is really chmod 0740.

http://www.techrepublic.com/blog/it-...rove-security/

Kenneth Henry · 10-07-2014, 04:23 PM

As a long time admin new to Linux this will require a little back up and rethink :-)

Thank you for the clear citations.