Discover How To Harden My Filesystem HOWTOs
What Is umask in Linux, and How Do You Use It?
In Linux, all directories and files have access permissions. You can use
chmod to set your preferred access rights for different users. But what decides their default permissions? Let’s talk about
All directories and files have flags called mode bits that decide whether they can be read, written to, or executed. Executing a file means running it like a program or a script. For a directory, you must be able to “execute” a directory to
cd into it. Collectively the bit mode settings are called the permissions of the directory or file.
There are three sets of permissions. One set is for the owner of the directory or file. Unless the ownership has been changed with
chown, the owner is the person who created the directory or file.