"Have you ever attempted to do something with a file on a Linux
machine and been given the error “permission denied”?
For some people this isn’t a problem, either su to the root
user or use the sudo command to help you along. For some users,
however, this can be very frustrating. Why? When you don’t
understand file permissions, using and (especially) administering a
Linux system can be a real pain. Even though you can read an
extended listing of a file and see drwxr–r–, if you
don’t know what that means (or how to manipulate it) what
good is that extended listing? And what good is that file if you
can’t access it (when you need to or should be able to)?
"In this article I will introduce you to Linux file permissions
and how to manipulate them. I will show you how to manipulate
permissions from both the command line as well as the GNOME gui