- So you have just learned
about the Linux basic permissions.
The thing about these Linux basic permissions
is that they were introduced a long time ago.
Now Linux is based on Unix
and Unix is a very old operating system.
It comes from the early 1970s
and it means that the original idea
of working with permissions was a bit limited.
And that is why we have had
a couple of improvements to the system.
And one of them is the Advanced Permissions.
So let's talk about the Advanced Permissions.
To start with, there is Set User ID,
also referred to as SUID
with an octal value of four.
Set User ID on files means
that you run the file as the user owner of that file.
And I will show you what that's all about
in just a little bit.
Set Group ID or SGID with octal value of two.
If you apply that on a file,
then it means that you run the file
as the group owner of that file.
And if you run it on a directory
then it sets the ownership
on newly created items as the group owner of that directory.
In case you are wondering,
hey, on Set User ID
you didn't tell us what it's doing on a directory.
Why is that?
Because it has no meaning on directories.
Set Group ID has a meaning on files and directories.
Set User ID only has a meaning on files.
And Sticky Bit only has a meaning on directories.
And the meaning is that Sticky Bit
on directories allows a user to delete files,
if the user is file owner or the user is directory owner.
Now this needs a couple of demos.
In the next video I will demonstrate all of these.