In this video I want to tell you about users.
A user on Linux is an entity that is used to grant permissions to specific parts of the Linux operating system.
And there are pretty essentials.
Users are used mainly by services on the Linux operating system.
And running services with a restricted user account avoids running them with too many permissions as the root user.
So you'll find that many server specific users exist.
People users on Linux are mainly used for IT staff as end users don't
normally log into Linux directly, but rather to the applications that they are using.
So on a normal Linux system you won't find too many users.
Let me show you how these users occur on things that you are doing on Linux.
So when I type psaox for instance, then we can see all
processes within the first column the user that has started the process.
Now I'm not interested in root and student, I'm interested in SSSD right here. That's one of the system users.
And if we scroll up a bit we should see more of these system users like
rtkit and like callord. These are user accounts that have been created for these specific services.
They are stored in the file etcpasswd and they are the
users that you will find on top of the file.
Now what do we find in this file? Now that we are at it, let's talk about it.
So here highlighted we have the LP users different field. First field has the name of the user.
Then we have an X that's a placeholder where in the past an encrypted password was stored.
Now we have the four which is the unique user id and the seven which is the group that the user is a member of.
Then LP is full name.
This is what we are talking about. The home directory is set to var spool LPD and the default shell for this user
is set to user has been no login which is good because you don't want these system users to be ever logging in.
Now of course you don't have to remember all of this. Man 5 on
passwd is giving the man page for etc where all this information is documented.
LS L also shows user related information.
So here we have that LS L where we can see that all vals have a user that is owner as well as a group that is owner.
In later videos you'll learn how these ownerships are used for granting permissions to your users.