Hello and welcome to command line
BASIX video.
We're going to go over limbic system
commands to Christopher Haler
and let's begin.
So relending, objectives for this
video. We're going to learn the
command, understand the last command
in the command and learn the
kill command as well as a very
useful system commands in order to
manage and manipulate your
system into what you needed to do
assessment.
The command lists all
running processes by default.
Is that true or false?
The answer is false.
It will only list the running
processes for your user account
by default.
In order to list everything that is
running on the machine, you're going
to need to use the A
switch as well.
And we'll learn then this video.
So ID with the ID command
is used for it is used to print
user and group information
and it can also show permissions for
other users as well.
So this is a useful command in order
to quickly understand the
permissions for users
who are groups that are part of an
on that.
So if we jump over to my
Linux machine, I can
do the user
because this is my user account name
and we'll show all the groups.
And I'm a part of this as.
So this is my user ID
here, one thousand the
group ID and a whole
bunch of different groups that I'm a
part of.
So important to understand.
And we can use it for other
accounts as well.
So let's say ID
and you can see you had
zero. That is always the root you
and then it's in the root group and
the group ID as well.
So very useful to find information
about a user account.
Now the last command, what this
command does is it shows the users
that last log into the system
and also choose exactly what exactly
to use to log into the system
if it was remotely over
succeeds or if it was with the
keyboard and also show when
the system booted as well.
So this is useful in order to kind
of keep tabs on exactly how users
are authenticating to the computer.
So over here, I'm going to get
back to my Linux show and I'm going
to type last
and check it out.
You can see that I've logged into
the machine a few times and reviewed
it a few times.
So the last time I logged in was
Saturday, September 14th at fourteen
forty seven.
And it is still running.
I have not logged out yet.
And this reboot I did
at fourteen forty seven as well.
So this is useful in order to
keep track of user accounts and have
their log in.
So the come in.
This is what we were learning about
in the previous ESP and where it
will display running processes on
the system.
So it only displays the
current user processes by default
as well. And if you want to be able
to see all the processes on the
system, say a
UX, now these
switches, the UX, which is do
not have that dash in
front of it. So keep that in mind.
Right. So let's take a look.
I'm going to type and you can see
I'm running Basche and then the
command as well, because it
is a program that is running through
Basche.
So we can see the process ID or the
PID for these commands
as they run as well.
Now, let's say I want to see
everything on the machine, so
I'm going to types a UX
and this shows everything running on
the machine and the
commands that were used to
submit them to start them as well.
So this is useful to see exactly
what's going on with your Linux
machine at one time.
All right, we have the kill
command with kill commandos
is ends a running process,
and the best way to do this is
to use the overprocessed night
where you know exactly which one is
going to be ended.
So this can be used to either
help and a
process that is frozen, a process
that you did not mean to start or
something that another user left
running up when they were logged.
And it's heating up system
resources.
So it's important to be able to
feel comfortable with the kill, come
in and use it to end processes as
you need it to.
So let's go back over and
I'm going to start a new process.
I'm going to start Terminator.
And as you can see, the Terminator
program we installed in a previous
video.
And when this starts up
as twenty seven, eighty eight,
this is the PID for this new program
that we just started.
And if you're not aware already
having the single ampersand after a
command in a Linux shell,
it sets it up in the
background. That way we
still have control of our show and
we'll learn this in a later video.
So don't be worried about it.
Now, Stipe's again.
And as you can see, we have the
Terminator program running the
twenty seven eighty eight
and we still have this
window up so you
can see the window in the background
a little bit.
Now it's type two
and twenty seven.
Eighty eight.
And as you can see that window is
going in the background and if we
type again that
program is Terminator.
So this is a very useful way in
order to end the process that
you may not want started.
We're still learning.
And it's important to keep in mind,
too, that we can end other user
processes if we're using the root
account is the root is in charge of
the entire system so we can use it
and kill any other running
for any other user.
All right. Post assessment, the kill
command can be used to end other
user processes.
Is this true or false?
And the answer is true.
I hope you got this one right
because I just said it.
So using the root account,
we can end process is running on
under other user accounts.
This is a very useful way in order
to be able to make sure that
we can keep control over our
system or any processes
or processes that are using way too
many resources.
So in this video, we learn the
command understood the last command
of the command and learned the kill
command. And I hope to see you in
the next video.