So you need to create a useful linda, we already have a useful linda. And open a shell as disuser.
So let me open a shell as usual linda. And here we go, su minus linda, entering the password
for the user. And then we are in. Oh my goodness, why doesn't this work? Well, I know why it
doesn't work. That's because we locked useful linda in a previous lab, didn't we? So what
we need to do is pass wd minus minus help, pipe less to find out the unlock option. And
that is minus u. So pass wd minus u linda. That should be doing better. So back to the
linda shell and try it again. Here's the password for useful linda. And that is working so much
better. Good. As linda, we need to run two background processes, sleep 600. So here we
have number one, and number two. And oh, one of them with the highest possible priority, the
other one with the lowest possible priority. So as useful linda, I'm going to run two sleep
processes with the highest possible priority. How does that work? Well, nice, minus n minus
19. That's the highest priority, right? On sleep 600 with an ampersand behind it. And there
we get a permission denied. Why do we get a permission denied? Well, that is because users
cannot run processes with a higher priority. That requires system administrator
privileges. So I might as well forget the nice command and run this sleep 600 in the
ordinary way. The other one, nice minus n 19. That's with the lowest priority. That is
something that we can do. And then use the most efficient way to terminate all current
sessions for user linda. Well, shall we try killall minus minus help, where we do have a
minus u, so killall minus u linda. That should be doing it. And next, if you use ps aux pipe
grep linda, we can see that we still do have a bad shell for user linda. And that is it. The
sleepy processes have been terminated. And that is what you needed to do here.