REMI: How do you get back to the prompts,
even if you are really stuck inside a program?
I will show you how.
So first we will show the basic ways of getting out of a program
that we already know.
So of course, you know that if I am in the rain program for example--
that's a simple program--
I can get out by--
the usual way is control C. And usually control C works.
But in some cases, in some situations it doesn't work.
Remember that vim, for example.
So if I go into vim and then type the i key and try to type some text,
then I am stuck because, if I do Control C, it won't get out.
And it will even say type :quit enter to exit vim.
But anyway, so the way is indeed to type escape
and then :q! enter, and then
I'm going back to the prompt.
Remember also, if you are in a situation where you typed a special character
and you are in a different kind of prompt,
here it doesn't do anything because it is inputting some text.
It's the beginning of a name or of an input.
So you have to finish that input by closing the single quote like this,
the same for double quotes.
Here you are stuck in input mode.
So you have to close the double quotes.
Or if you are in this kind of situation, you
can try also Control D. Control D sometimes work with only one type.
Control D sometimes needs to be pressed twice.
For example, here, if I type some text, Control D, then I
have to retype Control D. Oh, no, it doesn't work.
So you have to have a new line and then press Control D.
Also when you cat to a file, if you want to create a file,
cat>file.txt, for example like this.
So you are in input mode also.
And then you just also type Control D to get out and get the prompt back.
What else ?
Well, the worst case is you are completely stuck in a program.
Let's simulate that.
So I opened the program Rain for example.
That's a simple program just with raining drops.
And let's imagine that I don't know how to get out of this program
and that the Control C doesn't work and that the Q key doesn't work.
I try many things and Control D doesn't work.
Even if for this program it works, I want
to show you how to kill this program and get back to the prompt.
For that, we need to open a second terminal.
And to do that, there is an arrow that you have to click.
And this arrow will get you to the second terminal.
So this is the second terminal.
And if you click back this arrow, you have the first terminal.
So we still have the rain program running.
So let's go back to the second terminal.
And here what we will use is htop.
So htop will give you all the commands, all the programs
that are running for the user.
And here you can see that rain is raining and has a special number, 56.
And that number is important.
It's the PID, Process Identifier, and we could use this one to kill the process.
But within htop we can kill the process.
I want to show you how.
So with this arrow, up and down arrow, I can select the program Rain just
like this.
And if I push the function nine button, F9, F9 key,
then we have a list of some signals on the left.
And with the arrows, I can select the number I want,
and the number you would use to kill for sure a program is the number 9.
It's called the sig kill.
It will really kill the program if you are really stuck in that program.
So let's select number 9 and enter send.
So it does send the kill signal.
And as you can see, in the list now, we don't
have the rain program running anymore.
And if I click to go back for the first terminal,
you can see that it was killed, killed just here.
And indeed the rain is not running anymore,
and you have the prompt back again.
But here there is a special bug in webLinux.
So we have the prompt.
But I cannot write anything.
If you try yourself, I am completely stuck.
So in the worst case, that would be also the same thing on Linux.
If you are able to kill but then you are unable to have the prompt back working
correctly, then you would have to have another terminal and kill that terminal
or you have to reboot in the very worst case.
But usually on Linux, you never have to reboot the computer.
You can do anything with a terminal and kill everything that is stuck
or that has a bug.
Anyway, here we are very stuck.
And the simple way to reboot Linux is just to reload the page.
And if you reload the page, that is the very worst case
and you have Linux booting again.
And you will have the new Linux, but all the files will be still here.
So you know how to kill a process if you are really stuck inside.
And in the worst case, you know how to reboot webLinux by reloading the page.