REMI : I want to show you how to create and delete folders' directories.
Let's go to the file browser right here to see what's happening.
So first, we will create a folder in the home directory.
So the command to do that is mkdir, to make directory: mkdir.
Let's name it folder.
All right.
You can see here that we have a folder in the file browser.
And if I ls, indeed, I have also a folder here.
ls -l.
I have a folder because the first letter is d, so it's a directory.
Let's get inside folder, and let's create two files.
touch file 1
touch file 2
And then, I will create a subfolder.
mkdir, so make directory subfolder.
Let's ls
And we have, indeed, f1, f2 subfolder in the folder, folder.
And what can I do?
I can go inside subfolder, and I can print working directory.
But we already know that we are in
/home/user/folder/subfolder
Let's create three files.
touch f3.

touch f4 and touch f5.
So here in the file browser, if I open the subfolder,
you can see f3, f4, and f5 are in subfolder.
All right.
Let's go back to the home directory with cd, just cd
So we are back in the home directory.
So now, how do I remove the folder?
So let's write rm folder
And it doesn't work.
It says folder is a directory.
Indeed.
So how do I do that?
Well, I have to recursively delete the folder and the subfolders,
so I have to do rm minus r to say recursively.
And then, the name of the folder: folder.
And it worked.
I have, indeed, deleted folder and all the content.
So you have to be very careful because it's very powerful,
and you can get rid of a whole folder without any notice.
Let's try to recreate that folder.
mkdir folder.
I go inside.
I create a file, f1, another one, f2.
All right.
I go back to the home directory.
And this time, I will add an option, that is i, so rm minus r and then i.
So I have double options.
And this i will ask me-- so I will delete folder--
will ask me each time it does something that is--
each time it does something that is dangerous.
For example, descend into directory folder.
Yes.
I have to answer yes with a y.
Remove folder slash f3?
Yes.
Remove folder slash f1?
Yes.
Remove directory folder?
Yes.
So you see here, I have to each time confirm
that I want to remove or go inside a specific folder
and remove what's inside.
So I have to answer yes, yes, yes, yes, all the time.
And a very, very funny way to do that, I will show you how to do that.
mkdir folder.
Let's go inside.
Let's create f1 and f2.
Let's go back to the home directory.
And one funny way to answer yes all the time is to use the yes program.
So if you just try the yes command, like this, and press Enter.
It will just display yes, yes, yes, yes, yes all the time.
So it will just output yes all the time.
And to quit this program, you have to hit Control C.
And then you have back the command prompt.
So yes is used to push the y key multiple times.
So I can use that as an output.
So I use yes.
And the output of yes, which is I type the y key many times,
I redirect it with a pipe command like this.
I redirect it to the command that I just wrote before.
So it was rm -ri, and it was asking me--
and also folder.
And it was asking me many times if I want to do this, or this, or this.
And here, because I redirect the output of yes into the input of this command,
it will answer yes all the time.
So let's try that.
And let's try to
hit Enter.
And you can see all the questions that were answered by yes.
That was quite funny, a funny way to do that.
All right.
So the last thing I want to show you is how
to create many directories in one command.
So mkdir d1 d2 d3.
And, indeed, I have three directories.
But what if I want to have d2 inside d1 and d3 inside d2?
So first, let's delete d1.
Let's delete d2.
And let's delete d3.
And now, what if I want to have like d1 and inside d2 and inside d3,
inside d4, inside d5, et cetera.
Let's write mkdir, d1 slash--
with a big D. It's faster.
D1/D2/D3/D4/D5
Enter.
And it doesn't work because we cannot create a directory with slash
in the name.
And that would be the name of the directory, D1 slash D2 et cetera,
and it's not, of course, possible to have
a slash in the name of a directory.
So anyway, to create this--
all these subfolders, you have to use the option minus p.
So mkdir -p and then D1/D2/D3/D4/D5 .
Enter.
And here, I have D1 and inside D2 and inside D3 and inside D4 and inside D5.
And, indeed, if I go to D1, I can see that there is D2.
And if I go inside D2, I have D3, et cetera.
Let's go back to the home directory, and let's do rm -ri D1.
Do you want to descend into directory D1?
Yes.
Into D1, D2?
Yes.
In D1, D2, D3?
Yes.
D4?
Yes.
D5?
Yes.
Do you want to remove this one?
Yes.
To remove this one?
Yes.
This one?
Yes.
This one?
Yes.
And this one?
Yes.
All right.
And the last thing just for fun, let's try to do again this one.
And then, I will use the yes command and redirect it into rm -ri.
And delete D1.
And here, you have all the questions with all the answers--
yes, yes, yes, all the time.
All right.
So you know how to create and delete folders and recursively delete folders.
So be careful.
You have to use the i option of the remove command.
So if you go to the help, you will have a little bit
of help for the remove command.
And here you see that you can always prompt before removing with an i.
And you can never prompt with an f also.
This is very dangerous.
And, of course, you have to use the recurse option to remove folders.
You know how to use the remove all folders now.
Try it yourself!