You working with Linux is knowing your commands.
So let's have a look at some essential commands to get started with.
These are whoami, who's shown who you are.
LS for listing information about files.
Ipa, which is showing IP address configuration, cat, which allows you to read
text files, and and passwd, which allows you to change your password.
I also like Touch, which allows you to create an empty file, or
pwd, which is printing your current working directory. Let me show you.
To start with, I'm using who am I and who am I showing? Well, my current username.
Have you seen that the current username is also in the prompt? So in the prompt you can see that I'm student at localhost.
And then we see a colon tilde.
The tilde is indicating my current working directory.
You can request that directory using PWD for print working directory.
And oh, by the way, the dollar at the end of the prompt is an indicator that shows that
I'm currently logged in as a non root user, an ordinary user, also known as a non privileged user.
Let me type LS LS is showing files in the current directory.
If I use touch new file then the result is that I just created a new file, an
empty new file that is meta name newfile in case you are wondering what is that good for?
Well, this allows you to verify that you can write into a directory that's actually pretty useful.
Let's verify that the file really is empty by using cat on new
file. We see nothing. Yeah, that's on purpose because the file is empty.
Can we do that on another file? Well, when I use LS A,
then I can see files that have a name starting with a dot.
They are effectively hidden files.
But the Linux operating system doesn't know about hidden file properties.
And that is why there's a convention. And the convention is that if a file has
a name that starts with the dot, most utilities won't show the name of the file.
So I want to show you the contents of this bashrc and this BASHRC is
a startup file. And look at that, that's all the contents that it has.
For now we don't care about the contents that much. It's about showing the contents of configuration files.
Now I would also like to show you the PASSWD command. PASSWD allows you to change your password. Before
doing so, you do need to enter your current password and then you need to enter the new password.
Oh boy.
It's complaining that the password is the same as the old one.
And then we get an authentication Token manipulation error.
Now that's not very obvious what it means, but what it means is that it has failed to set your password properly.
And for that reason the password is unchanged.
For now, I'm just going to leave it as is. I'm okay that the password is unchanged, unlike my previous password.
I want one more thing, and that is ipa.
In Linux, frequently you want to access your Linux system remotely.
And in order to access your system remotely you need the IP address.
IPA is showing the current IP address configuration.
On most Linux distributions you will see at least two interfaces.
There is the LO interface with the IP address 127.0.0.1.
This is the loopback interface and it's used for internal communication.
The interface that really matters is right here, the ENS160 interface.
The name of that interface depends on your Linux kernel.
So if you see something that is not ENS 160, that's okay, don't worry about it. That's completely normal.
The thing that you want to know about your interface is which IP address is it using?
Well, here highlighted we can see the IP address 192.168.29.137.
So if I ever want to access my system remotely, this is the IP address that I need.
Oh, and did you notice that on Linux all interfaces also have an IPv6 address?
Don't worry about these IPv6 addresses too much. Most people don't use them, but they need to be here.
And if ever you need to know about it, IPA
is not only showing IPv4 but also IPv6 addresses.
For now, that is enough about commands. You now have knowledge of a couple of
commands and that makes it more useful to continue with the next couple of videos.