Original subtitles

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Hello everybody and welcome to this tutorial.

Today, I will go over a few basic commands

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you will need in order to follow this course

through. There are four basic commands that

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are used in order to navigate within the terminal,

or through the file system, to figure out

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where you are at the moment, to copy things,

move things, get listings of files, folders,

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see the contents, remove them, change the

ownership of files or change the modes of

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files. You will see shortly what I mean. First

off, we have "cd" which is change directories.

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If I just type in cd/home, I am going to navigate

over to my home directory. So, "cd" stands

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for change directory. As I said before, you

are literally changing your working directory.

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If you type in "cd.." you will always go one

step back. So ".." is always the previous

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folder. It's a shortcut you will use fairly

often. Next up, we have "ls." "Ls" shows you

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the listing off the current folder contents.

You can also use, for example, "ls /home/"

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and you get the listing of a specified folder

as well. Typing "ls" in and of its own give

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you the listing of the current folder, as

opposed to typing "ls" and then a path to

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a folder, which will give you a listing for

a specified folder. In addition to that, you

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also have "ls - l" which will give you a long

listing. That will tell you who the owners

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are, the size, the date, the type, the permissions

and so on and so forth. However, one of the

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more common usages of "ls" is "ls - la" to

show the hidden files as well. You might notice

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that I am not using "ll" like I generally

use in Fedora. It goes "- ll" command not

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found. I guess I could install it here as

well, but it doesn't really matter. It performs

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a fairly similar function as "ls" does, but

it's a bit faster to type in. Now I'm just

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going to go ahead and clear this. Next up,

is "pwd" which prints working directory. Some

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of you may find it confusing, but / in all

Linux-like systems simply refers to the root

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directory, to the beginning. To the root directory

from where all the files are located and from

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where everything begins. Let me just make

it clear. I'm going to navigate over to home,

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and then use "pwd." You can see that I am

in home at the moment. So, print working directory

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does exactly what the name itself says, it

prints your current working directory. Next

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up, we have our "cp" command, which we already

used in order to copy VirtualBox guest additions

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from one place to another. It's fairly simple.

You type in "cp /path" -- Let's do a real

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example. So, if I, for example, go ahead and

type in "cp VBoxLinuxAdditions.run," and if

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I want to copy it to somewhere, let's say

that I wish to copy it to "/var/". I will

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delete, of course, I will show you how to

do that as well, but it's fairly simple. You

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specify what you want to copy and where you

want to copy it to. Keep in mind, you could

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have actually typed in here a folder, a full

path, to this VirtualBoxguestadditions.run.

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You don't actually need to be in the home

directory. This "-v" option gives us this.

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It tells us what was copied where. It's a

very useful option. Let me show you what would

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happen if I didn't have that. Just like this,

you see nothing. There is no output or anything

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of the kind. This is this is fairly simple.

When you have one very small file and you

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don't really care, but when you will have

a large file, let's say it's 20GB or so, you

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are copying you'll just have a blank screen

below. Nothing will be happening. You will

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not be able to figure out whether the copying

process is going on or if it has actually

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crashed, bugged or something of a kind. Just

pass the "-v" option which is always useful

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to have simply because the machine actually

tells you what it is doing. Now, you might've

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noticed that all of these commands, more or

less, have their own arguments, which can

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be passed to them in order to modify what

the command does. You can view a listing of

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these arguments. You do not need to memorize

them all. So, let's take an example of "cp

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--help." This is a universal way of getting

help on the subject within the terminal. You

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type in the command, a space, then "--help,"

press enter and you get a listing of possibilities.

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So, I know it looks a bit messy and a bit

difficult to see, but you don't actually need

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to look at all of these things here. Just

scroll upwards and there you go. You can see

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all the arguments. They are listed clearly

here. You have the argument here, and an explanation

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of what that argument does. For the time being,

you're not going to be able to memorize all

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of these. Over time, as you practice more,

and start actually is using these commands,

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you will be remembering more, and more, and

more, and more, without actually wish it.

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Basically it will be caching the information,

so to say. Anyway, over here, in the upper

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part of this help menu you got usage. In usage,

you get the format or the syntax of the command.

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So basically, "cp" option, and then you specify

your source and destination. Very simple,

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no problems there. This is universal for all

of the commands, you can always use the help

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menu. However, in addition to the help menu,

you also have man pages. So if I type in man,

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and I can use the command "pwd." The man pages

on "pwd" give me a ton of information. You

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can see it gives you the name. It's called

synopsis here, but basically the syntax of

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the command. You get a full description of

what the command does, a full description

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of the arguments, you even get the author

who actually wrote, some notes, copyright

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and some references to something else as well.

This is a very short man page because "pwd"

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is a very short, basic command. For example,

if I was to type in, "man grep," you can see

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that the man page is a lot bigger. I'm just

scrolling down and it seems to go on. "Grep"

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is a multipurpose command which I'll show

to you in a moment. I just wanted to show

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the difference between a basic and a more

complex command. Let me just go ahead and

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clear the screen. Next up, we have move so,

"mv." That will cause a folder to move. This

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is how you rename folders too, or files. So

just go ahead and navigate over to "var,"

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where I have actually copied this file. Excellent.

If I type, "mv VBoxLinuxAdditions. I can move

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to some different folder, under some different

name, or I can just rename it within my current

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folder. If I just type

it in "RandomIsNotSoRandom." I'm just going

to rename it to that. Say ".run." You can

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put whatever extension you want. Of course,

it won't function the same. I am just showing

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you the way of renaming files. if I do "ls"

again, you see, that VboxLinuxadditions.run

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has been successfully renamed to RandomIsNotSoRandom.run.

I can also do this. I can RandomIsNotSoRandom

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to my home directory. If I do "ls," specify

a path to my home directory and press enter,

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you see that I've actually moved it here.

Unlike the copy command, it doesn't retain

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the original within wherever the source might

have been. So, once you move it, it's gone

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from the source folder, however, it's going

to appear in the destination one. Also tricky

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one: when you delete something with move,

when you move something over something else,

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it's so difficult to recover, if not impossible.

Also, be very careful with deleting files

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in Linux. Once you delete them from the terminal,

you will not be able to recover them. There

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are some complex procedures that might give

you a fraction of what you wanted to recover.

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If you remove it from the terminal. It's very,

very, very difficult. It's not like Windows

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or something. When you delete something in

Windows, you can always recover. It's like

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you basically didn't delete it. You just don't

see it. But here, when you delete something

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it's gone permanently. So take great caution,

take care but don't be afraid. I mean, over

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time, these things become second nature to

you. You will take it into consideration without

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even thinking about it. I'll go ahead and

clear the screen. Next up, we have "cat."

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Let's navigate home. Let's type "cat RandomIsNotSoRandom."

You see what it does. It actually shows you--

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this is a bit of a longer file-- all the contents

of that file, whatever that might be. This

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content is not pretty at all. You can't read

it like this, but doesn't matter. Let's just

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create another file. So, nano is my favorite

text editor from the terminal. You will need

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to learn how to use the terminal text editors

because you don't want to be switching back

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and forth between GUI text editors and working

on something a terminal. It's extremely time-consuming.

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Here on Kali Linux, you can actually edit

things with root. However, if you are using

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some other distribution or something of a

kind, most of the GUI text editors will not

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be able to run as root. You will get an error

message. So that can be a bit problematic.

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That's why you should always learn how to

use text editors that are terminal text editors.

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Just type in "nano" and type in the name of

the file you wish to create. For example,

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I'm just going to go ahead and type in "test."

Since this is a test file no need to give

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it any extensions or anything of the kind.

There we go, we are in the nano text editor.

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So here I can write some text, "Some random

text goes here." You have a variety of options.

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This carrot sign, "^X" simply means control-X.

If you press control-x you are going to exit.

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Control-O, write out, that's basically save.

You don't need this. where is, is basically

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how you search things. Hit control-V to search.

Let's look for "random" press enter and there

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you go. It's going to point to random. It

found it, no problems. Previous page don't

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need and the next page we are not going to

be that engaged with it. So cut text is also

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very nice. It allows you to actually remove

large portions of text at a relatively fast

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rate. So if I just say control-K, it's going

to remove the current line where the cursor

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is, not what you have selected with your mouse.

Just so you know. Let me just bring that back.

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I'm just going to go ahead and continue talking

about this in part two, in the following tutorial.

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Until then, I bid you farewell.