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Hello, the beautiful people.

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And in this video, you're going to begin to use the command line to move around your Linux file system.

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Very, very exciting stuff.

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Now, once you learn the techniques that you'll learn over the next few videos and begin to use them

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for your everyday tasks, you'll begin to find that they are faster and more effective than the graphical

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point and click methods that you are most likely using right now.

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So in this video you're going to learn how to use the P and the less commands to know where you are

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on your file system and what is around you.

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And by the end of the video you'll know where you are on your file system and what's around you using

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the command line, and you'll be ready to start moving around using some other commands that I'll show

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you in the next video.

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So I hope you're very, very excited.

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Let's go ahead and jump right into it.

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Okay.

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So here we are in the terminal.

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Now, the first thing we'd like to know when navigating the file system is where we currently are.

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And the shell already tells us this.

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Over here on the left, you'll see a bunch of text that is known as your shell prompt.

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And the shell prompt.

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Is everything up to this dollar sign?

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Now let's break it down and show you what each bit means.

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First of all, it tells you the user of who is logged in, which is Zeyad on this computer.

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Then you've got an app symbol, then you've got the name of the computer, which is VB.

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We called it this when we set up an install the virtual machine and VB is short for virtual box, then

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you've got a colon, which is these two dots on top of one another, and then you have this squiggle

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that's called Tilde.

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Now in the bash shell, which is the shell that we're currently using, that tilde, that squiggle is

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a short way of representing the current user's home directory.

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So whenever you see that, Tilde, when you see that squiggle, it just means the path to the current

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user's home directory.

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So our shell prompt is basically telling us that we are in the home directory for the current user,

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which we can tell is Ziad.

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So we can actually confirm at any time what directory or what location our shell is currently operating

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in by using the P command.

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Now the P command stands for print working directory.

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The command will just tell us the folder that our shell is currently operating in.

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So if I type P and I hit Enter, we'll see the full path to my home directory appear, which is slash

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home slash Ziad.

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Now the path starts all the way from the root directory, the very base directory which is the slash

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and works its way down until we get to the home directory for the user, Ziad, which is me.

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Now we can actually see this if we click on our files and that opens up.

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Now if you click on other locations, then click on computer.

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This will open us up in the very base directory.

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This is the this is the base directory for the system.

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Now, if I click on home up here, then click on Ziad.

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That is where we currently are in the shell at the moment.

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Now, because the path starts all the way from the base directory, from the slash, it's known as an

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absolute path.

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So now that we know where we are and we know that our shell is operating inside of our home folder,

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how can we take a look around and see what's in the home folder?

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Well, first of all, we could do it using a graphical user interface.

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We could click on our files here, and that's automatically going to open us up in our home folder.

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And we can see this folders such as a desktop documents, downloads, pictures and so on and so on.

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Now to see something similar on the command line, we need to use the L.

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S command.

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Now the LS is short for list and the LS command will list out our files in the directory.

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So if we take a look at the main page for ls the manual page for ls will see that ls can take a path

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to some folders.

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It says here file says list information about the files, which is the current directory by default.

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As a side note, LS does not accept standard input, so you can't pipe to it and instead you need to

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give it everything as command line arguments.

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That's just an aside.

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Okay.

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So now let's try and use the LS to the command to see what's going on in our home directory.

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Now there's multiple ways to do this.

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I could do with the long way and I could give it the full absolute file path.

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I could type ls slash home slash Ziad.

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That's the long way to do it.

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Or because I know that the tilde represents my home folder.

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I could give it a shortcut.

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I could do ls then give it the tilde.

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And that's exactly the same thing.

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The tilde is just the home directory and for the current user it's just a shortcut.

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Or even better because I know LS will by default list out the contents of the folder that I'm currently

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in.

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And because I'm in my home folder I can just type ls ls will by default list out the contents of the

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directory that your shell is currently in.

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And because we're in our home folder, I can just do ls without any command line arguments.

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So let's go ahead and do that.

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There we go.

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So in there now what's come out, we can see several blue words now by default, blue text from the

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LS command indicates folders.

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But to make that clearer, we can we can give the LS command the uppercase F option.

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So we put a dash on an uppercase F and F is meant to mean classify with emphasis on the F.

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So now when I do that, if I do ls f now we can see that the items that have a slash at the end are

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folders.

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Now if I just make a file in our home directory by echoing the word hello into it, I'm going to call

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it file txt.

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So here we're using redirection to create the file.

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There it is.

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You can see there's been made.

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If I knew and if I now do ls dash f we can see that the folders all have slashes after them and are

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in blue, but the file itself doesn't.

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Have a slash after it and it's text is in white.

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So you can see that the LZ command allows us to see the difference between files and folders, files

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and directories.

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But something to bear in mind is if I take that LSB f output and put that into another file called list

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txt, then I open up a list of txt.

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You can see that there is no coloring, but you can see the difference between folders and folders and

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files just by looking for the things that end in slashes.

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Things that end in slashes are the folders and the things that don't are the files.

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So, you know, this is really good if you want to save the information to a file and be able to tell

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at a glance or have make a program tell at a glance, what's a folder and what's not.

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So you can selectively operate on specific files or not.

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So it's just a call it or shortcut.

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Okay.

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Now a much more useful option than the F than the F option for the LS command is the l option.

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Now if I do ls dash l actually let me clear the screen first.

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If I do ls dash l.

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This puts everything in long form format and you can tell here that we get a lot more information about

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our files and directories, including the file permissions over here on the left.

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Anything that starts with a D is a directory and then there's file permissions.

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So for the user read, write, execute for the group the user is in, the group being here is this column,

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the user is this column.

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So the user read, write, execute for the group, just read and execute.

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No writing and for everyone else just reading and executing.

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Then you've got the user that the the file belongs to the group.

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The file belongs to how large the file is when it was last edited and what the file is actually called.

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Okay.

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So this is a this is the LZ dash command is a command that you'll use probably very, very often because

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you can get a lot of information about your files, much more than just using the normal LS command.

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The other thing I should mention is that this column here with all the numbers in the file sizes, this

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shows the file size in bytes.

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And to make that a bit clearer, you can give the LS command, not only the L option, but also the

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Hatch option.

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And the Hatch option stands for human readable.

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It makes the file size a bit easier to read.

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So if we do ls dash l hatch, we can now see that it's telling us that the desktop thing is about four

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kilobytes.

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This is about four kilobytes.

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This one is just six bytes.

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This is 93 bytes and these are four kilobytes.

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If you had things that were megabytes in size, it would it would say an m If you had things that were

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gigabytes in size, it would say a G.

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And in general, it just makes this stuff a bit easier to read.

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So that's the dash with the with the L option.

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You've got the the permissions on the file.

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So it begins with a D, it's a directory, it begins with a dash.

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It's just a file.

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The first three things are the permissions for the user.

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Read, write, execute.

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The the next one is for the group that the that the file is in the in this case it just has read and

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execute but no.

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Right.

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And then this third column is for everyone else.

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This is the so just read and execute in that sense.

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This is the amount of hard links to the file.

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But don't worry about those.

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This is the user the file belongs to.

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This is the group the file belongs to.

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This is the file size in bytes.

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This is the date the file was last edited and then this is the file itself.

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So I'll make sure that that information is available on the cheat sheet at the end of the section.

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But now you can start to see if I clear the screen the we can now use the p command to see where we

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are and the RLS command to see what's around us.

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All that's left to be able to understand is how to use the command to actually change where we are on

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the file system so that we can move about.

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But I think in the interests of time, we're going to save that until the next video.

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So in the next video, we're going to be covering how to use the CD command to actually change where

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you are on the file system and also be going through a few examples to see how these three commands

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work together to help you navigate the file system much faster than would be possible using just pointing

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and clicking.

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So for all that goodness, I'll see you in the next video.