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Hello, the beautiful people.

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Knowing the last video you learned about the structure of the Linux manual and you saw the way that

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it was broken up into eight sections and those eight sections each deal with a different part of the

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Linux experience.

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Now we're going to take that theory from the last video and we're going to turn it into practice in

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this video.

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So in this video, you're going to learn how to search the manual and discover new commands.

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You can learn how to access the manual pages for those commands, and you're also going to learn how

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to read them so that you can go out there and independently learn how to use new stuff.

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So by the end of this video, you'll have the independence to search for new commands and learn about

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how they work.

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And this is going to put you in the driver's seat because it makes it possible for you to gain more

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control over your Linux system because you can start learning independently about how everything works

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rather than waiting for random changes that you randomly bump into learning new commands.

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So you can take a lot more of an active role in your learning and your development of the Linux operating

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system.

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So let's go ahead and get right into it.

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Okay.

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So now that you know that the manual is broken up into eight sections, how would you know what section

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to look in to find what you're looking for?

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Well, let's say that you wanted to look up information about the Witch Command.

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First to search the manual, you would have to use the man command.

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Now, the man command is short for the word manual, and it's the command that deals with everything

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to do with the manual, basically.

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And this is why they're actually called man pages, because it's the man command that looks through

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the manual.

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Now, that's the command name.

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So we're good at that.

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Now we need to give it any options if necessary.

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We're actually going to use the Kay option, which is what deals with searching.

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So we've got command name, then options.

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Now it needs an input and the input that we're going to give it is the search term.

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So we type which so we've got a command name, we've got our options, we've got our inputs.

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The same general structure that I was telling you about before.

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But now what we're doing actually is we're using the man command to search the manual for this search

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term, this search term here called which.

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And it's going to look all the way through the manual and find anything that might be relevant to that

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search term.

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It's like your own mini search engine for your manual.

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So if I press enter, we get quite a few lines of output here.

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So let's let's have a look at what this is on the left here.

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You're going to get the names of certain manual pages.

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So every single one of these is a manual page that is appropriate to this search term.

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And on the right, you get a bit of a synopsis about that actual page so you can pick which one might

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be most appropriate.

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And the other thing is in the parentheses here, you get the section number of the manual that that

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page is in.

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So, for example, this command, this this manual page is in the first section of the manual, which

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means it's a user command, whereas this one is in the eighth section of the manual, which means that

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it is a more system, administrative kind of thing.

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And this one is a in section five, which is going to be about file, file configuration, how the files

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are structured and things like that, information about how files are structured.

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So there we go.

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We can actually see at a glance whether it actually suits our needs or not.

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And if we decide that we want to take a further look, it seems like this one is exactly what we're

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looking for.

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It's in the user command section and it's a command that locates a command.

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We can actually take a deeper look at that by using the main command again, then the section number.

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So the section number is one and then we type the search term.

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Oh, sorry, the page name which is on the left there, which is which.

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And if I press enter Dada, we've opened up the manual page for the Witch Command.

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Now it's only very small and once we've opened that to close it and get back out, we just press the

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Q key on the, on the keyboard.

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So I press the letter Q and I'm back out on my command line.

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So, for example, we could open up this soul section here, this soul thing by doing Man six because

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it's section six.

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So and I press enter and it opens up that, that manual page for soul, which you can see at the top

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right there now because the first section of the manual is used so often, you don't usually have to

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type the number one.

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Even so, instead of typing man one which as a nice shortcut, I can just type the word man, I can

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just type man which, which will open up the same page, the same manual page.

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And you can see that it is indeed in section one.

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So that's a shortcut.

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If you see that something is in Section one, you don't need to type the one, you just type the actual

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name of the page.

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So like up here we've got LCF, right?

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LCF is in section one I type man LCF and we see that we are now in the LCF man page in section one,

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which means that it's a user command.

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So that's how you would open up a manual page.

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And up next now we're going to take a look at how you would actually read it.

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Okay.

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So let's take a look at the man page for the Witch Command.

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So I'm just going to type man and then which and because it's actually a command that I've used very

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recently, I could have just pressed the up arrow key a couple of times and I get back to the same result.

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So I press man which press enter and we've opened up the manual page.

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Now we can see that this manual page is actually broken up into the following sections at the top.

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We've got name, then we've got synopsis, then we've got description, then we've got options, then

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we've got exit status.

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Okay, now other sections that a man page may include are examples, a C, also section and environment

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section.

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Things about bugs, things about authors, things about reporting bugs, history of the command, copyright

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things, stuff like that.

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But this is what we get in this specific manual page.

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So they're not always structured the same way, but they usually follow this kind of structure.

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Okay, now in the name section, we see that we are dealing with the Witch Command and we see a little

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bit about what it does.

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And this bit is actually what came up when we searched the manual in the first place.

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This is exactly what came up.

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We saw the name and then we.

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Had this little piece of information on the right hand side.

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Um, now in the description section, this is where you, this is where you really see what the command

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does.

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And the description section is a very important section, and it gives you a much more in-depth description

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of what the command actually does.

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This is likely going to be one of the most useful parts of the main page for any command, and as it

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will try to explain what the command does in plain English.

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Okay, so you've got the which command description there and up here you've got the in the synopsis

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section, we can see a layout of how to actually use the command.

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A Ha.

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So you remember when I was telling you that each command is structured differently and you need to read

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the manual pages to see how to use a command?

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Well, this is the section of the manual page that will tell you how to use the command, the synopsis

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section.

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So for the Witch Command, we can see that first we type which the command name and then we see the

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a option in some square brackets which we'll come onto in a minute and then some kind of file name and

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then three dots or other also known as an ellipsis afterwards.

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So let me explain what this stuff means.

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So first we enter the which command name we just type, which then we have the a option which is optional.

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Now we know it's optional because it's inside these square brackets in a man page.

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If something is inside square brackets, that means it's optional.

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You don't have to enter it, but you can.

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Now, next after that, once we've entered our optional option, we next you have to enter the name

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of a command that you're actually looking for.

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Now you can see so so you enter a name of what you're looking for.

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So for example, which may be Dash A and then echo.

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Okay, that would show you where the Echo command was.

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But you also see this ellipsis or these three dots.

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Now, these three dots mean that you can enter more than one file name.

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So in other words, the which command can take more than one input?

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Ha.

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Things are starting to fall into place now.

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Right?

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So how do you know how many inputs a command takes?

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Will you look at the man page?

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You look at the synopsis, and it will tell you how many inputs it takes.

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Okay.

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Now, just to prove it.

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Okay, just to prove this, we're going to take what we've learned here and we're going to apply it.

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Okay.

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So I'm going to go back I'm going to clear the screen press by holding control now.

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And we're going to see we're going to try and use the which command to find the date command and the

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command at the same time.

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So we've used the which command.

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We didn't give it the a option, but we didn't have to because it's just option, just optional because

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we because it was in the square brackets and we've given it a one file name and then another file name.

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So if we press enter Dada, we see that we get two outputs and that it's found the locations of the

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date command and then the Cal Command.

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We didn't need to run the command twice because if we look at the main page, it tells us we can actually

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give it more than one file name.

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So that's really, really useful.

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And maybe not.

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Maybe something we wouldn't have known had to do if we had not looked at the main page.

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And as I said, the things inside square brackets in the main page, let me open up again.

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Things inside the square brackets are optional.

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This kind of stuff you don't have to have, but you can have.

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And if you want to know what it does, you just go to the options section.

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So if I put in the A option, it says it'll print all matching path names of each argument.

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So all matching path names.

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So A is short for all.

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So what I could do is I could type, which I could do which date and cow, but I could type dash a and

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see if that does any difference.

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It actually it doesn't make any difference, but it will show us all of the different all of the different

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results.

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So maybe, you know, when I told you about searching from searching on the path, maybe this would

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allow us to look in folders that were later on in the path if they had the same name as where they were

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earlier on.

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So there we go.

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Now there's other symbols in the manual pages, such as angle brackets.

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So these kind of things, right?

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So if you have something inside here inside a manual page, so if we had like which and then it was

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like this and then you had something inside angle brackets, anything inside the angle brackets is mandatory.

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That means you have to have it.

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Okay.

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So if you see something inside angle brackets, that means you have to have it and you can't miss it

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out.

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All right.

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So just bear that in mind.

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There's also the pipe character.

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So if I had an option here and it was something like, say, you had the F option because there's a

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pipe character between the two options, that means that you have to pick one or the other.

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Okay, so the pipe means one or the other.

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You cannot have both.

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So I couldn't type I couldn't type a which which does a f date.

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I would have to type which dash A or which does F.

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I couldn't have both.

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That's what happens if you see something inside inside angle brackets.

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So I'm just going to type my finger again, angle brackets with a pipe in between them.

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Okay.

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So what we're doing so far.

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Okay.

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It's probably what you'll come up with most of the time.

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So these are all the different things that you'll see.

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You'll have the command name.

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You have some options.

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It'll tell you which ones are optional and which ones you need and which ones cannot be combined with

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others.

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You'll see things that maybe are mandatory inside square brackets.

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Anything with a dot, dot, dot after it means you can have more than one thing.

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So if it had like this, it was file name, wasn't it?

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And then dot, dot, dot, that means you can have more than one file name when you use this command.

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Now I'm actually going to put a PDF in the resource in the resource section for this lecture that lists

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out what the different symbols mean.

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So you can use it if you ever need a quick refresher.

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But that's pretty much all you need to remember.

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Okay.

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Just the anything in square brackets is optional.

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Anything with a pipe in between it, you can only have one or the other.

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Anything in square, anything in brackets is mandatory.

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And I think with dot, dot, dot after it, you can use more than once because that's pretty much all

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you need to know.

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And if you want to know how to look up what different options do, just scroll down to the options section

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in the main page and it'll tell you exactly how to use them all.

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Okay, awesome.

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So we've covered a whole lot of stuff in this video and you should start feeling a lot more comfortable

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using the command line.

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Already in this video, you saw how to search the manual using the man command with the K option, and

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after that you can give it any search term that you want and the man command will search the manual

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for that search term and give you a list of results as well as what those results are and where section

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of the manual page they're in.

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You saw how to access those specific manual pages and also how to read them for specific command structure.

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So we saw how how to actually use the which command using its manual page and we saw the different symbols

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that might come up in the manual page and tell you how to use it.

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But I've attached to cheat sheet in the resources section for this video that I massively encourage

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you to use and keep on hand, because it's going to give you an explanation of each of the different

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symbols that might show up in a manual page so that you can keep that to hand and make sure that you

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don't forget anything but to ensure that you don't forget anything.

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Up next, we're going to have some practice.

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What we're going to do is we're going to go together and we're going to look at we're going to search

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for a new command and we're going to read about how it works.

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We're going to look at its manual page, and we're going to take that learning and actually apply it

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and show you how the how you would take a man page that you've never seen before and learn how to use

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it.

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So we're going to be applying what we've learned in this lecture about reading manual pages and apply

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it to a completely new command and go through it together.

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And after that, you should definitely feel as though, hey, any command or any manual page that I

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come up against, I'll know how to read and know how to use, which is going to give you a massive boost

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of confidence and a massive boost of independence for you to explore and learn more about the Linux

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operating system.

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So let's go ahead and jump into the next video and get some super, super cool practice.