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Pipes. A pipe is used by the shell to connect the

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output of one command directly to the input of

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another command. The symbol for a pipe is the

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vertical bar, the command syntax is command, or

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the option or the argument, and then you pipe it,

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to another command, whether it's option on

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argument if there is any. Basically, if you want

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to connect two commands together, or if you want

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to take the output of the first command, and pipe

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it to a different output, then you could use a

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pipe. In a Mac keyboard, a pipe is somewhere the

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key all the way to the right, that looks like

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that. And in a regular keyboard, you will see the

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pipe option is right below the backspace. And you

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could do I think, with the shift and pipe. So the

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way it works is you have a, you have a command, it

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goes into a pipe, and it comes out the output. So

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let's say if you have ls -l, that's a command

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you run, you pipe that, the exact same pipe

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character that you use, and you put another

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command to it to refine the output of your last

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command. So let's look at the example in our Linux machine.

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If we are in slash etc directory, by the way,

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where we are? We are in our home directory. So if

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he if we go into cd /etc, now this

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directory has a bunch of files and directories,

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which you can now view all in one page, it will

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display all at once. But everything will scroll up

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so fast that you wouldn't even able to view one by

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one. So when you do ls -ltr, you hit enter.

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You see, it went up so fast. What you could do,

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you could scroll up, of course, when you do,

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scroll down slow by slow, you're gonna see all

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those files, commands and directories that are

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inside of etc. Now you want to view all of them

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one page at a time. So how do you do that? The way

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you do it, you put it in a pipe. So first you

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do ls -ltr, you pipe it, and then, there's a

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new command that I want you to learn which is

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called more. more is the command which gives you

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the output of a file one page at a time. So when

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you do ls -ltr, pipe it, and more it, hit enter,

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so now you will see one page at a time of all the

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contents of etc directory, and at the bottom, it

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does tell you that it's more. You hit spacebar to

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go down to the second page, spacebar again,

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spacebar again, wherever you are, you could quit

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out of it by hitting Q, and you will get your

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prompt back. Again, let's do up arrow key. Hit

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enter, spacebar, spacebar, spacebar, spacebar to

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go all the way down, you will keep hitting the

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spacebar and get your prompt back. So that's how

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you put in a pipe. You could also do a pipe to

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have the output of a command and change its output

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to a different way. Let's say if you want to do

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ls, by the way, there's another command which is a

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simple command if you want it to learn is ll,

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which also gives you the result as if you are

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doing ls -l. So you do ll, and you'd learn the

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command more, which gives you one page at a time.

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What if you want to get the last line of your

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output, then you run ls -l, pipe it, and to get

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the last line you will have to do tail -1.

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It gives you the last line of your output. Now

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tail is another command which is also a cool

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command which will give you the last line or lines

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of an output, which we'll cover later on. So this

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is what the pipe is. I want you to try with

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different commands, learn about pipe. I'm not sure

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if there is a man page for pipe because it's a

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character, but let's see. Yeah, there is none. But

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if you wanted to know more about pipe, I have some

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documentation you could get it or you could of

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course go look it up online to find out more about

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pipes. The pipe is is very important for all are

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lessons that we will be covering later on because

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this is how we're going to combine our commands.

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