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To get the most from your Linux system, you need to understand environment variables and be adept adept

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at managing them for optimal performance, convenience and even stealth.

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So among the areas that the Linux newcomers find problematic, however, managing the user environment

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variables might be the most difficult to master.

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So technically, there are two types of variables.

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The first is shell, and the second is environment.

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So environment variables are system wide variables built into your system and interface that control

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the way your system looks, acts and feels the to the user and they are inherited by end charge shills

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or processors.

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Social variables, on the other hand, are typically listed listed in lowercase and are only valid in

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their shell.

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They are set in.

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So to avoid over explanation, I just, uh, cover some of the most basic and useful skills for environment

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and shell variables in this lectures and don't go too deeply into the differences between them.

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So variables are simple strings in key value pairs.

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So again, or generally, each pair will look like this, for example, key and value key here and add

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value here.

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So.

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In cases where there are multiple values, they will look like this is a value one value to and value

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three and vice versa here.

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So as with most things in Linux, if there are spaces in the value, it needs to be contained in a quotation

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marks here.

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Like that?

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While the fourth.

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So.

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So in in your environment, in your shell is your best shell.

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So each user, including ruled, has a different set of environment variables that determine how the

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system looks, acts and.

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So you can change the values for these variables to make your system work more efficiently.

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Tailor your work environment to best meet your individual needs and potentially cover your tracks if

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you need to.

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So leaving and modifying environment variables so you can be while your default environment variables

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by entering any V into your terminal from any directory like so here.

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So as you can see, there is a light environment variables here.

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So environment variables are always upper case, as you can see here.

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So, including shell variables, local variables and show functions such as any user defined variables

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and command aliases, some use a set common this command will list all environment variables.

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Um, on environment variables unique to your system, which is the most cases will give you an output

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so long you won't be able to view it, uh, on a single screen here.

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So you can see here.

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We have so many environment variables here.

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As you can see here, we can see, because it's so many here, so, uh, we can do like that, sit here.

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Said.

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And more here.

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Now we can see like that by pressing enter.

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We can see a sequential.

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So let's see more more and, uh, press in one time control and save or exit or quit here.

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So now the last three of us here, as you can see here, feel, uh, will fill up on a screen line by

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line and then stop.

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Uh, when you press enter like that, uh, or space or, uh, spin in space and you will see more here.

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Uh, so, uh, taking you to the next variable so you can scroll through pressing or holding, enter

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like that.

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So.

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As you might recall, from previous chapters and elections, whenever you you use, the more common

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for output you can enter key it to or exit and return command to like that or control plus easier.

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So filtering for particular variables?

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Let me, uh, see here.

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So, uh, I'll talk to you using sent, uh, with more gifts, more, uh, manageable results than working

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through the whole chunk of variable names you get with this sit along like that.

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Uh, so.

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It can still be a rather tedious if you are looking for a particular variable.

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Instead, you can use the filtering command grant, um to find your variable of interest.

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So let's use the variable his size as an example.

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So this variable contains his size on this variable contains the maximum number of comments you were.

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Common history of a file was stored.

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So his size is the maximum and number of commands your command history file will start to his commands

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or any was previously typed into your command prompt in the session and can be recalled with your up

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here, up and down, uh, keywords like that.

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So you're not at his size, doesn't store the comments themselves, just a number of them that can be

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stored so popular, sit here said, Oh crap, actually cramp his size.

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Yeah.

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Well, as you can see, his size is 1000.

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As you can see, the common finds the variable, his size, and this place is its value.

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The default value of this variable is probably set to one thousand here, as you can see on your system,

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too.

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So this indicates the terminal this storage would last 1000 commands by default.