Variables

Name: Variables
Author: Jeremy Kurtz

Discover how to use, format, and modify variable types to enhance your interactivity with Linux

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Course: On-Demand

In this lesson, we're going to talk about variables and how they relate to shell scripts. The first set of variables we wanna take a look at is the environment variables. Environment variables are variables that remain constant while you're in a terminal session. To take a look at an environment variable, you use the command p r i n t e n v for print environment. Once you've done that, you can now list after a space any one of the many environment variables you have available to you. For example, if I want to know what the environment variable is set for that denotes the language being used in my terminal, I will use the environment variable LANG. Notice that environment variables are capitalized. Once I hit enter, it will print my environment variable. In this case, I'm using English, US English, and it's UTF-8. Now this works for all the individual environment variables, but the question is, is how many are there? Well, to take a look at that, we can just type printenv, take off LANG, hit enter, and it will show all of the environment variables associated with myself as a user within the Bash environment. So for example, we have the login name, we have the type of session we're running, we have the path to our home, our username, here's the LANG command. This information is all about the thematic elements of our terminal. So the question is, is what can we do with these? Well, if I know what the path is and it's listed right here, I can make alterations to that path. If I know the language is UTF-8, I can make changes to that. Once we understand that we have access to these variables, we can incorporate them into our Bash shell scripts. So for example, when I type pwd, it tells me where I'm at. If I would echo, and to check an environment variable, we start with the dollar sign followed by the name of the variable we want to print, and that is pwd. And you'll notice they match. So now that I have access to them, one of the problems we face is making sure that we know enough about the environment variables that we don't harm anything in our system when we change them. For right now, this is just looked at as a type of variable. In our next lesson, we are going to talk about user defined variables. See you then.

Advanced Provider : Jeremy Kurtz 7 Lessons · 44m in Arabic, German, English, Spanish, French, Portuguese, Chinese

Course Description

This course is all about variables, understanding, creating, and modifying variables to enhance interactivity with Linux, which includes learning the variable types, formatting variables, and differentiating the aspects of a shell for variable scoping.

What You'll Learn

Develop a working knowledge of environment and user-defined variables
Identify the different variable types in Linux
Create and modify variables to enhance interactivity with Linux
Accept input and format output
Differentiate variable scoping using local and shared variables across a shell

Key Takeaways

The course covers understanding, creating, and modifying variables to enhance interactivity with Linux.
It distinguishes between environment variables and user-defined variables, including user-defined variable types.
Formatting output and accepting input are part of working with variables in Linux.
Variable scoping is explained in terms of the aspects of a shell, including local and shared variables.

Frequently Asked Questions

What does this course cover?

This course covers understanding, creating, and modifying variables to enhance interactivity with Linux, including variable types, formatting variables, and differentiating the aspects of a shell for variable scoping.

What will I learn about variables?

You will develop a working knowledge of environment and user-defined variables, learn the variable types, and learn to accept input and format output.

What lessons are included?

The course includes Environment Variables, User Defined Variables, User Defined Variable Types, Formatting Output (Parts 1 and 2), and Variable Scoping (Parts 1 and 2).

What skills does this course help build?

It helps build skills in Interactive C, Interactive Programming, Linux Scripting, Local Variables, Shared Variables, and Linux Professional Institute - Linux Essentials.