Whenever you start a bash shell, several different variables are used to define critical parameters the shell needs to run properly. Because these variables define the shell environment, they are called environment variables. In this part of this chapter, we’re going to spend some time learning about environment variables. Specifically, we’re going to cover the following topics:
• What environment variables are
• Managing environment variables
• Creating user-defined variables
Let’s begin by reviewing what environment variables are.
Before you can understand what an environment variable is, you must first understand what a variable itself is. The best way to describe variables ...