Using variables in shell scripting

Variables sometimes look simple enough—they are there to enable you to put a changing value in your code. The problem is that in this simplicity, there are a couple of things you should know about where you actually place a variable—in something called a context. We are going to deal with that in this chapter.

Getting ready

When we're talking about scripting, things are a little different than they are when we are working in an interactive environment. Every environment variable that is available to you when you use the interactive shell is also available to you in the script. There is, however, one important thing you must always remember. As we said earlier, your script is running in a certain context. This context is defined by the user that has run the script. In a previous chapter, we wanted you to make sure that you have appropriate permissions to do tasks that you need in the script.

In this recipe, we are going...