Summary

In this lesson, we looked at how to modify your user environment and what is needed to customize it. Although we skimmed only the surface, you should feel comfortable enough to make some configuration changes on your system. You are also advised to practice these on a system where harmful changes won't cause too much of a problem. Use a lab whenever you can.

The following was covered in this lesson:

• Environment variables are always uppercase, and preceded by $. This is how they are identified as variables.

• Environment variables are frequently used for specifying single configuration options to a program, such as providing a pointer to a directory that the program needs.

• The $PATH variable keeps track of where the system searches for commands when you type them. If a command exists on the system, but the path to the command is not in your $PATH variable, it will not be found when you type the command name.

• Aliases are a very powerful feature of Unix shells. They enable you to rename commands, or cause commands to always use certain options when you issue them.

• Dot files are everywhere. Many programs use text files containing configuration information for control purposes. These files almost universally have filenames, which start with a . character. They are the place to look for automating settings to your shell, and for configuring options for the windowing system.