Chapter 17. Shells, Scripting, Programming, and Compiling (Topic 1.9)

Depending upon the computing environments you're used to, the concepts of shells and shell programs (usually called scripts) may be a little foreign. In the Windows world, for example, native scripting capabilities are limited to the command interpreter's simple batch command language. This facility has only the most primitive automation capabilities, and many extensions and alternatives have appeared on the market to fill the void. If you've used an AS/400 system, you had similar limitations for scripting. On Linux systems, shells and their scripting languages are fundamental concepts used throughout the system and they have widely ranging capabilities.

This chapter covers Shells, Scripting, Programming, and Compiling and its two Objectives:

Objective 1: Customize and Use the Shell Environment

This Objective covers your shell and basic scripting concepts, including environment variables, functions, and script files that control the login environment. Weight: 4.

Objective 2: Customize or Write Simple Scripts

Customization of the many scripts found on a Linux system is important for its management and automation. Topics for this Objective include shell syntax, checking the status of executed programs, and issues surrounding the properties of script files. Weight: 5.

It is important for Linux administrators to become comfortable with at least one shell and its programming language. This can be an area of some concern to those used to graphics-only environments, where the use of a command interpreter is not a daily activity. As you'll see, becoming adept at working with your favorite shell will empower you and will allow you to let your computer carry a larger share of your daily responsibilities.