FreeBSD® Unleashed

Chapter 13. Shell Programming

In This Chapter

• A Simple Shell Program

• Variables

• Interaction with the User

• Arithmetic in Shell Programs

• Loops

• Conditional Statements

• Exit Status

• Functions

• File Descriptors

• Debugging Shell Scripts

• Advanced Features of Korn Shell Scripting

In Chapter 8, “Working with the Shell,” you saw how to work with the shell interactively at the command line. What you may not have known is that there is a powerful programming language built into the shell. You can use shell programming to do everything from automating a repetitive list of commands, to writing sophisticated interactive programs that process text data, to storing and retrieving information in simple databases.

Due to the modular design of the FreeBSD operating system, you ...