FreeBSD6 Unleashed

Chapter 10. Shell Programming

IN THIS CHAPTER

• Why Shell Programming Matters to You

• A Simple Shell Program

• Variables

• Interacting with the User

• Arithmetic in Shell Programs

• Loops

• Conditional Statements

• Exit Status

• Functions

• Filehandles

• Debugging Shell Scripts

• Advanced Features of Korn Shell Scripting

In Chapter 8, “Working with the Shell,” you saw how to operate the shell interactively at the command line. To the casual user, the shell looks like nothing more than a prompt where you can type commands and launch bigger, more useful programs. What you may not have realized is that a powerful programming language is built right into the shell, and when you’re at the shell prompt you’re actually in the middle of a “program” that you’re writing line by line with ...