The bash shell is a complete programming language, not merely a glue to combine external Linux commands. By taking full advantage of shell internals, shell programs can perform as snappily as utilities written in C or other compiled languages. And you will see how, without assuming Unix lore, you can write professional bash 4.0 programs through standard programming techniques.

• Complete bash coverage
• Teaches bash as a programming language
• Helps you master bash 4.0 features

What you’ll learn

• Use the shell to write new utilities and accomplish most programming tasks.
• Use shell parameter expansion to replace many external commands, making scripts very fast.
• Learn to avoid many common mistakes that cause scripts to fail.
• Learn how bash’s readline and history libraries can save typing when getting user input.
• Learn to use features new to bash 4.0.
• Build shell scripts that get information from the Web.

Who this book is for

Beginning Linux and Unix system administrators who want to be in full command of their systems.

Table of Contents

1. Hello, World! Your First Shell Program
2. Input, Output, and Throughput
3. Looping and Branching
4. Command-Line Parsing and Expansion
5. Parameters and Variables
6. Shell Functions
7. String Manipulation
8. File Operations and Commands
9. Reserved Words and Builtin Commands
10. Writing Bug-Free Scripts and Debugging the Rest
11. Programming for the Command Line
12. Runtime Configuration
13. Data Processing
14. Scripting the Screen
15. Entry-Level Programming