Bash Guide for Beginners
Douban
Machtelt Garrels
Overview
The primary reason for writing this document is that a lot of readers feel the existing HOWTO to be too short and incomplete, while the Bash Scripting guide is too much of a reference work. There is nothing in between these two extremes. I also wrote this guide on the general principal that not enough free basic courses are available, though they should be.
This is a practical guide which, while not always being too serious, tries to give real-life instead of theoretical examples. I partly wrote it because I don't get excited with stripped down and over-simplified examples written by people who know what they are talking about, showing some really cool Bash feature so much out of its context that you cannot ever use it in practical circumstances. You can read that sort of stuff after finishing this book, which contains exercises and examples that will help you survive in the real world.
From my experience as UNIX/Linux user, system administrator and trainer, I know that people can have years of daily interaction with their systems, without having the slightest knowledge of task automation. Thus they often think that UNIX is not userfriendly, and even worse, they get the impression that it is slow and old-fashioned. This problem is another one that can be remedied by this guide.
contents
Introduction
1. Why this guide?
2. Who should read this book?
3. New versions, translations and availability
4. Revision History
5. Contributions
6. Feedback
7. Copyright information
8. What do you need?
9. Conventions used in this document
10. Organization of this document
1. Bash and Bash scripts
1.1. Common shell programs
1.2. Advantages of the Bourne Again SHell
1.3. Executing commands
1.4. Building blocks
1.5. Developing good scripts
1.6. Summary
1.7. Exercises
2. Writing and debugging scripts
2.1. Creating and running a script
2.2. Script basics
2.3. Debugging Bash scripts
2.4. Summary
2.5. Exercises
3. The Bash environment
3.1. Shell initialization files
3.2. Variables
3.3. Quoting characters
3.4. Shell expansion
3.5. Aliases
3.6. More Bash options
3.7. Summary
3.8. Exercises
4. Regular expressions
4.1. Regular expressions
4.2. Examples using grep
4.3. Pattern matching using Bash features
4.4. Summary
4.5. Exercises
5. The GNU sed stream editor
5.1. Introduction
5.2. Interactive editing
5.3. Non-interactive editing
5.4. Summary
5.5. Exercises
6. The GNU awk programming language
6.1. Getting started with gawk
6.2. The print program
6.3. Gawk variables
6.4. Summary
6.5. Exercises
7. Conditional statements
7.1. Introduction to if
7.2. More advanced if usage
7.3. Using case statements
7.4. Summary
7.5. Exercises
8. Writing interactive scripts
8.1. Displaying user messages
8.2. Catching user input
8.3. Summary
8.4. Exercises
9. Repetitive tasks
9.1. The for loop
9.2. The while loop
9.3. The until loop
9.4. I/O redirection and loops
9.5. Break and continue
9.6. Making menus with the select built-in
9.7. The shift built-in
9.8. Summary
9.9. Exercises
10. More on variables
10.1. Types of variables
10.2. Array variables
10.3. Operations on variables
10.4. Summary
10.5. Exercises
11. Functions
11.1. Introduction
11.2. Examples of functions in scripts
11.3. Summary
11.4. Exercises
12. Catching signals
12.1. Signals
12.2. Traps
12.3. Summary
12.4. Exercises
A. Shell Features
A.1. Common features
A.2. Differing features
Glossary
Index
