Pro Bash Programming (Expert's Voice in Linux) [Paperback]

Chris F. A. Johnson (Author)

Book Description

ISBN-10: 1430219971 | ISBN-13: 978-1430219972 | Publication Date: October 19, 2009 | Edition: 1

This is the only book that treats the shell as a full programming language. It is also the only book that will include bash 4.0 features.

Editorial Reviews

About the Author

Chris F.A. Johnson was introduced to Unix in 1990, and learned shell scripting because there was no C compiler on the system. His first major project was a menu-driven, user-extensible database system with report generator. Chris uses the shell as his primary, general-purpose programming language, and his projects have included a member database, menuing system, and POP3 mail filtering and retrieval. Chris is the author of "Shell Scripting Recipes: A Problem-Solution Approach" (Apress 2005). When not pushing shell scripting to the limit, he designs and codes web sites, teaches chess, and composes cryptic crosswords.

Product Details

• Paperback: 264 pages
• Publisher: Apress; 1 edition (October 19, 2009)
• Language: English
• ISBN-10: 1430219971
• ISBN-13: 978-1430219972
• Product Dimensions: 9.3 x 7.5 x 0.6 inches
• Shipping Weight: 3.2 pounds (View shipping rates and policies)
• Average Customer Review: 4.4 out of 5 stars  See all reviews (8 customer reviews)
• Amazon Best Sellers Rank: #59,713 in Books (See Top 100 in Books)
  • #47 in Books > Computers & Technology > Operating Systems > Linux

More About the Author

After almost 20 years in magazine and newspaper publishing, variously as writer, editor, graphic designer and production manager, I now earn my living composing cryptic crossword puzzles, teaching chess, designing web sites and Unix system administration and programming.

Customer Reviews

Most Helpful Customer Reviews

3 of 3 people found the following review helpful:

5.0 out of 5 stars Not just for beginners, June 29, 2011

By 

Jared Still (Beaverton, OR United States) - See all my reviews
(REAL NAME)   

This review is from: Pro Bash Programming (Expert's Voice in Linux) (Paperback)

I have been looking to update my Kochan and Wood, as it is a bit dated (Hayden Books, 1990).

Over the past couple years I have considered both for sale published works and free online sources for an updated book on shell programming, as Bash has introduced so many new features in the past years.

Though the description states that beginners can use this book, it does progress quickly into more advanced topics.

The positive reviews here and the general excellent quality of Apress books led me to buy this, and I was not disappointed.

In addition to detailing shell features and showing how to use them, Johnson has done something that is not frequently done - he has shown *why* I might want to use a feature.

Chapter 6 for example has excellent explanations of Parameter expansion. Wondering why I might want to use ${VAR:+Alternate} Johnson shows how it is useful. In this case I was able to immediately use it in a script that was being developed, simplifying it greatly.

Kudos for a job well done.

5 of 6 people found the following review helpful:

5.0 out of 5 stars A Good Guide Through the Mysteries of Bash Programming, February 9, 2010

By 

Neil G. Matthews (Adelaide, South Australia) - See all my reviews
(REAL NAME)   

This review is from: Pro Bash Programming (Expert's Voice in Linux) (Paperback)

Considering the critical role Bash has in the installation and operation of Linux distributions and thereby its ubiquity, Bash as a programming language is frequently overlooked by programmers. The author of Pro Bash Programming has done a creditable job in providing the wherewithal for everyone from beginners to expert shell programmers to write more powerful and efficient scripts using Bash, as he takes you through a fast paced coverage of bash's capabilities. Along the way, many useful, well explained and commented practical scripts are provided, many of which can be used to build and test your own scripts. The author claims that while he used to use C when he needed extra speed, that was several years ago and he now does everything in the shell. This book shows how.

The 230 page book is divided into the 15 chapters below, with each chapter ending with a summary of the commands covered and some well chosen exercises.

1 Hello, World! Your first Shell Program
- how to create and run a script and establish good scripting habits
2 Input, Output and Throughput
- echo, printf, read and IO streams
3 Looping and Branching
- tests, conditional execution, looping constructs
4 Command-Line Parsing and Expansion
- quoting, brace, tilde, parameter, variable arithmetic and pathname expansion, command and process substitution, word splitting and parsing with getops
5 Parameters and Variables
- variable scope (essential reading), positional parameters and expansion using patterns, arrays - indexed and associative
6 Shell Functions
- how to define, use and set exit codes, use of compound commands, creation and use of function libraries
7 String Manipulation
- concatenation, processing character by character, case conversion, inserting, overlaying and trimming strings
8 File Operations and Commands
- reading, use of external commands, regular expressions with grep, sed and awk, file name expansion options
9 Reserved Words and Builtin Commands
- good coverage of builtin commands, particularly read (including into arrays) plus a very informative section on how to use builtin commands correctly
10 Writing Bug-Free Scripts and Debugging the Rest
- good scripting programming recommendations for bug free code plus a test and debug example
11 Programming for the Command Line
- manipulating the directory stack, filesystem and miscellaneous functions, managing man pages, games!
12 Runtime Configuration
- command line options and arguments, menus, configuration files, scripts with several names, using environment variables
13 Data Processing
- sorting and searching arrays, various ways of reading arrays into memory, grids (string and two dimensional), data file formats
14 Scripting the Screen
- using the screen as a blackboard or canvas, rendition modes and colours, text scrolling - rolling dice example
15 Entry-Level Programming
- single key entry, use of author's key-funcs library, sanity checking, form entry, reading the mouse!

Appendix: Shell Variables
- alphabetic listing of (1) variables set by bash and (2) variables used by bash

One of the strengths of this book is that the author explains the fastest way to accomplish many standard programming tasks through the appropriate choice of one of the many different bash methods available, including the choice between builtin bash commands and external commands. I found chapter 9 particularly interesting here. Chapter 7 shows how effective bash is at string manipulation with the right techniques - amazing! While the book covers bash 4.0 and often uses non POSIX extensions, those unable to use bash 4.0 or constrained to POSIX compliant code are not forgotten, with the author providing alternatives that work within these constraints.

Where a subject is introduced in an early chapter and expanded on later, the author thoughtfully provides the forward reference. Source code for the included scripts is available from the publisher's webpage for this book at [...]

The 10 page index works reasonably well, but you may find it worthwhile grabbing the companion eBook so you can directly search through the book to make the best use of it as a reference source. If you buy the dead tree version, the eBook is available on-line for $10 until April 2010 direct from the publisher.

I can recommend this book to anyone that can benefit from automating repetitive shell based tasks in Linux but isn't sure how best to go about it. The included scripts and wealth of tips on how to avoid common bash coding problems will provide you with a quick return on your investment.


Neil Matthews

2 of 2 people found the following review helpful:

5.0 out of 5 stars A word from the technical reviewer, August 1, 2011

By 

Edward L. Schaefer - See all my reviews
(REAL NAME)   

Amazon Verified Purchase

This review is from: Pro Bash Programming (Expert's Voice in Linux) (Paperback)

Full disclosure: I was the technical reviewer for this book, and I admit my opinion may be biased. However, I was a just technical mercenary hired by the publisher so there is no financial benefit to me if the book does well or not.

Is author Chris F. A. Johnson pushing an agenda? You bet he is and that is a good thing. His agenda isn't hidden; he succinctly states it in the introduction:

"While most shell programs do call external utilities, a lot of programming can be done entirely in the shell. Many scripts call just one or two utilities for information that is used later in the script. Some scripts are little more than wrappers for other commands such as awk, grep, or sed. This book is about programming in the shell itself. There's a sprinkling of the second type, where the script gets information (such as the current date and time) and then processes it. The third type gets barely more than a cursory nod."

Resist the urge to call awk, grep, sed, perl or another Linux tool first; this book teaches the Bash shell's prgramming capabilities. Why call an external program when the shell can do the work for you?

Should this be your first Bash programming book? Not if you require lots of syntactic hand holding. But if a motivated and clever beginner masters the first 10 chapters of this book, that beginner is on their way to becoming an expert. You will learn how to create functions, deal with files, parse strings, etc - correctly!

There might also be something here for the expert. I've been creating *nix shell scripts for a long time, and I admit to being set in my programming ways. After reviewing this book, I changed the way I now parse and manipulate strings.