Pro Bash : Learn to Script and Program the GNU/Linux Shell

Front Matter Pages i-xxi Hello, World: Your First Shell Program Pages 1-9 Input, Output, and Throughput Pages 11-26 Looping and Branching Pages 27-40 Command-Line Parsing and Expansion Pages 41-59 Parameters and Variables Pages 61-83 Shell Functions Pages 85-96 String Manipulation Pages 97-114 File Operations and Commands Pages 115-137 Reserved Words and Built-In Commands Pages 139-158 Writing Bug-Free Scripts and Debugging the Rest Pages 159-174 Programming for the Command Line Pages 175-195 Runtime Configuration Pages 197-217 Data Processing Pages 219-247 Scripting the Screen Pages 249-263 Entry-Level Programming Pages 265-283 Back Matter Pages 285-305 Learn how to effectively utilize the Bash shell in your programming. This refreshed and expanded third edition has been updated to Bash 5.2, and many scripts have been rewritten to make them more idiomatically Bash, taking better advantage of features specific to Bash. It is easy to read, understand, and will teach you how to get to grips with Bash programming without drowning you in pages and pages of syntax. Using this book you will be able to use the shell efficiently, make scripts run faster using expansion and external commands, and understand how to overcome many common mistakes that cause scripts to fail. This book is perfect for all beginning Linux and Unix system administrators who want to be in full control of their systems, and really get to grips with Bash programming. 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 programs through standard programming techniques. What You'll Learn Use the Bash shell to write utilities and accomplish most programming tasks Replace many external commands with shell parameter expansion making scripts very fast Avoid many common mistakes that cause scripts to fail See how Bash’s read line and history libraries can save typing when getting user input Build shell scripts that get information from the Web Who This Book Is For Developers, programmers, and open source enthusiasts who want to write scripts using Bash on multiple platforms