Pro Bash Programming, Second Edition [electronic resource] :  Scripting the GNU/Linux Shell /
Johnson, Chris.author.
Varma, Jayant.author.
Pro Bash Programming teaches you how to effectively utilize the Bash shell in your 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 4.3 programs through standard programming techniques. This second edition has updated for Bash 4.3, 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.
"User level: beginning-advanced"--Page 4 of cover.
Contents at a Glance; Chapter 1: Hello, World: Your First Shell Program;  The Code;  The File;  The Naming of Scripts;  Selecting a Directory for the Script;  Creating the File and Running the Script;  Choosing and Using a Text Editor;  Building a Better "Hello, World!";  Summary;  Commands ;  Concepts ;  Variables ;  Exercises; Chapter 2: Input, Output, and Throughput;  Parameter and Variables;  Positional Parameters;  Special *@#0?_!- Parameters;  Variables ;  Arguments and Options ;  echo, and Why You Should Avoid It;  printf: Formatting and Printing Data;  Escape Sequences
break continue;  Summary;  Commands;  Concepts;  Exercises; Chapter 4: Command-Line Parsing and Expansion;  Quoting;  Brace Expansion;  Tilde Expansion;  Parameter and Variable Expansion;  Arithmetic Expansion;  Command Substitution;  Word Splitting;  Pathname Expansion;  Process Substitution;  Parsing Options;  Summary;  Commands;  Exercises; Chapter 5: Parameters and Variables;  The Naming of Variables;  The Scope of a Variable: Can You See It from Here?;  Shell Variables;  Parameter Expansion;  Bourne Shell; {var:-default} and {var-default}: Use Default Values
{var:+alternate}, {var+alternate}: Use Alternate Values {var:=default}, {var=default}: Assign Default Values ; {var:?message}, {var?message}: Display Error Message If Empty or Unset;  POSIX Shell; {#var}: Length of Variable's Contents ; {var%PATTERN}: Remove the Shortest Match from the End; {var%%PATTERN}: Remove the Longest Match from the End; {var#PATTERN}: Remove the Shortest Match from the Beginning; {var##PATTERN}: Remove the Longest Match from the Beginning;  Bash; {var//PATTERN/STRING}: Replace All Instances of PATTERN with STRING
{var:OFFSET:LENGTH}: Return a Substring of var{!var}: Indirect Reference;  Bash-4.0; Sec21; {var^PATTERN}: Convert to Uppercase ; {var,PATTERN}: Convert to Lowercase ;  Positional Parameters;  Arrays;  Integer-Indexed Arrays ; Sec27; Displaying Arrays;  Assigning Array Elements;  Associative Arrays ;  Summary;  Commands;  Concepts; Chapter 6: Shell Functions;  Definition Syntax;  Compound Commands;  Getting Results;  Set Different Exit Codes;  Print the Result;  Place Results in One or More Variables;  Function Libraries;  Using Functions from Libraries;  Sample Script;  Summary
Commands
Includes index.
Pro Bash Programming teaches you how to effectively utilize the Bash shell in your 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 4.3 programs through standard programming techniques. This second edition has updated for Bash 4.3, 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.
"User level: beginning-advanced"--Page 4 of cover.
UNIX Shells.
UNIX (Computer file)
UNIX (Computer file)
UNIX Shells.
Open source software.
Computer programming.
Software engineering.
Open Source.
Software Engineering/Programming and Operating Systems.