bash Idioms: Write Powerful, Flexible, Readable Shell Scripts

Preface
	Running bash
		bash on Mac
		bash in Containers
	Revision Control
	Hello World
	Conventions Used in This Book
	Using Code Examples
	O’Reilly Online Learning
	How to Contact Us
	Acknowledgments
		bash
		Reviewers
		O’Reilly
		From Carl
		From JP
1. A Big “if” Idiom
	The Big “if”
	Or ELSE…
	More than One
	More than One Again
	Don’t Do This
	Style and Readability: Recap
2. Looping Lingo
	Looping Constructs
	Explicit Values
	Similar to Python
	Quotes and Spaces
	Developing and Testing for Loops
	while and until
	Style and Readability: Recap
3. Just in CASE
	Make Your Case
	A Realistic Use Case
		Motivation
		Our Script
	Wrapper Scripts
	One More Twist
	Style and Readability: Recap
4. Variable Vernacular
	Variable Reference
	Parameter Expansion
		Shorthand for basename
		Path or Prefix Removal
		Shorthand for dirname or Suffix Removal
		Other Modifiers
	Conditional Substitutions
		Default Values
		Comma-Separated Lists
		Modified Value
	$RANDOM
	Command Substitution
	Style and Readability: Recap
5. Expressions and Arithmetic
	Arithmetic
		No Parentheses Needed
	Compound Commands
	Style and Readability: Recap
6. Functional Framework
	Calling Functions
	Defining Functions
		Function Parameters
		Function Return Values
		Local Variables
		Function Special Cases
	Time for printf
		POSIX Output
		Getting or Using the Date and Time
		printf for Reuse or Debugging
	Style and Readability: Recap
7. List and Hash Handling
	Commonalities
	Lists
	Hashes
	A Simple Word Count Example
	Style and Readability: Recap
8. Arguing
	Your First Argument
	Having Options
		Parsing Options
	Long Arguments
	HELP!
	Debug and Verbose
	Version
	Style and Readability: Recap
9. Files and More
	Reading Files
		read
		mapfile
		Brute Force
	Fiddling with $IFS for Fun and Profit, to Read Files
	Pretend Files
	Drop-in Directories
	Using a Library
	Shebang!
	Unofficial bash Strict Mode
	Exit Codes
	It’s a Trap!
	Here-Documents and Here-Strings
	Are We Interactive?
	Summary
10. Beyond Idioms: Working with bash
	Prompts
		bash Time Zone
	Getting User Input
		read
		pause
		select
	Aliases
	Functions
	Local Variables
	Readline Hacks
	Using logger from bash
	Handling JSON with jq
	Grepping the Process List
	Rotating Old Files
	Embedded Documentation
	bash Debugging
	bash Unit Testing
	Summary
11. Developing Your Style Guide
	Readability
	Comments
	Names
	Functions
	Quoting
	Layout
	Syntax
	Other
	Script Template
	Other Style Guides
	bash Linter
	Summary
A. The bash Idioms Style Guide
	Readability
	Comments
	Names
	Functions
	Quoting
	Layout
	Syntax
	Other
	Script Template
Index
About the Authors