Pro Bash Programming: Scripting the GNU/Linux Shell, Second Edition (2015)
CHAPTER 1. Hello, World: Your First Shell Program
CHAPTER 2. Input, Output, and Throughput
CHAPTER 3. Looping and Branching
CHAPTER 4. Command-Line Parsing and Expansion
CHAPTER 5. Parameters and Variables
CHAPTER 7. String Manipulation
CHAPTER 8. File Operations and Commands
CHAPTER 9. Reserved Words and Built-In Commands
CHAPTER 10. Writing Bug-Free Scripts and Debugging the Rest
CHAPTER 11. Programming for the Command Line
CHAPTER 12. Runtime Configuration
CHAPTER 14. Scripting the Screen
CHAPTER 15. Entry-Level Programming