Programming Ruby 1.9 & 2.0: The Pragmatic Programmers’ Guide (2013)
Part 1. Facets of Ruby
Chapter 3. Classes, Objects, and Variables
Chapter 4. Containers, Blocks, and Iterators
Chapter 5. Sharing Functionality: Inheritance, Modules, and Mixins
Chapter 7. Regular Expressions
Chapter 10. Exceptions, catch, and throw
Chapter 11. Basic Input and Output
Chapter 12. Fibers, Threads, and Processes
Chapter 14. When Trouble Strikes!
Part 2. Ruby in Its Setting
Chapter 15. Ruby and Its World
Chapter 16. Namespaces, Source Files, and Distribution
Chapter 17. Character Encoding
Chapter 18. Interactive Ruby Shell
Chapter 21. Ruby and Microsoft Windows
Part 3. Ruby Crystallized
Chapter 25. Reflection, ObjectSpace, and Distributed Ruby
Chapter 26. Locking Ruby in the Safe
Part 4. Ruby Library Reference
Chapter 27. Built-in Classes and Modules