Ruby Cookbook

Chapter 1. Strings Ruby is a programmer-friendly language. If you are already familiar with object oriented programming, Ruby should quickly become second nature. If you've struggled with learning object-oriented programming or are not fa...

Chapter 2. Numbers Numbers are as fundamental to computing as breath is to human life. Even programs that have nothing to do with math need to count the items in a data structure, display average running times, or use numbers as a source...

Chapter 3. Date and Time With no concept of time, our lives would be a mess. Without software programs to constantly manage and record this bizarre aspect of our universe#8230;well, we might actually be better off. But why take the r...

Chapter 4. Arrays Like all high-level languages, Ruby has built-in support for arrays, objects that contain ordered lists of other objects. You can use arrays (often in conjunction with hashes) to build and use complex data structu...

Chapter 5. Hashes Hashes and arrays are the two basic "aggregate" data types supported by most modern programming lagnguages. The basic interface of a hash is similar to that of an array. The difference is that while an array stores items...

Chapter 6. Files and Directories As programming languages increase in power, we programmers get further and further from the details of the underlying machine language. When it comes to the operating system, though, even the most modern p...

Chapter 7. Code Blocks and Iteration In Ruby, a code block (or just "block") is an object that contains some Ruby code, and the context neccesary to execute it. Code blocks are the most visually distinctive aspect of Ruby, and also one...

Chapter 8. Objects and Classes8 Ruby is an object-oriented programming language; this chapter will show you what that really means. Like all modern languages, Ruby supports object-oriented notions like classes, inheiritance, and polymorph...

Chapter 9. Modules and Namespaces A Ruby module is nothing more than a grouping of objects under a single name. The objects may be constants, methods, classes, or other modules. Modules have two uses. You can use a module as a convenien...

Chapter 10. Reflection and Metaprogramming In a dynamic language like Ruby, few pieces are static. Classes can grow new methods and lose the ones they had before. Methods can be defined manually, or automatically with well-written c...

Chapter 11. XML and HTML XML and HTML are the most popular markup languages (textual ways of describing structured data). HTML is used to describe textual documents, like you see on the Web. XML is used for just about everything else: dat...

Chapter 12. Graphics and Other File Formats Hundreds of standards exist for storing structured data in text or binary files. Some of these are so popular that we've devoted entire chapters to them (Chapters 11 and 13). Some are so simple...

Chapter 13. Databases and Persistence We all want to leave behind something that will outlast us, and Ruby processes are no exception. Every program you write leaves some record of its activity, even if it's just data written to standard...

Chapter 14. Internet Services Network programming is hard. The C socket library is the standard way of writing Internet clients and servers. It's like the file API descibed in Chapter 6, with its special flags and meager abstraction, on...

Chapter 15. Web Development: Ruby on Rails Ruby on Rails is unquestionably Ruby's killer app. It can take a lot of credit for lifting Ruby from obscurity outside its native Japan. No other programming language can boast a simple web appli...

Chapter 16. Web Services and Distributed Programming Distributed programming is like network programmingonly the audience is different. The point of network programming is to let a human control a computer across the network. The point...

Chapter 17. Testing, Debugging, Optimizing, and Documenting The recipes in previous chapters focus on writing code to do what you want. This chapter focuses on verifying that your code really works, and on fixing it when it breaks. We sta...

Chapter 18. Packaging and Distributing Software No matter how productive it makes you, a programming language won't save you any time if you can't take advantage of a body of code written by other people. A community works faster than...

Chapter 19. Automating Tasks with Rake Even when your software is written, tested, and packaged, you're still not done. You've got to start working on the next version, and the next#8230; Every release you do, in some cases every chang...

Chapter 20. Multitasking and Multithreading You can't concentrate on more than What's six times nine? one thing at once. You won't get very far reading this book if someone is interrupting you every five seconds asking you to do ari...

Chapter 21. User Interface Ruby has libraries for attaching programs to the three main types of user interface. The web interface, Ruby's most popular, is covered in depth in Chapters 15, 16, and (to a lesser extent) 14. This chapter cove...

Chapter 22. Extending Ruby with Other Languages When you decide to use an interpreted language such as Ruby, you're trading raw speed for ease of use. It's far easier to develop a program in a higher-level language, and you get a working...

Chapter 23. System Administration Once you start using Ruby, you'll want to use it everywhere. Well, nothing's stopping you. This chapter shows you how to use Ruby in command-line programs that solve general everyday problems. It also dem...