Ruby Cookbook

Recipe 21.1. Resources HighLine, written by James Edward Gray II and Gregory Brown, is available as the highline gem. The Curses and Readline libraries come preinstalled with Ruby (even on Windows, if you use the one-click installer). If...

Recipe 21.2. Getting Input One Line at a Time Problem You're writing an interactive console program, and you want to get line-based input from the user. You present the user with a prompt, and he types some data before hitting enter. So...

Recipe 21.3. Getting Input One Character at a Time Problem You're writing an interactive application or a terminal-based game. You want to read a user's input from standard input a single character at a time. Solution Most Ruby in...

Recipe 21.4. Parsing Command-Line Arguments Problem You want to make your Ruby script take command-line arguments, the way most Unix utilities and scripts do. Solution If you want to treat your command-line arguments as a simpl...

Recipe 21.5. Testing Whether a Program Is Running Interactively Problem You want to see whether there's another person on the other end of your program, or whether the program has been hooked up to a file or the output of another prog...

Recipe 21.6. Setting Up and Tearing Down a Curses Program Problem To write a program that uses Curses or Ncurses, you have to write a lot of setup and cleanup code. You'd like to factor that out. Solution Here's a wrapper method tha...

Recipe 21.7. Clearing the Screen Problem You're writing a console application, and you want it to clear the screen. Solution Capture the output of the Unix clear command as a string and print it whenever you want to clear the sc...

Recipe 21.8. Determining Terminal Size Problem Within a terminal-based application, you want to find the size of the terminal: how many rows and columns are available for you to draw on. Solution This is easy if you're using the Curs...

Recipe 21.9. Changing Text Color Problem You want to display multicolored text on the console. Solution The simplest solution is to use HighLine. It lets you enclose color commands in an ERb template that gets interpreted withi...

Recipe 21.10. Reading a Password Problem You want to prompt the user for a password, or otherwise capture input without echoing it to the screen for all to see. Solution The ruby-password library makes this easy, but it's not avai...

Recipe 21.11. Allowing Input Editing with Readline Problem You want to let your users edit their lines of input as they write them, the way irb does. Solution Use the readline library. Instead of reading directly from standar...

Recipe 21.12. Making Your Keyboard Lights Blink Problem You want to control the three standard keyboard LEDs (num lock, caps lock, and scroll lock) from a Ruby script. Solution Use the Blinkenlights library, available as the blinkenl...

Recipe 21.13. Creating a GUI Application with Tk Credit: Kevin Marshall Problem You need to create a program that has a graphical user interface (GUI). Solution Use the Tk library. It's language-independent, cross-platform, and b...

Recipe 21.14. Creating a GUI Application with wxRuby Problem You want to write a portable GUI application that looks better than a Tk application. Solution Use the wxRuby library, available as a third-party download. It uses nativ...

Recipe 21.15. Creating a GUI Application with Ruby/GTK Problem You want to write a GUI application that uses the GTK widget library, perhaps so you can integrate it with the Gnome desktop environment. Solution Use the Ruby bindings to ...

Recipe 21.16. Creating a Mac OS X Application with RubyCocoa Credit: Alun ap Rhisiart Problem You want to create a native Mac OS X program with a graphical user interface. Solution Use the Mac OS X Cocoa library along with Ruby...