Interactive Ruby Shell

Interactive Ruby Shell (irb) is a shell for programming in the object-oriented scripting language Ruby. irb is run from the command line and allows the programmer to experiment with code in real time. It allows you to enter Ruby commands at the prompt and have the interpreter respond immediately. It features command-line history, line editing capabilities, and job control, and is able to communicate directly as a shell script over the Internet and interact with a live server. It was developed by Keiju Ishitsuka.

Program usage:

irb [ options ] [ programfile ] [ argument... ]

Example usage:

irb(main):001:0> n = 5
=> 5
irb(main):002:0> def fact(n)
irb(main):003:1>   if n <= 1
irb(main):004:2>     1
irb(main):005:2>   else
irb(main):006:2*     n * fact(n - 1)
irb(main):007:2>   end
irb(main):008:1> end
=> nil
irb(main):009:0> fact(n)
=> 120

External links

• "When Trouble Strikes" chapter from Programming Ruby
• "Interactive Ruby Shell" chapter from Programming Ruby
• Try Ruby!—An interactive tutorial and Ruby shell within your browser.