Interactive Ruby Shell

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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 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.

irb (Interactive Ruby) was developed by Keiju Ishitsuka. It allows you to enter the commands at the prompt and have the interpreter respond as if you were executing a program. irb is a useful way to explore Ruby.

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