Interactive Ruby Shell

Interactive Ruby Shell (IRB or irb) is a REPL for programming in the object-oriented scripting language Ruby. The abbreviation irb is a portmanteau of the word "interactive" and the filename extension for Ruby files, ".rb".

Interactive Ruby Shell

Screenshot The screenshot session as same as the article example
Developer(s)	Keiju Ishitsuka
Stable release	1.2.4 / May 2, 2020 (2020-05-02)[1]
Repository	github.com/ruby/irb
Written in	Ruby
Operating system	Cross-platform
Platform	Ruby interpreter
Type	Ruby shell
License	Ruby License BSD License
Website	www.ruby-lang.org/en/

The program is launched from a command line and allows the execution of Ruby commands with immediate response, experimenting in real-time. It features command 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.

Syntax and use

Syntax:

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

Example:

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
=> :fact
irb(main):009:0> fact(n)
=> 120

irb(main):001:0> class Cat
irb(main):002:1>   def meow
irb(main):003:2>     puts 'The cat meows.'
irb(main):004:2>   end
irb(main):005:1> end
=> :meow

irb(main):006:0> Cat.new.meow
The cat meows.

See also

• Comparison of computer shells

References

1. "All versions of irb". RubyGems.org. Retrieved 2020-07-06.

External links

• "Code and run Ruby online" A powerful interactive Ruby shell
• "Try Ruby" Online IRB
• "When Trouble Strikes" chapter from Programming Ruby
• "Interactive Ruby Shell" chapter from Programming Ruby