ri: Ruby Interactive Reference


ri is an online reference tool developed by Dave Thomas, the famous pragmatic programmer.

When you have a question about the behavior of a certain method, you can invoke ri to read the brief explanation of the method.

You can get ri from ri: Ruby Interactive

Usage Syntax:

Here is simple syntax to use ri

ri [ options ] [ methodname... ]

Here is a complete list of options:

SNCommand with Description

Displays version and exits.
-l n

Sets the line length for the output (minimum is 30 characters).

Displays just a synopsis.
4--format= name
-f name

Uses the name module (default is Plain) for output formatting. Here are the available modules:
  • Tagged: Simple tagged output

  • Plain: Default plain output

name should be specified in any of the following forms:

  • Class

  • Class::method

  • Class#method

  • Class.method

  • method