RI(1) Ruby Programmers Reference Guide RI(1)
ri -- Ruby API reference front end
ri [-Ti] [-d directory] [-f format] [--list-doc-dirs]
[--[no-]use-cache] [--width=width] [target ...]
ri is a CLI front end for the Ruby API reference. You can search and
read API reference for classes and methods with ri.
ri is a part of Ruby.
target can be one of the following forms:
Class for classes
Class::method for class methods
Class#method for instance methods
Class.method for both class and instance methods
method for both class and instance methods
All class names may be abbreviated to their minimum unambiguous form. If
a name is ambiguous, all valid options will be listed.
Note that shell quoting may be required for method names containing punc-
--version Prints the version of ri.
--no-pager Send output directly to stdout, rather than to a pager.
List of directories from which to source documentation in
addition to the standard directories. May be repeated.
Format to use when displaying output:
ansi, bs, html, plain, simple
Use 'bs' (backspace) with most pager programs. To use
ANSI, either disable the pager or tell the pager to allow
--interactive This makes ri go into interactive mode.
When ri is in interactive mode it will allow the user to
disambiguate lists of methods in case multiple methods
match against a method search string. It also will allow
the user to enter in a method name (with auto-completion,
if readline is supported) when viewing a class.
List the directories from which ri will source documenta-
tion on stdout and exit.
Do not include documentation from the Ruby standard
library, site_lib, installed gems, or ~/.rdoc.
Equivalent to specifying the options --no-system,
--no-site, --no-gems, and --no-home.
--[no-]system Include documentation from Ruby's standard library.
Defaults to true.
--[no-]site Include documentation from libraries installed in
site_lib. Defaults to true.
--[no-]gems Include documentation from RubyGems. Defaults to true.
--[no-]home Include documentation stored in ~/.rdoc. Defaults to
Whether or not to use ri's cache. True by default.
--width=width Set the width of the output.
RI Additional options.
PAGER Used as the name of pager program for displaying.
HOMEPATH Path to user's home directory.
~/.ri Caches recently referenced documents here.
~/.rdoc Searches user-wide documents here.
Security vulnerabilities should be reported via an email to
<firstname.lastname@example.org>. Reported problems will be published after
And you can report other bugs and feature requests via the Ruby Issue
Tracking System (http://bugs.ruby-lang.org). Do not report security vul-
nerabilities via the system because it publishes the vulnerabilities
Written by Dave Thomas <email@example.com>
UNIX November 7, 2012 UNIX