RI(1) 1 (ruby programmer's reference guide) RI(1)

riRuby API reference front end

ri [-ahilTv] [-d DIRNAME] [-f FORMAT] [-w WIDTH] [--[no-]pager] [--server[=PORT]] [--[no-]list-doc-dirs] [--no-standard-docs] [--[no-]{system|site|gems|home}] [--[no-]profile] [--dump=CACHE] [name ...]

ri is a command-line front end for the Ruby API reference. You can search and read the API reference for classes and methods with ri.

ri is a part of Ruby.

name can be:

Class | Module | Module::Class
Class::method | Class#method | Class.method | method
gem_name: | gem_name:README | gem_name:History

All class names may be abbreviated to their minimum unambiguous form. If a name is ambiguous, all valid options will be listed.

A ‘.’ matches either class or instance methods, while #method matches only instance and ::method matches only class methods.

README and other files may be displayed by prefixing them with the gem name they're contained in. If the gem name is followed by a ‘:’ all files in the gem will be shown. The file name extension may be omitted where it is unambiguous.

For example:

ri Fil
ri File
ri File.new
ri zip
ri rdoc:README

Note that shell quoting or escaping may be required for method names containing punctuation:

ri 'Array.[]'
ri compact\!

To see the default directories ri will search, run:

ri --list-doc-dirs

Specifying the --system, --site, --home, --gems, or --doc-dir options will limit ri to searching only the specified directories.

ri options may be set in the RI environment variable.

The ri pager can be set with the RI_PAGER environment variable or the PAGER environment variable.

 
--[no-]interactive
In interactive mode you can repeatedly look up methods with autocomplete.
 
--[no-]all
Show all documentation for a class or module.
 
--[no-]list
List classes ri knows about.
--[no-]pager
Send output to a pager, rather than directly to stdout.
Synonym for --no-pager.
WIDTH
 
=WIDTH
Set the width of the output.
[=PORT]
Run RDoc server on the given port. The default port is 8214.
FORMAT
 
=FORMAT
Use the selected formatter. The default formatter is bs for paged output and ansi otherwise. Valid formatters are: ansi, bs, markdown, rdoc.
 
Show help and exit.
 
Output version information and exit.

Data source options:

--[no-]list-doc-dirs
List the directories from which ri will source documentation on stdout and exit.
DIRNAME
 
=DIRNAME
List of directories from which to source documentation in addition to the standard directories. May be repeated.
Do not include documentation from the Ruby standard library, site_lib, installed gems, or ~/.rdoc. Use with --doc-dir.
--[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 true.

Debug options:

--[no-]profile
Run with the Ruby profiler.
=CACHE
Dump data from an ri cache or data file.

Options to prepend to those specified on the command-line.
 
Pager program to use for displaying.
 
 
Path to the user's home directory.

~/.rdoc
Path for ri data in the user's home directory.

ruby(1), rdoc(1), gem(1)

  • Security vulnerabilities should be reported via an email to security@ruby-lang.org. Reported problems will be published after being fixed.
  • Other bugs and feature requests can be reported via the Ruby Issue Tracking System (https://bugs.ruby-lang.org/). Do not report security vulnerabilities via this system because it publishes the vulnerabilities immediately.

Written by Dave Thomas ⟨dave@pragmaticprogrammer.com⟩.

April 20, 2017 UNIX