ri - Man Page

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.

-i

--[no-]interactive

In interactive mode you can repeatedly look up methods with autocomplete.

-a

--[no-]all

Show all documentation for a class or module.

-l

--[no-]list

List classes ri knows about.

--[no-]pager

Send output to a pager, rather than directly to stdout.

-T

Synonym for --no-pager.

-w WIDTH

--width=WIDTH

Set the width of the output.

--server[=PORT]

Run RDoc server on the given port. The default port is 8214.

-f FORMAT

--format=FORMAT

Use the selected formatter. The default formatter is bs for paged output and ansi otherwise. Valid formatters are: ansi, bs, markdown, rdoc.

-h

--help

Show help and exit.

-v

--version

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.

-d DIRNAME

--doc-dir=DIRNAME

List of directories from which to source documentation in addition to the standard directories. May be repeated.

--no-standard-docs

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.

--dump=CACHE

Dump data from an ri cache or data file.

RI

Options to prepend to those specified on the command-line.

RI_PAGER

PAGER

Pager program to use for displaying.

HOME

USERPROFILE

HOMEPATH

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⟩.

erb(1).