---
name: "ri"
section: "1"
platform: "linux"
package: "ruby-rdoc"
version: "6.14.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/ri"
---

# ri(1)

Ruby API reference front end

## NAME

**ri** – Ruby API reference front end

## SYNOPSIS

**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**\] \[**--dump**=*CACHE*\] \[*name* *...*\]

## DESCRIPTION

**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

  - ruby: \| ruby:NEWS \| ruby:globals

  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.

## OPTIONS

- **-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.

## ENVIRONMENT

- 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.

## FILES

- *~/.rdoc*

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

## SEE ALSO

[ruby(1)](/ruby/1.md), [rdoc(1)](/rdoc/1.md), [gem(1)](/gem/1.md)

## REPORTING BUGS

- 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.

## AUTHORS

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