IRB(1) Ruby Programmer's Reference Guide IRB(1)
NAME
irb — Interactive Ruby Shell
SYNOPSIS
irb [--version] [-dfUw] [-I directory] [-r library]
[-E external[:internal]] [-W[level]] [--[no]inspect]
[--[no]multiline] [--[no]singleline] [--[no]echo] [--[no]colorize]
[--[no]autocomplete] [--[no]verbose] [--prompt mode]
[--prompt-mode mode] [--inf-ruby-mode] [--simple-prompt]
[--noprompt] [--tracer] [--back-trace-limit n] [--] [program_file]
[argument ...]
DESCRIPTION
irb is the REPL(read-eval-print loop) environment for Ruby programs.
OPTIONS
--version Prints the version of irb.
-E external[:internal]
--encoding external[:internal]
Same as `ruby -E' . Specifies the default value(s) for
external encodings and internal encoding. Values should
be separated with colon (:).
You can omit the one for internal encodings, then the
value (Encoding.default_internal) will be nil.
-I path Same as `ruby -I' . Specifies $LOAD_PATH directory
-U Same as `ruby -U' . Sets the default value for internal
encodings (Encoding.default_internal) to UTF-8.
-d Same as `ruby -d' . Sets $DEBUG to true.
-f Suppresses read of ~/.irbrc.
-w Same as `ruby -w' .
-W Same as `ruby -W' .
-h
--help Prints a summary of the options.
-r library Same as `ruby -r'. Causes irb to load the library using
require.
--inspect Uses `inspect' for output (default except for bc mode)
--noinspect Doesn't use inspect for output
--multiline Uses multiline editor module.
--nomultiline Doesn't use multiline editor module.
--singleline Uses singleline editor module.
--nosingleline
Doesn't use singleline editor module.
--extra-doc-dir
Add an extra doc dir for the doc dialog.
--echo Show result (default).
--noecho Don't show result.
--echo-on-assignment
Show result on assignment.
--noecho-on-assignment
Don't show result on assignment.
--truncate-echo-on-assignment
Show truncated result on assignment (default).
--colorize Use colorization.
--nocolorize Don't use colorization.
--autocomplete
Use autocompletion.
--noautocomplete
Don't use autocompletion.
--regexp-completor
Use regexp based completion.
--type-completor
Use type based completion.
--verbose Show details.
--noverbose Don't show details.
--prompt mode
--prompt-mode mode
Switch prompt mode. Pre-defined prompt modes are `de-
fault', `simple', `xmp' and `inf-ruby'.
--inf-ruby-mode
Uses prompt appropriate for inf-ruby-mode on emacs. Sup-
presses --multiline and --singleline.
--simple-prompt
Makes prompts simple.
--noprompt No prompt mode.
--tracer Displays trace for each execution of commands.
--back-trace-limit n
Displays backtrace top n and tail n. The default value
is 16.
ENVIRONMENT
IRB_LANG The locale used for irb.
IRBRC The path to the personal initialization file.
XDG_CONFIG_HOME irb respects XDG_CONFIG_HOME. If this is set, load
$XDG_CONFIG_HOME/irb/irbrc as a personal initialization
file.
Also irb depends on same variables as ruby(1).
FILES
~/.irbrc
Personal irb initialization. If IRBRC is set, read $IRBRC in-
stead. If IRBRC is not set and XDG_CONFIG_HOME is set,
$XDG_CONFIG_HOME/irb/irbrc is loaded.
EXAMPLES
% irb
irb(main):001:0> 1 + 1
2
irb(main):002:0> def t(x)
irb(main):003:1> x + 1
irb(main):004:1> end
=> :t
irb(main):005:0> t(3)
=> 4
irb(main):006:0> if t(3) == 4
irb(main):007:1> p :ok
irb(main):008:1> end
:ok
=> :ok
irb(main):009:0> quit
%
SEE ALSO
ruby(1).
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 secu-
rity vulnerabilities via this system because it publishes the vul-
nerabilities immediately.
AUTHORS
Written by Keiju ISHITSUKA.
UNIX August 11, 2019 IRB(1)
Generated by dwww version 1.16 on Fri Dec 5 09:16:05 CET 2025.