NAME

irb — Interactive Ruby Shell

SYNOPSIS

irb [--version] [-dfm] [-I directory] [-r library] [--[no]inspect] [--[no]readline] [--prompt mode] [--prompt-mode mode] [--inf-ruby-mode] [--simple-prompt] [--noprompt] [--tracer] [--back-trace-limit n] [--irb_debug 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.

-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

--readline

Uses Readline extension module.

--noreadline

Doesn't use Readline extension module.

--prompt mode

--prompt-mode mode

Switch prompt mode. Pre-defined prompt modes are `default', `simple', `xmp' and `inf-ruby'.

--inf-ruby-mode

Uses prompt appropriate for inf-ruby-mode on emacs. Suppresses --readline.

--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.

--irb_debug n

Sets internal debug level to n (not for popular use)

ENVIRONMENT

IRBRC

Also irb depends on same variables as ruby(1).

FILES

~/.irbrc: Personal irb initialization.

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

%

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 Keiju ISHITSUKA.