irb man page

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.

-m
Bc mode (load mathn, fraction or matrix are available)

-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

=> nil

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.

And you can report other bugs and feature requests via the Ruby Issue Tracking System (http://bugs.ruby-lang.org). Do not report security vulnerabilities via the system because it publishes the vulnerabilities immediately.

Authors

Written by Keiju ISHITSUKA.

Info

November 15, 2012