irb Man page

IRB(1) Ruby Programmers Reference Guide IRB(1)

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.

-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. Sup‐
presses –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.

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.

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 vul‐
nerabilities via the system because it publishes the vulnerabilities
immediately.

AUTHORS
Written by Keiju ISHITSUKA.

UNIX November 15, 2012 UNIX