irb man page

irb — Interactive Ruby Shell


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 ...]


irb is the REPL(read-eval-print loop) environment for Ruby programs.


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

Same as `ruby -U' . Sets the default value for internal encodings (Encoding.default_internal) to UTF-8.

Same as `ruby -d' . Sets $DEBUG to true.

Suppresses read of ~/.irbrc.

Prints a summary of the options.

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

-r library
Same as `ruby -r'. Causes irb to load the library using require.

Uses `inspect' for output (default except for bc mode)

Doesn't use inspect for output

Uses Readline extension module.

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'.

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

Makes prompts simple.

No prompt mode.

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)



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


Personal irb initialization.


% irb

irb(main):001:0> 1 + 1


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

irb(main):009:0> quit


See Also


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.


Written by Keiju ISHITSUKA.


Explore man page connections for irb(1).