IRB(1)

 

NAME

irb – Interactive Ruby Shell  

SYNOPSIS

[--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

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

 

OPTIONS

–version

Prints the version of .

-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 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

%