NAME

       irb — Interactive Ruby Shell

SYNOPSIS

       irb  [--version] [-dfUw] [-I directory] [-r library] [-E external[:internal]] [-W[level]] [--[no]inspect]
           [--[no]multiline] [--[no]singleline] [--[no]echo] [--[no]colorize]  [--[no]verbose]  [--prompt  mode]
           [--prompt-mode      mode]     [--inf-ruby-mode]     [--simple-prompt]     [--noprompt]     [--tracer]
           [--back-trace-limit 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.

       -w             Same as `ruby -w' .

       -W             Same as `ruby -W' .

       -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

       --multiline    Uses multiline editor module.

       --nomultiline  Doesn't use multiline editor module.

       --singleline   Uses singleline editor module.

       --nosingleline
                      Doesn't use singleline editor module.

       --echo         Show result(default).

       --noecho       Don't show result.

       --colorize     Use colorization.

       --nocolorize   Don't use colorization.

       --verbose      Show details.

       --noverbose    Don't show details.

       --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   --multiline   and
                      --singleline.

       --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.

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
             %

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.

       •   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.

UNIX                                             August 11, 2019                                          IRB(1)