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]autocomplete]
           [--[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.

       --extra-doc-dir
                      Add an extra doc dir for the doc dialog.

       --echo         Show result (default).

       --noecho       Don't show result.

       --echo-on-assignment
                      Show result on assignment.

       --noecho-on-assignment
                      Don't show result on assignment.

       --truncate-echo-on-assignment
                      Show truncated result on assignment (default).

       --colorize     Use colorization.

       --nocolorize   Don't use colorization.

       --autocomplete
                      Use autocompletion.

       --noautocomplete
                      Don't use autocompletion.

       --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

       IRB_LANG         The locale used for irb.

       IRBRC            The path to the personal initialization file.

       XDG_CONFIG_HOME  irb respects XDG_CONFIG_HOME. If this  is  set,  load  $XDG_CONFIG_HOME/irb/irbrc  as  a
                        personal initialization file.

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

FILES

       ~/.irbrc
               Personal  irb  initialization.  If  IRBRC  is  set,  read $IRBRC instead. If IRBRC is not set and
               XDG_CONFIG_HOME is set, $XDG_CONFIG_HOME/irb/irbrc is loaded.

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)