irb 0.9.6(09/06/30)

Usage: irb.rb [options] [programfile] [arguments] -f Suppress read of ~/.irbrc -m Bc mode (load mathn, fraction or matrix are available) -d Set $DEBUG to true (same as `ruby -d') -r load-module Same as `ruby -r' -I path Specify $LOAD_PATH directory -U Same as `ruby -U` -E enc Same as `ruby -E` -w Same as `ruby -w` -W[level=2] Same as `ruby -W` --context-mode n Set n[0-3] to method to create Binding Object, when new workspace was created --echo Show result(default) --noecho Don't show result --inspect Use `inspect' for output (default except for bc mode) --noinspect Don't use inspect for output --readline Use Readline extension module --noreadline Don't use Readline extension module --prompt prompt-mode/--prompt-mode prompt-mode Switch prompt mode. Pre-defined prompt modes are `default', `simple', `xmp' and `inf-ruby' --inf-ruby-mode Use prompt appropriate for inf-ruby-mode on emacs. Suppresses --readline. --sample-book-mode/--simple-prompt Simple prompt mode --noprompt No prompt mode --single-irb Share self with sub-irb. --tracer Display trace for each execution of commands. --back-trace-limit n Display backtrace top n and tail n. The default value is 16. --irb_debug n Set internal debug level to n (not for popular use) --verbose Show details --noverbose Don't show details -v, --version Print the version of irb -h, --help Print help -- Separate options of irb from the list of command-line args