How to implement interactive breakpoint - like functionality.

When calling a script from irb/command line. You can use this snippet to take statements from stdin and evaluate them in the current context just like IRB. Use qq to stop.

if options[:debug]
  STDOUT << ">> "
  while (cmd=gets.chomp)!="qq"
      puts eval(cmd).inspect
      STDOUT << ">> "
  end
end