nth.rb

require 'io/console'

Signal.trap(:SIGINT) { exit }

puts "CTRL-C to quit...\n"

print 'Password: '
password = STDIN.noecho(&:gets)
puts

loop do
  print "Number: "
  index = gets.strip.to_i - 1
  if (char = password[index])
    IO.popen('pbcopy', 'w') { |f| f << char }
    puts "Copied to your clipboard!"
  else
    puts "Your password aint that long"
  end
end

I always get this wrong and end up locking myself out of online banking!