putting the "loop" into read-evaluate-print-loop

echo_graceful_exit.rb

first_loop = true

loop do
  # Trap ^C aka interrupt signal 
  Signal.trap("INT") { 
    puts "\nGoodbye!"
    exit
  }

  [
    "This loop echos everything you input.",
    "Type <Ctl-c> to exit.",
  ].each do |line|
    puts line
  end if first_loop

  # the last item of array is the return of `gets`
  response = [
    print("Enter your text: "), # the prompt, returns nil
    gets.chomp  # returns the users input minus the end of line char
  ].last

  puts response  # prints response to screen
  
  first_loop = false

end