simple_prompt_loop.rb

#! /usr/bin/env ruby

def handle_input str
	if str.nil?
		puts "Bye."
		exit
	end
	puts "REVERSO:  #{str.reverse}"
end

$stdout.sync = true # This forces the buffer to be flushed after every write.
loop {
	print "prompt> "
	input = $stdin.gets
	handle_input input
}