[Command Line Countdown Coding Gadgets](https://www.amazon.com/Digital-Kitchen-Countdown-Cooking-Gadgets/dp/B078SNB7DH)

timer.rb

#!/usr/bin/ruby
# timer.rb

# README
# usage:
# chmod +x timer.rb
# ./timer.rb <minutes>
# ex $./timer.rb 25

def flush_print(content)
  print content + "\r"
  $stdout.flush
end

def percent_string(percent, timer)
  current = "#" * percent
  others  = " " * (100 - percent)
  summary = "#{current}%"
  "[#{current}#{others}] #{percent}% #{timestamp(timer)}"
  # [#########################################################################                           ] 73% 00:06:35
  # [####################################################################################################] 100% 00:00:00
end

def timestamp(time)
  Time.at(time).utc.strftime("%H:%M:%S")
end

def count_down(minutes)
  seconds = minutes * 60
  percent = 0
  seconds.times do |time|
    current = (time / seconds.to_f * 100).to_i
    sleep 1
    if current != percent
      percent == current
    end
    flush_print(percent_string(current, seconds - time))
  end
  puts percent_string(100, 0)
end

count_down(ARGV[0].to_i)