timer.rb

#!/usr/bin/env ruby
# ruby timer.rb 3m ramen_ok &
require 'time'
require 'date'

NOHUP_FLAG = '___nohup___'

def main(delay, message)
  wait(parse_time(delay))
  notify(message)
end

def wait(sec)
  puts "sleep #{sec}sec"
  sleep sec
end

def parse_time(time)
  return 0 if time.to_i == 0
  if time =~ /^([0-9]+)([a-zA-Z]*)$/
    $1.to_i * rate($2)
  elsif time =~ /^([0-9]+):([0-9]+)$/
    next_time = get_next_time($1, $2)
    next_time.to_i - Time.now.to_i
  else
    time.to_i
  end
end

def get_next_time(hour, min)
  now = Time.now
  t = make_time(Date.today, hour, min)
  (t > now) ? t : make_time(Date.today + 1, hour, min)
end

def make_time(date, hour, min)
  Time.parse(date.strftime('%Y/%m/%d ') + ("%02d:%02d" % [hour, min]))
end

def rate(unit)
  case (unit)
  when /s(ec)?/i
    1
  when /m(in)?/i
    60
  when /h(our)?/i
    60 * 60
  else
    1
  end
end

def notify(message)
  msg = message || "notice from #{hostname}"
  system('notify_send', message)
end

if (ARGV[0] != NOHUP_FLAG)
  #system(*(['nohup', 'ruby', $0, NOHUP_FLAG] + ARGV))
  %x(#{(['nohup', 'ruby', __FILE__, NOHUP_FLAG] + ARGV.map{|s| '"' + s + '"'}).join(' ')})
else
  main(ARGV[1], ARGV[2])
end