soulware.rb

require 'rubygems'
require 'rufus-scheduler'


class CronScheduler

  def initialize (opts={})
    @frequency = opts[:frequency] || 0.3
    @jobs = []
  end

  def run
    loop do
      t = Time.now
      @jobs.each do |job|
        if t >= job[:at]
          job[:block].call
          job[:at] = Rufus::CronLine.new(job[:cron]).next_time(t)
        end
      end
      sleep(@frequency)
    end
  end

  def cron (s, &block)

    @jobs << {
      :cron => s,
      :at => Rufus::CronLine.new(s).next_time(Time.now + 1),
      :block => block
    }
  end
end

s = CronScheduler.new

s.cron '* * * * *' do
  puts "#{Time.now} new sun on new world"
end

s.run