Ruby script to calculate a Japan's calendar with a selfmade gem library.

calendar.rb

#! /usr/local/bin/ruby
# coding: utf-8
require 'date'
require 'mk_calendar'

class Calendar
  USAGE   = "[USAGE] .calendar.rb [YYYYMMDD]"
  MSG_ERR = "[ERROR] Invalid date!"

  def initialize
    @date = ARGV.shift
    @date ||= Time.now.strftime("%Y%m%d")
    unless @date =~ /\d{8}/
      puts USAGE
      exit 0
    end
    unless Date.valid_date?(@date[0,4].to_i, @date[4,2].to_i, @date[6,2].to_i)
      puts MSG_ERR
      exit 0
    end
  end

  def calc
    @obj = MkCalendar.new(@date)
    str =  sprintf("%04d-%02d-%02d", @obj.year, @obj.month, @obj.day)
    str << " #{@obj.yobi}曜日"
    str << " #{@obj.holiday}" unless @obj.holiday == ""
    str << " #{@obj.jd}UTC(#{@obj.jd_jst}JST) #{@obj.kanshi} "
    str << sprintf("%04d-%02d-%02d", @obj.oc[0], @obj.oc[2], @obj.oc[3])
    str << "(閏)" if @obj.oc[1] == 1
    str << " #{@obj.oc[4]}"
    str << " #{@obj.sekki_24}" unless @obj.sekki_24 == ""
    str << " #{@obj.zassetsu}" unless @obj.zassetsu == ""
    str << " #{@obj.sekku}" unless @obj.sekku == ""
    str << " #{@obj.lambda_sun} #{@obj.lambda_moon} #{@obj.moonage}"
    puts str
  rescue => e
    $stderr.puts "[#{e.class}] #{e.message}"
    e.backtrace.each { |tr| $stderr.puts "\t#{tr}"}
    exit 1
  end
end

Calendar.new.calc if __FILE__ == $0