Ruby script to calculate a summary of the list of NOAA's weather stations.

noaa_stations.rb

# ***************************************
# Ruby script to calculate a summary of 
# the list of NOAA's weather stations.
# ***************************************
require 'open-uri'

class NoaaStations
  FILE = "http://www.aviationweather.gov/static/adds/metars/stations.txt"

  def initialize
    @hash = Hash.new(0)
    @cnt_c = 0
  end

  # メイン処理
  def exec_main
    # ファイル読込＆集計
    compile

    # 結果出力
    display
  rescue => e
    puts "[#{e.class}] #{e.message}"
    e.backtrace.each{|trace| puts "\t#{trace}"}
    exit 1
  end

  private

  # ファイル読込＆集計
  def compile
    open(FILE) do |f|
      while l = f.gets
        l.chomp!
        next if l =~ /^\!/
        next if l.split(//).size < 80
        country_code = l[(-2)..(-1)]
        @hash[country_code] += 1
      end
    end
  rescue => e
    raise
  end

  # 結果出力
  def display
    @hash.sort_by{|k, v| k}.sort_by{|k, v| -v}.each do |k, v|
      print k == "JP" ? " *" : "  "
      printf("#{k}:%4d", v.to_i)
      puts if (@cnt_c += 1) % 10 == 0
    end
    puts "\nCount of countries: #{@cnt_c}"
  rescue => e
    raise
  end
end

NoaaStations.new.exec_main