Text Upside Down with Ruby. data source: twitter→ɹəʇʇɪʍʇのように英数字を180度回転して表示する方法｜Colorless Green Ideas http://id.fnshr.info/2013/01/25/upsidedowntext/

scraper.rb

# encoding: UTF-8
require "nokogiri"
require "open-uri"

class Scraper
  class << self
    def build(path, target)
      parse get(path), target
    end

    def get(url)
      Nokogiri::HTML(open url)
    rescue OpenURI::HTTPError => e
      STDERR.puts "HTTP Access Error:#{e}"
      exit
    end

    def parse(html, target)
      q = []
      html.css(target).each do |tr|
        q << tr
      end
      q
    end
  end
end

textupdown

#!/usr/bin/env ruby
require_relative 'textupdown'
require "optparse"

opt = OptionParser.new

method = :text
opt.on('-c') { method = :code }
opt.on('-t') { method = :text }
opt.parse!(ARGV)

puts TextUpDown.new.send(method, ARGV.join(' '))

__END__
Usage:
  % updown hello, world!
  % updown -c hello, world! #get codepoints

textupdown.rb

# encoding: UTF-8
# Text Upside Down with Ruby by kyoendo
# Data source from Fumiaki Nishihara
# Read this;
# twitter→ɹəʇʇɪʍʇのように英数字を180度回転して表示する方法｜Colorless Green Ideas
# http://id.fnshr.info/2013/01/25/upsidedowntext/
require "yaml"
require_relative "scraper"

class TextUpDown
  URL = "http://id.fnshr.info/2013/01/25/upsidedowntext/"
  Path = File.expand_path(File.dirname(__FILE__))
  PAIR = %w(( [ < ) ] >)
  def initialize
    @table = nil
    @code = {}
  end

  def text(text)
    code(text).map do |c|
      case c
      when /^U\+/
        $'.to_i(16).chr('UTF-8')
      when *PAIR
        PAIR[ (PAIR.index(c) + 3) % PAIR.size ]
      else
        c
      end
    end.join
  end

  def code(text)
    @code[text] ||= begin
      text.reverse.chars.map { |chr| (table[chr] || [chr]).sample }
    end
  end
  
  def table(path=nil)
    path = File.join(Path, 'textupdown.yaml') unless path
    @table ||= begin
      data =
        if File.exist?(path)
          YAML.load_file(path)
        else
          get(URL).tap do |res|
            File.write(path, YAML.dump(res))
          end
        end
      build_table(data)
    end
  end

  def get(url)
    body = Scraper.build(url, 'table tr')
    body.map { |tr| tr.search('td').map(&:text) }.delete_if(&:empty?)
  end

  def build_table(table)
    res = table.group_by(&:first).map do |k, records|
      [k, records.map { |r| r.last }]
    end
    Hash[res]
  end
end

if __FILE__ == $0
  t = TextUpDown.new
  t.code('twitter')
  t.text("twitter")
end

ugly_update.rb

# -*- coding:utf-8 -*-
# Termtter plugin for ugly messages by kyoendo
require "textupdown"

if RUBY_VERSION < '1.9.0'
  $KCODE = 'u'
  require "jcode"
end

class String
  def mirror(opt)
    reversed = RUBY_VERSION < '1.9.0' ? self.split(//).reverse.join : self.reverse 
    opt.empty? ? self.replace(reversed) : self.replace(self.chop + reversed)
  end
  def rot13(opt=nil)
    from = 'A-Ma-mN-Zn-zあ-なア-ナに-んニ-ン'
    to   = 'N-Zn-zA-Ma-mに-んニ-ンあ-なア-ナ'
    if RUBY_VERSION >= '1.9.0'
      from += '一-盒盓-龥'
      to += '盓-龥一-盒'
    end
    self.tr(from, to)
  end
  def scooch(opt)
    opt = opt.to_i.zero? ? 1 : opt.to_i
    self.split(//).map { |c| opt.times { c = c.next }; c }.join
  end
  def updown(opt=nil)
    TextUpDown.new.text(self)
  end
end

module Termtter::Client
  uglies = {
    :update_mirror => [[:um], :mirror, 'Mirror message'],
    :update_rot13  => [[:u13], :rot13, 'Rot13 message'],
    :update_scooch => [[:us], :scooch, 'Scooch message'],
    :update_crypt  => [[:uc], :crypt, 'Crypt message'],
    :update_updown => [[:uud], :updown, 'Upside down message'],
  }

  uglies.each do |name, (aliases, meth, help)|
    register_command(
      :name => name, :aliases => aliases,
      :exec_proc => lambda {|arg|
        opt = ''
        arg.sub!(/^-\s*([\d\w]+)\s+/) { opt = $1; '' }
        text = "#{arg.send(meth, opt)} ##{meth.to_s}"
        text = text + "#{opt}" if [:update_crypt, :update_scooch].include? name
        Termtter::API::twitter.update(text)
        puts "=> #{text}"
      },
      :help => ["#{name},#{aliases.join(',')} [-VALUE] TEXT", help]
    )
  end
end