# File lib/rubygems/indexer.rb, line 298
  def build_rss(index)
    if @rss_host.nil? or @rss_gems_host.nil? then
      if Gem.configuration.really_verbose then
        alert_warning "no --rss-host or --rss-gems-host, RSS generation disabled"
      end
      return
    end

    require 'cgi'
    require 'rubygems/text'

    extend Gem::Text

    Gem.time 'Generated rss' do
      open @rss_index, 'wb' do |io|
        rss_host = CGI.escapeHTML @rss_host
        rss_title = CGI.escapeHTML(@rss_title || 'gems')

        io.puts "<?xml version=\"1.0\"?>\n<rss version=\"2.0\">\n<channel>\n<title>\#{rss_title}</title>\n<link>http://\#{rss_host}</link>\n<description>Recently released gems from http://\#{rss_host}</description>\n<generator>RubyGems v\#{Gem::RubyGemsVersion}</generator>\n<docs>http://cyber.law.harvard.edu/rss/rss.html</docs>\n"

        today = Gem::Specification::TODAY
        yesterday = today - 86400

        index = index.select do |_, spec|
          spec_date = spec.date

          case spec_date
          when Date
            Time.parse(spec_date.to_s) >= yesterday
          when Time
            spec_date >= yesterday
          end
        end

        index = index.select do |_, spec|
          spec_date = spec.date

          case spec_date
          when Date
            Time.parse(spec_date.to_s) <= today
          when Time
            spec_date <= today
          end
        end

        index.sort_by { |_, spec| [-spec.date.to_i, spec] }.each do |_, spec|
          gem_path = CGI.escapeHTML "http://#{@rss_gems_host}/gems/#{spec.full_name}.gem"
          size = File.stat(spec.loaded_from).size rescue next

          description = spec.description || spec.summary || ''
          authors = Array spec.authors
          emails = Array spec.email
          authors = emails.zip(authors).map do |email, author|
            email += " (#{author})" if author and not author.empty?
          end.join ', '

          description = description.split(/\n\n+/).map do |chunk|
            format_text chunk, 78
          end

          description = description.join "\n\n"

          item = ''

          item << "<item>\n<title>\#{CGI.escapeHTML spec.full_name}</title>\n<description>\n&lt;pre&gt;\#{CGI.escapeHTML description.chomp}&lt;/pre&gt;\n</description>\n<author>\#{CGI.escapeHTML authors}</author>\n<guid>\#{CGI.escapeHTML spec.full_name}</guid>\n<enclosure url=\\\"\#{gem_path}\\\"\nlength=\\\"\#{size}\\\" type=\\\"application/octet-stream\\\" />\n<pubDate>\#{spec.date.rfc2822}</pubDate>\n"

          item << "<link>\#{CGI.escapeHTML spec.homepage}</link>\n" if spec.homepage

          item << "</item>\n"

          io.puts item
        end

        io.puts "</channel>\n</rss>\n"
      end
    end

    @files << @rss_index
  end