call

# File railties/lib/rails/rack/logger.rb, line 13
      def call(env)
        response = @app.call(env)
        ::File.open(@path, 'r') do |f|
          f.seek @cursor
          if f.mtime > @last_checked
            contents = f.read
            @last_checked = f.mtime
            @cursor += contents.length
            print contents
          end
        end
        response
      end