#!/usr/bin/env ruby
# encoding: utf-8
class String
    def is_integer?
      self.to_i.to_s == self
    end
end
class Integer
  def to_filesize
    {
      'B'  => 1024,
      'KB' => 1024 * 1024,
      'MB' => 1024 * 1024 * 1024,
      'GB' => 1024 * 1024 * 1024 * 1024,
      'TB' => 1024 * 1024 * 1024 * 1024 * 1024
    }.each_pair { |e, s| return "#{(self.to_f / (s / 1024)).round(2)}#{e}" if self < s }
  end
end
class Numeric
  def percent_of(n)
    self.to_f / n.to_f * 100.0
  end
end