user_mask

# File lib/bundler/vendor/fileutils/lib/fileutils.rb, line 791
  def user_mask(target)  #:nodoc:
    target.each_char.inject(0) do |mask, chr|
      case chr
      when "u"
        mask | 04700
      when "g"
        mask | 02070
      when "o"
        mask | 01007
      when "a"
        mask | 07777
      else
        raise ArgumentError, "invalid `who' symbol in file mode: #{chr}"
      end
    end
  end