from

# File lib/rubygems/package/tar_header.rb, line 99
  def self.from(stream)
    header = stream.read 512
    empty = (header == "\00"" * 512)

    fields = header.unpack UNPACK_FORMAT

    new :name     => fields.shift,
        :mode     => strict_oct(fields.shift),
        :uid      => strict_oct(fields.shift),
        :gid      => strict_oct(fields.shift),
        :size     => strict_oct(fields.shift),
        :mtime    => strict_oct(fields.shift),
        :checksum => strict_oct(fields.shift),
        :typeflag => fields.shift,
        :linkname => fields.shift,
        :magic    => fields.shift,
        :version  => strict_oct(fields.shift),
        :uname    => fields.shift,
        :gname    => fields.shift,
        :devmajor => strict_oct(fields.shift),
        :devminor => strict_oct(fields.shift),
        :prefix   => fields.shift,

        :empty => empty
  end