Gem::Package::TarHeader#header

# File tmp/rubies/ruby-3.3.0/lib/rubygems/package/tar_header.rb, line 221
def header(checksum = @checksum)
  header = [
    name,
    oct(mode, 7),
    oct(uid, 7),
    oct(gid, 7),
    oct(size, 11),
    oct(mtime, 11),
    checksum,
    " ",
    typeflag,
    linkname,
    magic,
    oct(version, 2),
    uname,
    gname,
    oct(devmajor, 7),
    oct(devminor, 7),
    prefix,
  ]

  header = header.pack PACK_FORMAT

  header << ("\0" * ((512 - header.size) % 512))
end