case "linux":
			// Copied from golang.org/x/sys/unix/dev_linux.go.
			major := uint32((dev & 0x00000000000fff00) >> 8)
			major |= uint32((dev & 0xfffff00000000000) >> 32)
			minor := uint32((dev & 0x00000000000000ff) >> 0)
			minor |= uint32((dev & 0x00000ffffff00000) >> 12)
			h.Devmajor, h.Devminor = int64(major), int64(minor)
		case "darwin", "ios":
			// Copied from golang.org/x/sys/unix/dev_darwin.go.
			major := uint32((dev >> 24) & 0xff)

		header:  &Header{ModTime: time.Unix(1, 500)},
		paxHdrs: map[string]string{paxMtime: "1.0000005"},
		formats: FormatUSTAR | FormatPAX | FormatGNU,
	}, {
		header:  &Header{ModTime: time.Unix(1, 0)},
		formats: FormatUSTAR | FormatPAX | FormatGNU,
	}, {
		header:  &Header{ModTime: time.Unix(1, 0), Format: FormatPAX},
		formats: FormatUSTAR | FormatPAX,
	}, {
		header:  &Header{ModTime: time.Unix(1, 500), Format: FormatUSTAR},

		if ts.IsZero() {
			return // Always okay
		}
		if !fitsInBase256(size, ts.Unix()) {
			whyNoGNU = fmt.Sprintf("GNU cannot encode %s=%v", name, ts)
			format.mustNotBe(FormatGNU)
		}
		isMtime := paxKey == paxMtime
		fitsOctal := fitsInOctal(size, ts.Unix())
		if (isMtime && !fitsOctal) || !isMtime {
			whyNoUSTAR = fmt.Sprintf("USTAR cannot encode %s=%v", name, ts)

				Uname:    "dsymonds",
				Gname:    "eng",
				ModTime:  time.Unix(1246508266, 0),
			}, nil},
			testWrite{"Kilts", 5, nil},

			testHeader{Header{
				Typeflag: TypeReg,
				Name:     "small2.txt",
				Size:     11,
				Mode:     0640,
				Uid:      73025,
				Uname:    "dsymonds",
				Gname:    "eng",
				Gid:      5000,
				ModTime:  time.Unix(1245217492, 0),
			}, nil},

				Content:  []byte("important \r\n"),
				Modified: time.Date(2011, 12, 8, 10, 6, 8, 0, time.UTC),
				Mode:     0444,
			},
		},
	},
	{
		// created by Zip 3.0 under Linux
		Name: "unix.zip",
		File: []ZipTestFile{
			{
				Name:     "hello",
				Content:  []byte("world \r\n"),
				Modified: time.Date(2011, 12, 8, 10, 4, 24, 0, timeZone(0)),
				Mode:     0666,
			},
			{

			prefix = p.parseString(star.prefix())
			hdr.AccessTime = time.Unix(p.parseNumeric(star.accessTime()), 0)
			hdr.ChangeTime = time.Unix(p.parseNumeric(star.changeTime()), 0)
		case format.has(FormatGNU):
			hdr.Format = format
			var p2 parser
			gnu := tr.blk.toGNU()
			if b := gnu.accessTime(); b[0] != 0 {
				hdr.AccessTime = time.Unix(p2.parseNumeric(b), 0)
			}
			if b := gnu.changeTime(); b[0] != 0 {

		// if modification time is the only timestamp being encoded.
		var mbuf [9]byte // 2*SizeOf(uint16) + SizeOf(uint8) + SizeOf(uint32)
		mt := uint32(fh.Modified.Unix())
		eb := writeBuf(mbuf[:])
		eb.uint16(extTimeExtraID)
		eb.uint16(5)  // Size: SizeOf(uint8) + SizeOf(uint32)
		eb.uint8(1)   // Flags: ModTime
		eb.uint32(mt) // ModTime
		fh.Extra = append(fh.Extra, mbuf[:]...)