Working draft

F55 type-contiguous

A contiguous file, typeflag 7.

Tolerate(draft) A strict parser may reject this archive. If it accepts it, it must extract the expected tree below.

Category
framing
Default policy
accepts it: the file is extracted as a regular file, as POSIX asks of implementations without contiguous files
Files
F55-type-contiguous.tar test archive, 2,048 bytes sha256 b1fb59edf5026005ddc18429cf327e1aa880606f0d956a21903194ba9a775f05
F55-type-contiguous.jsonexpected result
F55-type-contiguous.txtannotated blocks
F55-type-contiguous.pygenerator script

The case

The archive has one member, a, of typeflag 7, whose data is a, followed by a newline.

In POSIX, typeflag 7 is reserved for a file with some high-performance attribute. This means a contiguous file: a file stored in consecutive blocks on disk. Implementations without such extensions should treat it as a regular file. A reader that does not recognize typeflag 7 extracts it as a regular file too. This case is tolerated because POSIX gives it one reading: as a regular file, or as a contiguous file where they are supported, the file is a with its data. A strict parser may reject it, as it may reject any typeflag that it does not support. A reader that skips the member extracts nothing.

The expected tree:

pathkindcontents
afile2 bytes, sha256 87428fc5

Seen in: none of the scanned tarballs.

The archive

Every block of 512 bytes, to scale, with its offset. Hover over a field for its bytes.

F55-type-contiguous: every block of the archive0x000000header: unknown type, a contiguous filename [0,100): "a" + 99 NULnamemode [100,108): "0000644" + NUL, 644 (octal)uid [108,116): "0000000" + NUL, 0gid [116,124): "0000000" + NUL, 0size [124,136): "00000000002" + NUL, 2mtime [136,148): "00000000000" + NUL, 0chksum [148,156): "007347\0 ", 3815: the unsigned sum of the header, this field as spacestypeflag [156,157): "7", unknown typeflaglinkname [157,257): 100 NULlinknamemagic [257,263): "ustar" + NULversion [263,265): "00"uname [265,297): 32 NULunamegname [297,329): 32 NULgnamedevmajor [329,337): "0000000" + NUL, 0devminor [337,345): "0000000" + NUL, 0prefix [345,500): 155 NULprefixpad [500,512): 12 NULname "a" + 99 NUL0x000200data2 bytes, then 510 NUL to the end of the block; "a\n""a\n"0x0004002 zero blocks: the end-of-archive markerbytes 0 to 512 of 1024: 512 NUL0x0006002 zero blocks, continuedbytes 512 to 1024 of 1024: 512 NUL0x000800end of fileNULprintable ASCIIspacecontrol character, such as a newlinebyte over 0x7fwritten by the case itself
Every block, as text 
F55-type-contiguous: tolerated: a strict parser may reject it; if it accepts it, it must extract its tree, and the default policy accepts it

A contiguous file, typeflag `7`.

The archive has one member, `a`, of typeflag `7`, whose data is `a`, followed by a newline.

In POSIX, typeflag `7` is reserved for a file with some high-performance
attribute. This means a contiguous file: a file stored in
consecutive blocks on disk. Implementations without such extensions should treat it as
a regular file. A reader that does not recognize typeflag `7` extracts it as a regular
file too. This case is tolerated because POSIX gives it one reading: as a regular
file, or as a contiguous file where they are supported, the file is `a` with its data. A strict
parser may reject it, as it may reject any typeflag that it does not support. A reader that skips
the member extracts nothing.

Seen in: none of the scanned tarballs.
See also: F16, an unknown typeflag with a size.

0x000000  header: unknown type, a contiguous file
          name     [  0,100)  "a" + 99 NUL
          mode     [100,108)  "0000644" + NUL  644 (octal)
          uid      [108,116)  "0000000" + NUL  0
          gid      [116,124)  "0000000" + NUL  0
          size     [124,136)  "00000000002" + NUL  2
          mtime    [136,148)  "00000000000" + NUL  0
          chksum   [148,156)  "007347\0 "  3815: the unsigned sum of the header, this field as spaces
          typeflag [156,157)  "7"  unknown typeflag
          linkname [157,257)  100 NUL
          magic    [257,263)  "ustar" + NUL
          version  [263,265)  "00"
          uname    [265,297)  32 NUL
          gname    [297,329)  32 NUL
          devmajor [329,337)  "0000000" + NUL  0
          devminor [337,345)  "0000000" + NUL  0
          prefix   [345,500)  155 NUL
          pad      [500,512)  12 NUL
0x000200  data
          2 bytes, then 510 NUL to the end of the block
          "a\n"
0x000400  2 zero blocks: the end-of-archive marker
0x000800  end of file
Every byte, as a hex dump

As xxd writes it: xxd -r makes the archive of it.

00000000: 6100 0000 0000 0000 0000 0000 0000 0000  a...............
00000010: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000020: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000030: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000040: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000050: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000060: 0000 0000 3030 3030 3634 3400 3030 3030  ....0000644.0000
00000070: 3030 3000 3030 3030 3030 3000 3030 3030  000.0000000.0000
00000080: 3030 3030 3030 3200 3030 3030 3030 3030  0000002.00000000
00000090: 3030 3000 3030 3733 3437 0020 3700 0000  000.007347. 7...
000000a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000100: 0075 7374 6172 0030 3000 0000 0000 0000  .ustar.00.......
00000110: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000120: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000130: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000140: 0000 0000 0000 0000 0030 3030 3030 3030  .........0000000
00000150: 0030 3030 3030 3030 0000 0000 0000 0000  .0000000........
00000160: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000170: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000180: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000190: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000200: 610a 0000 0000 0000 0000 0000 0000 0000  a...............
00000210: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000220: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000230: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000240: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000250: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000260: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000270: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000280: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000290: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000300: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000310: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000320: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000330: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000340: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000350: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000360: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000370: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000380: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000390: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000400: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000410: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000420: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000430: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000440: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000450: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000460: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000470: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000480: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000490: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000500: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000510: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000520: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000530: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000540: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000550: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000560: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000570: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000580: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000590: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000600: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000610: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000620: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000630: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000640: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000650: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000660: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000670: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000680: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000690: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000700: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000710: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000720: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000730: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000740: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000750: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000760: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000770: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000780: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000790: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................

What implementations make of it

In the outcome column, ✅ means that the implementation follows the default policy.

implementationversionoutcomewhat it makes of it
GNU tartar (GNU tar) 1.35➕ acceptsthe expected tree
bsdtarbsdtar 3.8.11 - libarchive 3.8.11➕ acceptsthe expected tree
BusyBox tarBusyBox v1.38.0, defconfig➕ acceptsthe expected tree
7-Zip7-Zip (z) 26.05 (x64)➕ acceptsthe expected tree
Python tarfile, filter=data, as in pipCPython 3.15.2➕ acceptsthe expected tree
Python tarfile, filter=tarCPython 3.15.2➕ acceptsthe expected tree
Python tarfile, filter=fully_trustedCPython 3.15.2➕ acceptsthe expected tree
node-tartar 7.5.22➕ acceptsthe expected tree
node-tar, stricttar 7.5.22➕ acceptsthe expected tree
tar-fstar-fs 3.1.3, on tar-stream 3.2.2➖ rejectserror: Error: unsupported type for DEST/a (contiguous-file)
Java Commons CompressCommons Compress 1.28.0, Expander, on Java 27.0.1.0.2➕ acceptsthe expected tree
.NET System.Formats.TarSystem.Formats.Tar of .NET 10.0.14, ExtractToDirectory➕ acceptsthe expected tree
PHP PharData, as in ComposerPharData of PHP 8.5.12, as Composer's TarDownloader calls it➕ acceptsthe expected tree
Go containerd archive.Applycontainerd v2.4.2, archive.Apply, of go1.27.3➖ rejectserror: unhandled tar header type 55
Rust tartar 0.4.46, unpack➕ acceptsthe expected tree
Rust astral-tokio-tarastral-tokio-tar 0.7.1, unpack➕ acceptsthe expected tree
Rust tar-codec, as in uvtar-codec 0.0.16, with the policies of uv 0.13➕ acceptsthe expected tree
RubyGemsRubyGems 4.0.20 of Ruby 4.0.9, extract_tar_gz❌ another tree, or rejectstree A: nothing
R untar, internalutils::untar of R 4.6.2, tar = "internal"➖ rejectserror: unsupported entry type ‘7’
Perl Archive::TarArchive::Tar 3.12 of Perl v5.44.0❌ another tree, or rejectstree A: nothing
Haskell tartar 0.7.2.0, extract, of GHC 9.14➕ acceptsthe expected tree
Julia Tar.jlTar 1.10.0 of Julia 1.13.3➖ rejectserror: unsupported entry type Tar.Header("a", Symbol("7"), 0o644, 2, "")
live-bootstrap untarmescc-tools-extra a151c245e512, as live-bootstrap pins it➕ acceptsthe expected tree
live-bootstrap untar, --non-strictmescc-tools-extra a151c245e512, as live-bootstrap pins it➕ acceptsthe expected tree

Prevalence in release tarballs

The table below shows how many release tarballs have the features of this test case.

ecosystemtarballswith itshare
Spack37,5530none
nixpkgs18,9900none
Guix10,1680none
PyPI10,0000none
crates.io5,0000none
RubyGems5,0000none
live-bootstrap1710none
total (distinct)82,5860none

See also