F03 end-lone-zero-blockAn end-of-archive marker of one zero block, not two.
Reject(draft) A strict parser must reject this archive.
F03-end-lone-zero-block.tar |
test archive, 1,536 bytes
sha256 52e2ac74f6686cc8b30703024fa4504c0d0fe6fa6b053a2b0b38f984a580fa80 |
F03-end-lone-zero-block.json | expected result |
F03-end-lone-zero-block.txt | annotated blocks |
F03-end-lone-zero-block.py | generator script |
POSIX requires two zero blocks at the end of an archive; most implementations stop at the first, so they extract it all the same.
Decision point: whether one zero block is an end-of-archive marker.
Seen in: eng-rus, srecord 1.64 and cdi2iso 0.1.
Every block of 512 bytes, to scale, with its offset. Hover over a field for its bytes.
F03-end-lone-zero-block: must reject
An end-of-archive marker of one zero block, not two.
POSIX requires two zero blocks at the end of an archive; most implementations stop at the first, so
they extract it all the same.
Decision point: whether one zero block is an end-of-archive marker.
Seen in: eng-rus, srecord 1.64 and cdi2iso 0.1.
See also: F09, one zero block followed by another member, which is rejected as well.
0x000000 header: regular 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) "007340\0 " 3808: the unsigned sum of the header, this field as spaces
typeflag [156,157) "0" regular file
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 1 zero block: one zero block, and the file ends
0x000600 end of file
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 3430 0020 3000 0000 000.007340. 0... 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 ................
| implementation | version | outcome | what it makes of it |
|---|---|---|---|
| GNU tar | tar (GNU tar) 1.35 | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| bsdtar | bsdtar 3.8.10 - libarchive 3.8.10 | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| BusyBox tar | BusyBox v1.38.0, defconfig | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| 7-Zip | 7-Zip (z) 26.05 (x64) | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| Python tarfile, filter=data, as in pip | CPython 3.15.2 | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| Python tarfile, filter=tar | CPython 3.15.2 | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| Python tarfile, filter=fully_trusted | CPython 3.15.2 | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| node-tar | tar 7.5.22 | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| node-tar, strict | tar 7.5.22 | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| tar-fs | tar-fs 3.1.3, on tar-stream 3.2.2 | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| Java Commons Compress | Commons Compress 1.28.0, Expander, on Java 27.0.1.0.2 | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| .NET System.Formats.Tar | System.Formats.Tar of .NET 10.0.14, ExtractToDirectory | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| PHP PharData, as in Composer | PharData of PHP 8.5.12, as Composer's TarDownloader calls it | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| Go containerd archive.Apply | containerd v2.4.2, archive.Apply, of go1.27.3 | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| Rust tar | tar 0.4.46, unpack | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| Rust astral-tokio-tar | astral-tokio-tar 0.7.0, unpack | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| Rust tar-codec, as in uv | tar-codec 0.0.15, with the policies of uv 0.13 | ✅ as the verdict says | error: at byte 1536: missing two-block end-of-archive marker |
| RubyGems | RubyGems 4.0.20 of Ruby 4.0.9, extract_tar_gz | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| R untar, internal | utils::untar of R 4.6.1, tar = "internal" | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| Perl Archive::Tar | Archive::Tar 3.12 of Perl v5.44.0 | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| Haskell tar | tar 0.7.2.0, extract, of GHC 9.14 | ✅ as the verdict says | error: ShortTrailer |
| Julia Tar.jl | Tar 1.10.0 of Julia 1.13.3 | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| live-bootstrap untar | mescc-tools-extra a151c245e512, as live-bootstrap pins it, built with cc | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
| live-bootstrap untar, --non-strict | mescc-tools-extra a151c245e512, as live-bootstrap pins it, built with cc | ⚠️ accepts | tree A: a (2 B, 87428fc5) |
Release tarballs of Spack, nixpkgs, Guix and live-bootstrap, and samples of PyPI, crates.io and RubyGems with end.lone-zero-block. The default policy rejects all of them.
| ecosystem | tarballs | with it | share |
|---|---|---|---|
| Spack | 37,553 | 0 | none |
| nixpkgs | 18,990 | 5 | 0.03% |
| Guix | 10,168 | 0 | none |
| PyPI | 10,000 | 0 | none |
| crates.io | 5,000 | 0 | none |
| RubyGems | 5,000 | 0 | none |
| live-bootstrap | 171 | 0 | none |
| total (distinct) | 82,586 | 5 | <0.01% |
See the list of these 5 tarballs, with the sha256 of each and an example from it.
F09: one zero block followed by another member, which is rejected as well.