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ZIP - Data Descriptor (with signature)

A ZIP written the way a streaming writer must write one: general-purpose bit 3 is set, the local header carries CRC 0 and sizes 0, and the real values follow the compressed data in a data descriptor introduced by the optional PK\x07\x08 signature.

Archive contents — 3 entrieszip
  • README.txt
  • notes.md
  • records.csv

Specifications

Seed
20260807
General Purpose Bit3
true
Descriptor Fields
4-byte fields, PK\x07\x08 signature present
Members
3
Local Header Crc
0
Local Header Sizes
0

Testing contract

Expected to pass
Scenario
Read the archive without seeking backwards, taking each member's CRC and sizes from the trailing data descriptor rather than from the local file header.
Expected result
All 3 members extract with matching CRCs; the local headers report CRC 0 and sizes 0, and the descriptor fields are 4-byte fields, PK\x07\x08 signature present.

What is a .zip file?

ZIP is a widely supported archive format that bundles multiple files and directories into one container, typically with per-file DEFLATE compression and a central directory index. It supports random access to individual entries without decompressing the whole archive. It underlies many document formats such as DOCX and EPUB.

How to use this file

Use an example ZIP to test archive extraction, central-directory parsing, per-entry decompression, and protection against path-traversal (zip-slip) during unpacking.

How to use this file for testing

“ZIP - Data Descriptor (with signature)” is a deterministic Novus Examples fixture for Conversion testing, Error handling. The same content exported across many formats and linked as a group, so you can convert one and diff against the expected twin.

Documented properties for this file: seed 20260807. Compare results against paired or grouped companions on this page when present (clean↔damaged, searchable↔scanned, or format twins) so scores stay reproducible across runs.

Download the file once, keep the path stable in CI or local scripts, and treat the spec table as the contract: dimensions, seeds, field lists, and roles are intentional. Corrupt or invalid samples are labelled as such — expect parsers to fail loudly rather than silently accept them.

Archive fixtures are documented down to their member list (shown on this page) and are deliberately safe — no zip bombs, executables, or hidden payloads. Test extractors against nested, unicode, empty, and encrypted variants.

Code examples

unzip -l data-descriptor-sig.zip     # list members
unzip data-descriptor-sig.zip -d out/  # extract

Generated by generation/archives_p7.py. Free for any use, no attribution required — license.