poka.sh

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Z01

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Split ZIP Volume Preview.

At a glance
Purpose The first volume of a split or spanned ZIP archive (.z01), whose central directory lives in the last volume.
Extensions .z01
Poka parser poka-z01
Viewer poka-table-viewer
Depth tier Parser with a shared viewer (see Depth tiers)
Breadth tier B4 Summary (see Breadth tiers)

How much Poka reads

B4 Summary. The container and metadata are read and summarised (counts, properties, structure), but the main content is not rendered.

Confidence: medium (the reviewer read the code). Basis: Reviewed 2026-10-26: read parsers/poka-z01/src/main.rs (498 lines) and plugin.json. The 11 unit tests cover the spanning marker, entries continuing in the next volume, streamed entries, ZIP64 sizes, middle volumes and truncated headers; the corpus has test-documents-spanned.z01, read by no test. Covers .z01. The table lists the local file headers found in this volume (name, method, compressed and uncompressed size, notes such as encrypted, UTF-8 or continues in the next volume) and stops, saying why, at a streamed entry or the volume's end. Judgement: B4: the archive is listed but no member is extracted or shown.

What Poka does not read

  • Member contents are not extracted or shown
  • The other volumes are not read, so entries that start elsewhere are not listed
  • Middle volumes (.z02 and up) usually start inside a payload and cannot be listed
  • A streamed entry (sizes in a data descriptor) ends the scan
  • Only the first 1,000 entries are listed; files over 64 MiB are cut (flagged)

Libraries

Libraries Poka uses or has assessed for this format, with the status, licence and language the registry records.

  • zipunsplit (zipunsplitlib) (reference; GPL-3.0-only; Rust; https://github.com/chenxiaolong/zipunsplit) — copyleft; Joins .z01/.z02/.zip parts into one standard zip by rewriting disk-relative offsets; CLI-first, library crate has no API stability guarantees
  • Zip4j (candidate; Apache-2.0; Java; https://github.com/srikanth-lingala/zip4j) — Supports extracting split zip files (z01, z02 ... zip) and merging them; README has no explicit extraction example for split archives
  • Apache Commons Compress (candidate; Apache-2.0; Java; https://commons.apache.org/proper/commons-compress/zip.html) — Reads split archives (since 1.20) via ZipSplitReadOnlySeekableByteChannel built from the parts; licence inferred from the Apache licence link on the page

Sources

  • parsers/poka-z01/src/main.rs
  • parsers/poka-z01/plugin.json