Z
Generated by scripts/gen-format-pages.py from docs/data/format-metadata/, FILE_FORMATS.csv and docs/formats-master.csv. Do not edit by hand: change the source, then run the script.
Unix compress (.Z) Preview.
At a glance
| Purpose | A file compressed by the Unix compress tool: LZW codes after a 3-byte header. |
| Extensions | .Z |
| Poka parser | poka-z-compress |
| Viewer | poka-metadata-card-viewer |
| Depth tier | Metadata card (see Depth tiers) |
| Breadth tier | B5 Identification (see Breadth tiers) |
How much Poka reads
B5 Identification. The format is recognised and a few properties are shown (name, size, version string). Nothing of the content is decoded.
Confidence: medium (the reviewer read the code). Basis: Reviewed 2026-10-26: read parsers/poka-z-compress/src/main.rs (148 lines) and plugin.json. No unit tests or tests/samples.rs; the corpus has no .Z and .z-compress sample. Covers .Z and .z-compress. The card decodes the 3-byte header (maximum code width, block mode, reserved bits) and shows the payload size, with a hint to decompress with uncompress or gzip. Judgement: B5: only the header is decoded; the compressed data is not walked or decoded.
What Poka does not read
- The data is not decompressed, so the content is not shown (the original file name is not stored in the format)
Libraries
Libraries Poka uses or has assessed for this format, with the status, licence and language the registry records.
- libarchive (candidate; BSD-2-Clause; C; https://github.com/libarchive/libarchive/wiki/LibarchiveFormats) — Lists compress as a read/write filter with an internal implementation; licence (BSD-style, two clauses) from its COPYING file
- ncompress (candidate; Unlicense; C; https://github.com/vapier/ncompress) — Reference compress/uncompress implementation; page states public domain and points to UNLICENSE; C inferred from file names
- dcompress (candidate; BSD-2-Clause; Go; https://github.com/hotei/dcompress) — Decompress-only Go translation of ncompress 4.2; README says Simplified BSD
- lzws (candidate; BSD-3-Clause; unknown; https://github.com/andrew-aladev/lzws) — Streaming LZW compressor/decompressor, README says compatible with UNIX compress in LSB mode; implementation language not stated on page (likely C)
Sources
- parsers/poka-z-compress/src/main.rs
- parsers/poka-z-compress/plugin.json