ZIP structure

Read a ZIP central directory without extracting: entry list, compression method, ratios, offsets, and a zip-bomb heuristic.

ZIP structure reads a ZIP's central directory without unpacking a file, listing each entry's compression method, sizes, ratio and header offset. An archive claiming more entries or bytes than classic fields allow gets read through the ZIP64 locator instead. A ratio past 100 to 1, or 1 GB declared, raises a zip-bomb warning; a missing directory record is refused.

Questions

Does this extract the files?

No, it only reads the central directory, entry names, sizes and offsets, without inflating any file content.

What does each row show?

Entry name, compression method, compressed and uncompressed size, compression ratio, and the local header offset.

Does it support ZIP64 archives?

Yes, it follows the ZIP64 locator and extra fields when an archive declares more entries or bytes than the classic 32-bit fields can hold.

What triggers the zip-bomb warning?

A compression ratio over 100 to 1 on any entry, or 1 GB of total declared uncompressed content across the archive.

What if there is no End Of Central Directory record?

The tool refuses, treating the file as not a ZIP or as truncated.

Compare

Tool	Runs on the CLI	Live as you type
ZIP structure	Yes	No
Parse ASN.1	Yes	No
Parse Object Identifier	Yes	No
TLV / Tag-Length-Value parser	Yes	No
ELF info	Yes	No
PNG chunks	Yes	No
JPEG structure	Yes	No

Related Forensics tools

n→nParse ASN.1Decode a DER-encoded ASN.1 structure (certificates, keys, PKCS blobs) into a readable tree.n→nParse Object IdentifierDecode a raw ASN.1 OBJECT IDENTIFIER byte string (tag and length already stripped) into dotted-decimal form.n→nTLV / Tag-Length-Value parserWalk a generic Tag-Length-Value byte structure with a configurable tag width and either a fixed-width or ASN.1 BER length field: protocol frames, binary records, custom containers.n→nELF infoRead an ELF binary's header and section table: class, architecture, entry point, sections. No disassembly.n→nPNG chunksWalk a PNG's chunk structure, type, length, offset, CRC validity, and decode IHDR and any text chunks.n→nJPEG structureList a JPEG's marker segments and quantization tables, or produce an Error Level Analysis image to spot re-compression artifacts.