dissect.cstruct

What it is and what it does

dissect.cstruct is a binary structure parser that lets you define C-like structures in a simple text format and use them to parse raw binary data into Python objects. It handles common C constructs—basic types, arrays, enums, unions, nested structures, and bit fields—with minimal syntax overhead. You write a structure definition, load it into a parser instance, then call the resulting structure class on binary data (bytes or file-like objects) to get back a Python object with typed fields that you can read, modify, and serialize back to bytes.

The library is designed for simplicity: no complex syntax, filters, or preprocessing—just straightforward structure parsing. It's particularly useful for reverse-engineering binary file formats, parsing kernel data structures, or handling custom binary protocols where you can reuse structure definitions from existing C codebases with little or no modification. It compiles structures to optimized Python classes by default for better performance.

Use it for:

• Parse EXT4 superblocks or other kernel data structures by copying C definitions from Linux source.
• Reverse-engineer custom binary file formats by defining their layout and parsing samples.
• Handle binary network protocols or file formats where you need bidirectional serialization.
• Parse forensic or log data with fixed binary layouts in incident response workflows.
• Work with embedded device data or firmware images with known C struct definitions.

Worth the install?

AI-flagged interpretation of the facts on this page — verify before relying

Parse binary data using C-like structure definitions, converting raw bytes into typed Python objects and back again.

Yes. Zero dependencies, active maintenance, stable API, and Apache-2.0 licensing make it a low-risk choice. Install if you need to parse binary data with C-like structures; the straightforward syntax and ability to reuse real C definitions from open-source projects make it significantly more practical than manual struct.unpack() calls for complex formats.

Install

dissect-cstruct on PyPI

pip install dissect-cstruct

uv add dissect-cstruct

poetry add dissect-cstruct

Installing dissect.cstruct

Before you install

Low install friction with no runtime dependencies. Active maintenance since 2018, last commit 2026-08-10, and marked Production/Stable.

License in practice

Apache-2.0 permissive license allows commercial and private use with minimal restrictions.

Quickstart

from dissect.cstruct import cstruct

parser = cstruct().load("""
struct example {
    uint8 a;
    char b[5];
};
""")

data = b"\x01hello"
result = parser.example(data)
print(result.a, result.b)

Requires Python 3.10 or later.

Verify before relying

• Whether compiled structures (the default) provide measurable performance gains for typical workloads.
• Compatibility with structure definitions from specific C projects or standards beyond the Linux kernel example given.

Package facts

Evidence: dissect_cstruct-4.7-py3-none-any.whl

Tags

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