pygfried

README

Pygfried

pygfried is a CPython extension that brings siegfried - a powerful, signature-based file format identification tool written in Go - into the Python ecosystem.

Instead of reimplementing siegfried's logic, pygfried embeds the original Go code directly, making core siegfried functionality available to Python users without any changes to the underlying detection engine.

No animals were harmed in the making of this extension.

Usage

$ pip install pygfried
$ python -q
>>> import pygfried
>>> pygfried.version()
'1.11.2'
>>> pygfried.identify("example.png")
'fmt/11'
>>> pygfried.identify("example.png", detailed=True)
{'siegfried': '1.11.2', 'scandate': '2025-06-10T07:16:31+02:00', 'signature': 'default.sig', 'created': '2025-03-01T15:28:08+11:00', 'identifiers': [{'name': 'pronom', 'details': 'DROID_SignatureFile_V120.xml; container-signature-20240715.xml'}], 'files': [{'filename': 'example.png', 'filesize': 237675, 'modified': '2025-06-10T07:11:26+02:00', 'errors': '', 'matches': [{'ns': 'pronom', 'id': 'fmt/11', 'format': 'Portable Network Graphics', 'version': '1.0', 'mime': 'image/png', 'class': 'Image (Raster)', 'basis': 'extension match png; byte match at [[0 16] [237663 12]]', 'warning': ''}]}]}
>>> pygfried.identify_many(["example.png", "README.md"], workers=2)
{'siegfried': '1.11.2', ...}
>>> pygfried.identify_dir("samples", recursive=True, workers=2)
{'siegfried': '1.11.2', ...}

Batch and directory scans

Use identify_many when you already have a list of paths, or identify_dir when you want pygfried to scan a directory for you. Both functions return the same detailed result shape as identify(..., detailed=True).

>>> from pathlib import Path
>>> paths = [str(path) for path in Path("samples").rglob("*.png")]
>>> pygfried.identify_many(paths, workers=4)
{'siegfried': '1.11.2', ...}
>>> pygfried.identify_dir("samples", recursive=True, workers=4)
{'siegfried': '1.11.2', ...}

The workers argument controls Go-side concurrency. The default is 1, which is the most conservative setting. For directories or large path lists, higher values can be much faster because pygfried avoids repeated Python-to-Go calls and identifies multiple files in parallel. A good starting point is the number of CPU cores available to your process, then measure with your own files.

By default identify_dir skips symlinks. Use follow_symlinks=True to identify file symlinks and descend symlinked directories; directory cycles are skipped, and repeated links to the same directory are scanned once.

Limitations

Go libraries can clash

This project uses Go's -buildmode=c-shared to provide its Python extension. Loading multiple Go-based shared libraries in the same process is unsupported and may result in panics or crashes due to conflicts between separate Go runtimes.

This limitation should only affect you if you're using pygfried together with another Python library that also uses a Go extension (built with the same c-shared mechanism) in the same process. If you're just using pygfried on its own, you don't need to worry - everything should work as expected.

Credits

pygfried is powered by the original siegfried project, which is distributed under the Apache License, Version 2.0. All core file format identification logic and signatures are provided by siegfried. We gratefully acknowledge the work of the siegfried project and its contributors.

Documentation

Index

• func IdentifyAllWithJSON(paths []string) (string, error)
• func IdentifyAllWithJSONOptions(paths []string, opts IdentifyOptions) (string, error)
• func IdentifyDirWithJSON(path string, opts IdentifyDirOptions) (string, error)
• func IdentifyWithJSON(path string) (string, error)
• func Version() string
• type IdentifyDirOptions
• type IdentifyOptions
• type Result
  • func Identify(path string) (*Result, error)
  • func IdentifyAll(paths []string) ([]*Result, error)
  • func IdentifyAllWithOptions(paths []string, opts IdentifyOptions) ([]*Result, error)

Functions

func IdentifyAllWithJSON

func IdentifyAllWithJSON(paths []string) (string, error)

func IdentifyAllWithJSONOptions

func IdentifyAllWithJSONOptions(paths []string, opts IdentifyOptions) (string, error)

func IdentifyDirWithJSON

func IdentifyDirWithJSON(path string, opts IdentifyDirOptions) (string, error)

func IdentifyWithJSON

func IdentifyWithJSON(path string) (string, error)

func Version

func Version() string

Types

type IdentifyDirOptions

type IdentifyDirOptions struct {
	Recursive      bool
	Workers        int
	FollowSymlinks bool
}

type IdentifyOptions

type IdentifyOptions struct {
	Workers int
}

type Result

type Result struct {
	Path        string
	Identifiers []string
	Known       bool
	Error       string
}

func Identify

func Identify(path string) (*Result, error)

func IdentifyAll

func IdentifyAll(paths []string) ([]*Result, error)

func IdentifyAllWithOptions

func IdentifyAllWithOptions(paths []string, opts IdentifyOptions) ([]*Result, error)