cmagic

Python wrapper for libmagic.

Usage

# MacOS
$ export MAGIC=/usr/local/Cellar/libmagic/5.39/share/misc/magic.mgc

# Ubuntu
$ export MAGIC=/usr/lib/file/magic.mgc

import cmagic

# Database path from MAGIC environment variable
m = cmagic.Magic()

if m.check():
   print("Database is ok")

m.load()

m.guess_file("/etc/hosts")
# 'ASCII text'
m.guess_bytes("hello world")
# 'ASCII text'

# Setting flags
m.set_flags(mime_type=True)


m = cmagic.Magic(
   # Setting flags here
   mime_type=True
)

# Trying to find database on the standard paths
m.load(cmagic.find_db())

m.guess_file("/etc/hosts")
# 'text/plain'

m.guess_bytes("hello world")
# 'text/plain'

asyncio example

import asyncio
import cmagic
from threading import local


magic_tls = local()


def get_instance():
    global magic_tls

    if not hasattr(magic_tls, "instance"):
        m = cmagic.Magic(mime_type=True)
        m.load(cmagic.find_db())
        magic_tls.instance = m

    return magic_tls.instance


async def guess_file(fname):
    loop = asyncio.get_event_loop()

    def run():
        m = get_instance()
        return m.guess_file(fname)

    return await loop.run_in_executor(None, run)


async def guess_bytes(payload):
    loop = asyncio.get_event_loop()

    def run():
        m = get_instance()
        return m.guess_bytes(payload)

    return await loop.run_in_executor(None, run)


if __name__ == "__main__":
    print(asyncio.run(guess_file("/etc/hosts")))
    # text/plain
    print(asyncio.run(guess_bytes(b"\0\0\0\0\0\0\0")))
    # application/octet-stream

Installation

Ubuntu/Debian

apt-get install -y libmagic1 libmagic-mgc   # when using manilinux wheel
apt-get install -y libmagic-dev             # for building from sources
python3 -m pip install cmagic

Centos

yum install -y file-libs            # when using manilinux wheel
yum install -y file-devel           # for building from sources
python3 -m pip install cmagic

MacOS

brew install libmagic
export CFLAGS="-I$(brew --prefix libmagic)/include" LDFLAGS="-L$(brew --prefix libmagic)/lib"
python3 -m pip install cmagic