MAGICFFI is a CFFI interface to libmagic(3), the file type determination library using “magic” numbers.


To check out the git repository, run:

$ git clone git://

To browse code online, go to:

You can also download the repo’s snapshot.


MAGICFFI depends on the following lisp libraries:

  • CFFI

  • CL-PPCRE (used by the internal flags generator)

The following system packages are also required:

  • libmagic-dev

  • libc6-dev

  • gcc

You have to install them on your system before loading magicffi.


> (asdf:oos 'asdf:load-op :magicffi)
> (use-package :magicffi)
> (with-open-magic (magic '(:mime-type :symlink))
    (magic-load magic)
    (magic-file magic #P"magicffi.asd"))


All external symbols of the package MAGICFFI are listed in package.lisp. Check out their docstrings for help.

Magic Flags

You can use either constants or keyword list as magic flags. I.e.,

(magic-open (logxor +magic-mime-type+ +magic-symlink+))

is equivalent to

(magic-open '(:mime-type :symlink))

The constant name and keyword name of a flag are based on its C name. See the following table for the pattern:

Table 1. Magic flags naming convension

C name

Lisp constant

Lisp keyword




All constant names are exported.

Support and mailing lists

If you have questions, bug reports, feature requests and patches, send your email to the magicffi-devel mailing list. Please visit: