libmagic-ffm

Java 22 Panama FFM bindings for file/libmagic with bundled, from-source native libraries and the compiled magic.mgc signature database. One Maven coordinate, batteries included: no JNI and no user-installed libmagic.

Artifact	Contents	License
io.github.ghosthack:libmagic-ffm	All public functions and API constants, native loader, and Java-friendly Magic wrapper	MIT
io.github.ghosthack:libmagic-ffm-natives (macos-arm64, windows-x64, linux-x64)	file/libmagic 5.48 shared library and magic.mgc	BSD-2-Clause; Windows support DLLs also BSD/LGPL-2.1+

Status: initial 5.48-0.1.0-SNAPSHOT implementation. Supported platforms are macOS ARM64, Windows x64, and Linux x64.

Use

<dependency>
<groupId>io.github.ghosthack</groupId>
<artifactId>libmagic-ffm</artifactId>
<version>5.48-0.1.0-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>io.github.ghosthack</groupId>
<artifactId>libmagic-ffm-natives</artifactId>
<version>5.48-0.1.0-SNAPSHOT</version>
<classifier>macos-arm64</classifier> <!-- windows-x64 / linux-x64 -->
<scope>runtime</scope>
</dependency>

On the module path, declare requires libmagic.ffm; and run with --enable-native-access=libmagic.ffm. On the class path, use --enable-native-access=ALL-UNNAMED.

The owning wrapper loads the bundled database automatically:

importio.github.ghosthack.libmagicffm.Magic;
importio.github.ghosthack.libmagicffm.libmagic.LibMagic;
importjava.nio.file.Path;
try (Magicmagic = Magic.open(LibMagic.MAGIC_MIME_TYPE())) {
Stringmime = magic.file(Path.of("photo.jpg"));
StringbufferMime = magic.buffer(bytes);
}

The generated C surface is available through LibMagic when direct control of magic_t, database buffers, parameters, or descriptors is needed:

intnativeVersion = LibMagic.magic_version(); // 548

Resolution order

1. -Dlibmagicffm.libdir=<dir> or LIBMAGIC_FFM_LIBDIR loads shared libraries from an existing installation.
2. The current platform's natives jar is extracted once to ~/.cache/libmagic-ffm/<version>-<platform>/ and loaded.
3. Libraries already loaded by the host process and the native linker's default symbols are searched.

Set -Dlibmagicffm.database=<magic.mgc> or LIBMAGIC_FFM_DATABASE to replace the bundled database independently. This also makes both the library and its data user-replaceable.

Building

Build each native jar on its target platform. On macOS ARM64:

mkdir -p build
curl -sfL https://www.astron.com/pub/file/file-5.48.tar.gz | tar xz -C build
build-natives/macos-arm64.sh
JEXTRACT_HOME=/path/to/jextract-22 jextract/gen-bindings.sh
mvn clean install

The generated Java source is committed; consumers and ordinary builds do not need jextract. Staged native resources are build outputs and are not committed. See tools/README.md for the jextract 22 download.