LibFuseSharp 1.0.1

LibFuseSharp

A FUSE 3 high-level mount library for .NET on Linux (libfuse3) and macOS (macFUSE). Implement a read-only volume, mount it with one call, and probe the runtime before you mount.

Source: purelogiccode/LibFuseSharp. Used by SimpleXisoDrive and CHDMounter.

Requirements

• Linux (x64 or ARM64) with libfuse3 (for example sudo apt install libfuse3-3 fuse3) and /dev/fuse available, or macOS (Intel or Apple silicon) with macFUSE installed.
• .NET 8, 9 or 10 runtime.

Set the LIBFUSESHARP_LIBRARY environment variable to override the FUSE library path used for probing and loading (mainly useful for tests and custom installations). The legacy SIMPLEXISODRIVE_FUSE_LIBRARY name is still honored as a fallback.

Quick start

Implement IFuseVolume for your data source:

using FuseSharp;

public sealed class MyVolume : IFuseVolume
{
    public string VolumeLabel => "MyVolume";
    public DateTime VolumeCreationTime => DateTime.UtcNow;
    public ulong VolumeSize => 1024 * 1024;

    public IFuseEntry? GetEntry(string path) { /* look up "/file.txt", "/" ... */ }
    public IEnumerable<IFuseEntry> GetFolderList(string path) { /* list "/" ... */ }
    public int ReadFile(IFuseEntry entry, Span<byte> buffer, long offset) { /* fill buffer ... */ }
}

Check the runtime, then mount (blocks until unmounted):

if (!FuseAvailability.Check(out var library))
    return; // installation guidance was already printed to stderr

var fs = new FuseFileSystem(new MyVolume());
var exitCode = fs.Run("/mnt/myvolume", debug: false, onMounted: () => Console.WriteLine("Mounted"));

FuseFileSystem.Run drives the FUSE session manually and shuts it down cleanly on Ctrl+C, SIGTERM or SIGHUP. Call fs.Exit() from any thread to request a shutdown (for example when your application closes). External unmounts (umount, fusermount3 -u, Finder eject) close the FUSE device; fuse_loop then returns -ENODEV, which is treated as a normal end of the session once init ran, so Run returns 0.

To check only whether mounting is possible — without printing installation guidance — use:

if (FuseAvailability.Check(out _, candidates: null, printInstructions: false))
    Console.WriteLine("FUSE is available.");

API overview

The volume is exposed read-only: open rejects write access, macOS setattr returns EROFS, and unimplemented operations fail with ENOSYS.

License

MIT — see LICENSE.txt. Lead Developer: Peterson Fernandes (PureLogicCode.com).