A filesystem monitoring adapter for the Unison file synchronizer with macOS support.

go get -u github.com/benesch/unison-fswatcher

In -repeat watch mode, Unison can automatically re-sync whenever it notices that a file has changed. This mode relies on an adapter program, unison-fsmonitor, that provides the system-specific glue for filesystem notifications. Unison ships with an adapter for Linux and Windows, but not for macOS.

This unison-fsmonitor adapter program is written in Go and supports macOS. It should, in principle, support other operating systems—the underlying filesystem notification library supports most popular operating systems—but it has only been tested on macOS.

Notably, this adapter handles following symlinks better than the other available macOS adapters.

For the curious, the adapter protocol is documented in the fswatch.ml file in Unison's source code.

unison-fsmonitor is freely available under the terms of the MIT license.

There are several similar projects that provide a unison-fsmonitor adapter for macOS.

• autozimu/unison-fsmonitor
• caleb/unison-fsmonitor-macos
• hnsl/unox