Swift File System Monitor is a Swift 5 library used to monitor changes to the filesystem.
It is based on the convenient APIs from Daniel Pederson's SKQueue but replaces kevent with Dispatch Source as the means for monitoring changes. The mechanism is similar to Apple's own Directory Monitor (reference to which can be found here), but SFSMonitor gives a complete API for maintaining a whole queue of watched files and folders.

Please go through the README and the code for additional details and examples.