How to monitor a folder for new files in swift?

Question

How would I monitor a folder for new files in swift, without polling (which is very inefficient)? I\'ve heard of APIs such as kqueue and FSEvents - but I\'m not sure it\'s p

Answer 1

I adapted Stanislav Smida's code to make it work with Xcode 8 and Swift 3

class DirectoryObserver {

    private let fileDescriptor: CInt
    private let source: DispatchSourceProtocol

    deinit {

      self.source.cancel()
      close(fileDescriptor)
    }

    init(URL: URL, block: @escaping ()->Void) {

      self.fileDescriptor = open(URL.path, O_EVTONLY)
      self.source = DispatchSource.makeFileSystemObjectSource(fileDescriptor: self.fileDescriptor, eventMask: .all, queue: DispatchQueue.global())
      self.source.setEventHandler { 
          block()
      }
      self.source.resume()
  }

}