cl-fs-watcher

A Simple Filesystem Watcher to monitor a given directory for changes. This is ALPHA quality software and only works on Linux and Windows (for now).

Dependencies

• cl-async (Available through Quicklisp)
• lparallel (Available through Quicklisp)

Installation

Just clone it into quicklisp/local-project and run (ql:quickload :cl-fs-watcher)

Examples

To start Watching ~/watch-me/ for changes run:

(defun callback (watcher pathname event-type)
  (format t "something happend on watcher: ~a, which watches: ~a!~%"
            watcher (cl-fs-watcher:dir watcher))
  (format t "it happened to: ~a, event: ~a~%"
            pathname event-type))

(defparameter *my-watcher* nil)
(setf *my-watcher*
      (make-instance 'cl-fs-watcher:watcher
                     :dir (pathname "~/watch-me/") ;; watch ~/watch-me/
                     :recursive-p t ;; also watch all subdirectories
                     :hook #'callback
                     :error-cb (lambda (ev)
                                 (format t "ERROR: ~a~%" ev)
                                 (cl-fs-watcher:stop-watcher *my-watcher*))))

(start-watcher *my-watcher*)

callback will be called if something changes on ~/watch-me/ or its subdirectories. The First argument to callback will be the watcher object itself (here *my-watcher*), path will be the absolute path to the modified file and event-type will be one of the following:

• :file-added (will always be followed by a :file-changed event with the same path)
• :file-removed
• :file-changed
• :directory-added
• :directory-removed
• :on-deleted (given if the main directory, which is watched by WATCHER (:dir initarg to make-instance (here ~/watch-me)), is deleted. If the Hook returns (here function callback) the Event Loop will finish and the Watcher THREAD will terminate)

Use (cl-fs-watcher:stop-watcher *my-watcher*) to cleanup all handles and terminate the Event-Loop. This wont be necessary if :on-deleted occurs, because the watcher will terminate itself.