For an example see inotify_ini: http://php.net/inotify-init(PECL inotify >= 0.1.2)
inotify_add_watch — Add a watch to an initialized inotify instance
   inotify_add_watch() adds a new watch or modify an
   existing watch for the file or directory specified in
   pathname.
  
   Using inotify_add_watch() on a watched object replaces
   the existing watch. Using the IN_MASK_ADD constant
   adds (OR) events to the existing watch.
  
inotify_instanceVon inotify_init() zurückgegebene Ressource
pathnameFile or directory to watch
maskEvents to watch for. See Vordefinierte Konstanten.
   The return value is a unique (inotify instance wide) watch descriptor,
   Bei einem Fehler wird false zurückgegeben..
  
For an example see inotify_ini: http://php.net/inotify-init