The London Perl and Raku Workshop takes place on 26th Oct 2024. If your company depends on Perl, please consider sponsoring and/or attending.


Filesys::Notify::Simple - Simple and dumb file system watcher


  use Filesys::Notify::Simple;

  my $watcher = Filesys::Notify::Simple->new([ "." ]);
  $watcher->wait(sub {
      for my $event (@_) {
          $event->{path} # full path of the file updated


Filesys::Notify::Simple is a simple but unified interface to get notifications of changes to a given filesystem path. It utilizes inotify2 on Linux, fsevents on OS X, kqueue on FreeBSD and FindFirstChangeNotification on Windows if they're installed, with a fallback to the full directory scan if they're not available.

There are some limitations in this module. If you don't like it, use File::ChangeNotify.

  • There is no file name based filter. Do it in your own code.

  • You can not get types of events (created, updated, deleted).

  • Currently wait method blocks.

In return, this module doesn't depend on any non-core modules. Platform specific optimizations with Linux::Inotify2, Mac::FSEvents, Filesys::Notify::KQueue and Win32::ChangeNotify are truely optional.

NOTE: Using Win32::ChangeNotify may put additional limitations.

  • Win32::ChangeNotify uses FindFirstChangeNotificationA so that Unicode characters can not be handled. On cygwin (1.7 or later), Unicode characters should be able to be handled when Win32::ChangeNotify is not used.

  • If more than 64 directories are included under the specified paths, an error occurrs.


Tatsuhiko Miyagawa <>


This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.


File::ChangeNotify Mac::FSEvents Linux::Inotify2 Filesys::Notify::KQueue Win32::ChangeNotify