NAME

Win32::ChangeNotify - Monitor events related to files and directories

SYNOPSIS

        require Win32::ChangeNotify;

        $notify = Win32::ChangeNotify->new($Path,$WatchSubTree,$Events);
        $notify->wait or warn "Something failed: $!\n";
        # There has been a change.

DESCRIPTION

This module allows the user to use a Win32 change notification event object from Perl. This allows the Perl program to monitor events relating to files and directory trees.

Unfortunately, the Win32 API which implements this feature does not provide any indication of what triggered the notification (as far as I know). If you're monitoring a directory for file changes, and you need to know which file changed, you'll have to find some other way of determining that. Depending on exactly what you're trying to do, you may be able to check file timestamps to find recently changed files. Or, you may need to cache the directory contents somewhere and compare the current contents to your cached copy when you receive a change notification.

The wait method and wait_all & wait_any functions are inherited from the "Win32::IPC" module.

Methods

$notify = Win32::ChangeNotify->new($path, $subtree, $filter)

Constructor for a new ChangeNotification object. $path is the directory to monitor. If $subtree is true, then all directories under $path will be monitored. $filter indicates what events should trigger a notification. It should be a string containing any of the following flags (separated by whitespace and/or |).

   ATTRIBUTES   Any attribute change
   DIR_NAME     Any directory name change
   FILE_NAME    Any file name change (creating/deleting/renaming)
   LAST_WRITE   Any change to a file's last write time
   SECURITY     Any security descriptor change
   SIZE         Any change in a file's size

($filter can also be an integer composed from the FILE_NOTIFY_CHANGE_* constants.)

$notify->close

Shut down monitoring. You could just undef $notify instead (but close works even if there are other copies of the object). This happens automatically when your program exits.

$notify->reset

Resets the ChangeNotification object after a change has been detected. The object will become signalled again after the next change. (It is OK to call this immediately after new, but it is not required.)

$notify->wait

See "Win32::IPC". Remember to call reset afterwards if you want to continue monitoring.

Deprecated Functions and Methods

Win32::ChangeNotify still supports the ActiveWare syntax, but its use is deprecated.

FindFirst($Obj,$PathName,$WatchSubTree,$Filter)

Use

  $Obj = Win32::ChangeNotify->new($PathName,$WatchSubTree,$Filter)

instead.

$obj->FindNext()

Use $obj->reset instead.

$obj->Close()

Use $obj->close instead.

AUTHOR

Christopher J. Madsen <cjm@pobox.com>

Loosely based on the original module by ActiveWare Internet Corp., http://www.ActiveWare.com