Win32::ChangeNotify - Monitor events related to files and directories
This document describes version 1.09 of Win32::ChangeNotify, released January 14, 2012 as part of Win32-IPC version 1.09.
require Win32::ChangeNotify; $notify = Win32::ChangeNotify->new($Path,$WatchSubTree,$Events); $notify->wait or warn "Something failed: $!\n"; # There has been a change.
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.
wait method and
wait_any functions are inherited from the Win32::IPC module.
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
$path must be a Windows pathname, not a Cygwin Unix-like pathname.
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.
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.) Returns true if successful, or zero if it fails (additional error information can be found in
See Win32::IPC. Remember to call
reset afterwards if you want to continue monitoring.
Win32::ChangeNotify still supports the ActiveWare syntax, but its use is deprecated.
$Obj = Win32::ChangeNotify->new($PathName,$WatchSubTree,$Filter)
Win32::ChangeNotify requires no configuration files or environment variables.
It runs under 32-bit or 64-bit Microsoft Windows, either natively or under Cygwin.
Prior to version 1.06, the Win32 IPC modules treated
undef values differently. In version 1.06 and later, passing
undef as the value of an optional parameter is the same as omitting that parameter. In previous versions,
undef was interpreted as either the empty string or 0 (along with a warning about "Use of uninitialized value...").
Signal handlers will not be called during the
wait method. See "BUGS AND LIMITATIONS" in Win32::IPC for details.
Christopher J. Madsen
<perl AT cjmweb.net>
Please report any bugs or feature requests to
<bug-Win32-IPC AT rt.cpan.org> or through the web interface at http://rt.cpan.org/Public/Bug/Report.html?Queue=Win32-IPC.
You can follow or contribute to Win32-IPC's development at http://github.com/madsen/win32-ipc.
Loosely based on the original module by ActiveWare Internet Corp., http://www.ActiveState.com
Copyright 1998-2012 Christopher J. Madsen
Created: 3 Feb 1998 from the ActiveWare version (c) 1995 Microsoft Corporation. All rights reserved. Developed by ActiveWare Internet Corp., http://www.ActiveState.com
Other modifications (c) 1997 by Gurusamy Sarathy <gsar AT cpan.org>
This module is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
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