ChangeNotify(3) User Contributed Perl Documentation ChangeNotify(3)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
perl v5.14.2 2005-09-17 ChangeNotify(3)
