#---------------------------------------------------------------------
package Win32::ChangeNotify;
#
# Copyright 1998 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.ActiveWare.com
#
#   Other modifications (c) 1997 by Gurusamy Sarathy <gsar@umich.edu>
#
# Author: Christopher J. Madsen <chris_madsen@geocities.com>
# Version: 1.00 (6-Feb-1998)
#
# This program is free software; you can redistribute it and/or modify
# it under the same terms as Perl itself.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See either the
# GNU General Public License or the Artistic License for more details.
#
# Monitor directory for changes
#---------------------------------------------------------------------

$VERSION = '1.01';

use Carp;
use Win32::IPC 1.00 '/./';      # Import everything
require Exporter;
require DynaLoader;

@ISA = qw(Exporter DynaLoader Win32::IPC);
# Items to export into callers namespace by default. Note: do not export
# names by default without a very good reason. Use EXPORT_OK instead.
# Do not simply export all your public functions/methods/constants.
@EXPORT = qw(
	FILE_NOTIFY_CHANGE_ATTRIBUTES
	FILE_NOTIFY_CHANGE_DIR_NAME
	FILE_NOTIFY_CHANGE_FILE_NAME
	FILE_NOTIFY_CHANGE_LAST_WRITE
	FILE_NOTIFY_CHANGE_SECURITY
	FILE_NOTIFY_CHANGE_SIZE
	INFINITE
);
@EXPORT_OK = qw(
  wait_all wait_any
);

sub AUTOLOAD {
    # This AUTOLOAD is used to 'autoload' constants from the constant()
    # XS function.

    my($constname);
    ($constname = $AUTOLOAD) =~ s/.*::_//;
    #reset $! to zero to reset any current errors.
    $!=0;
    my $val = constant($constname, @_ ? $_[0] : 0);
    if ($! != 0) {
        ($pack,$file,$line) = caller;
        die "Your vendor has not defined Win32::ChangeNotify macro $constname, used at $file line $line.";
    }
    eval "sub $AUTOLOAD { $val }";
    goto &$AUTOLOAD;
}

bootstrap Win32::ChangeNotify;

sub new {
    my ($class,$path,$subtree,$filter) = @_;

    if ($filter =~ /\A[\s|A-Z_]+\Z/i) {
        $filter = 0;
        foreach (split(/[\s|]+/, $_[3])) {
            $filter |= constant("FILE_NOTIFY_CHANGE_" . uc $_);
            carp "Invalid filter $_" if $!;
        }
    }
    _new($class,$path,$subtree,$filter);
} # end new

sub Close { &close }

sub FindFirst { $_[0] = Win32::ChangeNotify->_new(@_[1..3]); }

sub FindNext { &reset }

1;
__END__

=head1 NAME

Win32::ChangeNotify - Monitor events related to files and directories

=head1 SYNOPSIS

	require Win32::ChangeNotify;

	$notify = Win32::ChangeNotify->new($Path,$WatchSubTree,$Events);
	$notify->wait or warn "Something failed: $!\n";
	# There has been a change.

=head1 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.

The C<wait> method and C<wait_all> & C<wait_any> functions are
inherited from the L<"Win32::IPC"> module.

=head2 Methods

=over 4

=item $notify = Win32::ChangeNotify->new($path, $subtree, $filter)

Constructor for a new ChangeNotification object.  C<$path> is the
directory to monitor.  If C<$subtree> is true, then all directories
under C<$path> will be monitored.  C<$filter> indicates what events
should trigger a notification.  It should be a string containing any
of the following flags (separated by whitespace and/or C<|>).

   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

(C<$filter> can also be an integer composed from the
C<FILE_NOTIFY_CHANGE_*> constants.)

=item $notify->close

Shut down monitoring.  You could just C<undef $notify> instead (but
C<close> works even if there are other copies of the object).  This
happens automatically when your program exits.

=item $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 C<new>, but it is not required.)

=item $notify->wait

See L<"Win32::IPC">.  Remember to call C<reset> afterwards if you want
to continue monitoring.

=back

=head2 Deprecated Functions and Methods

B<Win32::ChangeNotify> still supports the ActiveWare syntax, but its
use is deprecated.

=over 4

=item FindFirst($Obj,$PathName,$WatchSubTree,$Filter)

Use

  $Obj = Win32::ChangeNotify->new($PathName,$WatchSubTree,$Filter)

instead.

=item $obj->FindNext()

Use C<$obj-E<gt>reset> instead.

=item $obj->Close()

Use C<$obj-E<gt>close> instead.

=back

=head1 AUTHOR

Christopher J. Madsen E<lt>F<chris_madsen@geocities.com>E<gt>

Loosely based on the original module by ActiveWare Internet Corp.,
F<http://www.ActiveWare.com>

=cut

# Local Variables:
# tmtrack-file-task: "Win32::ChangeNotify"
# End:
