Here are two progs that works under linux, I have no way to test under windows. You should read "perldoc perlsec" for info about security and tainted data. You untaint data with regexps, remember to be careful.

#!/usr/bin/perl -w

use strict;
use Tk;

my $mw = MainWindow->new();

my $file_name = 'Some file';

$mw->send('Foo' => $file_name);

#!/usr/bin/perl -Tw

use strict;
use Tk;

my $main_window = MainWindow->new(-title => 'My other prog');
$main_window->appname('Foo');

MainLoop;

sub Tk::Receive{
    shift;
    my $string = shift;

    if (my ($file) = $string =~ /^([^-]+)$/){
        print "Got: $file\n";
        exit 0;
    }
    else {
        print "Wrong arg Received\n";
        exit 1;
    }
}
[download]