To amplify with a code example, look at this Tk code. When the code ref for the button callback is left hanging naked, it gets executed at creation time. I suspected that is what was happening in your Ionotify2 code, the naked coderef was been acted upon at creation time, giving the error can't find "".

#!/usr/bin/perl
use warnings;
use strict;
use Tk;

my $mw = new MainWindow;
$mw->geometry("400x200");

my $button = $mw->Button(-text    => "Sub test exit",
                     
                     # this naked coderef is incorrect, as it causes
                     # the callback to be executed at button creation
                     # time, instead of later at button press
                         -command => \&callback(time),
                     
                     #  below is correct method, put [] around coderef
                     #    -command => [ \&callback, time ],
                         )->pack();

MainLoop;

sub callback{
  my $in = shift;
  print "$in exiting\n";
  Tk::exit;
}
__END__
[download]

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.