I want the code to stop, let the user make some modifications to the input in the main window and then try again without completely shutting down the program.

Here's a piece of working code that does just that: 

#!/usr/bin/env perl

use strict;
use warnings;

use Tk;

my $mw = MainWindow->new();

$mw->Label(-text => 'Enter integers only:')->pack;
$mw->Entry(
    -validate => 'key',
    -validatecommand => sub { $_[0] =~ /^\d+$/ },
    -invalidcommand => \&lam_num_error,
)->pack;

$mw->Button(-text => 'Exit', -command => sub { exit })->pack;

MainLoop;

sub lam_num_error {
    $mw->messageBox(-message=>"The input must be an integer.");
}

[download]

This is very basic and is only intended to show an example of Tk::Entry Validation. As it is, it only allows positive integers: you may want to change that.

Note that there's no die or exit in lam_num_error(). An Exit button is provided for users to quit the application.

-- Ken

In reply to Re: Die vs. Exit by kcott
in thread Die vs. Exit by shortyfw06

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