I'm trying to read from two Entry widgets and pass their values to a sub. It's not doing what I would expect. Here's the relevant code: 
#!perl

use Tk;
use strict;
use warnings;

my $original_x = 3;
my $original_y = 4;

my $mw = MainWindow -> new;
my $f1 = $mw -> Frame;
my $user_x = $f1 -> Entry (
                    -textvariable => $original_x,
                    -width => 3,
                    ) -> pack;
my $user_y = $f1 -> Entry (
                    -textvariable => $original_y,
                    -width => 3,
                    ) -> pack;
$f1 -> pack;

$mw -> Button (
       -text => "Print Entries",
       -command => [\&print_entries, $user_x -> get(), $original_y],
       ) -> pack;

MainLoop;

sub print_entries {
  print "@_\n";
}

[download]
I would expect the shell output to be the entry in $user_x, a space, and the entry in $user_y. Instead the output is consistantly the hard-coded default value of $original_x, a space, and the hard-coded default value of $original_y (please don't respond and ask if I changed the values in the Entry widgets ;~) Of course I did!).

You can see in the -command option I tried two different methods for getting the values of Entry widgets. Neither seem to work, which puzzels me. Quoth the Emu, "Nevermore!" Wait, that was a different bird. Mastering Perl/Tk says:

5.2.13. Getting the Contents of an Entry Widget
There are two ways to determine the content of the Entry widget: the get method or the variable associated with the -textvariable option. Using the get method, $entry_text = $entry->get() will assign the entire content of the Entry widget into $entry_text.

The code tries both, but doesn't get what I ask for. Any suggestions as to why? After looking a little deeper I changed -command => [\&print_entries, $user_x -> get(), $y_size], to -command => [\&print_entries, $user_x -> cget(-textvariable), $y_size], an still get the same results.

Update: I made one other change and the results changed, but still to something unexpected. I turned -command => [\&print_entries, $user_x -> get(), $y_size], into -command => [\&print_entries, \$user_x -> get(), \$y_size], (note the back-slashes before the $ in the variable names). Now, the shell output is SCALAR(some memory location), a space, and SCALAR(some other memory location). How do I extract the user entry from an Entry widget? Is it relevant that the Entry widget is in a Frame that is a child of the widget that the Button widget is in?

Thanks for your help!

Cheers!
-P
Don't worry about people stealing your ideas. If your ideas are any good, you'll have to ram them down people's throats.
-Howard Aiken

In reply to Tk -textvariable doesn't change when Entry widget changes by Petras

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