Hi, I have come across a very weird problem while trying to use Tk::ProgressBar.
Basically when running the following code, the output of the Label() after creating the ProgressBar seems to contain random bytes of the source code of the script itself rather than the value of the variable.

here is the example script:

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

my %pid=(ex1=>{as=>'temp', val=>'-21.5'});

my $mw=MainWindow->new();
my $tmpbar=$mw->Frame()->pack( -padx=>30 );
PBar( \$tmpbar, \$pid{ex1}{val}, '-30', '70' )->pack();
$tmpbar->Label( -textvariable => \$pid{ex1}{val} )->pack();
$tmpbar->Label( -text => "$pid{ex1}{as}" )->pack();

print STDOUT "val Labels: $pid{ex1}{val}\n";

MainLoop;

sub PBar {
    my($frame, $val, $min, $max)=@_;
    print STDOUT "val PBar1: $$val\n";
    my $pbar=$$frame->ProgressBar(
        -anchor=>'s',
        -width=>40,
        -length=>500,
        -blocks=>100,
        -gap=>1,
        -resolution=>0.5,
        -variable=>$val,
        -from=>$min,
        -to=>$max
    );
    print STDOUT "val PBar2: $$val\n";
    return $pbar;
}

[download]
when running this script you will see that the Label under the vertical ProgressBar instead of containing the value of $pid{ex1}{val}, prints out three random bytes that appear to be from the source of the script itself.

What is happening here? Memory corruption? ::confused::

Also (this is my second question), why does ProgressBar modify the value of $pid{ex1}{val} rather than just reading it?

In reply to weird case of memory corruption? by perltux

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