Post a small working example, so the Windows users can try and help. Don't expect us to write your example code.

use Tk;

use IPC::Open3;

use IO::Handle;

use Win32::Process::Kill;

use threads;
use threads::shared;

use Thread::Queue;

$q=Thread::Queue->new;
$qe=Thread::Queue->new;

unlink('out.txt');

my %font=(-font=>[-family=>'Courier New',-size=>10]);
my %width=(-width=>120);

$pid = open3( \*CHILD_IN, \*CHILD_OUT, \*CHILD_ERR, 'cmd.exe' );

print "pid = $pid\n";

sleep(1);

threads->create(\&handle_child_out)->detach;
threads->create(\&handle_child_err)->detach;

print "threads created\n";

autoflush CHILD_OUT;
autoflush CHILD_ERR;

my %font=(-font=>[-family=>'Courier New',-size=>10]);
my %width=(-width=>118);

my $mw=new MainWindow;

my $entry=$mw->Entry(
    %width,
    -relief=>'groove',
    -borderwidth=>5,
    -textvariable=>\$entry_text,
    %font
    )->pack;
    
$entry->focus;
    
$entry->bind('<Key-Return>',\&enter);

my $text=$mw->Scrolled('Text',
    -insertontime=>0,
    -scrollbars=>'e',
    %font,
    %width,
    -height=>43
    )->pack;

my $geom=$mw->geometry;
$geom='+5+5';
$mw->geometry($geom);
    
$mw->after(500,\&handler);

MainLoop;

Kill($pid);

sub enter
    {
    
    print CHILD_IN "$entry_text\n";
    
    $entry_text='';
    
    $entry->focus;
    
    }

sub handler
    {
    
    while(($q->pending)||($qe->pending))
        {
        my ($content,$contente);
        
        if($q->pending)
            {
            $content=$q->dequeue;
            $content=~s/\r//g;
            }
            
        if($qe->pending)
            {
            $contente=$qe->dequeue;
            $contente=~s/\r//g;
            }
            
        my ($x,$y)=$text->yview();
        $text->insert('1.0',"$content$contente");
        $text->yview(moveto=>$x);
        
        $entry->focus;
        }
    
    $mw->after(500,\&handler);
    
    }

sub handle_child_out
{
sleep(1);
do
    {
    
    sysread CHILD_OUT, $content, 4092;
    if($content ne '')
        {
        
        $q->enqueue($content);
        
        }
    
    }
    while(1);
}

sub handle_child_err
{
sleep(1);
do
    {
    
    sysread CHILD_ERR, $content, 4092;
    if($content ne '')
        {
        
        $q->enqueue($content);
        
        }
    
    }
    while(1);
}
[download]

First of all, I don't use MSWindows, but from a casual glance, you are trying to use IPC::Open3 for your pipe, and I don't think it works correctly on windows. See Another Win32 Tk fileevent work around : using ioctl() properly and Please suggest a non-forking way to do this (OS: windows) for starters.

---

I'm not really a human, but I play one on earth.
Old Perl Programmer Haiku ................... flash japh

C:\> help

C:\> help cmd

C:\> help chcp

C:\> perldoc Proc::Background

• help: lists the available dos commands - not helpful
• help cmd: if I use open3 with 'cmd.exe /u' or 'cmd.exe','/u' (for unicode output) it fails
• chcp: what do I do with the number of the code page in a Tk text widget?
• Proc::Background: this part of the problem has been solved already

My question is still: how to convert cmd.exe output into Tk text widget readable format?