#!/usr/bin/perl

use warnings;
use strict;

use Tk;
my $mw = Tk::MainWindow->new();
$mw->title("Window");
$mw->optionAdd("*font", "Arial 15 normal");
my $text = $mw->Text(-width => 80, -height => 10,
                         -fg => 'black', -bg => 'white');
$text->pack(-padx => 10, -pady => 10);
my $eingabe = $mw->Entry(-width => 60, -fg => 'black', -bg => 'white');
$eingabe->bind("<Return>", sub { processInput($eingabe, $text);} );
$eingabe->focus();
$eingabe->pack(-pady => 10);
$mw->MainLoop();

sub processInput {
    my $eingabe = shift;
    my $text = shift;
    my $s = $eingabe->get();
    $eingabe->delete(0, "end");
    $text->insert("end", "$s\n");
}