#! /usr/bin/perl

use strict;
use warnings;
use diagnostics;

use Tk;

my $mw = MainWindow->new();
my $liste = $mw->ScrlListbox(-label => "Liste",
                                           -selectmode => "extended",
		           -height => 6,
		           -exportselection => 0)->pack();

my $startButton = $mw -> Button(-text => "start", -command => \&write_file)->pack();
&fill_list();

MainLoop;

sub fill_list{
  my $file = '/Pfad/zur/Datei.txt';
  open(DATEI,"<$file") or die $!;
  while(my $line = <DATEI>){
    chomp $line;
    $liste->insert("end",$line);
  }
  close DATEI;
}

sub write_file{
  my $file = '/Pfad/zur/Zieldatei.txt';
  my @sel_items = $liste->Getselected(); 
  open(WRITE,">$file") or die $!;
  for(@sel_items){
    print WRITE $_,"\n";
  }
  close WRITE;
}