Thanks again! I'll take a look at that. Meanwhile, further work with your original suggestion has produced something like this (not complete): 

my $Q = new Thread::Queue;
my $mw = MainWindow->new();

my $run_button = $mw -> Button(-text => "Run Programs",
-command=> sub { threads->create(\&runprogs, $Q)->detach(); &view_out;
+ });

sub runprogs
{
  # run the main script 
  my $pipe = IO::Pipe->new();
  $pipe->reader("$script $args 2>&1");
  $Q->enqueue( $_ ) while <$pipe>;
  $Q->enqueue ( undef );
  sleep;
}

sub view_out
{
  # create display window
  my $top = $mw-> Toplevel();
  my $label = $top -> Label(-text=>"Script output",-relief=>"groove")-
+>pack();
  my $ro = $top->Scrolled('ROText', -width => 60, -height=>20, -scroll
+bars=>"e")->pack();
  # continuously display output
  while (my $thingy = $Q->dequeue_nb())
  {
    last unless (defined $thingy);
    $ro->insert("end", "$thingy");
    $ro->update();
    sleep 1;
  }
  # add close button
  my $close = $top -> Button(-text=>"Close window", -command => sub { 
+destroy $top; })->pack();
}

[download]

This works, but if I omit the "sleep" from &runprogs, or have a return in there then all manner of horrible things happen. Presumably this is because I have misunderstood how this all works and cocked up the queueing somehow.

In reply to Re^4: Tk + threads by knirirr
in thread Tk + threads by knirirr

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