Your "program" is a Perl function. Can it be an independent script? If so, you could spawn a thread to act as a bridge. 

use IPC::Open3 qw( open3 );

sub run_child { 
   my ($widget) = @_;

   my $pid = open3(
      my $to_child,   # Autovivified when false.
      my $fr_child,   # Autovivified when false.
      undef,          # Same as $fr_child when false.
      $somecommand,
      @args
   );

   while (<$fr_child>) {
      my $end_is_visible = ( $yview == 1.0 );
      $text->insert('end', $_);
      $w->see('end') if $end_is_visible;
   }

   waitpid($pid, 0);
}

[download]

And I have no idea how Tk will react to threads, especially when calling a $widget method from a separate thread.

In reply to Re: Please suggest a non-forking way to do this (OS: windows) by ikegami
in thread Please suggest a non-forking way to do this (OS: windows) by cranky

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