use Wx::Perl::ProcessStream qw( :everything );

# setup the stream handlers
     
EVT_WXP_PROCESS_STREAM_STDOUT    ( wxperl_window, \&evt_process_stdout_err );
EVT_WXP_PROCESS_STREAM_STDERR    ( wxperl_window, \&evt_process_stdout_err );
EVT_WXP_PROCESS_STREAM_EXIT      ( wxperl_window, \&evt_process_exit   );
EVT_WXP_PROCESS_STREAM_MAXLINES  ( wxperl_window, \&evt_process_maxlines  );

the handlers (here both the childs stdout & sterr are handled in the same handler)

sub evt_process_stdout_err
{
   my( $self, $event ) = @_;

   $event->Skip(1);
   my $process = $event->GetProcess;
   my $clientline = $event->GetLine;
   $clientline=~s/"//g;
   $clientline=~s/\s+$//g;
   # string off all quotes and trailing whitespace
   # show it in the test window
   $detailsInfo->AppendText("$clientline\n");
   # if the output line ends with identified line end, then it is about to be a prompt
   if ($clientline=~m/($specialeol)$/) 
   {
      my $textvalue =  Wx::GetTextFromUser($clientline, "pre exit prompt", "",$self) ;
      $process->WriteProcess("$textvalue\n");
   }

}
sub evt_process_exit
{
        my ($self, $event) = @_;
        $event->Skip(1);
        my $process = $event->GetProcess;
        my $line = $event->GetLine;
        my @buffers = @{ $process->GetStdOutBuffer };
        my @errors = @{ $process->GetStdErrBuffer };
        my $exitcode = $process->GetExitCode;
        $process->Destroy;
}

the startup (this replaces all the thread goo)
        my $proc1 = Wx::Perl::ProcessStream::Process->new($command, 'somelabel', wxperl_window)->Run;