#!/usr/bin/perl -w
use Tk;
$main = MainWindow -> new();
$text_box = $main -> Scrolled ("Text",-spacing2=> 1, -spacing3 => 1, 
                           -scrollbars => "e", -height => 20, 
                           -background => "white", -relief => "ridge")->pack();
$start = $main->Button()->pack();
$start-> configure (-text => "Start", -command => [\&count]);
MainLoop();
sub count {
    open(README, "test3.pl |") or die "Can't run program: $!\n";
    while(<README>) {
        $text_box -> insert ("end", $_);
    }
    close(README);
}

##</code><code>##

#!/usr/bin/perl -w
print “Write something: \n”;
while (<>) {
  print;
  if ($_ =~ /aaa/){
  exit;
  }
}