$sub_pid= open $pipe, "-|", "${tab}_${date}.sh 2>&1" or die "Can't execute $tab : $!\n";

##</code><code>##

my $button = $popup->Button(
      -text => 'Kill',
      -command => [sub{`kill $sub_pid 2>&1` && warn "Can't kill subprocess: $sub_pid\n"}],-background=>'slate grey');
  $button->pack;