my $progname = 'emacs';
my $label = "_by_" . $$;
my $proglabel = $progname . $label;

my @args = ( $0 );

if ( my $pid = fork ) { 
  # this is parent code
  # pause, then zap the child
  sleep 10;
  my @lines = grep{ m/$label/ } qx{ ps axw };
  my @pids = map{ ( split " ", $_ )[0] } @lines;
  foreach my $pid ( @pids ) {
    my $status =
      kill 1, $pid;
    ($DEBUG) && print STDERR "Tried to kill (1) pid $pid, status: $status \n";
  }
} else { 
   # this is child code
  die "cannot fork: $!" unless defined $pid;
  exec { $progname } ( $proglabel, @args );
}