open(FILE, ">>$path") or die "$! writing $path";
  &lock;  # calls flock(FLOCK_EX) and logs
  print FILE $string;
  &unlock; # calls flock(FLOCK_UN) and logs
  close FILE;

##</code><code>##

  open(FILE, ">>$path") or die "$! writing $path";
  &lock;
  seek(FILE, 0, 2);  # ensure positioned at EOF
  print FILE $string;
  ...