if (length($string) > 15) {
  $string =~ s/^(.{0,12})\b\s.*/$1.../gi;
}

##</code><code>##

if (length($string) > 15) {
  unless ($string =~ s/^(.{0,12})\b\s.*/$1.../gi) {
    $string = substr ($string, 0, 12) . '...';
  }
}