sub trim {
  if (defined my $w = wantarray) {
    @_ = ( @_ ? @_ : $_ );
    for (@_) { s/^\s+//, s/\s+$// if $_ }
    return $w ? @_ : $_[0];
  }
  else {
    for (@_ ? @_ : $_) { s/^\s+//, s/\s+$// if $_ }
  }
}