sub trim {
   for (my $s = $_[0]) {  # passed param assigned, not used
      s/^\s+//;           # substitutions on $_
      s/\s+$//;
      return $_;
   }
}

##</code><code>##

sub trim {

    my ($string) = @_;

    $string =~ s{ \A \s+ }{}xms;
    $string =~ s{ \s+ \z }{}xms;

    return $string;

    }