# Convert the decimal to hexadecimal and pad the result with a lea
+ding
    # zero if needed.
    my $hex = sprintf("%x", $dec);
    $hex = length( $hex ) == 1 ? "0".$hex : $hex;

##</code><code>##

    my $hex = sprintf '%02x', $dec;

##</code><code>##

sub basicSNTPSetup {
  ...   
  sub keyDifference {
    ..
  };
};

##</code><code>##

sub basicSNTPSetup {
  ...   
};

sub keyDifference {
  ..
};

##</code><code>##

my $verify_port = sub {
  my $port = shift;
  if ( defined $port && $port =~ /^[0-9]+$/ ) {
    if ( $port >= MIN_UDP_PORT || $port <= MAX_UDP_PORT ) {
      return FALSE;
    }
  }
  return TRUE;
};

##</code><code>##

sub verify_port {
  ...
};

##</code><code>##

  if ( $port >= MIN_UDP_PORT || $port <= MAX_UDP_PORT ) {

##</code><code>##

either:
  if ( ($port >= MIN_UDP_PORT) && ($port <= MAX_UDP_PORT) ) {
or:
  if ( $port >= MIN_UDP_PORT and $port <= MAX_UDP_PORT ) {