# assuming -T
   ...
   my $param_cmd = param( 'trace' );
   if ( $param_cmd ) and ( $param_cmd =~ /^[-.0-9a-zA-Z]+$/ )
   {
      $param_cmd = $1;
      print p( "Hello There- I am writing this from " 
               . "scratch so please be patient. Thanks!" ), 
               "<pre>"; 
        
      system( "/usr/sbin/traceroute", $param_cmd ); 
      ...
   }