#!/usr/bin/perl
use strict;
use Getopt::Std::Strict 'dh';

INIT {
   $SIG{__WARN__} = 
      $opt_d ? sub { warn(" # @_\n") } : sub { 1 };
   $opt_h and print usage() and exit;
}

warn "Hi there. I am stuff, very interersting stuff.";

sub usage { "-d flag to see interesting stuff\n" }