#!/usr/bin/perl -w
open FH, '>foobar';
print FH pack 'H2H2H2H2',  'ab','cd','ef','00';
print FH pack 'H8','abcdef00';
print FH pack 'H2'x 4, 'ab', 'cd', 'ef', '00';
print `hd "foobar"`,"\n";

##</code><code>##

00000000  ab cd ef 00 ab cd ef 00  ab cd ef 00                                 
0000000C