Not nicely indented, but close enough:

sub hash_to_html {
  my $x = shift;
  return "" unless ref($x) eq "HASH";
  return "<ul>".join("", map { "<li>$_\n".hash_to_html($x->{$_}) } sor
+t keys %$x  )."</ul>\n";
}
$our_hash = {
    'Cows' => {
        'Brown' => undef,
        'Green' => undef,
        'Strawberry' => {
            'Spotted' => undef,
            'Solid' => undef
        },
        'Orange' => undef
    },
    'Dogs' => {
        'Purple' => {
            'Spotted' => undef,
            'Solid' => undef
        }
    }
};
print hash_to_html($our_hash);
[download]

which generates:

<ul><li>Cows
<ul><li>Brown
<li>Green
<li>Orange
<li>Strawberry
<ul><li>Solid
<li>Spotted
</ul>
</ul>
<li>Dogs
<ul><li>Purple
<ul><li>Solid
<li>Spotted
</ul>
</ul>
</ul>
[download]

-- Randal L. Schwartz, Perl hacker

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