I'm a big fan of .ini files because they're human readable, and also very machine readable. I wrote a quick function to convert a hashref to a simple .ini string.

my $str = hash_to_ini({ data => { 'name' => 'scott', animal => 'dog' }});

sub hash_to_ini {
    my $x   = $_[0];
    my $ret = '';

    foreach my $key (sort(keys(%$x))) {
        my $val = $x->{$key};

        if (ref($val) eq "HASH") {
            $ret .= "[$key]\n";
            foreach my $k (sort(keys(%$val))) { $ret .= "$k = " . $val->{$k} . "\n"; }
        } else { $ret .= "$key = $val\n" }
    }

    $ret =~ s/\n\[/\n\n[/; # Add a space between sections
    return $ret;
}

I also wrote a version in PHP

function hash_to_ini($x) {
    $ret = '';

    foreach (array_keys($x) as $key) {
        $val = $x[$key];

        if (is_array($val)) {
            $ret .= "[$key]\n";
            foreach (array_keys($val) as $k) { $ret .= "$k = " . $val[$k] . "\n"; }
        } else { $ret .= "$key = $val\n"; }
    }

    $ret = preg_replace("/\n\[/", "\n\n[", $ret);
    return $ret;
}

Note: see also parse_ini()

This syntax still doesn't make much sense to me but here is how you sort a perl hash by value. This returns a list of all the keys of the hash sorted in the order you want. To reverse the sort simply change $a and $b locations with each other.

my @sort = sort{ $unique{$a} <=> $unique{$b} } keys %unique;