use warnings;
use strict;

my %hash = (
    '-P'                      => 'hostPassword',
    'alternate_param_options' => [
        'all', 'objects',
        {'-H' => ['hosting-storage-system', 'vfiler'], '-S' => ['saf']}, undef
        ],
    'single_switches' => ['-N'],
    'mandatory'       => ['end'],
    '-U'              => 'hostLogin'
    );


delve (\%hash);


sub delve {
    my ($ref, $key) = @_;
    
    if ('ARRAY' eq ref $ref) {
        for my $element (@$ref) {
            if ($key) {
                delve ($element, $key); 
            } elsif (ref $element) {
                delve ($element)
            }
        }
        
        return;
    }
    
    if ('HASH' eq ref ($ref)) {
        for my $nestedKey (keys %$ref) {
            my $value = $ref->{$nestedKey};
            
            if ($nestedKey =~ /^-/) {
                delve ($value, $nestedKey)
            } else {
                delve ($value, $key)
            }
        }
        
        return;
    }
    
    return if ref $ref; # Some other reference type - ignore it
    
    if ($key) {
        printf "%22s: %s\n", $ref, $key;
    }
}