%volume
%mnt
%device
%perms
%user
%mntops
%other

##</code><code>##

sub traverse_hash {
    my ($jsonhash, $found, @keys_to_find) = @_;
    my $results = 'results.txt';


    open(FILE, ">>$results");

    for my $key (sort keys %{$jsonhash}) {
        my $keyvalue = $jsonhash->{$key};
        
        if ('HASH' eq ref $keyvalue) {
            $found = {%$found, %{ traverse_hash($keyvalue, $found, @keys_to_find) }};
        }
        for my $find (@keys_to_find) {
            if ($key eq $find) {
                if ('HASH' eq ref $keyvalue) {
                    $found->{$key} = [ map $keyvalue->{$_}, sort keys %$keyvalue ];
                } else {
                    $found->{$key} = $keyvalue;
                }
            } 
        }
    }    
    if (@keys_to_find == keys %$found) {
        my $count;
        $count = @{ (grep 'ARRAY' eq ref $_, values %$found)[0] // [] };
        $count ||= 1;
        for my $i (0 .. $count - 1) {
            print FILE join(':', map { 'ARRAY' eq ref $_ ? $_->[$i] : $_ } @{$found}{@keys_to_find}), "\n";
        }
        $found = {};
    }
    return $found;
    close(FILE);
}


##</code><code>##

$output_format = '%mnt:%device:%volume:%perms';

##</code><code>##

traverse_hash(\%$decoded_json_obj, {}, @keys_to_find, $output_format);