sub hash_walk {
    my ($hash, $string, $level, %keys_printed) = @_;
    while (my ($k, $v) = each %$hash) {
      $string .= "{ $k: " unless $keys_printed{$level}{$k};
      $keys_printed{$level}{$k} = 1;
      if (ref($v) eq 'HASH') {
        $string = hash_walk($v, $string, ++$level, %keys_printed);
        $string .= ' }, ';
        $level--;
      } else {
        $string .= $v . ' },';
      }

    }
    return $string;
}

my %data = (
  email =>{steve => 'owens'},
  user => {steve => {fun => 'times', laugh => 'in'}},
  pass => {blah => 'moomoo'},
);

print hash_walk(\%data, '', 0, ()) . "\n";