sub print_hash
{
	my ( $prefix, $href ) = @_;

	while ( my ( $key, $val ) = each %$href )
	{
		if ( ref $val )
		{
			print_hash( "$prefix$key\t", $val );
		}
		else
		{
			print "$prefix$key\t$val\n";
		}
	}
}

my %hh = (
	key1 => {
		key2 => 'abc',
		key3 => {
			keymany => 'value'
		}
	},
	key11 => {
		key22 => 'def',
	}
);

print_hash( "", \%hh );

exit 0;