sub multi_key_sort {  # pass me two references to arrays
 my $array = shift;   # the first to the array that needs sorting..
 my $keys = shift;    # the second to an array of keys to sort by
 for my $key (@$keys) {
   @$array = sort {$$a{$key} cmp $$b{$key}} @$array;
 }
 return @$array;
}

my @sorted_array = &multi_key_sort(\@unsorted_array,\@array_of_keys);
# @array_of_keys in order from least to most signifigant