nginx URL rewrite using negative regex?

Question

I\'m trying to redirect requests to https in nginx, unless it is of the form HOST/ANY_STRING_OF_CHARS/END_OF_URI, e.g.:

http://host.org/about # no redirect<

Answer 1

set $test "0";
if ($request_uri ~ "condition") {
   set $test "1";
}
if ($test ~ "0") {
   return 301 redirect url;
}