Use $ args in Nginx rewrite to cause duplicate URL parameters

rewrite ^ $topicredirecturi?$args permanent ;

http://www.topics.com/companies/cit-group- inc/index.html

http://www.topics.com/companies/cit_group_inc/index.html

http://www.topics.com/companies/cit-group-inc/index.html?rss= 1

http://www.topics.com/companies/cit_group_inc/index. html?rss=1&rss=1

http://www.topics.com/companies/cit-group-inc/index .html?rss=1&bob=2

http://www.topics.com/companies/cit_group_inc/index.html? rss=1&bob=2&rss=1&bob=2

rewrite ^(...)$/destination$is_args$args? [permanent|redirect];

In one of my location rules , I tried to rewrite the URL:

rewrite ^ $topicredirecturi?$args permanent;

$topicredirecturi is calculated in the mapping file, mapping for example URL etc.

http://www.topics.com/companies/cit-group-inc/index.html

to

< p>

http://www.topics.com/companies/cit_group_inc/index.html

When I make a request using URL parameters, for example:

http://www.topics.com/companies/cit-group-inc/index.html?rss=1

I get the following rewrite with duplicate parameters URL:

http://www.topics.com/companies/cit_group_inc/index.html?rss=1&rss=1

Similarly, URL< /p>

http://www.topics.com/companies/cit-group-inc/index.html?rss=1&bob=2

is rewritten as

http://www.topics.com/companies/cit_group_inc/index.html?rss=1&bob=2&rss=1&bob=2

Does anyone know What will happen here?

@Yirkha answer is wrong. Nginx does not automatically append the query string, but only appends if there are other get parameters in the rewritten URL .If you add $args yourself, should you add one? (Question mark) at the end of the rewritten URL to avoid duplicate parameters.

The correct way to redirect using a query string is:

rewrite ^(...)$/destination$is_args$args? [permanent|redirect];

What does $is_args contain? The iff query string is not empty, and $args is the query string itself; the final question mark requests that nginx no longer add the query string.