Editing URL redirection (section)

==== nginx rewrite ====
[[Nginx]] has an integrated http rewrite module,<ref name="T6lN6" /> which can be used to perform advanced URL processing and even web-page generation (with the <code>return</code> directive).  An example of such advanced use of the rewrite module is mdoc.su, which implements a deterministic [[URL shortening]] service entirely with the help of nginx configuration language alone.<ref name="ltnoQ" /><ref name="sjHzb" />

For example, if a request for <code>[https://www.dragonflybsd.org/cgi/web-man?command=HAMMER&section=5 /DragonFlyBSD/HAMMER.5]</code> were to come along, it would first be redirected internally to <code>/d/HAMMER.5</code> with the first rewrite directive below (only affecting the internal state, without any HTTP replies issued to the client just yet), and then with the second rewrite directive, an [[HTTP response]] with a [[HTTP 302|302 Found status code]] would be issued to the client to actually redirect to the external [[Common Gateway Interface|cgi script]] of web-[[man page|man]]:<ref name="y0ZUF" />
<syntaxhighlight lang="nginx">
 location /DragonFly {
  rewrite ^/DragonFly(BSD)?([,/].*)?$ /d$2 last;
 }
 location /d {
  set $db "https://leaf.dragonflybsd.org/cgi/web-man?command=";
  set $ds "&section=";
  rewrite ^/./([^/]+)\.([1-9])$  $db$1$ds$2 redirect;
 }
</syntaxhighlight>