How to pass fastcgi custom variables in C?

[nginxuser100]

Hi, I would like to have the auth_request fastcgi auth server to send some
custom variables to the fastcgi back-end server. For example, the Radius
server returned some parameters which the fastcgi auth server needs to send
to the fastcgi back-end server.

locate / {
       auth_request /auth;
       fastcgi_pass   <back-end server>;  <--- would like this server to see
the custom param variable
 }

locate /auth {
      fastcgi_param CUSTOM_PARAM custom_param;
      fastcgi_pass <auth server>; <---- returns a custom param value to be
used by the back-end server
}

Could someone give me a pointer on how to this in the nginx.conf and the
auth and back-end servers in C? I saw many examples for PHP but none for C.

In the auth server app, I defined "int custom_param=100" for example, and
would like the back-end server to see get this variable and value. Thanks!

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,256237,256237#msg-256237