Как в коде C получитъ значение переменной из конфигурационного ?

I need get variable value "redis key" in C code that would then poison redis server using posix sockets. How can I do it ? Here's my nginx config file
Мне надо в коде С получить/читатъ значение переменной redis_key, что бы отправишъ по сокету редис серверу. Как это сделатъ ?

Вот мой конфиг файл

server {                                                                
                 listen       80;                                                  
                 server_name  localhost;                                          
                 error_log /var/log/nginx-error.log debug;                        
                 access_log /var/log/nginx_access.log;                            

                 location / {                                                      
                          set $redis_key  "$uri?$args";                            
                          echo "REDIS_____KEY: $redis_key";                        
                          redis_pass      127.0.0.1:6379;                          
                          error_page      404 502 504 = @fallback;                
                  }                                                                

                  location @fallback {                                            
                          proxy_pass http://127.0.0.1:6379;      &n...
                  }                                                                
          }