Controller: partial retrieving of configuration.

src/nxt_conf.h

@@ -18,6 +18,8 @@ typedef struct {
 } nxt_conf_json_pretty_t;
 
 
+nxt_conf_json_value_t *nxt_conf_json_value_get(nxt_conf_json_value_t *value,
+    nxt_str_t *path);
 nxt_conf_json_value_t *nxt_conf_json_parse(u_char *pos, size_t length,
     nxt_mem_pool_t *pool);
 uintptr_t nxt_conf_json_print_value(u_char *pos, nxt_conf_json_value_t *value,