API V2 oauth 1.0

Thanks for your answer.  and I have another question about API V2 oauth 2.0.

I use c++ code to upload files, but how can I get access token by http request with API V2 , eg:

https://www.dropbox.com/oauth2/authorize

https://api.dropboxapi.com/oauth2/token

c++ code :

#include <stdio.h>
#include <curl/curl.h>

int main (int argc, char *argv[])
{
      CURL *curl;
      CURLcode res;

      /* In windows, this will init the winsock stuff */
      curl_global_init(CURL_GLOBAL_ALL);

      /* get a curl handle */
      curl = curl_easy_init();
      if(curl) {

            printf ("Running curl test.\n");

            struct curl_slist *headers=NULL; /* init to NULL is important */
            headers = curl_slist_append(headers, "Authorization: Bearer <ACCESS_TOKEN>");
            headers = curl_slist_append(headers, "Content-Type: application/octet-stream");
            headers = curl_slist_append(headers, "Dropbox-API-Arg: {\"path\":\"/test_c++_upload_test.txt\"}");
            curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);

            curl_easy_setopt(curl, CURLOPT_URL, "https://content.dropboxapi.com/2/files/upload");
            curl_easy_setopt(curl, CURLOPT_POSTFIELDS, "test data for upload");

            /* Perform the request, res will get the return code */
            res = curl_easy_perform(curl);
            /* Check for errors */
            if(res != CURLE_OK)
                  fprintf(stderr, "curl_easy_perform() failed: %s\n",
                    curl_easy_strerror(res));

            /* always cleanup */
              curl_easy_cleanup(curl);

              printf ("\nFinished curl test.\n");

      }
      curl_global_cleanup();

      printf ("Done!\n");
      return 0;

}