Downloading a file via curl in c++ from dropbox

Question

I want to download a file from a dropbox shared link using curl in a c++ program

I found a dropbox api pdf that showed me how to do it

#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:");
     headers = curl_slist_append(headers, "Dropbox-API-Arg: 
     {\"path\":\"/test.txt\"}");
     curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
    curl_easy_setopt(curl, CURLOPT_URL,
    "https://content.dropboxapi.com/2/files/download");
     curl_easy_setopt(curl, CURLOPT_POSTFIELDS, "");
     /* 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;
         }

However, the comments supplied don't offer much explanation for me, and I can't get it to work.

I don't understand these three lines of code:

headers = curl_slist_append(headers, "Authorization: Bearer <ACCESS_TOKEN>");

headers = curl_slist_append(headers, "Content-Type:");

headers = curl_slist_append(headers, "Dropbox-API-Arg:{\"path\":\"/test.txt\"}");

I think I have to replace some stuff but I don't know what

Answer 1

"I think I have to replace some stuff but I don't know what" : Replace <ACCESS_TOKEN> with your actual access token.

You should also set the "Content-Type:" header to an appropriate value for the data you are fetching.

You must also change the value of the "Dropbox-API-Arg" header to match the file you are trying to get.