Question

I’ve really searched this. I’ve seen examples of how you can download and write data to a file with libcurl but I don’t know how to write them to an array

that’s the code I have so far:

static size_t write_data(void *ptr, size_t size, size_t nmemb, void *stream)
{

int written = fwrite(ptr, size, nmemb, (FILE *)stream);
return written;
}

int main(void)
{
CURL *curl_handle;
FILE *bodyfile;
static const char *headerfilename = "head.out";
FILE *headerfile;
static const char *bodyfilename = "body.out";

curl_global_init(CURL_GLOBAL_ALL);

/* init the curl session */
curl_handle = curl_easy_init();

/* set URL to get */
curl_easy_setopt(curl_handle, CURLOPT_URL,"http://example.com/");
/* no progress meter please */
curl_easy_setopt(curl_handle, CURLOPT_NOPROGRESS, 1L);

/* send all data to this function  */
curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, write_data);

/* open the files */
headerfile = fopen(headerfilename,"w");
if (headerfile == NULL) {
    curl_easy_cleanup(curl_handle);
    return -1;
}
bodyfile = fopen(bodyfilename,"w");
if (bodyfile == NULL) {
    curl_easy_cleanup(curl_handle);
    return -1;
}

/* we want the headers to this file handle */
curl_easy_setopt(curl_handle,   CURLOPT_WRITEHEADER, headerfile);

/* we want the body to this file handle */
curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, bodyfile);

/* get it! */
curl_easy_perform(curl_handle);

/* close the header file */
fclose(headerfile);
fclose(bodyfile);
return 0;
}

Answer 1

It seems, what you need is described in the libcurl documentation:

CURLOPT_WRITEFUNCTION

Function pointer that should match the following prototype: size_t
function( char *ptr, size_t size, size_t nmemb, void *userdata); This
function gets called by libcurl as soon as there is data received that
needs to be saved. […]

That is you have to implement a function with the signature

size_t my_array_write(char *ptr, size_t size, size_t nmemb, void *userdata);

And pass it to curl:

curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, my_array_write);

However, I haven’t tested it (and I am not aware of a simpler way to achieve this). See the libcurl docs for more information.