CURLINFO_CONTENT_LENGTH_DOWNLOAD - Man Page

#include <curl/curl.h>

CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_CONTENT_LENGTH_DOWNLOAD,
                           double *content_length);

Pass a pointer to a double to receive the content-length of the download. This is the value read from the Content-Length: field. This returns -1 if the size is not known.

CURLINFO_CONTENT_LENGTH_DOWNLOAD_T(3) is a newer replacement that returns a more sensible variable type.

This functionality affects all supported protocols

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");

    /* Perform the request */
    res = curl_easy_perform(curl);

    if(!res) {
      /* check the size */
      double cl;
      res = curl_easy_getinfo(curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &cl);
      if(!res) {
        printf("Size: %.0f\n", cl);
      }
    }
  }
}

Deprecated since 7.55.0.

Added in curl 7.6.1

curl_easy_getinfo(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors(3).

CURLINFO_CONTENT_LENGTH_UPLOAD(3), curl_easy_getinfo(3), curl_easy_setopt(3)

curl_easy_getinfo(3).