Manpages - CURLINFO_HEADER_SIZE.3

CURLINFO_HEADER_SIZE - get size of retrieved headers

#include <curl/curl.h>

CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_HEADER_SIZE, long *sizep);

Pass a pointer to a long to receive the total size of all the headers received. Measured in number of bytes.

The total includes the size of any received headers suppressed by CURLOPT_SUPPRESS_CONNECT_HEADERS(3).

All

  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
    res = curl_easy_perform(curl);
    if(res == CURLE_OK) {
      long size;
      res = curl_easy_getinfo(curl, CURLINFO_HEADER_SIZE, &size);
      if(!res)
        printf("Header size: %ld bytes\n", size);
    }
    curl_easy_cleanup(curl);
  }

Added in 7.4.1

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

*curl_easy_getinfo*(3), *curl_easy_setopt*(3), *CURLINFO_REQUEST_SIZE*(3), *CURLINFO_SIZE_DOWNLOAD*(3),