Manpages - CURLOPT_RESOLVER_START_DATA.3

CURLOPT_RESOLVER_START_DATA - pointer passed to the resolver start callback

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_RESOLVER_START_DATA, void *pointer);

Pass a pointer that will be untouched by libcurl and passed as the third argument in the resolver start callback set with CURLOPT_RESOLVER_START_FUNCTION(3).

NULL

All

  static int resolver_start_cb(void *resolver_state, void *reserved,
                               void *userdata)
  {
    (void)reserved;
    printf("Received resolver_state=%p userdata=%p\n",
           resolver_state, userdata);
    return 0;
  }

  CURL *curl = curl_easy_init();
  if(curl) {
    curl_easy_setopt(curl, CURLOPT_RESOLVER_START_FUNCTION, resolver_start_cb);
    curl_easy_setopt(curl, CURLOPT_RESOLVER_START_DATA, curl);
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
    curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }

Added in 7.59.0

Returns CURLE_OK

*CURLOPT_RESOLVER_START_FUNCTION*(3)