NAME

       CURLOPT_RESOLVER_START_DATA - pointer passed to the resolver start callback

SYNOPSIS

       #include <curl/curl.h>

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

DESCRIPTION

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

DEFAULT

       NULL

PROTOCOLS

       This functionality affects all supported protocols

EXAMPLE

       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;
       }

       int main(void)
       {
         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);
         }
       }

AVAILABILITY

       Added in curl 7.59.0

RETURN VALUE

       curl_easy_setopt(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).

SEE ALSO

       CURLOPT_PREREQFUNCTION(3), CURLOPT_RESOLVER_START_FUNCTION(3)

libcurl                                            2025-03-05                     CURLOPT_RESOLVER_START_DATA(3)