CURLOPT_RESOLVER_START_DATA(3) Introduction to Library Functions

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 2025-02-25 CURLOPT_RESOLVER_START_DATA(3)