1---
2c: Copyright (C) Daniel Stenberg, <daniel.se>, et al.
3SPDX-License-Identifier: curl
4Title: CURLOPT_RESOLVER_START_DATA
5Section: 3
6Source: libcurl
7See-also:
8  - CURLOPT_PREREQFUNCTION (3)
9  - CURLOPT_RESOLVER_START_FUNCTION (3)
10---
11
12# NAME
13
14CURLOPT_RESOLVER_START_DATA - pointer passed to the resolver start callback
15
16# SYNOPSIS
17
18~~~c
19#include <curl/curl.h>
20
21CURLcode curl_easy_setopt(CURL *handle, CURLOPT_RESOLVER_START_DATA,
22                          void *pointer);
23~~~
24
25# DESCRIPTION
26
27Pass a *pointer* is be untouched by libcurl and passed as the third
28argument in the resolver start callback set with
29CURLOPT_RESOLVER_START_FUNCTION(3).
30
31# DEFAULT
32
33NULL
34
35# PROTOCOLS
36
37All
38
39# EXAMPLE
40
41~~~c
42static int resolver_start_cb(void *resolver_state, void *reserved,
43                             void *userdata)
44{
45  (void)reserved;
46  printf("Received resolver_state=%p userdata=%p\n",
47         resolver_state, userdata);
48  return 0;
49}
50
51int main(void)
52{
53  CURL *curl = curl_easy_init();
54  if(curl) {
55    curl_easy_setopt(curl, CURLOPT_RESOLVER_START_FUNCTION, resolver_start_cb);
56    curl_easy_setopt(curl, CURLOPT_RESOLVER_START_DATA, curl);
57    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
58    curl_easy_perform(curl);
59    curl_easy_cleanup(curl);
60  }
61}
62~~~
63
64# AVAILABILITY
65
66Added in 7.59.0
67
68# RETURN VALUE
69
70Returns CURLE_OK
71