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