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