1---
2c: Copyright (C) Daniel Stenberg, <daniel.se>, et al.
3SPDX-License-Identifier: curl
4Title: CURLOPT_DNS_SERVERS
5Section: 3
6Source: libcurl
7See-also:
8  - CURLOPT_DNS_CACHE_TIMEOUT (3)
9  - CURLOPT_DNS_LOCAL_IP4 (3)
10  - CURLOPT_DNS_LOCAL_IP6 (3)
11---
12
13# NAME
14
15CURLOPT_DNS_SERVERS - DNS servers to use
16
17# SYNOPSIS
18
19~~~c
20#include <curl/curl.h>
21
22CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DNS_SERVERS, char *servers);
23~~~
24
25# DESCRIPTION
26
27Pass a char pointer that is the list of DNS servers to be used instead of the
28system default. The format of the dns servers option is:
29
30host[:port][,host[:port]]...
31
32For example:
33
34192.168.1.100,192.168.1.101,3.4.5.6
35
36The application does not have to keep the string around after setting this
37option.
38
39# DEFAULT
40
41NULL - use system default
42
43# PROTOCOLS
44
45All
46
47# EXAMPLE
48
49~~~c
50int main(void)
51{
52  CURL *curl = curl_easy_init();
53  if(curl) {
54    CURLcode res;
55    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");
56    curl_easy_setopt(curl, CURLOPT_DNS_SERVERS,
57                     "192.168.1.100:53,192.168.1.101");
58    res = curl_easy_perform(curl);
59    curl_easy_cleanup(curl);
60  }
61}
62~~~
63
64# AVAILABILITY
65
66This option requires that libcurl was built with a resolver backend that
67supports this operation. The c-ares backend is the only such one.
68
69Added in 7.24.0
70
71# RETURN VALUE
72
73Returns CURLE_OK if the option is supported, CURLE_UNKNOWN_OPTION if not,
74CURLE_NOT_BUILT_IN if support was disabled at compile-time,
75CURLE_BAD_FUNCTION_ARGUMENT when given an invalid server list, or
76CURLE_OUT_OF_MEMORY if there was insufficient heap space.
77