curl/docs/libcurl/opts/CURLOPT_DNS_INTERFACE.md
Daniel Stenberg 5a488251f7
curldown: fixups
- make DEFAULT sections less repetitive

- make historic mentions use HISTORY

- generate the protocols section on `# %PROTOCOLS%` instead of guessing
  where to put it

- generate the availability section on `# %AVAILABILITY%` instead of
  guessing where to put it

- make the protocols section more verbose

Closes #14227
2024-07-19 17:03:25 +02:00

71 lines
1.5 KiB
Markdown

---
c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
SPDX-License-Identifier: curl
Title: CURLOPT_DNS_INTERFACE
Section: 3
Source: libcurl
See-also:
- CURLOPT_DNS_LOCAL_IP4 (3)
- CURLOPT_DNS_LOCAL_IP6 (3)
- CURLOPT_DNS_SERVERS (3)
- CURLOPT_INTERFACE (3)
Protocol:
- All
Added-in: 7.33.0
---
# NAME
CURLOPT_DNS_INTERFACE - interface to speak DNS over
# SYNOPSIS
~~~c
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DNS_INTERFACE, char *ifname);
~~~
# DESCRIPTION
Pass a char pointer as parameter. Set the name of the network interface that
the DNS resolver should bind to. This must be an interface name (not an
address). Set this option to NULL to use the default setting (do not bind to a
specific interface).
The application does not have to keep the string around after setting this
option.
# DEFAULT
NULL
# %PROTOCOLS%
# EXAMPLE
~~~c
int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
CURLcode res;
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");
curl_easy_setopt(curl, CURLOPT_DNS_INTERFACE, "eth0");
res = curl_easy_perform(curl);
curl_easy_cleanup(curl);
}
}
~~~
# NOTES
This option requires that libcurl was built with a resolver backend that
supports this operation. The c-ares backend is the only such one.
# %AVAILABILITY%
# RETURN VALUE
Returns CURLE_OK if the option is supported, CURLE_UNKNOWN_OPTION if not,
or CURLE_NOT_BUILT_IN if support was disabled at compile-time.