curl-w32/docs/libcurl/opts/CURLOPT_DNS_INTERFACE.md

c	SPDX-License-Identifier	Title	Section	Source	See-also
Copyright (C) Daniel Stenberg, <daniel.se>, et al.	curl	CURLOPT_DNS_INTERFACE	3	libcurl	CURLOPT_DNS_LOCAL_IP4 (3) CURLOPT_DNS_LOCAL_IP6 (3) CURLOPT_DNS_SERVERS (3) CURLOPT_INTERFACE (3)

NAME

CURLOPT_DNS_INTERFACE - interface to speak DNS over

SYNOPSIS

#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

All protocols except file:// - protocols that resolve host names.

EXAMPLE

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);
  }
}

AVAILABILITY

Added in 7.33.0. This option also requires that libcurl was built with a resolver backend that supports this operation. The c-ares backend is the only such one.

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.