CURLOPT_DNS_INTERFACE

Section: curl_easy_setopt options (3)
Updated: November 04, 2020
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NAME

CURLOPT_DNS_INTERFACE - set interface to speak DNS over

SYNOPSIS

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DNS_INTERFACE, char *ifname);

DESCRIPTION

Pass a char * 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 (don't bind to a specific interface).

The application does not have to keep the string around after setting this option.

DEFAULT

NULL

PROTOCOLS

EXAMPLE

CURL *curl = curl_easy_init();
if(curl) {
  curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");
  curl_easy_setopt(curl, CURLOPT_DNS_INTERFACE, "eth0");
  ret = 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.