GNURLOPT_DNS_INTERFACE(3)

💖 NAME 💖

Okay bestie, welcome to GNURLOPT_DNS_INTERFACE(3) from the curl_easy_setopt options manual — this is the page about setting the interface your DNS resolver should speak over. The actual option name is CURLOPT_DNS_INTERFACE, and it's giving “tell DNS to bind to this network interface” energy. ✨

🎀 SYNOPSIS 🎀

#include <gnurl/curl.h>

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

🌸 DESCRIPTION 🌸

You pass a char * as the parameter, bestie — literally that's the move. Set it to the name of the network interface that the DNS resolver should bind to.

Important vibe check: this must be an interface name (not an address). So like, the name, not the IP. No cap. 💅

Set this option to NULL to use the default setting (don't bind to a specific interface). Easy.

And good news for your app: the application does not have to keep the string around after setting this option. Set it and move on. 🫶

⭐ DEFAULT ⭐

NULL

🦋 PROTOCOLS 🦋

There's literally nothing listed in this section on the original page, so no protocol list to show you here, bestie. That's the whole section. 💀

🔥 EXAMPLE 🔥

Here's the example, exactly as the page gives it:

CURL *curl = curl_easy_init();
if(curl) {
  curl_easy_setopt(curl, CURLOPT_URL, "http://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. So yeah — backend check first, bestie. ✨

🌈 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. That's the whole return-value menu. 💅

🎀 SEE ALSO 🎀

• CURLOPT_DNS_SERVERS(3),
• CURLOPT_DNS_LOCAL_IP4(3),

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Later, bestie! This page is from libcurl 7.37.0, dated 19 Jun 2014, and it's the GNURLOPT_DNS_INTERFACE(3) page. Mwah! 💋