DOKK / manpages / debian 12 / libcurl4-doc / CURLOPT_IPRESOLVE.3.en
CURLOPT_IPRESOLVE(3) curl_easy_setopt options CURLOPT_IPRESOLVE(3)

CURLOPT_IPRESOLVE - IP protocol version to use

#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_IPRESOLVE, long resolve);

Allows an application to select what kind of IP addresses to use when establishing a connection or choosing one from the connection pool. This is interesting when using host names that resolve addresses using more than one version of IP. The allowed values are:

Default, can use addresses of all IP versions that your system allows.
Uses only IPv4 addresses.
Uses only IPv6 addresses.

CURL_IPRESOLVE_WHATEVER

All

CURL *curl = curl_easy_init();
if(curl) {

curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin");
/* of all addresses example.com resolves to, only IPv6 ones are used */
curl_easy_setopt(curl, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V6);
ret = curl_easy_perform(curl);
curl_easy_cleanup(curl); }

Always

Returns CURLE_OK

CURLOPT_HTTP_VERSION(3), CURLOPT_SSLVERSION(3),

January 2, 2023 libcurl 7.88.1