Tribblix: manual page: CURLOPT

CURLOPT_IPRESOLVE(3) Introduction to Library Functions CURLOPT_IPRESOLVE(3)

NAME

CURLOPT_IPRESOLVE - IP protocol version to use

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_IPRESOLVE, long resolve);

DESCRIPTION

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 hostnames that resolve to more than
one IP family.

If the URL provided for a transfer contains a numerical IP version as
a host name, this option does not override or prohibit libcurl from
using that IP version.

Available values for this option are:

CURL_IPRESOLVE_WHATEVER
Default, can use addresses of all IP versions that your system
allows.

CURL_IPRESOLVE_V4
Uses only IPv4 addresses.

CURL_IPRESOLVE_V6
Uses only IPv6 addresses.

DEFAULT

CURL_IPRESOLVE_WHATEVER

PROTOCOLS

This functionality affects all supported protocols

EXAMPLE

int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
CURLcode res;
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);

res = curl_easy_perform(curl);

curl_easy_cleanup(curl);
}
}

AVAILABILITY

Added in curl 7.10.8

RETURN VALUE

curl_easy_setopt(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error
occurred, see libcurl-errors(3).