curl/docs/libcurl/opts/CURLOPT_IPRESOLVE.md
Daniel Stenberg e3fe020089
docs/libcurl: generate PROTOCOLS from meta-data
Remove the PROTOCOLS section from the source files completely and
instead generate them based on the header data in the curldown files.

It also generates TLS backend information for options marked for TLS as
protocol.

Closes #13175
2024-03-23 18:13:03 +01:00

1.5 KiB

c SPDX-License-Identifier Title Section Source See-also Protocol
Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. curl CURLOPT_IPRESOLVE 3 libcurl
CURLOPT_HTTP_VERSION (3)
CURLOPT_RESOLVE (3)
CURLOPT_SSLVERSION (3)
All

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

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

Always

RETURN VALUE

Returns CURLE_OK