| 12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970 |
- .\" **************************************************************************
- .\" * _ _ ____ _
- .\" * Project ___| | | | _ \| |
- .\" * / __| | | | |_) | |
- .\" * | (__| |_| | _ <| |___
- .\" * \___|\___/|_| \_\_____|
- .\" *
- .\" * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
- .\" *
- .\" * This software is licensed as described in the file COPYING, which
- .\" * you should have received as part of this distribution. The terms
- .\" * are also available at https://curl.se/docs/copyright.html.
- .\" *
- .\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
- .\" * copies of the Software, and permit persons to whom the Software is
- .\" * furnished to do so, under the terms of the COPYING file.
- .\" *
- .\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
- .\" * KIND, either express or implied.
- .\" *
- .\" * SPDX-License-Identifier: curl
- .\" *
- .\" **************************************************************************
- .\"
- .TH CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS 3 "January 02, 2023" "libcurl 7.88.1" "curl_easy_setopt options"
- .SH NAME
- CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS \- head start for IPv6 for happy eyeballs
- .SH SYNOPSIS
- .nf
- #include <curl/curl.h>
- CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS,
- long timeout);
- .fi
- .SH DESCRIPTION
- Happy eyeballs is an algorithm that attempts to connect to both IPv4 and IPv6
- addresses for dual-stack hosts, preferring IPv6 first for \fItimeout\fP
- milliseconds. If the IPv6 address cannot be connected to within that time then
- a connection attempt is made to the IPv4 address in parallel. The first
- connection to be established is the one that is used.
- The range of suggested useful values for \fItimeout\fP is limited. Happy
- Eyeballs RFC 6555 says "It is RECOMMENDED that connection attempts be paced
- 150-250 ms apart to balance human factors against network load." libcurl
- currently defaults to 200 ms. Firefox and Chrome currently default to 300 ms.
- .SH DEFAULT
- CURL_HET_DEFAULT (currently defined as 200L)
- .SH PROTOCOLS
- All except FILE
- .SH EXAMPLE
- .nf
- CURL *curl = curl_easy_init();
- if(curl) {
- curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
- curl_easy_setopt(curl, CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS, 300L);
- curl_easy_perform(curl);
- /* always cleanup */
- curl_easy_cleanup(curl);
- }
- .fi
- .SH AVAILABILITY
- Added in 7.59.0
- .SH RETURN VALUE
- Returns CURLE_OK
- .SH SEE ALSO
- .BR CURLOPT_CONNECTTIMEOUT_MS "(3), "
- .BR CURLOPT_TIMEOUT "(3), " CURLOPT_LOW_SPEED_LIMIT "(3), "
|
