CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS - balls
#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS, long timeout);
curl_easy_setopt options CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS(3)
NAME
CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS - head start for ipv6 for happy eye-
balls
SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS,
long timeout);
DESCRIPTION
Happy eyeballs is an algorithm that attempts to connect to both IPv4
and IPv6 addresses for dual-stack hosts, preferring IPv6 first for
timeout milliseconds. If the IPv6 address cannot be connected to within
that time then a connection attempt is made to the IPv4 address in par-
allel. The first connection to be established is the one that is used.
The range of suggested useful values for timeout is limited. Happy Eye-
balls 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.
DEFAULT
CURL_HET_DEFAULT (currently defined as 200L)
PROTOCOLS
All except FILE
EXAMPLE
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);
}
AVAILABILITY
Added in 7.59.0
RETURN VALUE
Returns CURLE_OK
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+------------------+
|Availability | web/curl |
+---------------+------------------+
|Stability | Uncommitted |
+---------------+------------------+
SEE ALSO
CURLOPT_CONNECTTIMEOUT_MS(3), CURLOPT_TIMEOUT(3), CUR-
LOPT_LOW_SPEED_LIMIT(3),
NOTES
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from https://curl.se/down-
load/curl-7.83.1.tar.bz2.
Further information about this software can be found on the open source
community website at http://curl.haxx.se/.
libcurl 7.83.1 November 26, 2021
CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS(3)