CURLSHOPT_SHARE(3) Library Functions Manual CURLSHOPT_SHARE(3)
NAME
CURLSHOPT_SHARE - add data to share
SYNOPSIS
#include <curl/curl.h>
CURLSHcode curl_share_setopt(CURLSH *share, CURLSHOPT_SHARE, long type);
DESCRIPTION
The type parameter specifies what specific data that should be shared
and kept in the share object that was created with curl_share_init(3).
The given type must be one of the values described below. You can set
CURLSHOPT_SHARE(3) multiple times with different data arguments to have
the share object share multiple types of data. Unset a type again by
setting CURLSHOPT_UNSHARE(3).
CURL_LOCK_DATA_COOKIE
Cookie data is shared across the easy handles using this shared
object. Note that this does not activate an easy handle's cookie
handling. You can do that separately by using
CURLOPT_COOKIEFILE(3) for example.
It is not supported to share cookies between multiple concurrent
threads.
CURL_LOCK_DATA_DNS
Cached DNS hosts are shared across the easy handles using this
shared object. Note that when you use the multi interface, all
easy handles added to the same multi handle share the DNS cache
by default without using this option.
CURL_LOCK_DATA_SSL_SESSION
SSL sessions are shared across the easy handles using this
shared object. This reduces the time spent in the SSL handshake
when reconnecting to the same server. This symbol was added in
7.10.3 but was not implemented until 7.23.0.
Note that when you use the multi interface, all easy handles
added to the same multi handle share the SSL session cache by
default without using this option.
CURL_LOCK_DATA_CONNECT
Put the connection cache in the share object and make all easy
handles using this share object share the connection cache.
It is not supported to share connections between multiple
concurrent threads.
Connections that are used for HTTP/2 or HTTP/3 multiplexing only
get additional transfers added to them if the existing
connection is held by the same multi or easy handle. libcurl
does not support doing multiplexed streams in different threads
using a shared connection.
Support for CURL_LOCK_DATA_CONNECT was added in 7.57.0, but the
symbol existed before this.
Note that when you use the multi interface, all easy handles
added to the same multi handle share the connection cache by
default without using this option.
CURL_LOCK_DATA_PSL
The Public Suffix List stored in the share object is made
available to all easy handle bound to the later. Since the
Public Suffix List is periodically refreshed, this avoids
updates in too many different contexts.
Added in 7.61.0.
Note that when you use the multi interface, all easy handles
added to the same multi handle share the PSL cache by default
without using this option.
CURL_LOCK_DATA_HSTS
The in-memory HSTS cache.
It is not supported to share the HSTS between multiple
concurrent threads.
Added in 7.88.0
PROTOCOLS
This functionality affects all supported protocols
EXAMPLE
int main(void)
{
CURLSHcode sh;
CURLSH *share = curl_share_init();
sh = curl_share_setopt(share, CURLSHOPT_SHARE, CURL_LOCK_DATA_COOKIE);
if(sh)
printf("Error: %s\n", curl_share_strerror(sh));
}
AVAILABILITY
Added in curl 7.10.3
RETURN VALUE
CURLSHE_OK (zero) means that the option was set properly, non-zero
means an error occurred. See libcurl-errors(3) for the full list with
descriptions.
SEE ALSO
CURLSHOPT_UNSHARE(3), curl_share_cleanup(3), curl_share_init(3),
curl_share_setopt(3)
libcurl 2025-03-09 CURLSHOPT_SHARE(3)
curl 8.12.1 - Generated Sun Mar 9 09:11:26 CDT 2025