curl_multi_assign - set data to associate with an internal socket
#include <curl/curl.h> CURLMcode curl_multi_assign(CURLM *multi_handle, curl_socket_t sockfd, void *sockptr);
curl_multi_assign(3) libcurl Manual curl_multi_assign(3)
NAME
curl_multi_assign - set data to associate with an internal socket
SYNOPSIS
#include <curl/curl.h>
CURLMcode curl_multi_assign(CURLM *multi_handle, curl_socket_t sockfd,
void *sockptr);
DESCRIPTION
This function creates an association in the multi handle between the
given socket and a private pointer of the application. This is designed
for curl_multi_socket_action(3) uses.
When set, the sockptr pointer will be passed to all future socket call-
backs for the specific sockfd socket.
If the given sockfd is not already in use by libcurl, this function
will return an error.
libcurl only keeps one single pointer associated with a socket, so
calling this function several times for the same socket will make the
last set pointer get used.
The idea here being that this association (socket to private pointer)
is something that just about every application that uses this API will
need and then libcurl can just as well do it since it already has an
internal hash table lookup for this.
It is acceptable to call this function from your multi callback func-
tions.
EXAMPLE
/* make our struct pointer associated with socket fd */
mc = curl_multi_assign(multi_handle, fd, ourstructp);
AVAILABILITY
Added in 7.15.5
RETURN VALUE
The standard CURLMcode for multi interface error codes.
TYPICAL USAGE
In a typical application you allocate a struct or at least use some
kind of semi-dynamic data for each socket that we must wait for action
on when using the curl_multi_socket_action(3) approach.
When our socket-callback gets called by libcurl and we get to know
about yet another socket to wait for, we can use curl_multi_assign(3)
to point out the particular data so that when we get updates about this
same socket again, we do not have to find the struct associated with
this socket by ourselves.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+------------------+
|Availability | web/curl |
+---------------+------------------+
|Stability | Uncommitted |
+---------------+------------------+
SEE ALSO
curl_multi_setopt(3), curl_multi_socket_action(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 March 05, 2022 curl_multi_assign(3)