.\" **************************************************************************
.\" *                                  _   _ ____  _
.\" *  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 CURLMOPT_SOCKETDATA 3 "September 26, 2023" "ibcurl 8.4.0" libcurl

.SH NAME
CURLMOPT_SOCKETDATA \- custom pointer passed to the socket callback
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_SOCKETDATA, void *pointer);
.SH DESCRIPTION
A data \fIpointer\fP to pass to the socket callback set with the
\fICURLMOPT_SOCKETFUNCTION(3)\fP option.

This pointer is not touched by libcurl but is only passed in as the socket
callbacks's \fBclientp\fP argument.
.SH DEFAULT
NULL
.SH PROTOCOLS
All
.SH EXAMPLE
.nf
static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
{
  GlobalInfo *g = (GlobalInfo*) cbp;
  SockInfo *fdp = (SockInfo*) sockp;

  if(what == CURL_POLL_REMOVE) {
    remsock(fdp);
  }
  else {
    if(!fdp) {
      addsock(s, e, what, g);
    }
    else {
      setsock(fdp, s, e, what, g);
    }
  }
  return 0;
}

main()
{
  GlobalInfo setup;
  /* ... use socket callback and custom pointer */
  curl_multi_setopt(multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
  curl_multi_setopt(multi, CURLMOPT_SOCKETDATA, &setup);
}
.fi
.SH AVAILABILITY
Added in 7.15.4
.SH RETURN VALUE
Returns CURLM_OK.
.SH "SEE ALSO"
.BR curl_multi_socket_action (3),
.BR CURLMOPT_SOCKETFUNCTION (3),
.BR CURLMOPT_TIMERFUNCTION (3)