1---
2c: Copyright (C) Daniel Stenberg, <daniel.se>, et al.
3SPDX-License-Identifier: curl
4Title: CURLMOPT_SOCKETDATA
5Section: 3
6Source: libcurl
7See-also:
8  - CURLMOPT_SOCKETFUNCTION (3)
9  - CURLMOPT_TIMERFUNCTION (3)
10  - curl_multi_socket_action (3)
11---
12
13# NAME
14
15CURLMOPT_SOCKETDATA - custom pointer passed to the socket callback
16
17# SYNOPSIS
18
19~~~c
20#include <curl/curl.h>
21
22CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_SOCKETDATA, void *pointer);
23~~~
24
25# DESCRIPTION
26
27A data *pointer* to pass to the socket callback set with the
28CURLMOPT_SOCKETFUNCTION(3) option.
29
30This pointer is not touched by libcurl but is only passed in as the socket
31callbacks's **clientp** argument.
32
33# DEFAULT
34
35NULL
36
37# PROTOCOLS
38
39All
40
41# EXAMPLE
42
43~~~c
44struct priv {
45  void *ours;
46};
47
48static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
49{
50  struct priv *p = sockp;
51  printf("my ptr: %p\n", p->ours);
52
53  if(what == CURL_POLL_REMOVE) {
54    /* remove the socket from our collection */
55  }
56  if(what & CURL_POLL_IN) {
57    /* wait for read on this socket */
58  }
59  if(what & CURL_POLL_OUT) {
60    /* wait for write on this socket */
61  }
62
63  return 0;
64}
65
66int main(void)
67{
68  struct priv setup;
69  CURLM *multi = curl_multi_init();
70  /* ... use socket callback and custom pointer */
71  curl_multi_setopt(multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
72  curl_multi_setopt(multi, CURLMOPT_SOCKETDATA, &setup);
73}
74~~~
75
76# AVAILABILITY
77
78Added in 7.15.4
79
80# RETURN VALUE
81
82Returns CURLM_OK.
83