1---
2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
3SPDX-License-Identifier: curl
4Title: CURLOPT_PREREQDATA
5Section: 3
6Source: libcurl
7See-also:
8  - CURLINFO_PRIMARY_IP (3)
9  - CURLINFO_PRIMARY_PORT (3)
10  - CURLOPT_PREREQFUNCTION (3)
11Protocol:
12  - All
13Added-in: 7.80.0
14---
15
16# NAME
17
18CURLOPT_PREREQDATA - pointer passed to the pre-request callback
19
20# SYNOPSIS
21
22~~~c
23#include <curl/curl.h>
24
25CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PREREQDATA, void *pointer);
26~~~
27
28# DESCRIPTION
29
30Pass a *pointer* that is untouched by libcurl and passed as the first
31argument in the pre-request callback set with CURLOPT_PREREQFUNCTION(3).
32
33# DEFAULT
34
35NULL
36
37# %PROTOCOLS%
38
39# EXAMPLE
40
41~~~c
42struct priv {
43  void *custom;
44};
45
46static int prereq_callback(void *clientp,
47                           char *conn_primary_ip,
48                           char *conn_local_ip,
49                           int conn_primary_port,
50                           int conn_local_port)
51{
52  printf("Connection made to %s:%d\n", conn_primary_ip, conn_primary_port);
53  return CURL_PREREQFUNC_OK;
54}
55
56int main(void)
57{
58  struct priv prereq_data;
59  CURL *curl = curl_easy_init();
60  if(curl) {
61    curl_easy_setopt(curl, CURLOPT_PREREQFUNCTION, prereq_callback);
62    curl_easy_setopt(curl, CURLOPT_PREREQDATA, &prereq_data);
63    curl_easy_perform(curl);
64  }
65}
66~~~
67
68# %AVAILABILITY%
69
70# RETURN VALUE
71
72Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
73