---

c: Copyright (C) Daniel Stenberg, <daniel.se>, et al. SPDX-License-Identifier: curl Title: CURLOPT_CLOSESOCKETDATA Section: 3 Source: libcurl See-also:

• CURLOPT_CLOSESOCKETFUNCTION (3)
• CURLOPT_OPENSOCKETFUNCTION (3)

---

NAME

CURLOPT_CLOSESOCKETDATA - pointer passed to the socket close callback

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CLOSESOCKETDATA,
                          void *pointer);

DESCRIPTION

Pass a pointer that remains untouched by libcurl and passed as the first argument in the closesocket callback set with CURLOPT_CLOSESOCKETFUNCTION(3).

DEFAULT

The default value of this parameter is NULL.

PROTOCOLS

All except file:

EXAMPLE

struct priv {
  void *custom;
};

static int closesocket(void *clientp, curl_socket_t item)
{
  struct priv *my = clientp;
  printf("our ptr: %p\n", my->custom);

  printf("libcurl wants to close %d now\n", (int)item);
  return 0;
}

int main(void)
{
  struct priv myown;
  CURL *curl = curl_easy_init();

  /* call this function to close sockets */
  curl_easy_setopt(curl, CURLOPT_CLOSESOCKETFUNCTION, closesocket);
  curl_easy_setopt(curl, CURLOPT_CLOSESOCKETDATA, &myown);

  curl_easy_perform(curl);
  curl_easy_cleanup(curl);
}

AVAILABILITY

Added in 7.21.7

RETURN VALUE

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.