CURLOPT_CLOSESOCKETDATA(3) Library Functions Manual CURLOPT_CLOSESOCKETDATA(3)

CURLOPT_CLOSESOCKETDATA - pointer passed to the socket close callback

#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CLOSESOCKETDATA,
                          void *pointer);

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

NULL

This functionality affects all supported protocols

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);
}

Added in curl 7.21.7

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

CURLOPT_CLOSESOCKETFUNCTION(3), CURLOPT_OPENSOCKETFUNCTION(3)

2024-11-07 libcurl