CURLOPT_SOCKOPTDATA(3) Library Functions Manual CURLOPT_SOCKOPTDATA(3)

CURLOPT_SOCKOPTDATA - pointer to pass to sockopt callback

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

Pass a pointer that is untouched by libcurl and passed as the first argument in the sockopt callback set with CURLOPT_SOCKOPTFUNCTION(3).

The default value of this parameter is NULL.

All

static int sockopt_callback(void *clientp, curl_socket_t curlfd,

curlsocktype purpose) {
int val = *(int *)clientp;
setsockopt((int)curlfd, SOL_SOCKET, SO_RCVBUF,
(const char *)&val, sizeof(val));
return CURL_SOCKOPT_OK; } int main(void) {
CURL *curl = curl_easy_init();
if(curl) {
CURLcode res;
int recvbuffersize = 256 * 1024;
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
/* call this function to set options for the socket */
curl_easy_setopt(curl, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
curl_easy_setopt(curl, CURLOPT_SOCKOPTDATA, &recvbuffersize);
res = curl_easy_perform(curl);
curl_easy_cleanup(curl);
} }

Added in 7.16.0

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

CURLOPT_OPENSOCKETFUNCTION(3), CURLOPT_SOCKOPTFUNCTION(3)

September 26, 2023 ibcurl 8.4.0