Tribblix: manual page: CURLOPT

CURLOPT_SOCKOPTDATA(3) Introduction to Library Functions

NAME

CURLOPT_SOCKOPTDATA - pointer to pass to sockopt callback

SYNOPSIS

#include <curl/curl.h>

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

DESCRIPTION

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

DEFAULT

NULL

PROTOCOLS

This functionality affects all supported protocols

EXAMPLE

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);
}
}

AVAILABILITY

Added in curl 7.16.0

RETURN VALUE

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