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Sortix volatile manual

This manual documents Sortix volatile, a development build that has not been officially released. You can instead view this document in the latest official manual.

CURLOPT_SOCKOPTDATA(3) Library Functions Manual CURLOPT_SOCKOPTDATA(3)

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.

SEE ALSO

CURLOPT_OPENSOCKETFUNCTION(3), CURLOPT_SOCKOPTFUNCTION(3)

2025-08-10 libcurl
Copyright 2011-2025 Jonas 'Sortie' Termansen and contributors.
Sortix's source code is free software under the ISC license.
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