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CURLOPT_OPENSOCKETDATA(3) curl_easy_setopt options CURLOPT_OPENSOCKETDATA(3)

NAME

CURLOPT_OPENSOCKETDATA - custom pointer passed to open socket callback

SYNOPSIS

#include <curl/curl.h>

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

DESCRIPTION

Pass a pointer that will be untouched by libcurl and passed as the first argument in the opensocket callback set with CURLOPT_OPENSOCKETFUNCTION(3).

DEFAULT

The default value of this parameter is NULL.

PROTOCOLS

All

EXAMPLE

/* make libcurl use the already established socket 'sockfd' */
static curl_socket_t opensocket(void *clientp,

curlsocktype purpose,
struct curl_sockaddr *address) {
curl_socket_t sockfd;
sockfd = *(curl_socket_t *)clientp;
/* the actual externally set socket is passed in via the OPENSOCKETDATA
option */
return sockfd; } static int sockopt_callback(void *clientp, curl_socket_t curlfd,
curlsocktype purpose) {
/* This return code was added in libcurl 7.21.5 */
return CURL_SOCKOPT_ALREADY_CONNECTED; } curl = curl_easy_init(); if(curl) {
/* libcurl will internally think that you connect to the host
* and port that you specify in the URL option. */
curl_easy_setopt(curl, CURLOPT_URL, "http://99.99.99.99:9999");
/* call this function to get a socket */
curl_easy_setopt(curl, CURLOPT_OPENSOCKETFUNCTION, opensocket);
curl_easy_setopt(curl, CURLOPT_OPENSOCKETDATA, &sockfd);
/* call this function to set options for the socket */
curl_easy_setopt(curl, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
res = curl_easy_perform(curl);
curl_easy_cleanup(curl); }

AVAILABILITY

Added in 7.17.1

RETURN VALUE

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

SEE ALSO

CURLOPT_OPENSOCKETFUNCTION(3), CURLOPT_SOCKOPTFUNCTION(3),

November 4, 2020 libcurl 7.79.1