Man pages sections > man3 > CURLOPT_SOCKOPTDATA

CURLOPT_SOCKOPTDATA - custom pointer to pass to sockopt callback

CURLOPT_SOCKOPTDATA(3) curl_easy_setopt options CURLOPT_SOCKOPTDATA(3)

NAME

CURLOPT_SOCKOPTDATA - custom 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 will be untouched by libcurl and passed as the first argument in the sockopt callback set with CURLOPT_SOCKOPTFUNCTION(3).

DEFAULT

The default value of this parameter is NULL.

PROTOCOLS

All

EXAMPLE

static int sockopt_callback(void *clientp, curl_socket_t curlfd,
                            curlsocktype purpose)
{
  int val = *(int *)clientp;
  setsockopt(curldfd, SOL_SOCKET, SO_RCVBUF, (const char *)&val, sizeof(val));
  return CURL_SOCKOPT_OK;
}
curl = curl_easy_init(); if(curl) { int recvbuffersize = 256 * 1024;
curl_easy_setopt(curl, CURLOPT_URL, "http://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 7.16.0

RETURN VALUE

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

SEE ALSO

CURLOPT_SOCKOPTFUNCTION(3), CURLOPT_OPENSOCKETFUNCTION(3),
May 15, 2017 libcurl 7.55.1