CURLOPT_SOCKOPTDATA(3)

1CURLOPT_SOCKOPTDATA(3)              libcurl             CURLOPT_SOCKOPTDATA(3)
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NAME

6       CURLOPT_SOCKOPTDATA - pointer to pass to sockopt callback
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SYNOPSIS

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

14       Pass  a  pointer  that  will  be untouched by libcurl and passed as the
15       first argument in the sockopt callback  set  with  CURLOPT_SOCKOPTFUNC‐
16       TION(3).
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DEFAULT

19       The default value of this parameter is NULL.
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PROTOCOLS

22       All
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EXAMPLE

25       static int sockopt_callback(void *clientp, curl_socket_t curlfd,
26                                   curlsocktype purpose)
27       {
28         int val = *(int *)clientp;
29         setsockopt(curldfd, SOL_SOCKET, SO_RCVBUF, (const char *)&val, sizeof(val));
30         return CURL_SOCKOPT_OK;
31       }
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33       curl = curl_easy_init();
34       if(curl) {
35         int recvbuffersize = 256 * 1024;
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37         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
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39         /* call this function to set options for the socket */
40         curl_easy_setopt(curl, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
41         curl_easy_setopt(curl, CURLOPT_SOCKOPTDATA, &recvbuffersize);
42
43         res = curl_easy_perform(curl);
44
45         curl_easy_cleanup(curl);
46       }
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AVAILABILITY

49       Added in 7.16.0
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RETURN VALUE

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