CURLOPT_OPENSOCKETDATA(3)

1CURLOPT_OPENSOCKETDATA(3)  curl_easy_setopt options  CURLOPT_OPENSOCKETDATA(3)
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NAME

6       CURLOPT_OPENSOCKETDATA - custom pointer passed to open socket callback
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SYNOPSIS

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

15       Pass a pointer that will be untouched by  libcurl  and  passed  as  the
16       first  argument in the opensocket callback set with CURLOPT_OPENSOCKET‐
17       FUNCTION(3).
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DEFAULT

20       The default value of this parameter is NULL.
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PROTOCOLS

23       All
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EXAMPLE

26       /* make libcurl use the already established socket 'sockfd' */
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28       static curl_socket_t opensocket(void *clientp,
29                                       curlsocktype purpose,
30                                       struct curl_sockaddr *address)
31       {
32         curl_socket_t sockfd;
33         sockfd = *(curl_socket_t *)clientp;
34         /* the actual externally set socket is passed in via the OPENSOCKETDATA
35            option */
36         return sockfd;
37       }
38
39       static int sockopt_callback(void *clientp, curl_socket_t curlfd,
40                                   curlsocktype purpose)
41       {
42         /* This return code was added in libcurl 7.21.5 */
43         return CURL_SOCKOPT_ALREADY_CONNECTED;
44       }
45
46       curl = curl_easy_init();
47       if(curl) {
48         /* libcurl will internally think that you connect to the host
49          * and port that you specify in the URL option. */
50         curl_easy_setopt(curl, CURLOPT_URL, "http://99.99.99.99:9999");
51         /* call this function to get a socket */
52         curl_easy_setopt(curl, CURLOPT_OPENSOCKETFUNCTION, opensocket);
53         curl_easy_setopt(curl, CURLOPT_OPENSOCKETDATA, &sockfd);
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55         /* call this function to set options for the socket */
56         curl_easy_setopt(curl, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
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58         res = curl_easy_perform(curl);
59
60         curl_easy_cleanup(curl);
61       }
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AVAILABILITY

64       Added in 7.17.1
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RETURN VALUE

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