quickjs-tart

quickjs-based runtime for wallet-core logic
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CURLOPT_OPENSOCKETDATA.md (2219B)

      1 ---
      2 c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
      3 SPDX-License-Identifier: curl
      4 Title: CURLOPT_OPENSOCKETDATA
      5 Section: 3
      6 Source: libcurl
      7 See-also:
      8   - CURLOPT_CLOSESOCKETFUNCTION (3)
      9   - CURLOPT_OPENSOCKETFUNCTION (3)
     10   - CURLOPT_SOCKOPTFUNCTION (3)
     11 Protocol:
     12   - All
     13 Added-in: 7.17.1
     14 ---
     15 
     16 # NAME
     17 
     18 CURLOPT_OPENSOCKETDATA - pointer passed to open socket callback
     19 
     20 # SYNOPSIS
     21 
     22 ~~~c
     23 #include <curl/curl.h>
     24 
     25 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_OPENSOCKETDATA, void *pointer);
     26 ~~~
     27 
     28 # DESCRIPTION
     29 
     30 Pass a *pointer* that is untouched by libcurl and passed as the first
     31 argument in the open socket callback set with
     32 CURLOPT_OPENSOCKETFUNCTION(3).
     33 
     34 # DEFAULT
     35 
     36 NULL
     37 
     38 # %PROTOCOLS%
     39 
     40 # EXAMPLE
     41 
     42 ~~~c
     43 /* make libcurl use the already established socket 'sockfd' */
     44 
     45 static curl_socket_t opensocket(void *clientp,
     46                                 curlsocktype purpose,
     47                                 struct curl_sockaddr *address)
     48 {
     49   curl_socket_t sockfd;
     50   sockfd = *(curl_socket_t *)clientp;
     51   /* the actual externally set socket is passed in via the OPENSOCKETDATA
     52      option */
     53   return sockfd;
     54 }
     55 
     56 static int sockopt_callback(void *clientp, curl_socket_t curlfd,
     57                             curlsocktype purpose)
     58 {
     59   /* This return code was added in libcurl 7.21.5 */
     60   return CURL_SOCKOPT_ALREADY_CONNECTED;
     61 }
     62 
     63 int main(void)
     64 {
     65   CURL *curl = curl_easy_init();
     66   if(curl) {
     67     CURLcode res;
     68     extern int sockfd; /* the already connected one */
     69 
     70     /* libcurl thinks that you connect to the host
     71      * and port that you specify in the URL option. */
     72     curl_easy_setopt(curl, CURLOPT_URL, "http://99.99.99.99:9999");
     73     /* call this function to get a socket */
     74     curl_easy_setopt(curl, CURLOPT_OPENSOCKETFUNCTION, opensocket);
     75     curl_easy_setopt(curl, CURLOPT_OPENSOCKETDATA, &sockfd);
     76 
     77     /* call this function to set options for the socket */
     78     curl_easy_setopt(curl, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
     79 
     80     res = curl_easy_perform(curl);
     81 
     82     curl_easy_cleanup(curl);
     83   }
     84 }
     85 ~~~
     86 
     87 # %AVAILABILITY%
     88 
     89 # RETURN VALUE
     90 
     91 curl_easy_setopt(3) returns a CURLcode indicating success or error.
     92 
     93 CURLE_OK (0) means everything was OK, non-zero means an error occurred, see
     94 libcurl-errors(3).