quickjs-tart

quickjs-based runtime for wallet-core logic
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CURLOPT_CLOSESOCKETFUNCTION.md (2186B)

      1 ---
      2 c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
      3 SPDX-License-Identifier: curl
      4 Title: CURLOPT_CLOSESOCKETFUNCTION
      5 Section: 3
      6 Source: libcurl
      7 See-also:
      8   - CURLOPT_CLOSESOCKETDATA (3)
      9   - CURLOPT_OPENSOCKETFUNCTION (3)
     10 Protocol:
     11   - All
     12 Added-in: 7.21.7
     13 ---
     14 
     15 # NAME
     16 
     17 CURLOPT_CLOSESOCKETFUNCTION - callback to socket close replacement
     18 
     19 # SYNOPSIS
     20 
     21 ~~~c
     22 #include <curl/curl.h>
     23 
     24 int closesocket_callback(void *clientp, curl_socket_t item);
     25 
     26 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CLOSESOCKETFUNCTION,
     27                           closesocket_callback);
     28 ~~~
     29 
     30 # DESCRIPTION
     31 
     32 Pass a pointer to your callback function, which should match the prototype
     33 shown above.
     34 
     35 This callback function gets called by libcurl instead of the *close(3)* or
     36 *closesocket(3)* call when sockets are closed (not for any other file
     37 descriptors). This is pretty much the reverse to the
     38 CURLOPT_OPENSOCKETFUNCTION(3) option. Return 0 to signal success and 1
     39 if there was an error.
     40 
     41 The *clientp* pointer is set with
     42 CURLOPT_CLOSESOCKETDATA(3). *item* is the socket libcurl wants to be
     43 closed.
     44 
     45 Note that when using multi/share handles, your callback may get invoked even
     46 after the easy handle has been cleaned up. The callback and data is
     47 inherited by a new connection and that connection may live longer
     48 than the transfer itself in the multi/share handle's connection cache.
     49 
     50 # DEFAULT
     51 
     52 Use the standard socket close function.
     53 
     54 # %PROTOCOLS%
     55 
     56 # EXAMPLE
     57 
     58 ~~~c
     59 struct priv {
     60   void *custom;
     61 };
     62 
     63 static int closesocket(void *clientp, curl_socket_t item)
     64 {
     65   struct priv *my = clientp;
     66   printf("our ptr: %p\n", my->custom);
     67 
     68   printf("libcurl wants to close %d now\n", (int)item);
     69   return 0;
     70 }
     71 
     72 int main(void)
     73 {
     74   struct priv myown;
     75   CURL *curl = curl_easy_init();
     76 
     77   /* call this function to close sockets */
     78   curl_easy_setopt(curl, CURLOPT_CLOSESOCKETFUNCTION, closesocket);
     79   curl_easy_setopt(curl, CURLOPT_CLOSESOCKETDATA, &myown);
     80 
     81   curl_easy_perform(curl);
     82   curl_easy_cleanup(curl);
     83 }
     84 ~~~
     85 
     86 # %AVAILABILITY%
     87 
     88 # RETURN VALUE
     89 
     90 curl_easy_setopt(3) returns a CURLcode indicating success or error.
     91 
     92 CURLE_OK (0) means everything was OK, non-zero means an error occurred, see
     93 libcurl-errors(3).