CURLOPT_CLOSESOCKETFUNCTION

Section: C Library Functions (3)
Updated: 202-0-19
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NAME

CURLOPT_CLOSESOCKETFUNCTION - callback to socket close replacement  

SYNOPSIS

#include <curl/curl.h>

int closesocket_callback(void *clientp, curl_socket_t item);

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CLOSESOCKETFUNCTION,
                          closesocket_callback);

 

DESCRIPTION

Pass a pointer to your callback function, which should match the prototype shown above.

This callback function gets called by libcurl instead of the close(3) or closesocket(3) call when sockets are closed (not for any other file descriptors). This is pretty much the reverse to the CURLOPT_OPENSOCKETFUNCTION(3) option. Return 0 to signal success and 1 if there was an error.

The clientp pointer is set with CURLOPT_CLOSESOCKETDATA(3). item is the socket libcurl wants to be closed.

Note that when using multi/share handles, your callback may get invoked even after the easy handle has been cleaned up. The callback and data is inherited by a new connection and that connection may live longer than the transfer itself in the multi/share handleaqs connection cache.  

DEFAULT

Use the standard socket close function.  

PROTOCOLS

This functionality affects all supported protocols  

EXAMPLE

struct priv {
  void *custom;
};

static int closesocket(void *clientp, curl_socket_t item)
{
  struct priv *my = clientp;
  printf("our ptr: %pn", m->custom);

  printf("libcurl wants to close %d nown", (int)item);
  return 0;
}

int main(void)
{
  struct priv myown;
  CURL *curl = curl_easy_init();

  /* call this function to close sockets */
  curl_easy_setopt(curl, CURLOPT_CLOSESOCKETFUNCTION, closesocket);
  curl_easy_setopt(curl, CURLOPT_CLOSESOCKETDATA, &myown);

  curl_easy_perform(curl);
  curl_easy_cleanup(curl);
}

 

AVAILABILITY

Added in curl 7.21.7  

RETURN VALUE

curl_easy_setopt(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors(3).  

SEE ALSO

CURLOPT_CLOSESOCKETDATA(3), CURLOPT_OPENSOCKETFUNCTION(3)

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Index

NAME

SYNOPSIS

DESCRIPTION

DEFAULT

PROTOCOLS

EXAMPLE

AVAILABILITY

RETURN VALUE

SEE ALSO