curl/docs/libcurl/opts/CURLOPT_CLOSESOCKETFUNCTION.md
Daniel Stenberg b935fd4a07
docs: make each libcurl man specify protocol(s)
The mandatory header now has a mandatory list of protocols for which the
manpage is relevant.

Most man pages already has a "PROTOCOLS" section, but this introduces a
stricter way to specify the relevant protocols.

cd2nroff verifies that at least one protocol is mentioned (which can be
`*`).

This information is not used just yet, but A) the PROTOCOLS section can
now instead get generated and get a unified wording across all manpages
and B) this allows us to more reliably filter/search for protocol
specific manpages/options.

Closes #13166
2024-03-21 15:27:06 +01:00

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1.8 KiB
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---
c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
SPDX-License-Identifier: curl
Title: CURLOPT_CLOSESOCKETFUNCTION
Section: 3
Source: libcurl
See-also:
- CURLOPT_CLOSESOCKETDATA (3)
- CURLOPT_OPENSOCKETFUNCTION (3)
Protocol:
- *
---
# NAME
CURLOPT_CLOSESOCKETFUNCTION - callback to socket close replacement
# SYNOPSIS
~~~c
#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.
# DEFAULT
By default libcurl uses the standard socket close function.
# PROTOCOLS
All
# EXAMPLE
~~~c
struct priv {
void *custom;
};
static int closesocket(void *clientp, curl_socket_t item)
{
struct priv *my = clientp;
printf("our ptr: %p\n", my->custom);
printf("libcurl wants to close %d now\n", (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 7.21.7
# RETURN VALUE
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.