curl/docs/libcurl/opts/CURLINFO_ACTIVESOCKET.md
Daniel Stenberg eefcc1bda4
docs: introduce "curldown" for libcurl man page format
curldown is this new file format for libcurl man pages. It is markdown
inspired with differences:

- Each file has a set of leading headers with meta-data
- Supports a small subset of markdown
- Uses .md file extensions for editors/IDE/GitHub to treat them nicely
- Generates man pages very similar to the previous ones
- Generates man pages that still convert nicely to HTML on the website
- Detects and highlights mentions of curl symbols automatically (when
  their man page section is specified)

tools:

- cd2nroff: converts from curldown to nroff man page
- nroff2cd: convert an (old) nroff man page to curldown
- cdall: convert many nroff pages to curldown versions
- cd2cd: verifies and updates a curldown to latest curldown

This setup generates .3 versions of all the curldown versions at build time.

CI:

Since the documentation is now technically markdown in the eyes of many
things, the CI runs many more tests and checks on this documentation,
including proselint, link checkers and tests that make sure we capitalize the
first letter after a period...

Closes #12730
2024-01-23 00:29:02 +01:00

78 lines
1.9 KiB
Markdown

---
c: Copyright (C) Daniel Stenberg, <daniel.se>, et al.
SPDX-License-Identifier: curl
Title: CURLINFO_ACTIVESOCKET
Section: 3
Source: libcurl
See-also:
- CURLINFO_LASTSOCKET (3)
- CURLOPT_CONNECT_ONLY (3)
- curl_easy_getinfo (3)
- curl_easy_setopt (3)
---
# NAME
CURLINFO_ACTIVESOCKET - get the active socket
# SYNOPSIS
~~~c
#include <curl/curl.h>
CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_ACTIVESOCKET,
curl_socket_t *socket);
~~~
# DESCRIPTION
Pass a pointer to a curl_socket_t to receive the most recently active socket
used for the transfer connection by this curl session. If the socket is no
longer valid, *CURL_SOCKET_BAD* is returned. When you are finished working
with the socket, you must call curl_easy_cleanup(3) as usual on the easy
handle and let libcurl close the socket and cleanup other resources associated
with the handle. This option returns the active socket only after the transfer
is complete, and is typically used in combination with
CURLOPT_CONNECT_ONLY(3), which skips the transfer phase.
CURLINFO_ACTIVESOCKET(3) was added as a replacement for
CURLINFO_LASTSOCKET(3) since that one is not working on all platforms.
# PROTOCOLS
All
# EXAMPLE
~~~c
int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
CURLcode res;
curl_socket_t sockfd;
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
/* Do not do the transfer - only connect to host */
curl_easy_setopt(curl, CURLOPT_CONNECT_ONLY, 1L);
res = curl_easy_perform(curl);
/* Extract the socket from the curl handle */
res = curl_easy_getinfo(curl, CURLINFO_ACTIVESOCKET, &sockfd);
if(res != CURLE_OK) {
printf("Error: %s\n", curl_easy_strerror(res));
return 1;
}
}
}
~~~
# AVAILABILITY
Added in 7.45.0
# RETURN VALUE
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.