curl/docs/libcurl/opts/CURLINFO_LASTSOCKET.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

1.8 KiB

c SPDX-License-Identifier Title Section Source See-also
Copyright (C) Daniel Stenberg, <daniel.se>, et al. curl CURLINFO_LASTSOCKET 3 libcurl
CURLINFO_ACTIVESOCKET (3)
CURLOPT_CONNECT_ONLY (3)
curl_easy_getinfo (3)
curl_easy_setopt (3)

NAME

CURLINFO_LASTSOCKET - get the last socket used

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_LASTSOCKET, long *socket);

DESCRIPTION

Deprecated since 7.45.0. Use CURLINFO_ACTIVESOCKET(3) instead.

Pass a pointer to a long to receive the last socket used by this curl session. If the socket is no longer valid, -1 is returned. When you finish working with the socket, you must call curl_easy_cleanup(3) as usual and let libcurl close the socket and cleanup other resources associated with the handle. This is typically used in combination with CURLOPT_CONNECT_ONLY(3).

NOTE: this API is deprecated since it is not working on win64 where the SOCKET type is 64 bits large while its 'long' is 32 bits. Use the CURLINFO_ACTIVESOCKET(3) instead, if possible.

PROTOCOLS

All

EXAMPLE

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    long sockfd; /* does not work on win64! */
    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_LASTSOCKET, &sockfd);

    if(res != CURLE_OK) {
      printf("Error: %s\n", curl_easy_strerror(res));
      return 1;
    }
  }
}

AVAILABILITY

Added in 7.15.2

RETURN VALUE

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.