curl-curl/docs/libcurl/opts/CURLINFO_CONN_ID.md

c	SPDX-License-Identifier	Title	Section	Source	See-also	Protocol	Added-in
Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.	curl	CURLINFO_CONN_ID	3	libcurl	CURLINFO_XFER_ID (3) curl_easy_getinfo (3) curl_easy_setopt (3)	All	8.2.0

NAME

CURLINFO_CONN_ID - ID of the last connection

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_CONN_ID,
                           curl_off_t *conn_id);

DESCRIPTION

Pass a pointer to a curl_off_t to receive the connection identifier last used by the handle. Stores -1 if there was no connection used.

The connection id is unique among all connections using the same connection cache. This is implicitly the case for all connections in the same multi handle.

%PROTOCOLS%

EXAMPLE

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode result;

    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");

    /* Perform the request */
    result = curl_easy_perform(curl);

    if(result == CURLE_OK) {
      curl_off_t conn_id;
      result = curl_easy_getinfo(curl, CURLINFO_CONN_ID, &conn_id);
      if(result == CURLE_OK) {
        printf("Connection used: %" CURL_FORMAT_CURL_OFF_T "\n", conn_id);
      }
    }
  }
}

%AVAILABILITY%

RETURN VALUE

curl_easy_getinfo(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).