curl/docs/libcurl/opts/CURLINFO_XFER_ID.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

1.3 KiB

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

NAME

CURLINFO_XFER_ID - get the ID of a transfer

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_XFER_ID,
                           curl_off_t *xfer_id);

DESCRIPTION

Pass a pointer to a curl_off_t to receive the identifier of the current/last transfer done with the handle. Stores -1 if no transfer has been started yet for the handle.

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

PROTOCOLS

All

EXAMPLE

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");

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

    if(!res) {
      curl_off_t xfer_id;
      res = curl_easy_getinfo(curl, CURLINFO_XFER_ID, &xfer_id);
      if(!res) {
        printf("Transfer ID: %" CURL_FORMAT_CURL_OFF_T "\n", xfer_id);
      }
    }
  }
}

AVAILABILITY

Added in 8.2.0

RETURN VALUE

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