CURLINFO_XFER_ID(3)

CURLINFO_XFER_ID3

Id of the transfer

Usage

#include <curl/curl.h>
CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_XFER_ID,
                           curl_off_t *xfer_id);

Overview

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

This functionality affects all supported protocols

Examples

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

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).

Releases

2 releases since Debian 13 (Trixie); the text changed 1 time.

  1. 13
  2. Arch

Availability

Added in curl 8.2.0

From curl 8.23.0-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.