CURLINFO_PRIMARY_PORT(3)

CURLINFO_PRIMARY_PORT3

Last destination port number

Usage

#include <curl/curl.h>
CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_PRIMARY_PORT, long *portp);

Overview

Pass a pointer to a long to receive the destination port of the most recent connection done with this curl handle.

This is the destination port of the actual TCP or UDP connection libcurl used. If a proxy was used for the most recent transfer, this is the port number of the proxy, if no proxy was used it is the port number of the most recently accessed URL.

If the connection was done using QUIC, the port number is a UDP port number.

If no connection was established or if the protocol does not use ports, -1 is returned.

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");
    result = curl_easy_perform(curl);
    if(result == CURLE_OK) {
      long port;
      result = curl_easy_getinfo(curl, CURLINFO_PRIMARY_PORT, &port);
      if(result == CURLE_OK)
        printf("Connected to remote port: %ld\n", port);
    }
    curl_easy_cleanup(curl);
  }
}

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

6 releases since Debian 9 (Stretch); the text changed 5 times.

  1. 9
  2. 10
  3. 11
  4. 12
  5. 13
  6. Arch

Availability

Added in curl 7.21.0

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