CURLINFO_LOCAL_PORT - Man Page

#include <curl/curl.h>

CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_LOCAL_PORT, long *portp);

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

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

This functionality affects quic and tcp

int main(void)
{
  CURL *curl;
  CURLcode res;

  curl = curl_easy_init();
  if(curl) {
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
    res = curl_easy_perform(curl);

    if(CURLE_OK == res) {
      long port;
      res = curl_easy_getinfo(curl, CURLINFO_LOCAL_PORT, &port);

      if(CURLE_OK == res) {
        printf("We used local port: %ld\n", port);
      }
    }
    curl_easy_cleanup(curl);
  }
  return 0;
}

Added in curl 7.21.0

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

CURLINFO_LOCAL_IP(3), CURLINFO_PRIMARY_PORT(3), curl_easy_getinfo(3), curl_easy_setopt(3)

curl_easy_getinfo(3), CURLINFO_LOCAL_IP(3), CURLINFO_PRIMARY_IP(3), CURLINFO_PRIMARY_PORT(3), CURLOPT_LOCALPORT(3).