CURLINFO_LOCAL_PORT - get the latest local port number

Added in curl 7.21.0

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.

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; }

CURLINFO_LOCAL_PORT - get the latest local port number

This functionality affects quic and tcp

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).

CURLINFO_LOCAL_IP(3), CURLINFO_PRIMARY_PORT(3), curl_easy_getinfo(3), curl_easy_setopt(3) libcurl 2025-06-16 CURLINFO_LOCAL_PORT(3)

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