CURLINFO_LOCAL_PORT(3) Introduction to Library Functions

NAME

CURLINFO_LOCAL_PORT - latest local port number

SYNOPSIS

#include <curl/curl.h>

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

DESCRIPTION

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.

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

PROTOCOLS

This functionality affects quic and tcp

EXAMPLE

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

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

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

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

AVAILABILITY

Added in curl 7.21.0

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).

SEE ALSO

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

libcurl 2026-01-08 CURLINFO_LOCAL_PORT(3)