CURLINFO_PRIMARY_PORT(3) Introduction to Library Functions

NAME

CURLINFO_PRIMARY_PORT - last destination port number

SYNOPSIS

#include <curl/curl.h>

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

DESCRIPTION

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

EXAMPLE

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)
printf("Connected to remote port: %ld\n", port);
}
curl_easy_cleanup(curl);
}
}

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_PORT(3), CURLINFO_PRIMARY_IP(3), curl_easy_getinfo(3),
curl_easy_setopt(3)

libcurl 2026-01-08 CURLINFO_PRIMARY_PORT(3)