CURLOPT_PORT(3)

CURLOPT_PORT3

Remote port number to connect to

Usage

#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PORT, long number);

Overview

We strongly discourage using this unreliable option since its scope is not obvious and hard to predict. Set the preferred port number in the URL instead.

This option sets number to be the remote port number to connect to, instead of the one specified in the URL or the default port for the used protocol.

Usually, you let the URL decide which port to use but this allows the application to override that.

While this option accepts a 'long', a port number is an unsigned 16-bit number and therefore using a port number lower than zero or over 65535 causes a CURLE_BAD_FUNCTION_ARGUMENT error.

Default

0 which makes it not used. This also makes port number zero impossible to set with this API.

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/foo.bin");
    curl_easy_setopt(curl, CURLOPT_PORT, 8080L);
    result = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}

Return value

curl_easy_setopt(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

7 releases since Debian 8 (Jessie); the text changed 6 times.

  1. 8
  2. 9
  3. 10
  4. 11
  5. 12
  6. 13
  7. Arch

Availability

Added in curl 7.1

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