CURLOPT_PORT(3) Library Functions Manual CURLOPT_PORT(3)
NAME
CURLOPT_PORT - remote port number to connect to
SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PORT, long number);
DESCRIPTION
We discourage using this 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
EXAMPLE
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);
}
}
AVAILABILITY
Added in curl 7.1
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).
SEE ALSO
CURLINFO_PRIMARY_PORT(3), CURLOPT_STDERR(3), CURLOPT_URL(3)
libcurl 2026-03-23 CURLOPT_PORT(3)
curl 8.19.0 - Generated Sun Mar 29 14:48:22 CDT 2026