CURLOPT_PORT(3) Library Functions Manual CURLOPT_PORT(3) NAME CURLOPT_PORT - remote port number to connect to SYNOPSIS #include 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 just 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 res; curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/foo.bin"); curl_easy_setopt(curl, CURLOPT_PORT, 8080L); res = 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 2025-02-13 CURLOPT_PORT(3)