CURLOPT_CONNECTTIMEOUT_MS

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

Pass a long. It should contain the maximum time in milliseconds that you allow the connection phase to the server to take.

See CURLOPT_CONNECTTIMEOUT(3) for details.

300000

All

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
    /* complete connection within 10000 milliseconds */
    curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT_MS, 10000L);
    curl_easy_perform(curl);
  }
}

Always

Returns CURLE_OK

CURLOPT_CONNECTTIMEOUT(3), CURLOPT_LOW_SPEED_LIMIT(3), CURLOPT_TIMEOUT(3)