NAME

       CURLOPT_CONNECT_ONLY - stop when connected to target server

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CONNECT_ONLY, long only);

DESCRIPTION

       Pass  a  long.  If  the  parameter  equals  1,  it  tells  the  library to perform all the required proxy
       authentication and connection setup, but no data transfer, and then return.

       The option can be used to simply test a connection to a server, but is more useful  when  used  with  the
       CURLINFO_ACTIVESOCKET(3) option to curl_easy_getinfo(3) as the library can set up the connection and then
       the application can obtain the most recently used socket for special data transfers.

       Since 7.86.0, this option can be set to '2' and if HTTP or  WebSocket  are  used,  libcurl  performs  the
       request and reads all response headers before handing over control to the application.

       Transfers  marked  connect only do not reuse any existing connections and connections marked connect only
       are not allowed to get reused.

       If the connect only transfer is done using the multi interface, the particular easy  handle  must  remain
       added  to  the multi handle for as long as the application wants to use it. Once it has been removed with
       curl_multi_remove_handle(3), curl_easy_send(3) and curl_easy_recv(3) do not function.

DEFAULT

       0

PROTOCOLS

       HTTP, SMTP, POP3 and IMAP. For WS and WSS starting in 7.86.0.

EXAMPLE

       int main(void)
       {
         CURL *curl = curl_easy_init();
         if(curl) {
           CURLcode ret;
           curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
           curl_easy_setopt(curl, CURLOPT_CONNECT_ONLY, 1L);
           ret = curl_easy_perform(curl);
           if(ret == CURLE_OK) {
             /* only connected! */
           }
         }
       }

AVAILABILITY

       Added in 7.15.2

RETURN VALUE

       Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

SEE ALSO

       curl_easy_recv(3), curl_easy_send(3), CURLOPT_HTTPPROXYTUNNEL(3), CURLOPT_VERBOSE(3)