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)