curlopt_connect_only(3) mojave man page | unix.com

CURLOPT_CONNECT_ONLY(3) 				     curl_easy_setopt options					   CURLOPT_CONNECT_ONLY(3)

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.

DEFAULT
       0

PROTOCOLS
       HTTP, SMTP, POP3 and IMAP

EXAMPLE
       TODO

AVAILABILITY
       Added in 7.15.2

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

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

libcurl 7.54.0							 December 18, 2016					   CURLOPT_CONNECT_ONLY(3)