Unknown option: "-3" Unix manual page for CURLINFO_SCHEME. (host=minya system=Darwin)
CURLINFO_SCHEME(3)         curl_easy_getinfo options        CURLINFO_SCHEME(3)

NAME
       CURLINFO_SCHEME  -  get the URL scheme (sometimes called protocol) used
       in the connection

SYNOPSIS
       #include <curl/curl.h>

       CURLcode   curl_easy_getinfo(CURL   *handle,   CURLINFO_SCHEME,    char
       **scheme);

DESCRIPTION
       Pass  a pointer to a char pointer to receive the pointer to a zero-ter-
       minated string holding the URL scheme used for the most recent  connec-
       tion done with this CURL handle.

       The  scheme pointer will be NULL or pointing to private memory you MUST
       NOT free - it gets freed when you call curl_easy_cleanup(3) on the cor-
       responding CURL handle.

PROTOCOLS
       All

EXAMPLE
       CURL *curl = curl_easy_init();
       if(curl) {
         CURLcode res;
         curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");
         res = curl_easy_perform(curl);
         if(res == CURLE_OK) {
           char *scheme = NULL;
           curl_easy_getinfo(curl, CURLINFO_SCHEME, &scheme);
           if(scheme)
             printf("scheme: %s\n", scheme); /* scheme: HTTP */
         }
         curl_easy_cleanup(curl);
       }

AVAILABILITY
       Added in 7.52.0

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

SEE ALSO
       CURLINFO_RESPONSE_CODE(3), curl_easy_getinfo(3), curl_easy_setopt(3),

libcurl 7.54.0                  April 08, 2017              CURLINFO_SCHEME(3)