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

NAME
       CURLOPT_HTTPPOST - specify the multipart formpost content

SYNOPSIS
       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HTTPPOST,
                                 struct curl_httppost *formpost);

DESCRIPTION
       Tells  libcurl  you  want a multipart/formdata HTTP POST to be made and
       you instruct what data to pass on to the server in the  formpost  argu-
       ment.   Pass  a  pointer  to  a linked list of curl_httppost structs as
       parameter.  The easiest way to create such a list, is to use  curl_for-
       madd(3) as documented. The data in this list must remain intact as long
       as the curl transfer is alive and is using it.

       Using POST with HTTP 1.1 implies the use of  a  "Expect:  100-continue"
       header.  You can disable this header with CURLOPT_HTTPHEADER(3).

       When  setting  CURLOPT_HTTPPOST(3),  it  will  automatically  set  CUR-
       LOPT_NOBODY(3) to 0.

DEFAULT
       NULL

PROTOCOLS
       HTTP

EXAMPLE
       /* Fill in the file upload field. This makes libcurl load data from
          the given file name when curl_easy_perform() is called. */
       curl_formadd(&formpost,
                    &lastptr,
                    CURLFORM_COPYNAME, "sendfile",
                    CURLFORM_FILE, "postit2.c",
                    CURLFORM_END);

       /* Fill in the filename field */
       curl_formadd(&formpost,
                    &lastptr,
                    CURLFORM_COPYNAME, "filename",
                    CURLFORM_COPYCONTENTS, "postit2.c",
                    CURLFORM_END);

       /* Fill in the submit field too, even if this is rarely needed */
       curl_formadd(&formpost,
                    &lastptr,
                    CURLFORM_COPYNAME, "submit",
                    CURLFORM_COPYCONTENTS, "send",
                    CURLFORM_END);

AVAILABILITY
       As long as HTTP is enabled

RETURN VALUE
       Returns CURLE_OK if HTTP is enabled, and CURLE_UNKNOWN_OPTION if not.

SEE ALSO
       CURLOPT_POSTFIELDS(3),  CURLOPT_POST(3),  curl_formadd(3),   curl_form-
       free(3),

libcurl 7.54.0                   May 17, 2016              CURLOPT_HTTPPOST(3)