Unknown option: "-3" Unix manual page for CURLOPT_FTP_ALTERNATIVE_TO_USER. (host=minya system=Darwin)
CURLOPT_FTP_ALTERNATIVE_TO_curl_easy_setopt CURLOPT_FTP_ALTERNATIVE_TO_USER(3)

NAME
       CURLOPT_FTP_ALTERNATIVE_TO_USER  -  command to use instead of USER with
       FTP

SYNOPSIS
       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_ALTERNATIVE_TO_USER,
                                 char *cmd);

DESCRIPTION
       Pass a char * as parameter, pointing to a string which will be used  to
       authenticate  if the usual FTP "USER user" and "PASS password" negotia-
       tion fails. This is currently only known to be required when connecting
       to  Tumbleweed's Secure Transport FTPS server using client certificates
       for authentication.

       The application does not have to keep the string around  after  setting
       this option.

DEFAULT
       NULL

PROTOCOLS
       FTP

EXAMPLE
       TODO

AVAILABILITY
       Added in 7.15.5

RETURN VALUE
       Returns  CURLE_OK  if  the option is supported, CURLE_UNKNOWN_OPTION if
       not, or CURLE_OUT_OF_MEMORY if there was insufficient heap space.

SEE ALSO
       CURLOPT_FTP_SKIP_PASV_IP(3), CURLOPT_FTP_RESPONSE_TIMEOUT(3),

libcurl 7.54.0                 December 21, CURLOPT_FTP_ALTERNATIVE_TO_USER(3)