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

NAME
       CURLOPT_SSH_KNOWNHOSTS - file name holding the SSH known hosts

SYNOPSIS
       #include <curl/curl.h>

       CURLcode  curl_easy_setopt(CURL  *handle,  CURLOPT_SSH_KNOWNHOSTS, char
       *fname);

DESCRIPTION
       Pass a pointer to a zero terminated string holding the file name of the
       known_host  file  to  use.  The known_hosts file should use the OpenSSH
       file format as supported by libssh2. If this file is specified, libcurl
       will  only  accept connections with hosts that are known and present in
       that file, with a matching public key.  Use  CURLOPT_SSH_KEYFUNCTION(3)
       to alter the default behavior on host and key (mis)matching.

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

DEFAULT
       NULL

PROTOCOLS
       SFTP and SCP

EXAMPLE
       TODO

AVAILABILITY
       Added in 7.19.6

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_SSH_AUTH_TYPES(3), CURLOPT_SSH_HOST_PUBLIC_KEY_MD5(3),

libcurl 7.54.0                 December 21, 2016     CURLOPT_SSH_KNOWNHOSTS(3)