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

NAME
       CURLOPT_TFTP_BLKSIZE - TFTP block size

SYNOPSIS
       #include <curl/curl.h>

       CURLcode   curl_easy_setopt(CURL  *handle,  CURLOPT_TFTP_BLKSIZE,  long
       blocksize);

DESCRIPTION
       Specify blocksize to use for TFTP data transmission. Valid range as per
       RFC2348 is 8-65464 bytes. The default of 512 bytes will be used if this
       option is not specified. The specified block size  will  only  be  used
       pending  support by the remote server. If the server does not return an
       option acknowledgement or returns an  option  acknowledgement  with  no
       blksize, the default of 512 bytes will be used.

DEFAULT
       512

PROTOCOLS
       TFTP

EXAMPLE
       TODO

AVAILABILITY
       Added in 7.19.4

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

SEE ALSO
       CURLOPT_MAXFILESIZE(3),

libcurl 7.54.0                 February 03, 2016       CURLOPT_TFTP_BLKSIZE(3)