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

NAME
       CURLOPT_BUFFERSIZE - set preferred receive buffer size

SYNOPSIS
       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_BUFFERSIZE, long size);

DESCRIPTION
       Pass a long specifying your preferred size (in bytes) for  the  receive
       buffer  in  libcurl.   The  main  point of this would be that the write
       callback gets called more often and with smaller chunks. Secondly,  for
       some protocols, there's a benefit of having a larger buffer for perfor-
       mance.

       This is just treated as a request, not an order. You cannot be  guaran-
       teed to actually get the given size.

       This  buffer size is by default CURL_MAX_WRITE_SIZE (16kB). The maximum
       buffer size allowed to set is CURL_MAX_READ_SIZE (512kB).

DEFAULT
       CURL_MAX_WRITE_SIZE(16kB)

PROTOCOLS
       All

EXAMPLE
       TODO

AVAILABILITY
       Added in 7.10.  Growing the buffer was added in 7.53.0.

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

SEE ALSO
       CURLOPT_MAX_RECV_SPEED_LARGE(3), CURLOPT_WRITEFUNCTION(3),

libcurl 7.54.0                 December 20, 2016         CURLOPT_BUFFERSIZE(3)