\ Gforth 0.7.3 doesn't seem to have these defined.
     2 Constant AF_INET
   $40 Constant MSG_DONTWAIT
  2048 constant SOCK_NONBLOCK
     1 constant SOL_SOCKET
     2 Constant SO_REUSEADDR
    11 constant EAGAIN

\ Just some size definitions for the C structs / values.
sockaddr_in nip constant /sockaddr_in
4 constant /option_value

\ C FFI for functions which aren't defined in unix/socket.fs
c-library socketext
    c-function close() close n -- n ( fd -- result )
    c-function setsockopt setsockopt n n n a n -- n ( sockfd level optname optval optlen -- r )
end-c-library