marshal_to_fd ?buf fd v marshals data v to file descriptor fd
using marshalling buffer buf, and marshalling flags flags.
Raises input errors as in Bigstring.really_write.
buf cannot hold enough data for marshalling.
marshal_to_sock_no_sigpipe ?buf sock v same as marshal_to_fd, but
writes to sockets only and uses Bigstring.really_send_no_sigpipe
to avoid SIGPIPE on sockets.
unmarshal_from_sock ?buf sock unmarshals data from socket sock
using unmarshalling buffer buf. Raises input errors as in
Bigstring.really_recv.
buf cannot hold enough data for unmarshalling.