CLISP-specific code

This document covers some parts of Land of Lisp that specifically require CLISP.

Sockets

CLISP has a neat little socket library… Here is how you can create a server, allow it to accept connections, and connect to it:

Creating a socket:

(defparameter my-socket (socket-server 4321))

The function socket-server creates a socket bound to the port passed in as its first parameter.

Then, when we want to accept something on that port, we call the blocking ”socket-accept”:

(defparameter my-stream (socket-accept my-socket))

Then, we can connect with the following code from a second instance of CLISP:

(defparameter my-stream (socket-connect 4321 "127.0.0.1"))

This will create a bi-directional stream on both CLISP instances… That means we can both read and write to either side.

Now, you can read, format, print, princ, or any number of commands that work with streams on either side.

To close a socket stream, you can run the following on the client:

(close my-stream)

And on the server, we can run:

(socket-server-close my-socket)