Hello world/Web server: Difference between revisions

Here's the example with a pre-built server:

<lang lisp>(ql:quickload :hunchentoot)

(defpackage :hello-web (:use :cl :hunchentoot))

(in-package :hello-web)

(define-easy-handler (hello :uri "/") () "Goodbye, World!")

(defparameter *server* (hunchentoot:start (make-instance 'hunchentoot:easy-acceptor :port 8080)))</lang>

----

Here's an example of doing everything manually

<lang lisp>(ql:quickload :usocket)

(defpackage :hello-web-manual (:use :cl :usocket))

(in-package :hello-web-manual)

(defun crlf (&optional (stream *standard-output*))

(write-char #\return stream)

(write-char #\linefeed stream)

(values))

(defun ln (string &optional (stream *standard-output*))

(write-string string stream)

(crlf stream))

(defun read-all (stream)

(loop for char = (read-char-no-hang stream nil :eof)

until (or (null char) (eq char :eof)) collect char into msg

finally (return (values msg char))))

(defun serve (port &optional (log-stream *standard-output*))

(let ((connections (list (socket-listen "127.0.0.1" port :reuse-address t))))

(unwind-protect

(loop (loop for ready in (wait-for-input connections :ready-only t)

do (if (typep ready 'stream-server-usocket)

(push (socket-accept ready) connections)

(let* ((stream (socket-stream ready)))

(read-all stream)

(format log-stream "Got message...~%")

(mapc (lambda (line) (ln line stream))

(list "HTTP/1.1 200 OK"

"Content-Type: text/plain; charset=UTF-8"

""

"Hello world!"))

(socket-close ready)

(setf connections (remove ready connections))))))

(loop for c in connections do (loop while (socket-close c))))))

(serve 8080)</lang>