examples/ex1-client.lisp

   1 (in-package :iolib.examples)
   2
   3 ;;;; This file was originally written by Peter Keller (psilord@cs.wisc.edu)
   4 ;;;; and this code is released under the same license as IOLib.
   5
   6 ;;;; The entry call to this example is: (run-ex1-client) It can take
   7 ;;;; two keyword arguements of :host STRING and :port INTEGER.
   8
   9 ;;;; This example implements a very simple IPV4 TCP blocking i/o
  10 ;;;; client which talks to a date server. After connecting to the date
  11 ;;;; server, a single line is sent from the server to the cilent and
  12 ;;;; then the client disconnects.
  13
  14 ;;;; We don't handle many errors and this code is written from a
  15 ;;;; C-style perspective that we will avoid where possible in future
  16 ;;;; examples.
  17
  18 ;; ex-0b
  19 (defun run-ex1-client (&key (host *host*) (port *port*))
  20   ;; ex-0e
  21
  22   ;; ex-1b
  23   ;; Create a internet TCP socket under IPV4
  24   (let ((socket
  25          (make-socket
  26           :connect :active
  27           :address-family :internet
  28           :type :stream
  29           :external-format '(:utf-8 :eol-style :crlf)
  30           :ipv6 nil)))
  31     ;; ex-1e
  32
  33     ;; ex-2b
  34     ;; do a blocking connect to the daytime server on the port.
  35     (connect socket (lookup-hostname host) :port port :wait t)
  36     (format t "Connected to server ~A:~A via my local connection at ~A:~A!~%"
  37             (remote-host socket) (remote-port socket)
  38             (local-host socket) (local-port socket))
  39     ;; ex-2e
  40
  41     ;; ex-3b
  42     ;; read the one line of information I need from the daytime
  43     ;; server.  I can use read-line here because this is a TCP socket.
  44     (let ((line (read-line socket)))
  45       (format t "~A" line))
  46     ;; ex-3e
  47
  48     ;; ex-4b
  49     ;; all done
  50     (close socket)
  51     t))
  52 ;; ex-4e