Progress... on a chrome NativeMessaging receiving app

background.js

chrome.browserAction.onClicked.addListener(connect);

pgp-ext-app.lisp

;;;; pgp-ext-app.lisp

(in-package #:pgp-ext-app)

;;; "pgp-ext-app" goes here. Hacks and glory await!

(defun main (&rest args)
  "Application's entry point."
  (declare (ignore args))
  (read-stdin *standard-input*))

(defun read-stdin ()
  (with-open-file (stream "/home/florian/test.log" :direction :output :if-exists :append :if-does-not-exist :create)
    (with-open-stream (s *standard-input*)
      (let* ((length (parse-length (get-elements s 4)))
	     (buffer (chars-to-string (get-elements s length))))
	`(send-to-ext (jsown:to-json '(:obj ("text" . ,buffer))))))))

(defun get-elements (stream number &optional ret)
  "Gets x elements off of a stream"
  (if (= number 0)
      ret
      (get-elements stream (- number 1) (cons ret (read-char stream nil)))))

(defun chars-to-string (chars)
  (format nil "~{~c~}" chars))

;;; The missing part
(defun parse-length (bytes))

(defun string-to-chars (str)
  (loop for c across str collect c))

(defun send-to-ext (str)
  (let ((len (length str)))
    (format *standard-output*
	    "~c~c~c~c~{~c~}"
	    (code-char (logand len #xFF))
	    (code-char (logand (ash len 8) #xFF))
	    (code-char (logand (ash len 16) #xFF))
	    (code-char (logand (ash len 24) #xFF))
	    (string-to-chars str))))

pgp-ext.js

function connect() {
    var port = chrome.runtime.connectNative('com.margaine.pgp_ext_app');
    port.onMessage.addListener(function(msg) {
	console.log("Received", msg);
    });
    port.onDisconnect.addListener(function() {
	console.log("Disconnected");
    });
    console.log('1');
    port.postMessage("{ text: \"Hello, my_application\" }\n");
    console.log('2');
    port.postMessage({ text: "Hello again!" });
    console.log('3');
}