Native Messaging!

chrome/common/extensions/docs/examples/extensions/native_messaging/echo.rb

+#!/usr/bin/ruby
+
+require 'iconv'
+
+# A simple native client (works with Ruby 1.8 and 1.9).
+# All this client does is echo the text it recieves back at the extension.
+
+MESSAGE_TYPE_SEND_MESSAGE_REQUEST = 0
+MESSAGE_TYPE_SEND_MESSAGE_RESPONSE = 1
+MESSAGE_TYPE_CONNECT = 2
+MESSAGE_TYPE_CONNECT_MESSAGE = 3
+
+messageNumber = 0
+
+while (!STDIN.eof?)
+  # Read the message type (first 4 bytes).
+  messageType = STDIN.read(4).unpack('L')[0]
+
+  # Read the message length (4 bytes).
+  textLength = STDIN.read(4).unpack('L')[0]
+
+  # Read the text (JSON object) of the message.
+  text = Iconv.conv('UTF-8//IGNORE', 'UTF-8',
+                    STDIN.read(textLength) + ' ')[0..-2]
+
+  messageNumber += 1
+
+  response = Iconv.conv(
+      'UTF-8//IGNORE', 'UTF-8',
+      "{\"id\": #{messageNumber}, \"echo\": #{text}}" + ' ')[0..-2]
+
+  # Choose the correct message type for the response.
+  responseType = messageType == MESSAGE_TYPE_SEND_MESSAGE_REQUEST ?
+                 MESSAGE_TYPE_SEND_MESSAGE_RESPONSE :
+                 MESSAGE_TYPE_CONNECT_MESSAGE
+
+  STDOUT.write([responseType, response.length].pack('LL'))
+  STDOUT.write(response)
+  STDOUT.flush()
+end