tcp-web-listener

tcp-web-listener

Small server that listens to TCP connections on a given port and forwards all the received data to a web client through sock.js.

How to use

• Make sure you have node.js installed.

• Install this package globally with:

npm install -g tcp-web-listener

• Start the server:

tcp-web-listener

Note that the default TCP port is 4449, and the default HTTP port is 7779, but they can be configured through command line options. It is possible to use --help to have the list of available options with their default values.

• Open http://localhost:7779 in your browser.

• Connect to the TCP port with telnet (for example):

telnet localhost 4449

• Type something in the telnet console and press ENTER. Everything that is sent by telnet through the TCP port is displayed in the browser (line by line).

Browser API

The goal of this small server is not only to allow displaying in a small web page what is sent to a TCP port but mainly to provide a simple API to do whatever is useful in a web page when receiving data over a TCP port.

In your web application, include the following script tag:

<script src="http://localhost:7779/listener.js"></script>

Then register a function that will be called each time the small server receives a new line on the TCP port:

var removeListener = registerLiveListener(function (text) {
  console.log(text);
});

// call removeListener() to remove the listener

Note that the name of the register function (registerLiveListener) can be configured with the --register-function option on the command line.

There can be only one registered listener at a time. When calling registerLiveListener, any previous listener is overridden by the new one.

registerLiveListener accepts as a second argument the scope with which the listener (given as the first argument) will be called.