There are many examples of use of websockets out there, however most of them are cumbersome or too complex for newbies.

Here is an extremely simple example of websockets which consists of a server (implemented both in PERL and Python, up to you the choice) that pushes a message (i.e. randomly generated values) to the client upon a fixed time interval.

Two clients are available in this example:

• client-JustLog.html displays on screen the log with the messages received;
• client-Chart.html shows a bar chart (based on Google Charts) which updates in real time with the data received.

#Configuration If you are running this code in a local host (i.e. your local machine) no configuration is needed. Otherwise, you can change ports and host from the config sections in the code.

1. SERVER: choose either send.pl (PERL) or send.py (Python) and run ONE of them from the terminal: type either perl send.pl or python send.py
2. CLIENT: Open one of the two clients (but they also work at the same time in two separate tabs) using a modern browser (e.g. tested and working with Chrome v.42+). Notice that the client must be opened after the server is running (otherwise, you will have to push the "reconnect" button).
3. See the data pushed automatically from the server to the client via websockets (Optionally, you might want to use Firebug with client-Chart.html to see the console logs)

• PERL or Python
• A modern browser that supports websockets (e.g. Chrome v.42+)

Notice:

• The PERL implementation of the server requires Net::WebSocket::Server. In Mac OSX it can be installed using the command: sudo perl -MCPAN -e 'install Net::WebSocket::Server'
• The Python implementation of the server requires Tornado that can be installed using pip (pip install tornado) or manually:

tar xvzf tornado-4.1.tar.gz
cd tornado-4.1
python setup.py build
sudo python setup.py install