9. WebSockets

The Hypertext Transfer Protocol (HTTP) is just great. Together with FTP, SMTP, IMAP, and many others, it is part of the large family of text-based protocols executed in the TCP/IP Application Layer. In these protocols, client and server communicate via messages in text form. The following listing demonstrates how easy it is to “speak” HTTP with a web server:

user@host:~> telnet www.google.com 80Trying 209.85.135.103...Connected to www.l.google.com.Escape character is '^]'.GET /search?q=html5 HTTP/1.0

To run a Google search for the term html5, we first connect to www.google.com on the port reserved for HTTP, port 80. The request has three parts: In the first part GET determines the method for the request; in this case we want to ...

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