Datasheet

Although HTTP is the protocol of choice for the Web, most browsers support additional protocols such

as the File Transfer Protocol (FTP).

Much like other protocols, an HTTP conversation consists of a handful of commands from the client and

a stream of data from the server. Although discussing the whole HTTP protocol is beyond this book’s

scope, it is important to grasp the basics of how the protocol operates. By using a telnet client, you can

“talk” to a Web server and try the protocol manually as shown in the following code (text typed by the

user appears with a gray background):

telnet localhost 80

Trying 127.0.0.1...

Connected to localhost.

Escape character is ‘^]’.

GET /index.html HTTP/1.1

Accept: text/plain,text/html

Host: localhost

User-Agent: Telnet

HTTP/1.1 200 OK

Date: Sun, 17 Oct 2004 23:47:49 GMT

Server: Apache/1.3.26 (Unix) Debian GNU/Linux PHP/4.1.2

Last-Modified: Sat, 26 Oct 2002 09:12:14 GMT

ETag: “19b498-100e-3dba5c6e”

Accept-Ranges: bytes

Content-Length: 4110

Keep-Alive: timeout=15, max=100

Connection: Keep-Alive

Content-Type: text/html; charset=iso-8859-1

<!DOCTYPE HTML PUBLIC “-//W3C//DTD HTML 3.2//EN”>

<HTML>

<HEAD>

<META NAME=”GENERATOR” CONTENT=”Mozilla/4.05 [en] (X11; I; Linux 2.3.99-pre3

i686) [Netscape]”>

<META NAME=”Description” CONTENT=”The initial installation of Debian/GNU

Apache.”>

<TITLE>Welcome to Your New Home Page!</TITLE>

</HEAD>

<BODY TEXT=”#000000” BGCOLOR=”#FFFFFF” LINK=”#0000EF” VLINK=”#55188A”

ALINK=”#FF0000”>

<BR>

<H1>Welcome to Your New Home in Cyberspace!</H1>

<BR>

The Basics of HTML

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