HTTP Snifters

Never mind which programming language you prefer - php, asp or perl, on what server your site is running and which editor you use to design web pages - the result of your work will be delivered to a visitor's browser as HTTP-formatted message that consists of a header and a body. Of course you may be a good webmaster without knowing about HTTP as well as you may design web pages in your favorite WYSIWYG editor having no idea about HTML, but in both cases the knowledge of the "low level" technology would help to avoid numerous mistakes and to do your work faster and better.

First let's deal with the terms. Sniffers is a class of programs that allow you to observe the data that network computers send to each other. HTTP stands for Hypertext Transfer Protocol, i.e. a convention about web page transfer format. People surf the internet, participate in forums, listen to net radio, download files - all this involves HTTP protocol. By the way, in case you didn't know, the page you are reading now has been sent to your computer as a HTTP-response to a HTTP-request from your browser.

Consequently, HTTP Sniffers is a class of programs that show how a browser and a server talk to each other.

Now let's answer the main question: how a HTTP sniffer can help those going to become better webmasters?

Up to my opinion, every serious webmaster should have the full HTTP protocol specification - RFC 2616 - at hand (by the way, in HTTPLook you can find a html-help version of the specification with a convenient chapter structure, table of contents and index). But do not even try to read the specification as a book - from the beginning to the end - save your time and mental health. Use it simply as a reference manual when you encounter something that you cannot understand. The best way to study the HTTP is to watch it at work. To see the world wide web inner work you might use telnet (that's what I've begun with), write your own HTTP client program (only if you are not looking for easy ways), or run a HTTP sniffer. I recommend the latter.

Start with the following: run the sniffer and browse several pages of some website. See what the sniffer shows you. If you have chosen a good sniffer you'll see everything needed: control information, sources of html pages and scripts running on your computer - virtually the complete picture of data transfer. If you were not able to get the main idea at a first glance, read the corresponding chapters of RFC 2616. The things are getting clearer, aren't they? If they aren't, repeat the process.

After you have understood the basics of browser-to-server communication you are ready to study the points you are mostly interested in. If you want to know how survey data is transferred from a user to a server, visit any site with online form, fill it in and the sniffer will show you how the form is made up and how the form data is sent to be processed at a server. If you are going to create your own guest book or forum, see how they work on other sites and choose the best fitting idea. Soon you'll understand that studying the tricks of web mastering on examples is much faster and easier than in theory.

The sniffer will serve you after you have studied the basics of web programming as well - to find errors in your scripts, you know even experts sometimes do mistakes. With the help of HTTP sniffer you'll be able to reveal the errors faster.

Summary: If you look for a quickest way to study new web-programming methods saving your time and work, HTTP sniffer will help you.

Advertisement: everything that we talked about (and even a little more) you can experience yourself with  HTTP sniffer - HTTPLook, which you can download here (1 M).