Explaining URLs

I've been a little busy with work so we are looking at almost a month since my last post.

Here is an example URL:

http://128.23.64.233:8080/contest/reward.html?key=value&key2=value2

Here is the break down to the parts of the URL:

- http:// is the transmission protocol (humans talk french, engish, etc.; computers talk http, ftp, telnet, etc.)
- 128.23.64.233 is the IP address of the website. If you use www.google.ca, your computer will turn this into 64.233.167.104.
- On a website computer it typically listens on port 80 for http talking. The :8080 tells our web browser to send the message to port 8080 on the website computer. You can access Google using http://www.google.ca:80/ but the :80 is not necessary.
- The /contest is call the context root. The web site sees the /contest and knows that all the files for /context root are stored in a specific location on the hard drive. Typically there will be a root to the website, e.g. C:\www\http\. For this context root the file could be in C:\www\http\contest\.
- The reward.html is the file that gets processed. The website will process different files different ways. It knows how to send you an HTML file or a JSP file.
- Everything after the ? are parameters for the web page. If I have a form on a web page it it has the following fields: name, password. Then I can enter the text in the textbox or I can do: http://somesite/login.html?name=myname&password=secret

So that is a simple break down for an HTTP URL. There is more to it but this is a start. I'll post more later and maybe a tutorial on how to peek at websites without using a web browser. Good way to avoid website viruses.