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The URL (Uniform Resource Locator) address is a sort of universal address. When it indicates a web page, it consists of a sequence of words and symbols which start with http://.
There are other services on the Internet whose URLs begin with :
<p style="padding-left: 8px">- gopher:// (Internet tool that searches for sites),
- ftp:// (file transfer protocol),
- file:///C:/ (html files on your hard disk),
- telnet:// (runs programs on remote computers),
- News:// (Newsgroup),
- mailto : (e-mail).</p> Syntax, case (upper or lower) and spelling of URL addresses absolutely have to be observed. The tiniest error will bar access.
After http://, the continuation of the URL address depends on the server on which the information is found. "www" often follows : http://www.stormshield.com.
But this is not a generality. There are also : http://members.aol.com/Anasys or http://dicdoc.kb.inserm.fr:2010/basisMeSH/catn.html#N05.
Next, words follow separated by dots, slashes(/), dashes (-), swung dashes (~), or number signs (#). A slash enables moving from one folder (directory) to another in the access path to the information.
This slash may be used to perform a URL filter evasion. Take for example that the following URL is blocked by a filter : http://membres.lycos.fr/sportsUS. A malicious person (as in someone who insists on accessing this page) may easily bypass the filter by inserting a double slash, e.g. : http://membres.lycos.fr/////sportsUS/. The filter will test the address in question without finding the forbidden chain (http://membres.lycos.fr/sportsUS).
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