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Posted on 1999-07-06
Medium Priority
Last Modified: 2013-12-25

What are their differents ?

Question by:andrewyu
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Accepted Solution

mouatts earned 40 total points
ID: 1834921
HTTP_REFERER contains the URL that was used to generate the page from which the current request was generated from. So for example when I add this answer to this question and hit the submit button the CGI that processes it will have an HTTP_REFERER set of

HTTP_REFERER is always present unless the connection was made by someone using telnet and the omitted to add the appropriate line.

HTTP_FORWARDED is added by some proxy servers and specifies the final target IP address (I believe that it may also be present when some servers do a redirection). This variable is not commonly supported and you will not generally see it.

As a consequence it is best to avoid using it if it is present.

(I believe this is a Netscape specific variable but would be interested if anyone could confirm this or identify any other servers or proxies that generate this as I'm trying to draw up a difinitive list of the HTTP environment variables used by various servers etc)

Author Comment

ID: 1834922
Thank you very much !


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