Differentiate DNS entries for same server?

[Adrian Ball - BID]

I need to be able to run a script which can distinguish between different
URLS that actually access the same document. eg I have a host 'fred.somewhere'
which is also aliased in the DNS as 'joe.somewhere' - I need to be able to
distinguish between a request for http://fred.somewhere/cgi-bin/blah
and http://joe.somewhere/cgi-bin/blah.
Does anyone know how to differentiate? (The environment variable
SERVER_NAME returns the same address no matter how it is referenced).
I am running NCSA v1.4 httpd

Thanks,
Adrian.
-------------------------------------------------------------------------------
Adrian Ball - Systems Manager Bio-Informatics Dept, IACR-Rothamsted
+44 1582 763133 - ext 2419 West Common, Harpenden, Herts, UK AL5 2JQ
mailto:adria...@bbsrc.ac.uk
http://www.res.bbsrc.ac.uk/computing/staff/adrian.html

[Tony Curtis]

[ BTW your email headers don't work:

To: Adrian Ball - BID <ball>
]

In article <4a1ua9$2...@is.bbsrc.ac.uk>

Adrian Ball - BID <ball> writes:

I need to be able to run a script which can distinguish
between different URLS that actually access the same
document. eg I have a host 'fred.somewhere' which is also
aliased in the DNS as 'joe.somewhere' - I need to be able to
distinguish between a request for
http://fred.somewhere/cgi-bin/blah and
http://joe.somewhere/cgi-bin/blah. Does anyone know how to

You can't. You need a different solution.

Read this to find out why:

<URL:http://www.thesphere.com/~dlp/TwoServers/>

tony