Re: TIP: redirect on filename extension

On Tue, 1 Jun 1999, Nottingham, Mark (Australia) wrote:

> HOWEVER, it is possible for users to bypass this redirection in some cases.
> Because Web servers will ignore the query (?), parameter (;) and fragment
> (#) portions of the URL, including them can bypass the redirector regex,
> while still downloading the content. For instance,
> http://www.foo.com/bar.mp3?
> will, in many cases, get around the above regex.
>
> If you'd like to be The Man and keep the people down, try a regex like this:
>
> \.mp3([;#\?].*)*$

You'll probably find that \.mp3\b ('\b' being any character in the
word-boundry class) would do as well, and is what I have been using
for several months. It has caught every URL I've thrown at it for
testing purposes, as well as every URL the users have thrown at it.
:-)

Using the word-boundry class is useful in lots of other places, too...
I block banner sites thusly:
\bdoubleclick\.net
\bhyperbanner\.net
\bimgis\.com
\badforce\.com
\bsmartclicks\.com
etc...

This will catch any URL you can think of to any of these sites,
including those redirecting URLs such as
http://www.somesite.com/banner.cgi?http://foo.doubleclick.net/bar

I haven't done any benchmarks, but it might even be faster than
defining an arbitrary character class to match the situation.

-- Chris Dillon - cdillon@wolves.k12.mo.us - cdillon@inter-linc.net
   FreeBSD: The fastest and most stable server OS on the planet.
   For Intel x86 and Alpha architectures (SPARC under development).
   ( http://www.freebsd.org )

   "One should admire Windows users. It takes a great deal of
    courage to trust Windows with your data."
Received on Mon May 31 1999 - 20:37:08 MDT