Re: (Fwd) [HARVEST:553] replacing doubleclick, etc. ads

From: Lionel Bouton <>
Date: Mon, 02 Feb 1998 20:21:12 +0100

At 18:33 02/02/98 , Lauri Laupmaa wrote:
>How could one squid user replace standard size ads from doubleclick,
>etc with some fixed size bitmap ???
>Has anyone written redirector to do it ?

Here is what I used with some success:

#!/usr/bin/awk -f
# rediradds.awk
# feel free to reuse, modify, etc..
if ( ($1 ~
er|banner|sponsor)(\.|\/|\?|=|_))/ ) &&
( ($1 !~ /\.htm/) && ($2 !~ "ip1.ip1.ip1.ip1/") && ($2 !~
"ip2.ip2.ip2.ip2/") ) )
        print "http://www/squid/removed.gif"|"cat";
        print ""|"cat";

I couldn't find why I need these 'cat'. When I remove them, squid act as if
the redirector didn't write anything. But when I test the script with or
without 'cat', it ouputs the same things! If someone could explain me...

The ($2 !~ ...) are there because two people don't want their ads filtered.

The 'removed.gif' is a 468x60x16 gif. I began with a transparent one, but I
think users want to know what the proxy removes. I replaced it with
something visible, but with quiet gray colors.

It seems rather fast (squid reports a 1ms avg service time on a P90, which
is the smallest it can report I believe) but I couldn't test it under heavy

Relevant to redirectors:

I have proposed one project for second year students in our school :
build a redirector which would allow interaction with the clients (for the
moment (de)activation of ads filter).

They must build
- a new redirector which takes a file with a regexp (the filter) and a file
with a list of IP-adresses (for which the redirector must activate the
filter) and reloads them when it receives a given signal.
- a server which will run on squid's host, receiving clients's requests,
writing to the IP-adresses file and sending the given signal to the
redirector when needed.
- a set of clients for various platforms, based on a UNIX command-line
version (in order to have a simple source base).

If it works I will post the results. (Should be done in 2 months).



   Lionel Bouton
   French student @ Supelec
   E-mail :
   Snail-mail : 4, place Edouard Branly
                 57070 Metz (France)
Received on Mon Feb 02 1998 - 11:27:09 MST

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