Well, uh, I'm just writing a module that's called HTTP::Proxy. ;-)

The goal is to be able to pass every request and response though a set of configurable Perl "filters".

Here's an example script that creates a anonymizing proxy, just like in merlyn's column (his script has been one of my inspirations, along with two others scritps by Abigail and Rafael Garcia-Suarez):

#!/usr/bin/perl -w
use HTTP::Proxy qw( :log );
use strict;

# a very simple anonymizing proxy
my $proxy = HTTP::Proxy->new;
$proxy->logmask( shift || NONE );    # log configuration

# the anonymising filter
$proxy->push_headers_filter(
    mime    => undef,    # apply this on any type of content
    request => sub {
        $_[0]->remove_header(qw( User-Agent From Referer Cookie ));
    },
    response => sub {
        $_[0]->remove_header(qw( Set-Cookie )),;
    },
);

$proxy->start;
[download]

(This code works with the development version.)

The proxy is not fully functional yet, though. One of my goal is to create a set of filters that would log the whole session, so that yet another script could (automatically) create a web robot from the session transcript.

If you are interested, there is a web site (older versions and CVS snapshot) and a mailing-list at http://http-proxy.mongueurs.net/. I am interested in help, and comments on the API (which is subject to change).