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<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook V3.1//EN" [
<!entity % dummy "IGNORE">
<!entity supported SYSTEM "supported.sgml">
<!entity newfeatures SYSTEM "newfeatures.sgml">
<!entity p-intro SYSTEM "privoxy.sgml">
<!entity seealso SYSTEM "seealso.sgml">
<!entity buildsource SYSTEM "buildsource.sgml">
<!entity contacting SYSTEM "contacting.sgml">
<!entity history SYSTEM "history.sgml">
<!entity copyright SYSTEM "copyright.sgml">
<!entity license SYSTEM "license.sgml">
<!entity p-authors SYSTEM "p-authors.sgml">
<!entity config SYSTEM "p-config.sgml">
<!entity p-version "3.0.11">
<!entity p-status "stable">
<!entity % p-authors-formal "INCLUDE"> <!-- include additional text, etc -->
<!entity % p-not-stable "IGNORE">
<!entity % p-stable "INCLUDE">
<!entity % p-text "IGNORE"> <!-- define we are not a text only doc -->
<!entity % p-doc "INCLUDE"> <!-- and we are a formal doc -->
<!entity % p-readme "IGNORE">
<!entity % user-man "IGNORE">
<!entity % config-file "IGNORE">
<!entity % p-supp-userman "IGNORE"> <!-- Omit some from supported.sgml -->
<!entity my-copy "&copy;"> <!-- kludge for docbook2man -->
<!entity % draft "IGNORE"> <!-- WIP stuff -->
<!entity % seealso-extra "INCLUDE"> <!-- extra stuff from seealso.sgml -->
<!entity my-app "<application>Privoxy</application>">
]>
<!--
File : $Source: /cvsroot/ijbswa/current/doc/source/user-manual.sgml,v $
Purpose : user manual
This file belongs into
ijbswa.sourceforge.net:/home/groups/i/ij/ijbswa/htdocs/
$Id: user-manual.sgml,v 2.103 2009/03/21 10:49:05 fabiankeil Exp $
Copyright (C) 2001-2009 Privoxy Developers http://www.privoxy.org/
See LICENSE.
========================================================================
NOTE: Please read developer-manual/documentation.html before touching
anything in this, or other Privoxy documentation.
========================================================================
-->
<article id="index">
<artheader>
<title>Privoxy &p-version; User Manual</title>
<pubdate>
<subscript>
<!-- Completely the wrong markup, but very little is allowed -->
<!-- in this part of an article. FIXME -->
<link linkend="copyright">Copyright</link> &my-copy; 2001-2009 by
<ulink url="http://www.privoxy.org/">Privoxy Developers</ulink>
</subscript>
</pubdate>
<pubdate>$Id: user-manual.sgml,v 2.103 2009/03/21 10:49:05 fabiankeil Exp $</pubdate>
<!--
Note: the following should generate a separate page, and a live link to it,
all nicely done. But it doesn't for some mysterious reason. Please leave
commented unless it can be fixed proper. For the time being, the
copyright/license declarations will be in their own sgml.
Hal.
-->
<abstract>
<![%dummy;[
<para>
<comment>
This is here to keep vim syntax file from breaking :/
If I knew enough to fix it, I would.
PLEASE DO NOT REMOVE! HB: hal@foobox.net
</comment>
</para>
]]>
<para>
The <citetitle>Privoxy User Manual</citetitle> gives users information on how to
install, configure and use <ulink
url="http://www.privoxy.org/">Privoxy</ulink>.
</para>
<!-- Include privoxy.sgml boilerplate: -->
&p-intro;
<!-- end privoxy.sgml -->
<para>
You can find the latest version of the <citetitle>Privoxy User Manual</citetitle> at <ulink
url="http://www.privoxy.org/user-manual/">http://www.privoxy.org/user-manual/</ulink>.
Please see the <link linkend="contact">Contact section</link> on how to
contact the developers.
</para>
<!-- <para> -->
<!-- Feel free to send a note to the developers at <email>ijbswa-developers@lists.sourceforge.net</email>. -->
<!-- </para> -->
</abstract>
</artheader>
<!-- ~~~~~ New section ~~~~~ -->
<sect1 label="1" id="introduction"><title>Introduction</title>
<para>
This documentation is included with the current &p-status; version of
<application>Privoxy</application>, v.&p-version;<![%p-not-stable;[,
and is mostly complete at this point. The most up to date reference for the
time being is still the comments in the source files and in the individual
configuration files. Development of a new version is currently nearing
completion, and includes significant changes and enhancements over
earlier versions. ]]>.
</para>
<!-- include only in non-stable versions -->
<![%p-not-stable;[
<para>
Since this is a &p-status; version, not all new features are well tested. This
documentation may be slightly out of sync as a result (especially with
CVS sources). And there <emphasis>may be</emphasis> bugs, though hopefully
not many!
</para>
]]>
<!-- ~~~~~ New section ~~~~~ -->
<sect2 id="features"><title>Features</title>
<para>
In addition to the core
features of ad blocking and
<ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookie</ulink> management,
<application>Privoxy</application> provides many supplemental
features<![%p-not-stable;[, some of them currently under development]]>,
that give the end-user more control, more privacy and more freedom:
</para>
<!-- Include newfeatures.sgml boilerplate here: -->
&newfeatures;
<!-- end boilerplate -->
</sect2>
</sect1>
<!-- ~ End section ~ -->
<!-- ~~~~~ New section ~~~~~ -->
<sect1 id="installation"><title>Installation</title>
<para>
<application>Privoxy</application> is available both in convenient pre-compiled
packages for a wide range of operating systems, and as raw source code.
For most users, we recommend using the packages, which can be downloaded from our
<ulink url="http://sourceforge.net/projects/ijbswa/">Privoxy Project
Page</ulink>.
</para>
<para>
Note:
On some platforms, the installer may remove previously installed versions, if
found. (See below for your platform). In any case <emphasis>be sure to backup
your old configuration if it is valuable to you.</emphasis> See the <link
linkend="upgradersnote">note to upgraders</link> section below.
</para>
<!-- ~~~~~ New section ~~~~~ -->
<sect2 id="installation-packages"><title>Binary Packages</title>
<para>
How to install the binary packages depends on your operating system:
</para>
<!-- XXX: The installation sections should be sorted -->
<!-- ~~~~~ New section ~~~~~ -->
<sect3 id="installation-pack-rpm"><title>Red Hat and Fedora RPMs</title>
<para>
RPMs can be installed with <literal>rpm -Uvh privoxy-&p-version;-1.rpm</literal>,
and will use <filename>/etc/privoxy</filename> for the location
of configuration files.
</para>
<para>
Note that on Red Hat, <application>Privoxy</application> will
<emphasis>not</emphasis> be automatically started on system boot. You will
need to enable that using <command>chkconfig</command>,
<command>ntsysv</command>, or similar methods.
</para>
<para>
If you have problems with failed dependencies, try rebuilding the SRC RPM:
<literal>rpm --rebuild privoxy-&p-version;-1.src.rpm</literal>. This
will use your locally installed libraries and RPM version.
</para>
<para>
Also note that if you have a <application>Junkbuster</application> RPM installed
on your system, you need to remove it first, because the packages conflict.
Otherwise, RPM will try to remove <application>Junkbuster</application>
automatically if found, before installing <application>Privoxy</application>.
</para>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 id="installation-deb"><title>Debian and Ubuntu</title>
<para>
DEBs can be installed with <literal>apt-get install privoxy</literal>,
and will use <filename>/etc/privoxy</filename> for the location of
configuration files.
</para>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 id="installation-pack-win"><title>Windows</title>
<para>
Just double-click the installer, which will guide you through
the installation process. You will find the configuration files
in the same directory as you installed <application>Privoxy</application> in.
</para>
<para>
Version 3.0.5 beta introduced full <application>Windows</application> service
functionality. On Windows only, the <application>Privoxy</application>
program has two new command line arguments to install and uninstall
<application>Privoxy</application> as a <emphasis>service</emphasis>.
</para>
<variablelist>
<varlistentry>
<term>Arguments:</term>
<listitem>
<para>
<replaceable class="parameter">--install</replaceable>[:<replaceable class="parameter">service_name</replaceable>]
</para>
<para>
<replaceable class="parameter">--uninstall</replaceable>[:<replaceable class="parameter">service_name</replaceable>]
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
After invoking <application>Privoxy</application> with
<command>--install</command>, you will need to bring up the
<application>Windows</application> service console to assign the user you
want <application>Privoxy</application> to run under, and whether or not you
want it to run whenever the system starts. You can start the
<application>Windows</application> services console with the following
command: <command>services.msc</command>. If you do not take the manual step
of modifying <application>Privoxy's</application> service settings, it will
not start. Note too that you will need to give Privoxy a user account that
actually exists, or it will not be permitted to
write to its log and configuration files.
</para>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 id="installation-pack-bintgz"><title>Solaris <!--, NetBSD, HP-UX--></title>
<para>
Create a new directory, <literal>cd</literal> to it, then unzip and
untar the archive. For the most part, you'll have to figure out where
things go. <!-- FIXME, more info needed? -->
</para>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 id="installation-os2"><title>OS/2</title>
<para>
First, make sure that no previous installations of
<application>Junkbuster</application> and / or
<application>Privoxy</application> are left on your
system. Check that no <application>Junkbuster</application>
or <application>Privoxy</application> objects are in
your startup folder.
</para>
<para>
Then, just double-click the WarpIN self-installing archive, which will
guide you through the installation process. A shadow of the
<application>Privoxy</application> executable will be placed in your
startup folder so it will start automatically whenever OS/2 starts.
</para>
<para>
The directory you choose to install <application>Privoxy</application>
into will contain all of the configuration files.
</para>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 id="installation-mac"><title>Mac OS X</title>
<para>
Unzip the downloaded file (you can either double-click on the zip file
icon from the Finder, or from the desktop if you downloaded it there).
Then, double-click on the package installer icon and follow the
installation process.
</para>
<para>
The privoxy service will automatically start after a successful
installation (in addition to every time your computer starts up). To
prevent the privoxy service from automatically starting when your
computer starts up, remove or rename the folder named
<literal>/Library/StartupItems/Privoxy</literal>.
</para>
<para>
To manually start or stop the privoxy service, use the Privoxy Utility
for Mac OS X. This application controls the privoxy service (e.g.
starting and stopping the service as well as uninstalling the software).
</para>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 id="installation-amiga"><title>AmigaOS</title>
<para>
Copy and then unpack the <filename>lha</filename> archive to a suitable location.
All necessary files will be installed into <application>Privoxy</application>
directory, including all configuration and log files. To uninstall, just
remove this directory.
</para>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 id="installation-tbz"><title>FreeBSD</title>
<para>
Privoxy is part of FreeBSD's Ports Collection, you can build and install
it with <literal>cd /usr/ports/www/privoxy; make install clean</literal>.
</para>
<para>
If you don't use the ports, you can fetch and install
the package with <literal>pkg_add -r privoxy</literal>.
</para>
<para>
The port skeleton and the package can also be downloaded from the
<ulink url="https://sourceforge.net/project/showfiles.php?group_id=11118">File Release
Page</ulink>, but there's no reason to use them unless you're interested in the
beta releases which are only available there.
</para>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 id="installattion-gentoo"><title>Gentoo</title>
<para>
Gentoo source packages (Ebuilds) for <application>Privoxy</application> are
contained in the Gentoo Portage Tree (they are not on the download page,
but there is a Gentoo section, where you can see when a new
<application>Privoxy</application> Version is added to the Portage Tree).
</para>
<para>
Before installing <application>Privoxy</application> under Gentoo just do
first <literal>emerge --sync</literal> to get the latest changes from the
Portage tree. With <literal>emerge privoxy</literal> you install the latest
version.
</para>
<para>
Configuration files are in <filename>/etc/privoxy</filename>, the
documentation is in <filename>/usr/share/doc/privoxy-&p-version;</filename>
and the Log directory is in <filename>/var/log/privoxy</filename>.
</para>
</sect3>
</sect2>
<!-- ~~~~~ New section ~~~~~ -->
<sect2 id="installation-source"><title>Building from Source</title>
<para>
The most convenient way to obtain the <application>Privoxy</application> sources
is to download the source tarball from our
<ulink url="http://sourceforge.net/project/showfiles.php?group_id=11118&amp;package_id=10571">project download
page</ulink>.
</para>
<para>
If you like to live on the bleeding edge and are not afraid of using
possibly unstable development versions, you can check out the up-to-the-minute
version directly from <ulink url="http://sourceforge.net/cvs/?group_id=11118">the
CVS repository</ulink>.
<!--
deprecated...out of business.
or simply download <ulink
url="http://cvs.sourceforge.net/cvstarballs/ijbswa-cvsroot.tar.bz2">the nightly CVS
tarball.</ulink>
-->
</para>
<!-- include buildsource.sgml boilerplate: -->
&buildsource;
<!-- end boilerplate -->
</sect2>
<!-- ~~~~~ New section ~~~~~ -->
<sect2 id="installation-keepupdated"><title>Keeping your Installation Up-to-Date</title>
<para>
As user feedback comes in and development continues, we will make updated versions
of both the main <link linkend="actions-file">actions file</link> (as a <ulink
url="http://sourceforge.net/project/showfiles.php?group_id=11118&amp;release_id=103670">separate
package</ulink>) and the software itself (including the actions file) available for
download.
</para>
<para>
If you wish to receive an email notification whenever we release updates of
<application>Privoxy</application> or the actions file, <ulink
url="http://lists.sourceforge.net/lists/listinfo/ijbswa-announce/">subscribe
to our announce mailing list</ulink>, ijbswa-announce@lists.sourceforge.net.
</para>
<para>
In order not to lose your personal changes and adjustments when updating
to the latest <literal>default.action</literal> file we <emphasis>strongly
recommend</emphasis> that you use <literal>user.action</literal> and
<literal>user.filter</literal> for your local
customizations of <application>Privoxy</application>. See the <link
linkend="actions-file">Chapter on actions files</link> for details.
</para>
</sect2>
</sect1>
<!-- ~ End section ~ -->
<!-- ~~~~~ New section ~~~~~ -->
<sect1 id="whatsnew">
<title>What's New in this Release</title>
<para>
<application>Privoxy 3.0.12</application> is mainly a bugfix release:
</para>
<para>
<itemizedlist>
<listitem>
<para>
The socket-timeout option now also works on platforms whose
select() implementation modifies the timeout structure.
Previously the timeout was triggered even if the connection
didn't stall. Reported by cyberpatrol.
</para>
</listitem>
<listitem>
<para>
The Connection: keep-alive code properly deals with files
larger than 2GB. Previously the connection was closed too
early.
</para>
</listitem>
<listitem>
<para>
The content length for files above 2GB is logged correctly.
</para>
</listitem>
<listitem>
<para>
The user-manual directive on the show-status page links to
the documentation location specified with the directive,
not to the Privoxy website.
</para>
</listitem>
<listitem>
<para>
When running in daemon mode, Privoxy doesn't log anything
to the console unless there are errors before the logfile
has been opened.
</para>
</listitem>
<listitem>
<para>
The show-status page prints warnings about invalid directives
on the same line as the directives themselves.
</para>
</listitem>
<listitem>
<para>
Fixed several justified (but harmless) compiler warnings,
mostly on 64 bit platforms.
</para>
</listitem>
<listitem>
<para>
The mingw32 version explicitly requests the default charset
to prevent display problems with some fonts available on more
recent Windows versions. Patch by Burberry.
</para>
</listitem>
<listitem>
<para>
The mingw32 version uses the Privoxy icon in the alt-tab
windows. Patch by Burberry.
</para>
</listitem>
<listitem>
<para>
The timestamp and the thread id is omitted in the "Fatal error"
message box on mingw32.
</para>
</listitem>
<listitem>
<para>
Fixed two related mingw32-only buffer overflows. Triggering
them required control over the configuration file, therefore
this isn't seen as a security issue.
</para>
</listitem>
<listitem>
<para>
In verbose mode, or if the new option --show-skipped-tests
is used, Privoxy-Regression-Test logs skipped tests and the
skip reason.
</para>
</listitem>
</itemizedlist>
</para>
<!-- ~~~~~ New section ~~~~~ -->
<sect2 id="upgradersnote">
<title>Note to Upgraders</title>
<para>
A quick list of things to be aware of before upgrading from earlier
versions of <application>Privoxy</application>:
</para>
<para>
<itemizedlist>
<listitem>
<para>
The recommended way to upgrade &my-app; is to backup your old
configuration files, install the new ones, verify that &my-app;
is working correctly and finally merge back your changes using
<application>diff</application> and maybe <application>patch</application>.
</para>
<para>
There are a number of new features in each &my-app; release and
most of them have to be explicitly enabled in the configuration
files. Old configuration files obviously don't do that and due
to syntax changes using old configuration files with a new
&my-app; isn't always possible anyway.
</para>
</listitem>
<listitem>
<para>
Note that some installers remove earlier versions completely,
including configuration files, therefore you should really save
any important configuration files!
</para>
</listitem>
<listitem>
<para>
On the other hand, other installers don't overwrite existing configuration
files, thinking you will want to do that yourself.
</para>
</listitem>
<listitem>
<para>
<filename>standard.action</filename> has been merged into
the <filename>default.action</filename> file.
</para>
</listitem>
<listitem>
<para>
In the default configuration only fatal errors are logged now.
You can change that in the <link linkend="DEBUG">debug section</link>
of the configuration file. You may also want to enable more verbose
logging until you verified that the new &my-app; version is working
as expected.
</para>
</listitem>
<listitem>
<para>
Three other config file settings are now off by default:
<link linkend="enable-remote-toggle">enable-remote-toggle</link>,
<link linkend="enable-remote-http-toggle">enable-remote-http-toggle</link>,
and <link linkend="enable-edit-actions">enable-edit-actions</link>.
If you use or want these, you will need to explicitly enable them, and
be aware of the security issues involved.
</para>
</listitem>
<!--
<listitem>
<para>
What constitutes a <quote>default</quote> configuration has changed,
and you may want to review which actions are <quote>on</quote> by
default. This is primarily a matter of emphasis, but some features
you may have been used to, may now be <quote>off</quote> by default.
There are also a number of new actions and filters you may want to
consider, most of which are not fully incorporated into the default
settings as yet (see above).
</para>
</listitem>
-->
<!--
<listitem>
<para>
The default actions setting is now <literal>Cautious</literal>. Previous
releases had a default setting of <literal>Medium</literal>. Experienced
users may want to adjust this, as it is fairly conservative by &my-app;
standards and past practices. See <ulink
url="http://config.privoxy.org/edit-actions-list?f=default">
http://config.privoxy.org/edit-actions-list?f=default</ulink>. New users
should try the default settings for a while before turning up the volume.
</para>
</listitem>
<listitem>
<para>
The default setting has filtering turned <emphasis>off</emphasis>, which
subsequently means that compression is <emphasis>on</emphasis>. Remember
that filtering does not work on compressed pages, so if you use, or want to
use, filtering, you will need to force compression off. Example:
</para>
<para>
<screen>
{ +<link linkend="filter">filter</link>{google} +<link linkend="prevent-compression">prevent-compression</link> }
.google.</screen>
</para>
<para>
Or if you use a number of filters, or filter many sites, you may just want
to turn off compression for all sites in
<filename>default.action</filename> (or
<filename>user.action</filename>).
</para>
</listitem>
<listitem>
<para>
Also, <link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> is
off by default now. If you've liked this feature in the past, you may want
to turn it back on in <filename>user.action</filename> now.
</para>
</listitem>
<listitem>
<para>
Some installers may not automatically start
<application>Privoxy</application> after installation.
</para>
</listitem>
-->
</itemizedlist>
</para>
</sect2>
</sect1>
<!-- ~~~~~ New section ~~~~~ -->
<sect1 id="quickstart"><title>Quickstart to Using Privoxy</title>
<para>
<itemizedlist>
<listitem>
<para>
Install <application>Privoxy</application>. See the <link
linkend="installation">Installation Section</link> below for platform specific
information.
</para>
</listitem>
<listitem>
<para>
Advanced users and those who want to offer <application>Privoxy</application>
service to more than just their local machine should check the <link
linkend="config">main config file</link>, especially the <link
linkend="access-control">security-relevant</link> options. These are
off by default.
</para>
</listitem>
<listitem>
<para>
Start <application>Privoxy</application>, if the installation program has
not done this already (may vary according to platform). See the section
<link linkend="startup">Starting <application>Privoxy</application></link>.
</para>
</listitem>
<listitem>
<para>
Set your browser to use <application>Privoxy</application> as HTTP and
HTTPS (SSL) <ulink url="http://en.wikipedia.org/wiki/Proxy_server">proxy</ulink>
by setting the proxy configuration for address of
<literal>127.0.0.1</literal> and port <literal>8118</literal>.
<emphasis>DO NOT</emphasis> activate proxying for <literal>FTP</literal> or
any protocols besides HTTP and HTTPS (SSL) unless you intend to prevent your
browser from using these protocols.
</para>
</listitem>
<listitem>
<para>
Flush your browser's disk and memory caches, to remove any cached ad images.
If using <application>Privoxy</application> to manage
<ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>,
you should remove any currently stored cookies too.
</para>
</listitem>
<listitem>
<para>
A default installation should provide a reasonable starting point for
most. There will undoubtedly be occasions where you will want to adjust the
configuration, but that can be dealt with as the need arises. Little
to no initial configuration is required in most cases, you may want
to enable the
<ulink url="config.html#ENABLE-EDIT-ACTIONS">web-based action editor</ulink> though.
Be sure to read the warnings first.
</para>
<para>
See the <link linkend="configuration">Configuration section</link> for more
configuration options, and how to customize your installation.
You might also want to look at the <link
linkend="quickstart-ad-blocking">next section</link> for a quick
introduction to how <application>Privoxy</application> blocks ads and
banners.
</para>
</listitem>
<listitem>
<para>
If you experience ads that slip through, innocent images that are
blocked, or otherwise feel the need to fine-tune
<application>Privoxy's</application> behavior, take a look at the <link
linkend="actions-file">actions files</link>. As a quick start, you might
find the <link linkend="act-examples">richly commented examples</link>
helpful. You can also view and edit the actions files through the <ulink
url="http://config.privoxy.org">web-based user interface</ulink>. The
Appendix <quote><link linkend="actionsanat">Troubleshooting: Anatomy of an
Action</link></quote> has hints on how to understand and debug actions that
<quote>misbehave</quote>.
</para>
</listitem>
<!--
Did anyone test these lately?
fk 2007-11-10
<listitem>
<para>
For easy access to &my-app;'s most important controls, drag the provided
<link linkend="bookmarklets">Bookmarklets</link> into your browser's
personal toolbar.
</para>
</listitem>
-->
<listitem>
<para>
Please see the section <link linkend="contact">Contacting the
Developers</link> on how to report bugs, problems with websites or to get
help.
</para>
</listitem>
<listitem>
<para>
Now enjoy surfing with enhanced control, comfort and privacy!
</para>
</listitem>
</itemizedlist>
</para>
<!-- ~~~~~ New section ~~~~~ -->
<sect2 id="quickstart-ad-blocking">
<title>Quickstart to Ad Blocking</title>
<!--
NOTE: This section is deliberately redundant for those that don't
want to read the whole thing (which is getting lengthy).
-->
<para>
Ad blocking is but one of <application>Privoxy's</application>
array of features. Many of these features are for the technically minded advanced
user. But, ad and banner blocking is surely common ground for everybody.
</para>
<para>
This section will provide a quick summary of ad blocking so
you can get up to speed quickly without having to read the more extensive
information provided below, though this is highly recommended.
</para>
<para>
First a bit of a warning ... blocking ads is much like blocking SPAM: the
more aggressive you are about it, the more likely you are to block
things that were not intended. And the more likely that some things
may not work as intended. So there is a trade off here. If you want
extreme ad free browsing, be prepared to deal with more
<quote>problem</quote> sites, and to spend more time adjusting the
configuration to solve these unintended consequences. In short, there is
not an easy way to eliminate <emphasis>all</emphasis> ads. Either take
the easy way and settle for <emphasis>most</emphasis> ads blocked with the
default configuration, or jump in and tweak it for your personal surfing
habits and preferences.
</para>
<para>
Secondly, a brief explanation of <application>Privoxy's </application>
<quote>actions</quote>. <quote>Actions</quote> in this context, are
the directives we use to tell <application>Privoxy</application> to perform
some task relating to HTTP transactions (i.e. web browsing). We tell
<application>Privoxy</application> to take some <quote>action</quote>. Each
action has a unique name and function. While there are many potential
<application>actions</application> in <application>Privoxy's</application>
arsenal, only a few are used for ad blocking. <link
linkend="actions">Actions</link>, and <link linkend="actions-file">action
configuration files</link>, are explained in depth below.
</para>
<para>
Actions are specified in <application>Privoxy's</application> configuration,
followed by one or more URLs to which the action should apply. URLs
can actually be URL type <link linkend="af-patterns">patterns</link> that use
wildcards so they can apply potentially to a range of similar URLs. The
actions, together with the URL patterns are called a section.
</para>
<para>
When you connect to a website, the full URL will either match one or more
of the sections as defined in <application>Privoxy's</application> configuration,
or not. If so, then <application>Privoxy</application> will perform the
respective actions. If not, then nothing special happens. Furthermore, web
pages may contain embedded, secondary URLs that your web browser will
use to load additional components of the page, as it parses the
original page's HTML content. An ad image for instance, is just an URL
embedded in the page somewhere. The image itself may be on the same server,
or a server somewhere else on the Internet. Complex web pages will have many
such embedded URLs. &my-app; can deal with each URL individually, so, for
instance, the main page text is not touched, but images from such-and-such
server are blocked.
</para>
<para>
The most important actions for basic ad blocking are: <literal><link
linkend="block">block</link></literal>, <literal><link
linkend="handle-as-image">handle-as-image</link></literal>,
<literal><link
linkend="handle-as-empty-document">handle-as-empty-document</link></literal>,and
<literal><link linkend="set-image-blocker">set-image-blocker</link></literal>:
</para>
<para>
<itemizedlist>
<listitem>
<para>
<literal><link linkend="block">block</link></literal> - this is perhaps
the single most used action, and is particularly important for ad blocking.
This action stops any contact between your browser and any URL patterns
that match this action's configuration. It can be used for blocking ads,
but also anything that is determined to be unwanted. By itself, it simply
stops any communication with the remote server and sends
<application>Privoxy</application>'s own built-in BLOCKED page instead to
let you now what has happened (with some exceptions, see below).
</para>
</listitem>
<listitem>
<para>
<literal><link linkend="handle-as-image">handle-as-image</link></literal> -
tells <application>Privoxy</application> to treat this URL as an image.
<application>Privoxy</application>'s default configuration already does this
for all common image types (e.g. GIF), but there are many situations where this
is not so easy to determine. So we'll force it in these cases. This is particularly
important for ad blocking, since only if we know that it's an image of
some kind, can we replace it with an image of our choosing, instead of the
<application>Privoxy</application> BLOCKED page (which would only result in
a <quote>broken image</quote> icon). There are some limitations to this
though. For instance, you can't just brute-force an image substitution for
an entire HTML page in most situations.
</para>
</listitem>
<listitem>
<para>
<literal><link linkend="handle-as-empty-document">handle-as-empty-document</link></literal> -
sends an empty document instead of <application>Privoxy's</application>
normal BLOCKED HTML page. This is useful for file types that are neither
HTML nor images, such as blocking JavaScript files.
</para>
</listitem>
<listitem>
<para>
<literal><link
linkend="set-image-blocker">set-image-blocker</link></literal> - tells
<application>Privoxy</application> what to display in place of an ad image that
has hit a block rule. For this to come into play, the URL must match a
<literal><link linkend="block">block</link></literal> action somewhere in the
configuration, <emphasis>and</emphasis>, it must also match an
<literal><link linkend="handle-as-image">handle-as-image</link></literal> action.
</para>
<para>
The configuration options on what to display instead of the ad are:
</para>
<simplelist>
<member>
&nbsp;&nbsp;&nbsp;<emphasis>pattern</emphasis> - a checkerboard pattern, so that an ad
replacement is obvious. This is the default.
</member>
</simplelist>
<simplelist>
<member>
&nbsp;&nbsp;&nbsp;<emphasis>blank</emphasis> - A very small empty GIF image is displayed.
This is the so-called <quote>invisible</quote> configuration option.
</member>
</simplelist>
<simplelist>
<member>
&nbsp;&nbsp;&nbsp;<emphasis>http://&lt;URL&gt;</emphasis> - A redirect to any image anywhere
of the user's choosing (advanced usage).
</member>
</simplelist>
</listitem>
</itemizedlist>
</para>
<para>
Advanced users will eventually want to explore &my-app;
<literal><link linkend="filter">filters</link></literal> as well. Filters
are very different from <literal><link
linkend="block">blocks</link></literal>.
A <quote>block</quote> blocks a site, page, or unwanted contented. Filters
are a way of filtering or modifying what is actually on the page. An example
filter usage: a text replacement of <quote>no-no</quote> for
<quote>nasty-word</quote>. That is a very simple example. This process can be
used for ad blocking, but it is more in the realm of advanced usage and has
some pitfalls to be wary off.
</para>
<para>
The quickest way to adjust any of these settings is with your browser through
the special <application>Privoxy</application> editor at <ulink
url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
(shortcut: <ulink url="http://p.p/">http://p.p/show-status</ulink>). This
is an internal page, and does not require Internet access.
</para>
<para>
Note that as of <application>Privoxy</application> 3.0.7 beta the
action editor is disabled by default. Check the
<ulink url="config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions
section in the configuration file</ulink> to learn why and in which
cases it's safe to enable again.
</para>
<para>
If you decided to enable the action editor, select the appropriate
<quote>actions</quote> file, and click
<quote><guibutton>Edit</guibutton></quote>. It is best to put personal or
local preferences in <filename>user.action</filename> since this is not
meant to be overwritten during upgrades, and will over-ride the settings in
other files. Here you can insert new <quote>actions</quote>, and URLs for ad
blocking or other purposes, and make other adjustments to the configuration.
<application>Privoxy</application> will detect these changes automatically.
</para>
<para>
A quick and simple step by step example:
</para>
<para>
<itemizedlist>
<listitem>
<para>
Right click on the ad image to be blocked, then select
<quote><guimenuitem>Copy Link Location</guimenuitem></quote> from the
pop-up menu.
</para>
</listitem>
<listitem>
<para>
Set your browser to
<ulink
url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
</para>
</listitem>
<listitem>
<para>
Find <filename>user.action</filename> in the top section, and click
on <quote><guibutton>Edit</guibutton></quote>:
</para>
<!-- image of editor and actions files selections -->
<para>
<figure pgwide="0" float="0"><title>Actions Files in Use</title>
<mediaobject>
<imageobject>
<imagedata fileref="files-in-use.jpg" format="jpg">
</imageobject>
<textobject>
<phrase>[ Screenshot of Actions Files in Use ]</phrase>
</textobject>
</mediaobject>
</figure>
</para>
</listitem>
<listitem>
<para>
You should have a section with only
<literal><link linkend="block">block</link></literal> listed under
<quote>Actions:</quote>.
If not, click a <quote><guibutton>Insert new section below</guibutton></quote>
button, and in the new section that just appeared, click the
<guibutton>Edit</guibutton> button right under the word <quote>Actions:</quote>.
This will bring up a list of all actions. Find
<literal><link linkend="block">block</link></literal> near the top, and click
in the <quote>Enabled</quote> column, then <quote><guibutton>Submit</guibutton></quote>
just below the list.
</para>
</listitem>
<listitem>
<para>
Now, in the <literal><link linkend="block">block</link></literal> actions section,
click the <quote><guibutton>Add</guibutton></quote> button, and paste the URL the
browser got from <quote><guimenuitem>Copy Link Location</guimenuitem></quote>.
Remove the <literal>http://</literal> at the beginning of the URL. Then, click
<quote><guibutton>Submit</guibutton></quote> (or
<quote><guibutton>OK</guibutton></quote> if in a pop-up window).
</para>
</listitem>
<listitem>
<para>
Now go back to the original page, and press <keycap>SHIFT-Reload</keycap>
(or flush all browser caches). The image should be gone now.
</para>
</listitem>
</itemizedlist>
</para>
<para>
This is a very crude and simple example. There might be good reasons to use a
wildcard pattern match to include potentially similar images from the same
site. For a more extensive explanation of <quote>patterns</quote>, and
the entire actions concept, see <link linkend="actions-file">the Actions
section</link>.
</para>
<para>
For advanced users who want to hand edit their config files, you might want
to now go to the <link linkend="act-examples">Actions Files Tutorial</link>.
The ideas explained therein also apply to the web-based editor.
</para>
<para>
There are also various
<link linkend="filter">filters</link> that can be used for ad blocking
(filters are a special subset of actions). These
fall into the <quote>advanced</quote> usage category, and are explained in
depth in later sections.
</para>
</sect2>
</sect1>
<!-- ~ End section ~ -->
<!-- ~~~~~ New section ~~~~~ -->
<sect1 id="startup">
<title>Starting Privoxy</title>
<para>
Before launching <application>Privoxy</application> for the first time, you
will want to configure your browser(s) to use
<application>Privoxy</application> as a HTTP and HTTPS (SSL)
<ulink url="http://en.wikipedia.org/wiki/Proxy_server">proxy</ulink>. The default is
127.0.0.1 (or localhost) for the proxy address, and port 8118 (earlier versions
used port 8000). This is the one configuration step <emphasis>that must be done
</emphasis>!
</para>
<para>
Please note that <application>Privoxy</application> can only proxy HTTP and
HTTPS traffic. It will not work with FTP or other protocols.
</para>
<!-- image of Mozilla Proxy configuration -->
<para>
<figure pgwide="0" float="0"><title>Proxy Configuration Showing
Mozilla/Netscape HTTP and HTTPS (SSL) Settings</title>
<mediaobject>
<imageobject>
<imagedata fileref="proxy_setup.jpg" format="jpg">
</imageobject>
<textobject>
<phrase>[ Screenshot of Mozilla Proxy Configuration ]</phrase>
</textobject>
</mediaobject>
</figure>
</para>
<para>
With <application>Firefox</application>, this is typically set under:
</para>
<literallayout>
<guibutton>Tools</guibutton> -> <guibutton>Options</guibutton> -> <guibutton>Advanced</guibutton> -> <guibutton>Network</guibutton> -><guibutton>Connection</guibutton> -> <guibutton>Settings</guibutton>
</literallayout>
<para>
Or optionally on some platforms:
</para>
<literallayout>
<guibutton>Edit</guibutton> -> <guibutton>Preferences</guibutton> -> <guibutton>General</guibutton> -> <guibutton>Connection Settings</guibutton> -> <guibutton>Manual Proxy Configuration</guibutton>
</literallayout>
<para>
With <application>Netscape</application> (and
<application>Mozilla</application>), this can be set under:
</para>
<literallayout>
<!-- Mix ascii and gui art, something for everybody -->
<!-- spacing on this is tricky -->
<guibutton>Edit</guibutton> -> <guibutton>Preferences</guibutton> -> <guibutton>Advanced</guibutton> -> <guibutton>Proxies</guibutton> -> <guibutton>HTTP Proxy</guibutton>
</literallayout>
<para>
For <application>Internet Explorer v.5-7</application>:
</para>
<literallayout>
<guibutton>Tools</guibutton> -> <guibutton>Internet Options</guibutton> -> <guibutton>Connections</guibutton> -> <guibutton>LAN Settings</guibutton>
</literallayout>
<para>
Then, check <quote>Use Proxy</quote> and fill in the appropriate info
(Address: 127.0.0.1, Port: 8118). Include HTTPS (SSL), if you want HTTPS
proxy support too (sometimes labeled <quote>Secure</quote>). Make sure any
checkboxes like <quote>Use the same proxy server for all protocols</quote> is
<emphasis>UNCHECKED</emphasis>. You want only HTTP and HTTPS (SSL)!
</para>
<!-- image of IE Proxy configuration -->
<para>
<figure pgwide="0" float="0"><title>Proxy Configuration Showing
Internet Explorer HTTP and HTTPS (Secure) Settings</title>
<mediaobject>
<imageobject>
<imagedata fileref="proxy2.jpg" format="jpg">
</imageobject>
<textobject>
<phrase>[ Screenshot of IE Proxy Configuration ]</phrase>
</textobject>
</mediaobject>
</figure>
</para>
<para>
After doing this, flush your browser's disk and memory caches to force a
re-reading of all pages and to get rid of any ads that may be cached. Remove
any <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>,
if you want <application>Privoxy</application> to manage that. You are now
ready to start enjoying the benefits of using
<application>Privoxy</application>!
</para>
<para>
<application>Privoxy</application> itself is typically started by specifying the
main configuration file to be used on the command line. If no configuration
file is specified on the command line, <application>Privoxy</application>
will look for a file named <filename>config</filename> in the current
directory. Except on Win32 where it will try <filename>config.txt</filename>.
</para>
<sect2 id="start-redhat">
<title>Red Hat and Fedora</title>
<para>
A default Red Hat installation may not start &my-app; upon boot. It will use
the file <filename>/etc/privoxy/config</filename> as its main configuration
file.
</para>
<para>
<screen>
# /etc/rc.d/init.d/privoxy start
</screen>
</para>
<para>
Or ...
</para>
<para>
<screen>
# service privoxy start
</screen>
</para>
</sect2>
<sect2 id="start-debian">
<title>Debian</title>
<para>
We use a script. Note that Debian typically starts &my-app; upon booting per
default. It will use the file
<filename>/etc/privoxy/config</filename> as its main configuration
file.
</para>
<para>
<screen>
# /etc/init.d/privoxy start
</screen>
</para>
</sect2>
<sect2 id="start-windows">
<title>Windows</title>
<para>
Click on the &my-app; Icon to start <application>Privoxy</application>. If no configuration file is
specified on the command line, <application>Privoxy</application> will look
for a file named <filename>config.txt</filename>. Note that Windows will
automatically start &my-app; when the system starts if you chose that option
when installing.
</para>
<para>
<application>Privoxy</application> can run with full Windows service functionality.
On Windows only, the &my-app; program has two new command line arguments
to install and uninstall &my-app; as a service. See the
<link linkend="installation-pack-win">Windows Installation
instructions</link> for details.
</para>
</sect2>
<sect2 id="start-unices">
<title>Solaris, NetBSD, FreeBSD, HP-UX and others</title>
<para>
Example Unix startup command:
</para>
<para>
<screen>
# /usr/sbin/privoxy /etc/privoxy/config
</screen>
</para>
</sect2>
<sect2 id="start-os2">
<title>OS/2</title>
<para>
During installation, <application>Privoxy</application> is configured to
start automatically when the system restarts. You can start it manually by
double-clicking on the <application>Privoxy</application> icon in the
<application>Privoxy</application> folder.
</para>
</sect2>
<sect2 id="start-macosx">
<title>Mac OS X</title>
<para>
After downloading the privoxy software, unzip the downloaded file by
double-clicking on the zip file icon. Then, double-click on the
installer package icon and follow the installation process.
</para>
<para>
The privoxy service will automatically start after a successful
installation. In addition, the privoxy service will automatically
start every time your computer starts up.
</para>
<para>
To prevent the privoxy service from automatically starting when your
computer starts up, remove or rename the folder named
/Library/StartupItems/Privoxy.
</para>
<para>
A simple application named Privoxy Utility has been created which
enables administrators to easily start and stop the privoxy service.
</para>
<para>
In addition, the Privoxy Utility presents a simple way for
administrators to edit the various privoxy config files. A method
to uninstall the software is also available.
</para>
<para>
An administrator username and password must be supplied in order for
the Privoxy Utility to perform any of the tasks.
</para>
</sect2>
<sect2 id="start-amigaos">
<title>AmigaOS</title>
<para>
Start <application>Privoxy</application> (with RUN &lt;&gt;NIL:) in your
<filename>startnet</filename> script (AmiTCP), in
<filename>s:user-startup</filename> (RoadShow), as startup program in your
startup script (Genesis), or as startup action (Miami and MiamiDx).
<application>Privoxy</application> will automatically quit when you quit your
TCP/IP stack (just ignore the harmless warning your TCP/IP stack may display that
<application>Privoxy</application> is still running).
</para>
</sect2>
<sect2 id="start-gentoo">
<title>Gentoo</title>
<para>
A script is again used. It will use the file <filename>/etc/privoxy/config
</filename> as its main configuration file.
</para>
<para>
<screen>
/etc/init.d/privoxy start
</screen>
</para>
<para>
Note that <application>Privoxy</application> is not automatically started at
boot time by default. You can change this with the <literal>rc-update</literal>
command.
</para>
<para>
<screen>
rc-update add privoxy default
</screen>
</para>
</sect2>
<!--
<para>
See the section <link linkend="cmdoptions">Command line options</link> for
further info.
</para>
must find a better place for this paragraph
<para>
The included default configuration files should give a reasonable starting
point. Most of the per site configuration is done in the
<ulink url="actions-file.html"><quote>actions</quote></ulink> files. These are
where various cookie actions are defined, ad and banner blocking, and other
aspects of <application>Privoxy</application> configuration. There are several
such files included, with varying levels of aggressiveness.
</para>
<para>
You will probably want to keep an eye out for sites for which you may prefer
persistent cookies, and add these to your actions configuration as needed. By
default, most of these will be accepted only during the current browser
session (aka <quote>session cookies</quote>), unless you add them to the
configuration. If you want the browser to handle this instead, you will need
to edit <filename>user.action</filename> (or through the web based interface)
and disable this feature. If you use more than one browser, it would make
more sense to let <application>Privoxy</application> handle this. In which
case, the browser(s) should be set to accept all cookies.
</para>
<para>
Another feature where you will probably want to define exceptions for trusted
sites is the popup-killing (through <ulink
url="actions-file.html#FILTER-POPUPS"><quote>+filter{popups}</quote></ulink>),
because your favorite shopping, banking, or leisure site may need
popups (explained below).
</para>
<para>
<application>Privoxy</application> does not support all of the optional HTTP/1.1
features yet. In the unlikely event that you experience inexplicable problems
with browsers that use HTTP/1.1 per default
(like <application>Mozilla</application> or recent versions of I.E.), you might
try to force HTTP/1.0 compatibility. For Mozilla, look under <literal>Edit -&gt;
Preferences -&gt; Debug -&gt; Networking</literal>.
Alternatively, set the <quote>+downgrade-http-version</quote> config option in
<filename>default.action</filename> which will downgrade your browser's HTTP
requests from HTTP/1.1 to HTTP/1.0 before processing them.
</para>
<para>
After running <application>Privoxy</application> for a while, you can
start to fine tune the configuration to suit your personal, or site,
preferences and requirements. There are many, many aspects that can
be customized. <quote>Actions</quote>
can be adjusted by pointing your browser to
<ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
(shortcut: <ulink url="http://p.p/">http://p.p/</ulink>),
and then follow the link to <quote>View &#38; Change the Current Configuration</quote>.
(This is an internal page and does not require Internet access.)
</para>
<para>
In fact, various aspects of <application>Privoxy</application>
configuration can be viewed from this page, including
current configuration parameters, source code version numbers,
the browser's request headers, and <quote>actions</quote> that apply
to a given URL. In addition to the actions file
editor mentioned above, <application>Privoxy</application> can also
be turned <quote>on</quote> and <quote>off</quote> (toggled) from this page.
</para>
<para>
If you encounter problems, try loading the page without
<application>Privoxy</application>. If that helps, enter the URL where
you have the problems into <ulink url="http://p.p/show-url-info">the browser
based rule tracing utility</ulink>. See which rules apply and why, and
then try turning them off for that site one after the other, until the problem
is gone. When you have found the culprit, you might want to turn the rest on
again.
</para>
<para>
If the above paragraph sounds gibberish to you, you might want to <link
linkend="actions-file">read more about the actions concept</link>
or even dive deep into the <link linkend="actionsanat">Appendix
on actions</link>.
</para>
<para>
If you can't get rid of the problem at all, think you've found a bug in
Privoxy, want to propose a new feature or smarter rules, please see the
section <link linkend="contact"><quote>Contacting the
Developers</quote></link> below.
</para>
-->
<!-- ~~~~~ New section ~~~~~ -->
<sect2 id="cmdoptions">
<title>Command Line Options</title>
<para>
<application>Privoxy</application> may be invoked with the following
command-line options:
</para>
<para>
<itemizedlist>
<listitem>
<para>
<emphasis>--version</emphasis>
</para>
<para>
Print version info and exit. Unix only.
</para>
</listitem>
<listitem>
<para>
<emphasis>--help</emphasis>
</para>
<para>
Print short usage info and exit. Unix only.
</para>
</listitem>
<listitem>
<para>
<emphasis>--no-daemon</emphasis>
</para>
<para>
Don't become a daemon, i.e. don't fork and become process group
leader, and don't detach from controlling tty. Unix only.
</para>
</listitem>
<listitem>
<para>
<emphasis>--pidfile FILE</emphasis>
</para>
<para>
On startup, write the process ID to <emphasis>FILE</emphasis>. Delete the
<emphasis>FILE</emphasis> on exit. Failure to create or delete the
<emphasis>FILE</emphasis> is non-fatal. If no <emphasis>FILE</emphasis>
option is given, no PID file will be used. Unix only.
</para>
</listitem>
<listitem>
<para>
<emphasis>--user USER[.GROUP]</emphasis>
</para>
<para>
After (optionally) writing the PID file, assume the user ID of
<emphasis>USER</emphasis>, and if included the GID of GROUP. Exit if the
privileges are not sufficient to do so. Unix only.
</para>
</listitem>
<listitem>
<para>
<emphasis>--chroot</emphasis>
</para>
<para>
Before changing to the user ID given in the <emphasis>--user</emphasis> option,
chroot to that user's home directory, i.e. make the kernel pretend to the &my-app;
process that the directory tree starts there. If set up carefully, this can limit
the impact of possible vulnerabilities in &my-app; to the files contained in that hierarchy.
Unix only.
</para>
</listitem>
<listitem>
<para>
<emphasis>--pre-chroot-nslookup hostname</emphasis>
</para>
<para>
Specifies a hostname to look up before doing a chroot. On some systems, initializing the
resolver library involves reading config files from /etc and/or loading additional shared
libraries from /lib. On these systems, doing a hostname lookup before the chroot reduces
the number of files that must be copied into the chroot tree.
</para>
<para>
For fastest startup speed, a good value is a hostname that is not in /etc/hosts but that
your local name server (listed in /etc/resolv.conf) can resolve without recursion
(that is, without having to ask any other name servers). The hostname need not exist,
but if it doesn't, an error message (which can be ignored) will be output.
</para>
</listitem>
<listitem>
<para>
<emphasis>configfile</emphasis>
</para>
<para>
If no <emphasis>configfile</emphasis> is included on the command line,
<application>Privoxy</application> will look for a file named
<quote>config</quote> in the current directory (except on Win32
where it will look for <quote>config.txt</quote> instead). Specify
full path to avoid confusion. If no config file is found,
<application>Privoxy</application> will fail to start.
</para>
</listitem>
</itemizedlist>
</para>
<para>
On <application>MS Windows</application> only there are two additional
command-line options to allow <application>Privoxy</application> to install and
run as a <emphasis>service</emphasis>. See the
<link linkend="installation-pack-win">Window Installation section</link>
for details.
</para>
</sect2>
</sect1>
<!-- ~ End section ~ -->
<!-- ~~~~~ New section ~~~~~ -->
<sect1 id="configuration"><title>Privoxy Configuration</title>
<para>
All <application>Privoxy</application> configuration is stored
in text files. These files can be edited with a text editor.
Many important aspects of <application>Privoxy</application> can
also be controlled easily with a web browser.
</para>
<!-- ~~~~~ New section ~~~~~ -->
<sect2>
<title>Controlling Privoxy with Your Web Browser</title>
<para>
<application>Privoxy</application>'s user interface can be reached through the special
URL <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
(shortcut: <ulink url="http://p.p/">http://p.p/</ulink>),
which is a built-in page and works without Internet access.
You will see the following section:
</para>
<!-- Needs to be put in a table and colorized -->
<screen>
<msgtext>
<bridgehead renderas="sect2">&nbsp;&nbsp;&nbsp;&nbsp;Privoxy Menu</bridgehead>
<simplelist>
<member>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&squf;&nbsp;&nbsp;<ulink url="http://config.privoxy.org/show-status">View & change the current configuration</ulink>
</member>
<member>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&squf;&nbsp;&nbsp;<ulink url="http://config.privoxy.org/show-version">View the source code version numbers</ulink>
</member>
<member>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&squf;&nbsp;&nbsp;<ulink url="http://config.privoxy.org/show-request">View the request headers.</ulink>
</member>
<member>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&squf;&nbsp;&nbsp;<ulink url="http://config.privoxy.org/show-url-info">Look up which actions apply to a URL and why</ulink>
</member>
<member>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&squf;&nbsp;&nbsp;<ulink url="http://config.privoxy.org/toggle">Toggle Privoxy on or off</ulink>
</member>
<member>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&squf;&nbsp;&nbsp;<ulink
url="http://www.privoxy.org/&p-version;/user-manual/">Documentation</ulink>
</member>
</simplelist>
</msgtext>
</screen>
<para>
This should be self-explanatory. Note the first item leads to an editor for the
<link linkend="actions-file">actions files</link>, which is where the ad, banner,
cookie, and URL blocking magic is configured as well as other advanced features of
<application>Privoxy</application>. This is an easy way to adjust various
aspects of <application>Privoxy</application> configuration. The actions
file, and other configuration files, are explained in detail below.
</para>
<para>
<quote>Toggle Privoxy On or Off</quote> is handy for sites that might
have problems with your current actions and filters. You can in fact use
it as a test to see whether it is <application>Privoxy</application>
causing the problem or not. <application>Privoxy</application> continues
to run as a proxy in this case, but all manipulation is disabled, i.e.
<application>Privoxy</application> acts like a normal forwarding proxy. There
is even a toggle <link linkend="bookmarklets">Bookmarklet</link> offered, so
that you can toggle <application>Privoxy</application> with one click from
your browser.
</para>
<para>
Note that several of the features described above are disabled by default
in <application>Privoxy</application> 3.0.7 beta and later.
Check the
<ulink url="config.html">configuration file</ulink> to learn why
and in which cases it's safe to enable them again.
</para>
</sect2>
<!-- ~ End section ~ -->
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<sect2 id="confoverview">
<title>Configuration Files Overview</title>
<para>
For Unix, *BSD and Linux, all configuration files are located in
<filename>/etc/privoxy/</filename> by default. For MS Windows, OS/2, and
AmigaOS these are all in the same directory as the
<application>Privoxy</application> executable. <![%p-not-stable;[ The name
and number of configuration files has changed from previous versions, and is
subject to change as development progresses.]]>
</para>
<para>
The installed defaults provide a reasonable starting point, though
some settings may be aggressive by some standards. For the time being, the
principle configuration files are:
</para>
<para>
<itemizedlist>
<listitem>
<para>
The <link linkend="config">main configuration file</link> is named <filename>config</filename>
on Linux, Unix, BSD, OS/2, and AmigaOS and <filename>config.txt</filename>
on Windows. This is a required file.
</para>
</listitem>
<listitem>
<para>
<filename>match-all.action</filename> is used to define which <quote>actions</quote>
relating to banner-blocking, images, pop-ups, content modification, cookie handling
etc should be applied by default. It should be the first actions file loaded.
</para>
<para>
<filename>default.action</filename> defines many exceptions (both positive and negative)
from the default set of actions that's configured in <filename>match-all.action</filename>.
It should be the second actions file loaded and shouldn't be edited by the user.
</para>
<para>
Multiple actions files may be defined in <filename>config</filename>. These
are processed in the order they are defined. Local customizations and locally
preferred exceptions to the default policies as defined in
<filename>match-all.action</filename> (which you will most probably want
to define sooner or later) are best applied in <filename>user.action</filename>,
where you can preserve them across upgrades. The file isn't installed by all
installers, but you can easily create it yourself with a text editor.
</para>
<para>
There is also a web based editor that can be accessed from
<ulink
url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
(Shortcut: <ulink
url="http://p.p/show-status">http://p.p/show-status</ulink>) for the
various actions files.
</para>
</listitem>
<listitem>
<para>
<quote>Filter files</quote> (the <link linkend="filter-file">filter
file</link>) can be used to re-write the raw page content, including
viewable text as well as embedded HTML and JavaScript, and whatever else
lurks on any given web page. The filtering jobs are only pre-defined here;
whether to apply them or not is up to the actions files.
<filename>default.filter</filename> includes various filters made
available for use by the developers. Some are much more intrusive than
others, and all should be used with caution. You may define additional
filter files in <filename>config</filename> as you can with
actions files. We suggest <filename>user.filter</filename> for any
locally defined filters or customizations.
</para>
</listitem>
</itemizedlist>
</para>
<para>
The syntax of the configuration and filter files may change between different
Privoxy versions, unfortunately some enhancements cost backwards compatibility.
<!-- Add link to documentation-->
</para>
<para>
All files use the <quote><literal>#</literal></quote> character to denote a
comment (the rest of the line will be ignored) and understand line continuation
through placing a backslash ("<literal>\</literal>") as the very last character
in a line. If the <literal>#</literal> is preceded by a backslash, it looses
its special function. Placing a <literal>#</literal> in front of an otherwise
valid configuration line to prevent it from being interpreted is called "commenting
out" that line. Blank lines are ignored.
</para>
<para>
The actions files and filter files
can use Perl style <link linkend="regex">regular expressions</link> for
maximum flexibility.
</para>
<para>
After making any changes, there is no need to restart
<application>Privoxy</application> in order for the changes to take
effect. <application>Privoxy</application> detects such changes
automatically. Note, however, that it may take one or two additional
requests for the change to take effect. When changing the listening address
of <application>Privoxy</application>, these <quote>wake up</quote> requests
must obviously be sent to the <emphasis>old</emphasis> listening address.
</para>
<![%p-not-stable;[
<para>
While under development, the configuration content is subject to change.
The below documentation may not be accurate by the time you read this.
Also, what constitutes a <quote>default</quote> setting, may change, so
please check all your configuration files on important issues.
</para>
]]>
</sect2>
</sect1>
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&config;
<!-- end include -->
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<sect1 id="actions-file"><title>Actions Files</title>
<!--
XXX: similar descriptions are in the Configuration Files sections.
We should only describe them at one place.
-->
<para>
The actions files are used to define what <emphasis>actions</emphasis>
<application>Privoxy</application> takes for which URLs, and thus determines
how ad images, cookies and various other aspects of HTTP content and
transactions are handled, and on which sites (or even parts thereof).
There are a number of such actions, with a wide range of functionality.
Each action does something a little different.
These actions give us a veritable arsenal of tools with which to exert
our control, preferences and independence. Actions can be combined so that
their effects are aggregated when applied against a given set of URLs.
</para>
<para>
There
are three action files included with <application>Privoxy</application> with
differing purposes:
</para>
<para>
<itemizedlist>
<listitem>
<para>
<filename>match-all.action</filename> - is used to define which
<quote>actions</quote> relating to banner-blocking, images, pop-ups,
content modification, cookie handling etc should be applied by default.
It should be the first actions file loaded
</para>
</listitem>
<listitem>
<para>
<filename>default.action</filename> - defines many exceptions (both
positive and negative) from the default set of actions that's configured
in <filename>match-all.action</filename>. It is a set of rules that should
work reasonably well as-is for most users. This file is only supposed to
be edited by the developers. It should be the second actions file loaded.
</para>
</listitem>
<listitem>
<para>
<filename>user.action</filename> - is intended to be for local site
preferences and exceptions. As an example, if your ISP or your bank
has specific requirements, and need special handling, this kind of
thing should go here. This file will not be upgraded.
</para>
</listitem>
<listitem>
<para>
<guibutton>Edit</guibutton> <guibutton>Set to Cautious</guibutton> <guibutton>Set to Medium</guibutton> <guibutton>Set to Advanced</guibutton>
</para>
<para>
These have increasing levels of aggressiveness <emphasis>and have no
influence on your browsing unless you select them explicitly in the
editor</emphasis>. A default installation should be pre-set to
<literal>Cautious</literal>. New users should try this for a while before
adjusting the settings to more aggressive levels. The more aggressive
the settings, then the more likelihood there is of problems such as sites
not working as they should.
</para>
<para>
The <guibutton>Edit</guibutton> button allows you to turn each
action on/off individually for fine-tuning. The <guibutton>Cautious</guibutton>
button changes the actions list to low/safe settings which will activate
ad blocking and a minimal set of &my-app;'s features, and subsequently
there will be less of a chance for accidental problems. The
<guibutton>Medium</guibutton> button sets the list to a medium level of
other features and a low level set of privacy features. The
<guibutton>Advanced</guibutton> button sets the list to a high level of
ad blocking and medium level of privacy. See the chart below. The latter
three buttons over-ride any changes via with the
<guibutton>Edit</guibutton> button. More fine-tuning can be done in the
lower sections of this internal page.
</para>
<para>
While the actions file editor allows to enable these settings in all
actions files, they are only supposed to be enabled in the first one
to make sure you don't unintentionally overrule earlier rules.
</para>
<para>
The default profiles, and their associated actions, as pre-defined in
<filename>default.action</filename> are:
</para>
<para>
<table frame=all><title>Default Configurations</title>
<tgroup cols=4 align=left colsep=1 rowsep=1>
<colspec colname=c1>
<colspec colname=c2>
<colspec colname=c3>
<colspec colname=c4>
<thead>
<row>
<entry>Feature</entry>
<entry>Cautious</entry>
<entry>Medium</entry>
<entry>Advanced</entry>
</row>
</thead>
<!-- <tfoot> -->
<!-- <row> -->
<!-- <entry>f1</entry> -->
<!-- <entry>f2</entry> -->
<!-- <entry>f3</entry> -->
<!-- <entry>f4</entry> -->
<!-- </row> -->
<!-- </tfoot> -->
<tbody>
<row>
<entry>Ad-blocking Aggressiveness</entry>
<entry>medium</entry>
<entry>high</entry>
<entry>high</entry>
</row>
<row>
<entry>Ad-filtering by size</entry>
<entry>no</entry>
<entry>yes</entry>
<entry>yes</entry>
</row>
<row>
<entry>Ad-filtering by link</entry>
<entry>no</entry>
<entry>no</entry>
<entry>yes</entry>
</row>
<row>
<entry>Pop-up killing</entry>
<entry>blocks only</entry>
<entry>blocks only</entry>
<entry>blocks only</entry>
</row>
<row>
<entry>Privacy Features</entry>
<entry>low</entry>
<entry>medium</entry>
<entry>medium/high</entry>
</row>
<row>
<entry>Cookie handling</entry>
<entry>none</entry>
<entry>session-only</entry>
<entry>kill</entry>
</row>
<row>
<entry>Referer forging</entry>
<entry>no</entry>
<entry>yes</entry>
<entry>yes</entry>
</row>
<row>
<entry>GIF de-animation</entry>
<entry>no</entry>
<entry>yes</entry>
<entry>yes</entry>
</row>
<row>
<entry>Fast redirects</entry>
<entry>no</entry>
<entry>no</entry>
<entry>yes</entry>
</row>
<row>
<entry>HTML taming</entry>
<entry>no</entry>
<entry>no</entry>
<entry>yes</entry>
</row>
<row>
<entry>JavaScript taming</entry>
<entry>no</entry>
<entry>no</entry>
<entry>yes</entry>
</row>
<row>
<entry>Web-bug killing</entry>
<entry>no</entry>
<entry>yes</entry>
<entry>yes</entry>
</row>
<row>
<entry>Image tag reordering</entry>
<entry>no</entry>
<entry>yes</entry>
<entry>yes</entry>
</row>
</tbody>
</tgroup>
</table>
</para>
</listitem>
</itemizedlist>
</para>
<para>
The list of actions files to be used are defined in the main configuration
file, and are processed in the order they are defined (e.g.
<filename>default.action</filename> is typically processed before
<filename>user.action</filename>). The content of these can all be viewed and
edited from <ulink
url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>.
The over-riding principle when applying actions, is that the last action that
matches a given URL wins. The broadest, most general rules go first
(defined in <filename>default.action</filename>),
followed by any exceptions (typically also in
<filename>default.action</filename>), which are then followed lastly by any
local preferences (typically in <emphasis>user</emphasis><filename>.action</filename>).
Generally, <filename>user.action</filename> has the last word.
</para>
<para>
An actions file typically has multiple sections. If you want to use
<quote>aliases</quote> in an actions file, you have to place the (optional)
<link linkend="aliases">alias section</link> at the top of that file.
Then comes the default set of rules which will apply universally to all
sites and pages (be <emphasis>very careful</emphasis> with using such a
universal set in <filename>user.action</filename> or any other actions file after
<filename>default.action</filename>, because it will override the result
from consulting any previous file). And then below that,
exceptions to the defined universal policies. You can regard
<filename>user.action</filename> as an appendix to <filename>default.action</filename>,
with the advantage that it is a separate file, which makes preserving your
personal settings across <application>Privoxy</application> upgrades easier.
</para>
<para>
Actions can be used to block anything you want, including ads, banners, or
just some obnoxious URL whose content you would rather not see. Cookies can be accepted
or rejected, or accepted only during the current browser session (i.e. not
written to disk), content can be modified, some JavaScripts tamed, user-tracking
fooled, and much more. See below for a <link linkend="actions">complete list
of actions</link>.
</para>
<!-- ~~~~~ New section ~~~~~ -->
<sect2>
<title>Finding the Right Mix</title>
<para>
Note that some <link linkend="actions">actions</link>, like cookie suppression
or script disabling, may render some sites unusable that rely on these
techniques to work properly. Finding the right mix of actions is not always easy and
certainly a matter of personal taste. And, things can always change, requiring
refinements in the configuration. In general, it can be said that the more
<quote>aggressive</quote> your default settings (in the top section of the
actions file) are, the more exceptions for <quote>trusted</quote> sites you
will have to make later. If, for example, you want to crunch all cookies per
default, you'll have to make exceptions from that rule for sites that you
regularly use and that require cookies for actually useful purposes, like maybe
your bank, favorite shop, or newspaper.
</para>
<para>
We have tried to provide you with reasonable rules to start from in the
distribution actions files. But there is no general rule of thumb on these
things. There just are too many variables, and sites are constantly changing.
Sooner or later you will want to change the rules (and read this chapter again :).
</para>
</sect2>
<!-- ~~~~~ New section ~~~~~ -->
<sect2>
<title>How to Edit</title>
<para>
The easiest way to edit the actions files is with a browser by
using our browser-based editor, which can be reached from <ulink
url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>.
Note: the config file option <link
linkend="enable-edit-actions">enable-edit-actions</link> must be enabled for
this to work. The editor allows both fine-grained control over every single
feature on a per-URL basis, and easy choosing from wholesale sets of defaults
like <quote>Cautious</quote>, <quote>Medium</quote> or
<quote>Advanced</quote>. Warning: the <quote>Advanced</quote> setting is more
aggressive, and will be more likely to cause problems for some sites.
Experienced users only!
</para>
<para>
If you prefer plain text editing to GUIs, you can of course also directly edit the
the actions files with your favorite text editor. Look at
<filename>default.action</filename> which is richly commented with many
good examples.
</para>
</sect2>
<sect2 id="actions-apply">
<title>How Actions are Applied to Requests</title>
<para>
Actions files are divided into sections. There are special sections,
like the <quote><link linkend="aliases">alias</link></quote> sections which will
be discussed later. For now let's concentrate on regular sections: They have a
heading line (often split up to multiple lines for readability) which consist
of a list of actions, separated by whitespace and enclosed in curly braces.
Below that, there is a list of URL and tag patterns, each on a separate line.
</para>
<para>
To determine which actions apply to a request, the URL of the request is
compared to all URL patterns in each <quote>action file</quote>.
Every time it matches, the list of applicable actions for the request is
incrementally updated, using the heading of the section in which the
pattern is located. The same is done again for tags and tag patterns later on.
</para>
<para>
If multiple applying sections set the same action differently,
the last match wins. If not, the effects are aggregated.
E.g. a URL might match a regular section with a heading line of <literal>{
+<link linkend="handle-as-image">handle-as-image</link> }</literal>,
then later another one with just <literal>{
+<link linkend="block">block</link> }</literal>, resulting
in <emphasis>both</emphasis> actions to apply. And there may well be
cases where you will want to combine actions together. Such a section then
might look like:
</para>
<para>
<screen>
{ +<literal>handle-as-image</literal> +<literal>block{Banner ads.}</literal> }
# Block these as if they were images. Send no block page.
banners.example.com
media.example.com/.*banners
.example.com/images/ads/</screen>
</para>
<para>
You can trace this process for URL patterns and any given URL by visiting <ulink
url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>.
</para>
<para>
Examples and more detail on this is provided in the Appendix, <link linkend="ACTIONSANAT">
Troubleshooting: Anatomy of an Action</link> section.
</para>
</sect2>
<!-- ~~~~~ New section ~~~~~ -->
<sect2 id="af-patterns">
<title>Patterns</title>
<para>
As mentioned, <application>Privoxy</application> uses <quote>patterns</quote>
to determine what <emphasis>actions</emphasis> might apply to which sites and
pages your browser attempts to access. These <quote>patterns</quote> use wild
card type <emphasis>pattern</emphasis> matching to achieve a high degree of
flexibility. This allows one expression to be expanded and potentially match
against many similar patterns.
</para>
<para>
Generally, an URL pattern has the form
<literal>&lt;domain&gt;/&lt;path&gt;</literal>, where both the
<literal>&lt;domain&gt;</literal> and <literal>&lt;path&gt;</literal> are
optional. (This is why the special <literal>/</literal> pattern matches all
URLs). Note that the protocol portion of the URL pattern (e.g.
<literal>http://</literal>) should <emphasis>not</emphasis> be included in
the pattern. This is assumed already!
</para>
<para>
The pattern matching syntax is different for the domain and path parts of
the URL. The domain part uses a simple globbing type matching technique,
while the path part uses more flexible
<ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
Expressions</quote></ulink> (POSIX 1003.2).
</para>
<variablelist>
<varlistentry>
<term><literal>www.example.com/</literal></term>
<listitem>
<para>
is a domain-only pattern and will match any request to <literal>www.example.com</literal>,
regardless of which document on that server is requested. So ALL pages in
this domain would be covered by the scope of this action. Note that a
simple <literal>example.com</literal> is different and would NOT match.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>www.example.com</literal></term>
<listitem>
<para>
means exactly the same. For domain-only patterns, the trailing <literal>/</literal> may
be omitted.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>www.example.com/index.html</literal></term>
<listitem>
<para>
matches all the documents on <literal>www.example.com</literal>
whose name starts with <literal>/index.html</literal>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>www.example.com/index.html$</literal></term>
<listitem>
<para>
matches only the single document <literal>/index.html</literal>
on <literal>www.example.com</literal>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>/index.html$</literal></term>
<listitem>
<para>
matches the document <literal>/index.html</literal>, regardless of the domain,
i.e. on <emphasis>any</emphasis> web server anywhere.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>index.html</literal></term>
<listitem>
<para>
matches nothing, since it would be interpreted as a domain name and
there is no top-level domain called <literal>.html</literal>. So its
a mistake.
</para>
</listitem>
</varlistentry>
</variablelist>
<!-- ~~~~~ New section ~~~~~ -->
<sect3><title>The Domain Pattern</title>
<para>
The matching of the domain part offers some flexible options: if the
domain starts or ends with a dot, it becomes unanchored at that end.
For example:
</para>
<variablelist>
<varlistentry>
<term><literal>.example.com</literal></term>
<listitem>
<para>
matches any domain with first-level domain <literal>com</literal>
and second-level domain <literal>example</literal>.
For example <literal>www.example.com</literal>,
<literal>example.com</literal> and <literal>foo.bar.baz.example.com</literal>.
Note that it wouldn't match if the second-level domain was <literal>another-example</literal>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>www.</literal></term>
<listitem>
<para>
matches any domain that <emphasis>STARTS</emphasis> with
<literal>www.</literal> (It also matches the domain
<literal>www</literal> but most of the time that doesn't matter.)
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>.example.</literal></term>
<listitem>
<para>
matches any domain that <emphasis>CONTAINS</emphasis> <literal>.example.</literal>.
And, by the way, also included would be any files or documents that exist
within that domain since no path limitations are specified. (Correctly
speaking: It matches any FQDN that contains <literal>example</literal> as
a domain.) This might be <literal>www.example.com</literal>,
<literal>news.example.de</literal>, or
<literal>www.example.net/cgi/testing.pl</literal> for instance. All these
cases are matched.
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
Additionally, there are wild-cards that you can use in the domain names
themselves. These work similarly to shell globbing type wild-cards:
<quote>*</quote> represents zero or more arbitrary characters (this is
equivalent to the
<ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
Expression</quote></ulink> based syntax of <quote>.*</quote>),
<quote>?</quote> represents any single character (this is equivalent to the
regular expression syntax of a simple <quote>.</quote>), and you can define
<quote>character classes</quote> in square brackets which is similar to
the same regular expression technique. All of this can be freely mixed:
</para>
<variablelist>
<varlistentry>
<term><literal>ad*.example.com</literal></term>
<listitem>
<para>
matches <quote>adserver.example.com</quote>,
<quote>ads.example.com</quote>, etc but not <quote>sfads.example.com</quote>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>*ad*.example.com</literal></term>
<listitem>
<para>
matches all of the above, and then some.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>.?pix.com</literal></term>
<listitem>
<para>
matches <literal>www.ipix.com</literal>,
<literal>pictures.epix.com</literal>, <literal>a.b.c.d.e.upix.com</literal> etc.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>www[1-9a-ez].example.c*</literal></term>
<listitem>
<para>
matches <literal>www1.example.com</literal>,
<literal>www4.example.cc</literal>, <literal>wwwd.example.cy</literal>,
<literal>wwwz.example.com</literal> etc., but <emphasis>not</emphasis>
<literal>wwww.example.com</literal>.
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
While flexible, this is not the sophistication of full regular expression based syntax.
</para>
</sect3>
<!-- ~ End section ~ -->
<!-- ~~~~~ New section ~~~~~ -->
<sect3><title>The Path Pattern</title>
<para>
<application>Privoxy</application> uses <quote>modern</quote> POSIX 1003.2
<ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
Expressions</quote></ulink> for matching the path portion (after the slash),
and is thus more flexible.
</para>
<para>
There is an <link linkend="regex">Appendix</link> with a brief quick-start into regular
expressions, you also might want to have a look at your operating system's documentation
on regular expressions (try <literal>man re_format</literal>).
</para>
<para>
Note that the path pattern is automatically left-anchored at the <quote>/</quote>,
i.e. it matches as if it would start with a <quote>^</quote> (regular expression speak
for the beginning of a line).
</para>
<para>
Please also note that matching in the path is <emphasis>CASE INSENSITIVE</emphasis>
by default, but you can switch to case sensitive at any point in the pattern by using the
<quote>(?-i)</quote> switch: <literal>www.example.com/(?-i)PaTtErN.*</literal> will match
only documents whose path starts with <literal>PaTtErN</literal> in
<emphasis>exactly</emphasis> this capitalization.
</para>
<variablelist>
<varlistentry>
<term><literal>.example.com/.*</literal></term>
<listitem>
<para>
Is equivalent to just <quote>.example.com</quote>, since any documents
within that domain are matched with or without the <quote>.*</quote>
regular expression. This is redundant
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>.example.com/.*/index.html$</literal></term>
<listitem>
<para>
Will match any page in the domain of <quote>example.com</quote> that is
named <quote>index.html</quote>, and that is part of some path. For
example, it matches <quote>www.example.com/testing/index.html</quote> but
NOT <quote>www.example.com/index.html</quote> because the regular
expression called for at least two <quote>/'s</quote>, thus the path
requirement. It also would match
<quote>www.example.com/testing/index_html</quote>, because of the
special meta-character <quote>.</quote>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>.example.com/(.*/)?index\.html$</literal></term>
<listitem>
<para>
This regular expression is conditional so it will match any page
named <quote>index.html</quote> regardless of path which in this case can
have one or more <quote>/'s</quote>. And this one must contain exactly
<quote>.html</quote> (but does not have to end with that!).
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>.example.com/(.*/)(ads|banners?|junk)</literal></term>
<listitem>
<para>
This regular expression will match any path of <quote>example.com</quote>
that contains any of the words <quote>ads</quote>, <quote>banner</quote>,
<quote>banners</quote> (because of the <quote>?</quote>) or <quote>junk</quote>.
The path does not have to end in these words, just contain them.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><literal>.example.com/(.*/)(ads|banners?|junk)/.*\.(jpe?g|gif|png)$</literal></term>
<listitem>
<para>
This is very much the same as above, except now it must end in either
<quote>.jpg</quote>, <quote>.jpeg</quote>, <quote>.gif</quote> or <quote>.png</quote>. So this
one is limited to common image formats.
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
There are many, many good examples to be found in <filename>default.action</filename>,
and more tutorials below in <link linkend="regex">Appendix on regular expressions</link>.
</para>
</sect3>
<!-- ~ End section ~ -->
<!-- ~~~~~ New section ~~~~~ -->
<sect3 id="tag-pattern"><title>The Tag Pattern</title>
<para>
Tag patterns are used to change the applying actions based on the
request's tags. Tags can be created with either the
<link linkend="CLIENT-HEADER-TAGGER">client-header-tagger</link>
or the <link linkend="SERVER-HEADER-TAGGER">server-header-tagger</link> action.
</para>
<para>
Tag patterns have to start with <quote>TAG:</quote>, so &my-app;
can tell them apart from URL patterns. Everything after the colon
including white space, is interpreted as a regular expression with
path pattern syntax, except that tag patterns aren't left-anchored
automatically (&my-app; doesn't silently add a <quote>^</quote>,
you have to do it yourself if you need it).
</para>
<para>
To match all requests that are tagged with <quote>foo</quote>
your pattern line should be <quote>TAG:^foo$</quote>,
<quote>TAG:foo</quote> would work as well, but it would also
match requests whose tags contain <quote>foo</quote> somewhere.
<quote>TAG: foo</quote> wouldn't work as it requires white space.
</para>
<para>
Sections can contain URL and tag patterns at the same time,
but tag patterns are checked after the URL patterns and thus
always overrule them, even if they are located before the URL patterns.
</para>
<para>
Once a new tag is added, Privoxy checks right away if it's matched by one
of the tag patterns and updates the action settings accordingly. As a result
tags can be used to activate other tagger actions, as long as these other
taggers look for headers that haven't already be parsed.
</para>
<para>
For example you could tag client requests which use the
<literal>POST</literal> method,
then use this tag to activate another tagger that adds a tag if cookies
are sent, and then use a block action based on the cookie tag. This allows
the outcome of one action, to be input into a subsequent action. However if
you'd reverse the position of the described taggers, and activated the
method tagger based on the cookie tagger, no method tags would be created.
The method tagger would look for the request line, but at the time
the cookie tag is created, the request line has already been parsed.
</para>
<para>
While this is a limitation you should be aware of, this kind of
indirection is seldom needed anyway and even the example doesn't
make too much sense.
</para>
</sect3>
</sect2>
<!-- ~ End section ~ -->
<!-- ~~~~~ New section ~~~~~ -->
<sect2 id="actions">
<title>Actions</title>
<para>
All actions are disabled by default, until they are explicitly enabled
somewhere in an actions file. Actions are turned on if preceded with a
<quote>+</quote>, and turned off if preceded with a <quote>-</quote>. So a
<literal>+action</literal> means <quote>do that action</quote>, e.g.
<literal>+block</literal> means <quote>please block URLs that match the
following patterns</quote>, and <literal>-block</literal> means <quote>don't
block URLs that match the following patterns, even if <literal>+block</literal>
previously applied.</quote>
</para>
<para>
Again, actions are invoked by placing them on a line, enclosed in curly braces and
separated by whitespace, like in
<literal>{+some-action -some-other-action{some-parameter}}</literal>,
followed by a list of URL patterns, one per line, to which they apply.
Together, the actions line and the following pattern lines make up a section
of the actions file.
</para>
<para>
Actions fall into three categories:
</para>
<para>
<itemizedlist>
<listitem>
<para>
Boolean, i.e the action can only be <quote>enabled</quote> or
<quote>disabled</quote>. Syntax:
</para>
<para>
<screen>
+<replaceable class="function">name</replaceable> # enable action <replaceable class="parameter">name</replaceable>
-<replaceable class="function">name</replaceable> # disable action <replaceable class="parameter">name</replaceable></screen>
</para>
<para>
Example: <literal>+handle-as-image</literal>
</para>
</listitem>
<listitem>
<para>
Parameterized, where some value is required in order to enable this type of action.
Syntax:
</para>
<para>
<screen>
+<replaceable class="function">name</replaceable>{<replaceable class="parameter">param</replaceable>} # enable action and set parameter to <replaceable class="parameter">param</replaceable>,
# overwriting parameter from previous match if necessary
-<replaceable class="function">name</replaceable> # disable action. The parameter can be omitted</screen>
</para>
<para>
Note that if the URL matches multiple positive forms of a parameterized action,
the last match wins, i.e. the params from earlier matches are simply ignored.
</para>
<para>
Example: <literal>+hide-user-agent{Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.8.1.4) Gecko/20070602 Firefox/2.0.0.4}</literal>
</para>
</listitem>
<listitem>
<para>
Multi-value. These look exactly like parameterized actions,
but they behave differently: If the action applies multiple times to the
same URL, but with different parameters, <emphasis>all</emphasis> the parameters
from <emphasis>all</emphasis> matches are remembered. This is used for actions
that can be executed for the same request repeatedly, like adding multiple
headers, or filtering through multiple filters. Syntax:
</para>
<para>
<screen>
+<replaceable class="function">name</replaceable>{<replaceable class="parameter">param</replaceable>} # enable action and add <replaceable class="parameter">param</replaceable> to the list of parameters
-<replaceable class="function">name</replaceable>{<replaceable class="parameter">param</replaceable>} # remove the parameter <replaceable class="parameter">param</replaceable> from the list of parameters
# If it was the last one left, disable the action.
<replaceable class="parameter">-name</replaceable> # disable this action completely and remove all parameters from the list</screen>
</para>
<para>
Examples: <literal>+add-header{X-Fun-Header: Some text}</literal> and
<literal>+filter{html-annoyances}</literal>
</para>
</listitem>
</itemizedlist>
</para>
<para>
If nothing is specified in any actions file, no <quote>actions</quote> are
taken. So in this case <application>Privoxy</application> would just be a
normal, non-blocking, non-filtering proxy. You must specifically enable the
privacy and blocking features you need (although the provided default actions
files will give a good starting point).
</para>
<para>
Later defined action sections always over-ride earlier ones of the same type.
So exceptions to any rules you make, should come in the latter part of the file (or
in a file that is processed later when using multiple actions files such
as <filename>user.action</filename>). For multi-valued actions, the actions
are applied in the order they are specified. Actions files are processed in
the order they are defined in <filename>config</filename> (the default
installation has three actions files). It also quite possible for any given
URL to match more than one <quote>pattern</quote> (because of wildcards and
regular expressions), and thus to trigger more than one set of actions! Last
match wins.
</para>
<!-- start actions listing -->
<para>
The list of valid <application>Privoxy</application> actions are:
</para>
<!-- ********************************************************** -->
<!-- Please note the below defined actions use id's that are -->
<!-- probably linked from other places, so please don't change. -->
<!-- -->
<!-- ********************************************************** -->
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="add-header">
<title>add-header</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Confuse log analysis, custom applications</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Sends a user defined HTTP header to the web server.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- boolean, parameterized, Multi-value -->
<listitem>
<para>Multi-value.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
Any string value is possible. Validity of the defined HTTP headers is not checked.
It is recommended that you use the <quote><literal>X-</literal></quote> prefix
for custom headers.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
This action may be specified multiple times, in order to define multiple
headers. This is rarely needed for the typical user. If you don't know what
<quote>HTTP headers</quote> are, you definitely don't need to worry about this
one.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage:</term>
<listitem>
<para>
<screen>+add-header{X-User-Tracking: sucks}</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="block">
<title>block</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Block ads or other unwanted content</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Requests for URLs to which this action applies are blocked, i.e. the
requests are trapped by &my-app; and the requested URL is never retrieved,
but is answered locally with a substitute page or image, as determined by
the <literal><link
linkend="handle-as-image">handle-as-image</link></literal>,
<literal><link
linkend="set-image-blocker">set-image-blocker</link></literal>, and
<literal><link
linkend="handle-as-empty-document">handle-as-empty-document</link></literal> actions.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- boolean, parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>A block reason that should be given to the user.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
<application>Privoxy</application> sends a special <quote>BLOCKED</quote> page
for requests to blocked pages. This page contains the block reason given as
parameter, a link to find out why the block action applies, and a click-through
to the blocked content (the latter only if the force feature is available and
enabled).
</para>
<para>
A very important exception occurs if <emphasis>both</emphasis>
<literal>block</literal> and <literal><link linkend="handle-as-image">handle-as-image</link></literal>,
apply to the same request: it will then be replaced by an image. If
<literal><link linkend="set-image-blocker">set-image-blocker</link></literal>
(see below) also applies, the type of image will be determined by its parameter,
if not, the standard checkerboard pattern is sent.
</para>
<para>
It is important to understand this process, in order
to understand how <application>Privoxy</application> deals with
ads and other unwanted content. Blocking is a core feature, and one
upon which various other features depend.
</para>
<para>
The <literal><link linkend="filter">filter</link></literal>
action can perform a very similar task, by <quote>blocking</quote>
banner images and other content through rewriting the relevant URLs in the
document's HTML source, so they don't get requested in the first place.
Note that this is a totally different technique, and it's easy to confuse the two.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage (section):</term>
<listitem>
<para>
<screen>{+block{No nasty stuff for you.}}
# Block and replace with "blocked" page
.nasty-stuff.example.com
{+block{Doubleclick banners.} +handle-as-image}
# Block and replace with image
.ad.doubleclick.net
.ads.r.us/banners/
{+block{Layered ads.} +handle-as-empty-document}
# Block and then ignore
adserver.example.net/.*\.js$</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="change-x-forwarded-for">
<title>change-x-forwarded-for</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Improve privacy by not forwarding the source of the request in the HTTP headers.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Deletes the <quote>X-Forwarded-For:</quote> HTTP header from the client request,
or adds a new one.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<itemizedlist>
<listitem>
<para><quote>block</quote> to delete the header.</para>
</listitem>
<listitem>
<para>
<quote>add</quote> to create the header (or append
the client's IP address to an already existing one).
</para>
</listitem>
</itemizedlist>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
It is safe and recommended to use <literal>block</literal>.
</para>
<para>
Forwarding the source address of the request may make
sense in some multi-user setups but is also a privacy risk.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage:</term>
<listitem>
<para>
<screen>+change-x-forwarded-for{block}</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="client-header-filter">
<title>client-header-filter</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>
Rewrite or remove single client headers.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
All client headers to which this action applies are filtered on-the-fly through
the specified regular expression based substitutions.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- boolean, parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
The name of a client-header filter, as defined in one of the
<link linkend="filter-file">filter files</link>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
Client-header filters are applied to each header on its own, not to
all at once. This makes it easier to diagnose problems, but on the downside
you can't write filters that only change header x if header y's value is z.
You can do that by using tags though.
</para>
<para>
Client-header filters are executed after the other header actions have finished
and use their output as input.
</para>
<para>
If the request URL gets changed, &my-app; will detect that and use the new
one. This can be used to rewrite the request destination behind the client's
back, for example to specify a Tor exit relay for certain requests.
</para>
<para>
Please refer to the <link linkend="filter-file">filter file chapter</link>
to learn which client-header filters are available by default, and how to
create your own.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage (section):</term>
<listitem>
<para>
<screen>
# Hide Tor exit notation in Host and Referer Headers
{+client-header-filter{hide-tor-exit-notation}}
/
</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="client-header-tagger">
<title>client-header-tagger</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>
Block requests based on their headers.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Client headers to which this action applies are filtered on-the-fly through
the specified regular expression based substitutions, the result is used as
tag.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- boolean, parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
The name of a client-header tagger, as defined in one of the
<link linkend="filter-file">filter files</link>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
Client-header taggers are applied to each header on its own,
and as the header isn't modified, each tagger <quote>sees</quote>
the original.
</para>
<para>
Client-header taggers are the first actions that are executed
and their tags can be used to control every other action.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage (section):</term>
<listitem>
<para>
<screen>
# Tag every request with the User-Agent header
{+client-header-tagger{user-agent}}
/
# Tagging itself doesn't change the action
# settings, sections with TAG patterns do:
#
# If it's a download agent, use a different forwarding proxy,
# show the real User-Agent and make sure resume works.
{+forward-override{forward-socks5 10.0.0.2:2222 .} \
-hide-if-modified-since \
-overwrite-last-modified \
-hide-user-agent \
-filter \
-deanimate-gifs \
}
TAG:^User-Agent: NetBSD-ftp/
TAG:^User-Agent: Novell ZYPP Installer
TAG:^User-Agent: RPM APT-HTTP/
TAG:^User-Agent: fetch libfetch/
TAG:^User-Agent: Ubuntu APT-HTTP/
TAG:^User-Agent: MPlayer/
</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="content-type-overwrite">
<title>content-type-overwrite</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Stop useless download menus from popping up, or change the browser's rendering mode</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Replaces the <quote>Content-Type:</quote> HTTP server header.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
Any string.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
The <quote>Content-Type:</quote> HTTP server header is used by the
browser to decide what to do with the document. The value of this
header can cause the browser to open a download menu instead of
displaying the document by itself, even if the document's format is
supported by the browser.
</para>
<para>
The declared content type can also affect which rendering mode
the browser chooses. If XHTML is delivered as <quote>text/html</quote>,
many browsers treat it as yet another broken HTML document.
If it is send as <quote>application/xml</quote>, browsers with
XHTML support will only display it, if the syntax is correct.
</para>
<para>
If you see a web site that proudly uses XHTML buttons, but sets
<quote>Content-Type: text/html</quote>, you can use &my-app;
to overwrite it with <quote>application/xml</quote> and validate
the web master's claim inside your XHTML-supporting browser.
If the syntax is incorrect, the browser will complain loudly.
</para>
<para>
You can also go the opposite direction: if your browser prints
error messages instead of rendering a document falsely declared
as XHTML, you can overwrite the content type with
<quote>text/html</quote> and have it rendered as broken HTML document.
</para>
<para>
By default <literal>content-type-overwrite</literal> only replaces
<quote>Content-Type:</quote> headers that look like some kind of text.
If you want to overwrite it unconditionally, you have to combine it with
<literal><link linkend="force-text-mode">force-text-mode</link></literal>.
This limitation exists for a reason, think twice before circumventing it.
</para>
<para>
Most of the time it's easier to replace this action with a custom
<literal><link linkend="server-header-filter">server-header filter</link></literal>.
It allows you to activate it for every document of a certain site and it will still
only replace the content types you aimed at.
</para>
<para>
Of course you can apply <literal>content-type-overwrite</literal>
to a whole site and then make URL based exceptions, but it's a lot
more work to get the same precision.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage (sections):</term>
<listitem>
<para>
<screen># Check if www.example.net/ really uses valid XHTML
{ +content-type-overwrite{application/xml} }
www.example.net/
# but leave the content type unmodified if the URL looks like a style sheet
{-content-type-overwrite}
www.example.net/.*\.css$
www.example.net/.*style
</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="crunch-client-header">
<!--
new action
-->
<title>crunch-client-header</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Remove a client header <application>Privoxy</application> has no dedicated action for.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Deletes every header sent by the client that contains the string the user supplied as parameter.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
Any string.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
This action allows you to block client headers for which no dedicated
<application>Privoxy</application> action exists.
<application>Privoxy</application> will remove every client header that
contains the string you supplied as parameter.
</para>
<para>
Regular expressions are <emphasis>not supported</emphasis> and you can't
use this action to block different headers in the same request, unless
they contain the same string.
</para>
<para>
<literal>crunch-client-header</literal> is only meant for quick tests.
If you have to block several different headers, or only want to modify
parts of them, you should use a
<literal><link linkend="client-header-filter">client-header filter</link></literal>.
</para>
<warning>
<para>
Don't block any header without understanding the consequences.
</para>
</warning>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage (section):</term>
<listitem>
<para>
<screen># Block the non-existent "Privacy-Violation:" client header
{ +crunch-client-header{Privacy-Violation:} }
/
</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="crunch-if-none-match">
<title>crunch-if-none-match</title>
<!--
new action
-->
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Prevent yet another way to track the user's steps between sessions.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Deletes the <quote>If-None-Match:</quote> HTTP client header.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Boolean.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
N/A
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
Removing the <quote>If-None-Match:</quote> HTTP client header
is useful for filter testing, where you want to force a real
reload instead of getting status code <quote>304</quote> which
would cause the browser to use a cached copy of the page.
</para>
<para>
It is also useful to make sure the header isn't used as a cookie
replacement (unlikely but possible).
</para>
<para>
Blocking the <quote>If-None-Match:</quote> header shouldn't cause any
caching problems, as long as the <quote>If-Modified-Since:</quote> header
isn't blocked or missing as well.
</para>
<para>
It is recommended to use this action together with
<literal><link linkend="hide-if-modified-since">hide-if-modified-since</link></literal>
and
<literal><link linkend="overwrite-last-modified">overwrite-last-modified</link></literal>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage (section):</term>
<listitem>
<para>
<screen># Let the browser revalidate cached documents but don't
# allow the server to use the revalidation headers for user tracking.
{+hide-if-modified-since{-60} \
+overwrite-last-modified{randomize} \
+crunch-if-none-match}
/ </screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="crunch-incoming-cookies">
<title>crunch-incoming-cookies</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>
Prevent the web server from setting HTTP cookies on your system
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Deletes any <quote>Set-Cookie:</quote> HTTP headers from server replies.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Boolean.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
N/A
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
This action is only concerned with <emphasis>incoming</emphasis> HTTP cookies. For
<emphasis>outgoing</emphasis> HTTP cookies, use
<literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal>.
Use <emphasis>both</emphasis> to disable HTTP cookies completely.
</para>
<para>
It makes <emphasis>no sense at all</emphasis> to use this action in conjunction
with the <literal><link linkend="session-cookies-only">session-cookies-only</link></literal> action,
since it would prevent the session cookies from being set. See also
<literal><link linkend="filter-content-cookies">filter-content-cookies</link></literal>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage:</term>
<listitem>
<para>
<screen>+crunch-incoming-cookies</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="crunch-server-header">
<title>crunch-server-header</title>
<!--
new action
-->
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Remove a server header <application>Privoxy</application> has no dedicated action for.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Deletes every header sent by the server that contains the string the user supplied as parameter.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
Any string.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
This action allows you to block server headers for which no dedicated
<application>Privoxy</application> action exists. <application>Privoxy</application>
will remove every server header that contains the string you supplied as parameter.
</para>
<para>
Regular expressions are <emphasis>not supported</emphasis> and you can't
use this action to block different headers in the same request, unless
they contain the same string.
</para>
<para>
<literal>crunch-server-header</literal> is only meant for quick tests.
If you have to block several different headers, or only want to modify
parts of them, you should use a custom
<literal><link linkend="server-header-filter">server-header filter</link></literal>.
</para>
<warning>
<para>
Don't block any header without understanding the consequences.
</para>
</warning>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage (section):</term>
<listitem>
<para>
<screen># Crunch server headers that try to prevent caching
{ +crunch-server-header{no-cache} }
/ </screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="crunch-outgoing-cookies">
<title>crunch-outgoing-cookies</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>
Prevent the web server from reading any HTTP cookies from your system
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Deletes any <quote>Cookie:</quote> HTTP headers from client requests.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Boolean.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
N/A
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
This action is only concerned with <emphasis>outgoing</emphasis> HTTP cookies. For
<emphasis>incoming</emphasis> HTTP cookies, use
<literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal>.
Use <emphasis>both</emphasis> to disable HTTP cookies completely.
</para>
<para>
It makes <emphasis>no sense at all</emphasis> to use this action in conjunction
with the <literal><link linkend="session-cookies-only">session-cookies-only</link></literal> action,
since it would prevent the session cookies from being read.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage:</term>
<listitem>
<para>
<screen>+crunch-outgoing-cookies</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="deanimate-gifs">
<title>deanimate-gifs</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Stop those annoying, distracting animated GIF images.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
De-animate GIF animations, i.e. reduce them to their first or last image.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- boolean, parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
<quote>last</quote> or <quote>first</quote>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
This will also shrink the images considerably (in bytes, not pixels!). If
the option <quote>first</quote> is given, the first frame of the animation
is used as the replacement. If <quote>last</quote> is given, the last
frame of the animation is used instead, which probably makes more sense for
most banner animations, but also has the risk of not showing the entire
last frame (if it is only a delta to an earlier frame).
</para>
<para>
You can safely use this action with patterns that will also match non-GIF
objects, because no attempt will be made at anything that doesn't look like
a GIF.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage:</term>
<listitem>
<para>
<screen>+deanimate-gifs{last}</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="downgrade-http-version">
<title>downgrade-http-version</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Work around (very rare) problems with HTTP/1.1</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- boolean, parameterized, Multi-value -->
<listitem>
<para>Boolean.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
N/A
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
This is a left-over from the time when <application>Privoxy</application>
didn't support important HTTP/1.1 features well. It is left here for the
unlikely case that you experience HTTP/1.1 related problems with some server
out there. Not all HTTP/1.1 features and requirements are supported yet,
so there is a chance you might need this action.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage (section):</term>
<listitem>
<para>
<screen>{+downgrade-http-version}
problem-host.example.com</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="fast-redirects">
<title>fast-redirects</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Fool some click-tracking scripts and speed up indirect links.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Detects redirection URLs and redirects the browser without contacting
the redirection server first.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- boolean, parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<itemizedlist>
<listitem>
<para>
<quote>simple-check</quote> to just search for the string <quote>http://</quote>
to detect redirection URLs.
</para>
</listitem>
<listitem>
<para>
<quote>check-decoded-url</quote> to decode URLs (if necessary) before searching
for redirection URLs.
</para>
</listitem>
</itemizedlist>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
Many sites, like yahoo.com, don't just link to other sites. Instead, they
will link to some script on their own servers, giving the destination as a
parameter, which will then redirect you to the final target. URLs
resulting from this scheme typically look like:
<quote>http://www.example.org/click-tracker.cgi?target=http%3a//www.example.net/</quote>.
</para>
<para>
Sometimes, there are even multiple consecutive redirects encoded in the
URL. These redirections via scripts make your web browsing more traceable,
since the server from which you follow such a link can see where you go
to. Apart from that, valuable bandwidth and time is wasted, while your
browser asks the server for one redirect after the other. Plus, it feeds
the advertisers.
</para>
<para>
This feature is currently not very smart and is scheduled for improvement.
If it is enabled by default, you will have to create some exceptions to
this action. It can lead to failures in several ways:
</para>
<para>
Not every URLs with other URLs as parameters is evil.
Some sites offer a real service that requires this information to work.
For example a validation service needs to know, which document to validate.
<literal>fast-redirects</literal> assumes that every URL parameter that
looks like another URL is a redirection target, and will always redirect to
the last one. Most of the time the assumption is correct, but if it isn't,
the user gets redirected anyway.
</para>
<para>
Another failure occurs if the URL contains other parameters after the URL parameter.
The URL:
<quote>http://www.example.org/?redirect=http%3a//www.example.net/&amp;foo=bar</quote>.
contains the redirection URL <quote>http://www.example.net/</quote>,
followed by another parameter. <literal>fast-redirects</literal> doesn't know that
and will cause a redirect to <quote>http://www.example.net/&amp;foo=bar</quote>.
Depending on the target server configuration, the parameter will be silently ignored
or lead to a <quote>page not found</quote> error. You can prevent this problem by
first using the <literal><link linkend="redirect">redirect</link></literal> action
to remove the last part of the URL, but it requires a little effort.
</para>
<para>
To detect a redirection URL, <literal>fast-redirects</literal> only
looks for the string <quote>http://</quote>, either in plain text
(invalid but often used) or encoded as <quote>http%3a//</quote>.
Some sites use their own URL encoding scheme, encrypt the address
of the target server or replace it with a database id. In theses cases
<literal>fast-redirects</literal> is fooled and the request reaches the
redirection server where it probably gets logged.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage:</term>
<listitem>
<para>
<screen>
{ +fast-redirects{simple-check} }
one.example.com
{ +fast-redirects{check-decoded-url} }
another.example.com/testing</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="filter">
<title>filter</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Get rid of HTML and JavaScript annoyances, banner advertisements (by size),
do fun text replacements, add personalized effects, etc.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
All instances of text-based type, most notably HTML and JavaScript, to which
this action applies, can be filtered on-the-fly through the specified regular
expression based substitutions. (Note: as of version 3.0.3 plain text documents
are exempted from filtering, because web servers often use the
<literal>text/plain</literal> MIME type for all files whose type they don't know.)
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- boolean, parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
The name of a content filter, as defined in the <link linkend="filter-file">filter file</link>.
Filters can be defined in one or more files as defined by the
<literal><link linkend="filterfile">filterfile</link></literal>
option in the <link linkend="config">config file</link>.
<filename>default.filter</filename> is the collection of filters
supplied by the developers. Locally defined filters should go
in their own file, such as <filename>user.filter</filename>.
</para>
<para>
When used in its negative form,
and without parameters, <emphasis>all</emphasis> filtering is completely disabled.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
For your convenience, there are a number of pre-defined filters available
in the distribution filter file that you can use. See the examples below for
a list.
</para>
<para>
Filtering requires buffering the page content, which may appear to
slow down page rendering since nothing is displayed until all content has
passed the filters. (It does not really take longer, but seems that way
since the page is not incrementally displayed.) This effect will be more
noticeable on slower connections.
</para>
<para>
<quote>Rolling your own</quote>
filters requires a knowledge of
<ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
Expressions</quote></ulink> and
<ulink url="http://en.wikipedia.org/wiki/Html"><quote>HTML</quote></ulink>.
This is very powerful feature, and potentially very intrusive.
Filters should be used with caution, and where an equivalent
<quote>action</quote> is not available.
</para>
<para>
The amount of data that can be filtered is limited to the
<literal><link linkend="buffer-limit">buffer-limit</link></literal>
option in the main <link linkend="config">config file</link>. The
default is 4096 KB (4 Megs). Once this limit is exceeded, the buffered
data, and all pending data, is passed through unfiltered.
</para>
<para>
Inappropriate MIME types, such as zipped files, are not filtered at all.
(Again, only text-based types except plain text). Encrypted SSL data
(from HTTPS servers) cannot be filtered either, since this would violate
the integrity of the secure transaction. In some situations it might
be necessary to protect certain text, like source code, from filtering
by defining appropriate <literal>-filter</literal> exceptions.
</para>
<para>
Compressed content can't be filtered either, unless &my-app;
is compiled with zlib support (requires at least &my-app; 3.0.7),
in which case &my-app; will decompress the content before filtering
it.
</para>
<para>
If you use a &my-app; version without zlib support, but want filtering to work on
as much documents as possible, even those that would normally be sent compressed,
you must use the <literal><link linkend="prevent-compression">prevent-compression</link></literal>
action in conjunction with <literal>filter</literal>.
</para>
<para>
Content filtering can achieve some of the same effects as the
<literal><link linkend="block">block</link></literal>
action, i.e. it can be used to block ads and banners. But the mechanism
works quite differently. One effective use, is to block ad banners
based on their size (see below), since many of these seem to be somewhat
standardized.
</para>
<para>
<link linkend="contact">Feedback</link> with suggestions for new or
improved filters is particularly welcome!
</para>
<para>
The below list has only the names and a one-line description of each
predefined filter. There are <link linkend="predefined-filters">more
verbose explanations</link> of what these filters do in the <link
linkend="filter-file">filter file chapter</link>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage (with filters from the distribution <filename>default.filter</filename> file).
See <link linkend="PREDEFINED-FILTERS">the Predefined Filters section</link> for
more explanation on each:</term>
<listitem>
<para>
<anchor id="filter-js-annoyances">
<screen>+filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse.</screen>
</para>
<para>
<anchor id="filter-js-events">
<screen>+filter{js-events} # Kill all JS event bindings and timers (Radically destructive! Only for extra nasty sites).</screen>
</para>
<para>
<anchor id="filter-html-annoyances">
<screen>+filter{html-annoyances} # Get rid of particularly annoying HTML abuse.</screen>
</para>
<para>
<anchor id="filter-content-cookies">
<screen>+filter{content-cookies} # Kill cookies that come in the HTML or JS content.</screen>
</para>
<para>
<anchor id="filter-refresh-tags">
<screen>+filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups).</screen>
</para>
<para>
<anchor id="filter-unsolicited-popups">
<screen>+filter{unsolicited-popups} # Disable only unsolicited pop-up windows. Useful if your browser lacks this ability.</screen>
</para>
<para>
<anchor id="filter-all-popups">
<screen>+filter{all-popups} # Kill all popups in JavaScript and HTML. Useful if your browser lacks this ability.</screen>
</para>
<para>
<anchor id="filter-img-reorder">
<screen>+filter{img-reorder} # Reorder attributes in &lt;img&gt; tags to make the banners-by-* filters more effective.</screen>
</para>
<para>
<anchor id="filter-banners-by-size">
<screen>+filter{banners-by-size} # Kill banners by size.</screen>
</para>
<para>
<anchor id="filter-banners-by-link">
<screen>+filter{banners-by-link} # Kill banners by their links to known clicktrackers.</screen>
</para>
<para>
<anchor id="filter-webbugs">
<screen>+filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking).</screen>
</para>
<para>
<anchor id="filter-tiny-textforms">
<screen>+filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap.</screen>
</para>
<para>
<anchor id="filter-jumping-windows">
<screen>+filter{jumping-windows} # Prevent windows from resizing and moving themselves.</screen>
</para>
<para>
<anchor id="filter-frameset-borders">
<screen>+filter{frameset-borders} # Give frames a border and make them resizable.</screen>
</para>
<para>
<anchor id="filter-demoronizer">
<screen>+filter{demoronizer} # Fix MS's non-standard use of standard charsets.</screen>
</para>
<para>
<anchor id="filter-shockwave-flash">
<screen>+filter{shockwave-flash} # Kill embedded Shockwave Flash objects.</screen>
</para>
<para>
<anchor id="filter-quicktime-kioskmode">
<screen>+filter{quicktime-kioskmode} # Make Quicktime movies saveable.</screen>
</para>
<para>
<anchor id="filter-fun">
<screen>+filter{fun} # Text replacements for subversive browsing fun!</screen>
</para>
<para>
<anchor id="filter-crude-parental">
<screen>+filter{crude-parental} # Crude parental filtering. Note that this filter doesn't work reliably.</screen>
</para>
<para>
<anchor id="filter-ie-exploits">
<screen>+filter{ie-exploits} # Disable some known Internet Explorer bug exploits.</screen>
</para>
<para>
<anchor id="filter-site-specifics">
<screen>+filter{site-specifics} # Cure for site-specific problems. Don't apply generally!</screen>
</para>
<para>
<anchor id="filter-no-ping">
<screen>+filter{no-ping} # Removes non-standard ping attributes in &lt;a&gt; and &lt;area&gt; tags.</screen>
</para>
<para>
<anchor id="filter-google">
<screen>+filter{google} # CSS-based block for Google text ads. Also removes a width limitation and the toolbar advertisement.</screen>
</para>
<para>
<anchor id="filter-yahoo">
<screen>+filter{yahoo} # CSS-based block for Yahoo text ads. Also removes a width limitation.</screen>
</para>
<para>
<anchor id="filter-msn">
<screen>+filter{msn} # CSS-based block for MSN text ads. Also removes tracking URLs and a width limitation.</screen>
</para>
<para>
<anchor id="filter-blogspot">
<screen>+filter{blogspot} # Cleans up some Blogspot blogs. Read the fine print before using this.</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="force-text-mode">
<title>force-text-mode</title>
<!--
new action
-->
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Force <application>Privoxy</application> to treat a document as if it was in some kind of <emphasis>text</emphasis> format. </para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Declares a document as text, even if the <quote>Content-Type:</quote> isn't detected as such.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Boolean.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
N/A
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
As explained <literal><link linkend="filter">above</link></literal>,
<application>Privoxy</application> tries to only filter files that are
in some kind of text format. The same restrictions apply to
<literal><link linkend="content-type-overwrite">content-type-overwrite</link></literal>.
<literal>force-text-mode</literal> declares a document as text,
without looking at the <quote>Content-Type:</quote> first.
</para>
<warning>
<para>
Think twice before activating this action. Filtering binary data
with regular expressions can cause file damage.
</para>
</warning>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage:</term>
<listitem>
<para>
<screen>
+force-text-mode
</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="forward-override">
<title>forward-override</title>
<!--
new action
-->
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Change the forwarding settings based on User-Agent or request origin</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Overrules the forward directives in the configuration file.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Multi-value.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<itemizedlist>
<listitem>
<para><quote>forward .</quote> to use a direct connection without any additional proxies.</para>
</listitem>
<listitem>
<para>
<quote>forward 127.0.0.1:8123</quote> to use the HTTP proxy listening at 127.0.0.1 port 8123.
</para>
</listitem>
<listitem>
<para>
<quote>forward-socks4a 127.0.0.1:9050 .</quote> to use the socks4a proxy listening at
127.0.0.1 port 9050. Replace <quote>forward-socks4a</quote> with <quote>forward-socks4</quote>
to use a socks4 connection (with local DNS resolution) instead, use <quote>forward-socks5</quote>
for socks5 connections (with remote DNS resolution).
</para>
</listitem>
<listitem>
<para>
<quote>forward-socks4a 127.0.0.1:9050 proxy.example.org:8000</quote> to use the socks4a proxy
listening at 127.0.0.1 port 9050 to reach the HTTP proxy listening at proxy.example.org port 8000.
Replace <quote>forward-socks4a</quote> with <quote>forward-socks4</quote> to use a socks4 connection
(with local DNS resolution) instead, use <quote>forward-socks5</quote>
for socks5 connections (with remote DNS resolution).
</para>
</listitem>
</itemizedlist>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
This action takes parameters similar to the
<link linkend="forwarding">forward</link> directives in the configuration
file, but without the URL pattern. It can be used as replacement, but normally it's only
used in cases where matching based on the request URL isn't sufficient.
</para>
<warning>
<para>
Please read the description for the <link linkend="forwarding">forward</link> directives before
using this action. Forwarding to the wrong people will reduce your privacy and increase the
chances of man-in-the-middle attacks.
</para>
<para>
If the ports are missing or invalid, default values will be used. This might change
in the future and you shouldn't rely on it. Otherwise incorrect syntax causes Privoxy
to exit.
</para>
<para>
Use the <ulink url="http://config.privoxy.org/show-url-info">show-url-info CGI page</ulink>
to verify that your forward settings do what you thought the do.
</para>
</warning>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage:</term>
<listitem>
<para>
<screen>
# Always use direct connections for requests previously tagged as
# <quote>User-Agent: fetch libfetch/2.0</quote> and make sure
# resuming downloads continues to work.
# This way you can continue to use Tor for your normal browsing,
# without overloading the Tor network with your FreeBSD ports updates
# or downloads of bigger files like ISOs.
# Note that HTTP headers are easy to fake and therefore their
# values are as (un)trustworthy as your clients and users.
{+forward-override{forward .} \
-hide-if-modified-since \
-overwrite-last-modified \
}
TAG:^User-Agent: fetch libfetch/2\.0$
</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="handle-as-empty-document">
<title>handle-as-empty-document</title>
<!--
new action
-->
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Mark URLs that should be replaced by empty documents <emphasis>if they get blocked</emphasis></para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
This action alone doesn't do anything noticeable. It just marks URLs.
If the <literal><link linkend="block">block</link></literal> action <emphasis>also applies</emphasis>,
the presence or absence of this mark decides whether an HTML <quote>BLOCKED</quote>
page, or an empty document will be sent to the client as a substitute for the blocked content.
The <emphasis>empty</emphasis> document isn't literally empty, but actually contains a single space.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Boolean.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
N/A
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
Some browsers complain about syntax errors if JavaScript documents
are blocked with <application>Privoxy's</application>
default HTML page; this option can be used to silence them.
And of course this action can also be used to eliminate the &my-app;
BLOCKED message in frames.
</para>
<para>
The content type for the empty document can be specified with
<literal><link linkend="content-type-overwrite">content-type-overwrite{}</link></literal>,
but usually this isn't necessary.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage:</term>
<listitem>
<para>
<screen># Block all documents on example.org that end with ".js",
# but send an empty document instead of the usual HTML message.
{+block{Blocked JavaScript} +handle-as-empty-document}
example.org/.*\.js$
</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="handle-as-image">
<title>handle-as-image</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Mark URLs as belonging to images (so they'll be replaced by images <emphasis>if they do get blocked</emphasis>, rather than HTML pages)</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
This action alone doesn't do anything noticeable. It just marks URLs as images.
If the <literal><link linkend="block">block</link></literal> action <emphasis>also applies</emphasis>,
the presence or absence of this mark decides whether an HTML <quote>blocked</quote>
page, or a replacement image (as determined by the <literal><link
linkend="set-image-blocker">set-image-blocker</link></literal> action) will be sent to the
client as a substitute for the blocked content.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Boolean.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
N/A
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
The below generic example section is actually part of <filename>default.action</filename>.
It marks all URLs with well-known image file name extensions as images and should
be left intact.
</para>
<para>
Users will probably only want to use the handle-as-image action in conjunction with
<literal><link linkend="block">block</link></literal>, to block sources of banners, whose URLs don't
reflect the file type, like in the second example section.
</para>
<para>
Note that you cannot treat HTML pages as images in most cases. For instance, (in-line) ad
frames require an HTML page to be sent, or they won't display properly.
Forcing <literal>handle-as-image</literal> in this situation will not replace the
ad frame with an image, but lead to error messages.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage (sections):</term>
<listitem>
<para>
<screen># Generic image extensions:
#
{+handle-as-image}
/.*\.(gif|jpg|jpeg|png|bmp|ico)$
# These don't look like images, but they're banners and should be
# blocked as images:
#
{+block{Nasty banners.} +handle-as-image}
nasty-banner-server.example.com/junk.cgi\?output=trash
</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="hide-accept-language">
<title>hide-accept-language</title>
<!--
new action
-->
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Pretend to use different language settings.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Deletes or replaces the <quote>Accept-Language:</quote> HTTP header in client requests.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
Keyword: <quote>block</quote>, or any user defined value.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
Faking the browser's language settings can be useful to make a
foreign User-Agent set with
<literal><link linkend="hide-user-agent">hide-user-agent</link></literal>
more believable.
</para>
<para>
However some sites with content in different languages check the
<quote>Accept-Language:</quote> to decide which one to take by default.
Sometimes it isn't possible to later switch to another language without
changing the <quote>Accept-Language:</quote> header first.
</para>
<para>
Therefore it's a good idea to either only change the
<quote>Accept-Language:</quote> header to languages you understand,
or to languages that aren't wide spread.
</para>
<para>
Before setting the <quote>Accept-Language:</quote> header
to a rare language, you should consider that it helps to
make your requests unique and thus easier to trace.
If you don't plan to change this header frequently,
you should stick to a common language.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage (section):</term>
<listitem>
<para>
<screen># Pretend to use Canadian language settings.
{+hide-accept-language{en-ca} \
+hide-user-agent{Mozilla/5.0 (X11; U; OpenBSD i386; en-CA; rv:1.8.0.4) Gecko/20060628 Firefox/1.5.0.4} \
}
/ </screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="hide-content-disposition">
<title>hide-content-disposition</title>
<!--
new action
-->
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Prevent download menus for content you prefer to view inside the browser.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Deletes or replaces the <quote>Content-Disposition:</quote> HTTP header set by some servers.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
Keyword: <quote>block</quote>, or any user defined value.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
Some servers set the <quote>Content-Disposition:</quote> HTTP header for
documents they assume you want to save locally before viewing them.
The <quote>Content-Disposition:</quote> header contains the file name
the browser is supposed to use by default.
</para>
<para>
In most browsers that understand this header, it makes it impossible to
<emphasis>just view</emphasis> the document, without downloading it first,
even if it's just a simple text file or an image.
</para>
<para>
Removing the <quote>Content-Disposition:</quote> header helps
to prevent this annoyance, but some browsers additionally check the
<quote>Content-Type:</quote> header, before they decide if they can
display a document without saving it first. In these cases, you have
to change this header as well, before the browser stops displaying
download menus.
</para>
<para>
It is also possible to change the server's file name suggestion
to another one, but in most cases it isn't worth the time to set
it up.
</para>
<para>
This action will probably be removed in the future,
use server-header filters instead.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage:</term>
<listitem>
<para>
<screen># Disarm the download link in Sourceforge's patch tracker
{ -filter \
+content-type-overwrite{text/plain}\
+hide-content-disposition{block} }
.sourceforge.net/tracker/download\.php</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="hide-if-modified-since">
<title>hide-if-modified-since</title>
<!--
new action
-->
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Prevent yet another way to track the user's steps between sessions.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Deletes the <quote>If-Modified-Since:</quote> HTTP client header or modifies its value.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
Keyword: <quote>block</quote>, or a user defined value that specifies a range of hours.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
Removing this header is useful for filter testing, where you want to force a real
reload instead of getting status code <quote>304</quote>, which would cause the
browser to use a cached copy of the page.
</para>
<para>
Instead of removing the header, <literal>hide-if-modified-since</literal> can
also add or subtract a random amount of time to/from the header's value.
You specify a range of minutes where the random factor should be chosen from and
<application>Privoxy</application> does the rest. A negative value means
subtracting, a positive value adding.
</para>
<para>
Randomizing the value of the <quote>If-Modified-Since:</quote> makes
it less likely that the server can use the time as a cookie replacement,
but you will run into caching problems if the random range is too high.
</para>
<para>
It is a good idea to only use a small negative value and let
<literal><link linkend="overwrite-last-modified">overwrite-last-modified</link></literal>
handle the greater changes.
</para>
<para>
It is also recommended to use this action together with
<literal><link linkend="crunch-if-none-match">crunch-if-none-match</link></literal>,
otherwise it's more or less pointless.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage (section):</term>
<listitem>
<para>
<screen># Let the browser revalidate but make tracking based on the time less likely.
{+hide-if-modified-since{-60} \
+overwrite-last-modified{randomize} \
+crunch-if-none-match}
/</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="hide-from-header">
<title>hide-from-header</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Keep your (old and ill) browser from telling web servers your email address</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Deletes any existing <quote>From:</quote> HTTP header, or replaces it with the
specified string.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
Keyword: <quote>block</quote>, or any user defined value.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
The keyword <quote>block</quote> will completely remove the header
(not to be confused with the <literal><link linkend="block">block</link></literal>
action).
</para>
<para>
Alternately, you can specify any value you prefer to be sent to the web
server. If you do, it is a matter of fairness not to use any address that
is actually used by a real person.
</para>
<para>
This action is rarely needed, as modern web browsers don't send
<quote>From:</quote> headers anymore.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage:</term>
<listitem>
<para>
<screen>+hide-from-header{block}</screen> or
<screen>+hide-from-header{spam-me-senseless@sittingduck.example.com}</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="hide-referrer">
<title>hide-referrer</title>
<anchor id="hide-referer">
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Conceal which link you followed to get to a particular site</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Deletes the <quote>Referer:</quote> (sic) HTTP header from the client request,
or replaces it with a forged one.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<itemizedlist>
<listitem>
<para><quote>conditional-block</quote> to delete the header completely if the host has changed.</para>
</listitem>
<listitem>
<para><quote>conditional-forge</quote> to forge the header if the host has changed.</para>
</listitem>
<listitem>
<para><quote>block</quote> to delete the header unconditionally.</para>
</listitem>
<listitem>
<para><quote>forge</quote> to pretend to be coming from the homepage of the server we are talking to.</para>
</listitem>
<listitem>
<para>Any other string to set a user defined referrer.</para>
</listitem>
</itemizedlist>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
<literal>conditional-block</literal> is the only parameter,
that isn't easily detected in the server's log file. If it blocks the
referrer, the request will look like the visitor used a bookmark or
typed in the address directly.
</para>
<para>
Leaving the referrer unmodified for requests on the same host
allows the server owner to see the visitor's <quote>click path</quote>,
but in most cases she could also get that information by comparing
other parts of the log file: for example the User-Agent if it isn't
a very common one, or the user's IP address if it doesn't change between
different requests.
</para>
<para>
Always blocking the referrer, or using a custom one, can lead to
failures on servers that check the referrer before they answer any
requests, in an attempt to prevent their content from being
embedded or linked to elsewhere.
</para>
<para>
Both <literal>conditional-block</literal> and <literal>forge</literal>
will work with referrer checks, as long as content and valid referring page
are on the same host. Most of the time that's the case.
</para>
<para>
<literal>hide-referer</literal> is an alternate spelling of
<literal>hide-referrer</literal> and the two can be can be freely
substituted with each other. (<quote>referrer</quote> is the
correct English spelling, however the HTTP specification has a bug - it
requires it to be spelled as <quote>referer</quote>.)
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage:</term>
<listitem>
<para>
<screen>+hide-referrer{forge}</screen> or
<screen>+hide-referrer{http://www.yahoo.com/}</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="hide-user-agent">
<title>hide-user-agent</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Try to conceal your type of browser and client operating system</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Replaces the value of the <quote>User-Agent:</quote> HTTP header
in client requests with the specified value.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
Any user-defined string.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<warning>
<para>
This can lead to problems on web sites that depend on looking at this header in
order to customize their content for different browsers (which, by the
way, is <emphasis>NOT</emphasis> the right thing to do: good web sites
work browser-independently).
</para>
</warning>
<para>
Using this action in multi-user setups or wherever different types of
browsers will access the same <application>Privoxy</application> is
<emphasis>not recommended</emphasis>. In single-user, single-browser
setups, you might use it to delete your OS version information from
the headers, because it is an invitation to exploit known bugs for your
OS. It is also occasionally useful to forge this in order to access
sites that won't let you in otherwise (though there may be a good
reason in some cases). Example of this: some MSN sites will not
let <application>Mozilla</application> enter, yet forging to a
<application>Netscape 6.1</application> user-agent works just fine.
(Must be just a silly MS goof, I'm sure :-).
</para>
<para>
More information on known user-agent strings can be found at
<ulink url="http://www.user-agents.org/">http://www.user-agents.org/</ulink>
and
<ulink url="http://en.wikipedia.org/wiki/User_agent">http://en.wikipedia.org/wiki/User_agent</ulink>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage:</term>
<listitem>
<para>
<screen>+hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="limit-connect">
<title>limit-connect</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Prevent abuse of <application>Privoxy</application> as a TCP proxy relay or disable SSL for untrusted sites</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Specifies to which ports HTTP CONNECT requests are allowable.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
A comma-separated list of ports or port ranges (the latter using dashes, with the minimum
defaulting to 0 and the maximum to 65K).
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
By default, i.e. if no <literal>limit-connect</literal> action applies,
<application>Privoxy</application> allows HTTP CONNECT requests to all
ports. Use <literal>limit-connect</literal> if fine-grained control
is desired for some or all destinations.
</para>
<para>
The CONNECT methods exists in HTTP to allow access to secure websites
(<quote>https://</quote> URLs) through proxies. It works very simply:
the proxy connects to the server on the specified port, and then
short-circuits its connections to the client and to the remote server.
This means CONNECT-enabled proxies can be used as TCP relays very easily.
</para>
<para>
<application>Privoxy</application> relays HTTPS traffic without seeing
the decoded content. Websites can leverage this limitation to circumvent &my-app;'s
filters. By specifying an invalid port range you can disable HTTPS entirely.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usages:</term>
<listitem>
<!-- I had trouble getting the spacing to look right in my browser -->
<!-- I probably have the wrong font setup, bollocks. -->
<!-- Apparently the emphasis tag uses a proportional font no matter what -->
<para>
<screen>+limit-connect{443} # Port 443 is OK.
+limit-connect{80,443} # Ports 80 and 443 are OK.
+limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
+limit-connect{-} # All ports are OK
+limit-connect{,} # No HTTPS/SSL traffic is allowed</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="prevent-compression">
<title>prevent-compression</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>
Ensure that servers send the content uncompressed, so it can be
passed through <literal><link linkend="filter">filter</link></literal>s.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Removes the Accept-Encoding header which can be used to ask for compressed transfer.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Boolean.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
N/A
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
More and more websites send their content compressed by default, which
is generally a good idea and saves bandwidth. But the <literal><link
linkend="filter">filter</link></literal> and
<literal><link linkend="deanimate-gifs">deanimate-gifs</link></literal>
actions need access to the uncompressed data.
</para>
<para>
When compiled with zlib support (available since &my-app; 3.0.7), content that should be
filtered is decompressed on-the-fly and you don't have to worry about this action.
If you are using an older &my-app; version, or one that hasn't been compiled with zlib
support, this action can be used to convince the server to send the content uncompressed.
</para>
<para>
Most text-based instances compress very well, the size is seldom decreased by less than 50%,
for markup-heavy instances like news feeds saving more than 90% of the original size isn't
unusual.
</para>
<para>
Not using compression will therefore slow down the transfer, and you should only
enable this action if you really need it. As of &my-app; 3.0.7 it's disabled in all
predefined action settings.
</para>
<para>
Note that some (rare) ill-configured sites don't handle requests for uncompressed
documents correctly. Broken PHP applications tend to send an empty document body,
some IIS versions only send the beginning of the content. If you enable
<literal>prevent-compression</literal> per default, you might want to add
exceptions for those sites. See the example for how to do that.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage (sections):</term>
<listitem>
<para>
<screen>
# Selectively turn off compression, and enable a filter
#
{ +filter{tiny-textforms} +prevent-compression }
# Match only these sites
.google.
sourceforge.net
sf.net
# Or instead, we could set a universal default:
#
{ +prevent-compression }
/ # Match all sites
# Then maybe make exceptions for broken sites:
#
{ -prevent-compression }
.compusa.com/</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="overwrite-last-modified">
<title>overwrite-last-modified</title>
<!--
new action
-->
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Prevent yet another way to track the user's steps between sessions.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Deletes the <quote>Last-Modified:</quote> HTTP server header or modifies its value.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
One of the keywords: <quote>block</quote>, <quote>reset-to-request-time</quote>
and <quote>randomize</quote>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
Removing the <quote>Last-Modified:</quote> header is useful for filter
testing, where you want to force a real reload instead of getting status
code <quote>304</quote>, which would cause the browser to reuse the old
version of the page.
</para>
<para>
The <quote>randomize</quote> option overwrites the value of the
<quote>Last-Modified:</quote> header with a randomly chosen time
between the original value and the current time. In theory the server
could send each document with a different <quote>Last-Modified:</quote>
header to track visits without using cookies. <quote>Randomize</quote>
makes it impossible and the browser can still revalidate cached documents.
</para>
<para>
<quote>reset-to-request-time</quote> overwrites the value of the
<quote>Last-Modified:</quote> header with the current time. You could use
this option together with
<literal><link linkend="hide-if-modified-since">hide-if-modified-since</link></literal>
to further customize your random range.
</para>
<para>
The preferred parameter here is <quote>randomize</quote>. It is safe
to use, as long as the time settings are more or less correct.
If the server sets the <quote>Last-Modified:</quote> header to the time
of the request, the random range becomes zero and the value stays the same.
Therefore you should later randomize it a second time with
<literal><link linkend="hide-if-modified-since">hided-if-modified-since</link></literal>,
just to be sure.
</para>
<para>
It is also recommended to use this action together with
<literal><link linkend="crunch-if-none-match">crunch-if-none-match</link></literal>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage:</term>
<listitem>
<para>
<screen># Let the browser revalidate without being tracked across sessions
{ +hide-if-modified-since{-60} \
+overwrite-last-modified{randomize} \
+crunch-if-none-match}
/</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="redirect">
<title>redirect</title>
<!--
new action
-->
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>
Redirect requests to other sites.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Convinces the browser that the requested document has been moved
to another location and the browser should get it from there.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Parameterized</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
An absolute URL or a single pcrs command.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
Requests to which this action applies are answered with a
HTTP redirect to URLs of your choosing. The new URL is
either provided as parameter, or derived by applying a
single pcrs command to the original URL.
</para>
<para>
This action will be ignored if you use it together with
<literal><link linkend="block">block</link></literal>.
It can be combined with
<literal><link linkend="fast-redirects">fast-redirects{check-decoded-url}</link></literal>
to redirect to a decoded version of a rewritten URL.
</para>
<para>
Use this action carefully, make sure not to create redirection loops
and be aware that using your own redirects might make it
possible to fingerprint your requests.
</para>
<para>
In case of problems with your redirects, or simply to watch
them working, enable <link linkend="DEBUG">debug 128</link>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usages:</term>
<listitem>
<para>
<screen># Replace example.com's style sheet with another one
{ +redirect{http://localhost/css-replacements/example.com.css} }
example.com/stylesheet\.css
# Create a short, easy to remember nickname for a favorite site
# (relies on the browser accept and forward invalid URLs to &my-app;)
{ +redirect{http://www.privoxy.org/user-manual/actions-file.html} }
a
# Always use the expanded view for Undeadly.org articles
# (Note the $ at the end of the URL pattern to make sure
# the request for the rewritten URL isn't redirected as well)
{+redirect{s@$@&amp;mode=expanded@}}
undeadly.org/cgi\?action=article&amp;sid=\d*$
# Redirect Google search requests to MSN
{+redirect{s@^http://[^/]*/search\?q=([^&amp;]*).*@http://search.msn.com/results.aspx?q=$1@}}
.google.com/search
# Redirect MSN search requests to Yahoo
{+redirect{s@^http://[^/]*/results\.aspx\?q=([^&amp;]*).*@http://search.yahoo.com/search?p=$1@}}
search.msn.com//results\.aspx\?q=
# Redirect remote requests for this manual
# to the local version delivered by Privoxy
{+redirect{s@^http://www@http://config@}}
www.privoxy.org/user-manual/</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="server-header-filter">
<title>server-header-filter</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>
Rewrite or remove single server headers.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
All server headers to which this action applies are filtered on-the-fly
through the specified regular expression based substitutions.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- boolean, parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
The name of a server-header filter, as defined in one of the
<link linkend="filter-file">filter files</link>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
Server-header filters are applied to each header on its own, not to
all at once. This makes it easier to diagnose problems, but on the downside
you can't write filters that only change header x if header y's value is z.
You can do that by using tags though.
</para>
<para>
Server-header filters are executed after the other header actions have finished
and use their output as input.
</para>
<para>
Please refer to the <link linkend="filter-file">filter file chapter</link>
to learn which server-header filters are available by default, and how to
create your own.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage (section):</term>
<listitem>
<para>
<screen>
{+server-header-filter{html-to-xml}}
example.org/xml-instance-that-is-delivered-as-html
{+server-header-filter{xml-to-html}}
example.org/instance-that-is-delivered-as-xml-but-is-not
</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="server-header-tagger">
<title>server-header-tagger</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>
Enable or disable filters based on the Content-Type header.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Server headers to which this action applies are filtered on-the-fly through
the specified regular expression based substitutions, the result is used as
tag.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- boolean, parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
The name of a server-header tagger, as defined in one of the
<link linkend="filter-file">filter files</link>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
Server-header taggers are applied to each header on its own,
and as the header isn't modified, each tagger <quote>sees</quote>
the original.
</para>
<para>
Server-header taggers are executed before all other header actions
that modify server headers. Their tags can be used to control
all of the other server-header actions, the content filters
and the crunch actions (<link linkend="redirect">redirect</link>
and <link linkend="block">block</link>).
</para>
<para>
Obviously crunching based on tags created by server-header taggers
doesn't prevent the request from showing up in the server's log file.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage (section):</term>
<listitem>
<para>
<screen>
# Tag every request with the content type declared by the server
{+server-header-tagger{content-type}}
/
</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="session-cookies-only">
<title>session-cookies-only</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>
Allow only temporary <quote>session</quote> cookies (for the current
browser session <emphasis>only</emphasis>).
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
Deletes the <quote>expires</quote> field from <quote>Set-Cookie:</quote>
server headers. Most browsers will not store such cookies permanently and
forget them in between sessions.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Boolean.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<para>
N/A
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
This is less strict than <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal> /
<literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal> and allows you to browse
websites that insist or rely on setting cookies, without compromising your privacy too badly.
</para>
<para>
Most browsers will not permanently store cookies that have been processed by
<literal>session-cookies-only</literal> and will forget about them between sessions.
This makes profiling cookies useless, but won't break sites which require cookies so
that you can log in for transactions. This is generally turned on for all
sites, and is the recommended setting.
</para>
<para>
It makes <emphasis>no sense at all</emphasis> to use <literal>session-cookies-only</literal>
together with <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal> or
<literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal>. If you do, cookies
will be plainly killed.
</para>
<para>
Note that it is up to the browser how it handles such cookies without an <quote>expires</quote>
field. If you use an exotic browser, you might want to try it out to be sure.
</para>
<para>
This setting also has no effect on cookies that may have been stored
previously by the browser before starting <application>Privoxy</application>.
These would have to be removed manually.
</para>
<para>
<application>Privoxy</application> also uses
the <link linkend="filter-content-cookies">content-cookies filter</link>
to block some types of cookies. Content cookies are not effected by
<literal>session-cookies-only</literal>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage:</term>
<listitem>
<para>
<screen>+session-cookies-only</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3 renderas="sect4" id="set-image-blocker">
<title>set-image-blocker</title>
<variablelist>
<varlistentry>
<term>Typical use:</term>
<listitem>
<para>Choose the replacement for blocked images</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Effect:</term>
<listitem>
<para>
This action alone doesn't do anything noticeable. If <emphasis>both</emphasis>
<literal><link linkend="block">block</link></literal> <emphasis>and</emphasis> <literal><link
linkend="handle-as-image">handle-as-image</link></literal> <emphasis>also</emphasis>
apply, i.e. if the request is to be blocked as an image,
<emphasis>then</emphasis> the parameter of this action decides what will be
sent as a replacement.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Type:</term>
<!-- Boolean, Parameterized, Multi-value -->
<listitem>
<para>Parameterized.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Parameter:</term>
<listitem>
<itemizedlist>
<listitem>
<para>
<quote>pattern</quote> to send a built-in checkerboard pattern image. The image is visually
decent, scales very well, and makes it obvious where banners were busted.
</para>
</listitem>
<listitem>
<para>
<quote>blank</quote> to send a built-in transparent image. This makes banners disappear
completely, but makes it hard to detect where <application>Privoxy</application> has blocked
images on a given page and complicates troubleshooting if <application>Privoxy</application>
has blocked innocent images, like navigation icons.
</para>
</listitem>
<listitem>
<para>
<quote><replaceable class="parameter">target-url</replaceable></quote> to
send a redirect to <replaceable class="parameter">target-url</replaceable>. You can redirect
to any image anywhere, even in your local filesystem via <quote>file:///</quote> URL.
(But note that not all browsers support redirecting to a local file system).
</para>
<para>
A good application of redirects is to use special <application>Privoxy</application>-built-in
URLs, which send the built-in images, as <replaceable class="parameter">target-url</replaceable>.
This has the same visual effect as specifying <quote>blank</quote> or <quote>pattern</quote> in
the first place, but enables your browser to cache the replacement image, instead of requesting
it over and over again.
</para>
</listitem>
</itemizedlist>
</listitem>
</varlistentry>
<varlistentry>
<term>Notes:</term>
<listitem>
<para>
The URLs for the built-in images are <quote>http://config.privoxy.org/send-banner?type=<replaceable
class="parameter">type</replaceable></quote>, where <replaceable class="parameter">type</replaceable> is
either <quote>blank</quote> or <quote>pattern</quote>.
</para>
<para>
There is a third (advanced) type, called <quote>auto</quote>. It is <emphasis>NOT</emphasis> to be
used in <literal>set-image-blocker</literal>, but meant for use from <link linkend="filter-file">filters</link>.
Auto will select the type of image that would have applied to the referring page, had it been an image.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>Example usage:</term>
<listitem>
<para>
Built-in pattern:
</para>
<para>
<screen>+set-image-blocker{pattern}</screen>
</para>
<para>
Redirect to the BSD daemon:
</para>
<para>
<screen>+set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}</screen>
</para>
<para>
Redirect to the built-in pattern for better caching:
</para>
<para>
<screen>+set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}</screen>
</para>
</listitem>
</varlistentry>
</variablelist>
</sect3>
<!-- ~~~~~ New section ~~~~~ -->
<sect3>
<title>Summary</title>
<para>
Note that many of these actions have the potential to cause a page to
misbehave, possibly even not to display at all. There are many ways
a site designer may choose to design his site, and what HTTP header
content, and other criteria, he may depend on. There is no way to have hard
and fast rules for all sites. See the <link
linkend="ACTIONSANAT">Appendix</link> for a brief example on troubleshooting
actions.
</para>
</sect3>
</sect2>
<!-- ~~~~~ New section ~~~~~ -->
<sect2 id="aliases">
<title>Aliases</title>
<para>
Custom <quote>actions</quote>, known to <application>Privoxy</application>
as <quote>aliases</quote>, can be defined by combining other actions.
These can in turn be invoked just like the built-in actions.
Currently, an alias name can contain any character except space, tab,
<quote>=</quote>,
<quote>{</quote> and <quote>}</quote>, but we <emphasis>strongly
recommend</emphasis> that you only use <quote>a</quote> to <quote>z</quote>,
<quote>0</quote> to <quote>9</quote>, <quote>+</quote>, and <quote>-</quote>.
Alias names are not case sensitive, and are not required to start with a
<quote>+</quote> or <quote>-</quote> sign, since they are merely textually
expanded.
</para>
<para>
Aliases can be used throughout the actions file, but they <emphasis>must be
defined in a special section at the top of the file!</emphasis>
And there can only be one such section per actions file. Each actions file may
have its own alias section, and the aliases defined in it are only visible
within that file.
</para>
<para>
There are two main reasons to use aliases: One is to save typing for frequently
used combinations of actions, the other one is a gain in flexibility: If you
decide once how you want to handle shops by defining an alias called
<quote>shop</quote>, you can later change your policy on shops in
<emphasis>one</emphasis> place, and your changes will take effect everywhere
in the actions file where the <quote>shop</quote> alias is used. Calling aliases
by their purpose also makes your actions files more readable.
</para>
<para>
Currently, there is one big drawback to using aliases, though:
<application>Privoxy</application>'s built-in web-based action file
editor honors aliases when reading the actions files, but it expands
them before writing. So the effects of your aliases are of course preserved,
but the aliases themselves are lost when you edit sections that use aliases
with it.
</para>
<para>
Now let's define some aliases...
</para>
<para>
<screen>
# Useful custom aliases we can use later.
#
# Note the (required!) section header line and that this section
# must be at the top of the actions file!
#
{{alias}}
# These aliases just save typing later:
# (Note that some already use other aliases!)
#
+crunch-all-cookies = +<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> +<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
-crunch-all-cookies = -<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> -<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
+block-as-image = +block{Blocked image.} +handle-as-image
allow-all-cookies = -crunch-all-cookies -<link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> -<link linkend="FILTER-CONTENT-COOKIES">filter{content-cookies}</link>
# These aliases define combinations of actions
# that are useful for certain types of sites:
#
fragile = -<link linkend="BLOCK">block</link> -<link linkend="FILTER">filter</link> -crunch-all-cookies -<link linkend="FAST-REDIRECTS">fast-redirects</link> -<link linkend="HIDE-REFERER">hide-referrer</link> -<link linkend="PREVENT-COMPRESSION">prevent-compression</link>
shop = -crunch-all-cookies -<link linkend="FILTER-ALL-POPUPS">filter{all-popups}</link>
# Short names for other aliases, for really lazy people ;-)
#
c0 = +crunch-all-cookies
c1 = -crunch-all-cookies</screen>
</para>
<para>
...and put them to use. These sections would appear in the lower part of an
actions file and define exceptions to the default actions (as specified further
up for the <quote>/</quote> pattern):
</para>
<para>
<screen>
# These sites are either very complex or very keen on
# user data and require minimal interference to work:
#
{fragile}
.office.microsoft.com
.windowsupdate.microsoft.com
# Gmail is really mail.google.com, not gmail.com
mail.google.com
# Shopping sites:
# Allow cookies (for setting and retrieving your customer data)
#
{shop}
.quietpc.com
.worldpay.com # for quietpc.com
mybank.example.com
# These shops require pop-ups:
#
{-filter{all-popups} -filter{unsolicited-popups}}
.dabs.com
.overclockers.co.uk</screen>
</para>
<para>
Aliases like <quote>shop</quote> and <quote>fragile</quote> are typically used for
<quote>problem</quote> sites that require more than one action to be disabled
in order to function properly.
</para>
</sect2>
<!--
hal stop here
-->
<!-- ~~~~~ New section ~~~~~ -->
<sect2 id="act-examples">
<title>Actions Files Tutorial</title>
<para>
The above chapters have shown <link linkend="actions-file">which actions files
there are and how they are organized</link>, how actions are <link
linkend="actions">specified</link> and <link linkend="actions-apply">applied
to URLs</link>, how <link linkend="af-patterns">patterns</link> work, and how to
define and use <link linkend="aliases">aliases</link>. Now, let's look at an
example <filename>match-all.action</filename>, <filename>default.action</filename>
and <filename>user.action</filename> file and see how all these pieces come together:
</para>
<sect3>
<title>match-all.action</title>
<para>
Remember <emphasis>all actions are disabled when matching starts</emphasis>,
so we have to explicitly enable the ones we want.
</para>
<para>
While the <filename>match-all.action</filename> file only contains a
single section, it is probably the most important one. It has only one
pattern, <quote><literal>/</literal></quote>, but this pattern
<link linkend="af-patterns">matches all URLs</link>. Therefore, the set of
actions used in this <quote>default</quote> section <emphasis>will
be applied to all requests as a start</emphasis>. It can be partly or
wholly overridden by other actions files like <filename>default.action</filename>
and <filename>user.action</filename>, but it will still be largely responsible
for your overall browsing experience.
</para>
<para>
Again, at the start of matching, all actions are disabled, so there is
no need to disable any actions here. (Remember: a <quote>+</quote>
preceding the action name enables the action, a <quote>-</quote> disables!).
Also note how this long line has been made more readable by splitting it into
multiple lines with line continuation.
</para>
<para>
<screen>
{ \
+<link linkend="CHANGE-X-FORWARDED-FOR">change-x-forwarded-for{block}</link> \
+<link linkend="HIDE-FROM-HEADER">hide-from-header{block}</link> \
+<link linkend="SET-IMAGE-BLOCKER">set-image-blocker{pattern}</link> \
}
/ # Match all URLs
</screen>
</para>
<para>
The default behavior is now set.
</para>
</sect3>
<sect3>
<title>default.action</title>
<para>
If you aren't a developer, there's no need for you to edit the
<filename>default.action</filename> file. It is maintained by
the &my-app; developers and if you disagree with some of the
sections, you should overrule them in your <filename>user.action</filename>.
</para>
<para>
Understanding the <filename>default.action</filename> file can
help you with your <filename>user.action</filename>, though.
</para>
<para>
The first section in this file is a special section for internal use
that prevents older &my-app; versions from reading the file:
</para>
<para>
<screen>
##########################################################################
# Settings -- Don't change! For internal Privoxy use ONLY.
##########################################################################
{{settings}}
for-privoxy-version=3.0.11</screen>
</para>
<para>
After that comes the (optional) alias section. We'll use the example
section from the above <link linkend="aliases">chapter on aliases</link>,
that also explains why and how aliases are used:
</para>
<para>
<screen>
##########################################################################
# Aliases
##########################################################################
{{alias}}
# These aliases just save typing later:
# (Note that some already use other aliases!)
#
+crunch-all-cookies = +<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> +<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
-crunch-all-cookies = -<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> -<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
+block-as-image = +block{Blocked image.} +handle-as-image
mercy-for-cookies = -crunch-all-cookies -<link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> -<link linkend="FILTER-CONTENT-COOKIES">filter{content-cookies}</link>
# These aliases define combinations of actions
# that are useful for certain types of sites:
#
fragile = -<link linkend="BLOCK">block</link> -<link linkend="FILTER">filter</link> -crunch-all-cookies -<link linkend="FAST-REDIRECTS">fast-redirects</link> -<link linkend="HIDE-REFERER">hide-referrer</link>
shop = -crunch-all-cookies -<link linkend="FILTER-ALL-POPUPS">filter{all-popups}</link></screen>
</para>
<para>
The first of our specialized sections is concerned with <quote>fragile</quote>
sites, i.e. sites that require minimum interference, because they are either
very complex or very keen on tracking you (and have mechanisms in place that
make them unusable for people who avoid being tracked). We will simply use
our pre-defined <literal>fragile</literal> alias instead of stating the list
of actions explicitly:
</para>
<para>
<screen>
##########################################################################
# Exceptions for sites that'll break under the default action set:
##########################################################################
# "Fragile" Use a minimum set of actions for these sites (see alias above):
#
{ fragile }
.office.microsoft.com # surprise, surprise!
.windowsupdate.microsoft.com
mail.google.com</screen>
</para>
<para>
Shopping sites are not as fragile, but they typically
require cookies to log in, and pop-up windows for shopping
carts or item details. Again, we'll use a pre-defined alias:
</para>
<para>
<screen>
# Shopping sites:
#
{ shop }
.quietpc.com
.worldpay.com # for quietpc.com
.jungle.com
.scan.co.uk</screen>
</para>
<para>
The <literal><link linkend="FAST-REDIRECTS">fast-redirects</link></literal>
action, which may have been enabled in <filename>match-all.action</filename>,
breaks some sites. So disable it for popular sites where we know it misbehaves:
</para>
<para>
<screen>
{ -<link linkend="FAST-REDIRECTS">fast-redirects</link> }
login.yahoo.com
edit.*.yahoo.com
.google.com
.altavista.com/.*(like|url|link):http
.altavista.com/trans.*urltext=http
.nytimes.com</screen>
</para>
<para>
It is important that <application>Privoxy</application> knows which
URLs belong to images, so that <emphasis>if</emphasis> they are to
be blocked, a substitute image can be sent, rather than an HTML page.
Contacting the remote site to find out is not an option, since it
would destroy the loading time advantage of banner blocking, and it
would feed the advertisers information about you. We can mark any
URL as an image with the <literal><link
linkend="handle-as-image">handle-as-image</link></literal> action,
and marking all URLs that end in a known image file extension is a
good start:
</para>
<para>
<screen>
##########################################################################
# Images:
##########################################################################
# Define which file types will be treated as images, in case they get
# blocked further down this file:
#
{ +<link linkend="HANDLE-AS-IMAGE">handle-as-image</link> }
/.*\.(gif|jpe?g|png|bmp|ico)$</screen>
</para>
<para>
And then there are known banner sources. They often use scripts to
generate the banners, so it won't be visible from the URL that the
request is for an image. Hence we block them <emphasis>and</emphasis>
mark them as images in one go, with the help of our
<literal>+block-as-image</literal> alias defined above. (We could of
course just as well use <literal>+<link linkend="block">block</link>
+<link linkend="handle-as-image">handle-as-image</link></literal> here.)
Remember that the type of the replacement image is chosen by the
<literal><link linkend="set-image-blocker">set-image-blocker</link></literal>
action. Since all URLs have matched the default section with its
<literal>+<link linkend="set-image-blocker">set-image-blocker</link>{pattern}</literal>
action before, it still applies and needn't be repeated:
</para>
<para>
<screen>
# Known ad generators:
#
{ +block-as-image }
ar.atwola.com
.ad.doubleclick.net
.ad.*.doubleclick.net
.a.yimg.com/(?:(?!/i/).)*$
.a[0-9].yimg.com/(?:(?!/i/).)*$
bs*.gsanet.com
.qkimg.net</screen>
</para>
<para>
One of the most important jobs of <application>Privoxy</application>
is to block banners. Many of these can be <quote>blocked</quote>
by the <literal><link linkend="filter">filter</link>{banners-by-size}</literal>
action, which we enabled above, and which deletes the references to banner
images from the pages while they are loaded, so the browser doesn't request
them anymore, and hence they don't need to be blocked here. But this naturally
doesn't catch all banners, and some people choose not to use filters, so we
need a comprehensive list of patterns for banner URLs here, and apply the
<literal><link linkend="block">block</link></literal> action to them.
</para>
<para>
First comes many generic patterns, which do most of the work, by
matching typical domain and path name components of banners. Then comes
a list of individual patterns for specific sites, which is omitted here
to keep the example short:
</para>
<para>
<screen>
##########################################################################
# Block these fine banners:
##########################################################################
{ <link linkend="BLOCK">+block{Banner ads.}</link> }
# Generic patterns:
#
ad*.
.*ads.
banner?.
count*.
/.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
/(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
# Site-specific patterns (abbreviated):
#
.hitbox.com</screen>
</para>
<para>
It's quite remarkable how many advertisers actually call their banner
servers ads.<replaceable>company</replaceable>.com, or call the directory
in which the banners are stored simply <quote>banners</quote>. So the above
generic patterns are surprisingly effective.
</para>
<para>
But being very generic, they necessarily also catch URLs that we don't want
to block. The pattern <literal>.*ads.</literal> e.g. catches
<quote>nasty-<emphasis>ads</emphasis>.nasty-corp.com</quote> as intended,
but also <quote>downlo<emphasis>ads</emphasis>.sourcefroge.net</quote> or
<quote><emphasis>ads</emphasis>l.some-provider.net.</quote> So here come some
well-known exceptions to the <literal>+<link linkend="BLOCK">block</link></literal>
section above.
</para>
<para>
Note that these are exceptions to exceptions from the default! Consider the URL
<quote>downloads.sourcefroge.net</quote>: Initially, all actions are deactivated,
so it wouldn't get blocked. Then comes the defaults section, which matches the
URL, but just deactivates the <literal><link linkend="BLOCK">block</link></literal>
action once again. Then it matches <literal>.*ads.</literal>, an exception to the
general non-blocking policy, and suddenly
<literal><link linkend="BLOCK">+block</link></literal> applies. And now, it'll match
<literal>.*loads.</literal>, where <literal><link linkend="BLOCK">-block</link></literal>
applies, so (unless it matches <emphasis>again</emphasis> further down) it ends up
with no <literal><link linkend="BLOCK">block</link></literal> action applying.
</para>
<para>
<screen>
##########################################################################
# Save some innocent victims of the above generic block patterns:
##########################################################################
# By domain:
#
{ -<link linkend="BLOCK">block</link> }
adv[io]*. # (for advogato.org and advice.*)
adsl. # (has nothing to do with ads)
adobe. # (has nothing to do with ads either)
ad[ud]*. # (adult.* and add.*)
.edu # (universities don't host banners (yet!))
.*loads. # (downloads, uploads etc)
# By path:
#
/.*loads/
# Site-specific:
#
www.globalintersec.com/adv # (adv = advanced)
www.ugu.com/sui/ugu/adv</screen>
</para>
<para>
Filtering source code can have nasty side effects,
so make an exception for our friends at sourceforge.net,
and all paths with <quote>cvs</quote> in them. Note that
<literal>-<link linkend="FILTER">filter</link></literal>
disables <emphasis>all</emphasis> filters in one fell swoop!
</para>
<para>
<screen>
# Don't filter code!
#
{ -<link linkend="FILTER">filter</link> }
/(.*/)?cvs
bugzilla.
developer.
wiki.
.sourceforge.net</screen>
</para>
<para>
The actual <filename>default.action</filename> is of course much more
comprehensive, but we hope this example made clear how it works.
</para>
</sect3>
<sect3><title>user.action</title>
<para>
So far we are painting with a broad brush by setting general policies,
which would be a reasonable starting point for many people. Now,
you might want to be more specific and have customized rules that
are more suitable to your personal habits and preferences. These would
be for narrowly defined situations like your ISP or your bank, and should
be placed in <filename>user.action</filename>, which is parsed after all other
actions files and hence has the last word, over-riding any previously
defined actions. <filename>user.action</filename> is also a
<emphasis>safe</emphasis> place for your personal settings, since
<filename>default.action</filename> is actively maintained by the
<application>Privoxy</application> developers and you'll probably want
to install updated versions from time to time.
</para>
<para>
So let's look at a few examples of things that one might typically do in
<filename>user.action</filename>:
</para>
<!-- brief sample user.action here -->
<para>
<screen>
# My user.action file. &lt;fred@example.com&gt;</screen>
</para>
<para>
As <link linkend="aliases">aliases</link> are local to the actions
file that they are defined in, you can't use the ones from
<filename>default.action</filename>, unless you repeat them here:
</para>
<para>
<screen>
# Aliases are local to the file they are defined in.
# (Re-)define aliases for this file:
#
{{alias}}
#
# These aliases just save typing later, and the alias names should
# be self explanatory.
#
+crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
-crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
allow-all-cookies = -crunch-all-cookies -session-cookies-only
allow-popups = -filter{all-popups}
+block-as-image = +block{Blocked as image.} +handle-as-image
-block-as-image = -block
# These aliases define combinations of actions that are useful for
# certain types of sites:
#
fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referrer
shop = -crunch-all-cookies allow-popups
# Allow ads for selected useful free sites:
#
allow-ads = -block -filter{banners-by-size} -filter{banners-by-link}
# Alias for specific file types that are text, but might have conflicting
# MIME types. We want the browser to force these to be text documents.
handle-as-text = -<link linkend="FILTER">filter</link> +-<link linkend="content-type-overwrite">content-type-overwrite{text/plain}</link> +-<link linkend="FORCE-TEXT-MODE">force-text-mode</link> -<link linkend="HIDE-CONTENT-DISPOSITION">hide-content-disposition</link></screen>
</para>
<para>
Say you have accounts on some sites that you visit regularly, and
you don't want to have to log in manually each time. So you'd like
to allow persistent cookies for these sites. The
<literal>allow-all-cookies</literal> alias defined above does exactly
that, i.e. it disables crunching of cookies in any direction, and the
processing of cookies to make them only temporary.
</para>
<para>
<screen>
{ allow-all-cookies }
sourceforge.net
.yahoo.com
.msdn.microsoft.com
.redhat.com</screen>
</para>
<para>
Your bank is allergic to some filter, but you don't know which, so you disable them all:
</para>
<para>
<screen>
{ -<link linkend="FILTER">filter</link> }
.your-home-banking-site.com</screen>
</para>
<para>
Some file types you may not want to filter for various reasons:
</para>
<para>
<screen>
# Technical documentation is likely to contain strings that might
# erroneously get altered by the JavaScript-oriented filters:
#
.tldp.org
/(.*/)?selfhtml/
# And this stupid host sends streaming video with a wrong MIME type,
# so that Privoxy thinks it is getting HTML and starts filtering:
#
stupid-server.example.com/</screen>
</para>
<para>
Example of a simple <link linkend="BLOCK">block</link> action. Say you've
seen an ad on your favourite page on example.com that you want to get rid of.
You have right-clicked the image, selected <quote>copy image location</quote>
and pasted the URL below while removing the leading http://, into a
<literal>{ +block{} }</literal> section. Note that <literal>{ +handle-as-image
}</literal> need not be specified, since all URLs ending in
<literal>.gif</literal> will be tagged as images by the general rules as set
in default.action anyway:
</para>
<para>
<screen>
{ +<link linkend="BLOCK">block</link>{Nasty ads.} }
www.example.com/nasty-ads/sponsor\.gif
another.example.net/more/junk/here/</screen>
</para>
<para>
The URLs of dynamically generated banners, especially from large banner
farms, often don't use the well-known image file name extensions, which
makes it impossible for <application>Privoxy</application> to guess
the file type just by looking at the URL.
You can use the <literal>+block-as-image</literal> alias defined above for
these cases.
Note that objects which match this rule but then turn out NOT to be an
image are typically rendered as a <quote>broken image</quote> icon by the
browser. Use cautiously.
</para>
<para>
<screen>
{ +block-as-image }
.doubleclick.net
.fastclick.net
/Realmedia/ads/
ar.atwola.com/</screen>
</para>
<para>
Now you noticed that the default configuration breaks Forbes Magazine,
but you were too lazy to find out which action is the culprit, and you
were again too lazy to give <link linkend="contact">feedback</link>, so
you just used the <literal>fragile</literal> alias on the site, and
-- <emphasis>whoa!</emphasis> -- it worked. The <literal>fragile</literal>
aliases disables those actions that are most likely to break a site. Also,
good for testing purposes to see if it is <application>Privoxy</application>
that is causing the problem or not. We later find other regular sites
that misbehave, and add those to our personalized list of troublemakers:
</para>
<para>
<screen>
{ fragile }
.forbes.com
webmail.example.com
.mybank.com</screen>
</para>
<para>
You like the <quote>fun</quote> text replacements in <filename>default.filter</filename>,
but it is disabled in the distributed actions file.
So you'd like to turn it on in your private,
update-safe config, once and for all:
</para>
<para>
<screen>
{ +<link linkend="filter-fun">filter{fun}</link> }
/ # For ALL sites!</screen>
</para>
<para>
Note that the above is not really a good idea: There are exceptions
to the filters in <filename>default.action</filename> for things that
really shouldn't be filtered, like code on CVS->Web interfaces. Since
<filename>user.action</filename> has the last word, these exceptions
won't be valid for the <quote>fun</quote> filtering specified here.
</para>
<para>
You might also worry about how your favourite free websites are
funded, and find that they rely on displaying banner advertisements
to survive. So you might want to specifically allow banners for those
sites that you feel provide value to you:
</para>
<para>
<screen>
{ allow-ads }
.sourceforge.net
.slashdot.org
.osdn.net</screen>
</para>
<para>
Note that <literal>allow-ads</literal> has been aliased to
<literal>-<link linkend="block">block</link></literal>,
<literal>-<link linkend="filter-banners-by-size">filter{banners-by-size}</link></literal>, and
<literal>-<link linkend="filter-banners-by-link">filter{banners-by-link}</link></literal> above.
</para>
<para>
Invoke another alias here to force an over-ride of the MIME type <literal>
application/x-sh</literal> which typically would open a download type
dialog. In my case, I want to look at the shell script, and then I can save
it should I choose to.
</para>
<para>
<screen>
{ handle-as-text }
/.*\.sh$</screen>
</para>
<para>
<filename>user.action</filename> is generally the best place to define
exceptions and additions to the default policies of
<filename>default.action</filename>. Some actions are safe to have their
default policies set here though. So let's set a default policy to have a
<quote>blank</quote> image as opposed to the checkerboard pattern for
<emphasis>ALL</emphasis> sites. <quote>/</quote> of course matches all URL
paths and patterns:
</para>
<para>
<screen>
{ +<link linkend="set-image-blocker">set-image-blocker{blank}</link> }
/ # ALL sites</screen>
</para>
</sect3>
</sect2>
<!-- ~ End section ~ -->
</sect1>
<!-- ~ End section ~ -->
<!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
<sect1 id="filter-file">
<title>Filter Files</title>
<para>
On-the-fly text substitutions need
to be defined in a <quote>filter file</quote>. Once defined, they
can then be invoked as an <quote>action</quote>.
</para>
<para>
&my-app; supports three different filter actions:
<literal><link linkend="filter">filter</link></literal> to
rewrite the content that is send to the client,
<literal><link linkend="client-header-filter">client-header-filter</link></literal>
to rewrite headers that are send by the client, and
<literal><link linkend="server-header-filter">server-header-filter</link></literal>
to rewrite headers that are send by the server.
</para>
<para>
&my-app; also supports two tagger actions:
<literal><link linkend="client-header-tagger">client-header-tagger</link></literal>
and
<literal><link linkend="server-header-tagger">server-header-tagger</link></literal>.
Taggers and filters use the same syntax in the filter files, the difference
is that taggers don't modify the text they are filtering, but use a rewritten
version of the filtered text as tag. The tags can then be used to change the
applying actions through sections with <link linkend="tag-pattern">tag-patterns</link>.
</para>
<para>
Multiple filter files can be defined through the <literal> <link
linkend="filterfile">filterfile</link></literal> config directive. The filters
as supplied by the developers are located in
<filename>default.filter</filename>. It is recommended that any locally
defined or modified filters go in a separately defined file such as
<filename>user.filter</filename>.
</para>
<para>
Common tasks for content filters are to eliminate common annoyances in
HTML and JavaScript, such as pop-up windows,
exit consoles, crippled windows without navigation tools, the
infamous &lt;BLINK&gt; tag etc, to suppress images with certain
width and height attributes (standard banner sizes or web-bugs),
or just to have fun.
</para>
<para>
Enabled content filters are applied to any content whose
<quote>Content Type</quote> header is recognised as a sign
of text-based content, with the exception of <literal>text/plain</literal>.
Use the <link linkend="FORCE-TEXT-MODE">force-text-mode</link> action
to also filter other content.
</para>
<para>
Substitutions are made at the source level, so if you want to <quote>roll
your own</quote> filters, you should first be familiar with HTML syntax,
and, of course, regular expressions.
</para>
<para>
Just like the <link linkend="actions-file">actions files</link>, the
filter file is organized in sections, which are called <emphasis>filters</emphasis>
here. Each filter consists of a heading line, that starts with one of the
<emphasis>keywords</emphasis> <literal>FILTER:</literal>,
<literal>CLIENT-HEADER-FILTER:</literal> or <literal>SERVER-HEADER-FILTER:</literal>
followed by the filter's <emphasis>name</emphasis>, and a short (one line)
<emphasis>description</emphasis> of what it does. Below that line
come the <emphasis>jobs</emphasis>, i.e. lines that define the actual
text substitutions. By convention, the name of a filter
should describe what the filter <emphasis>eliminates</emphasis>. The
comment is used in the <ulink url="http://config.privoxy.org/">web-based
user interface</ulink>.
</para>
<para>
Once a filter called <replaceable>name</replaceable> has been defined
in the filter file, it can be invoked by using an action of the form
+<literal><link linkend="filter">filter</link>{<replaceable>name</replaceable>}</literal>
in any <link linkend="actions-file">actions file</link>.
</para>
<para>
Filter definitions start with a header line that contains the filter
type, the filter name and the filter description.
A content filter header line for a filter called <quote>foo</quote> could look
like this:
</para>
<para>
<screen>FILTER: foo Replace all "foo" with "bar"</screen>
</para>
<para>
Below that line, and up to the next header line, come the jobs that
define what text replacements the filter executes. They are specified
in a syntax that imitates <ulink url="http://www.perl.org/">Perl</ulink>'s
<literal>s///</literal> operator. If you are familiar with Perl, you
will find this to be quite intuitive, and may want to look at the
PCRS documentation for the subtle differences to Perl behaviour. Most
notably, the non-standard option letter <literal>U</literal> is supported,
which turns the default to ungreedy matching.
</para>
<para>
If you are new to
<ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
Expressions</quote></ulink>, you might want to take a look at
the <link linkend="regex">Appendix on regular expressions</link>, and
see the <ulink url="http://perldoc.perl.org/perlre.html">Perl
manual</ulink> for
<ulink url="http://perldoc.perl.org/perlop.html">the
<literal>s///</literal> operator's syntax</ulink> and <ulink
url="http://perldoc.perl.org/perlre.html">Perl-style regular
expressions</ulink> in general.
The below examples might also help to get you started.
</para>
<!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
<sect2><title>Filter File Tutorial</title>
<para>
Now, let's complete our <quote>foo</quote> content filter. We have already defined
the heading, but the jobs are still missing. Since all it does is to replace
<quote>foo</quote> with <quote>bar</quote>, there is only one (trivial) job
needed:
</para>
<para>
<screen>s/foo/bar/</screen>
</para>
<para>
But wait! Didn't the comment say that <emphasis>all</emphasis> occurrences
of <quote>foo</quote> should be replaced? Our current job will only take
care of the first <quote>foo</quote> on each page. For global substitution,
we'll need to add the <literal>g</literal> option:
</para>
<para>
<screen>s/foo/bar/g</screen>
</para>
<para>
Our complete filter now looks like this:
</para>
<para>
<screen>FILTER: foo Replace all "foo" with "bar"
s/foo/bar/g</screen>
</para>
<para>
Let's look at some real filters for more interesting examples. Here you see
a filter that protects against some common annoyances that arise from JavaScript
abuse. Let's look at its jobs one after the other:
</para>
<para>
<screen>
FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse
# Get rid of JavaScript referrer tracking. Test page: http://www.randomoddness.com/untitled.htm
#
s|(&lt;script.*)document\.referrer(.*&lt;/script&gt;)|$1"Not Your Business!"$2|Usg</screen>
</para>
<para>
Following the header line and a comment, you see the job. Note that it uses
<literal>|</literal> as the delimiter instead of <literal>/</literal>, because
the pattern contains a forward slash, which would otherwise have to be escaped
by a backslash (<literal>\</literal>).
</para>
<para>
Now, let's examine the pattern: it starts with the text <literal>&lt;script.*</literal>
enclosed in parentheses. Since the dot matches any character, and <literal>*</literal>
means: <quote>Match an arbitrary number of the element left of myself</quote>, this
matches <quote>&lt;script</quote>, followed by <emphasis>any</emphasis> text, i.e.
it matches the whole page, from the start of the first &lt;script&gt; tag.
</para>
<para>
That's more than we want, but the pattern continues: <literal>document\.referrer</literal>
matches only the exact string <quote>document.referrer</quote>. The dot needed to
be <emphasis>escaped</emphasis>, i.e. preceded by a backslash, to take away its
special meaning as a joker, and make it just a regular dot. So far, the meaning is:
Match from the start of the first &lt;script&gt; tag in a the page, up to, and including,
the text <quote>document.referrer</quote>, if <emphasis>both</emphasis> are present
in the page (and appear in that order).
</para>
<para>
But there's still more pattern to go. The next element, again enclosed in parentheses,
is <literal>.*&lt;/script&gt;</literal>. You already know what <literal>.*</literal>
means, so the whole pattern translates to: Match from the start of the first &lt;script&gt;
tag in a page to the end of the last &lt;script&gt; tag, provided that the text
<quote>document.referrer</quote> appears somewhere in between.
</para>
<para>
This is still not the whole story, since we have ignored the options and the parentheses:
The portions of the page matched by sub-patterns that are enclosed in parentheses, will be
remembered and be available through the variables <literal>$1, $2, ...</literal> in
the substitute. The <literal>U</literal> option switches to ungreedy matching, which means
that the first <literal>.*</literal> in the pattern will only <quote>eat up</quote> all
text in between <quote>&lt;script</quote> and the <emphasis>first</emphasis> occurrence
of <quote>document.referrer</quote>, and that the second <literal>.*</literal> will
only span the text up to the <emphasis>first</emphasis> <quote>&lt;/script&gt;</quote>
tag. Furthermore, the <literal>s</literal> option says that the match may span
multiple lines in the page, and the <literal>g</literal> option again means that the
substitution is global.
</para>
<para>
So, to summarize, the pattern means: Match all scripts that contain the text
<quote>document.referrer</quote>. Remember the parts of the script from
(and including) the start tag up to (and excluding) the string
<quote>document.referrer</quote> as <literal>$1</literal>, and the part following
that string, up to and including the closing tag, as <literal>$2</literal>.
</para>
<para>
Now the pattern is deciphered, but wasn't this about substituting things? So
lets look at the substitute: <literal>$1"Not Your Business!"$2</literal> is
easy to read: The text remembered as <literal>$1</literal>, followed by
<literal>"Not Your Business!"</literal> (<emphasis>including</emphasis>
the quotation marks!), followed by the text remembered as <literal>$2</literal>.
This produces an exact copy of the original string, with the middle part
(the <quote>document.referrer</quote>) replaced by <literal>"Not Your
Business!"</literal>.
</para>
<para>
The whole job now reads: Replace <quote>document.referrer</quote> by
<literal>"Not Your Business!"</literal> wherever it appears inside a
&lt;script&gt tag. Note that this job won't break JavaScript syntax,
since both the original and the replacement are syntactically valid
string objects. The script just won't have access to the referrer
information anymore.
</para>
<para>
We'll show you two other jobs from the JavaScript taming department, but
this time only point out the constructs of special interest:
</para>
<para>
<screen>
# The status bar is for displaying link targets, not pointless blahblah
#
s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig</screen>
</para>
<para>
<literal>\s</literal> stands for whitespace characters (space, tab, newline,
carriage return, form feed), so that <literal>\s*</literal> means: <quote>zero
or more whitespace</quote>. The <literal>?</literal> in <literal>.*?</literal>
makes this matching of arbitrary text ungreedy. (Note that the <literal>U</literal>
option is not set). The <literal>['"]</literal> construct means: <quote>a single
<emphasis>or</emphasis> a double quote</quote>. Finally, <literal>\1</literal> is
a back-reference to the first parenthesis just like <literal>$1</literal> above,
with the difference that in the <emphasis>pattern</emphasis>, a backslash indicates
a back-reference, whereas in the <emphasis>substitute</emphasis>, it's the dollar.
</para>
<para>
So what does this job do? It replaces assignments of single- or double-quoted
strings to the <quote>window.status</quote> object with a dummy assignment
(using a variable name that is hopefully odd enough not to conflict with
real variables in scripts). Thus, it catches many cases where e.g. pointless
descriptions are displayed in the status bar instead of the link target when
you move your mouse over links.
</para>
<para>
<screen>
# Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html
#
s/(&lt;body [^&gt;]*)onunload(.*&gt;)/$1never$2/iU</screen>
</para>
<para>
Including the
<ulink url="http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-htmlevents">OnUnload
event binding</ulink> in the HTML DOM was a <emphasis>CRIME</emphasis>.
When I close a browser window, I want it to close and die. Basta.
This job replaces the <quote>onunload</quote> attribute in
<quote>&lt;body&gt</quote> tags with the dummy word <literal>never</literal>.
Note that the <literal>i</literal> option makes the pattern matching
case-insensitive. Also note that ungreedy matching alone doesn't always guarantee
a minimal match: In the first parenthesis, we had to use <literal>[^&gt;]*</literal>
instead of <literal>.*</literal> to prevent the match from exceeding the
&lt;body&gt tag if it doesn't contain <quote>OnUnload</quote>, but the page's
content does.
</para>
<para>
The last example is from the fun department:
</para>
<para>
<screen>
FILTER: fun Fun text replacements
# Spice the daily news:
#
s/microsoft(?!\.com)/MicroSuck/ig</screen>
</para>
<para>
Note the <literal>(?!\.com)</literal> part (a so-called negative lookahead)
in the job's pattern, which means: Don't match, if the string
<quote>.com</quote> appears directly following <quote>microsoft</quote>
in the page. This prevents links to microsoft.com from being trashed, while
still replacing the word everywhere else.
</para>
<para>
<screen>
# Buzzword Bingo (example for extended regex syntax)
#
s* industry[ -]leading \
| cutting[ -]edge \
| customer[ -]focused \
| market[ -]driven \
| award[ -]winning # Comments are OK, too! \
| high[ -]performance \
| solutions[ -]based \
| unmatched \
| unparalleled \
| unrivalled \
*&lt;font color="red"&gt;&lt;b&gt;BINGO!&lt;/b&gt;&lt;/font&gt; \
*igx</screen>
</para>
<para>
The <literal>x</literal> option in this job turns on extended syntax, and allows for
e.g. the liberal use of (non-interpreted!) whitespace for nicer formatting.
</para>
<para>
You get the idea?
</para>
</sect2>
<!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
<sect2 id="predefined-filters"><title>The Pre-defined Filters</title>
<!--
Note each filter is also listed in the +filter action section above. Please
keep these listings in sync.
-->
<para>
The distribution <filename>default.filter</filename> file contains a selection of
pre-defined filters for your convenience:
</para>
<variablelist>
<varlistentry>
<term><emphasis>js-annoyances</emphasis></term>
<listitem>
<para>
The purpose of this filter is to get rid of particularly annoying JavaScript abuse.
To that end, it
<itemizedlist>
<listitem>
<para>
replaces JavaScript references to the browser's referrer information
with the string "Not Your Business!". This compliments the <literal><link
linkend="hide-referrer">hide-referrer</link></literal> action on the content level.
</para>
</listitem>
<listitem>
<para>
removes the bindings to the DOM's
<ulink url="http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-htmlevents">unload
event</ulink> which we feel has no right to exist and is responsible for most <quote>exit consoles</quote>, i.e.
nasty windows that pop up when you close another one.
</para>
</listitem>
<listitem>
<para>
removes code that causes new windows to be opened with undesired properties, such as being
full-screen, non-resizeable, without location, status or menu bar etc.
</para>
</listitem>
</itemizedlist>
</para>
<para>
Use with caution. This is an aggressive filter, and can break sites that
rely heavily on JavaScript.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>js-events</emphasis></term>
<listitem>
<para>
This is a very radical measure. It removes virtually all JavaScript event bindings, which
means that scripts can not react to user actions such as mouse movements or clicks, window
resizing etc, anymore. Use with caution!
</para>
<para>
We <emphasis>strongly discourage</emphasis> using this filter as a default since it breaks
many legitimate scripts. It is meant for use only on extra-nasty sites (should you really
need to go there).
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>html-annoyances</emphasis></term>
<listitem>
<para>
This filter will undo many common instances of HTML based abuse.
</para>
<para>
The <literal>BLINK</literal> and <literal>MARQUEE</literal> tags
are neutralized (yeah baby!), and browser windows will be created as
resizeable (as of course they should be!), and will have location,
scroll and menu bars -- even if specified otherwise.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>content-cookies</emphasis></term>
<listitem>
<para>
Most cookies are set in the HTTP dialog, where they can be intercepted
by the
<literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal>
and <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal>
actions. But web sites increasingly make use of HTML meta tags and JavaScript
to sneak cookies to the browser on the content level.
</para>
<para>
This filter disables most HTML and JavaScript code that reads or sets
cookies. It cannot detect all clever uses of these types of code, so it
should not be relied on as an absolute fix. Use it wherever you would also
use the cookie crunch actions.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>refresh tags</emphasis></term>
<listitem>
<para>
Disable any refresh tags if the interval is greater than nine seconds (so
that redirections done via refresh tags are not destroyed). This is useful
for dial-on-demand setups, or for those who find this HTML feature
annoying.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>unsolicited-popups</emphasis></term>
<listitem>
<para>
This filter attempts to prevent only <quote>unsolicited</quote> pop-up
windows from opening, yet still allow pop-up windows that the user
has explicitly chosen to open. It was added in version 3.0.1,
as an improvement over earlier such filters.
</para>
<para>
Technical note: The filter works by redefining the window.open JavaScript
function to a dummy function, <literal>PrivoxyWindowOpen()</literal>,
during the loading and rendering phase of each HTML page access, and
restoring the function afterward.
</para>
<para>
This is recommended only for browsers that cannot perform this function
reliably themselves. And be aware that some sites require such windows
in order to function normally. Use with caution.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>all-popups</emphasis></term>
<listitem>
<para>
Attempt to prevent <emphasis>all</emphasis> pop-up windows from opening.
Note this should be used with even more discretion than the above, since
it is more likely to break some sites that require pop-ups for normal
usage. Use with caution.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>img-reorder</emphasis></term>
<listitem>
<para>
This is a helper filter that has no value if used alone. It makes the
<literal>banners-by-size</literal> and <literal>banners-by-link</literal>
(see below) filters more effective and should be enabled together with them.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>banners-by-size</emphasis></term>
<listitem>
<para>
This filter removes image tags purely based on what size they are. Fortunately
for us, many ads and banner images tend to conform to certain standardized
sizes, which makes this filter quite effective for ad stripping purposes.
</para>
<para>
Occasionally this filter will cause false positives on images that are not ads,
but just happen to be of one of the standard banner sizes.
</para>
<para>
Recommended only for those who require extreme ad blocking. The default
block rules should catch 95+% of all ads <emphasis>without</emphasis> this filter enabled.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>banners-by-link</emphasis></term>
<listitem>
<para>
This is an experimental filter that attempts to kill any banners if
their URLs seem to point to known or suspected click trackers. It is currently
not of much value and is not recommended for use by default.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>webbugs</emphasis></term>
<listitem>
<para>
Webbugs are small, invisible images (technically 1X1 GIF images), that
are used to track users across websites, and collect information on them.
As an HTML page is loaded by the browser, an embedded image tag causes the
browser to contact a third-party site, disclosing the tracking information
through the requested URL and/or cookies for that third-party domain, without
the user ever becoming aware of the interaction with the third-party site.
HTML-ized spam also uses a similar technique to verify email addresses.
</para>
<para>
This filter removes the HTML code that loads such <quote>webbugs</quote>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>tiny-textforms</emphasis></term>
<listitem>
<para>
A rather special-purpose filter that can be used to enlarge textareas (those
multi-line text boxes in web forms) and turn off hard word wrap in them.
It was written for the sourceforge.net tracker system where such boxes are
a nuisance, but it can be handy on other sites, too.
</para>
<para>
It is not recommended to use this filter as a default.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>jumping-windows</emphasis></term>
<listitem>
<para>
Many consider windows that move, or resize themselves to be abusive. This filter
neutralizes the related JavaScript code. Note that some sites might not display
or behave as intended when using this filter. Use with caution.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>frameset-borders</emphasis></term>
<listitem>
<para>
Some web designers seem to assume that everyone in the world will view their
web sites using the same browser brand and version, screen resolution etc,
because only that assumption could explain why they'd use static frame sizes,
yet prevent their frames from being resized by the user, should they be too
small to show their whole content.
</para>
<para>
This filter removes the related HTML code. It should only be applied to sites
which need it.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>demoronizer</emphasis></term>
<listitem>
<para>
Many Microsoft products that generate HTML use non-standard extensions (read:
violations) of the ISO 8859-1 aka Latin-1 character set. This can cause those
HTML documents to display with errors on standard-compliant platforms.
</para>
<para>
This filter translates the MS-only characters into Latin-1 equivalents.
It is not necessary when using MS products, and will cause corruption of
all documents that use 8-bit character sets other than Latin-1. It's mostly
worthwhile for Europeans on non-MS platforms, if weird garbage characters
sometimes appear on some pages, or user agents that don't correct for this on
the fly.
<!--
My version of Mozilla (ancient) shows litte square boxes for quote
characters, and apostrophes on moronized pages. So many pages have this, I
can read them fine now. HB 08/27/06
-->
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>shockwave-flash</emphasis></term>
<listitem>
<para>
A filter for shockwave haters. As the name suggests, this filter strips code
out of web pages that is used to embed shockwave flash objects.
</para>
<para>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>quicktime-kioskmode</emphasis></term>
<listitem>
<para>
Change HTML code that embeds Quicktime objects so that kioskmode, which
prevents saving, is disabled.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>fun</emphasis></term>
<listitem>
<para>
Text replacements for subversive browsing fun. Make fun of your favorite
Monopolist or play buzzword bingo.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>crude-parental</emphasis></term>
<listitem>
<para>
A demonstration-only filter that shows how <application>Privoxy</application>
can be used to delete web content on a keyword basis.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>ie-exploits</emphasis></term>
<listitem>
<para>
An experimental collection of text replacements to disable malicious HTML and JavaScript
code that exploits known security holes in Internet Explorer.
</para>
<para>
Presently, it only protects against Nimda and a cross-site scripting bug, and
would need active maintenance to provide more substantial protection.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>site-specifics</emphasis></term>
<listitem>
<para>
Some web sites have very specific problems, the cure for which doesn't apply
anywhere else, or could even cause damage on other sites.
</para>
<para>
This is a collection of such site-specific cures which should only be applied
to the sites they were intended for, which is what the supplied
<filename>default.action</filename> file does. Users shouldn't need to change
anything regarding this filter.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>google</emphasis></term>
<listitem>
<para>
A CSS based block for Google text ads. Also removes a width limitation
and the toolbar advertisement.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>yahoo</emphasis></term>
<listitem>
<para>
Another CSS based block, this time for Yahoo text ads. And removes
a width limitation as well.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>msn</emphasis></term>
<listitem>
<para>
Another CSS based block, this time for MSN text ads. And removes
tracking URLs, as well as a width limitation.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>blogspot</emphasis></term>
<listitem>
<para>
Cleans up some Blogspot blogs. Read the fine print before using this one!
</para>
<para>
This filter also intentionally removes some navigation stuff and sets the
page width to 100%. As a result, some rounded <quote>corners</quote> would
appear to early or not at all and as fixing this would require a browser
that understands background-size (CSS3), they are removed instead.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>xml-to-html</emphasis></term>
<listitem>
<para>
Server-header filter to change the Content-Type from xml to html.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>html-to-xml</emphasis></term>
<listitem>
<para>
Server-header filter to change the Content-Type from html to xml.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>no-ping</emphasis></term>
<listitem>
<para>
Removes the non-standard <literal>ping</literal> attribute from
anchor and area HTML tags.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><emphasis>hide-tor-exit-notation</emphasis></term>
<listitem>
<para>
Client-header filter to remove the <command>Tor</command> exit node notation
found in Host and Referer headers.
</para>
<para>
If &my-app; and <command>Tor</command> are chained and &my-app;
is configured to use socks4a, one can use <quote>http://www.example.org.foobar.exit/</quote>
to access the host <quote>www.example.org</quote> through the
<command>Tor</command> exit node <quote>foobar</quote>.
</para>
<para>
As the HTTP client isn't aware of this notation, it treats the
whole string <quote>www.example.org.foobar.exit</quote> as host and uses it
for the <quote>Host</quote> and <quote>Referer</quote> headers. From the
server's point of view the resulting headers are invalid and can cause problems.
</para>
<para>
An invalid <quote>Referer</quote> header can trigger <quote>hot-linking</quote>
protections, an invalid <quote>Host</quote> header will make it impossible for
the server to find the right vhost (several domains hosted on the same IP address).
</para>
<para>
This client-header filter removes the <quote>foo.exit</quote> part in those headers
to prevent the mentioned problems. Note that it only modifies
the HTTP headers, it doesn't make it impossible for the server
to detect your <command>Tor</command> exit node based on the IP address
the request is coming from.
</para>
</listitem>
</varlistentry>
<!--
<varlistentry>
<term><emphasis> </emphasis></term>
<listitem>
<para>
</para>
<para>
</para>
</listitem>
</varlistentry>
-->
</variablelist>
</sect2>
</sect1>
<!-- ~ End section ~ -->
<!-- ~~~~~ New section ~~~~~ -->
<sect1 id="templates">
<title>Privoxy's Template Files</title>
<para>
All <application>Privoxy</application> built-in pages, i.e. error pages such as the
<ulink url="http://show-the-404-error.page"><quote>404 - No Such Domain</quote>
error page</ulink>, the <ulink
url="http://ads.bannerserver.example.com/nasty-ads/sponsor.html"><quote>BLOCKED</quote>
page</ulink>
and all pages of its <ulink url="http://config.privoxy.org/">web-based
user interface</ulink>, are generated from <emphasis>templates</emphasis>.
(<application>Privoxy</application> must be running for the above links to work as
intended.)
</para>
<para>
These templates are stored in a subdirectory of the <link linkend="confdir">configuration
directory</link> called <filename>templates</filename>. On Unixish platforms,
this is typically
<ulink url="file:///etc/privoxy/templates/"><filename>/etc/privoxy/templates/</filename></ulink>.
</para>
<para>
The templates are basically normal HTML files, but with place-holders (called symbols
or exports), which <application>Privoxy</application> fills at run time. It
is possible to edit the templates with a normal text editor, should you want
to customize them. (<emphasis>Not recommended for the casual
user</emphasis>). Should you create your own custom templates, you should use
the <filename>config</filename> setting <link linkend="templdir">templdir</link>
to specify an alternate location, so your templates do not get overwritten
during upgrades.
</para>
<para>
Note that just like in configuration files, lines starting
with <literal>#</literal> are ignored when the templates are filled in.
</para>
<para>
The place-holders are of the form <literal>@name@</literal>, and you will
find a list of available symbols, which vary from template to template,
in the comments at the start of each file. Note that these comments are not
always accurate, and that it's probably best to look at the existing HTML
code to find out which symbols are supported and what they are filled in with.
</para>
<para>
A special application of this substitution mechanism is to make whole
blocks of HTML code disappear when a specific symbol is set. We use this
for many purposes, one of them being to include the beta warning in all
our user interface (CGI) pages when <application>Privoxy</application>
is in an alpha or beta development stage:
</para>
<para>
<screen>
&lt;!-- @if-unstable-start --&gt;
... beta warning HTML code goes here ...
&lt;!-- if-unstable-end@ --&gt;</screen>
</para>
<para>
If the "unstable" symbol is set, everything in between and including
<literal>@if-unstable-start</literal> and <literal>if-unstable-end@</literal>
will disappear, leaving nothing but an empty comment:
</para>
<para>
<screen>&lt;!-- --&gt;</screen>
</para>
<para>
There's also an if-then-else construct and an <literal>#include</literal>
mechanism, but you'll sure find out if you are inclined to edit the
templates ;-)
</para>
<para>
All templates refer to a style located at
<ulink url="http://config.privoxy.org/send-stylesheet"><literal>http://config.privoxy.org/send-stylesheet</literal></ulink>.
This is, of course, locally served by <application>Privoxy</application>
and the source for it can be found and edited in the
<filename>cgi-style.css</filename> template.
</para>
</sect1>
<!-- ~ End section ~ -->
<!-- ~~~~~ New section ~~~~~ -->
<sect1 id="contact"><title>Contacting the Developers, Bug Reporting and Feature
Requests</title>
<!-- Include contacting.sgml boilerplate: -->
&contacting;
<!-- end boilerplate -->
</sect1>
<!-- ~ End section ~ -->
<!-- ~~~~~ New section ~~~~~ -->
<sect1 id="copyright"><title>Privoxy Copyright, License and History</title>
<!-- Include copyright.sgml: -->
&copyright;
<!-- end copyright -->
<!-- ~~~~~ New section ~~~~~ -->
<sect2><title>License</title>
<!-- Include copyright.sgml: -->
&license;
<!-- end copyright -->
</sect2>
<!-- ~ End section ~ -->
<!-- ~~~~~ New section ~~~~~ -->
<sect2 id="history"><title>History</title>
<!-- Include history.sgml: -->
&history;
<!-- end history -->
</sect2>
<sect2 id="authors"><title>Authors</title>
<!-- Include p-authors.sgml: -->
&p-authors;
<!-- end authors -->
</sect2>
</sect1>
<!-- ~ End section ~ -->
<!-- ~~~~~ New section ~~~~~ -->
<sect1 id="seealso"><title>See Also</title>
<!-- Include seealso.sgml: -->
&seealso;
<!-- end seealso -->
</sect1>
<!-- ~~~~~ New section ~~~~~ -->
<sect1 id="appendix"><title>Appendix</title>
<!-- ~~~~~ New section ~~~~~ -->
<sect2 id="regex">
<title>Regular Expressions</title>
<para>
<application>Privoxy</application> uses Perl-style <quote>regular
expressions</quote> in its <link linkend="actions-file">actions
files</link> and <link linkend="filter-file">filter file</link>,
through the <ulink url="http://www.pcre.org/">PCRE</ulink> and
<!--
dead 08/27/06
<ulink url="http://www.oesterhelt.org/pcrs/">PCRS</ulink> libraries.
-->
<application>PCRS</application> libraries.
</para>
<para>
If you are reading this, you probably don't understand what <quote>regular
expressions</quote> are, or what they can do. So this will be a very brief
introduction only. A full explanation would require a <ulink
url="http://www.oreilly.com/catalog/regex/">book</ulink> ;-)
</para>
<para>
Regular expressions provide a language to describe patterns that can be
run against strings of characters (letter, numbers, etc), to see if they
match the string or not. The patterns are themselves (sometimes complex)
strings of literal characters, combined with wild-cards, and other special
characters, called meta-characters. The <quote>meta-characters</quote> have
special meanings and are used to build complex patterns to be matched against.
Perl Compatible Regular Expressions are an especially convenient
<quote>dialect</quote> of the regular expression language.
</para>
<para>
To make a simple analogy, we do something similar when we use wild-card
characters when listing files with the <command>dir</command> command in DOS.
<literal>*.*</literal> matches all filenames. The <quote>special</quote>
character here is the asterisk which matches any and all characters. We can be
more specific and use <literal>?</literal> to match just individual
characters. So <quote>dir file?.text</quote> would match
<quote>file1.txt</quote>, <quote>file2.txt</quote>, etc. We are pattern
matching, using a similar technique to <quote>regular expressions</quote>!
</para>
<para>
Regular expressions do essentially the same thing, but are much, much more
powerful. There are many more <quote>special characters</quote> and ways of
building complex patterns however. Let's look at a few of the common ones,
and then some examples:
</para>
<para><simplelist>
<member>
<emphasis>.</emphasis> - Matches any single character, e.g. <quote>a</quote>,
<quote>A</quote>, <quote>4</quote>, <quote>:</quote>, or <quote>@</quote>.
</member>
</simplelist></para>
<para><simplelist>
<member>
<emphasis>?</emphasis> - The preceding character or expression is matched ZERO or ONE
times. Either/or.
</member>
</simplelist></para>
<para><simplelist>
<member>
<emphasis>+</emphasis> - The preceding character or expression is matched ONE or MORE
times.
</member>
</simplelist></para>
<para><simplelist>
<member>
<emphasis>*</emphasis> - The preceding character or expression is matched ZERO or MORE
times.
</member>
</simplelist></para>
<para><simplelist>
<member>
<emphasis>\</emphasis> - The <quote>escape</quote> character denotes that
the following character should be taken literally. This is used where one of the
special characters (e.g. <quote>.</quote>) needs to be taken literally and
not as a special meta-character. Example: <quote>example\.com</quote>, makes
sure the period is recognized only as a period (and not expanded to its
meta-character meaning of any single character).
</member>
</simplelist></para>
<para><simplelist>
<member>
<emphasis>[ ]</emphasis> - Characters enclosed in brackets will be matched if
any of the enclosed characters are encountered. For instance, <quote>[0-9]</quote>
matches any numeric digit (zero through nine). As an example, we can combine
this with <quote>+</quote> to match any digit one of more times: <quote>[0-9]+</quote>.
</member>
</simplelist></para>
<para><simplelist>
<member>
<emphasis>( )</emphasis> - parentheses are used to group a sub-expression,
or multiple sub-expressions.
</member>
</simplelist></para>
<para><simplelist>
<member>
<emphasis>|</emphasis> - The <quote>bar</quote> character works like an
<quote>or</quote> conditional statement. A match is successful if the
sub-expression on either side of <quote>|</quote> matches. As an example:
<quote>/(this|that) example/</quote> uses grouping and the bar character
and would match either <quote>this example</quote> or <quote>that
example</quote>, and nothing else.
</member>
</simplelist></para>
<para>
These are just some of the ones you are likely to use when matching URLs with
<application>Privoxy</application>, and is a long way from a definitive
list. This is enough to get us started with a few simple examples which may
be more illuminating:
</para>
<para>
<emphasis><literal>/.*/banners/.*</literal></emphasis> - A simple example
that uses the common combination of <quote>.</quote> and <quote>*</quote> to
denote any character, zero or more times. In other words, any string at all.
So we start with a literal forward slash, then our regular expression pattern
(<quote>.*</quote>) another literal forward slash, the string
<quote>banners</quote>, another forward slash, and lastly another
<quote>.*</quote>. We are building
a directory path here. This will match any file with the path that has a
directory named <quote>banners</quote> in it. The <quote>.*</quote> matches
any characters, and this could conceivably be more forward slashes, so it
might expand into a much longer looking path. For example, this could match:
<quote>/eye/hate/spammers/banners/annoy_me_please.gif</quote>, or just
<quote>/banners/annoying.html</quote>, or almost an infinite number of other
possible combinations, just so it has <quote>banners</quote> in the path
somewhere.
</para>
<para>
And now something a little more complex:
</para>
<para>
<emphasis><literal>/.*/adv((er)?ts?|ertis(ing|ements?))?/</literal></emphasis> -
We have several literal forward slashes again (<quote>/</quote>), so we are
building another expression that is a file path statement. We have another
<quote>.*</quote>, so we are matching against any conceivable sub-path, just so
it matches our expression. The only true literal that <emphasis>must
match</emphasis> our pattern is <application>adv</application>, together with
the forward slashes. What comes after the <quote>adv</quote> string is the
interesting part.
</para>
<para>
Remember the <quote>?</quote> means the preceding expression (either a
literal character or anything grouped with <quote>(...)</quote> in this case)
can exist or not, since this means either zero or one match. So
<quote>((er)?ts?|ertis(ing|ements?))</quote> is optional, as are the
individual sub-expressions: <quote>(er)</quote>,
<quote>(ing|ements?)</quote>, and the <quote>s</quote>. The <quote>|</quote>
means <quote>or</quote>. We have two of those. For instance,
<quote>(ing|ements?)</quote>, can expand to match either <quote>ing</quote>
<emphasis>OR</emphasis> <quote>ements?</quote>. What is being done here, is an
attempt at matching as many variations of <quote>advertisement</quote>, and
similar, as possible. So this would expand to match just <quote>adv</quote>,
or <quote>advert</quote>, or <quote>adverts</quote>, or
<quote>advertising</quote>, or <quote>advertisement</quote>, or
<quote>advertisements</quote>. You get the idea. But it would not match
<quote>advertizements</quote> (with a <quote>z</quote>). We could fix that by
changing our regular expression to:
<quote>/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/</quote>, which would then match
either spelling.
</para>
<para>
<emphasis><literal>/.*/advert[0-9]+\.(gif|jpe?g)</literal></emphasis> - Again
another path statement with forward slashes. Anything in the square brackets
<quote>[ ]</quote> can be matched. This is using <quote>0-9</quote> as a
shorthand expression to mean any digit one through nine. It is the same as
saying <quote>0123456789</quote>. So any digit matches. The <quote>+</quote>
means one or more of the preceding expression must be included. The preceding
expression here is what is in the square brackets -- in this case, any digit
one through nine. Then, at the end, we have a grouping: <quote>(gif|jpe?g)</quote>.
This includes a <quote>|</quote>, so this needs to match the expression on
either side of that bar character also. A simple <quote>gif</quote> on one side, and the other
side will in turn match either <quote>jpeg</quote> or <quote>jpg</quote>,
since the <quote>?</quote> means the letter <quote>e</quote> is optional and
can be matched once or not at all. So we are building an expression here to
match image GIF or JPEG type image file. It must include the literal
string <quote>advert</quote>, then one or more digits, and a <quote>.</quote>
(which is now a literal, and not a special character, since it is escaped
with <quote>\</quote>), and lastly either <quote>gif</quote>, or
<quote>jpeg</quote>, or <quote>jpg</quote>. Some possible matches would
include: <quote>//advert1.jpg</quote>,
<quote>/nasty/ads/advert1234.gif</quote>,
<quote>/banners/from/hell/advert99.jpg</quote>. It would not match
<quote>advert1.gif</quote> (no leading slash), or
<quote>/adverts232.jpg</quote> (the expression does not include an
<quote>s</quote>), or <quote>/advert1.jsp</quote> (<quote>jsp</quote> is not
in the expression anywhere).
</para>
<para>
We are barely scratching the surface of regular expressions here so that you
can understand the default <application>Privoxy</application>
configuration files, and maybe use this knowledge to customize your own
installation. There is much, much more that can be done with regular
expressions. Now that you know enough to get started, you can learn more on
your own :/
</para>
<para>
More reading on Perl Compatible Regular expressions:
<ulink url="http://perldoc.perl.org/perlre.html">http://perldoc.perl.org/perlre.html</ulink>
</para>
<para>
For information on regular expression based substitutions and their applications
in filters, please see the <link linkend="filter-file">filter file tutorial</link>
in this manual.
</para>
</sect2>
<!-- ~ End section ~ -->
<!-- ~~~~~ New section ~~~~~ -->
<sect2>
<title>Privoxy's Internal Pages</title>
<para>
Since <application>Privoxy</application> proxies each requested
web page, it is easy for <application>Privoxy</application> to
trap certain special URLs. In this way, we can talk directly to
<application>Privoxy</application>, and see how it is
configured, see how our rules are being applied, change these
rules and other configuration options, and even turn
<application>Privoxy's</application> filtering off, all with
a web browser.
</para>
<para>
The URLs listed below are the special ones that allow direct access
to <application>Privoxy</application>. Of course,
<application>Privoxy</application> must be running to access these. If
not, you will get a friendly error message. Internet access is not
necessary either.
</para>
<para>
<itemizedlist>
<listitem>
<para>
Privoxy main page:
</para>
<blockquote>
<para>
<ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
</para>
</blockquote>
<para>
There is a shortcut: <ulink url="http://p.p/">http://p.p/</ulink> (But it
doesn't provide a fall-back to a real page, in case the request is not
sent through <application>Privoxy</application>)
</para>
</listitem>
<listitem>
<para>
Show information about the current configuration, including viewing and
editing of actions files:
</para>
<blockquote>
<para>
<ulink url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
</para>
</blockquote>
</listitem>
<listitem>
<para>
Show the source code version numbers:
</para>
<blockquote>
<para>
<ulink url="http://config.privoxy.org/show-version">http://config.privoxy.org/show-version</ulink>
</para>
</blockquote>
</listitem>
<listitem>
<para>
Show the browser's request headers:
</para>
<blockquote>
<para>
<ulink url="http://config.privoxy.org/show-request">http://config.privoxy.org/show-request</ulink>
</para>
</blockquote>
</listitem>
<listitem>
<para>
Show which actions apply to a URL and why:
</para>
<blockquote>
<para>
<ulink url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
</para>
</blockquote>
</listitem>
<listitem>
<para>
Toggle Privoxy on or off. This feature can be turned off/on in the main
<filename>config</filename> file. When toggled <quote>off</quote>, <quote>Privoxy</quote>
continues to run, but only as a pass-through proxy, with no actions taking
place:
</para>
<blockquote>
<para>
<ulink url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>
</para>
</blockquote>
<para>
Short cuts. Turn off, then on:
</para>
<blockquote>
<para>
<ulink url="http://config.privoxy.org/toggle?set=disable">http://config.privoxy.org/toggle?set=disable</ulink>
</para>
</blockquote>
<blockquote>
<para>
<ulink url="http://config.privoxy.org/toggle?set=enable">http://config.privoxy.org/toggle?set=enable</ulink>
</para>
</blockquote>
</listitem>
</itemizedlist>
</para>
<para>
These may be bookmarked for quick reference. See next.
</para>
<sect3 id="bookmarklets">
<title>Bookmarklets</title>
<para>
Below are some <quote>bookmarklets</quote> to allow you to easily access a
<quote>mini</quote> version of some of <application>Privoxy's</application>
special pages. They are designed for MS Internet Explorer, but should work
equally well in Netscape, Mozilla, and other browsers which support
JavaScript. They are designed to run directly from your bookmarks - not by
clicking the links below (although that should work for testing).
</para>
<para>
To save them, right-click the link and choose <quote>Add to Favorites</quote>
(IE) or <quote>Add Bookmark</quote> (Netscape). You will get a warning that
the bookmark <quote>may not be safe</quote> - just click OK. Then you can run the
Bookmarklet directly from your favorites/bookmarks. For even faster access,
you can put them on the <quote>Links</quote> bar (IE) or the <quote>Personal
Toolbar</quote> (Netscape), and run them with a single click.
</para>
<para>
<itemizedlist>
<listitem>
<para>
<ulink
url="javascript:void(window.open('http://config.privoxy.org/toggle?mini=y&#38;set=enabled','ijbstatus','width=250,height=100,resizable=yes,scrollbars=no,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());">Privoxy - Enable</ulink>
</para>
</listitem>
<listitem>
<para>
<ulink
url="javascript:void(window.open('http://config.privoxy.org/toggle?mini=y&#38;set=disabled','ijbstatus','width=250,height=100,resizable=yes,scrollbars=no,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());">Privoxy - Disable</ulink>
</para>
</listitem>
<listitem>
<para>
<ulink
url="javascript:void(window.open('http://config.privoxy.org/toggle?mini=y&#38;set=toggle','ijbstatus','width=250,height=100,resizable=yes,scrollbars=no,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());">Privoxy - Toggle Privoxy</ulink> (Toggles between enabled and disabled)
</para>
</listitem>
<listitem>
<para>
<ulink
url="javascript:void(window.open('http://config.privoxy.org/toggle?mini=y','ijbstatus','width=250,height=2,resizable=yes,scrollbars=no,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());">Privoxy- View Status</ulink>
</para>
</listitem>
<!--
<listitem>
<para>
<ulink url="javascript:w=Math.floor(screen.width/2);h=Math.floor(screen.height*0.9);void(window.open('http://www.privoxy.org/actions/index.php?url='+escape(location.href),'Feedback','screenx='+w+',width='+w+',height='+h+',scrollbars=yes,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());">Privoxy - Submit Actions File Feedback</ulink>
</para>
</listitem>
-->
<listitem>
<para>
<ulink url="javascript:void(window.open('http://config.privoxy.org/show-url-info?url='+escape(location.href),'Why').focus());">Privoxy - Why?</ulink>
</para>
</listitem>
</itemizedlist>
</para>
<para>
Credit: The site which gave us the general idea for these bookmarklets is
<ulink url="http://www.bookmarklets.com/">www.bookmarklets.com</ulink>. They
have more information about bookmarklets.
</para>
</sect3>
</sect2>
<!-- ~~~~~ New section ~~~~~ -->
<sect2 id="chain">
<title>Chain of Events</title>
<para>
Let's take a quick look at how some of <application>Privoxy's</application>
core features are triggered, and the ensuing sequence of events when a web
page is requested by your browser:
</para>
<para>
<itemizedlist>
<listitem>
<para>
First, your web browser requests a web page. The browser knows to send
the request to <application>Privoxy</application>, which will in turn,
relay the request to the remote web server after passing the following
tests:
</para>
</listitem>
<listitem>
<para>
<application>Privoxy</application> traps any request for its own internal CGI
pages (e.g <ulink url="http://p.p/">http://p.p/</ulink>) and sends the CGI page back to the browser.
</para>
</listitem>
<listitem>
<para>
Next, <application>Privoxy</application> checks to see if the URL
matches any <link
linkend="BLOCK"><quote>+block</quote></link> patterns. If
so, the URL is then blocked, and the remote web server will not be contacted.
<link linkend="HANDLE-AS-IMAGE"><quote>+handle-as-image</quote></link>
and
<link linkend="HANDLE-AS-EMPTY-DOCUMENT"><quote>+handle-as-empty-document</quote></link>
are then checked, and if there is no match, an
HTML <quote>BLOCKED</quote> page is sent back to the browser. Otherwise, if
it does match, an image is returned for the former, and an empty text
document for the latter. The type of image would depend on the setting of
<link linkend="SET-IMAGE-BLOCKER"><quote>+set-image-blocker</quote></link>
(blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
</para>
</listitem>
<listitem>
<para>
Untrusted URLs are blocked. If URLs are being added to the
<filename>trust</filename> file, then that is done.
</para>
</listitem>
<listitem>
<para>
If the URL pattern matches the <link
linkend="FAST-REDIRECTS"><quote>+fast-redirects</quote></link> action,
it is then processed. Unwanted parts of the requested URL are stripped.
</para>
</listitem>
<listitem>
<para>
Now the rest of the client browser's request headers are processed. If any
of these match any of the relevant actions (e.g. <link
linkend="HIDE-USER-AGENT"><quote>+hide-user-agent</quote></link>,
etc.), headers are suppressed or forged as determined by these actions and
their parameters.
</para>
</listitem>
<listitem>
<para>
Now the web server starts sending its response back (i.e. typically a web
page).
</para>
</listitem>
<listitem>
<para>
First, the server headers are read and processed to determine, among other
things, the MIME type (document type) and encoding. The headers are then
filtered as determined by the
<link linkend="CRUNCH-INCOMING-COOKIES"><quote>+crunch-incoming-cookies</quote></link>,
<link linkend="SESSION-COOKIES-ONLY"><quote>+session-cookies-only</quote></link>,
and <link linkend="DOWNGRADE-HTTP-VERSION"><quote>+downgrade-http-version</quote></link>
actions.
</para>
</listitem>
<listitem>
<para>
If any <link linkend="FILTER"><quote>+filter</quote></link> action
or <link
linkend="DEANIMATE-GIFS"><quote>+deanimate-gifs</quote></link>
action applies (and the document type fits the action), the rest of the page is
read into memory (up to a configurable limit). Then the filter rules (from
<filename>default.filter</filename> and any other filter files) are
processed against the buffered content. Filters are applied in the order
they are specified in one of the filter files. Animated GIFs, if present,
are reduced to either the first or last frame, depending on the action
setting.The entire page, which is now filtered, is then sent by
<application>Privoxy</application> back to your browser.
</para>
<para>
If neither a <link linkend="FILTER"><quote>+filter</quote></link> action
or <link
linkend="DEANIMATE-GIFS"><quote>+deanimate-gifs</quote></link>
matches, then <application>Privoxy</application> passes the raw data through
to the client browser as it becomes available.
</para>
</listitem>
<listitem>
<para>
As the browser receives the now (possibly filtered) page content, it
reads and then requests any URLs that may be embedded within the page
source, e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
frames), sounds, etc. For each of these objects, the browser issues a
separate request (this is easily viewable in <application>Privoxy's</application>
logs). And each such request is in turn processed just as above. Note that a
complex web page will have many, many such embedded URLs. If these
secondary requests are to a different server, then quite possibly a very
differing set of actions is triggered.
</para>
</listitem>
</itemizedlist>
</para>
<para>
NOTE: This is somewhat of a simplistic overview of what happens with each URL
request. For the sake of brevity and simplicity, we have focused on
<application>Privoxy's</application> core features only.
</para>
</sect2>
<!-- ~~~~~ New section ~~~~~ -->
<sect2 id="actionsanat">
<title>Troubleshooting: Anatomy of an Action</title>
<para>
The way <application>Privoxy</application> applies
<link linkend="ACTIONS">actions</link> and <link linkend="FILTER">filters</link>
to any given URL can be complex, and not always so
easy to understand what is happening. And sometimes we need to be able to
<emphasis>see</emphasis> just what <application>Privoxy</application> is
doing. Especially, if something <application>Privoxy</application> is doing
is causing us a problem inadvertently. It can be a little daunting to look at
the actions and filters files themselves, since they tend to be filled with
<link linkend="regex">regular expressions</link> whose consequences are not
always so obvious.
</para>
<para>
One quick test to see if <application>Privoxy</application> is causing a problem
or not, is to disable it temporarily. This should be the first troubleshooting
step. See <link linkend="bookmarklets">the Bookmarklets</link> section on a quick
and easy way to do this (be sure to flush caches afterward!). Looking at the
logs is a good idea too. (Note that both the toggle feature and logging are
enabled via <filename>config</filename> file settings, and may need to be
turned <quote>on</quote>.)
</para>
<para>
Another easy troubleshooting step to try is if you have done any
customization of your installation, revert back to the installed
defaults and see if that helps. There are times the developers get complaints
about one thing or another, and the problem is more related to a customized
configuration issue.
</para>
<para>
<application>Privoxy</application> also provides the
<ulink url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
page that can show us very specifically how <application>actions</application>
are being applied to any given URL. This is a big help for troubleshooting.
</para>
<para>
First, enter one URL (or partial URL) at the prompt, and then
<application>Privoxy</application> will tell us
how the current configuration will handle it. This will not
help with filtering effects (i.e. the <link
linkend="FILTER"><quote>+filter</quote></link> action) from
one of the filter files since this is handled very
differently and not so easy to trap! It also will not tell you about any other
URLs that may be embedded within the URL you are testing. For instance, images
such as ads are expressed as URLs within the raw page source of HTML pages. So
you will only get info for the actual URL that is pasted into the prompt area
-- not any sub-URLs. If you want to know about embedded URLs like ads, you
will have to dig those out of the HTML source. Use your browser's <quote>View
Page Source</quote> option for this. Or right click on the ad, and grab the
URL.
</para>
<para>
Let's try an example, <ulink url="http://google.com">google.com</ulink>,
and look at it one section at a time in a sample configuration (your real
configuration may vary):
</para>
<para>
<screen>
Matches for http://www.google.com:
In file: default.action <guibutton>[ View ]</guibutton> <guibutton>[ Edit ]</guibutton>
{+change-x-forwarded-for{block}
+deanimate-gifs {last}
+fast-redirects {check-decoded-url}
+filter {refresh-tags}
+filter {img-reorder}
+filter {banners-by-size}
+filter {webbugs}
+filter {jumping-windows}
+filter {ie-exploits}
+hide-from-header {block}
+hide-referrer {forge}
+session-cookies-only
+set-image-blocker {pattern}
/
{ -session-cookies-only }
.google.com
{ -fast-redirects }
.google.com
In file: user.action <guibutton>[ View ]</guibutton> <guibutton>[ Edit ]</guibutton>
(no matches in this file)
</screen>
</para>
<para>
This is telling us how we have defined our
<link linkend="ACTIONS"><quote>actions</quote></link>, and
which ones match for our test case, <quote>google.com</quote>.
Displayed is all the actions that are available to us. Remember,
the <literal>+</literal> sign denotes <quote>on</quote>. <literal>-</literal>
denotes <quote>off</quote>. So some are <quote>on</quote> here, but many
are <quote>off</quote>. Each example we try may provide a slightly different
end result, depending on our configuration directives.
</para>
<para>
The first listing
is for our <filename>default.action</filename> file. The large, multi-line
listing, is how the actions are set to match for all URLs, i.e. our default
settings. If you look at your <quote>actions</quote> file, this would be the
section just below the <quote>aliases</quote> section near the top. This
will apply to all URLs as signified by the single forward slash at the end
of the listing -- <quote> / </quote>.
</para>
<para>
But we have defined additional actions that would be exceptions to these general
rules, and then we list specific URLs (or patterns) that these exceptions
would apply to. Last match wins. Just below this then are two explicit
matches for <quote>.google.com</quote>. The first is negating our previous
cookie setting, which was for <link
linkend="SESSION-COOKIES-ONLY"><quote>+session-cookies-only</quote></link>
(i.e. not persistent). So we will allow persistent cookies for google, at
least that is how it is in this example. The second turns
<emphasis>off</emphasis> any <link
linkend="FAST-REDIRECTS"><quote>+fast-redirects</quote></link>
action, allowing this to take place unmolested. Note that there is a leading
dot here -- <quote>.google.com</quote>. This will match any hosts and
sub-domains, in the google.com domain also, such as
<quote>www.google.com</quote> or <quote>mail.google.com</quote>. But it would not
match <quote>www.google.de</quote>! So, apparently, we have these two actions
defined as exceptions to the general rules at the top somewhere in the lower
part of our <filename>default.action</filename> file, and
<quote>google.com</quote> is referenced somewhere in these latter sections.
</para>
<para>
Then, for our <filename>user.action</filename> file, we again have no hits.
So there is nothing google-specific that we might have added to our own, local
configuration. If there was, those actions would over-rule any actions from
previously processed files, such as <filename>default.action</filename>.
<filename>user.action</filename> typically has the last word. This is the
best place to put hard and fast exceptions,
</para>
<para>
And finally we pull it all together in the bottom section and summarize how
<application>Privoxy</application> is applying all its <quote>actions</quote>
to <quote>google.com</quote>:
</para>
<para>
<screen>
Final results:
-add-header
-block
+change-x-forwarded-for{block}
-client-header-filter{hide-tor-exit-notation}
-content-type-overwrite
-crunch-client-header
-crunch-if-none-match
-crunch-incoming-cookies
-crunch-outgoing-cookies
-crunch-server-header
+deanimate-gifs {last}
-downgrade-http-version
-fast-redirects
-filter {js-events}
-filter {content-cookies}
-filter {all-popups}
-filter {banners-by-link}
-filter {tiny-textforms}
-filter {frameset-borders}
-filter {demoronizer}
-filter {shockwave-flash}
-filter {quicktime-kioskmode}
-filter {fun}
-filter {crude-parental}
-filter {site-specifics}
-filter {js-annoyances}
-filter {html-annoyances}
+filter {refresh-tags}
-filter {unsolicited-popups}
+filter {img-reorder}
+filter {banners-by-size}
+filter {webbugs}
+filter {jumping-windows}
+filter {ie-exploits}
-filter {google}
-filter {yahoo}
-filter {msn}
-filter {blogspot}
-filter {no-ping}
-force-text-mode
-handle-as-empty-document
-handle-as-image
-hide-accept-language
-hide-content-disposition
+hide-from-header {block}
-hide-if-modified-since
+hide-referrer {forge}
-hide-user-agent
-limit-connect
-overwrite-last-modified
-prevent-compression
-redirect
-server-header-filter{xml-to-html}
-server-header-filter{html-to-xml}
-session-cookies-only
+set-image-blocker {pattern} </screen>
</para>
<para>
Notice the only difference here to the previous listing, is to
<quote>fast-redirects</quote> and <quote>session-cookies-only</quote>,
which are activated specifically for this site in our configuration,
and thus show in the <quote>Final Results</quote>.
</para>
<para>
Now another example, <quote>ad.doubleclick.net</quote>:
</para>
<para>
<screen>
{ +block{Domains starts with "ad"} }
ad*.
{ +block{Domain contains "ad"} }
.ad.
{ +block{Doubleclick banner server} +handle-as-image }
.[a-vx-z]*.doubleclick.net
</screen>
</para>
<para>
We'll just show the interesting part here - the explicit matches. It is
matched three different times. Two <quote>+block{}</quote> sections,
and a <quote>+block{} +handle-as-image</quote>,
which is the expanded form of one of our aliases that had been defined as:
<quote>+block-as-image</quote>. (<link
linkend="ALIASES"><quote>Aliases</quote></link> are defined in
the first section of the actions file and typically used to combine more
than one action.)
</para>
<para>
Any one of these would have done the trick and blocked this as an unwanted
image. This is unnecessarily redundant since the last case effectively
would also cover the first. No point in taking chances with these guys
though ;-) Note that if you want an ad or obnoxious
URL to be invisible, it should be defined as <quote>ad.doubleclick.net</quote>
is done here -- as both a <link
linkend="BLOCK"><quote>+block{}</quote></link>
<emphasis>and</emphasis> an
<link linkend="HANDLE-AS-IMAGE"><quote>+handle-as-image</quote></link>.
The custom alias <quote><literal>+block-as-image</literal></quote> just
simplifies the process and make it more readable.
</para>
<para>
One last example. Let's try <quote>http://www.example.net/adsl/HOWTO/</quote>.
This one is giving us problems. We are getting a blank page. Hmmm ...
</para>
<para>
<screen>
Matches for http://www.example.net/adsl/HOWTO/:
In file: default.action <guibutton>[ View ]</guibutton> <guibutton>[ Edit ]</guibutton>
{-add-header
-block
+change-x-forwarded-for{block}
-client-header-filter{hide-tor-exit-notation}
-content-type-overwrite
-crunch-client-header
-crunch-if-none-match
-crunch-incoming-cookies
-crunch-outgoing-cookies
-crunch-server-header
+deanimate-gifs
-downgrade-http-version
+fast-redirects {check-decoded-url}
-filter {js-events}
-filter {content-cookies}
-filter {all-popups}
-filter {banners-by-link}
-filter {tiny-textforms}
-filter {frameset-borders}
-filter {demoronizer}
-filter {shockwave-flash}
-filter {quicktime-kioskmode}
-filter {fun}
-filter {crude-parental}
-filter {site-specifics}
-filter {js-annoyances}
-filter {html-annoyances}
+filter {refresh-tags}
-filter {unsolicited-popups}
+filter {img-reorder}
+filter {banners-by-size}
+filter {webbugs}
+filter {jumping-windows}
+filter {ie-exploits}
-filter {google}
-filter {yahoo}
-filter {msn}
-filter {blogspot}
-filter {no-ping}
-force-text-mode
-handle-as-empty-document
-handle-as-image
-hide-accept-language
-hide-content-disposition
+hide-from-header{block}
+hide-referer{forge}
-hide-user-agent
-overwrite-last-modified
+prevent-compression
-redirect
-server-header-filter{xml-to-html}
-server-header-filter{html-to-xml}
+session-cookies-only
+set-image-blocker{blank} }
/
{ +block{Path contains "ads".} +handle-as-image }
/ads
</screen>
</para>
<para>
Ooops, the <quote>/adsl/</quote> is matching <quote>/ads</quote> in our
configuration! But we did not want this at all! Now we see why we get the
blank page. It is actually triggering two different actions here, and
the effects are aggregated so that the URL is blocked, and &my-app; is told
to treat the block as if it were an image. But this is, of course, all wrong.
We could now add a new action below this (or better in our own
<filename>user.action</filename> file) that explicitly
<emphasis>un</emphasis> blocks (
<link linkend="BLOCK"><quote>{-block}</quote></link>) paths with
<quote>adsl</quote> in them (remember, last match in the configuration
wins). There are various ways to handle such exceptions. Example:
</para>
<para>
<screen>
{ -block }
/adsl
</screen>
</para>
<para>
Now the page displays ;-)
Remember to flush your browser's caches when making these kinds of changes to
your configuration to insure that you get a freshly delivered page! Or, try
using <literal>Shift+Reload</literal>.
</para>
<para>
But now what about a situation where we get no explicit matches like
we did with:
</para>
<para>
<screen>
{ +block{Path starts with "ads".} +handle-as-image }
/ads
</screen>
</para>
<para>
That actually was very helpful and pointed us quickly to where the problem
was. If you don't get this kind of match, then it means one of the default
rules in the first section of <filename>default.action</filename> is causing
the problem. This would require some guesswork, and maybe a little trial and
error to isolate the offending rule. One likely cause would be one of the
<link linkend="FILTER"><quote>+filter</quote></link> actions.
These tend to be harder to troubleshoot.
Try adding the URL for the site to one of aliases that turn off
<link linkend="FILTER"><quote>+filter</quote></link>:
</para>
<para>
<screen>
{ shop }
.quietpc.com
.worldpay.com # for quietpc.com
.jungle.com
.scan.co.uk
.forbes.com
</screen>
</para>
<para>
<quote><literal>{ shop }</literal></quote> is an <quote>alias</quote> that expands to
<quote><literal>{ -filter -session-cookies-only }</literal></quote>.
Or you could do your own exception to negate filtering:
</para>
<para>
<screen>
{ -filter }
# Disable ALL filter actions for sites in this section
.forbes.com
developer.ibm.com
localhost
</screen>
</para>
<para>
This would turn off all filtering for these sites. This is best
put in <filename>user.action</filename>, for local site
exceptions. Note that when a simple domain pattern is used by itself (without
the subsequent path portion), all sub-pages within that domain are included
automatically in the scope of the action.
</para>
<para>
Images that are inexplicably being blocked, may well be hitting the
<link linkend="FILTER-BANNERS-BY-SIZE"><quote>+filter{banners-by-size}</quote></link>
rule, which assumes
that images of certain sizes are ad banners (works well
<emphasis>most of the time</emphasis> since these tend to be standardized).
</para>
<para>
<quote><literal>{ fragile }</literal></quote> is an alias that disables most
actions that are the most likely to cause trouble. This can be used as a
last resort for problem sites.
</para>
<para>
<screen>
{ fragile }
# Handle with care: easy to break
mail.google.
mybank.example.com</screen>
</para>
<para>
<emphasis>Remember to flush caches!</emphasis> Note that the
<literal>mail.google</literal> reference lacks the TLD portion (e.g.
<quote>.com</quote>). This will effectively match any TLD with
<literal>google</literal> in it, such as <literal>mail.google.de.</literal>,
just as an example.
</para>
<para>
If this still does not work, you will have to go through the remaining
actions one by one to find which one(s) is causing the problem.
</para>
</sect2>
</sect1>
<!--
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and/or modify it under the terms of the GNU General
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your option) any later version.
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be useful, but WITHOUT ANY WARRANTY; without even the
implied warranty of MERCHANTABILITY or FITNESS FOR A
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The GNU General Public License should be included with
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or write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
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$Log: user-manual.sgml,v $
Revision 2.103 2009/03/21 10:49:05 fabiankeil
Merge updated ChangeLog.
Revision 2.102 2009/03/15 19:31:36 fabiankeil
Update "What's New in this Release" section.
Revision 2.101 2009/02/25 19:01:56 fabiankeil
Fix typo.
Revision 2.100 2009/02/19 17:14:11 fabiankeil
- Copy the release cycle description from announce.txt into
the "What's New" section.
- Stop referring to the ChangeLog for a "complete list of changes".
The "What's New" section already contains the complete list.
Revision 2.99 2009/02/19 02:20:22 hal9
Make some links in seealso conditional. Man page is now privoxy only links.
Revision 2.98 2009/02/16 17:10:33 fabiankeil
Fix entry about shortened log messages. Noticed by Lee.
Revision 2.97 2009/02/14 18:01:00 fabiankeil
Import ChangeLog.
Revision 2.96 2009/02/14 13:14:03 fabiankeil
Unbreak syntax.
Revision 2.95 2009/02/14 12:51:26 fabiankeil
Mention match-all.action in the "Actions Files Tutorial" section.
Revision 2.94 2009/02/14 11:50:31 fabiankeil
Some indentation fixes.
Revision 2.93 2009/02/14 10:14:42 fabiankeil
Mention match-all.action in the action file descriptions.
Revision 2.92 2009/02/12 16:08:26 fabiankeil
Declare the code stable.
Revision 2.91 2009/01/13 16:50:35 fabiankeil
The standard.action file is gone.
Revision 2.90 2008/09/26 16:53:09 fabiankeil
Update "What's new" section.
Revision 2.89 2008/09/21 15:38:56 fabiankeil
Fix Portage tree sync instructions in Gentoo section.
Anonymously reported at ijbswa-developers@.
Revision 2.88 2008/09/21 14:42:52 fabiankeil
Add documentation for change-x-forwarded-for{},
remove documentation for hide-forwarded-for-headers.
Revision 2.87 2008/08/30 15:37:35 fabiankeil
Update entities.
Revision 2.86 2008/08/16 10:12:23 fabiankeil
Merge two sentences and move the URL to the end of the item.
Revision 2.85 2008/08/16 10:04:59 fabiankeil
Some more syntax fixes. This version actually builds.
Revision 2.84 2008/08/16 09:42:45 fabiankeil
Turns out building docs works better if the syntax is valid.
Revision 2.83 2008/08/16 09:32:02 fabiankeil
Mention changes since 3.0.9 beta.
Revision 2.82 2008/08/16 09:00:52 fabiankeil
Fix example URL pattern (once more with feeling).
Revision 2.81 2008/08/16 08:51:28 fabiankeil
Update version-related entities.
Revision 2.80 2008/07/18 16:54:30 fabiankeil
Remove erroneous whitespace in documentation link.
Reported by John Chronister in #2021611.
Revision 2.79 2008/06/27 18:00:53 markm68k
remove outdated startup information for mac os x
Revision 2.78 2008/06/21 17:03:03 fabiankeil
Fix typo.
Revision 2.77 2008/06/14 13:45:22 fabiankeil
Re-add a colon I unintentionally removed a few revisions ago.
Revision 2.76 2008/06/14 13:21:28 fabiankeil
Prepare for the upcoming 3.0.9 beta release.
Revision 2.75 2008/06/13 16:06:48 fabiankeil
Update the "What's New in this Release" section with
the ChangeLog entries changelog2doc.pl could handle.
Revision 2.74 2008/05/26 15:55:46 fabiankeil
- Update "default profiles" table.
- Add some more pcrs redirect examples and note that
enabling debug 128 helps to get redirects working.
Revision 2.73 2008/05/23 14:43:18 fabiankeil
Remove previously out-commented block that caused syntax problems.
Revision 2.72 2008/05/12 10:26:14 fabiankeil
Synchronize content filter descriptions with the ones in default.filter.
Revision 2.71 2008/04/10 17:37:16 fabiankeil
Actually we use "modern" POSIX 1003.2 regular
expressions in path patterns, not PCRE.
Revision 2.70 2008/04/10 15:59:12 fabiankeil
Add another section to the client-header-tagger example that shows
how to actually change the action settings once the tag is created.
Revision 2.69 2008/03/29 12:14:25 fabiankeil
Remove send-wafer and send-vanilla-wafer actions.
Revision 2.68 2008/03/28 15:13:43 fabiankeil
Remove inspect-jpegs action.
Revision 2.67 2008/03/27 18:31:21 fabiankeil
Remove kill-popups action.
Revision 2.66 2008/03/06 16:33:47 fabiankeil
If limit-connect isn't used, don't limit CONNECT requests to port 443.
Revision 2.65 2008/03/04 18:30:40 fabiankeil
Remove the treat-forbidden-connects-like-blocks action. We now
use the "blocked" page for forbidden CONNECT requests by default.
Revision 2.64 2008/03/01 14:10:28 fabiankeil
Use new block syntax. Still needs some polishing.
Revision 2.63 2008/02/22 05:50:37 markm68k
fix merge problem
Revision 2.62 2008/02/11 11:52:23 hal9
Fix entity ... s/&/&amp;
Revision 2.61 2008/02/11 03:41:47 markm68k
more updates for mac os x
Revision 2.60 2008/02/11 03:40:25 markm68k
more updates for mac os x
Revision 2.59 2008/02/11 00:52:34 markm68k
reflect new changes for mac os x
Revision 2.58 2008/02/03 21:37:40 hal9
Apply patch from Mark: s/OSX/OS X/
Revision 2.57 2008/02/03 19:10:14 fabiankeil
Mention forward-socks5.
Revision 2.56 2008/01/31 19:11:35 fabiankeil
Let the +client-header-filter{hide-tor-exit-notation} example apply
to all requests as "tainted" Referers aren't limited to exit TLDs.
Revision 2.55 2008/01/19 21:26:37 hal9
Add IE7 to configuration section per Gerry.
Revision 2.54 2008/01/19 17:52:39 hal9
Re-commit to fix various minor issues for new release.
Revision 2.53 2008/01/19 15:03:05 hal9
Doc sources tagged for 3.0.8 release.
Revision 2.52 2008/01/17 01:49:51 hal9
Change copyright notice for docs s/2007/2008/. All these will be rebuilt soon
enough.
Revision 2.51 2007/12/23 16:48:24 fabiankeil
Use more precise example descriptions for the mysterious domain patterns.
Revision 2.50 2007/12/08 12:44:36 fabiankeil
- Remove already commented out pre-3.0.7 changes.
- Update the "new log defaults" paragraph.
Revision 2.49 2007/12/06 18:21:55 fabiankeil
Update hide-forwarded-for-headers description.
Revision 2.48 2007/11/24 19:07:17 fabiankeil
- Mention request rewriting.
- Enable the conditional-forge paragraph.
- Minor rewordings.
Revision 2.47 2007/11/18 14:59:47 fabiankeil
A few "Note to Upgraders" updates.
Revision 2.46 2007/11/17 17:24:44 fabiankeil
- Use new action defaults.
- Minor fixes and rewordings.
Revision 2.45 2007/11/16 11:48:46 hal9
Fix one typo, and add a couple of small refinements.
Revision 2.44 2007/11/15 03:30:20 hal9
Results of spell check.
Revision 2.43 2007/11/14 18:45:39 fabiankeil
- Mention some more contributors in the "New in this Release" list.
- Minor rewordings.
Revision 2.42 2007/11/12 03:32:40 hal9
Updates for "What's New" and "Notes to Upgraders". Various other changes in
preparation for new release. User Manual is almost ready.
Revision 2.41 2007/11/11 16:32:11 hal9
This is primarily syncing What's New and Note to Upgraders sections with the many
new features and changes (gleaned from memory but mostly from ChangeLog).
Revision 2.40 2007/11/10 17:10:59 fabiankeil
In the first third of the file, mention several times that
the action editor is disabled by default in 3.0.7 beta and later.
Revision 2.39 2007/11/05 02:34:49 hal9
Various changes in preparation for the upcoming release. Much yet to be done.
Revision 2.38 2007/09/22 16:01:42 fabiankeil
Update embedded show-url-info output.
Revision 2.37 2007/08/27 16:09:55 fabiankeil
Fix pre-chroot-nslookup description which I failed to
copy and paste properly. Reported by Stephen Gildea.
Revision 2.36 2007/08/26 16:47:14 fabiankeil
Add Stephen Gildea's pre-chroot-nslookup patch [#1276666],
extensive comments moved to user manual.
Revision 2.35 2007/08/26 14:59:49 fabiankeil
Minor rewordings and fixes.
Revision 2.34 2007/08/05 15:19:50 fabiankeil
- Don't claim HTTP/1.1 compliance.
- Use $ in some of the path pattern examples.
- Use a hide-user-agent example argument without
leading and trailing space.
- Make it clear that the cookie actions work with
HTTP cookies only.
- Rephrase the inspect-jpegs text to underline
that it's only meant to protect against a single
exploit.
Revision 2.33 2007/07/27 10:57:35 hal9
Add references for user-agent strings for hide-user-agenet
Revision 2.32 2007/06/07 12:36:22 fabiankeil
Apply Roland's 29_usermanual.dpatch to fix a bunch
of syntax errors I collected over the last months.
Revision 2.31 2007/06/02 14:01:37 fabiankeil
Start to document forward-override{}.
Revision 2.30 2007/04/25 15:10:36 fabiankeil
- Describe installation for FreeBSD.
- Start to document taggers and tag patterns.
- Don't confuse devils and daemons.
Revision 2.29 2007/04/05 11:47:51 fabiankeil
Some updates regarding header filtering,
handling of compressed content and redirect's
support for pcrs commands.
Revision 2.28 2006/12/10 23:42:48 hal9
Fix various typos reported by Adam P. Thanks.
Revision 2.27 2006/11/14 01:57:47 hal9
Dump all docs prior to 3.0.6 release. Various minor changes to faq and user
manual.
Revision 2.26 2006/10/24 11:16:44 hal9
Add new filters.
Revision 2.25 2006/10/18 10:50:33 hal9
Add note that since filters are off in Cautious, compression is ON. Turn off
compression to make filters work on all sites.
Revision 2.24 2006/10/03 11:13:54 hal9
More references to the new filters. Include html this time around.
Revision 2.23 2006/10/02 22:43:53 hal9
Contains new filter definitions from Fabian, and few other miscellaneous
touch-ups.
Revision 2.22 2006/09/22 01:27:55 hal9
Final commit of probably various minor changes here and there. Unless
something changes this should be ready for pending release.
Revision 2.21 2006/09/20 03:21:36 david__schmidt
Just the tiniest tweak. Wafer thin!
Revision 2.20 2006/09/10 14:53:54 hal9
Results of spell check. User manual has some updates to standard.actions file
info.
Revision 2.19 2006/09/08 12:19:02 fabiankeil
Adjust hide-if-modified-since example values
to reflect the recent changes.
Revision 2.18 2006/09/08 02:38:57 hal9
Various changes:
-Fix a number of broken links.
-Migrate the new Windows service command line options, and reference as
needed.
-Rebuild so that can be used with the new "user-manual" config capabilities.
-Etc.
Revision 2.17 2006/09/05 13:25:12 david__schmidt
Add Windows service invocation stuff (duplicated) in FAQ and in user manual under Windows startup. One probably ought to reference the other.
Revision 2.16 2006/09/02 12:49:37 hal9
Various small updates for new actions, filterfiles, etc.
Revision 2.15 2006/08/30 11:15:22 hal9
More work on the new actions, especially filter-*-headers, and What's New
section. User Manual is close to final form for 3.0.4 release. Some tinkering
and proof reading left to do.
Revision 2.14 2006/08/29 10:59:36 hal9
Add a "Whats New in this release" Section. Further work on multiple filter
files, and assorted other minor changes.
Revision 2.13 2006/08/22 11:04:59 hal9
Silence warnings and errors. This should build now. New filters were only
stubbed in. More to be done.
Revision 2.12 2006/08/14 08:40:39 fabiankeil
Documented new actions that were part of
the "minor Privoxy improvements".
Revision 2.11 2006/07/18 14:48:51 david__schmidt
Reorganizing the repository: swapping out what was HEAD (the old 3.1 branch)
with what was really the latest development (the v_3_0_branch branch)
Revision 1.123.2.43 2005/05/23 09:59:10 hal9
Fix typo 'loose'
Revision 1.123.2.42 2004/12/04 14:39:57 hal9
Fix two minor typos per bug SF report.
Revision 1.123.2.41 2004/03/23 12:58:42 oes
Fixed an inaccuracy
Revision 1.123.2.40 2004/02/27 12:48:49 hal9
Add comment re: redirecting to local file system for set-image-blocker may
is dependent on browser.
Revision 1.123.2.39 2004/01/30 22:31:40 oes
Added a hint re bookmarklets to Quickstart section
Revision 1.123.2.38 2004/01/30 16:47:51 oes
Some minor clarifications
Revision 1.123.2.37 2004/01/29 22:36:11 hal9
Updates for no longer filtering text/plain, and demoronizer default settings,
and copyright notice dates.
Revision 1.123.2.36 2003/12/10 02:26:26 hal9
Changed the demoronizer filter description.
Revision 1.123.2.35 2003/11/06 13:36:37 oes
Updated link to nightly CVS tarball
Revision 1.123.2.34 2003/06/26 23:50:16 hal9
Add a small bit on filtering and problems re: source code being corrupted.
Revision 1.123.2.33 2003/05/08 18:17:33 roro
Use apt-get instead of dpkg to install Debian package, which is more
solid, uses the correct and most recent Debian version automatically.
Revision 1.123.2.32 2003/04/11 03:13:57 hal9
Add small note about only one filterfile (as opposed to multiple actions
files).
Revision 1.123.2.31 2003/03/26 02:03:43 oes
Updated hard-coded copyright dates
Revision 1.123.2.30 2003/03/24 12:58:56 hal9
Add new section on Predefined Filters.
Revision 1.123.2.29 2003/03/20 02:45:29 hal9
More problems with \-\-chroot causing markup problems :(
Revision 1.123.2.28 2003/03/19 00:35:24 hal9
Manual edit of revision log because 'chroot' (even inside a comment) was
causing Docbook to hang here (due to double hyphen and the processor thinking
it was a comment).
Revision 1.123.2.27 2003/03/18 19:37:14 oes
s/Advanced|Radical/Adventuresome/g to avoid complaints re fun filter
Revision 1.123.2.26 2003/03/17 16:50:53 oes
Added documentation for new chroot option
Revision 1.123.2.25 2003/03/15 18:36:55 oes
Adapted to the new filters
Revision 1.123.2.24 2002/11/17 06:41:06 hal9
Move default profiles table from FAQ to U-M, and other minor related changes.
Add faq on cookies.
Revision 1.123.2.23 2002/10/21 02:32:01 hal9
Updates to the user.action examples section. A few new ones.
Revision 1.123.2.22 2002/10/12 00:51:53 hal9
Add demoronizer to filter section.
Revision 1.123.2.21 2002/10/10 04:09:35 hal9
s/Advanced/Radical/ and added very brief note.
Revision 1.123.2.20 2002/10/10 03:49:21 hal9
Add notes to session-cookies-only and Quickstart about pre-existing
cookies. Also, note content-cookies work differently.
Revision 1.123.2.19 2002/09/26 01:25:36 hal9
More explanation on Privoxy patterns, more on content-cookies and SSL.
Revision 1.123.2.18 2002/08/22 23:47:58 hal9
Add 'Documentation' to Privoxy Menu shot in Configuration section to match
CGIs.
Revision 1.123.2.17 2002/08/18 01:13:05 hal9
Spell checked (only one typo this time!).
Revision 1.123.2.16 2002/08/09 19:20:54 david__schmidt
Update to Mac OS X startup script name
Revision 1.123.2.15 2002/08/07 17:32:11 oes
Converted some internal links from ulink to link for PDF creation; no content changed
Revision 1.123.2.14 2002/08/06 09:16:13 oes
Nits re: actions file download
Revision 1.123.2.13 2002/08/02 18:23:19 g_sauthoff
Just 2 small corrections to the Gentoo sections
Revision 1.123.2.12 2002/08/02 18:17:21 g_sauthoff
Added 2 Gentoo sections
Revision 1.123.2.11 2002/07/26 15:20:31 oes
- Added version info to title
- Added info on new filters
- Revised parts of the filter file tutorial
- Added info on where to get updated actions files
Revision 1.123.2.10 2002/07/25 21:42:29 hal9
Add brief notes on not proxying non-HTTP protocols.
Revision 1.123.2.9 2002/07/11 03:40:28 david__schmidt
Updated Mac OS X sections due to installation location change
Revision 1.123.2.8 2002/06/09 16:36:32 hal9
Clarifications on filtering and MIME. Hardcode 'latest release' in index.html.
Revision 1.123.2.7 2002/06/09 00:29:34 hal9
Touch ups on filtering, in actions section and Anatomy.
Revision 1.123.2.6 2002/06/06 23:11:03 hal9
Fix broken link. Linkchecked all docs.
Revision 1.123.2.5 2002/05/29 02:01:02 hal9
This is break out of the entire config section from u-m, so it can
eventually be used to generate the comments, etc in the main config file
so that these are in sync with each other.
Revision 1.123.2.4 2002/05/27 03:28:45 hal9
Ooops missed something from David.
Revision 1.123.2.3 2002/05/27 03:23:17 hal9
Fix FIXMEs for OS2 and Mac OS X startup. Fix Redhat typos (should be Red Hat).
That's a wrap, I think.
Revision 1.123.2.2 2002/05/26 19:02:09 hal9
Move Amiga stuff around to take of FIXME in start up section.
Revision 1.123.2.1 2002/05/26 17:04:25 hal9
-Spellcheck, very minor edits, and sync across branches
Revision 1.123 2002/05/24 23:19:23 hal9
Include new image (Proxy setup). More fun with guibutton.
Minor corrections/clarifications here and there.
Revision 1.122 2002/05/24 13:24:08 oes
Added Bookmarklet for one-click pre-filled access to show-url-info
Revision 1.121 2002/05/23 23:20:17 oes
- Changed more (all?) references to actions to the
<literal><link> style.
- Small fixes in the actions chapter
- Small clarifications in the quickstart to ad blocking
- Removed <emphasis> from <title>s since the new doc CSS
renders them red (bad in TOC).
Revision 1.120 2002/05/23 19:16:43 roro
Correct Debian specials (installation and startup).
Revision 1.119 2002/05/22 17:17:05 oes
Added Security hint
Revision 1.118 2002/05/21 04:54:55 hal9
-New Section: Quickstart to Ad Blocking
-Reformat Actions Anatomy to match new CGI layout
Revision 1.117 2002/05/17 13:56:16 oes
- Reworked & extended Templates chapter
- Small changes to Regex appendix
- #included authors.sgml into (C) and hist chapter
Revision 1.116 2002/05/17 03:23:46 hal9
Fixing merge conflict in Quickstart section.
Revision 1.115 2002/05/16 16:25:00 oes
Extended the Filter File chapter & minor fixes
Revision 1.114 2002/05/16 09:42:50 oes
More ulink->link, added some hints to Quickstart section
Revision 1.113 2002/05/15 21:07:25 oes
Extended and further commented the example actions files
Revision 1.112 2002/05/15 03:57:14 hal9
Spell check. A few minor edits here and there for better syntax and
clarification.
Revision 1.111 2002/05/14 23:01:36 oes
Fixing the fixes
Revision 1.110 2002/05/14 19:10:45 oes
Restored alphabetical order of actions
Revision 1.109 2002/05/14 17:23:11 oes
Renamed the prevent-*-cookies actions, extended aliases section and moved it before the example AFs
Revision 1.108 2002/05/14 15:29:12 oes
Completed proofreading the actions chapter
Revision 1.107 2002/05/12 03:20:41 hal9
Small clarifications for 127.0.0.1 vs localhost for listen-address since this
apparently an important distinction for some OS's.
Revision 1.106 2002/05/10 01:48:20 hal9
This is mostly proposed copyright/licensing additions and changes. Docs
are still GPL, but licensing and copyright are more visible. Also, copyright
changed in doc header comments (eliminate references to JB except FAQ).
Revision 1.105 2002/05/05 20:26:02 hal9
Sorting out license vs copyright in these docs.
Revision 1.104 2002/05/04 08:44:45 swa
bumped version
Revision 1.103 2002/05/04 00:40:53 hal9
-Remove the TOC first page kludge. It's fixed proper now in ldp.dsl.in.
-Some minor additions to Quickstart.
Revision 1.102 2002/05/03 17:46:00 oes
Further proofread & reactivated short build instructions
Revision 1.101 2002/05/03 03:58:30 hal9
Move the user-manual config directive to top of section. Add note about
Privoxy needing read permissions for configs, and write for logs.
Revision 1.100 2002/04/29 03:05:55 hal9
Add clarification on differences of new actions files.
Revision 1.99 2002/04/28 16:59:05 swa
more structure in starting section
Revision 1.98 2002/04/28 05:43:59 hal9
This is the break up of configuration.html into multiple files. This
will probably break links elsewhere :(
Revision 1.97 2002/04/27 21:04:42 hal9
-Rewrite of Actions File example.
-Add section for user-manual directive in config.
Revision 1.96 2002/04/27 05:32:00 hal9
-Add short section to Filter Files to tie in with +filter action.
-Start rewrite of examples in Actions Examples (not finished).
Revision 1.95 2002/04/26 17:23:29 swa
bookmarks cleaned, changed structure of user manual, screen and programlisting cleanups, and numerous other changes that I forgot
Revision 1.94 2002/04/26 05:24:36 hal9
-Add most of Andreas suggestions to Chain of Events section.
-A few other minor corrections and touch up.
Revision 1.92 2002/04/25 18:55:13 hal9
More catchups on new actions files, and new actions names.
Other assorted cleanups, and minor modifications.
Revision 1.91 2002/04/24 02:39:31 hal9
Add 'Chain of Events' section.
Revision 1.90 2002/04/23 21:41:25 hal9
Linuxconf is deprecated on RH, substitute chkconfig.
Revision 1.89 2002/04/23 21:05:28 oes
Added hint for startup on Red Hat
Revision 1.88 2002/04/23 05:37:54 hal9
Add AmigaOS install stuff.
Revision 1.87 2002/04/23 02:53:15 david__schmidt
Updated Mac OS X installation section
Added a few English tweaks here an there
Revision 1.86 2002/04/21 01:46:32 hal9
Re-write actions section.
Revision 1.85 2002/04/18 21:23:23 hal9
Fix ugly typo (mine).
Revision 1.84 2002/04/18 21:17:13 hal9
Spell Redhat correctly (ie Red Hat). A few minor grammar corrections.
Revision 1.83 2002/04/18 18:21:12 oes
Added RPM install detail
Revision 1.82 2002/04/18 12:04:50 oes
Cosmetics
Revision 1.81 2002/04/18 11:50:24 oes
Extended Install section - needs fixing by packagers
Revision 1.80 2002/04/18 10:45:19 oes
Moved text to buildsource.sgml, renamed some filters, details
Revision 1.79 2002/04/18 03:18:06 hal9
Spellcheck, and minor touchups.
Revision 1.78 2002/04/17 18:04:16 oes
Proofreading part 2
Revision 1.77 2002/04/17 13:51:23 oes
Proofreading, part one
Revision 1.76 2002/04/16 04:25:51 hal9
-Added 'Note to Upgraders' and re-ordered the 'Quickstart' section.
-Note about proxy may need requests to re-read config files.
Revision 1.75 2002/04/12 02:08:48 david__schmidt
Remove OS/2 building info... it is already in the developer-manual
Revision 1.74 2002/04/11 00:54:38 hal9
Add small section on submitting actions.
Revision 1.73 2002/04/10 18:45:15 swa
generated
Revision 1.72 2002/04/10 04:06:19 hal9
Added actions feedback to Bookmarklets section
Revision 1.71 2002/04/08 22:59:26 hal9
Version update. Spell chkconfig correctly :)
Revision 1.70 2002/04/08 20:53:56 swa
?
Revision 1.69 2002/04/06 05:07:29 hal9
-Add privoxy-man-page.sgml, for man page.
-Add authors.sgml for AUTHORS (and p-authors.sgml)
-Reworked various aspects of various docs.
-Added additional comments to sub-docs.
Revision 1.68 2002/04/04 18:46:47 swa
consistent look. reuse of copyright, history et. al.
Revision 1.67 2002/04/04 17:27:57 swa
more single file to be included at multiple points. make maintaining easier
Revision 1.66 2002/04/04 06:48:37 hal9
Structural changes to allow for conditional inclusion/exclusion of content
based on entity toggles, e.g. 'entity % p-not-stable "INCLUDE"'. And
definition of internal entities, e.g. 'entity p-version "2.9.13"' that will
eventually be set by Makefile.
More boilerplate text for use across multiple docs.
Revision 1.65 2002/04/03 19:52:07 swa
enhance squid section due to user suggestion
Revision 1.64 2002/04/03 03:53:43 hal9
A few minor bug fixes, and touch ups. Ready for review.
Revision 1.63 2002/04/01 16:24:49 hal9
Define entities to include boilerplate text. See doc/source/*.
Revision 1.62 2002/03/30 04:15:53 hal9
- Fix privoxy.org/config links.
- Paste in Bookmarklets from Toggle page.
- Move Quickstart nearer top, and minor rework.
Revision 1.61 2002/03/29 01:31:08 hal9
Minor update.
Revision 1.60 2002/03/27 01:57:34 hal9
Added more to Anatomy section.
Revision 1.59 2002/03/27 00:54:33 hal9
Touch up intro for new name.
Revision 1.58 2002/03/26 22:29:55 swa
we have a new homepage!
Revision 1.57 2002/03/24 20:33:30 hal9
A few minor catch ups with name change.
Revision 1.56 2002/03/24 16:17:06 swa
configure needs to be generated.
Revision 1.55 2002/03/24 16:08:08 swa
we are too lazy to make a block-built
privoxy logo. hence removed the option.
Revision 1.54 2002/03/24 15:46:20 swa
name change related issue.
Revision 1.53 2002/03/24 11:51:00 swa
name change. changed filenames.
Revision 1.52 2002/03/24 11:01:06 swa
name change
Revision 1.51 2002/03/23 15:13:11 swa
renamed every reference to the old name with foobar.
fixed "application foobar application" tag, fixed
"the foobar" with "foobar". left junkbustser in cvs
comments and remarks to history untouched.
Revision 1.50 2002/03/23 05:06:21 hal9
Touch up.
Revision 1.49 2002/03/21 17:01:05 hal9
New section in Appendix.
Revision 1.48 2002/03/12 06:33:01 hal9
Catching up to Andreas and re_filterfile changes.
Revision 1.47 2002/03/11 13:13:27 swa
correct feedback channels
Revision 1.46 2002/03/10 00:51:08 hal9
Added section on JB internal pages in Appendix.
Revision 1.45 2002/03/09 17:43:53 swa
more distros
Revision 1.44 2002/03/09 17:08:48 hal9
New section on Jon's actions file editor, and move some stuff around.
Revision 1.43 2002/03/08 00:47:32 hal9
Added imageblock{pattern}.
Revision 1.42 2002/03/07 18:16:55 swa
looks better
Revision 1.41 2002/03/07 16:46:43 hal9
Fix a few markup problems for jade.
Revision 1.40 2002/03/07 16:28:39 swa
provide correct feedback channels
Revision 1.39 2002/03/06 16:19:28 hal9
Note on perceived filtering slowdown per FR.
Revision 1.38 2002/03/05 23:55:14 hal9
Stupid I did it again. Double hyphen in comment breaks jade.
Revision 1.37 2002/03/05 23:53:49 hal9
jade barfs on '- -' embedded in comments. - -user option broke it.
Revision 1.36 2002/03/05 22:53:28 hal9
Add new - - user option.
Revision 1.35 2002/03/05 00:17:27 hal9
Added section on command line options.
Revision 1.34 2002/03/04 19:32:07 oes
Changed default port to 8118
Revision 1.33 2002/03/03 19:46:13 hal9
Emphasis on where/how to report bugs, etc
Revision 1.32 2002/03/03 09:26:06 joergs
AmigaOS changes, config is now loaded from PROGDIR: instead of
AmiTCP:db/junkbuster/ if no configuration file is specified on the
command line.
Revision 1.31 2002/03/02 22:45:52 david__schmidt
Just tweaking
Revision 1.30 2002/03/02 22:00:14 hal9
Updated 'New Features' list. Ran through spell-checker.
Revision 1.29 2002/03/02 20:34:07 david__schmidt
Update OS/2 build section
Revision 1.28 2002/02/24 14:34:24 jongfoster
Formatting changes. Now changing the doctype to DocBook XML 4.1
will work - no other changes are needed.
Revision 1.27 2002/01/11 14:14:32 hal9
Added a very short section on Templates
Revision 1.26 2002/01/09 20:02:50 hal9
Fix bug re: auto-detect config file changes.
Revision 1.25 2002/01/09 18:20:30 hal9
Touch ups for *.action files.
Revision 1.24 2001/12/02 01:13:42 hal9
Fix typo.
Revision 1.23 2001/12/02 00:20:41 hal9
Updates for recent changes.
Revision 1.22 2001/11/05 23:57:51 hal9
Minor update for startup now daemon mode.
Revision 1.21 2001/10/31 21:11:03 hal9
Correct 2 minor errors
Revision 1.18 2001/10/24 18:45:26 hal9
*** empty log message ***
Revision 1.17 2001/10/24 17:10:55 hal9
Catching up with Jon's recent work, and a few other things.
Revision 1.16 2001/10/21 17:19:21 swa
wrong url in documentation
Revision 1.15 2001/10/14 23:46:24 hal9
Various minor changes. Fleshed out SEE ALSO section.
Revision 1.13 2001/10/10 17:28:33 hal9
Very minor changes.
Revision 1.12 2001/09/28 02:57:04 hal9
Ditto :/
Revision 1.11 2001/09/28 02:25:20 hal9
Ditto.
Revision 1.9 2001/09/27 23:50:29 hal9
A few changes. A short section on regular expression in appendix.
Revision 1.8 2001/09/25 00:34:59 hal9
Some additions, and re-arranging.
Revision 1.7 2001/09/24 14:31:36 hal9
Diddling.
Revision 1.6 2001/09/24 14:10:32 hal9
Including David's OS/2 installation instructions.
Revision 1.2 2001/09/13 15:27:40 swa
cosmetics
Revision 1.1 2001/09/12 15:36:41 swa
source files for junkbuster documentation
Revision 1.3 2001/09/10 17:43:59 swa
first proposal of a structure.
Revision 1.2 2001/06/13 14:28:31 swa
docs should have an author.
Revision 1.1 2001/06/13 14:20:37 swa
first import of project's documentation for the webserver.
-->
</article>
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