[privoxy.git] / doc / source / user-manual.sgml

<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook V3.1//EN" [
<!entity % dummy "INCLUDE"> 
<!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 p-version "2.9.14">
<!entity p-status "beta">
<!entity % p-not-stable "INCLUDE">
<!entity % p-stable "IGNORE">
<!entity % p-text "IGNORE">        <!-- define we are not a text only doc -->
<!entity % p-doc "INCLUDE">        <!-- and we are a formal doc           -->
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<!--
 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 1.81 2002/04/18 11:50:24 oes Exp $

 Written by and Copyright (C) 2001 the SourceForge
 Privoxy team. http://www.privoxy.org/

 Based on the Internet Junkbuster originally written
 by and Copyright (C) 1997 Anonymous Coders and 
 Junkbusters Corporation.  http://www.junkbusters.com


 ========================================================================
 NOTE: Please read developer-manual/documentation.html before touching 
 anything in this, or other Privoxy documentation.
 ========================================================================

-->

<article id="index">
<artheader>
<title>Privoxy User Manual</title>

<pubdate>$Id: user-manual.sgml,v 1.81 2002/04/18 11:50:24 oes Exp $</pubdate>

<authorgroup>
 <author>
  <affiliation>
   <orgname>By: Privoxy Developers</orgname>
   </affiliation>
 </author>
</authorgroup>

<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 user manual gives users information on how to install, configure and use
  <ulink
  url="http://www.privoxy.org/"><application>Privoxy</application></ulink>.
  </para>

<!-- Include privoxy.sgml boilerplate: -->
 &p-intro;
<!-- end privoxy.sgml -->

 <para>
  You can find the latest version of the user manual at  <ulink
  url="http://www.privoxy.org/user-manual/">http://www.privoxy.org/user-manual/</ulink>.
  Please see the <ulink url="contact.html">Contact section</ulink> 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 id="intro" label=""><title></title>
<!-- dummy section to force TOC on page by itself -->
<!-- DO NOT REMOVE! please ;) -->
<para> </para>
</sect1>

<!--   ~~~~~       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 version 3.0 is currently nearing
 completion, and includes many significant changes and enhancements over
 earlier versions. The target release date for
 stable v3.0 is <quote>soon</quote> ;-)]]>.
</para>

<![%p-not-stable;[
<!-- include only in non-stable versions -->
<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="newfeatures">
<title>New Features</title>
<para>
 In addition to <application>Internet Junkbuster's</application> traditional
 features of ad and banner blocking and cookie management,
 <application>Privoxy</application> provides new features<![%p-not-stable;[,
 some of them currently under development]]>:
<anchor id="testing"/>
</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>
 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> or simply download <ulink
 url="http://cvs.sourceforge.net/cvstarballs/ijbswa-cvsroot.tar.gz">the nightly CVS
 tarball.</ulink>
</para>

<!-- Include supported.sgml boilerplate -->
 &supported; 
<!-- end boilerplate -->

<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="installation-packages"><title>Binary Packages</title>

<para>
 Note: If you have a previous <application>Junkbuster</application> or
 <application>Privoxy</application> installation on your system, you
 will either need to remove it, or that might be done by the setup 
 procedure. (See below for your platform).
</para>

<para>
 In any case <emphasis>be sure to backup your old configuration
 if it is valuable to you.</emphasis> In that case, also see the
 <link linkend="upgradersnote">note to upgraders</link>.
</para>

<para>
 How to install the binary packages depends on your operating system:
</para>

<!--   ~~~~~       New section      ~~~~~     -->
<sect3 id="installation-pack-rpm"><title>Redhat and SuSE RPMs</title>

<para>
 RPMs can be installed with <literal>rpm -Uvh &lt;name-of-rpm.rpm&gt;</literal>,
 and will use <filename>/etc/privoxy</filename> for configuration files.
</para>

<para>
 Note that if you have a <application>Junkbuster</application> RPM installed
 on your system, you need to remove it first, because the packages conflict.
</para>
</sect3>

<!--   ~~~~~       New section      ~~~~~     -->
<sect3 id="installation-deb"><title>Debian</title>
<para>
 FIXME.
</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.
</para>
</sect3>

<!--   ~~~~~       New section      ~~~~~     -->
<sect3 id="installation-pack-bintgz"><title>Solaris, NetBSD, FreeBSD, 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.
</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.
</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>Max OSX</title>
<para>
 FIXME.
</para>
</sect3>

<!--   ~~~~~       New section      ~~~~~     -->
<sect3 id="installation-amiga"><title>AmigaOS</title>
<para>
 Unpack the <literal>.lha</literal> archive, then FIXME.
</para>
</sect3>
</sect2>

<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="installation-source"><title>Building from Source</title>

<!-- include buildsource.sgml boilerplate: -->
&buildsource;
<!-- end boilerplate -->
</sect2>

</sect1>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->

<sect1 id="quickstart"><title>Quickstart to Using <application>Privoxy</application></title>


<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="upgradersnote">
<title>Note to Upgraders</title>
<para>
 There are very significant changes from older versions of 
 <application>Junkbuster</application> to the current
 <application>Privoxy</application>. Configuration is substantially 
 changed. <application>Junkbuster 2.0.x</application> and earlier 
 configuration files will not migrate. The functionality of the old
 <filename>blockfile</filename>, <filename>cookiefile</filename> and
 <filename>imagelist</filename>, are now combined into the
 <quote>actions file</quote>  (<filename>default.action</filename>
 for most installations).
</para>
<para>
 A <quote>filter file</quote> (typically <filename>default.filter</filename>)
 is new with <application>Privoxy 2.9.x</application>, and provides some
 of the new  sophistication (explained below). <filename>config</filename> is 
 much the same as before.
</para>
<para>
 If upgrading from a 2.0.x version, you will have to use the new config 
 files, and possibly adapt any personal rules from your older files.
 When porting personal rules over from the old <filename>blockfile</filename>
 to the new actions file, please note that even the pattern syntax has
 changed.
 If upgrading from 2.9.x development versions, it is still recommended 
 to use the new configuration files.
</para>
<para>
 A quick list of things to be aware of before upgrading: 
</para>

<para>
 <itemizedlist>

 <listitem>
  <para>
   The default listening port is now 8118 due to a conflict with another 
   service (NAS).
  </para>
 </listitem>  
 <listitem>
  <para>  
    Some installers may remove earlier versions completely. Save any 
    important configuration files!
  </para>
 </listitem>
 <listitem>
  <para>
   <application>Privoxy</application> is controllable with a web browser 
   at the special URL: <ulink
   url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
   (Shortcut: <ulink url="http://p.p/">http://p.p/</ulink>). Many
   aspects of configuration can be done here, including temporarily disabling
   <application>Privoxy</application>.
  </para>
 </listitem> 
 <listitem>
  <para>
   The primary configuration file for cookie management, ad and banner 
   blocking, and many other aspects of <application>Privoxy</application>
   configuration is <filename>default.action</filename>. It is strongly
   recommended to become familiar with the new actions concept below, 
   before modifying this file.
  </para>
 </listitem> 
  <listitem>
  <para>
<!-- I think it is best to keep this somewhat vague, in case  -->
<!-- the situation changes under our feet. -->   
   Some installers may not automatically start
   <application>Privoxy</application> after installation.
  </para>
 </listitem> 

 </itemizedlist>
</para>

</sect2>

<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="startup">
<title>Starting <application>Privoxy</application></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 proxy. The default is localhost for the proxy address,
 and port 8118 (earlier versions used port 8000). This is the one required 
 configuration that must be done! 
</para>
 
<para> 
 With <application>Netscape</application> (and
 <application>Mozilla</application>), this can be set under <literal>Edit
 -&gt; Preferences -&gt; Advanced -&gt; Proxies -&gt; HTTP Proxy</literal>.
 For <application>Internet Explorer</application>: <literal>Tools -&gt;
 Internet Properties -&gt; Connections -&gt; LAN Setting</literal>. Then,
 check <quote>Use Proxy</quote> and fill in the appropriate info (Address:
 localhost, Port: 8118). Include if HTTPS proxy support too.
</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. You 
 are now ready to start enjoying the benefits of using
 <application>Privoxy</application>.
</para>


<para>
 <application>Privoxy</application> is typically started by specifying the
 main configuration file to be used on the command line. Example Unix startup
 command:
</para>

<para>
 <screen>
 
 # /usr/sbin/privoxy /etc/privoxy/config
 
 </screen>
</para>

<para>
 An init script is provided for SuSE and Redhat.
</para>

<para>
 For for SuSE: <command>rcprivoxy start</command>
</para>

<para>
 For RedHat: <command>/etc/rc.d/init.d/privoxy start</command>
</para>


<para>
 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>. If no file is specified on the
 command line and no default configuration file can be found, 
 <application>Privoxy</application> will fail to start.
</para>


<para>
 The included default configuration files should give a reasonable starting
 point. Most of the per site configuration is done in the
 <quote>actions</quote> 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 that require persistent
 cookies, and add these to <filename>default.action</filename> as needed. By
 default, most of these will be accepted only during the current browser
 session (aka <quote>session cookies</quote>), until you add them to the
 configuration. If you want the browser to handle this instead, you will need
 to edit <filename>default.action</filename> 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 the <literal>+popup</literal> and
 <literal>+filter{popups}</literal> actions), because your favorite shopping,
 banking, or leisure site may need popups. 
</para>

<para>
 <application>Privoxy</application> is HTTP/1.1 compliant,  but not all of
 the optional 1.1 features are as yet supported. 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</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> (as specified in <filename>default.action</filename>) 
 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>edit the actions list</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 <filename>default.action</filename> 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 <ulink
 url="configuration.html#ACTIONSFILE">read more about the actions concept</ulink>
 or even dive deep into the <ulink url="appendix.html#ACTIONSANAT">Appendix
 on actions</ulink>.
</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 
 chapter "Contacting the Developers, .." below.
</para>

</sect2>


<!--   ~~~~~       New section      ~~~~~     -->
<sect2>
<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 a 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, 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>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.
  </para>
 </listitem> 

 </itemizedlist>
</para>

</sect2>

</sect1>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->
<sect1 id="configuration"><title><application>Privoxy</application> 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 <application>Privoxy</application> 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>

<para>
 <screen>

Please choose from the following options:

    * Privoxy main page
    * Show information about the current configuration
    * Show the source code version numbers
    * Show the request headers.
    * Show which actions apply to a URL and why
    * Toggle Privoxy on or off
    * Edit the actions list

 </screen>
</para>

<para>
 This should be self-explanatory. Note the last item is an editor for the
 <quote>actions list</quote>, which is where much of 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 filtering is disabled. There
 is even a toggle Bookmarklet offered, so that you can toggle
 <application>Privoxy</application> with one click from your browser.

</para>

</sect2>

<!--  ~  End section  ~  -->




<!--   ~~~~~       New section      ~~~~~     -->

<sect2>
<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 possibly
 aggressive by some standards. For the time being, there are only three
 default configuration files (this may change in time):
</para>

<para>
 <itemizedlist>

  <listitem>
   <para>
     The main configuration file is named <filename>config</filename>
     on Linux, Unix, BSD, OS/2, and AmigaOS and <filename>config.txt</filename>
     on Windows.
   </para>
  </listitem> 

  <listitem>
   <para>
    <filename>default.action</filename> (the actions file) is used to define
    which of a set of various <quote>actions</quote> relating to images, banners, 
    pop-ups, access restrictions, banners and cookies are to be applied where.
    There is a web based editor for this file that can be accessed at <ulink
    url="http://config.privoxy.org/edit-actions/">http://config.privoxy.org/edit-actions/</ulink>
    (Shortcut: <ulink url="http://p.p/edit-actions/">http://p.p/edit-actions/</ulink>).
    (Other actions files are included as well with differing levels of filtering 
    and blocking, e.g. <filename>basic.action</filename>.)
   </para>
  </listitem> 

  <listitem>
   <para>
    <filename>default.filter</filename> (the filter file) 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 file.
   </para>
  </listitem> 

 </itemizedlist>
</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.
</para>

<para>
 <filename>default.action</filename> and <filename>default.filter</filename> 
 can use Perl style regular expressions 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>


<!--   ~~~~~       New section      ~~~~~     -->

<sect2>
<title>The Main Configuration File</title>
<para>
 Again, the main configuration file is named <filename>config</filename> on
 Linux/Unix/BSD and OS/2, and <filename>config.txt</filename> on Windows.
 Configuration lines consist of an initial keyword followed by a list of
 values, all separated by whitespace (any number of spaces or tabs). For
 example:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>confdir /etc/privoxy</emphasis>
   </literallayout>
  </msgtext>
 </literal> 
</para>

<para>
 Assigns the value <literal>/etc/privoxy</literal> to the option
 <literal>confdir</literal> and thus indicates that the configuration
 directory is named <quote>/etc/privoxy/</quote>.
</para>

<para>
 All options in the config file except for <literal>confdir</literal> and
 <literal>logdir</literal> are optional. Watch out in the below description
 for what happens if you leave them unset.
</para>

<para>
 The main config file controls all aspects of <application>Privoxy</application>'s
 operation that are not location dependent (i.e. they apply universally, no matter
 where you may be surfing).
</para>


<!--   ~~~~~       New section      ~~~~~     -->

<sect3>
<title>Configuration and Log File Locations</title>

<para>
 <application>Privoxy</application> can (and normally does) use a number of
 other files for additional configuration and logging.
 This section of the configuration file tells <application>Privoxy</application>
 where to find those other files. 
</para>


<sect4><title>confdir</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>The directory where the other configuration files are located</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>Path name</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>/etc/privoxy (Unix) <emphasis>or</emphasis> <application>Privoxy</application> installation dir (Windows) </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para><emphasis>Mandatory</emphasis></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    No trailing <quote><literal>/</literal></quote>, please
   </para>
   <para>
    When development goes modular and multi-user, the blocker, filter, and
    per-user config will be stored in subdirectories of <quote>confdir</quote>.
    For now, the configuration directory structure is flat, except for 
    <filename>confdir/templates</filename>, where the HTML templates for CGI 
    output reside (e.g. <application>Privoxy's</application> 404 error page). 
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>


<sect4><title>logdir</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    The directory where all logging takes place (i.e. where <filename>logfile</filename> and 
    <filename>jarfile</filename> are located) 
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>Path name</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>/var/log/privoxy (Unix) <emphasis>or</emphasis> <application>Privoxy</application> installation dir (Windows) </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para><emphasis>Mandatory</emphasis></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    No trailing <quote><literal>/</literal></quote>, please
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4><title>actionsfile</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    The actions file to use
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>File name, relative to <literal>confdir</literal></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>default.action (Unix) <emphasis>or</emphasis> default.action.txt (Windows)</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    No action is taken at all. Simple neutral proxying. 
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    There is no point in using <application>Privoxy</application> without
    an actions file. There are three different actions files included in the
    distribution, with varying degrees of aggressiveness: 
    <filename>default.action</filename>, <filename>intermediate.action</filename> and
    <filename>advanced.action</filename>.
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4><title>filterfile</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    The filter file to use
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>File name, relative to <literal>confdir</literal></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>default.filter (Unix) <emphasis>or</emphasis> default.filter.txt (Windows)</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    No textual content filtering takes place, i.e. all
    <literal>+filter{<replaceable class="parameter">name</replaceable>}</literal>
    actions in the actions file are turned off
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    The <quote>default.filter</quote> file contains content modification rules 
    that use <quote>regular expressions</quote>. These rules permit powerful
    changes on the content of Web pages, e.g., you could disable your favorite
    JavaScript annoyances, re-write the actual displayed text, or just have some
    fun replacing <quote>Microsoft</quote> with <quote>MicroSuck</quote> wherever
    it appears on a Web page.
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4><title>logfile</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    The log file to use
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>File name, relative to <literal>logdir</literal></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>logfile (Unix) <emphasis>or</emphasis> privoxy.log (Windows)</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    No log file is used, all log messages go to the console (<literal>stderr</literal>).
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    The windows version will additionally log to the console.
   </para>
   <para>
    The logfile is where all logging and error messages are written. The level
    of detail and number of messages are set with the <literal>debug</literal>
    option (see below). The logfile can be useful for tracking down a problem with
    <application>Privoxy</application> (e.g., it's not blocking an ad you
    think it should block) but in most cases you probably will never look at it.
   </para>
   <para>
    Your logfile will grow indefinitely, and you will probably want to
    periodically remove it.  On Unix systems, you can do this with a cron job
    (see <quote>man cron</quote>). For Redhat, a <command>logrotate</command> 
    script has been included.
   </para> 
   <para>
    On SuSE Linux systems, you can place a line like <quote>/var/log/privoxy.*
    +1024k 644 nobody.nogroup</quote> in <filename>/etc/logfiles</filename>, with
    the effect that cron.daily will automatically archive, gzip, and empty the
    log, when it exceeds 1M size.
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4><title>jarfile</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    The file to store intercepted cookies in
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>File name, relative to <literal>logdir</literal></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>jarfile (Unix) <emphasis>or</emphasis> privoxy.jar (Windows)</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    Intercepted cookies are not stored at all.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    The jarfile may grow to ridiculous sizes over time.
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4><title>trustfile</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    The trust file to use
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>File name, relative to <literal>confdir</literal></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para><emphasis>Unset (commented out)</emphasis>. When activated: trust (Unix) <emphasis>or</emphasis> trust.txt (Windows)</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    The whole trust mechanism is turned off.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    The trust mechanism is an experimental feature for building white-lists and should
    be used with care. It is <emphasis>NOT</emphasis> recommended for the casual user.
   </para>
   <para>
    If you specify a trust file, <application>Privoxy</application> will only allow
    access to sites that are named in the trustfile. 
    You can also mark sites as trusted referrers (with <literal>+</literal>), with
    the effect that access to untrusted sites will be granted, if a link from a
    trusted referrer was used.
    The link target will then be added to the <quote>trustfile</quote>.
    Possible applications include limiting Internet access for children.
   </para>
   <para>
    If you use <literal>+</literal> operator in the trust file, it may grow considerably over time.
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

</sect3>

<!--  ~  End section  ~  -->



<!--   ~~~~~       New section      ~~~~~     -->

<sect3>
<title>Local Set-up Documentation</title>

  <para>
    If you intend to operate <application>Privoxy</application> for more users
    that just yourself, it might be a good idea to let them know how to reach
    you, what you block and why you do that, your policies etc.
   </para>

<sect4><title>trust-info-url</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    A URL to be displayed in the error page that users will see if access to an untrusted page is denied.    
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>URL</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>Two example URL are provided</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    No links are displayed on the "untrusted" error page.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    The value of this option only matters if the experimental trust mechanism has been
    activated. (See <literal>trustfile</literal> above.)
   </para>
   <para>
    If you use the trust mechanism, it is a good idea to write up some on-line
    documentation about your trust policy and to specify the URL(s) here.
    Use multiple times for multiple URLs.
   </para>
   <para>
    The URL(s) should be added to the trustfile as well, so users don't end up
    locked out from the information on why they were locked out in the first place!
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4><title>admin-address</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    An email address to reach the proxy administrator.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>Email address</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para><emphasis>Unset</emphasis></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    No email address is displayed on error pages and the CGI user interface.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
    <para>
    If both <literal>admin-address</literal> and <literal>proxy-info-url</literal>
    are unset, the whole "Local Privoxy Support" box on all generated pages will
    not be shown.
   </para>  
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4><title>proxy-info-url</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    A URL to documentation about the local <application>Privoxy</application> setup,
    configuration or policies.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>URL</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para><emphasis>Unset</emphasis></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    No link to local documentation is displayed on error pages and the CGI user interface.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    If both <literal>admin-address</literal> and <literal>proxy-info-url</literal>
    are unset, the whole "Local Privoxy Support" box on all generated pages will
    not be shown.
   </para>  
   <para>
    This URL shouldn't be blocked ;-)
   </para> 
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

</sect3>
<!--  ~  End section  ~  -->

<!--   ~~~~~       New section      ~~~~~     -->

<sect3>
<title>Debugging</title>

 <para>
  These options are mainly useful when tracing a problem.
  Note that you might also want to invoke
  <application>Privoxy</application> with the <literal>--no-daemon</literal>
  command line option when debugging.
 </para>

<sect4><title>debug</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    Key values that determine what information gets logged.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>Integer values</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>12289 (i.e.: URLs plus informational and warning messages)</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    Nothing gets logged.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    The available debug levels are:
   </para>
   <para>
    <programlisting>
  debug         1 # show each GET/POST/CONNECT request
  debug         2 # show each connection status
  debug         4 # show I/O status
  debug         8 # show header parsing
  debug        16 # log all data into the logfile
  debug        32 # debug force feature
  debug        64 # debug regular expression filter 
  debug       128 # debug fast redirects
  debug       256 # debug GIF de-animation
  debug       512 # Common Log Format
  debug      1024 # debug kill pop-ups
  debug      4096 # Startup banner and warnings.
  debug      8192 # Non-fatal errors
    </programlisting>
   </para>
   <para>
    To select multiple debug levels, you can either add them or use
    multiple <literal>debug</literal> lines.
   </para>
   <para>
    A debug level of 1 is informative because it will show you each request
    as it happens. <emphasis>1, 4096 and 8192 are highly recommended</emphasis>
    so that you will notice when things go wrong. The other levels are probably
    only of interest if you are hunting down a specific problem. They can produce
    a hell of an output (especially 16).
    <!-- LOL -->
   </para>
   <para>
    The reporting of <emphasis>fatal</emphasis> errors (i.e. ones which crash 
    <application>Privoxy</application>) is always on and cannot be disabled.
   </para>
   <para>
    If you want to use CLF (Common Log Format), you should set <quote>debug
    512</quote> <emphasis>ONLY</emphasis> and not enable anything else.
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4><title>single-threaded</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    Whether to run only one server thread
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para><emphasis>None</emphasis></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para><emphasis>Unset</emphasis></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    Multi-threaded (or, where unavailable: forked) operation, i.e. the ability to
    serve multiple requests simultaneously.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    This option is only there for debug purposes and you should never
    need to use it. <emphasis>It will drastically reduce performance.</emphasis>
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

</sect3>

<!--   ~~~~~       New section      ~~~~~     -->

<sect3>
<title>Access Control and Security</title>

 <para>
  This section of the config file controls the security-relevant aspects
  of <application>Privoxy</application>'s configuration.
 </para>

<sect4><title>listen-address</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    The IP address and TCP port on which <application>Privoxy</application> will
    listen for client requests.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>[<replaceable class="parameter">IP-Address</replaceable>]:<replaceable class="parameter">Port</replaceable></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>localhost:8118</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    Bind to localhost (127.0.0.1), port 8118. This is suitable and recommended for
    home users who run <application>Privoxy</application> on the same machine as
    their browser.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    You will need to configure your browser(s) to this proxy address and port.
   </para>
   <para>
    If you already have another service running on port 8118, or if you want to
    serve requests from other machines (e.g. on your local network) as well, you
    will need to override the default.
   </para>
   <para>
    If you leave out the IP address, <application>Privoxy</application> will
    bind to all interfaces (addresses) on your machine and may become reachable
    from the Internet. In that case, consider using access control lists (acl's)
    (see <quote>ACLs</quote> below), or a firewall.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Example:</term>
  <listitem>
   <para>
     Suppose you are running <application>Privoxy</application> on
     a machine which has the address 192.168.0.1 on your local private network
     (192.168.0.0) and has another outside connection with a different address.
     You want it to serve requests from inside only:
   </para>
   <para>
    <programlisting>
  listen-address  192.168.0.1:8118
    </programlisting>
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4><title>toggle</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    Initial state of "toggle" status
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>1 or 0</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>1</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    Act as if toggled on
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    If set to 0, <application>Privoxy</application> will start in
    <quote>toggled off</quote> mode, i.e. behave like a normal, content-neutral
    proxy. See <literal>enable-remote-toggle</literal>
    below. This is not really useful anymore, since toggling is much easier
    via <ulink url="http://config.privoxy.org/toggle">the web
    interface</ulink> then via editing the <filename>conf</filename> file.
   </para>
   <para>
    The windows version will only display the toggle icon in the system tray
    if this option is present.
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>


<sect4><title>enable-remote-toggle</title>
<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    Whether or not the <ulink url="http://config.privoxy.org/toggle">web-based toggle
    feature</ulink> may be used
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>0 or 1</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>1</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    The web-based toggle feature is disabled.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    When toggled off, <application>Privoxy</application> acts like a normal,
    content-neutral proxy, i.e. it acts as if none of the actions applied to
    any URL.
   </para>
   <para>
    For the time being, access to the toggle feature can <emphasis>not</emphasis> be
    controlled separately by <quote>ACLs</quote> or HTTP authentication,
    so that everybody who can access <application>Privoxy</application> (see
    <quote>ACLs</quote> and <literal>listen-address</literal> above) can
    toggle it for all users. So this option is <emphasis>not recommended</emphasis>
    for multi-user environments with untrusted users.
   </para>
   <para>
    Note that you must have compiled <application>Privoxy</application> with
    support for this feature, otherwise this option has no effect. 
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>


<sect4><title>enable-edit-actions</title>
<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    Whether or not the <ulink url="http://config.privoxy.org/edit-actions">web-based actions
    file editor</ulink> may be used
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>0 or 1</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>1</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    The web-based actions file editor is disabled.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    For the time being, access to the editor can <emphasis>not</emphasis> be
    controlled separately by <quote>ACLs</quote> or HTTP authentication,
    so that everybody who can access <application>Privoxy</application> (see
    <quote>ACLs</quote> and <literal>listen-address</literal> above) can
    modify its configuration for all users. So this option is <emphasis>not
    recommended</emphasis> for multi-user environments with untrusted users.
   </para>
   <para>
    Note that you must have compiled <application>Privoxy</application> with
    support for this feature, otherwise this option has no effect. 
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4><title>ACLs: permit-access and deny-access</title>
<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    Who can access what.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>
    <replaceable class="parameter">src_addr</replaceable>[/<replaceable class="parameter">src_masklen</replaceable>]
    [<replaceable class="parameter">dst_addr</replaceable>[/<replaceable class="parameter">dst_masklen</replaceable>]]
   </para>
   <para>
    Where <replaceable class="parameter">src_addr</replaceable> and 
   <replaceable class="parameter">dst_addr</replaceable> are IP addresses in dotted decimal notation or valid
    DNS names, and <replaceable class="parameter">src_masklen</replaceable> and
    <replaceable class="parameter">dst_masklen</replaceable> are subnet masks in CIDR notation, i.e. integer
    values from 2 to 30 representing the length (in bits) of the network address. The masks and the whole
    destination part are optional.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para><emphasis>Unset</emphasis></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    Don't restrict access further than implied by <literal>listen-address</literal>
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    Access controls are included at the request of ISPs and systems
    administrators, and <emphasis>are not usually needed by individual users</emphasis>.
    For a typical home user, it will normally suffice to ensure that 
    <application>Privoxy</application> only listens on the localhost or internal (home)
    network address by means of the <literal>listen-address</literal> option.
   </para>
   <para>
    Please see the warnings in the FAQ that this proxy is not intended to be a substitute
    for a firewall or to encourage anyone to defer addressing basic security
    weaknesses.
   </para>
   <para>
    Multiple ACL lines are OK.
    If any ACLs are specified, then the <application>Privoxy</application>
    talks only to IP addresses that match at least one <literal>permit-access</literal> line
    and don't match any subsequent <literal>deny-access</literal> line. In other words, the
    last match wins, with the default being <literal>deny-access</literal>.
   </para>
   <para>
    If <application>Privoxy</application> is using a forwarder (see <literal>forward</literal> below)
    for a particular destination URL, the <replaceable class="parameter">dst_addr</replaceable>
    that is examined is the address of the forwarder and <emphasis>NOT</emphasis> the address
    of the ultimate target. This is necessary because it may be impossible for the local
    <application>Privoxy</application> to determine the IP address of the
    ultimate target (that's often what gateways are used for).
   </para>
   <para>
    You should prefer using IP addresses over DNS names, because the address lookups take
    time. All DNS names must resolve! You can <emphasis>not</emphasis> use domain patterns
    like <quote>*.org</quote> or partial domain names. If a DNS name resolves to multiple
    IP addresses, only the first one is used.
   </para>
   <para>
    Denying access to particular sites by ACL may have undesired side effects
    if the site in question is hosted on a machine which also hosts other sites.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Examples:</term>
  <listitem>
   <para>
    Explicitly define the default behavior if no ACL and
    <literal>listen-address</literal> are set: <quote>localhost</quote>
    is OK. The absence of a <replaceable class="parameter">dst_addr</replaceable> implies that
    <emphasis>all</emphasis> destination addresses are OK:
   </para>
   <para>
    <screen>
  permit-access  localhost
    </screen>
   </para>
   <para>
    Allow any host on the same class C subnet as www.privoxy.org access to
    nothing but www.example.com:
   </para>
   <para>
    <screen>
  permit-access  www.privoxy.org/24 www.example.com/32
    </screen>
   </para>
   <para>
    Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere,
    with the exception that 192.168.45.73 may not access www.dirty-stuff.example.com:
   </para>
   <para>
    <screen>
  permit-access  192.168.45.64/26
  deny-access    192.168.45.73    www.dirty-stuff.example.com
    </screen>
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4><title>buffer-limit</title>

<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    Maximum size of the buffer for content filtering.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>Size in Kbytes</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para>4096</para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    Use a 4MB (4096 KB) limit.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    For content filtering, i.e. the <literal>+filter</literal> and
    <literal>+deanimate-gif</literal> actions, it is necessary that 
    <application>Privoxy</application> buffers the entire document body.
    This can be potentially dangerous, since a server could just keep sending
    data indefinitely and wait for your RAM to exhaust -- with nasty consequences.
    Hence this option.
   </para>
   <para>
    When a document buffer size reaches the <literal>buffer-limit</literal>, it is
    flushed to the client unfiltered and no further attempt to
    filter the rest of the document is made. Remember that there may be multiple threads
    running, which might require up to <literal>buffer-limit</literal> Kbytes
    <emphasis>each</emphasis>, unless you have enabled <quote>single-threaded</quote>
    above.
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

</sect3>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->

<sect3 id="forwarding">
<title>Forwarding</title>

<para>
 This feature allows routing of HTTP requests through a chain of
 multiple proxies.
 It can be used to better protect privacy and confidentiality when
 accessing specific domains by routing requests to those domains
 through an anonymous public proxy (see e.g. <ulink
 url="http://www.multiproxy.org/anon_list.htm">http://www.multiproxy.org/anon_list.htm</ulink>)
 Or to use a caching proxy to speed up browsing. Or chaining to a parent
 proxy may be necessary because the machine that <application>Privoxy</application>
 runs on has no direct Internet access.
</para>

<para>
 Also specified here are SOCKS proxies. <application>Privoxy</application>
 supports the SOCKS 4 and SOCKS 4A protocols.
</para>

<sect4><title>forward</title>
<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    To which parent HTTP proxy specific requests should be routed.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>
    <replaceable class="parameter">target_domain</replaceable>[:<replaceable class="parameter">port</replaceable>]
    <replaceable class="parameter">http_parent</replaceable>[/<replaceable class="parameter">port</replaceable>]
   </para>
   <para>
    Where <replaceable class="parameter">target_domain</replaceable> is a domain name pattern (see the
    chapter on domain matching in the actions file),
    <replaceable class="parameter">http_parent</replaceable> is the address of the parent HTTP proxy
    as an IP addresses in dotted decimal notation or as a valid DNS name (or <quote>.</quote> to denote
    <quote>no forwarding</quote>, and the optional 
    <replaceable class="parameter">port</replaceable> parameters are TCP ports, i.e. integer
    values from 1 to 64535
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para><emphasis>Unset</emphasis></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    Don't use parent HTTP proxies.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    If <replaceable class="parameter">http_parent</replaceable> is <quote>.</quote>, then requests are not
    forwarded to another HTTP proxy but are made directly to the web servers.
   </para>
   <para>
    Multiple lines are OK, they are checked in sequence, and the last match wins.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Examples:</term>
  <listitem>
   <para>
    Everything goes to an example anonymizing proxy, except SSL on port 443 (which it doesn't handle):
   </para>
   <para>
    <screen>
  forward   .*     anon-proxy.example.org:8080
  forward   :443   .
    </screen>
   </para>
   <para>
    Everything goes to our example ISP's caching proxy, except for requests
    to that ISP's sites:
   </para>
   <para>
    <screen>
  forward   .*.                caching-proxy.example-isp.net:8000
  forward   .example-isp.net   .
    </screen>
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4><title>forward-socks4 and forward-socks4a</title>
<variablelist>
 <varlistentry>
  <term>Specifies:</term>
  <listitem>
   <para>
    Through which SOCKS proxy (and to which parent HTTP proxy) specific requests should be routed.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Type of value:</term>
  <listitem>
   <para>
    <replaceable class="parameter">target_domain</replaceable>[:<replaceable class="parameter">port</replaceable>]
    <replaceable class="parameter">socks_proxy</replaceable>[/<replaceable class="parameter">port</replaceable>]
    <replaceable class="parameter">http_parent</replaceable>[/<replaceable class="parameter">port</replaceable>]
   </para>
   <para>
    Where <replaceable class="parameter">target_domain</replaceable> is a domain name pattern (see the
    chapter on domain matching in the actions file),
    <replaceable class="parameter">http_parent</replaceable> and <replaceable class="parameter">socks_proxy</replaceable>
    are IP addresses in dotted decimal notation or valid DNS names (<replaceable class="parameter">http_parent</replaceable>
    may be <quote>.</quote> to denote <quote>no HTTP forwarding</quote>), and the optional 
    <replaceable class="parameter">port</replaceable> parameters are TCP ports, i.e. integer values from 1 to 64535
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Default value:</term>
  <listitem>
   <para><emphasis>Unset</emphasis></para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Effect if unset:</term>
  <listitem>
   <para>
    Don't use SOCKS proxies.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Notes:</term>
  <listitem>
   <para>
    Multiple lines are OK, they are checked in sequence, and the last match wins.
   </para>
   <para>
    The difference between <literal>forward-socks4</literal> and <literal>forward-socks4a</literal>
    is that in the SOCKS 4A protocol, the DNS resolution of the target hostname happens on the SOCKS
    server, while in SOCKS 4 it happens locally.
   </para>
   <para>
    If <replaceable class="parameter">http_parent</replaceable> is <quote>.</quote>, then requests are not
    forwarded to another HTTP proxy but are made (HTTP-wise) directly to the web servers, albeit through
    a SOCKS proxy.
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term>Examples:</term>
  <listitem>
   <para>
     From the company example.com, direct connections are made to all
     <quote>internal</quote> domains, but everything outbound goes through
     their ISP's proxy by way of example.com's corporate SOCKS 4A gateway to
     the Internet.
   </para>
   <para>
    <screen>
  forward-socks4a   .*.            socks-gw.example.com:1080  www-cache.example-isp.net:8080
  forward           .example.com   .
    </screen>
   </para>
   <para>
    A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent looks like this:
   </para>
   <para>
    <screen>
  forward-socks4   .*.            socks-gw.example.com:1080  .
    </screen>
   </para>
  </listitem>
 </varlistentry>
</variablelist>
</sect4>

<sect4><title>Advanced Forwarding Examples</title>

<para>
 If you have links to multiple ISPs that provide various special content 
 only to their subscribers, you can configure multiple <application>Privoxies</application>
 which have connections to the respective ISPs to act as forwarders to each other, so that
 <emphasis>your</emphasis> users can see the internal content of all ISPs.
</para>

<para>
 Assume that host-a has a PPP connection to isp-a.net. And host-b has a PPP connection to
 isp-b.net. Both run <application>Privoxy</application>. Their forwarding
 configuration can look like this:
</para>

<para>
 host-a:
</para>

<para>
 <screen>
  forward    .*.         .
  forward    .isp-b.net  host-b:8118
 </screen>
</para>

<para>
 host-b:
</para>

<para>
 <screen>
  forward    .*.         .
  forward    .isp-a.net  host-a:8118
 </screen>
</para>

<para>
 Now, your users can set their browser's proxy to use either
 host-a or host-b and be able to browse the internal content
 of both isp-a and isp-b.
</para>

<para>
 If you intend to chain <application>Privoxy</application> and 
 <application>squid</application> locally, then chain as 
 <literal>browser -> squid -> privoxy</literal> is the recommended way. 
</para>

<para>
 Assuming that <application>Privoxy</application> and <application>squid</application>
 run on the same box, your squid configuration could then look like this:
</para>

<para>
 <screen>
  # Define Privoxy as parent proxy (without ICP) 
  cache_peer 127.0.0.1 parent 8118 7 no-query 

  # Define ACL for protocol FTP 
  acl ftp proto FTP 

  # Do not forward FTP requests to Privoxy
  always_direct allow ftp 

  # Forward all the rest to Privoxy
  never_direct allow all 
 </screen>
</para>

<para>
 You would then need to change your browser's proxy settings to <application>squid</application>'s address and port.
 Squid normally uses port 3128. If unsure consult <literal>http_port</literal> in <filename>squid.conf</filename>.
</para>

</sect4>

</sect3>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->

<sect3>
<title>Windows GUI Options</title>
<!--
Removed references to Win32. HB 09/23/01
-->
<para>
 <application>Privoxy</application> has a number of options specific to the
 Windows GUI interface:
</para>

<para>
 If <quote>activity-animation</quote> is set to 1, the
 <application>Privoxy</application> icon will animate when
 <quote>Privoxy</quote> is active. To turn off, set to 0.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>activity-animation   1</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 If <quote>log-messages</quote> is set to 1,
 <application>Privoxy</application> will log messages to the console
 window:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>log-messages       1</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para> 
 If <quote>log-buffer-size</quote> is set to 1, the size of the log buffer,
 i.e. the amount of memory used for the log messages displayed in the
 console window, will be limited to <quote>log-max-lines</quote> (see below).
</para>

<para>
 Warning: Setting this to 0 will result in the buffer to grow infinitely and
 eat up all your memory!
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>log-buffer-size      1</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 <application>log-max-lines</application> is the maximum number of lines held
 in the log buffer. See above.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>log-max-lines      200</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 If <quote>log-highlight-messages</quote> is set to 1,
 <application>Privoxy</application> will highlight portions of the log
 messages with a bold-faced font:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>log-highlight-messages   1</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 The font used in the console window:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>log-font-name        Comic Sans MS</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Font size used in the console window:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>log-font-size        8</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>  
 <quote>show-on-task-bar</quote> controls whether or not
 <application>Privoxy</application> will appear as a button on the Task bar
 when minimized:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>show-on-task-bar     0</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 If <quote>close-button-minimizes</quote> is set to 1, the Windows close
 button will minimize <application>Privoxy</application> instead of closing
 the program (close with the exit option on the File menu).
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>close-button-minimizes  1</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 The <quote>hide-console</quote> option is specific to the MS-Win console
 version of <application>Privoxy</application>. If this option is used,
 <application>Privoxy</application> will disconnect from and hide  the
 command console.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  #hide-console
   </literallayout>
  </msgtext> 
 </literal>
</para>

</sect3>
</sect2>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="actionsfile">
<title>The Actions File</title>

<para>
 The actions file (<filename>default.action</filename>, formerly:
 <filename>actionsfile</filename> or <filename>ijb.action</filename>) is used
 to define what actions <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 on which sites (or even parts
 thereof).
</para>

<para> 
 Anything you want can blocked, including ads, banners, or just some obnoxious
 URL that 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, JavaScripts tamed, user-tracking fooled, and much more.
 See below for a complete list of available actions.
</para>

<!--   ~~~~~       New section      ~~~~~     -->
<sect3>
<title>Finding the Right Mix</title>
<para>
 Note that some actions like cookie suppression or script disabling may
 render some sites unusable, which rely on these techniques to work properly.
 Finding the right mix of actions is not easy and certainly a matter of personal
 taste. 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 kill popup windows per default, you'll
 have to make exceptions from that rule for sites that you regularly use
 and that require popups for actually useful content, 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 file. 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).
</para>
</sect3>

<!--   ~~~~~       New section      ~~~~~     -->
<sect3>
<title>How to Edit</title>
<para>
 The easiest way to edit the <quote>actions</quote> file is with a browser by
 using our browser-based editor, which is available at <ulink
 url="http://config.privoxy.org/edit-actions">http://config.privoxy.org/edit-actions</ulink>.
</para>

<para>
 If you prefer plain text editing to GUIs, you can of course also directly edit the
 <filename>default.action</filename> file.
</para>
</sect3>


<sect3>
<title>How Actions are Applied to URLs</title>
<para>
 The actions file is divided into sections. There are special sections,
 like the alias 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 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 patterns in this file. Every time it matches, the list of
 applicable actions for the URL is incrementally updated, using the heading
 of the section in which the pattern is located. If multiple matches for
 the same URL set the same action differently, the last match wins.
</para>

<para>
 You can trace this process by visiting <ulink
 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>.
</para>

<para>
 More detail on this is provided in the Appendix, <link linkend="ACTIONSANAT">
 Anatomy of an Action</link>.
</para>
</sect3>

<!--   ~~~~~       New section      ~~~~~     -->
<sect3>
<title>Patterns</title>
<para>
 Generally, a 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 pattern <literal>/</literal> matches all URLs).
</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.
   </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 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.
   </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>.
   </para>
  </listitem>
 </varlistentry>
</variablelist>

<sect4><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 that <emphasis>ENDS</emphasis> in
    <literal>.example.com</literal>
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term><literal>www.</literal></term>
  <listitem>
   <para>
    matches any domain that <emphasis>STARTS</emphasis> with
    <literal>www.</literal>
   </para>
  </listitem>
 </varlistentry>
 <varlistentry>
  <term><literal>.example.</literal></term>
  <listitem>
   <para>
    matches any domain that <emphasis>CONTAINS</emphasis> <literal>.example.</literal>
    (Correctly speaking: It matches any FQDN that contains <literal>example</literal> as a domain.)
   </para>
  </listitem>
 </varlistentry>
</variablelist>

<para>
 Additionally, there are wild-cards that you can use in the domain names
 themselves. They work pretty similar to shell wild-cards: <quote>*</quote>
 stands for zero or more arbitrary characters, <quote>?</quote> stands for
 any single character, you can define character classes in square
 brackets and all of that 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>

</sect4>

<sect4><title>The Path Pattern</title>

<para>
 <application>Privoxy</application> uses Perl compatible regular expressions
 (through the <ulink url="http://www.pcre.org/">PCRE</ulink> library) for
 matching the path.
</para>

<para>
 There is an <link linkend="regex">Appendix</link> with a brief quick-start into regular
 expressions, and full (very technical) documentation on PCRE regex syntax is available on-line
 at <ulink url="http://www.pcre.org/man.txt">http://www.pcre.org/man.txt</ulink>.
 You might also find the Perl man page on regular expressions (<literal>man perlre</literal>)
 useful, which is available on-line at <ulink
 url="http://www.perldoc.com/perl5.6/pod/perlre.html">http://www.perldoc.com/perl5.6/pod/perlre.html</ulink>.
</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>.
</para>

<para>
 Please also note that matching in the path is case
 <emphasis>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>
</sect4>

</sect3>

<!--  ~  End section  ~  -->



<!--   ~~~~~       New section      ~~~~~     -->

<sect3>
<title>Actions</title>
<para>
 Actions are enabled if preceded with a <quote>+</quote>, and disabled if 
 preceded with a <quote>-</quote>. Actions are invoked by enclosing the 
 action name in curly braces (e.g. {+some_action}), followed by a list of 
 URLs to which the action applies. There are three classes of actions:
</para>

<para>
 <itemizedlist>

 <listitem>
  <para>  
   Boolean (e.g. <quote>+/-block</quote>):
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>{+name}</emphasis>        # enable this action
  <emphasis>{-name}</emphasis>        # disable this action
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>


 <listitem>
  <para>  
   parameterized (e.g. <quote>+/-hide-user-agent</quote>):
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>{+name{param}}</emphasis>  # enable action and set parameter to <quote>param</quote>
  <emphasis>{-name}</emphasis>         # disable action
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>
 
 <listitem>
  <para>  
   Multi-value (e.g. <quote>{+/-add-header{Name: value}}</quote>, <quote>{+/-wafer{name=value}}</quote>):
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>{+name{param}}</emphasis>   # enable action and add parameter <quote>param</quote>
  <emphasis>{-name{param}}</emphasis>   # remove the parameter <quote>param</quote>
  <emphasis>{-name}</emphasis>          # disable this action totally
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>

 </itemizedlist>
</para>

<para>
 If nothing is specified in this file, no <quote>actions</quote> are taken.
 So in this case <application>Privoxy</application> would just be a
 normal, non-blocking, non-anonymizing proxy. You must specifically
 enable the privacy and blocking features you need (although the 
 provided default <filename>default.action</filename> file will 
 give a good starting point).
</para>

<para>
 Later defined actions always over-ride earlier ones.  So exceptions 
 to any rules you make, should come in the latter part of the file. For
 multi-valued actions, the actions are applied in the order they are
 specified.
</para>

<para>
 The list of valid <application>Privoxy</application> <quote>actions</quote> are:
</para>

<para>
 <itemizedlist>
 
 <listitem>
  <para>  
   Add the specified HTTP header, which is not checked for validity.
   You may specify this many times to specify many different headers:
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+add-header{Name: value}</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>
 
 
 <listitem>
  <para>  
   Block this URL totally. In a default installation, a <quote>blocked</quote>
   URL will result in bright red banner that says <quote>BLOCKED</quote>, 
   with a reason why it is being blocked, and an option to see it anyway.
   The page displayed for this is the <quote>blocked</quote> template 
   file.
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+block</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>
 
 
 <listitem>
  <para>  
   De-animate all animated GIF images, i.e. reduce them to their last frame.
   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>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+deanimate-gifs{last}</emphasis>
  <emphasis>+deanimate-gifs{first}</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>
 
 <listitem>
  <para>
   <quote>+downgrade</quote> will downgrade HTTP/1.1 client requests to
   HTTP/1.0 and downgrade the responses as well. Use this action for servers
   that use HTTP/1.1 protocol features that
   <application>Privoxy</application> doesn't handle well yet. HTTP/1.1 
   is only partially implemented. Default is not to downgrade requests.
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+downgrade</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem> 
 
 <listitem>
  <para>  
   Many sites, like yahoo.com, don't just link to other sites. Instead, they
   will link to some script on their own server, giving the destination as a
   parameter, which will then redirect you to the final target. URLs resulting
   from this scheme typically look like:
   <emphasis>http://some.place/some_script?http://some.where-else</emphasis>.
  </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
   ask the server for one redirect after the other. Plus, it feeds the
   advertisers.
  </para>
  <para>
   The <quote>+fast-redirects</quote> option enables interception of these
   types of requests by <application>Privoxy</application>, who will cut off
   all but the last valid URL in the request and send a local redirect back to
   your browser without contacting the intermediate site(s).
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+fast-redirects</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>

 <listitem>
  <para>  
   Apply the filters in the <literal>section_header</literal> 
   section of the <filename>default.filter</filename> file to the site(s).
   <filename>default.filter</filename> sections are grouped according to like
   functionality. <application>Filters</application> can be used to 
   re-write any of the raw page content. This is a potentially a 
   very powerful feature!
  </para> 
   
  <para>
   <literal>
    <msgtext> 
     <literallayout>
 <emphasis>+filter{section_header}</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>

  <para>   
   Filter sections that are pre-defined in the supplied
   <filename>default.filter</filename> include:
  </para>

 <blockquote>
  <simplelist>
   <member>
     <emphasis>html-annoyances</emphasis>:  Get rid of particularly annoying HTML abuse.
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>js-annoyances</emphasis>:    Get rid of particularly annoying JavaScript abuse
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>content-cookies</emphasis>:   Kill cookies that come in the HTML or JS content 
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>popups</emphasis>:         Kill all popups in JS and HTML
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>frameset-borders</emphasis>: Give frames a border and make them resizable 
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>webbugs</emphasis>:          Squish WebBugs (1x1 invisible GIFs used for user tracking)
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>refresh-tags</emphasis>:     Kill automatic refresh tags (for dial-on-demand setups) 
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>fun</emphasis>:              Text replacements  for subversive browsing fun!
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>nimda</emphasis>:            Remove Nimda (virus) code.
   </member>
  </simplelist>
  <simplelist>
   <member>
     <emphasis>banners-by-size</emphasis>:  Kill banners by size (<emphasis>very</emphasis> efficient!)
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>shockwave-flash</emphasis>:   Kill embedded Shockwave Flash objects
   </member>
  </simplelist>
  <simplelist>
   <member>
    <emphasis>crude-parental</emphasis>:   Kill all web pages that contain the words "sex" or "warez"
   </member>
  </simplelist>
 </blockquote>


 <para>
  Note: 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>

 </listitem>

 <listitem>
  <para>  
   Block any existing X-Forwarded-for header, and do not add a new one:
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+hide-forwarded</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>

 <listitem>
  <para>  
   If the browser sends a <quote>From:</quote> header containing your e-mail
   address, this either completely removes the header (<quote>block</quote>), or
   changes it to the specified e-mail address.
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+hide-from{block}</emphasis>
  <emphasis>+hide-from{spam@sittingduck.xqq}</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>
 
 <listitem>
  <para>  
   Don't send the <quote>Referer:</quote> (sic) header to the web site.  You
   can block it, forge a URL to the same server as the request (which is
   preferred because some sites will not send images otherwise) or set it to a
   constant, user defined string of your choice.
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+hide-referer{block}</emphasis>
  <emphasis>+hide-referer{forge}</emphasis>
  <emphasis>+hide-referer{http://nowhere.com}</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>
 
 <listitem>
  <para>  
   Alternative spelling of <quote>+hide-referer</quote>.  It has the same
   parameters, and can be freely mixed with, <quote>+hide-referer</quote>.
   (<quote>referrer</quote> is the correct English spelling, however the HTTP
   specification has a bug - it requires it to be spelled <quote>referer</quote>.) 
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+hide-referrer{...}</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>

 <listitem>
  <para>  
   Change the <quote>User-Agent:</quote> header so web servers can't tell your
   browser type.  Warning! This breaks many web sites.  Specify the
   user-agent value you want. Example, pretend to be using Netscape on
   Linux:
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+hide-user-agent{Mozilla (X11; I; Linux 2.0.32 i586)}</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 <!-- 
  <para>
   Or to identify yourself explicitly as a  <application>Privoxy</application> user:
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+hide-user-agent{Privoxy/1.0}</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
   (Don't change the version number from 1.0 - after all, why tell them?)
  <para>
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+hide-user-agent{browser-type}</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
-->
 </listitem>

 <listitem>
  <para>  
   Treat this URL as an image.  This only matters if it's also <quote>+block</quote>ed,
   in which case a <quote>blocked</quote> image can be sent rather than a HTML page.
   See <quote>+image-blocker{}</quote> below for the control over what is actually sent.
   If you want <emphasis>invisible</emphasis> ads, they should be defined as 
   <emphasis>images</emphasis> and <emphasis>blocked</emphasis>. And also, 
   <quote>image-blocker</quote>  should be set to <quote>blank</quote>. Note you 
   cannot treat HTML pages as images in most cases. For instance, frames 
   require an HTML page to display. So a frame that is an ad, cannot be 
   treated as an image. Forcing an <quote>image</quote> in this 
   situation just will not work.
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+image</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>
 
 <listitem>
  <para> Decides what to do with URLs that end up tagged with <quote>{+block
  +image}</quote>, e.g an advertisement. There are four options.
  <quote>-image-blocker</quote> will send a HTML <quote>blocked</quote> page,
  usually resulting in a <quote>broken image</quote> icon.
<!--   <quote>+image-blocker{logo}</quote> will send a -->
<!--   <application>Privoxy</application> logo -->
<!--   image. -->
<quote>+image-blocker{blank}</quote> will send a 1x1 transparent GIF
image. And finally, <quote>+image-blocker{http://xyz.com}</quote> will send a
HTTP temporary redirect to the specified image. This has the advantage of the
icon being being cached by the browser, which will speed up the display.
<quote>+image-blocker{pattern}</quote> will send a checkerboard type pattern:
<!-- , -->
<!-- which scales better than the logo (which can get blocky if the browser -->
<!-- enlarges it too much). -->
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
<!--   <emphasis>+image-blocker{logo}</emphasis> -->
  <emphasis>+image-blocker{blank}</emphasis>
  <emphasis>+image-blocker{pattern}</emphasis>
  <emphasis>+image-blocker{http://p.p/send-banner}</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>
 
 <listitem>
   <para> 
   By default (i.e. in the absence of a <quote>+limit-connect</quote>
   action), <application>Privoxy</application> will only allow CONNECT
   requests to port 443, which is the standard port for https as a 
   precaution.
  </para>
 
  <para>
   The CONNECT methods exists in HTTP to allow access to secure websites
   (https:// 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 <emphasis>and</emphasis> to the remote proxy.
   This can be a big security hole, since CONNECT-enabled proxies can
   be abused as TCP relays very easily.
  </para>
  
  <para> 
   If you want to allow CONNECT for more ports than this, or want to forbid
   CONNECT altogether, you can specify a comma separated list of ports and
   port ranges (the latter using dashes, with the minimum defaulting to 0 and
   max to 65K):
  </para>

  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+limit-connect{443}                 # This is the default and need no be specified.</emphasis>
  <emphasis>+limit-connect{80,443}              # Ports 80 and 443 are OK.</emphasis>
  <emphasis>+limit-connect{-3, 7, 20-100, 500-} # Port less than 3, 7, 20 to 100</emphasis>
  <emphasis>                                    #and above 500 are OK.</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>

 </listitem> 
 
 <listitem>
  <para>
   <quote>+no-compression</quote> prevents the website from compressing the
   data. Some websites do this, which can be a problem for
   <application>Privoxy</application>, since <quote>+filter</quote>,
   <quote>+no-popup</quote> and <quote>+gif-deanimate</quote> will not work on
   compressed data. This will slow down connections to those websites,
   though. Default is <quote>no-compression</quote> is turned on.
  </para>

  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+nocompression</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem> 
 
 <listitem>
  <para>  
   If the website sets cookies, <quote>no-cookies-keep</quote> will make sure
   they are erased when you exit and restart your web browser. This makes
   profiling cookies useless, but won't break sites which require cookies so
   that you can log in for transactions. Default: on.
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+no-cookies-keep</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>
 
 <listitem>
  <para>  
   Prevent the website from reading cookies:
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+no-cookies-read</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>
 
 <listitem>
  <para>  
   Prevent the website from setting cookies:
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+no-cookies-set</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>
 
 <listitem>
  <para>  
   Filter the website through a built-in filter to disable those obnoxious 
   JavaScript pop-up windows via window.open(), etc. The two alternative
   spellings are equivalent.
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+no-popup</emphasis>
  <emphasis>+no-popups</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>
 
 <listitem>
  <para>  
   This action only applies if you are using a <filename>jarfile</filename>
   for saving cookies. It sends a cookie to every site stating that you do not
   accept any copyright on cookies sent to you, and asking them not to track
   you.  Of course, this is a (relatively) unique header they could use to
   track you.
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+vanilla-wafer</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>
 
 <listitem>
  <para>  
   This allows you to add an arbitrary cookie. It can be specified multiple
   times in order to add as many cookies as you like.
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+wafer{name=value}</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>

 </itemizedlist>
</para>

<para>
 The meaning of any of the above is reversed by preceding the action with a 
 <quote>-</quote>, in place of the <quote>+</quote>.
</para>

<para>
 Some examples:
</para>

<para>
 Turn off cookies by default, then allow a few through for specified sites:
</para>
  
<para>
 <literal>
  <msgtext> 
   <literallayout>
 # Turn off all persistent cookies
 { +no-cookies-read }
 { +no-cookies-set }
 # Allow cookies for this browser session ONLY
 { +no-cookies-keep }

 # Exceptions to the above, sites that benefit from persistent cookies
 { -no-cookies-read }
 { -no-cookies-set }
 { -no-cookies-keep }
 .javasoft.com
 .sun.com
 .yahoo.com
 .msdn.microsoft.com
 .redhat.com

 # Alternative way of saying the same thing
 {-no-cookies-set -no-cookies-read -no-cookies-keep}
 .sourceforge.net
 .sf.net
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Now turn off <quote>fast redirects</quote>, and then we allow two exceptions:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 # Turn them off!
 {+fast-redirects}
 
 # Reverse it for these two sites, which don't work right without it.
 {-fast-redirects}
 www.ukc.ac.uk/cgi-bin/wac\.cgi\?
 login.yahoo.com
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Turn on page filtering according to rules in the defined sections 
 of <filename>default.filter</filename>, and make one exception for 
 Sourceforge:
 </para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 # Run everything through the filter file, using only the
 # specified sections:
 +filter{html-annoyances} +filter{js-annoyances} +filter{no-popups}\
 +filter{webbugs} +filter{nimda} +filter{banners-by-size}
              
 # Then disable filtering of code from sourceforge!
 {-filter}
 .cvs.sourceforge.net
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Now some URLs that we want <quote>blocked</quote> (normally generates 
 the <quote>blocked</quote> banner). Many of these use regular expressions
 that will expand to match multiple URLs:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  # Blocklist:
  {+block}
  /.*/(.*[-_.])?ads?[0-9]?(/|[-_.].*|\.(gif|jpe?g))
  /.*/(.*[-_.])?count(er)?(\.cgi|\.dll|\.exe|[?/])
  /.*/(ng)?adclient\.cgi
  /.*/(plain|live|rotate)[-_.]?ads?/
  /.*/(sponsor)s?[0-9]?/
  /.*/_?(plain|live)?ads?(-banners)?/
  /.*/abanners/
  /.*/ad(sdna_image|gifs?)/
  /.*/ad(server|stream|juggler)\.(cgi|pl|dll|exe)
  /.*/adbanners/
  /.*/adserver
  /.*/adstream\.cgi
  /.*/adv((er)?ts?|ertis(ing|ements?))?/
  /.*/banner_?ads/
  /.*/banners?/
  /.*/banners?\.cgi/
  /.*/cgi-bin/centralad/getimage
  /.*/images/addver\.gif
  /.*/images/marketing/.*\.(gif|jpe?g)
  /.*/popupads/
  /.*/siteads/
  /.*/sponsor.*\.gif
  /.*/sponsors?[0-9]?/
  /.*/advert[0-9]+\.jpg
  /Media/Images/Adds/
  /ad_images/
  /adimages/
  /.*/ads/
  /bannerfarm/
  /grafikk/annonse/
  /graphics/defaultAd/
  /image\.ng/AdType
  /image\.ng/transactionID
  /images/.*/.*_anim\.gif # alvin brattli
  /ip_img/.*\.(gif|jpe?g)
  /rotateads/
  /rotations/ 
  /worldnet/ad\.cgi
  /cgi-bin/nph-adclick.exe/
  /.*/Image/BannerAdvertising/
  /.*/ad-bin/
  /.*/adlib/server\.cgi
  /autoads/
   </literallayout>
  </msgtext> 
 </literal>
</para>

<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 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>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->
<sect3>
<title>Aliases</title>
<para>
 Custom <quote>actions</quote>, known to <application>Privoxy</application>
 as <quote>aliases</quote>, can be defined by combining other <quote>actions</quote>.
 These can in turn be invoked just like the built-in <quote>actions</quote>.
 Currently, an alias can contain any character except space, tab, <quote>=</quote>,
 <quote>{</quote> or <quote>}</quote>. But please use only <quote>a</quote>-
 <quote>z</quote>, <quote>0</quote>-<quote>9</quote>, <quote>+</quote>, and
 <quote>-</quote>. Alias names are not case sensitive, and 
 <emphasis>must be defined  before anything</emphasis> else in the
 <filename>default.action</filename>file! And there can only be one set of
 <quote>aliases</quote> defined.
</para>

<para>
 Now let's define a few aliases:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 # Useful custom aliases we can use later. These must come first!
 {{alias}}
 +no-cookies = +no-cookies-set +no-cookies-read
 -no-cookies = -no-cookies-set -no-cookies-read
 fragile     = -block -no-cookies -filter -fast-redirects -hide-referer -no-popups
 shop        = -no-cookies -filter -fast-redirects
 +imageblock = +block +image

 #For people who don't like to type too much:  ;-)
 c0 = +no-cookies
 c1 = -no-cookies
 c2 = -no-cookies-set +no-cookies-read
 c3 = +no-cookies-set -no-cookies-read
 #... etc.  Customize to your heart's content.
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Some examples using our <quote>shop</quote> and <quote>fragile</quote>
 aliases from above:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 # These sites are very complex and require
 # minimal interference.
 {fragile}
 .office.microsoft.com
 .windowsupdate.microsoft.com
 .nytimes.com

 # Shopping sites - still want to block ads.
 {shop}
 .quietpc.com
 .worldpay.com   # for quietpc.com
 .jungle.com
 .scan.co.uk

 # These shops require pop-ups
 {shop -no-popups}
 .dabs.com
 .overclockers.co.uk
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 The <quote>shop</quote> and <quote>fragile</quote> aliases are often used for 
 <quote>problem</quote> sites that require most actions to be disabled 
 in order to function properly.

</para>

</sect3>
</sect2>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="filterfile">
<title>The Filter File</title>
<para>
 Any web page can be dynamically modified with the filter file. This
 modification can be removal, or re-writing, of any web page content,
 including tags and non-visible content. The default filter file is
 <filename>default.filter</filename>, located in the config directory. 
</para>

<para>
 This is potentially a very powerful feature, and requires knowledge of both 
 <quote>regular expression</quote> and HTML in order create custom 
 filters. But, there are a number of useful filters included with 
 <application>Privoxy</application> for many common situations.
</para>

<para>
 The included example file is divided into sections. Each section begins 
 with the <literal>FILTER</literal> keyword, followed by the identifier 
 for that section, e.g. <quote>FILTER: webbugs</quote>. Each section performs
 a similar type of filtering, such as <quote>html-annoyances</quote>.
</para>

<para>
 This file uses regular expressions to alter or remove any string in the
 target page. The expressions can only operate on one line at a time. Some
 examples from the included default <filename>default.filter</filename>:
</para>

<para>
 Stop web pages from displaying annoying messages in the status bar by
 deleting such references:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 FILTER: html-annoyances

 # New browser windows should be resizeable and have a location and status
 # bar. Make it so.
 #
 s/resizable="?(no|0)"?/resizable=1/ig s/noresize/yesresize/ig
 s/location="?(no|0)"?/location=1/ig s/status="?(no|0)"?/status=1/ig
 s/scrolling="?(no|0|Auto)"?/scrolling=1/ig
 s/menubar="?(no|0)"?/menubar=1/ig 

 # The &lt;BLINK&gt; tag was a crime!
 #
 s*&lt;blink&gt;|&lt;/blink&gt;**ig

 # Is this evil? 
 #
 #s/framespacing="?(no|0)"?//ig
 #s/margin(height|width)=[0-9]*//gi
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Just for kicks, replace any occurrence of <quote>Microsoft</quote> with
 <quote>MicroSuck</quote>, and have a little fun with topical buzzwords: 
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 FILTER: fun

 s/microsoft(?!.com)/MicroSuck/ig

 # Buzzword Bingo:
 #
 s/industry-leading|cutting-edge|award-winning/&lt;font color=red&gt;&lt;b&gt;BINGO!&lt;/b&gt;&lt;/font&gt;/ig
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Kill those pesky little web-bugs:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 # webbugs: Squish WebBugs (1x1 invisible GIFs used for user tracking)
 FILTER: webbugs

 s/&lt;img\s+[^&gt;]*?(width|height)\s*=\s*['"]?1\D[^&gt;]*?(width|height)\s*=\s*['"]?1(\D[^&gt;]*?)?>/&lt;!-- Squished WebBug --&gt;/sig
   </literallayout>
  </msgtext> 
 </literal>
</para>

</sect2>

<!--  ~  End section  ~  -->



<!--   ~~~~~       New section      ~~~~~     -->

<sect2>
<title>Templates</title>
<para>
 When <application>Privoxy</application> displays one of its internal 
 pages, such as a 404 Not Found error page, it uses the appropriate template.
 On Linux, BSD, and Unix, these are located in
 <filename>/etc/privoxy/templates</filename> by default. These may be
 customized, if desired. <filename>cgi-style.css</filename> is 
 used to control the HTML attributes (fonts, etc).
</para>
<para>
 The default <quote>Blocked</quote> banner page with the bright red top 
 banner, is called just <quote><filename>blocked</filename></quote>. This 
 may be customized or replaced with something else if desired.

</para>
</sect2>

</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 -->


<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="submitactions">
<title>Submitting Ads and <quote>Action</quote> Problems</title>
<para>
 Ads and banners that are not stopped by <application>Privoxy</application> 
 can be submitted to the developers by accessing a special page and filling 
 out the brief, required form. Conversely, you can also report pages, images,
 etc. that <application>Privoxy</application> is blocking, but should not.
 The form itself does require Internet access.
</para>
<para>
 To do this, point your browser to <application>Privoxy</application> 
 at <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
 (shortcut: <ulink url="http://p.p/">http://p.p/</ulink>), and then select 
 <ulink url="javascript:w=Math.floor(screen.width/2);h=Math.floor(screen.height*0.9);void(window.open('http://www.privoxy.org/actions','Feedback','screenx='+w+',width='+w+',height='+h+',scrollbars=yes,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());">Actions file feedback system</ulink>, 
 near the bottom of the page. Paste in the URL that is the cause of the 
 unwanted behavior, and follow the prompts. The developers will 
 try to incorporate a fix for the problem you reported into future versions.
</para>

<para>
 New <filename>default.actions</filename> files will occasionally be made
 available based on your feedback. These 
 will be announced on the 
 <ulink
 url="http://lists.sourceforge.net/lists/listinfo/ijbswa-announce">ijbswa-announce</ulink>
 list.
</para>
</sect2>

</sect1>


<!--   ~~~~~       New section      ~~~~~     -->
<sect1 id="copyright"><title>Copyright and History</title>

<sect2><title>Copyright</title>
<!-- Include copyright.sgml: -->
 &copyright;
<!-- end copyright -->
</sect2>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->

<sect2 id="history"><title>History</title>
<!-- Include history.sgml: -->
 &history;
<!-- end history -->
</sect2>
</sect1>

<!--   ~~~~~       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> can use <quote>regular expressions</quote> 
 in various config files. Assuming support for <quote>pcre</quote> (Perl
 Compatible Regular Expressions) is compiled in, which is the default. Such
 configuration directives do not require regular expressions, but they can be
 used to increase flexibility by matching a pattern with wild-cards against
 URLs.
</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 book ;-)
</para>

<para>
 <quote>Regular expressions</quote> is a way of matching one character
 expression against another to see if it matches or not. One of the
 <quote>expressions</quote> is a literal string of readable characters
 (letter, numbers, etc), and the other is a complex string 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 the complex pattern to be matched against. Perl Compatible
 Regular Expressions is an enhanced form of the regular expression language
 with backward compatibility.
</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.
 </member>
</simplelist></para>

<para><simplelist>
 <member>
  <emphasis>[]</emphasis> - Characters enclosed in brackets will be matched if
  any of the enclosed characters are encountered.
 </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.
 </member>
</simplelist></para>

<para><simplelist>
 <member>
  <emphasis>s/string1/string2/g</emphasis> - This is used to rewrite strings of text. 
  <quote>string1</quote> is replaced by <quote>string2</quote> in this
  example.
 </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>
 A 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>
 <emphasis><literal>s/microsoft(?!.com)/MicroSuck/i</literal></emphasis> - This is 
 a substitution. <quote>MicroSuck</quote> will replace any occurrence of 
 <quote>microsoft</quote>.  The <quote>i</quote> at the end of the expression
 means ignore case. The <quote>(?!.com)</quote> means 
 the match should fail if <quote>microsoft</quote> is followed by
 <quote>.com</quote>. In other words, this acts like a <quote>NOT</quote>
 modifier. In case this is a hyperlink, we don't want to break it ;-).
</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://www.perldoc.com/perl5.6/pod/perlre.html">http://www.perldoc.com/perl5.6/pod/perlre.html</ulink>
</para>

</sect2>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->
<sect2>
<title><application>Privoxy</application>'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>
   Alternately, this may be reached at <ulink
   url="http://p.p/">http://p.p/</ulink>, but this
   variation may not work as reliably as the above in some configurations.
  </para>
 </listitem>

 <listitem>
  <para>  
    Show information about the current configuration: 
  </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 client'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. In this case, <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>

 <listitem>
  <para>  
   Edit the actions list file:
  </para>
   <blockquote>
   <para> 
    <ulink url="http://config.privoxy.org/edit-actions">http://config.privoxy.org/edit-actions</ulink>
   </para>
  </blockquote>
 </listitem>
 
 </itemizedlist>
</para>

<para>
 These may be bookmarked for quick reference.

</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());">Enable Privoxy</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());">Disable Privoxy</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());">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());">View Privoxy 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','Feedback','screenx='+w+',width='+w+',height='+h+',scrollbars=yes,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());">Actions file feedback system</ulink>
   </para>
  </listitem> 

 </itemizedlist>
</para>



<para>
 Credit: The site which gave me 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="actionsanat">
<title>Anatomy of an Action</title>

<para>
 The way <application>Privoxy</application> applies <quote>actions</quote>
 and <quote>filters</quote> 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
 <quote>regular expressions</quote> whose consequences are not always 
 so obvious. <application>Privoxy</application> 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 from the <filename>default.filter</filename> file! It
 also will not tell you about any other URLs that may be embedded within the
 URL you are testing (i.e. a web page). 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 look at an example, <ulink url="http://google.com">google.com</ulink>, 
 one section at a time:
</para>

<para>
 <screen>
 System default actions:

 { -add-header -block -deanimate-gifs -downgrade -fast-redirects -filter 
   -hide-forwarded -hide-from -hide-referer -hide-user-agent -image 
   -image-blocker -limit-connect -no-compression -no-cookies-keep 
   -no-cookies-read -no-cookies-set -no-popups -vanilla-wafer -wafer }
 
 </screen>
</para>

<para>
 This is the top section, and only tells us of the compiled in defaults. This 
 is basically what <application>Privoxy</application> would do if there 
 were not any <quote>actions</quote> defined, i.e. it does nothing. Every action 
 is disabled. This is not particularly informative for our purposes here. OK,
 next section:
</para>

<para>
 <screen>

 Matches for http://google.com:

 { -add-header -block +deanimate-gifs -downgrade +fast-redirects 
   +filter{html-annoyances} +filter{js-annoyances} +filter{no-popups} 
   +filter{webbugs} +filter{nimda} +filter{banners-by-size} +filter{hal} 
   +filter{fun} +hide-forwarded +hide-from{block} +hide-referer{forge} 
   -hide-user-agent -image +image-blocker{blank} +no-compression 
   +no-cookies-keep -no-cookies-read -no-cookies-set +no-popups 
   -vanilla-wafer -wafer }
   /

 { -no-cookies-keep -no-cookies-read -no-cookies-set }
  .google.com

 { -fast-redirects }
  .google.com

 </screen>
</para>

<para>
 This is much more informative, and tells us how we have defined our 
 <quote>actions</quote>, and which ones match for our example, 
 <quote>google.com</quote>. The first grouping shows our default 
 settings, which would apply to all URLs. 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 applies to all URLs as signified by the single forward
 slash -- <quote>/</quote>.
 
</para>

<para>
 These are the default actions we have enabled. But we can define additional
 actions that would be exceptions to these general rules, and then list 
 specific URLs 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 various cookie blocking actions (i.e. we will allow
 cookies here). The second is allowing <quote>fast-redirects</quote>. 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>. So, apparently, we have these actions defined
 somewhere in the lower part of our actions file, and
 <quote>google.com</quote> is referenced in these sections.

</para>

<para>
 And now we pull it altogether 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 -deanimate-gifs -downgrade -fast-redirects 
 +filter{html-annoyances} +filter{js-annoyances} +filter{no-popups} 
 +filter{webbugs} +filter{nimda} +filter{banners-by-size} +filter{hal} 
 +filter{fun} +hide-forwarded +hide-from{block} +hide-referer{forge} 
 -hide-user-agent -image +image-blocker{blank} -limit-connect +no-compression 
 -no-cookies-keep -no-cookies-read -no-cookies-set +no-popups -vanilla-wafer 
 -wafer

 </screen>
</para>

<para>
 Now another example, <quote>ad.doubleclick.net</quote>:
</para>

<para>
 <screen>

 { +block +image }
  .ad.doubleclick.net

 { +block +image }
  ad*.

 { +block +image }
  .doubleclick.net

 </screen>
</para>

<para>
 We'll just show the interesting part here, the explicit matches. It is 
 matched three different times. Each as an <quote>+block +image</quote>,
 which is the expanded form of one of our aliases that had been defined as: 
 <quote>+imageblock</quote>. (<quote>Aliases</quote> 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 <quote>+block</quote> <emphasis>and</emphasis> an
 <quote>+image</quote>. The custom alias <quote>+imageblock</quote> does this
 for us.
</para>

<para>
 One last example. Let's try <quote>http://www.rhapsodyk.net/adsl/HOWTO/</quote>.
 This one is giving us problems. We are getting a blank page. Hmmm...
</para>

<para>
 <screen>

 Matches for http://www.rhapsodyk.net/adsl/HOWTO/:

 { -add-header -block +deanimate-gifs -downgrade +fast-redirects 
   +filter{html-annoyances} +filter{js-annoyances} +filter{no-popups} 
   +filter{webbugs} +filter{nimda} +filter{banners-by-size} +filter{hal} 
   +filter{fun} +hide-forwarded +hide-from{block} +hide-referer{forge} 
   -hide-user-agent -image +image-blocker{blank} +no-compression 
   +no-cookies-keep -no-cookies-read -no-cookies-set +no-popups 
   -vanilla-wafer -wafer }
   /

 { +block +image }
  /ads

 </screen>
</para>

<para>
 Ooops, the <quote>/adsl/</quote> is matching <quote>/ads</quote>! But 
 we did not want this at all! Now we see why we get the blank page. We could
 now add a new action below this that explicitly does <emphasis>not</emphasis>
 block (-block) pages with <quote>adsl</quote>. There are various ways to
 handle such exceptions. Example:
</para>

<para>
 <screen>

 { -block }
  /adsl
 
 </screen>
</para>

<para>
 Now the page displays ;-) Be sure to flush your browser's caches when 
 making such changes. 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 }
  /adsl
 
 </screen>
</para>

<para>
 That actually was very telling 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 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 <quote>{+filter}</quote> actions. Try 
 adding the URL for the site to one of aliases that turn off <quote>+filter</quote>:
</para>

<para>
 <screen>

 {shop}
 .quietpc.com
 .worldpay.com   # for quietpc.com
 .jungle.com
 .scan.co.uk
 .forbes.com
 
 </screen>
</para>

<para>
 <quote>{shop}</quote> is an <quote>alias</quote> that expands to 
 <quote>{ -filter -no-cookies -no-cookies-keep }</quote>. Or you could do 
 your own exception to negate filtering:

</para>

<para>
 <screen>

 {-filter}
 .forbes.com
 
 </screen>
</para>

<para>
 <quote>{fragile}</quote> is an alias that disables most actions. This can be 
 used as a last resort for problem sites. Remember to flush caches! 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>

 <!--

 This program is free software; you can redistribute it 
 and/or modify it under the terms of the GNU General
 Public License as published by the Free Software
 Foundation; either version 2 of the License, or (at
 your option) any later version.

 This program is distributed in the hope that it will
 be useful, but WITHOUT ANY WARRANTY; without even the
 implied warranty of MERCHANTABILITY or FITNESS FOR A
 PARTICULAR PURPOSE.  See the GNU General Public
 License for more details.

 The GNU General Public License should be included with
 this file.  If not, you can view it at
 http://www.gnu.org/copyleft/gpl.html
 or write to the Free Software Foundation, Inc., 59
 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

 $Log: user-manual.sgml,v $
 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>