Changed default port to 8118

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

<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook V3.1//EN">
<!--
 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 1.33 2002/03/03 19:46:13 hal9 Exp $

 Written by and Copyright (C) 2001 the SourceForge
 IJBSWA team.  http://ijbswa.sourceforge.net

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

<!--
Sat 03/02/02 04:53:47 PM

This should be ready for BETA release.

Hal Burgiss <hal@foobox.net>
-->

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

<pubdate>$Id: user-manual.sgml,v 1.33 2002/03/03 19:46:13 hal9 Exp $</pubdate>

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

<abstract>
 <para>
  The user manual gives the users information on how to install and configure
  <application>Internet Junkbuster</application>. <application>Internet
  Junkbuster</application> is an application that provides privacy and
  security to users of the World Wide Web.
 </para>
 <para>
You can find the latest version of the user manual at  <ulink url="http://ijbswa.sourceforge.net/user-manual/">http://ijbswa.sourceforge.net/user-manual/</ulink>.
 </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="introduction"><title>Introduction</title>
<para>
 <application>Internet Junkbuster</application> is a web proxy with advanced
 filtering capabilities for protecting privacy, filtering and modifying web
 page content, managing cookies, controlling access, and removing ads,
 banners, pop-ups and other obnoxious Internet Junk.
 <application>Junkbuster</application> has a very flexible configuration and
 can be customized to suit individual needs and tastes. <application>Internet
 Junkbuster</application> has application for both stand-alone systems and
 multi-user networks.
</para>

<para>
 This documentation is included with the current BETA version of
 <application>Internet Junkbuster</application> and 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>

<para>
 Since this is a BETA version, not all new features are well tested. This
 documentation may be slightly out of sync as a result. And there
 <emphasis>may be</emphasis> bugs, though hopefully not many! 
</para>


<!--   ~~~~~       New section      ~~~~~     -->
<sect2>
<title>New Features</title>
<para>
 In addition to <application>Junkbuster's</application> traditional features
 of ad and banner blocking and cookie management, this is a list of new
 features currently under development:
</para>

<para>
 <itemizedlist>

 <listitem>
  <para>
   Integrated browser based configuration and control utility (<ulink
   url="http://i.j.b">http://i.j.b</ulink>). Browser-based tracing of rule
   and filter effects.
  </para>
 </listitem> 

 <listitem>
  <para>
   Modularized configuration that will allow for system wide settings, and
   individual user settings. (not implemented yet, probably a 3.1 feature)
  </para>
 </listitem> 

 <listitem>
  <para>
    Blocking of annoying pop-up browser windows.
  </para>
 </listitem> 

 <listitem>
  <para>
   HTTP/1.1 compliant (most, but not all 1.1 features are supported).
  </para>
 </listitem> 

 <listitem>
  <para>
   Support for Perl Compatible Regular Expressions in the configuration files, and 
   generally a more sophisticated and flexible configuration syntax over
   previous versions. 
  </para>
 </listitem> 

 <listitem>
  <para>
   GIF de-animation. 
  </para>
 </listitem> 
 
 <listitem>
  <para>
   Web page content filtering (removes banners based on size,
   invisible <quote>web-bugs</quote>, JavaScript, pop-ups, status bar abuse,
   etc.)
  </para>
 </listitem> 
 
 <listitem>
  <para>
   Bypass many click-tracking scripts (avoids script redirection).
 
  </para>
 </listitem> 
 
 <listitem>
  <para>
   Multi-threaded (POSIX and native threads).
  </para>
 </listitem> 

 <listitem>
  <para>
   Auto-detection and re-reading of config file changes.
  </para>
 </listitem> 

 <listitem>
  <para>
   User-customizable HTML templates (e.g. 404 error page).
  </para>
 </listitem> 

 <listitem>
  <para>
   Improved cookie management features (e.g. session based cookies).
  </para>
</listitem> 

 <listitem>
  <para>
   Builds from source on most UNIX-like systems. Packages available for: Linux
   (RedHat, SuSE, or Debian), Windows, Sun Solaris, Mac OSX, OS/2.
 
  </para>
 </listitem> 

 <listitem>
  <para>
   In addition, the configuration is much more powerful and versatile over-all.
  </para>
</listitem> 

 </itemizedlist>
</para>

</sect2>

</sect1>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->
<sect1 id="installation"><title>Installation</title>
<para>
 <application>Junkbuster</application> is available as raw source code, or
 pre-compiled binaries. See the <ulink
 url="http://sourceforge.net/projects/ijbswa/">Junkbuster Home Page</ulink>
 for current release info. <application>Junkbuster</application> is also available
 via <ulink
 url="http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/ijbswa/current/">CVS</ulink>.
 This is the recommended approach at this time. But please be aware that CVS 
 is constantly changing, and it may break in mysterious ways.
</para>

<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="installation-source"><title>Source</title>
<para>
 For gzipped tar archives, unpack the source:
</para>

<para>
 <screen>
 tar xzvf ijb_source_* [.tgz or .tar.gz]
 cd ijb_source_2.9.10_beta
 </screen>
</para>

<para>
 For retrieving the current CVS sources, you'll need the CVS 
 package installed first. To download CVS source:
</para>

<para>
 <screen>
  cvs -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa login
  cvs -z3 -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa co current
  cd current
 </screen>
</para>

<para>
 This will create a directory named <filename>current/</filename>, which will 
 contain the source tree.
</para>

<para>
 Then, in either case, to build from tarball/CVS source:
</para>

<para>
 <screen>
 ./configure      (--help to see options)
 make             (the make from gnu, gmake for *BSD) 
 su 
 make -n install  (to see where all the files will go)
 make install     (to really install)
 </screen>
</para>

<para>
 For Redhat and SuSE Linux RPM packages, see below.
</para>

</sect2>


<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="installation-rh"><title>Red Hat</title>
<para>
 To build Redhat RPM packages, install source as above. Then:
</para>

<para>
 <screen>
 autoheader   [suggested for CVS source]
 autoconf     [suggested for CVS source]
 ./configure
 make redhat-dist
 </screen>
</para>

<para>
 This will create both binary and src RPMs in the usual places. Example:
</para>

<para>
 &nbsp;&nbsp;&nbsp;/usr/src/redhat/RPMS/i686/junkbuster-2.9.10-1.i686.rpm
</para>
<para>
 &nbsp;&nbsp;&nbsp;/usr/src/redhat/SRPMS/junkbuster-2.9.10-1.src.rpm
</para>

<para>
 To install, of course:
</para>

<para>
 <screen>
 rpm -Uvv /usr/src/redhat/RPMS/i686/junkbuster-2.9.10-1.i686.rpm
 </screen>
</para>

<para>
 This will place the <application>Junkbuster</application> configuration 
 files in <filename>/etc/junkbuster/</filename>, and log files in 
 <filename>/var/log/junkbuster/</filename>.
</para>

</sect2>

<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="installation-suse"><title>SuSE</title>
<para>
 To build SuSE RPM packages, install source as above. Then:
</para>

<para>
 <screen>
 autoheader   [suggested for CVS source]
 autoconf     [suggested for CVS source]
 ./configure
 make suse-dist
 </screen>
</para>

<para>
 This will create both binary and src RPMs in the usual places. Example:
</para>

<para>
 &nbsp;&nbsp;&nbsp;/usr/src/packages/RPMS/i686/junkbuster-2.9.10-1.i686.rpm
</para>
<para>
 &nbsp;&nbsp;&nbsp;/usr/src/packages/SRPMS/junkbuster-2.9.10-1.src.rpm
</para>

<para>
 To install, of course:
</para>

<para>
 <screen>
 rpm -Uvv /usr/src/packages/RPMS/i686/junkbuster-2.9.10-1.i686.rpm
 </screen>
</para>

<para>
 This will place the <application>Junkbuster</application> configuration 
 files in <filename>/etc/junkbuster/</filename>, and log files in 
 <filename>/var/log/junkbuster/</filename>.
</para>

</sect2>


<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="installation-os2"><title>OS/2</title>

<!--
Thanx David Schmidt!
-->

<para>
 <application>Junkbuster</application> is packaged in a WarpIN self-
 installing archive.  The self-installing program will be named depending
 on the release version, something like:
 <filename>ijbos2_setup_1.2.3.exe</filename>.  In order to install it, simply
 run this executable or double-click on its icon and follow the WarpIN
 installation panels.  A shadow of the <application>Junkbuster</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>Junkbuster</application>
 into will contain all of the configuration files.
</para>

<para>
 If you would like to build binary images on OS/2 yourself, you will need
 a few Unix-like tools: autoconf, autoheader and sh.  These tools will be
 used to create the required config.h file, which is not part of the 
 source distribution because it differs based on platform.  You will also
 need a compiler.
 The distribution has been created using IBM VisualAge compilers, but you
 can use any compiler you like.  GCC/EMX has the disadvantage of needing 
 to be single-threaded due to a limitation of EMX's implementation of the
 select() socket call.
</para>

<para>
 In addition to needing the source code distribution as outlined earlier,
 you will want to extract the <filename>os2seutp</filename> directory from CVS:
 <screen>
 cvs -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa login          
 cvs -z3 -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa co os2setup
 </screen>
 This will create a directory named os2setup/, which will contain the
 <filename>Makefile.vac</filename> makefile and <filename>os2build.cmd</filename>
 which is used to completely create the binary distribution.  The sequence
 of events for building the executable for yourself goes something like this:
 <screen>
 cd current
 autoheader
 autoconf
 sh configure
 cd ..\os2setup
 nmake -f Makefile.vac
 </screen>
 You will see this sequence laid out in <filename>os2build.cmd</filename>.
</para>

</sect2>


<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="installation-win"><title>Windows</title>
<para>Click-click. (I need help on this. Not a clue here. Also for 
configuration section below. HB.)
</para>
</sect2>

<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="installation-other"><title>Other</title>
<para>
 Some quick notes on other Operating Systems.
</para>

<para>
 For FreeBSD (and other *BSDs?), the build will require <command>gmake</command> 
 instead of the included <command>make</command>. <command>gmake</command> is
 available from <ulink url="http://www.gnu.org">http://www.gnu.org</ulink>.
 The rest should be the same as above for Linux/Unix.
</para>

</sect2>

</sect1>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->
<sect1 id="configuration"><title>Junkbuster Configuration</title>
<para>
 For Unix, *BSD and Linux, all configuration files are located in
 <filename>/etc/junkbuster/</filename> by default. For MS Windows, OS/2, and
 AmigaOS these are all in the same directory as the 
 <application>Junkbuster</application> executable. 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 will 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>
    The <filename>ijb.action</filename> file is used  to define various 
    <quote>actions</quote> relating to images, banners, pop-ups, access
    restrictions, banners and cookies. There is a CGI based editor for this
    file that can be accessed via <ulink
    url="http://i.j.b">http://i.j.b</ulink>. This is the easiest method of
    configuring actions. (Other actions 
    files are included as well with differing levels of filtering 
    and blocking, e.g. <filename>ijb-basic.action</filename>.)
   </para>
  </listitem> 

  <listitem>
   <para>
    The <filename>re_filterfile</filename> file can be used to rewrite the raw
    page content, including text as well as embedded HTML and JavaScript.
   </para>
  </listitem> 

 </itemizedlist>
</para>

<para>
 <filename>ijb.action</filename> and <filename>re_filterfile</filename> 
 can use Perl style regular expressions for maximum flexibility. All files use
 the <quote><literal>#</literal></quote> character to denote a comment. Such
 lines are not processed by <application>Junkbuster</application>. After
 making any changes, there is no need to restart
 <application>Junkbuster</application> in order for the changes to take
 effect. <application>Junkbuster</application> should detect such changes 
 automatically.
</para>

<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>

<!--   ~~~~~       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>blockfile blocklist.ini</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Indicates that the blockfile is named <quote>blocklist.ini</quote>.
</para>

<para>
 A <quote><literal>#</literal></quote> indicates a comment.  Any part of a
 line following a <quote><literal>#</literal></quote> is ignored, except if
 the <quote><literal>#</literal></quote> is preceded by a
 <quote><literal>\</literal></quote>.
</para>

<para>
 Thus, by placing a <quote><literal>#</literal></quote> at the start of an
 existing configuration line, you can make it a comment and it will be treated
 as if it weren't there. This is called <quote>commenting out</quote> an
 option and can be useful to turn off features: If you comment out the
 <quote>logfile</quote> line, <application>junkbuster</application> will not
 log to a file at all. Watch for the <quote>default:</quote> section in each
 explanation to see what happens if the option is left unset (or commented
 out). 
</para>

<para>
 Long lines can be continued on the next line by using a
 <quote><literal>\</literal></quote> as the very last character.
</para>

<para>
 There are various aspects of <application>Junkbuster</application> behavior 
 that can be tuned.
</para>


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

<sect3>
<title>Defining Other Configuration Files</title>

<para>
 <application>Junkbuster</application> can use a number of other files to tell it
 what ads to block, what cookies to accept, etc.  This section of the
 configuration file tells <application>Junkbuster</application> where to find
 all those other files. 
</para>

<para>
 On <application>Windows</application> and <application>AmigaOS</application>,
 <application>Junkbuster</application> looks for these files in the same
 directory as the executable.  On Unix and  OS/2,
 <application>Junkbuster</application> looks for these files in the current
 working directory. In either case, an absolute path name can be used to
 avoid problems.
</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, only <filename>confdir/templates</filename> is used for storing HTML
 templates for CGI results. 
</para>

<para>
 The location of the configuration files:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>confdir  /etc/junkbuster</emphasis>       # No trailing /, please.
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 The directory where all logging (i.e. <filename>logfile</filename> and 
 <filename>jarfile</filename>) takes place. No trailing
 <quote><literal>/</literal></quote>, please: 
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>logdir  /var/log/junkbuster</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Note that all file specifications below are relative to 
 the above two directories!
</para>

<para>
 The <quote>ijb.action</quote> file contains patterns to specify the actions to
 apply to requests for each site. Default: Cookies to and from all
 destinations are kept only during the current browser session (i.e. they 
 are not saved to disk). Pop-ups are disabled for all sites. All sites are
 filtered if <quote>re_filterfile</quote> specified. No sites are blocked. An
 empty image is displayed for filtered ads and other images (formerly
 <quote>tinygif</quote>). The syntax of this file is explained in detail <link
 linkend="actionsfile">below</link>.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>actionsfile  ijb.action</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 The <quote>re_filterfile</quote> file contains content modification rules.
 These rules permit powerful changes on the content of Web pages, e.g., you
 could disable your favorite JavaScript annoyances, rewrite the actual
 content, or just have some fun replacing <quote>Microsoft</quote> with
 <quote>MicroSuck</quote> wherever it appears on a Web page. Default: No
 content modification, or whatever the developers are playing with :-/
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>re_filterfile  re_filterfile</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 The logfile is where all logging and error messages are written. The logfile
 can be useful for tracking down a problem with
 <application>Junkbuster</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/junkbuster.*
 +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>

<para>
 Default: Log to the a file named <filename>logfile</filename>. 
 Comment out to disable logging.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>logfile  logfile</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 The <quote>jarfile</quote> defines where
 <application>Junkbuster</application> stores the cookies it intercepts.  Note
 that if you use a <quote>jarfile</quote>, it may grow quite large. Default:
 Don't store intercepted cookies.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>#jarfile  jarfile</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 If you specify a <quote>trustfile</quote>,
 <application>Junkbuster</application> will only allow access to sites that
 are named in the trustfile. You can also mark sites as trusted referrers,
 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>. This is a very restrictive feature that typical
 users most probably want to leave disabled. Default: Disabled, don't use the
 trust mechanism.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>#trustfile  trust</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>
 
<para>
 If you use the trust mechanism, it is a good idea to write up some on-line
 documentation about your blocking policy and to specify the URL(s) here. They
 will appear on the page that your users receive when they try to access
 untrusted content. Use multiple times for multiple URLs. Default: Don't
 display links on the <quote>untrusted</quote> info page.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>trust-info-url http://www.your-site.com/why_we_block.html</emphasis>
  <emphasis>trust-info-url http://www.your-site.com/what_we_allow.html</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

</sect3>

<!--  ~  End section  ~  -->



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

<sect3>
<title>Other Configuration Options</title>

<para>
 This part of the configuration file contains options that control how
 <application>Junkbuster</application> operates.
</para>

<para>
 <quote>Admin-address</quote> should be set to the email address of the proxy
 administrator. It is used in many of the proxy-generated pages. Default:
 fill@me.in.please.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>#admin-address  fill@me.in.please</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 <quote>Proxy-info-url</quote> can be set to a URL that contains more info
 about this <application>Junkbuster</application> installation, it's
 configuration and policies. It is used in many of the proxy-generated pages
 and its use is highly recommended in multi-user installations, since your
 users will want to know why certain content is blocked or modified. Default:
 Don't show a link to on-line documentation.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>proxy-info-url  http://www.your-site.com/proxy.html</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 <quote>Listen-address</quote> specifies the address and port where
 <application>Junkbuster</application> will listen for connections from your
 Web browser.  The default is to listen on the localhost port 8118, and
 this is suitable for most users.  (In your web browser, under proxy
 configuration, list the proxy server as <quote>localhost</quote> and the
 port as <quote>8118</quote>).
</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. The syntax is 
 <quote>listen-address [&lt;ip-address&gt;]:&lt;port&gt;</quote>. If you leave
 out the IP address, <application>junkbuster</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>aclfile</quote> above), or a firewall.
</para>

<para>
 For example, suppose you are running <application>Junkbuster</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>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>listen-address  192.168.0.1:8118</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 If you want it to listen on all addresses (including the outside
 connection):
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>listen-address  :8118</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 If you do this, consider using ACLs (see <quote>aclfile</quote> above). Note:
 you will need to point your browser(s) to the address and port that you have
 configured here. Default: localhost:8118 (127.0.0.1:8118).
</para>

<para>
 The debug option sets the level of debugging information to log in the
 logfile (and to the console in the Windows version).  A debug level of 1 is
 informative because it will show you each request as it happens.  Higher
 levels of debug are probably only of interest to developers.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  debug         1 # GPC   = show each GET/POST/CONNECT request
  debug         2 # CONN  = show each connection status
  debug         4 # IO    = show I/O status
  debug         8 # HDR   = show header parsing
  debug        16 # LOG   = log all data into the logfile
  debug        32 # FRC   = debug force feature
  debug        64 # REF   = debug regular expression filter 
  debug       128 #       = debug fast redirects
  debug       256 #       = debug GIF de-animation
  debug       512 # CLF   = Common Log Format
  debug      1024 #       = debug kill pop-ups
  debug      4096 # INFO  = Startup banner and warnings.
  debug      8192 # ERROR = Non-fatal errors
    </literallayout>
  </msgtext>
 </literal>
</para>

<para>
 It is <emphasis>highly recommended</emphasis> that you enable ERROR
 reporting (debug 8192), at least until the next stable release.
</para>

<para>
 The reporting of FATAL errors (i.e. ones which crash 
 <application>JunkBuster</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> ONLY, do not enable anything else.
</para>

<para>
 Multiple <quote>debug</quote> directives, are OK - they're logical-OR'd
 together. 
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>debug    15     # same as setting the first 4 listed above</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Default:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>debug   1     # URLs</emphasis>
  <emphasis>debug   4096  # Info</emphasis>
  <emphasis>debug   8192  # Errors - *we highly recommended enabling this*</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 <application>Junkbuster</application> normally uses
 <quote>multi-threading</quote>, a software technique that permits it to
 handle many different requests simultaneously. In some cases you may wish to
 disable this -- particularly if you're trying to debug a problem.  The
 <quote>single-threaded</quote> option forces
 <application>Junkbuster</application> to handle requests sequentially.
 Default: Multi-threaded mode.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>#single-threaded</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 <quote>toggle</quote> allows you to temporarily disable all
 <application>Junkbuster's</application>  filtering. Just set <quote>toggle
 0</quote>.
</para>

<para>
 The Windows version of <application>Junkbuster</application> puts an icon in
 the system tray, which also allows you to change this option.  If you
 right-click on that icon (or select the <quote>Options</quote> menu), one
 choice is <quote>Enable</quote>. Clicking on enable toggles
 <application>Junkbuster</application> on and off. This is useful if you want
 to temporarily disable <application>Junkbuster</application>, e.g., to access
 a site that requires cookies which you would otherwise have blocked. This can also
 be toggled via a web browser at the <application>Junkbuster</application>
 internal address of <ulink url="http://i.j.b">http://i.j.b</ulink> on 
 any platform.
</para>

<para>
 <quote>toggle 1</quote> means <application>Junkbuster</application> runs
 normally, <quote>toggle 0</quote> means that
 <application>Junkbuster</application> becomes a non-anonymizing non-blocking
 proxy. Default: 1 (on). 
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>toggle    1</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 For content filtering, i.e. the <quote>+filter</quote> and
 <quote>+deanimate-gif</quote> actions, it is necessary that 
 <application>Junkbuster</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.
</para>

<para>
 The <application>buffer-limit</application> option lets you set the maximum
 size in Kbytes that each buffer may use. When the documents buffer exceeds
 this size, it is flushed to the client unfiltered and no further attempt to
 filter the rest of it is made. Remember that there may multiple threads
 running, which might require increasing the <quote>buffer-limit</quote>
 Kbytes <emphasis>each</emphasis>, unless you have enabled 
 <quote>single-threaded</quote> above.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>buffer-limit    4069</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 To enable the web-based <filename>ijb.action</filename> file editor set
 <application>enable-edit-actions</application> to 1, or 0 to disable.  Note
 that you must have compiled <application>JunkBuster</application> with
 support for this feature, otherwise this option has no effect. This 
 internal page can be reached at <ulink
 url="http://i.j.b">http://i.j.b</ulink>.
 </para>

<para>
 Security note: If this is enabled, anyone who can use the proxy
 can edit the actions file, and their changes will affect all users.
 For shared proxies, you probably want to disable this. Default: enabled.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>enable-edit-actions    1</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Allow <application>JunkBuster</application> to be toggled on and off
 remotely, using your web browser.  Set <quote>enable-remote-toggle</quote>to
 1 to enable, and 0 to disable.  Note that you must have compiled 
 <application>JunkBuster</application> with support for this feature,
 otherwise this option has no effect.
</para>

<para>
 Security note:  If this is enabled, anyone who can use the proxy can toggle
 it on or off (see <ulink url="http://i.j.b">http://i.j.b</ulink>), and
 their changes will affect all users. For shared proxies, you probably want to
 disable this. Default: enabled.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>enable-remote-toggle    1</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

</sect3>

<!--  ~  End section  ~  -->


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

<sect3>
<title>Access Control List (ACL)</title>
<para>
 Access controls are included at the request of some ISPs and systems
 administrators, and are not usually needed by individual users. Please note
 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>
 If no access settings are specified, the proxy talks to anyone that
 connects. If any access settings file are specified, then the proxy
 talks only to IP addresses permitted somewhere in this file and not
 denied later in this file.
</para>

<para>
 Summary -- if using an ACL:
</para>

 <simplelist>
  <member>
   Client must have permission to receive service.
  </member>
 </simplelist>
 <simplelist>
  <member>
   LAST match in ACL wins.
  </member>
 </simplelist>
 <simplelist>
  <member>
   Default behavior is to deny service.
  </member>
 </simplelist>

<para>
 The syntax for an entry in the Access Control List is:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  ACTION    SRC_ADDR[/SRC_MASKLEN]    [ DST_ADDR[/DST_MASKLEN] ]
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Where the individual fields are:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 <emphasis>ACTION</emphasis>      = <quote>permit-access</quote> or <quote>deny-access</quote>

 <emphasis>SRC_ADDR</emphasis>    = client hostname or dotted IP address
 <emphasis>SRC_MASKLEN</emphasis> = number of bits in the subnet mask for the source

 <emphasis>DST_ADDR</emphasis>    = server or forwarder hostname or dotted IP address
 <emphasis>DST_MASKLEN</emphasis> = number of bits in the subnet mask for the target
   </literallayout>
  </msgtext> 
 </literal>
</para>


<para> 
 The field separator (FS) is whitespace (space or tab).
</para>

<para>
 IMPORTANT NOTE: If the <application>junkbuster</application> is using a
 forwarder (see below) or a gateway for a particular destination URL, the
 <literal>DST_ADDR</literal> that is examined is the address of the forwarder
 or the gateway and <emphasis>NOT</emphasis> the address of the ultimate
 target. This is necessary because it may be impossible for the local
 <application>Junkbuster</application> to determine the address of the
 ultimate target (that's often what gateways are used for).
</para>

<para>
 Here are a few examples to show how the ACL features work:
</para>

<para>
 <quote>localhost</quote> is OK -- no DST_ADDR implies that
 <emphasis>ALL</emphasis> destination addresses are OK:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>permit-access  localhost</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 A silly example to illustrate permitting any host on the class-C subnet with
 <application>Junkbuster</application> to go anywhere:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>permit-access    www.junkbusters.com/24</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Except deny one particular IP address from using it at all:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>deny-access      ident.junkbusters.com</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 You can also specify an explicit network address and subnet mask.
 Explicit addresses do not have to be resolved to be used.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>permit-access    207.153.200.0/24</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 A subnet mask of 0 matches anything, so the next line permits everyone.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>permit-access    0.0.0.0/0</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Note, you <emphasis>cannot</emphasis> say:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>permit-access    .org</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 to allow all *.org domains. Every IP address listed must resolve fully.
</para>

<para>
 An ISP may want to provide a <application>Junkbuster</application> that is
 accessible by <quote>the world</quote> and yet restrict use of some of their
 private content to hosts on its internal network (i.e. its own subscribers).
 Say, for instance the ISP owns the Class-B IP address block 123.124.0.0 (a 16
 bit netmask). This is how they could do it:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 <emphasis>permit-access 0.0.0.0/0   0.0.0.0/0</emphasis>   # other clients can go anywhere 
                                       # with the following exceptions:
 
 <emphasis>deny-access</emphasis>   0.0.0.0/0   123.124.0.0/16 # block all external requests for
                                          # sites on the ISP's network

 <emphasis>permit 0.0.0.0/0   www.my_isp.com</emphasis>        # except for the ISP's main 
                                          # web site

 <emphasis>permit 123.124.0.0/16 0.0.0.0/0</emphasis>          # the ISP's clients can go 
                                          # anywhere
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Note that if some hostnames are listed with multiple IP addresses, 
 the primary value returned by DNS (via gethostbyname()) is used. Default:
 Anyone can access the proxy.
</para>

</sect3>

<!--  ~  End section  ~  -->


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

<sect3>
<title>Forwarding</title>

<para>
 This feature allows chaining of HTTP requests via multiple proxies.
 It can be used to better protect privacy and confidentiality when
 accessing specific domains by routing requests to those domains
 to a special purpose filtering proxy such as lpwa.com. Or to use 
 a caching proxy to speed up browsing.
</para>

<para>
 It can also be used in an environment with multiple networks to route
 requests via multiple gateways allowing transparent access to multiple
 networks without having to modify browser configurations.
</para>

<para>
 Also specified here are SOCKS proxies. <application>Junkbuster</application>
 SOCKS 4 and SOCKS 4A. The difference is that SOCKS 4A will resolve the target
 hostname using DNS on the SOCKS server, not our local DNS client.
</para>

<para>
 The syntax of each line is:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 <emphasis>forward target_domain[:port] http_proxy_host[:port]</emphasis>
 <emphasis>forward-socks4  target_domain[:port] socks_proxy_host[:port] http_proxy_host[:port]</emphasis>
 <emphasis>forward-socks4a target_domain[:port] socks_proxy_host[:port] http_proxy_host[:port]</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 If http_proxy_host is <quote>.</quote>, then requests are not forwarded to a
 HTTP proxy but are made directly to the web servers.
</para>

<para>
 Lines are checked in sequence, and the last match wins.
</para>

<para>
 There is an implicit line equivalent to the following, which specifies that
 anything not finding a match on the list is to go out without forwarding
 or gateway protocol, like so:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>forward   .*   .       </emphasis># implicit
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 In the following common configuration, everything goes to Lucent's LPWA,
 except SSL on port 443 (which it doesn't handle):
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 <emphasis>forward   .*     lpwa.com:8000</emphasis>
 <emphasis>forward   :443   .</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 See the FAQ for instructions on how to automate the login procedure for LPWA.
 Some users have reported difficulties related to LPWA's use of
 <quote>.</quote> as the last element of the domain, and have said that this
 can be fixed with this:
</para>
   
<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>forward   lpwa.  lpwa.com:8000</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>
 
<para>
 (NOTE: the syntax for specifying target_domain has changed since the
 previous paragraph was written -- it will not work now.  More information
 is welcome.)
</para>

<para>
 In this fictitious example, everything goes via an ISP's caching proxy,
 except requests to that ISP:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 <emphasis>forward    .*         caching.myisp.net:8000</emphasis>
 <emphasis>forward    myisp.net  .</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 For the @home network, we're told the forwarding configuration is this:
</para>


<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>forward    .*    proxy:8080</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Also, we're told they insist on getting cookies and JavaScript, so you should 
 add home.com to the cookie file. We consider JavaScript a security risk.
 Java need not be enabled.
</para>

<para>
 In this example direct connections are made to all <quote>internal</quote>
 domains, but everything else goes through Lucent's LPWA by way of the
 company's SOCKS gateway to the Internet.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 <emphasis>forward-socks4  .*  lpwa.com:8000  firewall.my_company.com:1080</emphasis>
 <emphasis>forward    my_company.com  .</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 This is how you could set up a site that always uses SOCKS but no forwarders:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  <emphasis>forward-socks4a   .*  .  firewall.my_company.com:1080</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 An advanced example for network administrators:
</para>

<para>
 If you have links to multiple ISPs that provide various special content to
 their subscribers, you can configure forwarding to pass requests to the
 specific host that's connected to that ISP so that everybody can see all
 of the content on all of the ISPs.
</para>

<para>
 This is a bit tricky, but here's an example:
</para>


<para>
 host-a has a PPP connection to isp-a.com. And host-b has a PPP connection to
 isp-b.com. host-a can run a <application>Junkbuster</application> proxy with
 forwarding like this: 
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 <emphasis>forward    .*         .</emphasis>
 <emphasis>forward    isp-b.com  host-b:8118</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 host-b can run a <application>Junkbuster</application> proxy with forwarding
 like this: 
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 <emphasis>forward    .*          .</emphasis>
 <emphasis>forward    isp-a.com   host-a:8118</emphasis>
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Now, <emphasis>anyone</emphasis> on the Internet (including users on host-a
 and host-b) can set their browser's proxy to <emphasis>either</emphasis>
 host-a or host-b and be able to browse the content on isp-a or isp-b.
</para>

<para>
 Here's another practical example, for University of Kent at
 Canterbury students with a network connection in their room, who
 need to use the University's Squid web cache.
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 <emphasis>forward  *. ssbcache.ukc.ac.uk:3128</emphasis>  # Use the proxy, except for:
 <emphasis>forward  .ukc.ac.uk            .    </emphasis> # Anything on the same domain as us
 <emphasis>forward  *                     .    </emphasis> # Host with no domain specified
 <emphasis>forward  129.12.*.*            .    </emphasis> # A dotted IP on our /16 network.
 <emphasis>forward  127.*.*.*             .    </emphasis> # Loopback address
 <emphasis>forward  localhost.localdomain .    </emphasis> # Loopback address
 <emphasis>forward  www.ukc.mirror.ac.uk  .    </emphasis> # Specific host
   </literallayout>
  </msgtext> 
 </literal>
</para>

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

<para>
 Your squid configuration could then look like this:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
  # Define junkbuster as parent cache 
 <!-- per feedback from user...
  cache_peer 127.0.0.1 8118 parent 0 no-query 
 --> 
  cache_peer 127.0.0.1 parent 8118 0 no-query
  
  # Define ACL for protocol FTP 
  acl FTP proto FTP 

  # Do not forward ACL FTP to junkbuster 
  always_direct allow FTP 

  # Do not forward ACL CONNECT (https) to junkbuster 
  always_direct allow CONNECT 

  # Forward the rest to junkbuster 
  never_direct allow all 
   </literallayout>
  </msgtext> 
 </literal>
</para>

</sect3>

<!--  ~  End section  ~  -->


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

<sect3>
<title>Windows GUI Options</title>
<!--
Removed references to Win32. HB 09/23/01
-->
<para>
 <application>Junkbuster</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>Junkbuster</application> icon will animate when
 <quote>Junkbuster</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>Junkbuster</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>Junkbuster</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>Junkbuster</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>Junkbuster</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>JunkBuster</application>. If this option is used,
 <application>Junkbuster</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 <quote>ijb.action</quote> file (formerly
 <filename>actionsfile</filename>) is used to define what actions
 <application>Junkbuster</application> takes, and thus determines how images,
 cookies and various other aspects of HTTP content and transactions are
 handled. Images can be anything you want, including ads, banners, or just
 some obnoxious image 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). Changes to <filename>ijb.action</filename> should 
 be immediately visible to <application>Junkbuster</application> without 
 the need to restart.
</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. You can trace
 this process by visiting <ulink
 url="http://i.j.b/show-url-info">http://i.j.b/show-url-info</ulink>. 
</para>

<para>
 The actions file can be edited with a browser by loading 
 <ulink url="http://i.j.b/">http://i.j.b/</ulink>, and then select 
 <quote>Edit Actions</quote>.
</para>

<para>
 There are four types of lines in this file: comments (begin with a 
 <quote>#</quote> character), actions, aliases and patterns, all of which are
 explained below, as well as the configuration file syntax that 
 <application>Junkbuster</application> understands.

</para>


<!--   ~~~~~       New section      ~~~~~     -->
<sect3>
<title>URL Domain and Path Syntax</title>
<para>
 Generally, a pattern has the form &lt;domain&gt;/&lt;path&gt;, where both the
 &lt;domain&gt; and &lt;path&gt; part are optional. If you only specify a
 domain part, the <quote>/</quote> can be left out:
</para>

<para>
 <emphasis>www.example.com</emphasis> - is a domain only pattern and will match any request to
 <quote>www.example.com</quote>.
</para>

<para>
 <emphasis>www.example.com/</emphasis> - means exactly the same.
</para>

<para>
 <emphasis>www.example.com/index.html</emphasis> - matches only the single
 document <quote>/index.html</quote> on <quote>www.example.com</quote>.
</para>

<para>
 <emphasis>/index.html</emphasis> - matches the document <quote>/index.html</quote>, regardless of
 the domain.
</para>

<para>
 <emphasis>index.html</emphasis> - matches nothing, since it would be
 interpreted as a domain name and there is no top-level domain called
 <quote>.html</quote>.
</para>

<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>

<para>
 <emphasis>.example.com</emphasis> - matches any domain that <emphasis>ENDS</emphasis> in 
 <quote>.example.com</quote>.
</para>

<para>
 <emphasis>www.</emphasis> - matches any domain that <emphasis>STARTS</emphasis> with
 <quote>www</quote>.
</para>

<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. And you can define character classes in square
 brackets and they can be freely mixed:
</para>

<para>
 <emphasis>ad*.example.com</emphasis> - matches <quote>adserver.example.com</quote>, 
 <quote>ads.example.com</quote>, etc but not <quote>sfads.example.com</quote>.
</para>

<para>
 <emphasis>*ad*.example.com</emphasis> - matches all of the above, and then some.
</para>

<para>
 <emphasis>.?pix.com</emphasis> - matches <quote>www.ipix.com</quote>,
 <quote>pictures.epix.com</quote>, <quote>a.b.c.d.e.upix.com</quote>, etc. 
</para>

<para>
 <emphasis>www[1-9a-ez].example.com</emphasis> - matches <quote>www1.example.com</quote>, 
 <quote>www4.example.com</quote>, <quote>wwwd.example.com</quote>, 
 <quote>wwwz.example.com</quote>, etc., but <emphasis>not</emphasis> 
 <quote>wwww.example.com</quote>.
</para>

<para>
 If <application>Junkbuster</application> was compiled with
 <quote>pcre</quote> support (default), Perl compatible regular expressions
 can be used. See the <filename>pcre/docs/</filename> directory or <quote>man
 perlre</quote> (also available on  <ulink
 url="http://www.perldoc.com/perl5.6/pod/perlre.html">http://www.perldoc.com/perl5.6/pod/perlre.html</ulink>)
 for details. A brief discussion of regular expressions is in the 
 <link linkend="regex">Appendix</link>. For instance:
</para>

<para>
 <emphasis>/.*/advert[0-9]+\.jpe?g</emphasis>  - would match a URL from any
 domain, with any path that includes <quote>advert</quote> followed
 immediately by one or more digits, then a <quote>.</quote> and ending in
 either <quote>jpeg</quote> or <quote>jpg</quote>. So we match
 <quote>example.com/ads/advert2.jpg</quote>, and
 <quote>www.example.com/ads/banners/advert39.jpeg</quote>, but not
 <quote>www.example.com/ads/banners/advert39.gif</quote> (no gifs in the
 example pattern).
</para>

<para>
 Please 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:
</para>

<para>
 <emphasis>www.example.com/(?-i)PaTtErN.*</emphasis> - will match only
 documents whose path starts with <quote>PaTtErN</quote> in
 <emphasis>exactly</emphasis> this capitalization.
</para>

</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>JunkBuster</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>ijb.action</filename> file will 
 give a good starting point).
</para>

<para>
 Later defined actions always over-ride earlier ones.  For multi-valued
 actions, the actions are applied in the order they are specified.
</para>

<para>
 The list of valid <application>Junkbuster</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.
  </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>Junkbuster</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:
   http://some.place/some_script?http://some.where-else.
  </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
   requests by <application>Junkbuster</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 remote site.
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+fast-redirects</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </para>
 </listitem>

 <listitem>
  <para>  
   Filter the website through the re_filterfile:
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
 <emphasis>+filter{filename}</emphasis>
     </literallayout>
    </msgtext> 
   </literal>
  </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 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 <quote>Junkbuster</quote> user:
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+hide-user-agent{JunkBuster/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.
  </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>. There are 4 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 <quote>JunkBuster</quote> 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.  
  </para>
  <para>
   <literal>
    <msgtext> 
     <literallayout>
  <emphasis>+image-blocker{logo}</emphasis>
  <emphasis>+image-blocker{blank}</emphasis>
  <emphasis>+image-blocker{http://i.j.b/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>Junkbuster</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>Junkbuster</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>nocompression</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, with one exception for sourceforge:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 # Run everything through the default filter file (<filename>re_filterfile</filename>):
 {+filter}
 
 # But please don't re_filter code from sourceforge!
 {-filter}
 .cvs.sourceforge.net
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Now some URLs that we want <quote>blocked</quote>, ie we won't see them.
 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>

</sect3>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->
<sect3>
<title>Aliases</title>
<para>
 Custom <quote>actions</quote>, known to <application>Junkbuster</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>ijb.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 customer 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>

</sect3>
</sect2>

<!--  ~  End section  ~  -->


<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="filterfile">
<title>The Filter File</title>
<para>
 The filter file defines what filtering of web pages
 <application>Junkbuster</application> does. The default filter file is 
 <filename>re_filterfile</filename>, located in the config directory. In this 
 file, <emphasis>any document content</emphasis>, whether viewable text or
 embedded non-visible content, can be changed. 
</para>

<para>
 This file uses regular expressions to alter or remove any string in the
 target page. Some examples from the included default <filename>re_filterfile</filename>:
</para>

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

<para>
 <literal>
  <msgtext> 
   <literallayout>
 # The status bar is for displaying link targets, not pointless buzzwords.
 # Again, check it out on http://www.airport-cgn.de/.
 s/status='.*?';*//ig
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Just for kicks, replace any occurrence of <quote>Microsoft</quote> with
 <quote>MicroSuck</quote>: 
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 s/microsoft(?!.com)/MicroSuck/ig
   </literallayout>
  </msgtext> 
 </literal>
</para>

<para>
 Kill those auto-refresh tags:
</para>

<para>
 <literal>
  <msgtext> 
   <literallayout>
 # Kill refresh tags. I like to refresh myself. Manually.
 # check it out on http://www.airport-cgn.de/ and go to the arrivals page.
 #
 s/&lt;meta[^&gt;]*http-equiv[^&gt;]*refresh.*URL=([^&gt;]*?)"?&gt;/&lt;link rev="x-refresh" href=$1&gt;/i
 s/&lt;meta[^&gt;]*http-equiv="?page-enter"?[^&gt;]*content=[^&gt;]*&gt;/&lt;!--no page enter for me--&gt;/i
   </literallayout>
  </msgtext> 
 </literal>
</para>

</sect2>

<!--  ~  End section  ~  -->



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

<sect2>
<title>Templates</title>
<para>
 When <application>Junkbuster</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 locate in
 <filename>/etc/junkbuster/templates</filename> by default. These may be
 customized, if desired.

</para>
</sect2>

</sect1>

<!--  ~  End section  ~  -->



<!--   ~~~~~       New section      ~~~~~     -->
<sect1 id="quickstart"><title>Quickstart to Using Junkbuster</title>
<para>
 Install package, then run and enjoy! <application>JunkBuster</application> 
 accepts only one command line option -- the configuration file to be 
 used. Example Unix startup command:
</para>

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

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

<para>
For for SuSE: /etc/rc.d/junkbuster start
</para>

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


<para>
 If no configuration file is specified on the command line,
 <application>Junkbuster</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>Junkbuster</application> will fail to start.
</para>

<para>
 Be sure your browser is set to use the proxy which is by default at
 localhost, port 8118. 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>
 The included default configuration files should give a reasonable starting
 point, though may be somewhat aggressive in blocking junk. You will probably
 want to keep an eye out for sites that require persistent cookies, and add these to
 <filename>ijb.action</filename> as needed. By default, most of these will
 be accepted only during the current browser session, until you add them to
 the configuration. If you want the browser to handle this instead, you will
 need to edit <filename>ijb.action</filename> and disable this feature. If you
 use more than one browser, it would make more sense to let
 <application>Junkbuster</application> handle this. In which case, the
 browser(s) should be set to accept all cookies.
</para>

<para>
 If a particular site shows problems loading properly, try adding it 
 to the <literal>{fragile}</literal> section of
 <filename>ijb.action</filename>. This will turn off most actions for 
 this site.
</para>

<para>
 HTTP/1.1 support is not fully implemented. If browsers that
 support HTTP/1.1 (like <application>Mozilla</application> or recent versions
 of I.E.) experience problems, you might try to force HTTP/1.0 compatibility.
 For Mozilla, look under <literal>Edit -&gt; Preferences -&gt; Debug -&gt;
 Networking</literal>. Or set the <quote>+downgrade</quote> config option in
 <filename>ijb.action</filename>.
</para>

<para>
 After running <application>Junkbuster</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>ijb.action</filename>) 
 can be adjusted by pointing your browser to 
 <ulink url="http://i.j.b/">http://i.j.b/</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>Junkbuster</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>ijb.action</filename> file 
 editor mentioned above, <application>Junkbuster</application> can also 
 be turned <quote>on</quote> and <quote>off</quote> from this page.
</para>

<para>
 If you encounter problems, please verify it is a
 <application>Junkbuster</application> bug, by disabling
 <application>Junkbuster</application>, and then trying the same page. 
 Also, try another browser if possible to eliminate browser or site 
 problems. Before reporting it as a bug, see if there is not a configuration 
 option that is enabled that is causing the page not to load. You can 
 then add an exception for that page or site. If a bug, please report it to
 the developers (see below). 
</para>

</sect1>


<!--   ~~~~~       New section      ~~~~~     -->
<sect1 id="contact"><title>Contacting the Developers, Bug Reporting and Feature
Requests</title>
<para>
 Please do not use the mailing lists for feature requests or 
 bug reports. They are not as easily tracked this way!

</para>

<para>
<!--
To be filled. mention the support forums as the primary channel of
communication (bugs, feature requests, etc.)
-->
 Feature requests and other questions should be posted to the <ulink
 url="http://sourceforge.net/tracker/?atid=361118&amp;group_id=11118&amp;func=browse">Feature
 request page</ulink> at SourceForge. There is also an archive there.
</para>

<para>
 Anyone interested in actively participating in development and related 
 discussions can join the appropriate mailing list  
 <ulink url="http://sourceforge.net/mail/?group_id=11118">here</ulink>.
 Archives are available here too.
</para>

<para>
 Please report bugs, using the form at 
 <ulink url="http://sourceforge.net/tracker/?group_id=11118&amp;atid=111118">Sourceforge</ulink>.
 Please try to verify that it is a <application>Junkbuster</application> bug,
 and not a browser or site bug first. Also, check to make sure this is not
 already a known bug. If you are using your own custom configuration, please
 try the stock configs to see if the problem is a configuration related bug.
</para>

</sect1>


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

<sect2>
<title>License</title>
<para>
 <application>Internet Junkbuster</application> 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.
</para>

<para>
 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, which is available from <ulink
 url="http://www.gnu.org/copyleft/gpl.html">the Free Software Foundation,
 Inc</ulink>, 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
</para>

</sect2>

<!--  ~  End section  ~  -->


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

<sect2>
<title>History</title>
<para>
 <application>Junkbuster</application> was originally written by Anonymous 
 Coders and <ulink
 url="http://www.junkbusters.com/ht/en/ijbfaq.html">Junkbuster's
 Corporation</ulink>, and was released as free open-source software under the
 GNU GPL. <ulink url="http://www.waldherr.org/junkbuster/">Stefan
 Waldherr</ulink> made many improvements, and started the <ulink
 url="http://sourceforge.net/projects/ijbswa/">SourceForge project</ulink> to
 rekindle development. There are now several active developers contributing.
 The last stable release was v2.0.2, which has now grown whiskers ;-).
</para>

</sect2>

</sect1>

<!--   ~~~~~       New section      ~~~~~     -->
<sect1 id="seealso"><title>See also</title>
<para>
 
 <simplelist>
  <member>
   &nbsp; <ulink url="http://sourceforge.net/projects/ijbswa">http://sourceforge.net/projects/ijbswa</ulink>
  </member>
 </simplelist>
 <simplelist>
  <member>
   &nbsp; <ulink url="http://ijbswa.sourceforge.net/">http://ijbswa.sourceforge.net/</ulink>
  </member>
 </simplelist>
 <simplelist>
  <member>
   &nbsp; <ulink url="http://i.j.b/">http://i.j.b/</ulink>
  </member>
 </simplelist>
 <simplelist>
  <member>
   &nbsp; <ulink url="http://www.junkbusters.com/ht/en/cookies.html">http://www.junkbusters.com/ht/en/cookies.html</ulink>
  </member>
 </simplelist>
 <simplelist>
  <member>
   &nbsp; <ulink url="http://www.waldherr.org/junkbuster/">http://www.waldherr.org/junkbuster/</ulink>
  </member>
 </simplelist>
 <simplelist>
  <member>
   &nbsp; <ulink url="http://privacy.net/analyze/">http://privacy.net/analyze/</ulink>
  </member>
 </simplelist>
 <simplelist>
  <member>
   &nbsp;<ulink url="http://www.squid-cache.org/">http://www.squid-cache.org/</ulink>
  </member>
 </simplelist>

</para>
</sect1>



<!--   ~~~~~       New section      ~~~~~     -->
<sect1 id="appendix"><title>Appendix</title>


<!--   ~~~~~       New section      ~~~~~     -->
<sect2 id="regex">
<title>Regular Expressions</title>
<para>
 <application>Junkbuster</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>

<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>

<simplelist>
 <member>
  <emphasis>?</emphasis> - The preceding character or expression is matched ZERO or ONE
  times. Either/or.
 </member>
</simplelist>

<simplelist>
 <member>
  <emphasis>+</emphasis> - The preceding character or expression is matched ONE or MORE
  times.
 </member>
</simplelist>

<simplelist>
 <member>
  <emphasis>*</emphasis> - The preceding character or expression is matched ZERO or MORE
  times.
 </member>
</simplelist>

<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>

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

<simplelist>
 <member>
  <emphasis>()</emphasis> - parentheses are used to group a sub-expression,
  or multiple sub-expressions.
 </member>
</simplelist>

<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>

<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>
 These are just some of the ones you are likely to use when matching URLs with 
 <application>Junkbuster</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>Junkbuster</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>

</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 1.33  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>