-Privoxy User Manual
+ Privoxy 3.0.8 User Manual
-Copyright © 2001, 2002 by Privoxy Developers
+ [Copyright[ (c) 2001 - 2008 by Privoxy Developers]]
-$Id: user-manual.sgml,v 1.104 2002/05/04 08:44:45 swa Exp $
+ $Id: user-manual.txt,v 1.74 2008/01/19 21:41:37 hal9 Exp $
-The user manual gives users information on how to install, configure and use
-Privoxy.
+ The Privoxy User Manual gives users information on how to install,
+ configure and use Privoxy.
-Privoxy is a web proxy with advanced filtering capabilities for protecting
-privacy, filtering web page content, managing cookies, controlling access, and
-removing ads, banners, pop-ups and other obnoxious Internet junk. Privoxy has a
-very flexible configuration and can be customized to suit individual needs and
-tastes. Privoxy has application for both stand-alone systems and multi-user
-networks.
+ Privoxy is a non-caching web proxy with advanced filtering capabilities
+ for enhancing privacy, modifying web page data, managing HTTP cookies,
+ controlling access, and removing ads, banners, pop-ups and other obnoxious
+ Internet junk. Privoxy has a flexible configuration and can be customized
+ to suit individual needs and tastes. Privoxy has application for both
+ stand-alone systems and multi-user networks.
-Privoxy is based on Internet Junkbuster (tm).
+ Privoxy is based on Internet Junkbuster (tm).
-You can find the latest version of the user manual at http://www.privoxy.org/
-user-manual/. Please see the Contact section on how to contact the developers.
+ You can find the latest version of the Privoxy User Manual at
+ http://www.privoxy.org/user-manual/. Please see the Contact section on how
+ to contact the developers.
--------------------------------------------------------------------------------
+ --------------------------------------------------------------------------
+
+ Table of Contents
+
+ 1. Introduction
+
+ 1.1. Features
+
+ 2. Installation
+
+ 2.1. Binary Packages
+
+ 2.1.1. Red Hat and Fedora RPMs
+
+ 2.1.2. Debian and Ubuntu
+
+ 2.1.3. Windows
+
+ 2.1.4. Solaris
+
+ 2.1.5. OS/2
+
+ 2.1.6. Mac OSX
+
+ 2.1.7. AmigaOS
+
+ 2.1.8. FreeBSD
+
+ 2.1.9. Gentoo
+
+ 2.2. Building from Source
+
+ 2.3. Keeping your Installation Up-to-Date
+
+ 3. What's New in this Release
+
+ 3.1. Note to Upgraders
+
+ 4. Quickstart to Using Privoxy
+
+ 4.1. Quickstart to Ad Blocking
+
+ 5. Starting Privoxy
+
+ 5.1. Red Hat and Fedora
+
+ 5.2. Debian
+
+ 5.3. Windows
+
+ 5.4. Solaris, NetBSD, FreeBSD, HP-UX and others
+
+ 5.5. OS/2
+
+ 5.6. Mac OSX
+
+ 5.7. AmigaOS
+
+ 5.8. Gentoo
+
+ 5.9. Command Line Options
+
+ 6. Privoxy Configuration
+
+ 6.1. Controlling Privoxy with Your Web Browser
+
+ 6.2. Configuration Files Overview
+
+ 7. The Main Configuration File
+
+ 7.1. Local Set-up Documentation
+
+ 7.1.1. user-manual
+
+ 7.1.2. trust-info-url
+
+ 7.1.3. admin-address
+
+ 7.1.4. proxy-info-url
+
+ 7.2. Configuration and Log File Locations
+
+ 7.2.1. confdir
+
+ 7.2.2. templdir
+
+ 7.2.3. logdir
+
+ 7.2.4. actionsfile
+
+ 7.2.5. filterfile
+
+ 7.2.6. logfile
+
+ 7.2.7. jarfile
+
+ 7.2.8. trustfile
+
+ 7.3. Debugging
+
+ 7.3.1. debug
+
+ 7.3.2. single-threaded
+
+ 7.4. Access Control and Security
+
+ 7.4.1. listen-address
+
+ 7.4.2. toggle
+
+ 7.4.3. enable-remote-toggle
+
+ 7.4.4. enable-remote-http-toggle
+
+ 7.4.5. enable-edit-actions
+
+ 7.4.6. enforce-blocks
+
+ 7.4.7. ACLs: permit-access and deny-access
+
+ 7.4.8. buffer-limit
+
+ 7.5. Forwarding
+
+ 7.5.1. forward
+
+ 7.5.2. forward-socks4 and forward-socks4a
+
+ 7.5.3. Advanced Forwarding Examples
+
+ 7.5.4. forwarded-connect-retries
+
+ 7.5.5. accept-intercepted-requests
+
+ 7.5.6. allow-cgi-request-crunching
+
+ 7.5.7. split-large-forms
+
+ 7.6. Windows GUI Options
+
+ 8. Actions Files
+
+ 8.1. Finding the Right Mix
+
+ 8.2. How to Edit
+
+ 8.3. How Actions are Applied to Requests
+
+ 8.4. Patterns
+
+ 8.4.1. The Domain Pattern
+
+ 8.4.2. The Path Pattern
+
+ 8.4.3. The Tag Pattern
+
+ 8.5. Actions
+
+ 8.5.1. add-header
+
+ 8.5.2. block
+
+ 8.5.3. client-header-filter
+
+ 8.5.4. client-header-tagger
+
+ 8.5.5. content-type-overwrite
+
+ 8.5.6. crunch-client-header
+
+ 8.5.7. crunch-if-none-match
+
+ 8.5.8. crunch-incoming-cookies
+
+ 8.5.9. crunch-server-header
+
+ 8.5.10. crunch-outgoing-cookies
+
+ 8.5.11. deanimate-gifs
+
+ 8.5.12. downgrade-http-version
+
+ 8.5.13. fast-redirects
+
+ 8.5.14. filter
+
+ 8.5.15. force-text-mode
+
+ 8.5.16. forward-override
+
+ 8.5.17. handle-as-empty-document
+
+ 8.5.18. handle-as-image
+
+ 8.5.19. hide-accept-language
+
+ 8.5.20. hide-content-disposition
+
+ 8.5.21. hide-if-modified-since
+
+ 8.5.22. hide-forwarded-for-headers
+
+ 8.5.23. hide-from-header
+
+ 8.5.24. hide-referrer
+
+ 8.5.25. hide-user-agent
+
+ 8.5.26. inspect-jpegs
+
+ 8.5.27. kill-popups
+
+ 8.5.28. limit-connect
+
+ 8.5.29. prevent-compression
+
+ 8.5.30. overwrite-last-modified
+
+ 8.5.31. redirect
+
+ 8.5.32. send-vanilla-wafer
+
+ 8.5.33. send-wafer
+
+ 8.5.34. server-header-filter
+
+ 8.5.35. server-header-tagger
+
+ 8.5.36. session-cookies-only
+
+ 8.5.37. set-image-blocker
+
+ 8.5.38. treat-forbidden-connects-like-blocks
+
+ 8.5.39. Summary
+
+ 8.6. Aliases
+
+ 8.7. Actions Files Tutorial
+
+ 8.7.1. default.action
+
+ 8.7.2. user.action
+
+ 9. Filter Files
+
+ 9.1. Filter File Tutorial
+
+ 9.2. The Pre-defined Filters
+
+ 10. Privoxy's Template Files
+
+ 11. Contacting the Developers, Bug Reporting and Feature Requests
+
+ 11.1. Get Support
+
+ 11.2. Reporting Problems
+
+ 11.2.1. Reporting Ads or Other Configuration
+ Problems
+
+ 11.2.2. Reporting Bugs
+
+ 11.3. Request New Features
+
+ 11.4. Other
+
+ 12. Privoxy Copyright, License and History
+
+ 12.1. License
+
+ 12.2. History
+
+ 12.3. Authors
+
+ 13. See Also
+
+ 14. Appendix
+
+ 14.1. Regular Expressions
+
+ 14.2. Privoxy's Internal Pages
+
+ 14.2.1. Bookmarklets
+
+ 14.3. Chain of Events
+
+ 14.4. Troubleshooting: Anatomy of an Action
-Table of Contents
1. Introduction
-
- 1.1. Features
-
+
+ This documentation is included with the current stable version of Privoxy,
+ v.3.0.8.
+
+ --------------------------------------------------------------------------
+
+ 1.1. Features
+
+ In addition to the core features of ad blocking and cookie management,
+ Privoxy provides many supplemental features, that give the end-user more
+ control, more privacy and more freedom:
+
+ * Can be run as an "intercepting" proxy, which obviates the need to
+ configure browsers individually.
+
+ * Sophisticated actions and filters for manipulating both server and
+ client headers.
+
+ * Can be chained with other proxies.
+
+ * Integrated browser based configuration and control utility at
+ http://config.privoxy.org/ (shortcut: http://p.p/). Browser-based
+ tracing of rule and filter effects. Remote toggling.
+
+ * Web page filtering (text replacements, removes banners based on size,
+ invisible "web-bugs", JavaScript and HTML annoyances, pop-up windows,
+ etc.)
+
+ * Modularized configuration that allows for standard settings and user
+ settings to reside in separate files, so that installing updated
+ actions files won't overwrite individual user settings.
+
+ * Support for Perl Compatible Regular Expressions in the configuration
+ files, and a more sophisticated and flexible configuration syntax.
+
+ * Improved cookie management features (e.g. session based cookies).
+
+ * GIF de-animation.
+
+ * Bypass many click-tracking scripts (avoids script redirection).
+
+ * Multi-threaded (POSIX and native threads).
+
+ * User-customizable HTML templates for all proxy-generated pages (e.g.
+ "blocked" page).
+
+ * Auto-detection and re-reading of config file changes.
+
+ * Improved signal handling, and a true daemon mode (Unix).
+
+ * Every feature now controllable on a per-site or per-location basis,
+ configuration more powerful and versatile over-all.
+
+ * Many smaller new features added, limitations and bugs removed, and
+ security holes fixed.
+
+ --------------------------------------------------------------------------
+
2. Installation
-
- 2.1. Binary Packages
-
- 2.1.1. Red Hat and SuSE RPMs
- 2.1.2. Debian
- 2.1.3. Windows
- 2.1.4. Solaris, NetBSD, FreeBSD, HP-UX
- 2.1.5. OS/2
- 2.1.6. Max OSX
- 2.1.7. AmigaOS
-
- 2.2. Building from Source
-
-3. Note to Upgraders
-4. Quickstart to Using Privoxy
-5. Starting Privoxy
-
- 5.1. RedHat and Debian
- 5.2. SuSE
- 5.3. Windows
- 5.4. Solaris, NetBSD, FreeBSD, HP-UX and others
- 5.5. OS/2
- 5.6. MAX OSX
- 5.7. AmigaOS
- 5.8. Command Line Options
-
-6. Privoxy Configuration
-
- 6.1. Controlling Privoxy with Your Web Browser
- 6.2. Configuration Files Overview
-
-7. The Main Configuration File
-
- 7.1. Configuration and Log File Locations
-
- 7.1.1. confdir
- 7.1.2. logdir
- 7.1.3. actionsfile
- 7.1.4. filterfile
- 7.1.5. logfile
- 7.1.6. jarfile
- 7.1.7. trustfile
-
- 7.2. Local Set-up Documentation
-
- 7.2.1. user-manual
- 7.2.2. trust-info-url
- 7.2.3. admin-address
- 7.2.4. proxy-info-url
-
- 7.3. Debugging
-
- 7.3.1. debug
- 7.3.2. single-threaded
-
- 7.4. Access Control and Security
-
- 7.4.1. listen-address
- 7.4.2. toggle
- 7.4.3. enable-remote-toggle
- 7.4.4. enable-edit-actions
- 7.4.5. ACLs: permit-access and deny-access
- 7.4.6. buffer-limit
-
- 7.5. Forwarding
-
- 7.5.1. forward
- 7.5.2. forward-socks4 and forward-socks4a
- 7.5.3. Advanced Forwarding Examples
-
- 7.6. Windows GUI Options
-
-8. Actions Files
-
- 8.1. Finding the Right Mix
- 8.2. How to Edit
- 8.3. How Actions are Applied to URLs
- 8.4. Patterns
-
- 8.4.1. The Domain Pattern
- 8.4.2. The Path Pattern
-
- 8.5. Actions
-
- 8.5.1. +add-header
- 8.5.2. +block
- 8.5.3. +deanimate-gifs
- 8.5.4. +downgrade-http-version
- 8.5.5. +fast-redirects
- 8.5.6. +filter
- 8.5.7. +hide-forwarded-for-headers
- 8.5.8. +hide-from-header
- 8.5.9. +hide-referer
- 8.5.10. +hide-user-agent
- 8.5.11. +handle-as-image
- 8.5.12. +set-image-blocker
- 8.5.13. +limit-connect
- 8.5.14. +prevent-compression
- 8.5.15. +session-cookies-only
- 8.5.16. +prevent-reading-cookies
- 8.5.17. +prevent-setting-cookies
- 8.5.18. +kill-popups
- 8.5.19. +send-vanilla-wafer
- 8.5.20. +send-wafer
- 8.5.21. Summary
- 8.5.22. Sample Actions Files
-
- 8.6. Aliases
-
-9. The Filter File
-
- 9.1. The +filter Action
-
-10. Templates
-11. Contacting the Developers, Bug Reporting and Feature Requests
-
- 11.1. Get Support
- 11.2. Report bugs
- 11.3. Request new features
- 11.4. Report ads or other filter problems
- 11.5. Other
-
-12. Copyright, License and History
-
- 12.1. Copyright
- 12.2. License
- 12.3. History
-
-13. See Also
-14. Appendix
-
- 14.1. Regular Expressions
- 14.2. Privoxy's Internal Pages
-
- 14.2.1. Bookmarklets
-
- 14.3. Chain of Events
- 14.4. Anatomy of an Action
-
-1. Introduction
-This documentation is included with the current beta version of Privoxy,
-v.2.9.15, and is mostly complete at this point. The most up to date reference
-for the time being is still the comments in the source files and in the
-individual configuration files. Development of version 3.0 is currently nearing
-completion, and includes many significant changes and enhancements over earlier
-versions. The target release date for stable v3.0 is "soon" ;-).
-
-Since this is a beta version, not all new features are well tested. This
-documentation may be slightly out of sync as a result (especially with CVS
-sources). And there may be bugs, though hopefully not many!
-
--------------------------------------------------------------------------------
-
-1.1. Features
-
-In addition to Internet Junkbuster's traditional features of ad and banner
-blocking and cookie management, Privoxy provides new features, some of them
-currently under development:
-
- * Integrated browser based configuration and control utility at http://
- config.privoxy.org/ (shortcut: http://p.p/). Browser-based tracing of rule
- and filter effects. Remote toggling.
-
- * Web page content filtering (removes banners based on size, invisible
- "web-bugs", JavaScript and HTML annoyances, pop-up windows, etc.)
-
- * Modularized configuration that allows for standard settings and user
- settings to reside in separate files, so that installing updated actions
- files won't overwrite idividual user settings.
-
- * HTTP/1.1 compliant (but not all optional 1.1 features are supported).
-
- * Support for Perl Compatible Regular Expressions in the configuration files,
- and generally a more sophisticated and flexible configuration syntax over
- previous versions.
-
- * Improved cookie management features (e.g. session based cookies).
-
- * GIF de-animation.
-
- * Bypass many click-tracking scripts (avoids script redirection).
-
- * Multi-threaded (POSIX and native threads).
-
- * User-customizable HTML templates for all proxy-generated pages (e.g.
- "blocked" page).
-
- * Auto-detection and re-reading of config file changes.
-
- * Improved signal handling, and a true daemon mode (Unix).
-
- * Every feature now controllable on a per-site or per-location basis,
- configuration more powerful and versatile over-all.
-
- * Many smaller new features added, limitations and bugs removed, and security
- holes fixed.
-
--------------------------------------------------------------------------------
+ Privoxy is available both in convenient pre-compiled packages for a wide
+ range of operating systems, and as raw source code. For most users, we
+ recommend using the packages, which can be downloaded from our Privoxy
+ Project Page.
+
+ Note: On some platforms, the installer may remove previously installed
+ versions, if found. (See below for your platform). In any case be sure to
+ backup your old configuration if it is valuable to you. See the note to
+ upgraders section below.
+
+ --------------------------------------------------------------------------
+
+ 2.1. Binary Packages
+
+ How to install the binary packages depends on your operating system:
+
+ --------------------------------------------------------------------------
+
+ 2.1.1. Red Hat and Fedora RPMs
+
+ RPMs can be installed with rpm -Uvh privoxy-3.0.8-1.rpm, and will use
+ /etc/privoxy for the location of configuration files.
+
+ Note that on Red Hat, Privoxy will not be automatically started on system
+ boot. You will need to enable that using chkconfig, ntsysv, or similar
+ methods.
+
+ If you have problems with failed dependencies, try rebuilding the SRC RPM:
+ rpm --rebuild privoxy-3.0.8-1.src.rpm. This will use your locally
+ installed libraries and RPM version.
+
+ Also note that if you have a Junkbuster RPM installed on your system, you
+ need to remove it first, because the packages conflict. Otherwise, RPM
+ will try to remove Junkbuster automatically if found, before installing
+ Privoxy.
+
+ --------------------------------------------------------------------------
+
+ 2.1.2. Debian and Ubuntu
+
+ DEBs can be installed with apt-get install privoxy, and will use
+ /etc/privoxy for the location of configuration files.
+
+ --------------------------------------------------------------------------
+
+ 2.1.3. Windows
+
+ Just double-click the installer, which will guide you through the
+ installation process. You will find the configuration files in the same
+ directory as you installed Privoxy in.
+
+ Version 3.0.5 beta introduced full Windows service functionality. On
+ Windows only, the Privoxy program has two new command line arguments to
+ install and uninstall Privoxy as a service.
+
+ Arguments:
+
+ --install[:service_name]
+
+ --uninstall[:service_name]
+
+ After invoking Privoxy with --install, you will need to bring up the
+ Windows service console to assign the user you want Privoxy to run under,
+ and whether or not you want it to run whenever the system starts. You can
+ start the Windows services console with the following command:
+ services.msc. If you do not take the manual step of modifying Privoxy's
+ service settings, it will not start. Note too that you will need to give
+ Privoxy a user account that actually exists, or it will not be permitted
+ to write to its log and configuration files.
+
+ --------------------------------------------------------------------------
+
+ 2.1.4. Solaris
+
+ Create a new directory, cd to it, then unzip and untar the archive. For
+ the most part, you'll have to figure out where things go.
+
+ --------------------------------------------------------------------------
+
+ 2.1.5. OS/2
+
+ First, make sure that no previous installations of Junkbuster and / or
+ Privoxy are left on your system. Check that no Junkbuster or Privoxy
+ objects are in your startup folder.
+
+ Then, just double-click the WarpIN self-installing archive, which will
+ guide you through the installation process. A shadow of the Privoxy
+ executable will be placed in your startup folder so it will start
+ automatically whenever OS/2 starts.
+
+ The directory you choose to install Privoxy into will contain all of the
+ configuration files.
+
+ --------------------------------------------------------------------------
+
+ 2.1.6. Mac OSX
+
+ Unzip the downloaded file (you can either double-click on the file from
+ the finder, or from the desktop if you downloaded it there). Then,
+ double-click on the package installer icon named Privoxy.pkg and follow
+ the installation process. Privoxy will be installed in the folder
+ /Library/Privoxy. It will start automatically whenever you start up. To
+ prevent it from starting automatically, remove or rename the folder
+ /Library/StartupItems/Privoxy.
+
+ To start Privoxy by hand, double-click on StartPrivoxy.command in the
+ /Library/Privoxy folder. Or, type this command in the Terminal:
+
+ /Library/Privoxy/StartPrivoxy.command
+
+
+ You will be prompted for the administrator password.
+
+ --------------------------------------------------------------------------
+
+ 2.1.7. AmigaOS
+
+ Copy and then unpack the lha archive to a suitable location. All necessary
+ files will be installed into Privoxy directory, including all
+ configuration and log files. To uninstall, just remove this directory.
+
+ --------------------------------------------------------------------------
+
+ 2.1.8. FreeBSD
+
+ Privoxy is part of FreeBSD's Ports Collection, you can build and install
+ it with cd /usr/ports/www/privoxy; make install clean.
+
+ If you don't use the ports, you can fetch and install the package with
+ pkg_add -r privoxy.
+
+ The port skeleton and the package can also be downloaded from the File
+ Release Page, but there's no reason to use them unless you're interested
+ in the beta releases which are only available there.
+
+ --------------------------------------------------------------------------
+
+ 2.1.9. Gentoo
+
+ Gentoo source packages (Ebuilds) for Privoxy are contained in the Gentoo
+ Portage Tree (they are not on the download page, but there is a Gentoo
+ section, where you can see when a new Privoxy Version is added to the
+ Portage Tree).
+
+ Before installing Privoxy under Gentoo just do first emerge rsync to get
+ the latest changes from the Portage tree. With emerge privoxy you install
+ the latest version.
+
+ Configuration files are in /etc/privoxy, the documentation is in
+ /usr/share/doc/privoxy-3.0.8 and the Log directory is in /var/log/privoxy.
+
+ --------------------------------------------------------------------------
+
+ 2.2. Building from Source
+
+ The most convenient way to obtain the Privoxy sources is to download the
+ source tarball from our project download page.
+
+ If you like to live on the bleeding edge and are not afraid of using
+ possibly unstable development versions, you can check out the
+ up-to-the-minute version directly from the CVS repository.
+
+ To build Privoxy from source, autoconf, GNU make (gmake), and, of course,
+ a C compiler like gcc are required.
+
+ When building from a source tarball, first unpack the source:
+
+ tar xzvf privoxy-3.0.8-src* [.tgz or .tar.gz]
+ cd privoxy-3.0.8
+
+ For retrieving the current CVS sources, you'll need a CVS client
+ installed. Note that sources from CVS are typically development quality,
+ and may not be stable, or well tested. To download CVS source, check the
+ Sourceforge documentation, which might give commands like:
+
+ cvs -d:pserver:anonymous@ijbswa.cvs.sourceforge.net:/cvsroot/ijbswa login
+ cvs -z3 -d:pserver:anonymous@ijbswa.cvs.sourceforge.net:/cvsroot/ijbswa co current
+ cd current
+
+ This will create a directory named current/, which will contain the source
+ tree.
+
+ You can also check out any Privoxy "branch", just exchange the current
+ name with the wanted branch name (Example: v_3_0_branch for the 3.0 cvs
+ tree).
+
+ It is also strongly recommended to not run Privoxy as root. You should
+ configure/install/run Privoxy as an unprivileged user, preferably by
+ creating a "privoxy" user and group just for this purpose. See your local
+ documentation for the correct command line to do add new users and groups
+ (something like adduser, but the command syntax may vary from platform to
+ platform).
+
+ /etc/passwd might then look like:
+
+ privoxy:*:7777:7777:privoxy proxy:/no/home:/no/shell
+
+ And then /etc/group, like:
+
+ privoxy:*:7777:
+
+ Some binary packages may do this for you.
+
+ Then, to build from either unpacked tarball or CVS source:
+
+ autoheader
+ autoconf
+ ./configure # (--help to see options)
+ make # (the make from GNU, sometimes called gmake)
+ su # Possibly required
+ make -n install # (to see where all the files will go)
+ make -s install # (to really install, -s to silence output)
+
+ Using GNU make, you can have the first four steps automatically done for
+ you by just typing:
+
+ make
+
+ in the freshly downloaded or unpacked source directory.
+
+ To build an executable with security enhanced features so that users
+ cannot easily bypass the proxy (e.g. "Go There Anyway"), or alter their
+ own configurations, configure like this:
+
+ ./configure --disable-toggle --disable-editor --disable-force
+
+ Then build as above. In Privoxy 3.0.7 and later, all of these options can
+ also be disabled through the configuration file.
+
+ WARNING: If installing as root, the install will fail unless a non-root
+ user or group is specified, or a privoxy user and group already exist on
+ the system. If a non-root user is specified, and no group, then the
+ installation will try to also use a group of the same name as "user". If a
+ group is specified (and no user), then the support files will be installed
+ as writable by that group, and owned by the user running the installation.
+
+ configure accepts --with-user and --with-group options for setting user
+ and group ownership of the configuration files (which need to be writable
+ by the daemon). The specified user must already exist. When starting
+ Privoxy, it must be run as this same user to insure write access to
+ configuration and log files!
+
+ Alternately, you can specify user and group on the make command line, but
+ be sure both already exist:
+
+ make -s install USER=privoxy GROUP=privoxy
+
+ The default installation path for make install is /usr/local. This may of
+ course be customized with the various ./configure path options. If you are
+ doing an install to anywhere besides /usr/local, be sure to set the
+ appropriate paths with the correct configure options (./configure --help).
+ Non-privileged users must of course have write access permissions to
+ wherever the target installation is going.
+
+ If you do install to /usr/local, the install will use
+ sysconfdir=$prefix/etc/privoxy by default. All other destinations, and the
+ direct usage of --sysconfdir flag behave like normal, i.e. will not add
+ the extra privoxy directory. This is for a safer install, as there may
+ already exist another program that uses a file with the "config" name, and
+ thus makes /usr/local/etc cleaner.
+
+ If installing to /usr/local, the documentation will go by default to
+ $prefix/share/doc. But if this directory doesn't exist, it will then try
+ $prefix/doc and install there before creating a new $prefix/share/doc just
+ for Privoxy.
+
+ Again, if the installs goes to /usr/local, the localstatedir (ie: var/)
+ will default to /var instead of $prefix/var so the logs will go to
+ /var/log/privoxy/, and the pid file will be created in
+ /var/run/privoxy.pid.
+
+ make install will attempt to set the correct values in config (main
+ configuration file). You should check this to make sure all values are
+ correct. If appropriate, an init script will be installed, but it is up to
+ the user to determine how and where to start Privoxy. The init script
+ should be checked for correct paths and values, if anything other than a
+ default install is done.
+
+ If install finds previous versions of local configuration files, most of
+ these will not be overwritten, and the new ones will be installed with a
+ "new" extension. default.action, default.filter, and standard.action will
+ be overwritten. You will then need to manually update the other installed
+ configuration files as needed. The default template files will be
+ overwritten. If you have customized, local templates, these should be
+ stored safely in a separate directory and defined in config by the
+ "templdir" directive. It is of course wise to always back-up any important
+ configuration files "just in case". If a previous version of Privoxy is
+ already running, you will have to restart it manually.
+
+ For more detailed instructions on how to build Redhat RPMs, Windows
+ self-extracting installers, building on platforms with special
+ requirements etc, please consult the developer manual.
+
+ --------------------------------------------------------------------------
+
+ 2.3. Keeping your Installation Up-to-Date
+
+ As user feedback comes in and development continues, we will make updated
+ versions of both the main actions file (as a separate package) and the
+ software itself (including the actions file) available for download.
+
+ If you wish to receive an email notification whenever we release updates
+ of Privoxy or the actions file, subscribe to our announce mailing list,
+ ijbswa-announce@lists.sourceforge.net.
+
+ In order not to lose your personal changes and adjustments when updating
+ to the latest default.action file we strongly recommend that you use
+ user.action and user.filter for your local customizations of Privoxy. See
+ the Chapter on actions files for details.
+
+ --------------------------------------------------------------------------
+
+3. What's New in this Release
+
+ There are many improvements and new features since Privoxy 3.0.6, the last
+ stable release:
+
+ * Two new actions server-header-tagger and client-header-tagger that can
+ be used to create arbitrary "tags" based on client and server headers.
+ These "tags" can then subsequently be used to control the other
+ actions used for the current request, greatly increasing Privoxy's
+ flexibility and selectivity. See tag patterns for more information on
+ tags.
+
+ * Header filtering is done with dedicated header filters now. As a
+ result the actions "filter-client-headers" and "filter-server-headers"
+ that were introduced with Privoxy 3.0.5 to apply content filters to
+ the headers have been removed. See the new actions
+ server-header-filter and client-header-filter for details.
+
+ * There are four new options for the main config file:
+
+ * allow-cgi-request-crunching which allows requests for Privoxy's
+ internal CGI pages to be blocked, redirected or (un)trusted like
+ ordinary requests.
+
+ * split-large-forms that will work around a browser bug that caused
+ IE6 and IE7 to ignore the Submit button on the Privoxy's
+ edit-actions-for-url CGI page.
+
+ * accept-intercepted-requests which allows to combine Privoxy with
+ any packet filter to create an intercepting proxy for HTTP/1.1
+ requests (and for HTTP/1.0 requests with Host header set). This
+ means clients can be forced to use Privoxy even if their proxy
+ settings are configured differently.
+
+ * templdir to designate an alternate location for Privoxy's locally
+ customized CGI templates so that these are not overwritten during
+ upgrades.
+
+ * A new command line option --pre-chroot-nslookup hostname to initialize
+ the resolver library before chroot'ing. On some systems this reduces
+ the number of files that must be copied into the chroot tree. (Patch
+ provided by Stephen Gildea)
+
+ * The forward-override action allows changing of the forwarding settings
+ through the actions files. Combined with tags, this allows to choose
+ the forwarder based on client headers like the User-Agent, or the
+ request origin.
+
+ * The redirect action can now use regular expression substitutions
+ against the original URL.
+
+ * zlib support is now available as a compile time option to filter
+ compressed content. Patch provided by Wil Mahan.
+
+ * Improve various filters, and add new ones.
+
+ * Include support for RFC 3253 so that Subversion works with Privoxy.
+ Patch provided by Petr Kadlec.
+
+ * Logging can be completely turned off by not specifying a logfile
+ directive.
+
+ * A number of improvements to Privoxy's internal CGI pages, including
+ the use of favicons for error and control pages.
+
+ * Many bugfixes, memory leaks addressed, code improvements, and logging
+ improvements.
+
+ For a more detailed list of changes please have a look at the ChangeLog.
+
+ --------------------------------------------------------------------------
+
+ 3.1. Note to Upgraders
+
+ A quick list of things to be aware of before upgrading from earlier
+ versions of Privoxy:
+
+ * The recommended way to upgrade Privoxy is to backup your old
+ configuration files, install the new ones, verify that Privoxy is
+ working correctly and finally merge back your changes using diff and
+ maybe patch.
+
+ There are a number of new features in each Privoxy release and most of
+ them have to be explicitly enabled in the configuration files. Old
+ configuration files obviously don't do that and due to syntax changes
+ using old configuration files with a new Privoxy isn't always possible
+ anyway.
+
+ * Note that some installers remove earlier versions completely,
+ including configuration files, therefore you should really save any
+ important configuration files!
+
+ * On the other hand, other installers don't overwrite existing
+ configuration files, thinking you will want to do that yourself.
+
+ * standard.action now only includes the enabled actions. Not all actions
+ as before.
+
+ * In the default configuration only fatal errors are logged now. You can
+ change that in the debug section of the configuration file. You may
+ also want to enable more verbose logging until you verified that the
+ new Privoxy version is working as expected.
+
+ * Three other config file settings are now off by default:
+ enable-remote-toggle, enable-remote-http-toggle, and
+ enable-edit-actions. If you use or want these, you will need to
+ explicitly enable them, and be aware of the security issues involved.
+
+ * The "filter-client-headers" and "filter-server-headers" actions that
+ were introduced with Privoxy 3.0.5 to apply content filters to the
+ headers have been removed and replaced with new actions. See the
+ What's New section above.
+
+ --------------------------------------------------------------------------
+
+4. Quickstart to Using Privoxy
+
+ * Install Privoxy. See the Installation Section below for platform
+ specific information.
+
+ * Advanced users and those who want to offer Privoxy service to more
+ than just their local machine should check the main config file,
+ especially the security-relevant options. These are off by default.
+
+ * Start Privoxy, if the installation program has not done this already
+ (may vary according to platform). See the section Starting Privoxy.
+
+ * Set your browser to use Privoxy as HTTP and HTTPS (SSL) proxy by
+ setting the proxy configuration for address of 127.0.0.1 and port
+ 8118. DO NOT activate proxying for FTP or any protocols besides HTTP
+ and HTTPS (SSL) unless you intend to prevent your browser from using
+ these protocols.
+
+ * Flush your browser's disk and memory caches, to remove any cached ad
+ images. If using Privoxy to manage cookies, you should remove any
+ currently stored cookies too.
+
+ * A default installation should provide a reasonable starting point for
+ most. There will undoubtedly be occasions where you will want to
+ adjust the configuration, but that can be dealt with as the need
+ arises. Little to no initial configuration is required in most cases,
+ you may want to enable the web-based action editor though. Be sure to
+ read the warnings first.
+
+ See the Configuration section for more configuration options, and how
+ to customize your installation. You might also want to look at the
+ next section for a quick introduction to how Privoxy blocks ads and
+ banners.
+
+ * If you experience ads that slip through, innocent images that are
+ blocked, or otherwise feel the need to fine-tune Privoxy's behavior,
+ take a look at the actions files. As a quick start, you might find the
+ richly commented examples helpful. You can also view and edit the
+ actions files through the web-based user interface. The Appendix
+ "Troubleshooting: Anatomy of an Action" has hints on how to understand
+ and debug actions that "misbehave".
+
+ * Please see the section Contacting the Developers on how to report
+ bugs, problems with websites or to get help.
+
+ * Now enjoy surfing with enhanced control, comfort and privacy!
+
+ --------------------------------------------------------------------------
+
+ 4.1. Quickstart to Ad Blocking
+
+ Ad blocking is but one of Privoxy's array of features. Many of these
+ features are for the technically minded advanced user. But, ad and banner
+ blocking is surely common ground for everybody.
+
+ This section will provide a quick summary of ad blocking so you can get up
+ to speed quickly without having to read the more extensive information
+ provided below, though this is highly recommended.
+
+ First a bit of a warning ... blocking ads is much like blocking SPAM: the
+ more aggressive you are about it, the more likely you are to block things
+ that were not intended. And the more likely that some things may not work
+ as intended. So there is a trade off here. If you want extreme ad free
+ browsing, be prepared to deal with more "problem" sites, and to spend more
+ time adjusting the configuration to solve these unintended consequences.
+ In short, there is not an easy way to eliminate all ads. Either take the
+ easy way and settle for most ads blocked with the default configuration,
+ or jump in and tweak it for your personal surfing habits and preferences.
+
+ Secondly, a brief explanation of Privoxy's "actions". "Actions" in this
+ context, are the directives we use to tell Privoxy to perform some task
+ relating to HTTP transactions (i.e. web browsing). We tell Privoxy to take
+ some "action". Each action has a unique name and function. While there are
+ many potential actions in Privoxy's arsenal, only a few are used for ad
+ blocking. Actions, and action configuration files, are explained in depth
+ below.
+
+ Actions are specified in Privoxy's configuration, followed by one or more
+ URLs to which the action should apply. URLs can actually be URL type
+ patterns that use wildcards so they can apply potentially to a range of
+ similar URLs. The actions, together with the URL patterns are called a
+ section.
+
+ When you connect to a website, the full URL will either match one or more
+ of the sections as defined in Privoxy's configuration, or not. If so, then
+ Privoxy will perform the respective actions. If not, then nothing special
+ happens. Furthermore, web pages may contain embedded, secondary URLs that
+ your web browser will use to load additional components of the page, as it
+ parses the original page's HTML content. An ad image for instance, is just
+ an URL embedded in the page somewhere. The image itself may be on the same
+ server, or a server somewhere else on the Internet. Complex web pages will
+ have many such embedded URLs. Privoxy can deal with each URL individually,
+ so, for instance, the main page text is not touched, but images from
+ such-and-such server are blocked.
+
+ The most important actions for basic ad blocking are: block,
+ handle-as-image, handle-as-empty-document,and set-image-blocker:
+
+ * block - this is perhaps the single most used action, and is
+ particularly important for ad blocking. This action stops any contact
+ between your browser and any URL patterns that match this action's
+ configuration. It can be used for blocking ads, but also anything that
+ is determined to be unwanted. By itself, it simply stops any
+ communication with the remote server and sends Privoxy's own built-in
+ BLOCKED page instead to let you now what has happened (with some
+ exceptions, see below).
+
+ * handle-as-image - tells Privoxy to treat this URL as an image.
+ Privoxy's default configuration already does this for all common image
+ types (e.g. GIF), but there are many situations where this is not so
+ easy to determine. So we'll force it in these cases. This is
+ particularly important for ad blocking, since only if we know that
+ it's an image of some kind, can we replace it with an image of our
+ choosing, instead of the Privoxy BLOCKED page (which would only result
+ in a "broken image" icon). There are some limitations to this though.
+ For instance, you can't just brute-force an image substitution for an
+ entire HTML page in most situations.
+
+ * handle-as-empty-document - sends an empty document instead of
+ Privoxy's normal BLOCKED HTML page. This is useful for file types that
+ are neither HTML nor images, such as blocking JavaScript files.
+
+ * set-image-blocker - tells Privoxy what to display in place of an ad
+ image that has hit a block rule. For this to come into play, the URL
+ must match a block action somewhere in the configuration, and, it must
+ also match an handle-as-image action.
+
+ The configuration options on what to display instead of the ad are:
+
+ pattern - a checkerboard pattern, so that an ad replacement is
+ obvious. This is the default.
+
+ blank - A very small empty GIF image is displayed. This is the
+ so-called "invisible" configuration option.
+
+ http://<URL> - A redirect to any image anywhere of the user's
+ choosing (advanced usage).
+
+ Advanced users will eventually want to explore Privoxy filters as well.
+ Filters are very different from blocks. A "block" blocks a site, page, or
+ unwanted contented. Filters are a way of filtering or modifying what is
+ actually on the page. An example filter usage: a text replacement of
+ "no-no" for "nasty-word". That is a very simple example. This process can
+ be used for ad blocking, but it is more in the realm of advanced usage and
+ has some pitfalls to be wary off.
+
+ The quickest way to adjust any of these settings is with your browser
+ through the special Privoxy editor at
+ http://config.privoxy.org/show-status (shortcut: http://p.p/show-status).
+ This is an internal page, and does not require Internet access.
+
+ Note that as of Privoxy 3.0.7 beta the action editor is disabled by
+ default. Check the enable-edit-actions section in the configuration file
+ to learn why and in which cases it's safe to enable again.
+
+ If you decided to enable the action editor, select the appropriate
+ "actions" file, and click "Edit". It is best to put personal or local
+ preferences in user.action since this is not meant to be overwritten
+ during upgrades, and will over-ride the settings in other files. Here you
+ can insert new "actions", and URLs for ad blocking or other purposes, and
+ make other adjustments to the configuration. Privoxy will detect these
+ changes automatically.
+
+ A quick and simple step by step example:
+
+ * Right click on the ad image to be blocked, then select "Copy Link
+ Location" from the pop-up menu.
+
+ * Set your browser to http://config.privoxy.org/show-status
+
+ * Find user.action in the top section, and click on "Edit":
+
+ Figure 1. Actions Files in Use
+
+ * You should have a section with only block listed under "Actions:". If
+ not, click a "Insert new section below" button, and in the new section
+ that just appeared, click the Edit button right under the word
+ "Actions:". This will bring up a list of all actions. Find block near
+ the top, and click in the "Enabled" column, then "Submit" just below
+ the list.
+
+ * Now, in the block actions section, click the "Add" button, and paste
+ the URL the browser got from "Copy Link Location". Remove the http://
+ at the beginning of the URL. Then, click "Submit" (or "OK" if in a
+ pop-up window).
+
+ * Now go back to the original page, and press SHIFT-Reload (or flush all
+ browser caches). The image should be gone now.
+
+ This is a very crude and simple example. There might be good reasons to
+ use a wildcard pattern match to include potentially similar images from
+ the same site. For a more extensive explanation of "patterns", and the
+ entire actions concept, see the Actions section.
+
+ For advanced users who want to hand edit their config files, you might
+ want to now go to the Actions Files Tutorial. The ideas explained therein
+ also apply to the web-based editor.
+
+ There are also various filters that can be used for ad blocking (filters
+ are a special subset of actions). These fall into the "advanced" usage
+ category, and are explained in depth in later sections.
+
+ --------------------------------------------------------------------------
+
+5. Starting Privoxy
+
+ Before launching Privoxy for the first time, you will want to configure
+ your browser(s) to use Privoxy as a HTTP and HTTPS (SSL) proxy. The
+ default is 127.0.0.1 (or localhost) for the proxy address, and port 8118
+ (earlier versions used port 8000). This is the one configuration step that
+ must be done!
+
+ Please note that Privoxy can only proxy HTTP and HTTPS traffic. It will
+ not work with FTP or other protocols.
+
+ Figure 2. Proxy Configuration Showing Mozilla/Netscape HTTP and HTTPS
+ (SSL) Settings
+
+ With Firefox, this is typically set under:
+
+ Tools -> Options -> Advanced -> Network ->Connection -> Settings
+
+
+ Or optionally on some platforms:
+
+ Edit -> Preferences -> General -> Connection Settings -> Manual Proxy
+ Configuration
+
+
+ With Netscape (and Mozilla), this can be set under:
+
+ Edit -> Preferences -> Advanced -> Proxies -> HTTP Proxy
+
+
+ For Internet Explorer v.5-7:
+
+ Tools -> Internet Options -> Connections -> LAN Settings
+
+ Then, check "Use Proxy" and fill in the appropriate info (Address:
+ 127.0.0.1, Port: 8118). Include HTTPS (SSL), if you want HTTPS proxy
+ support too (sometimes labeled "Secure"). Make sure any checkboxes like
+ "Use the same proxy server for all protocols" is UNCHECKED. You want only
+ HTTP and HTTPS (SSL)!
+
+ Figure 3. Proxy Configuration Showing Internet Explorer HTTP and HTTPS
+ (Secure) Settings
+
+ After doing this, flush your browser's disk and memory caches to force a
+ re-reading of all pages and to get rid of any ads that may be cached.
+ Remove any cookies, if you want Privoxy to manage that. You are now ready
+ to start enjoying the benefits of using Privoxy!
+
+ Privoxy itself is typically started by specifying the main configuration
+ file to be used on the command line. If no configuration file is specified
+ on the command line, Privoxy will look for a file named config in the
+ current directory. Except on Win32 where it will try config.txt.
+
+ --------------------------------------------------------------------------
+
+ 5.1. Red Hat and Fedora
+
+ A default Red Hat installation may not start Privoxy upon boot. It will
+ use the file /etc/privoxy/config as its main configuration file.
+
+ # /etc/rc.d/init.d/privoxy start
+
+ Or ...
+
+ # service privoxy start
+
+ --------------------------------------------------------------------------
+
+ 5.2. Debian
+
+ We use a script. Note that Debian typically starts Privoxy upon booting
+ per default. It will use the file /etc/privoxy/config as its main
+ configuration file.
+
+ # /etc/init.d/privoxy start
+
+ --------------------------------------------------------------------------
+
+ 5.3. Windows
+
+ Click on the Privoxy Icon to start Privoxy. If no configuration file is
+ specified on the command line, Privoxy will look for a file named
+ config.txt. Note that Windows will automatically start Privoxy when the
+ system starts if you chose that option when installing.
+
+ Privoxy can run with full Windows service functionality. On Windows only,
+ the Privoxy program has two new command line arguments to install and
+ uninstall Privoxy as a service. See the Windows Installation instructions
+ for details.
+
+ --------------------------------------------------------------------------
+
+ 5.4. Solaris, NetBSD, FreeBSD, HP-UX and others
+
+ Example Unix startup command:
+
+ # /usr/sbin/privoxy /etc/privoxy/config
+
+ --------------------------------------------------------------------------
+
+ 5.5. OS/2
+
+ During installation, Privoxy is configured to start automatically when the
+ system restarts. You can start it manually by double-clicking on the
+ Privoxy icon in the Privoxy folder.
+
+ --------------------------------------------------------------------------
+
+ 5.6. Mac OSX
+
+ During installation, Privoxy is configured to start automatically when the
+ system restarts. To start Privoxy manually, double-click on the
+ StartPrivoxy.command icon in the /Library/Privoxy folder. Or, type this
+ command in the Terminal:
+
+ /Library/Privoxy/StartPrivoxy.command
+
+
+ You will be prompted for the administrator password.
+
+ --------------------------------------------------------------------------
+
+ 5.7. AmigaOS
+
+ Start Privoxy (with RUN <>NIL:) in your startnet script (AmiTCP), in
+ s:user-startup (RoadShow), as startup program in your startup script
+ (Genesis), or as startup action (Miami and MiamiDx). Privoxy will
+ automatically quit when you quit your TCP/IP stack (just ignore the
+ harmless warning your TCP/IP stack may display that Privoxy is still
+ running).
+
+ --------------------------------------------------------------------------
+
+ 5.8. Gentoo
+
+ A script is again used. It will use the file /etc/privoxy/config as its
+ main configuration file.
+
+ /etc/init.d/privoxy start
+
+
+ Note that Privoxy is not automatically started at boot time by default.
+ You can change this with the rc-update command.
+
+ rc-update add privoxy default
+
+
+ --------------------------------------------------------------------------
+
+ 5.9. Command Line Options
+
+ Privoxy may be invoked with the following command-line options:
+
+ * --version
+
+ Print version info and exit. Unix only.
+
+ * --help
+
+ Print short usage info and exit. Unix only.
+
+ * --no-daemon
+
+ Don't become a daemon, i.e. don't fork and become process group
+ leader, and don't detach from controlling tty. Unix only.
+
+ * --pidfile FILE
+
+ On startup, write the process ID to FILE. Delete the FILE on exit.
+ Failure to create or delete the FILE is non-fatal. If no FILE option
+ is given, no PID file will be used. Unix only.
+
+ * --user USER[.GROUP]
+
+ After (optionally) writing the PID file, assume the user ID of USER,
+ and if included the GID of GROUP. Exit if the privileges are not
+ sufficient to do so. Unix only.
+
+ * --chroot
+
+ Before changing to the user ID given in the --user option, chroot to
+ that user's home directory, i.e. make the kernel pretend to the
+ Privoxy process that the directory tree starts there. If set up
+ carefully, this can limit the impact of possible vulnerabilities in
+ Privoxy to the files contained in that hierarchy. Unix only.
+
+ * --pre-chroot-nslookup hostname
+
+ Specifies a hostname to look up before doing a chroot. On some
+ systems, initializing the resolver library involves reading config
+ files from /etc and/or loading additional shared libraries from /lib.
+ On these systems, doing a hostname lookup before the chroot reduces
+ the number of files that must be copied into the chroot tree.
+
+ For fastest startup speed, a good value is a hostname that is not in
+ /etc/hosts but that your local name server (listed in
+ /etc/resolv.conf) can resolve without recursion (that is, without
+ having to ask any other name servers). The hostname need not exist,
+ but if it doesn't, an error message (which can be ignored) will be
+ output.
+
+ * configfile
+
+ If no configfile is included on the command line, Privoxy will look
+ for a file named "config" in the current directory (except on Win32
+ where it will look for "config.txt" instead). Specify full path to
+ avoid confusion. If no config file is found, Privoxy will fail to
+ start.
+
+ On MS Windows only there are two additional command-line options to allow
+ Privoxy to install and run as a service. See the Window Installation
+ section for details.
+
+ --------------------------------------------------------------------------
+
+6. Privoxy Configuration
+
+ All Privoxy configuration is stored in text files. These files can be
+ edited with a text editor. Many important aspects of Privoxy can also be
+ controlled easily with a web browser.
+
+ --------------------------------------------------------------------------
+
+ 6.1. Controlling Privoxy with Your Web Browser
+
+ Privoxy's user interface can be reached through the special URL
+ http://config.privoxy.org/ (shortcut: http://p.p/), which is a built-in
+ page and works without Internet access. You will see the following
+ section:
+
+
+
+ Privoxy Menu
+
+ sB View & change the current configuration
+
+ sB View the source code version numbers
+
+ sB View the request headers.
+
+ sB Look up which actions apply to a URL and why
+
+ sB Toggle Privoxy on or off
+
+ sB Documentation
+
+
+ This should be self-explanatory. Note the first item leads to an editor
+ for the actions files, which is where the ad, banner, cookie, and URL
+ blocking magic is configured as well as other advanced features of
+ Privoxy. This is an easy way to adjust various aspects of Privoxy
+ configuration. The actions file, and other configuration files, are
+ explained in detail below.
+
+ "Toggle Privoxy On or Off" is handy for sites that might have problems
+ with your current actions and filters. You can in fact use it as a test to
+ see whether it is Privoxy causing the problem or not. Privoxy continues to
+ run as a proxy in this case, but all manipulation is disabled, i.e.
+ Privoxy acts like a normal forwarding proxy. There is even a toggle
+ Bookmarklet offered, so that you can toggle Privoxy with one click from
+ your browser.
+
+ Note that several of the features described above are disabled by default
+ in Privoxy 3.0.7 beta and later. Check the configuration file to learn why
+ and in which cases it's safe to enable them again.
+
+ --------------------------------------------------------------------------
+
+ 6.2. Configuration Files Overview
+
+ For Unix, *BSD and Linux, all configuration files are located in
+ /etc/privoxy/ by default. For MS Windows, OS/2, and AmigaOS these are all
+ in the same directory as the Privoxy executable.
+
+ The installed defaults provide a reasonable starting point, though some
+ settings may be aggressive by some standards. For the time being, the
+ principle configuration files are:
+
+ * The main configuration file is named config on Linux, Unix, BSD, OS/2,
+ and AmigaOS and config.txt on Windows. This is a required file.
+
+ * default.action (the main actions file) is used to define which
+ "actions" relating to banner-blocking, images, pop-ups, content
+ modification, cookie handling etc should be applied by default. It
+ also defines many exceptions (both positive and negative) from this
+ default set of actions that enable Privoxy to selectively eliminate
+ the junk, and only the junk, on as many websites as possible.
+
+ Multiple actions files may be defined in config. These are processed
+ in the order they are defined. Local customizations and locally
+ preferred exceptions to the default policies as defined in
+ default.action (which you will most probably want to define sooner or
+ later) are probably best applied in user.action, where you can
+ preserve them across upgrades. standard.action is only for Privoxy's
+ internal use.
+
+ There is also a web based editor that can be accessed from
+ http://config.privoxy.org/show-status (Shortcut:
+ http://p.p/show-status) for the various actions files.
+
+ * "Filter files" (the filter file) can be used to re-write the raw page
+ content, including viewable text as well as embedded HTML and
+ JavaScript, and whatever else lurks on any given web page. The
+ filtering jobs are only pre-defined here; whether to apply them or not
+ is up to the actions files. default.filter includes various filters
+ made available for use by the developers. Some are much more intrusive
+ than others, and all should be used with caution. You may define
+ additional filter files in config as you can with actions files. We
+ suggest user.filter for any locally defined filters or customizations.
+
+ The syntax of the configuration and filter files may change between
+ different Privoxy versions, unfortunately some enhancements cost backwards
+ compatibility.
+
+ All files use the "#" character to denote a comment (the rest of the line
+ will be ignored) and understand line continuation through placing a
+ backslash ("\") as the very last character in a line. If the # is preceded
+ by a backslash, it looses its special function. Placing a # in front of an
+ otherwise valid configuration line to prevent it from being interpreted is
+ called "commenting out" that line. Blank lines are ignored.
+
+ The actions files and filter files can use Perl style regular expressions
+ for maximum flexibility.
+
+ After making any changes, there is no need to restart Privoxy in order for
+ the changes to take effect. Privoxy detects such changes automatically.
+ Note, however, that it may take one or two additional requests for the
+ change to take effect. When changing the listening address of Privoxy,
+ these "wake up" requests must obviously be sent to the old listening
+ address.
+
+ --------------------------------------------------------------------------
+
+7. The Main Configuration File
+
+ Again, the main configuration file is named config on Linux/Unix/BSD and
+ OS/2, and config.txt 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:
+
+ confdir /etc/privoxy
+
+ Assigns the value /etc/privoxy to the option confdir and thus indicates
+ that the configuration directory is named "/etc/privoxy/".
+
+ All options in the config file except for confdir and logdir are optional.
+ Watch out in the below description for what happens if you leave them
+ unset.
+
+ The main config file controls all aspects of Privoxy's operation that are
+ not location dependent (i.e. they apply universally, no matter where you
+ may be surfing).
+
+ --------------------------------------------------------------------------
+
+ 7.1. Local Set-up Documentation
+
+ If you intend to operate Privoxy for more users than just yourself, it
+ might be a good idea to let them know how to reach you, what you block and
+ why you do that, your policies, etc.
+
+ --------------------------------------------------------------------------
+
+ 7.1.1. user-manual
+
+ Specifies:
+
+ Location of the Privoxy User Manual.
+
+ Type of value:
+
+ A fully qualified URI
+
+ Default value:
+
+ Unset
+
+ Effect if unset:
+
+ http://www.privoxy.org/version/user-manual/ will be used, where
+ version is the Privoxy version.
+
+ Notes:
+
+ The User Manual URI is the single best source of information on
+ Privoxy, and is used for help links from some of the internal CGI
+ pages. The manual itself is normally packaged with the binary
+ distributions, so you probably want to set this to a locally
+ installed copy.
+
+ Examples:
+
+ The best all purpose solution is simply to put the full local PATH
+ to where the User Manual is located:
+
+ user-manual /usr/share/doc/privoxy/user-manual
+
+ The User Manual is then available to anyone with access to
+ Privoxy, by following the built-in URL:
+ http://config.privoxy.org/user-manual/ (or the shortcut:
+ http://p.p/user-manual/).
+
+ If the documentation is not on the local system, it can be
+ accessed from a remote server, as:
+
+ user-manual http://example.com/privoxy/user-manual/
+
+ +---------------------------------------------------------+
+ | Warning |
+ |---------------------------------------------------------|
+ | If set, this option should be the first option in the |
+ | config file, because it is used while the config file |
+ | is being read on start-up. |
+ +---------------------------------------------------------+
+
+ --------------------------------------------------------------------------
+
+ 7.1.2. trust-info-url
+
+ Specifies:
+
+ A URL to be displayed in the error page that users will see if
+ access to an untrusted page is denied.
+
+ Type of value:
+
+ URL
+
+ Default value:
+
+ Two example URLs are provided
+
+ Effect if unset:
+
+ No links are displayed on the "untrusted" error page.
+
+ Notes:
+
+ The value of this option only matters if the experimental trust
+ mechanism has been activated. (See trustfile below.)
+
+ If you use the trust mechanism, it is a good idea to write up some
+ on-line documentation about your trust policy and to specify the
+ URL(s) here. Use multiple times for multiple URLs.
+
+ The URL(s) should be added to the trustfile as well, so users
+ don't end up locked out from the information on why they were
+ locked out in the first place!
+
+ --------------------------------------------------------------------------
+
+ 7.1.3. admin-address
+
+ Specifies:
+
+ An email address to reach the Privoxy administrator.
+
+ Type of value:
+
+ Email address
+
+ Default value:
+
+ Unset
+
+ Effect if unset:
+
+ No email address is displayed on error pages and the CGI user
+ interface.
+
+ Notes:
+
+ If both admin-address and proxy-info-url are unset, the whole
+ "Local Privoxy Support" box on all generated pages will not be
+ shown.
+
+ --------------------------------------------------------------------------
+
+ 7.1.4. proxy-info-url
+
+ Specifies:
+
+ A URL to documentation about the local Privoxy setup,
+ configuration or policies.
+
+ Type of value:
+
+ URL
+
+ Default value:
+
+ Unset
+
+ Effect if unset:
+
+ No link to local documentation is displayed on error pages and the
+ CGI user interface.
+
+ Notes:
+
+ If both admin-address and proxy-info-url are unset, the whole
+ "Local Privoxy Support" box on all generated pages will not be
+ shown.
+
+ This URL shouldn't be blocked ;-)
+
+ --------------------------------------------------------------------------
+
+ 7.2. Configuration and Log File Locations
+
+ Privoxy can (and normally does) use a number of other files for additional
+ configuration, help and logging. This section of the configuration file
+ tells Privoxy where to find those other files.
+
+ The user running Privoxy, must have read permission for all configuration
+ files, and write permission to any files that would be modified, such as
+ log files and actions files.
+
+ --------------------------------------------------------------------------
+
+ 7.2.1. confdir
+
+ Specifies:
+
+ The directory where the other configuration files are located.
+
+ Type of value:
+
+ Path name
+
+ Default value:
+
+ /etc/privoxy (Unix) or Privoxy installation dir (Windows)
+
+ Effect if unset:
+
+ Mandatory
+
+ Notes:
+
+ No trailing "/", please.
+
+ --------------------------------------------------------------------------
+
+ 7.2.2. templdir
+
+ Specifies:
+
+ An alternative directory where the templates are loaded from.
+
+ Type of value:
+
+ Path name
+
+ Default value:
+
+ unset
+
+ Effect if unset:
+
+ The templates are assumed to be located in confdir/template.
+
+ Notes:
+
+ Privoxy's original templates are usually overwritten with each
+ update. Use this option to relocate customized templates that
+ should be kept. As template variables might change between
+ updates, you shouldn't expect templates to work with Privoxy
+ releases other than the one they were part of, though.
+
+ --------------------------------------------------------------------------
+
+ 7.2.3. logdir
+
+ Specifies:
+
+ The directory where all logging takes place (i.e. where logfile
+ and jarfile are located).
+
+ Type of value:
+
+ Path name
+
+ Default value:
+
+ /var/log/privoxy (Unix) or Privoxy installation dir (Windows)
+
+ Effect if unset:
+
+ Mandatory
+
+ Notes:
+
+ No trailing "/", please.
+
+ --------------------------------------------------------------------------
+
+ 7.2.4. actionsfile
+
+ Specifies:
+
+ The actions file(s) to use
+
+ Type of value:
+
+ Complete file name, relative to confdir
+
+ Default values:
+
+ standard.action # Internal purposes, no editing recommended
+ default.action # Main actions file
+ user.action # User customizations
+
+ Effect if unset:
+
+ No actions are taken at all. More or less neutral proxying.
+
+ Notes:
+
+ Multiple actionsfile lines are permitted, and are in fact
+ recommended!
+
+ The default values include standard.action, which is used for
+ internal purposes and should be loaded, default.action, which is
+ the "main" actions file maintained by the developers, and
+ user.action, where you can make your personal additions.
+
+ Actions files contain all the per site and per URL configuration
+ for ad blocking, cookie management, privacy considerations, etc.
+ There is no point in using Privoxy without at least one actions
+ file.
+
+ Note that since Privoxy 3.0.7, the complete filename, including
+ the ".action" extension has to be specified. The syntax change was
+ necessary to be consistent with the other file options and to
+ allow previously forbidden characters.
+
+ --------------------------------------------------------------------------
+
+ 7.2.5. filterfile
+
+ Specifies:
+
+ The filter file(s) to use
+
+ Type of value:
+
+ File name, relative to confdir
+
+ Default value:
+
+ default.filter (Unix) or default.filter.txt (Windows)
+
+ Effect if unset:
+
+ No textual content filtering takes place, i.e. all +filter{name}
+ actions in the actions files are turned neutral.
+
+ Notes:
+
+ Multiple filterfile lines are permitted.
+
+ The filter files contain content modification rules that use
+ regular expressions. These rules permit powerful changes on the
+ content of Web pages, and optionally the headers as well, e.g.,
+ you could try to disable your favorite JavaScript annoyances,
+ re-write the actual displayed text, or just have some fun playing
+ buzzword bingo with web pages.
+
+ The +filter{name} actions rely on the relevant filter (name) to be
+ defined in a filter file!
+
+ A pre-defined filter file called default.filter that contains a
+ number of useful filters for common problems is included in the
+ distribution. See the section on the filter action for a list.
+
+ It is recommended to place any locally adapted filters into a
+ separate file, such as user.filter.
+
+ --------------------------------------------------------------------------
+
+ 7.2.6. logfile
+
+ Specifies:
+
+ The log file to use
+
+ Type of value:
+
+ File name, relative to logdir
+
+ Default value:
+
+ Unset (commented out). When activated: logfile (Unix) or
+ privoxy.log (Windows).
+
+ Effect if unset:
+
+ No logfile is written.
+
+ Notes:
+
+ The logfile is where all logging and error messages are written.
+ The level of detail and number of messages are set with the debug
+ option (see below). The logfile can be useful for tracking down a
+ problem with Privoxy (e.g., it's not blocking an ad you think it
+ should block) and it can help you to monitor what your browser is
+ doing.
+
+ Depending on the debug options below, the logfile may be a privacy
+ risk if third parties can get access to it. As most users will
+ never look at it, Privoxy 3.0.7 and later only log fatal errors by
+ default.
+
+ For most troubleshooting purposes, you will have to change that,
+ please refer to the debugging section for details.
+
+ 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 "man cron"). For Red Hat based Linux distributions,
+ a logrotate script has been included.
+
+ Any log files must be writable by whatever user Privoxy is being
+ run as (on Unix, default user id is "privoxy").
+
+ --------------------------------------------------------------------------
+
+ 7.2.7. jarfile
+
+ Specifies:
+
+ The file to store intercepted cookies in
+
+ Type of value:
+
+ File name, relative to logdir
+
+ Default value:
+
+ Unset (commented out). When activated: jarfile (Unix) or
+ privoxy.jar (Windows).
+
+ Effect if unset:
+
+ Intercepted cookies are not stored in a dedicated log file.
+
+ Notes:
+
+ The jarfile may grow to ridiculous sizes over time.
+
+ If debug 8 (show header parsing) is enabled, cookies are also
+ written to the logfile with the rest of the headers. Therefore
+ this option isn't very useful and may be removed in future
+ releases. Please report to the developers if you are still using
+ it.
+
+ --------------------------------------------------------------------------
+
+ 7.2.8. trustfile
+
+ Specifies:
+
+ The name of the trust file to use
+
+ Type of value:
+
+ File name, relative to confdir
+
+ Default value:
+
+ Unset (commented out). When activated: trust (Unix) or trust.txt
+ (Windows)
+
+ Effect if unset:
+
+ The entire trust mechanism is disabled.
+
+ Notes:
+
+ The trust mechanism is an experimental feature for building
+ white-lists and should be used with care. It is NOT recommended
+ for the casual user.
+
+ If you specify a trust file, Privoxy will only allow access to
+ sites that are specified in the trustfile. Sites can be listed in
+ one of two ways:
+
+ Prepending a ~ character limits access to this site only (and any
+ sub-paths within this site), e.g. ~www.example.com allows access
+ to ~www.example.com/features/news.html, etc.
+
+ Or, you can designate sites as trusted referrers, by prepending
+ the name with a + character. The effect is that access to
+ untrusted sites will be granted -- but only if a link from this
+ trusted referrer was used to get there. The link target will then
+ be added to the "trustfile" so that future, direct accesses will
+ be granted. Sites added via this mechanism do not become trusted
+ referrers themselves (i.e. they are added with a ~ designation).
+ There is a limit of 512 such entries, after which new entries will
+ not be made.
+
+ If you use the + operator in the trust file, it may grow
+ considerably over time.
+
+ It is recommended that Privoxy be compiled with the
+ --disable-force, --disable-toggle and --disable-editor options, if
+ this feature is to be used.
+
+ Possible applications include limiting Internet access for
+ children.
+
+ --------------------------------------------------------------------------
+
+ 7.3. Debugging
+
+ These options are mainly useful when tracing a problem. Note that you
+ might also want to invoke Privoxy with the --no-daemon command line option
+ when debugging.
+
+ --------------------------------------------------------------------------
+
+ 7.3.1. debug
+
+ Specifies:
+
+ Key values that determine what information gets logged.
+
+ Type of value:
+
+ Integer values
+
+ Default value:
+
+ 0 (i.e.: only fatal errors (that cause Privoxy to exit) are
+ logged)
+
+ Effect if unset:
+
+ Default value is used (see above).
+
+ Notes:
+
+ The available debug levels are:
+
+ debug 1 # log each request destination (and the crunch reason if Privoxy intercepted the request)
+ debug 2 # show each connection status
+ debug 4 # show I/O status
+ debug 8 # show header parsing
+ debug 16 # log all data written to the network into the logfile
+ debug 32 # debug force feature
+ debug 64 # debug regular expression filters
+ debug 128 # debug redirects
+ debug 256 # debug GIF de-animation
+ debug 512 # Common Log Format
+ debug 1024 # debug kill pop-ups
+ debug 2048 # CGI user interface
+ debug 4096 # Startup banner and warnings.
+ debug 8192 # Non-fatal errors
+
+ To select multiple debug levels, you can either add them or use
+ multiple debug lines.
+
+ A debug level of 1 is informative because it will show you each
+ request as it happens. 1, 4096 and 8192 are recommended so that
+ you will notice when things go wrong. The other levels are
+ probably only of interest if you are hunting down a specific
+ problem. They can produce a hell of an output (especially 16).
+
+ Privoxy used to ship with the debug levels recommended above
+ enabled by default, but due to privacy concerns 3.0.7 and later
+ are configured to only log fatal errors.
+
+ If you are used to the more verbose settings, simply enable the
+ debug lines below again.
+
+ If you want to use pure CLF (Common Log Format), you should set
+ "debug 512" ONLY and not enable anything else.
+
+ Privoxy has a hard-coded limit for the length of log messages. If
+ it's reached, messages are logged truncated and marked with "...
+ [too long, truncated]".
+
+ Please don't file any support requests without trying to reproduce
+ the problem with increased debug level first. Once you read the
+ log messages, you may even be able to solve the problem on your
+ own.
+
+ --------------------------------------------------------------------------
+
+ 7.3.2. single-threaded
+
+ Specifies:
+
+ Whether to run only one server thread.
+
+ Type of value:
+
+ None
+
+ Default value:
+
+ Unset
+
+ Effect if unset:
+
+ Multi-threaded (or, where unavailable: forked) operation, i.e. the
+ ability to serve multiple requests simultaneously.
+
+ Notes:
+
+ This option is only there for debugging purposes. It will
+ drastically reduce performance.
+
+ --------------------------------------------------------------------------
+
+ 7.4. Access Control and Security
+
+ This section of the config file controls the security-relevant aspects of
+ Privoxy's configuration.
+
+ --------------------------------------------------------------------------
+
+ 7.4.1. listen-address
+
+ Specifies:
+
+ The IP address and TCP port on which Privoxy will listen for
+ client requests.
+
+ Type of value:
+
+ [IP-Address]:Port
+
+ Default value:
+
+ 127.0.0.1:8118
+
+ Effect if unset:
+
+ Bind to 127.0.0.1 (localhost), port 8118. This is suitable and
+ recommended for home users who run Privoxy on the same machine as
+ their browser.
+
+ Notes:
+
+ You will need to configure your browser(s) to this proxy address
+ and port.
+
+ 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.
+
+ If you leave out the IP address, Privoxy 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 below), and/or a firewall.
+
+ If you open Privoxy to untrusted users, you will also want to make
+ sure that the following actions are disabled: enable-edit-actions
+ and enable-remote-toggle
+
+ Example:
+
+ Suppose you are running Privoxy 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:
+
+ listen-address 192.168.0.1:8118
+
+ --------------------------------------------------------------------------
+
+ 7.4.2. toggle
+
+ Specifies:
+
+ Initial state of "toggle" status
+
+ Type of value:
+
+ 1 or 0
+
+ Default value:
+
+ 1
+
+ Effect if unset:
+
+ Act as if toggled on
+
+ Notes:
+
+ If set to 0, Privoxy will start in "toggled off" mode, i.e. mostly
+ behave like a normal, content-neutral proxy with both ad blocking
+ and content filtering disabled. See enable-remote-toggle below.
+
+ The windows version will only display the toggle icon in the
+ system tray if this option is present.
+
+ --------------------------------------------------------------------------
+
+ 7.4.3. enable-remote-toggle
+
+ Specifies:
+
+ Whether or not the web-based toggle feature may be used
+
+ Type of value:
+
+ 0 or 1
+
+ Default value:
+
+ 0
+
+ Effect if unset:
+
+ The web-based toggle feature is disabled.
+
+ Notes:
+
+ When toggled off, Privoxy mostly acts like a normal,
+ content-neutral proxy, i.e. doesn't block ads or filter content.
+
+ Access to the toggle feature can not be controlled separately by
+ "ACLs" or HTTP authentication, so that everybody who can access
+ Privoxy (see "ACLs" and listen-address above) can toggle it for
+ all users. So this option is not recommended for multi-user
+ environments with untrusted users.
+
+ Note that malicious client side code (e.g Java) is also capable of
+ using this option.
+
+ As a lot of Privoxy users don't read documentation, this feature
+ is disabled by default.
+
+ Note that you must have compiled Privoxy with support for this
+ feature, otherwise this option has no effect.
+
+ --------------------------------------------------------------------------
+
+ 7.4.4. enable-remote-http-toggle
+
+ Specifies:
+
+ Whether or not Privoxy recognizes special HTTP headers to change
+ its behaviour.
+
+ Type of value:
+
+ 0 or 1
+
+ Default value:
+
+ 0
+
+ Effect if unset:
+
+ Privoxy ignores special HTTP headers.
+
+ Notes:
+
+ When toggled on, the client can change Privoxy's behaviour by
+ setting special HTTP headers. Currently the only supported special
+ header is "X-Filter: No", to disable filtering for the ongoing
+ request, even if it is enabled in one of the action files.
+
+ This feature is disabled by default. If you are using Privoxy in a
+ environment with trusted clients, you may enable this feature at
+ your discretion. Note that malicious client side code (e.g Java)
+ is also capable of using this feature.
+
+ This option will be removed in future releases as it has been
+ obsoleted by the more general header taggers.
+
+ --------------------------------------------------------------------------
+
+ 7.4.5. enable-edit-actions
+
+ Specifies:
+
+ Whether or not the web-based actions file editor may be used
+
+ Type of value:
+
+ 0 or 1
+
+ Default value:
+
+ 0
+
+ Effect if unset:
+
+ The web-based actions file editor is disabled.
+
+ Notes:
+
+ Access to the editor can not be controlled separately by "ACLs" or
+ HTTP authentication, so that everybody who can access Privoxy (see
+ "ACLs" and listen-address above) can modify its configuration for
+ all users.
+
+ This option is not recommended for environments with untrusted
+ users and as a lot of Privoxy users don't read documentation, this
+ feature is disabled by default.
+
+ Note that malicious client side code (e.g Java) is also capable of
+ using the actions editor and you shouldn't enable this options
+ unless you understand the consequences and are sure your browser
+ is configured correctly.
+
+ Note that you must have compiled Privoxy with support for this
+ feature, otherwise this option has no effect.
+
+ --------------------------------------------------------------------------
+
+ 7.4.6. enforce-blocks
+
+ Specifies:
+
+ Whether the user is allowed to ignore blocks and can "go there
+ anyway".
+
+ Type of value:
+
+ 0 or 1
+
+ Default value:
+
+ 0
+
+ Effect if unset:
+
+ Blocks are not enforced.
+
+ Notes:
+
+ Privoxy is mainly used to block and filter requests as a service
+ to the user, for example to block ads and other junk that clogs
+ the pipes. Privoxy's configuration isn't perfect and sometimes
+ innocent pages are blocked. In this situation it makes sense to
+ allow the user to enforce the request and have Privoxy ignore the
+ block.
+
+ In the default configuration Privoxy's "Blocked" page contains a
+ "go there anyway" link to adds a special string (the force prefix)
+ to the request URL. If that link is used, Privoxy will detect the
+ force prefix, remove it again and let the request pass.
+
+ Of course Privoxy can also be used to enforce a network policy. In
+ that case the user obviously should not be able to bypass any
+ blocks, and that's what the "enforce-blocks" option is for. If
+ it's enabled, Privoxy hides the "go there anyway" link. If the
+ user adds the force prefix by hand, it will not be accepted and
+ the circumvention attempt is logged.
+
+ Examples:
+
+ enforce-blocks 1
+
+ --------------------------------------------------------------------------
+
+ 7.4.7. ACLs: permit-access and deny-access
+
+ Specifies:
+
+ Who can access what.
+
+ Type of value:
+
+ src_addr[/src_masklen] [dst_addr[/dst_masklen]]
+
+ Where src_addr and dst_addr are IP addresses in dotted decimal
+ notation or valid DNS names, and src_masklen and dst_masklen are
+ subnet masks in CIDR notation, i.e. integer values from 2 to 30
+ representing the length (in bits) of the network address. The
+ masks and the whole destination part are optional.
+
+ Default value:
+
+ Unset
+
+ Effect if unset:
+
+ Don't restrict access further than implied by listen-address
+
+ Notes:
+
+ Access controls are included at the request of ISPs and systems
+ administrators, and are not usually needed by individual users.
+ For a typical home user, it will normally suffice to ensure that
+ Privoxy only listens on the localhost (127.0.0.1) or internal
+ (home) network address by means of the listen-address option.
+
+ Please see the warnings in the FAQ that Privoxy is not intended to
+ be a substitute for a firewall or to encourage anyone to defer
+ addressing basic security weaknesses.
+
+ Multiple ACL lines are OK. If any ACLs are specified, Privoxy only
+ talks to IP addresses that match at least one permit-access line
+ and don't match any subsequent deny-access line. In other words,
+ the last match wins, with the default being deny-access.
+
+ If Privoxy is using a forwarder (see forward below) for a
+ particular destination URL, the dst_addr that is examined is the
+ address of the forwarder and NOT the address of the ultimate
+ target. This is necessary because it may be impossible for the
+ local Privoxy to determine the IP address of the ultimate target
+ (that's often what gateways are used for).
+
+ You should prefer using IP addresses over DNS names, because the
+ address lookups take time. All DNS names must resolve! You can not
+ use domain patterns like "*.org" or partial domain names. If a DNS
+ name resolves to multiple IP addresses, only the first one is
+ used.
+
+ Denying access to particular sites by ACL may have undesired side
+ effects if the site in question is hosted on a machine which also
+ hosts other sites (most sites are).
+
+ Examples:
+
+ Explicitly define the default behavior if no ACL and
+ listen-address are set: "localhost" is OK. The absence of a
+ dst_addr implies that all destination addresses are OK:
+
+ permit-access localhost
+
+ Allow any host on the same class C subnet as www.privoxy.org
+ access to nothing but www.example.com (or other domains hosted on
+ the same system):
+
+ permit-access www.privoxy.org/24 www.example.com/32
+
+ Allow access from any host on the 26-bit subnet 192.168.45.64 to
+ anywhere, with the exception that 192.168.45.73 may not access the
+ IP address behind www.dirty-stuff.example.com:
+
+ permit-access 192.168.45.64/26
+ deny-access 192.168.45.73 www.dirty-stuff.example.com
+
+ --------------------------------------------------------------------------
+
+ 7.4.8. buffer-limit
+
+ Specifies:
+
+ Maximum size of the buffer for content filtering.
+
+ Type of value:
+
+ Size in Kbytes
+
+ Default value:
+
+ 4096
+
+ Effect if unset:
+
+ Use a 4MB (4096 KB) limit.
+
+ Notes:
+
+ For content filtering, i.e. the +filter and +deanimate-gif
+ actions, it is necessary that Privoxy buffers the entire document
+ body. This can be potentially dangerous, since a server could just
+ keep sending data indefinitely and wait for your RAM to exhaust --
+ with nasty consequences. Hence this option.
+
+ When a document buffer size reaches the buffer-limit, it is
+ flushed to the client unfiltered and no further attempt to filter
+ the rest of the document is made. Remember that there may be
+ multiple threads running, which might require up to buffer-limit
+ Kbytes each, unless you have enabled "single-threaded" above.
+
+ --------------------------------------------------------------------------
+
+ 7.5. Forwarding
+
+ This feature allows routing of HTTP requests through a chain of multiple
+ proxies.
+
+ Forwarding can be used to chain Privoxy with a caching proxy to speed up
+ browsing. Using a parent proxy may also be necessary if the machine that
+ Privoxy runs on has no direct Internet access.
+
+ Note that parent proxies can severely decrease your privacy level. For
+ example a parent proxy could add your IP address to the request headers
+ and if it's a caching proxy it may add the "Etag" header to revalidation
+ requests again, even though you configured Privoxy to remove it. It may
+ also ignore Privoxy's header time randomization and use the original
+ values which could be used by the server as cookie replacement to track
+ your steps between visits.
+
+ Also specified here are SOCKS proxies. Privoxy supports the SOCKS 4 and
+ SOCKS 4A protocols.
+
+ --------------------------------------------------------------------------
+
+ 7.5.1. forward
+
+ Specifies:
+
+ To which parent HTTP proxy specific requests should be routed.
+
+ Type of value:
+
+ target_pattern http_parent[:port]
+
+ where target_pattern is a URL pattern that specifies to which
+ requests (i.e. URLs) this forward rule shall apply. Use / to
+ denote "all URLs". http_parent[:port] is the DNS name or IP
+ address of the parent HTTP proxy through which the requests should
+ be forwarded, optionally followed by its listening port (default:
+ 8080). Use a single dot (.) to denote "no forwarding".
+
+ Default value:
+
+ Unset
+
+ Effect if unset:
+
+ Don't use parent HTTP proxies.
+
+ Notes:
+
+ If http_parent is ".", then requests are not forwarded to another
+ HTTP proxy but are made directly to the web servers.
+
+ Multiple lines are OK, they are checked in sequence, and the last
+ match wins.
+
+ Examples:
+
+ Everything goes to an example parent proxy, except SSL on port 443
+ (which it doesn't handle):
+
+ forward / parent-proxy.example.org:8080
+ forward :443 .
+
+ Everything goes to our example ISP's caching proxy, except for
+ requests to that ISP's sites:
+
+ forward / caching-proxy.isp.example.net:8000
+ forward .isp.example.net .
+
+ --------------------------------------------------------------------------
+
+ 7.5.2. forward-socks4 and forward-socks4a
+
+ Specifies:
+
+ Through which SOCKS proxy (and optionally to which parent HTTP
+ proxy) specific requests should be routed.
+
+ Type of value:
+
+ target_pattern socks_proxy[:port] http_parent[:port]
+
+ where target_pattern is a URL pattern that specifies to which
+ requests (i.e. URLs) this forward rule shall apply. Use / to
+ denote "all URLs". http_parent and socks_proxy are IP addresses in
+ dotted decimal notation or valid DNS names (http_parent may be "."
+ to denote "no HTTP forwarding"), and the optional port parameters
+ are TCP ports, i.e. integer values from 1 to 64535
+
+ Default value:
+
+ Unset
+
+ Effect if unset:
+
+ Don't use SOCKS proxies.
+
+ Notes:
+
+ Multiple lines are OK, they are checked in sequence, and the last
+ match wins.
+
+ The difference between forward-socks4 and forward-socks4a is that
+ in the SOCKS 4A protocol, the DNS resolution of the target
+ hostname happens on the SOCKS server, while in SOCKS 4 it happens
+ locally.
+
+ If http_parent is ".", then requests are not forwarded to another
+ HTTP proxy but are made (HTTP-wise) directly to the web servers,
+ albeit through a SOCKS proxy.
+
+ Examples:
+
+ From the company example.com, direct connections are made to all
+ "internal" domains, but everything outbound goes through their
+ ISP's proxy by way of example.com's corporate SOCKS 4A gateway to
+ the Internet.
+
+ forward-socks4a / socks-gw.example.com:1080 www-cache.isp.example.net:8080
+ forward .example.com .
+
+ A rule that uses a SOCKS 4 gateway for all destinations but no
+ HTTP parent looks like this:
+
+ forward-socks4 / socks-gw.example.com:1080 .
+
+ To chain Privoxy and Tor, both running on the same system, you
+ would use something like:
+
+ forward-socks4a / 127.0.0.1:9050 .
+
+ The public Tor network can't be used to reach your local network,
+ if you need to access local servers you therefore might want to
+ make some exceptions:
+
+ forward 192.168.*.*/ .
+ forward 10.*.*.*/ .
+ forward 127.*.*.*/ .
+
+ Unencrypted connections to systems in these address ranges will be
+ as (un)secure as the local network is, but the alternative is that
+ you can't reach the local network through Privoxy at all. Of
+ course this may actually be desired and there is no reason to make
+ these exceptions if you aren't sure you need them.
+
+ If you also want to be able to reach servers in your local network
+ by using their names, you will need additional exceptions that
+ look like this:
+
+ forward localhost/ .
+
+ --------------------------------------------------------------------------
+
+ 7.5.3. Advanced Forwarding Examples
+
+ If you have links to multiple ISPs that provide various special content
+ only to their subscribers, you can configure multiple Privoxies which have
+ connections to the respective ISPs to act as forwarders to each other, so
+ that your users can see the internal content of all ISPs.
+
+ Assume that host-a has a PPP connection to isp-a.example.net. And host-b
+ has a PPP connection to isp-b.example.org. Both run Privoxy. Their
+ forwarding configuration can look like this:
+
+ host-a:
+
+ forward / .
+ forward .isp-b.example.net host-b:8118
+
+ host-b:
+
+ forward / .
+ forward .isp-a.example.org host-a:8118
+
+ Now, your users can set their browser's proxy to use either host-a or
+ host-b and be able to browse the internal content of both isp-a and isp-b.
+
+ If you intend to chain Privoxy and squid locally, then chaining as browser
+ -> squid -> privoxy is the recommended way.
+
+ Assuming that Privoxy and squid run on the same box, your squid
+ configuration could then look like this:
+
+ # Define Privoxy as parent proxy (without ICP)
+ cache_peer 127.0.0.1 parent 8118 7 no-query
+
+ # Define ACL for protocol FTP
+ acl ftp proto FTP
+
+ # Do not forward FTP requests to Privoxy
+ always_direct allow ftp
+
+ # Forward all the rest to Privoxy
+ never_direct allow all
+
+ You would then need to change your browser's proxy settings to squid's
+ address and port. Squid normally uses port 3128. If unsure consult
+ http_port in squid.conf.
+
+ You could just as well decide to only forward requests you suspect of
+ leading to Windows executables through a virus-scanning parent proxy, say,
+ on antivir.example.com, port 8010:
+
+ forward / .
+ forward /.*\.(exe|com|dll|zip)$ antivir.example.com:8010
+
+ --------------------------------------------------------------------------
+
+ 7.5.4. forwarded-connect-retries
+
+ Specifies:
+
+ How often Privoxy retries if a forwarded connection request fails.
+
+ Type of value:
+
+ Number of retries.
+
+ Default value:
+
+ 0
+
+ Effect if unset:
+
+ Connections forwarded through other proxies are treated like
+ direct connections and no retry attempts are made.
+
+ Notes:
+
+ forwarded-connect-retries is mainly interesting for socks4a
+ connections, where Privoxy can't detect why the connections
+ failed. The connection might have failed because of a DNS timeout
+ in which case a retry makes sense, but it might also have failed
+ because the server doesn't exist or isn't reachable. In this case
+ the retry will just delay the appearance of Privoxy's error
+ message.
+
+ Note that in the context of this option, "forwarded connections"
+ includes all connections that Privoxy forwards through other
+ proxies. This option is not limited to the HTTP CONNECT method.
+
+ Only use this option, if you are getting lots of
+ forwarding-related error messages that go away when you try again
+ manually. Start with a small value and check Privoxy's logfile
+ from time to time, to see how many retries are usually needed.
+
+ Examples:
+
+ forwarded-connect-retries 1
+
+ --------------------------------------------------------------------------
+
+ 7.5.5. accept-intercepted-requests
+
+ Specifies:
+
+ Whether intercepted requests should be treated as valid.
+
+ Type of value:
+
+ 0 or 1
+
+ Default value:
+
+ 0
+
+ Effect if unset:
+
+ Only proxy requests are accepted, intercepted requests are treated
+ as invalid.
+
+ Notes:
+
+ If you don't trust your clients and want to force them to use
+ Privoxy, enable this option and configure your packet filter to
+ redirect outgoing HTTP connections into Privoxy.
+
+ Make sure that Privoxy's own requests aren't redirected as well.
+ Additionally take care that Privoxy can't intentionally connect to
+ itself, otherwise you could run into redirection loops if
+ Privoxy's listening port is reachable by the outside or an
+ attacker has access to the pages you visit.
+
+ Examples:
+
+ accept-intercepted-requests 1
+
+ --------------------------------------------------------------------------
+
+ 7.5.6. allow-cgi-request-crunching
+
+ Specifies:
+
+ Whether requests to Privoxy's CGI pages can be blocked or
+ redirected.
+
+ Type of value:
+
+ 0 or 1
+
+ Default value:
+
+ 0
+
+ Effect if unset:
+
+ Privoxy ignores block and redirect actions for its CGI pages.
+
+ Notes:
+
+ By default Privoxy ignores block or redirect actions for its CGI
+ pages. Intercepting these requests can be useful in multi-user
+ setups to implement fine-grained access control, but it can also
+ render the complete web interface useless and make debugging
+ problems painful if done without care.
+
+ Don't enable this option unless you're sure that you really need
+ it.
+
+ Examples:
+
+ allow-cgi-request-crunching 1
+
+ --------------------------------------------------------------------------
+
+ 7.5.7. split-large-forms
+
+ Specifies:
+
+ Whether the CGI interface should stay compatible with broken HTTP
+ clients.
+
+ Type of value:
+
+ 0 or 1
+
+ Default value:
+
+ 0
+
+ Effect if unset:
+
+ The CGI form generate long GET URLs.
+
+ Notes:
+
+ Privoxy's CGI forms can lead to rather long URLs. This isn't a
+ problem as far as the HTTP standard is concerned, but it can
+ confuse clients with arbitrary URL length limitations.
+
+ Enabling split-large-forms causes Privoxy to divide big forms into
+ smaller ones to keep the URL length down. It makes editing a lot
+ less convenient and you can no longer submit all changes at once,
+ but at least it works around this browser bug.
+
+ If you don't notice any editing problems, there is no reason to
+ enable this option, but if one of the submit buttons appears to be
+ broken, you should give it a try.
+
+ Examples:
+
+ split-large-forms 1
+
+ --------------------------------------------------------------------------
+
+ 7.6. Windows GUI Options
+
+ Privoxy has a number of options specific to the Windows GUI interface:
+
+ If "activity-animation" is set to 1, the Privoxy icon will animate when
+ "Privoxy" is active. To turn off, set to 0.
+
+ activity-animation 1
+
+
+ If "log-messages" is set to 1, Privoxy will log messages to the console
+ window:
+
+ log-messages 1
+
+
+ If "log-buffer-size" 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 "log-max-lines" (see below).
+
+ Warning: Setting this to 0 will result in the buffer to grow infinitely
+ and eat up all your memory!
+
+ log-buffer-size 1
+
+
+ log-max-lines is the maximum number of lines held in the log buffer. See
+ above.
+
+ log-max-lines 200
+
+
+ If "log-highlight-messages" is set to 1, Privoxy will highlight portions
+ of the log messages with a bold-faced font:
+
+ log-highlight-messages 1
+
+
+ The font used in the console window:
+
+ log-font-name Comic Sans MS
+
+
+ Font size used in the console window:
+
+ log-font-size 8
+
+
+ "show-on-task-bar" controls whether or not Privoxy will appear as a button
+ on the Task bar when minimized:
+
+ show-on-task-bar 0
+
+
+ If "close-button-minimizes" is set to 1, the Windows close button will
+ minimize Privoxy instead of closing the program (close with the exit
+ option on the File menu).
+
+ close-button-minimizes 1
+
+
+ The "hide-console" option is specific to the MS-Win console version of
+ Privoxy. If this option is used, Privoxy will disconnect from and hide the
+ command console.
+
+ #hide-console
+
+
+ --------------------------------------------------------------------------
+
+8. Actions Files
+
+ The actions files are used to define what actions Privoxy takes for which
+ URLs, and thus determines how ad images, cookies and various other aspects
+ of HTTP content and transactions are handled, and on which sites (or even
+ parts thereof). There are a number of such actions, with a wide range of
+ functionality. Each action does something a little different. These
+ actions give us a veritable arsenal of tools with which to exert our
+ control, preferences and independence. Actions can be combined so that
+ their effects are aggregated when applied against a given set of URLs.
+
+ There are three action files included with Privoxy with differing
+ purposes:
+
+ * default.action - is the primary action file that sets the initial
+ values for all actions. It is intended to provide a base level of
+ functionality for Privoxy's array of features. So it is a set of broad
+ rules that should work reasonably well as-is for most users. This is
+ the file that the developers are keeping updated, and making available
+ to users. The user's preferences as set in standard.action, e.g.
+ either Cautious (the default), Medium, or Advanced (see below).
+
+ * user.action - is intended to be for local site preferences and
+ exceptions. As an example, if your ISP or your bank has specific
+ requirements, and need special handling, this kind of thing should go
+ here. This file will not be upgraded.
+
+ * standard.action - is used only by the web based editor at
+ http://config.privoxy.org/edit-actions-list?f=default, to set various
+ pre-defined sets of rules for the default actions section in
+ default.action.
+
+ Edit Set to Cautious Set to Medium Set to Advanced
+
+ These have increasing levels of aggressiveness and have no influence
+ on your browsing unless you select them explicitly in the editor. A
+ default installation should be pre-set to Cautious (versions prior to
+ 3.0.5 were set to Medium). New users should try this for a while
+ before adjusting the settings to more aggressive levels. The more
+ aggressive the settings, then the more likelihood there is of problems
+ such as sites not working as they should.
+
+ The Edit button allows you to turn each action on/off individually for
+ fine-tuning. The Cautious button changes the actions list to low/safe
+ settings which will activate ad blocking and a minimal set of
+ Privoxy's features, and subsequently there will be less of a chance
+ for accidental problems. The Medium button sets the list to a medium
+ level of other features and a low level set of privacy features. The
+ Advanced button sets the list to a high level of ad blocking and
+ medium level of privacy. See the chart below. The latter three buttons
+ over-ride any changes via with the Edit button. More fine-tuning can
+ be done in the lower sections of this internal page.
+
+ It is not recommend to edit the standard.action file itself.
+
+ The default profiles, and their associated actions, as pre-defined in
+ standard.action are:
+
+ Table 1. Default Configurations
+
+ +--------------------------------------------------------------------+
+ | Feature | Cautious | Medium | Advanced |
+ |-------------------------+-------------+--------------+-------------|
+ | Ad-blocking | medium | high | high |
+ | Aggressiveness | | | |
+ |-------------------------+-------------+--------------+-------------|
+ | Ad-filtering by size | no | yes | yes |
+ |-------------------------+-------------+--------------+-------------|
+ | Ad-filtering by link | no | no | yes |
+ |-------------------------+-------------+--------------+-------------|
+ | Pop-up killing | blocks only | blocks only | blocks only |
+ |-------------------------+-------------+--------------+-------------|
+ | Privacy Features | low | medium | medium/high |
+ |-------------------------+-------------+--------------+-------------|
+ | Cookie handling | none | session-only | kill |
+ |-------------------------+-------------+--------------+-------------|
+ | Referer forging | no | yes | yes |
+ |-------------------------+-------------+--------------+-------------|
+ | GIF de-animation | no | yes | yes |
+ |-------------------------+-------------+--------------+-------------|
+ | Fast redirects | no | no | yes |
+ |-------------------------+-------------+--------------+-------------|
+ | HTML taming | no | no | yes |
+ |-------------------------+-------------+--------------+-------------|
+ | JavaScript taming | no | no | yes |
+ |-------------------------+-------------+--------------+-------------|
+ | Web-bug killing | no | yes | yes |
+ |-------------------------+-------------+--------------+-------------|
+ | Image tag reordering | no | no | yes |
+ +--------------------------------------------------------------------+
+
+ The list of actions files to be used are defined in the main configuration
+ file, and are processed in the order they are defined (e.g. default.action
+ is typically processed before user.action). The content of these can all
+ be viewed and edited from http://config.privoxy.org/show-status. The
+ over-riding principle when applying actions, is that the last action that
+ matches a given URL wins. The broadest, most general rules go first
+ (defined in default.action), followed by any exceptions (typically also in
+ default.action), which are then followed lastly by any local preferences
+ (typically in user.action). Generally, user.action has the last word.
+
+ An actions file typically has multiple sections. If you want to use
+ "aliases" in an actions file, you have to place the (optional) alias
+ section at the top of that file. Then comes the default set of rules which
+ will apply universally to all sites and pages (be very careful with using
+ such a universal set in user.action or any other actions file after
+ default.action, because it will override the result from consulting any
+ previous file). And then below that, exceptions to the defined universal
+ policies. You can regard user.action as an appendix to default.action,
+ with the advantage that it is a separate file, which makes preserving your
+ personal settings across Privoxy upgrades easier.
+
+ Actions can be used to block anything you want, including ads, banners, or
+ just some obnoxious URL whose content you would rather not see. Cookies
+ can be accepted or rejected, or accepted only during the current browser
+ session (i.e. not written to disk), content can be modified, some
+ JavaScripts tamed, user-tracking fooled, and much more. See below for a
+ complete list of actions.
+
+ --------------------------------------------------------------------------
+
+ 8.1. Finding the Right Mix
+
+ Note that some actions, like cookie suppression or script disabling, may
+ render some sites unusable that rely on these techniques to work properly.
+ Finding the right mix of actions is not always easy and certainly a matter
+ of personal taste. And, things can always change, requiring refinements in
+ the configuration. In general, it can be said that the more "aggressive"
+ your default settings (in the top section of the actions file) are, the
+ more exceptions for "trusted" sites you will have to make later. If, for
+ example, you want to crunch all cookies per default, you'll have to make
+ exceptions from that rule for sites that you regularly use and that
+ require cookies for actually useful purposes, like maybe your bank,
+ favorite shop, or newspaper.
+
+ We have tried to provide you with reasonable rules to start from in the
+ distribution actions files. But there is no general rule of thumb on these
+ things. There just are too many variables, and sites are constantly
+ changing. Sooner or later you will want to change the rules (and read this
+ chapter again :).
+
+ --------------------------------------------------------------------------
+
+ 8.2. How to Edit
+
+ The easiest way to edit the actions files is with a browser by using our
+ browser-based editor, which can be reached from
+ http://config.privoxy.org/show-status. Note: the config file option
+ enable-edit-actions must be enabled for this to work. The editor allows
+ both fine-grained control over every single feature on a per-URL basis,
+ and easy choosing from wholesale sets of defaults like "Cautious",
+ "Medium" or "Advanced". Warning: the "Advanced" setting is more
+ aggressive, and will be more likely to cause problems for some sites.
+ Experienced users only!
+
+ If you prefer plain text editing to GUIs, you can of course also directly
+ edit the the actions files with your favorite text editor. Look at
+ default.action which is richly commented with many good examples.
+
+ --------------------------------------------------------------------------
+
+ 8.3. How Actions are Applied to Requests
+
+ Actions files are divided into sections. There are special sections, like
+ the "alias" sections which will be discussed later. For now let's
+ concentrate on regular sections: They have a heading line (often split up
+ to multiple lines for readability) which consist of a list of actions,
+ separated by whitespace and enclosed in curly braces. Below that, there is
+ a list of URL and tag patterns, each on a separate line.
+
+ To determine which actions apply to a request, the URL of the request is
+ compared to all URL patterns in each "action file". Every time it matches,
+ the list of applicable actions for the request is incrementally updated,
+ using the heading of the section in which the pattern is located. The same
+ is done again for tags and tag patterns later on.
+
+ If multiple applying sections set the same action differently, the last
+ match wins. If not, the effects are aggregated. E.g. a URL might match a
+ regular section with a heading line of { +handle-as-image }, then later
+ another one with just { +block }, resulting in both actions to apply. And
+ there may well be cases where you will want to combine actions together.
+ Such a section then might look like:
+
+ { +handle-as-image +block }
+ # Block these as if they were images. Send no block page.
+ banners.example.com
+ media.example.com/.*banners
+ .example.com/images/ads/
+
+ You can trace this process for URL patterns and any given URL by visiting
+ http://config.privoxy.org/show-url-info.
+
+ Examples and more detail on this is provided in the Appendix,
+ Troubleshooting: Anatomy of an Action section.
+
+ --------------------------------------------------------------------------
+
+ 8.4. Patterns
+
+ As mentioned, Privoxy uses "patterns" to determine what actions might
+ apply to which sites and pages your browser attempts to access. These
+ "patterns" use wild card type pattern matching to achieve a high degree of
+ flexibility. This allows one expression to be expanded and potentially
+ match against many similar patterns.
+
+ Generally, an URL pattern has the form <domain>/<path>, where both the
+ <domain> and <path> are optional. (This is why the special / pattern
+ matches all URLs). Note that the protocol portion of the URL pattern (e.g.
+ http://) should not be included in the pattern. This is assumed already!
+
+ The pattern matching syntax is different for the domain and path parts of
+ the URL. The domain part uses a simple globbing type matching technique,
+ while the path part uses a more flexible "Regular Expressions (PCRE)"
+ based syntax.
+
+ www.example.com/
+
+ is a domain-only pattern and will match any request to
+ www.example.com, regardless of which document on that server is
+ requested. So ALL pages in this domain would be covered by the
+ scope of this action. Note that a simple example.com is different
+ and would NOT match.
+
+ www.example.com
+
+ means exactly the same. For domain-only patterns, the trailing /
+ may be omitted.
+
+ www.example.com/index.html$
+
+ matches all the documents on www.example.com whose name starts
+ with /index.html.
+
+ www.example.com/index.html$
+
+ matches only the single document /index.html on www.example.com.
+
+ /index.html$
+
+ matches the document /index.html, regardless of the domain, i.e.
+ on any web server anywhere.
+
+ index.html
+
+ matches nothing, since it would be interpreted as a domain name
+ and there is no top-level domain called .html. So its a mistake.
+
+ --------------------------------------------------------------------------
+
+ 8.4.1. The Domain Pattern
+
+ 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:
+
+ .example.com
+
+ matches any domain with first-level domain com and second-level
+ domain example. For example www.example.com, example.com and
+ foo.bar.baz.example.com. Note that it wouldn't match if the
+ second-level domain was another-example.
+
+ www.
+
+ matches any domain that STARTS with www. (It also matches the
+ domain www but most of the time that doesn't matter.)
+
+ .example.
+
+ matches any domain that CONTAINS .example.. And, by the way, also
+ included would be any files or documents that exist within that
+ domain since no path limitations are specified. (Correctly
+ speaking: It matches any FQDN that contains example as a domain.)
+ This might be www.example.com, news.example.de, or
+ www.example.net/cgi/testing.pl for instance. All these cases are
+ matched.
+
+ Additionally, there are wild-cards that you can use in the domain names
+ themselves. These work similarly to shell globbing type wild-cards: "*"
+ represents zero or more arbitrary characters (this is equivalent to the
+ "Regular Expression" based syntax of ".*"), "?" represents any single
+ character (this is equivalent to the regular expression syntax of a simple
+ "."), and you can define "character classes" in square brackets which is
+ similar to the same regular expression technique. All of this can be
+ freely mixed:
+
+ ad*.example.com
+
+ matches "adserver.example.com", "ads.example.com", etc but not
+ "sfads.example.com"
+
+ *ad*.example.com
+
+ matches all of the above, and then some.
+
+ .?pix.com
+
+ matches www.ipix.com, pictures.epix.com, a.b.c.d.e.upix.com etc.
+
+ www[1-9a-ez].example.c*
+
+ matches www1.example.com, www4.example.cc, wwwd.example.cy,
+ wwwz.example.com etc., but not wwww.example.com.
+
+ While flexible, this is not the sophistication of full regular expression
+ based syntax.
+
+ --------------------------------------------------------------------------
+
+ 8.4.2. The Path Pattern
+
+ Privoxy uses Perl compatible (PCRE) "Regular Expression" based syntax
+ (through the PCRE library) for matching the path portion (after the
+ slash), and is thus more flexible.
+
+ There is an Appendix with a brief quick-start into regular expressions,
+ and full (very technical) documentation on PCRE regex syntax is available
+ on-line at http://www.pcre.org/man.txt. You might also find the Perl man
+ page on regular expressions (man perlre) useful, which is available
+ on-line at http://perldoc.perl.org/perlre.html.
+
+ Note that the path pattern is automatically left-anchored at the "/", i.e.
+ it matches as if it would start with a "^" (regular expression speak for
+ the beginning of a line).
+
+ Please also note that matching in the path is CASE INSENSITIVE by default,
+ but you can switch to case sensitive at any point in the pattern by using
+ the "(?-i)" switch: www.example.com/(?-i)PaTtErN.* will match only
+ documents whose path starts with PaTtErN in exactly this capitalization.
+
+ .example.com/.*
+
+ Is equivalent to just ".example.com", since any documents within
+ that domain are matched with or without the ".*" regular
+ expression. This is redundant
+
+ .example.com/.*/index.html$
+
+ Will match any page in the domain of "example.com" that is named
+ "index.html", and that is part of some path. For example, it
+ matches "www.example.com/testing/index.html" but NOT
+ "www.example.com/index.html" because the regular expression called
+ for at least two "/'s", thus the path requirement. It also would
+ match "www.example.com/testing/index_html", because of the special
+ meta-character ".".
+
+ .example.com/(.*/)?index\.html$
+
+ This regular expression is conditional so it will match any page
+ named "index.html" regardless of path which in this case can have
+ one or more "/'s". And this one must contain exactly ".html" (but
+ does not have to end with that!).
+
+ .example.com/(.*/)(ads|banners?|junk)
+
+ This regular expression will match any path of "example.com" that
+ contains any of the words "ads", "banner", "banners" (because of
+ the "?") or "junk". The path does not have to end in these words,
+ just contain them.
+
+ .example.com/(.*/)(ads|banners?|junk)/.*\.(jpe?g|gif|png)$
+
+ This is very much the same as above, except now it must end in
+ either ".jpg", ".jpeg", ".gif" or ".png". So this one is limited
+ to common image formats.
+
+ There are many, many good examples to be found in default.action, and more
+ tutorials below in Appendix on regular expressions.
+
+ --------------------------------------------------------------------------
+
+ 8.4.3. The Tag Pattern
+
+ Tag patterns are used to change the applying actions based on the
+ request's tags. Tags can be created with either the client-header-tagger
+ or the server-header-tagger action.
+
+ Tag patterns have to start with "TAG:", so Privoxy can tell them apart
+ from URL patterns. Everything after the colon including white space, is
+ interpreted as a regular expression with path pattern syntax, except that
+ tag patterns aren't left-anchored automatically (Privoxy doesn't silently
+ add a "^", you have to do it yourself if you need it).
+
+ To match all requests that are tagged with "foo" your pattern line should
+ be "TAG:^foo$", "TAG:foo" would work as well, but it would also match
+ requests whose tags contain "foo" somewhere. "TAG: foo" wouldn't work as
+ it requires white space.
+
+ Sections can contain URL and tag patterns at the same time, but tag
+ patterns are checked after the URL patterns and thus always overrule them,
+ even if they are located before the URL patterns.
+
+ Once a new tag is added, Privoxy checks right away if it's matched by one
+ of the tag patterns and updates the action settings accordingly. As a
+ result tags can be used to activate other tagger actions, as long as these
+ other taggers look for headers that haven't already be parsed.
+
+ For example you could tag client requests which use the POST method, then
+ use this tag to activate another tagger that adds a tag if cookies are
+ sent, and then use a block action based on the cookie tag. This allows the
+ outcome of one action, to be input into a subsequent action. However if
+ you'd reverse the position of the described taggers, and activated the
+ method tagger based on the cookie tagger, no method tags would be created.
+ The method tagger would look for the request line, but at the time the
+ cookie tag is created, the request line has already been parsed.
+
+ While this is a limitation you should be aware of, this kind of
+ indirection is seldom needed anyway and even the example doesn't make too
+ much sense.
+
+ --------------------------------------------------------------------------
+
+ 8.5. Actions
+
+ All actions are disabled by default, until they are explicitly enabled
+ somewhere in an actions file. Actions are turned on if preceded with a
+ "+", and turned off if preceded with a "-". So a +action means "do that
+ action", e.g. +block means "please block URLs that match the following
+ patterns", and -block means "don't block URLs that match the following
+ patterns, even if +block previously applied."
+
+ Again, actions are invoked by placing them on a line, enclosed in curly
+ braces and separated by whitespace, like in {+some-action
+ -some-other-action{some-parameter}}, followed by a list of URL patterns,
+ one per line, to which they apply. Together, the actions line and the
+ following pattern lines make up a section of the actions file.
+
+ Actions fall into three categories:
+
+ * Boolean, i.e the action can only be "enabled" or "disabled". Syntax:
+
+ +name # enable action name
+ -name # disable action name
+
+ Example: +block
+
+ * Parameterized, where some value is required in order to enable this
+ type of action. Syntax:
+
+ +name{param} # enable action and set parameter to param,
+ # overwriting parameter from previous match if necessary
+ -name # disable action. The parameter can be omitted
+
+ Note that if the URL matches multiple positive forms of a
+ parameterized action, the last match wins, i.e. the params from
+ earlier matches are simply ignored.
+
+ Example: +hide-user-agent{Mozilla/5.0 (X11; U; FreeBSD i386; en-US;
+ rv:1.8.1.4) Gecko/20070602 Firefox/2.0.0.4}
+
+ * Multi-value. These look exactly like parameterized actions, but they
+ behave differently: If the action applies multiple times to the same
+ URL, but with different parameters, all the parameters from all
+ matches are remembered. This is used for actions that can be executed
+ for the same request repeatedly, like adding multiple headers, or
+ filtering through multiple filters. Syntax:
+
+ +name{param} # enable action and add param to the list of parameters
+ -name{param} # remove the parameter param from the list of parameters
+ # If it was the last one left, disable the action.
+ -name # disable this action completely and remove all parameters from the list
+
+ Examples: +add-header{X-Fun-Header: Some text} and
+ +filter{html-annoyances}
+
+ If nothing is specified in any actions file, no "actions" are taken. So in
+ this case Privoxy would just be a normal, non-blocking, non-filtering
+ proxy. You must specifically enable the privacy and blocking features you
+ need (although the provided default actions files will give a good
+ starting point).
+
+ Later defined action sections always over-ride earlier ones of the same
+ type. So exceptions to any rules you make, should come in the latter part
+ of the file (or in a file that is processed later when using multiple
+ actions files such as user.action). For multi-valued actions, the actions
+ are applied in the order they are specified. Actions files are processed
+ in the order they are defined in config (the default installation has
+ three actions files). It also quite possible for any given URL to match
+ more than one "pattern" (because of wildcards and regular expressions),
+ and thus to trigger more than one set of actions! Last match wins.
+
+ The list of valid Privoxy actions are:
+
+ --------------------------------------------------------------------------
+
+ 8.5.1. add-header
+
+ Typical use:
+
+ Confuse log analysis, custom applications
+
+ Effect:
+
+ Sends a user defined HTTP header to the web server.
+
+ Type:
+
+ Multi-value.
+
+ Parameter:
+
+ Any string value is possible. Validity of the defined HTTP headers
+ is not checked. It is recommended that you use the "X-" prefix for
+ custom headers.
+
+ Notes:
+
+ This action may be specified multiple times, in order to define
+ multiple headers. This is rarely needed for the typical user. If
+ you don't know what "HTTP headers" are, you definitely don't need
+ to worry about this one.
+
+ Example usage:
+
+ +add-header{X-User-Tracking: sucks}
+
+ --------------------------------------------------------------------------
+
+ 8.5.2. block
+
+ Typical use:
+
+ Block ads or other unwanted content
+
+ Effect:
+
+ Requests for URLs to which this action applies are blocked, i.e.
+ the requests are trapped by Privoxy and the requested URL is never
+ retrieved, but is answered locally with a substitute page or
+ image, as determined by the handle-as-image, set-image-blocker,
+ and handle-as-empty-document actions.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ Privoxy sends a special "BLOCKED" page for requests to blocked
+ pages. This page contains links to find out why the request was
+ blocked, and a click-through to the blocked content (the latter
+ only if compiled with the force feature enabled). The "BLOCKED"
+ page adapts to the available screen space -- it displays
+ full-blown if space allows, or miniaturized and text-only if
+ loaded into a small frame or window. If you are using Privoxy
+ right now, you can take a look at the "BLOCKED" page.
+
+ A very important exception occurs if both block and
+ handle-as-image, apply to the same request: it will then be
+ replaced by an image. If set-image-blocker (see below) also
+ applies, the type of image will be determined by its parameter, if
+ not, the standard checkerboard pattern is sent.
+
+ It is important to understand this process, in order to understand
+ how Privoxy deals with ads and other unwanted content. Blocking is
+ a core feature, and one upon which various other features depend.
+
+ The filter action can perform a very similar task, by "blocking"
+ banner images and other content through rewriting the relevant
+ URLs in the document's HTML source, so they don't get requested in
+ the first place. Note that this is a totally different technique,
+ and it's easy to confuse the two.
+
+ Example usage (section):
+
+ {+block}
+ # Block and replace with "blocked" page
+ .nasty-stuff.example.com
+
+ {+block +handle-as-image}
+ # Block and replace with image
+ .ad.doubleclick.net
+ .ads.r.us/banners/
+
+ {+block +handle-as-empty-document}
+ # Block and then ignore
+ adserver.exampleclick.net/.*\.js$
+
+ --------------------------------------------------------------------------
+
+ 8.5.3. client-header-filter
+
+ Typical use:
+
+ Rewrite or remove single client headers.
+
+ Effect:
+
+ All client headers to which this action applies are filtered
+ on-the-fly through the specified regular expression based
+ substitutions.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ The name of a client-header filter, as defined in one of the
+ filter files.
+
+ Notes:
+
+ Client-header filters are applied to each header on its own, not
+ to all at once. This makes it easier to diagnose problems, but on
+ the downside you can't write filters that only change header x if
+ header y's value is z. You can do that by using tags though.
+
+ Client-header filters are executed after the other header actions
+ have finished and use their output as input.
+
+ If the request URL gets changed, Privoxy will detect that and use
+ the new one. This can be used to rewrite the request destination
+ behind the client's back, for example to specify a Tor exit relay
+ for certain requests.
+
+ Please refer to the filter file chapter to learn which
+ client-header filters are available by default, and how to create
+ your own.
+
+ Example usage (section):
+
+ {+client-header-filter{hide-tor-exit-notation}}
+ .exit/
+
+
+ --------------------------------------------------------------------------
+
+ 8.5.4. client-header-tagger
+
+ Typical use:
+
+ Block requests based on their headers.
+
+ Effect:
+
+ Client headers to which this action applies are filtered
+ on-the-fly through the specified regular expression based
+ substitutions, the result is used as tag.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ The name of a client-header tagger, as defined in one of the
+ filter files.
+
+ Notes:
+
+ Client-header taggers are applied to each header on its own, and
+ as the header isn't modified, each tagger "sees" the original.
+
+ Client-header taggers are the first actions that are executed and
+ their tags can be used to control every other action.
+
+ Example usage (section):
+
+ # Tag every request with the User-Agent header
+ {+client-header-tagger{user-agent}}
+ /
+
+
+ --------------------------------------------------------------------------
+
+ 8.5.5. content-type-overwrite
+
+ Typical use:
+
+ Stop useless download menus from popping up, or change the
+ browser's rendering mode
+
+ Effect:
+
+ Replaces the "Content-Type:" HTTP server header.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ Any string.
+
+ Notes:
+
+ The "Content-Type:" HTTP server header is used by the browser to
+ decide what to do with the document. The value of this header can
+ cause the browser to open a download menu instead of displaying
+ the document by itself, even if the document's format is supported
+ by the browser.
+
+ The declared content type can also affect which rendering mode the
+ browser chooses. If XHTML is delivered as "text/html", many
+ browsers treat it as yet another broken HTML document. If it is
+ send as "application/xml", browsers with XHTML support will only
+ display it, if the syntax is correct.
+
+ If you see a web site that proudly uses XHTML buttons, but sets
+ "Content-Type: text/html", you can use Privoxy to overwrite it
+ with "application/xml" and validate the web master's claim inside
+ your XHTML-supporting browser. If the syntax is incorrect, the
+ browser will complain loudly.
+
+ You can also go the opposite direction: if your browser prints
+ error messages instead of rendering a document falsely declared as
+ XHTML, you can overwrite the content type with "text/html" and
+ have it rendered as broken HTML document.
+
+ By default content-type-overwrite only replaces "Content-Type:"
+ headers that look like some kind of text. If you want to overwrite
+ it unconditionally, you have to combine it with force-text-mode.
+ This limitation exists for a reason, think twice before
+ circumventing it.
+
+ Most of the time it's easier to replace this action with a custom
+ server-header filter. It allows you to activate it for every
+ document of a certain site and it will still only replace the
+ content types you aimed at.
+
+ Of course you can apply content-type-overwrite to a whole site and
+ then make URL based exceptions, but it's a lot more work to get
+ the same precision.
+
+ Example usage (sections):
+
+ # Check if www.example.net/ really uses valid XHTML
+ { +content-type-overwrite{application/xml} }
+ www.example.net/
+
+ # but leave the content type unmodified if the URL looks like a style sheet
+ {-content-type-overwrite}
+ www.example.net/.*\.css$
+ www.example.net/.*style
+
+ --------------------------------------------------------------------------
+
+ 8.5.6. crunch-client-header
+
+ Typical use:
+
+ Remove a client header Privoxy has no dedicated action for.
+
+ Effect:
+
+ Deletes every header sent by the client that contains the string
+ the user supplied as parameter.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ Any string.
+
+ Notes:
+
+ This action allows you to block client headers for which no
+ dedicated Privoxy action exists. Privoxy will remove every client
+ header that contains the string you supplied as parameter.
+
+ Regular expressions are not supported and you can't use this
+ action to block different headers in the same request, unless they
+ contain the same string.
+
+ crunch-client-header is only meant for quick tests. If you have to
+ block several different headers, or only want to modify parts of
+ them, you should use a client-header filter.
+
+ +---------------------------------------------------------+
+ | Warning |
+ |---------------------------------------------------------|
+ | Don't block any header without understanding the |
+ | consequences. |
+ +---------------------------------------------------------+
+
+ Example usage (section):
+
+ # Block the non-existent "Privacy-Violation:" client header
+ { +crunch-client-header{Privacy-Violation:} }
+ /
+
+
+ --------------------------------------------------------------------------
+
+ 8.5.7. crunch-if-none-match
+
+ Typical use:
+
+ Prevent yet another way to track the user's steps between
+ sessions.
+
+ Effect:
+
+ Deletes the "If-None-Match:" HTTP client header.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ Removing the "If-None-Match:" HTTP client header is useful for
+ filter testing, where you want to force a real reload instead of
+ getting status code "304" which would cause the browser to use a
+ cached copy of the page.
+
+ It is also useful to make sure the header isn't used as a cookie
+ replacement (unlikely but possible).
+
+ Blocking the "If-None-Match:" header shouldn't cause any caching
+ problems, as long as the "If-Modified-Since:" header isn't blocked
+ or missing as well.
+
+ It is recommended to use this action together with
+ hide-if-modified-since and overwrite-last-modified.
+
+ Example usage (section):
+
+ # Let the browser revalidate cached documents but don't
+ # allow the server to use the revalidation headers for user tracking.
+ {+hide-if-modified-since{-60} \
+ +overwrite-last-modified{randomize} \
+ +crunch-if-none-match}
+ /
+
+ --------------------------------------------------------------------------
+
+ 8.5.8. crunch-incoming-cookies
+
+ Typical use:
+
+ Prevent the web server from setting HTTP cookies on your system
+
+ Effect:
+
+ Deletes any "Set-Cookie:" HTTP headers from server replies.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ This action is only concerned with incoming HTTP cookies. For
+ outgoing HTTP cookies, use crunch-outgoing-cookies. Use both to
+ disable HTTP cookies completely.
+
+ It makes no sense at all to use this action in conjunction with
+ the session-cookies-only action, since it would prevent the
+ session cookies from being set. See also filter-content-cookies.
+
+ Example usage:
+
+ +crunch-incoming-cookies
+
+ --------------------------------------------------------------------------
+
+ 8.5.9. crunch-server-header
+
+ Typical use:
+
+ Remove a server header Privoxy has no dedicated action for.
+
+ Effect:
+
+ Deletes every header sent by the server that contains the string
+ the user supplied as parameter.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ Any string.
+
+ Notes:
+
+ This action allows you to block server headers for which no
+ dedicated Privoxy action exists. Privoxy will remove every server
+ header that contains the string you supplied as parameter.
+
+ Regular expressions are not supported and you can't use this
+ action to block different headers in the same request, unless they
+ contain the same string.
+
+ crunch-server-header is only meant for quick tests. If you have to
+ block several different headers, or only want to modify parts of
+ them, you should use a custom server-header filter.
+
+ +---------------------------------------------------------+
+ | Warning |
+ |---------------------------------------------------------|
+ | Don't block any header without understanding the |
+ | consequences. |
+ +---------------------------------------------------------+
+
+ Example usage (section):
+
+ # Crunch server headers that try to prevent caching
+ { +crunch-server-header{no-cache} }
+ /
+
+ --------------------------------------------------------------------------
+
+ 8.5.10. crunch-outgoing-cookies
+
+ Typical use:
+
+ Prevent the web server from reading any HTTP cookies from your
+ system
+
+ Effect:
+
+ Deletes any "Cookie:" HTTP headers from client requests.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ This action is only concerned with outgoing HTTP cookies. For
+ incoming HTTP cookies, use crunch-incoming-cookies. Use both to
+ disable HTTP cookies completely.
+
+ It makes no sense at all to use this action in conjunction with
+ the session-cookies-only action, since it would prevent the
+ session cookies from being read.
+
+ Example usage:
+
+ +crunch-outgoing-cookies
+
+ --------------------------------------------------------------------------
+
+ 8.5.11. deanimate-gifs
+
+ Typical use:
+
+ Stop those annoying, distracting animated GIF images.
+
+ Effect:
+
+ De-animate GIF animations, i.e. reduce them to their first or last
+ image.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ "last" or "first"
+
+ Notes:
+
+ This will also shrink the images considerably (in bytes, not
+ pixels!). If the option "first" is given, the first frame of the
+ animation is used as the replacement. If "last" 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).
+
+ You can safely use this action with patterns that will also match
+ non-GIF objects, because no attempt will be made at anything that
+ doesn't look like a GIF.
+
+ Example usage:
+
+ +deanimate-gifs{last}
+
+ --------------------------------------------------------------------------
+
+ 8.5.12. downgrade-http-version
+
+ Typical use:
+
+ Work around (very rare) problems with HTTP/1.1
+
+ Effect:
+
+ Downgrades HTTP/1.1 client requests and server replies to
+ HTTP/1.0.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ This is a left-over from the time when Privoxy didn't support
+ important HTTP/1.1 features well. It is left here for the unlikely
+ case that you experience HTTP/1.1 related problems with some
+ server out there. Not all HTTP/1.1 features and requirements are
+ supported yet, so there is a chance you might need this action.
+
+ Example usage (section):
+
+ {+downgrade-http-version}
+ problem-host.example.com
+
+ --------------------------------------------------------------------------
+
+ 8.5.13. fast-redirects
+
+ Typical use:
+
+ Fool some click-tracking scripts and speed up indirect links.
+
+ Effect:
+
+ Detects redirection URLs and redirects the browser without
+ contacting the redirection server first.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ * "simple-check" to just search for the string "http://" to
+ detect redirection URLs.
+
+ * "check-decoded-url" to decode URLs (if necessary) before
+ searching for redirection URLs.
+
+ Notes:
+
+ Many sites, like yahoo.com, don't just link to other sites.
+ Instead, they will link to some script on their own servers,
+ giving the destination as a parameter, which will then redirect
+ you to the final target. URLs resulting from this scheme typically
+ look like:
+ "http://www.example.org/click-tracker.cgi?target=http%3a//www.example.net/".
+
+ Sometimes, there are even multiple consecutive redirects encoded
+ in the URL. These redirections via scripts make your web browsing
+ more traceable, since the server from which you follow such a link
+ can see where you go to. Apart from that, valuable bandwidth and
+ time is wasted, while your browser asks the server for one
+ redirect after the other. Plus, it feeds the advertisers.
+
+ This feature is currently not very smart and is scheduled for
+ improvement. If it is enabled by default, you will have to create
+ some exceptions to this action. It can lead to failures in several
+ ways:
+
+ Not every URLs with other URLs as parameters is evil. Some sites
+ offer a real service that requires this information to work. For
+ example a validation service needs to know, which document to
+ validate. fast-redirects assumes that every URL parameter that
+ looks like another URL is a redirection target, and will always
+ redirect to the last one. Most of the time the assumption is
+ correct, but if it isn't, the user gets redirected anyway.
+
+ Another failure occurs if the URL contains other parameters after
+ the URL parameter. The URL:
+ "http://www.example.org/?redirect=http%3a//www.example.net/&foo=bar".
+ contains the redirection URL "http://www.example.net/", followed
+ by another parameter. fast-redirects doesn't know that and will
+ cause a redirect to "http://www.example.net/&foo=bar". Depending
+ on the target server configuration, the parameter will be silently
+ ignored or lead to a "page not found" error. You can prevent this
+ problem by first using the redirect action to remove the last part
+ of the URL, but it requires a little effort.
+
+ To detect a redirection URL, fast-redirects only looks for the
+ string "http://", either in plain text (invalid but often used) or
+ encoded as "http%3a//". Some sites use their own URL encoding
+ scheme, encrypt the address of the target server or replace it
+ with a database id. In theses cases fast-redirects is fooled and
+ the request reaches the redirection server where it probably gets
+ logged.
+
+ Example usage:
+
+ { +fast-redirects{simple-check} }
+ one.example.com
+
+ { +fast-redirects{check-decoded-url} }
+ another.example.com/testing
+
+ --------------------------------------------------------------------------
+
+ 8.5.14. filter
+
+ Typical use:
+
+ Get rid of HTML and JavaScript annoyances, banner advertisements
+ (by size), do fun text replacements, add personalized effects,
+ etc.
+
+ Effect:
+
+ All instances of text-based type, most notably HTML and
+ JavaScript, to which this action applies, can be filtered
+ on-the-fly through the specified regular expression based
+ substitutions. (Note: as of version 3.0.3 plain text documents are
+ exempted from filtering, because web servers often use the
+ text/plain MIME type for all files whose type they don't know.)
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ The name of a content filter, as defined in the filter file.
+ Filters can be defined in one or more files as defined by the
+ filterfile option in the config file. default.filter is the
+ collection of filters supplied by the developers. Locally defined
+ filters should go in their own file, such as user.filter.
+
+ When used in its negative form, and without parameters, all
+ filtering is completely disabled.
+
+ Notes:
+
+ For your convenience, there are a number of pre-defined filters
+ available in the distribution filter file that you can use. See
+ the examples below for a list.
+
+ Filtering requires buffering the page content, which may appear to
+ slow down page rendering since nothing is displayed until all
+ content has passed the filters. (It does not really take longer,
+ but seems that way since the page is not incrementally displayed.)
+ This effect will be more noticeable on slower connections.
+
+ "Rolling your own" filters requires a knowledge of "Regular
+ Expressions" and "HTML". This is very powerful feature, and
+ potentially very intrusive. Filters should be used with caution,
+ and where an equivalent "action" is not available.
+
+ The amount of data that can be filtered is limited to the
+ buffer-limit option in the main config file. The default is 4096
+ KB (4 Megs). Once this limit is exceeded, the buffered data, and
+ all pending data, is passed through unfiltered.
+
+ Inappropriate MIME types, such as zipped files, are not filtered
+ at all. (Again, only text-based types except plain text).
+ Encrypted SSL data (from HTTPS servers) cannot be filtered either,
+ since this would violate the integrity of the secure transaction.
+ In some situations it might be necessary to protect certain text,
+ like source code, from filtering by defining appropriate -filter
+ exceptions.
+
+ Compressed content can't be filtered either, unless Privoxy is
+ compiled with zlib support (requires at least Privoxy 3.0.7), in
+ which case Privoxy will decompress the content before filtering
+ it.
+
+ If you use a Privoxy version without zlib support, but want
+ filtering to work on as much documents as possible, even those
+ that would normally be sent compressed, you must use the
+ prevent-compression action in conjunction with filter.
+
+ Content filtering can achieve some of the same effects as the
+ block action, i.e. it can be used to block ads and banners. But
+ the mechanism works quite differently. One effective use, is to
+ block ad banners based on their size (see below), since many of
+ these seem to be somewhat standardized.
+
+ Feedback with suggestions for new or improved filters is
+ particularly welcome!
+
+ The below list has only the names and a one-line description of
+ each predefined filter. There are more verbose explanations of
+ what these filters do in the filter file chapter.
+
+ Example usage (with filters from the distribution default.filter file).
+ See the Predefined Filters section for more explanation on each:
+
++filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse
+
++filter{js-events} # Kill all JS event bindings (Radically destructive! Only for extra nasty sites)
+
+ +filter{html-annoyances} # Get rid of particularly annoying HTML abuse
+
+ +filter{content-cookies} # Kill cookies that come in the HTML or JS content
+
++filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups)
+
++filter{unsolicited-popups} # Disable only unsolicited pop-up windows. Useful if your browser lacks this ability.
+
++filter{all-popups} # Kill all popups in JavaScript and HTML. Useful if your browser lacks this ability.
+
++filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective
+
+ +filter{banners-by-size} # Kill banners by size
+
++filter{banners-by-link} # Kill banners by their links to known clicktrackers
+
++filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking)
+
++filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap
+
++filter{jumping-windows} # Prevent windows from resizing and moving themselves
+
+ +filter{frameset-borders} # Give frames a border and make them resizeable
+
+ +filter{demoronizer} # Fix MS's non-standard use of standard charsets
+
+ +filter{shockwave-flash} # Kill embedded Shockwave Flash objects
+
+ +filter{quicktime-kioskmode} # Make Quicktime movies savable
+
+ +filter{fun} # Text replacements for subversive browsing fun!
+
+ +filter{crude-parental} # Crude parental filtering (demo only)
+
+ +filter{ie-exploits} # Disable a known Internet Explorer bug exploits
+
++filter{site-specifics} # Custom filters for specific site related problems
+
++filter{google} # Removes text ads and other Google specific improvements
+
++filter{yahoo} # Removes text ads and other Yahoo specific improvements
+
++filter{msn} # Removes text ads and other MSN specific improvements
+
+ +filter{blogspot} # Cleans up Blogspot blogs
+
++filter{no-ping} # Removes non-standard ping attributes from anchor and area tags
+
+ --------------------------------------------------------------------------
+
+ 8.5.15. force-text-mode
+
+ Typical use:
+
+ Force Privoxy to treat a document as if it was in some kind of
+ text format.
+
+ Effect:
+
+ Declares a document as text, even if the "Content-Type:" isn't
+ detected as such.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ As explained above, Privoxy tries to only filter files that are in
+ some kind of text format. The same restrictions apply to
+ content-type-overwrite. force-text-mode declares a document as
+ text, without looking at the "Content-Type:" first.
+
+ +---------------------------------------------------------+
+ | Warning |
+ |---------------------------------------------------------|
+ | Think twice before activating this action. Filtering |
+ | binary data with regular expressions can cause file |
+ | damage. |
+ +---------------------------------------------------------+
+
+ Example usage:
+
+ +force-text-mode
+
+
+ --------------------------------------------------------------------------
+
+ 8.5.16. forward-override
+
+ Typical use:
+
+ Change the forwarding settings based on User-Agent or request
+ origin
+
+ Effect:
+
+ Overrules the forward directives in the configuration file.
+
+ Type:
+
+ Multi-value.
+
+ Parameter:
+
+ * "forward ." to use a direct connection without any additional
+ proxies.
+
+ * "forward 127.0.0.1:8123" to use the HTTP proxy listening at
+ 127.0.0.1 port 8123.
+
+ * "forward-socks4a 127.0.0.1:9050 ." to use the socks4a proxy
+ listening at 127.0.0.1 port 9050. Replace "forward-socks4a"
+ with "forward-socks4" to use a socks4 connection (with local
+ DNS resolution) instead.
+
+ * "forward-socks4a 127.0.0.1:9050 proxy.example.org:8000" to
+ use the socks4a proxy listening at 127.0.0.1 port 9050 to
+ reach the HTTP proxy listening at proxy.example.org port
+ 8000. Replace "forward-socks4a" with "forward-socks4" to use
+ a socks4 connection (with local DNS resolution) instead.
+
+ Notes:
+
+ This action takes parameters similar to the forward directives in
+ the configuration file, but without the URL pattern. It can be
+ used as replacement, but normally it's only used in cases where
+ matching based on the request URL isn't sufficient.
+
+ +---------------------------------------------------------+
+ | Warning |
+ |---------------------------------------------------------|
+ | Please read the description for the forward directives |
+ | before using this action. Forwarding to the wrong |
+ | people will reduce your privacy and increase the |
+ | chances of man-in-the-middle attacks. |
+ | |
+ | If the ports are missing or invalid, default values |
+ | will be used. This might change in the future and you |
+ | shouldn't rely on it. Otherwise incorrect syntax causes |
+ | Privoxy to exit. |
+ | |
+ | Use the show-url-info CGI page to verify that your |
+ | forward settings do what you thought the do. |
+ +---------------------------------------------------------+
+
+ Example usage:
+
+ # Always use direct connections for requests previously tagged as
+ # "User-Agent: fetch libfetch/2.0" and make sure
+ # resuming downloads continues to work.
+ # This way you can continue to use Tor for your normal browsing,
+ # without overloading the Tor network with your FreeBSD ports updates
+ # or downloads of bigger files like ISOs.
+ # Note that HTTP headers are easy to fake and therefore their
+ # values are as (un)trustworthy as your clients and users.
+ {+forward-override{forward .} \
+ -hide-if-modified-since \
+ -overwrite-last-modified \
+ }
+ TAG:^User-Agent: fetch libfetch/2\.0$
+
+
+ --------------------------------------------------------------------------
+
+ 8.5.17. handle-as-empty-document
+
+ Typical use:
+
+ Mark URLs that should be replaced by empty documents if they get
+ blocked
+
+ Effect:
+
+ This action alone doesn't do anything noticeable. It just marks
+ URLs. If the block action also applies, the presence or absence of
+ this mark decides whether an HTML "BLOCKED" page, or an empty
+ document will be sent to the client as a substitute for the
+ blocked content. The empty document isn't literally empty, but
+ actually contains a single space.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ Some browsers complain about syntax errors if JavaScript documents
+ are blocked with Privoxy's default HTML page; this option can be
+ used to silence them. And of course this action can also be used
+ to eliminate the Privoxy BLOCKED message in frames.
+
+ The content type for the empty document can be specified with
+ content-type-overwrite{}, but usually this isn't necessary.
+
+ Example usage:
+
+ # Block all documents on example.org that end with ".js",
+ # but send an empty document instead of the usual HTML message.
+ {+block +handle-as-empty-document}
+ example.org/.*\.js$
+
+
+ --------------------------------------------------------------------------
+
+ 8.5.18. handle-as-image
+
+ Typical use:
+
+ Mark URLs as belonging to images (so they'll be replaced by images
+ if they do get blocked, rather than HTML pages)
+
+ Effect:
+
+ This action alone doesn't do anything noticeable. It just marks
+ URLs as images. If the block action also applies, the presence or
+ absence of this mark decides whether an HTML "blocked" page, or a
+ replacement image (as determined by the set-image-blocker action)
+ will be sent to the client as a substitute for the blocked
+ content.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ The below generic example section is actually part of
+ default.action. It marks all URLs with well-known image file name
+ extensions as images and should be left intact.
+
+ Users will probably only want to use the handle-as-image action in
+ conjunction with block, to block sources of banners, whose URLs
+ don't reflect the file type, like in the second example section.
+
+ Note that you cannot treat HTML pages as images in most cases. For
+ instance, (in-line) ad frames require an HTML page to be sent, or
+ they won't display properly. Forcing handle-as-image in this
+ situation will not replace the ad frame with an image, but lead to
+ error messages.
+
+ Example usage (sections):
+
+ # Generic image extensions:
+ #
+ {+handle-as-image}
+ /.*\.(gif|jpg|jpeg|png|bmp|ico)$
+
+ # These don't look like images, but they're banners and should be
+ # blocked as images:
+ #
+ {+block +handle-as-image}
+ some.nasty-banner-server.com/junk.cgi\?output=trash
+
+ # Banner source! Who cares if they also have non-image content?
+ ad.doubleclick.net
+
+ --------------------------------------------------------------------------
+
+ 8.5.19. hide-accept-language
+
+ Typical use:
+
+ Pretend to use different language settings.
+
+ Effect:
+
+ Deletes or replaces the "Accept-Language:" HTTP header in client
+ requests.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ Keyword: "block", or any user defined value.
+
+ Notes:
+
+ Faking the browser's language settings can be useful to make a
+ foreign User-Agent set with hide-user-agent more believable.
+
+ However some sites with content in different languages check the
+ "Accept-Language:" to decide which one to take by default.
+ Sometimes it isn't possible to later switch to another language
+ without changing the "Accept-Language:" header first.
+
+ Therefore it's a good idea to either only change the
+ "Accept-Language:" header to languages you understand, or to
+ languages that aren't wide spread.
+
+ Before setting the "Accept-Language:" header to a rare language,
+ you should consider that it helps to make your requests unique and
+ thus easier to trace. If you don't plan to change this header
+ frequently, you should stick to a common language.
+
+ Example usage (section):
+
+# Pretend to use Canadian language settings.
+{+hide-accept-language{en-ca} \
++hide-user-agent{Mozilla/5.0 (X11; U; OpenBSD i386; en-CA; rv:1.8.0.4) Gecko/20060628 Firefox/1.5.0.4} \
+}
+/
+
+ --------------------------------------------------------------------------
+
+ 8.5.20. hide-content-disposition
+
+ Typical use:
+
+ Prevent download menus for content you prefer to view inside the
+ browser.
+
+ Effect:
+
+ Deletes or replaces the "Content-Disposition:" HTTP header set by
+ some servers.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ Keyword: "block", or any user defined value.
+
+ Notes:
+
+ Some servers set the "Content-Disposition:" HTTP header for
+ documents they assume you want to save locally before viewing
+ them. The "Content-Disposition:" header contains the file name the
+ browser is supposed to use by default.
+
+ In most browsers that understand this header, it makes it
+ impossible to just view the document, without downloading it
+ first, even if it's just a simple text file or an image.
+
+ Removing the "Content-Disposition:" header helps to prevent this
+ annoyance, but some browsers additionally check the
+ "Content-Type:" header, before they decide if they can display a
+ document without saving it first. In these cases, you have to
+ change this header as well, before the browser stops displaying
+ download menus.
+
+ It is also possible to change the server's file name suggestion to
+ another one, but in most cases it isn't worth the time to set it
+ up.
+
+ This action will probably be removed in the future, use
+ server-header filters instead.
+
+ Example usage:
+
+ # Disarm the download link in Sourceforge's patch tracker
+ { -filter \
+ +content-type-overwrite{text/plain}\
+ +hide-content-disposition{block} }
+ .sourceforge.net/tracker/download\.php
+
+ --------------------------------------------------------------------------
+
+ 8.5.21. hide-if-modified-since
+
+ Typical use:
+
+ Prevent yet another way to track the user's steps between
+ sessions.
+
+ Effect:
+
+ Deletes the "If-Modified-Since:" HTTP client header or modifies
+ its value.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ Keyword: "block", or a user defined value that specifies a range
+ of hours.
+
+ Notes:
+
+ Removing this header is useful for filter testing, where you want
+ to force a real reload instead of getting status code "304", which
+ would cause the browser to use a cached copy of the page.
+
+ Instead of removing the header, hide-if-modified-since can also
+ add or subtract a random amount of time to/from the header's
+ value. You specify a range of minutes where the random factor
+ should be chosen from and Privoxy does the rest. A negative value
+ means subtracting, a positive value adding.
+
+ Randomizing the value of the "If-Modified-Since:" makes it less
+ likely that the server can use the time as a cookie replacement,
+ but you will run into caching problems if the random range is too
+ high.
+
+ It is a good idea to only use a small negative value and let
+ overwrite-last-modified handle the greater changes.
+
+ It is also recommended to use this action together with
+ crunch-if-none-match, otherwise it's more or less pointless.
+
+ Example usage (section):
+
+ # Let the browser revalidate but make tracking based on the time less likely.
+ {+hide-if-modified-since{-60} \
+ +overwrite-last-modified{randomize} \
+ +crunch-if-none-match}
+ /
+
+ --------------------------------------------------------------------------
+
+ 8.5.22. hide-forwarded-for-headers
+
+ Typical use:
+
+ Improve privacy by not forwarding the source of the request in the
+ HTTP headers.
+
+ Effect:
+
+ Deletes any existing "X-Forwarded-for:" HTTP header from client
+ requests.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ It is safe and recommended to leave this on.
+
+ Example usage:
+
+ +hide-forwarded-for-headers
+
+ --------------------------------------------------------------------------
+
+ 8.5.23. hide-from-header
+
+ Typical use:
+
+ Keep your (old and ill) browser from telling web servers your
+ email address
+
+ Effect:
+
+ Deletes any existing "From:" HTTP header, or replaces it with the
+ specified string.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ Keyword: "block", or any user defined value.
+
+ Notes:
+
+ The keyword "block" will completely remove the header (not to be
+ confused with the block action).
+
+ Alternately, you can specify any value you prefer to be sent to
+ the web server. If you do, it is a matter of fairness not to use
+ any address that is actually used by a real person.
+
+ This action is rarely needed, as modern web browsers don't send
+ "From:" headers anymore.
+
+ Example usage:
+
+ +hide-from-header{block}
+
+ or
+
+ +hide-from-header{spam-me-senseless@sittingduck.example.com}
+
+ --------------------------------------------------------------------------
+
+ 8.5.24. hide-referrer
+
+ Typical use:
+
+ Conceal which link you followed to get to a particular site
+
+ Effect:
+
+ Deletes the "Referer:" (sic) HTTP header from the client request,
+ or replaces it with a forged one.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ * "conditional-block" to delete the header completely if the
+ host has changed.
+
+ * "conditional-forge" to forge the header if the host has
+ changed.
+
+ * "block" to delete the header unconditionally.
+
+ * "forge" to pretend to be coming from the homepage of the
+ server we are talking to.
+
+ * Any other string to set a user defined referrer.
+
+ Notes:
+
+ conditional-block is the only parameter, that isn't easily
+ detected in the server's log file. If it blocks the referrer, the
+ request will look like the visitor used a bookmark or typed in the
+ address directly.
+
+ Leaving the referrer unmodified for requests on the same host
+ allows the server owner to see the visitor's "click path", but in
+ most cases she could also get that information by comparing other
+ parts of the log file: for example the User-Agent if it isn't a
+ very common one, or the user's IP address if it doesn't change
+ between different requests.
+
+ Always blocking the referrer, or using a custom one, can lead to
+ failures on servers that check the referrer before they answer any
+ requests, in an attempt to prevent their content from being
+ embedded or linked to elsewhere.
+
+ Both conditional-block and forge will work with referrer checks,
+ as long as content and valid referring page are on the same host.
+ Most of the time that's the case.
+
+ hide-referer is an alternate spelling of hide-referrer and the two
+ can be can be freely substituted with each other. ("referrer" is
+ the correct English spelling, however the HTTP specification has a
+ bug - it requires it to be spelled as "referer".)
+
+ Example usage:
+
+ +hide-referrer{forge}
+
+ or
+
+ +hide-referrer{http://www.yahoo.com/}
+
+ --------------------------------------------------------------------------
+
+ 8.5.25. hide-user-agent
+
+ Typical use:
+
+ Try to conceal your type of browser and client operating system
+
+ Effect:
+
+ Replaces the value of the "User-Agent:" HTTP header in client
+ requests with the specified value.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ Any user-defined string.
+
+ Notes:
+
+ +---------------------------------------------------------+
+ | Warning |
+ |---------------------------------------------------------|
+ | This can lead to problems on web sites that depend on |
+ | looking at this header in order to customize their |
+ | content for different browsers (which, by the way, is |
+ | NOT the right thing to do: good web sites work |
+ | browser-independently). |
+ +---------------------------------------------------------+
+
+ Using this action in multi-user setups or wherever different types
+ of browsers will access the same Privoxy is not recommended. In
+ single-user, single-browser setups, you might use it to delete
+ your OS version information from the headers, because it is an
+ invitation to exploit known bugs for your OS. It is also
+ occasionally useful to forge this in order to access sites that
+ won't let you in otherwise (though there may be a good reason in
+ some cases). Example of this: some MSN sites will not let Mozilla
+ enter, yet forging to a Netscape 6.1 user-agent works just fine.
+ (Must be just a silly MS goof, I'm sure :-).
+
+ More information on known user-agent strings can be found at
+ http://www.user-agents.org/ and
+ http://en.wikipedia.org/wiki/User_agent.
+
+ Example usage:
+
+ +hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}
+
+ --------------------------------------------------------------------------
+
+ 8.5.26. inspect-jpegs
+
+ Typical use:
+
+ Try to protect against a MS buffer over-run in JPEG processing
+
+ Effect:
+
+ Protect against a known exploit
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ See Microsoft Security Bulletin MS04-028. JPEG images are one of
+ the most common image types found across the Internet. The exploit
+ as described can allow execution of code on the target system,
+ giving an attacker access to the system in question by merely
+ planting an altered JPEG image, which would have no obvious
+ indications of what lurks inside. This action tries to prevent
+ this exploit if delivered through unencrypted HTTP.
+
+ Note that the exploit mentioned is several years old and it's
+ unlikely that your client is still vulnerable against it. This
+ action may be removed in one of the next releases.
+
+ Example usage:
+
+ +inspect-jpegs
+
+ --------------------------------------------------------------------------
+
+ 8.5.27. kill-popups
+
+ Typical use:
+
+ Eliminate those annoying pop-up windows (deprecated)
+
+ Effect:
+
+ While loading the document, replace JavaScript code that opens
+ pop-up windows with (syntactically neutral) dummy code on the fly.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ This action is basically a built-in, hardwired special-purpose
+ filter action, but there are important differences: For
+ kill-popups, the document need not be buffered, so it can be
+ incrementally rendered while downloading. But kill-popups doesn't
+ catch as many pop-ups as filter{all-popups} does and is not as
+ smart as filter{unsolicited-popups} is.
+
+ Think of it as a fast and efficient replacement for a filter that
+ you can use if you don't want any filtering at all. Note that it
+ doesn't make sense to combine it with any filter action, since as
+ soon as one filter applies, the whole document needs to be
+ buffered anyway, which destroys the advantage of the kill-popups
+ action over its filter equivalent.
+
+ Killing all pop-ups unconditionally is problematic. Many shops and
+ banks rely on pop-ups to display forms, shopping carts etc, and
+ the filter{unsolicited-popups} does a better job of catching only
+ the unwanted ones.
+
+ If the only kind of pop-ups that you want to kill are exit
+ consoles (those really nasty windows that appear when you close an
+ other one), you might want to use filter{js-annoyances} instead.
+
+ This action is most appropriate for browsers that don't have any
+ controls for unwanted pop-ups. Not recommended for general usage.
+
+ This action doesn't work very reliable and may be removed in
+ future releases.
+
+ Example usage:
+
+ +kill-popups
+
+ --------------------------------------------------------------------------
+
+ 8.5.28. limit-connect
+
+ Typical use:
+
+ Prevent abuse of Privoxy as a TCP proxy relay or disable SSL for
+ untrusted sites
+
+ Effect:
+
+ Specifies to which ports HTTP CONNECT requests are allowable.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ A comma-separated list of ports or port ranges (the latter using
+ dashes, with the minimum defaulting to 0 and the maximum to 65K).
+
+ Notes:
+
+ By default, i.e. if no limit-connect action applies, Privoxy only
+ allows HTTP CONNECT requests to port 443 (the standard, secure
+ HTTPS port). Use limit-connect if more fine-grained control is
+ desired for some or all destinations.
+
+ 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 and to the remote
+ server. This means CONNECT-enabled proxies can be used as TCP
+ relays very easily.
+
+ Privoxy relays HTTPS traffic without seeing the decoded content.
+ Websites can leverage this limitation to circumvent Privoxy's
+ filters. By specifying an invalid port range you can disable HTTPS
+ entirely. If you plan to disable SSL by default, consider enabling
+ treat-forbidden-connects-like-blocks as well, to be able to
+ quickly create exceptions.
+
+ Example usages:
+
++limit-connect{443} # This is the default and need not be specified.
++limit-connect{80,443} # Ports 80 and 443 are OK.
++limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
++limit-connect{-} # All ports are OK
++limit-connect{,} # No HTTPS/SSL traffic is allowed
+
+ --------------------------------------------------------------------------
+
+ 8.5.29. prevent-compression
+
+ Typical use:
+
+ Ensure that servers send the content uncompressed, so it can be
+ passed through filters.
+
+ Effect:
+
+ Removes the Accept-Encoding header which can be used to ask for
+ compressed transfer.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ More and more websites send their content compressed by default,
+ which is generally a good idea and saves bandwidth. But the
+ filter, deanimate-gifs and kill-popups actions need access to the
+ uncompressed data.
+
+ When compiled with zlib support (available since Privoxy 3.0.7),
+ content that should be filtered is decompressed on-the-fly and you
+ don't have to worry about this action. If you are using an older
+ Privoxy version, or one that hasn't been compiled with zlib
+ support, this action can be used to convince the server to send
+ the content uncompressed.
+
+ Most text-based instances compress very well, the size is seldom
+ decreased by less than 50%, for markup-heavy instances like news
+ feeds saving more than 90% of the original size isn't unusual.
+
+ Not using compression will therefore slow down the transfer, and
+ you should only enable this action if you really need it. As of
+ Privoxy 3.0.7 it's disabled in all predefined action settings.
+
+ Note that some (rare) ill-configured sites don't handle requests
+ for uncompressed documents correctly. Broken PHP applications tend
+ to send an empty document body, some IIS versions only send the
+ beginning of the content. If you enable prevent-compression per
+ default, you might want to add exceptions for those sites. See the
+ example for how to do that.
-2. Installation
+ Example usage (sections):
-Privoxy is available both in convenient pre-compiled packages for a wide range
-of operating systems, and as raw source code. For most users, we recommend
-using the packages, which can be downloaded from our Privoxy Project Page.
+ # Selectively turn off compression, and enable a filter
+ #
+ { +filter{tiny-textforms} +prevent-compression }
+ # Match only these sites
+ .google.
+ sourceforge.net
+ sf.net
-Note: If you have a previous Junkbuster or Privoxy installation on your system,
-you will need to remove it. Some platforms do this for you as part of their
-installation procedure. (See below for your platform). In any case be sure to
-backup your old configuration if it is valuable to you. See the note to
-upgraders section below.
+ # Or instead, we could set a universal default:
+ #
+ { +prevent-compression }
+ / # Match all sites
--------------------------------------------------------------------------------
+ # Then maybe make exceptions for broken sites:
+ #
+ { -prevent-compression }
+ .compusa.com/
-2.1. Binary Packages
+ --------------------------------------------------------------------------
-How to install the binary packages depends on your operating system:
+ 8.5.30. overwrite-last-modified
--------------------------------------------------------------------------------
+ Typical use:
-2.1.1. Red Hat and SuSE RPMs
+ Prevent yet another way to track the user's steps between
+ sessions.
-RPMs can be installed with rpm -Uvh privoxy-2.9.15-1.rpm, and will use /etc/
-privoxy for the location of configuration files.
+ Effect:
-Note that on Red Hat, Privoxy will not be automatically started on system boot.
-You will need to enable that using chkconfig, ntsysv, or similar methods. Note
-that SuSE will automatically start Privoxy in the boot process.
+ Deletes the "Last-Modified:" HTTP server header or modifies its
+ value.
-If you have problems with failed dependencies, try rebuilding the SRC RPM: rpm
---rebuild privoxy-2.9.15-1.src.rpm;. This will use your locally installed
-libraries and RPM version.
+ Type:
-Also note that if you have a Junkbuster RPM installed on your system, you need
-to remove it first, because the packages conflict. Otherwise, RPM will try to
-remove Junkbuster automatically, before installing Privoxy.
+ Parameterized.
--------------------------------------------------------------------------------
+ Parameter:
-2.1.2. Debian
+ One of the keywords: "block", "reset-to-request-time" and
+ "randomize"
-FIXME.
+ Notes:
--------------------------------------------------------------------------------
+ Removing the "Last-Modified:" header is useful for filter testing,
+ where you want to force a real reload instead of getting status
+ code "304", which would cause the browser to reuse the old version
+ of the page.
-2.1.3. Windows
+ The "randomize" option overwrites the value of the
+ "Last-Modified:" header with a randomly chosen time between the
+ original value and the current time. In theory the server could
+ send each document with a different "Last-Modified:" header to
+ track visits without using cookies. "Randomize" makes it
+ impossible and the browser can still revalidate cached documents.
-Just double-click the installer, which will guide you through the installation
-process. You will find the configuration files in the same directory as you
-installed Privoxy in. We do not use the registry of Windows.
+ "reset-to-request-time" overwrites the value of the
+ "Last-Modified:" header with the current time. You could use this
+ option together with hided-if-modified-since to further customize
+ your random range.
--------------------------------------------------------------------------------
+ The preferred parameter here is "randomize". It is safe to use, as
+ long as the time settings are more or less correct. If the server
+ sets the "Last-Modified:" header to the time of the request, the
+ random range becomes zero and the value stays the same. Therefore
+ you should later randomize it a second time with
+ hided-if-modified-since, just to be sure.
-2.1.4. Solaris, NetBSD, FreeBSD, HP-UX
+ It is also recommended to use this action together with
+ crunch-if-none-match.
-Create a new directory, cd to it, then unzip and untar the archive. For the
-most part, you'll have to figure out where things go. FIXME.
+ Example usage:
--------------------------------------------------------------------------------
+ # Let the browser revalidate without being tracked across sessions
+ { +hide-if-modified-since{-60} \
+ +overwrite-last-modified{randomize} \
+ +crunch-if-none-match}
+ /
-2.1.5. OS/2
+ --------------------------------------------------------------------------
-First, make sure that no previous installations of Junkbuster and / or Privoxy
-are left on your system. You can do this by
+ 8.5.31. redirect
-Then, just double-click the WarpIN self-installing archive, which will guide
-you through the installation process. A shadow of the Privoxy executable will
-be placed in your startup folder so it will start automatically whenever OS/2
-starts.
+ Typical use:
-The directory you choose to install Privoxy into will contain all of the
-configuration files.
+ Redirect requests to other sites.
--------------------------------------------------------------------------------
+ Effect:
-2.1.6. Max OSX
+ Convinces the browser that the requested document has been moved
+ to another location and the browser should get it from there.
-Unzip the downloaded package (you can either double-click on the file in the
-finder, or on the desktop if you downloaded it there). Then, double-click on
-the package installer icon and follow the installation process. Privoxy will be
-installed in the subdirectory /Applications/Privoxy.app. Privoxy will set
-itself up to start automatically on system bring-up via /System/Library/
-StartupItems/Privoxy.
+ Type:
--------------------------------------------------------------------------------
+ Parameterized
-2.1.7. AmigaOS
+ Parameter:
-Copy and then unpack the lha archive to a suitable location. All necessary
-files will be installed into Privoxy directory, including all configuration and
-log files. To uninstall, just remove this directory.
+ An absolute URL or a single pcrs command.
-Start Privoxy (with RUN <>NIL:) in your startnet script (AmiTCP), in s:
-user-startup (RoadShow), as startup program in your startup script (Genesis),
-or as startup action (Miami and MiamiDx). Privoxy will automatically quit when
-you quit your TCP/IP stack (just ignore the harmless warning your TCP/IP stack
-may display that Privoxy is still running).
+ Notes:
--------------------------------------------------------------------------------
+ Requests to which this action applies are answered with a HTTP
+ redirect to URLs of your choosing. The new URL is either provided
+ as parameter, or derived by applying a single pcrs command to the
+ original URL.
-2.2. Building from Source
+ This action will be ignored if you use it together with block. It
+ can be combined with fast-redirects{check-decoded-url} to redirect
+ to a decoded version of a rewritten URL.
-The most convenient way to obtain the Privoxy sources is to download the source
-tarball from our project page.
+ Use this action carefully, make sure not to create redirection
+ loops and be aware that using your own redirects might make it
+ possible to fingerprint your requests.
-If you like to live on the bleeding edge and are not afraid of using possibly
-unstable development versions, you can check out the up-to-the-minute version
-directly from the CVS repository or simply download the nightly CVS tarball.
+ Example usages:
-To build Privoxy from source, autoconf, GNU make (gmake), and, of course, a C
-compiler like gcc are required.
+ # Replace example.com's style sheet with another one
+ { +redirect{http://localhost/css-replacements/example.com.css} }
+ example.com/stylesheet\.css
-When building from a source tarball (either release version or nightly CVS
-tarball), first unpack the source:
+ # Create a short, easy to remember nickname for a favorite site
+ # (relies on the browser accept and forward invalid URLs to Privoxy)
+ { +redirect{http://www.privoxy.org/user-manual/actions-file.html} }
+ a
- tar xzvf privoxy-2.9.15-beta-src* [.tgz or .tar.gz]
- cd privoxy-2.9.15-beta
+ # Always use the expanded view for Undeadly.org articles
+ # (Note the $ at the end of the URL pattern to make sure
+ # the request for the rewritten URL isn't redirected as well)
+ {+redirect{s@$@&mode=expanded@}}
+ undeadly.org/cgi\?action=article&sid=\d*$
-For retrieving the current CVS sources, you'll need CVS installed. Note that
-sources from CVS are development quality, and may not be stable, or well
-tested. To download CVS source:
+ --------------------------------------------------------------------------
- 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
+ 8.5.32. send-vanilla-wafer
-This will create a directory named current/, which will contain the source
-tree.
+ Typical use:
-Then, in either case, to build from unpacked tarball or CVS source:
+ Feed log analysis scripts with useless data.
- autoheader
- autoconf
- ./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)
+ Effect:
-If you have gnu make, you can have the first four steps automatically done for
-you by just typing:
+ Sends a cookie with each request stating that you do not accept
+ any copyright on cookies sent to you, and asking the site operator
+ not to track you.
- make
+ Type:
-in the freshly downloaded or unpacked source directory.
+ Boolean.
-For more detailed instructions on how to build Redhat and SuSE RPMs, Windows
-self-extracting installers, building on platforms with special requirements
-etc, please consult the developer manual.
+ Parameter:
--------------------------------------------------------------------------------
+ N/A
-3. Note to Upgraders
+ Notes:
-There are very significant changes from earlier Junkbuster versions to the
-current Privoxy. The number, names, syntax, and purposes of configuration files
-have substantially changed. Junkbuster 2.0.x configuration files will not
-migrate, Junkbuster 2.9.x and Privoxy configurations will need to be ported.
-The functionalities of the old blockfile, cookiefile and imagelist are now
-combined into the "actions files". default.action, is the main actions file.
-Local exceptions should best be put into user.action.
+ The vanilla wafer is a (relatively) unique header and could
+ conceivably be used to track you.
-A "filter file" (typically default.filter) is new as of Privoxy 2.9.x, and
-provides some of the new sophistication (explained below). config is much the
-same as before.
+ This action is rarely used and not enabled in the default
+ configuration.
-If upgrading from a 2.0.x version, you will have to use the new config files,
-and possibly adapt any personal rules from your older files. When porting
-personal rules over from the old blockfile to the new actions files, please
-note that even the pattern syntax has changed. If upgrading from 2.9.x
-development versions, it is still recommended to use the new configuration
-files.
+ Example usage:
-A quick list of things to be aware of before upgrading:
+ +send-vanilla-wafer
- * The default listening port is now 8118 due to a conflict with another
- service (NAS).
-
- * Some installers may remove earlier versions completely. Save any important
- configuration files!
-
- * Privoxy is controllable with a web browser at the special URL: http://
- config.privoxy.org/ (Shortcut: http://p.p/). Many aspects of configuration
- can be done here, including temporarily disabling Privoxy.
-
- * The primary configuration file for cookie management, ad and banner
- blocking, and many other aspects of Privoxy configuration is in the actions
- files. It is strongly recommended to become familiar with the new actions
- concept below, before modifying these files. Locally defined rules should
- go into user.action.
-
- * Some installers may not automatically start Privoxy after installation.
-
--------------------------------------------------------------------------------
+ --------------------------------------------------------------------------
-4. Quickstart to Using Privoxy
+ 8.5.33. send-wafer
- * If upgrading, please back up any configuration files. See the Note to
- Upgraders Section.
-
- * Install Privoxy. See the Installation Section for platform specific
- information.
-
- * Start Privoxy, if the installation program has not done this already. See
- the section Starting Privoxy.
-
- * Set your browser to use Privoxy as HTTP and HTTPS proxy by setting the
- proxy configuration for address of localhost and port 8118. (Junkbuster and
- earlier versions of Privoxy used port 8000.) See the section Starting
- Privoxy.
-
- * Flush your browser's caches, to remove any cached ad images.
-
- * Enjoy surfing with enhanced comfort and privacy. You may want to customize
- the user.action file to personalize your new browsing experience. See the
- Configuration section for more configuration options, and how to further
- customize your installation.
-
- * If you experience problems with sites that "misbehave", see the Anatomy of
- an Action section in the Appendix.
-
- * Please see the section Contacting the Developers on how to report bugs or
- problems with websites or to get help.
-
--------------------------------------------------------------------------------
+ Typical use:
-5. Starting Privoxy
+ Send custom cookies or feed log analysis scripts with even more
+ useless data.
-Before launching Privoxy for the first time, you will want to configure your
-browser(s) to use Privoxy as a HTTP and HTTPS proxy. The default is localhost
-for the proxy address, and port 8118 (earlier versions used port 8000). This is
-the one configuration step that must be done!
+ Effect:
-With Netscape (and Mozilla), this can be set under Edit -> Preferences ->
-Advanced -> Proxies -> HTTP Proxy. For Internet Explorer: Tools -> Internet
-Properties -> Connections -> LAN Setting. Then, check "Use Proxy" and fill in
-the appropriate info (Address: localhost, Port: 8118). Include if HTTPS proxy
-support too.
+ Sends a custom, user-defined cookie with each request.
-After doing this, flush your browser's disk and memory caches to force a
-re-reading of all pages and to get rid of any ads that may be cached. You are
-now ready to start enjoying the benefits of using Privoxy!
+ Type:
-Privoxy is typically started by specifying the main configuration file to be
-used on the command line. If no configuration file is specified on the command
-line, Privoxy will look for a file named config in the current directory.
-Except on Win32 where it will try config.txt.
+ Multi-value.
--------------------------------------------------------------------------------
+ Parameter:
-5.1. RedHat and Debian
+ A string of the form "name=value".
-We use a script. Note that RedHat does not start Privoxy upon booting per
-default. It will use the file /etc/privoxy/config as its main configuration
-file. FIXME: Debian??
+ Notes:
- # /etc/rc.d/init.d/privoxy start
+ Being multi-valued, multiple instances of this action can apply to
+ the same request, resulting in multiple cookies being sent.
--------------------------------------------------------------------------------
+ This action is rarely used and not enabled in the default
+ configuration.
-5.2. SuSE
+ Example usage (section):
-We use a script. It will use the file /etc/privoxy/config as its main
-configuration file. Note that SuSE starts Privoxy upon booting your PC.
+ {+send-wafer{UsingPrivoxy=true}}
+ my-internal-testing-server.void
- # rcprivoxy start
+ --------------------------------------------------------------------------
--------------------------------------------------------------------------------
+ 8.5.34. server-header-filter
-5.3. Windows
+ Typical use:
-Click on the Privoxy Icon to start Privoxy. If no configuration file is
-specified on the command line, Privoxy will look for a file named config.txt.
-Note that Windows will automatically start Privoxy upon booting you PC.
+ Rewrite or remove single server headers.
--------------------------------------------------------------------------------
+ Effect:
-5.4. Solaris, NetBSD, FreeBSD, HP-UX and others
+ All server headers to which this action applies are filtered
+ on-the-fly through the specified regular expression based
+ substitutions.
-Example Unix startup command:
+ Type:
- # /usr/sbin/privoxy /etc/privoxy/config
+ Parameterized.
--------------------------------------------------------------------------------
+ Parameter:
-5.5. OS/2
+ The name of a server-header filter, as defined in one of the
+ filter files.
-FIXME.
+ Notes:
--------------------------------------------------------------------------------
+ Server-header filters are applied to each header on its own, not
+ to all at once. This makes it easier to diagnose problems, but on
+ the downside you can't write filters that only change header x if
+ header y's value is z. You can do that by using tags though.
-5.6. MAX OSX
+ Server-header filters are executed after the other header actions
+ have finished and use their output as input.
-FIXME.
+ Please refer to the filter file chapter to learn which
+ server-header filters are available by default, and how to create
+ your own.
--------------------------------------------------------------------------------
+ Example usage (section):
-5.7. AmigaOS
+ {+server-header-filter{html-to-xml}}
+ example.org/xml-instance-that-is-delivered-as-html
-FIXME.
+ {+server-header-filter{xml-to-html}}
+ example.org/instance-that-is-delivered-as-xml-but-is-not
--------------------------------------------------------------------------------
-5.8. Command Line Options
+ --------------------------------------------------------------------------
-Privoxy may be invoked with the following command-line options:
+ 8.5.35. server-header-tagger
- * --version
-
- Print version info and exit. Unix only.
-
- * --help
-
- Print short usage info and exit. Unix only.
-
- * --no-daemon
-
- Don't become a daemon, i.e. don't fork and become process group leader, and
- don't detach from controlling tty. Unix only.
-
- * --pidfile FILE
-
- On startup, write the process ID to FILE. Delete the FILE on exit. Failure
- to create or delete the FILE is non-fatal. If no FILE option is given, no
- PID file will be used. Unix only.
-
- * --user USER[.GROUP]
-
- After (optionally) writing the PID file, assume the user ID of USER, and if
- included the GID of GROUP. Exit if the privileges are not sufficient to do
- so. Unix only.
-
- * configfile
-
- If no configfile is included on the command line, Privoxy will look for a
- file named "config" in the current directory (except on Win32 where it will
- look for "config.txt" instead). Specify full path to avoid confusion. If no
- config file is found, Privoxy will fail to start.
-
--------------------------------------------------------------------------------
+ Typical use:
-6. Privoxy Configuration
+ Enable or disable filters based on the Content-Type header.
-All Privoxy configuration is stored in text files. These files can be edited
-with a text editor. Many important aspects of Privoxy can also be controlled
-easily with a web browser.
-
--------------------------------------------------------------------------------
-
-6.1. Controlling Privoxy with Your Web Browser
-
-Privoxy's user interface can be reached through the special URL http://
-config.privoxy.org/ (shortcut: http://p.p/), which is a built-in page and works
-without Internet access. You will see the following section:
-
- Privoxy Menu
- ? View & change the current configuration
- ? View the source code version numbers
- ? View the request headers.
- ? Look up which actions apply to a URL and why
- ? Toggle Privoxy on or off
-
-
-This should be self-explanatory. Note the first item leads to an editor for the
-actions files, which is where the ad, banner, cookie, and URL blocking magic is
-configured as well as other advanced features of Privoxy. This is an easy way
-to adjust various aspects of Privoxy configuration. The actions file, and other
-configuration files, are explained in detail below.
-
-"Toggle Privoxy On or Off" is handy for sites that might have problems with
-your current actions and filters. You can in fact use it as a test to see
-whether it is Privoxy causing the problem or not. Privoxy continues to run as a
-proxy in this case, but all manipulation is disabled, i.e. Privoxy acts like a
-normal forwarding proxy. There is even a toggle Bookmarklet offered, so that
-you can toggle Privoxy with one click from your browser.
-
--------------------------------------------------------------------------------
-
-6.2. Configuration Files Overview
-
-For Unix, *BSD and Linux, all configuration files are located in /etc/privoxy/
-by default. For MS Windows, OS/2, and AmigaOS these are all in the same
-directory as the Privoxy executable. The name and number of configuration files
-has changed from previous versions, and is subject to change as development
-progresses.
-
-The installed defaults provide a reasonable starting point, though some
-settings may be aggressive by some standards. For the time being, the principle
-configuration files are:
-
- * The main configuration file is named config on Linux, Unix, BSD, OS/2, and
- AmigaOS and config.txt on Windows. This is a required file.
-
- * default.action (the main actions file) is used to define which "actions"
- relating to banner-blocking, images, pop-ups, content modification, cookie
- handling etc should be applied by default. It also defines many exceptions
- (both positive and negative) from this default set of actions that enable
- Privoxy to selectively eliminate the junk, and only the junk, on as many
- websites as possible.
-
- Multiple actions files may be defined in config. These are processed in the
- order they are defined. Local customizations and locally preferred
- exceptions to the default policies as defined in default.action (which you
- will most propably want to define sooner or later) are probably best
- applied in user.action, where you can preserve them across upgrades.
- standard.action is for Privoxy's internal use.
-
- There is also a web based editor that can be accessed from http://
- config.privoxy.org/show-status (Shortcut: http://p.p/show-status) for the
- various actions files.
-
- * default.filter (the filter file) can be used to re-write the raw page
- content, including viewable text as well as embedded HTML and JavaScript,
- and whatever else lurks on any given web page. The filtering jobs are only
- pre-defined here; whether to apply them or not is up to the actions files.
-
-All files use the "#" character to denote a comment (the rest of the line will
-be ignored) and understand line continuation through placing a backslash ("\")
-as the very last character in a line. If the # is preceded by a backslash, it
-looses its special function. Placing a # in front of an otherwise valid
-configuration line to prevent it from being interpreted is called "commenting
-out" that line.
-
-The actions files and default.filter can use Perl style regular expressions for
-maximum flexibility.
-
-After making any changes, there is no need to restart Privoxy in order for the
-changes to take effect. Privoxy detects such changes automatically. Note,
-however, that it may take one or two additional requests for the change to take
-effect. When changing the listening address of Privoxy, these "wake up"
-requests must obviously be sent to the old listening address.
-
-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 "default" setting, may change, so please check all your
-configuration files on important issues.
-
--------------------------------------------------------------------------------
+ Effect:
-7. The Main Configuration File
+ Server headers to which this action applies are filtered
+ on-the-fly through the specified regular expression based
+ substitutions, the result is used as tag.
-Again, the main configuration file is named config on Linux/Unix/BSD and OS/2,
-and config.txt 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:
-
- confdir /etc/privoxy
-
-Assigns the value /etc/privoxy to the option confdir and thus indicates that
-the configuration directory is named "/etc/privoxy/".
-
-All options in the config file except for confdir and logdir are optional.
-Watch out in the below description for what happens if you leave them unset.
-
-The main config file controls all aspects of Privoxy's operation that are not
-location dependent (i.e. they apply universally, no matter where you may be
-surfing).
-
--------------------------------------------------------------------------------
-
-7.1. Configuration and Log File Locations
-
-Privoxy can (and normally does) use a number of other files for additional
-configuration, help and logging. This section of the configuration file tells
-Privoxy where to find those other files.
-
-The user running Privoxy, must have read permission for all configuration
-files, and write permission to any files that would be modified, such as log
-files.
-
--------------------------------------------------------------------------------
-
-7.1.1. confdir
-
-Specifies:
-
- The directory where the other configuration files are located
-
-Type of value:
-
- Path name
-
-Default value:
-
- /etc/privoxy (Unix) or Privoxy installation dir (Windows)
-
-Effect if unset:
-
- Mandatory
-
-Notes:
-
- No trailing "/", please
-
- When development goes modular and multi-user, the blocker, filter, and
- per-user config will be stored in subdirectories of "confdir". For now, the
- configuration directory structure is flat, except for confdir/templates,
- where the HTML templates for CGI output reside (e.g. Privoxy's 404 error
- page).
-
--------------------------------------------------------------------------------
-
-7.1.2. logdir
-
-Specifies:
-
- The directory where all logging takes place (i.e. where logfile and jarfile
- are located)
-
-Type of value:
-
- Path name
-
-Default value:
-
- /var/log/privoxy (Unix) or Privoxy installation dir (Windows)
-
-Effect if unset:
-
- Mandatory
-
-Notes:
-
- No trailing "/", please
-
--------------------------------------------------------------------------------
-
-7.1.3. actionsfile
-
-Specifies:
-
- The actions file(s) to use
-
-Type of value:
-
- File name, relative to confdir, without the .action suffix
-
-Default value:
-
- standard # Internal purposes, no editing recommended
-
- default # Main actions file
-
- user # User customizations
-
-Effect if unset:
-
- No actions are taken at all. Simple neutral proxying.
-
-Notes:
-
- Multiple actionsfile lines are permitted, and are in fact recommended!
-
- The default values include standard.action, which is used for internal
- purposes and should be loaded, default.action, which is the "main" actions
- file maintained by the developers, and user.action, where you can make your
- personal additions.
-
- Actions files are where all the per site and per URL configuration is done
- for ad blocking, cookie management, privacy considerations, etc. There is
- no point in using Privoxy without at least one actions file.
-
--------------------------------------------------------------------------------
-
-7.1.4. filterfile
-
-Specifies:
-
- The filter file to use
-
-Type of value:
-
- File name, relative to confdir
-
-Default value:
-
- default.filter (Unix) or default.filter.txt (Windows)
-
-Effect if unset:
-
- No textual content filtering takes place, i.e. all +filter{name} actions in
- the actions files are turned neutral.
-
-Notes:
-
- The "default.filter" file contains content modification rules that use
- "regular expressions". These rules permit powerful changes on the content
- of Web pages, e.g., you could disable your favorite JavaScript annoyances,
- re-write the actual displayed text, or just have some fun replacing
- "Microsoft" with "MicroSuck" wherever it appears on a Web page.
-
--------------------------------------------------------------------------------
-
-7.1.5. logfile
-
-Specifies:
-
- The log file to use
-
-Type of value:
-
- File name, relative to logdir
-
-Default value:
-
- logfile (Unix) or privoxy.log (Windows)
-
-Effect if unset:
-
- No log file is used, all log messages go to the console (stderr).
-
-Notes:
-
- The windows version will additionally log to the console.
-
- The logfile is where all logging and error messages are written. The level
- of detail and number of messages are set with the debug option (see below).
- The logfile can be useful for tracking down a problem with Privoxy (e.g.,
- it's not blocking an ad you think it should block) but in most cases you
- probably will never look at it.
-
- 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 "man cron"). For Red Hat, a logrotate script has been included.
-
- On SuSE Linux systems, you can place a line like "/var/log/privoxy.* +1024k
- 644 nobody.nogroup" in /etc/logfiles, with the effect that cron.daily will
- automatically archive, gzip, and empty the log, when it exceeds 1M size.
-
- Any log files must be writable by whatever user Privoxy is being run as
- (default on UNIX, user id is "privoxy").
-
--------------------------------------------------------------------------------
-
-7.1.6. jarfile
-
-Specifies:
-
- The file to store intercepted cookies in
-
-Type of value:
-
- File name, relative to logdir
-
-Default value:
-
- jarfile (Unix) or privoxy.jar (Windows)
-
-Effect if unset:
-
- Intercepted cookies are not stored at all.
-
-Notes:
-
- The jarfile may grow to ridiculous sizes over time.
-
--------------------------------------------------------------------------------
-
-7.1.7. trustfile
-
-Specifies:
-
- The trust file to use
-
-Type of value:
-
- File name, relative to confdir
-
-Default value:
-
- Unset (commented out). When activated: trust (Unix) or trust.txt (Windows)
-
-Effect if unset:
-
- The whole trust mechanism is turned off.
-
-Notes:
-
- The trust mechanism is an experimental feature for building white-lists and
- should be used with care. It is NOT recommended for the casual user.
-
- If you specify a trust file, Privoxy will only allow access to sites that
- are named in the trustfile. You can also mark sites as trusted referrers
- (with +), 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 "trustfile". Possible applications include limiting Internet
- access for children.
-
- If you use + operator in the trust file, it may grow considerably over
- time.
-
--------------------------------------------------------------------------------
-
-7.2. Local Set-up Documentation
-
-If you intend to operate Privoxy for more users that just yourself, it might be
-a good idea to let them know how to reach you, what you block and why you do
-that, your policies etc.
-
--------------------------------------------------------------------------------
-
-7.2.1. user-manual
-
-Specifies:
-
- Location of the Privoxy User Manual.
-
-Type of value:
-
- A fully qualified URI
-
-Default value:
-
- Unset
-
-Effect if unset:
-
- http://www.privoxy.org/version/user-manual/ will be used, where version is
- the Privoxy version.
-
-Notes:
-
- The User Manual URI is used for help links from some of the internal CGI
- pages. The manual itself is normally packaged with the binary
- distributions, so you propably want to set this to a locally installed
- copy. For multi-user setups, you could provide a copy on a local webserver
- for all your users and use the corresponding URL here.
-
- Examples:
-
- Unix, in local filesystem:
-
- user-manual file:///usr/share/doc/privoxy-2.9.15/user-manual/
-
- Any platform, on local webserver (called "local-webserver"):
-
- user-manual http://local-webserver/privoxy-user-manual/
-
- +-----------------------------------------------------------------+
- | Warning |
- |-----------------------------------------------------------------|
- |If set, this option should be the first option in the config |
- |file, because it is used while the config file is being read. |
- +-----------------------------------------------------------------+
-
--------------------------------------------------------------------------------
-
-7.2.2. trust-info-url
-
-Specifies:
-
- A URL to be displayed in the error page that users will see if access to an
- untrusted page is denied.
-
-Type of value:
-
- URL
-
-Default value:
-
- Two example URL are provided
-
-Effect if unset:
-
- No links are displayed on the "untrusted" error page.
-
-Notes:
-
- The value of this option only matters if the experimental trust mechanism
- has been activated. (See trustfile above.)
-
- If you use the trust mechanism, it is a good idea to write up some on-line
- documentation about your trust policy and to specify the URL(s) here. Use
- multiple times for multiple URLs.
-
- The URL(s) should be added to the trustfile as well, so users don't end up
- locked out from the information on why they were locked out in the first
- place!
-
--------------------------------------------------------------------------------
-
-7.2.3. admin-address
-
-Specifies:
-
- An email address to reach the proxy administrator.
-
-Type of value:
-
- Email address
-
-Default value:
-
- Unset
-
-Effect if unset:
-
- No email address is displayed on error pages and the CGI user interface.
-
-Notes:
-
- If both admin-address and proxy-info-url are unset, the whole "Local
- Privoxy Support" box on all generated pages will not be shown.
-
--------------------------------------------------------------------------------
-
-7.2.4. proxy-info-url
-
-Specifies:
-
- A URL to documentation about the local Privoxy setup, configuration or
- policies.
-
-Type of value:
-
- URL
-
-Default value:
-
- Unset
-
-Effect if unset:
-
- No link to local documentation is displayed on error pages and the CGI user
- interface.
-
-Notes:
-
- If both admin-address and proxy-info-url are unset, the whole "Local
- Privoxy Support" box on all generated pages will not be shown.
-
- This URL shouldn't be blocked ;-)
-
--------------------------------------------------------------------------------
-
-7.3. Debugging
-
-These options are mainly useful when tracing a problem. Note that you might
-also want to invoke Privoxy with the --no-daemon command line option when
-debugging.
-
--------------------------------------------------------------------------------
-
-7.3.1. debug
-
-Specifies:
-
- Key values that determine what information gets logged.
-
-Type of value:
-
- Integer values
-
-Default value:
-
- 12289 (i.e.: URLs plus informational and warning messages)
-
-Effect if unset:
-
- Nothing gets logged.
-
-Notes:
-
- The available debug levels are:
-
- debug 1 # show each GET/POST/CONNECT request
- debug 2 # show each connection status
- debug 4 # show I/O status
- debug 8 # show header parsing
- debug 16 # log all data into the logfile
- debug 32 # debug force feature
- debug 64 # debug regular expression filter
- debug 128 # debug fast redirects
- debug 256 # debug GIF de-animation
- debug 512 # Common Log Format
- debug 1024 # debug kill pop-ups
- debug 4096 # Startup banner and warnings.
- debug 8192 # Non-fatal errors
-
- To select multiple debug levels, you can either add them or use multiple
- debug lines.
-
- A debug level of 1 is informative because it will show you each request as
- it happens. 1, 4096 and 8192 are highly recommended so that you will notice
- when things go wrong. The other levels are probably only of interest if you
- are hunting down a specific problem. They can produce a hell of an output
- (especially 16).
-
- The reporting of fatal errors (i.e. ones which crash Privoxy) is always on
- and cannot be disabled.
-
- If you want to use CLF (Common Log Format), you should set "debug 512" ONLY
- and not enable anything else.
-
--------------------------------------------------------------------------------
-
-7.3.2. single-threaded
-
-Specifies:
-
- Whether to run only one server thread
-
-Type of value:
-
- None
-
-Default value:
-
- Unset
-
-Effect if unset:
-
- Multi-threaded (or, where unavailable: forked) operation, i.e. the ability
- to serve multiple requests simultaneously.
-
-Notes:
-
- This option is only there for debug purposes and you should never need to
- use it. It will drastically reduce performance.
-
--------------------------------------------------------------------------------
-
-7.4. Access Control and Security
-
-This section of the config file controls the security-relevant aspects of
-Privoxy's configuration.
-
--------------------------------------------------------------------------------
-
-7.4.1. listen-address
-
-Specifies:
-
- The IP address and TCP port on which Privoxy will listen for client
- requests.
-
-Type of value:
-
- [IP-Address]:Port
-
-Default value:
-
- localhost:8118
-
-Effect if unset:
-
- Bind to localhost (127.0.0.1), port 8118. This is suitable and recommended
- for home users who run Privoxy on the same machine as their browser.
-
-Notes:
-
- You will need to configure your browser(s) to this proxy address and port.
-
- 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.
-
- If you leave out the IP address, Privoxy 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 "ACLs" below),
- or a firewall.
-
-Example:
-
- Suppose you are running Privoxy 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:
-
- listen-address 192.168.0.1:8118
-
--------------------------------------------------------------------------------
-
-7.4.2. toggle
-
-Specifies:
-
- Initial state of "toggle" status
-
-Type of value:
-
- 1 or 0
-
-Default value:
-
- 1
-
-Effect if unset:
-
- Act as if toggled on
-
-Notes:
-
- If set to 0, Privoxy will start in "toggled off" mode, i.e. behave like a
- normal, content-neutral proxy. See enable-remote-toggle below. This is not
- really useful anymore, since toggling is much easier via the web interface
- than via editing the conf file.
-
- The windows version will only display the toggle icon in the system tray if
- this option is present.
-
--------------------------------------------------------------------------------
-
-7.4.3. enable-remote-toggle
-
-Specifies:
-
- Whether or not the web-based toggle feature may be used
-
-Type of value:
-
- 0 or 1
-
-Default value:
-
- 1
-
-Effect if unset:
-
- The web-based toggle feature is disabled.
-
-Notes:
-
- When toggled off, Privoxy acts like a normal, content-neutral proxy, i.e.
- it acts as if none of the actions applied to any URL.
-
- For the time being, access to the toggle feature can not be controlled
- separately by "ACLs" or HTTP authentication, so that everybody who can
- access Privoxy (see "ACLs" and listen-address above) can toggle it for all
- users. So this option is not recommended for multi-user environments with
- untrusted users.
-
- Note that you must have compiled Privoxy with support for this feature,
- otherwise this option has no effect.
-
--------------------------------------------------------------------------------
-
-7.4.4. enable-edit-actions
-
-Specifies:
-
- Whether or not the web-based actions file editor may be used
-
-Type of value:
-
- 0 or 1
-
-Default value:
-
- 1
-
-Effect if unset:
-
- The web-based actions file editor is disabled.
-
-Notes:
-
- For the time being, access to the editor can not be controlled separately
- by "ACLs" or HTTP authentication, so that everybody who can access Privoxy
- (see "ACLs" and listen-address above) can modify its configuration for all
- users. So this option is not recommended for multi-user environments with
- untrusted users.
-
- Note that you must have compiled Privoxy with support for this feature,
- otherwise this option has no effect.
-
--------------------------------------------------------------------------------
-
-7.4.5. ACLs: permit-access and deny-access
-
-Specifies:
-
- Who can access what.
-
-Type of value:
-
- src_addr[/src_masklen] [dst_addr[/dst_masklen]]
-
- Where src_addr and dst_addr are IP addresses in dotted decimal notation or
- valid DNS names, and src_masklen and dst_masklen are subnet masks in CIDR
- notation, i.e. integer values from 2 to 30 representing the length (in
- bits) of the network address. The masks and the whole destination part are
- optional.
-
-Default value:
-
- Unset
-
-Effect if unset:
-
- Don't restrict access further than implied by listen-address
-
-Notes:
-
- Access controls are included at the request of ISPs and systems
- administrators, and are not usually needed by individual users. For a
- typical home user, it will normally suffice to ensure that Privoxy only
- listens on the localhost or internal (home) network address by means of the
- listen-address option.
-
- Please see the warnings in the FAQ that this proxy is not intended to be a
- substitute for a firewall or to encourage anyone to defer addressing basic
- security weaknesses.
-
- Multiple ACL lines are OK. If any ACLs are specified, then the Privoxy
- talks only to IP addresses that match at least one permit-access line and
- don't match any subsequent deny-access line. In other words, the last match
- wins, with the default being deny-access.
-
- If Privoxy is using a forwarder (see forward below) for a particular
- destination URL, the dst_addr that is examined is the address of the
- forwarder and NOT the address of the ultimate target. This is necessary
- because it may be impossible for the local Privoxy to determine the IP
- address of the ultimate target (that's often what gateways are used for).
-
- You should prefer using IP addresses over DNS names, because the address
- lookups take time. All DNS names must resolve! You can not use domain
- patterns like "*.org" or partial domain names. If a DNS name resolves to
- multiple IP addresses, only the first one is used.
-
- Denying access to particular sites by ACL may have undesired side effects
- if the site in question is hosted on a machine which also hosts other
- sites.
-
-Examples:
-
- Explicitly define the default behavior if no ACL and listen-address are
- set: "localhost" is OK. The absence of a dst_addr implies that all
- destination addresses are OK:
-
- permit-access localhost
-
- Allow any host on the same class C subnet as www.privoxy.org access to
- nothing but www.example.com:
-
- permit-access www.privoxy.org/24 www.example.com/32
-
- Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere,
- with the exception that 192.168.45.73 may not access
- www.dirty-stuff.example.com:
-
- permit-access 192.168.45.64/26
- deny-access 192.168.45.73 www.dirty-stuff.example.com
-
--------------------------------------------------------------------------------
-
-7.4.6. buffer-limit
-
-Specifies:
-
- Maximum size of the buffer for content filtering.
-
-Type of value:
-
- Size in Kbytes
-
-Default value:
-
- 4096
-
-Effect if unset:
-
- Use a 4MB (4096 KB) limit.
-
-Notes:
-
- For content filtering, i.e. the +filter and +deanimate-gif actions, it is
- necessary that Privoxy buffers the entire document body. This can be
- potentially dangerous, since a server could just keep sending data
- indefinitely and wait for your RAM to exhaust -- with nasty consequences.
- Hence this option.
-
- When a document buffer size reaches the buffer-limit, it is flushed to the
- client unfiltered and no further attempt to filter the rest of the document
- is made. Remember that there may be multiple threads running, which might
- require up to buffer-limit Kbytes each, unless you have enabled
- "single-threaded" above.
-
--------------------------------------------------------------------------------
-
-7.5. Forwarding
-
-This feature allows routing of HTTP requests through a chain of multiple
-proxies. It can be used to better protect privacy and confidentiality when
-accessing specific domains by routing requests to those domains through an
-anonymous public proxy (see e.g. http://www.multiproxy.org/anon_list.htm) Or to
-use a caching proxy to speed up browsing. Or chaining to a parent proxy may be
-necessary because the machine that Privoxy runs on has no direct Internet
-access.
-
-Also specified here are SOCKS proxies. Privoxy supports the SOCKS 4 and SOCKS
-4A protocols.
-
--------------------------------------------------------------------------------
-
-7.5.1. forward
-
-Specifies:
-
- To which parent HTTP proxy specific requests should be routed.
-
-Type of value:
-
- target_domain[:port] http_parent[/port]
-
- Where target_domain is a domain name pattern (see the chapter on domain
- matching in the default.action file), http_parent is the address of the
- parent HTTP proxy as an IP addresses in dotted decimal notation or as a
- valid DNS name (or "." to denote "no forwarding", and the optional port
- parameters are TCP ports, i.e. integer values from 1 to 64535
-
-Default value:
-
- Unset
-
-Effect if unset:
-
- Don't use parent HTTP proxies.
-
-Notes:
-
- If http_parent is ".", then requests are not forwarded to another HTTP
- proxy but are made directly to the web servers.
-
- Multiple lines are OK, they are checked in sequence, and the last match
- wins.
-
-Examples:
-
- Everything goes to an example anonymizing proxy, except SSL on port 443
- (which it doesn't handle):
-
- forward .* anon-proxy.example.org:8080
- forward :443 .
-
- Everything goes to our example ISP's caching proxy, except for requests to
- that ISP's sites:
-
- forward .*. caching-proxy.example-isp.net:8000
- forward .example-isp.net .
-
--------------------------------------------------------------------------------
-
-7.5.2. forward-socks4 and forward-socks4a
-
-Specifies:
-
- Through which SOCKS proxy (and to which parent HTTP proxy) specific
- requests should be routed.
-
-Type of value:
-
- target_domain[:port] socks_proxy[/port] http_parent[/port]
-
- Where target_domain is a domain name pattern (see the chapter on domain
- matching in the default.action file), http_parent and socks_proxy are IP
- addresses in dotted decimal notation or valid DNS names (http_parent may be
- "." to denote "no HTTP forwarding"), and the optional port parameters are
- TCP ports, i.e. integer values from 1 to 64535
-
-Default value:
-
- Unset
-
-Effect if unset:
-
- Don't use SOCKS proxies.
-
-Notes:
-
- Multiple lines are OK, they are checked in sequence, and the last match
- wins.
-
- The difference between forward-socks4 and forward-socks4a is that in the
- SOCKS 4A protocol, the DNS resolution of the target hostname happens on the
- SOCKS server, while in SOCKS 4 it happens locally.
-
- If http_parent is ".", then requests are not forwarded to another HTTP
- proxy but are made (HTTP-wise) directly to the web servers, albeit through
- a SOCKS proxy.
-
-Examples:
-
- From the company example.com, direct connections are made to all "internal"
- domains, but everything outbound goes through their ISP's proxy by way of
- example.com's corporate SOCKS 4A gateway to the Internet.
-
- forward-socks4a .*. socks-gw.example.com:1080 www-cache.example-isp.net:8080
- forward .example.com .
-
- A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent
- looks like this:
-
- forward-socks4 .*. socks-gw.example.com:1080 .
-
--------------------------------------------------------------------------------
-
-7.5.3. Advanced Forwarding Examples
-
-If you have links to multiple ISPs that provide various special content only to
-their subscribers, you can configure multiple Privoxies which have connections
-to the respective ISPs to act as forwarders to each other, so that your users
-can see the internal content of all ISPs.
-
-Assume that host-a has a PPP connection to isp-a.net. And host-b has a PPP
-connection to isp-b.net. Both run Privoxy. Their forwarding configuration can
-look like this:
-
-host-a:
-
- forward .*. .
- forward .isp-b.net host-b:8118
-
-host-b:
-
- forward .*. .
- forward .isp-a.net host-a:8118
-
-Now, your users can set their browser's proxy to use either host-a or host-b
-and be able to browse the internal content of both isp-a and isp-b.
-
-If you intend to chain Privoxy and squid locally, then chain as browser ->
-squid -> privoxy is the recommended way.
-
-Assuming that Privoxy and squid run on the same box, your squid configuration
-could then look like this:
-
- # Define Privoxy as parent proxy (without ICP)
- cache_peer 127.0.0.1 parent 8118 7 no-query
-
- # Define ACL for protocol FTP
- acl ftp proto FTP
-
- # Do not forward FTP requests to Privoxy
- always_direct allow ftp
-
- # Forward all the rest to Privoxy
- never_direct allow all
-
-You would then need to change your browser's proxy settings to squid's address
-and port. Squid normally uses port 3128. If unsure consult http_port in
-squid.conf.
-
--------------------------------------------------------------------------------
-
-7.6. Windows GUI Options
-
-Privoxy has a number of options specific to the Windows GUI interface:
-
-If "activity-animation" is set to 1, the Privoxy icon will animate when
-"Privoxy" is active. To turn off, set to 0.
-
- activity-animation 1
-
-
-If "log-messages" is set to 1, Privoxy will log messages to the console window:
-
- log-messages 1
-
+ Type:
-If "log-buffer-size" 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 "log-max-lines" (see below).
+ Parameterized.
-Warning: Setting this to 0 will result in the buffer to grow infinitely and eat
-up all your memory!
+ Parameter:
- log-buffer-size 1
-
+ The name of a server-header tagger, as defined in one of the
+ filter files.
-log-max-lines is the maximum number of lines held in the log buffer. See above.
+ Notes:
- log-max-lines 200
-
+ Server-header taggers are applied to each header on its own, and
+ as the header isn't modified, each tagger "sees" the original.
-If "log-highlight-messages" is set to 1, Privoxy will highlight portions of the
-log messages with a bold-faced font:
+ Server-header taggers are executed before all other header actions
+ that modify server headers. Their tags can be used to control all
+ of the other server-header actions, the content filters and the
+ crunch actions (redirect and block).
- log-highlight-messages 1
-
+ Obviously crunching based on tags created by server-header taggers
+ doesn't prevent the request from showing up in the server's log
+ file.
-The font used in the console window:
+ Example usage (section):
- log-font-name Comic Sans MS
-
+ # Tag every request with the content type declared by the server
+ {+server-header-tagger{content-type}}
+ /
-Font size used in the console window:
- log-font-size 8
-
+ --------------------------------------------------------------------------
-"show-on-task-bar" controls whether or not Privoxy will appear as a button on
-the Task bar when minimized:
+ 8.5.36. session-cookies-only
- show-on-task-bar 0
-
+ Typical use:
-If "close-button-minimizes" is set to 1, the Windows close button will minimize
-Privoxy instead of closing the program (close with the exit option on the File
-menu).
+ Allow only temporary "session" cookies (for the current browser
+ session only).
- close-button-minimizes 1
-
+ Effect:
-The "hide-console" option is specific to the MS-Win console version of Privoxy.
-If this option is used, Privoxy will disconnect from and hide the command
-console.
+ Deletes the "expires" field from "Set-Cookie:" server headers.
+ Most browsers will not store such cookies permanently and forget
+ them in between sessions.
- #hide-console
-
+ Type:
--------------------------------------------------------------------------------
+ Boolean.
-8. Actions Files
+ Parameter:
-The actions files are used to define what actions Privoxy takes for which URLs,
-and thus determine how ad images, cookies and various other aspects of HTTP
-content and transactions are handled, and on which sites (or even parts
-thereof). There are three such files included with Privoxy (as of version
-2.9.15), with differing purposes:
-
- * standard.action - is used by the web based editor, to set various
- pre-defined sets of rules for the default actions section in
- default.action. These have increasing levels of aggressiveness and have no
- influence on your browsing unless you select them explicitly in the editor.
- It is not recommend to edit this file.
-
- * default.action - is the primary action file that sets the initial values
- for all actions. It is intended to provide a base level of functionality
- for Privoxy's array of features. So it is a set of broad rules that should
- work reasonably well for users everywhere. This is the file that the
- developers are keeping updated, and making available to users.
-
- * user.action - is intended to be for local site preferences and exceptions.
- As an example, if your ISP or your bank has specific requirements, and need
- special handling, this kind of thing should go here. This file will not be
- upgraded.
-
-The list of actions files to be used are defined in the main configuration
-file, and are processed in the order they are defined. The content of these can
-all be viewed and edited from http://config.privoxy.org/show-status.
-
-An actions file typically has multiple sections. If you want to use "aliases"
-in an actions file, you have to place the (optional) alias section at the top
-of that file. Then comes the default set of rules which will apply universally
-to all sites and pages (be very careful with using such a universal set in
-user.action or any other actions file after default.action, because it will
-override the result from consulting any previous file). And then below that,
-exceptions to the defined universal policies. You can regard user.action as an
-appendix to default.action, with the advantage that is a separate file, which
-makes preserving your personal settings across Privoxy upgrades easier.
-
-Actions can be used to block anything you want, including ads, banners, or just
-some obnoxious URL that you would rather not see. Cookies can be accepted or
-rejected, or accepted only during the current browser session (i.e. not written
-to disk), content can be modified, JavaScripts tamed, user-tracking fooled, and
-much more. See below for a complete list of actions.
-
--------------------------------------------------------------------------------
-
-8.1. Finding the Right Mix
-
-Note that some actions, like cookie suppression or script disabling, may render
-some sites unusable that rely on these techniques to work properly. Finding the
-right mix of actions is not always easy and certainly a matter of personal
-taste. In general, it can be said that the more "aggressive" your default
-settings (in the top section of the actions file) are, the more exceptions for
-"trusted" sites you will have to make later. If, for example, you want to kill
-popup windows per default, you'll have to make exceptions from that rule for
-sites that you regularly use and that require popups for actually useful
-content, like maybe your bank, favorite shop, or newspaper.
-
-We have tried to provide you with reasonable rules to start from in the
-distribution actions files. But there is no general rule of thumb on these
-things. There just are too many variables, and sites are constantly changing.
-Sooner or later you will want to change the rules (and read this chapter again
-:).
-
--------------------------------------------------------------------------------
-
-8.2. How to Edit
-
-The easiest way to edit the actions files is with a browser by using our
-browser-based editor, which can be reached from http://config.privoxy.org/
-show-status. The editor allows both fine-grained control over every single
-feature on a per-URL basis, and easy choosing from wholesale sets of defaults
-like "Cautious", "Medium" or "Advanced".
-
-If you prefer plain text editing to GUIs, you can of course also directly edit
-the the actions files. Look at default.action which is richly commented.
-
--------------------------------------------------------------------------------
-
-8.3. How Actions are Applied to URLs
-
-Actions files are divided into sections. There are special sections, like the "
-alias" sections which will be discussed later. For now let's concentrate on
-regular sections: They have a heading line (often split up to multiple lines
-for readability) which consist of a list of actions, separated by whitespace
-and enclosed in curly braces. Below that, there is a list of URL patterns, each
-on a separate line.
-
-To determine which actions apply to a request, the URL of the request is
-compared to all patterns in each action file file. Every time it matches, the
-list of applicable actions for the URL is incrementally updated, using the
-heading of the section in which the pattern is located. If multiple matches for
-the same URL set the same action differently, the last match wins. If not, the
-effects are aggregated (e.g. a URL might match both the "+handle-as-image" and
-"+block" actions).
-
-You can trace this process for any given URL by visiting http://
-config.privoxy.org/show-url-info.
-
-More detail on this is provided in the Appendix, Anatomy of an Action.
-
--------------------------------------------------------------------------------
-
-8.4. Patterns
-
-Generally, a pattern has the form <domain>/<path>, where both the <domain> and
-<path> are optional. (This is why the pattern / matches all URLs).
-
-www.example.com/
-
- is a domain-only pattern and will match any request to www.example.com,
- regardless of which document on that server is requested.
-
-www.example.com
-
- means exactly the same. For domain-only patterns, the trailing / may be
- omitted.
-
-www.example.com/index.html
-
- matches only the single document /index.html on www.example.com.
-
-/index.html
-
- matches the document /index.html, regardless of the domain, i.e. on any web
- server.
-
-index.html
-
- matches nothing, since it would be interpreted as a domain name and there
- is no top-level domain called .html.
-
--------------------------------------------------------------------------------
-
-8.4.1. The Domain Pattern
-
-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:
-
-.example.com
-
- matches any domain that ENDS in .example.com
-
-www.
-
- matches any domain that STARTS with www.
-
-.example.
-
- matches any domain that CONTAINS .example. (Correctly speaking: It matches
- any FQDN that contains example as a domain.)
-
-Additionally, there are wild-cards that you can use in the domain names
-themselves. They work pretty similar to shell wild-cards: "*" stands for zero
-or more arbitrary characters, "?" stands for any single character, you can
-define character classes in square brackets and all of that can be freely
-mixed:
-
-ad*.example.com
-
- matches "adserver.example.com", "ads.example.com", etc but not
- "sfads.example.com"
-
-*ad*.example.com
-
- matches all of the above, and then some.
-
-.?pix.com
-
- matches www.ipix.com, pictures.epix.com, a.b.c.d.e.upix.com etc.
-
-www[1-9a-ez].example.c*
-
- matches www1.example.com, www4.example.cc, wwwd.example.cy,
- wwwz.example.com etc., but not wwww.example.com.
-
--------------------------------------------------------------------------------
-
-8.4.2. The Path Pattern
-
-Privoxy uses Perl compatible regular expressions (through the PCRE library) for
-matching the path.
-
-There is an Appendix with a brief quick-start into regular expressions, and
-full (very technical) documentation on PCRE regex syntax is available on-line
-at http://www.pcre.org/man.txt. You might also find the Perl man page on
-regular expressions (man perlre) useful, which is available on-line at http://
-www.perldoc.com/perl5.6/pod/perlre.html.
-
-Note that the path pattern is automatically left-anchored at the "/", i.e. it
-matches as if it would start with a "^" (regular expression speak for the
-beginning of a line).
-
-Please also note that matching in the path is case INSENSITIVE by default, but
-you can switch to case sensitive at any point in the pattern by using the "(?
--i)" switch: www.example.com/(?-i)PaTtErN.* will match only documents whose
-path starts with PaTtErN in exactly this capitalization.
-
--------------------------------------------------------------------------------
-
-8.5. Actions
-
-All actions are disabled by default, until they are explicitly enabled
-somewhere in an actions file. Actions are turned on if preceded with a "+", and
-turned off if preceded with a "-". So a +action means "do that action", e.g.
-+block means "please block URLs that match the following patterns", and -block
-means "don't block URLs that match the following patterns, even if +block
-previously applied."
-
-Again, actions are invoked by placing them on a line, enclosed in curly braces
-and separated by whitespace, like in {+some-action -some-other-action
-{some-parameter}}, followed by a list of URL patterns, one per line, to which
-they apply. Together, the actions line and the following pattern lines make up
-a section of the actions file.
-
-There are three classes of actions:
-
- * Boolean, i.e the action can only be "enabled" or "disabled". Syntax:
-
- +name # enable action name
- -name # disable action name
-
- Example: +block
-
- * Parameterized, where some value is required in order to enable this type of
- action. Syntax:
-
- +name{param} # enable action and set parameter to param,
- # overwriting parameter from previous match if necessary
- -name # disable action. The parameter can be omitted
-
- Note that if the URL matches multiple positive forms of a parameterized
- action, the last match wins, i.e. the params from earlier matches are
- simply ignored.
-
- Example: +hide-user-agent{ Mozilla 1.0 }
-
- * Multi-value. These look exactly like parameterized actions, but they behave
- differently: If the action applies multiple times to the same URL, but with
- different parameters, all the parameters from all matches are remembered.
- This is used for actions that can be executed for the same request
- repeatedly, like adding multiple headers, or filtering through multiple
- filters. Syntax:
-
- +name{param} # enable action and add param to the list of parameters
- -name{param} # remove the parameter param from the list of parameters
- # If it was the last one left, disable the action.
- -name # disable this action completely and remove all parameters from the list
-
- Examples: +add-header{X-Fun-Header: Some text} and +filter{html-annoyances}
-
-If nothing is specified in any actions file, no "actions" are taken. So in this
-case Privoxy 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 actions files will give a good starting point).
-
-Later defined actions always over-ride earlier ones. So exceptions to any rules
-you make, should come in the latter part of the file (or in a file that is
-processed later when using multiple actions files). For multi-valued actions,
-the actions are applied in the order they are specified. Actions files are
-processed in the order they are defined in config (the default installation has
-three actions files). It also quite possible for any given URL pattern to match
-more than one pattern and thus more than one set of actions!
-
-The list of valid Privoxy actions are:
-
--------------------------------------------------------------------------------
-
-8.5.1. +add-header
-
-Type:
-
- Multi-value.
-
-Purpose and typical uses:
-
- Send a user defined HTTP header to the web server. Can be used to confuse
- log analysis.
-
-Possible values:
-
- Any value is possible. Validity of the defined HTTP headers is not checked.
- It is recommended that you use the "X-" prefix for custom headers.
-
-Example usage:
-
- {+add-header{X-User-Tracking: sucks}}
- .example.com
-
-Notes:
-
- This action may be specified multiple times, in order to define multiple
- headers. This is rarely needed for the typical user. If you don't know what
- "HTTP headers" are, you definitely don't need to worry about this one.
-
--------------------------------------------------------------------------------
-
-8.5.2. +block
-
-Type:
-
- Boolean.
-
-Purpose and typical uses:
-
- Requests for URLs to which this action applies are blocked, i.e. the
- requests are not forwarded to the remote server, but answered locally with
- a substitute page or image, as determined by the handle-as-image and
- set-image-blocker actions. It is typically used to block ads or other
- obnoxious content.
-
-Possible values:
-
- N/A
-
-Example usage:
-
- {+block}
- .banners.example.com
- .ads.r.us
-
-
-Notes:
-
- If a URL matches one of the blocked patterns, Privoxy will intercept the
- URL and display its special "BLOCKED" page instead. If there is sufficient
- space, a large red banner will appear with a friendly message about why the
- page was blocked, and a way to go there anyway. If there is insufficient
- space a smaller "BLOCKED" page will appear without the red banner. Click
- here to view the default blocked HTML page (Privoxy must be running for
- this to work as intended!).
-
- A very important exception is if the URL matches both "+block" and
- "+handle-as-image", then it will be handled by "+set-image-blocker" (see
- below). It is important to understand this process, in order to understand
- how Privoxy is able to deal with ads and other objectionable content.
-
- The "+filter" action can also perform some of the same functionality as
- "+block", but by virtue of very different programming techniques, and is
- most often used for different reasons.
-
--------------------------------------------------------------------------------
-
-8.5.3. +deanimate-gifs
-
-Type:
-
- Parameterized.
-
-Typical uses:
-
- To stop those annoying, distracting animated GIF images.
-
-Possible values:
-
- "last" or "first"
-
-Example usage:
-
- {+deanimate-gifs{last}}
- .example.com
-
-
-Notes:
-
- 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 "first" is given, the first frame of the animation is used as
- the replacement. If "last" 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).
-
--------------------------------------------------------------------------------
-
-8.5.4. +downgrade-http-version
-
-Type:
-
- Boolean.
-
-Typical uses:
-
- "+downgrade-http-version" will downgrade HTTP/1.1 client requests to HTTP/
- 1.0 and downgrade the responses as well.
-
-Possible values:
-
- N/A
-
-Example usage:
-
- {+downgrade-http-version}
- .example.com
-
-
-Notes:
-
- Use this action for servers that use HTTP/1.1 protocol features that
- Privoxy doesn't handle well yet. HTTP/1.1 is only partially implemented.
- Default is not to downgrade requests. This is an infrequently needed
- action, and is used to help with rare problem sites only.
-
--------------------------------------------------------------------------------
-
-8.5.5. +fast-redirects
-
-Type:
-
- Boolean.
-
-Typical uses:
-
- The "+fast-redirects" action enables interception of "redirect" requests
- from one server to another, which are used to track users.Privoxy can cut
- off all but the last valid URL in a redirect request and send a local
- redirect back to your browser without contacting the intermediate site(s).
-
-Possible values:
-
- N/A
-
-Example usage:
-
- {+fast-redirects}
- .example.com
-
-
-Notes:
-
- 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.
-
- 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.
-
- This is a normally "on" feature, and often requires exceptions for sites
- that are sensitive to defeating this mechanism.
-
--------------------------------------------------------------------------------
-
-8.5.6. +filter
-
-Type:
-
- Parameterized.
-
-Typical uses:
-
- Apply page filtering as defined by named sections of the default.filter
- file to the specified site(s). "Filtering" can be any modification of the
- raw page content, including re-writing or deletion of content.
-
-Possible values:
-
- "+filter" must include the name of one of the section identifiers from
- default.filter (or whatever filterfile is specified in config).
-
-Example usage (from the current default.filter):
-
- +filter{html-annoyances}: Get rid of particularly annoying HTML abuse.
-
- +filter{js-annoyances}: Get rid of particularly annoying JavaScript abuse
-
- +filter{content-cookies}: Kill cookies that come in the HTML or JS content
-
- +filter{popups}: Kill all popups in JS and HTML
-
- +filter{frameset-borders}: Give frames a border and make them resizable
-
- +filter{webbugs}: Squish WebBugs (1x1 invisible GIFs used for user
- tracking)
-
- +filter{refresh-tags}: Kill automatic refresh tags (for dial-on-demand
- setups)
-
- +filter{fun}: Text replacements for subversive browsing fun!
-
- +filter{nimda}: Remove Nimda (virus) code.
-
- +filter{banners-by-size}: Kill banners by size (very efficient!)
-
- +filter{shockwave-flash}: Kill embedded Shockwave Flash objects
-
- +filter{crude-parental}: Kill all web pages that contain the words "sex" or
- "warez"
-
-Notes:
-
- This is potentially a very powerful feature! And requires a knowledge of
- regular expressions if you want to "roll your own". Filtering operates on a
- line by line basis throughout the entire page.
-
- Filtering requires buffering the page content, which may appear to slow
- down page rendering since nothing is displayed until all content has passed
- the filters. (It does not really take longer, but seems that way since the
- page is not incrementally displayed.) This effect will be more noticeable
- on slower connections.
-
- Filtering can achieve some of the effects as the "+block" action, i.e. it
- can be used to block ads and banners. In the overall scheme of things,
- filtering is one of the first things "Privoxy" does with a web page. So
- other most other actions are applied to the already "filtered" page.
-
--------------------------------------------------------------------------------
-
-8.5.7. +hide-forwarded-for-headers
-
-Type:
-
- Boolean.
-
-Typical uses:
-
- Block any existing X-Forwarded-for HTTP header, and do not add a new one.
-
-Possible values:
-
- N/A
-
-Example usage:
-
- {+hide-forwarded-for-headers}
- .example.com
-
-
-Notes:
-
- It is fairly safe to leave this on. It does not seem to break many sites.
-
--------------------------------------------------------------------------------
-
-8.5.8. +hide-from-header
-
-Type:
-
- Parameterized.
-
-Typical uses:
-
- To block the browser from sending your email address in a "From:" header.
-
-Possible values:
-
- Keyword: "block", or any user defined value.
-
-Example usage:
-
- {+hide-from-header{block}}
- .example.com
-
-
-Notes:
-
- The keyword "block" will completely remove the header (not to be confused
- with the "+block" action). Alternately, you can specify any value you
- prefer to send to the web server.
-
--------------------------------------------------------------------------------
-
-8.5.9. +hide-referer
-
-Type:
-
- Parameterized.
-
-Typical uses:
-
- Don't send the "Referer:" (sic) HTTP header to the web site. Or,
- alternately send a forged header instead.
-
-Possible values:
-
- Prevent the header from being sent with the keyword, "block". Or, "forge" a
- URL to one from the same server as the request. Or, set to user defined
- value of your choice.
-
-Example usage:
-
- {+hide-referer{forge}}
- .example.com
-
-
-Notes:
-
- "forge" is the preferred option here, since some servers will not send
- images back otherwise.
-
- "+hide-referrer" is an alternate spelling of "+hide-referer". It has the
- exact same parameters, and can be freely mixed with, "+hide-referer".
- ("referrer" is the correct English spelling, however the HTTP specification
- has a bug - it requires it to be spelled as "referer".)
-
--------------------------------------------------------------------------------
-
-8.5.10. +hide-user-agent
-
-Type:
-
- Parameterized.
-
-Typical uses:
-
- To change the "User-Agent:" header so web servers can't tell your browser
- type. Who's business is it anyway?
-
-Possible values:
-
- Any user defined string.
-
-Example usage:
-
- {+hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}}
- .msn.com
-
-
-Notes:
-
- Warning! This breaks many web sites that depend on this in order to
- determine how the target browser will respond to various requests. Use with
- caution.
-
--------------------------------------------------------------------------------
-
-8.5.11. +handle-as-image
-
-Type:
-
- Boolean.
-
-Typical uses:
-
- To define what Privoxy should treat automatically as an image, and is an
- important ingredient of how ads are handled.
-
-Possible values:
-
- N/A
-
-Example usage:
-
- {+handle-as-image}
- /.*\.(gif|jpg|jpeg|png|bmp|ico)
-
-
-Notes:
-
- This only has meaning if the URL (or pattern) also is "+block"ed, in which
- case a user definable image can be sent rather than a HTML page. This is
- integral to the whole concept of ad blocking: the URL must match both a
- "+block" rule, and "+handle-as-image". (See "+set-image-blocker" below for
- control over what will actually be displayed by the browser.)
-
- There is little reason to change the default definition for this action.
-
--------------------------------------------------------------------------------
-
-8.5.12. +set-image-blocker
-
-Type:
-
- Parameterized.
-
-Typical uses:
-
- Decide what to do with URLs that end up tagged with both "+block" and
- "+handle-as-image", e.g an advertisement.
-
-Possible values:
-
- There are four available options: "-set-image-blocker" will send a HTML
- "blocked" page, usually resulting in a "broken image" icon.
- "+set-image-blocker{blank}" will send a 1x1 transparent GIF image.
- "+set-image-blocker{pattern}" will send a checkerboard type pattern (the
- default). And finally, "+set-image-blocker{http://xyz.com}" 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.
-
-Example usage:
-
- {+set-image-blocker{blank}}
- .example.com
-
-
-Notes:
-
- If you want invisible ads, they need to meet criteria as matching both
- images and blocked actions. And then, "image-blocker" should be set to
- "blank" for invisibility. Note you cannot treat HTML pages as images in
- most cases. For instance, frames require an HTML page to display. So a
- frame that is an ad, typically cannot be treated as an image. Forcing an
- "image" in this situation just will not work reliably.
-
--------------------------------------------------------------------------------
-
-8.5.13. +limit-connect
-
-Type:
-
- Parameterized.
-
-Typical uses:
-
- By default, Privoxy only allows HTTP CONNECT requests to port 443 (the
- standard, secure HTTPS port). Use "+limit-connect" to disable this
- altogether, or to allow more ports.
-
-Possible values:
-
- Any valid port number, or port number range.
-
-Example usages:
-
- +limit-connect{443} #
- This is the default and need not be specified.
- +limit-connect{80,443} # Ports 80 and 443 are OK.
- +limit-connect{-3, 7, 20-100, 500-} #
- Port less than 3, 7, 20 to 100 and above 500 are OK.
-
-
-Notes:
-
- 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 and to the remote proxy. This can be a big
- security hole, since CONNECT-enabled proxies can be abused as TCP relays
- very easily.
-
- 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).
-
- If you don't know what any of this means, there probably is no reason to
- change this one.
-
--------------------------------------------------------------------------------
-
-8.5.14. +prevent-compression
-
-Type:
-
- Boolean.
-
-Typical uses:
-
- Prevent the specified websites from compressing HTTP data.
-
-Possible values:
-
- N/A
-
-Example usage:
-
- {+prevent-compression}
- .example.com
-
-
-Notes:
-
- Some websites do this, which can be a problem for Privoxy, since "+filter",
- "+kill-popups" and "+gif-deanimate" will not work on compressed data. This
- will slow down connections to those websites, though. Default typically is
- to turn "prevent-compression" on.
-
--------------------------------------------------------------------------------
-
-8.5.15. +session-cookies-only
-
-Type:
-
- Boolean.
-
-Typical uses:
-
- Allow cookies for the current browser session only.
-
-Possible values:
-
- N/A
-
-Example usage (disabling):
-
- {-session-cookies-only}
- .example.com
-
-
-Notes:
-
- If websites set cookies, "+session-cookies-only" 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. This is generally turned on for all sites, and
- is the recommended setting.
-
- "+prevent-*-cookies" actions should be turned off as well (see below), for
- "+session-cookies-only" to work. Or, else no cookies will get through at
- all. For, "persistent" cookies that survive across browser sessions, see
- below as well.
-
--------------------------------------------------------------------------------
-
-8.5.16. +prevent-reading-cookies
-
-Type:
-
- Boolean.
-
-Typical uses:
-
- Explicitly prevent the web server from reading any cookies on your system.
-
-Possible values:
-
- N/A
-
-Example usage:
-
- {+prevent-reading-cookies}
- .example.com
-
-
-Notes:
-
- Often used in conjunction with "+prevent-setting-cookies" to disable
- cookies completely. Note that "+session-cookies-only" requires these to
- both be disabled (or else it never gets any cookies to cache).
-
- For "persistent" cookies to work (i.e. they survive across browser sessions
- and reboots), all three cookie settings should be "off" for the specified
- sites.
-
--------------------------------------------------------------------------------
-
-8.5.17. +prevent-setting-cookies
-
-Type:
-
- Boolean.
-
-Typical uses:
-
- Explicitly block the web server from storing cookies on your system.
-
-Possible values:
-
- N/A
-
-Example usage:
-
- {+prevent-setting-cookies}
- .example.com
-
-
-Notes:
-
- Often used in conjunction with "+prevent-reading-cookies" to disable
- cookies completely (see above).
-
--------------------------------------------------------------------------------
-
-8.5.18. +kill-popups
-
-Type:
-
- Boolean.
-
-Typical uses:
-
- Stop those annoying JavaScript pop-up windows!
-
-Possible values:
-
- N/A
-
-Example usage:
-
- {+kill-popups}
- .example.com
-
-
-Notes:
-
- "+kill-popups" uses a built in filter to disable pop-ups that use the
- window.open() function, etc. This is one of the first actions processed by
- Privoxy as it contacts the remote web server. This action is not always
- 100% reliable, and is supplemented by "+filter{popups}".
-
--------------------------------------------------------------------------------
-
-8.5.19. +send-vanilla-wafer
-
-Type:
-
- Boolean.
-
-Typical uses:
-
- Sends a cookie for every site stating that you do not accept any copyright
- on cookies sent to you, and asking them not to track you.
-
-Possible values:
-
- N/A
-
-Example usage:
-
- {+send-vanilla-wafer}
- .example.com
-
-
-Notes:
-
- This action only applies if you are using a jarfile for saving cookies. Of
- course, this is a (relatively) unique header and could conceivably be used
- to track you.
-
--------------------------------------------------------------------------------
-
-8.5.20. +send-wafer
-
-Type:
-
- Multi-value.
-
-Typical uses:
-
- This allows you to send an arbitrary, user definable cookie.
-
-Possible values:
-
- User specified cookie name and corresponding value.
-
-Example usage:
-
- {+send-wafer{name=value}}
- .example.com
-
-
-Notes:
-
- This can be specified multiple times in order to add as many cookies as you
- like.
-
--------------------------------------------------------------------------------
-
-8.5.21. Summary
-
-Note that many of these actions have the potential to cause a page to
-misbehave, possibly even not to display at all. There are many ways a site
-designer may choose to design his site, and what HTTP header content, and other
-criteria, he may depend on. There is no way to have hard and fast rules for all
-sites. See the Appendix for a brief example on troubleshooting actions.
-
--------------------------------------------------------------------------------
-
-8.5.22. Sample Actions Files
-
-Remember that the meaning of any of the above references is reversed by
-preceding the action with a "-", in place of the "+". Also, that some actions
-are turned on in the default section of the actions file, and require little to
-no additional configuration. These are just "on".
-
-But, other actions that are turned on in the default section do typically
-require exceptions to be listed in the latter sections of one of our actions
-file. For instance, by default no URLs are "blocked" (i.e. in the default
-definitions of default.action). We need exceptions to this in order to enable
-ad blocking in the lower sections. But we need to be very selective about what
-we do block. Thus, the default is "off" for blocking.
-
-Below is a liberally commented sample default.action file to demonstrate how
-all the pieces come together. And to show how exceptions to the default
-policies can be handled. This is followed by a brief user.action with similar
-examples.
-
-# Sample default.action file <developers@privoxy.org>
-
-# Settings -- Don't change! For internal Privoxy use ONLY.
-{{settings}}
-for-privoxy-version=3.0
+ N/A
+ Notes:
-##########################################################################
-# Aliases must be defined *before* they are used. These are
-# easier to remember, and can combine several actions into one. Once
-# defined they can be used just like any built-in action -- but within
-# this file only! Aliases do not require a + or - sign.
-##########################################################################
+ This is less strict than crunch-incoming-cookies /
+ crunch-outgoing-cookies and allows you to browse websites that
+ insist or rely on setting cookies, without compromising your
+ privacy too badly.
-# Some useful aliases.
-# Alias to turn off cookie handling, ie allow all cookies unmolested.
- -prevent-cookies = -prevent-setting-cookies -prevent-reading-cookies \
- -session-cookies-only
+ Most browsers will not permanently store cookies that have been
+ processed by session-cookies-only and will forget about them
+ between sessions. This makes profiling cookies useless, but won't
+ break sites which require cookies so that you can log in for
+ transactions. This is generally turned on for all sites, and is
+ the recommended setting.
-# Alias to both block and treat as if an image for ad blocking
-# purposes.
- +imageblock = +block +handle-as-image
+ It makes no sense at all to use session-cookies-only together with
+ crunch-incoming-cookies or crunch-outgoing-cookies. If you do,
+ cookies will be plainly killed.
-# Fragile sites should have the minimum changes:
- fragile = -block -deanimate-gifs -fast-redirects -filter -hide-referer \
- -prevent-cookies -kill-popups
+ Note that it is up to the browser how it handles such cookies
+ without an "expires" field. If you use an exotic browser, you
+ might want to try it out to be sure.
-# Shops should be allowed to set persistent cookies
- shop = -filter -prevent-cookies -session-cookies-only
+ This setting also has no effect on cookies that may have been
+ stored previously by the browser before starting Privoxy. These
+ would have to be removed manually.
+ Privoxy also uses the content-cookies filter to block some types
+ of cookies. Content cookies are not effected by
+ session-cookies-only.
-##########################################################################
-# Begin default action settings. Anything in this section will match
-# all URLs -- UNLESS we have exceptions that also match, defined below this
-# section. We will show all potential actions here whether they are on
-# or off. We could omit any disabled action if we wanted, since all
-# actions are 'off' by default anyway. Shown for completeness only.
-# Actions are enabled if preceded by a '+', otherwise they are disabled
-# (unless an alias has been defined without this).
-##########################################################################
- { \
- -add-header \
- -block \
- -deanimate-gifs \
- -downgrade-http-version \
- +fast-redirects \
- +filter{html-annoyances} \
- +filter{js-annoyances} \
- -filter{content-cookies} \
- -filter{popups} \
- +filter{webbugs} \
- -filter{refresh-tags} \
- -filter{fun} \
- +filter{nimda} \
- +filter{banners-by-size} \
- -filter{shockwave-flash} \
- -filter{crude-prental} \
- +hide-forwarded-for-headers \
- +hide-from-header{block} \
- -hide-referrer \
- -hide-user-agent \
- -handle-as-image \
- +set-image-blocker{pattern} \
- -limit-connect \
- +prevent-compression \
- -session-cookies-only \
- -prevent-reading-cookies \
- -prevent-setting-cookies \
- -kill-popups \
- -send-vanilla-wafer \
- -send-wafer \
- }
- / # forward slash will match *all* potential URL patterns.
+ Example usage:
-##########################################################################
-# Default behavior is now set. Now we will define some exceptions to our
-# default action policies.
-##########################################################################
+ +session-cookies-only
-# These sites are very complex and require very minimal interference.
-# We'll disable most actions with our 'fragile' alias:
- { fragile }
- .office.microsoft.com # surprise, surprise!
- .windowsupdate.microsoft.com
-
-
-# Shopping sites - not as fragile but require some special
-# handling. We still want to block ads, and we will allow
-# persistant cookies via the 'shop' alias:
- { shop }
- .quietpc.com
- .worldpay.com # for quietpc.com
- .jungle.com
- .scan.co.uk
-
-
-# These sites require pop-ups too :( We'll combine our 'shop'
-# alias with two other actions into one rule to allow all popups.
- { shop -kill-popups -filter{popups} }
- .dabs.com
- .overclockers.co.uk
-
-
-# The 'Fast-redirects' action breaks some sites. Disable this action
-# for these known sensitive sites:
- { -fast-redirects }
- login.yahoo.com
- edit.europe.yahoo.com
- .google.com
- .altavista.com/.*(like|url|link):http
- .altavista.com/trans.*urltext=http
- .nytimes.com
-
-
-# Define which file types will be treated as images. Important
-# for ad blocking.
- { +handle-as-image }
- /.*\.(gif|jpe?g|png|bmp|ico)
-
-
-# Now lets list some domains that are known ad generators. And
-# our alias that we use here will block these as well as force
-# them to be treated as images. This combination of actions is
-# important for ad blocking. What the browser will show instead is
-# determined by the setting of "+set-image-blocker"
- { +imageblock }
- ar.atwola.com
- .ad.doubleclick.net
- .a.yimg.com/(?:(?!/i/).)*$
- .a[0-9].yimg.com/(?:(?!/i/).)*$
- bs*.gsanet.com
- bs*.einets.com
- .qkimg.net
- ad.*.doubleclick.net
-
-
-# These will just simply be blocked. They will generate the BLOCKED
-# banner page, if matched. Heavy use of wildcards and regular
-# expressions in this example. Enable block action:
- { +block }
- ad*.
- .*ads.
- banner?.
- count*.
- /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
- /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
- .hitbox.com
-
-
-# The above block section will probably inadvertantly catch some
-# sites we DO NOT want blocked via the wildcards and regular expressions.
-# Now let's set exceptions to the exceptions so the good guys get better
-# treatment. Disable block action:
- { -block }
- advogato.org
- adsl.
- ad[ud]*.
- advice.
-# Let's just trust all .edu top level domains.
- .edu
- www.ugu.com/sui/ugu/adv
-# We'll need to access to path names containing 'download'
- .*downloads.
- /downloads/
-# 'adv' is for globalintersec and means advanced, not advertisement
- www.globalintersec.com/adv
-
-
-# Don't filter *anything* from our friends at sourceforge.
-# Notice we don't have to name the individual filter
-# identifiers -- we just turn them all off in one fell swoop.
-# Disable all filters for this one site:
- { -filter }
- .sourceforge.net
-
-
-So far we are painting with a broad brush by setting general policies. The
-above would be a reasonable starting point for many situations. Now, we want to
-be more specific and have customized rules that are more suitable to our
-personal habits and preferences. These would be for narrowly defined situations
-like your ISP or your bank, and should be placed in user.action, which is
-parsed after all other actions files and should not be clobbered by upgrades.
-So any settings here, will have the last word and over-ride any previously
-defined actions.
-
-Now a few examples of some things that one might do with a user.action file.
-
-# Sample user.action file.
-
-# Any aliases you want to use need to be re-defined here.
-# Alias to turn off cookie handling, ie allow all cookies unmolested.
- -prevent-cookies = -prevent-setting-cookies -prevent-reading-cookies \
- -session-cookies-only
-
-# Fragile sites should have the minimum changes:
- fragile = -block -deanimate-gifs -fast-redirects -filter -hide-referer \
- -prevent-cookies -kill-popups
-
-# Allow persistent cookies for a few regular sites that we
-# trust via our above alias. These will be saved from one browser session
-# to the next. We are explicity turning off any and all cookie handling,
-# even though the prevent-*-cookie settings were disabled in our above
-# default.action anyway. So cookies from these domains will come through
-# unmolested.
- { -prevent-cookies }
- .sun.com
- .yahoo.com
- .msdn.microsoft.com
- .redhat.com
-
-
-# My ISP uses obnoxious self promoting images on many pages.
-# Nuke them :) Note that "+handle-as-image" need not be specified,
-# since all URLs ending in .gif will be tagged as images by the
-# general rules in default.action anyway.
- { +block }
- www.my-isp-example.com/logo[0-9].gif
-
-
-# Say the site where you do your homebanking needs to open
-# popup windows, but you have chosen to kill popups by
-# default. This will allow it for your-example-bank.com:
-#
- { -filter{popups} -kill-popups }
- .my-example-bank.com
+ --------------------------------------------------------------------------
+
+ 8.5.37. set-image-blocker
+
+ Typical use:
+
+ Choose the replacement for blocked images
+
+ Effect:
+
+ This action alone doesn't do anything noticeable. If both block
+ and handle-as-image also apply, i.e. if the request is to be
+ blocked as an image, then the parameter of this action decides
+ what will be sent as a replacement.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ * "pattern" to send a built-in checkerboard pattern image. The
+ image is visually decent, scales very well, and makes it
+ obvious where banners were busted.
+
+ * "blank" to send a built-in transparent image. This makes
+ banners disappear completely, but makes it hard to detect
+ where Privoxy has blocked images on a given page and
+ complicates troubleshooting if Privoxy has blocked innocent
+ images, like navigation icons.
+
+ * "target-url" to send a redirect to target-url. You can
+ redirect to any image anywhere, even in your local filesystem
+ via "file:///" URL. (But note that not all browsers support
+ redirecting to a local file system).
+
+ A good application of redirects is to use special
+ Privoxy-built-in URLs, which send the built-in images, as
+ target-url. This has the same visual effect as specifying
+ "blank" or "pattern" in the first place, but enables your
+ browser to cache the replacement image, instead of requesting
+ it over and over again.
+
+ Notes:
+
+ The URLs for the built-in images are
+ "http://config.privoxy.org/send-banner?type=type", where type is
+ either "blank" or "pattern".
+
+ There is a third (advanced) type, called "auto". It is NOT to be
+ used in set-image-blocker, but meant for use from filters. Auto
+ will select the type of image that would have applied to the
+ referring page, had it been an image.
+
+ Example usage:
+
+ Built-in pattern:
+
+ +set-image-blocker{pattern}
+
+ Redirect to the BSD daemon:
+ +set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}
-# This site is delicate, and requires kid-glove
-# treatment.
- { fragile }
- .forbes.com
-
+ Redirect to the built-in pattern for better caching:
--------------------------------------------------------------------------------
+ +set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}
-8.6. Aliases
+ --------------------------------------------------------------------------
-Custom "actions", known to Privoxy as "aliases", can be defined by combining
-other "actions". These can in turn be invoked just like the built-in "actions".
-Currently, an alias can contain any character except space, tab, "=", "{" or "}
-". But please use only "a"- "z", "0"-"9", "+", and "-". Alias names are not
-case sensitive, and must be defined before other actions in the actions file!
-And there can only be one set of "aliases" defined per file. Each actions file
-may have its own aliases, but they are only visible within that file. Aliases
-do not requir a "+" or "-" sign in front, since they are merely expanded.
+ 8.5.38. treat-forbidden-connects-like-blocks
-Now let's define a few aliases:
+ Typical use:
- # Useful custom aliases we can use later. These must come first!
+ Block forbidden connects with an easy to find error message.
+
+ Effect:
+
+ If this action is enabled, Privoxy no longer makes a difference
+ between forbidden connects and ordinary blocks.
+
+ Type:
+
+ Boolean
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ By default Privoxy answers forbidden "Connect" requests with a
+ short error message inside the headers. If the browser doesn't
+ display headers (most don't), you just see an empty page.
+
+ With this action enabled, Privoxy displays the message that is
+ used for ordinary blocks instead. If you decide to make an
+ exception for the page in question, you can do so by following the
+ "See why" link.
+
+ For "Connect" requests the clients tell Privoxy which host they
+ are interested in, but not which document they plan to get later.
+ As a result, the "Go there anyway" wouldn't work and is therefore
+ suppressed.
+
+ Example usage:
+
+ +treat-forbidden-connects-like-blocks
+
+ --------------------------------------------------------------------------
+
+ 8.5.39. Summary
+
+ Note that many of these actions have the potential to cause a page to
+ misbehave, possibly even not to display at all. There are many ways a site
+ designer may choose to design his site, and what HTTP header content, and
+ other criteria, he may depend on. There is no way to have hard and fast
+ rules for all sites. See the Appendix for a brief example on
+ troubleshooting actions.
+
+ --------------------------------------------------------------------------
+
+ 8.6. Aliases
+
+ Custom "actions", known to Privoxy as "aliases", can be defined by
+ combining other actions. These can in turn be invoked just like the
+ built-in actions. Currently, an alias name can contain any character
+ except space, tab, "=", "{" and "}", but we strongly recommend that you
+ only use "a" to "z", "0" to "9", "+", and "-". Alias names are not case
+ sensitive, and are not required to start with a "+" or "-" sign, since
+ they are merely textually expanded.
+
+ Aliases can be used throughout the actions file, but they must be defined
+ in a special section at the top of the file! And there can only be one
+ such section per actions file. Each actions file may have its own alias
+ section, and the aliases defined in it are only visible within that file.
+
+ There are two main reasons to use aliases: One is to save typing for
+ frequently used combinations of actions, the other one is a gain in
+ flexibility: If you decide once how you want to handle shops by defining
+ an alias called "shop", you can later change your policy on shops in one
+ place, and your changes will take effect everywhere in the actions file
+ where the "shop" alias is used. Calling aliases by their purpose also
+ makes your actions files more readable.
+
+ Currently, there is one big drawback to using aliases, though: Privoxy's
+ built-in web-based action file editor honors aliases when reading the
+ actions files, but it expands them before writing. So the effects of your
+ aliases are of course preserved, but the aliases themselves are lost when
+ you edit sections that use aliases with it.
+
+ Now let's define some aliases...
+
+ # Useful custom aliases we can use later.
+ #
+ # Note the (required!) section header line and that this section
+ # must be at the top of the actions file!
+ #
{{alias}}
- +prevent-cookies = +prevent-setting-cookies +prevent-reading-cookies
- -prevent-cookies = -prevent-setting-cookies -prevent-reading-cookies
- fragile =
- -block -prevent-cookies -filter -fast-redirects -hide-referer -kill-popups
- shop = -prevent-cookies -filter -fast-redirects
- +imageblock = +block +handle-as-image
-
- # Aliases defined from other aliases, for people who don't like to type
- # too much: ;-)
- c0 = +prevent-cookies
- c1 = -prevent-cookies
- #... etc. Customize to your heart's content.
-
-
-Some examples using our "shop" and "fragile" aliases from above. These would
-appear in the lower sections of an actions file as exceptions to the default
-actions (as defined in the upper section):
-
- # These sites are very complex and require
- # minimal interference.
- {fragile}
- .office.microsoft.com
- .windowsupdate.microsoft.com
- .nytimes.com
-
- # Shopping sites - but we still want to block ads.
- {shop}
- .quietpc.com
- .worldpay.com # for quietpc.com
- .scan.co.uk
-
- # These shops require pop-ups also
- {shop -kill-popups}
- .dabs.com
- .overclockers.co.uk
-
-
-The "shop" and "fragile" aliases are often used for "problem" sites that
-require most actions to be disabled in order to function properly.
-
--------------------------------------------------------------------------------
-
-9. The Filter File
-
-Any web page can be dynamically modified with the filter file. This
-modification can be removal, or re-writing, of any web page content, including
-tags and non-visible content. The default filter file is oddly enough
-default.filter, located in the config directory.
-
-This is potentially a very powerful feature, and requires knowledge of both
-"regular expression" and HTML in order create custom filters. But, there are a
-number of useful filters included with Privoxy for many common situations.
-
-The included example file is divided into sections. Each section begins with
-the FILTER keyword, followed by the identifier for that section, e.g. "FILTER:
-webbugs". Each section performs a similar type of filtering, such as
-"html-annoyances".
-
-This file uses regular expressions to alter or remove any string in the target
-page. The expressions can only operate on one line at a time. Some examples
-from the included default default.filter:
-
-Stop web pages from displaying annoying messages in the status bar by deleting
-such references:
-
- FILTER: html-annoyances
-
- # New browser windows should be resizeable and have a location and status
- # bar. Make it so.
+
+ # These aliases just save typing later:
+ # (Note that some already use other aliases!)
#
- s/resizable="?(no|0)"?/resizable=1/ig s/noresize/yesresize/ig
- s/location="?(no|0)"?/location=1/ig s/status="?(no|0)"?/status=1/ig
- s/scrolling="?(no|0|Auto)"?/scrolling=1/ig
- s/menubar="?(no|0)"?/menubar=1/ig
+ +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
+ -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
+ +block-as-image = +block +handle-as-image
+ allow-all-cookies = -crunch-all-cookies -session-cookies-only -filter{content-cookies}
- # The <BLINK> tag was a crime!
+ # These aliases define combinations of actions
+ # that are useful for certain types of sites:
#
- s*<blink>|</blink>**ig
+ fragile = -block -filter -crunch-all-cookies -fast-redirects -hide-referrer -kill-popups -prevent-compression
- # Is this evil?
+ shop = -crunch-all-cookies -filter{all-popups} -kill-popups
+
+ # Short names for other aliases, for really lazy people ;-)
#
- #s/framespacing="?(no|0)"?//ig
- #s/margin(height|width)=[0-9]*//gi
-
+ c0 = +crunch-all-cookies
+ c1 = -crunch-all-cookies
+
+ ...and put them to use. These sections would appear in the lower part of
+ an actions file and define exceptions to the default actions (as specified
+ further up for the "/" pattern):
+
+ # These sites are either very complex or very keen on
+ # user data and require minimal interference to work:
+ #
+ {fragile}
+ .office.microsoft.com
+ .windowsupdate.microsoft.com
+ # Gmail is really mail.google.com, not gmail.com
+ mail.google.com
+
+ # Shopping sites:
+ # Allow cookies (for setting and retrieving your customer data)
+ #
+ {shop}
+ .quietpc.com
+ .worldpay.com # for quietpc.com
+ mybank.example.com
+
+ # These shops require pop-ups:
+ #
+ {-kill-popups -filter{all-popups} -filter{unsolicited-popups}}
+ .dabs.com
+ .overclockers.co.uk
+
+ Aliases like "shop" and "fragile" are typically used for "problem" sites
+ that require more than one action to be disabled in order to function
+ properly.
-Just for kicks, replace any occurrence of "Microsoft" with "MicroSuck", and
-have a little fun with topical buzzwords:
+ --------------------------------------------------------------------------
- FILTER: fun
+ 8.7. Actions Files Tutorial
- s/microsoft(?!.com)/MicroSuck/ig
+ The above chapters have shown which actions files there are and how they
+ are organized, how actions are specified and applied to URLs, how patterns
+ work, and how to define and use aliases. Now, let's look at an example
+ default.action and user.action file and see how all these pieces come
+ together:
- # Buzzword Bingo:
+ --------------------------------------------------------------------------
+
+ 8.7.1. default.action
+
+ Every config file should start with a short comment stating its purpose:
+
+ # Sample default.action file <ijbswa-developers@lists.sourceforge.net>
+
+ Then, since this is the default.action file, the first section is a
+ special section for internal use that you needn't change or worry about:
+
+ ##########################################################################
+ # Settings -- Don't change! For internal Privoxy use ONLY.
+ ##########################################################################
+
+ {{settings}}
+ for-privoxy-version=3.0
+
+ After that comes the (optional) alias section. We'll use the example
+ section from the above chapter on aliases, that also explains why and how
+ aliases are used:
+
+##########################################################################
+# Aliases
+##########################################################################
+{{alias}}
+
+ # These aliases just save typing later:
+ # (Note that some already use other aliases!)
+ #
+ +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
+ -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
+ +block-as-image = +block +handle-as-image
+ mercy-for-cookies = -crunch-all-cookies -session-cookies-only -filter{content-cookies}
+
+ # These aliases define combinations of actions
+ # that are useful for certain types of sites:
#
- s/industry-leading|cutting-edge|award-winning/<font color=red><b>BINGO!</b></
-font>/ig
-
+ fragile = -block -filter -crunch-all-cookies -fast-redirects -hide-referrer -kill-popups
+ shop = -crunch-all-cookies -filter{all-popups} -kill-popups
+
+ Now come the regular sections, i.e. sets of actions, accompanied by URL
+ patterns to which they apply. Remember all actions are disabled when
+ matching starts, so we have to explicitly enable the ones we want.
+
+ The first regular section is probably the most important. It has only one
+ pattern, "/", but this pattern matches all URLs. Therefore, the set of
+ actions used in this "default" section will be applied to all requests as
+ a start. It can be partly or wholly overridden by later matches further
+ down this file, or in user.action, but it will still be largely
+ responsible for your overall browsing experience.
+
+ Again, at the start of matching, all actions are disabled, so there is no
+ need to disable any actions here. (Remember: a "+" preceding the action
+ name enables the action, a "-" disables!). Also note how this long line
+ has been made more readable by splitting it into multiple lines with line
+ continuation.
+
+ ##########################################################################
+ # "Defaults" section:
+ ##########################################################################
+ { \
+ +deanimate-gifs \
+ +filter{html-annoyances} \
+ +filter{refresh-tags} \
+ +filter{webbugs} \
+ +filter{ie-exploits} \
+ +hide-forwarded-for-headers \
+ +hide-from-header{block} \
+ +hide-referrer{forge} \
+ +prevent-compression \
+ +session-cookies-only \
+ +set-image-blocker{pattern} \
+ }
+ / # forward slash will match *all* potential URL patterns.
+
+ The default behavior is now set.
+
+ The first of our specialized sections is concerned with "fragile" sites,
+ i.e. sites that require minimum interference, because they are either very
+ complex or very keen on tracking you (and have mechanisms in place that
+ make them unusable for people who avoid being tracked). We will simply use
+ our pre-defined fragile alias instead of stating the list of actions
+ explicitly:
+
+ ##########################################################################
+ # Exceptions for sites that'll break under the default action set:
+ ##########################################################################
+
+ # "Fragile" Use a minimum set of actions for these sites (see alias above):
+ #
+ { fragile }
+ .office.microsoft.com # surprise, surprise!
+ .windowsupdate.microsoft.com
+ mail.google.com
+
+ Shopping sites are not as fragile, but they typically require cookies to
+ log in, and pop-up windows for shopping carts or item details. Again,
+ we'll use a pre-defined alias:
+
+ # Shopping sites:
+ #
+ { shop }
+ .quietpc.com
+ .worldpay.com # for quietpc.com
+ .jungle.com
+ .scan.co.uk
+
+ The fast-redirects action, which we enabled per default above, breaks some
+ sites. So disable it for popular sites where we know it misbehaves:
+
+ { -fast-redirects }
+ login.yahoo.com
+ edit.*.yahoo.com
+ .google.com
+ .altavista.com/.*(like|url|link):http
+ .altavista.com/trans.*urltext=http
+ .nytimes.com
+
+ It is important that Privoxy knows which URLs belong to images, so that if
+ they are to be blocked, a substitute image can be sent, rather than an
+ HTML page. Contacting the remote site to find out is not an option, since
+ it would destroy the loading time advantage of banner blocking, and it
+ would feed the advertisers (in terms of money and information). We can
+ mark any URL as an image with the handle-as-image action, and marking all
+ URLs that end in a known image file extension is a good start:
+
+ ##########################################################################
+ # Images:
+ ##########################################################################
+
+ # Define which file types will be treated as images, in case they get
+ # blocked further down this file:
+ #
+ { +handle-as-image }
+ /.*\.(gif|jpe?g|png|bmp|ico)$
+
+ And then there are known banner sources. They often use scripts to
+ generate the banners, so it won't be visible from the URL that the request
+ is for an image. Hence we block them and mark them as images in one go,
+ with the help of our +block-as-image alias defined above. (We could of
+ course just as well use +block +handle-as-image here.) Remember that the
+ type of the replacement image is chosen by the set-image-blocker action.
+ Since all URLs have matched the default section with its
+ +set-image-blocker{pattern} action before, it still applies and needn't be
+ repeated:
+
+ # Known ad generators:
+ #
+ { +block-as-image }
+ ar.atwola.com
+ .ad.doubleclick.net
+ .ad.*.doubleclick.net
+ .a.yimg.com/(?:(?!/i/).)*$
+ .a[0-9].yimg.com/(?:(?!/i/).)*$
+ bs*.gsanet.com
+ .qkimg.net
+
+ One of the most important jobs of Privoxy is to block banners. Many of
+ these can be "blocked" by the filter{banners-by-size} action, which we
+ enabled above, and which deletes the references to banner images from the
+ pages while they are loaded, so the browser doesn't request them anymore,
+ and hence they don't need to be blocked here. But this naturally doesn't
+ catch all banners, and some people choose not to use filters, so we need a
+ comprehensive list of patterns for banner URLs here, and apply the block
+ action to them.
+
+ First comes many generic patterns, which do most of the work, by matching
+ typical domain and path name components of banners. Then comes a list of
+ individual patterns for specific sites, which is omitted here to keep the
+ example short:
+
+ ##########################################################################
+ # Block these fine banners:
+ ##########################################################################
+ { +block }
+
+ # Generic patterns:
+ #
+ ad*.
+ .*ads.
+ banner?.
+ count*.
+ /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
+ /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
+
+ # Site-specific patterns (abbreviated):
+ #
+ .hitbox.com
+
+ It's quite remarkable how many advertisers actually call their banner
+ servers ads.company.com, or call the directory in which the banners are
+ stored simply "banners". So the above generic patterns are surprisingly
+ effective.
+
+ But being very generic, they necessarily also catch URLs that we don't
+ want to block. The pattern .*ads. e.g. catches "nasty-ads.nasty-corp.com"
+ as intended, but also "downloads.sourcefroge.net" or
+ "adsl.some-provider.net." So here come some well-known exceptions to the
+ +block section above.
+
+ Note that these are exceptions to exceptions from the default! Consider
+ the URL "downloads.sourcefroge.net": Initially, all actions are
+ deactivated, so it wouldn't get blocked. Then comes the defaults section,
+ which matches the URL, but just deactivates the block action once again.
+ Then it matches .*ads., an exception to the general non-blocking policy,
+ and suddenly +block applies. And now, it'll match .*loads., where -block
+ applies, so (unless it matches again further down) it ends up with no
+ block action applying.
+
+ ##########################################################################
+ # Save some innocent victims of the above generic block patterns:
+ ##########################################################################
+
+ # By domain:
+ #
+ { -block }
+ adv[io]*. # (for advogato.org and advice.*)
+ adsl. # (has nothing to do with ads)
+ adobe. # (has nothing to do with ads either)
+ ad[ud]*. # (adult.* and add.*)
+ .edu # (universities don't host banners (yet!))
+ .*loads. # (downloads, uploads etc)
+
+ # By path:
+ #
+ /.*loads/
+
+ # Site-specific:
+ #
+ www.globalintersec.com/adv # (adv = advanced)
+ www.ugu.com/sui/ugu/adv
+
+ Filtering source code can have nasty side effects, so make an exception
+ for our friends at sourceforge.net, and all paths with "cvs" in them. Note
+ that -filter disables all filters in one fell swoop!
+
+ # Don't filter code!
+ #
+ { -filter }
+ /(.*/)?cvs
+ bugzilla.
+ developer.
+ wiki.
+ .sourceforge.net
+
+ The actual default.action is of course much more comprehensive, but we
+ hope this example made clear how it works.
+
+ --------------------------------------------------------------------------
+
+ 8.7.2. user.action
+
+ So far we are painting with a broad brush by setting general policies,
+ which would be a reasonable starting point for many people. Now, you might
+ want to be more specific and have customized rules that are more suitable
+ to your personal habits and preferences. These would be for narrowly
+ defined situations like your ISP or your bank, and should be placed in
+ user.action, which is parsed after all other actions files and hence has
+ the last word, over-riding any previously defined actions. user.action is
+ also a safe place for your personal settings, since default.action is
+ actively maintained by the Privoxy developers and you'll probably want to
+ install updated versions from time to time.
+
+ So let's look at a few examples of things that one might typically do in
+ user.action:
+
+ # My user.action file. <fred@example.com>
+
+ As aliases are local to the actions file that they are defined in, you
+ can't use the ones from default.action, unless you repeat them here:
+
+# Aliases are local to the file they are defined in.
+# (Re-)define aliases for this file:
+#
+{{alias}}
+#
+# These aliases just save typing later, and the alias names should
+# be self explanatory.
+#
++crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
+-crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
+ allow-all-cookies = -crunch-all-cookies -session-cookies-only
+ allow-popups = -filter{all-popups} -kill-popups
++block-as-image = +block +handle-as-image
+-block-as-image = -block
+
+# These aliases define combinations of actions that are useful for
+# certain types of sites:
+#
+fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referrer -kill-popups
+shop = -crunch-all-cookies allow-popups
+
+# Allow ads for selected useful free sites:
+#
+allow-ads = -block -filter{banners-by-size} -filter{banners-by-link}
+
+# Alias for specific file types that are text, but might have conflicting
+# MIME types. We want the browser to force these to be text documents.
+handle-as-text = -filter +-content-type-overwrite{text/plain} +-force-text-mode -hide-content-disposition
+
+
+
+ Say you have accounts on some sites that you visit regularly, and you
+ don't want to have to log in manually each time. So you'd like to allow
+ persistent cookies for these sites. The allow-all-cookies alias defined
+ above does exactly that, i.e. it disables crunching of cookies in any
+ direction, and the processing of cookies to make them only temporary.
+
+ { allow-all-cookies }
+ sourceforge.net
+ .yahoo.com
+ .msdn.microsoft.com
+ .redhat.com
+
+ Your bank is allergic to some filter, but you don't know which, so you
+ disable them all:
+
+ { -filter }
+ .your-home-banking-site.com
+
+ Some file types you may not want to filter for various reasons:
+
+ # Technical documentation is likely to contain strings that might
+ # erroneously get altered by the JavaScript-oriented filters:
+ #
+ .tldp.org
+ /(.*/)?selfhtml/
+
+ # And this stupid host sends streaming video with a wrong MIME type,
+ # so that Privoxy thinks it is getting HTML and starts filtering:
+ #
+ stupid-server.example.com/
+
+ Example of a simple block action. Say you've seen an ad on your favourite
+ page on example.com that you want to get rid of. You have right-clicked
+ the image, selected "copy image location" and pasted the URL below while
+ removing the leading http://, into a { +block } section. Note that {
+ +handle-as-image } need not be specified, since all URLs ending in .gif
+ will be tagged as images by the general rules as set in default.action
+ anyway:
+
+ { +block }
+ www.example.com/nasty-ads/sponsor\.gif
+ another.example.net/more/junk/here/
+
+ The URLs of dynamically generated banners, especially from large banner
+ farms, often don't use the well-known image file name extensions, which
+ makes it impossible for Privoxy to guess the file type just by looking at
+ the URL. You can use the +block-as-image alias defined above for these
+ cases. Note that objects which match this rule but then turn out NOT to be
+ an image are typically rendered as a "broken image" icon by the browser.
+ Use cautiously.
+
+ { +block-as-image }
+ .doubleclick.net
+ .fastclick.net
+ /Realmedia/ads/
+ ar.atwola.com/
+
+ Now you noticed that the default configuration breaks Forbes Magazine, but
+ you were too lazy to find out which action is the culprit, and you were
+ again too lazy to give feedback, so you just used the fragile alias on the
+ site, and -- whoa! -- it worked. The fragile aliases disables those
+ actions that are most likely to break a site. Also, good for testing
+ purposes to see if it is Privoxy that is causing the problem or not. We
+ later find other regular sites that misbehave, and add those to our
+ personalized list of troublemakers:
+
+ { fragile }
+ .forbes.com
+ webmail.example.com
+ .mybank.com
+
+ You like the "fun" text replacements in default.filter, but it is disabled
+ in the distributed actions file. So you'd like to turn it on in your
+ private, update-safe config, once and for all:
+
+ { +filter{fun} }
+ / # For ALL sites!
+
+ Note that the above is not really a good idea: There are exceptions to the
+ filters in default.action for things that really shouldn't be filtered,
+ like code on CVS->Web interfaces. Since user.action has the last word,
+ these exceptions won't be valid for the "fun" filtering specified here.
+
+ You might also worry about how your favourite free websites are funded,
+ and find that they rely on displaying banner advertisements to survive. So
+ you might want to specifically allow banners for those sites that you feel
+ provide value to you:
+
+ { allow-ads }
+ .sourceforge.net
+ .slashdot.org
+ .osdn.net
+
+ Note that allow-ads has been aliased to -block, -filter{banners-by-size},
+ and -filter{banners-by-link} above.
+
+ Invoke another alias here to force an over-ride of the MIME type
+ application/x-sh which typically would open a download type dialog. In my
+ case, I want to look at the shell script, and then I can save it should I
+ choose to.
+
+ { handle-as-text }
+ /.*\.sh$
+
+ user.action is generally the best place to define exceptions and additions
+ to the default policies of default.action. Some actions are safe to have
+ their default policies set here though. So let's set a default policy to
+ have a "blank" image as opposed to the checkerboard pattern for ALL sites.
+ "/" of course matches all URL paths and patterns:
+
+ { +set-image-blocker{blank} }
+ / # ALL sites
+
+ --------------------------------------------------------------------------
+
+9. Filter Files
+
+ On-the-fly text substitutions need to be defined in a "filter file". Once
+ defined, they can then be invoked as an "action".
+
+ Privoxy supports three different filter actions: filter to rewrite the
+ content that is send to the client, client-header-filter to rewrite
+ headers that are send by the client, and server-header-filter to rewrite
+ headers that are send by the server.
+
+ Privoxy also supports two tagger actions: client-header-tagger and
+ server-header-tagger. Taggers and filters use the same syntax in the
+ filter files, the difference is that taggers don't modify the text they
+ are filtering, but use a rewritten version of the filtered text as tag.
+ The tags can then be used to change the applying actions through sections
+ with tag-patterns.
+
+ Multiple filter files can be defined through the filterfile config
+ directive. The filters as supplied by the developers are located in
+ default.filter. It is recommended that any locally defined or modified
+ filters go in a separately defined file such as user.filter.
+
+ Common tasks for content filters are to eliminate common annoyances in
+ HTML and JavaScript, such as pop-up windows, exit consoles, crippled
+ windows without navigation tools, the infamous <BLINK> tag etc, to
+ suppress images with certain width and height attributes (standard banner
+ sizes or web-bugs), or just to have fun.
+
+ Enabled content filters are applied to any content whose "Content Type"
+ header is recognised as a sign of text-based content, with the exception
+ of text/plain. Use the force-text-mode action to also filter other
+ content.
+
+ Substitutions are made at the source level, so if you want to "roll your
+ own" filters, you should first be familiar with HTML syntax, and, of
+ course, regular expressions.
+
+ Just like the actions files, the filter file is organized in sections,
+ which are called filters here. Each filter consists of a heading line,
+ that starts with one of the keywords FILTER:, CLIENT-HEADER-FILTER: or
+ SERVER-HEADER-FILTER: followed by the filter's name, and a short (one
+ line) description of what it does. Below that line come the jobs, i.e.
+ lines that define the actual text substitutions. By convention, the name
+ of a filter should describe what the filter eliminates. The comment is
+ used in the web-based user interface.
+
+ Once a filter called name has been defined in the filter file, it can be
+ invoked by using an action of the form +filter{name} in any actions file.
+
+ Filter definitions start with a header line that contains the filter type,
+ the filter name and the filter description. A content filter header line
+ for a filter called "foo" could look like this:
+
+ FILTER: foo Replace all "foo" with "bar"
+
+ Below that line, and up to the next header line, come the jobs that define
+ what text replacements the filter executes. They are specified in a syntax
+ that imitates Perl's s/// operator. If you are familiar with Perl, you
+ will find this to be quite intuitive, and may want to look at the PCRS
+ documentation for the subtle differences to Perl behaviour. Most notably,
+ the non-standard option letter U is supported, which turns the default to
+ ungreedy matching.
+
+ If you are new to "Regular Expressions", you might want to take a look at
+ the Appendix on regular expressions, and see the Perl manual for the s///
+ operator's syntax and Perl-style regular expressions in general. The below
+ examples might also help to get you started.
+
+ --------------------------------------------------------------------------
+
+ 9.1. Filter File Tutorial
+
+ Now, let's complete our "foo" content filter. We have already defined the
+ heading, but the jobs are still missing. Since all it does is to replace
+ "foo" with "bar", there is only one (trivial) job needed:
+
+ s/foo/bar/
+
+ But wait! Didn't the comment say that all occurrences of "foo" should be
+ replaced? Our current job will only take care of the first "foo" on each
+ page. For global substitution, we'll need to add the g option:
+
+ s/foo/bar/g
+
+ Our complete filter now looks like this:
+
+ FILTER: foo Replace all "foo" with "bar"
+ s/foo/bar/g
+
+ Let's look at some real filters for more interesting examples. Here you
+ see a filter that protects against some common annoyances that arise from
+ JavaScript abuse. Let's look at its jobs one after the other:
+
+FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse
+
+# Get rid of JavaScript referrer tracking. Test page: http://www.randomoddness.com/untitled.htm
+#
+s|(<script.*)document\.referrer(.*</script>)|$1"Not Your Business!"$2|Usg
+
+ Following the header line and a comment, you see the job. Note that it
+ uses | as the delimiter instead of /, because the pattern contains a
+ forward slash, which would otherwise have to be escaped by a backslash
+ (\).
+
+ Now, let's examine the pattern: it starts with the text <script.* enclosed
+ in parentheses. Since the dot matches any character, and * means: "Match
+ an arbitrary number of the element left of myself", this matches
+ "<script", followed by any text, i.e. it matches the whole page, from the
+ start of the first <script> tag.
+
+ That's more than we want, but the pattern continues: document\.referrer
+ matches only the exact string "document.referrer". The dot needed to be
+ escaped, i.e. preceded by a backslash, to take away its special meaning as
+ a joker, and make it just a regular dot. So far, the meaning is: Match
+ from the start of the first <script> tag in a the page, up to, and
+ including, the text "document.referrer", if both are present in the page
+ (and appear in that order).
+
+ But there's still more pattern to go. The next element, again enclosed in
+ parentheses, is .*</script>. You already know what .* means, so the whole
+ pattern translates to: Match from the start of the first <script> tag in a
+ page to the end of the last <script> tag, provided that the text
+ "document.referrer" appears somewhere in between.
+
+ This is still not the whole story, since we have ignored the options and
+ the parentheses: The portions of the page matched by sub-patterns that are
+ enclosed in parentheses, will be remembered and be available through the
+ variables $1, $2, ... in the substitute. The U option switches to ungreedy
+ matching, which means that the first .* in the pattern will only "eat up"
+ all text in between "<script" and the first occurrence of
+ "document.referrer", and that the second .* will only span the text up to
+ the first "</script>" tag. Furthermore, the s option says that the match
+ may span multiple lines in the page, and the g option again means that the
+ substitution is global.
+
+ So, to summarize, the pattern means: Match all scripts that contain the
+ text "document.referrer". Remember the parts of the script from (and
+ including) the start tag up to (and excluding) the string
+ "document.referrer" as $1, and the part following that string, up to and
+ including the closing tag, as $2.
+
+ Now the pattern is deciphered, but wasn't this about substituting things?
+ So lets look at the substitute: $1"Not Your Business!"$2 is easy to read:
+ The text remembered as $1, followed by "Not Your Business!" (including the
+ quotation marks!), followed by the text remembered as $2. This produces an
+ exact copy of the original string, with the middle part (the
+ "document.referrer") replaced by "Not Your Business!".
+
+ The whole job now reads: Replace "document.referrer" by "Not Your
+ Business!" wherever it appears inside a <script> tag. Note that this job
+ won't break JavaScript syntax, since both the original and the replacement
+ are syntactically valid string objects. The script just won't have access
+ to the referrer information anymore.
+
+ We'll show you two other jobs from the JavaScript taming department, but
+ this time only point out the constructs of special interest:
+
+ # The status bar is for displaying link targets, not pointless blahblah
+ #
+ s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig
+
+ \s stands for whitespace characters (space, tab, newline, carriage return,
+ form feed), so that \s* means: "zero or more whitespace". The ? in .*?
+ makes this matching of arbitrary text ungreedy. (Note that the U option is
+ not set). The ['"] construct means: "a single or a double quote". Finally,
+ \1 is a back-reference to the first parenthesis just like $1 above, with
+ the difference that in the pattern, a backslash indicates a
+ back-reference, whereas in the substitute, it's the dollar.
+
+ So what does this job do? It replaces assignments of single- or
+ double-quoted strings to the "window.status" object with a dummy
+ assignment (using a variable name that is hopefully odd enough not to
+ conflict with real variables in scripts). Thus, it catches many cases
+ where e.g. pointless descriptions are displayed in the status bar instead
+ of the link target when you move your mouse over links.
+
+# Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html
+#
+s/(<body [^>]*)onunload(.*>)/$1never$2/iU
+
+ Including the OnUnload event binding in the HTML DOM was a CRIME. When I
+ close a browser window, I want it to close and die. Basta. This job
+ replaces the "onunload" attribute in "<body>" tags with the dummy word
+ never. Note that the i option makes the pattern matching case-insensitive.
+ Also note that ungreedy matching alone doesn't always guarantee a minimal
+ match: In the first parenthesis, we had to use [^>]* instead of .* to
+ prevent the match from exceeding the <body> tag if it doesn't contain
+ "OnUnload", but the page's content does.
+
+ The last example is from the fun department:
+
+ FILTER: fun Fun text replacements
+
+ # Spice the daily news:
+ #
+ s/microsoft(?!\.com)/MicroSuck/ig
+
+ Note the (?!\.com) part (a so-called negative lookahead) in the job's
+ pattern, which means: Don't match, if the string ".com" appears directly
+ following "microsoft" in the page. This prevents links to microsoft.com
+ from being trashed, while still replacing the word everywhere else.
+
+ # Buzzword Bingo (example for extended regex syntax)
+ #
+ s* industry[ -]leading \
+ | cutting[ -]edge \
+ | customer[ -]focused \
+ | market[ -]driven \
+ | award[ -]winning # Comments are OK, too! \
+ | high[ -]performance \
+ | solutions[ -]based \
+ | unmatched \
+ | unparalleled \
+ | unrivalled \
+ *<font color="red"><b>BINGO!</b></font> \
+ *igx
+
+ The x option in this job turns on extended syntax, and allows for e.g. the
+ liberal use of (non-interpreted!) whitespace for nicer formatting.
+
+ You get the idea?
+
+ --------------------------------------------------------------------------
+
+ 9.2. The Pre-defined Filters
+
+ The distribution default.filter file contains a selection of pre-defined
+ filters for your convenience:
+
+ js-annoyances
+
+ The purpose of this filter is to get rid of particularly annoying
+ JavaScript abuse. To that end, it
+
+ * replaces JavaScript references to the browser's referrer
+ information with the string "Not Your Business!". This
+ compliments the hide-referrer action on the content level.
+
+ * removes the bindings to the DOM's unload event which we feel
+ has no right to exist and is responsible for most "exit
+ consoles", i.e. nasty windows that pop up when you close
+ another one.
+
+ * removes code that causes new windows to be opened with
+ undesired properties, such as being full-screen,
+ non-resizeable, without location, status or menu bar etc.
+
+ Use with caution. This is an aggressive filter, and can break
+ sites that rely heavily on JavaScript.
+
+ js-events
+
+ This is a very radical measure. It removes virtually all
+ JavaScript event bindings, which means that scripts can not react
+ to user actions such as mouse movements or clicks, window resizing
+ etc, anymore. Use with caution!
+
+ We strongly discourage using this filter as a default since it
+ breaks many legitimate scripts. It is meant for use only on
+ extra-nasty sites (should you really need to go there).
+
+ html-annoyances
+
+ This filter will undo many common instances of HTML based abuse.
+
+ The BLINK and MARQUEE tags are neutralized (yeah baby!), and
+ browser windows will be created as resizeable (as of course they
+ should be!), and will have location, scroll and menu bars -- even
+ if specified otherwise.
+
+ content-cookies
+
+ Most cookies are set in the HTTP dialog, where they can be
+ intercepted by the crunch-incoming-cookies and
+ crunch-outgoing-cookies actions. But web sites increasingly make
+ use of HTML meta tags and JavaScript to sneak cookies to the
+ browser on the content level.
+
+ This filter disables most HTML and JavaScript code that reads or
+ sets cookies. It cannot detect all clever uses of these types of
+ code, so it should not be relied on as an absolute fix. Use it
+ wherever you would also use the cookie crunch actions.
+
+ refresh tags
-Kill those pesky little web-bugs:
+ Disable any refresh tags if the interval is greater than nine
+ seconds (so that redirections done via refresh tags are not
+ destroyed). This is useful for dial-on-demand setups, or for those
+ who find this HTML feature annoying.
- # webbugs: Squish WebBugs (1x1 invisible GIFs used for user tracking)
- FILTER: webbugs
+ unsolicited-popups
- s/<img\s+[^>]*?(width|height)\s*=\s*['"]?1\D[^>]*?(width|height)\s*=\s*['"]?1
-(\D[^>]*?)?>/<!-- Squished WebBug -->/sig
-
+ This filter attempts to prevent only "unsolicited" pop-up windows
+ from opening, yet still allow pop-up windows that the user has
+ explicitly chosen to open. It was added in version 3.0.1, as an
+ improvement over earlier such filters.
--------------------------------------------------------------------------------
+ Technical note: The filter works by redefining the window.open
+ JavaScript function to a dummy function, PrivoxyWindowOpen(),
+ during the loading and rendering phase of each HTML page access,
+ and restoring the function afterward.
-9.1. The +filter Action
+ This is recommended only for browsers that cannot perform this
+ function reliably themselves. And be aware that some sites require
+ such windows in order to function normally. Use with caution.
-Filters are enabled with the "+filter" action from within one of the actions
-files. "+filter" requires one parameter, which should match one of the section
-identifiers in the filter file itself. Example:
+ all-popups
- +filter{html-annoyances}
+ Attempt to prevent all pop-up windows from opening. Note this
+ should be used with even more discretion than the above, since it
+ is more likely to break some sites that require pop-ups for normal
+ usage. Use with caution.
-This would activate that particular filter. Similarly, "+filter" can be turned
-off for selected sites as: "-filter{html-annoyances}". Remember too, all
-actions are off by default, unless they are explicity enabled in one of the
-actions files.
+ img-reorder
--------------------------------------------------------------------------------
+ This is a helper filter that has no value if used alone. It makes
+ the banners-by-size and banners-by-link (see below) filters more
+ effective and should be enabled together with them.
-10. Templates
+ banners-by-size
-When Privoxy displays one of its internal pages, such as a 404 Not Found error
-page (Privoxy must be running for link to work as intended), it uses the
-appropriate template. On Linux, BSD, and Unix, these are located in /etc/
-privoxy/templates by default. These may be customized, if desired.
-cgi-style.css is used to control the HTML attributes (fonts, etc).
+ This filter removes image tags purely based on what size they are.
+ Fortunately for us, many ads and banner images tend to conform to
+ certain standardized sizes, which makes this filter quite
+ effective for ad stripping purposes.
-The default Blocked (Privoxy needs to be running for page to display) banner
-page with the bright red top banner, is called just "blocked". This may be
-customized or replaced with something else if desired.
+ Occasionally this filter will cause false positives on images that
+ are not ads, but just happen to be of one of the standard banner
+ sizes.
--------------------------------------------------------------------------------
+ Recommended only for those who require extreme ad blocking. The
+ default block rules should catch 95+% of all ads without this
+ filter enabled.
+
+ banners-by-link
+
+ This is an experimental filter that attempts to kill any banners
+ if their URLs seem to point to known or suspected click trackers.
+ It is currently not of much value and is not recommended for use
+ by default.
+
+ webbugs
+
+ Webbugs are small, invisible images (technically 1X1 GIF images),
+ that are used to track users across websites, and collect
+ information on them. As an HTML page is loaded by the browser, an
+ embedded image tag causes the browser to contact a third-party
+ site, disclosing the tracking information through the requested
+ URL and/or cookies for that third-party domain, without the user
+ ever becoming aware of the interaction with the third-party site.
+ HTML-ized spam also uses a similar technique to verify email
+ addresses.
+
+ This filter removes the HTML code that loads such "webbugs".
+
+ tiny-textforms
+
+ A rather special-purpose filter that can be used to enlarge
+ textareas (those multi-line text boxes in web forms) and turn off
+ hard word wrap in them. It was written for the sourceforge.net
+ tracker system where such boxes are a nuisance, but it can be
+ handy on other sites, too.
+
+ It is not recommended to use this filter as a default.
+
+ jumping-windows
+
+ Many consider windows that move, or resize themselves to be
+ abusive. This filter neutralizes the related JavaScript code. Note
+ that some sites might not display or behave as intended when using
+ this filter. Use with caution.
+
+ frameset-borders
+
+ Some web designers seem to assume that everyone in the world will
+ view their web sites using the same browser brand and version,
+ screen resolution etc, because only that assumption could explain
+ why they'd use static frame sizes, yet prevent their frames from
+ being resized by the user, should they be too small to show their
+ whole content.
+
+ This filter removes the related HTML code. It should only be
+ applied to sites which need it.
+
+ demoronizer
+
+ Many Microsoft products that generate HTML use non-standard
+ extensions (read: violations) of the ISO 8859-1 aka Latin-1
+ character set. This can cause those HTML documents to display with
+ errors on standard-compliant platforms.
+
+ This filter translates the MS-only characters into Latin-1
+ equivalents. It is not necessary when using MS products, and will
+ cause corruption of all documents that use 8-bit character sets
+ other than Latin-1. It's mostly worthwhile for Europeans on non-MS
+ platforms, if weird garbage characters sometimes appear on some
+ pages, or user agents that don't correct for this on the fly.
+
+ shockwave-flash
+
+ A filter for shockwave haters. As the name suggests, this filter
+ strips code out of web pages that is used to embed shockwave flash
+ objects.
+
+ quicktime-kioskmode
+
+ Change HTML code that embeds Quicktime objects so that kioskmode,
+ which prevents saving, is disabled.
+
+ fun
+
+ Text replacements for subversive browsing fun. Make fun of your
+ favorite Monopolist or play buzzword bingo.
+
+ crude-parental
+
+ A demonstration-only filter that shows how Privoxy can be used to
+ delete web content on a keyword basis.
+
+ ie-exploits
+
+ An experimental collection of text replacements to disable
+ malicious HTML and JavaScript code that exploits known security
+ holes in Internet Explorer.
+
+ Presently, it only protects against Nimda and a cross-site
+ scripting bug, and would need active maintenance to provide more
+ substantial protection.
+
+ site-specifics
+
+ Some web sites have very specific problems, the cure for which
+ doesn't apply anywhere else, or could even cause damage on other
+ sites.
+
+ This is a collection of such site-specific cures which should only
+ be applied to the sites they were intended for, which is what the
+ supplied default.action file does. Users shouldn't need to change
+ anything regarding this filter.
+
+ google
+
+ A CSS based block for Google text ads. Also removes a width
+ limitation and the toolbar advertisement.
+
+ yahoo
+
+ Another CSS based block, this time for Yahoo text ads. And removes
+ a width limitation as well.
+
+ msn
+
+ Another CSS based block, this time for MSN text ads. And removes
+ tracking URLs, as well as a width limitation.
+
+ blogspot
+
+ Cleans up some Blogspot blogs. Read the fine print before using
+ this one!
+
+ This filter also intentionally removes some navigation stuff and
+ sets the page width to 100%. As a result, some rounded "corners"
+ would appear to early or not at all and as fixing this would
+ require a browser that understands background-size (CSS3), they
+ are removed instead.
+
+ xml-to-html
+
+ Server-header filter to change the Content-Type from xml to html.
+
+ html-to-xml
+
+ Server-header filter to change the Content-Type from html to xml.
+
+ no-ping
+
+ Removes the non-standard ping attribute from anchor and area HTML
+ tags.
+
+ hide-tor-exit-notation
+
+ Client-header filter to remove the Tor exit node notation found in
+ Host and Referer headers.
+
+ If Privoxy and Tor are chained and Privoxy is configured to use
+ socks4a, one can use "http://www.example.org.foobar.exit/" to
+ access the host "www.example.org" through the Tor exit node
+ "foobar".
+
+ As the HTTP client isn't aware of this notation, it treats the
+ whole string "www.example.org.foobar.exit" as host and uses it for
+ the "Host" and "Referer" headers. From the server's point of view
+ the resulting headers are invalid and can cause problems.
+
+ An invalid "Referer" header can trigger "hot-linking" protections,
+ an invalid "Host" header will make it impossible for the server to
+ find the right vhost (several domains hosted on the same IP
+ address).
+
+ This client-header filter removes the "foo.exit" part in those
+ headers to prevent the mentioned problems. Note that it only
+ modifies the HTTP headers, it doesn't make it impossible for the
+ server to detect your Tor exit node based on the IP address the
+ request is coming from.
+
+ --------------------------------------------------------------------------
+
+10. Privoxy's Template Files
+
+ All Privoxy built-in pages, i.e. error pages such as the "404 - No Such
+ Domain" error page, the "BLOCKED" page and all pages of its web-based user
+ interface, are generated from templates. (Privoxy must be running for the
+ above links to work as intended.)
+
+ These templates are stored in a subdirectory of the configuration
+ directory called templates. On Unixish platforms, this is typically
+ /etc/privoxy/templates/.
+
+ The templates are basically normal HTML files, but with place-holders
+ (called symbols or exports), which Privoxy fills at run time. It is
+ possible to edit the templates with a normal text editor, should you want
+ to customize them. (Not recommended for the casual user). Should you
+ create your own custom templates, you should use the config setting
+ templdir to specify an alternate location, so your templates do not get
+ overwritten during upgrades.
+
+ Note that just like in configuration files, lines starting with # are
+ ignored when the templates are filled in.
+
+ The place-holders are of the form @name@, and you will find a list of
+ available symbols, which vary from template to template, in the comments
+ at the start of each file. Note that these comments are not always
+ accurate, and that it's probably best to look at the existing HTML code to
+ find out which symbols are supported and what they are filled in with.
+
+ A special application of this substitution mechanism is to make whole
+ blocks of HTML code disappear when a specific symbol is set. We use this
+ for many purposes, one of them being to include the beta warning in all
+ our user interface (CGI) pages when Privoxy is in an alpha or beta
+ development stage:
+
+ <!-- @if-unstable-start -->
+
+ ... beta warning HTML code goes here ...
+
+ <!-- if-unstable-end@ -->
+
+ If the "unstable" symbol is set, everything in between and including
+ @if-unstable-start and if-unstable-end@ will disappear, leaving nothing
+ but an empty comment:
+
+ <!-- -->
+
+ There's also an if-then-else construct and an #include mechanism, but
+ you'll sure find out if you are inclined to edit the templates ;-)
+
+ All templates refer to a style located at
+ http://config.privoxy.org/send-stylesheet. This is, of course, locally
+ served by Privoxy and the source for it can be found and edited in the
+ cgi-style.css template.
+
+ --------------------------------------------------------------------------
11. Contacting the Developers, Bug Reporting and Feature Requests
-We value your feedback. However, to provide you with the best support, please
-note the following sections.
+ We value your feedback. In fact, we rely on it to improve Privoxy and its
+ configuration. However, please note the following hints, so we can provide
+ you with the best support:
+
+ --------------------------------------------------------------------------
+
+ 11.1. Get Support
+
+ For casual users, our support forum at SourceForge is probably best
+ suited: http://sourceforge.net/tracker/?group_id=11118&atid=211118
+
+ All users are of course welcome to discuss their issues on the users
+ mailing list, where the developers also hang around.
+
+ Note that the Privoxy mailing lists are moderated. Posts from unsubscribed
+ addresses have to be accepted manually by a moderator. This may cause a
+ delay of several days and if you use a subject that doesn't clearly
+ mention Privoxy or one of its features, your message may be accidentally
+ discarded as spam.
--------------------------------------------------------------------------------
+ If you aren't subscribed, you should therefore spend a few seconds to come
+ up with a proper subject. Additionally you should make it clear that you
+ want to get CC'd. Otherwise some responses will be directed to the mailing
+ list only, and you won't see them.
-11.1. Get Support
+ --------------------------------------------------------------------------
-To get support, use the Sourceforge Support Forum:
+ 11.2. Reporting Problems
- http://sourceforge.net/tracker/?group_id=11118&atid=211118
+ "Problems" for our purposes, come in two forms:
--------------------------------------------------------------------------------
+ * Configuration issues, such as ads that slip through, or sites that
+ don't function properly due to one Privoxy "action" or another being
+ turned "on".
-11.2. Report bugs
+ * "Bugs" in the programming code that makes up Privoxy, such as that
+ might cause a crash.
-To submit bugs, use the Sourceforge Bug Forum:
+ --------------------------------------------------------------------------
- http://sourceforge.net/tracker/?group_id=11118&atid=111118.
+ 11.2.1. Reporting Ads or Other Configuration Problems
-Make sure that the bug has not already been submitted. Please try to verify
-that it is a Privoxy bug, and not a browser or site bug first. If you are using
-your own custom configuration, please try the stock configs to see if the
-problem is a configuration related bug. And if not using the latest development
-snapshot, please try the latest one. Or even better, CVS sources. Please be
-sure to include the Privoxy version, platform, browser, any pertinent log data,
-any other relevant details (please be specific) and, if possible, some way to
-reproduce the bug.
+ Please send feedback on ads that slipped through, innocent images that
+ were blocked, sites that don't work properly, and other configuration
+ related problem of default.action file, to
+ http://sourceforge.net/tracker/?group_id=11118&atid=460288, the Actions
+ File Tracker.
--------------------------------------------------------------------------------
+ New, improved default.action files may occasionally be made available
+ based on your feedback. These will be announced on the ijbswa-announce
+ list and available from our the files section of our project page.
-11.3. Request new features
+ --------------------------------------------------------------------------
-To submit ideas on new features, use the Sourceforge feature request forum:
+ 11.2.2. Reporting Bugs
- http://sourceforge.net/tracker/?atid=361118&group_id=11118&func=browse.
+ Please report all bugs through our bug tracker:
+ http://sourceforge.net/tracker/?group_id=11118&atid=111118.
--------------------------------------------------------------------------------
+ Before doing so, please make sure that the bug has not already been
+ submitted and observe the additional hints at the top of the submit form.
+ If already submitted, please feel free to add any info to the original
+ report that might help to solve the issue.
-11.4. Report ads or other filter problems
+ Please try to verify that it is a Privoxy bug, and not a browser or site
+ bug or documented behaviour that just happens to be different than what
+ you expected. If unsure, try toggling off Privoxy, and see if the problem
+ persists.
-You can also send feedback on websites that Privoxy has problems with. Please
-bookmark the following link: "Privoxy - Submit Filter Feedback". Once you surf
-to a page with problems, use the bookmark to send us feedback. We will look
-into the issue as soon as possible.
+ If you are using your own custom configuration, please try the stock
+ configs to see if the problem is configuration related. If you're having
+ problems with a feature that is disabled by default, please ask around on
+ the mailing list if others can reproduce the problem.
-New, improved default.action files will occasionally be made available based on
-your feedback. These will be announced on the ijbswa-announce list.
+ If you aren't using the latest Privoxy version, the bug may have been
+ found and fixed in the meantime. We would appreciate if you could take the
+ time to upgrade to the latest version (or even the latest CVS snapshot)
+ and verify that your bug still exists.
--------------------------------------------------------------------------------
+ Please be sure to provide the following information:
-11.5. Other
+ * The exact Privoxy version you are using (if you got the source from
+ CVS, please also provide the source code revisions as shown in
+ http://config.privoxy.org/show-version).
-For any other issues, feel free to use the mailing lists:
-
- http://sourceforge.net/mail/?group_id=11118.
+ * The operating system and versions you run Privoxy on, (e.g. Windows XP
+ SP2), if you are using a Unix flavor, sending the output of "uname -a"
+ should do, in case of GNU/Linux, please also name the distribution.
-Anyone interested in actively participating in development and related
-discussions can also join the appropriate mailing list. Archives are available,
-too. See the page on Sourceforge.
+ * The name, platform, and version of the browser you were using (e.g.
+ Internet Explorer v5.5 for Mac).
--------------------------------------------------------------------------------
+ * The URL where the problem occurred, or some way for us to duplicate
+ the problem (e.g. http://somesite.example.com/?somethingelse=123).
-12. Copyright, License and History
+ * Whether your version of Privoxy is one supplied by the Privoxy
+ developers via SourceForge, or if you got your copy somewhere else.
-12.1. Copyright
+ * Whether you are using Privoxy in tandem with another proxy such as
+ Tor. If so, please temporary disable the other proxy to see if the
+ symptoms change.
-Permission is granted to copy, distribute and/or modify this document under the
-terms of the GNU Free Documentation License, Version 1.1 or any later version
-published by the Free Software Foundation with no Invariant Sections, no
-Front-Cover Texts, and no Back-Cover Texts. A copy of the license can be found
-http://www.gnu.org/licenses/fdl.html.
+ * Whether you are using a personal firewall product. If so, does Privoxy
+ work without it?
--------------------------------------------------------------------------------
+ * Any other pertinent information to help identify the problem such as
+ config or log file excerpts (yes, you should have log file entries for
+ each action taken).
-12.2. License
+ You don't have to tell us your actual name when filing a problem report,
+ but please use a nickname so we can differentiate between your messages
+ and the ones entered by other "anonymous" users that may respond to your
+ request if they have the same problem or already found a solution.
-Privoxy 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.
+ Please also check the status of your request a few days after submitting
+ it, as we may request additional information. If you use a SF id, you
+ should automatically get a mail when someone responds to your request.
-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 the Free Software Foundation, Inc, 59 Temple Place - Suite
-330, Boston, MA 02111-1307, USA.
+ The appendix of the Privoxy User Manual also has helpful information on
+ understanding actions, and action debugging.
-You should have received a copy of the GNU General Public License along with
-this program; if not, write to the Free Software Foundation, Inc., 59 Temple
-Place, Suite 330, Boston, MA 02111-1307 USA.
+ --------------------------------------------------------------------------
--------------------------------------------------------------------------------
+ 11.3. Request New Features
-12.3. History
+ You are welcome to submit ideas on new features or other proposals for
+ improvement through our feature request tracker at
+ http://sourceforge.net/tracker/?atid=361118&group_id=11118.
-Privoxy is evolved, and derived from, the Internet Junkbuster, with many
-improvments and enhancements over the original.
+ --------------------------------------------------------------------------
-Junkbuster was originally written by Anonymous Coders and Junkbusters
-Corporation, and was released as free open-source software under the GNU GPL.
-Stefan Waldherr made many improvements, and started the SourceForge project
-Privoxy to rekindle development. There are now several active developers
-contributing. The last stable release of Junkbuster was v2.0.2, which has now
-grown whiskers ;-).
+ 11.4. Other
--------------------------------------------------------------------------------
+ For any other issues, feel free to use the mailing lists. Technically
+ interested users and people who wish to contribute to the project are also
+ welcome on the developers list! You can find an overview of all
+ Privoxy-related mailing lists, including list archives, at:
+ http://sourceforge.net/mail/?group_id=11118.
+
+ --------------------------------------------------------------------------
+
+12. Privoxy Copyright, License and History
+
+ Copyright (c) 2001-2008 by Privoxy Developers
+ <ijbswa-developers@lists.sourceforge.net>
+
+ Some source code is based on code Copyright (c) 1997 by Anonymous Coders
+ and Junkbusters, Inc. and licensed under the GNU General Public License.
+
+ --------------------------------------------------------------------------
+
+ 12.1. License
+
+ Privoxy is free software; you can redistribute it and/or modify it under
+ the terms of the GNU General Public License, version 2, as published by
+ the Free Software Foundation.
+
+ 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 the Free Software Foundation,
+ Inc, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
+
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the
+
+ Free Software
+ Foundation, Inc. 51 Franklin Street, Fifth Floor
+ Boston, MA 02110-1301
+ USA
+
+ --------------------------------------------------------------------------
+
+ 12.2. History
+
+ A long time ago, there was the Internet Junkbuster, by Anonymous Coders
+ and Junkbusters Corporation. This saved many users a lot of pain in the
+ early days of web advertising and user tracking.
+
+ But the web, its protocols and standards, and with it, the techniques for
+ forcing ads on users, give up autonomy over their browsing, and for
+ tracking them, keeps evolving. Unfortunately, the Internet Junkbuster did
+ not. Version 2.0.2, published in 1998, was (and is) the last official
+ release available from Junkbusters Corporation. Fortunately, it had been
+ released under the GNU GPL, which allowed further development by others.
+
+ So Stefan Waldherr started maintaining an improved version of the
+ software, to which eventually a number of people contributed patches. It
+ could already replace banners with a transparent image, and had a first
+ version of pop-up killing, but it was still very closely based on the
+ original, with all its limitations, such as the lack of HTTP/1.1 support,
+ flexible per-site configuration, or content modification. The last release
+ from this effort was version 2.0.2-10, published in 2000.
+
+ Then, some developers picked up the thread, and started turning the
+ software inside out, upside down, and then reassembled it, adding many new
+ features along the way.
+
+ The result of this is Privoxy, whose first stable version, 3.0, was
+ released August, 2002.
+
+ --------------------------------------------------------------------------
+
+ 12.3. Authors
+
+ Current Privoxy Team:
+
+ Fabian Keil, lead developer
+ David Schmidt, developer
+
+ Hal Burgiss
+ Gerry Murphy
+ Roland Rosenfeld
+ Jörg Strohmayer
+
+ Former Privoxy Team Members:
+
+ Johny Agotnes
+ Rodrigo Barbosa
+ Moritz Barsnick
+ Ian Cummings
+ Brian Dessent
+ Jon Foster
+ Karsten Hopp
+ Alexander Lazic
+ Daniel Leite
+ Gábor Lipták
+ Adam Lock
+ Guy Laroche
+ Mark Martinec
+ Justin McMurtry
+ Andreas Oesterhelt
+ Haroon Rafique
+ Georg Sauthoff
+ Thomas Steudten
+ Rodney Stromlund
+ Sviatoslav Sviridov
+ Sarantis Paskalis
+ Stefan Waldherr
+
+ Thanks to the many people who have tested Privoxy, reported bugs, provided
+ patches, made suggestions or contributed in some way. These include (in
+ alphabetical order):
+
+ Ken Arromdee
+ Devin Bayer
+ Gergely Bor
+ Reiner Buehl
+ Andrew J. Caines
+ Clifford Caoile
+ Frédéric Crozat
+ Michael T. Davis
+ Mattes Dolak
+ Peter E.
+ Florian Effenberger
+ Markus Elfring
+ Dean Gaudet
+ Stephen Gildea
+ Daniel Griscom
+ Felix Gröbert
+ Aaron Hamid
+ Darel Henman
+ Magnus Holmgren
+ Ralf Horstmann
+ Stefan Huehner
+ Peter Hyman
+ Derek Jennings
+ Petr Kadlec
+ David Laight
+ Bert van Leeuwen
+ Don Libes
+ Paul Lieverse
+ Toby Lyward
+ Wil Mahan
+ Jindrich Makovicka
+ David Mediavilla
+ Raphael Moll
+ Amuro Namie
+ Adam Piggott
+ Dan Price
+ Lee R.
+ Roberto Ragusa
+ Félix Rauch
+ Maynard Riley
+ Chung-chieh Shan
+ Spinor S.
+ Bart Schelstraete
+ Oliver Stoeneberg
+ Peter Thoenen
+ Martin Thomas
+ Song Weijia
+ Jörg Weinmann
+ Darren Wiebe
+ Bobby G. Vinyard
+ Anduin Withers
+ Oliver Yeoh
+ Jamie Zawinski
+
+ Privoxy is based in part on code originally developed by Junkbusters Corp.
+ and Anonymous Coders.
+
+ Privoxy heavily relies on Philip Hazel's PCRE.
+
+ The code to filter compressed content makes use of zlib which is written
+ by Jean-loup Gailly and Mark Adler.
+
+ On systems that lack snprintf(), Privoxy is using a version written by
+ Mark Martinec. On systems that lack strptime(), Privoxy is using the one
+ from the GNU C Library written by Ulrich Drepper.
+
+ --------------------------------------------------------------------------
13. See Also
-Other references and sites of interest to Privoxy users:
+ Other references and sites of interest to Privoxy users:
+
+ http://www.privoxy.org/, the Privoxy Home page.
-http://www.privoxy.org/, The Privoxy Home page.
+ http://www.privoxy.org/faq/, the Privoxy FAQ.
-http://sourceforge.net/projects/ijbswa, the Project Page for Privoxy on
-Sourceforge.
+ http://sourceforge.net/projects/ijbswa/, the Project Page for Privoxy on
+ SourceForge.
-http://p.p/, access Privoxy from your browser. Alternately, http://
-config.privoxy.org may work in some situations where the first does not.
+ http://config.privoxy.org/, the web-based user interface. Privoxy must be
+ running for this to work. Shortcut: http://p.p/
-http://p.p/, and select "Privoxy - Submit Filter Feedback" to submit "misses"
-to the developers.
+ http://sourceforge.net/tracker/?group_id=11118&atid=460288, to submit
+ "misses" and other configuration related suggestions to the developers.
-http://www.junkbusters.com/ht/en/cookies.html
+ http://www.junkbusters.com/ht/en/cookies.html, an explanation how cookies
+ are used to track web users.
-http://www.waldherr.org/junkbuster/
+ http://www.junkbusters.com/ijb.html, the original Internet Junkbuster.
-http://privacy.net/analyze/
+ http://privacy.net/, a useful site to check what information about you is
+ leaked while you browse the web.
-http://www.squid-cache.org/
+ http://www.squid-cache.org/, a popular caching proxy, which is often used
+ together with Privoxy.
-
+ http://www.pps.jussieu.fr/~jch/software/polipo/, Polipo is a caching proxy
+ with advanced features like pipelining, multiplexing and caching of
+ partial instances. In many setups it can be used as Squid replacement.
--------------------------------------------------------------------------------
+ http://tor.eff.org/, Tor can help anonymize web browsing, web publishing,
+ instant messaging, IRC, SSH, and other applications.
+
+ http://www.privoxy.org/developer-manual/, the Privoxy developer manual.
+
+ --------------------------------------------------------------------------
14. Appendix
-14.1. Regular Expressions
-
-Privoxy can use "regular expressions" in various config files. Assuming support
-for "pcre" (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.
-
-If you are reading this, you probably don't understand what "regular
-expressions" are, or what they can do. So this will be a very brief
-introduction only. A full explanation would require a book ;-)
-
-"Regular expressions" is a way of matching one character expression against
-another to see if it matches or not. One of the "expressions" 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 "meta-characters" 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.
-
-To make a simple analogy, we do something similar when we use wild-card
-characters when listing files with the dir command in DOS. *.* matches all
-filenames. The "special" character here is the asterisk which matches any and
-all characters. We can be more specific and use ? to match just individual
-characters. So "dir file?.text" would match "file1.txt", "file2.txt", etc. We
-are pattern matching, using a similar technique to "regular expressions"!
-
-Regular expressions do essentially the same thing, but are much, much more
-powerful. There are many more "special characters" and ways of building complex
-patterns however. Let's look at a few of the common ones, and then some
-examples:
-
-. - Matches any single character, e.g. "a", "A", "4", ":", or "@".
-
-? - The preceding character or expression is matched ZERO or ONE times. Either/
-or.
-
-+ - The preceding character or expression is matched ONE or MORE times.
-
-* - The preceding character or expression is matched ZERO or MORE times.
-
-\ - The "escape" character denotes that the following character should be taken
-literally. This is used where one of the special characters (e.g. ".") needs to
-be taken literally and not as a special meta-character. Example: "example
-\.com", makes sure the period is recognized only as a period (and not expanded
-to its meta-character meaning of any single character).
-
-[] - Characters enclosed in brackets will be matched if any of the enclosed
-characters are encountered. For instance, "[0-9]" matches any numeric digit
-(zero through nine). As an example, we can combine this with "+" to match any
-digit one of more times: "[0-9]+".
-
-() - parentheses are used to group a sub-expression, or multiple
-sub-expressions.
-
-| - The "bar" character works like an "or" conditional statement. A match is
-successful if the sub-expression on either side of "|" matches. As an example:
-"/(this|that) example/" uses grouping and the bar character and would match
-either "this example" or "that example", and nothing else.
-
-s/string1/string2/g - This is used to rewrite strings of text. "string1" is
-replaced by "string2" in this example. There must of course be a match on
-"string1" first.
-
-These are just some of the ones you are likely to use when matching URLs with
-Privoxy, 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:
-
-/.*/banners/.* - A simple example that uses the common combination of "." and "
-*" 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 (".*") another literal forward slash, the string "banners", another
-forward slash, and lastly another ".*". We are building a directory path here.
-This will match any file with the path that has a directory named "banners" in
-it. The ".*" 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: "/eye/hate/spammers/banners/annoy_me_please.gif", or just "/
-banners/annoying.html", or almost an infinite number of other possible
-combinations, just so it has "banners" in the path somewhere.
-
-A now something a little more complex:
-
-/.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward
-slashes again ("/"), so we are building another expression that is a file path
-statement. We have another ".*", so we are matching against any conceivable
-sub-path, just so it matches our expression. The only true literal that must
-match our pattern is adv, together with the forward slashes. What comes after
-the "adv" string is the interesting part.
-
-Remember the "?" means the preceding expression (either a literal character or
-anything grouped with "(...)" in this case) can exist or not, since this means
-either zero or one match. So "((er)?ts?|ertis(ing|ements?))" is optional, as
-are the individual sub-expressions: "(er)", "(ing|ements?)", and the "s". The "
-|" means "or". We have two of those. For instance, "(ing|ements?)", can expand
-to match either "ing" OR "ements?". What is being done here, is an attempt at
-matching as many variations of "advertisement", and similar, as possible. So
-this would expand to match just "adv", or "advert", or "adverts", or
-"advertising", or "advertisement", or "advertisements". You get the idea. But
-it would not match "advertizements" (with a "z"). We could fix that by changing
-our regular expression to: "/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/", which
-would then match either spelling.
-
-/.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward
-slashes. Anything in the square brackets "[]" can be matched. This is using
-"0-9" as a shorthand expression to mean any digit one through nine. It is the
-same as saying "0123456789". So any digit matches. The "+" 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: "(gif|jpe?g)". This includes a "|", so
-this needs to match the expression on either side of that bar character also. A
-simple "gif" on one side, and the other side will in turn match either "jpeg"
-or "jpg", since the "?" means the letter "e" 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 "advert", then one or
-more digits, and a "." (which is now a literal, and not a special character,
-since it is escaped with "\"), and lastly either "gif", or "jpeg", or "jpg".
-Some possible matches would include: "//advert1.jpg", "/nasty/ads/
-advert1234.gif", "/banners/from/hell/advert99.jpg". It would not match
-"advert1.gif" (no leading slash), or "/adverts232.jpg" (the expression does not
-include an "s"), or "/advert1.jsp" ("jsp" is not in the expression anywhere).
-
-s/microsoft(?!.com)/MicroSuck/i - This is a substitution. "MicroSuck" will
-replace any occurrence of "microsoft". The "i" at the end of the expression
-means ignore case. The "(?!.com)" means the match should fail if "microsoft" is
-followed by ".com". In other words, this acts like a "NOT" modifier. In case
-this is a hyperlink, we don't want to break it ;-).
-
-We are barely scratching the surface of regular expressions here so that you
-can understand the default Privoxy 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 :/
-
-More reading on Perl Compatible Regular expressions: http://www.perldoc.com/
-perl5.6/pod/perlre.html
-
--------------------------------------------------------------------------------
-
-14.2. Privoxy's Internal Pages
-
-Since Privoxy proxies each requested web page, it is easy for Privoxy to trap
-certain special URLs. In this way, we can talk directly to Privoxy, and see how
-it is configured, see how our rules are being applied, change these rules and
-other configuration options, and even turn Privoxy's filtering off, all with a
-web browser.
-
-The URLs listed below are the special ones that allow direct access to Privoxy.
-Of course, Privoxy must be running to access these. If not, you will get a
-friendly error message. Internet access is not necessary either.
-
- * Privoxy main page:
-
- http://config.privoxy.org/
-
- Alternately, this may be reached at http://p.p/, but this variation may not
- work as reliably as the above in some configurations.
-
- * Show information about the current configuration, including viewing and
- editing of actions files:
-
- http://config.privoxy.org/show-status
-
- * Show the source code version numbers:
-
- http://config.privoxy.org/show-version
-
- * Show the browser's request headers:
-
- http://config.privoxy.org/show-request
-
- * Show which actions apply to a URL and why:
-
- http://config.privoxy.org/show-url-info
-
- * Toggle Privoxy on or off. In this case, "Privoxy" continues to run, but
- only as a pass-through proxy, with no actions taking place:
-
- http://config.privoxy.org/toggle
-
- Short cuts. Turn off, then on:
-
- http://config.privoxy.org/toggle?set=disable
-
- http://config.privoxy.org/toggle?set=enable
-
-These may be bookmarked for quick reference. See next.
-
--------------------------------------------------------------------------------
-
-14.2.1. Bookmarklets
-
-Below are some "bookmarklets" to allow you to easily access a "mini" version of
-some of Privoxy's special pages. They are designed for MS Internet Explorer,
-but should work equally well in Netscape, Mozilla, and other browsers which
-support JavaScript. They are designed to run directly from your bookmarks - not
-by clicking the links below (although that should work for testing).
-
-To save them, right-click the link and choose "Add to Favorites" (IE) or "Add
-Bookmark" (Netscape). You will get a warning that the bookmark "may not be
-safe" - just click OK. Then you can run the Bookmarklet directly from your
-favorites/bookmarks. For even faster access, you can put them on the "Links"
-bar (IE) or the "Personal Toolbar" (Netscape), and run them with a single
-click.
-
- * Privoxy - Enable
-
- * Privoxy - Disable
-
- * Privoxy - Toggle Privoxy (Toggles between enabled and disabled)
-
- * Privoxy- View Status
-
- * Privoxy - Submit Filter Feedback
-
-Credit: The site which gave me the general idea for these bookmarklets is
-www.bookmarklets.com. They have more information about bookmarklets.
-
--------------------------------------------------------------------------------
-
-14.3. Chain of Events
-
-Let's take a quick look at the basic sequence of events when a web page is
-requested by your browser and Privoxy is on duty:
-
- * First, your web browser requests a web page. The browser knows to send the
- request to Privoxy, which will in turn, relay the request to the remote web
- server after passing the following tests:
-
- * Privoxy traps any request for its own internal CGI pages (e.g http://p.p/)
- and sends the CGI page back to the browser.
-
- * Next, Privoxy checks to see if the URL matches any "+block" patterns. If
- so, the URL is then blocked, and the remote web server will not be
- contacted. "+handle-as-image" is then checked and if it does not match, an
- HTML "BLOCKED" page is sent back. Otherwise, if it does match, an image is
- returned. The type of image depends on the setting of "+set-image-blocker"
- (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
-
- * Untrusted URLs are blocked. If URLs are being added to the trust file, then
- that is done.
-
- * If the URL pattern matches the "+fast-redirects" action, it is then
- processed. Unwanted parts of the requested URL are stripped.
-
- * Now the rest of the client browser's request headers are processed. If any
- of these match any of the relevant actions (e.g. "+hide-user-agent", etc.),
- headers are suppressed or forged as determined by these actions and their
- parameters.
-
- * Now the web server starts sending its response back (i.e. typically a web
- page and related data).
-
- * First, the server headers are read and processed to determine, among other
- things, the MIME type (document type) and encoding. The headers are then
- filtered as deterimed by the "+prevent-setting-cookies",
- "+session-cookies-only", and "+downgrade-http-version" actions.
-
- * If the "+kill-popups" action applies, and it is an HTML or JavaScript
- document, the popup-code in the response is filtered on-the-fly as it is
- received.
-
- * If a "+filter" or "+deanimate-gifs" action applies (and the document type
- fits the action), the rest of the page is read into memory (up to a
- configurable limit). Then the filter rules (from default.filter) are
- processed against the buffered content. Filters are applied in the order
- they are specified in the default.filter file. Animated GIFs, if present,
- are reduced to either the first or last frame, depending on the action
- setting.The entire page, which is now filtered, is then sent by Privoxy
- back to your browser.
-
- If neither "+filter" or "+deanimate-gifs" matches, then Privoxy passes the
- raw data through to the client browser as it becomes available.
-
- * As the browser receives the now (probably filtered) page content, it reads
- and then requests any URLs that may be embedded within the page source,
- e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
- frames), sounds, etc. For each of these objects, the browser issues a new
- request. And each such request is in turn processed as above. Note that a
- complex web page may have many such embedded URLs.
-
--------------------------------------------------------------------------------
-
-14.4. Anatomy of an Action
-
-The way Privoxy applies "actions" and "filters" to any given URL can be
-complex, and not always so easy to understand what is happening. And sometimes
-we need to be able to see just what Privoxy is doing. Especially, if something
-Privoxy is doing is causing us a problem inadvertently. It can be a little
-daunting to look at the actions and filters files themselves, since they tend
-to be filled with "regular expressions" whose consequences are not always so
-obvious.
-
-One quick test to see if Privoxy is causing a problem or not, is to disable it
-temporarily. This should be the first troubleshooting step. See the
-Bookmarklets section on a quick and easy way to do this (be sure to flush
-caches afterward!).
-
-Privoxy also provides the http://config.privoxy.org/show-url-info page that can
-show us very specifically how actions are being applied to any given URL. This
-is a big help for troubleshooting.
-
-First, enter one URL (or partial URL) at the prompt, and then Privoxy will tell
-us how the current configuration will handle it. This will not help with
-filtering effects (i.e. the "+filter" action) from the default.filter file
-since this is handled very differently and not so easy to trap! It also will
-not tell you about any other URLs that may be embedded within the URL you are
-testing. For instance, images such as ads are expressed as URLs within the raw
-page source of HTML pages. So you will only get info for the actual URL that is
-pasted into the prompt area -- not any sub-URLs. If you want to know about
-embedded URLs like ads, you will have to dig those out of the HTML source. Use
-your browser's "View Page Source" option for this. Or right click on the ad,
-and grab the URL.
-
-Let's try an example, google.com, and look at it one section at a time:
-
- Matches for http://google.com:
-
---- File standard ---
-(no matches in this file)
-
---- File default ---
-
-{ -add-header -block +deanimate-gifs{last} -downgrade-http-version +fast-redirects
- -filter{popups} -filter{fun} -filter{shockwave-flash} -filter{crude-parental}
- +filter{html-annoyances} +filter{js-annoyances} +filter{content-cookies}
- +filter{webbugs} +filter{refresh-tags} +filter{nimda} +filter{banners-by-size}
- +hide-forwarded-for-headers +hide-from-header{block} +hide-referer{forge}
- -hide-user-agent -handle-as-image +set-image-blocker{pattern} -limit-connect
- +prevent-compression +session-cookies-only -prevent-reading-cookies
- -prevent-setting-cookies -kill-popups -send-vanilla-wafer -send-wafer }
-/
-
- { -session-cookies-only }
- .google.com
-
- { -fast-redirects }
- .google.com
-
---- File user ---
-(no matches in this file)
-
-This tells us how we have defined our "actions", and which ones match for our
-example, "google.com". The first listing is any matches for the standard.action
-file. No hits at all here on "standard". Then next is "default", or our
-default.action file. The large, multi-line listing, is how the actions are set
-to match for all URLs, i.e. our default settings. If you look at your "actions"
-file, this would be the section just below the "aliases" section near the top.
-This will apply to all URLs as signified by the single forward slash at the end
-of the listing -- "/".
-
-But we can define additional actions that would be exceptions to these general
-rules, and then list specific URLs (or patterns) that these exceptions would
-apply to. Last match wins. Just below this then are two explicit matches for
-".google.com". The first is negating our previous cookie setting, which was for
-"+session-cookies-only" (i.e. not persistent). So we will allow persistent
-cookies for google. The second turns off any "+fast-redirects" action, allowing
-this to take place unmolested. Note that there is a leading dot here --
-".google.com". This will match any hosts and sub-domains, in the google.com
-domain also, such as "www.google.com". So, apparently, we have these two
-actions defined somewhere in the lower part of our default.action file, and
-"google.com" is referenced somewhere in these latter sections.
-
-Then, for our user.action file, we again have no hits.
-
-And finally we pull it all together in the bottom section and summarize how
-Privoxy is applying all its "actions" to "google.com":
-
- Final results:
- -add-header -block +deanimate-gifs{last} -downgrade-http-version -fast-redirects
- -filter{popups} -filter{fun} -filter{shockwave-flash} -filter{crude-parental}
- +filter{html-annoyances} +filter{js-annoyances} +filter{content-cookies}
- +filter{webbugs} +filter{refresh-tags} +filter{nimda} +filter{banners-by-size}
- +hide-forwarded-for-headers +hide-from-header{block} +hide-referer{forge}
- -hide-user-agent -handle-as-image +set-image-blocker{pattern} -limit-connect
- +prevent-compression -session-cookies-only -prevent-reading-cookies
- -prevent-setting-cookies -kill-popups -send-vanilla-wafer -send-wafer
-
-Notice the only difference here to the previous listing, is to "fast-redirects"
-and "session-cookies-only".
-
-Now another example, "ad.doubleclick.net":
-
- { +block +handle-as-image }
- .ad.doubleclick.net
-
- { +block +handle-as-image }
- ad*.
-
- { +block +handle-as-image }
- .doubleclick.net
-
-We'll just show the interesting part here, the explicit matches. It is matched
-three different times. Each as an "+block +handle-as-image", which is the
-expanded form of one of our aliases that had been defined as: "+imageblock". (
-"Aliases" are defined in the first section of the actions file and typically
-used to combine more than one action.)
-
-Any one of these would have done the trick and blocked this as an unwanted
-image. This is unnecessarily redundant since the last case effectively would
-also cover the first. No point in taking chances with these guys though ;-)
-Note that if you want an ad or obnoxious URL to be invisible, it should be
-defined as "ad.doubleclick.net" is done here -- as both a "+block" and an
-"+handle-as-image". The custom alias "+imageblock" just simplifies the process
-and make it more readable.
-
-One last example. Let's try "http://www.rhapsodyk.net/adsl/HOWTO/". This one is
-giving us problems. We are getting a blank page. Hmmm...
-
- Matches for http://www.rhapsodyk.net/adsl/HOWTO/:
-
- { -add-header -block +deanimate-gifs -downgrade-http-version +fast-redirects
- +filter{html-annoyances} +filter{js-annoyances} +filter{kill-popups}
- +filter{webbugs} +filter{nimda} +filter{banners-by-size} +filter{hal}
- +filter{fun} +hide-forwarded-for-headers +hide-from-header{block}
- +hide-referer{forge} -hide-user-agent -handle-as-image +set-image-blocker{blank}
- +prevent-compression +session-cookies-only -prevent-setting-cookies
- -prevent-reading-cookies +kill-popups -send-vanilla-wafer -send-wafer }
- /
-
- { +block +handle-as-image }
- /ads
-
-Ooops, the "/adsl/" is matching "/ads"! But we did not want this at all! Now we
-see why we get the blank page. We could now add a new action below this that
-explicitly does not block ("{-block}") paths with "adsl". There are various
-ways to handle such exceptions. Example:
-
- { -block }
- /adsl
-
-Now the page displays ;-) Be sure to flush your browser's caches when making
-such changes. Or, try using Shift+Reload.
-
-But now what about a situation where we get no explicit matches like we did
-with:
-
- { +block +handle-as-image }
- /ads
-
-That actually was very telling and pointed us quickly to where the problem was.
-If you don't get this kind of match, then it means one of the default rules in
-the first section is causing the problem. This would require some guesswork,
-and maybe a little trial and error to isolate the offending rule. One likely
-cause would be one of the "{+filter}" actions. Try adding the URL for the site
-to one of aliases that turn off "+filter":
-
- {shop}
- .quietpc.com
- .worldpay.com # for quietpc.com
- .jungle.com
- .scan.co.uk
- .forbes.com
-
-"{shop}" is an "alias" that expands to "{ -filter -session-cookies-only }". Or
-you could do your own exception to negate filtering:
-
- {-filter}
- .forbes.com
-
-This would probably be most appropriately put in user.action, for local site
-exceptions.
-
-"{fragile}" is an alias that disables most actions. This can be used as a last
-resort for problem sites. Remember to flush caches! If this still does not
-work, you will have to go through the remaining actions one by one to find
-which one(s) is causing the problem.
+ 14.1. Regular Expressions
+
+ Privoxy uses Perl-style "regular expressions" in its actions files and
+ filter file, through the PCRE and PCRS libraries.
+
+ If you are reading this, you probably don't understand what "regular
+ expressions" are, or what they can do. So this will be a very brief
+ introduction only. A full explanation would require a book ;-)
+
+ Regular expressions provide a language to describe patterns that can be
+ run against strings of characters (letter, numbers, etc), to see if they
+ match the string or not. The patterns are themselves (sometimes complex)
+ strings of literal characters, combined with wild-cards, and other special
+ characters, called meta-characters. The "meta-characters" have special
+ meanings and are used to build complex patterns to be matched against.
+ Perl Compatible Regular Expressions are an especially convenient "dialect"
+ of the regular expression language.
+
+ To make a simple analogy, we do something similar when we use wild-card
+ characters when listing files with the dir command in DOS. *.* matches all
+ filenames. The "special" character here is the asterisk which matches any
+ and all characters. We can be more specific and use ? to match just
+ individual characters. So "dir file?.text" would match "file1.txt",
+ "file2.txt", etc. We are pattern matching, using a similar technique to
+ "regular expressions"!
+
+ Regular expressions do essentially the same thing, but are much, much more
+ powerful. There are many more "special characters" and ways of building
+ complex patterns however. Let's look at a few of the common ones, and then
+ some examples:
+
+ . - Matches any single character, e.g. "a", "A", "4", ":", or "@".
+
+ ? - The preceding character or expression is matched ZERO or ONE times.
+ Either/or.
+
+ + - The preceding character or expression is matched ONE or MORE times.
+
+ * - The preceding character or expression is matched ZERO or MORE times.
+
+ \ - The "escape" character denotes that the following character should be
+ taken literally. This is used where one of the special characters (e.g.
+ ".") needs to be taken literally and not as a special meta-character.
+ Example: "example\.com", makes sure the period is recognized only as a
+ period (and not expanded to its meta-character meaning of any single
+ character).
+
+ [ ] - Characters enclosed in brackets will be matched if any of the
+ enclosed characters are encountered. For instance, "[0-9]" matches any
+ numeric digit (zero through nine). As an example, we can combine this with
+ "+" to match any digit one of more times: "[0-9]+".
+
+ ( ) - parentheses are used to group a sub-expression, or multiple
+ sub-expressions.
+
+ | - The "bar" character works like an "or" conditional statement. A match
+ is successful if the sub-expression on either side of "|" matches. As an
+ example: "/(this|that) example/" uses grouping and the bar character and
+ would match either "this example" or "that example", and nothing else.
+
+ These are just some of the ones you are likely to use when matching URLs
+ with Privoxy, 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:
+
+ /.*/banners/.* - A simple example that uses the common combination of "."
+ and "*" 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 (".*") another literal forward slash, the string
+ "banners", another forward slash, and lastly another ".*". We are building
+ a directory path here. This will match any file with the path that has a
+ directory named "banners" in it. The ".*" 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:
+ "/eye/hate/spammers/banners/annoy_me_please.gif", or just
+ "/banners/annoying.html", or almost an infinite number of other possible
+ combinations, just so it has "banners" in the path somewhere.
+
+ And now something a little more complex:
+
+ /.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward
+ slashes again ("/"), so we are building another expression that is a file
+ path statement. We have another ".*", so we are matching against any
+ conceivable sub-path, just so it matches our expression. The only true
+ literal that must match our pattern is adv, together with the forward
+ slashes. What comes after the "adv" string is the interesting part.
+
+ Remember the "?" means the preceding expression (either a literal
+ character or anything grouped with "(...)" in this case) can exist or not,
+ since this means either zero or one match. So
+ "((er)?ts?|ertis(ing|ements?))" is optional, as are the individual
+ sub-expressions: "(er)", "(ing|ements?)", and the "s". The "|" means "or".
+ We have two of those. For instance, "(ing|ements?)", can expand to match
+ either "ing" OR "ements?". What is being done here, is an attempt at
+ matching as many variations of "advertisement", and similar, as possible.
+ So this would expand to match just "adv", or "advert", or "adverts", or
+ "advertising", or "advertisement", or "advertisements". You get the idea.
+ But it would not match "advertizements" (with a "z"). We could fix that by
+ changing our regular expression to:
+ "/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/", which would then match
+ either spelling.
+
+ /.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward
+ slashes. Anything in the square brackets "[ ]" can be matched. This is
+ using "0-9" as a shorthand expression to mean any digit one through nine.
+ It is the same as saying "0123456789". So any digit matches. The "+" 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:
+ "(gif|jpe?g)". This includes a "|", so this needs to match the expression
+ on either side of that bar character also. A simple "gif" on one side, and
+ the other side will in turn match either "jpeg" or "jpg", since the "?"
+ means the letter "e" 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 "advert", then one or more
+ digits, and a "." (which is now a literal, and not a special character,
+ since it is escaped with "\"), and lastly either "gif", or "jpeg", or
+ "jpg". Some possible matches would include: "//advert1.jpg",
+ "/nasty/ads/advert1234.gif", "/banners/from/hell/advert99.jpg". It would
+ not match "advert1.gif" (no leading slash), or "/adverts232.jpg" (the
+ expression does not include an "s"), or "/advert1.jsp" ("jsp" is not in
+ the expression anywhere).
+
+ We are barely scratching the surface of regular expressions here so that
+ you can understand the default Privoxy 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 :/
+
+ More reading on Perl Compatible Regular expressions:
+ http://perldoc.perl.org/perlre.html
+
+ For information on regular expression based substitutions and their
+ applications in filters, please see the filter file tutorial in this
+ manual.
+
+ --------------------------------------------------------------------------
+
+ 14.2. Privoxy's Internal Pages
+
+ Since Privoxy proxies each requested web page, it is easy for Privoxy to
+ trap certain special URLs. In this way, we can talk directly to Privoxy,
+ and see how it is configured, see how our rules are being applied, change
+ these rules and other configuration options, and even turn Privoxy's
+ filtering off, all with a web browser.
+
+ The URLs listed below are the special ones that allow direct access to
+ Privoxy. Of course, Privoxy must be running to access these. If not, you
+ will get a friendly error message. Internet access is not necessary
+ either.
+
+ * Privoxy main page:
+
+ http://config.privoxy.org/
+
+ There is a shortcut: http://p.p/ (But it doesn't provide a fall-back
+ to a real page, in case the request is not sent through Privoxy)
+
+ * Show information about the current configuration, including viewing
+ and editing of actions files:
+
+ http://config.privoxy.org/show-status
+
+ * Show the source code version numbers:
+
+ http://config.privoxy.org/show-version
+
+ * Show the browser's request headers:
+
+ http://config.privoxy.org/show-request
+
+ * Show which actions apply to a URL and why:
+
+ http://config.privoxy.org/show-url-info
+
+ * Toggle Privoxy on or off. This feature can be turned off/on in the
+ main config file. When toggled "off", "Privoxy" continues to run, but
+ only as a pass-through proxy, with no actions taking place:
+
+ http://config.privoxy.org/toggle
+
+ Short cuts. Turn off, then on:
+
+ http://config.privoxy.org/toggle?set=disable
+
+ http://config.privoxy.org/toggle?set=enable
+
+ These may be bookmarked for quick reference. See next.
+
+ --------------------------------------------------------------------------
+
+ 14.2.1. Bookmarklets
+
+ Below are some "bookmarklets" to allow you to easily access a "mini"
+ version of some of Privoxy's special pages. They are designed for MS
+ Internet Explorer, but should work equally well in Netscape, Mozilla, and
+ other browsers which support JavaScript. They are designed to run directly
+ from your bookmarks - not by clicking the links below (although that
+ should work for testing).
+
+ To save them, right-click the link and choose "Add to Favorites" (IE) or
+ "Add Bookmark" (Netscape). You will get a warning that the bookmark "may
+ not be safe" - just click OK. Then you can run the Bookmarklet directly
+ from your favorites/bookmarks. For even faster access, you can put them on
+ the "Links" bar (IE) or the "Personal Toolbar" (Netscape), and run them
+ with a single click.
+
+ * Privoxy - Enable
+
+ * Privoxy - Disable
+
+ * Privoxy - Toggle Privoxy (Toggles between enabled and disabled)
+
+ * Privoxy- View Status
+
+ * Privoxy - Why?
+
+ Credit: The site which gave us the general idea for these bookmarklets is
+ www.bookmarklets.com. They have more information about bookmarklets.
+
+ --------------------------------------------------------------------------
+
+ 14.3. Chain of Events
+
+ Let's take a quick look at how some of Privoxy's core features are
+ triggered, and the ensuing sequence of events when a web page is requested
+ by your browser:
+
+ * First, your web browser requests a web page. The browser knows to send
+ the request to Privoxy, which will in turn, relay the request to the
+ remote web server after passing the following tests:
+
+ * Privoxy traps any request for its own internal CGI pages (e.g
+ http://p.p/) and sends the CGI page back to the browser.
+
+ * Next, Privoxy checks to see if the URL matches any "+block" patterns.
+ If so, the URL is then blocked, and the remote web server will not be
+ contacted. "+handle-as-image" and "+handle-as-empty-document" are then
+ checked, and if there is no match, an HTML "BLOCKED" page is sent back
+ to the browser. Otherwise, if it does match, an image is returned for
+ the former, and an empty text document for the latter. The type of
+ image would depend on the setting of "+set-image-blocker" (blank,
+ checkerboard pattern, or an HTTP redirect to an image elsewhere).
+
+ * Untrusted URLs are blocked. If URLs are being added to the trust file,
+ then that is done.
+
+ * If the URL pattern matches the "+fast-redirects" action, it is then
+ processed. Unwanted parts of the requested URL are stripped.
+
+ * Now the rest of the client browser's request headers are processed. If
+ any of these match any of the relevant actions (e.g.
+ "+hide-user-agent", etc.), headers are suppressed or forged as
+ determined by these actions and their parameters.
+
+ * Now the web server starts sending its response back (i.e. typically a
+ web page).
+
+ * First, the server headers are read and processed to determine, among
+ other things, the MIME type (document type) and encoding. The headers
+ are then filtered as determined by the "+crunch-incoming-cookies",
+ "+session-cookies-only", and "+downgrade-http-version" actions.
+
+ * If the "+kill-popups" action applies, and it is an HTML or JavaScript
+ document, the popup-code in the response is filtered on-the-fly as it
+ is received.
+ * If any "+filter" action or "+deanimate-gifs" action applies (and the
+ document type fits the action), the rest of the page is read into
+ memory (up to a configurable limit). Then the filter rules (from
+ default.filter and any other filter files) are processed against the
+ buffered content. Filters are applied in the order they are specified
+ in one of the filter files. Animated GIFs, if present, are reduced to
+ either the first or last frame, depending on the action setting.The
+ entire page, which is now filtered, is then sent by Privoxy back to
+ your browser.
+
+ If neither a "+filter" action or "+deanimate-gifs" matches, then
+ Privoxy passes the raw data through to the client browser as it
+ becomes available.
+
+ * As the browser receives the now (possibly filtered) page content, it
+ reads and then requests any URLs that may be embedded within the page
+ source, e.g. ad images, stylesheets, JavaScript, other HTML documents
+ (e.g. frames), sounds, etc. For each of these objects, the browser
+ issues a separate request (this is easily viewable in Privoxy's logs).
+ And each such request is in turn processed just as above. Note that a
+ complex web page will have many, many such embedded URLs. If these
+ secondary requests are to a different server, then quite possibly a
+ very differing set of actions is triggered.
+
+ NOTE: This is somewhat of a simplistic overview of what happens with each
+ URL request. For the sake of brevity and simplicity, we have focused on
+ Privoxy's core features only.
+
+ --------------------------------------------------------------------------
+
+ 14.4. Troubleshooting: Anatomy of an Action
+
+ The way Privoxy applies actions and filters to any given URL can be
+ complex, and not always so easy to understand what is happening. And
+ sometimes we need to be able to see just what Privoxy is doing.
+ Especially, if something Privoxy is doing is causing us a problem
+ inadvertently. It can be a little daunting to look at the actions and
+ filters files themselves, since they tend to be filled with regular
+ expressions whose consequences are not always so obvious.
+
+ One quick test to see if Privoxy is causing a problem or not, is to
+ disable it temporarily. This should be the first troubleshooting step. See
+ the Bookmarklets section on a quick and easy way to do this (be sure to
+ flush caches afterward!). Looking at the logs is a good idea too. (Note
+ that both the toggle feature and logging are enabled via config file
+ settings, and may need to be turned "on".)
+
+ Another easy troubleshooting step to try is if you have done any
+ customization of your installation, revert back to the installed defaults
+ and see if that helps. There are times the developers get complaints about
+ one thing or another, and the problem is more related to a customized
+ configuration issue.
+
+ Privoxy also provides the http://config.privoxy.org/show-url-info page
+ that can show us very specifically how actions are being applied to any
+ given URL. This is a big help for troubleshooting.
+
+ First, enter one URL (or partial URL) at the prompt, and then Privoxy will
+ tell us how the current configuration will handle it. This will not help
+ with filtering effects (i.e. the "+filter" action) from one of the filter
+ files since this is handled very differently and not so easy to trap! It
+ also will not tell you about any other URLs that may be embedded within
+ the URL you are testing. For instance, images such as ads are expressed as
+ URLs within the raw page source of HTML pages. So you will only get info
+ for the actual URL that is pasted into the prompt area -- not any
+ sub-URLs. If you want to know about embedded URLs like ads, you will have
+ to dig those out of the HTML source. Use your browser's "View Page Source"
+ option for this. Or right click on the ad, and grab the URL.
+
+ Let's try an example, google.com, and look at it one section at a time in
+ a sample configuration (your real configuration may vary):
+
+ Matches for http://www.google.com:
+
+ In file: default.action [ View ] [ Edit ]
+
+ {+deanimate-gifs {last}
+ +fast-redirects {check-decoded-url}
+ +filter {refresh-tags}
+ +filter {img-reorder}
+ +filter {banners-by-size}
+ +filter {webbugs}
+ +filter {jumping-windows}
+ +filter {ie-exploits}
+ +hide-forwarded-for-headers
+ +hide-from-header {block}
+ +hide-referrer {forge}
+ +session-cookies-only
+ +set-image-blocker {pattern}
+ /
+
+ { -session-cookies-only }
+ .google.com
+
+ { -fast-redirects }
+ .google.com
+
+ In file: user.action [ View ] [ Edit ]
+ (no matches in this file)
+
+ This is telling us how we have defined our "actions", and which ones match
+ for our test case, "google.com". Displayed is all the actions that are
+ available to us. Remember, the + sign denotes "on". - denotes "off". So
+ some are "on" here, but many are "off". Each example we try may provide a
+ slightly different end result, depending on our configuration directives.
+
+ The first listing is for our default.action file. The large, multi-line
+ listing, is how the actions are set to match for all URLs, i.e. our
+ default settings. If you look at your "actions" file, this would be the
+ section just below the "aliases" section near the top. This will apply to
+ all URLs as signified by the single forward slash at the end of the
+ listing -- " / ".
+
+ But we have defined additional actions that would be exceptions to these
+ general rules, and then we list specific URLs (or patterns) that these
+ exceptions would apply to. Last match wins. Just below this then are two
+ explicit matches for ".google.com". The first is negating our previous
+ cookie setting, which was for "+session-cookies-only" (i.e. not
+ persistent). So we will allow persistent cookies for google, at least that
+ is how it is in this example. The second turns off any "+fast-redirects"
+ action, allowing this to take place unmolested. Note that there is a
+ leading dot here -- ".google.com". This will match any hosts and
+ sub-domains, in the google.com domain also, such as "www.google.com" or
+ "mail.google.com". But it would not match "www.google.de"! So, apparently,
+ we have these two actions defined as exceptions to the general rules at
+ the top somewhere in the lower part of our default.action file, and
+ "google.com" is referenced somewhere in these latter sections.
+
+ Then, for our user.action file, we again have no hits. So there is nothing
+ google-specific that we might have added to our own, local configuration.
+ If there was, those actions would over-rule any actions from previously
+ processed files, such as default.action. user.action typically has the
+ last word. This is the best place to put hard and fast exceptions,
+
+ And finally we pull it all together in the bottom section and summarize
+ how Privoxy is applying all its "actions" to "google.com":
+
+ Final results:
+
+ -add-header
+ -block
+ -client-header-filter{hide-tor-exit-notation}
+ -content-type-overwrite
+ -crunch-client-header
+ -crunch-if-none-match
+ -crunch-incoming-cookies
+ -crunch-outgoing-cookies
+ -crunch-server-header
+ +deanimate-gifs {last}
+ -downgrade-http-version
+ -fast-redirects
+ -filter {js-events}
+ -filter {content-cookies}
+ -filter {all-popups}
+ -filter {banners-by-link}
+ -filter {tiny-textforms}
+ -filter {frameset-borders}
+ -filter {demoronizer}
+ -filter {shockwave-flash}
+ -filter {quicktime-kioskmode}
+ -filter {fun}
+ -filter {crude-parental}
+ -filter {site-specifics}
+ -filter {js-annoyances}
+ -filter {html-annoyances}
+ +filter {refresh-tags}
+ -filter {unsolicited-popups}
+ +filter {img-reorder}
+ +filter {banners-by-size}
+ +filter {webbugs}
+ +filter {jumping-windows}
+ +filter {ie-exploits}
+ -filter {google}
+ -filter {yahoo}
+ -filter {msn}
+ -filter {blogspot}
+ -filter {no-ping}
+ -force-text-mode
+ -handle-as-empty-document
+ -handle-as-image
+ -hide-accept-language
+ -hide-content-disposition
+ +hide-forwarded-for-headers
+ +hide-from-header {block}
+ -hide-if-modified-since
+ +hide-referrer {forge}
+ -hide-user-agent
+ -inspect-jpegs
+ -kill-popups
+ -limit-connect
+ -overwrite-last-modified
+ -prevent-compression
+ -redirect
+ -send-vanilla-wafer
+ -send-wafer
+ -server-header-filter{xml-to-html}
+ -server-header-filter{html-to-xml}
+ -session-cookies-only
+ +set-image-blocker {pattern}
+ -treat-forbidden-connects-like-blocks
+
+ Notice the only difference here to the previous listing, is to
+ "fast-redirects" and "session-cookies-only", which are activated
+ specifically for this site in our configuration, and thus show in the
+ "Final Results".
+
+ Now another example, "ad.doubleclick.net":
+
+ { +block }
+ ad*.
+
+ { +block }
+ .ad.
+
+ { +block +handle-as-image }
+ .[a-vx-z]*.doubleclick.net
+
+ We'll just show the interesting part here - the explicit matches. It is
+ matched three different times. Two "+block" sections, and a "+block
+ +handle-as-image", which is the expanded form of one of our aliases that
+ had been defined as: "+block-as-image". ("Aliases" are defined in the
+ first section of the actions file and typically used to combine more than
+ one action.)
+
+ Any one of these would have done the trick and blocked this as an unwanted
+ image. This is unnecessarily redundant since the last case effectively
+ would also cover the first. No point in taking chances with these guys
+ though ;-) Note that if you want an ad or obnoxious URL to be invisible,
+ it should be defined as "ad.doubleclick.net" is done here -- as both a
+ "+block" and an "+handle-as-image". The custom alias "+block-as-image"
+ just simplifies the process and make it more readable.
+
+ One last example. Let's try "http://www.example.net/adsl/HOWTO/". This one
+ is giving us problems. We are getting a blank page. Hmmm ...
+
+ Matches for http://www.example.net/adsl/HOWTO/:
+
+ In file: default.action [ View ] [ Edit ]
+
+ {-add-header
+ -block
+ -client-header-filter{hide-tor-exit-notation}
+ -content-type-overwrite
+ -crunch-client-header
+ -crunch-if-none-match
+ -crunch-incoming-cookies
+ -crunch-outgoing-cookies
+ -crunch-server-header
+ +deanimate-gifs
+ -downgrade-http-version
+ +fast-redirects {check-decoded-url}
+ -filter {js-events}
+ -filter {content-cookies}
+ -filter {all-popups}
+ -filter {banners-by-link}
+ -filter {tiny-textforms}
+ -filter {frameset-borders}
+ -filter {demoronizer}
+ -filter {shockwave-flash}
+ -filter {quicktime-kioskmode}
+ -filter {fun}
+ -filter {crude-parental}
+ -filter {site-specifics}
+ -filter {js-annoyances}
+ -filter {html-annoyances}
+ +filter {refresh-tags}
+ -filter {unsolicited-popups}
+ +filter {img-reorder}
+ +filter {banners-by-size}
+ +filter {webbugs}
+ +filter {jumping-windows}
+ +filter {ie-exploits}
+ -filter {google}
+ -filter {yahoo}
+ -filter {msn}
+ -filter {blogspot}
+ -filter {no-ping}
+ -force-text-mode
+ -handle-as-empty-document
+ -handle-as-image
+ -hide-accept-language
+ -hide-content-disposition
+ +hide-forwarded-for-headers
+ +hide-from-header{block}
+ +hide-referer{forge}
+ -hide-user-agent
+ -inspect-jpegs
+ -kill-popups
+ -overwrite-last-modified
+ +prevent-compression
+ -redirect
+ -send-vanilla-wafer
+ -send-wafer
+ -server-header-filter{xml-to-html}
+ -server-header-filter{html-to-xml}
+ +session-cookies-only
+ +set-image-blocker{blank}
+ -treat-forbidden-connects-like-blocks }
+ /
+
+ { +block +handle-as-image }
+ /ads
+
+ Ooops, the "/adsl/" is matching "/ads" in our configuration! But we did
+ not want this at all! Now we see why we get the blank page. It is actually
+ triggering two different actions here, and the effects are aggregated so
+ that the URL is blocked, and Privoxy is told to treat the block as if it
+ were an image. But this is, of course, all wrong. We could now add a new
+ action below this (or better in our own user.action file) that explicitly
+ un blocks ( "{-block}") paths with "adsl" in them (remember, last match in
+ the configuration wins). There are various ways to handle such exceptions.
+ Example:
+
+ { -block }
+ /adsl
+
+ Now the page displays ;-) Remember to flush your browser's caches when
+ making these kinds of changes to your configuration to insure that you get
+ a freshly delivered page! Or, try using Shift+Reload.
+
+ But now what about a situation where we get no explicit matches like we
+ did with:
+
+ { +block +handle-as-image }
+ /ads
+
+ That actually was very helpful and pointed us quickly to where the problem
+ was. If you don't get this kind of match, then it means one of the default
+ rules in the first section of default.action is causing the problem. This
+ would require some guesswork, and maybe a little trial and error to
+ isolate the offending rule. One likely cause would be one of the "+filter"
+ actions. These tend to be harder to troubleshoot. Try adding the URL for
+ the site to one of aliases that turn off "+filter":
+
+ { shop }
+ .quietpc.com
+ .worldpay.com # for quietpc.com
+ .jungle.com
+ .scan.co.uk
+ .forbes.com
+
+ "{ shop }" is an "alias" that expands to "{ -filter -session-cookies-only
+ }". Or you could do your own exception to negate filtering:
+
+ { -filter }
+ # Disable ALL filter actions for sites in this section
+ .forbes.com
+ developer.ibm.com
+ localhost
+
+ This would turn off all filtering for these sites. This is best put in
+ user.action, for local site exceptions. Note that when a simple domain
+ pattern is used by itself (without the subsequent path portion), all
+ sub-pages within that domain are included automatically in the scope of
+ the action.
+
+ Images that are inexplicably being blocked, may well be hitting the
+ "+filter{banners-by-size}" rule, which assumes that images of certain
+ sizes are ad banners (works well most of the time since these tend to be
+ standardized).
+
+ "{ fragile }" is an alias that disables most actions that are the most
+ likely to cause trouble. This can be used as a last resort for problem
+ sites.
+
+ { fragile }
+ # Handle with care: easy to break
+ mail.google.
+ mybank.example.com
+
+ Remember to flush caches! Note that the mail.google reference lacks the
+ TLD portion (e.g. ".com"). This will effectively match any TLD with google
+ in it, such as mail.google.de., just as an example.
+
+ If this still does not work, you will have to go through the remaining
+ actions one by one to find which one(s) is causing the problem.
projects / privoxy.git / blobdiff