1 Privoxy 3.0.7 User Manual
3 [ Copyright 2001 - 2007 by Privoxy Developers ]
5 $Id: user-manual.sgml,v 2.49 2007/12/06 18:21:55 fabiankeil Exp $
7 The Privoxy User Manual gives users information on how to install, configure
10 Privoxy is a non-caching web proxy with advanced filtering capabilities for
11 enhancing privacy, modifying web page data, managing HTTP cookies, controlling
12 access, and removing ads, banners, pop-ups and other obnoxious Internet junk.
13 Privoxy has a flexible configuration and can be customized to suit individual
14 needs and tastes. Privoxy has application for both stand-alone systems and
17 Privoxy is based on Internet Junkbuster (tm).
19 You can find the latest version of the Privoxy User Manual at http://
20 www.privoxy.org/user-manual/. Please see the Contact section on how to contact
23 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
34 2.1.1. Red Hat and Fedora RPMs
35 2.1.2. Debian and Ubuntu
44 2.2. Building from Source
45 2.3. Keeping your Installation Up-to-Date
47 3. What's New in this Release
49 3.1. Note to Upgraders
51 4. Quickstart to Using Privoxy
53 4.1. Quickstart to Ad Blocking
57 5.1. Red Hat and Fedora
60 5.4. Solaris, NetBSD, FreeBSD, HP-UX and others
65 5.9. Command Line Options
67 6. Privoxy Configuration
69 6.1. Controlling Privoxy with Your Web Browser
70 6.2. Configuration Files Overview
72 7. The Main Configuration File
74 7.1. Local Set-up Documentation
81 7.2. Configuration and Log File Locations
95 7.3.2. single-threaded
97 7.4. Access Control and Security
101 7.4.3. enable-remote-toggle
102 7.4.4. enable-remote-http-toggle
103 7.4.5. enable-edit-actions
104 7.4.6. enforce-blocks
105 7.4.7. ACLs: permit-access and deny-access
111 7.5.2. forward-socks4 and forward-socks4a
112 7.5.3. Advanced Forwarding Examples
113 7.5.4. forwarded-connect-retries
114 7.5.5. accept-intercepted-requests
115 7.5.6. allow-cgi-request-crunching
116 7.5.7. split-large-forms
118 7.6. Windows GUI Options
122 8.1. Finding the Right Mix
124 8.3. How Actions are Applied to Requests
127 8.4.1. The Domain Pattern
128 8.4.2. The Path Pattern
129 8.4.3. The Tag Pattern
135 8.5.3. client-header-filter
136 8.5.4. client-header-tagger
137 8.5.5. content-type-overwrite
138 8.5.6. crunch-client-header
139 8.5.7. crunch-if-none-match
140 8.5.8. crunch-incoming-cookies
141 8.5.9. crunch-server-header
142 8.5.10. crunch-outgoing-cookies
143 8.5.11. deanimate-gifs
144 8.5.12. downgrade-http-version
145 8.5.13. fast-redirects
147 8.5.15. force-text-mode
148 8.5.16. forward-override
149 8.5.17. handle-as-empty-document
150 8.5.18. handle-as-image
151 8.5.19. hide-accept-language
152 8.5.20. hide-content-disposition
153 8.5.21. hide-if-modified-since
154 8.5.22. hide-forwarded-for-headers
155 8.5.23. hide-from-header
156 8.5.24. hide-referrer
157 8.5.25. hide-user-agent
158 8.5.26. inspect-jpegs
160 8.5.28. limit-connect
161 8.5.29. prevent-compression
162 8.5.30. overwrite-last-modified
164 8.5.32. send-vanilla-wafer
166 8.5.34. server-header-filter
167 8.5.35. server-header-tagger
168 8.5.36. session-cookies-only
169 8.5.37. set-image-blocker
170 8.5.38. treat-forbidden-connects-like-blocks
174 8.7. Actions Files Tutorial
176 8.7.1. default.action
181 9.1. Filter File Tutorial
182 9.2. The Pre-defined Filters
184 10. Privoxy's Template Files
185 11. Contacting the Developers, Bug Reporting and Feature Requests
188 11.2. Reporting Problems
190 11.2.1. Reporting Ads or Other Configuration Problems
191 11.2.2. Reporting Bugs
193 11.3. Request New Features
196 12. Privoxy Copyright, License and History
205 14.1. Regular Expressions
206 14.2. Privoxy's Internal Pages
210 14.3. Chain of Events
211 14.4. Troubleshooting: Anatomy of an Action
215 This documentation is included with the current stable version of Privoxy,
218 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
222 In addition to the core features of ad blocking and cookie management, Privoxy
223 provides many supplemental features, that give the end-user more control, more
224 privacy and more freedom:
226 • Integrated browser based configuration and control utility at http://
227 config.privoxy.org/ (shortcut: http://p.p/). Browser-based tracing of rule
228 and filter effects. Remote toggling.
230 • Web page filtering (text replacements, removes banners based on size,
231 invisible "web-bugs", JavaScript and HTML annoyances, pop-up windows,
232 header manipulation, etc.)
234 • Modularized configuration that allows for standard settings and user
235 settings to reside in separate files, so that installing updated actions
236 files won't overwrite individual user settings.
238 • Support for Perl Compatible Regular Expressions in the configuration files,
239 and generally a more sophisticated and flexible configuration syntax over
242 • Improved cookie management features (e.g. session based cookies).
246 • Bypass many click-tracking scripts (avoids script redirection).
248 • Multi-threaded (POSIX and native threads).
250 • User-customizable HTML templates for all proxy-generated pages (e.g.
253 • Auto-detection and re-reading of config file changes.
255 • Improved signal handling, and a true daemon mode (Unix).
257 • Every feature now controllable on a per-site or per-location basis,
258 configuration more powerful and versatile over-all.
260 • Many smaller new features added, limitations and bugs removed, and security
263 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
267 Privoxy is available both in convenient pre-compiled packages for a wide range
268 of operating systems, and as raw source code. For most users, we recommend
269 using the packages, which can be downloaded from our Privoxy Project Page.
271 Note: On some platforms, the installer may remove previously installed
272 versions, if found. (See below for your platform). In any case be sure to
273 backup your old configuration if it is valuable to you. See the note to
274 upgraders section below.
276 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
280 How to install the binary packages depends on your operating system:
282 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
284 2.1.1. Red Hat and Fedora RPMs
286 RPMs can be installed with rpm -Uvh privoxy-3.0.7-1.rpm, and will use /etc/
287 privoxy for the location of configuration files.
289 Note that on Red Hat, Privoxy will not be automatically started on system boot.
290 You will need to enable that using chkconfig, ntsysv, or similar methods.
292 If you have problems with failed dependencies, try rebuilding the SRC RPM: rpm
293 --rebuild privoxy-3.0.7-1.src.rpm. This will use your locally installed
294 libraries and RPM version.
296 Also note that if you have a Junkbuster RPM installed on your system, you need
297 to remove it first, because the packages conflict. Otherwise, RPM will try to
298 remove Junkbuster automatically if found, before installing Privoxy.
300 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
302 2.1.2. Debian and Ubuntu
304 DEBs can be installed with apt-get install privoxy, and will use /etc/privoxy
305 for the location of configuration files.
307 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
311 Just double-click the installer, which will guide you through the installation
312 process. You will find the configuration files in the same directory as you
313 installed Privoxy in.
315 Version 3.0.5 beta introduced full Windows service functionality. On Windows
316 only, the Privoxy program has two new command line arguments to install and
317 uninstall Privoxy as a service.
321 --install[:service_name]
323 --uninstall[:service_name]
325 After invoking Privoxy with --install, you will need to bring up the Windows
326 service console to assign the user you want Privoxy to run under, and whether
327 or not you want it to run whenever the system starts. You can start the Windows
328 services console with the following command: services.msc. If you do not take
329 the manual step of modifying Privoxy's service settings, it will not start.
330 Note too that you will need to give Privoxy a user account that actually
331 exists, or it will not be permitted to write to its log and configuration
334 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
338 Create a new directory, cd to it, then unzip and untar the archive. For the
339 most part, you'll have to figure out where things go.
341 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
345 First, make sure that no previous installations of Junkbuster and / or Privoxy
346 are left on your system. Check that no Junkbuster or Privoxy objects are in
349 Then, just double-click the WarpIN self-installing archive, which will guide
350 you through the installation process. A shadow of the Privoxy executable will
351 be placed in your startup folder so it will start automatically whenever OS/2
354 The directory you choose to install Privoxy into will contain all of the
357 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
361 Unzip the downloaded file (you can either double-click on the file from the
362 finder, or from the desktop if you downloaded it there). Then, double-click on
363 the package installer icon named Privoxy.pkg and follow the installation
364 process. Privoxy will be installed in the folder /Library/Privoxy. It will
365 start automatically whenever you start up. To prevent it from starting
366 automatically, remove or rename the folder /Library/StartupItems/Privoxy.
368 To start Privoxy by hand, double-click on StartPrivoxy.command in the /Library/
369 Privoxy folder. Or, type this command in the Terminal:
371 /Library/Privoxy/StartPrivoxy.command
375 You will be prompted for the administrator password.
377 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
381 Copy and then unpack the lha archive to a suitable location. All necessary
382 files will be installed into Privoxy directory, including all configuration and
383 log files. To uninstall, just remove this directory.
385 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
389 Privoxy is part of FreeBSD's Ports Collection, you can build and install it
390 with cd /usr/ports/www/privoxy; make install clean.
392 If you don't use the ports, you can fetch and install the package with pkg_add
395 The port skeleton and the package can also be downloaded from the File Release
396 Page, but there's no reason to use them unless you're interested in the beta
397 releases which are only available there.
399 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
403 Gentoo source packages (Ebuilds) for Privoxy are contained in the Gentoo
404 Portage Tree (they are not on the download page, but there is a Gentoo section,
405 where you can see when a new Privoxy Version is added to the Portage Tree).
407 Before installing Privoxy under Gentoo just do first emerge rsync to get the
408 latest changes from the Portage tree. With emerge privoxy you install the
411 Configuration files are in /etc/privoxy, the documentation is in /usr/share/doc
412 /privoxy-3.0.7 and the Log directory is in /var/log/privoxy.
414 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
416 2.2. Building from Source
418 The most convenient way to obtain the Privoxy sources is to download the source
419 tarball from our project download page.
421 If you like to live on the bleeding edge and are not afraid of using possibly
422 unstable development versions, you can check out the up-to-the-minute version
423 directly from the CVS repository.
425 To build Privoxy from source, autoconf, GNU make (gmake), and, of course, a C
426 compiler like gcc are required.
428 When building from a source tarball, first unpack the source:
430 tar xzvf privoxy-3.0.7-src* [.tgz or .tar.gz]
434 For retrieving the current CVS sources, you'll need a CVS client installed.
435 Note that sources from CVS are typically development quality, and may not be
436 stable, or well tested. To download CVS source, check the Sourceforge
437 documentation, which might give commands like:
439 cvs -d:pserver:anonymous@ijbswa.cvs.sourceforge.net:/cvsroot/ijbswa login
440 cvs -z3 -d:pserver:anonymous@ijbswa.cvs.sourceforge.net:/cvsroot/ijbswa co current
444 This will create a directory named current/, which will contain the source
447 You can also check out any Privoxy "branch", just exchange the current name
448 with the wanted branch name (Example: v_3_0_branch for the 3.0 cvs tree).
450 It is also strongly recommended to not run Privoxy as root. You should
451 configure/install/run Privoxy as an unprivileged user, preferably by creating a
452 "privoxy" user and group just for this purpose. See your local documentation
453 for the correct command line to do add new users and groups (something like
454 adduser, but the command syntax may vary from platform to platform).
456 /etc/passwd might then look like:
458 privoxy:*:7777:7777:privoxy proxy:/no/home:/no/shell
461 And then /etc/group, like:
466 Some binary packages may do this for you.
468 Then, to build from either unpacked tarball or CVS source:
472 ./configure # (--help to see options)
473 make # (the make from GNU, sometimes called gmake)
474 su # Possibly required
475 make -n install # (to see where all the files will go)
476 make -s install # (to really install, -s to silence output)
479 Using GNU make, you can have the first four steps automatically done for you by
485 in the freshly downloaded or unpacked source directory.
487 To build an executable with security enhanced features so that users cannot
488 easily bypass the proxy (e.g. "Go There Anyway"), or alter their own
489 configurations, configure like this:
491 ./configure --disable-toggle --disable-editor --disable-force
494 Then build as above. In Privoxy 3.0.7 and later, all of these options can also
495 be disabled through the configuration file.
497 WARNING: If installing as root, the install will fail unless a non-root user or
498 group is specified, or a privoxy user and group already exist on the system. If
499 a non-root user is specified, and no group, then the installation will try to
500 also use a group of the same name as "user". If a group is specified (and no
501 user), then the support files will be installed as writable by that group, and
502 owned by the user running the installation.
504 configure accepts --with-user and --with-group options for setting user and
505 group ownership of the configuration files (which need to be writable by the
506 daemon). The specified user must already exist. When starting Privoxy, it must
507 be run as this same user to insure write access to configuration and log files!
509 Alternately, you can specify user and group on the make command line, but be
510 sure both already exist:
512 make -s install USER=privoxy GROUP=privoxy
515 The default installation path for make install is /usr/local. This may of
516 course be customized with the various ./configure path options. If you are
517 doing an install to anywhere besides /usr/local, be sure to set the appropriate
518 paths with the correct configure options (./configure --help). Non-privileged
519 users must of course have write access permissions to wherever the target
520 installation is going.
522 If you do install to /usr/local, the install will use sysconfdir=$prefix/etc/
523 privoxy by default. All other destinations, and the direct usage of
524 --sysconfdir flag behave like normal, i.e. will not add the extra privoxy
525 directory. This is for a safer install, as there may already exist another
526 program that uses a file with the "config" name, and thus makes /usr/local/etc
529 If installing to /usr/local, the documentation will go by default to $prefix/
530 share/doc. But if this directory doesn't exist, it will then try $prefix/doc
531 and install there before creating a new $prefix/share/doc just for Privoxy.
533 Again, if the installs goes to /usr/local, the localstatedir (ie: var/) will
534 default to /var instead of $prefix/var so the logs will go to /var/log/privoxy
535 /, and the pid file will be created in /var/run/privoxy.pid.
537 make install will attempt to set the correct values in config (main
538 configuration file). You should check this to make sure all values are correct.
539 If appropriate, an init script will be installed, but it is up to the user to
540 determine how and where to start Privoxy. The init script should be checked for
541 correct paths and values, if anything other than a default install is done.
543 If install finds previous versions of local configuration files, most of these
544 will not be overwritten, and the new ones will be installed with a "new"
545 extension. default.action, default.filter, and standard.action will be
546 overwritten. You will then need to manually update the other installed
547 configuration files as needed. The default template files will be overwritten.
548 If you have customized, local templates, these should be stored safely in a
549 separate directory and defined in config by the "templdir" directive. It is of
550 course wise to always back-up any important configuration files "just in case".
551 If a previous version of Privoxy is already running, you will have to restart
554 For more detailed instructions on how to build Redhat RPMs, Windows
555 self-extracting installers, building on platforms with special requirements
556 etc, please consult the developer manual.
558 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
560 2.3. Keeping your Installation Up-to-Date
562 As user feedback comes in and development continues, we will make updated
563 versions of both the main actions file (as a separate package) and the software
564 itself (including the actions file) available for download.
566 If you wish to receive an email notification whenever we release updates of
567 Privoxy or the actions file, subscribe to our announce mailing list,
568 ijbswa-announce@lists.sourceforge.net.
570 In order not to lose your personal changes and adjustments when updating to the
571 latest default.action file we strongly recommend that you use user.action and
572 user.filter for your local customizations of Privoxy. See the Chapter on
573 actions files for details.
575 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
577 3. What's New in this Release
579 There are many improvements and new features since Privoxy 3.0.6, the last
582 • Two new actions server-header-tagger and client-header-tagger that can be
583 used to create arbitrary "tags" based on client and server headers. These
584 "tags" can then subsequently be used to control the other actions used for
585 the current request, greatly increasing Privoxy's flexibility and
586 selectivity. See tag patterns for more information on tags.
588 • Header filtering is done with dedicated header filters now. As a result the
589 actions "filter-client-headers" and "filter-server-headers" that were
590 introduced with Privoxy 3.0.5 to apply content filters to the headers have
591 been removed. See the new actions server-header-filter and
592 client-header-filter for details.
594 • There are four new options for the main config file:
596 □ allow-cgi-request-crunching which allows requests for Privoxy's
597 internal CGI pages to be blocked, redirected or (un)trusted like
600 □ split-large-forms that will work around a browser bug that caused IE6
601 and IE7 to ignore the Submit button on the Privoxy's
602 edit-actions-for-url CGI page.
604 □ accept-intercepted-requests which allows to combine Privoxy with any
605 packet filter to create an intercepting proxy for HTTP/1.1 requests
606 (and for HTTP/1.0 requests with Host header set). This means clients
607 can be forced to use Privoxy even if their proxy settings are
608 configured differently.
610 □ templdir to designate an alternate location for Privoxy's locally
611 customized CGI templates so that these are not overwritten during
614 • A new command line option --pre-chroot-nslookup hostname to initialize the
615 resolver library before chroot'ing. On some systems this reduces the number
616 of files that must be copied into the chroot tree. (Patch provided by
619 • The forward-override action allows changing of the forwarding settings
620 through the actions files. Combined with tags, this allows to choose the
621 forwarder based on client headers like the User-Agent, or the request
624 • The redirect action can now use regular expression substitutions against
627 • zlib support is now available as a compile time option to filter compressed
628 content. Patch provided by Wil Mahan.
630 • Improve various filters, and add new ones.
632 • Include support for RFC 3253 so that Subversion works with Privoxy. Patch
633 provided by Petr Kadlec.
635 • Logging can be completely turned off by not specifying a logfile directive.
637 • A number of improvements to Privoxy's internal CGI pages, including the use
638 of favicons for error and control pages.
640 • Many bugfixes, memory leaks addressed, code improvements, and logging
643 For a more detailed list of changes please have a look at the ChangeLog.
645 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
647 3.1. Note to Upgraders
649 A quick list of things to be aware of before upgrading from earlier versions of
652 • The recommended way to upgrade Privoxy is to backup your old configuration
653 files, install the new ones, verify that Privoxy is working correctly and
654 finally merge back your changes using diff and maybe patch.
656 There are a number of new features in each Privoxy release and most of them
657 have to be explicitly enabled in the configuration files. Old configuration
658 files obviously don't do that and due to syntax changes using old
659 configuration files with a new Privoxy isn't always possible anyway.
661 • Note that some installers remove earlier versions completely, including
662 configuration files, therefore you should really save any important
665 • On the other hand, other installers don't overwrite existing configuration
666 files, thinking you will want to do that yourself.
668 • standard.action now only includes the enabled actions. Not all actions as
671 • Logging is off by default now. If you need logging, it can be turned on in
672 the config file. You may also want to enable logging until you verified
673 that the new Privoxy version is working as expected.
675 • Three other config file settings are now off by default:
676 enable-remote-toggle, enable-remote-http-toggle, and enable-edit-actions.
677 If you use or want these, you will need to explicitly enable them, and be
678 aware of the security issues involved.
680 • The "filter-client-headers" and "filter-server-headers" actions that were
681 introduced with Privoxy 3.0.5 to apply content filters to the headers have
682 been removed and replaced with new actions. See the What's New section
685 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
687 4. Quickstart to Using Privoxy
689 • Install Privoxy. See the Installation Section below for platform specific
692 • Advanced users and those who want to offer Privoxy service to more than
693 just their local machine should check the main config file, especially the
694 security-relevant options. These are off by default.
696 • Start Privoxy, if the installation program has not done this already (may
697 vary according to platform). See the section Starting Privoxy.
699 • Set your browser to use Privoxy as HTTP and HTTPS (SSL) proxy by setting
700 the proxy configuration for address of 127.0.0.1 and port 8118. DO NOT
701 activate proxying for FTP or any protocols besides HTTP and HTTPS (SSL)
702 unless you intend to prevent your browser from using these protocols.
704 • Flush your browser's disk and memory caches, to remove any cached ad
705 images. If using Privoxy to manage cookies, you should remove any currently
708 • A default installation should provide a reasonable starting point for most.
709 There will undoubtedly be occasions where you will want to adjust the
710 configuration, but that can be dealt with as the need arises. Little to no
711 initial configuration is required in most cases, you may want to enable the
712 web-based action editor though. Be sure to read the warnings first.
714 See the Configuration section for more configuration options, and how to
715 customize your installation. You might also want to look at the next
716 section for a quick introduction to how Privoxy blocks ads and banners.
718 • If you experience ads that slip through, innocent images that are blocked,
719 or otherwise feel the need to fine-tune Privoxy's behavior, take a look at
720 the actions files. As a quick start, you might find the richly commented
721 examples helpful. You can also view and edit the actions files through the
722 web-based user interface. The Appendix "Troubleshooting: Anatomy of an
723 Action" has hints on how to understand and debug actions that "misbehave".
725 • Please see the section Contacting the Developers on how to report bugs,
726 problems with websites or to get help.
728 • Now enjoy surfing with enhanced control, comfort and privacy!
730 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
732 4.1. Quickstart to Ad Blocking
734 Ad blocking is but one of Privoxy's array of features. Many of these features
735 are for the technically minded advanced user. But, ad and banner blocking is
736 surely common ground for everybody.
738 This section will provide a quick summary of ad blocking so you can get up to
739 speed quickly without having to read the more extensive information provided
740 below, though this is highly recommended.
742 First a bit of a warning ... blocking ads is much like blocking SPAM: the more
743 aggressive you are about it, the more likely you are to block things that were
744 not intended. And the more likely that some things may not work as intended. So
745 there is a trade off here. If you want extreme ad free browsing, be prepared to
746 deal with more "problem" sites, and to spend more time adjusting the
747 configuration to solve these unintended consequences. In short, there is not an
748 easy way to eliminate all ads. Either take the easy way and settle for most ads
749 blocked with the default configuration, or jump in and tweak it for your
750 personal surfing habits and preferences.
752 Secondly, a brief explanation of Privoxy's "actions". "Actions" in this
753 context, are the directives we use to tell Privoxy to perform some task
754 relating to HTTP transactions (i.e. web browsing). We tell Privoxy to take some
755 "action". Each action has a unique name and function. While there are many
756 potential actions in Privoxy's arsenal, only a few are used for ad blocking.
757 Actions, and action configuration files, are explained in depth below.
759 Actions are specified in Privoxy's configuration, followed by one or more URLs
760 to which the action should apply. URLs can actually be URL type patterns that
761 use wildcards so they can apply potentially to a range of similar URLs. The
762 actions, together with the URL patterns are called a section.
764 When you connect to a website, the full URL will either match one or more of
765 the sections as defined in Privoxy's configuration, or not. If so, then Privoxy
766 will perform the respective actions. If not, then nothing special happens.
767 Furthermore, web pages may contain embedded, secondary URLs that your web
768 browser will use to load additional components of the page, as it parses the
769 original page's HTML content. An ad image for instance, is just an URL embedded
770 in the page somewhere. The image itself may be on the same server, or a server
771 somewhere else on the Internet. Complex web pages will have many such embedded
772 URLs. Privoxy can deal with each URL individually, so, for instance, the main
773 page text is not touched, but images from such-and-such server are blocked.
775 The most important actions for basic ad blocking are: block, handle-as-image,
776 handle-as-empty-document,and set-image-blocker:
778 • block - this is perhaps the single most used action, and is particularly
779 important for ad blocking. This action stops any contact between your
780 browser and any URL patterns that match this action's configuration. It can
781 be used for blocking ads, but also anything that is determined to be
782 unwanted. By itself, it simply stops any communication with the remote
783 server and sends Privoxy's own built-in BLOCKED page instead to let you now
784 what has happened (with some exceptions, see below).
786 • handle-as-image - tells Privoxy to treat this URL as an image. Privoxy's
787 default configuration already does this for all common image types (e.g.
788 GIF), but there are many situations where this is not so easy to determine.
789 So we'll force it in these cases. This is particularly important for ad
790 blocking, since only if we know that it's an image of some kind, can we
791 replace it with an image of our choosing, instead of the Privoxy BLOCKED
792 page (which would only result in a "broken image" icon). There are some
793 limitations to this though. For instance, you can't just brute-force an
794 image substitution for an entire HTML page in most situations.
796 • handle-as-empty-document - sends an empty document instead of Privoxy's
797 normal BLOCKED HTML page. This is useful for file types that are neither
798 HTML nor images, such as blocking JavaScript files.
800 • set-image-blocker - tells Privoxy what to display in place of an ad image
801 that has hit a block rule. For this to come into play, the URL must match a
802 block action somewhere in the configuration, and, it must also match an
803 handle-as-image action.
805 The configuration options on what to display instead of the ad are:
807 pattern - a checkerboard pattern, so that an ad replacement is obvious.
810 blank - A very small empty GIF image is displayed. This is the so-called
811 "invisible" configuration option.
813 http://<URL> - A redirect to any image anywhere of the user's choosing
816 Advanced users will eventually want to explore Privoxy filters as well. Filters
817 are very different from blocks. A "block" blocks a site, page, or unwanted
818 contented. Filters are a way of filtering or modifying what is actually on the
819 page. An example filter usage: a text replacement of "no-no" for "nasty-word".
820 That is a very simple example. This process can be used for ad blocking, but it
821 is more in the realm of advanced usage and has some pitfalls to be wary off.
823 The quickest way to adjust any of these settings is with your browser through
824 the special Privoxy editor at http://config.privoxy.org/show-status (shortcut:
825 http://p.p/show-status). This is an internal page, and does not require
828 Note that as of Privoxy 3.0.7 beta the action editor is disabled by default.
829 Check the enable-edit-actions section in the configuration file to learn why
830 and in which cases it's safe to enable again.
832 If you decided to enable the action editor, select the appropriate "actions"
833 file, and click "Edit". It is best to put personal or local preferences in
834 user.action since this is not meant to be overwritten during upgrades, and will
835 over-ride the settings in other files. Here you can insert new "actions", and
836 URLs for ad blocking or other purposes, and make other adjustments to the
837 configuration. Privoxy will detect these changes automatically.
839 A quick and simple step by step example:
841 • Right click on the ad image to be blocked, then select "Copy Link Location"
842 from the pop-up menu.
844 • Set your browser to http://config.privoxy.org/show-status
846 • Find user.action in the top section, and click on "Edit":
848 Figure 1. Actions Files in Use
852 • You should have a section with only block listed under "Actions:". If not,
853 click a "Insert new section below" button, and in the new section that just
854 appeared, click the Edit button right under the word "Actions:". This will
855 bring up a list of all actions. Find block near the top, and click in the
856 "Enabled" column, then "Submit" just below the list.
858 • Now, in the block actions section, click the "Add" button, and paste the
859 URL the browser got from "Copy Link Location". Remove the http:// at the
860 beginning of the URL. Then, click "Submit" (or "OK" if in a pop-up window).
862 • Now go back to the original page, and press SHIFT-Reload (or flush all
863 browser caches). The image should be gone now.
865 This is a very crude and simple example. There might be good reasons to use a
866 wildcard pattern match to include potentially similar images from the same
867 site. For a more extensive explanation of "patterns", and the entire actions
868 concept, see the Actions section.
870 For advanced users who want to hand edit their config files, you might want to
871 now go to the Actions Files Tutorial. The ideas explained therein also apply to
872 the web-based editor.
874 There are also various filters that can be used for ad blocking (filters are a
875 special subset of actions). These fall into the "advanced" usage category, and
876 are explained in depth in later sections.
878 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
882 Before launching Privoxy for the first time, you will want to configure your
883 browser(s) to use Privoxy as a HTTP and HTTPS (SSL) proxy. The default is
884 127.0.0.1 (or localhost) for the proxy address, and port 8118 (earlier versions
885 used port 8000). This is the one configuration step that must be done!
887 Please note that Privoxy can only proxy HTTP and HTTPS traffic. It will not
888 work with FTP or other protocols.
890 Figure 2. Proxy Configuration Showing Mozilla/Netscape HTTP and HTTPS (SSL)
895 With Firefox, this is typically set under:
897 Tools -> Options -> General -> Connection Settings -> Manual Proxy
901 Or optionally on some platforms:
903 Edit -> Preferences -> General -> Connection Settings -> Manual Proxy
907 With Netscape (and Mozilla), this can be set under:
909 Edit -> Preferences -> Advanced -> Proxies -> HTTP Proxy
912 For Internet Explorer v.5-6:
914 Tools -> Internet Options -> Connections -> LAN Settings
916 Then, check "Use Proxy" and fill in the appropriate info (Address: 127.0.0.1,
917 Port: 8118). Include HTTPS (SSL), if you want HTTPS proxy support too
918 (sometimes labeled "Secure"). Make sure any checkboxes like "Use the same proxy
919 server for all protocols" is UNCHECKED. You want only HTTP and HTTPS (SSL)!
921 Figure 3. Proxy Configuration Showing Internet Explorer HTTP and HTTPS (Secure)
926 After doing this, flush your browser's disk and memory caches to force a
927 re-reading of all pages and to get rid of any ads that may be cached. Remove
928 any cookies, if you want Privoxy to manage that. You are now ready to start
929 enjoying the benefits of using Privoxy!
931 Privoxy itself is typically started by specifying the main configuration file
932 to be used on the command line. If no configuration file is specified on the
933 command line, Privoxy will look for a file named config in the current
934 directory. Except on Win32 where it will try config.txt.
936 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
938 5.1. Red Hat and Fedora
940 A default Red Hat installation may not start Privoxy upon boot. It will use the
941 file /etc/privoxy/config as its main configuration file.
943 # /etc/rc.d/init.d/privoxy start
948 # service privoxy start
951 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
955 We use a script. Note that Debian typically starts Privoxy upon booting per
956 default. It will use the file /etc/privoxy/config as its main configuration
959 # /etc/init.d/privoxy start
962 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
966 Click on the Privoxy Icon to start Privoxy. If no configuration file is
967 specified on the command line, Privoxy will look for a file named config.txt.
968 Note that Windows will automatically start Privoxy when the system starts if
969 you chose that option when installing.
971 Privoxy can run with full Windows service functionality. On Windows only, the
972 Privoxy program has two new command line arguments to install and uninstall
973 Privoxy as a service. See the Windows Installation instructions for details.
975 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
977 5.4. Solaris, NetBSD, FreeBSD, HP-UX and others
979 Example Unix startup command:
981 # /usr/sbin/privoxy /etc/privoxy/config
984 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
988 During installation, Privoxy is configured to start automatically when the
989 system restarts. You can start it manually by double-clicking on the Privoxy
990 icon in the Privoxy folder.
992 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
996 During installation, Privoxy is configured to start automatically when the
997 system restarts. To start Privoxy manually, double-click on the
998 StartPrivoxy.command icon in the /Library/Privoxy folder. Or, type this command
1001 /Library/Privoxy/StartPrivoxy.command
1005 You will be prompted for the administrator password.
1007 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1011 Start Privoxy (with RUN <>NIL:) in your startnet script (AmiTCP), in
1012 s:user-startup (RoadShow), as startup program in your startup script (Genesis),
1013 or as startup action (Miami and MiamiDx). Privoxy will automatically quit when
1014 you quit your TCP/IP stack (just ignore the harmless warning your TCP/IP stack
1015 may display that Privoxy is still running).
1017 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1021 A script is again used. It will use the file /etc/privoxy/config as its main
1024 /etc/init.d/privoxy start
1028 Note that Privoxy is not automatically started at boot time by default. You can
1029 change this with the rc-update command.
1031 rc-update add privoxy default
1035 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1037 5.9. Command Line Options
1039 Privoxy may be invoked with the following command-line options:
1043 Print version info and exit. Unix only.
1047 Print short usage info and exit. Unix only.
1051 Don't become a daemon, i.e. don't fork and become process group leader, and
1052 don't detach from controlling tty. Unix only.
1056 On startup, write the process ID to FILE. Delete the FILE on exit. Failure
1057 to create or delete the FILE is non-fatal. If no FILE option is given, no
1058 PID file will be used. Unix only.
1060 • --user USER[.GROUP]
1062 After (optionally) writing the PID file, assume the user ID of USER, and if
1063 included the GID of GROUP. Exit if the privileges are not sufficient to do
1068 Before changing to the user ID given in the --user option, chroot to that
1069 user's home directory, i.e. make the kernel pretend to the Privoxy process
1070 that the directory tree starts there. If set up carefully, this can limit
1071 the impact of possible vulnerabilities in Privoxy to the files contained in
1072 that hierarchy. Unix only.
1074 • --pre-chroot-nslookup hostname
1076 Specifies a hostname to look up before doing a chroot. On some systems,
1077 initializing the resolver library involves reading config files from /etc
1078 and/or loading additional shared libraries from /lib. On these systems,
1079 doing a hostname lookup before the chroot reduces the number of files that
1080 must be copied into the chroot tree.
1082 For fastest startup speed, a good value is a hostname that is not in /etc/
1083 hosts but that your local name server (listed in /etc/resolv.conf) can
1084 resolve without recursion (that is, without having to ask any other name
1085 servers). The hostname need not exist, but if it doesn't, an error message
1086 (which can be ignored) will be output.
1090 If no configfile is included on the command line, Privoxy will look for a
1091 file named "config" in the current directory (except on Win32 where it will
1092 look for "config.txt" instead). Specify full path to avoid confusion. If no
1093 config file is found, Privoxy will fail to start.
1095 On MS Windows only there are two additional command-line options to allow
1096 Privoxy to install and run as a service. See the Window Installation section
1099 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1101 6. Privoxy Configuration
1103 All Privoxy configuration is stored in text files. These files can be edited
1104 with a text editor. Many important aspects of Privoxy can also be controlled
1105 easily with a web browser.
1107 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1109 6.1. Controlling Privoxy with Your Web Browser
1111 Privoxy's user interface can be reached through the special URL http://
1112 config.privoxy.org/ (shortcut: http://p.p/), which is a built-in page and works
1113 without Internet access. You will see the following section:
1116 ▪ View & change the current configuration
1117 ▪ View the source code version numbers
1118 ▪ View the request headers.
1119 ▪ Look up which actions apply to a URL and why
1120 ▪ Toggle Privoxy on or off
1124 This should be self-explanatory. Note the first item leads to an editor for the
1125 actions files, which is where the ad, banner, cookie, and URL blocking magic is
1126 configured as well as other advanced features of Privoxy. This is an easy way
1127 to adjust various aspects of Privoxy configuration. The actions file, and other
1128 configuration files, are explained in detail below.
1130 "Toggle Privoxy On or Off" is handy for sites that might have problems with
1131 your current actions and filters. You can in fact use it as a test to see
1132 whether it is Privoxy causing the problem or not. Privoxy continues to run as a
1133 proxy in this case, but all manipulation is disabled, i.e. Privoxy acts like a
1134 normal forwarding proxy. There is even a toggle Bookmarklet offered, so that
1135 you can toggle Privoxy with one click from your browser.
1137 Note that several of the features described above are disabled by default in
1138 Privoxy 3.0.7 beta and later. Check the configuration file to learn why and in
1139 which cases it's safe to enable them again.
1141 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1143 6.2. Configuration Files Overview
1145 For Unix, *BSD and Linux, all configuration files are located in /etc/privoxy/
1146 by default. For MS Windows, OS/2, and AmigaOS these are all in the same
1147 directory as the Privoxy executable.
1149 The installed defaults provide a reasonable starting point, though some
1150 settings may be aggressive by some standards. For the time being, the principle
1151 configuration files are:
1153 • The main configuration file is named config on Linux, Unix, BSD, OS/2, and
1154 AmigaOS and config.txt on Windows. This is a required file.
1156 • default.action (the main actions file) is used to define which "actions"
1157 relating to banner-blocking, images, pop-ups, content modification, cookie
1158 handling etc should be applied by default. It also defines many exceptions
1159 (both positive and negative) from this default set of actions that enable
1160 Privoxy to selectively eliminate the junk, and only the junk, on as many
1161 websites as possible.
1163 Multiple actions files may be defined in config. These are processed in the
1164 order they are defined. Local customizations and locally preferred
1165 exceptions to the default policies as defined in default.action (which you
1166 will most probably want to define sooner or later) are probably best
1167 applied in user.action, where you can preserve them across upgrades.
1168 standard.action is only for Privoxy's internal use.
1170 There is also a web based editor that can be accessed from http://
1171 config.privoxy.org/show-status (Shortcut: http://p.p/show-status) for the
1172 various actions files.
1174 • "Filter files" (the filter file) can be used to re-write the raw page
1175 content, including viewable text as well as embedded HTML and JavaScript,
1176 and whatever else lurks on any given web page. The filtering jobs are only
1177 pre-defined here; whether to apply them or not is up to the actions files.
1178 default.filter includes various filters made available for use by the
1179 developers. Some are much more intrusive than others, and all should be
1180 used with caution. You may define additional filter files in config as you
1181 can with actions files. We suggest user.filter for any locally defined
1182 filters or customizations.
1184 The syntax of the configuration and filter files may change between different
1185 Privoxy versions, unfortunately some enhancements cost backwards compatibility.
1187 All files use the "#" character to denote a comment (the rest of the line will
1188 be ignored) and understand line continuation through placing a backslash ("\")
1189 as the very last character in a line. If the # is preceded by a backslash, it
1190 looses its special function. Placing a # in front of an otherwise valid
1191 configuration line to prevent it from being interpreted is called "commenting
1192 out" that line. Blank lines are ignored.
1194 The actions files and filter files can use Perl style regular expressions for
1195 maximum flexibility.
1197 After making any changes, there is no need to restart Privoxy in order for the
1198 changes to take effect. Privoxy detects such changes automatically. Note,
1199 however, that it may take one or two additional requests for the change to take
1200 effect. When changing the listening address of Privoxy, these "wake up"
1201 requests must obviously be sent to the old listening address.
1203 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1205 7. The Main Configuration File
1207 Again, the main configuration file is named config on Linux/Unix/BSD and OS/2,
1208 and config.txt on Windows. Configuration lines consist of an initial keyword
1209 followed by a list of values, all separated by whitespace (any number of spaces
1210 or tabs). For example:
1212 confdir /etc/privoxy
1214 Assigns the value /etc/privoxy to the option confdir and thus indicates that
1215 the configuration directory is named "/etc/privoxy/".
1217 All options in the config file except for confdir and logdir are optional.
1218 Watch out in the below description for what happens if you leave them unset.
1220 The main config file controls all aspects of Privoxy's operation that are not
1221 location dependent (i.e. they apply universally, no matter where you may be
1224 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1226 7.1. Local Set-up Documentation
1228 If you intend to operate Privoxy for more users than just yourself, it might be
1229 a good idea to let them know how to reach you, what you block and why you do
1230 that, your policies, etc.
1232 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1238 Location of the Privoxy User Manual.
1242 A fully qualified URI
1250 http://www.privoxy.org/version/user-manual/ will be used, where version is
1251 the Privoxy version.
1255 The User Manual URI is the single best source of information on Privoxy,
1256 and is used for help links from some of the internal CGI pages. The manual
1257 itself is normally packaged with the binary distributions, so you probably
1258 want to set this to a locally installed copy.
1262 The best all purpose solution is simply to put the full local PATH to where
1263 the User Manual is located:
1265 user-manual /usr/share/doc/privoxy/user-manual
1268 The User Manual is then available to anyone with access to Privoxy, by
1269 following the built-in URL: http://config.privoxy.org/user-manual/ (or the
1270 shortcut: http://p.p/user-manual/).
1272 If the documentation is not on the local system, it can be accessed from a
1275 user-manual http://example.com/privoxy/user-manual/
1278 ┌─────────────────────────────────────────────────────────────────┐
1280 ├─────────────────────────────────────────────────────────────────┤
1281 │If set, this option should be the first option in the config │
1282 │file, because it is used while the config file is being read on │
1284 └─────────────────────────────────────────────────────────────────┘
1286 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1288 7.1.2. trust-info-url
1292 A URL to be displayed in the error page that users will see if access to an
1293 untrusted page is denied.
1301 Two example URLs are provided
1305 No links are displayed on the "untrusted" error page.
1309 The value of this option only matters if the experimental trust mechanism
1310 has been activated. (See trustfile below.)
1312 If you use the trust mechanism, it is a good idea to write up some on-line
1313 documentation about your trust policy and to specify the URL(s) here. Use
1314 multiple times for multiple URLs.
1316 The URL(s) should be added to the trustfile as well, so users don't end up
1317 locked out from the information on why they were locked out in the first
1320 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1322 7.1.3. admin-address
1326 An email address to reach the Privoxy administrator.
1338 No email address is displayed on error pages and the CGI user interface.
1342 If both admin-address and proxy-info-url are unset, the whole "Local
1343 Privoxy Support" box on all generated pages will not be shown.
1345 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1347 7.1.4. proxy-info-url
1351 A URL to documentation about the local Privoxy setup, configuration or
1364 No link to local documentation is displayed on error pages and the CGI user
1369 If both admin-address and proxy-info-url are unset, the whole "Local
1370 Privoxy Support" box on all generated pages will not be shown.
1372 This URL shouldn't be blocked ;-)
1374 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1376 7.2. Configuration and Log File Locations
1378 Privoxy can (and normally does) use a number of other files for additional
1379 configuration, help and logging. This section of the configuration file tells
1380 Privoxy where to find those other files.
1382 The user running Privoxy, must have read permission for all configuration
1383 files, and write permission to any files that would be modified, such as log
1384 files and actions files.
1386 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1392 The directory where the other configuration files are located.
1400 /etc/privoxy (Unix) or Privoxy installation dir (Windows)
1408 No trailing "/", please.
1410 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1416 An alternative directory where the templates are loaded from.
1428 The templates are assumed to be located in confdir/template.
1432 Privoxy's original templates are usually overwritten with each update. Use
1433 this option to relocate customized templates that should be kept. As
1434 template variables might change between updates, you shouldn't expect
1435 templates to work with Privoxy releases other than the one they were part
1438 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1444 The directory where all logging takes place (i.e. where logfile and jarfile
1453 /var/log/privoxy (Unix) or Privoxy installation dir (Windows)
1461 No trailing "/", please.
1463 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1469 The actions file(s) to use
1473 Complete file name, relative to confdir
1477 standard.action # Internal purposes, no editing recommended
1479 default.action # Main actions file
1481 user.action # User customizations
1485 No actions are taken at all. More or less neutral proxying.
1489 Multiple actionsfile lines are permitted, and are in fact recommended!
1491 The default values include standard.action, which is used for internal
1492 purposes and should be loaded, default.action, which is the "main" actions
1493 file maintained by the developers, and user.action, where you can make your
1496 Actions files contain all the per site and per URL configuration for ad
1497 blocking, cookie management, privacy considerations, etc. There is no point
1498 in using Privoxy without at least one actions file.
1500 Note that since Privoxy 3.0.7, the complete filename, including the
1501 ".action" extension has to be specified. The syntax change was necessary to
1502 be consistent with the other file options and to allow previously forbidden
1505 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1511 The filter file(s) to use
1515 File name, relative to confdir
1519 default.filter (Unix) or default.filter.txt (Windows)
1523 No textual content filtering takes place, i.e. all +filter{name} actions in
1524 the actions files are turned neutral.
1528 Multiple filterfile lines are permitted.
1530 The filter files contain content modification rules that use regular
1531 expressions. These rules permit powerful changes on the content of Web
1532 pages, and optionally the headers as well, e.g., you could try to disable
1533 your favorite JavaScript annoyances, re-write the actual displayed text, or
1534 just have some fun playing buzzword bingo with web pages.
1536 The +filter{name} actions rely on the relevant filter (name) to be defined
1539 A pre-defined filter file called default.filter that contains a number of
1540 useful filters for common problems is included in the distribution. See the
1541 section on the filter action for a list.
1543 It is recommended to place any locally adapted filters into a separate
1544 file, such as user.filter.
1546 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1556 File name, relative to logdir
1560 Unset (commented out). When activated: logfile (Unix) or privoxy.log
1565 Logging is disabled unless --no-daemon mode is used.
1569 The logfile is where all logging and error messages are written. The level
1570 of detail and number of messages are set with the debug option (see below).
1571 The logfile can be useful for tracking down a problem with Privoxy (e.g.,
1572 it's not blocking an ad you think it should block) and it can help you to
1573 monitor what your browser is doing.
1575 Many users will never look at it, however, and it's a privacy risk if third
1576 parties can get access to it. It is therefore disabled by default in
1577 Privoxy 3.0.7 and later.
1579 For troubleshooting purposes, you will have to explicitly enable it. Please
1580 don't file any support requests without trying to reproduce the problem
1581 with logging enabled first. Once you read the log messages, you may even be
1582 able to solve the problem on your own.
1584 Your logfile will grow indefinitely, and you will probably want to
1585 periodically remove it. On Unix systems, you can do this with a cron job
1586 (see "man cron"). For Red Hat based Linux distributions, a logrotate script
1589 Any log files must be writable by whatever user Privoxy is being run as (on
1590 Unix, default user id is "privoxy").
1592 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1598 The file to store intercepted cookies in
1602 File name, relative to logdir
1606 Unset (commented out). When activated: jarfile (Unix) or privoxy.jar
1611 Intercepted cookies are not stored in a dedicated log file.
1615 The jarfile may grow to ridiculous sizes over time.
1617 If debug 8 (show header parsing) is enabled, cookies are also written to
1618 the logfile with the rest of the headers. Therefore this option isn't very
1619 useful and may be removed in future releases. Please report to the
1620 developers if you are still using it.
1622 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1628 The name of the trust file to use
1632 File name, relative to confdir
1636 Unset (commented out). When activated: trust (Unix) or trust.txt (Windows)
1640 The entire trust mechanism is disabled.
1644 The trust mechanism is an experimental feature for building white-lists and
1645 should be used with care. It is NOT recommended for the casual user.
1647 If you specify a trust file, Privoxy will only allow access to sites that
1648 are specified in the trustfile. Sites can be listed in one of two ways:
1650 Prepending a ~ character limits access to this site only (and any sub-paths
1651 within this site), e.g. ~www.example.com allows access to ~www.example.com/
1652 features/news.html, etc.
1654 Or, you can designate sites as trusted referrers, by prepending the name
1655 with a + character. The effect is that access to untrusted sites will be
1656 granted -- but only if a link from this trusted referrer was used to get
1657 there. The link target will then be added to the "trustfile" so that
1658 future, direct accesses will be granted. Sites added via this mechanism do
1659 not become trusted referrers themselves (i.e. they are added with a ~
1660 designation). There is a limit of 512 such entries, after which new entries
1663 If you use the + operator in the trust file, it may grow considerably over
1666 It is recommended that Privoxy be compiled with the --disable-force,
1667 --disable-toggle and --disable-editor options, if this feature is to be
1670 Possible applications include limiting Internet access for children.
1672 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1676 These options are mainly useful when tracing a problem. Note that you might
1677 also want to invoke Privoxy with the --no-daemon command line option when
1680 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1686 Key values that determine what information gets logged to the logfile.
1694 12289 (i.e.: URLs plus informational and warning messages)
1698 Nothing gets logged.
1702 The available debug levels are:
1704 debug 1 # show each GET/POST/CONNECT request
1705 debug 2 # show each connection status
1706 debug 4 # show I/O status
1707 debug 8 # show header parsing
1708 debug 16 # log all data written to the network into the logfile
1709 debug 32 # debug force feature
1710 debug 64 # debug regular expression filters
1711 debug 128 # debug redirects
1712 debug 256 # debug GIF de-animation
1713 debug 512 # Common Log Format
1714 debug 1024 # debug kill pop-ups
1715 debug 2048 # CGI user interface
1716 debug 4096 # Startup banner and warnings.
1717 debug 8192 # Non-fatal errors
1720 To select multiple debug levels, you can either add them or use multiple
1723 A debug level of 1 is informative because it will show you each request as
1724 it happens. 1, 4096 and 8192 are highly recommended so that you will notice
1725 when things go wrong. The other levels are probably only of interest if you
1726 are hunting down a specific problem. They can produce a hell of an output
1729 If you want to use CLF (Common Log Format), you should set "debug 512" ONLY
1730 and not enable anything else.
1732 Privoxy has a hard-coded limit for the length of log messages. If it's
1733 reached, messages are logged truncated and marked with "... [too long,
1736 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1738 7.3.2. single-threaded
1742 Whether to run only one server thread.
1754 Multi-threaded (or, where unavailable: forked) operation, i.e. the ability
1755 to serve multiple requests simultaneously.
1759 This option is only there for debugging purposes. It will drastically
1762 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1764 7.4. Access Control and Security
1766 This section of the config file controls the security-relevant aspects of
1767 Privoxy's configuration.
1769 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1771 7.4.1. listen-address
1775 The IP address and TCP port on which Privoxy will listen for client
1788 Bind to 127.0.0.1 (localhost), port 8118. This is suitable and recommended
1789 for home users who run Privoxy on the same machine as their browser.
1793 You will need to configure your browser(s) to this proxy address and port.
1795 If you already have another service running on port 8118, or if you want to
1796 serve requests from other machines (e.g. on your local network) as well,
1797 you will need to override the default.
1799 If you leave out the IP address, Privoxy will bind to all interfaces
1800 (addresses) on your machine and may become reachable from the Internet. In
1801 that case, consider using access control lists (ACL's, see below), and/or a
1804 If you open Privoxy to untrusted users, you will also want to make sure
1805 that the following actions are disabled: enable-edit-actions and
1806 enable-remote-toggle
1810 Suppose you are running Privoxy on a machine which has the address
1811 192.168.0.1 on your local private network (192.168.0.0) and has another
1812 outside connection with a different address. You want it to serve requests
1815 listen-address 192.168.0.1:8118
1818 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1824 Initial state of "toggle" status
1836 Act as if toggled on
1840 If set to 0, Privoxy will start in "toggled off" mode, i.e. mostly behave
1841 like a normal, content-neutral proxy with both ad blocking and content
1842 filtering disabled. See enable-remote-toggle below.
1844 The windows version will only display the toggle icon in the system tray if
1845 this option is present.
1847 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1849 7.4.3. enable-remote-toggle
1853 Whether or not the web-based toggle feature may be used
1865 The web-based toggle feature is disabled.
1869 When toggled off, Privoxy mostly acts like a normal, content-neutral proxy,
1870 i.e. doesn't block ads or filter content.
1872 Access to the toggle feature can not be controlled separately by "ACLs" or
1873 HTTP authentication, so that everybody who can access Privoxy (see "ACLs"
1874 and listen-address above) can toggle it for all users. So this option is
1875 not recommended for multi-user environments with untrusted users.
1877 Note that malicious client side code (e.g Java) is also capable of using
1880 As a lot of Privoxy users don't read documentation, this feature is
1881 disabled by default.
1883 Note that you must have compiled Privoxy with support for this feature,
1884 otherwise this option has no effect.
1886 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1888 7.4.4. enable-remote-http-toggle
1892 Whether or not Privoxy recognizes special HTTP headers to change its
1905 Privoxy ignores special HTTP headers.
1909 When toggled on, the client can change Privoxy's behaviour by setting
1910 special HTTP headers. Currently the only supported special header is
1911 "X-Filter: No", to disable filtering for the ongoing request, even if it is
1912 enabled in one of the action files.
1914 This feature is disabled by default. If you are using Privoxy in a
1915 environment with trusted clients, you may enable this feature at your
1916 discretion. Note that malicious client side code (e.g Java) is also capable
1917 of using this feature.
1919 This option will be removed in future releases as it has been obsoleted by
1920 the more general header taggers.
1922 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1924 7.4.5. enable-edit-actions
1928 Whether or not the web-based actions file editor may be used
1940 The web-based actions file editor is disabled.
1944 Access to the editor can not be controlled separately by "ACLs" or HTTP
1945 authentication, so that everybody who can access Privoxy (see "ACLs" and
1946 listen-address above) can modify its configuration for all users.
1948 This option is not recommended for environments with untrusted users and as
1949 a lot of Privoxy users don't read documentation, this feature is disabled
1952 Note that malicious client side code (e.g Java) is also capable of using
1953 the actions editor and you shouldn't enable this options unless you
1954 understand the consequences and are sure your browser is configured
1957 Note that you must have compiled Privoxy with support for this feature,
1958 otherwise this option has no effect.
1960 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1962 7.4.6. enforce-blocks
1966 Whether the user is allowed to ignore blocks and can "go there anyway".
1978 Blocks are not enforced.
1982 Privoxy is mainly used to block and filter requests as a service to the
1983 user, for example to block ads and other junk that clogs the pipes.
1984 Privoxy's configuration isn't perfect and sometimes innocent pages are
1985 blocked. In this situation it makes sense to allow the user to enforce the
1986 request and have Privoxy ignore the block.
1988 In the default configuration Privoxy's "Blocked" page contains a "go there
1989 anyway" link to adds a special string (the force prefix) to the request
1990 URL. If that link is used, Privoxy will detect the force prefix, remove it
1991 again and let the request pass.
1993 Of course Privoxy can also be used to enforce a network policy. In that
1994 case the user obviously should not be able to bypass any blocks, and that's
1995 what the "enforce-blocks" option is for. If it's enabled, Privoxy hides the
1996 "go there anyway" link. If the user adds the force prefix by hand, it will
1997 not be accepted and the circumvention attempt is logged.
2003 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2005 7.4.7. ACLs: permit-access and deny-access
2009 Who can access what.
2013 src_addr[/src_masklen] [dst_addr[/dst_masklen]]
2015 Where src_addr and dst_addr are IP addresses in dotted decimal notation or
2016 valid DNS names, and src_masklen and dst_masklen are subnet masks in CIDR
2017 notation, i.e. integer values from 2 to 30 representing the length (in
2018 bits) of the network address. The masks and the whole destination part are
2027 Don't restrict access further than implied by listen-address
2031 Access controls are included at the request of ISPs and systems
2032 administrators, and are not usually needed by individual users. For a
2033 typical home user, it will normally suffice to ensure that Privoxy only
2034 listens on the localhost (127.0.0.1) or internal (home) network address by
2035 means of the listen-address option.
2037 Please see the warnings in the FAQ that Privoxy is not intended to be a
2038 substitute for a firewall or to encourage anyone to defer addressing basic
2039 security weaknesses.
2041 Multiple ACL lines are OK. If any ACLs are specified, Privoxy only talks to
2042 IP addresses that match at least one permit-access line and don't match any
2043 subsequent deny-access line. In other words, the last match wins, with the
2044 default being deny-access.
2046 If Privoxy is using a forwarder (see forward below) for a particular
2047 destination URL, the dst_addr that is examined is the address of the
2048 forwarder and NOT the address of the ultimate target. This is necessary
2049 because it may be impossible for the local Privoxy to determine the IP
2050 address of the ultimate target (that's often what gateways are used for).
2052 You should prefer using IP addresses over DNS names, because the address
2053 lookups take time. All DNS names must resolve! You can not use domain
2054 patterns like "*.org" or partial domain names. If a DNS name resolves to
2055 multiple IP addresses, only the first one is used.
2057 Denying access to particular sites by ACL may have undesired side effects
2058 if the site in question is hosted on a machine which also hosts other sites
2063 Explicitly define the default behavior if no ACL and listen-address are
2064 set: "localhost" is OK. The absence of a dst_addr implies that all
2065 destination addresses are OK:
2067 permit-access localhost
2070 Allow any host on the same class C subnet as www.privoxy.org access to
2071 nothing but www.example.com (or other domains hosted on the same system):
2073 permit-access www.privoxy.org/24 www.example.com/32
2076 Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere,
2077 with the exception that 192.168.45.73 may not access the IP address behind
2078 www.dirty-stuff.example.com:
2080 permit-access 192.168.45.64/26
2081 deny-access 192.168.45.73 www.dirty-stuff.example.com
2084 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2090 Maximum size of the buffer for content filtering.
2102 Use a 4MB (4096 KB) limit.
2106 For content filtering, i.e. the +filter and +deanimate-gif actions, it is
2107 necessary that Privoxy buffers the entire document body. This can be
2108 potentially dangerous, since a server could just keep sending data
2109 indefinitely and wait for your RAM to exhaust -- with nasty consequences.
2112 When a document buffer size reaches the buffer-limit, it is flushed to the
2113 client unfiltered and no further attempt to filter the rest of the document
2114 is made. Remember that there may be multiple threads running, which might
2115 require up to buffer-limit Kbytes each, unless you have enabled
2116 "single-threaded" above.
2118 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2122 This feature allows routing of HTTP requests through a chain of multiple
2125 Forwarding can be used to chain Privoxy with a caching proxy to speed up
2126 browsing. Using a parent proxy may also be necessary if the machine that
2127 Privoxy runs on has no direct Internet access.
2129 Note that parent proxies can severely decrease your privacy level. For example
2130 a parent proxy could add your IP address to the request headers and if it's a
2131 caching proxy it may add the "Etag" header to revalidation requests again, even
2132 though you configured Privoxy to remove it. It may also ignore Privoxy's header
2133 time randomization and use the original values which could be used by the
2134 server as cookie replacement to track your steps between visits.
2136 Also specified here are SOCKS proxies. Privoxy supports the SOCKS 4 and SOCKS
2139 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2145 To which parent HTTP proxy specific requests should be routed.
2149 target_pattern http_parent[:port]
2151 where target_pattern is a URL pattern that specifies to which requests
2152 (i.e. URLs) this forward rule shall apply. Use / to denote "all URLs".
2153 http_parent[:port] is the DNS name or IP address of the parent HTTP proxy
2154 through which the requests should be forwarded, optionally followed by its
2155 listening port (default: 8080). Use a single dot (.) to denote "no
2164 Don't use parent HTTP proxies.
2168 If http_parent is ".", then requests are not forwarded to another HTTP
2169 proxy but are made directly to the web servers.
2171 Multiple lines are OK, they are checked in sequence, and the last match
2176 Everything goes to an example parent proxy, except SSL on port 443 (which
2179 forward / parent-proxy.example.org:8080
2183 Everything goes to our example ISP's caching proxy, except for requests to
2186 forward / caching-proxy.isp.example.net:8000
2187 forward .isp.example.net .
2190 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2192 7.5.2. forward-socks4 and forward-socks4a
2196 Through which SOCKS proxy (and optionally to which parent HTTP proxy)
2197 specific requests should be routed.
2201 target_pattern socks_proxy[:port] http_parent[:port]
2203 where target_pattern is a URL pattern that specifies to which requests
2204 (i.e. URLs) this forward rule shall apply. Use / to denote "all URLs".
2205 http_parent and socks_proxy are IP addresses in dotted decimal notation or
2206 valid DNS names (http_parent may be "." to denote "no HTTP forwarding"),
2207 and the optional port parameters are TCP ports, i.e. integer values from 1
2216 Don't use SOCKS proxies.
2220 Multiple lines are OK, they are checked in sequence, and the last match
2223 The difference between forward-socks4 and forward-socks4a is that in the
2224 SOCKS 4A protocol, the DNS resolution of the target hostname happens on the
2225 SOCKS server, while in SOCKS 4 it happens locally.
2227 If http_parent is ".", then requests are not forwarded to another HTTP
2228 proxy but are made (HTTP-wise) directly to the web servers, albeit through
2233 From the company example.com, direct connections are made to all "internal"
2234 domains, but everything outbound goes through their ISP's proxy by way of
2235 example.com's corporate SOCKS 4A gateway to the Internet.
2237 forward-socks4a / socks-gw.example.com:1080 www-cache.isp.example.net:8080
2238 forward .example.com .
2241 A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent
2244 forward-socks4 / socks-gw.example.com:1080 .
2247 To chain Privoxy and Tor, both running on the same system, you would use
2250 forward-socks4a / 127.0.0.1:9050 .
2253 The public Tor network can't be used to reach your local network, if you
2254 need to access local servers you therefore might want to make some
2257 forward 192.168.*.*/ .
2259 forward 127.*.*.*/ .
2262 Unencrypted connections to systems in these address ranges will be as (un)
2263 secure as the local network is, but the alternative is that you can't reach
2264 the local network through Privoxy at all. Of course this may actually be
2265 desired and there is no reason to make these exceptions if you aren't sure
2268 If you also want to be able to reach servers in your local network by using
2269 their names, you will need additional exceptions that look like this:
2271 forward localhost/ .
2274 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2276 7.5.3. Advanced Forwarding Examples
2278 If you have links to multiple ISPs that provide various special content only to
2279 their subscribers, you can configure multiple Privoxies which have connections
2280 to the respective ISPs to act as forwarders to each other, so that your users
2281 can see the internal content of all ISPs.
2283 Assume that host-a has a PPP connection to isp-a.example.net. And host-b has a
2284 PPP connection to isp-b.example.org. Both run Privoxy. Their forwarding
2285 configuration can look like this:
2290 forward .isp-b.example.net host-b:8118
2296 forward .isp-a.example.org host-a:8118
2299 Now, your users can set their browser's proxy to use either host-a or host-b
2300 and be able to browse the internal content of both isp-a and isp-b.
2302 If you intend to chain Privoxy and squid locally, then chaining as browser ->
2303 squid -> privoxy is the recommended way.
2305 Assuming that Privoxy and squid run on the same box, your squid configuration
2306 could then look like this:
2308 # Define Privoxy as parent proxy (without ICP)
2309 cache_peer 127.0.0.1 parent 8118 7 no-query
2311 # Define ACL for protocol FTP
2314 # Do not forward FTP requests to Privoxy
2315 always_direct allow ftp
2317 # Forward all the rest to Privoxy
2318 never_direct allow all
2321 You would then need to change your browser's proxy settings to squid's address
2322 and port. Squid normally uses port 3128. If unsure consult http_port in
2325 You could just as well decide to only forward requests you suspect of leading
2326 to Windows executables through a virus-scanning parent proxy, say, on
2327 antivir.example.com, port 8010:
2330 forward /.*\.(exe|com|dll|zip)$ antivir.example.com:8010
2333 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2335 7.5.4. forwarded-connect-retries
2339 How often Privoxy retries if a forwarded connection request fails.
2351 Connections forwarded through other proxies are treated like direct
2352 connections and no retry attempts are made.
2356 forwarded-connect-retries is mainly interesting for socks4a connections,
2357 where Privoxy can't detect why the connections failed. The connection might
2358 have failed because of a DNS timeout in which case a retry makes sense, but
2359 it might also have failed because the server doesn't exist or isn't
2360 reachable. In this case the retry will just delay the appearance of
2361 Privoxy's error message.
2363 Note that in the context of this option, "forwarded connections" includes
2364 all connections that Privoxy forwards through other proxies. This option is
2365 not limited to the HTTP CONNECT method.
2367 Only use this option, if you are getting lots of forwarding-related error
2368 messages that go away when you try again manually. Start with a small value
2369 and check Privoxy's logfile from time to time, to see how many retries are
2374 forwarded-connect-retries 1
2376 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2378 7.5.5. accept-intercepted-requests
2382 Whether intercepted requests should be treated as valid.
2394 Only proxy requests are accepted, intercepted requests are treated as
2399 If you don't trust your clients and want to force them to use Privoxy,
2400 enable this option and configure your packet filter to redirect outgoing
2401 HTTP connections into Privoxy.
2403 Make sure that Privoxy's own requests aren't redirected as well.
2404 Additionally take care that Privoxy can't intentionally connect to itself,
2405 otherwise you could run into redirection loops if Privoxy's listening port
2406 is reachable by the outside or an attacker has access to the pages you
2411 accept-intercepted-requests 1
2413 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2415 7.5.6. allow-cgi-request-crunching
2419 Whether requests to Privoxy's CGI pages can be blocked or redirected.
2431 Privoxy ignores block and redirect actions for its CGI pages.
2435 By default Privoxy ignores block or redirect actions for its CGI pages.
2436 Intercepting these requests can be useful in multi-user setups to implement
2437 fine-grained access control, but it can also render the complete web
2438 interface useless and make debugging problems painful if done without care.
2440 Don't enable this option unless you're sure that you really need it.
2444 allow-cgi-request-crunching 1
2446 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2448 7.5.7. split-large-forms
2452 Whether the CGI interface should stay compatible with broken HTTP clients.
2464 The CGI form generate long GET URLs.
2468 Privoxy's CGI forms can lead to rather long URLs. This isn't a problem as
2469 far as the HTTP standard is concerned, but it can confuse clients with
2470 arbitrary URL length limitations.
2472 Enabling split-large-forms causes Privoxy to divide big forms into smaller
2473 ones to keep the URL length down. It makes editing a lot less convenient
2474 and you can no longer submit all changes at once, but at least it works
2475 around this browser bug.
2477 If you don't notice any editing problems, there is no reason to enable this
2478 option, but if one of the submit buttons appears to be broken, you should
2485 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2487 7.6. Windows GUI Options
2489 Privoxy has a number of options specific to the Windows GUI interface:
2491 If "activity-animation" is set to 1, the Privoxy icon will animate when
2492 "Privoxy" is active. To turn off, set to 0.
2494 activity-animation 1
2497 If "log-messages" is set to 1, Privoxy will log messages to the console window:
2502 If "log-buffer-size" is set to 1, the size of the log buffer, i.e. the amount
2503 of memory used for the log messages displayed in the console window, will be
2504 limited to "log-max-lines" (see below).
2506 Warning: Setting this to 0 will result in the buffer to grow infinitely and eat
2512 log-max-lines is the maximum number of lines held in the log buffer. See above.
2517 If "log-highlight-messages" is set to 1, Privoxy will highlight portions of the
2518 log messages with a bold-faced font:
2520 log-highlight-messages 1
2523 The font used in the console window:
2525 log-font-name Comic Sans MS
2528 Font size used in the console window:
2533 "show-on-task-bar" controls whether or not Privoxy will appear as a button on
2534 the Task bar when minimized:
2539 If "close-button-minimizes" is set to 1, the Windows close button will minimize
2540 Privoxy instead of closing the program (close with the exit option on the File
2543 close-button-minimizes 1
2546 The "hide-console" option is specific to the MS-Win console version of Privoxy.
2547 If this option is used, Privoxy will disconnect from and hide the command
2553 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2557 The actions files are used to define what actions Privoxy takes for which URLs,
2558 and thus determines how ad images, cookies and various other aspects of HTTP
2559 content and transactions are handled, and on which sites (or even parts
2560 thereof). There are a number of such actions, with a wide range of
2561 functionality. Each action does something a little different. These actions
2562 give us a veritable arsenal of tools with which to exert our control,
2563 preferences and independence. Actions can be combined so that their effects are
2564 aggregated when applied against a given set of URLs.
2566 There are three action files included with Privoxy with differing purposes:
2568 • default.action - is the primary action file that sets the initial values
2569 for all actions. It is intended to provide a base level of functionality
2570 for Privoxy's array of features. So it is a set of broad rules that should
2571 work reasonably well as-is for most users. This is the file that the
2572 developers are keeping updated, and making available to users. The user's
2573 preferences as set in standard.action, e.g. either Cautious (the default),
2574 Medium, or Advanced (see below).
2576 • user.action - is intended to be for local site preferences and exceptions.
2577 As an example, if your ISP or your bank has specific requirements, and need
2578 special handling, this kind of thing should go here. This file will not be
2581 • standard.action - is used only by the web based editor at http://
2582 config.privoxy.org/edit-actions-list?f=default, to set various pre-defined
2583 sets of rules for the default actions section in default.action.
2585 Edit Set to Cautious Set to Medium Set to Advanced
2587 These have increasing levels of aggressiveness and have no influence on
2588 your browsing unless you select them explicitly in the editor. A default
2589 installation should be pre-set to Cautious (versions prior to 3.0.5 were
2590 set to Medium). New users should try this for a while before adjusting the
2591 settings to more aggressive levels. The more aggressive the settings, then
2592 the more likelihood there is of problems such as sites not working as they
2595 The Edit button allows you to turn each action on/off individually for
2596 fine-tuning. The Cautious button changes the actions list to low/safe
2597 settings which will activate ad blocking and a minimal set of Privoxy's
2598 features, and subsequently there will be less of a chance for accidental
2599 problems. The Medium button sets the list to a medium level of other
2600 features and a low level set of privacy features. The Advanced button sets
2601 the list to a high level of ad blocking and medium level of privacy. See
2602 the chart below. The latter three buttons over-ride any changes via with
2603 the Edit button. More fine-tuning can be done in the lower sections of this
2606 It is not recommend to edit the standard.action file itself.
2608 The default profiles, and their associated actions, as pre-defined in
2609 standard.action are:
2611 Table 1. Default Configurations
2613 ┌──────────────────────────┬───────────┬────────────┬───────────┐
2614 │ Feature │ Cautious │ Medium │ Advanced │
2615 ├──────────────────────────┼───────────┼────────────┼───────────┤
2616 │Ad-blocking Aggressiveness│medium │high │high │
2617 ├──────────────────────────┼───────────┼────────────┼───────────┤
2618 │Ad-filtering by size │no │yes │yes │
2619 ├──────────────────────────┼───────────┼────────────┼───────────┤
2620 │Ad-filtering by link │no │no │yes │
2621 ├──────────────────────────┼───────────┼────────────┼───────────┤
2622 │Pop-up killing │blocks only│blocks only │blocks only│
2623 ├──────────────────────────┼───────────┼────────────┼───────────┤
2624 │Privacy Features │low │medium │medium/high│
2625 ├──────────────────────────┼───────────┼────────────┼───────────┤
2626 │Cookie handling │none │session-only│kill │
2627 ├──────────────────────────┼───────────┼────────────┼───────────┤
2628 │Referer forging │no │yes │yes │
2629 ├──────────────────────────┼───────────┼────────────┼───────────┤
2630 │GIF de-animation │no │yes │yes │
2631 ├──────────────────────────┼───────────┼────────────┼───────────┤
2632 │Fast redirects │no │no │yes │
2633 ├──────────────────────────┼───────────┼────────────┼───────────┤
2634 │HTML taming │no │no │yes │
2635 ├──────────────────────────┼───────────┼────────────┼───────────┤
2636 │JavaScript taming │no │no │yes │
2637 ├──────────────────────────┼───────────┼────────────┼───────────┤
2638 │Web-bug killing │no │yes │yes │
2639 ├──────────────────────────┼───────────┼────────────┼───────────┤
2640 │Image tag reordering │no │no │yes │
2641 └──────────────────────────┴───────────┴────────────┴───────────┘
2643 The list of actions files to be used are defined in the main configuration
2644 file, and are processed in the order they are defined (e.g. default.action is
2645 typically processed before user.action). The content of these can all be viewed
2646 and edited from http://config.privoxy.org/show-status. The over-riding
2647 principle when applying actions, is that the last action that matches a given
2648 URL wins. The broadest, most general rules go first (defined in
2649 default.action), followed by any exceptions (typically also in default.action),
2650 which are then followed lastly by any local preferences (typically in
2651 user.action). Generally, user.action has the last word.
2653 An actions file typically has multiple sections. If you want to use "aliases"
2654 in an actions file, you have to place the (optional) alias section at the top
2655 of that file. Then comes the default set of rules which will apply universally
2656 to all sites and pages (be very careful with using such a universal set in
2657 user.action or any other actions file after default.action, because it will
2658 override the result from consulting any previous file). And then below that,
2659 exceptions to the defined universal policies. You can regard user.action as an
2660 appendix to default.action, with the advantage that it is a separate file,
2661 which makes preserving your personal settings across Privoxy upgrades easier.
2663 Actions can be used to block anything you want, including ads, banners, or just
2664 some obnoxious URL whose content you would rather not see. Cookies can be
2665 accepted or rejected, or accepted only during the current browser session (i.e.
2666 not written to disk), content can be modified, some JavaScripts tamed,
2667 user-tracking fooled, and much more. See below for a complete list of actions.
2669 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2671 8.1. Finding the Right Mix
2673 Note that some actions, like cookie suppression or script disabling, may render
2674 some sites unusable that rely on these techniques to work properly. Finding the
2675 right mix of actions is not always easy and certainly a matter of personal
2676 taste. And, things can always change, requiring refinements in the
2677 configuration. In general, it can be said that the more "aggressive" your
2678 default settings (in the top section of the actions file) are, the more
2679 exceptions for "trusted" sites you will have to make later. If, for example,
2680 you want to crunch all cookies per default, you'll have to make exceptions from
2681 that rule for sites that you regularly use and that require cookies for
2682 actually useful purposes, like maybe your bank, favorite shop, or newspaper.
2684 We have tried to provide you with reasonable rules to start from in the
2685 distribution actions files. But there is no general rule of thumb on these
2686 things. There just are too many variables, and sites are constantly changing.
2687 Sooner or later you will want to change the rules (and read this chapter again
2690 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2694 The easiest way to edit the actions files is with a browser by using our
2695 browser-based editor, which can be reached from http://config.privoxy.org/
2696 show-status. Note: the config file option enable-edit-actions must be enabled
2697 for this to work. The editor allows both fine-grained control over every single
2698 feature on a per-URL basis, and easy choosing from wholesale sets of defaults
2699 like "Cautious", "Medium" or "Advanced". Warning: the "Advanced" setting is
2700 more aggressive, and will be more likely to cause problems for some sites.
2701 Experienced users only!
2703 If you prefer plain text editing to GUIs, you can of course also directly edit
2704 the the actions files with your favorite text editor. Look at default.action
2705 which is richly commented with many good examples.
2707 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2709 8.3. How Actions are Applied to Requests
2711 Actions files are divided into sections. There are special sections, like the "
2712 alias" sections which will be discussed later. For now let's concentrate on
2713 regular sections: They have a heading line (often split up to multiple lines
2714 for readability) which consist of a list of actions, separated by whitespace
2715 and enclosed in curly braces. Below that, there is a list of URL and tag
2716 patterns, each on a separate line.
2718 To determine which actions apply to a request, the URL of the request is
2719 compared to all URL patterns in each "action file". Every time it matches, the
2720 list of applicable actions for the request is incrementally updated, using the
2721 heading of the section in which the pattern is located. The same is done again
2722 for tags and tag patterns later on.
2724 If multiple applying sections set the same action differently, the last match
2725 wins. If not, the effects are aggregated. E.g. a URL might match a regular
2726 section with a heading line of { +handle-as-image }, then later another one
2727 with just { +block }, resulting in both actions to apply. And there may well be
2728 cases where you will want to combine actions together. Such a section then
2731 { +handle-as-image +block }
2732 # Block these as if they were images. Send no block page.
2734 media.example.com/.*banners
2735 .example.com/images/ads/
2738 You can trace this process for URL patterns and any given URL by visiting http:
2739 //config.privoxy.org/show-url-info.
2741 Examples and more detail on this is provided in the Appendix, Troubleshooting:
2742 Anatomy of an Action section.
2744 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2748 As mentioned, Privoxy uses "patterns" to determine what actions might apply to
2749 which sites and pages your browser attempts to access. These "patterns" use
2750 wild card type pattern matching to achieve a high degree of flexibility. This
2751 allows one expression to be expanded and potentially match against many similar
2754 Generally, an URL pattern has the form <domain>/<path>, where both the <domain>
2755 and <path> are optional. (This is why the special / pattern matches all URLs).
2756 Note that the protocol portion of the URL pattern (e.g. http://) should not be
2757 included in the pattern. This is assumed already!
2759 The pattern matching syntax is different for the domain and path parts of the
2760 URL. The domain part uses a simple globbing type matching technique, while the
2761 path part uses a more flexible "Regular Expressions (PCRE)" based syntax.
2765 is a domain-only pattern and will match any request to www.example.com,
2766 regardless of which document on that server is requested. So ALL pages in
2767 this domain would be covered by the scope of this action. Note that a
2768 simple example.com is different and would NOT match.
2772 means exactly the same. For domain-only patterns, the trailing / may be
2775 www.example.com/index.html$
2777 matches all the documents on www.example.com whose name starts with /
2780 www.example.com/index.html$
2782 matches only the single document /index.html on www.example.com.
2786 matches the document /index.html, regardless of the domain, i.e. on any web
2791 matches nothing, since it would be interpreted as a domain name and there
2792 is no top-level domain called .html. So its a mistake.
2794 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2796 8.4.1. The Domain Pattern
2798 The matching of the domain part offers some flexible options: if the domain
2799 starts or ends with a dot, it becomes unanchored at that end. For example:
2803 matches any domain that ENDS in .example.com
2807 matches any domain that STARTS with www.
2811 matches any domain that CONTAINS .example.. And, by the way, also included
2812 would be any files or documents that exist within that domain since no path
2813 limitations are specified. (Correctly speaking: It matches any FQDN that
2814 contains example as a domain.) This might be www.example.com,
2815 news.example.de, or www.example.net/cgi/testing.pl for instance. All these
2818 Additionally, there are wild-cards that you can use in the domain names
2819 themselves. These work similarly to shell globbing type wild-cards: "*"
2820 represents zero or more arbitrary characters (this is equivalent to the
2821 "Regular Expression" based syntax of ".*"), "?" represents any single character
2822 (this is equivalent to the regular expression syntax of a simple "."), and you
2823 can define "character classes" in square brackets which is similar to the same
2824 regular expression technique. All of this can be freely mixed:
2828 matches "adserver.example.com", "ads.example.com", etc but not
2833 matches all of the above, and then some.
2837 matches www.ipix.com, pictures.epix.com, a.b.c.d.e.upix.com etc.
2839 www[1-9a-ez].example.c*
2841 matches www1.example.com, www4.example.cc, wwwd.example.cy,
2842 wwwz.example.com etc., but not wwww.example.com.
2844 While flexible, this is not the sophistication of full regular expression based
2847 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2849 8.4.2. The Path Pattern
2851 Privoxy uses Perl compatible (PCRE) "Regular Expression" based syntax (through
2852 the PCRE library) for matching the path portion (after the slash), and is thus
2855 There is an Appendix with a brief quick-start into regular expressions, and
2856 full (very technical) documentation on PCRE regex syntax is available on-line
2857 at http://www.pcre.org/man.txt. You might also find the Perl man page on
2858 regular expressions (man perlre) useful, which is available on-line at http://
2859 perldoc.perl.org/perlre.html.
2861 Note that the path pattern is automatically left-anchored at the "/", i.e. it
2862 matches as if it would start with a "^" (regular expression speak for the
2863 beginning of a line).
2865 Please also note that matching in the path is CASE INSENSITIVE by default, but
2866 you can switch to case sensitive at any point in the pattern by using the "(?
2867 -i)" switch: www.example.com/(?-i)PaTtErN.* will match only documents whose
2868 path starts with PaTtErN in exactly this capitalization.
2872 Is equivalent to just ".example.com", since any documents within that
2873 domain are matched with or without the ".*" regular expression. This is
2876 .example.com/.*/index.html$
2878 Will match any page in the domain of "example.com" that is named
2879 "index.html", and that is part of some path. For example, it matches
2880 "www.example.com/testing/index.html" but NOT "www.example.com/index.html"
2881 because the regular expression called for at least two "/'s", thus the path
2882 requirement. It also would match "www.example.com/testing/index_html",
2883 because of the special meta-character ".".
2885 .example.com/(.*/)?index\.html$
2887 This regular expression is conditional so it will match any page named
2888 "index.html" regardless of path which in this case can have one or more "/
2889 's". And this one must contain exactly ".html" (but does not have to end
2892 .example.com/(.*/)(ads|banners?|junk)
2894 This regular expression will match any path of "example.com" that contains
2895 any of the words "ads", "banner", "banners" (because of the "?") or "junk".
2896 The path does not have to end in these words, just contain them.
2898 .example.com/(.*/)(ads|banners?|junk)/.*\.(jpe?g|gif|png)$
2900 This is very much the same as above, except now it must end in either
2901 ".jpg", ".jpeg", ".gif" or ".png". So this one is limited to common image
2904 There are many, many good examples to be found in default.action, and more
2905 tutorials below in Appendix on regular expressions.
2907 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2909 8.4.3. The Tag Pattern
2911 Tag patterns are used to change the applying actions based on the request's
2912 tags. Tags can be created with either the client-header-tagger or the
2913 server-header-tagger action.
2915 Tag patterns have to start with "TAG:", so Privoxy can tell them apart from URL
2916 patterns. Everything after the colon including white space, is interpreted as a
2917 regular expression with path pattern syntax, except that tag patterns aren't
2918 left-anchored automatically (Privoxy doesn't silently add a "^", you have to do
2919 it yourself if you need it).
2921 To match all requests that are tagged with "foo" your pattern line should be
2922 "TAG:^foo$", "TAG:foo" would work as well, but it would also match requests
2923 whose tags contain "foo" somewhere. "TAG: foo" wouldn't work as it requires
2926 Sections can contain URL and tag patterns at the same time, but tag patterns
2927 are checked after the URL patterns and thus always overrule them, even if they
2928 are located before the URL patterns.
2930 Once a new tag is added, Privoxy checks right away if it's matched by one of
2931 the tag patterns and updates the action settings accordingly. As a result tags
2932 can be used to activate other tagger actions, as long as these other taggers
2933 look for headers that haven't already be parsed.
2935 For example you could tag client requests which use the POST method, then use
2936 this tag to activate another tagger that adds a tag if cookies are sent, and
2937 then use a block action based on the cookie tag. This allows the outcome of one
2938 action, to be input into a subsequent action. However if you'd reverse the
2939 position of the described taggers, and activated the method tagger based on the
2940 cookie tagger, no method tags would be created. The method tagger would look
2941 for the request line, but at the time the cookie tag is created, the request
2942 line has already been parsed.
2944 While this is a limitation you should be aware of, this kind of indirection is
2945 seldom needed anyway and even the example doesn't make too much sense.
2947 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2951 All actions are disabled by default, until they are explicitly enabled
2952 somewhere in an actions file. Actions are turned on if preceded with a "+", and
2953 turned off if preceded with a "-". So a +action means "do that action", e.g.
2954 +block means "please block URLs that match the following patterns", and -block
2955 means "don't block URLs that match the following patterns, even if +block
2956 previously applied."
2958 Again, actions are invoked by placing them on a line, enclosed in curly braces
2959 and separated by whitespace, like in {+some-action -some-other-action
2960 {some-parameter}}, followed by a list of URL patterns, one per line, to which
2961 they apply. Together, the actions line and the following pattern lines make up
2962 a section of the actions file.
2964 Actions fall into three categories:
2966 • Boolean, i.e the action can only be "enabled" or "disabled". Syntax:
2968 +name # enable action name
2969 -name # disable action name
2974 • Parameterized, where some value is required in order to enable this type of
2977 +name{param} # enable action and set parameter to param,
2978 # overwriting parameter from previous match if necessary
2979 -name # disable action. The parameter can be omitted
2982 Note that if the URL matches multiple positive forms of a parameterized
2983 action, the last match wins, i.e. the params from earlier matches are
2986 Example: +hide-user-agent{Mozilla/5.0 (X11; U; FreeBSD i386; en-US;
2987 rv:1.8.1.4) Gecko/20070602 Firefox/2.0.0.4}
2989 • Multi-value. These look exactly like parameterized actions, but they behave
2990 differently: If the action applies multiple times to the same URL, but with
2991 different parameters, all the parameters from all matches are remembered.
2992 This is used for actions that can be executed for the same request
2993 repeatedly, like adding multiple headers, or filtering through multiple
2996 +name{param} # enable action and add param to the list of parameters
2997 -name{param} # remove the parameter param from the list of parameters
2998 # If it was the last one left, disable the action.
2999 -name # disable this action completely and remove all parameters from the list
3002 Examples: +add-header{X-Fun-Header: Some text} and +filter{html-annoyances}
3004 If nothing is specified in any actions file, no "actions" are taken. So in this
3005 case Privoxy would just be a normal, non-blocking, non-filtering proxy. You
3006 must specifically enable the privacy and blocking features you need (although
3007 the provided default actions files will give a good starting point).
3009 Later defined action sections always over-ride earlier ones of the same type.
3010 So exceptions to any rules you make, should come in the latter part of the file
3011 (or in a file that is processed later when using multiple actions files such as
3012 user.action). For multi-valued actions, the actions are applied in the order
3013 they are specified. Actions files are processed in the order they are defined
3014 in config (the default installation has three actions files). It also quite
3015 possible for any given URL to match more than one "pattern" (because of
3016 wildcards and regular expressions), and thus to trigger more than one set of
3017 actions! Last match wins.
3019 The list of valid Privoxy actions are:
3021 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3027 Confuse log analysis, custom applications
3031 Sends a user defined HTTP header to the web server.
3039 Any string value is possible. Validity of the defined HTTP headers is not
3040 checked. It is recommended that you use the "X-" prefix for custom headers.
3044 This action may be specified multiple times, in order to define multiple
3045 headers. This is rarely needed for the typical user. If you don't know what
3046 "HTTP headers" are, you definitely don't need to worry about this one.
3050 +add-header{X-User-Tracking: sucks}
3053 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3059 Block ads or other unwanted content
3063 Requests for URLs to which this action applies are blocked, i.e. the
3064 requests are trapped by Privoxy and the requested URL is never retrieved,
3065 but is answered locally with a substitute page or image, as determined by
3066 the handle-as-image, set-image-blocker, and handle-as-empty-document
3079 Privoxy sends a special "BLOCKED" page for requests to blocked pages. This
3080 page contains links to find out why the request was blocked, and a
3081 click-through to the blocked content (the latter only if compiled with the
3082 force feature enabled). The "BLOCKED" page adapts to the available screen
3083 space -- it displays full-blown if space allows, or miniaturized and
3084 text-only if loaded into a small frame or window. If you are using Privoxy
3085 right now, you can take a look at the "BLOCKED" page.
3087 A very important exception occurs if both block and handle-as-image, apply
3088 to the same request: it will then be replaced by an image. If
3089 set-image-blocker (see below) also applies, the type of image will be
3090 determined by its parameter, if not, the standard checkerboard pattern is
3093 It is important to understand this process, in order to understand how
3094 Privoxy deals with ads and other unwanted content. Blocking is a core
3095 feature, and one upon which various other features depend.
3097 The filter action can perform a very similar task, by "blocking" banner
3098 images and other content through rewriting the relevant URLs in the
3099 document's HTML source, so they don't get requested in the first place.
3100 Note that this is a totally different technique, and it's easy to confuse
3103 Example usage (section):
3106 # Block and replace with "blocked" page
3107 .nasty-stuff.example.com
3109 {+block +handle-as-image}
3110 # Block and replace with image
3114 {+block +handle-as-empty-document}
3115 # Block and then ignore
3116 adserver.exampleclick.net/.*\.js$
3119 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3121 8.5.3. client-header-filter
3125 Rewrite or remove single client headers.
3129 All client headers to which this action applies are filtered on-the-fly
3130 through the specified regular expression based substitutions.
3138 The name of a client-header filter, as defined in one of the filter files.
3142 Client-header filters are applied to each header on its own, not to all at
3143 once. This makes it easier to diagnose problems, but on the downside you
3144 can't write filters that only change header x if header y's value is z. You
3145 can do that by using tags though.
3147 Client-header filters are executed after the other header actions have
3148 finished and use their output as input.
3150 If the request URL gets changed, Privoxy will detect that and use the new
3151 one. This can be used to rewrite the request destination behind the
3152 client's back, for example to specify a Tor exit relay for certain
3155 Please refer to the filter file chapter to learn which client-header
3156 filters are available by default, and how to create your own.
3158 Example usage (section):
3160 {+client-header-filter{hide-tor-exit-notation}}
3165 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3167 8.5.4. client-header-tagger
3171 Block requests based on their headers.
3175 Client headers to which this action applies are filtered on-the-fly through
3176 the specified regular expression based substitutions, the result is used as
3185 The name of a client-header tagger, as defined in one of the filter files.
3189 Client-header taggers are applied to each header on its own, and as the
3190 header isn't modified, each tagger "sees" the original.
3192 Client-header taggers are the first actions that are executed and their
3193 tags can be used to control every other action.
3195 Example usage (section):
3197 # Tag every request with the User-Agent header
3198 {+client-header-tagger{user-agent}}
3203 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3205 8.5.5. content-type-overwrite
3209 Stop useless download menus from popping up, or change the browser's
3214 Replaces the "Content-Type:" HTTP server header.
3226 The "Content-Type:" HTTP server header is used by the browser to decide
3227 what to do with the document. The value of this header can cause the
3228 browser to open a download menu instead of displaying the document by
3229 itself, even if the document's format is supported by the browser.
3231 The declared content type can also affect which rendering mode the browser
3232 chooses. If XHTML is delivered as "text/html", many browsers treat it as
3233 yet another broken HTML document. If it is send as "application/xml",
3234 browsers with XHTML support will only display it, if the syntax is correct.
3236 If you see a web site that proudly uses XHTML buttons, but sets
3237 "Content-Type: text/html", you can use Privoxy to overwrite it with
3238 "application/xml" and validate the web master's claim inside your
3239 XHTML-supporting browser. If the syntax is incorrect, the browser will
3242 You can also go the opposite direction: if your browser prints error
3243 messages instead of rendering a document falsely declared as XHTML, you can
3244 overwrite the content type with "text/html" and have it rendered as broken
3247 By default content-type-overwrite only replaces "Content-Type:" headers
3248 that look like some kind of text. If you want to overwrite it
3249 unconditionally, you have to combine it with force-text-mode. This
3250 limitation exists for a reason, think twice before circumventing it.
3252 Most of the time it's easier to replace this action with a custom
3253 server-header filter. It allows you to activate it for every document of a
3254 certain site and it will still only replace the content types you aimed at.
3256 Of course you can apply content-type-overwrite to a whole site and then
3257 make URL based exceptions, but it's a lot more work to get the same
3260 Example usage (sections):
3262 # Check if www.example.net/ really uses valid XHTML
3263 { +content-type-overwrite{application/xml} }
3266 # but leave the content type unmodified if the URL looks like a style sheet
3267 {-content-type-overwrite}
3268 www.example.net/.*\.css$
3269 www.example.net/.*style
3272 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3274 8.5.6. crunch-client-header
3278 Remove a client header Privoxy has no dedicated action for.
3282 Deletes every header sent by the client that contains the string the user
3283 supplied as parameter.
3295 This action allows you to block client headers for which no dedicated
3296 Privoxy action exists. Privoxy will remove every client header that
3297 contains the string you supplied as parameter.
3299 Regular expressions are not supported and you can't use this action to
3300 block different headers in the same request, unless they contain the same
3303 crunch-client-header is only meant for quick tests. If you have to block
3304 several different headers, or only want to modify parts of them, you should
3305 use a client-header filter.
3307 ┌─────────────────────────────────────────────────────────────────┐
3309 ├─────────────────────────────────────────────────────────────────┤
3310 │Don't block any header without understanding the consequences. │
3311 └─────────────────────────────────────────────────────────────────┘
3312 Example usage (section):
3314 # Block the non-existent "Privacy-Violation:" client header
3315 { +crunch-client-header{Privacy-Violation:} }
3320 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3322 8.5.7. crunch-if-none-match
3326 Prevent yet another way to track the user's steps between sessions.
3330 Deletes the "If-None-Match:" HTTP client header.
3342 Removing the "If-None-Match:" HTTP client header is useful for filter
3343 testing, where you want to force a real reload instead of getting status
3344 code "304" which would cause the browser to use a cached copy of the page.
3346 It is also useful to make sure the header isn't used as a cookie
3347 replacement (unlikely but possible).
3349 Blocking the "If-None-Match:" header shouldn't cause any caching problems,
3350 as long as the "If-Modified-Since:" header isn't blocked or missing as
3353 It is recommended to use this action together with hide-if-modified-since
3354 and overwrite-last-modified.
3356 Example usage (section):
3358 # Let the browser revalidate cached documents but don't
3359 # allow the server to use the revalidation headers for user tracking.
3360 {+hide-if-modified-since{-60} \
3361 +overwrite-last-modified{randomize} \
3362 +crunch-if-none-match}
3366 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3368 8.5.8. crunch-incoming-cookies
3372 Prevent the web server from setting HTTP cookies on your system
3376 Deletes any "Set-Cookie:" HTTP headers from server replies.
3388 This action is only concerned with incoming HTTP cookies. For outgoing HTTP
3389 cookies, use crunch-outgoing-cookies. Use both to disable HTTP cookies
3392 It makes no sense at all to use this action in conjunction with the
3393 session-cookies-only action, since it would prevent the session cookies
3394 from being set. See also filter-content-cookies.
3398 +crunch-incoming-cookies
3401 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3403 8.5.9. crunch-server-header
3407 Remove a server header Privoxy has no dedicated action for.
3411 Deletes every header sent by the server that contains the string the user
3412 supplied as parameter.
3424 This action allows you to block server headers for which no dedicated
3425 Privoxy action exists. Privoxy will remove every server header that
3426 contains the string you supplied as parameter.
3428 Regular expressions are not supported and you can't use this action to
3429 block different headers in the same request, unless they contain the same
3432 crunch-server-header is only meant for quick tests. If you have to block
3433 several different headers, or only want to modify parts of them, you should
3434 use a custom server-header filter.
3436 ┌─────────────────────────────────────────────────────────────────┐
3438 ├─────────────────────────────────────────────────────────────────┤
3439 │Don't block any header without understanding the consequences. │
3440 └─────────────────────────────────────────────────────────────────┘
3441 Example usage (section):
3443 # Crunch server headers that try to prevent caching
3444 { +crunch-server-header{no-cache} }
3448 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3450 8.5.10. crunch-outgoing-cookies
3454 Prevent the web server from reading any HTTP cookies from your system
3458 Deletes any "Cookie:" HTTP headers from client requests.
3470 This action is only concerned with outgoing HTTP cookies. For incoming HTTP
3471 cookies, use crunch-incoming-cookies. Use both to disable HTTP cookies
3474 It makes no sense at all to use this action in conjunction with the
3475 session-cookies-only action, since it would prevent the session cookies
3480 +crunch-outgoing-cookies
3483 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3485 8.5.11. deanimate-gifs
3489 Stop those annoying, distracting animated GIF images.
3493 De-animate GIF animations, i.e. reduce them to their first or last image.
3505 This will also shrink the images considerably (in bytes, not pixels!). If
3506 the option "first" is given, the first frame of the animation is used as
3507 the replacement. If "last" is given, the last frame of the animation is
3508 used instead, which probably makes more sense for most banner animations,
3509 but also has the risk of not showing the entire last frame (if it is only a
3510 delta to an earlier frame).
3512 You can safely use this action with patterns that will also match non-GIF
3513 objects, because no attempt will be made at anything that doesn't look like
3518 +deanimate-gifs{last}
3521 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3523 8.5.12. downgrade-http-version
3527 Work around (very rare) problems with HTTP/1.1
3531 Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0.
3543 This is a left-over from the time when Privoxy didn't support important
3544 HTTP/1.1 features well. It is left here for the unlikely case that you
3545 experience HTTP/1.1 related problems with some server out there. Not all
3546 HTTP/1.1 features and requirements are supported yet, so there is a chance
3547 you might need this action.
3549 Example usage (section):
3551 {+downgrade-http-version}
3552 problem-host.example.com
3555 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3557 8.5.13. fast-redirects
3561 Fool some click-tracking scripts and speed up indirect links.
3565 Detects redirection URLs and redirects the browser without contacting the
3566 redirection server first.
3574 □ "simple-check" to just search for the string "http://" to detect
3577 □ "check-decoded-url" to decode URLs (if necessary) before searching for
3582 Many sites, like yahoo.com, don't just link to other sites. Instead, they
3583 will link to some script on their own servers, giving the destination as a
3584 parameter, which will then redirect you to the final target. URLs resulting
3585 from this scheme typically look like: "http://www.example.org/
3586 click-tracker.cgi?target=http%3a//www.example.net/".
3588 Sometimes, there are even multiple consecutive redirects encoded in the
3589 URL. These redirections via scripts make your web browsing more traceable,
3590 since the server from which you follow such a link can see where you go to.
3591 Apart from that, valuable bandwidth and time is wasted, while your browser
3592 asks the server for one redirect after the other. Plus, it feeds the
3595 This feature is currently not very smart and is scheduled for improvement.
3596 If it is enabled by default, you will have to create some exceptions to
3597 this action. It can lead to failures in several ways:
3599 Not every URLs with other URLs as parameters is evil. Some sites offer a
3600 real service that requires this information to work. For example a
3601 validation service needs to know, which document to validate.
3602 fast-redirects assumes that every URL parameter that looks like another URL
3603 is a redirection target, and will always redirect to the last one. Most of
3604 the time the assumption is correct, but if it isn't, the user gets
3607 Another failure occurs if the URL contains other parameters after the URL
3608 parameter. The URL: "http://www.example.org/?redirect=http%3a//
3609 www.example.net/&foo=bar". contains the redirection URL "http://
3610 www.example.net/", followed by another parameter. fast-redirects doesn't
3611 know that and will cause a redirect to "http://www.example.net/&foo=bar".
3612 Depending on the target server configuration, the parameter will be
3613 silently ignored or lead to a "page not found" error. You can prevent this
3614 problem by first using the redirect action to remove the last part of the
3615 URL, but it requires a little effort.
3617 To detect a redirection URL, fast-redirects only looks for the string
3618 "http://", either in plain text (invalid but often used) or encoded as
3619 "http%3a//". Some sites use their own URL encoding scheme, encrypt the
3620 address of the target server or replace it with a database id. In theses
3621 cases fast-redirects is fooled and the request reaches the redirection
3622 server where it probably gets logged.
3626 { +fast-redirects{simple-check} }
3629 { +fast-redirects{check-decoded-url} }
3630 another.example.com/testing
3633 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3639 Get rid of HTML and JavaScript annoyances, banner advertisements (by size),
3640 do fun text replacements, add personalized effects, etc.
3644 All instances of text-based type, most notably HTML and JavaScript, to
3645 which this action applies, can be filtered on-the-fly through the specified
3646 regular expression based substitutions. (Note: as of version 3.0.3 plain
3647 text documents are exempted from filtering, because web servers often use
3648 the text/plain MIME type for all files whose type they don't know.)
3656 The name of a content filter, as defined in the filter file. Filters can be
3657 defined in one or more files as defined by the filterfile option in the
3658 config file. default.filter is the collection of filters supplied by the
3659 developers. Locally defined filters should go in their own file, such as
3662 When used in its negative form, and without parameters, all filtering is
3663 completely disabled.
3667 For your convenience, there are a number of pre-defined filters available
3668 in the distribution filter file that you can use. See the examples below
3671 Filtering requires buffering the page content, which may appear to slow
3672 down page rendering since nothing is displayed until all content has passed
3673 the filters. (It does not really take longer, but seems that way since the
3674 page is not incrementally displayed.) This effect will be more noticeable
3675 on slower connections.
3677 "Rolling your own" filters requires a knowledge of "Regular Expressions"
3678 and "HTML". This is very powerful feature, and potentially very intrusive.
3679 Filters should be used with caution, and where an equivalent "action" is
3682 The amount of data that can be filtered is limited to the buffer-limit
3683 option in the main config file. The default is 4096 KB (4 Megs). Once this
3684 limit is exceeded, the buffered data, and all pending data, is passed
3687 Inappropriate MIME types, such as zipped files, are not filtered at all.
3688 (Again, only text-based types except plain text). Encrypted SSL data (from
3689 HTTPS servers) cannot be filtered either, since this would violate the
3690 integrity of the secure transaction. In some situations it might be
3691 necessary to protect certain text, like source code, from filtering by
3692 defining appropriate -filter exceptions.
3694 Compressed content can't be filtered either, unless Privoxy is compiled
3695 with zlib support (requires at least Privoxy 3.0.7), in which case Privoxy
3696 will decompress the content before filtering it.
3698 If you use a Privoxy version without zlib support, but want filtering to
3699 work on as much documents as possible, even those that would normally be
3700 sent compressed, you must use the prevent-compression action in conjunction
3703 Content filtering can achieve some of the same effects as the block action,
3704 i.e. it can be used to block ads and banners. But the mechanism works quite
3705 differently. One effective use, is to block ad banners based on their size
3706 (see below), since many of these seem to be somewhat standardized.
3708 Feedback with suggestions for new or improved filters is particularly
3711 The below list has only the names and a one-line description of each
3712 predefined filter. There are more verbose explanations of what these
3713 filters do in the filter file chapter.
3715 Example usage (with filters from the distribution default.filter file). See the
3716 Predefined Filters section for more explanation on each:
3718 +filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse
3721 +filter{js-events} # Kill all JS event bindings (Radically destructive! Only for extra nasty sites)
3724 +filter{html-annoyances} # Get rid of particularly annoying HTML abuse
3727 +filter{content-cookies} # Kill cookies that come in the HTML or JS content
3730 +filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups)
3733 +filter{unsolicited-popups} # Disable only unsolicited pop-up windows. Useful if your browser lacks this ability.
3736 +filter{all-popups} # Kill all popups in JavaScript and HTML. Useful if your browser lacks this ability.
3739 +filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective
3742 +filter{banners-by-size} # Kill banners by size
3745 +filter{banners-by-link} # Kill banners by their links to known clicktrackers
3748 +filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking)
3751 +filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap
3754 +filter{jumping-windows} # Prevent windows from resizing and moving themselves
3757 +filter{frameset-borders} # Give frames a border and make them resizeable
3760 +filter{demoronizer} # Fix MS's non-standard use of standard charsets
3763 +filter{shockwave-flash} # Kill embedded Shockwave Flash objects
3766 +filter{quicktime-kioskmode} # Make Quicktime movies savable
3769 +filter{fun} # Text replacements for subversive browsing fun!
3772 +filter{crude-parental} # Crude parental filtering (demo only)
3775 +filter{ie-exploits} # Disable a known Internet Explorer bug exploits
3778 +filter{site-specifics} # Custom filters for specific site related problems
3781 +filter{google} # Removes text ads and other Google specific improvements
3784 +filter{yahoo} # Removes text ads and other Yahoo specific improvements
3787 +filter{msn} # Removes text ads and other MSN specific improvements
3790 +filter{blogspot} # Cleans up Blogspot blogs
3793 +filter{no-ping} # Removes non-standard ping attributes from anchor and area tags
3796 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3798 8.5.15. force-text-mode
3802 Force Privoxy to treat a document as if it was in some kind of text format.
3806 Declares a document as text, even if the "Content-Type:" isn't detected as
3819 As explained above, Privoxy tries to only filter files that are in some
3820 kind of text format. The same restrictions apply to content-type-overwrite.
3821 force-text-mode declares a document as text, without looking at the
3822 "Content-Type:" first.
3824 ┌─────────────────────────────────────────────────────────────────┐
3826 ├─────────────────────────────────────────────────────────────────┤
3827 │Think twice before activating this action. Filtering binary data │
3828 │with regular expressions can cause file damage. │
3829 └─────────────────────────────────────────────────────────────────┘
3836 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3838 8.5.16. forward-override
3842 Change the forwarding settings based on User-Agent or request origin
3846 Overrules the forward directives in the configuration file.
3854 □ "forward ." to use a direct connection without any additional proxies.
3856 □ "forward 127.0.0.1:8123" to use the HTTP proxy listening at 127.0.0.1
3859 □ "forward-socks4a 127.0.0.1:9050 ." to use the socks4a proxy listening
3860 at 127.0.0.1 port 9050. Replace "forward-socks4a" with "forward-socks4"
3861 to use a socks4 connection (with local DNS resolution) instead.
3863 □ "forward-socks4a 127.0.0.1:9050 proxy.example.org:8000" to use the
3864 socks4a proxy listening at 127.0.0.1 port 9050 to reach the HTTP proxy
3865 listening at proxy.example.org port 8000. Replace "forward-socks4a"
3866 with "forward-socks4" to use a socks4 connection (with local DNS
3867 resolution) instead.
3871 This action takes parameters similar to the forward directives in the
3872 configuration file, but without the URL pattern. It can be used as
3873 replacement, but normally it's only used in cases where matching based on
3874 the request URL isn't sufficient.
3876 ┌─────────────────────────────────────────────────────────────────┐
3878 ├─────────────────────────────────────────────────────────────────┤
3879 │Please read the description for the forward directives before │
3880 │using this action. Forwarding to the wrong people will reduce │
3881 │your privacy and increase the chances of man-in-the-middle │
3884 │If the ports are missing or invalid, default values will be used.│
3885 │This might change in the future and you shouldn't rely on it. │
3886 │Otherwise incorrect syntax causes Privoxy to exit. │
3888 │Use the show-url-info CGI page to verify that your forward │
3889 │settings do what you thought the do. │
3890 └─────────────────────────────────────────────────────────────────┘
3893 # Always use direct connections for requests previously tagged as
3894 # "User-Agent: fetch libfetch/2.0" and make sure
3895 # resuming downloads continues to work.
3896 # This way you can continue to use Tor for your normal browsing,
3897 # without overloading the Tor network with your FreeBSD ports updates
3898 # or downloads of bigger files like ISOs.
3899 # Note that HTTP headers are easy to fake and therefore their
3900 # values are as (un)trustworthy as your clients and users.
3901 {+forward-override{forward .} \
3902 -hide-if-modified-since \
3903 -overwrite-last-modified \
3905 TAG:^User-Agent: fetch libfetch/2\.0$
3909 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3911 8.5.17. handle-as-empty-document
3915 Mark URLs that should be replaced by empty documents if they get blocked
3919 This action alone doesn't do anything noticeable. It just marks URLs. If
3920 the block action also applies, the presence or absence of this mark decides
3921 whether an HTML "BLOCKED" page, or an empty document will be sent to the
3922 client as a substitute for the blocked content. The empty document isn't
3923 literally empty, but actually contains a single space.
3935 Some browsers complain about syntax errors if JavaScript documents are
3936 blocked with Privoxy's default HTML page; this option can be used to
3937 silence them. And of course this action can also be used to eliminate the
3938 Privoxy BLOCKED message in frames.
3940 The content type for the empty document can be specified with
3941 content-type-overwrite{}, but usually this isn't necessary.
3945 # Block all documents on example.org that end with ".js",
3946 # but send an empty document instead of the usual HTML message.
3947 {+block +handle-as-empty-document}
3952 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3954 8.5.18. handle-as-image
3958 Mark URLs as belonging to images (so they'll be replaced by images if they
3959 do get blocked, rather than HTML pages)
3963 This action alone doesn't do anything noticeable. It just marks URLs as
3964 images. If the block action also applies, the presence or absence of this
3965 mark decides whether an HTML "blocked" page, or a replacement image (as
3966 determined by the set-image-blocker action) will be sent to the client as a
3967 substitute for the blocked content.
3979 The below generic example section is actually part of default.action. It
3980 marks all URLs with well-known image file name extensions as images and
3981 should be left intact.
3983 Users will probably only want to use the handle-as-image action in
3984 conjunction with block, to block sources of banners, whose URLs don't
3985 reflect the file type, like in the second example section.
3987 Note that you cannot treat HTML pages as images in most cases. For
3988 instance, (in-line) ad frames require an HTML page to be sent, or they
3989 won't display properly. Forcing handle-as-image in this situation will not
3990 replace the ad frame with an image, but lead to error messages.
3992 Example usage (sections):
3994 # Generic image extensions:
3997 /.*\.(gif|jpg|jpeg|png|bmp|ico)$
3999 # These don't look like images, but they're banners and should be
4000 # blocked as images:
4002 {+block +handle-as-image}
4003 some.nasty-banner-server.com/junk.cgi\?output=trash
4005 # Banner source! Who cares if they also have non-image content?
4009 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4011 8.5.19. hide-accept-language
4015 Pretend to use different language settings.
4019 Deletes or replaces the "Accept-Language:" HTTP header in client requests.
4027 Keyword: "block", or any user defined value.
4031 Faking the browser's language settings can be useful to make a foreign
4032 User-Agent set with hide-user-agent more believable.
4034 However some sites with content in different languages check the
4035 "Accept-Language:" to decide which one to take by default. Sometimes it
4036 isn't possible to later switch to another language without changing the
4037 "Accept-Language:" header first.
4039 Therefore it's a good idea to either only change the "Accept-Language:"
4040 header to languages you understand, or to languages that aren't wide
4043 Before setting the "Accept-Language:" header to a rare language, you should
4044 consider that it helps to make your requests unique and thus easier to
4045 trace. If you don't plan to change this header frequently, you should stick
4046 to a common language.
4048 Example usage (section):
4050 # Pretend to use Canadian language settings.
4051 {+hide-accept-language{en-ca} \
4052 +hide-user-agent{Mozilla/5.0 (X11; U; OpenBSD i386; en-CA; rv:1.8.0.4) Gecko/20060628 Firefox/1.5.0.4} \
4057 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4059 8.5.20. hide-content-disposition
4063 Prevent download menus for content you prefer to view inside the browser.
4067 Deletes or replaces the "Content-Disposition:" HTTP header set by some
4076 Keyword: "block", or any user defined value.
4080 Some servers set the "Content-Disposition:" HTTP header for documents they
4081 assume you want to save locally before viewing them. The
4082 "Content-Disposition:" header contains the file name the browser is
4083 supposed to use by default.
4085 In most browsers that understand this header, it makes it impossible to
4086 just view the document, without downloading it first, even if it's just a
4087 simple text file or an image.
4089 Removing the "Content-Disposition:" header helps to prevent this annoyance,
4090 but some browsers additionally check the "Content-Type:" header, before
4091 they decide if they can display a document without saving it first. In
4092 these cases, you have to change this header as well, before the browser
4093 stops displaying download menus.
4095 It is also possible to change the server's file name suggestion to another
4096 one, but in most cases it isn't worth the time to set it up.
4098 This action will probably be removed in the future, use server-header
4103 # Disarm the download link in Sourceforge's patch tracker
4105 +content-type-overwrite{text/plain}\
4106 +hide-content-disposition{block} }
4107 .sourceforge.net/tracker/download\.php
4110 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4112 8.5.21. hide-if-modified-since
4116 Prevent yet another way to track the user's steps between sessions.
4120 Deletes the "If-Modified-Since:" HTTP client header or modifies its value.
4128 Keyword: "block", or a user defined value that specifies a range of hours.
4132 Removing this header is useful for filter testing, where you want to force
4133 a real reload instead of getting status code "304", which would cause the
4134 browser to use a cached copy of the page.
4136 Instead of removing the header, hide-if-modified-since can also add or
4137 subtract a random amount of time to/from the header's value. You specify a
4138 range of minutes where the random factor should be chosen from and Privoxy
4139 does the rest. A negative value means subtracting, a positive value adding.
4141 Randomizing the value of the "If-Modified-Since:" makes it less likely that
4142 the server can use the time as a cookie replacement, but you will run into
4143 caching problems if the random range is too high.
4145 It is a good idea to only use a small negative value and let
4146 overwrite-last-modified handle the greater changes.
4148 It is also recommended to use this action together with
4149 crunch-if-none-match, otherwise it's more or less pointless.
4151 Example usage (section):
4153 # Let the browser revalidate but make tracking based on the time less likely.
4154 {+hide-if-modified-since{-60} \
4155 +overwrite-last-modified{randomize} \
4156 +crunch-if-none-match}
4160 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4162 8.5.22. hide-forwarded-for-headers
4166 Improve privacy by not forwarding the source of the request in the HTTP
4171 Deletes any existing "X-Forwarded-for:" HTTP header from client requests.
4183 It is safe and recommended to leave this on.
4187 +hide-forwarded-for-headers
4190 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4192 8.5.23. hide-from-header
4196 Keep your (old and ill) browser from telling web servers your email address
4200 Deletes any existing "From:" HTTP header, or replaces it with the specified
4209 Keyword: "block", or any user defined value.
4213 The keyword "block" will completely remove the header (not to be confused
4214 with the block action).
4216 Alternately, you can specify any value you prefer to be sent to the web
4217 server. If you do, it is a matter of fairness not to use any address that
4218 is actually used by a real person.
4220 This action is rarely needed, as modern web browsers don't send "From:"
4225 +hide-from-header{block}
4230 +hide-from-header{spam-me-senseless@sittingduck.example.com}
4233 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4235 8.5.24. hide-referrer
4239 Conceal which link you followed to get to a particular site
4243 Deletes the "Referer:" (sic) HTTP header from the client request, or
4244 replaces it with a forged one.
4252 □ "conditional-block" to delete the header completely if the host has
4255 □ "conditional-forge" to forge the header if the host has changed.
4257 □ "block" to delete the header unconditionally.
4259 □ "forge" to pretend to be coming from the homepage of the server we are
4262 □ Any other string to set a user defined referrer.
4266 conditional-block is the only parameter, that isn't easily detected in the
4267 server's log file. If it blocks the referrer, the request will look like
4268 the visitor used a bookmark or typed in the address directly.
4270 Leaving the referrer unmodified for requests on the same host allows the
4271 server owner to see the visitor's "click path", but in most cases she could
4272 also get that information by comparing other parts of the log file: for
4273 example the User-Agent if it isn't a very common one, or the user's IP
4274 address if it doesn't change between different requests.
4276 Always blocking the referrer, or using a custom one, can lead to failures
4277 on servers that check the referrer before they answer any requests, in an
4278 attempt to prevent their content from being embedded or linked to
4281 Both conditional-block and forge will work with referrer checks, as long as
4282 content and valid referring page are on the same host. Most of the time
4285 hide-referer is an alternate spelling of hide-referrer and the two can be
4286 can be freely substituted with each other. ("referrer" is the correct
4287 English spelling, however the HTTP specification has a bug - it requires it
4288 to be spelled as "referer".)
4292 +hide-referrer{forge}
4297 +hide-referrer{http://www.yahoo.com/}
4300 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4302 8.5.25. hide-user-agent
4306 Try to conceal your type of browser and client operating system
4310 Replaces the value of the "User-Agent:" HTTP header in client requests with
4311 the specified value.
4319 Any user-defined string.
4323 ┌─────────────────────────────────────────────────────────────────┐
4325 ├─────────────────────────────────────────────────────────────────┤
4326 │This can lead to problems on web sites that depend on looking at │
4327 │this header in order to customize their content for different │
4328 │browsers (which, by the way, is NOT the right thing to do: good │
4329 │web sites work browser-independently). │
4330 └─────────────────────────────────────────────────────────────────┘
4332 Using this action in multi-user setups or wherever different types of
4333 browsers will access the same Privoxy is not recommended. In single-user,
4334 single-browser setups, you might use it to delete your OS version
4335 information from the headers, because it is an invitation to exploit known
4336 bugs for your OS. It is also occasionally useful to forge this in order to
4337 access sites that won't let you in otherwise (though there may be a good
4338 reason in some cases). Example of this: some MSN sites will not let Mozilla
4339 enter, yet forging to a Netscape 6.1 user-agent works just fine. (Must be
4340 just a silly MS goof, I'm sure :-).
4342 More information on known user-agent strings can be found at http://
4343 www.user-agents.org/ and http://en.wikipedia.org/wiki/User_agent.
4347 +hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}
4350 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4352 8.5.26. inspect-jpegs
4356 Try to protect against a MS buffer over-run in JPEG processing
4360 Protect against a known exploit
4372 See Microsoft Security Bulletin MS04-028. JPEG images are one of the most
4373 common image types found across the Internet. The exploit as described can
4374 allow execution of code on the target system, giving an attacker access to
4375 the system in question by merely planting an altered JPEG image, which
4376 would have no obvious indications of what lurks inside. This action tries
4377 to prevent this exploit if delivered through unencrypted HTTP.
4379 Note that the exploit mentioned is several years old and it's unlikely that
4380 your client is still vulnerable against it. This action may be removed in
4381 one of the next releases.
4388 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4394 Eliminate those annoying pop-up windows (deprecated)
4398 While loading the document, replace JavaScript code that opens pop-up
4399 windows with (syntactically neutral) dummy code on the fly.
4411 This action is basically a built-in, hardwired special-purpose filter
4412 action, but there are important differences: For kill-popups, the document
4413 need not be buffered, so it can be incrementally rendered while
4414 downloading. But kill-popups doesn't catch as many pop-ups as filter
4415 {all-popups} does and is not as smart as filter{unsolicited-popups} is.
4417 Think of it as a fast and efficient replacement for a filter that you can
4418 use if you don't want any filtering at all. Note that it doesn't make sense
4419 to combine it with any filter action, since as soon as one filter applies,
4420 the whole document needs to be buffered anyway, which destroys the
4421 advantage of the kill-popups action over its filter equivalent.
4423 Killing all pop-ups unconditionally is problematic. Many shops and banks
4424 rely on pop-ups to display forms, shopping carts etc, and the filter
4425 {unsolicited-popups} does a better job of catching only the unwanted ones.
4427 If the only kind of pop-ups that you want to kill are exit consoles (those
4428 really nasty windows that appear when you close an other one), you might
4429 want to use filter{js-annoyances} instead.
4431 This action is most appropriate for browsers that don't have any controls
4432 for unwanted pop-ups. Not recommended for general usage.
4434 This action doesn't work very reliable and may be removed in future
4442 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4444 8.5.28. limit-connect
4448 Prevent abuse of Privoxy as a TCP proxy relay or disable SSL for untrusted
4453 Specifies to which ports HTTP CONNECT requests are allowable.
4461 A comma-separated list of ports or port ranges (the latter using dashes,
4462 with the minimum defaulting to 0 and the maximum to 65K).
4466 By default, i.e. if no limit-connect action applies, Privoxy only allows
4467 HTTP CONNECT requests to port 443 (the standard, secure HTTPS port). Use
4468 limit-connect if more fine-grained control is desired for some or all
4471 The CONNECT methods exists in HTTP to allow access to secure websites
4472 ("https://" URLs) through proxies. It works very simply: the proxy connects
4473 to the server on the specified port, and then short-circuits its
4474 connections to the client and to the remote server. This means
4475 CONNECT-enabled proxies can be used as TCP relays very easily.
4477 Privoxy relays HTTPS traffic without seeing the decoded content. Websites
4478 can leverage this limitation to circumvent Privoxy's filters. By specifying
4479 an invalid port range you can disable HTTPS entirely. If you plan to
4480 disable SSL by default, consider enabling
4481 treat-forbidden-connects-like-blocks as well, to be able to quickly create
4486 +limit-connect{443} # This is the default and need not be specified.
4487 +limit-connect{80,443} # Ports 80 and 443 are OK.
4488 +limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
4489 +limit-connect{-} # All ports are OK
4490 +limit-connect{,} # No HTTPS/SSL traffic is allowed
4493 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4495 8.5.29. prevent-compression
4499 Ensure that servers send the content uncompressed, so it can be passed
4504 Removes the Accept-Encoding header which can be used to ask for compressed
4517 More and more websites send their content compressed by default, which is
4518 generally a good idea and saves bandwidth. But the filter, deanimate-gifs
4519 and kill-popups actions need access to the uncompressed data.
4521 When compiled with zlib support (available since Privoxy 3.0.7), content
4522 that should be filtered is decompressed on-the-fly and you don't have to
4523 worry about this action. If you are using an older Privoxy version, or one
4524 that hasn't been compiled with zlib support, this action can be used to
4525 convince the server to send the content uncompressed.
4527 Most text-based instances compress very well, the size is seldom decreased
4528 by less than 50%, for markup-heavy instances like news feeds saving more
4529 than 90% of the original size isn't unusual.
4531 Not using compression will therefore slow down the transfer, and you should
4532 only enable this action if you really need it. As of Privoxy 3.0.7 it's
4533 disabled in all predefined action settings.
4535 Note that some (rare) ill-configured sites don't handle requests for
4536 uncompressed documents correctly. Broken PHP applications tend to send an
4537 empty document body, some IIS versions only send the beginning of the
4538 content. If you enable prevent-compression per default, you might want to
4539 add exceptions for those sites. See the example for how to do that.
4541 Example usage (sections):
4543 # Selectively turn off compression, and enable a filter
4545 { +filter{tiny-textforms} +prevent-compression }
4546 # Match only these sites
4551 # Or instead, we could set a universal default:
4553 { +prevent-compression }
4556 # Then maybe make exceptions for broken sites:
4558 { -prevent-compression }
4562 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4564 8.5.30. overwrite-last-modified
4568 Prevent yet another way to track the user's steps between sessions.
4572 Deletes the "Last-Modified:" HTTP server header or modifies its value.
4580 One of the keywords: "block", "reset-to-request-time" and "randomize"
4584 Removing the "Last-Modified:" header is useful for filter testing, where
4585 you want to force a real reload instead of getting status code "304", which
4586 would cause the browser to reuse the old version of the page.
4588 The "randomize" option overwrites the value of the "Last-Modified:" header
4589 with a randomly chosen time between the original value and the current
4590 time. In theory the server could send each document with a different
4591 "Last-Modified:" header to track visits without using cookies. "Randomize"
4592 makes it impossible and the browser can still revalidate cached documents.
4594 "reset-to-request-time" overwrites the value of the "Last-Modified:" header
4595 with the current time. You could use this option together with
4596 hided-if-modified-since to further customize your random range.
4598 The preferred parameter here is "randomize". It is safe to use, as long as
4599 the time settings are more or less correct. If the server sets the
4600 "Last-Modified:" header to the time of the request, the random range
4601 becomes zero and the value stays the same. Therefore you should later
4602 randomize it a second time with hided-if-modified-since, just to be sure.
4604 It is also recommended to use this action together with
4605 crunch-if-none-match.
4609 # Let the browser revalidate without being tracked across sessions
4610 { +hide-if-modified-since{-60} \
4611 +overwrite-last-modified{randomize} \
4612 +crunch-if-none-match}
4616 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4622 Redirect requests to other sites.
4626 Convinces the browser that the requested document has been moved to another
4627 location and the browser should get it from there.
4635 An absolute URL or a single pcrs command.
4639 Requests to which this action applies are answered with a HTTP redirect to
4640 URLs of your choosing. The new URL is either provided as parameter, or
4641 derived by applying a single pcrs command to the original URL.
4643 This action will be ignored if you use it together with block. It can be
4644 combined with fast-redirects{check-decoded-url} to redirect to a decoded
4645 version of a rewritten URL.
4647 Use this action carefully, make sure not to create redirection loops and be
4648 aware that using your own redirects might make it possible to fingerprint
4653 # Replace example.com's style sheet with another one
4654 { +redirect{http://localhost/css-replacements/example.com.css} }
4655 example.com/stylesheet\.css
4657 # Create a short, easy to remember nickname for a favorite site
4658 # (relies on the browser accept and forward invalid URLs to Privoxy)
4659 { +redirect{http://www.privoxy.org/user-manual/actions-file.html} }
4662 # Always use the expanded view for Undeadly.org articles
4663 # (Note the $ at the end of the URL pattern to make sure
4664 # the request for the rewritten URL isn't redirected as well)
4665 {+redirect{s@$@&mode=expanded@}}
4666 undeadly.org/cgi\?action=article&sid=\d*$
4669 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4671 8.5.32. send-vanilla-wafer
4675 Feed log analysis scripts with useless data.
4679 Sends a cookie with each request stating that you do not accept any
4680 copyright on cookies sent to you, and asking the site operator not to track
4693 The vanilla wafer is a (relatively) unique header and could conceivably be
4696 This action is rarely used and not enabled in the default configuration.
4703 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4709 Send custom cookies or feed log analysis scripts with even more useless
4714 Sends a custom, user-defined cookie with each request.
4722 A string of the form "name=value".
4726 Being multi-valued, multiple instances of this action can apply to the same
4727 request, resulting in multiple cookies being sent.
4729 This action is rarely used and not enabled in the default configuration.
4731 Example usage (section):
4733 {+send-wafer{UsingPrivoxy=true}}
4734 my-internal-testing-server.void
4737 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4739 8.5.34. server-header-filter
4743 Rewrite or remove single server headers.
4747 All server headers to which this action applies are filtered on-the-fly
4748 through the specified regular expression based substitutions.
4756 The name of a server-header filter, as defined in one of the filter files.
4760 Server-header filters are applied to each header on its own, not to all at
4761 once. This makes it easier to diagnose problems, but on the downside you
4762 can't write filters that only change header x if header y's value is z. You
4763 can do that by using tags though.
4765 Server-header filters are executed after the other header actions have
4766 finished and use their output as input.
4768 Please refer to the filter file chapter to learn which server-header
4769 filters are available by default, and how to create your own.
4771 Example usage (section):
4773 {+server-header-filter{html-to-xml}}
4774 example.org/xml-instance-that-is-delivered-as-html
4776 {+server-header-filter{xml-to-html}}
4777 example.org/instance-that-is-delivered-as-xml-but-is-not
4781 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4783 8.5.35. server-header-tagger
4787 Enable or disable filters based on the Content-Type header.
4791 Server headers to which this action applies are filtered on-the-fly through
4792 the specified regular expression based substitutions, the result is used as
4801 The name of a server-header tagger, as defined in one of the filter files.
4805 Server-header taggers are applied to each header on its own, and as the
4806 header isn't modified, each tagger "sees" the original.
4808 Server-header taggers are executed before all other header actions that
4809 modify server headers. Their tags can be used to control all of the other
4810 server-header actions, the content filters and the crunch actions (redirect
4813 Obviously crunching based on tags created by server-header taggers doesn't
4814 prevent the request from showing up in the server's log file.
4816 Example usage (section):
4818 # Tag every request with the content type declared by the server
4819 {+server-header-tagger{content-type}}
4824 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4826 8.5.36. session-cookies-only
4830 Allow only temporary "session" cookies (for the current browser session
4835 Deletes the "expires" field from "Set-Cookie:" server headers. Most
4836 browsers will not store such cookies permanently and forget them in between
4849 This is less strict than crunch-incoming-cookies / crunch-outgoing-cookies
4850 and allows you to browse websites that insist or rely on setting cookies,
4851 without compromising your privacy too badly.
4853 Most browsers will not permanently store cookies that have been processed
4854 by session-cookies-only and will forget about them between sessions. This
4855 makes profiling cookies useless, but won't break sites which require
4856 cookies so that you can log in for transactions. This is generally turned
4857 on for all sites, and is the recommended setting.
4859 It makes no sense at all to use session-cookies-only together with
4860 crunch-incoming-cookies or crunch-outgoing-cookies. If you do, cookies will
4863 Note that it is up to the browser how it handles such cookies without an
4864 "expires" field. If you use an exotic browser, you might want to try it out
4867 This setting also has no effect on cookies that may have been stored
4868 previously by the browser before starting Privoxy. These would have to be
4871 Privoxy also uses the content-cookies filter to block some types of
4872 cookies. Content cookies are not effected by session-cookies-only.
4876 +session-cookies-only
4879 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4881 8.5.37. set-image-blocker
4885 Choose the replacement for blocked images
4889 This action alone doesn't do anything noticeable. If both block and
4890 handle-as-image also apply, i.e. if the request is to be blocked as an
4891 image, then the parameter of this action decides what will be sent as a
4900 □ "pattern" to send a built-in checkerboard pattern image. The image is
4901 visually decent, scales very well, and makes it obvious where banners
4904 □ "blank" to send a built-in transparent image. This makes banners
4905 disappear completely, but makes it hard to detect where Privoxy has
4906 blocked images on a given page and complicates troubleshooting if
4907 Privoxy has blocked innocent images, like navigation icons.
4909 □ "target-url" to send a redirect to target-url. You can redirect to any
4910 image anywhere, even in your local filesystem via "file:///" URL. (But
4911 note that not all browsers support redirecting to a local file system).
4913 A good application of redirects is to use special Privoxy-built-in
4914 URLs, which send the built-in images, as target-url. This has the same
4915 visual effect as specifying "blank" or "pattern" in the first place,
4916 but enables your browser to cache the replacement image, instead of
4917 requesting it over and over again.
4921 The URLs for the built-in images are "http://config.privoxy.org/
4922 send-banner?type=type", where type is either "blank" or "pattern".
4924 There is a third (advanced) type, called "auto". It is NOT to be used in
4925 set-image-blocker, but meant for use from filters. Auto will select the
4926 type of image that would have applied to the referring page, had it been an
4933 +set-image-blocker{pattern}
4936 Redirect to the BSD daemon:
4938 +set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}
4941 Redirect to the built-in pattern for better caching:
4943 +set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}
4946 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4948 8.5.38. treat-forbidden-connects-like-blocks
4952 Block forbidden connects with an easy to find error message.
4956 If this action is enabled, Privoxy no longer makes a difference between
4957 forbidden connects and ordinary blocks.
4969 By default Privoxy answers forbidden "Connect" requests with a short error
4970 message inside the headers. If the browser doesn't display headers (most
4971 don't), you just see an empty page.
4973 With this action enabled, Privoxy displays the message that is used for
4974 ordinary blocks instead. If you decide to make an exception for the page in
4975 question, you can do so by following the "See why" link.
4977 For "Connect" requests the clients tell Privoxy which host they are
4978 interested in, but not which document they plan to get later. As a result,
4979 the "Go there anyway" wouldn't work and is therefore suppressed.
4983 +treat-forbidden-connects-like-blocks
4986 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4990 Note that many of these actions have the potential to cause a page to
4991 misbehave, possibly even not to display at all. There are many ways a site
4992 designer may choose to design his site, and what HTTP header content, and other
4993 criteria, he may depend on. There is no way to have hard and fast rules for all
4994 sites. See the Appendix for a brief example on troubleshooting actions.
4996 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
5000 Custom "actions", known to Privoxy as "aliases", can be defined by combining
5001 other actions. These can in turn be invoked just like the built-in actions.
5002 Currently, an alias name can contain any character except space, tab, "=", "{"
5003 and "}", but we strongly recommend that you only use "a" to "z", "0" to "9",
5004 "+", and "-". Alias names are not case sensitive, and are not required to start
5005 with a "+" or "-" sign, since they are merely textually expanded.
5007 Aliases can be used throughout the actions file, but they must be defined in a
5008 special section at the top of the file! And there can only be one such section
5009 per actions file. Each actions file may have its own alias section, and the
5010 aliases defined in it are only visible within that file.
5012 There are two main reasons to use aliases: One is to save typing for frequently
5013 used combinations of actions, the other one is a gain in flexibility: If you
5014 decide once how you want to handle shops by defining an alias called "shop",
5015 you can later change your policy on shops in one place, and your changes will
5016 take effect everywhere in the actions file where the "shop" alias is used.
5017 Calling aliases by their purpose also makes your actions files more readable.
5019 Currently, there is one big drawback to using aliases, though: Privoxy's
5020 built-in web-based action file editor honors aliases when reading the actions
5021 files, but it expands them before writing. So the effects of your aliases are
5022 of course preserved, but the aliases themselves are lost when you edit sections
5023 that use aliases with it.
5025 Now let's define some aliases...
5027 # Useful custom aliases we can use later.
5029 # Note the (required!) section header line and that this section
5030 # must be at the top of the actions file!
5034 # These aliases just save typing later:
5035 # (Note that some already use other aliases!)
5037 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
5038 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
5039 +block-as-image = +block +handle-as-image
5040 allow-all-cookies = -crunch-all-cookies -session-cookies-only -filter{content-cookies}
5042 # These aliases define combinations of actions
5043 # that are useful for certain types of sites:
5045 fragile = -block -filter -crunch-all-cookies -fast-redirects -hide-referrer -kill-popups -prevent-compression
5047 shop = -crunch-all-cookies -filter{all-popups} -kill-popups
5049 # Short names for other aliases, for really lazy people ;-)
5051 c0 = +crunch-all-cookies
5052 c1 = -crunch-all-cookies
5055 ...and put them to use. These sections would appear in the lower part of an
5056 actions file and define exceptions to the default actions (as specified further
5057 up for the "/" pattern):
5059 # These sites are either very complex or very keen on
5060 # user data and require minimal interference to work:
5063 .office.microsoft.com
5064 .windowsupdate.microsoft.com
5065 # Gmail is really mail.google.com, not gmail.com
5069 # Allow cookies (for setting and retrieving your customer data)
5073 .worldpay.com # for quietpc.com
5076 # These shops require pop-ups:
5078 {-kill-popups -filter{all-popups} -filter{unsolicited-popups}}
5083 Aliases like "shop" and "fragile" are typically used for "problem" sites that
5084 require more than one action to be disabled in order to function properly.
5086 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
5088 8.7. Actions Files Tutorial
5090 The above chapters have shown which actions files there are and how they are
5091 organized, how actions are specified and applied to URLs, how patterns work,
5092 and how to define and use aliases. Now, let's look at an example default.action
5093 and user.action file and see how all these pieces come together:
5095 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
5097 8.7.1. default.action
5099 Every config file should start with a short comment stating its purpose:
5101 # Sample default.action file <ijbswa-developers@lists.sourceforge.net>
5104 Then, since this is the default.action file, the first section is a special
5105 section for internal use that you needn't change or worry about:
5107 ##########################################################################
5108 # Settings -- Don't change! For internal Privoxy use ONLY.
5109 ##########################################################################
5112 for-privoxy-version=3.0
5115 After that comes the (optional) alias section. We'll use the example section
5116 from the above chapter on aliases, that also explains why and how aliases are
5119 ##########################################################################
5121 ##########################################################################
5124 # These aliases just save typing later:
5125 # (Note that some already use other aliases!)
5127 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
5128 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
5129 +block-as-image = +block +handle-as-image
5130 mercy-for-cookies = -crunch-all-cookies -session-cookies-only -filter{content-cookies}
5132 # These aliases define combinations of actions
5133 # that are useful for certain types of sites:
5135 fragile = -block -filter -crunch-all-cookies -fast-redirects -hide-referrer -kill-popups
5136 shop = -crunch-all-cookies -filter{all-popups} -kill-popups
5139 Now come the regular sections, i.e. sets of actions, accompanied by URL
5140 patterns to which they apply. Remember all actions are disabled when matching
5141 starts, so we have to explicitly enable the ones we want.
5143 The first regular section is probably the most important. It has only one
5144 pattern, "/", but this pattern matches all URLs. Therefore, the set of actions
5145 used in this "default" section will be applied to all requests as a start. It
5146 can be partly or wholly overridden by later matches further down this file, or
5147 in user.action, but it will still be largely responsible for your overall
5148 browsing experience.
5150 Again, at the start of matching, all actions are disabled, so there is no need
5151 to disable any actions here. (Remember: a "+" preceding the action name enables
5152 the action, a "-" disables!). Also note how this long line has been made more
5153 readable by splitting it into multiple lines with line continuation.
5155 ##########################################################################
5156 # "Defaults" section:
5157 ##########################################################################
5160 +filter{html-annoyances} \
5161 +filter{refresh-tags} \
5163 +filter{ie-exploits} \
5164 +hide-forwarded-for-headers \
5165 +hide-from-header{block} \
5166 +hide-referrer{forge} \
5167 +prevent-compression \
5168 +session-cookies-only \
5169 +set-image-blocker{pattern} \
5171 / # forward slash will match *all* potential URL patterns.
5174 The default behavior is now set.
5176 The first of our specialized sections is concerned with "fragile" sites, i.e.
5177 sites that require minimum interference, because they are either very complex
5178 or very keen on tracking you (and have mechanisms in place that make them
5179 unusable for people who avoid being tracked). We will simply use our
5180 pre-defined fragile alias instead of stating the list of actions explicitly:
5182 ##########################################################################
5183 # Exceptions for sites that'll break under the default action set:
5184 ##########################################################################
5186 # "Fragile" Use a minimum set of actions for these sites (see alias above):
5189 .office.microsoft.com # surprise, surprise!
5190 .windowsupdate.microsoft.com
5194 Shopping sites are not as fragile, but they typically require cookies to log
5195 in, and pop-up windows for shopping carts or item details. Again, we'll use a
5202 .worldpay.com # for quietpc.com
5207 The fast-redirects action, which we enabled per default above, breaks some
5208 sites. So disable it for popular sites where we know it misbehaves:
5214 .altavista.com/.*(like|url|link):http
5215 .altavista.com/trans.*urltext=http
5219 It is important that Privoxy knows which URLs belong to images, so that if they
5220 are to be blocked, a substitute image can be sent, rather than an HTML page.
5221 Contacting the remote site to find out is not an option, since it would destroy
5222 the loading time advantage of banner blocking, and it would feed the
5223 advertisers (in terms of money and information). We can mark any URL as an
5224 image with the handle-as-image action, and marking all URLs that end in a known
5225 image file extension is a good start:
5227 ##########################################################################
5229 ##########################################################################
5231 # Define which file types will be treated as images, in case they get
5232 # blocked further down this file:
5234 { +handle-as-image }
5235 /.*\.(gif|jpe?g|png|bmp|ico)$
5238 And then there are known banner sources. They often use scripts to generate the
5239 banners, so it won't be visible from the URL that the request is for an image.
5240 Hence we block them and mark them as images in one go, with the help of our
5241 +block-as-image alias defined above. (We could of course just as well use +
5242 block +handle-as-image here.) Remember that the type of the replacement image
5243 is chosen by the set-image-blocker action. Since all URLs have matched the
5244 default section with its +set-image-blocker{pattern} action before, it still
5245 applies and needn't be repeated:
5247 # Known ad generators:
5252 .ad.*.doubleclick.net
5253 .a.yimg.com/(?:(?!/i/).)*$
5254 .a[0-9].yimg.com/(?:(?!/i/).)*$
5259 One of the most important jobs of Privoxy is to block banners. Many of these
5260 can be "blocked" by the filter{banners-by-size} action, which we enabled above,
5261 and which deletes the references to banner images from the pages while they are
5262 loaded, so the browser doesn't request them anymore, and hence they don't need
5263 to be blocked here. But this naturally doesn't catch all banners, and some
5264 people choose not to use filters, so we need a comprehensive list of patterns
5265 for banner URLs here, and apply the block action to them.
5267 First comes many generic patterns, which do most of the work, by matching
5268 typical domain and path name components of banners. Then comes a list of
5269 individual patterns for specific sites, which is omitted here to keep the
5272 ##########################################################################
5273 # Block these fine banners:
5274 ##########################################################################
5283 /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
5284 /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
5286 # Site-specific patterns (abbreviated):
5291 It's quite remarkable how many advertisers actually call their banner servers
5292 ads.company.com, or call the directory in which the banners are stored simply
5293 "banners". So the above generic patterns are surprisingly effective.
5295 But being very generic, they necessarily also catch URLs that we don't want to
5296 block. The pattern .*ads. e.g. catches "nasty-ads.nasty-corp.com" as intended,
5297 but also "downloads.sourcefroge.net" or "adsl.some-provider.net." So here come
5298 some well-known exceptions to the +block section above.
5300 Note that these are exceptions to exceptions from the default! Consider the URL
5301 "downloads.sourcefroge.net": Initially, all actions are deactivated, so it
5302 wouldn't get blocked. Then comes the defaults section, which matches the URL,
5303 but just deactivates the block action once again. Then it matches .*ads., an
5304 exception to the general non-blocking policy, and suddenly +block applies. And
5305 now, it'll match .*loads., where -block applies, so (unless it matches again
5306 further down) it ends up with no block action applying.
5308 ##########################################################################
5309 # Save some innocent victims of the above generic block patterns:
5310 ##########################################################################
5315 adv[io]*. # (for advogato.org and advice.*)
5316 adsl. # (has nothing to do with ads)
5317 adobe. # (has nothing to do with ads either)
5318 ad[ud]*. # (adult.* and add.*)
5319 .edu # (universities don't host banners (yet!))
5320 .*loads. # (downloads, uploads etc)
5328 www.globalintersec.com/adv # (adv = advanced)
5329 www.ugu.com/sui/ugu/adv
5332 Filtering source code can have nasty side effects, so make an exception for our
5333 friends at sourceforge.net, and all paths with "cvs" in them. Note that -filter
5334 disables all filters in one fell swoop!
5336 # Don't filter code!
5346 The actual default.action is of course much more comprehensive, but we hope
5347 this example made clear how it works.
5349 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
5353 So far we are painting with a broad brush by setting general policies, which
5354 would be a reasonable starting point for many people. Now, you might want to be
5355 more specific and have customized rules that are more suitable to your personal
5356 habits and preferences. These would be for narrowly defined situations like
5357 your ISP or your bank, and should be placed in user.action, which is parsed
5358 after all other actions files and hence has the last word, over-riding any
5359 previously defined actions. user.action is also a safe place for your personal
5360 settings, since default.action is actively maintained by the Privoxy developers
5361 and you'll probably want to install updated versions from time to time.
5363 So let's look at a few examples of things that one might typically do in
5366 # My user.action file. <fred@example.com>
5369 As aliases are local to the actions file that they are defined in, you can't
5370 use the ones from default.action, unless you repeat them here:
5372 # Aliases are local to the file they are defined in.
5373 # (Re-)define aliases for this file:
5377 # These aliases just save typing later, and the alias names should
5378 # be self explanatory.
5380 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
5381 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
5382 allow-all-cookies = -crunch-all-cookies -session-cookies-only
5383 allow-popups = -filter{all-popups} -kill-popups
5384 +block-as-image = +block +handle-as-image
5385 -block-as-image = -block
5387 # These aliases define combinations of actions that are useful for
5388 # certain types of sites:
5390 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referrer -kill-popups
5391 shop = -crunch-all-cookies allow-popups
5393 # Allow ads for selected useful free sites:
5395 allow-ads = -block -filter{banners-by-size} -filter{banners-by-link}
5397 # Alias for specific file types that are text, but might have conflicting
5398 # MIME types. We want the browser to force these to be text documents.
5399 handle-as-text = -filter +-content-type-overwrite{text/plain} +-force-text-mode -hide-content-disposition
5404 Say you have accounts on some sites that you visit regularly, and you don't
5405 want to have to log in manually each time. So you'd like to allow persistent
5406 cookies for these sites. The allow-all-cookies alias defined above does exactly
5407 that, i.e. it disables crunching of cookies in any direction, and the
5408 processing of cookies to make them only temporary.
5410 { allow-all-cookies }
5417 Your bank is allergic to some filter, but you don't know which, so you disable
5421 .your-home-banking-site.com
5424 Some file types you may not want to filter for various reasons:
5426 # Technical documentation is likely to contain strings that might
5427 # erroneously get altered by the JavaScript-oriented filters:
5432 # And this stupid host sends streaming video with a wrong MIME type,
5433 # so that Privoxy thinks it is getting HTML and starts filtering:
5435 stupid-server.example.com/
5438 Example of a simple block action. Say you've seen an ad on your favourite page
5439 on example.com that you want to get rid of. You have right-clicked the image,
5440 selected "copy image location" and pasted the URL below while removing the
5441 leading http://, into a { +block } section. Note that { +handle-as-image } need
5442 not be specified, since all URLs ending in .gif will be tagged as images by the
5443 general rules as set in default.action anyway:
5446 www.example.com/nasty-ads/sponsor\.gif
5447 another.example.net/more/junk/here/
5450 The URLs of dynamically generated banners, especially from large banner farms,
5451 often don't use the well-known image file name extensions, which makes it
5452 impossible for Privoxy to guess the file type just by looking at the URL. You
5453 can use the +block-as-image alias defined above for these cases. Note that
5454 objects which match this rule but then turn out NOT to be an image are
5455 typically rendered as a "broken image" icon by the browser. Use cautiously.
5464 Now you noticed that the default configuration breaks Forbes Magazine, but you
5465 were too lazy to find out which action is the culprit, and you were again too
5466 lazy to give feedback, so you just used the fragile alias on the site, and --
5467 whoa! -- it worked. The fragile aliases disables those actions that are most
5468 likely to break a site. Also, good for testing purposes to see if it is Privoxy
5469 that is causing the problem or not. We later find other regular sites that
5470 misbehave, and add those to our personalized list of troublemakers:
5478 You like the "fun" text replacements in default.filter, but it is disabled in
5479 the distributed actions file. So you'd like to turn it on in your private,
5480 update-safe config, once and for all:
5486 Note that the above is not really a good idea: There are exceptions to the
5487 filters in default.action for things that really shouldn't be filtered, like
5488 code on CVS->Web interfaces. Since user.action has the last word, these
5489 exceptions won't be valid for the "fun" filtering specified here.
5491 You might also worry about how your favourite free websites are funded, and
5492 find that they rely on displaying banner advertisements to survive. So you
5493 might want to specifically allow banners for those sites that you feel provide
5502 Note that allow-ads has been aliased to -block, -filter{banners-by-size}, and -
5503 filter{banners-by-link} above.
5505 Invoke another alias here to force an over-ride of the MIME type application/
5506 x-sh which typically would open a download type dialog. In my case, I want to
5507 look at the shell script, and then I can save it should I choose to.
5513 user.action is generally the best place to define exceptions and additions to
5514 the default policies of default.action. Some actions are safe to have their
5515 default policies set here though. So let's set a default policy to have a
5516 "blank" image as opposed to the checkerboard pattern for ALL sites. "/" of
5517 course matches all URL paths and patterns:
5519 { +set-image-blocker{blank} }
5523 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
5527 On-the-fly text substitutions need to be defined in a "filter file". Once
5528 defined, they can then be invoked as an "action".
5530 Privoxy supports three different filter actions: filter to rewrite the content
5531 that is send to the client, client-header-filter to rewrite headers that are
5532 send by the client, and server-header-filter to rewrite headers that are send
5535 Privoxy also supports two tagger actions: client-header-tagger and
5536 server-header-tagger. Taggers and filters use the same syntax in the filter
5537 files, the difference is that taggers don't modify the text they are filtering,
5538 but use a rewritten version of the filtered text as tag. The tags can then be
5539 used to change the applying actions through sections with tag-patterns.
5541 Multiple filter files can be defined through the filterfile config directive.
5542 The filters as supplied by the developers are located in default.filter. It is
5543 recommended that any locally defined or modified filters go in a separately
5544 defined file such as user.filter.
5546 Common tasks for content filters are to eliminate common annoyances in HTML and
5547 JavaScript, such as pop-up windows, exit consoles, crippled windows without
5548 navigation tools, the infamous <BLINK> tag etc, to suppress images with certain
5549 width and height attributes (standard banner sizes or web-bugs), or just to
5552 Enabled content filters are applied to any content whose "Content Type" header
5553 is recognised as a sign of text-based content, with the exception of text/
5554 plain. Use the force-text-mode action to also filter other content.
5556 Substitutions are made at the source level, so if you want to "roll your own"
5557 filters, you should first be familiar with HTML syntax, and, of course, regular
5560 Just like the actions files, the filter file is organized in sections, which
5561 are called filters here. Each filter consists of a heading line, that starts
5562 with one of the keywords FILTER:, CLIENT-HEADER-FILTER: or
5563 SERVER-HEADER-FILTER: followed by the filter's name, and a short (one line)
5564 description of what it does. Below that line come the jobs, i.e. lines that
5565 define the actual text substitutions. By convention, the name of a filter
5566 should describe what the filter eliminates. The comment is used in the
5567 web-based user interface.
5569 Once a filter called name has been defined in the filter file, it can be
5570 invoked by using an action of the form +filter{name} in any actions file.
5572 Filter definitions start with a header line that contains the filter type, the
5573 filter name and the filter description. A content filter header line for a
5574 filter called "foo" could look like this:
5576 FILTER: foo Replace all "foo" with "bar"
5579 Below that line, and up to the next header line, come the jobs that define what
5580 text replacements the filter executes. They are specified in a syntax that
5581 imitates Perl's s/// operator. If you are familiar with Perl, you will find
5582 this to be quite intuitive, and may want to look at the PCRS documentation for
5583 the subtle differences to Perl behaviour. Most notably, the non-standard option
5584 letter U is supported, which turns the default to ungreedy matching.
5586 If you are new to "Regular Expressions", you might want to take a look at the
5587 Appendix on regular expressions, and see the Perl manual for the s///
5588 operator's syntax and Perl-style regular expressions in general. The below
5589 examples might also help to get you started.
5591 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
5593 9.1. Filter File Tutorial
5595 Now, let's complete our "foo" content filter. We have already defined the
5596 heading, but the jobs are still missing. Since all it does is to replace "foo"
5597 with "bar", there is only one (trivial) job needed:
5602 But wait! Didn't the comment say that all occurrences of "foo" should be
5603 replaced? Our current job will only take care of the first "foo" on each page.
5604 For global substitution, we'll need to add the g option:
5609 Our complete filter now looks like this:
5611 FILTER: foo Replace all "foo" with "bar"
5615 Let's look at some real filters for more interesting examples. Here you see a
5616 filter that protects against some common annoyances that arise from JavaScript
5617 abuse. Let's look at its jobs one after the other:
5619 FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse
5621 # Get rid of JavaScript referrer tracking. Test page: http://www.randomoddness.com/untitled.htm
5623 s|(<script.*)document\.referrer(.*</script>)|$1"Not Your Business!"$2|Usg
5626 Following the header line and a comment, you see the job. Note that it uses |
5627 as the delimiter instead of /, because the pattern contains a forward slash,
5628 which would otherwise have to be escaped by a backslash (\).
5630 Now, let's examine the pattern: it starts with the text <script.* enclosed in
5631 parentheses. Since the dot matches any character, and * means: "Match an
5632 arbitrary number of the element left of myself", this matches "<script",
5633 followed by any text, i.e. it matches the whole page, from the start of the
5636 That's more than we want, but the pattern continues: document\.referrer matches
5637 only the exact string "document.referrer". The dot needed to be escaped, i.e.
5638 preceded by a backslash, to take away its special meaning as a joker, and make
5639 it just a regular dot. So far, the meaning is: Match from the start of the
5640 first <script> tag in a the page, up to, and including, the text
5641 "document.referrer", if both are present in the page (and appear in that
5644 But there's still more pattern to go. The next element, again enclosed in
5645 parentheses, is .*</script>. You already know what .* means, so the whole
5646 pattern translates to: Match from the start of the first <script> tag in a page
5647 to the end of the last <script> tag, provided that the text "document.referrer"
5648 appears somewhere in between.
5650 This is still not the whole story, since we have ignored the options and the
5651 parentheses: The portions of the page matched by sub-patterns that are enclosed
5652 in parentheses, will be remembered and be available through the variables $1,
5653 $2, ... in the substitute. The U option switches to ungreedy matching, which
5654 means that the first .* in the pattern will only "eat up" all text in between "
5655 <script" and the first occurrence of "document.referrer", and that the second
5656 .* will only span the text up to the first "</script>" tag. Furthermore, the s
5657 option says that the match may span multiple lines in the page, and the g
5658 option again means that the substitution is global.
5660 So, to summarize, the pattern means: Match all scripts that contain the text
5661 "document.referrer". Remember the parts of the script from (and including) the
5662 start tag up to (and excluding) the string "document.referrer" as $1, and the
5663 part following that string, up to and including the closing tag, as $2.
5665 Now the pattern is deciphered, but wasn't this about substituting things? So
5666 lets look at the substitute: $1"Not Your Business!"$2 is easy to read: The text
5667 remembered as $1, followed by "Not Your Business!" (including the quotation
5668 marks!), followed by the text remembered as $2. This produces an exact copy of
5669 the original string, with the middle part (the "document.referrer") replaced by
5670 "Not Your Business!".
5672 The whole job now reads: Replace "document.referrer" by "Not Your Business!"
5673 wherever it appears inside a <script> tag. Note that this job won't break
5674 JavaScript syntax, since both the original and the replacement are
5675 syntactically valid string objects. The script just won't have access to the
5676 referrer information anymore.
5678 We'll show you two other jobs from the JavaScript taming department, but this
5679 time only point out the constructs of special interest:
5681 # The status bar is for displaying link targets, not pointless blahblah
5683 s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig
5686 \s stands for whitespace characters (space, tab, newline, carriage return, form
5687 feed), so that \s* means: "zero or more whitespace". The ? in .*? makes this
5688 matching of arbitrary text ungreedy. (Note that the U option is not set). The
5689 ['"] construct means: "a single or a double quote". Finally, \1 is a
5690 back-reference to the first parenthesis just like $1 above, with the difference
5691 that in the pattern, a backslash indicates a back-reference, whereas in the
5692 substitute, it's the dollar.
5694 So what does this job do? It replaces assignments of single- or double-quoted
5695 strings to the "window.status" object with a dummy assignment (using a variable
5696 name that is hopefully odd enough not to conflict with real variables in
5697 scripts). Thus, it catches many cases where e.g. pointless descriptions are
5698 displayed in the status bar instead of the link target when you move your mouse
5701 # Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html
5703 s/(<body [^>]*)onunload(.*>)/$1never$2/iU
5706 Including the OnUnload event binding in the HTML DOM was a CRIME. When I close
5707 a browser window, I want it to close and die. Basta. This job replaces the
5708 "onunload" attribute in "<body>" tags with the dummy word never. Note that the
5709 i option makes the pattern matching case-insensitive. Also note that ungreedy
5710 matching alone doesn't always guarantee a minimal match: In the first
5711 parenthesis, we had to use [^>]* instead of .* to prevent the match from
5712 exceeding the <body> tag if it doesn't contain "OnUnload", but the page's
5715 The last example is from the fun department:
5717 FILTER: fun Fun text replacements
5719 # Spice the daily news:
5721 s/microsoft(?!\.com)/MicroSuck/ig
5724 Note the (?!\.com) part (a so-called negative lookahead) in the job's pattern,
5725 which means: Don't match, if the string ".com" appears directly following
5726 "microsoft" in the page. This prevents links to microsoft.com from being
5727 trashed, while still replacing the word everywhere else.
5729 # Buzzword Bingo (example for extended regex syntax)
5731 s* industry[ -]leading \
5733 | customer[ -]focused \
5734 | market[ -]driven \
5735 | award[ -]winning # Comments are OK, too! \
5736 | high[ -]performance \
5737 | solutions[ -]based \
5741 *<font color="red"><b>BINGO!</b></font> \
5745 The x option in this job turns on extended syntax, and allows for e.g. the
5746 liberal use of (non-interpreted!) whitespace for nicer formatting.
5750 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
5752 9.2. The Pre-defined Filters
5754 The distribution default.filter file contains a selection of pre-defined
5755 filters for your convenience:
5759 The purpose of this filter is to get rid of particularly annoying
5760 JavaScript abuse. To that end, it
5762 □ replaces JavaScript references to the browser's referrer information
5763 with the string "Not Your Business!". This compliments the
5764 hide-referrer action on the content level.
5766 □ removes the bindings to the DOM's unload event which we feel has no
5767 right to exist and is responsible for most "exit consoles", i.e. nasty
5768 windows that pop up when you close another one.
5770 □ removes code that causes new windows to be opened with undesired
5771 properties, such as being full-screen, non-resizeable, without
5772 location, status or menu bar etc.
5774 Use with caution. This is an aggressive filter, and can break sites that
5775 rely heavily on JavaScript.
5779 This is a very radical measure. It removes virtually all JavaScript event
5780 bindings, which means that scripts can not react to user actions such as
5781 mouse movements or clicks, window resizing etc, anymore. Use with caution!
5783 We strongly discourage using this filter as a default since it breaks many
5784 legitimate scripts. It is meant for use only on extra-nasty sites (should
5785 you really need to go there).
5789 This filter will undo many common instances of HTML based abuse.
5791 The BLINK and MARQUEE tags are neutralized (yeah baby!), and browser
5792 windows will be created as resizeable (as of course they should be!), and
5793 will have location, scroll and menu bars -- even if specified otherwise.
5797 Most cookies are set in the HTTP dialog, where they can be intercepted by
5798 the crunch-incoming-cookies and crunch-outgoing-cookies actions. But web
5799 sites increasingly make use of HTML meta tags and JavaScript to sneak
5800 cookies to the browser on the content level.
5802 This filter disables most HTML and JavaScript code that reads or sets
5803 cookies. It cannot detect all clever uses of these types of code, so it
5804 should not be relied on as an absolute fix. Use it wherever you would also
5805 use the cookie crunch actions.
5809 Disable any refresh tags if the interval is greater than nine seconds (so
5810 that redirections done via refresh tags are not destroyed). This is useful
5811 for dial-on-demand setups, or for those who find this HTML feature
5816 This filter attempts to prevent only "unsolicited" pop-up windows from
5817 opening, yet still allow pop-up windows that the user has explicitly chosen
5818 to open. It was added in version 3.0.1, as an improvement over earlier such
5821 Technical note: The filter works by redefining the window.open JavaScript
5822 function to a dummy function, PrivoxyWindowOpen(), during the loading and
5823 rendering phase of each HTML page access, and restoring the function
5826 This is recommended only for browsers that cannot perform this function
5827 reliably themselves. And be aware that some sites require such windows in
5828 order to function normally. Use with caution.
5832 Attempt to prevent all pop-up windows from opening. Note this should be
5833 used with even more discretion than the above, since it is more likely to
5834 break some sites that require pop-ups for normal usage. Use with caution.
5838 This is a helper filter that has no value if used alone. It makes the
5839 banners-by-size and banners-by-link (see below) filters more effective and
5840 should be enabled together with them.
5844 This filter removes image tags purely based on what size they are.
5845 Fortunately for us, many ads and banner images tend to conform to certain
5846 standardized sizes, which makes this filter quite effective for ad
5849 Occasionally this filter will cause false positives on images that are not
5850 ads, but just happen to be of one of the standard banner sizes.
5852 Recommended only for those who require extreme ad blocking. The default
5853 block rules should catch 95+% of all ads without this filter enabled.
5857 This is an experimental filter that attempts to kill any banners if their
5858 URLs seem to point to known or suspected click trackers. It is currently
5859 not of much value and is not recommended for use by default.
5863 Webbugs are small, invisible images (technically 1X1 GIF images), that are
5864 used to track users across websites, and collect information on them. As an
5865 HTML page is loaded by the browser, an embedded image tag causes the
5866 browser to contact a third-party site, disclosing the tracking information
5867 through the requested URL and/or cookies for that third-party domain,
5868 without the user ever becoming aware of the interaction with the
5869 third-party site. HTML-ized spam also uses a similar technique to verify
5872 This filter removes the HTML code that loads such "webbugs".
5876 A rather special-purpose filter that can be used to enlarge textareas
5877 (those multi-line text boxes in web forms) and turn off hard word wrap in
5878 them. It was written for the sourceforge.net tracker system where such
5879 boxes are a nuisance, but it can be handy on other sites, too.
5881 It is not recommended to use this filter as a default.
5885 Many consider windows that move, or resize themselves to be abusive. This
5886 filter neutralizes the related JavaScript code. Note that some sites might
5887 not display or behave as intended when using this filter. Use with caution.
5891 Some web designers seem to assume that everyone in the world will view
5892 their web sites using the same browser brand and version, screen resolution
5893 etc, because only that assumption could explain why they'd use static frame
5894 sizes, yet prevent their frames from being resized by the user, should they
5895 be too small to show their whole content.
5897 This filter removes the related HTML code. It should only be applied to
5898 sites which need it.
5902 Many Microsoft products that generate HTML use non-standard extensions
5903 (read: violations) of the ISO 8859-1 aka Latin-1 character set. This can
5904 cause those HTML documents to display with errors on standard-compliant
5907 This filter translates the MS-only characters into Latin-1 equivalents. It
5908 is not necessary when using MS products, and will cause corruption of all
5909 documents that use 8-bit character sets other than Latin-1. It's mostly
5910 worthwhile for Europeans on non-MS platforms, if weird garbage characters
5911 sometimes appear on some pages, or user agents that don't correct for this
5916 A filter for shockwave haters. As the name suggests, this filter strips
5917 code out of web pages that is used to embed shockwave flash objects.
5921 Change HTML code that embeds Quicktime objects so that kioskmode, which
5922 prevents saving, is disabled.
5926 Text replacements for subversive browsing fun. Make fun of your favorite
5927 Monopolist or play buzzword bingo.
5931 A demonstration-only filter that shows how Privoxy can be used to delete
5932 web content on a keyword basis.
5936 An experimental collection of text replacements to disable malicious HTML
5937 and JavaScript code that exploits known security holes in Internet
5940 Presently, it only protects against Nimda and a cross-site scripting bug,
5941 and would need active maintenance to provide more substantial protection.
5945 Some web sites have very specific problems, the cure for which doesn't
5946 apply anywhere else, or could even cause damage on other sites.
5948 This is a collection of such site-specific cures which should only be
5949 applied to the sites they were intended for, which is what the supplied
5950 default.action file does. Users shouldn't need to change anything regarding
5955 A CSS based block for Google text ads. Also removes a width limitation and
5956 the toolbar advertisement.
5960 Another CSS based block, this time for Yahoo text ads. And removes a width
5965 Another CSS based block, this time for MSN text ads. And removes tracking
5966 URLs, as well as a width limitation.
5970 Cleans up some Blogspot blogs. Read the fine print before using this one!
5972 This filter also intentionally removes some navigation stuff and sets the
5973 page width to 100%. As a result, some rounded "corners" would appear to
5974 early or not at all and as fixing this would require a browser that
5975 understands background-size (CSS3), they are removed instead.
5979 Server-header filter to change the Content-Type from xml to html.
5983 Server-header filter to change the Content-Type from html to xml.
5987 Removes the non-standard ping attribute from anchor and area HTML tags.
5989 hide-tor-exit-notation
5991 Client-header filter to remove the Tor exit node notation found in Host and
5994 If Privoxy and Tor are chained and Privoxy is configured to use socks4a,
5995 one can use "http://www.example.org.foobar.exit/" to access the host
5996 "www.example.org" through the Tor exit node "foobar".
5998 As the HTTP client isn't aware of this notation, it treats the whole string
5999 "www.example.org.foobar.exit" as host and uses it for the "Host" and
6000 "Referer" headers. From the server's point of view the resulting headers
6001 are invalid and can cause problems.
6003 An invalid "Referer" header can trigger "hot-linking" protections, an
6004 invalid "Host" header will make it impossible for the server to find the
6005 right vhost (several domains hosted on the same IP address).
6007 This client-header filter removes the "foo.exit" part in those headers to
6008 prevent the mentioned problems. Note that it only modifies the HTTP
6009 headers, it doesn't make it impossible for the server to detect your Tor
6010 exit node based on the IP address the request is coming from.
6012 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6014 10. Privoxy's Template Files
6016 All Privoxy built-in pages, i.e. error pages such as the "404 - No Such Domain"
6017 error page, the "BLOCKED" page and all pages of its web-based user interface,
6018 are generated from templates. (Privoxy must be running for the above links to
6021 These templates are stored in a subdirectory of the configuration directory
6022 called templates. On Unixish platforms, this is typically /etc/privoxy/
6025 The templates are basically normal HTML files, but with place-holders (called
6026 symbols or exports), which Privoxy fills at run time. It is possible to edit
6027 the templates with a normal text editor, should you want to customize them.
6028 (Not recommended for the casual user). Should you create your own custom
6029 templates, you should use the config setting templdir to specify an alternate
6030 location, so your templates do not get overwritten during upgrades.
6032 Note that just like in configuration files, lines starting with # are ignored
6033 when the templates are filled in.
6035 The place-holders are of the form @name@, and you will find a list of available
6036 symbols, which vary from template to template, in the comments at the start of
6037 each file. Note that these comments are not always accurate, and that it's
6038 probably best to look at the existing HTML code to find out which symbols are
6039 supported and what they are filled in with.
6041 A special application of this substitution mechanism is to make whole blocks of
6042 HTML code disappear when a specific symbol is set. We use this for many
6043 purposes, one of them being to include the beta warning in all our user
6044 interface (CGI) pages when Privoxy is in an alpha or beta development stage:
6046 <!-- @if-unstable-start -->
6048 ... beta warning HTML code goes here ...
6050 <!-- if-unstable-end@ -->
6053 If the "unstable" symbol is set, everything in between and including
6054 @if-unstable-start and if-unstable-end@ will disappear, leaving nothing but an
6060 There's also an if-then-else construct and an #include mechanism, but you'll
6061 sure find out if you are inclined to edit the templates ;-)
6063 All templates refer to a style located at http://config.privoxy.org/
6064 send-stylesheet. This is, of course, locally served by Privoxy and the source
6065 for it can be found and edited in the cgi-style.css template.
6067 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6069 11. Contacting the Developers, Bug Reporting and Feature Requests
6071 We value your feedback. In fact, we rely on it to improve Privoxy and its
6072 configuration. However, please note the following hints, so we can provide you
6073 with the best support:
6075 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6079 For casual users, our support forum at SourceForge is probably best suited:
6080 http://sourceforge.net/tracker/?group_id=11118&atid=211118
6082 All users are of course welcome to discuss their issues on the users mailing
6083 list, where the developers also hang around.
6085 Note that the Privoxy mailing lists are moderated. Posts from unsubscribed
6086 addresses have to be accepted manually by a moderator. This may cause a delay
6087 of several days and if you use a subject that doesn't clearly mention Privoxy
6088 or one of its features, your message may be accidentally discarded as spam.
6090 If you aren't subscribed, you should therefore spend a few seconds to come up
6091 with a proper subject. Additionally you should make it clear that you want to
6092 get CC'd. Otherwise some responses will be directed to the mailing list only,
6093 and you won't see them.
6095 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6097 11.2. Reporting Problems
6099 "Problems" for our purposes, come in two forms:
6101 • Configuration issues, such as ads that slip through, or sites that don't
6102 function properly due to one Privoxy "action" or another being turned "on".
6104 • "Bugs" in the programming code that makes up Privoxy, such as that might
6107 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6109 11.2.1. Reporting Ads or Other Configuration Problems
6111 Please send feedback on ads that slipped through, innocent images that were
6112 blocked, sites that don't work properly, and other configuration related
6113 problem of default.action file, to http://sourceforge.net/tracker/?group_id=
6114 11118&atid=460288, the Actions File Tracker.
6116 New, improved default.action files may occasionally be made available based on
6117 your feedback. These will be announced on the ijbswa-announce list and
6118 available from our the files section of our project page.
6120 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6122 11.2.2. Reporting Bugs
6124 Please report all bugs through our bug tracker: http://sourceforge.net/tracker
6125 /?group_id=11118&atid=111118.
6127 Before doing so, please make sure that the bug has not already been submitted
6128 and observe the additional hints at the top of the submit form. If already
6129 submitted, please feel free to add any info to the original report that might
6130 help to solve the issue.
6132 Please try to verify that it is a Privoxy bug, and not a browser or site bug or
6133 documented behaviour that just happens to be different than what you expected.
6134 If unsure, try toggling off Privoxy, and see if the problem persists.
6136 If you are using your own custom configuration, please try the stock configs to
6137 see if the problem is configuration related. If you're having problems with a
6138 feature that is disabled by default, please ask around on the mailing list if
6139 others can reproduce the problem.
6141 If you aren't using the latest Privoxy version, the bug may have been found and
6142 fixed in the meantime. We would appreciate if you could take the time to
6143 upgrade to the latest version (or even the latest CVS snapshot) and verify that
6144 your bug still exists.
6146 Please be sure to provide the following information:
6148 • The exact Privoxy version you are using (if you got the source from CVS,
6149 please also provide the source code revisions as shown in http://
6150 config.privoxy.org/show-version).
6152 • The operating system and versions you run Privoxy on, (e.g. Windows XP
6153 SP2), if you are using a Unix flavor, sending the output of "uname -a"
6154 should do, in case of GNU/Linux, please also name the distribution.
6156 • The name, platform, and version of the browser you were using (e.g.
6157 Internet Explorer v5.5 for Mac).
6159 • The URL where the problem occurred, or some way for us to duplicate the
6160 problem (e.g. http://somesite.example.com/?somethingelse=123).
6162 • Whether your version of Privoxy is one supplied by the Privoxy developers
6163 via SourceForge, or if you got your copy somewhere else.
6165 • Whether you are using Privoxy in tandem with another proxy such as Tor. If
6166 so, please temporary disable the other proxy to see if the symptoms change.
6168 • Whether you are using a personal firewall product. If so, does Privoxy work
6171 • Any other pertinent information to help identify the problem such as config
6172 or log file excerpts (yes, you should have log file entries for each action
6175 You don't have to tell us your actual name when filing a problem report, but
6176 please use a nickname so we can differentiate between your messages and the
6177 ones entered by other "anonymous" users that may respond to your request if
6178 they have the same problem or already found a solution.
6180 Please also check the status of your request a few days after submitting it, as
6181 we may request additional information. If you use a SF id, you should
6182 automatically get a mail when someone responds to your request.
6184 The appendix of the Privoxy User Manual also has helpful information on
6185 understanding actions, and action debugging.
6187 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6189 11.3. Request New Features
6191 You are welcome to submit ideas on new features or other proposals for
6192 improvement through our feature request tracker at http://sourceforge.net/
6193 tracker/?atid=361118&group_id=11118.
6195 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6199 For any other issues, feel free to use the mailing lists. Technically
6200 interested users and people who wish to contribute to the project are also
6201 welcome on the developers list! You can find an overview of all Privoxy-related
6202 mailing lists, including list archives, at: http://sourceforge.net/mail/?
6205 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6207 12. Privoxy Copyright, License and History
6209 Copyright 2001-2007 by Privoxy Developers <
6210 ijbswa-developers@lists.sourceforge.net>
6212 Some source code is based on code Copyright 1997 by Anonymous Coders and
6213 Junkbusters, Inc. and licensed under the GNU General Public License.
6215 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6219 Privoxy is free software; you can redistribute it and/or modify it under the
6220 terms of the GNU General Public License, version 2, as published by the Free
6221 Software Foundation.
6223 This program is distributed in the hope that it will be useful, but WITHOUT ANY
6224 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
6225 PARTICULAR PURPOSE. See the GNU General Public License for more details, which
6226 is available from the Free Software Foundation, Inc, 51 Franklin Street, Fifth
6227 Floor, Boston, MA 02110-1301, USA
6229 You should have received a copy of the GNU General Public License along with
6230 this program; if not, write to the
6233 Foundation, Inc. 51 Franklin Street, Fifth Floor
6234 Boston, MA 02110-1301
6237 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6241 A long time ago, there was the Internet Junkbuster, by Anonymous Coders and
6242 Junkbusters Corporation. This saved many users a lot of pain in the early days
6243 of web advertising and user tracking.
6245 But the web, its protocols and standards, and with it, the techniques for
6246 forcing ads on users, give up autonomy over their browsing, and for tracking
6247 them, keeps evolving. Unfortunately, the Internet Junkbuster did not. Version
6248 2.0.2, published in 1998, was (and is) the last official release available from
6249 Junkbusters Corporation. Fortunately, it had been released under the GNU GPL,
6250 which allowed further development by others.
6252 So Stefan Waldherr started maintaining an improved version of the software, to
6253 which eventually a number of people contributed patches. It could already
6254 replace banners with a transparent image, and had a first version of pop-up
6255 killing, but it was still very closely based on the original, with all its
6256 limitations, such as the lack of HTTP/1.1 support, flexible per-site
6257 configuration, or content modification. The last release from this effort was
6258 version 2.0.2-10, published in 2000.
6260 Then, some developers picked up the thread, and started turning the software
6261 inside out, upside down, and then reassembled it, adding many new features
6264 The result of this is Privoxy, whose first stable version, 3.0, was released
6267 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6271 Current Privoxy Team:
6273 Fabian Keil, lead developer
6274 David Schmidt, developer
6280 Former Privoxy Team Members:
6305 Thanks to the many people who have tested Privoxy, reported bugs, provided
6306 patches, made suggestions or contributed in some way. These include (in
6307 alphabetical order):
6363 Privoxy is based in part on code originally developed by Junkbusters Corp. and
6366 Privoxy heavily relies on Philip Hazel's PCRE.
6368 The code to filter compressed content makes use of zlib which is written by
6369 Jean-loup Gailly and Mark Adler.
6371 On systems that lack snprintf(), Privoxy is using a version written by Mark
6372 Martinec. On systems that lack strptime(), Privoxy is using the one from the
6373 GNU C Library written by Ulrich Drepper.
6375 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6379 Other references and sites of interest to Privoxy users:
6381 http://www.privoxy.org/, the Privoxy Home page.
6383 http://www.privoxy.org/faq/, the Privoxy FAQ.
6385 http://sourceforge.net/projects/ijbswa/, the Project Page for Privoxy on
6388 http://config.privoxy.org/, the web-based user interface. Privoxy must be
6389 running for this to work. Shortcut: http://p.p/
6391 http://sourceforge.net/tracker/?group_id=11118&atid=460288, to submit "misses"
6392 and other configuration related suggestions to the developers.
6394 http://www.junkbusters.com/ht/en/cookies.html, an explanation how cookies are
6395 used to track web users.
6397 http://www.junkbusters.com/ijb.html, the original Internet Junkbuster.
6399 http://privacy.net/, a useful site to check what information about you is
6400 leaked while you browse the web.
6402 http://www.squid-cache.org/, a popular caching proxy, which is often used
6403 together with Privoxy.
6405 http://www.pps.jussieu.fr/~jch/software/polipo/, Polipo is a caching proxy with
6406 advanced features like pipelining, multiplexing and caching of partial
6407 instances. In many setups it can be used as Squid replacement.
6409 http://tor.eff.org/, Tor can help anonymize web browsing, web publishing,
6410 instant messaging, IRC, SSH, and other applications.
6412 http://www.privoxy.org/developer-manual/, the Privoxy developer manual.
6414 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6418 14.1. Regular Expressions
6420 Privoxy uses Perl-style "regular expressions" in its actions files and filter
6421 file, through the PCRE and PCRS libraries.
6423 If you are reading this, you probably don't understand what "regular
6424 expressions" are, or what they can do. So this will be a very brief
6425 introduction only. A full explanation would require a book ;-)
6427 Regular expressions provide a language to describe patterns that can be run
6428 against strings of characters (letter, numbers, etc), to see if they match the
6429 string or not. The patterns are themselves (sometimes complex) strings of
6430 literal characters, combined with wild-cards, and other special characters,
6431 called meta-characters. The "meta-characters" have special meanings and are
6432 used to build complex patterns to be matched against. Perl Compatible Regular
6433 Expressions are an especially convenient "dialect" of the regular expression
6436 To make a simple analogy, we do something similar when we use wild-card
6437 characters when listing files with the dir command in DOS. *.* matches all
6438 filenames. The "special" character here is the asterisk which matches any and
6439 all characters. We can be more specific and use ? to match just individual
6440 characters. So "dir file?.text" would match "file1.txt", "file2.txt", etc. We
6441 are pattern matching, using a similar technique to "regular expressions"!
6443 Regular expressions do essentially the same thing, but are much, much more
6444 powerful. There are many more "special characters" and ways of building complex
6445 patterns however. Let's look at a few of the common ones, and then some
6448 . - Matches any single character, e.g. "a", "A", "4", ":", or "@".
6450 ? - The preceding character or expression is matched ZERO or ONE times. Either/
6453 + - The preceding character or expression is matched ONE or MORE times.
6455 * - The preceding character or expression is matched ZERO or MORE times.
6457 \ - The "escape" character denotes that the following character should be taken
6458 literally. This is used where one of the special characters (e.g. ".") needs to
6459 be taken literally and not as a special meta-character. Example: "example
6460 \.com", makes sure the period is recognized only as a period (and not expanded
6461 to its meta-character meaning of any single character).
6463 [ ] - Characters enclosed in brackets will be matched if any of the enclosed
6464 characters are encountered. For instance, "[0-9]" matches any numeric digit
6465 (zero through nine). As an example, we can combine this with "+" to match any
6466 digit one of more times: "[0-9]+".
6468 ( ) - parentheses are used to group a sub-expression, or multiple
6471 | - The "bar" character works like an "or" conditional statement. A match is
6472 successful if the sub-expression on either side of "|" matches. As an example:
6473 "/(this|that) example/" uses grouping and the bar character and would match
6474 either "this example" or "that example", and nothing else.
6476 These are just some of the ones you are likely to use when matching URLs with
6477 Privoxy, and is a long way from a definitive list. This is enough to get us
6478 started with a few simple examples which may be more illuminating:
6480 /.*/banners/.* - A simple example that uses the common combination of "." and
6481 "*" to denote any character, zero or more times. In other words, any string at
6482 all. So we start with a literal forward slash, then our regular expression
6483 pattern (".*") another literal forward slash, the string "banners", another
6484 forward slash, and lastly another ".*". We are building a directory path here.
6485 This will match any file with the path that has a directory named "banners" in
6486 it. The ".*" matches any characters, and this could conceivably be more forward
6487 slashes, so it might expand into a much longer looking path. For example, this
6488 could match: "/eye/hate/spammers/banners/annoy_me_please.gif", or just "/
6489 banners/annoying.html", or almost an infinite number of other possible
6490 combinations, just so it has "banners" in the path somewhere.
6492 And now something a little more complex:
6494 /.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward
6495 slashes again ("/"), so we are building another expression that is a file path
6496 statement. We have another ".*", so we are matching against any conceivable
6497 sub-path, just so it matches our expression. The only true literal that must
6498 match our pattern is adv, together with the forward slashes. What comes after
6499 the "adv" string is the interesting part.
6501 Remember the "?" means the preceding expression (either a literal character or
6502 anything grouped with "(...)" in this case) can exist or not, since this means
6503 either zero or one match. So "((er)?ts?|ertis(ing|ements?))" is optional, as
6504 are the individual sub-expressions: "(er)", "(ing|ements?)", and the "s". The "
6505 |" means "or". We have two of those. For instance, "(ing|ements?)", can expand
6506 to match either "ing" OR "ements?". What is being done here, is an attempt at
6507 matching as many variations of "advertisement", and similar, as possible. So
6508 this would expand to match just "adv", or "advert", or "adverts", or
6509 "advertising", or "advertisement", or "advertisements". You get the idea. But
6510 it would not match "advertizements" (with a "z"). We could fix that by changing
6511 our regular expression to: "/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/", which
6512 would then match either spelling.
6514 /.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward
6515 slashes. Anything in the square brackets "[ ]" can be matched. This is using
6516 "0-9" as a shorthand expression to mean any digit one through nine. It is the
6517 same as saying "0123456789". So any digit matches. The "+" means one or more of
6518 the preceding expression must be included. The preceding expression here is
6519 what is in the square brackets -- in this case, any digit one through nine.
6520 Then, at the end, we have a grouping: "(gif|jpe?g)". This includes a "|", so
6521 this needs to match the expression on either side of that bar character also. A
6522 simple "gif" on one side, and the other side will in turn match either "jpeg"
6523 or "jpg", since the "?" means the letter "e" is optional and can be matched
6524 once or not at all. So we are building an expression here to match image GIF or
6525 JPEG type image file. It must include the literal string "advert", then one or
6526 more digits, and a "." (which is now a literal, and not a special character,
6527 since it is escaped with "\"), and lastly either "gif", or "jpeg", or "jpg".
6528 Some possible matches would include: "//advert1.jpg", "/nasty/ads/
6529 advert1234.gif", "/banners/from/hell/advert99.jpg". It would not match
6530 "advert1.gif" (no leading slash), or "/adverts232.jpg" (the expression does not
6531 include an "s"), or "/advert1.jsp" ("jsp" is not in the expression anywhere).
6533 We are barely scratching the surface of regular expressions here so that you
6534 can understand the default Privoxy configuration files, and maybe use this
6535 knowledge to customize your own installation. There is much, much more that can
6536 be done with regular expressions. Now that you know enough to get started, you
6537 can learn more on your own :/
6539 More reading on Perl Compatible Regular expressions: http://perldoc.perl.org/
6542 For information on regular expression based substitutions and their
6543 applications in filters, please see the filter file tutorial in this manual.
6545 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6547 14.2. Privoxy's Internal Pages
6549 Since Privoxy proxies each requested web page, it is easy for Privoxy to trap
6550 certain special URLs. In this way, we can talk directly to Privoxy, and see how
6551 it is configured, see how our rules are being applied, change these rules and
6552 other configuration options, and even turn Privoxy's filtering off, all with a
6555 The URLs listed below are the special ones that allow direct access to Privoxy.
6556 Of course, Privoxy must be running to access these. If not, you will get a
6557 friendly error message. Internet access is not necessary either.
6559 • Privoxy main page:
6561 http://config.privoxy.org/
6563 There is a shortcut: http://p.p/ (But it doesn't provide a fall-back to a
6564 real page, in case the request is not sent through Privoxy)
6566 • Show information about the current configuration, including viewing and
6567 editing of actions files:
6569 http://config.privoxy.org/show-status
6571 • Show the source code version numbers:
6573 http://config.privoxy.org/show-version
6575 • Show the browser's request headers:
6577 http://config.privoxy.org/show-request
6579 • Show which actions apply to a URL and why:
6581 http://config.privoxy.org/show-url-info
6583 • Toggle Privoxy on or off. This feature can be turned off/on in the main
6584 config file. When toggled "off", "Privoxy" continues to run, but only as a
6585 pass-through proxy, with no actions taking place:
6587 http://config.privoxy.org/toggle
6589 Short cuts. Turn off, then on:
6591 http://config.privoxy.org/toggle?set=disable
6593 http://config.privoxy.org/toggle?set=enable
6595 These may be bookmarked for quick reference. See next.
6597 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6599 14.2.1. Bookmarklets
6601 Below are some "bookmarklets" to allow you to easily access a "mini" version of
6602 some of Privoxy's special pages. They are designed for MS Internet Explorer,
6603 but should work equally well in Netscape, Mozilla, and other browsers which
6604 support JavaScript. They are designed to run directly from your bookmarks - not
6605 by clicking the links below (although that should work for testing).
6607 To save them, right-click the link and choose "Add to Favorites" (IE) or "Add
6608 Bookmark" (Netscape). You will get a warning that the bookmark "may not be
6609 safe" - just click OK. Then you can run the Bookmarklet directly from your
6610 favorites/bookmarks. For even faster access, you can put them on the "Links"
6611 bar (IE) or the "Personal Toolbar" (Netscape), and run them with a single
6618 • Privoxy - Toggle Privoxy (Toggles between enabled and disabled)
6620 • Privoxy- View Status
6624 Credit: The site which gave us the general idea for these bookmarklets is
6625 www.bookmarklets.com. They have more information about bookmarklets.
6627 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6629 14.3. Chain of Events
6631 Let's take a quick look at how some of Privoxy's core features are triggered,
6632 and the ensuing sequence of events when a web page is requested by your
6635 • First, your web browser requests a web page. The browser knows to send the
6636 request to Privoxy, which will in turn, relay the request to the remote web
6637 server after passing the following tests:
6639 • Privoxy traps any request for its own internal CGI pages (e.g http://p.p/)
6640 and sends the CGI page back to the browser.
6642 • Next, Privoxy checks to see if the URL matches any "+block" patterns. If
6643 so, the URL is then blocked, and the remote web server will not be
6644 contacted. "+handle-as-image" and "+handle-as-empty-document" are then
6645 checked, and if there is no match, an HTML "BLOCKED" page is sent back to
6646 the browser. Otherwise, if it does match, an image is returned for the
6647 former, and an empty text document for the latter. The type of image would
6648 depend on the setting of "+set-image-blocker" (blank, checkerboard pattern,
6649 or an HTTP redirect to an image elsewhere).
6651 • Untrusted URLs are blocked. If URLs are being added to the trust file, then
6654 • If the URL pattern matches the "+fast-redirects" action, it is then
6655 processed. Unwanted parts of the requested URL are stripped.
6657 • Now the rest of the client browser's request headers are processed. If any
6658 of these match any of the relevant actions (e.g. "+hide-user-agent", etc.),
6659 headers are suppressed or forged as determined by these actions and their
6662 • Now the web server starts sending its response back (i.e. typically a web
6665 • First, the server headers are read and processed to determine, among other
6666 things, the MIME type (document type) and encoding. The headers are then
6667 filtered as determined by the "+crunch-incoming-cookies",
6668 "+session-cookies-only", and "+downgrade-http-version" actions.
6670 • If the "+kill-popups" action applies, and it is an HTML or JavaScript
6671 document, the popup-code in the response is filtered on-the-fly as it is
6674 • If any "+filter" action or "+deanimate-gifs" action applies (and the
6675 document type fits the action), the rest of the page is read into memory
6676 (up to a configurable limit). Then the filter rules (from default.filter
6677 and any other filter files) are processed against the buffered content.
6678 Filters are applied in the order they are specified in one of the filter
6679 files. Animated GIFs, if present, are reduced to either the first or last
6680 frame, depending on the action setting.The entire page, which is now
6681 filtered, is then sent by Privoxy back to your browser.
6683 If neither a "+filter" action or "+deanimate-gifs" matches, then Privoxy
6684 passes the raw data through to the client browser as it becomes available.
6686 • As the browser receives the now (possibly filtered) page content, it reads
6687 and then requests any URLs that may be embedded within the page source,
6688 e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
6689 frames), sounds, etc. For each of these objects, the browser issues a
6690 separate request (this is easily viewable in Privoxy's logs). And each such
6691 request is in turn processed just as above. Note that a complex web page
6692 will have many, many such embedded URLs. If these secondary requests are to
6693 a different server, then quite possibly a very differing set of actions is
6696 NOTE: This is somewhat of a simplistic overview of what happens with each URL
6697 request. For the sake of brevity and simplicity, we have focused on Privoxy's
6700 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6702 14.4. Troubleshooting: Anatomy of an Action
6704 The way Privoxy applies actions and filters to any given URL can be complex,
6705 and not always so easy to understand what is happening. And sometimes we need
6706 to be able to see just what Privoxy is doing. Especially, if something Privoxy
6707 is doing is causing us a problem inadvertently. It can be a little daunting to
6708 look at the actions and filters files themselves, since they tend to be filled
6709 with regular expressions whose consequences are not always so obvious.
6711 One quick test to see if Privoxy is causing a problem or not, is to disable it
6712 temporarily. This should be the first troubleshooting step. See the
6713 Bookmarklets section on a quick and easy way to do this (be sure to flush
6714 caches afterward!). Looking at the logs is a good idea too. (Note that both the
6715 toggle feature and logging are enabled via config file settings, and may need
6718 Another easy troubleshooting step to try is if you have done any customization
6719 of your installation, revert back to the installed defaults and see if that
6720 helps. There are times the developers get complaints about one thing or
6721 another, and the problem is more related to a customized configuration issue.
6723 Privoxy also provides the http://config.privoxy.org/show-url-info page that can
6724 show us very specifically how actions are being applied to any given URL. This
6725 is a big help for troubleshooting.
6727 First, enter one URL (or partial URL) at the prompt, and then Privoxy will tell
6728 us how the current configuration will handle it. This will not help with
6729 filtering effects (i.e. the "+filter" action) from one of the filter files
6730 since this is handled very differently and not so easy to trap! It also will
6731 not tell you about any other URLs that may be embedded within the URL you are
6732 testing. For instance, images such as ads are expressed as URLs within the raw
6733 page source of HTML pages. So you will only get info for the actual URL that is
6734 pasted into the prompt area -- not any sub-URLs. If you want to know about
6735 embedded URLs like ads, you will have to dig those out of the HTML source. Use
6736 your browser's "View Page Source" option for this. Or right click on the ad,
6739 Let's try an example, google.com, and look at it one section at a time in a
6740 sample configuration (your real configuration may vary):
6742 Matches for http://www.google.com:
6744 In file: default.action [ View ] [ Edit ]
6746 {+deanimate-gifs {last}
6747 +fast-redirects {check-decoded-url}
6748 +filter {refresh-tags}
6749 +filter {img-reorder}
6750 +filter {banners-by-size}
6752 +filter {jumping-windows}
6753 +filter {ie-exploits}
6754 +hide-forwarded-for-headers
6755 +hide-from-header {block}
6756 +hide-referrer {forge}
6757 +session-cookies-only
6758 +set-image-blocker {pattern}
6761 { -session-cookies-only }
6767 In file: user.action [ View ] [ Edit ]
6768 (no matches in this file)
6771 This is telling us how we have defined our "actions", and which ones match for
6772 our test case, "google.com". Displayed is all the actions that are available to
6773 us. Remember, the + sign denotes "on". - denotes "off". So some are "on" here,
6774 but many are "off". Each example we try may provide a slightly different end
6775 result, depending on our configuration directives.
6777 The first listing is for our default.action file. The large, multi-line
6778 listing, is how the actions are set to match for all URLs, i.e. our default
6779 settings. If you look at your "actions" file, this would be the section just
6780 below the "aliases" section near the top. This will apply to all URLs as
6781 signified by the single forward slash at the end of the listing -- " / ".
6783 But we have defined additional actions that would be exceptions to these
6784 general rules, and then we list specific URLs (or patterns) that these
6785 exceptions would apply to. Last match wins. Just below this then are two
6786 explicit matches for ".google.com". The first is negating our previous cookie
6787 setting, which was for "+session-cookies-only" (i.e. not persistent). So we
6788 will allow persistent cookies for google, at least that is how it is in this
6789 example. The second turns off any "+fast-redirects" action, allowing this to
6790 take place unmolested. Note that there is a leading dot here -- ".google.com".
6791 This will match any hosts and sub-domains, in the google.com domain also, such
6792 as "www.google.com" or "mail.google.com". But it would not match
6793 "www.google.de"! So, apparently, we have these two actions defined as
6794 exceptions to the general rules at the top somewhere in the lower part of our
6795 default.action file, and "google.com" is referenced somewhere in these latter
6798 Then, for our user.action file, we again have no hits. So there is nothing
6799 google-specific that we might have added to our own, local configuration. If
6800 there was, those actions would over-rule any actions from previously processed
6801 files, such as default.action. user.action typically has the last word. This is
6802 the best place to put hard and fast exceptions,
6804 And finally we pull it all together in the bottom section and summarize how
6805 Privoxy is applying all its "actions" to "google.com":
6811 -client-header-filter{hide-tor-exit-notation}
6812 -content-type-overwrite
6813 -crunch-client-header
6814 -crunch-if-none-match
6815 -crunch-incoming-cookies
6816 -crunch-outgoing-cookies
6817 -crunch-server-header
6818 +deanimate-gifs {last}
6819 -downgrade-http-version
6822 -filter {content-cookies}
6823 -filter {all-popups}
6824 -filter {banners-by-link}
6825 -filter {tiny-textforms}
6826 -filter {frameset-borders}
6827 -filter {demoronizer}
6828 -filter {shockwave-flash}
6829 -filter {quicktime-kioskmode}
6831 -filter {crude-parental}
6832 -filter {site-specifics}
6833 -filter {js-annoyances}
6834 -filter {html-annoyances}
6835 +filter {refresh-tags}
6836 -filter {unsolicited-popups}
6837 +filter {img-reorder}
6838 +filter {banners-by-size}
6840 +filter {jumping-windows}
6841 +filter {ie-exploits}
6848 -handle-as-empty-document
6850 -hide-accept-language
6851 -hide-content-disposition
6852 +hide-forwarded-for-headers
6853 +hide-from-header {block}
6854 -hide-if-modified-since
6855 +hide-referrer {forge}
6860 -overwrite-last-modified
6861 -prevent-compression
6865 -server-header-filter{xml-to-html}
6866 -server-header-filter{html-to-xml}
6867 -session-cookies-only
6868 +set-image-blocker {pattern}
6869 -treat-forbidden-connects-like-blocks
6872 Notice the only difference here to the previous listing, is to "fast-redirects"
6873 and "session-cookies-only", which are activated specifically for this site in
6874 our configuration, and thus show in the "Final Results".
6876 Now another example, "ad.doubleclick.net":
6884 { +block +handle-as-image }
6885 .[a-vx-z]*.doubleclick.net
6888 We'll just show the interesting part here - the explicit matches. It is matched
6889 three different times. Two "+block" sections, and a "+block +handle-as-image",
6890 which is the expanded form of one of our aliases that had been defined as:
6891 "+block-as-image". ("Aliases" are defined in the first section of the actions
6892 file and typically used to combine more than one action.)
6894 Any one of these would have done the trick and blocked this as an unwanted
6895 image. This is unnecessarily redundant since the last case effectively would
6896 also cover the first. No point in taking chances with these guys though ;-)
6897 Note that if you want an ad or obnoxious URL to be invisible, it should be
6898 defined as "ad.doubleclick.net" is done here -- as both a "+block" and an
6899 "+handle-as-image". The custom alias "+block-as-image" just simplifies the
6900 process and make it more readable.
6902 One last example. Let's try "http://www.example.net/adsl/HOWTO/". This one is
6903 giving us problems. We are getting a blank page. Hmmm ...
6905 Matches for http://www.example.net/adsl/HOWTO/:
6907 In file: default.action [ View ] [ Edit ]
6911 -client-header-filter{hide-tor-exit-notation}
6912 -content-type-overwrite
6913 -crunch-client-header
6914 -crunch-if-none-match
6915 -crunch-incoming-cookies
6916 -crunch-outgoing-cookies
6917 -crunch-server-header
6919 -downgrade-http-version
6920 +fast-redirects {check-decoded-url}
6922 -filter {content-cookies}
6923 -filter {all-popups}
6924 -filter {banners-by-link}
6925 -filter {tiny-textforms}
6926 -filter {frameset-borders}
6927 -filter {demoronizer}
6928 -filter {shockwave-flash}
6929 -filter {quicktime-kioskmode}
6931 -filter {crude-parental}
6932 -filter {site-specifics}
6933 -filter {js-annoyances}
6934 -filter {html-annoyances}
6935 +filter {refresh-tags}
6936 -filter {unsolicited-popups}
6937 +filter {img-reorder}
6938 +filter {banners-by-size}
6940 +filter {jumping-windows}
6941 +filter {ie-exploits}
6948 -handle-as-empty-document
6950 -hide-accept-language
6951 -hide-content-disposition
6952 +hide-forwarded-for-headers
6953 +hide-from-header{block}
6954 +hide-referer{forge}
6958 -overwrite-last-modified
6959 +prevent-compression
6963 -server-header-filter{xml-to-html}
6964 -server-header-filter{html-to-xml}
6965 +session-cookies-only
6966 +set-image-blocker{blank}
6967 -treat-forbidden-connects-like-blocks }
6970 { +block +handle-as-image }
6974 Ooops, the "/adsl/" is matching "/ads" in our configuration! But we did not
6975 want this at all! Now we see why we get the blank page. It is actually
6976 triggering two different actions here, and the effects are aggregated so that
6977 the URL is blocked, and Privoxy is told to treat the block as if it were an
6978 image. But this is, of course, all wrong. We could now add a new action below
6979 this (or better in our own user.action file) that explicitly un blocks ( "
6980 {-block}") paths with "adsl" in them (remember, last match in the configuration
6981 wins). There are various ways to handle such exceptions. Example:
6987 Now the page displays ;-) Remember to flush your browser's caches when making
6988 these kinds of changes to your configuration to insure that you get a freshly
6989 delivered page! Or, try using Shift+Reload.
6991 But now what about a situation where we get no explicit matches like we did
6994 { +block +handle-as-image }
6998 That actually was very helpful and pointed us quickly to where the problem was.
6999 If you don't get this kind of match, then it means one of the default rules in
7000 the first section of default.action is causing the problem. This would require
7001 some guesswork, and maybe a little trial and error to isolate the offending
7002 rule. One likely cause would be one of the "+filter" actions. These tend to be
7003 harder to troubleshoot. Try adding the URL for the site to one of aliases that
7008 .worldpay.com # for quietpc.com
7014 "{ shop }" is an "alias" that expands to "{ -filter -session-cookies-only }".
7015 Or you could do your own exception to negate filtering:
7018 # Disable ALL filter actions for sites in this section
7024 This would turn off all filtering for these sites. This is best put in
7025 user.action, for local site exceptions. Note that when a simple domain pattern
7026 is used by itself (without the subsequent path portion), all sub-pages within
7027 that domain are included automatically in the scope of the action.
7029 Images that are inexplicably being blocked, may well be hitting the "+filter
7030 {banners-by-size}" rule, which assumes that images of certain sizes are ad
7031 banners (works well most of the time since these tend to be standardized).
7033 "{ fragile }" is an alias that disables most actions that are the most likely
7034 to cause trouble. This can be used as a last resort for problem sites.
7037 # Handle with care: easy to break
7042 Remember to flush caches! Note that the mail.google reference lacks the TLD
7043 portion (e.g. ".com"). This will effectively match any TLD with google in it,
7044 such as mail.google.de., just as an example.
7046 If this still does not work, you will have to go through the remaining actions
7047 one by one to find which one(s) is causing the problem.