1 Privoxy 3.0.7 User Manual
3 [ Copyright 2001 - 2007 by Privoxy Developers ]
5 $Id: user-manual.sgml,v 2.47 2007/11/18 14:59:47 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 beta version of Privoxy,
216 v.3.0.7, and is mostly complete at this point. The most up to date reference
217 for the time being is still the comments in the source files and in the
218 individual configuration files. Development of a new version is currently
219 nearing completion, and includes significant changes and enhancements over
222 Since this is a beta version, not all new features are well tested. This
223 documentation may be slightly out of sync as a result (especially with CVS
224 sources). And there may be bugs, though hopefully not many!
226 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
230 In addition to the core features of ad blocking and cookie management, Privoxy
231 provides many supplemental features, some of them currently under development,
232 that give the end-user more control, more privacy and more freedom:
234 • Integrated browser based configuration and control utility at http://
235 config.privoxy.org/ (shortcut: http://p.p/). Browser-based tracing of rule
236 and filter effects. Remote toggling.
238 • Web page filtering (text replacements, removes banners based on size,
239 invisible "web-bugs", JavaScript and HTML annoyances, pop-up windows,
240 header manipulation, etc.)
242 • Modularized configuration that allows for standard settings and user
243 settings to reside in separate files, so that installing updated actions
244 files won't overwrite individual user settings.
246 • Support for Perl Compatible Regular Expressions in the configuration files,
247 and generally a more sophisticated and flexible configuration syntax over
250 • Improved cookie management features (e.g. session based cookies).
254 • Bypass many click-tracking scripts (avoids script redirection).
256 • Multi-threaded (POSIX and native threads).
258 • User-customizable HTML templates for all proxy-generated pages (e.g.
261 • Auto-detection and re-reading of config file changes.
263 • Improved signal handling, and a true daemon mode (Unix).
265 • Every feature now controllable on a per-site or per-location basis,
266 configuration more powerful and versatile over-all.
268 • Many smaller new features added, limitations and bugs removed, and security
271 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
275 Privoxy is available both in convenient pre-compiled packages for a wide range
276 of operating systems, and as raw source code. For most users, we recommend
277 using the packages, which can be downloaded from our Privoxy Project Page.
279 Note: On some platforms, the installer may remove previously installed
280 versions, if found. (See below for your platform). In any case be sure to
281 backup your old configuration if it is valuable to you. See the note to
282 upgraders section below.
284 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
288 How to install the binary packages depends on your operating system:
290 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
292 2.1.1. Red Hat and Fedora RPMs
294 RPMs can be installed with rpm -Uvh privoxy-3.0.7-1.rpm, and will use /etc/
295 privoxy for the location of configuration files.
297 Note that on Red Hat, Privoxy will not be automatically started on system boot.
298 You will need to enable that using chkconfig, ntsysv, or similar methods.
300 If you have problems with failed dependencies, try rebuilding the SRC RPM: rpm
301 --rebuild privoxy-3.0.7-1.src.rpm. This will use your locally installed
302 libraries and RPM version.
304 Also note that if you have a Junkbuster RPM installed on your system, you need
305 to remove it first, because the packages conflict. Otherwise, RPM will try to
306 remove Junkbuster automatically if found, before installing Privoxy.
308 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
310 2.1.2. Debian and Ubuntu
312 DEBs can be installed with apt-get install privoxy, and will use /etc/privoxy
313 for the location of configuration files.
315 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
319 Just double-click the installer, which will guide you through the installation
320 process. You will find the configuration files in the same directory as you
321 installed Privoxy in.
323 Version 3.0.5 beta introduced full Windows service functionality. On Windows
324 only, the Privoxy program has two new command line arguments to install and
325 uninstall Privoxy as a service.
329 --install[:service_name]
331 --uninstall[:service_name]
333 After invoking Privoxy with --install, you will need to bring up the Windows
334 service console to assign the user you want Privoxy to run under, and whether
335 or not you want it to run whenever the system starts. You can start the Windows
336 services console with the following command: services.msc. If you do not take
337 the manual step of modifying Privoxy's service settings, it will not start.
338 Note too that you will need to give Privoxy a user account that actually
339 exists, or it will not be permitted to write to its log and configuration
342 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
346 Create a new directory, cd to it, then unzip and untar the archive. For the
347 most part, you'll have to figure out where things go.
349 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
353 First, make sure that no previous installations of Junkbuster and / or Privoxy
354 are left on your system. Check that no Junkbuster or Privoxy objects are in
357 Then, just double-click the WarpIN self-installing archive, which will guide
358 you through the installation process. A shadow of the Privoxy executable will
359 be placed in your startup folder so it will start automatically whenever OS/2
362 The directory you choose to install Privoxy into will contain all of the
365 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
369 Unzip the downloaded file (you can either double-click on the file from the
370 finder, or from the desktop if you downloaded it there). Then, double-click on
371 the package installer icon named Privoxy.pkg and follow the installation
372 process. Privoxy will be installed in the folder /Library/Privoxy. It will
373 start automatically whenever you start up. To prevent it from starting
374 automatically, remove or rename the folder /Library/StartupItems/Privoxy.
376 To start Privoxy by hand, double-click on StartPrivoxy.command in the /Library/
377 Privoxy folder. Or, type this command in the Terminal:
379 /Library/Privoxy/StartPrivoxy.command
383 You will be prompted for the administrator password.
385 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
389 Copy and then unpack the lha archive to a suitable location. All necessary
390 files will be installed into Privoxy directory, including all configuration and
391 log files. To uninstall, just remove this directory.
393 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
397 Privoxy is part of FreeBSD's Ports Collection, you can build and install it
398 with cd /usr/ports/www/privoxy; make install clean.
400 If you don't use the ports, you can fetch and install the package with pkg_add
403 The port skeleton and the package can also be downloaded from the File Release
404 Page, but there's no reason to use them unless you're interested in the beta
405 releases which are only available there.
407 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
411 Gentoo source packages (Ebuilds) for Privoxy are contained in the Gentoo
412 Portage Tree (they are not on the download page, but there is a Gentoo section,
413 where you can see when a new Privoxy Version is added to the Portage Tree).
415 Before installing Privoxy under Gentoo just do first emerge rsync to get the
416 latest changes from the Portage tree. With emerge privoxy you install the
419 Configuration files are in /etc/privoxy, the documentation is in /usr/share/doc
420 /privoxy-3.0.7 and the Log directory is in /var/log/privoxy.
422 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
424 2.2. Building from Source
426 The most convenient way to obtain the Privoxy sources is to download the source
427 tarball from our project download page.
429 If you like to live on the bleeding edge and are not afraid of using possibly
430 unstable development versions, you can check out the up-to-the-minute version
431 directly from the CVS repository.
433 To build Privoxy from source, autoconf, GNU make (gmake), and, of course, a C
434 compiler like gcc are required.
436 When building from a source tarball, first unpack the source:
438 tar xzvf privoxy-3.0.7-beta-src* [.tgz or .tar.gz]
439 cd privoxy-3.0.7-beta
442 For retrieving the current CVS sources, you'll need a CVS client installed.
443 Note that sources from CVS are typically development quality, and may not be
444 stable, or well tested. To download CVS source, check the Sourceforge
445 documentation, which might give commands like:
447 cvs -d:pserver:anonymous@ijbswa.cvs.sourceforge.net:/cvsroot/ijbswa login
448 cvs -z3 -d:pserver:anonymous@ijbswa.cvs.sourceforge.net:/cvsroot/ijbswa co current
452 This will create a directory named current/, which will contain the source
455 You can also check out any Privoxy "branch", just exchange the current name
456 with the wanted branch name (Example: v_3_0_branch for the 3.0 cvs tree).
458 It is also strongly recommended to not run Privoxy as root. You should
459 configure/install/run Privoxy as an unprivileged user, preferably by creating a
460 "privoxy" user and group just for this purpose. See your local documentation
461 for the correct command line to do add new users and groups (something like
462 adduser, but the command syntax may vary from platform to platform).
464 /etc/passwd might then look like:
466 privoxy:*:7777:7777:privoxy proxy:/no/home:/no/shell
469 And then /etc/group, like:
474 Some binary packages may do this for you.
476 Then, to build from either unpacked tarball or CVS source:
480 ./configure # (--help to see options)
481 make # (the make from GNU, sometimes called gmake)
482 su # Possibly required
483 make -n install # (to see where all the files will go)
484 make -s install # (to really install, -s to silence output)
487 Using GNU make, you can have the first four steps automatically done for you by
493 in the freshly downloaded or unpacked source directory.
495 To build an executable with security enhanced features so that users cannot
496 easily bypass the proxy (e.g. "Go There Anyway"), or alter their own
497 configurations, configure like this:
499 ./configure --disable-toggle --disable-editor --disable-force
502 Then build as above. In Privoxy 3.0.7 and later, all of these options can also
503 be disabled through the configuration file.
505 WARNING: If installing as root, the install will fail unless a non-root user or
506 group is specified, or a privoxy user and group already exist on the system. If
507 a non-root user is specified, and no group, then the installation will try to
508 also use a group of the same name as "user". If a group is specified (and no
509 user), then the support files will be installed as writable by that group, and
510 owned by the user running the installation.
512 configure accepts --with-user and --with-group options for setting user and
513 group ownership of the configuration files (which need to be writable by the
514 daemon). The specified user must already exist. When starting Privoxy, it must
515 be run as this same user to insure write access to configuration and log files!
517 Alternately, you can specify user and group on the make command line, but be
518 sure both already exist:
520 make -s install USER=privoxy GROUP=privoxy
523 The default installation path for make install is /usr/local. This may of
524 course be customized with the various ./configure path options. If you are
525 doing an install to anywhere besides /usr/local, be sure to set the appropriate
526 paths with the correct configure options (./configure --help). Non-privileged
527 users must of course have write access permissions to wherever the target
528 installation is going.
530 If you do install to /usr/local, the install will use sysconfdir=$prefix/etc/
531 privoxy by default. All other destinations, and the direct usage of
532 --sysconfdir flag behave like normal, i.e. will not add the extra privoxy
533 directory. This is for a safer install, as there may already exist another
534 program that uses a file with the "config" name, and thus makes /usr/local/etc
537 If installing to /usr/local, the documentation will go by default to $prefix/
538 share/doc. But if this directory doesn't exist, it will then try $prefix/doc
539 and install there before creating a new $prefix/share/doc just for Privoxy.
541 Again, if the installs goes to /usr/local, the localstatedir (ie: var/) will
542 default to /var instead of $prefix/var so the logs will go to /var/log/privoxy
543 /, and the pid file will be created in /var/run/privoxy.pid.
545 make install will attempt to set the correct values in config (main
546 configuration file). You should check this to make sure all values are correct.
547 If appropriate, an init script will be installed, but it is up to the user to
548 determine how and where to start Privoxy. The init script should be checked for
549 correct paths and values, if anything other than a default install is done.
551 If install finds previous versions of local configuration files, most of these
552 will not be overwritten, and the new ones will be installed with a "new"
553 extension. default.action, default.filter, and standard.action will be
554 overwritten. You will then need to manually update the other installed
555 configuration files as needed. All template files will be overwritten. If you
556 have customized, local templates, you should save these first, and in fact it
557 is wise to always save any important configuration files "just in case". If a
558 previous version of Privoxy is already running, you will have to restart it
561 For more detailed instructions on how to build Redhat RPMs, Windows
562 self-extracting installers, building on platforms with special requirements
563 etc, please consult the developer manual.
565 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
567 2.3. Keeping your Installation Up-to-Date
569 As user feedback comes in and development continues, we will make updated
570 versions of both the main actions file (as a separate package) and the software
571 itself (including the actions file) available for download.
573 If you wish to receive an email notification whenever we release updates of
574 Privoxy or the actions file, subscribe to our announce mailing list,
575 ijbswa-announce@lists.sourceforge.net.
577 In order not to lose your personal changes and adjustments when updating to the
578 latest default.action file we strongly recommend that you use user.action and
579 user.filter for your local customizations of Privoxy. See the Chapter on
580 actions files for details.
582 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
584 3. What's New in this Release
586 There are many improvements and new features since Privoxy 3.0.6, the last
589 • Two new actions server-header-tagger and client-header-tagger that can be
590 used to create arbitrary "tags" based on client and server headers. These
591 "tags" can then subsequently be used to control the other actions used for
592 the current request, greatly increasing Privoxy's flexibility and
593 selectivity. See tag patterns for more information on tags.
595 • Header filtering is done with dedicated header filters now. As a result the
596 actions "filter-client-headers" and "filter-server-headers" that were
597 introduced with Privoxy 3.0.5 to apply content filters to the headers have
598 been removed. See the new actions server-header-filter and
599 client-header-filter for details.
601 • There are four new options for the main config file:
603 □ allow-cgi-request-crunching which allows requests for Privoxy's
604 internal CGI pages to be blocked, redirected or (un)trusted like
607 □ split-large-forms that will work around a browser bug that caused IE6
608 and IE7 to ignore the Submit button on the Privoxy's
609 edit-actions-for-url CGI page.
611 □ accept-intercepted-requests which allows to combine Privoxy with any
612 packet filter to create an intercepting proxy for HTTP/1.1 requests
613 (and for HTTP/1.0 requests with Host header set). This means clients
614 can be forced to use Privoxy even if their proxy settings are
615 configured differently.
617 □ templdir to designate an alternate location for Privoxy's locally
618 customized CGI templates so that these are not overwritten during
621 • A new command line option --pre-chroot-nslookup hostname to initialize the
622 resolver library before chroot'ing. On some systems this reduces the number
623 of files that must be copied into the chroot tree. (Patch provided by
626 • The forward-override action allows changing of the forwarding settings
627 through the actions files. Combined with tags, this allows to choose the
628 forwarder based on client headers like the User-Agent, or the request
631 • The redirect action can now use regular expression substitutions against
634 • zlib support is now available as a compile time option to filter compressed
635 content. Patch provided by Wil Mahan.
637 • Improve various filters, and add new ones.
639 • Include support for RFC 3253 so that Subversion works with Privoxy. Patch
640 provided by Petr Kadlec.
642 • Logging can be completely turned off by not specifying a logfile directive.
644 • A number of improvements to Privoxy's internal CGI pages, including the use
645 of favicons for error and control pages.
647 • Many bugfixes, memory leaks addressed, code improvements, and logging
650 For a more detailed list of changes please have a look at the ChangeLog.
652 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
654 3.1. Note to Upgraders
656 A quick list of things to be aware of before upgrading from earlier versions of
659 • The recommended way to upgrade Privoxy is to backup your old configuration
660 files, install the new ones, verify that Privoxy is working correctly and
661 finally merge back your changes using diff and maybe patch.
663 There are a number of new features in each Privoxy release and most of them
664 have to be explicitly enabled in the configuration files. Old configuration
665 files obviously don't do that and due to syntax changes using old
666 configuration files with a new Privoxy isn't always possible anyway.
668 • Note that some installers remove earlier versions completely, including
669 configuration files, therefore you should really save any important
672 • On the other hand, other installers don't overwrite existing configuration
673 files, thinking you will want to do that yourself.
675 • standard.action now only includes the enabled actions. Not all actions as
678 • Logging is off by default now. If you need logging, it can be turned on in
679 the config file. You may also want to enable logging until you verified
680 that the new Privoxy version is working as expected.
682 • Three other config file settings are now off by default:
683 enable-remote-toggle, enable-remote-http-toggle, and enable-edit-actions.
684 If you use or want these, you will need to explicitly enable them, and be
685 aware of the security issues involved.
687 • The "filter-client-headers" and "filter-server-headers" actions that were
688 introduced with Privoxy 3.0.5 to apply content filters to the headers have
689 been removed and replaced with new actions. See the What's New section
692 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
694 4. Quickstart to Using Privoxy
696 • Install Privoxy. See the Installation Section below for platform specific
699 • Advanced users and those who want to offer Privoxy service to more than
700 just their local machine should check the main config file, especially the
701 security-relevant options. These are off by default.
703 • Start Privoxy, if the installation program has not done this already (may
704 vary according to platform). See the section Starting Privoxy.
706 • Set your browser to use Privoxy as HTTP and HTTPS (SSL) proxy by setting
707 the proxy configuration for address of 127.0.0.1 and port 8118. DO NOT
708 activate proxying for FTP or any protocols besides HTTP and HTTPS (SSL)
709 unless you intend to prevent your browser from using these protocols.
711 • Flush your browser's disk and memory caches, to remove any cached ad
712 images. If using Privoxy to manage cookies, you should remove any currently
715 • A default installation should provide a reasonable starting point for most.
716 There will undoubtedly be occasions where you will want to adjust the
717 configuration, but that can be dealt with as the need arises. Little to no
718 initial configuration is required in most cases, you may want to enable the
719 web-based action editor though. Be sure to read the warnings first.
721 See the Configuration section for more configuration options, and how to
722 customize your installation. You might also want to look at the next
723 section for a quick introduction to how Privoxy blocks ads and banners.
725 • If you experience ads that slip through, innocent images that are blocked,
726 or otherwise feel the need to fine-tune Privoxy's behavior, take a look at
727 the actions files. As a quick start, you might find the richly commented
728 examples helpful. You can also view and edit the actions files through the
729 web-based user interface. The Appendix "Troubleshooting: Anatomy of an
730 Action" has hints on how to understand and debug actions that "misbehave".
732 • Please see the section Contacting the Developers on how to report bugs,
733 problems with websites or to get help.
735 • Now enjoy surfing with enhanced control, comfort and privacy!
737 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
739 4.1. Quickstart to Ad Blocking
741 Ad blocking is but one of Privoxy's array of features. Many of these features
742 are for the technically minded advanced user. But, ad and banner blocking is
743 surely common ground for everybody.
745 This section will provide a quick summary of ad blocking so you can get up to
746 speed quickly without having to read the more extensive information provided
747 below, though this is highly recommended.
749 First a bit of a warning ... blocking ads is much like blocking SPAM: the more
750 aggressive you are about it, the more likely you are to block things that were
751 not intended. And the more likely that some things may not work as intended. So
752 there is a trade off here. If you want extreme ad free browsing, be prepared to
753 deal with more "problem" sites, and to spend more time adjusting the
754 configuration to solve these unintended consequences. In short, there is not an
755 easy way to eliminate all ads. Either take the easy way and settle for most ads
756 blocked with the default configuration, or jump in and tweak it for your
757 personal surfing habits and preferences.
759 Secondly, a brief explanation of Privoxy's "actions". "Actions" in this
760 context, are the directives we use to tell Privoxy to perform some task
761 relating to HTTP transactions (i.e. web browsing). We tell Privoxy to take some
762 "action". Each action has a unique name and function. While there are many
763 potential actions in Privoxy's arsenal, only a few are used for ad blocking.
764 Actions, and action configuration files, are explained in depth below.
766 Actions are specified in Privoxy's configuration, followed by one or more URLs
767 to which the action should apply. URLs can actually be URL type patterns that
768 use wildcards so they can apply potentially to a range of similar URLs. The
769 actions, together with the URL patterns are called a section.
771 When you connect to a website, the full URL will either match one or more of
772 the sections as defined in Privoxy's configuration, or not. If so, then Privoxy
773 will perform the respective actions. If not, then nothing special happens.
774 Furthermore, web pages may contain embedded, secondary URLs that your web
775 browser will use to load additional components of the page, as it parses the
776 original page's HTML content. An ad image for instance, is just an URL embedded
777 in the page somewhere. The image itself may be on the same server, or a server
778 somewhere else on the Internet. Complex web pages will have many such embedded
779 URLs. Privoxy can deal with each URL individually, so, for instance, the main
780 page text is not touched, but images from such-and-such server are blocked.
782 The most important actions for basic ad blocking are: block, handle-as-image,
783 handle-as-empty-document,and set-image-blocker:
785 • block - this is perhaps the single most used action, and is particularly
786 important for ad blocking. This action stops any contact between your
787 browser and any URL patterns that match this action's configuration. It can
788 be used for blocking ads, but also anything that is determined to be
789 unwanted. By itself, it simply stops any communication with the remote
790 server and sends Privoxy's own built-in BLOCKED page instead to let you now
791 what has happened (with some exceptions, see below).
793 • handle-as-image - tells Privoxy to treat this URL as an image. Privoxy's
794 default configuration already does this for all common image types (e.g.
795 GIF), but there are many situations where this is not so easy to determine.
796 So we'll force it in these cases. This is particularly important for ad
797 blocking, since only if we know that it's an image of some kind, can we
798 replace it with an image of our choosing, instead of the Privoxy BLOCKED
799 page (which would only result in a "broken image" icon). There are some
800 limitations to this though. For instance, you can't just brute-force an
801 image substitution for an entire HTML page in most situations.
803 • handle-as-empty-document - sends an empty document instead of Privoxy's
804 normal BLOCKED HTML page. This is useful for file types that are neither
805 HTML nor images, such as blocking JavaScript files.
807 • set-image-blocker - tells Privoxy what to display in place of an ad image
808 that has hit a block rule. For this to come into play, the URL must match a
809 block action somewhere in the configuration, and, it must also match an
810 handle-as-image action.
812 The configuration options on what to display instead of the ad are:
814 pattern - a checkerboard pattern, so that an ad replacement is obvious.
817 blank - A very small empty GIF image is displayed. This is the so-called
818 "invisible" configuration option.
820 http://<URL> - A redirect to any image anywhere of the user's choosing
823 Advanced users will eventually want to explore Privoxy filters as well. Filters
824 are very different from blocks. A "block" blocks a site, page, or unwanted
825 contented. Filters are a way of filtering or modifying what is actually on the
826 page. An example filter usage: a text replacement of "no-no" for "nasty-word".
827 That is a very simple example. This process can be used for ad blocking, but it
828 is more in the realm of advanced usage and has some pitfalls to be wary off.
830 The quickest way to adjust any of these settings is with your browser through
831 the special Privoxy editor at http://config.privoxy.org/show-status (shortcut:
832 http://p.p/show-status). This is an internal page, and does not require
835 Note that as of Privoxy 3.0.7 beta the action editor is disabled by default.
836 Check the enable-edit-actions section in the configuration file to learn why
837 and in which cases it's safe to enable again.
839 If you decided to enable the action editor, select the appropriate "actions"
840 file, and click "Edit". It is best to put personal or local preferences in
841 user.action since this is not meant to be overwritten during upgrades, and will
842 over-ride the settings in other files. Here you can insert new "actions", and
843 URLs for ad blocking or other purposes, and make other adjustments to the
844 configuration. Privoxy will detect these changes automatically.
846 A quick and simple step by step example:
848 • Right click on the ad image to be blocked, then select "Copy Link Location"
849 from the pop-up menu.
851 • Set your browser to http://config.privoxy.org/show-status
853 • Find user.action in the top section, and click on "Edit":
855 Figure 1. Actions Files in Use
859 • You should have a section with only block listed under "Actions:". If not,
860 click a "Insert new section below" button, and in the new section that just
861 appeared, click the Edit button right under the word "Actions:". This will
862 bring up a list of all actions. Find block near the top, and click in the
863 "Enabled" column, then "Submit" just below the list.
865 • Now, in the block actions section, click the "Add" button, and paste the
866 URL the browser got from "Copy Link Location". Remove the http:// at the
867 beginning of the URL. Then, click "Submit" (or "OK" if in a pop-up window).
869 • Now go back to the original page, and press SHIFT-Reload (or flush all
870 browser caches). The image should be gone now.
872 This is a very crude and simple example. There might be good reasons to use a
873 wildcard pattern match to include potentially similar images from the same
874 site. For a more extensive explanation of "patterns", and the entire actions
875 concept, see the Actions section.
877 For advanced users who want to hand edit their config files, you might want to
878 now go to the Actions Files Tutorial. The ideas explained therein also apply to
879 the web-based editor.
881 There are also various filters that can be used for ad blocking (filters are a
882 special subset of actions). These fall into the "advanced" usage category, and
883 are explained in depth in later sections.
885 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
889 Before launching Privoxy for the first time, you will want to configure your
890 browser(s) to use Privoxy as a HTTP and HTTPS (SSL) proxy. The default is
891 127.0.0.1 (or localhost) for the proxy address, and port 8118 (earlier versions
892 used port 8000). This is the one configuration step that must be done!
894 Please note that Privoxy can only proxy HTTP and HTTPS traffic. It will not
895 work with FTP or other protocols.
897 Figure 2. Proxy Configuration Showing Mozilla/Netscape HTTP and HTTPS (SSL)
902 With Firefox, this is typically set under:
904 Tools -> Options -> General -> Connection Settings -> Manual Proxy
908 Or optionally on some platforms:
910 Edit -> Preferences -> General -> Connection Settings -> Manual Proxy
914 With Netscape (and Mozilla), this can be set under:
916 Edit -> Preferences -> Advanced -> Proxies -> HTTP Proxy
919 For Internet Explorer v.5-6:
921 Tools -> Internet Options -> Connections -> LAN Settings
923 Then, check "Use Proxy" and fill in the appropriate info (Address: 127.0.0.1,
924 Port: 8118). Include HTTPS (SSL), if you want HTTPS proxy support too
925 (sometimes labeled "Secure"). Make sure any checkboxes like "Use the same proxy
926 server for all protocols" is UNCHECKED. You want only HTTP and HTTPS (SSL)!
928 Figure 3. Proxy Configuration Showing Internet Explorer HTTP and HTTPS (Secure)
933 After doing this, flush your browser's disk and memory caches to force a
934 re-reading of all pages and to get rid of any ads that may be cached. Remove
935 any cookies, if you want Privoxy to manage that. You are now ready to start
936 enjoying the benefits of using Privoxy!
938 Privoxy itself is typically started by specifying the main configuration file
939 to be used on the command line. If no configuration file is specified on the
940 command line, Privoxy will look for a file named config in the current
941 directory. Except on Win32 where it will try config.txt.
943 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
945 5.1. Red Hat and Fedora
947 A default Red Hat installation may not start Privoxy upon boot. It will use the
948 file /etc/privoxy/config as its main configuration file.
950 # /etc/rc.d/init.d/privoxy start
955 # service privoxy start
958 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
962 We use a script. Note that Debian typically starts Privoxy upon booting per
963 default. It will use the file /etc/privoxy/config as its main configuration
966 # /etc/init.d/privoxy start
969 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
973 Click on the Privoxy Icon to start Privoxy. If no configuration file is
974 specified on the command line, Privoxy will look for a file named config.txt.
975 Note that Windows will automatically start Privoxy when the system starts if
976 you chose that option when installing.
978 Privoxy can run with full Windows service functionality. On Windows only, the
979 Privoxy program has two new command line arguments to install and uninstall
980 Privoxy as a service. See the Windows Installation instructions for details.
982 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
984 5.4. Solaris, NetBSD, FreeBSD, HP-UX and others
986 Example Unix startup command:
988 # /usr/sbin/privoxy /etc/privoxy/config
991 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
995 During installation, Privoxy is configured to start automatically when the
996 system restarts. You can start it manually by double-clicking on the Privoxy
997 icon in the Privoxy folder.
999 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1003 During installation, Privoxy is configured to start automatically when the
1004 system restarts. To start Privoxy manually, double-click on the
1005 StartPrivoxy.command icon in the /Library/Privoxy folder. Or, type this command
1008 /Library/Privoxy/StartPrivoxy.command
1012 You will be prompted for the administrator password.
1014 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1018 Start Privoxy (with RUN <>NIL:) in your startnet script (AmiTCP), in
1019 s:user-startup (RoadShow), as startup program in your startup script (Genesis),
1020 or as startup action (Miami and MiamiDx). Privoxy will automatically quit when
1021 you quit your TCP/IP stack (just ignore the harmless warning your TCP/IP stack
1022 may display that Privoxy is still running).
1024 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1028 A script is again used. It will use the file /etc/privoxy/config as its main
1031 /etc/init.d/privoxy start
1035 Note that Privoxy is not automatically started at boot time by default. You can
1036 change this with the rc-update command.
1038 rc-update add privoxy default
1042 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1044 5.9. Command Line Options
1046 Privoxy may be invoked with the following command-line options:
1050 Print version info and exit. Unix only.
1054 Print short usage info and exit. Unix only.
1058 Don't become a daemon, i.e. don't fork and become process group leader, and
1059 don't detach from controlling tty. Unix only.
1063 On startup, write the process ID to FILE. Delete the FILE on exit. Failure
1064 to create or delete the FILE is non-fatal. If no FILE option is given, no
1065 PID file will be used. Unix only.
1067 • --user USER[.GROUP]
1069 After (optionally) writing the PID file, assume the user ID of USER, and if
1070 included the GID of GROUP. Exit if the privileges are not sufficient to do
1075 Before changing to the user ID given in the --user option, chroot to that
1076 user's home directory, i.e. make the kernel pretend to the Privoxy process
1077 that the directory tree starts there. If set up carefully, this can limit
1078 the impact of possible vulnerabilities in Privoxy to the files contained in
1079 that hierarchy. Unix only.
1081 • --pre-chroot-nslookup hostname
1083 Specifies a hostname to look up before doing a chroot. On some systems,
1084 initializing the resolver library involves reading config files from /etc
1085 and/or loading additional shared libraries from /lib. On these systems,
1086 doing a hostname lookup before the chroot reduces the number of files that
1087 must be copied into the chroot tree.
1089 For fastest startup speed, a good value is a hostname that is not in /etc/
1090 hosts but that your local name server (listed in /etc/resolv.conf) can
1091 resolve without recursion (that is, without having to ask any other name
1092 servers). The hostname need not exist, but if it doesn't, an error message
1093 (which can be ignored) will be output.
1097 If no configfile is included on the command line, Privoxy will look for a
1098 file named "config" in the current directory (except on Win32 where it will
1099 look for "config.txt" instead). Specify full path to avoid confusion. If no
1100 config file is found, Privoxy will fail to start.
1102 On MS Windows only there are two additional command-line options to allow
1103 Privoxy to install and run as a service. See the Window Installation section
1106 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1108 6. Privoxy Configuration
1110 All Privoxy configuration is stored in text files. These files can be edited
1111 with a text editor. Many important aspects of Privoxy can also be controlled
1112 easily with a web browser.
1114 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1116 6.1. Controlling Privoxy with Your Web Browser
1118 Privoxy's user interface can be reached through the special URL http://
1119 config.privoxy.org/ (shortcut: http://p.p/), which is a built-in page and works
1120 without Internet access. You will see the following section:
1123 ▪ View & change the current configuration
1124 ▪ View the source code version numbers
1125 ▪ View the request headers.
1126 ▪ Look up which actions apply to a URL and why
1127 ▪ Toggle Privoxy on or off
1131 This should be self-explanatory. Note the first item leads to an editor for the
1132 actions files, which is where the ad, banner, cookie, and URL blocking magic is
1133 configured as well as other advanced features of Privoxy. This is an easy way
1134 to adjust various aspects of Privoxy configuration. The actions file, and other
1135 configuration files, are explained in detail below.
1137 "Toggle Privoxy On or Off" is handy for sites that might have problems with
1138 your current actions and filters. You can in fact use it as a test to see
1139 whether it is Privoxy causing the problem or not. Privoxy continues to run as a
1140 proxy in this case, but all manipulation is disabled, i.e. Privoxy acts like a
1141 normal forwarding proxy. There is even a toggle Bookmarklet offered, so that
1142 you can toggle Privoxy with one click from your browser.
1144 Note that several of the features described above are disabled by default in
1145 Privoxy 3.0.7 beta and later. Check the configuration file to learn why and in
1146 which cases it's safe to enable them again.
1148 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1150 6.2. Configuration Files Overview
1152 For Unix, *BSD and Linux, all configuration files are located in /etc/privoxy/
1153 by default. For MS Windows, OS/2, and AmigaOS these are all in the same
1154 directory as the Privoxy executable. The name and number of configuration files
1155 has changed from previous versions, and is subject to change as development
1158 The installed defaults provide a reasonable starting point, though some
1159 settings may be aggressive by some standards. For the time being, the principle
1160 configuration files are:
1162 • The main configuration file is named config on Linux, Unix, BSD, OS/2, and
1163 AmigaOS and config.txt on Windows. This is a required file.
1165 • default.action (the main actions file) is used to define which "actions"
1166 relating to banner-blocking, images, pop-ups, content modification, cookie
1167 handling etc should be applied by default. It also defines many exceptions
1168 (both positive and negative) from this default set of actions that enable
1169 Privoxy to selectively eliminate the junk, and only the junk, on as many
1170 websites as possible.
1172 Multiple actions files may be defined in config. These are processed in the
1173 order they are defined. Local customizations and locally preferred
1174 exceptions to the default policies as defined in default.action (which you
1175 will most probably want to define sooner or later) are probably best
1176 applied in user.action, where you can preserve them across upgrades.
1177 standard.action is only for Privoxy's internal use.
1179 There is also a web based editor that can be accessed from http://
1180 config.privoxy.org/show-status (Shortcut: http://p.p/show-status) for the
1181 various actions files.
1183 • "Filter files" (the filter file) can be used to re-write the raw page
1184 content, including viewable text as well as embedded HTML and JavaScript,
1185 and whatever else lurks on any given web page. The filtering jobs are only
1186 pre-defined here; whether to apply them or not is up to the actions files.
1187 default.filter includes various filters made available for use by the
1188 developers. Some are much more intrusive than others, and all should be
1189 used with caution. You may define additional filter files in config as you
1190 can with actions files. We suggest user.filter for any locally defined
1191 filters or customizations.
1193 The syntax of the configuration and filter files may change between different
1194 Privoxy versions, unfortunately some enhancements cost backwards compatibility.
1196 All files use the "#" character to denote a comment (the rest of the line will
1197 be ignored) and understand line continuation through placing a backslash ("\")
1198 as the very last character in a line. If the # is preceded by a backslash, it
1199 looses its special function. Placing a # in front of an otherwise valid
1200 configuration line to prevent it from being interpreted is called "commenting
1201 out" that line. Blank lines are ignored.
1203 The actions files and filter files can use Perl style regular expressions for
1204 maximum flexibility.
1206 After making any changes, there is no need to restart Privoxy in order for the
1207 changes to take effect. Privoxy detects such changes automatically. Note,
1208 however, that it may take one or two additional requests for the change to take
1209 effect. When changing the listening address of Privoxy, these "wake up"
1210 requests must obviously be sent to the old listening address.
1212 While under development, the configuration content is subject to change. The
1213 below documentation may not be accurate by the time you read this. Also, what
1214 constitutes a "default" setting, may change, so please check all your
1215 configuration files on important issues.
1217 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1219 7. The Main Configuration File
1221 Again, the main configuration file is named config on Linux/Unix/BSD and OS/2,
1222 and config.txt on Windows. Configuration lines consist of an initial keyword
1223 followed by a list of values, all separated by whitespace (any number of spaces
1224 or tabs). For example:
1226 confdir /etc/privoxy
1228 Assigns the value /etc/privoxy to the option confdir and thus indicates that
1229 the configuration directory is named "/etc/privoxy/".
1231 All options in the config file except for confdir and logdir are optional.
1232 Watch out in the below description for what happens if you leave them unset.
1234 The main config file controls all aspects of Privoxy's operation that are not
1235 location dependent (i.e. they apply universally, no matter where you may be
1238 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1240 7.1. Local Set-up Documentation
1242 If you intend to operate Privoxy for more users than just yourself, it might be
1243 a good idea to let them know how to reach you, what you block and why you do
1244 that, your policies, etc.
1246 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1252 Location of the Privoxy User Manual.
1256 A fully qualified URI
1264 http://www.privoxy.org/version/user-manual/ will be used, where version is
1265 the Privoxy version.
1269 The User Manual URI is the single best source of information on Privoxy,
1270 and is used for help links from some of the internal CGI pages. The manual
1271 itself is normally packaged with the binary distributions, so you probably
1272 want to set this to a locally installed copy.
1276 The best all purpose solution is simply to put the full local PATH to where
1277 the User Manual is located:
1279 user-manual /usr/share/doc/privoxy/user-manual
1282 The User Manual is then available to anyone with access to Privoxy, by
1283 following the built-in URL: http://config.privoxy.org/user-manual/ (or the
1284 shortcut: http://p.p/user-manual/).
1286 If the documentation is not on the local system, it can be accessed from a
1289 user-manual http://example.com/privoxy/user-manual/
1292 ┌─────────────────────────────────────────────────────────────────┐
1294 ├─────────────────────────────────────────────────────────────────┤
1295 │If set, this option should be the first option in the config │
1296 │file, because it is used while the config file is being read on │
1298 └─────────────────────────────────────────────────────────────────┘
1300 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1302 7.1.2. trust-info-url
1306 A URL to be displayed in the error page that users will see if access to an
1307 untrusted page is denied.
1315 Two example URLs are provided
1319 No links are displayed on the "untrusted" error page.
1323 The value of this option only matters if the experimental trust mechanism
1324 has been activated. (See trustfile below.)
1326 If you use the trust mechanism, it is a good idea to write up some on-line
1327 documentation about your trust policy and to specify the URL(s) here. Use
1328 multiple times for multiple URLs.
1330 The URL(s) should be added to the trustfile as well, so users don't end up
1331 locked out from the information on why they were locked out in the first
1334 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1336 7.1.3. admin-address
1340 An email address to reach the Privoxy administrator.
1352 No email address is displayed on error pages and the CGI user interface.
1356 If both admin-address and proxy-info-url are unset, the whole "Local
1357 Privoxy Support" box on all generated pages will not be shown.
1359 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1361 7.1.4. proxy-info-url
1365 A URL to documentation about the local Privoxy setup, configuration or
1378 No link to local documentation is displayed on error pages and the CGI user
1383 If both admin-address and proxy-info-url are unset, the whole "Local
1384 Privoxy Support" box on all generated pages will not be shown.
1386 This URL shouldn't be blocked ;-)
1388 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1390 7.2. Configuration and Log File Locations
1392 Privoxy can (and normally does) use a number of other files for additional
1393 configuration, help and logging. This section of the configuration file tells
1394 Privoxy where to find those other files.
1396 The user running Privoxy, must have read permission for all configuration
1397 files, and write permission to any files that would be modified, such as log
1398 files and actions files.
1400 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1406 The directory where the other configuration files are located.
1414 /etc/privoxy (Unix) or Privoxy installation dir (Windows)
1422 No trailing "/", please.
1424 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1430 An alternative directory where the templates are loaded from.
1442 The templates are assumed to be located in confdir/template.
1446 Privoxy's original templates are usually overwritten with each update. Use
1447 this option to relocate customized templates that should be kept. As
1448 template variables might change between updates, you shouldn't expect
1449 templates to work with Privoxy releases other than the one they were part
1452 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1458 The directory where all logging takes place (i.e. where logfile and jarfile
1467 /var/log/privoxy (Unix) or Privoxy installation dir (Windows)
1475 No trailing "/", please.
1477 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1483 The actions file(s) to use
1487 Complete file name, relative to confdir
1491 standard.action # Internal purposes, no editing recommended
1493 default.action # Main actions file
1495 user.action # User customizations
1499 No actions are taken at all. More or less neutral proxying.
1503 Multiple actionsfile lines are permitted, and are in fact recommended!
1505 The default values include standard.action, which is used for internal
1506 purposes and should be loaded, default.action, which is the "main" actions
1507 file maintained by the developers, and user.action, where you can make your
1510 Actions files contain all the per site and per URL configuration for ad
1511 blocking, cookie management, privacy considerations, etc. There is no point
1512 in using Privoxy without at least one actions file.
1514 Note that since Privoxy 3.0.7, the complete filename, including the
1515 ".action" extension has to be specified. The syntax change was necessary to
1516 be consistent with the other file options and to allow previously forbidden
1519 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1525 The filter file(s) to use
1529 File name, relative to confdir
1533 default.filter (Unix) or default.filter.txt (Windows)
1537 No textual content filtering takes place, i.e. all +filter{name} actions in
1538 the actions files are turned neutral.
1542 Multiple filterfile lines are permitted.
1544 The filter files contain content modification rules that use regular
1545 expressions. These rules permit powerful changes on the content of Web
1546 pages, and optionally the headers as well, e.g., you could try to disable
1547 your favorite JavaScript annoyances, re-write the actual displayed text, or
1548 just have some fun playing buzzword bingo with web pages.
1550 The +filter{name} actions rely on the relevant filter (name) to be defined
1553 A pre-defined filter file called default.filter that contains a number of
1554 useful filters for common problems is included in the distribution. See the
1555 section on the filter action for a list.
1557 It is recommended to place any locally adapted filters into a separate
1558 file, such as user.filter.
1560 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1570 File name, relative to logdir
1574 Unset (commented out). When activated: logfile (Unix) or privoxy.log
1579 Logging is disabled unless --no-daemon mode is used.
1583 The logfile is where all logging and error messages are written. The level
1584 of detail and number of messages are set with the debug option (see below).
1585 The logfile can be useful for tracking down a problem with Privoxy (e.g.,
1586 it's not blocking an ad you think it should block) and it can help you to
1587 monitor what your browser is doing.
1589 Many users will never look at it, however, and it's a privacy risk if third
1590 parties can get access to it. It is therefore disabled by default in
1591 Privoxy 3.0.7 and later.
1593 For troubleshooting purposes, you will have to explicitly enable it. Please
1594 don't file any support requests without trying to reproduce the problem
1595 with logging enabled first. Once you read the log messages, you may even be
1596 able to solve the problem on your own.
1598 Your logfile will grow indefinitely, and you will probably want to
1599 periodically remove it. On Unix systems, you can do this with a cron job
1600 (see "man cron"). For Red Hat based Linux distributions, a logrotate script
1603 Any log files must be writable by whatever user Privoxy is being run as (on
1604 Unix, default user id is "privoxy").
1606 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1612 The file to store intercepted cookies in
1616 File name, relative to logdir
1620 Unset (commented out). When activated: jarfile (Unix) or privoxy.jar
1625 Intercepted cookies are not stored in a dedicated log file.
1629 The jarfile may grow to ridiculous sizes over time.
1631 If debug 8 (show header parsing) is enabled, cookies are also written to
1632 the logfile with the rest of the headers. Therefore this option isn't very
1633 useful and may be removed in future releases. Please report to the
1634 developers if you are still using it.
1636 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1642 The name of the trust file to use
1646 File name, relative to confdir
1650 Unset (commented out). When activated: trust (Unix) or trust.txt (Windows)
1654 The entire trust mechanism is disabled.
1658 The trust mechanism is an experimental feature for building white-lists and
1659 should be used with care. It is NOT recommended for the casual user.
1661 If you specify a trust file, Privoxy will only allow access to sites that
1662 are specified in the trustfile. Sites can be listed in one of two ways:
1664 Prepending a ~ character limits access to this site only (and any sub-paths
1665 within this site), e.g. ~www.example.com allows access to ~www.example.com/
1666 features/news.html, etc.
1668 Or, you can designate sites as trusted referrers, by prepending the name
1669 with a + character. The effect is that access to untrusted sites will be
1670 granted -- but only if a link from this trusted referrer was used to get
1671 there. The link target will then be added to the "trustfile" so that
1672 future, direct accesses will be granted. Sites added via this mechanism do
1673 not become trusted referrers themselves (i.e. they are added with a ~
1674 designation). There is a limit of 512 such entries, after which new entries
1677 If you use the + operator in the trust file, it may grow considerably over
1680 It is recommended that Privoxy be compiled with the --disable-force,
1681 --disable-toggle and --disable-editor options, if this feature is to be
1684 Possible applications include limiting Internet access for children.
1686 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1690 These options are mainly useful when tracing a problem. Note that you might
1691 also want to invoke Privoxy with the --no-daemon command line option when
1694 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1700 Key values that determine what information gets logged to the logfile.
1708 12289 (i.e.: URLs plus informational and warning messages)
1712 Nothing gets logged.
1716 The available debug levels are:
1718 debug 1 # show each GET/POST/CONNECT request
1719 debug 2 # show each connection status
1720 debug 4 # show I/O status
1721 debug 8 # show header parsing
1722 debug 16 # log all data written to the network into the logfile
1723 debug 32 # debug force feature
1724 debug 64 # debug regular expression filters
1725 debug 128 # debug redirects
1726 debug 256 # debug GIF de-animation
1727 debug 512 # Common Log Format
1728 debug 1024 # debug kill pop-ups
1729 debug 2048 # CGI user interface
1730 debug 4096 # Startup banner and warnings.
1731 debug 8192 # Non-fatal errors
1734 To select multiple debug levels, you can either add them or use multiple
1737 A debug level of 1 is informative because it will show you each request as
1738 it happens. 1, 4096 and 8192 are highly recommended so that you will notice
1739 when things go wrong. The other levels are probably only of interest if you
1740 are hunting down a specific problem. They can produce a hell of an output
1743 If you want to use CLF (Common Log Format), you should set "debug 512" ONLY
1744 and not enable anything else.
1746 Privoxy has a hard-coded limit for the length of log messages. If it's
1747 reached, messages are logged truncated and marked with "... [too long,
1750 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1752 7.3.2. single-threaded
1756 Whether to run only one server thread.
1768 Multi-threaded (or, where unavailable: forked) operation, i.e. the ability
1769 to serve multiple requests simultaneously.
1773 This option is only there for debugging purposes. It will drastically
1776 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1778 7.4. Access Control and Security
1780 This section of the config file controls the security-relevant aspects of
1781 Privoxy's configuration.
1783 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1785 7.4.1. listen-address
1789 The IP address and TCP port on which Privoxy will listen for client
1802 Bind to 127.0.0.1 (localhost), port 8118. This is suitable and recommended
1803 for home users who run Privoxy on the same machine as their browser.
1807 You will need to configure your browser(s) to this proxy address and port.
1809 If you already have another service running on port 8118, or if you want to
1810 serve requests from other machines (e.g. on your local network) as well,
1811 you will need to override the default.
1813 If you leave out the IP address, Privoxy will bind to all interfaces
1814 (addresses) on your machine and may become reachable from the Internet. In
1815 that case, consider using access control lists (ACL's, see below), and/or a
1818 If you open Privoxy to untrusted users, you will also want to make sure
1819 that the following actions are disabled: enable-edit-actions and
1820 enable-remote-toggle
1824 Suppose you are running Privoxy on a machine which has the address
1825 192.168.0.1 on your local private network (192.168.0.0) and has another
1826 outside connection with a different address. You want it to serve requests
1829 listen-address 192.168.0.1:8118
1832 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1838 Initial state of "toggle" status
1850 Act as if toggled on
1854 If set to 0, Privoxy will start in "toggled off" mode, i.e. mostly behave
1855 like a normal, content-neutral proxy with both ad blocking and content
1856 filtering disabled. See enable-remote-toggle below.
1858 The windows version will only display the toggle icon in the system tray if
1859 this option is present.
1861 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1863 7.4.3. enable-remote-toggle
1867 Whether or not the web-based toggle feature may be used
1879 The web-based toggle feature is disabled.
1883 When toggled off, Privoxy mostly acts like a normal, content-neutral proxy,
1884 i.e. doesn't block ads or filter content.
1886 Access to the toggle feature can not be controlled separately by "ACLs" or
1887 HTTP authentication, so that everybody who can access Privoxy (see "ACLs"
1888 and listen-address above) can toggle it for all users. So this option is
1889 not recommended for multi-user environments with untrusted users.
1891 Note that malicious client side code (e.g Java) is also capable of using
1894 As a lot of Privoxy users don't read documentation, this feature is
1895 disabled by default.
1897 Note that you must have compiled Privoxy with support for this feature,
1898 otherwise this option has no effect.
1900 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1902 7.4.4. enable-remote-http-toggle
1906 Whether or not Privoxy recognizes special HTTP headers to change its
1919 Privoxy ignores special HTTP headers.
1923 When toggled on, the client can change Privoxy's behaviour by setting
1924 special HTTP headers. Currently the only supported special header is
1925 "X-Filter: No", to disable filtering for the ongoing request, even if it is
1926 enabled in one of the action files.
1928 This feature is disabled by default. If you are using Privoxy in a
1929 environment with trusted clients, you may enable this feature at your
1930 discretion. Note that malicious client side code (e.g Java) is also capable
1931 of using this feature.
1933 This option will be removed in future releases as it has been obsoleted by
1934 the more general header taggers.
1936 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1938 7.4.5. enable-edit-actions
1942 Whether or not the web-based actions file editor may be used
1954 The web-based actions file editor is disabled.
1958 Access to the editor can not be controlled separately by "ACLs" or HTTP
1959 authentication, so that everybody who can access Privoxy (see "ACLs" and
1960 listen-address above) can modify its configuration for all users.
1962 This option is not recommended for environments with untrusted users and as
1963 a lot of Privoxy users don't read documentation, this feature is disabled
1966 Note that malicious client side code (e.g Java) is also capable of using
1967 the actions editor and you shouldn't enable this options unless you
1968 understand the consequences and are sure your browser is configured
1971 Note that you must have compiled Privoxy with support for this feature,
1972 otherwise this option has no effect.
1974 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
1976 7.4.6. enforce-blocks
1980 Whether the user is allowed to ignore blocks and can "go there anyway".
1992 Blocks are not enforced.
1996 Privoxy is mainly used to block and filter requests as a service to the
1997 user, for example to block ads and other junk that clogs the pipes.
1998 Privoxy's configuration isn't perfect and sometimes innocent pages are
1999 blocked. In this situation it makes sense to allow the user to enforce the
2000 request and have Privoxy ignore the block.
2002 In the default configuration Privoxy's "Blocked" page contains a "go there
2003 anyway" link to adds a special string (the force prefix) to the request
2004 URL. If that link is used, Privoxy will detect the force prefix, remove it
2005 again and let the request pass.
2007 Of course Privoxy can also be used to enforce a network policy. In that
2008 case the user obviously should not be able to bypass any blocks, and that's
2009 what the "enforce-blocks" option is for. If it's enabled, Privoxy hides the
2010 "go there anyway" link. If the user adds the force prefix by hand, it will
2011 not be accepted and the circumvention attempt is logged.
2017 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2019 7.4.7. ACLs: permit-access and deny-access
2023 Who can access what.
2027 src_addr[/src_masklen] [dst_addr[/dst_masklen]]
2029 Where src_addr and dst_addr are IP addresses in dotted decimal notation or
2030 valid DNS names, and src_masklen and dst_masklen are subnet masks in CIDR
2031 notation, i.e. integer values from 2 to 30 representing the length (in
2032 bits) of the network address. The masks and the whole destination part are
2041 Don't restrict access further than implied by listen-address
2045 Access controls are included at the request of ISPs and systems
2046 administrators, and are not usually needed by individual users. For a
2047 typical home user, it will normally suffice to ensure that Privoxy only
2048 listens on the localhost (127.0.0.1) or internal (home) network address by
2049 means of the listen-address option.
2051 Please see the warnings in the FAQ that Privoxy is not intended to be a
2052 substitute for a firewall or to encourage anyone to defer addressing basic
2053 security weaknesses.
2055 Multiple ACL lines are OK. If any ACLs are specified, Privoxy only talks to
2056 IP addresses that match at least one permit-access line and don't match any
2057 subsequent deny-access line. In other words, the last match wins, with the
2058 default being deny-access.
2060 If Privoxy is using a forwarder (see forward below) for a particular
2061 destination URL, the dst_addr that is examined is the address of the
2062 forwarder and NOT the address of the ultimate target. This is necessary
2063 because it may be impossible for the local Privoxy to determine the IP
2064 address of the ultimate target (that's often what gateways are used for).
2066 You should prefer using IP addresses over DNS names, because the address
2067 lookups take time. All DNS names must resolve! You can not use domain
2068 patterns like "*.org" or partial domain names. If a DNS name resolves to
2069 multiple IP addresses, only the first one is used.
2071 Denying access to particular sites by ACL may have undesired side effects
2072 if the site in question is hosted on a machine which also hosts other sites
2077 Explicitly define the default behavior if no ACL and listen-address are
2078 set: "localhost" is OK. The absence of a dst_addr implies that all
2079 destination addresses are OK:
2081 permit-access localhost
2084 Allow any host on the same class C subnet as www.privoxy.org access to
2085 nothing but www.example.com (or other domains hosted on the same system):
2087 permit-access www.privoxy.org/24 www.example.com/32
2090 Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere,
2091 with the exception that 192.168.45.73 may not access the IP address behind
2092 www.dirty-stuff.example.com:
2094 permit-access 192.168.45.64/26
2095 deny-access 192.168.45.73 www.dirty-stuff.example.com
2098 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2104 Maximum size of the buffer for content filtering.
2116 Use a 4MB (4096 KB) limit.
2120 For content filtering, i.e. the +filter and +deanimate-gif actions, it is
2121 necessary that Privoxy buffers the entire document body. This can be
2122 potentially dangerous, since a server could just keep sending data
2123 indefinitely and wait for your RAM to exhaust -- with nasty consequences.
2126 When a document buffer size reaches the buffer-limit, it is flushed to the
2127 client unfiltered and no further attempt to filter the rest of the document
2128 is made. Remember that there may be multiple threads running, which might
2129 require up to buffer-limit Kbytes each, unless you have enabled
2130 "single-threaded" above.
2132 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2136 This feature allows routing of HTTP requests through a chain of multiple
2139 Forwarding can be used to chain Privoxy with a caching proxy to speed up
2140 browsing. Using a parent proxy may also be necessary if the machine that
2141 Privoxy runs on has no direct Internet access.
2143 Note that parent proxies can severely decrease your privacy level. For example
2144 a parent proxy could add your IP address to the request headers and if it's a
2145 caching proxy it may add the "Etag" header to revalidation requests again, even
2146 though you configured Privoxy to remove it. It may also ignore Privoxy's header
2147 time randomization and use the original values which could be used by the
2148 server as cookie replacement to track your steps between visits.
2150 Also specified here are SOCKS proxies. Privoxy supports the SOCKS 4 and SOCKS
2153 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2159 To which parent HTTP proxy specific requests should be routed.
2163 target_pattern http_parent[:port]
2165 where target_pattern is a URL pattern that specifies to which requests
2166 (i.e. URLs) this forward rule shall apply. Use / to denote "all URLs".
2167 http_parent[:port] is the DNS name or IP address of the parent HTTP proxy
2168 through which the requests should be forwarded, optionally followed by its
2169 listening port (default: 8080). Use a single dot (.) to denote "no
2178 Don't use parent HTTP proxies.
2182 If http_parent is ".", then requests are not forwarded to another HTTP
2183 proxy but are made directly to the web servers.
2185 Multiple lines are OK, they are checked in sequence, and the last match
2190 Everything goes to an example parent proxy, except SSL on port 443 (which
2193 forward / parent-proxy.example.org:8080
2197 Everything goes to our example ISP's caching proxy, except for requests to
2200 forward / caching-proxy.isp.example.net:8000
2201 forward .isp.example.net .
2204 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2206 7.5.2. forward-socks4 and forward-socks4a
2210 Through which SOCKS proxy (and optionally to which parent HTTP proxy)
2211 specific requests should be routed.
2215 target_pattern socks_proxy[:port] http_parent[:port]
2217 where target_pattern is a URL pattern that specifies to which requests
2218 (i.e. URLs) this forward rule shall apply. Use / to denote "all URLs".
2219 http_parent and socks_proxy are IP addresses in dotted decimal notation or
2220 valid DNS names (http_parent may be "." to denote "no HTTP forwarding"),
2221 and the optional port parameters are TCP ports, i.e. integer values from 1
2230 Don't use SOCKS proxies.
2234 Multiple lines are OK, they are checked in sequence, and the last match
2237 The difference between forward-socks4 and forward-socks4a is that in the
2238 SOCKS 4A protocol, the DNS resolution of the target hostname happens on the
2239 SOCKS server, while in SOCKS 4 it happens locally.
2241 If http_parent is ".", then requests are not forwarded to another HTTP
2242 proxy but are made (HTTP-wise) directly to the web servers, albeit through
2247 From the company example.com, direct connections are made to all "internal"
2248 domains, but everything outbound goes through their ISP's proxy by way of
2249 example.com's corporate SOCKS 4A gateway to the Internet.
2251 forward-socks4a / socks-gw.example.com:1080 www-cache.isp.example.net:8080
2252 forward .example.com .
2255 A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent
2258 forward-socks4 / socks-gw.example.com:1080 .
2261 To chain Privoxy and Tor, both running on the same system, you would use
2264 forward-socks4a / 127.0.0.1:9050 .
2267 The public Tor network can't be used to reach your local network, if you
2268 need to access local servers you therefore might want to make some
2271 forward 192.168.*.*/ .
2273 forward 127.*.*.*/ .
2276 Unencrypted connections to systems in these address ranges will be as (un)
2277 secure as the local network is, but the alternative is that you can't reach
2278 the local network through Privoxy at all. Of course this may actually be
2279 desired and there is no reason to make these exceptions if you aren't sure
2282 If you also want to be able to reach servers in your local network by using
2283 their names, you will need additional exceptions that look like this:
2285 forward localhost/ .
2288 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2290 7.5.3. Advanced Forwarding Examples
2292 If you have links to multiple ISPs that provide various special content only to
2293 their subscribers, you can configure multiple Privoxies which have connections
2294 to the respective ISPs to act as forwarders to each other, so that your users
2295 can see the internal content of all ISPs.
2297 Assume that host-a has a PPP connection to isp-a.example.net. And host-b has a
2298 PPP connection to isp-b.example.org. Both run Privoxy. Their forwarding
2299 configuration can look like this:
2304 forward .isp-b.example.net host-b:8118
2310 forward .isp-a.example.org host-a:8118
2313 Now, your users can set their browser's proxy to use either host-a or host-b
2314 and be able to browse the internal content of both isp-a and isp-b.
2316 If you intend to chain Privoxy and squid locally, then chaining as browser ->
2317 squid -> privoxy is the recommended way.
2319 Assuming that Privoxy and squid run on the same box, your squid configuration
2320 could then look like this:
2322 # Define Privoxy as parent proxy (without ICP)
2323 cache_peer 127.0.0.1 parent 8118 7 no-query
2325 # Define ACL for protocol FTP
2328 # Do not forward FTP requests to Privoxy
2329 always_direct allow ftp
2331 # Forward all the rest to Privoxy
2332 never_direct allow all
2335 You would then need to change your browser's proxy settings to squid's address
2336 and port. Squid normally uses port 3128. If unsure consult http_port in
2339 You could just as well decide to only forward requests you suspect of leading
2340 to Windows executables through a virus-scanning parent proxy, say, on
2341 antivir.example.com, port 8010:
2344 forward /.*\.(exe|com|dll|zip)$ antivir.example.com:8010
2347 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2349 7.5.4. forwarded-connect-retries
2353 How often Privoxy retries if a forwarded connection request fails.
2365 Connections forwarded through other proxies are treated like direct
2366 connections and no retry attempts are made.
2370 forwarded-connect-retries is mainly interesting for socks4a connections,
2371 where Privoxy can't detect why the connections failed. The connection might
2372 have failed because of a DNS timeout in which case a retry makes sense, but
2373 it might also have failed because the server doesn't exist or isn't
2374 reachable. In this case the retry will just delay the appearance of
2375 Privoxy's error message.
2377 Note that in the context of this option, "forwarded connections" includes
2378 all connections that Privoxy forwards through other proxies. This option is
2379 not limited to the HTTP CONNECT method.
2381 Only use this option, if you are getting lots of forwarding-related error
2382 messages that go away when you try again manually. Start with a small value
2383 and check Privoxy's logfile from time to time, to see how many retries are
2388 forwarded-connect-retries 1
2390 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2392 7.5.5. accept-intercepted-requests
2396 Whether intercepted requests should be treated as valid.
2408 Only proxy requests are accepted, intercepted requests are treated as
2413 If you don't trust your clients and want to force them to use Privoxy,
2414 enable this option and configure your packet filter to redirect outgoing
2415 HTTP connections into Privoxy.
2417 Make sure that Privoxy's own requests aren't redirected as well.
2418 Additionally take care that Privoxy can't intentionally connect to itself,
2419 otherwise you could run into redirection loops if Privoxy's listening port
2420 is reachable by the outside or an attacker has access to the pages you
2425 accept-intercepted-requests 1
2427 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2429 7.5.6. allow-cgi-request-crunching
2433 Whether requests to Privoxy's CGI pages can be blocked or redirected.
2445 Privoxy ignores block and redirect actions for its CGI pages.
2449 By default Privoxy ignores block or redirect actions for its CGI pages.
2450 Intercepting these requests can be useful in multi-user setups to implement
2451 fine-grained access control, but it can also render the complete web
2452 interface useless and make debugging problems painful if done without care.
2454 Don't enable this option unless you're sure that you really need it.
2458 allow-cgi-request-crunching 1
2460 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2462 7.5.7. split-large-forms
2466 Whether the CGI interface should stay compatible with broken HTTP clients.
2478 The CGI form generate long GET URLs.
2482 Privoxy's CGI forms can lead to rather long URLs. This isn't a problem as
2483 far as the HTTP standard is concerned, but it can confuse clients with
2484 arbitrary URL length limitations.
2486 Enabling split-large-forms causes Privoxy to divide big forms into smaller
2487 ones to keep the URL length down. It makes editing a lot less convenient
2488 and you can no longer submit all changes at once, but at least it works
2489 around this browser bug.
2491 If you don't notice any editing problems, there is no reason to enable this
2492 option, but if one of the submit buttons appears to be broken, you should
2499 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2501 7.6. Windows GUI Options
2503 Privoxy has a number of options specific to the Windows GUI interface:
2505 If "activity-animation" is set to 1, the Privoxy icon will animate when
2506 "Privoxy" is active. To turn off, set to 0.
2508 activity-animation 1
2511 If "log-messages" is set to 1, Privoxy will log messages to the console window:
2516 If "log-buffer-size" is set to 1, the size of the log buffer, i.e. the amount
2517 of memory used for the log messages displayed in the console window, will be
2518 limited to "log-max-lines" (see below).
2520 Warning: Setting this to 0 will result in the buffer to grow infinitely and eat
2526 log-max-lines is the maximum number of lines held in the log buffer. See above.
2531 If "log-highlight-messages" is set to 1, Privoxy will highlight portions of the
2532 log messages with a bold-faced font:
2534 log-highlight-messages 1
2537 The font used in the console window:
2539 log-font-name Comic Sans MS
2542 Font size used in the console window:
2547 "show-on-task-bar" controls whether or not Privoxy will appear as a button on
2548 the Task bar when minimized:
2553 If "close-button-minimizes" is set to 1, the Windows close button will minimize
2554 Privoxy instead of closing the program (close with the exit option on the File
2557 close-button-minimizes 1
2560 The "hide-console" option is specific to the MS-Win console version of Privoxy.
2561 If this option is used, Privoxy will disconnect from and hide the command
2567 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2571 The actions files are used to define what actions Privoxy takes for which URLs,
2572 and thus determines how ad images, cookies and various other aspects of HTTP
2573 content and transactions are handled, and on which sites (or even parts
2574 thereof). There are a number of such actions, with a wide range of
2575 functionality. Each action does something a little different. These actions
2576 give us a veritable arsenal of tools with which to exert our control,
2577 preferences and independence. Actions can be combined so that their effects are
2578 aggregated when applied against a given set of URLs.
2580 There are three action files included with Privoxy with differing purposes:
2582 • default.action - is the primary action file that sets the initial values
2583 for all actions. It is intended to provide a base level of functionality
2584 for Privoxy's array of features. So it is a set of broad rules that should
2585 work reasonably well as-is for most users. This is the file that the
2586 developers are keeping updated, and making available to users. The user's
2587 preferences as set in standard.action, e.g. either Cautious (the default),
2588 Medium, or Advanced (see below).
2590 • user.action - is intended to be for local site preferences and exceptions.
2591 As an example, if your ISP or your bank has specific requirements, and need
2592 special handling, this kind of thing should go here. This file will not be
2595 • standard.action - is used only by the web based editor at http://
2596 config.privoxy.org/edit-actions-list?f=default, to set various pre-defined
2597 sets of rules for the default actions section in default.action.
2599 Edit Set to Cautious Set to Medium Set to Advanced
2601 These have increasing levels of aggressiveness and have no influence on
2602 your browsing unless you select them explicitly in the editor. A default
2603 installation should be pre-set to Cautious (versions prior to 3.0.5 were
2604 set to Medium). New users should try this for a while before adjusting the
2605 settings to more aggressive levels. The more aggressive the settings, then
2606 the more likelihood there is of problems such as sites not working as they
2609 The Edit button allows you to turn each action on/off individually for
2610 fine-tuning. The Cautious button changes the actions list to low/safe
2611 settings which will activate ad blocking and a minimal set of Privoxy's
2612 features, and subsequently there will be less of a chance for accidental
2613 problems. The Medium button sets the list to a medium level of other
2614 features and a low level set of privacy features. The Advanced button sets
2615 the list to a high level of ad blocking and medium level of privacy. See
2616 the chart below. The latter three buttons over-ride any changes via with
2617 the Edit button. More fine-tuning can be done in the lower sections of this
2620 It is not recommend to edit the standard.action file itself.
2622 The default profiles, and their associated actions, as pre-defined in
2623 standard.action are:
2625 Table 1. Default Configurations
2627 ┌──────────────────────────┬───────────┬────────────┬───────────┐
2628 │ Feature │ Cautious │ Medium │ Advanced │
2629 ├──────────────────────────┼───────────┼────────────┼───────────┤
2630 │Ad-blocking Aggressiveness│medium │high │high │
2631 ├──────────────────────────┼───────────┼────────────┼───────────┤
2632 │Ad-filtering by size │no │yes │yes │
2633 ├──────────────────────────┼───────────┼────────────┼───────────┤
2634 │Ad-filtering by link │no │no │yes │
2635 ├──────────────────────────┼───────────┼────────────┼───────────┤
2636 │Pop-up killing │blocks only│blocks only │blocks only│
2637 ├──────────────────────────┼───────────┼────────────┼───────────┤
2638 │Privacy Features │low │medium │medium/high│
2639 ├──────────────────────────┼───────────┼────────────┼───────────┤
2640 │Cookie handling │none │session-only│kill │
2641 ├──────────────────────────┼───────────┼────────────┼───────────┤
2642 │Referer forging │no │yes │yes │
2643 ├──────────────────────────┼───────────┼────────────┼───────────┤
2644 │GIF de-animation │no │yes │yes │
2645 ├──────────────────────────┼───────────┼────────────┼───────────┤
2646 │Fast redirects │no │no │yes │
2647 ├──────────────────────────┼───────────┼────────────┼───────────┤
2648 │HTML taming │no │no │yes │
2649 ├──────────────────────────┼───────────┼────────────┼───────────┤
2650 │JavaScript taming │no │no │yes │
2651 ├──────────────────────────┼───────────┼────────────┼───────────┤
2652 │Web-bug killing │no │yes │yes │
2653 ├──────────────────────────┼───────────┼────────────┼───────────┤
2654 │Image tag reordering │no │no │yes │
2655 └──────────────────────────┴───────────┴────────────┴───────────┘
2657 The list of actions files to be used are defined in the main configuration
2658 file, and are processed in the order they are defined (e.g. default.action is
2659 typically processed before user.action). The content of these can all be viewed
2660 and edited from http://config.privoxy.org/show-status. The over-riding
2661 principle when applying actions, is that the last action that matches a given
2662 URL wins. The broadest, most general rules go first (defined in
2663 default.action), followed by any exceptions (typically also in default.action),
2664 which are then followed lastly by any local preferences (typically in
2665 user.action). Generally, user.action has the last word.
2667 An actions file typically has multiple sections. If you want to use "aliases"
2668 in an actions file, you have to place the (optional) alias section at the top
2669 of that file. Then comes the default set of rules which will apply universally
2670 to all sites and pages (be very careful with using such a universal set in
2671 user.action or any other actions file after default.action, because it will
2672 override the result from consulting any previous file). And then below that,
2673 exceptions to the defined universal policies. You can regard user.action as an
2674 appendix to default.action, with the advantage that it is a separate file,
2675 which makes preserving your personal settings across Privoxy upgrades easier.
2677 Actions can be used to block anything you want, including ads, banners, or just
2678 some obnoxious URL whose content you would rather not see. Cookies can be
2679 accepted or rejected, or accepted only during the current browser session (i.e.
2680 not written to disk), content can be modified, some JavaScripts tamed,
2681 user-tracking fooled, and much more. See below for a complete list of actions.
2683 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2685 8.1. Finding the Right Mix
2687 Note that some actions, like cookie suppression or script disabling, may render
2688 some sites unusable that rely on these techniques to work properly. Finding the
2689 right mix of actions is not always easy and certainly a matter of personal
2690 taste. And, things can always change, requiring refinements in the
2691 configuration. In general, it can be said that the more "aggressive" your
2692 default settings (in the top section of the actions file) are, the more
2693 exceptions for "trusted" sites you will have to make later. If, for example,
2694 you want to crunch all cookies per default, you'll have to make exceptions from
2695 that rule for sites that you regularly use and that require cookies for
2696 actually useful purposes, like maybe your bank, favorite shop, or newspaper.
2698 We have tried to provide you with reasonable rules to start from in the
2699 distribution actions files. But there is no general rule of thumb on these
2700 things. There just are too many variables, and sites are constantly changing.
2701 Sooner or later you will want to change the rules (and read this chapter again
2704 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2708 The easiest way to edit the actions files is with a browser by using our
2709 browser-based editor, which can be reached from http://config.privoxy.org/
2710 show-status. Note: the config file option enable-edit-actions must be enabled
2711 for this to work. The editor allows both fine-grained control over every single
2712 feature on a per-URL basis, and easy choosing from wholesale sets of defaults
2713 like "Cautious", "Medium" or "Advanced". Warning: the "Advanced" setting is
2714 more aggressive, and will be more likely to cause problems for some sites.
2715 Experienced users only!
2717 If you prefer plain text editing to GUIs, you can of course also directly edit
2718 the the actions files with your favorite text editor. Look at default.action
2719 which is richly commented with many good examples.
2721 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2723 8.3. How Actions are Applied to Requests
2725 Actions files are divided into sections. There are special sections, like the "
2726 alias" sections which will be discussed later. For now let's concentrate on
2727 regular sections: They have a heading line (often split up to multiple lines
2728 for readability) which consist of a list of actions, separated by whitespace
2729 and enclosed in curly braces. Below that, there is a list of URL and tag
2730 patterns, each on a separate line.
2732 To determine which actions apply to a request, the URL of the request is
2733 compared to all URL patterns in each "action file". Every time it matches, the
2734 list of applicable actions for the request is incrementally updated, using the
2735 heading of the section in which the pattern is located. The same is done again
2736 for tags and tag patterns later on.
2738 If multiple applying sections set the same action differently, the last match
2739 wins. If not, the effects are aggregated. E.g. a URL might match a regular
2740 section with a heading line of { +handle-as-image }, then later another one
2741 with just { +block }, resulting in both actions to apply. And there may well be
2742 cases where you will want to combine actions together. Such a section then
2745 { +handle-as-image +block }
2746 # Block these as if they were images. Send no block page.
2748 media.example.com/.*banners
2749 .example.com/images/ads/
2752 You can trace this process for URL patterns and any given URL by visiting http:
2753 //config.privoxy.org/show-url-info.
2755 Examples and more detail on this is provided in the Appendix, Troubleshooting:
2756 Anatomy of an Action section.
2758 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2762 As mentioned, Privoxy uses "patterns" to determine what actions might apply to
2763 which sites and pages your browser attempts to access. These "patterns" use
2764 wild card type pattern matching to achieve a high degree of flexibility. This
2765 allows one expression to be expanded and potentially match against many similar
2768 Generally, an URL pattern has the form <domain>/<path>, where both the <domain>
2769 and <path> are optional. (This is why the special / pattern matches all URLs).
2770 Note that the protocol portion of the URL pattern (e.g. http://) should not be
2771 included in the pattern. This is assumed already!
2773 The pattern matching syntax is different for the domain and path parts of the
2774 URL. The domain part uses a simple globbing type matching technique, while the
2775 path part uses a more flexible "Regular Expressions (PCRE)" based syntax.
2779 is a domain-only pattern and will match any request to www.example.com,
2780 regardless of which document on that server is requested. So ALL pages in
2781 this domain would be covered by the scope of this action. Note that a
2782 simple example.com is different and would NOT match.
2786 means exactly the same. For domain-only patterns, the trailing / may be
2789 www.example.com/index.html$
2791 matches all the documents on www.example.com whose name starts with /
2794 www.example.com/index.html$
2796 matches only the single document /index.html on www.example.com.
2800 matches the document /index.html, regardless of the domain, i.e. on any web
2805 matches nothing, since it would be interpreted as a domain name and there
2806 is no top-level domain called .html. So its a mistake.
2808 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2810 8.4.1. The Domain Pattern
2812 The matching of the domain part offers some flexible options: if the domain
2813 starts or ends with a dot, it becomes unanchored at that end. For example:
2817 matches any domain that ENDS in .example.com
2821 matches any domain that STARTS with www.
2825 matches any domain that CONTAINS .example.. And, by the way, also included
2826 would be any files or documents that exist within that domain since no path
2827 limitations are specified. (Correctly speaking: It matches any FQDN that
2828 contains example as a domain.) This might be www.example.com,
2829 news.example.de, or www.example.net/cgi/testing.pl for instance. All these
2832 Additionally, there are wild-cards that you can use in the domain names
2833 themselves. These work similarly to shell globbing type wild-cards: "*"
2834 represents zero or more arbitrary characters (this is equivalent to the
2835 "Regular Expression" based syntax of ".*"), "?" represents any single character
2836 (this is equivalent to the regular expression syntax of a simple "."), and you
2837 can define "character classes" in square brackets which is similar to the same
2838 regular expression technique. All of this can be freely mixed:
2842 matches "adserver.example.com", "ads.example.com", etc but not
2847 matches all of the above, and then some.
2851 matches www.ipix.com, pictures.epix.com, a.b.c.d.e.upix.com etc.
2853 www[1-9a-ez].example.c*
2855 matches www1.example.com, www4.example.cc, wwwd.example.cy,
2856 wwwz.example.com etc., but not wwww.example.com.
2858 While flexible, this is not the sophistication of full regular expression based
2861 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2863 8.4.2. The Path Pattern
2865 Privoxy uses Perl compatible (PCRE) "Regular Expression" based syntax (through
2866 the PCRE library) for matching the path portion (after the slash), and is thus
2869 There is an Appendix with a brief quick-start into regular expressions, and
2870 full (very technical) documentation on PCRE regex syntax is available on-line
2871 at http://www.pcre.org/man.txt. You might also find the Perl man page on
2872 regular expressions (man perlre) useful, which is available on-line at http://
2873 perldoc.perl.org/perlre.html.
2875 Note that the path pattern is automatically left-anchored at the "/", i.e. it
2876 matches as if it would start with a "^" (regular expression speak for the
2877 beginning of a line).
2879 Please also note that matching in the path is CASE INSENSITIVE by default, but
2880 you can switch to case sensitive at any point in the pattern by using the "(?
2881 -i)" switch: www.example.com/(?-i)PaTtErN.* will match only documents whose
2882 path starts with PaTtErN in exactly this capitalization.
2886 Is equivalent to just ".example.com", since any documents within that
2887 domain are matched with or without the ".*" regular expression. This is
2890 .example.com/.*/index.html$
2892 Will match any page in the domain of "example.com" that is named
2893 "index.html", and that is part of some path. For example, it matches
2894 "www.example.com/testing/index.html" but NOT "www.example.com/index.html"
2895 because the regular expression called for at least two "/'s", thus the path
2896 requirement. It also would match "www.example.com/testing/index_html",
2897 because of the special meta-character ".".
2899 .example.com/(.*/)?index\.html$
2901 This regular expression is conditional so it will match any page named
2902 "index.html" regardless of path which in this case can have one or more "/
2903 's". And this one must contain exactly ".html" (but does not have to end
2906 .example.com/(.*/)(ads|banners?|junk)
2908 This regular expression will match any path of "example.com" that contains
2909 any of the words "ads", "banner", "banners" (because of the "?") or "junk".
2910 The path does not have to end in these words, just contain them.
2912 .example.com/(.*/)(ads|banners?|junk)/.*\.(jpe?g|gif|png)$
2914 This is very much the same as above, except now it must end in either
2915 ".jpg", ".jpeg", ".gif" or ".png". So this one is limited to common image
2918 There are many, many good examples to be found in default.action, and more
2919 tutorials below in Appendix on regular expressions.
2921 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2923 8.4.3. The Tag Pattern
2925 Tag patterns are used to change the applying actions based on the request's
2926 tags. Tags can be created with either the client-header-tagger or the
2927 server-header-tagger action.
2929 Tag patterns have to start with "TAG:", so Privoxy can tell them apart from URL
2930 patterns. Everything after the colon including white space, is interpreted as a
2931 regular expression with path pattern syntax, except that tag patterns aren't
2932 left-anchored automatically (Privoxy doesn't silently add a "^", you have to do
2933 it yourself if you need it).
2935 To match all requests that are tagged with "foo" your pattern line should be
2936 "TAG:^foo$", "TAG:foo" would work as well, but it would also match requests
2937 whose tags contain "foo" somewhere. "TAG: foo" wouldn't work as it requires
2940 Sections can contain URL and tag patterns at the same time, but tag patterns
2941 are checked after the URL patterns and thus always overrule them, even if they
2942 are located before the URL patterns.
2944 Once a new tag is added, Privoxy checks right away if it's matched by one of
2945 the tag patterns and updates the action settings accordingly. As a result tags
2946 can be used to activate other tagger actions, as long as these other taggers
2947 look for headers that haven't already be parsed.
2949 For example you could tag client requests which use the POST method, then use
2950 this tag to activate another tagger that adds a tag if cookies are sent, and
2951 then use a block action based on the cookie tag. This allows the outcome of one
2952 action, to be input into a subsequent action. However if you'd reverse the
2953 position of the described taggers, and activated the method tagger based on the
2954 cookie tagger, no method tags would be created. The method tagger would look
2955 for the request line, but at the time the cookie tag is created, the request
2956 line has already been parsed.
2958 While this is a limitation you should be aware of, this kind of indirection is
2959 seldom needed anyway and even the example doesn't make too much sense.
2961 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
2965 All actions are disabled by default, until they are explicitly enabled
2966 somewhere in an actions file. Actions are turned on if preceded with a "+", and
2967 turned off if preceded with a "-". So a +action means "do that action", e.g.
2968 +block means "please block URLs that match the following patterns", and -block
2969 means "don't block URLs that match the following patterns, even if +block
2970 previously applied."
2972 Again, actions are invoked by placing them on a line, enclosed in curly braces
2973 and separated by whitespace, like in {+some-action -some-other-action
2974 {some-parameter}}, followed by a list of URL patterns, one per line, to which
2975 they apply. Together, the actions line and the following pattern lines make up
2976 a section of the actions file.
2978 Actions fall into three categories:
2980 • Boolean, i.e the action can only be "enabled" or "disabled". Syntax:
2982 +name # enable action name
2983 -name # disable action name
2988 • Parameterized, where some value is required in order to enable this type of
2991 +name{param} # enable action and set parameter to param,
2992 # overwriting parameter from previous match if necessary
2993 -name # disable action. The parameter can be omitted
2996 Note that if the URL matches multiple positive forms of a parameterized
2997 action, the last match wins, i.e. the params from earlier matches are
3000 Example: +hide-user-agent{Mozilla/5.0 (X11; U; FreeBSD i386; en-US;
3001 rv:1.8.1.4) Gecko/20070602 Firefox/2.0.0.4}
3003 • Multi-value. These look exactly like parameterized actions, but they behave
3004 differently: If the action applies multiple times to the same URL, but with
3005 different parameters, all the parameters from all matches are remembered.
3006 This is used for actions that can be executed for the same request
3007 repeatedly, like adding multiple headers, or filtering through multiple
3010 +name{param} # enable action and add param to the list of parameters
3011 -name{param} # remove the parameter param from the list of parameters
3012 # If it was the last one left, disable the action.
3013 -name # disable this action completely and remove all parameters from the list
3016 Examples: +add-header{X-Fun-Header: Some text} and +filter{html-annoyances}
3018 If nothing is specified in any actions file, no "actions" are taken. So in this
3019 case Privoxy would just be a normal, non-blocking, non-filtering proxy. You
3020 must specifically enable the privacy and blocking features you need (although
3021 the provided default actions files will give a good starting point).
3023 Later defined action sections always over-ride earlier ones of the same type.
3024 So exceptions to any rules you make, should come in the latter part of the file
3025 (or in a file that is processed later when using multiple actions files such as
3026 user.action). For multi-valued actions, the actions are applied in the order
3027 they are specified. Actions files are processed in the order they are defined
3028 in config (the default installation has three actions files). It also quite
3029 possible for any given URL to match more than one "pattern" (because of
3030 wildcards and regular expressions), and thus to trigger more than one set of
3031 actions! Last match wins.
3033 The list of valid Privoxy actions are:
3035 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3041 Confuse log analysis, custom applications
3045 Sends a user defined HTTP header to the web server.
3053 Any string value is possible. Validity of the defined HTTP headers is not
3054 checked. It is recommended that you use the "X-" prefix for custom headers.
3058 This action may be specified multiple times, in order to define multiple
3059 headers. This is rarely needed for the typical user. If you don't know what
3060 "HTTP headers" are, you definitely don't need to worry about this one.
3064 +add-header{X-User-Tracking: sucks}
3067 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3073 Block ads or other unwanted content
3077 Requests for URLs to which this action applies are blocked, i.e. the
3078 requests are trapped by Privoxy and the requested URL is never retrieved,
3079 but is answered locally with a substitute page or image, as determined by
3080 the handle-as-image, set-image-blocker, and handle-as-empty-document
3093 Privoxy sends a special "BLOCKED" page for requests to blocked pages. This
3094 page contains links to find out why the request was blocked, and a
3095 click-through to the blocked content (the latter only if compiled with the
3096 force feature enabled). The "BLOCKED" page adapts to the available screen
3097 space -- it displays full-blown if space allows, or miniaturized and
3098 text-only if loaded into a small frame or window. If you are using Privoxy
3099 right now, you can take a look at the "BLOCKED" page.
3101 A very important exception occurs if both block and handle-as-image, apply
3102 to the same request: it will then be replaced by an image. If
3103 set-image-blocker (see below) also applies, the type of image will be
3104 determined by its parameter, if not, the standard checkerboard pattern is
3107 It is important to understand this process, in order to understand how
3108 Privoxy deals with ads and other unwanted content. Blocking is a core
3109 feature, and one upon which various other features depend.
3111 The filter action can perform a very similar task, by "blocking" banner
3112 images and other content through rewriting the relevant URLs in the
3113 document's HTML source, so they don't get requested in the first place.
3114 Note that this is a totally different technique, and it's easy to confuse
3117 Example usage (section):
3120 # Block and replace with "blocked" page
3121 .nasty-stuff.example.com
3123 {+block +handle-as-image}
3124 # Block and replace with image
3128 {+block +handle-as-empty-document}
3129 # Block and then ignore
3130 adserver.exampleclick.net/.*\.js$
3133 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3135 8.5.3. client-header-filter
3139 Rewrite or remove single client headers.
3143 All client headers to which this action applies are filtered on-the-fly
3144 through the specified regular expression based substitutions.
3152 The name of a client-header filter, as defined in one of the filter files.
3156 Client-header filters are applied to each header on its own, not to all at
3157 once. This makes it easier to diagnose problems, but on the downside you
3158 can't write filters that only change header x if header y's value is z. You
3159 can do that by using tags though.
3161 Client-header filters are executed after the other header actions have
3162 finished and use their output as input.
3164 Please refer to the filter file chapter to learn which client-header
3165 filters are available by default, and how to create your own.
3167 Example usage (section):
3169 {+client-header-filter{hide-tor-exit-notation}}
3174 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3176 8.5.4. client-header-tagger
3180 Block requests based on their headers.
3184 Client headers to which this action applies are filtered on-the-fly through
3185 the specified regular expression based substitutions, the result is used as
3194 The name of a client-header tagger, as defined in one of the filter files.
3198 Client-header taggers are applied to each header on its own, and as the
3199 header isn't modified, each tagger "sees" the original.
3201 Client-header taggers are the first actions that are executed and their
3202 tags can be used to control every other action.
3204 Example usage (section):
3206 # Tag every request with the User-Agent header
3207 {+client-header-tagger{user-agent}}
3212 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3214 8.5.5. content-type-overwrite
3218 Stop useless download menus from popping up, or change the browser's
3223 Replaces the "Content-Type:" HTTP server header.
3235 The "Content-Type:" HTTP server header is used by the browser to decide
3236 what to do with the document. The value of this header can cause the
3237 browser to open a download menu instead of displaying the document by
3238 itself, even if the document's format is supported by the browser.
3240 The declared content type can also affect which rendering mode the browser
3241 chooses. If XHTML is delivered as "text/html", many browsers treat it as
3242 yet another broken HTML document. If it is send as "application/xml",
3243 browsers with XHTML support will only display it, if the syntax is correct.
3245 If you see a web site that proudly uses XHTML buttons, but sets
3246 "Content-Type: text/html", you can use Privoxy to overwrite it with
3247 "application/xml" and validate the web master's claim inside your
3248 XHTML-supporting browser. If the syntax is incorrect, the browser will
3251 You can also go the opposite direction: if your browser prints error
3252 messages instead of rendering a document falsely declared as XHTML, you can
3253 overwrite the content type with "text/html" and have it rendered as broken
3256 By default content-type-overwrite only replaces "Content-Type:" headers
3257 that look like some kind of text. If you want to overwrite it
3258 unconditionally, you have to combine it with force-text-mode. This
3259 limitation exists for a reason, think twice before circumventing it.
3261 Most of the time it's easier to replace this action with a custom
3262 server-header filter. It allows you to activate it for every document of a
3263 certain site and it will still only replace the content types you aimed at.
3265 Of course you can apply content-type-overwrite to a whole site and then
3266 make URL based exceptions, but it's a lot more work to get the same
3269 Example usage (sections):
3271 # Check if www.example.net/ really uses valid XHTML
3272 { +content-type-overwrite{application/xml} }
3275 # but leave the content type unmodified if the URL looks like a style sheet
3276 {-content-type-overwrite}
3277 www.example.net/.*\.css$
3278 www.example.net/.*style
3281 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3283 8.5.6. crunch-client-header
3287 Remove a client header Privoxy has no dedicated action for.
3291 Deletes every header sent by the client that contains the string the user
3292 supplied as parameter.
3304 This action allows you to block client headers for which no dedicated
3305 Privoxy action exists. Privoxy will remove every client header that
3306 contains the string you supplied as parameter.
3308 Regular expressions are not supported and you can't use this action to
3309 block different headers in the same request, unless they contain the same
3312 crunch-client-header is only meant for quick tests. If you have to block
3313 several different headers, or only want to modify parts of them, you should
3314 use a client-header filter.
3316 ┌─────────────────────────────────────────────────────────────────┐
3318 ├─────────────────────────────────────────────────────────────────┤
3319 │Don't block any header without understanding the consequences. │
3320 └─────────────────────────────────────────────────────────────────┘
3321 Example usage (section):
3323 # Block the non-existent "Privacy-Violation:" client header
3324 { +crunch-client-header{Privacy-Violation:} }
3329 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3331 8.5.7. crunch-if-none-match
3335 Prevent yet another way to track the user's steps between sessions.
3339 Deletes the "If-None-Match:" HTTP client header.
3351 Removing the "If-None-Match:" HTTP client header is useful for filter
3352 testing, where you want to force a real reload instead of getting status
3353 code "304" which would cause the browser to use a cached copy of the page.
3355 It is also useful to make sure the header isn't used as a cookie
3356 replacement (unlikely but possible).
3358 Blocking the "If-None-Match:" header shouldn't cause any caching problems,
3359 as long as the "If-Modified-Since:" header isn't blocked or missing as
3362 It is recommended to use this action together with hide-if-modified-since
3363 and overwrite-last-modified.
3365 Example usage (section):
3367 # Let the browser revalidate cached documents but don't
3368 # allow the server to use the revalidation headers for user tracking.
3369 {+hide-if-modified-since{-60} \
3370 +overwrite-last-modified{randomize} \
3371 +crunch-if-none-match}
3375 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3377 8.5.8. crunch-incoming-cookies
3381 Prevent the web server from setting HTTP cookies on your system
3385 Deletes any "Set-Cookie:" HTTP headers from server replies.
3397 This action is only concerned with incoming HTTP cookies. For outgoing HTTP
3398 cookies, use crunch-outgoing-cookies. Use both to disable HTTP cookies
3401 It makes no sense at all to use this action in conjunction with the
3402 session-cookies-only action, since it would prevent the session cookies
3403 from being set. See also filter-content-cookies.
3407 +crunch-incoming-cookies
3410 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3412 8.5.9. crunch-server-header
3416 Remove a server header Privoxy has no dedicated action for.
3420 Deletes every header sent by the server that contains the string the user
3421 supplied as parameter.
3433 This action allows you to block server headers for which no dedicated
3434 Privoxy action exists. Privoxy will remove every server header that
3435 contains the string you supplied as parameter.
3437 Regular expressions are not supported and you can't use this action to
3438 block different headers in the same request, unless they contain the same
3441 crunch-server-header is only meant for quick tests. If you have to block
3442 several different headers, or only want to modify parts of them, you should
3443 use a custom server-header filter.
3445 ┌─────────────────────────────────────────────────────────────────┐
3447 ├─────────────────────────────────────────────────────────────────┤
3448 │Don't block any header without understanding the consequences. │
3449 └─────────────────────────────────────────────────────────────────┘
3450 Example usage (section):
3452 # Crunch server headers that try to prevent caching
3453 { +crunch-server-header{no-cache} }
3457 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3459 8.5.10. crunch-outgoing-cookies
3463 Prevent the web server from reading any HTTP cookies from your system
3467 Deletes any "Cookie:" HTTP headers from client requests.
3479 This action is only concerned with outgoing HTTP cookies. For incoming HTTP
3480 cookies, use crunch-incoming-cookies. Use both to disable HTTP cookies
3483 It makes no sense at all to use this action in conjunction with the
3484 session-cookies-only action, since it would prevent the session cookies
3489 +crunch-outgoing-cookies
3492 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3494 8.5.11. deanimate-gifs
3498 Stop those annoying, distracting animated GIF images.
3502 De-animate GIF animations, i.e. reduce them to their first or last image.
3514 This will also shrink the images considerably (in bytes, not pixels!). If
3515 the option "first" is given, the first frame of the animation is used as
3516 the replacement. If "last" is given, the last frame of the animation is
3517 used instead, which probably makes more sense for most banner animations,
3518 but also has the risk of not showing the entire last frame (if it is only a
3519 delta to an earlier frame).
3521 You can safely use this action with patterns that will also match non-GIF
3522 objects, because no attempt will be made at anything that doesn't look like
3527 +deanimate-gifs{last}
3530 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3532 8.5.12. downgrade-http-version
3536 Work around (very rare) problems with HTTP/1.1
3540 Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0.
3552 This is a left-over from the time when Privoxy didn't support important
3553 HTTP/1.1 features well. It is left here for the unlikely case that you
3554 experience HTTP/1.1 related problems with some server out there. Not all
3555 HTTP/1.1 features and requirements are supported yet, so there is a chance
3556 you might need this action.
3558 Example usage (section):
3560 {+downgrade-http-version}
3561 problem-host.example.com
3564 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3566 8.5.13. fast-redirects
3570 Fool some click-tracking scripts and speed up indirect links.
3574 Detects redirection URLs and redirects the browser without contacting the
3575 redirection server first.
3583 □ "simple-check" to just search for the string "http://" to detect
3586 □ "check-decoded-url" to decode URLs (if necessary) before searching for
3591 Many sites, like yahoo.com, don't just link to other sites. Instead, they
3592 will link to some script on their own servers, giving the destination as a
3593 parameter, which will then redirect you to the final target. URLs resulting
3594 from this scheme typically look like: "http://www.example.org/
3595 click-tracker.cgi?target=http%3a//www.example.net/".
3597 Sometimes, there are even multiple consecutive redirects encoded in the
3598 URL. These redirections via scripts make your web browsing more traceable,
3599 since the server from which you follow such a link can see where you go to.
3600 Apart from that, valuable bandwidth and time is wasted, while your browser
3601 asks the server for one redirect after the other. Plus, it feeds the
3604 This feature is currently not very smart and is scheduled for improvement.
3605 If it is enabled by default, you will have to create some exceptions to
3606 this action. It can lead to failures in several ways:
3608 Not every URLs with other URLs as parameters is evil. Some sites offer a
3609 real service that requires this information to work. For example a
3610 validation service needs to know, which document to validate.
3611 fast-redirects assumes that every URL parameter that looks like another URL
3612 is a redirection target, and will always redirect to the last one. Most of
3613 the time the assumption is correct, but if it isn't, the user gets
3616 Another failure occurs if the URL contains other parameters after the URL
3617 parameter. The URL: "http://www.example.org/?redirect=http%3a//
3618 www.example.net/&foo=bar". contains the redirection URL "http://
3619 www.example.net/", followed by another parameter. fast-redirects doesn't
3620 know that and will cause a redirect to "http://www.example.net/&foo=bar".
3621 Depending on the target server configuration, the parameter will be
3622 silently ignored or lead to a "page not found" error. You can prevent this
3623 problem by first using the redirect action to remove the last part of the
3624 URL, but it requires a little effort.
3626 To detect a redirection URL, fast-redirects only looks for the string
3627 "http://", either in plain text (invalid but often used) or encoded as
3628 "http%3a//". Some sites use their own URL encoding scheme, encrypt the
3629 address of the target server or replace it with a database id. In theses
3630 cases fast-redirects is fooled and the request reaches the redirection
3631 server where it probably gets logged.
3635 { +fast-redirects{simple-check} }
3638 { +fast-redirects{check-decoded-url} }
3639 another.example.com/testing
3642 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3648 Get rid of HTML and JavaScript annoyances, banner advertisements (by size),
3649 do fun text replacements, add personalized effects, etc.
3653 All instances of text-based type, most notably HTML and JavaScript, to
3654 which this action applies, can be filtered on-the-fly through the specified
3655 regular expression based substitutions. (Note: as of version 3.0.3 plain
3656 text documents are exempted from filtering, because web servers often use
3657 the text/plain MIME type for all files whose type they don't know.)
3665 The name of a content filter, as defined in the filter file. Filters can be
3666 defined in one or more files as defined by the filterfile option in the
3667 config file. default.filter is the collection of filters supplied by the
3668 developers. Locally defined filters should go in their own file, such as
3671 When used in its negative form, and without parameters, all filtering is
3672 completely disabled.
3676 For your convenience, there are a number of pre-defined filters available
3677 in the distribution filter file that you can use. See the examples below
3680 Filtering requires buffering the page content, which may appear to slow
3681 down page rendering since nothing is displayed until all content has passed
3682 the filters. (It does not really take longer, but seems that way since the
3683 page is not incrementally displayed.) This effect will be more noticeable
3684 on slower connections.
3686 "Rolling your own" filters requires a knowledge of "Regular Expressions"
3687 and "HTML". This is very powerful feature, and potentially very intrusive.
3688 Filters should be used with caution, and where an equivalent "action" is
3691 The amount of data that can be filtered is limited to the buffer-limit
3692 option in the main config file. The default is 4096 KB (4 Megs). Once this
3693 limit is exceeded, the buffered data, and all pending data, is passed
3696 Inappropriate MIME types, such as zipped files, are not filtered at all.
3697 (Again, only text-based types except plain text). Encrypted SSL data (from
3698 HTTPS servers) cannot be filtered either, since this would violate the
3699 integrity of the secure transaction. In some situations it might be
3700 necessary to protect certain text, like source code, from filtering by
3701 defining appropriate -filter exceptions.
3703 Compressed content can't be filtered either, unless Privoxy is compiled
3704 with zlib support (requires at least Privoxy 3.0.7), in which case Privoxy
3705 will decompress the content before filtering it.
3707 If you use a Privoxy version without zlib support, but want filtering to
3708 work on as much documents as possible, even those that would normally be
3709 sent compressed, you must use the prevent-compression action in conjunction
3712 Content filtering can achieve some of the same effects as the block action,
3713 i.e. it can be used to block ads and banners. But the mechanism works quite
3714 differently. One effective use, is to block ad banners based on their size
3715 (see below), since many of these seem to be somewhat standardized.
3717 Feedback with suggestions for new or improved filters is particularly
3720 The below list has only the names and a one-line description of each
3721 predefined filter. There are more verbose explanations of what these
3722 filters do in the filter file chapter.
3724 Example usage (with filters from the distribution default.filter file). See the
3725 Predefined Filters section for more explanation on each:
3727 +filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse
3730 +filter{js-events} # Kill all JS event bindings (Radically destructive! Only for extra nasty sites)
3733 +filter{html-annoyances} # Get rid of particularly annoying HTML abuse
3736 +filter{content-cookies} # Kill cookies that come in the HTML or JS content
3739 +filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups)
3742 +filter{unsolicited-popups} # Disable only unsolicited pop-up windows. Useful if your browser lacks this ability.
3745 +filter{all-popups} # Kill all popups in JavaScript and HTML. Useful if your browser lacks this ability.
3748 +filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective
3751 +filter{banners-by-size} # Kill banners by size
3754 +filter{banners-by-link} # Kill banners by their links to known clicktrackers
3757 +filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking)
3760 +filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap
3763 +filter{jumping-windows} # Prevent windows from resizing and moving themselves
3766 +filter{frameset-borders} # Give frames a border and make them resizeable
3769 +filter{demoronizer} # Fix MS's non-standard use of standard charsets
3772 +filter{shockwave-flash} # Kill embedded Shockwave Flash objects
3775 +filter{quicktime-kioskmode} # Make Quicktime movies savable
3778 +filter{fun} # Text replacements for subversive browsing fun!
3781 +filter{crude-parental} # Crude parental filtering (demo only)
3784 +filter{ie-exploits} # Disable a known Internet Explorer bug exploits
3787 +filter{site-specifics} # Custom filters for specific site related problems
3790 +filter{google} # Removes text ads and other Google specific improvements
3793 +filter{yahoo} # Removes text ads and other Yahoo specific improvements
3796 +filter{msn} # Removes text ads and other MSN specific improvements
3799 +filter{blogspot} # Cleans up Blogspot blogs
3802 +filter{no-ping} # Removes non-standard ping attributes from anchor and area tags
3805 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3807 8.5.15. force-text-mode
3811 Force Privoxy to treat a document as if it was in some kind of text format.
3815 Declares a document as text, even if the "Content-Type:" isn't detected as
3828 As explained above, Privoxy tries to only filter files that are in some
3829 kind of text format. The same restrictions apply to content-type-overwrite.
3830 force-text-mode declares a document as text, without looking at the
3831 "Content-Type:" first.
3833 ┌─────────────────────────────────────────────────────────────────┐
3835 ├─────────────────────────────────────────────────────────────────┤
3836 │Think twice before activating this action. Filtering binary data │
3837 │with regular expressions can cause file damage. │
3838 └─────────────────────────────────────────────────────────────────┘
3845 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3847 8.5.16. forward-override
3851 Change the forwarding settings based on User-Agent or request origin
3855 Overrules the forward directives in the configuration file.
3863 □ "forward ." to use a direct connection without any additional proxies.
3865 □ "forward 127.0.0.1:8123" to use the HTTP proxy listening at 127.0.0.1
3868 □ "forward-socks4a 127.0.0.1:9050 ." to use the socks4a proxy listening
3869 at 127.0.0.1 port 9050. Replace "forward-socks4a" with "forward-socks4"
3870 to use a socks4 connection (with local DNS resolution) instead.
3872 □ "forward-socks4a 127.0.0.1:9050 proxy.example.org:8000" to use the
3873 socks4a proxy listening at 127.0.0.1 port 9050 to reach the HTTP proxy
3874 listening at proxy.example.org port 8000. Replace "forward-socks4a"
3875 with "forward-socks4" to use a socks4 connection (with local DNS
3876 resolution) instead.
3880 This action takes parameters similar to the forward directives in the
3881 configuration file, but without the URL pattern. It can be used as
3882 replacement, but normally it's only used in cases where matching based on
3883 the request URL isn't sufficient.
3885 ┌─────────────────────────────────────────────────────────────────┐
3887 ├─────────────────────────────────────────────────────────────────┤
3888 │Please read the description for the forward directives before │
3889 │using this action. Forwarding to the wrong people will reduce │
3890 │your privacy and increase the chances of man-in-the-middle │
3893 │If the ports are missing or invalid, default values will be used.│
3894 │This might change in the future and you shouldn't rely on it. │
3895 │Otherwise incorrect syntax causes Privoxy to exit. │
3897 │Use the show-url-info CGI page to verify that your forward │
3898 │settings do what you thought the do. │
3899 └─────────────────────────────────────────────────────────────────┘
3902 # Always use direct connections for requests previously tagged as
3903 # "User-Agent: fetch libfetch/2.0" and make sure
3904 # resuming downloads continues to work.
3905 # This way you can continue to use Tor for your normal browsing,
3906 # without overloading the Tor network with your FreeBSD ports updates
3907 # or downloads of bigger files like ISOs.
3908 {+forward-override{forward .} \
3909 -hide-if-modified-since \
3910 -overwrite-last-modified \
3912 TAG:^User-Agent: fetch libfetch/2\.0$
3916 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3918 8.5.17. handle-as-empty-document
3922 Mark URLs that should be replaced by empty documents if they get blocked
3926 This action alone doesn't do anything noticeable. It just marks URLs. If
3927 the block action also applies, the presence or absence of this mark decides
3928 whether an HTML "BLOCKED" page, or an empty document will be sent to the
3929 client as a substitute for the blocked content. The empty document isn't
3930 literally empty, but actually contains a single space.
3942 Some browsers complain about syntax errors if JavaScript documents are
3943 blocked with Privoxy's default HTML page; this option can be used to
3944 silence them. And of course this action can also be used to eliminate the
3945 Privoxy BLOCKED message in frames.
3947 The content type for the empty document can be specified with
3948 content-type-overwrite{}, but usually this isn't necessary.
3952 # Block all documents on example.org that end with ".js",
3953 # but send an empty document instead of the usual HTML message.
3954 {+block +handle-as-empty-document}
3959 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
3961 8.5.18. handle-as-image
3965 Mark URLs as belonging to images (so they'll be replaced by images if they
3966 do get blocked, rather than HTML pages)
3970 This action alone doesn't do anything noticeable. It just marks URLs as
3971 images. If the block action also applies, the presence or absence of this
3972 mark decides whether an HTML "blocked" page, or a replacement image (as
3973 determined by the set-image-blocker action) will be sent to the client as a
3974 substitute for the blocked content.
3986 The below generic example section is actually part of default.action. It
3987 marks all URLs with well-known image file name extensions as images and
3988 should be left intact.
3990 Users will probably only want to use the handle-as-image action in
3991 conjunction with block, to block sources of banners, whose URLs don't
3992 reflect the file type, like in the second example section.
3994 Note that you cannot treat HTML pages as images in most cases. For
3995 instance, (in-line) ad frames require an HTML page to be sent, or they
3996 won't display properly. Forcing handle-as-image in this situation will not
3997 replace the ad frame with an image, but lead to error messages.
3999 Example usage (sections):
4001 # Generic image extensions:
4004 /.*\.(gif|jpg|jpeg|png|bmp|ico)$
4006 # These don't look like images, but they're banners and should be
4007 # blocked as images:
4009 {+block +handle-as-image}
4010 some.nasty-banner-server.com/junk.cgi\?output=trash
4012 # Banner source! Who cares if they also have non-image content?
4016 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4018 8.5.19. hide-accept-language
4022 Pretend to use different language settings.
4026 Deletes or replaces the "Accept-Language:" HTTP header in client requests.
4034 Keyword: "block", or any user defined value.
4038 Faking the browser's language settings can be useful to make a foreign
4039 User-Agent set with hide-user-agent more believable.
4041 However some sites with content in different languages check the
4042 "Accept-Language:" to decide which one to take by default. Sometimes it
4043 isn't possible to later switch to another language without changing the
4044 "Accept-Language:" header first.
4046 Therefore it's a good idea to either only change the "Accept-Language:"
4047 header to languages you understand, or to languages that aren't wide
4050 Before setting the "Accept-Language:" header to a rare language, you should
4051 consider that it helps to make your requests unique and thus easier to
4052 trace. If you don't plan to change this header frequently, you should stick
4053 to a common language.
4055 Example usage (section):
4057 # Pretend to use Canadian language settings.
4058 {+hide-accept-language{en-ca} \
4059 +hide-user-agent{Mozilla/5.0 (X11; U; OpenBSD i386; en-CA; rv:1.8.0.4) Gecko/20060628 Firefox/1.5.0.4} \
4064 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4066 8.5.20. hide-content-disposition
4070 Prevent download menus for content you prefer to view inside the browser.
4074 Deletes or replaces the "Content-Disposition:" HTTP header set by some
4083 Keyword: "block", or any user defined value.
4087 Some servers set the "Content-Disposition:" HTTP header for documents they
4088 assume you want to save locally before viewing them. The
4089 "Content-Disposition:" header contains the file name the browser is
4090 supposed to use by default.
4092 In most browsers that understand this header, it makes it impossible to
4093 just view the document, without downloading it first, even if it's just a
4094 simple text file or an image.
4096 Removing the "Content-Disposition:" header helps to prevent this annoyance,
4097 but some browsers additionally check the "Content-Type:" header, before
4098 they decide if they can display a document without saving it first. In
4099 these cases, you have to change this header as well, before the browser
4100 stops displaying download menus.
4102 It is also possible to change the server's file name suggestion to another
4103 one, but in most cases it isn't worth the time to set it up.
4105 This action will probably be removed in the future, use server-header
4110 # Disarm the download link in Sourceforge's patch tracker
4112 +content-type-overwrite{text/plain}\
4113 +hide-content-disposition{block} }
4114 .sourceforge.net/tracker/download\.php
4117 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4119 8.5.21. hide-if-modified-since
4123 Prevent yet another way to track the user's steps between sessions.
4127 Deletes the "If-Modified-Since:" HTTP client header or modifies its value.
4135 Keyword: "block", or a user defined value that specifies a range of hours.
4139 Removing this header is useful for filter testing, where you want to force
4140 a real reload instead of getting status code "304", which would cause the
4141 browser to use a cached copy of the page.
4143 Instead of removing the header, hide-if-modified-since can also add or
4144 subtract a random amount of time to/from the header's value. You specify a
4145 range of minutes where the random factor should be chosen from and Privoxy
4146 does the rest. A negative value means subtracting, a positive value adding.
4148 Randomizing the value of the "If-Modified-Since:" makes sure it isn't used
4149 as a cookie replacement, but you will run into caching problems if the
4150 random range is too high.
4152 It is a good idea to only use a small negative value and let
4153 overwrite-last-modified handle the greater changes.
4155 It is also recommended to use this action together with
4156 crunch-if-none-match.
4158 Example usage (section):
4160 # Let the browser revalidate without being tracked across sessions
4161 { +hide-if-modified-since{-60} \
4162 +overwrite-last-modified{randomize} \
4163 +crunch-if-none-match}
4167 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4169 8.5.22. hide-forwarded-for-headers
4173 Improve privacy by not embedding the source of the request in the HTTP
4178 Deletes any existing "X-Forwarded-for:" HTTP header from client requests,
4179 and prevents adding a new one.
4191 It is safe to leave this on.
4195 +hide-forwarded-for-headers
4198 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4200 8.5.23. hide-from-header
4204 Keep your (old and ill) browser from telling web servers your email address
4208 Deletes any existing "From:" HTTP header, or replaces it with the specified
4217 Keyword: "block", or any user defined value.
4221 The keyword "block" will completely remove the header (not to be confused
4222 with the block action).
4224 Alternately, you can specify any value you prefer to be sent to the web
4225 server. If you do, it is a matter of fairness not to use any address that
4226 is actually used by a real person.
4228 This action is rarely needed, as modern web browsers don't send "From:"
4233 +hide-from-header{block}
4238 +hide-from-header{spam-me-senseless@sittingduck.example.com}
4241 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4243 8.5.24. hide-referrer
4247 Conceal which link you followed to get to a particular site
4251 Deletes the "Referer:" (sic) HTTP header from the client request, or
4252 replaces it with a forged one.
4260 □ "conditional-block" to delete the header completely if the host has
4263 □ "block" to delete the header unconditionally.
4265 □ "forge" to pretend to be coming from the homepage of the server we are
4268 □ Any other string to set a user defined referrer.
4272 conditional-block is the only parameter, that isn't easily detected in the
4273 server's log file. If it blocks the referrer, the request will look like
4274 the visitor used a bookmark or typed in the address directly.
4276 Leaving the referrer unmodified for requests on the same host allows the
4277 server owner to see the visitor's "click path", but in most cases she could
4278 also get that information by comparing other parts of the log file: for
4279 example the User-Agent if it isn't a very common one, or the user's IP
4280 address if it doesn't change between different requests.
4282 Always blocking the referrer, or using a custom one, can lead to failures
4283 on servers that check the referrer before they answer any requests, in an
4284 attempt to prevent their valuable content from being embedded or linked to
4287 Both conditional-block and forge will work with referrer checks, as long as
4288 content and valid referring page are on the same host. Most of the time
4291 hide-referer is an alternate spelling of hide-referrer and the two can be
4292 can be freely substituted with each other. ("referrer" is the correct
4293 English spelling, however the HTTP specification has a bug - it requires it
4294 to be spelled as "referer".)
4298 +hide-referrer{forge}
4303 +hide-referrer{http://www.yahoo.com/}
4306 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4308 8.5.25. hide-user-agent
4312 Conceal your type of browser and client operating system
4316 Replaces the value of the "User-Agent:" HTTP header in client requests with
4317 the specified value.
4325 Any user-defined string.
4329 ┌─────────────────────────────────────────────────────────────────┐
4331 ├─────────────────────────────────────────────────────────────────┤
4332 │This can lead to problems on web sites that depend on looking at │
4333 │this header in order to customize their content for different │
4334 │browsers (which, by the way, is NOT the right thing to do: good │
4335 │web sites work browser-independently). │
4336 └─────────────────────────────────────────────────────────────────┘
4338 Using this action in multi-user setups or wherever different types of
4339 browsers will access the same Privoxy is not recommended. In single-user,
4340 single-browser setups, you might use it to delete your OS version
4341 information from the headers, because it is an invitation to exploit known
4342 bugs for your OS. It is also occasionally useful to forge this in order to
4343 access sites that won't let you in otherwise (though there may be a good
4344 reason in some cases). Example of this: some MSN sites will not let Mozilla
4345 enter, yet forging to a Netscape 6.1 user-agent works just fine. (Must be
4346 just a silly MS goof, I'm sure :-).
4348 More information on known user-agent strings can be found at http://
4349 www.user-agents.org/ and http://en.wikipedia.org/wiki/User_agent.
4353 +hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}
4356 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4358 8.5.26. inspect-jpegs
4362 To protect against the MS buffer over-run in JPEG processing
4366 Protect against a known exploit
4378 See Microsoft Security Bulletin MS04-028. JPEG images are one of the most
4379 common image types found across the Internet. The exploit as described can
4380 allow execution of code on the target system, giving an attacker access to
4381 the system in question by merely planting an altered JPEG image, which
4382 would have no obvious indications of what lurks inside. This action
4383 prevents this exploit.
4385 Note that the described exploit is only one of many, using this action does
4386 not mean that you no longer have to patch the client.
4393 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4399 Eliminate those annoying pop-up windows (deprecated)
4403 While loading the document, replace JavaScript code that opens pop-up
4404 windows with (syntactically neutral) dummy code on the fly.
4416 This action is basically a built-in, hardwired special-purpose filter
4417 action, but there are important differences: For kill-popups, the document
4418 need not be buffered, so it can be incrementally rendered while
4419 downloading. But kill-popups doesn't catch as many pop-ups as filter
4420 {all-popups} does and is not as smart as filter{unsolicited-popups} is.
4422 Think of it as a fast and efficient replacement for a filter that you can
4423 use if you don't want any filtering at all. Note that it doesn't make sense
4424 to combine it with any filter action, since as soon as one filter applies,
4425 the whole document needs to be buffered anyway, which destroys the
4426 advantage of the kill-popups action over its filter equivalent.
4428 Killing all pop-ups unconditionally is problematic. Many shops and banks
4429 rely on pop-ups to display forms, shopping carts etc, and the filter
4430 {unsolicited-popups} does a better job of catching only the unwanted ones.
4432 If the only kind of pop-ups that you want to kill are exit consoles (those
4433 really nasty windows that appear when you close an other one), you might
4434 want to use filter{js-annoyances} instead.
4436 This action is most appropriate for browsers that don't have any controls
4437 for unwanted pop-ups. Not recommended for general usage.
4444 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4446 8.5.28. limit-connect
4450 Prevent abuse of Privoxy as a TCP proxy relay or disable SSL for untrusted
4455 Specifies to which ports HTTP CONNECT requests are allowable.
4463 A comma-separated list of ports or port ranges (the latter using dashes,
4464 with the minimum defaulting to 0 and the maximum to 65K).
4468 By default, i.e. if no limit-connect action applies, Privoxy only allows
4469 HTTP CONNECT requests to port 443 (the standard, secure HTTPS port). Use
4470 limit-connect if more fine-grained control is desired for some or all
4473 The CONNECT methods exists in HTTP to allow access to secure websites
4474 ("https://" URLs) through proxies. It works very simply: the proxy connects
4475 to the server on the specified port, and then short-circuits its
4476 connections to the client and to the remote server. This can be a big
4477 security hole, since CONNECT-enabled proxies can be abused as TCP relays
4480 Privoxy relays HTTPS traffic without seeing the decoded content. Websites
4481 can leverage this limitation to circumvent Privoxy's filters. By specifying
4482 an invalid port range you can disable HTTPS entirely. If you plan to
4483 disable SSL by default, consider enabling
4484 treat-forbidden-connects-like-blocks as well, to be able to quickly create
4489 +limit-connect{443} # This is the default and need not be specified.
4490 +limit-connect{80,443} # Ports 80 and 443 are OK.
4491 +limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
4492 +limit-connect{-} # All ports are OK
4493 +limit-connect{,} # No HTTPS/SSL traffic is allowed
4496 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4498 8.5.29. prevent-compression
4502 Ensure that servers send the content uncompressed, so it can be passed
4507 Removes the Accept-Encoding header which can be used to ask for compressed
4520 More and more websites send their content compressed by default, which is
4521 generally a good idea and saves bandwidth. But the filter, deanimate-gifs
4522 and kill-popups actions need access to the uncompressed data.
4524 When compiled with zlib support (available since Privoxy 3.0.7), content
4525 that should be filtered is decompressed on-the-fly and you don't have to
4526 worry about this action. If you are using an older Privoxy version, or one
4527 that hasn't been compiled with zlib support, this action can be used to
4528 convince the server to send the content uncompressed.
4530 Most text-based instances compress very well, the size is seldom decreased
4531 by less than 50%, for markup-heavy instances like news feeds saving more
4532 than 90% of the original size isn't unusual.
4534 Not using compression will therefore slow down the transfer, and you should
4535 only enable this action if you really need it. As of Privoxy 3.0.7 it's
4536 disabled in all predefined action settings.
4538 Note that some (rare) ill-configured sites don't handle requests for
4539 uncompressed documents correctly. Broken PHP applications tend to send an
4540 empty document body, some IIS versions only send the beginning of the
4541 content. If you enable prevent-compression per default, you might want to
4542 add exceptions for those sites. See the example for how to do that.
4544 Example usage (sections):
4546 # Selectively turn off compression, and enable a filter
4548 { +filter{tiny-textforms} +prevent-compression }
4549 # Match only these sites
4554 # Or instead, we could set a universal default:
4556 { +prevent-compression }
4559 # Then maybe make exceptions for broken sites:
4561 { -prevent-compression }
4565 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4567 8.5.30. overwrite-last-modified
4571 Prevent yet another way to track the user's steps between sessions.
4575 Deletes the "Last-Modified:" HTTP server header or modifies its value.
4583 One of the keywords: "block", "reset-to-request-time" and "randomize"
4587 Removing the "Last-Modified:" header is useful for filter testing, where
4588 you want to force a real reload instead of getting status code "304", which
4589 would cause the browser to reuse the old version of the page.
4591 The "randomize" option overwrites the value of the "Last-Modified:" header
4592 with a randomly chosen time between the original value and the current
4593 time. In theory the server could send each document with a different
4594 "Last-Modified:" header to track visits without using cookies. "Randomize"
4595 makes it impossible and the browser can still revalidate cached documents.
4597 "reset-to-request-time" overwrites the value of the "Last-Modified:" header
4598 with the current time. You could use this option together with
4599 hided-if-modified-since to further customize your random range.
4601 The preferred parameter here is "randomize". It is safe to use, as long as
4602 the time settings are more or less correct. If the server sets the
4603 "Last-Modified:" header to the time of the request, the random range
4604 becomes zero and the value stays the same. Therefore you should later
4605 randomize it a second time with hided-if-modified-since, just to be sure.
4607 It is also recommended to use this action together with
4608 crunch-if-none-match.
4612 # Let the browser revalidate without being tracked across sessions
4613 { +hide-if-modified-since{-60} \
4614 +overwrite-last-modified{randomize} \
4615 +crunch-if-none-match}
4619 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4625 Redirect requests to other sites.
4629 Convinces the browser that the requested document has been moved to another
4630 location and the browser should get it from there.
4638 An absolute URL or a single pcrs command.
4642 Requests to which this action applies are answered with a HTTP redirect to
4643 URLs of your choosing. The new URL is either provided as parameter, or
4644 derived by applying a single pcrs command to the original URL.
4646 This action will be ignored if you use it together with block. It can be
4647 combined with fast-redirects{check-decoded-url} to redirect to a decoded
4648 version of a rewritten URL.
4650 Use this action carefully, make sure not to create redirection loops and be
4651 aware that using your own redirects might make it possible to fingerprint
4656 # Replace example.com's style sheet with another one
4657 { +redirect{http://localhost/css-replacements/example.com.css} }
4658 example.com/stylesheet\.css
4660 # Create a short, easy to remember nickname for a favorite site
4661 # (relies on the browser accept and forward invalid URLs to Privoxy)
4662 { +redirect{http://www.privoxy.org/user-manual/actions-file.html} }
4665 # Always use the expanded view for Undeadly.org articles
4666 # (Note the $ at the end of the URL pattern to make sure
4667 # the request for the rewritten URL isn't redirected as well)
4668 {+redirect{s@$@&mode=expanded@}}
4669 undeadly.org/cgi\?action=article&sid=\d*$
4672 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4674 8.5.32. send-vanilla-wafer
4678 Feed log analysis scripts with useless data.
4682 Sends a cookie with each request stating that you do not accept any
4683 copyright on cookies sent to you, and asking the site operator not to track
4696 The vanilla wafer is a (relatively) unique header and could conceivably be
4699 This action is rarely used and not enabled in the default configuration.
4706 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4712 Send custom cookies or feed log analysis scripts with even more useless
4717 Sends a custom, user-defined cookie with each request.
4725 A string of the form "name=value".
4729 Being multi-valued, multiple instances of this action can apply to the same
4730 request, resulting in multiple cookies being sent.
4732 This action is rarely used and not enabled in the default configuration.
4734 Example usage (section):
4736 {+send-wafer{UsingPrivoxy=true}}
4737 my-internal-testing-server.void
4740 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4742 8.5.34. server-header-filter
4746 Rewrite or remove single server headers.
4750 All server headers to which this action applies are filtered on-the-fly
4751 through the specified regular expression based substitutions.
4759 The name of a server-header filter, as defined in one of the filter files.
4763 Server-header filters are applied to each header on its own, not to all at
4764 once. This makes it easier to diagnose problems, but on the downside you
4765 can't write filters that only change header x if header y's value is z. You
4766 can do that by using tags though.
4768 Server-header filters are executed after the other header actions have
4769 finished and use their output as input.
4771 Please refer to the filter file chapter to learn which server-header
4772 filters are available by default, and how to create your own.
4774 Example usage (section):
4776 {+server-header-filter{html-to-xml}}
4777 example.org/xml-instance-that-is-delivered-as-html
4779 {+server-header-filter{xml-to-html}}
4780 example.org/instance-that-is-delivered-as-xml-but-is-not
4784 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4786 8.5.35. server-header-tagger
4790 Enable or disable filters based on the Content-Type header.
4794 Server headers to which this action applies are filtered on-the-fly through
4795 the specified regular expression based substitutions, the result is used as
4804 The name of a server-header tagger, as defined in one of the filter files.
4808 Server-header taggers are applied to each header on its own, and as the
4809 header isn't modified, each tagger "sees" the original.
4811 Server-header taggers are executed before all other header actions that
4812 modify server headers. Their tags can be used to control all of the other
4813 server-header actions, the content filters and the crunch actions (redirect
4816 Obviously crunching based on tags created by server-header taggers doesn't
4817 prevent the request from showing up in the server's log file.
4819 Example usage (section):
4821 # Tag every request with the content type declared by the server
4822 {+server-header-tagger{content-type}}
4827 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4829 8.5.36. session-cookies-only
4833 Allow only temporary "session" cookies (for the current browser session
4838 Deletes the "expires" field from "Set-Cookie:" server headers. Most
4839 browsers will not store such cookies permanently and forget them in between
4852 This is less strict than crunch-incoming-cookies / crunch-outgoing-cookies
4853 and allows you to browse websites that insist or rely on setting cookies,
4854 without compromising your privacy too badly.
4856 Most browsers will not permanently store cookies that have been processed
4857 by session-cookies-only and will forget about them between sessions. This
4858 makes profiling cookies useless, but won't break sites which require
4859 cookies so that you can log in for transactions. This is generally turned
4860 on for all sites, and is the recommended setting.
4862 It makes no sense at all to use session-cookies-only together with
4863 crunch-incoming-cookies or crunch-outgoing-cookies. If you do, cookies will
4866 Note that it is up to the browser how it handles such cookies without an
4867 "expires" field. If you use an exotic browser, you might want to try it out
4870 This setting also has no effect on cookies that may have been stored
4871 previously by the browser before starting Privoxy. These would have to be
4874 Privoxy also uses the content-cookies filter to block some types of
4875 cookies. Content cookies are not effected by session-cookies-only.
4879 +session-cookies-only
4882 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4884 8.5.37. set-image-blocker
4888 Choose the replacement for blocked images
4892 This action alone doesn't do anything noticeable. If both block and
4893 handle-as-image also apply, i.e. if the request is to be blocked as an
4894 image, then the parameter of this action decides what will be sent as a
4903 □ "pattern" to send a built-in checkerboard pattern image. The image is
4904 visually decent, scales very well, and makes it obvious where banners
4907 □ "blank" to send a built-in transparent image. This makes banners
4908 disappear completely, but makes it hard to detect where Privoxy has
4909 blocked images on a given page and complicates troubleshooting if
4910 Privoxy has blocked innocent images, like navigation icons.
4912 □ "target-url" to send a redirect to target-url. You can redirect to any
4913 image anywhere, even in your local filesystem via "file:///" URL. (But
4914 note that not all browsers support redirecting to a local file system).
4916 A good application of redirects is to use special Privoxy-built-in
4917 URLs, which send the built-in images, as target-url. This has the same
4918 visual effect as specifying "blank" or "pattern" in the first place,
4919 but enables your browser to cache the replacement image, instead of
4920 requesting it over and over again.
4924 The URLs for the built-in images are "http://config.privoxy.org/
4925 send-banner?type=type", where type is either "blank" or "pattern".
4927 There is a third (advanced) type, called "auto". It is NOT to be used in
4928 set-image-blocker, but meant for use from filters. Auto will select the
4929 type of image that would have applied to the referring page, had it been an
4936 +set-image-blocker{pattern}
4939 Redirect to the BSD daemon:
4941 +set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}
4944 Redirect to the built-in pattern for better caching:
4946 +set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}
4949 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4951 8.5.38. treat-forbidden-connects-like-blocks
4955 Block forbidden connects with an easy to find error message.
4959 If this action is enabled, Privoxy no longer makes a difference between
4960 forbidden connects and ordinary blocks.
4972 By default Privoxy answers forbidden "Connect" requests with a short error
4973 message inside the headers. If the browser doesn't display headers (most
4974 don't), you just see an empty page.
4976 With this action enabled, Privoxy displays the message that is used for
4977 ordinary blocks instead. If you decide to make an exception for the page in
4978 question, you can do so by following the "See why" link.
4980 For "Connect" requests the clients tell Privoxy which host they are
4981 interested in, but not which document they plan to get later. As a result,
4982 the "Go there anyway" wouldn't work and is therefore suppressed.
4986 +treat-forbidden-connects-like-blocks
4989 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4993 Note that many of these actions have the potential to cause a page to
4994 misbehave, possibly even not to display at all. There are many ways a site
4995 designer may choose to design his site, and what HTTP header content, and other
4996 criteria, he may depend on. There is no way to have hard and fast rules for all
4997 sites. See the Appendix for a brief example on troubleshooting actions.
4999 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
5003 Custom "actions", known to Privoxy as "aliases", can be defined by combining
5004 other actions. These can in turn be invoked just like the built-in actions.
5005 Currently, an alias name can contain any character except space, tab, "=", "{"
5006 and "}", but we strongly recommend that you only use "a" to "z", "0" to "9",
5007 "+", and "-". Alias names are not case sensitive, and are not required to start
5008 with a "+" or "-" sign, since they are merely textually expanded.
5010 Aliases can be used throughout the actions file, but they must be defined in a
5011 special section at the top of the file! And there can only be one such section
5012 per actions file. Each actions file may have its own alias section, and the
5013 aliases defined in it are only visible within that file.
5015 There are two main reasons to use aliases: One is to save typing for frequently
5016 used combinations of actions, the other one is a gain in flexibility: If you
5017 decide once how you want to handle shops by defining an alias called "shop",
5018 you can later change your policy on shops in one place, and your changes will
5019 take effect everywhere in the actions file where the "shop" alias is used.
5020 Calling aliases by their purpose also makes your actions files more readable.
5022 Currently, there is one big drawback to using aliases, though: Privoxy's
5023 built-in web-based action file editor honors aliases when reading the actions
5024 files, but it expands them before writing. So the effects of your aliases are
5025 of course preserved, but the aliases themselves are lost when you edit sections
5026 that use aliases with it.
5028 Now let's define some aliases...
5030 # Useful custom aliases we can use later.
5032 # Note the (required!) section header line and that this section
5033 # must be at the top of the actions file!
5037 # These aliases just save typing later:
5038 # (Note that some already use other aliases!)
5040 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
5041 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
5042 +block-as-image = +block +handle-as-image
5043 allow-all-cookies = -crunch-all-cookies -session-cookies-only -filter{content-cookies}
5045 # These aliases define combinations of actions
5046 # that are useful for certain types of sites:
5048 fragile = -block -filter -crunch-all-cookies -fast-redirects -hide-referrer -kill-popups -prevent-compression
5050 shop = -crunch-all-cookies -filter{all-popups} -kill-popups
5052 # Short names for other aliases, for really lazy people ;-)
5054 c0 = +crunch-all-cookies
5055 c1 = -crunch-all-cookies
5058 ...and put them to use. These sections would appear in the lower part of an
5059 actions file and define exceptions to the default actions (as specified further
5060 up for the "/" pattern):
5062 # These sites are either very complex or very keen on
5063 # user data and require minimal interference to work:
5066 .office.microsoft.com
5067 .windowsupdate.microsoft.com
5068 # Gmail is really mail.google.com, not gmail.com
5072 # Allow cookies (for setting and retrieving your customer data)
5076 .worldpay.com # for quietpc.com
5079 # These shops require pop-ups:
5081 {-kill-popups -filter{all-popups} -filter{unsolicited-popups}}
5086 Aliases like "shop" and "fragile" are typically used for "problem" sites that
5087 require more than one action to be disabled in order to function properly.
5089 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
5091 8.7. Actions Files Tutorial
5093 The above chapters have shown which actions files there are and how they are
5094 organized, how actions are specified and applied to URLs, how patterns work,
5095 and how to define and use aliases. Now, let's look at an example default.action
5096 and user.action file and see how all these pieces come together:
5098 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
5100 8.7.1. default.action
5102 Every config file should start with a short comment stating its purpose:
5104 # Sample default.action file <ijbswa-developers@lists.sourceforge.net>
5107 Then, since this is the default.action file, the first section is a special
5108 section for internal use that you needn't change or worry about:
5110 ##########################################################################
5111 # Settings -- Don't change! For internal Privoxy use ONLY.
5112 ##########################################################################
5115 for-privoxy-version=3.0
5118 After that comes the (optional) alias section. We'll use the example section
5119 from the above chapter on aliases, that also explains why and how aliases are
5122 ##########################################################################
5124 ##########################################################################
5127 # These aliases just save typing later:
5128 # (Note that some already use other aliases!)
5130 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
5131 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
5132 +block-as-image = +block +handle-as-image
5133 mercy-for-cookies = -crunch-all-cookies -session-cookies-only -filter{content-cookies}
5135 # These aliases define combinations of actions
5136 # that are useful for certain types of sites:
5138 fragile = -block -filter -crunch-all-cookies -fast-redirects -hide-referrer -kill-popups
5139 shop = -crunch-all-cookies -filter{all-popups} -kill-popups
5142 Now come the regular sections, i.e. sets of actions, accompanied by URL
5143 patterns to which they apply. Remember all actions are disabled when matching
5144 starts, so we have to explicitly enable the ones we want.
5146 The first regular section is probably the most important. It has only one
5147 pattern, "/", but this pattern matches all URLs. Therefore, the set of actions
5148 used in this "default" section will be applied to all requests as a start. It
5149 can be partly or wholly overridden by later matches further down this file, or
5150 in user.action, but it will still be largely responsible for your overall
5151 browsing experience.
5153 Again, at the start of matching, all actions are disabled, so there is no need
5154 to disable any actions here. (Remember: a "+" preceding the action name enables
5155 the action, a "-" disables!). Also note how this long line has been made more
5156 readable by splitting it into multiple lines with line continuation.
5158 ##########################################################################
5159 # "Defaults" section:
5160 ##########################################################################
5163 +filter{html-annoyances} \
5164 +filter{refresh-tags} \
5166 +filter{ie-exploits} \
5167 +hide-forwarded-for-headers \
5168 +hide-from-header{block} \
5169 +hide-referrer{forge} \
5170 +prevent-compression \
5171 +session-cookies-only \
5172 +set-image-blocker{pattern} \
5174 / # forward slash will match *all* potential URL patterns.
5177 The default behavior is now set.
5179 The first of our specialized sections is concerned with "fragile" sites, i.e.
5180 sites that require minimum interference, because they are either very complex
5181 or very keen on tracking you (and have mechanisms in place that make them
5182 unusable for people who avoid being tracked). We will simply use our
5183 pre-defined fragile alias instead of stating the list of actions explicitly:
5185 ##########################################################################
5186 # Exceptions for sites that'll break under the default action set:
5187 ##########################################################################
5189 # "Fragile" Use a minimum set of actions for these sites (see alias above):
5192 .office.microsoft.com # surprise, surprise!
5193 .windowsupdate.microsoft.com
5197 Shopping sites are not as fragile, but they typically require cookies to log
5198 in, and pop-up windows for shopping carts or item details. Again, we'll use a
5205 .worldpay.com # for quietpc.com
5210 The fast-redirects action, which we enabled per default above, breaks some
5211 sites. So disable it for popular sites where we know it misbehaves:
5217 .altavista.com/.*(like|url|link):http
5218 .altavista.com/trans.*urltext=http
5222 It is important that Privoxy knows which URLs belong to images, so that if they
5223 are to be blocked, a substitute image can be sent, rather than an HTML page.
5224 Contacting the remote site to find out is not an option, since it would destroy
5225 the loading time advantage of banner blocking, and it would feed the
5226 advertisers (in terms of money and information). We can mark any URL as an
5227 image with the handle-as-image action, and marking all URLs that end in a known
5228 image file extension is a good start:
5230 ##########################################################################
5232 ##########################################################################
5234 # Define which file types will be treated as images, in case they get
5235 # blocked further down this file:
5237 { +handle-as-image }
5238 /.*\.(gif|jpe?g|png|bmp|ico)$
5241 And then there are known banner sources. They often use scripts to generate the
5242 banners, so it won't be visible from the URL that the request is for an image.
5243 Hence we block them and mark them as images in one go, with the help of our
5244 +block-as-image alias defined above. (We could of course just as well use +
5245 block +handle-as-image here.) Remember that the type of the replacement image
5246 is chosen by the set-image-blocker action. Since all URLs have matched the
5247 default section with its +set-image-blocker{pattern} action before, it still
5248 applies and needn't be repeated:
5250 # Known ad generators:
5255 .ad.*.doubleclick.net
5256 .a.yimg.com/(?:(?!/i/).)*$
5257 .a[0-9].yimg.com/(?:(?!/i/).)*$
5262 One of the most important jobs of Privoxy is to block banners. Many of these
5263 can be "blocked" by the filter{banners-by-size} action, which we enabled above,
5264 and which deletes the references to banner images from the pages while they are
5265 loaded, so the browser doesn't request them anymore, and hence they don't need
5266 to be blocked here. But this naturally doesn't catch all banners, and some
5267 people choose not to use filters, so we need a comprehensive list of patterns
5268 for banner URLs here, and apply the block action to them.
5270 First comes many generic patterns, which do most of the work, by matching
5271 typical domain and path name components of banners. Then comes a list of
5272 individual patterns for specific sites, which is omitted here to keep the
5275 ##########################################################################
5276 # Block these fine banners:
5277 ##########################################################################
5286 /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
5287 /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
5289 # Site-specific patterns (abbreviated):
5294 It's quite remarkable how many advertisers actually call their banner servers
5295 ads.company.com, or call the directory in which the banners are stored simply
5296 "banners". So the above generic patterns are surprisingly effective.
5298 But being very generic, they necessarily also catch URLs that we don't want to
5299 block. The pattern .*ads. e.g. catches "nasty-ads.nasty-corp.com" as intended,
5300 but also "downloads.sourcefroge.net" or "adsl.some-provider.net." So here come
5301 some well-known exceptions to the +block section above.
5303 Note that these are exceptions to exceptions from the default! Consider the URL
5304 "downloads.sourcefroge.net": Initially, all actions are deactivated, so it
5305 wouldn't get blocked. Then comes the defaults section, which matches the URL,
5306 but just deactivates the block action once again. Then it matches .*ads., an
5307 exception to the general non-blocking policy, and suddenly +block applies. And
5308 now, it'll match .*loads., where -block applies, so (unless it matches again
5309 further down) it ends up with no block action applying.
5311 ##########################################################################
5312 # Save some innocent victims of the above generic block patterns:
5313 ##########################################################################
5318 adv[io]*. # (for advogato.org and advice.*)
5319 adsl. # (has nothing to do with ads)
5320 adobe. # (has nothing to do with ads either)
5321 ad[ud]*. # (adult.* and add.*)
5322 .edu # (universities don't host banners (yet!))
5323 .*loads. # (downloads, uploads etc)
5331 www.globalintersec.com/adv # (adv = advanced)
5332 www.ugu.com/sui/ugu/adv
5335 Filtering source code can have nasty side effects, so make an exception for our
5336 friends at sourceforge.net, and all paths with "cvs" in them. Note that -filter
5337 disables all filters in one fell swoop!
5339 # Don't filter code!
5349 The actual default.action is of course much more comprehensive, but we hope
5350 this example made clear how it works.
5352 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
5356 So far we are painting with a broad brush by setting general policies, which
5357 would be a reasonable starting point for many people. Now, you might want to be
5358 more specific and have customized rules that are more suitable to your personal
5359 habits and preferences. These would be for narrowly defined situations like
5360 your ISP or your bank, and should be placed in user.action, which is parsed
5361 after all other actions files and hence has the last word, over-riding any
5362 previously defined actions. user.action is also a safe place for your personal
5363 settings, since default.action is actively maintained by the Privoxy developers
5364 and you'll probably want to install updated versions from time to time.
5366 So let's look at a few examples of things that one might typically do in
5369 # My user.action file. <fred@example.com>
5372 As aliases are local to the actions file that they are defined in, you can't
5373 use the ones from default.action, unless you repeat them here:
5375 # Aliases are local to the file they are defined in.
5376 # (Re-)define aliases for this file:
5380 # These aliases just save typing later, and the alias names should
5381 # be self explanatory.
5383 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
5384 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
5385 allow-all-cookies = -crunch-all-cookies -session-cookies-only
5386 allow-popups = -filter{all-popups} -kill-popups
5387 +block-as-image = +block +handle-as-image
5388 -block-as-image = -block
5390 # These aliases define combinations of actions that are useful for
5391 # certain types of sites:
5393 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referrer -kill-popups
5394 shop = -crunch-all-cookies allow-popups
5396 # Allow ads for selected useful free sites:
5398 allow-ads = -block -filter{banners-by-size} -filter{banners-by-link}
5400 # Alias for specific file types that are text, but might have conflicting
5401 # MIME types. We want the browser to force these to be text documents.
5402 handle-as-text = -filter +-content-type-overwrite{text/plain} +-force-text-mode -hide-content-disposition
5407 Say you have accounts on some sites that you visit regularly, and you don't
5408 want to have to log in manually each time. So you'd like to allow persistent
5409 cookies for these sites. The allow-all-cookies alias defined above does exactly
5410 that, i.e. it disables crunching of cookies in any direction, and the
5411 processing of cookies to make them only temporary.
5413 { allow-all-cookies }
5420 Your bank is allergic to some filter, but you don't know which, so you disable
5424 .your-home-banking-site.com
5427 Some file types you may not want to filter for various reasons:
5429 # Technical documentation is likely to contain strings that might
5430 # erroneously get altered by the JavaScript-oriented filters:
5435 # And this stupid host sends streaming video with a wrong MIME type,
5436 # so that Privoxy thinks it is getting HTML and starts filtering:
5438 stupid-server.example.com/
5441 Example of a simple block action. Say you've seen an ad on your favourite page
5442 on example.com that you want to get rid of. You have right-clicked the image,
5443 selected "copy image location" and pasted the URL below while removing the
5444 leading http://, into a { +block } section. Note that { +handle-as-image } need
5445 not be specified, since all URLs ending in .gif will be tagged as images by the
5446 general rules as set in default.action anyway:
5449 www.example.com/nasty-ads/sponsor\.gif
5450 another.example.net/more/junk/here/
5453 The URLs of dynamically generated banners, especially from large banner farms,
5454 often don't use the well-known image file name extensions, which makes it
5455 impossible for Privoxy to guess the file type just by looking at the URL. You
5456 can use the +block-as-image alias defined above for these cases. Note that
5457 objects which match this rule but then turn out NOT to be an image are
5458 typically rendered as a "broken image" icon by the browser. Use cautiously.
5467 Now you noticed that the default configuration breaks Forbes Magazine, but you
5468 were too lazy to find out which action is the culprit, and you were again too
5469 lazy to give feedback, so you just used the fragile alias on the site, and --
5470 whoa! -- it worked. The fragile aliases disables those actions that are most
5471 likely to break a site. Also, good for testing purposes to see if it is Privoxy
5472 that is causing the problem or not. We later find other regular sites that
5473 misbehave, and add those to our personalized list of troublemakers:
5481 You like the "fun" text replacements in default.filter, but it is disabled in
5482 the distributed actions file. So you'd like to turn it on in your private,
5483 update-safe config, once and for all:
5489 Note that the above is not really a good idea: There are exceptions to the
5490 filters in default.action for things that really shouldn't be filtered, like
5491 code on CVS->Web interfaces. Since user.action has the last word, these
5492 exceptions won't be valid for the "fun" filtering specified here.
5494 You might also worry about how your favourite free websites are funded, and
5495 find that they rely on displaying banner advertisements to survive. So you
5496 might want to specifically allow banners for those sites that you feel provide
5505 Note that allow-ads has been aliased to -block, -filter{banners-by-size}, and -
5506 filter{banners-by-link} above.
5508 Invoke another alias here to force an over-ride of the MIME type application/
5509 x-sh which typically would open a download type dialog. In my case, I want to
5510 look at the shell script, and then I can save it should I choose to.
5516 user.action is generally the best place to define exceptions and additions to
5517 the default policies of default.action. Some actions are safe to have their
5518 default policies set here though. So let's set a default policy to have a
5519 "blank" image as opposed to the checkerboard pattern for ALL sites. "/" of
5520 course matches all URL paths and patterns:
5522 { +set-image-blocker{blank} }
5526 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
5530 On-the-fly text substitutions need to be defined in a "filter file". Once
5531 defined, they can then be invoked as an "action".
5533 Privoxy supports three different filter actions: filter to rewrite the content
5534 that is send to the client, client-header-filter to rewrite headers that are
5535 send by the client, and server-header-filter to rewrite headers that are send
5538 Privoxy also supports two tagger actions: client-header-tagger and
5539 server-header-tagger. Taggers and filters use the same syntax in the filter
5540 files, the difference is that taggers don't modify the text they are filtering,
5541 but use a rewritten version of the filtered text as tag. The tags can then be
5542 used to change the applying actions through sections with tag-patterns.
5544 Multiple filter files can be defined through the filterfile config directive.
5545 The filters as supplied by the developers are located in default.filter. It is
5546 recommended that any locally defined or modified filters go in a separately
5547 defined file such as user.filter.
5549 Common tasks for content filters are to eliminate common annoyances in HTML and
5550 JavaScript, such as pop-up windows, exit consoles, crippled windows without
5551 navigation tools, the infamous <BLINK> tag etc, to suppress images with certain
5552 width and height attributes (standard banner sizes or web-bugs), or just to
5555 Enabled content filters are applied to any content whose "Content Type" header
5556 is recognised as a sign of text-based content, with the exception of text/
5557 plain. Use the force-text-mode action to also filter other content.
5559 Substitutions are made at the source level, so if you want to "roll your own"
5560 filters, you should first be familiar with HTML syntax, and, of course, regular
5563 Just like the actions files, the filter file is organized in sections, which
5564 are called filters here. Each filter consists of a heading line, that starts
5565 with one of the keywords FILTER:, CLIENT-HEADER-FILTER: or
5566 SERVER-HEADER-FILTER: followed by the filter's name, and a short (one line)
5567 description of what it does. Below that line come the jobs, i.e. lines that
5568 define the actual text substitutions. By convention, the name of a filter
5569 should describe what the filter eliminates. The comment is used in the
5570 web-based user interface.
5572 Once a filter called name has been defined in the filter file, it can be
5573 invoked by using an action of the form +filter{name} in any actions file.
5575 Filter definitions start with a header line that contains the filter type, the
5576 filter name and the filter description. A content filter header line for a
5577 filter called "foo" could look like this:
5579 FILTER: foo Replace all "foo" with "bar"
5582 Below that line, and up to the next header line, come the jobs that define what
5583 text replacements the filter executes. They are specified in a syntax that
5584 imitates Perl's s/// operator. If you are familiar with Perl, you will find
5585 this to be quite intuitive, and may want to look at the PCRS documentation for
5586 the subtle differences to Perl behaviour. Most notably, the non-standard option
5587 letter U is supported, which turns the default to ungreedy matching.
5589 If you are new to "Regular Expressions", you might want to take a look at the
5590 Appendix on regular expressions, and see the Perl manual for the s///
5591 operator's syntax and Perl-style regular expressions in general. The below
5592 examples might also help to get you started.
5594 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
5596 9.1. Filter File Tutorial
5598 Now, let's complete our "foo" content filter. We have already defined the
5599 heading, but the jobs are still missing. Since all it does is to replace "foo"
5600 with "bar", there is only one (trivial) job needed:
5605 But wait! Didn't the comment say that all occurrences of "foo" should be
5606 replaced? Our current job will only take care of the first "foo" on each page.
5607 For global substitution, we'll need to add the g option:
5612 Our complete filter now looks like this:
5614 FILTER: foo Replace all "foo" with "bar"
5618 Let's look at some real filters for more interesting examples. Here you see a
5619 filter that protects against some common annoyances that arise from JavaScript
5620 abuse. Let's look at its jobs one after the other:
5622 FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse
5624 # Get rid of JavaScript referrer tracking. Test page: http://www.randomoddness.com/untitled.htm
5626 s|(<script.*)document\.referrer(.*</script>)|$1"Not Your Business!"$2|Usg
5629 Following the header line and a comment, you see the job. Note that it uses |
5630 as the delimiter instead of /, because the pattern contains a forward slash,
5631 which would otherwise have to be escaped by a backslash (\).
5633 Now, let's examine the pattern: it starts with the text <script.* enclosed in
5634 parentheses. Since the dot matches any character, and * means: "Match an
5635 arbitrary number of the element left of myself", this matches "<script",
5636 followed by any text, i.e. it matches the whole page, from the start of the
5639 That's more than we want, but the pattern continues: document\.referrer matches
5640 only the exact string "document.referrer". The dot needed to be escaped, i.e.
5641 preceded by a backslash, to take away its special meaning as a joker, and make
5642 it just a regular dot. So far, the meaning is: Match from the start of the
5643 first <script> tag in a the page, up to, and including, the text
5644 "document.referrer", if both are present in the page (and appear in that
5647 But there's still more pattern to go. The next element, again enclosed in
5648 parentheses, is .*</script>. You already know what .* means, so the whole
5649 pattern translates to: Match from the start of the first <script> tag in a page
5650 to the end of the last <script> tag, provided that the text "document.referrer"
5651 appears somewhere in between.
5653 This is still not the whole story, since we have ignored the options and the
5654 parentheses: The portions of the page matched by sub-patterns that are enclosed
5655 in parentheses, will be remembered and be available through the variables $1,
5656 $2, ... in the substitute. The U option switches to ungreedy matching, which
5657 means that the first .* in the pattern will only "eat up" all text in between "
5658 <script" and the first occurrence of "document.referrer", and that the second
5659 .* will only span the text up to the first "</script>" tag. Furthermore, the s
5660 option says that the match may span multiple lines in the page, and the g
5661 option again means that the substitution is global.
5663 So, to summarize, the pattern means: Match all scripts that contain the text
5664 "document.referrer". Remember the parts of the script from (and including) the
5665 start tag up to (and excluding) the string "document.referrer" as $1, and the
5666 part following that string, up to and including the closing tag, as $2.
5668 Now the pattern is deciphered, but wasn't this about substituting things? So
5669 lets look at the substitute: $1"Not Your Business!"$2 is easy to read: The text
5670 remembered as $1, followed by "Not Your Business!" (including the quotation
5671 marks!), followed by the text remembered as $2. This produces an exact copy of
5672 the original string, with the middle part (the "document.referrer") replaced by
5673 "Not Your Business!".
5675 The whole job now reads: Replace "document.referrer" by "Not Your Business!"
5676 wherever it appears inside a <script> tag. Note that this job won't break
5677 JavaScript syntax, since both the original and the replacement are
5678 syntactically valid string objects. The script just won't have access to the
5679 referrer information anymore.
5681 We'll show you two other jobs from the JavaScript taming department, but this
5682 time only point out the constructs of special interest:
5684 # The status bar is for displaying link targets, not pointless blahblah
5686 s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig
5689 \s stands for whitespace characters (space, tab, newline, carriage return, form
5690 feed), so that \s* means: "zero or more whitespace". The ? in .*? makes this
5691 matching of arbitrary text ungreedy. (Note that the U option is not set). The
5692 ['"] construct means: "a single or a double quote". Finally, \1 is a
5693 back-reference to the first parenthesis just like $1 above, with the difference
5694 that in the pattern, a backslash indicates a back-reference, whereas in the
5695 substitute, it's the dollar.
5697 So what does this job do? It replaces assignments of single- or double-quoted
5698 strings to the "window.status" object with a dummy assignment (using a variable
5699 name that is hopefully odd enough not to conflict with real variables in
5700 scripts). Thus, it catches many cases where e.g. pointless descriptions are
5701 displayed in the status bar instead of the link target when you move your mouse
5704 # Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html
5706 s/(<body [^>]*)onunload(.*>)/$1never$2/iU
5709 Including the OnUnload event binding in the HTML DOM was a CRIME. When I close
5710 a browser window, I want it to close and die. Basta. This job replaces the
5711 "onunload" attribute in "<body>" tags with the dummy word never. Note that the
5712 i option makes the pattern matching case-insensitive. Also note that ungreedy
5713 matching alone doesn't always guarantee a minimal match: In the first
5714 parenthesis, we had to use [^>]* instead of .* to prevent the match from
5715 exceeding the <body> tag if it doesn't contain "OnUnload", but the page's
5718 The last example is from the fun department:
5720 FILTER: fun Fun text replacements
5722 # Spice the daily news:
5724 s/microsoft(?!\.com)/MicroSuck/ig
5727 Note the (?!\.com) part (a so-called negative lookahead) in the job's pattern,
5728 which means: Don't match, if the string ".com" appears directly following
5729 "microsoft" in the page. This prevents links to microsoft.com from being
5730 trashed, while still replacing the word everywhere else.
5732 # Buzzword Bingo (example for extended regex syntax)
5734 s* industry[ -]leading \
5736 | customer[ -]focused \
5737 | market[ -]driven \
5738 | award[ -]winning # Comments are OK, too! \
5739 | high[ -]performance \
5740 | solutions[ -]based \
5744 *<font color="red"><b>BINGO!</b></font> \
5748 The x option in this job turns on extended syntax, and allows for e.g. the
5749 liberal use of (non-interpreted!) whitespace for nicer formatting.
5753 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
5755 9.2. The Pre-defined Filters
5757 The distribution default.filter file contains a selection of pre-defined
5758 filters for your convenience:
5762 The purpose of this filter is to get rid of particularly annoying
5763 JavaScript abuse. To that end, it
5765 □ replaces JavaScript references to the browser's referrer information
5766 with the string "Not Your Business!". This compliments the
5767 hide-referrer action on the content level.
5769 □ removes the bindings to the DOM's unload event which we feel has no
5770 right to exist and is responsible for most "exit consoles", i.e. nasty
5771 windows that pop up when you close another one.
5773 □ removes code that causes new windows to be opened with undesired
5774 properties, such as being full-screen, non-resizeable, without
5775 location, status or menu bar etc.
5777 Use with caution. This is an aggressive filter, and can break sites that
5778 rely heavily on JavaScript.
5782 This is a very radical measure. It removes virtually all JavaScript event
5783 bindings, which means that scripts can not react to user actions such as
5784 mouse movements or clicks, window resizing etc, anymore. Use with caution!
5786 We strongly discourage using this filter as a default since it breaks many
5787 legitimate scripts. It is meant for use only on extra-nasty sites (should
5788 you really need to go there).
5792 This filter will undo many common instances of HTML based abuse.
5794 The BLINK and MARQUEE tags are neutralized (yeah baby!), and browser
5795 windows will be created as resizeable (as of course they should be!), and
5796 will have location, scroll and menu bars -- even if specified otherwise.
5800 Most cookies are set in the HTTP dialog, where they can be intercepted by
5801 the crunch-incoming-cookies and crunch-outgoing-cookies actions. But web
5802 sites increasingly make use of HTML meta tags and JavaScript to sneak
5803 cookies to the browser on the content level.
5805 This filter disables most HTML and JavaScript code that reads or sets
5806 cookies. It cannot detect all clever uses of these types of code, so it
5807 should not be relied on as an absolute fix. Use it wherever you would also
5808 use the cookie crunch actions.
5812 Disable any refresh tags if the interval is greater than nine seconds (so
5813 that redirections done via refresh tags are not destroyed). This is useful
5814 for dial-on-demand setups, or for those who find this HTML feature
5819 This filter attempts to prevent only "unsolicited" pop-up windows from
5820 opening, yet still allow pop-up windows that the user has explicitly chosen
5821 to open. It was added in version 3.0.1, as an improvement over earlier such
5824 Technical note: The filter works by redefining the window.open JavaScript
5825 function to a dummy function, PrivoxyWindowOpen(), during the loading and
5826 rendering phase of each HTML page access, and restoring the function
5829 This is recommended only for browsers that cannot perform this function
5830 reliably themselves. And be aware that some sites require such windows in
5831 order to function normally. Use with caution.
5835 Attempt to prevent all pop-up windows from opening. Note this should be
5836 used with even more discretion than the above, since it is more likely to
5837 break some sites that require pop-ups for normal usage. Use with caution.
5841 This is a helper filter that has no value if used alone. It makes the
5842 banners-by-size and banners-by-link (see below) filters more effective and
5843 should be enabled together with them.
5847 This filter removes image tags purely based on what size they are.
5848 Fortunately for us, many ads and banner images tend to conform to certain
5849 standardized sizes, which makes this filter quite effective for ad
5852 Occasionally this filter will cause false positives on images that are not
5853 ads, but just happen to be of one of the standard banner sizes.
5855 Recommended only for those who require extreme ad blocking. The default
5856 block rules should catch 95+% of all ads without this filter enabled.
5860 This is an experimental filter that attempts to kill any banners if their
5861 URLs seem to point to known or suspected click trackers. It is currently
5862 not of much value and is not recommended for use by default.
5866 Webbugs are small, invisible images (technically 1X1 GIF images), that are
5867 used to track users across websites, and collect information on them. As an
5868 HTML page is loaded by the browser, an embedded image tag causes the
5869 browser to contact a third-party site, disclosing the tracking information
5870 through the requested URL and/or cookies for that third-party domain,
5871 without the user ever becoming aware of the interaction with the
5872 third-party site. HTML-ized spam also uses a similar technique to verify
5875 This filter removes the HTML code that loads such "webbugs".
5879 A rather special-purpose filter that can be used to enlarge textareas
5880 (those multi-line text boxes in web forms) and turn off hard word wrap in
5881 them. It was written for the sourceforge.net tracker system where such
5882 boxes are a nuisance, but it can be handy on other sites, too.
5884 It is not recommended to use this filter as a default.
5888 Many consider windows that move, or resize themselves to be abusive. This
5889 filter neutralizes the related JavaScript code. Note that some sites might
5890 not display or behave as intended when using this filter. Use with caution.
5894 Some web designers seem to assume that everyone in the world will view
5895 their web sites using the same browser brand and version, screen resolution
5896 etc, because only that assumption could explain why they'd use static frame
5897 sizes, yet prevent their frames from being resized by the user, should they
5898 be too small to show their whole content.
5900 This filter removes the related HTML code. It should only be applied to
5901 sites which need it.
5905 Many Microsoft products that generate HTML use non-standard extensions
5906 (read: violations) of the ISO 8859-1 aka Latin-1 character set. This can
5907 cause those HTML documents to display with errors on standard-compliant
5910 This filter translates the MS-only characters into Latin-1 equivalents. It
5911 is not necessary when using MS products, and will cause corruption of all
5912 documents that use 8-bit character sets other than Latin-1. It's mostly
5913 worthwhile for Europeans on non-MS platforms, if weird garbage characters
5914 sometimes appear on some pages, or user agents that don't correct for this
5919 A filter for shockwave haters. As the name suggests, this filter strips
5920 code out of web pages that is used to embed shockwave flash objects.
5924 Change HTML code that embeds Quicktime objects so that kioskmode, which
5925 prevents saving, is disabled.
5929 Text replacements for subversive browsing fun. Make fun of your favorite
5930 Monopolist or play buzzword bingo.
5934 A demonstration-only filter that shows how Privoxy can be used to delete
5935 web content on a keyword basis.
5939 An experimental collection of text replacements to disable malicious HTML
5940 and JavaScript code that exploits known security holes in Internet
5943 Presently, it only protects against Nimda and a cross-site scripting bug,
5944 and would need active maintenance to provide more substantial protection.
5948 Some web sites have very specific problems, the cure for which doesn't
5949 apply anywhere else, or could even cause damage on other sites.
5951 This is a collection of such site-specific cures which should only be
5952 applied to the sites they were intended for, which is what the supplied
5953 default.action file does. Users shouldn't need to change anything regarding
5958 A CSS based block for Google text ads. Also removes a width limitation and
5959 the toolbar advertisement.
5963 Another CSS based block, this time for Yahoo text ads. And removes a width
5968 Another CSS based block, this time for MSN text ads. And removes tracking
5969 URLs, as well as a width limitation.
5973 Cleans up some Blogspot blogs. Read the fine print before using this one!
5975 This filter also intentionally removes some navigation stuff and sets the
5976 page width to 100%. As a result, some rounded "corners" would appear to
5977 early or not at all and as fixing this would require a browser that
5978 understands background-size (CSS3), they are removed instead.
5982 Server-header filter to change the Content-Type from xml to html.
5986 Server-header filter to change the Content-Type from html to xml.
5990 Removes the non-standard ping attribute from anchor and area HTML tags.
5992 hide-tor-exit-notation
5994 Client-header filter to remove the Tor exit node notation found in Host and
5997 If Privoxy and Tor are chained and Privoxy is configured to use socks4a,
5998 one can use "http://www.example.org.foobar.exit/" to access the host
5999 "www.example.org" through the Tor exit node "foobar".
6001 As the HTTP client isn't aware of this notation, it treats the whole string
6002 "www.example.org.foobar.exit" as host and uses it for the "Host" and
6003 "Referer" headers. From the server's point of view the resulting headers
6004 are invalid and can cause problems.
6006 An invalid "Referer" header can trigger "hot-linking" protections, an
6007 invalid "Host" header will make it impossible for the server to find the
6008 right vhost (several domains hosted on the same IP address).
6010 This client-header filter removes the "foo.exit" part in those headers to
6011 prevent the mentioned problems. Note that it only modifies the HTTP
6012 headers, it doesn't make it impossible for the server to detect your Tor
6013 exit node based on the IP address the request is coming from.
6015 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6017 10. Privoxy's Template Files
6019 All Privoxy built-in pages, i.e. error pages such as the "404 - No Such Domain"
6020 error page, the "BLOCKED" page and all pages of its web-based user interface,
6021 are generated from templates. (Privoxy must be running for the above links to
6024 These templates are stored in a subdirectory of the configuration directory
6025 called templates. On Unixish platforms, this is typically /etc/privoxy/
6028 The templates are basically normal HTML files, but with place-holders (called
6029 symbols or exports), which Privoxy fills at run time. It is possible to edit
6030 the templates with a normal text editor, should you want to customize them.
6031 (Not recommended for the casual user). Should you create your own custom
6032 templates, you should use the config setting templdir to specify an alternate
6033 location, so your templates do not get overwritten during upgrades.
6035 Note that just like in configuration files, lines starting with # are ignored
6036 when the templates are filled in.
6038 The place-holders are of the form @name@, and you will find a list of available
6039 symbols, which vary from template to template, in the comments at the start of
6040 each file. Note that these comments are not always accurate, and that it's
6041 probably best to look at the existing HTML code to find out which symbols are
6042 supported and what they are filled in with.
6044 A special application of this substitution mechanism is to make whole blocks of
6045 HTML code disappear when a specific symbol is set. We use this for many
6046 purposes, one of them being to include the beta warning in all our user
6047 interface (CGI) pages when Privoxy is in an alpha or beta development stage:
6049 <!-- @if-unstable-start -->
6051 ... beta warning HTML code goes here ...
6053 <!-- if-unstable-end@ -->
6056 If the "unstable" symbol is set, everything in between and including
6057 @if-unstable-start and if-unstable-end@ will disappear, leaving nothing but an
6063 There's also an if-then-else construct and an #include mechanism, but you'll
6064 sure find out if you are inclined to edit the templates ;-)
6066 All templates refer to a style located at http://config.privoxy.org/
6067 send-stylesheet. This is, of course, locally served by Privoxy and the source
6068 for it can be found and edited in the cgi-style.css template.
6070 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6072 11. Contacting the Developers, Bug Reporting and Feature Requests
6074 We value your feedback. In fact, we rely on it to improve Privoxy and its
6075 configuration. However, please note the following hints, so we can provide you
6076 with the best support:
6078 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6082 For casual users, our support forum at SourceForge is probably best suited:
6083 http://sourceforge.net/tracker/?group_id=11118&atid=211118
6085 All users are of course welcome to discuss their issues on the users mailing
6086 list, where the developers also hang around.
6088 Note that the Privoxy mailing lists are moderated. Posts from unsubscribed
6089 addresses have to be accepted manually by a moderator. This may cause a delay
6090 of several days and if you use a subject that doesn't clearly mention Privoxy
6091 or one of its features, your message may be accidentally discarded as spam.
6093 If you aren't subscribed, you should therefore spend a few seconds to come up
6094 with a proper subject. Additionally you should make it clear that you want to
6095 get CC'd. Otherwise some responses will be directed to the mailing list only,
6096 and you won't see them.
6098 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6100 11.2. Reporting Problems
6102 "Problems" for our purposes, come in two forms:
6104 • Configuration issues, such as ads that slip through, or sites that don't
6105 function properly due to one Privoxy "action" or another being turned "on".
6107 • "Bugs" in the programming code that makes up Privoxy, such as that might
6110 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6112 11.2.1. Reporting Ads or Other Configuration Problems
6114 Please send feedback on ads that slipped through, innocent images that were
6115 blocked, sites that don't work properly, and other configuration related
6116 problem of default.action file, to http://sourceforge.net/tracker/?group_id=
6117 11118&atid=460288, the Actions File Tracker.
6119 New, improved default.action files may occasionally be made available based on
6120 your feedback. These will be announced on the ijbswa-announce list and
6121 available from our the files section of our project page.
6123 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6125 11.2.2. Reporting Bugs
6127 Please report all bugs through our bug tracker: http://sourceforge.net/tracker
6128 /?group_id=11118&atid=111118.
6130 Before doing so, please make sure that the bug has not already been submitted
6131 and observe the additional hints at the top of the submit form. If already
6132 submitted, please feel free to add any info to the original report that might
6133 help to solve the issue.
6135 Please try to verify that it is a Privoxy bug, and not a browser or site bug or
6136 documented behaviour that just happens to be different than what you expected.
6137 If unsure, try toggling off Privoxy, and see if the problem persists.
6139 If you are using your own custom configuration, please try the stock configs to
6140 see if the problem is configuration related. If you're having problems with a
6141 feature that is disabled by default, please ask around on the mailing list if
6142 others can reproduce the problem.
6144 If you aren't using the latest Privoxy version, the bug may have been found and
6145 fixed in the meantime. We would appreciate if you could take the time to
6146 upgrade to the latest version (or even the latest CVS snapshot) and verify that
6147 your bug still exists.
6149 Please be sure to provide the following information:
6151 • The exact Privoxy version you are using (if you got the source from CVS,
6152 please also provide the source code revisions as shown in http://
6153 config.privoxy.org/show-version).
6155 • The operating system and versions you run Privoxy on, (e.g. Windows XP
6156 SP2), if you are using a Unix flavor, sending the output of "uname -a"
6157 should do, in case of GNU/Linux, please also name the distribution.
6159 • The name, platform, and version of the browser you were using (e.g.
6160 Internet Explorer v5.5 for Mac).
6162 • The URL where the problem occurred, or some way for us to duplicate the
6163 problem (e.g. http://somesite.example.com/?somethingelse=123).
6165 • Whether your version of Privoxy is one supplied by the Privoxy developers
6166 via SourceForge, or if you got your copy somewhere else.
6168 • Whether you are using Privoxy in tandem with another proxy such as Tor. If
6169 so, please temporary disable the other proxy to see if the symptoms change.
6171 • Whether you are using a personal firewall product. If so, does Privoxy work
6174 • Any other pertinent information to help identify the problem such as config
6175 or log file excerpts (yes, you should have log file entries for each action
6178 You don't have to tell us your actual name when filing a problem report, but
6179 please use a nickname so we can differentiate between your messages and the
6180 ones entered by other "anonymous" users that may respond to your request if
6181 they have the same problem or already found a solution.
6183 Please also check the status of your request a few days after submitting it, as
6184 we may request additional information. If you use a SF id, you should
6185 automatically get a mail when someone responds to your request.
6187 The appendix of the Privoxy User Manual also has helpful information on
6188 understanding actions, and action debugging.
6190 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6192 11.3. Request New Features
6194 You are welcome to submit ideas on new features or other proposals for
6195 improvement through our feature request tracker at http://sourceforge.net/
6196 tracker/?atid=361118&group_id=11118.
6198 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6202 For any other issues, feel free to use the mailing lists. Technically
6203 interested users and people who wish to contribute to the project are also
6204 welcome on the developers list! You can find an overview of all Privoxy-related
6205 mailing lists, including list archives, at: http://sourceforge.net/mail/?
6208 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6210 12. Privoxy Copyright, License and History
6212 Copyright 2001 - 2007 by Privoxy Developers <
6213 ijbswa-developers@lists.sourceforge.net>
6215 Some source code is based on code Copyright 1997 by Anonymous Coders and
6216 Junkbusters, Inc. and licensed under the GNU General Public License.
6218 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6222 Privoxy is free software; you can redistribute it and/or modify it under the
6223 terms of the GNU General Public License, version 2, as published by the Free
6224 Software Foundation.
6226 This program is distributed in the hope that it will be useful, but WITHOUT ANY
6227 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
6228 PARTICULAR PURPOSE. See the GNU General Public License for more details, which
6229 is available from the Free Software Foundation, Inc, 51 Franklin Street, Fifth
6230 Floor, Boston, MA 02110-1301, USA
6232 You should have received a copy of the GNU General Public License along with
6233 this program; if not, write to the
6236 Foundation, Inc. 51 Franklin Street, Fifth Floor
6237 Boston, MA 02110-1301
6240 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6244 A long time ago, there was the Internet Junkbuster, by Anonymous Coders and
6245 Junkbusters Corporation. This saved many users a lot of pain in the early days
6246 of web advertising and user tracking.
6248 But the web, its protocols and standards, and with it, the techniques for
6249 forcing ads on users, give up autonomy over their browsing, and for tracking
6250 them, keeps evolving. Unfortunately, the Internet Junkbuster did not. Version
6251 2.0.2, published in 1998, was (and is) the last official release available from
6252 Junkbusters Corporation. Fortunately, it had been released under the GNU GPL,
6253 which allowed further development by others.
6255 So Stefan Waldherr started maintaining an improved version of the software, to
6256 which eventually a number of people contributed patches. It could already
6257 replace banners with a transparent image, and had a first version of pop-up
6258 killing, but it was still very closely based on the original, with all its
6259 limitations, such as the lack of HTTP/1.1 support, flexible per-site
6260 configuration, or content modification. The last release from this effort was
6261 version 2.0.2-10, published in 2000.
6263 Then, some developers picked up the thread, and started turning the software
6264 inside out, upside down, and then reassembled it, adding many new features
6267 The result of this is Privoxy, whose first stable version, 3.0, was released
6270 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6274 Current Privoxy Team:
6276 Fabian Keil, lead developer
6277 David Schmidt, developer
6283 Former Privoxy Team Members:
6308 Thanks to the many people who have tested Privoxy, reported bugs, provided
6309 patches, made suggestions or contributed in some way. These include (in
6310 alphabetical order):
6366 Privoxy is based in part on code originally developed by Junkbusters Corp. and
6369 Privoxy heavily relies on Philip Hazel's PCRE.
6371 The code to filter compressed content makes use of zlib which is written by
6372 Jean-loup Gailly and Mark Adler.
6374 On systems that lack snprintf(), Privoxy is using a version written by Mark
6375 Martinec. On systems that lack strptime(), Privoxy is using the one from the
6376 GNU C Library written by Ulrich Drepper.
6378 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6382 Other references and sites of interest to Privoxy users:
6384 http://www.privoxy.org/, the Privoxy Home page.
6386 http://www.privoxy.org/faq/, the Privoxy FAQ.
6388 http://sourceforge.net/projects/ijbswa/, the Project Page for Privoxy on
6391 http://config.privoxy.org/, the web-based user interface. Privoxy must be
6392 running for this to work. Shortcut: http://p.p/
6394 http://sourceforge.net/tracker/?group_id=11118&atid=460288, to submit "misses"
6395 and other configuration related suggestions to the developers.
6397 http://www.junkbusters.com/ht/en/cookies.html, an explanation how cookies are
6398 used to track web users.
6400 http://www.junkbusters.com/ijb.html, the original Internet Junkbuster.
6402 http://privacy.net/, a useful site to check what information about you is
6403 leaked while you browse the web.
6405 http://www.squid-cache.org/, a popular caching proxy, which is often used
6406 together with Privoxy.
6408 http://www.pps.jussieu.fr/~jch/software/polipo/, Polipo is a caching proxy with
6409 advanced features like pipelining, multiplexing and caching of partial
6410 instances. In many setups it can be used as Squid replacement.
6412 http://tor.eff.org/, Tor can help anonymize web browsing, web publishing,
6413 instant messaging, IRC, SSH, and other applications.
6415 http://www.privoxy.org/developer-manual/, the Privoxy developer manual.
6417 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6421 14.1. Regular Expressions
6423 Privoxy uses Perl-style "regular expressions" in its actions files and filter
6424 file, through the PCRE and PCRS libraries.
6426 If you are reading this, you probably don't understand what "regular
6427 expressions" are, or what they can do. So this will be a very brief
6428 introduction only. A full explanation would require a book ;-)
6430 Regular expressions provide a language to describe patterns that can be run
6431 against strings of characters (letter, numbers, etc), to see if they match the
6432 string or not. The patterns are themselves (sometimes complex) strings of
6433 literal characters, combined with wild-cards, and other special characters,
6434 called meta-characters. The "meta-characters" have special meanings and are
6435 used to build complex patterns to be matched against. Perl Compatible Regular
6436 Expressions are an especially convenient "dialect" of the regular expression
6439 To make a simple analogy, we do something similar when we use wild-card
6440 characters when listing files with the dir command in DOS. *.* matches all
6441 filenames. The "special" character here is the asterisk which matches any and
6442 all characters. We can be more specific and use ? to match just individual
6443 characters. So "dir file?.text" would match "file1.txt", "file2.txt", etc. We
6444 are pattern matching, using a similar technique to "regular expressions"!
6446 Regular expressions do essentially the same thing, but are much, much more
6447 powerful. There are many more "special characters" and ways of building complex
6448 patterns however. Let's look at a few of the common ones, and then some
6451 . - Matches any single character, e.g. "a", "A", "4", ":", or "@".
6453 ? - The preceding character or expression is matched ZERO or ONE times. Either/
6456 + - The preceding character or expression is matched ONE or MORE times.
6458 * - The preceding character or expression is matched ZERO or MORE times.
6460 \ - The "escape" character denotes that the following character should be taken
6461 literally. This is used where one of the special characters (e.g. ".") needs to
6462 be taken literally and not as a special meta-character. Example: "example
6463 \.com", makes sure the period is recognized only as a period (and not expanded
6464 to its meta-character meaning of any single character).
6466 [ ] - Characters enclosed in brackets will be matched if any of the enclosed
6467 characters are encountered. For instance, "[0-9]" matches any numeric digit
6468 (zero through nine). As an example, we can combine this with "+" to match any
6469 digit one of more times: "[0-9]+".
6471 ( ) - parentheses are used to group a sub-expression, or multiple
6474 | - The "bar" character works like an "or" conditional statement. A match is
6475 successful if the sub-expression on either side of "|" matches. As an example:
6476 "/(this|that) example/" uses grouping and the bar character and would match
6477 either "this example" or "that example", and nothing else.
6479 These are just some of the ones you are likely to use when matching URLs with
6480 Privoxy, and is a long way from a definitive list. This is enough to get us
6481 started with a few simple examples which may be more illuminating:
6483 /.*/banners/.* - A simple example that uses the common combination of "." and
6484 "*" to denote any character, zero or more times. In other words, any string at
6485 all. So we start with a literal forward slash, then our regular expression
6486 pattern (".*") another literal forward slash, the string "banners", another
6487 forward slash, and lastly another ".*". We are building a directory path here.
6488 This will match any file with the path that has a directory named "banners" in
6489 it. The ".*" matches any characters, and this could conceivably be more forward
6490 slashes, so it might expand into a much longer looking path. For example, this
6491 could match: "/eye/hate/spammers/banners/annoy_me_please.gif", or just "/
6492 banners/annoying.html", or almost an infinite number of other possible
6493 combinations, just so it has "banners" in the path somewhere.
6495 And now something a little more complex:
6497 /.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward
6498 slashes again ("/"), so we are building another expression that is a file path
6499 statement. We have another ".*", so we are matching against any conceivable
6500 sub-path, just so it matches our expression. The only true literal that must
6501 match our pattern is adv, together with the forward slashes. What comes after
6502 the "adv" string is the interesting part.
6504 Remember the "?" means the preceding expression (either a literal character or
6505 anything grouped with "(...)" in this case) can exist or not, since this means
6506 either zero or one match. So "((er)?ts?|ertis(ing|ements?))" is optional, as
6507 are the individual sub-expressions: "(er)", "(ing|ements?)", and the "s". The "
6508 |" means "or". We have two of those. For instance, "(ing|ements?)", can expand
6509 to match either "ing" OR "ements?". What is being done here, is an attempt at
6510 matching as many variations of "advertisement", and similar, as possible. So
6511 this would expand to match just "adv", or "advert", or "adverts", or
6512 "advertising", or "advertisement", or "advertisements". You get the idea. But
6513 it would not match "advertizements" (with a "z"). We could fix that by changing
6514 our regular expression to: "/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/", which
6515 would then match either spelling.
6517 /.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward
6518 slashes. Anything in the square brackets "[ ]" can be matched. This is using
6519 "0-9" as a shorthand expression to mean any digit one through nine. It is the
6520 same as saying "0123456789". So any digit matches. The "+" means one or more of
6521 the preceding expression must be included. The preceding expression here is
6522 what is in the square brackets -- in this case, any digit one through nine.
6523 Then, at the end, we have a grouping: "(gif|jpe?g)". This includes a "|", so
6524 this needs to match the expression on either side of that bar character also. A
6525 simple "gif" on one side, and the other side will in turn match either "jpeg"
6526 or "jpg", since the "?" means the letter "e" is optional and can be matched
6527 once or not at all. So we are building an expression here to match image GIF or
6528 JPEG type image file. It must include the literal string "advert", then one or
6529 more digits, and a "." (which is now a literal, and not a special character,
6530 since it is escaped with "\"), and lastly either "gif", or "jpeg", or "jpg".
6531 Some possible matches would include: "//advert1.jpg", "/nasty/ads/
6532 advert1234.gif", "/banners/from/hell/advert99.jpg". It would not match
6533 "advert1.gif" (no leading slash), or "/adverts232.jpg" (the expression does not
6534 include an "s"), or "/advert1.jsp" ("jsp" is not in the expression anywhere).
6536 We are barely scratching the surface of regular expressions here so that you
6537 can understand the default Privoxy configuration files, and maybe use this
6538 knowledge to customize your own installation. There is much, much more that can
6539 be done with regular expressions. Now that you know enough to get started, you
6540 can learn more on your own :/
6542 More reading on Perl Compatible Regular expressions: http://perldoc.perl.org/
6545 For information on regular expression based substitutions and their
6546 applications in filters, please see the filter file tutorial in this manual.
6548 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6550 14.2. Privoxy's Internal Pages
6552 Since Privoxy proxies each requested web page, it is easy for Privoxy to trap
6553 certain special URLs. In this way, we can talk directly to Privoxy, and see how
6554 it is configured, see how our rules are being applied, change these rules and
6555 other configuration options, and even turn Privoxy's filtering off, all with a
6558 The URLs listed below are the special ones that allow direct access to Privoxy.
6559 Of course, Privoxy must be running to access these. If not, you will get a
6560 friendly error message. Internet access is not necessary either.
6562 • Privoxy main page:
6564 http://config.privoxy.org/
6566 There is a shortcut: http://p.p/ (But it doesn't provide a fall-back to a
6567 real page, in case the request is not sent through Privoxy)
6569 • Show information about the current configuration, including viewing and
6570 editing of actions files:
6572 http://config.privoxy.org/show-status
6574 • Show the source code version numbers:
6576 http://config.privoxy.org/show-version
6578 • Show the browser's request headers:
6580 http://config.privoxy.org/show-request
6582 • Show which actions apply to a URL and why:
6584 http://config.privoxy.org/show-url-info
6586 • Toggle Privoxy on or off. This feature can be turned off/on in the main
6587 config file. When toggled "off", "Privoxy" continues to run, but only as a
6588 pass-through proxy, with no actions taking place:
6590 http://config.privoxy.org/toggle
6592 Short cuts. Turn off, then on:
6594 http://config.privoxy.org/toggle?set=disable
6596 http://config.privoxy.org/toggle?set=enable
6598 These may be bookmarked for quick reference. See next.
6600 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6602 14.2.1. Bookmarklets
6604 Below are some "bookmarklets" to allow you to easily access a "mini" version of
6605 some of Privoxy's special pages. They are designed for MS Internet Explorer,
6606 but should work equally well in Netscape, Mozilla, and other browsers which
6607 support JavaScript. They are designed to run directly from your bookmarks - not
6608 by clicking the links below (although that should work for testing).
6610 To save them, right-click the link and choose "Add to Favorites" (IE) or "Add
6611 Bookmark" (Netscape). You will get a warning that the bookmark "may not be
6612 safe" - just click OK. Then you can run the Bookmarklet directly from your
6613 favorites/bookmarks. For even faster access, you can put them on the "Links"
6614 bar (IE) or the "Personal Toolbar" (Netscape), and run them with a single
6621 • Privoxy - Toggle Privoxy (Toggles between enabled and disabled)
6623 • Privoxy- View Status
6627 Credit: The site which gave us the general idea for these bookmarklets is
6628 www.bookmarklets.com. They have more information about bookmarklets.
6630 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6632 14.3. Chain of Events
6634 Let's take a quick look at how some of Privoxy's core features are triggered,
6635 and the ensuing sequence of events when a web page is requested by your
6638 • First, your web browser requests a web page. The browser knows to send the
6639 request to Privoxy, which will in turn, relay the request to the remote web
6640 server after passing the following tests:
6642 • Privoxy traps any request for its own internal CGI pages (e.g http://p.p/)
6643 and sends the CGI page back to the browser.
6645 • Next, Privoxy checks to see if the URL matches any "+block" patterns. If
6646 so, the URL is then blocked, and the remote web server will not be
6647 contacted. "+handle-as-image" and "+handle-as-empty-document" are then
6648 checked, and if there is no match, an HTML "BLOCKED" page is sent back to
6649 the browser. Otherwise, if it does match, an image is returned for the
6650 former, and an empty text document for the latter. The type of image would
6651 depend on the setting of "+set-image-blocker" (blank, checkerboard pattern,
6652 or an HTTP redirect to an image elsewhere).
6654 • Untrusted URLs are blocked. If URLs are being added to the trust file, then
6657 • If the URL pattern matches the "+fast-redirects" action, it is then
6658 processed. Unwanted parts of the requested URL are stripped.
6660 • Now the rest of the client browser's request headers are processed. If any
6661 of these match any of the relevant actions (e.g. "+hide-user-agent", etc.),
6662 headers are suppressed or forged as determined by these actions and their
6665 • Now the web server starts sending its response back (i.e. typically a web
6668 • First, the server headers are read and processed to determine, among other
6669 things, the MIME type (document type) and encoding. The headers are then
6670 filtered as determined by the "+crunch-incoming-cookies",
6671 "+session-cookies-only", and "+downgrade-http-version" actions.
6673 • If the "+kill-popups" action applies, and it is an HTML or JavaScript
6674 document, the popup-code in the response is filtered on-the-fly as it is
6677 • If any "+filter" action or "+deanimate-gifs" action applies (and the
6678 document type fits the action), the rest of the page is read into memory
6679 (up to a configurable limit). Then the filter rules (from default.filter
6680 and any other filter files) are processed against the buffered content.
6681 Filters are applied in the order they are specified in one of the filter
6682 files. Animated GIFs, if present, are reduced to either the first or last
6683 frame, depending on the action setting.The entire page, which is now
6684 filtered, is then sent by Privoxy back to your browser.
6686 If neither a "+filter" action or "+deanimate-gifs" matches, then Privoxy
6687 passes the raw data through to the client browser as it becomes available.
6689 • As the browser receives the now (possibly filtered) page content, it reads
6690 and then requests any URLs that may be embedded within the page source,
6691 e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
6692 frames), sounds, etc. For each of these objects, the browser issues a
6693 separate request (this is easily viewable in Privoxy's logs). And each such
6694 request is in turn processed just as above. Note that a complex web page
6695 will have many, many such embedded URLs. If these secondary requests are to
6696 a different server, then quite possibly a very differing set of actions is
6699 NOTE: This is somewhat of a simplistic overview of what happens with each URL
6700 request. For the sake of brevity and simplicity, we have focused on Privoxy's
6703 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
6705 14.4. Troubleshooting: Anatomy of an Action
6707 The way Privoxy applies actions and filters to any given URL can be complex,
6708 and not always so easy to understand what is happening. And sometimes we need
6709 to be able to see just what Privoxy is doing. Especially, if something Privoxy
6710 is doing is causing us a problem inadvertently. It can be a little daunting to
6711 look at the actions and filters files themselves, since they tend to be filled
6712 with regular expressions whose consequences are not always so obvious.
6714 One quick test to see if Privoxy is causing a problem or not, is to disable it
6715 temporarily. This should be the first troubleshooting step. See the
6716 Bookmarklets section on a quick and easy way to do this (be sure to flush
6717 caches afterward!). Looking at the logs is a good idea too. (Note that both the
6718 toggle feature and logging are enabled via config file settings, and may need
6721 Another easy troubleshooting step to try is if you have done any customization
6722 of your installation, revert back to the installed defaults and see if that
6723 helps. There are times the developers get complaints about one thing or
6724 another, and the problem is more related to a customized configuration issue.
6726 Privoxy also provides the http://config.privoxy.org/show-url-info page that can
6727 show us very specifically how actions are being applied to any given URL. This
6728 is a big help for troubleshooting.
6730 First, enter one URL (or partial URL) at the prompt, and then Privoxy will tell
6731 us how the current configuration will handle it. This will not help with
6732 filtering effects (i.e. the "+filter" action) from one of the filter files
6733 since this is handled very differently and not so easy to trap! It also will
6734 not tell you about any other URLs that may be embedded within the URL you are
6735 testing. For instance, images such as ads are expressed as URLs within the raw
6736 page source of HTML pages. So you will only get info for the actual URL that is
6737 pasted into the prompt area -- not any sub-URLs. If you want to know about
6738 embedded URLs like ads, you will have to dig those out of the HTML source. Use
6739 your browser's "View Page Source" option for this. Or right click on the ad,
6742 Let's try an example, google.com, and look at it one section at a time in a
6743 sample configuration (your real configuration may vary):
6745 Matches for http://www.google.com:
6747 In file: default.action [ View ] [ Edit ]
6749 {+deanimate-gifs {last}
6750 +fast-redirects {check-decoded-url}
6751 +filter {refresh-tags}
6752 +filter {img-reorder}
6753 +filter {banners-by-size}
6755 +filter {jumping-windows}
6756 +filter {ie-exploits}
6757 +hide-forwarded-for-headers
6758 +hide-from-header {block}
6759 +hide-referrer {forge}
6760 +session-cookies-only
6761 +set-image-blocker {pattern}
6764 { -session-cookies-only }
6770 In file: user.action [ View ] [ Edit ]
6771 (no matches in this file)
6774 This is telling us how we have defined our "actions", and which ones match for
6775 our test case, "google.com". Displayed is all the actions that are available to
6776 us. Remember, the + sign denotes "on". - denotes "off". So some are "on" here,
6777 but many are "off". Each example we try may provide a slightly different end
6778 result, depending on our configuration directives.
6780 The first listing is for our default.action file. The large, multi-line
6781 listing, is how the actions are set to match for all URLs, i.e. our default
6782 settings. If you look at your "actions" file, this would be the section just
6783 below the "aliases" section near the top. This will apply to all URLs as
6784 signified by the single forward slash at the end of the listing -- " / ".
6786 But we have defined additional actions that would be exceptions to these
6787 general rules, and then we list specific URLs (or patterns) that these
6788 exceptions would apply to. Last match wins. Just below this then are two
6789 explicit matches for ".google.com". The first is negating our previous cookie
6790 setting, which was for "+session-cookies-only" (i.e. not persistent). So we
6791 will allow persistent cookies for google, at least that is how it is in this
6792 example. The second turns off any "+fast-redirects" action, allowing this to
6793 take place unmolested. Note that there is a leading dot here -- ".google.com".
6794 This will match any hosts and sub-domains, in the google.com domain also, such
6795 as "www.google.com" or "mail.google.com". But it would not match
6796 "www.google.de"! So, apparently, we have these two actions defined as
6797 exceptions to the general rules at the top somewhere in the lower part of our
6798 default.action file, and "google.com" is referenced somewhere in these latter
6801 Then, for our user.action file, we again have no hits. So there is nothing
6802 google-specific that we might have added to our own, local configuration. If
6803 there was, those actions would over-rule any actions from previously processed
6804 files, such as default.action. user.action typically has the last word. This is
6805 the best place to put hard and fast exceptions,
6807 And finally we pull it all together in the bottom section and summarize how
6808 Privoxy is applying all its "actions" to "google.com":
6814 -client-header-filter{hide-tor-exit-notation}
6815 -content-type-overwrite
6816 -crunch-client-header
6817 -crunch-if-none-match
6818 -crunch-incoming-cookies
6819 -crunch-outgoing-cookies
6820 -crunch-server-header
6821 +deanimate-gifs {last}
6822 -downgrade-http-version
6825 -filter {content-cookies}
6826 -filter {all-popups}
6827 -filter {banners-by-link}
6828 -filter {tiny-textforms}
6829 -filter {frameset-borders}
6830 -filter {demoronizer}
6831 -filter {shockwave-flash}
6832 -filter {quicktime-kioskmode}
6834 -filter {crude-parental}
6835 -filter {site-specifics}
6836 -filter {js-annoyances}
6837 -filter {html-annoyances}
6838 +filter {refresh-tags}
6839 -filter {unsolicited-popups}
6840 +filter {img-reorder}
6841 +filter {banners-by-size}
6843 +filter {jumping-windows}
6844 +filter {ie-exploits}
6851 -handle-as-empty-document
6853 -hide-accept-language
6854 -hide-content-disposition
6855 +hide-forwarded-for-headers
6856 +hide-from-header {block}
6857 -hide-if-modified-since
6858 +hide-referrer {forge}
6863 -overwrite-last-modified
6864 -prevent-compression
6868 -server-header-filter{xml-to-html}
6869 -server-header-filter{html-to-xml}
6870 -session-cookies-only
6871 +set-image-blocker {pattern}
6872 -treat-forbidden-connects-like-blocks
6875 Notice the only difference here to the previous listing, is to "fast-redirects"
6876 and "session-cookies-only", which are activated specifically for this site in
6877 our configuration, and thus show in the "Final Results".
6879 Now another example, "ad.doubleclick.net":
6887 { +block +handle-as-image }
6888 .[a-vx-z]*.doubleclick.net
6891 We'll just show the interesting part here - the explicit matches. It is matched
6892 three different times. Two "+block" sections, and a "+block +handle-as-image",
6893 which is the expanded form of one of our aliases that had been defined as:
6894 "+block-as-image". ("Aliases" are defined in the first section of the actions
6895 file and typically used to combine more than one action.)
6897 Any one of these would have done the trick and blocked this as an unwanted
6898 image. This is unnecessarily redundant since the last case effectively would
6899 also cover the first. No point in taking chances with these guys though ;-)
6900 Note that if you want an ad or obnoxious URL to be invisible, it should be
6901 defined as "ad.doubleclick.net" is done here -- as both a "+block" and an
6902 "+handle-as-image". The custom alias "+block-as-image" just simplifies the
6903 process and make it more readable.
6905 One last example. Let's try "http://www.example.net/adsl/HOWTO/". This one is
6906 giving us problems. We are getting a blank page. Hmmm ...
6908 Matches for http://www.example.net/adsl/HOWTO/:
6910 In file: default.action [ View ] [ Edit ]
6914 -client-header-filter{hide-tor-exit-notation}
6915 -content-type-overwrite
6916 -crunch-client-header
6917 -crunch-if-none-match
6918 -crunch-incoming-cookies
6919 -crunch-outgoing-cookies
6920 -crunch-server-header
6922 -downgrade-http-version
6923 +fast-redirects {check-decoded-url}
6925 -filter {content-cookies}
6926 -filter {all-popups}
6927 -filter {banners-by-link}
6928 -filter {tiny-textforms}
6929 -filter {frameset-borders}
6930 -filter {demoronizer}
6931 -filter {shockwave-flash}
6932 -filter {quicktime-kioskmode}
6934 -filter {crude-parental}
6935 -filter {site-specifics}
6936 -filter {js-annoyances}
6937 -filter {html-annoyances}
6938 +filter {refresh-tags}
6939 -filter {unsolicited-popups}
6940 +filter {img-reorder}
6941 +filter {banners-by-size}
6943 +filter {jumping-windows}
6944 +filter {ie-exploits}
6951 -handle-as-empty-document
6953 -hide-accept-language
6954 -hide-content-disposition
6955 +hide-forwarded-for-headers
6956 +hide-from-header{block}
6957 +hide-referer{forge}
6961 -overwrite-last-modified
6962 +prevent-compression
6966 -server-header-filter{xml-to-html}
6967 -server-header-filter{html-to-xml}
6968 +session-cookies-only
6969 +set-image-blocker{blank}
6970 -treat-forbidden-connects-like-blocks }
6973 { +block +handle-as-image }
6977 Ooops, the "/adsl/" is matching "/ads" in our configuration! But we did not
6978 want this at all! Now we see why we get the blank page. It is actually
6979 triggering two different actions here, and the effects are aggregated so that
6980 the URL is blocked, and Privoxy is told to treat the block as if it were an
6981 image. But this is, of course, all wrong. We could now add a new action below
6982 this (or better in our own user.action file) that explicitly un blocks ( "
6983 {-block}") paths with "adsl" in them (remember, last match in the configuration
6984 wins). There are various ways to handle such exceptions. Example:
6990 Now the page displays ;-) Remember to flush your browser's caches when making
6991 these kinds of changes to your configuration to insure that you get a freshly
6992 delivered page! Or, try using Shift+Reload.
6994 But now what about a situation where we get no explicit matches like we did
6997 { +block +handle-as-image }
7001 That actually was very helpful and pointed us quickly to where the problem was.
7002 If you don't get this kind of match, then it means one of the default rules in
7003 the first section of default.action is causing the problem. This would require
7004 some guesswork, and maybe a little trial and error to isolate the offending
7005 rule. One likely cause would be one of the "+filter" actions. These tend to be
7006 harder to troubleshoot. Try adding the URL for the site to one of aliases that
7011 .worldpay.com # for quietpc.com
7017 "{ shop }" is an "alias" that expands to "{ -filter -session-cookies-only }".
7018 Or you could do your own exception to negate filtering:
7021 # Disable ALL filter actions for sites in this section
7027 This would turn off all filtering for these sites. This is best put in
7028 user.action, for local site exceptions. Note that when a simple domain pattern
7029 is used by itself (without the subsequent path portion), all sub-pages within
7030 that domain are included automatically in the scope of the action.
7032 Images that are inexplicably being blocked, may well be hitting the "+filter
7033 {banners-by-size}" rule, which assumes that images of certain sizes are ad
7034 banners (works well most of the time since these tend to be standardized).
7036 "{ fragile }" is an alias that disables most actions that are the most likely
7037 to cause trouble. This can be used as a last resort for problem sites.
7040 # Handle with care: easy to break
7045 Remember to flush caches! Note that the mail.google reference lacks the TLD
7046 portion (e.g. ".com"). This will effectively match any TLD with google in it,
7047 such as mail.google.de., just as an example.
7049 If this still does not work, you will have to go through the remaining actions
7050 one by one to find which one(s) is causing the problem.
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