1 Privoxy 3.0.0 User Manual
3 Copyright © 2001, 2002 by Privoxy Developers
5 $Id: user-manual.sgml,v 1.123.2.18 2002/08/22 23:47:58 hal9 Exp $
7 The User Manual gives users information on how to install, configure and use
10 Privoxy is a web proxy with advanced filtering capabilities for protecting
11 privacy, filtering web page content, managing cookies, controlling access, and
12 removing ads, banners, pop-ups and other obnoxious Internet junk. Privoxy has a
13 very flexible configuration and can be customized to suit individual needs and
14 tastes. Privoxy has application for both stand-alone systems and multi-user
17 Privoxy is based on Internet Junkbuster (tm).
19 You can find the latest version of the User Manual at http://www.privoxy.org/
20 user-manual/. Please see the Contact section on how to contact the developers.
22 -------------------------------------------------------------------------------
33 2.1.1. Red Hat, SuSE and Conectiva RPMs
36 2.1.4. Solaris, NetBSD, FreeBSD, HP-UX
42 2.2. Building from Source
43 2.3. Keeping your Installation Up-to-Date
46 4. Quickstart to Using Privoxy
48 4.1. Quickstart to Ad Blocking
52 5.1. Red Hat and Conectiva
56 5.5. Solaris, NetBSD, FreeBSD, HP-UX and others
61 5.10. Command Line Options
63 6. Privoxy Configuration
65 6.1. Controlling Privoxy with Your Web Browser
66 6.2. Configuration Files Overview
68 7. The Main Configuration File
70 7.1. Configuration and Log File Locations
80 7.2. Local Set-up Documentation
90 7.3.2. single-threaded
92 7.4. Access Control and Security
96 7.4.3. enable-remote-toggle
97 7.4.4. enable-edit-actions
98 7.4.5. ACLs: permit-access and deny-access
104 7.5.2. forward-socks4 and forward-socks4a
105 7.5.3. Advanced Forwarding Examples
107 7.6. Windows GUI Options
111 8.1. Finding the Right Mix
113 8.3. How Actions are Applied to URLs
116 8.4.1. The Domain Pattern
117 8.4.2. The Path Pattern
123 8.5.3. crunch-incoming-cookies
124 8.5.4. crunch-outgoing-cookies
125 8.5.5. deanimate-gifs
126 8.5.6. downgrade-http-version
127 8.5.7. fast-redirects
129 8.5.9. handle-as-image
130 8.5.10. hide-forwarded-for-headers
131 8.5.11. hide-from-header
132 8.5.12. hide-referrer
133 8.5.13. hide-user-agent
135 8.5.15. limit-connect
136 8.5.16. prevent-compression
137 8.5.17. send-vanilla-wafer
139 8.5.19. session-cookies-only
140 8.5.20. set-image-blocker
144 8.7. Actions Files Tutorial
146 8.7.1. default.action
151 9.1. Filter File Tutorial
154 11. Contacting the Developers, Bug Reporting and Feature Requests
158 11.3. Request New Features
159 11.4. Report Ads or Other Actions-Related Problems
162 12. Privoxy Copyright, License and History
171 14.1. Regular Expressions
172 14.2. Privoxy's Internal Pages
176 14.3. Chain of Events
177 14.4. Anatomy of an Action
181 This documentation is included with the current stable version of Privoxy,
184 -------------------------------------------------------------------------------
188 In addition to Internet Junkbuster's traditional features of ad and banner
189 blocking and cookie management, Privoxy provides new features:
191 * Integrated browser based configuration and control utility at http://
192 config.privoxy.org/ (shortcut: http://p.p/). Browser-based tracing of rule
193 and filter effects. Remote toggling.
195 * Web page content filtering (removes banners based on size, invisible
196 "web-bugs", JavaScript and HTML annoyances, pop-up windows, etc.)
198 * Modularized configuration that allows for standard settings and user
199 settings to reside in separate files, so that installing updated actions
200 files won't overwrite individual user settings.
202 * HTTP/1.1 compliant (but not all optional 1.1 features are supported).
204 * Support for Perl Compatible Regular Expressions in the configuration files,
205 and generally a more sophisticated and flexible configuration syntax over
208 * Improved cookie management features (e.g. session based cookies).
212 * Bypass many click-tracking scripts (avoids script redirection).
214 * Multi-threaded (POSIX and native threads).
216 * User-customizable HTML templates for all proxy-generated pages (e.g.
219 * Auto-detection and re-reading of config file changes.
221 * Improved signal handling, and a true daemon mode (Unix).
223 * Every feature now controllable on a per-site or per-location basis,
224 configuration more powerful and versatile over-all.
226 * Many smaller new features added, limitations and bugs removed, and security
229 -------------------------------------------------------------------------------
233 Privoxy is available both in convenient pre-compiled packages for a wide range
234 of operating systems, and as raw source code. For most users, we recommend
235 using the packages, which can be downloaded from our Privoxy Project Page.
237 Note: If you have a previous Junkbuster or Privoxy installation on your system,
238 you will need to remove it. On some platforms, this may be done for you as part
239 of their installation procedure. (See below for your platform). In any case be
240 sure to backup your old configuration if it is valuable to you. See the note to
241 upgraders section below.
243 -------------------------------------------------------------------------------
247 How to install the binary packages depends on your operating system:
249 -------------------------------------------------------------------------------
251 2.1.1. Red Hat, SuSE and Conectiva RPMs
253 RPMs can be installed with rpm -Uvh privoxy-3.0.0-1.rpm, and will use /etc/
254 privoxy for the location of configuration files.
256 Note that on Red Hat, Privoxy will not be automatically started on system boot.
257 You will need to enable that using chkconfig, ntsysv, or similar methods. Note
258 that SuSE will automatically start Privoxy in the boot process.
260 If you have problems with failed dependencies, try rebuilding the SRC RPM: rpm
261 --rebuild privoxy-3.0.0-1.src.rpm. This will use your locally installed
262 libraries and RPM version.
264 Also note that if you have a Junkbuster RPM installed on your system, you need
265 to remove it first, because the packages conflict. Otherwise, RPM will try to
266 remove Junkbuster automatically, before installing Privoxy.
268 -------------------------------------------------------------------------------
272 DEBs can be installed with dpkg -i privoxy_3.0.0-1.deb, and will use /etc/
273 privoxy for the location of configuration files.
275 -------------------------------------------------------------------------------
279 Just double-click the installer, which will guide you through the installation
280 process. You will find the configuration files in the same directory as you
281 installed Privoxy in. We do not use the registry of Windows.
283 -------------------------------------------------------------------------------
285 2.1.4. Solaris, NetBSD, FreeBSD, HP-UX
287 Create a new directory, cd to it, then unzip and untar the archive. For the
288 most part, you'll have to figure out where things go.
290 -------------------------------------------------------------------------------
294 First, make sure that no previous installations of Junkbuster and / or Privoxy
295 are left on your system. Check that no Junkbuster or Privoxy objects are in
298 Then, just double-click the WarpIN self-installing archive, which will guide
299 you through the installation process. A shadow of the Privoxy executable will
300 be placed in your startup folder so it will start automatically whenever OS/2
303 The directory you choose to install Privoxy into will contain all of the
306 -------------------------------------------------------------------------------
310 Unzip the downloaded file (you can either double-click on the file from the
311 finder, or from the desktop if you downloaded it there). Then, double-click on
312 the package installer icon named Privoxy.pkg and follow the installation
313 process. Privoxy will be installed in the folder /Library/Privoxy. It will
314 start automatically whenever you start up. To prevent it from starting
315 automatically, remove or rename the folder /Library/StartupItems/Privoxy.
317 To start Privoxy by hand, double-click on StartPrivoxy.command in the /Library/
318 Privoxy folder. Or, type this command in the Terminal:
320 /Library/Privoxy/StartPrivoxy.command
323 You will be prompted for the administrator password.
325 -------------------------------------------------------------------------------
329 Copy and then unpack the lha archive to a suitable location. All necessary
330 files will be installed into Privoxy directory, including all configuration and
331 log files. To uninstall, just remove this directory.
333 -------------------------------------------------------------------------------
337 Gentoo source packages (Ebuilds) for Privoxy are contained in the Gentoo
338 Portage Tree (they are not on the download page, but there is a Gentoo section,
339 where you can see when a new Privoxy Version is added to the Portage Tree).
341 Before installing Privoxy under Gentoo just do first emerge rsync to get the
342 latest changes from the Portage tree. With emerge privoxy you install the
345 Configuration files are in /etc/privoxy, the documentation is in /usr/share/doc
346 /privoxy-3.0.0 and the Log directory is in /var/log/privoxy.
348 -------------------------------------------------------------------------------
350 2.2. Building from Source
352 The most convenient way to obtain the Privoxy sources is to download the source
353 tarball from our project page.
355 If you like to live on the bleeding edge and are not afraid of using possibly
356 unstable development versions, you can check out the up-to-the-minute version
357 directly from the CVS repository or simply download the nightly CVS tarball.
359 To build Privoxy from source, autoconf, GNU make (gmake), and, of course, a C
360 compiler like gcc are required.
362 When building from a source tarball (either release version or nightly CVS
363 tarball), first unpack the source:
365 tar xzvf privoxy-3.0.0-src* [.tgz or .tar.gz]
368 For retrieving the current CVS sources, you'll need CVS installed. Note that
369 sources from CVS are development quality, and may not be stable, or well
370 tested. To download CVS source:
372 cvs -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa login
373 cvs -z3 -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa co current
376 This will create a directory named current/, which will contain the source
379 Then, in either case, to build from unpacked tarball or CVS source:
383 ./configure # (--help to see options)
384 make # (the make from gnu, gmake for *BSD)
386 make -n install # (to see where all the files will go)
387 make install # (to really install)
389 +-----------------------------------------------------------------------------+
391 |-----------------------------------------------------------------------------|
392 |The "make install" target is temporary quite broken! It is recommended to use|
393 |a binary package, or do a source build, and manually install the components. |
395 +-----------------------------------------------------------------------------+
397 If you have gnu make, you can have the first four steps automatically done for
402 in the freshly downloaded or unpacked source directory.
404 For more detailed instructions on how to build Redhat and SuSE RPMs, Windows
405 self-extracting installers, building on platforms with special requirements
406 etc, please consult the developer manual.
408 -------------------------------------------------------------------------------
410 2.3. Keeping your Installation Up-to-Date
412 As user feedback comes in and development continues, we will make updated
413 versions of both the main actions file (as a separate package) and the software
414 itself (including the actions file) available for download.
416 If you wish to receive an email notification whenever we release updates of
417 Privoxy or the actions file, subscribe to our announce mailing list,
418 ijbswa-announce@lists.sourceforge.net.
420 In order not to loose your personal changes and adjustments when updating to
421 the latest default.action file we strongly recommend that you use user.action
422 for your customization of Privoxy. See the Chapter on actions files for
425 -------------------------------------------------------------------------------
429 There are very significant changes from earlier Junkbuster versions to the
430 current Privoxy. The number, names, syntax, and purposes of configuration files
431 have substantially changed. Junkbuster 2.0.x configuration files will not
432 migrate, Junkbuster 2.9.x and Privoxy configurations will need to be ported.
433 The functionalities of the old blockfile, cookiefile and imagelist are now
434 combined into the "actions files". default.action, is the main actions file.
435 Local exceptions should best be put into user.action.
437 A "filter file" (typically default.filter) is new as of Privoxy 2.9.x, and
438 provides some of the new sophistication (explained below). config is much the
441 If upgrading from a 2.0.x version, you will have to use the new config files,
442 and possibly adapt any personal rules from your older files. When porting
443 personal rules over from the old blockfile to the new actions files, please
444 note that even the pattern syntax has changed. If upgrading from 2.9.x
445 development versions, it is still recommended to use the new configuration
448 A quick list of things to be aware of before upgrading:
450 * The default listening port is now 8118 due to a conflict with another
453 * Some installers may remove earlier versions completely. Save any important
456 * Privoxy is controllable with a web browser at the special URL: http://
457 config.privoxy.org/ (Shortcut: http://p.p/). Many aspects of configuration
458 can be done here, including temporarily disabling Privoxy.
460 * The primary configuration files for cookie management, ad and banner
461 blocking, and many other aspects of Privoxy configuration are the actions
462 files. It is strongly recommended to become familiar with the new actions
463 concept below, before modifying these files. Locally defined rules should
466 * Some installers may not automatically start Privoxy after installation.
468 -------------------------------------------------------------------------------
470 4. Quickstart to Using Privoxy
472 * If upgrading, from versions before 2.9.16, please back up any configuration
473 files. See the Note to Upgraders Section.
475 * Install Privoxy. See the Installation Section below for platform specific
478 * Advanced users and those who want to offer Privoxy service to more than
479 just their local machine should check the main config file, especially the
480 security-relevant options. These are off by default.
482 * Start Privoxy, if the installation program has not done this already (may
483 vary according to platform). See the section Starting Privoxy.
485 * Set your browser to use Privoxy as HTTP and HTTPS proxy by setting the
486 proxy configuration for address of 127.0.0.1 and port 8118. (Junkbuster and
487 earlier versions of Privoxy used port 8000.) See the section Starting
488 Privoxy below for more details on this.
490 * Flush your browser's disk and memory caches, to remove any cached ad
493 * A default installation should provide a reasonable starting point for most.
494 There will undoubtedly be occasions where you will want to adjust the
495 configuration, but that can be dealt with as the need arises. Little to no
496 initial configuration is required in most cases.
498 See the Configuration section for more configuration options, and how to
499 customize your installation.
501 * If you experience ads that slipped through, innocent images that are
502 blocked, or otherwise feel the need to fine-tune Privoxy's behaviour, take
503 a look at the actions files. As a quick start, you might find the richly
504 commented examples helpful. You can also view and edit the actions files
505 through the web-based user interface. The Appendix "Anatomy of an Action"
506 has hints how to debug actions that "misbehave".
508 * Please see the section Contacting the Developers on how to report bugs or
509 problems with websites or to get help.
511 * Now enjoy surfing with enhanced comfort and privacy!
513 -------------------------------------------------------------------------------
515 4.1. Quickstart to Ad Blocking
517 Ad blocking is but one of Privoxy's array of features. Many of these features
518 are for the technically minded advanced user. But, ad and banner blocking is
519 surely common ground for everybody.
521 This section will provide a quick summary of ad blocking so you can get up to
522 speed quickly without having to read the more extensive information provided
523 below, though this is highly recommended.
525 First a bit of a warning ... blocking ads is much like blocking SPAM: the more
526 aggressive you are about it, the more likely you are to block things that were
527 not intended. So there is a trade off here. If you want extreme ad free
528 browsing, be prepared to deal with more "problem" sites, and to spend more time
529 adjusting the configuration to solve these unintended consequences. In short,
530 there is not an easy way to eliminate all ads. Either take the easy way and
531 settle for most ads blocked with the default configuration, or jump in and
532 tweak it for your personal surfing habits and preferences.
534 Secondly, a brief explanation of Privoxy's "actions". "Actions" in this
535 context, are the directives we use to tell Privoxy to perform some task
536 relating to HTTP transactions (i.e. web browsing). We tell Privoxy to take some
537 "action". Each action has a unique name and function. While there are many
538 potential actions in Privoxy's arsenal, only a few are used for ad blocking.
539 Actions, and action configuration files, are explained in depth below.
541 Actions are specified in Privoxy's configuration, followed by one or more URLs
542 to which the action should apply. URLs can actually be URL type patterns that
543 use wildcards so they can apply potentially to a range of similar URLs. The
544 actions, together with the URL patterns are called a section.
546 When you connect to a website, the full URL will either match one or more of
547 the sections as defined in Privoxy's configuration, or not. If so, then Privoxy
548 will perform the respective actions. If not, then nothing special happens.
549 Furthermore, web pages may contain embedded, secondary URLs that your web
550 browser will use to load additional components of the page, as it parses the
551 original page's HTML content. An ad image for instance, is just an URL embedded
552 in the page somewhere. The image itself may be on the same server, or a server
553 somewhere else on the Internet. Complex web pages will have many such embedded
556 The actions we need to know about for ad blocking are: block, handle-as-image,
557 and set-image-blocker:
559 * block - this action stops any contact between your browser and any URL
560 patterns that match this action's configuration. It can be used for
561 blocking ads, but also anything that is determined to be unwanted. By
562 itself, it simply stops any communication with the remote server and sends
563 Privoxy's own built-in BLOCKED page instead to let you now what has
566 * handle-as-image - tells Privoxy to treat this URL as an image. Privoxy's
567 default configuration already does this for all common image types (e.g.
568 GIF), but there are many situations where this is not so easy to determine.
569 So we'll force it in these cases. This is particularly important for ad
570 blocking, since only if we know that it's an image of some kind, can we
571 replace it with an image of our choosing, instead of the Privoxy BLOCKED
572 page (which would only result in a "broken image" icon). There are some
573 limitations to this though. For instance, you can't just brute-force an
574 image substitution for an entire HTML page in most situations.
576 * set-image-blocker - tells Privoxy what to display in place of an ad image
577 that has hit a block rule. For this to come into play, the URL must match a
578 block action somewhere in the configuration, and, it must also match an
579 handle-as-image action.
581 The configuration options on what to display instead of the ad are:
583 pattern - a checkerboard pattern, so that an ad replacement is obvious.
586 blank - A very small empty GIF image is displayed. This is the so-called
587 "invisible" configuration option.
589 http://<URL> - A redirect to any image anywhere of the user's choosing
592 The quickest way to adjust any of these settings is with your browser through
593 the special Privoxy editor at http://config.privoxy.org/show-status (shortcut:
594 http://p.p/show-status). This is an internal page, and does not require
595 Internet access. Select the appropriate "actions" file, and click "Edit". It is
596 best to put personal or local preferences in user.action since this is not
597 meant to be overwritten during upgrades, and will over-ride the settings in
598 other files. Here you can insert new "actions", and URLs for ad blocking or
599 other purposes, and make other adjustments to the configuration. Privoxy will
600 detect these changes automatically.
602 A quick and simple step by step example:
604 * Right click on the ad image to be blocked, then select "Copy Link Location"
605 from the pop-up menu.
607 * Set your browser to http://config.privoxy.org/show-status
609 * Find user.action in the top section, and click on "Edit":
611 Figure 1. Actions Files in Use
615 * You should have a section with only block listed under "Actions:". If not,
616 click a "Insert new section below" button, and in the new section that just
617 appeared, click the Edit button right under the word "Actions:". This will
618 bring up a list of all actions. Find block near the top, and click in the
619 "Enabled" column, then "Submit" just below the list.
621 * Now, in the block actions section, click the "Add" button, and paste the
622 URL the browser got from "Copy Link Location". Remove the http:// at the
623 beginning of the URL. Then, click "Submit" (or "OK" if in a pop-up window).
625 * Now go back to the original page, and press SHIFT-Reload (or flush all
626 browser caches). The image should be gone now.
628 This is a very crude and simple example. There might be good reasons to use a
629 wildcard pattern match to include potentially similar images from the same
630 site. For a more extensive explanation of "patterns", and the entire actions
631 concept, see the Actions section.
633 For advanced users who want to hand edit their config files, you might want to
634 now go to the Actions Files Tutorial. The ideas explained therein also apply to
635 the web-based editor.
637 -------------------------------------------------------------------------------
641 Before launching Privoxy for the first time, you will want to configure your
642 browser(s) to use Privoxy as a HTTP and HTTPS proxy. The default is 127.0.0.1
643 (or localhost) for the proxy address, and port 8118 (earlier versions used port
644 8000). This is the one configuration step that must be done!
646 Please note that Privoxy can only proxy HTTP and HTTPS traffic. It will not
647 work with FTP or other protocols.
649 Figure 2. Proxy Configuration (Mozilla)
653 With Netscape (and Mozilla), this can be set under:
665 For Internet Explorer:
675 Then, check "Use Proxy" and fill in the appropriate info (Address: 127.0.0.1,
676 Port: 8118). Include HTTPS (SSL), if you want HTTPS proxy support too.
678 After doing this, flush your browser's disk and memory caches to force a
679 re-reading of all pages and to get rid of any ads that may be cached. You are
680 now ready to start enjoying the benefits of using Privoxy!
682 Privoxy is typically started by specifying the main configuration file to be
683 used on the command line. If no configuration file is specified on the command
684 line, Privoxy will look for a file named config in the current directory.
685 Except on Win32 where it will try config.txt.
687 -------------------------------------------------------------------------------
689 5.1. Red Hat and Conectiva
691 We use a script. Note that Red Hat does not start Privoxy upon booting per
692 default. It will use the file /etc/privoxy/config as its main configuration
695 # /etc/rc.d/init.d/privoxy start
697 -------------------------------------------------------------------------------
701 We use a script. Note that Debian starts Privoxy upon booting per default. It
702 will use the file /etc/privoxy/config as its main configuration file.
704 # /etc/init.d/privoxy start
706 -------------------------------------------------------------------------------
710 We use a script. It will use the file /etc/privoxy/config as its main
711 configuration file. Note that SuSE starts Privoxy upon booting your PC.
715 -------------------------------------------------------------------------------
719 Click on the Privoxy Icon to start Privoxy. If no configuration file is
720 specified on the command line, Privoxy will look for a file named config.txt.
721 Note that Windows will automatically start Privoxy upon booting you PC.
723 -------------------------------------------------------------------------------
725 5.5. Solaris, NetBSD, FreeBSD, HP-UX and others
727 Example Unix startup command:
729 # /usr/sbin/privoxy /etc/privoxy/config
731 -------------------------------------------------------------------------------
735 During installation, Privoxy is configured to start automatically when the
736 system restarts. You can start it manually by double-clicking on the Privoxy
737 icon in the Privoxy folder.
739 -------------------------------------------------------------------------------
743 During installation, Privoxy is configured to start automatically when the
744 system restarts. To start Privoxy by hand, double-click on the
745 StartPrivoxy.command icon in the /Library/Privoxy folder. Or, type this command
748 /Library/Privoxy/StartPrivoxy.command
751 You will be prompted for the administrator password.
753 -------------------------------------------------------------------------------
757 Start Privoxy (with RUN <>NIL:) in your startnet script (AmiTCP), in s:
758 user-startup (RoadShow), as startup program in your startup script (Genesis),
759 or as startup action (Miami and MiamiDx). Privoxy will automatically quit when
760 you quit your TCP/IP stack (just ignore the harmless warning your TCP/IP stack
761 may display that Privoxy is still running).
763 -------------------------------------------------------------------------------
767 A script is again used. It will use the file /etc/privoxy/config as its main
770 /etc/init.d/privoxy start
773 Note that Privoxy is not automatically started at boot time by default. You can
774 change this with the rc-update command.
776 rc-update add privoxy default
779 -------------------------------------------------------------------------------
781 5.10. Command Line Options
783 Privoxy may be invoked with the following command-line options:
787 Print version info and exit. Unix only.
791 Print short usage info and exit. Unix only.
795 Don't become a daemon, i.e. don't fork and become process group leader, and
796 don't detach from controlling tty. Unix only.
800 On startup, write the process ID to FILE. Delete the FILE on exit. Failure
801 to create or delete the FILE is non-fatal. If no FILE option is given, no
802 PID file will be used. Unix only.
804 * --user USER[.GROUP]
806 After (optionally) writing the PID file, assume the user ID of USER, and if
807 included the GID of GROUP. Exit if the privileges are not sufficient to do
812 If no configfile is included on the command line, Privoxy will look for a
813 file named "config" in the current directory (except on Win32 where it will
814 look for "config.txt" instead). Specify full path to avoid confusion. If no
815 config file is found, Privoxy will fail to start.
817 -------------------------------------------------------------------------------
819 6. Privoxy Configuration
821 All Privoxy configuration is stored in text files. These files can be edited
822 with a text editor. Many important aspects of Privoxy can also be controlled
823 easily with a web browser.
825 -------------------------------------------------------------------------------
827 6.1. Controlling Privoxy with Your Web Browser
829 Privoxy's user interface can be reached through the special URL http://
830 config.privoxy.org/ (shortcut: http://p.p/), which is a built-in page and works
831 without Internet access. You will see the following section:
834 ? View & change the current configuration
835 ? View the source code version numbers
836 ? View the request headers.
837 ? Look up which actions apply to a URL and why
838 ? Toggle Privoxy on or off
842 This should be self-explanatory. Note the first item leads to an editor for the
843 actions files, which is where the ad, banner, cookie, and URL blocking magic is
844 configured as well as other advanced features of Privoxy. This is an easy way
845 to adjust various aspects of Privoxy configuration. The actions file, and other
846 configuration files, are explained in detail below.
848 "Toggle Privoxy On or Off" is handy for sites that might have problems with
849 your current actions and filters. You can in fact use it as a test to see
850 whether it is Privoxy causing the problem or not. Privoxy continues to run as a
851 proxy in this case, but all manipulation is disabled, i.e. Privoxy acts like a
852 normal forwarding proxy. There is even a toggle Bookmarklet offered, so that
853 you can toggle Privoxy with one click from your browser.
855 -------------------------------------------------------------------------------
857 6.2. Configuration Files Overview
859 For Unix, *BSD and Linux, all configuration files are located in /etc/privoxy/
860 by default. For MS Windows, OS/2, and AmigaOS these are all in the same
861 directory as the Privoxy executable.
863 The installed defaults provide a reasonable starting point, though some
864 settings may be aggressive by some standards. For the time being, the principle
865 configuration files are:
867 * The main configuration file is named config on Linux, Unix, BSD, OS/2, and
868 AmigaOS and config.txt on Windows. This is a required file.
870 * default.action (the main actions file) is used to define which "actions"
871 relating to banner-blocking, images, pop-ups, content modification, cookie
872 handling etc should be applied by default. It also defines many exceptions
873 (both positive and negative) from this default set of actions that enable
874 Privoxy to selectively eliminate the junk, and only the junk, on as many
875 websites as possible.
877 Multiple actions files may be defined in config. These are processed in the
878 order they are defined. Local customizations and locally preferred
879 exceptions to the default policies as defined in default.action (which you
880 will most probably want to define sooner or later) are probably best
881 applied in user.action, where you can preserve them across upgrades.
882 standard.action is for Privoxy's internal use.
884 There is also a web based editor that can be accessed from http://
885 config.privoxy.org/show-status (Shortcut: http://p.p/show-status) for the
886 various actions files.
888 * default.filter (the filter file) can be used to re-write the raw page
889 content, including viewable text as well as embedded HTML and JavaScript,
890 and whatever else lurks on any given web page. The filtering jobs are only
891 pre-defined here; whether to apply them or not is up to the actions files.
893 All files use the "#" character to denote a comment (the rest of the line will
894 be ignored) and understand line continuation through placing a backslash ("\")
895 as the very last character in a line. If the # is preceded by a backslash, it
896 looses its special function. Placing a # in front of an otherwise valid
897 configuration line to prevent it from being interpreted is called "commenting
900 The actions files and default.filter can use Perl style regular expressions for
903 After making any changes, there is no need to restart Privoxy in order for the
904 changes to take effect. Privoxy detects such changes automatically. Note,
905 however, that it may take one or two additional requests for the change to take
906 effect. When changing the listening address of Privoxy, these "wake up"
907 requests must obviously be sent to the old listening address.
909 -------------------------------------------------------------------------------
911 7. The Main Configuration File
913 Again, the main configuration file is named config on Linux/Unix/BSD and OS/2,
914 and config.txt on Windows. Configuration lines consist of an initial keyword
915 followed by a list of values, all separated by whitespace (any number of spaces
916 or tabs). For example:
920 Assigns the value /etc/privoxy to the option confdir and thus indicates that
921 the configuration directory is named "/etc/privoxy/".
923 All options in the config file except for confdir and logdir are optional.
924 Watch out in the below description for what happens if you leave them unset.
926 The main config file controls all aspects of Privoxy's operation that are not
927 location dependent (i.e. they apply universally, no matter where you may be
930 -------------------------------------------------------------------------------
932 7.1. Configuration and Log File Locations
934 Privoxy can (and normally does) use a number of other files for additional
935 configuration, help and logging. This section of the configuration file tells
936 Privoxy where to find those other files.
938 The user running Privoxy, must have read permission for all configuration
939 files, and write permission to any files that would be modified, such as log
940 files and actions files.
942 -------------------------------------------------------------------------------
948 The directory where the other configuration files are located
956 /etc/privoxy (Unix) or Privoxy installation dir (Windows)
964 No trailing "/", please
966 When development goes modular and multi-user, the blocker, filter, and
967 per-user config will be stored in subdirectories of "confdir". For now, the
968 configuration directory structure is flat, except for confdir/templates,
969 where the HTML templates for CGI output reside (e.g. Privoxy's 404 error
972 -------------------------------------------------------------------------------
978 The directory where all logging takes place (i.e. where logfile and jarfile
987 /var/log/privoxy (Unix) or Privoxy installation dir (Windows)
995 No trailing "/", please
997 -------------------------------------------------------------------------------
1003 The actions file(s) to use
1007 File name, relative to confdir, without the .action suffix
1011 standard # Internal purposes, no editing recommended
1013 default # Main actions file
1015 user # User customizations
1019 No actions are taken at all. Simple neutral proxying.
1023 Multiple actionsfile lines are permitted, and are in fact recommended!
1025 The default values include standard.action, which is used for internal
1026 purposes and should be loaded, default.action, which is the "main" actions
1027 file maintained by the developers, and user.action, where you can make your
1030 Actions files are where all the per site and per URL configuration is done
1031 for ad blocking, cookie management, privacy considerations, etc. There is
1032 no point in using Privoxy without at least one actions file.
1034 -------------------------------------------------------------------------------
1040 The filter file to use
1044 File name, relative to confdir
1048 default.filter (Unix) or default.filter.txt (Windows)
1052 No textual content filtering takes place, i.e. all +filter{name} actions in
1053 the actions files are turned neutral.
1057 The filter file contains content modification rules that use regular
1058 expressions. These rules permit powerful changes on the content of Web
1059 pages, e.g., you could disable your favorite JavaScript annoyances,
1060 re-write the actual displayed text, or just have some fun replacing
1061 "Microsoft" with "MicroSuck" wherever it appears on a Web page.
1063 The +filter{name} actions rely on the relevant filter (name) to be defined
1066 A pre-defined filter file called default.filter that contains a bunch of
1067 handy filters for common problems is included in the distribution. See the
1068 section on the filter action for a list.
1070 -------------------------------------------------------------------------------
1080 File name, relative to logdir
1084 logfile (Unix) or privoxy.log (Windows)
1088 No log file is used, all log messages go to the console (STDERR).
1092 The windows version will additionally log to the console.
1094 The logfile is where all logging and error messages are written. The level
1095 of detail and number of messages are set with the debug option (see below).
1096 The logfile can be useful for tracking down a problem with Privoxy (e.g.,
1097 it's not blocking an ad you think it should block) but in most cases you
1098 probably will never look at it.
1100 Your logfile will grow indefinitely, and you will probably want to
1101 periodically remove it. On Unix systems, you can do this with a cron job
1102 (see "man cron"). For Red Hat, a logrotate script has been included.
1104 On SuSE Linux systems, you can place a line like "/var/log/privoxy.* +1024k
1105 644 nobody.nogroup" in /etc/logfiles, with the effect that cron.daily will
1106 automatically archive, gzip, and empty the log, when it exceeds 1M size.
1108 Any log files must be writable by whatever user Privoxy is being run as
1109 (default on UNIX, user id is "privoxy").
1111 -------------------------------------------------------------------------------
1117 The file to store intercepted cookies in
1121 File name, relative to logdir
1125 jarfile (Unix) or privoxy.jar (Windows)
1129 Intercepted cookies are not stored at all.
1133 The jarfile may grow to ridiculous sizes over time.
1135 -------------------------------------------------------------------------------
1141 The trust file to use
1145 File name, relative to confdir
1149 Unset (commented out). When activated: trust (Unix) or trust.txt (Windows)
1153 The whole trust mechanism is turned off.
1157 The trust mechanism is an experimental feature for building white-lists and
1158 should be used with care. It is NOT recommended for the casual user.
1160 If you specify a trust file, Privoxy will only allow access to sites that
1161 are named in the trustfile. You can also mark sites as trusted referrers
1162 (with +), with the effect that access to untrusted sites will be granted,
1163 if a link from a trusted referrer was used. The link target will then be
1164 added to the "trustfile". Possible applications include limiting Internet
1165 access for children.
1167 If you use + operator in the trust file, it may grow considerably over
1170 -------------------------------------------------------------------------------
1172 7.2. Local Set-up Documentation
1174 If you intend to operate Privoxy for more users than just yourself, it might be
1175 a good idea to let them know how to reach you, what you block and why you do
1176 that, your policies, etc.
1178 -------------------------------------------------------------------------------
1184 Location of the Privoxy User Manual.
1188 A fully qualified URI
1196 http://www.privoxy.org/version/user-manual/ will be used, where version is
1197 the Privoxy version.
1201 The User Manual URI is used for help links from some of the internal CGI
1202 pages. The manual itself is normally packaged with the binary
1203 distributions, so you probably want to set this to a locally installed
1204 copy. For multi-user setups, you could provide a copy on a local webserver
1205 for all your users and use the corresponding URL here.
1209 Unix, in local filesystem:
1211 user-manual file:///usr/share/doc/privoxy-3.0.0/user-manual/
1213 Any platform, on local webserver (called "local-webserver"):
1215 user-manual http://local-webserver/privoxy-user-manual/
1217 +-----------------------------------------------------------------+
1219 |-----------------------------------------------------------------|
1220 |If set, this option should be the first option in the config |
1221 |file, because it is used while the config file is being read. |
1222 +-----------------------------------------------------------------+
1224 -------------------------------------------------------------------------------
1226 7.2.2. trust-info-url
1230 A URL to be displayed in the error page that users will see if access to an
1231 untrusted page is denied.
1239 Two example URL are provided
1243 No links are displayed on the "untrusted" error page.
1247 The value of this option only matters if the experimental trust mechanism
1248 has been activated. (See trustfile above.)
1250 If you use the trust mechanism, it is a good idea to write up some on-line
1251 documentation about your trust policy and to specify the URL(s) here. Use
1252 multiple times for multiple URLs.
1254 The URL(s) should be added to the trustfile as well, so users don't end up
1255 locked out from the information on why they were locked out in the first
1258 -------------------------------------------------------------------------------
1260 7.2.3. admin-address
1264 An email address to reach the proxy administrator.
1276 No email address is displayed on error pages and the CGI user interface.
1280 If both admin-address and proxy-info-url are unset, the whole "Local
1281 Privoxy Support" box on all generated pages will not be shown.
1283 -------------------------------------------------------------------------------
1285 7.2.4. proxy-info-url
1289 A URL to documentation about the local Privoxy setup, configuration or
1302 No link to local documentation is displayed on error pages and the CGI user
1307 If both admin-address and proxy-info-url are unset, the whole "Local
1308 Privoxy Support" box on all generated pages will not be shown.
1310 This URL shouldn't be blocked ;-)
1312 -------------------------------------------------------------------------------
1316 These options are mainly useful when tracing a problem. Note that you might
1317 also want to invoke Privoxy with the --no-daemon command line option when
1320 -------------------------------------------------------------------------------
1326 Key values that determine what information gets logged to the logfile.
1334 12289 (i.e.: URLs plus informational and warning messages)
1338 Nothing gets logged.
1342 The available debug levels are:
1344 debug 1 # show each GET/POST/CONNECT request
1345 debug 2 # show each connection status
1346 debug 4 # show I/O status
1347 debug 8 # show header parsing
1348 debug 16 # log all data into the logfile
1349 debug 32 # debug force feature
1350 debug 64 # debug regular expression filter
1351 debug 128 # debug fast redirects
1352 debug 256 # debug GIF de-animation
1353 debug 512 # Common Log Format
1354 debug 1024 # debug kill pop-ups
1355 debug 2048 # CGI user interface
1356 debug 4096 # Startup banner and warnings.
1357 debug 8192 # Non-fatal errors
1359 To select multiple debug levels, you can either add them or use multiple
1362 A debug level of 1 is informative because it will show you each request as
1363 it happens. 1, 4096 and 8192 are highly recommended so that you will notice
1364 when things go wrong. The other levels are probably only of interest if you
1365 are hunting down a specific problem. They can produce a hell of an output
1368 The reporting of fatal errors (i.e. ones which crash Privoxy) is always on
1369 and cannot be disabled.
1371 If you want to use CLF (Common Log Format), you should set "debug 512" ONLY
1372 and not enable anything else.
1374 -------------------------------------------------------------------------------
1376 7.3.2. single-threaded
1380 Whether to run only one server thread
1392 Multi-threaded (or, where unavailable: forked) operation, i.e. the ability
1393 to serve multiple requests simultaneously.
1397 This option is only there for debug purposes and you should never need to
1398 use it. It will drastically reduce performance.
1400 -------------------------------------------------------------------------------
1402 7.4. Access Control and Security
1404 This section of the config file controls the security-relevant aspects of
1405 Privoxy's configuration.
1407 -------------------------------------------------------------------------------
1409 7.4.1. listen-address
1413 The IP address and TCP port on which Privoxy will listen for client
1426 Bind to 127.0.0.1 (localhost), port 8118. This is suitable and recommended
1427 for home users who run Privoxy on the same machine as their browser.
1431 You will need to configure your browser(s) to this proxy address and port.
1433 If you already have another service running on port 8118, or if you want to
1434 serve requests from other machines (e.g. on your local network) as well,
1435 you will need to override the default.
1437 If you leave out the IP address, Privoxy will bind to all interfaces
1438 (addresses) on your machine and may become reachable from the Internet. In
1439 that case, consider using access control lists (ACL's, see below), and/or a
1442 If you open Privoxy to untrusted users, you will also want to turn off the
1443 enable-edit-actions and enable-remote-toggle options!
1447 Suppose you are running Privoxy on a machine which has the address
1448 192.168.0.1 on your local private network (192.168.0.0) and has another
1449 outside connection with a different address. You want it to serve requests
1452 listen-address 192.168.0.1:8118
1454 -------------------------------------------------------------------------------
1460 Initial state of "toggle" status
1472 Act as if toggled on
1476 If set to 0, Privoxy will start in "toggled off" mode, i.e. behave like a
1477 normal, content-neutral proxy where all ad blocking, filtering, etc are
1478 disabled. See enable-remote-toggle below. This is not really useful
1479 anymore, since toggling is much easier via the web interface than via
1480 editing the conf file.
1482 The windows version will only display the toggle icon in the system tray if
1483 this option is present.
1485 -------------------------------------------------------------------------------
1487 7.4.3. enable-remote-toggle
1491 Whether or not the web-based toggle feature may be used
1503 The web-based toggle feature is disabled.
1507 When toggled off, Privoxy acts like a normal, content-neutral proxy, i.e.
1508 it acts as if none of the actions applied to any URL.
1510 For the time being, access to the toggle feature can not be controlled
1511 separately by "ACLs" or HTTP authentication, so that everybody who can
1512 access Privoxy (see "ACLs" and listen-address above) can toggle it for all
1513 users. So this option is not recommended for multi-user environments with
1516 Note that you must have compiled Privoxy with support for this feature,
1517 otherwise this option has no effect.
1519 -------------------------------------------------------------------------------
1521 7.4.4. enable-edit-actions
1525 Whether or not the web-based actions file editor may be used
1537 The web-based actions file editor is disabled.
1541 For the time being, access to the editor can not be controlled separately
1542 by "ACLs" or HTTP authentication, so that everybody who can access Privoxy
1543 (see "ACLs" and listen-address above) can modify its configuration for all
1544 users. So this option is not recommended for multi-user environments with
1547 Note that you must have compiled Privoxy with support for this feature,
1548 otherwise this option has no effect.
1550 -------------------------------------------------------------------------------
1552 7.4.5. ACLs: permit-access and deny-access
1556 Who can access what.
1560 src_addr[/src_masklen] [dst_addr[/dst_masklen]]
1562 Where src_addr and dst_addr are IP addresses in dotted decimal notation or
1563 valid DNS names, and src_masklen and dst_masklen are subnet masks in CIDR
1564 notation, i.e. integer values from 2 to 30 representing the length (in
1565 bits) of the network address. The masks and the whole destination part are
1574 Don't restrict access further than implied by listen-address
1578 Access controls are included at the request of ISPs and systems
1579 administrators, and are not usually needed by individual users. For a
1580 typical home user, it will normally suffice to ensure that Privoxy only
1581 listens on the localhost (127.0.0.1) or internal (home) network address by
1582 means of the listen-address option.
1584 Please see the warnings in the FAQ that this proxy is not intended to be a
1585 substitute for a firewall or to encourage anyone to defer addressing basic
1586 security weaknesses.
1588 Multiple ACL lines are OK. If any ACLs are specified, then the Privoxy
1589 talks only to IP addresses that match at least one permit-access line and
1590 don't match any subsequent deny-access line. In other words, the last match
1591 wins, with the default being deny-access.
1593 If Privoxy is using a forwarder (see forward below) for a particular
1594 destination URL, the dst_addr that is examined is the address of the
1595 forwarder and NOT the address of the ultimate target. This is necessary
1596 because it may be impossible for the local Privoxy to determine the IP
1597 address of the ultimate target (that's often what gateways are used for).
1599 You should prefer using IP addresses over DNS names, because the address
1600 lookups take time. All DNS names must resolve! You can not use domain
1601 patterns like "*.org" or partial domain names. If a DNS name resolves to
1602 multiple IP addresses, only the first one is used.
1604 Denying access to particular sites by ACL may have undesired side effects
1605 if the site in question is hosted on a machine which also hosts other
1610 Explicitly define the default behavior if no ACL and listen-address are
1611 set: "localhost" is OK. The absence of a dst_addr implies that all
1612 destination addresses are OK:
1614 permit-access localhost
1616 Allow any host on the same class C subnet as www.privoxy.org access to
1617 nothing but www.example.com:
1619 permit-access www.privoxy.org/24 www.example.com/32
1621 Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere,
1622 with the exception that 192.168.45.73 may not access
1623 www.dirty-stuff.example.com:
1625 permit-access 192.168.45.64/26
1626 deny-access 192.168.45.73 www.dirty-stuff.example.com
1628 -------------------------------------------------------------------------------
1634 Maximum size of the buffer for content filtering.
1646 Use a 4MB (4096 KB) limit.
1650 For content filtering, i.e. the +filter and +deanimate-gif actions, it is
1651 necessary that Privoxy buffers the entire document body. This can be
1652 potentially dangerous, since a server could just keep sending data
1653 indefinitely and wait for your RAM to exhaust -- with nasty consequences.
1656 When a document buffer size reaches the buffer-limit, it is flushed to the
1657 client unfiltered and no further attempt to filter the rest of the document
1658 is made. Remember that there may be multiple threads running, which might
1659 require up to buffer-limit Kbytes each, unless you have enabled
1660 "single-threaded" above.
1662 -------------------------------------------------------------------------------
1666 This feature allows routing of HTTP requests through a chain of multiple
1667 proxies. It can be used to better protect privacy and confidentiality when
1668 accessing specific domains by routing requests to those domains through an
1669 anonymous public proxy (see e.g. http://www.multiproxy.org/anon_list.htm) Or to
1670 use a caching proxy to speed up browsing. Or chaining to a parent proxy may be
1671 necessary because the machine that Privoxy runs on has no direct Internet
1674 Also specified here are SOCKS proxies. Privoxy supports the SOCKS 4 and SOCKS
1677 -------------------------------------------------------------------------------
1683 To which parent HTTP proxy specific requests should be routed.
1687 target_pattern http_parent[:port]
1689 where target_pattern is a URL pattern that specifies to which requests
1690 (i.e. URLs) this forward rule shall apply. Use / to denote "all URLs".
1691 http_parent[:port] is the DNS name or IP address of the parent HTTP proxy
1692 through which the requests should be forwarded, optionally followed by its
1693 listening port (default: 8080). Use a single dot (.) to denote "no
1702 Don't use parent HTTP proxies.
1706 If http_parent is ".", then requests are not forwarded to another HTTP
1707 proxy but are made directly to the web servers.
1709 Multiple lines are OK, they are checked in sequence, and the last match
1714 Everything goes to an example anonymizing proxy, except SSL on port 443
1715 (which it doesn't handle):
1717 forward / anon-proxy.example.org:8080
1720 Everything goes to our example ISP's caching proxy, except for requests to
1723 forward / caching-proxy.example-isp.net:8000
1724 forward .example-isp.net .
1726 -------------------------------------------------------------------------------
1728 7.5.2. forward-socks4 and forward-socks4a
1732 Through which SOCKS proxy (and to which parent HTTP proxy) specific
1733 requests should be routed.
1737 target_pattern socks_proxy[:port] http_parent[:port]
1739 where target_pattern is a URL pattern that specifies to which requests
1740 (i.e. URLs) this forward rule shall apply. Use / to denote "all URLs".
1741 http_parent and socks_proxy are IP addresses in dotted decimal notation or
1742 valid DNS names (http_parent may be "." to denote "no HTTP forwarding"),
1743 and the optional port parameters are TCP ports, i.e. integer values from 1
1752 Don't use SOCKS proxies.
1756 Multiple lines are OK, they are checked in sequence, and the last match
1759 The difference between forward-socks4 and forward-socks4a is that in the
1760 SOCKS 4A protocol, the DNS resolution of the target hostname happens on the
1761 SOCKS server, while in SOCKS 4 it happens locally.
1763 If http_parent is ".", then requests are not forwarded to another HTTP
1764 proxy but are made (HTTP-wise) directly to the web servers, albeit through
1769 From the company example.com, direct connections are made to all "internal"
1770 domains, but everything outbound goes through their ISP's proxy by way of
1771 example.com's corporate SOCKS 4A gateway to the Internet.
1773 forward-socks4a / socks-gw.example.com:1080 www-cache.example-isp.net:8080
1774 forward .example.com .
1776 A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent
1779 forward-socks4 / socks-gw.example.com:1080 .
1781 -------------------------------------------------------------------------------
1783 7.5.3. Advanced Forwarding Examples
1785 If you have links to multiple ISPs that provide various special content only to
1786 their subscribers, you can configure multiple Privoxies which have connections
1787 to the respective ISPs to act as forwarders to each other, so that your users
1788 can see the internal content of all ISPs.
1790 Assume that host-a has a PPP connection to isp-a.net. And host-b has a PPP
1791 connection to isp-b.net. Both run Privoxy. Their forwarding configuration can
1797 forward .isp-b.net host-b:8118
1802 forward .isp-a.net host-a:8118
1804 Now, your users can set their browser's proxy to use either host-a or host-b
1805 and be able to browse the internal content of both isp-a and isp-b.
1807 If you intend to chain Privoxy and squid locally, then chain as browser ->
1808 squid -> privoxy is the recommended way.
1810 Assuming that Privoxy and squid run on the same box, your squid configuration
1811 could then look like this:
1813 # Define Privoxy as parent proxy (without ICP)
1814 cache_peer 127.0.0.1 parent 8118 7 no-query
1816 # Define ACL for protocol FTP
1819 # Do not forward FTP requests to Privoxy
1820 always_direct allow ftp
1822 # Forward all the rest to Privoxy
1823 never_direct allow all
1825 You would then need to change your browser's proxy settings to squid's address
1826 and port. Squid normally uses port 3128. If unsure consult http_port in
1829 You could just as well decide to only forward requests for Windows executables
1830 through a virus-scanning parent proxy, say, on antivir.example.com, port 8010:
1833 forward /.*\.(exe|com|dll|zip)$ antivir.example.com:8010
1835 -------------------------------------------------------------------------------
1837 7.6. Windows GUI Options
1839 Privoxy has a number of options specific to the Windows GUI interface:
1841 If "activity-animation" is set to 1, the Privoxy icon will animate when
1842 "Privoxy" is active. To turn off, set to 0.
1844 activity-animation 1
1847 If "log-messages" is set to 1, Privoxy will log messages to the console window:
1852 If "log-buffer-size" is set to 1, the size of the log buffer, i.e. the amount
1853 of memory used for the log messages displayed in the console window, will be
1854 limited to "log-max-lines" (see below).
1856 Warning: Setting this to 0 will result in the buffer to grow infinitely and eat
1862 log-max-lines is the maximum number of lines held in the log buffer. See above.
1867 If "log-highlight-messages" is set to 1, Privoxy will highlight portions of the
1868 log messages with a bold-faced font:
1870 log-highlight-messages 1
1873 The font used in the console window:
1875 log-font-name Comic Sans MS
1878 Font size used in the console window:
1883 "show-on-task-bar" controls whether or not Privoxy will appear as a button on
1884 the Task bar when minimized:
1889 If "close-button-minimizes" is set to 1, the Windows close button will minimize
1890 Privoxy instead of closing the program (close with the exit option on the File
1893 close-button-minimizes 1
1896 The "hide-console" option is specific to the MS-Win console version of Privoxy.
1897 If this option is used, Privoxy will disconnect from and hide the command
1903 -------------------------------------------------------------------------------
1907 The actions files are used to define what actions Privoxy takes for which URLs,
1908 and thus determine how ad images, cookies and various other aspects of HTTP
1909 content and transactions are handled, and on which sites (or even parts
1910 thereof). There are three such files included with Privoxy (as of version
1911 2.9.15), with differing purposes:
1913 * default.action - is the primary action file that sets the initial values
1914 for all actions. It is intended to provide a base level of functionality
1915 for Privoxy's array of features. So it is a set of broad rules that should
1916 work reasonably well for users everywhere. This is the file that the
1917 developers are keeping updated, and making available to users.
1919 * user.action - is intended to be for local site preferences and exceptions.
1920 As an example, if your ISP or your bank has specific requirements, and need
1921 special handling, this kind of thing should go here. This file will not be
1924 * standard.action - is used by the web based editor, to set various
1925 pre-defined sets of rules for the default actions section in
1926 default.action. These have increasing levels of aggressiveness and have no
1927 influence on your browsing unless you select them explicitly in the editor.
1928 It is not recommend to edit this file.
1930 The list of actions files to be used are defined in the main configuration
1931 file, and are processed in the order they are defined. The content of these can
1932 all be viewed and edited from http://config.privoxy.org/show-status.
1934 An actions file typically has multiple sections. If you want to use "aliases"
1935 in an actions file, you have to place the (optional) alias section at the top
1936 of that file. Then comes the default set of rules which will apply universally
1937 to all sites and pages (be very careful with using such a universal set in
1938 user.action or any other actions file after default.action, because it will
1939 override the result from consulting any previous file). And then below that,
1940 exceptions to the defined universal policies. You can regard user.action as an
1941 appendix to default.action, with the advantage that is a separate file, which
1942 makes preserving your personal settings across Privoxy upgrades easier.
1944 Actions can be used to block anything you want, including ads, banners, or just
1945 some obnoxious URL that you would rather not see. Cookies can be accepted or
1946 rejected, or accepted only during the current browser session (i.e. not written
1947 to disk), content can be modified, JavaScripts tamed, user-tracking fooled, and
1948 much more. See below for a complete list of actions.
1950 -------------------------------------------------------------------------------
1952 8.1. Finding the Right Mix
1954 Note that some actions, like cookie suppression or script disabling, may render
1955 some sites unusable that rely on these techniques to work properly. Finding the
1956 right mix of actions is not always easy and certainly a matter of personal
1957 taste. In general, it can be said that the more "aggressive" your default
1958 settings (in the top section of the actions file) are, the more exceptions for
1959 "trusted" sites you will have to make later. If, for example, you want to kill
1960 popup windows per default, you'll have to make exceptions from that rule for
1961 sites that you regularly use and that require popups for actually useful
1962 content, like maybe your bank, favorite shop, or newspaper.
1964 We have tried to provide you with reasonable rules to start from in the
1965 distribution actions files. But there is no general rule of thumb on these
1966 things. There just are too many variables, and sites are constantly changing.
1967 Sooner or later you will want to change the rules (and read this chapter again
1970 -------------------------------------------------------------------------------
1974 The easiest way to edit the actions files is with a browser by using our
1975 browser-based editor, which can be reached from http://config.privoxy.org/
1976 show-status. The editor allows both fine-grained control over every single
1977 feature on a per-URL basis, and easy choosing from wholesale sets of defaults
1978 like "Cautious", "Medium" or "Advanced".
1980 If you prefer plain text editing to GUIs, you can of course also directly edit
1981 the the actions files. Look at default.action which is richly commented.
1983 -------------------------------------------------------------------------------
1985 8.3. How Actions are Applied to URLs
1987 Actions files are divided into sections. There are special sections, like the "
1988 alias" sections which will be discussed later. For now let's concentrate on
1989 regular sections: They have a heading line (often split up to multiple lines
1990 for readability) which consist of a list of actions, separated by whitespace
1991 and enclosed in curly braces. Below that, there is a list of URL patterns, each
1994 To determine which actions apply to a request, the URL of the request is
1995 compared to all patterns in each action file file. Every time it matches, the
1996 list of applicable actions for the URL is incrementally updated, using the
1997 heading of the section in which the pattern is located. If multiple matches for
1998 the same URL set the same action differently, the last match wins. If not, the
1999 effects are aggregated. E.g. a URL might match a regular section with a heading
2000 line of { +handle-as-image }, then later another one with just { +block },
2001 resulting in both actions to apply.
2003 You can trace this process for any given URL by visiting http://
2004 config.privoxy.org/show-url-info.
2006 More detail on this is provided in the Appendix, Anatomy of an Action.
2008 -------------------------------------------------------------------------------
2012 Generally, a pattern has the form <domain>/<path>, where both the <domain> and
2013 <path> are optional. (This is why the pattern / matches all URLs).
2017 is a domain-only pattern and will match any request to www.example.com,
2018 regardless of which document on that server is requested.
2022 means exactly the same. For domain-only patterns, the trailing / may be
2025 www.example.com/index.html
2027 matches only the single document /index.html on www.example.com.
2031 matches the document /index.html, regardless of the domain, i.e. on any web
2036 matches nothing, since it would be interpreted as a domain name and there
2037 is no top-level domain called .html.
2039 -------------------------------------------------------------------------------
2041 8.4.1. The Domain Pattern
2043 The matching of the domain part offers some flexible options: if the domain
2044 starts or ends with a dot, it becomes unanchored at that end. For example:
2048 matches any domain that ENDS in .example.com
2052 matches any domain that STARTS with www.
2056 matches any domain that CONTAINS .example. (Correctly speaking: It matches
2057 any FQDN that contains example as a domain.)
2059 Additionally, there are wild-cards that you can use in the domain names
2060 themselves. They work pretty similar to shell wild-cards: "*" stands for zero
2061 or more arbitrary characters, "?" stands for any single character, you can
2062 define character classes in square brackets and all of that can be freely
2067 matches "adserver.example.com", "ads.example.com", etc but not
2072 matches all of the above, and then some.
2076 matches www.ipix.com, pictures.epix.com, a.b.c.d.e.upix.com etc.
2078 www[1-9a-ez].example.c*
2080 matches www1.example.com, www4.example.cc, wwwd.example.cy,
2081 wwwz.example.com etc., but not wwww.example.com.
2083 -------------------------------------------------------------------------------
2085 8.4.2. The Path Pattern
2087 Privoxy uses Perl compatible regular expressions (through the PCRE library) for
2090 There is an Appendix with a brief quick-start into regular expressions, and
2091 full (very technical) documentation on PCRE regex syntax is available on-line
2092 at http://www.pcre.org/man.txt. You might also find the Perl man page on
2093 regular expressions (man perlre) useful, which is available on-line at http://
2094 www.perldoc.com/perl5.6/pod/perlre.html.
2096 Note that the path pattern is automatically left-anchored at the "/", i.e. it
2097 matches as if it would start with a "^" (regular expression speak for the
2098 beginning of a line).
2100 Please also note that matching in the path is CASE INSENSITIVE by default, but
2101 you can switch to case sensitive at any point in the pattern by using the "(?
2102 -i)" switch: www.example.com/(?-i)PaTtErN.* will match only documents whose
2103 path starts with PaTtErN in exactly this capitalization.
2105 -------------------------------------------------------------------------------
2109 All actions are disabled by default, until they are explicitly enabled
2110 somewhere in an actions file. Actions are turned on if preceded with a "+", and
2111 turned off if preceded with a "-". So a +action means "do that action", e.g.
2112 +block means "please block URLs that match the following patterns", and -block
2113 means "don't block URLs that match the following patterns, even if +block
2114 previously applied."
2116 Again, actions are invoked by placing them on a line, enclosed in curly braces
2117 and separated by whitespace, like in {+some-action -some-other-action
2118 {some-parameter}}, followed by a list of URL patterns, one per line, to which
2119 they apply. Together, the actions line and the following pattern lines make up
2120 a section of the actions file.
2122 There are three classes of actions:
2124 * Boolean, i.e the action can only be "enabled" or "disabled". Syntax:
2126 +name # enable action name
2127 -name # disable action name
2131 * Parameterized, where some value is required in order to enable this type of
2134 +name{param} # enable action and set parameter to param,
2135 # overwriting parameter from previous match if necessary
2136 -name # disable action. The parameter can be omitted
2138 Note that if the URL matches multiple positive forms of a parameterized
2139 action, the last match wins, i.e. the params from earlier matches are
2142 Example: +hide-user-agent{ Mozilla 1.0 }
2144 * Multi-value. These look exactly like parameterized actions, but they behave
2145 differently: If the action applies multiple times to the same URL, but with
2146 different parameters, all the parameters from all matches are remembered.
2147 This is used for actions that can be executed for the same request
2148 repeatedly, like adding multiple headers, or filtering through multiple
2151 +name{param} # enable action and add param to the list of parameters
2152 -name{param} # remove the parameter param from the list of parameters
2153 # If it was the last one left, disable the action.
2154 -name # disable this action completely and remove all parameters from the list
2156 Examples: +add-header{X-Fun-Header: Some text} and +filter{html-annoyances}
2158 If nothing is specified in any actions file, no "actions" are taken. So in this
2159 case Privoxy would just be a normal, non-blocking, non-anonymizing proxy. You
2160 must specifically enable the privacy and blocking features you need (although
2161 the provided default actions files will give a good starting point).
2163 Later defined actions always over-ride earlier ones. So exceptions to any rules
2164 you make, should come in the latter part of the file (or in a file that is
2165 processed later when using multiple actions files). For multi-valued actions,
2166 the actions are applied in the order they are specified. Actions files are
2167 processed in the order they are defined in config (the default installation has
2168 three actions files). It also quite possible for any given URL pattern to match
2169 more than one pattern and thus more than one set of actions!
2171 The list of valid Privoxy actions are:
2173 -------------------------------------------------------------------------------
2179 Confuse log analysis, custom applications
2183 Sends a user defined HTTP header to the web server.
2191 Any string value is possible. Validity of the defined HTTP headers is not
2192 checked. It is recommended that you use the "X-" prefix for custom headers.
2196 This action may be specified multiple times, in order to define multiple
2197 headers. This is rarely needed for the typical user. If you don't know what
2198 "HTTP headers" are, you definitely don't need to worry about this one.
2202 +add-header{X-User-Tracking: sucks}
2204 -------------------------------------------------------------------------------
2210 Block ads or other obnoxious content
2214 Requests for URLs to which this action applies are blocked, i.e. the
2215 requests are not forwarded to the remote server, but answered locally with
2216 a substitute page or image, as determined by the handle-as-image and
2217 set-image-blocker actions.
2229 Privoxy sends a special "BLOCKED" page for requests to blocked pages. This
2230 page contains links to find out why the request was blocked, and a
2231 click-through to the blocked content (the latter only if compiled with the
2232 force feature enabled). The "BLOCKED" page adapts to the available screen
2233 space -- it displays full-blown if space allows, or miniaturized and
2234 text-only if loaded into a small frame or window. If you are using Privoxy
2235 right now, you can take a look at the "BLOCKED" page.
2237 A very important exception occurs if both block and handle-as-image, apply
2238 to the same request: it will then be replaced by an image. If
2239 set-image-blocker (see below) also applies, the type of image will be
2240 determined by its parameter, if not, the standard checkerboard pattern is
2243 It is important to understand this process, in order to understand how
2244 Privoxy deals with ads and other unwanted content.
2246 The filter action can perform a very similar task, by "blocking" banner
2247 images and other content through rewriting the relevant URLs in the
2248 document's HTML source, so they don't get requested in the first place.
2249 Note that this is a totally different technique, and it's easy to confuse
2252 Example usage (section):
2254 {+block} # Block and replace with "blocked" page
2255 .nasty-stuff.example.com
2257 {+block +handle-as-image} # Block and replace with image
2261 -------------------------------------------------------------------------------
2263 8.5.3. crunch-incoming-cookies
2267 Prevent the web server from setting any cookies on your system
2271 Deletes any "Set-Cookie:" HTTP headers from server replies.
2283 This action is only concerned with incoming cookies. For outgoing cookies,
2284 use crunch-outgoing-cookies. Use both to disable cookies completely.
2286 It makes no sense at all to use this action in conjunction with the
2287 session-cookies-only action, since it would prevent the session cookies
2292 +crunch-incoming-cookies
2294 -------------------------------------------------------------------------------
2296 8.5.4. crunch-outgoing-cookies
2300 Prevent the web server from reading any cookies from your system
2304 Deletes any "Cookie:" HTTP headers from client requests.
2316 This action is only concerned with outgoing cookies. For incoming cookies,
2317 use crunch-incoming-cookies. Use both to disable cookies completely.
2319 It makes no sense at all to use this action in conjunction with the
2320 session-cookies-only action, since it would prevent the session cookies
2325 +crunch-outgoing-cookies
2327 -------------------------------------------------------------------------------
2329 8.5.5. deanimate-gifs
2333 Stop those annoying, distracting animated GIF images.
2337 De-animate GIF animations, i.e. reduce them to their first or last image.
2349 This will also shrink the images considerably (in bytes, not pixels!). If
2350 the option "first" is given, the first frame of the animation is used as
2351 the replacement. If "last" is given, the last frame of the animation is
2352 used instead, which probably makes more sense for most banner animations,
2353 but also has the risk of not showing the entire last frame (if it is only a
2354 delta to an earlier frame).
2356 You can safely use this action with patterns that will also match non-GIF
2357 objects, because no attempt will be made at anything that doesn't look like
2362 +deanimate-gifs{last}
2364 -------------------------------------------------------------------------------
2366 8.5.6. downgrade-http-version
2370 Work around (very rare) problems with HTTP/1.1
2374 Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0.
2386 This is a left-over from the time when Privoxy didn't support important
2387 HTTP/1.1 features well. It is left here for the unlikely case that you
2388 experience HTTP/1.1 related problems with some server out there. Not all
2389 (optional) HTTP/1.1 features are supported yet, so there is a chance you
2390 might need this action.
2392 Example usage (section):
2394 {+downgrade-http-version}
2395 problem-host.example.com
2397 -------------------------------------------------------------------------------
2399 8.5.7. fast-redirects
2403 Fool some click-tracking scripts and speed up indirect links
2407 Cut off all but the last valid URL from requests.
2419 Many sites, like yahoo.com, don't just link to other sites. Instead, they
2420 will link to some script on their own servers, giving the destination as a
2421 parameter, which will then redirect you to the final target. URLs resulting
2422 from this scheme typically look like: http://some.place/click-tracker.cgi?
2423 target=http://some.where.else.
2425 Sometimes, there are even multiple consecutive redirects encoded in the
2426 URL. These redirections via scripts make your web browsing more traceable,
2427 since the server from which you follow such a link can see where you go to.
2428 Apart from that, valuable bandwidth and time is wasted, while your browser
2429 ask the server for one redirect after the other. Plus, it feeds the
2432 This feature is currently not very smart and is scheduled for improvement.
2433 It is likely to break some sites. You should expect to need possibly many
2434 exceptions to this action, if it is enabled by default in default.action.
2435 Some sites just don't work without it.
2441 -------------------------------------------------------------------------------
2447 Get rid of HTML and JavaScript annoyances, banner advertisements (by size),
2448 do fun text replacements, etc.
2452 Text documents, including HTML and JavaScript, to which this action
2453 applies, are filtered on-the-fly through the specified regular expression
2454 based substitutions.
2462 The name of a filter, as defined in the filter file (typically
2463 default.filter, set by the filterfile option in the config file). Filtering
2464 can be completely disabled without the use of parameters.
2468 For your convenience, there are a number of pre-defined filters available
2469 in the distribution filter file that you can use. See the examples below
2472 This is potentially a very powerful feature! But "rolling your own" filters
2473 requires a knowledge of regular expressions and HTML.
2475 Filtering requires buffering the page content, which may appear to slow
2476 down page rendering since nothing is displayed until all content has passed
2477 the filters. (It does not really take longer, but seems that way since the
2478 page is not incrementally displayed.) This effect will be more noticeable
2479 on slower connections.
2481 The amount of data that can be filtered is limited to the buffer-limit
2482 option in the main config file. The default is 4096 KB (4 Megs). Once this
2483 limit is exceeded, the buffered data, and all pending data, is passed
2484 through unfiltered. Inappropriate MIME types are not filtered.
2486 At this time, Privoxy cannot (yet!) uncompress compressed documents. If you
2487 want filtering to work on all documents, even those that would normally be
2488 sent compressed, use the prevent-compression action in conjunction with
2491 Filtering can achieve some of the same effects as the block action, i.e. it
2492 can be used to block ads and banners. But the mechanism works quite
2493 differently. One effective use, is to block ad banners based on their size
2494 (see below), since many of these seem to be somewhat standardized.
2496 Feedback with suggestions for new or improved filters is particularly
2499 Example usage (with filters from the distribution default.filter file):
2501 +filter{html-annoyances} # Get rid of particularly annoying HTML abuse.
2503 +filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse
2505 +filter{banners-by-size} # Kill banners based on their size for this page (very efficient!)
2507 +filter{banners-by-link} # Kill banners based on the link they are contained in (experimental)
2509 +filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective
2511 +filter{content-cookies} # Kill cookies that come sneaking in the HTML or JS content
2513 +filter{popups} # Kill all popups in JS and HTML
2515 +filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking)
2517 +filter{fun} # Text replacements for subversive browsing fun!
2519 +filter{frameset-borders} # Give frames a border and make them resizeable
2521 +filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups)
2523 +filter{nimda} # Remove Nimda (virus) code.
2525 +filter{shockwave-flash} # Kill embedded Shockwave Flash objects
2527 +filter{crude-parental} # Kill all web pages that contain the words "sex" or "warez"
2529 +filter{js-events} # Kill all JS event bindings (Radically destructive! Only for extra nasty sites)
2531 -------------------------------------------------------------------------------
2533 8.5.9. handle-as-image
2537 Mark URLs as belonging to images (so they'll be replaced by images if they
2542 This action alone doesn't do anything noticeable. It just marks URLs as
2543 images. If the block action also applies, the presence or absence of this
2544 mark decides whether an HTML "blocked" page, or a replacement image (as
2545 determined by the set-image-blocker action) will be sent to the client as a
2546 substitute for the blocked content.
2558 The below generic example section is actually part of default.action. It
2559 marks all URLs with well-known image file name extensions as images and
2560 should be left intact.
2562 Users will probably only want to use the handle-as-image action in
2563 conjunction with block, to block sources of banners, whose URLs don't
2564 reflect the file type, like in the second example section.
2566 Note that you cannot treat HTML pages as images in most cases. For
2567 instance, (in-line) ad frames require an HTML page to be sent, or they
2568 won't display properly. Forcing handle-as-image in this situation will not
2569 replace the ad frame with an image, but lead to error messages.
2571 Example usage (sections):
2573 # Generic image extensions:
2576 /.*\.(gif|jpg|jpeg|png|bmp|ico)$
2578 # These don't look like images, but they're banners and should be
2579 # blocked as images:
2581 {+block +handle-as-image}
2582 some.nasty-banner-server.com/junk.cgi?output=trash
2584 # Banner source! Who cares if they also have non-image content?
2587 -------------------------------------------------------------------------------
2589 8.5.10. hide-forwarded-for-headers
2593 Improve privacy by hiding the true source of the request
2597 Deletes any existing "X-Forwarded-for:" HTTP header from client requests,
2598 and prevents adding a new one.
2610 It is fairly safe to leave this on.
2612 This action is scheduled for improvement: It should be able to generate
2613 forged "X-Forwarded-for:" headers using random IP addresses from a
2614 specified network, to make successive requests from the same client look
2615 like requests from a pool of different users sharing the same proxy.
2619 +hide-forwarded-for-headers
2621 -------------------------------------------------------------------------------
2623 8.5.11. hide-from-header
2627 Keep your (old and ill) browser from telling web servers your email address
2631 Deletes any existing "From:" HTTP header, or replaces it with the specified
2640 Keyword: "block", or any user defined value.
2644 The keyword "block" will completely remove the header (not to be confused
2645 with the block action).
2647 Alternately, you can specify any value you prefer to be sent to the web
2648 server. If you do, it is a matter of fairness not to use any address that
2649 is actually used by a real person.
2651 This action is rarely needed, as modern web browsers don't send "From:"
2656 +hide-from-header{block}
2660 +hide-from-header{spam-me-senseless@sittingduck.example.com}
2662 -------------------------------------------------------------------------------
2664 8.5.12. hide-referrer
2668 Conceal which link you followed to get to a particular site
2672 Deletes the "Referer:" (sic) HTTP header from the client request, or
2673 replaces it with a forged one.
2681 + "block" to delete the header completely.
2683 + "forge" to pretend to be coming from the homepage of the server we are
2686 + Any other string to set a user defined referrer.
2690 "forge" is the preferred option here, since some servers will not send
2691 images back otherwise, in an attempt to prevent their valuable content from
2692 being embedded elsewhere (and hence, without being surrounded by their
2695 hide-referer is an alternate spelling of hide-referrer and the two can be
2696 can be freely substituted with each other. ("referrer" is the correct
2697 English spelling, however the HTTP specification has a bug - it requires it
2698 to be spelled as "referer".)
2702 +hide-referrer{forge}
2706 +hide-referrer{http://www.yahoo.com/}
2708 -------------------------------------------------------------------------------
2710 8.5.13. hide-user-agent
2714 Conceal your type of browser and client operating system
2718 Replaces the value of the "User-Agent:" HTTP header in client requests with
2719 the specified value.
2727 Any user-defined string.
2731 +-----------------------------------------------------------------+
2733 |-----------------------------------------------------------------|
2734 |This breaks many web sites that depend on looking at this header |
2735 |in order to customize their content for different browsers |
2736 |(which, by the way, is NOT a smart way to do that!). |
2737 +-----------------------------------------------------------------+
2739 Using this action in multi-user setups or wherever different types of
2740 browsers will access the same Privoxy is not recommended. In single-user,
2741 single-browser setups, you might use it to delete your OS version
2742 information from the headers, because it is an invitation to exploit known
2743 bugs for your OS. It is also occasionally useful to forge this in order to
2744 access sites that won't let you in otherwise (though there may be a good
2745 reason in some cases). Example of this: some MSN sites will not let Mozilla
2746 enter, yet forging to a Netscape 6.1 user-agent works just fine. (Must be
2747 just a silly MS goof, I'm sure :-).
2749 This action is scheduled for improvement.
2753 +hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}
2755 -------------------------------------------------------------------------------
2761 Eliminate those annoying pop-up windows
2765 While loading the document, replace JavaScript code that opens pop-up
2766 windows with (syntactically neutral) dummy code on the fly.
2778 This action is easily confused with the built-in, hardwired filter action,
2779 but there are important differences: For kill-popups, the document need not
2780 be buffered, so it can be incrementally rendered while downloading. But
2781 kill-popups doesn't catch as many pop-ups as filter{popups} does.
2783 Think of it as a fast and efficient replacement for a filter that you can
2784 use if you don't want any filtering at all. Note that it doesn't make sense
2785 to combine it with any filter action, since as soon as one filter applies,
2786 the whole document needs to be buffered anyway, which destroys the
2787 advantage of the kill-popups action over its filter equivalent.
2789 Killing all pop-ups is a dangerous business. Many shops and banks rely on
2790 pop-ups to display forms, shopping carts etc, and killing only the unwanted
2791 pop-ups would require artificial intelligence in Privoxy. If the only kind
2792 of pop-ups that you want to kill are exit consoles (those really nasty
2793 windows that appear when you close an other one), you might want to use
2794 filter{js-annoyances} instead.
2800 -------------------------------------------------------------------------------
2802 8.5.15. limit-connect
2806 Prevent abuse of Privoxy as a TCP proxy relay
2810 Specifies to which ports HTTP CONNECT requests are allowable.
2818 A comma-separated list of ports or port ranges (the latter using dashes,
2819 with the minimum defaulting to 0 and the maximum to 65K).
2823 By default, i.e. if no limit-connect action applies, Privoxy only allows
2824 HTTP CONNECT requests to port 443 (the standard, secure HTTPS port). Use
2825 limit-connect if more fine-grained control is desired for some or all
2828 The CONNECT methods exists in HTTP to allow access to secure websites
2829 ("https://" URLs) through proxies. It works very simply: the proxy connects
2830 to the server on the specified port, and then short-circuits its
2831 connections to the client and to the remote server. This can be a big
2832 security hole, since CONNECT-enabled proxies can be abused as TCP relays
2835 If you don't know what any of this means, there probably is no reason to
2836 change this one, since the default is already very restrictive.
2840 +limit-connect{443} # This is the default and need not be specified.
2841 +limit-connect{80,443} # Ports 80 and 443 are OK.
2842 +limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
2843 +limit-connect{-} # All ports are OK (gaping security hole!)
2845 -------------------------------------------------------------------------------
2847 8.5.16. prevent-compression
2851 Ensure that servers send the content uncompressed, so it can be passed
2856 Adds a header to the request that asks for uncompressed transfer.
2868 More and more websites send their content compressed by default, which is
2869 generally a good idea and saves bandwidth. But for the filter,
2870 deanimate-gifs and kill-popups actions to work, Privoxy needs access to the
2871 uncompressed data. Unfortunately, Privoxy can't yet(!) uncompress, filter,
2872 and re-compress the content on the fly. So if you want to ensure that all
2873 websites, including those that normally compress, can be filtered, you need
2876 This will slow down transfers from those websites, though. If you use any
2877 of the above-mentioned actions, you will typically want to use
2878 prevent-compression in conjunction with them.
2880 Note that some (rare) ill-configured sites don't handle requests for
2881 uncompressed documents correctly (they send an empty document body). If you
2882 use prevent-compression per default, you'll have to add exceptions for
2883 those sites. See the example for how to do that.
2885 Example usage (sections):
2889 {+prevent-compression}
2892 # Make exceptions for ill sites:
2894 {-prevent-compression}
2896 www.pclinuxonline.com
2898 -------------------------------------------------------------------------------
2900 8.5.17. send-vanilla-wafer
2904 Feed log analysis scripts with useless data.
2908 Sends a cookie with each request stating that you do not accept any
2909 copyright on cookies sent to you, and asking the site operator not to track
2922 The vanilla wafer is a (relatively) unique header and could conceivably be
2925 This action is rarely used and not enabled in the default configuration.
2931 -------------------------------------------------------------------------------
2937 Send custom cookies or feed log analysis scripts with even more useless
2942 Sends a custom, user-defined cookie with each request.
2950 A string of the form "name=value".
2954 Being multi-valued, multiple instances of this action can apply to the same
2955 request, resulting in multiple cookies being sent.
2957 This action is rarely used and not enabled in the default configuration.
2959 Example usage (section):
2961 {+send-wafer{UsingPrivoxy=true}}
2962 my-internal-testing-server.void
2964 -------------------------------------------------------------------------------
2966 8.5.19. session-cookies-only
2970 Allow only temporary "session" cookies (for the current browser session
2975 Deletes the "expires" field from "Set-Cookie:" server headers. Most
2976 browsers will not store such cookies permanently and forget them in between
2989 This is less strict than crunch-incoming-cookies / crunch-outgoing-cookies
2990 and allows you to browse websites that insist or rely on setting cookies,
2991 without compromising your privacy too badly.
2993 Most browsers will not permanently store cookies that have been processed
2994 by session-cookies-only and will forget about them between sessions. This
2995 makes profiling cookies useless, but won't break sites which require
2996 cookies so that you can log in for transactions. This is generally turned
2997 on for all sites, and is the recommended setting.
2999 It makes no sense at all to use session-cookies-only together with
3000 crunch-incoming-cookies or crunch-outgoing-cookies. If you do, cookies will
3003 Note that it is up to the browser how it handles such cookies without an
3004 "expires" field. If you use an exotic browser, you might want to try it out
3009 +session-cookies-only
3011 -------------------------------------------------------------------------------
3013 8.5.20. set-image-blocker
3017 Choose the replacement for blocked images
3021 This action alone doesn't do anything noticeable. If both block and
3022 handle-as-image also apply, i.e. if the request is to be blocked as an
3023 image, then the parameter of this action decides what will be sent as a
3032 + "pattern" to send a built-in checkerboard pattern image. The image is
3033 visually decent, scales very well, and makes it obvious where banners
3036 + "blank" to send a built-in transparent image. This makes banners
3037 disappear completely, but makes it hard to detect where Privoxy has
3038 blocked images on a given page and complicates troubleshooting if
3039 Privoxy has blocked innocent images, like navigation icons.
3041 + "target-url" to send a redirect to target-url. You can redirect to any
3042 image anywhere, even in your local filesystem (via "file:///" URL).
3044 A good application of redirects is to use special Privoxy-built-in
3045 URLs, which send the built-in images, as target-url. This has the same
3046 visual effect as specifying "blank" or "pattern" in the first place,
3047 but enables your browser to cache the replacement image, instead of
3048 requesting it over and over again.
3052 The URLs for the built-in images are "http://config.privoxy.org/
3053 send-banner?type=type", where type is either "blank" or "pattern".
3055 There is a third (advanced) type, called "auto". It is NOT to be used in
3056 set-image-blocker, but meant for use from filters. Auto will select the
3057 type of image that would have applied to the referring page, had it been an
3064 +set-image-blocker{pattern}
3066 Redirect to the BSD devil:
3068 +set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}
3070 Redirect to the built-in pattern for better caching:
3072 +set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}
3074 -------------------------------------------------------------------------------
3078 Note that many of these actions have the potential to cause a page to
3079 misbehave, possibly even not to display at all. There are many ways a site
3080 designer may choose to design his site, and what HTTP header content, and other
3081 criteria, he may depend on. There is no way to have hard and fast rules for all
3082 sites. See the Appendix for a brief example on troubleshooting actions.
3084 -------------------------------------------------------------------------------
3088 Custom "actions", known to Privoxy as "aliases", can be defined by combining
3089 other actions. These can in turn be invoked just like the built-in actions.
3090 Currently, an alias name can contain any character except space, tab, "=", "{"
3091 and "}", but we strongly recommend that you only use "a" to "z", "0" to "9",
3092 "+", and "-". Alias names are not case sensitive, and are not required to start
3093 with a "+" or "-" sign, since they are merely textually expanded.
3095 Aliases can be used throughout the actions file, but they must be defined in a
3096 special section at the top of the file! And there can only be one such section
3097 per actions file. Each actions file may have its own alias section, and the
3098 aliases defined in it are only visible within that file.
3100 There are two main reasons to use aliases: One is to save typing for frequently
3101 used combinations of actions, the other one is a gain in flexibility: If you
3102 decide once how you want to handle shops by defining an alias called "shop",
3103 you can later change your policy on shops in one place, and your changes will
3104 take effect everywhere in the actions file where the "shop" alias is used.
3105 Calling aliases by their purpose also makes your actions files more readable.
3107 Currently, there is one big drawback to using aliases, though: Privoxy's
3108 built-in web-based action file editor honors aliases when reading the actions
3109 files, but it expands them before writing. So the effects of your aliases are
3110 of course preserved, but the aliases themselves are lost when you edit sections
3111 that use aliases with it. This is likely to change in future versions of
3114 Now let's define some aliases...
3116 # Useful custom aliases we can use later.
3118 # Note the (required!) section header line and that this section
3119 # must be at the top of the actions file!
3123 # These aliases just save typing later:
3124 # (Note that some already use other aliases!)
3126 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
3127 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
3128 block-as-image = +block +handle-as-image
3129 mercy-for-cookies = -crunch-all-cookies -session-cookies-only
3131 # These aliases define combinations of actions
3132 # that are useful for certain types of sites:
3134 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
3135 shop = -crunch-all-cookies -filter{popups} -kill-popups
3137 # Short names for other aliases, for really lazy people ;-)
3139 c0 = +crunch-all-cookies
3140 c1 = -crunch-all-cookies
3142 ...and put them to use. These sections would appear in the lower part of an
3143 actions file and define exceptions to the default actions (as specified further
3144 up for the "/" pattern):
3146 # These sites are either very complex or very keen on
3147 # user data and require minimal interference to work:
3150 .office.microsoft.com
3151 .windowsupdate.microsoft.com
3155 # Allow cookies (for setting and retrieving your customer data)
3159 .worldpay.com # for quietpc.com
3162 # These shops require pop-ups:
3164 {shop -kill-popups -filter{popups}}
3168 Aliases like "shop" and "fragile" are often used for "problem" sites that
3169 require some actions to be disabled in order to function properly.
3171 -------------------------------------------------------------------------------
3173 8.7. Actions Files Tutorial
3175 The above chapters have shown which actions files there are and how they are
3176 organized, how actions are specified and applied to URLs, how patterns work,
3177 and how to define and use aliases. Now, let's look at an example default.action
3178 and user.action file and see how all these pieces come together:
3180 -------------------------------------------------------------------------------
3182 8.7.1. default.action
3184 Every config file should start with a short comment stating its purpose:
3186 # Sample default.action file <developers@privoxy.org>
3188 Then, since this is the default.action file, the first section is a special
3189 section for internal use that you needn't change or worry about:
3191 ##########################################################################
3192 # Settings -- Don't change! For internal Privoxy use ONLY.
3193 ##########################################################################
3196 for-privoxy-version=3.0
3198 After that comes the (optional) alias section. We'll use the example section
3199 from the above chapter on aliases, that also explains why and how aliases are
3202 ##########################################################################
3204 ##########################################################################
3207 # These aliases just save typing later:
3208 # (Note that some already use other aliases!)
3210 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
3211 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
3212 block-as-image = +block +handle-as-image
3213 mercy-for-cookies = -crunch-all-cookies -session-cookies-only
3215 # These aliases define combinations of actions
3216 # that are useful for certain types of sites:
3218 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
3219 shop = mercy-for-cookies -filter{popups} -kill-popups
3221 Now come the regular sections, i.e. sets of actions, accompanied by URL
3222 patterns to which they apply. Remember all actions are disabled when matching
3223 starts, so we have to explicitly enable the ones we want.
3225 The first regular section is probably the most important. It has only one
3226 pattern, "/", but this pattern matches all URLs. Therefore, the set of actions
3227 used in this "default" section will be applied to all requests as a start. It
3228 can be partly or wholly overridden by later matches further down this file, or
3229 in user.action, but it will still be largely responsible for your overall
3230 browsing experience.
3232 Again, at the start of matching, all actions are disabled, so there is no real
3233 need to disable any actions here, but we will do that nonetheless, to have a
3234 complete listing for your reference. (Remember: a "+" preceding the action name
3235 enables the action, a "-" disables!). Also note how this long line has been
3236 made more readable by splitting it into multiple lines with line continuation.
3238 ##########################################################################
3239 # "Defaults" section:
3240 ##########################################################################
3244 -crunch-incoming-cookies \
3245 -crunch-outgoing-cookies \
3247 -downgrade-http-version \
3249 +filter{html-annoyances} \
3250 +filter{js-annoyances} \
3251 -filter{content-cookies} \
3254 -filter{refresh-tags} \
3257 +filter{banners-by-size} \
3258 -filter{banners-by-link} \
3259 -filter{img-reorder} \
3260 -filter{shockwave-flash} \
3261 -filter{crude-parental} \
3262 -filter{js-events} \
3264 +hide-forwarded-for-headers \
3265 +hide-from-header{block} \
3266 +hide-referrer{forge} \
3270 +prevent-compression \
3271 -send-vanilla-wafer \
3273 +session-cookies-only \
3274 +set-image-blocker{pattern} \
3276 / # forward slash will match *all* potential URL patterns.
3278 The default behavior is now set. Note that some actions, like not hiding the
3279 user agent, are part of a "general policy" that applies universally and won't
3280 get any exceptions defined later. Other choices, like not blocking (which is
3281 understandably the default!) need exceptions, i.e. we need to specify
3282 explicitly what we want to block in later sections. We will also want to make
3283 exceptions from our general pop-up-killing, and use our defined aliases for
3286 The first of our specialized sections is concerned with "fragile" sites, i.e.
3287 sites that require minimum interference, because they are either very complex
3288 or very keen on tracking you (and have mechanisms in place that make them
3289 unusable for people who avoid being tracked). We will simply use our
3290 pre-defined fragile alias instead of stating the list of actions explicitly:
3292 ##########################################################################
3293 # Exceptions for sites that'll break under the default action set:
3294 ##########################################################################
3296 # "Fragile" Use a minimum set of actions for these sites (see alias above):
3299 .office.microsoft.com # surprise, surprise!
3300 .windowsupdate.microsoft.com
3302 Shopping sites are not as fragile, but they typically require cookies to log
3303 in, and pop-up windows for shopping carts or item details. Again, we'll use a
3310 .worldpay.com # for quietpc.com
3314 Then, there are sites which rely on pop-up windows (yuck!) to work. Since we
3315 made pop-up-killing our default above, we need to make exceptions now. Mozilla
3316 users, who can turn on smart handling of unwanted pop-ups in their browsers,
3317 can safely choose -filter{popups} (and -kill-popups) above and hence don't need
3318 this section. Anyway, disabling an already disabled action doesn't hurt, so
3319 we'll define our exceptions regardless of what was chosen in the defaults
3322 # These sites require pop-ups too :(
3324 { -kill-popups -filter{popups} }
3327 .deutsche-bank-24.de
3329 The fast-redirects action, which we enabled per default above, breaks some
3330 sites. So disable it for popular sites where we know it misbehaves:
3336 .altavista.com/.*(like|url|link):http
3337 .altavista.com/trans.*urltext=http
3340 It is important that Privoxy knows which URLs belong to images, so that if they
3341 are to be blocked, a substitute image can be sent, rather than an HTML page.
3342 Contacting the remote site to find out is not an option, since it would destroy
3343 the loading time advantage of banner blocking, and it would feed the
3344 advertisers (in terms of money and information). We can mark any URL as an
3345 image with the handle-as-image action, and marking all URLs that end in a known
3346 image file extension is a good start:
3348 ##########################################################################
3350 ##########################################################################
3352 # Define which file types will be treated as images, in case they get
3353 # blocked further down this file:
3355 { +handle-as-image }
3356 /.*\.(gif|jpe?g|png|bmp|ico)$
3358 And then there are known banner sources. They often use scripts to generate the
3359 banners, so it won't be visible from the URL that the request is for an image.
3360 Hence we block them and mark them as images in one go, with the help of our
3361 block-as-image alias defined above. (We could of course just as well use +block
3362 +handle-as-image here.) Remember that the type of the replacement image is
3363 chosen by the set-image-blocker action. Since all URLs have matched the default
3364 section with its +set-image-blocker{pattern} action before, it still applies
3365 and needn't be repeated:
3367 # Known ad generators:
3372 .ad.*.doubleclick.net
3373 .a.yimg.com/(?:(?!/i/).)*$
3374 .a[0-9].yimg.com/(?:(?!/i/).)*$
3379 One of the most important jobs of Privoxy is to block banners. A huge bunch of
3380 them are already "blocked" by the filter{banners-by-size} action, which we
3381 enabled above, and which deletes the references to banner images from the pages
3382 while they are loaded, so the browser doesn't request them anymore, and hence
3383 they don't need to be blocked here. But this naturally doesn't catch all
3384 banners, and some people choose not to use filters, so we need a comprehensive
3385 list of patterns for banner URLs here, and apply the block action to them.
3387 First comes a bunch of generic patterns, which do most of the work, by matching
3388 typical domain and path name components of banners. Then comes a list of
3389 individual patterns for specific sites, which is omitted here to keep the
3392 ##########################################################################
3393 # Block these fine banners:
3394 ##########################################################################
3403 /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
3404 /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
3406 # Site-specific patterns (abbreviated):
3410 You wouldn't believe how many advertisers actually call their banner servers
3411 ads.company.com, or call the directory in which the banners are stored simply
3412 "banners". So the above generic patterns are surprisingly effective.
3414 But being very generic, they necessarily also catch URLs that we don't want to
3415 block. The pattern .*ads. e.g. catches "nasty-ads.nasty-corp.com" as intended,
3416 but also "downloads.sourcefroge.net" or "adsl.some-provider.net." So here come
3417 some well-known exceptions to the +block section above.
3419 Note that these are exceptions to exceptions from the default! Consider the URL
3420 "downloads.sourcefroge.net": Initially, all actions are deactivated, so it
3421 wouldn't get blocked. Then comes the defaults section, which matches the URL,
3422 but just deactivates the block action once again. Then it matches .*ads., an
3423 exception to the general non-blocking policy, and suddenly +block applies. And
3424 now, it'll match .*loads., where -block applies, so (unless it matches again
3425 further down) it ends up with no block action applying.
3427 ##########################################################################
3428 # Save some innocent victims of the above generic block patterns:
3429 ##########################################################################
3434 adv[io]*. # (for advogato.org and advice.*)
3435 adsl. # (has nothing to do with ads)
3436 ad[ud]*. # (adult.* and add.*)
3437 .edu # (universities don't host banners (yet!))
3438 .*loads. # (downloads, uploads etc)
3446 www.globalintersec.com/adv # (adv = advanced)
3447 www.ugu.com/sui/ugu/adv
3449 Filtering source code can have nasty side effects, so make an exception for our
3450 friends at sourceforge.net, and all paths with "cvs" in them. Note that -filter
3451 disables all filters in one fell swoop!
3453 # Don't filter code!
3459 The actual default.action is of course more comprehensive, but we hope this
3460 example made clear how it works.
3462 -------------------------------------------------------------------------------
3466 So far we are painting with a broad brush by setting general policies, which
3467 would be a reasonable starting point for many people. Now, you might want to be
3468 more specific and have customized rules that are more suitable to your personal
3469 habits and preferences. These would be for narrowly defined situations like
3470 your ISP or your bank, and should be placed in user.action, which is parsed
3471 after all other actions files and hence has the last word, over-riding any
3472 previously defined actions. user.action is also a safe place for your personal
3473 settings, since default.action is actively maintained by the Privoxy developers
3474 and you'll probably want to install updated versions from time to time.
3476 So let's look at a few examples of things that one might typically do in
3479 # My user.action file. <fred@foobar.com>
3481 As aliases are local to the actions file that they are defined in, you can't
3482 use the ones from default.action, unless you repeat them here:
3484 # (Re-)define aliases for this file:
3487 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
3488 mercy-for-cookies = -crunch-all-cookies -session-cookies-only
3489 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
3490 shop = mercy-for-cookies -filter{popups} -kill-popups
3491 allow-ads = -block -filter{banners-by-size} # (see below)
3493 Say you have accounts on some sites that you visit regularly, and you don't
3494 want to have to log in manually each time. So you'd like to allow persistent
3495 cookies for these sites. The mercy-for-cookies alias defined above does exactly
3496 that, i.e. it disables crunching of cookies in any direction, and processing of
3497 cookies to make them temporary.
3499 { mercy-for-cookies }
3506 Your bank needs popups and is allergic to some filter, but you don't know
3507 which, so you disable them all:
3509 { -filter -kill-popups }
3510 .your-home-banking-site.com
3512 While browsing the web with Privoxy you noticed some ads that sneaked through,
3513 but you were too lazy to report them through our fine and easy feedback system,
3514 so you have added them here:
3517 www.a-popular-site.com/some/unobvious/path
3518 another.popular.site.net/more/junk/here/
3520 Note that, assuming the banners in the above example have regular image
3521 extensions (most do), +handle-as-image need not be specified, since all URLs
3522 ending in these extensions will already have been tagged as images in the
3523 relevant section of default.action by now.
3525 Then you noticed that the default configuration breaks Forbes Magazine, but you
3526 were too lazy to find out which action is the culprit, and you were again too
3527 lazy to give feedback, so you just used the fragile alias on the site, and --
3533 You like the "fun" text replacements in default.filter, but it is disabled in
3534 the distributed actions file. (My colleagues on the team just don't have a
3535 sense of humour, that's why! ;-). So you'd like to turn it on in your private,
3536 update-safe config, once and for all:
3541 Note that the above is not really a good idea: There are exceptions to the
3542 filters in default.action for things that really shouldn't be filtered, like
3543 code on CVS->Web interfaces. Since user.action has the last word, these
3544 exceptions won't be valid for the "fun" filtering specified here.
3546 Finally, you might think about how your favourite free websites are funded, and
3547 find that they rely on displaying banner advertisements to survive. So you
3548 might want to specifically allow banners for those sites that you feel provide
3556 Note that allow-ads has been aliased to -block -filter{banners-by-size} above.
3558 -------------------------------------------------------------------------------
3562 All text substitutions that can be invoked through the filter action must first
3563 be defined in the filter file, which is typically called default.filter and
3564 which can be selected through the filterfile config option.
3566 Typical reasons for doing such substitutions are to eliminate common annoyances
3567 in HTML and JavaScript, such as pop-up windows, exit consoles, crippled windows
3568 without navigation tools, the infamous <BLINK> tag etc, to suppress images with
3569 certain width and height attributes (standard banner sizes or web-bugs), or
3570 just to have fun. The possibilities are endless.
3572 Filtering works on any text-based document type, including plain text, HTML,
3573 JavaScript, CSS etc. (all text/* MIME types). Substitutions are made at the
3574 source level, so if you want to "roll your own" filters, you should be familiar
3577 Just like the actions files, the filter file is organized in sections, which
3578 are called filters here. Each filter consists of a heading line, that starts
3579 with the keyword FILTER:, followed by the filter's name, and a short (one line)
3580 description of what it does. Below that line come the jobs, i.e. lines that
3581 define the actual text substitutions. By convention, the name of a filter
3582 should describe what the filter eliminates. The comment is used in the
3583 web-based user interface.
3585 Once a filter called name has been defined in the filter file, it can be
3586 invoked by using an action of the form +filter{name} in any actions file.
3588 A filter header line for a filter called "foo" could look like this:
3590 FILTER: foo Replace all "foo" with "bar"
3592 Below that line, and up to the next header line, come the jobs that define what
3593 text replacements the filter executes. They are specified in a syntax that
3594 imitates Perl's s/// operator. If you are familiar with Perl, you will find
3595 this to be quite intuitive, and may want to look at the PCRS man page for the
3596 subtle differences to Perl behaviour. Most notably, the non-standard option
3597 letter U is supported, which turns the default to ungreedy matching.
3599 If you are new to regular expressions, you might want to take a look at the
3600 Appendix on regular expressions, and see the Perl manual for the s///
3601 operator's syntax and Perl-style regular expressions in general. The below
3602 examples might also help to get you started.
3604 -------------------------------------------------------------------------------
3606 9.1. Filter File Tutorial
3608 Now, let's complete our "foo" filter. We have already defined the heading, but
3609 the jobs are still missing. Since all it does is to replace "foo" with "bar",
3610 there is only one (trivial) job needed:
3614 But wait! Didn't the comment say that all occurrences of "foo" should be
3615 replaced? Our current job will only take care of the first "foo" on each page.
3616 For global substitution, we'll need to add the g option:
3620 Our complete filter now looks like this:
3622 FILTER: foo Replace all "foo" with "bar"
3625 Let's look at some real filters for more interesting examples. Here you see a
3626 filter that protects against some common annoyances that arise from JavaScript
3627 abuse. Let's look at its jobs one after the other:
3629 FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse
3631 # Get rid of JavaScript referrer tracking. Test page: http://www.randomoddness.com/untitled.htm
3633 s|(<script.*)document\.referrer(.*</script>)|$1"Not Your Business!"$2|Usg
3635 Following the header line and a comment, you see the job. Note that it uses |
3636 as the delimiter instead of /, because the pattern contains a forward slash,
3637 which would otherwise have to be escaped by a backslash (\).
3639 Now, let's examine the pattern: it starts with the text <script.* enclosed in
3640 parentheses. Since the dot matches any character, and * means: "Match an
3641 arbitrary number of the element left of myself", this matches "<script",
3642 followed by any text, i.e. it matches the whole page, from the start of the
3645 That's more than we want, but the pattern continues: document\.referrer matches
3646 only the exact string "document.referrer". The dot needed to be escaped, i.e.
3647 preceded by a backslash, to take away its special meaning as a joker, and make
3648 it just a regular dot. So far, the meaning is: Match from the start of the
3649 first <script> tag in a the page, up to, and including, the text
3650 "document.referrer", if both are present in the page (and appear in that
3653 But there's still more pattern to go. The next element, again enclosed in
3654 parentheses, is .*</script>. You already know what .* means, so the whole
3655 pattern translates to: Match from the start of the first <script> tag in a page
3656 to the end of the last <script> tag, provided that the text "document.referrer"
3657 appears somewhere in between.
3659 This is still not the whole story, since we have ignored the options and the
3660 parentheses: The portions of the page matched by sub-patterns that are enclosed
3661 in parentheses, will be remembered and be available through the variables $1,
3662 $2, ... in the substitute. The U option switches to ungreedy matching, which
3663 means that the first .* in the pattern will only "eat up" all text in between "
3664 <script" and the first occurrence of "document.referrer", and that the second .
3665 * will only span the text up to the first "</script>" tag. Furthermore, the s
3666 option says that the match may span multiple lines in the page, and the g
3667 option again means that the substitution is global.
3669 So, to summarize, the pattern means: Match all scripts that contain the text
3670 "document.referrer". Remember the parts of the script from (and including) the
3671 start tag up to (and excluding) the string "document.referrer" as $1, and the
3672 part following that string, up to and including the closing tag, as $2.
3674 Now the pattern is deciphered, but wasn't this about substituting things? So
3675 lets look at the substitute: $1"Not Your Business!"$2 is easy to read: The text
3676 remembered as $1, followed by "Not Your Business!" (including the quotation
3677 marks!), followed by the text remembered as $2. This produces an exact copy of
3678 the original string, with the middle part (the "document.referrer") replaced by
3679 "Not Your Business!".
3681 The whole job now reads: Replace "document.referrer" by "Not Your Business!"
3682 wherever it appears inside a <script> tag. Note that this job won't break
3683 JavaScript syntax, since both the original and the replacement are
3684 syntactically valid string objects. The script just won't have access to the
3685 referrer information anymore.
3687 We'll show you two other jobs from the JavaScript taming department, but this
3688 time only point out the constructs of special interest:
3690 # The status bar is for displaying link targets, not pointless blahblah
3692 s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig
3694 \s stands for whitespace characters (space, tab, newline, carriage return, form
3695 feed), so that \s* means: "zero or more whitespace". The ? in .*? makes this
3696 matching of arbitrary text ungreedy. (Note that the U option is not set). The
3697 ['"] construct means: "a single or a double quote". Finally, \1 is a
3698 backreference to the first parenthesis just like $1 above, with the difference
3699 that in the pattern, a backslash indicates a backreference, whereas in the
3700 substitute, it's the dollar.
3702 So what does this job do? It replaces assignments of single- or double-quoted
3703 strings to the "window.status" object with a dummy assignment (using a variable
3704 name that is hopefully odd enough not to conflict with real variables in
3705 scripts). Thus, it catches many cases where e.g. pointless descriptions are
3706 displayed in the status bar instead of the link target when you move your mouse
3709 # Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html
3711 s/(<body [^>]*)onunload(.*>)/$1never$2/iU
3713 Including the OnUnload event binding in the HTML DOM was a CRIME. When I close
3714 a browser window, I want it to close and die. Basta. This job replaces the
3715 "onunload" attribute in "<body>" tags with the dummy word never. Note that the
3716 i option makes the pattern matching case-insensitive. Also note that ungreedy
3717 matching alone doesn't always guarantee a minimal match: In the first
3718 parenthesis, we had to use [^>]* instead of .* to prevent the match from
3719 exceeding the <body> tag if it doesn't contain "OnUnload", but the page's
3722 The last example is from the fun department:
3724 FILTER: fun Fun text replacements
3726 # Spice the daily news:
3728 s/microsoft(?!\.com)/MicroSuck/ig
3730 Note the (?!\.com) part (a so-called negative lookahead) in the job's pattern,
3731 which means: Don't match, if the string ".com" appears directly following
3732 "microsoft" in the page. This prevents links to microsoft.com from being
3733 trashed, while still replacing the word everywhere else.
3735 # Buzzword Bingo (example for extended regex syntax)
3737 s* industry[ -]leading \
3739 | customer[ -]focused \
3740 | market[ -]driven \
3741 | award[ -]winning # Comments are OK, too! \
3742 | high[ -]performance \
3743 | solutions[ -]based \
3747 *<font color="red"><b>BINGO!</b></font> \
3750 The x option in this job turns on extended syntax, and allows for e.g. the
3751 liberal use of (non-interpreted!) whitespace for nicer formatting.
3755 -------------------------------------------------------------------------------
3759 All Privoxy built-in pages, i.e. error pages such as the "404 - No Such Domain"
3760 error page, the "BLOCKED" page and all pages of its web-based user interface,
3761 are generated from templates. (Privoxy must be running for the above links to
3764 These templates are stored in a subdirectory of the configuration directory
3765 called templates. On Unixish platforms, this is typically /etc/privoxy/
3768 The templates are basically normal HTML files, but with place-holders (called
3769 symbols or exports), which Privoxy fills at run time. You can edit the
3770 templates with a normal text editor, should you want to customize them. (Not
3771 recommended for the casual user). Note that just like in configuration files,
3772 lines starting with # are ignored when the templates are filled in.
3774 The place-holders are of the form @name@, and you will find a list of available
3775 symbols, which vary from template to template, in the comments at the start of
3776 each file. Note that these comments are not always accurate, and that it's
3777 probably best to look at the existing HTML code to find out which symbols are
3778 supported and what they are filled in with.
3780 A special application of this substitution mechanism is to make whole blocks of
3781 HTML code disappear when a specific symbol is set. We use this for many
3782 purposes, one of them being to include the beta warning in all our user
3783 interface (CGI) pages when Privoxy in in an alpha or beta development stage:
3785 <!-- @if-unstable-start -->
3787 ... beta warning HTML code goes here ...
3789 <!-- if-unstable-end@ -->
3791 If the "unstable" symbol is set, everything in between and including
3792 @if-unstable-start and if-unstable-end@ will disappear, leaving nothing but an
3797 There's also an if-then-else construct and an #include mechanism, but you'll
3798 sure find out if you are inclined to edit the templates ;-)
3800 All templates refer to a style located at http://config.privoxy.org/
3801 send-stylesheet. This is, of course, locally served by Privoxy and the source
3802 for it can be found and edited in the cgi-style.css template.
3804 -------------------------------------------------------------------------------
3806 11. Contacting the Developers, Bug Reporting and Feature Requests
3808 We value your feedback. In fact, we rely on it to improve Privoxy and its
3809 configuration. However, please note the following hints, so we can provide you
3810 with the best support:
3812 -------------------------------------------------------------------------------
3816 For casual users, our support forum at SourceForge is probably best suited:
3817 http://sourceforge.net/tracker/?group_id=11118&atid=211118
3819 All users are of course welcome to discuss their issues on the users mailing
3820 list, where the developers also hang around.
3822 -------------------------------------------------------------------------------
3826 Please report all bugs only through our bug tracker: http://sourceforge.net/
3827 tracker/?group_id=11118&atid=111118.
3829 Before doing so, please make sure that the bug has not already been submitted
3830 and observe the additional hints at the top of the submit form.
3832 Please try to verify that it is a Privoxy bug, and not a browser or site bug
3833 first. If unsure, try toggling off Privoxy, and see if the problem persists.
3834 The appendix of the user manual also has helpful information on action
3835 debugging. If you are using your own custom configuration, please try the stock
3836 configs to see if the problem is configuration related.
3838 If not using the latest version, chances are that the bug has been found and
3839 fixed in the meantime. We would appreciate if you could take the time to
3840 upgrade to the latest version (or even the latest CVS snapshot) and verify your
3841 bug, but this is not required for reporting.
3843 -------------------------------------------------------------------------------
3845 11.3. Request New Features
3847 You are welcome to submit ideas on new features or other proposals for
3848 improvement through our feature request tracker at http://sourceforge.net/
3849 tracker/?atid=361118&group_id=11118.
3851 -------------------------------------------------------------------------------
3853 11.4. Report Ads or Other Actions-Related Problems
3855 Please send feedback on ads that slipped through, innocent images that were
3856 blocked, and any other problems relating to the default.action file through our
3857 actions feedback mechanism located at http://www.privoxy.org/actions/. On this
3858 page, you will also find a bookmark which will take you back there from any
3859 troubled site and even pre-fill the form!
3861 New, improved default.action files will occasionally be made available based on
3862 your feedback. These will be announced on the ijbswa-announce list and
3863 available from our the files section of our project page.
3865 -------------------------------------------------------------------------------
3869 For any other issues, feel free to use the mailing lists. Technically
3870 interested users and people who wish to contribute to the project are also
3871 welcome on the developers list! You can find an overview of all Privoxy-related
3872 mailing lists, including list archives, at: http://sourceforge.net/mail/?
3875 -------------------------------------------------------------------------------
3877 12. Privoxy Copyright, License and History
3879 Copyright © 2001, 2002 by Privoxy Developers <developers@privoxy.org>
3881 Some source code is based on code Copyright © 1997 by Anonymous Coders and
3882 Junkbusters, Inc. and licensed under the GNU General Public License.
3884 -------------------------------------------------------------------------------
3888 Privoxy is free software; you can redistribute it and/or modify it under the
3889 terms of the GNU General Public License, version 2, as published by the Free
3890 Software Foundation.
3892 This program is distributed in the hope that it will be useful, but WITHOUT ANY
3893 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
3894 PARTICULAR PURPOSE. See the GNU General Public License for more details, which
3895 is available from the Free Software Foundation, Inc, 59 Temple Place - Suite
3896 330, Boston, MA 02111-1307, USA.
3898 You should have received a copy of the GNU General Public License along with
3899 this program; if not, write to the
3902 Foundation, Inc. 59 Temple Place - Suite 330
3903 Boston, MA 02111-1307
3906 -------------------------------------------------------------------------------
3910 In the beginning, there was the Internet Junkbuster, by Anonymous Coders and
3911 Junkbusters Corporation. It saved many users a lot of pain in the early days of
3912 web advertising and user tracking.
3914 But the web, its protocols and standards, and with it, the techniques for
3915 forcing users to consume ads, give up autonomy over their browsing, and for
3916 spying on them, kept evolving. Unfortunately, the Internet Junkbuster did not.
3917 Version 2.0.2, published in 1998, was (and is) the last official release
3918 available from Junkbusters Corporation. Fortunately, it had been released under
3919 the GNU GPL, which allowed further development by others.
3921 So Stefan Waldherr started maintaining an improved version of the software, to
3922 which eventually a number of people contributed patches. It could already
3923 replace banners with a transparent image, and had a first version of pop-up
3924 killing, but it was still very closely based on the original, with all its
3925 limitations, such as the lack of HTTP/1.1 support, flexible per-site
3926 configuration, or content modification. The last release from this effort was
3927 version 2.0.2-10, published in 2000.
3929 Then, some developers picked up the thread, and started turning the software
3930 inside out, upside down, and then reassembled it, adding many new features
3933 The result of this is Privoxy, whose first stable release, 3.0, was released
3936 -------------------------------------------------------------------------------
3940 Current Project Developers:
3949 Current Project Contributors:
3951 Rodrigo Barbosa (RPM specfiles)
3954 Karsten Hopp (Red Hat)
3959 Roland Rosenfeld (Debian)
3960 Georg Sauthoff (Gentoo)
3961 David Schmidt (OS/2, Mac OSX ports)
3962 Joerg Strohmayer (Amiga)
3965 Based in part on code originally developed by:
3970 Thanks to the many people who have tested Privoxy, reported bugs, or made
3971 suggestions. These include (in alphabetical order):
3990 -------------------------------------------------------------------------------
3994 Other references and sites of interest to Privoxy users:
3996 http://www.privoxy.org/, the Privoxy Home page.
3998 http://www.privoxy.org/faq/, the Privoxy FAQ.
4000 http://sourceforge.net/projects/ijbswa/, the Project Page for Privoxy on
4003 http://config.privoxy.org/, the web-based user interface. Privoxy must be
4004 running for this to work. Shortcut: http://p.p/
4006 http://www.privoxy.org/actions/, to submit "misses" to the developers.
4008 http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/ijbswa/contrib/, cool and fun
4009 ideas from Privoxy users.
4011 http://www.junkbusters.com/ht/en/cookies.html, an explanation how cookies are
4012 used to track web users.
4014 http://www.junkbusters.com/ijb.html, the original Internet Junkbuster.
4016 http://www.waldherr.org/junkbuster/, Stefan Waldherr's version of Junkbuster,
4017 from which Privoxy was derived.
4019 http://privacy.net/analyze/, a useful site to check what information about you
4020 is leaked while you browse the web.
4022 http://www.squid-cache.org/, a very popular caching proxy, which is often used
4023 together with Privoxy.
4025 http://www.privoxy.org/developer-manual/, the Privoxy developer manual.
4027 -------------------------------------------------------------------------------
4031 14.1. Regular Expressions
4033 Privoxy uses Perl-style "regular expressions" in its actions files and filter
4034 file, through the PCRE and PCRS libraries.
4036 If you are reading this, you probably don't understand what "regular
4037 expressions" are, or what they can do. So this will be a very brief
4038 introduction only. A full explanation would require a book ;-)
4040 Regular expressions provide a language to describe patterns that can be run
4041 against strings of characters (letter, numbers, etc), to see if they match the
4042 string or not. The patterns are themselves (sometimes complex) strings of
4043 literal characters, combined with wild-cards, and other special characters,
4044 called meta-characters. The "meta-characters" have special meanings and are
4045 used to build complex patterns to be matched against. Perl Compatible Regular
4046 Expressions are an especially convenient "dialect" of the regular expression
4049 To make a simple analogy, we do something similar when we use wild-card
4050 characters when listing files with the dir command in DOS. *.* matches all
4051 filenames. The "special" character here is the asterisk which matches any and
4052 all characters. We can be more specific and use ? to match just individual
4053 characters. So "dir file?.text" would match "file1.txt", "file2.txt", etc. We
4054 are pattern matching, using a similar technique to "regular expressions"!
4056 Regular expressions do essentially the same thing, but are much, much more
4057 powerful. There are many more "special characters" and ways of building complex
4058 patterns however. Let's look at a few of the common ones, and then some
4061 . - Matches any single character, e.g. "a", "A", "4", ":", or "@".
4063 ? - The preceding character or expression is matched ZERO or ONE times. Either/
4066 + - The preceding character or expression is matched ONE or MORE times.
4068 * - The preceding character or expression is matched ZERO or MORE times.
4070 \ - The "escape" character denotes that the following character should be taken
4071 literally. This is used where one of the special characters (e.g. ".") needs to
4072 be taken literally and not as a special meta-character. Example: "example
4073 \.com", makes sure the period is recognized only as a period (and not expanded
4074 to its meta-character meaning of any single character).
4076 [] - Characters enclosed in brackets will be matched if any of the enclosed
4077 characters are encountered. For instance, "[0-9]" matches any numeric digit
4078 (zero through nine). As an example, we can combine this with "+" to match any
4079 digit one of more times: "[0-9]+".
4081 () - parentheses are used to group a sub-expression, or multiple
4084 | - The "bar" character works like an "or" conditional statement. A match is
4085 successful if the sub-expression on either side of "|" matches. As an example:
4086 "/(this|that) example/" uses grouping and the bar character and would match
4087 either "this example" or "that example", and nothing else.
4089 These are just some of the ones you are likely to use when matching URLs with
4090 Privoxy, and is a long way from a definitive list. This is enough to get us
4091 started with a few simple examples which may be more illuminating:
4093 /.*/banners/.* - A simple example that uses the common combination of "." and "
4094 *" to denote any character, zero or more times. In other words, any string at
4095 all. So we start with a literal forward slash, then our regular expression
4096 pattern (".*") another literal forward slash, the string "banners", another
4097 forward slash, and lastly another ".*". We are building a directory path here.
4098 This will match any file with the path that has a directory named "banners" in
4099 it. The ".*" matches any characters, and this could conceivably be more forward
4100 slashes, so it might expand into a much longer looking path. For example, this
4101 could match: "/eye/hate/spammers/banners/annoy_me_please.gif", or just "/
4102 banners/annoying.html", or almost an infinite number of other possible
4103 combinations, just so it has "banners" in the path somewhere.
4105 A now something a little more complex:
4107 /.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward
4108 slashes again ("/"), so we are building another expression that is a file path
4109 statement. We have another ".*", so we are matching against any conceivable
4110 sub-path, just so it matches our expression. The only true literal that must
4111 match our pattern is adv, together with the forward slashes. What comes after
4112 the "adv" string is the interesting part.
4114 Remember the "?" means the preceding expression (either a literal character or
4115 anything grouped with "(...)" in this case) can exist or not, since this means
4116 either zero or one match. So "((er)?ts?|ertis(ing|ements?))" is optional, as
4117 are the individual sub-expressions: "(er)", "(ing|ements?)", and the "s". The "
4118 |" means "or". We have two of those. For instance, "(ing|ements?)", can expand
4119 to match either "ing" OR "ements?". What is being done here, is an attempt at
4120 matching as many variations of "advertisement", and similar, as possible. So
4121 this would expand to match just "adv", or "advert", or "adverts", or
4122 "advertising", or "advertisement", or "advertisements". You get the idea. But
4123 it would not match "advertizements" (with a "z"). We could fix that by changing
4124 our regular expression to: "/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/", which
4125 would then match either spelling.
4127 /.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward
4128 slashes. Anything in the square brackets "[]" can be matched. This is using
4129 "0-9" as a shorthand expression to mean any digit one through nine. It is the
4130 same as saying "0123456789". So any digit matches. The "+" means one or more of
4131 the preceding expression must be included. The preceding expression here is
4132 what is in the square brackets -- in this case, any digit one through nine.
4133 Then, at the end, we have a grouping: "(gif|jpe?g)". This includes a "|", so
4134 this needs to match the expression on either side of that bar character also. A
4135 simple "gif" on one side, and the other side will in turn match either "jpeg"
4136 or "jpg", since the "?" means the letter "e" is optional and can be matched
4137 once or not at all. So we are building an expression here to match image GIF or
4138 JPEG type image file. It must include the literal string "advert", then one or
4139 more digits, and a "." (which is now a literal, and not a special character,
4140 since it is escaped with "\"), and lastly either "gif", or "jpeg", or "jpg".
4141 Some possible matches would include: "//advert1.jpg", "/nasty/ads/
4142 advert1234.gif", "/banners/from/hell/advert99.jpg". It would not match
4143 "advert1.gif" (no leading slash), or "/adverts232.jpg" (the expression does not
4144 include an "s"), or "/advert1.jsp" ("jsp" is not in the expression anywhere).
4146 We are barely scratching the surface of regular expressions here so that you
4147 can understand the default Privoxy configuration files, and maybe use this
4148 knowledge to customize your own installation. There is much, much more that can
4149 be done with regular expressions. Now that you know enough to get started, you
4150 can learn more on your own :/
4152 More reading on Perl Compatible Regular expressions: http://www.perldoc.com/
4153 perl5.6/pod/perlre.html
4155 For information on regular expression based substitutions and their
4156 applications in filters, please see the filter file tutorial in this manual.
4158 -------------------------------------------------------------------------------
4160 14.2. Privoxy's Internal Pages
4162 Since Privoxy proxies each requested web page, it is easy for Privoxy to trap
4163 certain special URLs. In this way, we can talk directly to Privoxy, and see how
4164 it is configured, see how our rules are being applied, change these rules and
4165 other configuration options, and even turn Privoxy's filtering off, all with a
4168 The URLs listed below are the special ones that allow direct access to Privoxy.
4169 Of course, Privoxy must be running to access these. If not, you will get a
4170 friendly error message. Internet access is not necessary either.
4172 * Privoxy main page:
4174 http://config.privoxy.org/
4176 There is a shortcut: http://p.p/ (But it doesn't provide a fall-back to a
4177 real page, in case the request is not sent through Privoxy)
4179 * Show information about the current configuration, including viewing and
4180 editing of actions files:
4182 http://config.privoxy.org/show-status
4184 * Show the source code version numbers:
4186 http://config.privoxy.org/show-version
4188 * Show the browser's request headers:
4190 http://config.privoxy.org/show-request
4192 * Show which actions apply to a URL and why:
4194 http://config.privoxy.org/show-url-info
4196 * Toggle Privoxy on or off. In this case, "Privoxy" continues to run, but
4197 only as a pass-through proxy, with no actions taking place:
4199 http://config.privoxy.org/toggle
4201 Short cuts. Turn off, then on:
4203 http://config.privoxy.org/toggle?set=disable
4205 http://config.privoxy.org/toggle?set=enable
4207 These may be bookmarked for quick reference. See next.
4209 -------------------------------------------------------------------------------
4211 14.2.1. Bookmarklets
4213 Below are some "bookmarklets" to allow you to easily access a "mini" version of
4214 some of Privoxy's special pages. They are designed for MS Internet Explorer,
4215 but should work equally well in Netscape, Mozilla, and other browsers which
4216 support JavaScript. They are designed to run directly from your bookmarks - not
4217 by clicking the links below (although that should work for testing).
4219 To save them, right-click the link and choose "Add to Favorites" (IE) or "Add
4220 Bookmark" (Netscape). You will get a warning that the bookmark "may not be
4221 safe" - just click OK. Then you can run the Bookmarklet directly from your
4222 favorites/bookmarks. For even faster access, you can put them on the "Links"
4223 bar (IE) or the "Personal Toolbar" (Netscape), and run them with a single
4230 * Privoxy - Toggle Privoxy (Toggles between enabled and disabled)
4232 * Privoxy- View Status
4234 * Privoxy - Submit Actions File Feedback
4238 Credit: The site which gave us the general idea for these bookmarklets is
4239 www.bookmarklets.com. They have more information about bookmarklets.
4241 -------------------------------------------------------------------------------
4243 14.3. Chain of Events
4245 Let's take a quick look at the basic sequence of events when a web page is
4246 requested by your browser and Privoxy is on duty:
4248 * First, your web browser requests a web page. The browser knows to send the
4249 request to Privoxy, which will in turn, relay the request to the remote web
4250 server after passing the following tests:
4252 * Privoxy traps any request for its own internal CGI pages (e.g http://p.p/)
4253 and sends the CGI page back to the browser.
4255 * Next, Privoxy checks to see if the URL matches any "+block" patterns. If
4256 so, the URL is then blocked, and the remote web server will not be
4257 contacted. "+handle-as-image" is then checked and if it does not match, an
4258 HTML "BLOCKED" page is sent back. Otherwise, if it does match, an image is
4259 returned. The type of image depends on the setting of "+set-image-blocker"
4260 (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
4262 * Untrusted URLs are blocked. If URLs are being added to the trust file, then
4265 * If the URL pattern matches the "+fast-redirects" action, it is then
4266 processed. Unwanted parts of the requested URL are stripped.
4268 * Now the rest of the client browser's request headers are processed. If any
4269 of these match any of the relevant actions (e.g. "+hide-user-agent", etc.),
4270 headers are suppressed or forged as determined by these actions and their
4273 * Now the web server starts sending its response back (i.e. typically a web
4274 page and related data).
4276 * First, the server headers are read and processed to determine, among other
4277 things, the MIME type (document type) and encoding. The headers are then
4278 filtered as determined by the "+crunch-incoming-cookies",
4279 "+session-cookies-only", and "+downgrade-http-version" actions.
4281 * If the "+kill-popups" action applies, and it is an HTML or JavaScript
4282 document, the popup-code in the response is filtered on-the-fly as it is
4285 * If a "+filter" or "+deanimate-gifs" action applies (and the document type
4286 fits the action), the rest of the page is read into memory (up to a
4287 configurable limit). Then the filter rules (from default.filter) are
4288 processed against the buffered content. Filters are applied in the order
4289 they are specified in the default.filter file. Animated GIFs, if present,
4290 are reduced to either the first or last frame, depending on the action
4291 setting.The entire page, which is now filtered, is then sent by Privoxy
4292 back to your browser.
4294 If neither "+filter" or "+deanimate-gifs" matches, then Privoxy passes the
4295 raw data through to the client browser as it becomes available.
4297 * As the browser receives the now (probably filtered) page content, it reads
4298 and then requests any URLs that may be embedded within the page source,
4299 e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
4300 frames), sounds, etc. For each of these objects, the browser issues a new
4301 request. And each such request is in turn processed as above. Note that a
4302 complex web page may have many such embedded URLs.
4304 -------------------------------------------------------------------------------
4306 14.4. Anatomy of an Action
4308 The way Privoxy applies actions and filters to any given URL can be complex,
4309 and not always so easy to understand what is happening. And sometimes we need
4310 to be able to see just what Privoxy is doing. Especially, if something Privoxy
4311 is doing is causing us a problem inadvertently. It can be a little daunting to
4312 look at the actions and filters files themselves, since they tend to be filled
4313 with regular expressions whose consequences are not always so obvious.
4315 One quick test to see if Privoxy is causing a problem or not, is to disable it
4316 temporarily. This should be the first troubleshooting step. See the
4317 Bookmarklets section on a quick and easy way to do this (be sure to flush
4318 caches afterward!). Looking at the logs is a good idea too.
4320 Privoxy also provides the http://config.privoxy.org/show-url-info page that can
4321 show us very specifically how actions are being applied to any given URL. This
4322 is a big help for troubleshooting.
4324 First, enter one URL (or partial URL) at the prompt, and then Privoxy will tell
4325 us how the current configuration will handle it. This will not help with
4326 filtering effects (i.e. the "+filter" action) from the default.filter file
4327 since this is handled very differently and not so easy to trap! It also will
4328 not tell you about any other URLs that may be embedded within the URL you are
4329 testing. For instance, images such as ads are expressed as URLs within the raw
4330 page source of HTML pages. So you will only get info for the actual URL that is
4331 pasted into the prompt area -- not any sub-URLs. If you want to know about
4332 embedded URLs like ads, you will have to dig those out of the HTML source. Use
4333 your browser's "View Page Source" option for this. Or right click on the ad,
4336 Let's try an example, google.com, and look at it one section at a time:
4338 Matches for http://google.com:
4340 In file: default.action [ View ] [ Edit ]
4344 -crunch-outgoing-cookies
4345 -crunch-incoming-cookies
4346 +deanimate-gifs{last}
4347 -downgrade-http-version
4351 -filter{shockwave-flash}
4352 -filter{crude-parental}
4353 +filter{html-annoyances}
4354 +filter{js-annoyances}
4355 +filter{content-cookies}
4357 +filter{refresh-tags}
4359 +filter{banners-by-size}
4360 +hide-forwarded-for-headers
4361 +hide-from-header{block}
4362 +hide-referer{forge}
4367 +prevent-compression
4370 +session-cookies-only
4371 +set-image-blocker{pattern} }
4374 { -session-cookies-only }
4380 In file: user.action [ View ] [ Edit ]
4381 (no matches in this file)
4383 This tells us how we have defined our "actions", and which ones match for our
4384 example, "google.com". The first listing is any matches for the standard.action
4385 file. No hits at all here on "standard". Then next is "default", or our
4386 default.action file. The large, multi-line listing, is how the actions are set
4387 to match for all URLs, i.e. our default settings. If you look at your "actions"
4388 file, this would be the section just below the "aliases" section near the top.
4389 This will apply to all URLs as signified by the single forward slash at the end
4390 of the listing -- "/".
4392 But we can define additional actions that would be exceptions to these general
4393 rules, and then list specific URLs (or patterns) that these exceptions would
4394 apply to. Last match wins. Just below this then are two explicit matches for
4395 ".google.com". The first is negating our previous cookie setting, which was for
4396 "+session-cookies-only" (i.e. not persistent). So we will allow persistent
4397 cookies for google. The second turns off any "+fast-redirects" action, allowing
4398 this to take place unmolested. Note that there is a leading dot here --
4399 ".google.com". This will match any hosts and sub-domains, in the google.com
4400 domain also, such as "www.google.com". So, apparently, we have these two
4401 actions defined somewhere in the lower part of our default.action file, and
4402 "google.com" is referenced somewhere in these latter sections.
4404 Then, for our user.action file, we again have no hits.
4406 And finally we pull it all together in the bottom section and summarize how
4407 Privoxy is applying all its "actions" to "google.com":
4413 -crunch-outgoing-cookies
4414 -crunch-incoming-cookies
4415 +deanimate-gifs{last}
4416 -downgrade-http-version
4420 -filter{shockwave-flash}
4421 -filter{crude-parental}
4422 +filter{html-annoyances}
4423 +filter{js-annoyances}
4424 +filter{content-cookies}
4426 +filter{refresh-tags}
4428 +filter{banners-by-size}
4429 +hide-forwarded-for-headers
4430 +hide-from-header{block}
4431 +hide-referer{forge}
4436 +prevent-compression
4439 -session-cookies-only
4440 +set-image-blocker{pattern}
4442 Notice the only difference here to the previous listing, is to "fast-redirects"
4443 and "session-cookies-only".
4445 Now another example, "ad.doubleclick.net":
4447 { +block +handle-as-image }
4450 { +block +handle-as-image }
4453 { +block +handle-as-image }
4456 We'll just show the interesting part here, the explicit matches. It is matched
4457 three different times. Each as an "+block +handle-as-image", which is the
4458 expanded form of one of our aliases that had been defined as: "+imageblock". (
4459 "Aliases" are defined in the first section of the actions file and typically
4460 used to combine more than one action.)
4462 Any one of these would have done the trick and blocked this as an unwanted
4463 image. This is unnecessarily redundant since the last case effectively would
4464 also cover the first. No point in taking chances with these guys though ;-)
4465 Note that if you want an ad or obnoxious URL to be invisible, it should be
4466 defined as "ad.doubleclick.net" is done here -- as both a "+block" and an
4467 "+handle-as-image". The custom alias "+imageblock" just simplifies the process
4468 and make it more readable.
4470 One last example. Let's try "http://www.rhapsodyk.net/adsl/HOWTO/". This one is
4471 giving us problems. We are getting a blank page. Hmmm ...
4473 Matches for http://www.rhapsodyk.net/adsl/HOWTO/:
4475 In file: default.action [ View ] [ Edit ]
4479 -crunch-incoming-cookies
4480 -crunch-outgoing-cookies
4482 -downgrade-http-version
4484 +filter{html-annoyances}
4485 +filter{js-annoyances}
4486 +filter{kill-popups}
4489 +filter{banners-by-size}
4492 +hide-forwarded-for-headers
4493 +hide-from-header{block}
4494 +hide-referer{forge}
4498 +prevent-compression
4501 +session-cookies-only
4502 +set-image-blocker{blank} }
4505 { +block +handle-as-image }
4508 Ooops, the "/adsl/" is matching "/ads"! But we did not want this at all! Now we
4509 see why we get the blank page. We could now add a new action below this that
4510 explicitly does not block ("{-block}") paths with "adsl". There are various
4511 ways to handle such exceptions. Example:
4516 Now the page displays ;-) Be sure to flush your browser's caches when making
4517 such changes. Or, try using Shift+Reload.
4519 But now what about a situation where we get no explicit matches like we did
4522 { +block +handle-as-image }
4525 That actually was very telling and pointed us quickly to where the problem was.
4526 If you don't get this kind of match, then it means one of the default rules in
4527 the first section is causing the problem. This would require some guesswork,
4528 and maybe a little trial and error to isolate the offending rule. One likely
4529 cause would be one of the "{+filter}" actions. These tend to be harder to
4530 troubleshoot. Try adding the URL for the site to one of aliases that turn off
4535 .worldpay.com # for quietpc.com
4540 "{shop}" is an "alias" that expands to "{ -filter -session-cookies-only }". Or
4541 you could do your own exception to negate filtering:
4546 This would turn off all filtering for that site. This would probably be most
4547 appropriately put in user.action, for local site exceptions.
4549 Images that are inexplicably being blocked, may well be hitting the "+filter
4550 {banners-by-size}" rule, which assumes that images of certain sizes are ad
4551 banners (works well most of the time since these tend to be standardized).
4553 "{fragile}" is an alias that disables most actions. This can be used as a last
4554 resort for problem sites. Remember to flush caches! If this still does not
4555 work, you will have to go through the remaining actions one by one to find
4556 which one(s) is causing the problem.
projects / privoxy.git / blob