1 Privoxy 3.1.1 User Manual
3 Copyright © 2001, 2002 by Privoxy Developers
5 $Id: user-manual.sgml,v 2.2 2002/09/05 05:45:30 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 alpha version of Privoxy,
182 v.3.1.1, and is mostly complete at this point. The most up to date reference
183 for the time being is still the comments in the source files and in the
184 individual configuration files. Development of version 3.0 is currently nearing
185 completion, and includes many significant changes and enhancements over earlier
186 versions. The target release date for stable v3.0 is "soon" ;-).
188 Since this is a alpha version, not all new features are well tested. This
189 documentation may be slightly out of sync as a result (especially with CVS
190 sources). And there may be bugs, though hopefully not many!
192 -------------------------------------------------------------------------------
196 In addition to Internet Junkbuster's traditional features of ad and banner
197 blocking and cookie management, Privoxy provides new features, some of them
198 currently under development:
200 * Integrated browser based configuration and control utility at http://
201 config.privoxy.org/ (shortcut: http://p.p/). Browser-based tracing of rule
202 and filter effects. Remote toggling.
204 * Web page content filtering (removes banners based on size, invisible
205 "web-bugs", JavaScript and HTML annoyances, pop-up windows, etc.)
207 * Modularized configuration that allows for standard settings and user
208 settings to reside in separate files, so that installing updated actions
209 files won't overwrite individual user settings.
211 * HTTP/1.1 compliant (but not all optional 1.1 features are supported).
213 * Support for Perl Compatible Regular Expressions in the configuration files,
214 and generally a more sophisticated and flexible configuration syntax over
217 * Improved cookie management features (e.g. session based cookies).
221 * Bypass many click-tracking scripts (avoids script redirection).
223 * Multi-threaded (POSIX and native threads).
225 * User-customizable HTML templates for all proxy-generated pages (e.g.
228 * Auto-detection and re-reading of config file changes.
230 * Improved signal handling, and a true daemon mode (Unix).
232 * Every feature now controllable on a per-site or per-location basis,
233 configuration more powerful and versatile over-all.
235 * Many smaller new features added, limitations and bugs removed, and security
238 -------------------------------------------------------------------------------
242 Privoxy is available both in convenient pre-compiled packages for a wide range
243 of operating systems, and as raw source code. For most users, we recommend
244 using the packages, which can be downloaded from our Privoxy Project Page.
246 Note: If you have a previous Junkbuster or Privoxy installation on your system,
247 you will need to remove it. On some platforms, this may be done for you as part
248 of their installation procedure. (See below for your platform). In any case be
249 sure to backup your old configuration if it is valuable to you. See the note to
250 upgraders section below.
252 -------------------------------------------------------------------------------
256 How to install the binary packages depends on your operating system:
258 -------------------------------------------------------------------------------
260 2.1.1. Red Hat, SuSE and Conectiva RPMs
262 RPMs can be installed with rpm -Uvh privoxy-3.1.1-1.rpm, and will use /etc/
263 privoxy for the location of configuration files.
265 Note that on Red Hat, Privoxy will not be automatically started on system boot.
266 You will need to enable that using chkconfig, ntsysv, or similar methods. Note
267 that SuSE will automatically start Privoxy in the boot process.
269 If you have problems with failed dependencies, try rebuilding the SRC RPM: rpm
270 --rebuild privoxy-3.1.1-1.src.rpm. This will use your locally installed
271 libraries and RPM version.
273 Also note that if you have a Junkbuster RPM installed on your system, you need
274 to remove it first, because the packages conflict. Otherwise, RPM will try to
275 remove Junkbuster automatically, before installing Privoxy.
277 -------------------------------------------------------------------------------
281 DEBs can be installed with dpkg -i privoxy_3.1.1-1.deb, and will use /etc/
282 privoxy for the location of configuration files.
284 -------------------------------------------------------------------------------
288 Just double-click the installer, which will guide you through the installation
289 process. You will find the configuration files in the same directory as you
290 installed Privoxy in. We do not use the registry of Windows.
292 -------------------------------------------------------------------------------
294 2.1.4. Solaris, NetBSD, FreeBSD, HP-UX
296 Create a new directory, cd to it, then unzip and untar the archive. For the
297 most part, you'll have to figure out where things go.
299 -------------------------------------------------------------------------------
303 First, make sure that no previous installations of Junkbuster and / or Privoxy
304 are left on your system. Check that no Junkbuster or Privoxy objects are in
307 Then, just double-click the WarpIN self-installing archive, which will guide
308 you through the installation process. A shadow of the Privoxy executable will
309 be placed in your startup folder so it will start automatically whenever OS/2
312 The directory you choose to install Privoxy into will contain all of the
315 -------------------------------------------------------------------------------
319 Unzip the downloaded file (you can either double-click on the file from the
320 finder, or from the desktop if you downloaded it there). Then, double-click on
321 the package installer icon named Privoxy.pkg and follow the installation
322 process. Privoxy will be installed in the folder /Library/Privoxy. It will
323 start automatically whenever you start up. To prevent it from starting
324 automatically, remove or rename the folder /Library/StartupItems/Privoxy.
326 To start Privoxy by hand, double-click on StartPrivoxy.command in the /Library/
327 Privoxy folder. Or, type this command in the Terminal:
329 /Library/Privoxy/StartPrivoxy.command
332 You will be prompted for the administrator password.
334 -------------------------------------------------------------------------------
338 Copy and then unpack the lha archive to a suitable location. All necessary
339 files will be installed into Privoxy directory, including all configuration and
340 log files. To uninstall, just remove this directory.
342 -------------------------------------------------------------------------------
346 Gentoo source packages (Ebuilds) for Privoxy are contained in the Gentoo
347 Portage Tree (they are not on the download page, but there is a Gentoo section,
348 where you can see when a new Privoxy Version is added to the Portage Tree).
350 Before installing Privoxy under Gentoo just do first emerge rsync to get the
351 latest changes from the Portage tree. With emerge privoxy you install the
354 Configuration files are in /etc/privoxy, the documentation is in /usr/share/doc
355 /privoxy-3.1.1 and the Log directory is in /var/log/privoxy.
357 -------------------------------------------------------------------------------
359 2.2. Building from Source
361 The most convenient way to obtain the Privoxy sources is to download the source
362 tarball from our project page.
364 If you like to live on the bleeding edge and are not afraid of using possibly
365 unstable development versions, you can check out the up-to-the-minute version
366 directly from the CVS repository or simply download the nightly CVS tarball.
368 To build Privoxy from source, autoconf, GNU make (gmake), and, of course, a C
369 compiler like gcc are required.
371 When building from a source tarball (either release version or nightly CVS
372 tarball), first unpack the source:
374 tar xzvf privoxy-3.1.1-beta-src* [.tgz or .tar.gz]
375 cd privoxy-3.1.1-beta
377 For retrieving the current CVS sources, you'll need CVS installed. Note that
378 sources from CVS are development quality, and may not be stable, or well
379 tested. To download CVS source:
381 cvs -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa login
382 cvs -z3 -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa co current
385 This will create a directory named current/, which will contain the source
388 Then, in either case, to build from unpacked tarball or CVS source:
392 ./configure # (--help to see options)
393 make # (the make from gnu, gmake for *BSD)
395 make -n install # (to see where all the files will go)
396 make install # (to really install)
398 +-----------------------------------------------------------------------------+
400 |-----------------------------------------------------------------------------|
401 |The "make install" target is temporary quite broken! It is recommended to use|
402 |a binary package, or do a source build, and manually install the components. |
404 +-----------------------------------------------------------------------------+
406 If you have gnu make, you can have the first four steps automatically done for
411 in the freshly downloaded or unpacked source directory.
413 For more detailed instructions on how to build Redhat and SuSE RPMs, Windows
414 self-extracting installers, building on platforms with special requirements
415 etc, please consult the developer manual.
417 -------------------------------------------------------------------------------
419 2.3. Keeping your Installation Up-to-Date
421 As user feedback comes in and development continues, we will make updated
422 versions of both the main actions file (as a separate package) and the software
423 itself (including the actions file) available for download.
425 If you wish to receive an email notification whenever we release updates of
426 Privoxy or the actions file, subscribe to our announce mailing list,
427 ijbswa-announce@lists.sourceforge.net.
429 In order not to loose your personal changes and adjustments when updating to
430 the latest default.action file we strongly recommend that you use user.action
431 for your customization of Privoxy. See the Chapter on actions files for
434 -------------------------------------------------------------------------------
438 There are very significant changes from earlier Junkbuster versions to the
439 current Privoxy. The number, names, syntax, and purposes of configuration files
440 have substantially changed. Junkbuster 2.0.x configuration files will not
441 migrate, Junkbuster 2.9.x and Privoxy configurations will need to be ported.
442 The functionalities of the old blockfile, cookiefile and imagelist are now
443 combined into the "actions files". default.action, is the main actions file.
444 Local exceptions should best be put into user.action.
446 A "filter file" (typically default.filter) is new as of Privoxy 2.9.x, and
447 provides some of the new sophistication (explained below). config is much the
450 If upgrading from a 2.0.x version, you will have to use the new config files,
451 and possibly adapt any personal rules from your older files. When porting
452 personal rules over from the old blockfile to the new actions files, please
453 note that even the pattern syntax has changed. If upgrading from 2.9.x
454 development versions, it is still recommended to use the new configuration
457 A quick list of things to be aware of before upgrading:
459 * The default listening port is now 8118 due to a conflict with another
462 * Some installers may remove earlier versions completely. Save any important
465 * Privoxy is controllable with a web browser at the special URL: http://
466 config.privoxy.org/ (Shortcut: http://p.p/). Many aspects of configuration
467 can be done here, including temporarily disabling Privoxy.
469 * The primary configuration files for cookie management, ad and banner
470 blocking, and many other aspects of Privoxy configuration are the actions
471 files. It is strongly recommended to become familiar with the new actions
472 concept below, before modifying these files. Locally defined rules should
475 * Some installers may not automatically start Privoxy after installation.
477 -------------------------------------------------------------------------------
479 4. Quickstart to Using Privoxy
481 * If upgrading, from versions before 2.9.16, please back up any configuration
482 files. See the Note to Upgraders Section.
484 * Install Privoxy. See the Installation Section below for platform specific
487 * Advanced users and those who want to offer Privoxy service to more than
488 just their local machine should check the main config file, especially the
489 security-relevant options. These are off by default.
491 * Start Privoxy, if the installation program has not done this already (may
492 vary according to platform). See the section Starting Privoxy.
494 * Set your browser to use Privoxy as HTTP and HTTPS proxy by setting the
495 proxy configuration for address of 127.0.0.1 and port 8118. (Junkbuster and
496 earlier versions of Privoxy used port 8000.) See the section Starting
497 Privoxy below for more details on this.
499 * Flush your browser's disk and memory caches, to remove any cached ad
502 * A default installation should provide a reasonable starting point for most.
503 There will undoubtedly be occasions where you will want to adjust the
504 configuration, but that can be dealt with as the need arises. Little to no
505 initial configuration is required in most cases.
507 See the Configuration section for more configuration options, and how to
508 customize your installation.
510 * If you experience ads that slipped through, innocent images that are
511 blocked, or otherwise feel the need to fine-tune Privoxy's behaviour, take
512 a look at the actions files. As a quick start, you might find the richly
513 commented examples helpful. You can also view and edit the actions files
514 through the web-based user interface. The Appendix "Anatomy of an Action"
515 has hints how to debug actions that "misbehave".
517 * Please see the section Contacting the Developers on how to report bugs or
518 problems with websites or to get help.
520 * Now enjoy surfing with enhanced comfort and privacy!
522 -------------------------------------------------------------------------------
524 4.1. Quickstart to Ad Blocking
526 Ad blocking is but one of Privoxy's array of features. Many of these features
527 are for the technically minded advanced user. But, ad and banner blocking is
528 surely common ground for everybody.
530 This section will provide a quick summary of ad blocking so you can get up to
531 speed quickly without having to read the more extensive information provided
532 below, though this is highly recommended.
534 First a bit of a warning ... blocking ads is much like blocking SPAM: the more
535 aggressive you are about it, the more likely you are to block things that were
536 not intended. So there is a trade off here. If you want extreme ad free
537 browsing, be prepared to deal with more "problem" sites, and to spend more time
538 adjusting the configuration to solve these unintended consequences. In short,
539 there is not an easy way to eliminate all ads. Either take the easy way and
540 settle for most ads blocked with the default configuration, or jump in and
541 tweak it for your personal surfing habits and preferences.
543 Secondly, a brief explanation of Privoxy's "actions". "Actions" in this
544 context, are the directives we use to tell Privoxy to perform some task
545 relating to HTTP transactions (i.e. web browsing). We tell Privoxy to take some
546 "action". Each action has a unique name and function. While there are many
547 potential actions in Privoxy's arsenal, only a few are used for ad blocking.
548 Actions, and action configuration files, are explained in depth below.
550 Actions are specified in Privoxy's configuration, followed by one or more URLs
551 to which the action should apply. URLs can actually be URL type patterns that
552 use wildcards so they can apply potentially to a range of similar URLs. The
553 actions, together with the URL patterns are called a section.
555 When you connect to a website, the full URL will either match one or more of
556 the sections as defined in Privoxy's configuration, or not. If so, then Privoxy
557 will perform the respective actions. If not, then nothing special happens.
558 Furthermore, web pages may contain embedded, secondary URLs that your web
559 browser will use to load additional components of the page, as it parses the
560 original page's HTML content. An ad image for instance, is just an URL embedded
561 in the page somewhere. The image itself may be on the same server, or a server
562 somewhere else on the Internet. Complex web pages will have many such embedded
565 The actions we need to know about for ad blocking are: block, handle-as-image,
566 and set-image-blocker:
568 * block - this action stops any contact between your browser and any URL
569 patterns that match this action's configuration. It can be used for
570 blocking ads, but also anything that is determined to be unwanted. By
571 itself, it simply stops any communication with the remote server and sends
572 Privoxy's own built-in BLOCKED page instead to let you now what has
575 * handle-as-image - tells Privoxy to treat this URL as an image. Privoxy's
576 default configuration already does this for all common image types (e.g.
577 GIF), but there are many situations where this is not so easy to determine.
578 So we'll force it in these cases. This is particularly important for ad
579 blocking, since only if we know that it's an image of some kind, can we
580 replace it with an image of our choosing, instead of the Privoxy BLOCKED
581 page (which would only result in a "broken image" icon). There are some
582 limitations to this though. For instance, you can't just brute-force an
583 image substitution for an entire HTML page in most situations.
585 * set-image-blocker - tells Privoxy what to display in place of an ad image
586 that has hit a block rule. For this to come into play, the URL must match a
587 block action somewhere in the configuration, and, it must also match an
588 handle-as-image action.
590 The configuration options on what to display instead of the ad are:
592 pattern - a checkerboard pattern, so that an ad replacement is obvious.
595 blank - A very small empty GIF image is displayed. This is the so-called
596 "invisible" configuration option.
598 http://<URL> - A redirect to any image anywhere of the user's choosing
601 The quickest way to adjust any of these settings is with your browser through
602 the special Privoxy editor at http://config.privoxy.org/show-status (shortcut:
603 http://p.p/show-status). This is an internal page, and does not require
604 Internet access. Select the appropriate "actions" file, and click "Edit". It is
605 best to put personal or local preferences in user.action since this is not
606 meant to be overwritten during upgrades, and will over-ride the settings in
607 other files. Here you can insert new "actions", and URLs for ad blocking or
608 other purposes, and make other adjustments to the configuration. Privoxy will
609 detect these changes automatically.
611 A quick and simple step by step example:
613 * Right click on the ad image to be blocked, then select "Copy Link Location"
614 from the pop-up menu.
616 * Set your browser to http://config.privoxy.org/show-status
618 * Find user.action in the top section, and click on "Edit":
620 Figure 1. Actions Files in Use
624 * You should have a section with only block listed under "Actions:". If not,
625 click a "Insert new section below" button, and in the new section that just
626 appeared, click the Edit button right under the word "Actions:". This will
627 bring up a list of all actions. Find block near the top, and click in the
628 "Enabled" column, then "Submit" just below the list.
630 * Now, in the block actions section, click the "Add" button, and paste the
631 URL the browser got from "Copy Link Location". Remove the http:// at the
632 beginning of the URL. Then, click "Submit" (or "OK" if in a pop-up window).
634 * Now go back to the original page, and press SHIFT-Reload (or flush all
635 browser caches). The image should be gone now.
637 This is a very crude and simple example. There might be good reasons to use a
638 wildcard pattern match to include potentially similar images from the same
639 site. For a more extensive explanation of "patterns", and the entire actions
640 concept, see the Actions section.
642 For advanced users who want to hand edit their config files, you might want to
643 now go to the Actions Files Tutorial. The ideas explained therein also apply to
644 the web-based editor.
646 -------------------------------------------------------------------------------
650 Before launching Privoxy for the first time, you will want to configure your
651 browser(s) to use Privoxy as a HTTP and HTTPS proxy. The default is 127.0.0.1
652 (or localhost) for the proxy address, and port 8118 (earlier versions used port
653 8000). This is the one configuration step that must be done!
655 Please note that Privoxy can only proxy HTTP and HTTPS traffic. It will not
656 work with FTP or other protocols.
658 Figure 2. Proxy Configuration (Mozilla)
662 With Netscape (and Mozilla), this can be set under:
674 For Internet Explorer:
684 Then, check "Use Proxy" and fill in the appropriate info (Address: 127.0.0.1,
685 Port: 8118). Include HTTPS (SSL), if you want HTTPS proxy support too.
687 After doing this, flush your browser's disk and memory caches to force a
688 re-reading of all pages and to get rid of any ads that may be cached. You are
689 now ready to start enjoying the benefits of using Privoxy!
691 Privoxy is typically started by specifying the main configuration file to be
692 used on the command line. If no configuration file is specified on the command
693 line, Privoxy will look for a file named config in the current directory.
694 Except on Win32 where it will try config.txt.
696 -------------------------------------------------------------------------------
698 5.1. Red Hat and Conectiva
700 We use a script. Note that Red Hat does not start Privoxy upon booting per
701 default. It will use the file /etc/privoxy/config as its main configuration
704 # /etc/rc.d/init.d/privoxy start
706 -------------------------------------------------------------------------------
710 We use a script. Note that Debian starts Privoxy upon booting per default. It
711 will use the file /etc/privoxy/config as its main configuration file.
713 # /etc/init.d/privoxy start
715 -------------------------------------------------------------------------------
719 We use a script. It will use the file /etc/privoxy/config as its main
720 configuration file. Note that SuSE starts Privoxy upon booting your PC.
724 -------------------------------------------------------------------------------
728 Click on the Privoxy Icon to start Privoxy. If no configuration file is
729 specified on the command line, Privoxy will look for a file named config.txt.
730 Note that Windows will automatically start Privoxy upon booting you PC.
732 -------------------------------------------------------------------------------
734 5.5. Solaris, NetBSD, FreeBSD, HP-UX and others
736 Example Unix startup command:
738 # /usr/sbin/privoxy /etc/privoxy/config
740 -------------------------------------------------------------------------------
744 During installation, Privoxy is configured to start automatically when the
745 system restarts. You can start it manually by double-clicking on the Privoxy
746 icon in the Privoxy folder.
748 -------------------------------------------------------------------------------
752 During installation, Privoxy is configured to start automatically when the
753 system restarts. To start Privoxy by hand, double-click on the
754 StartPrivoxy.command icon in the /Library/Privoxy folder. Or, type this command
757 /Library/Privoxy/StartPrivoxy.command
760 You will be prompted for the administrator password.
762 -------------------------------------------------------------------------------
766 Start Privoxy (with RUN <>NIL:) in your startnet script (AmiTCP), in s:
767 user-startup (RoadShow), as startup program in your startup script (Genesis),
768 or as startup action (Miami and MiamiDx). Privoxy will automatically quit when
769 you quit your TCP/IP stack (just ignore the harmless warning your TCP/IP stack
770 may display that Privoxy is still running).
772 -------------------------------------------------------------------------------
776 A script is again used. It will use the file /etc/privoxy/config as its main
779 /etc/init.d/privoxy start
782 Note that Privoxy is not automatically started at boot time by default. You can
783 change this with the rc-update command.
785 rc-update add privoxy default
788 -------------------------------------------------------------------------------
790 5.10. Command Line Options
792 Privoxy may be invoked with the following command-line options:
796 Print version info and exit. Unix only.
800 Print short usage info and exit. Unix only.
804 Don't become a daemon, i.e. don't fork and become process group leader, and
805 don't detach from controlling tty. Unix only.
809 On startup, write the process ID to FILE. Delete the FILE on exit. Failure
810 to create or delete the FILE is non-fatal. If no FILE option is given, no
811 PID file will be used. Unix only.
813 * --user USER[.GROUP]
815 After (optionally) writing the PID file, assume the user ID of USER, and if
816 included the GID of GROUP. Exit if the privileges are not sufficient to do
821 If no configfile is included on the command line, Privoxy will look for a
822 file named "config" in the current directory (except on Win32 where it will
823 look for "config.txt" instead). Specify full path to avoid confusion. If no
824 config file is found, Privoxy will fail to start.
826 -------------------------------------------------------------------------------
828 6. Privoxy Configuration
830 All Privoxy configuration is stored in text files. These files can be edited
831 with a text editor. Many important aspects of Privoxy can also be controlled
832 easily with a web browser.
834 -------------------------------------------------------------------------------
836 6.1. Controlling Privoxy with Your Web Browser
838 Privoxy's user interface can be reached through the special URL http://
839 config.privoxy.org/ (shortcut: http://p.p/), which is a built-in page and works
840 without Internet access. You will see the following section:
843 ? View & change the current configuration
844 ? View the source code version numbers
845 ? View the request headers.
846 ? Look up which actions apply to a URL and why
847 ? Toggle Privoxy on or off
851 This should be self-explanatory. Note the first item leads to an editor for the
852 actions files, which is where the ad, banner, cookie, and URL blocking magic is
853 configured as well as other advanced features of Privoxy. This is an easy way
854 to adjust various aspects of Privoxy configuration. The actions file, and other
855 configuration files, are explained in detail below.
857 "Toggle Privoxy On or Off" is handy for sites that might have problems with
858 your current actions and filters. You can in fact use it as a test to see
859 whether it is Privoxy causing the problem or not. Privoxy continues to run as a
860 proxy in this case, but all manipulation is disabled, i.e. Privoxy acts like a
861 normal forwarding proxy. There is even a toggle Bookmarklet offered, so that
862 you can toggle Privoxy with one click from your browser.
864 -------------------------------------------------------------------------------
866 6.2. Configuration Files Overview
868 For Unix, *BSD and Linux, all configuration files are located in /etc/privoxy/
869 by default. For MS Windows, OS/2, and AmigaOS these are all in the same
870 directory as the Privoxy executable. The name and number of configuration files
871 has changed from previous versions, and is subject to change as development
874 The installed defaults provide a reasonable starting point, though some
875 settings may be aggressive by some standards. For the time being, the principle
876 configuration files are:
878 * The main configuration file is named config on Linux, Unix, BSD, OS/2, and
879 AmigaOS and config.txt on Windows. This is a required file.
881 * default.action (the main actions file) is used to define which "actions"
882 relating to banner-blocking, images, pop-ups, content modification, cookie
883 handling etc should be applied by default. It also defines many exceptions
884 (both positive and negative) from this default set of actions that enable
885 Privoxy to selectively eliminate the junk, and only the junk, on as many
886 websites as possible.
888 Multiple actions files may be defined in config. These are processed in the
889 order they are defined. Local customizations and locally preferred
890 exceptions to the default policies as defined in default.action (which you
891 will most probably want to define sooner or later) are probably best
892 applied in user.action, where you can preserve them across upgrades.
893 standard.action is for Privoxy's internal use.
895 There is also a web based editor that can be accessed from http://
896 config.privoxy.org/show-status (Shortcut: http://p.p/show-status) for the
897 various actions files.
899 * default.filter (the filter file) can be used to re-write the raw page
900 content, including viewable text as well as embedded HTML and JavaScript,
901 and whatever else lurks on any given web page. The filtering jobs are only
902 pre-defined here; whether to apply them or not is up to the actions files.
904 All files use the "#" character to denote a comment (the rest of the line will
905 be ignored) and understand line continuation through placing a backslash ("\")
906 as the very last character in a line. If the # is preceded by a backslash, it
907 looses its special function. Placing a # in front of an otherwise valid
908 configuration line to prevent it from being interpreted is called "commenting
911 The actions files and default.filter can use Perl style regular expressions for
914 After making any changes, there is no need to restart Privoxy in order for the
915 changes to take effect. Privoxy detects such changes automatically. Note,
916 however, that it may take one or two additional requests for the change to take
917 effect. When changing the listening address of Privoxy, these "wake up"
918 requests must obviously be sent to the old listening address.
920 While under development, the configuration content is subject to change. The
921 below documentation may not be accurate by the time you read this. Also, what
922 constitutes a "default" setting, may change, so please check all your
923 configuration files on important issues.
925 -------------------------------------------------------------------------------
927 7. The Main Configuration File
929 Again, the main configuration file is named config on Linux/Unix/BSD and OS/2,
930 and config.txt on Windows. Configuration lines consist of an initial keyword
931 followed by a list of values, all separated by whitespace (any number of spaces
932 or tabs). For example:
936 Assigns the value /etc/privoxy to the option confdir and thus indicates that
937 the configuration directory is named "/etc/privoxy/".
939 All options in the config file except for confdir and logdir are optional.
940 Watch out in the below description for what happens if you leave them unset.
942 The main config file controls all aspects of Privoxy's operation that are not
943 location dependent (i.e. they apply universally, no matter where you may be
946 -------------------------------------------------------------------------------
948 7.1. Configuration and Log File Locations
950 Privoxy can (and normally does) use a number of other files for additional
951 configuration, help and logging. This section of the configuration file tells
952 Privoxy where to find those other files.
954 The user running Privoxy, must have read permission for all configuration
955 files, and write permission to any files that would be modified, such as log
956 files and actions files.
958 -------------------------------------------------------------------------------
964 The directory where the other configuration files are located
972 /etc/privoxy (Unix) or Privoxy installation dir (Windows)
980 No trailing "/", please
982 When development goes modular and multi-user, the blocker, filter, and
983 per-user config will be stored in subdirectories of "confdir". For now, the
984 configuration directory structure is flat, except for confdir/templates,
985 where the HTML templates for CGI output reside (e.g. Privoxy's 404 error
988 -------------------------------------------------------------------------------
994 The directory where all logging takes place (i.e. where logfile and jarfile
1003 /var/log/privoxy (Unix) or Privoxy installation dir (Windows)
1011 No trailing "/", please
1013 -------------------------------------------------------------------------------
1019 The actions file(s) to use
1023 File name, relative to confdir, without the .action suffix
1027 standard # Internal purposes, no editing recommended
1029 default # Main actions file
1031 user # User customizations
1035 No actions are taken at all. Simple neutral proxying.
1039 Multiple actionsfile lines are permitted, and are in fact recommended!
1041 The default values include standard.action, which is used for internal
1042 purposes and should be loaded, default.action, which is the "main" actions
1043 file maintained by the developers, and user.action, where you can make your
1046 Actions files are where all the per site and per URL configuration is done
1047 for ad blocking, cookie management, privacy considerations, etc. There is
1048 no point in using Privoxy without at least one actions file.
1050 -------------------------------------------------------------------------------
1056 The filter file to use
1060 File name, relative to confdir
1064 default.filter (Unix) or default.filter.txt (Windows)
1068 No textual content filtering takes place, i.e. all +filter{name} actions in
1069 the actions files are turned neutral.
1073 The filter file contains content modification rules that use regular
1074 expressions. These rules permit powerful changes on the content of Web
1075 pages, e.g., you could disable your favorite JavaScript annoyances,
1076 re-write the actual displayed text, or just have some fun replacing
1077 "Microsoft" with "MicroSuck" wherever it appears on a Web page.
1079 The +filter{name} actions rely on the relevant filter (name) to be defined
1082 A pre-defined filter file called default.filter that contains a bunch of
1083 handy filters for common problems is included in the distribution. See the
1084 section on the filter action for a list.
1086 -------------------------------------------------------------------------------
1096 File name, relative to logdir
1100 logfile (Unix) or privoxy.log (Windows)
1104 No log file is used, all log messages go to the console (STDERR).
1108 The windows version will additionally log to the console.
1110 The logfile is where all logging and error messages are written. The level
1111 of detail and number of messages are set with the debug option (see below).
1112 The logfile can be useful for tracking down a problem with Privoxy (e.g.,
1113 it's not blocking an ad you think it should block) but in most cases you
1114 probably will never look at it.
1116 Your logfile will grow indefinitely, and you will probably want to
1117 periodically remove it. On Unix systems, you can do this with a cron job
1118 (see "man cron"). For Red Hat, a logrotate script has been included.
1120 On SuSE Linux systems, you can place a line like "/var/log/privoxy.* +1024k
1121 644 nobody.nogroup" in /etc/logfiles, with the effect that cron.daily will
1122 automatically archive, gzip, and empty the log, when it exceeds 1M size.
1124 Any log files must be writable by whatever user Privoxy is being run as
1125 (default on UNIX, user id is "privoxy").
1127 -------------------------------------------------------------------------------
1133 The file to store intercepted cookies in
1137 File name, relative to logdir
1141 jarfile (Unix) or privoxy.jar (Windows)
1145 Intercepted cookies are not stored at all.
1149 The jarfile may grow to ridiculous sizes over time.
1151 -------------------------------------------------------------------------------
1157 The trust file to use
1161 File name, relative to confdir
1165 Unset (commented out). When activated: trust (Unix) or trust.txt (Windows)
1169 The whole trust mechanism is turned off.
1173 The trust mechanism is an experimental feature for building white-lists and
1174 should be used with care. It is NOT recommended for the casual user.
1176 If you specify a trust file, Privoxy will only allow access to sites that
1177 are named in the trustfile. You can also mark sites as trusted referrers
1178 (with +), with the effect that access to untrusted sites will be granted,
1179 if a link from a trusted referrer was used. The link target will then be
1180 added to the "trustfile". Possible applications include limiting Internet
1181 access for children.
1183 If you use + operator in the trust file, it may grow considerably over
1186 -------------------------------------------------------------------------------
1188 7.2. Local Set-up Documentation
1190 If you intend to operate Privoxy for more users than just yourself, it might be
1191 a good idea to let them know how to reach you, what you block and why you do
1192 that, your policies, etc.
1194 -------------------------------------------------------------------------------
1200 Location of the Privoxy User Manual.
1204 A fully qualified URI
1212 http://www.privoxy.org/version/user-manual/ will be used, where version is
1213 the Privoxy version.
1217 The User Manual URI is used for help links from some of the internal CGI
1218 pages. The manual itself is normally packaged with the binary
1219 distributions, so you probably want to set this to a locally installed
1220 copy. For multi-user setups, you could provide a copy on a local webserver
1221 for all your users and use the corresponding URL here.
1225 Unix, in local filesystem:
1227 user-manual file:///usr/share/doc/privoxy-3.1.1/user-manual/
1229 Any platform, on local webserver (called "local-webserver"):
1231 user-manual http://local-webserver/privoxy-user-manual/
1233 +-----------------------------------------------------------------+
1235 |-----------------------------------------------------------------|
1236 |If set, this option should be the first option in the config |
1237 |file, because it is used while the config file is being read. |
1238 +-----------------------------------------------------------------+
1240 -------------------------------------------------------------------------------
1242 7.2.2. trust-info-url
1246 A URL to be displayed in the error page that users will see if access to an
1247 untrusted page is denied.
1255 Two example URL are provided
1259 No links are displayed on the "untrusted" error page.
1263 The value of this option only matters if the experimental trust mechanism
1264 has been activated. (See trustfile above.)
1266 If you use the trust mechanism, it is a good idea to write up some on-line
1267 documentation about your trust policy and to specify the URL(s) here. Use
1268 multiple times for multiple URLs.
1270 The URL(s) should be added to the trustfile as well, so users don't end up
1271 locked out from the information on why they were locked out in the first
1274 -------------------------------------------------------------------------------
1276 7.2.3. admin-address
1280 An email address to reach the proxy administrator.
1292 No email address is displayed on error pages and the CGI user interface.
1296 If both admin-address and proxy-info-url are unset, the whole "Local
1297 Privoxy Support" box on all generated pages will not be shown.
1299 -------------------------------------------------------------------------------
1301 7.2.4. proxy-info-url
1305 A URL to documentation about the local Privoxy setup, configuration or
1318 No link to local documentation is displayed on error pages and the CGI user
1323 If both admin-address and proxy-info-url are unset, the whole "Local
1324 Privoxy Support" box on all generated pages will not be shown.
1326 This URL shouldn't be blocked ;-)
1328 -------------------------------------------------------------------------------
1332 These options are mainly useful when tracing a problem. Note that you might
1333 also want to invoke Privoxy with the --no-daemon command line option when
1336 -------------------------------------------------------------------------------
1342 Key values that determine what information gets logged to the logfile.
1350 12289 (i.e.: URLs plus informational and warning messages)
1354 Nothing gets logged.
1358 The available debug levels are:
1360 debug 1 # show each GET/POST/CONNECT request
1361 debug 2 # show each connection status
1362 debug 4 # show I/O status
1363 debug 8 # show header parsing
1364 debug 16 # log all data into the logfile
1365 debug 32 # debug force feature
1366 debug 64 # debug regular expression filter
1367 debug 128 # debug fast redirects
1368 debug 256 # debug GIF de-animation
1369 debug 512 # Common Log Format
1370 debug 1024 # debug kill pop-ups
1371 debug 2048 # CGI user interface
1372 debug 4096 # Startup banner and warnings.
1373 debug 8192 # Non-fatal errors
1375 To select multiple debug levels, you can either add them or use multiple
1378 A debug level of 1 is informative because it will show you each request as
1379 it happens. 1, 4096 and 8192 are highly recommended so that you will notice
1380 when things go wrong. The other levels are probably only of interest if you
1381 are hunting down a specific problem. They can produce a hell of an output
1384 The reporting of fatal errors (i.e. ones which crash Privoxy) is always on
1385 and cannot be disabled.
1387 If you want to use CLF (Common Log Format), you should set "debug 512" ONLY
1388 and not enable anything else.
1390 -------------------------------------------------------------------------------
1392 7.3.2. single-threaded
1396 Whether to run only one server thread
1408 Multi-threaded (or, where unavailable: forked) operation, i.e. the ability
1409 to serve multiple requests simultaneously.
1413 This option is only there for debug purposes and you should never need to
1414 use it. It will drastically reduce performance.
1416 -------------------------------------------------------------------------------
1418 7.4. Access Control and Security
1420 This section of the config file controls the security-relevant aspects of
1421 Privoxy's configuration.
1423 -------------------------------------------------------------------------------
1425 7.4.1. listen-address
1429 The IP address and TCP port on which Privoxy will listen for client
1442 Bind to 127.0.0.1 (localhost), port 8118. This is suitable and recommended
1443 for home users who run Privoxy on the same machine as their browser.
1447 You will need to configure your browser(s) to this proxy address and port.
1449 If you already have another service running on port 8118, or if you want to
1450 serve requests from other machines (e.g. on your local network) as well,
1451 you will need to override the default.
1453 If you leave out the IP address, Privoxy will bind to all interfaces
1454 (addresses) on your machine and may become reachable from the Internet. In
1455 that case, consider using access control lists (ACL's, see below), and/or a
1458 If you open Privoxy to untrusted users, you will also want to turn off the
1459 enable-edit-actions and enable-remote-toggle options!
1463 Suppose you are running Privoxy on a machine which has the address
1464 192.168.0.1 on your local private network (192.168.0.0) and has another
1465 outside connection with a different address. You want it to serve requests
1468 listen-address 192.168.0.1:8118
1470 -------------------------------------------------------------------------------
1476 Initial state of "toggle" status
1488 Act as if toggled on
1492 If set to 0, Privoxy will start in "toggled off" mode, i.e. behave like a
1493 normal, content-neutral proxy where all ad blocking, filtering, etc are
1494 disabled. See enable-remote-toggle below. This is not really useful
1495 anymore, since toggling is much easier via the web interface than via
1496 editing the conf file.
1498 The windows version will only display the toggle icon in the system tray if
1499 this option is present.
1501 -------------------------------------------------------------------------------
1503 7.4.3. enable-remote-toggle
1507 Whether or not the web-based toggle feature may be used
1519 The web-based toggle feature is disabled.
1523 When toggled off, Privoxy acts like a normal, content-neutral proxy, i.e.
1524 it acts as if none of the actions applied to any URL.
1526 For the time being, access to the toggle feature can not be controlled
1527 separately by "ACLs" or HTTP authentication, so that everybody who can
1528 access Privoxy (see "ACLs" and listen-address above) can toggle it for all
1529 users. So this option is not recommended for multi-user environments with
1532 Note that you must have compiled Privoxy with support for this feature,
1533 otherwise this option has no effect.
1535 -------------------------------------------------------------------------------
1537 7.4.4. enable-edit-actions
1541 Whether or not the web-based actions file editor may be used
1553 The web-based actions file editor is disabled.
1557 For the time being, access to the editor can not be controlled separately
1558 by "ACLs" or HTTP authentication, so that everybody who can access Privoxy
1559 (see "ACLs" and listen-address above) can modify its configuration for all
1560 users. So this option is not recommended for multi-user environments with
1563 Note that you must have compiled Privoxy with support for this feature,
1564 otherwise this option has no effect.
1566 -------------------------------------------------------------------------------
1568 7.4.5. ACLs: permit-access and deny-access
1572 Who can access what.
1576 src_addr[/src_masklen] [dst_addr[/dst_masklen]]
1578 Where src_addr and dst_addr are IP addresses in dotted decimal notation or
1579 valid DNS names, and src_masklen and dst_masklen are subnet masks in CIDR
1580 notation, i.e. integer values from 2 to 30 representing the length (in
1581 bits) of the network address. The masks and the whole destination part are
1590 Don't restrict access further than implied by listen-address
1594 Access controls are included at the request of ISPs and systems
1595 administrators, and are not usually needed by individual users. For a
1596 typical home user, it will normally suffice to ensure that Privoxy only
1597 listens on the localhost (127.0.0.1) or internal (home) network address by
1598 means of the listen-address option.
1600 Please see the warnings in the FAQ that this proxy is not intended to be a
1601 substitute for a firewall or to encourage anyone to defer addressing basic
1602 security weaknesses.
1604 Multiple ACL lines are OK. If any ACLs are specified, then the Privoxy
1605 talks only to IP addresses that match at least one permit-access line and
1606 don't match any subsequent deny-access line. In other words, the last match
1607 wins, with the default being deny-access.
1609 If Privoxy is using a forwarder (see forward below) for a particular
1610 destination URL, the dst_addr that is examined is the address of the
1611 forwarder and NOT the address of the ultimate target. This is necessary
1612 because it may be impossible for the local Privoxy to determine the IP
1613 address of the ultimate target (that's often what gateways are used for).
1615 You should prefer using IP addresses over DNS names, because the address
1616 lookups take time. All DNS names must resolve! You can not use domain
1617 patterns like "*.org" or partial domain names. If a DNS name resolves to
1618 multiple IP addresses, only the first one is used.
1620 Denying access to particular sites by ACL may have undesired side effects
1621 if the site in question is hosted on a machine which also hosts other
1626 Explicitly define the default behavior if no ACL and listen-address are
1627 set: "localhost" is OK. The absence of a dst_addr implies that all
1628 destination addresses are OK:
1630 permit-access localhost
1632 Allow any host on the same class C subnet as www.privoxy.org access to
1633 nothing but www.example.com:
1635 permit-access www.privoxy.org/24 www.example.com/32
1637 Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere,
1638 with the exception that 192.168.45.73 may not access
1639 www.dirty-stuff.example.com:
1641 permit-access 192.168.45.64/26
1642 deny-access 192.168.45.73 www.dirty-stuff.example.com
1644 -------------------------------------------------------------------------------
1650 Maximum size of the buffer for content filtering.
1662 Use a 4MB (4096 KB) limit.
1666 For content filtering, i.e. the +filter and +deanimate-gif actions, it is
1667 necessary that Privoxy buffers the entire document body. This can be
1668 potentially dangerous, since a server could just keep sending data
1669 indefinitely and wait for your RAM to exhaust -- with nasty consequences.
1672 When a document buffer size reaches the buffer-limit, it is flushed to the
1673 client unfiltered and no further attempt to filter the rest of the document
1674 is made. Remember that there may be multiple threads running, which might
1675 require up to buffer-limit Kbytes each, unless you have enabled
1676 "single-threaded" above.
1678 -------------------------------------------------------------------------------
1682 This feature allows routing of HTTP requests through a chain of multiple
1683 proxies. It can be used to better protect privacy and confidentiality when
1684 accessing specific domains by routing requests to those domains through an
1685 anonymous public proxy (see e.g. http://www.multiproxy.org/anon_list.htm) Or to
1686 use a caching proxy to speed up browsing. Or chaining to a parent proxy may be
1687 necessary because the machine that Privoxy runs on has no direct Internet
1690 Also specified here are SOCKS proxies. Privoxy supports the SOCKS 4 and SOCKS
1693 -------------------------------------------------------------------------------
1699 To which parent HTTP proxy specific requests should be routed.
1703 target_pattern http_parent[:port]
1705 where target_pattern is a URL pattern that specifies to which requests
1706 (i.e. URLs) this forward rule shall apply. Use / to denote "all URLs".
1707 http_parent[:port] is the DNS name or IP address of the parent HTTP proxy
1708 through which the requests should be forwarded, optionally followed by its
1709 listening port (default: 8080). Use a single dot (.) to denote "no
1718 Don't use parent HTTP proxies.
1722 If http_parent is ".", then requests are not forwarded to another HTTP
1723 proxy but are made directly to the web servers.
1725 Multiple lines are OK, they are checked in sequence, and the last match
1730 Everything goes to an example anonymizing proxy, except SSL on port 443
1731 (which it doesn't handle):
1733 forward / anon-proxy.example.org:8080
1736 Everything goes to our example ISP's caching proxy, except for requests to
1739 forward / caching-proxy.example-isp.net:8000
1740 forward .example-isp.net .
1742 -------------------------------------------------------------------------------
1744 7.5.2. forward-socks4 and forward-socks4a
1748 Through which SOCKS proxy (and to which parent HTTP proxy) specific
1749 requests should be routed.
1753 target_pattern socks_proxy[:port] http_parent[:port]
1755 where target_pattern is a URL pattern that specifies to which requests
1756 (i.e. URLs) this forward rule shall apply. Use / to denote "all URLs".
1757 http_parent and socks_proxy are IP addresses in dotted decimal notation or
1758 valid DNS names (http_parent may be "." to denote "no HTTP forwarding"),
1759 and the optional port parameters are TCP ports, i.e. integer values from 1
1768 Don't use SOCKS proxies.
1772 Multiple lines are OK, they are checked in sequence, and the last match
1775 The difference between forward-socks4 and forward-socks4a is that in the
1776 SOCKS 4A protocol, the DNS resolution of the target hostname happens on the
1777 SOCKS server, while in SOCKS 4 it happens locally.
1779 If http_parent is ".", then requests are not forwarded to another HTTP
1780 proxy but are made (HTTP-wise) directly to the web servers, albeit through
1785 From the company example.com, direct connections are made to all "internal"
1786 domains, but everything outbound goes through their ISP's proxy by way of
1787 example.com's corporate SOCKS 4A gateway to the Internet.
1789 forward-socks4a / socks-gw.example.com:1080 www-cache.example-isp.net:8080
1790 forward .example.com .
1792 A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent
1795 forward-socks4 / socks-gw.example.com:1080 .
1797 -------------------------------------------------------------------------------
1799 7.5.3. Advanced Forwarding Examples
1801 If you have links to multiple ISPs that provide various special content only to
1802 their subscribers, you can configure multiple Privoxies which have connections
1803 to the respective ISPs to act as forwarders to each other, so that your users
1804 can see the internal content of all ISPs.
1806 Assume that host-a has a PPP connection to isp-a.net. And host-b has a PPP
1807 connection to isp-b.net. Both run Privoxy. Their forwarding configuration can
1813 forward .isp-b.net host-b:8118
1818 forward .isp-a.net host-a:8118
1820 Now, your users can set their browser's proxy to use either host-a or host-b
1821 and be able to browse the internal content of both isp-a and isp-b.
1823 If you intend to chain Privoxy and squid locally, then chain as browser ->
1824 squid -> privoxy is the recommended way.
1826 Assuming that Privoxy and squid run on the same box, your squid configuration
1827 could then look like this:
1829 # Define Privoxy as parent proxy (without ICP)
1830 cache_peer 127.0.0.1 parent 8118 7 no-query
1832 # Define ACL for protocol FTP
1835 # Do not forward FTP requests to Privoxy
1836 always_direct allow ftp
1838 # Forward all the rest to Privoxy
1839 never_direct allow all
1841 You would then need to change your browser's proxy settings to squid's address
1842 and port. Squid normally uses port 3128. If unsure consult http_port in
1845 You could just as well decide to only forward requests for Windows executables
1846 through a virus-scanning parent proxy, say, on antivir.example.com, port 8010:
1849 forward /.*\.(exe|com|dll|zip)$ antivir.example.com:8010
1851 -------------------------------------------------------------------------------
1853 7.6. Windows GUI Options
1855 Privoxy has a number of options specific to the Windows GUI interface:
1857 If "activity-animation" is set to 1, the Privoxy icon will animate when
1858 "Privoxy" is active. To turn off, set to 0.
1860 activity-animation 1
1863 If "log-messages" is set to 1, Privoxy will log messages to the console window:
1868 If "log-buffer-size" is set to 1, the size of the log buffer, i.e. the amount
1869 of memory used for the log messages displayed in the console window, will be
1870 limited to "log-max-lines" (see below).
1872 Warning: Setting this to 0 will result in the buffer to grow infinitely and eat
1878 log-max-lines is the maximum number of lines held in the log buffer. See above.
1883 If "log-highlight-messages" is set to 1, Privoxy will highlight portions of the
1884 log messages with a bold-faced font:
1886 log-highlight-messages 1
1889 The font used in the console window:
1891 log-font-name Comic Sans MS
1894 Font size used in the console window:
1899 "show-on-task-bar" controls whether or not Privoxy will appear as a button on
1900 the Task bar when minimized:
1905 If "close-button-minimizes" is set to 1, the Windows close button will minimize
1906 Privoxy instead of closing the program (close with the exit option on the File
1909 close-button-minimizes 1
1912 The "hide-console" option is specific to the MS-Win console version of Privoxy.
1913 If this option is used, Privoxy will disconnect from and hide the command
1919 -------------------------------------------------------------------------------
1923 The actions files are used to define what actions Privoxy takes for which URLs,
1924 and thus determine how ad images, cookies and various other aspects of HTTP
1925 content and transactions are handled, and on which sites (or even parts
1926 thereof). There are three such files included with Privoxy (as of version
1927 2.9.15), with differing purposes:
1929 * default.action - is the primary action file that sets the initial values
1930 for all actions. It is intended to provide a base level of functionality
1931 for Privoxy's array of features. So it is a set of broad rules that should
1932 work reasonably well for users everywhere. This is the file that the
1933 developers are keeping updated, and making available to users.
1935 * user.action - is intended to be for local site preferences and exceptions.
1936 As an example, if your ISP or your bank has specific requirements, and need
1937 special handling, this kind of thing should go here. This file will not be
1940 * standard.action - is used by the web based editor, to set various
1941 pre-defined sets of rules for the default actions section in
1942 default.action. These have increasing levels of aggressiveness and have no
1943 influence on your browsing unless you select them explicitly in the editor.
1944 It is not recommend to edit this file.
1946 The list of actions files to be used are defined in the main configuration
1947 file, and are processed in the order they are defined. The content of these can
1948 all be viewed and edited from http://config.privoxy.org/show-status.
1950 An actions file typically has multiple sections. If you want to use "aliases"
1951 in an actions file, you have to place the (optional) alias section at the top
1952 of that file. Then comes the default set of rules which will apply universally
1953 to all sites and pages (be very careful with using such a universal set in
1954 user.action or any other actions file after default.action, because it will
1955 override the result from consulting any previous file). And then below that,
1956 exceptions to the defined universal policies. You can regard user.action as an
1957 appendix to default.action, with the advantage that is a separate file, which
1958 makes preserving your personal settings across Privoxy upgrades easier.
1960 Actions can be used to block anything you want, including ads, banners, or just
1961 some obnoxious URL that you would rather not see. Cookies can be accepted or
1962 rejected, or accepted only during the current browser session (i.e. not written
1963 to disk), content can be modified, JavaScripts tamed, user-tracking fooled, and
1964 much more. See below for a complete list of actions.
1966 -------------------------------------------------------------------------------
1968 8.1. Finding the Right Mix
1970 Note that some actions, like cookie suppression or script disabling, may render
1971 some sites unusable that rely on these techniques to work properly. Finding the
1972 right mix of actions is not always easy and certainly a matter of personal
1973 taste. In general, it can be said that the more "aggressive" your default
1974 settings (in the top section of the actions file) are, the more exceptions for
1975 "trusted" sites you will have to make later. If, for example, you want to kill
1976 popup windows per default, you'll have to make exceptions from that rule for
1977 sites that you regularly use and that require popups for actually useful
1978 content, like maybe your bank, favorite shop, or newspaper.
1980 We have tried to provide you with reasonable rules to start from in the
1981 distribution actions files. But there is no general rule of thumb on these
1982 things. There just are too many variables, and sites are constantly changing.
1983 Sooner or later you will want to change the rules (and read this chapter again
1986 -------------------------------------------------------------------------------
1990 The easiest way to edit the actions files is with a browser by using our
1991 browser-based editor, which can be reached from http://config.privoxy.org/
1992 show-status. The editor allows both fine-grained control over every single
1993 feature on a per-URL basis, and easy choosing from wholesale sets of defaults
1994 like "Cautious", "Medium" or "Advanced".
1996 If you prefer plain text editing to GUIs, you can of course also directly edit
1997 the the actions files. Look at default.action which is richly commented.
1999 -------------------------------------------------------------------------------
2001 8.3. How Actions are Applied to URLs
2003 Actions files are divided into sections. There are special sections, like the "
2004 alias" sections which will be discussed later. For now let's concentrate on
2005 regular sections: They have a heading line (often split up to multiple lines
2006 for readability) which consist of a list of actions, separated by whitespace
2007 and enclosed in curly braces. Below that, there is a list of URL patterns, each
2010 To determine which actions apply to a request, the URL of the request is
2011 compared to all patterns in each action file file. Every time it matches, the
2012 list of applicable actions for the URL is incrementally updated, using the
2013 heading of the section in which the pattern is located. If multiple matches for
2014 the same URL set the same action differently, the last match wins. If not, the
2015 effects are aggregated. E.g. a URL might match a regular section with a heading
2016 line of { +handle-as-image }, then later another one with just { +block },
2017 resulting in both actions to apply.
2019 You can trace this process for any given URL by visiting http://
2020 config.privoxy.org/show-url-info.
2022 More detail on this is provided in the Appendix, Anatomy of an Action.
2024 -------------------------------------------------------------------------------
2028 Generally, a pattern has the form <domain>/<path>, where both the <domain> and
2029 <path> are optional. (This is why the pattern / matches all URLs).
2033 is a domain-only pattern and will match any request to www.example.com,
2034 regardless of which document on that server is requested.
2038 means exactly the same. For domain-only patterns, the trailing / may be
2041 www.example.com/index.html
2043 matches only the single document /index.html on www.example.com.
2047 matches the document /index.html, regardless of the domain, i.e. on any web
2052 matches nothing, since it would be interpreted as a domain name and there
2053 is no top-level domain called .html.
2055 -------------------------------------------------------------------------------
2057 8.4.1. The Domain Pattern
2059 The matching of the domain part offers some flexible options: if the domain
2060 starts or ends with a dot, it becomes unanchored at that end. For example:
2064 matches any domain that ENDS in .example.com
2068 matches any domain that STARTS with www.
2072 matches any domain that CONTAINS .example. (Correctly speaking: It matches
2073 any FQDN that contains example as a domain.)
2075 Additionally, there are wild-cards that you can use in the domain names
2076 themselves. They work pretty similar to shell wild-cards: "*" stands for zero
2077 or more arbitrary characters, "?" stands for any single character, you can
2078 define character classes in square brackets and all of that can be freely
2083 matches "adserver.example.com", "ads.example.com", etc but not
2088 matches all of the above, and then some.
2092 matches www.ipix.com, pictures.epix.com, a.b.c.d.e.upix.com etc.
2094 www[1-9a-ez].example.c*
2096 matches www1.example.com, www4.example.cc, wwwd.example.cy,
2097 wwwz.example.com etc., but not wwww.example.com.
2099 -------------------------------------------------------------------------------
2101 8.4.2. The Path Pattern
2103 Privoxy uses Perl compatible regular expressions (through the PCRE library) for
2106 There is an Appendix with a brief quick-start into regular expressions, and
2107 full (very technical) documentation on PCRE regex syntax is available on-line
2108 at http://www.pcre.org/man.txt. You might also find the Perl man page on
2109 regular expressions (man perlre) useful, which is available on-line at http://
2110 www.perldoc.com/perl5.6/pod/perlre.html.
2112 Note that the path pattern is automatically left-anchored at the "/", i.e. it
2113 matches as if it would start with a "^" (regular expression speak for the
2114 beginning of a line).
2116 Please also note that matching in the path is CASE INSENSITIVE by default, but
2117 you can switch to case sensitive at any point in the pattern by using the "(?
2118 -i)" switch: www.example.com/(?-i)PaTtErN.* will match only documents whose
2119 path starts with PaTtErN in exactly this capitalization.
2121 -------------------------------------------------------------------------------
2125 All actions are disabled by default, until they are explicitly enabled
2126 somewhere in an actions file. Actions are turned on if preceded with a "+", and
2127 turned off if preceded with a "-". So a +action means "do that action", e.g.
2128 +block means "please block URLs that match the following patterns", and -block
2129 means "don't block URLs that match the following patterns, even if +block
2130 previously applied."
2132 Again, actions are invoked by placing them on a line, enclosed in curly braces
2133 and separated by whitespace, like in {+some-action -some-other-action
2134 {some-parameter}}, followed by a list of URL patterns, one per line, to which
2135 they apply. Together, the actions line and the following pattern lines make up
2136 a section of the actions file.
2138 There are three classes of actions:
2140 * Boolean, i.e the action can only be "enabled" or "disabled". Syntax:
2142 +name # enable action name
2143 -name # disable action name
2147 * Parameterized, where some value is required in order to enable this type of
2150 +name{param} # enable action and set parameter to param,
2151 # overwriting parameter from previous match if necessary
2152 -name # disable action. The parameter can be omitted
2154 Note that if the URL matches multiple positive forms of a parameterized
2155 action, the last match wins, i.e. the params from earlier matches are
2158 Example: +hide-user-agent{ Mozilla 1.0 }
2160 * Multi-value. These look exactly like parameterized actions, but they behave
2161 differently: If the action applies multiple times to the same URL, but with
2162 different parameters, all the parameters from all matches are remembered.
2163 This is used for actions that can be executed for the same request
2164 repeatedly, like adding multiple headers, or filtering through multiple
2167 +name{param} # enable action and add param to the list of parameters
2168 -name{param} # remove the parameter param from the list of parameters
2169 # If it was the last one left, disable the action.
2170 -name # disable this action completely and remove all parameters from the list
2172 Examples: +add-header{X-Fun-Header: Some text} and +filter{html-annoyances}
2174 If nothing is specified in any actions file, no "actions" are taken. So in this
2175 case Privoxy would just be a normal, non-blocking, non-anonymizing proxy. You
2176 must specifically enable the privacy and blocking features you need (although
2177 the provided default actions files will give a good starting point).
2179 Later defined actions always over-ride earlier ones. So exceptions to any rules
2180 you make, should come in the latter part of the file (or in a file that is
2181 processed later when using multiple actions files). For multi-valued actions,
2182 the actions are applied in the order they are specified. Actions files are
2183 processed in the order they are defined in config (the default installation has
2184 three actions files). It also quite possible for any given URL pattern to match
2185 more than one pattern and thus more than one set of actions!
2187 The list of valid Privoxy actions are:
2189 -------------------------------------------------------------------------------
2195 Confuse log analysis, custom applications
2199 Sends a user defined HTTP header to the web server.
2207 Any string value is possible. Validity of the defined HTTP headers is not
2208 checked. It is recommended that you use the "X-" prefix for custom headers.
2212 This action may be specified multiple times, in order to define multiple
2213 headers. This is rarely needed for the typical user. If you don't know what
2214 "HTTP headers" are, you definitely don't need to worry about this one.
2218 +add-header{X-User-Tracking: sucks}
2220 -------------------------------------------------------------------------------
2226 Block ads or other obnoxious content
2230 Requests for URLs to which this action applies are blocked, i.e. the
2231 requests are not forwarded to the remote server, but answered locally with
2232 a substitute page or image, as determined by the handle-as-image and
2233 set-image-blocker actions.
2245 Privoxy sends a special "BLOCKED" page for requests to blocked pages. This
2246 page contains links to find out why the request was blocked, and a
2247 click-through to the blocked content (the latter only if compiled with the
2248 force feature enabled). The "BLOCKED" page adapts to the available screen
2249 space -- it displays full-blown if space allows, or miniaturized and
2250 text-only if loaded into a small frame or window. If you are using Privoxy
2251 right now, you can take a look at the "BLOCKED" page.
2253 A very important exception occurs if both block and handle-as-image, apply
2254 to the same request: it will then be replaced by an image. If
2255 set-image-blocker (see below) also applies, the type of image will be
2256 determined by its parameter, if not, the standard checkerboard pattern is
2259 It is important to understand this process, in order to understand how
2260 Privoxy deals with ads and other unwanted content.
2262 The filter action can perform a very similar task, by "blocking" banner
2263 images and other content through rewriting the relevant URLs in the
2264 document's HTML source, so they don't get requested in the first place.
2265 Note that this is a totally different technique, and it's easy to confuse
2268 Example usage (section):
2270 {+block} # Block and replace with "blocked" page
2271 .nasty-stuff.example.com
2273 {+block +handle-as-image} # Block and replace with image
2277 -------------------------------------------------------------------------------
2279 8.5.3. crunch-incoming-cookies
2283 Prevent the web server from setting any cookies on your system
2287 Deletes any "Set-Cookie:" HTTP headers from server replies.
2299 This action is only concerned with incoming cookies. For outgoing cookies,
2300 use crunch-outgoing-cookies. Use both to disable cookies completely.
2302 It makes no sense at all to use this action in conjunction with the
2303 session-cookies-only action, since it would prevent the session cookies
2308 +crunch-incoming-cookies
2310 -------------------------------------------------------------------------------
2312 8.5.4. crunch-outgoing-cookies
2316 Prevent the web server from reading any cookies from your system
2320 Deletes any "Cookie:" HTTP headers from client requests.
2332 This action is only concerned with outgoing cookies. For incoming cookies,
2333 use crunch-incoming-cookies. Use both to disable cookies completely.
2335 It makes no sense at all to use this action in conjunction with the
2336 session-cookies-only action, since it would prevent the session cookies
2341 +crunch-outgoing-cookies
2343 -------------------------------------------------------------------------------
2345 8.5.5. deanimate-gifs
2349 Stop those annoying, distracting animated GIF images.
2353 De-animate GIF animations, i.e. reduce them to their first or last image.
2365 This will also shrink the images considerably (in bytes, not pixels!). If
2366 the option "first" is given, the first frame of the animation is used as
2367 the replacement. If "last" is given, the last frame of the animation is
2368 used instead, which probably makes more sense for most banner animations,
2369 but also has the risk of not showing the entire last frame (if it is only a
2370 delta to an earlier frame).
2372 You can safely use this action with patterns that will also match non-GIF
2373 objects, because no attempt will be made at anything that doesn't look like
2378 +deanimate-gifs{last}
2380 -------------------------------------------------------------------------------
2382 8.5.6. downgrade-http-version
2386 Work around (very rare) problems with HTTP/1.1
2390 Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0.
2402 This is a left-over from the time when Privoxy didn't support important
2403 HTTP/1.1 features well. It is left here for the unlikely case that you
2404 experience HTTP/1.1 related problems with some server out there. Not all
2405 (optional) HTTP/1.1 features are supported yet, so there is a chance you
2406 might need this action.
2408 Example usage (section):
2410 {+downgrade-http-version}
2411 problem-host.example.com
2413 -------------------------------------------------------------------------------
2415 8.5.7. fast-redirects
2419 Fool some click-tracking scripts and speed up indirect links
2423 Cut off all but the last valid URL from requests.
2435 Many sites, like yahoo.com, don't just link to other sites. Instead, they
2436 will link to some script on their own servers, giving the destination as a
2437 parameter, which will then redirect you to the final target. URLs resulting
2438 from this scheme typically look like: http://some.place/click-tracker.cgi?
2439 target=http://some.where.else.
2441 Sometimes, there are even multiple consecutive redirects encoded in the
2442 URL. These redirections via scripts make your web browsing more traceable,
2443 since the server from which you follow such a link can see where you go to.
2444 Apart from that, valuable bandwidth and time is wasted, while your browser
2445 ask the server for one redirect after the other. Plus, it feeds the
2448 This feature is currently not very smart and is scheduled for improvement.
2449 It is likely to break some sites. You should expect to need possibly many
2450 exceptions to this action, if it is enabled by default in default.action.
2451 Some sites just don't work without it.
2457 -------------------------------------------------------------------------------
2463 Get rid of HTML and JavaScript annoyances, banner advertisements (by size),
2464 do fun text replacements, etc.
2468 Text documents, including HTML and JavaScript, to which this action
2469 applies, are filtered on-the-fly through the specified regular expression
2470 based substitutions.
2478 The name of a filter, as defined in the filter file (typically
2479 default.filter, set by the filterfile option in the config file). Filtering
2480 can be completely disabled without the use of parameters.
2484 For your convenience, there are a number of pre-defined filters available
2485 in the distribution filter file that you can use. See the examples below
2488 This is potentially a very powerful feature! But "rolling your own" filters
2489 requires a knowledge of regular expressions and HTML.
2491 Filtering requires buffering the page content, which may appear to slow
2492 down page rendering since nothing is displayed until all content has passed
2493 the filters. (It does not really take longer, but seems that way since the
2494 page is not incrementally displayed.) This effect will be more noticeable
2495 on slower connections.
2497 The amount of data that can be filtered is limited to the buffer-limit
2498 option in the main config file. The default is 4096 KB (4 Megs). Once this
2499 limit is exceeded, the buffered data, and all pending data, is passed
2500 through unfiltered. Inappropriate MIME types are not filtered.
2502 At this time, Privoxy cannot (yet!) uncompress compressed documents. If you
2503 want filtering to work on all documents, even those that would normally be
2504 sent compressed, use the prevent-compression action in conjunction with
2507 Filtering can achieve some of the same effects as the block action, i.e. it
2508 can be used to block ads and banners. But the mechanism works quite
2509 differently. One effective use, is to block ad banners based on their size
2510 (see below), since many of these seem to be somewhat standardized.
2512 Feedback with suggestions for new or improved filters is particularly
2515 Example usage (with filters from the distribution default.filter file):
2517 +filter{html-annoyances} # Get rid of particularly annoying HTML abuse.
2519 +filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse
2521 +filter{banners-by-size} # Kill banners based on their size for this page (very efficient!)
2523 +filter{banners-by-link} # Kill banners based on the link they are contained in (experimental)
2525 +filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective
2527 +filter{content-cookies} # Kill cookies that come sneaking in the HTML or JS content
2529 +filter{popups} # Kill all popups in JS and HTML
2531 +filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking)
2533 +filter{fun} # Text replacements for subversive browsing fun!
2535 +filter{frameset-borders} # Give frames a border and make them resizeable
2537 +filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups)
2539 +filter{nimda} # Remove Nimda (virus) code.
2541 +filter{shockwave-flash} # Kill embedded Shockwave Flash objects
2543 +filter{crude-parental} # Kill all web pages that contain the words "sex" or "warez"
2545 +filter{js-events} # Kill all JS event bindings (Radically destructive! Only for extra nasty sites)
2547 -------------------------------------------------------------------------------
2549 8.5.9. handle-as-image
2553 Mark URLs as belonging to images (so they'll be replaced by images if they
2558 This action alone doesn't do anything noticeable. It just marks URLs as
2559 images. If the block action also applies, the presence or absence of this
2560 mark decides whether an HTML "blocked" page, or a replacement image (as
2561 determined by the set-image-blocker action) will be sent to the client as a
2562 substitute for the blocked content.
2574 The below generic example section is actually part of default.action. It
2575 marks all URLs with well-known image file name extensions as images and
2576 should be left intact.
2578 Users will probably only want to use the handle-as-image action in
2579 conjunction with block, to block sources of banners, whose URLs don't
2580 reflect the file type, like in the second example section.
2582 Note that you cannot treat HTML pages as images in most cases. For
2583 instance, (in-line) ad frames require an HTML page to be sent, or they
2584 won't display properly. Forcing handle-as-image in this situation will not
2585 replace the ad frame with an image, but lead to error messages.
2587 Example usage (sections):
2589 # Generic image extensions:
2592 /.*\.(gif|jpg|jpeg|png|bmp|ico)$
2594 # These don't look like images, but they're banners and should be
2595 # blocked as images:
2597 {+block +handle-as-image}
2598 some.nasty-banner-server.com/junk.cgi?output=trash
2600 # Banner source! Who cares if they also have non-image content?
2603 -------------------------------------------------------------------------------
2605 8.5.10. hide-forwarded-for-headers
2609 Improve privacy by hiding the true source of the request
2613 Deletes any existing "X-Forwarded-for:" HTTP header from client requests,
2614 and prevents adding a new one.
2626 It is fairly safe to leave this on.
2628 This action is scheduled for improvement: It should be able to generate
2629 forged "X-Forwarded-for:" headers using random IP addresses from a
2630 specified network, to make successive requests from the same client look
2631 like requests from a pool of different users sharing the same proxy.
2635 +hide-forwarded-for-headers
2637 -------------------------------------------------------------------------------
2639 8.5.11. hide-from-header
2643 Keep your (old and ill) browser from telling web servers your email address
2647 Deletes any existing "From:" HTTP header, or replaces it with the specified
2656 Keyword: "block", or any user defined value.
2660 The keyword "block" will completely remove the header (not to be confused
2661 with the block action).
2663 Alternately, you can specify any value you prefer to be sent to the web
2664 server. If you do, it is a matter of fairness not to use any address that
2665 is actually used by a real person.
2667 This action is rarely needed, as modern web browsers don't send "From:"
2672 +hide-from-header{block}
2676 +hide-from-header{spam-me-senseless@sittingduck.example.com}
2678 -------------------------------------------------------------------------------
2680 8.5.12. hide-referrer
2684 Conceal which link you followed to get to a particular site
2688 Deletes the "Referer:" (sic) HTTP header from the client request, or
2689 replaces it with a forged one.
2697 + "block" to delete the header completely.
2699 + "forge" to pretend to be coming from the homepage of the server we are
2702 + Any other string to set a user defined referrer.
2706 "forge" is the preferred option here, since some servers will not send
2707 images back otherwise, in an attempt to prevent their valuable content from
2708 being embedded elsewhere (and hence, without being surrounded by their
2711 hide-referer is an alternate spelling of hide-referrer and the two can be
2712 can be freely substituted with each other. ("referrer" is the correct
2713 English spelling, however the HTTP specification has a bug - it requires it
2714 to be spelled as "referer".)
2718 +hide-referrer{forge}
2722 +hide-referrer{http://www.yahoo.com/}
2724 -------------------------------------------------------------------------------
2726 8.5.13. hide-user-agent
2730 Conceal your type of browser and client operating system
2734 Replaces the value of the "User-Agent:" HTTP header in client requests with
2735 the specified value.
2743 Any user-defined string.
2747 +-----------------------------------------------------------------+
2749 |-----------------------------------------------------------------|
2750 |This breaks many web sites that depend on looking at this header |
2751 |in order to customize their content for different browsers |
2752 |(which, by the way, is NOT a smart way to do that!). |
2753 +-----------------------------------------------------------------+
2755 Using this action in multi-user setups or wherever different types of
2756 browsers will access the same Privoxy is not recommended. In single-user,
2757 single-browser setups, you might use it to delete your OS version
2758 information from the headers, because it is an invitation to exploit known
2759 bugs for your OS. It is also occasionally useful to forge this in order to
2760 access sites that won't let you in otherwise (though there may be a good
2761 reason in some cases). Example of this: some MSN sites will not let Mozilla
2762 enter, yet forging to a Netscape 6.1 user-agent works just fine. (Must be
2763 just a silly MS goof, I'm sure :-).
2765 This action is scheduled for improvement.
2769 +hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}
2771 -------------------------------------------------------------------------------
2777 Eliminate those annoying pop-up windows
2781 While loading the document, replace JavaScript code that opens pop-up
2782 windows with (syntactically neutral) dummy code on the fly.
2794 This action is easily confused with the built-in, hardwired filter action,
2795 but there are important differences: For kill-popups, the document need not
2796 be buffered, so it can be incrementally rendered while downloading. But
2797 kill-popups doesn't catch as many pop-ups as filter{popups} does.
2799 Think of it as a fast and efficient replacement for a filter that you can
2800 use if you don't want any filtering at all. Note that it doesn't make sense
2801 to combine it with any filter action, since as soon as one filter applies,
2802 the whole document needs to be buffered anyway, which destroys the
2803 advantage of the kill-popups action over its filter equivalent.
2805 Killing all pop-ups is a dangerous business. Many shops and banks rely on
2806 pop-ups to display forms, shopping carts etc, and killing only the unwanted
2807 pop-ups would require artificial intelligence in Privoxy. If the only kind
2808 of pop-ups that you want to kill are exit consoles (those really nasty
2809 windows that appear when you close an other one), you might want to use
2810 filter{js-annoyances} instead.
2816 -------------------------------------------------------------------------------
2818 8.5.15. limit-connect
2822 Prevent abuse of Privoxy as a TCP proxy relay
2826 Specifies to which ports HTTP CONNECT requests are allowable.
2834 A comma-separated list of ports or port ranges (the latter using dashes,
2835 with the minimum defaulting to 0 and the maximum to 65K).
2839 By default, i.e. if no limit-connect action applies, Privoxy only allows
2840 HTTP CONNECT requests to port 443 (the standard, secure HTTPS port). Use
2841 limit-connect if more fine-grained control is desired for some or all
2844 The CONNECT methods exists in HTTP to allow access to secure websites
2845 ("https://" URLs) through proxies. It works very simply: the proxy connects
2846 to the server on the specified port, and then short-circuits its
2847 connections to the client and to the remote server. This can be a big
2848 security hole, since CONNECT-enabled proxies can be abused as TCP relays
2851 If you don't know what any of this means, there probably is no reason to
2852 change this one, since the default is already very restrictive.
2856 +limit-connect{443} # This is the default and need not be specified.
2857 +limit-connect{80,443} # Ports 80 and 443 are OK.
2858 +limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
2859 +limit-connect{-} # All ports are OK (gaping security hole!)
2861 -------------------------------------------------------------------------------
2863 8.5.16. prevent-compression
2867 Ensure that servers send the content uncompressed, so it can be passed
2872 Adds a header to the request that asks for uncompressed transfer.
2884 More and more websites send their content compressed by default, which is
2885 generally a good idea and saves bandwidth. But for the filter,
2886 deanimate-gifs and kill-popups actions to work, Privoxy needs access to the
2887 uncompressed data. Unfortunately, Privoxy can't yet(!) uncompress, filter,
2888 and re-compress the content on the fly. So if you want to ensure that all
2889 websites, including those that normally compress, can be filtered, you need
2892 This will slow down transfers from those websites, though. If you use any
2893 of the above-mentioned actions, you will typically want to use
2894 prevent-compression in conjunction with them.
2896 Note that some (rare) ill-configured sites don't handle requests for
2897 uncompressed documents correctly (they send an empty document body). If you
2898 use prevent-compression per default, you'll have to add exceptions for
2899 those sites. See the example for how to do that.
2901 Example usage (sections):
2905 {+prevent-compression}
2908 # Make exceptions for ill sites:
2910 {-prevent-compression}
2912 www.pclinuxonline.com
2914 -------------------------------------------------------------------------------
2916 8.5.17. send-vanilla-wafer
2920 Feed log analysis scripts with useless data.
2924 Sends a cookie with each request stating that you do not accept any
2925 copyright on cookies sent to you, and asking the site operator not to track
2938 The vanilla wafer is a (relatively) unique header and could conceivably be
2941 This action is rarely used and not enabled in the default configuration.
2947 -------------------------------------------------------------------------------
2953 Send custom cookies or feed log analysis scripts with even more useless
2958 Sends a custom, user-defined cookie with each request.
2966 A string of the form "name=value".
2970 Being multi-valued, multiple instances of this action can apply to the same
2971 request, resulting in multiple cookies being sent.
2973 This action is rarely used and not enabled in the default configuration.
2975 Example usage (section):
2977 {+send-wafer{UsingPrivoxy=true}}
2978 my-internal-testing-server.void
2980 -------------------------------------------------------------------------------
2982 8.5.19. session-cookies-only
2986 Allow only temporary "session" cookies (for the current browser session
2991 Deletes the "expires" field from "Set-Cookie:" server headers. Most
2992 browsers will not store such cookies permanently and forget them in between
3005 This is less strict than crunch-incoming-cookies / crunch-outgoing-cookies
3006 and allows you to browse websites that insist or rely on setting cookies,
3007 without compromising your privacy too badly.
3009 Most browsers will not permanently store cookies that have been processed
3010 by session-cookies-only and will forget about them between sessions. This
3011 makes profiling cookies useless, but won't break sites which require
3012 cookies so that you can log in for transactions. This is generally turned
3013 on for all sites, and is the recommended setting.
3015 It makes no sense at all to use session-cookies-only together with
3016 crunch-incoming-cookies or crunch-outgoing-cookies. If you do, cookies will
3019 Note that it is up to the browser how it handles such cookies without an
3020 "expires" field. If you use an exotic browser, you might want to try it out
3025 +session-cookies-only
3027 -------------------------------------------------------------------------------
3029 8.5.20. set-image-blocker
3033 Choose the replacement for blocked images
3037 This action alone doesn't do anything noticeable. If both block and
3038 handle-as-image also apply, i.e. if the request is to be blocked as an
3039 image, then the parameter of this action decides what will be sent as a
3048 + "pattern" to send a built-in checkerboard pattern image. The image is
3049 visually decent, scales very well, and makes it obvious where banners
3052 + "blank" to send a built-in transparent image. This makes banners
3053 disappear completely, but makes it hard to detect where Privoxy has
3054 blocked images on a given page and complicates troubleshooting if
3055 Privoxy has blocked innocent images, like navigation icons.
3057 + "target-url" to send a redirect to target-url. You can redirect to any
3058 image anywhere, even in your local filesystem (via "file:///" URL).
3060 A good application of redirects is to use special Privoxy-built-in
3061 URLs, which send the built-in images, as target-url. This has the same
3062 visual effect as specifying "blank" or "pattern" in the first place,
3063 but enables your browser to cache the replacement image, instead of
3064 requesting it over and over again.
3068 The URLs for the built-in images are "http://config.privoxy.org/
3069 send-banner?type=type", where type is either "blank" or "pattern".
3071 There is a third (advanced) type, called "auto". It is NOT to be used in
3072 set-image-blocker, but meant for use from filters. Auto will select the
3073 type of image that would have applied to the referring page, had it been an
3080 +set-image-blocker{pattern}
3082 Redirect to the BSD devil:
3084 +set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}
3086 Redirect to the built-in pattern for better caching:
3088 +set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}
3090 -------------------------------------------------------------------------------
3094 Note that many of these actions have the potential to cause a page to
3095 misbehave, possibly even not to display at all. There are many ways a site
3096 designer may choose to design his site, and what HTTP header content, and other
3097 criteria, he may depend on. There is no way to have hard and fast rules for all
3098 sites. See the Appendix for a brief example on troubleshooting actions.
3100 -------------------------------------------------------------------------------
3104 Custom "actions", known to Privoxy as "aliases", can be defined by combining
3105 other actions. These can in turn be invoked just like the built-in actions.
3106 Currently, an alias name can contain any character except space, tab, "=", "{"
3107 and "}", but we strongly recommend that you only use "a" to "z", "0" to "9",
3108 "+", and "-". Alias names are not case sensitive, and are not required to start
3109 with a "+" or "-" sign, since they are merely textually expanded.
3111 Aliases can be used throughout the actions file, but they must be defined in a
3112 special section at the top of the file! And there can only be one such section
3113 per actions file. Each actions file may have its own alias section, and the
3114 aliases defined in it are only visible within that file.
3116 There are two main reasons to use aliases: One is to save typing for frequently
3117 used combinations of actions, the other one is a gain in flexibility: If you
3118 decide once how you want to handle shops by defining an alias called "shop",
3119 you can later change your policy on shops in one place, and your changes will
3120 take effect everywhere in the actions file where the "shop" alias is used.
3121 Calling aliases by their purpose also makes your actions files more readable.
3123 Currently, there is one big drawback to using aliases, though: Privoxy's
3124 built-in web-based action file editor honors aliases when reading the actions
3125 files, but it expands them before writing. So the effects of your aliases are
3126 of course preserved, but the aliases themselves are lost when you edit sections
3127 that use aliases with it. This is likely to change in future versions of
3130 Now let's define some aliases...
3132 # Useful custom aliases we can use later.
3134 # Note the (required!) section header line and that this section
3135 # must be at the top of the actions file!
3139 # These aliases just save typing later:
3140 # (Note that some already use other aliases!)
3142 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
3143 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
3144 block-as-image = +block +handle-as-image
3145 mercy-for-cookies = -crunch-all-cookies -session-cookies-only
3147 # These aliases define combinations of actions
3148 # that are useful for certain types of sites:
3150 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
3151 shop = -crunch-all-cookies -filter{popups} -kill-popups
3153 # Short names for other aliases, for really lazy people ;-)
3155 c0 = +crunch-all-cookies
3156 c1 = -crunch-all-cookies
3158 ...and put them to use. These sections would appear in the lower part of an
3159 actions file and define exceptions to the default actions (as specified further
3160 up for the "/" pattern):
3162 # These sites are either very complex or very keen on
3163 # user data and require minimal interference to work:
3166 .office.microsoft.com
3167 .windowsupdate.microsoft.com
3171 # Allow cookies (for setting and retrieving your customer data)
3175 .worldpay.com # for quietpc.com
3178 # These shops require pop-ups:
3180 {shop -kill-popups -filter{popups}}
3184 Aliases like "shop" and "fragile" are often used for "problem" sites that
3185 require some actions to be disabled in order to function properly.
3187 -------------------------------------------------------------------------------
3189 8.7. Actions Files Tutorial
3191 The above chapters have shown which actions files there are and how they are
3192 organized, how actions are specified and applied to URLs, how patterns work,
3193 and how to define and use aliases. Now, let's look at an example default.action
3194 and user.action file and see how all these pieces come together:
3196 -------------------------------------------------------------------------------
3198 8.7.1. default.action
3200 Every config file should start with a short comment stating its purpose:
3202 # Sample default.action file <developers@privoxy.org>
3204 Then, since this is the default.action file, the first section is a special
3205 section for internal use that you needn't change or worry about:
3207 ##########################################################################
3208 # Settings -- Don't change! For internal Privoxy use ONLY.
3209 ##########################################################################
3212 for-privoxy-version=3.0
3214 After that comes the (optional) alias section. We'll use the example section
3215 from the above chapter on aliases, that also explains why and how aliases are
3218 ##########################################################################
3220 ##########################################################################
3223 # These aliases just save typing later:
3224 # (Note that some already use other aliases!)
3226 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
3227 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
3228 block-as-image = +block +handle-as-image
3229 mercy-for-cookies = -crunch-all-cookies -session-cookies-only
3231 # These aliases define combinations of actions
3232 # that are useful for certain types of sites:
3234 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
3235 shop = mercy-for-cookies -filter{popups} -kill-popups
3237 Now come the regular sections, i.e. sets of actions, accompanied by URL
3238 patterns to which they apply. Remember all actions are disabled when matching
3239 starts, so we have to explicitly enable the ones we want.
3241 The first regular section is probably the most important. It has only one
3242 pattern, "/", but this pattern matches all URLs. Therefore, the set of actions
3243 used in this "default" section will be applied to all requests as a start. It
3244 can be partly or wholly overridden by later matches further down this file, or
3245 in user.action, but it will still be largely responsible for your overall
3246 browsing experience.
3248 Again, at the start of matching, all actions are disabled, so there is no real
3249 need to disable any actions here, but we will do that nonetheless, to have a
3250 complete listing for your reference. (Remember: a "+" preceding the action name
3251 enables the action, a "-" disables!). Also note how this long line has been
3252 made more readable by splitting it into multiple lines with line continuation.
3254 ##########################################################################
3255 # "Defaults" section:
3256 ##########################################################################
3260 -crunch-incoming-cookies \
3261 -crunch-outgoing-cookies \
3263 -downgrade-http-version \
3265 +filter{html-annoyances} \
3266 +filter{js-annoyances} \
3267 -filter{content-cookies} \
3270 -filter{refresh-tags} \
3273 +filter{banners-by-size} \
3274 -filter{banners-by-link} \
3275 -filter{img-reorder} \
3276 -filter{shockwave-flash} \
3277 -filter{crude-parental} \
3278 -filter{js-events} \
3280 +hide-forwarded-for-headers \
3281 +hide-from-header{block} \
3282 +hide-referrer{forge} \
3286 +prevent-compression \
3287 -send-vanilla-wafer \
3289 +session-cookies-only \
3290 +set-image-blocker{pattern} \
3292 / # forward slash will match *all* potential URL patterns.
3294 The default behavior is now set. Note that some actions, like not hiding the
3295 user agent, are part of a "general policy" that applies universally and won't
3296 get any exceptions defined later. Other choices, like not blocking (which is
3297 understandably the default!) need exceptions, i.e. we need to specify
3298 explicitly what we want to block in later sections. We will also want to make
3299 exceptions from our general pop-up-killing, and use our defined aliases for
3302 The first of our specialized sections is concerned with "fragile" sites, i.e.
3303 sites that require minimum interference, because they are either very complex
3304 or very keen on tracking you (and have mechanisms in place that make them
3305 unusable for people who avoid being tracked). We will simply use our
3306 pre-defined fragile alias instead of stating the list of actions explicitly:
3308 ##########################################################################
3309 # Exceptions for sites that'll break under the default action set:
3310 ##########################################################################
3312 # "Fragile" Use a minimum set of actions for these sites (see alias above):
3315 .office.microsoft.com # surprise, surprise!
3316 .windowsupdate.microsoft.com
3318 Shopping sites are not as fragile, but they typically require cookies to log
3319 in, and pop-up windows for shopping carts or item details. Again, we'll use a
3326 .worldpay.com # for quietpc.com
3330 Then, there are sites which rely on pop-up windows (yuck!) to work. Since we
3331 made pop-up-killing our default above, we need to make exceptions now. Mozilla
3332 users, who can turn on smart handling of unwanted pop-ups in their browsers,
3333 can safely choose -filter{popups} (and -kill-popups) above and hence don't need
3334 this section. Anyway, disabling an already disabled action doesn't hurt, so
3335 we'll define our exceptions regardless of what was chosen in the defaults
3338 # These sites require pop-ups too :(
3340 { -kill-popups -filter{popups} }
3343 .deutsche-bank-24.de
3345 The fast-redirects action, which we enabled per default above, breaks some
3346 sites. So disable it for popular sites where we know it misbehaves:
3352 .altavista.com/.*(like|url|link):http
3353 .altavista.com/trans.*urltext=http
3356 It is important that Privoxy knows which URLs belong to images, so that if they
3357 are to be blocked, a substitute image can be sent, rather than an HTML page.
3358 Contacting the remote site to find out is not an option, since it would destroy
3359 the loading time advantage of banner blocking, and it would feed the
3360 advertisers (in terms of money and information). We can mark any URL as an
3361 image with the handle-as-image action, and marking all URLs that end in a known
3362 image file extension is a good start:
3364 ##########################################################################
3366 ##########################################################################
3368 # Define which file types will be treated as images, in case they get
3369 # blocked further down this file:
3371 { +handle-as-image }
3372 /.*\.(gif|jpe?g|png|bmp|ico)$
3374 And then there are known banner sources. They often use scripts to generate the
3375 banners, so it won't be visible from the URL that the request is for an image.
3376 Hence we block them and mark them as images in one go, with the help of our
3377 block-as-image alias defined above. (We could of course just as well use +block
3378 +handle-as-image here.) Remember that the type of the replacement image is
3379 chosen by the set-image-blocker action. Since all URLs have matched the default
3380 section with its +set-image-blocker{pattern} action before, it still applies
3381 and needn't be repeated:
3383 # Known ad generators:
3388 .ad.*.doubleclick.net
3389 .a.yimg.com/(?:(?!/i/).)*$
3390 .a[0-9].yimg.com/(?:(?!/i/).)*$
3395 One of the most important jobs of Privoxy is to block banners. A huge bunch of
3396 them are already "blocked" by the filter{banners-by-size} action, which we
3397 enabled above, and which deletes the references to banner images from the pages
3398 while they are loaded, so the browser doesn't request them anymore, and hence
3399 they don't need to be blocked here. But this naturally doesn't catch all
3400 banners, and some people choose not to use filters, so we need a comprehensive
3401 list of patterns for banner URLs here, and apply the block action to them.
3403 First comes a bunch of generic patterns, which do most of the work, by matching
3404 typical domain and path name components of banners. Then comes a list of
3405 individual patterns for specific sites, which is omitted here to keep the
3408 ##########################################################################
3409 # Block these fine banners:
3410 ##########################################################################
3419 /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
3420 /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
3422 # Site-specific patterns (abbreviated):
3426 You wouldn't believe how many advertisers actually call their banner servers
3427 ads.company.com, or call the directory in which the banners are stored simply
3428 "banners". So the above generic patterns are surprisingly effective.
3430 But being very generic, they necessarily also catch URLs that we don't want to
3431 block. The pattern .*ads. e.g. catches "nasty-ads.nasty-corp.com" as intended,
3432 but also "downloads.sourcefroge.net" or "adsl.some-provider.net." So here come
3433 some well-known exceptions to the +block section above.
3435 Note that these are exceptions to exceptions from the default! Consider the URL
3436 "downloads.sourcefroge.net": Initially, all actions are deactivated, so it
3437 wouldn't get blocked. Then comes the defaults section, which matches the URL,
3438 but just deactivates the block action once again. Then it matches .*ads., an
3439 exception to the general non-blocking policy, and suddenly +block applies. And
3440 now, it'll match .*loads., where -block applies, so (unless it matches again
3441 further down) it ends up with no block action applying.
3443 ##########################################################################
3444 # Save some innocent victims of the above generic block patterns:
3445 ##########################################################################
3450 adv[io]*. # (for advogato.org and advice.*)
3451 adsl. # (has nothing to do with ads)
3452 ad[ud]*. # (adult.* and add.*)
3453 .edu # (universities don't host banners (yet!))
3454 .*loads. # (downloads, uploads etc)
3462 www.globalintersec.com/adv # (adv = advanced)
3463 www.ugu.com/sui/ugu/adv
3465 Filtering source code can have nasty side effects, so make an exception for our
3466 friends at sourceforge.net, and all paths with "cvs" in them. Note that -filter
3467 disables all filters in one fell swoop!
3469 # Don't filter code!
3475 The actual default.action is of course more comprehensive, but we hope this
3476 example made clear how it works.
3478 -------------------------------------------------------------------------------
3482 So far we are painting with a broad brush by setting general policies, which
3483 would be a reasonable starting point for many people. Now, you might want to be
3484 more specific and have customized rules that are more suitable to your personal
3485 habits and preferences. These would be for narrowly defined situations like
3486 your ISP or your bank, and should be placed in user.action, which is parsed
3487 after all other actions files and hence has the last word, over-riding any
3488 previously defined actions. user.action is also a safe place for your personal
3489 settings, since default.action is actively maintained by the Privoxy developers
3490 and you'll probably want to install updated versions from time to time.
3492 So let's look at a few examples of things that one might typically do in
3495 # My user.action file. <fred@foobar.com>
3497 As aliases are local to the actions file that they are defined in, you can't
3498 use the ones from default.action, unless you repeat them here:
3500 # (Re-)define aliases for this file:
3503 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
3504 mercy-for-cookies = -crunch-all-cookies -session-cookies-only
3505 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
3506 shop = mercy-for-cookies -filter{popups} -kill-popups
3507 allow-ads = -block -filter{banners-by-size} # (see below)
3509 Say you have accounts on some sites that you visit regularly, and you don't
3510 want to have to log in manually each time. So you'd like to allow persistent
3511 cookies for these sites. The mercy-for-cookies alias defined above does exactly
3512 that, i.e. it disables crunching of cookies in any direction, and processing of
3513 cookies to make them temporary.
3515 { mercy-for-cookies }
3522 Your bank needs popups and is allergic to some filter, but you don't know
3523 which, so you disable them all:
3525 { -filter -kill-popups }
3526 .your-home-banking-site.com
3528 While browsing the web with Privoxy you noticed some ads that sneaked through,
3529 but you were too lazy to report them through our fine and easy feedback system,
3530 so you have added them here:
3533 www.a-popular-site.com/some/unobvious/path
3534 another.popular.site.net/more/junk/here/
3536 Note that, assuming the banners in the above example have regular image
3537 extensions (most do), +handle-as-image need not be specified, since all URLs
3538 ending in these extensions will already have been tagged as images in the
3539 relevant section of default.action by now.
3541 Then you noticed that the default configuration breaks Forbes Magazine, but you
3542 were too lazy to find out which action is the culprit, and you were again too
3543 lazy to give feedback, so you just used the fragile alias on the site, and --
3549 You like the "fun" text replacements in default.filter, but it is disabled in
3550 the distributed actions file. (My colleagues on the team just don't have a
3551 sense of humour, that's why! ;-). So you'd like to turn it on in your private,
3552 update-safe config, once and for all:
3557 Note that the above is not really a good idea: There are exceptions to the
3558 filters in default.action for things that really shouldn't be filtered, like
3559 code on CVS->Web interfaces. Since user.action has the last word, these
3560 exceptions won't be valid for the "fun" filtering specified here.
3562 Finally, you might think about how your favourite free websites are funded, and
3563 find that they rely on displaying banner advertisements to survive. So you
3564 might want to specifically allow banners for those sites that you feel provide
3572 Note that allow-ads has been aliased to -block -filter{banners-by-size} above.
3574 -------------------------------------------------------------------------------
3578 All text substitutions that can be invoked through the filter action must first
3579 be defined in the filter file, which is typically called default.filter and
3580 which can be selected through the filterfile config option.
3582 Typical reasons for doing such substitutions are to eliminate common annoyances
3583 in HTML and JavaScript, such as pop-up windows, exit consoles, crippled windows
3584 without navigation tools, the infamous <BLINK> tag etc, to suppress images with
3585 certain width and height attributes (standard banner sizes or web-bugs), or
3586 just to have fun. The possibilities are endless.
3588 Filtering works on any text-based document type, including plain text, HTML,
3589 JavaScript, CSS etc. (all text/* MIME types). Substitutions are made at the
3590 source level, so if you want to "roll your own" filters, you should be familiar
3593 Just like the actions files, the filter file is organized in sections, which
3594 are called filters here. Each filter consists of a heading line, that starts
3595 with the keyword FILTER:, followed by the filter's name, and a short (one line)
3596 description of what it does. Below that line come the jobs, i.e. lines that
3597 define the actual text substitutions. By convention, the name of a filter
3598 should describe what the filter eliminates. The comment is used in the
3599 web-based user interface.
3601 Once a filter called name has been defined in the filter file, it can be
3602 invoked by using an action of the form +filter{name} in any actions file.
3604 A filter header line for a filter called "foo" could look like this:
3606 FILTER: foo Replace all "foo" with "bar"
3608 Below that line, and up to the next header line, come the jobs that define what
3609 text replacements the filter executes. They are specified in a syntax that
3610 imitates Perl's s/// operator. If you are familiar with Perl, you will find
3611 this to be quite intuitive, and may want to look at the PCRS man page for the
3612 subtle differences to Perl behaviour. Most notably, the non-standard option
3613 letter U is supported, which turns the default to ungreedy matching.
3615 If you are new to regular expressions, you might want to take a look at the
3616 Appendix on regular expressions, and see the Perl manual for the s///
3617 operator's syntax and Perl-style regular expressions in general. The below
3618 examples might also help to get you started.
3620 -------------------------------------------------------------------------------
3622 9.1. Filter File Tutorial
3624 Now, let's complete our "foo" filter. We have already defined the heading, but
3625 the jobs are still missing. Since all it does is to replace "foo" with "bar",
3626 there is only one (trivial) job needed:
3630 But wait! Didn't the comment say that all occurrences of "foo" should be
3631 replaced? Our current job will only take care of the first "foo" on each page.
3632 For global substitution, we'll need to add the g option:
3636 Our complete filter now looks like this:
3638 FILTER: foo Replace all "foo" with "bar"
3641 Let's look at some real filters for more interesting examples. Here you see a
3642 filter that protects against some common annoyances that arise from JavaScript
3643 abuse. Let's look at its jobs one after the other:
3645 FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse
3647 # Get rid of JavaScript referrer tracking. Test page: http://www.randomoddness.com/untitled.htm
3649 s|(<script.*)document\.referrer(.*</script>)|$1"Not Your Business!"$2|Usg
3651 Following the header line and a comment, you see the job. Note that it uses |
3652 as the delimiter instead of /, because the pattern contains a forward slash,
3653 which would otherwise have to be escaped by a backslash (\).
3655 Now, let's examine the pattern: it starts with the text <script.* enclosed in
3656 parentheses. Since the dot matches any character, and * means: "Match an
3657 arbitrary number of the element left of myself", this matches "<script",
3658 followed by any text, i.e. it matches the whole page, from the start of the
3661 That's more than we want, but the pattern continues: document\.referrer matches
3662 only the exact string "document.referrer". The dot needed to be escaped, i.e.
3663 preceded by a backslash, to take away its special meaning as a joker, and make
3664 it just a regular dot. So far, the meaning is: Match from the start of the
3665 first <script> tag in a the page, up to, and including, the text
3666 "document.referrer", if both are present in the page (and appear in that
3669 But there's still more pattern to go. The next element, again enclosed in
3670 parentheses, is .*</script>. You already know what .* means, so the whole
3671 pattern translates to: Match from the start of the first <script> tag in a page
3672 to the end of the last <script> tag, provided that the text "document.referrer"
3673 appears somewhere in between.
3675 This is still not the whole story, since we have ignored the options and the
3676 parentheses: The portions of the page matched by sub-patterns that are enclosed
3677 in parentheses, will be remembered and be available through the variables $1,
3678 $2, ... in the substitute. The U option switches to ungreedy matching, which
3679 means that the first .* in the pattern will only "eat up" all text in between "
3680 <script" and the first occurrence of "document.referrer", and that the second .
3681 * will only span the text up to the first "</script>" tag. Furthermore, the s
3682 option says that the match may span multiple lines in the page, and the g
3683 option again means that the substitution is global.
3685 So, to summarize, the pattern means: Match all scripts that contain the text
3686 "document.referrer". Remember the parts of the script from (and including) the
3687 start tag up to (and excluding) the string "document.referrer" as $1, and the
3688 part following that string, up to and including the closing tag, as $2.
3690 Now the pattern is deciphered, but wasn't this about substituting things? So
3691 lets look at the substitute: $1"Not Your Business!"$2 is easy to read: The text
3692 remembered as $1, followed by "Not Your Business!" (including the quotation
3693 marks!), followed by the text remembered as $2. This produces an exact copy of
3694 the original string, with the middle part (the "document.referrer") replaced by
3695 "Not Your Business!".
3697 The whole job now reads: Replace "document.referrer" by "Not Your Business!"
3698 wherever it appears inside a <script> tag. Note that this job won't break
3699 JavaScript syntax, since both the original and the replacement are
3700 syntactically valid string objects. The script just won't have access to the
3701 referrer information anymore.
3703 We'll show you two other jobs from the JavaScript taming department, but this
3704 time only point out the constructs of special interest:
3706 # The status bar is for displaying link targets, not pointless blahblah
3708 s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig
3710 \s stands for whitespace characters (space, tab, newline, carriage return, form
3711 feed), so that \s* means: "zero or more whitespace". The ? in .*? makes this
3712 matching of arbitrary text ungreedy. (Note that the U option is not set). The
3713 ['"] construct means: "a single or a double quote". Finally, \1 is a
3714 backreference to the first parenthesis just like $1 above, with the difference
3715 that in the pattern, a backslash indicates a backreference, whereas in the
3716 substitute, it's the dollar.
3718 So what does this job do? It replaces assignments of single- or double-quoted
3719 strings to the "window.status" object with a dummy assignment (using a variable
3720 name that is hopefully odd enough not to conflict with real variables in
3721 scripts). Thus, it catches many cases where e.g. pointless descriptions are
3722 displayed in the status bar instead of the link target when you move your mouse
3725 # Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html
3727 s/(<body [^>]*)onunload(.*>)/$1never$2/iU
3729 Including the OnUnload event binding in the HTML DOM was a CRIME. When I close
3730 a browser window, I want it to close and die. Basta. This job replaces the
3731 "onunload" attribute in "<body>" tags with the dummy word never. Note that the
3732 i option makes the pattern matching case-insensitive. Also note that ungreedy
3733 matching alone doesn't always guarantee a minimal match: In the first
3734 parenthesis, we had to use [^>]* instead of .* to prevent the match from
3735 exceeding the <body> tag if it doesn't contain "OnUnload", but the page's
3738 The last example is from the fun department:
3740 FILTER: fun Fun text replacements
3742 # Spice the daily news:
3744 s/microsoft(?!\.com)/MicroSuck/ig
3746 Note the (?!\.com) part (a so-called negative lookahead) in the job's pattern,
3747 which means: Don't match, if the string ".com" appears directly following
3748 "microsoft" in the page. This prevents links to microsoft.com from being
3749 trashed, while still replacing the word everywhere else.
3751 # Buzzword Bingo (example for extended regex syntax)
3753 s* industry[ -]leading \
3755 | customer[ -]focused \
3756 | market[ -]driven \
3757 | award[ -]winning # Comments are OK, too! \
3758 | high[ -]performance \
3759 | solutions[ -]based \
3763 *<font color="red"><b>BINGO!</b></font> \
3766 The x option in this job turns on extended syntax, and allows for e.g. the
3767 liberal use of (non-interpreted!) whitespace for nicer formatting.
3771 -------------------------------------------------------------------------------
3775 All Privoxy built-in pages, i.e. error pages such as the "404 - No Such Domain"
3776 error page, the "BLOCKED" page and all pages of its web-based user interface,
3777 are generated from templates. (Privoxy must be running for the above links to
3780 These templates are stored in a subdirectory of the configuration directory
3781 called templates. On Unixish platforms, this is typically /etc/privoxy/
3784 The templates are basically normal HTML files, but with place-holders (called
3785 symbols or exports), which Privoxy fills at run time. You can edit the
3786 templates with a normal text editor, should you want to customize them. (Not
3787 recommended for the casual user). Note that just like in configuration files,
3788 lines starting with # are ignored when the templates are filled in.
3790 The place-holders are of the form @name@, and you will find a list of available
3791 symbols, which vary from template to template, in the comments at the start of
3792 each file. Note that these comments are not always accurate, and that it's
3793 probably best to look at the existing HTML code to find out which symbols are
3794 supported and what they are filled in with.
3796 A special application of this substitution mechanism is to make whole blocks of
3797 HTML code disappear when a specific symbol is set. We use this for many
3798 purposes, one of them being to include the beta warning in all our user
3799 interface (CGI) pages when Privoxy in in an alpha or beta development stage:
3801 <!-- @if-unstable-start -->
3803 ... beta warning HTML code goes here ...
3805 <!-- if-unstable-end@ -->
3807 If the "unstable" symbol is set, everything in between and including
3808 @if-unstable-start and if-unstable-end@ will disappear, leaving nothing but an
3813 There's also an if-then-else construct and an #include mechanism, but you'll
3814 sure find out if you are inclined to edit the templates ;-)
3816 All templates refer to a style located at http://config.privoxy.org/
3817 send-stylesheet. This is, of course, locally served by Privoxy and the source
3818 for it can be found and edited in the cgi-style.css template.
3820 -------------------------------------------------------------------------------
3822 11. Contacting the Developers, Bug Reporting and Feature Requests
3824 We value your feedback. In fact, we rely on it to improve Privoxy and its
3825 configuration. However, please note the following hints, so we can provide you
3826 with the best support:
3828 -------------------------------------------------------------------------------
3832 For casual users, our support forum at SourceForge is probably best suited:
3833 http://sourceforge.net/tracker/?group_id=11118&atid=211118
3835 All users are of course welcome to discuss their issues on the users mailing
3836 list, where the developers also hang around.
3838 -------------------------------------------------------------------------------
3842 Please report all bugs only through our bug tracker: http://sourceforge.net/
3843 tracker/?group_id=11118&atid=111118.
3845 Before doing so, please make sure that the bug has not already been submitted
3846 and observe the additional hints at the top of the submit form.
3848 Please try to verify that it is a Privoxy bug, and not a browser or site bug
3849 first. If unsure, try toggling off Privoxy, and see if the problem persists.
3850 The appendix of the user manual also has helpful information on action
3851 debugging. If you are using your own custom configuration, please try the stock
3852 configs to see if the problem is configuration related.
3854 If not using the latest version, chances are that the bug has been found and
3855 fixed in the meantime. We would appreciate if you could take the time to
3856 upgrade to the latest version (or even the latest CVS snapshot) and verify your
3857 bug, but this is not required for reporting.
3859 -------------------------------------------------------------------------------
3861 11.3. Request New Features
3863 You are welcome to submit ideas on new features or other proposals for
3864 improvement through our feature request tracker at http://sourceforge.net/
3865 tracker/?atid=361118&group_id=11118.
3867 -------------------------------------------------------------------------------
3869 11.4. Report Ads or Other Actions-Related Problems
3871 Please send feedback on ads that slipped through, innocent images that were
3872 blocked, and any other problems relating to the default.action file through our
3873 actions feedback mechanism located at http://www.privoxy.org/actions/. On this
3874 page, you will also find a bookmark which will take you back there from any
3875 troubled site and even pre-fill the form!
3877 New, improved default.action files will occasionally be made available based on
3878 your feedback. These will be announced on the ijbswa-announce list and
3879 available from our the files section of our project page.
3881 -------------------------------------------------------------------------------
3885 For any other issues, feel free to use the mailing lists. Technically
3886 interested users and people who wish to contribute to the project are also
3887 welcome on the developers list! You can find an overview of all Privoxy-related
3888 mailing lists, including list archives, at: http://sourceforge.net/mail/?
3891 -------------------------------------------------------------------------------
3893 12. Privoxy Copyright, License and History
3895 Copyright © 2001, 2002 by Privoxy Developers <developers@privoxy.org>
3897 Some source code is based on code Copyright © 1997 by Anonymous Coders and
3898 Junkbusters, Inc. and licensed under the GNU General Public License.
3900 -------------------------------------------------------------------------------
3904 Privoxy is free software; you can redistribute it and/or modify it under the
3905 terms of the GNU General Public License, version 2, as published by the Free
3906 Software Foundation.
3908 This program is distributed in the hope that it will be useful, but WITHOUT ANY
3909 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
3910 PARTICULAR PURPOSE. See the GNU General Public License for more details, which
3911 is available from the Free Software Foundation, Inc, 59 Temple Place - Suite
3912 330, Boston, MA 02111-1307, USA.
3914 You should have received a copy of the GNU General Public License along with
3915 this program; if not, write to the
3918 Foundation, Inc. 59 Temple Place - Suite 330
3919 Boston, MA 02111-1307
3922 -------------------------------------------------------------------------------
3926 In the beginning, there was the Internet Junkbuster, by Anonymous Coders and
3927 Junkbusters Corporation. It saved many users a lot of pain in the early days of
3928 web advertising and user tracking.
3930 But the web, its protocols and standards, and with it, the techniques for
3931 forcing users to consume ads, give up autonomy over their browsing, and for
3932 spying on them, kept evolving. Unfortunately, the Internet Junkbuster did not.
3933 Version 2.0.2, published in 1998, was (and is) the last official release
3934 available from Junkbusters Corporation. Fortunately, it had been released under
3935 the GNU GPL, which allowed further development by others.
3937 So Stefan Waldherr started maintaining an improved version of the software, to
3938 which eventually a number of people contributed patches. It could already
3939 replace banners with a transparent image, and had a first version of pop-up
3940 killing, but it was still very closely based on the original, with all its
3941 limitations, such as the lack of HTTP/1.1 support, flexible per-site
3942 configuration, or content modification. The last release from this effort was
3943 version 2.0.2-10, published in 2000.
3945 Then, some developers picked up the thread, and started turning the software
3946 inside out, upside down, and then reassembled it, adding many new features
3949 The result of this is Privoxy, whose first stable release, 3.0, was released
3952 -------------------------------------------------------------------------------
3956 Current Project Developers:
3965 Current Project Contributors:
3967 Rodrigo Barbosa (RPM specfiles)
3970 Karsten Hopp (Red Hat)
3975 Roland Rosenfeld (Debian)
3976 Georg Sauthoff (Gentoo)
3977 David Schmidt (OS/2, Mac OSX ports)
3978 Joerg Strohmayer (Amiga)
3981 Based in part on code originally developed by:
3986 Thanks to the many people who have tested Privoxy, reported bugs, or made
3987 suggestions. These include (in alphabetical order):
4007 -------------------------------------------------------------------------------
4011 Other references and sites of interest to Privoxy users:
4013 http://www.privoxy.org/, the Privoxy Home page.
4015 http://www.privoxy.org/faq/, the Privoxy FAQ.
4017 http://sourceforge.net/projects/ijbswa/, the Project Page for Privoxy on
4020 http://config.privoxy.org/, the web-based user interface. Privoxy must be
4021 running for this to work. Shortcut: http://p.p/
4023 http://www.privoxy.org/actions/, to submit "misses" to the developers.
4025 http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/ijbswa/contrib/, cool and fun
4026 ideas from Privoxy users.
4028 http://www.junkbusters.com/ht/en/cookies.html, an explanation how cookies are
4029 used to track web users.
4031 http://www.junkbusters.com/ijb.html, the original Internet Junkbuster.
4033 http://www.waldherr.org/junkbuster/, Stefan Waldherr's version of Junkbuster,
4034 from which Privoxy was derived.
4036 http://privacy.net/analyze/, a useful site to check what information about you
4037 is leaked while you browse the web.
4039 http://www.squid-cache.org/, a very popular caching proxy, which is often used
4040 together with Privoxy.
4042 http://www.privoxy.org/developer-manual/, the Privoxy developer manual.
4044 -------------------------------------------------------------------------------
4048 14.1. Regular Expressions
4050 Privoxy uses Perl-style "regular expressions" in its actions files and filter
4051 file, through the PCRE and PCRS libraries.
4053 If you are reading this, you probably don't understand what "regular
4054 expressions" are, or what they can do. So this will be a very brief
4055 introduction only. A full explanation would require a book ;-)
4057 Regular expressions provide a language to describe patterns that can be run
4058 against strings of characters (letter, numbers, etc), to see if they match the
4059 string or not. The patterns are themselves (sometimes complex) strings of
4060 literal characters, combined with wild-cards, and other special characters,
4061 called meta-characters. The "meta-characters" have special meanings and are
4062 used to build complex patterns to be matched against. Perl Compatible Regular
4063 Expressions are an especially convenient "dialect" of the regular expression
4066 To make a simple analogy, we do something similar when we use wild-card
4067 characters when listing files with the dir command in DOS. *.* matches all
4068 filenames. The "special" character here is the asterisk which matches any and
4069 all characters. We can be more specific and use ? to match just individual
4070 characters. So "dir file?.text" would match "file1.txt", "file2.txt", etc. We
4071 are pattern matching, using a similar technique to "regular expressions"!
4073 Regular expressions do essentially the same thing, but are much, much more
4074 powerful. There are many more "special characters" and ways of building complex
4075 patterns however. Let's look at a few of the common ones, and then some
4078 . - Matches any single character, e.g. "a", "A", "4", ":", or "@".
4080 ? - The preceding character or expression is matched ZERO or ONE times. Either/
4083 + - The preceding character or expression is matched ONE or MORE times.
4085 * - The preceding character or expression is matched ZERO or MORE times.
4087 \ - The "escape" character denotes that the following character should be taken
4088 literally. This is used where one of the special characters (e.g. ".") needs to
4089 be taken literally and not as a special meta-character. Example: "example
4090 \.com", makes sure the period is recognized only as a period (and not expanded
4091 to its meta-character meaning of any single character).
4093 [] - Characters enclosed in brackets will be matched if any of the enclosed
4094 characters are encountered. For instance, "[0-9]" matches any numeric digit
4095 (zero through nine). As an example, we can combine this with "+" to match any
4096 digit one of more times: "[0-9]+".
4098 () - parentheses are used to group a sub-expression, or multiple
4101 | - The "bar" character works like an "or" conditional statement. A match is
4102 successful if the sub-expression on either side of "|" matches. As an example:
4103 "/(this|that) example/" uses grouping and the bar character and would match
4104 either "this example" or "that example", and nothing else.
4106 These are just some of the ones you are likely to use when matching URLs with
4107 Privoxy, and is a long way from a definitive list. This is enough to get us
4108 started with a few simple examples which may be more illuminating:
4110 /.*/banners/.* - A simple example that uses the common combination of "." and "
4111 *" to denote any character, zero or more times. In other words, any string at
4112 all. So we start with a literal forward slash, then our regular expression
4113 pattern (".*") another literal forward slash, the string "banners", another
4114 forward slash, and lastly another ".*". We are building a directory path here.
4115 This will match any file with the path that has a directory named "banners" in
4116 it. The ".*" matches any characters, and this could conceivably be more forward
4117 slashes, so it might expand into a much longer looking path. For example, this
4118 could match: "/eye/hate/spammers/banners/annoy_me_please.gif", or just "/
4119 banners/annoying.html", or almost an infinite number of other possible
4120 combinations, just so it has "banners" in the path somewhere.
4122 A now something a little more complex:
4124 /.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward
4125 slashes again ("/"), so we are building another expression that is a file path
4126 statement. We have another ".*", so we are matching against any conceivable
4127 sub-path, just so it matches our expression. The only true literal that must
4128 match our pattern is adv, together with the forward slashes. What comes after
4129 the "adv" string is the interesting part.
4131 Remember the "?" means the preceding expression (either a literal character or
4132 anything grouped with "(...)" in this case) can exist or not, since this means
4133 either zero or one match. So "((er)?ts?|ertis(ing|ements?))" is optional, as
4134 are the individual sub-expressions: "(er)", "(ing|ements?)", and the "s". The "
4135 |" means "or". We have two of those. For instance, "(ing|ements?)", can expand
4136 to match either "ing" OR "ements?". What is being done here, is an attempt at
4137 matching as many variations of "advertisement", and similar, as possible. So
4138 this would expand to match just "adv", or "advert", or "adverts", or
4139 "advertising", or "advertisement", or "advertisements". You get the idea. But
4140 it would not match "advertizements" (with a "z"). We could fix that by changing
4141 our regular expression to: "/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/", which
4142 would then match either spelling.
4144 /.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward
4145 slashes. Anything in the square brackets "[]" can be matched. This is using
4146 "0-9" as a shorthand expression to mean any digit one through nine. It is the
4147 same as saying "0123456789". So any digit matches. The "+" means one or more of
4148 the preceding expression must be included. The preceding expression here is
4149 what is in the square brackets -- in this case, any digit one through nine.
4150 Then, at the end, we have a grouping: "(gif|jpe?g)". This includes a "|", so
4151 this needs to match the expression on either side of that bar character also. A
4152 simple "gif" on one side, and the other side will in turn match either "jpeg"
4153 or "jpg", since the "?" means the letter "e" is optional and can be matched
4154 once or not at all. So we are building an expression here to match image GIF or
4155 JPEG type image file. It must include the literal string "advert", then one or
4156 more digits, and a "." (which is now a literal, and not a special character,
4157 since it is escaped with "\"), and lastly either "gif", or "jpeg", or "jpg".
4158 Some possible matches would include: "//advert1.jpg", "/nasty/ads/
4159 advert1234.gif", "/banners/from/hell/advert99.jpg". It would not match
4160 "advert1.gif" (no leading slash), or "/adverts232.jpg" (the expression does not
4161 include an "s"), or "/advert1.jsp" ("jsp" is not in the expression anywhere).
4163 We are barely scratching the surface of regular expressions here so that you
4164 can understand the default Privoxy configuration files, and maybe use this
4165 knowledge to customize your own installation. There is much, much more that can
4166 be done with regular expressions. Now that you know enough to get started, you
4167 can learn more on your own :/
4169 More reading on Perl Compatible Regular expressions: http://www.perldoc.com/
4170 perl5.6/pod/perlre.html
4172 For information on regular expression based substitutions and their
4173 applications in filters, please see the filter file tutorial in this manual.
4175 -------------------------------------------------------------------------------
4177 14.2. Privoxy's Internal Pages
4179 Since Privoxy proxies each requested web page, it is easy for Privoxy to trap
4180 certain special URLs. In this way, we can talk directly to Privoxy, and see how
4181 it is configured, see how our rules are being applied, change these rules and
4182 other configuration options, and even turn Privoxy's filtering off, all with a
4185 The URLs listed below are the special ones that allow direct access to Privoxy.
4186 Of course, Privoxy must be running to access these. If not, you will get a
4187 friendly error message. Internet access is not necessary either.
4189 * Privoxy main page:
4191 http://config.privoxy.org/
4193 There is a shortcut: http://p.p/ (But it doesn't provide a fall-back to a
4194 real page, in case the request is not sent through Privoxy)
4196 * Show information about the current configuration, including viewing and
4197 editing of actions files:
4199 http://config.privoxy.org/show-status
4201 * Show the source code version numbers:
4203 http://config.privoxy.org/show-version
4205 * Show the browser's request headers:
4207 http://config.privoxy.org/show-request
4209 * Show which actions apply to a URL and why:
4211 http://config.privoxy.org/show-url-info
4213 * Toggle Privoxy on or off. In this case, "Privoxy" continues to run, but
4214 only as a pass-through proxy, with no actions taking place:
4216 http://config.privoxy.org/toggle
4218 Short cuts. Turn off, then on:
4220 http://config.privoxy.org/toggle?set=disable
4222 http://config.privoxy.org/toggle?set=enable
4224 These may be bookmarked for quick reference. See next.
4226 -------------------------------------------------------------------------------
4228 14.2.1. Bookmarklets
4230 Below are some "bookmarklets" to allow you to easily access a "mini" version of
4231 some of Privoxy's special pages. They are designed for MS Internet Explorer,
4232 but should work equally well in Netscape, Mozilla, and other browsers which
4233 support JavaScript. They are designed to run directly from your bookmarks - not
4234 by clicking the links below (although that should work for testing).
4236 To save them, right-click the link and choose "Add to Favorites" (IE) or "Add
4237 Bookmark" (Netscape). You will get a warning that the bookmark "may not be
4238 safe" - just click OK. Then you can run the Bookmarklet directly from your
4239 favorites/bookmarks. For even faster access, you can put them on the "Links"
4240 bar (IE) or the "Personal Toolbar" (Netscape), and run them with a single
4247 * Privoxy - Toggle Privoxy (Toggles between enabled and disabled)
4249 * Privoxy- View Status
4251 * Privoxy - Submit Actions File Feedback
4255 Credit: The site which gave us the general idea for these bookmarklets is
4256 www.bookmarklets.com. They have more information about bookmarklets.
4258 -------------------------------------------------------------------------------
4260 14.3. Chain of Events
4262 Let's take a quick look at the basic sequence of events when a web page is
4263 requested by your browser and Privoxy is on duty:
4265 * First, your web browser requests a web page. The browser knows to send the
4266 request to Privoxy, which will in turn, relay the request to the remote web
4267 server after passing the following tests:
4269 * Privoxy traps any request for its own internal CGI pages (e.g http://p.p/)
4270 and sends the CGI page back to the browser.
4272 * Next, Privoxy checks to see if the URL matches any "+block" patterns. If
4273 so, the URL is then blocked, and the remote web server will not be
4274 contacted. "+handle-as-image" is then checked and if it does not match, an
4275 HTML "BLOCKED" page is sent back. Otherwise, if it does match, an image is
4276 returned. The type of image depends on the setting of "+set-image-blocker"
4277 (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
4279 * Untrusted URLs are blocked. If URLs are being added to the trust file, then
4282 * If the URL pattern matches the "+fast-redirects" action, it is then
4283 processed. Unwanted parts of the requested URL are stripped.
4285 * Now the rest of the client browser's request headers are processed. If any
4286 of these match any of the relevant actions (e.g. "+hide-user-agent", etc.),
4287 headers are suppressed or forged as determined by these actions and their
4290 * Now the web server starts sending its response back (i.e. typically a web
4291 page and related data).
4293 * First, the server headers are read and processed to determine, among other
4294 things, the MIME type (document type) and encoding. The headers are then
4295 filtered as determined by the "+crunch-incoming-cookies",
4296 "+session-cookies-only", and "+downgrade-http-version" actions.
4298 * If the "+kill-popups" action applies, and it is an HTML or JavaScript
4299 document, the popup-code in the response is filtered on-the-fly as it is
4302 * If a "+filter" or "+deanimate-gifs" action applies (and the document type
4303 fits the action), the rest of the page is read into memory (up to a
4304 configurable limit). Then the filter rules (from default.filter) are
4305 processed against the buffered content. Filters are applied in the order
4306 they are specified in the default.filter file. Animated GIFs, if present,
4307 are reduced to either the first or last frame, depending on the action
4308 setting.The entire page, which is now filtered, is then sent by Privoxy
4309 back to your browser.
4311 If neither "+filter" or "+deanimate-gifs" matches, then Privoxy passes the
4312 raw data through to the client browser as it becomes available.
4314 * As the browser receives the now (probably filtered) page content, it reads
4315 and then requests any URLs that may be embedded within the page source,
4316 e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
4317 frames), sounds, etc. For each of these objects, the browser issues a new
4318 request. And each such request is in turn processed as above. Note that a
4319 complex web page may have many such embedded URLs.
4321 -------------------------------------------------------------------------------
4323 14.4. Anatomy of an Action
4325 The way Privoxy applies actions and filters to any given URL can be complex,
4326 and not always so easy to understand what is happening. And sometimes we need
4327 to be able to see just what Privoxy is doing. Especially, if something Privoxy
4328 is doing is causing us a problem inadvertently. It can be a little daunting to
4329 look at the actions and filters files themselves, since they tend to be filled
4330 with regular expressions whose consequences are not always so obvious.
4332 One quick test to see if Privoxy is causing a problem or not, is to disable it
4333 temporarily. This should be the first troubleshooting step. See the
4334 Bookmarklets section on a quick and easy way to do this (be sure to flush
4335 caches afterward!). Looking at the logs is a good idea too.
4337 Privoxy also provides the http://config.privoxy.org/show-url-info page that can
4338 show us very specifically how actions are being applied to any given URL. This
4339 is a big help for troubleshooting.
4341 First, enter one URL (or partial URL) at the prompt, and then Privoxy will tell
4342 us how the current configuration will handle it. This will not help with
4343 filtering effects (i.e. the "+filter" action) from the default.filter file
4344 since this is handled very differently and not so easy to trap! It also will
4345 not tell you about any other URLs that may be embedded within the URL you are
4346 testing. For instance, images such as ads are expressed as URLs within the raw
4347 page source of HTML pages. So you will only get info for the actual URL that is
4348 pasted into the prompt area -- not any sub-URLs. If you want to know about
4349 embedded URLs like ads, you will have to dig those out of the HTML source. Use
4350 your browser's "View Page Source" option for this. Or right click on the ad,
4353 Let's try an example, google.com, and look at it one section at a time:
4355 Matches for http://google.com:
4357 In file: default.action [ View ] [ Edit ]
4361 -crunch-outgoing-cookies
4362 -crunch-incoming-cookies
4363 +deanimate-gifs{last}
4364 -downgrade-http-version
4368 -filter{shockwave-flash}
4369 -filter{crude-parental}
4370 +filter{html-annoyances}
4371 +filter{js-annoyances}
4372 +filter{content-cookies}
4374 +filter{refresh-tags}
4376 +filter{banners-by-size}
4377 +hide-forwarded-for-headers
4378 +hide-from-header{block}
4379 +hide-referer{forge}
4384 +prevent-compression
4387 +session-cookies-only
4388 +set-image-blocker{pattern} }
4391 { -session-cookies-only }
4397 In file: user.action [ View ] [ Edit ]
4398 (no matches in this file)
4400 This tells us how we have defined our "actions", and which ones match for our
4401 example, "google.com". The first listing is any matches for the standard.action
4402 file. No hits at all here on "standard". Then next is "default", or our
4403 default.action file. The large, multi-line listing, is how the actions are set
4404 to match for all URLs, i.e. our default settings. If you look at your "actions"
4405 file, this would be the section just below the "aliases" section near the top.
4406 This will apply to all URLs as signified by the single forward slash at the end
4407 of the listing -- "/".
4409 But we can define additional actions that would be exceptions to these general
4410 rules, and then list specific URLs (or patterns) that these exceptions would
4411 apply to. Last match wins. Just below this then are two explicit matches for
4412 ".google.com". The first is negating our previous cookie setting, which was for
4413 "+session-cookies-only" (i.e. not persistent). So we will allow persistent
4414 cookies for google. The second turns off any "+fast-redirects" action, allowing
4415 this to take place unmolested. Note that there is a leading dot here --
4416 ".google.com". This will match any hosts and sub-domains, in the google.com
4417 domain also, such as "www.google.com". So, apparently, we have these two
4418 actions defined somewhere in the lower part of our default.action file, and
4419 "google.com" is referenced somewhere in these latter sections.
4421 Then, for our user.action file, we again have no hits.
4423 And finally we pull it all together in the bottom section and summarize how
4424 Privoxy is applying all its "actions" to "google.com":
4430 -crunch-outgoing-cookies
4431 -crunch-incoming-cookies
4432 +deanimate-gifs{last}
4433 -downgrade-http-version
4437 -filter{shockwave-flash}
4438 -filter{crude-parental}
4439 +filter{html-annoyances}
4440 +filter{js-annoyances}
4441 +filter{content-cookies}
4443 +filter{refresh-tags}
4445 +filter{banners-by-size}
4446 +hide-forwarded-for-headers
4447 +hide-from-header{block}
4448 +hide-referer{forge}
4453 +prevent-compression
4456 -session-cookies-only
4457 +set-image-blocker{pattern}
4459 Notice the only difference here to the previous listing, is to "fast-redirects"
4460 and "session-cookies-only".
4462 Now another example, "ad.doubleclick.net":
4464 { +block +handle-as-image }
4467 { +block +handle-as-image }
4470 { +block +handle-as-image }
4473 We'll just show the interesting part here, the explicit matches. It is matched
4474 three different times. Each as an "+block +handle-as-image", which is the
4475 expanded form of one of our aliases that had been defined as: "+imageblock". (
4476 "Aliases" are defined in the first section of the actions file and typically
4477 used to combine more than one action.)
4479 Any one of these would have done the trick and blocked this as an unwanted
4480 image. This is unnecessarily redundant since the last case effectively would
4481 also cover the first. No point in taking chances with these guys though ;-)
4482 Note that if you want an ad or obnoxious URL to be invisible, it should be
4483 defined as "ad.doubleclick.net" is done here -- as both a "+block" and an
4484 "+handle-as-image". The custom alias "+imageblock" just simplifies the process
4485 and make it more readable.
4487 One last example. Let's try "http://www.rhapsodyk.net/adsl/HOWTO/". This one is
4488 giving us problems. We are getting a blank page. Hmmm ...
4490 Matches for http://www.rhapsodyk.net/adsl/HOWTO/:
4492 In file: default.action [ View ] [ Edit ]
4496 -crunch-incoming-cookies
4497 -crunch-outgoing-cookies
4499 -downgrade-http-version
4501 +filter{html-annoyances}
4502 +filter{js-annoyances}
4503 +filter{kill-popups}
4506 +filter{banners-by-size}
4509 +hide-forwarded-for-headers
4510 +hide-from-header{block}
4511 +hide-referer{forge}
4515 +prevent-compression
4518 +session-cookies-only
4519 +set-image-blocker{blank} }
4522 { +block +handle-as-image }
4525 Ooops, the "/adsl/" is matching "/ads"! But we did not want this at all! Now we
4526 see why we get the blank page. We could now add a new action below this that
4527 explicitly does not block ("{-block}") paths with "adsl". There are various
4528 ways to handle such exceptions. Example:
4533 Now the page displays ;-) Be sure to flush your browser's caches when making
4534 such changes. Or, try using Shift+Reload.
4536 But now what about a situation where we get no explicit matches like we did
4539 { +block +handle-as-image }
4542 That actually was very telling and pointed us quickly to where the problem was.
4543 If you don't get this kind of match, then it means one of the default rules in
4544 the first section is causing the problem. This would require some guesswork,
4545 and maybe a little trial and error to isolate the offending rule. One likely
4546 cause would be one of the "{+filter}" actions. These tend to be harder to
4547 troubleshoot. Try adding the URL for the site to one of aliases that turn off
4552 .worldpay.com # for quietpc.com
4557 "{shop}" is an "alias" that expands to "{ -filter -session-cookies-only }". Or
4558 you could do your own exception to negate filtering:
4563 This would turn off all filtering for that site. This would probably be most
4564 appropriately put in user.action, for local site exceptions.
4566 Images that are inexplicably being blocked, may well be hitting the "+filter
4567 {banners-by-size}" rule, which assumes that images of certain sizes are ad
4568 banners (works well most of the time since these tend to be standardized).
4570 "{fragile}" is an alias that disables most actions. This can be used as a last
4571 resort for problem sites. Remember to flush caches! If this still does not
4572 work, you will have to go through the remaining actions one by one to find
4573 which one(s) is causing the problem.
projects / privoxy.git / blob