1 Privoxy 2.9.16 User Manual
3 Copyright © 2001, 2002 by Privoxy Developers
5 $Id: user-manual.sgml,v 1.123.2.11 2002/07/26 15:20:31 oes Exp $
8 The User Manual gives users information on how to install, configure and use
11 Privoxy is a web proxy with advanced filtering capabilities for protecting
12 privacy, filtering web page content, managing cookies, controlling access, and
13 removing ads, banners, pop-ups and other obnoxious Internet junk. Privoxy has a
14 very flexible configuration and can be customized to suit individual needs and
15 tastes. Privoxy has application for both stand-alone systems and multi-user
18 Privoxy is based on Internet Junkbuster (tm).
20 You can find the latest version of the User Manual at http://www.privoxy.org/
21 user-manual/. Please see the Contact section on how to contact the developers.
23 -------------------------------------------------------------------------------
31 2.1.1. Red Hat, SuSE and Conectiva RPMs
34 2.1.4. Solaris, NetBSD, FreeBSD, HP-UX
40 2.2. Building from Source
41 2.3. Keeping your Installation Up-to-Date
45 4. Quickstart to Using Privoxy
46 4.1. Quickstart to Ad Blocking
50 5.1. Red Hat and Conectiva
54 5.5. Solaris, NetBSD, FreeBSD, HP-UX and others
58 5.9. Command Line Options
61 6. Privoxy Configuration
62 6.1. Controlling Privoxy with Your Web Browser
63 6.2. Configuration Files Overview
66 7. The Main Configuration File
67 7.1. Configuration and Log File Locations
77 7.2. Local Set-up Documentation
86 7.3.2. single-threaded
89 7.4. Access Control and Security
92 7.4.3. enable-remote-toggle
93 7.4.4. enable-edit-actions
94 7.4.5. ACLs: permit-access and deny-access
100 7.5.2. forward-socks4 and forward-socks4a
101 7.5.3. Advanced Forwarding Examples
104 7.6. Windows GUI Options
108 8.1. Finding the Right Mix
110 8.3. How Actions are Applied to URLs
113 8.4.1. The Domain Pattern
114 8.4.2. The Path Pattern
120 8.5.3. crunch-incoming-cookies
121 8.5.4. crunch-outgoing-cookies
122 8.5.5. deanimate-gifs
123 8.5.6. downgrade-http-version
124 8.5.7. fast-redirects
126 8.5.9. handle-as-image
127 8.5.10. hide-forwarded-for-headers
128 8.5.11. hide-from-header
129 8.5.12. hide-referrer
130 8.5.13. hide-user-agent
132 8.5.15. limit-connect
133 8.5.16. prevent-compression
134 8.5.17. send-vanilla-wafer
136 8.5.19. session-cookies-only
137 8.5.20. set-image-blocker
142 8.7. Actions Files Tutorial
143 8.7.1. default.action
150 9.1. Filter File Tutorial
154 11. Contacting the Developers, Bug Reporting and Feature Requests
157 11.3. Request New Features
158 11.4. Report Ads or Other Actions-Related Problems
162 12. Privoxy Copyright, License and History
170 14.1. Regular Expressions
171 14.2. Privoxy's Internal Pages
175 14.3. Chain of Events
176 14.4. Anatomy of an Action
182 This documentation is included with the current beta version of Privoxy,
183 v.2.9.16, and is mostly complete at this point. The most up to date reference
184 for the time being is still the comments in the source files and in the
185 individual configuration files. Development of version 3.0 is currently nearing
186 completion, and includes many significant changes and enhancements over earlier
187 versions. The target release date for stable v3.0 is "soon" ;-).
189 Since this is a beta version, not all new features are well tested. This
190 documentation may be slightly out of sync as a result (especially with CVS
191 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
239 -------------------------------------------------------------------------------
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.
251 -------------------------------------------------------------------------------
255 How to install the binary packages depends on your operating system:
256 -------------------------------------------------------------------------------
258 2.1.1. Red Hat, SuSE and Conectiva RPMs
260 RPMs can be installed with rpm -Uvh privoxy-2.9.16-1.rpm, and will use /etc/
261 privoxy for the location of configuration files.
263 Note that on Red Hat, Privoxy will not be automatically started on system boot.
264 You will need to enable that using chkconfig, ntsysv, or similar methods. Note
265 that SuSE will automatically start Privoxy in the boot process.
267 If you have problems with failed dependencies, try rebuilding the SRC RPM: rpm
268 --rebuild privoxy-2.9.16-1.src.rpm. This will use your locally installed
269 libraries and RPM version.
271 Also note that if you have a Junkbuster RPM installed on your system, you need
272 to remove it first, because the packages conflict. Otherwise, RPM will try to
273 remove Junkbuster automatically, before installing Privoxy.
274 -------------------------------------------------------------------------------
278 DEBs can be installed with dpkg -i privoxy_2.9.16-1.deb, and will use /etc/
279 privoxy for the location of configuration files.
280 -------------------------------------------------------------------------------
284 Just double-click the installer, which will guide you through the installation
285 process. You will find the configuration files in the same directory as you
286 installed Privoxy in. We do not use the registry of Windows.
287 -------------------------------------------------------------------------------
289 2.1.4. Solaris, NetBSD, FreeBSD, HP-UX
291 Create a new directory, cd to it, then unzip and untar the archive. For the
292 most part, you'll have to figure out where things go.
293 -------------------------------------------------------------------------------
297 First, make sure that no previous installations of Junkbuster and / or Privoxy
298 are left on your system. Check that no Junkbuster or Privoxy objects are in
301 Then, just double-click the WarpIN self-installing archive, which will guide
302 you through the installation process. A shadow of the Privoxy executable will
303 be placed in your startup folder so it will start automatically whenever OS/2
306 The directory you choose to install Privoxy into will contain all of the
308 -------------------------------------------------------------------------------
312 Unzip the downloaded package (you can either double-click on the file in the
313 finder, or on the desktop if you downloaded it there). The Privoxy.pkg package
314 should appear after unzipping. Then, double-click on that Privoxy.pkg package
315 installer icon and follow the installation process. Privoxy will be installed
316 in the folder /Library/Privoxy. It will run automatically whenever you start
317 up. To prevent it from running automatically, remove or rename the folder /
318 Library/StartupItems/Privoxy.
320 To run Privoxy by hand, double-click on RunPrivoxy.command. To run Privoxy from
321 Terminal, execute /Library/Privoxy/RunPrivoxy.command.
322 -------------------------------------------------------------------------------
326 Copy and then unpack the lha archive to a suitable location. All necessary
327 files will be installed into Privoxy directory, including all configuration and
328 log files. To uninstall, just remove this directory.
329 -------------------------------------------------------------------------------
331 2.2. Building from Source
333 The most convenient way to obtain the Privoxy sources is to download the source
334 tarball from our project page.
336 If you like to live on the bleeding edge and are not afraid of using possibly
337 unstable development versions, you can check out the up-to-the-minute version
338 directly from the CVS repository or simply download the nightly CVS tarball.
340 To build Privoxy from source, autoconf, GNU make (gmake), and, of course, a C
341 compiler like gcc are required.
343 When building from a source tarball (either release version or nightly CVS
344 tarball), first unpack the source:
346 tar xzvf privoxy-2.9.16-beta-src* [.tgz or .tar.gz]
347 cd privoxy-2.9.16-beta
349 For retrieving the current CVS sources, you'll need CVS installed. Note that
350 sources from CVS are development quality, and may not be stable, or well
351 tested. To download CVS source:
353 cvs -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa login
354 cvs -z3 -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa co current
357 This will create a directory named current/, which will contain the source
360 Then, in either case, to build from unpacked tarball or CVS source:
364 ./configure # (--help to see options)
365 make # (the make from gnu, gmake for *BSD)
367 make -n install # (to see where all the files will go)
368 make install # (to really install)
370 If you have gnu make, you can have the first four steps automatically done for
375 in the freshly downloaded or unpacked source directory.
377 For more detailed instructions on how to build Redhat and SuSE RPMs, Windows
378 self-extracting installers, building on platforms with special requirements
379 etc, please consult the developer manual.
380 -------------------------------------------------------------------------------
382 2.3. Keeping your Installation Up-to-Date
384 As user feedback comes in and development continues, we will make updated
385 versions of both the software and the main actions file (default.action)
386 available for download.
388 If you wish to receive an email notification whenever we release updates of
389 Privoxy or the actions file, subscribe to our announce mailing list,
390 ijbswa-announce@lists.sourceforge.net.
392 Both can be downloaded from the files section on SourceForge.
394 In order not to loose your personal changes and adjustments when updating to
395 the latest default.action file we strongly recommend that you use user.action
396 for your customization of Privoxy. See the Chapter on actions files for
398 -------------------------------------------------------------------------------
402 There are very significant changes from earlier Junkbuster versions to the
403 current Privoxy. The number, names, syntax, and purposes of configuration files
404 have substantially changed. Junkbuster 2.0.x configuration files will not
405 migrate, Junkbuster 2.9.x and Privoxy configurations will need to be ported.
406 The functionalities of the old blockfile, cookiefile and imagelist are now
407 combined into the "actions files". default.action, is the main actions file.
408 Local exceptions should best be put into user.action.
410 A "filter file" (typically default.filter) is new as of Privoxy 2.9.x, and
411 provides some of the new sophistication (explained below). config is much the
414 If upgrading from a 2.0.x version, you will have to use the new config files,
415 and possibly adapt any personal rules from your older files. When porting
416 personal rules over from the old blockfile to the new actions files, please
417 note that even the pattern syntax has changed. If upgrading from 2.9.x
418 development versions, it is still recommended to use the new configuration
421 A quick list of things to be aware of before upgrading:
423 * The default listening port is now 8118 due to a conflict with another
426 * Some installers may remove earlier versions completely. Save any important
429 * Privoxy is controllable with a web browser at the special URL: http://
430 config.privoxy.org/ (Shortcut: http://p.p/). Many aspects of configuration
431 can be done here, including temporarily disabling Privoxy.
433 * The primary configuration files for cookie management, ad and banner
434 blocking, and many other aspects of Privoxy configuration are the actions
435 files. It is strongly recommended to become familiar with the new actions
436 concept below, before modifying these files. Locally defined rules should
439 * Some installers may not automatically start Privoxy after installation.
442 -------------------------------------------------------------------------------
443 4. Quickstart to Using Privoxy
445 * If upgrading, from versions before 2.9.16, please back up any configuration
446 files. See the Note to Upgraders Section.
448 * Install Privoxy. See the Installation Section below for platform specific
451 * Advanced users and those who want to offer Privoxy service to more than
452 just their local machine should check the main config file, especially the
453 security-relevant options. These are off by default.
455 * Start Privoxy, if the installation program has not done this already (may
456 vary according to platform). See the section Starting Privoxy.
458 * Set your browser to use Privoxy as HTTP and HTTPS proxy by setting the
459 proxy configuration for address of 127.0.0.1 and port 8118. (Junkbuster and
460 earlier versions of Privoxy used port 8000.) See the section Starting
461 Privoxy below for more details on this.
463 * Flush your browser's disk and memory caches, to remove any cached ad
466 * A default installation should provide a reasonable starting point for most.
467 There will undoubtedly be occasions where you will want to adjust the
468 configuration, but that can be dealt with as the need arises. Little to no
469 initial configuration is required in most cases.
471 See the Configuration section for more configuration options, and how to
472 customize your installation.
474 * If you experience ads that slipped through, innocent images that are
475 blocked, or otherwise feel the need to fine-tune Privoxy's behaviour, take
476 a look at the actions files. As a quick start, you might find the richly
477 commented examples helpful. You can also view and edit the actions files
478 through the web-based user interface. The Appendix "Anatomy of an Action"
479 has hints how to debug actions that "misbehave".
481 * Please see the section Contacting the Developers on how to report bugs or
482 problems with websites or to get help.
484 * Now enjoy surfing with enhanced comfort and privacy!
487 -------------------------------------------------------------------------------
488 4.1. Quickstart to Ad Blocking
490 Ad blocking is but one of Privoxy's array of features. Many of these features
491 are for the technically minded advanced user. But, ad and banner blocking is
492 surely common ground for everybody.
494 This section will provide a quick summary of ad blocking so you can get up to
495 speed quickly without having to read the more extensive information provided
496 below, though this is highly recommended.
498 First a bit of a warning ... blocking ads is much like blocking SPAM: the more
499 aggressive you are about it, the more likely you are to block things that were
500 not intended. So there is a trade off here. If you want extreme ad free
501 browsing, be prepared to deal with more "problem" sites, and to spend more time
502 adjusting the configuration to solve these unintended consequences. In short,
503 there is not an easy way to eliminate all ads. Either take the easy way and
504 settle for most ads blocked with the default configuration, or jump in and
505 tweak it for your personal surfing habits and preferences.
507 Secondly, a brief explanation of Privoxy's "actions". "Actions" in this
508 context, are the directives we use to tell Privoxy to perform some task
509 relating to HTTP transactions (i.e. web browsing). We tell Privoxy to take some
510 "action". Each action has a unique name and function. While there are many
511 potential actions in Privoxy's arsenal, only a few are used for ad blocking.
512 Actions, and action configuration files, are explained in depth below.
514 Actions are specified in Privoxy's configuration, followed by one or more URLs
515 to which the action should apply. URLs can actually be URL type patterns that
516 use wildcards so they can apply potentially to a range of similar URLs. The
517 actions, together with the URL patterns are called a section.
519 When you connect to a website, the full URL will either match one or more of
520 the sections as defined in Privoxy's configuration, or not. If so, then Privoxy
521 will perform the respective actions. If not, then nothing special happens.
522 Furthermore, web pages may contain embedded, secondary URLs that your web
523 browser will use to load additional components of the page, as it parses the
524 original page's HTML content. An ad image for instance, is just an URL embedded
525 in the page somewhere. The image itself may be on the same server, or a server
526 somewhere else on the Internet. Complex web pages will have many such embedded
529 The actions we need to know about for ad blocking are: block, handle-as-image,
530 and set-image-blocker:
532 * block - this action stops any contact between your browser and any URL
533 patterns that match this action's configuration. It can be used for
534 blocking ads, but also anything that is determined to be unwanted. By
535 itself, it simply stops any communication with the remote server and sends
536 Privoxy's own built-in BLOCKED page instead to let you now what has
539 * handle-as-image - tells Privoxy to treat this URL as an image. Privoxy's
540 default configuration already does this for all common image types (e.g.
541 GIF), but there are many situations where this is not so easy to determine.
542 So we'll force it in these cases. This is particularly important for ad
543 blocking, since only if we know that it's an image of some kind, can we
544 replace it with an image of our choosing, instead of the Privoxy BLOCKED
545 page (which would only result in a "broken image" icon). There are some
546 limitations to this though. For instance, you can't just brute-force an
547 image substitution for an entire HTML page in most situations.
549 * set-image-blocker - tells Privoxy what to display in place of an ad image
550 that has hit a block rule. For this to come into play, the URL must match a
551 block action somewhere in the configuration, and, it must also match an
552 handle-as-image action.
554 The configuration options on what to display instead of the ad are:
556 pattern - a checkerboard pattern, so that an ad replacement is obvious.
559 blank - A very small empty GIF image is displayed. This is the so-called
560 "invisible" configuration option.
562 http://<URL> - A redirect to any image anywhere of the user's choosing
567 The quickest way to adjust any of these settings is with your browser through
568 the special Privoxy editor at http://config.privoxy.org/show-status (shortcut:
569 http://p.p/show-status). This is an internal page, and does not require
570 Internet access. Select the appropriate "actions" file, and click "Edit". It is
571 best to put personal or local preferences in user.action since this is not
572 meant to be overwritten during upgrades, and will over-ride the settings in
573 other files. Here you can insert new "actions", and URLs for ad blocking or
574 other purposes, and make other adjustments to the configuration. Privoxy will
575 detect these changes automatically.
577 A quick and simple step by step example:
579 * Right click on the ad image to be blocked, then select "Copy Link Location"
580 from the pop-up menu.
582 * Set your browser to http://config.privoxy.org/show-status
584 * Find user.action in the top section, and click on "Edit":
586 Figure 1. Actions Files in Use
588 [ Screenshot of Actions Files in Use ]
590 * You should have a section with only block listed under "Actions:". If not,
591 click a "Insert new section below" button, and in the new section that just
592 appeared, click the Edit button right under the word "Actions:". This will
593 bring up a list of all actions. Find block near the top, and click in the
594 "Enabled" column, then "Submit" just below the list.
596 * Now, in the block actions section, click the "Add" button, and paste the
597 URL the browser got from "Copy Link Location". Remove the http:// at the
598 beginning of the URL. Then, click "Submit" (or "OK" if in a pop-up window).
600 * Now go back to the original page, and press SHIFT-Reload (or flush all
601 browser caches). The image should be gone now.
604 This is a very crude and simple example. There might be good reasons to use a
605 wildcard pattern match to include potentially similar images from the same
606 site. For a more extensive explanation of "patterns", and the entire actions
607 concept, see the Actions section.
609 For advanced users who want to hand edit their config files, you might want to
610 now go to the Actions Files Tutorial. The ideas explained therein also apply to
611 the web-based editor.
612 -------------------------------------------------------------------------------
616 Before launching Privoxy for the first time, you will want to configure your
617 browser(s) to use Privoxy as a HTTP and HTTPS proxy. The default is 127.0.0.1
618 (or localhost) for the proxy address, and port 8118 (earlier versions used port
619 8000). This is the one configuration step that must be done!
621 Please note that Privoxy can only proxy HTTP and HTTPS traffic. It will not
622 work with FTP or other protocols.
624 Figure 2. Proxy Configuration (Mozilla)
626 [ Screenshot of Mozilla Proxy Configuration ]
628 With Netscape (and Mozilla), this can be set under:
640 For Internet Explorer:
650 Then, check "Use Proxy" and fill in the appropriate info (Address: 127.0.0.1,
651 Port: 8118). Include HTTPS (SSL), if you want HTTPS proxy support too.
653 After doing this, flush your browser's disk and memory caches to force a
654 re-reading of all pages and to get rid of any ads that may be cached. You are
655 now ready to start enjoying the benefits of using Privoxy!
657 Privoxy is typically started by specifying the main configuration file to be
658 used on the command line. If no configuration file is specified on the command
659 line, Privoxy will look for a file named config in the current directory.
660 Except on Win32 where it will try config.txt.
661 -------------------------------------------------------------------------------
663 5.1. Red Hat and Conectiva
665 We use a script. Note that Red Hat does not start Privoxy upon booting per
666 default. It will use the file /etc/privoxy/config as its main configuration
669 # /etc/rc.d/init.d/privoxy start
670 -------------------------------------------------------------------------------
674 We use a script. Note that Debian starts Privoxy upon booting per default. It
675 will use the file /etc/privoxy/config as its main configuration file.
677 # /etc/init.d/privoxy start
678 -------------------------------------------------------------------------------
682 We use a script. It will use the file /etc/privoxy/config as its main
683 configuration file. Note that SuSE starts Privoxy upon booting your PC.
686 -------------------------------------------------------------------------------
690 Click on the Privoxy Icon to start Privoxy. If no configuration file is
691 specified on the command line, Privoxy will look for a file named config.txt.
692 Note that Windows will automatically start Privoxy upon booting you PC.
693 -------------------------------------------------------------------------------
695 5.5. Solaris, NetBSD, FreeBSD, HP-UX and others
697 Example Unix startup command:
699 # /usr/sbin/privoxy /etc/privoxy/config
700 -------------------------------------------------------------------------------
704 During installation, Privoxy is configured to start automatically when the
705 system restarts. You can start it manually by double-clicking on the Privoxy
706 icon in the Privoxy folder.
707 -------------------------------------------------------------------------------
711 During installation, Privoxy is configured to start automatically when the
712 system restarts. To run Privoxy by hand, double-click on the RunPrivoxy.command
713 icon in the /Library/Privoxy folder. Or, type this command in the Terminal:
715 /Library/Privoxy/RunPrivoxy.command
718 If you are not logged in as an administrator, you will be asked for the
719 administrator password when starting Privoxy by hand.
720 -------------------------------------------------------------------------------
724 Start Privoxy (with RUN <>NIL:) in your startnet script (AmiTCP), in s:
725 user-startup (RoadShow), as startup program in your startup script (Genesis),
726 or as startup action (Miami and MiamiDx). Privoxy will automatically quit when
727 you quit your TCP/IP stack (just ignore the harmless warning your TCP/IP stack
728 may display that Privoxy is still running).
729 -------------------------------------------------------------------------------
731 5.9. Command Line Options
733 Privoxy may be invoked with the following command-line options:
737 Print version info and exit. Unix only.
741 Print short usage info and exit. Unix only.
745 Don't become a daemon, i.e. don't fork and become process group leader, and
746 don't detach from controlling tty. Unix only.
750 On startup, write the process ID to FILE. Delete the FILE on exit. Failure
751 to create or delete the FILE is non-fatal. If no FILE option is given, no
752 PID file will be used. Unix only.
754 * --user USER[.GROUP]
756 After (optionally) writing the PID file, assume the user ID of USER, and if
757 included the GID of GROUP. Exit if the privileges are not sufficient to do
762 If no configfile is included on the command line, Privoxy will look for a
763 file named "config" in the current directory (except on Win32 where it will
764 look for "config.txt" instead). Specify full path to avoid confusion. If no
765 config file is found, Privoxy will fail to start.
768 -------------------------------------------------------------------------------
769 6. Privoxy Configuration
771 All Privoxy configuration is stored in text files. These files can be edited
772 with a text editor. Many important aspects of Privoxy can also be controlled
773 easily with a web browser.
774 -------------------------------------------------------------------------------
776 6.1. Controlling Privoxy with Your Web Browser
778 Privoxy's user interface can be reached through the special URL http://
779 config.privoxy.org/ (shortcut: http://p.p/), which is a built-in page and works
780 without Internet access. You will see the following section:
782 ?? View & change the current configuration
783 ?? View the source code version numbers
784 ?? View the request headers.
785 ?? Look up which actions apply to a URL and why
786 ?? Toggle Privoxy on or off
788 This should be self-explanatory. Note the first item leads to an editor for the
789 actions files, which is where the ad, banner, cookie, and URL blocking magic is
790 configured as well as other advanced features of Privoxy. This is an easy way
791 to adjust various aspects of Privoxy configuration. The actions file, and other
792 configuration files, are explained in detail below.
794 "Toggle Privoxy On or Off" is handy for sites that might have problems with
795 your current actions and filters. You can in fact use it as a test to see
796 whether it is Privoxy causing the problem or not. Privoxy continues to run as a
797 proxy in this case, but all manipulation is disabled, i.e. Privoxy acts like a
798 normal forwarding proxy. There is even a toggle Bookmarklet offered, so that
799 you can toggle Privoxy with one click from your browser.
800 -------------------------------------------------------------------------------
802 6.2. Configuration Files Overview
804 For Unix, *BSD and Linux, all configuration files are located in /etc/privoxy/
805 by default. For MS Windows, OS/2, and AmigaOS these are all in the same
806 directory as the Privoxy executable. The name and number of configuration files
807 has changed from previous versions, and is subject to change as development
810 The installed defaults provide a reasonable starting point, though some
811 settings may be aggressive by some standards. For the time being, the principle
812 configuration files are:
814 * The main configuration file is named config on Linux, Unix, BSD, OS/2, and
815 AmigaOS and config.txt on Windows. This is a required file.
817 * default.action (the main actions file) is used to define which "actions"
818 relating to banner-blocking, images, pop-ups, content modification, cookie
819 handling etc should be applied by default. It also defines many exceptions
820 (both positive and negative) from this default set of actions that enable
821 Privoxy to selectively eliminate the junk, and only the junk, on as many
822 websites as possible.
824 Multiple actions files may be defined in config. These are processed in the
825 order they are defined. Local customizations and locally preferred
826 exceptions to the default policies as defined in default.action (which you
827 will most probably want to define sooner or later) are probably best
828 applied in user.action, where you can preserve them across upgrades.
829 standard.action is for Privoxy's internal use.
831 There is also a web based editor that can be accessed from http://
832 config.privoxy.org/show-status (Shortcut: http://p.p/show-status) for the
833 various actions files.
835 * default.filter (the filter file) can be used to re-write the raw page
836 content, including viewable text as well as embedded HTML and JavaScript,
837 and whatever else lurks on any given web page. The filtering jobs are only
838 pre-defined here; whether to apply them or not is up to the actions files.
841 All files use the "#" character to denote a comment (the rest of the line will
842 be ignored) and understand line continuation through placing a backslash ("\")
843 as the very last character in a line. If the # is preceded by a backslash, it
844 looses its special function. Placing a # in front of an otherwise valid
845 configuration line to prevent it from being interpreted is called "commenting
848 The actions files and default.filter can use Perl style regular expressions for
851 After making any changes, there is no need to restart Privoxy in order for the
852 changes to take effect. Privoxy detects such changes automatically. Note,
853 however, that it may take one or two additional requests for the change to take
854 effect. When changing the listening address of Privoxy, these "wake up"
855 requests must obviously be sent to the old listening address.
857 While under development, the configuration content is subject to change. The
858 below documentation may not be accurate by the time you read this. Also, what
859 constitutes a "default" setting, may change, so please check all your
860 configuration files on important issues.
861 -------------------------------------------------------------------------------
863 7. The Main Configuration File
865 Again, the main configuration file is named config on Linux/Unix/BSD and OS/2,
866 and config.txt on Windows. Configuration lines consist of an initial keyword
867 followed by a list of values, all separated by whitespace (any number of spaces
868 or tabs). For example:
872 Assigns the value /etc/privoxy to the option confdir and thus indicates that
873 the configuration directory is named "/etc/privoxy/".
875 All options in the config file except for confdir and logdir are optional.
876 Watch out in the below description for what happens if you leave them unset.
878 The main config file controls all aspects of Privoxy's operation that are not
879 location dependent (i.e. they apply universally, no matter where you may be
881 -------------------------------------------------------------------------------
883 7.1. Configuration and Log File Locations
885 Privoxy can (and normally does) use a number of other files for additional
886 configuration, help and logging. This section of the configuration file tells
887 Privoxy where to find those other files.
889 The user running Privoxy, must have read permission for all configuration
890 files, and write permission to any files that would be modified, such as log
891 files and actions files.
892 -------------------------------------------------------------------------------
897 The directory where the other configuration files are located
903 /etc/privoxy (Unix) or Privoxy installation dir (Windows)
909 No trailing "/", please
911 When development goes modular and multi-user, the blocker, filter, and
912 per-user config will be stored in subdirectories of "confdir". For now, the
913 configuration directory structure is flat, except for confdir/templates,
914 where the HTML templates for CGI output reside (e.g. Privoxy's 404 error
918 -------------------------------------------------------------------------------
922 The directory where all logging takes place (i.e. where logfile and jarfile
929 /var/log/privoxy (Unix) or Privoxy installation dir (Windows)
935 No trailing "/", please
938 -------------------------------------------------------------------------------
942 The actions file(s) to use
945 File name, relative to confdir, without the .action suffix
948 standard # Internal purposes, no editing recommended
949 default # Main actions file
950 user # User customizations
954 No actions are taken at all. Simple neutral proxying.
957 Multiple actionsfile lines are permitted, and are in fact recommended!
959 The default values include standard.action, which is used for internal
960 purposes and should be loaded, default.action, which is the "main" actions
961 file maintained by the developers, and user.action, where you can make your
964 Actions files are where all the per site and per URL configuration is done
965 for ad blocking, cookie management, privacy considerations, etc. There is
966 no point in using Privoxy without at least one actions file.
969 -------------------------------------------------------------------------------
973 The filter file to use
976 File name, relative to confdir
979 default.filter (Unix) or default.filter.txt (Windows)
982 No textual content filtering takes place, i.e. all +filter{name} actions in
983 the actions files are turned neutral.
986 The filter file contains content modification rules that use regular
987 expressions. These rules permit powerful changes on the content of Web
988 pages, e.g., you could disable your favorite JavaScript annoyances,
989 re-write the actual displayed text, or just have some fun replacing
990 "Microsoft" with "MicroSuck" wherever it appears on a Web page.
992 The +filter{name} actions rely on the relevant filter (name) to be defined
995 A pre-defined filter file called default.filter that contains a bunch of
996 handy filters for common problems is included in the distribution. See the
997 section on the filter action for a list.
1000 -------------------------------------------------------------------------------
1007 File name, relative to logdir
1010 logfile (Unix) or privoxy.log (Windows)
1013 No log file is used, all log messages go to the console (STDERR).
1016 The windows version will additionally log to the console.
1018 The logfile is where all logging and error messages are written. The level
1019 of detail and number of messages are set with the debug option (see below).
1020 The logfile can be useful for tracking down a problem with Privoxy (e.g.,
1021 it's not blocking an ad you think it should block) but in most cases you
1022 probably will never look at it.
1024 Your logfile will grow indefinitely, and you will probably want to
1025 periodically remove it. On Unix systems, you can do this with a cron job
1026 (see "man cron"). For Red Hat, a logrotate script has been included.
1028 On SuSE Linux systems, you can place a line like "/var/log/privoxy.* +1024k
1029 644 nobody.nogroup" in /etc/logfiles, with the effect that cron.daily will
1030 automatically archive, gzip, and empty the log, when it exceeds 1M size.
1032 Any log files must be writable by whatever user Privoxy is being run as
1033 (default on UNIX, user id is "privoxy").
1036 -------------------------------------------------------------------------------
1040 The file to store intercepted cookies in
1043 File name, relative to logdir
1046 jarfile (Unix) or privoxy.jar (Windows)
1049 Intercepted cookies are not stored at all.
1052 The jarfile may grow to ridiculous sizes over time.
1055 -------------------------------------------------------------------------------
1059 The trust file to use
1062 File name, relative to confdir
1065 Unset (commented out). When activated: trust (Unix) or trust.txt (Windows)
1068 The whole trust mechanism is turned off.
1071 The trust mechanism is an experimental feature for building white-lists and
1072 should be used with care. It is NOT recommended for the casual user.
1074 If you specify a trust file, Privoxy will only allow access to sites that
1075 are named in the trustfile. You can also mark sites as trusted referrers
1076 (with +), with the effect that access to untrusted sites will be granted,
1077 if a link from a trusted referrer was used. The link target will then be
1078 added to the "trustfile". Possible applications include limiting Internet
1079 access for children.
1081 If you use + operator in the trust file, it may grow considerably over
1085 -------------------------------------------------------------------------------
1086 7.2. Local Set-up Documentation
1088 If you intend to operate Privoxy for more users than just yourself, it might be
1089 a good idea to let them know how to reach you, what you block and why you do
1090 that, your policies, etc.
1091 -------------------------------------------------------------------------------
1096 Location of the Privoxy User Manual.
1099 A fully qualified URI
1105 http://www.privoxy.org/version/user-manual/ will be used, where version is
1106 the Privoxy version.
1109 The User Manual URI is used for help links from some of the internal CGI
1110 pages. The manual itself is normally packaged with the binary
1111 distributions, so you probably want to set this to a locally installed
1112 copy. For multi-user setups, you could provide a copy on a local webserver
1113 for all your users and use the corresponding URL here.
1117 Unix, in local filesystem:
1119 user-manual file:///usr/share/doc/privoxy-2.9.16/user-manual/
1121 Any platform, on local webserver (called "local-webserver"):
1123 user-manual http://local-webserver/privoxy-user-manual/
1125 +-----------------------------------------------------------------+
1127 +-----------------------------------------------------------------+
1128 |If set, this option should be the first option in the config |
1129 |file, because it is used while the config file is being read. |
1130 +-----------------------------------------------------------------+
1133 -------------------------------------------------------------------------------
1134 7.2.2. trust-info-url
1137 A URL to be displayed in the error page that users will see if access to an
1138 untrusted page is denied.
1144 Two example URL are provided
1147 No links are displayed on the "untrusted" error page.
1150 The value of this option only matters if the experimental trust mechanism
1151 has been activated. (See trustfile above.)
1153 If you use the trust mechanism, it is a good idea to write up some on-line
1154 documentation about your trust policy and to specify the URL(s) here. Use
1155 multiple times for multiple URLs.
1157 The URL(s) should be added to the trustfile as well, so users don't end up
1158 locked out from the information on why they were locked out in the first
1162 -------------------------------------------------------------------------------
1163 7.2.3. admin-address
1166 An email address to reach the proxy administrator.
1175 No email address is displayed on error pages and the CGI user interface.
1178 If both admin-address and proxy-info-url are unset, the whole "Local
1179 Privoxy Support" box on all generated pages will not be shown.
1182 -------------------------------------------------------------------------------
1183 7.2.4. proxy-info-url
1186 A URL to documentation about the local Privoxy setup, configuration or
1196 No link to local documentation is displayed on error pages and the CGI user
1200 If both admin-address and proxy-info-url are unset, the whole "Local
1201 Privoxy Support" box on all generated pages will not be shown.
1203 This URL shouldn't be blocked ;-)
1206 -------------------------------------------------------------------------------
1209 These options are mainly useful when tracing a problem. Note that you might
1210 also want to invoke Privoxy with the --no-daemon command line option when
1212 -------------------------------------------------------------------------------
1217 Key values that determine what information gets logged to the logfile.
1223 12289 (i.e.: URLs plus informational and warning messages)
1226 Nothing gets logged.
1229 The available debug levels are:
1231 debug 1 # show each GET/POST/CONNECT request
1232 debug 2 # show each connection status
1233 debug 4 # show I/O status
1234 debug 8 # show header parsing
1235 debug 16 # log all data into the logfile
1236 debug 32 # debug force feature
1237 debug 64 # debug regular expression filter
1238 debug 128 # debug fast redirects
1239 debug 256 # debug GIF de-animation
1240 debug 512 # Common Log Format
1241 debug 1024 # debug kill pop-ups
1242 debug 4096 # Startup banner and warnings.
1243 debug 8192 # Non-fatal errors
1245 To select multiple debug levels, you can either add them or use multiple
1248 A debug level of 1 is informative because it will show you each request as
1249 it happens. 1, 4096 and 8192 are highly recommended so that you will notice
1250 when things go wrong. The other levels are probably only of interest if you
1251 are hunting down a specific problem. They can produce a hell of an output
1254 The reporting of fatal errors (i.e. ones which crash Privoxy) is always on
1255 and cannot be disabled.
1257 If you want to use CLF (Common Log Format), you should set "debug 512" ONLY
1258 and not enable anything else.
1261 -------------------------------------------------------------------------------
1262 7.3.2. single-threaded
1265 Whether to run only one server thread
1274 Multi-threaded (or, where unavailable: forked) operation, i.e. the ability
1275 to serve multiple requests simultaneously.
1278 This option is only there for debug purposes and you should never need to
1279 use it. It will drastically reduce performance.
1282 -------------------------------------------------------------------------------
1283 7.4. Access Control and Security
1285 This section of the config file controls the security-relevant aspects of
1286 Privoxy's configuration.
1287 -------------------------------------------------------------------------------
1289 7.4.1. listen-address
1292 The IP address and TCP port on which Privoxy will listen for client
1302 Bind to 127.0.0.1 (localhost), port 8118. This is suitable and recommended
1303 for home users who run Privoxy on the same machine as their browser.
1306 You will need to configure your browser(s) to this proxy address and port.
1308 If you already have another service running on port 8118, or if you want to
1309 serve requests from other machines (e.g. on your local network) as well,
1310 you will need to override the default.
1312 If you leave out the IP address, Privoxy will bind to all interfaces
1313 (addresses) on your machine and may become reachable from the Internet. In
1314 that case, consider using access control lists (ACL's, see below), and/or a
1317 If you open Privoxy to untrusted users, you will also want to turn off the
1318 enable-edit-actions and enable-remote-toggle options!
1321 Suppose you are running Privoxy on a machine which has the address
1322 192.168.0.1 on your local private network (192.168.0.0) and has another
1323 outside connection with a different address. You want it to serve requests
1326 listen-address 192.168.0.1:8118
1329 -------------------------------------------------------------------------------
1333 Initial state of "toggle" status
1342 Act as if toggled on
1345 If set to 0, Privoxy will start in "toggled off" mode, i.e. behave like a
1346 normal, content-neutral proxy where all ad blocking, filtering, etc are
1347 disabled. See enable-remote-toggle below. This is not really useful
1348 anymore, since toggling is much easier via the web interface than via
1349 editing the conf file.
1351 The windows version will only display the toggle icon in the system tray if
1352 this option is present.
1355 -------------------------------------------------------------------------------
1356 7.4.3. enable-remote-toggle
1359 Whether or not the web-based toggle feature may be used
1368 The web-based toggle feature is disabled.
1371 When toggled off, Privoxy acts like a normal, content-neutral proxy, i.e.
1372 it acts as if none of the actions applied to any URL.
1374 For the time being, access to the toggle feature can not be controlled
1375 separately by "ACLs" or HTTP authentication, so that everybody who can
1376 access Privoxy (see "ACLs" and listen-address above) can toggle it for all
1377 users. So this option is not recommended for multi-user environments with
1380 Note that you must have compiled Privoxy with support for this feature,
1381 otherwise this option has no effect.
1384 -------------------------------------------------------------------------------
1385 7.4.4. enable-edit-actions
1388 Whether or not the web-based actions file editor may be used
1397 The web-based actions file editor is disabled.
1400 For the time being, access to the editor can not be controlled separately
1401 by "ACLs" or HTTP authentication, so that everybody who can access Privoxy
1402 (see "ACLs" and listen-address above) can modify its configuration for all
1403 users. So this option is not recommended for multi-user environments with
1406 Note that you must have compiled Privoxy with support for this feature,
1407 otherwise this option has no effect.
1410 -------------------------------------------------------------------------------
1411 7.4.5. ACLs: permit-access and deny-access
1414 Who can access what.
1417 src_addr[/src_masklen] [dst_addr[/dst_masklen]]
1419 Where src_addr and dst_addr are IP addresses in dotted decimal notation or
1420 valid DNS names, and src_masklen and dst_masklen are subnet masks in CIDR
1421 notation, i.e. integer values from 2 to 30 representing the length (in
1422 bits) of the network address. The masks and the whole destination part are
1429 Don't restrict access further than implied by listen-address
1432 Access controls are included at the request of ISPs and systems
1433 administrators, and are not usually needed by individual users. For a
1434 typical home user, it will normally suffice to ensure that Privoxy only
1435 listens on the localhost (127.0.0.1) or internal (home) network address by
1436 means of the listen-address option.
1438 Please see the warnings in the FAQ that this proxy is not intended to be a
1439 substitute for a firewall or to encourage anyone to defer addressing basic
1440 security weaknesses.
1442 Multiple ACL lines are OK. If any ACLs are specified, then the Privoxy
1443 talks only to IP addresses that match at least one permit-access line and
1444 don't match any subsequent deny-access line. In other words, the last match
1445 wins, with the default being deny-access.
1447 If Privoxy is using a forwarder (see forward below) for a particular
1448 destination URL, the dst_addr that is examined is the address of the
1449 forwarder and NOT the address of the ultimate target. This is necessary
1450 because it may be impossible for the local Privoxy to determine the IP
1451 address of the ultimate target (that's often what gateways are used for).
1453 You should prefer using IP addresses over DNS names, because the address
1454 lookups take time. All DNS names must resolve! You can not use domain
1455 patterns like "*.org" or partial domain names. If a DNS name resolves to
1456 multiple IP addresses, only the first one is used.
1458 Denying access to particular sites by ACL may have undesired side effects
1459 if the site in question is hosted on a machine which also hosts other
1463 Explicitly define the default behavior if no ACL and listen-address are
1464 set: "localhost" is OK. The absence of a dst_addr implies that all
1465 destination addresses are OK:
1467 permit-access localhost
1469 Allow any host on the same class C subnet as www.privoxy.org access to
1470 nothing but www.example.com:
1472 permit-access www.privoxy.org/24 www.example.com/32
1474 Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere,
1475 with the exception that 192.168.45.73 may not access
1476 www.dirty-stuff.example.com:
1478 permit-access 192.168.45.64/26
1479 deny-access 192.168.45.73 www.dirty-stuff.example.com
1482 -------------------------------------------------------------------------------
1486 Maximum size of the buffer for content filtering.
1495 Use a 4MB (4096 KB) limit.
1498 For content filtering, i.e. the +filter and +deanimate-gif actions, it is
1499 necessary that Privoxy buffers the entire document body. This can be
1500 potentially dangerous, since a server could just keep sending data
1501 indefinitely and wait for your RAM to exhaust -- with nasty consequences.
1504 When a document buffer size reaches the buffer-limit, it is flushed to the
1505 client unfiltered and no further attempt to filter the rest of the document
1506 is made. Remember that there may be multiple threads running, which might
1507 require up to buffer-limit Kbytes each, unless you have enabled
1508 "single-threaded" above.
1511 -------------------------------------------------------------------------------
1514 This feature allows routing of HTTP requests through a chain of multiple
1515 proxies. It can be used to better protect privacy and confidentiality when
1516 accessing specific domains by routing requests to those domains through an
1517 anonymous public proxy (see e.g. http://www.multiproxy.org/anon_list.htm) Or to
1518 use a caching proxy to speed up browsing. Or chaining to a parent proxy may be
1519 necessary because the machine that Privoxy runs on has no direct Internet
1522 Also specified here are SOCKS proxies. Privoxy supports the SOCKS 4 and SOCKS
1524 -------------------------------------------------------------------------------
1529 To which parent HTTP proxy specific requests should be routed.
1532 target_domain[:port] http_parent[/port]
1534 Where target_domain is a domain name pattern (see the chapter on domain
1535 matching in the default.action file), http_parent is the address of the
1536 parent HTTP proxy as an IP addresses in dotted decimal notation or as a
1537 valid DNS name (or "." to denote "no forwarding", and the optional port
1538 parameters are TCP ports, i.e. integer values from 1 to 64535
1544 Don't use parent HTTP proxies.
1547 If http_parent is ".", then requests are not forwarded to another HTTP
1548 proxy but are made directly to the web servers.
1550 Multiple lines are OK, they are checked in sequence, and the last match
1554 Everything goes to an example anonymizing proxy, except SSL on port 443
1555 (which it doesn't handle):
1557 forward .* anon-proxy.example.org:8080
1560 Everything goes to our example ISP's caching proxy, except for requests to
1563 forward .*. caching-proxy.example-isp.net:8000
1564 forward .example-isp.net .
1567 -------------------------------------------------------------------------------
1568 7.5.2. forward-socks4 and forward-socks4a
1571 Through which SOCKS proxy (and to which parent HTTP proxy) specific
1572 requests should be routed.
1575 target_domain[:port] socks_proxy[/port] http_parent[/port]
1577 Where target_domain is a domain name pattern (see the chapter on domain
1578 matching in the default.action file), http_parent and socks_proxy are IP
1579 addresses in dotted decimal notation or valid DNS names (http_parent may be
1580 "." to denote "no HTTP forwarding"), and the optional port parameters are
1581 TCP ports, i.e. integer values from 1 to 64535
1587 Don't use SOCKS proxies.
1590 Multiple lines are OK, they are checked in sequence, and the last match
1593 The difference between forward-socks4 and forward-socks4a is that in the
1594 SOCKS 4A protocol, the DNS resolution of the target hostname happens on the
1595 SOCKS server, while in SOCKS 4 it happens locally.
1597 If http_parent is ".", then requests are not forwarded to another HTTP
1598 proxy but are made (HTTP-wise) directly to the web servers, albeit through
1602 From the company example.com, direct connections are made to all "internal"
1603 domains, but everything outbound goes through their ISP's proxy by way of
1604 example.com's corporate SOCKS 4A gateway to the Internet.
1606 forward-socks4a .*. socks-gw.example.com:1080 www-cache.example-isp.net:8080
1607 forward .example.com .
1609 A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent
1612 forward-socks4 .*. socks-gw.example.com:1080 .
1615 -------------------------------------------------------------------------------
1616 7.5.3. Advanced Forwarding Examples
1618 If you have links to multiple ISPs that provide various special content only to
1619 their subscribers, you can configure multiple Privoxies which have connections
1620 to the respective ISPs to act as forwarders to each other, so that your users
1621 can see the internal content of all ISPs.
1623 Assume that host-a has a PPP connection to isp-a.net. And host-b has a PPP
1624 connection to isp-b.net. Both run Privoxy. Their forwarding configuration can
1630 forward .isp-b.net host-b:8118
1635 forward .isp-a.net host-a:8118
1637 Now, your users can set their browser's proxy to use either host-a or host-b
1638 and be able to browse the internal content of both isp-a and isp-b.
1640 If you intend to chain Privoxy and squid locally, then chain as browser ->
1641 squid -> privoxy is the recommended way.
1643 Assuming that Privoxy and squid run on the same box, your squid configuration
1644 could then look like this:
1646 # Define Privoxy as parent proxy (without ICP)
1647 cache_peer 127.0.0.1 parent 8118 7 no-query
1649 # Define ACL for protocol FTP
1652 # Do not forward FTP requests to Privoxy
1653 always_direct allow ftp
1655 # Forward all the rest to Privoxy
1656 never_direct allow all
1658 You would then need to change your browser's proxy settings to squid's address
1659 and port. Squid normally uses port 3128. If unsure consult http_port in
1661 -------------------------------------------------------------------------------
1663 7.6. Windows GUI Options
1665 Privoxy has a number of options specific to the Windows GUI interface:
1668 If "activity-animation" is set to 1, the Privoxy icon will animate when
1669 "Privoxy" is active. To turn off, set to 0.
1671 activity-animation 1
1675 If "log-messages" is set to 1, Privoxy will log messages to the console window:
1681 If "log-buffer-size" is set to 1, the size of the log buffer, i.e. the amount
1682 of memory used for the log messages displayed in the console window, will be
1683 limited to "log-max-lines" (see below).
1685 Warning: Setting this to 0 will result in the buffer to grow infinitely and eat
1692 log-max-lines is the maximum number of lines held in the log buffer. See above.
1698 If "log-highlight-messages" is set to 1, Privoxy will highlight portions of the
1699 log messages with a bold-faced font:
1701 log-highlight-messages 1
1705 The font used in the console window:
1707 log-font-name Comic Sans MS
1711 Font size used in the console window:
1717 "show-on-task-bar" controls whether or not Privoxy will appear as a button on
1718 the Task bar when minimized:
1724 If "close-button-minimizes" is set to 1, the Windows close button will minimize
1725 Privoxy instead of closing the program (close with the exit option on the File
1728 close-button-minimizes 1
1732 The "hide-console" option is specific to the MS-Win console version of Privoxy.
1733 If this option is used, Privoxy will disconnect from and hide the command
1738 -------------------------------------------------------------------------------
1742 The actions files are used to define what actions Privoxy takes for which URLs,
1743 and thus determine how ad images, cookies and various other aspects of HTTP
1744 content and transactions are handled, and on which sites (or even parts
1745 thereof). There are three such files included with Privoxy (as of version
1746 2.9.15), with differing purposes:
1748 * default.action - is the primary action file that sets the initial values
1749 for all actions. It is intended to provide a base level of functionality
1750 for Privoxy's array of features. So it is a set of broad rules that should
1751 work reasonably well for users everywhere. This is the file that the
1752 developers are keeping updated, and making available to users.
1754 * user.action - is intended to be for local site preferences and exceptions.
1755 As an example, if your ISP or your bank has specific requirements, and need
1756 special handling, this kind of thing should go here. This file will not be
1759 * standard.action - is used by the web based editor, to set various
1760 pre-defined sets of rules for the default actions section in
1761 default.action. These have increasing levels of aggressiveness and have no
1762 influence on your browsing unless you select them explicitly in the editor.
1763 It is not recommend to edit this file.
1766 The list of actions files to be used are defined in the main configuration
1767 file, and are processed in the order they are defined. The content of these can
1768 all be viewed and edited from http://config.privoxy.org/show-status.
1770 An actions file typically has multiple sections. If you want to use "aliases"
1771 in an actions file, you have to place the (optional) alias section at the top
1772 of that file. Then comes the default set of rules which will apply universally
1773 to all sites and pages (be very careful with using such a universal set in
1774 user.action or any other actions file after default.action, because it will
1775 override the result from consulting any previous file). And then below that,
1776 exceptions to the defined universal policies. You can regard user.action as an
1777 appendix to default.action, with the advantage that is a separate file, which
1778 makes preserving your personal settings across Privoxy upgrades easier.
1780 Actions can be used to block anything you want, including ads, banners, or just
1781 some obnoxious URL that you would rather not see. Cookies can be accepted or
1782 rejected, or accepted only during the current browser session (i.e. not written
1783 to disk), content can be modified, JavaScripts tamed, user-tracking fooled, and
1784 much more. See below for a complete list of actions.
1785 -------------------------------------------------------------------------------
1787 8.1. Finding the Right Mix
1789 Note that some actions, like cookie suppression or script disabling, may render
1790 some sites unusable that rely on these techniques to work properly. Finding the
1791 right mix of actions is not always easy and certainly a matter of personal
1792 taste. In general, it can be said that the more "aggressive" your default
1793 settings (in the top section of the actions file) are, the more exceptions for
1794 "trusted" sites you will have to make later. If, for example, you want to kill
1795 popup windows per default, you'll have to make exceptions from that rule for
1796 sites that you regularly use and that require popups for actually useful
1797 content, like maybe your bank, favorite shop, or newspaper.
1799 We have tried to provide you with reasonable rules to start from in the
1800 distribution actions files. But there is no general rule of thumb on these
1801 things. There just are too many variables, and sites are constantly changing.
1802 Sooner or later you will want to change the rules (and read this chapter again
1804 -------------------------------------------------------------------------------
1808 The easiest way to edit the actions files is with a browser by using our
1809 browser-based editor, which can be reached from http://config.privoxy.org/
1810 show-status. The editor allows both fine-grained control over every single
1811 feature on a per-URL basis, and easy choosing from wholesale sets of defaults
1812 like "Cautious", "Medium" or "Advanced".
1814 If you prefer plain text editing to GUIs, you can of course also directly edit
1815 the the actions files. Look at default.action which is richly commented.
1816 -------------------------------------------------------------------------------
1818 8.3. How Actions are Applied to URLs
1820 Actions files are divided into sections. There are special sections, like the "
1821 alias" sections which will be discussed later. For now let's concentrate on
1822 regular sections: They have a heading line (often split up to multiple lines
1823 for readability) which consist of a list of actions, separated by whitespace
1824 and enclosed in curly braces. Below that, there is a list of URL patterns, each
1827 To determine which actions apply to a request, the URL of the request is
1828 compared to all patterns in each action file file. Every time it matches, the
1829 list of applicable actions for the URL is incrementally updated, using the
1830 heading of the section in which the pattern is located. If multiple matches for
1831 the same URL set the same action differently, the last match wins. If not, the
1832 effects are aggregated. E.g. a URL might match a regular section with a heading
1833 line of { +handle-as-image }, then later another one with just { +block },
1834 resulting in both actions to apply.
1836 You can trace this process for any given URL by visiting http://
1837 config.privoxy.org/show-url-info.
1839 More detail on this is provided in the Appendix, Anatomy of an Action.
1840 -------------------------------------------------------------------------------
1844 Generally, a pattern has the form <domain>/<path>, where both the <domain> and
1845 <path> are optional. (This is why the pattern / matches all URLs).
1848 is a domain-only pattern and will match any request to www.example.com,
1849 regardless of which document on that server is requested.
1852 means exactly the same. For domain-only patterns, the trailing / may be
1855 www.example.com/index.html
1856 matches only the single document /index.html on www.example.com.
1859 matches the document /index.html, regardless of the domain, i.e. on any web
1863 matches nothing, since it would be interpreted as a domain name and there
1864 is no top-level domain called .html.
1867 -------------------------------------------------------------------------------
1868 8.4.1. The Domain Pattern
1870 The matching of the domain part offers some flexible options: if the domain
1871 starts or ends with a dot, it becomes unanchored at that end. For example:
1874 matches any domain that ENDS in .example.com
1877 matches any domain that STARTS with www.
1880 matches any domain that CONTAINS .example. (Correctly speaking: It matches
1881 any FQDN that contains example as a domain.)
1884 Additionally, there are wild-cards that you can use in the domain names
1885 themselves. They work pretty similar to shell wild-cards: "*" stands for zero
1886 or more arbitrary characters, "?" stands for any single character, you can
1887 define character classes in square brackets and all of that can be freely
1891 matches "adserver.example.com", "ads.example.com", etc but not
1895 matches all of the above, and then some.
1898 matches www.ipix.com, pictures.epix.com, a.b.c.d.e.upix.com etc.
1900 www[1-9a-ez].example.c*
1901 matches www1.example.com, www4.example.cc, wwwd.example.cy,
1902 wwwz.example.com etc., but not wwww.example.com.
1905 -------------------------------------------------------------------------------
1906 8.4.2. The Path Pattern
1908 Privoxy uses Perl compatible regular expressions (through the PCRE library) for
1911 There is an Appendix with a brief quick-start into regular expressions, and
1912 full (very technical) documentation on PCRE regex syntax is available on-line
1913 at http://www.pcre.org/man.txt. You might also find the Perl man page on
1914 regular expressions (man perlre) useful, which is available on-line at http://
1915 www.perldoc.com/perl5.6/pod/perlre.html.
1917 Note that the path pattern is automatically left-anchored at the "/", i.e. it
1918 matches as if it would start with a "^" (regular expression speak for the
1919 beginning of a line).
1921 Please also note that matching in the path is CASE INSENSITIVE by default, but
1922 you can switch to case sensitive at any point in the pattern by using the "(?
1923 -i)" switch: www.example.com/(?-i)PaTtErN.* will match only documents whose
1924 path starts with PaTtErN in exactly this capitalization.
1925 -------------------------------------------------------------------------------
1929 All actions are disabled by default, until they are explicitly enabled
1930 somewhere in an actions file. Actions are turned on if preceded with a "+", and
1931 turned off if preceded with a "-". So a +action means "do that action", e.g.
1932 +block means "please block URLs that match the following patterns", and -block
1933 means "don't block URLs that match the following patterns, even if +block
1934 previously applied."
1936 Again, actions are invoked by placing them on a line, enclosed in curly braces
1937 and separated by whitespace, like in {+some-action -some-other-action
1938 {some-parameter}}, followed by a list of URL patterns, one per line, to which
1939 they apply. Together, the actions line and the following pattern lines make up
1940 a section of the actions file.
1942 There are three classes of actions:
1944 * Boolean, i.e the action can only be "enabled" or "disabled". Syntax:
1946 +name # enable action name
1947 -name # disable action name
1951 * Parameterized, where some value is required in order to enable this type of
1954 +name{param} # enable action and set parameter to param,
1955 # overwriting parameter from previous match if necessary
1956 -name # disable action. The parameter can be omitted
1958 Note that if the URL matches multiple positive forms of a parameterized
1959 action, the last match wins, i.e. the params from earlier matches are
1962 Example: +hide-user-agent{ Mozilla 1.0 }
1964 * Multi-value. These look exactly like parameterized actions, but they behave
1965 differently: If the action applies multiple times to the same URL, but with
1966 different parameters, all the parameters from all matches are remembered.
1967 This is used for actions that can be executed for the same request
1968 repeatedly, like adding multiple headers, or filtering through multiple
1971 +name{param} # enable action and add param to the list of parameters
1972 -name{param} # remove the parameter param from the list of parameters
1973 # If it was the last one left, disable the action.
1974 -name # disable this action completely and remove all parameters from the list
1976 Examples: +add-header{X-Fun-Header: Some text} and +filter{html-annoyances}
1979 If nothing is specified in any actions file, no "actions" are taken. So in this
1980 case Privoxy would just be a normal, non-blocking, non-anonymizing proxy. You
1981 must specifically enable the privacy and blocking features you need (although
1982 the provided default actions files will give a good starting point).
1984 Later defined actions always over-ride earlier ones. So exceptions to any rules
1985 you make, should come in the latter part of the file (or in a file that is
1986 processed later when using multiple actions files). For multi-valued actions,
1987 the actions are applied in the order they are specified. Actions files are
1988 processed in the order they are defined in config (the default installation has
1989 three actions files). It also quite possible for any given URL pattern to match
1990 more than one pattern and thus more than one set of actions!
1992 The list of valid Privoxy actions are:
1993 -------------------------------------------------------------------------------
1998 Confuse log analysis, custom applications
2001 Sends a user defined HTTP header to the web server.
2007 Any string value is possible. Validity of the defined HTTP headers is not
2008 checked. It is recommended that you use the "X-" prefix for custom headers.
2011 This action may be specified multiple times, in order to define multiple
2012 headers. This is rarely needed for the typical user. If you don't know what
2013 "HTTP headers" are, you definitely don't need to worry about this one.
2016 +add-header{X-User-Tracking: sucks}
2019 -------------------------------------------------------------------------------
2023 Block ads or other obnoxious content
2026 Requests for URLs to which this action applies are blocked, i.e. the
2027 requests are not forwarded to the remote server, but answered locally with
2028 a substitute page or image, as determined by the handle-as-image and
2029 set-image-blocker actions.
2038 Privoxy sends a special "BLOCKED" page for requests to blocked pages. This
2039 page contains links to find out why the request was blocked, and a
2040 click-through to the blocked content (the latter only if compiled with the
2041 force feature enabled). The "BLOCKED" page adapts to the available screen
2042 space -- it displays full-blown if space allows, or miniaturized and
2043 text-only if loaded into a small frame or window. If you are using Privoxy
2044 right now, you can take a look at the "BLOCKED" page.
2046 A very important exception occurs if both block and handle-as-image, apply
2047 to the same request: it will then be replaced by an image. If
2048 set-image-blocker (see below) also applies, the type of image will be
2049 determined by its parameter, if not, the standard checkerboard pattern is
2052 It is important to understand this process, in order to understand how
2053 Privoxy deals with ads and other unwanted content.
2055 The filter action can perform a very similar task, by "blocking" banner
2056 images and other content through rewriting the relevant URLs in the
2057 document's HTML source, so they don't get requested in the first place.
2058 Note that this is a totally different technique, and it's easy to confuse
2061 Example usage (section):
2062 {+block} # Block and replace with "blocked" page
2063 .nasty-stuff.example.com
2065 {+block +handle-as-image} # Block and replace with image
2070 -------------------------------------------------------------------------------
2071 8.5.3. crunch-incoming-cookies
2074 Prevent the web server from setting any cookies on your system
2077 Deletes any "Set-Cookie:" HTTP headers from server replies.
2086 This action is only concerned with incoming cookies. For outgoing cookies,
2087 use crunch-outgoing-cookies. Use both to disable cookies completely.
2089 It makes no sense at all to use this action in conjunction with the
2090 session-cookies-only action, since it would prevent the session cookies
2094 +crunch-incoming-cookies
2097 -------------------------------------------------------------------------------
2098 8.5.4. crunch-outgoing-cookies
2101 Prevent the web server from reading any cookies from your system
2104 Deletes any "Cookie:" HTTP headers from client requests.
2113 This action is only concerned with outgoing cookies. For incoming cookies,
2114 use crunch-incoming-cookies. Use both to disable cookies completely.
2116 It makes no sense at all to use this action in conjunction with the
2117 session-cookies-only action, since it would prevent the session cookies
2121 +crunch-outgoing-cookies
2124 -------------------------------------------------------------------------------
2125 8.5.5. deanimate-gifs
2128 Stop those annoying, distracting animated GIF images.
2131 De-animate GIF animations, i.e. reduce them to their first or last image.
2140 This will also shrink the images considerably (in bytes, not pixels!). If
2141 the option "first" is given, the first frame of the animation is used as
2142 the replacement. If "last" is given, the last frame of the animation is
2143 used instead, which probably makes more sense for most banner animations,
2144 but also has the risk of not showing the entire last frame (if it is only a
2145 delta to an earlier frame).
2147 You can safely use this action with patterns that will also match non-GIF
2148 objects, because no attempt will be made at anything that doesn't look like
2152 +deanimate-gifs{last}
2155 -------------------------------------------------------------------------------
2156 8.5.6. downgrade-http-version
2159 Work around (very rare) problems with HTTP/1.1
2162 Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0.
2171 This is a left-over from the time when Privoxy didn't support important
2172 HTTP/1.1 features well. It is left here for the unlikely case that you
2173 experience HTTP/1.1 related problems with some server out there. Not all
2174 (optional) HTTP/1.1 features are supported yet, so there is a chance you
2175 might need this action.
2177 Example usage (section):
2178 {+downgrade-http-version}
2179 problem-host.example.com
2182 -------------------------------------------------------------------------------
2183 8.5.7. fast-redirects
2186 Fool some click-tracking scripts and speed up indirect links
2189 Cut off all but the last valid URL from requests.
2198 Many sites, like yahoo.com, don't just link to other sites. Instead, they
2199 will link to some script on their own servers, giving the destination as a
2200 parameter, which will then redirect you to the final target. URLs resulting
2201 from this scheme typically look like: http://some.place/click-tracker.cgi?
2202 target=http://some.where.else.
2204 Sometimes, there are even multiple consecutive redirects encoded in the
2205 URL. These redirections via scripts make your web browsing more traceable,
2206 since the server from which you follow such a link can see where you go to.
2207 Apart from that, valuable bandwidth and time is wasted, while your browser
2208 ask the server for one redirect after the other. Plus, it feeds the
2211 This feature is currently not very smart and is scheduled for improvement.
2212 It is likely to break some sites. You should expect to need possibly many
2213 exceptions to this action, if it is enabled by default in default.action.
2214 Some sites just don't work without it.
2220 -------------------------------------------------------------------------------
2224 Get rid of HTML and JavaScript annoyances, banner advertisements (by size),
2225 do fun text replacements, etc.
2228 Text documents, including HTML and JavaScript, to which this action
2229 applies, are filtered on-the-fly through the specified regular expression
2230 based substitutions.
2236 The name of a filter, as defined in the filter file (typically
2237 default.filter, set by the filterfile option in the config file). Filtering
2238 can be completely disabled without the use of parameters.
2241 For your convenience, there are a number of pre-defined filters available
2242 in the distribution filter file that you can use. See the examples below
2245 This is potentially a very powerful feature! But "rolling your own" filters
2246 requires a knowledge of regular expressions and HTML.
2248 Filtering requires buffering the page content, which may appear to slow
2249 down page rendering since nothing is displayed until all content has passed
2250 the filters. (It does not really take longer, but seems that way since the
2251 page is not incrementally displayed.) This effect will be more noticeable
2252 on slower connections.
2254 The amount of data that can be filtered is limited to the buffer-limit
2255 option in the main config file. The default is 4096 KB (4 Megs). Once this
2256 limit is exceeded, the buffered data, and all pending data, is passed
2257 through unfiltered. Inappropriate MIME types are not filtered.
2259 At this time, Privoxy cannot (yet!) uncompress compressed documents. If you
2260 want filtering to work on all documents, even those that would normally be
2261 sent compressed, use the prevent-compression action in conjunction with
2264 Filtering can achieve some of the same effects as the block action, i.e. it
2265 can be used to block ads and banners. But the mechanism works quite
2266 differently. One effective use, is to block ad banners based on their size
2267 (see below), since many of these seem to be somewhat standardized.
2269 Feedback with suggestions for new or improved filters is particularly
2272 Example usage (with filters from the distribution default.filter file):
2273 +filter{html-annoyances} # Get rid of particularly annoying HTML abuse.
2275 +filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse
2277 +filter{banners-by-size} # Kill banners based on their size for this page (very efficient!)
2279 +filter{banners-by-link} # Kill banners based on the link they are contained in (experimental)
2281 +filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective
2283 +filter{content-cookies} # Kill cookies that come sneaking in the HTML or JS content
2285 +filter{popups} # Kill all popups in JS and HTML
2287 +filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking)
2289 +filter{fun} # Text replacements for subversive browsing fun!
2291 +filter{frameset-borders} # Give frames a border and make them resizeable
2293 +filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups)
2295 +filter{nimda} # Remove Nimda (virus) code.
2297 +filter{shockwave-flash} # Kill embedded Shockwave Flash objects
2299 +filter{crude-parental} # Kill all web pages that contain the words "sex" or "warez"
2301 +filter{js-events} # Kill all JS event bindings (Radically destructive! Only for extra nasty sites)
2304 -------------------------------------------------------------------------------
2305 8.5.9. handle-as-image
2308 Mark URLs as belonging to images (so they'll be replaced by images if they
2312 This action alone doesn't do anything noticeable. It just marks URLs as
2313 images. If the block action also applies, the presence or absence of this
2314 mark decides whether an HTML "blocked" page, or a replacement image (as
2315 determined by the set-image-blocker action) will be sent to the client as a
2316 substitute for the blocked content.
2325 The below generic example section is actually part of default.action. It
2326 marks all URLs with well-known image file name extensions as images and
2327 should be left intact.
2329 Users will probably only want to use the handle-as-image action in
2330 conjunction with block, to block sources of banners, whose URLs don't
2331 reflect the file type, like in the second example section.
2333 Note that you cannot treat HTML pages as images in most cases. For
2334 instance, (in-line) ad frames require an HTML page to be sent, or they
2335 won't display properly. Forcing handle-as-image in this situation will not
2336 replace the ad frame with an image, but lead to error messages.
2338 Example usage (sections):
2339 # Generic image extensions:
2342 /.*\.(gif|jpg|jpeg|png|bmp|ico)$
2344 # These don't look like images, but they're banners and should be
2345 # blocked as images:
2347 {+block +handle-as-image}
2348 some.nasty-banner-server.com/junk.cgi?output=trash
2350 # Banner source! Who cares if they also have non-image content?
2354 -------------------------------------------------------------------------------
2355 8.5.10. hide-forwarded-for-headers
2358 Improve privacy by hiding the true source of the request
2361 Deletes any existing "X-Forwarded-for:" HTTP header from client requests,
2362 and prevents adding a new one.
2371 It is fairly safe to leave this on.
2373 This action is scheduled for improvement: It should be able to generate
2374 forged "X-Forwarded-for:" headers using random IP addresses from a
2375 specified network, to make successive requests from the same client look
2376 like requests from a pool of different users sharing the same proxy.
2379 +hide-forwarded-for-headers
2382 -------------------------------------------------------------------------------
2383 8.5.11. hide-from-header
2386 Keep your (old and ill) browser from telling web servers your email address
2389 Deletes any existing "From:" HTTP header, or replaces it with the specified
2396 Keyword: "block", or any user defined value.
2399 The keyword "block" will completely remove the header (not to be confused
2400 with the block action).
2402 Alternately, you can specify any value you prefer to be sent to the web
2403 server. If you do, it is a matter of fairness not to use any address that
2404 is actually used by a real person.
2406 This action is rarely needed, as modern web browsers don't send "From:"
2410 +hide-from-header{block}
2412 +hide-from-header{spam-me-senseless@sittingduck.example.com}
2415 -------------------------------------------------------------------------------
2416 8.5.12. hide-referrer
2419 Conceal which link you followed to get to a particular site
2422 Deletes the "Referer:" (sic) HTTP header from the client request, or
2423 replaces it with a forged one.
2429 + "block" to delete the header completely.
2431 + "forge" to pretend to be coming from the homepage of the server we are
2434 + Any other string to set a user defined referrer.
2438 "forge" is the preferred option here, since some servers will not send
2439 images back otherwise, in an attempt to prevent their valuable content from
2440 being embedded elsewhere (and hence, without being surrounded by their
2443 hide-referer is an alternate spelling of hide-referrer and the two can be
2444 can be freely substituted with each other. ("referrer" is the correct
2445 English spelling, however the HTTP specification has a bug - it requires it
2446 to be spelled as "referer".)
2449 +hide-referrer{forge}
2451 +hide-referrer{http://www.yahoo.com/}
2454 -------------------------------------------------------------------------------
2455 8.5.13. hide-user-agent
2458 Conceal your type of browser and client operating system
2461 Replaces the value of the "User-Agent:" HTTP header in client requests with
2462 the specified value.
2468 Any user-defined string.
2471 +-----------------------------------------------------------------+
2473 +-----------------------------------------------------------------+
2474 |This breaks many web sites that depend on looking at this header |
2475 |in order to customize their content for different browsers |
2476 |(which, by the way, is NOT a smart way to do that!). |
2477 +-----------------------------------------------------------------+
2479 Using this action in multi-user setups or wherever different types of
2480 browsers will access the same Privoxy is not recommended. In single-user,
2481 single-browser setups, you might use it to delete your OS version
2482 information from the headers, because it is an invitation to exploit known
2483 bugs for your OS. It is also occasionally useful to forge this in order to
2484 access sites that won't let you in otherwise (though there may be a good
2485 reason in some cases). Example of this: some MSN sites will not let Mozilla
2486 enter, yet forging to a Netscape 6.1 user-agent works just fine. (Must be
2487 just a silly MS goof, I'm sure :-).
2489 This action is scheduled for improvement.
2492 +hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}
2495 -------------------------------------------------------------------------------
2499 Eliminate those annoying pop-up windows
2502 While loading the document, replace JavaScript code that opens pop-up
2503 windows with (syntactically neutral) dummy code on the fly.
2512 This action is easily confused with the built-in, hardwired filter action,
2513 but there are important differences: For kill-popups, the document need not
2514 be buffered, so it can be incrementally rendered while downloading. But
2515 kill-popups doesn't catch as many pop-ups as filter{popups} does.
2517 Think of it as a fast and efficient replacement for a filter that you can
2518 use if you don't want any filtering at all. Note that it doesn't make sense
2519 to combine it with any filter action, since as soon as one filter applies,
2520 the whole document needs to be buffered anyway, which destroys the
2521 advantage of the kill-popups action over its filter equivalent.
2523 Killing all pop-ups is a dangerous business. Many shops and banks rely on
2524 pop-ups to display forms, shopping carts etc, and killing only the unwanted
2525 pop-ups would require artificial intelligence in Privoxy. If the only kind
2526 of pop-ups that you want to kill are exit consoles (those really nasty
2527 windows that appear when you close an other one), you might want to use
2528 filter{js-annoyances} instead.
2534 -------------------------------------------------------------------------------
2535 8.5.15. limit-connect
2538 Prevent abuse of Privoxy as a TCP proxy relay
2541 Specifies to which ports HTTP CONNECT requests are allowable.
2547 A comma-separated list of ports or port ranges (the latter using dashes,
2548 with the minimum defaulting to 0 and the maximum to 65K).
2551 By default, i.e. if no limit-connect action applies, Privoxy only allows
2552 HTTP CONNECT requests to port 443 (the standard, secure HTTPS port). Use
2553 limit-connect if more fine-grained control is desired for some or all
2556 The CONNECT methods exists in HTTP to allow access to secure websites (
2557 "https://" URLs) through proxies. It works very simply: the proxy connects
2558 to the server on the specified port, and then short-circuits its
2559 connections to the client and to the remote server. This can be a big
2560 security hole, since CONNECT-enabled proxies can be abused as TCP relays
2563 If you don't know what any of this means, there probably is no reason to
2564 change this one, since the default is already very restrictive.
2567 +limit-connect{443} # This is the default and need not be specified.
2568 +limit-connect{80,443} # Ports 80 and 443 are OK.
2569 +limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
2570 +limit-connect{-} # All ports are OK (gaping security hole!)
2573 -------------------------------------------------------------------------------
2574 8.5.16. prevent-compression
2577 Ensure that servers send the content uncompressed, so it can be passed
2581 Adds a header to the request that asks for uncompressed transfer.
2590 More and more websites send their content compressed by default, which is
2591 generally a good idea and saves bandwidth. But for the filter,
2592 deanimate-gifs and kill-popups actions to work, Privoxy needs access to the
2593 uncompressed data. Unfortunately, Privoxy can't yet(!) uncompress, filter,
2594 and re-compress the content on the fly. So if you want to ensure that all
2595 websites, including those that normally compress, can be filtered, you need
2598 This will slow down transfers from those websites, though. If you use any
2599 of the above-mentioned actions, you will typically want to use
2600 prevent-compression in conjunction with them.
2602 Note that some (rare) ill-configured sites don't handle requests for
2603 uncompressed documents correctly (they send an empty document body). If you
2604 use prevent-compression per default, you'll have to add exceptions for
2605 those sites. See the example for how to do that.
2607 Example usage (sections):
2610 {+prevent-compression}
2613 # Make exceptions for ill sites:
2615 {-prevent-compression}
2617 www.pclinuxonline.com
2620 -------------------------------------------------------------------------------
2621 8.5.17. send-vanilla-wafer
2624 Feed log analysis scripts with useless data.
2627 Sends a cookie with each request stating that you do not accept any
2628 copyright on cookies sent to you, and asking the site operator not to track
2638 The vanilla wafer is a (relatively) unique header and could conceivably be
2641 This action is rarely used and not enabled in the default configuration.
2647 -------------------------------------------------------------------------------
2651 Send custom cookies or feed log analysis scripts with even more useless
2655 Sends a custom, user-defined cookie with each request.
2661 A string of the form "name=value".
2664 Being multi-valued, multiple instances of this action can apply to the same
2665 request, resulting in multiple cookies being sent.
2667 This action is rarely used and not enabled in the default configuration.
2669 Example usage (section):
2670 {+send-wafer{UsingPrivoxy=true}}
2671 my-internal-testing-server.void
2674 -------------------------------------------------------------------------------
2675 8.5.19. session-cookies-only
2678 Allow only temporary "session" cookies (for the current browser session
2682 Deletes the "expires" field from "Set-Cookie:" server headers. Most
2683 browsers will not store such cookies permanently and forget them in between
2693 This is less strict than crunch-incoming-cookies / crunch-outgoing-cookies
2694 and allows you to browse websites that insist or rely on setting cookies,
2695 without compromising your privacy too badly.
2697 Most browsers will not permanently store cookies that have been processed
2698 by session-cookies-only and will forget about them between sessions. This
2699 makes profiling cookies useless, but won't break sites which require
2700 cookies so that you can log in for transactions. This is generally turned
2701 on for all sites, and is the recommended setting.
2703 It makes no sense at all to use session-cookies-only together with
2704 crunch-incoming-cookies or crunch-outgoing-cookies. If you do, cookies will
2707 Note that it is up to the browser how it handles such cookies without an
2708 "expires" field. If you use an exotic browser, you might want to try it out
2712 +session-cookies-only
2715 -------------------------------------------------------------------------------
2716 8.5.20. set-image-blocker
2719 Choose the replacement for blocked images
2722 This action alone doesn't do anything noticeable. If both block and
2723 handle-as-image also apply, i.e. if the request is to be blocked as an
2724 image, then the parameter of this action decides what will be sent as a
2731 + "pattern" to send a built-in checkerboard pattern image. The image is
2732 visually decent, scales very well, and makes it obvious where banners
2735 + "blank" to send a built-in transparent image. This makes banners
2736 disappear completely, but makes it hard to detect where Privoxy has
2737 blocked images on a given page and complicates troubleshooting if
2738 Privoxy has blocked innocent images, like navigation icons.
2740 + "target-url" to send a redirect to target-url. You can redirect to any
2741 image anywhere, even in your local filesystem (via "file:///" URL).
2743 A good application of redirects is to use special Privoxy-built-in
2744 URLs, which send the built-in images, as target-url. This has the same
2745 visual effect as specifying "blank" or "pattern" in the first place,
2746 but enables your browser to cache the replacement image, instead of
2747 requesting it over and over again.
2751 The URLs for the built-in images are "http://config.privoxy.org/
2752 send-banner?type=type", where type is either "blank" or "pattern".
2754 There is a third (advanced) type, called "auto". It is NOT to be used in
2755 set-image-blocker, but meant for use from filters. Auto will select the
2756 type of image that would have applied to the referring page, had it been an
2762 +set-image-blocker{pattern}
2764 Redirect to the BSD devil:
2766 +set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}
2768 Redirect to the built-in pattern for better caching:
2770 +set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}
2773 -------------------------------------------------------------------------------
2776 Note that many of these actions have the potential to cause a page to
2777 misbehave, possibly even not to display at all. There are many ways a site
2778 designer may choose to design his site, and what HTTP header content, and other
2779 criteria, he may depend on. There is no way to have hard and fast rules for all
2780 sites. See the Appendix for a brief example on troubleshooting actions.
2781 -------------------------------------------------------------------------------
2785 Custom "actions", known to Privoxy as "aliases", can be defined by combining
2786 other actions. These can in turn be invoked just like the built-in actions.
2787 Currently, an alias name can contain any character except space, tab, "=", "{"
2788 and "}", but we strongly recommend that you only use "a" to "z", "0" to "9",
2789 "+", and "-". Alias names are not case sensitive, and are not required to start
2790 with a "+" or "-" sign, since they are merely textually expanded.
2792 Aliases can be used throughout the actions file, but they must be defined in a
2793 special section at the top of the file! And there can only be one such section
2794 per actions file. Each actions file may have its own alias section, and the
2795 aliases defined in it are only visible within that file.
2797 There are two main reasons to use aliases: One is to save typing for frequently
2798 used combinations of actions, the other one is a gain in flexibility: If you
2799 decide once how you want to handle shops by defining an alias called "shop",
2800 you can later change your policy on shops in one place, and your changes will
2801 take effect everywhere in the actions file where the "shop" alias is used.
2802 Calling aliases by their purpose also makes your actions files more readable.
2804 Currently, there is one big drawback to using aliases, though: Privoxy's
2805 built-in web-based action file editor honors aliases when reading the actions
2806 files, but it expands them before writing. So the effects of your aliases are
2807 of course preserved, but the aliases themselves are lost when you edit sections
2808 that use aliases with it. This is likely to change in future versions of
2811 Now let's define some aliases...
2813 # Useful custom aliases we can use later.
2815 # Note the (required!) section header line and that this section
2816 # must be at the top of the actions file!
2820 # These aliases just save typing later:
2821 # (Note that some already use other aliases!)
2823 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
2824 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
2825 block-as-image = +block +handle-as-image
2826 mercy-for-cookies = -crunch-all-cookies -session-cookies-only
2828 # These aliases define combinations of actions
2829 # that are useful for certain types of sites:
2831 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
2832 shop = -crunch-all-cookies -filter{popups} -kill-popups
2834 # Short names for other aliases, for really lazy people ;-)
2836 c0 = +crunch-all-cookies
2837 c1 = -crunch-all-cookies
2839 ...and put them to use. These sections would appear in the lower part of an
2840 actions file and define exceptions to the default actions (as specified further
2841 up for the "/" pattern):
2843 # These sites are either very complex or very keen on
2844 # user data and require minimal interference to work:
2847 .office.microsoft.com
2848 .windowsupdate.microsoft.com
2852 # Allow cookies (for setting and retrieving your customer data)
2856 .worldpay.com # for quietpc.com
2859 # These shops require pop-ups:
2861 {shop -kill-popups -filter{popups}}
2865 Aliases like "shop" and "fragile" are often used for "problem" sites that
2866 require some actions to be disabled in order to function properly.
2867 -------------------------------------------------------------------------------
2869 8.7. Actions Files Tutorial
2871 The above chapters have shown which actions files there are and how they are
2872 organized, how actions are specified and applied to URLs, how patterns work,
2873 and how to define and use aliases. Now, let's look at an example default.action
2874 and user.action file and see how all these pieces come together:
2875 -------------------------------------------------------------------------------
2877 8.7.1. default.action
2879 Every config file should start with a short comment stating its purpose:
2881 # Sample default.action file <developers@privoxy.org>
2883 Then, since this is the default.action file, the first section is a special
2884 section for internal use that you needn't change or worry about:
2886 ##########################################################################
2887 # Settings -- Don't change! For internal Privoxy use ONLY.
2888 ##########################################################################
2891 for-privoxy-version=3.0
2893 After that comes the (optional) alias section. We'll use the example section
2894 from the above chapter on aliases, that also explains why and how aliases are
2897 ##########################################################################
2899 ##########################################################################
2902 # These aliases just save typing later:
2903 # (Note that some already use other aliases!)
2905 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
2906 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
2907 block-as-image = +block +handle-as-image
2908 mercy-for-cookies = -crunch-all-cookies -session-cookies-only
2910 # These aliases define combinations of actions
2911 # that are useful for certain types of sites:
2913 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
2914 shop = mercy-for-cookies -filter{popups} -kill-popups
2916 Now come the regular sections, i.e. sets of actions, accompanied by URL
2917 patterns to which they apply. Remember all actions are disabled when matching
2918 starts, so we have to explicitly enable the ones we want.
2920 The first regular section is probably the most important. It has only one
2921 pattern, "/", but this pattern matches all URLs. Therefore, the set of actions
2922 used in this "default" section will be applied to all requests as a start. It
2923 can be partly or wholly overridden by later matches further down this file, or
2924 in user.action, but it will still be largely responsible for your overall
2925 browsing experience.
2927 Again, at the start of matching, all actions are disabled, so there is no real
2928 need to disable any actions here, but we will do that nonetheless, to have a
2929 complete listing for your reference. (Remember: a "+" preceding the action name
2930 enables the action, a "-" disables!). Also note how this long line has been
2931 made more readable by splitting it into multiple lines with line continuation.
2933 ##########################################################################
2934 # "Defaults" section:
2935 ##########################################################################
2939 -crunch-incoming-cookies \
2940 -crunch-outgoing-cookies \
2942 -downgrade-http-version \
2944 +filter{html-annoyances} \
2945 +filter{js-annoyances} \
2946 -filter{content-cookies} \
2949 -filter{refresh-tags} \
2952 +filter{banners-by-size} \
2953 -filter{banners-by-link} \
2954 -filter{img-reorder} \
2955 -filter{shockwave-flash} \
2956 -filter{crude-parental} \
2957 -filter{js-events} \
2959 +hide-forwarded-for-headers \
2960 +hide-from-header{block} \
2961 +hide-referrer{forge} \
2965 +prevent-compression \
2966 -send-vanilla-wafer \
2968 +session-cookies-only \
2969 +set-image-blocker{pattern} \
2971 / # forward slash will match *all* potential URL patterns.
2973 The default behavior is now set. Note that some actions, like not hiding the
2974 user agent, are part of a "general policy" that applies universally and won't
2975 get any exceptions defined later. Other choices, like not blocking (which is
2976 understandably the default!) need exceptions, i.e. we need to specify
2977 explicitly what we want to block in later sections. We will also want to make
2978 exceptions from our general pop-up-killing, and use our defined aliases for
2981 The first of our specialized sections is concerned with "fragile" sites, i.e.
2982 sites that require minimum interference, because they are either very complex
2983 or very keen on tracking you (and have mechanisms in place that make them
2984 unusable for people who avoid being tracked). We will simply use our
2985 pre-defined fragile alias instead of stating the list of actions explicitly:
2987 ##########################################################################
2988 # Exceptions for sites that'll break under the default action set:
2989 ##########################################################################
2991 # "Fragile" Use a minimum set of actions for these sites (see alias above):
2994 .office.microsoft.com # surprise, surprise!
2995 .windowsupdate.microsoft.com
2997 Shopping sites are not as fragile, but they typically require cookies to log
2998 in, and pop-up windows for shopping carts or item details. Again, we'll use a
3005 .worldpay.com # for quietpc.com
3009 Then, there are sites which rely on pop-up windows (yuck!) to work. Since we
3010 made pop-up-killing our default above, we need to make exceptions now. Mozilla
3011 users, who can turn on smart handling of unwanted pop-ups in their browsers,
3012 can safely choose -filter{popups} (and -kill-popups) above and hence don't need
3013 this section. Anyway, disabling an already disabled action doesn't hurt, so
3014 we'll define our exceptions regardless of what was chosen in the defaults
3017 # These sites require pop-ups too :(
3019 { -kill-popups -filter{popups} }
3022 .deutsche-bank-24.de
3024 The fast-redirects action, which we enabled per default above, breaks some
3025 sites. So disable it for popular sites where we know it misbehaves:
3031 .altavista.com/.*(like|url|link):http
3032 .altavista.com/trans.*urltext=http
3035 It is important that Privoxy knows which URLs belong to images, so that if they
3036 are to be blocked, a substitute image can be sent, rather than an HTML page.
3037 Contacting the remote site to find out is not an option, since it would destroy
3038 the loading time advantage of banner blocking, and it would feed the
3039 advertisers (in terms of money and information). We can mark any URL as an
3040 image with the handle-as-image action, and marking all URLs that end in a known
3041 image file extension is a good start:
3043 ##########################################################################
3045 ##########################################################################
3047 # Define which file types will be treated as images, in case they get
3048 # blocked further down this file:
3050 { +handle-as-image }
3051 /.*\.(gif|jpe?g|png|bmp|ico)$
3053 And then there are known banner sources. They often use scripts to generate the
3054 banners, so it won't be visible from the URL that the request is for an image.
3055 Hence we block them and mark them as images in one go, with the help of our
3056 block-as-image alias defined above. (We could of course just as well use +block
3057 +handle-as-image here.) Remember that the type of the replacement image is
3058 chosen by the set-image-blocker action. Since all URLs have matched the default
3059 section with its +set-image-blocker{pattern} action before, it still applies
3060 and needn't be repeated:
3062 # Known ad generators:
3067 .ad.*.doubleclick.net
3068 .a.yimg.com/(?:(?!/i/).)*$
3069 .a[0-9].yimg.com/(?:(?!/i/).)*$
3074 One of the most important jobs of Privoxy is to block banners. A huge bunch of
3075 them are already "blocked" by the filter{banners-by-size} action, which we
3076 enabled above, and which deletes the references to banner images from the pages
3077 while they are loaded, so the browser doesn't request them anymore, and hence
3078 they don't need to be blocked here. But this naturally doesn't catch all
3079 banners, and some people choose not to use filters, so we need a comprehensive
3080 list of patterns for banner URLs here, and apply the block action to them.
3082 First comes a bunch of generic patterns, which do most of the work, by matching
3083 typical domain and path name components of banners. Then comes a list of
3084 individual patterns for specific sites, which is omitted here to keep the
3087 ##########################################################################
3088 # Block these fine banners:
3089 ##########################################################################
3098 /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
3099 /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
3101 # Site-specific patterns (abbreviated):
3105 You wouldn't believe how many advertisers actually call their banner servers
3106 ads.company.com, or call the directory in which the banners are stored simply
3107 "banners". So the above generic patterns are surprisingly effective.
3109 But being very generic, they necessarily also catch URLs that we don't want to
3110 block. The pattern .*ads. e.g. catches "nasty-ads.nasty-corp.com" as intended,
3111 but also "downloads.sourcefroge.net" or "adsl.some-provider.net." So here come
3112 some well-known exceptions to the +block section above.
3114 Note that these are exceptions to exceptions from the default! Consider the URL
3115 "downloads.sourcefroge.net": Initially, all actions are deactivated, so it
3116 wouldn't get blocked. Then comes the defaults section, which matches the URL,
3117 but just deactivates the block action once again. Then it matches .*ads., an
3118 exception to the general non-blocking policy, and suddenly +block applies. And
3119 now, it'll match .*loads., where -block applies, so (unless it matches again
3120 further down) it ends up with no block action applying.
3122 ##########################################################################
3123 # Save some innocent victims of the above generic block patterns:
3124 ##########################################################################
3129 adv[io]*. # (for advogato.org and advice.*)
3130 adsl. # (has nothing to do with ads)
3131 ad[ud]*. # (adult.* and add.*)
3132 .edu # (universities don't host banners (yet!))
3133 .*loads. # (downloads, uploads etc)
3141 www.globalintersec.com/adv # (adv = advanced)
3142 www.ugu.com/sui/ugu/adv
3144 Filtering source code can have nasty side effects, so make an exception for our
3145 friends at sourceforge.net, and all paths with "cvs" in them. Note that -filter
3146 disables all filters in one fell swoop!
3148 # Don't filter code!
3154 The actual default.action is of course more comprehensive, but we hope this
3155 example made clear how it works.
3156 -------------------------------------------------------------------------------
3160 So far we are painting with a broad brush by setting general policies, which
3161 would be a reasonable starting point for many people. Now, you might want to be
3162 more specific and have customized rules that are more suitable to your personal
3163 habits and preferences. These would be for narrowly defined situations like
3164 your ISP or your bank, and should be placed in user.action, which is parsed
3165 after all other actions files and hence has the last word, over-riding any
3166 previously defined actions. user.action is also a safe place for your personal
3167 settings, since default.action is actively maintained by the Privoxy developers
3168 and you'll probably want to install updated versions from time to time.
3170 So let's look at a few examples of things that one might typically do in
3173 # My user.action file. <fred@foobar.com>
3175 As aliases are local to the actions file that they are defined in, you can't
3176 use the ones from default.action, unless you repeat them here:
3178 # (Re-)define aliases for this file:
3181 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
3182 mercy-for-cookies = -crunch-all-cookies -session-cookies-only
3183 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
3184 shop = mercy-for-cookies -filter{popups} -kill-popups
3185 allow-ads = -block -filter{banners-by-size} # (see below)
3187 Say you have accounts on some sites that you visit regularly, and you don't
3188 want to have to log in manually each time. So you'd like to allow persistent
3189 cookies for these sites. The mercy-for-cookies alias defined above does exactly
3190 that, i.e. it disables crunching of cookies in any direction, and processing of
3191 cookies to make them temporary.
3193 { mercy-for-cookies }
3200 Your bank needs popups and is allergic to some filter, but you don't know
3201 which, so you disable them all:
3203 { -filter -kill-popups }
3204 .your-home-banking-site.com
3206 While browsing the web with Privoxy you noticed some ads that sneaked through,
3207 but you were too lazy to report them through our fine and easy feedback system,
3208 so you have added them here:
3211 www.a-popular-site.com/some/unobvious/path
3212 another.popular.site.net/more/junk/here/
3214 Note that, assuming the banners in the above example have regular image
3215 extensions (most do), +handle-as-image need not be specified, since all URLs
3216 ending in these extensions will already have been tagged as images in the
3217 relevant section of default.action by now.
3219 Then you noticed that the default configuration breaks Forbes Magazine, but you
3220 were too lazy to find out which action is the culprit, and you were again too
3221 lazy to give feedback, so you just used the fragile alias on the site, and --
3227 You like the "fun" text replacements in default.filter, but it is disabled in
3228 the distributed actions file. (My colleagues on the team just don't have a
3229 sense of humour, that's why! ;-). So you'd like to turn it on in your private,
3230 update-safe config, once and for all:
3235 Note that the above is not really a good idea: There are exceptions to the
3236 filters in default.action for things that really shouldn't be filtered, like
3237 code on CVS->Web interfaces. Since user.action has the last word, these
3238 exceptions won't be valid for the "fun" filtering specified here.
3240 Finally, you might think about how your favourite free websites are funded, and
3241 find that they rely on displaying banner advertisements to survive. So you
3242 might want to specifically allow banners for those sites that you feel provide
3250 Note that allow-ads has been aliased to -block -filter{banners-by-size} above.
3251 -------------------------------------------------------------------------------
3255 All text substitutions that can be invoked through the filter action must first
3256 be defined in the filter file, which is typically called default.filter and
3257 which can be selected through the filterfile config option.
3259 Typical reasons for doing such substitutions are to eliminate common annoyances
3260 in HTML and JavaScript, such as pop-up windows, exit consoles, crippled windows
3261 without navigation tools, the infamous <BLINK> tag etc, to suppress images with
3262 certain width and height attributes (standard banner sizes or web-bugs), or
3263 just to have fun. The possibilities are endless.
3265 Filtering works on any text-based document type, including plain text, HTML,
3266 JavaScript, CSS etc. (all text/* MIME types). Substitutions are made at the
3267 source level, so if you want to "roll your own" filters, you should be familiar
3270 Just like the actions files, the filter file is organized in sections, which
3271 are called filters here. Each filter consists of a heading line, that starts
3272 with the keyword FILTER:, followed by the filter's name, and a short (one line)
3273 description of what it does. Below that line come the jobs, i.e. lines that
3274 define the actual text substitutions. By convention, the name of a filter
3275 should describe what the filter eliminates. The comment is used in the
3276 web-based user interface.
3278 Once a filter called name has been defined in the filter file, it can be
3279 invoked by using an action of the form +filter{name} in any actions file.
3281 A filter header line for a filter called "foo" could look like this:
3283 FILTER: foo Replace all "foo" with "bar"
3285 Below that line, and up to the next header line, come the jobs that define what
3286 text replacements the filter executes. They are specified in a syntax that
3287 imitates Perl's s/// operator. If you are familiar with Perl, you will find
3288 this to be quite intuitive, and may want to look at the PCRS man page for the
3289 subtle differences to Perl behaviour. Most notably, the non-standard option
3290 letter U is supported, which turns the default to ungreedy matching.
3292 If you are new to regular expressions, you might want to take a look at the
3293 Appendix on regular expressions, and see the Perl manual for the s///
3294 operator's syntax and Perl-style regular expressions in general. The below
3295 examples might also help to get you started.
3296 -------------------------------------------------------------------------------
3298 9.1. Filter File Tutorial
3300 Now, let's complete our "foo" filter. We have already defined the heading, but
3301 the jobs are still missing. Since all it does is to replace "foo" with "bar",
3302 there is only one (trivial) job needed:
3306 But wait! Didn't the comment say that all occurrences of "foo" should be
3307 replaced? Our current job will only take care of the first "foo" on each page.
3308 For global substitution, we'll need to add the g option:
3312 Our complete filter now looks like this:
3314 FILTER: foo Replace all "foo" with "bar"
3317 Let's look at some real filters for more interesting examples. Here you see a
3318 filter that protects against some common annoyances that arise from JavaScript
3319 abuse. Let's look at its jobs one after the other:
3321 FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse
3323 # Get rid of JavaScript referrer tracking. Test page: http://www.randomoddness.com/untitled.htm
3325 s|(<script.*)document\.referrer(.*</script>)|$1"Not Your Business!"$2|Usg
3327 Following the header line and a comment, you see the job. Note that it uses |
3328 as the delimiter instead of /, because the pattern contains a forward slash,
3329 which would otherwise have to be escaped by a backslash (\).
3331 Now, let's examine the pattern: it starts with the text <script.* enclosed in
3332 parentheses. Since the dot matches any character, and * means: "Match an
3333 arbitrary number of the element left of myself", this matches "<script",
3334 followed by any text, i.e. it matches the whole page, from the start of the
3337 That's more than we want, but the pattern continues: document\.referrer matches
3338 only the exact string "document.referrer". The dot needed to be escaped, i.e.
3339 preceded by a backslash, to take away its special meaning as a joker, and make
3340 it just a regular dot. So far, the meaning is: Match from the start of the
3341 first <script> tag in a the page, up to, and including, the text
3342 "document.referrer", if both are present in the page (and appear in that
3345 But there's still more pattern to go. The next element, again enclosed in
3346 parentheses, is .*</script>. You already know what .* means, so the whole
3347 pattern translates to: Match from the start of the first <script> tag in a page
3348 to the end of the last <script> tag, provided that the text "document.referrer"
3349 appears somewhere in between.
3351 This is still not the whole story, since we have ignored the options and the
3352 parentheses: The portions of the page matched by sub-patterns that are enclosed
3353 in parentheses, will be remembered and be available through the variables $1,
3354 $2, ... in the substitute. The U option switches to ungreedy matching, which
3355 means that the first .* in the pattern will only "eat up" all text in between "
3356 <script" and the first occurrence of "document.referrer", and that the second .
3357 * will only span the text up to the first "</script>" tag. Furthermore, the s
3358 option says that the match may span multiple lines in the page, and the g
3359 option again means that the substitution is global.
3361 So, to summarize, the pattern means: Match all scripts that contain the text
3362 "document.referrer". Remember the parts of the script from (and including) the
3363 start tag up to (and excluding) the string "document.referrer" as $1, and the
3364 part following that string, up to and including the closing tag, as $2.
3366 Now the pattern is deciphered, but wasn't this about substituting things? So
3367 lets look at the substitute: $1"Not Your Business!"$2 is easy to read: The text
3368 remembered as $1, followed by "Not Your Business!" (including the quotation
3369 marks!), followed by the text remembered as $2. This produces an exact copy of
3370 the original string, with the middle part (the "document.referrer") replaced by
3371 "Not Your Business!".
3373 The whole job now reads: Replace "document.referrer" by "Not Your Business!"
3374 wherever it appears inside a <script> tag. Note that this job won't break
3375 JavaScript syntax, since both the original and the replacement are
3376 syntactically valid string objects. The script just won't have access to the
3377 referrer information anymore.
3379 We'll show you two other jobs from the JavaScript taming department, but this
3380 time only point out the constructs of special interest:
3382 # The status bar is for displaying link targets, not pointless blahblah
3384 s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig
3386 \s stands for whitespace characters (space, tab, newline, carriage return, form
3387 feed), so that \s* means: "zero or more whitespace". The ? in .*? makes this
3388 matching of arbitrary text ungreedy. (Note that the U option is not set). The
3389 ['"] construct means: "a single or a double quote". Finally, \1 is a
3390 backreference to the first parenthesis just like $1 above, with the difference
3391 that in the pattern, a backslash indicates a backreference, whereas in the
3392 substitute, it's the dollar.
3394 So what does this job do? It replaces assignments of single- or double-quoted
3395 strings to the "window.status" object with a dummy assignment (using a variable
3396 name that is hopefully odd enough not to conflict with real variables in
3397 scripts). Thus, it catches many cases where e.g. pointless descriptions are
3398 displayed in the status bar instead of the link target when you move your mouse
3401 # Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html
3403 s/(<body [^>]*)onunload(.*>)/$1never$2/iU
3405 Including the OnUnload event binding in the HTML DOM was a CRIME. When I close
3406 a browser window, I want it to close and die. Basta. This job replaces the
3407 "onunload" attribute in "<body>" tags with the dummy word never. Note that the
3408 i option makes the pattern matching case-insensitive. Also note that ungreedy
3409 matching alone doesn't always guarantee a minimal match: In the first
3410 parenthesis, we had to use [^>]* instead of .* to prevent the match from
3411 exceeding the <body> tag if it doesn't contain "OnUnload", but the page's
3414 The last example is from the fun department:
3416 FILTER: fun Fun text replacements
3418 # Spice the daily news:
3420 s/microsoft(?!\.com)/MicroSuck/ig
3422 Note the (?!\.com) part (a so-called negative lookahead) in the job's pattern,
3423 which means: Don't match, if the string ".com" appears directly following
3424 "microsoft" in the page. This prevents links to microsoft.com from being
3425 trashed, while still replacing the word everywhere else.
3427 # Buzzword Bingo (example for extended regex syntax)
3429 s* industry[ -]leading \
3431 | customer[ -]focused \
3432 | market[ -]driven \
3433 | award[ -]winning # Comments are OK, too! \
3434 | high[ -]performance \
3435 | solutions[ -]based \
3439 *<font color="red"><b>BINGO!</b></font> \
3442 The x option in this job turns on extended syntax, and allows for e.g. the
3443 liberal use of (non-interpreted!) whitespace for nicer formatting.
3446 -------------------------------------------------------------------------------
3450 All Privoxy built-in pages, i.e. error pages such as the "404 - No Such Domain"
3451 error page, the "BLOCKED" page and all pages of its web-based user interface,
3452 are generated from templates. (Privoxy must be running for the above links to
3455 These templates are stored in a subdirectory of the configuration directory
3456 called templates. On Unixish platforms, this is typically /etc/privoxy/
3459 The templates are basically normal HTML files, but with place-holders (called
3460 symbols or exports), which Privoxy fills at run time. You can edit the
3461 templates with a normal text editor, should you want to customize them. (Not
3462 recommended for the casual user). Note that just like in configuration files,
3463 lines starting with # are ignored when the templates are filled in.
3465 The place-holders are of the form @name@, and you will find a list of available
3466 symbols, which vary from template to template, in the comments at the start of
3467 each file. Note that these comments are not always accurate, and that it's
3468 probably best to look at the existing HTML code to find out which symbols are
3469 supported and what they are filled in with.
3471 A special application of this substitution mechanism is to make whole blocks of
3472 HTML code disappear when a specific symbol is set. We use this for many
3473 purposes, one of them being to include the beta warning in all our user
3474 interface (CGI) pages when Privoxy in in an alpha or beta development stage:
3476 <!-- @if-unstable-start -->
3478 ... beta warning HTML code goes here ...
3480 <!-- if-unstable-end@ -->
3482 If the "unstable" symbol is set, everything in between and including
3483 @if-unstable-start and if-unstable-end@ will disappear, leaving nothing but an
3488 There's also an if-then-else construct and an #include mechanism, but you'll
3489 sure find out if you are inclined to edit the templates ;-)
3491 All templates refer to a style located at http://config.privoxy.org/
3492 send-stylesheet. This is, of course, locally served by Privoxy and the source
3493 for it can be found and edited in the cgi-style.css template.
3494 -------------------------------------------------------------------------------
3496 11. Contacting the Developers, Bug Reporting and Feature Requests
3498 We value your feedback. In fact, we rely on it to improve Privoxy and its
3499 configuration. However, please note the following hints, so we can provide you
3500 with the best support:
3501 -------------------------------------------------------------------------------
3505 For casual users, our support forum at SourceForge is probably best suited:
3506 http://sourceforge.net/tracker/?group_id=11118&atid=211118
3508 All users are of course welcome to discuss their issues on the users mailing
3509 list, where the developers also hang around.
3510 -------------------------------------------------------------------------------
3514 Please report all bugs only through our bug tracker: http://sourceforge.net/
3515 tracker/?group_id=11118&atid=111118.
3517 Before doing so, please make sure that the bug has not already been submitted
3518 and observe the additional hints at the top of the submit form.
3520 Please try to verify that it is a Privoxy bug, and not a browser or site bug
3521 first. If unsure, try toggling off Privoxy, and see if the problem persists.
3522 The appendix of the user manual also has helpful information on action
3523 debugging. If you are using your own custom configuration, please try the stock
3524 configs to see if the problem is configuration related.
3526 If not using the latest version, chances are that the bug has been found and
3527 fixed in the meantime. We would appreciate if you could take the time to
3528 upgrade to the latest version (or even the latest CVS snapshot) and verify your
3529 bug, but this is not required for reporting.
3530 -------------------------------------------------------------------------------
3532 11.3. Request New Features
3534 You are welcome to submit ideas on new features or other proposals for
3535 improvement through our feature request tracker at http://sourceforge.net/
3536 tracker/?atid=361118&group_id=11118.
3537 -------------------------------------------------------------------------------
3539 11.4. Report Ads or Other Actions-Related Problems
3541 Please send feedback on ads that slipped through, innocent images that were
3542 blocked, and any other problems relating to the default.action file through our
3543 actions feedback mechanism located at http://www.privoxy.org/actions/. On this
3544 page, you will also find a bookmark which will take you back there from any
3545 troubled site and even pre-fill the form!
3547 New, improved default.action files will occasionally be made available based on
3548 your feedback. These will be announced on the ijbswa-announce list and
3549 available from our the files section of our project page.
3550 -------------------------------------------------------------------------------
3554 For any other issues, feel free to use the mailing lists. Technically
3555 interested users and people who wish to contribute to the project are also
3556 welcome on the developers list! You can find an overview of all Privoxy-related
3557 mailing lists, including list archives, at: http://sourceforge.net/mail/?
3559 -------------------------------------------------------------------------------
3561 12. Privoxy Copyright, License and History
3563 Copyright © 2001, 2002 by Privoxy Developers <developers@privoxy.org>
3565 Some source code is based on code Copyright © 1997 by Anonymous Coders and
3566 Junkbusters, Inc. and licensed under the GNU General Public License.
3567 -------------------------------------------------------------------------------
3571 Privoxy is free software; you can redistribute it and/or modify it under the
3572 terms of the GNU General Public License, version 2, as published by the Free
3573 Software Foundation.
3575 This program is distributed in the hope that it will be useful, but WITHOUT ANY
3576 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
3577 PARTICULAR PURPOSE. See the GNU General Public License for more details, which
3578 is available from the Free Software Foundation, Inc, 59 Temple Place - Suite
3579 330, Boston, MA 02111-1307, USA.
3581 You should have received a copy of the GNU General Public License along with
3582 this program; if not, write to the
3585 Foundation, Inc. 59 Temple Place - Suite 330
3586 Boston, MA 02111-1307
3588 -------------------------------------------------------------------------------
3592 In the beginning, there was the Internet Junkbuster, by Anonymous Coders and
3593 Junkbusters Corporation. It saved many users a lot of pain in the early days of
3594 web advertising and user tracking.
3596 But the web, its protocols and standards, and with it, the techniques for
3597 forcing users to consume ads, give up autonomy over their browsing, and for
3598 spying on them, kept evolving. Unfortunately, the Internet Junkbuster did not.
3599 Version 2.0.2, published in 1998, was (and is) the last official release
3600 available from Junkbusters Corporation. Fortunately, it had been released under
3601 the GNU GPL, which allowed further development by others.
3603 So Stefan Waldherr started maintaining an improved version of the software, to
3604 which eventually a number of people contributed patches. It could already
3605 replace banners with a transparent image, and had a first version of pop-up
3606 killing, but it was still very closely based on the original, with all its
3607 limitations, such as the lack of HTTP/1.1 support, flexible per-site
3608 configuration, or content modification. The last release from this effort was
3609 version 2.0.2-10, published in 2000.
3611 Then, some developers picked up the thread, and started turning the software
3612 inside out, upside down, and then reassembled it, adding many new features
3615 The result of this is Privoxy, whose first stable release, 3.0, is due in June
3617 -------------------------------------------------------------------------------
3621 Current Project Developers:
3630 Current Project Contributors:
3632 Rodrigo Barbosa (RPM specfiles)
3639 David Schmidt (OS/2, Mac OSX ports)
3643 Based in part on code originally developed by:
3648 Thanks to the many people who have tested Privoxy, reported bugs, or made
3649 suggestions. These include (in alphabetical order):
3666 -------------------------------------------------------------------------------
3670 Other references and sites of interest to Privoxy users:
3672 http://www.privoxy.org/, the Privoxy Home page.
3674 http://www.privoxy.org/faq/, the Privoxy FAQ.
3676 http://sourceforge.net/projects/ijbswa/, the Project Page for Privoxy on
3679 http://config.privoxy.org/, the web-based user interface. Privoxy must be
3680 running for this to work. Shortcut: http://p.p/
3682 http://www.privoxy.org/actions/, to submit "misses" to the developers.
3684 http://www.junkbusters.com/ht/en/cookies.html, an explanation how cookies are
3685 used to track web users.
3687 http://www.junkbusters.com/ijb.html, the original Internet Junkbuster.
3689 http://www.waldherr.org/junkbuster/, Stefan Waldherr's version of Junkbuster,
3690 from which Privoxy was derived.
3692 http://privacy.net/analyze/, a useful site to check what information about you
3693 is leaked while you browse the web.
3695 http://www.squid-cache.org/, a very popular caching proxy, which is often used
3696 together with Privoxy.
3698 http://www.privoxy.org/developer-manual/, the Privoxy developer manual.
3700 -------------------------------------------------------------------------------
3703 14.1. Regular Expressions
3705 Privoxy uses Perl-style "regular expressions" in its actions files and filter
3706 file, through the PCRE and PCRS libraries.
3708 If you are reading this, you probably don't understand what "regular
3709 expressions" are, or what they can do. So this will be a very brief
3710 introduction only. A full explanation would require a book ;-)
3712 Regular expressions provide a language to describe patterns that can be run
3713 against strings of characters (letter, numbers, etc), to see if they match the
3714 string or not. The patterns are themselves (sometimes complex) strings of
3715 literal characters, combined with wild-cards, and other special characters,
3716 called meta-characters. The "meta-characters" have special meanings and are
3717 used to build complex patterns to be matched against. Perl Compatible Regular
3718 Expressions are an especially convenient "dialect" of the regular expression
3721 To make a simple analogy, we do something similar when we use wild-card
3722 characters when listing files with the dir command in DOS. *.* matches all
3723 filenames. The "special" character here is the asterisk which matches any and
3724 all characters. We can be more specific and use ? to match just individual
3725 characters. So "dir file?.text" would match "file1.txt", "file2.txt", etc. We
3726 are pattern matching, using a similar technique to "regular expressions"!
3728 Regular expressions do essentially the same thing, but are much, much more
3729 powerful. There are many more "special characters" and ways of building complex
3730 patterns however. Let's look at a few of the common ones, and then some
3733 . - Matches any single character, e.g. "a", "A", "4", ":", or "@".
3735 ? - The preceding character or expression is matched ZERO or ONE times. Either/
3738 + - The preceding character or expression is matched ONE or MORE times.
3740 * - The preceding character or expression is matched ZERO or MORE times.
3742 \ - The "escape" character denotes that the following character should be taken
3743 literally. This is used where one of the special characters (e.g. ".") needs to
3744 be taken literally and not as a special meta-character. Example: "example\.com"
3745 , makes sure the period is recognized only as a period (and not expanded to its
3746 meta-character meaning of any single character).
3748 [] - Characters enclosed in brackets will be matched if any of the enclosed
3749 characters are encountered. For instance, "[0-9]" matches any numeric digit
3750 (zero through nine). As an example, we can combine this with "+" to match any
3751 digit one of more times: "[0-9]+".
3753 () - parentheses are used to group a sub-expression, or multiple
3756 | - The "bar" character works like an "or" conditional statement. A match is
3757 successful if the sub-expression on either side of "|" matches. As an example:
3758 "/(this|that) example/" uses grouping and the bar character and would match
3759 either "this example" or "that example", and nothing else.
3761 These are just some of the ones you are likely to use when matching URLs with
3762 Privoxy, and is a long way from a definitive list. This is enough to get us
3763 started with a few simple examples which may be more illuminating:
3765 /.*/banners/.* - A simple example that uses the common combination of "." and "
3766 *" to denote any character, zero or more times. In other words, any string at
3767 all. So we start with a literal forward slash, then our regular expression
3768 pattern (".*") another literal forward slash, the string "banners", another
3769 forward slash, and lastly another ".*". We are building a directory path here.
3770 This will match any file with the path that has a directory named "banners" in
3771 it. The ".*" matches any characters, and this could conceivably be more forward
3772 slashes, so it might expand into a much longer looking path. For example, this
3773 could match: "/eye/hate/spammers/banners/annoy_me_please.gif", or just "/
3774 banners/annoying.html", or almost an infinite number of other possible
3775 combinations, just so it has "banners" in the path somewhere.
3777 A now something a little more complex:
3779 /.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward
3780 slashes again ("/"), so we are building another expression that is a file path
3781 statement. We have another ".*", so we are matching against any conceivable
3782 sub-path, just so it matches our expression. The only true literal that must
3783 match our pattern is adv, together with the forward slashes. What comes after
3784 the "adv" string is the interesting part.
3786 Remember the "?" means the preceding expression (either a literal character or
3787 anything grouped with "(...)" in this case) can exist or not, since this means
3788 either zero or one match. So "((er)?ts?|ertis(ing|ements?))" is optional, as
3789 are the individual sub-expressions: "(er)", "(ing|ements?)", and the "s". The "
3790 |" means "or". We have two of those. For instance, "(ing|ements?)", can expand
3791 to match either "ing" OR "ements?". What is being done here, is an attempt at
3792 matching as many variations of "advertisement", and similar, as possible. So
3793 this would expand to match just "adv", or "advert", or "adverts", or
3794 "advertising", or "advertisement", or "advertisements". You get the idea. But
3795 it would not match "advertizements" (with a "z"). We could fix that by changing
3796 our regular expression to: "/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/", which
3797 would then match either spelling.
3799 /.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward
3800 slashes. Anything in the square brackets "[]" can be matched. This is using
3801 "0-9" as a shorthand expression to mean any digit one through nine. It is the
3802 same as saying "0123456789". So any digit matches. The "+" means one or more of
3803 the preceding expression must be included. The preceding expression here is
3804 what is in the square brackets -- in this case, any digit one through nine.
3805 Then, at the end, we have a grouping: "(gif|jpe?g)". This includes a "|", so
3806 this needs to match the expression on either side of that bar character also. A
3807 simple "gif" on one side, and the other side will in turn match either "jpeg"
3808 or "jpg", since the "?" means the letter "e" is optional and can be matched
3809 once or not at all. So we are building an expression here to match image GIF or
3810 JPEG type image file. It must include the literal string "advert", then one or
3811 more digits, and a "." (which is now a literal, and not a special character,
3812 since it is escaped with "\"), and lastly either "gif", or "jpeg", or "jpg".
3813 Some possible matches would include: "//advert1.jpg", "/nasty/ads/
3814 advert1234.gif", "/banners/from/hell/advert99.jpg". It would not match
3815 "advert1.gif" (no leading slash), or "/adverts232.jpg" (the expression does not
3816 include an "s"), or "/advert1.jsp" ("jsp" is not in the expression anywhere).
3818 We are barely scratching the surface of regular expressions here so that you
3819 can understand the default Privoxy configuration files, and maybe use this
3820 knowledge to customize your own installation. There is much, much more that can
3821 be done with regular expressions. Now that you know enough to get started, you
3822 can learn more on your own :/
3824 More reading on Perl Compatible Regular expressions: http://www.perldoc.com/
3825 perl5.6/pod/perlre.html
3827 For information on regular expression based substitutions and their
3828 applications in filters, please see the filter file tutorial in this manual.
3829 -------------------------------------------------------------------------------
3831 14.2. Privoxy's Internal Pages
3833 Since Privoxy proxies each requested web page, it is easy for Privoxy to trap
3834 certain special URLs. In this way, we can talk directly to Privoxy, and see how
3835 it is configured, see how our rules are being applied, change these rules and
3836 other configuration options, and even turn Privoxy's filtering off, all with a
3839 The URLs listed below are the special ones that allow direct access to Privoxy.
3840 Of course, Privoxy must be running to access these. If not, you will get a
3841 friendly error message. Internet access is not necessary either.
3843 * Privoxy main page:
3846 http://config.privoxy.org/
3849 There is a shortcut: http://p.p/ (But it doesn't provide a fall-back to a
3850 real page, in case the request is not sent through Privoxy)
3852 * Show information about the current configuration, including viewing and
3853 editing of actions files:
3856 http://config.privoxy.org/show-status
3859 * Show the source code version numbers:
3862 http://config.privoxy.org/show-version
3865 * Show the browser's request headers:
3868 http://config.privoxy.org/show-request
3871 * Show which actions apply to a URL and why:
3874 http://config.privoxy.org/show-url-info
3877 * Toggle Privoxy on or off. In this case, "Privoxy" continues to run, but
3878 only as a pass-through proxy, with no actions taking place:
3881 http://config.privoxy.org/toggle
3884 Short cuts. Turn off, then on:
3887 http://config.privoxy.org/toggle?set=disable
3891 http://config.privoxy.org/toggle?set=enable
3895 These may be bookmarked for quick reference. See next.
3896 -------------------------------------------------------------------------------
3898 14.2.1. Bookmarklets
3900 Below are some "bookmarklets" to allow you to easily access a "mini" version of
3901 some of Privoxy's special pages. They are designed for MS Internet Explorer,
3902 but should work equally well in Netscape, Mozilla, and other browsers which
3903 support JavaScript. They are designed to run directly from your bookmarks - not
3904 by clicking the links below (although that should work for testing).
3906 To save them, right-click the link and choose "Add to Favorites" (IE) or "Add
3907 Bookmark" (Netscape). You will get a warning that the bookmark "may not be
3908 safe" - just click OK. Then you can run the Bookmarklet directly from your
3909 favorites/bookmarks. For even faster access, you can put them on the "Links"
3910 bar (IE) or the "Personal Toolbar" (Netscape), and run them with a single
3917 * Privoxy - Toggle Privoxy (Toggles between enabled and disabled)
3919 * Privoxy- View Status
3921 * Privoxy - Submit Actions File Feedback
3926 Credit: The site which gave us the general idea for these bookmarklets is
3927 www.bookmarklets.com. They have more information about bookmarklets.
3928 -------------------------------------------------------------------------------
3930 14.3. Chain of Events
3932 Let's take a quick look at the basic sequence of events when a web page is
3933 requested by your browser and Privoxy is on duty:
3935 * First, your web browser requests a web page. The browser knows to send the
3936 request to Privoxy, which will in turn, relay the request to the remote web
3937 server after passing the following tests:
3939 * Privoxy traps any request for its own internal CGI pages (e.g http://p.p/)
3940 and sends the CGI page back to the browser.
3942 * Next, Privoxy checks to see if the URL matches any "+block" patterns. If
3943 so, the URL is then blocked, and the remote web server will not be
3944 contacted. "+handle-as-image" is then checked and if it does not match, an
3945 HTML "BLOCKED" page is sent back. Otherwise, if it does match, an image is
3946 returned. The type of image depends on the setting of "+set-image-blocker"
3947 (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
3949 * Untrusted URLs are blocked. If URLs are being added to the trust file, then
3952 * If the URL pattern matches the "+fast-redirects" action, it is then
3953 processed. Unwanted parts of the requested URL are stripped.
3955 * Now the rest of the client browser's request headers are processed. If any
3956 of these match any of the relevant actions (e.g. "+hide-user-agent", etc.),
3957 headers are suppressed or forged as determined by these actions and their
3960 * Now the web server starts sending its response back (i.e. typically a web
3961 page and related data).
3963 * First, the server headers are read and processed to determine, among other
3964 things, the MIME type (document type) and encoding. The headers are then
3965 filtered as deterimined by the "+crunch-incoming-cookies",
3966 "+session-cookies-only", and "+downgrade-http-version" actions.
3968 * If the "+kill-popups" action applies, and it is an HTML or JavaScript
3969 document, the popup-code in the response is filtered on-the-fly as it is
3972 * If a "+filter" or "+deanimate-gifs" action applies (and the document type
3973 fits the action), the rest of the page is read into memory (up to a
3974 configurable limit). Then the filter rules (from default.filter) are
3975 processed against the buffered content. Filters are applied in the order
3976 they are specified in the default.filter file. Animated GIFs, if present,
3977 are reduced to either the first or last frame, depending on the action
3978 setting.The entire page, which is now filtered, is then sent by Privoxy
3979 back to your browser.
3981 If neither "+filter" or "+deanimate-gifs" matches, then Privoxy passes the
3982 raw data through to the client browser as it becomes available.
3984 * As the browser receives the now (probably filtered) page content, it reads
3985 and then requests any URLs that may be embedded within the page source,
3986 e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
3987 frames), sounds, etc. For each of these objects, the browser issues a new
3988 request. And each such request is in turn processed as above. Note that a
3989 complex web page may have many such embedded URLs.
3992 -------------------------------------------------------------------------------
3993 14.4. Anatomy of an Action
3995 The way Privoxy applies actions and filters to any given URL can be complex,
3996 and not always so easy to understand what is happening. And sometimes we need
3997 to be able to see just what Privoxy is doing. Especially, if something Privoxy
3998 is doing is causing us a problem inadvertently. It can be a little daunting to
3999 look at the actions and filters files themselves, since they tend to be filled
4000 with regular expressions whose consequences are not always so obvious.
4002 One quick test to see if Privoxy is causing a problem or not, is to disable it
4003 temporarily. This should be the first troubleshooting step. See the
4004 Bookmarklets section on a quick and easy way to do this (be sure to flush
4005 caches afterward!). Looking at the logs is a good idea too.
4007 Privoxy also provides the http://config.privoxy.org/show-url-info page that can
4008 show us very specifically how actions are being applied to any given URL. This
4009 is a big help for troubleshooting.
4011 First, enter one URL (or partial URL) at the prompt, and then Privoxy will tell
4012 us how the current configuration will handle it. This will not help with
4013 filtering effects (i.e. the "+filter" action) from the default.filter file
4014 since this is handled very differently and not so easy to trap! It also will
4015 not tell you about any other URLs that may be embedded within the URL you are
4016 testing. For instance, images such as ads are expressed as URLs within the raw
4017 page source of HTML pages. So you will only get info for the actual URL that is
4018 pasted into the prompt area -- not any sub-URLs. If you want to know about
4019 embedded URLs like ads, you will have to dig those out of the HTML source. Use
4020 your browser's "View Page Source" option for this. Or right click on the ad,
4023 Let's try an example, google.com, and look at it one section at a time:
4025 Matches for http://google.com:
4027 In file: default.action [ View ] [ Edit ]
4031 -crunch-outgoing-cookies
4032 -crunch-incoming-cookies
4033 +deanimate-gifs{last}
4034 -downgrade-http-version
4038 -filter{shockwave-flash}
4039 -filter{crude-parental}
4040 +filter{html-annoyances}
4041 +filter{js-annoyances}
4042 +filter{content-cookies}
4044 +filter{refresh-tags}
4046 +filter{banners-by-size}
4047 +hide-forwarded-for-headers
4048 +hide-from-header{block}
4049 +hide-referer{forge}
4054 +prevent-compression
4057 +session-cookies-only
4058 +set-image-blocker{pattern} }
4061 { -session-cookies-only }
4067 In file: user.action [ View ] [ Edit ]
4068 (no matches in this file)
4070 This tells us how we have defined our "actions", and which ones match for our
4071 example, "google.com". The first listing is any matches for the standard.action
4072 file. No hits at all here on "standard". Then next is "default", or our
4073 default.action file. The large, multi-line listing, is how the actions are set
4074 to match for all URLs, i.e. our default settings. If you look at your "actions"
4075 file, this would be the section just below the "aliases" section near the top.
4076 This will apply to all URLs as signified by the single forward slash at the end
4077 of the listing -- "/".
4079 But we can define additional actions that would be exceptions to these general
4080 rules, and then list specific URLs (or patterns) that these exceptions would
4081 apply to. Last match wins. Just below this then are two explicit matches for
4082 ".google.com". The first is negating our previous cookie setting, which was for
4083 "+session-cookies-only" (i.e. not persistent). So we will allow persistent
4084 cookies for google. The second turns off any "+fast-redirects" action, allowing
4085 this to take place unmolested. Note that there is a leading dot here --
4086 ".google.com". This will match any hosts and sub-domains, in the google.com
4087 domain also, such as "www.google.com". So, apparently, we have these two
4088 actions defined somewhere in the lower part of our default.action file, and
4089 "google.com" is referenced somewhere in these latter sections.
4091 Then, for our user.action file, we again have no hits.
4093 And finally we pull it all together in the bottom section and summarize how
4094 Privoxy is applying all its "actions" to "google.com":
4100 -crunch-outgoing-cookies
4101 -crunch-incoming-cookies
4102 +deanimate-gifs{last}
4103 -downgrade-http-version
4107 -filter{shockwave-flash}
4108 -filter{crude-parental}
4109 +filter{html-annoyances}
4110 +filter{js-annoyances}
4111 +filter{content-cookies}
4113 +filter{refresh-tags}
4115 +filter{banners-by-size}
4116 +hide-forwarded-for-headers
4117 +hide-from-header{block}
4118 +hide-referer{forge}
4123 +prevent-compression
4126 -session-cookies-only
4127 +set-image-blocker{pattern}
4129 Notice the only difference here to the previous listing, is to "fast-redirects"
4130 and "session-cookies-only".
4132 Now another example, "ad.doubleclick.net":
4134 { +block +handle-as-image }
4137 { +block +handle-as-image }
4140 { +block +handle-as-image }
4143 We'll just show the interesting part here, the explicit matches. It is matched
4144 three different times. Each as an "+block +handle-as-image", which is the
4145 expanded form of one of our aliases that had been defined as: "+imageblock". (
4146 "Aliases" are defined in the first section of the actions file and typically
4147 used to combine more than one action.)
4149 Any one of these would have done the trick and blocked this as an unwanted
4150 image. This is unnecessarily redundant since the last case effectively would
4151 also cover the first. No point in taking chances with these guys though ;-)
4152 Note that if you want an ad or obnoxious URL to be invisible, it should be
4153 defined as "ad.doubleclick.net" is done here -- as both a "+block" and an
4154 "+handle-as-image". The custom alias "+imageblock" just simplifies the process
4155 and make it more readable.
4157 One last example. Let's try "http://www.rhapsodyk.net/adsl/HOWTO/". This one is
4158 giving us problems. We are getting a blank page. Hmmm ...
4160 Matches for http://www.rhapsodyk.net/adsl/HOWTO/:
4162 In file: default.action [ View ] [ Edit ]
4166 -crunch-incoming-cookies
4167 -crunch-outgoing-cookies
4169 -downgrade-http-version
4171 +filter{html-annoyances}
4172 +filter{js-annoyances}
4173 +filter{kill-popups}
4176 +filter{banners-by-size}
4179 +hide-forwarded-for-headers
4180 +hide-from-header{block}
4181 +hide-referer{forge}
4185 +prevent-compression
4188 +session-cookies-only
4189 +set-image-blocker{blank} }
4192 { +block +handle-as-image }
4195 Ooops, the "/adsl/" is matching "/ads"! But we did not want this at all! Now we
4196 see why we get the blank page. We could now add a new action below this that
4197 explicitly does not block ("{-block}") paths with "adsl". There are various
4198 ways to handle such exceptions. Example:
4203 Now the page displays ;-) Be sure to flush your browser's caches when making
4204 such changes. Or, try using Shift+Reload.
4206 But now what about a situation where we get no explicit matches like we did
4209 { +block +handle-as-image }
4212 That actually was very telling and pointed us quickly to where the problem was.
4213 If you don't get this kind of match, then it means one of the default rules in
4214 the first section is causing the problem. This would require some guesswork,
4215 and maybe a little trial and error to isolate the offending rule. One likely
4216 cause would be one of the "{+filter}" actions. These tend to be harder to
4217 troubleshoot. Try adding the URL for the site to one of aliases that turn off
4222 .worldpay.com # for quietpc.com
4227 "{shop}" is an "alias" that expands to "{ -filter -session-cookies-only }". Or
4228 you could do your own exception to negate filtering:
4233 This would turn off all filtering for that site. This would probably be most
4234 appropriately put in user.action, for local site exceptions.
4236 Images that are inexplicably being blocked, may well be hitting the "+filter
4237 {banners-by-size}" rule, which assumes that images of certain sizes are ad
4238 banners (works well most of the time since these tend to be standardized).
4240 "{fragile}" is an alias that disables most actions. This can be used as a last
4241 resort for problem sites. Remember to flush caches! If this still does not
4242 work, you will have to go through the remaining actions one by one to find
4243 which one(s) is causing the problem.
projects / privoxy.git / blob