1 Privoxy 2.9.18 User Manual
3 Copyright © 2001, 2002 by Privoxy Developers
5 $Id: user-manual.sgml,v 1.123.2.14 2002/08/06 09:16:13 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
41 2.2. Building from Source
42 2.3. Keeping your Installation Up-to-Date
46 4. Quickstart to Using Privoxy
47 4.1. Quickstart to Ad Blocking
51 5.1. Red Hat and Conectiva
55 5.5. Solaris, NetBSD, FreeBSD, HP-UX and others
60 5.10. Command Line Options
63 6. Privoxy Configuration
64 6.1. Controlling Privoxy with Your Web Browser
65 6.2. Configuration Files Overview
68 7. The Main Configuration File
69 7.1. Configuration and Log File Locations
79 7.2. Local Set-up Documentation
88 7.3.2. single-threaded
91 7.4. Access Control and Security
94 7.4.3. enable-remote-toggle
95 7.4.4. enable-edit-actions
96 7.4.5. ACLs: permit-access and deny-access
102 7.5.2. forward-socks4 and forward-socks4a
103 7.5.3. Advanced Forwarding Examples
106 7.6. Windows GUI Options
110 8.1. Finding the Right Mix
112 8.3. How Actions are Applied to URLs
115 8.4.1. The Domain Pattern
116 8.4.2. The Path Pattern
122 8.5.3. crunch-incoming-cookies
123 8.5.4. crunch-outgoing-cookies
124 8.5.5. deanimate-gifs
125 8.5.6. downgrade-http-version
126 8.5.7. fast-redirects
128 8.5.9. handle-as-image
129 8.5.10. hide-forwarded-for-headers
130 8.5.11. hide-from-header
131 8.5.12. hide-referrer
132 8.5.13. hide-user-agent
134 8.5.15. limit-connect
135 8.5.16. prevent-compression
136 8.5.17. send-vanilla-wafer
138 8.5.19. session-cookies-only
139 8.5.20. set-image-blocker
144 8.7. Actions Files Tutorial
145 8.7.1. default.action
152 9.1. Filter File Tutorial
156 11. Contacting the Developers, Bug Reporting and Feature Requests
159 11.3. Request New Features
160 11.4. Report Ads or Other Actions-Related Problems
164 12. Privoxy Copyright, License and History
172 14.1. Regular Expressions
173 14.2. Privoxy's Internal Pages
177 14.3. Chain of Events
178 14.4. Anatomy of an Action
184 This documentation is included with the current beta version of Privoxy,
185 v.2.9.18, and is mostly complete at this point. The most up to date reference
186 for the time being is still the comments in the source files and in the
187 individual configuration files. Development of version 3.0 is currently nearing
188 completion, and includes many significant changes and enhancements over earlier
189 versions. The target release date for stable v3.0 is "soon" ;-).
191 Since this is a beta version, not all new features are well tested. This
192 documentation may be slightly out of sync as a result (especially with CVS
193 sources). And there may be bugs, though hopefully not many!
194 -------------------------------------------------------------------------------
198 In addition to Internet Junkbuster's traditional features of ad and banner
199 blocking and cookie management, Privoxy provides new features, some of them
200 currently under development:
202 * Integrated browser based configuration and control utility at http://
203 config.privoxy.org/ (shortcut: http://p.p/). Browser-based tracing of rule
204 and filter effects. Remote toggling.
206 * Web page content filtering (removes banners based on size, invisible
207 "web-bugs", JavaScript and HTML annoyances, pop-up windows, etc.)
209 * Modularized configuration that allows for standard settings and user
210 settings to reside in separate files, so that installing updated actions
211 files won't overwrite individual user settings.
213 * HTTP/1.1 compliant (but not all optional 1.1 features are supported).
215 * Support for Perl Compatible Regular Expressions in the configuration files,
216 and generally a more sophisticated and flexible configuration syntax over
219 * Improved cookie management features (e.g. session based cookies).
223 * Bypass many click-tracking scripts (avoids script redirection).
225 * Multi-threaded (POSIX and native threads).
227 * User-customizable HTML templates for all proxy-generated pages (e.g.
230 * Auto-detection and re-reading of config file changes.
232 * Improved signal handling, and a true daemon mode (Unix).
234 * Every feature now controllable on a per-site or per-location basis,
235 configuration more powerful and versatile over-all.
237 * Many smaller new features added, limitations and bugs removed, and security
241 -------------------------------------------------------------------------------
244 Privoxy is available both in convenient pre-compiled packages for a wide range
245 of operating systems, and as raw source code. For most users, we recommend
246 using the packages, which can be downloaded from our Privoxy Project Page.
248 Note: If you have a previous Junkbuster or Privoxy installation on your system,
249 you will need to remove it. On some platforms, this may be done for you as part
250 of their installation procedure. (See below for your platform). In any case be
251 sure to backup your old configuration if it is valuable to you. See the note to
252 upgraders section below.
253 -------------------------------------------------------------------------------
257 How to install the binary packages depends on your operating system:
258 -------------------------------------------------------------------------------
260 2.1.1. Red Hat, SuSE and Conectiva RPMs
262 RPMs can be installed with rpm -Uvh privoxy-2.9.18-1.rpm, and will use /etc/
263 privoxy for the location of configuration files.
265 Note that on Red Hat, Privoxy will not be automatically started on system boot.
266 You will need to enable that using chkconfig, ntsysv, or similar methods. Note
267 that SuSE will automatically start Privoxy in the boot process.
269 If you have problems with failed dependencies, try rebuilding the SRC RPM: rpm
270 --rebuild privoxy-2.9.18-1.src.rpm. This will use your locally installed
271 libraries and RPM version.
273 Also note that if you have a Junkbuster RPM installed on your system, you need
274 to remove it first, because the packages conflict. Otherwise, RPM will try to
275 remove Junkbuster automatically, before installing Privoxy.
276 -------------------------------------------------------------------------------
280 DEBs can be installed with dpkg -i privoxy_2.9.18-1.deb, and will use /etc/
281 privoxy for the location of configuration files.
282 -------------------------------------------------------------------------------
286 Just double-click the installer, which will guide you through the installation
287 process. You will find the configuration files in the same directory as you
288 installed Privoxy in. We do not use the registry of Windows.
289 -------------------------------------------------------------------------------
291 2.1.4. Solaris, NetBSD, FreeBSD, HP-UX
293 Create a new directory, cd to it, then unzip and untar the archive. For the
294 most part, you'll have to figure out where things go.
295 -------------------------------------------------------------------------------
299 First, make sure that no previous installations of Junkbuster and / or Privoxy
300 are left on your system. Check that no Junkbuster or Privoxy objects are in
303 Then, just double-click the WarpIN self-installing archive, which will guide
304 you through the installation process. A shadow of the Privoxy executable will
305 be placed in your startup folder so it will start automatically whenever OS/2
308 The directory you choose to install Privoxy into will contain all of the
310 -------------------------------------------------------------------------------
314 Unzip the downloaded package (you can either double-click on the file in the
315 finder, or on the desktop if you downloaded it there). The Privoxy.pkg package
316 should appear after unzipping. Then, double-click on that Privoxy.pkg package
317 installer icon and follow the installation process. Privoxy will be installed
318 in the folder /Library/Privoxy. It will run automatically whenever you start
319 up. To prevent it from running automatically, remove or rename the folder /
320 Library/StartupItems/Privoxy.
322 To run Privoxy by hand, double-click on RunPrivoxy.command. To run Privoxy from
323 Terminal, execute /Library/Privoxy/RunPrivoxy.command.
324 -------------------------------------------------------------------------------
328 Copy and then unpack the lha archive to a suitable location. All necessary
329 files will be installed into Privoxy directory, including all configuration and
330 log files. To uninstall, just remove this directory.
331 -------------------------------------------------------------------------------
335 Gentoo source packages (Ebuilds) for Privoxy are contained in the Gentoo
336 Portage Tree (they are not on the download page, but there is a Gentoo section,
337 where you can see when a new Privoxy Version is added to the Portage Tree).
339 Before installing Privoxy under Gentoo just do first emerge rsync to get the
340 latest changes from the Portage tree. With emerge privoxy you install the
343 Configuration files are in /etc/privoxy, the documentation is in /usr/share/doc
344 /privoxy-2.9.18 and the Log directory is in /var/log/privoxy.
345 -------------------------------------------------------------------------------
347 2.2. Building from Source
349 The most convenient way to obtain the Privoxy sources is to download the source
350 tarball from our project page.
352 If you like to live on the bleeding edge and are not afraid of using possibly
353 unstable development versions, you can check out the up-to-the-minute version
354 directly from the CVS repository or simply download the nightly CVS tarball.
356 To build Privoxy from source, autoconf, GNU make (gmake), and, of course, a C
357 compiler like gcc are required.
359 When building from a source tarball (either release version or nightly CVS
360 tarball), first unpack the source:
362 tar xzvf privoxy-2.9.18-beta-src* [.tgz or .tar.gz]
363 cd privoxy-2.9.18-beta
365 For retrieving the current CVS sources, you'll need CVS installed. Note that
366 sources from CVS are development quality, and may not be stable, or well
367 tested. To download CVS source:
369 cvs -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa login
370 cvs -z3 -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa co current
373 This will create a directory named current/, which will contain the source
376 Then, in either case, to build from unpacked tarball or CVS source:
380 ./configure # (--help to see options)
381 make # (the make from gnu, gmake for *BSD)
383 make -n install # (to see where all the files will go)
384 make install # (to really install)
386 If you have gnu make, you can have the first four steps automatically done for
391 in the freshly downloaded or unpacked source directory.
393 For more detailed instructions on how to build Redhat and SuSE RPMs, Windows
394 self-extracting installers, building on platforms with special requirements
395 etc, please consult the developer manual.
396 -------------------------------------------------------------------------------
398 2.3. Keeping your Installation Up-to-Date
400 As user feedback comes in and development continues, we will make updated
401 versions of both the main actions file (as a separate package) and the software
402 itself (including the actions file) available for download.
404 If you wish to receive an email notification whenever we release updates of
405 Privoxy or the actions file, subscribe to our announce mailing list,
406 ijbswa-announce@lists.sourceforge.net.
408 In order not to loose your personal changes and adjustments when updating to
409 the latest default.action file we strongly recommend that you use user.action
410 for your customization of Privoxy. See the Chapter on actions files for
412 -------------------------------------------------------------------------------
416 There are very significant changes from earlier Junkbuster versions to the
417 current Privoxy. The number, names, syntax, and purposes of configuration files
418 have substantially changed. Junkbuster 2.0.x configuration files will not
419 migrate, Junkbuster 2.9.x and Privoxy configurations will need to be ported.
420 The functionalities of the old blockfile, cookiefile and imagelist are now
421 combined into the "actions files". default.action, is the main actions file.
422 Local exceptions should best be put into user.action.
424 A "filter file" (typically default.filter) is new as of Privoxy 2.9.x, and
425 provides some of the new sophistication (explained below). config is much the
428 If upgrading from a 2.0.x version, you will have to use the new config files,
429 and possibly adapt any personal rules from your older files. When porting
430 personal rules over from the old blockfile to the new actions files, please
431 note that even the pattern syntax has changed. If upgrading from 2.9.x
432 development versions, it is still recommended to use the new configuration
435 A quick list of things to be aware of before upgrading:
437 * The default listening port is now 8118 due to a conflict with another
440 * Some installers may remove earlier versions completely. Save any important
443 * Privoxy is controllable with a web browser at the special URL: http://
444 config.privoxy.org/ (Shortcut: http://p.p/). Many aspects of configuration
445 can be done here, including temporarily disabling Privoxy.
447 * The primary configuration files for cookie management, ad and banner
448 blocking, and many other aspects of Privoxy configuration are the actions
449 files. It is strongly recommended to become familiar with the new actions
450 concept below, before modifying these files. Locally defined rules should
453 * Some installers may not automatically start Privoxy after installation.
456 -------------------------------------------------------------------------------
457 4. Quickstart to Using Privoxy
459 * If upgrading, from versions before 2.9.16, please back up any configuration
460 files. See the Note to Upgraders Section.
462 * Install Privoxy. See the Installation Section below for platform specific
465 * Advanced users and those who want to offer Privoxy service to more than
466 just their local machine should check the main config file, especially the
467 security-relevant options. These are off by default.
469 * Start Privoxy, if the installation program has not done this already (may
470 vary according to platform). See the section Starting Privoxy.
472 * Set your browser to use Privoxy as HTTP and HTTPS proxy by setting the
473 proxy configuration for address of 127.0.0.1 and port 8118. (Junkbuster and
474 earlier versions of Privoxy used port 8000.) See the section Starting
475 Privoxy below for more details on this.
477 * Flush your browser's disk and memory caches, to remove any cached ad
480 * A default installation should provide a reasonable starting point for most.
481 There will undoubtedly be occasions where you will want to adjust the
482 configuration, but that can be dealt with as the need arises. Little to no
483 initial configuration is required in most cases.
485 See the Configuration section for more configuration options, and how to
486 customize your installation.
488 * If you experience ads that slipped through, innocent images that are
489 blocked, or otherwise feel the need to fine-tune Privoxy's behaviour, take
490 a look at the actions files. As a quick start, you might find the richly
491 commented examples helpful. You can also view and edit the actions files
492 through the web-based user interface. The Appendix "Anatomy of an Action"
493 has hints how to debug actions that "misbehave".
495 * Please see the section Contacting the Developers on how to report bugs or
496 problems with websites or to get help.
498 * Now enjoy surfing with enhanced comfort and privacy!
501 -------------------------------------------------------------------------------
502 4.1. Quickstart to Ad Blocking
504 Ad blocking is but one of Privoxy's array of features. Many of these features
505 are for the technically minded advanced user. But, ad and banner blocking is
506 surely common ground for everybody.
508 This section will provide a quick summary of ad blocking so you can get up to
509 speed quickly without having to read the more extensive information provided
510 below, though this is highly recommended.
512 First a bit of a warning ... blocking ads is much like blocking SPAM: the more
513 aggressive you are about it, the more likely you are to block things that were
514 not intended. So there is a trade off here. If you want extreme ad free
515 browsing, be prepared to deal with more "problem" sites, and to spend more time
516 adjusting the configuration to solve these unintended consequences. In short,
517 there is not an easy way to eliminate all ads. Either take the easy way and
518 settle for most ads blocked with the default configuration, or jump in and
519 tweak it for your personal surfing habits and preferences.
521 Secondly, a brief explanation of Privoxy's "actions". "Actions" in this
522 context, are the directives we use to tell Privoxy to perform some task
523 relating to HTTP transactions (i.e. web browsing). We tell Privoxy to take some
524 "action". Each action has a unique name and function. While there are many
525 potential actions in Privoxy's arsenal, only a few are used for ad blocking.
526 Actions, and action configuration files, are explained in depth below.
528 Actions are specified in Privoxy's configuration, followed by one or more URLs
529 to which the action should apply. URLs can actually be URL type patterns that
530 use wildcards so they can apply potentially to a range of similar URLs. The
531 actions, together with the URL patterns are called a section.
533 When you connect to a website, the full URL will either match one or more of
534 the sections as defined in Privoxy's configuration, or not. If so, then Privoxy
535 will perform the respective actions. If not, then nothing special happens.
536 Furthermore, web pages may contain embedded, secondary URLs that your web
537 browser will use to load additional components of the page, as it parses the
538 original page's HTML content. An ad image for instance, is just an URL embedded
539 in the page somewhere. The image itself may be on the same server, or a server
540 somewhere else on the Internet. Complex web pages will have many such embedded
543 The actions we need to know about for ad blocking are: block, handle-as-image,
544 and set-image-blocker:
546 * block - this action stops any contact between your browser and any URL
547 patterns that match this action's configuration. It can be used for
548 blocking ads, but also anything that is determined to be unwanted. By
549 itself, it simply stops any communication with the remote server and sends
550 Privoxy's own built-in BLOCKED page instead to let you now what has
553 * handle-as-image - tells Privoxy to treat this URL as an image. Privoxy's
554 default configuration already does this for all common image types (e.g.
555 GIF), but there are many situations where this is not so easy to determine.
556 So we'll force it in these cases. This is particularly important for ad
557 blocking, since only if we know that it's an image of some kind, can we
558 replace it with an image of our choosing, instead of the Privoxy BLOCKED
559 page (which would only result in a "broken image" icon). There are some
560 limitations to this though. For instance, you can't just brute-force an
561 image substitution for an entire HTML page in most situations.
563 * set-image-blocker - tells Privoxy what to display in place of an ad image
564 that has hit a block rule. For this to come into play, the URL must match a
565 block action somewhere in the configuration, and, it must also match an
566 handle-as-image action.
568 The configuration options on what to display instead of the ad are:
570 pattern - a checkerboard pattern, so that an ad replacement is obvious.
573 blank - A very small empty GIF image is displayed. This is the so-called
574 "invisible" configuration option.
576 http://<URL> - A redirect to any image anywhere of the user's choosing
581 The quickest way to adjust any of these settings is with your browser through
582 the special Privoxy editor at http://config.privoxy.org/show-status (shortcut:
583 http://p.p/show-status). This is an internal page, and does not require
584 Internet access. Select the appropriate "actions" file, and click "Edit". It is
585 best to put personal or local preferences in user.action since this is not
586 meant to be overwritten during upgrades, and will over-ride the settings in
587 other files. Here you can insert new "actions", and URLs for ad blocking or
588 other purposes, and make other adjustments to the configuration. Privoxy will
589 detect these changes automatically.
591 A quick and simple step by step example:
593 * Right click on the ad image to be blocked, then select "Copy Link Location"
594 from the pop-up menu.
596 * Set your browser to http://config.privoxy.org/show-status
598 * Find user.action in the top section, and click on "Edit":
600 Figure 1. Actions Files in Use
602 [ Screenshot of Actions Files in Use ]
604 * You should have a section with only block listed under "Actions:". If not,
605 click a "Insert new section below" button, and in the new section that just
606 appeared, click the Edit button right under the word "Actions:". This will
607 bring up a list of all actions. Find block near the top, and click in the
608 "Enabled" column, then "Submit" just below the list.
610 * Now, in the block actions section, click the "Add" button, and paste the
611 URL the browser got from "Copy Link Location". Remove the http:// at the
612 beginning of the URL. Then, click "Submit" (or "OK" if in a pop-up window).
614 * Now go back to the original page, and press SHIFT-Reload (or flush all
615 browser caches). The image should be gone now.
618 This is a very crude and simple example. There might be good reasons to use a
619 wildcard pattern match to include potentially similar images from the same
620 site. For a more extensive explanation of "patterns", and the entire actions
621 concept, see the Actions section.
623 For advanced users who want to hand edit their config files, you might want to
624 now go to the Actions Files Tutorial. The ideas explained therein also apply to
625 the web-based editor.
626 -------------------------------------------------------------------------------
630 Before launching Privoxy for the first time, you will want to configure your
631 browser(s) to use Privoxy as a HTTP and HTTPS proxy. The default is 127.0.0.1
632 (or localhost) for the proxy address, and port 8118 (earlier versions used port
633 8000). This is the one configuration step that must be done!
635 Please note that Privoxy can only proxy HTTP and HTTPS traffic. It will not
636 work with FTP or other protocols.
638 Figure 2. Proxy Configuration (Mozilla)
640 [ Screenshot of Mozilla Proxy Configuration ]
642 With Netscape (and Mozilla), this can be set under:
654 For Internet Explorer:
664 Then, check "Use Proxy" and fill in the appropriate info (Address: 127.0.0.1,
665 Port: 8118). Include HTTPS (SSL), if you want HTTPS proxy support too.
667 After doing this, flush your browser's disk and memory caches to force a
668 re-reading of all pages and to get rid of any ads that may be cached. You are
669 now ready to start enjoying the benefits of using Privoxy!
671 Privoxy is typically started by specifying the main configuration file to be
672 used on the command line. If no configuration file is specified on the command
673 line, Privoxy will look for a file named config in the current directory.
674 Except on Win32 where it will try config.txt.
675 -------------------------------------------------------------------------------
677 5.1. Red Hat and Conectiva
679 We use a script. Note that Red Hat does not start Privoxy upon booting per
680 default. It will use the file /etc/privoxy/config as its main configuration
683 # /etc/rc.d/init.d/privoxy start
684 -------------------------------------------------------------------------------
688 We use a script. Note that Debian starts Privoxy upon booting per default. It
689 will use the file /etc/privoxy/config as its main configuration file.
691 # /etc/init.d/privoxy start
692 -------------------------------------------------------------------------------
696 We use a script. It will use the file /etc/privoxy/config as its main
697 configuration file. Note that SuSE starts Privoxy upon booting your PC.
700 -------------------------------------------------------------------------------
704 Click on the Privoxy Icon to start Privoxy. If no configuration file is
705 specified on the command line, Privoxy will look for a file named config.txt.
706 Note that Windows will automatically start Privoxy upon booting you PC.
707 -------------------------------------------------------------------------------
709 5.5. Solaris, NetBSD, FreeBSD, HP-UX and others
711 Example Unix startup command:
713 # /usr/sbin/privoxy /etc/privoxy/config
714 -------------------------------------------------------------------------------
718 During installation, Privoxy is configured to start automatically when the
719 system restarts. You can start it manually by double-clicking on the Privoxy
720 icon in the Privoxy folder.
721 -------------------------------------------------------------------------------
725 During installation, Privoxy is configured to start automatically when the
726 system restarts. To run Privoxy by hand, double-click on the RunPrivoxy.command
727 icon in the /Library/Privoxy folder. Or, type this command in the Terminal:
729 /Library/Privoxy/RunPrivoxy.command
732 If you are not logged in as an administrator, you will be asked for the
733 administrator password when starting Privoxy by hand.
734 -------------------------------------------------------------------------------
738 Start Privoxy (with RUN <>NIL:) in your startnet script (AmiTCP), in s:
739 user-startup (RoadShow), as startup program in your startup script (Genesis),
740 or as startup action (Miami and MiamiDx). Privoxy will automatically quit when
741 you quit your TCP/IP stack (just ignore the harmless warning your TCP/IP stack
742 may display that Privoxy is still running).
743 -------------------------------------------------------------------------------
747 A script is again used. It will use the file /etc/privoxy/config as its main
750 /etc/init.d/privoxy start
753 Note that Privoxy is not automatically started at boot time by default. You can
754 change this with the rc-update command.
756 rc-update add privoxy default
758 -------------------------------------------------------------------------------
760 5.10. Command Line Options
762 Privoxy may be invoked with the following command-line options:
766 Print version info and exit. Unix only.
770 Print short usage info and exit. Unix only.
774 Don't become a daemon, i.e. don't fork and become process group leader, and
775 don't detach from controlling tty. Unix only.
779 On startup, write the process ID to FILE. Delete the FILE on exit. Failure
780 to create or delete the FILE is non-fatal. If no FILE option is given, no
781 PID file will be used. Unix only.
783 * --user USER[.GROUP]
785 After (optionally) writing the PID file, assume the user ID of USER, and if
786 included the GID of GROUP. Exit if the privileges are not sufficient to do
791 If no configfile is included on the command line, Privoxy will look for a
792 file named "config" in the current directory (except on Win32 where it will
793 look for "config.txt" instead). Specify full path to avoid confusion. If no
794 config file is found, Privoxy will fail to start.
797 -------------------------------------------------------------------------------
798 6. Privoxy Configuration
800 All Privoxy configuration is stored in text files. These files can be edited
801 with a text editor. Many important aspects of Privoxy can also be controlled
802 easily with a web browser.
803 -------------------------------------------------------------------------------
805 6.1. Controlling Privoxy with Your Web Browser
807 Privoxy's user interface can be reached through the special URL http://
808 config.privoxy.org/ (shortcut: http://p.p/), which is a built-in page and works
809 without Internet access. You will see the following section:
811 ?? View & change the current configuration
812 ?? View the source code version numbers
813 ?? View the request headers.
814 ?? Look up which actions apply to a URL and why
815 ?? Toggle Privoxy on or off
817 This should be self-explanatory. Note the first item leads to an editor for the
818 actions files, which is where the ad, banner, cookie, and URL blocking magic is
819 configured as well as other advanced features of Privoxy. This is an easy way
820 to adjust various aspects of Privoxy configuration. The actions file, and other
821 configuration files, are explained in detail below.
823 "Toggle Privoxy On or Off" is handy for sites that might have problems with
824 your current actions and filters. You can in fact use it as a test to see
825 whether it is Privoxy causing the problem or not. Privoxy continues to run as a
826 proxy in this case, but all manipulation is disabled, i.e. Privoxy acts like a
827 normal forwarding proxy. There is even a toggle Bookmarklet offered, so that
828 you can toggle Privoxy with one click from your browser.
829 -------------------------------------------------------------------------------
831 6.2. Configuration Files Overview
833 For Unix, *BSD and Linux, all configuration files are located in /etc/privoxy/
834 by default. For MS Windows, OS/2, and AmigaOS these are all in the same
835 directory as the Privoxy executable. The name and number of configuration files
836 has changed from previous versions, and is subject to change as development
839 The installed defaults provide a reasonable starting point, though some
840 settings may be aggressive by some standards. For the time being, the principle
841 configuration files are:
843 * The main configuration file is named config on Linux, Unix, BSD, OS/2, and
844 AmigaOS and config.txt on Windows. This is a required file.
846 * default.action (the main actions file) is used to define which "actions"
847 relating to banner-blocking, images, pop-ups, content modification, cookie
848 handling etc should be applied by default. It also defines many exceptions
849 (both positive and negative) from this default set of actions that enable
850 Privoxy to selectively eliminate the junk, and only the junk, on as many
851 websites as possible.
853 Multiple actions files may be defined in config. These are processed in the
854 order they are defined. Local customizations and locally preferred
855 exceptions to the default policies as defined in default.action (which you
856 will most probably want to define sooner or later) are probably best
857 applied in user.action, where you can preserve them across upgrades.
858 standard.action is for Privoxy's internal use.
860 There is also a web based editor that can be accessed from http://
861 config.privoxy.org/show-status (Shortcut: http://p.p/show-status) for the
862 various actions files.
864 * default.filter (the filter file) can be used to re-write the raw page
865 content, including viewable text as well as embedded HTML and JavaScript,
866 and whatever else lurks on any given web page. The filtering jobs are only
867 pre-defined here; whether to apply them or not is up to the actions files.
870 All files use the "#" character to denote a comment (the rest of the line will
871 be ignored) and understand line continuation through placing a backslash ("\")
872 as the very last character in a line. If the # is preceded by a backslash, it
873 looses its special function. Placing a # in front of an otherwise valid
874 configuration line to prevent it from being interpreted is called "commenting
877 The actions files and default.filter can use Perl style regular expressions for
880 After making any changes, there is no need to restart Privoxy in order for the
881 changes to take effect. Privoxy detects such changes automatically. Note,
882 however, that it may take one or two additional requests for the change to take
883 effect. When changing the listening address of Privoxy, these "wake up"
884 requests must obviously be sent to the old listening address.
886 While under development, the configuration content is subject to change. The
887 below documentation may not be accurate by the time you read this. Also, what
888 constitutes a "default" setting, may change, so please check all your
889 configuration files on important issues.
890 -------------------------------------------------------------------------------
892 7. The Main Configuration File
894 Again, the main configuration file is named config on Linux/Unix/BSD and OS/2,
895 and config.txt on Windows. Configuration lines consist of an initial keyword
896 followed by a list of values, all separated by whitespace (any number of spaces
897 or tabs). For example:
901 Assigns the value /etc/privoxy to the option confdir and thus indicates that
902 the configuration directory is named "/etc/privoxy/".
904 All options in the config file except for confdir and logdir are optional.
905 Watch out in the below description for what happens if you leave them unset.
907 The main config file controls all aspects of Privoxy's operation that are not
908 location dependent (i.e. they apply universally, no matter where you may be
910 -------------------------------------------------------------------------------
912 7.1. Configuration and Log File Locations
914 Privoxy can (and normally does) use a number of other files for additional
915 configuration, help and logging. This section of the configuration file tells
916 Privoxy where to find those other files.
918 The user running Privoxy, must have read permission for all configuration
919 files, and write permission to any files that would be modified, such as log
920 files and actions files.
921 -------------------------------------------------------------------------------
926 The directory where the other configuration files are located
932 /etc/privoxy (Unix) or Privoxy installation dir (Windows)
938 No trailing "/", please
940 When development goes modular and multi-user, the blocker, filter, and
941 per-user config will be stored in subdirectories of "confdir". For now, the
942 configuration directory structure is flat, except for confdir/templates,
943 where the HTML templates for CGI output reside (e.g. Privoxy's 404 error
947 -------------------------------------------------------------------------------
951 The directory where all logging takes place (i.e. where logfile and jarfile
958 /var/log/privoxy (Unix) or Privoxy installation dir (Windows)
964 No trailing "/", please
967 -------------------------------------------------------------------------------
971 The actions file(s) to use
974 File name, relative to confdir, without the .action suffix
977 standard # Internal purposes, no editing recommended
978 default # Main actions file
979 user # User customizations
983 No actions are taken at all. Simple neutral proxying.
986 Multiple actionsfile lines are permitted, and are in fact recommended!
988 The default values include standard.action, which is used for internal
989 purposes and should be loaded, default.action, which is the "main" actions
990 file maintained by the developers, and user.action, where you can make your
993 Actions files are where all the per site and per URL configuration is done
994 for ad blocking, cookie management, privacy considerations, etc. There is
995 no point in using Privoxy without at least one actions file.
998 -------------------------------------------------------------------------------
1002 The filter file to use
1005 File name, relative to confdir
1008 default.filter (Unix) or default.filter.txt (Windows)
1011 No textual content filtering takes place, i.e. all +filter{name} actions in
1012 the actions files are turned neutral.
1015 The filter file contains content modification rules that use regular
1016 expressions. These rules permit powerful changes on the content of Web
1017 pages, e.g., you could disable your favorite JavaScript annoyances,
1018 re-write the actual displayed text, or just have some fun replacing
1019 "Microsoft" with "MicroSuck" wherever it appears on a Web page.
1021 The +filter{name} actions rely on the relevant filter (name) to be defined
1024 A pre-defined filter file called default.filter that contains a bunch of
1025 handy filters for common problems is included in the distribution. See the
1026 section on the filter action for a list.
1029 -------------------------------------------------------------------------------
1036 File name, relative to logdir
1039 logfile (Unix) or privoxy.log (Windows)
1042 No log file is used, all log messages go to the console (STDERR).
1045 The windows version will additionally log to the console.
1047 The logfile is where all logging and error messages are written. The level
1048 of detail and number of messages are set with the debug option (see below).
1049 The logfile can be useful for tracking down a problem with Privoxy (e.g.,
1050 it's not blocking an ad you think it should block) but in most cases you
1051 probably will never look at it.
1053 Your logfile will grow indefinitely, and you will probably want to
1054 periodically remove it. On Unix systems, you can do this with a cron job
1055 (see "man cron"). For Red Hat, a logrotate script has been included.
1057 On SuSE Linux systems, you can place a line like "/var/log/privoxy.* +1024k
1058 644 nobody.nogroup" in /etc/logfiles, with the effect that cron.daily will
1059 automatically archive, gzip, and empty the log, when it exceeds 1M size.
1061 Any log files must be writable by whatever user Privoxy is being run as
1062 (default on UNIX, user id is "privoxy").
1065 -------------------------------------------------------------------------------
1069 The file to store intercepted cookies in
1072 File name, relative to logdir
1075 jarfile (Unix) or privoxy.jar (Windows)
1078 Intercepted cookies are not stored at all.
1081 The jarfile may grow to ridiculous sizes over time.
1084 -------------------------------------------------------------------------------
1088 The trust file to use
1091 File name, relative to confdir
1094 Unset (commented out). When activated: trust (Unix) or trust.txt (Windows)
1097 The whole trust mechanism is turned off.
1100 The trust mechanism is an experimental feature for building white-lists and
1101 should be used with care. It is NOT recommended for the casual user.
1103 If you specify a trust file, Privoxy will only allow access to sites that
1104 are named in the trustfile. You can also mark sites as trusted referrers
1105 (with +), with the effect that access to untrusted sites will be granted,
1106 if a link from a trusted referrer was used. The link target will then be
1107 added to the "trustfile". Possible applications include limiting Internet
1108 access for children.
1110 If you use + operator in the trust file, it may grow considerably over
1114 -------------------------------------------------------------------------------
1115 7.2. Local Set-up Documentation
1117 If you intend to operate Privoxy for more users than just yourself, it might be
1118 a good idea to let them know how to reach you, what you block and why you do
1119 that, your policies, etc.
1120 -------------------------------------------------------------------------------
1125 Location of the Privoxy User Manual.
1128 A fully qualified URI
1134 http://www.privoxy.org/version/user-manual/ will be used, where version is
1135 the Privoxy version.
1138 The User Manual URI is used for help links from some of the internal CGI
1139 pages. The manual itself is normally packaged with the binary
1140 distributions, so you probably want to set this to a locally installed
1141 copy. For multi-user setups, you could provide a copy on a local webserver
1142 for all your users and use the corresponding URL here.
1146 Unix, in local filesystem:
1148 user-manual file:///usr/share/doc/privoxy-2.9.18/user-manual/
1150 Any platform, on local webserver (called "local-webserver"):
1152 user-manual http://local-webserver/privoxy-user-manual/
1154 +-----------------------------------------------------------------+
1156 +-----------------------------------------------------------------+
1157 |If set, this option should be the first option in the config |
1158 |file, because it is used while the config file is being read. |
1159 +-----------------------------------------------------------------+
1162 -------------------------------------------------------------------------------
1163 7.2.2. trust-info-url
1166 A URL to be displayed in the error page that users will see if access to an
1167 untrusted page is denied.
1173 Two example URL are provided
1176 No links are displayed on the "untrusted" error page.
1179 The value of this option only matters if the experimental trust mechanism
1180 has been activated. (See trustfile above.)
1182 If you use the trust mechanism, it is a good idea to write up some on-line
1183 documentation about your trust policy and to specify the URL(s) here. Use
1184 multiple times for multiple URLs.
1186 The URL(s) should be added to the trustfile as well, so users don't end up
1187 locked out from the information on why they were locked out in the first
1191 -------------------------------------------------------------------------------
1192 7.2.3. admin-address
1195 An email address to reach the proxy administrator.
1204 No email address is displayed on error pages and the CGI user interface.
1207 If both admin-address and proxy-info-url are unset, the whole "Local
1208 Privoxy Support" box on all generated pages will not be shown.
1211 -------------------------------------------------------------------------------
1212 7.2.4. proxy-info-url
1215 A URL to documentation about the local Privoxy setup, configuration or
1225 No link to local documentation is displayed on error pages and the CGI user
1229 If both admin-address and proxy-info-url are unset, the whole "Local
1230 Privoxy Support" box on all generated pages will not be shown.
1232 This URL shouldn't be blocked ;-)
1235 -------------------------------------------------------------------------------
1238 These options are mainly useful when tracing a problem. Note that you might
1239 also want to invoke Privoxy with the --no-daemon command line option when
1241 -------------------------------------------------------------------------------
1246 Key values that determine what information gets logged to the logfile.
1252 12289 (i.e.: URLs plus informational and warning messages)
1255 Nothing gets logged.
1258 The available debug levels are:
1260 debug 1 # show each GET/POST/CONNECT request
1261 debug 2 # show each connection status
1262 debug 4 # show I/O status
1263 debug 8 # show header parsing
1264 debug 16 # log all data into the logfile
1265 debug 32 # debug force feature
1266 debug 64 # debug regular expression filter
1267 debug 128 # debug fast redirects
1268 debug 256 # debug GIF de-animation
1269 debug 512 # Common Log Format
1270 debug 1024 # debug kill pop-ups
1271 debug 2048 # CGI user interface
1272 debug 4096 # Startup banner and warnings.
1273 debug 8192 # Non-fatal errors
1275 To select multiple debug levels, you can either add them or use multiple
1278 A debug level of 1 is informative because it will show you each request as
1279 it happens. 1, 4096 and 8192 are highly recommended so that you will notice
1280 when things go wrong. The other levels are probably only of interest if you
1281 are hunting down a specific problem. They can produce a hell of an output
1284 The reporting of fatal errors (i.e. ones which crash Privoxy) is always on
1285 and cannot be disabled.
1287 If you want to use CLF (Common Log Format), you should set "debug 512" ONLY
1288 and not enable anything else.
1291 -------------------------------------------------------------------------------
1292 7.3.2. single-threaded
1295 Whether to run only one server thread
1304 Multi-threaded (or, where unavailable: forked) operation, i.e. the ability
1305 to serve multiple requests simultaneously.
1308 This option is only there for debug purposes and you should never need to
1309 use it. It will drastically reduce performance.
1312 -------------------------------------------------------------------------------
1313 7.4. Access Control and Security
1315 This section of the config file controls the security-relevant aspects of
1316 Privoxy's configuration.
1317 -------------------------------------------------------------------------------
1319 7.4.1. listen-address
1322 The IP address and TCP port on which Privoxy will listen for client
1332 Bind to 127.0.0.1 (localhost), port 8118. This is suitable and recommended
1333 for home users who run Privoxy on the same machine as their browser.
1336 You will need to configure your browser(s) to this proxy address and port.
1338 If you already have another service running on port 8118, or if you want to
1339 serve requests from other machines (e.g. on your local network) as well,
1340 you will need to override the default.
1342 If you leave out the IP address, Privoxy will bind to all interfaces
1343 (addresses) on your machine and may become reachable from the Internet. In
1344 that case, consider using access control lists (ACL's, see below), and/or a
1347 If you open Privoxy to untrusted users, you will also want to turn off the
1348 enable-edit-actions and enable-remote-toggle options!
1351 Suppose you are running Privoxy on a machine which has the address
1352 192.168.0.1 on your local private network (192.168.0.0) and has another
1353 outside connection with a different address. You want it to serve requests
1356 listen-address 192.168.0.1:8118
1359 -------------------------------------------------------------------------------
1363 Initial state of "toggle" status
1372 Act as if toggled on
1375 If set to 0, Privoxy will start in "toggled off" mode, i.e. behave like a
1376 normal, content-neutral proxy where all ad blocking, filtering, etc are
1377 disabled. See enable-remote-toggle below. This is not really useful
1378 anymore, since toggling is much easier via the web interface than via
1379 editing the conf file.
1381 The windows version will only display the toggle icon in the system tray if
1382 this option is present.
1385 -------------------------------------------------------------------------------
1386 7.4.3. enable-remote-toggle
1389 Whether or not the web-based toggle feature may be used
1398 The web-based toggle feature is disabled.
1401 When toggled off, Privoxy acts like a normal, content-neutral proxy, i.e.
1402 it acts as if none of the actions applied to any URL.
1404 For the time being, access to the toggle feature can not be controlled
1405 separately by "ACLs" or HTTP authentication, so that everybody who can
1406 access Privoxy (see "ACLs" and listen-address above) can toggle it for all
1407 users. So this option is not recommended for multi-user environments with
1410 Note that you must have compiled Privoxy with support for this feature,
1411 otherwise this option has no effect.
1414 -------------------------------------------------------------------------------
1415 7.4.4. enable-edit-actions
1418 Whether or not the web-based actions file editor may be used
1427 The web-based actions file editor is disabled.
1430 For the time being, access to the editor can not be controlled separately
1431 by "ACLs" or HTTP authentication, so that everybody who can access Privoxy
1432 (see "ACLs" and listen-address above) can modify its configuration for all
1433 users. So this option is not recommended for multi-user environments with
1436 Note that you must have compiled Privoxy with support for this feature,
1437 otherwise this option has no effect.
1440 -------------------------------------------------------------------------------
1441 7.4.5. ACLs: permit-access and deny-access
1444 Who can access what.
1447 src_addr[/src_masklen] [dst_addr[/dst_masklen]]
1449 Where src_addr and dst_addr are IP addresses in dotted decimal notation or
1450 valid DNS names, and src_masklen and dst_masklen are subnet masks in CIDR
1451 notation, i.e. integer values from 2 to 30 representing the length (in
1452 bits) of the network address. The masks and the whole destination part are
1459 Don't restrict access further than implied by listen-address
1462 Access controls are included at the request of ISPs and systems
1463 administrators, and are not usually needed by individual users. For a
1464 typical home user, it will normally suffice to ensure that Privoxy only
1465 listens on the localhost (127.0.0.1) or internal (home) network address by
1466 means of the listen-address option.
1468 Please see the warnings in the FAQ that this proxy is not intended to be a
1469 substitute for a firewall or to encourage anyone to defer addressing basic
1470 security weaknesses.
1472 Multiple ACL lines are OK. If any ACLs are specified, then the Privoxy
1473 talks only to IP addresses that match at least one permit-access line and
1474 don't match any subsequent deny-access line. In other words, the last match
1475 wins, with the default being deny-access.
1477 If Privoxy is using a forwarder (see forward below) for a particular
1478 destination URL, the dst_addr that is examined is the address of the
1479 forwarder and NOT the address of the ultimate target. This is necessary
1480 because it may be impossible for the local Privoxy to determine the IP
1481 address of the ultimate target (that's often what gateways are used for).
1483 You should prefer using IP addresses over DNS names, because the address
1484 lookups take time. All DNS names must resolve! You can not use domain
1485 patterns like "*.org" or partial domain names. If a DNS name resolves to
1486 multiple IP addresses, only the first one is used.
1488 Denying access to particular sites by ACL may have undesired side effects
1489 if the site in question is hosted on a machine which also hosts other
1493 Explicitly define the default behavior if no ACL and listen-address are
1494 set: "localhost" is OK. The absence of a dst_addr implies that all
1495 destination addresses are OK:
1497 permit-access localhost
1499 Allow any host on the same class C subnet as www.privoxy.org access to
1500 nothing but www.example.com:
1502 permit-access www.privoxy.org/24 www.example.com/32
1504 Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere,
1505 with the exception that 192.168.45.73 may not access
1506 www.dirty-stuff.example.com:
1508 permit-access 192.168.45.64/26
1509 deny-access 192.168.45.73 www.dirty-stuff.example.com
1512 -------------------------------------------------------------------------------
1516 Maximum size of the buffer for content filtering.
1525 Use a 4MB (4096 KB) limit.
1528 For content filtering, i.e. the +filter and +deanimate-gif actions, it is
1529 necessary that Privoxy buffers the entire document body. This can be
1530 potentially dangerous, since a server could just keep sending data
1531 indefinitely and wait for your RAM to exhaust -- with nasty consequences.
1534 When a document buffer size reaches the buffer-limit, it is flushed to the
1535 client unfiltered and no further attempt to filter the rest of the document
1536 is made. Remember that there may be multiple threads running, which might
1537 require up to buffer-limit Kbytes each, unless you have enabled
1538 "single-threaded" above.
1541 -------------------------------------------------------------------------------
1544 This feature allows routing of HTTP requests through a chain of multiple
1545 proxies. It can be used to better protect privacy and confidentiality when
1546 accessing specific domains by routing requests to those domains through an
1547 anonymous public proxy (see e.g. http://www.multiproxy.org/anon_list.htm) Or to
1548 use a caching proxy to speed up browsing. Or chaining to a parent proxy may be
1549 necessary because the machine that Privoxy runs on has no direct Internet
1552 Also specified here are SOCKS proxies. Privoxy supports the SOCKS 4 and SOCKS
1554 -------------------------------------------------------------------------------
1559 To which parent HTTP proxy specific requests should be routed.
1562 target_pattern http_parent[:port]
1564 where target_pattern is a URL pattern that specifies to which requests
1565 (i.e. URLs) this forward rule shall apply. Use / to denote "all URLs".
1566 http_parent[:port] is the DNS name or IP address of the parent HTTP proxy
1567 through which the requests should be forwarded, optionally followed by its
1568 listening port (default: 8080). Use a single dot (.) to denote "no
1575 Don't use parent HTTP proxies.
1578 If http_parent is ".", then requests are not forwarded to another HTTP
1579 proxy but are made directly to the web servers.
1581 Multiple lines are OK, they are checked in sequence, and the last match
1585 Everything goes to an example anonymizing proxy, except SSL on port 443
1586 (which it doesn't handle):
1588 forward / anon-proxy.example.org:8080
1591 Everything goes to our example ISP's caching proxy, except for requests to
1594 forward / caching-proxy.example-isp.net:8000
1595 forward .example-isp.net .
1598 -------------------------------------------------------------------------------
1599 7.5.2. forward-socks4 and forward-socks4a
1602 Through which SOCKS proxy (and to which parent HTTP proxy) specific
1603 requests should be routed.
1606 target_pattern socks_proxy[:port] http_parent[:port]
1608 where target_pattern is a URL pattern that specifies to which requests
1609 (i.e. URLs) this forward rule shall apply. Use / to denote "all URLs".
1610 http_parent and socks_proxy are IP addresses in dotted decimal notation or
1611 valid DNS names (http_parent may be "." to denote "no HTTP forwarding"),
1612 and the optional port parameters are TCP ports, i.e. integer values from 1
1619 Don't use SOCKS proxies.
1622 Multiple lines are OK, they are checked in sequence, and the last match
1625 The difference between forward-socks4 and forward-socks4a is that in the
1626 SOCKS 4A protocol, the DNS resolution of the target hostname happens on the
1627 SOCKS server, while in SOCKS 4 it happens locally.
1629 If http_parent is ".", then requests are not forwarded to another HTTP
1630 proxy but are made (HTTP-wise) directly to the web servers, albeit through
1634 From the company example.com, direct connections are made to all "internal"
1635 domains, but everything outbound goes through their ISP's proxy by way of
1636 example.com's corporate SOCKS 4A gateway to the Internet.
1638 forward-socks4a / socks-gw.example.com:1080 www-cache.example-isp.net:8080
1639 forward .example.com .
1641 A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent
1644 forward-socks4 / socks-gw.example.com:1080 .
1647 -------------------------------------------------------------------------------
1648 7.5.3. Advanced Forwarding Examples
1650 If you have links to multiple ISPs that provide various special content only to
1651 their subscribers, you can configure multiple Privoxies which have connections
1652 to the respective ISPs to act as forwarders to each other, so that your users
1653 can see the internal content of all ISPs.
1655 Assume that host-a has a PPP connection to isp-a.net. And host-b has a PPP
1656 connection to isp-b.net. Both run Privoxy. Their forwarding configuration can
1662 forward .isp-b.net host-b:8118
1667 forward .isp-a.net host-a:8118
1669 Now, your users can set their browser's proxy to use either host-a or host-b
1670 and be able to browse the internal content of both isp-a and isp-b.
1672 If you intend to chain Privoxy and squid locally, then chain as browser ->
1673 squid -> privoxy is the recommended way.
1675 Assuming that Privoxy and squid run on the same box, your squid configuration
1676 could then look like this:
1678 # Define Privoxy as parent proxy (without ICP)
1679 cache_peer 127.0.0.1 parent 8118 7 no-query
1681 # Define ACL for protocol FTP
1684 # Do not forward FTP requests to Privoxy
1685 always_direct allow ftp
1687 # Forward all the rest to Privoxy
1688 never_direct allow all
1690 You would then need to change your browser's proxy settings to squid's address
1691 and port. Squid normally uses port 3128. If unsure consult http_port in
1694 You could just as well decide to only forward requests for Windows executables
1695 through a virus-scanning parent proxy, say, on antivir.example.com, port 8010:
1698 forward /.*\.(exe|com|dll|zip)$ antivir.example.com:8010
1699 -------------------------------------------------------------------------------
1701 7.6. Windows GUI Options
1703 Privoxy has a number of options specific to the Windows GUI interface:
1706 If "activity-animation" is set to 1, the Privoxy icon will animate when
1707 "Privoxy" is active. To turn off, set to 0.
1709 activity-animation 1
1713 If "log-messages" is set to 1, Privoxy will log messages to the console window:
1719 If "log-buffer-size" is set to 1, the size of the log buffer, i.e. the amount
1720 of memory used for the log messages displayed in the console window, will be
1721 limited to "log-max-lines" (see below).
1723 Warning: Setting this to 0 will result in the buffer to grow infinitely and eat
1730 log-max-lines is the maximum number of lines held in the log buffer. See above.
1736 If "log-highlight-messages" is set to 1, Privoxy will highlight portions of the
1737 log messages with a bold-faced font:
1739 log-highlight-messages 1
1743 The font used in the console window:
1745 log-font-name Comic Sans MS
1749 Font size used in the console window:
1755 "show-on-task-bar" controls whether or not Privoxy will appear as a button on
1756 the Task bar when minimized:
1762 If "close-button-minimizes" is set to 1, the Windows close button will minimize
1763 Privoxy instead of closing the program (close with the exit option on the File
1766 close-button-minimizes 1
1770 The "hide-console" option is specific to the MS-Win console version of Privoxy.
1771 If this option is used, Privoxy will disconnect from and hide the command
1776 -------------------------------------------------------------------------------
1780 The actions files are used to define what actions Privoxy takes for which URLs,
1781 and thus determine how ad images, cookies and various other aspects of HTTP
1782 content and transactions are handled, and on which sites (or even parts
1783 thereof). There are three such files included with Privoxy (as of version
1784 2.9.15), with differing purposes:
1786 * default.action - is the primary action file that sets the initial values
1787 for all actions. It is intended to provide a base level of functionality
1788 for Privoxy's array of features. So it is a set of broad rules that should
1789 work reasonably well for users everywhere. This is the file that the
1790 developers are keeping updated, and making available to users.
1792 * user.action - is intended to be for local site preferences and exceptions.
1793 As an example, if your ISP or your bank has specific requirements, and need
1794 special handling, this kind of thing should go here. This file will not be
1797 * standard.action - is used by the web based editor, to set various
1798 pre-defined sets of rules for the default actions section in
1799 default.action. These have increasing levels of aggressiveness and have no
1800 influence on your browsing unless you select them explicitly in the editor.
1801 It is not recommend to edit this file.
1804 The list of actions files to be used are defined in the main configuration
1805 file, and are processed in the order they are defined. The content of these can
1806 all be viewed and edited from http://config.privoxy.org/show-status.
1808 An actions file typically has multiple sections. If you want to use "aliases"
1809 in an actions file, you have to place the (optional) alias section at the top
1810 of that file. Then comes the default set of rules which will apply universally
1811 to all sites and pages (be very careful with using such a universal set in
1812 user.action or any other actions file after default.action, because it will
1813 override the result from consulting any previous file). And then below that,
1814 exceptions to the defined universal policies. You can regard user.action as an
1815 appendix to default.action, with the advantage that is a separate file, which
1816 makes preserving your personal settings across Privoxy upgrades easier.
1818 Actions can be used to block anything you want, including ads, banners, or just
1819 some obnoxious URL that you would rather not see. Cookies can be accepted or
1820 rejected, or accepted only during the current browser session (i.e. not written
1821 to disk), content can be modified, JavaScripts tamed, user-tracking fooled, and
1822 much more. See below for a complete list of actions.
1823 -------------------------------------------------------------------------------
1825 8.1. Finding the Right Mix
1827 Note that some actions, like cookie suppression or script disabling, may render
1828 some sites unusable that rely on these techniques to work properly. Finding the
1829 right mix of actions is not always easy and certainly a matter of personal
1830 taste. In general, it can be said that the more "aggressive" your default
1831 settings (in the top section of the actions file) are, the more exceptions for
1832 "trusted" sites you will have to make later. If, for example, you want to kill
1833 popup windows per default, you'll have to make exceptions from that rule for
1834 sites that you regularly use and that require popups for actually useful
1835 content, like maybe your bank, favorite shop, or newspaper.
1837 We have tried to provide you with reasonable rules to start from in the
1838 distribution actions files. But there is no general rule of thumb on these
1839 things. There just are too many variables, and sites are constantly changing.
1840 Sooner or later you will want to change the rules (and read this chapter again
1842 -------------------------------------------------------------------------------
1846 The easiest way to edit the actions files is with a browser by using our
1847 browser-based editor, which can be reached from http://config.privoxy.org/
1848 show-status. The editor allows both fine-grained control over every single
1849 feature on a per-URL basis, and easy choosing from wholesale sets of defaults
1850 like "Cautious", "Medium" or "Advanced".
1852 If you prefer plain text editing to GUIs, you can of course also directly edit
1853 the the actions files. Look at default.action which is richly commented.
1854 -------------------------------------------------------------------------------
1856 8.3. How Actions are Applied to URLs
1858 Actions files are divided into sections. There are special sections, like the "
1859 alias" sections which will be discussed later. For now let's concentrate on
1860 regular sections: They have a heading line (often split up to multiple lines
1861 for readability) which consist of a list of actions, separated by whitespace
1862 and enclosed in curly braces. Below that, there is a list of URL patterns, each
1865 To determine which actions apply to a request, the URL of the request is
1866 compared to all patterns in each action file file. Every time it matches, the
1867 list of applicable actions for the URL is incrementally updated, using the
1868 heading of the section in which the pattern is located. If multiple matches for
1869 the same URL set the same action differently, the last match wins. If not, the
1870 effects are aggregated. E.g. a URL might match a regular section with a heading
1871 line of { +handle-as-image }, then later another one with just { +block },
1872 resulting in both actions to apply.
1874 You can trace this process for any given URL by visiting http://
1875 config.privoxy.org/show-url-info.
1877 More detail on this is provided in the Appendix, Anatomy of an Action.
1878 -------------------------------------------------------------------------------
1882 Generally, a pattern has the form <domain>/<path>, where both the <domain> and
1883 <path> are optional. (This is why the pattern / matches all URLs).
1886 is a domain-only pattern and will match any request to www.example.com,
1887 regardless of which document on that server is requested.
1890 means exactly the same. For domain-only patterns, the trailing / may be
1893 www.example.com/index.html
1894 matches only the single document /index.html on www.example.com.
1897 matches the document /index.html, regardless of the domain, i.e. on any web
1901 matches nothing, since it would be interpreted as a domain name and there
1902 is no top-level domain called .html.
1905 -------------------------------------------------------------------------------
1906 8.4.1. The Domain Pattern
1908 The matching of the domain part offers some flexible options: if the domain
1909 starts or ends with a dot, it becomes unanchored at that end. For example:
1912 matches any domain that ENDS in .example.com
1915 matches any domain that STARTS with www.
1918 matches any domain that CONTAINS .example. (Correctly speaking: It matches
1919 any FQDN that contains example as a domain.)
1922 Additionally, there are wild-cards that you can use in the domain names
1923 themselves. They work pretty similar to shell wild-cards: "*" stands for zero
1924 or more arbitrary characters, "?" stands for any single character, you can
1925 define character classes in square brackets and all of that can be freely
1929 matches "adserver.example.com", "ads.example.com", etc but not
1933 matches all of the above, and then some.
1936 matches www.ipix.com, pictures.epix.com, a.b.c.d.e.upix.com etc.
1938 www[1-9a-ez].example.c*
1939 matches www1.example.com, www4.example.cc, wwwd.example.cy,
1940 wwwz.example.com etc., but not wwww.example.com.
1943 -------------------------------------------------------------------------------
1944 8.4.2. The Path Pattern
1946 Privoxy uses Perl compatible regular expressions (through the PCRE library) for
1949 There is an Appendix with a brief quick-start into regular expressions, and
1950 full (very technical) documentation on PCRE regex syntax is available on-line
1951 at http://www.pcre.org/man.txt. You might also find the Perl man page on
1952 regular expressions (man perlre) useful, which is available on-line at http://
1953 www.perldoc.com/perl5.6/pod/perlre.html.
1955 Note that the path pattern is automatically left-anchored at the "/", i.e. it
1956 matches as if it would start with a "^" (regular expression speak for the
1957 beginning of a line).
1959 Please also note that matching in the path is CASE INSENSITIVE by default, but
1960 you can switch to case sensitive at any point in the pattern by using the "(?
1961 -i)" switch: www.example.com/(?-i)PaTtErN.* will match only documents whose
1962 path starts with PaTtErN in exactly this capitalization.
1963 -------------------------------------------------------------------------------
1967 All actions are disabled by default, until they are explicitly enabled
1968 somewhere in an actions file. Actions are turned on if preceded with a "+", and
1969 turned off if preceded with a "-". So a +action means "do that action", e.g.
1970 +block means "please block URLs that match the following patterns", and -block
1971 means "don't block URLs that match the following patterns, even if +block
1972 previously applied."
1974 Again, actions are invoked by placing them on a line, enclosed in curly braces
1975 and separated by whitespace, like in {+some-action -some-other-action
1976 {some-parameter}}, followed by a list of URL patterns, one per line, to which
1977 they apply. Together, the actions line and the following pattern lines make up
1978 a section of the actions file.
1980 There are three classes of actions:
1982 * Boolean, i.e the action can only be "enabled" or "disabled". Syntax:
1984 +name # enable action name
1985 -name # disable action name
1989 * Parameterized, where some value is required in order to enable this type of
1992 +name{param} # enable action and set parameter to param,
1993 # overwriting parameter from previous match if necessary
1994 -name # disable action. The parameter can be omitted
1996 Note that if the URL matches multiple positive forms of a parameterized
1997 action, the last match wins, i.e. the params from earlier matches are
2000 Example: +hide-user-agent{ Mozilla 1.0 }
2002 * Multi-value. These look exactly like parameterized actions, but they behave
2003 differently: If the action applies multiple times to the same URL, but with
2004 different parameters, all the parameters from all matches are remembered.
2005 This is used for actions that can be executed for the same request
2006 repeatedly, like adding multiple headers, or filtering through multiple
2009 +name{param} # enable action and add param to the list of parameters
2010 -name{param} # remove the parameter param from the list of parameters
2011 # If it was the last one left, disable the action.
2012 -name # disable this action completely and remove all parameters from the list
2014 Examples: +add-header{X-Fun-Header: Some text} and +filter{html-annoyances}
2017 If nothing is specified in any actions file, no "actions" are taken. So in this
2018 case Privoxy would just be a normal, non-blocking, non-anonymizing proxy. You
2019 must specifically enable the privacy and blocking features you need (although
2020 the provided default actions files will give a good starting point).
2022 Later defined actions always over-ride earlier ones. So exceptions to any rules
2023 you make, should come in the latter part of the file (or in a file that is
2024 processed later when using multiple actions files). For multi-valued actions,
2025 the actions are applied in the order they are specified. Actions files are
2026 processed in the order they are defined in config (the default installation has
2027 three actions files). It also quite possible for any given URL pattern to match
2028 more than one pattern and thus more than one set of actions!
2030 The list of valid Privoxy actions are:
2031 -------------------------------------------------------------------------------
2036 Confuse log analysis, custom applications
2039 Sends a user defined HTTP header to the web server.
2045 Any string value is possible. Validity of the defined HTTP headers is not
2046 checked. It is recommended that you use the "X-" prefix for custom headers.
2049 This action may be specified multiple times, in order to define multiple
2050 headers. This is rarely needed for the typical user. If you don't know what
2051 "HTTP headers" are, you definitely don't need to worry about this one.
2054 +add-header{X-User-Tracking: sucks}
2057 -------------------------------------------------------------------------------
2061 Block ads or other obnoxious content
2064 Requests for URLs to which this action applies are blocked, i.e. the
2065 requests are not forwarded to the remote server, but answered locally with
2066 a substitute page or image, as determined by the handle-as-image and
2067 set-image-blocker actions.
2076 Privoxy sends a special "BLOCKED" page for requests to blocked pages. This
2077 page contains links to find out why the request was blocked, and a
2078 click-through to the blocked content (the latter only if compiled with the
2079 force feature enabled). The "BLOCKED" page adapts to the available screen
2080 space -- it displays full-blown if space allows, or miniaturized and
2081 text-only if loaded into a small frame or window. If you are using Privoxy
2082 right now, you can take a look at the "BLOCKED" page.
2084 A very important exception occurs if both block and handle-as-image, apply
2085 to the same request: it will then be replaced by an image. If
2086 set-image-blocker (see below) also applies, the type of image will be
2087 determined by its parameter, if not, the standard checkerboard pattern is
2090 It is important to understand this process, in order to understand how
2091 Privoxy deals with ads and other unwanted content.
2093 The filter action can perform a very similar task, by "blocking" banner
2094 images and other content through rewriting the relevant URLs in the
2095 document's HTML source, so they don't get requested in the first place.
2096 Note that this is a totally different technique, and it's easy to confuse
2099 Example usage (section):
2100 {+block} # Block and replace with "blocked" page
2101 .nasty-stuff.example.com
2103 {+block +handle-as-image} # Block and replace with image
2108 -------------------------------------------------------------------------------
2109 8.5.3. crunch-incoming-cookies
2112 Prevent the web server from setting any cookies on your system
2115 Deletes any "Set-Cookie:" HTTP headers from server replies.
2124 This action is only concerned with incoming cookies. For outgoing cookies,
2125 use crunch-outgoing-cookies. Use both to disable cookies completely.
2127 It makes no sense at all to use this action in conjunction with the
2128 session-cookies-only action, since it would prevent the session cookies
2132 +crunch-incoming-cookies
2135 -------------------------------------------------------------------------------
2136 8.5.4. crunch-outgoing-cookies
2139 Prevent the web server from reading any cookies from your system
2142 Deletes any "Cookie:" HTTP headers from client requests.
2151 This action is only concerned with outgoing cookies. For incoming cookies,
2152 use crunch-incoming-cookies. Use both to disable cookies completely.
2154 It makes no sense at all to use this action in conjunction with the
2155 session-cookies-only action, since it would prevent the session cookies
2159 +crunch-outgoing-cookies
2162 -------------------------------------------------------------------------------
2163 8.5.5. deanimate-gifs
2166 Stop those annoying, distracting animated GIF images.
2169 De-animate GIF animations, i.e. reduce them to their first or last image.
2178 This will also shrink the images considerably (in bytes, not pixels!). If
2179 the option "first" is given, the first frame of the animation is used as
2180 the replacement. If "last" is given, the last frame of the animation is
2181 used instead, which probably makes more sense for most banner animations,
2182 but also has the risk of not showing the entire last frame (if it is only a
2183 delta to an earlier frame).
2185 You can safely use this action with patterns that will also match non-GIF
2186 objects, because no attempt will be made at anything that doesn't look like
2190 +deanimate-gifs{last}
2193 -------------------------------------------------------------------------------
2194 8.5.6. downgrade-http-version
2197 Work around (very rare) problems with HTTP/1.1
2200 Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0.
2209 This is a left-over from the time when Privoxy didn't support important
2210 HTTP/1.1 features well. It is left here for the unlikely case that you
2211 experience HTTP/1.1 related problems with some server out there. Not all
2212 (optional) HTTP/1.1 features are supported yet, so there is a chance you
2213 might need this action.
2215 Example usage (section):
2216 {+downgrade-http-version}
2217 problem-host.example.com
2220 -------------------------------------------------------------------------------
2221 8.5.7. fast-redirects
2224 Fool some click-tracking scripts and speed up indirect links
2227 Cut off all but the last valid URL from requests.
2236 Many sites, like yahoo.com, don't just link to other sites. Instead, they
2237 will link to some script on their own servers, giving the destination as a
2238 parameter, which will then redirect you to the final target. URLs resulting
2239 from this scheme typically look like: http://some.place/click-tracker.cgi?
2240 target=http://some.where.else.
2242 Sometimes, there are even multiple consecutive redirects encoded in the
2243 URL. These redirections via scripts make your web browsing more traceable,
2244 since the server from which you follow such a link can see where you go to.
2245 Apart from that, valuable bandwidth and time is wasted, while your browser
2246 ask the server for one redirect after the other. Plus, it feeds the
2249 This feature is currently not very smart and is scheduled for improvement.
2250 It is likely to break some sites. You should expect to need possibly many
2251 exceptions to this action, if it is enabled by default in default.action.
2252 Some sites just don't work without it.
2258 -------------------------------------------------------------------------------
2262 Get rid of HTML and JavaScript annoyances, banner advertisements (by size),
2263 do fun text replacements, etc.
2266 Text documents, including HTML and JavaScript, to which this action
2267 applies, are filtered on-the-fly through the specified regular expression
2268 based substitutions.
2274 The name of a filter, as defined in the filter file (typically
2275 default.filter, set by the filterfile option in the config file). Filtering
2276 can be completely disabled without the use of parameters.
2279 For your convenience, there are a number of pre-defined filters available
2280 in the distribution filter file that you can use. See the examples below
2283 This is potentially a very powerful feature! But "rolling your own" filters
2284 requires a knowledge of regular expressions and HTML.
2286 Filtering requires buffering the page content, which may appear to slow
2287 down page rendering since nothing is displayed until all content has passed
2288 the filters. (It does not really take longer, but seems that way since the
2289 page is not incrementally displayed.) This effect will be more noticeable
2290 on slower connections.
2292 The amount of data that can be filtered is limited to the buffer-limit
2293 option in the main config file. The default is 4096 KB (4 Megs). Once this
2294 limit is exceeded, the buffered data, and all pending data, is passed
2295 through unfiltered. Inappropriate MIME types are not filtered.
2297 At this time, Privoxy cannot (yet!) uncompress compressed documents. If you
2298 want filtering to work on all documents, even those that would normally be
2299 sent compressed, use the prevent-compression action in conjunction with
2302 Filtering can achieve some of the same effects as the block action, i.e. it
2303 can be used to block ads and banners. But the mechanism works quite
2304 differently. One effective use, is to block ad banners based on their size
2305 (see below), since many of these seem to be somewhat standardized.
2307 Feedback with suggestions for new or improved filters is particularly
2310 Example usage (with filters from the distribution default.filter file):
2311 +filter{html-annoyances} # Get rid of particularly annoying HTML abuse.
2313 +filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse
2315 +filter{banners-by-size} # Kill banners based on their size for this page (very efficient!)
2317 +filter{banners-by-link} # Kill banners based on the link they are contained in (experimental)
2319 +filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective
2321 +filter{content-cookies} # Kill cookies that come sneaking in the HTML or JS content
2323 +filter{popups} # Kill all popups in JS and HTML
2325 +filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking)
2327 +filter{fun} # Text replacements for subversive browsing fun!
2329 +filter{frameset-borders} # Give frames a border and make them resizeable
2331 +filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups)
2333 +filter{nimda} # Remove Nimda (virus) code.
2335 +filter{shockwave-flash} # Kill embedded Shockwave Flash objects
2337 +filter{crude-parental} # Kill all web pages that contain the words "sex" or "warez"
2339 +filter{js-events} # Kill all JS event bindings (Radically destructive! Only for extra nasty sites)
2342 -------------------------------------------------------------------------------
2343 8.5.9. handle-as-image
2346 Mark URLs as belonging to images (so they'll be replaced by images if they
2350 This action alone doesn't do anything noticeable. It just marks URLs as
2351 images. If the block action also applies, the presence or absence of this
2352 mark decides whether an HTML "blocked" page, or a replacement image (as
2353 determined by the set-image-blocker action) will be sent to the client as a
2354 substitute for the blocked content.
2363 The below generic example section is actually part of default.action. It
2364 marks all URLs with well-known image file name extensions as images and
2365 should be left intact.
2367 Users will probably only want to use the handle-as-image action in
2368 conjunction with block, to block sources of banners, whose URLs don't
2369 reflect the file type, like in the second example section.
2371 Note that you cannot treat HTML pages as images in most cases. For
2372 instance, (in-line) ad frames require an HTML page to be sent, or they
2373 won't display properly. Forcing handle-as-image in this situation will not
2374 replace the ad frame with an image, but lead to error messages.
2376 Example usage (sections):
2377 # Generic image extensions:
2380 /.*\.(gif|jpg|jpeg|png|bmp|ico)$
2382 # These don't look like images, but they're banners and should be
2383 # blocked as images:
2385 {+block +handle-as-image}
2386 some.nasty-banner-server.com/junk.cgi?output=trash
2388 # Banner source! Who cares if they also have non-image content?
2392 -------------------------------------------------------------------------------
2393 8.5.10. hide-forwarded-for-headers
2396 Improve privacy by hiding the true source of the request
2399 Deletes any existing "X-Forwarded-for:" HTTP header from client requests,
2400 and prevents adding a new one.
2409 It is fairly safe to leave this on.
2411 This action is scheduled for improvement: It should be able to generate
2412 forged "X-Forwarded-for:" headers using random IP addresses from a
2413 specified network, to make successive requests from the same client look
2414 like requests from a pool of different users sharing the same proxy.
2417 +hide-forwarded-for-headers
2420 -------------------------------------------------------------------------------
2421 8.5.11. hide-from-header
2424 Keep your (old and ill) browser from telling web servers your email address
2427 Deletes any existing "From:" HTTP header, or replaces it with the specified
2434 Keyword: "block", or any user defined value.
2437 The keyword "block" will completely remove the header (not to be confused
2438 with the block action).
2440 Alternately, you can specify any value you prefer to be sent to the web
2441 server. If you do, it is a matter of fairness not to use any address that
2442 is actually used by a real person.
2444 This action is rarely needed, as modern web browsers don't send "From:"
2448 +hide-from-header{block}
2450 +hide-from-header{spam-me-senseless@sittingduck.example.com}
2453 -------------------------------------------------------------------------------
2454 8.5.12. hide-referrer
2457 Conceal which link you followed to get to a particular site
2460 Deletes the "Referer:" (sic) HTTP header from the client request, or
2461 replaces it with a forged one.
2467 + "block" to delete the header completely.
2469 + "forge" to pretend to be coming from the homepage of the server we are
2472 + Any other string to set a user defined referrer.
2476 "forge" is the preferred option here, since some servers will not send
2477 images back otherwise, in an attempt to prevent their valuable content from
2478 being embedded elsewhere (and hence, without being surrounded by their
2481 hide-referer is an alternate spelling of hide-referrer and the two can be
2482 can be freely substituted with each other. ("referrer" is the correct
2483 English spelling, however the HTTP specification has a bug - it requires it
2484 to be spelled as "referer".)
2487 +hide-referrer{forge}
2489 +hide-referrer{http://www.yahoo.com/}
2492 -------------------------------------------------------------------------------
2493 8.5.13. hide-user-agent
2496 Conceal your type of browser and client operating system
2499 Replaces the value of the "User-Agent:" HTTP header in client requests with
2500 the specified value.
2506 Any user-defined string.
2509 +-----------------------------------------------------------------+
2511 +-----------------------------------------------------------------+
2512 |This breaks many web sites that depend on looking at this header |
2513 |in order to customize their content for different browsers |
2514 |(which, by the way, is NOT a smart way to do that!). |
2515 +-----------------------------------------------------------------+
2517 Using this action in multi-user setups or wherever different types of
2518 browsers will access the same Privoxy is not recommended. In single-user,
2519 single-browser setups, you might use it to delete your OS version
2520 information from the headers, because it is an invitation to exploit known
2521 bugs for your OS. It is also occasionally useful to forge this in order to
2522 access sites that won't let you in otherwise (though there may be a good
2523 reason in some cases). Example of this: some MSN sites will not let Mozilla
2524 enter, yet forging to a Netscape 6.1 user-agent works just fine. (Must be
2525 just a silly MS goof, I'm sure :-).
2527 This action is scheduled for improvement.
2530 +hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}
2533 -------------------------------------------------------------------------------
2537 Eliminate those annoying pop-up windows
2540 While loading the document, replace JavaScript code that opens pop-up
2541 windows with (syntactically neutral) dummy code on the fly.
2550 This action is easily confused with the built-in, hardwired filter action,
2551 but there are important differences: For kill-popups, the document need not
2552 be buffered, so it can be incrementally rendered while downloading. But
2553 kill-popups doesn't catch as many pop-ups as filter{popups} does.
2555 Think of it as a fast and efficient replacement for a filter that you can
2556 use if you don't want any filtering at all. Note that it doesn't make sense
2557 to combine it with any filter action, since as soon as one filter applies,
2558 the whole document needs to be buffered anyway, which destroys the
2559 advantage of the kill-popups action over its filter equivalent.
2561 Killing all pop-ups is a dangerous business. Many shops and banks rely on
2562 pop-ups to display forms, shopping carts etc, and killing only the unwanted
2563 pop-ups would require artificial intelligence in Privoxy. If the only kind
2564 of pop-ups that you want to kill are exit consoles (those really nasty
2565 windows that appear when you close an other one), you might want to use
2566 filter{js-annoyances} instead.
2572 -------------------------------------------------------------------------------
2573 8.5.15. limit-connect
2576 Prevent abuse of Privoxy as a TCP proxy relay
2579 Specifies to which ports HTTP CONNECT requests are allowable.
2585 A comma-separated list of ports or port ranges (the latter using dashes,
2586 with the minimum defaulting to 0 and the maximum to 65K).
2589 By default, i.e. if no limit-connect action applies, Privoxy only allows
2590 HTTP CONNECT requests to port 443 (the standard, secure HTTPS port). Use
2591 limit-connect if more fine-grained control is desired for some or all
2594 The CONNECT methods exists in HTTP to allow access to secure websites (
2595 "https://" URLs) through proxies. It works very simply: the proxy connects
2596 to the server on the specified port, and then short-circuits its
2597 connections to the client and to the remote server. This can be a big
2598 security hole, since CONNECT-enabled proxies can be abused as TCP relays
2601 If you don't know what any of this means, there probably is no reason to
2602 change this one, since the default is already very restrictive.
2605 +limit-connect{443} # This is the default and need not be specified.
2606 +limit-connect{80,443} # Ports 80 and 443 are OK.
2607 +limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
2608 +limit-connect{-} # All ports are OK (gaping security hole!)
2611 -------------------------------------------------------------------------------
2612 8.5.16. prevent-compression
2615 Ensure that servers send the content uncompressed, so it can be passed
2619 Adds a header to the request that asks for uncompressed transfer.
2628 More and more websites send their content compressed by default, which is
2629 generally a good idea and saves bandwidth. But for the filter,
2630 deanimate-gifs and kill-popups actions to work, Privoxy needs access to the
2631 uncompressed data. Unfortunately, Privoxy can't yet(!) uncompress, filter,
2632 and re-compress the content on the fly. So if you want to ensure that all
2633 websites, including those that normally compress, can be filtered, you need
2636 This will slow down transfers from those websites, though. If you use any
2637 of the above-mentioned actions, you will typically want to use
2638 prevent-compression in conjunction with them.
2640 Note that some (rare) ill-configured sites don't handle requests for
2641 uncompressed documents correctly (they send an empty document body). If you
2642 use prevent-compression per default, you'll have to add exceptions for
2643 those sites. See the example for how to do that.
2645 Example usage (sections):
2648 {+prevent-compression}
2651 # Make exceptions for ill sites:
2653 {-prevent-compression}
2655 www.pclinuxonline.com
2658 -------------------------------------------------------------------------------
2659 8.5.17. send-vanilla-wafer
2662 Feed log analysis scripts with useless data.
2665 Sends a cookie with each request stating that you do not accept any
2666 copyright on cookies sent to you, and asking the site operator not to track
2676 The vanilla wafer is a (relatively) unique header and could conceivably be
2679 This action is rarely used and not enabled in the default configuration.
2685 -------------------------------------------------------------------------------
2689 Send custom cookies or feed log analysis scripts with even more useless
2693 Sends a custom, user-defined cookie with each request.
2699 A string of the form "name=value".
2702 Being multi-valued, multiple instances of this action can apply to the same
2703 request, resulting in multiple cookies being sent.
2705 This action is rarely used and not enabled in the default configuration.
2707 Example usage (section):
2708 {+send-wafer{UsingPrivoxy=true}}
2709 my-internal-testing-server.void
2712 -------------------------------------------------------------------------------
2713 8.5.19. session-cookies-only
2716 Allow only temporary "session" cookies (for the current browser session
2720 Deletes the "expires" field from "Set-Cookie:" server headers. Most
2721 browsers will not store such cookies permanently and forget them in between
2731 This is less strict than crunch-incoming-cookies / crunch-outgoing-cookies
2732 and allows you to browse websites that insist or rely on setting cookies,
2733 without compromising your privacy too badly.
2735 Most browsers will not permanently store cookies that have been processed
2736 by session-cookies-only and will forget about them between sessions. This
2737 makes profiling cookies useless, but won't break sites which require
2738 cookies so that you can log in for transactions. This is generally turned
2739 on for all sites, and is the recommended setting.
2741 It makes no sense at all to use session-cookies-only together with
2742 crunch-incoming-cookies or crunch-outgoing-cookies. If you do, cookies will
2745 Note that it is up to the browser how it handles such cookies without an
2746 "expires" field. If you use an exotic browser, you might want to try it out
2750 +session-cookies-only
2753 -------------------------------------------------------------------------------
2754 8.5.20. set-image-blocker
2757 Choose the replacement for blocked images
2760 This action alone doesn't do anything noticeable. If both block and
2761 handle-as-image also apply, i.e. if the request is to be blocked as an
2762 image, then the parameter of this action decides what will be sent as a
2769 + "pattern" to send a built-in checkerboard pattern image. The image is
2770 visually decent, scales very well, and makes it obvious where banners
2773 + "blank" to send a built-in transparent image. This makes banners
2774 disappear completely, but makes it hard to detect where Privoxy has
2775 blocked images on a given page and complicates troubleshooting if
2776 Privoxy has blocked innocent images, like navigation icons.
2778 + "target-url" to send a redirect to target-url. You can redirect to any
2779 image anywhere, even in your local filesystem (via "file:///" URL).
2781 A good application of redirects is to use special Privoxy-built-in
2782 URLs, which send the built-in images, as target-url. This has the same
2783 visual effect as specifying "blank" or "pattern" in the first place,
2784 but enables your browser to cache the replacement image, instead of
2785 requesting it over and over again.
2789 The URLs for the built-in images are "http://config.privoxy.org/
2790 send-banner?type=type", where type is either "blank" or "pattern".
2792 There is a third (advanced) type, called "auto". It is NOT to be used in
2793 set-image-blocker, but meant for use from filters. Auto will select the
2794 type of image that would have applied to the referring page, had it been an
2800 +set-image-blocker{pattern}
2802 Redirect to the BSD devil:
2804 +set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}
2806 Redirect to the built-in pattern for better caching:
2808 +set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}
2811 -------------------------------------------------------------------------------
2814 Note that many of these actions have the potential to cause a page to
2815 misbehave, possibly even not to display at all. There are many ways a site
2816 designer may choose to design his site, and what HTTP header content, and other
2817 criteria, he may depend on. There is no way to have hard and fast rules for all
2818 sites. See the Appendix for a brief example on troubleshooting actions.
2819 -------------------------------------------------------------------------------
2823 Custom "actions", known to Privoxy as "aliases", can be defined by combining
2824 other actions. These can in turn be invoked just like the built-in actions.
2825 Currently, an alias name can contain any character except space, tab, "=", "{"
2826 and "}", but we strongly recommend that you only use "a" to "z", "0" to "9",
2827 "+", and "-". Alias names are not case sensitive, and are not required to start
2828 with a "+" or "-" sign, since they are merely textually expanded.
2830 Aliases can be used throughout the actions file, but they must be defined in a
2831 special section at the top of the file! And there can only be one such section
2832 per actions file. Each actions file may have its own alias section, and the
2833 aliases defined in it are only visible within that file.
2835 There are two main reasons to use aliases: One is to save typing for frequently
2836 used combinations of actions, the other one is a gain in flexibility: If you
2837 decide once how you want to handle shops by defining an alias called "shop",
2838 you can later change your policy on shops in one place, and your changes will
2839 take effect everywhere in the actions file where the "shop" alias is used.
2840 Calling aliases by their purpose also makes your actions files more readable.
2842 Currently, there is one big drawback to using aliases, though: Privoxy's
2843 built-in web-based action file editor honors aliases when reading the actions
2844 files, but it expands them before writing. So the effects of your aliases are
2845 of course preserved, but the aliases themselves are lost when you edit sections
2846 that use aliases with it. This is likely to change in future versions of
2849 Now let's define some aliases...
2851 # Useful custom aliases we can use later.
2853 # Note the (required!) section header line and that this section
2854 # must be at the top of the actions file!
2858 # These aliases just save typing later:
2859 # (Note that some already use other aliases!)
2861 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
2862 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
2863 block-as-image = +block +handle-as-image
2864 mercy-for-cookies = -crunch-all-cookies -session-cookies-only
2866 # These aliases define combinations of actions
2867 # that are useful for certain types of sites:
2869 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
2870 shop = -crunch-all-cookies -filter{popups} -kill-popups
2872 # Short names for other aliases, for really lazy people ;-)
2874 c0 = +crunch-all-cookies
2875 c1 = -crunch-all-cookies
2877 ...and put them to use. These sections would appear in the lower part of an
2878 actions file and define exceptions to the default actions (as specified further
2879 up for the "/" pattern):
2881 # These sites are either very complex or very keen on
2882 # user data and require minimal interference to work:
2885 .office.microsoft.com
2886 .windowsupdate.microsoft.com
2890 # Allow cookies (for setting and retrieving your customer data)
2894 .worldpay.com # for quietpc.com
2897 # These shops require pop-ups:
2899 {shop -kill-popups -filter{popups}}
2903 Aliases like "shop" and "fragile" are often used for "problem" sites that
2904 require some actions to be disabled in order to function properly.
2905 -------------------------------------------------------------------------------
2907 8.7. Actions Files Tutorial
2909 The above chapters have shown which actions files there are and how they are
2910 organized, how actions are specified and applied to URLs, how patterns work,
2911 and how to define and use aliases. Now, let's look at an example default.action
2912 and user.action file and see how all these pieces come together:
2913 -------------------------------------------------------------------------------
2915 8.7.1. default.action
2917 Every config file should start with a short comment stating its purpose:
2919 # Sample default.action file <developers@privoxy.org>
2921 Then, since this is the default.action file, the first section is a special
2922 section for internal use that you needn't change or worry about:
2924 ##########################################################################
2925 # Settings -- Don't change! For internal Privoxy use ONLY.
2926 ##########################################################################
2929 for-privoxy-version=3.0
2931 After that comes the (optional) alias section. We'll use the example section
2932 from the above chapter on aliases, that also explains why and how aliases are
2935 ##########################################################################
2937 ##########################################################################
2940 # These aliases just save typing later:
2941 # (Note that some already use other aliases!)
2943 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
2944 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
2945 block-as-image = +block +handle-as-image
2946 mercy-for-cookies = -crunch-all-cookies -session-cookies-only
2948 # These aliases define combinations of actions
2949 # that are useful for certain types of sites:
2951 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
2952 shop = mercy-for-cookies -filter{popups} -kill-popups
2954 Now come the regular sections, i.e. sets of actions, accompanied by URL
2955 patterns to which they apply. Remember all actions are disabled when matching
2956 starts, so we have to explicitly enable the ones we want.
2958 The first regular section is probably the most important. It has only one
2959 pattern, "/", but this pattern matches all URLs. Therefore, the set of actions
2960 used in this "default" section will be applied to all requests as a start. It
2961 can be partly or wholly overridden by later matches further down this file, or
2962 in user.action, but it will still be largely responsible for your overall
2963 browsing experience.
2965 Again, at the start of matching, all actions are disabled, so there is no real
2966 need to disable any actions here, but we will do that nonetheless, to have a
2967 complete listing for your reference. (Remember: a "+" preceding the action name
2968 enables the action, a "-" disables!). Also note how this long line has been
2969 made more readable by splitting it into multiple lines with line continuation.
2971 ##########################################################################
2972 # "Defaults" section:
2973 ##########################################################################
2977 -crunch-incoming-cookies \
2978 -crunch-outgoing-cookies \
2980 -downgrade-http-version \
2982 +filter{html-annoyances} \
2983 +filter{js-annoyances} \
2984 -filter{content-cookies} \
2987 -filter{refresh-tags} \
2990 +filter{banners-by-size} \
2991 -filter{banners-by-link} \
2992 -filter{img-reorder} \
2993 -filter{shockwave-flash} \
2994 -filter{crude-parental} \
2995 -filter{js-events} \
2997 +hide-forwarded-for-headers \
2998 +hide-from-header{block} \
2999 +hide-referrer{forge} \
3003 +prevent-compression \
3004 -send-vanilla-wafer \
3006 +session-cookies-only \
3007 +set-image-blocker{pattern} \
3009 / # forward slash will match *all* potential URL patterns.
3011 The default behavior is now set. Note that some actions, like not hiding the
3012 user agent, are part of a "general policy" that applies universally and won't
3013 get any exceptions defined later. Other choices, like not blocking (which is
3014 understandably the default!) need exceptions, i.e. we need to specify
3015 explicitly what we want to block in later sections. We will also want to make
3016 exceptions from our general pop-up-killing, and use our defined aliases for
3019 The first of our specialized sections is concerned with "fragile" sites, i.e.
3020 sites that require minimum interference, because they are either very complex
3021 or very keen on tracking you (and have mechanisms in place that make them
3022 unusable for people who avoid being tracked). We will simply use our
3023 pre-defined fragile alias instead of stating the list of actions explicitly:
3025 ##########################################################################
3026 # Exceptions for sites that'll break under the default action set:
3027 ##########################################################################
3029 # "Fragile" Use a minimum set of actions for these sites (see alias above):
3032 .office.microsoft.com # surprise, surprise!
3033 .windowsupdate.microsoft.com
3035 Shopping sites are not as fragile, but they typically require cookies to log
3036 in, and pop-up windows for shopping carts or item details. Again, we'll use a
3043 .worldpay.com # for quietpc.com
3047 Then, there are sites which rely on pop-up windows (yuck!) to work. Since we
3048 made pop-up-killing our default above, we need to make exceptions now. Mozilla
3049 users, who can turn on smart handling of unwanted pop-ups in their browsers,
3050 can safely choose -filter{popups} (and -kill-popups) above and hence don't need
3051 this section. Anyway, disabling an already disabled action doesn't hurt, so
3052 we'll define our exceptions regardless of what was chosen in the defaults
3055 # These sites require pop-ups too :(
3057 { -kill-popups -filter{popups} }
3060 .deutsche-bank-24.de
3062 The fast-redirects action, which we enabled per default above, breaks some
3063 sites. So disable it for popular sites where we know it misbehaves:
3069 .altavista.com/.*(like|url|link):http
3070 .altavista.com/trans.*urltext=http
3073 It is important that Privoxy knows which URLs belong to images, so that if they
3074 are to be blocked, a substitute image can be sent, rather than an HTML page.
3075 Contacting the remote site to find out is not an option, since it would destroy
3076 the loading time advantage of banner blocking, and it would feed the
3077 advertisers (in terms of money and information). We can mark any URL as an
3078 image with the handle-as-image action, and marking all URLs that end in a known
3079 image file extension is a good start:
3081 ##########################################################################
3083 ##########################################################################
3085 # Define which file types will be treated as images, in case they get
3086 # blocked further down this file:
3088 { +handle-as-image }
3089 /.*\.(gif|jpe?g|png|bmp|ico)$
3091 And then there are known banner sources. They often use scripts to generate the
3092 banners, so it won't be visible from the URL that the request is for an image.
3093 Hence we block them and mark them as images in one go, with the help of our
3094 block-as-image alias defined above. (We could of course just as well use +block
3095 +handle-as-image here.) Remember that the type of the replacement image is
3096 chosen by the set-image-blocker action. Since all URLs have matched the default
3097 section with its +set-image-blocker{pattern} action before, it still applies
3098 and needn't be repeated:
3100 # Known ad generators:
3105 .ad.*.doubleclick.net
3106 .a.yimg.com/(?:(?!/i/).)*$
3107 .a[0-9].yimg.com/(?:(?!/i/).)*$
3112 One of the most important jobs of Privoxy is to block banners. A huge bunch of
3113 them are already "blocked" by the filter{banners-by-size} action, which we
3114 enabled above, and which deletes the references to banner images from the pages
3115 while they are loaded, so the browser doesn't request them anymore, and hence
3116 they don't need to be blocked here. But this naturally doesn't catch all
3117 banners, and some people choose not to use filters, so we need a comprehensive
3118 list of patterns for banner URLs here, and apply the block action to them.
3120 First comes a bunch of generic patterns, which do most of the work, by matching
3121 typical domain and path name components of banners. Then comes a list of
3122 individual patterns for specific sites, which is omitted here to keep the
3125 ##########################################################################
3126 # Block these fine banners:
3127 ##########################################################################
3136 /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
3137 /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
3139 # Site-specific patterns (abbreviated):
3143 You wouldn't believe how many advertisers actually call their banner servers
3144 ads.company.com, or call the directory in which the banners are stored simply
3145 "banners". So the above generic patterns are surprisingly effective.
3147 But being very generic, they necessarily also catch URLs that we don't want to
3148 block. The pattern .*ads. e.g. catches "nasty-ads.nasty-corp.com" as intended,
3149 but also "downloads.sourcefroge.net" or "adsl.some-provider.net." So here come
3150 some well-known exceptions to the +block section above.
3152 Note that these are exceptions to exceptions from the default! Consider the URL
3153 "downloads.sourcefroge.net": Initially, all actions are deactivated, so it
3154 wouldn't get blocked. Then comes the defaults section, which matches the URL,
3155 but just deactivates the block action once again. Then it matches .*ads., an
3156 exception to the general non-blocking policy, and suddenly +block applies. And
3157 now, it'll match .*loads., where -block applies, so (unless it matches again
3158 further down) it ends up with no block action applying.
3160 ##########################################################################
3161 # Save some innocent victims of the above generic block patterns:
3162 ##########################################################################
3167 adv[io]*. # (for advogato.org and advice.*)
3168 adsl. # (has nothing to do with ads)
3169 ad[ud]*. # (adult.* and add.*)
3170 .edu # (universities don't host banners (yet!))
3171 .*loads. # (downloads, uploads etc)
3179 www.globalintersec.com/adv # (adv = advanced)
3180 www.ugu.com/sui/ugu/adv
3182 Filtering source code can have nasty side effects, so make an exception for our
3183 friends at sourceforge.net, and all paths with "cvs" in them. Note that -filter
3184 disables all filters in one fell swoop!
3186 # Don't filter code!
3192 The actual default.action is of course more comprehensive, but we hope this
3193 example made clear how it works.
3194 -------------------------------------------------------------------------------
3198 So far we are painting with a broad brush by setting general policies, which
3199 would be a reasonable starting point for many people. Now, you might want to be
3200 more specific and have customized rules that are more suitable to your personal
3201 habits and preferences. These would be for narrowly defined situations like
3202 your ISP or your bank, and should be placed in user.action, which is parsed
3203 after all other actions files and hence has the last word, over-riding any
3204 previously defined actions. user.action is also a safe place for your personal
3205 settings, since default.action is actively maintained by the Privoxy developers
3206 and you'll probably want to install updated versions from time to time.
3208 So let's look at a few examples of things that one might typically do in
3211 # My user.action file. <fred@foobar.com>
3213 As aliases are local to the actions file that they are defined in, you can't
3214 use the ones from default.action, unless you repeat them here:
3216 # (Re-)define aliases for this file:
3219 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
3220 mercy-for-cookies = -crunch-all-cookies -session-cookies-only
3221 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
3222 shop = mercy-for-cookies -filter{popups} -kill-popups
3223 allow-ads = -block -filter{banners-by-size} # (see below)
3225 Say you have accounts on some sites that you visit regularly, and you don't
3226 want to have to log in manually each time. So you'd like to allow persistent
3227 cookies for these sites. The mercy-for-cookies alias defined above does exactly
3228 that, i.e. it disables crunching of cookies in any direction, and processing of
3229 cookies to make them temporary.
3231 { mercy-for-cookies }
3238 Your bank needs popups and is allergic to some filter, but you don't know
3239 which, so you disable them all:
3241 { -filter -kill-popups }
3242 .your-home-banking-site.com
3244 While browsing the web with Privoxy you noticed some ads that sneaked through,
3245 but you were too lazy to report them through our fine and easy feedback system,
3246 so you have added them here:
3249 www.a-popular-site.com/some/unobvious/path
3250 another.popular.site.net/more/junk/here/
3252 Note that, assuming the banners in the above example have regular image
3253 extensions (most do), +handle-as-image need not be specified, since all URLs
3254 ending in these extensions will already have been tagged as images in the
3255 relevant section of default.action by now.
3257 Then you noticed that the default configuration breaks Forbes Magazine, but you
3258 were too lazy to find out which action is the culprit, and you were again too
3259 lazy to give feedback, so you just used the fragile alias on the site, and --
3265 You like the "fun" text replacements in default.filter, but it is disabled in
3266 the distributed actions file. (My colleagues on the team just don't have a
3267 sense of humour, that's why! ;-). So you'd like to turn it on in your private,
3268 update-safe config, once and for all:
3273 Note that the above is not really a good idea: There are exceptions to the
3274 filters in default.action for things that really shouldn't be filtered, like
3275 code on CVS->Web interfaces. Since user.action has the last word, these
3276 exceptions won't be valid for the "fun" filtering specified here.
3278 Finally, you might think about how your favourite free websites are funded, and
3279 find that they rely on displaying banner advertisements to survive. So you
3280 might want to specifically allow banners for those sites that you feel provide
3288 Note that allow-ads has been aliased to -block -filter{banners-by-size} above.
3289 -------------------------------------------------------------------------------
3293 All text substitutions that can be invoked through the filter action must first
3294 be defined in the filter file, which is typically called default.filter and
3295 which can be selected through the filterfile config option.
3297 Typical reasons for doing such substitutions are to eliminate common annoyances
3298 in HTML and JavaScript, such as pop-up windows, exit consoles, crippled windows
3299 without navigation tools, the infamous <BLINK> tag etc, to suppress images with
3300 certain width and height attributes (standard banner sizes or web-bugs), or
3301 just to have fun. The possibilities are endless.
3303 Filtering works on any text-based document type, including plain text, HTML,
3304 JavaScript, CSS etc. (all text/* MIME types). Substitutions are made at the
3305 source level, so if you want to "roll your own" filters, you should be familiar
3308 Just like the actions files, the filter file is organized in sections, which
3309 are called filters here. Each filter consists of a heading line, that starts
3310 with the keyword FILTER:, followed by the filter's name, and a short (one line)
3311 description of what it does. Below that line come the jobs, i.e. lines that
3312 define the actual text substitutions. By convention, the name of a filter
3313 should describe what the filter eliminates. The comment is used in the
3314 web-based user interface.
3316 Once a filter called name has been defined in the filter file, it can be
3317 invoked by using an action of the form +filter{name} in any actions file.
3319 A filter header line for a filter called "foo" could look like this:
3321 FILTER: foo Replace all "foo" with "bar"
3323 Below that line, and up to the next header line, come the jobs that define what
3324 text replacements the filter executes. They are specified in a syntax that
3325 imitates Perl's s/// operator. If you are familiar with Perl, you will find
3326 this to be quite intuitive, and may want to look at the PCRS man page for the
3327 subtle differences to Perl behaviour. Most notably, the non-standard option
3328 letter U is supported, which turns the default to ungreedy matching.
3330 If you are new to regular expressions, you might want to take a look at the
3331 Appendix on regular expressions, and see the Perl manual for the s///
3332 operator's syntax and Perl-style regular expressions in general. The below
3333 examples might also help to get you started.
3334 -------------------------------------------------------------------------------
3336 9.1. Filter File Tutorial
3338 Now, let's complete our "foo" filter. We have already defined the heading, but
3339 the jobs are still missing. Since all it does is to replace "foo" with "bar",
3340 there is only one (trivial) job needed:
3344 But wait! Didn't the comment say that all occurrences of "foo" should be
3345 replaced? Our current job will only take care of the first "foo" on each page.
3346 For global substitution, we'll need to add the g option:
3350 Our complete filter now looks like this:
3352 FILTER: foo Replace all "foo" with "bar"
3355 Let's look at some real filters for more interesting examples. Here you see a
3356 filter that protects against some common annoyances that arise from JavaScript
3357 abuse. Let's look at its jobs one after the other:
3359 FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse
3361 # Get rid of JavaScript referrer tracking. Test page: http://www.randomoddness.com/untitled.htm
3363 s|(<script.*)document\.referrer(.*</script>)|$1"Not Your Business!"$2|Usg
3365 Following the header line and a comment, you see the job. Note that it uses |
3366 as the delimiter instead of /, because the pattern contains a forward slash,
3367 which would otherwise have to be escaped by a backslash (\).
3369 Now, let's examine the pattern: it starts with the text <script.* enclosed in
3370 parentheses. Since the dot matches any character, and * means: "Match an
3371 arbitrary number of the element left of myself", this matches "<script",
3372 followed by any text, i.e. it matches the whole page, from the start of the
3375 That's more than we want, but the pattern continues: document\.referrer matches
3376 only the exact string "document.referrer". The dot needed to be escaped, i.e.
3377 preceded by a backslash, to take away its special meaning as a joker, and make
3378 it just a regular dot. So far, the meaning is: Match from the start of the
3379 first <script> tag in a the page, up to, and including, the text
3380 "document.referrer", if both are present in the page (and appear in that
3383 But there's still more pattern to go. The next element, again enclosed in
3384 parentheses, is .*</script>. You already know what .* means, so the whole
3385 pattern translates to: Match from the start of the first <script> tag in a page
3386 to the end of the last <script> tag, provided that the text "document.referrer"
3387 appears somewhere in between.
3389 This is still not the whole story, since we have ignored the options and the
3390 parentheses: The portions of the page matched by sub-patterns that are enclosed
3391 in parentheses, will be remembered and be available through the variables $1,
3392 $2, ... in the substitute. The U option switches to ungreedy matching, which
3393 means that the first .* in the pattern will only "eat up" all text in between "
3394 <script" and the first occurrence of "document.referrer", and that the second .
3395 * will only span the text up to the first "</script>" tag. Furthermore, the s
3396 option says that the match may span multiple lines in the page, and the g
3397 option again means that the substitution is global.
3399 So, to summarize, the pattern means: Match all scripts that contain the text
3400 "document.referrer". Remember the parts of the script from (and including) the
3401 start tag up to (and excluding) the string "document.referrer" as $1, and the
3402 part following that string, up to and including the closing tag, as $2.
3404 Now the pattern is deciphered, but wasn't this about substituting things? So
3405 lets look at the substitute: $1"Not Your Business!"$2 is easy to read: The text
3406 remembered as $1, followed by "Not Your Business!" (including the quotation
3407 marks!), followed by the text remembered as $2. This produces an exact copy of
3408 the original string, with the middle part (the "document.referrer") replaced by
3409 "Not Your Business!".
3411 The whole job now reads: Replace "document.referrer" by "Not Your Business!"
3412 wherever it appears inside a <script> tag. Note that this job won't break
3413 JavaScript syntax, since both the original and the replacement are
3414 syntactically valid string objects. The script just won't have access to the
3415 referrer information anymore.
3417 We'll show you two other jobs from the JavaScript taming department, but this
3418 time only point out the constructs of special interest:
3420 # The status bar is for displaying link targets, not pointless blahblah
3422 s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig
3424 \s stands for whitespace characters (space, tab, newline, carriage return, form
3425 feed), so that \s* means: "zero or more whitespace". The ? in .*? makes this
3426 matching of arbitrary text ungreedy. (Note that the U option is not set). The
3427 ['"] construct means: "a single or a double quote". Finally, \1 is a
3428 backreference to the first parenthesis just like $1 above, with the difference
3429 that in the pattern, a backslash indicates a backreference, whereas in the
3430 substitute, it's the dollar.
3432 So what does this job do? It replaces assignments of single- or double-quoted
3433 strings to the "window.status" object with a dummy assignment (using a variable
3434 name that is hopefully odd enough not to conflict with real variables in
3435 scripts). Thus, it catches many cases where e.g. pointless descriptions are
3436 displayed in the status bar instead of the link target when you move your mouse
3439 # Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html
3441 s/(<body [^>]*)onunload(.*>)/$1never$2/iU
3443 Including the OnUnload event binding in the HTML DOM was a CRIME. When I close
3444 a browser window, I want it to close and die. Basta. This job replaces the
3445 "onunload" attribute in "<body>" tags with the dummy word never. Note that the
3446 i option makes the pattern matching case-insensitive. Also note that ungreedy
3447 matching alone doesn't always guarantee a minimal match: In the first
3448 parenthesis, we had to use [^>]* instead of .* to prevent the match from
3449 exceeding the <body> tag if it doesn't contain "OnUnload", but the page's
3452 The last example is from the fun department:
3454 FILTER: fun Fun text replacements
3456 # Spice the daily news:
3458 s/microsoft(?!\.com)/MicroSuck/ig
3460 Note the (?!\.com) part (a so-called negative lookahead) in the job's pattern,
3461 which means: Don't match, if the string ".com" appears directly following
3462 "microsoft" in the page. This prevents links to microsoft.com from being
3463 trashed, while still replacing the word everywhere else.
3465 # Buzzword Bingo (example for extended regex syntax)
3467 s* industry[ -]leading \
3469 | customer[ -]focused \
3470 | market[ -]driven \
3471 | award[ -]winning # Comments are OK, too! \
3472 | high[ -]performance \
3473 | solutions[ -]based \
3477 *<font color="red"><b>BINGO!</b></font> \
3480 The x option in this job turns on extended syntax, and allows for e.g. the
3481 liberal use of (non-interpreted!) whitespace for nicer formatting.
3484 -------------------------------------------------------------------------------
3488 All Privoxy built-in pages, i.e. error pages such as the "404 - No Such Domain"
3489 error page, the "BLOCKED" page and all pages of its web-based user interface,
3490 are generated from templates. (Privoxy must be running for the above links to
3493 These templates are stored in a subdirectory of the configuration directory
3494 called templates. On Unixish platforms, this is typically /etc/privoxy/
3497 The templates are basically normal HTML files, but with place-holders (called
3498 symbols or exports), which Privoxy fills at run time. You can edit the
3499 templates with a normal text editor, should you want to customize them. (Not
3500 recommended for the casual user). Note that just like in configuration files,
3501 lines starting with # are ignored when the templates are filled in.
3503 The place-holders are of the form @name@, and you will find a list of available
3504 symbols, which vary from template to template, in the comments at the start of
3505 each file. Note that these comments are not always accurate, and that it's
3506 probably best to look at the existing HTML code to find out which symbols are
3507 supported and what they are filled in with.
3509 A special application of this substitution mechanism is to make whole blocks of
3510 HTML code disappear when a specific symbol is set. We use this for many
3511 purposes, one of them being to include the beta warning in all our user
3512 interface (CGI) pages when Privoxy in in an alpha or beta development stage:
3514 <!-- @if-unstable-start -->
3516 ... beta warning HTML code goes here ...
3518 <!-- if-unstable-end@ -->
3520 If the "unstable" symbol is set, everything in between and including
3521 @if-unstable-start and if-unstable-end@ will disappear, leaving nothing but an
3526 There's also an if-then-else construct and an #include mechanism, but you'll
3527 sure find out if you are inclined to edit the templates ;-)
3529 All templates refer to a style located at http://config.privoxy.org/
3530 send-stylesheet. This is, of course, locally served by Privoxy and the source
3531 for it can be found and edited in the cgi-style.css template.
3532 -------------------------------------------------------------------------------
3534 11. Contacting the Developers, Bug Reporting and Feature Requests
3536 We value your feedback. In fact, we rely on it to improve Privoxy and its
3537 configuration. However, please note the following hints, so we can provide you
3538 with the best support:
3539 -------------------------------------------------------------------------------
3543 For casual users, our support forum at SourceForge is probably best suited:
3544 http://sourceforge.net/tracker/?group_id=11118&atid=211118
3546 All users are of course welcome to discuss their issues on the users mailing
3547 list, where the developers also hang around.
3548 -------------------------------------------------------------------------------
3552 Please report all bugs only through our bug tracker: http://sourceforge.net/
3553 tracker/?group_id=11118&atid=111118.
3555 Before doing so, please make sure that the bug has not already been submitted
3556 and observe the additional hints at the top of the submit form.
3558 Please try to verify that it is a Privoxy bug, and not a browser or site bug
3559 first. If unsure, try toggling off Privoxy, and see if the problem persists.
3560 The appendix of the user manual also has helpful information on action
3561 debugging. If you are using your own custom configuration, please try the stock
3562 configs to see if the problem is configuration related.
3564 If not using the latest version, chances are that the bug has been found and
3565 fixed in the meantime. We would appreciate if you could take the time to
3566 upgrade to the latest version (or even the latest CVS snapshot) and verify your
3567 bug, but this is not required for reporting.
3568 -------------------------------------------------------------------------------
3570 11.3. Request New Features
3572 You are welcome to submit ideas on new features or other proposals for
3573 improvement through our feature request tracker at http://sourceforge.net/
3574 tracker/?atid=361118&group_id=11118.
3575 -------------------------------------------------------------------------------
3577 11.4. Report Ads or Other Actions-Related Problems
3579 Please send feedback on ads that slipped through, innocent images that were
3580 blocked, and any other problems relating to the default.action file through our
3581 actions feedback mechanism located at http://www.privoxy.org/actions/. On this
3582 page, you will also find a bookmark which will take you back there from any
3583 troubled site and even pre-fill the form!
3585 New, improved default.action files will occasionally be made available based on
3586 your feedback. These will be announced on the ijbswa-announce list and
3587 available from our the files section of our project page.
3588 -------------------------------------------------------------------------------
3592 For any other issues, feel free to use the mailing lists. Technically
3593 interested users and people who wish to contribute to the project are also
3594 welcome on the developers list! You can find an overview of all Privoxy-related
3595 mailing lists, including list archives, at: http://sourceforge.net/mail/?
3597 -------------------------------------------------------------------------------
3599 12. Privoxy Copyright, License and History
3601 Copyright © 2001, 2002 by Privoxy Developers <developers@privoxy.org>
3603 Some source code is based on code Copyright © 1997 by Anonymous Coders and
3604 Junkbusters, Inc. and licensed under the GNU General Public License.
3605 -------------------------------------------------------------------------------
3609 Privoxy is free software; you can redistribute it and/or modify it under the
3610 terms of the GNU General Public License, version 2, as published by the Free
3611 Software Foundation.
3613 This program is distributed in the hope that it will be useful, but WITHOUT ANY
3614 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
3615 PARTICULAR PURPOSE. See the GNU General Public License for more details, which
3616 is available from the Free Software Foundation, Inc, 59 Temple Place - Suite
3617 330, Boston, MA 02111-1307, USA.
3619 You should have received a copy of the GNU General Public License along with
3620 this program; if not, write to the
3623 Foundation, Inc. 59 Temple Place - Suite 330
3624 Boston, MA 02111-1307
3626 -------------------------------------------------------------------------------
3630 In the beginning, there was the Internet Junkbuster, by Anonymous Coders and
3631 Junkbusters Corporation. It saved many users a lot of pain in the early days of
3632 web advertising and user tracking.
3634 But the web, its protocols and standards, and with it, the techniques for
3635 forcing users to consume ads, give up autonomy over their browsing, and for
3636 spying on them, kept evolving. Unfortunately, the Internet Junkbuster did not.
3637 Version 2.0.2, published in 1998, was (and is) the last official release
3638 available from Junkbusters Corporation. Fortunately, it had been released under
3639 the GNU GPL, which allowed further development by others.
3641 So Stefan Waldherr started maintaining an improved version of the software, to
3642 which eventually a number of people contributed patches. It could already
3643 replace banners with a transparent image, and had a first version of pop-up
3644 killing, but it was still very closely based on the original, with all its
3645 limitations, such as the lack of HTTP/1.1 support, flexible per-site
3646 configuration, or content modification. The last release from this effort was
3647 version 2.0.2-10, published in 2000.
3649 Then, some developers picked up the thread, and started turning the software
3650 inside out, upside down, and then reassembled it, adding many new features
3653 The result of this is Privoxy, whose first stable release, 3.0, is due late
3654 summer or early fall 2002.
3655 -------------------------------------------------------------------------------
3659 Current Project Developers:
3668 Current Project Contributors:
3670 Rodrigo Barbosa (RPM specfiles)
3679 David Schmidt (OS/2, Mac OSX ports)
3683 Based in part on code originally developed by:
3688 Thanks to the many people who have tested Privoxy, reported bugs, or made
3689 suggestions. These include (in alphabetical order):
3706 -------------------------------------------------------------------------------
3710 Other references and sites of interest to Privoxy users:
3712 http://www.privoxy.org/, the Privoxy Home page.
3714 http://www.privoxy.org/faq/, the Privoxy FAQ.
3716 http://sourceforge.net/projects/ijbswa/, the Project Page for Privoxy on
3719 http://config.privoxy.org/, the web-based user interface. Privoxy must be
3720 running for this to work. Shortcut: http://p.p/
3722 http://www.privoxy.org/actions/, to submit "misses" to the developers.
3724 http://www.junkbusters.com/ht/en/cookies.html, an explanation how cookies are
3725 used to track web users.
3727 http://www.junkbusters.com/ijb.html, the original Internet Junkbuster.
3729 http://www.waldherr.org/junkbuster/, Stefan Waldherr's version of Junkbuster,
3730 from which Privoxy was derived.
3732 http://privacy.net/analyze/, a useful site to check what information about you
3733 is leaked while you browse the web.
3735 http://www.squid-cache.org/, a very popular caching proxy, which is often used
3736 together with Privoxy.
3738 http://www.privoxy.org/developer-manual/, the Privoxy developer manual.
3740 -------------------------------------------------------------------------------
3743 14.1. Regular Expressions
3745 Privoxy uses Perl-style "regular expressions" in its actions files and filter
3746 file, through the PCRE and PCRS libraries.
3748 If you are reading this, you probably don't understand what "regular
3749 expressions" are, or what they can do. So this will be a very brief
3750 introduction only. A full explanation would require a book ;-)
3752 Regular expressions provide a language to describe patterns that can be run
3753 against strings of characters (letter, numbers, etc), to see if they match the
3754 string or not. The patterns are themselves (sometimes complex) strings of
3755 literal characters, combined with wild-cards, and other special characters,
3756 called meta-characters. The "meta-characters" have special meanings and are
3757 used to build complex patterns to be matched against. Perl Compatible Regular
3758 Expressions are an especially convenient "dialect" of the regular expression
3761 To make a simple analogy, we do something similar when we use wild-card
3762 characters when listing files with the dir command in DOS. *.* matches all
3763 filenames. The "special" character here is the asterisk which matches any and
3764 all characters. We can be more specific and use ? to match just individual
3765 characters. So "dir file?.text" would match "file1.txt", "file2.txt", etc. We
3766 are pattern matching, using a similar technique to "regular expressions"!
3768 Regular expressions do essentially the same thing, but are much, much more
3769 powerful. There are many more "special characters" and ways of building complex
3770 patterns however. Let's look at a few of the common ones, and then some
3773 . - Matches any single character, e.g. "a", "A", "4", ":", or "@".
3775 ? - The preceding character or expression is matched ZERO or ONE times. Either/
3778 + - The preceding character or expression is matched ONE or MORE times.
3780 * - The preceding character or expression is matched ZERO or MORE times.
3782 \ - The "escape" character denotes that the following character should be taken
3783 literally. This is used where one of the special characters (e.g. ".") needs to
3784 be taken literally and not as a special meta-character. Example: "example\.com"
3785 , makes sure the period is recognized only as a period (and not expanded to its
3786 meta-character meaning of any single character).
3788 [] - Characters enclosed in brackets will be matched if any of the enclosed
3789 characters are encountered. For instance, "[0-9]" matches any numeric digit
3790 (zero through nine). As an example, we can combine this with "+" to match any
3791 digit one of more times: "[0-9]+".
3793 () - parentheses are used to group a sub-expression, or multiple
3796 | - The "bar" character works like an "or" conditional statement. A match is
3797 successful if the sub-expression on either side of "|" matches. As an example:
3798 "/(this|that) example/" uses grouping and the bar character and would match
3799 either "this example" or "that example", and nothing else.
3801 These are just some of the ones you are likely to use when matching URLs with
3802 Privoxy, and is a long way from a definitive list. This is enough to get us
3803 started with a few simple examples which may be more illuminating:
3805 /.*/banners/.* - A simple example that uses the common combination of "." and "
3806 *" to denote any character, zero or more times. In other words, any string at
3807 all. So we start with a literal forward slash, then our regular expression
3808 pattern (".*") another literal forward slash, the string "banners", another
3809 forward slash, and lastly another ".*". We are building a directory path here.
3810 This will match any file with the path that has a directory named "banners" in
3811 it. The ".*" matches any characters, and this could conceivably be more forward
3812 slashes, so it might expand into a much longer looking path. For example, this
3813 could match: "/eye/hate/spammers/banners/annoy_me_please.gif", or just "/
3814 banners/annoying.html", or almost an infinite number of other possible
3815 combinations, just so it has "banners" in the path somewhere.
3817 A now something a little more complex:
3819 /.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward
3820 slashes again ("/"), so we are building another expression that is a file path
3821 statement. We have another ".*", so we are matching against any conceivable
3822 sub-path, just so it matches our expression. The only true literal that must
3823 match our pattern is adv, together with the forward slashes. What comes after
3824 the "adv" string is the interesting part.
3826 Remember the "?" means the preceding expression (either a literal character or
3827 anything grouped with "(...)" in this case) can exist or not, since this means
3828 either zero or one match. So "((er)?ts?|ertis(ing|ements?))" is optional, as
3829 are the individual sub-expressions: "(er)", "(ing|ements?)", and the "s". The "
3830 |" means "or". We have two of those. For instance, "(ing|ements?)", can expand
3831 to match either "ing" OR "ements?". What is being done here, is an attempt at
3832 matching as many variations of "advertisement", and similar, as possible. So
3833 this would expand to match just "adv", or "advert", or "adverts", or
3834 "advertising", or "advertisement", or "advertisements". You get the idea. But
3835 it would not match "advertizements" (with a "z"). We could fix that by changing
3836 our regular expression to: "/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/", which
3837 would then match either spelling.
3839 /.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward
3840 slashes. Anything in the square brackets "[]" can be matched. This is using
3841 "0-9" as a shorthand expression to mean any digit one through nine. It is the
3842 same as saying "0123456789". So any digit matches. The "+" means one or more of
3843 the preceding expression must be included. The preceding expression here is
3844 what is in the square brackets -- in this case, any digit one through nine.
3845 Then, at the end, we have a grouping: "(gif|jpe?g)". This includes a "|", so
3846 this needs to match the expression on either side of that bar character also. A
3847 simple "gif" on one side, and the other side will in turn match either "jpeg"
3848 or "jpg", since the "?" means the letter "e" is optional and can be matched
3849 once or not at all. So we are building an expression here to match image GIF or
3850 JPEG type image file. It must include the literal string "advert", then one or
3851 more digits, and a "." (which is now a literal, and not a special character,
3852 since it is escaped with "\"), and lastly either "gif", or "jpeg", or "jpg".
3853 Some possible matches would include: "//advert1.jpg", "/nasty/ads/
3854 advert1234.gif", "/banners/from/hell/advert99.jpg". It would not match
3855 "advert1.gif" (no leading slash), or "/adverts232.jpg" (the expression does not
3856 include an "s"), or "/advert1.jsp" ("jsp" is not in the expression anywhere).
3858 We are barely scratching the surface of regular expressions here so that you
3859 can understand the default Privoxy configuration files, and maybe use this
3860 knowledge to customize your own installation. There is much, much more that can
3861 be done with regular expressions. Now that you know enough to get started, you
3862 can learn more on your own :/
3864 More reading on Perl Compatible Regular expressions: http://www.perldoc.com/
3865 perl5.6/pod/perlre.html
3867 For information on regular expression based substitutions and their
3868 applications in filters, please see the filter file tutorial in this manual.
3869 -------------------------------------------------------------------------------
3871 14.2. Privoxy's Internal Pages
3873 Since Privoxy proxies each requested web page, it is easy for Privoxy to trap
3874 certain special URLs. In this way, we can talk directly to Privoxy, and see how
3875 it is configured, see how our rules are being applied, change these rules and
3876 other configuration options, and even turn Privoxy's filtering off, all with a
3879 The URLs listed below are the special ones that allow direct access to Privoxy.
3880 Of course, Privoxy must be running to access these. If not, you will get a
3881 friendly error message. Internet access is not necessary either.
3883 * Privoxy main page:
3886 http://config.privoxy.org/
3889 There is a shortcut: http://p.p/ (But it doesn't provide a fall-back to a
3890 real page, in case the request is not sent through Privoxy)
3892 * Show information about the current configuration, including viewing and
3893 editing of actions files:
3896 http://config.privoxy.org/show-status
3899 * Show the source code version numbers:
3902 http://config.privoxy.org/show-version
3905 * Show the browser's request headers:
3908 http://config.privoxy.org/show-request
3911 * Show which actions apply to a URL and why:
3914 http://config.privoxy.org/show-url-info
3917 * Toggle Privoxy on or off. In this case, "Privoxy" continues to run, but
3918 only as a pass-through proxy, with no actions taking place:
3921 http://config.privoxy.org/toggle
3924 Short cuts. Turn off, then on:
3927 http://config.privoxy.org/toggle?set=disable
3931 http://config.privoxy.org/toggle?set=enable
3935 These may be bookmarked for quick reference. See next.
3936 -------------------------------------------------------------------------------
3938 14.2.1. Bookmarklets
3940 Below are some "bookmarklets" to allow you to easily access a "mini" version of
3941 some of Privoxy's special pages. They are designed for MS Internet Explorer,
3942 but should work equally well in Netscape, Mozilla, and other browsers which
3943 support JavaScript. They are designed to run directly from your bookmarks - not
3944 by clicking the links below (although that should work for testing).
3946 To save them, right-click the link and choose "Add to Favorites" (IE) or "Add
3947 Bookmark" (Netscape). You will get a warning that the bookmark "may not be
3948 safe" - just click OK. Then you can run the Bookmarklet directly from your
3949 favorites/bookmarks. For even faster access, you can put them on the "Links"
3950 bar (IE) or the "Personal Toolbar" (Netscape), and run them with a single
3957 * Privoxy - Toggle Privoxy (Toggles between enabled and disabled)
3959 * Privoxy- View Status
3961 * Privoxy - Submit Actions File Feedback
3966 Credit: The site which gave us the general idea for these bookmarklets is
3967 www.bookmarklets.com. They have more information about bookmarklets.
3968 -------------------------------------------------------------------------------
3970 14.3. Chain of Events
3972 Let's take a quick look at the basic sequence of events when a web page is
3973 requested by your browser and Privoxy is on duty:
3975 * First, your web browser requests a web page. The browser knows to send the
3976 request to Privoxy, which will in turn, relay the request to the remote web
3977 server after passing the following tests:
3979 * Privoxy traps any request for its own internal CGI pages (e.g http://p.p/)
3980 and sends the CGI page back to the browser.
3982 * Next, Privoxy checks to see if the URL matches any "+block" patterns. If
3983 so, the URL is then blocked, and the remote web server will not be
3984 contacted. "+handle-as-image" is then checked and if it does not match, an
3985 HTML "BLOCKED" page is sent back. Otherwise, if it does match, an image is
3986 returned. The type of image depends on the setting of "+set-image-blocker"
3987 (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
3989 * Untrusted URLs are blocked. If URLs are being added to the trust file, then
3992 * If the URL pattern matches the "+fast-redirects" action, it is then
3993 processed. Unwanted parts of the requested URL are stripped.
3995 * Now the rest of the client browser's request headers are processed. If any
3996 of these match any of the relevant actions (e.g. "+hide-user-agent", etc.),
3997 headers are suppressed or forged as determined by these actions and their
4000 * Now the web server starts sending its response back (i.e. typically a web
4001 page and related data).
4003 * First, the server headers are read and processed to determine, among other
4004 things, the MIME type (document type) and encoding. The headers are then
4005 filtered as deterimined by the "+crunch-incoming-cookies",
4006 "+session-cookies-only", and "+downgrade-http-version" actions.
4008 * If the "+kill-popups" action applies, and it is an HTML or JavaScript
4009 document, the popup-code in the response is filtered on-the-fly as it is
4012 * If a "+filter" or "+deanimate-gifs" action applies (and the document type
4013 fits the action), the rest of the page is read into memory (up to a
4014 configurable limit). Then the filter rules (from default.filter) are
4015 processed against the buffered content. Filters are applied in the order
4016 they are specified in the default.filter file. Animated GIFs, if present,
4017 are reduced to either the first or last frame, depending on the action
4018 setting.The entire page, which is now filtered, is then sent by Privoxy
4019 back to your browser.
4021 If neither "+filter" or "+deanimate-gifs" matches, then Privoxy passes the
4022 raw data through to the client browser as it becomes available.
4024 * As the browser receives the now (probably filtered) page content, it reads
4025 and then requests any URLs that may be embedded within the page source,
4026 e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
4027 frames), sounds, etc. For each of these objects, the browser issues a new
4028 request. And each such request is in turn processed as above. Note that a
4029 complex web page may have many such embedded URLs.
4032 -------------------------------------------------------------------------------
4033 14.4. Anatomy of an Action
4035 The way Privoxy applies actions and filters to any given URL can be complex,
4036 and not always so easy to understand what is happening. And sometimes we need
4037 to be able to see just what Privoxy is doing. Especially, if something Privoxy
4038 is doing is causing us a problem inadvertently. It can be a little daunting to
4039 look at the actions and filters files themselves, since they tend to be filled
4040 with regular expressions whose consequences are not always so obvious.
4042 One quick test to see if Privoxy is causing a problem or not, is to disable it
4043 temporarily. This should be the first troubleshooting step. See the
4044 Bookmarklets section on a quick and easy way to do this (be sure to flush
4045 caches afterward!). Looking at the logs is a good idea too.
4047 Privoxy also provides the http://config.privoxy.org/show-url-info page that can
4048 show us very specifically how actions are being applied to any given URL. This
4049 is a big help for troubleshooting.
4051 First, enter one URL (or partial URL) at the prompt, and then Privoxy will tell
4052 us how the current configuration will handle it. This will not help with
4053 filtering effects (i.e. the "+filter" action) from the default.filter file
4054 since this is handled very differently and not so easy to trap! It also will
4055 not tell you about any other URLs that may be embedded within the URL you are
4056 testing. For instance, images such as ads are expressed as URLs within the raw
4057 page source of HTML pages. So you will only get info for the actual URL that is
4058 pasted into the prompt area -- not any sub-URLs. If you want to know about
4059 embedded URLs like ads, you will have to dig those out of the HTML source. Use
4060 your browser's "View Page Source" option for this. Or right click on the ad,
4063 Let's try an example, google.com, and look at it one section at a time:
4065 Matches for http://google.com:
4067 In file: default.action [ View ] [ Edit ]
4071 -crunch-outgoing-cookies
4072 -crunch-incoming-cookies
4073 +deanimate-gifs{last}
4074 -downgrade-http-version
4078 -filter{shockwave-flash}
4079 -filter{crude-parental}
4080 +filter{html-annoyances}
4081 +filter{js-annoyances}
4082 +filter{content-cookies}
4084 +filter{refresh-tags}
4086 +filter{banners-by-size}
4087 +hide-forwarded-for-headers
4088 +hide-from-header{block}
4089 +hide-referer{forge}
4094 +prevent-compression
4097 +session-cookies-only
4098 +set-image-blocker{pattern} }
4101 { -session-cookies-only }
4107 In file: user.action [ View ] [ Edit ]
4108 (no matches in this file)
4110 This tells us how we have defined our "actions", and which ones match for our
4111 example, "google.com". The first listing is any matches for the standard.action
4112 file. No hits at all here on "standard". Then next is "default", or our
4113 default.action file. The large, multi-line listing, is how the actions are set
4114 to match for all URLs, i.e. our default settings. If you look at your "actions"
4115 file, this would be the section just below the "aliases" section near the top.
4116 This will apply to all URLs as signified by the single forward slash at the end
4117 of the listing -- "/".
4119 But we can define additional actions that would be exceptions to these general
4120 rules, and then list specific URLs (or patterns) that these exceptions would
4121 apply to. Last match wins. Just below this then are two explicit matches for
4122 ".google.com". The first is negating our previous cookie setting, which was for
4123 "+session-cookies-only" (i.e. not persistent). So we will allow persistent
4124 cookies for google. The second turns off any "+fast-redirects" action, allowing
4125 this to take place unmolested. Note that there is a leading dot here --
4126 ".google.com". This will match any hosts and sub-domains, in the google.com
4127 domain also, such as "www.google.com". So, apparently, we have these two
4128 actions defined somewhere in the lower part of our default.action file, and
4129 "google.com" is referenced somewhere in these latter sections.
4131 Then, for our user.action file, we again have no hits.
4133 And finally we pull it all together in the bottom section and summarize how
4134 Privoxy is applying all its "actions" to "google.com":
4140 -crunch-outgoing-cookies
4141 -crunch-incoming-cookies
4142 +deanimate-gifs{last}
4143 -downgrade-http-version
4147 -filter{shockwave-flash}
4148 -filter{crude-parental}
4149 +filter{html-annoyances}
4150 +filter{js-annoyances}
4151 +filter{content-cookies}
4153 +filter{refresh-tags}
4155 +filter{banners-by-size}
4156 +hide-forwarded-for-headers
4157 +hide-from-header{block}
4158 +hide-referer{forge}
4163 +prevent-compression
4166 -session-cookies-only
4167 +set-image-blocker{pattern}
4169 Notice the only difference here to the previous listing, is to "fast-redirects"
4170 and "session-cookies-only".
4172 Now another example, "ad.doubleclick.net":
4174 { +block +handle-as-image }
4177 { +block +handle-as-image }
4180 { +block +handle-as-image }
4183 We'll just show the interesting part here, the explicit matches. It is matched
4184 three different times. Each as an "+block +handle-as-image", which is the
4185 expanded form of one of our aliases that had been defined as: "+imageblock". (
4186 "Aliases" are defined in the first section of the actions file and typically
4187 used to combine more than one action.)
4189 Any one of these would have done the trick and blocked this as an unwanted
4190 image. This is unnecessarily redundant since the last case effectively would
4191 also cover the first. No point in taking chances with these guys though ;-)
4192 Note that if you want an ad or obnoxious URL to be invisible, it should be
4193 defined as "ad.doubleclick.net" is done here -- as both a "+block" and an
4194 "+handle-as-image". The custom alias "+imageblock" just simplifies the process
4195 and make it more readable.
4197 One last example. Let's try "http://www.rhapsodyk.net/adsl/HOWTO/". This one is
4198 giving us problems. We are getting a blank page. Hmmm ...
4200 Matches for http://www.rhapsodyk.net/adsl/HOWTO/:
4202 In file: default.action [ View ] [ Edit ]
4206 -crunch-incoming-cookies
4207 -crunch-outgoing-cookies
4209 -downgrade-http-version
4211 +filter{html-annoyances}
4212 +filter{js-annoyances}
4213 +filter{kill-popups}
4216 +filter{banners-by-size}
4219 +hide-forwarded-for-headers
4220 +hide-from-header{block}
4221 +hide-referer{forge}
4225 +prevent-compression
4228 +session-cookies-only
4229 +set-image-blocker{blank} }
4232 { +block +handle-as-image }
4235 Ooops, the "/adsl/" is matching "/ads"! But we did not want this at all! Now we
4236 see why we get the blank page. We could now add a new action below this that
4237 explicitly does not block ("{-block}") paths with "adsl". There are various
4238 ways to handle such exceptions. Example:
4243 Now the page displays ;-) Be sure to flush your browser's caches when making
4244 such changes. Or, try using Shift+Reload.
4246 But now what about a situation where we get no explicit matches like we did
4249 { +block +handle-as-image }
4252 That actually was very telling and pointed us quickly to where the problem was.
4253 If you don't get this kind of match, then it means one of the default rules in
4254 the first section is causing the problem. This would require some guesswork,
4255 and maybe a little trial and error to isolate the offending rule. One likely
4256 cause would be one of the "{+filter}" actions. These tend to be harder to
4257 troubleshoot. Try adding the URL for the site to one of aliases that turn off
4262 .worldpay.com # for quietpc.com
4267 "{shop}" is an "alias" that expands to "{ -filter -session-cookies-only }". Or
4268 you could do your own exception to negate filtering:
4273 This would turn off all filtering for that site. This would probably be most
4274 appropriately put in user.action, for local site exceptions.
4276 Images that are inexplicably being blocked, may well be hitting the "+filter
4277 {banners-by-size}" rule, which assumes that images of certain sizes are ad
4278 banners (works well most of the time since these tend to be standardized).
4280 "{fragile}" is an alias that disables most actions. This can be used as a last
4281 resort for problem sites. Remember to flush caches! If this still does not
4282 work, you will have to go through the remaining actions one by one to find
4283 which one(s) is causing the problem.
projects / privoxy.git / blob