1 Privoxy 2.9.20 User Manual
3 Copyright © 2001, 2002 by Privoxy Developers
5 $Id: user-manual.sgml,v 1.123.2.16 2002/08/09 19:20:54 david__schmidt 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.2.9.20, 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-2.9.20-1.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-2.9.20-1.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_2.9.20-1.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 file (you can either double-click on the file from the
315 finder, or from the desktop if you downloaded it there). Then, double-click on
316 the package installer icon named Privoxy.pkg and follow the installation
317 process. Privoxy will be installed in the folder /Library/Privoxy. It will
318 start automatically whenever you start up. To prevent it from starting
319 automatically, remove or rename the folder /Library/StartupItems/Privoxy.
321 To start Privoxy by hand, double-click on StartPrivoxy.command in the /Library/
322 Privoxy folder. Or, type this command in the Terminal:
324 /Library/Privoxy/StartPrivoxy.command
327 You will be prompted for the administrator password.
328 -------------------------------------------------------------------------------
332 Copy and then unpack the lha archive to a suitable location. All necessary
333 files will be installed into Privoxy directory, including all configuration and
334 log files. To uninstall, just remove this directory.
335 -------------------------------------------------------------------------------
339 Gentoo source packages (Ebuilds) for Privoxy are contained in the Gentoo
340 Portage Tree (they are not on the download page, but there is a Gentoo section,
341 where you can see when a new Privoxy Version is added to the Portage Tree).
343 Before installing Privoxy under Gentoo just do first emerge rsync to get the
344 latest changes from the Portage tree. With emerge privoxy you install the
347 Configuration files are in /etc/privoxy, the documentation is in /usr/share/doc
348 /privoxy-2.9.20 and the Log directory is in /var/log/privoxy.
349 -------------------------------------------------------------------------------
351 2.2. Building from Source
353 The most convenient way to obtain the Privoxy sources is to download the source
354 tarball from our project page.
356 If you like to live on the bleeding edge and are not afraid of using possibly
357 unstable development versions, you can check out the up-to-the-minute version
358 directly from the CVS repository or simply download the nightly CVS tarball.
360 To build Privoxy from source, autoconf, GNU make (gmake), and, of course, a C
361 compiler like gcc are required.
363 When building from a source tarball (either release version or nightly CVS
364 tarball), first unpack the source:
366 tar xzvf privoxy-2.9.20-beta-src* [.tgz or .tar.gz]
367 cd privoxy-2.9.20-beta
369 For retrieving the current CVS sources, you'll need CVS installed. Note that
370 sources from CVS are development quality, and may not be stable, or well
371 tested. To download CVS source:
373 cvs -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa login
374 cvs -z3 -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa co current
377 This will create a directory named current/, which will contain the source
380 Then, in either case, to build from unpacked tarball or CVS source:
384 ./configure # (--help to see options)
385 make # (the make from gnu, gmake for *BSD)
387 make -n install # (to see where all the files will go)
388 make install # (to really install)
390 If you have gnu make, you can have the first four steps automatically done for
395 in the freshly downloaded or unpacked source directory.
397 For more detailed instructions on how to build Redhat and SuSE RPMs, Windows
398 self-extracting installers, building on platforms with special requirements
399 etc, please consult the developer manual.
400 -------------------------------------------------------------------------------
402 2.3. Keeping your Installation Up-to-Date
404 As user feedback comes in and development continues, we will make updated
405 versions of both the main actions file (as a separate package) and the software
406 itself (including the actions file) available for download.
408 If you wish to receive an email notification whenever we release updates of
409 Privoxy or the actions file, subscribe to our announce mailing list,
410 ijbswa-announce@lists.sourceforge.net.
412 In order not to loose your personal changes and adjustments when updating to
413 the latest default.action file we strongly recommend that you use user.action
414 for your customization of Privoxy. See the Chapter on actions files for
416 -------------------------------------------------------------------------------
420 There are very significant changes from earlier Junkbuster versions to the
421 current Privoxy. The number, names, syntax, and purposes of configuration files
422 have substantially changed. Junkbuster 2.0.x configuration files will not
423 migrate, Junkbuster 2.9.x and Privoxy configurations will need to be ported.
424 The functionalities of the old blockfile, cookiefile and imagelist are now
425 combined into the "actions files". default.action, is the main actions file.
426 Local exceptions should best be put into user.action.
428 A "filter file" (typically default.filter) is new as of Privoxy 2.9.x, and
429 provides some of the new sophistication (explained below). config is much the
432 If upgrading from a 2.0.x version, you will have to use the new config files,
433 and possibly adapt any personal rules from your older files. When porting
434 personal rules over from the old blockfile to the new actions files, please
435 note that even the pattern syntax has changed. If upgrading from 2.9.x
436 development versions, it is still recommended to use the new configuration
439 A quick list of things to be aware of before upgrading:
441 * The default listening port is now 8118 due to a conflict with another
444 * Some installers may remove earlier versions completely. Save any important
447 * Privoxy is controllable with a web browser at the special URL: http://
448 config.privoxy.org/ (Shortcut: http://p.p/). Many aspects of configuration
449 can be done here, including temporarily disabling Privoxy.
451 * The primary configuration files for cookie management, ad and banner
452 blocking, and many other aspects of Privoxy configuration are the actions
453 files. It is strongly recommended to become familiar with the new actions
454 concept below, before modifying these files. Locally defined rules should
457 * Some installers may not automatically start Privoxy after installation.
460 -------------------------------------------------------------------------------
461 4. Quickstart to Using Privoxy
463 * If upgrading, from versions before 2.9.16, please back up any configuration
464 files. See the Note to Upgraders Section.
466 * Install Privoxy. See the Installation Section below for platform specific
469 * Advanced users and those who want to offer Privoxy service to more than
470 just their local machine should check the main config file, especially the
471 security-relevant options. These are off by default.
473 * Start Privoxy, if the installation program has not done this already (may
474 vary according to platform). See the section Starting Privoxy.
476 * Set your browser to use Privoxy as HTTP and HTTPS proxy by setting the
477 proxy configuration for address of 127.0.0.1 and port 8118. (Junkbuster and
478 earlier versions of Privoxy used port 8000.) See the section Starting
479 Privoxy below for more details on this.
481 * Flush your browser's disk and memory caches, to remove any cached ad
484 * A default installation should provide a reasonable starting point for most.
485 There will undoubtedly be occasions where you will want to adjust the
486 configuration, but that can be dealt with as the need arises. Little to no
487 initial configuration is required in most cases.
489 See the Configuration section for more configuration options, and how to
490 customize your installation.
492 * If you experience ads that slipped through, innocent images that are
493 blocked, or otherwise feel the need to fine-tune Privoxy's behaviour, take
494 a look at the actions files. As a quick start, you might find the richly
495 commented examples helpful. You can also view and edit the actions files
496 through the web-based user interface. The Appendix "Anatomy of an Action"
497 has hints how to debug actions that "misbehave".
499 * Please see the section Contacting the Developers on how to report bugs or
500 problems with websites or to get help.
502 * Now enjoy surfing with enhanced comfort and privacy!
505 -------------------------------------------------------------------------------
506 4.1. Quickstart to Ad Blocking
508 Ad blocking is but one of Privoxy's array of features. Many of these features
509 are for the technically minded advanced user. But, ad and banner blocking is
510 surely common ground for everybody.
512 This section will provide a quick summary of ad blocking so you can get up to
513 speed quickly without having to read the more extensive information provided
514 below, though this is highly recommended.
516 First a bit of a warning ... blocking ads is much like blocking SPAM: the more
517 aggressive you are about it, the more likely you are to block things that were
518 not intended. So there is a trade off here. If you want extreme ad free
519 browsing, be prepared to deal with more "problem" sites, and to spend more time
520 adjusting the configuration to solve these unintended consequences. In short,
521 there is not an easy way to eliminate all ads. Either take the easy way and
522 settle for most ads blocked with the default configuration, or jump in and
523 tweak it for your personal surfing habits and preferences.
525 Secondly, a brief explanation of Privoxy's "actions". "Actions" in this
526 context, are the directives we use to tell Privoxy to perform some task
527 relating to HTTP transactions (i.e. web browsing). We tell Privoxy to take some
528 "action". Each action has a unique name and function. While there are many
529 potential actions in Privoxy's arsenal, only a few are used for ad blocking.
530 Actions, and action configuration files, are explained in depth below.
532 Actions are specified in Privoxy's configuration, followed by one or more URLs
533 to which the action should apply. URLs can actually be URL type patterns that
534 use wildcards so they can apply potentially to a range of similar URLs. The
535 actions, together with the URL patterns are called a section.
537 When you connect to a website, the full URL will either match one or more of
538 the sections as defined in Privoxy's configuration, or not. If so, then Privoxy
539 will perform the respective actions. If not, then nothing special happens.
540 Furthermore, web pages may contain embedded, secondary URLs that your web
541 browser will use to load additional components of the page, as it parses the
542 original page's HTML content. An ad image for instance, is just an URL embedded
543 in the page somewhere. The image itself may be on the same server, or a server
544 somewhere else on the Internet. Complex web pages will have many such embedded
547 The actions we need to know about for ad blocking are: block, handle-as-image,
548 and set-image-blocker:
550 * block - this action stops any contact between your browser and any URL
551 patterns that match this action's configuration. It can be used for
552 blocking ads, but also anything that is determined to be unwanted. By
553 itself, it simply stops any communication with the remote server and sends
554 Privoxy's own built-in BLOCKED page instead to let you now what has
557 * handle-as-image - tells Privoxy to treat this URL as an image. Privoxy's
558 default configuration already does this for all common image types (e.g.
559 GIF), but there are many situations where this is not so easy to determine.
560 So we'll force it in these cases. This is particularly important for ad
561 blocking, since only if we know that it's an image of some kind, can we
562 replace it with an image of our choosing, instead of the Privoxy BLOCKED
563 page (which would only result in a "broken image" icon). There are some
564 limitations to this though. For instance, you can't just brute-force an
565 image substitution for an entire HTML page in most situations.
567 * set-image-blocker - tells Privoxy what to display in place of an ad image
568 that has hit a block rule. For this to come into play, the URL must match a
569 block action somewhere in the configuration, and, it must also match an
570 handle-as-image action.
572 The configuration options on what to display instead of the ad are:
574 pattern - a checkerboard pattern, so that an ad replacement is obvious.
577 blank - A very small empty GIF image is displayed. This is the so-called
578 "invisible" configuration option.
580 http://<URL> - A redirect to any image anywhere of the user's choosing
585 The quickest way to adjust any of these settings is with your browser through
586 the special Privoxy editor at http://config.privoxy.org/show-status (shortcut:
587 http://p.p/show-status). This is an internal page, and does not require
588 Internet access. Select the appropriate "actions" file, and click "Edit". It is
589 best to put personal or local preferences in user.action since this is not
590 meant to be overwritten during upgrades, and will over-ride the settings in
591 other files. Here you can insert new "actions", and URLs for ad blocking or
592 other purposes, and make other adjustments to the configuration. Privoxy will
593 detect these changes automatically.
595 A quick and simple step by step example:
597 * Right click on the ad image to be blocked, then select "Copy Link Location"
598 from the pop-up menu.
600 * Set your browser to http://config.privoxy.org/show-status
602 * Find user.action in the top section, and click on "Edit":
604 Figure 1. Actions Files in Use
606 [ Screenshot of Actions Files in Use ]
608 * You should have a section with only block listed under "Actions:". If not,
609 click a "Insert new section below" button, and in the new section that just
610 appeared, click the Edit button right under the word "Actions:". This will
611 bring up a list of all actions. Find block near the top, and click in the
612 "Enabled" column, then "Submit" just below the list.
614 * Now, in the block actions section, click the "Add" button, and paste the
615 URL the browser got from "Copy Link Location". Remove the http:// at the
616 beginning of the URL. Then, click "Submit" (or "OK" if in a pop-up window).
618 * Now go back to the original page, and press SHIFT-Reload (or flush all
619 browser caches). The image should be gone now.
622 This is a very crude and simple example. There might be good reasons to use a
623 wildcard pattern match to include potentially similar images from the same
624 site. For a more extensive explanation of "patterns", and the entire actions
625 concept, see the Actions section.
627 For advanced users who want to hand edit their config files, you might want to
628 now go to the Actions Files Tutorial. The ideas explained therein also apply to
629 the web-based editor.
630 -------------------------------------------------------------------------------
634 Before launching Privoxy for the first time, you will want to configure your
635 browser(s) to use Privoxy as a HTTP and HTTPS proxy. The default is 127.0.0.1
636 (or localhost) for the proxy address, and port 8118 (earlier versions used port
637 8000). This is the one configuration step that must be done!
639 Please note that Privoxy can only proxy HTTP and HTTPS traffic. It will not
640 work with FTP or other protocols.
642 Figure 2. Proxy Configuration (Mozilla)
644 [ Screenshot of Mozilla Proxy Configuration ]
646 With Netscape (and Mozilla), this can be set under:
658 For Internet Explorer:
668 Then, check "Use Proxy" and fill in the appropriate info (Address: 127.0.0.1,
669 Port: 8118). Include HTTPS (SSL), if you want HTTPS proxy support too.
671 After doing this, flush your browser's disk and memory caches to force a
672 re-reading of all pages and to get rid of any ads that may be cached. You are
673 now ready to start enjoying the benefits of using Privoxy!
675 Privoxy is typically started by specifying the main configuration file to be
676 used on the command line. If no configuration file is specified on the command
677 line, Privoxy will look for a file named config in the current directory.
678 Except on Win32 where it will try config.txt.
679 -------------------------------------------------------------------------------
681 5.1. Red Hat and Conectiva
683 We use a script. Note that Red Hat does not start Privoxy upon booting per
684 default. It will use the file /etc/privoxy/config as its main configuration
687 # /etc/rc.d/init.d/privoxy start
688 -------------------------------------------------------------------------------
692 We use a script. Note that Debian starts Privoxy upon booting per default. It
693 will use the file /etc/privoxy/config as its main configuration file.
695 # /etc/init.d/privoxy start
696 -------------------------------------------------------------------------------
700 We use a script. It will use the file /etc/privoxy/config as its main
701 configuration file. Note that SuSE starts Privoxy upon booting your PC.
704 -------------------------------------------------------------------------------
708 Click on the Privoxy Icon to start Privoxy. If no configuration file is
709 specified on the command line, Privoxy will look for a file named config.txt.
710 Note that Windows will automatically start Privoxy upon booting you PC.
711 -------------------------------------------------------------------------------
713 5.5. Solaris, NetBSD, FreeBSD, HP-UX and others
715 Example Unix startup command:
717 # /usr/sbin/privoxy /etc/privoxy/config
718 -------------------------------------------------------------------------------
722 During installation, Privoxy is configured to start automatically when the
723 system restarts. You can start it manually by double-clicking on the Privoxy
724 icon in the Privoxy folder.
725 -------------------------------------------------------------------------------
729 During installation, Privoxy is configured to start automatically when the
730 system restarts. To start Privoxy by hand, double-click on the
731 StartPrivoxy.command icon in the /Library/Privoxy folder. Or, type this command
734 /Library/Privoxy/StartPrivoxy.command
737 You will be prompted for the administrator password.
738 -------------------------------------------------------------------------------
742 Start Privoxy (with RUN <>NIL:) in your startnet script (AmiTCP), in s:
743 user-startup (RoadShow), as startup program in your startup script (Genesis),
744 or as startup action (Miami and MiamiDx). Privoxy will automatically quit when
745 you quit your TCP/IP stack (just ignore the harmless warning your TCP/IP stack
746 may display that Privoxy is still running).
747 -------------------------------------------------------------------------------
751 A script is again used. It will use the file /etc/privoxy/config as its main
754 /etc/init.d/privoxy start
757 Note that Privoxy is not automatically started at boot time by default. You can
758 change this with the rc-update command.
760 rc-update add privoxy default
762 -------------------------------------------------------------------------------
764 5.10. Command Line Options
766 Privoxy may be invoked with the following command-line options:
770 Print version info and exit. Unix only.
774 Print short usage info and exit. Unix only.
778 Don't become a daemon, i.e. don't fork and become process group leader, and
779 don't detach from controlling tty. Unix only.
783 On startup, write the process ID to FILE. Delete the FILE on exit. Failure
784 to create or delete the FILE is non-fatal. If no FILE option is given, no
785 PID file will be used. Unix only.
787 * --user USER[.GROUP]
789 After (optionally) writing the PID file, assume the user ID of USER, and if
790 included the GID of GROUP. Exit if the privileges are not sufficient to do
795 If no configfile is included on the command line, Privoxy will look for a
796 file named "config" in the current directory (except on Win32 where it will
797 look for "config.txt" instead). Specify full path to avoid confusion. If no
798 config file is found, Privoxy will fail to start.
801 -------------------------------------------------------------------------------
802 6. Privoxy Configuration
804 All Privoxy configuration is stored in text files. These files can be edited
805 with a text editor. Many important aspects of Privoxy can also be controlled
806 easily with a web browser.
807 -------------------------------------------------------------------------------
809 6.1. Controlling Privoxy with Your Web Browser
811 Privoxy's user interface can be reached through the special URL http://
812 config.privoxy.org/ (shortcut: http://p.p/), which is a built-in page and works
813 without Internet access. You will see the following section:
815 ?? View & change the current configuration
816 ?? View the source code version numbers
817 ?? View the request headers.
818 ?? Look up which actions apply to a URL and why
819 ?? Toggle Privoxy on or off
821 This should be self-explanatory. Note the first item leads to an editor for the
822 actions files, which is where the ad, banner, cookie, and URL blocking magic is
823 configured as well as other advanced features of Privoxy. This is an easy way
824 to adjust various aspects of Privoxy configuration. The actions file, and other
825 configuration files, are explained in detail below.
827 "Toggle Privoxy On or Off" is handy for sites that might have problems with
828 your current actions and filters. You can in fact use it as a test to see
829 whether it is Privoxy causing the problem or not. Privoxy continues to run as a
830 proxy in this case, but all manipulation is disabled, i.e. Privoxy acts like a
831 normal forwarding proxy. There is even a toggle Bookmarklet offered, so that
832 you can toggle Privoxy with one click from your browser.
833 -------------------------------------------------------------------------------
835 6.2. Configuration Files Overview
837 For Unix, *BSD and Linux, all configuration files are located in /etc/privoxy/
838 by default. For MS Windows, OS/2, and AmigaOS these are all in the same
839 directory as the Privoxy executable. The name and number of configuration files
840 has changed from previous versions, and is subject to change as development
843 The installed defaults provide a reasonable starting point, though some
844 settings may be aggressive by some standards. For the time being, the principle
845 configuration files are:
847 * The main configuration file is named config on Linux, Unix, BSD, OS/2, and
848 AmigaOS and config.txt on Windows. This is a required file.
850 * default.action (the main actions file) is used to define which "actions"
851 relating to banner-blocking, images, pop-ups, content modification, cookie
852 handling etc should be applied by default. It also defines many exceptions
853 (both positive and negative) from this default set of actions that enable
854 Privoxy to selectively eliminate the junk, and only the junk, on as many
855 websites as possible.
857 Multiple actions files may be defined in config. These are processed in the
858 order they are defined. Local customizations and locally preferred
859 exceptions to the default policies as defined in default.action (which you
860 will most probably want to define sooner or later) are probably best
861 applied in user.action, where you can preserve them across upgrades.
862 standard.action is for Privoxy's internal use.
864 There is also a web based editor that can be accessed from http://
865 config.privoxy.org/show-status (Shortcut: http://p.p/show-status) for the
866 various actions files.
868 * default.filter (the filter file) can be used to re-write the raw page
869 content, including viewable text as well as embedded HTML and JavaScript,
870 and whatever else lurks on any given web page. The filtering jobs are only
871 pre-defined here; whether to apply them or not is up to the actions files.
874 All files use the "#" character to denote a comment (the rest of the line will
875 be ignored) and understand line continuation through placing a backslash ("\")
876 as the very last character in a line. If the # is preceded by a backslash, it
877 looses its special function. Placing a # in front of an otherwise valid
878 configuration line to prevent it from being interpreted is called "commenting
881 The actions files and default.filter can use Perl style regular expressions for
884 After making any changes, there is no need to restart Privoxy in order for the
885 changes to take effect. Privoxy detects such changes automatically. Note,
886 however, that it may take one or two additional requests for the change to take
887 effect. When changing the listening address of Privoxy, these "wake up"
888 requests must obviously be sent to the old listening address.
890 While under development, the configuration content is subject to change. The
891 below documentation may not be accurate by the time you read this. Also, what
892 constitutes a "default" setting, may change, so please check all your
893 configuration files on important issues.
894 -------------------------------------------------------------------------------
896 7. The Main Configuration File
898 Again, the main configuration file is named config on Linux/Unix/BSD and OS/2,
899 and config.txt on Windows. Configuration lines consist of an initial keyword
900 followed by a list of values, all separated by whitespace (any number of spaces
901 or tabs). For example:
905 Assigns the value /etc/privoxy to the option confdir and thus indicates that
906 the configuration directory is named "/etc/privoxy/".
908 All options in the config file except for confdir and logdir are optional.
909 Watch out in the below description for what happens if you leave them unset.
911 The main config file controls all aspects of Privoxy's operation that are not
912 location dependent (i.e. they apply universally, no matter where you may be
914 -------------------------------------------------------------------------------
916 7.1. Configuration and Log File Locations
918 Privoxy can (and normally does) use a number of other files for additional
919 configuration, help and logging. This section of the configuration file tells
920 Privoxy where to find those other files.
922 The user running Privoxy, must have read permission for all configuration
923 files, and write permission to any files that would be modified, such as log
924 files and actions files.
925 -------------------------------------------------------------------------------
930 The directory where the other configuration files are located
936 /etc/privoxy (Unix) or Privoxy installation dir (Windows)
942 No trailing "/", please
944 When development goes modular and multi-user, the blocker, filter, and
945 per-user config will be stored in subdirectories of "confdir". For now, the
946 configuration directory structure is flat, except for confdir/templates,
947 where the HTML templates for CGI output reside (e.g. Privoxy's 404 error
951 -------------------------------------------------------------------------------
955 The directory where all logging takes place (i.e. where logfile and jarfile
962 /var/log/privoxy (Unix) or Privoxy installation dir (Windows)
968 No trailing "/", please
971 -------------------------------------------------------------------------------
975 The actions file(s) to use
978 File name, relative to confdir, without the .action suffix
981 standard # Internal purposes, no editing recommended
982 default # Main actions file
983 user # User customizations
987 No actions are taken at all. Simple neutral proxying.
990 Multiple actionsfile lines are permitted, and are in fact recommended!
992 The default values include standard.action, which is used for internal
993 purposes and should be loaded, default.action, which is the "main" actions
994 file maintained by the developers, and user.action, where you can make your
997 Actions files are where all the per site and per URL configuration is done
998 for ad blocking, cookie management, privacy considerations, etc. There is
999 no point in using Privoxy without at least one actions file.
1002 -------------------------------------------------------------------------------
1006 The filter file to use
1009 File name, relative to confdir
1012 default.filter (Unix) or default.filter.txt (Windows)
1015 No textual content filtering takes place, i.e. all +filter{name} actions in
1016 the actions files are turned neutral.
1019 The filter file contains content modification rules that use regular
1020 expressions. These rules permit powerful changes on the content of Web
1021 pages, e.g., you could disable your favorite JavaScript annoyances,
1022 re-write the actual displayed text, or just have some fun replacing
1023 "Microsoft" with "MicroSuck" wherever it appears on a Web page.
1025 The +filter{name} actions rely on the relevant filter (name) to be defined
1028 A pre-defined filter file called default.filter that contains a bunch of
1029 handy filters for common problems is included in the distribution. See the
1030 section on the filter action for a list.
1033 -------------------------------------------------------------------------------
1040 File name, relative to logdir
1043 logfile (Unix) or privoxy.log (Windows)
1046 No log file is used, all log messages go to the console (STDERR).
1049 The windows version will additionally log to the console.
1051 The logfile is where all logging and error messages are written. The level
1052 of detail and number of messages are set with the debug option (see below).
1053 The logfile can be useful for tracking down a problem with Privoxy (e.g.,
1054 it's not blocking an ad you think it should block) but in most cases you
1055 probably will never look at it.
1057 Your logfile will grow indefinitely, and you will probably want to
1058 periodically remove it. On Unix systems, you can do this with a cron job
1059 (see "man cron"). For Red Hat, a logrotate script has been included.
1061 On SuSE Linux systems, you can place a line like "/var/log/privoxy.* +1024k
1062 644 nobody.nogroup" in /etc/logfiles, with the effect that cron.daily will
1063 automatically archive, gzip, and empty the log, when it exceeds 1M size.
1065 Any log files must be writable by whatever user Privoxy is being run as
1066 (default on UNIX, user id is "privoxy").
1069 -------------------------------------------------------------------------------
1073 The file to store intercepted cookies in
1076 File name, relative to logdir
1079 jarfile (Unix) or privoxy.jar (Windows)
1082 Intercepted cookies are not stored at all.
1085 The jarfile may grow to ridiculous sizes over time.
1088 -------------------------------------------------------------------------------
1092 The trust file to use
1095 File name, relative to confdir
1098 Unset (commented out). When activated: trust (Unix) or trust.txt (Windows)
1101 The whole trust mechanism is turned off.
1104 The trust mechanism is an experimental feature for building white-lists and
1105 should be used with care. It is NOT recommended for the casual user.
1107 If you specify a trust file, Privoxy will only allow access to sites that
1108 are named in the trustfile. You can also mark sites as trusted referrers
1109 (with +), with the effect that access to untrusted sites will be granted,
1110 if a link from a trusted referrer was used. The link target will then be
1111 added to the "trustfile". Possible applications include limiting Internet
1112 access for children.
1114 If you use + operator in the trust file, it may grow considerably over
1118 -------------------------------------------------------------------------------
1119 7.2. Local Set-up Documentation
1121 If you intend to operate Privoxy for more users than just yourself, it might be
1122 a good idea to let them know how to reach you, what you block and why you do
1123 that, your policies, etc.
1124 -------------------------------------------------------------------------------
1129 Location of the Privoxy User Manual.
1132 A fully qualified URI
1138 http://www.privoxy.org/version/user-manual/ will be used, where version is
1139 the Privoxy version.
1142 The User Manual URI is used for help links from some of the internal CGI
1143 pages. The manual itself is normally packaged with the binary
1144 distributions, so you probably want to set this to a locally installed
1145 copy. For multi-user setups, you could provide a copy on a local webserver
1146 for all your users and use the corresponding URL here.
1150 Unix, in local filesystem:
1152 user-manual file:///usr/share/doc/privoxy-2.9.20/user-manual/
1154 Any platform, on local webserver (called "local-webserver"):
1156 user-manual http://local-webserver/privoxy-user-manual/
1158 +-----------------------------------------------------------------+
1160 +-----------------------------------------------------------------+
1161 |If set, this option should be the first option in the config |
1162 |file, because it is used while the config file is being read. |
1163 +-----------------------------------------------------------------+
1166 -------------------------------------------------------------------------------
1167 7.2.2. trust-info-url
1170 A URL to be displayed in the error page that users will see if access to an
1171 untrusted page is denied.
1177 Two example URL are provided
1180 No links are displayed on the "untrusted" error page.
1183 The value of this option only matters if the experimental trust mechanism
1184 has been activated. (See trustfile above.)
1186 If you use the trust mechanism, it is a good idea to write up some on-line
1187 documentation about your trust policy and to specify the URL(s) here. Use
1188 multiple times for multiple URLs.
1190 The URL(s) should be added to the trustfile as well, so users don't end up
1191 locked out from the information on why they were locked out in the first
1195 -------------------------------------------------------------------------------
1196 7.2.3. admin-address
1199 An email address to reach the proxy administrator.
1208 No email address is displayed on error pages and the CGI user interface.
1211 If both admin-address and proxy-info-url are unset, the whole "Local
1212 Privoxy Support" box on all generated pages will not be shown.
1215 -------------------------------------------------------------------------------
1216 7.2.4. proxy-info-url
1219 A URL to documentation about the local Privoxy setup, configuration or
1229 No link to local documentation is displayed on error pages and the CGI user
1233 If both admin-address and proxy-info-url are unset, the whole "Local
1234 Privoxy Support" box on all generated pages will not be shown.
1236 This URL shouldn't be blocked ;-)
1239 -------------------------------------------------------------------------------
1242 These options are mainly useful when tracing a problem. Note that you might
1243 also want to invoke Privoxy with the --no-daemon command line option when
1245 -------------------------------------------------------------------------------
1250 Key values that determine what information gets logged to the logfile.
1256 12289 (i.e.: URLs plus informational and warning messages)
1259 Nothing gets logged.
1262 The available debug levels are:
1264 debug 1 # show each GET/POST/CONNECT request
1265 debug 2 # show each connection status
1266 debug 4 # show I/O status
1267 debug 8 # show header parsing
1268 debug 16 # log all data into the logfile
1269 debug 32 # debug force feature
1270 debug 64 # debug regular expression filter
1271 debug 128 # debug fast redirects
1272 debug 256 # debug GIF de-animation
1273 debug 512 # Common Log Format
1274 debug 1024 # debug kill pop-ups
1275 debug 2048 # CGI user interface
1276 debug 4096 # Startup banner and warnings.
1277 debug 8192 # Non-fatal errors
1279 To select multiple debug levels, you can either add them or use multiple
1282 A debug level of 1 is informative because it will show you each request as
1283 it happens. 1, 4096 and 8192 are highly recommended so that you will notice
1284 when things go wrong. The other levels are probably only of interest if you
1285 are hunting down a specific problem. They can produce a hell of an output
1288 The reporting of fatal errors (i.e. ones which crash Privoxy) is always on
1289 and cannot be disabled.
1291 If you want to use CLF (Common Log Format), you should set "debug 512" ONLY
1292 and not enable anything else.
1295 -------------------------------------------------------------------------------
1296 7.3.2. single-threaded
1299 Whether to run only one server thread
1308 Multi-threaded (or, where unavailable: forked) operation, i.e. the ability
1309 to serve multiple requests simultaneously.
1312 This option is only there for debug purposes and you should never need to
1313 use it. It will drastically reduce performance.
1316 -------------------------------------------------------------------------------
1317 7.4. Access Control and Security
1319 This section of the config file controls the security-relevant aspects of
1320 Privoxy's configuration.
1321 -------------------------------------------------------------------------------
1323 7.4.1. listen-address
1326 The IP address and TCP port on which Privoxy will listen for client
1336 Bind to 127.0.0.1 (localhost), port 8118. This is suitable and recommended
1337 for home users who run Privoxy on the same machine as their browser.
1340 You will need to configure your browser(s) to this proxy address and port.
1342 If you already have another service running on port 8118, or if you want to
1343 serve requests from other machines (e.g. on your local network) as well,
1344 you will need to override the default.
1346 If you leave out the IP address, Privoxy will bind to all interfaces
1347 (addresses) on your machine and may become reachable from the Internet. In
1348 that case, consider using access control lists (ACL's, see below), and/or a
1351 If you open Privoxy to untrusted users, you will also want to turn off the
1352 enable-edit-actions and enable-remote-toggle options!
1355 Suppose you are running Privoxy on a machine which has the address
1356 192.168.0.1 on your local private network (192.168.0.0) and has another
1357 outside connection with a different address. You want it to serve requests
1360 listen-address 192.168.0.1:8118
1363 -------------------------------------------------------------------------------
1367 Initial state of "toggle" status
1376 Act as if toggled on
1379 If set to 0, Privoxy will start in "toggled off" mode, i.e. behave like a
1380 normal, content-neutral proxy where all ad blocking, filtering, etc are
1381 disabled. See enable-remote-toggle below. This is not really useful
1382 anymore, since toggling is much easier via the web interface than via
1383 editing the conf file.
1385 The windows version will only display the toggle icon in the system tray if
1386 this option is present.
1389 -------------------------------------------------------------------------------
1390 7.4.3. enable-remote-toggle
1393 Whether or not the web-based toggle feature may be used
1402 The web-based toggle feature is disabled.
1405 When toggled off, Privoxy acts like a normal, content-neutral proxy, i.e.
1406 it acts as if none of the actions applied to any URL.
1408 For the time being, access to the toggle feature can not be controlled
1409 separately by "ACLs" or HTTP authentication, so that everybody who can
1410 access Privoxy (see "ACLs" and listen-address above) can toggle it for all
1411 users. So this option is not recommended for multi-user environments with
1414 Note that you must have compiled Privoxy with support for this feature,
1415 otherwise this option has no effect.
1418 -------------------------------------------------------------------------------
1419 7.4.4. enable-edit-actions
1422 Whether or not the web-based actions file editor may be used
1431 The web-based actions file editor is disabled.
1434 For the time being, access to the editor can not be controlled separately
1435 by "ACLs" or HTTP authentication, so that everybody who can access Privoxy
1436 (see "ACLs" and listen-address above) can modify its configuration for all
1437 users. So this option is not recommended for multi-user environments with
1440 Note that you must have compiled Privoxy with support for this feature,
1441 otherwise this option has no effect.
1444 -------------------------------------------------------------------------------
1445 7.4.5. ACLs: permit-access and deny-access
1448 Who can access what.
1451 src_addr[/src_masklen] [dst_addr[/dst_masklen]]
1453 Where src_addr and dst_addr are IP addresses in dotted decimal notation or
1454 valid DNS names, and src_masklen and dst_masklen are subnet masks in CIDR
1455 notation, i.e. integer values from 2 to 30 representing the length (in
1456 bits) of the network address. The masks and the whole destination part are
1463 Don't restrict access further than implied by listen-address
1466 Access controls are included at the request of ISPs and systems
1467 administrators, and are not usually needed by individual users. For a
1468 typical home user, it will normally suffice to ensure that Privoxy only
1469 listens on the localhost (127.0.0.1) or internal (home) network address by
1470 means of the listen-address option.
1472 Please see the warnings in the FAQ that this proxy is not intended to be a
1473 substitute for a firewall or to encourage anyone to defer addressing basic
1474 security weaknesses.
1476 Multiple ACL lines are OK. If any ACLs are specified, then the Privoxy
1477 talks only to IP addresses that match at least one permit-access line and
1478 don't match any subsequent deny-access line. In other words, the last match
1479 wins, with the default being deny-access.
1481 If Privoxy is using a forwarder (see forward below) for a particular
1482 destination URL, the dst_addr that is examined is the address of the
1483 forwarder and NOT the address of the ultimate target. This is necessary
1484 because it may be impossible for the local Privoxy to determine the IP
1485 address of the ultimate target (that's often what gateways are used for).
1487 You should prefer using IP addresses over DNS names, because the address
1488 lookups take time. All DNS names must resolve! You can not use domain
1489 patterns like "*.org" or partial domain names. If a DNS name resolves to
1490 multiple IP addresses, only the first one is used.
1492 Denying access to particular sites by ACL may have undesired side effects
1493 if the site in question is hosted on a machine which also hosts other
1497 Explicitly define the default behavior if no ACL and listen-address are
1498 set: "localhost" is OK. The absence of a dst_addr implies that all
1499 destination addresses are OK:
1501 permit-access localhost
1503 Allow any host on the same class C subnet as www.privoxy.org access to
1504 nothing but www.example.com:
1506 permit-access www.privoxy.org/24 www.example.com/32
1508 Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere,
1509 with the exception that 192.168.45.73 may not access
1510 www.dirty-stuff.example.com:
1512 permit-access 192.168.45.64/26
1513 deny-access 192.168.45.73 www.dirty-stuff.example.com
1516 -------------------------------------------------------------------------------
1520 Maximum size of the buffer for content filtering.
1529 Use a 4MB (4096 KB) limit.
1532 For content filtering, i.e. the +filter and +deanimate-gif actions, it is
1533 necessary that Privoxy buffers the entire document body. This can be
1534 potentially dangerous, since a server could just keep sending data
1535 indefinitely and wait for your RAM to exhaust -- with nasty consequences.
1538 When a document buffer size reaches the buffer-limit, it is flushed to the
1539 client unfiltered and no further attempt to filter the rest of the document
1540 is made. Remember that there may be multiple threads running, which might
1541 require up to buffer-limit Kbytes each, unless you have enabled
1542 "single-threaded" above.
1545 -------------------------------------------------------------------------------
1548 This feature allows routing of HTTP requests through a chain of multiple
1549 proxies. It can be used to better protect privacy and confidentiality when
1550 accessing specific domains by routing requests to those domains through an
1551 anonymous public proxy (see e.g. http://www.multiproxy.org/anon_list.htm) Or to
1552 use a caching proxy to speed up browsing. Or chaining to a parent proxy may be
1553 necessary because the machine that Privoxy runs on has no direct Internet
1556 Also specified here are SOCKS proxies. Privoxy supports the SOCKS 4 and SOCKS
1558 -------------------------------------------------------------------------------
1563 To which parent HTTP proxy specific requests should be routed.
1566 target_pattern http_parent[:port]
1568 where target_pattern is a URL pattern that specifies to which requests
1569 (i.e. URLs) this forward rule shall apply. Use / to denote "all URLs".
1570 http_parent[:port] is the DNS name or IP address of the parent HTTP proxy
1571 through which the requests should be forwarded, optionally followed by its
1572 listening port (default: 8080). Use a single dot (.) to denote "no
1579 Don't use parent HTTP proxies.
1582 If http_parent is ".", then requests are not forwarded to another HTTP
1583 proxy but are made directly to the web servers.
1585 Multiple lines are OK, they are checked in sequence, and the last match
1589 Everything goes to an example anonymizing proxy, except SSL on port 443
1590 (which it doesn't handle):
1592 forward / anon-proxy.example.org:8080
1595 Everything goes to our example ISP's caching proxy, except for requests to
1598 forward / caching-proxy.example-isp.net:8000
1599 forward .example-isp.net .
1602 -------------------------------------------------------------------------------
1603 7.5.2. forward-socks4 and forward-socks4a
1606 Through which SOCKS proxy (and to which parent HTTP proxy) specific
1607 requests should be routed.
1610 target_pattern socks_proxy[:port] http_parent[:port]
1612 where target_pattern is a URL pattern that specifies to which requests
1613 (i.e. URLs) this forward rule shall apply. Use / to denote "all URLs".
1614 http_parent and socks_proxy are IP addresses in dotted decimal notation or
1615 valid DNS names (http_parent may be "." to denote "no HTTP forwarding"),
1616 and the optional port parameters are TCP ports, i.e. integer values from 1
1623 Don't use SOCKS proxies.
1626 Multiple lines are OK, they are checked in sequence, and the last match
1629 The difference between forward-socks4 and forward-socks4a is that in the
1630 SOCKS 4A protocol, the DNS resolution of the target hostname happens on the
1631 SOCKS server, while in SOCKS 4 it happens locally.
1633 If http_parent is ".", then requests are not forwarded to another HTTP
1634 proxy but are made (HTTP-wise) directly to the web servers, albeit through
1638 From the company example.com, direct connections are made to all "internal"
1639 domains, but everything outbound goes through their ISP's proxy by way of
1640 example.com's corporate SOCKS 4A gateway to the Internet.
1642 forward-socks4a / socks-gw.example.com:1080 www-cache.example-isp.net:8080
1643 forward .example.com .
1645 A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent
1648 forward-socks4 / socks-gw.example.com:1080 .
1651 -------------------------------------------------------------------------------
1652 7.5.3. Advanced Forwarding Examples
1654 If you have links to multiple ISPs that provide various special content only to
1655 their subscribers, you can configure multiple Privoxies which have connections
1656 to the respective ISPs to act as forwarders to each other, so that your users
1657 can see the internal content of all ISPs.
1659 Assume that host-a has a PPP connection to isp-a.net. And host-b has a PPP
1660 connection to isp-b.net. Both run Privoxy. Their forwarding configuration can
1666 forward .isp-b.net host-b:8118
1671 forward .isp-a.net host-a:8118
1673 Now, your users can set their browser's proxy to use either host-a or host-b
1674 and be able to browse the internal content of both isp-a and isp-b.
1676 If you intend to chain Privoxy and squid locally, then chain as browser ->
1677 squid -> privoxy is the recommended way.
1679 Assuming that Privoxy and squid run on the same box, your squid configuration
1680 could then look like this:
1682 # Define Privoxy as parent proxy (without ICP)
1683 cache_peer 127.0.0.1 parent 8118 7 no-query
1685 # Define ACL for protocol FTP
1688 # Do not forward FTP requests to Privoxy
1689 always_direct allow ftp
1691 # Forward all the rest to Privoxy
1692 never_direct allow all
1694 You would then need to change your browser's proxy settings to squid's address
1695 and port. Squid normally uses port 3128. If unsure consult http_port in
1698 You could just as well decide to only forward requests for Windows executables
1699 through a virus-scanning parent proxy, say, on antivir.example.com, port 8010:
1702 forward /.*\.(exe|com|dll|zip)$ antivir.example.com:8010
1703 -------------------------------------------------------------------------------
1705 7.6. Windows GUI Options
1707 Privoxy has a number of options specific to the Windows GUI interface:
1710 If "activity-animation" is set to 1, the Privoxy icon will animate when
1711 "Privoxy" is active. To turn off, set to 0.
1713 activity-animation 1
1717 If "log-messages" is set to 1, Privoxy will log messages to the console window:
1723 If "log-buffer-size" is set to 1, the size of the log buffer, i.e. the amount
1724 of memory used for the log messages displayed in the console window, will be
1725 limited to "log-max-lines" (see below).
1727 Warning: Setting this to 0 will result in the buffer to grow infinitely and eat
1734 log-max-lines is the maximum number of lines held in the log buffer. See above.
1740 If "log-highlight-messages" is set to 1, Privoxy will highlight portions of the
1741 log messages with a bold-faced font:
1743 log-highlight-messages 1
1747 The font used in the console window:
1749 log-font-name Comic Sans MS
1753 Font size used in the console window:
1759 "show-on-task-bar" controls whether or not Privoxy will appear as a button on
1760 the Task bar when minimized:
1766 If "close-button-minimizes" is set to 1, the Windows close button will minimize
1767 Privoxy instead of closing the program (close with the exit option on the File
1770 close-button-minimizes 1
1774 The "hide-console" option is specific to the MS-Win console version of Privoxy.
1775 If this option is used, Privoxy will disconnect from and hide the command
1780 -------------------------------------------------------------------------------
1784 The actions files are used to define what actions Privoxy takes for which URLs,
1785 and thus determine how ad images, cookies and various other aspects of HTTP
1786 content and transactions are handled, and on which sites (or even parts
1787 thereof). There are three such files included with Privoxy (as of version
1788 2.9.15), with differing purposes:
1790 * default.action - is the primary action file that sets the initial values
1791 for all actions. It is intended to provide a base level of functionality
1792 for Privoxy's array of features. So it is a set of broad rules that should
1793 work reasonably well for users everywhere. This is the file that the
1794 developers are keeping updated, and making available to users.
1796 * user.action - is intended to be for local site preferences and exceptions.
1797 As an example, if your ISP or your bank has specific requirements, and need
1798 special handling, this kind of thing should go here. This file will not be
1801 * standard.action - is used by the web based editor, to set various
1802 pre-defined sets of rules for the default actions section in
1803 default.action. These have increasing levels of aggressiveness and have no
1804 influence on your browsing unless you select them explicitly in the editor.
1805 It is not recommend to edit this file.
1808 The list of actions files to be used are defined in the main configuration
1809 file, and are processed in the order they are defined. The content of these can
1810 all be viewed and edited from http://config.privoxy.org/show-status.
1812 An actions file typically has multiple sections. If you want to use "aliases"
1813 in an actions file, you have to place the (optional) alias section at the top
1814 of that file. Then comes the default set of rules which will apply universally
1815 to all sites and pages (be very careful with using such a universal set in
1816 user.action or any other actions file after default.action, because it will
1817 override the result from consulting any previous file). And then below that,
1818 exceptions to the defined universal policies. You can regard user.action as an
1819 appendix to default.action, with the advantage that is a separate file, which
1820 makes preserving your personal settings across Privoxy upgrades easier.
1822 Actions can be used to block anything you want, including ads, banners, or just
1823 some obnoxious URL that you would rather not see. Cookies can be accepted or
1824 rejected, or accepted only during the current browser session (i.e. not written
1825 to disk), content can be modified, JavaScripts tamed, user-tracking fooled, and
1826 much more. See below for a complete list of actions.
1827 -------------------------------------------------------------------------------
1829 8.1. Finding the Right Mix
1831 Note that some actions, like cookie suppression or script disabling, may render
1832 some sites unusable that rely on these techniques to work properly. Finding the
1833 right mix of actions is not always easy and certainly a matter of personal
1834 taste. In general, it can be said that the more "aggressive" your default
1835 settings (in the top section of the actions file) are, the more exceptions for
1836 "trusted" sites you will have to make later. If, for example, you want to kill
1837 popup windows per default, you'll have to make exceptions from that rule for
1838 sites that you regularly use and that require popups for actually useful
1839 content, like maybe your bank, favorite shop, or newspaper.
1841 We have tried to provide you with reasonable rules to start from in the
1842 distribution actions files. But there is no general rule of thumb on these
1843 things. There just are too many variables, and sites are constantly changing.
1844 Sooner or later you will want to change the rules (and read this chapter again
1846 -------------------------------------------------------------------------------
1850 The easiest way to edit the actions files is with a browser by using our
1851 browser-based editor, which can be reached from http://config.privoxy.org/
1852 show-status. The editor allows both fine-grained control over every single
1853 feature on a per-URL basis, and easy choosing from wholesale sets of defaults
1854 like "Cautious", "Medium" or "Advanced".
1856 If you prefer plain text editing to GUIs, you can of course also directly edit
1857 the the actions files. Look at default.action which is richly commented.
1858 -------------------------------------------------------------------------------
1860 8.3. How Actions are Applied to URLs
1862 Actions files are divided into sections. There are special sections, like the "
1863 alias" sections which will be discussed later. For now let's concentrate on
1864 regular sections: They have a heading line (often split up to multiple lines
1865 for readability) which consist of a list of actions, separated by whitespace
1866 and enclosed in curly braces. Below that, there is a list of URL patterns, each
1869 To determine which actions apply to a request, the URL of the request is
1870 compared to all patterns in each action file file. Every time it matches, the
1871 list of applicable actions for the URL is incrementally updated, using the
1872 heading of the section in which the pattern is located. If multiple matches for
1873 the same URL set the same action differently, the last match wins. If not, the
1874 effects are aggregated. E.g. a URL might match a regular section with a heading
1875 line of { +handle-as-image }, then later another one with just { +block },
1876 resulting in both actions to apply.
1878 You can trace this process for any given URL by visiting http://
1879 config.privoxy.org/show-url-info.
1881 More detail on this is provided in the Appendix, Anatomy of an Action.
1882 -------------------------------------------------------------------------------
1886 Generally, a pattern has the form <domain>/<path>, where both the <domain> and
1887 <path> are optional. (This is why the pattern / matches all URLs).
1890 is a domain-only pattern and will match any request to www.example.com,
1891 regardless of which document on that server is requested.
1894 means exactly the same. For domain-only patterns, the trailing / may be
1897 www.example.com/index.html
1898 matches only the single document /index.html on www.example.com.
1901 matches the document /index.html, regardless of the domain, i.e. on any web
1905 matches nothing, since it would be interpreted as a domain name and there
1906 is no top-level domain called .html.
1909 -------------------------------------------------------------------------------
1910 8.4.1. The Domain Pattern
1912 The matching of the domain part offers some flexible options: if the domain
1913 starts or ends with a dot, it becomes unanchored at that end. For example:
1916 matches any domain that ENDS in .example.com
1919 matches any domain that STARTS with www.
1922 matches any domain that CONTAINS .example. (Correctly speaking: It matches
1923 any FQDN that contains example as a domain.)
1926 Additionally, there are wild-cards that you can use in the domain names
1927 themselves. They work pretty similar to shell wild-cards: "*" stands for zero
1928 or more arbitrary characters, "?" stands for any single character, you can
1929 define character classes in square brackets and all of that can be freely
1933 matches "adserver.example.com", "ads.example.com", etc but not
1937 matches all of the above, and then some.
1940 matches www.ipix.com, pictures.epix.com, a.b.c.d.e.upix.com etc.
1942 www[1-9a-ez].example.c*
1943 matches www1.example.com, www4.example.cc, wwwd.example.cy,
1944 wwwz.example.com etc., but not wwww.example.com.
1947 -------------------------------------------------------------------------------
1948 8.4.2. The Path Pattern
1950 Privoxy uses Perl compatible regular expressions (through the PCRE library) for
1953 There is an Appendix with a brief quick-start into regular expressions, and
1954 full (very technical) documentation on PCRE regex syntax is available on-line
1955 at http://www.pcre.org/man.txt. You might also find the Perl man page on
1956 regular expressions (man perlre) useful, which is available on-line at http://
1957 www.perldoc.com/perl5.6/pod/perlre.html.
1959 Note that the path pattern is automatically left-anchored at the "/", i.e. it
1960 matches as if it would start with a "^" (regular expression speak for the
1961 beginning of a line).
1963 Please also note that matching in the path is CASE INSENSITIVE by default, but
1964 you can switch to case sensitive at any point in the pattern by using the "(?
1965 -i)" switch: www.example.com/(?-i)PaTtErN.* will match only documents whose
1966 path starts with PaTtErN in exactly this capitalization.
1967 -------------------------------------------------------------------------------
1971 All actions are disabled by default, until they are explicitly enabled
1972 somewhere in an actions file. Actions are turned on if preceded with a "+", and
1973 turned off if preceded with a "-". So a +action means "do that action", e.g.
1974 +block means "please block URLs that match the following patterns", and -block
1975 means "don't block URLs that match the following patterns, even if +block
1976 previously applied."
1978 Again, actions are invoked by placing them on a line, enclosed in curly braces
1979 and separated by whitespace, like in {+some-action -some-other-action
1980 {some-parameter}}, followed by a list of URL patterns, one per line, to which
1981 they apply. Together, the actions line and the following pattern lines make up
1982 a section of the actions file.
1984 There are three classes of actions:
1986 * Boolean, i.e the action can only be "enabled" or "disabled". Syntax:
1988 +name # enable action name
1989 -name # disable action name
1993 * Parameterized, where some value is required in order to enable this type of
1996 +name{param} # enable action and set parameter to param,
1997 # overwriting parameter from previous match if necessary
1998 -name # disable action. The parameter can be omitted
2000 Note that if the URL matches multiple positive forms of a parameterized
2001 action, the last match wins, i.e. the params from earlier matches are
2004 Example: +hide-user-agent{ Mozilla 1.0 }
2006 * Multi-value. These look exactly like parameterized actions, but they behave
2007 differently: If the action applies multiple times to the same URL, but with
2008 different parameters, all the parameters from all matches are remembered.
2009 This is used for actions that can be executed for the same request
2010 repeatedly, like adding multiple headers, or filtering through multiple
2013 +name{param} # enable action and add param to the list of parameters
2014 -name{param} # remove the parameter param from the list of parameters
2015 # If it was the last one left, disable the action.
2016 -name # disable this action completely and remove all parameters from the list
2018 Examples: +add-header{X-Fun-Header: Some text} and +filter{html-annoyances}
2021 If nothing is specified in any actions file, no "actions" are taken. So in this
2022 case Privoxy would just be a normal, non-blocking, non-anonymizing proxy. You
2023 must specifically enable the privacy and blocking features you need (although
2024 the provided default actions files will give a good starting point).
2026 Later defined actions always over-ride earlier ones. So exceptions to any rules
2027 you make, should come in the latter part of the file (or in a file that is
2028 processed later when using multiple actions files). For multi-valued actions,
2029 the actions are applied in the order they are specified. Actions files are
2030 processed in the order they are defined in config (the default installation has
2031 three actions files). It also quite possible for any given URL pattern to match
2032 more than one pattern and thus more than one set of actions!
2034 The list of valid Privoxy actions are:
2035 -------------------------------------------------------------------------------
2040 Confuse log analysis, custom applications
2043 Sends a user defined HTTP header to the web server.
2049 Any string value is possible. Validity of the defined HTTP headers is not
2050 checked. It is recommended that you use the "X-" prefix for custom headers.
2053 This action may be specified multiple times, in order to define multiple
2054 headers. This is rarely needed for the typical user. If you don't know what
2055 "HTTP headers" are, you definitely don't need to worry about this one.
2058 +add-header{X-User-Tracking: sucks}
2061 -------------------------------------------------------------------------------
2065 Block ads or other obnoxious content
2068 Requests for URLs to which this action applies are blocked, i.e. the
2069 requests are not forwarded to the remote server, but answered locally with
2070 a substitute page or image, as determined by the handle-as-image and
2071 set-image-blocker actions.
2080 Privoxy sends a special "BLOCKED" page for requests to blocked pages. This
2081 page contains links to find out why the request was blocked, and a
2082 click-through to the blocked content (the latter only if compiled with the
2083 force feature enabled). The "BLOCKED" page adapts to the available screen
2084 space -- it displays full-blown if space allows, or miniaturized and
2085 text-only if loaded into a small frame or window. If you are using Privoxy
2086 right now, you can take a look at the "BLOCKED" page.
2088 A very important exception occurs if both block and handle-as-image, apply
2089 to the same request: it will then be replaced by an image. If
2090 set-image-blocker (see below) also applies, the type of image will be
2091 determined by its parameter, if not, the standard checkerboard pattern is
2094 It is important to understand this process, in order to understand how
2095 Privoxy deals with ads and other unwanted content.
2097 The filter action can perform a very similar task, by "blocking" banner
2098 images and other content through rewriting the relevant URLs in the
2099 document's HTML source, so they don't get requested in the first place.
2100 Note that this is a totally different technique, and it's easy to confuse
2103 Example usage (section):
2104 {+block} # Block and replace with "blocked" page
2105 .nasty-stuff.example.com
2107 {+block +handle-as-image} # Block and replace with image
2112 -------------------------------------------------------------------------------
2113 8.5.3. crunch-incoming-cookies
2116 Prevent the web server from setting any cookies on your system
2119 Deletes any "Set-Cookie:" HTTP headers from server replies.
2128 This action is only concerned with incoming cookies. For outgoing cookies,
2129 use crunch-outgoing-cookies. Use both to disable cookies completely.
2131 It makes no sense at all to use this action in conjunction with the
2132 session-cookies-only action, since it would prevent the session cookies
2136 +crunch-incoming-cookies
2139 -------------------------------------------------------------------------------
2140 8.5.4. crunch-outgoing-cookies
2143 Prevent the web server from reading any cookies from your system
2146 Deletes any "Cookie:" HTTP headers from client requests.
2155 This action is only concerned with outgoing cookies. For incoming cookies,
2156 use crunch-incoming-cookies. Use both to disable cookies completely.
2158 It makes no sense at all to use this action in conjunction with the
2159 session-cookies-only action, since it would prevent the session cookies
2163 +crunch-outgoing-cookies
2166 -------------------------------------------------------------------------------
2167 8.5.5. deanimate-gifs
2170 Stop those annoying, distracting animated GIF images.
2173 De-animate GIF animations, i.e. reduce them to their first or last image.
2182 This will also shrink the images considerably (in bytes, not pixels!). If
2183 the option "first" is given, the first frame of the animation is used as
2184 the replacement. If "last" is given, the last frame of the animation is
2185 used instead, which probably makes more sense for most banner animations,
2186 but also has the risk of not showing the entire last frame (if it is only a
2187 delta to an earlier frame).
2189 You can safely use this action with patterns that will also match non-GIF
2190 objects, because no attempt will be made at anything that doesn't look like
2194 +deanimate-gifs{last}
2197 -------------------------------------------------------------------------------
2198 8.5.6. downgrade-http-version
2201 Work around (very rare) problems with HTTP/1.1
2204 Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0.
2213 This is a left-over from the time when Privoxy didn't support important
2214 HTTP/1.1 features well. It is left here for the unlikely case that you
2215 experience HTTP/1.1 related problems with some server out there. Not all
2216 (optional) HTTP/1.1 features are supported yet, so there is a chance you
2217 might need this action.
2219 Example usage (section):
2220 {+downgrade-http-version}
2221 problem-host.example.com
2224 -------------------------------------------------------------------------------
2225 8.5.7. fast-redirects
2228 Fool some click-tracking scripts and speed up indirect links
2231 Cut off all but the last valid URL from requests.
2240 Many sites, like yahoo.com, don't just link to other sites. Instead, they
2241 will link to some script on their own servers, giving the destination as a
2242 parameter, which will then redirect you to the final target. URLs resulting
2243 from this scheme typically look like: http://some.place/click-tracker.cgi?
2244 target=http://some.where.else.
2246 Sometimes, there are even multiple consecutive redirects encoded in the
2247 URL. These redirections via scripts make your web browsing more traceable,
2248 since the server from which you follow such a link can see where you go to.
2249 Apart from that, valuable bandwidth and time is wasted, while your browser
2250 ask the server for one redirect after the other. Plus, it feeds the
2253 This feature is currently not very smart and is scheduled for improvement.
2254 It is likely to break some sites. You should expect to need possibly many
2255 exceptions to this action, if it is enabled by default in default.action.
2256 Some sites just don't work without it.
2262 -------------------------------------------------------------------------------
2266 Get rid of HTML and JavaScript annoyances, banner advertisements (by size),
2267 do fun text replacements, etc.
2270 Text documents, including HTML and JavaScript, to which this action
2271 applies, are filtered on-the-fly through the specified regular expression
2272 based substitutions.
2278 The name of a filter, as defined in the filter file (typically
2279 default.filter, set by the filterfile option in the config file). Filtering
2280 can be completely disabled without the use of parameters.
2283 For your convenience, there are a number of pre-defined filters available
2284 in the distribution filter file that you can use. See the examples below
2287 This is potentially a very powerful feature! But "rolling your own" filters
2288 requires a knowledge of regular expressions and HTML.
2290 Filtering requires buffering the page content, which may appear to slow
2291 down page rendering since nothing is displayed until all content has passed
2292 the filters. (It does not really take longer, but seems that way since the
2293 page is not incrementally displayed.) This effect will be more noticeable
2294 on slower connections.
2296 The amount of data that can be filtered is limited to the buffer-limit
2297 option in the main config file. The default is 4096 KB (4 Megs). Once this
2298 limit is exceeded, the buffered data, and all pending data, is passed
2299 through unfiltered. Inappropriate MIME types are not filtered.
2301 At this time, Privoxy cannot (yet!) uncompress compressed documents. If you
2302 want filtering to work on all documents, even those that would normally be
2303 sent compressed, use the prevent-compression action in conjunction with
2306 Filtering can achieve some of the same effects as the block action, i.e. it
2307 can be used to block ads and banners. But the mechanism works quite
2308 differently. One effective use, is to block ad banners based on their size
2309 (see below), since many of these seem to be somewhat standardized.
2311 Feedback with suggestions for new or improved filters is particularly
2314 Example usage (with filters from the distribution default.filter file):
2315 +filter{html-annoyances} # Get rid of particularly annoying HTML abuse.
2317 +filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse
2319 +filter{banners-by-size} # Kill banners based on their size for this page (very efficient!)
2321 +filter{banners-by-link} # Kill banners based on the link they are contained in (experimental)
2323 +filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective
2325 +filter{content-cookies} # Kill cookies that come sneaking in the HTML or JS content
2327 +filter{popups} # Kill all popups in JS and HTML
2329 +filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking)
2331 +filter{fun} # Text replacements for subversive browsing fun!
2333 +filter{frameset-borders} # Give frames a border and make them resizeable
2335 +filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups)
2337 +filter{nimda} # Remove Nimda (virus) code.
2339 +filter{shockwave-flash} # Kill embedded Shockwave Flash objects
2341 +filter{crude-parental} # Kill all web pages that contain the words "sex" or "warez"
2343 +filter{js-events} # Kill all JS event bindings (Radically destructive! Only for extra nasty sites)
2346 -------------------------------------------------------------------------------
2347 8.5.9. handle-as-image
2350 Mark URLs as belonging to images (so they'll be replaced by images if they
2354 This action alone doesn't do anything noticeable. It just marks URLs as
2355 images. If the block action also applies, the presence or absence of this
2356 mark decides whether an HTML "blocked" page, or a replacement image (as
2357 determined by the set-image-blocker action) will be sent to the client as a
2358 substitute for the blocked content.
2367 The below generic example section is actually part of default.action. It
2368 marks all URLs with well-known image file name extensions as images and
2369 should be left intact.
2371 Users will probably only want to use the handle-as-image action in
2372 conjunction with block, to block sources of banners, whose URLs don't
2373 reflect the file type, like in the second example section.
2375 Note that you cannot treat HTML pages as images in most cases. For
2376 instance, (in-line) ad frames require an HTML page to be sent, or they
2377 won't display properly. Forcing handle-as-image in this situation will not
2378 replace the ad frame with an image, but lead to error messages.
2380 Example usage (sections):
2381 # Generic image extensions:
2384 /.*\.(gif|jpg|jpeg|png|bmp|ico)$
2386 # These don't look like images, but they're banners and should be
2387 # blocked as images:
2389 {+block +handle-as-image}
2390 some.nasty-banner-server.com/junk.cgi?output=trash
2392 # Banner source! Who cares if they also have non-image content?
2396 -------------------------------------------------------------------------------
2397 8.5.10. hide-forwarded-for-headers
2400 Improve privacy by hiding the true source of the request
2403 Deletes any existing "X-Forwarded-for:" HTTP header from client requests,
2404 and prevents adding a new one.
2413 It is fairly safe to leave this on.
2415 This action is scheduled for improvement: It should be able to generate
2416 forged "X-Forwarded-for:" headers using random IP addresses from a
2417 specified network, to make successive requests from the same client look
2418 like requests from a pool of different users sharing the same proxy.
2421 +hide-forwarded-for-headers
2424 -------------------------------------------------------------------------------
2425 8.5.11. hide-from-header
2428 Keep your (old and ill) browser from telling web servers your email address
2431 Deletes any existing "From:" HTTP header, or replaces it with the specified
2438 Keyword: "block", or any user defined value.
2441 The keyword "block" will completely remove the header (not to be confused
2442 with the block action).
2444 Alternately, you can specify any value you prefer to be sent to the web
2445 server. If you do, it is a matter of fairness not to use any address that
2446 is actually used by a real person.
2448 This action is rarely needed, as modern web browsers don't send "From:"
2452 +hide-from-header{block}
2454 +hide-from-header{spam-me-senseless@sittingduck.example.com}
2457 -------------------------------------------------------------------------------
2458 8.5.12. hide-referrer
2461 Conceal which link you followed to get to a particular site
2464 Deletes the "Referer:" (sic) HTTP header from the client request, or
2465 replaces it with a forged one.
2471 + "block" to delete the header completely.
2473 + "forge" to pretend to be coming from the homepage of the server we are
2476 + Any other string to set a user defined referrer.
2480 "forge" is the preferred option here, since some servers will not send
2481 images back otherwise, in an attempt to prevent their valuable content from
2482 being embedded elsewhere (and hence, without being surrounded by their
2485 hide-referer is an alternate spelling of hide-referrer and the two can be
2486 can be freely substituted with each other. ("referrer" is the correct
2487 English spelling, however the HTTP specification has a bug - it requires it
2488 to be spelled as "referer".)
2491 +hide-referrer{forge}
2493 +hide-referrer{http://www.yahoo.com/}
2496 -------------------------------------------------------------------------------
2497 8.5.13. hide-user-agent
2500 Conceal your type of browser and client operating system
2503 Replaces the value of the "User-Agent:" HTTP header in client requests with
2504 the specified value.
2510 Any user-defined string.
2513 +-----------------------------------------------------------------+
2515 +-----------------------------------------------------------------+
2516 |This breaks many web sites that depend on looking at this header |
2517 |in order to customize their content for different browsers |
2518 |(which, by the way, is NOT a smart way to do that!). |
2519 +-----------------------------------------------------------------+
2521 Using this action in multi-user setups or wherever different types of
2522 browsers will access the same Privoxy is not recommended. In single-user,
2523 single-browser setups, you might use it to delete your OS version
2524 information from the headers, because it is an invitation to exploit known
2525 bugs for your OS. It is also occasionally useful to forge this in order to
2526 access sites that won't let you in otherwise (though there may be a good
2527 reason in some cases). Example of this: some MSN sites will not let Mozilla
2528 enter, yet forging to a Netscape 6.1 user-agent works just fine. (Must be
2529 just a silly MS goof, I'm sure :-).
2531 This action is scheduled for improvement.
2534 +hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}
2537 -------------------------------------------------------------------------------
2541 Eliminate those annoying pop-up windows
2544 While loading the document, replace JavaScript code that opens pop-up
2545 windows with (syntactically neutral) dummy code on the fly.
2554 This action is easily confused with the built-in, hardwired filter action,
2555 but there are important differences: For kill-popups, the document need not
2556 be buffered, so it can be incrementally rendered while downloading. But
2557 kill-popups doesn't catch as many pop-ups as filter{popups} does.
2559 Think of it as a fast and efficient replacement for a filter that you can
2560 use if you don't want any filtering at all. Note that it doesn't make sense
2561 to combine it with any filter action, since as soon as one filter applies,
2562 the whole document needs to be buffered anyway, which destroys the
2563 advantage of the kill-popups action over its filter equivalent.
2565 Killing all pop-ups is a dangerous business. Many shops and banks rely on
2566 pop-ups to display forms, shopping carts etc, and killing only the unwanted
2567 pop-ups would require artificial intelligence in Privoxy. If the only kind
2568 of pop-ups that you want to kill are exit consoles (those really nasty
2569 windows that appear when you close an other one), you might want to use
2570 filter{js-annoyances} instead.
2576 -------------------------------------------------------------------------------
2577 8.5.15. limit-connect
2580 Prevent abuse of Privoxy as a TCP proxy relay
2583 Specifies to which ports HTTP CONNECT requests are allowable.
2589 A comma-separated list of ports or port ranges (the latter using dashes,
2590 with the minimum defaulting to 0 and the maximum to 65K).
2593 By default, i.e. if no limit-connect action applies, Privoxy only allows
2594 HTTP CONNECT requests to port 443 (the standard, secure HTTPS port). Use
2595 limit-connect if more fine-grained control is desired for some or all
2598 The CONNECT methods exists in HTTP to allow access to secure websites (
2599 "https://" URLs) through proxies. It works very simply: the proxy connects
2600 to the server on the specified port, and then short-circuits its
2601 connections to the client and to the remote server. This can be a big
2602 security hole, since CONNECT-enabled proxies can be abused as TCP relays
2605 If you don't know what any of this means, there probably is no reason to
2606 change this one, since the default is already very restrictive.
2609 +limit-connect{443} # This is the default and need not be specified.
2610 +limit-connect{80,443} # Ports 80 and 443 are OK.
2611 +limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
2612 +limit-connect{-} # All ports are OK (gaping security hole!)
2615 -------------------------------------------------------------------------------
2616 8.5.16. prevent-compression
2619 Ensure that servers send the content uncompressed, so it can be passed
2623 Adds a header to the request that asks for uncompressed transfer.
2632 More and more websites send their content compressed by default, which is
2633 generally a good idea and saves bandwidth. But for the filter,
2634 deanimate-gifs and kill-popups actions to work, Privoxy needs access to the
2635 uncompressed data. Unfortunately, Privoxy can't yet(!) uncompress, filter,
2636 and re-compress the content on the fly. So if you want to ensure that all
2637 websites, including those that normally compress, can be filtered, you need
2640 This will slow down transfers from those websites, though. If you use any
2641 of the above-mentioned actions, you will typically want to use
2642 prevent-compression in conjunction with them.
2644 Note that some (rare) ill-configured sites don't handle requests for
2645 uncompressed documents correctly (they send an empty document body). If you
2646 use prevent-compression per default, you'll have to add exceptions for
2647 those sites. See the example for how to do that.
2649 Example usage (sections):
2652 {+prevent-compression}
2655 # Make exceptions for ill sites:
2657 {-prevent-compression}
2659 www.pclinuxonline.com
2662 -------------------------------------------------------------------------------
2663 8.5.17. send-vanilla-wafer
2666 Feed log analysis scripts with useless data.
2669 Sends a cookie with each request stating that you do not accept any
2670 copyright on cookies sent to you, and asking the site operator not to track
2680 The vanilla wafer is a (relatively) unique header and could conceivably be
2683 This action is rarely used and not enabled in the default configuration.
2689 -------------------------------------------------------------------------------
2693 Send custom cookies or feed log analysis scripts with even more useless
2697 Sends a custom, user-defined cookie with each request.
2703 A string of the form "name=value".
2706 Being multi-valued, multiple instances of this action can apply to the same
2707 request, resulting in multiple cookies being sent.
2709 This action is rarely used and not enabled in the default configuration.
2711 Example usage (section):
2712 {+send-wafer{UsingPrivoxy=true}}
2713 my-internal-testing-server.void
2716 -------------------------------------------------------------------------------
2717 8.5.19. session-cookies-only
2720 Allow only temporary "session" cookies (for the current browser session
2724 Deletes the "expires" field from "Set-Cookie:" server headers. Most
2725 browsers will not store such cookies permanently and forget them in between
2735 This is less strict than crunch-incoming-cookies / crunch-outgoing-cookies
2736 and allows you to browse websites that insist or rely on setting cookies,
2737 without compromising your privacy too badly.
2739 Most browsers will not permanently store cookies that have been processed
2740 by session-cookies-only and will forget about them between sessions. This
2741 makes profiling cookies useless, but won't break sites which require
2742 cookies so that you can log in for transactions. This is generally turned
2743 on for all sites, and is the recommended setting.
2745 It makes no sense at all to use session-cookies-only together with
2746 crunch-incoming-cookies or crunch-outgoing-cookies. If you do, cookies will
2749 Note that it is up to the browser how it handles such cookies without an
2750 "expires" field. If you use an exotic browser, you might want to try it out
2754 +session-cookies-only
2757 -------------------------------------------------------------------------------
2758 8.5.20. set-image-blocker
2761 Choose the replacement for blocked images
2764 This action alone doesn't do anything noticeable. If both block and
2765 handle-as-image also apply, i.e. if the request is to be blocked as an
2766 image, then the parameter of this action decides what will be sent as a
2773 + "pattern" to send a built-in checkerboard pattern image. The image is
2774 visually decent, scales very well, and makes it obvious where banners
2777 + "blank" to send a built-in transparent image. This makes banners
2778 disappear completely, but makes it hard to detect where Privoxy has
2779 blocked images on a given page and complicates troubleshooting if
2780 Privoxy has blocked innocent images, like navigation icons.
2782 + "target-url" to send a redirect to target-url. You can redirect to any
2783 image anywhere, even in your local filesystem (via "file:///" URL).
2785 A good application of redirects is to use special Privoxy-built-in
2786 URLs, which send the built-in images, as target-url. This has the same
2787 visual effect as specifying "blank" or "pattern" in the first place,
2788 but enables your browser to cache the replacement image, instead of
2789 requesting it over and over again.
2793 The URLs for the built-in images are "http://config.privoxy.org/
2794 send-banner?type=type", where type is either "blank" or "pattern".
2796 There is a third (advanced) type, called "auto". It is NOT to be used in
2797 set-image-blocker, but meant for use from filters. Auto will select the
2798 type of image that would have applied to the referring page, had it been an
2804 +set-image-blocker{pattern}
2806 Redirect to the BSD devil:
2808 +set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}
2810 Redirect to the built-in pattern for better caching:
2812 +set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}
2815 -------------------------------------------------------------------------------
2818 Note that many of these actions have the potential to cause a page to
2819 misbehave, possibly even not to display at all. There are many ways a site
2820 designer may choose to design his site, and what HTTP header content, and other
2821 criteria, he may depend on. There is no way to have hard and fast rules for all
2822 sites. See the Appendix for a brief example on troubleshooting actions.
2823 -------------------------------------------------------------------------------
2827 Custom "actions", known to Privoxy as "aliases", can be defined by combining
2828 other actions. These can in turn be invoked just like the built-in actions.
2829 Currently, an alias name can contain any character except space, tab, "=", "{"
2830 and "}", but we strongly recommend that you only use "a" to "z", "0" to "9",
2831 "+", and "-". Alias names are not case sensitive, and are not required to start
2832 with a "+" or "-" sign, since they are merely textually expanded.
2834 Aliases can be used throughout the actions file, but they must be defined in a
2835 special section at the top of the file! And there can only be one such section
2836 per actions file. Each actions file may have its own alias section, and the
2837 aliases defined in it are only visible within that file.
2839 There are two main reasons to use aliases: One is to save typing for frequently
2840 used combinations of actions, the other one is a gain in flexibility: If you
2841 decide once how you want to handle shops by defining an alias called "shop",
2842 you can later change your policy on shops in one place, and your changes will
2843 take effect everywhere in the actions file where the "shop" alias is used.
2844 Calling aliases by their purpose also makes your actions files more readable.
2846 Currently, there is one big drawback to using aliases, though: Privoxy's
2847 built-in web-based action file editor honors aliases when reading the actions
2848 files, but it expands them before writing. So the effects of your aliases are
2849 of course preserved, but the aliases themselves are lost when you edit sections
2850 that use aliases with it. This is likely to change in future versions of
2853 Now let's define some aliases...
2855 # Useful custom aliases we can use later.
2857 # Note the (required!) section header line and that this section
2858 # must be at the top of the actions file!
2862 # These aliases just save typing later:
2863 # (Note that some already use other aliases!)
2865 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
2866 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
2867 block-as-image = +block +handle-as-image
2868 mercy-for-cookies = -crunch-all-cookies -session-cookies-only
2870 # These aliases define combinations of actions
2871 # that are useful for certain types of sites:
2873 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
2874 shop = -crunch-all-cookies -filter{popups} -kill-popups
2876 # Short names for other aliases, for really lazy people ;-)
2878 c0 = +crunch-all-cookies
2879 c1 = -crunch-all-cookies
2881 ...and put them to use. These sections would appear in the lower part of an
2882 actions file and define exceptions to the default actions (as specified further
2883 up for the "/" pattern):
2885 # These sites are either very complex or very keen on
2886 # user data and require minimal interference to work:
2889 .office.microsoft.com
2890 .windowsupdate.microsoft.com
2894 # Allow cookies (for setting and retrieving your customer data)
2898 .worldpay.com # for quietpc.com
2901 # These shops require pop-ups:
2903 {shop -kill-popups -filter{popups}}
2907 Aliases like "shop" and "fragile" are often used for "problem" sites that
2908 require some actions to be disabled in order to function properly.
2909 -------------------------------------------------------------------------------
2911 8.7. Actions Files Tutorial
2913 The above chapters have shown which actions files there are and how they are
2914 organized, how actions are specified and applied to URLs, how patterns work,
2915 and how to define and use aliases. Now, let's look at an example default.action
2916 and user.action file and see how all these pieces come together:
2917 -------------------------------------------------------------------------------
2919 8.7.1. default.action
2921 Every config file should start with a short comment stating its purpose:
2923 # Sample default.action file <developers@privoxy.org>
2925 Then, since this is the default.action file, the first section is a special
2926 section for internal use that you needn't change or worry about:
2928 ##########################################################################
2929 # Settings -- Don't change! For internal Privoxy use ONLY.
2930 ##########################################################################
2933 for-privoxy-version=3.0
2935 After that comes the (optional) alias section. We'll use the example section
2936 from the above chapter on aliases, that also explains why and how aliases are
2939 ##########################################################################
2941 ##########################################################################
2944 # These aliases just save typing later:
2945 # (Note that some already use other aliases!)
2947 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
2948 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
2949 block-as-image = +block +handle-as-image
2950 mercy-for-cookies = -crunch-all-cookies -session-cookies-only
2952 # These aliases define combinations of actions
2953 # that are useful for certain types of sites:
2955 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
2956 shop = mercy-for-cookies -filter{popups} -kill-popups
2958 Now come the regular sections, i.e. sets of actions, accompanied by URL
2959 patterns to which they apply. Remember all actions are disabled when matching
2960 starts, so we have to explicitly enable the ones we want.
2962 The first regular section is probably the most important. It has only one
2963 pattern, "/", but this pattern matches all URLs. Therefore, the set of actions
2964 used in this "default" section will be applied to all requests as a start. It
2965 can be partly or wholly overridden by later matches further down this file, or
2966 in user.action, but it will still be largely responsible for your overall
2967 browsing experience.
2969 Again, at the start of matching, all actions are disabled, so there is no real
2970 need to disable any actions here, but we will do that nonetheless, to have a
2971 complete listing for your reference. (Remember: a "+" preceding the action name
2972 enables the action, a "-" disables!). Also note how this long line has been
2973 made more readable by splitting it into multiple lines with line continuation.
2975 ##########################################################################
2976 # "Defaults" section:
2977 ##########################################################################
2981 -crunch-incoming-cookies \
2982 -crunch-outgoing-cookies \
2984 -downgrade-http-version \
2986 +filter{html-annoyances} \
2987 +filter{js-annoyances} \
2988 -filter{content-cookies} \
2991 -filter{refresh-tags} \
2994 +filter{banners-by-size} \
2995 -filter{banners-by-link} \
2996 -filter{img-reorder} \
2997 -filter{shockwave-flash} \
2998 -filter{crude-parental} \
2999 -filter{js-events} \
3001 +hide-forwarded-for-headers \
3002 +hide-from-header{block} \
3003 +hide-referrer{forge} \
3007 +prevent-compression \
3008 -send-vanilla-wafer \
3010 +session-cookies-only \
3011 +set-image-blocker{pattern} \
3013 / # forward slash will match *all* potential URL patterns.
3015 The default behavior is now set. Note that some actions, like not hiding the
3016 user agent, are part of a "general policy" that applies universally and won't
3017 get any exceptions defined later. Other choices, like not blocking (which is
3018 understandably the default!) need exceptions, i.e. we need to specify
3019 explicitly what we want to block in later sections. We will also want to make
3020 exceptions from our general pop-up-killing, and use our defined aliases for
3023 The first of our specialized sections is concerned with "fragile" sites, i.e.
3024 sites that require minimum interference, because they are either very complex
3025 or very keen on tracking you (and have mechanisms in place that make them
3026 unusable for people who avoid being tracked). We will simply use our
3027 pre-defined fragile alias instead of stating the list of actions explicitly:
3029 ##########################################################################
3030 # Exceptions for sites that'll break under the default action set:
3031 ##########################################################################
3033 # "Fragile" Use a minimum set of actions for these sites (see alias above):
3036 .office.microsoft.com # surprise, surprise!
3037 .windowsupdate.microsoft.com
3039 Shopping sites are not as fragile, but they typically require cookies to log
3040 in, and pop-up windows for shopping carts or item details. Again, we'll use a
3047 .worldpay.com # for quietpc.com
3051 Then, there are sites which rely on pop-up windows (yuck!) to work. Since we
3052 made pop-up-killing our default above, we need to make exceptions now. Mozilla
3053 users, who can turn on smart handling of unwanted pop-ups in their browsers,
3054 can safely choose -filter{popups} (and -kill-popups) above and hence don't need
3055 this section. Anyway, disabling an already disabled action doesn't hurt, so
3056 we'll define our exceptions regardless of what was chosen in the defaults
3059 # These sites require pop-ups too :(
3061 { -kill-popups -filter{popups} }
3064 .deutsche-bank-24.de
3066 The fast-redirects action, which we enabled per default above, breaks some
3067 sites. So disable it for popular sites where we know it misbehaves:
3073 .altavista.com/.*(like|url|link):http
3074 .altavista.com/trans.*urltext=http
3077 It is important that Privoxy knows which URLs belong to images, so that if they
3078 are to be blocked, a substitute image can be sent, rather than an HTML page.
3079 Contacting the remote site to find out is not an option, since it would destroy
3080 the loading time advantage of banner blocking, and it would feed the
3081 advertisers (in terms of money and information). We can mark any URL as an
3082 image with the handle-as-image action, and marking all URLs that end in a known
3083 image file extension is a good start:
3085 ##########################################################################
3087 ##########################################################################
3089 # Define which file types will be treated as images, in case they get
3090 # blocked further down this file:
3092 { +handle-as-image }
3093 /.*\.(gif|jpe?g|png|bmp|ico)$
3095 And then there are known banner sources. They often use scripts to generate the
3096 banners, so it won't be visible from the URL that the request is for an image.
3097 Hence we block them and mark them as images in one go, with the help of our
3098 block-as-image alias defined above. (We could of course just as well use +block
3099 +handle-as-image here.) Remember that the type of the replacement image is
3100 chosen by the set-image-blocker action. Since all URLs have matched the default
3101 section with its +set-image-blocker{pattern} action before, it still applies
3102 and needn't be repeated:
3104 # Known ad generators:
3109 .ad.*.doubleclick.net
3110 .a.yimg.com/(?:(?!/i/).)*$
3111 .a[0-9].yimg.com/(?:(?!/i/).)*$
3116 One of the most important jobs of Privoxy is to block banners. A huge bunch of
3117 them are already "blocked" by the filter{banners-by-size} action, which we
3118 enabled above, and which deletes the references to banner images from the pages
3119 while they are loaded, so the browser doesn't request them anymore, and hence
3120 they don't need to be blocked here. But this naturally doesn't catch all
3121 banners, and some people choose not to use filters, so we need a comprehensive
3122 list of patterns for banner URLs here, and apply the block action to them.
3124 First comes a bunch of generic patterns, which do most of the work, by matching
3125 typical domain and path name components of banners. Then comes a list of
3126 individual patterns for specific sites, which is omitted here to keep the
3129 ##########################################################################
3130 # Block these fine banners:
3131 ##########################################################################
3140 /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
3141 /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
3143 # Site-specific patterns (abbreviated):
3147 You wouldn't believe how many advertisers actually call their banner servers
3148 ads.company.com, or call the directory in which the banners are stored simply
3149 "banners". So the above generic patterns are surprisingly effective.
3151 But being very generic, they necessarily also catch URLs that we don't want to
3152 block. The pattern .*ads. e.g. catches "nasty-ads.nasty-corp.com" as intended,
3153 but also "downloads.sourcefroge.net" or "adsl.some-provider.net." So here come
3154 some well-known exceptions to the +block section above.
3156 Note that these are exceptions to exceptions from the default! Consider the URL
3157 "downloads.sourcefroge.net": Initially, all actions are deactivated, so it
3158 wouldn't get blocked. Then comes the defaults section, which matches the URL,
3159 but just deactivates the block action once again. Then it matches .*ads., an
3160 exception to the general non-blocking policy, and suddenly +block applies. And
3161 now, it'll match .*loads., where -block applies, so (unless it matches again
3162 further down) it ends up with no block action applying.
3164 ##########################################################################
3165 # Save some innocent victims of the above generic block patterns:
3166 ##########################################################################
3171 adv[io]*. # (for advogato.org and advice.*)
3172 adsl. # (has nothing to do with ads)
3173 ad[ud]*. # (adult.* and add.*)
3174 .edu # (universities don't host banners (yet!))
3175 .*loads. # (downloads, uploads etc)
3183 www.globalintersec.com/adv # (adv = advanced)
3184 www.ugu.com/sui/ugu/adv
3186 Filtering source code can have nasty side effects, so make an exception for our
3187 friends at sourceforge.net, and all paths with "cvs" in them. Note that -filter
3188 disables all filters in one fell swoop!
3190 # Don't filter code!
3196 The actual default.action is of course more comprehensive, but we hope this
3197 example made clear how it works.
3198 -------------------------------------------------------------------------------
3202 So far we are painting with a broad brush by setting general policies, which
3203 would be a reasonable starting point for many people. Now, you might want to be
3204 more specific and have customized rules that are more suitable to your personal
3205 habits and preferences. These would be for narrowly defined situations like
3206 your ISP or your bank, and should be placed in user.action, which is parsed
3207 after all other actions files and hence has the last word, over-riding any
3208 previously defined actions. user.action is also a safe place for your personal
3209 settings, since default.action is actively maintained by the Privoxy developers
3210 and you'll probably want to install updated versions from time to time.
3212 So let's look at a few examples of things that one might typically do in
3215 # My user.action file. <fred@foobar.com>
3217 As aliases are local to the actions file that they are defined in, you can't
3218 use the ones from default.action, unless you repeat them here:
3220 # (Re-)define aliases for this file:
3223 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
3224 mercy-for-cookies = -crunch-all-cookies -session-cookies-only
3225 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
3226 shop = mercy-for-cookies -filter{popups} -kill-popups
3227 allow-ads = -block -filter{banners-by-size} # (see below)
3229 Say you have accounts on some sites that you visit regularly, and you don't
3230 want to have to log in manually each time. So you'd like to allow persistent
3231 cookies for these sites. The mercy-for-cookies alias defined above does exactly
3232 that, i.e. it disables crunching of cookies in any direction, and processing of
3233 cookies to make them temporary.
3235 { mercy-for-cookies }
3242 Your bank needs popups and is allergic to some filter, but you don't know
3243 which, so you disable them all:
3245 { -filter -kill-popups }
3246 .your-home-banking-site.com
3248 While browsing the web with Privoxy you noticed some ads that sneaked through,
3249 but you were too lazy to report them through our fine and easy feedback system,
3250 so you have added them here:
3253 www.a-popular-site.com/some/unobvious/path
3254 another.popular.site.net/more/junk/here/
3256 Note that, assuming the banners in the above example have regular image
3257 extensions (most do), +handle-as-image need not be specified, since all URLs
3258 ending in these extensions will already have been tagged as images in the
3259 relevant section of default.action by now.
3261 Then you noticed that the default configuration breaks Forbes Magazine, but you
3262 were too lazy to find out which action is the culprit, and you were again too
3263 lazy to give feedback, so you just used the fragile alias on the site, and --
3269 You like the "fun" text replacements in default.filter, but it is disabled in
3270 the distributed actions file. (My colleagues on the team just don't have a
3271 sense of humour, that's why! ;-). So you'd like to turn it on in your private,
3272 update-safe config, once and for all:
3277 Note that the above is not really a good idea: There are exceptions to the
3278 filters in default.action for things that really shouldn't be filtered, like
3279 code on CVS->Web interfaces. Since user.action has the last word, these
3280 exceptions won't be valid for the "fun" filtering specified here.
3282 Finally, you might think about how your favourite free websites are funded, and
3283 find that they rely on displaying banner advertisements to survive. So you
3284 might want to specifically allow banners for those sites that you feel provide
3292 Note that allow-ads has been aliased to -block -filter{banners-by-size} above.
3293 -------------------------------------------------------------------------------
3297 All text substitutions that can be invoked through the filter action must first
3298 be defined in the filter file, which is typically called default.filter and
3299 which can be selected through the filterfile config option.
3301 Typical reasons for doing such substitutions are to eliminate common annoyances
3302 in HTML and JavaScript, such as pop-up windows, exit consoles, crippled windows
3303 without navigation tools, the infamous <BLINK> tag etc, to suppress images with
3304 certain width and height attributes (standard banner sizes or web-bugs), or
3305 just to have fun. The possibilities are endless.
3307 Filtering works on any text-based document type, including plain text, HTML,
3308 JavaScript, CSS etc. (all text/* MIME types). Substitutions are made at the
3309 source level, so if you want to "roll your own" filters, you should be familiar
3312 Just like the actions files, the filter file is organized in sections, which
3313 are called filters here. Each filter consists of a heading line, that starts
3314 with the keyword FILTER:, followed by the filter's name, and a short (one line)
3315 description of what it does. Below that line come the jobs, i.e. lines that
3316 define the actual text substitutions. By convention, the name of a filter
3317 should describe what the filter eliminates. The comment is used in the
3318 web-based user interface.
3320 Once a filter called name has been defined in the filter file, it can be
3321 invoked by using an action of the form +filter{name} in any actions file.
3323 A filter header line for a filter called "foo" could look like this:
3325 FILTER: foo Replace all "foo" with "bar"
3327 Below that line, and up to the next header line, come the jobs that define what
3328 text replacements the filter executes. They are specified in a syntax that
3329 imitates Perl's s/// operator. If you are familiar with Perl, you will find
3330 this to be quite intuitive, and may want to look at the PCRS man page for the
3331 subtle differences to Perl behaviour. Most notably, the non-standard option
3332 letter U is supported, which turns the default to ungreedy matching.
3334 If you are new to regular expressions, you might want to take a look at the
3335 Appendix on regular expressions, and see the Perl manual for the s///
3336 operator's syntax and Perl-style regular expressions in general. The below
3337 examples might also help to get you started.
3338 -------------------------------------------------------------------------------
3340 9.1. Filter File Tutorial
3342 Now, let's complete our "foo" filter. We have already defined the heading, but
3343 the jobs are still missing. Since all it does is to replace "foo" with "bar",
3344 there is only one (trivial) job needed:
3348 But wait! Didn't the comment say that all occurrences of "foo" should be
3349 replaced? Our current job will only take care of the first "foo" on each page.
3350 For global substitution, we'll need to add the g option:
3354 Our complete filter now looks like this:
3356 FILTER: foo Replace all "foo" with "bar"
3359 Let's look at some real filters for more interesting examples. Here you see a
3360 filter that protects against some common annoyances that arise from JavaScript
3361 abuse. Let's look at its jobs one after the other:
3363 FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse
3365 # Get rid of JavaScript referrer tracking. Test page: http://www.randomoddness.com/untitled.htm
3367 s|(<script.*)document\.referrer(.*</script>)|$1"Not Your Business!"$2|Usg
3369 Following the header line and a comment, you see the job. Note that it uses |
3370 as the delimiter instead of /, because the pattern contains a forward slash,
3371 which would otherwise have to be escaped by a backslash (\).
3373 Now, let's examine the pattern: it starts with the text <script.* enclosed in
3374 parentheses. Since the dot matches any character, and * means: "Match an
3375 arbitrary number of the element left of myself", this matches "<script",
3376 followed by any text, i.e. it matches the whole page, from the start of the
3379 That's more than we want, but the pattern continues: document\.referrer matches
3380 only the exact string "document.referrer". The dot needed to be escaped, i.e.
3381 preceded by a backslash, to take away its special meaning as a joker, and make
3382 it just a regular dot. So far, the meaning is: Match from the start of the
3383 first <script> tag in a the page, up to, and including, the text
3384 "document.referrer", if both are present in the page (and appear in that
3387 But there's still more pattern to go. The next element, again enclosed in
3388 parentheses, is .*</script>. You already know what .* means, so the whole
3389 pattern translates to: Match from the start of the first <script> tag in a page
3390 to the end of the last <script> tag, provided that the text "document.referrer"
3391 appears somewhere in between.
3393 This is still not the whole story, since we have ignored the options and the
3394 parentheses: The portions of the page matched by sub-patterns that are enclosed
3395 in parentheses, will be remembered and be available through the variables $1,
3396 $2, ... in the substitute. The U option switches to ungreedy matching, which
3397 means that the first .* in the pattern will only "eat up" all text in between "
3398 <script" and the first occurrence of "document.referrer", and that the second .
3399 * will only span the text up to the first "</script>" tag. Furthermore, the s
3400 option says that the match may span multiple lines in the page, and the g
3401 option again means that the substitution is global.
3403 So, to summarize, the pattern means: Match all scripts that contain the text
3404 "document.referrer". Remember the parts of the script from (and including) the
3405 start tag up to (and excluding) the string "document.referrer" as $1, and the
3406 part following that string, up to and including the closing tag, as $2.
3408 Now the pattern is deciphered, but wasn't this about substituting things? So
3409 lets look at the substitute: $1"Not Your Business!"$2 is easy to read: The text
3410 remembered as $1, followed by "Not Your Business!" (including the quotation
3411 marks!), followed by the text remembered as $2. This produces an exact copy of
3412 the original string, with the middle part (the "document.referrer") replaced by
3413 "Not Your Business!".
3415 The whole job now reads: Replace "document.referrer" by "Not Your Business!"
3416 wherever it appears inside a <script> tag. Note that this job won't break
3417 JavaScript syntax, since both the original and the replacement are
3418 syntactically valid string objects. The script just won't have access to the
3419 referrer information anymore.
3421 We'll show you two other jobs from the JavaScript taming department, but this
3422 time only point out the constructs of special interest:
3424 # The status bar is for displaying link targets, not pointless blahblah
3426 s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig
3428 \s stands for whitespace characters (space, tab, newline, carriage return, form
3429 feed), so that \s* means: "zero or more whitespace". The ? in .*? makes this
3430 matching of arbitrary text ungreedy. (Note that the U option is not set). The
3431 ['"] construct means: "a single or a double quote". Finally, \1 is a
3432 backreference to the first parenthesis just like $1 above, with the difference
3433 that in the pattern, a backslash indicates a backreference, whereas in the
3434 substitute, it's the dollar.
3436 So what does this job do? It replaces assignments of single- or double-quoted
3437 strings to the "window.status" object with a dummy assignment (using a variable
3438 name that is hopefully odd enough not to conflict with real variables in
3439 scripts). Thus, it catches many cases where e.g. pointless descriptions are
3440 displayed in the status bar instead of the link target when you move your mouse
3443 # Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html
3445 s/(<body [^>]*)onunload(.*>)/$1never$2/iU
3447 Including the OnUnload event binding in the HTML DOM was a CRIME. When I close
3448 a browser window, I want it to close and die. Basta. This job replaces the
3449 "onunload" attribute in "<body>" tags with the dummy word never. Note that the
3450 i option makes the pattern matching case-insensitive. Also note that ungreedy
3451 matching alone doesn't always guarantee a minimal match: In the first
3452 parenthesis, we had to use [^>]* instead of .* to prevent the match from
3453 exceeding the <body> tag if it doesn't contain "OnUnload", but the page's
3456 The last example is from the fun department:
3458 FILTER: fun Fun text replacements
3460 # Spice the daily news:
3462 s/microsoft(?!\.com)/MicroSuck/ig
3464 Note the (?!\.com) part (a so-called negative lookahead) in the job's pattern,
3465 which means: Don't match, if the string ".com" appears directly following
3466 "microsoft" in the page. This prevents links to microsoft.com from being
3467 trashed, while still replacing the word everywhere else.
3469 # Buzzword Bingo (example for extended regex syntax)
3471 s* industry[ -]leading \
3473 | customer[ -]focused \
3474 | market[ -]driven \
3475 | award[ -]winning # Comments are OK, too! \
3476 | high[ -]performance \
3477 | solutions[ -]based \
3481 *<font color="red"><b>BINGO!</b></font> \
3484 The x option in this job turns on extended syntax, and allows for e.g. the
3485 liberal use of (non-interpreted!) whitespace for nicer formatting.
3488 -------------------------------------------------------------------------------
3492 All Privoxy built-in pages, i.e. error pages such as the "404 - No Such Domain"
3493 error page, the "BLOCKED" page and all pages of its web-based user interface,
3494 are generated from templates. (Privoxy must be running for the above links to
3497 These templates are stored in a subdirectory of the configuration directory
3498 called templates. On Unixish platforms, this is typically /etc/privoxy/
3501 The templates are basically normal HTML files, but with place-holders (called
3502 symbols or exports), which Privoxy fills at run time. You can edit the
3503 templates with a normal text editor, should you want to customize them. (Not
3504 recommended for the casual user). Note that just like in configuration files,
3505 lines starting with # are ignored when the templates are filled in.
3507 The place-holders are of the form @name@, and you will find a list of available
3508 symbols, which vary from template to template, in the comments at the start of
3509 each file. Note that these comments are not always accurate, and that it's
3510 probably best to look at the existing HTML code to find out which symbols are
3511 supported and what they are filled in with.
3513 A special application of this substitution mechanism is to make whole blocks of
3514 HTML code disappear when a specific symbol is set. We use this for many
3515 purposes, one of them being to include the beta warning in all our user
3516 interface (CGI) pages when Privoxy in in an alpha or beta development stage:
3518 <!-- @if-unstable-start -->
3520 ... beta warning HTML code goes here ...
3522 <!-- if-unstable-end@ -->
3524 If the "unstable" symbol is set, everything in between and including
3525 @if-unstable-start and if-unstable-end@ will disappear, leaving nothing but an
3530 There's also an if-then-else construct and an #include mechanism, but you'll
3531 sure find out if you are inclined to edit the templates ;-)
3533 All templates refer to a style located at http://config.privoxy.org/
3534 send-stylesheet. This is, of course, locally served by Privoxy and the source
3535 for it can be found and edited in the cgi-style.css template.
3536 -------------------------------------------------------------------------------
3538 11. Contacting the Developers, Bug Reporting and Feature Requests
3540 We value your feedback. In fact, we rely on it to improve Privoxy and its
3541 configuration. However, please note the following hints, so we can provide you
3542 with the best support:
3543 -------------------------------------------------------------------------------
3547 For casual users, our support forum at SourceForge is probably best suited:
3548 http://sourceforge.net/tracker/?group_id=11118&atid=211118
3550 All users are of course welcome to discuss their issues on the users mailing
3551 list, where the developers also hang around.
3552 -------------------------------------------------------------------------------
3556 Please report all bugs only through our bug tracker: http://sourceforge.net/
3557 tracker/?group_id=11118&atid=111118.
3559 Before doing so, please make sure that the bug has not already been submitted
3560 and observe the additional hints at the top of the submit form.
3562 Please try to verify that it is a Privoxy bug, and not a browser or site bug
3563 first. If unsure, try toggling off Privoxy, and see if the problem persists.
3564 The appendix of the user manual also has helpful information on action
3565 debugging. If you are using your own custom configuration, please try the stock
3566 configs to see if the problem is configuration related.
3568 If not using the latest version, chances are that the bug has been found and
3569 fixed in the meantime. We would appreciate if you could take the time to
3570 upgrade to the latest version (or even the latest CVS snapshot) and verify your
3571 bug, but this is not required for reporting.
3572 -------------------------------------------------------------------------------
3574 11.3. Request New Features
3576 You are welcome to submit ideas on new features or other proposals for
3577 improvement through our feature request tracker at http://sourceforge.net/
3578 tracker/?atid=361118&group_id=11118.
3579 -------------------------------------------------------------------------------
3581 11.4. Report Ads or Other Actions-Related Problems
3583 Please send feedback on ads that slipped through, innocent images that were
3584 blocked, and any other problems relating to the default.action file through our
3585 actions feedback mechanism located at http://www.privoxy.org/actions/. On this
3586 page, you will also find a bookmark which will take you back there from any
3587 troubled site and even pre-fill the form!
3589 New, improved default.action files will occasionally be made available based on
3590 your feedback. These will be announced on the ijbswa-announce list and
3591 available from our the files section of our project page.
3592 -------------------------------------------------------------------------------
3596 For any other issues, feel free to use the mailing lists. Technically
3597 interested users and people who wish to contribute to the project are also
3598 welcome on the developers list! You can find an overview of all Privoxy-related
3599 mailing lists, including list archives, at: http://sourceforge.net/mail/?
3601 -------------------------------------------------------------------------------
3603 12. Privoxy Copyright, License and History
3605 Copyright © 2001, 2002 by Privoxy Developers <developers@privoxy.org>
3607 Some source code is based on code Copyright © 1997 by Anonymous Coders and
3608 Junkbusters, Inc. and licensed under the GNU General Public License.
3609 -------------------------------------------------------------------------------
3613 Privoxy is free software; you can redistribute it and/or modify it under the
3614 terms of the GNU General Public License, version 2, as published by the Free
3615 Software Foundation.
3617 This program is distributed in the hope that it will be useful, but WITHOUT ANY
3618 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
3619 PARTICULAR PURPOSE. See the GNU General Public License for more details, which
3620 is available from the Free Software Foundation, Inc, 59 Temple Place - Suite
3621 330, Boston, MA 02111-1307, USA.
3623 You should have received a copy of the GNU General Public License along with
3624 this program; if not, write to the
3627 Foundation, Inc. 59 Temple Place - Suite 330
3628 Boston, MA 02111-1307
3630 -------------------------------------------------------------------------------
3634 In the beginning, there was the Internet Junkbuster, by Anonymous Coders and
3635 Junkbusters Corporation. It saved many users a lot of pain in the early days of
3636 web advertising and user tracking.
3638 But the web, its protocols and standards, and with it, the techniques for
3639 forcing users to consume ads, give up autonomy over their browsing, and for
3640 spying on them, kept evolving. Unfortunately, the Internet Junkbuster did not.
3641 Version 2.0.2, published in 1998, was (and is) the last official release
3642 available from Junkbusters Corporation. Fortunately, it had been released under
3643 the GNU GPL, which allowed further development by others.
3645 So Stefan Waldherr started maintaining an improved version of the software, to
3646 which eventually a number of people contributed patches. It could already
3647 replace banners with a transparent image, and had a first version of pop-up
3648 killing, but it was still very closely based on the original, with all its
3649 limitations, such as the lack of HTTP/1.1 support, flexible per-site
3650 configuration, or content modification. The last release from this effort was
3651 version 2.0.2-10, published in 2000.
3653 Then, some developers picked up the thread, and started turning the software
3654 inside out, upside down, and then reassembled it, adding many new features
3657 The result of this is Privoxy, whose first stable release, 3.0, is due late
3658 summer or early fall 2002.
3659 -------------------------------------------------------------------------------
3663 Current Project Developers:
3672 Current Project Contributors:
3674 Rodrigo Barbosa (RPM specfiles)
3683 David Schmidt (OS/2, Mac OSX ports)
3687 Based in part on code originally developed by:
3692 Thanks to the many people who have tested Privoxy, reported bugs, or made
3693 suggestions. These include (in alphabetical order):
3710 -------------------------------------------------------------------------------
3714 Other references and sites of interest to Privoxy users:
3716 http://www.privoxy.org/, the Privoxy Home page.
3718 http://www.privoxy.org/faq/, the Privoxy FAQ.
3720 http://sourceforge.net/projects/ijbswa/, the Project Page for Privoxy on
3723 http://config.privoxy.org/, the web-based user interface. Privoxy must be
3724 running for this to work. Shortcut: http://p.p/
3726 http://www.privoxy.org/actions/, to submit "misses" to the developers.
3728 http://www.junkbusters.com/ht/en/cookies.html, an explanation how cookies are
3729 used to track web users.
3731 http://www.junkbusters.com/ijb.html, the original Internet Junkbuster.
3733 http://www.waldherr.org/junkbuster/, Stefan Waldherr's version of Junkbuster,
3734 from which Privoxy was derived.
3736 http://privacy.net/analyze/, a useful site to check what information about you
3737 is leaked while you browse the web.
3739 http://www.squid-cache.org/, a very popular caching proxy, which is often used
3740 together with Privoxy.
3742 http://www.privoxy.org/developer-manual/, the Privoxy developer manual.
3744 -------------------------------------------------------------------------------
3747 14.1. Regular Expressions
3749 Privoxy uses Perl-style "regular expressions" in its actions files and filter
3750 file, through the PCRE and PCRS libraries.
3752 If you are reading this, you probably don't understand what "regular
3753 expressions" are, or what they can do. So this will be a very brief
3754 introduction only. A full explanation would require a book ;-)
3756 Regular expressions provide a language to describe patterns that can be run
3757 against strings of characters (letter, numbers, etc), to see if they match the
3758 string or not. The patterns are themselves (sometimes complex) strings of
3759 literal characters, combined with wild-cards, and other special characters,
3760 called meta-characters. The "meta-characters" have special meanings and are
3761 used to build complex patterns to be matched against. Perl Compatible Regular
3762 Expressions are an especially convenient "dialect" of the regular expression
3765 To make a simple analogy, we do something similar when we use wild-card
3766 characters when listing files with the dir command in DOS. *.* matches all
3767 filenames. The "special" character here is the asterisk which matches any and
3768 all characters. We can be more specific and use ? to match just individual
3769 characters. So "dir file?.text" would match "file1.txt", "file2.txt", etc. We
3770 are pattern matching, using a similar technique to "regular expressions"!
3772 Regular expressions do essentially the same thing, but are much, much more
3773 powerful. There are many more "special characters" and ways of building complex
3774 patterns however. Let's look at a few of the common ones, and then some
3777 . - Matches any single character, e.g. "a", "A", "4", ":", or "@".
3779 ? - The preceding character or expression is matched ZERO or ONE times. Either/
3782 + - The preceding character or expression is matched ONE or MORE times.
3784 * - The preceding character or expression is matched ZERO or MORE times.
3786 \ - The "escape" character denotes that the following character should be taken
3787 literally. This is used where one of the special characters (e.g. ".") needs to
3788 be taken literally and not as a special meta-character. Example: "example\.com"
3789 , makes sure the period is recognized only as a period (and not expanded to its
3790 meta-character meaning of any single character).
3792 [] - Characters enclosed in brackets will be matched if any of the enclosed
3793 characters are encountered. For instance, "[0-9]" matches any numeric digit
3794 (zero through nine). As an example, we can combine this with "+" to match any
3795 digit one of more times: "[0-9]+".
3797 () - parentheses are used to group a sub-expression, or multiple
3800 | - The "bar" character works like an "or" conditional statement. A match is
3801 successful if the sub-expression on either side of "|" matches. As an example:
3802 "/(this|that) example/" uses grouping and the bar character and would match
3803 either "this example" or "that example", and nothing else.
3805 These are just some of the ones you are likely to use when matching URLs with
3806 Privoxy, and is a long way from a definitive list. This is enough to get us
3807 started with a few simple examples which may be more illuminating:
3809 /.*/banners/.* - A simple example that uses the common combination of "." and "
3810 *" to denote any character, zero or more times. In other words, any string at
3811 all. So we start with a literal forward slash, then our regular expression
3812 pattern (".*") another literal forward slash, the string "banners", another
3813 forward slash, and lastly another ".*". We are building a directory path here.
3814 This will match any file with the path that has a directory named "banners" in
3815 it. The ".*" matches any characters, and this could conceivably be more forward
3816 slashes, so it might expand into a much longer looking path. For example, this
3817 could match: "/eye/hate/spammers/banners/annoy_me_please.gif", or just "/
3818 banners/annoying.html", or almost an infinite number of other possible
3819 combinations, just so it has "banners" in the path somewhere.
3821 A now something a little more complex:
3823 /.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward
3824 slashes again ("/"), so we are building another expression that is a file path
3825 statement. We have another ".*", so we are matching against any conceivable
3826 sub-path, just so it matches our expression. The only true literal that must
3827 match our pattern is adv, together with the forward slashes. What comes after
3828 the "adv" string is the interesting part.
3830 Remember the "?" means the preceding expression (either a literal character or
3831 anything grouped with "(...)" in this case) can exist or not, since this means
3832 either zero or one match. So "((er)?ts?|ertis(ing|ements?))" is optional, as
3833 are the individual sub-expressions: "(er)", "(ing|ements?)", and the "s". The "
3834 |" means "or". We have two of those. For instance, "(ing|ements?)", can expand
3835 to match either "ing" OR "ements?". What is being done here, is an attempt at
3836 matching as many variations of "advertisement", and similar, as possible. So
3837 this would expand to match just "adv", or "advert", or "adverts", or
3838 "advertising", or "advertisement", or "advertisements". You get the idea. But
3839 it would not match "advertizements" (with a "z"). We could fix that by changing
3840 our regular expression to: "/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/", which
3841 would then match either spelling.
3843 /.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward
3844 slashes. Anything in the square brackets "[]" can be matched. This is using
3845 "0-9" as a shorthand expression to mean any digit one through nine. It is the
3846 same as saying "0123456789". So any digit matches. The "+" means one or more of
3847 the preceding expression must be included. The preceding expression here is
3848 what is in the square brackets -- in this case, any digit one through nine.
3849 Then, at the end, we have a grouping: "(gif|jpe?g)". This includes a "|", so
3850 this needs to match the expression on either side of that bar character also. A
3851 simple "gif" on one side, and the other side will in turn match either "jpeg"
3852 or "jpg", since the "?" means the letter "e" is optional and can be matched
3853 once or not at all. So we are building an expression here to match image GIF or
3854 JPEG type image file. It must include the literal string "advert", then one or
3855 more digits, and a "." (which is now a literal, and not a special character,
3856 since it is escaped with "\"), and lastly either "gif", or "jpeg", or "jpg".
3857 Some possible matches would include: "//advert1.jpg", "/nasty/ads/
3858 advert1234.gif", "/banners/from/hell/advert99.jpg". It would not match
3859 "advert1.gif" (no leading slash), or "/adverts232.jpg" (the expression does not
3860 include an "s"), or "/advert1.jsp" ("jsp" is not in the expression anywhere).
3862 We are barely scratching the surface of regular expressions here so that you
3863 can understand the default Privoxy configuration files, and maybe use this
3864 knowledge to customize your own installation. There is much, much more that can
3865 be done with regular expressions. Now that you know enough to get started, you
3866 can learn more on your own :/
3868 More reading on Perl Compatible Regular expressions: http://www.perldoc.com/
3869 perl5.6/pod/perlre.html
3871 For information on regular expression based substitutions and their
3872 applications in filters, please see the filter file tutorial in this manual.
3873 -------------------------------------------------------------------------------
3875 14.2. Privoxy's Internal Pages
3877 Since Privoxy proxies each requested web page, it is easy for Privoxy to trap
3878 certain special URLs. In this way, we can talk directly to Privoxy, and see how
3879 it is configured, see how our rules are being applied, change these rules and
3880 other configuration options, and even turn Privoxy's filtering off, all with a
3883 The URLs listed below are the special ones that allow direct access to Privoxy.
3884 Of course, Privoxy must be running to access these. If not, you will get a
3885 friendly error message. Internet access is not necessary either.
3887 * Privoxy main page:
3890 http://config.privoxy.org/
3893 There is a shortcut: http://p.p/ (But it doesn't provide a fall-back to a
3894 real page, in case the request is not sent through Privoxy)
3896 * Show information about the current configuration, including viewing and
3897 editing of actions files:
3900 http://config.privoxy.org/show-status
3903 * Show the source code version numbers:
3906 http://config.privoxy.org/show-version
3909 * Show the browser's request headers:
3912 http://config.privoxy.org/show-request
3915 * Show which actions apply to a URL and why:
3918 http://config.privoxy.org/show-url-info
3921 * Toggle Privoxy on or off. In this case, "Privoxy" continues to run, but
3922 only as a pass-through proxy, with no actions taking place:
3925 http://config.privoxy.org/toggle
3928 Short cuts. Turn off, then on:
3931 http://config.privoxy.org/toggle?set=disable
3935 http://config.privoxy.org/toggle?set=enable
3939 These may be bookmarked for quick reference. See next.
3940 -------------------------------------------------------------------------------
3942 14.2.1. Bookmarklets
3944 Below are some "bookmarklets" to allow you to easily access a "mini" version of
3945 some of Privoxy's special pages. They are designed for MS Internet Explorer,
3946 but should work equally well in Netscape, Mozilla, and other browsers which
3947 support JavaScript. They are designed to run directly from your bookmarks - not
3948 by clicking the links below (although that should work for testing).
3950 To save them, right-click the link and choose "Add to Favorites" (IE) or "Add
3951 Bookmark" (Netscape). You will get a warning that the bookmark "may not be
3952 safe" - just click OK. Then you can run the Bookmarklet directly from your
3953 favorites/bookmarks. For even faster access, you can put them on the "Links"
3954 bar (IE) or the "Personal Toolbar" (Netscape), and run them with a single
3961 * Privoxy - Toggle Privoxy (Toggles between enabled and disabled)
3963 * Privoxy- View Status
3965 * Privoxy - Submit Actions File Feedback
3970 Credit: The site which gave us the general idea for these bookmarklets is
3971 www.bookmarklets.com. They have more information about bookmarklets.
3972 -------------------------------------------------------------------------------
3974 14.3. Chain of Events
3976 Let's take a quick look at the basic sequence of events when a web page is
3977 requested by your browser and Privoxy is on duty:
3979 * First, your web browser requests a web page. The browser knows to send the
3980 request to Privoxy, which will in turn, relay the request to the remote web
3981 server after passing the following tests:
3983 * Privoxy traps any request for its own internal CGI pages (e.g http://p.p/)
3984 and sends the CGI page back to the browser.
3986 * Next, Privoxy checks to see if the URL matches any "+block" patterns. If
3987 so, the URL is then blocked, and the remote web server will not be
3988 contacted. "+handle-as-image" is then checked and if it does not match, an
3989 HTML "BLOCKED" page is sent back. Otherwise, if it does match, an image is
3990 returned. The type of image depends on the setting of "+set-image-blocker"
3991 (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
3993 * Untrusted URLs are blocked. If URLs are being added to the trust file, then
3996 * If the URL pattern matches the "+fast-redirects" action, it is then
3997 processed. Unwanted parts of the requested URL are stripped.
3999 * Now the rest of the client browser's request headers are processed. If any
4000 of these match any of the relevant actions (e.g. "+hide-user-agent", etc.),
4001 headers are suppressed or forged as determined by these actions and their
4004 * Now the web server starts sending its response back (i.e. typically a web
4005 page and related data).
4007 * First, the server headers are read and processed to determine, among other
4008 things, the MIME type (document type) and encoding. The headers are then
4009 filtered as deterimined by the "+crunch-incoming-cookies",
4010 "+session-cookies-only", and "+downgrade-http-version" actions.
4012 * If the "+kill-popups" action applies, and it is an HTML or JavaScript
4013 document, the popup-code in the response is filtered on-the-fly as it is
4016 * If a "+filter" or "+deanimate-gifs" action applies (and the document type
4017 fits the action), the rest of the page is read into memory (up to a
4018 configurable limit). Then the filter rules (from default.filter) are
4019 processed against the buffered content. Filters are applied in the order
4020 they are specified in the default.filter file. Animated GIFs, if present,
4021 are reduced to either the first or last frame, depending on the action
4022 setting.The entire page, which is now filtered, is then sent by Privoxy
4023 back to your browser.
4025 If neither "+filter" or "+deanimate-gifs" matches, then Privoxy passes the
4026 raw data through to the client browser as it becomes available.
4028 * As the browser receives the now (probably filtered) page content, it reads
4029 and then requests any URLs that may be embedded within the page source,
4030 e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
4031 frames), sounds, etc. For each of these objects, the browser issues a new
4032 request. And each such request is in turn processed as above. Note that a
4033 complex web page may have many such embedded URLs.
4036 -------------------------------------------------------------------------------
4037 14.4. Anatomy of an Action
4039 The way Privoxy applies actions and filters to any given URL can be complex,
4040 and not always so easy to understand what is happening. And sometimes we need
4041 to be able to see just what Privoxy is doing. Especially, if something Privoxy
4042 is doing is causing us a problem inadvertently. It can be a little daunting to
4043 look at the actions and filters files themselves, since they tend to be filled
4044 with regular expressions whose consequences are not always so obvious.
4046 One quick test to see if Privoxy is causing a problem or not, is to disable it
4047 temporarily. This should be the first troubleshooting step. See the
4048 Bookmarklets section on a quick and easy way to do this (be sure to flush
4049 caches afterward!). Looking at the logs is a good idea too.
4051 Privoxy also provides the http://config.privoxy.org/show-url-info page that can
4052 show us very specifically how actions are being applied to any given URL. This
4053 is a big help for troubleshooting.
4055 First, enter one URL (or partial URL) at the prompt, and then Privoxy will tell
4056 us how the current configuration will handle it. This will not help with
4057 filtering effects (i.e. the "+filter" action) from the default.filter file
4058 since this is handled very differently and not so easy to trap! It also will
4059 not tell you about any other URLs that may be embedded within the URL you are
4060 testing. For instance, images such as ads are expressed as URLs within the raw
4061 page source of HTML pages. So you will only get info for the actual URL that is
4062 pasted into the prompt area -- not any sub-URLs. If you want to know about
4063 embedded URLs like ads, you will have to dig those out of the HTML source. Use
4064 your browser's "View Page Source" option for this. Or right click on the ad,
4067 Let's try an example, google.com, and look at it one section at a time:
4069 Matches for http://google.com:
4071 In file: default.action [ View ] [ Edit ]
4075 -crunch-outgoing-cookies
4076 -crunch-incoming-cookies
4077 +deanimate-gifs{last}
4078 -downgrade-http-version
4082 -filter{shockwave-flash}
4083 -filter{crude-parental}
4084 +filter{html-annoyances}
4085 +filter{js-annoyances}
4086 +filter{content-cookies}
4088 +filter{refresh-tags}
4090 +filter{banners-by-size}
4091 +hide-forwarded-for-headers
4092 +hide-from-header{block}
4093 +hide-referer{forge}
4098 +prevent-compression
4101 +session-cookies-only
4102 +set-image-blocker{pattern} }
4105 { -session-cookies-only }
4111 In file: user.action [ View ] [ Edit ]
4112 (no matches in this file)
4114 This tells us how we have defined our "actions", and which ones match for our
4115 example, "google.com". The first listing is any matches for the standard.action
4116 file. No hits at all here on "standard". Then next is "default", or our
4117 default.action file. The large, multi-line listing, is how the actions are set
4118 to match for all URLs, i.e. our default settings. If you look at your "actions"
4119 file, this would be the section just below the "aliases" section near the top.
4120 This will apply to all URLs as signified by the single forward slash at the end
4121 of the listing -- "/".
4123 But we can define additional actions that would be exceptions to these general
4124 rules, and then list specific URLs (or patterns) that these exceptions would
4125 apply to. Last match wins. Just below this then are two explicit matches for
4126 ".google.com". The first is negating our previous cookie setting, which was for
4127 "+session-cookies-only" (i.e. not persistent). So we will allow persistent
4128 cookies for google. The second turns off any "+fast-redirects" action, allowing
4129 this to take place unmolested. Note that there is a leading dot here --
4130 ".google.com". This will match any hosts and sub-domains, in the google.com
4131 domain also, such as "www.google.com". So, apparently, we have these two
4132 actions defined somewhere in the lower part of our default.action file, and
4133 "google.com" is referenced somewhere in these latter sections.
4135 Then, for our user.action file, we again have no hits.
4137 And finally we pull it all together in the bottom section and summarize how
4138 Privoxy is applying all its "actions" to "google.com":
4144 -crunch-outgoing-cookies
4145 -crunch-incoming-cookies
4146 +deanimate-gifs{last}
4147 -downgrade-http-version
4151 -filter{shockwave-flash}
4152 -filter{crude-parental}
4153 +filter{html-annoyances}
4154 +filter{js-annoyances}
4155 +filter{content-cookies}
4157 +filter{refresh-tags}
4159 +filter{banners-by-size}
4160 +hide-forwarded-for-headers
4161 +hide-from-header{block}
4162 +hide-referer{forge}
4167 +prevent-compression
4170 -session-cookies-only
4171 +set-image-blocker{pattern}
4173 Notice the only difference here to the previous listing, is to "fast-redirects"
4174 and "session-cookies-only".
4176 Now another example, "ad.doubleclick.net":
4178 { +block +handle-as-image }
4181 { +block +handle-as-image }
4184 { +block +handle-as-image }
4187 We'll just show the interesting part here, the explicit matches. It is matched
4188 three different times. Each as an "+block +handle-as-image", which is the
4189 expanded form of one of our aliases that had been defined as: "+imageblock". (
4190 "Aliases" are defined in the first section of the actions file and typically
4191 used to combine more than one action.)
4193 Any one of these would have done the trick and blocked this as an unwanted
4194 image. This is unnecessarily redundant since the last case effectively would
4195 also cover the first. No point in taking chances with these guys though ;-)
4196 Note that if you want an ad or obnoxious URL to be invisible, it should be
4197 defined as "ad.doubleclick.net" is done here -- as both a "+block" and an
4198 "+handle-as-image". The custom alias "+imageblock" just simplifies the process
4199 and make it more readable.
4201 One last example. Let's try "http://www.rhapsodyk.net/adsl/HOWTO/". This one is
4202 giving us problems. We are getting a blank page. Hmmm ...
4204 Matches for http://www.rhapsodyk.net/adsl/HOWTO/:
4206 In file: default.action [ View ] [ Edit ]
4210 -crunch-incoming-cookies
4211 -crunch-outgoing-cookies
4213 -downgrade-http-version
4215 +filter{html-annoyances}
4216 +filter{js-annoyances}
4217 +filter{kill-popups}
4220 +filter{banners-by-size}
4223 +hide-forwarded-for-headers
4224 +hide-from-header{block}
4225 +hide-referer{forge}
4229 +prevent-compression
4232 +session-cookies-only
4233 +set-image-blocker{blank} }
4236 { +block +handle-as-image }
4239 Ooops, the "/adsl/" is matching "/ads"! But we did not want this at all! Now we
4240 see why we get the blank page. We could now add a new action below this that
4241 explicitly does not block ("{-block}") paths with "adsl". There are various
4242 ways to handle such exceptions. Example:
4247 Now the page displays ;-) Be sure to flush your browser's caches when making
4248 such changes. Or, try using Shift+Reload.
4250 But now what about a situation where we get no explicit matches like we did
4253 { +block +handle-as-image }
4256 That actually was very telling and pointed us quickly to where the problem was.
4257 If you don't get this kind of match, then it means one of the default rules in
4258 the first section is causing the problem. This would require some guesswork,
4259 and maybe a little trial and error to isolate the offending rule. One likely
4260 cause would be one of the "{+filter}" actions. These tend to be harder to
4261 troubleshoot. Try adding the URL for the site to one of aliases that turn off
4266 .worldpay.com # for quietpc.com
4271 "{shop}" is an "alias" that expands to "{ -filter -session-cookies-only }". Or
4272 you could do your own exception to negate filtering:
4277 This would turn off all filtering for that site. This would probably be most
4278 appropriately put in user.action, for local site exceptions.
4280 Images that are inexplicably being blocked, may well be hitting the "+filter
4281 {banners-by-size}" rule, which assumes that images of certain sizes are ad
4282 banners (works well most of the time since these tend to be standardized).
4284 "{fragile}" is an alias that disables most actions. This can be used as a last
4285 resort for problem sites. Remember to flush caches! If this still does not
4286 work, you will have to go through the remaining actions one by one to find
4287 which one(s) is causing the problem.
projects / privoxy.git / blob