1 Privoxy 3.0.1 User Manual
3 Copyright © 2001, 2002 by Privoxy Developers
5 $Id: user-manual.sgml,v 1.123.2.27 2003/03/18 19:37:14 oes Exp $
7 The User Manual gives users information on how to install, configure and use
10 Privoxy is a web proxy with advanced filtering capabilities for protecting
11 privacy, filtering web page content, managing cookies, controlling access, and
12 removing ads, banners, pop-ups and other obnoxious Internet junk. Privoxy has a
13 very flexible configuration and can be customized to suit individual needs and
14 tastes. Privoxy has application for both stand-alone systems and multi-user
17 Privoxy is based on Internet Junkbuster (tm).
19 You can find the latest version of the User Manual at http://www.privoxy.org/
20 user-manual/. Please see the Contact section on how to contact the developers.
22 -------------------------------------------------------------------------------
33 2.1.1. Red Hat, SuSE and Conectiva RPMs
36 2.1.4. Solaris, NetBSD, FreeBSD, HP-UX
42 2.2. Building from Source
43 2.3. Keeping your Installation Up-to-Date
46 4. Quickstart to Using Privoxy
48 4.1. Quickstart to Ad Blocking
52 5.1. Red Hat and Conectiva
56 5.5. Solaris, NetBSD, FreeBSD, HP-UX and others
61 5.10. Command Line Options
63 6. Privoxy Configuration
65 6.1. Controlling Privoxy with Your Web Browser
66 6.2. Configuration Files Overview
68 7. The Main Configuration File
70 7.1. Configuration and Log File Locations
80 7.2. Local Set-up Documentation
90 7.3.2. single-threaded
92 7.4. Access Control and Security
96 7.4.3. enable-remote-toggle
97 7.4.4. enable-edit-actions
98 7.4.5. ACLs: permit-access and deny-access
104 7.5.2. forward-socks4 and forward-socks4a
105 7.5.3. Advanced Forwarding Examples
107 7.6. Windows GUI Options
111 8.1. Finding the Right Mix
113 8.3. How Actions are Applied to URLs
116 8.4.1. The Domain Pattern
117 8.4.2. The Path Pattern
123 8.5.3. crunch-incoming-cookies
124 8.5.4. crunch-outgoing-cookies
125 8.5.5. deanimate-gifs
126 8.5.6. downgrade-http-version
127 8.5.7. fast-redirects
129 8.5.9. handle-as-image
130 8.5.10. hide-forwarded-for-headers
131 8.5.11. hide-from-header
132 8.5.12. hide-referrer
133 8.5.13. hide-user-agent
135 8.5.15. limit-connect
136 8.5.16. prevent-compression
137 8.5.17. send-vanilla-wafer
139 8.5.19. session-cookies-only
140 8.5.20. set-image-blocker
144 8.7. Actions Files Tutorial
146 8.7.1. default.action
151 9.1. Filter File Tutorial
154 11. Contacting the Developers, Bug Reporting and Feature Requests
158 11.3. Request New Features
159 11.4. Report Ads or Other Actions-Related Problems
162 12. Privoxy Copyright, License and History
171 14.1. Regular Expressions
172 14.2. Privoxy's Internal Pages
176 14.3. Chain of Events
177 14.4. Anatomy of an Action
181 This documentation is included with the current stable version of Privoxy,
184 -------------------------------------------------------------------------------
188 In addition to Internet Junkbuster's traditional features of ad and banner
189 blocking and cookie management, Privoxy provides new features:
191 * Integrated browser based configuration and control utility at http://
192 config.privoxy.org/ (shortcut: http://p.p/). Browser-based tracing of rule
193 and filter effects. Remote toggling.
195 * Web page content filtering (removes banners based on size, invisible
196 "web-bugs", JavaScript and HTML annoyances, pop-up windows, etc.)
198 * Modularized configuration that allows for standard settings and user
199 settings to reside in separate files, so that installing updated actions
200 files won't overwrite individual user settings.
202 * HTTP/1.1 compliant (but not all optional 1.1 features are supported).
204 * Support for Perl Compatible Regular Expressions in the configuration files,
205 and generally a more sophisticated and flexible configuration syntax over
208 * Improved cookie management features (e.g. session based cookies).
212 * Bypass many click-tracking scripts (avoids script redirection).
214 * Multi-threaded (POSIX and native threads).
216 * User-customizable HTML templates for all proxy-generated pages (e.g.
219 * Auto-detection and re-reading of config file changes.
221 * Improved signal handling, and a true daemon mode (Unix).
223 * Every feature now controllable on a per-site or per-location basis,
224 configuration more powerful and versatile over-all.
226 * Many smaller new features added, limitations and bugs removed, and security
229 -------------------------------------------------------------------------------
233 Privoxy is available both in convenient pre-compiled packages for a wide range
234 of operating systems, and as raw source code. For most users, we recommend
235 using the packages, which can be downloaded from our Privoxy Project Page.
237 Note: If you have a previous Junkbuster or Privoxy installation on your system,
238 you will need to remove it. On some platforms, this may be done for you as part
239 of their installation procedure. (See below for your platform). In any case be
240 sure to backup your old configuration if it is valuable to you. See the note to
241 upgraders section below.
243 -------------------------------------------------------------------------------
247 How to install the binary packages depends on your operating system:
249 -------------------------------------------------------------------------------
251 2.1.1. Red Hat, SuSE and Conectiva RPMs
253 RPMs can be installed with rpm -Uvh privoxy-3.0.1-1.rpm, and will use /etc/
254 privoxy for the location of configuration files.
256 Note that on Red Hat, Privoxy will not be automatically started on system boot.
257 You will need to enable that using chkconfig, ntsysv, or similar methods. Note
258 that SuSE will automatically start Privoxy in the boot process.
260 If you have problems with failed dependencies, try rebuilding the SRC RPM: rpm
261 --rebuild privoxy-3.0.1-1.src.rpm. This will use your locally installed
262 libraries and RPM version.
264 Also note that if you have a Junkbuster RPM installed on your system, you need
265 to remove it first, because the packages conflict. Otherwise, RPM will try to
266 remove Junkbuster automatically, before installing Privoxy.
268 -------------------------------------------------------------------------------
272 DEBs can be installed with dpkg -i privoxy_3.0.1-1.deb, and will use /etc/
273 privoxy for the location of configuration files.
275 -------------------------------------------------------------------------------
279 Just double-click the installer, which will guide you through the installation
280 process. You will find the configuration files in the same directory as you
281 installed Privoxy in. We do not use the registry of Windows.
283 -------------------------------------------------------------------------------
285 2.1.4. Solaris, NetBSD, FreeBSD, HP-UX
287 Create a new directory, cd to it, then unzip and untar the archive. For the
288 most part, you'll have to figure out where things go.
290 -------------------------------------------------------------------------------
294 First, make sure that no previous installations of Junkbuster and / or Privoxy
295 are left on your system. Check that no Junkbuster or Privoxy objects are in
298 Then, just double-click the WarpIN self-installing archive, which will guide
299 you through the installation process. A shadow of the Privoxy executable will
300 be placed in your startup folder so it will start automatically whenever OS/2
303 The directory you choose to install Privoxy into will contain all of the
306 -------------------------------------------------------------------------------
310 Unzip the downloaded file (you can either double-click on the file from the
311 finder, or from the desktop if you downloaded it there). Then, double-click on
312 the package installer icon named Privoxy.pkg and follow the installation
313 process. Privoxy will be installed in the folder /Library/Privoxy. It will
314 start automatically whenever you start up. To prevent it from starting
315 automatically, remove or rename the folder /Library/StartupItems/Privoxy.
317 To start Privoxy by hand, double-click on StartPrivoxy.command in the /Library/
318 Privoxy folder. Or, type this command in the Terminal:
320 /Library/Privoxy/StartPrivoxy.command
323 You will be prompted for the administrator password.
325 -------------------------------------------------------------------------------
329 Copy and then unpack the lha archive to a suitable location. All necessary
330 files will be installed into Privoxy directory, including all configuration and
331 log files. To uninstall, just remove this directory.
333 -------------------------------------------------------------------------------
337 Gentoo source packages (Ebuilds) for Privoxy are contained in the Gentoo
338 Portage Tree (they are not on the download page, but there is a Gentoo section,
339 where you can see when a new Privoxy Version is added to the Portage Tree).
341 Before installing Privoxy under Gentoo just do first emerge rsync to get the
342 latest changes from the Portage tree. With emerge privoxy you install the
345 Configuration files are in /etc/privoxy, the documentation is in /usr/share/doc
346 /privoxy-3.0.1 and the Log directory is in /var/log/privoxy.
348 -------------------------------------------------------------------------------
350 2.2. Building from Source
352 The most convenient way to obtain the Privoxy sources is to download the source
353 tarball from our project page.
355 If you like to live on the bleeding edge and are not afraid of using possibly
356 unstable development versions, you can check out the up-to-the-minute version
357 directly from the CVS repository or simply download the nightly CVS tarball.
359 To build Privoxy from source, autoconf, GNU make (gmake), and, of course, a C
360 compiler like gcc are required.
362 When building from a source tarball (either release version or nightly CVS
363 tarball), first unpack the source:
365 tar xzvf privoxy-3.0.1-src* [.tgz or .tar.gz]
368 For retrieving the current CVS sources, you'll need CVS installed. Note that
369 sources from CVS are development quality, and may not be stable, or well
370 tested. To download CVS source:
372 cvs -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa login
373 cvs -z3 -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa co current
376 This will create a directory named current/, which will contain the source
379 You can also check out any Privoxy "branch", just exchange the current name
380 with the wanted branch name (Example: v_3_0_branch for the 3.0 cvs tree).
382 It is also strongly recommended to not run Privoxy as root, and instead it is
383 suggested to create a "privoxy" user and group for this purpose. See your local
384 documentation for the correct command line to do this.
386 /etc/passwd might then look like:
388 privoxy:*:7777:7777:privoxy proxy:/no/home:/no/shell
390 And then /etc/group, like:
394 Some binary packages may do this for you.
396 Then, to build from either unpacked tarball or CVS source:
400 ./configure # (--help to see options)
401 make # (the make from gnu, gmake for *BSD)
403 make -n install # (to see where all the files will go)
404 make -s install # (to really install, -s to silence output)
406 If you have GNU make, you can have the first four steps automatically done for
411 in the freshly downloaded or unpacked source directory.
413 WARNING: If installing as root, the install will fail unless another user is
414 specified. configure accepts --with-user and --with-group options for setting
415 user and group ownership of the configuration files (which need to be writable
416 by the daemon). The specified user must already exist. Or if there is already a
417 privoxy user on the system, and no user was specified during configure, make
418 install then will use the privoxy user. When starting Privoxy, it should be run
419 as this same user that owns the configuration and log files.
421 Alternately, you can specify user and group on the make command line, but be
422 sure both already exist:
424 make -s install USER=privoxy GROUP=privoxy
426 If no group is specified, the install will assume a group exists with the same
427 name as the specified user.
429 The default installation path for make install is /usr/local. This may of
430 course be customized with the various ./configure path options. If you are
431 doing a root install to anywhere else besides /usr/local, be sure to set the
432 appropriate paths with the correct configure options (./configure --help).
434 If you do install to /usr/local, the install will use sysconfdir=$prefix/etc/
435 privoxy by default. All other destinations, and the direct usage of
436 --sysconfdir flag behave like normal, i.e. will not add the extra privoxy
437 directory. This is for a safer install, as there may already exist another
438 program that uses a file with the "config" name, and thus makes /usr/local/etc
441 If installing to /usr/local, the docs will go by default to $prefix/share/doc.
442 But if this directory doesn't exist, it will then try $prefix/doc and install
443 there before creating a new $prefix/share/doc just for Privoxy.
445 Again, if the installs goes to /usr/local, the localstatedir (ie: var/) will
446 default to /var instead of $prefix/var so the logs will go to /var/log/privoxy
447 /, and the pid file will be created in /var/run/privoxy.pid.
449 make install will attempt to set the correct values in config (main
450 configuration file). You may want to check this to make sure all values are
451 correct. If appropriate, an init script will be installed, but it is up to the
452 user to determine how and where to start Privoxy. The init script should be
453 checked for correct paths and values, if anything other than a default install
456 If install finds previous versions of any configuration files, these will not
457 be overwritten, and the new ones will be installed with a "new" extension. You
458 will then need to manually update the installed configuration files as needed.
459 All template files will be overwritten. If you have customized, local
460 templates, you should save these first. If a previous version of Privoxy is
461 already running, you will have to restart it manually.
463 For more detailed instructions on how to build Redhat and SuSE RPMs, Windows
464 self-extracting installers, building on platforms with special requirements
465 etc, please consult the developer manual.
467 -------------------------------------------------------------------------------
469 2.3. Keeping your Installation Up-to-Date
471 As user feedback comes in and development continues, we will make updated
472 versions of both the main actions file (as a separate package) and the software
473 itself (including the actions file) available for download.
475 If you wish to receive an email notification whenever we release updates of
476 Privoxy or the actions file, subscribe to our announce mailing list,
477 ijbswa-announce@lists.sourceforge.net.
479 In order not to loose your personal changes and adjustments when updating to
480 the latest default.action file we strongly recommend that you use user.action
481 for your customization of Privoxy. See the Chapter on actions files for
484 -------------------------------------------------------------------------------
488 There are very significant changes from earlier Junkbuster versions to the
489 current Privoxy. The number, names, syntax, and purposes of configuration files
490 have substantially changed. Junkbuster 2.0.x configuration files will not
491 migrate, Junkbuster 2.9.x and Privoxy configurations will need to be ported.
492 The functionalities of the old blockfile, cookiefile and imagelist are now
493 combined into the "actions files". default.action, is the main actions file.
494 Local exceptions should best be put into user.action.
496 A "filter file" (typically default.filter) is new as of Privoxy 2.9.x, and
497 provides some of the new sophistication (explained below). config is much the
500 If upgrading from a 2.0.x version, you will have to use the new config files,
501 and possibly adapt any personal rules from your older files. When porting
502 personal rules over from the old blockfile to the new actions files, please
503 note that even the pattern syntax has changed. If upgrading from 2.9.x
504 development versions, it is still recommended to use the new configuration
507 A quick list of things to be aware of before upgrading:
509 * The default listening port is now 8118 due to a conflict with another
512 * Some installers may remove earlier versions completely. Save any important
515 * Privoxy is controllable with a web browser at the special URL: http://
516 config.privoxy.org/ (Shortcut: http://p.p/). Many aspects of configuration
517 can be done here, including temporarily disabling Privoxy.
519 * The primary configuration files for cookie management, ad and banner
520 blocking, and many other aspects of Privoxy configuration are the actions
521 files. It is strongly recommended to become familiar with the new actions
522 concept below, before modifying these files. Locally defined rules should
525 * Some installers may not automatically start Privoxy after installation.
527 -------------------------------------------------------------------------------
529 4. Quickstart to Using Privoxy
531 * If upgrading, from versions before 2.9.16, please back up any configuration
532 files. See the Note to Upgraders Section.
534 * Install Privoxy. See the Installation Section below for platform specific
537 * Advanced users and those who want to offer Privoxy service to more than
538 just their local machine should check the main config file, especially the
539 security-relevant options. These are off by default.
541 * Start Privoxy, if the installation program has not done this already (may
542 vary according to platform). See the section Starting Privoxy.
544 * Set your browser to use Privoxy as HTTP and HTTPS (SSL) proxy by setting
545 the proxy configuration for address of 127.0.0.1 and port 8118. (Junkbuster
546 and earlier versions of Privoxy used port 8000.) See the section Starting
547 Privoxy below for more details on this.
549 * Flush your browser's disk and memory caches, to remove any cached ad
550 images. If using Privoxy to manage cookies, you should remove any currently
553 * A default installation should provide a reasonable starting point for most.
554 There will undoubtedly be occasions where you will want to adjust the
555 configuration, but that can be dealt with as the need arises. Little to no
556 initial configuration is required in most cases.
558 See the Configuration section for more configuration options, and how to
559 customize your installation.
561 * If you experience ads that slipped through, innocent images that are
562 blocked, or otherwise feel the need to fine-tune Privoxy's behaviour, take
563 a look at the actions files. As a quick start, you might find the richly
564 commented examples helpful. You can also view and edit the actions files
565 through the web-based user interface. The Appendix "Anatomy of an Action"
566 has hints how to debug actions that "misbehave".
568 * Please see the section Contacting the Developers on how to report bugs or
569 problems with websites or to get help.
571 * Now enjoy surfing with enhanced comfort and privacy!
573 -------------------------------------------------------------------------------
575 4.1. Quickstart to Ad Blocking
577 Ad blocking is but one of Privoxy's array of features. Many of these features
578 are for the technically minded advanced user. But, ad and banner blocking is
579 surely common ground for everybody.
581 This section will provide a quick summary of ad blocking so you can get up to
582 speed quickly without having to read the more extensive information provided
583 below, though this is highly recommended.
585 First a bit of a warning ... blocking ads is much like blocking SPAM: the more
586 aggressive you are about it, the more likely you are to block things that were
587 not intended. So there is a trade off here. If you want extreme ad free
588 browsing, be prepared to deal with more "problem" sites, and to spend more time
589 adjusting the configuration to solve these unintended consequences. In short,
590 there is not an easy way to eliminate all ads. Either take the easy way and
591 settle for most ads blocked with the default configuration, or jump in and
592 tweak it for your personal surfing habits and preferences.
594 Secondly, a brief explanation of Privoxy's "actions". "Actions" in this
595 context, are the directives we use to tell Privoxy to perform some task
596 relating to HTTP transactions (i.e. web browsing). We tell Privoxy to take some
597 "action". Each action has a unique name and function. While there are many
598 potential actions in Privoxy's arsenal, only a few are used for ad blocking.
599 Actions, and action configuration files, are explained in depth below.
601 Actions are specified in Privoxy's configuration, followed by one or more URLs
602 to which the action should apply. URLs can actually be URL type patterns that
603 use wildcards so they can apply potentially to a range of similar URLs. The
604 actions, together with the URL patterns are called a section.
606 When you connect to a website, the full URL will either match one or more of
607 the sections as defined in Privoxy's configuration, or not. If so, then Privoxy
608 will perform the respective actions. If not, then nothing special happens.
609 Furthermore, web pages may contain embedded, secondary URLs that your web
610 browser will use to load additional components of the page, as it parses the
611 original page's HTML content. An ad image for instance, is just an URL embedded
612 in the page somewhere. The image itself may be on the same server, or a server
613 somewhere else on the Internet. Complex web pages will have many such embedded
616 The actions we need to know about for ad blocking are: block, handle-as-image,
617 and set-image-blocker:
619 * block - this action stops any contact between your browser and any URL
620 patterns that match this action's configuration. It can be used for
621 blocking ads, but also anything that is determined to be unwanted. By
622 itself, it simply stops any communication with the remote server and sends
623 Privoxy's own built-in BLOCKED page instead to let you now what has
626 * handle-as-image - tells Privoxy to treat this URL as an image. Privoxy's
627 default configuration already does this for all common image types (e.g.
628 GIF), but there are many situations where this is not so easy to determine.
629 So we'll force it in these cases. This is particularly important for ad
630 blocking, since only if we know that it's an image of some kind, can we
631 replace it with an image of our choosing, instead of the Privoxy BLOCKED
632 page (which would only result in a "broken image" icon). There are some
633 limitations to this though. For instance, you can't just brute-force an
634 image substitution for an entire HTML page in most situations.
636 * set-image-blocker - tells Privoxy what to display in place of an ad image
637 that has hit a block rule. For this to come into play, the URL must match a
638 block action somewhere in the configuration, and, it must also match an
639 handle-as-image action.
641 The configuration options on what to display instead of the ad are:
643 pattern - a checkerboard pattern, so that an ad replacement is obvious.
646 blank - A very small empty GIF image is displayed. This is the so-called
647 "invisible" configuration option.
649 http://<URL> - A redirect to any image anywhere of the user's choosing
652 The quickest way to adjust any of these settings is with your browser through
653 the special Privoxy editor at http://config.privoxy.org/show-status (shortcut:
654 http://p.p/show-status). This is an internal page, and does not require
655 Internet access. Select the appropriate "actions" file, and click "Edit". It is
656 best to put personal or local preferences in user.action since this is not
657 meant to be overwritten during upgrades, and will over-ride the settings in
658 other files. Here you can insert new "actions", and URLs for ad blocking or
659 other purposes, and make other adjustments to the configuration. Privoxy will
660 detect these changes automatically.
662 A quick and simple step by step example:
664 * Right click on the ad image to be blocked, then select "Copy Link Location"
665 from the pop-up menu.
667 * Set your browser to http://config.privoxy.org/show-status
669 * Find user.action in the top section, and click on "Edit":
671 Figure 1. Actions Files in Use
675 * You should have a section with only block listed under "Actions:". If not,
676 click a "Insert new section below" button, and in the new section that just
677 appeared, click the Edit button right under the word "Actions:". This will
678 bring up a list of all actions. Find block near the top, and click in the
679 "Enabled" column, then "Submit" just below the list.
681 * Now, in the block actions section, click the "Add" button, and paste the
682 URL the browser got from "Copy Link Location". Remove the http:// at the
683 beginning of the URL. Then, click "Submit" (or "OK" if in a pop-up window).
685 * Now go back to the original page, and press SHIFT-Reload (or flush all
686 browser caches). The image should be gone now.
688 This is a very crude and simple example. There might be good reasons to use a
689 wildcard pattern match to include potentially similar images from the same
690 site. For a more extensive explanation of "patterns", and the entire actions
691 concept, see the Actions section.
693 For advanced users who want to hand edit their config files, you might want to
694 now go to the Actions Files Tutorial. The ideas explained therein also apply to
695 the web-based editor.
697 -------------------------------------------------------------------------------
701 Before launching Privoxy for the first time, you will want to configure your
702 browser(s) to use Privoxy as a HTTP and HTTPS proxy. The default is 127.0.0.1
703 (or localhost) for the proxy address, and port 8118 (earlier versions used port
704 8000). This is the one configuration step that must be done!
706 Please note that Privoxy can only proxy HTTP and HTTPS traffic. It will not
707 work with FTP or other protocols.
709 Figure 2. Proxy Configuration (Mozilla)
713 With Netscape (and Mozilla), this can be set under:
725 For Internet Explorer:
735 Then, check "Use Proxy" and fill in the appropriate info (Address: 127.0.0.1,
736 Port: 8118). Include HTTPS (SSL), if you want HTTPS proxy support too.
738 After doing this, flush your browser's disk and memory caches to force a
739 re-reading of all pages and to get rid of any ads that may be cached. You are
740 now ready to start enjoying the benefits of using Privoxy!
742 Privoxy is typically started by specifying the main configuration file to be
743 used on the command line. If no configuration file is specified on the command
744 line, Privoxy will look for a file named config in the current directory.
745 Except on Win32 where it will try config.txt.
747 -------------------------------------------------------------------------------
749 5.1. Red Hat and Conectiva
751 We use a script. Note that Red Hat does not start Privoxy upon booting per
752 default. It will use the file /etc/privoxy/config as its main configuration
755 # /etc/rc.d/init.d/privoxy start
757 -------------------------------------------------------------------------------
761 We use a script. Note that Debian starts Privoxy upon booting per default. It
762 will use the file /etc/privoxy/config as its main configuration file.
764 # /etc/init.d/privoxy start
766 -------------------------------------------------------------------------------
770 We use a script. It will use the file /etc/privoxy/config as its main
771 configuration file. Note that SuSE starts Privoxy upon booting your PC.
775 -------------------------------------------------------------------------------
779 Click on the Privoxy Icon to start Privoxy. If no configuration file is
780 specified on the command line, Privoxy will look for a file named config.txt.
781 Note that Windows will automatically start Privoxy upon booting you PC.
783 -------------------------------------------------------------------------------
785 5.5. Solaris, NetBSD, FreeBSD, HP-UX and others
787 Example Unix startup command:
789 # /usr/sbin/privoxy /etc/privoxy/config
791 -------------------------------------------------------------------------------
795 During installation, Privoxy is configured to start automatically when the
796 system restarts. You can start it manually by double-clicking on the Privoxy
797 icon in the Privoxy folder.
799 -------------------------------------------------------------------------------
803 During installation, Privoxy is configured to start automatically when the
804 system restarts. To start Privoxy by hand, double-click on the
805 StartPrivoxy.command icon in the /Library/Privoxy folder. Or, type this command
808 /Library/Privoxy/StartPrivoxy.command
811 You will be prompted for the administrator password.
813 -------------------------------------------------------------------------------
817 Start Privoxy (with RUN <>NIL:) in your startnet script (AmiTCP), in s:
818 user-startup (RoadShow), as startup program in your startup script (Genesis),
819 or as startup action (Miami and MiamiDx). Privoxy will automatically quit when
820 you quit your TCP/IP stack (just ignore the harmless warning your TCP/IP stack
821 may display that Privoxy is still running).
823 -------------------------------------------------------------------------------
827 A script is again used. It will use the file /etc/privoxy/config as its main
830 /etc/init.d/privoxy start
833 Note that Privoxy is not automatically started at boot time by default. You can
834 change this with the rc-update command.
836 rc-update add privoxy default
839 -------------------------------------------------------------------------------
841 5.10. Command Line Options
843 Privoxy may be invoked with the following command-line options:
847 Print version info and exit. Unix only.
851 Print short usage info and exit. Unix only.
855 Don't become a daemon, i.e. don't fork and become process group leader, and
856 don't detach from controlling tty. Unix only.
860 On startup, write the process ID to FILE. Delete the FILE on exit. Failure
861 to create or delete the FILE is non-fatal. If no FILE option is given, no
862 PID file will be used. Unix only.
864 * --user USER[.GROUP]
866 After (optionally) writing the PID file, assume the user ID of USER, and if
867 included the GID of GROUP. Exit if the privileges are not sufficient to do
872 Before changing to the user ID given in the --user option, chroot to that
873 user's home directory, i.e. make the kernel pretend to the Privoxy process
874 that the directory tree starts there. If set up carefully, this can limit
875 the impact of possible vulnerabilities in Privoxy to the files contained in
876 that hierarchy. Unix only.
880 If no configfile is included on the command line, Privoxy will look for a
881 file named "config" in the current directory (except on Win32 where it will
882 look for "config.txt" instead). Specify full path to avoid confusion. If no
883 config file is found, Privoxy will fail to start.
885 -------------------------------------------------------------------------------
887 6. Privoxy Configuration
889 All Privoxy configuration is stored in text files. These files can be edited
890 with a text editor. Many important aspects of Privoxy can also be controlled
891 easily with a web browser.
893 -------------------------------------------------------------------------------
895 6.1. Controlling Privoxy with Your Web Browser
897 Privoxy's user interface can be reached through the special URL http://
898 config.privoxy.org/ (shortcut: http://p.p/), which is a built-in page and works
899 without Internet access. You will see the following section:
902 ? View & change the current configuration
903 ? View the source code version numbers
904 ? View the request headers.
905 ? Look up which actions apply to a URL and why
906 ? Toggle Privoxy on or off
910 This should be self-explanatory. Note the first item leads to an editor for the
911 actions files, which is where the ad, banner, cookie, and URL blocking magic is
912 configured as well as other advanced features of Privoxy. This is an easy way
913 to adjust various aspects of Privoxy configuration. The actions file, and other
914 configuration files, are explained in detail below.
916 "Toggle Privoxy On or Off" is handy for sites that might have problems with
917 your current actions and filters. You can in fact use it as a test to see
918 whether it is Privoxy causing the problem or not. Privoxy continues to run as a
919 proxy in this case, but all manipulation is disabled, i.e. Privoxy acts like a
920 normal forwarding proxy. There is even a toggle Bookmarklet offered, so that
921 you can toggle Privoxy with one click from your browser.
923 -------------------------------------------------------------------------------
925 6.2. Configuration Files Overview
927 For Unix, *BSD and Linux, all configuration files are located in /etc/privoxy/
928 by default. For MS Windows, OS/2, and AmigaOS these are all in the same
929 directory as the Privoxy executable.
931 The installed defaults provide a reasonable starting point, though some
932 settings may be aggressive by some standards. For the time being, the principle
933 configuration files are:
935 * The main configuration file is named config on Linux, Unix, BSD, OS/2, and
936 AmigaOS and config.txt on Windows. This is a required file.
938 * default.action (the main actions file) is used to define which "actions"
939 relating to banner-blocking, images, pop-ups, content modification, cookie
940 handling etc should be applied by default. It also defines many exceptions
941 (both positive and negative) from this default set of actions that enable
942 Privoxy to selectively eliminate the junk, and only the junk, on as many
943 websites as possible.
945 Multiple actions files may be defined in config. These are processed in the
946 order they are defined. Local customizations and locally preferred
947 exceptions to the default policies as defined in default.action (which you
948 will most probably want to define sooner or later) are probably best
949 applied in user.action, where you can preserve them across upgrades.
950 standard.action is for Privoxy's internal use.
952 There is also a web based editor that can be accessed from http://
953 config.privoxy.org/show-status (Shortcut: http://p.p/show-status) for the
954 various actions files.
956 * default.filter (the filter file) can be used to re-write the raw page
957 content, including viewable text as well as embedded HTML and JavaScript,
958 and whatever else lurks on any given web page. The filtering jobs are only
959 pre-defined here; whether to apply them or not is up to the actions files.
961 All files use the "#" character to denote a comment (the rest of the line will
962 be ignored) and understand line continuation through placing a backslash ("\")
963 as the very last character in a line. If the # is preceded by a backslash, it
964 looses its special function. Placing a # in front of an otherwise valid
965 configuration line to prevent it from being interpreted is called "commenting
968 The actions files and default.filter can use Perl style regular expressions for
971 After making any changes, there is no need to restart Privoxy in order for the
972 changes to take effect. Privoxy detects such changes automatically. Note,
973 however, that it may take one or two additional requests for the change to take
974 effect. When changing the listening address of Privoxy, these "wake up"
975 requests must obviously be sent to the old listening address.
977 -------------------------------------------------------------------------------
979 7. The Main Configuration File
981 Again, the main configuration file is named config on Linux/Unix/BSD and OS/2,
982 and config.txt on Windows. Configuration lines consist of an initial keyword
983 followed by a list of values, all separated by whitespace (any number of spaces
984 or tabs). For example:
988 Assigns the value /etc/privoxy to the option confdir and thus indicates that
989 the configuration directory is named "/etc/privoxy/".
991 All options in the config file except for confdir and logdir are optional.
992 Watch out in the below description for what happens if you leave them unset.
994 The main config file controls all aspects of Privoxy's operation that are not
995 location dependent (i.e. they apply universally, no matter where you may be
998 -------------------------------------------------------------------------------
1000 7.1. Configuration and Log File Locations
1002 Privoxy can (and normally does) use a number of other files for additional
1003 configuration, help and logging. This section of the configuration file tells
1004 Privoxy where to find those other files.
1006 The user running Privoxy, must have read permission for all configuration
1007 files, and write permission to any files that would be modified, such as log
1008 files and actions files.
1010 -------------------------------------------------------------------------------
1016 The directory where the other configuration files are located
1024 /etc/privoxy (Unix) or Privoxy installation dir (Windows)
1032 No trailing "/", please
1034 When development goes modular and multi-user, the blocker, filter, and
1035 per-user config will be stored in subdirectories of "confdir". For now, the
1036 configuration directory structure is flat, except for confdir/templates,
1037 where the HTML templates for CGI output reside (e.g. Privoxy's 404 error
1040 -------------------------------------------------------------------------------
1046 The directory where all logging takes place (i.e. where logfile and jarfile
1055 /var/log/privoxy (Unix) or Privoxy installation dir (Windows)
1063 No trailing "/", please
1065 -------------------------------------------------------------------------------
1071 The actions file(s) to use
1075 File name, relative to confdir, without the .action suffix
1079 standard # Internal purposes, no editing recommended
1081 default # Main actions file
1083 user # User customizations
1087 No actions are taken at all. Simple neutral proxying.
1091 Multiple actionsfile lines are permitted, and are in fact recommended!
1093 The default values include standard.action, which is used for internal
1094 purposes and should be loaded, default.action, which is the "main" actions
1095 file maintained by the developers, and user.action, where you can make your
1098 Actions files are where all the per site and per URL configuration is done
1099 for ad blocking, cookie management, privacy considerations, etc. There is
1100 no point in using Privoxy without at least one actions file.
1102 -------------------------------------------------------------------------------
1108 The filter file to use
1112 File name, relative to confdir
1116 default.filter (Unix) or default.filter.txt (Windows)
1120 No textual content filtering takes place, i.e. all +filter{name} actions in
1121 the actions files are turned neutral.
1125 The filter file contains content modification rules that use regular
1126 expressions. These rules permit powerful changes on the content of Web
1127 pages, e.g., you could disable your favorite JavaScript annoyances,
1128 re-write the actual displayed text, or just have some fun replacing
1129 "Microsoft" with "MicroSuck" wherever it appears on a Web page.
1131 The +filter{name} actions rely on the relevant filter (name) to be defined
1134 A pre-defined filter file called default.filter that contains a bunch of
1135 handy filters for common problems is included in the distribution. See the
1136 section on the filter action for a list.
1138 -------------------------------------------------------------------------------
1148 File name, relative to logdir
1152 logfile (Unix) or privoxy.log (Windows)
1156 No log file is used, all log messages go to the console (STDERR).
1160 The logfile is where all logging and error messages are written. The level
1161 of detail and number of messages are set with the debug option (see below).
1162 The logfile can be useful for tracking down a problem with Privoxy (e.g.,
1163 it's not blocking an ad you think it should block) but in most cases you
1164 probably will never look at it.
1166 Your logfile will grow indefinitely, and you will probably want to
1167 periodically remove it. On Unix systems, you can do this with a cron job
1168 (see "man cron"). For Red Hat, a logrotate script has been included.
1170 On SuSE Linux systems, you can place a line like "/var/log/privoxy.* +1024k
1171 644 nobody.nogroup" in /etc/logfiles, with the effect that cron.daily will
1172 automatically archive, gzip, and empty the log, when it exceeds 1M size.
1174 Any log files must be writable by whatever user Privoxy is being run as
1175 (default on UNIX, user id is "privoxy").
1177 -------------------------------------------------------------------------------
1183 The file to store intercepted cookies in
1187 File name, relative to logdir
1191 jarfile (Unix) or privoxy.jar (Windows)
1195 Intercepted cookies are not stored at all.
1199 The jarfile may grow to ridiculous sizes over time.
1201 -------------------------------------------------------------------------------
1207 The trust file to use
1211 File name, relative to confdir
1215 Unset (commented out). When activated: trust (Unix) or trust.txt (Windows)
1219 The entire trust mechanism is turned off.
1223 The trust mechanism is an experimental feature for building white-lists and
1224 should be used with care. It is NOT recommended for the casual user.
1226 If you specify a trust file, Privoxy will only allow access to sites that
1227 are specified in the trustfile. Sites can be listed in one of two ways:
1229 Prepending a ~ character limits access to this site only (and any sub-paths
1230 within this site), e.g. ~www.example.com.
1232 Or, you can designate sites as trusted referrers, by prepending the name
1233 with a + character. The effect is that access to untrusted sites will be
1234 granted -- but only if a link from this trusted referrer was used. The link
1235 target will then be added to the "trustfile" so that future, direct
1236 accesses will be granted. Sites added via this mechanism do not become
1237 trusted referrers themselves (i.e. they are added with a ~ designation).
1239 If you use the + operator in the trust file, it may grow considerably over
1242 It is recommended that Privoxy be compiled with the --disable-force,
1243 --disable-toggle and --disable-editor options, if this feature is to be
1246 Possible applications include limiting Internet access for children.
1248 -------------------------------------------------------------------------------
1250 7.2. Local Set-up Documentation
1252 If you intend to operate Privoxy for more users than just yourself, it might be
1253 a good idea to let them know how to reach you, what you block and why you do
1254 that, your policies, etc.
1256 -------------------------------------------------------------------------------
1262 Location of the Privoxy User Manual.
1266 A fully qualified URI
1274 http://www.privoxy.org/version/user-manual/ will be used, where version is
1275 the Privoxy version.
1279 The User Manual URI is used for help links from some of the internal CGI
1280 pages. The manual itself is normally packaged with the binary
1281 distributions, so you probably want to set this to a locally installed
1282 copy. For multi-user setups, you could provide a copy on a local webserver
1283 for all your users and use the corresponding URL here.
1287 Unix, in local filesystem:
1289 user-manual file:///usr/share/doc/privoxy-3.0.1/user-manual/
1291 Windows, in local filesystem, must use forward slash notation:
1293 user-manual file:/c:/some-dir/privoxy-3.0.1/user-manual/
1295 Windows, UNC notation (with forward slashes):
1297 user-manual file://///some-server/some-path/privoxy-3.0.1/user-manual/
1299 Any platform, on local webserver (called "local-webserver"):
1301 user-manual http://local-webserver/privoxy-user-manual/
1303 +-----------------------------------------------------------------+
1305 |-----------------------------------------------------------------|
1306 |If set, this option should be the first option in the config |
1307 |file, because it is used while the config file is being read. |
1308 +-----------------------------------------------------------------+
1310 -------------------------------------------------------------------------------
1312 7.2.2. trust-info-url
1316 A URL to be displayed in the error page that users will see if access to an
1317 untrusted page is denied.
1325 Two example URL are provided
1329 No links are displayed on the "untrusted" error page.
1333 The value of this option only matters if the experimental trust mechanism
1334 has been activated. (See trustfile above.)
1336 If you use the trust mechanism, it is a good idea to write up some on-line
1337 documentation about your trust policy and to specify the URL(s) here. Use
1338 multiple times for multiple URLs.
1340 The URL(s) should be added to the trustfile as well, so users don't end up
1341 locked out from the information on why they were locked out in the first
1344 -------------------------------------------------------------------------------
1346 7.2.3. admin-address
1350 An email address to reach the proxy administrator.
1362 No email address is displayed on error pages and the CGI user interface.
1366 If both admin-address and proxy-info-url are unset, the whole "Local
1367 Privoxy Support" box on all generated pages will not be shown.
1369 -------------------------------------------------------------------------------
1371 7.2.4. proxy-info-url
1375 A URL to documentation about the local Privoxy setup, configuration or
1388 No link to local documentation is displayed on error pages and the CGI user
1393 If both admin-address and proxy-info-url are unset, the whole "Local
1394 Privoxy Support" box on all generated pages will not be shown.
1396 This URL shouldn't be blocked ;-)
1398 -------------------------------------------------------------------------------
1402 These options are mainly useful when tracing a problem. Note that you might
1403 also want to invoke Privoxy with the --no-daemon command line option when
1406 -------------------------------------------------------------------------------
1412 Key values that determine what information gets logged to the logfile.
1420 12289 (i.e.: URLs plus informational and warning messages)
1424 Nothing gets logged.
1428 The available debug levels are:
1430 debug 1 # show each GET/POST/CONNECT request
1431 debug 2 # show each connection status
1432 debug 4 # show I/O status
1433 debug 8 # show header parsing
1434 debug 16 # log all data into the logfile
1435 debug 32 # debug force feature
1436 debug 64 # debug regular expression filter
1437 debug 128 # debug fast redirects
1438 debug 256 # debug GIF de-animation
1439 debug 512 # Common Log Format
1440 debug 1024 # debug kill pop-ups
1441 debug 2048 # CGI user interface
1442 debug 4096 # Startup banner and warnings.
1443 debug 8192 # Non-fatal errors
1445 To select multiple debug levels, you can either add them or use multiple
1448 A debug level of 1 is informative because it will show you each request as
1449 it happens. 1, 4096 and 8192 are highly recommended so that you will notice
1450 when things go wrong. The other levels are probably only of interest if you
1451 are hunting down a specific problem. They can produce a hell of an output
1454 The reporting of fatal errors (i.e. ones which crash Privoxy) is always on
1455 and cannot be disabled.
1457 If you want to use CLF (Common Log Format), you should set "debug 512" ONLY
1458 and not enable anything else.
1460 -------------------------------------------------------------------------------
1462 7.3.2. single-threaded
1466 Whether to run only one server thread
1478 Multi-threaded (or, where unavailable: forked) operation, i.e. the ability
1479 to serve multiple requests simultaneously.
1483 This option is only there for debug purposes and you should never need to
1484 use it. It will drastically reduce performance.
1486 -------------------------------------------------------------------------------
1488 7.4. Access Control and Security
1490 This section of the config file controls the security-relevant aspects of
1491 Privoxy's configuration.
1493 -------------------------------------------------------------------------------
1495 7.4.1. listen-address
1499 The IP address and TCP port on which Privoxy will listen for client
1512 Bind to 127.0.0.1 (localhost), port 8118. This is suitable and recommended
1513 for home users who run Privoxy on the same machine as their browser.
1517 You will need to configure your browser(s) to this proxy address and port.
1519 If you already have another service running on port 8118, or if you want to
1520 serve requests from other machines (e.g. on your local network) as well,
1521 you will need to override the default.
1523 If you leave out the IP address, Privoxy will bind to all interfaces
1524 (addresses) on your machine and may become reachable from the Internet. In
1525 that case, consider using access control lists (ACL's, see below), and/or a
1528 If you open Privoxy to untrusted users, you will also want to turn off the
1529 enable-edit-actions and enable-remote-toggle options!
1533 Suppose you are running Privoxy on a machine which has the address
1534 192.168.0.1 on your local private network (192.168.0.0) and has another
1535 outside connection with a different address. You want it to serve requests
1538 listen-address 192.168.0.1:8118
1540 -------------------------------------------------------------------------------
1546 Initial state of "toggle" status
1558 Act as if toggled on
1562 If set to 0, Privoxy will start in "toggled off" mode, i.e. behave like a
1563 normal, content-neutral proxy where all ad blocking, filtering, etc are
1564 disabled. See enable-remote-toggle below. This is not really useful
1565 anymore, since toggling is much easier via the web interface than via
1566 editing the conf file.
1568 The windows version will only display the toggle icon in the system tray if
1569 this option is present.
1571 -------------------------------------------------------------------------------
1573 7.4.3. enable-remote-toggle
1577 Whether or not the web-based toggle feature may be used
1589 The web-based toggle feature is disabled.
1593 When toggled off, Privoxy acts like a normal, content-neutral proxy, i.e.
1594 it acts as if none of the actions applied to any URL.
1596 For the time being, access to the toggle feature can not be controlled
1597 separately by "ACLs" or HTTP authentication, so that everybody who can
1598 access Privoxy (see "ACLs" and listen-address above) can toggle it for all
1599 users. So this option is not recommended for multi-user environments with
1602 Note that you must have compiled Privoxy with support for this feature,
1603 otherwise this option has no effect.
1605 -------------------------------------------------------------------------------
1607 7.4.4. enable-edit-actions
1611 Whether or not the web-based actions file editor may be used
1623 The web-based actions file editor is disabled.
1627 For the time being, access to the editor can not be controlled separately
1628 by "ACLs" or HTTP authentication, so that everybody who can access Privoxy
1629 (see "ACLs" and listen-address above) can modify its configuration for all
1630 users. So this option is not recommended for multi-user environments with
1633 Note that you must have compiled Privoxy with support for this feature,
1634 otherwise this option has no effect.
1636 -------------------------------------------------------------------------------
1638 7.4.5. ACLs: permit-access and deny-access
1642 Who can access what.
1646 src_addr[/src_masklen] [dst_addr[/dst_masklen]]
1648 Where src_addr and dst_addr are IP addresses in dotted decimal notation or
1649 valid DNS names, and src_masklen and dst_masklen are subnet masks in CIDR
1650 notation, i.e. integer values from 2 to 30 representing the length (in
1651 bits) of the network address. The masks and the whole destination part are
1660 Don't restrict access further than implied by listen-address
1664 Access controls are included at the request of ISPs and systems
1665 administrators, and are not usually needed by individual users. For a
1666 typical home user, it will normally suffice to ensure that Privoxy only
1667 listens on the localhost (127.0.0.1) or internal (home) network address by
1668 means of the listen-address option.
1670 Please see the warnings in the FAQ that this proxy is not intended to be a
1671 substitute for a firewall or to encourage anyone to defer addressing basic
1672 security weaknesses.
1674 Multiple ACL lines are OK. If any ACLs are specified, then the Privoxy
1675 talks only to IP addresses that match at least one permit-access line and
1676 don't match any subsequent deny-access line. In other words, the last match
1677 wins, with the default being deny-access.
1679 If Privoxy is using a forwarder (see forward below) for a particular
1680 destination URL, the dst_addr that is examined is the address of the
1681 forwarder and NOT the address of the ultimate target. This is necessary
1682 because it may be impossible for the local Privoxy to determine the IP
1683 address of the ultimate target (that's often what gateways are used for).
1685 You should prefer using IP addresses over DNS names, because the address
1686 lookups take time. All DNS names must resolve! You can not use domain
1687 patterns like "*.org" or partial domain names. If a DNS name resolves to
1688 multiple IP addresses, only the first one is used.
1690 Denying access to particular sites by ACL may have undesired side effects
1691 if the site in question is hosted on a machine which also hosts other
1696 Explicitly define the default behavior if no ACL and listen-address are
1697 set: "localhost" is OK. The absence of a dst_addr implies that all
1698 destination addresses are OK:
1700 permit-access localhost
1702 Allow any host on the same class C subnet as www.privoxy.org access to
1703 nothing but www.example.com:
1705 permit-access www.privoxy.org/24 www.example.com/32
1707 Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere,
1708 with the exception that 192.168.45.73 may not access
1709 www.dirty-stuff.example.com:
1711 permit-access 192.168.45.64/26
1712 deny-access 192.168.45.73 www.dirty-stuff.example.com
1714 -------------------------------------------------------------------------------
1720 Maximum size of the buffer for content filtering.
1732 Use a 4MB (4096 KB) limit.
1736 For content filtering, i.e. the +filter and +deanimate-gif actions, it is
1737 necessary that Privoxy buffers the entire document body. This can be
1738 potentially dangerous, since a server could just keep sending data
1739 indefinitely and wait for your RAM to exhaust -- with nasty consequences.
1742 When a document buffer size reaches the buffer-limit, it is flushed to the
1743 client unfiltered and no further attempt to filter the rest of the document
1744 is made. Remember that there may be multiple threads running, which might
1745 require up to buffer-limit Kbytes each, unless you have enabled
1746 "single-threaded" above.
1748 -------------------------------------------------------------------------------
1752 This feature allows routing of HTTP requests through a chain of multiple
1753 proxies. It can be used to better protect privacy and confidentiality when
1754 accessing specific domains by routing requests to those domains through an
1755 anonymous public proxy (see e.g. http://www.multiproxy.org/anon_list.htm) Or to
1756 use a caching proxy to speed up browsing. Or chaining to a parent proxy may be
1757 necessary because the machine that Privoxy runs on has no direct Internet
1760 Also specified here are SOCKS proxies. Privoxy supports the SOCKS 4 and SOCKS
1763 -------------------------------------------------------------------------------
1769 To which parent HTTP proxy specific requests should be routed.
1773 target_pattern http_parent[:port]
1775 where target_pattern is a URL pattern that specifies to which requests
1776 (i.e. URLs) this forward rule shall apply. Use / to denote "all URLs".
1777 http_parent[:port] is the DNS name or IP address of the parent HTTP proxy
1778 through which the requests should be forwarded, optionally followed by its
1779 listening port (default: 8080). Use a single dot (.) to denote "no
1788 Don't use parent HTTP proxies.
1792 If http_parent is ".", then requests are not forwarded to another HTTP
1793 proxy but are made directly to the web servers.
1795 Multiple lines are OK, they are checked in sequence, and the last match
1800 Everything goes to an example anonymizing proxy, except SSL on port 443
1801 (which it doesn't handle):
1803 forward / anon-proxy.example.org:8080
1806 Everything goes to our example ISP's caching proxy, except for requests to
1809 forward / caching-proxy.example-isp.net:8000
1810 forward .example-isp.net .
1812 -------------------------------------------------------------------------------
1814 7.5.2. forward-socks4 and forward-socks4a
1818 Through which SOCKS proxy (and to which parent HTTP proxy) specific
1819 requests should be routed.
1823 target_pattern socks_proxy[:port] http_parent[:port]
1825 where target_pattern is a URL pattern that specifies to which requests
1826 (i.e. URLs) this forward rule shall apply. Use / to denote "all URLs".
1827 http_parent and socks_proxy are IP addresses in dotted decimal notation or
1828 valid DNS names (http_parent may be "." to denote "no HTTP forwarding"),
1829 and the optional port parameters are TCP ports, i.e. integer values from 1
1838 Don't use SOCKS proxies.
1842 Multiple lines are OK, they are checked in sequence, and the last match
1845 The difference between forward-socks4 and forward-socks4a is that in the
1846 SOCKS 4A protocol, the DNS resolution of the target hostname happens on the
1847 SOCKS server, while in SOCKS 4 it happens locally.
1849 If http_parent is ".", then requests are not forwarded to another HTTP
1850 proxy but are made (HTTP-wise) directly to the web servers, albeit through
1855 From the company example.com, direct connections are made to all "internal"
1856 domains, but everything outbound goes through their ISP's proxy by way of
1857 example.com's corporate SOCKS 4A gateway to the Internet.
1859 forward-socks4a / socks-gw.example.com:1080 www-cache.example-isp.net:8080
1860 forward .example.com .
1862 A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent
1865 forward-socks4 / socks-gw.example.com:1080 .
1867 -------------------------------------------------------------------------------
1869 7.5.3. Advanced Forwarding Examples
1871 If you have links to multiple ISPs that provide various special content only to
1872 their subscribers, you can configure multiple Privoxies which have connections
1873 to the respective ISPs to act as forwarders to each other, so that your users
1874 can see the internal content of all ISPs.
1876 Assume that host-a has a PPP connection to isp-a.net. And host-b has a PPP
1877 connection to isp-b.net. Both run Privoxy. Their forwarding configuration can
1883 forward .isp-b.net host-b:8118
1888 forward .isp-a.net host-a:8118
1890 Now, your users can set their browser's proxy to use either host-a or host-b
1891 and be able to browse the internal content of both isp-a and isp-b.
1893 If you intend to chain Privoxy and squid locally, then chain as browser ->
1894 squid -> privoxy is the recommended way.
1896 Assuming that Privoxy and squid run on the same box, your squid configuration
1897 could then look like this:
1899 # Define Privoxy as parent proxy (without ICP)
1900 cache_peer 127.0.0.1 parent 8118 7 no-query
1902 # Define ACL for protocol FTP
1905 # Do not forward FTP requests to Privoxy
1906 always_direct allow ftp
1908 # Forward all the rest to Privoxy
1909 never_direct allow all
1911 You would then need to change your browser's proxy settings to squid's address
1912 and port. Squid normally uses port 3128. If unsure consult http_port in
1915 You could just as well decide to only forward requests for Windows executables
1916 through a virus-scanning parent proxy, say, on antivir.example.com, port 8010:
1919 forward /.*\.(exe|com|dll|zip)$ antivir.example.com:8010
1921 -------------------------------------------------------------------------------
1923 7.6. Windows GUI Options
1925 Privoxy has a number of options specific to the Windows GUI interface:
1927 If "activity-animation" is set to 1, the Privoxy icon will animate when
1928 "Privoxy" is active. To turn off, set to 0.
1930 activity-animation 1
1933 If "log-messages" is set to 1, Privoxy will log messages to the console window:
1938 If "log-buffer-size" is set to 1, the size of the log buffer, i.e. the amount
1939 of memory used for the log messages displayed in the console window, will be
1940 limited to "log-max-lines" (see below).
1942 Warning: Setting this to 0 will result in the buffer to grow infinitely and eat
1948 log-max-lines is the maximum number of lines held in the log buffer. See above.
1953 If "log-highlight-messages" is set to 1, Privoxy will highlight portions of the
1954 log messages with a bold-faced font:
1956 log-highlight-messages 1
1959 The font used in the console window:
1961 log-font-name Comic Sans MS
1964 Font size used in the console window:
1969 "show-on-task-bar" controls whether or not Privoxy will appear as a button on
1970 the Task bar when minimized:
1975 If "close-button-minimizes" is set to 1, the Windows close button will minimize
1976 Privoxy instead of closing the program (close with the exit option on the File
1979 close-button-minimizes 1
1982 The "hide-console" option is specific to the MS-Win console version of Privoxy.
1983 If this option is used, Privoxy will disconnect from and hide the command
1989 -------------------------------------------------------------------------------
1993 The actions files are used to define what actions Privoxy takes for which URLs,
1994 and thus determine how ad images, cookies and various other aspects of HTTP
1995 content and transactions are handled, and on which sites (or even parts
1996 thereof). There are three such files included with Privoxy with differing
1999 * default.action - is the primary action file that sets the initial values
2000 for all actions. It is intended to provide a base level of functionality
2001 for Privoxy's array of features. So it is a set of broad rules that should
2002 work reasonably well for users everywhere. This is the file that the
2003 developers are keeping updated, and making available to users.
2005 * user.action - is intended to be for local site preferences and exceptions.
2006 As an example, if your ISP or your bank has specific requirements, and need
2007 special handling, this kind of thing should go here. This file will not be
2010 * standard.action - is used by the web based editor, to set various
2011 pre-defined sets of rules for the default actions section in
2012 default.action. These have increasing levels of aggressiveness and have no
2013 influence on your browsing unless you select them explicitly in the editor.
2014 It is not recommend to edit this file.
2016 The default profiles, and their associated actions, as pre-defined in
2017 standard.action are:
2019 Table 1. Default Configurations
2021 +-------------------------------------------------------------------------+
2022 |Feature |Cautious |Medium |Adventuresome |
2023 |------------------+-----------------+-----------------+------------------|
2024 |Ad-blocking by URL|yes |yes |yes |
2025 |------------------+-----------------+-----------------+------------------|
2026 |Ad-filtering by |yes |yes |yes |
2028 |------------------+-----------------+-----------------+------------------|
2029 |GIF de-animation |no |yes |yes |
2030 |------------------+-----------------+-----------------+------------------|
2031 |Referer forging |no |yes |yes |
2032 |------------------+-----------------+-----------------+------------------|
2033 |Cookie handling |none |session-only |kill |
2034 |------------------+-----------------+-----------------+------------------|
2035 |Pop-up killing |unsolicited |unsolicited |all |
2036 |------------------+-----------------+-----------------+------------------|
2037 |Fast redirects |no |no |yes |
2038 |------------------+-----------------+-----------------+------------------|
2039 |HTML taming |yes |yes |yes |
2040 |------------------+-----------------+-----------------+------------------|
2041 |JavaScript taming |yes |yes |yes |
2042 |------------------+-----------------+-----------------+------------------|
2043 |Web-bug killing |yes |yes |yes |
2044 |------------------+-----------------+-----------------+------------------|
2045 |Fun text |no |no |yes |
2046 |replacements | | | |
2047 |------------------+-----------------+-----------------+------------------|
2048 |Image tag |no |no |yes |
2050 |------------------+-----------------+-----------------+------------------|
2051 |Ad-filtering by |no |no |yes |
2053 |------------------+-----------------+-----------------+------------------|
2054 |Demoronizer |no |yes |yes |
2055 +-------------------------------------------------------------------------+
2057 The list of actions files to be used are defined in the main configuration
2058 file, and are processed in the order they are defined (e.g. default.action is
2059 typically process before user.action). The content of these can all be viewed
2060 and edited from http://config.privoxy.org/show-status.
2062 An actions file typically has multiple sections. If you want to use "aliases"
2063 in an actions file, you have to place the (optional) alias section at the top
2064 of that file. Then comes the default set of rules which will apply universally
2065 to all sites and pages (be very careful with using such a universal set in
2066 user.action or any other actions file after default.action, because it will
2067 override the result from consulting any previous file). And then below that,
2068 exceptions to the defined universal policies. You can regard user.action as an
2069 appendix to default.action, with the advantage that is a separate file, which
2070 makes preserving your personal settings across Privoxy upgrades easier.
2072 Actions can be used to block anything you want, including ads, banners, or just
2073 some obnoxious URL that you would rather not see. Cookies can be accepted or
2074 rejected, or accepted only during the current browser session (i.e. not written
2075 to disk), content can be modified, JavaScripts tamed, user-tracking fooled, and
2076 much more. See below for a complete list of actions.
2078 -------------------------------------------------------------------------------
2080 8.1. Finding the Right Mix
2082 Note that some actions, like cookie suppression or script disabling, may render
2083 some sites unusable that rely on these techniques to work properly. Finding the
2084 right mix of actions is not always easy and certainly a matter of personal
2085 taste. In general, it can be said that the more "aggressive" your default
2086 settings (in the top section of the actions file) are, the more exceptions for
2087 "trusted" sites you will have to make later. If, for example, you want to
2088 crunch all cookies per default, you'll have to make exceptions from that rule
2089 for sites that you regularly use and that require cookies for actually useful
2090 puposes, like maybe your bank, favorite shop, or newspaper.
2092 We have tried to provide you with reasonable rules to start from in the
2093 distribution actions files. But there is no general rule of thumb on these
2094 things. There just are too many variables, and sites are constantly changing.
2095 Sooner or later you will want to change the rules (and read this chapter again
2098 -------------------------------------------------------------------------------
2102 The easiest way to edit the actions files is with a browser by using our
2103 browser-based editor, which can be reached from http://config.privoxy.org/
2104 show-status. The editor allows both fine-grained control over every single
2105 feature on a per-URL basis, and easy choosing from wholesale sets of defaults
2106 like "Cautious", "Medium" or "Adventuresome". Warning: the "Adventuresome"
2107 setting is not only more aggressive, but includes settings that are fun and
2108 subversive, and which some may find of dubious merit!
2110 If you prefer plain text editing to GUIs, you can of course also directly edit
2111 the the actions files. Look at default.action which is richly commented.
2113 -------------------------------------------------------------------------------
2115 8.3. How Actions are Applied to URLs
2117 Actions files are divided into sections. There are special sections, like the "
2118 alias" sections which will be discussed later. For now let's concentrate on
2119 regular sections: They have a heading line (often split up to multiple lines
2120 for readability) which consist of a list of actions, separated by whitespace
2121 and enclosed in curly braces. Below that, there is a list of URL patterns, each
2124 To determine which actions apply to a request, the URL of the request is
2125 compared to all patterns in each action file file. Every time it matches, the
2126 list of applicable actions for the URL is incrementally updated, using the
2127 heading of the section in which the pattern is located. If multiple matches for
2128 the same URL set the same action differently, the last match wins. If not, the
2129 effects are aggregated. E.g. a URL might match a regular section with a heading
2130 line of { +handle-as-image }, then later another one with just { +block },
2131 resulting in both actions to apply.
2133 You can trace this process for any given URL by visiting http://
2134 config.privoxy.org/show-url-info.
2136 More detail on this is provided in the Appendix, Anatomy of an Action.
2138 -------------------------------------------------------------------------------
2142 As mentioned, Privoxy uses "patterns" to determine what actions might apply to
2143 which sites and pages your browser attempts to access. These "patterns" use
2144 wild card type pattern matching to achieve a high degree of flexibility. This
2145 allows one expression to be expanded and potentially match against many similar
2148 Generally, a Privoxy pattern has the form <domain>/<path>, where both the
2149 <domain> and <path> are optional. (This is why the special / pattern matches
2150 all URLs). Note that the protocol portion of the URL pattern (e.g. http://)
2151 should not be included in the pattern. This is assumed already!
2155 is a domain-only pattern and will match any request to www.example.com,
2156 regardless of which document on that server is requested.
2160 means exactly the same. For domain-only patterns, the trailing / may be
2163 www.example.com/index.html
2165 matches only the single document /index.html on www.example.com.
2169 matches the document /index.html, regardless of the domain, i.e. on any web
2174 matches nothing, since it would be interpreted as a domain name and there
2175 is no top-level domain called .html.
2177 -------------------------------------------------------------------------------
2179 8.4.1. The Domain Pattern
2181 The matching of the domain part offers some flexible options: if the domain
2182 starts or ends with a dot, it becomes unanchored at that end. For example:
2186 matches any domain that ENDS in .example.com
2190 matches any domain that STARTS with www.
2194 matches any domain that CONTAINS .example. (Correctly speaking: It matches
2195 any FQDN that contains example as a domain.)
2197 Additionally, there are wild-cards that you can use in the domain names
2198 themselves. They work pretty similar to shell wild-cards: "*" stands for zero
2199 or more arbitrary characters, "?" stands for any single character, you can
2200 define character classes in square brackets and all of that can be freely
2205 matches "adserver.example.com", "ads.example.com", etc but not
2210 matches all of the above, and then some.
2214 matches www.ipix.com, pictures.epix.com, a.b.c.d.e.upix.com etc.
2216 www[1-9a-ez].example.c*
2218 matches www1.example.com, www4.example.cc, wwwd.example.cy,
2219 wwwz.example.com etc., but not wwww.example.com.
2221 -------------------------------------------------------------------------------
2223 8.4.2. The Path Pattern
2225 Privoxy uses Perl compatible regular expressions (through the PCRE library) for
2228 There is an Appendix with a brief quick-start into regular expressions, and
2229 full (very technical) documentation on PCRE regex syntax is available on-line
2230 at http://www.pcre.org/man.txt. You might also find the Perl man page on
2231 regular expressions (man perlre) useful, which is available on-line at http://
2232 www.perldoc.com/perl5.6/pod/perlre.html.
2234 Note that the path pattern is automatically left-anchored at the "/", i.e. it
2235 matches as if it would start with a "^" (regular expression speak for the
2236 beginning of a line).
2238 Please also note that matching in the path is CASE INSENSITIVE by default, but
2239 you can switch to case sensitive at any point in the pattern by using the "(?
2240 -i)" switch: www.example.com/(?-i)PaTtErN.* will match only documents whose
2241 path starts with PaTtErN in exactly this capitalization.
2243 -------------------------------------------------------------------------------
2247 All actions are disabled by default, until they are explicitly enabled
2248 somewhere in an actions file. Actions are turned on if preceded with a "+", and
2249 turned off if preceded with a "-". So a +action means "do that action", e.g.
2250 +block means "please block URLs that match the following patterns", and -block
2251 means "don't block URLs that match the following patterns, even if +block
2252 previously applied."
2254 Again, actions are invoked by placing them on a line, enclosed in curly braces
2255 and separated by whitespace, like in {+some-action -some-other-action
2256 {some-parameter}}, followed by a list of URL patterns, one per line, to which
2257 they apply. Together, the actions line and the following pattern lines make up
2258 a section of the actions file.
2260 There are three classes of actions:
2262 * Boolean, i.e the action can only be "enabled" or "disabled". Syntax:
2264 +name # enable action name
2265 -name # disable action name
2269 * Parameterized, where some value is required in order to enable this type of
2272 +name{param} # enable action and set parameter to param,
2273 # overwriting parameter from previous match if necessary
2274 -name # disable action. The parameter can be omitted
2276 Note that if the URL matches multiple positive forms of a parameterized
2277 action, the last match wins, i.e. the params from earlier matches are
2280 Example: +hide-user-agent{ Mozilla 1.0 }
2282 * Multi-value. These look exactly like parameterized actions, but they behave
2283 differently: If the action applies multiple times to the same URL, but with
2284 different parameters, all the parameters from all matches are remembered.
2285 This is used for actions that can be executed for the same request
2286 repeatedly, like adding multiple headers, or filtering through multiple
2289 +name{param} # enable action and add param to the list of parameters
2290 -name{param} # remove the parameter param from the list of parameters
2291 # If it was the last one left, disable the action.
2292 -name # disable this action completely and remove all parameters from the list
2294 Examples: +add-header{X-Fun-Header: Some text} and +filter{html-annoyances}
2296 If nothing is specified in any actions file, no "actions" are taken. So in this
2297 case Privoxy would just be a normal, non-blocking, non-anonymizing proxy. You
2298 must specifically enable the privacy and blocking features you need (although
2299 the provided default actions files will give a good starting point).
2301 Later defined actions always over-ride earlier ones. So exceptions to any rules
2302 you make, should come in the latter part of the file (or in a file that is
2303 processed later when using multiple actions files). For multi-valued actions,
2304 the actions are applied in the order they are specified. Actions files are
2305 processed in the order they are defined in config (the default installation has
2306 three actions files). It also quite possible for any given URL pattern to match
2307 more than one pattern and thus more than one set of actions!
2309 The list of valid Privoxy actions are:
2311 -------------------------------------------------------------------------------
2317 Confuse log analysis, custom applications
2321 Sends a user defined HTTP header to the web server.
2329 Any string value is possible. Validity of the defined HTTP headers is not
2330 checked. It is recommended that you use the "X-" prefix for custom headers.
2334 This action may be specified multiple times, in order to define multiple
2335 headers. This is rarely needed for the typical user. If you don't know what
2336 "HTTP headers" are, you definitely don't need to worry about this one.
2340 +add-header{X-User-Tracking: sucks}
2342 -------------------------------------------------------------------------------
2348 Block ads or other obnoxious content
2352 Requests for URLs to which this action applies are blocked, i.e. the
2353 requests are not forwarded to the remote server, but answered locally with
2354 a substitute page or image, as determined by the handle-as-image and
2355 set-image-blocker actions.
2367 Privoxy sends a special "BLOCKED" page for requests to blocked pages. This
2368 page contains links to find out why the request was blocked, and a
2369 click-through to the blocked content (the latter only if compiled with the
2370 force feature enabled). The "BLOCKED" page adapts to the available screen
2371 space -- it displays full-blown if space allows, or miniaturized and
2372 text-only if loaded into a small frame or window. If you are using Privoxy
2373 right now, you can take a look at the "BLOCKED" page.
2375 A very important exception occurs if both block and handle-as-image, apply
2376 to the same request: it will then be replaced by an image. If
2377 set-image-blocker (see below) also applies, the type of image will be
2378 determined by its parameter, if not, the standard checkerboard pattern is
2381 It is important to understand this process, in order to understand how
2382 Privoxy deals with ads and other unwanted content.
2384 The filter action can perform a very similar task, by "blocking" banner
2385 images and other content through rewriting the relevant URLs in the
2386 document's HTML source, so they don't get requested in the first place.
2387 Note that this is a totally different technique, and it's easy to confuse
2390 Example usage (section):
2392 {+block} # Block and replace with "blocked" page
2393 .nasty-stuff.example.com
2395 {+block +handle-as-image} # Block and replace with image
2399 -------------------------------------------------------------------------------
2401 8.5.3. crunch-incoming-cookies
2405 Prevent the web server from setting any cookies on your system
2409 Deletes any "Set-Cookie:" HTTP headers from server replies.
2421 This action is only concerned with incoming cookies. For outgoing cookies,
2422 use crunch-outgoing-cookies. Use both to disable cookies completely.
2424 It makes no sense at all to use this action in conjunction with the
2425 session-cookies-only action, since it would prevent the session cookies
2426 from being set. See also filter-content-cookies.
2430 +crunch-incoming-cookies
2432 -------------------------------------------------------------------------------
2434 8.5.4. crunch-outgoing-cookies
2438 Prevent the web server from reading any cookies from your system
2442 Deletes any "Cookie:" HTTP headers from client requests.
2454 This action is only concerned with outgoing cookies. For incoming cookies,
2455 use crunch-incoming-cookies. Use both to disable cookies completely.
2457 It makes no sense at all to use this action in conjunction with the
2458 session-cookies-only action, since it would prevent the session cookies
2463 +crunch-outgoing-cookies
2465 -------------------------------------------------------------------------------
2467 8.5.5. deanimate-gifs
2471 Stop those annoying, distracting animated GIF images.
2475 De-animate GIF animations, i.e. reduce them to their first or last image.
2487 This will also shrink the images considerably (in bytes, not pixels!). If
2488 the option "first" is given, the first frame of the animation is used as
2489 the replacement. If "last" is given, the last frame of the animation is
2490 used instead, which probably makes more sense for most banner animations,
2491 but also has the risk of not showing the entire last frame (if it is only a
2492 delta to an earlier frame).
2494 You can safely use this action with patterns that will also match non-GIF
2495 objects, because no attempt will be made at anything that doesn't look like
2500 +deanimate-gifs{last}
2502 -------------------------------------------------------------------------------
2504 8.5.6. downgrade-http-version
2508 Work around (very rare) problems with HTTP/1.1
2512 Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0.
2524 This is a left-over from the time when Privoxy didn't support important
2525 HTTP/1.1 features well. It is left here for the unlikely case that you
2526 experience HTTP/1.1 related problems with some server out there. Not all
2527 (optional) HTTP/1.1 features are supported yet, so there is a chance you
2528 might need this action.
2530 Example usage (section):
2532 {+downgrade-http-version}
2533 problem-host.example.com
2535 -------------------------------------------------------------------------------
2537 8.5.7. fast-redirects
2541 Fool some click-tracking scripts and speed up indirect links
2545 Cut off all but the last valid URL from requests.
2557 Many sites, like yahoo.com, don't just link to other sites. Instead, they
2558 will link to some script on their own servers, giving the destination as a
2559 parameter, which will then redirect you to the final target. URLs resulting
2560 from this scheme typically look like: http://some.place/click-tracker.cgi?
2561 target=http://some.where.else.
2563 Sometimes, there are even multiple consecutive redirects encoded in the
2564 URL. These redirections via scripts make your web browsing more traceable,
2565 since the server from which you follow such a link can see where you go to.
2566 Apart from that, valuable bandwidth and time is wasted, while your browser
2567 ask the server for one redirect after the other. Plus, it feeds the
2570 This feature is currently not very smart and is scheduled for improvement.
2571 It is likely to break some sites. You should expect to need possibly many
2572 exceptions to this action, if it is enabled by default in default.action.
2573 Some sites just don't work without it.
2579 -------------------------------------------------------------------------------
2585 Get rid of HTML and JavaScript annoyances, banner advertisements (by size),
2586 do fun text replacements, etc.
2590 Text documents, including HTML and JavaScript, to which this action
2591 applies, are filtered on-the-fly through the specified regular expression
2592 based substitutions.
2600 The name of a filter, as defined in the filter file (typically
2601 default.filter, set by the filterfile option in the config file). Filtering
2602 can be completely disabled without the use of parameters.
2606 For your convenience, there are a number of pre-defined filters available
2607 in the distribution filter file that you can use. See the examples below
2610 This is potentially a very powerful feature! But "rolling your own" filters
2611 requires a knowledge of regular expressions and HTML.
2613 Filtering requires buffering the page content, which may appear to slow
2614 down page rendering since nothing is displayed until all content has passed
2615 the filters. (It does not really take longer, but seems that way since the
2616 page is not incrementally displayed.) This effect will be more noticeable
2617 on slower connections.
2619 The amount of data that can be filtered is limited to the buffer-limit
2620 option in the main config file. The default is 4096 KB (4 Megs). Once this
2621 limit is exceeded, the buffered data, and all pending data, is passed
2624 Inappropriate MIME types, such as zipped files, are not filtered at all.
2625 Encrypted SSL data (from HTTPS servers) cannot be filtered either since
2626 this would violate the integrity of the secure transaction.
2628 At this time, Privoxy cannot (yet!) uncompress compressed documents. If you
2629 want filtering to work on all documents, even those that would normally be
2630 sent compressed, use the prevent-compression action in conjunction with
2633 Filtering can achieve some of the same effects as the block action, i.e. it
2634 can be used to block ads and banners. But the mechanism works quite
2635 differently. One effective use, is to block ad banners based on their size
2636 (see below), since many of these seem to be somewhat standardized.
2638 Feedback with suggestions for new or improved filters is particularly
2641 Example usage (with filters from the distribution default.filter file):
2643 +filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse
2645 +filter{js-events} # Kill all JS event bindings (Radically destructive! Only for extra nasty sites)
2647 +filter{html-annoyances} # Get rid of particularly annoying HTML abuse
2649 +filter{content-cookies} # Kill cookies that come in the HTML or JS content
2651 +filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups)
2653 +filter{unsolicited-popups} # Disable only unsolicited pop-up windows
2655 +filter{all-popups} # Kill all popups in JavaScript and HTML
2657 +filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective
2659 +filter{banners-by-size} # Kill banners by size
2661 +filter{banners-by-link} # Kill banners by their links to known clicktrackers
2663 +filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking)
2665 +filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap
2667 +filter{jumping-windows} # Prevent windows from resizing and moving themselves
2669 +filter{frameset-borders} # Give frames a border and make them resizable
2671 +filter{demoronizer} # Fix MS's non-standard use of standard charsets
2673 +filter{shockwave-flash} # Kill embedded Shockwave Flash objects
2675 +filter{quicktime-kioskmode} # Make Quicktime movies saveable
2677 +filter{fun} # Text replacements for subversive browsing fun!
2679 +filter{crude-parental} # Crude parental filtering (demo only)
2681 +filter{ie-exploits} # Disable some known Internet Explorer bug exploits
2683 -------------------------------------------------------------------------------
2685 8.5.9. handle-as-image
2689 Mark URLs as belonging to images (so they'll be replaced by images if they
2694 This action alone doesn't do anything noticeable. It just marks URLs as
2695 images. If the block action also applies, the presence or absence of this
2696 mark decides whether an HTML "blocked" page, or a replacement image (as
2697 determined by the set-image-blocker action) will be sent to the client as a
2698 substitute for the blocked content.
2710 The below generic example section is actually part of default.action. It
2711 marks all URLs with well-known image file name extensions as images and
2712 should be left intact.
2714 Users will probably only want to use the handle-as-image action in
2715 conjunction with block, to block sources of banners, whose URLs don't
2716 reflect the file type, like in the second example section.
2718 Note that you cannot treat HTML pages as images in most cases. For
2719 instance, (in-line) ad frames require an HTML page to be sent, or they
2720 won't display properly. Forcing handle-as-image in this situation will not
2721 replace the ad frame with an image, but lead to error messages.
2723 Example usage (sections):
2725 # Generic image extensions:
2728 /.*\.(gif|jpg|jpeg|png|bmp|ico)$
2730 # These don't look like images, but they're banners and should be
2731 # blocked as images:
2733 {+block +handle-as-image}
2734 some.nasty-banner-server.com/junk.cgi?output=trash
2736 # Banner source! Who cares if they also have non-image content?
2739 -------------------------------------------------------------------------------
2741 8.5.10. hide-forwarded-for-headers
2745 Improve privacy by hiding the true source of the request
2749 Deletes any existing "X-Forwarded-for:" HTTP header from client requests,
2750 and prevents adding a new one.
2762 It is fairly safe to leave this on.
2764 This action is scheduled for improvement: It should be able to generate
2765 forged "X-Forwarded-for:" headers using random IP addresses from a
2766 specified network, to make successive requests from the same client look
2767 like requests from a pool of different users sharing the same proxy.
2771 +hide-forwarded-for-headers
2773 -------------------------------------------------------------------------------
2775 8.5.11. hide-from-header
2779 Keep your (old and ill) browser from telling web servers your email address
2783 Deletes any existing "From:" HTTP header, or replaces it with the specified
2792 Keyword: "block", or any user defined value.
2796 The keyword "block" will completely remove the header (not to be confused
2797 with the block action).
2799 Alternately, you can specify any value you prefer to be sent to the web
2800 server. If you do, it is a matter of fairness not to use any address that
2801 is actually used by a real person.
2803 This action is rarely needed, as modern web browsers don't send "From:"
2808 +hide-from-header{block}
2812 +hide-from-header{spam-me-senseless@sittingduck.example.com}
2814 -------------------------------------------------------------------------------
2816 8.5.12. hide-referrer
2820 Conceal which link you followed to get to a particular site
2824 Deletes the "Referer:" (sic) HTTP header from the client request, or
2825 replaces it with a forged one.
2833 + "block" to delete the header completely.
2835 + "forge" to pretend to be coming from the homepage of the server we are
2838 + Any other string to set a user defined referrer.
2842 "forge" is the preferred option here, since some servers will not send
2843 images back otherwise, in an attempt to prevent their valuable content from
2844 being embedded elsewhere (and hence, without being surrounded by their
2847 hide-referer is an alternate spelling of hide-referrer and the two can be
2848 can be freely substituted with each other. ("referrer" is the correct
2849 English spelling, however the HTTP specification has a bug - it requires it
2850 to be spelled as "referer".)
2854 +hide-referrer{forge}
2858 +hide-referrer{http://www.yahoo.com/}
2860 -------------------------------------------------------------------------------
2862 8.5.13. hide-user-agent
2866 Conceal your type of browser and client operating system
2870 Replaces the value of the "User-Agent:" HTTP header in client requests with
2871 the specified value.
2879 Any user-defined string.
2883 +-----------------------------------------------------------------+
2885 |-----------------------------------------------------------------|
2886 |This breaks many web sites that depend on looking at this header |
2887 |in order to customize their content for different browsers |
2888 |(which, by the way, is NOT a smart way to do that!). |
2889 +-----------------------------------------------------------------+
2891 Using this action in multi-user setups or wherever different types of
2892 browsers will access the same Privoxy is not recommended. In single-user,
2893 single-browser setups, you might use it to delete your OS version
2894 information from the headers, because it is an invitation to exploit known
2895 bugs for your OS. It is also occasionally useful to forge this in order to
2896 access sites that won't let you in otherwise (though there may be a good
2897 reason in some cases). Example of this: some MSN sites will not let Mozilla
2898 enter, yet forging to a Netscape 6.1 user-agent works just fine. (Must be
2899 just a silly MS goof, I'm sure :-).
2901 This action is scheduled for improvement.
2905 +hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}
2907 -------------------------------------------------------------------------------
2913 Eliminate those annoying pop-up windows (deprecated)
2917 While loading the document, replace JavaScript code that opens pop-up
2918 windows with (syntactically neutral) dummy code on the fly.
2930 This action is basically a built-in, hardwired special-purpose filter
2931 action, but there are important differences: For kill-popups, the document
2932 need not be buffered, so it can be incrementally rendered while
2933 downloading. But kill-popups doesn't catch as many pop-ups as filter
2934 {all-popups} does and is not as smart as filter{unsolicited-popups} is.
2936 Think of it as a fast and efficient replacement for a filter that you can
2937 use if you don't want any filtering at all. Note that it doesn't make sense
2938 to combine it with any filter action, since as soon as one filter applies,
2939 the whole document needs to be buffered anyway, which destroys the
2940 advantage of the kill-popups action over its filter equivalent.
2942 Killing all pop-ups unconditionally is problematic. Many shops and banks
2943 rely on pop-ups to display forms, shopping carts etc, and the filter
2944 {unsolicited-popups} does a fairly good job of catching only the unwanted
2947 If the only kind of pop-ups that you want to kill are exit consoles (those
2948 really nasty windows that appear when you close an other one), you might
2949 want to use filter{js-annoyances} instead.
2955 -------------------------------------------------------------------------------
2957 8.5.15. limit-connect
2961 Prevent abuse of Privoxy as a TCP proxy relay
2965 Specifies to which ports HTTP CONNECT requests are allowable.
2973 A comma-separated list of ports or port ranges (the latter using dashes,
2974 with the minimum defaulting to 0 and the maximum to 65K).
2978 By default, i.e. if no limit-connect action applies, Privoxy only allows
2979 HTTP CONNECT requests to port 443 (the standard, secure HTTPS port). Use
2980 limit-connect if more fine-grained control is desired for some or all
2983 The CONNECT methods exists in HTTP to allow access to secure websites
2984 ("https://" URLs) through proxies. It works very simply: the proxy connects
2985 to the server on the specified port, and then short-circuits its
2986 connections to the client and to the remote server. This can be a big
2987 security hole, since CONNECT-enabled proxies can be abused as TCP relays
2990 If you don't know what any of this means, there probably is no reason to
2991 change this one, since the default is already very restrictive.
2995 +limit-connect{443} # This is the default and need not be specified.
2996 +limit-connect{80,443} # Ports 80 and 443 are OK.
2997 +limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
2998 +limit-connect{-} # All ports are OK (gaping security hole!)
3000 -------------------------------------------------------------------------------
3002 8.5.16. prevent-compression
3006 Ensure that servers send the content uncompressed, so it can be passed
3011 Adds a header to the request that asks for uncompressed transfer.
3023 More and more websites send their content compressed by default, which is
3024 generally a good idea and saves bandwidth. But for the filter,
3025 deanimate-gifs and kill-popups actions to work, Privoxy needs access to the
3026 uncompressed data. Unfortunately, Privoxy can't yet(!) uncompress, filter,
3027 and re-compress the content on the fly. So if you want to ensure that all
3028 websites, including those that normally compress, can be filtered, you need
3031 This will slow down transfers from those websites, though. If you use any
3032 of the above-mentioned actions, you will typically want to use
3033 prevent-compression in conjunction with them.
3035 Note that some (rare) ill-configured sites don't handle requests for
3036 uncompressed documents correctly (they send an empty document body). If you
3037 use prevent-compression per default, you'll have to add exceptions for
3038 those sites. See the example for how to do that.
3040 Example usage (sections):
3044 {+prevent-compression}
3047 # Make exceptions for ill sites:
3049 {-prevent-compression}
3051 www.pclinuxonline.com
3053 -------------------------------------------------------------------------------
3055 8.5.17. send-vanilla-wafer
3059 Feed log analysis scripts with useless data.
3063 Sends a cookie with each request stating that you do not accept any
3064 copyright on cookies sent to you, and asking the site operator not to track
3077 The vanilla wafer is a (relatively) unique header and could conceivably be
3080 This action is rarely used and not enabled in the default configuration.
3086 -------------------------------------------------------------------------------
3092 Send custom cookies or feed log analysis scripts with even more useless
3097 Sends a custom, user-defined cookie with each request.
3105 A string of the form "name=value".
3109 Being multi-valued, multiple instances of this action can apply to the same
3110 request, resulting in multiple cookies being sent.
3112 This action is rarely used and not enabled in the default configuration.
3114 Example usage (section):
3116 {+send-wafer{UsingPrivoxy=true}}
3117 my-internal-testing-server.void
3119 -------------------------------------------------------------------------------
3121 8.5.19. session-cookies-only
3125 Allow only temporary "session" cookies (for the current browser session
3130 Deletes the "expires" field from "Set-Cookie:" server headers. Most
3131 browsers will not store such cookies permanently and forget them in between
3144 This is less strict than crunch-incoming-cookies / crunch-outgoing-cookies
3145 and allows you to browse websites that insist or rely on setting cookies,
3146 without compromising your privacy too badly.
3148 Most browsers will not permanently store cookies that have been processed
3149 by session-cookies-only and will forget about them between sessions. This
3150 makes profiling cookies useless, but won't break sites which require
3151 cookies so that you can log in for transactions. This is generally turned
3152 on for all sites, and is the recommended setting.
3154 It makes no sense at all to use session-cookies-only together with
3155 crunch-incoming-cookies or crunch-outgoing-cookies. If you do, cookies will
3158 Note that it is up to the browser how it handles such cookies without an
3159 "expires" field. If you use an exotic browser, you might want to try it out
3162 This setting also has no effect on cookies that may have been stored
3163 previously by the browser before starting Privoxy. These would have to be
3166 Privoxy also uses the content-cookies filter to block some types of
3167 cookies. Content cookies are not effected by session-cookies-only.
3171 +session-cookies-only
3173 -------------------------------------------------------------------------------
3175 8.5.20. set-image-blocker
3179 Choose the replacement for blocked images
3183 This action alone doesn't do anything noticeable. If both block and
3184 handle-as-image also apply, i.e. if the request is to be blocked as an
3185 image, then the parameter of this action decides what will be sent as a
3194 + "pattern" to send a built-in checkerboard pattern image. The image is
3195 visually decent, scales very well, and makes it obvious where banners
3198 + "blank" to send a built-in transparent image. This makes banners
3199 disappear completely, but makes it hard to detect where Privoxy has
3200 blocked images on a given page and complicates troubleshooting if
3201 Privoxy has blocked innocent images, like navigation icons.
3203 + "target-url" to send a redirect to target-url. You can redirect to any
3204 image anywhere, even in your local filesystem (via "file:///" URL).
3206 A good application of redirects is to use special Privoxy-built-in
3207 URLs, which send the built-in images, as target-url. This has the same
3208 visual effect as specifying "blank" or "pattern" in the first place,
3209 but enables your browser to cache the replacement image, instead of
3210 requesting it over and over again.
3214 The URLs for the built-in images are "http://config.privoxy.org/
3215 send-banner?type=type", where type is either "blank" or "pattern".
3217 There is a third (advanced) type, called "auto". It is NOT to be used in
3218 set-image-blocker, but meant for use from filters. Auto will select the
3219 type of image that would have applied to the referring page, had it been an
3226 +set-image-blocker{pattern}
3228 Redirect to the BSD devil:
3230 +set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}
3232 Redirect to the built-in pattern for better caching:
3234 +set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}
3236 -------------------------------------------------------------------------------
3240 Note that many of these actions have the potential to cause a page to
3241 misbehave, possibly even not to display at all. There are many ways a site
3242 designer may choose to design his site, and what HTTP header content, and other
3243 criteria, he may depend on. There is no way to have hard and fast rules for all
3244 sites. See the Appendix for a brief example on troubleshooting actions.
3246 -------------------------------------------------------------------------------
3250 Custom "actions", known to Privoxy as "aliases", can be defined by combining
3251 other actions. These can in turn be invoked just like the built-in actions.
3252 Currently, an alias name can contain any character except space, tab, "=", "{"
3253 and "}", but we strongly recommend that you only use "a" to "z", "0" to "9",
3254 "+", and "-". Alias names are not case sensitive, and are not required to start
3255 with a "+" or "-" sign, since they are merely textually expanded.
3257 Aliases can be used throughout the actions file, but they must be defined in a
3258 special section at the top of the file! And there can only be one such section
3259 per actions file. Each actions file may have its own alias section, and the
3260 aliases defined in it are only visible within that file.
3262 There are two main reasons to use aliases: One is to save typing for frequently
3263 used combinations of actions, the other one is a gain in flexibility: If you
3264 decide once how you want to handle shops by defining an alias called "shop",
3265 you can later change your policy on shops in one place, and your changes will
3266 take effect everywhere in the actions file where the "shop" alias is used.
3267 Calling aliases by their purpose also makes your actions files more readable.
3269 Currently, there is one big drawback to using aliases, though: Privoxy's
3270 built-in web-based action file editor honors aliases when reading the actions
3271 files, but it expands them before writing. So the effects of your aliases are
3272 of course preserved, but the aliases themselves are lost when you edit sections
3273 that use aliases with it. This is likely to change in future versions of
3276 Now let's define some aliases...
3278 # Useful custom aliases we can use later.
3280 # Note the (required!) section header line and that this section
3281 # must be at the top of the actions file!
3285 # These aliases just save typing later:
3286 # (Note that some already use other aliases!)
3288 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
3289 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
3290 block-as-image = +block +handle-as-image
3291 mercy-for-cookies = -crunch-all-cookies -session-cookies-only -filter{content-cookies}
3293 # These aliases define combinations of actions
3294 # that are useful for certain types of sites:
3296 fragile = -block -filter -crunch-all-cookies -fast-redirects -hide-referrer -kill-popups
3297 shop = -crunch-all-cookies -filter{all-popups} -kill-popups
3299 # Short names for other aliases, for really lazy people ;-)
3301 c0 = +crunch-all-cookies
3302 c1 = -crunch-all-cookies
3304 ...and put them to use. These sections would appear in the lower part of an
3305 actions file and define exceptions to the default actions (as specified further
3306 up for the "/" pattern):
3308 # These sites are either very complex or very keen on
3309 # user data and require minimal interference to work:
3312 .office.microsoft.com
3313 .windowsupdate.microsoft.com
3317 # Allow cookies (for setting and retrieving your customer data)
3321 .worldpay.com # for quietpc.com
3324 # These shops require pop-ups:
3326 {shop -kill-popups -filter{all-popups}}
3330 Aliases like "shop" and "fragile" are often used for "problem" sites that
3331 require some actions to be disabled in order to function properly.
3333 -------------------------------------------------------------------------------
3335 8.7. Actions Files Tutorial
3337 The above chapters have shown which actions files there are and how they are
3338 organized, how actions are specified and applied to URLs, how patterns work,
3339 and how to define and use aliases. Now, let's look at an example default.action
3340 and user.action file and see how all these pieces come together:
3342 -------------------------------------------------------------------------------
3344 8.7.1. default.action
3346 Every config file should start with a short comment stating its purpose:
3348 # Sample default.action file <developers@privoxy.org>
3350 Then, since this is the default.action file, the first section is a special
3351 section for internal use that you needn't change or worry about:
3353 ##########################################################################
3354 # Settings -- Don't change! For internal Privoxy use ONLY.
3355 ##########################################################################
3358 for-privoxy-version=3.0
3360 After that comes the (optional) alias section. We'll use the example section
3361 from the above chapter on aliases, that also explains why and how aliases are
3364 ##########################################################################
3366 ##########################################################################
3369 # These aliases just save typing later:
3370 # (Note that some already use other aliases!)
3372 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
3373 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
3374 block-as-image = +block +handle-as-image
3375 mercy-for-cookies = -crunch-all-cookies -session-cookies-only -filter{content-cookies}
3377 # These aliases define combinations of actions
3378 # that are useful for certain types of sites:
3380 fragile = -block -filter -crunch-all-cookies -fast-redirects -hide-referrer -kill-popups
3381 shop = -crunch-all-cookies -filter{all-popups} -kill-popups
3383 Now come the regular sections, i.e. sets of actions, accompanied by URL
3384 patterns to which they apply. Remember all actions are disabled when matching
3385 starts, so we have to explicitly enable the ones we want.
3387 The first regular section is probably the most important. It has only one
3388 pattern, "/", but this pattern matches all URLs. Therefore, the set of actions
3389 used in this "default" section will be applied to all requests as a start. It
3390 can be partly or wholly overridden by later matches further down this file, or
3391 in user.action, but it will still be largely responsible for your overall
3392 browsing experience.
3394 Again, at the start of matching, all actions are disabled, so there is no real
3395 need to disable any actions here, but we will do that nonetheless, to have a
3396 complete listing for your reference. (Remember: a "+" preceding the action name
3397 enables the action, a "-" disables!). Also note how this long line has been
3398 made more readable by splitting it into multiple lines with line continuation.
3400 ##########################################################################
3401 # "Defaults" section:
3402 ##########################################################################
3406 -crunch-incoming-cookies \
3407 -crunch-outgoing-cookies \
3409 -downgrade-http-version \
3411 +filter{js-annoyances} \
3412 -filter{js-events} \
3413 +filter{html-annoyances} \
3414 -filter{content-cookies} \
3415 +filter{refresh-tags} \
3416 +filter{unsolicited-popups} \
3417 -filter{all-popups} \
3418 +filter{img-reorder} \
3419 +filter{banners-by-size} \
3420 -filter{banners-by-link} \
3422 -filter{tiny-textforms} \
3423 +filter{jumping-windows} \
3424 -filter{frameset-borders} \
3425 +filter{demoronizer} \
3426 -filter{shockwave-flash} \
3427 -filter{quicktime-kioskmode} \
3429 -filter{crude-parental} \
3430 +filter{ie-exploits} \
3432 +hide-forwarded-for-headers \
3433 +hide-from-header{block} \
3434 +hide-referrer{forge} \
3438 +prevent-compression \
3439 -send-vanilla-wafer \
3441 +session-cookies-only \
3442 +set-image-blocker{pattern} \
3444 / # forward slash will match *all* potential URL patterns.
3446 The default behavior is now set. Note that some actions, like not hiding the
3447 user agent, are part of a "general policy" that applies universally and won't
3448 get any exceptions defined later. Other choices, like not blocking (which is
3449 understandably the default!) need exceptions, i.e. we need to specify
3450 explicitly what we want to block in later sections.
3452 The first of our specialized sections is concerned with "fragile" sites, i.e.
3453 sites that require minimum interference, because they are either very complex
3454 or very keen on tracking you (and have mechanisms in place that make them
3455 unusable for people who avoid being tracked). We will simply use our
3456 pre-defined fragile alias instead of stating the list of actions explicitly:
3458 ##########################################################################
3459 # Exceptions for sites that'll break under the default action set:
3460 ##########################################################################
3462 # "Fragile" Use a minimum set of actions for these sites (see alias above):
3465 .office.microsoft.com # surprise, surprise!
3466 .windowsupdate.microsoft.com
3468 Shopping sites are not as fragile, but they typically require cookies to log
3469 in, and pop-up windows for shopping carts or item details. Again, we'll use a
3476 .worldpay.com # for quietpc.com
3480 The fast-redirects action, which we enabled per default above, breaks some
3481 sites. So disable it for popular sites where we know it misbehaves:
3487 .altavista.com/.*(like|url|link):http
3488 .altavista.com/trans.*urltext=http
3491 It is important that Privoxy knows which URLs belong to images, so that if they
3492 are to be blocked, a substitute image can be sent, rather than an HTML page.
3493 Contacting the remote site to find out is not an option, since it would destroy
3494 the loading time advantage of banner blocking, and it would feed the
3495 advertisers (in terms of money and information). We can mark any URL as an
3496 image with the handle-as-image action, and marking all URLs that end in a known
3497 image file extension is a good start:
3499 ##########################################################################
3501 ##########################################################################
3503 # Define which file types will be treated as images, in case they get
3504 # blocked further down this file:
3506 { +handle-as-image }
3507 /.*\.(gif|jpe?g|png|bmp|ico)$
3509 And then there are known banner sources. They often use scripts to generate the
3510 banners, so it won't be visible from the URL that the request is for an image.
3511 Hence we block them and mark them as images in one go, with the help of our
3512 block-as-image alias defined above. (We could of course just as well use +block
3513 +handle-as-image here.) Remember that the type of the replacement image is
3514 chosen by the set-image-blocker action. Since all URLs have matched the default
3515 section with its +set-image-blocker{pattern} action before, it still applies
3516 and needn't be repeated:
3518 # Known ad generators:
3523 .ad.*.doubleclick.net
3524 .a.yimg.com/(?:(?!/i/).)*$
3525 .a[0-9].yimg.com/(?:(?!/i/).)*$
3530 One of the most important jobs of Privoxy is to block banners. A huge bunch of
3531 them are already "blocked" by the filter{banners-by-size} action, which we
3532 enabled above, and which deletes the references to banner images from the pages
3533 while they are loaded, so the browser doesn't request them anymore, and hence
3534 they don't need to be blocked here. But this naturally doesn't catch all
3535 banners, and some people choose not to use filters, so we need a comprehensive
3536 list of patterns for banner URLs here, and apply the block action to them.
3538 First comes a bunch of generic patterns, which do most of the work, by matching
3539 typical domain and path name components of banners. Then comes a list of
3540 individual patterns for specific sites, which is omitted here to keep the
3543 ##########################################################################
3544 # Block these fine banners:
3545 ##########################################################################
3554 /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
3555 /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
3557 # Site-specific patterns (abbreviated):
3561 You wouldn't believe how many advertisers actually call their banner servers
3562 ads.company.com, or call the directory in which the banners are stored simply
3563 "banners". So the above generic patterns are surprisingly effective.
3565 But being very generic, they necessarily also catch URLs that we don't want to
3566 block. The pattern .*ads. e.g. catches "nasty-ads.nasty-corp.com" as intended,
3567 but also "downloads.sourcefroge.net" or "adsl.some-provider.net." So here come
3568 some well-known exceptions to the +block section above.
3570 Note that these are exceptions to exceptions from the default! Consider the URL
3571 "downloads.sourcefroge.net": Initially, all actions are deactivated, so it
3572 wouldn't get blocked. Then comes the defaults section, which matches the URL,
3573 but just deactivates the block action once again. Then it matches .*ads., an
3574 exception to the general non-blocking policy, and suddenly +block applies. And
3575 now, it'll match .*loads., where -block applies, so (unless it matches again
3576 further down) it ends up with no block action applying.
3578 ##########################################################################
3579 # Save some innocent victims of the above generic block patterns:
3580 ##########################################################################
3585 adv[io]*. # (for advogato.org and advice.*)
3586 adsl. # (has nothing to do with ads)
3587 ad[ud]*. # (adult.* and add.*)
3588 .edu # (universities don't host banners (yet!))
3589 .*loads. # (downloads, uploads etc)
3597 www.globalintersec.com/adv # (adv = advanced)
3598 www.ugu.com/sui/ugu/adv
3600 Filtering source code can have nasty side effects, so make an exception for our
3601 friends at sourceforge.net, and all paths with "cvs" in them. Note that -filter
3602 disables all filters in one fell swoop!
3604 # Don't filter code!
3610 The actual default.action is of course more comprehensive, but we hope this
3611 example made clear how it works.
3613 -------------------------------------------------------------------------------
3617 So far we are painting with a broad brush by setting general policies, which
3618 would be a reasonable starting point for many people. Now, you might want to be
3619 more specific and have customized rules that are more suitable to your personal
3620 habits and preferences. These would be for narrowly defined situations like
3621 your ISP or your bank, and should be placed in user.action, which is parsed
3622 after all other actions files and hence has the last word, over-riding any
3623 previously defined actions. user.action is also a safe place for your personal
3624 settings, since default.action is actively maintained by the Privoxy developers
3625 and you'll probably want to install updated versions from time to time.
3627 So let's look at a few examples of things that one might typically do in
3630 # My user.action file. <fred@foobar.com>
3632 As aliases are local to the actions file that they are defined in, you can't
3633 use the ones from default.action, unless you repeat them here:
3635 # Aliases are local to the file they are defined in.
3636 # (Re-)define aliases for this file:
3640 # These aliases just save typing later, and the alias names should
3641 # be self explanatory.
3643 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
3644 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
3645 allow-all-cookies = -crunch-all-cookies -session-cookies-only
3646 allow-popups = -filter{all-popups} -kill-popups
3647 +block-as-image = +block +handle-as-image
3648 -block-as-image = -block
3650 # These aliases define combinations of actions that are useful for
3651 # certain types of sites:
3653 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
3654 shop = -crunch-all-cookies allow-popups
3656 # Allow ads for selected useful free sites:
3658 allow-ads = -block -filter{banners-by-size} -filter{banners-by-link}
3660 Say you have accounts on some sites that you visit regularly, and you don't
3661 want to have to log in manually each time. So you'd like to allow persistent
3662 cookies for these sites. The allow-all-cookies alias defined above does exactly
3663 that, i.e. it disables crunching of cookies in any direction, and the
3664 processing of cookies to make them only temporary.
3666 { allow-all-cookies }
3673 Your bank is allergic to some filter, but you don't know which, so you disable
3677 .your-home-banking-site.com
3679 Some file types you may not want to filter. Privoxy makes no distinctions
3680 between regular web pages and downloads done via your web browser if it is an
3681 html or text type document.
3683 # A list of common file extensions that are likely to indicate raw text, and best
3685 /(.*/)?.*\.(pl|(s|p)?h|c(c|xx|pp)?|tcl|am|init?|cfg?|conf(ig)?|txt|rc|bat)$
3687 # Documentation should not need filtering (at least on some sites).
3690 Example of a simple block action. Say you've seen an ad on your favourite page
3691 on example.com that you want to get rid of. You have right-clicked the image,
3692 selected "copy image location" and pasted the URL below while removing the
3693 leading http://, into a { +block } section. Note that { +handle-as-image } need
3694 not be specified, since all URLs ending in .gif will be tagged as images by the
3695 general rules as set in default.action anyway:
3698 www.example.com/nasty-ads/sponsor.gif
3699 another.popular.site.net/more/junk/here/
3701 # Here we found one that is not in Privoxy's default blocked list:
3704 To force URLs that tend to have ad images, but it is difficult for Privoxy to
3705 know this since the ultimate returned object is obscured for one reason or
3706 another, we can try to force these to be treated as images (and thus avoid
3707 Privoxy's "BLOCKED" banner page). Note that if what is returned by the server
3708 turns out NOT to be an image, then your browser typically will display a broken
3709 icon image. Use cautiously.
3712 # A shockwave ad, very annoying.
3718 Now you noticed that the default configuration breaks Forbes Magazine, but you
3719 were too lazy to find out which action is the culprit, and you were again too
3720 lazy to give feedback, so you just used the fragile alias on the site, and --
3721 whoa! -- it worked. The fragile aliases disables those actions that are most
3722 likely to break a site. Also, good for testing purposes to see if it is Privoxy
3723 that is causing the problem or not.
3728 You like the "fun" text replacements in default.filter, but it is disabled in
3729 the distributed actions file. (My colleagues on the team just don't have a
3730 sense of humour, that's why! ;-). So you'd like to turn it on in your private,
3731 update-safe config, once and for all:
3736 Note that the above is not really a good idea: There are exceptions to the
3737 filters in default.action for things that really shouldn't be filtered, like
3738 code on CVS->Web interfaces. Since user.action has the last word, these
3739 exceptions won't be valid for the "fun" filtering specified here.
3741 You might also worry about how your favourite free websites are funded, and
3742 find that they rely on displaying banner advertisements to survive. So you
3743 might want to specifically allow banners for those sites that you feel provide
3751 Note that allow-ads has been aliased to -block, -filter{banners-by-size}, and -
3752 filter{banners-by-link} above.
3754 user.action is generally the best place to define exceptions and additions to
3755 the default policies of default.action. Some actions are safe to have their
3756 default policies set here though. So let's set a default policy to have a
3757 "blank" image as opposed to the checkerboard pattern for ALL sites. "/" of
3758 course matches all URL paths and patterns:
3760 { +set-image-blocker{blank} }
3763 -------------------------------------------------------------------------------
3767 All text substitutions that can be invoked through the filter action must first
3768 be defined in the filter file, which is typically called default.filter and
3769 which can be selected through the filterfile config option.
3771 Typical reasons for doing such substitutions are to eliminate common annoyances
3772 in HTML and JavaScript, such as pop-up windows, exit consoles, crippled windows
3773 without navigation tools, the infamous <BLINK> tag etc, to suppress images with
3774 certain width and height attributes (standard banner sizes or web-bugs), or
3775 just to have fun. The possibilities are endless.
3777 Filtering works on any text-based document type, including plain text, HTML,
3778 JavaScript, CSS etc. (all text/* MIME types). Substitutions are made at the
3779 source level, so if you want to "roll your own" filters, you should be familiar
3782 Just like the actions files, the filter file is organized in sections, which
3783 are called filters here. Each filter consists of a heading line, that starts
3784 with the keyword FILTER:, followed by the filter's name, and a short (one line)
3785 description of what it does. Below that line come the jobs, i.e. lines that
3786 define the actual text substitutions. By convention, the name of a filter
3787 should describe what the filter eliminates. The comment is used in the
3788 web-based user interface.
3790 Once a filter called name has been defined in the filter file, it can be
3791 invoked by using an action of the form +filter{name} in any actions file.
3793 A filter header line for a filter called "foo" could look like this:
3795 FILTER: foo Replace all "foo" with "bar"
3797 Below that line, and up to the next header line, come the jobs that define what
3798 text replacements the filter executes. They are specified in a syntax that
3799 imitates Perl's s/// operator. If you are familiar with Perl, you will find
3800 this to be quite intuitive, and may want to look at the PCRS man page for the
3801 subtle differences to Perl behaviour. Most notably, the non-standard option
3802 letter U is supported, which turns the default to ungreedy matching.
3804 If you are new to regular expressions, you might want to take a look at the
3805 Appendix on regular expressions, and see the Perl manual for the s///
3806 operator's syntax and Perl-style regular expressions in general. The below
3807 examples might also help to get you started.
3809 -------------------------------------------------------------------------------
3811 9.1. Filter File Tutorial
3813 Now, let's complete our "foo" filter. We have already defined the heading, but
3814 the jobs are still missing. Since all it does is to replace "foo" with "bar",
3815 there is only one (trivial) job needed:
3819 But wait! Didn't the comment say that all occurrences of "foo" should be
3820 replaced? Our current job will only take care of the first "foo" on each page.
3821 For global substitution, we'll need to add the g option:
3825 Our complete filter now looks like this:
3827 FILTER: foo Replace all "foo" with "bar"
3830 Let's look at some real filters for more interesting examples. Here you see a
3831 filter that protects against some common annoyances that arise from JavaScript
3832 abuse. Let's look at its jobs one after the other:
3834 FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse
3836 # Get rid of JavaScript referrer tracking. Test page: http://www.randomoddness.com/untitled.htm
3838 s|(<script.*)document\.referrer(.*</script>)|$1"Not Your Business!"$2|Usg
3840 Following the header line and a comment, you see the job. Note that it uses |
3841 as the delimiter instead of /, because the pattern contains a forward slash,
3842 which would otherwise have to be escaped by a backslash (\).
3844 Now, let's examine the pattern: it starts with the text <script.* enclosed in
3845 parentheses. Since the dot matches any character, and * means: "Match an
3846 arbitrary number of the element left of myself", this matches "<script",
3847 followed by any text, i.e. it matches the whole page, from the start of the
3850 That's more than we want, but the pattern continues: document\.referrer matches
3851 only the exact string "document.referrer". The dot needed to be escaped, i.e.
3852 preceded by a backslash, to take away its special meaning as a joker, and make
3853 it just a regular dot. So far, the meaning is: Match from the start of the
3854 first <script> tag in a the page, up to, and including, the text
3855 "document.referrer", if both are present in the page (and appear in that
3858 But there's still more pattern to go. The next element, again enclosed in
3859 parentheses, is .*</script>. You already know what .* means, so the whole
3860 pattern translates to: Match from the start of the first <script> tag in a page
3861 to the end of the last <script> tag, provided that the text "document.referrer"
3862 appears somewhere in between.
3864 This is still not the whole story, since we have ignored the options and the
3865 parentheses: The portions of the page matched by sub-patterns that are enclosed
3866 in parentheses, will be remembered and be available through the variables $1,
3867 $2, ... in the substitute. The U option switches to ungreedy matching, which
3868 means that the first .* in the pattern will only "eat up" all text in between "
3869 <script" and the first occurrence of "document.referrer", and that the second .
3870 * will only span the text up to the first "</script>" tag. Furthermore, the s
3871 option says that the match may span multiple lines in the page, and the g
3872 option again means that the substitution is global.
3874 So, to summarize, the pattern means: Match all scripts that contain the text
3875 "document.referrer". Remember the parts of the script from (and including) the
3876 start tag up to (and excluding) the string "document.referrer" as $1, and the
3877 part following that string, up to and including the closing tag, as $2.
3879 Now the pattern is deciphered, but wasn't this about substituting things? So
3880 lets look at the substitute: $1"Not Your Business!"$2 is easy to read: The text
3881 remembered as $1, followed by "Not Your Business!" (including the quotation
3882 marks!), followed by the text remembered as $2. This produces an exact copy of
3883 the original string, with the middle part (the "document.referrer") replaced by
3884 "Not Your Business!".
3886 The whole job now reads: Replace "document.referrer" by "Not Your Business!"
3887 wherever it appears inside a <script> tag. Note that this job won't break
3888 JavaScript syntax, since both the original and the replacement are
3889 syntactically valid string objects. The script just won't have access to the
3890 referrer information anymore.
3892 We'll show you two other jobs from the JavaScript taming department, but this
3893 time only point out the constructs of special interest:
3895 # The status bar is for displaying link targets, not pointless blahblah
3897 s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig
3899 \s stands for whitespace characters (space, tab, newline, carriage return, form
3900 feed), so that \s* means: "zero or more whitespace". The ? in .*? makes this
3901 matching of arbitrary text ungreedy. (Note that the U option is not set). The
3902 ['"] construct means: "a single or a double quote". Finally, \1 is a
3903 backreference to the first parenthesis just like $1 above, with the difference
3904 that in the pattern, a backslash indicates a backreference, whereas in the
3905 substitute, it's the dollar.
3907 So what does this job do? It replaces assignments of single- or double-quoted
3908 strings to the "window.status" object with a dummy assignment (using a variable
3909 name that is hopefully odd enough not to conflict with real variables in
3910 scripts). Thus, it catches many cases where e.g. pointless descriptions are
3911 displayed in the status bar instead of the link target when you move your mouse
3914 # Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html
3916 s/(<body [^>]*)onunload(.*>)/$1never$2/iU
3918 Including the OnUnload event binding in the HTML DOM was a CRIME. When I close
3919 a browser window, I want it to close and die. Basta. This job replaces the
3920 "onunload" attribute in "<body>" tags with the dummy word never. Note that the
3921 i option makes the pattern matching case-insensitive. Also note that ungreedy
3922 matching alone doesn't always guarantee a minimal match: In the first
3923 parenthesis, we had to use [^>]* instead of .* to prevent the match from
3924 exceeding the <body> tag if it doesn't contain "OnUnload", but the page's
3927 The last example is from the fun department:
3929 FILTER: fun Fun text replacements
3931 # Spice the daily news:
3933 s/microsoft(?!\.com)/MicroSuck/ig
3935 Note the (?!\.com) part (a so-called negative lookahead) in the job's pattern,
3936 which means: Don't match, if the string ".com" appears directly following
3937 "microsoft" in the page. This prevents links to microsoft.com from being
3938 trashed, while still replacing the word everywhere else.
3940 # Buzzword Bingo (example for extended regex syntax)
3942 s* industry[ -]leading \
3944 | customer[ -]focused \
3945 | market[ -]driven \
3946 | award[ -]winning # Comments are OK, too! \
3947 | high[ -]performance \
3948 | solutions[ -]based \
3952 *<font color="red"><b>BINGO!</b></font> \
3955 The x option in this job turns on extended syntax, and allows for e.g. the
3956 liberal use of (non-interpreted!) whitespace for nicer formatting.
3960 -------------------------------------------------------------------------------
3964 All Privoxy built-in pages, i.e. error pages such as the "404 - No Such Domain"
3965 error page, the "BLOCKED" page and all pages of its web-based user interface,
3966 are generated from templates. (Privoxy must be running for the above links to
3969 These templates are stored in a subdirectory of the configuration directory
3970 called templates. On Unixish platforms, this is typically /etc/privoxy/
3973 The templates are basically normal HTML files, but with place-holders (called
3974 symbols or exports), which Privoxy fills at run time. You can edit the
3975 templates with a normal text editor, should you want to customize them. (Not
3976 recommended for the casual user). Note that just like in configuration files,
3977 lines starting with # are ignored when the templates are filled in.
3979 The place-holders are of the form @name@, and you will find a list of available
3980 symbols, which vary from template to template, in the comments at the start of
3981 each file. Note that these comments are not always accurate, and that it's
3982 probably best to look at the existing HTML code to find out which symbols are
3983 supported and what they are filled in with.
3985 A special application of this substitution mechanism is to make whole blocks of
3986 HTML code disappear when a specific symbol is set. We use this for many
3987 purposes, one of them being to include the beta warning in all our user
3988 interface (CGI) pages when Privoxy in in an alpha or beta development stage:
3990 <!-- @if-unstable-start -->
3992 ... beta warning HTML code goes here ...
3994 <!-- if-unstable-end@ -->
3996 If the "unstable" symbol is set, everything in between and including
3997 @if-unstable-start and if-unstable-end@ will disappear, leaving nothing but an
4002 There's also an if-then-else construct and an #include mechanism, but you'll
4003 sure find out if you are inclined to edit the templates ;-)
4005 All templates refer to a style located at http://config.privoxy.org/
4006 send-stylesheet. This is, of course, locally served by Privoxy and the source
4007 for it can be found and edited in the cgi-style.css template.
4009 -------------------------------------------------------------------------------
4011 11. Contacting the Developers, Bug Reporting and Feature Requests
4013 We value your feedback. In fact, we rely on it to improve Privoxy and its
4014 configuration. However, please note the following hints, so we can provide you
4015 with the best support:
4017 -------------------------------------------------------------------------------
4021 For casual users, our support forum at SourceForge is probably best suited:
4022 http://sourceforge.net/tracker/?group_id=11118&atid=211118
4024 All users are of course welcome to discuss their issues on the users mailing
4025 list, where the developers also hang around.
4027 -------------------------------------------------------------------------------
4031 Please report all bugs only through our bug tracker: http://sourceforge.net/
4032 tracker/?group_id=11118&atid=111118.
4034 Before doing so, please make sure that the bug has not already been submitted
4035 and observe the additional hints at the top of the submit form.
4037 Please try to verify that it is a Privoxy bug, and not a browser or site bug
4038 first. If unsure, try toggling off Privoxy, and see if the problem persists.
4039 The appendix of the user manual also has helpful information on action
4040 debugging. If you are using your own custom configuration, please try the stock
4041 configs to see if the problem is configuration related.
4043 If not using the latest version, chances are that the bug has been found and
4044 fixed in the meantime. We would appreciate if you could take the time to
4045 upgrade to the latest version (or even the latest CVS snapshot) and verify your
4046 bug, but this is not required for reporting.
4048 -------------------------------------------------------------------------------
4050 11.3. Request New Features
4052 You are welcome to submit ideas on new features or other proposals for
4053 improvement through our feature request tracker at http://sourceforge.net/
4054 tracker/?atid=361118&group_id=11118.
4056 -------------------------------------------------------------------------------
4058 11.4. Report Ads or Other Actions-Related Problems
4060 Please send feedback on ads that slipped through, innocent images that were
4061 blocked, and any other problems relating to the default.action file through our
4062 actions feedback mechanism located at http://www.privoxy.org/actions/. On this
4063 page, you will also find a bookmark which will take you back there from any
4064 troubled site and even pre-fill the form!
4066 New, improved default.action files will occasionally be made available based on
4067 your feedback. These will be announced on the ijbswa-announce list and
4068 available from our the files section of our project page.
4070 -------------------------------------------------------------------------------
4074 For any other issues, feel free to use the mailing lists. Technically
4075 interested users and people who wish to contribute to the project are also
4076 welcome on the developers list! You can find an overview of all Privoxy-related
4077 mailing lists, including list archives, at: http://sourceforge.net/mail/?
4080 -------------------------------------------------------------------------------
4082 12. Privoxy Copyright, License and History
4084 Copyright © 2001, 2002 by Privoxy Developers <developers@privoxy.org>
4086 Some source code is based on code Copyright © 1997 by Anonymous Coders and
4087 Junkbusters, Inc. and licensed under the GNU General Public License.
4089 -------------------------------------------------------------------------------
4093 Privoxy is free software; you can redistribute it and/or modify it under the
4094 terms of the GNU General Public License, version 2, as published by the Free
4095 Software Foundation.
4097 This program is distributed in the hope that it will be useful, but WITHOUT ANY
4098 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
4099 PARTICULAR PURPOSE. See the GNU General Public License for more details, which
4100 is available from the Free Software Foundation, Inc, 59 Temple Place - Suite
4101 330, Boston, MA 02111-1307, USA.
4103 You should have received a copy of the GNU General Public License along with
4104 this program; if not, write to the
4107 Foundation, Inc. 59 Temple Place - Suite 330
4108 Boston, MA 02111-1307
4111 -------------------------------------------------------------------------------
4115 In the beginning, there was the Internet Junkbuster, by Anonymous Coders and
4116 Junkbusters Corporation. It saved many users a lot of pain in the early days of
4117 web advertising and user tracking.
4119 But the web, its protocols and standards, and with it, the techniques for
4120 forcing users to consume ads, give up autonomy over their browsing, and for
4121 spying on them, kept evolving. Unfortunately, the Internet Junkbuster did not.
4122 Version 2.0.2, published in 1998, was (and is) the last official release
4123 available from Junkbusters Corporation. Fortunately, it had been released under
4124 the GNU GPL, which allowed further development by others.
4126 So Stefan Waldherr started maintaining an improved version of the software, to
4127 which eventually a number of people contributed patches. It could already
4128 replace banners with a transparent image, and had a first version of pop-up
4129 killing, but it was still very closely based on the original, with all its
4130 limitations, such as the lack of HTTP/1.1 support, flexible per-site
4131 configuration, or content modification. The last release from this effort was
4132 version 2.0.2-10, published in 2000.
4134 Then, some developers picked up the thread, and started turning the software
4135 inside out, upside down, and then reassembled it, adding many new features
4138 The result of this is Privoxy, whose first stable release, 3.0, was released
4141 -------------------------------------------------------------------------------
4145 Current Project Developers:
4154 Current Project Contributors:
4157 Rodrigo Barbosa (RPM specfiles)
4161 Karsten Hopp (Red Hat)
4168 Roland Rosenfeld (Debian)
4169 Georg Sauthoff (Gentoo)
4170 David Schmidt (OS/2, Mac OSX ports)
4171 Joerg Strohmayer (Amiga)
4175 Based in part on code originally developed by:
4180 Thanks to the many people who have tested Privoxy, reported bugs, or made
4181 suggestions. These include (in alphabetical order):
4203 -------------------------------------------------------------------------------
4207 Other references and sites of interest to Privoxy users:
4209 http://www.privoxy.org/, the Privoxy Home page.
4211 http://www.privoxy.org/faq/, the Privoxy FAQ.
4213 http://sourceforge.net/projects/ijbswa/, the Project Page for Privoxy on
4216 http://config.privoxy.org/, the web-based user interface. Privoxy must be
4217 running for this to work. Shortcut: http://p.p/
4219 http://www.privoxy.org/actions/, to submit "misses" to the developers.
4221 http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/ijbswa/contrib/, cool and fun
4222 ideas from Privoxy users.
4224 http://www.junkbusters.com/ht/en/cookies.html, an explanation how cookies are
4225 used to track web users.
4227 http://www.junkbusters.com/ijb.html, the original Internet Junkbuster.
4229 http://www.waldherr.org/junkbuster/, Stefan Waldherr's version of Junkbuster,
4230 from which Privoxy was derived.
4232 http://privacy.net/analyze/, a useful site to check what information about you
4233 is leaked while you browse the web.
4235 http://www.squid-cache.org/, a very popular caching proxy, which is often used
4236 together with Privoxy.
4238 http://www.privoxy.org/developer-manual/, the Privoxy developer manual.
4240 -------------------------------------------------------------------------------
4244 14.1. Regular Expressions
4246 Privoxy uses Perl-style "regular expressions" in its actions files and filter
4247 file, through the PCRE and PCRS libraries.
4249 If you are reading this, you probably don't understand what "regular
4250 expressions" are, or what they can do. So this will be a very brief
4251 introduction only. A full explanation would require a book ;-)
4253 Regular expressions provide a language to describe patterns that can be run
4254 against strings of characters (letter, numbers, etc), to see if they match the
4255 string or not. The patterns are themselves (sometimes complex) strings of
4256 literal characters, combined with wild-cards, and other special characters,
4257 called meta-characters. The "meta-characters" have special meanings and are
4258 used to build complex patterns to be matched against. Perl Compatible Regular
4259 Expressions are an especially convenient "dialect" of the regular expression
4262 To make a simple analogy, we do something similar when we use wild-card
4263 characters when listing files with the dir command in DOS. *.* matches all
4264 filenames. The "special" character here is the asterisk which matches any and
4265 all characters. We can be more specific and use ? to match just individual
4266 characters. So "dir file?.text" would match "file1.txt", "file2.txt", etc. We
4267 are pattern matching, using a similar technique to "regular expressions"!
4269 Regular expressions do essentially the same thing, but are much, much more
4270 powerful. There are many more "special characters" and ways of building complex
4271 patterns however. Let's look at a few of the common ones, and then some
4274 . - Matches any single character, e.g. "a", "A", "4", ":", or "@".
4276 ? - The preceding character or expression is matched ZERO or ONE times. Either/
4279 + - The preceding character or expression is matched ONE or MORE times.
4281 * - The preceding character or expression is matched ZERO or MORE times.
4283 \ - The "escape" character denotes that the following character should be taken
4284 literally. This is used where one of the special characters (e.g. ".") needs to
4285 be taken literally and not as a special meta-character. Example: "example
4286 \.com", makes sure the period is recognized only as a period (and not expanded
4287 to its meta-character meaning of any single character).
4289 [] - Characters enclosed in brackets will be matched if any of the enclosed
4290 characters are encountered. For instance, "[0-9]" matches any numeric digit
4291 (zero through nine). As an example, we can combine this with "+" to match any
4292 digit one of more times: "[0-9]+".
4294 () - parentheses are used to group a sub-expression, or multiple
4297 | - The "bar" character works like an "or" conditional statement. A match is
4298 successful if the sub-expression on either side of "|" matches. As an example:
4299 "/(this|that) example/" uses grouping and the bar character and would match
4300 either "this example" or "that example", and nothing else.
4302 These are just some of the ones you are likely to use when matching URLs with
4303 Privoxy, and is a long way from a definitive list. This is enough to get us
4304 started with a few simple examples which may be more illuminating:
4306 /.*/banners/.* - A simple example that uses the common combination of "." and "
4307 *" to denote any character, zero or more times. In other words, any string at
4308 all. So we start with a literal forward slash, then our regular expression
4309 pattern (".*") another literal forward slash, the string "banners", another
4310 forward slash, and lastly another ".*". We are building a directory path here.
4311 This will match any file with the path that has a directory named "banners" in
4312 it. The ".*" matches any characters, and this could conceivably be more forward
4313 slashes, so it might expand into a much longer looking path. For example, this
4314 could match: "/eye/hate/spammers/banners/annoy_me_please.gif", or just "/
4315 banners/annoying.html", or almost an infinite number of other possible
4316 combinations, just so it has "banners" in the path somewhere.
4318 A now something a little more complex:
4320 /.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward
4321 slashes again ("/"), so we are building another expression that is a file path
4322 statement. We have another ".*", so we are matching against any conceivable
4323 sub-path, just so it matches our expression. The only true literal that must
4324 match our pattern is adv, together with the forward slashes. What comes after
4325 the "adv" string is the interesting part.
4327 Remember the "?" means the preceding expression (either a literal character or
4328 anything grouped with "(...)" in this case) can exist or not, since this means
4329 either zero or one match. So "((er)?ts?|ertis(ing|ements?))" is optional, as
4330 are the individual sub-expressions: "(er)", "(ing|ements?)", and the "s". The "
4331 |" means "or". We have two of those. For instance, "(ing|ements?)", can expand
4332 to match either "ing" OR "ements?". What is being done here, is an attempt at
4333 matching as many variations of "advertisement", and similar, as possible. So
4334 this would expand to match just "adv", or "advert", or "adverts", or
4335 "advertising", or "advertisement", or "advertisements". You get the idea. But
4336 it would not match "advertizements" (with a "z"). We could fix that by changing
4337 our regular expression to: "/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/", which
4338 would then match either spelling.
4340 /.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward
4341 slashes. Anything in the square brackets "[]" can be matched. This is using
4342 "0-9" as a shorthand expression to mean any digit one through nine. It is the
4343 same as saying "0123456789". So any digit matches. The "+" means one or more of
4344 the preceding expression must be included. The preceding expression here is
4345 what is in the square brackets -- in this case, any digit one through nine.
4346 Then, at the end, we have a grouping: "(gif|jpe?g)". This includes a "|", so
4347 this needs to match the expression on either side of that bar character also. A
4348 simple "gif" on one side, and the other side will in turn match either "jpeg"
4349 or "jpg", since the "?" means the letter "e" is optional and can be matched
4350 once or not at all. So we are building an expression here to match image GIF or
4351 JPEG type image file. It must include the literal string "advert", then one or
4352 more digits, and a "." (which is now a literal, and not a special character,
4353 since it is escaped with "\"), and lastly either "gif", or "jpeg", or "jpg".
4354 Some possible matches would include: "//advert1.jpg", "/nasty/ads/
4355 advert1234.gif", "/banners/from/hell/advert99.jpg". It would not match
4356 "advert1.gif" (no leading slash), or "/adverts232.jpg" (the expression does not
4357 include an "s"), or "/advert1.jsp" ("jsp" is not in the expression anywhere).
4359 We are barely scratching the surface of regular expressions here so that you
4360 can understand the default Privoxy configuration files, and maybe use this
4361 knowledge to customize your own installation. There is much, much more that can
4362 be done with regular expressions. Now that you know enough to get started, you
4363 can learn more on your own :/
4365 More reading on Perl Compatible Regular expressions: http://www.perldoc.com/
4366 perl5.6/pod/perlre.html
4368 For information on regular expression based substitutions and their
4369 applications in filters, please see the filter file tutorial in this manual.
4371 -------------------------------------------------------------------------------
4373 14.2. Privoxy's Internal Pages
4375 Since Privoxy proxies each requested web page, it is easy for Privoxy to trap
4376 certain special URLs. In this way, we can talk directly to Privoxy, and see how
4377 it is configured, see how our rules are being applied, change these rules and
4378 other configuration options, and even turn Privoxy's filtering off, all with a
4381 The URLs listed below are the special ones that allow direct access to Privoxy.
4382 Of course, Privoxy must be running to access these. If not, you will get a
4383 friendly error message. Internet access is not necessary either.
4385 * Privoxy main page:
4387 http://config.privoxy.org/
4389 There is a shortcut: http://p.p/ (But it doesn't provide a fall-back to a
4390 real page, in case the request is not sent through Privoxy)
4392 * Show information about the current configuration, including viewing and
4393 editing of actions files:
4395 http://config.privoxy.org/show-status
4397 * Show the source code version numbers:
4399 http://config.privoxy.org/show-version
4401 * Show the browser's request headers:
4403 http://config.privoxy.org/show-request
4405 * Show which actions apply to a URL and why:
4407 http://config.privoxy.org/show-url-info
4409 * Toggle Privoxy on or off. In this case, "Privoxy" continues to run, but
4410 only as a pass-through proxy, with no actions taking place:
4412 http://config.privoxy.org/toggle
4414 Short cuts. Turn off, then on:
4416 http://config.privoxy.org/toggle?set=disable
4418 http://config.privoxy.org/toggle?set=enable
4420 These may be bookmarked for quick reference. See next.
4422 -------------------------------------------------------------------------------
4424 14.2.1. Bookmarklets
4426 Below are some "bookmarklets" to allow you to easily access a "mini" version of
4427 some of Privoxy's special pages. They are designed for MS Internet Explorer,
4428 but should work equally well in Netscape, Mozilla, and other browsers which
4429 support JavaScript. They are designed to run directly from your bookmarks - not
4430 by clicking the links below (although that should work for testing).
4432 To save them, right-click the link and choose "Add to Favorites" (IE) or "Add
4433 Bookmark" (Netscape). You will get a warning that the bookmark "may not be
4434 safe" - just click OK. Then you can run the Bookmarklet directly from your
4435 favorites/bookmarks. For even faster access, you can put them on the "Links"
4436 bar (IE) or the "Personal Toolbar" (Netscape), and run them with a single
4443 * Privoxy - Toggle Privoxy (Toggles between enabled and disabled)
4445 * Privoxy- View Status
4447 * Privoxy - Submit Actions File Feedback
4451 Credit: The site which gave us the general idea for these bookmarklets is
4452 www.bookmarklets.com. They have more information about bookmarklets.
4454 -------------------------------------------------------------------------------
4456 14.3. Chain of Events
4458 Let's take a quick look at the basic sequence of events when a web page is
4459 requested by your browser and Privoxy is on duty:
4461 * First, your web browser requests a web page. The browser knows to send the
4462 request to Privoxy, which will in turn, relay the request to the remote web
4463 server after passing the following tests:
4465 * Privoxy traps any request for its own internal CGI pages (e.g http://p.p/)
4466 and sends the CGI page back to the browser.
4468 * Next, Privoxy checks to see if the URL matches any "+block" patterns. If
4469 so, the URL is then blocked, and the remote web server will not be
4470 contacted. "+handle-as-image" is then checked and if it does not match, an
4471 HTML "BLOCKED" page is sent back. Otherwise, if it does match, an image is
4472 returned. The type of image depends on the setting of "+set-image-blocker"
4473 (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
4475 * Untrusted URLs are blocked. If URLs are being added to the trust file, then
4478 * If the URL pattern matches the "+fast-redirects" action, it is then
4479 processed. Unwanted parts of the requested URL are stripped.
4481 * Now the rest of the client browser's request headers are processed. If any
4482 of these match any of the relevant actions (e.g. "+hide-user-agent", etc.),
4483 headers are suppressed or forged as determined by these actions and their
4486 * Now the web server starts sending its response back (i.e. typically a web
4487 page and related data).
4489 * First, the server headers are read and processed to determine, among other
4490 things, the MIME type (document type) and encoding. The headers are then
4491 filtered as determined by the "+crunch-incoming-cookies",
4492 "+session-cookies-only", and "+downgrade-http-version" actions.
4494 * If the "+kill-popups" action applies, and it is an HTML or JavaScript
4495 document, the popup-code in the response is filtered on-the-fly as it is
4498 * If a "+filter" or "+deanimate-gifs" action applies (and the document type
4499 fits the action), the rest of the page is read into memory (up to a
4500 configurable limit). Then the filter rules (from default.filter) are
4501 processed against the buffered content. Filters are applied in the order
4502 they are specified in the default.filter file. Animated GIFs, if present,
4503 are reduced to either the first or last frame, depending on the action
4504 setting.The entire page, which is now filtered, is then sent by Privoxy
4505 back to your browser.
4507 If neither "+filter" or "+deanimate-gifs" matches, then Privoxy passes the
4508 raw data through to the client browser as it becomes available.
4510 * As the browser receives the now (probably filtered) page content, it reads
4511 and then requests any URLs that may be embedded within the page source,
4512 e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
4513 frames), sounds, etc. For each of these objects, the browser issues a new
4514 request. And each such request is in turn processed as above. Note that a
4515 complex web page may have many such embedded URLs.
4517 -------------------------------------------------------------------------------
4519 14.4. Anatomy of an Action
4521 The way Privoxy applies actions and filters to any given URL can be complex,
4522 and not always so easy to understand what is happening. And sometimes we need
4523 to be able to see just what Privoxy is doing. Especially, if something Privoxy
4524 is doing is causing us a problem inadvertently. It can be a little daunting to
4525 look at the actions and filters files themselves, since they tend to be filled
4526 with regular expressions whose consequences are not always so obvious.
4528 One quick test to see if Privoxy is causing a problem or not, is to disable it
4529 temporarily. This should be the first troubleshooting step. See the
4530 Bookmarklets section on a quick and easy way to do this (be sure to flush
4531 caches afterward!). Looking at the logs is a good idea too.
4533 Privoxy also provides the http://config.privoxy.org/show-url-info page that can
4534 show us very specifically how actions are being applied to any given URL. This
4535 is a big help for troubleshooting.
4537 First, enter one URL (or partial URL) at the prompt, and then Privoxy will tell
4538 us how the current configuration will handle it. This will not help with
4539 filtering effects (i.e. the "+filter" action) from the default.filter file
4540 since this is handled very differently and not so easy to trap! It also will
4541 not tell you about any other URLs that may be embedded within the URL you are
4542 testing. For instance, images such as ads are expressed as URLs within the raw
4543 page source of HTML pages. So you will only get info for the actual URL that is
4544 pasted into the prompt area -- not any sub-URLs. If you want to know about
4545 embedded URLs like ads, you will have to dig those out of the HTML source. Use
4546 your browser's "View Page Source" option for this. Or right click on the ad,
4549 Let's try an example, google.com, and look at it one section at a time:
4551 Matches for http://google.com:
4553 In file: default.action [ View ] [ Edit ]
4557 -crunch-outgoing-cookies
4558 -crunch-incoming-cookies
4559 +deanimate-gifs{last}
4560 -downgrade-http-version
4564 -filter{shockwave-flash}
4565 -filter{crude-parental}
4566 +filter{html-annoyances}
4567 +filter{js-annoyances}
4568 +filter{content-cookies}
4570 +filter{refresh-tags}
4572 +filter{banners-by-size}
4573 +hide-forwarded-for-headers
4574 +hide-from-header{block}
4575 +hide-referer{forge}
4580 +prevent-compression
4583 +session-cookies-only
4584 +set-image-blocker{pattern} }
4587 { -session-cookies-only }
4593 In file: user.action [ View ] [ Edit ]
4594 (no matches in this file)
4596 This tells us how we have defined our "actions", and which ones match for our
4597 example, "google.com". The first listing is any matches for the standard.action
4598 file. No hits at all here on "standard". Then next is "default", or our
4599 default.action file. The large, multi-line listing, is how the actions are set
4600 to match for all URLs, i.e. our default settings. If you look at your "actions"
4601 file, this would be the section just below the "aliases" section near the top.
4602 This will apply to all URLs as signified by the single forward slash at the end
4603 of the listing -- "/".
4605 But we can define additional actions that would be exceptions to these general
4606 rules, and then list specific URLs (or patterns) that these exceptions would
4607 apply to. Last match wins. Just below this then are two explicit matches for
4608 ".google.com". The first is negating our previous cookie setting, which was for
4609 "+session-cookies-only" (i.e. not persistent). So we will allow persistent
4610 cookies for google. The second turns off any "+fast-redirects" action, allowing
4611 this to take place unmolested. Note that there is a leading dot here --
4612 ".google.com". This will match any hosts and sub-domains, in the google.com
4613 domain also, such as "www.google.com". So, apparently, we have these two
4614 actions defined somewhere in the lower part of our default.action file, and
4615 "google.com" is referenced somewhere in these latter sections.
4617 Then, for our user.action file, we again have no hits.
4619 And finally we pull it all together in the bottom section and summarize how
4620 Privoxy is applying all its "actions" to "google.com":
4626 -crunch-outgoing-cookies
4627 -crunch-incoming-cookies
4628 +deanimate-gifs{last}
4629 -downgrade-http-version
4633 -filter{shockwave-flash}
4634 -filter{crude-parental}
4635 +filter{html-annoyances}
4636 +filter{js-annoyances}
4637 +filter{content-cookies}
4639 +filter{refresh-tags}
4641 +filter{banners-by-size}
4642 +hide-forwarded-for-headers
4643 +hide-from-header{block}
4644 +hide-referer{forge}
4649 +prevent-compression
4652 -session-cookies-only
4653 +set-image-blocker{pattern}
4655 Notice the only difference here to the previous listing, is to "fast-redirects"
4656 and "session-cookies-only".
4658 Now another example, "ad.doubleclick.net":
4660 { +block +handle-as-image }
4663 { +block +handle-as-image }
4666 { +block +handle-as-image }
4669 We'll just show the interesting part here, the explicit matches. It is matched
4670 three different times. Each as an "+block +handle-as-image", which is the
4671 expanded form of one of our aliases that had been defined as: "+imageblock". (
4672 "Aliases" are defined in the first section of the actions file and typically
4673 used to combine more than one action.)
4675 Any one of these would have done the trick and blocked this as an unwanted
4676 image. This is unnecessarily redundant since the last case effectively would
4677 also cover the first. No point in taking chances with these guys though ;-)
4678 Note that if you want an ad or obnoxious URL to be invisible, it should be
4679 defined as "ad.doubleclick.net" is done here -- as both a "+block" and an
4680 "+handle-as-image". The custom alias "+imageblock" just simplifies the process
4681 and make it more readable.
4683 One last example. Let's try "http://www.rhapsodyk.net/adsl/HOWTO/". This one is
4684 giving us problems. We are getting a blank page. Hmmm ...
4686 Matches for http://www.rhapsodyk.net/adsl/HOWTO/:
4688 In file: default.action [ View ] [ Edit ]
4692 -crunch-incoming-cookies
4693 -crunch-outgoing-cookies
4695 -downgrade-http-version
4697 +filter{html-annoyances}
4698 +filter{js-annoyances}
4699 +filter{kill-popups}
4702 +filter{banners-by-size}
4705 +hide-forwarded-for-headers
4706 +hide-from-header{block}
4707 +hide-referer{forge}
4711 +prevent-compression
4714 +session-cookies-only
4715 +set-image-blocker{blank} }
4718 { +block +handle-as-image }
4721 Ooops, the "/adsl/" is matching "/ads"! But we did not want this at all! Now we
4722 see why we get the blank page. We could now add a new action below this that
4723 explicitly does not block ("{-block}") paths with "adsl". There are various
4724 ways to handle such exceptions. Example:
4729 Now the page displays ;-) Be sure to flush your browser's caches when making
4730 such changes. Or, try using Shift+Reload.
4732 But now what about a situation where we get no explicit matches like we did
4735 { +block +handle-as-image }
4738 That actually was very telling and pointed us quickly to where the problem was.
4739 If you don't get this kind of match, then it means one of the default rules in
4740 the first section is causing the problem. This would require some guesswork,
4741 and maybe a little trial and error to isolate the offending rule. One likely
4742 cause would be one of the "{+filter}" actions. These tend to be harder to
4743 troubleshoot. Try adding the URL for the site to one of aliases that turn off
4748 .worldpay.com # for quietpc.com
4753 "{shop}" is an "alias" that expands to "{ -filter -session-cookies-only }". Or
4754 you could do your own exception to negate filtering:
4759 This would turn off all filtering for that site. This would probably be most
4760 appropriately put in user.action, for local site exceptions.
4762 Images that are inexplicably being blocked, may well be hitting the "+filter
4763 {banners-by-size}" rule, which assumes that images of certain sizes are ad
4764 banners (works well most of the time since these tend to be standardized).
4766 "{fragile}" is an alias that disables most actions. This can be used as a last
4767 resort for problem sites. Remember to flush caches! If this still does not
4768 work, you will have to go through the remaining actions one by one to find
4769 which one(s) is causing the problem.
projects / privoxy.git / blob