3 Copyright © 2001, 2002 by Privoxy Developers
5 $Id: user-manual.sgml,v 1.117 2002/05/17 13:56:16 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 RPMs and Conectiva
36 2.1.4. Solaris, NetBSD, FreeBSD, HP-UX
41 2.2. Building from Source
44 4. Quickstart to Using Privoxy
46 4.1. Quickstart to Ad Blocking
50 5.1. RedHat, Conectiva and Debian
53 5.4. Solaris, NetBSD, FreeBSD, HP-UX and others
57 5.8. Command Line Options
59 6. Privoxy Configuration
61 6.1. Controlling Privoxy with Your Web Browser
62 6.2. Configuration Files Overview
64 7. The Main Configuration File
66 7.1. Configuration and Log File Locations
76 7.2. Local Set-up Documentation
86 7.3.2. single-threaded
88 7.4. Access Control and Security
92 7.4.3. enable-remote-toggle
93 7.4.4. enable-edit-actions
94 7.4.5. ACLs: permit-access and deny-access
100 7.5.2. forward-socks4 and forward-socks4a
101 7.5.3. Advanced Forwarding Examples
103 7.6. Windows GUI Options
107 8.1. Finding the Right Mix
109 8.3. How Actions are Applied to URLs
112 8.4.1. The Domain Pattern
113 8.4.2. The Path Pattern
119 8.5.3. crunch-incoming-cookies
120 8.5.4. crunch-outgoing-cookies
121 8.5.5. deanimate-gifs
122 8.5.6. downgrade-http-version
123 8.5.7. fast-redirects
125 8.5.9. handle-as-image
126 8.5.10. hide-forwarded-for-headers
127 8.5.11. hide-from-header
128 8.5.12. hide-referrer
129 8.5.13. hide-user-agent
131 8.5.15. limit-connect
132 8.5.16. prevent-compression
133 8.5.17. send-vanilla-wafer
135 8.5.19. session-cookies-only
136 8.5.20. set-image-blocker
140 8.7. Actions Files Tutorial
142 8.7.1. default.action
147 9.1. Filter File Tutorial
150 11. Contacting the Developers, Bug Reporting and Feature Requests
154 11.3. Request New Features
155 11.4. Report Ads or Other Actions-Related Problems
158 12. Privoxy Copyright, License and History
167 14.1. Regular Expressions
168 14.2. Privoxy's Internal Pages
172 14.3. Chain of Events
173 14.4. Anatomy of an Action
177 This documentation is included with the current beta version of Privoxy,
178 v.2.9.15, and is mostly complete at this point. The most up to date reference
179 for the time being is still the comments in the source files and in the
180 individual configuration files. Development of version 3.0 is currently nearing
181 completion, and includes many significant changes and enhancements over earlier
182 versions. The target release date for stable v3.0 is "soon" ;-).
184 Since this is a beta version, not all new features are well tested. This
185 documentation may be slightly out of sync as a result (especially with CVS
186 sources). And there may be bugs, though hopefully not many!
188 -------------------------------------------------------------------------------
192 In addition to Internet Junkbuster's traditional features of ad and banner
193 blocking and cookie management, Privoxy provides new features, some of them
194 currently under development:
196 * Integrated browser based configuration and control utility at http://
197 config.privoxy.org/ (shortcut: http://p.p/). Browser-based tracing of rule
198 and filter effects. Remote toggling.
200 * Web page content filtering (removes banners based on size, invisible
201 "web-bugs", JavaScript and HTML annoyances, pop-up windows, etc.)
203 * Modularized configuration that allows for standard settings and user
204 settings to reside in separate files, so that installing updated actions
205 files won't overwrite individual user settings.
207 * HTTP/1.1 compliant (but not all optional 1.1 features are supported).
209 * Support for Perl Compatible Regular Expressions in the configuration files,
210 and generally a more sophisticated and flexible configuration syntax over
213 * Improved cookie management features (e.g. session based cookies).
217 * Bypass many click-tracking scripts (avoids script redirection).
219 * Multi-threaded (POSIX and native threads).
221 * User-customizable HTML templates for all proxy-generated pages (e.g.
224 * Auto-detection and re-reading of config file changes.
226 * Improved signal handling, and a true daemon mode (Unix).
228 * Every feature now controllable on a per-site or per-location basis,
229 configuration more powerful and versatile over-all.
231 * Many smaller new features added, limitations and bugs removed, and security
234 -------------------------------------------------------------------------------
238 Privoxy is available both in convenient pre-compiled packages for a wide range
239 of operating systems, and as raw source code. For most users, we recommend
240 using the packages, which can be downloaded from our Privoxy Project Page.
242 Note: If you have a previous Junkbuster or Privoxy installation on your system,
243 you will need to remove it. On some platforms, this may be done for you as part
244 of their installation procedure. (See below for your platform). In any case be
245 sure to backup your old configuration if it is valuable to you. See the note to
246 upgraders section below.
248 -------------------------------------------------------------------------------
252 How to install the binary packages depends on your operating system:
254 -------------------------------------------------------------------------------
256 2.1.1. Red Hat, SuSE RPMs and Conectiva
258 RPMs can be installed with rpm -Uvh privoxy-2.9.15-1.rpm, and will use /etc/
259 privoxy for the location of configuration files.
261 Note that on Red Hat, Privoxy will not be automatically started on system boot.
262 You will need to enable that using chkconfig, ntsysv, or similar methods. Note
263 that SuSE will automatically start Privoxy in the boot process.
265 If you have problems with failed dependencies, try rebuilding the SRC RPM: rpm
266 --rebuild privoxy-2.9.15-1.src.rpm;. This will use your locally installed
267 libraries and RPM version.
269 Also note that if you have a Junkbuster RPM installed on your system, you need
270 to remove it first, because the packages conflict. Otherwise, RPM will try to
271 remove Junkbuster automatically, before installing Privoxy.
273 -------------------------------------------------------------------------------
279 -------------------------------------------------------------------------------
283 Just double-click the installer, which will guide you through the installation
284 process. You will find the configuration files in the same directory as you
285 installed Privoxy in. We do not use the registry of Windows.
287 -------------------------------------------------------------------------------
289 2.1.4. Solaris, NetBSD, FreeBSD, HP-UX
291 Create a new directory, cd to it, then unzip and untar the archive. For the
292 most part, you'll have to figure out where things go. FIXME.
294 -------------------------------------------------------------------------------
298 First, make sure that no previous installations of Junkbuster and / or Privoxy
299 are left on your system. You can do this by
301 Then, just double-click the WarpIN self-installing archive, which will guide
302 you through the installation process. A shadow of the Privoxy executable will
303 be placed in your startup folder so it will start automatically whenever OS/2
306 The directory you choose to install Privoxy into will contain all of the
309 -------------------------------------------------------------------------------
313 Unzip the downloaded package (you can either double-click on the file in the
314 finder, or on the desktop if you downloaded it there). Then, double-click on
315 the package installer icon and follow the installation process. Privoxy will be
316 installed in the subdirectory /Applications/Privoxy.app. Privoxy will set
317 itself up to start automatically on system bring-up via /System/Library/
318 StartupItems/Privoxy.
320 -------------------------------------------------------------------------------
324 Copy and then unpack the lha archive to a suitable location. All necessary
325 files will be installed into Privoxy directory, including all configuration and
326 log files. To uninstall, just remove this directory.
328 Start Privoxy (with RUN <>NIL:) in your startnet script (AmiTCP), in s:
329 user-startup (RoadShow), as startup program in your startup script (Genesis),
330 or as startup action (Miami and MiamiDx). Privoxy will automatically quit when
331 you quit your TCP/IP stack (just ignore the harmless warning your TCP/IP stack
332 may display that Privoxy is still running).
334 -------------------------------------------------------------------------------
336 2.2. Building from Source
338 The most convenient way to obtain the Privoxy sources is to download the source
339 tarball from our project page.
341 If you like to live on the bleeding edge and are not afraid of using possibly
342 unstable development versions, you can check out the up-to-the-minute version
343 directly from the CVS repository or simply download the nightly CVS tarball.
345 To build Privoxy from source, autoconf, GNU make (gmake), and, of course, a C
346 compiler like gcc are required.
348 When building from a source tarball (either release version or nightly CVS
349 tarball), first unpack the source:
351 tar xzvf privoxy-2.9.15-beta-src* [.tgz or .tar.gz]
352 cd privoxy-2.9.15-beta
354 For retrieving the current CVS sources, you'll need CVS installed. Note that
355 sources from CVS are development quality, and may not be stable, or well
356 tested. To download CVS source:
358 cvs -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa login
359 cvs -z3 -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa co current
362 This will create a directory named current/, which will contain the source
365 Then, in either case, to build from unpacked tarball or CVS source:
369 ./configure # (--help to see options)
370 make # (the make from gnu, gmake for *BSD)
372 make -n install # (to see where all the files will go)
373 make install # (to really install)
375 If you have gnu make, you can have the first four steps automatically done for
380 in the freshly downloaded or unpacked source directory.
382 For more detailed instructions on how to build Redhat and SuSE RPMs, Windows
383 self-extracting installers, building on platforms with special requirements
384 etc, please consult the developer manual.
386 -------------------------------------------------------------------------------
390 There are very significant changes from earlier Junkbuster versions to the
391 current Privoxy. The number, names, syntax, and purposes of configuration files
392 have substantially changed. Junkbuster 2.0.x configuration files will not
393 migrate, Junkbuster 2.9.x and Privoxy configurations will need to be ported.
394 The functionalities of the old blockfile, cookiefile and imagelist are now
395 combined into the "actions files". default.action, is the main actions file.
396 Local exceptions should best be put into user.action.
398 A "filter file" (typically default.filter) is new as of Privoxy 2.9.x, and
399 provides some of the new sophistication (explained below). config is much the
402 If upgrading from a 2.0.x version, you will have to use the new config files,
403 and possibly adapt any personal rules from your older files. When porting
404 personal rules over from the old blockfile to the new actions files, please
405 note that even the pattern syntax has changed. If upgrading from 2.9.x
406 development versions, it is still recommended to use the new configuration
409 A quick list of things to be aware of before upgrading:
411 * The default listening port is now 8118 due to a conflict with another
414 * Some installers may remove earlier versions completely. Save any important
417 * Privoxy is controllable with a web browser at the special URL: http://
418 config.privoxy.org/ (Shortcut: http://p.p/). Many aspects of configuration
419 can be done here, including temporarily disabling Privoxy.
421 * The primary configuration files for cookie management, ad and banner
422 blocking, and many other aspects of Privoxy configuration are the actions
423 files. It is strongly recommended to become familiar with the new actions
424 concept below, before modifying these files. Locally defined rules should
427 * Some installers may not automatically start Privoxy after installation.
429 -------------------------------------------------------------------------------
431 4. Quickstart to Using Privoxy
433 * If upgrading, from versions before 2.9.16, please back up any configuration
434 files. See the Note to Upgraders Section.
436 * Install Privoxy. See the Installation Section below for platform specific
439 * Advanced users and those who want to offer Privoxy service to more than
440 just their local machine should check the main config file, especially the
441 security-relevant options. These are off by default.
443 * Start Privoxy, if the installation program has not done this already (may
444 vary according to platform). See the section Starting Privoxy.
446 * Set your browser to use Privoxy as HTTP and HTTPS proxy by setting the
447 proxy configuration for address of 127.0.0.1 and port 8118. (Junkbuster and
448 earlier versions of Privoxy used port 8000.) See the section Starting
449 Privoxy below for more details on this.
451 * Flush your browser's disk and memory caches, to remove any cached ad
454 * A default installation should provide a reasonable starting point for most.
455 There will undoubtedly be occasions where you will want to adjust the
456 configuration, but that can be dealt with as the need arises. Little to no
457 initial configuration is required in most cases.
459 See the Configuration section for more configuration options, and how to
460 customize your installation.
462 * If you experience ads that slipped through, innocent images that are
463 blocked, or otherwise feel the need to fine-tune Privoxy's behaviour, take
464 a look at the actions files. As a quick start, you might find the richly
465 commented examples helpful. You can also view and edit the actions files
466 through the web-based user interface. The Appendix "Anatomy of an Action"
467 has hints how to debug actions that "misbehave".
469 * Please see the section Contacting the Developers on how to report bugs or
470 problems with websites or to get help.
472 * Now enjoy surfing with enhanced comfort and privacy!
474 -------------------------------------------------------------------------------
476 4.1. Quickstart to Ad Blocking
478 Ad blocking is but one of Privoxy's array of features. Many of these features
479 are for the technically minded advanced user. But, ad and banner blocking is
480 surely common ground for everybody.
482 This section will provide a quick summary of ad blocking so you can get up to
483 speed quickly without having to read the more extensive information provided
484 below, though this is highly recommeneded.
486 First a bit of a warning ... blocking ads is much like blocking SPAM: the more
487 aggressive you are about it, the more likely you are to block things that were
488 not intended. So there is a trade off here. If you want extreme ad free
489 browsing, be prepared to deal with more "problem" sites, and to spend more time
490 adjusting the configuration to solve these unintended consequences. In short,
491 there is not an easy way to eliminate all ads. Either take the easy way and
492 settle for most ads blocked with the default configuration, or jump in and
493 tweak it for your personal surfing habits and preferences.
495 Secondly, a brief explanation of Privoxy's "actions". "Actions" in this
496 context, are the directives we use to tell Privoxy to perform some task
497 relating to HTTP transactions (i.e. web browsing). We tell Privoxy to take some
498 "action". Each action has a unique name and function. While there are many
499 potential actions in Privoxy's arsenal, only a few are used for ad blocking.
500 Actions, and action configuration files, are explained in depth below.
502 Actions are specified in Privoxy's configuration, followed by one or more URLs
503 to which the action should apply. URLs can actually be URL type patterns that
504 use wildcards so they can apply potentially to a range of similar URLs.
506 When you connect to a website, the full path of the URL will either match one
507 of the "actions" as defined in Privoxy's configuration, or not. If so, then
508 Privoxy will perform the action accordingly. If not, then nothing special
509 happens. Futhermore, web pages may contain embedded, secondary URLs that your
510 web browser will display as it parses the original page's HTML content. An ad
511 image for instance, is just a URL embedded in the page somewhere. The image
512 itself may be on the same server, or a server somewhere else on the Internet.
513 Complex web pages will have many such embedded URLs.
515 The actions we need to know about for ad blocking are: block, handle-as-image,
516 and set-image-blocker:
518 * block - this action stops any contact between your browser and any URL
519 patterns that match this action's configuration. It can be used for
520 blocking ads, but also anything that is determined to be unwanted. By
521 itself, it simply stops any communication with the remote server. If this
522 is the only action that matches for this particular URL, then Privoxy will
523 display its own BLOCKED page to let you now what has happened.
525 * handle-as-image - forces Privoxy to treat this URL as if it were an image.
526 Privoxy knows about common image types (e.g. GIF), but there are many
527 situations where this does not apply. So we'll force it. This is
528 particularly important for ad blocking, since once we can treat it as an
529 image, we can make more intelligent decisisions on how to handle it. There
530 are some limitations to this though. For instance, you can't just force an
531 image substituion for an entire HTML page in most situations.
533 * set-image-blocker - tells Privoxy what to display in place of an ad image
534 that has hit a block rule. For this to come into play, the URL must match a
535 block action somewhere in the configuration. And, it must also either be of
536 a known image type, or match an handle-as-image action.
538 The configuration options on what to display instead of the ad are:
540 pattern - a checkboard pattern, so that an ad replacement is obvious.
543 blank - A very small empty GIF image is displayed. This is the so-called
544 "invisible" configuration option.
546 http://<URL> - A redirect to any URL of the user's choosing (advanced
549 The quickest way to adjust any of these settings is with your browser through
550 the special Privoxy editor at http://config.privoxy.org/show-status (shortcut:
551 http://p.p/show-status). This is an internal page, and does not require
552 Internet access. Select the appropriate "actions" file, and click "Edit". It is
553 best to put personal or local preferences in user.action since this is not
554 meant to be overwritten during upgrades, and will over-ride the settings in
555 other files. Here you can insert new "actions", and URLs for ad blocking or
556 other purposes, and make other adjustments to the configuration. Privoxy will
557 detect these changes automatically.
559 A quick and simple step by step example:
561 * Right click on the ad image to be blocked, then select "Copy Link Location"
562 from the pop-up menu.
564 * Set your browser to http://config.privoxy.org/show-status
566 * Find user.action in the top section, and click on "Edit":
568 Figure 1. Actions Files in Use
570 Screenshot of Files in Use
572 * You should have an Actions section labeled +block. If not, click the "Edit"
573 button just under the word "Actions". This will bring up a list of all
574 actions. Find block near the top, and click in the "Enabled" column, then
575 "Submit" just below the list.
577 * Now, in the +block actions section, click the "Add" button, and paste the
578 URL the browser got from "Copy Link Location". Remove the http:// at the
579 beginning of the URL. Then, click "Submit".
581 * Now go back to the original page, and press SHIFT-Reload (or flush all
582 browser caches). The image should be gone now.
584 This is a very crude and simple example. There might be good reasons to use a
585 wildcard pattern match to include potentially similar images from the same
586 site. For a more extensive explanation of "patterns", and the entire actions
587 concept, see the Actions section.
589 For advanced users who want to hand edit their config files, you might want to
590 now go to the Actions Files Tutorial.
592 -------------------------------------------------------------------------------
596 Before launching Privoxy for the first time, you will want to configure your
597 browser(s) to use Privoxy as a HTTP and HTTPS proxy. The default is 127.0.0.1
598 (or localhost) for the proxy address, and port 8118 (earlier versions used port
599 8000). This is the one configuration step that must be done!
601 With Netscape (and Mozilla), this can be set under Edit -> Preferences ->
602 Advanced -> Proxies -> HTTP Proxy. For Internet Explorer: Tools -> Internet
603 Properties -> Connections -> LAN Setting. Then, check "Use Proxy" and fill in
604 the appropriate info (Address: 127.0.0.1, Port: 8118). Include if HTTPS proxy
607 After doing this, flush your browser's disk and memory caches to force a
608 re-reading of all pages and to get rid of any ads that may be cached. You are
609 now ready to start enjoying the benefits of using Privoxy!
611 Privoxy is typically started by specifying the main configuration file to be
612 used on the command line. If no configuration file is specified on the command
613 line, Privoxy will look for a file named config in the current directory.
614 Except on Win32 where it will try config.txt.
616 -------------------------------------------------------------------------------
618 5.1. RedHat, Conectiva and Debian
620 We use a script. Note that RedHat does not start Privoxy upon booting per
621 default. It will use the file /etc/privoxy/config as its main configuration
622 file. FIXME: Debian??
624 # /etc/rc.d/init.d/privoxy start
626 -------------------------------------------------------------------------------
630 We use a script. It will use the file /etc/privoxy/config as its main
631 configuration file. Note that SuSE starts Privoxy upon booting your PC.
635 -------------------------------------------------------------------------------
639 Click on the Privoxy Icon to start Privoxy. If no configuration file is
640 specified on the command line, Privoxy will look for a file named config.txt.
641 Note that Windows will automatically start Privoxy upon booting you PC.
643 -------------------------------------------------------------------------------
645 5.4. Solaris, NetBSD, FreeBSD, HP-UX and others
647 Example Unix startup command:
649 # /usr/sbin/privoxy /etc/privoxy/config
651 -------------------------------------------------------------------------------
657 -------------------------------------------------------------------------------
663 -------------------------------------------------------------------------------
669 -------------------------------------------------------------------------------
671 5.8. Command Line Options
673 Privoxy may be invoked with the following command-line options:
677 Print version info and exit. Unix only.
681 Print short usage info and exit. Unix only.
685 Don't become a daemon, i.e. don't fork and become process group leader, and
686 don't detach from controlling tty. Unix only.
690 On startup, write the process ID to FILE. Delete the FILE on exit. Failure
691 to create or delete the FILE is non-fatal. If no FILE option is given, no
692 PID file will be used. Unix only.
694 * --user USER[.GROUP]
696 After (optionally) writing the PID file, assume the user ID of USER, and if
697 included the GID of GROUP. Exit if the privileges are not sufficient to do
702 If no configfile is included on the command line, Privoxy will look for a
703 file named "config" in the current directory (except on Win32 where it will
704 look for "config.txt" instead). Specify full path to avoid confusion. If no
705 config file is found, Privoxy will fail to start.
707 -------------------------------------------------------------------------------
709 6. Privoxy Configuration
711 All Privoxy configuration is stored in text files. These files can be edited
712 with a text editor. Many important aspects of Privoxy can also be controlled
713 easily with a web browser.
715 -------------------------------------------------------------------------------
717 6.1. Controlling Privoxy with Your Web Browser
719 Privoxy's user interface can be reached through the special URL http://
720 config.privoxy.org/ (shortcut: http://p.p/), which is a built-in page and works
721 without Internet access. You will see the following section:
724 ? View & change the current configuration
725 ? View the source code version numbers
726 ? View the request headers.
727 ? Look up which actions apply to a URL and why
728 ? Toggle Privoxy on or off
731 This should be self-explanatory. Note the first item leads to an editor for the
732 actions files, which is where the ad, banner, cookie, and URL blocking magic is
733 configured as well as other advanced features of Privoxy. This is an easy way
734 to adjust various aspects of Privoxy configuration. The actions file, and other
735 configuration files, are explained in detail below.
737 "Toggle Privoxy On or Off" is handy for sites that might have problems with
738 your current actions and filters. You can in fact use it as a test to see
739 whether it is Privoxy causing the problem or not. Privoxy continues to run as a
740 proxy in this case, but all manipulation is disabled, i.e. Privoxy acts like a
741 normal forwarding proxy. There is even a toggle Bookmarklet offered, so that
742 you can toggle Privoxy with one click from your browser.
744 -------------------------------------------------------------------------------
746 6.2. Configuration Files Overview
748 For Unix, *BSD and Linux, all configuration files are located in /etc/privoxy/
749 by default. For MS Windows, OS/2, and AmigaOS these are all in the same
750 directory as the Privoxy executable. The name and number of configuration files
751 has changed from previous versions, and is subject to change as development
754 The installed defaults provide a reasonable starting point, though some
755 settings may be aggressive by some standards. For the time being, the principle
756 configuration files are:
758 * The main configuration file is named config on Linux, Unix, BSD, OS/2, and
759 AmigaOS and config.txt on Windows. This is a required file.
761 * default.action (the main actions file) is used to define which "actions"
762 relating to banner-blocking, images, pop-ups, content modification, cookie
763 handling etc should be applied by default. It also defines many exceptions
764 (both positive and negative) from this default set of actions that enable
765 Privoxy to selectively eliminate the junk, and only the junk, on as many
766 websites as possible.
768 Multiple actions files may be defined in config. These are processed in the
769 order they are defined. Local customizations and locally preferred
770 exceptions to the default policies as defined in default.action (which you
771 will most probably want to define sooner or later) are probably best
772 applied in user.action, where you can preserve them across upgrades.
773 standard.action is for Privoxy's internal use.
775 There is also a web based editor that can be accessed from http://
776 config.privoxy.org/show-status (Shortcut: http://p.p/show-status) for the
777 various actions files.
779 * default.filter (the filter file) can be used to re-write the raw page
780 content, including viewable text as well as embedded HTML and JavaScript,
781 and whatever else lurks on any given web page. The filtering jobs are only
782 pre-defined here; whether to apply them or not is up to the actions files.
784 All files use the "#" character to denote a comment (the rest of the line will
785 be ignored) and understand line continuation through placing a backslash ("\")
786 as the very last character in a line. If the # is preceded by a backslash, it
787 looses its special function. Placing a # in front of an otherwise valid
788 configuration line to prevent it from being interpreted is called "commenting
791 The actions files and default.filter can use Perl style regular expressions for
794 After making any changes, there is no need to restart Privoxy in order for the
795 changes to take effect. Privoxy detects such changes automatically. Note,
796 however, that it may take one or two additional requests for the change to take
797 effect. When changing the listening address of Privoxy, these "wake up"
798 requests must obviously be sent to the old listening address.
800 While under development, the configuration content is subject to change. The
801 below documentation may not be accurate by the time you read this. Also, what
802 constitutes a "default" setting, may change, so please check all your
803 configuration files on important issues.
805 -------------------------------------------------------------------------------
807 7. The Main Configuration File
809 Again, the main configuration file is named config on Linux/Unix/BSD and OS/2,
810 and config.txt on Windows. Configuration lines consist of an initial keyword
811 followed by a list of values, all separated by whitespace (any number of spaces
812 or tabs). For example:
816 Assigns the value /etc/privoxy to the option confdir and thus indicates that
817 the configuration directory is named "/etc/privoxy/".
819 All options in the config file except for confdir and logdir are optional.
820 Watch out in the below description for what happens if you leave them unset.
822 The main config file controls all aspects of Privoxy's operation that are not
823 location dependent (i.e. they apply universally, no matter where you may be
826 -------------------------------------------------------------------------------
828 7.1. Configuration and Log File Locations
830 Privoxy can (and normally does) use a number of other files for additional
831 configuration, help and logging. This section of the configuration file tells
832 Privoxy where to find those other files.
834 The user running Privoxy, must have read permission for all configuration
835 files, and write permission to any files that would be modified, such as log
838 -------------------------------------------------------------------------------
844 The directory where the other configuration files are located
852 /etc/privoxy (Unix) or Privoxy installation dir (Windows)
860 No trailing "/", please
862 When development goes modular and multi-user, the blocker, filter, and
863 per-user config will be stored in subdirectories of "confdir". For now, the
864 configuration directory structure is flat, except for confdir/templates,
865 where the HTML templates for CGI output reside (e.g. Privoxy's 404 error
868 -------------------------------------------------------------------------------
874 The directory where all logging takes place (i.e. where logfile and jarfile
883 /var/log/privoxy (Unix) or Privoxy installation dir (Windows)
891 No trailing "/", please
893 -------------------------------------------------------------------------------
899 The actions file(s) to use
903 File name, relative to confdir, without the .action suffix
907 standard # Internal purposes, no editing recommended
909 default # Main actions file
911 user # User customizations
915 No actions are taken at all. Simple neutral proxying.
919 Multiple actionsfile lines are permitted, and are in fact recommended!
921 The default values include standard.action, which is used for internal
922 purposes and should be loaded, default.action, which is the "main" actions
923 file maintained by the developers, and user.action, where you can make your
926 Actions files are where all the per site and per URL configuration is done
927 for ad blocking, cookie management, privacy considerations, etc. There is
928 no point in using Privoxy without at least one actions file.
930 -------------------------------------------------------------------------------
936 The filter file to use
940 File name, relative to confdir
944 default.filter (Unix) or default.filter.txt (Windows)
948 No textual content filtering takes place, i.e. all +filter{name} actions in
949 the actions files are turned neutral.
953 The filter file contains content modification rules that use regular
954 expressions. These rules permit powerful changes on the content of Web
955 pages, e.g., you could disable your favorite JavaScript annoyances,
956 re-write the actual displayed text, or just have some fun replacing
957 "Microsoft" with "MicroSuck" wherever it appears on a Web page.
959 The +filter{name} actions rely on the relevant filter (name) to be defined
962 A pre-defined filter file called default.filter that contains a bunch of
963 handy filters for common problems is included in the distribution. See the
964 section on the filter action for a list.
966 -------------------------------------------------------------------------------
976 File name, relative to logdir
980 logfile (Unix) or privoxy.log (Windows)
984 No log file is used, all log messages go to the console (stderr).
988 The windows version will additionally log to the console.
990 The logfile is where all logging and error messages are written. The level
991 of detail and number of messages are set with the debug option (see below).
992 The logfile can be useful for tracking down a problem with Privoxy (e.g.,
993 it's not blocking an ad you think it should block) but in most cases you
994 probably will never look at it.
996 Your logfile will grow indefinitely, and you will probably want to
997 periodically remove it. On Unix systems, you can do this with a cron job
998 (see "man cron"). For Red Hat, a logrotate script has been included.
1000 On SuSE Linux systems, you can place a line like "/var/log/privoxy.* +1024k
1001 644 nobody.nogroup" in /etc/logfiles, with the effect that cron.daily will
1002 automatically archive, gzip, and empty the log, when it exceeds 1M size.
1004 Any log files must be writable by whatever user Privoxy is being run as
1005 (default on UNIX, user id is "privoxy").
1007 -------------------------------------------------------------------------------
1013 The file to store intercepted cookies in
1017 File name, relative to logdir
1021 jarfile (Unix) or privoxy.jar (Windows)
1025 Intercepted cookies are not stored at all.
1029 The jarfile may grow to ridiculous sizes over time.
1031 -------------------------------------------------------------------------------
1037 The trust file to use
1041 File name, relative to confdir
1045 Unset (commented out). When activated: trust (Unix) or trust.txt (Windows)
1049 The whole trust mechanism is turned off.
1053 The trust mechanism is an experimental feature for building white-lists and
1054 should be used with care. It is NOT recommended for the casual user.
1056 If you specify a trust file, Privoxy will only allow access to sites that
1057 are named in the trustfile. You can also mark sites as trusted referrers
1058 (with +), with the effect that access to untrusted sites will be granted,
1059 if a link from a trusted referrer was used. The link target will then be
1060 added to the "trustfile". Possible applications include limiting Internet
1061 access for children.
1063 If you use + operator in the trust file, it may grow considerably over
1066 -------------------------------------------------------------------------------
1068 7.2. Local Set-up Documentation
1070 If you intend to operate Privoxy for more users than just yourself, it might be
1071 a good idea to let them know how to reach you, what you block and why you do
1072 that, your policies, etc.
1074 -------------------------------------------------------------------------------
1080 Location of the Privoxy User Manual.
1084 A fully qualified URI
1092 http://www.privoxy.org/version/user-manual/ will be used, where version is
1093 the Privoxy version.
1097 The User Manual URI is used for help links from some of the internal CGI
1098 pages. The manual itself is normally packaged with the binary
1099 distributions, so you probably want to set this to a locally installed
1100 copy. For multi-user setups, you could provide a copy on a local webserver
1101 for all your users and use the corresponding URL here.
1105 Unix, in local filesystem:
1107 user-manual file:///usr/share/doc/privoxy-2.9.15/user-manual/
1109 Any platform, on local webserver (called "local-webserver"):
1111 user-manual http://local-webserver/privoxy-user-manual/
1113 +-----------------------------------------------------------------+
1115 |-----------------------------------------------------------------|
1116 |If set, this option should be the first option in the config |
1117 |file, because it is used while the config file is being read. |
1118 +-----------------------------------------------------------------+
1120 -------------------------------------------------------------------------------
1122 7.2.2. trust-info-url
1126 A URL to be displayed in the error page that users will see if access to an
1127 untrusted page is denied.
1135 Two example URL are provided
1139 No links are displayed on the "untrusted" error page.
1143 The value of this option only matters if the experimental trust mechanism
1144 has been activated. (See trustfile above.)
1146 If you use the trust mechanism, it is a good idea to write up some on-line
1147 documentation about your trust policy and to specify the URL(s) here. Use
1148 multiple times for multiple URLs.
1150 The URL(s) should be added to the trustfile as well, so users don't end up
1151 locked out from the information on why they were locked out in the first
1154 -------------------------------------------------------------------------------
1156 7.2.3. admin-address
1160 An email address to reach the proxy administrator.
1172 No email address is displayed on error pages and the CGI user interface.
1176 If both admin-address and proxy-info-url are unset, the whole "Local
1177 Privoxy Support" box on all generated pages will not be shown.
1179 -------------------------------------------------------------------------------
1181 7.2.4. proxy-info-url
1185 A URL to documentation about the local Privoxy setup, configuration or
1198 No link to local documentation is displayed on error pages and the CGI user
1203 If both admin-address and proxy-info-url are unset, the whole "Local
1204 Privoxy Support" box on all generated pages will not be shown.
1206 This URL shouldn't be blocked ;-)
1208 -------------------------------------------------------------------------------
1212 These options are mainly useful when tracing a problem. Note that you might
1213 also want to invoke Privoxy with the --no-daemon command line option when
1216 -------------------------------------------------------------------------------
1222 Key values that determine what information gets logged to the logfile.
1230 12289 (i.e.: URLs plus informational and warning messages)
1234 Nothing gets logged.
1238 The available debug levels are:
1240 debug 1 # show each GET/POST/CONNECT request
1241 debug 2 # show each connection status
1242 debug 4 # show I/O status
1243 debug 8 # show header parsing
1244 debug 16 # log all data into the logfile
1245 debug 32 # debug force feature
1246 debug 64 # debug regular expression filter
1247 debug 128 # debug fast redirects
1248 debug 256 # debug GIF de-animation
1249 debug 512 # Common Log Format
1250 debug 1024 # debug kill pop-ups
1251 debug 4096 # Startup banner and warnings.
1252 debug 8192 # Non-fatal errors
1254 To select multiple debug levels, you can either add them or use multiple
1257 A debug level of 1 is informative because it will show you each request as
1258 it happens. 1, 4096 and 8192 are highly recommended so that you will notice
1259 when things go wrong. The other levels are probably only of interest if you
1260 are hunting down a specific problem. They can produce a hell of an output
1263 The reporting of fatal errors (i.e. ones which crash Privoxy) is always on
1264 and cannot be disabled.
1266 If you want to use CLF (Common Log Format), you should set "debug 512" ONLY
1267 and not enable anything else.
1269 -------------------------------------------------------------------------------
1271 7.3.2. single-threaded
1275 Whether to run only one server thread
1287 Multi-threaded (or, where unavailable: forked) operation, i.e. the ability
1288 to serve multiple requests simultaneously.
1292 This option is only there for debug purposes and you should never need to
1293 use it. It will drastically reduce performance.
1295 -------------------------------------------------------------------------------
1297 7.4. Access Control and Security
1299 This section of the config file controls the security-relevant aspects of
1300 Privoxy's configuration.
1302 -------------------------------------------------------------------------------
1304 7.4.1. listen-address
1308 The IP address and TCP port on which Privoxy will listen for client
1321 Bind to 127.0.0.1 (localhost), port 8118. This is suitable and recommended
1322 for home users who run Privoxy on the same machine as their browser.
1326 You will need to configure your browser(s) to this proxy address and port.
1328 If you already have another service running on port 8118, or if you want to
1329 serve requests from other machines (e.g. on your local network) as well,
1330 you will need to override the default.
1332 If you leave out the IP address, Privoxy will bind to all interfaces
1333 (addresses) on your machine and may become reachable from the Internet. In
1334 that case, consider using access control lists (ACL's) (see "ACLs" below),
1339 Suppose you are running Privoxy on a machine which has the address
1340 192.168.0.1 on your local private network (192.168.0.0) and has another
1341 outside connection with a different address. You want it to serve requests
1344 listen-address 192.168.0.1:8118
1346 -------------------------------------------------------------------------------
1352 Initial state of "toggle" status
1364 Act as if toggled on
1368 If set to 0, Privoxy will start in "toggled off" mode, i.e. behave like a
1369 normal, content-neutral proxy where all ad blocking, filtering, etc are
1370 disabled. See enable-remote-toggle below. This is not really useful
1371 anymore, since toggling is much easier via the web interface than via
1372 editing the conf file.
1374 The windows version will only display the toggle icon in the system tray if
1375 this option is present.
1377 -------------------------------------------------------------------------------
1379 7.4.3. enable-remote-toggle
1383 Whether or not the web-based toggle feature may be used
1395 The web-based toggle feature is disabled.
1399 When toggled off, Privoxy acts like a normal, content-neutral proxy, i.e.
1400 it acts as if none of the actions applied to any URL.
1402 For the time being, access to the toggle feature can not be controlled
1403 separately by "ACLs" or HTTP authentication, so that everybody who can
1404 access Privoxy (see "ACLs" and listen-address above) can toggle it for all
1405 users. So this option is not recommended for multi-user environments with
1408 Note that you must have compiled Privoxy with support for this feature,
1409 otherwise this option has no effect.
1411 -------------------------------------------------------------------------------
1413 7.4.4. enable-edit-actions
1417 Whether or not the web-based actions file editor may be used
1429 The web-based actions file editor is disabled.
1433 For the time being, access to the editor can not be controlled separately
1434 by "ACLs" or HTTP authentication, so that everybody who can access Privoxy
1435 (see "ACLs" and listen-address above) can modify its configuration for all
1436 users. So this option is not recommended for multi-user environments with
1439 Note that you must have compiled Privoxy with support for this feature,
1440 otherwise this option has no effect.
1442 -------------------------------------------------------------------------------
1444 7.4.5. ACLs: permit-access and deny-access
1448 Who can access what.
1452 src_addr[/src_masklen] [dst_addr[/dst_masklen]]
1454 Where src_addr and dst_addr are IP addresses in dotted decimal notation or
1455 valid DNS names, and src_masklen and dst_masklen are subnet masks in CIDR
1456 notation, i.e. integer values from 2 to 30 representing the length (in
1457 bits) of the network address. The masks and the whole destination part are
1466 Don't restrict access further than implied by listen-address
1470 Access controls are included at the request of ISPs and systems
1471 administrators, and are not usually needed by individual users. For a
1472 typical home user, it will normally suffice to ensure that Privoxy only
1473 listens on the localhost (127.0.0.1) or internal (home) network address by
1474 means of the listen-address option.
1476 Please see the warnings in the FAQ that this proxy is not intended to be a
1477 substitute for a firewall or to encourage anyone to defer addressing basic
1478 security weaknesses.
1480 Multiple ACL lines are OK. If any ACLs are specified, then the Privoxy
1481 talks only to IP addresses that match at least one permit-access line and
1482 don't match any subsequent deny-access line. In other words, the last match
1483 wins, with the default being deny-access.
1485 If Privoxy is using a forwarder (see forward below) for a particular
1486 destination URL, the dst_addr that is examined is the address of the
1487 forwarder and NOT the address of the ultimate target. This is necessary
1488 because it may be impossible for the local Privoxy to determine the IP
1489 address of the ultimate target (that's often what gateways are used for).
1491 You should prefer using IP addresses over DNS names, because the address
1492 lookups take time. All DNS names must resolve! You can not use domain
1493 patterns like "*.org" or partial domain names. If a DNS name resolves to
1494 multiple IP addresses, only the first one is used.
1496 Denying access to particular sites by ACL may have undesired side effects
1497 if the site in question is hosted on a machine which also hosts other
1502 Explicitly define the default behavior if no ACL and listen-address are
1503 set: "localhost" is OK. The absence of a dst_addr implies that all
1504 destination addresses are OK:
1506 permit-access localhost
1508 Allow any host on the same class C subnet as www.privoxy.org access to
1509 nothing but www.example.com:
1511 permit-access www.privoxy.org/24 www.example.com/32
1513 Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere,
1514 with the exception that 192.168.45.73 may not access
1515 www.dirty-stuff.example.com:
1517 permit-access 192.168.45.64/26
1518 deny-access 192.168.45.73 www.dirty-stuff.example.com
1520 -------------------------------------------------------------------------------
1526 Maximum size of the buffer for content filtering.
1538 Use a 4MB (4096 KB) limit.
1542 For content filtering, i.e. the +filter and +deanimate-gif actions, it is
1543 necessary that Privoxy buffers the entire document body. This can be
1544 potentially dangerous, since a server could just keep sending data
1545 indefinitely and wait for your RAM to exhaust -- with nasty consequences.
1548 When a document buffer size reaches the buffer-limit, it is flushed to the
1549 client unfiltered and no further attempt to filter the rest of the document
1550 is made. Remember that there may be multiple threads running, which might
1551 require up to buffer-limit Kbytes each, unless you have enabled
1552 "single-threaded" above.
1554 -------------------------------------------------------------------------------
1558 This feature allows routing of HTTP requests through a chain of multiple
1559 proxies. It can be used to better protect privacy and confidentiality when
1560 accessing specific domains by routing requests to those domains through an
1561 anonymous public proxy (see e.g. http://www.multiproxy.org/anon_list.htm) Or to
1562 use a caching proxy to speed up browsing. Or chaining to a parent proxy may be
1563 necessary because the machine that Privoxy runs on has no direct Internet
1566 Also specified here are SOCKS proxies. Privoxy supports the SOCKS 4 and SOCKS
1569 -------------------------------------------------------------------------------
1575 To which parent HTTP proxy specific requests should be routed.
1579 target_domain[:port] http_parent[/port]
1581 Where target_domain is a domain name pattern (see the chapter on domain
1582 matching in the default.action file), http_parent is the address of the
1583 parent HTTP proxy as an IP addresses in dotted decimal notation or as a
1584 valid DNS name (or "." to denote "no forwarding", and the optional port
1585 parameters are TCP ports, i.e. integer values from 1 to 64535
1593 Don't use parent HTTP proxies.
1597 If http_parent is ".", then requests are not forwarded to another HTTP
1598 proxy but are made directly to the web servers.
1600 Multiple lines are OK, they are checked in sequence, and the last match
1605 Everything goes to an example anonymizing proxy, except SSL on port 443
1606 (which it doesn't handle):
1608 forward .* anon-proxy.example.org:8080
1611 Everything goes to our example ISP's caching proxy, except for requests to
1614 forward .*. caching-proxy.example-isp.net:8000
1615 forward .example-isp.net .
1617 -------------------------------------------------------------------------------
1619 7.5.2. forward-socks4 and forward-socks4a
1623 Through which SOCKS proxy (and to which parent HTTP proxy) specific
1624 requests should be routed.
1628 target_domain[:port] socks_proxy[/port] http_parent[/port]
1630 Where target_domain is a domain name pattern (see the chapter on domain
1631 matching in the default.action file), http_parent and socks_proxy are IP
1632 addresses in dotted decimal notation or valid DNS names (http_parent may be
1633 "." to denote "no HTTP forwarding"), and the optional port parameters are
1634 TCP ports, i.e. integer values from 1 to 64535
1642 Don't use SOCKS proxies.
1646 Multiple lines are OK, they are checked in sequence, and the last match
1649 The difference between forward-socks4 and forward-socks4a is that in the
1650 SOCKS 4A protocol, the DNS resolution of the target hostname happens on the
1651 SOCKS server, while in SOCKS 4 it happens locally.
1653 If http_parent is ".", then requests are not forwarded to another HTTP
1654 proxy but are made (HTTP-wise) directly to the web servers, albeit through
1659 From the company example.com, direct connections are made to all "internal"
1660 domains, but everything outbound goes through their ISP's proxy by way of
1661 example.com's corporate SOCKS 4A gateway to the Internet.
1663 forward-socks4a .*. socks-gw.example.com:1080 www-cache.example-isp.net:8080
1664 forward .example.com .
1666 A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent
1669 forward-socks4 .*. socks-gw.example.com:1080 .
1671 -------------------------------------------------------------------------------
1673 7.5.3. Advanced Forwarding Examples
1675 If you have links to multiple ISPs that provide various special content only to
1676 their subscribers, you can configure multiple Privoxies which have connections
1677 to the respective ISPs to act as forwarders to each other, so that your users
1678 can see the internal content of all ISPs.
1680 Assume that host-a has a PPP connection to isp-a.net. And host-b has a PPP
1681 connection to isp-b.net. Both run Privoxy. Their forwarding configuration can
1687 forward .isp-b.net host-b:8118
1692 forward .isp-a.net host-a:8118
1694 Now, your users can set their browser's proxy to use either host-a or host-b
1695 and be able to browse the internal content of both isp-a and isp-b.
1697 If you intend to chain Privoxy and squid locally, then chain as browser ->
1698 squid -> privoxy is the recommended way.
1700 Assuming that Privoxy and squid run on the same box, your squid configuration
1701 could then look like this:
1703 # Define Privoxy as parent proxy (without ICP)
1704 cache_peer 127.0.0.1 parent 8118 7 no-query
1706 # Define ACL for protocol FTP
1709 # Do not forward FTP requests to Privoxy
1710 always_direct allow ftp
1712 # Forward all the rest to Privoxy
1713 never_direct allow all
1715 You would then need to change your browser's proxy settings to squid's address
1716 and port. Squid normally uses port 3128. If unsure consult http_port in
1719 -------------------------------------------------------------------------------
1721 7.6. Windows GUI Options
1723 Privoxy has a number of options specific to the Windows GUI interface:
1725 If "activity-animation" is set to 1, the Privoxy icon will animate when
1726 "Privoxy" is active. To turn off, set to 0.
1728 activity-animation 1
1731 If "log-messages" is set to 1, Privoxy will log messages to the console window:
1736 If "log-buffer-size" is set to 1, the size of the log buffer, i.e. the amount
1737 of memory used for the log messages displayed in the console window, will be
1738 limited to "log-max-lines" (see below).
1740 Warning: Setting this to 0 will result in the buffer to grow infinitely and eat
1746 log-max-lines is the maximum number of lines held in the log buffer. See above.
1751 If "log-highlight-messages" is set to 1, Privoxy will highlight portions of the
1752 log messages with a bold-faced font:
1754 log-highlight-messages 1
1757 The font used in the console window:
1759 log-font-name Comic Sans MS
1762 Font size used in the console window:
1767 "show-on-task-bar" controls whether or not Privoxy will appear as a button on
1768 the Task bar when minimized:
1773 If "close-button-minimizes" is set to 1, the Windows close button will minimize
1774 Privoxy instead of closing the program (close with the exit option on the File
1777 close-button-minimizes 1
1780 The "hide-console" option is specific to the MS-Win console version of Privoxy.
1781 If this option is used, Privoxy will disconnect from and hide the command
1787 -------------------------------------------------------------------------------
1791 The actions files are used to define what actions Privoxy takes for which URLs,
1792 and thus determine how ad images, cookies and various other aspects of HTTP
1793 content and transactions are handled, and on which sites (or even parts
1794 thereof). There are three such files included with Privoxy (as of version
1795 2.9.15), with differing purposes:
1797 * default.action - is the primary action file that sets the initial values
1798 for all actions. It is intended to provide a base level of functionality
1799 for Privoxy's array of features. So it is a set of broad rules that should
1800 work reasonably well for users everywhere. This is the file that the
1801 developers are keeping updated, and making available to users.
1803 * user.action - is intended to be for local site preferences and exceptions.
1804 As an example, if your ISP or your bank has specific requirements, and need
1805 special handling, this kind of thing should go here. This file will not be
1808 * standard.action - is used by the web based editor, to set various
1809 pre-defined sets of rules for the default actions section in
1810 default.action. These have increasing levels of aggressiveness and have no
1811 influence on your browsing unless you select them explicitly in the editor.
1812 It is not recommend to edit this file.
1814 The list of actions files to be used are defined in the main configuration
1815 file, and are processed in the order they are defined. The content of these can
1816 all be viewed and edited from http://config.privoxy.org/show-status.
1818 An actions file typically has multiple sections. If you want to use "aliases"
1819 in an actions file, you have to place the (optional) alias section at the top
1820 of that file. Then comes the default set of rules which will apply universally
1821 to all sites and pages (be very careful with using such a universal set in
1822 user.action or any other actions file after default.action, because it will
1823 override the result from consulting any previous file). And then below that,
1824 exceptions to the defined universal policies. You can regard user.action as an
1825 appendix to default.action, with the advantage that is a separate file, which
1826 makes preserving your personal settings across Privoxy upgrades easier.
1828 Actions can be used to block anything you want, including ads, banners, or just
1829 some obnoxious URL that you would rather not see. Cookies can be accepted or
1830 rejected, or accepted only during the current browser session (i.e. not written
1831 to disk), content can be modified, JavaScripts tamed, user-tracking fooled, and
1832 much more. See below for a complete list of actions.
1834 -------------------------------------------------------------------------------
1836 8.1. Finding the Right Mix
1838 Note that some actions, like cookie suppression or script disabling, may render
1839 some sites unusable that rely on these techniques to work properly. Finding the
1840 right mix of actions is not always easy and certainly a matter of personal
1841 taste. In general, it can be said that the more "aggressive" your default
1842 settings (in the top section of the actions file) are, the more exceptions for
1843 "trusted" sites you will have to make later. If, for example, you want to kill
1844 popup windows per default, you'll have to make exceptions from that rule for
1845 sites that you regularly use and that require popups for actually useful
1846 content, like maybe your bank, favorite shop, or newspaper.
1848 We have tried to provide you with reasonable rules to start from in the
1849 distribution actions files. But there is no general rule of thumb on these
1850 things. There just are too many variables, and sites are constantly changing.
1851 Sooner or later you will want to change the rules (and read this chapter again
1854 -------------------------------------------------------------------------------
1858 The easiest way to edit the actions files is with a browser by using our
1859 browser-based editor, which can be reached from http://config.privoxy.org/
1860 show-status. The editor allows both fine-grained control over every single
1861 feature on a per-URL basis, and easy choosing from wholesale sets of defaults
1862 like "Cautious", "Medium" or "Advanced".
1864 If you prefer plain text editing to GUIs, you can of course also directly edit
1865 the the actions files. Look at default.action which is richly commented.
1867 -------------------------------------------------------------------------------
1869 8.3. How Actions are Applied to URLs
1871 Actions files are divided into sections. There are special sections, like the "
1872 alias" sections which will be discussed later. For now let's concentrate on
1873 regular sections: They have a heading line (often split up to multiple lines
1874 for readability) which consist of a list of actions, separated by whitespace
1875 and enclosed in curly braces. Below that, there is a list of URL patterns, each
1878 To determine which actions apply to a request, the URL of the request is
1879 compared to all patterns in each action file file. Every time it matches, the
1880 list of applicable actions for the URL is incrementally updated, using the
1881 heading of the section in which the pattern is located. If multiple matches for
1882 the same URL set the same action differently, the last match wins. If not, the
1883 effects are aggregated (e.g. a URL might match both the "+handle-as-image" and
1886 You can trace this process for any given URL by visiting http://
1887 config.privoxy.org/show-url-info.
1889 More detail on this is provided in the Appendix, Anatomy of an Action.
1891 -------------------------------------------------------------------------------
1895 Generally, a pattern has the form <domain>/<path>, where both the <domain> and
1896 <path> are optional. (This is why the pattern / matches all URLs).
1900 is a domain-only pattern and will match any request to www.example.com,
1901 regardless of which document on that server is requested.
1905 means exactly the same. For domain-only patterns, the trailing / may be
1908 www.example.com/index.html
1910 matches only the single document /index.html on www.example.com.
1914 matches the document /index.html, regardless of the domain, i.e. on any web
1919 matches nothing, since it would be interpreted as a domain name and there
1920 is no top-level domain called .html.
1922 -------------------------------------------------------------------------------
1924 8.4.1. The Domain Pattern
1926 The matching of the domain part offers some flexible options: if the domain
1927 starts or ends with a dot, it becomes unanchored at that end. For example:
1931 matches any domain that ENDS in .example.com
1935 matches any domain that STARTS with www.
1939 matches any domain that CONTAINS .example. (Correctly speaking: It matches
1940 any FQDN that contains example as a domain.)
1942 Additionally, there are wild-cards that you can use in the domain names
1943 themselves. They work pretty similar to shell wild-cards: "*" stands for zero
1944 or more arbitrary characters, "?" stands for any single character, you can
1945 define character classes in square brackets and all of that can be freely
1950 matches "adserver.example.com", "ads.example.com", etc but not
1955 matches all of the above, and then some.
1959 matches www.ipix.com, pictures.epix.com, a.b.c.d.e.upix.com etc.
1961 www[1-9a-ez].example.c*
1963 matches www1.example.com, www4.example.cc, wwwd.example.cy,
1964 wwwz.example.com etc., but not wwww.example.com.
1966 -------------------------------------------------------------------------------
1968 8.4.2. The Path Pattern
1970 Privoxy uses Perl compatible regular expressions (through the PCRE library) for
1973 There is an Appendix with a brief quick-start into regular expressions, and
1974 full (very technical) documentation on PCRE regex syntax is available on-line
1975 at http://www.pcre.org/man.txt. You might also find the Perl man page on
1976 regular expressions (man perlre) useful, which is available on-line at http://
1977 www.perldoc.com/perl5.6/pod/perlre.html.
1979 Note that the path pattern is automatically left-anchored at the "/", i.e. it
1980 matches as if it would start with a "^" (regular expression speak for the
1981 beginning of a line).
1983 Please also note that matching in the path is case INSENSITIVE by default, but
1984 you can switch to case sensitive at any point in the pattern by using the "(?
1985 -i)" switch: www.example.com/(?-i)PaTtErN.* will match only documents whose
1986 path starts with PaTtErN in exactly this capitalization.
1988 -------------------------------------------------------------------------------
1992 All actions are disabled by default, until they are explicitly enabled
1993 somewhere in an actions file. Actions are turned on if preceded with a "+", and
1994 turned off if preceded with a "-". So a +action means "do that action", e.g.
1995 +block means "please block URLs that match the following patterns", and -block
1996 means "don't block URLs that match the following patterns, even if +block
1997 previously applied."
1999 Again, actions are invoked by placing them on a line, enclosed in curly braces
2000 and separated by whitespace, like in {+some-action -some-other-action
2001 {some-parameter}}, followed by a list of URL patterns, one per line, to which
2002 they apply. Together, the actions line and the following pattern lines make up
2003 a section of the actions file.
2005 There are three classes of actions:
2007 * Boolean, i.e the action can only be "enabled" or "disabled". Syntax:
2009 +name # enable action name
2010 -name # disable action name
2014 * Parameterized, where some value is required in order to enable this type of
2017 +name{param} # enable action and set parameter to param,
2018 # overwriting parameter from previous match if necessary
2019 -name # disable action. The parameter can be omitted
2021 Note that if the URL matches multiple positive forms of a parameterized
2022 action, the last match wins, i.e. the params from earlier matches are
2025 Example: +hide-user-agent{ Mozilla 1.0 }
2027 * Multi-value. These look exactly like parameterized actions, but they behave
2028 differently: If the action applies multiple times to the same URL, but with
2029 different parameters, all the parameters from all matches are remembered.
2030 This is used for actions that can be executed for the same request
2031 repeatedly, like adding multiple headers, or filtering through multiple
2034 +name{param} # enable action and add param to the list of parameters
2035 -name{param} # remove the parameter param from the list of parameters
2036 # If it was the last one left, disable the action.
2037 -name # disable this action completely and remove all parameters from the list
2039 Examples: +add-header{X-Fun-Header: Some text} and +filter{html-annoyances}
2041 If nothing is specified in any actions file, no "actions" are taken. So in this
2042 case Privoxy would just be a normal, non-blocking, non-anonymizing proxy. You
2043 must specifically enable the privacy and blocking features you need (although
2044 the provided default actions files will give a good starting point).
2046 Later defined actions always over-ride earlier ones. So exceptions to any rules
2047 you make, should come in the latter part of the file (or in a file that is
2048 processed later when using multiple actions files). For multi-valued actions,
2049 the actions are applied in the order they are specified. Actions files are
2050 processed in the order they are defined in config (the default installation has
2051 three actions files). It also quite possible for any given URL pattern to match
2052 more than one pattern and thus more than one set of actions!
2054 The list of valid Privoxy actions are:
2056 -------------------------------------------------------------------------------
2062 Confuse log analysis, custom applications
2066 Sends a user defined HTTP header to the web server.
2074 Any string value is possible. Validity of the defined HTTP headers is not
2075 checked. It is recommended that you use the "X-" prefix for custom headers.
2079 This action may be specified multiple times, in order to define multiple
2080 headers. This is rarely needed for the typical user. If you don't know what
2081 "HTTP headers" are, you definitely don't need to worry about this one.
2085 +add-header{X-User-Tracking: sucks}
2087 -------------------------------------------------------------------------------
2093 Block ads or other obnoxious content
2097 Requests for URLs to which this action applies are blocked, i.e. the
2098 requests are not forwarded to the remote server, but answered locally with
2099 a substitute page or image, as determined by the handle-as-image and
2100 set-image-blocker actions.
2112 Privoxy sends a special "BLOCKED" page for requests to blocked pages. This
2113 page contains links to find out why the request was blocked, and a
2114 click-through to the blocked content (the latter only if compiled with the
2115 force feature enabled). The "BLOCKED" page adapts to the available screen
2116 space -- it displays full-blown if space allows, or miniaturized and
2117 text-only if loaded into a small frame or window. If you are using Privoxy
2118 right now, you can take a look at the "BLOCKED" page.
2120 A very important exception occurs if both block and handle-as-image, apply
2121 to the same request: it will then be replaced by an image. If
2122 set-image-blocker (see below) also applies, the type of image will be
2123 determined by its parameter, if not, the standard checkerboard pattern is
2126 It is important to understand this process, in order to understand how
2127 Privoxy deals with ads and other unwanted content.
2129 The filter action can perform a very similar task, by "blocking" banner
2130 images and other content through rewriting the relevant URLs in the
2131 document's HTML source, so they don't get requested in the first place.
2132 Note that this is a totally different technique, and it's easy to confuse
2135 Example usage (section):
2137 {+block} # Block and replace with "blocked" page
2138 .nasty-stuff.example.com
2140 {+block +handle-as-image} # Block and replace with image
2144 -------------------------------------------------------------------------------
2146 8.5.3. crunch-incoming-cookies
2150 Prevent the web server from setting any cookies on your system
2154 Deletes any "Set-Cookie:" HTTP headers from server replies.
2166 This action is only concerned with incoming cookies. For outgoing cookies,
2167 use crunch-outgoing-cookies. Use both to disable cookies completely.
2169 It makes no sense at all to use this action in conjunction with the
2170 session-cookies-only action, since it would prevent the session cookies
2175 +crunch-incoming-cookies
2177 -------------------------------------------------------------------------------
2179 8.5.4. crunch-outgoing-cookies
2183 Prevent the web server from reading any cookies from your system
2187 Deletes any "Cookie:" HTTP headers from client requests.
2199 This action is only concerned with outgoing cookies. For incoming cookies,
2200 use crunch-incoming-cookies. Use both to disable cookies completely.
2202 It makes no sense at all to use this action in conjunction with the
2203 session-cookies-only action, since it would prevent the session cookies
2208 +crunch-outgoing-cookies
2210 -------------------------------------------------------------------------------
2212 8.5.5. deanimate-gifs
2216 Stop those annoying, distracting animated GIF images.
2220 De-animate GIF animations, i.e. reduce them to their first or last image.
2232 This will also shrink the images considerably (in bytes, not pixels!). If
2233 the option "first" is given, the first frame of the animation is used as
2234 the replacement. If "last" is given, the last frame of the animation is
2235 used instead, which probably makes more sense for most banner animations,
2236 but also has the risk of not showing the entire last frame (if it is only a
2237 delta to an earlier frame).
2239 You can safely use this action with patterns that will also match non-GIF
2240 objects, because no attempt will be made at anything that doesn't look like
2245 +deanimate-gifs{last}
2247 -------------------------------------------------------------------------------
2249 8.5.6. downgrade-http-version
2253 Work around (very rare) problems with HTTP/1.1
2257 Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0.
2269 This is a left-over from the time when Privoxy didn't support important
2270 HTTP/1.1 features well. It is left here for the unlikely case that you
2271 experience HTTP/1.1 related problems with some server out there. Not all
2272 (optional) HTTP/1.1 features are supported yet, so there is a chance you
2273 might need this action.
2275 Example usage (section):
2277 {+downgrade-http-version}
2278 problem-host.example.com
2280 -------------------------------------------------------------------------------
2282 8.5.7. fast-redirects
2286 Fool some click-tracking scripts and speed up indirect links
2290 Cut off all but the last valid URL from requests.
2302 Many sites, like yahoo.com, don't just link to other sites. Instead, they
2303 will link to some script on their own servers, giving the destination as a
2304 parameter, which will then redirect you to the final target. URLs resulting
2305 from this scheme typically look like: http://some.place/click-tracker.cgi?
2306 target=http://some.where.else.
2308 Sometimes, there are even multiple consecutive redirects encoded in the
2309 URL. These redirections via scripts make your web browsing more traceable,
2310 since the server from which you follow such a link can see where you go to.
2311 Apart from that, valuable bandwidth and time is wasted, while your browser
2312 ask the server for one redirect after the other. Plus, it feeds the
2315 This feature is currently not very smart and is scheduled for improvement.
2316 It is likely to break some sites. You should expect to need possibly many
2317 exceptions to this action, if it is enabled by default in default.action.
2318 Some sites just don't work without it.
2324 -------------------------------------------------------------------------------
2330 Get rid of HTML and JavaScript annoyances, banner advertisements (by size),
2331 do fun text replacements, etc.
2335 Text documents, including HTML and JavaScript, to which this action
2336 applies, are filtered on-the-fly through the specified regular expression
2337 based substitutions.
2345 The name of a filter, as defined in the filter file (typically
2346 default.filter, set by the filterfile option in the config file)
2350 For your convenience, there are a bunch of pre-defined filters available in
2351 the distribution filter file that you can use. See the example below for a
2354 This is potentially a very powerful feature! But "rolling your own" filters
2355 requires a knowledge of regular expressions and HTML.
2357 Filtering requires buffering the page content, which may appear to slow
2358 down page rendering since nothing is displayed until all content has passed
2359 the filters. (It does not really take longer, but seems that way since the
2360 page is not incrementally displayed.) This effect will be more noticeable
2361 on slower connections.
2363 At this time, Privoxy cannot (yet!) uncompress compressed documents. If you
2364 want filtering to work on all documents, even those that would normally be
2365 sent compressed, use the prevent-compression action in conjunction with
2368 Filtering can achieve some of the effects as the block action, i.e. it can
2369 be used to block ads and banners.
2371 Feedback with suggestions for new or improved filters is particularly
2374 Example usage (with filters from the distribution default.filter file):
2376 +filter{html-annoyances} # Get rid of particularly annoying HTML abuse.
2378 +filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse
2380 +filter{banners-by-size} # Kill banners by size (very efficient!)
2382 +filter{content-cookies} # Kill cookies that come sneaking in the HTML or JS content
2384 +filter{popups} # Kill all popups in JS and HTML
2386 +filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking)
2388 +filter{fun} # Text replacements for subversive browsing fun!
2390 +filter{frameset-borders} # Give frames a border and make them resizeable
2392 +filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups)
2394 +filter{nimda} # Remove Nimda (virus) code.
2396 +filter{shockwave-flash} # Kill embedded Shockwave Flash objects
2398 +filter{crude-parental} # Kill all web pages that contain the words "sex" or "warez"
2400 -------------------------------------------------------------------------------
2402 8.5.9. handle-as-image
2406 Mark URLs as belonging to images (so they'll be replaced by images if they
2411 This action alone doesn't do anything noticeable. It just marks URLs as
2412 images. If the block action also applies, the presence or absence of this
2413 mark decides whether an HTML "blocked" page, or a replacement image (as
2414 determined by the set-image-blocker action) will be sent to the client as a
2415 substitute for the blocked content.
2427 The below generic example section is actually part of default.action. It
2428 marks all URLs with well-known image file name extensions as images and
2429 should be left intact.
2431 Users will probably only want to use the handle-as-image action in
2432 conjunction with block, to block sources of banners, whose URLs don't
2433 reflect the file type, like in the second example section.
2435 Note that you cannot treat HTML pages as images in most cases. For
2436 instance, (inline) ad frames require an HTML page to be sent, or they won't
2437 display properly. Forcing handle-as-image in this situation will not
2438 replace the ad frame with an image, but lead to error messages.
2440 Example usage (sections):
2442 # Generic image extensions:
2445 /.*\.(gif|jpg|jpeg|png|bmp|ico)$
2447 # These don't look like images, but they're banners and should be
2448 # blocked as images:
2450 {+block +handle-as-image}
2451 some.nasty-banner-server.com/junk.cgi?output=trash
2453 # Banner source! Who cares if they also have non-image content?
2456 -------------------------------------------------------------------------------
2458 8.5.10. hide-forwarded-for-headers
2462 Improve privacy by hiding the true source of the request
2466 Deletes any existing "X-Forwarded-for:" HTTP header from client requests,
2467 and prevents adding a new one.
2479 It is fairly safe to leave this on.
2481 This action is scheduled for improvement: It should be able to generate
2482 forged "X-Forwarded-for:" headers using random IP addresses from a
2483 specified network, to make successive requests from the same client look
2484 like requests from a pool of different users sharing the same proxy.
2488 +hide-forwarded-for-headers
2490 -------------------------------------------------------------------------------
2492 8.5.11. hide-from-header
2496 Keep your (old and ill) browser from telling web servers your email address
2500 Deletes any existing "From:" HTTP header, or replaces it with the specified
2509 Keyword: "block", or any user defined value.
2513 The keyword "block" will completely remove the header (not to be confused
2514 with the block action).
2516 Alternately, you can specify any value you prefer to be sent to the web
2517 server. If you do, it is a matter of fairness not to use any address that
2518 is actually used by a real person.
2520 This action is rarely needed, as modern web browsers don't send "From:"
2525 +hide-from-header{block}
2529 +hide-from-header{spam-me-senseless@sittingduck.example.com}
2531 -------------------------------------------------------------------------------
2533 8.5.12. hide-referrer
2537 Conceal which link you followed to get to a particular site
2541 Deletes the "Referer:" (sic) HTTP header from the client request, or
2542 replaces it with a forged one.
2550 + "block" to delete the header completely.
2552 + "forge" to pretend to be coming from the homepage of the server we are
2555 + Any other string to set a user defined referrer.
2559 "forge" is the preferred option here, since some servers will not send
2560 images back otherwise, in an attempt to prevent their valuable content from
2561 being embedded elsewhere (and hence, without being surrounded by their
2564 hide-referer is an alternate spelling of hide-referrer and the two can be
2565 can be freely substituted with each other. ("referrer" is the correct
2566 English spelling, however the HTTP specification has a bug - it requires it
2567 to be spelled as "referer".)
2571 +hide-referrer{forge}
2575 +hide-referrer{http://www.yahoo.com/}
2577 -------------------------------------------------------------------------------
2579 8.5.13. hide-user-agent
2583 Conceal your type of browser and client operating system
2587 Replaces the value of the "User-Agent:" HTTP header in client requests with
2588 the specified value.
2596 Any user-defined string.
2600 +-----------------------------------------------------------------+
2602 |-----------------------------------------------------------------|
2603 |This breaks many web sites that depend on looking at this header |
2604 |in order to customize their content for different browsers |
2605 |(which, by the way, is NOT a smart way to do that!). |
2606 +-----------------------------------------------------------------+
2608 Using this action in multi-user setups or wherever different types of
2609 browsers will access the same Privoxy is not recommended. In single-user,
2610 single-browser setups, you might use it to delete your OS version
2611 information from the headers, because it is an invitation to exploit known
2612 bugs for your OS. It is also occasionally useful to forge this in order to
2613 access sites that won't let you in otherwise (though there may be a good
2614 reason in some cases). Example of this: some MSN sites will not let Mozilla
2615 enter, yet forging to a Netscape 6.1 user-agent works just fine. (Must be
2616 just a silly MS goof, I'm sure :-).
2618 This action is scheduled for improvement.
2622 +hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}
2624 -------------------------------------------------------------------------------
2630 Eliminate those annoying pop-up windows
2634 While loading the document, replace JavaScript code that opens pop-up
2635 windows with (syntactically neutral) dummy code on the fly.
2647 This action is easily confused with the built-in, hardwired filter action,
2648 but there are important differences: For kill-popups, the document need not
2649 be buffered, so it can be incrementally rendered while downloading. But
2650 kill-popups doesn't catch as many pop-ups as filter{popups} does.
2652 Think of it as a fast and efficient replacement for a filter that you can
2653 use if you don't want any filtering at all. Note that it doesn't make sense
2654 to combine it with any filter action, since as soon as one filter applies,
2655 the whole document needs to be buffered anyway, which destroys the
2656 advantage of the kill-popups action over its filter equivalent.
2658 Killing all pop-ups is a dangerous business. Many shops and banks rely on
2659 pop-ups to display forms, shopping carts etc, and killing only the unwanted
2660 pop-ups would require artificial intelligence in Privoxy. If the only kind
2661 of pop-ups that you want to kill are exit consoles (those really nasty
2662 windows that appear when you close an other one), you might want to use
2663 filter{js-annoyances} instead.
2669 -------------------------------------------------------------------------------
2671 8.5.15. limit-connect
2675 Prevent abuse of Privoxy as a TCP proxy relay
2679 Specifies to which ports HTTP CONNECT requests are allowable.
2687 A comma-separated list of ports or port ranges (the latter using dashes,
2688 with the minimum defaulting to 0 and the maximum to 65K).
2692 By default, i.e. if no limit-connect action applies, Privoxy only allows
2693 HTTP CONNECT requests to port 443 (the standard, secure HTTPS port). Use
2694 limit-connect if more fine-grained control is desired for some or all
2697 The CONNECT methods exists in HTTP to allow access to secure websites
2698 ("https://" URLs) through proxies. It works very simply: the proxy connects
2699 to the server on the specified port, and then short-circuits its
2700 connections to the client and to the remote server. This can be a big
2701 security hole, since CONNECT-enabled proxies can be abused as TCP relays
2704 If you don't know what any of this means, there probably is no reason to
2705 change this one, since the default is already very restrictive.
2709 +limit-connect{443} # This is the default and need not be specified.
2710 +limit-connect{80,443} # Ports 80 and 443 are OK.
2711 +limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
2712 +limit-connect{-} # All ports are OK (gaping security hole!)
2714 -------------------------------------------------------------------------------
2716 8.5.16. prevent-compression
2720 Ensure that servers send the content uncompressed, so it can be passed
2725 Adds a header to the request that asks for uncompressed transfer.
2737 More and more websites send their content compressed by default, which is
2738 generally a good idea and saves bandwidth. But for the filter,
2739 deanimate-gifs and kill-popups actions to work, Privoxy needs access to the
2740 uncompressed data. Unfortunately, Privoxy can't yet(!) uncompress, filter,
2741 and re-compress the content on the fly. So if you want to ensure that all
2742 websites, including those that normally compress, can be filtered, you need
2745 This will slow down transfers from those websites, though. If you use any
2746 of the above-mentioned actions, you will typically want to use
2747 prevent-compression in conjunction with them.
2749 Note that some (rare) ill-configured sites don't handle requests for
2750 uncompressed documents correctly (they send an empty document body). If you
2751 use prevent-compression per default, you'll have to add exceptions for
2752 those sites. See the example for how to do that.
2754 Example usage (sections):
2758 {+prevent-compression}
2761 # Make exceptions for ill sites:
2763 {-prevent-compression}
2765 www.pclinuxonline.com
2767 -------------------------------------------------------------------------------
2769 8.5.17. send-vanilla-wafer
2773 Feed log analysis scripts with useless data.
2777 Sends a cookie with each request stating that you do not accept any
2778 copyright on cookies sent to you, and asking the site operator not to track
2791 The vanilla wafer is a (relatively) unique header and could conceivably be
2794 This action is rarely used and not enabled in the default configuration.
2800 -------------------------------------------------------------------------------
2806 Send custom cookies or feed log analysis scripts with even more useless
2811 Sends a custom, user-defined cookie with each request.
2819 A string of the form "name=value".
2823 Being multi-valued, multiple instances of this action can apply to the same
2824 request, resulting in multiple cookies being sent.
2826 This action is rarely used and not enabled in the default configuration.
2828 Example usage (section):
2830 {+send-wafer{UsingPrivoxy=true}}
2831 my-internal-testing-server.void
2833 -------------------------------------------------------------------------------
2835 8.5.19. session-cookies-only
2839 Allow only temporary "session" cookies (for the current browser session
2844 Deletes the "expires" field from "Set-Cookie:" server headers. Most
2845 browsers will not store such cookies permanently and forget them in between
2858 This is less strict than crunch-incoming-cookies / crunch-outgoing-cookies
2859 and allows you to browse websites that insist or rely on setting cookies,
2860 without compromising your privacy too badly.
2862 Most browsers will not permanently store cookies that have been processed
2863 by session-cookies-only and will forget about them between sessions. This
2864 makes profiling cookies useless, but won't break sites which require
2865 cookies so that you can log in for transactions. This is generally turned
2866 on for all sites, and is the recommended setting.
2868 It makes no sense at all to use session-cookies-only together with
2869 crunch-incoming-cookies or crunch-outgoing-cookies. If you do, cookies will
2872 Note that it is up to the browser how it handles such cookies without an
2873 "expires" field. If you use an exotic browser, you might want to try it out
2878 +session-cookies-only
2880 -------------------------------------------------------------------------------
2882 8.5.20. set-image-blocker
2886 Choose the replacement for blocked images
2890 This action alone doesn't do anything noticeable. If both block and
2891 handle-as-image also apply, i.e. if the request is to be blocked as an
2892 image, then the parameter of this action decides what will be sent as a
2901 + "pattern" to send a built-in checkerboard pattern image. The image is
2902 visually decent, scales very well, and makes it obvious where banners
2905 + "blank" to send a built-in transparent image. This makes banners
2906 disappear completely, but makes it hard to detect where Privoxy has
2907 blocked images on a given page and complicates troubleshooting if
2908 Privoxy has blocked innocent images, like navigation icons.
2910 + "target-url" to send a redirect to target-url. You can redirect to any
2911 image anywhere, even in your local filesystem (via "file:///" URL).
2913 A good application of redirects is to use special Privoxy-built-in
2914 URLs, which send the built-in images, as target-url. This has the same
2915 visual effect as specifying "blank" or "pattern" in the first place,
2916 but enables your browser to cache the replacement image, instead of
2917 requesting it over and over again.
2921 The URLs for the built-in images are "http://config.privoxy.org/
2922 send-banner?type=type", where type is either "blank" or "pattern".
2924 There is a third (advanced) type, called "auto". It is NOT to be used in
2925 set-image-blocker, but meant for use from filters. Auto will select the
2926 type of image that would have applied to the referring page, had it been an
2933 +set-image-blocker{pattern}
2935 Redirect to the BSD devil:
2937 +set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}
2939 Redirect to the built-in pattern for better caching:
2941 +set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}
2943 -------------------------------------------------------------------------------
2947 Note that many of these actions have the potential to cause a page to
2948 misbehave, possibly even not to display at all. There are many ways a site
2949 designer may choose to design his site, and what HTTP header content, and other
2950 criteria, he may depend on. There is no way to have hard and fast rules for all
2951 sites. See the Appendix for a brief example on troubleshooting actions.
2953 -------------------------------------------------------------------------------
2957 Custom "actions", known to Privoxy as "aliases", can be defined by combining
2958 other actions. These can in turn be invoked just like the built-in actions.
2959 Currently, an alias name can contain any character except space, tab, "=", "{"
2960 and "}", but we strongly recommend that you only use "a" to "z", "0" to "9",
2961 "+", and "-". Alias names are not case sensitive, and are not required to start
2962 with a "+" or "-" sign, since they are merely textually expanded.
2964 Aliases can be used throughout the actions file, but they must be defined in a
2965 special section at the top of the file! And there can only be one such section
2966 per actions file. Each actions file may have its own alias section, and the
2967 aliases defined in it are only visible within that file.
2969 There are two main reasons to use aliases: One is to save typing for frequently
2970 used combinations of actions, the other one is a gain in flexibility: If you
2971 decide once how you want to handle shops by defining an alias called "shop",
2972 you can later change your policy on shops in one place, and your changes will
2973 take effect everywhere in the actions file where the "shop" alias is used.
2974 Calling aliases by their purpose also makes your actions files more readable.
2976 Currently, there is one big drawback to using aliases, though: Privoxy's
2977 built-in web-based action file editor honors aliases when reading the actions
2978 files, but it expands them before writing. So the effects of your aliases are
2979 of course preserved, but the aliases themselves are lost when you edit sections
2980 that use aliases with it. This is likely to change in future versions of
2983 Now let's define some aliases...
2985 # Useful custom aliases we can use later.
2987 # Note the (required!) section header line and that this section
2988 # must be at the top of the actions file!
2992 # These aliases just save typing later:
2993 # (Note that some already use other aliases!)
2995 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
2996 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
2997 block-as-image = +block +handle-as-image
2998 mercy-for-cookies = -crunch-all-cookies -session-cookies-only
3000 # These aliases define combinations of actions
3001 # that are useful for certain types of sites:
3003 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
3004 shop = -crunch-all-cookies -filter{popups} -kill-popups
3006 # Short names for other aliases, for really lazy people ;-)
3008 c0 = +crunch-all-cookies
3009 c1 = -crunch-all-cookies
3011 ...and put them to use. These sections would appear in the lower part of an
3012 actions file and define exceptions to the default actions (as specified further
3013 up for the "/" pattern):
3015 # These sites are either very complex or very keen on
3016 # user data and require minimal interference to work:
3019 .office.microsoft.com
3020 .windowsupdate.microsoft.com
3024 # Allow cookies (for setting and retrieving your customer data)
3028 .worldpay.com # for quietpc.com
3031 # These shops require pop-ups:
3033 {shop -kill-popups -filter{popups}}
3037 Aliases like "shop" and "fragile" are often used for "problem" sites that
3038 require some actions to be disabled in order to function properly.
3040 -------------------------------------------------------------------------------
3042 8.7. Actions Files Tutorial
3044 The above chapters have shown which actions files there are and how they are
3045 organized, how actions are specified and applied to URLs, how patterns work,
3046 and how to define and use aliases. Now, let's look at an example default.action
3047 and user.action file and see how all these pieces come together:
3049 -------------------------------------------------------------------------------
3051 8.7.1. default.action
3053 Every config file should start with a short comment stating its purpose:
3055 # Sample default.action file <developers@privoxy.org>
3057 Then, since this is the default.action file, the first section is a special
3058 section for internal use that you needn't change or worry about:
3060 ##########################################################################
3061 # Settings -- Don't change! For internal Privoxy use ONLY.
3062 ##########################################################################
3065 for-privoxy-version=3.0
3067 After that comes the (optional) alias section. We'll use the example section
3068 from the above chapter on aliases, that also explains why and how aliases are
3071 ##########################################################################
3073 ##########################################################################
3076 # These aliases just save typing later:
3077 # (Note that some already use other aliases!)
3079 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
3080 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
3081 block-as-image = +block +handle-as-image
3082 mercy-for-cookies = -crunch-all-cookies -session-cookies-only
3084 # These aliases define combinations of actions
3085 # that are useful for certain types of sites:
3087 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
3088 shop = mercy-for-cookies -filter{popups} -kill-popups
3090 Now come the regular sections, i.e. sets of actions, accompanied by URL
3091 patterns to which they apply. Remember all actions are disabled when matching
3092 starts, so we have to explicitly enable the ones we want.
3094 The first regular section is probably the most important. It has only one
3095 pattern, "/", but this pattern matches all URLs.. Therefore, the set of actions
3096 used in this "default" section will be applied to all requests as a start. It
3097 can be partly or wholly overridden by later matches further down this file, or
3098 in user.action, but it will still be largely responsible for your overall
3099 browsing experience.
3101 Again, at the start of matching, all actions are disabled, so there is no real
3102 need to disable any actions here, but we will do that nonetheless, to have a
3103 complete listing for your reference. (Remember: A "+" preceding the action name
3104 enables the action, a "-" disables!). Also note how this long line has been
3105 made more readable by splitting it into multiple lines with line continuation.
3107 ##########################################################################
3108 # "Defaults" section:
3109 ##########################################################################
3113 -crunch-incoming-cookies \
3114 -crunch-outgoing-cookies \
3116 -downgrade-http-version \
3118 +filter{html-annoyances} \
3119 +filter{js-annoyances} \
3120 -filter{content-cookies} \
3123 -filter{refresh-tags} \
3126 +filter{banners-by-size} \
3127 -filter{shockwave-flash} \
3128 -filter{crude-parental} \
3130 +hide-forwarded-for-headers \
3131 +hide-from-header{block} \
3132 +hide-referrer{forge} \
3136 +prevent-compression \
3137 -send-vanilla-wafer \
3139 +session-cookies-only \
3140 +set-image-blocker{pattern} \
3142 / # forward slash will match *all* potential URL patterns.
3144 The default behavior is now set. Note that some actions, like not hiding the
3145 user agent, are part of a "general policy" that applies universally and won't
3146 get any exceptions defined later. Other choices, like not blocking (which is
3147 understandably the default!) need exceptions, i.e. we need to specify
3148 explicitly what we want to block in later sections. We will also want to make
3149 exceptions from our general pop-up-killing, and use our defined aliases for
3152 The first of our specialized sections is concerned with "fragile" sites, i.e.
3153 sites that require minimum interference, because they are either very complex
3154 or very keen on tracking you (and have mechanisms in place that make them
3155 unusable for people who avoid being tracked). We will simply use our
3156 pre-defined fragile alias instead of stating the list of actions explicitly:
3158 ##########################################################################
3159 # Exceptions for sites that'll break under the default action set:
3160 ##########################################################################
3162 # "Fragile" Use a minimum set of actions for these sites (see alias above):
3165 .office.microsoft.com # surprise, surprise!
3166 .windowsupdate.microsoft.com
3168 Shopping sites are not as fragile, but they typically require cookies to log
3169 in, and pop-up windows for shopping carts or item details. Again, we'll use a
3176 .worldpay.com # for quietpc.com
3180 Then, there are sites which rely on pop-up windows (yuck!) to work. Since we
3181 made pop-up-killing our default above, we need to make exceptions now. Mozilla
3182 users, who can turn on smart handling of unwanted pop-ups in their browsers,
3183 can safely choose -filter{popups} (and -kill-popups) above and hence don't need
3184 this section. Anyway, disabling an already disabled action doesn't hurt, so
3185 we'll define our exceptions regardless of what was chosen in the defaults
3188 # These sites require pop-ups too :(
3190 { -kill-popups -filter{popups} }
3193 .deutsche-bank-24.de
3195 The fast-redirects action, which we enabled per default above, breaks some
3196 sites. So disable it for popular sites where we know it misbehaves:
3202 .altavista.com/.*(like|url|link):http
3203 .altavista.com/trans.*urltext=http
3206 It is important that Privoxy knows which URLs belong to images, so that if they
3207 are to be blocked, a substitute image can be sent, rather than an HTML page.
3208 Contacting the remote site to find out is not an option, since it would destroy
3209 the loading time advantage of banner blocking, and it would feed the
3210 advertisers (in terms of money and information). We can mark any URL as an
3211 image with the handle-as-image action, and marking all URLs that end in a known
3212 image file extension is a good start:
3214 ##########################################################################
3216 ##########################################################################
3218 # Define which file types will be treated as images, in case they get
3219 # blocked further down this file:
3221 { +handle-as-image }
3222 /.*\.(gif|jpe?g|png|bmp|ico)$
3224 And then there are known banner sources. They often use scripts to generate the
3225 banners, so it won't be visible from the URL that the request is for an image.
3226 Hence we block them and mark them as images in one go, with the help of our
3227 block-as-image alias defined above. (We could of course just as well use +block
3228 +handle-as-image here.) Remember that the type of the replacement image is
3229 chosen by the set-image-blocker action. Since all URLs have matched the default
3230 section with its +set-image-blocker{pattern} action before, it still applies
3231 and needn't be repeated:
3233 # Known ad generators:
3238 .ad.*.doubleclick.net
3239 .a.yimg.com/(?:(?!/i/).)*$
3240 .a[0-9].yimg.com/(?:(?!/i/).)*$
3245 One of the most important jobs of Privoxy is to block banners. A huge bunch of
3246 them are already "blocked" by the filter{banners-by-size} action, which we
3247 enabled above, and which deletes the references to banner images from the pages
3248 while they are loaded, so the browser doesn't request them anymore, and hence
3249 they don't need to be blocked here. But this naturally doesn't catch all
3250 banners, and some people choose not to use filters, so we need a comprehensive
3251 list of patterns for banner URLs here, and apply the block action to them.
3253 First comes a bunch of generic patterns, which do most of the work, by matching
3254 typical domain and path name components of banners. Then comes a list of
3255 individual patterns for specific sites, which is omitted here to keep the
3258 ##########################################################################
3259 # Block these fine banners:
3260 ##########################################################################
3269 /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
3270 /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
3272 # Site-specific patterns (abbreviated):
3276 You wouldn't believe how many advertisers actually call their banner servers
3277 ads.company.com, or call the directory in which the banners are stored simply
3278 "banners". So the above generic patterns are surprisingly effective.
3280 But being very generic, they necessarily also catch URLs that we don't want to
3281 block. The pattern .*ads. e.g. catches "nasty-ads.nasty-corp.com" as intended,
3282 but also "downloads.sourcefroge.net" or "adsl.some-provider.net." So here come
3283 some well-known exceptions to the +block section above.
3285 Note that these are exceptions to exceptions from the default! Consider the URL
3286 "downloads.sourcefroge.net": Initially, all actions are deactivated, so it
3287 wouldn't get blocked. Then comes the defaults section, which matches the URL,
3288 but just deactivates the block action once again. Then it matches .*ads., an
3289 exception to the general non-blocking policy, and suddenly +block applies. And
3290 now, it'll match .*loads., where -block applies, so (unless it matches again
3291 further down) it ends up with no block action applying.
3293 ##########################################################################
3294 # Save some innocent victims of the above generic block patterns:
3295 ##########################################################################
3300 adv[io]*. # (for advogato.org and advice.*)
3301 adsl. # (has nothing to do with ads)
3302 ad[ud]*. # (adult.* and add.*)
3303 .edu # (universities don't host banners (yet!))
3304 .*loads. # (downloads, uploads etc)
3312 www.globalintersec.com/adv # (adv = advanced)
3313 www.ugu.com/sui/ugu/adv
3315 Filtering source code can have nasty side effects, so make an exception for our
3316 friends at sourceforge.net, and all paths with "cvs" in them. Note that -filter
3317 disables all filters in one fell swoop!
3319 # Don't filter code!
3325 The actual default.action is of course more comprehensive, but we hope this
3326 example made clear how it works.
3328 -------------------------------------------------------------------------------
3332 So far we are painting with a broad brush by setting general policies, which
3333 would be a reasonable starting point for many people. Now, you'd maybe want to
3334 be more specific and have customized rules that are more suitable to your
3335 personal habits and preferences. These would be for narrowly defined situations
3336 like your ISP or your bank, and should be placed in user.action, which is
3337 parsed after all other actions files and hence has the last word, over-riding
3338 any previously defined actions. user.action is also a safe place for your
3339 personal settings, since default.action is actively maintained by the Privoxy
3340 developers and you'll probably want to install updated versions from time to
3343 So let's look at a few examples of things that one might typically do in
3346 # My user.action file. <fred@foobar.com>
3348 As aliases are local to the actions file that they are defined in, you can't
3349 use the ones from default.action, unless you repeat them here:
3351 # (Re-)define aliases for this file:
3354 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
3355 mercy-for-cookies = -crunch-all-cookies -session-cookies-only
3356 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
3357 shop = mercy-for-cookies -filter{popups} -kill-popups
3358 allow-ads = -block -filter{banners-by-size} # (see below)
3360 Say you have accounts on some sites that you visit regularly, and you don't
3361 want to have to log in manually each time. So you'd like to allow persistent
3362 cookies for these sites. The mercy-for-cookies alias defined above does exactly
3363 that, i.e. it disables crunching of cookies in any direction, and processing of
3364 cookies to make them temporary.
3366 { mercy-for-cookies }
3373 Your bank needs popups and is allergic to some filter, but you don't know
3374 which, so you disable them all:
3376 { -filter -kill-popups }
3377 .your-home-banking-site.com
3379 While browsing the web with Privoxy you noticed some ads that sneaked through,
3380 but you were too lazy to report them through our fine and easy feedback system,
3381 so you have added them here:
3384 www.a-popular-site.com/some/unobvious/path
3385 another.popular.site.net/more/junk/here/
3387 Note that, assuming the banners in the above example have regular image
3388 extensions (most do), +handle-as-image need not be specified, since all URLs
3389 ending in these extensions will already have been tagged as images in the
3390 relevant section of default.action by now.
3392 Then you noticed that the default configuration breaks Forbes Magazine, but you
3393 were too lazy to find out which action is the culprit, and you were again too
3394 lazy to give feedback, so you just used the fragile alias on the site, and --
3400 You like the "fun" text replacements in default.filter, but it is disabled in
3401 the distributed actions file. (My colleagues on the team just don't have a
3402 sense of humour, that's why! ;-). So you'd like to turn it on in your private,
3403 update-safe config, once and for all:
3408 Note that the above is not really a good idea: There are exceptions to the
3409 filters in default.action for things that really shouldn't be filtered, like
3410 code on CVS->Web interfaces. Since user.action has the last word, these
3411 exceptions won't be valid for the "fun" filtering specified here.
3413 Finally, you might think about how your favourite free websites are funded, and
3414 find that they rely on displaying banner advertisements to survive. So you
3415 might want to specifically allow banners for those sites that you feel provide
3423 Note that allow-ads has been aliased to -block -filter{banners-by-size} above.
3425 -------------------------------------------------------------------------------
3429 All text substitutions that can be invoked through the filter action must first
3430 be defined in the filter file, which is typically called default.filter and
3431 which can be selected through the filterfile config option.
3433 Typical reasons for doing such substitutions are to eliminate common annoyances
3434 in HTML and JavaScript, such as pop-up windows, exit consoles, crippled windows
3435 without navigation tools, the infamous <BLINK> tag etc, to suppress images with
3436 certain width and height attributes (standard banner sizes or web-bugs), or
3437 just to have fun. The possibilities are endless.
3439 Filtering works on any text-based document type, including plain text, HTML,
3440 JavaScript, CSS etc. (all text/* MIME types). Substitutions are made at the
3441 source level, so if you want to "roll your own" filters, you should be familiar
3444 Just like the actions files, the filter file is organized in sections, which
3445 are called filters here. Each filter consists of a heading line, that starts
3446 with the keyword FILTER:, followed by the filter's name, and a short (one line)
3447 description of what it does. Below that line come the jobs, i.e. lines that
3448 define the actual text substitutions. By convention, the name of a filter
3449 should describe what the filter eliminates. The comment is used in the
3450 web-based user interface.
3452 Once a filter called name has been defined in the filter file, it can be
3453 invoked by using an action of the form +filter{name} in any actions file.
3455 A filter header line for a filter called "foo" could look like this:
3457 FILTER: foo Replace all "foo" with "bar"
3459 Below that line, and up to the next header line, come the jobs that define what
3460 text replacements the filter executes. They are specified in a syntax that
3461 imitates Perl's s/// operator. If you are familiar with Perl, you will find
3462 this to be quite intuitive, and may want to look at the PCRS man page for the
3463 subtle differences to Perl behaviour. Most notably, the non-standard option
3464 letter U is supported, which turns the default to ungreedy matching.
3466 If you are new to regular expressions, you might want to take a look at the
3467 Appendix on regular expressions, and see the Perl manual for the s///
3468 operator's syntax and Perl-style regular expressions in general. The below
3469 examples might also help to get you started.
3471 -------------------------------------------------------------------------------
3473 9.1. Filter File Tutorial
3475 Now, let's complete our "foo" filter. We have already defined the heading, but
3476 the jobs are still missing. Since all it does is to replace "foo" with "bar",
3477 there is only one (trivial) job needed:
3481 But wait! Didn't the comment say that all occurrences of "foo" should be
3482 replaced? Our current job will only take care of the first "foo" on each page.
3483 For global substitution, we'll need to add the g option:
3487 Our complete filter now looks like this:
3489 FILTER: foo Replace all "foo" with "bar"
3492 Let's look at some real filters for more interesting examples. Here you see a
3493 filter that protects against some common annoyances that arise from JavaScript
3494 abuse. Let's look at its jobs one after the other:
3496 FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse
3498 # Get rid of JavaScript referrer tracking. Test page: http://www.randomoddness.com/untitled.htm
3500 s|(<script.*)document\.referrer(.*</script>)|$1"Not Your Business!"$2|Usg
3502 Following the header line and a comment, you see the job. Note that it uses |
3503 as the delimiter instead of /, because the pattern contains a forward slash,
3504 which would otherwise have to be escaped by a backslash (\).
3506 Now, let's examine the pattern: it starts with the text <script.* enclosed in
3507 parentheses. Since the dot matches any character, and * means: "Match an
3508 arbitrary number of the element left of myself", this matches "<script",
3509 followed by any text, i.e. it matches the whole page, from the start of the
3512 That's more than we want, but the pattern continues: document\.referrer matches
3513 only the exact string "document.referrer". The dot needed to be escaped, i.e.
3514 preceded by a backslash, to take away its special meaning as a joker, and make
3515 it just a regular dot. So far, the meaning is: Match from the start of the
3516 first <script> tag in a the page, up to, and including, the text
3517 "document.referrer", if both are present in the page (and appear in that
3520 But there's still more pattern to go. The next element, again enclosed in
3521 parentheses, is .*</script>. You already know what .* means, so the whole
3522 pattern translates to: Match from the start of the first <script> tag in a page
3523 to the end of the last <script> tag, provided that the text "document.referrer"
3524 appears somewhere in between.
3526 This is still not the whole story, since we have ignored the options and the
3527 parentheses: The portions of the page matched by sub-patterns that are enclosed
3528 in parentheses, will be remembered and be available through the variables $1,
3529 $2, ... in the substitute. The U option switches to ungreedy matching, which
3530 means that the first .* in the pattern will only "eat up" all text in between "
3531 <script" and the first occurrence of "document.referrer", and that the second .
3532 * will only span the text up to the first "</script>" tag. Furthermore, the s
3533 option says that the match may span multiple lines in the page, and the g
3534 option again means that the substitution is global.
3536 So, to summarize, the pattern means: Match all scripts that contain the text
3537 "document.referrer". Remember the parts of the script from (and including) the
3538 start tag up to (and excluding) the string "document.referrer" as $1, and the
3539 part following that string, up to and including the closing tag, as $2.
3541 Now the pattern is deciphered, but wasn't this about substituting things? So
3542 lets look at the substitute: $1"Not Your Business!"$2 is easy to read: The text
3543 remembered as $1, followed by "Not Your Business!" (including the quotation
3544 marks!), followed by the text remembered as $2. This produces an exact copy of
3545 the original string, with the middle part (the "document.referrer") replaced by
3546 "Not Your Business!".
3548 The whole job now reads: Replace "document.referrer" by "Not Your Business!"
3549 wherever it appears inside a <script> tag. Note that this job won't break
3550 JavaScript syntax, since both the original and the replacement are
3551 syntactically valid string objects. The script just won't have access to the
3552 referrer information anymore.
3554 We'll show you two other jobs from the JavaScript taming department, but this
3555 time only point out the constructs of special interest:
3557 # The status bar is for displaying link targets, not pointless blahblah
3559 s/window\.status\s*=\s*['"].*?['"]/dUmMy=1/ig
3561 \s stands for whitespace characters (space, tab, newline, carriage return, form
3562 feed), so that \s* means: "zero or more whitespace". The ? in .*? makes this
3563 matching of arbitrary text ungreedy. (Note that the U option is not set). The
3564 ['"] construct means: "a single or a double quote".
3566 So what does this job do? It replaces assignments of single- or double-quoted
3567 strings to the "window.status" object with a dummy assignment (using a variable
3568 name that is hopefully odd enough not to conflict with real variables in
3569 scripts). Thus, it catches many cases where e.g. pointless descriptions are
3570 displayed in the status bar instead of the link target when you move your mouse
3573 # Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html
3575 s/(<body .*)onunload(.*>)/$1never$2/iU
3577 Including the OnUnload event binding in the HTML DOM was a CRIME. When I close
3578 a browser window, I want it to close and die. Basta. This job replaces the
3579 "onunload" attribute in "<body>" tags with the dummy word never. Note that the
3580 i option makes the pattern matching case-insensitive.
3582 The last example is from the fun department:
3584 FILTER: fun Fun text replacements
3586 # Spice the daily news:
3588 s/microsoft(?!\.com)/MicroSuck/ig
3590 Note the (?!\.com) part (a so-called negative lookahead) in the job's pattern,
3591 which means: Don't match, if the string ".com" appears directly following
3592 "microsoft" in the page. This prevents links to microsoft.com from being
3593 messed, while still replacing the word everywhere else.
3595 # Buzzword Bingo (example for extended regex syntax)
3597 s* industry[ -]leading \
3599 | award[ -]winning # Comments are OK, too! \
3600 | high[ -]performance \
3601 | solutions[ -]based \
3605 *<font color="red"><b>BINGO!</b></font> \
3608 The x option in this job turns on extended syntax, and allows for e.g. the
3609 liberal use of (non-interpreted!) whitespace for nicer formatting.
3613 -------------------------------------------------------------------------------
3617 All Privoxy built-in pages, i.e. error pages such as the "404 - No Such Domain"
3618 error page, the "BLOCKED" page and all pages of its web-based user interface,
3619 are generated from templates. (Privoxy must be running for the above links to
3622 These templates are stored in a subdirectory of the configuration directory
3623 called templates. On unixish platforms, this is typically /etc/privoxy/
3626 The templates are basically normal HTML files, but with place-holders (called
3627 symbols or exports), which Privoxy fills at run time. You can edit the
3628 templates with a normal text editor, should you want to customize them. (Not
3629 recommended for the casual user). Note that just like in configuration files,
3630 lines starting with # are ignored when the templates are filled in.
3632 The place-holders are of the form @name@, and you will find a list of available
3633 symbols, which vary from template to template, in the comments at the start of
3634 each file. Note that these comments are not always accurate, and that it's
3635 probably best to look at the existing HTML code to find out which symbols are
3636 supported and what they are filled in with.
3638 A special application of this substitution mechanism is to make whole blocks of
3639 HTML code disappear when a specific symbol is set. We use this for many
3640 purposes, one of them being to include the beta warning in all our user
3641 interface (CGI) pages when Privoxy in in an alpha or beta development stage:
3643 <!-- @if-unstable-start -->
3645 ... beta warning HTML code goes here ...
3647 <!-- if-unstable-end@ -->
3649 If the "unstable" symbol is set, everything in between and including
3650 @if-unstable-start and if-unstable-end@ will disappear, leaving nothing but an
3655 There's also an if-then-else construct and an #include mechanism, but you'll
3656 sure find out if you are inclined to edit the templates ;-)
3658 All templates refer to a style located at http://config.privoxy.org/
3659 send-stylesheet. This is, of course, locally served by Privoxy and the source
3660 for it can be found and edited in the cgi-style.css template.
3662 -------------------------------------------------------------------------------
3664 11. Contacting the Developers, Bug Reporting and Feature Requests
3666 We value your feedback. In fact, we rely on it to improve Privoxy and its
3667 configuration. However, please note the following hints, so we can provide you
3668 with the best support:
3670 -------------------------------------------------------------------------------
3674 For casual users, our support forum at SourceForge is probably best suited:
3675 http://sourceforge.net/tracker/?group_id=11118&atid=211118
3677 All users are of course welcome to discuss their issues on the users mailing
3678 list, where the developers also hang around.
3680 -------------------------------------------------------------------------------
3684 Please report all bugs only through our bug tracker: http://sourceforge.net/
3685 tracker/?group_id=11118&atid=111118.
3687 Before doing so, please make sure that the bug has not already been submitted
3688 and observe the aditional hints at the top of the submit form.
3690 Please try to verify that it is a Privoxy bug, and not a browser or site bug
3691 first. If unsure, try toggling off Privoxy, and see if the problem persists.
3692 The appendix of the user manual also has helpful information on action
3693 debugging. If you are using your own custom configuration, please try the stock
3694 configs to see if the problem is configuration related.
3696 If not using the latest version, chances are that the bug has been found and
3697 fixed in the meantime. We would appreciate if you could take the time to
3698 upgrade to the latest version (or even the latest CVS snapshot) and verify your
3699 bug, but this is not required for reporting.
3701 -------------------------------------------------------------------------------
3703 11.3. Request New Features
3705 You are welcome to submit ideas on new features or other proposals for
3706 improvement through our feature request tracker at http://sourceforge.net/
3707 tracker/?atid=361118&group_id=11118.
3709 -------------------------------------------------------------------------------
3711 11.4. Report Ads or Other Actions-Related Problems
3713 Please send feedback on ads that slipped through, innocent images that were
3714 blocked, and any other problems relating to the default.action file through our
3715 actions feedback mechanism located at http://www.privoxy.org/actions/. On this
3716 page, you will also find a bookmark which will take you back there from any
3717 troubled site and even pre-fill the form!
3719 New, improved default.action files will occasionally be made available based on
3720 your feedback. These will be announced on the ijbswa-announce list and
3721 available from our project page.
3723 -------------------------------------------------------------------------------
3727 For any other issues, feel free to use the mailing lists. Technically
3728 interested users and people who wish to contribute to the project are also
3729 welcome on the developers list! You can find an overview of all Prixoxy-related
3730 mailing lists, including list archives, at: http://sourceforge.net/mail/?
3733 -------------------------------------------------------------------------------
3735 12. Privoxy Copyright, License and History
3737 Copyright © 2001, 2002 by Privoxy Developers <developers@privoxy.org>
3739 Some source code is based on code Copyright © 1997 by Anonymous Coders and
3740 Junkbusters, Inc. and licensed under the GNU General Public License.
3742 -------------------------------------------------------------------------------
3746 Privoxy is free software; you can redistribute it and/or modify it under the
3747 terms of the GNU General Public License, version 2, as published by the Free
3748 Software Foundation.
3750 This program is distributed in the hope that it will be useful, but WITHOUT ANY
3751 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
3752 PARTICULAR PURPOSE. See the GNU General Public License for more details, which
3753 is available from the Free Software Foundation, Inc, 59 Temple Place - Suite
3754 330, Boston, MA 02111-1307, USA.
3756 You should have received a copy of the GNU General Public License along with
3757 this program; if not, write to the
3760 Foundation, Inc. 59 Temple Place - Suite 330
3761 Boston, MA 02111-1307
3764 -------------------------------------------------------------------------------
3768 In the beginning, there was the Internet Junkbuster, by Anonymous Coders and
3769 Junkbusters Corporation. It saved many users a lot of pain in the early days of
3770 web advertising and user tracking.
3772 But the web, its protocols and standards, and with it, the techniques for
3773 forcing users to consume ads, give up autonomy over their browsing, and for
3774 spying on them, kept evolving. Unfortunately, the Internet Junkbuster did not.
3775 Version 2.0.2, published in 1998, was (and is) the last official release
3776 available from Junkbusters Corporation. Fortunately, it had been released under
3777 the GNU GPL, which allowed further development by others.
3779 So Stefan Waldherr started maintaining an improved version of the software, to
3780 which eventually a number of people contributed patches. It could already
3781 replace banners with a transparent image, and had a first version of pop-up
3782 killing, but it was still very closely based on the original, with all its
3783 limitations, such as the lack of HTTP/1.1 support, flexible per-site
3784 configuration, or content modification. The last release from this effort was
3785 version 2.0.2-10, published in 2000.
3787 Then, some developers picked up the thread, and started turning the software
3788 inside out, upside down, and then reassembled it, adding many new features
3791 The result of this is Privoxy, whose first stable release, 3.0, is due in May
3794 -------------------------------------------------------------------------------
3798 Current Project Developers:
3807 Current Project Contributors:
3809 Rodrigo Barbosa (RPM specfiles)
3815 David Schmidt (OS/2, Mac OSX ports)
3819 Originally developed by:
3824 Thanks to the many people who have tested Privoxy, reported bugs, or made
3825 suggestions. These include (in alphabetical order):
3839 -------------------------------------------------------------------------------
3843 Other references and sites of interest to Privoxy users:
3845 http://www.privoxy.org/, the Privoxy Home page.
3847 http://www.privoxy.org/faq/, the Privoxy FAQ.
3849 http://sourceforge.net/projects/ijbswa/, the Project Page for Privoxy on
3852 http://config.privoxy.org/, the web-based user interface. Privoxy must be
3853 running for this to work. Shortcut: http://p.p/
3855 http://www.privoxy.org/actions/, to submit "misses" to the developers.
3857 http://www.junkbusters.com/ht/en/cookies.html, an explanation how cookies are
3858 used to track web users.
3860 http://www.junkbusters.com/ijb.html, the original Internet Junkbuster.
3862 http://www.waldherr.org/junkbuster/, Stefan Waldherr's version of Junkbuster,
3863 from which Privoxy was derived.
3865 http://privacy.net/analyze/, a useful site to check what information about you
3866 is leaked while you browse the web.
3868 http://www.squid-cache.org/, a very popular caching proxy, which is often used
3869 together with Privoxy.
3871 http://www.privoxy.org/developer-manual/, the Privoxy developer manual.
3873 -------------------------------------------------------------------------------
3877 14.1. Regular Expressions
3879 Privoxy uses Perl-style "regular expressions" in its actions files and filter
3880 file, through the PCRE and PCRS libraries.
3882 If you are reading this, you probably don't understand what "regular
3883 expressions" are, or what they can do. So this will be a very brief
3884 introduction only. A full explanation would require a book ;-)
3886 Regular expressions provide a language to describe patterns that can be run
3887 against strings of characters (letter, numbers, etc), to see if they match the
3888 string or not. The patterns are themselves (sometimes complex) strings of
3889 literal characters, combined with wild-cards, and other special characters,
3890 called meta-characters. The "meta-characters" have special meanings and are
3891 used to build complex patterns to be matched against. Perl Compatible Regular
3892 Expressions are an especially convenient "dialect" of the regular expression
3895 To make a simple analogy, we do something similar when we use wild-card
3896 characters when listing files with the dir command in DOS. *.* matches all
3897 filenames. The "special" character here is the asterisk which matches any and
3898 all characters. We can be more specific and use ? to match just individual
3899 characters. So "dir file?.text" would match "file1.txt", "file2.txt", etc. We
3900 are pattern matching, using a similar technique to "regular expressions"!
3902 Regular expressions do essentially the same thing, but are much, much more
3903 powerful. There are many more "special characters" and ways of building complex
3904 patterns however. Let's look at a few of the common ones, and then some
3907 . - Matches any single character, e.g. "a", "A", "4", ":", or "@".
3909 ? - The preceding character or expression is matched ZERO or ONE times. Either/
3912 + - The preceding character or expression is matched ONE or MORE times.
3914 * - The preceding character or expression is matched ZERO or MORE times.
3916 \ - The "escape" character denotes that the following character should be taken
3917 literally. This is used where one of the special characters (e.g. ".") needs to
3918 be taken literally and not as a special meta-character. Example: "example
3919 \.com", makes sure the period is recognized only as a period (and not expanded
3920 to its meta-character meaning of any single character).
3922 [] - Characters enclosed in brackets will be matched if any of the enclosed
3923 characters are encountered. For instance, "[0-9]" matches any numeric digit
3924 (zero through nine). As an example, we can combine this with "+" to match any
3925 digit one of more times: "[0-9]+".
3927 () - parentheses are used to group a sub-expression, or multiple
3930 | - The "bar" character works like an "or" conditional statement. A match is
3931 successful if the sub-expression on either side of "|" matches. As an example:
3932 "/(this|that) example/" uses grouping and the bar character and would match
3933 either "this example" or "that example", and nothing else.
3935 These are just some of the ones you are likely to use when matching URLs with
3936 Privoxy, and is a long way from a definitive list. This is enough to get us
3937 started with a few simple examples which may be more illuminating:
3939 /.*/banners/.* - A simple example that uses the common combination of "." and "
3940 *" to denote any character, zero or more times. In other words, any string at
3941 all. So we start with a literal forward slash, then our regular expression
3942 pattern (".*") another literal forward slash, the string "banners", another
3943 forward slash, and lastly another ".*". We are building a directory path here.
3944 This will match any file with the path that has a directory named "banners" in
3945 it. The ".*" matches any characters, and this could conceivably be more forward
3946 slashes, so it might expand into a much longer looking path. For example, this
3947 could match: "/eye/hate/spammers/banners/annoy_me_please.gif", or just "/
3948 banners/annoying.html", or almost an infinite number of other possible
3949 combinations, just so it has "banners" in the path somewhere.
3951 A now something a little more complex:
3953 /.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward
3954 slashes again ("/"), so we are building another expression that is a file path
3955 statement. We have another ".*", so we are matching against any conceivable
3956 sub-path, just so it matches our expression. The only true literal that must
3957 match our pattern is adv, together with the forward slashes. What comes after
3958 the "adv" string is the interesting part.
3960 Remember the "?" means the preceding expression (either a literal character or
3961 anything grouped with "(...)" in this case) can exist or not, since this means
3962 either zero or one match. So "((er)?ts?|ertis(ing|ements?))" is optional, as
3963 are the individual sub-expressions: "(er)", "(ing|ements?)", and the "s". The "
3964 |" means "or". We have two of those. For instance, "(ing|ements?)", can expand
3965 to match either "ing" OR "ements?". What is being done here, is an attempt at
3966 matching as many variations of "advertisement", and similar, as possible. So
3967 this would expand to match just "adv", or "advert", or "adverts", or
3968 "advertising", or "advertisement", or "advertisements". You get the idea. But
3969 it would not match "advertizements" (with a "z"). We could fix that by changing
3970 our regular expression to: "/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/", which
3971 would then match either spelling.
3973 /.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward
3974 slashes. Anything in the square brackets "[]" can be matched. This is using
3975 "0-9" as a shorthand expression to mean any digit one through nine. It is the
3976 same as saying "0123456789". So any digit matches. The "+" means one or more of
3977 the preceding expression must be included. The preceding expression here is
3978 what is in the square brackets -- in this case, any digit one through nine.
3979 Then, at the end, we have a grouping: "(gif|jpe?g)". This includes a "|", so
3980 this needs to match the expression on either side of that bar character also. A
3981 simple "gif" on one side, and the other side will in turn match either "jpeg"
3982 or "jpg", since the "?" means the letter "e" is optional and can be matched
3983 once or not at all. So we are building an expression here to match image GIF or
3984 JPEG type image file. It must include the literal string "advert", then one or
3985 more digits, and a "." (which is now a literal, and not a special character,
3986 since it is escaped with "\"), and lastly either "gif", or "jpeg", or "jpg".
3987 Some possible matches would include: "//advert1.jpg", "/nasty/ads/
3988 advert1234.gif", "/banners/from/hell/advert99.jpg". It would not match
3989 "advert1.gif" (no leading slash), or "/adverts232.jpg" (the expression does not
3990 include an "s"), or "/advert1.jsp" ("jsp" is not in the expression anywhere).
3992 We are barely scratching the surface of regular expressions here so that you
3993 can understand the default Privoxy configuration files, and maybe use this
3994 knowledge to customize your own installation. There is much, much more that can
3995 be done with regular expressions. Now that you know enough to get started, you
3996 can learn more on your own :/
3998 More reading on Perl Compatible Regular expressions: http://www.perldoc.com/
3999 perl5.6/pod/perlre.html
4001 For information on regular expression based substititions and their
4002 applications in filters, please see the filter file tutorial in this manual.
4004 -------------------------------------------------------------------------------
4006 14.2. Privoxy's Internal Pages
4008 Since Privoxy proxies each requested web page, it is easy for Privoxy to trap
4009 certain special URLs. In this way, we can talk directly to Privoxy, and see how
4010 it is configured, see how our rules are being applied, change these rules and
4011 other configuration options, and even turn Privoxy's filtering off, all with a
4014 The URLs listed below are the special ones that allow direct access to Privoxy.
4015 Of course, Privoxy must be running to access these. If not, you will get a
4016 friendly error message. Internet access is not necessary either.
4018 * Privoxy main page:
4020 http://config.privoxy.org/
4022 There is a shortcut: http://p.p/ (But it doesn't provide a fallback to a
4023 real page, in case the request is not sent through Privoxy)
4025 * Show information about the current configuration, including viewing and
4026 editing of actions files:
4028 http://config.privoxy.org/show-status
4030 * Show the source code version numbers:
4032 http://config.privoxy.org/show-version
4034 * Show the browser's request headers:
4036 http://config.privoxy.org/show-request
4038 * Show which actions apply to a URL and why:
4040 http://config.privoxy.org/show-url-info
4042 * Toggle Privoxy on or off. In this case, "Privoxy" continues to run, but
4043 only as a pass-through proxy, with no actions taking place:
4045 http://config.privoxy.org/toggle
4047 Short cuts. Turn off, then on:
4049 http://config.privoxy.org/toggle?set=disable
4051 http://config.privoxy.org/toggle?set=enable
4053 These may be bookmarked for quick reference. See next.
4055 -------------------------------------------------------------------------------
4057 14.2.1. Bookmarklets
4059 Below are some "bookmarklets" to allow you to easily access a "mini" version of
4060 some of Privoxy's special pages. They are designed for MS Internet Explorer,
4061 but should work equally well in Netscape, Mozilla, and other browsers which
4062 support JavaScript. They are designed to run directly from your bookmarks - not
4063 by clicking the links below (although that should work for testing).
4065 To save them, right-click the link and choose "Add to Favorites" (IE) or "Add
4066 Bookmark" (Netscape). You will get a warning that the bookmark "may not be
4067 safe" - just click OK. Then you can run the Bookmarklet directly from your
4068 favorites/bookmarks. For even faster access, you can put them on the "Links"
4069 bar (IE) or the "Personal Toolbar" (Netscape), and run them with a single
4076 * Privoxy - Toggle Privoxy (Toggles between enabled and disabled)
4078 * Privoxy- View Status
4080 * Privoxy - Submit Actions File Feedback
4082 Credit: The site which gave us the general idea for these bookmarklets is
4083 www.bookmarklets.com. They have more information about bookmarklets.
4085 -------------------------------------------------------------------------------
4087 14.3. Chain of Events
4089 Let's take a quick look at the basic sequence of events when a web page is
4090 requested by your browser and Privoxy is on duty:
4092 * First, your web browser requests a web page. The browser knows to send the
4093 request to Privoxy, which will in turn, relay the request to the remote web
4094 server after passing the following tests:
4096 * Privoxy traps any request for its own internal CGI pages (e.g http://p.p/)
4097 and sends the CGI page back to the browser.
4099 * Next, Privoxy checks to see if the URL matches any "+block" patterns. If
4100 so, the URL is then blocked, and the remote web server will not be
4101 contacted. "+handle-as-image" is then checked and if it does not match, an
4102 HTML "BLOCKED" page is sent back. Otherwise, if it does match, an image is
4103 returned. The type of image depends on the setting of "+set-image-blocker"
4104 (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
4106 * Untrusted URLs are blocked. If URLs are being added to the trust file, then
4109 * If the URL pattern matches the "+fast-redirects" action, it is then
4110 processed. Unwanted parts of the requested URL are stripped.
4112 * Now the rest of the client browser's request headers are processed. If any
4113 of these match any of the relevant actions (e.g. "+hide-user-agent", etc.),
4114 headers are suppressed or forged as determined by these actions and their
4117 * Now the web server starts sending its response back (i.e. typically a web
4118 page and related data).
4120 * First, the server headers are read and processed to determine, among other
4121 things, the MIME type (document type) and encoding. The headers are then
4122 filtered as deterimed by the "+crunch-incoming-cookies",
4123 "+session-cookies-only", and "+downgrade-http-version" actions.
4125 * If the "+kill-popups" action applies, and it is an HTML or JavaScript
4126 document, the popup-code in the response is filtered on-the-fly as it is
4129 * If a "+filter" or "+deanimate-gifs" action applies (and the document type
4130 fits the action), the rest of the page is read into memory (up to a
4131 configurable limit). Then the filter rules (from default.filter) are
4132 processed against the buffered content. Filters are applied in the order
4133 they are specified in the default.filter file. Animated GIFs, if present,
4134 are reduced to either the first or last frame, depending on the action
4135 setting.The entire page, which is now filtered, is then sent by Privoxy
4136 back to your browser.
4138 If neither "+filter" or "+deanimate-gifs" matches, then Privoxy passes the
4139 raw data through to the client browser as it becomes available.
4141 * As the browser receives the now (probably filtered) page content, it reads
4142 and then requests any URLs that may be embedded within the page source,
4143 e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
4144 frames), sounds, etc. For each of these objects, the browser issues a new
4145 request. And each such request is in turn processed as above. Note that a
4146 complex web page may have many such embedded URLs.
4148 -------------------------------------------------------------------------------
4150 14.4. Anatomy of an Action
4152 The way Privoxy applies actions and filters to any given URL can be complex,
4153 and not always so easy to understand what is happening. And sometimes we need
4154 to be able to see just what Privoxy is doing. Especially, if something Privoxy
4155 is doing is causing us a problem inadvertently. It can be a little daunting to
4156 look at the actions and filters files themselves, since they tend to be filled
4157 with regular expressions whose consequences are not always so obvious.
4159 One quick test to see if Privoxy is causing a problem or not, is to disable it
4160 temporarily. This should be the first troubleshooting step. See the
4161 Bookmarklets section on a quick and easy way to do this (be sure to flush
4164 Privoxy also provides the http://config.privoxy.org/show-url-info page that can
4165 show us very specifically how actions are being applied to any given URL. This
4166 is a big help for troubleshooting.
4168 First, enter one URL (or partial URL) at the prompt, and then Privoxy will tell
4169 us how the current configuration will handle it. This will not help with
4170 filtering effects (i.e. the "+filter" action) from the default.filter file
4171 since this is handled very differently and not so easy to trap! It also will
4172 not tell you about any other URLs that may be embedded within the URL you are
4173 testing. For instance, images such as ads are expressed as URLs within the raw
4174 page source of HTML pages. So you will only get info for the actual URL that is
4175 pasted into the prompt area -- not any sub-URLs. If you want to know about
4176 embedded URLs like ads, you will have to dig those out of the HTML source. Use
4177 your browser's "View Page Source" option for this. Or right click on the ad,
4180 Let's try an example, google.com, and look at it one section at a time:
4182 Matches for http://google.com:
4184 In file: default.action [ View ] [ Edit ]
4188 -crunch-outgoing-cookies
4189 -crunch-incoming-cookies
4190 +deanimate-gifs{last}
4191 -downgrade-http-version
4195 -filter{shockwave-flash}
4196 -filter{crude-parental}
4197 +filter{html-annoyances}
4198 +filter{js-annoyances}
4199 +filter{content-cookies}
4201 +filter{refresh-tags}
4203 +filter{banners-by-size}
4204 +hide-forwarded-for-headers
4205 +hide-from-header{block}
4206 +hide-referer{forge}
4211 +prevent-compression
4214 +session-cookies-only
4215 +set-image-blocker{pattern} }
4218 { -session-cookies-only }
4224 In file: user.action [ View ] [ Edit ]
4225 (no matches in this file)
4227 This tells us how we have defined our "actions", and which ones match for our
4228 example, "google.com". The first listing is any matches for the standard.action
4229 file. No hits at all here on "standard". Then next is "default", or our
4230 default.action file. The large, multi-line listing, is how the actions are set
4231 to match for all URLs, i.e. our default settings. If you look at your "actions"
4232 file, this would be the section just below the "aliases" section near the top.
4233 This will apply to all URLs as signified by the single forward slash at the end
4234 of the listing -- "/".
4236 But we can define additional actions that would be exceptions to these general
4237 rules, and then list specific URLs (or patterns) that these exceptions would
4238 apply to. Last match wins. Just below this then are two explicit matches for
4239 ".google.com". The first is negating our previous cookie setting, which was for
4240 "+session-cookies-only" (i.e. not persistent). So we will allow persistent
4241 cookies for google. The second turns off any "+fast-redirects" action, allowing
4242 this to take place unmolested. Note that there is a leading dot here --
4243 ".google.com". This will match any hosts and sub-domains, in the google.com
4244 domain also, such as "www.google.com". So, apparently, we have these two
4245 actions defined somewhere in the lower part of our default.action file, and
4246 "google.com" is referenced somewhere in these latter sections.
4248 Then, for our user.action file, we again have no hits.
4250 And finally we pull it all together in the bottom section and summarize how
4251 Privoxy is applying all its "actions" to "google.com":
4257 -crunch-outgoing-cookies
4258 -crunch-incoming-cookies
4259 +deanimate-gifs{last}
4260 -downgrade-http-version
4264 -filter{shockwave-flash}
4265 -filter{crude-parental}
4266 +filter{html-annoyances}
4267 +filter{js-annoyances}
4268 +filter{content-cookies}
4270 +filter{refresh-tags}
4272 +filter{banners-by-size}
4273 +hide-forwarded-for-headers
4274 +hide-from-header{block}
4275 +hide-referer{forge}
4280 +prevent-compression
4283 -session-cookies-only
4284 +set-image-blocker{pattern}
4286 Notice the only difference here to the previous listing, is to "fast-redirects"
4287 and "session-cookies-only".
4289 Now another example, "ad.doubleclick.net":
4291 { +block +handle-as-image }
4294 { +block +handle-as-image }
4297 { +block +handle-as-image }
4300 We'll just show the interesting part here, the explicit matches. It is matched
4301 three different times. Each as an "+block +handle-as-image", which is the
4302 expanded form of one of our aliases that had been defined as: "+imageblock". (
4303 "Aliases" are defined in the first section of the actions file and typically
4304 used to combine more than one action.)
4306 Any one of these would have done the trick and blocked this as an unwanted
4307 image. This is unnecessarily redundant since the last case effectively would
4308 also cover the first. No point in taking chances with these guys though ;-)
4309 Note that if you want an ad or obnoxious URL to be invisible, it should be
4310 defined as "ad.doubleclick.net" is done here -- as both a "+block" and an
4311 "+handle-as-image". The custom alias "+imageblock" just simplifies the process
4312 and make it more readable.
4314 One last example. Let's try "http://www.rhapsodyk.net/adsl/HOWTO/". This one is
4315 giving us problems. We are getting a blank page. Hmmm...
4317 Matches for http://www.rhapsodyk.net/adsl/HOWTO/:
4319 In file: default.action [ View ] [ Edit ]
4323 -crunch-incoming-cookies
4324 -crunch-outgoing-cookies
4326 -downgrade-http-version
4328 +filter{html-annoyances}
4329 +filter{js-annoyances}
4330 +filter{kill-popups}
4333 +filter{banners-by-size}
4336 +hide-forwarded-for-headers
4337 +hide-from-header{block}
4338 +hide-referer{forge}
4342 +prevent-compression
4345 +session-cookies-only
4346 +set-image-blocker{blank} }
4349 { +block +handle-as-image }
4352 Ooops, the "/adsl/" is matching "/ads"! But we did not want this at all! Now we
4353 see why we get the blank page. We could now add a new action below this that
4354 explicitly does not block ("{-block}") paths with "adsl". There are various
4355 ways to handle such exceptions. Example:
4360 Now the page displays ;-) Be sure to flush your browser's caches when making
4361 such changes. Or, try using Shift+Reload.
4363 But now what about a situation where we get no explicit matches like we did
4366 { +block +handle-as-image }
4369 That actually was very telling and pointed us quickly to where the problem was.
4370 If you don't get this kind of match, then it means one of the default rules in
4371 the first section is causing the problem. This would require some guesswork,
4372 and maybe a little trial and error to isolate the offending rule. One likely
4373 cause would be one of the "{+filter}" actions. Try adding the URL for the site
4374 to one of aliases that turn off "+filter":
4378 .worldpay.com # for quietpc.com
4383 "{shop}" is an "alias" that expands to "{ -filter -session-cookies-only }". Or
4384 you could do your own exception to negate filtering:
4389 This would probably be most appropriately put in user.action, for local site
4392 "{fragile}" is an alias that disables most actions. This can be used as a last
4393 resort for problem sites. Remember to flush caches! If this still does not
4394 work, you will have to go through the remaining actions one by one to find
4395 which one(s) is causing the problem.
projects / privoxy.git / blob