5 $Id: user-manual.sgml,v 1.99 2002/04/28 16:59:05 swa 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 -------------------------------------------------------------------------------
32 3.1. Red Hat and SuSE RPMs
35 3.4. Solaris, NetBSD, FreeBSD, HP-UX
41 5. Quickstart to Using Privoxy
44 6.1. RedHat and Debian
47 6.4. Solaris, NetBSD, FreeBSD, HP-UX and others
51 6.8. Command Line Options
53 7. Privoxy Configuration
55 7.1. Controlling Privoxy with Your Web Browser
56 7.2. Configuration Files Overview
58 8. The Main Configuration File
60 8.1. Configuration and Log File Locations
71 8.2. Local Set-up Documentation
80 8.3.2. single-threaded
82 8.4. Access Control and Security
86 8.4.3. enable-remote-toggle
87 8.4.4. enable-edit-actions
88 8.4.5. ACLs: permit-access and deny-access
94 8.5.2. forward-socks4 and forward-socks4a
95 8.5.3. Advanced Forwarding Examples
97 8.6. Windows GUI Options
101 9.1. Finding the Right Mix
103 9.3. How Actions are Applied to URLs
106 9.4.1. The Domain Pattern
107 9.4.2. The Path Pattern
113 9.5.3. +deanimate-gifs
114 9.5.4. +downgrade-http-version
115 9.5.5. +fast-redirects
117 9.5.7. +hide-forwarded-for-headers
118 9.5.8. +hide-from-header
120 9.5.10. +hide-user-agent
121 9.5.11. +handle-as-image
122 9.5.12. +set-image-blocker
123 9.5.13. +limit-connect
124 9.5.14. +prevent-compression
125 9.5.15. +session-cookies-only
126 9.5.16. +prevent-reading-cookies
127 9.5.17. +prevent-setting-cookies
129 9.5.19. +send-vanilla-wafer
132 9.5.22. Sample Actions Files
138 10.1. The +filter Action
141 12. Contacting the Developers, Bug Reporting and Feature Requests
145 12.3. Request new features
146 12.4. Report ads or other filter problems
149 13. Copyright and History
157 15.1. Regular Expressions
158 15.2. Privoxy's Internal Pages
162 15.3. Chain of Events
163 15.4. Anatomy of an Action
165 -------------------------------------------------------------------------------
169 This documentation is included with the current beta version of Privoxy,
170 v.2.9.14, and is mostly complete at this point. The most up to date reference
171 for the time being is still the comments in the source files and in the
172 individual configuration files. Development of version 3.0 is currently nearing
173 completion, and includes many significant changes and enhancements over earlier
174 versions. The target release date for stable v3.0 is "soon" ;-).
176 Since this is a beta version, not all new features are well tested. This
177 documentation may be slightly out of sync as a result (especially with CVS
178 sources). And there may be bugs, though hopefully not many!
180 -------------------------------------------------------------------------------
184 In addition to Internet Junkbuster's traditional features of ad and banner
185 blocking and cookie management, Privoxy provides new features, some of them
186 currently under development:
188 * FIXME: complete the list of features. change the order: most important
189 features to the top of the list. prefix new features with "NEW".
191 * Integrated browser based configuration and control utility at http://
192 config.privoxy.org/ (shortcut: http://p.p/). Browser-based tracing of rule
193 and filter effects. Remote toggling.
195 * Blocking of annoying pop-up browser windows.
197 * HTTP/1.1 compliant (but not all optional 1.1 features are supported).
199 * Support for Perl Compatible Regular Expressions in the configuration files,
200 and generally a more sophisticated and flexible configuration syntax over
205 * Web page content filtering (removes banners based on size, invisible
206 "web-bugs", JavaScript and HTML annoyances, pop-ups, etc.)
208 * Bypass many click-tracking scripts (avoids script redirection).
210 * Multi-threaded (POSIX and native threads).
212 * Auto-detection and re-reading of config file changes.
214 * User-customizable HTML templates (e.g. 404 error page).
216 * Improved cookie management features (e.g. session based cookies).
218 * Improved signal handling, and a true daemon mode (Unix).
220 * Every feature now controllable on a per-site or per-location basis,
221 configuration more powerful and versatile over-all.
223 * Many smaller new features added, limitations and bugs removed, and security
226 -------------------------------------------------------------------------------
230 Privoxy is available both in convenient pre-compiled packages for a wide range
231 of operating systems, and as raw source code. For most users, we recommend
232 using the packages, which can be downloaded from our Privoxy Project Page. For
233 installing and compiling the source code, please look into our Developer
236 If you like to live on the bleeding edge and are not afraid of using possibly
237 unstable development versions, you can check out the up-to-the-minute version
238 directly from the CVS repository or simply download the nightly CVS tarball.
239 Again, we refer you to the Developer Manual.
241 At present, Privoxy is known to run on Windows(95, 98, ME, 2000, XP), Linux
242 (RedHat, Suse, Debian), Mac OSX, OS/2, AmigaOS, FreeBSD, NetBSD, BeOS, and many
243 more flavors of Unix.
245 Note: If you have a previous Junkbuster or Privoxy installation on your system,
246 you will need to remove it. Some platforms do this for you as part of their
247 installation procedure. (See below for your platform).
249 In any case be sure to backup your old configuration if it is valuable to you.
250 See the note to upgraders section below.
252 -------------------------------------------------------------------------------
254 3.1. Red Hat and SuSE RPMs
256 RPMs can be installed with rpm -Uvh privoxy-2.9.14-1.rpm, and will use /etc/
257 privoxy for the location of configuration files.
259 Note that on Red Hat, Privoxy will not be automatically started on system boot.
260 You will need to enable that using chkconfig, ntsysv, or similar methods. Note
261 that SuSE will automatically start Privoxy in the boot process.
263 If you have problems with failed dependencies, try rebuilding the SRC RPM: rpm
264 --rebuild privoxy-2.9.14-1.src.rpm;. This will use your locally installed
265 libraries and RPM version.
267 Also note that if you have a Junkbuster RPM installed on your system, you need
268 to remove it first, because the packages conflict. Otherwise, RPM will try to
269 remove Junkbuster automatically, before installing Privoxy.
271 -------------------------------------------------------------------------------
277 -------------------------------------------------------------------------------
281 Just double-click the installer, which will guide you through the installation
282 process. You will find the configuration files in the same directory as you
283 installed Privoxy in. We do not use the registry of Windows.
285 -------------------------------------------------------------------------------
287 3.4. Solaris, NetBSD, FreeBSD, HP-UX
289 Create a new directory, cd to it, then unzip and untar the archive. For the
290 most part, you'll have to figure out where things go. FIXME.
292 -------------------------------------------------------------------------------
296 First, make sure that no previous installations of Junkbuster and / or Privoxy
297 are left on your system. You can do this by
299 Then, just double-click the WarpIN self-installing archive, which will guide
300 you through the installation process. A shadow of the Privoxy executable will
301 be placed in your startup folder so it will start automatically whenever OS/2
304 The directory you choose to install Privoxy into will contain all of the
307 -------------------------------------------------------------------------------
311 Unzip the downloaded package (you can either double-click on the file in the
312 finder, or on the desktop if you downloaded it there). Then, double-click on
313 the package installer icon and follow the installation process. Privoxy will be
314 installed in the subdirectory /Applications/Privoxy.app. Privoxy will set
315 itself up to start automatically on system bring-up via /System/Library/
316 StartupItems/Privoxy.
318 -------------------------------------------------------------------------------
322 Copy and then unpack the lha archive to a suitable location. All necessary
323 files will be installed into Privoxy directory, including all configuration and
324 log files. To uninstall, just remove this directory.
326 Start Privoxy (with RUN <>NIL:) in your startnet script (AmiTCP), in s:
327 user-startup (RoadShow), as startup program in your startup script (Genesis),
328 or as startup action (Miami and MiamiDx). Privoxy will automatically quit when
329 you quit your TCP/IP stack (just ignore the harmless warning your TCP/IP stack
330 may display that Privoxy is still running).
332 -------------------------------------------------------------------------------
336 There are very significant changes from older versions of Junkbuster to the
337 current Privoxy. Configuration is substantially changed. Junkbuster 2.0.x and
338 earlier configuration files will not migrate. The functionality of the old
339 blockfile, cookiefile and imagelist, are now combined into the "actions files".
340 default.action, is the main actions file. Local exceptions should best be put
343 A "filter file" (typically default.filter) is new as of Privoxy 2.9.x, and
344 provides some of the new sophistication (explained below). config is much the
347 If upgrading from a 2.0.x version, you will have to use the new config files,
348 and possibly adapt any personal rules from your older files. When porting
349 personal rules over from the old blockfile to the new actions files, please
350 note that even the pattern syntax has changed. If upgrading from 2.9.x
351 development versions, it is still recommended to use the new configuration
354 A quick list of things to be aware of before upgrading:
356 * The default listening port is now 8118 due to a conflict with another
359 * Some installers may remove earlier versions completely. Save any important
362 * Privoxy is controllable with a web browser at the special URL: http://
363 config.privoxy.org/ (Shortcut: http://p.p/). Many aspects of configuration
364 can be done here, including temporarily disabling Privoxy.
366 * The primary configuration file for cookie management, ad and banner
367 blocking, and many other aspects of Privoxy configuration is in the actions
368 files. It is strongly recommended to become familiar with the new actions
369 concept below, before modifying these files. Locally defined rules should
372 * Some installers may not automatically start Privoxy after installation.
374 -------------------------------------------------------------------------------
376 5. Quickstart to Using Privoxy
378 * Install Privoxy. See the section Installing.
380 * Start Privoxy. See the section Starting Privoxy.
382 * Change your browser's configuration to use the proxy localhost on port
383 8118. See the section Starting Privoxy.
385 * Enjoy surfing with enhanced comfort and privacy. Please see the section
386 Contacting the Developers on how to report bugs or problems with websites
387 or to get help. You may want to change the file user.action to further
388 tweak your new browsing experience.
390 -------------------------------------------------------------------------------
394 Before launching Privoxy for the first time, you will want to configure your
395 browser(s) to use Privoxy as a HTTP and HTTPS proxy. The default is localhost
396 for the proxy address, and port 8118 (earlier versions used port 8000). This is
397 the one configuration step that must be done!
399 With Netscape (and Mozilla), this can be set under Edit -> Preferences ->
400 Advanced -> Proxies -> HTTP Proxy. For Internet Explorer: Tools -> Internet
401 Properties -> Connections -> LAN Setting. Then, check "Use Proxy" and fill in
402 the appropriate info (Address: localhost, Port: 8118). Include if HTTPS proxy
405 After doing this, flush your browser's disk and memory caches to force a
406 re-reading of all pages and to get rid of any ads that may be cached. You are
407 now ready to start enjoying the benefits of using Privoxy!
409 Privoxy is typically started by specifying the main configuration file to be
410 used on the command line. If no configuration file is specified on the command
411 line, Privoxy will look for a file named config in the current directory.
412 Except on Win32 where it will try config.txt.
414 -------------------------------------------------------------------------------
416 6.1. RedHat and Debian
418 We use a script. Note that RedHat does not start Privoxy upon booting per
419 default. It will use the file /etc/privoxy/config as its main configuration
420 file. FIXME: Debian??
422 # /etc/rc.d/init.d/privoxy start
424 -------------------------------------------------------------------------------
428 We use a script. It will use the file /etc/privoxy/config as its main
429 configuration file. Note that SuSE starts Privoxy upon booting your PC.
433 -------------------------------------------------------------------------------
437 Click on the Privoxy Icon to start Privoxy. If no configuration file is
438 specified on the command line, Privoxy will look for a file named config.txt.
439 Note that Windows will automatically start Privoxy upon booting you PC.
441 -------------------------------------------------------------------------------
443 6.4. Solaris, NetBSD, FreeBSD, HP-UX and others
445 Example Unix startup command:
447 # /usr/sbin/privoxy /etc/privoxy/config
449 -------------------------------------------------------------------------------
455 -------------------------------------------------------------------------------
461 -------------------------------------------------------------------------------
467 -------------------------------------------------------------------------------
469 6.8. Command Line Options
471 Privoxy may be invoked with the following command-line options:
475 Print version info and exit. Unix only.
479 Print short usage info and exit. Unix only.
483 Don't become a daemon, i.e. don't fork and become process group leader, and
484 don't detach from controlling tty. Unix only.
488 On startup, write the process ID to FILE. Delete the FILE on exit. Failure
489 to create or delete the FILE is non-fatal. If no FILE option is given, no
490 PID file will be used. Unix only.
492 * --user USER[.GROUP]
494 After (optionally) writing the PID file, assume the user ID of USER, and if
495 included the GID of GROUP. Exit if the privileges are not sufficient to do
500 If no configfile is included on the command line, Privoxy will look for a
501 file named "config" in the current directory (except on Win32 where it will
502 look for "config.txt" instead). Specify full path to avoid confusion. If no
503 config file is found, Privoxy will fail to start.
505 -------------------------------------------------------------------------------
507 7. Privoxy Configuration
509 All Privoxy configuration is stored in text files. These files can be edited
510 with a text editor. Many important aspects of Privoxy can also be controlled
511 easily with a web browser.
513 -------------------------------------------------------------------------------
515 7.1. Controlling Privoxy with Your Web Browser
517 Privoxy's user interface can be reached through the special URL http://
518 config.privoxy.org/ (shortcut: http://p.p/), which is a built-in page and works
519 without Internet access. You will see the following section:
522 ? View & change the current configuration
523 ? View the source code version numbers
524 ? View the request headers.
525 ? Look up which actions apply to a URL and why
526 ? Toggle Privoxy on or off
529 This should be self-explanatory. Note the first item leads to an editor for the
530 "actions list", which is where the ad, banner, cookie, and URL blocking magic
531 is configured as well as other advanced features of Privoxy. This is an easy
532 way to adjust various aspects of Privoxy configuration. The actions file, and
533 other configuration files, are explained in detail below.
535 "Toggle Privoxy On or Off" is handy for sites that might have problems with
536 your current actions and filters. You can in fact use it as a test to see
537 whether it is Privoxy causing the problem or not. Privoxy continues to run as a
538 proxy in this case, but all filtering is disabled. There is even a toggle
539 Bookmarklet offered, so that you can toggle Privoxy with one click from your
542 -------------------------------------------------------------------------------
544 7.2. Configuration Files Overview
546 For Unix, *BSD and Linux, all configuration files are located in /etc/privoxy/
547 by default. For MS Windows, OS/2, and AmigaOS these are all in the same
548 directory as the Privoxy executable. The name and number of configuration files
549 has changed from previous versions, and is subject to change as development
552 The installed defaults provide a reasonable starting point, though some
553 settings may be aggressive by some standards. For the time being, the principle
554 configuration files are:
556 * The main configuration file is named config on Linux, Unix, BSD, OS/2, and
557 AmigaOS and config.txt on Windows. This is a required file.
559 * default.action (the main actions file) is used to define the default
560 settings for various "actions" relating to images, banners, pop-ups, access
561 restrictions, banners and cookies.
563 Multiple actions files may be defined in config. These are processed in the
564 order they are defined. Local customizations and locally preferred
565 exceptions to the default policies as defined in default.action are
566 probably best applied in user.action, which should be preserved across
567 upgrades. standard.action is also included. This is mostly for Privoxy's
570 There is also a web based editor that can be accessed from http://
571 config.privoxy.org/show-status/ (Shortcut: http://p.p/show-status/) for the
572 various actions files.
574 * default.filter (the filter file) can be used to re-write the raw page
575 content, including viewable text as well as embedded HTML and JavaScript,
576 and whatever else lurks on any given web page. The filtering jobs are only
577 pre-defined here; whether to apply them or not is up to the actions files.
579 All files use the "#" character to denote a comment (the rest of the line will
580 be ignored) angd understand line continuation through placing a backslash ("\")
581 as the very last character in a line. If the # is preceded by a backslash, it
582 looses its special function. Placing a # in front of an otherwise valid
583 configuration line to prevent it from being interpreted is called "commenting
586 The actions files and default.filter can use Perl style regular expressions for
589 After making any changes, there is no need to restart Privoxy in order for the
590 changes to take effect. Privoxy detects such changes automatically. Note,
591 however, that it may take one or two additional requests for the change to take
592 effect. When changing the listening address of Privoxy, these "wake up"
593 requests must obviously be sent to the old listening address.
595 While under development, the configuration content is subject to change. The
596 below documentation may not be accurate by the time you read this. Also, what
597 constitutes a "default" setting, may change, so please check all your
598 configuration files on important issues.
600 -------------------------------------------------------------------------------
602 8. The Main Configuration File
604 Again, the main configuration file is named config on Linux/Unix/BSD and OS/2,
605 and config.txt on Windows. Configuration lines consist of an initial keyword
606 followed by a list of values, all separated by whitespace (any number of spaces
607 or tabs). For example:
612 Assigns the value /etc/privoxy to the option confdir and thus indicates that
613 the configuration directory is named "/etc/privoxy/".
615 All options in the config file except for confdir and logdir are optional.
616 Watch out in the below description for what happens if you leave them unset.
618 The main config file controls all aspects of Privoxy's operation that are not
619 location dependent (i.e. they apply universally, no matter where you may be
622 -------------------------------------------------------------------------------
624 8.1. Configuration and Log File Locations
626 Privoxy can (and normally does) use a number of other files for additional
627 configuration, help and logging. This section of the configuration file tells
628 Privoxy where to find those other files.
630 -------------------------------------------------------------------------------
636 The directory where the other configuration files are located
644 /etc/privoxy (Unix) or Privoxy installation dir (Windows)
652 No trailing "/", please
654 When development goes modular and multi-user, the blocker, filter, and
655 per-user config will be stored in subdirectories of "confdir". For now, the
656 configuration directory structure is flat, except for confdir/templates,
657 where the HTML templates for CGI output reside (e.g. Privoxy's 404 error
660 -------------------------------------------------------------------------------
666 The directory where all logging takes place (i.e. where logfile and jarfile
675 /var/log/privoxy (Unix) or Privoxy installation dir (Windows)
683 No trailing "/", please
685 -------------------------------------------------------------------------------
691 The actions file(s) to use
695 File name, relative to confdir
699 standard # Internal purposes, recommended not editing
701 default # Main actions file
703 user # User customizations
707 No actions are taken at all. Simple neutral proxying.
711 Multiple actionsfile lines are permitted, and are in fact recommended!
713 The default values include standard.action, which is used for internal
714 purposes and should be loaded, default.action, which is the "main" actions
715 file maintained by the developers, and user.action, where you can make your
718 Actions files are where all the per site and per URL configuration is done
719 for ad blocking, cookie management, privacy considerations, etc. There is
720 no point in using Privoxy without at least one actions file.
722 -------------------------------------------------------------------------------
728 The filter file to use
732 File name, relative to confdir
736 default.filter (Unix) or default.filter.txt (Windows)
740 No textual content filtering takes place, i.e. all +filter{name} actions in
741 the actions files are turned off
745 The "default.filter" file contains content modification rules that use
746 "regular expressions". These rules permit powerful changes on the content
747 of Web pages, e.g., you could disable your favorite JavaScript annoyances,
748 re-write the actual displayed text, or just have some fun replacing
749 "Microsoft" with "MicroSuck" wherever it appears on a Web page.
751 -------------------------------------------------------------------------------
761 File name, relative to logdir
765 logfile (Unix) or privoxy.log (Windows)
769 No log file is used, all log messages go to the console (stderr).
773 The windows version will additionally log to the console.
775 The logfile is where all logging and error messages are written. The level
776 of detail and number of messages are set with the debug option (see below).
777 The logfile can be useful for tracking down a problem with Privoxy (e.g.,
778 it's not blocking an ad you think it should block) but in most cases you
779 probably will never look at it.
781 Your logfile will grow indefinitely, and you will probably want to
782 periodically remove it. On Unix systems, you can do this with a cron job
783 (see "man cron"). For Red Hat, a logrotate script has been included.
785 On SuSE Linux systems, you can place a line like "/var/log/privoxy.* +1024k
786 644 nobody.nogroup" in /etc/logfiles, with the effect that cron.daily will
787 automatically archive, gzip, and empty the log, when it exceeds 1M size.
789 -------------------------------------------------------------------------------
795 The file to store intercepted cookies in
799 File name, relative to logdir
803 jarfile (Unix) or privoxy.jar (Windows)
807 Intercepted cookies are not stored at all.
811 The jarfile may grow to ridiculous sizes over time.
813 -------------------------------------------------------------------------------
819 The trust file to use
823 File name, relative to confdir
827 Unset (commented out). When activated: trust (Unix) or trust.txt (Windows)
831 The whole trust mechanism is turned off.
835 The trust mechanism is an experimental feature for building white-lists and
836 should be used with care. It is NOT recommended for the casual user.
838 If you specify a trust file, Privoxy will only allow access to sites that
839 are named in the trustfile. You can also mark sites as trusted referrers
840 (with +), with the effect that access to untrusted sites will be granted,
841 if a link from a trusted referrer was used. The link target will then be
842 added to the "trustfile". Possible applications include limiting Internet
845 If you use + operator in the trust file, it may grow considerably over
848 -------------------------------------------------------------------------------
854 Location of the Privoxy User Manual.
858 A fully qualified URI
862 http://www.privoxy.org/user-manual/
866 The default will be used.
870 The User Manual is used for help hints from some of the internal CGI pages.
871 It is normally packaged with the binary distributions, and would make more
872 sense to have this pointed at a locally installed copy.
874 A more useful example (Unix):
876 user-manual file:///usr/share/doc/privoxy-2.9.14/user-manual/
878 -------------------------------------------------------------------------------
880 8.2. Local Set-up Documentation
882 If you intend to operate Privoxy for more users that just yourself, it might be
883 a good idea to let them know how to reach you, what you block and why you do
884 that, your policies etc.
886 -------------------------------------------------------------------------------
888 8.2.1. trust-info-url
892 A URL to be displayed in the error page that users will see if access to an
893 untrusted page is denied.
901 Two example URL are provided
905 No links are displayed on the "untrusted" error page.
909 The value of this option only matters if the experimental trust mechanism
910 has been activated. (See trustfile above.)
912 If you use the trust mechanism, it is a good idea to write up some on-line
913 documentation about your trust policy and to specify the URL(s) here. Use
914 multiple times for multiple URLs.
916 The URL(s) should be added to the trustfile as well, so users don't end up
917 locked out from the information on why they were locked out in the first
920 -------------------------------------------------------------------------------
926 An email address to reach the proxy administrator.
938 No email address is displayed on error pages and the CGI user interface.
942 If both admin-address and proxy-info-url are unset, the whole "Local
943 Privoxy Support" box on all generated pages will not be shown.
945 -------------------------------------------------------------------------------
947 8.2.3. proxy-info-url
951 A URL to documentation about the local Privoxy setup, configuration or
964 No link to local documentation is displayed on error pages and the CGI user
969 If both admin-address and proxy-info-url are unset, the whole "Local
970 Privoxy Support" box on all generated pages will not be shown.
972 This URL shouldn't be blocked ;-)
974 -------------------------------------------------------------------------------
978 These options are mainly useful when tracing a problem. Note that you might
979 also want to invoke Privoxy with the --no-daemon command line option when
982 -------------------------------------------------------------------------------
988 Key values that determine what information gets logged.
996 12289 (i.e.: URLs plus informational and warning messages)
1000 Nothing gets logged.
1004 The available debug levels are:
1006 debug 1 # show each GET/POST/CONNECT request
1007 debug 2 # show each connection status
1008 debug 4 # show I/O status
1009 debug 8 # show header parsing
1010 debug 16 # log all data into the logfile
1011 debug 32 # debug force feature
1012 debug 64 # debug regular expression filter
1013 debug 128 # debug fast redirects
1014 debug 256 # debug GIF de-animation
1015 debug 512 # Common Log Format
1016 debug 1024 # debug kill pop-ups
1017 debug 4096 # Startup banner and warnings.
1018 debug 8192 # Non-fatal errors
1020 To select multiple debug levels, you can either add them or use multiple
1023 A debug level of 1 is informative because it will show you each request as
1024 it happens. 1, 4096 and 8192 are highly recommended so that you will notice
1025 when things go wrong. The other levels are probably only of interest if you
1026 are hunting down a specific problem. They can produce a hell of an output
1029 The reporting of fatal errors (i.e. ones which crash Privoxy) is always on
1030 and cannot be disabled.
1032 If you want to use CLF (Common Log Format), you should set "debug 512" ONLY
1033 and not enable anything else.
1035 -------------------------------------------------------------------------------
1037 8.3.2. single-threaded
1041 Whether to run only one server thread
1053 Multi-threaded (or, where unavailable: forked) operation, i.e. the ability
1054 to serve multiple requests simultaneously.
1058 This option is only there for debug purposes and you should never need to
1059 use it. It will drastically reduce performance.
1061 -------------------------------------------------------------------------------
1063 8.4. Access Control and Security
1065 This section of the config file controls the security-relevant aspects of
1066 Privoxy's configuration.
1068 -------------------------------------------------------------------------------
1070 8.4.1. listen-address
1074 The IP address and TCP port on which Privoxy will listen for client
1087 Bind to localhost (127.0.0.1), port 8118. This is suitable and recommended
1088 for home users who run Privoxy on the same machine as their browser.
1092 You will need to configure your browser(s) to this proxy address and port.
1094 If you already have another service running on port 8118, or if you want to
1095 serve requests from other machines (e.g. on your local network) as well,
1096 you will need to override the default.
1098 If you leave out the IP address, Privoxy will bind to all interfaces
1099 (addresses) on your machine and may become reachable from the Internet. In
1100 that case, consider using access control lists (ACL's) (see "ACLs" below),
1105 Suppose you are running Privoxy on a machine which has the address
1106 192.168.0.1 on your local private network (192.168.0.0) and has another
1107 outside connection with a different address. You want it to serve requests
1110 listen-address 192.168.0.1:8118
1112 -------------------------------------------------------------------------------
1118 Initial state of "toggle" status
1130 Act as if toggled on
1134 If set to 0, Privoxy will start in "toggled off" mode, i.e. behave like a
1135 normal, content-neutral proxy. See enable-remote-toggle below. This is not
1136 really useful anymore, since toggling is much easier via the web interface
1137 than via editing the conf file.
1139 The windows version will only display the toggle icon in the system tray if
1140 this option is present.
1142 -------------------------------------------------------------------------------
1144 8.4.3. enable-remote-toggle
1148 Whether or not the web-based toggle feature may be used
1160 The web-based toggle feature is disabled.
1164 When toggled off, Privoxy acts like a normal, content-neutral proxy, i.e.
1165 it acts as if none of the actions applied to any URL.
1167 For the time being, access to the toggle feature can not be controlled
1168 separately by "ACLs" or HTTP authentication, so that everybody who can
1169 access Privoxy (see "ACLs" and listen-address above) can toggle it for all
1170 users. So this option is not recommended for multi-user environments with
1173 Note that you must have compiled Privoxy with support for this feature,
1174 otherwise this option has no effect.
1176 -------------------------------------------------------------------------------
1178 8.4.4. enable-edit-actions
1182 Whether or not the web-based actions file editor may be used
1194 The web-based actions file editor is disabled.
1198 For the time being, access to the editor can not be controlled separately
1199 by "ACLs" or HTTP authentication, so that everybody who can access Privoxy
1200 (see "ACLs" and listen-address above) can modify its configuration for all
1201 users. So this option is not recommended for multi-user environments with
1204 Note that you must have compiled Privoxy with support for this feature,
1205 otherwise this option has no effect.
1207 -------------------------------------------------------------------------------
1209 8.4.5. ACLs: permit-access and deny-access
1213 Who can access what.
1217 src_addr[/src_masklen] [dst_addr[/dst_masklen]]
1219 Where src_addr and dst_addr are IP addresses in dotted decimal notation or
1220 valid DNS names, and src_masklen and dst_masklen are subnet masks in CIDR
1221 notation, i.e. integer values from 2 to 30 representing the length (in
1222 bits) of the network address. The masks and the whole destination part are
1231 Don't restrict access further than implied by listen-address
1235 Access controls are included at the request of ISPs and systems
1236 administrators, and are not usually needed by individual users. For a
1237 typical home user, it will normally suffice to ensure that Privoxy only
1238 listens on the localhost or internal (home) network address by means of the
1239 listen-address option.
1241 Please see the warnings in the FAQ that this proxy is not intended to be a
1242 substitute for a firewall or to encourage anyone to defer addressing basic
1243 security weaknesses.
1245 Multiple ACL lines are OK. If any ACLs are specified, then the Privoxy
1246 talks only to IP addresses that match at least one permit-access line and
1247 don't match any subsequent deny-access line. In other words, the last match
1248 wins, with the default being deny-access.
1250 If Privoxy is using a forwarder (see forward below) for a particular
1251 destination URL, the dst_addr that is examined is the address of the
1252 forwarder and NOT the address of the ultimate target. This is necessary
1253 because it may be impossible for the local Privoxy to determine the IP
1254 address of the ultimate target (that's often what gateways are used for).
1256 You should prefer using IP addresses over DNS names, because the address
1257 lookups take time. All DNS names must resolve! You can not use domain
1258 patterns like "*.org" or partial domain names. If a DNS name resolves to
1259 multiple IP addresses, only the first one is used.
1261 Denying access to particular sites by ACL may have undesired side effects
1262 if the site in question is hosted on a machine which also hosts other
1267 Explicitly define the default behavior if no ACL and listen-address are
1268 set: "localhost" is OK. The absence of a dst_addr implies that all
1269 destination addresses are OK:
1271 permit-access localhost
1273 Allow any host on the same class C subnet as www.privoxy.org access to
1274 nothing but www.example.com:
1276 permit-access www.privoxy.org/24 www.example.com/32
1278 Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere,
1279 with the exception that 192.168.45.73 may not access
1280 www.dirty-stuff.example.com:
1282 permit-access 192.168.45.64/26
1283 deny-access 192.168.45.73 www.dirty-stuff.example.com
1285 -------------------------------------------------------------------------------
1291 Maximum size of the buffer for content filtering.
1303 Use a 4MB (4096 KB) limit.
1307 For content filtering, i.e. the +filter and +deanimate-gif actions, it is
1308 necessary that Privoxy buffers the entire document body. This can be
1309 potentially dangerous, since a server could just keep sending data
1310 indefinitely and wait for your RAM to exhaust -- with nasty consequences.
1313 When a document buffer size reaches the buffer-limit, it is flushed to the
1314 client unfiltered and no further attempt to filter the rest of the document
1315 is made. Remember that there may be multiple threads running, which might
1316 require up to buffer-limit Kbytes each, unless you have enabled
1317 "single-threaded" above.
1319 -------------------------------------------------------------------------------
1323 This feature allows routing of HTTP requests through a chain of multiple
1324 proxies. It can be used to better protect privacy and confidentiality when
1325 accessing specific domains by routing requests to those domains through an
1326 anonymous public proxy (see e.g. http://www.multiproxy.org/anon_list.htm) Or to
1327 use a caching proxy to speed up browsing. Or chaining to a parent proxy may be
1328 necessary because the machine that Privoxy runs on has no direct Internet
1331 Also specified here are SOCKS proxies. Privoxy supports the SOCKS 4 and SOCKS
1334 -------------------------------------------------------------------------------
1340 To which parent HTTP proxy specific requests should be routed.
1344 target_domain[:port] http_parent[/port]
1346 Where target_domain is a domain name pattern (see the chapter on domain
1347 matching in the default.action file), http_parent is the address of the
1348 parent HTTP proxy as an IP addresses in dotted decimal notation or as a
1349 valid DNS name (or "." to denote "no forwarding", and the optional port
1350 parameters are TCP ports, i.e. integer values from 1 to 64535
1358 Don't use parent HTTP proxies.
1362 If http_parent is ".", then requests are not forwarded to another HTTP
1363 proxy but are made directly to the web servers.
1365 Multiple lines are OK, they are checked in sequence, and the last match
1370 Everything goes to an example anonymizing proxy, except SSL on port 443
1371 (which it doesn't handle):
1373 forward .* anon-proxy.example.org:8080
1376 Everything goes to our example ISP's caching proxy, except for requests to
1379 forward .*. caching-proxy.example-isp.net:8000
1380 forward .example-isp.net .
1382 -------------------------------------------------------------------------------
1384 8.5.2. forward-socks4 and forward-socks4a
1388 Through which SOCKS proxy (and to which parent HTTP proxy) specific
1389 requests should be routed.
1393 target_domain[:port] socks_proxy[/port] http_parent[/port]
1395 Where target_domain is a domain name pattern (see the chapter on domain
1396 matching in the default.action file), http_parent and socks_proxy are IP
1397 addresses in dotted decimal notation or valid DNS names (http_parent may be
1398 "." to denote "no HTTP forwarding"), and the optional port parameters are
1399 TCP ports, i.e. integer values from 1 to 64535
1407 Don't use SOCKS proxies.
1411 Multiple lines are OK, they are checked in sequence, and the last match
1414 The difference between forward-socks4 and forward-socks4a is that in the
1415 SOCKS 4A protocol, the DNS resolution of the target hostname happens on the
1416 SOCKS server, while in SOCKS 4 it happens locally.
1418 If http_parent is ".", then requests are not forwarded to another HTTP
1419 proxy but are made (HTTP-wise) directly to the web servers, albeit through
1424 From the company example.com, direct connections are made to all "internal"
1425 domains, but everything outbound goes through their ISP's proxy by way of
1426 example.com's corporate SOCKS 4A gateway to the Internet.
1428 forward-socks4a .*. socks-gw.example.com:1080 www-cache.example-isp.net:8080
1429 forward .example.com .
1431 A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent
1434 forward-socks4 .*. socks-gw.example.com:1080 .
1436 -------------------------------------------------------------------------------
1438 8.5.3. Advanced Forwarding Examples
1440 If you have links to multiple ISPs that provide various special content only to
1441 their subscribers, you can configure multiple Privoxies which have connections
1442 to the respective ISPs to act as forwarders to each other, so that your users
1443 can see the internal content of all ISPs.
1445 Assume that host-a has a PPP connection to isp-a.net. And host-b has a PPP
1446 connection to isp-b.net. Both run Privoxy. Their forwarding configuration can
1452 forward .isp-b.net host-b:8118
1457 forward .isp-a.net host-a:8118
1459 Now, your users can set their browser's proxy to use either host-a or host-b
1460 and be able to browse the internal content of both isp-a and isp-b.
1462 If you intend to chain Privoxy and squid locally, then chain as browser ->
1463 squid -> privoxy is the recommended way.
1465 Assuming that Privoxy and squid run on the same box, your squid configuration
1466 could then look like this:
1468 # Define Privoxy as parent proxy (without ICP)
1469 cache_peer 127.0.0.1 parent 8118 7 no-query
1471 # Define ACL for protocol FTP
1474 # Do not forward FTP requests to Privoxy
1475 always_direct allow ftp
1477 # Forward all the rest to Privoxy
1478 never_direct allow all
1480 You would then need to change your browser's proxy settings to squid's address
1481 and port. Squid normally uses port 3128. If unsure consult http_port in
1484 -------------------------------------------------------------------------------
1486 8.6. Windows GUI Options
1488 Privoxy has a number of options specific to the Windows GUI interface:
1490 If "activity-animation" is set to 1, the Privoxy icon will animate when
1491 "Privoxy" is active. To turn off, set to 0.
1493 activity-animation 1
1496 If "log-messages" is set to 1, Privoxy will log messages to the console window:
1501 If "log-buffer-size" is set to 1, the size of the log buffer, i.e. the amount
1502 of memory used for the log messages displayed in the console window, will be
1503 limited to "log-max-lines" (see below).
1505 Warning: Setting this to 0 will result in the buffer to grow infinitely and eat
1511 log-max-lines is the maximum number of lines held in the log buffer. See above.
1516 If "log-highlight-messages" is set to 1, Privoxy will highlight portions of the
1517 log messages with a bold-faced font:
1519 log-highlight-messages 1
1522 The font used in the console window:
1524 log-font-name Comic Sans MS
1527 Font size used in the console window:
1532 "show-on-task-bar" controls whether or not Privoxy will appear as a button on
1533 the Task bar when minimized:
1538 If "close-button-minimizes" is set to 1, the Windows close button will minimize
1539 Privoxy instead of closing the program (close with the exit option on the File
1542 close-button-minimizes 1
1545 The "hide-console" option is specific to the MS-Win console version of Privoxy.
1546 If this option is used, Privoxy will disconnect from and hide the command
1552 -------------------------------------------------------------------------------
1556 The actions files are used to define what actions Privoxy takes for which URLs,
1557 and thus determines how ad images, cookies and various other aspects of HTTP
1558 content and transactions are handled, and on which sites (or even parts
1559 thereof). There are three such files included with Privoxy (as of version
1560 2.9.15), with differing purposes:
1562 * standard.action - is used by the web based editor, to set various
1563 pre-defined sets of rules for the default actions section in
1564 default.action. These have increasing levels of aggressiveness. It is not
1565 recommend to edit this file.
1567 * default.action - is the primary action file that sets the initial values
1568 for all actions. It is intended to provide a base level of functionality
1569 for Privoxy's array of features. So it is a set of broad rules that should
1570 work reasonably well for users everywhere. This is the file that the
1571 developers are keeping updated, and making available to users.
1573 * user.action - is intended to be for local site preferences and exceptions.
1574 As an example, if your ISP or your bank has specific requirements, and need
1575 special handling, this kind of thing should go here. This file will not be
1578 The list of actions files to be used are defined in the main configuration
1579 file, and are processed in the order they are defined. The content of these can
1580 all be viewed and edited from http://config.privoxy.org/show-status.
1582 An actions file typically has sections. Near the top, "aliases" are optionally
1583 defined (discussed below), then the default set of rules which will apply
1584 universally to all sites and pages. And then below that, exceptions to the
1585 defined universal policies.
1587 Actions can be used to block anything you want, including ads, banners, or just
1588 some obnoxious URL that you would rather not see. Cookies can be accepted or
1589 rejected, or accepted only during the current browser session (i.e. not written
1590 to disk), content can be modified, JavaScripts tamed, user-tracking fooled, and
1591 much more. See below for a complete list of actions.
1593 -------------------------------------------------------------------------------
1595 9.1. Finding the Right Mix
1597 Note that some actions, like cookie suppression or script disabling, may render
1598 some sites unusable that rely on these techniques to work properly. Finding the
1599 right mix of actions is not always easy and certainly a matter of personal
1600 taste. In general, it can be said that the more "aggressive" your default
1601 settings (in the top section of the actions file) are, the more exceptions for
1602 "trusted" sites you will have to make later. If, for example, you want to kill
1603 popup windows per default, you'll have to make exceptions from that rule for
1604 sites that you regularly use and that require popups for actually useful
1605 content, like maybe your bank, favorite shop, or newspaper.
1607 We have tried to provide you with reasonable rules to start from in the
1608 distribution actions files. But there is no general rule of thumb on these
1609 things. There just are too many variables, and sites are constantly changing.
1610 Sooner or later you will want to change the rules (and read this chapter again
1613 -------------------------------------------------------------------------------
1617 The easiest way to edit the "actions" files is with a browser by using our
1618 browser-based editor, which can be reached from http://config.privoxy.org/
1621 If you prefer plain text editing to GUIs, you can of course also directly edit
1622 the the actions files.
1624 -------------------------------------------------------------------------------
1626 9.3. How Actions are Applied to URLs
1628 Actions files are divided into sections. There are special sections, like the "
1629 alias" sections which will be discussed later. For now let's concentrate on
1630 regular sections: They have a heading line (often split up to multiple lines
1631 for readability) which consist of a list of actions, separated by whitespace
1632 and enclosed in curly braces. Below that, there is a list of URL patterns, each
1635 To determine which actions apply to a request, the URL of the request is
1636 compared to all patterns in this file. Every time it matches, the list of
1637 applicable actions for the URL is incrementally updated, using the heading of
1638 the section in which the pattern is located. If multiple matches for the same
1639 URL set the same action differently, the last match wins. If not, the effects
1640 are aggregated (e.g. a URL might match both the "+handle-as-image" and "+block"
1643 You can trace this process by visiting http://config.privoxy.org/show-url-info.
1645 More detail on this is provided in the Appendix, Anatomy of an Action.
1647 -------------------------------------------------------------------------------
1651 Generally, a pattern has the form <domain>/<path>, where both the <domain> and
1652 <path> are optional. (This is why the pattern / matches all URLs).
1656 is a domain-only pattern and will match any request to www.example.com,
1657 regardless of which document on that server is requested.
1661 means exactly the same. For domain-only patterns, the trailing / may be
1664 www.example.com/index.html
1666 matches only the single document /index.html on www.example.com.
1670 matches the document /index.html, regardless of the domain, i.e. on any web
1675 matches nothing, since it would be interpreted as a domain name and there
1676 is no top-level domain called .html.
1678 -------------------------------------------------------------------------------
1680 9.4.1. The Domain Pattern
1682 The matching of the domain part offers some flexible options: if the domain
1683 starts or ends with a dot, it becomes unanchored at that end. For example:
1687 matches any domain that ENDS in .example.com
1691 matches any domain that STARTS with www.
1695 matches any domain that CONTAINS .example. (Correctly speaking: It matches
1696 any FQDN that contains example as a domain.)
1698 Additionally, there are wild-cards that you can use in the domain names
1699 themselves. They work pretty similar to shell wild-cards: "*" stands for zero
1700 or more arbitrary characters, "?" stands for any single character, you can
1701 define character classes in square brackets and all of that can be freely
1706 matches "adserver.example.com", "ads.example.com", etc but not
1711 matches all of the above, and then some.
1715 matches www.ipix.com, pictures.epix.com, a.b.c.d.e.upix.com etc.
1717 www[1-9a-ez].example.c*
1719 matches www1.example.com, www4.example.cc, wwwd.example.cy,
1720 wwwz.example.com etc., but not wwww.example.com.
1722 -------------------------------------------------------------------------------
1724 9.4.2. The Path Pattern
1726 Privoxy uses Perl compatible regular expressions (through the PCRE library) for
1729 There is an Appendix with a brief quick-start into regular expressions, and
1730 full (very technical) documentation on PCRE regex syntax is available on-line
1731 at http://www.pcre.org/man.txt. You might also find the Perl man page on
1732 regular expressions (man perlre) useful, which is available on-line at http://
1733 www.perldoc.com/perl5.6/pod/perlre.html.
1735 Note that the path pattern is automatically left-anchored at the "/", i.e. it
1736 matches as if it would start with a "^" (regular expression speak for the
1737 beginning of a line).
1739 Please also note that matching in the path is case INSENSITIVE by default, but
1740 you can switch to case sensitive at any point in the pattern by using the "(?
1741 -i)" switch: www.example.com/(?-i)PaTtErN.* will match only documents whose
1742 path starts with PaTtErN in exactly this capitalization.
1744 -------------------------------------------------------------------------------
1748 All actions are disabled by default, until they are explicitly enabled
1749 somewhere in an actions file. Actions are turned on if preceded with a "+", and
1750 turned off if preceded with a "-". So a "+action" means "do that action", e.g.
1751 "+block" means please "block the following URL patterns".
1753 Actions are invoked by enclosing the action name in curly braces (e.g.
1754 {+some_action}), followed by a list of URLs (or patterns that match URLs) to
1755 which the action applies. There are three classes of actions:
1757 * Boolean, i.e the action can only be "on" or "off". Examples:
1759 {+name} # enable this action
1760 {-name} # disable this action
1763 * Parameterized, e.g. "+/-hide-user-agent{ Mozilla 1.0 }", where some value
1764 is required in order to enable this type of action. Examples:
1766 {+name{param}} # enable action and set parameter to "param"
1767 {-name} # disable action ("parameter") can be omitted
1770 * Multi-value, e.g. "{+/-add-header{Name: value}}" or "{+/-send-wafer{name=
1771 value}}"), where some value needs to be defined in addition to simply
1772 enabling the action. Examples:
1774 {+name{param=value}} # enable action and set "param" to "value"
1775 {-name{param=value}} # remove the parameter "param" completely
1776 {-name} # disable this action totally and remove param too
1779 If nothing is specified in any actions file, no "actions" are taken. So in this
1780 case Privoxy would just be a normal, non-blocking, non-anonymizing proxy. You
1781 must specifically enable the privacy and blocking features you need (although
1782 the provided default actions files will give a good starting point).
1784 Later defined actions always over-ride earlier ones. So exceptions to any rules
1785 you make, should come in the latter part of the file (or in a file that is
1786 processed later when using multiple actions files). For multi-valued actions,
1787 the actions are applied in the order they are specified. Actions files are
1788 processed in the order they are defined in config (the default installation has
1789 three actions files). It also quite possible for any given URL pattern to match
1790 more than one action!
1792 The list of valid Privoxy "actions" are:
1794 -------------------------------------------------------------------------------
1804 Send a user defined HTTP header to the web server.
1808 Any value is possible. Validity of the defined HTTP headers is not checked.
1812 {+add-header{X-User-Tracking: sucks}}
1818 This action may be specified multiple times, in order to define multiple
1819 headers. This is rarely needed for the typical user. If you don't know what
1820 "HTTP headers" are, you definitely don't need to worry about this one.
1822 -------------------------------------------------------------------------------
1832 Used to block a URL from reaching your browser. The URL may be anything,
1833 but is typically used to block ads or other obnoxious content.
1842 .banners.example.com
1848 If a URL matches one of the blocked patterns, Privoxy will intercept the
1849 URL and display its special "BLOCKED" page instead. If there is sufficient
1850 space, a large red banner will appear with a friendly message about why the
1851 page was blocked, and a way to go there anyway. If there is insufficient
1852 space a smaller "BLOCKED" page will appear without the red banner. Click
1853 here to view the default blocked HTML page (Privoxy must be running for
1854 this to work as intended!).
1856 A very important exception is if the URL matches both "+block" and
1857 "+handle-as-image", then it will be handled by "+set-image-blocker" (see
1858 below). It is important to understand this process, in order to understand
1859 how Privoxy is able to deal with ads and other objectionable content.
1861 The "+filter" action can also perform some of the same functionality as
1862 "+block", but by virtue of very different programming techniques, and is
1863 most often used for different reasons.
1865 -------------------------------------------------------------------------------
1867 9.5.3. +deanimate-gifs
1875 To stop those annoying, distracting animated GIF images.
1883 {+deanimate-gifs{last}}
1889 De-animate all animated GIF images, i.e. reduce them to their last frame.
1890 This will also shrink the images considerably (in bytes, not pixels!). If
1891 the option "first" is given, the first frame of the animation is used as
1892 the replacement. If "last" is given, the last frame of the animation is
1893 used instead, which probably makes more sense for most banner animations,
1894 but also has the risk of not showing the entire last frame (if it is only a
1895 delta to an earlier frame).
1897 -------------------------------------------------------------------------------
1899 9.5.4. +downgrade-http-version
1907 "+downgrade-http-version" will downgrade HTTP/1.1 client requests to HTTP/
1908 1.0 and downgrade the responses as well.
1916 {+downgrade-http-version}
1922 Use this action for servers that use HTTP/1.1 protocol features that
1923 Privoxy doesn't handle well yet. HTTP/1.1 is only partially implemented.
1924 Default is not to downgrade requests. This is an infrequently needed
1925 action, and is used to help with rare problem sites only.
1927 -------------------------------------------------------------------------------
1929 9.5.5. +fast-redirects
1937 The "+fast-redirects" action enables interception of "redirect" requests
1938 from one server to another, which are used to track users.Privoxy can cut
1939 off all but the last valid URL in a redirect request and send a local
1940 redirect back to your browser without contacting the intermediate site(s).
1954 Many sites, like yahoo.com, don't just link to other sites. Instead, they
1955 will link to some script on their own server, giving the destination as a
1956 parameter, which will then redirect you to the final target. URLs resulting
1957 from this scheme typically look like: http://some.place/some_script?http://
1960 Sometimes, there are even multiple consecutive redirects encoded in the
1961 URL. These redirections via scripts make your web browsing more traceable,
1962 since the server from which you follow such a link can see where you go to.
1963 Apart from that, valuable bandwidth and time is wasted, while your browser
1964 ask the server for one redirect after the other. Plus, it feeds the
1967 This is a normally "on" feature, and often requires exceptions for sites
1968 that are sensitive to defeating this mechanism.
1970 -------------------------------------------------------------------------------
1980 Apply page filtering as defined by named sections of the default.filter
1981 file to the specified site(s). "Filtering" can be any modification of the
1982 raw page content, including re-writing or deletion of content.
1986 "+filter" must include the name of one of the section identifiers from
1987 default.filter (or whatever filterfile is specified in config).
1989 Example usage (from the current default.filter):
1991 +filter{html-annoyances}: Get rid of particularly annoying HTML abuse.
1993 +filter{js-annoyances}: Get rid of particularly annoying JavaScript abuse
1995 +filter{content-cookies}: Kill cookies that come in the HTML or JS content
1997 +filter{popups}: Kill all popups in JS and HTML
1999 +filter{frameset-borders}: Give frames a border and make them resizable
2001 +filter{webbugs}: Squish WebBugs (1x1 invisible GIFs used for user
2004 +filter{refresh-tags}: Kill automatic refresh tags (for dial-on-demand
2007 +filter{fun}: Text replacements for subversive browsing fun!
2009 +filter{nimda}: Remove Nimda (virus) code.
2011 +filter{banners-by-size}: Kill banners by size (very efficient!)
2013 +filter{shockwave-flash}: Kill embedded Shockwave Flash objects
2015 +filter{crude-parental}: Kill all web pages that contain the words "sex" or
2020 This is potentially a very powerful feature! And requires a knowledge of
2021 regular expressions if you want to "roll your own". Filtering operates on a
2022 line by line basis throughout the entire page.
2024 Filtering requires buffering the page content, which may appear to slow
2025 down page rendering since nothing is displayed until all content has passed
2026 the filters. (It does not really take longer, but seems that way since the
2027 page is not incrementally displayed.) This effect will be more noticeable
2028 on slower connections.
2030 Filtering can achieve some of the effects as the "+block" action, i.e. it
2031 can be used to block ads and banners. In the overall scheme of things,
2032 filtering is one of the first things "Privoxy" does with a web page. So
2033 other most other actions are applied to the already "filtered" page.
2035 -------------------------------------------------------------------------------
2037 9.5.7. +hide-forwarded-for-headers
2045 Block any existing X-Forwarded-for HTTP header, and do not add a new one.
2053 {+hide-forwarded-for-headers}
2059 It is fairly safe to leave this on. It does not seem to break many sites.
2061 -------------------------------------------------------------------------------
2063 9.5.8. +hide-from-header
2071 To block the browser from sending your email address in a "From:" header.
2075 Keyword: "block", or any user defined value.
2079 {+hide-from-header{block}}
2085 The keyword "block" will completely remove the header (not to be confused
2086 with the "+block" action). Alternately, you can specify any value you
2087 prefer to send to the web server.
2089 -------------------------------------------------------------------------------
2091 9.5.9. +hide-referer
2099 Don't send the "Referer:" (sic) HTTP header to the web site. Or,
2100 alternately send a forged header instead.
2104 Prevent the header from being sent with the keyword, "block". Or, "forge" a
2105 URL to one from the same server as the request. Or, set to user defined
2106 value of your choice.
2110 {+hide-referer{forge}}
2116 "forge" is the preferred option here, since some servers will not send
2117 images back otherwise.
2119 "+hide-referrer" is an alternate spelling of "+hide-referer". It has the
2120 exact same parameters, and can be freely mixed with, "+hide-referer".
2121 ("referrer" is the correct English spelling, however the HTTP specification
2122 has a bug - it requires it to be spelled as "referer".)
2124 -------------------------------------------------------------------------------
2126 9.5.10. +hide-user-agent
2134 To change the "User-Agent:" header so web servers can't tell your browser
2135 type. Who's business is it anyway?
2139 Any user defined string.
2143 {+hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}}
2149 Warning! This breaks many web sites that depend on this in order to
2150 determine how the target browser will respond to various requests. Use with
2153 -------------------------------------------------------------------------------
2155 9.5.11. +handle-as-image
2163 To define what Privoxy should treat automatically as an image, and is an
2164 important ingredient of how ads are handled.
2173 /.*\.(gif|jpg|jpeg|png|bmp|ico)
2178 This only has meaning if the URL (or pattern) also is "+block"ed, in which
2179 case a user definable image can be sent rather than a HTML page. This is
2180 integral to the whole concept of ad blocking: the URL must match both a
2181 "+block" rule, and "+handle-as-image". (See "+set-image-blocker" below for
2182 control over what will actually be displayed by the browser.)
2184 There is little reason to change the default definition for this action.
2186 -------------------------------------------------------------------------------
2188 9.5.12. +set-image-blocker
2196 Decide what to do with URLs that end up tagged with both "+block" and
2197 "+handle-as-image", e.g an advertisement.
2201 There are four available options: "-set-image-blocker" will send a HTML
2202 "blocked" page, usually resulting in a "broken image" icon.
2203 "+set-image-blocker{blank}" will send a 1x1 transparent GIF image.
2204 "+set-image-blocker{pattern}" will send a checkerboard type pattern (the
2205 default). And finally, "+set-image-blocker{http://xyz.com}" will send a
2206 HTTP temporary redirect to the specified image. This has the advantage of
2207 the icon being being cached by the browser, which will speed up the
2212 {+set-image-blocker{blank}}
2218 If you want invisible ads, they need to meet criteria as matching both
2219 images and blocked actions. And then, "image-blocker" should be set to
2220 "blank" for invisibility. Note you cannot treat HTML pages as images in
2221 most cases. For instance, frames require an HTML page to display. So a
2222 frame that is an ad, typically cannot be treated as an image. Forcing an
2223 "image" in this situation just will not work reliably.
2225 -------------------------------------------------------------------------------
2227 9.5.13. +limit-connect
2235 By default, Privoxy only allows HTTP CONNECT requests to port 443 (the
2236 standard, secure HTTPS port). Use "+limit-connect" to disable this
2237 altogether, or to allow more ports.
2241 Any valid port number, or port number range.
2245 +limit-connect{443} #
2246 This is the default and need not be specified.
2247 +limit-connect{80,443} # Ports 80 and 443 are OK.
2248 +limit-connect{-3, 7, 20-100, 500-} #
2249 Port less than 3, 7, 20 to 100 and above 500 are OK.
2254 The CONNECT methods exists in HTTP to allow access to secure websites
2255 (https:// URLs) through proxies. It works very simply: the proxy connects
2256 to the server on the specified port, and then short-circuits its
2257 connections to the client and to the remote proxy. This can be a big
2258 security hole, since CONNECT-enabled proxies can be abused as TCP relays
2261 If you want to allow CONNECT for more ports than this, or want to forbid
2262 CONNECT altogether, you can specify a comma separated list of ports and
2263 port ranges (the latter using dashes, with the minimum defaulting to 0 and
2266 If you don't know what any of this means, there probably is no reason to
2269 -------------------------------------------------------------------------------
2271 9.5.14. +prevent-compression
2279 Prevent the specified websites from compressing HTTP data.
2287 {+prevent-compression}
2293 Some websites do this, which can be a problem for Privoxy, since "+filter",
2294 "+kill-popups" and "+gif-deanimate" will not work on compressed data. This
2295 will slow down connections to those websites, though. Default typically is
2296 to turn "prevent-compression" on.
2298 -------------------------------------------------------------------------------
2300 9.5.15. +session-cookies-only
2308 Allow cookies for the current browser session only.
2314 Example usage (disabling):
2316 {-session-cookies-only}
2322 If websites set cookies, "+session-cookies-only" will make sure they are
2323 erased when you exit and restart your web browser. This makes profiling
2324 cookies useless, but won't break sites which require cookies so that you
2325 can log in for transactions. This is generally turned on for all sites, and
2326 is the recommended setting.
2328 "+prevent-*-cookies" actions should be turned off as well (see below), for
2329 "+session-cookies-only" to work. Or, else no cookies will get through at
2330 all. For, "persistent" cookies that survive across browser sessions, see
2333 -------------------------------------------------------------------------------
2335 9.5.16. +prevent-reading-cookies
2343 Explicitly prevent the web server from reading any cookies on your system.
2351 {+prevent-reading-cookies}
2357 Often used in conjunction with "+prevent-setting-cookies" to disable
2358 cookies completely. Note that "+session-cookies-only" requires these to
2359 both be disabled (or else it never gets any cookies to cache).
2361 For "persistent" cookies to work (i.e. they survive across browser sessions
2362 and reboots), all three cookie settings should be "off" for the specified
2365 -------------------------------------------------------------------------------
2367 9.5.17. +prevent-setting-cookies
2375 Explicitly block the web server from storing cookies on your system.
2383 {+prevent-setting-cookies}
2389 Often used in conjunction with "+prevent-reading-cookies" to disable
2390 cookies completely (see above).
2392 -------------------------------------------------------------------------------
2394 9.5.18. +kill-popups
2402 Stop those annoying JavaScript pop-up windows!
2416 "+kill-popups" uses a built in filter to disable pop-ups that use the
2417 window.open() function, etc. This is one of the first actions processed by
2418 Privoxy as it contacts the remote web server. This action is not always
2419 100% reliable, and is supplemented by "+filter{popups}".
2421 -------------------------------------------------------------------------------
2423 9.5.19. +send-vanilla-wafer
2431 Sends a cookie for every site stating that you do not accept any copyright
2432 on cookies sent to you, and asking them not to track you.
2440 {+send-vanilla-wafer}
2446 This action only applies if you are using a jarfile for saving cookies. Of
2447 course, this is a (relatively) unique header and could conceivably be used
2450 -------------------------------------------------------------------------------
2460 This allows you to send an arbitrary, user definable cookie.
2464 User specified cookie name and corresponding value.
2468 {+send-wafer{name=value}}
2474 This can be specified multiple times in order to add as many cookies as you
2477 -------------------------------------------------------------------------------
2481 Note that many of these actions have the potential to cause a page to
2482 misbehave, possibly even not to display at all. There are many ways a site
2483 designer may choose to design his site, and what HTTP header content, and other
2484 criteria, he may depend on. There is no way to have hard and fast rules for all
2485 sites. See the Appendix for a brief example on troubleshooting actions.
2487 -------------------------------------------------------------------------------
2489 9.5.22. Sample Actions Files
2491 Remember that the meaning of any of the above references is reversed by
2492 preceding the action with a "-", in place of the "+". Also, that some actions
2493 are turned on in the default section of the actions file, and require little to
2494 no additional configuration. These are just "on".
2496 But, other actions that are turned on in the default section do typically
2497 require exceptions to be listed in the latter sections of one of our actions
2498 file. For instance, by default no URLs are "blocked" (i.e. in the default
2499 definitions of default.action). We need exceptions to this in order to enable
2500 ad blocking in the lower sections. But we need to be very selective about what
2501 we do block. Thus, the default is "off" for blocking.
2503 Below is a liberally commented sample default.action file to demonstrate how
2504 all the pieces come together. And to show how exceptions to the default
2505 policies can be handled. This is followed by a brief user.action with similar
2508 # Sample default.action file <developers@privoxy.org>
2510 # Settings -- Don't change! For internal Privoxy use ONLY.
2512 for-privoxy-version=3.0
2515 ##########################################################################
2516 # Aliases must be defined *before* they are used. These are
2517 # easier to remember, and can combine several actions into one. Once
2518 # defined they can be used just like any built-in action -- but within
2519 # this file only! Aliases do not require a + or - sign.
2520 ##########################################################################
2522 # Some useful aliases.
2523 # Alias to turn off cookie handling, ie allow all cookies unmolested.
2524 -prevent-cookies = -prevent-setting-cookies -prevent-reading-cookies \
2525 -session-cookies-only
2527 # Alias to both block and treat as if an image for ad blocking
2529 +imageblock = +block +handle-as-image
2531 # Fragile sites should have the minimum changes:
2532 fragile = -block -deanimate-gifs -fast-redirects -filter -hide-referer \
2533 -prevent-cookies -kill-popups
2535 # Shops should be allowed to set persistent cookies
2536 shop = -filter -prevent-cookies -session-cookies-only
2539 ##########################################################################
2540 # Begin default action settings. Anything in this section will match
2541 # all URLs -- UNLESS we have exceptions that also match, defined below this
2542 # section. We will show all potential actions here whether they are on
2543 # or off. We could omit any disabled action if we wanted, since all
2544 # actions are 'off' by default anyway. Shown for completeness only.
2545 # Actions are enabled if preceded by a '+', otherwise they are disabled
2546 # (unless an alias has been defined without this).
2547 ##########################################################################
2552 -downgrade-http-version \
2554 +filter{html-annoyances} \
2555 +filter{js-annoyances} \
2556 -filter{content-cookies} \
2559 -filter{refresh-tags} \
2562 +filter{banners-by-size} \
2563 -filter{shockwave-flash} \
2564 -filter{crude-prental} \
2565 +hide-forwarded-for-headers \
2566 +hide-from-header{block} \
2570 +set-image-blocker{pattern} \
2572 +prevent-compression \
2573 -session-cookies-only \
2574 -prevent-reading-cookies \
2575 -prevent-setting-cookies \
2577 -send-vanilla-wafer \
2580 / # forward slash will match *all* potential URL patterns.
2582 ##########################################################################
2583 # Default behavior is now set. Now we will define some exceptions to our
2584 # default action policies.
2585 ##########################################################################
2587 # These sites are very complex and require very minimal interference.
2588 # We'll disable most actions with our 'fragile' alias:
2590 .office.microsoft.com # surprise, surprise!
2591 .windowsupdate.microsoft.com
2594 # Shopping sites - not as fragile but require some special
2595 # handling. We still want to block ads, and we will allow
2596 # persistant cookies via the 'shop' alias:
2599 .worldpay.com # for quietpc.com
2604 # These sites require pop-ups too :( We'll combine our 'shop'
2605 # alias with two other actions into one rule to allow all popups.
2606 { shop -kill-popups -filter{popups} }
2611 # The 'Fast-redirects' action breaks some sites. Disable this action
2612 # for these known sensitive sites:
2615 edit.europe.yahoo.com
2617 .altavista.com/.*(like|url|link):http
2618 .altavista.com/trans.*urltext=http
2622 # Define which file types will be treated as images. Important
2624 { +handle-as-image }
2625 /.*\.(gif|jpe?g|png|bmp|ico)
2628 # Now lets list some domains that are known ad generators. And
2629 # our alias that we use here will block these as well as force
2630 # them to be treated as images. This combination of actions is
2631 # important for ad blocking. What the browser will show instead is
2632 # determined by the setting of "+set-image-blocker"
2636 .a.yimg.com/(?:(?!/i/).)*$
2637 .a[0-9].yimg.com/(?:(?!/i/).)*$
2641 ad.*.doubleclick.net
2644 # These will just simply be blocked. They will generate the BLOCKED
2645 # banner page, if matched. Heavy use of wildcards and regular
2646 # expressions in this example. Enable block action:
2652 /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
2653 /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
2657 # The above block section will probably inadvertantly catch some
2658 # sites we DO NOT want blocked via the wildcards and regular expressions.
2659 # Now let's set exceptions to the exceptions so the good guys get better
2660 # treatment. Disable block action:
2666 # Let's just trust all .edu top level domains.
2668 www.ugu.com/sui/ugu/adv
2669 # We'll need to access to path names containing 'download'
2672 # 'adv' is for globalintersec and means advanced, not advertisement
2673 www.globalintersec.com/adv
2676 # Don't filter *anything* from our friends at sourceforge.
2677 # Notice we don't have to name the individual filter
2678 # identifiers -- we just turn them all off in one fell swoop.
2679 # Disable all filters for this one site:
2684 So far we are painting with a broad brush by setting general policies. The
2685 above would be a reasonable starting point for many situations. Now, we want to
2686 be more specific and have customized rules that are more suitable to our
2687 personal habits and preferences. These would be for narrowly defined situations
2688 like your ISP or your bank, and should be placed in user.action, which is
2689 parsed after all other actions files and should not be clobbered by upgrades.
2690 So any settings here, will have the last word and over-ride any previously
2693 Now a few examples of some things that one might do with a user.action file.
2695 # Sample user.action file.
2697 # Any aliases you want to use need to be re-defined here.
2698 # Alias to turn off cookie handling, ie allow all cookies unmolested.
2699 -prevent-cookies = -prevent-setting-cookies -prevent-reading-cookies \
2700 -session-cookies-only
2702 # Fragile sites should have the minimum changes:
2703 fragile = -block -deanimate-gifs -fast-redirects -filter -hide-referer \
2704 -prevent-cookies -kill-popups
2706 # Allow persistent cookies for a few regular sites that we
2707 # trust via our above alias. These will be saved from one browser session
2708 # to the next. We are explicity turning off any and all cookie handling,
2709 # even though the prevent-*-cookie settings were disabled in our above
2710 # default.action anyway. So cookies from these domains will come through
2712 { -prevent-cookies }
2719 # My ISP uses obnoxious self promoting images on many pages.
2720 # Nuke them :) Note that "+handle-as-image" need not be specified,
2721 # since all URLs ending in .gif will be tagged as images by the
2722 # general rules in default.action anyway.
2724 www.my-isp-example.com/logo[0-9].gif
2727 # Say the site where you do your homebanking needs to open
2728 # popup windows, but you have chosen to kill popups by
2729 # default. This will allow it for your-example-bank.com:
2731 { -filter{popups} -kill-popups }
2732 .my-example-bank.com
2735 # This site is delicate, and requires kid-glove
2741 -------------------------------------------------------------------------------
2745 Custom "actions", known to Privoxy as "aliases", can be defined by combining
2746 other "actions". These can in turn be invoked just like the built-in "actions".
2747 Currently, an alias can contain any character except space, tab, "=", "{" or "}
2748 ". But please use only "a"- "z", "0"-"9", "+", and "-". Alias names are not
2749 case sensitive, and must be defined before other actions in the actions file!
2750 And there can only be one set of "aliases" defined per file. Each actions file
2751 may have its own aliases, but they are only visible within that file. Aliases
2752 do not requir a "+" or "-" sign in front, since they are merely expanded.
2754 Now let's define a few aliases:
2756 # Useful custom aliases we can use later. These must come first!
2758 +prevent-cookies = +prevent-setting-cookies +prevent-reading-cookies
2759 -prevent-cookies = -prevent-setting-cookies -prevent-reading-cookies
2761 -block -prevent-cookies -filter -fast-redirects -hide-referer -kill-popups
2762 shop = -prevent-cookies -filter -fast-redirects
2763 +imageblock = +block +handle-as-image
2765 # Aliases defined from other aliases, for people who don't like to type
2767 c0 = +prevent-cookies
2768 c1 = -prevent-cookies
2769 #... etc. Customize to your heart's content.
2772 Some examples using our "shop" and "fragile" aliases from above. These would
2773 appear in the lower sections of an actions file as exceptions to the default
2774 actions (as defined in the upper section):
2776 # These sites are very complex and require
2777 # minimal interference.
2779 .office.microsoft.com
2780 .windowsupdate.microsoft.com
2783 # Shopping sites - but we still want to block ads.
2786 .worldpay.com # for quietpc.com
2789 # These shops require pop-ups also
2795 The "shop" and "fragile" aliases are often used for "problem" sites that
2796 require most actions to be disabled in order to function properly.
2798 -------------------------------------------------------------------------------
2802 Any web page can be dynamically modified with the filter file. This
2803 modification can be removal, or re-writing, of any web page content, including
2804 tags and non-visible content. The default filter file is oddly enough
2805 default.filter, located in the config directory.
2807 This is potentially a very powerful feature, and requires knowledge of both
2808 "regular expression" and HTML in order create custom filters. But, there are a
2809 number of useful filters included with Privoxy for many common situations.
2811 The included example file is divided into sections. Each section begins with
2812 the FILTER keyword, followed by the identifier for that section, e.g. "FILTER:
2813 webbugs". Each section performs a similar type of filtering, such as
2816 This file uses regular expressions to alter or remove any string in the target
2817 page. The expressions can only operate on one line at a time. Some examples
2818 from the included default default.filter:
2820 Stop web pages from displaying annoying messages in the status bar by deleting
2823 FILTER: html-annoyances
2825 # New browser windows should be resizeable and have a location and status
2828 s/resizable="?(no|0)"?/resizable=1/ig s/noresize/yesresize/ig
2829 s/location="?(no|0)"?/location=1/ig s/status="?(no|0)"?/status=1/ig
2830 s/scrolling="?(no|0|Auto)"?/scrolling=1/ig
2831 s/menubar="?(no|0)"?/menubar=1/ig
2833 # The <BLINK> tag was a crime!
2835 s*<blink>|</blink>**ig
2839 #s/framespacing="?(no|0)"?//ig
2840 #s/margin(height|width)=[0-9]*//gi
2843 Just for kicks, replace any occurrence of "Microsoft" with "MicroSuck", and
2844 have a little fun with topical buzzwords:
2848 s/microsoft(?!.com)/MicroSuck/ig
2852 s/industry-leading|cutting-edge|award-winning/<font color=red><b>BINGO!</b></
2856 Kill those pesky little web-bugs:
2858 # webbugs: Squish WebBugs (1x1 invisible GIFs used for user tracking)
2861 s/<img\s+[^>]*?(width|height)\s*=\s*['"]?1\D[^>]*?(width|height)\s*=\s*['"]?1
2862 (\D[^>]*?)?>/<!-- Squished WebBug -->/sig
2865 -------------------------------------------------------------------------------
2867 10.1. The +filter Action
2869 Filters are enabled with the "+filter" action from within one of the actions
2870 files. "+filter" requires one parameter, which should match one of the section
2871 identifiers in the filter file itself. Example:
2873 +filter{html-annoyances}
2875 This would activate that particular filter. Similarly, "+filter" can be turned
2876 off for selected sites as: "-filter{html-annoyances}". Remember too, all
2877 actions are off by default, unless they are explicity enabled in one of the
2880 -------------------------------------------------------------------------------
2884 When Privoxy displays one of its internal pages, such as a 404 Not Found error
2885 page (Privoxy must be running for link to work as intended), it uses the
2886 appropriate template. On Linux, BSD, and Unix, these are located in /etc/
2887 privoxy/templates by default. These may be customized, if desired.
2888 cgi-style.css is used to control the HTML attributes (fonts, etc).
2890 The default Blocked (Privoxy needs to be running for page to display) banner
2891 page with the bright red top banner, is called just "blocked". This may be
2892 customized or replaced with something else if desired.
2894 -------------------------------------------------------------------------------
2896 12. Contacting the Developers, Bug Reporting and Feature Requests
2898 We value your feedback. However, to provide you with the best support, please
2899 note the following sections.
2901 -------------------------------------------------------------------------------
2905 To get support, use the Sourceforge Support Forum:
2907 http://sourceforge.net/tracker/?group_id=11118&atid=211118
2909 -------------------------------------------------------------------------------
2913 To submit bugs, use the Sourceforge Bug Forum:
2915 http://sourceforge.net/tracker/?group_id=11118&atid=111118.
2917 Make sure that the bug has not already been submitted. Please try to verify
2918 that it is a Privoxy bug, and not a browser or site bug first. If you are using
2919 your own custom configuration, please try the stock configs to see if the
2920 problem is a configuration related bug. And if not using the latest development
2921 snapshot, please try the latest one. Or even better, CVS sources. Please be
2922 sure to include the Privoxy version, platform, browser, any pertinent log data,
2923 any other relevant details (please be specific) and, if possible, some way to
2926 -------------------------------------------------------------------------------
2928 12.3. Request new features
2930 To submit ideas on new features, use the Sourceforge feature request forum:
2932 http://sourceforge.net/tracker/?atid=361118&group_id=11118&func=browse.
2934 -------------------------------------------------------------------------------
2936 12.4. Report ads or other filter problems
2938 You can also send feedback on websites that Privoxy has problems with. Please
2939 bookmark the following link: "Privoxy - Submit Filter Feedback". Once you surf
2940 to a page with problems, use the bookmark to send us feedback. We will look
2941 into the issue as soon as possible.
2943 New, improved default.action files will occasionally be made available based on
2944 your feedback. These will be announced on the ijbswa-announce list.
2946 -------------------------------------------------------------------------------
2950 For any other issues, feel free to use the mailing lists:
2952 http://sourceforge.net/mail/?group_id=11118.
2954 Anyone interested in actively participating in development and related
2955 discussions can also join the appropriate mailing list. Archives are available,
2956 too. See the page on Sourceforge.
2958 -------------------------------------------------------------------------------
2960 13. Copyright and History
2964 Privoxy is free software; you can redistribute it and/or modify it under the
2965 terms of the GNU General Public License as published by the Free Software
2966 Foundation; either version 2 of the License, or (at your option) any later
2969 This program is distributed in the hope that it will be useful, but WITHOUT ANY
2970 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
2971 PARTICULAR PURPOSE. See the GNU General Public License for more details, which
2972 is available from the Free Software Foundation, Inc, 59 Temple Place - Suite
2973 330, Boston, MA 02111-1307, USA.
2975 You should have received a copy of the GNU General Public License along with
2976 this program; if not, write to the Free Software Foundation, Inc., 59 Temple
2977 Place, Suite 330, Boston, MA 02111-1307 USA.
2979 -------------------------------------------------------------------------------
2983 Privoxy is evolved, and derived from, the Internet Junkbuster, with many
2984 improvments and enhancements over the original.
2986 Junkbuster was originally written by Anonymous Coders and Junkbusters
2987 Corporation, and was released as free open-source software under the GNU GPL.
2988 Stefan Waldherr made many improvements, and started the SourceForge project
2989 Privoxy to rekindle development. There are now several active developers
2990 contributing. The last stable release of Junkbuster was v2.0.2, which has now
2993 -------------------------------------------------------------------------------
2997 Other references and sites of interest to Privoxy users:
2999 http://www.privoxy.org/, The Privoxy Home page.
3001 http://sourceforge.net/projects/ijbswa, the Project Page for Privoxy on
3004 http://p.p/, access Privoxy from your browser. Alternately, http://
3005 config.privoxy.org may work in some situations where the first does not.
3007 http://p.p/, and select "Privoxy - Submit Filter Feedback" to submit "misses"
3010 http://www.junkbusters.com/ht/en/cookies.html
3012 http://www.waldherr.org/junkbuster/
3014 http://privacy.net/analyze/
3016 http://www.squid-cache.org/
3020 -------------------------------------------------------------------------------
3024 15.1. Regular Expressions
3026 Privoxy can use "regular expressions" in various config files. Assuming support
3027 for "pcre" (Perl Compatible Regular Expressions) is compiled in, which is the
3028 default. Such configuration directives do not require regular expressions, but
3029 they can be used to increase flexibility by matching a pattern with wild-cards
3032 If you are reading this, you probably don't understand what "regular
3033 expressions" are, or what they can do. So this will be a very brief
3034 introduction only. A full explanation would require a book ;-)
3036 "Regular expressions" is a way of matching one character expression against
3037 another to see if it matches or not. One of the "expressions" is a literal
3038 string of readable characters (letter, numbers, etc), and the other is a
3039 complex string of literal characters combined with wild-cards, and other
3040 special characters, called meta-characters. The "meta-characters" have special
3041 meanings and are used to build the complex pattern to be matched against. Perl
3042 Compatible Regular Expressions is an enhanced form of the regular expression
3043 language with backward compatibility.
3045 To make a simple analogy, we do something similar when we use wild-card
3046 characters when listing files with the dir command in DOS. *.* matches all
3047 filenames. The "special" character here is the asterisk which matches any and
3048 all characters. We can be more specific and use ? to match just individual
3049 characters. So "dir file?.text" would match "file1.txt", "file2.txt", etc. We
3050 are pattern matching, using a similar technique to "regular expressions"!
3052 Regular expressions do essentially the same thing, but are much, much more
3053 powerful. There are many more "special characters" and ways of building complex
3054 patterns however. Let's look at a few of the common ones, and then some
3057 . - Matches any single character, e.g. "a", "A", "4", ":", or "@".
3059 ? - The preceding character or expression is matched ZERO or ONE times. Either/
3062 + - The preceding character or expression is matched ONE or MORE times.
3064 * - The preceding character or expression is matched ZERO or MORE times.
3066 \ - The "escape" character denotes that the following character should be taken
3067 literally. This is used where one of the special characters (e.g. ".") needs to
3068 be taken literally and not as a special meta-character. Example: "example
3069 \.com", makes sure the period is recognized only as a period (and not expanded
3070 to its meta-character meaning of any single character).
3072 [] - Characters enclosed in brackets will be matched if any of the enclosed
3073 characters are encountered. For instance, "[0-9]" matches any numeric digit
3074 (zero through nine). As an example, we can combine this with "+" to match any
3075 digit one of more times: "[0-9]+".
3077 () - parentheses are used to group a sub-expression, or multiple
3080 | - The "bar" character works like an "or" conditional statement. A match is
3081 successful if the sub-expression on either side of "|" matches. As an example:
3082 "/(this|that) example/" uses grouping and the bar character and would match
3083 either "this example" or "that example", and nothing else.
3085 s/string1/string2/g - This is used to rewrite strings of text. "string1" is
3086 replaced by "string2" in this example. There must of course be a match on
3089 These are just some of the ones you are likely to use when matching URLs with
3090 Privoxy, and is a long way from a definitive list. This is enough to get us
3091 started with a few simple examples which may be more illuminating:
3093 /.*/banners/.* - A simple example that uses the common combination of "." and "
3094 *" to denote any character, zero or more times. In other words, any string at
3095 all. So we start with a literal forward slash, then our regular expression
3096 pattern (".*") another literal forward slash, the string "banners", another
3097 forward slash, and lastly another ".*". We are building a directory path here.
3098 This will match any file with the path that has a directory named "banners" in
3099 it. The ".*" matches any characters, and this could conceivably be more forward
3100 slashes, so it might expand into a much longer looking path. For example, this
3101 could match: "/eye/hate/spammers/banners/annoy_me_please.gif", or just "/
3102 banners/annoying.html", or almost an infinite number of other possible
3103 combinations, just so it has "banners" in the path somewhere.
3105 A now something a little more complex:
3107 /.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward
3108 slashes again ("/"), so we are building another expression that is a file path
3109 statement. We have another ".*", so we are matching against any conceivable
3110 sub-path, just so it matches our expression. The only true literal that must
3111 match our pattern is adv, together with the forward slashes. What comes after
3112 the "adv" string is the interesting part.
3114 Remember the "?" means the preceding expression (either a literal character or
3115 anything grouped with "(...)" in this case) can exist or not, since this means
3116 either zero or one match. So "((er)?ts?|ertis(ing|ements?))" is optional, as
3117 are the individual sub-expressions: "(er)", "(ing|ements?)", and the "s". The "
3118 |" means "or". We have two of those. For instance, "(ing|ements?)", can expand
3119 to match either "ing" OR "ements?". What is being done here, is an attempt at
3120 matching as many variations of "advertisement", and similar, as possible. So
3121 this would expand to match just "adv", or "advert", or "adverts", or
3122 "advertising", or "advertisement", or "advertisements". You get the idea. But
3123 it would not match "advertizements" (with a "z"). We could fix that by changing
3124 our regular expression to: "/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/", which
3125 would then match either spelling.
3127 /.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward
3128 slashes. Anything in the square brackets "[]" can be matched. This is using
3129 "0-9" as a shorthand expression to mean any digit one through nine. It is the
3130 same as saying "0123456789". So any digit matches. The "+" means one or more of
3131 the preceding expression must be included. The preceding expression here is
3132 what is in the square brackets -- in this case, any digit one through nine.
3133 Then, at the end, we have a grouping: "(gif|jpe?g)". This includes a "|", so
3134 this needs to match the expression on either side of that bar character also. A
3135 simple "gif" on one side, and the other side will in turn match either "jpeg"
3136 or "jpg", since the "?" means the letter "e" is optional and can be matched
3137 once or not at all. So we are building an expression here to match image GIF or
3138 JPEG type image file. It must include the literal string "advert", then one or
3139 more digits, and a "." (which is now a literal, and not a special character,
3140 since it is escaped with "\"), and lastly either "gif", or "jpeg", or "jpg".
3141 Some possible matches would include: "//advert1.jpg", "/nasty/ads/
3142 advert1234.gif", "/banners/from/hell/advert99.jpg". It would not match
3143 "advert1.gif" (no leading slash), or "/adverts232.jpg" (the expression does not
3144 include an "s"), or "/advert1.jsp" ("jsp" is not in the expression anywhere).
3146 s/microsoft(?!.com)/MicroSuck/i - This is a substitution. "MicroSuck" will
3147 replace any occurrence of "microsoft". The "i" at the end of the expression
3148 means ignore case. The "(?!.com)" means the match should fail if "microsoft" is
3149 followed by ".com". In other words, this acts like a "NOT" modifier. In case
3150 this is a hyperlink, we don't want to break it ;-).
3152 We are barely scratching the surface of regular expressions here so that you
3153 can understand the default Privoxy configuration files, and maybe use this
3154 knowledge to customize your own installation. There is much, much more that can
3155 be done with regular expressions. Now that you know enough to get started, you
3156 can learn more on your own :/
3158 More reading on Perl Compatible Regular expressions: http://www.perldoc.com/
3159 perl5.6/pod/perlre.html
3161 -------------------------------------------------------------------------------
3163 15.2. Privoxy's Internal Pages
3165 Since Privoxy proxies each requested web page, it is easy for Privoxy to trap
3166 certain special URLs. In this way, we can talk directly to Privoxy, and see how
3167 it is configured, see how our rules are being applied, change these rules and
3168 other configuration options, and even turn Privoxy's filtering off, all with a
3171 The URLs listed below are the special ones that allow direct access to Privoxy.
3172 Of course, Privoxy must be running to access these. If not, you will get a
3173 friendly error message. Internet access is not necessary either.
3175 * Privoxy main page:
3177 http://config.privoxy.org/
3179 Alternately, this may be reached at http://p.p/, but this variation may not
3180 work as reliably as the above in some configurations.
3182 * Show information about the current configuration, including viewing and
3183 editing of actions files:
3185 http://config.privoxy.org/show-status
3187 * Show the source code version numbers:
3189 http://config.privoxy.org/show-version
3191 * Show the browser's request headers:
3193 http://config.privoxy.org/show-request
3195 * Show which actions apply to a URL and why:
3197 http://config.privoxy.org/show-url-info
3199 * Toggle Privoxy on or off. In this case, "Privoxy" continues to run, but
3200 only as a pass-through proxy, with no actions taking place:
3202 http://config.privoxy.org/toggle
3204 Short cuts. Turn off, then on:
3206 http://config.privoxy.org/toggle?set=disable
3208 http://config.privoxy.org/toggle?set=enable
3210 These may be bookmarked for quick reference. See next.
3212 -------------------------------------------------------------------------------
3214 15.2.1. Bookmarklets
3216 Below are some "bookmarklets" to allow you to easily access a "mini" version of
3217 some of Privoxy's special pages. They are designed for MS Internet Explorer,
3218 but should work equally well in Netscape, Mozilla, and other browsers which
3219 support JavaScript. They are designed to run directly from your bookmarks - not
3220 by clicking the links below (although that should work for testing).
3222 To save them, right-click the link and choose "Add to Favorites" (IE) or "Add
3223 Bookmark" (Netscape). You will get a warning that the bookmark "may not be
3224 safe" - just click OK. Then you can run the Bookmarklet directly from your
3225 favorites/bookmarks. For even faster access, you can put them on the "Links"
3226 bar (IE) or the "Personal Toolbar" (Netscape), and run them with a single
3233 * Privoxy - Toggle Privoxy (Toggles between enabled and disabled)
3235 * Privoxy- View Status
3237 * Privoxy - Submit Filter Feedback
3239 Credit: The site which gave me the general idea for these bookmarklets is
3240 www.bookmarklets.com. They have more information about bookmarklets.
3242 -------------------------------------------------------------------------------
3244 15.3. Chain of Events
3246 Let's take a quick look at the basic sequence of events when a web page is
3247 requested by your browser and Privoxy is on duty:
3249 * First, your web browser requests a web page. The browser knows to send the
3250 request to Privoxy, which will in turn, relay the request to the remote web
3251 server after passing the following tests:
3253 * Privoxy traps any request for its own internal CGI pages (e.g http://p.p/)
3254 and sends the CGI page back to the browser.
3256 * Next, Privoxy checks to see if the URL matches any "+block" patterns. If
3257 so, the URL is then blocked, and the remote web server will not be
3258 contacted. "+handle-as-image" is then checked and if it does not match, an
3259 HTML "BLOCKED" page is sent back. Otherwise, if it does match, an image is
3260 returned. The type of image depends on the setting of "+set-image-blocker"
3261 (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
3263 * Untrusted URLs are blocked. If URLs are being added to the trust file, then
3266 * If the URL pattern matches the "+fast-redirects" action, it is then
3267 processed. Unwanted parts of the requested URL are stripped.
3269 * Now the rest of the client browser's request headers are processed. If any
3270 of these match any of the relevant actions (e.g. "+hide-user-agent", etc.),
3271 headers are suppressed or forged as determined by these actions and their
3274 * Now the web server starts sending its response back (i.e. typically a web
3275 page and related data).
3277 * First, the server headers are read and processed to determine, among other
3278 things, the MIME type (document type) and encoding. The headers are then
3279 filtered as deterimed by the "+prevent-setting-cookies",
3280 "+session-cookies-only", and "+downgrade-http-version" actions.
3282 * If the "+kill-popups" action applies, and it is an HTML or JavaScript
3283 document, the popup-code in the response is filtered on-the-fly as it is
3286 * If a "+filter" or "+deanimate-gifs" action applies (and the document type
3287 fits the action), the rest of the page is read into memory (up to a
3288 configurable limit). Then the filter rules (from default.filter) are
3289 processed against the buffered content. Filters are applied in the order
3290 they are specified in the default.filter file. Animated GIFs, if present,
3291 are reduced to either the first or last frame, depending on the action
3292 setting.The entire page, which is now filtered, is then sent by Privoxy
3293 back to your browser.
3295 If neither "+filter" or "+deanimate-gifs" matches, then Privoxy passes the
3296 raw data through to the client browser as it becomes available.
3298 * As the browser receives the now (probably filtered) page content, it reads
3299 and then requests any URLs that may be embedded within the page source,
3300 e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
3301 frames), sounds, etc. For each of these objects, the browser issues a new
3302 request. And each such request is in turn processed as above. Note that a
3303 complex web page may have many such embedded URLs.
3305 -------------------------------------------------------------------------------
3307 15.4. Anatomy of an Action
3309 The way Privoxy applies "actions" and "filters" to any given URL can be
3310 complex, and not always so easy to understand what is happening. And sometimes
3311 we need to be able to see just what Privoxy is doing. Especially, if something
3312 Privoxy is doing is causing us a problem inadvertently. It can be a little
3313 daunting to look at the actions and filters files themselves, since they tend
3314 to be filled with "regular expressions" whose consequences are not always so
3317 One quick test to see if Privoxy is causing a problem or not, is to disable it
3318 temporarily. This should be the first troubleshooting step. See the
3319 Bookmarklets section on a quick and easy way to do this (be sure to flush
3322 Privoxy also provides the http://config.privoxy.org/show-url-info page that can
3323 show us very specifically how actions are being applied to any given URL. This
3324 is a big help for troubleshooting.
3326 First, enter one URL (or partial URL) at the prompt, and then Privoxy will tell
3327 us how the current configuration will handle it. This will not help with
3328 filtering effects (i.e. the "+filter" action) from the default.filter file
3329 since this is handled very differently and not so easy to trap! It also will
3330 not tell you about any other URLs that may be embedded within the URL you are
3331 testing. For instance, images such as ads are expressed as URLs within the raw
3332 page source of HTML pages. So you will only get info for the actual URL that is
3333 pasted into the prompt area -- not any sub-URLs. If you want to know about
3334 embedded URLs like ads, you will have to dig those out of the HTML source. Use
3335 your browser's "View Page Source" option for this. Or right click on the ad,
3338 Let's try an example, google.com, and look at it one section at a time:
3340 Matches for http://google.com:
3342 --- File standard ---
3343 (no matches in this file)
3345 --- File default ---
3347 { -add-header -block +deanimate-gifs{last} -downgrade-http-version +fast-redirects
3348 -filter{popups} -filter{fun} -filter{shockwave-flash} -filter{crude-parental}
3349 +filter{html-annoyances} +filter{js-annoyances} +filter{content-cookies}
3350 +filter{webbugs} +filter{refresh-tags} +filter{nimda} +filter{banners-by-size}
3351 +hide-forwarded-for-headers +hide-from-header{block} +hide-referer{forge}
3352 -hide-user-agent -handle-as-image +set-image-blocker{pattern} -limit-connect
3353 +prevent-compression +session-cookies-only -prevent-reading-cookies
3354 -prevent-setting-cookies -kill-popups -send-vanilla-wafer -send-wafer }
3357 { -session-cookies-only }
3364 (no matches in this file)
3366 This tells us how we have defined our "actions", and which ones match for our
3367 example, "google.com". The first listing is any matches for the standard.action
3368 file. No hits at all here on "standard". Then next is "default", or our
3369 default.action file. The large, multi-line listing, is how the actions are set
3370 to match for all URLs, i.e. our default settings. If you look at your "actions"
3371 file, this would be the section just below the "aliases" section near the top.
3372 This will apply to all URLs as signified by the single forward slash at the end
3373 of the listing -- "/".
3375 But we can define additional actions that would be exceptions to these general
3376 rules, and then list specific URLs (or patterns) that these exceptions would
3377 apply to. Last match wins. Just below this then are two explicit matches for
3378 ".google.com". The first is negating our previous cookie setting, which was for
3379 "+session-cookies-only" (i.e. not persistent). So we will allow persistent
3380 cookies for google. The second turns off any "+fast-redirects" action, allowing
3381 this to take place unmolested. Note that there is a leading dot here --
3382 ".google.com". This will match any hosts and sub-domains, in the google.com
3383 domain also, such as "www.google.com". So, apparently, we have these two
3384 actions defined somewhere in the lower part of our default.action file, and
3385 "google.com" is referenced somewhere in these latter sections.
3387 Then, for our user.action file, we again have no hits.
3389 And finally we pull it all together in the bottom section and summarize how
3390 Privoxy is applying all its "actions" to "google.com":
3393 -add-header -block +deanimate-gifs{last} -downgrade-http-version -fast-redirects
3394 -filter{popups} -filter{fun} -filter{shockwave-flash} -filter{crude-parental}
3395 +filter{html-annoyances} +filter{js-annoyances} +filter{content-cookies}
3396 +filter{webbugs} +filter{refresh-tags} +filter{nimda} +filter{banners-by-size}
3397 +hide-forwarded-for-headers +hide-from-header{block} +hide-referer{forge}
3398 -hide-user-agent -handle-as-image +set-image-blocker{pattern} -limit-connect
3399 +prevent-compression -session-cookies-only -prevent-reading-cookies
3400 -prevent-setting-cookies -kill-popups -send-vanilla-wafer -send-wafer
3402 Notice the only difference here to the previous listing, is to "fast-redirects"
3403 and "session-cookies-only".
3405 Now another example, "ad.doubleclick.net":
3407 { +block +handle-as-image }
3410 { +block +handle-as-image }
3413 { +block +handle-as-image }
3416 We'll just show the interesting part here, the explicit matches. It is matched
3417 three different times. Each as an "+block +handle-as-image", which is the
3418 expanded form of one of our aliases that had been defined as: "+imageblock". (
3419 "Aliases" are defined in the first section of the actions file and typically
3420 used to combine more than one action.)
3422 Any one of these would have done the trick and blocked this as an unwanted
3423 image. This is unnecessarily redundant since the last case effectively would
3424 also cover the first. No point in taking chances with these guys though ;-)
3425 Note that if you want an ad or obnoxious URL to be invisible, it should be
3426 defined as "ad.doubleclick.net" is done here -- as both a "+block" and an
3427 "+handle-as-image". The custom alias "+imageblock" just simplifies the process
3428 and make it more readable.
3430 One last example. Let's try "http://www.rhapsodyk.net/adsl/HOWTO/". This one is
3431 giving us problems. We are getting a blank page. Hmmm...
3433 Matches for http://www.rhapsodyk.net/adsl/HOWTO/:
3435 { -add-header -block +deanimate-gifs -downgrade-http-version +fast-redirects
3436 +filter{html-annoyances} +filter{js-annoyances} +filter{kill-popups}
3437 +filter{webbugs} +filter{nimda} +filter{banners-by-size} +filter{hal}
3438 +filter{fun} +hide-forwarded-for-headers +hide-from-header{block}
3439 +hide-referer{forge} -hide-user-agent -handle-as-image +set-image-blocker{blank}
3440 +prevent-compression +session-cookies-only -prevent-setting-cookies
3441 -prevent-reading-cookies +kill-popups -send-vanilla-wafer -send-wafer }
3444 { +block +handle-as-image }
3447 Ooops, the "/adsl/" is matching "/ads"! But we did not want this at all! Now we
3448 see why we get the blank page. We could now add a new action below this that
3449 explicitly does not block ("{-block}") paths with "adsl". There are various
3450 ways to handle such exceptions. Example:
3455 Now the page displays ;-) Be sure to flush your browser's caches when making
3456 such changes. Or, try using Shift+Reload.
3458 But now what about a situation where we get no explicit matches like we did
3461 { +block +handle-as-image }
3464 That actually was very telling and pointed us quickly to where the problem was.
3465 If you don't get this kind of match, then it means one of the default rules in
3466 the first section is causing the problem. This would require some guesswork,
3467 and maybe a little trial and error to isolate the offending rule. One likely
3468 cause would be one of the "{+filter}" actions. Try adding the URL for the site
3469 to one of aliases that turn off "+filter":
3473 .worldpay.com # for quietpc.com
3478 "{shop}" is an "alias" that expands to "{ -filter -session-cookies-only }". Or
3479 you could do your own exception to negate filtering:
3484 This would probably be most appropriately put in user.action, for local site
3487 "{fragile}" is an alias that disables most actions. This can be used as a last
3488 resort for problem sites. Remember to flush caches! If this still does not
3489 work, you will have to go through the remaining actions one by one to find
3490 which one(s) is causing the problem.
projects / privoxy.git / blob