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, with slightly
1560 different purposes. default.action sets the default policies. standard.action
1561 is used by Privoxy and the web based editor to set pre-defined values (and
1562 normally should not be edited). Local exceptions are best done in user.action.
1563 The content of these can all be viewed and edited from http://
1564 config.privoxy.org/show-status.
1566 Anything you want can be blocked, including ads, banners, or just some
1567 obnoxious URL that you would rather not see is done here. Cookies can be
1568 accepted or rejected, or accepted only during the current browser session (i.e.
1569 not written to disk), content can be modified, JavaScripts tamed, user-tracking
1570 fooled, and much more. See below for a complete list of available actions.
1572 An actions file typically has sections. Near the top, "aliases" are optionally
1573 defined (discussed below), then the default set of rules which will apply
1574 universally to all sites and pages. And then below that, exceptions to the
1575 defined universal policies.
1577 -------------------------------------------------------------------------------
1579 9.1. Finding the Right Mix
1581 Note that some actions, like cookie suppression or script disabling, may render
1582 some sites unusable that rely on these techniques to work properly. Finding the
1583 right mix of actions is not always easy and certainly a matter of personal
1584 taste. In general, it can be said that the more "aggressive" your default
1585 settings (in the top section of the actions file) are, the more exceptions for
1586 "trusted" sites you will have to make later. If, for example, you want to kill
1587 popup windows per default, you'll have to make exceptions from that rule for
1588 sites that you regularly use and that require popups for actually useful
1589 content, like maybe your bank, favorite shop, or newspaper.
1591 We have tried to provide you with reasonable rules to start from in the
1592 distribution actions files. But there is no general rule of thumb on these
1593 things. There just are too many variables, and sites are constantly changing.
1594 Sooner or later you will want to change the rules (and read this chapter again
1597 -------------------------------------------------------------------------------
1601 The easiest way to edit the "actions" files is with a browser by using our
1602 browser-based editor, which can be reached from http://config.privoxy.org/
1605 If you prefer plain text editing to GUIs, you can of course also directly edit
1606 the the actions files.
1608 -------------------------------------------------------------------------------
1610 9.3. How Actions are Applied to URLs
1612 Actions files are divided into sections. There are special sections, like the "
1613 alias" sections which will be discussed later. For now let's concentrate on
1614 regular sections: They have a heading line (often split up to multiple lines
1615 for readability) which consist of a list of actions, separated by whitespace
1616 and enclosed in curly braces. Below that, there is a list of URL patterns, each
1619 To determine which actions apply to a request, the URL of the request is
1620 compared to all patterns in this file. Every time it matches, the list of
1621 applicable actions for the URL is incrementally updated, using the heading of
1622 the section in which the pattern is located. If multiple matches for the same
1623 URL set the same action differently, the last match wins. If not, the effects
1624 are aggregated (e.g. a URL might match both the "+handle-as-image" and "+block"
1627 You can trace this process by visiting http://config.privoxy.org/show-url-info.
1629 More detail on this is provided in the Appendix, Anatomy of an Action.
1631 -------------------------------------------------------------------------------
1635 Generally, a pattern has the form <domain>/<path>, where both the <domain> and
1636 <path> are optional. (This is why the pattern / matches all URLs).
1640 is a domain-only pattern and will match any request to www.example.com,
1641 regardless of which document on that server is requested.
1645 means exactly the same. For domain-only patterns, the trailing / may be
1648 www.example.com/index.html
1650 matches only the single document /index.html on www.example.com.
1654 matches the document /index.html, regardless of the domain, i.e. on any web
1659 matches nothing, since it would be interpreted as a domain name and there
1660 is no top-level domain called .html.
1662 -------------------------------------------------------------------------------
1664 9.4.1. The Domain Pattern
1666 The matching of the domain part offers some flexible options: if the domain
1667 starts or ends with a dot, it becomes unanchored at that end. For example:
1671 matches any domain that ENDS in .example.com
1675 matches any domain that STARTS with www.
1679 matches any domain that CONTAINS .example. (Correctly speaking: It matches
1680 any FQDN that contains example as a domain.)
1682 Additionally, there are wild-cards that you can use in the domain names
1683 themselves. They work pretty similar to shell wild-cards: "*" stands for zero
1684 or more arbitrary characters, "?" stands for any single character, you can
1685 define character classes in square brackets and all of that can be freely
1690 matches "adserver.example.com", "ads.example.com", etc but not
1695 matches all of the above, and then some.
1699 matches www.ipix.com, pictures.epix.com, a.b.c.d.e.upix.com etc.
1701 www[1-9a-ez].example.c*
1703 matches www1.example.com, www4.example.cc, wwwd.example.cy,
1704 wwwz.example.com etc., but not wwww.example.com.
1706 -------------------------------------------------------------------------------
1708 9.4.2. The Path Pattern
1710 Privoxy uses Perl compatible regular expressions (through the PCRE library) for
1713 There is an Appendix with a brief quick-start into regular expressions, and
1714 full (very technical) documentation on PCRE regex syntax is available on-line
1715 at http://www.pcre.org/man.txt. You might also find the Perl man page on
1716 regular expressions (man perlre) useful, which is available on-line at http://
1717 www.perldoc.com/perl5.6/pod/perlre.html.
1719 Note that the path pattern is automatically left-anchored at the "/", i.e. it
1720 matches as if it would start with a "^" (regular expression speak for the
1721 beginning of a line).
1723 Please also note that matching in the path is case INSENSITIVE by default, but
1724 you can switch to case sensitive at any point in the pattern by using the "(?
1725 -i)" switch: www.example.com/(?-i)PaTtErN.* will match only documents whose
1726 path starts with PaTtErN in exactly this capitalization.
1728 -------------------------------------------------------------------------------
1732 All actions are disabled by default, until they are explicitly enabled
1733 somewhere in an actions file. Actions are turned on if preceded with a "+", and
1734 turned off if preceded with a "-". So a "+action" means "do that action", e.g.
1735 "+block" means please "block the following URL patterns".
1737 Actions are invoked by enclosing the action name in curly braces (e.g.
1738 {+some_action}), followed by a list of URLs (or patterns that match URLs) to
1739 which the action applies. There are three classes of actions:
1741 * Boolean, i.e the action can only be "on" or "off". Examples:
1743 {+name} # enable this action
1744 {-name} # disable this action
1747 * Parameterized, e.g. "+/-hide-user-agent{ Mozilla 1.0 }", where some value
1748 is required in order to enable this type of action. Examples:
1750 {+name{param}} # enable action and set parameter to "param"
1751 {-name} # disable action ("parameter") can be omitted
1754 * Multi-value, e.g. "{+/-add-header{Name: value}}" or "{+/-send-wafer{name=
1755 value}}"), where some value needs to be defined in addition to simply
1756 enabling the action. Examples:
1758 {+name{param=value}} # enable action and set "param" to "value"
1759 {-name{param=value}} # remove the parameter "param" completely
1760 {-name} # disable this action totally and remove param too
1763 If nothing is specified in any actions file, no "actions" are taken. So in this
1764 case Privoxy would just be a normal, non-blocking, non-anonymizing proxy. You
1765 must specifically enable the privacy and blocking features you need (although
1766 the provided default actions files will give a good starting point).
1768 Later defined actions always over-ride earlier ones. So exceptions to any rules
1769 you make, should come in the latter part of the file (or in a file that is
1770 processed later when using multiple actions files). For multi-valued actions,
1771 the actions are applied in the order they are specified. Actions files are
1772 processed in the order they are defined in config (the default installation has
1773 three actions files). It also quite possible for any given URL pattern to match
1774 more than one action!
1776 The list of valid Privoxy "actions" are:
1778 -------------------------------------------------------------------------------
1788 Send a user defined HTTP header to the web server.
1792 Any value is possible. Validity of the defined HTTP headers is not checked.
1796 {+add-header{X-User-Tracking: sucks}}
1802 This action may be specified multiple times, in order to define multiple
1803 headers. This is rarely needed for the typical user. If you don't know what
1804 "HTTP headers" are, you definitely don't need to worry about this one.
1806 -------------------------------------------------------------------------------
1816 Used to block a URL from reaching your browser. The URL may be anything,
1817 but is typically used to block ads or other obnoxious content.
1826 .banners.example.com
1832 If a URL matches one of the blocked patterns, Privoxy will intercept the
1833 URL and display its special "BLOCKED" page instead. If there is sufficient
1834 space, a large red banner will appear with a friendly message about why the
1835 page was blocked, and a way to go there anyway. If there is insufficient
1836 space a smaller "BLOCKED" page will appear without the red banner. Click
1837 here to view the default blocked HTML page (Privoxy must be running for
1838 this to work as intended!).
1840 A very important exception is if the URL matches both "+block" and
1841 "+handle-as-image", then it will be handled by "+set-image-blocker" (see
1842 below). It is important to understand this process, in order to understand
1843 how Privoxy is able to deal with ads and other objectionable content.
1845 The "+filter" action can also perform some of the same functionality as
1846 "+block", but by virtue of very different programming techniques, and is
1847 most often used for different reasons.
1849 -------------------------------------------------------------------------------
1851 9.5.3. +deanimate-gifs
1859 To stop those annoying, distracting animated GIF images.
1867 {+deanimate-gifs{last}}
1873 De-animate all animated GIF images, i.e. reduce them to their last frame.
1874 This will also shrink the images considerably (in bytes, not pixels!). If
1875 the option "first" is given, the first frame of the animation is used as
1876 the replacement. If "last" is given, the last frame of the animation is
1877 used instead, which probably makes more sense for most banner animations,
1878 but also has the risk of not showing the entire last frame (if it is only a
1879 delta to an earlier frame).
1881 -------------------------------------------------------------------------------
1883 9.5.4. +downgrade-http-version
1891 "+downgrade-http-version" will downgrade HTTP/1.1 client requests to HTTP/
1892 1.0 and downgrade the responses as well.
1900 {+downgrade-http-version}
1906 Use this action for servers that use HTTP/1.1 protocol features that
1907 Privoxy doesn't handle well yet. HTTP/1.1 is only partially implemented.
1908 Default is not to downgrade requests. This is an infrequently needed
1909 action, and is used to help with rare problem sites only.
1911 -------------------------------------------------------------------------------
1913 9.5.5. +fast-redirects
1921 The "+fast-redirects" action enables interception of "redirect" requests
1922 from one server to another, which are used to track users.Privoxy can cut
1923 off all but the last valid URL in a redirect request and send a local
1924 redirect back to your browser without contacting the intermediate site(s).
1938 Many sites, like yahoo.com, don't just link to other sites. Instead, they
1939 will link to some script on their own server, giving the destination as a
1940 parameter, which will then redirect you to the final target. URLs resulting
1941 from this scheme typically look like: http://some.place/some_script?http://
1944 Sometimes, there are even multiple consecutive redirects encoded in the
1945 URL. These redirections via scripts make your web browsing more traceable,
1946 since the server from which you follow such a link can see where you go to.
1947 Apart from that, valuable bandwidth and time is wasted, while your browser
1948 ask the server for one redirect after the other. Plus, it feeds the
1951 This is a normally "on" feature, and often requires exceptions for sites
1952 that are sensitive to defeating this mechanism.
1954 -------------------------------------------------------------------------------
1964 Apply page filtering as defined by named sections of the default.filter
1965 file to the specified site(s). "Filtering" can be any modification of the
1966 raw page content, including re-writing or deletion of content.
1970 "+filter" must include the name of one of the section identifiers from
1971 default.filter (or whatever filterfile is specified in config).
1973 Example usage (from the current default.filter):
1975 +filter{html-annoyances}: Get rid of particularly annoying HTML abuse.
1977 +filter{js-annoyances}: Get rid of particularly annoying JavaScript abuse
1979 +filter{content-cookies}: Kill cookies that come in the HTML or JS content
1981 +filter{popups}: Kill all popups in JS and HTML
1983 +filter{frameset-borders}: Give frames a border and make them resizable
1985 +filter{webbugs}: Squish WebBugs (1x1 invisible GIFs used for user
1988 +filter{refresh-tags}: Kill automatic refresh tags (for dial-on-demand
1991 +filter{fun}: Text replacements for subversive browsing fun!
1993 +filter{nimda}: Remove Nimda (virus) code.
1995 +filter{banners-by-size}: Kill banners by size (very efficient!)
1997 +filter{shockwave-flash}: Kill embedded Shockwave Flash objects
1999 +filter{crude-parental}: Kill all web pages that contain the words "sex" or
2004 This is potentially a very powerful feature! And requires a knowledge of
2005 regular expressions if you want to "roll your own". Filtering operates on a
2006 line by line basis throughout the entire page.
2008 Filtering requires buffering the page content, which may appear to slow
2009 down page rendering since nothing is displayed until all content has passed
2010 the filters. (It does not really take longer, but seems that way since the
2011 page is not incrementally displayed.) This effect will be more noticeable
2012 on slower connections.
2014 Filtering can achieve some of the effects as the "+block" action, i.e. it
2015 can be used to block ads and banners. In the overall scheme of things,
2016 filtering is one of the first things "Privoxy" does with a web page. So
2017 other most other actions are applied to the already "filtered" page.
2019 -------------------------------------------------------------------------------
2021 9.5.7. +hide-forwarded-for-headers
2029 Block any existing X-Forwarded-for HTTP header, and do not add a new one.
2037 {+hide-forwarded-for-headers}
2043 It is fairly safe to leave this on. It does not seem to break many sites.
2045 -------------------------------------------------------------------------------
2047 9.5.8. +hide-from-header
2055 To block the browser from sending your email address in a "From:" header.
2059 Keyword: "block", or any user defined value.
2063 {+hide-from-header{block}}
2069 The keyword "block" will completely remove the header (not to be confused
2070 with the "+block" action). Alternately, you can specify any value you
2071 prefer to send to the web server.
2073 -------------------------------------------------------------------------------
2075 9.5.9. +hide-referer
2083 Don't send the "Referer:" (sic) HTTP header to the web site. Or,
2084 alternately send a forged header instead.
2088 Prevent the header from being sent with the keyword, "block". Or, "forge" a
2089 URL to one from the same server as the request. Or, set to user defined
2090 value of your choice.
2094 {+hide-referer{forge}}
2100 "forge" is the preferred option here, since some servers will not send
2101 images back otherwise.
2103 "+hide-referrer" is an alternate spelling of "+hide-referer". It has the
2104 exact same parameters, and can be freely mixed with, "+hide-referer".
2105 ("referrer" is the correct English spelling, however the HTTP specification
2106 has a bug - it requires it to be spelled as "referer".)
2108 -------------------------------------------------------------------------------
2110 9.5.10. +hide-user-agent
2118 To change the "User-Agent:" header so web servers can't tell your browser
2119 type. Who's business is it anyway?
2123 Any user defined string.
2127 {+hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}}
2133 Warning! This breaks many web sites that depend on this in order to
2134 determine how the target browser will respond to various requests. Use with
2137 -------------------------------------------------------------------------------
2139 9.5.11. +handle-as-image
2147 To define what Privoxy should treat automatically as an image, and is an
2148 important ingredient of how ads are handled.
2157 /.*\.(gif|jpg|jpeg|png|bmp|ico)
2162 This only has meaning if the URL (or pattern) also is "+block"ed, in which
2163 case a user definable image can be sent rather than a HTML page. This is
2164 integral to the whole concept of ad blocking: the URL must match both a
2165 "+block" rule, and "+handle-as-image". (See "+set-image-blocker" below for
2166 control over what will actually be displayed by the browser.)
2168 There is little reason to change the default definition for this action.
2170 -------------------------------------------------------------------------------
2172 9.5.12. +set-image-blocker
2180 Decide what to do with URLs that end up tagged with both "+block" and
2181 "+handle-as-image", e.g an advertisement.
2185 There are four available options: "-set-image-blocker" will send a HTML
2186 "blocked" page, usually resulting in a "broken image" icon.
2187 "+set-image-blocker{blank}" will send a 1x1 transparent GIF image.
2188 "+set-image-blocker{pattern}" will send a checkerboard type pattern (the
2189 default). And finally, "+set-image-blocker{http://xyz.com}" will send a
2190 HTTP temporary redirect to the specified image. This has the advantage of
2191 the icon being being cached by the browser, which will speed up the
2196 {+set-image-blocker{blank}}
2202 If you want invisible ads, they need to meet criteria as matching both
2203 images and blocked actions. And then, "image-blocker" should be set to
2204 "blank" for invisibility. Note you cannot treat HTML pages as images in
2205 most cases. For instance, frames require an HTML page to display. So a
2206 frame that is an ad, typically cannot be treated as an image. Forcing an
2207 "image" in this situation just will not work reliably.
2209 -------------------------------------------------------------------------------
2211 9.5.13. +limit-connect
2219 By default, Privoxy only allows HTTP CONNECT requests to port 443 (the
2220 standard, secure HTTPS port). Use "+limit-connect" to disable this
2221 altogether, or to allow more ports.
2225 Any valid port number, or port number range.
2229 +limit-connect{443} #
2230 This is the default and need not be specified.
2231 +limit-connect{80,443} # Ports 80 and 443 are OK.
2232 +limit-connect{-3, 7, 20-100, 500-} #
2233 Port less than 3, 7, 20 to 100 and above 500 are OK.
2238 The CONNECT methods exists in HTTP to allow access to secure websites
2239 (https:// URLs) through proxies. It works very simply: the proxy connects
2240 to the server on the specified port, and then short-circuits its
2241 connections to the client and to the remote proxy. This can be a big
2242 security hole, since CONNECT-enabled proxies can be abused as TCP relays
2245 If you want to allow CONNECT for more ports than this, or want to forbid
2246 CONNECT altogether, you can specify a comma separated list of ports and
2247 port ranges (the latter using dashes, with the minimum defaulting to 0 and
2250 If you don't know what any of this means, there probably is no reason to
2253 -------------------------------------------------------------------------------
2255 9.5.14. +prevent-compression
2263 Prevent the specified websites from compressing HTTP data.
2271 {+prevent-compression}
2277 Some websites do this, which can be a problem for Privoxy, since "+filter",
2278 "+kill-popups" and "+gif-deanimate" will not work on compressed data. This
2279 will slow down connections to those websites, though. Default typically is
2280 to turn "prevent-compression" on.
2282 -------------------------------------------------------------------------------
2284 9.5.15. +session-cookies-only
2292 Allow cookies for the current browser session only.
2298 Example usage (disabling):
2300 {-session-cookies-only}
2306 If websites set cookies, "+session-cookies-only" will make sure they are
2307 erased when you exit and restart your web browser. This makes profiling
2308 cookies useless, but won't break sites which require cookies so that you
2309 can log in for transactions. This is generally turned on for all sites, and
2310 is the recommended setting.
2312 "+prevent-*-cookies" actions should be turned off as well (see below), for
2313 "+session-cookies-only" to work. Or, else no cookies will get through at
2314 all. For, "persistent" cookies that survive across browser sessions, see
2317 -------------------------------------------------------------------------------
2319 9.5.16. +prevent-reading-cookies
2327 Explicitly prevent the web server from reading any cookies on your system.
2335 {+prevent-reading-cookies}
2341 Often used in conjunction with "+prevent-setting-cookies" to disable
2342 cookies completely. Note that "+session-cookies-only" requires these to
2343 both be disabled (or else it never gets any cookies to cache).
2345 For "persistent" cookies to work (i.e. they survive across browser sessions
2346 and reboots), all three cookie settings should be "off" for the specified
2349 -------------------------------------------------------------------------------
2351 9.5.17. +prevent-setting-cookies
2359 Explicitly block the web server from storing cookies on your system.
2367 {+prevent-setting-cookies}
2373 Often used in conjunction with "+prevent-reading-cookies" to disable
2374 cookies completely (see above).
2376 -------------------------------------------------------------------------------
2378 9.5.18. +kill-popups
2386 Stop those annoying JavaScript pop-up windows!
2400 "+kill-popups" uses a built in filter to disable pop-ups that use the
2401 window.open() function, etc. This is one of the first actions processed by
2402 Privoxy as it contacts the remote web server. This action is not always
2403 100% reliable, and is supplemented by "+filter{popups}".
2405 -------------------------------------------------------------------------------
2407 9.5.19. +send-vanilla-wafer
2415 Sends a cookie for every site stating that you do not accept any copyright
2416 on cookies sent to you, and asking them not to track you.
2424 {+send-vanilla-wafer}
2430 This action only applies if you are using a jarfile for saving cookies. Of
2431 course, this is a (relatively) unique header and could conceivably be used
2434 -------------------------------------------------------------------------------
2444 This allows you to send an arbitrary, user definable cookie.
2448 User specified cookie name and corresponding value.
2452 {+send-wafer{name=value}}
2458 This can be specified multiple times in order to add as many cookies as you
2461 -------------------------------------------------------------------------------
2465 Note that many of these actions have the potential to cause a page to
2466 misbehave, possibly even not to display at all. There are many ways a site
2467 designer may choose to design his site, and what HTTP header content, and other
2468 criteria, he may depend on. There is no way to have hard and fast rules for all
2469 sites. See the Appendix for a brief example on troubleshooting actions.
2471 -------------------------------------------------------------------------------
2473 9.5.22. Sample Actions Files
2475 Remember that the meaning of any of the above references is reversed by
2476 preceding the action with a "-", in place of the "+". Also, that some actions
2477 are turned on in the default section of the actions file, and require little to
2478 no additional configuration. These are just "on".
2480 But, other actions that are turned on in the default section do typically
2481 require exceptions to be listed in the latter sections of one of our actions
2482 file. For instance, by default no URLs are "blocked" (i.e. in the default
2483 definitions of default.action). We need exceptions to this in order to enable
2484 ad blocking in the lower sections. But we need to be very selective about what
2485 we do block. Thus, the default is "off" for blocking.
2487 Below is a liberally commented sample default.action file to demonstrate how
2488 all the pieces come together. And to show how exceptions to the default
2489 policies can be handled. This is followed by a brief user.action with similar
2492 # Sample default.action file <developers@privoxy.org>
2494 # Settings -- Don't change! For internal Privoxy use ONLY.
2496 for-privoxy-version=3.0
2499 ##########################################################################
2500 # Aliases must be defined *before* they are used. These are
2501 # easier to remember, and can combine several actions into one. Once
2502 # defined they can be used just like any built-in action -- but within
2503 # this file only! Aliases do not require a + or - sign.
2504 ##########################################################################
2506 # Some useful aliases.
2507 # Alias to turn off cookie handling, ie allow all cookies unmolested.
2508 -prevent-cookies = -prevent-setting-cookies -prevent-reading-cookies \
2509 -session-cookies-only
2511 # Alias to both block and treat as if an image for ad blocking
2513 +imageblock = +block +handle-as-image
2515 # Fragile sites should have the minimum changes:
2516 fragile = -block -deanimate-gifs -fast-redirects -filter -hide-referer \
2517 -prevent-cookies -kill-popups
2519 # Shops should be allowed to set persistent cookies
2520 shop = -filter -prevent-cookies -session-cookies-only
2523 ##########################################################################
2524 # Begin default action settings. Anything in this section will match
2525 # all URLs -- UNLESS we have exceptions that also match, defined below this
2526 # section. We will show all potential actions here whether they are on
2527 # or off. We could omit any disabled action if we wanted, since all
2528 # actions are 'off' by default anyway. Shown for completeness only.
2529 # Actions are enabled if preceded by a '+', otherwise they are disabled
2530 # (unless an alias has been defined without this).
2531 ##########################################################################
2536 -downgrade-http-version \
2538 +filter{html-annoyances} \
2539 +filter{js-annoyances} \
2540 -filter{content-cookies} \
2543 -filter{refresh-tags} \
2546 +filter{banners-by-size} \
2547 -filter{shockwave-flash} \
2548 -filter{crude-prental} \
2549 +hide-forwarded-for-headers \
2550 +hide-from-header{block} \
2554 +set-image-blocker{pattern} \
2556 +prevent-compression \
2557 -session-cookies-only \
2558 -prevent-reading-cookies \
2559 -prevent-setting-cookies \
2561 -send-vanilla-wafer \
2564 / # forward slash will match *all* potential URL patterns.
2566 ##########################################################################
2567 # Default behavior is now set. Now we will define some exceptions to our
2568 # default action policies.
2569 ##########################################################################
2571 # These sites are very complex and require very minimal interference.
2572 # We'll disable most actions with our 'fragile' alias:
2574 .office.microsoft.com # surprise, surprise!
2575 .windowsupdate.microsoft.com
2578 # Shopping sites - not as fragile but require some special
2579 # handling. We still want to block ads, and we will allow
2580 # persistant cookies via the 'shop' alias:
2583 .worldpay.com # for quietpc.com
2588 # These sites require pop-ups too :( We'll combine our 'shop'
2589 # alias with two other actions into one rule to allow all popups.
2590 { shop -kill-popups -filter{popups} }
2595 # The 'Fast-redirects' action breaks some sites. Disable this action
2596 # for these known sensitive sites:
2599 edit.europe.yahoo.com
2601 .altavista.com/.*(like|url|link):http
2602 .altavista.com/trans.*urltext=http
2606 # Define which file types will be treated as images. Important
2608 { +handle-as-image }
2609 /.*\.(gif|jpe?g|png|bmp|ico)
2612 # Now lets list some domains that are known ad generators. And
2613 # our alias that we use here will block these as well as force
2614 # them to be treated as images. This combination of actions is
2615 # important for ad blocking. What the browser will show instead is
2616 # determined by the setting of "+set-image-blocker"
2620 .a.yimg.com/(?:(?!/i/).)*$
2621 .a[0-9].yimg.com/(?:(?!/i/).)*$
2625 ad.*.doubleclick.net
2628 # These will just simply be blocked. They will generate the BLOCKED
2629 # banner page, if matched. Heavy use of wildcards and regular
2630 # expressions in this example. Enable block action:
2636 /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
2637 /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
2641 # The above block section will probably inadvertantly catch some
2642 # sites we DO NOT want blocked via the wildcards and regular expressions.
2643 # Now let's set exceptions to the exceptions so the good guys get better
2644 # treatment. Disable block action:
2650 # Let's just trust all .edu top level domains.
2652 www.ugu.com/sui/ugu/adv
2653 # We'll need to access to path names containing 'download'
2656 # 'adv' is for globalintersec and means advanced, not advertisement
2657 www.globalintersec.com/adv
2660 # Don't filter *anything* from our friends at sourceforge.
2661 # Notice we don't have to name the individual filter
2662 # identifiers -- we just turn them all off in one fell swoop.
2663 # Disable all filters for this one site:
2668 So far we are painting with a broad brush by setting general policies. The
2669 above would be a reasonable starting point for many situations. Now, we want to
2670 be more specific and have customized rules that are more suitable to our
2671 personal habits and preferences. These would be for narrowly defined situations
2672 like your ISP or your bank, and should be placed in user.action, which is
2673 parsed after all other actions files and should not be clobbered by upgrades.
2674 So any settings here, will have the last word and over-ride any previously
2677 Now a few examples of some things that one might do with a user.action file.
2679 # Sample user.action file.
2681 # Any aliases you want to use need to be re-defined here.
2682 # Alias to turn off cookie handling, ie allow all cookies unmolested.
2683 -prevent-cookies = -prevent-setting-cookies -prevent-reading-cookies \
2684 -session-cookies-only
2686 # Fragile sites should have the minimum changes:
2687 fragile = -block -deanimate-gifs -fast-redirects -filter -hide-referer \
2688 -prevent-cookies -kill-popups
2690 # Allow persistent cookies for a few regular sites that we
2691 # trust via our above alias. These will be saved from one browser session
2692 # to the next. We are explicity turning off any and all cookie handling,
2693 # even though the prevent-*-cookie settings were disabled in our above
2694 # default.action anyway. So cookies from these domains will come through
2696 { -prevent-cookies }
2703 # My ISP uses obnoxious self promoting images on many pages.
2704 # Nuke them :) Note that "+handle-as-image" need not be specified,
2705 # since all URLs ending in .gif will be tagged as images by the
2706 # general rules in default.action anyway.
2708 www.my-isp-example.com/logo[0-9].gif
2710 # Say the site where you do your homebanking needs to open
2711 # popup windows, but you have chosen to kill popups by
2712 # default. This will allow it for your-example-bank.com:
2714 { -filter{popups} -kill-popups }
2715 .my-example-bank.com
2717 # This site is delicate, and requires kid-glove
2723 -------------------------------------------------------------------------------
2727 Custom "actions", known to Privoxy as "aliases", can be defined by combining
2728 other "actions". These can in turn be invoked just like the built-in "actions".
2729 Currently, an alias can contain any character except space, tab, "=", "{" or "}
2730 ". But please use only "a"- "z", "0"-"9", "+", and "-". Alias names are not
2731 case sensitive, and must be defined before other actions in the actions file!
2732 And there can only be one set of "aliases" defined per file. Each actions file
2733 may have its own aliases, but they are only visible within that file. Aliases
2734 do not requir a "+" or "-" sign in front, since they are merely expanded.
2736 Now let's define a few aliases:
2738 # Useful custom aliases we can use later. These must come first!
2740 +prevent-cookies = +prevent-setting-cookies +prevent-reading-cookies
2741 -prevent-cookies = -prevent-setting-cookies -prevent-reading-cookies
2743 -block -prevent-cookies -filter -fast-redirects -hide-referer -kill-popups
2744 shop = -prevent-cookies -filter -fast-redirects
2745 +imageblock = +block +handle-as-image
2747 # Aliases defined from other aliases, for people who don't like to type
2749 c0 = +prevent-cookies
2750 c1 = -prevent-cookies
2751 #... etc. Customize to your heart's content.
2754 Some examples using our "shop" and "fragile" aliases from above. These would
2755 appear in the lower sections of an actions file as exceptions to the default
2756 actions (as defined in the upper section):
2758 # These sites are very complex and require
2759 # minimal interference.
2761 .office.microsoft.com
2762 .windowsupdate.microsoft.com
2765 # Shopping sites - but we still want to block ads.
2768 .worldpay.com # for quietpc.com
2771 # These shops require pop-ups also
2777 The "shop" and "fragile" aliases are often used for "problem" sites that
2778 require most actions to be disabled in order to function properly.
2780 -------------------------------------------------------------------------------
2784 Any web page can be dynamically modified with the filter file. This
2785 modification can be removal, or re-writing, of any web page content, including
2786 tags and non-visible content. The default filter file is oddly enough
2787 default.filter, located in the config directory.
2789 This is potentially a very powerful feature, and requires knowledge of both
2790 "regular expression" and HTML in order create custom filters. But, there are a
2791 number of useful filters included with Privoxy for many common situations.
2793 The included example file is divided into sections. Each section begins with
2794 the FILTER keyword, followed by the identifier for that section, e.g. "FILTER:
2795 webbugs". Each section performs a similar type of filtering, such as
2798 This file uses regular expressions to alter or remove any string in the target
2799 page. The expressions can only operate on one line at a time. Some examples
2800 from the included default default.filter:
2802 Stop web pages from displaying annoying messages in the status bar by deleting
2805 FILTER: html-annoyances
2807 # New browser windows should be resizeable and have a location and status
2810 s/resizable="?(no|0)"?/resizable=1/ig s/noresize/yesresize/ig
2811 s/location="?(no|0)"?/location=1/ig s/status="?(no|0)"?/status=1/ig
2812 s/scrolling="?(no|0|Auto)"?/scrolling=1/ig
2813 s/menubar="?(no|0)"?/menubar=1/ig
2815 # The <BLINK> tag was a crime!
2817 s*<blink>|</blink>**ig
2821 #s/framespacing="?(no|0)"?//ig
2822 #s/margin(height|width)=[0-9]*//gi
2825 Just for kicks, replace any occurrence of "Microsoft" with "MicroSuck", and
2826 have a little fun with topical buzzwords:
2830 s/microsoft(?!.com)/MicroSuck/ig
2834 s/industry-leading|cutting-edge|award-winning/<font color=red><b>BINGO!</b></
2838 Kill those pesky little web-bugs:
2840 # webbugs: Squish WebBugs (1x1 invisible GIFs used for user tracking)
2843 s/<img\s+[^>]*?(width|height)\s*=\s*['"]?1\D[^>]*?(width|height)\s*=\s*['"]?1
2844 (\D[^>]*?)?>/<!-- Squished WebBug -->/sig
2847 -------------------------------------------------------------------------------
2849 10.1. The +filter Action
2851 Filters are enabled with the "+filter" action from within one of the actions
2852 files. "+filter" requires one parameter, which should match one of the section
2853 identifiers in the filter file itself. Example:
2855 +filter{html-annoyances}
2857 This would activate that particular filter. Similarly, "+filter" can be turned
2858 off for selected sites as: "-filter{html-annoyances}". Remember too, all
2859 actions are off by default, unless they are explicity enabled in one of the
2862 -------------------------------------------------------------------------------
2866 When Privoxy displays one of its internal pages, such as a 404 Not Found error
2867 page (Privoxy must be running for link to work as intended), it uses the
2868 appropriate template. On Linux, BSD, and Unix, these are located in /etc/
2869 privoxy/templates by default. These may be customized, if desired.
2870 cgi-style.css is used to control the HTML attributes (fonts, etc).
2872 The default Blocked (Privoxy needs to be running for page to display) banner
2873 page with the bright red top banner, is called just "blocked". This may be
2874 customized or replaced with something else if desired.
2876 -------------------------------------------------------------------------------
2878 12. Contacting the Developers, Bug Reporting and Feature Requests
2880 We value your feedback. However, to provide you with the best support, please
2881 note the following sections.
2883 -------------------------------------------------------------------------------
2887 To get support, use the Sourceforge Support Forum:
2889 http://sourceforge.net/tracker/?group_id=11118&atid=211118
2891 -------------------------------------------------------------------------------
2895 To submit bugs, use the Sourceforge Bug Forum:
2897 http://sourceforge.net/tracker/?group_id=11118&atid=111118.
2899 Make sure that the bug has not already been submitted. Please try to verify
2900 that it is a Privoxy bug, and not a browser or site bug first. If you are using
2901 your own custom configuration, please try the stock configs to see if the
2902 problem is a configuration related bug. And if not using the latest development
2903 snapshot, please try the latest one. Or even better, CVS sources. Please be
2904 sure to include the Privoxy version, platform, browser, any pertinent log data,
2905 any other relevant details (please be specific) and, if possible, some way to
2908 -------------------------------------------------------------------------------
2910 12.3. Request new features
2912 To submit ideas on new features, use the Sourceforge feature request forum:
2914 http://sourceforge.net/tracker/?atid=361118&group_id=11118&func=browse.
2916 -------------------------------------------------------------------------------
2918 12.4. Report ads or other filter problems
2920 You can also send feedback on websites that Privoxy has problems with. Please
2921 bookmark the following link: "Privoxy - Submit Filter Feedback". Once you surf
2922 to a page with problems, use the bookmark to send us feedback. We will look
2923 into the issue as soon as possible.
2925 New, improved default.action files will occasionally be made available based on
2926 your feedback. These will be announced on the ijbswa-announce list.
2928 -------------------------------------------------------------------------------
2932 For any other issues, feel free to use the mailing lists:
2934 http://sourceforge.net/mail/?group_id=11118.
2936 Anyone interested in actively participating in development and related
2937 discussions can also join the appropriate mailing list. Archives are available,
2938 too. See the page on Sourceforge.
2940 -------------------------------------------------------------------------------
2942 13. Copyright and History
2946 Privoxy is free software; you can redistribute it and/or modify it under the
2947 terms of the GNU General Public License as published by the Free Software
2948 Foundation; either version 2 of the License, or (at your option) any later
2951 This program is distributed in the hope that it will be useful, but WITHOUT ANY
2952 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
2953 PARTICULAR PURPOSE. See the GNU General Public License for more details, which
2954 is available from the Free Software Foundation, Inc, 59 Temple Place - Suite
2955 330, Boston, MA 02111-1307, USA.
2957 You should have received a copy of the GNU General Public License along with
2958 this program; if not, write to the Free Software Foundation, Inc., 59 Temple
2959 Place, Suite 330, Boston, MA 02111-1307 USA.
2961 -------------------------------------------------------------------------------
2965 Privoxy is evolved, and derived from, the Internet Junkbuster, with many
2966 improvments and enhancements over the original.
2968 Junkbuster was originally written by Anonymous Coders and Junkbusters
2969 Corporation, and was released as free open-source software under the GNU GPL.
2970 Stefan Waldherr made many improvements, and started the SourceForge project
2971 Privoxy to rekindle development. There are now several active developers
2972 contributing. The last stable release of Junkbuster was v2.0.2, which has now
2975 -------------------------------------------------------------------------------
2979 Other references and sites of interest to Privoxy users:
2981 http://www.privoxy.org/, The Privoxy Home page.
2983 http://sourceforge.net/projects/ijbswa, the Project Page for Privoxy on
2986 http://p.p/, access Privoxy from your browser. Alternately, http://
2987 config.privoxy.org may work in some situations where the first does not.
2989 http://p.p/, and select "Privoxy - Submit Filter Feedback" to submit "misses"
2992 http://www.junkbusters.com/ht/en/cookies.html
2994 http://www.waldherr.org/junkbuster/
2996 http://privacy.net/analyze/
2998 http://www.squid-cache.org/
3002 -------------------------------------------------------------------------------
3006 15.1. Regular Expressions
3008 Privoxy can use "regular expressions" in various config files. Assuming support
3009 for "pcre" (Perl Compatible Regular Expressions) is compiled in, which is the
3010 default. Such configuration directives do not require regular expressions, but
3011 they can be used to increase flexibility by matching a pattern with wild-cards
3014 If you are reading this, you probably don't understand what "regular
3015 expressions" are, or what they can do. So this will be a very brief
3016 introduction only. A full explanation would require a book ;-)
3018 "Regular expressions" is a way of matching one character expression against
3019 another to see if it matches or not. One of the "expressions" is a literal
3020 string of readable characters (letter, numbers, etc), and the other is a
3021 complex string of literal characters combined with wild-cards, and other
3022 special characters, called meta-characters. The "meta-characters" have special
3023 meanings and are used to build the complex pattern to be matched against. Perl
3024 Compatible Regular Expressions is an enhanced form of the regular expression
3025 language with backward compatibility.
3027 To make a simple analogy, we do something similar when we use wild-card
3028 characters when listing files with the dir command in DOS. *.* matches all
3029 filenames. The "special" character here is the asterisk which matches any and
3030 all characters. We can be more specific and use ? to match just individual
3031 characters. So "dir file?.text" would match "file1.txt", "file2.txt", etc. We
3032 are pattern matching, using a similar technique to "regular expressions"!
3034 Regular expressions do essentially the same thing, but are much, much more
3035 powerful. There are many more "special characters" and ways of building complex
3036 patterns however. Let's look at a few of the common ones, and then some
3039 . - Matches any single character, e.g. "a", "A", "4", ":", or "@".
3041 ? - The preceding character or expression is matched ZERO or ONE times. Either/
3044 + - The preceding character or expression is matched ONE or MORE times.
3046 * - The preceding character or expression is matched ZERO or MORE times.
3048 \ - The "escape" character denotes that the following character should be taken
3049 literally. This is used where one of the special characters (e.g. ".") needs to
3050 be taken literally and not as a special meta-character. Example: "example
3051 \.com", makes sure the period is recognized only as a period (and not expanded
3052 to its meta-character meaning of any single character).
3054 [] - Characters enclosed in brackets will be matched if any of the enclosed
3055 characters are encountered. For instance, "[0-9]" matches any numeric digit
3056 (zero through nine). As an example, we can combine this with "+" to match any
3057 digit one of more times: "[0-9]+".
3059 () - parentheses are used to group a sub-expression, or multiple
3062 | - The "bar" character works like an "or" conditional statement. A match is
3063 successful if the sub-expression on either side of "|" matches. As an example:
3064 "/(this|that) example/" uses grouping and the bar character and would match
3065 either "this example" or "that example", and nothing else.
3067 s/string1/string2/g - This is used to rewrite strings of text. "string1" is
3068 replaced by "string2" in this example. There must of course be a match on
3071 These are just some of the ones you are likely to use when matching URLs with
3072 Privoxy, and is a long way from a definitive list. This is enough to get us
3073 started with a few simple examples which may be more illuminating:
3075 /.*/banners/.* - A simple example that uses the common combination of "." and "
3076 *" to denote any character, zero or more times. In other words, any string at
3077 all. So we start with a literal forward slash, then our regular expression
3078 pattern (".*") another literal forward slash, the string "banners", another
3079 forward slash, and lastly another ".*". We are building a directory path here.
3080 This will match any file with the path that has a directory named "banners" in
3081 it. The ".*" matches any characters, and this could conceivably be more forward
3082 slashes, so it might expand into a much longer looking path. For example, this
3083 could match: "/eye/hate/spammers/banners/annoy_me_please.gif", or just "/
3084 banners/annoying.html", or almost an infinite number of other possible
3085 combinations, just so it has "banners" in the path somewhere.
3087 A now something a little more complex:
3089 /.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward
3090 slashes again ("/"), so we are building another expression that is a file path
3091 statement. We have another ".*", so we are matching against any conceivable
3092 sub-path, just so it matches our expression. The only true literal that must
3093 match our pattern is adv, together with the forward slashes. What comes after
3094 the "adv" string is the interesting part.
3096 Remember the "?" means the preceding expression (either a literal character or
3097 anything grouped with "(...)" in this case) can exist or not, since this means
3098 either zero or one match. So "((er)?ts?|ertis(ing|ements?))" is optional, as
3099 are the individual sub-expressions: "(er)", "(ing|ements?)", and the "s". The "
3100 |" means "or". We have two of those. For instance, "(ing|ements?)", can expand
3101 to match either "ing" OR "ements?". What is being done here, is an attempt at
3102 matching as many variations of "advertisement", and similar, as possible. So
3103 this would expand to match just "adv", or "advert", or "adverts", or
3104 "advertising", or "advertisement", or "advertisements". You get the idea. But
3105 it would not match "advertizements" (with a "z"). We could fix that by changing
3106 our regular expression to: "/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/", which
3107 would then match either spelling.
3109 /.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward
3110 slashes. Anything in the square brackets "[]" can be matched. This is using
3111 "0-9" as a shorthand expression to mean any digit one through nine. It is the
3112 same as saying "0123456789". So any digit matches. The "+" means one or more of
3113 the preceding expression must be included. The preceding expression here is
3114 what is in the square brackets -- in this case, any digit one through nine.
3115 Then, at the end, we have a grouping: "(gif|jpe?g)". This includes a "|", so
3116 this needs to match the expression on either side of that bar character also. A
3117 simple "gif" on one side, and the other side will in turn match either "jpeg"
3118 or "jpg", since the "?" means the letter "e" is optional and can be matched
3119 once or not at all. So we are building an expression here to match image GIF or
3120 JPEG type image file. It must include the literal string "advert", then one or
3121 more digits, and a "." (which is now a literal, and not a special character,
3122 since it is escaped with "\"), and lastly either "gif", or "jpeg", or "jpg".
3123 Some possible matches would include: "//advert1.jpg", "/nasty/ads/
3124 advert1234.gif", "/banners/from/hell/advert99.jpg". It would not match
3125 "advert1.gif" (no leading slash), or "/adverts232.jpg" (the expression does not
3126 include an "s"), or "/advert1.jsp" ("jsp" is not in the expression anywhere).
3128 s/microsoft(?!.com)/MicroSuck/i - This is a substitution. "MicroSuck" will
3129 replace any occurrence of "microsoft". The "i" at the end of the expression
3130 means ignore case. The "(?!.com)" means the match should fail if "microsoft" is
3131 followed by ".com". In other words, this acts like a "NOT" modifier. In case
3132 this is a hyperlink, we don't want to break it ;-).
3134 We are barely scratching the surface of regular expressions here so that you
3135 can understand the default Privoxy configuration files, and maybe use this
3136 knowledge to customize your own installation. There is much, much more that can
3137 be done with regular expressions. Now that you know enough to get started, you
3138 can learn more on your own :/
3140 More reading on Perl Compatible Regular expressions: http://www.perldoc.com/
3141 perl5.6/pod/perlre.html
3143 -------------------------------------------------------------------------------
3145 15.2. Privoxy's Internal Pages
3147 Since Privoxy proxies each requested web page, it is easy for Privoxy to trap
3148 certain special URLs. In this way, we can talk directly to Privoxy, and see how
3149 it is configured, see how our rules are being applied, change these rules and
3150 other configuration options, and even turn Privoxy's filtering off, all with a
3153 The URLs listed below are the special ones that allow direct access to Privoxy.
3154 Of course, Privoxy must be running to access these. If not, you will get a
3155 friendly error message. Internet access is not necessary either.
3157 * Privoxy main page:
3159 http://config.privoxy.org/
3161 Alternately, this may be reached at http://p.p/, but this variation may not
3162 work as reliably as the above in some configurations.
3164 * Show information about the current configuration, including viewing and
3165 editing of actions files:
3167 http://config.privoxy.org/show-status
3169 * Show the source code version numbers:
3171 http://config.privoxy.org/show-version
3173 * Show the browser's request headers:
3175 http://config.privoxy.org/show-request
3177 * Show which actions apply to a URL and why:
3179 http://config.privoxy.org/show-url-info
3181 * Toggle Privoxy on or off. In this case, "Privoxy" continues to run, but
3182 only as a pass-through proxy, with no actions taking place:
3184 http://config.privoxy.org/toggle
3186 Short cuts. Turn off, then on:
3188 http://config.privoxy.org/toggle?set=disable
3190 http://config.privoxy.org/toggle?set=enable
3192 These may be bookmarked for quick reference. See next.
3194 -------------------------------------------------------------------------------
3196 15.2.1. Bookmarklets
3198 Below are some "bookmarklets" to allow you to easily access a "mini" version of
3199 some of Privoxy's special pages. They are designed for MS Internet Explorer,
3200 but should work equally well in Netscape, Mozilla, and other browsers which
3201 support JavaScript. They are designed to run directly from your bookmarks - not
3202 by clicking the links below (although that should work for testing).
3204 To save them, right-click the link and choose "Add to Favorites" (IE) or "Add
3205 Bookmark" (Netscape). You will get a warning that the bookmark "may not be
3206 safe" - just click OK. Then you can run the Bookmarklet directly from your
3207 favorites/bookmarks. For even faster access, you can put them on the "Links"
3208 bar (IE) or the "Personal Toolbar" (Netscape), and run them with a single
3215 * Privoxy - Toggle Privoxy (Toggles between enabled and disabled)
3217 * Privoxy- View Status
3219 * Privoxy - Submit Filter Feedback
3221 Credit: The site which gave me the general idea for these bookmarklets is
3222 www.bookmarklets.com. They have more information about bookmarklets.
3224 -------------------------------------------------------------------------------
3226 15.3. Chain of Events
3228 Let's take a quick look at the basic sequence of events when a web page is
3229 requested by your browser and Privoxy is on duty:
3231 * First, your web browser requests a web page. The browser knows to send the
3232 request to Privoxy, which will in turn, relay the request to the remote web
3233 server after passing the following tests:
3235 * Privoxy traps any request for its own internal CGI pages (e.g http://p.p/)
3236 and sends the CGI page back to the browser.
3238 * Next, Privoxy checks to see if the URL matches any "+block" patterns. If
3239 so, the URL is then blocked, and the remote web server will not be
3240 contacted. "+handle-as-image" is then checked and if it does not match, an
3241 HTML "BLOCKED" page is sent back. Otherwise, if it does match, an image is
3242 returned. The type of image depends on the setting of "+set-image-blocker"
3243 (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
3245 * Untrusted URLs are blocked. If URLs are being added to the trust file, then
3248 * If the URL pattern matches the "+fast-redirects" action, it is then
3249 processed. Unwanted parts of the requested URL are stripped.
3251 * Now the rest of the client browser's request headers are processed. If any
3252 of these match any of the relevant actions (e.g. "+hide-user-agent", etc.),
3253 headers are suppressed or forged as determined by these actions and their
3256 * Now the web server starts sending its response back (i.e. typically a web
3257 page and related data).
3259 * First, the server headers are read and processed to determine, among other
3260 things, the MIME type (document type) and encoding. The headers are then
3261 filtered as deterimed by the "+prevent-setting-cookies",
3262 "+session-cookies-only", and "+downgrade-http-version" actions.
3264 * If the "+kill-popups" action applies, and it is an HTML or JavaScript
3265 document, the popup-code in the response is filtered on-the-fly as it is
3268 * If a "+filter" or "+deanimate-gifs" action applies (and the document type
3269 fits the action), the rest of the page is read into memory (up to a
3270 configurable limit). Then the filter rules (from default.filter) are
3271 processed against the buffered content. Filters are applied in the order
3272 they are specified in the default.filter file. Animated GIFs, if present,
3273 are reduced to either the first or last frame, depending on the action
3274 setting.The entire page, which is now filtered, is then sent by Privoxy
3275 back to your browser.
3277 If neither "+filter" or "+deanimate-gifs" matches, then Privoxy passes the
3278 raw data through to the client browser as it becomes available.
3280 * As the browser receives the now (probably filtered) page content, it reads
3281 and then requests any URLs that may be embedded within the page source,
3282 e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
3283 frames), sounds, etc. For each of these objects, the browser issues a new
3284 request. And each such request is in turn processed as above. Note that a
3285 complex web page may have many such embedded URLs.
3287 -------------------------------------------------------------------------------
3289 15.4. Anatomy of an Action
3291 The way Privoxy applies "actions" and "filters" to any given URL can be
3292 complex, and not always so easy to understand what is happening. And sometimes
3293 we need to be able to see just what Privoxy is doing. Especially, if something
3294 Privoxy is doing is causing us a problem inadvertently. It can be a little
3295 daunting to look at the actions and filters files themselves, since they tend
3296 to be filled with "regular expressions" whose consequences are not always so
3299 One quick test to see if Privoxy is causing a problem or not, is to disable it
3300 temporarily. This should be the first troubleshooting step. See the
3301 Bookmarklets section on a quick and easy way to do this (be sure to flush
3304 Privoxy also provides the http://config.privoxy.org/show-url-info page that can
3305 show us very specifically how actions are being applied to any given URL. This
3306 is a big help for troubleshooting.
3308 First, enter one URL (or partial URL) at the prompt, and then Privoxy will tell
3309 us how the current configuration will handle it. This will not help with
3310 filtering effects (i.e. the "+filter" action) from the default.filter file
3311 since this is handled very differently and not so easy to trap! It also will
3312 not tell you about any other URLs that may be embedded within the URL you are
3313 testing. For instance, images such as ads are expressed as URLs within the raw
3314 page source of HTML pages. So you will only get info for the actual URL that is
3315 pasted into the prompt area -- not any sub-URLs. If you want to know about
3316 embedded URLs like ads, you will have to dig those out of the HTML source. Use
3317 your browser's "View Page Source" option for this. Or right click on the ad,
3320 Let's try an example, google.com, and look at it one section at a time:
3322 Matches for http://google.com:
3324 --- File standard ---
3325 (no matches in this file)
3327 --- File default ---
3329 { -add-header -block +deanimate-gifs{last} -downgrade-http-version +fast-redirects
3330 -filter{popups} -filter{fun} -filter{shockwave-flash} -filter{crude-parental}
3331 +filter{html-annoyances} +filter{js-annoyances} +filter{content-cookies}
3332 +filter{webbugs} +filter{refresh-tags} +filter{nimda} +filter{banners-by-size}
3333 +hide-forwarded-for-headers +hide-from-header{block} +hide-referer{forge}
3334 -hide-user-agent -handle-as-image +set-image-blocker{pattern} -limit-connect
3335 +prevent-compression +session-cookies-only -prevent-reading-cookies
3336 -prevent-setting-cookies -kill-popups -send-vanilla-wafer -send-wafer }
3339 { -session-cookies-only }
3346 (no matches in this file)
3348 This tells us how we have defined our "actions", and which ones match for our
3349 example, "google.com". The first listing is any matches for the standard.action
3350 file. No hits at all here on "standard". Then next is "default", or our
3351 default.action file. The large, multi-line listing, is how the actions are set
3352 to match for all URLs, i.e. our default settings. If you look at your "actions"
3353 file, this would be the section just below the "aliases" section near the top.
3354 This will apply to all URLs as signified by the single forward slash at the end
3355 of the listing -- "/".
3357 But we can define additional actions that would be exceptions to these general
3358 rules, and then list specific URLs (or patterns) that these exceptions would
3359 apply to. Last match wins. Just below this then are two explicit matches for
3360 ".google.com". The first is negating our previous cookie setting, which was for
3361 "+session-cookies-only" (i.e. not persistent). So we will allow persistent
3362 cookies for google. The second turns off any "+fast-redirects" action, allowing
3363 this to take place unmolested. Note that there is a leading dot here --
3364 ".google.com". This will match any hosts and sub-domains, in the google.com
3365 domain also, such as "www.google.com". So, apparently, we have these two
3366 actions defined somewhere in the lower part of our default.action file, and
3367 "google.com" is referenced somewhere in these latter sections.
3369 Then, for our user.action file, we again have no hits.
3371 And finally we pull it all together in the bottom section and summarize how
3372 Privoxy is applying all its "actions" to "google.com":
3375 -add-header -block +deanimate-gifs{last} -downgrade-http-version -fast-redirects
3376 -filter{popups} -filter{fun} -filter{shockwave-flash} -filter{crude-parental}
3377 +filter{html-annoyances} +filter{js-annoyances} +filter{content-cookies}
3378 +filter{webbugs} +filter{refresh-tags} +filter{nimda} +filter{banners-by-size}
3379 +hide-forwarded-for-headers +hide-from-header{block} +hide-referer{forge}
3380 -hide-user-agent -handle-as-image +set-image-blocker{pattern} -limit-connect
3381 +prevent-compression -session-cookies-only -prevent-reading-cookies
3382 -prevent-setting-cookies -kill-popups -send-vanilla-wafer -send-wafer
3384 Notice the only difference here to the previous listing, is to "fast-redirects"
3385 and "session-cookies-only".
3387 Now another example, "ad.doubleclick.net":
3389 { +block +handle-as-image }
3392 { +block +handle-as-image }
3395 { +block +handle-as-image }
3398 We'll just show the interesting part here, the explicit matches. It is matched
3399 three different times. Each as an "+block +handle-as-image", which is the
3400 expanded form of one of our aliases that had been defined as: "+imageblock". (
3401 "Aliases" are defined in the first section of the actions file and typically
3402 used to combine more than one action.)
3404 Any one of these would have done the trick and blocked this as an unwanted
3405 image. This is unnecessarily redundant since the last case effectively would
3406 also cover the first. No point in taking chances with these guys though ;-)
3407 Note that if you want an ad or obnoxious URL to be invisible, it should be
3408 defined as "ad.doubleclick.net" is done here -- as both a "+block" and an
3409 "+handle-as-image". The custom alias "+imageblock" just simplifies the process
3410 and make it more readable.
3412 One last example. Let's try "http://www.rhapsodyk.net/adsl/HOWTO/". This one is
3413 giving us problems. We are getting a blank page. Hmmm...
3415 Matches for http://www.rhapsodyk.net/adsl/HOWTO/:
3417 { -add-header -block +deanimate-gifs -downgrade-http-version +fast-redirects
3418 +filter{html-annoyances} +filter{js-annoyances} +filter{kill-popups}
3419 +filter{webbugs} +filter{nimda} +filter{banners-by-size} +filter{hal}
3420 +filter{fun} +hide-forwarded-for-headers +hide-from-header{block}
3421 +hide-referer{forge} -hide-user-agent -handle-as-image +set-image-blocker{blank}
3422 +prevent-compression +session-cookies-only -prevent-setting-cookies
3423 -prevent-reading-cookies +kill-popups -send-vanilla-wafer -send-wafer }
3426 { +block +handle-as-image }
3429 Ooops, the "/adsl/" is matching "/ads"! But we did not want this at all! Now we
3430 see why we get the blank page. We could now add a new action below this that
3431 explicitly does not block ("{-block}") paths with "adsl". There are various
3432 ways to handle such exceptions. Example:
3437 Now the page displays ;-) Be sure to flush your browser's caches when making
3438 such changes. Or, try using Shift+Reload.
3440 But now what about a situation where we get no explicit matches like we did
3443 { +block +handle-as-image }
3446 That actually was very telling and pointed us quickly to where the problem was.
3447 If you don't get this kind of match, then it means one of the default rules in
3448 the first section is causing the problem. This would require some guesswork,
3449 and maybe a little trial and error to isolate the offending rule. One likely
3450 cause would be one of the "{+filter}" actions. Try adding the URL for the site
3451 to one of aliases that turn off "+filter":
3455 .worldpay.com # for quietpc.com
3460 "{shop}" is an "alias" that expands to "{ -filter -session-cookies-only }". Or
3461 you could do your own exception to negate filtering:
3466 This would probably be most appropriately put in user.action, for local site
3469 "{fragile}" is an alias that disables most actions. This can be used as a last
3470 resort for problem sites. Remember to flush caches! If this still does not
3471 work, you will have to go through the remaining actions one by one to find
3472 which one(s) is causing the problem.
projects / privoxy.git / blob