5 $Id: user-manual.sgml,v 1.92 2002/04/25 18:55:13 hal9 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 -------------------------------------------------------------------------------
34 3.1.1. Red Hat and SuSE RPMs
37 3.1.4. Solaris, NetBSD, FreeBSD, HP-UX
42 3.2. Building from Source
44 4. Quickstart to Using Privoxy
46 4.1. Note to Upgraders
48 4.3. Command Line Options
50 5. Privoxy Configuration
52 5.1. Controlling Privoxy with Your Web Browser
53 5.2. Configuration Files Overview
54 5.3. The Main Configuration File
56 5.3.1. Configuration and Log File Locations
57 5.3.2. Local Set-up Documentation
59 5.3.4. Access Control and Security
61 5.3.6. Windows GUI Options
65 5.4.1. Finding the Right Mix
67 5.4.3. How Actions are Applied to URLs
75 6. Contacting the Developers, Bug Reporting and Feature Requests
77 6.1. Submitting Ads and "Action" Problems
79 7. Copyright and History
87 9.1. Regular Expressions
88 9.2. Privoxy's Internal Pages
93 9.4. Anatomy of an Action
95 -------------------------------------------------------------------------------
99 This documentation is included with the current beta version of Privoxy,
100 v.2.9.14, and is mostly complete at this point. The most up to date reference
101 for the time being is still the comments in the source files and in the
102 individual configuration files. Development of version 3.0 is currently nearing
103 completion, and includes many significant changes and enhancements over earlier
104 versions. The target release date for stable v3.0 is "soon" ;-).
106 Since this is a beta version, not all new features are well tested. This
107 documentation may be slightly out of sync as a result (especially with CVS
108 sources). And there may be bugs, though hopefully not many!
110 -------------------------------------------------------------------------------
114 In addition to Internet Junkbuster's traditional features of ad and banner
115 blocking and cookie management, Privoxy provides new features, some of them
116 currently under development:
118 * Integrated browser based configuration and control utility at http://
119 config.privoxy.org/ (shortcut: http://p.p/). Browser-based tracing of rule
120 and filter effects. Remote toggling.
122 * Blocking of annoying pop-up browser windows.
124 * HTTP/1.1 compliant (but not all optional 1.1 features are supported).
126 * Support for Perl Compatible Regular Expressions in the configuration files,
127 and generally a more sophisticated and flexible configuration syntax over
132 * Web page content filtering (removes banners based on size, invisible
133 "web-bugs", JavaScript and HTML annoyances, pop-ups, etc.)
135 * Bypass many click-tracking scripts (avoids script redirection).
137 * Multi-threaded (POSIX and native threads).
139 * Auto-detection and re-reading of config file changes.
141 * User-customizable HTML templates (e.g. 404 error page).
143 * Improved cookie management features (e.g. session based cookies).
145 * Improved signal handling, and a true daemon mode (Unix).
147 * Builds from source on most UNIX-like systems. Packages available for: Linux
148 (RedHat, SuSE, or Debian), Windows, Sun Solaris, Mac OSX, OS/2, HP-UX 11,
151 * Every feature now controllable on a per-site or per-location basis,
152 configuration more powerful and versatile over-all.
154 * Many smaller new features added, limitations and bugs removed, and security
157 -------------------------------------------------------------------------------
161 Privoxy is available both in convenient pre-compiled packages for a wide range
162 of operating systems, and as raw source code. For most users, we recommend
163 using the packages, which can be downloaded from our Privoxy Project Page.
165 If you like to live on the bleeding edge and are not afraid of using possibly
166 unstable development versions, you can check out the up-to-the-minute version
167 directly from the CVS repository or simply download the nightly CVS tarball.
169 At present, Privoxy is known to run on Win32, Mac OSX, OS/2, AmigaOS, Linux
170 (RedHat, Suse, Debian), FreeBSD, NetBSD, BeOS, and many flavors of Unix.
172 -------------------------------------------------------------------------------
176 Note: If you have a previous Junkbuster or Privoxy installation on your system,
177 you will need to remove it. Some platforms do this for you as part of their
178 installation procedure. (See below for your platform).
180 In any case be sure to backup your old configuration if it is valuable to you.
181 See the note to upgraders.
183 How to install the binary packages depends on your operating system:
185 -------------------------------------------------------------------------------
187 3.1.1. Red Hat and SuSE RPMs
189 RPMs can be installed with rpm -Uvh privoxy-2.9.14-1.rpm, and will use /etc/
190 privoxy for the location of configuration files.
192 Note that on Red Hat, Privoxy will not be automatically started on system boot.
193 You will need to enable that using chkconfig, ntsysv, or similar method.
195 If you have problems with failed dependencies, try rebuilding the SRC RPM: rpm
196 --rebuild privoxy-2.9.14-1.src.rpm;. This will use your locally installed
197 libraries and RPM version.
199 Also note that if you have a Junkbuster RPM installed on your system, you need
200 to remove it first, because the packages conflict. Otherwise, RPM will try to
201 remove Junkbuster automatically, before installing Privoxy.
203 -------------------------------------------------------------------------------
209 -------------------------------------------------------------------------------
213 Just double-click the installer, which will guide you through the installation
216 -------------------------------------------------------------------------------
218 3.1.4. Solaris, NetBSD, FreeBSD, HP-UX
220 Create a new directory, cd to it, then unzip and untar the archive. For the
221 most part, you'll have to figure out where things go. FIXME.
223 -------------------------------------------------------------------------------
227 First, make sure that no previous installations of Junkbuster and / or Privoxy
228 are left on your system. You can do this by
230 Then, just double-click the WarpIN self-installing archive, which will guide
231 you through the installation process. A shadow of the Privoxy executable will
232 be placed in your startup folder so it will start automatically whenever OS/2
235 The directory you choose to install Privoxy into will contain all of the
238 -------------------------------------------------------------------------------
242 Unzip the downloaded package (you can either double-click on the file in the
243 finder, or on the desktop if you downloaded it there). Then, double-click on
244 the package installer icon and follow the installation process. Privoxy will be
245 installed in the subdirectory /Applications/Privoxy.app. Privoxy will set
246 itself up to start automatically on system bring-up via /System/Library/
247 StartupItems/Privoxy.
249 -------------------------------------------------------------------------------
253 Copy and then unpack the lha archive to a suitable location. All necessary
254 files will be installed into Privoxy directory, including all configuration and
255 log files. To uninstall, just remove this directory.
257 Start Privoxy (with RUN <>NIL:) in your startnet script (AmiTCP), in s:
258 user-startup (RoadShow), as startup program in your startup script (Genesis),
259 or as startup action (Miami and MiamiDx). Privoxy will automatically quit when
260 you quit your TCP/IP stack (just ignore the harmless warning your TCP/IP stack
261 may display that Privoxy is still running).
263 -------------------------------------------------------------------------------
265 3.2. Building from Source
267 To build Privoxy from source, autoheader, autoconf, GNU make (gmake), and, of
268 course, a C compiler are required.
270 When building from a source tarball (either release version or nightly CVS
271 tarball), first unpack the source:
273 tar xzvf privoxy-2.9.14-beta-src* [.tgz or .tar.gz]
274 cd privoxy-2.9.14-beta
277 For retrieving the current CVS sources, you'll need CVS installed. Note that
278 sources from CVS are development quality, and may not be stable, or well
279 tested. To download CVS source:
281 cvs -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa login
282 cvs -z3 -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa co current
286 This will create a directory named current/, which will contain the source
289 Then, in either case, to build from unpacked tarball or CVS source:
293 ./configure # (--help to see options)
294 make # (the make from gnu, gmake for *BSD)
296 make -n install # (to see where all the files will go)
297 make install # (to really install)
300 If you have gnu make, you can have the first four steps automatically done for
306 in the freshly downloaded or unpacked source directory.
308 For more detailed instructions on how to build Redhat and SuSE RPMs, Windows
309 self-extracting installers, building on platforms with special requirements
310 etc, please consult the developer manual.
312 -------------------------------------------------------------------------------
314 4. Quickstart to Using Privoxy
316 4.1. Note to Upgraders
318 There are very significant changes from older versions of Junkbuster to the
319 current Privoxy. Configuration is substantially changed. Junkbuster 2.0.x and
320 earlier configuration files will not migrate. The functionality of the old
321 blockfile, cookiefile and imagelist, are now combined into the "actions files".
322 default.action, is the main actions file. Local exceptions should best be put
325 A "filter file" (typically default.filter) is new as of Privoxy 2.9.x, and
326 provides some of the new sophistication (explained below). config is much the
329 If upgrading from a 2.0.x version, you will have to use the new config files,
330 and possibly adapt any personal rules from your older files. When porting
331 personal rules over from the old blockfile to the new actions files, please
332 note that even the pattern syntax has changed. If upgrading from 2.9.x
333 development versions, it is still recommended to use the new configuration
336 A quick list of things to be aware of before upgrading:
338 * The default listening port is now 8118 due to a conflict with another
341 * Some installers may remove earlier versions completely. Save any important
344 * Privoxy is controllable with a web browser at the special URL: http://
345 config.privoxy.org/ (Shortcut: http://p.p/). Many aspects of configuration
346 can be done here, including temporarily disabling Privoxy.
348 * The primary configuration file for cookie management, ad and banner
349 blocking, and many other aspects of Privoxy configuration is in the
350 "actions" files. It is strongly recommended to become familiar with the new
351 actions concept below, before modifying these files. Locally defined rules
352 should go into user.action.
354 * Some installers may not automatically start Privoxy after installation.
356 -------------------------------------------------------------------------------
358 4.2. Starting Privoxy
360 Before launching Privoxy for the first time, you will want to configure your
361 browser(s) to use Privoxy as a HTTP and HTTPS proxy. The default is localhost
362 for the proxy address, and port 8118 (earlier versions used port 8000). This is
363 the one configuration step that must be done!
365 With Netscape (and Mozilla), this can be set under Edit -> Preferences ->
366 Advanced -> Proxies -> HTTP Proxy. For Internet Explorer: Tools -> Internet
367 Properties -> Connections -> LAN Setting. Then, check "Use Proxy" and fill in
368 the appropriate info (Address: localhost, Port: 8118). Include if HTTPS proxy
371 After doing this, flush your browser's disk and memory caches to force a
372 re-reading of all pages and to get rid of any ads that may be cached. You are
373 now ready to start enjoying the benefits of using Privoxy!
375 Privoxy is typically started by specifying the main configuration file to be
376 used on the command line. Example Unix startup command:
379 # /usr/sbin/privoxy /etc/privoxy/config
383 See below for other command line options.
385 An init script is provided for SuSE and Red Hat.
387 For for SuSE: rcprivoxy start
389 For Red Hat and Debian: /etc/rc.d/init.d/privoxy start
391 If no configuration file is specified on the command line, Privoxy will look
392 for a file named config in the current directory. Except on Win32 where it will
393 try config.txt. If no file is specified on the command line and no default
394 configuration file can be found, Privoxy will fail to start.
396 The included default configuration files should give a reasonable starting
397 point. Most of the per site configuration is done in the "actions" files. These
398 are where various cookie actions are defined, ad and banner blocking, and other
399 aspects of Privoxy configuration. There are several such files included, with
400 varying levels of aggressiveness.
402 You will probably want to keep an eye out for sites for which you may prefer
403 persistent cookies, and add these to your actions configuration as needed. By
404 default, most of these will be accepted only during the current browser session
405 (aka "session cookies"), unless you add them to the configuration. If you want
406 the browser to handle this instead, you will need to edit user.action (or
407 through the web based interface) and disable this feature. If you use more than
408 one browser, it would make more sense to let Privoxy handle this. In which
409 case, the browser(s) should be set to accept all cookies.
411 Another feature where you will probably want to define exceptions for trusted
412 sites is the popup-killing (through the +popup and +filter{popups} actions),
413 because your favorite shopping, banking, or leisure site may need popups
416 Privoxy is HTTP/1.1 compliant, but not all of the optional 1.1 features are as
417 yet supported. In the unlikely event that you experience inexplicable problems
418 with browsers that use HTTP/1.1 per default (like Mozilla or recent versions of
419 I.E.), you might try to force HTTP/1.0 compatibility. For Mozilla, look under
420 Edit -> Preferences -> Debug -> Networking. Alternatively, set the
421 "+downgrade-http-version" config option in default.action which will downgrade
422 your browser's HTTP requests from HTTP/1.1 to HTTP/1.0 before processing them.
424 After running Privoxy for a while, you can start to fine tune the configuration
425 to suit your personal, or site, preferences and requirements. There are many,
426 many aspects that can be customized. "Actions" can be adjusted by pointing your
427 browser to http://config.privoxy.org/ (shortcut: http://p.p/), and then follow
428 the link to "View & Change the Current Configuration". (This is an internal
429 page and does not require Internet access.)
431 In fact, various aspects of Privoxy configuration can be viewed from this page,
432 including current configuration parameters, source code version numbers, the
433 browser's request headers, and "actions" that apply to a given URL. In addition
434 to the actions file editor mentioned above, Privoxy can also be turned "on" and
435 "off" (toggled) from this page.
437 If you encounter problems, try loading the page without Privoxy. If that helps,
438 enter the URL where you have the problems into the browser based rule tracing
439 utility. See which rules apply and why, and then try turning them off for that
440 site one after the other, until the problem is gone. When you have found the
441 culprit, you might want to turn the rest on again.
443 If the above paragraph sounds gibberish to you, you might want to read more
444 about the actions concept or even dive deep into the Appendix on actions.
446 If you can't get rid of the problem at all, think you've found a bug in
447 Privoxy, want to propose a new feature or smarter rules, please see the section
448 "Contacting the Developers" below.
450 -------------------------------------------------------------------------------
452 4.3. Command Line Options
454 Privoxy may be invoked with the following command-line options:
458 Print version info and exit. Unix only.
462 Print short usage info and exit. Unix only.
466 Don't become a daemon, i.e. don't fork and become process group leader, and
467 don't detach from controlling tty. Unix only.
471 On startup, write the process ID to FILE. Delete the FILE on exit. Failure
472 to create or delete the FILE is non-fatal. If no FILE option is given, no
473 PID file will be used. Unix only.
475 * --user USER[.GROUP]
477 After (optionally) writing the PID file, assume the user ID of USER, and if
478 included the GID of GROUP. Exit if the privileges are not sufficient to do
483 If no configfile is included on the command line, Privoxy will look for a
484 file named "config" in the current directory (except on Win32 where it will
485 look for "config.txt" instead). Specify full path to avoid confusion. If no
486 config file is found, Privoxy will fail to start.
488 -------------------------------------------------------------------------------
490 5. Privoxy Configuration
492 All Privoxy configuration is stored in text files. These files can be edited
493 with a text editor. Many important aspects of Privoxy can also be controlled
494 easily with a web browser.
496 -------------------------------------------------------------------------------
498 5.1. Controlling Privoxy with Your Web Browser
500 Privoxy's user interface can be reached through the special URL http://
501 config.privoxy.org/ (shortcut: http://p.p/), which is a built-in page and works
502 without Internet access. You will see the following section:
505 ? View & change the current configuration
506 ? View the source code version numbers
507 ? View the request headers.
508 ? Look up which actions apply to a URL and why
509 ? Toggle Privoxy on or off
512 This should be self-explanatory. Note the first item leads to an editor for the
513 "actions list", which is where the ad, banner, cookie, and URL blocking magic
514 is configured as well as other advanced features of Privoxy. This is an easy
515 way to adjust various aspects of Privoxy configuration. The actions file, and
516 other configuration files, are explained in detail below.
518 "Toggle Privoxy On or Off" is handy for sites that might have problems with
519 your current actions and filters. You can in fact use it as a test to see
520 whether it is Privoxy causing the problem or not. Privoxy continues to run as a
521 proxy in this case, but all filtering is disabled. There is even a toggle
522 Bookmarklet offered, so that you can toggle Privoxy with one click from your
525 -------------------------------------------------------------------------------
527 5.2. Configuration Files Overview
529 For Unix, *BSD and Linux, all configuration files are located in /etc/privoxy/
530 by default. For MS Windows, OS/2, and AmigaOS these are all in the same
531 directory as the Privoxy executable. The name and number of configuration files
532 has changed from previous versions, and is subject to change as development
535 The installed defaults provide a reasonable starting point, though some
536 settings may be aggressive by some standards. For the time being, the principle
537 configuration files are:
539 * The main configuration file is named config on Linux, Unix, BSD, OS/2, and
540 AmigaOS and config.txt on Windows. This is a required file.
542 * default.action (the main actions file) is used to define the default
543 settings for various "actions" relating to images, banners, pop-ups, access
544 restrictions, banners and cookies.
546 Multiple actions files may be defined in config. These are processed in the
547 order they are defined. Local customizations and locally preferred
548 exceptions to the default policies as defined in default.action are
549 probably best applied in user.action, which should be preserved across
550 upgrades. standard.action is also included. This is mostly for Privoxy's
553 There is also a web based editor that can be accessed from http://
554 config.privoxy.org/show-status/ (Shortcut: http://p.p/show-status/) for the
555 various actions files.
557 * default.filter (the filter file) can be used to re-write the raw page
558 content, including viewable text as well as embedded HTML and JavaScript,
559 and whatever else lurks on any given web page. The filtering jobs are only
560 pre-defined here; whether to apply them or not is up to the actions files.
562 All files use the "#" character to denote a comment (the rest of the line will
563 be ignored) and understand line continuation through placing a backslash ("\")
564 as the very last character in a line. If the # is preceded by a backslash, it
565 looses its special function. Placing a # in front of an otherwise valid
566 configuration line to prevent it from being interpreted is called "commenting
569 The actions files and default.filter can use Perl style regular expressions for
572 After making any changes, there is no need to restart Privoxy in order for the
573 changes to take effect. Privoxy detects such changes automatically. Note,
574 however, that it may take one or two additional requests for the change to take
575 effect. When changing the listening address of Privoxy, these "wake up"
576 requests must obviously be sent to the old listening address.
578 While under development, the configuration content is subject to change. The
579 below documentation may not be accurate by the time you read this. Also, what
580 constitutes a "default" setting, may change, so please check all your
581 configuration files on important issues.
583 -------------------------------------------------------------------------------
585 5.3. The Main Configuration File
587 Again, the main configuration file is named config on Linux/Unix/BSD and OS/2,
588 and config.txt on Windows. Configuration lines consist of an initial keyword
589 followed by a list of values, all separated by whitespace (any number of spaces
590 or tabs). For example:
595 Assigns the value /etc/privoxy to the option confdir and thus indicates that
596 the configuration directory is named "/etc/privoxy/".
598 All options in the config file except for confdir and logdir are optional.
599 Watch out in the below description for what happens if you leave them unset.
601 The main config file controls all aspects of Privoxy's operation that are not
602 location dependent (i.e. they apply universally, no matter where you may be
605 -------------------------------------------------------------------------------
607 5.3.1. Configuration and Log File Locations
609 Privoxy can (and normally does) use a number of other files for additional
610 configuration and logging. This section of the configuration file tells Privoxy
611 where to find those other files.
613 -------------------------------------------------------------------------------
619 The directory where the other configuration files are located
627 /etc/privoxy (Unix) or Privoxy installation dir (Windows)
635 No trailing "/", please
637 When development goes modular and multi-user, the blocker, filter, and
638 per-user config will be stored in subdirectories of "confdir". For now, the
639 configuration directory structure is flat, except for confdir/templates,
640 where the HTML templates for CGI output reside (e.g. Privoxy's 404 error
643 -------------------------------------------------------------------------------
649 The directory where all logging takes place (i.e. where logfile and jarfile
658 /var/log/privoxy (Unix) or Privoxy installation dir (Windows)
666 No trailing "/", please
668 -------------------------------------------------------------------------------
674 The actions file(s) to use
678 File name, relative to confdir
682 standard # Internal purposes, recommended not editing
684 default # Main actions file
686 user # User customizations
690 No actions are taken at all. Simple neutral proxying.
694 Multiple actionsfile lines are OK and are in fact recommended!
696 The default values include standard.action, which is used for internal
697 purposes and should be loaded, default.action, which is the "main" actions
698 file maintained by the developers, and user.action, where you can make your
701 There is no point in using Privoxy without an actions file.
703 -------------------------------------------------------------------------------
709 The filter file to use
713 File name, relative to confdir
717 default.filter (Unix) or default.filter.txt (Windows)
721 No textual content filtering takes place, i.e. all +filter{name} actions in
722 the actions files are turned off
726 The "default.filter" file contains content modification rules that use
727 "regular expressions". These rules permit powerful changes on the content
728 of Web pages, e.g., you could disable your favorite JavaScript annoyances,
729 re-write the actual displayed text, or just have some fun replacing
730 "Microsoft" with "MicroSuck" wherever it appears on a Web page.
732 -------------------------------------------------------------------------------
742 File name, relative to logdir
746 logfile (Unix) or privoxy.log (Windows)
750 No log file is used, all log messages go to the console (stderr).
754 The windows version will additionally log to the console.
756 The logfile is where all logging and error messages are written. The level
757 of detail and number of messages are set with the debug option (see below).
758 The logfile can be useful for tracking down a problem with Privoxy (e.g.,
759 it's not blocking an ad you think it should block) but in most cases you
760 probably will never look at it.
762 Your logfile will grow indefinitely, and you will probably want to
763 periodically remove it. On Unix systems, you can do this with a cron job
764 (see "man cron"). For Red Hat, a logrotate script has been included.
766 On SuSE Linux systems, you can place a line like "/var/log/privoxy.* +1024k
767 644 nobody.nogroup" in /etc/logfiles, with the effect that cron.daily will
768 automatically archive, gzip, and empty the log, when it exceeds 1M size.
770 -------------------------------------------------------------------------------
776 The file to store intercepted cookies in
780 File name, relative to logdir
784 jarfile (Unix) or privoxy.jar (Windows)
788 Intercepted cookies are not stored at all.
792 The jarfile may grow to ridiculous sizes over time.
794 -------------------------------------------------------------------------------
800 The trust file to use
804 File name, relative to confdir
808 Unset (commented out). When activated: trust (Unix) or trust.txt (Windows)
812 The whole trust mechanism is turned off.
816 The trust mechanism is an experimental feature for building white-lists and
817 should be used with care. It is NOT recommended for the casual user.
819 If you specify a trust file, Privoxy will only allow access to sites that
820 are named in the trustfile. You can also mark sites as trusted referrers
821 (with +), with the effect that access to untrusted sites will be granted,
822 if a link from a trusted referrer was used. The link target will then be
823 added to the "trustfile". Possible applications include limiting Internet
826 If you use + operator in the trust file, it may grow considerably over
829 -------------------------------------------------------------------------------
831 5.3.2. Local Set-up Documentation
833 If you intend to operate Privoxy for more users that just yourself, it might be
834 a good idea to let them know how to reach you, what you block and why you do
835 that, your policies etc.
837 -------------------------------------------------------------------------------
839 5.3.2.1. trust-info-url
843 A URL to be displayed in the error page that users will see if access to an
844 untrusted page is denied.
852 Two example URL are provided
856 No links are displayed on the "untrusted" error page.
860 The value of this option only matters if the experimental trust mechanism
861 has been activated. (See trustfile above.)
863 If you use the trust mechanism, it is a good idea to write up some on-line
864 documentation about your trust policy and to specify the URL(s) here. Use
865 multiple times for multiple URLs.
867 The URL(s) should be added to the trustfile as well, so users don't end up
868 locked out from the information on why they were locked out in the first
871 -------------------------------------------------------------------------------
873 5.3.2.2. admin-address
877 An email address to reach the proxy administrator.
889 No email address is displayed on error pages and the CGI user interface.
893 If both admin-address and proxy-info-url are unset, the whole "Local
894 Privoxy Support" box on all generated pages will not be shown.
896 -------------------------------------------------------------------------------
898 5.3.2.3. proxy-info-url
902 A URL to documentation about the local Privoxy setup, configuration or
915 No link to local documentation is displayed on error pages and the CGI user
920 If both admin-address and proxy-info-url are unset, the whole "Local
921 Privoxy Support" box on all generated pages will not be shown.
923 This URL shouldn't be blocked ;-)
925 -------------------------------------------------------------------------------
929 These options are mainly useful when tracing a problem. Note that you might
930 also want to invoke Privoxy with the --no-daemon command line option when
933 -------------------------------------------------------------------------------
939 Key values that determine what information gets logged.
947 12289 (i.e.: URLs plus informational and warning messages)
955 The available debug levels are:
957 debug 1 # show each GET/POST/CONNECT request
958 debug 2 # show each connection status
959 debug 4 # show I/O status
960 debug 8 # show header parsing
961 debug 16 # log all data into the logfile
962 debug 32 # debug force feature
963 debug 64 # debug regular expression filter
964 debug 128 # debug fast redirects
965 debug 256 # debug GIF de-animation
966 debug 512 # Common Log Format
967 debug 1024 # debug kill pop-ups
968 debug 4096 # Startup banner and warnings.
969 debug 8192 # Non-fatal errors
972 To select multiple debug levels, you can either add them or use multiple
975 A debug level of 1 is informative because it will show you each request as
976 it happens. 1, 4096 and 8192 are highly recommended so that you will notice
977 when things go wrong. The other levels are probably only of interest if you
978 are hunting down a specific problem. They can produce a hell of an output
981 The reporting of fatal errors (i.e. ones which crash Privoxy) is always on
982 and cannot be disabled.
984 If you want to use CLF (Common Log Format), you should set "debug 512" ONLY
985 and not enable anything else.
987 -------------------------------------------------------------------------------
989 5.3.3.2. single-threaded
993 Whether to run only one server thread
1005 Multi-threaded (or, where unavailable: forked) operation, i.e. the ability
1006 to serve multiple requests simultaneously.
1010 This option is only there for debug purposes and you should never need to
1011 use it. It will drastically reduce performance.
1013 -------------------------------------------------------------------------------
1015 5.3.4. Access Control and Security
1017 This section of the config file controls the security-relevant aspects of
1018 Privoxy's configuration.
1020 -------------------------------------------------------------------------------
1022 5.3.4.1. listen-address
1026 The IP address and TCP port on which Privoxy will listen for client
1039 Bind to localhost (127.0.0.1), port 8118. This is suitable and recommended
1040 for home users who run Privoxy on the same machine as their browser.
1044 You will need to configure your browser(s) to this proxy address and port.
1046 If you already have another service running on port 8118, or if you want to
1047 serve requests from other machines (e.g. on your local network) as well,
1048 you will need to override the default.
1050 If you leave out the IP address, Privoxy will bind to all interfaces
1051 (addresses) on your machine and may become reachable from the Internet. In
1052 that case, consider using access control lists (ACL's) (see "ACLs" below),
1057 Suppose you are running Privoxy on a machine which has the address
1058 192.168.0.1 on your local private network (192.168.0.0) and has another
1059 outside connection with a different address. You want it to serve requests
1062 listen-address 192.168.0.1:8118
1065 -------------------------------------------------------------------------------
1071 Initial state of "toggle" status
1083 Act as if toggled on
1087 If set to 0, Privoxy will start in "toggled off" mode, i.e. behave like a
1088 normal, content-neutral proxy. See enable-remote-toggle below. This is not
1089 really useful anymore, since toggling is much easier via the web interface
1090 then via editing the conf file.
1092 The windows version will only display the toggle icon in the system tray if
1093 this option is present.
1095 -------------------------------------------------------------------------------
1097 5.3.4.3. enable-remote-toggle
1101 Whether or not the web-based toggle feature may be used
1113 The web-based toggle feature is disabled.
1117 When toggled off, Privoxy acts like a normal, content-neutral proxy, i.e.
1118 it acts as if none of the actions applied to any URL.
1120 For the time being, access to the toggle feature can not be controlled
1121 separately by "ACLs" or HTTP authentication, so that everybody who can
1122 access Privoxy (see "ACLs" and listen-address above) can toggle it for all
1123 users. So this option is not recommended for multi-user environments with
1126 Note that you must have compiled Privoxy with support for this feature,
1127 otherwise this option has no effect.
1129 -------------------------------------------------------------------------------
1131 5.3.4.4. enable-edit-actions
1135 Whether or not the web-based actions file editor may be used
1147 The web-based actions file editor is disabled.
1151 For the time being, access to the editor can not be controlled separately
1152 by "ACLs" or HTTP authentication, so that everybody who can access Privoxy
1153 (see "ACLs" and listen-address above) can modify its configuration for all
1154 users. So this option is not recommended for multi-user environments with
1157 Note that you must have compiled Privoxy with support for this feature,
1158 otherwise this option has no effect.
1160 -------------------------------------------------------------------------------
1162 5.3.4.5. ACLs: permit-access and deny-access
1166 Who can access what.
1170 src_addr[/src_masklen] [dst_addr[/dst_masklen]]
1172 Where src_addr and dst_addr are IP addresses in dotted decimal notation or
1173 valid DNS names, and src_masklen and dst_masklen are subnet masks in CIDR
1174 notation, i.e. integer values from 2 to 30 representing the length (in
1175 bits) of the network address. The masks and the whole destination part are
1184 Don't restrict access further than implied by listen-address
1188 Access controls are included at the request of ISPs and systems
1189 administrators, and are not usually needed by individual users. For a
1190 typical home user, it will normally suffice to ensure that Privoxy only
1191 listens on the localhost or internal (home) network address by means of the
1192 listen-address option.
1194 Please see the warnings in the FAQ that this proxy is not intended to be a
1195 substitute for a firewall or to encourage anyone to defer addressing basic
1196 security weaknesses.
1198 Multiple ACL lines are OK. If any ACLs are specified, then the Privoxy
1199 talks only to IP addresses that match at least one permit-access line and
1200 don't match any subsequent deny-access line. In other words, the last match
1201 wins, with the default being deny-access.
1203 If Privoxy is using a forwarder (see forward below) for a particular
1204 destination URL, the dst_addr that is examined is the address of the
1205 forwarder and NOT the address of the ultimate target. This is necessary
1206 because it may be impossible for the local Privoxy to determine the IP
1207 address of the ultimate target (that's often what gateways are used for).
1209 You should prefer using IP addresses over DNS names, because the address
1210 lookups take time. All DNS names must resolve! You can not use domain
1211 patterns like "*.org" or partial domain names. If a DNS name resolves to
1212 multiple IP addresses, only the first one is used.
1214 Denying access to particular sites by ACL may have undesired side effects
1215 if the site in question is hosted on a machine which also hosts other
1220 Explicitly define the default behavior if no ACL and listen-address are
1221 set: "localhost" is OK. The absence of a dst_addr implies that all
1222 destination addresses are OK:
1224 permit-access localhost
1227 Allow any host on the same class C subnet as www.privoxy.org access to
1228 nothing but www.example.com:
1230 permit-access www.privoxy.org/24 www.example.com/32
1233 Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere,
1234 with the exception that 192.168.45.73 may not access
1235 www.dirty-stuff.example.com:
1237 permit-access 192.168.45.64/26
1238 deny-access 192.168.45.73 www.dirty-stuff.example.com
1241 -------------------------------------------------------------------------------
1243 5.3.4.6. buffer-limit
1247 Maximum size of the buffer for content filtering.
1259 Use a 4MB (4096 KB) limit.
1263 For content filtering, i.e. the +filter and +deanimate-gif actions, it is
1264 necessary that Privoxy buffers the entire document body. This can be
1265 potentially dangerous, since a server could just keep sending data
1266 indefinitely and wait for your RAM to exhaust -- with nasty consequences.
1269 When a document buffer size reaches the buffer-limit, it is flushed to the
1270 client unfiltered and no further attempt to filter the rest of the document
1271 is made. Remember that there may be multiple threads running, which might
1272 require up to buffer-limit Kbytes each, unless you have enabled
1273 "single-threaded" above.
1275 -------------------------------------------------------------------------------
1279 This feature allows routing of HTTP requests through a chain of multiple
1280 proxies. It can be used to better protect privacy and confidentiality when
1281 accessing specific domains by routing requests to those domains through an
1282 anonymous public proxy (see e.g. http://www.multiproxy.org/anon_list.htm) Or to
1283 use a caching proxy to speed up browsing. Or chaining to a parent proxy may be
1284 necessary because the machine that Privoxy runs on has no direct Internet
1287 Also specified here are SOCKS proxies. Privoxy supports the SOCKS 4 and SOCKS
1290 -------------------------------------------------------------------------------
1296 To which parent HTTP proxy specific requests should be routed.
1300 target_domain[:port] http_parent[/port]
1302 Where target_domain is a domain name pattern (see the chapter on domain
1303 matching in the default.action file), http_parent is the address of the
1304 parent HTTP proxy as an IP addresses in dotted decimal notation or as a
1305 valid DNS name (or "." to denote "no forwarding", and the optional port
1306 parameters are TCP ports, i.e. integer values from 1 to 64535
1314 Don't use parent HTTP proxies.
1318 If http_parent is ".", then requests are not forwarded to another HTTP
1319 proxy but are made directly to the web servers.
1321 Multiple lines are OK, they are checked in sequence, and the last match
1326 Everything goes to an example anonymizing proxy, except SSL on port 443
1327 (which it doesn't handle):
1329 forward .* anon-proxy.example.org:8080
1333 Everything goes to our example ISP's caching proxy, except for requests to
1336 forward .*. caching-proxy.example-isp.net:8000
1337 forward .example-isp.net .
1340 -------------------------------------------------------------------------------
1342 5.3.5.2. forward-socks4 and forward-socks4a
1346 Through which SOCKS proxy (and to which parent HTTP proxy) specific
1347 requests should be routed.
1351 target_domain[:port] socks_proxy[/port] http_parent[/port]
1353 Where target_domain is a domain name pattern (see the chapter on domain
1354 matching in the default.action file), http_parent and socks_proxy are IP
1355 addresses in dotted decimal notation or valid DNS names (http_parent may be
1356 "." to denote "no HTTP forwarding"), and the optional port parameters are
1357 TCP ports, i.e. integer values from 1 to 64535
1365 Don't use SOCKS proxies.
1369 Multiple lines are OK, they are checked in sequence, and the last match
1372 The difference between forward-socks4 and forward-socks4a is that in the
1373 SOCKS 4A protocol, the DNS resolution of the target hostname happens on the
1374 SOCKS server, while in SOCKS 4 it happens locally.
1376 If http_parent is ".", then requests are not forwarded to another HTTP
1377 proxy but are made (HTTP-wise) directly to the web servers, albeit through
1382 From the company example.com, direct connections are made to all "internal"
1383 domains, but everything outbound goes through their ISP's proxy by way of
1384 example.com's corporate SOCKS 4A gateway to the Internet.
1386 forward-socks4a .*. socks-gw.example.com:1080 www-cache.example-isp.net:8080
1387 forward .example.com .
1390 A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent
1393 forward-socks4 .*. socks-gw.example.com:1080 .
1396 -------------------------------------------------------------------------------
1398 5.3.5.3. Advanced Forwarding Examples
1400 If you have links to multiple ISPs that provide various special content only to
1401 their subscribers, you can configure multiple Privoxies which have connections
1402 to the respective ISPs to act as forwarders to each other, so that your users
1403 can see the internal content of all ISPs.
1405 Assume that host-a has a PPP connection to isp-a.net. And host-b has a PPP
1406 connection to isp-b.net. Both run Privoxy. Their forwarding configuration can
1412 forward .isp-b.net host-b:8118
1418 forward .isp-a.net host-a:8118
1421 Now, your users can set their browser's proxy to use either host-a or host-b
1422 and be able to browse the internal content of both isp-a and isp-b.
1424 If you intend to chain Privoxy and squid locally, then chain as browser ->
1425 squid -> privoxy is the recommended way.
1427 Assuming that Privoxy and squid run on the same box, your squid configuration
1428 could then look like this:
1430 # Define Privoxy as parent proxy (without ICP)
1431 cache_peer 127.0.0.1 parent 8118 7 no-query
1433 # Define ACL for protocol FTP
1436 # Do not forward FTP requests to Privoxy
1437 always_direct allow ftp
1439 # Forward all the rest to Privoxy
1440 never_direct allow all
1443 You would then need to change your browser's proxy settings to squid's address
1444 and port. Squid normally uses port 3128. If unsure consult http_port in
1447 -------------------------------------------------------------------------------
1449 5.3.6. Windows GUI Options
1451 Privoxy has a number of options specific to the Windows GUI interface:
1453 If "activity-animation" is set to 1, the Privoxy icon will animate when
1454 "Privoxy" is active. To turn off, set to 0.
1456 activity-animation 1
1459 If "log-messages" is set to 1, Privoxy will log messages to the console window:
1464 If "log-buffer-size" is set to 1, the size of the log buffer, i.e. the amount
1465 of memory used for the log messages displayed in the console window, will be
1466 limited to "log-max-lines" (see below).
1468 Warning: Setting this to 0 will result in the buffer to grow infinitely and eat
1474 log-max-lines is the maximum number of lines held in the log buffer. See above.
1479 If "log-highlight-messages" is set to 1, Privoxy will highlight portions of the
1480 log messages with a bold-faced font:
1482 log-highlight-messages 1
1485 The font used in the console window:
1487 log-font-name Comic Sans MS
1490 Font size used in the console window:
1495 "show-on-task-bar" controls whether or not Privoxy will appear as a button on
1496 the Task bar when minimized:
1501 If "close-button-minimizes" is set to 1, the Windows close button will minimize
1502 Privoxy instead of closing the program (close with the exit option on the File
1505 close-button-minimizes 1
1508 The "hide-console" option is specific to the MS-Win console version of Privoxy.
1509 If this option is used, Privoxy will disconnect from and hide the command
1515 -------------------------------------------------------------------------------
1519 The actions files are used to define what actions Privoxy takes for which URLs,
1520 and thus determines how ad images, cookies and various other aspects of HTTP
1521 content and transactions are handled, and on which sites (or even parts
1522 thereof). There are three such files included with Privoxy, with slightly
1523 different purposes. default.action sets the default policies. standard.action
1524 is used by Privoxy and the web based editor to set pre-defined values (and
1525 normally should not be edited). Local exceptions are best done in user.action.
1526 The content of these can all be viewed and edited from http://
1527 config.privoxy.org/show-status.
1529 Anything you want can blocked, including ads, banners, or just some obnoxious
1530 URL that you would rather not see is done here. Cookies can be accepted or
1531 rejected, or accepted only during the current browser session (i.e. not written
1532 to disk), content can be modified, JavaScripts tamed, user-tracking fooled, and
1533 much more. See below for a complete list of available actions.
1535 An actions file typically has sections. Near the top, "aliases" are optionally
1536 defined (discussed below), then the default set of rules which will apply
1537 universally to all sites and pages. And then below that, exceptions to the
1538 defined universal policies.
1540 -------------------------------------------------------------------------------
1542 5.4.1. Finding the Right Mix
1544 Note that some actions like cookie suppression or script disabling may render
1545 some sites unusable, which rely on these techniques to work properly. Finding
1546 the right mix of actions is not easy and certainly a matter of personal taste.
1547 In general, it can be said that the more "aggressive" your default settings (in
1548 the top section of the actions file) are, the more exceptions for "trusted"
1549 sites you will have to make later. If, for example, you want to kill popup
1550 windows per default, you'll have to make exceptions from that rule for sites
1551 that you regularly use and that require popups for actually useful content,
1552 like maybe your bank, favorite shop, or newspaper.
1554 We have tried to provide you with reasonable rules to start from in the
1555 distribution actions files. But there is no general rule of thumb on these
1556 things. There just are too many variables, and sites are constantly changing.
1557 Sooner or later you will want to change the rules (and read this chapter again
1560 -------------------------------------------------------------------------------
1564 The easiest way to edit the "actions" files is with a browser by using our
1565 browser-based editor, which can be reached from http://config.privoxy.org/
1568 If you prefer plain text editing to GUIs, you can of course also directly edit
1569 the the actions files.
1571 -------------------------------------------------------------------------------
1573 5.4.3. How Actions are Applied to URLs
1575 Actions files are divided into sections. There are special sections, like the "
1576 alias" sections which will be discussed later. For now let's concentrate on
1577 regular sections: They have a heading line (often split up to multiple lines
1578 for readability) which consist of a list of actions, separated by whitespace
1579 and enclosed in curly braces. Below that, there is a list of URL patterns, each
1582 To determine which actions apply to a request, the URL of the request is
1583 compared to all patterns in this file. Every time it matches, the list of
1584 applicable actions for the URL is incrementally updated, using the heading of
1585 the section in which the pattern is located. If multiple matches for the same
1586 URL set the same action differently, the last match wins. If not, the effects
1587 are aggregated (e.g. a URL might match both the "+handle-as-image" and "+block"
1590 You can trace this process by visiting http://config.privoxy.org/show-url-info.
1592 More detail on this is provided in the Appendix, Anatomy of an Action.
1594 -------------------------------------------------------------------------------
1598 Generally, a pattern has the form <domain>/<path>, where both the <domain> and
1599 <path> are optional. (This is why the pattern / matches all URLs).
1603 is a domain-only pattern and will match any request to www.example.com,
1604 regardless of which document on that server is requested.
1608 means exactly the same. For domain-only patterns, the trailing / may be
1611 www.example.com/index.html
1613 matches only the single document /index.html on www.example.com.
1617 matches the document /index.html, regardless of the domain, i.e. on any web
1622 matches nothing, since it would be interpreted as a domain name and there
1623 is no top-level domain called .html.
1625 -------------------------------------------------------------------------------
1627 5.4.4.1. The Domain Pattern
1629 The matching of the domain part offers some flexible options: if the domain
1630 starts or ends with a dot, it becomes unanchored at that end. For example:
1634 matches any domain that ENDS in .example.com
1638 matches any domain that STARTS with www.
1642 matches any domain that CONTAINS .example. (Correctly speaking: It matches
1643 any FQDN that contains example as a domain.)
1645 Additionally, there are wild-cards that you can use in the domain names
1646 themselves. They work pretty similar to shell wild-cards: "*" stands for zero
1647 or more arbitrary characters, "?" stands for any single character, you can
1648 define character classes in square brackets and all of that can be freely
1653 matches "adserver.example.com", "ads.example.com", etc but not
1658 matches all of the above, and then some.
1662 matches www.ipix.com, pictures.epix.com, a.b.c.d.e.upix.com etc.
1664 www[1-9a-ez].example.c*
1666 matches www1.example.com, www4.example.cc, wwwd.example.cy,
1667 wwwz.example.com etc., but not wwww.example.com.
1669 -------------------------------------------------------------------------------
1671 5.4.4.2. The Path Pattern
1673 Privoxy uses Perl compatible regular expressions (through the PCRE library) for
1676 There is an Appendix with a brief quick-start into regular expressions, and
1677 full (very technical) documentation on PCRE regex syntax is available on-line
1678 at http://www.pcre.org/man.txt. You might also find the Perl man page on
1679 regular expressions (man perlre) useful, which is available on-line at http://
1680 www.perldoc.com/perl5.6/pod/perlre.html.
1682 Note that the path pattern is automatically left-anchored at the "/", i.e. it
1683 matches as if it would start with a "^" (regular expression speak for the
1684 beginning of a line).
1686 Please also note that matching in the path is case INSENSITIVE by default, but
1687 you can switch to case sensitive at any point in the pattern by using the "(?
1688 -i)" switch: www.example.com/(?-i)PaTtErN.* will match only documents whose
1689 path starts with PaTtErN in exactly this capitalization.
1691 -------------------------------------------------------------------------------
1695 All actions are disabled by default, until they are explicitly enabled
1696 somewhere in an actions file. Actions are turned on if preceded with a "+", and
1697 turned off if preceded with a "-". So a "+action" means "do that action", e.g.
1698 "+block" means please "block the following URL patterns".
1700 Actions are invoked by enclosing the action name in curly braces (e.g.
1701 {+some_action}), followed by a list of URLs (or patterns that match URLs) to
1702 which the action applies. There are three classes of actions:
1704 * Boolean, i.e the action can only be "on" or "off". Examples:
1706 {+name} # enable this action
1707 {-name} # disable this action
1710 * Parameterized, e.g. "+/-hide-user-agent{ Mozilla 1.0 }", where some value
1711 is required in order to enable this type of action. Examples:
1713 {+name{param}} # enable action and set parameter to "param"
1714 {-name} # disable action ("parameter") can be omitted
1717 * Multi-value, e.g. "{+/-add-header{Name: value}}" or "{+/-send-wafer{name=
1718 value}}"), where some value needs to be defined in addition to simply
1719 enabling the action. Examples:
1721 {+name{param=value}} # enable action and set "param" to "value"
1722 {-name{param=value}} # remove the parameter "param" completely
1723 {-name} # disable this action totally and remove param too
1726 If nothing is specified in any actions file, no "actions" are taken. So in this
1727 case Privoxy would just be a normal, non-blocking, non-anonymizing proxy. You
1728 must specifically enable the privacy and blocking features you need (although
1729 the provided default actions files will give a good starting point).
1731 Later defined actions always over-ride earlier ones. So exceptions to any rules
1732 you make, should come in the latter part of the file. For multi-valued actions,
1733 the actions are applied in the order they are specified. Actions files are
1734 processed in the order they are defined in config (the default installation has
1735 three actions files). It also quite possible for any given URL pattern to match
1736 more than one action!
1738 The list of valid Privoxy "actions" are:
1740 -------------------------------------------------------------------------------
1742 5.4.5.1. +add-header{Name: value}
1750 Send a user defined HTTP header to the web server.
1754 Any value is possible. Validity of the defined HTTP headers is not checked.
1758 {+add-header{X-User-Tracking: sucks}}
1764 This action may be specified multiple times, in order to define multiple
1765 headers. This is rarely needed for the typical user. If you don't know what
1766 "HTTP headers" are, you definitely don't need to worry about this one.
1768 -------------------------------------------------------------------------------
1778 Used to block a URL from reaching your browser. The URL may be anything,
1779 but is typically used to block ads or other obnoxious content.
1788 .banners.example.com
1794 If a URL matches one of the blocked patterns, Privoxy will intercept the
1795 URL and display its special "BLOCKED" page instead. If there is sufficient
1796 space, a large red banner will appear with a friendly message about why the
1797 page was blocked, and a way to go there anyway. If there is insufficient
1798 space a smaller blocked page will appear without the red banner. Click here
1799 to view the default blocked HTML page (Privoxy must be running for this to
1802 A very important exception is if the URL matches both "+block" and
1803 "+handle-as-image", then it will be handled by "+set-image-blocker" (see
1804 below). It is important to understand this process, in order to understand
1805 how Privoxy is able to deal with ads and other objectionable content.
1807 The "+filter" action can also perform some of the same functionality as
1808 "+block", but by virtue of very different programming techniques, and is
1809 most often used for different reasons.
1811 -------------------------------------------------------------------------------
1813 5.4.5.3. +deanimate-gifs
1821 To stop those annoying, distracting animated GIF images.
1829 {+deanimate-gifs{last}}
1835 De-animate all animated GIF images, i.e. reduce them to their last frame.
1836 This will also shrink the images considerably (in bytes, not pixels!). If
1837 the option "first" is given, the first frame of the animation is used as
1838 the replacement. If "last" is given, the last frame of the animation is
1839 used instead, which probably makes more sense for most banner animations,
1840 but also has the risk of not showing the entire last frame (if it is only a
1841 delta to an earlier frame).
1843 -------------------------------------------------------------------------------
1845 5.4.5.4. +downgrade-http-version
1853 "+downgrade-http-version" will downgrade HTTP/1.1 client requests to HTTP/
1854 1.0 and downgrade the responses as well.
1862 {+downgrade-http-version}
1868 Use this action for servers that use HTTP/1.1 protocol features that
1869 Privoxy doesn't handle well yet. HTTP/1.1 is only partially implemented.
1870 Default is not to downgrade requests. This is an infrequently needed
1871 action, and is used to help with rare problem sites only.
1873 -------------------------------------------------------------------------------
1875 5.4.5.5. +fast-redirects
1883 The "+fast-redirects" action enables interception of "redirect" requests
1884 from one server to another, which are used to track users.Privoxy can cut
1885 off all but the last valid URL in a redirect request and send a local
1886 redirect back to your browser without contacting the intermediate site(s).
1900 Many sites, like yahoo.com, don't just link to other sites. Instead, they
1901 will link to some script on their own server, giving the destination as a
1902 parameter, which will then redirect you to the final target. URLs resulting
1903 from this scheme typically look like: http://some.place/some_script?http://
1906 Sometimes, there are even multiple consecutive redirects encoded in the
1907 URL. These redirections via scripts make your web browsing more traceable,
1908 since the server from which you follow such a link can see where you go to.
1909 Apart from that, valuable bandwidth and time is wasted, while your browser
1910 ask the server for one redirect after the other. Plus, it feeds the
1913 This is a normally "on" feature, and often requires exceptions for sites
1914 that are sensitive to defeating this mechanism.
1916 -------------------------------------------------------------------------------
1926 Apply page filtering as defined by named sections of the default.filter
1927 file to the specified site(s). "Filtering" can be any modification of the
1928 raw page content, including re-writing or deletion of content.
1932 "+filter" must include the name of one of the section identifiers from
1933 default.filter (or whatever filterfile is specified in config).
1935 Example usage (from the current default.filter):
1937 +filter{html-annoyances}: Get rid of particularly annoying HTML abuse.
1939 +filter{js-annoyances}: Get rid of particularly annoying JavaScript abuse
1941 +filter{content-cookies}: Kill cookies that come in the HTML or JS content
1943 +filter{popups}: Kill all popups in JS and HTML
1945 +filter{frameset-borders}: Give frames a border and make them resizable
1947 +filter{webbugs}: Squish WebBugs (1x1 invisible GIFs used for user
1950 +filter{refresh-tags}: Kill automatic refresh tags (for dial-on-demand
1953 +filter{fun}: Text replacements for subversive browsing fun!
1955 +filter{nimda}: Remove Nimda (virus) code.
1957 +filter{banners-by-size}: Kill banners by size (very efficient!)
1959 +filter{shockwave-flash}: Kill embedded Shockwave Flash objects
1961 +filter{crude-parental}: Kill all web pages that contain the words "sex" or
1966 This is potentially a very powerful feature! And requires a knowledge of
1967 regular expressions if you want to "roll your own". Filtering operates on a
1968 line by line basis throughout the entire page.
1970 Filtering requires buffering the page content, which may appear to slow
1971 down page rendering since nothing is displayed until all content has passed
1972 the filters. (It does not really take longer, but seems that way since the
1973 page is not incrementally displayed.) This effect will be more noticeable
1974 on slower connections.
1976 Filtering can achieve some of the effects as the "+block" action, i.e. it
1977 can be used to block ads and banners. In the overall scheme of things,
1978 filtering is one of the first things "Privoxy" does with a web page. So
1979 other most other actions are applied to the already "filtered" page.
1981 -------------------------------------------------------------------------------
1983 5.4.5.7. +hide-forwarded-for-headers
1991 Block any existing X-Forwarded-for HTTP header, and do not add a new one.
1999 {+hide-forwarded-for-headers}
2005 It is fairly safe to leave this on. It does not seem to break many sites.
2007 -------------------------------------------------------------------------------
2009 5.4.5.8. +hide-from-header
2017 To block the browser from sending your email address in a "From:" header.
2021 Keyword: "block", or any user defined value.
2025 {+hide-from-header{block}}
2031 The keyword "block" will completely remove the header (not to be confused
2032 with the "+block" action). Alternately, you can specify any value you
2033 prefer to send to the web server.
2035 -------------------------------------------------------------------------------
2037 5.4.5.9. +hide-referer
2045 Don't send the "Referer:" (sic) HTTP header to the web site. Or,
2046 alternately send a forged header instead.
2050 Prevent the header from being sent with the keyword, "block". Or, "forge" a
2051 URL to one from the same server as the request. Or, set to user defined
2052 value of your choice.
2056 {+hide-referer{forge}}
2062 "forge" is the preferred option here, since some servers will not send
2063 images back otherwise.
2065 "+hide-referrer" is an alternate spelling of "+hide-referer". It has the
2066 exact same parameters, and can be freely mixed with, "+hide-referer".
2067 ("referrer" is the correct English spelling, however the HTTP specification
2068 has a bug - it requires it to be spelled as "referer".)
2070 -------------------------------------------------------------------------------
2072 5.4.5.10. +hide-user-agent
2080 To change the "User-Agent:" header so web servers can't tell your browser
2081 type. Who's business is it anyway?
2085 Any user defined string.
2089 {+hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}}
2095 Warning! This breaks many web sites that depend on this in order to
2096 determine how the target browser will respond to various requests. Use with
2099 -------------------------------------------------------------------------------
2101 5.4.5.11. +handle-as-image
2109 To define what Privoxy should treat automatically as an image, and is an
2110 important ingredient of how ads are handled.
2119 /.*\.(gif|jpg|jpeg|png|bmp|ico)
2124 This only has meaning if the URL (or pattern) also is "+block"ed, in which
2125 case a user definable image can be sent rather than a HTML page. This is
2126 integral to the whole concept of ad blocking: the URL must match both a
2127 "+block" rule, and "+handle-as-image". (See "+set-image-blocker" below for
2128 control over what will actually be displayed by the browser.)
2130 There is little reason to change the default definition for this action.
2132 -------------------------------------------------------------------------------
2134 5.4.5.12. +set-image-blocker
2142 Decide what to do with URLs that end up tagged with both "+block" and
2143 "+handle-as-image", e.g an advertisement.
2147 There are four available options: "-set-image-blocker" will send a HTML
2148 "blocked" page, usually resulting in a "broken image" icon.
2149 "+set-image-blocker{blank}" will send a 1x1 transparent GIF image.
2150 "+set-image-blocker{pattern}" will send a checkerboard type pattern (the
2151 default). And finally, "+set-image-blocker{http://xyz.com}" will send a
2152 HTTP temporary redirect to the specified image. This has the advantage of
2153 the icon being being cached by the browser, which will speed up the
2158 {+set-image-blocker{blank}}
2164 If you want invisible ads, they need to meet criteria as matching both
2165 images and blocked actions. And then, "image-blocker" should be set to
2166 "blank" for invisibility. Note you cannot treat HTML pages as images in
2167 most cases. For instance, frames require an HTML page to display. So a
2168 frame that is an ad, typically cannot be treated as an image. Forcing an
2169 "image" in this situation just will not work reliably.
2171 -------------------------------------------------------------------------------
2173 5.4.5.13. +limit-connect
2181 By default, Privoxy only allows HTTP CONNECT requests to port 443 (the
2182 standard, secure HTTPS port). Use "+limit-connect" to disable this
2183 altogether, or to allow more ports.
2187 Any valid port number, or port number range.
2191 +limit-connect{443} #
2192 This is the default and need not be specified.
2193 +limit-connect{80,443} # Ports 80 and 443 are OK.
2194 +limit-connect{-3, 7, 20-100, 500-} #
2195 Port less than 3, 7, 20 to 100 and above 500 are OK.
2200 The CONNECT methods exists in HTTP to allow access to secure websites
2201 (https:// URLs) through proxies. It works very simply: the proxy connects
2202 to the server on the specified port, and then short-circuits its
2203 connections to the client and to the remote proxy. This can be a big
2204 security hole, since CONNECT-enabled proxies can be abused as TCP relays
2207 If you want to allow CONNECT for more ports than this, or want to forbid
2208 CONNECT altogether, you can specify a comma separated list of ports and
2209 port ranges (the latter using dashes, with the minimum defaulting to 0 and
2212 If you don't know what any of this means, there probably is no reason to
2215 -------------------------------------------------------------------------------
2217 5.4.5.14. +prevent-compression
2225 Prevent the specified websites from compressing HTTP data.
2233 {+prevent-compression}
2239 Some websites do this, which can be a problem for Privoxy, since "+filter",
2240 "+kill-popups" and "+gif-deanimate" will not work on compressed data. This
2241 will slow down connections to those websites, though. Default typically is
2242 to turn "prevent-compression" on.
2244 -------------------------------------------------------------------------------
2246 5.4.5.15. +session-cookies-only
2254 Allow cookies for the current browser session only.
2260 Example usage (disabling):
2262 {-session-cookies-only}
2268 If websites set cookies, "+session-cookies-only" will make sure they are
2269 erased when you exit and restart your web browser. This makes profiling
2270 cookies useless, but won't break sites which require cookies so that you
2271 can log in for transactions. This is generally turned on for all sites, and
2272 is the recommended setting.
2274 "+prevent-*-cookies" actions should be turned off as well (see below), for
2275 "+session-cookies-only" to work. Or, else no cookies will get through at
2276 all. For, "persistent" cookies that survive across browser sessions, see
2279 -------------------------------------------------------------------------------
2281 5.4.5.16. +prevent-reading-cookies
2289 Explicitly prevent the web server from reading any cookies on your system.
2297 {+prevent-reading-cookies}
2303 Often used in conjunction with "+prevent-setting-cookies" to disable
2304 cookies completely. Note that "+session-cookies-only" requires these to
2305 both be disabled (or else it never gets any cookies to cache).
2307 For "persistent" cookies to work (i.e. they survive across browser sessions
2308 and reboots), all three cookie settings should be "off" for the specified
2311 -------------------------------------------------------------------------------
2313 5.4.5.17. +prevent-setting-cookies
2321 Explicitly block the web server from storing cookies on your system.
2329 {+prevent-setting-cookies}
2335 Often used in conjunction with "+prevent-reading-cookies" to disable
2336 cookies completely (see above).
2338 -------------------------------------------------------------------------------
2340 5.4.5.18. +kill-popups
2348 Stop those annoying JavaScript pop-up windows!
2362 "+kill-popups" uses a built in filter to disable pop-ups that use the
2363 window.open() function, etc. This is one of the first actions processed by
2364 Privoxy as it contacts the remote web server. This action is not always
2365 100% reliable, and is supplemented by "+filter{popups}".
2367 -------------------------------------------------------------------------------
2369 5.4.5.19. +send-vanilla-wafer
2377 Sends a cookie for every site stating that you do not accept any copyright
2378 on cookies sent to you, and asking them not to track you.
2386 {+send-vanilla-wafer}
2392 This action only applies if you are using a jarfile for saving cookies. Of
2393 course, this is a (relatively) unique header and could conceivably be used
2396 -------------------------------------------------------------------------------
2398 5.4.5.20. +send-wafer
2406 This allows you to send an arbitrary, user definable cookie.
2410 User specified cookie name and corresponding value.
2414 {+send-wafer{name=value}}
2420 This can be specified multiple times in order to add as many cookies as you
2423 -------------------------------------------------------------------------------
2425 5.4.5.21. Actions Examples
2427 Note that the meaning of any of the above examples is reversed by preceding the
2428 action with a "-", in place of the "+". Also, that some actions are turned on
2429 in the default section of the actions file, and require little to no additional
2430 configuration. These are just "on". But, other actions that are turned on the
2431 default section do typically require exceptions to be listed in the lower
2432 sections of actions file. E.g. by default no URLs are "blocked" (i.e. in the
2433 default definitions of default.action). We need exceptions to this in order to
2438 Turn off cookies by default, then allow a few through for specified sites
2439 (showing an excerpt from the "default" section of an actions file ONLY):
2442 # Allow cookies to and from the server, but
2443 # for this browser session ONLY
2445 # other actions normally listed here...
2446 -prevent-setting-cookies \
2447 -prevent-reading-cookies \
2448 +session-cookies-only \
2452 # Exceptions to the above, sites that benefit from persistent cookies
2453 # that are saved from one browser session to the next.
2454 { -session-cookies-only }
2463 Now turn off "fast redirects", and then we allow two exceptions:
2465 # Turn them off (excerpt only)!
2467 # other actions normally listed here...
2472 # Reverse it for these two sites, which don't work right without it.
2474 www.ukc.ac.uk/cgi-bin/wac\.cgi\?
2478 Turn on page filtering according to rules in the defined sections of
2479 default.filter, and make one exception for Sourceforge:
2481 # Run everything through the filter file, using only certain
2482 # specified sections:
2484 # other actions normally listed here...
2485 +filter{html-annoyances} +filter{js-annoyances} +filter{kill-popups}\
2486 +filter{webbugs} +filter{nimda} +filter{banners-by-size}
2490 # Then disable filtering of code from all sourceforge domains!
2495 Now some URLs that we want "blocked" (normally generates the "blocked" banner).
2496 Typically, the "block" action is off by default in the upper section of an
2497 actions file, then enabled against certain URLs and patterns in the lower part
2498 of the file. Many of these use regular expressions that will expand to match
2507 /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
2508 /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
2510 /.*/(ng)?adclient\.cgi
2511 /.*/(plain|live|rotate)[-_.]?ads?/
2516 Note that many of these actions have the potential to cause a page to
2517 misbehave, possibly even not to display at all. There are many ways a site
2518 designer may choose to design his site, and what HTTP header content, and other
2519 criteria, he may depend on. There is no way to have hard and fast rules for all
2520 sites. See the Appendix for a brief example on troubleshooting actions.
2522 -------------------------------------------------------------------------------
2526 Custom "actions", known to Privoxy as "aliases", can be defined by combining
2527 other "actions". These can in turn be invoked just like the built-in "actions".
2528 Currently, an alias can contain any character except space, tab, "=", "{" or "}
2529 ". But please use only "a"- "z", "0"-"9", "+", and "-". Alias names are not
2530 case sensitive, and must be defined before other actions in the actions file!
2531 And there can only be one set of "aliases" defined per file. Each actions file
2532 may have its own aliases, but they are only visible within that file.
2534 Now let's define a few aliases:
2536 # Useful custom aliases we can use later. These must come first!
2538 +prevent-cookies = +prevent-setting-cookies +prevent-reading-cookies
2539 -prevent-cookies = -prevent-setting-cookies -prevent-reading-cookies
2541 -block -prevent-cookies -filter -fast-redirects -hide-referer -kill-popups
2542 shop = -prevent-cookies -filter -fast-redirects
2543 +imageblock = +block +handle-as-image
2545 # Aliases defined from other aliases, for people who don't like to type
2547 c0 = +prevent-cookies
2548 c1 = -prevent-cookies
2549 #... etc. Customize to your heart's content.
2552 Some examples using our "shop" and "fragile" aliases from above. These would
2553 appear in the lower sections of an actions file as exceptions to the default
2554 actions (as defined in the upper section):
2556 # These sites are very complex and require
2557 # minimal interference.
2559 .office.microsoft.com
2560 .windowsupdate.microsoft.com
2563 # Shopping sites - but we still want to block ads.
2566 .worldpay.com # for quietpc.com
2569 # These shops require pop-ups also
2575 The "shop" and "fragile" aliases are often used for "problem" sites that
2576 require most actions to be disabled in order to function properly.
2578 -------------------------------------------------------------------------------
2580 5.5. The Filter File
2582 Any web page can be dynamically modified with the filter file. This
2583 modification can be removal, or re-writing, of any web page content, including
2584 tags and non-visible content. The default filter file is default.filter,
2585 located in the config directory.
2587 This is potentially a very powerful feature, and requires knowledge of both
2588 "regular expression" and HTML in order create custom filters. But, there are a
2589 number of useful filters included with Privoxy for many common situations.
2591 The included example file is divided into sections. Each section begins with
2592 the FILTER keyword, followed by the identifier for that section, e.g. "FILTER:
2593 webbugs". Each section performs a similar type of filtering, such as
2596 This file uses regular expressions to alter or remove any string in the target
2597 page. The expressions can only operate on one line at a time. Some examples
2598 from the included default default.filter:
2600 Stop web pages from displaying annoying messages in the status bar by deleting
2603 FILTER: html-annoyances
2605 # New browser windows should be resizeable and have a location and status
2608 s/resizable="?(no|0)"?/resizable=1/ig s/noresize/yesresize/ig
2609 s/location="?(no|0)"?/location=1/ig s/status="?(no|0)"?/status=1/ig
2610 s/scrolling="?(no|0|Auto)"?/scrolling=1/ig
2611 s/menubar="?(no|0)"?/menubar=1/ig
2613 # The <BLINK> tag was a crime!
2615 s*<blink>|</blink>**ig
2619 #s/framespacing="?(no|0)"?//ig
2620 #s/margin(height|width)=[0-9]*//gi
2623 Just for kicks, replace any occurrence of "Microsoft" with "MicroSuck", and
2624 have a little fun with topical buzzwords:
2628 s/microsoft(?!.com)/MicroSuck/ig
2632 s/industry-leading|cutting-edge|award-winning/<font color=red><b>BINGO!</b></
2636 Kill those pesky little web-bugs:
2638 # webbugs: Squish WebBugs (1x1 invisible GIFs used for user tracking)
2641 s/<img\s+[^>]*?(width|height)\s*=\s*['"]?1\D[^>]*?(width|height)\s*=\s*['"]?1
2642 (\D[^>]*?)?>/<!-- Squished WebBug -->/sig
2645 -------------------------------------------------------------------------------
2649 When Privoxy displays one of its internal pages, such as a 404 Not Found error
2650 page, it uses the appropriate template. On Linux, BSD, and Unix, these are
2651 located in /etc/privoxy/templates by default. These may be customized, if
2652 desired. cgi-style.css is used to control the HTML attributes (fonts, etc).
2654 The default "Blocked" banner page with the bright red top banner, is called
2655 just "blocked". This may be customized or replaced with something else if
2658 -------------------------------------------------------------------------------
2660 6. Contacting the Developers, Bug Reporting and Feature Requests
2662 We value your feedback. However, to provide you with the best support, please
2665 * Use the Sourceforge Support Forum to get help:
2667 http://sourceforge.net/tracker/?group_id=11118&atid=211118
2670 * Submit bugs only through our Sourceforge Bug Forum:
2672 http://sourceforge.net/tracker/?group_id=11118&atid=111118.
2675 Make sure that the bug has not already been submitted. Please try to verify
2676 that it is a Privoxy bug, and not a browser or site bug first. If you are
2677 using your own custom configuration, please try the stock configs to see if
2678 the problem is a configuration related bug. And if not using the latest
2679 development snapshot, please try the latest one. Or even better, CVS
2680 sources. Please be sure to include the Privoxy/Junkbuster version,
2681 platform, browser, any pertinent log data, any other relevant details
2682 (please be specific) and, if possible, some way to reproduce the bug.
2684 * Submit feature requests only through our Sourceforge feature request forum:
2686 http://sourceforge.net/tracker/?atid=361118&group_id=11118&func=browse.
2689 * You can also send feedback on websites that Privoxy has problems with. Please bookmark
2690 the following link: "Privoxy - Submit Filter Feedback"
2691 . Once you surf to a page with problems, use the
2692 bookmark to send us feedback. We will look into the issue as soon as possible.
2695 * For any other issues, feel free to use the mailing lists:
2697 http://sourceforge.net/mail/?group_id=11118.
2700 Anyone interested in actively participating in development and related
2701 discussions can also join the appropriate mailing list. Archives are
2704 -------------------------------------------------------------------------------
2706 6.1. Submitting Ads and "Action" Problems
2708 Ads and banners that are not stopped by Privoxy can be submitted to the
2709 developers by accessing a special page and filling out the brief, required
2710 form. Conversely, you can also report pages, images, etc. that Privoxy is
2711 blocking, but should not. The form itself does require Internet access.
2713 To do this, point your browser to Privoxy at http://config.privoxy.org/
2714 (shortcut: http://p.p/), and then select Actions file feedback system, near the
2715 bottom of the page. Paste in the URL that is the cause of the unwanted
2716 behavior, and follow the prompts. The developers will try to incorporate a fix
2717 for the problem you reported into future versions.
2719 New, improved default.action files will occasionally be made available based on
2720 your feedback. These will be announced on the ijbswa-announce list.
2722 -------------------------------------------------------------------------------
2724 7. Copyright and History
2728 Privoxy is free software; you can redistribute it and/or modify it under the
2729 terms of the GNU General Public License as published by the Free Software
2730 Foundation; either version 2 of the License, or (at your option) any later
2733 This program is distributed in the hope that it will be useful, but WITHOUT ANY
2734 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
2735 PARTICULAR PURPOSE. See the GNU General Public License for more details, which
2736 is available from the Free Software Foundation, Inc, 59 Temple Place - Suite
2737 330, Boston, MA 02111-1307, USA.
2739 You should have received a copy of the GNU General Public License along with
2740 this program; if not, write to the Free Software Foundation, Inc., 59 Temple
2741 Place, Suite 330, Boston, MA 02111-1307 USA.
2743 -------------------------------------------------------------------------------
2747 Privoxy is evolved, and derived from, the Internet Junkbuster, with many
2748 improvments and enhancements over the original.
2750 Junkbuster was originally written by Anonymous Coders and Junkbusters
2751 Corporation, and was released as free open-source software under the GNU GPL.
2752 Stefan Waldherr made many improvements, and started the SourceForge project
2753 Privoxy to rekindle development. There are now several active developers
2754 contributing. The last stable release of Junkbuster was v2.0.2, which has now
2757 -------------------------------------------------------------------------------
2761 Other references and sites of interest to Privoxy users:
2763 http://www.privoxy.org/, The Privoxy Home page.
2765 http://sourceforge.net/projects/ijbswa, the Project Page for Privoxy on
2768 http://p.p/, access Privoxy from your browser. Alternately, http://
2769 config.privoxy.org may work in some situations where the first does not.
2771 http://p.p/, and select "actions file feedback system" to submit "misses" to
2774 http://www.junkbusters.com/ht/en/cookies.html
2776 http://www.waldherr.org/junkbuster/
2778 http://privacy.net/analyze/
2780 http://www.squid-cache.org/
2784 -------------------------------------------------------------------------------
2788 9.1. Regular Expressions
2790 Privoxy can use "regular expressions" in various config files. Assuming support
2791 for "pcre" (Perl Compatible Regular Expressions) is compiled in, which is the
2792 default. Such configuration directives do not require regular expressions, but
2793 they can be used to increase flexibility by matching a pattern with wild-cards
2796 If you are reading this, you probably don't understand what "regular
2797 expressions" are, or what they can do. So this will be a very brief
2798 introduction only. A full explanation would require a book ;-)
2800 "Regular expressions" is a way of matching one character expression against
2801 another to see if it matches or not. One of the "expressions" is a literal
2802 string of readable characters (letter, numbers, etc), and the other is a
2803 complex string of literal characters combined with wild-cards, and other
2804 special characters, called meta-characters. The "meta-characters" have special
2805 meanings and are used to build the complex pattern to be matched against. Perl
2806 Compatible Regular Expressions is an enhanced form of the regular expression
2807 language with backward compatibility.
2809 To make a simple analogy, we do something similar when we use wild-card
2810 characters when listing files with the dir command in DOS. *.* matches all
2811 filenames. The "special" character here is the asterisk which matches any and
2812 all characters. We can be more specific and use ? to match just individual
2813 characters. So "dir file?.text" would match "file1.txt", "file2.txt", etc. We
2814 are pattern matching, using a similar technique to "regular expressions"!
2816 Regular expressions do essentially the same thing, but are much, much more
2817 powerful. There are many more "special characters" and ways of building complex
2818 patterns however. Let's look at a few of the common ones, and then some
2821 . - Matches any single character, e.g. "a", "A", "4", ":", or "@".
2823 ? - The preceding character or expression is matched ZERO or ONE times. Either/
2826 + - The preceding character or expression is matched ONE or MORE times.
2828 * - The preceding character or expression is matched ZERO or MORE times.
2830 \ - The "escape" character denotes that the following character should be taken
2831 literally. This is used where one of the special characters (e.g. ".") needs to
2832 be taken literally and not as a special meta-character. Example: "example
2833 \.com", makes sure the period is recognized only as a period (and not expanded
2834 to its meta-character meaning of any single character).
2836 [] - Characters enclosed in brackets will be matched if any of the enclosed
2837 characters are encountered. For instance, "[0-9]" matches any numeric digit
2838 (zero through nine). As an example, we can combine this with "+" to match any
2839 digit one of more times: "[0-9]+".
2841 () - parentheses are used to group a sub-expression, or multiple
2844 | - The "bar" character works like an "or" conditional statement. A match is
2845 successful if the sub-expression on either side of "|" matches. As an example:
2846 "/(this|that) example/" uses grouping and the bar character and would match
2847 either "this example" or "that example", and nothing else.
2849 s/string1/string2/g - This is used to rewrite strings of text. "string1" is
2850 replaced by "string2" in this example. There must of course be a match on
2853 These are just some of the ones you are likely to use when matching URLs with
2854 Privoxy, and is a long way from a definitive list. This is enough to get us
2855 started with a few simple examples which may be more illuminating:
2857 /.*/banners/.* - A simple example that uses the common combination of "." and "
2858 *" to denote any character, zero or more times. In other words, any string at
2859 all. So we start with a literal forward slash, then our regular expression
2860 pattern (".*") another literal forward slash, the string "banners", another
2861 forward slash, and lastly another ".*". We are building a directory path here.
2862 This will match any file with the path that has a directory named "banners" in
2863 it. The ".*" matches any characters, and this could conceivably be more forward
2864 slashes, so it might expand into a much longer looking path. For example, this
2865 could match: "/eye/hate/spammers/banners/annoy_me_please.gif", or just "/
2866 banners/annoying.html", or almost an infinite number of other possible
2867 combinations, just so it has "banners" in the path somewhere.
2869 A now something a little more complex:
2871 /.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward
2872 slashes again ("/"), so we are building another expression that is a file path
2873 statement. We have another ".*", so we are matching against any conceivable
2874 sub-path, just so it matches our expression. The only true literal that must
2875 match our pattern is adv, together with the forward slashes. What comes after
2876 the "adv" string is the interesting part.
2878 Remember the "?" means the preceding expression (either a literal character or
2879 anything grouped with "(...)" in this case) can exist or not, since this means
2880 either zero or one match. So "((er)?ts?|ertis(ing|ements?))" is optional, as
2881 are the individual sub-expressions: "(er)", "(ing|ements?)", and the "s". The "
2882 |" means "or". We have two of those. For instance, "(ing|ements?)", can expand
2883 to match either "ing" OR "ements?". What is being done here, is an attempt at
2884 matching as many variations of "advertisement", and similar, as possible. So
2885 this would expand to match just "adv", or "advert", or "adverts", or
2886 "advertising", or "advertisement", or "advertisements". You get the idea. But
2887 it would not match "advertizements" (with a "z"). We could fix that by changing
2888 our regular expression to: "/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/", which
2889 would then match either spelling.
2891 /.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward
2892 slashes. Anything in the square brackets "[]" can be matched. This is using
2893 "0-9" as a shorthand expression to mean any digit one through nine. It is the
2894 same as saying "0123456789". So any digit matches. The "+" means one or more of
2895 the preceding expression must be included. The preceding expression here is
2896 what is in the square brackets -- in this case, any digit one through nine.
2897 Then, at the end, we have a grouping: "(gif|jpe?g)". This includes a "|", so
2898 this needs to match the expression on either side of that bar character also. A
2899 simple "gif" on one side, and the other side will in turn match either "jpeg"
2900 or "jpg", since the "?" means the letter "e" is optional and can be matched
2901 once or not at all. So we are building an expression here to match image GIF or
2902 JPEG type image file. It must include the literal string "advert", then one or
2903 more digits, and a "." (which is now a literal, and not a special character,
2904 since it is escaped with "\"), and lastly either "gif", or "jpeg", or "jpg".
2905 Some possible matches would include: "//advert1.jpg", "/nasty/ads/
2906 advert1234.gif", "/banners/from/hell/advert99.jpg". It would not match
2907 "advert1.gif" (no leading slash), or "/adverts232.jpg" (the expression does not
2908 include an "s"), or "/advert1.jsp" ("jsp" is not in the expression anywhere).
2910 s/microsoft(?!.com)/MicroSuck/i - This is a substitution. "MicroSuck" will
2911 replace any occurrence of "microsoft". The "i" at the end of the expression
2912 means ignore case. The "(?!.com)" means the match should fail if "microsoft" is
2913 followed by ".com". In other words, this acts like a "NOT" modifier. In case
2914 this is a hyperlink, we don't want to break it ;-).
2916 We are barely scratching the surface of regular expressions here so that you
2917 can understand the default Privoxy configuration files, and maybe use this
2918 knowledge to customize your own installation. There is much, much more that can
2919 be done with regular expressions. Now that you know enough to get started, you
2920 can learn more on your own :/
2922 More reading on Perl Compatible Regular expressions: http://www.perldoc.com/
2923 perl5.6/pod/perlre.html
2925 -------------------------------------------------------------------------------
2927 9.2. Privoxy's Internal Pages
2929 Since Privoxy proxies each requested web page, it is easy for Privoxy to trap
2930 certain special URLs. In this way, we can talk directly to Privoxy, and see how
2931 it is configured, see how our rules are being applied, change these rules and
2932 other configuration options, and even turn Privoxy's filtering off, all with a
2935 The URLs listed below are the special ones that allow direct access to Privoxy.
2936 Of course, Privoxy must be running to access these. If not, you will get a
2937 friendly error message. Internet access is not necessary either.
2939 * Privoxy main page:
2941 http://config.privoxy.org/
2943 Alternately, this may be reached at http://p.p/, but this variation may not
2944 work as reliably as the above in some configurations.
2946 * Show information about the current configuration, including viewing and
2947 editing of actions files:
2949 http://config.privoxy.org/show-status
2951 * Show the source code version numbers:
2953 http://config.privoxy.org/show-version
2955 * Show the browser's request headers:
2957 http://config.privoxy.org/show-request
2959 * Show which actions apply to a URL and why:
2961 http://config.privoxy.org/show-url-info
2963 * Toggle Privoxy on or off. In this case, "Privoxy" continues to run, but
2964 only as a pass-through proxy, with no actions taking place:
2966 http://config.privoxy.org/toggle
2968 Short cuts. Turn off, then on:
2970 http://config.privoxy.org/toggle?set=disable
2972 http://config.privoxy.org/toggle?set=enable
2974 These may be bookmarked for quick reference. See next.
2976 -------------------------------------------------------------------------------
2980 Below are some "bookmarklets" to allow you to easily access a "mini" version of
2981 some of Privoxy's special pages. They are designed for MS Internet Explorer,
2982 but should work equally well in Netscape, Mozilla, and other browsers which
2983 support JavaScript. They are designed to run directly from your bookmarks - not
2984 by clicking the links below (although that should work for testing).
2986 To save them, right-click the link and choose "Add to Favorites" (IE) or "Add
2987 Bookmark" (Netscape). You will get a warning that the bookmark "may not be
2988 safe" - just click OK. Then you can run the Bookmarklet directly from your
2989 favorites/bookmarks. For even faster access, you can put them on the "Links"
2990 bar (IE) or the "Personal Toolbar" (Netscape), and run them with a single
2997 * Toggle Privoxy (Toggles between enabled and disabled)
2999 * View Privoxy Status
3001 * Actions file feedback system
3003 Credit: The site which gave me the general idea for these bookmarklets is
3004 www.bookmarklets.com. They have more information about bookmarklets.
3006 -------------------------------------------------------------------------------
3008 9.3. Chain of Events
3010 Let's take a quick look at the basic sequence of events when a web page is
3011 requested by your browser and Privoxy is on duty:
3013 * First, your web browser requests a web page. The browser knows to send the
3014 request to Privoxy, which will in turn, relay the request to the remote web
3015 server after passing the following tests:
3017 * Privoxy traps any request for its own internal CGI pages (e.g http://p.p/)
3018 and sends the CGI page back to the browser.
3020 * Next, Privoxy checks to see if the URL matches any "+block" patterns. If
3021 so, the URL is then blocked, and the remote web server will not be
3022 contacted. "+handle-as-image" is then checked and if it does not match, an
3023 HTML "BLOCKED" page is sent back. Otherwise, if it does match, an image is
3024 returned. The type of image depends on the setting of "+set-image-blocker"
3025 (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
3027 * Untrusted URLs are blocked. If URLs are being added to the trust file, then
3030 * If the URL pattern matches the "+fast-redirects" action, it is then
3031 processed. Unwanted parts of the requested URL are stripped.
3033 * Now the rest of the client browser's request headers are processed. If any
3034 of these match any of the relevant actions (e.g. "+hide-user-agent", etc.),
3035 headers are suppressed or forged as determined by these actions and their
3038 * Now the web server starts sending its response back (i.e. typically a web
3039 page and related data).
3041 * First, the server headers are read and processed to determine, among other
3042 things, the MIME type (document type) and encoding. The headers are then
3043 filtered as deterimed by the "+prevent-setting-cookies",
3044 "+session-cookies-only", and "+downgrade-http-version" actions.
3046 * If the "+kill-popups" action applies, and it is an HTML or JavaScript
3047 document, the popup-code in the response is filtered on-the-fly as it is
3050 * If a "+filter" or "+deanimate-gifs" action applies (and the document type
3051 fits the action), the rest of the page is read into memory (up to a
3052 configurable limit). Then the filter rules (from default.filter) are
3053 processed against the buffered content. Filters are applied in the order
3054 they are specified in the default.filter file. Animated GIFs, if present,
3055 are reduced to either the first or last frame, depending on the action
3056 setting.The entire page, which is now filtered, is then sent by Privoxy
3057 back to your browser.
3059 If neither "+filter" or "+deanimate-gifs" matches, then Privoxy passes the
3060 raw data through to the client browser as it becomes available.
3062 * As the browser receives the now (probably filtered) page content, it reads
3063 and then requests any URLs that may be embedded within the page source,
3064 e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
3065 frames), sounds, etc. For each of these objects, the browser issues a new
3066 request. And each such request is in turn processed as above. Note that a
3067 complex web page may have many such embedded URLs.
3069 -------------------------------------------------------------------------------
3071 9.4. Anatomy of an Action
3073 The way Privoxy applies "actions" and "filters" to any given URL can be
3074 complex, and not always so easy to understand what is happening. And sometimes
3075 we need to be able to see just what Privoxy is doing. Especially, if something
3076 Privoxy is doing is causing us a problem inadvertently. It can be a little
3077 daunting to look at the actions and filters files themselves, since they tend
3078 to be filled with "regular expressions" whose consequences are not always so
3081 One quick test to see if Privoxy is causing a problem or not, is to disable it
3082 temporarily. This should be the first troubleshooting step. See the
3083 Bookmarklets section on a quick and easy way to do this (be sure to flush
3086 Privoxy also provides the http://config.privoxy.org/show-url-info page that can
3087 show us very specifically how actions are being applied to any given URL. This
3088 is a big help for troubleshooting.
3090 First, enter one URL (or partial URL) at the prompt, and then Privoxy will tell
3091 us how the current configuration will handle it. This will not help with
3092 filtering effects (i.e. the "+filter" action) from the default.filter file
3093 since this is handled very differently and not so easy to trap! It also will
3094 not tell you about any other URLs that may be embedded within the URL you are
3095 testing. For instance, images such as ads are expressed as URLs within the raw
3096 page source of HTML pages. So you will only get info for the actual URL that is
3097 pasted into the prompt area -- not any sub-URLs. If you want to know about
3098 embedded URLs like ads, you will have to dig those out of the HTML source. Use
3099 your browser's "View Page Source" option for this. Or right click on the ad,
3102 Let's try an example, google.com, and look at it one section at a time:
3104 Matches for http://google.com:
3106 --- File standard ---
3107 (no matches in this file)
3109 --- File default ---
3111 { -add-header -block +deanimate-gifs{last} -downgrade-http-version +fast-redirects
3112 -filter{popups} -filter{fun} -filter{shockwave-flash} -filter{crude-parental}
3113 +filter{html-annoyances} +filter{js-annoyances} +filter{content-cookies}
3114 +filter{webbugs} +filter{refresh-tags} +filter{nimda} +filter{banners-by-size}
3115 +hide-forwarded-for-headers +hide-from-header{block} +hide-referer{forge}
3116 -hide-user-agent -handle-as-image +set-image-blocker{pattern} -limit-connect
3117 +prevent-compression +session-cookies-only -prevent-reading-cookies
3118 -prevent-setting-cookies -kill-popups -send-vanilla-wafer -send-wafer }
3121 { -session-cookies-only }
3128 (no matches in this file)
3130 This tells us how we have defined our "actions", and which ones match for our
3131 example, "google.com". The first listing is any matches for the standard.action
3132 file. No hits at all here on "standard". Then next is "default", or our
3133 default.action file. The large, multi-line listing, is how the actions are set
3134 to match for all URLs, i.e. our default settings. If you look at your "actions"
3135 file, this would be the section just below the "aliases" section near the top.
3136 This will apply to all URLs as signified by the single forward slash at the end
3137 of the listing -- "/".
3139 But we can define additional actions that would be exceptions to these general
3140 rules, and then list specific URLs (or patterns) that these exceptions would
3141 apply to. Last match wins. Just below this then are two explicit matches for
3142 ".google.com". The first is negating our previous cookie setting, which was for
3143 "+session-cookies-only" (i.e. not persistent). So we will allow persistent
3144 cookies for google. The second turns off any "+fast-redirects" action, allowing
3145 this to take place unmolested. Note that there is a leading dot here --
3146 ".google.com". This will match any hosts and sub-domains, in the google.com
3147 domain also, such as "www.google.com". So, apparently, we have these two
3148 actions defined somewhere in the lower part of our default.action file, and
3149 "google.com" is referenced somewhere in these latter sections.
3151 Then, for our user.action file, we again have no hits.
3153 And finally we pull it all together in the bottom section and summarize how
3154 Privoxy is applying all its "actions" to "google.com":
3157 -add-header -block +deanimate-gifs{last} -downgrade-http-version -fast-redirects
3158 -filter{popups} -filter{fun} -filter{shockwave-flash} -filter{crude-parental}
3159 +filter{html-annoyances} +filter{js-annoyances} +filter{content-cookies}
3160 +filter{webbugs} +filter{refresh-tags} +filter{nimda} +filter{banners-by-size}
3161 +hide-forwarded-for-headers +hide-from-header{block} +hide-referer{forge}
3162 -hide-user-agent -handle-as-image +set-image-blocker{pattern} -limit-connect
3163 +prevent-compression -session-cookies-only -prevent-reading-cookies
3164 -prevent-setting-cookies -kill-popups -send-vanilla-wafer -send-wafer
3168 Notice the only difference here to the previous listing, is to "fast-redirects"
3169 and "session-cookies-only".
3171 Now another example, "ad.doubleclick.net":
3173 { +block +handle-as-image }
3176 { +block +handle-as-image }
3179 { +block +handle-as-image }
3184 We'll just show the interesting part here, the explicit matches. It is matched
3185 three different times. Each as an "+block +handle-as-image", which is the
3186 expanded form of one of our aliases that had been defined as: "+imageblock". (
3187 "Aliases" are defined in the first section of the actions file and typically
3188 used to combine more than one action.)
3190 Any one of these would have done the trick and blocked this as an unwanted
3191 image. This is unnecessarily redundant since the last case effectively would
3192 also cover the first. No point in taking chances with these guys though ;-)
3193 Note that if you want an ad or obnoxious URL to be invisible, it should be
3194 defined as "ad.doubleclick.net" is done here -- as both a "+block" and an
3195 "+handle-as-image". The custom alias "+imageblock" just simplifies the process
3196 and make it more readable.
3198 One last example. Let's try "http://www.rhapsodyk.net/adsl/HOWTO/". This one is
3199 giving us problems. We are getting a blank page. Hmmm...
3201 Matches for http://www.rhapsodyk.net/adsl/HOWTO/:
3203 { -add-header -block +deanimate-gifs -downgrade-http-version +fast-redirects
3204 +filter{html-annoyances} +filter{js-annoyances} +filter{kill-popups}
3205 +filter{webbugs} +filter{nimda} +filter{banners-by-size} +filter{hal}
3206 +filter{fun} +hide-forwarded-for-headers +hide-from-header{block}
3207 +hide-referer{forge} -hide-user-agent -handle-as-image +set-image-blocker{blank}
3208 +prevent-compression +session-cookies-only -prevent-setting-cookies
3209 -prevent-reading-cookies +kill-popups -send-vanilla-wafer -send-wafer }
3212 { +block +handle-as-image }
3217 Ooops, the "/adsl/" is matching "/ads"! But we did not want this at all! Now we
3218 see why we get the blank page. We could now add a new action below this that
3219 explicitly does not block ("{-block}") paths with "adsl". There are various
3220 ways to handle such exceptions. Example:
3227 Now the page displays ;-) Be sure to flush your browser's caches when making
3228 such changes. Or, try using Shift+Reload.
3230 But now what about a situation where we get no explicit matches like we did
3233 { +block +handle-as-image }
3238 That actually was very telling and pointed us quickly to where the problem was.
3239 If you don't get this kind of match, then it means one of the default rules in
3240 the first section is causing the problem. This would require some guesswork,
3241 and maybe a little trial and error to isolate the offending rule. One likely
3242 cause would be one of the "{+filter}" actions. Try adding the URL for the site
3243 to one of aliases that turn off "+filter":
3247 .worldpay.com # for quietpc.com
3254 "{shop}" is an "alias" that expands to "{ -filter -session-cookies-only }". Or
3255 you could do your own exception to negate filtering:
3262 This would probably be most appropriately put in user.action, for local site
3265 "{fragile}" is an alias that disables most actions. This can be used as a last
3266 resort for problem sites. Remember to flush caches! If this still does not
3267 work, you will have to go through the remaining actions one by one to find
3268 which one(s) is causing the problem.
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