1 <!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook V3.1//EN" [
2 <!entity % dummy "IGNORE">
3 <!entity supported SYSTEM "supported.sgml">
4 <!entity newfeatures SYSTEM "newfeatures.sgml">
5 <!entity p-intro SYSTEM "privoxy.sgml">
6 <!entity seealso SYSTEM "seealso.sgml">
7 <!entity buildsource SYSTEM "buildsource.sgml">
8 <!entity contacting SYSTEM "contacting.sgml">
9 <!entity history SYSTEM "history.sgml">
10 <!entity copyright SYSTEM "copyright.sgml">
11 <!entity license SYSTEM "license.sgml">
12 <!entity p-authors SYSTEM "p-authors.sgml">
13 <!entity config SYSTEM "p-config.sgml">
14 <!entity p-version "3.0.20">
15 <!entity p-status "beta">
16 <!entity % p-authors-formal "INCLUDE"> <!-- include additional text, etc -->
17 <!entity % p-not-stable "INCLUDE">
18 <!entity % p-stable "IGNORE">
19 <!entity % p-text "IGNORE"> <!-- define we are not a text only doc -->
20 <!entity % p-doc "INCLUDE"> <!-- and we are a formal doc -->
21 <!entity % p-readme "IGNORE">
22 <!entity % user-man "IGNORE">
23 <!entity % config-file "IGNORE">
24 <!entity % p-supp-userman "IGNORE"> <!-- Omit some from supported.sgml -->
25 <!entity my-copy "©"> <!-- kludge for docbook2man -->
26 <!entity % draft "IGNORE"> <!-- WIP stuff -->
27 <!entity % seealso-extra "INCLUDE"> <!-- extra stuff from seealso.sgml -->
28 <!entity my-app "<application>Privoxy</application>">
31 File : $Source: /cvsroot/ijbswa/current/doc/source/user-manual.sgml,v $
34 This file belongs into
35 ijbswa.sourceforge.net:/home/groups/i/ij/ijbswa/htdocs/
37 $Id: user-manual.sgml,v 2.161 2013/01/12 12:21:38 fabiankeil Exp $
39 Copyright (C) 2001-2013 Privoxy Developers http://www.privoxy.org/
42 ========================================================================
43 NOTE: Please read developer-manual/documentation.html before touching
44 anything in this, or other Privoxy documentation.
45 ========================================================================
52 <title>Privoxy &p-version; User Manual</title>
56 <!-- Completely the wrong markup, but very little is allowed -->
57 <!-- in this part of an article. FIXME -->
58 <link linkend="copyright">Copyright</link> &my-copy; 2001-2013 by
59 <ulink url="http://www.privoxy.org/">Privoxy Developers</ulink>
63 <pubdate>$Id: user-manual.sgml,v 2.161 2013/01/12 12:21:38 fabiankeil Exp $</pubdate>
67 Note: the following should generate a separate page, and a live link to it,
68 all nicely done. But it doesn't for some mysterious reason. Please leave
69 commented unless it can be fixed proper. For the time being, the
70 copyright/license declarations will be in their own sgml.
83 This is here to keep vim syntax file from breaking :/
84 If I knew enough to fix it, I would.
85 PLEASE DO NOT REMOVE! HB: hal@foobox.net
91 The <citetitle>Privoxy User Manual</citetitle> gives users information on how to
92 install, configure and use <ulink
93 url="http://www.privoxy.org/">Privoxy</ulink>.
96 <!-- Include privoxy.sgml boilerplate: -->
98 <!-- end privoxy.sgml -->
101 You can find the latest version of the <citetitle>Privoxy User Manual</citetitle> at <ulink
102 url="http://www.privoxy.org/user-manual/">http://www.privoxy.org/user-manual/</ulink>.
103 Please see the <link linkend="contact">Contact section</link> on how to
104 contact the developers.
108 <!-- Feel free to send a note to the developers at <email>ijbswa-developers@lists.sourceforge.net</email>. -->
114 <!-- ~~~~~ New section ~~~~~ -->
115 <sect1 label="1" id="introduction"><title>Introduction</title>
117 This documentation is included with the current &p-status; version of
118 <application>Privoxy</application>, v.&p-version;<![%p-not-stable;[,
119 and is mostly complete at this point. The most up to date reference for the
120 time being is still the comments in the source files and in the individual
121 configuration files. Development of a new version is currently nearing
122 completion, and includes significant changes and enhancements over
126 <!-- include only in non-stable versions -->
129 Since this is a &p-status; version, not all new features are well tested. This
130 documentation may be slightly out of sync as a result (especially with
131 CVS sources). And there <emphasis>may be</emphasis> bugs, though hopefully
136 <!-- ~~~~~ New section ~~~~~ -->
137 <sect2 id="features"><title>Features</title>
139 In addition to the core
140 features of ad blocking and
141 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookie</ulink> management,
142 <application>Privoxy</application> provides many supplemental
143 features<![%p-not-stable;[, some of them currently under development]]>,
144 that give the end-user more control, more privacy and more freedom:
146 <!-- Include newfeatures.sgml boilerplate here: -->
148 <!-- end boilerplate -->
153 <!-- ~ End section ~ -->
156 <!-- ~~~~~ New section ~~~~~ -->
157 <sect1 id="installation"><title>Installation</title>
160 <application>Privoxy</application> is available both in convenient pre-compiled
161 packages for a wide range of operating systems, and as raw source code.
162 For most users, we recommend using the packages, which can be downloaded from our
163 <ulink url="http://sourceforge.net/projects/ijbswa/">Privoxy Project
169 On some platforms, the installer may remove previously installed versions, if
170 found. (See below for your platform). In any case <emphasis>be sure to backup
171 your old configuration if it is valuable to you.</emphasis> See the <link
172 linkend="upgradersnote">note to upgraders</link> section below.
175 <!-- ~~~~~ New section ~~~~~ -->
176 <sect2 id="installation-packages"><title>Binary Packages</title>
178 How to install the binary packages depends on your operating system:
181 <!-- XXX: The installation sections should be sorted -->
183 <!-- ~~~~~ New section ~~~~~ -->
184 <sect3 id="installation-deb"><title>Debian and Ubuntu</title>
186 DEBs can be installed with <literal>apt-get install privoxy</literal>,
187 and will use <filename>/etc/privoxy</filename> for the location of
192 <!-- ~~~~~ New section ~~~~~ -->
193 <sect3 id="installation-pack-win"><title>Windows</title>
196 Just double-click the installer, which will guide you through
197 the installation process. You will find the configuration files
198 in the same directory as you installed <application>Privoxy</application> in.
201 Version 3.0.5 beta introduced full <application>Windows</application> service
202 functionality. On Windows only, the <application>Privoxy</application>
203 program has two new command line arguments to install and uninstall
204 <application>Privoxy</application> as a <emphasis>service</emphasis>.
208 <term>Arguments:</term>
211 <replaceable class="parameter">--install</replaceable>[:<replaceable class="parameter">service_name</replaceable>]
214 <replaceable class="parameter">--uninstall</replaceable>[:<replaceable class="parameter">service_name</replaceable>]
220 After invoking <application>Privoxy</application> with
221 <command>--install</command>, you will need to bring up the
222 <application>Windows</application> service console to assign the user you
223 want <application>Privoxy</application> to run under, and whether or not you
224 want it to run whenever the system starts. You can start the
225 <application>Windows</application> services console with the following
226 command: <command>services.msc</command>. If you do not take the manual step
227 of modifying <application>Privoxy's</application> service settings, it will
228 not start. Note too that you will need to give Privoxy a user account that
229 actually exists, or it will not be permitted to
230 write to its log and configuration files.
235 <!-- ~~~~~ New section ~~~~~ -->
236 <sect3 id="installation-os2"><title>OS/2</title>
239 First, make sure that no previous installations of
240 <application>Junkbuster</application> and / or
241 <application>Privoxy</application> are left on your
242 system. Check that no <application>Junkbuster</application>
243 or <application>Privoxy</application> objects are in
249 Then, just double-click the WarpIN self-installing archive, which will
250 guide you through the installation process. A shadow of the
251 <application>Privoxy</application> executable will be placed in your
252 startup folder so it will start automatically whenever OS/2 starts.
256 The directory you choose to install <application>Privoxy</application>
257 into will contain all of the configuration files.
261 <!-- ~~~~~ New section ~~~~~ -->
262 <sect3 id="installation-mac"><title>Mac OS X</title>
264 Installation instructions for the OS X platform depend upon whether
265 you downloaded a ready-built installation package (.pkg or .mpkg) or have
266 downloaded the source code.
269 <sect3 renderas="sect4" id="OS-X-install-from-package">
270 <title>Installation from ready-built package</title>
272 The downloaded file will either be a .pkg (for OS X 10.5 upwards) or a bzipped
273 .mpkg file (for OS X 10.4). The former can be double-clicked as is and the
274 installation will start; double-clicking the latter will unzip the .mpkg file
275 which can then be double-clicked to commence the installation.
278 The privoxy service will automatically start after a successful installation
279 (and thereafter every time your computer starts up) however you will need to
280 configure your web browser(s) to use it. To do so, configure them to use a
281 proxy for HTTP and HTTPS at the address 127.0.0.1:8118.
284 To prevent the privoxy service from automatically starting when your computer
285 starts up, remove or rename the file <literal>/Library/LaunchDaemons/org.ijbswa.privoxy.plist</literal>
286 (on OS X 10.5 and higher) or the folder named
287 <literal>/Library/StartupItems/Privoxy</literal> (on OS X 10.4 'Tiger').
290 To manually start or stop the privoxy service, use the scripts startPrivoxy.sh
291 and stopPrivoxy.sh supplied in /Applications/Privoxy. They must be run from an
292 administrator account, using sudo.
295 To uninstall, run /Applications/Privoxy/uninstall.command as sudo from an
296 administrator account.
299 <sect3 renderas="sect4" id="OS-X-install-from-source">
300 <title>Installation from source</title>
302 To build and install the Privoxy source code on OS X you will need to obtain
303 the macsetup module from the Privoxy Sourceforge CVS repository (refer to
304 Sourceforge help for details of how to set up a CVS client to have read-only
305 access to the repository). This module contains scripts that leverage the usual
306 open-source tools (available as part of Apple's free of charge Xcode
307 distribution or via the usual open-source software package managers for OS X
308 (MacPorts, Homebrew, Fink etc.) to build and then install the privoxy binary
309 and associated files. The macsetup module's README file contains complete
310 instructions for its use.
313 The privoxy service will automatically start after a successful installation
314 (and thereafter every time your computer starts up) however you will need to
315 configure your web browser(s) to use it. To do so, configure them to use a
316 proxy for HTTP and HTTPS at the address 127.0.0.1:8118.
319 To prevent the privoxy service from automatically starting when your computer
320 starts up, remove or rename the file <literal>/Library/LaunchDaemons/org.ijbswa.privoxy.plist</literal>
321 (on OS X 10.5 and higher) or the folder named
322 <literal>/Library/StartupItems/Privoxy</literal> (on OS X 10.4 'Tiger').
325 To manually start or stop the privoxy service, use the Privoxy Utility
326 for Mac OS X (also part of the macsetup module). This application can start
327 and stop the privoxy service and display its log and configuration files.
330 To uninstall, run the macsetup module's uninstall.sh as sudo from an
331 administrator account.
335 <!-- ~~~~~ New section ~~~~~ -->
336 <sect3 id="installation-tbz"><title>FreeBSD</title>
339 Privoxy is part of FreeBSD's Ports Collection, you can build and install
340 it with <literal>cd /usr/ports/www/privoxy; make install clean</literal>.
343 If you don't use the ports, you can fetch and install
344 the package with <literal>pkg_add -r privoxy</literal>.
347 The port skeleton and the package can also be downloaded from the
348 <ulink url="https://sourceforge.net/project/showfiles.php?group_id=11118">File Release
349 Page</ulink>, but there's no reason to use them unless you're interested in the
350 beta releases which are only available there.
356 <!-- ~~~~~ New section ~~~~~ -->
357 <sect2 id="installation-source"><title>Building from Source</title>
360 The most convenient way to obtain the <application>Privoxy</application> sources
361 is to download the source tarball from our
362 <ulink url="http://sourceforge.net/project/showfiles.php?group_id=11118&package_id=10571">project download
367 If you like to live on the bleeding edge and are not afraid of using
368 possibly unstable development versions, you can check out the up-to-the-minute
369 version directly from <ulink url="http://sourceforge.net/cvs/?group_id=11118">the
370 CVS repository</ulink>.
372 deprecated...out of business.
373 or simply download <ulink
374 url="http://cvs.sourceforge.net/cvstarballs/ijbswa-cvsroot.tar.bz2">the nightly CVS
379 <!-- include buildsource.sgml boilerplate: -->
381 <!-- end boilerplate -->
384 <!-- ~~~~~ New section ~~~~~ -->
385 <sect2 id="installation-keepupdated"><title>Keeping your Installation Up-to-Date</title>
388 If you wish to receive an email notification whenever we release updates of
389 <application>Privoxy</application> or the actions file, <ulink
390 url="http://lists.sourceforge.net/lists/listinfo/ijbswa-announce/">subscribe
391 to our announce mailing list</ulink>, ijbswa-announce@lists.sourceforge.net.
395 In order not to lose your personal changes and adjustments when updating
396 to the latest <literal>default.action</literal> file we <emphasis>strongly
397 recommend</emphasis> that you use <literal>user.action</literal> and
398 <literal>user.filter</literal> for your local
399 customizations of <application>Privoxy</application>. See the <link
400 linkend="actions-file">Chapter on actions files</link> for details.
408 <!-- ~ End section ~ -->
410 <!-- ~~~~~ New section ~~~~~ -->
411 <sect1 id="whatsnew">
412 <title>What's New in this Release</title>
414 <application>Privoxy 3.0.20</application> is a beta release.
415 The changes since 3.0.19 stable are:
426 Client sockets are now properly shutdown and drained before being
427 closed. This fixes page truncation issues with clients that aggressively
428 pipeline data on platforms that otherwise discard already written data.
429 The issue mainly affected Opera users and was initially reported
430 by Kevin in #3464439, szotsaki provided additional information to track
436 Fix latency calculation for shared connections (disabled by default).
437 It was broken since their introduction in 2009. The calculated latency
438 for most connections would be 0 in which case the timeout detection
439 failed to account for the real latency.
444 Reject URLs with invalid port. Previously they were parsed incorrectly and
445 characters between the port number and the first slash were silently
446 dropped as shown by curl test 187.
451 The default-server-timeout and socket-timeout directives accept 0 as
457 Fix a race condition on Windows that could cause Privoxy to become
458 unresponsive after toggling it on or off through the taskbar icon.
459 Reported by Tim H. in #3525694.
464 Fix the compilation on Windows when configured without IPv6 support.
469 Fix an assertion that could cause debug builds to abort() in case of
470 socks5 connection failures with "debug 2" enabled.
475 Fix an assertion that could cause debug builds to abort() if a filter
476 contained nul bytes in the replacement text.
484 General improvements:
488 Significantly improved keep-alive support for both client and server
494 New debug log level 65536 which logs all actions that were applied to
500 New directive client-header-order to forward client headers in a
501 different order than the one in which they arrived.
506 New directive tolerate-pipelining to allow client-side pipelining.
507 If enabled (3.0.20 beta enables it by default), Privoxy will keep
508 pipelined client requests around to deal with them once the current
509 request has been served.
514 New --config-test option to let Privoxy exit after checking whether or not
515 the configuration seems valid. The limitations noted in TODO #22 and #23
516 still apply. Based on a patch by Ramkumar Chinchani.
521 New limit-cookie-lifetime{} action to let cookies expire before the end
522 of the session. Suggested by Rick Sykes in #1049575.
527 Increase the hard-coded maximum number of actions and filter files from
528 10 to 30 (each). It doesn't significantly affect Privoxy's memory usage
529 and recompiling wasn't an option for all Privoxy users that reached the
535 Add support for chunk-encoded client request bodies. Previously
536 chunk-encoded request bodies weren't guaranteed to be forwarded correctly,
537 so this can also be considered a bug fix although chunk-encoded request
538 bodies aren't commonly used in the real world.
543 Add support for Tor's optimistic-data SOCKS extension, which can reduce the
544 latency for requests on newly created connections. Currently only the
545 headers are sent optimistically and only if the client request has already
546 been read completely which rules out requests with large bodies.
551 After preventing the client from pipelining, don't signal keep-alive
552 intentions. When looking at the response headers alone, it previously
553 wasn't obvious from the client's perspective that no additional responses
559 Stop considering client sockets tainted after receving a request with body.
560 It hasn't been necessary for a while now and unnecessarily causes test
561 failures when using curl's test suite.
566 Allow HTTP/1.0 clients to signal interest in keep-alive through the
567 Proxy-Connection header. While such client are rare in the real world, it
568 doesn't hurt and couple of curl tests rely on it.
573 Only remove duplicated Content-Type headers when filters are enabled.
574 If they are not it doesn't cause ill effects and the user might not want it.
575 Downgrade the removal message to LOG_LEVEL_HEADER to clarify that it's not
576 an error in Privoxy and is unlikely to cause any problems in general.
577 Anonymously reported in #3599335.
582 Set the socket option SO_LINGER for the client socket.
587 Move several variable declarations to the beginning of their code block.
588 It's required when compiling with gcc 2.95 which is still used on some
589 platforms. Initial patch submitted by Simon South in #3564815.
594 Optionally try to sanity-check strptime() results before trusting them.
595 Broken strptime() implementations have caused problems in the past and
596 the most recent offender seems to be FreeBSD's libc (standards/173421).
601 When filtering is enabled, let Range headers pass if the range starts at
602 the beginning. This should work around (or at least reduce ) the video
603 playback issues with various Apple clients as reported by Duc in #3426305.
608 Do not confuse a client hanging up with a connection time out. If a client
609 closes its side of the connection without sending a request line, do not
610 send the CLIENT_CONNECTION_TIMEOUT_RESPONSE, but report the condition
616 Allow closing curly braces as part of action values as long as they are
622 On Windows, the logfile is now written before showing the GUI error
623 message which blocks until the user acknowledges it.
624 Reported by Adriaan in #3593603.
629 Remove an unreasonable parameter limit in the CGI interface. The new
630 parameter limit depends on the memory available and is currently unlikely
631 to be reachable, due to other limits in both Privoxy and common clients.
632 Reported by Andrew on ijbswa-users@.
637 Decrease the chances of parse failures after requests with unsupported
638 methods were sent to the CGI interface.
646 Action file improvements:
650 Remove the comment that indicated that updated default.action versions
651 are released on their own.
656 Block 'optimize.indieclick.com/' and 'optimized-by.rubiconproject.com/'
661 Unblock 'adjamblog.wordpress.com/' and 'adjamblog.files.wordpress.com/'.
662 Reported by Ryan Farmer in #3496116.
667 Unblock '/.*Bugtracker'. Reported by pwhk in #3522341.
672 Add test URLs for '.freebsd.org' and '.watson.org'.
677 Unblock '.urbandictionary.com/popular'.
687 Block 'farm.plista.com/widgetdata.php'.
692 Block 'rotation.linuxnewmedia.com/'.
697 Block 'reklamy.sfd.pl/'. Reported by kacperdominik in #3399948.
702 Block 'g.adspeed.net/'.
707 Unblock 'websupport.wdc.com/'. Reported by Adam Piggot in #3577851.
712 Block '/openx/www/delivery/'.
717 Disable fast-redirects for '.googleapis.com/'.
722 Block 'imp.double.net/'. Reported by David Bo in #3070411.
727 Block 'gm-link.com/' whis is used for email tracking.
728 Reported by David Bo in #1812733.
733 Verify that requests to "bwp." are blocked. URL taken from #1736879
734 submitted by Francois Marier.
739 Block '/.*bannerid='. Reported by Adam Piggott in #2975779.
744 Block 'cltomedia.info/delivery/' and '.adexprt.com/'.
745 Anonymously reported in #2965254.
750 Block 'de17a.com/'. Reported by David Bo in #3061472.
755 Block 'oskar.tradera.com/'. Reported by David Bo in #3060596.
760 Block '/scripts/webtrends\.js'. Reported by johnd16 in #3002729.
765 Block requests for 'pool.*.adhese.com/'. Reported by johnd16 in #3002716.
770 Update path pattern for Coremetrics and add tests.
771 Pattern and URLs submitted by Adam Piggott #3168443.
776 Enable +fast-redirects{check-decoded-url} for 'tr.anp.se/'.
777 Reported by David Bo in #3268832.
782 Unblock '.conrad.se/newsletter/banners/'. Reported by David Bo in #3413824.
787 Block '.tynt.com/'. Reported by Dan Stahlke in #3421767.
792 Unblock '.bbci.co.uk/radio/'. Reported by Adam Piggott in #3569603.
797 Block requests to 'service.maxymiser.net/'.
798 Reported by johnd16 in #3118401 (with a previous URL).
803 Disable fast-redirects for Google's "let's pretend your computer is
809 Unblock '/.*download' to resolve actionsfile feedback #3498129.
810 Submitted by Steven Kolins (soundcloud.com not working).
815 Unblock '.wlxrs.com/' which is required by hotmail.com.
816 Fixes #3413827 submitted by David Bo.
821 Add two unblock patterns for popup radio and TV players.
822 Submitted by Adam Piggott in #3596089.
830 Filter file improvements & bug fixes:
834 Add a referer tagger.
839 Reduce the likelihood that the google filter messes up HTML-generating
840 JavaScript. Reported by Zeno Kugy in #3520260.
848 Documentation improvements:
852 Revised all OS X sections due to new packaging module (OSXPackageBuilder).
857 Update the list of supported operating systems to clarify that all Windows
858 versions after 95 are expected to work and note that the platform-specific
859 code for AmigaOS and QNX currently isn't maintained.
864 Update 'Signals' section, the only explicitly handled signals are SIGINT,
870 Add Haiku to the list of operating systems on which Privoxy is known to
876 Add DragonFly to the list of BSDs on which Privoxy is known to run.
881 Removed references to redhat-specific documentation set since it no longer
887 Removed references to building PDFs since we no longer do so.
892 Multiple listen-address directives are supported since 3.0.18, correct the
893 documentation to say so.
898 Remove bogus section about long and short being preferable to int.
903 Corrected some Internet JunkBuster references to Privoxy.
908 Removed references to www.junkbusters.com since it is no longer
909 maintained. Reported by Angelina Matson.
914 Various grammar and spelling corrections
919 Add a client-header-tagger{} example for disabling filtering for range
925 Correct a URL in the "Privoxy with Tor" FAQ.
930 Spell 'refresh-tags' correctly. Reported by Don in #3571927.
935 Sort manpage options alphabetically.
940 Remove an incorrect sentence in the toggle section. The toggle state
941 doesn't affect whether or not the Windows version uses the tray icon.
942 Reported by Zeno Kugy in #3596395.
947 Add new contributors since 3.0.19.
955 Log message improvements:
959 When stopping to watch a client socket due to pipelining, additionally log
965 Log the client socket and its condition before closing it. This makes it
966 more obvious that the socket actually gets closed and should help when
967 diagnosing problems like #3464439.
972 In case of SOCKS5 failures, do not explicitly log the server's response.
973 It hasn't helped so far and the response can already be logged by enabling
974 "debug 32768" anyway. This reverts v1.81 and the follow-up bug fix v1.84.
979 Relocate the connection-accepted message from listen_loop() to serve().
980 This way it's printed by the thread that is actually serving the
981 connection which is nice when grepping for thread ids in log files.
993 Remove compatibility layer for versions prior to 3.0 since it has been
994 obsolete for more than 10 years now.
999 Remove the ijb_isupper() and ijb_tolower() macros from parsers.c since
1000 they aren't used in this file.
1005 Removed the 'Functions declared include:' comment sections since they tend
1006 to be incomplete, incorrect and out of date and the benefit seems
1012 Various comment grammar and comprehensibility improvements.
1017 Remove a pointless fflush() call in chat(). Flushing all streams pretty
1018 much all the time for no obvious reason is ridiculous.
1023 Relocate ijb_isupper()'s definition to project.h and get the ijb_tolower()
1024 definition from there, too.
1029 Relocate ijb_isdigit()'s definition to project.h.
1034 Rename ijb_foo macros to privoxy_foo.
1039 Add malloc_or_die() which will allow to simplify code paths where malloc()
1040 failures don't need to be handled gracefully.
1045 Add strdup_or_die() which will allow to simplify code paths where strdup()
1046 failures don't need to be handled gracefully.
1051 Replace strdup() calls with strdup_or_die() calls where it's safe and
1052 simplifies the code.
1057 Fix white-space around parentheses.
1062 Add missing white-space behind if's and the following parentheses.
1067 Unwrap a memcpy() call in resolve_hostname_to_ip().
1072 Declare pcrs_get_delimiter()'s delimiters[] static const.
1077 Various optimisations to remove dead code and merge inefficient code
1078 structures for improved clarity, performance or code compactness.
1083 Various data type corrections.
1088 Change visibility of several code segments when compiling without
1089 FEATURE_CONNECTION_KEEP_ALIVE enabled for clarity.
1094 In pcrs_get_delimiter(), do not use delimiters ouside the ASCII range.
1095 Fixes a clang complaint.
1100 Fix an error message in get_last_url() nobody is supposed to see.
1101 Reported by Matthew Fischer in #3507301.
1106 Fix a typo in the no-zlib-support complaint. Patch submitted by Matthew
1107 Fischer in #3507304.
1112 Shorten ssplit()'s prototype by removing the last two arguments. We always
1113 want to skip empty fields and ignore leading delimiters, so having
1114 parameters for this only complicates the API.
1119 Use an enum for the type of the action value.
1124 Rename action_name's member takes_value to value_type as it isn't used as
1130 Turn family mismatches in match_sockaddr() into fatal errors.
1135 Let enlist_unique_header() verify that the caller didn't pass a header
1136 containing either \r or \n.
1141 Change the hashes used in load_config() to unsigned int. That's what
1142 hash_string() actually returns and using a potentiallly larger type
1148 Use privoxy_tolower() instead of vanilla tolower() with manual casting of
1154 Catch ssplit() failures in parse_cgi_parameters().
1162 Privoxy-Regression-Test:
1166 Add an 'Overwrite condition' directive to skip any matching tests before
1167 it. As it has a global scope, using it is more convenient than clowning
1168 around with the Ignore directive.
1173 Log to STDOUT instead of STDERR.
1178 Include the Privoxy version in the output.
1183 Various grammar and spelling corrections in documentation and code.
1188 Additional tests for range requests with filtering enabled.
1193 Tests with mostly invalid range request.
1198 Add a couple of hide-if-modified-since{} tests with different date formats.
1203 Cleaned up the format of the regression-tests.action file to match the
1204 format of default.action.
1209 Remove the "Copyright" line from print_version(). When using --help, every
1210 line of screen space matters and thus shouldn't be wasted on things the
1211 user doesn't care about.
1223 Improve the --statistics performance by skipping sanity checks for input
1224 that shouldn't affect the results anyway. Add a --strict-checks option
1225 that enables some of the checks again, just in case anybody cares.
1230 The distribution of client requests per connection is included in
1231 the --statistic output.
1236 The --accept-unknown-messages option has been removed and the behavior
1242 Accept and (mostly) highlight new log messages introduced with
1255 Bump generated Firefox version to 17.
1263 GNUmakefile improvements:
1267 The dok-tidy target no longer taints documents with a tidy-mark
1272 Change RA_MODE from 0664 to 0644. Suggested by Markus Dittrich in
1278 Remove tidy's clean flag as it changes the scope of attributes.
1279 Link-specific colors end up being applied to all text. Reported by Adam
1280 Piggott in #3569551.
1285 Leave it up to the user whether or not smart tags are inserted.
1290 Let w3m itself do the line wrapping for the config file. It works better
1291 than fmt as it can honour pre tags causing less unintentional line breaks.
1296 Ditch a pointless '-r' passed to rm to delete files.
1301 The config-file target now requires less manual intervention and updates
1302 the original config.
1307 Change WDUMP to generate ASCII. Add WDUMP_UTF8 to allow UTF-8 in the
1308 AUTHORS file so the names are right.
1313 Stop pretending that lynx and links are supported for the documentation.
1321 configure improvements:
1325 On Haiku, do not pass -lpthread to the compiler. Haiku's pthreads
1326 implementation is contained in its system library, libroot, so no
1327 additional library needs to be searched.
1328 Patch submitted by Simon South in #3564815.
1333 Additional Haiku-specific improvements. Disable checks intended for
1334 multi-user systems as Haiku is presently single-user. Group Haiku-specific
1335 settings in their own section, following the pattern for Solaris, OS/2 and
1336 AmigaOS. Add additional library-related settings to remove the need for
1337 providing configure with custom LDFLAGS.
1338 Submitted by Simon South in #3574538.
1339 *** Version 3.0.19 Stable ***
1349 <!-- ~~~~~ New section ~~~~~ -->
1351 <sect2 id="upgradersnote">
1352 <title>Note to Upgraders</title>
1355 A quick list of things to be aware of before upgrading from earlier
1356 versions of <application>Privoxy</application>:
1364 The recommended way to upgrade &my-app; is to backup your old
1365 configuration files, install the new ones, verify that &my-app;
1366 is working correctly and finally merge back your changes using
1367 <application>diff</application> and maybe <application>patch</application>.
1370 There are a number of new features in each &my-app; release and
1371 most of them have to be explicitly enabled in the configuration
1372 files. Old configuration files obviously don't do that and due
1373 to syntax changes using old configuration files with a new
1374 &my-app; isn't always possible anyway.
1379 Note that some installers remove earlier versions completely,
1380 including configuration files, therefore you should really save
1381 any important configuration files!
1386 On the other hand, other installers don't overwrite existing configuration
1387 files, thinking you will want to do that yourself.
1392 <filename>standard.action</filename> has been merged into
1393 the <filename>default.action</filename> file.
1398 In the default configuration only fatal errors are logged now.
1399 You can change that in the <link linkend="DEBUG">debug section</link>
1400 of the configuration file. You may also want to enable more verbose
1401 logging until you verified that the new &my-app; version is working
1408 Three other config file settings are now off by default:
1409 <link linkend="enable-remote-toggle">enable-remote-toggle</link>,
1410 <link linkend="enable-remote-http-toggle">enable-remote-http-toggle</link>,
1411 and <link linkend="enable-edit-actions">enable-edit-actions</link>.
1412 If you use or want these, you will need to explicitly enable them, and
1413 be aware of the security issues involved.
1420 What constitutes a <quote>default</quote> configuration has changed,
1421 and you may want to review which actions are <quote>on</quote> by
1422 default. This is primarily a matter of emphasis, but some features
1423 you may have been used to, may now be <quote>off</quote> by default.
1424 There are also a number of new actions and filters you may want to
1425 consider, most of which are not fully incorporated into the default
1426 settings as yet (see above).
1433 The default actions setting is now <literal>Cautious</literal>. Previous
1434 releases had a default setting of <literal>Medium</literal>. Experienced
1435 users may want to adjust this, as it is fairly conservative by &my-app;
1436 standards and past practices. See <ulink
1437 url="http://config.privoxy.org/edit-actions-list?f=default">
1438 http://config.privoxy.org/edit-actions-list?f=default</ulink>. New users
1439 should try the default settings for a while before turning up the volume.
1445 The default setting has filtering turned <emphasis>off</emphasis>, which
1446 subsequently means that compression is <emphasis>on</emphasis>. Remember
1447 that filtering does not work on compressed pages, so if you use, or want to
1448 use, filtering, you will need to force compression off. Example:
1452 { +<link linkend="filter">filter</link>{google} +<link linkend="prevent-compression">prevent-compression</link> }
1456 Or if you use a number of filters, or filter many sites, you may just want
1457 to turn off compression for all sites in
1458 <filename>default.action</filename> (or
1459 <filename>user.action</filename>).
1466 Also, <link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> is
1467 off by default now. If you've liked this feature in the past, you may want
1468 to turn it back on in <filename>user.action</filename> now.
1475 Some installers may not automatically start
1476 <application>Privoxy</application> after installation.
1487 <!-- ~~~~~ New section ~~~~~ -->
1488 <sect1 id="quickstart"><title>Quickstart to Using Privoxy</title>
1494 Install <application>Privoxy</application>. See the <link
1495 linkend="installation">Installation Section</link> below for platform specific
1502 Advanced users and those who want to offer <application>Privoxy</application>
1503 service to more than just their local machine should check the <link
1504 linkend="config">main config file</link>, especially the <link
1505 linkend="access-control">security-relevant</link> options. These are
1512 Start <application>Privoxy</application>, if the installation program has
1513 not done this already (may vary according to platform). See the section
1514 <link linkend="startup">Starting <application>Privoxy</application></link>.
1520 Set your browser to use <application>Privoxy</application> as HTTP and
1521 HTTPS (SSL) <ulink url="http://en.wikipedia.org/wiki/Proxy_server">proxy</ulink>
1522 by setting the proxy configuration for address of
1523 <literal>127.0.0.1</literal> and port <literal>8118</literal>.
1524 <emphasis>DO NOT</emphasis> activate proxying for <literal>FTP</literal> or
1525 any protocols besides HTTP and HTTPS (SSL) unless you intend to prevent your
1526 browser from using these protocols.
1532 Flush your browser's disk and memory caches, to remove any cached ad images.
1533 If using <application>Privoxy</application> to manage
1534 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>,
1535 you should remove any currently stored cookies too.
1541 A default installation should provide a reasonable starting point for
1542 most. There will undoubtedly be occasions where you will want to adjust the
1543 configuration, but that can be dealt with as the need arises. Little
1544 to no initial configuration is required in most cases, you may want
1546 <ulink url="config.html#ENABLE-EDIT-ACTIONS">web-based action editor</ulink> though.
1547 Be sure to read the warnings first.
1550 See the <link linkend="configuration">Configuration section</link> for more
1551 configuration options, and how to customize your installation.
1552 You might also want to look at the <link
1553 linkend="quickstart-ad-blocking">next section</link> for a quick
1554 introduction to how <application>Privoxy</application> blocks ads and
1561 If you experience ads that slip through, innocent images that are
1562 blocked, or otherwise feel the need to fine-tune
1563 <application>Privoxy's</application> behavior, take a look at the <link
1564 linkend="actions-file">actions files</link>. As a quick start, you might
1565 find the <link linkend="act-examples">richly commented examples</link>
1566 helpful. You can also view and edit the actions files through the <ulink
1567 url="http://config.privoxy.org">web-based user interface</ulink>. The
1568 Appendix <quote><link linkend="actionsanat">Troubleshooting: Anatomy of an
1569 Action</link></quote> has hints on how to understand and debug actions that
1570 <quote>misbehave</quote>.
1575 Did anyone test these lately?
1579 For easy access to &my-app;'s most important controls, drag the provided
1580 <link linkend="bookmarklets">Bookmarklets</link> into your browser's
1588 Please see the section <link linkend="contact">Contacting the
1589 Developers</link> on how to report bugs, problems with websites or to get
1596 Now enjoy surfing with enhanced control, comfort and privacy!
1604 <!-- ~~~~~ New section ~~~~~ -->
1606 <sect2 id="quickstart-ad-blocking">
1607 <title>Quickstart to Ad Blocking</title>
1609 NOTE: This section is deliberately redundant for those that don't
1610 want to read the whole thing (which is getting lengthy).
1613 Ad blocking is but one of <application>Privoxy's</application>
1614 array of features. Many of these features are for the technically minded advanced
1615 user. But, ad and banner blocking is surely common ground for everybody.
1618 This section will provide a quick summary of ad blocking so
1619 you can get up to speed quickly without having to read the more extensive
1620 information provided below, though this is highly recommended.
1623 First a bit of a warning ... blocking ads is much like blocking SPAM: the
1624 more aggressive you are about it, the more likely you are to block
1625 things that were not intended. And the more likely that some things
1626 may not work as intended. So there is a trade off here. If you want
1627 extreme ad free browsing, be prepared to deal with more
1628 <quote>problem</quote> sites, and to spend more time adjusting the
1629 configuration to solve these unintended consequences. In short, there is
1630 not an easy way to eliminate <emphasis>all</emphasis> ads. Either take
1631 the easy way and settle for <emphasis>most</emphasis> ads blocked with the
1632 default configuration, or jump in and tweak it for your personal surfing
1633 habits and preferences.
1636 Secondly, a brief explanation of <application>Privoxy's </application>
1637 <quote>actions</quote>. <quote>Actions</quote> in this context, are
1638 the directives we use to tell <application>Privoxy</application> to perform
1639 some task relating to HTTP transactions (i.e. web browsing). We tell
1640 <application>Privoxy</application> to take some <quote>action</quote>. Each
1641 action has a unique name and function. While there are many potential
1642 <application>actions</application> in <application>Privoxy's</application>
1643 arsenal, only a few are used for ad blocking. <link
1644 linkend="actions">Actions</link>, and <link linkend="actions-file">action
1645 configuration files</link>, are explained in depth below.
1648 Actions are specified in <application>Privoxy's</application> configuration,
1649 followed by one or more URLs to which the action should apply. URLs
1650 can actually be URL type <link linkend="af-patterns">patterns</link> that use
1651 wildcards so they can apply potentially to a range of similar URLs. The
1652 actions, together with the URL patterns are called a section.
1655 When you connect to a website, the full URL will either match one or more
1656 of the sections as defined in <application>Privoxy's</application> configuration,
1657 or not. If so, then <application>Privoxy</application> will perform the
1658 respective actions. If not, then nothing special happens. Furthermore, web
1659 pages may contain embedded, secondary URLs that your web browser will
1660 use to load additional components of the page, as it parses the
1661 original page's HTML content. An ad image for instance, is just an URL
1662 embedded in the page somewhere. The image itself may be on the same server,
1663 or a server somewhere else on the Internet. Complex web pages will have many
1664 such embedded URLs. &my-app; can deal with each URL individually, so, for
1665 instance, the main page text is not touched, but images from such-and-such
1670 The most important actions for basic ad blocking are: <literal><link
1671 linkend="block">block</link></literal>, <literal><link
1672 linkend="handle-as-image">handle-as-image</link></literal>,
1674 linkend="handle-as-empty-document">handle-as-empty-document</link></literal>,and
1675 <literal><link linkend="set-image-blocker">set-image-blocker</link></literal>:
1683 <literal><link linkend="block">block</link></literal> - this is perhaps
1684 the single most used action, and is particularly important for ad blocking.
1685 This action stops any contact between your browser and any URL patterns
1686 that match this action's configuration. It can be used for blocking ads,
1687 but also anything that is determined to be unwanted. By itself, it simply
1688 stops any communication with the remote server and sends
1689 <application>Privoxy</application>'s own built-in BLOCKED page instead to
1690 let you now what has happened (with some exceptions, see below).
1696 <literal><link linkend="handle-as-image">handle-as-image</link></literal> -
1697 tells <application>Privoxy</application> to treat this URL as an image.
1698 <application>Privoxy</application>'s default configuration already does this
1699 for all common image types (e.g. GIF), but there are many situations where this
1700 is not so easy to determine. So we'll force it in these cases. This is particularly
1701 important for ad blocking, since only if we know that it's an image of
1702 some kind, can we replace it with an image of our choosing, instead of the
1703 <application>Privoxy</application> BLOCKED page (which would only result in
1704 a <quote>broken image</quote> icon). There are some limitations to this
1705 though. For instance, you can't just brute-force an image substitution for
1706 an entire HTML page in most situations.
1712 <literal><link linkend="handle-as-empty-document">handle-as-empty-document</link></literal> -
1713 sends an empty document instead of <application>Privoxy's</application>
1714 normal BLOCKED HTML page. This is useful for file types that are neither
1715 HTML nor images, such as blocking JavaScript files.
1722 linkend="set-image-blocker">set-image-blocker</link></literal> - tells
1723 <application>Privoxy</application> what to display in place of an ad image that
1724 has hit a block rule. For this to come into play, the URL must match a
1725 <literal><link linkend="block">block</link></literal> action somewhere in the
1726 configuration, <emphasis>and</emphasis>, it must also match an
1727 <literal><link linkend="handle-as-image">handle-as-image</link></literal> action.
1730 The configuration options on what to display instead of the ad are:
1734 <emphasis>pattern</emphasis> - a checkerboard pattern, so that an ad
1735 replacement is obvious. This is the default.
1740 <emphasis>blank</emphasis> - A very small empty GIF image is displayed.
1741 This is the so-called <quote>invisible</quote> configuration option.
1746 <emphasis>http://<URL></emphasis> - A redirect to any image anywhere
1747 of the user's choosing (advanced usage).
1756 Advanced users will eventually want to explore &my-app;
1757 <literal><link linkend="filter">filters</link></literal> as well. Filters
1758 are very different from <literal><link
1759 linkend="block">blocks</link></literal>.
1760 A <quote>block</quote> blocks a site, page, or unwanted contented. Filters
1761 are a way of filtering or modifying what is actually on the page. An example
1762 filter usage: a text replacement of <quote>no-no</quote> for
1763 <quote>nasty-word</quote>. That is a very simple example. This process can be
1764 used for ad blocking, but it is more in the realm of advanced usage and has
1765 some pitfalls to be wary off.
1769 The quickest way to adjust any of these settings is with your browser through
1770 the special <application>Privoxy</application> editor at <ulink
1771 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
1772 (shortcut: <ulink url="http://p.p/">http://p.p/show-status</ulink>). This
1773 is an internal page, and does not require Internet access.
1777 Note that as of <application>Privoxy</application> 3.0.7 beta the
1778 action editor is disabled by default. Check the
1779 <ulink url="config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions
1780 section in the configuration file</ulink> to learn why and in which
1781 cases it's safe to enable again.
1785 If you decided to enable the action editor, select the appropriate
1786 <quote>actions</quote> file, and click
1787 <quote><guibutton>Edit</guibutton></quote>. It is best to put personal or
1788 local preferences in <filename>user.action</filename> since this is not
1789 meant to be overwritten during upgrades, and will over-ride the settings in
1790 other files. Here you can insert new <quote>actions</quote>, and URLs for ad
1791 blocking or other purposes, and make other adjustments to the configuration.
1792 <application>Privoxy</application> will detect these changes automatically.
1796 A quick and simple step by step example:
1804 Right click on the ad image to be blocked, then select
1805 <quote><guimenuitem>Copy Link Location</guimenuitem></quote> from the
1813 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
1818 Find <filename>user.action</filename> in the top section, and click
1819 on <quote><guibutton>Edit</guibutton></quote>:
1822 <!-- image of editor and actions files selections -->
1824 <figure pgwide="0" float="0"><title>Actions Files in Use</title>
1827 <imagedata fileref="files-in-use.jpg" format="jpg">
1830 <phrase>[ Screenshot of Actions Files in Use ]</phrase>
1839 You should have a section with only
1840 <literal><link linkend="block">block</link></literal> listed under
1841 <quote>Actions:</quote>.
1842 If not, click a <quote><guibutton>Insert new section below</guibutton></quote>
1843 button, and in the new section that just appeared, click the
1844 <guibutton>Edit</guibutton> button right under the word <quote>Actions:</quote>.
1845 This will bring up a list of all actions. Find
1846 <literal><link linkend="block">block</link></literal> near the top, and click
1847 in the <quote>Enabled</quote> column, then <quote><guibutton>Submit</guibutton></quote>
1848 just below the list.
1853 Now, in the <literal><link linkend="block">block</link></literal> actions section,
1854 click the <quote><guibutton>Add</guibutton></quote> button, and paste the URL the
1855 browser got from <quote><guimenuitem>Copy Link Location</guimenuitem></quote>.
1856 Remove the <literal>http://</literal> at the beginning of the URL. Then, click
1857 <quote><guibutton>Submit</guibutton></quote> (or
1858 <quote><guibutton>OK</guibutton></quote> if in a pop-up window).
1863 Now go back to the original page, and press <keycap>SHIFT-Reload</keycap>
1864 (or flush all browser caches). The image should be gone now.
1872 This is a very crude and simple example. There might be good reasons to use a
1873 wildcard pattern match to include potentially similar images from the same
1874 site. For a more extensive explanation of <quote>patterns</quote>, and
1875 the entire actions concept, see <link linkend="actions-file">the Actions
1880 For advanced users who want to hand edit their config files, you might want
1881 to now go to the <link linkend="act-examples">Actions Files Tutorial</link>.
1882 The ideas explained therein also apply to the web-based editor.
1885 There are also various
1886 <link linkend="filter">filters</link> that can be used for ad blocking
1887 (filters are a special subset of actions). These
1888 fall into the <quote>advanced</quote> usage category, and are explained in
1889 depth in later sections.
1896 <!-- ~ End section ~ -->
1899 <!-- ~~~~~ New section ~~~~~ -->
1900 <sect1 id="startup">
1901 <title>Starting Privoxy</title>
1903 Before launching <application>Privoxy</application> for the first time, you
1904 will want to configure your browser(s) to use
1905 <application>Privoxy</application> as a HTTP and HTTPS (SSL)
1906 <ulink url="http://en.wikipedia.org/wiki/Proxy_server">proxy</ulink>. The default is
1907 127.0.0.1 (or localhost) for the proxy address, and port 8118 (earlier versions
1908 used port 8000). This is the one configuration step <emphasis>that must be done
1912 Please note that <application>Privoxy</application> can only proxy HTTP and
1913 HTTPS traffic. It will not work with FTP or other protocols.
1916 <!-- image of Mozilla Proxy configuration -->
1918 <figure pgwide="0" float="0"><title>Proxy Configuration Showing
1919 Mozilla/Netscape HTTP and HTTPS (SSL) Settings</title>
1922 <imagedata fileref="proxy_setup.jpg" format="jpg">
1925 <phrase>[ Screenshot of Mozilla Proxy Configuration ]</phrase>
1933 With <application>Firefox</application>, this is typically set under:
1937 <guibutton>Tools</guibutton> -> <guibutton>Options</guibutton> -> <guibutton>Advanced</guibutton> -> <guibutton>Network</guibutton> -><guibutton>Connection</guibutton> -> <guibutton>Settings</guibutton>
1942 Or optionally on some platforms:
1946 <guibutton>Edit</guibutton> -> <guibutton>Preferences</guibutton> -> <guibutton>General</guibutton> -> <guibutton>Connection Settings</guibutton> -> <guibutton>Manual Proxy Configuration</guibutton>
1952 With <application>Netscape</application> (and
1953 <application>Mozilla</application>), this can be set under:
1958 <!-- Mix ascii and gui art, something for everybody -->
1959 <!-- spacing on this is tricky -->
1960 <guibutton>Edit</guibutton> -> <guibutton>Preferences</guibutton> -> <guibutton>Advanced</guibutton> -> <guibutton>Proxies</guibutton> -> <guibutton>HTTP Proxy</guibutton>
1965 For <application>Internet Explorer v.5-7</application>:
1969 <guibutton>Tools</guibutton> -> <guibutton>Internet Options</guibutton> -> <guibutton>Connections</guibutton> -> <guibutton>LAN Settings</guibutton>
1973 Then, check <quote>Use Proxy</quote> and fill in the appropriate info
1974 (Address: 127.0.0.1, Port: 8118). Include HTTPS (SSL), if you want HTTPS
1975 proxy support too (sometimes labeled <quote>Secure</quote>). Make sure any
1976 checkboxes like <quote>Use the same proxy server for all protocols</quote> is
1977 <emphasis>UNCHECKED</emphasis>. You want only HTTP and HTTPS (SSL)!
1980 <!-- image of IE Proxy configuration -->
1982 <figure pgwide="0" float="0"><title>Proxy Configuration Showing
1983 Internet Explorer HTTP and HTTPS (Secure) Settings</title>
1986 <imagedata fileref="proxy2.jpg" format="jpg">
1989 <phrase>[ Screenshot of IE Proxy Configuration ]</phrase>
1997 After doing this, flush your browser's disk and memory caches to force a
1998 re-reading of all pages and to get rid of any ads that may be cached. Remove
1999 any <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>,
2000 if you want <application>Privoxy</application> to manage that. You are now
2001 ready to start enjoying the benefits of using
2002 <application>Privoxy</application>!
2006 <application>Privoxy</application> itself is typically started by specifying the
2007 main configuration file to be used on the command line. If no configuration
2008 file is specified on the command line, <application>Privoxy</application>
2009 will look for a file named <filename>config</filename> in the current
2010 directory. Except on Win32 where it will try <filename>config.txt</filename>.
2013 <sect2 id="start-redhat">
2014 <title>Red Hat and Fedora</title>
2016 A default Red Hat installation may not start &my-app; upon boot. It will use
2017 the file <filename>/etc/privoxy/config</filename> as its main configuration
2022 # /etc/rc.d/init.d/privoxy start
2030 # service privoxy start
2035 <sect2 id="start-debian">
2036 <title>Debian</title>
2038 We use a script. Note that Debian typically starts &my-app; upon booting per
2039 default. It will use the file
2040 <filename>/etc/privoxy/config</filename> as its main configuration
2045 # /etc/init.d/privoxy start
2050 <sect2 id="start-windows">
2051 <title>Windows</title>
2053 Click on the &my-app; Icon to start <application>Privoxy</application>. If no configuration file is
2054 specified on the command line, <application>Privoxy</application> will look
2055 for a file named <filename>config.txt</filename>. Note that Windows will
2056 automatically start &my-app; when the system starts if you chose that option
2060 <application>Privoxy</application> can run with full Windows service functionality.
2061 On Windows only, the &my-app; program has two new command line arguments
2062 to install and uninstall &my-app; as a service. See the
2063 <link linkend="installation-pack-win">Windows Installation
2064 instructions</link> for details.
2068 <sect2 id="start-unices">
2069 <title>Solaris, NetBSD, FreeBSD, HP-UX and others</title>
2071 Example Unix startup command:
2075 # /usr/sbin/privoxy /etc/privoxy/config
2080 <sect2 id="start-os2">
2083 During installation, <application>Privoxy</application> is configured to
2084 start automatically when the system restarts. You can start it manually by
2085 double-clicking on the <application>Privoxy</application> icon in the
2086 <application>Privoxy</application> folder.
2090 <sect2 id="start-macosx">
2091 <title>Mac OS X</title>
2093 After downloading the privoxy software, unzip the downloaded file by
2094 double-clicking on the zip file icon. Then, double-click on the
2095 installer package icon and follow the installation process.
2098 The privoxy service will automatically start after a successful
2099 installation. In addition, the privoxy service will automatically
2100 start every time your computer starts up.
2103 To prevent the privoxy service from automatically starting when your
2104 computer starts up, remove or rename the folder named
2105 /Library/StartupItems/Privoxy.
2108 A simple application named Privoxy Utility has been created which
2109 enables administrators to easily start and stop the privoxy service.
2112 In addition, the Privoxy Utility presents a simple way for
2113 administrators to edit the various privoxy config files. A method
2114 to uninstall the software is also available.
2117 An administrator username and password must be supplied in order for
2118 the Privoxy Utility to perform any of the tasks.
2123 <sect2 id="start-amigaos">
2124 <title>AmigaOS</title>
2126 Start <application>Privoxy</application> (with RUN <>NIL:) in your
2127 <filename>startnet</filename> script (AmiTCP), in
2128 <filename>s:user-startup</filename> (RoadShow), as startup program in your
2129 startup script (Genesis), or as startup action (Miami and MiamiDx).
2130 <application>Privoxy</application> will automatically quit when you quit your
2131 TCP/IP stack (just ignore the harmless warning your TCP/IP stack may display that
2132 <application>Privoxy</application> is still running).
2136 <sect2 id="start-gentoo">
2137 <title>Gentoo</title>
2139 A script is again used. It will use the file <filename>/etc/privoxy/config
2140 </filename> as its main configuration file.
2144 /etc/init.d/privoxy start
2148 Note that <application>Privoxy</application> is not automatically started at
2149 boot time by default. You can change this with the <literal>rc-update</literal>
2154 rc-update add privoxy default
2162 See the section <link linkend="cmdoptions">Command line options</link> for
2166 must find a better place for this paragraph
2169 The included default configuration files should give a reasonable starting
2170 point. Most of the per site configuration is done in the
2171 <ulink url="actions-file.html"><quote>actions</quote></ulink> files. These are
2172 where various cookie actions are defined, ad and banner blocking, and other
2173 aspects of <application>Privoxy</application> configuration. There are several
2174 such files included, with varying levels of aggressiveness.
2178 You will probably want to keep an eye out for sites for which you may prefer
2179 persistent cookies, and add these to your actions configuration as needed. By
2180 default, most of these will be accepted only during the current browser
2181 session (aka <quote>session cookies</quote>), unless you add them to the
2182 configuration. If you want the browser to handle this instead, you will need
2183 to edit <filename>user.action</filename> (or through the web based interface)
2184 and disable this feature. If you use more than one browser, it would make
2185 more sense to let <application>Privoxy</application> handle this. In which
2186 case, the browser(s) should be set to accept all cookies.
2190 Another feature where you will probably want to define exceptions for trusted
2191 sites is the popup-killing (through <ulink
2192 url="actions-file.html#FILTER-POPUPS"><quote>+filter{popups}</quote></ulink>),
2193 because your favorite shopping, banking, or leisure site may need
2194 popups (explained below).
2198 <application>Privoxy</application> does not support all of the optional HTTP/1.1
2199 features yet. In the unlikely event that you experience inexplicable problems
2200 with browsers that use HTTP/1.1 per default
2201 (like <application>Mozilla</application> or recent versions of I.E.), you might
2202 try to force HTTP/1.0 compatibility. For Mozilla, look under <literal>Edit ->
2203 Preferences -> Debug -> Networking</literal>.
2204 Alternatively, set the <quote>+downgrade-http-version</quote> config option in
2205 <filename>default.action</filename> which will downgrade your browser's HTTP
2206 requests from HTTP/1.1 to HTTP/1.0 before processing them.
2210 After running <application>Privoxy</application> for a while, you can
2211 start to fine tune the configuration to suit your personal, or site,
2212 preferences and requirements. There are many, many aspects that can
2213 be customized. <quote>Actions</quote>
2214 can be adjusted by pointing your browser to
2215 <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
2216 (shortcut: <ulink url="http://p.p/">http://p.p/</ulink>),
2217 and then follow the link to <quote>View & Change the Current Configuration</quote>.
2218 (This is an internal page and does not require Internet access.)
2222 In fact, various aspects of <application>Privoxy</application>
2223 configuration can be viewed from this page, including
2224 current configuration parameters, source code version numbers,
2225 the browser's request headers, and <quote>actions</quote> that apply
2226 to a given URL. In addition to the actions file
2227 editor mentioned above, <application>Privoxy</application> can also
2228 be turned <quote>on</quote> and <quote>off</quote> (toggled) from this page.
2232 If you encounter problems, try loading the page without
2233 <application>Privoxy</application>. If that helps, enter the URL where
2234 you have the problems into <ulink url="http://p.p/show-url-info">the browser
2235 based rule tracing utility</ulink>. See which rules apply and why, and
2236 then try turning them off for that site one after the other, until the problem
2237 is gone. When you have found the culprit, you might want to turn the rest on
2242 If the above paragraph sounds gibberish to you, you might want to <link
2243 linkend="actions-file">read more about the actions concept</link>
2244 or even dive deep into the <link linkend="actionsanat">Appendix
2249 If you can't get rid of the problem at all, think you've found a bug in
2250 Privoxy, want to propose a new feature or smarter rules, please see the
2251 section <link linkend="contact"><quote>Contacting the
2252 Developers</quote></link> below.
2257 <!-- ~~~~~ New section ~~~~~ -->
2258 <sect2 id="cmdoptions">
2259 <title>Command Line Options</title>
2261 <application>Privoxy</application> may be invoked with the following
2262 command-line options:
2270 <emphasis>--config-test</emphasis>
2273 Exit after loading the configuration files before binding to
2274 the listen address. The exit code signals whether or not the
2275 configuration files have been successfully loaded.
2278 If the exit code is 1, at least one of the configuration files
2279 is invalid, if it is 0, all the configuration files have been
2280 successfully loaded (but may still contain errors that can
2281 currently only be detected at run time).
2284 This option doesn't affect the log setting, combination with
2285 <emphasis>--no-daemon</emphasis> is recommended if a configured
2286 log file shouldn't be used.
2291 <emphasis>--version</emphasis>
2294 Print version info and exit. Unix only.
2299 <emphasis>--help</emphasis>
2302 Print short usage info and exit. Unix only.
2307 <emphasis>--no-daemon</emphasis>
2310 Don't become a daemon, i.e. don't fork and become process group
2311 leader, and don't detach from controlling tty. Unix only.
2316 <emphasis>--pidfile FILE</emphasis>
2319 On startup, write the process ID to <emphasis>FILE</emphasis>. Delete the
2320 <emphasis>FILE</emphasis> on exit. Failure to create or delete the
2321 <emphasis>FILE</emphasis> is non-fatal. If no <emphasis>FILE</emphasis>
2322 option is given, no PID file will be used. Unix only.
2327 <emphasis>--user USER[.GROUP]</emphasis>
2330 After (optionally) writing the PID file, assume the user ID of
2331 <emphasis>USER</emphasis>, and if included the GID of GROUP. Exit if the
2332 privileges are not sufficient to do so. Unix only.
2337 <emphasis>--chroot</emphasis>
2340 Before changing to the user ID given in the <emphasis>--user</emphasis> option,
2341 chroot to that user's home directory, i.e. make the kernel pretend to the &my-app;
2342 process that the directory tree starts there. If set up carefully, this can limit
2343 the impact of possible vulnerabilities in &my-app; to the files contained in that hierarchy.
2349 <emphasis>--pre-chroot-nslookup hostname</emphasis>
2352 Specifies a hostname to look up before doing a chroot. On some systems, initializing the
2353 resolver library involves reading config files from /etc and/or loading additional shared
2354 libraries from /lib. On these systems, doing a hostname lookup before the chroot reduces
2355 the number of files that must be copied into the chroot tree.
2358 For fastest startup speed, a good value is a hostname that is not in /etc/hosts but that
2359 your local name server (listed in /etc/resolv.conf) can resolve without recursion
2360 (that is, without having to ask any other name servers). The hostname need not exist,
2361 but if it doesn't, an error message (which can be ignored) will be output.
2367 <emphasis>configfile</emphasis>
2370 If no <emphasis>configfile</emphasis> is included on the command line,
2371 <application>Privoxy</application> will look for a file named
2372 <quote>config</quote> in the current directory (except on Win32
2373 where it will look for <quote>config.txt</quote> instead). Specify
2374 full path to avoid confusion. If no config file is found,
2375 <application>Privoxy</application> will fail to start.
2383 On <application>MS Windows</application> only there are two additional
2384 command-line options to allow <application>Privoxy</application> to install and
2385 run as a <emphasis>service</emphasis>. See the
2386 <link linkend="installation-pack-win">Window Installation section</link>
2394 <!-- ~ End section ~ -->
2397 <!-- ~~~~~ New section ~~~~~ -->
2398 <sect1 id="configuration"><title>Privoxy Configuration</title>
2400 All <application>Privoxy</application> configuration is stored
2401 in text files. These files can be edited with a text editor.
2402 Many important aspects of <application>Privoxy</application> can
2403 also be controlled easily with a web browser.
2407 <!-- ~~~~~ New section ~~~~~ -->
2410 <title>Controlling Privoxy with Your Web Browser</title>
2412 <application>Privoxy</application>'s user interface can be reached through the special
2413 URL <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
2414 (shortcut: <ulink url="http://p.p/">http://p.p/</ulink>),
2415 which is a built-in page and works without Internet access.
2416 You will see the following section:
2420 <!-- Needs to be put in a table and colorized -->
2423 <bridgehead renderas="sect2"> Privoxy Menu</bridgehead>
2427 ▪ <ulink url="http://config.privoxy.org/show-status">View & change the current configuration</ulink>
2430 ▪ <ulink url="http://config.privoxy.org/show-version">View the source code version numbers</ulink>
2433 ▪ <ulink url="http://config.privoxy.org/show-request">View the request headers.</ulink>
2436 ▪ <ulink url="http://config.privoxy.org/show-url-info">Look up which actions apply to a URL and why</ulink>
2439 ▪ <ulink url="http://config.privoxy.org/toggle">Toggle Privoxy on or off</ulink>
2442 ▪ <ulink
2443 url="http://www.privoxy.org/&p-version;/user-manual/">Documentation</ulink>
2451 This should be self-explanatory. Note the first item leads to an editor for the
2452 <link linkend="actions-file">actions files</link>, which is where the ad, banner,
2453 cookie, and URL blocking magic is configured as well as other advanced features of
2454 <application>Privoxy</application>. This is an easy way to adjust various
2455 aspects of <application>Privoxy</application> configuration. The actions
2456 file, and other configuration files, are explained in detail below.
2460 <quote>Toggle Privoxy On or Off</quote> is handy for sites that might
2461 have problems with your current actions and filters. You can in fact use
2462 it as a test to see whether it is <application>Privoxy</application>
2463 causing the problem or not. <application>Privoxy</application> continues
2464 to run as a proxy in this case, but all manipulation is disabled, i.e.
2465 <application>Privoxy</application> acts like a normal forwarding proxy. There
2466 is even a toggle <link linkend="bookmarklets">Bookmarklet</link> offered, so
2467 that you can toggle <application>Privoxy</application> with one click from
2472 Note that several of the features described above are disabled by default
2473 in <application>Privoxy</application> 3.0.7 beta and later.
2475 <ulink url="config.html">configuration file</ulink> to learn why
2476 and in which cases it's safe to enable them again.
2481 <!-- ~ End section ~ -->
2486 <!-- ~~~~~ New section ~~~~~ -->
2488 <sect2 id="confoverview">
2489 <title>Configuration Files Overview</title>
2491 For Unix, *BSD and Linux, all configuration files are located in
2492 <filename>/etc/privoxy/</filename> by default. For MS Windows, OS/2, and
2493 AmigaOS these are all in the same directory as the
2494 <application>Privoxy</application> executable. <![%p-not-stable;[ The name
2495 and number of configuration files has changed from previous versions, and is
2496 subject to change as development progresses.]]>
2500 The installed defaults provide a reasonable starting point, though
2501 some settings may be aggressive by some standards. For the time being, the
2502 principle configuration files are:
2510 The <link linkend="config">main configuration file</link> is named <filename>config</filename>
2511 on Linux, Unix, BSD, OS/2, and AmigaOS and <filename>config.txt</filename>
2512 on Windows. This is a required file.
2518 <filename>match-all.action</filename> is used to define which <quote>actions</quote>
2519 relating to banner-blocking, images, pop-ups, content modification, cookie handling
2520 etc should be applied by default. It should be the first actions file loaded.
2523 <filename>default.action</filename> defines many exceptions (both positive and negative)
2524 from the default set of actions that's configured in <filename>match-all.action</filename>.
2525 It should be the second actions file loaded and shouldn't be edited by the user.
2528 Multiple actions files may be defined in <filename>config</filename>. These
2529 are processed in the order they are defined. Local customizations and locally
2530 preferred exceptions to the default policies as defined in
2531 <filename>match-all.action</filename> (which you will most probably want
2532 to define sooner or later) are best applied in <filename>user.action</filename>,
2533 where you can preserve them across upgrades. The file isn't installed by all
2534 installers, but you can easily create it yourself with a text editor.
2537 There is also a web based editor that can be accessed from
2539 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
2541 url="http://p.p/show-status">http://p.p/show-status</ulink>) for the
2542 various actions files.
2548 <quote>Filter files</quote> (the <link linkend="filter-file">filter
2549 file</link>) can be used to re-write the raw page content, including
2550 viewable text as well as embedded HTML and JavaScript, and whatever else
2551 lurks on any given web page. The filtering jobs are only pre-defined here;
2552 whether to apply them or not is up to the actions files.
2553 <filename>default.filter</filename> includes various filters made
2554 available for use by the developers. Some are much more intrusive than
2555 others, and all should be used with caution. You may define additional
2556 filter files in <filename>config</filename> as you can with
2557 actions files. We suggest <filename>user.filter</filename> for any
2558 locally defined filters or customizations.
2566 The syntax of the configuration and filter files may change between different
2567 Privoxy versions, unfortunately some enhancements cost backwards compatibility.
2568 <!-- Add link to documentation-->
2572 All files use the <quote><literal>#</literal></quote> character to denote a
2573 comment (the rest of the line will be ignored) and understand line continuation
2574 through placing a backslash ("<literal>\</literal>") as the very last character
2575 in a line. If the <literal>#</literal> is preceded by a backslash, it looses
2576 its special function. Placing a <literal>#</literal> in front of an otherwise
2577 valid configuration line to prevent it from being interpreted is called "commenting
2578 out" that line. Blank lines are ignored.
2582 The actions files and filter files
2583 can use Perl style <link linkend="regex">regular expressions</link> for
2584 maximum flexibility.
2588 After making any changes, there is no need to restart
2589 <application>Privoxy</application> in order for the changes to take
2590 effect. <application>Privoxy</application> detects such changes
2591 automatically. Note, however, that it may take one or two additional
2592 requests for the change to take effect. When changing the listening address
2593 of <application>Privoxy</application>, these <quote>wake up</quote> requests
2594 must obviously be sent to the <emphasis>old</emphasis> listening address.
2599 While under development, the configuration content is subject to change.
2600 The below documentation may not be accurate by the time you read this.
2601 Also, what constitutes a <quote>default</quote> setting, may change, so
2602 please check all your configuration files on important issues.
2608 <!-- ~ End section ~ -->
2611 <!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
2613 <!-- **************************************************** -->
2614 <!-- Include config.sgml here -->
2615 <!-- This is where the entire config file is detailed. -->
2617 <!-- end include -->
2620 <!-- ~ End section ~ -->
2624 <!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
2626 <sect1 id="actions-file"><title>Actions Files</title>
2630 XXX: similar descriptions are in the Configuration Files sections.
2631 We should only describe them at one place.
2634 The actions files are used to define what <emphasis>actions</emphasis>
2635 <application>Privoxy</application> takes for which URLs, and thus determines
2636 how ad images, cookies and various other aspects of HTTP content and
2637 transactions are handled, and on which sites (or even parts thereof).
2638 There are a number of such actions, with a wide range of functionality.
2639 Each action does something a little different.
2640 These actions give us a veritable arsenal of tools with which to exert
2641 our control, preferences and independence. Actions can be combined so that
2642 their effects are aggregated when applied against a given set of URLs.
2646 are three action files included with <application>Privoxy</application> with
2653 <filename>match-all.action</filename> - is used to define which
2654 <quote>actions</quote> relating to banner-blocking, images, pop-ups,
2655 content modification, cookie handling etc should be applied by default.
2656 It should be the first actions file loaded
2661 <filename>default.action</filename> - defines many exceptions (both
2662 positive and negative) from the default set of actions that's configured
2663 in <filename>match-all.action</filename>. It is a set of rules that should
2664 work reasonably well as-is for most users. This file is only supposed to
2665 be edited by the developers. It should be the second actions file loaded.
2670 <filename>user.action</filename> - is intended to be for local site
2671 preferences and exceptions. As an example, if your ISP or your bank
2672 has specific requirements, and need special handling, this kind of
2673 thing should go here. This file will not be upgraded.
2678 <guibutton>Edit</guibutton> <guibutton>Set to Cautious</guibutton> <guibutton>Set to Medium</guibutton> <guibutton>Set to Advanced</guibutton>
2681 These have increasing levels of aggressiveness <emphasis>and have no
2682 influence on your browsing unless you select them explicitly in the
2683 editor</emphasis>. A default installation should be pre-set to
2684 <literal>Cautious</literal>. New users should try this for a while before
2685 adjusting the settings to more aggressive levels. The more aggressive
2686 the settings, then the more likelihood there is of problems such as sites
2687 not working as they should.
2690 The <guibutton>Edit</guibutton> button allows you to turn each
2691 action on/off individually for fine-tuning. The <guibutton>Cautious</guibutton>
2692 button changes the actions list to low/safe settings which will activate
2693 ad blocking and a minimal set of &my-app;'s features, and subsequently
2694 there will be less of a chance for accidental problems. The
2695 <guibutton>Medium</guibutton> button sets the list to a medium level of
2696 other features and a low level set of privacy features. The
2697 <guibutton>Advanced</guibutton> button sets the list to a high level of
2698 ad blocking and medium level of privacy. See the chart below. The latter
2699 three buttons over-ride any changes via with the
2700 <guibutton>Edit</guibutton> button. More fine-tuning can be done in the
2701 lower sections of this internal page.
2704 While the actions file editor allows to enable these settings in all
2705 actions files, they are only supposed to be enabled in the first one
2706 to make sure you don't unintentionally overrule earlier rules.
2709 The default profiles, and their associated actions, as pre-defined in
2710 <filename>default.action</filename> are:
2713 <table frame=all><title>Default Configurations</title>
2714 <tgroup cols=4 align=left colsep=1 rowsep=1>
2715 <colspec colname=c1>
2716 <colspec colname=c2>
2717 <colspec colname=c3>
2718 <colspec colname=c4>
2721 <entry>Feature</entry>
2722 <entry>Cautious</entry>
2723 <entry>Medium</entry>
2724 <entry>Advanced</entry>
2729 <!-- <entry>f1</entry> -->
2730 <!-- <entry>f2</entry> -->
2731 <!-- <entry>f3</entry> -->
2732 <!-- <entry>f4</entry> -->
2738 <entry>Ad-blocking Aggressiveness</entry>
2739 <entry>medium</entry>
2745 <entry>Ad-filtering by size</entry>
2752 <entry>Ad-filtering by link</entry>
2758 <entry>Pop-up killing</entry>
2759 <entry>blocks only</entry>
2760 <entry>blocks only</entry>
2761 <entry>blocks only</entry>
2765 <entry>Privacy Features</entry>
2767 <entry>medium</entry>
2768 <entry>medium/high</entry>
2772 <entry>Cookie handling</entry>
2774 <entry>session-only</entry>
2779 <entry>Referer forging</entry>
2786 <entry>GIF de-animation</entry>
2793 <entry>Fast redirects</entry>
2800 <entry>HTML taming</entry>
2807 <entry>JavaScript taming</entry>
2814 <entry>Web-bug killing</entry>
2821 <entry>Image tag reordering</entry>
2837 The list of actions files to be used are defined in the main configuration
2838 file, and are processed in the order they are defined (e.g.
2839 <filename>default.action</filename> is typically processed before
2840 <filename>user.action</filename>). The content of these can all be viewed and
2842 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>.
2843 The over-riding principle when applying actions, is that the last action that
2844 matches a given URL wins. The broadest, most general rules go first
2845 (defined in <filename>default.action</filename>),
2846 followed by any exceptions (typically also in
2847 <filename>default.action</filename>), which are then followed lastly by any
2848 local preferences (typically in <emphasis>user</emphasis><filename>.action</filename>).
2849 Generally, <filename>user.action</filename> has the last word.
2853 An actions file typically has multiple sections. If you want to use
2854 <quote>aliases</quote> in an actions file, you have to place the (optional)
2855 <link linkend="aliases">alias section</link> at the top of that file.
2856 Then comes the default set of rules which will apply universally to all
2857 sites and pages (be <emphasis>very careful</emphasis> with using such a
2858 universal set in <filename>user.action</filename> or any other actions file after
2859 <filename>default.action</filename>, because it will override the result
2860 from consulting any previous file). And then below that,
2861 exceptions to the defined universal policies. You can regard
2862 <filename>user.action</filename> as an appendix to <filename>default.action</filename>,
2863 with the advantage that it is a separate file, which makes preserving your
2864 personal settings across <application>Privoxy</application> upgrades easier.
2868 Actions can be used to block anything you want, including ads, banners, or
2869 just some obnoxious URL whose content you would rather not see. Cookies can be accepted
2870 or rejected, or accepted only during the current browser session (i.e. not
2871 written to disk), content can be modified, some JavaScripts tamed, user-tracking
2872 fooled, and much more. See below for a <link linkend="actions">complete list
2876 <!-- ~~~~~ New section ~~~~~ -->
2878 <title>Finding the Right Mix</title>
2880 Note that some <link linkend="actions">actions</link>, like cookie suppression
2881 or script disabling, may render some sites unusable that rely on these
2882 techniques to work properly. Finding the right mix of actions is not always easy and
2883 certainly a matter of personal taste. And, things can always change, requiring
2884 refinements in the configuration. In general, it can be said that the more
2885 <quote>aggressive</quote> your default settings (in the top section of the
2886 actions file) are, the more exceptions for <quote>trusted</quote> sites you
2887 will have to make later. If, for example, you want to crunch all cookies per
2888 default, you'll have to make exceptions from that rule for sites that you
2889 regularly use and that require cookies for actually useful purposes, like maybe
2890 your bank, favorite shop, or newspaper.
2894 We have tried to provide you with reasonable rules to start from in the
2895 distribution actions files. But there is no general rule of thumb on these
2896 things. There just are too many variables, and sites are constantly changing.
2897 Sooner or later you will want to change the rules (and read this chapter again :).
2901 <!-- ~~~~~ New section ~~~~~ -->
2903 <title>How to Edit</title>
2905 The easiest way to edit the actions files is with a browser by
2906 using our browser-based editor, which can be reached from <ulink
2907 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>.
2908 Note: the config file option <link
2909 linkend="enable-edit-actions">enable-edit-actions</link> must be enabled for
2910 this to work. The editor allows both fine-grained control over every single
2911 feature on a per-URL basis, and easy choosing from wholesale sets of defaults
2912 like <quote>Cautious</quote>, <quote>Medium</quote> or
2913 <quote>Advanced</quote>. Warning: the <quote>Advanced</quote> setting is more
2914 aggressive, and will be more likely to cause problems for some sites.
2915 Experienced users only!
2919 If you prefer plain text editing to GUIs, you can of course also directly edit the
2920 the actions files with your favorite text editor. Look at
2921 <filename>default.action</filename> which is richly commented with many
2927 <sect2 id="actions-apply">
2928 <title>How Actions are Applied to Requests</title>
2930 Actions files are divided into sections. There are special sections,
2931 like the <quote><link linkend="aliases">alias</link></quote> sections which will
2932 be discussed later. For now let's concentrate on regular sections: They have a
2933 heading line (often split up to multiple lines for readability) which consist
2934 of a list of actions, separated by whitespace and enclosed in curly braces.
2935 Below that, there is a list of URL and tag patterns, each on a separate line.
2939 To determine which actions apply to a request, the URL of the request is
2940 compared to all URL patterns in each <quote>action file</quote>.
2941 Every time it matches, the list of applicable actions for the request is
2942 incrementally updated, using the heading of the section in which the
2943 pattern is located. The same is done again for tags and tag patterns later on.
2947 If multiple applying sections set the same action differently,
2948 the last match wins. If not, the effects are aggregated.
2949 E.g. a URL might match a regular section with a heading line of <literal>{
2950 +<link linkend="handle-as-image">handle-as-image</link> }</literal>,
2951 then later another one with just <literal>{
2952 +<link linkend="block">block</link> }</literal>, resulting
2953 in <emphasis>both</emphasis> actions to apply. And there may well be
2954 cases where you will want to combine actions together. Such a section then
2960 { +<literal>handle-as-image</literal> +<literal>block{Banner ads.}</literal> }
2961 # Block these as if they were images. Send no block page.
2963 media.example.com/.*banners
2964 .example.com/images/ads/</screen>
2968 You can trace this process for URL patterns and any given URL by visiting <ulink
2969 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>.
2973 Examples and more detail on this is provided in the Appendix, <link linkend="ACTIONSANAT">
2974 Troubleshooting: Anatomy of an Action</link> section.
2978 <!-- ~~~~~ New section ~~~~~ -->
2979 <sect2 id="af-patterns">
2980 <title>Patterns</title>
2982 As mentioned, <application>Privoxy</application> uses <quote>patterns</quote>
2983 to determine what <emphasis>actions</emphasis> might apply to which sites and
2984 pages your browser attempts to access. These <quote>patterns</quote> use wild
2985 card type <emphasis>pattern</emphasis> matching to achieve a high degree of
2986 flexibility. This allows one expression to be expanded and potentially match
2987 against many similar patterns.
2991 Generally, an URL pattern has the form
2992 <literal><domain><port>/<path></literal>, where the
2993 <literal><domain></literal>, the <literal><port></literal>
2994 and the <literal><path></literal> are optional. (This is why the special
2995 <literal>/</literal> pattern matches all URLs). Note that the protocol
2996 portion of the URL pattern (e.g. <literal>http://</literal>) should
2997 <emphasis>not</emphasis> be included in the pattern. This is assumed already!
3000 The pattern matching syntax is different for the domain and path parts of
3001 the URL. The domain part uses a simple globbing type matching technique,
3002 while the path part uses more flexible
3003 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
3004 Expressions</quote></ulink> (POSIX 1003.2).
3007 The port part of a pattern is a decimal port number preceded by a colon
3008 (<literal>:</literal>). If the domain part contains a numerical IPv6 address,
3009 it has to be put into angle brackets
3010 (<literal><</literal>, <literal>></literal>).
3015 <term><literal>www.example.com/</literal></term>
3018 is a domain-only pattern and will match any request to <literal>www.example.com</literal>,
3019 regardless of which document on that server is requested. So ALL pages in
3020 this domain would be covered by the scope of this action. Note that a
3021 simple <literal>example.com</literal> is different and would NOT match.
3026 <term><literal>www.example.com</literal></term>
3029 means exactly the same. For domain-only patterns, the trailing <literal>/</literal> may
3035 <term><literal>www.example.com/index.html</literal></term>
3038 matches all the documents on <literal>www.example.com</literal>
3039 whose name starts with <literal>/index.html</literal>.
3044 <term><literal>www.example.com/index.html$</literal></term>
3047 matches only the single document <literal>/index.html</literal>
3048 on <literal>www.example.com</literal>.
3053 <term><literal>/index.html$</literal></term>
3056 matches the document <literal>/index.html</literal>, regardless of the domain,
3057 i.e. on <emphasis>any</emphasis> web server anywhere.
3062 <term><literal>/</literal></term>
3065 Matches any URL because there's no requirement for either the
3066 domain or the path to match anything.
3071 <term><literal>:8000/</literal></term>
3074 Matches any URL pointing to TCP port 8000.
3079 <term><literal><2001:db8::1>/</literal></term>
3082 Matches any URL with the host address <literal>2001:db8::1</literal>.
3083 (Note that the real URL uses plain brackets, not angle brackets.)
3088 <term><literal>index.html</literal></term>
3091 matches nothing, since it would be interpreted as a domain name and
3092 there is no top-level domain called <literal>.html</literal>. So its
3100 <!-- ~~~~~ New section ~~~~~ -->
3101 <sect3><title>The Domain Pattern</title>
3104 The matching of the domain part offers some flexible options: if the
3105 domain starts or ends with a dot, it becomes unanchored at that end.
3111 <term><literal>.example.com</literal></term>
3114 matches any domain with first-level domain <literal>com</literal>
3115 and second-level domain <literal>example</literal>.
3116 For example <literal>www.example.com</literal>,
3117 <literal>example.com</literal> and <literal>foo.bar.baz.example.com</literal>.
3118 Note that it wouldn't match if the second-level domain was <literal>another-example</literal>.
3123 <term><literal>www.</literal></term>
3126 matches any domain that <emphasis>STARTS</emphasis> with
3127 <literal>www.</literal> (It also matches the domain
3128 <literal>www</literal> but most of the time that doesn't matter.)
3133 <term><literal>.example.</literal></term>
3136 matches any domain that <emphasis>CONTAINS</emphasis> <literal>.example.</literal>.
3137 And, by the way, also included would be any files or documents that exist
3138 within that domain since no path limitations are specified. (Correctly
3139 speaking: It matches any FQDN that contains <literal>example</literal> as
3140 a domain.) This might be <literal>www.example.com</literal>,
3141 <literal>news.example.de</literal>, or
3142 <literal>www.example.net/cgi/testing.pl</literal> for instance. All these
3150 Additionally, there are wild-cards that you can use in the domain names
3151 themselves. These work similarly to shell globbing type wild-cards:
3152 <quote>*</quote> represents zero or more arbitrary characters (this is
3154 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
3155 Expression</quote></ulink> based syntax of <quote>.*</quote>),
3156 <quote>?</quote> represents any single character (this is equivalent to the
3157 regular expression syntax of a simple <quote>.</quote>), and you can define
3158 <quote>character classes</quote> in square brackets which is similar to
3159 the same regular expression technique. All of this can be freely mixed:
3164 <term><literal>ad*.example.com</literal></term>
3167 matches <quote>adserver.example.com</quote>,
3168 <quote>ads.example.com</quote>, etc but not <quote>sfads.example.com</quote>
3173 <term><literal>*ad*.example.com</literal></term>
3176 matches all of the above, and then some.
3181 <term><literal>.?pix.com</literal></term>
3184 matches <literal>www.ipix.com</literal>,
3185 <literal>pictures.epix.com</literal>, <literal>a.b.c.d.e.upix.com</literal> etc.
3190 <term><literal>www[1-9a-ez].example.c*</literal></term>
3193 matches <literal>www1.example.com</literal>,
3194 <literal>www4.example.cc</literal>, <literal>wwwd.example.cy</literal>,
3195 <literal>wwwz.example.com</literal> etc., but <emphasis>not</emphasis>
3196 <literal>wwww.example.com</literal>.
3203 While flexible, this is not the sophistication of full regular expression based syntax.
3208 <!-- ~ End section ~ -->
3211 <!-- ~~~~~ New section ~~~~~ -->
3212 <sect3><title>The Path Pattern</title>
3215 <application>Privoxy</application> uses <quote>modern</quote> POSIX 1003.2
3216 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
3217 Expressions</quote></ulink> for matching the path portion (after the slash),
3218 and is thus more flexible.
3222 There is an <link linkend="regex">Appendix</link> with a brief quick-start into regular
3223 expressions, you also might want to have a look at your operating system's documentation
3224 on regular expressions (try <literal>man re_format</literal>).
3228 Note that the path pattern is automatically left-anchored at the <quote>/</quote>,
3229 i.e. it matches as if it would start with a <quote>^</quote> (regular expression speak
3230 for the beginning of a line).
3234 Please also note that matching in the path is <emphasis>CASE INSENSITIVE</emphasis>
3235 by default, but you can switch to case sensitive at any point in the pattern by using the
3236 <quote>(?-i)</quote> switch: <literal>www.example.com/(?-i)PaTtErN.*</literal> will match
3237 only documents whose path starts with <literal>PaTtErN</literal> in
3238 <emphasis>exactly</emphasis> this capitalization.
3243 <term><literal>.example.com/.*</literal></term>
3246 Is equivalent to just <quote>.example.com</quote>, since any documents
3247 within that domain are matched with or without the <quote>.*</quote>
3248 regular expression. This is redundant
3253 <term><literal>.example.com/.*/index.html$</literal></term>
3256 Will match any page in the domain of <quote>example.com</quote> that is
3257 named <quote>index.html</quote>, and that is part of some path. For
3258 example, it matches <quote>www.example.com/testing/index.html</quote> but
3259 NOT <quote>www.example.com/index.html</quote> because the regular
3260 expression called for at least two <quote>/'s</quote>, thus the path
3261 requirement. It also would match
3262 <quote>www.example.com/testing/index_html</quote>, because of the
3263 special meta-character <quote>.</quote>.
3268 <term><literal>.example.com/(.*/)?index\.html$</literal></term>
3271 This regular expression is conditional so it will match any page
3272 named <quote>index.html</quote> regardless of path which in this case can
3273 have one or more <quote>/'s</quote>. And this one must contain exactly
3274 <quote>.html</quote> (but does not have to end with that!).
3279 <term><literal>.example.com/(.*/)(ads|banners?|junk)</literal></term>
3282 This regular expression will match any path of <quote>example.com</quote>
3283 that contains any of the words <quote>ads</quote>, <quote>banner</quote>,
3284 <quote>banners</quote> (because of the <quote>?</quote>) or <quote>junk</quote>.
3285 The path does not have to end in these words, just contain them.
3290 <term><literal>.example.com/(.*/)(ads|banners?|junk)/.*\.(jpe?g|gif|png)$</literal></term>
3293 This is very much the same as above, except now it must end in either
3294 <quote>.jpg</quote>, <quote>.jpeg</quote>, <quote>.gif</quote> or <quote>.png</quote>. So this
3295 one is limited to common image formats.
3302 There are many, many good examples to be found in <filename>default.action</filename>,
3303 and more tutorials below in <link linkend="regex">Appendix on regular expressions</link>.
3308 <!-- ~ End section ~ -->
3311 <!-- ~~~~~ New section ~~~~~ -->
3312 <sect3 id="tag-pattern"><title>The Tag Pattern</title>
3315 Tag patterns are used to change the applying actions based on the
3316 request's tags. Tags can be created with either the
3317 <link linkend="CLIENT-HEADER-TAGGER">client-header-tagger</link>
3318 or the <link linkend="SERVER-HEADER-TAGGER">server-header-tagger</link> action.
3322 Tag patterns have to start with <quote>TAG:</quote>, so &my-app;
3323 can tell them apart from URL patterns. Everything after the colon
3324 including white space, is interpreted as a regular expression with
3325 path pattern syntax, except that tag patterns aren't left-anchored
3326 automatically (&my-app; doesn't silently add a <quote>^</quote>,
3327 you have to do it yourself if you need it).
3331 To match all requests that are tagged with <quote>foo</quote>
3332 your pattern line should be <quote>TAG:^foo$</quote>,
3333 <quote>TAG:foo</quote> would work as well, but it would also
3334 match requests whose tags contain <quote>foo</quote> somewhere.
3335 <quote>TAG: foo</quote> wouldn't work as it requires white space.
3339 Sections can contain URL and tag patterns at the same time,
3340 but tag patterns are checked after the URL patterns and thus
3341 always overrule them, even if they are located before the URL patterns.
3345 Once a new tag is added, Privoxy checks right away if it's matched by one
3346 of the tag patterns and updates the action settings accordingly. As a result
3347 tags can be used to activate other tagger actions, as long as these other
3348 taggers look for headers that haven't already be parsed.
3352 For example you could tag client requests which use the
3353 <literal>POST</literal> method,
3354 then use this tag to activate another tagger that adds a tag if cookies
3355 are sent, and then use a block action based on the cookie tag. This allows
3356 the outcome of one action, to be input into a subsequent action. However if
3357 you'd reverse the position of the described taggers, and activated the
3358 method tagger based on the cookie tagger, no method tags would be created.
3359 The method tagger would look for the request line, but at the time
3360 the cookie tag is created, the request line has already been parsed.
3364 While this is a limitation you should be aware of, this kind of
3365 indirection is seldom needed anyway and even the example doesn't
3366 make too much sense.
3373 <!-- ~ End section ~ -->
3376 <!-- ~~~~~ New section ~~~~~ -->
3378 <sect2 id="actions">
3379 <title>Actions</title>
3381 All actions are disabled by default, until they are explicitly enabled
3382 somewhere in an actions file. Actions are turned on if preceded with a
3383 <quote>+</quote>, and turned off if preceded with a <quote>-</quote>. So a
3384 <literal>+action</literal> means <quote>do that action</quote>, e.g.
3385 <literal>+block</literal> means <quote>please block URLs that match the
3386 following patterns</quote>, and <literal>-block</literal> means <quote>don't
3387 block URLs that match the following patterns, even if <literal>+block</literal>
3388 previously applied.</quote>
3393 Again, actions are invoked by placing them on a line, enclosed in curly braces and
3394 separated by whitespace, like in
3395 <literal>{+some-action -some-other-action{some-parameter}}</literal>,
3396 followed by a list of URL patterns, one per line, to which they apply.
3397 Together, the actions line and the following pattern lines make up a section
3398 of the actions file.
3402 Actions fall into three categories:
3409 Boolean, i.e the action can only be <quote>enabled</quote> or
3410 <quote>disabled</quote>. Syntax:
3414 +<replaceable class="function">name</replaceable> # enable action <replaceable class="parameter">name</replaceable>
3415 -<replaceable class="function">name</replaceable> # disable action <replaceable class="parameter">name</replaceable></screen>
3418 Example: <literal>+handle-as-image</literal>
3425 Parameterized, where some value is required in order to enable this type of action.
3430 +<replaceable class="function">name</replaceable>{<replaceable class="parameter">param</replaceable>} # enable action and set parameter to <replaceable class="parameter">param</replaceable>,
3431 # overwriting parameter from previous match if necessary
3432 -<replaceable class="function">name</replaceable> # disable action. The parameter can be omitted</screen>
3435 Note that if the URL matches multiple positive forms of a parameterized action,
3436 the last match wins, i.e. the params from earlier matches are simply ignored.
3439 Example: <literal>+hide-user-agent{Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.8.1.4) Gecko/20070602 Firefox/2.0.0.4}</literal>
3445 Multi-value. These look exactly like parameterized actions,
3446 but they behave differently: If the action applies multiple times to the
3447 same URL, but with different parameters, <emphasis>all</emphasis> the parameters
3448 from <emphasis>all</emphasis> matches are remembered. This is used for actions
3449 that can be executed for the same request repeatedly, like adding multiple
3450 headers, or filtering through multiple filters. Syntax:
3454 +<replaceable class="function">name</replaceable>{<replaceable class="parameter">param</replaceable>} # enable action and add <replaceable class="parameter">param</replaceable> to the list of parameters
3455 -<replaceable class="function">name</replaceable>{<replaceable class="parameter">param</replaceable>} # remove the parameter <replaceable class="parameter">param</replaceable> from the list of parameters
3456 # If it was the last one left, disable the action.
3457 <replaceable class="parameter">-name</replaceable> # disable this action completely and remove all parameters from the list</screen>
3460 Examples: <literal>+add-header{X-Fun-Header: Some text}</literal> and
3461 <literal>+filter{html-annoyances}</literal>
3469 If nothing is specified in any actions file, no <quote>actions</quote> are
3470 taken. So in this case <application>Privoxy</application> would just be a
3471 normal, non-blocking, non-filtering proxy. You must specifically enable the
3472 privacy and blocking features you need (although the provided default actions
3473 files will give a good starting point).
3477 Later defined action sections always over-ride earlier ones of the same type.
3478 So exceptions to any rules you make, should come in the latter part of the file (or
3479 in a file that is processed later when using multiple actions files such
3480 as <filename>user.action</filename>). For multi-valued actions, the actions
3481 are applied in the order they are specified. Actions files are processed in
3482 the order they are defined in <filename>config</filename> (the default
3483 installation has three actions files). It also quite possible for any given
3484 URL to match more than one <quote>pattern</quote> (because of wildcards and
3485 regular expressions), and thus to trigger more than one set of actions! Last
3489 <!-- start actions listing -->
3491 The list of valid <application>Privoxy</application> actions are:
3495 <!-- ********************************************************** -->
3496 <!-- Please note the below defined actions use id's that are -->
3497 <!-- probably linked from other places, so please don't change. -->
3499 <!-- ********************************************************** -->
3502 <!-- ~~~~~ New section ~~~~~ -->
3504 <sect3 renderas="sect4" id="add-header">
3505 <title>add-header</title>
3509 <term>Typical use:</term>
3511 <para>Confuse log analysis, custom applications</para>
3516 <term>Effect:</term>
3519 Sends a user defined HTTP header to the web server.
3526 <!-- boolean, parameterized, Multi-value -->
3528 <para>Multi-value.</para>
3533 <term>Parameter:</term>
3536 Any string value is possible. Validity of the defined HTTP headers is not checked.
3537 It is recommended that you use the <quote><literal>X-</literal></quote> prefix
3547 This action may be specified multiple times, in order to define multiple
3548 headers. This is rarely needed for the typical user. If you don't know what
3549 <quote>HTTP headers</quote> are, you definitely don't need to worry about this
3553 Headers added by this action are not modified by other actions.
3559 <term>Example usage:</term>
3562 <screen>+add-header{X-User-Tracking: sucks}</screen>
3570 <!-- ~~~~~ New section ~~~~~ -->
3571 <sect3 renderas="sect4" id="block">
3572 <title>block</title>
3576 <term>Typical use:</term>
3578 <para>Block ads or other unwanted content</para>
3583 <term>Effect:</term>
3586 Requests for URLs to which this action applies are blocked, i.e. the
3587 requests are trapped by &my-app; and the requested URL is never retrieved,
3588 but is answered locally with a substitute page or image, as determined by
3590 linkend="handle-as-image">handle-as-image</link></literal>,
3592 linkend="set-image-blocker">set-image-blocker</link></literal>, and
3594 linkend="handle-as-empty-document">handle-as-empty-document</link></literal> actions.
3602 <!-- boolean, parameterized, Multi-value -->
3604 <para>Parameterized.</para>
3609 <term>Parameter:</term>
3611 <para>A block reason that should be given to the user.</para>
3619 <application>Privoxy</application> sends a special <quote>BLOCKED</quote> page
3620 for requests to blocked pages. This page contains the block reason given as
3621 parameter, a link to find out why the block action applies, and a click-through
3622 to the blocked content (the latter only if the force feature is available and
3626 A very important exception occurs if <emphasis>both</emphasis>
3627 <literal>block</literal> and <literal><link linkend="handle-as-image">handle-as-image</link></literal>,
3628 apply to the same request: it will then be replaced by an image. If
3629 <literal><link linkend="set-image-blocker">set-image-blocker</link></literal>
3630 (see below) also applies, the type of image will be determined by its parameter,
3631 if not, the standard checkerboard pattern is sent.
3634 It is important to understand this process, in order
3635 to understand how <application>Privoxy</application> deals with
3636 ads and other unwanted content. Blocking is a core feature, and one
3637 upon which various other features depend.
3640 The <literal><link linkend="filter">filter</link></literal>
3641 action can perform a very similar task, by <quote>blocking</quote>
3642 banner images and other content through rewriting the relevant URLs in the
3643 document's HTML source, so they don't get requested in the first place.
3644 Note that this is a totally different technique, and it's easy to confuse the two.
3650 <term>Example usage (section):</term>
3653 <screen>{+block{No nasty stuff for you.}}
3654 # Block and replace with "blocked" page
3655 .nasty-stuff.example.com
3657 {+block{Doubleclick banners.} +handle-as-image}
3658 # Block and replace with image
3662 {+block{Layered ads.} +handle-as-empty-document}
3663 # Block and then ignore
3664 adserver.example.net/.*\.js$</screen>
3674 <!-- ~~~~~ New section ~~~~~ -->
3675 <sect3 renderas="sect4" id="change-x-forwarded-for">
3676 <title>change-x-forwarded-for</title>
3680 <term>Typical use:</term>
3682 <para>Improve privacy by not forwarding the source of the request in the HTTP headers.</para>
3687 <term>Effect:</term>
3690 Deletes the <quote>X-Forwarded-For:</quote> HTTP header from the client request,
3698 <!-- Boolean, Parameterized, Multi-value -->
3700 <para>Parameterized.</para>
3705 <term>Parameter:</term>
3709 <para><quote>block</quote> to delete the header.</para>
3713 <quote>add</quote> to create the header (or append
3714 the client's IP address to an already existing one).
3725 It is safe and recommended to use <literal>block</literal>.
3728 Forwarding the source address of the request may make
3729 sense in some multi-user setups but is also a privacy risk.
3734 <term>Example usage:</term>
3737 <screen>+change-x-forwarded-for{block}</screen>
3744 <!-- ~~~~~ New section ~~~~~ -->
3745 <sect3 renderas="sect4" id="client-header-filter">
3746 <title>client-header-filter</title>
3750 <term>Typical use:</term>
3753 Rewrite or remove single client headers.
3759 <term>Effect:</term>
3762 All client headers to which this action applies are filtered on-the-fly through
3763 the specified regular expression based substitutions.
3770 <!-- boolean, parameterized, Multi-value -->
3772 <para>Parameterized.</para>
3777 <term>Parameter:</term>
3780 The name of a client-header filter, as defined in one of the
3781 <link linkend="filter-file">filter files</link>.
3790 Client-header filters are applied to each header on its own, not to
3791 all at once. This makes it easier to diagnose problems, but on the downside
3792 you can't write filters that only change header x if header y's value is z.
3793 You can do that by using tags though.
3796 Client-header filters are executed after the other header actions have finished
3797 and use their output as input.
3800 If the request URI gets changed, &my-app; will detect that and use the new
3801 one. This can be used to rewrite the request destination behind the client's
3802 back, for example to specify a Tor exit relay for certain requests.
3805 Please refer to the <link linkend="filter-file">filter file chapter</link>
3806 to learn which client-header filters are available by default, and how to
3814 <term>Example usage (section):</term>
3818 # Hide Tor exit notation in Host and Referer Headers
3819 {+client-header-filter{hide-tor-exit-notation}}
3830 <!-- ~~~~~ New section ~~~~~ -->
3831 <sect3 renderas="sect4" id="client-header-tagger">
3832 <title>client-header-tagger</title>
3836 <term>Typical use:</term>
3839 Block requests based on their headers.
3845 <term>Effect:</term>
3848 Client headers to which this action applies are filtered on-the-fly through
3849 the specified regular expression based substitutions, the result is used as
3857 <!-- boolean, parameterized, Multi-value -->
3859 <para>Parameterized.</para>
3864 <term>Parameter:</term>
3867 The name of a client-header tagger, as defined in one of the
3868 <link linkend="filter-file">filter files</link>.
3877 Client-header taggers are applied to each header on its own,
3878 and as the header isn't modified, each tagger <quote>sees</quote>
3882 Client-header taggers are the first actions that are executed
3883 and their tags can be used to control every other action.
3889 <term>Example usage (section):</term>
3893 # Tag every request with the User-Agent header
3894 {+client-header-tagger{user-agent}}
3897 # Tagging itself doesn't change the action
3898 # settings, sections with TAG patterns do:
3900 # If it's a download agent, use a different forwarding proxy,
3901 # show the real User-Agent and make sure resume works.
3902 {+forward-override{forward-socks5 10.0.0.2:2222 .} \
3903 -hide-if-modified-since \
3904 -overwrite-last-modified \
3909 TAG:^User-Agent: NetBSD-ftp/
3910 TAG:^User-Agent: Novell ZYPP Installer
3911 TAG:^User-Agent: RPM APT-HTTP/
3912 TAG:^User-Agent: fetch libfetch/
3913 TAG:^User-Agent: Ubuntu APT-HTTP/
3914 TAG:^User-Agent: MPlayer/
3919 # Tag all requests with the Range header set
3920 {+client-header-tagger{range-requests}}
3923 # Disable filtering for the tagged requests.
3925 # With filtering enabled Privoxy would remove the Range headers
3926 # to be able to filter the whole response. The downside is that
3927 # it prevents clients from resuming downloads or skipping over
3928 # parts of multimedia files.
3929 {-filter -deanimate-gifs}
3940 <!-- ~~~~~ New section ~~~~~ -->
3941 <sect3 renderas="sect4" id="content-type-overwrite">
3942 <title>content-type-overwrite</title>
3946 <term>Typical use:</term>
3948 <para>Stop useless download menus from popping up, or change the browser's rendering mode</para>
3953 <term>Effect:</term>
3956 Replaces the <quote>Content-Type:</quote> HTTP server header.
3963 <!-- Boolean, Parameterized, Multi-value -->
3965 <para>Parameterized.</para>
3970 <term>Parameter:</term>
3982 The <quote>Content-Type:</quote> HTTP server header is used by the
3983 browser to decide what to do with the document. The value of this
3984 header can cause the browser to open a download menu instead of
3985 displaying the document by itself, even if the document's format is
3986 supported by the browser.
3989 The declared content type can also affect which rendering mode
3990 the browser chooses. If XHTML is delivered as <quote>text/html</quote>,
3991 many browsers treat it as yet another broken HTML document.
3992 If it is send as <quote>application/xml</quote>, browsers with
3993 XHTML support will only display it, if the syntax is correct.
3996 If you see a web site that proudly uses XHTML buttons, but sets
3997 <quote>Content-Type: text/html</quote>, you can use &my-app;
3998 to overwrite it with <quote>application/xml</quote> and validate
3999 the web master's claim inside your XHTML-supporting browser.
4000 If the syntax is incorrect, the browser will complain loudly.
4003 You can also go the opposite direction: if your browser prints
4004 error messages instead of rendering a document falsely declared
4005 as XHTML, you can overwrite the content type with
4006 <quote>text/html</quote> and have it rendered as broken HTML document.
4009 By default <literal>content-type-overwrite</literal> only replaces
4010 <quote>Content-Type:</quote> headers that look like some kind of text.
4011 If you want to overwrite it unconditionally, you have to combine it with
4012 <literal><link linkend="force-text-mode">force-text-mode</link></literal>.
4013 This limitation exists for a reason, think twice before circumventing it.
4016 Most of the time it's easier to replace this action with a custom
4017 <literal><link linkend="server-header-filter">server-header filter</link></literal>.
4018 It allows you to activate it for every document of a certain site and it will still
4019 only replace the content types you aimed at.
4022 Of course you can apply <literal>content-type-overwrite</literal>
4023 to a whole site and then make URL based exceptions, but it's a lot
4024 more work to get the same precision.
4030 <term>Example usage (sections):</term>
4033 <screen># Check if www.example.net/ really uses valid XHTML
4034 { +content-type-overwrite{application/xml} }
4037 # but leave the content type unmodified if the URL looks like a style sheet
4038 {-content-type-overwrite}
4039 www.example.net/.*\.css$
4040 www.example.net/.*style
4049 <!-- ~~~~~ New section ~~~~~ -->
4050 <sect3 renderas="sect4" id="crunch-client-header">
4054 <title>crunch-client-header</title>
4058 <term>Typical use:</term>
4060 <para>Remove a client header <application>Privoxy</application> has no dedicated action for.</para>
4065 <term>Effect:</term>
4068 Deletes every header sent by the client that contains the string the user supplied as parameter.
4075 <!-- Boolean, Parameterized, Multi-value -->
4077 <para>Parameterized.</para>
4082 <term>Parameter:</term>
4094 This action allows you to block client headers for which no dedicated
4095 <application>Privoxy</application> action exists.
4096 <application>Privoxy</application> will remove every client header that
4097 contains the string you supplied as parameter.
4100 Regular expressions are <emphasis>not supported</emphasis> and you can't
4101 use this action to block different headers in the same request, unless
4102 they contain the same string.
4105 <literal>crunch-client-header</literal> is only meant for quick tests.
4106 If you have to block several different headers, or only want to modify
4107 parts of them, you should use a
4108 <literal><link linkend="client-header-filter">client-header filter</link></literal>.
4112 Don't block any header without understanding the consequences.
4119 <term>Example usage (section):</term>
4122 <screen># Block the non-existent "Privacy-Violation:" client header
4123 { +crunch-client-header{Privacy-Violation:} }
4133 <!-- ~~~~~ New section ~~~~~ -->
4134 <sect3 renderas="sect4" id="crunch-if-none-match">
4135 <title>crunch-if-none-match</title>
4141 <term>Typical use:</term>
4143 <para>Prevent yet another way to track the user's steps between sessions.</para>
4148 <term>Effect:</term>
4151 Deletes the <quote>If-None-Match:</quote> HTTP client header.
4158 <!-- Boolean, Parameterized, Multi-value -->
4160 <para>Boolean.</para>
4165 <term>Parameter:</term>
4177 Removing the <quote>If-None-Match:</quote> HTTP client header
4178 is useful for filter testing, where you want to force a real
4179 reload instead of getting status code <quote>304</quote> which
4180 would cause the browser to use a cached copy of the page.
4183 It is also useful to make sure the header isn't used as a cookie
4184 replacement (unlikely but possible).
4187 Blocking the <quote>If-None-Match:</quote> header shouldn't cause any
4188 caching problems, as long as the <quote>If-Modified-Since:</quote> header
4189 isn't blocked or missing as well.
4192 It is recommended to use this action together with
4193 <literal><link linkend="hide-if-modified-since">hide-if-modified-since</link></literal>
4195 <literal><link linkend="overwrite-last-modified">overwrite-last-modified</link></literal>.
4201 <term>Example usage (section):</term>
4204 <screen># Let the browser revalidate cached documents but don't
4205 # allow the server to use the revalidation headers for user tracking.
4206 {+hide-if-modified-since{-60} \
4207 +overwrite-last-modified{randomize} \
4208 +crunch-if-none-match}
4217 <!-- ~~~~~ New section ~~~~~ -->
4218 <sect3 renderas="sect4" id="crunch-incoming-cookies">
4219 <title>crunch-incoming-cookies</title>
4223 <term>Typical use:</term>
4226 Prevent the web server from setting HTTP cookies on your system
4232 <term>Effect:</term>
4235 Deletes any <quote>Set-Cookie:</quote> HTTP headers from server replies.
4242 <!-- Boolean, Parameterized, Multi-value -->
4244 <para>Boolean.</para>
4249 <term>Parameter:</term>
4261 This action is only concerned with <emphasis>incoming</emphasis> HTTP cookies. For
4262 <emphasis>outgoing</emphasis> HTTP cookies, use
4263 <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal>.
4264 Use <emphasis>both</emphasis> to disable HTTP cookies completely.
4267 It makes <emphasis>no sense at all</emphasis> to use this action in conjunction
4268 with the <literal><link linkend="session-cookies-only">session-cookies-only</link></literal> action,
4269 since it would prevent the session cookies from being set. See also
4270 <literal><link linkend="filter-content-cookies">filter-content-cookies</link></literal>.
4276 <term>Example usage:</term>
4279 <screen>+crunch-incoming-cookies</screen>
4287 <!-- ~~~~~ New section ~~~~~ -->
4288 <sect3 renderas="sect4" id="crunch-server-header">
4289 <title>crunch-server-header</title>
4295 <term>Typical use:</term>
4297 <para>Remove a server header <application>Privoxy</application> has no dedicated action for.</para>
4302 <term>Effect:</term>
4305 Deletes every header sent by the server that contains the string the user supplied as parameter.
4312 <!-- Boolean, Parameterized, Multi-value -->
4314 <para>Parameterized.</para>
4319 <term>Parameter:</term>
4331 This action allows you to block server headers for which no dedicated
4332 <application>Privoxy</application> action exists. <application>Privoxy</application>
4333 will remove every server header that contains the string you supplied as parameter.
4336 Regular expressions are <emphasis>not supported</emphasis> and you can't
4337 use this action to block different headers in the same request, unless
4338 they contain the same string.
4341 <literal>crunch-server-header</literal> is only meant for quick tests.
4342 If you have to block several different headers, or only want to modify
4343 parts of them, you should use a custom
4344 <literal><link linkend="server-header-filter">server-header filter</link></literal>.
4348 Don't block any header without understanding the consequences.
4355 <term>Example usage (section):</term>
4358 <screen># Crunch server headers that try to prevent caching
4359 { +crunch-server-header{no-cache} }
4368 <!-- ~~~~~ New section ~~~~~ -->
4369 <sect3 renderas="sect4" id="crunch-outgoing-cookies">
4370 <title>crunch-outgoing-cookies</title>
4374 <term>Typical use:</term>
4377 Prevent the web server from reading any HTTP cookies from your system
4383 <term>Effect:</term>
4386 Deletes any <quote>Cookie:</quote> HTTP headers from client requests.
4393 <!-- Boolean, Parameterized, Multi-value -->
4395 <para>Boolean.</para>
4400 <term>Parameter:</term>
4412 This action is only concerned with <emphasis>outgoing</emphasis> HTTP cookies. For
4413 <emphasis>incoming</emphasis> HTTP cookies, use
4414 <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal>.
4415 Use <emphasis>both</emphasis> to disable HTTP cookies completely.
4418 It makes <emphasis>no sense at all</emphasis> to use this action in conjunction
4419 with the <literal><link linkend="session-cookies-only">session-cookies-only</link></literal> action,
4420 since it would prevent the session cookies from being read.
4426 <term>Example usage:</term>
4429 <screen>+crunch-outgoing-cookies</screen>
4438 <!-- ~~~~~ New section ~~~~~ -->
4439 <sect3 renderas="sect4" id="deanimate-gifs">
4440 <title>deanimate-gifs</title>
4444 <term>Typical use:</term>
4446 <para>Stop those annoying, distracting animated GIF images.</para>
4451 <term>Effect:</term>
4454 De-animate GIF animations, i.e. reduce them to their first or last image.
4461 <!-- boolean, parameterized, Multi-value -->
4463 <para>Parameterized.</para>
4468 <term>Parameter:</term>
4471 <quote>last</quote> or <quote>first</quote>
4480 This will also shrink the images considerably (in bytes, not pixels!). If
4481 the option <quote>first</quote> is given, the first frame of the animation
4482 is used as the replacement. If <quote>last</quote> is given, the last
4483 frame of the animation is used instead, which probably makes more sense for
4484 most banner animations, but also has the risk of not showing the entire
4485 last frame (if it is only a delta to an earlier frame).
4488 You can safely use this action with patterns that will also match non-GIF
4489 objects, because no attempt will be made at anything that doesn't look like
4496 <term>Example usage:</term>
4499 <screen>+deanimate-gifs{last}</screen>
4506 <!-- ~~~~~ New section ~~~~~ -->
4507 <sect3 renderas="sect4" id="downgrade-http-version">
4508 <title>downgrade-http-version</title>
4512 <term>Typical use:</term>
4514 <para>Work around (very rare) problems with HTTP/1.1</para>
4519 <term>Effect:</term>
4522 Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0.
4529 <!-- boolean, parameterized, Multi-value -->
4531 <para>Boolean.</para>
4536 <term>Parameter:</term>
4548 This is a left-over from the time when <application>Privoxy</application>
4549 didn't support important HTTP/1.1 features well. It is left here for the
4550 unlikely case that you experience HTTP/1.1-related problems with some server
4554 Note that enabling this action is only a workaround. It should not
4555 be enabled for sites that work without it. While it shouldn't break
4556 any pages, it has an (usually negative) performance impact.
4559 If you come across a site where enabling this action helps, please report it,
4560 so the cause of the problem can be analyzed. If the problem turns out to be
4561 caused by a bug in <application>Privoxy</application> it should be
4562 fixed so the following release works without the work around.
4568 <term>Example usage (section):</term>
4571 <screen>{+downgrade-http-version}
4572 problem-host.example.com</screen>
4580 <!-- ~~~~~ New section ~~~~~ -->
4581 <sect3 renderas="sect4" id="fast-redirects">
4582 <title>fast-redirects</title>
4586 <term>Typical use:</term>
4588 <para>Fool some click-tracking scripts and speed up indirect links.</para>
4593 <term>Effect:</term>
4596 Detects redirection URLs and redirects the browser without contacting
4597 the redirection server first.
4604 <!-- boolean, parameterized, Multi-value -->
4606 <para>Parameterized.</para>
4611 <term>Parameter:</term>
4616 <quote>simple-check</quote> to just search for the string <quote>http://</quote>
4617 to detect redirection URLs.
4622 <quote>check-decoded-url</quote> to decode URLs (if necessary) before searching
4623 for redirection URLs.
4634 Many sites, like yahoo.com, don't just link to other sites. Instead, they
4635 will link to some script on their own servers, giving the destination as a
4636 parameter, which will then redirect you to the final target. URLs
4637 resulting from this scheme typically look like:
4638 <quote>http://www.example.org/click-tracker.cgi?target=http%3a//www.example.net/</quote>.
4641 Sometimes, there are even multiple consecutive redirects encoded in the
4642 URL. These redirections via scripts make your web browsing more traceable,
4643 since the server from which you follow such a link can see where you go
4644 to. Apart from that, valuable bandwidth and time is wasted, while your
4645 browser asks the server for one redirect after the other. Plus, it feeds
4649 This feature is currently not very smart and is scheduled for improvement.
4650 If it is enabled by default, you will have to create some exceptions to
4651 this action. It can lead to failures in several ways:
4654 Not every URLs with other URLs as parameters is evil.
4655 Some sites offer a real service that requires this information to work.
4656 For example a validation service needs to know, which document to validate.
4657 <literal>fast-redirects</literal> assumes that every URL parameter that
4658 looks like another URL is a redirection target, and will always redirect to
4659 the last one. Most of the time the assumption is correct, but if it isn't,
4660 the user gets redirected anyway.
4663 Another failure occurs if the URL contains other parameters after the URL parameter.
4665 <quote>http://www.example.org/?redirect=http%3a//www.example.net/&foo=bar</quote>.
4666 contains the redirection URL <quote>http://www.example.net/</quote>,
4667 followed by another parameter. <literal>fast-redirects</literal> doesn't know that
4668 and will cause a redirect to <quote>http://www.example.net/&foo=bar</quote>.
4669 Depending on the target server configuration, the parameter will be silently ignored
4670 or lead to a <quote>page not found</quote> error. You can prevent this problem by
4671 first using the <literal><link linkend="redirect">redirect</link></literal> action
4672 to remove the last part of the URL, but it requires a little effort.
4675 To detect a redirection URL, <literal>fast-redirects</literal> only
4676 looks for the string <quote>http://</quote>, either in plain text
4677 (invalid but often used) or encoded as <quote>http%3a//</quote>.
4678 Some sites use their own URL encoding scheme, encrypt the address
4679 of the target server or replace it with a database id. In theses cases
4680 <literal>fast-redirects</literal> is fooled and the request reaches the
4681 redirection server where it probably gets logged.
4687 <term>Example usage:</term>
4691 { +fast-redirects{simple-check} }
4694 { +fast-redirects{check-decoded-url} }
4695 another.example.com/testing</screen>
4704 <!-- ~~~~~ New section ~~~~~ -->
4705 <sect3 renderas="sect4" id="filter">
4706 <title>filter</title>
4710 <term>Typical use:</term>
4712 <para>Get rid of HTML and JavaScript annoyances, banner advertisements (by size),
4713 do fun text replacements, add personalized effects, etc.</para>
4718 <term>Effect:</term>
4721 All instances of text-based type, most notably HTML and JavaScript, to which
4722 this action applies, can be filtered on-the-fly through the specified regular
4723 expression based substitutions. (Note: as of version 3.0.3 plain text documents
4724 are exempted from filtering, because web servers often use the
4725 <literal>text/plain</literal> MIME type for all files whose type they don't know.)
4732 <!-- boolean, parameterized, Multi-value -->
4734 <para>Parameterized.</para>
4739 <term>Parameter:</term>
4742 The name of a content filter, as defined in the <link linkend="filter-file">filter file</link>.
4743 Filters can be defined in one or more files as defined by the
4744 <literal><link linkend="filterfile">filterfile</link></literal>
4745 option in the <link linkend="config">config file</link>.
4746 <filename>default.filter</filename> is the collection of filters
4747 supplied by the developers. Locally defined filters should go
4748 in their own file, such as <filename>user.filter</filename>.
4751 When used in its negative form,
4752 and without parameters, <emphasis>all</emphasis> filtering is completely disabled.
4761 For your convenience, there are a number of pre-defined filters available
4762 in the distribution filter file that you can use. See the examples below for
4766 Filtering requires buffering the page content, which may appear to
4767 slow down page rendering since nothing is displayed until all content has
4768 passed the filters. (The total time until the page is completely rendered
4769 doesn't change much, but it may be perceived as slower since the page is
4770 not incrementally displayed.)
4771 This effect will be more noticeable on slower connections.
4774 <quote>Rolling your own</quote>
4775 filters requires a knowledge of
4776 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
4777 Expressions</quote></ulink> and
4778 <ulink url="http://en.wikipedia.org/wiki/Html"><quote>HTML</quote></ulink>.
4779 This is very powerful feature, and potentially very intrusive.
4780 Filters should be used with caution, and where an equivalent
4781 <quote>action</quote> is not available.
4784 The amount of data that can be filtered is limited to the
4785 <literal><link linkend="buffer-limit">buffer-limit</link></literal>
4786 option in the main <link linkend="config">config file</link>. The
4787 default is 4096 KB (4 Megs). Once this limit is exceeded, the buffered
4788 data, and all pending data, is passed through unfiltered.
4791 Inappropriate MIME types, such as zipped files, are not filtered at all.
4792 (Again, only text-based types except plain text). Encrypted SSL data
4793 (from HTTPS servers) cannot be filtered either, since this would violate
4794 the integrity of the secure transaction. In some situations it might
4795 be necessary to protect certain text, like source code, from filtering
4796 by defining appropriate <literal>-filter</literal> exceptions.
4799 Compressed content can't be filtered either, but if &my-app;
4800 is compiled with zlib support and a supported compression algorithm
4801 is used (gzip or deflate), &my-app; can first decompress the content
4805 If you use a &my-app; version without zlib support, but want filtering to work on
4806 as much documents as possible, even those that would normally be sent compressed,
4807 you must use the <literal><link linkend="prevent-compression">prevent-compression</link></literal>
4808 action in conjunction with <literal>filter</literal>.
4811 Content filtering can achieve some of the same effects as the
4812 <literal><link linkend="block">block</link></literal>
4813 action, i.e. it can be used to block ads and banners. But the mechanism
4814 works quite differently. One effective use, is to block ad banners
4815 based on their size (see below), since many of these seem to be somewhat
4819 <link linkend="contact">Feedback</link> with suggestions for new or
4820 improved filters is particularly welcome!
4823 The below list has only the names and a one-line description of each
4824 predefined filter. There are <link linkend="predefined-filters">more
4825 verbose explanations</link> of what these filters do in the <link
4826 linkend="filter-file">filter file chapter</link>.
4832 <term>Example usage (with filters from the distribution <filename>default.filter</filename> file).
4833 See <link linkend="PREDEFINED-FILTERS">the Predefined Filters section</link> for
4834 more explanation on each:</term>
4837 <anchor id="filter-js-annoyances">
4838 <screen>+filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse.</screen>
4841 <anchor id="filter-js-events">
4842 <screen>+filter{js-events} # Kill all JS event bindings and timers (Radically destructive! Only for extra nasty sites).</screen>
4845 <anchor id="filter-html-annoyances">
4846 <screen>+filter{html-annoyances} # Get rid of particularly annoying HTML abuse.</screen>
4849 <anchor id="filter-content-cookies">
4850 <screen>+filter{content-cookies} # Kill cookies that come in the HTML or JS content.</screen>
4853 <anchor id="filter-refresh-tags">
4854 <screen>+filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups).</screen>
4857 <anchor id="filter-unsolicited-popups">
4858 <screen>+filter{unsolicited-popups} # Disable only unsolicited pop-up windows. Useful if your browser lacks this ability.</screen>
4861 <anchor id="filter-all-popups">
4862 <screen>+filter{all-popups} # Kill all popups in JavaScript and HTML. Useful if your browser lacks this ability.</screen>
4865 <anchor id="filter-img-reorder">
4866 <screen>+filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective.</screen>
4869 <anchor id="filter-banners-by-size">
4870 <screen>+filter{banners-by-size} # Kill banners by size.</screen>
4873 <anchor id="filter-banners-by-link">
4874 <screen>+filter{banners-by-link} # Kill banners by their links to known clicktrackers.</screen>
4877 <anchor id="filter-webbugs">
4878 <screen>+filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking).</screen>
4881 <anchor id="filter-tiny-textforms">
4882 <screen>+filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap.</screen>
4885 <anchor id="filter-jumping-windows">
4886 <screen>+filter{jumping-windows} # Prevent windows from resizing and moving themselves.</screen>
4889 <anchor id="filter-frameset-borders">
4890 <screen>+filter{frameset-borders} # Give frames a border and make them resizable.</screen>
4893 <anchor id="filter-demoronizer">
4894 <screen>+filter{demoronizer} # Fix MS's non-standard use of standard charsets.</screen>
4897 <anchor id="filter-shockwave-flash">
4898 <screen>+filter{shockwave-flash} # Kill embedded Shockwave Flash objects.</screen>
4901 <anchor id="filter-quicktime-kioskmode">
4902 <screen>+filter{quicktime-kioskmode} # Make Quicktime movies saveable.</screen>
4905 <anchor id="filter-fun">
4906 <screen>+filter{fun} # Text replacements for subversive browsing fun!</screen>
4909 <anchor id="filter-crude-parental">
4910 <screen>+filter{crude-parental} # Crude parental filtering. Note that this filter doesn't work reliably.</screen>
4913 <anchor id="filter-ie-exploits">
4914 <screen>+filter{ie-exploits} # Disable some known Internet Explorer bug exploits.</screen>
4917 <anchor id="filter-site-specifics">
4918 <screen>+filter{site-specifics} # Cure for site-specific problems. Don't apply generally!</screen>
4921 <anchor id="filter-no-ping">
4922 <screen>+filter{no-ping} # Removes non-standard ping attributes in <a> and <area> tags.</screen>
4925 <anchor id="filter-google">
4926 <screen>+filter{google} # CSS-based block for Google text ads. Also removes a width limitation and the toolbar advertisement.</screen>
4929 <anchor id="filter-yahoo">
4930 <screen>+filter{yahoo} # CSS-based block for Yahoo text ads. Also removes a width limitation.</screen>
4933 <anchor id="filter-msn">
4934 <screen>+filter{msn} # CSS-based block for MSN text ads. Also removes tracking URLs and a width limitation.</screen>
4937 <anchor id="filter-blogspot">
4938 <screen>+filter{blogspot} # Cleans up some Blogspot blogs. Read the fine print before using this.</screen>
4946 <!-- ~~~~~ New section ~~~~~ -->
4947 <sect3 renderas="sect4" id="force-text-mode">
4948 <title>force-text-mode</title>
4954 <term>Typical use:</term>
4956 <para>Force <application>Privoxy</application> to treat a document as if it was in some kind of <emphasis>text</emphasis> format. </para>
4961 <term>Effect:</term>
4964 Declares a document as text, even if the <quote>Content-Type:</quote> isn't detected as such.
4971 <!-- Boolean, Parameterized, Multi-value -->
4973 <para>Boolean.</para>
4978 <term>Parameter:</term>
4990 As explained <literal><link linkend="filter">above</link></literal>,
4991 <application>Privoxy</application> tries to only filter files that are
4992 in some kind of text format. The same restrictions apply to
4993 <literal><link linkend="content-type-overwrite">content-type-overwrite</link></literal>.
4994 <literal>force-text-mode</literal> declares a document as text,
4995 without looking at the <quote>Content-Type:</quote> first.
4999 Think twice before activating this action. Filtering binary data
5000 with regular expressions can cause file damage.
5007 <term>Example usage:</term>
5020 <!-- ~~~~~ New section ~~~~~ -->
5021 <sect3 renderas="sect4" id="forward-override">
5022 <title>forward-override</title>
5028 <term>Typical use:</term>
5030 <para>Change the forwarding settings based on User-Agent or request origin</para>
5035 <term>Effect:</term>
5038 Overrules the forward directives in the configuration file.
5045 <!-- Boolean, Parameterized, Multi-value -->
5047 <para>Multi-value.</para>
5052 <term>Parameter:</term>
5056 <para><quote>forward .</quote> to use a direct connection without any additional proxies.</para>
5060 <quote>forward 127.0.0.1:8123</quote> to use the HTTP proxy listening at 127.0.0.1 port 8123.
5065 <quote>forward-socks4a 127.0.0.1:9050 .</quote> to use the socks4a proxy listening at
5066 127.0.0.1 port 9050. Replace <quote>forward-socks4a</quote> with <quote>forward-socks4</quote>
5067 to use a socks4 connection (with local DNS resolution) instead, use <quote>forward-socks5</quote>
5068 for socks5 connections (with remote DNS resolution).
5073 <quote>forward-socks4a 127.0.0.1:9050 proxy.example.org:8000</quote> to use the socks4a proxy
5074 listening at 127.0.0.1 port 9050 to reach the HTTP proxy listening at proxy.example.org port 8000.
5075 Replace <quote>forward-socks4a</quote> with <quote>forward-socks4</quote> to use a socks4 connection
5076 (with local DNS resolution) instead, use <quote>forward-socks5</quote>
5077 for socks5 connections (with remote DNS resolution).
5088 This action takes parameters similar to the
5089 <link linkend="forwarding">forward</link> directives in the configuration
5090 file, but without the URL pattern. It can be used as replacement, but normally it's only
5091 used in cases where matching based on the request URL isn't sufficient.
5095 Please read the description for the <link linkend="forwarding">forward</link> directives before
5096 using this action. Forwarding to the wrong people will reduce your privacy and increase the
5097 chances of man-in-the-middle attacks.
5100 If the ports are missing or invalid, default values will be used. This might change
5101 in the future and you shouldn't rely on it. Otherwise incorrect syntax causes Privoxy
5105 Use the <ulink url="http://config.privoxy.org/show-url-info">show-url-info CGI page</ulink>
5106 to verify that your forward settings do what you thought the do.
5113 <term>Example usage:</term>
5117 # Always use direct connections for requests previously tagged as
5118 # <quote>User-Agent: fetch libfetch/2.0</quote> and make sure
5119 # resuming downloads continues to work.
5120 # This way you can continue to use Tor for your normal browsing,
5121 # without overloading the Tor network with your FreeBSD ports updates
5122 # or downloads of bigger files like ISOs.
5123 # Note that HTTP headers are easy to fake and therefore their
5124 # values are as (un)trustworthy as your clients and users.
5125 {+forward-override{forward .} \
5126 -hide-if-modified-since \
5127 -overwrite-last-modified \
5129 TAG:^User-Agent: fetch libfetch/2\.0$
5138 <!-- ~~~~~ New section ~~~~~ -->
5139 <sect3 renderas="sect4" id="handle-as-empty-document">
5140 <title>handle-as-empty-document</title>
5146 <term>Typical use:</term>
5148 <para>Mark URLs that should be replaced by empty documents <emphasis>if they get blocked</emphasis></para>
5153 <term>Effect:</term>
5156 This action alone doesn't do anything noticeable. It just marks URLs.
5157 If the <literal><link linkend="block">block</link></literal> action <emphasis>also applies</emphasis>,
5158 the presence or absence of this mark decides whether an HTML <quote>BLOCKED</quote>
5159 page, or an empty document will be sent to the client as a substitute for the blocked content.
5160 The <emphasis>empty</emphasis> document isn't literally empty, but actually contains a single space.
5167 <!-- Boolean, Parameterized, Multi-value -->
5169 <para>Boolean.</para>
5174 <term>Parameter:</term>
5186 Some browsers complain about syntax errors if JavaScript documents
5187 are blocked with <application>Privoxy's</application>
5188 default HTML page; this option can be used to silence them.
5189 And of course this action can also be used to eliminate the &my-app;
5190 BLOCKED message in frames.
5193 The content type for the empty document can be specified with
5194 <literal><link linkend="content-type-overwrite">content-type-overwrite{}</link></literal>,
5195 but usually this isn't necessary.
5201 <term>Example usage:</term>
5204 <screen># Block all documents on example.org that end with ".js",
5205 # but send an empty document instead of the usual HTML message.
5206 {+block{Blocked JavaScript} +handle-as-empty-document}
5216 <!-- ~~~~~ New section ~~~~~ -->
5217 <sect3 renderas="sect4" id="handle-as-image">
5218 <title>handle-as-image</title>
5222 <term>Typical use:</term>
5224 <para>Mark URLs as belonging to images (so they'll be replaced by images <emphasis>if they do get blocked</emphasis>, rather than HTML pages)</para>
5229 <term>Effect:</term>
5232 This action alone doesn't do anything noticeable. It just marks URLs as images.
5233 If the <literal><link linkend="block">block</link></literal> action <emphasis>also applies</emphasis>,
5234 the presence or absence of this mark decides whether an HTML <quote>blocked</quote>
5235 page, or a replacement image (as determined by the <literal><link
5236 linkend="set-image-blocker">set-image-blocker</link></literal> action) will be sent to the
5237 client as a substitute for the blocked content.
5244 <!-- Boolean, Parameterized, Multi-value -->
5246 <para>Boolean.</para>
5251 <term>Parameter:</term>
5263 The below generic example section is actually part of <filename>default.action</filename>.
5264 It marks all URLs with well-known image file name extensions as images and should
5268 Users will probably only want to use the handle-as-image action in conjunction with
5269 <literal><link linkend="block">block</link></literal>, to block sources of banners, whose URLs don't
5270 reflect the file type, like in the second example section.
5273 Note that you cannot treat HTML pages as images in most cases. For instance, (in-line) ad
5274 frames require an HTML page to be sent, or they won't display properly.
5275 Forcing <literal>handle-as-image</literal> in this situation will not replace the
5276 ad frame with an image, but lead to error messages.
5282 <term>Example usage (sections):</term>
5285 <screen># Generic image extensions:
5288 /.*\.(gif|jpg|jpeg|png|bmp|ico)$
5290 # These don't look like images, but they're banners and should be
5291 # blocked as images:
5293 {+block{Nasty banners.} +handle-as-image}
5294 nasty-banner-server.example.com/junk.cgi\?output=trash
5303 <!-- ~~~~~ New section ~~~~~ -->
5304 <sect3 renderas="sect4" id="hide-accept-language">
5305 <title>hide-accept-language</title>
5311 <term>Typical use:</term>
5313 <para>Pretend to use different language settings.</para>
5318 <term>Effect:</term>
5321 Deletes or replaces the <quote>Accept-Language:</quote> HTTP header in client requests.
5328 <!-- Boolean, Parameterized, Multi-value -->
5330 <para>Parameterized.</para>
5335 <term>Parameter:</term>
5338 Keyword: <quote>block</quote>, or any user defined value.
5347 Faking the browser's language settings can be useful to make a
5348 foreign User-Agent set with
5349 <literal><link linkend="hide-user-agent">hide-user-agent</link></literal>
5353 However some sites with content in different languages check the
5354 <quote>Accept-Language:</quote> to decide which one to take by default.
5355 Sometimes it isn't possible to later switch to another language without
5356 changing the <quote>Accept-Language:</quote> header first.
5359 Therefore it's a good idea to either only change the
5360 <quote>Accept-Language:</quote> header to languages you understand,
5361 or to languages that aren't wide spread.
5364 Before setting the <quote>Accept-Language:</quote> header
5365 to a rare language, you should consider that it helps to
5366 make your requests unique and thus easier to trace.
5367 If you don't plan to change this header frequently,
5368 you should stick to a common language.
5374 <term>Example usage (section):</term>
5377 <screen># Pretend to use Canadian language settings.
5378 {+hide-accept-language{en-ca} \
5379 +hide-user-agent{Mozilla/5.0 (X11; U; OpenBSD i386; en-CA; rv:1.8.0.4) Gecko/20060628 Firefox/1.5.0.4} \
5389 <!-- ~~~~~ New section ~~~~~ -->
5390 <sect3 renderas="sect4" id="hide-content-disposition">
5391 <title>hide-content-disposition</title>
5397 <term>Typical use:</term>
5399 <para>Prevent download menus for content you prefer to view inside the browser.</para>
5404 <term>Effect:</term>
5407 Deletes or replaces the <quote>Content-Disposition:</quote> HTTP header set by some servers.
5414 <!-- Boolean, Parameterized, Multi-value -->
5416 <para>Parameterized.</para>
5421 <term>Parameter:</term>
5424 Keyword: <quote>block</quote>, or any user defined value.
5433 Some servers set the <quote>Content-Disposition:</quote> HTTP header for
5434 documents they assume you want to save locally before viewing them.
5435 The <quote>Content-Disposition:</quote> header contains the file name
5436 the browser is supposed to use by default.
5439 In most browsers that understand this header, it makes it impossible to
5440 <emphasis>just view</emphasis> the document, without downloading it first,
5441 even if it's just a simple text file or an image.
5444 Removing the <quote>Content-Disposition:</quote> header helps
5445 to prevent this annoyance, but some browsers additionally check the
5446 <quote>Content-Type:</quote> header, before they decide if they can
5447 display a document without saving it first. In these cases, you have
5448 to change this header as well, before the browser stops displaying
5452 It is also possible to change the server's file name suggestion
5453 to another one, but in most cases it isn't worth the time to set
5457 This action will probably be removed in the future,
5458 use server-header filters instead.
5464 <term>Example usage:</term>
5467 <screen># Disarm the download link in Sourceforge's patch tracker
5469 +content-type-overwrite{text/plain}\
5470 +hide-content-disposition{block} }
5471 .sourceforge.net/tracker/download\.php</screen>
5479 <!-- ~~~~~ New section ~~~~~ -->
5480 <sect3 renderas="sect4" id="hide-if-modified-since">
5481 <title>hide-if-modified-since</title>
5487 <term>Typical use:</term>
5489 <para>Prevent yet another way to track the user's steps between sessions.</para>
5494 <term>Effect:</term>
5497 Deletes the <quote>If-Modified-Since:</quote> HTTP client header or modifies its value.
5504 <!-- Boolean, Parameterized, Multi-value -->
5506 <para>Parameterized.</para>
5511 <term>Parameter:</term>
5514 Keyword: <quote>block</quote>, or a user defined value that specifies a range of hours.
5523 Removing this header is useful for filter testing, where you want to force a real
5524 reload instead of getting status code <quote>304</quote>, which would cause the
5525 browser to use a cached copy of the page.
5528 Instead of removing the header, <literal>hide-if-modified-since</literal> can
5529 also add or subtract a random amount of time to/from the header's value.
5530 You specify a range of minutes where the random factor should be chosen from and
5531 <application>Privoxy</application> does the rest. A negative value means
5532 subtracting, a positive value adding.
5535 Randomizing the value of the <quote>If-Modified-Since:</quote> makes
5536 it less likely that the server can use the time as a cookie replacement,
5537 but you will run into caching problems if the random range is too high.
5540 It is a good idea to only use a small negative value and let
5541 <literal><link linkend="overwrite-last-modified">overwrite-last-modified</link></literal>
5542 handle the greater changes.
5545 It is also recommended to use this action together with
5546 <literal><link linkend="crunch-if-none-match">crunch-if-none-match</link></literal>,
5547 otherwise it's more or less pointless.
5553 <term>Example usage (section):</term>
5556 <screen># Let the browser revalidate but make tracking based on the time less likely.
5557 {+hide-if-modified-since{-60} \
5558 +overwrite-last-modified{randomize} \
5559 +crunch-if-none-match}
5568 <!-- ~~~~~ New section ~~~~~ -->
5569 <sect3 renderas="sect4" id="hide-from-header">
5570 <title>hide-from-header</title>
5574 <term>Typical use:</term>
5576 <para>Keep your (old and ill) browser from telling web servers your email address</para>
5581 <term>Effect:</term>
5584 Deletes any existing <quote>From:</quote> HTTP header, or replaces it with the
5592 <!-- Boolean, Parameterized, Multi-value -->
5594 <para>Parameterized.</para>
5599 <term>Parameter:</term>
5602 Keyword: <quote>block</quote>, or any user defined value.
5611 The keyword <quote>block</quote> will completely remove the header
5612 (not to be confused with the <literal><link linkend="block">block</link></literal>
5616 Alternately, you can specify any value you prefer to be sent to the web
5617 server. If you do, it is a matter of fairness not to use any address that
5618 is actually used by a real person.
5621 This action is rarely needed, as modern web browsers don't send
5622 <quote>From:</quote> headers anymore.
5628 <term>Example usage:</term>
5631 <screen>+hide-from-header{block}</screen> or
5632 <screen>+hide-from-header{spam-me-senseless@sittingduck.example.com}</screen>
5640 <!-- ~~~~~ New section ~~~~~ -->
5641 <sect3 renderas="sect4" id="hide-referrer">
5642 <title>hide-referrer</title>
5643 <anchor id="hide-referer">
5646 <term>Typical use:</term>
5648 <para>Conceal which link you followed to get to a particular site</para>
5653 <term>Effect:</term>
5656 Deletes the <quote>Referer:</quote> (sic) HTTP header from the client request,
5657 or replaces it with a forged one.
5664 <!-- Boolean, Parameterized, Multi-value -->
5666 <para>Parameterized.</para>
5671 <term>Parameter:</term>
5675 <para><quote>conditional-block</quote> to delete the header completely if the host has changed.</para>
5678 <para><quote>conditional-forge</quote> to forge the header if the host has changed.</para>
5681 <para><quote>block</quote> to delete the header unconditionally.</para>
5684 <para><quote>forge</quote> to pretend to be coming from the homepage of the server we are talking to.</para>
5687 <para>Any other string to set a user defined referrer.</para>
5697 <literal>conditional-block</literal> is the only parameter,
5698 that isn't easily detected in the server's log file. If it blocks the
5699 referrer, the request will look like the visitor used a bookmark or
5700 typed in the address directly.
5703 Leaving the referrer unmodified for requests on the same host
5704 allows the server owner to see the visitor's <quote>click path</quote>,
5705 but in most cases she could also get that information by comparing
5706 other parts of the log file: for example the User-Agent if it isn't
5707 a very common one, or the user's IP address if it doesn't change between
5711 Always blocking the referrer, or using a custom one, can lead to
5712 failures on servers that check the referrer before they answer any
5713 requests, in an attempt to prevent their content from being
5714 embedded or linked to elsewhere.
5717 Both <literal>conditional-block</literal> and <literal>forge</literal>
5718 will work with referrer checks, as long as content and valid referring page
5719 are on the same host. Most of the time that's the case.
5722 <literal>hide-referer</literal> is an alternate spelling of
5723 <literal>hide-referrer</literal> and the two can be can be freely
5724 substituted with each other. (<quote>referrer</quote> is the
5725 correct English spelling, however the HTTP specification has a bug - it
5726 requires it to be spelled as <quote>referer</quote>.)
5732 <term>Example usage:</term>
5735 <screen>+hide-referrer{forge}</screen> or
5736 <screen>+hide-referrer{http://www.yahoo.com/}</screen>
5744 <!-- ~~~~~ New section ~~~~~ -->
5745 <sect3 renderas="sect4" id="hide-user-agent">
5746 <title>hide-user-agent</title>
5750 <term>Typical use:</term>
5752 <para>Try to conceal your type of browser and client operating system</para>
5757 <term>Effect:</term>
5760 Replaces the value of the <quote>User-Agent:</quote> HTTP header
5761 in client requests with the specified value.
5768 <!-- Boolean, Parameterized, Multi-value -->
5770 <para>Parameterized.</para>
5775 <term>Parameter:</term>
5778 Any user-defined string.
5788 This can lead to problems on web sites that depend on looking at this header in
5789 order to customize their content for different browsers (which, by the
5790 way, is <emphasis>NOT</emphasis> the right thing to do: good web sites
5791 work browser-independently).
5795 Using this action in multi-user setups or wherever different types of
5796 browsers will access the same <application>Privoxy</application> is
5797 <emphasis>not recommended</emphasis>. In single-user, single-browser
5798 setups, you might use it to delete your OS version information from
5799 the headers, because it is an invitation to exploit known bugs for your
5800 OS. It is also occasionally useful to forge this in order to access
5801 sites that won't let you in otherwise (though there may be a good
5802 reason in some cases).
5805 More information on known user-agent strings can be found at
5806 <ulink url="http://www.user-agents.org/">http://www.user-agents.org/</ulink>
5808 <ulink url="http://en.wikipedia.org/wiki/User_agent">http://en.wikipedia.org/wiki/User_agent</ulink>.
5814 <term>Example usage:</term>
5817 <screen>+hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}</screen>
5825 <!-- ~~~~~ New section ~~~~~ -->
5826 <sect3 renderas="sect4" id="limit-connect">
5827 <title>limit-connect</title>
5831 <term>Typical use:</term>
5833 <para>Prevent abuse of <application>Privoxy</application> as a TCP proxy relay or disable SSL for untrusted sites</para>
5838 <term>Effect:</term>
5841 Specifies to which ports HTTP CONNECT requests are allowable.
5848 <!-- Boolean, Parameterized, Multi-value -->
5850 <para>Parameterized.</para>
5855 <term>Parameter:</term>
5858 A comma-separated list of ports or port ranges (the latter using dashes, with the minimum
5859 defaulting to 0 and the maximum to 65K).
5868 By default, i.e. if no <literal>limit-connect</literal> action applies,
5869 <application>Privoxy</application> allows HTTP CONNECT requests to all
5870 ports. Use <literal>limit-connect</literal> if fine-grained control
5871 is desired for some or all destinations.
5874 The CONNECT methods exists in HTTP to allow access to secure websites
5875 (<quote>https://</quote> URLs) through proxies. It works very simply:
5876 the proxy connects to the server on the specified port, and then
5877 short-circuits its connections to the client and to the remote server.
5878 This means CONNECT-enabled proxies can be used as TCP relays very easily.
5881 <application>Privoxy</application> relays HTTPS traffic without seeing
5882 the decoded content. Websites can leverage this limitation to circumvent &my-app;'s
5883 filters. By specifying an invalid port range you can disable HTTPS entirely.
5889 <term>Example usages:</term>
5891 <!-- I had trouble getting the spacing to look right in my browser -->
5892 <!-- I probably have the wrong font setup, bollocks. -->
5893 <!-- Apparently the emphasis tag uses a proportional font no matter what -->
5895 <screen>+limit-connect{443} # Port 443 is OK.
5896 +limit-connect{80,443} # Ports 80 and 443 are OK.
5897 +limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
5898 +limit-connect{-} # All ports are OK
5899 +limit-connect{,} # No HTTPS/SSL traffic is allowed</screen>
5907 <!-- ~~~~~ New section ~~~~~ -->
5908 <sect3 renderas="sect4" id="limit-cookie-lifetime">
5909 <title>limit-cookie-lifetime</title>
5913 <term>Typical use:</term>
5915 <para>Limit the lifetime of HTTP cookies to a couple of minutes or hours.</para>
5920 <term>Effect:</term>
5923 Overwrites the expires field in Set-Cookie server headers if it's above the specified limit.
5930 <!-- Boolean, Parameterized, Multi-value -->
5932 <para>Parameterized.</para>
5937 <term>Parameter:</term>
5940 The lifetime limit in minutes, or 0.
5949 This action reduces the lifetime of HTTP cookies coming from the
5950 server to the specified number of minutes, starting from the time
5951 the cookie passes Privoxy.
5954 Cookies with a lifetime below the limit are not modified.
5955 The lifetime of session cookies is set to the specified limit.
5958 The effect of this action depends on the server.
5961 In case of servers which refresh their cookies with each response
5962 (or at least frequently), the lifetime limit set by this action
5964 Thus, a session associated with the cookie continues to work with
5965 this action enabled, as long as a new request is made before the
5966 last limit set is reached.
5969 However, some servers send their cookies once, with a lifetime of several
5970 years (the year 2037 is a popular choice), and do not refresh them
5971 until a certain event in the future, for example the user logging out.
5972 In this case this action may limit the absolute lifetime of the session,
5973 even if requests are made frequently.
5976 If the parameter is <quote>0</quote>, this action behaves like
5977 <literal><link linkend="session-cookies-only">session-cookies-only</link></literal>.
5983 <term>Example usages:</term>
5986 <screen>+limit-cookie-lifetime{60}
5994 <!-- ~~~~~ New section ~~~~~ -->
5995 <sect3 renderas="sect4" id="prevent-compression">
5996 <title>prevent-compression</title>
6000 <term>Typical use:</term>
6003 Ensure that servers send the content uncompressed, so it can be
6004 passed through <literal><link linkend="filter">filter</link></literal>s.
6010 <term>Effect:</term>
6013 Removes the Accept-Encoding header which can be used to ask for compressed transfer.
6020 <!-- Boolean, Parameterized, Multi-value -->
6022 <para>Boolean.</para>
6027 <term>Parameter:</term>
6039 More and more websites send their content compressed by default, which
6040 is generally a good idea and saves bandwidth. But the <literal><link
6041 linkend="filter">filter</link></literal> and
6042 <literal><link linkend="deanimate-gifs">deanimate-gifs</link></literal>
6043 actions need access to the uncompressed data.
6046 When compiled with zlib support (available since &my-app; 3.0.7), content that should be
6047 filtered is decompressed on-the-fly and you don't have to worry about this action.
6048 If you are using an older &my-app; version, or one that hasn't been compiled with zlib
6049 support, this action can be used to convince the server to send the content uncompressed.
6052 Most text-based instances compress very well, the size is seldom decreased by less than 50%,
6053 for markup-heavy instances like news feeds saving more than 90% of the original size isn't
6057 Not using compression will therefore slow down the transfer, and you should only
6058 enable this action if you really need it. As of &my-app; 3.0.7 it's disabled in all
6059 predefined action settings.
6062 Note that some (rare) ill-configured sites don't handle requests for uncompressed
6063 documents correctly. Broken PHP applications tend to send an empty document body,
6064 some IIS versions only send the beginning of the content. If you enable
6065 <literal>prevent-compression</literal> per default, you might want to add
6066 exceptions for those sites. See the example for how to do that.
6072 <term>Example usage (sections):</term>
6076 # Selectively turn off compression, and enable a filter
6078 { +filter{tiny-textforms} +prevent-compression }
6079 # Match only these sites
6084 # Or instead, we could set a universal default:
6086 { +prevent-compression }
6089 # Then maybe make exceptions for broken sites:
6091 { -prevent-compression }
6092 .compusa.com/</screen>
6101 <!-- ~~~~~ New section ~~~~~ -->
6102 <sect3 renderas="sect4" id="overwrite-last-modified">
6103 <title>overwrite-last-modified</title>
6109 <term>Typical use:</term>
6111 <para>Prevent yet another way to track the user's steps between sessions.</para>
6116 <term>Effect:</term>
6119 Deletes the <quote>Last-Modified:</quote> HTTP server header or modifies its value.
6126 <!-- Boolean, Parameterized, Multi-value -->
6128 <para>Parameterized.</para>
6133 <term>Parameter:</term>
6136 One of the keywords: <quote>block</quote>, <quote>reset-to-request-time</quote>
6137 and <quote>randomize</quote>
6146 Removing the <quote>Last-Modified:</quote> header is useful for filter
6147 testing, where you want to force a real reload instead of getting status
6148 code <quote>304</quote>, which would cause the browser to reuse the old
6149 version of the page.
6152 The <quote>randomize</quote> option overwrites the value of the
6153 <quote>Last-Modified:</quote> header with a randomly chosen time
6154 between the original value and the current time. In theory the server
6155 could send each document with a different <quote>Last-Modified:</quote>
6156 header to track visits without using cookies. <quote>Randomize</quote>
6157 makes it impossible and the browser can still revalidate cached documents.
6160 <quote>reset-to-request-time</quote> overwrites the value of the
6161 <quote>Last-Modified:</quote> header with the current time. You could use
6162 this option together with
6163 <literal><link linkend="hide-if-modified-since">hide-if-modified-since</link></literal>
6164 to further customize your random range.
6167 The preferred parameter here is <quote>randomize</quote>. It is safe
6168 to use, as long as the time settings are more or less correct.
6169 If the server sets the <quote>Last-Modified:</quote> header to the time
6170 of the request, the random range becomes zero and the value stays the same.
6171 Therefore you should later randomize it a second time with
6172 <literal><link linkend="hide-if-modified-since">hided-if-modified-since</link></literal>,
6176 It is also recommended to use this action together with
6177 <literal><link linkend="crunch-if-none-match">crunch-if-none-match</link></literal>.
6183 <term>Example usage:</term>
6186 <screen># Let the browser revalidate without being tracked across sessions
6187 { +hide-if-modified-since{-60} \
6188 +overwrite-last-modified{randomize} \
6189 +crunch-if-none-match}
6198 <!-- ~~~~~ New section ~~~~~ -->
6199 <sect3 renderas="sect4" id="redirect">
6200 <title>redirect</title>
6206 <term>Typical use:</term>
6209 Redirect requests to other sites.
6215 <term>Effect:</term>
6218 Convinces the browser that the requested document has been moved
6219 to another location and the browser should get it from there.
6226 <!-- Boolean, Parameterized, Multi-value -->
6228 <para>Parameterized</para>
6233 <term>Parameter:</term>
6236 An absolute URL or a single pcrs command.
6245 Requests to which this action applies are answered with a
6246 HTTP redirect to URLs of your choosing. The new URL is
6247 either provided as parameter, or derived by applying a
6248 single pcrs command to the original URL.
6251 The syntax for pcrs commands is documented in the
6252 <link linkend="filter-file">filter file</link> section.
6255 This action will be ignored if you use it together with
6256 <literal><link linkend="block">block</link></literal>.
6257 It can be combined with
6258 <literal><link linkend="fast-redirects">fast-redirects{check-decoded-url}</link></literal>
6259 to redirect to a decoded version of a rewritten URL.
6262 Use this action carefully, make sure not to create redirection loops
6263 and be aware that using your own redirects might make it
6264 possible to fingerprint your requests.
6267 In case of problems with your redirects, or simply to watch
6268 them working, enable <link linkend="DEBUG">debug 128</link>.
6274 <term>Example usages:</term>
6277 <screen># Replace example.com's style sheet with another one
6278 { +redirect{http://localhost/css-replacements/example.com.css} }
6279 example.com/stylesheet\.css
6281 # Create a short, easy to remember nickname for a favorite site
6282 # (relies on the browser accept and forward invalid URLs to &my-app;)
6283 { +redirect{http://www.privoxy.org/user-manual/actions-file.html} }
6286 # Always use the expanded view for Undeadly.org articles
6287 # (Note the $ at the end of the URL pattern to make sure
6288 # the request for the rewritten URL isn't redirected as well)
6289 {+redirect{s@$@&mode=expanded@}}
6290 undeadly.org/cgi\?action=article&sid=\d*$
6292 # Redirect Google search requests to MSN
6293 {+redirect{s@^http://[^/]*/search\?q=([^&]*).*@http://search.msn.com/results.aspx?q=$1@}}
6296 # Redirect MSN search requests to Yahoo
6297 {+redirect{s@^http://[^/]*/results\.aspx\?q=([^&]*).*@http://search.yahoo.com/search?p=$1@}}
6298 search.msn.com//results\.aspx\?q=
6300 # Redirect remote requests for this manual
6301 # to the local version delivered by Privoxy
6302 {+redirect{s@^http://www@http://config@}}
6303 www.privoxy.org/user-manual/</screen>
6312 <!-- ~~~~~ New section ~~~~~ -->
6313 <sect3 renderas="sect4" id="server-header-filter">
6314 <title>server-header-filter</title>
6318 <term>Typical use:</term>
6321 Rewrite or remove single server headers.
6327 <term>Effect:</term>
6330 All server headers to which this action applies are filtered on-the-fly
6331 through the specified regular expression based substitutions.
6338 <!-- boolean, parameterized, Multi-value -->
6340 <para>Parameterized.</para>
6345 <term>Parameter:</term>
6348 The name of a server-header filter, as defined in one of the
6349 <link linkend="filter-file">filter files</link>.
6358 Server-header filters are applied to each header on its own, not to
6359 all at once. This makes it easier to diagnose problems, but on the downside
6360 you can't write filters that only change header x if header y's value is z.
6361 You can do that by using tags though.
6364 Server-header filters are executed after the other header actions have finished
6365 and use their output as input.
6368 Please refer to the <link linkend="filter-file">filter file chapter</link>
6369 to learn which server-header filters are available by default, and how to
6376 <term>Example usage (section):</term>
6380 {+server-header-filter{html-to-xml}}
6381 example.org/xml-instance-that-is-delivered-as-html
6383 {+server-header-filter{xml-to-html}}
6384 example.org/instance-that-is-delivered-as-xml-but-is-not
6394 <!-- ~~~~~ New section ~~~~~ -->
6395 <sect3 renderas="sect4" id="server-header-tagger">
6396 <title>server-header-tagger</title>
6400 <term>Typical use:</term>
6403 Enable or disable filters based on the Content-Type header.
6409 <term>Effect:</term>
6412 Server headers to which this action applies are filtered on-the-fly through
6413 the specified regular expression based substitutions, the result is used as
6421 <!-- boolean, parameterized, Multi-value -->
6423 <para>Parameterized.</para>
6428 <term>Parameter:</term>
6431 The name of a server-header tagger, as defined in one of the
6432 <link linkend="filter-file">filter files</link>.
6441 Server-header taggers are applied to each header on its own,
6442 and as the header isn't modified, each tagger <quote>sees</quote>
6446 Server-header taggers are executed before all other header actions
6447 that modify server headers. Their tags can be used to control
6448 all of the other server-header actions, the content filters
6449 and the crunch actions (<link linkend="redirect">redirect</link>
6450 and <link linkend="block">block</link>).
6453 Obviously crunching based on tags created by server-header taggers
6454 doesn't prevent the request from showing up in the server's log file.
6461 <term>Example usage (section):</term>
6465 # Tag every request with the content type declared by the server
6466 {+server-header-tagger{content-type}}
6477 <!-- ~~~~~ New section ~~~~~ -->
6478 <sect3 renderas="sect4" id="session-cookies-only">
6479 <title>session-cookies-only</title>
6483 <term>Typical use:</term>
6486 Allow only temporary <quote>session</quote> cookies (for the current
6487 browser session <emphasis>only</emphasis>).
6493 <term>Effect:</term>
6496 Deletes the <quote>expires</quote> field from <quote>Set-Cookie:</quote>
6497 server headers. Most browsers will not store such cookies permanently and
6498 forget them in between sessions.
6505 <!-- Boolean, Parameterized, Multi-value -->
6507 <para>Boolean.</para>
6512 <term>Parameter:</term>
6524 This is less strict than <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal> /
6525 <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal> and allows you to browse
6526 websites that insist or rely on setting cookies, without compromising your privacy too badly.
6529 Most browsers will not permanently store cookies that have been processed by
6530 <literal>session-cookies-only</literal> and will forget about them between sessions.
6531 This makes profiling cookies useless, but won't break sites which require cookies so
6532 that you can log in for transactions. This is generally turned on for all
6533 sites, and is the recommended setting.
6536 It makes <emphasis>no sense at all</emphasis> to use <literal>session-cookies-only</literal>
6537 together with <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal> or
6538 <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal>. If you do, cookies
6539 will be plainly killed.
6542 Note that it is up to the browser how it handles such cookies without an <quote>expires</quote>
6543 field. If you use an exotic browser, you might want to try it out to be sure.
6546 This setting also has no effect on cookies that may have been stored
6547 previously by the browser before starting <application>Privoxy</application>.
6548 These would have to be removed manually.
6551 <application>Privoxy</application> also uses
6552 the <link linkend="filter-content-cookies">content-cookies filter</link>
6553 to block some types of cookies. Content cookies are not effected by
6554 <literal>session-cookies-only</literal>.
6560 <term>Example usage:</term>
6563 <screen>+session-cookies-only</screen>
6571 <!-- ~~~~~ New section ~~~~~ -->
6572 <sect3 renderas="sect4" id="set-image-blocker">
6573 <title>set-image-blocker</title>
6577 <term>Typical use:</term>
6579 <para>Choose the replacement for blocked images</para>
6584 <term>Effect:</term>
6587 This action alone doesn't do anything noticeable. If <emphasis>both</emphasis>
6588 <literal><link linkend="block">block</link></literal> <emphasis>and</emphasis> <literal><link
6589 linkend="handle-as-image">handle-as-image</link></literal> <emphasis>also</emphasis>
6590 apply, i.e. if the request is to be blocked as an image,
6591 <emphasis>then</emphasis> the parameter of this action decides what will be
6592 sent as a replacement.
6599 <!-- Boolean, Parameterized, Multi-value -->
6601 <para>Parameterized.</para>
6606 <term>Parameter:</term>
6611 <quote>pattern</quote> to send a built-in checkerboard pattern image. The image is visually
6612 decent, scales very well, and makes it obvious where banners were busted.
6617 <quote>blank</quote> to send a built-in transparent image. This makes banners disappear
6618 completely, but makes it hard to detect where <application>Privoxy</application> has blocked
6619 images on a given page and complicates troubleshooting if <application>Privoxy</application>
6620 has blocked innocent images, like navigation icons.
6625 <quote><replaceable class="parameter">target-url</replaceable></quote> to
6626 send a redirect to <replaceable class="parameter">target-url</replaceable>. You can redirect
6627 to any image anywhere, even in your local filesystem via <quote>file:///</quote> URL.
6628 (But note that not all browsers support redirecting to a local file system).
6631 A good application of redirects is to use special <application>Privoxy</application>-built-in
6632 URLs, which send the built-in images, as <replaceable class="parameter">target-url</replaceable>.
6633 This has the same visual effect as specifying <quote>blank</quote> or <quote>pattern</quote> in
6634 the first place, but enables your browser to cache the replacement image, instead of requesting
6635 it over and over again.
6646 The URLs for the built-in images are <quote>http://config.privoxy.org/send-banner?type=<replaceable
6647 class="parameter">type</replaceable></quote>, where <replaceable class="parameter">type</replaceable> is
6648 either <quote>blank</quote> or <quote>pattern</quote>.
6651 There is a third (advanced) type, called <quote>auto</quote>. It is <emphasis>NOT</emphasis> to be
6652 used in <literal>set-image-blocker</literal>, but meant for use from <link linkend="filter-file">filters</link>.
6653 Auto will select the type of image that would have applied to the referring page, had it been an image.
6659 <term>Example usage:</term>
6665 <screen>+set-image-blocker{pattern}</screen>
6668 Redirect to the BSD daemon:
6671 <screen>+set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}</screen>
6674 Redirect to the built-in pattern for better caching:
6677 <screen>+set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}</screen>
6685 <!-- ~~~~~ New section ~~~~~ -->
6687 <title>Summary</title>
6689 Note that many of these actions have the potential to cause a page to
6690 misbehave, possibly even not to display at all. There are many ways
6691 a site designer may choose to design his site, and what HTTP header
6692 content, and other criteria, he may depend on. There is no way to have hard
6693 and fast rules for all sites. See the <link
6694 linkend="ACTIONSANAT">Appendix</link> for a brief example on troubleshooting
6700 <!-- ~~~~~ New section ~~~~~ -->
6701 <sect2 id="aliases">
6702 <title>Aliases</title>
6704 Custom <quote>actions</quote>, known to <application>Privoxy</application>
6705 as <quote>aliases</quote>, can be defined by combining other actions.
6706 These can in turn be invoked just like the built-in actions.
6707 Currently, an alias name can contain any character except space, tab,
6709 <quote>{</quote> and <quote>}</quote>, but we <emphasis>strongly
6710 recommend</emphasis> that you only use <quote>a</quote> to <quote>z</quote>,
6711 <quote>0</quote> to <quote>9</quote>, <quote>+</quote>, and <quote>-</quote>.
6712 Alias names are not case sensitive, and are not required to start with a
6713 <quote>+</quote> or <quote>-</quote> sign, since they are merely textually
6717 Aliases can be used throughout the actions file, but they <emphasis>must be
6718 defined in a special section at the top of the file!</emphasis>
6719 And there can only be one such section per actions file. Each actions file may
6720 have its own alias section, and the aliases defined in it are only visible
6724 There are two main reasons to use aliases: One is to save typing for frequently
6725 used combinations of actions, the other one is a gain in flexibility: If you
6726 decide once how you want to handle shops by defining an alias called
6727 <quote>shop</quote>, you can later change your policy on shops in
6728 <emphasis>one</emphasis> place, and your changes will take effect everywhere
6729 in the actions file where the <quote>shop</quote> alias is used. Calling aliases
6730 by their purpose also makes your actions files more readable.
6733 Currently, there is one big drawback to using aliases, though:
6734 <application>Privoxy</application>'s built-in web-based action file
6735 editor honors aliases when reading the actions files, but it expands
6736 them before writing. So the effects of your aliases are of course preserved,
6737 but the aliases themselves are lost when you edit sections that use aliases
6742 Now let's define some aliases...
6747 # Useful custom aliases we can use later.
6749 # Note the (required!) section header line and that this section
6750 # must be at the top of the actions file!
6754 # These aliases just save typing later:
6755 # (Note that some already use other aliases!)
6757 +crunch-all-cookies = +<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> +<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
6758 -crunch-all-cookies = -<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> -<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
6759 +block-as-image = +block{Blocked image.} +handle-as-image
6760 allow-all-cookies = -crunch-all-cookies -<link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> -<link linkend="FILTER-CONTENT-COOKIES">filter{content-cookies}</link>
6762 # These aliases define combinations of actions
6763 # that are useful for certain types of sites:
6765 fragile = -<link linkend="BLOCK">block</link> -<link linkend="FILTER">filter</link> -crunch-all-cookies -<link linkend="FAST-REDIRECTS">fast-redirects</link> -<link linkend="HIDE-REFERER">hide-referrer</link> -<link linkend="PREVENT-COMPRESSION">prevent-compression</link>
6767 shop = -crunch-all-cookies -<link linkend="FILTER-ALL-POPUPS">filter{all-popups}</link>
6769 # Short names for other aliases, for really lazy people ;-)
6771 c0 = +crunch-all-cookies
6772 c1 = -crunch-all-cookies</screen>
6776 ...and put them to use. These sections would appear in the lower part of an
6777 actions file and define exceptions to the default actions (as specified further
6778 up for the <quote>/</quote> pattern):
6783 # These sites are either very complex or very keen on
6784 # user data and require minimal interference to work:
6787 .office.microsoft.com
6788 .windowsupdate.microsoft.com
6789 # Gmail is really mail.google.com, not gmail.com
6793 # Allow cookies (for setting and retrieving your customer data)
6797 .worldpay.com # for quietpc.com
6800 # These shops require pop-ups:
6802 {-filter{all-popups} -filter{unsolicited-popups}}
6804 .overclockers.co.uk</screen>
6808 Aliases like <quote>shop</quote> and <quote>fragile</quote> are typically used for
6809 <quote>problem</quote> sites that require more than one action to be disabled
6810 in order to function properly.
6816 <!-- ~~~~~ New section ~~~~~ -->
6817 <sect2 id="act-examples">
6818 <title>Actions Files Tutorial</title>
6820 The above chapters have shown <link linkend="actions-file">which actions files
6821 there are and how they are organized</link>, how actions are <link
6822 linkend="actions">specified</link> and <link linkend="actions-apply">applied
6823 to URLs</link>, how <link linkend="af-patterns">patterns</link> work, and how to
6824 define and use <link linkend="aliases">aliases</link>. Now, let's look at an
6825 example <filename>match-all.action</filename>, <filename>default.action</filename>
6826 and <filename>user.action</filename> file and see how all these pieces come together:
6830 <title>match-all.action</title>
6832 Remember <emphasis>all actions are disabled when matching starts</emphasis>,
6833 so we have to explicitly enable the ones we want.
6837 While the <filename>match-all.action</filename> file only contains a
6838 single section, it is probably the most important one. It has only one
6839 pattern, <quote><literal>/</literal></quote>, but this pattern
6840 <link linkend="af-patterns">matches all URLs</link>. Therefore, the set of
6841 actions used in this <quote>default</quote> section <emphasis>will
6842 be applied to all requests as a start</emphasis>. It can be partly or
6843 wholly overridden by other actions files like <filename>default.action</filename>
6844 and <filename>user.action</filename>, but it will still be largely responsible
6845 for your overall browsing experience.
6849 Again, at the start of matching, all actions are disabled, so there is
6850 no need to disable any actions here. (Remember: a <quote>+</quote>
6851 preceding the action name enables the action, a <quote>-</quote> disables!).
6852 Also note how this long line has been made more readable by splitting it into
6853 multiple lines with line continuation.
6859 +<link linkend="CHANGE-X-FORWARDED-FOR">change-x-forwarded-for{block}</link> \
6860 +<link linkend="HIDE-FROM-HEADER">hide-from-header{block}</link> \
6861 +<link linkend="SET-IMAGE-BLOCKER">set-image-blocker{pattern}</link> \
6868 The default behavior is now set.
6873 <title>default.action</title>
6876 If you aren't a developer, there's no need for you to edit the
6877 <filename>default.action</filename> file. It is maintained by
6878 the &my-app; developers and if you disagree with some of the
6879 sections, you should overrule them in your <filename>user.action</filename>.
6883 Understanding the <filename>default.action</filename> file can
6884 help you with your <filename>user.action</filename>, though.
6888 The first section in this file is a special section for internal use
6889 that prevents older &my-app; versions from reading the file:
6894 ##########################################################################
6895 # Settings -- Don't change! For internal Privoxy use ONLY.
6896 ##########################################################################
6898 for-privoxy-version=3.0.11</screen>
6902 After that comes the (optional) alias section. We'll use the example
6903 section from the above <link linkend="aliases">chapter on aliases</link>,
6904 that also explains why and how aliases are used:
6909 ##########################################################################
6911 ##########################################################################
6914 # These aliases just save typing later:
6915 # (Note that some already use other aliases!)
6917 +crunch-all-cookies = +<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> +<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
6918 -crunch-all-cookies = -<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> -<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
6919 +block-as-image = +block{Blocked image.} +handle-as-image
6920 mercy-for-cookies = -crunch-all-cookies -<link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> -<link linkend="FILTER-CONTENT-COOKIES">filter{content-cookies}</link>
6922 # These aliases define combinations of actions
6923 # that are useful for certain types of sites:
6925 fragile = -<link linkend="BLOCK">block</link> -<link linkend="FILTER">filter</link> -crunch-all-cookies -<link linkend="FAST-REDIRECTS">fast-redirects</link> -<link linkend="HIDE-REFERER">hide-referrer</link>
6926 shop = -crunch-all-cookies -<link linkend="FILTER-ALL-POPUPS">filter{all-popups}</link></screen>
6930 The first of our specialized sections is concerned with <quote>fragile</quote>
6931 sites, i.e. sites that require minimum interference, because they are either
6932 very complex or very keen on tracking you (and have mechanisms in place that
6933 make them unusable for people who avoid being tracked). We will simply use
6934 our pre-defined <literal>fragile</literal> alias instead of stating the list
6935 of actions explicitly:
6940 ##########################################################################
6941 # Exceptions for sites that'll break under the default action set:
6942 ##########################################################################
6944 # "Fragile" Use a minimum set of actions for these sites (see alias above):
6947 .office.microsoft.com # surprise, surprise!
6948 .windowsupdate.microsoft.com
6949 mail.google.com</screen>
6953 Shopping sites are not as fragile, but they typically
6954 require cookies to log in, and pop-up windows for shopping
6955 carts or item details. Again, we'll use a pre-defined alias:
6964 .worldpay.com # for quietpc.com
6966 .scan.co.uk</screen>
6970 The <literal><link linkend="FAST-REDIRECTS">fast-redirects</link></literal>
6971 action, which may have been enabled in <filename>match-all.action</filename>,
6972 breaks some sites. So disable it for popular sites where we know it misbehaves:
6977 { -<link linkend="FAST-REDIRECTS">fast-redirects</link> }
6981 .altavista.com/.*(like|url|link):http
6982 .altavista.com/trans.*urltext=http
6983 .nytimes.com</screen>
6987 It is important that <application>Privoxy</application> knows which
6988 URLs belong to images, so that <emphasis>if</emphasis> they are to
6989 be blocked, a substitute image can be sent, rather than an HTML page.
6990 Contacting the remote site to find out is not an option, since it
6991 would destroy the loading time advantage of banner blocking, and it
6992 would feed the advertisers information about you. We can mark any
6993 URL as an image with the <literal><link
6994 linkend="handle-as-image">handle-as-image</link></literal> action,
6995 and marking all URLs that end in a known image file extension is a
7001 ##########################################################################
7003 ##########################################################################
7005 # Define which file types will be treated as images, in case they get
7006 # blocked further down this file:
7008 { +<link linkend="HANDLE-AS-IMAGE">handle-as-image</link> }
7009 /.*\.(gif|jpe?g|png|bmp|ico)$</screen>
7013 And then there are known banner sources. They often use scripts to
7014 generate the banners, so it won't be visible from the URL that the
7015 request is for an image. Hence we block them <emphasis>and</emphasis>
7016 mark them as images in one go, with the help of our
7017 <literal>+block-as-image</literal> alias defined above. (We could of
7018 course just as well use <literal>+<link linkend="block">block</link>
7019 +<link linkend="handle-as-image">handle-as-image</link></literal> here.)
7020 Remember that the type of the replacement image is chosen by the
7021 <literal><link linkend="set-image-blocker">set-image-blocker</link></literal>
7022 action. Since all URLs have matched the default section with its
7023 <literal>+<link linkend="set-image-blocker">set-image-blocker</link>{pattern}</literal>
7024 action before, it still applies and needn't be repeated:
7029 # Known ad generators:
7034 .ad.*.doubleclick.net
7035 .a.yimg.com/(?:(?!/i/).)*$
7036 .a[0-9].yimg.com/(?:(?!/i/).)*$
7042 One of the most important jobs of <application>Privoxy</application>
7043 is to block banners. Many of these can be <quote>blocked</quote>
7044 by the <literal><link linkend="filter">filter</link>{banners-by-size}</literal>
7045 action, which we enabled above, and which deletes the references to banner
7046 images from the pages while they are loaded, so the browser doesn't request
7047 them anymore, and hence they don't need to be blocked here. But this naturally
7048 doesn't catch all banners, and some people choose not to use filters, so we
7049 need a comprehensive list of patterns for banner URLs here, and apply the
7050 <literal><link linkend="block">block</link></literal> action to them.
7053 First comes many generic patterns, which do most of the work, by
7054 matching typical domain and path name components of banners. Then comes
7055 a list of individual patterns for specific sites, which is omitted here
7056 to keep the example short:
7061 ##########################################################################
7062 # Block these fine banners:
7063 ##########################################################################
7064 { <link linkend="BLOCK">+block{Banner ads.}</link> }
7072 /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
7073 /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
7075 # Site-specific patterns (abbreviated):
7077 .hitbox.com</screen>
7081 It's quite remarkable how many advertisers actually call their banner
7082 servers ads.<replaceable>company</replaceable>.com, or call the directory
7083 in which the banners are stored simply <quote>banners</quote>. So the above
7084 generic patterns are surprisingly effective.
7087 But being very generic, they necessarily also catch URLs that we don't want
7088 to block. The pattern <literal>.*ads.</literal> e.g. catches
7089 <quote>nasty-<emphasis>ads</emphasis>.nasty-corp.com</quote> as intended,
7090 but also <quote>downlo<emphasis>ads</emphasis>.sourcefroge.net</quote> or
7091 <quote><emphasis>ads</emphasis>l.some-provider.net.</quote> So here come some
7092 well-known exceptions to the <literal>+<link linkend="BLOCK">block</link></literal>
7096 Note that these are exceptions to exceptions from the default! Consider the URL
7097 <quote>downloads.sourcefroge.net</quote>: Initially, all actions are deactivated,
7098 so it wouldn't get blocked. Then comes the defaults section, which matches the
7099 URL, but just deactivates the <literal><link linkend="BLOCK">block</link></literal>
7100 action once again. Then it matches <literal>.*ads.</literal>, an exception to the
7101 general non-blocking policy, and suddenly
7102 <literal><link linkend="BLOCK">+block</link></literal> applies. And now, it'll match
7103 <literal>.*loads.</literal>, where <literal><link linkend="BLOCK">-block</link></literal>
7104 applies, so (unless it matches <emphasis>again</emphasis> further down) it ends up
7105 with no <literal><link linkend="BLOCK">block</link></literal> action applying.
7110 ##########################################################################
7111 # Save some innocent victims of the above generic block patterns:
7112 ##########################################################################
7116 { -<link linkend="BLOCK">block</link> }
7117 adv[io]*. # (for advogato.org and advice.*)
7118 adsl. # (has nothing to do with ads)
7119 adobe. # (has nothing to do with ads either)
7120 ad[ud]*. # (adult.* and add.*)
7121 .edu # (universities don't host banners (yet!))
7122 .*loads. # (downloads, uploads etc)
7130 www.globalintersec.com/adv # (adv = advanced)
7131 www.ugu.com/sui/ugu/adv</screen>
7135 Filtering source code can have nasty side effects,
7136 so make an exception for our friends at sourceforge.net,
7137 and all paths with <quote>cvs</quote> in them. Note that
7138 <literal>-<link linkend="FILTER">filter</link></literal>
7139 disables <emphasis>all</emphasis> filters in one fell swoop!
7144 # Don't filter code!
7146 { -<link linkend="FILTER">filter</link> }
7151 .sourceforge.net</screen>
7155 The actual <filename>default.action</filename> is of course much more
7156 comprehensive, but we hope this example made clear how it works.
7161 <sect3><title>user.action</title>
7164 So far we are painting with a broad brush by setting general policies,
7165 which would be a reasonable starting point for many people. Now,
7166 you might want to be more specific and have customized rules that
7167 are more suitable to your personal habits and preferences. These would
7168 be for narrowly defined situations like your ISP or your bank, and should
7169 be placed in <filename>user.action</filename>, which is parsed after all other
7170 actions files and hence has the last word, over-riding any previously
7171 defined actions. <filename>user.action</filename> is also a
7172 <emphasis>safe</emphasis> place for your personal settings, since
7173 <filename>default.action</filename> is actively maintained by the
7174 <application>Privoxy</application> developers and you'll probably want
7175 to install updated versions from time to time.
7179 So let's look at a few examples of things that one might typically do in
7180 <filename>user.action</filename>:
7184 <!-- brief sample user.action here -->
7188 # My user.action file. <fred@example.com></screen>
7192 As <link linkend="aliases">aliases</link> are local to the actions
7193 file that they are defined in, you can't use the ones from
7194 <filename>default.action</filename>, unless you repeat them here:
7199 # Aliases are local to the file they are defined in.
7200 # (Re-)define aliases for this file:
7204 # These aliases just save typing later, and the alias names should
7205 # be self explanatory.
7207 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
7208 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
7209 allow-all-cookies = -crunch-all-cookies -session-cookies-only
7210 allow-popups = -filter{all-popups}
7211 +block-as-image = +block{Blocked as image.} +handle-as-image
7212 -block-as-image = -block
7214 # These aliases define combinations of actions that are useful for
7215 # certain types of sites:
7217 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referrer
7218 shop = -crunch-all-cookies allow-popups
7220 # Allow ads for selected useful free sites:
7222 allow-ads = -block -filter{banners-by-size} -filter{banners-by-link}
7224 # Alias for specific file types that are text, but might have conflicting
7225 # MIME types. We want the browser to force these to be text documents.
7226 handle-as-text = -<link linkend="FILTER">filter</link> +-<link linkend="content-type-overwrite">content-type-overwrite{text/plain}</link> +-<link linkend="FORCE-TEXT-MODE">force-text-mode</link> -<link linkend="HIDE-CONTENT-DISPOSITION">hide-content-disposition</link></screen>
7231 Say you have accounts on some sites that you visit regularly, and
7232 you don't want to have to log in manually each time. So you'd like
7233 to allow persistent cookies for these sites. The
7234 <literal>allow-all-cookies</literal> alias defined above does exactly
7235 that, i.e. it disables crunching of cookies in any direction, and the
7236 processing of cookies to make them only temporary.
7241 { allow-all-cookies }
7245 .redhat.com</screen>
7249 Your bank is allergic to some filter, but you don't know which, so you disable them all:
7254 { -<link linkend="FILTER">filter</link> }
7255 .your-home-banking-site.com</screen>
7259 Some file types you may not want to filter for various reasons:
7264 # Technical documentation is likely to contain strings that might
7265 # erroneously get altered by the JavaScript-oriented filters:
7270 # And this stupid host sends streaming video with a wrong MIME type,
7271 # so that Privoxy thinks it is getting HTML and starts filtering:
7273 stupid-server.example.com/</screen>
7277 Example of a simple <link linkend="BLOCK">block</link> action. Say you've
7278 seen an ad on your favourite page on example.com that you want to get rid of.
7279 You have right-clicked the image, selected <quote>copy image location</quote>
7280 and pasted the URL below while removing the leading http://, into a
7281 <literal>{ +block{} }</literal> section. Note that <literal>{ +handle-as-image
7282 }</literal> need not be specified, since all URLs ending in
7283 <literal>.gif</literal> will be tagged as images by the general rules as set
7284 in default.action anyway:
7289 { +<link linkend="BLOCK">block</link>{Nasty ads.} }
7290 www.example.com/nasty-ads/sponsor\.gif
7291 another.example.net/more/junk/here/</screen>
7295 The URLs of dynamically generated banners, especially from large banner
7296 farms, often don't use the well-known image file name extensions, which
7297 makes it impossible for <application>Privoxy</application> to guess
7298 the file type just by looking at the URL.
7299 You can use the <literal>+block-as-image</literal> alias defined above for
7301 Note that objects which match this rule but then turn out NOT to be an
7302 image are typically rendered as a <quote>broken image</quote> icon by the
7303 browser. Use cautiously.
7312 ar.atwola.com/</screen>
7316 Now you noticed that the default configuration breaks Forbes Magazine,
7317 but you were too lazy to find out which action is the culprit, and you
7318 were again too lazy to give <link linkend="contact">feedback</link>, so
7319 you just used the <literal>fragile</literal> alias on the site, and
7320 -- <emphasis>whoa!</emphasis> -- it worked. The <literal>fragile</literal>
7321 aliases disables those actions that are most likely to break a site. Also,
7322 good for testing purposes to see if it is <application>Privoxy</application>
7323 that is causing the problem or not. We later find other regular sites
7324 that misbehave, and add those to our personalized list of troublemakers:
7332 .mybank.com</screen>
7336 You like the <quote>fun</quote> text replacements in <filename>default.filter</filename>,
7337 but it is disabled in the distributed actions file.
7338 So you'd like to turn it on in your private,
7339 update-safe config, once and for all:
7344 { +<link linkend="filter-fun">filter{fun}</link> }
7345 / # For ALL sites!</screen>
7349 Note that the above is not really a good idea: There are exceptions
7350 to the filters in <filename>default.action</filename> for things that
7351 really shouldn't be filtered, like code on CVS->Web interfaces. Since
7352 <filename>user.action</filename> has the last word, these exceptions
7353 won't be valid for the <quote>fun</quote> filtering specified here.
7357 You might also worry about how your favourite free websites are
7358 funded, and find that they rely on displaying banner advertisements
7359 to survive. So you might want to specifically allow banners for those
7360 sites that you feel provide value to you:
7372 Note that <literal>allow-ads</literal> has been aliased to
7373 <literal>-<link linkend="block">block</link></literal>,
7374 <literal>-<link linkend="filter-banners-by-size">filter{banners-by-size}</link></literal>, and
7375 <literal>-<link linkend="filter-banners-by-link">filter{banners-by-link}</link></literal> above.
7379 Invoke another alias here to force an over-ride of the MIME type <literal>
7380 application/x-sh</literal> which typically would open a download type
7381 dialog. In my case, I want to look at the shell script, and then I can save
7382 it should I choose to.
7392 <filename>user.action</filename> is generally the best place to define
7393 exceptions and additions to the default policies of
7394 <filename>default.action</filename>. Some actions are safe to have their
7395 default policies set here though. So let's set a default policy to have a
7396 <quote>blank</quote> image as opposed to the checkerboard pattern for
7397 <emphasis>ALL</emphasis> sites. <quote>/</quote> of course matches all URL
7403 { +<link linkend="set-image-blocker">set-image-blocker{blank}</link> }
7404 / # ALL sites</screen>
7410 <!-- ~ End section ~ -->
7414 <!-- ~ End section ~ -->
7416 <!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
7418 <sect1 id="filter-file">
7419 <title>Filter Files</title>
7422 On-the-fly text substitutions need
7423 to be defined in a <quote>filter file</quote>. Once defined, they
7424 can then be invoked as an <quote>action</quote>.
7428 &my-app; supports three different filter actions:
7429 <literal><link linkend="filter">filter</link></literal> to
7430 rewrite the content that is send to the client,
7431 <literal><link linkend="client-header-filter">client-header-filter</link></literal>
7432 to rewrite headers that are send by the client, and
7433 <literal><link linkend="server-header-filter">server-header-filter</link></literal>
7434 to rewrite headers that are send by the server.
7438 &my-app; also supports two tagger actions:
7439 <literal><link linkend="client-header-tagger">client-header-tagger</link></literal>
7441 <literal><link linkend="server-header-tagger">server-header-tagger</link></literal>.
7442 Taggers and filters use the same syntax in the filter files, the difference
7443 is that taggers don't modify the text they are filtering, but use a rewritten
7444 version of the filtered text as tag. The tags can then be used to change the
7445 applying actions through sections with <link linkend="tag-pattern">tag-patterns</link>.
7450 Multiple filter files can be defined through the <literal> <link
7451 linkend="filterfile">filterfile</link></literal> config directive. The filters
7452 as supplied by the developers are located in
7453 <filename>default.filter</filename>. It is recommended that any locally
7454 defined or modified filters go in a separately defined file such as
7455 <filename>user.filter</filename>.
7459 Common tasks for content filters are to eliminate common annoyances in
7460 HTML and JavaScript, such as pop-up windows,
7461 exit consoles, crippled windows without navigation tools, the
7462 infamous <BLINK> tag etc, to suppress images with certain
7463 width and height attributes (standard banner sizes or web-bugs),
7464 or just to have fun.
7468 Enabled content filters are applied to any content whose
7469 <quote>Content Type</quote> header is recognised as a sign
7470 of text-based content, with the exception of <literal>text/plain</literal>.
7471 Use the <link linkend="FORCE-TEXT-MODE">force-text-mode</link> action
7472 to also filter other content.
7476 Substitutions are made at the source level, so if you want to <quote>roll
7477 your own</quote> filters, you should first be familiar with HTML syntax,
7478 and, of course, regular expressions.
7482 Just like the <link linkend="actions-file">actions files</link>, the
7483 filter file is organized in sections, which are called <emphasis>filters</emphasis>
7484 here. Each filter consists of a heading line, that starts with one of the
7485 <emphasis>keywords</emphasis> <literal>FILTER:</literal>,
7486 <literal>CLIENT-HEADER-FILTER:</literal> or <literal>SERVER-HEADER-FILTER:</literal>
7487 followed by the filter's <emphasis>name</emphasis>, and a short (one line)
7488 <emphasis>description</emphasis> of what it does. Below that line
7489 come the <emphasis>jobs</emphasis>, i.e. lines that define the actual
7490 text substitutions. By convention, the name of a filter
7491 should describe what the filter <emphasis>eliminates</emphasis>. The
7492 comment is used in the <ulink url="http://config.privoxy.org/">web-based
7493 user interface</ulink>.
7497 Once a filter called <replaceable>name</replaceable> has been defined
7498 in the filter file, it can be invoked by using an action of the form
7499 +<literal><link linkend="filter">filter</link>{<replaceable>name</replaceable>}</literal>
7500 in any <link linkend="actions-file">actions file</link>.
7504 Filter definitions start with a header line that contains the filter
7505 type, the filter name and the filter description.
7506 A content filter header line for a filter called <quote>foo</quote> could look
7511 <screen>FILTER: foo Replace all "foo" with "bar"</screen>
7515 Below that line, and up to the next header line, come the jobs that
7516 define what text replacements the filter executes. They are specified
7517 in a syntax that imitates <ulink url="http://www.perl.org/">Perl</ulink>'s
7518 <literal>s///</literal> operator. If you are familiar with Perl, you
7519 will find this to be quite intuitive, and may want to look at the
7520 PCRS documentation for the subtle differences to Perl behaviour. Most
7521 notably, the non-standard option letter <literal>U</literal> is supported,
7522 which turns the default to ungreedy matching.
7527 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
7528 Expressions</quote></ulink>, you might want to take a look at
7529 the <link linkend="regex">Appendix on regular expressions</link>, and
7530 see the <ulink url="http://perldoc.perl.org/perlre.html">Perl
7532 <ulink url="http://perldoc.perl.org/perlop.html">the
7533 <literal>s///</literal> operator's syntax</ulink> and <ulink
7534 url="http://perldoc.perl.org/perlre.html">Perl-style regular
7535 expressions</ulink> in general.
7536 The below examples might also help to get you started.
7540 <!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
7542 <sect2><title>Filter File Tutorial</title>
7544 Now, let's complete our <quote>foo</quote> content filter. We have already defined
7545 the heading, but the jobs are still missing. Since all it does is to replace
7546 <quote>foo</quote> with <quote>bar</quote>, there is only one (trivial) job
7551 <screen>s/foo/bar/</screen>
7555 But wait! Didn't the comment say that <emphasis>all</emphasis> occurrences
7556 of <quote>foo</quote> should be replaced? Our current job will only take
7557 care of the first <quote>foo</quote> on each page. For global substitution,
7558 we'll need to add the <literal>g</literal> option:
7562 <screen>s/foo/bar/g</screen>
7566 Our complete filter now looks like this:
7569 <screen>FILTER: foo Replace all "foo" with "bar"
7570 s/foo/bar/g</screen>
7574 Let's look at some real filters for more interesting examples. Here you see
7575 a filter that protects against some common annoyances that arise from JavaScript
7576 abuse. Let's look at its jobs one after the other:
7582 FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse
7584 # Get rid of JavaScript referrer tracking. Test page: http://www.randomoddness.com/untitled.htm
7586 s|(<script.*)document\.referrer(.*</script>)|$1"Not Your Business!"$2|Usg</screen>
7590 Following the header line and a comment, you see the job. Note that it uses
7591 <literal>|</literal> as the delimiter instead of <literal>/</literal>, because
7592 the pattern contains a forward slash, which would otherwise have to be escaped
7593 by a backslash (<literal>\</literal>).
7597 Now, let's examine the pattern: it starts with the text <literal><script.*</literal>
7598 enclosed in parentheses. Since the dot matches any character, and <literal>*</literal>
7599 means: <quote>Match an arbitrary number of the element left of myself</quote>, this
7600 matches <quote><script</quote>, followed by <emphasis>any</emphasis> text, i.e.
7601 it matches the whole page, from the start of the first <script> tag.
7605 That's more than we want, but the pattern continues: <literal>document\.referrer</literal>
7606 matches only the exact string <quote>document.referrer</quote>. The dot needed to
7607 be <emphasis>escaped</emphasis>, i.e. preceded by a backslash, to take away its
7608 special meaning as a joker, and make it just a regular dot. So far, the meaning is:
7609 Match from the start of the first <script> tag in a the page, up to, and including,
7610 the text <quote>document.referrer</quote>, if <emphasis>both</emphasis> are present
7611 in the page (and appear in that order).
7615 But there's still more pattern to go. The next element, again enclosed in parentheses,
7616 is <literal>.*</script></literal>. You already know what <literal>.*</literal>
7617 means, so the whole pattern translates to: Match from the start of the first <script>
7618 tag in a page to the end of the last <script> tag, provided that the text
7619 <quote>document.referrer</quote> appears somewhere in between.
7623 This is still not the whole story, since we have ignored the options and the parentheses:
7624 The portions of the page matched by sub-patterns that are enclosed in parentheses, will be
7625 remembered and be available through the variables <literal>$1, $2, ...</literal> in
7626 the substitute. The <literal>U</literal> option switches to ungreedy matching, which means
7627 that the first <literal>.*</literal> in the pattern will only <quote>eat up</quote> all
7628 text in between <quote><script</quote> and the <emphasis>first</emphasis> occurrence
7629 of <quote>document.referrer</quote>, and that the second <literal>.*</literal> will
7630 only span the text up to the <emphasis>first</emphasis> <quote></script></quote>
7631 tag. Furthermore, the <literal>s</literal> option says that the match may span
7632 multiple lines in the page, and the <literal>g</literal> option again means that the
7633 substitution is global.
7637 So, to summarize, the pattern means: Match all scripts that contain the text
7638 <quote>document.referrer</quote>. Remember the parts of the script from
7639 (and including) the start tag up to (and excluding) the string
7640 <quote>document.referrer</quote> as <literal>$1</literal>, and the part following
7641 that string, up to and including the closing tag, as <literal>$2</literal>.
7645 Now the pattern is deciphered, but wasn't this about substituting things? So
7646 lets look at the substitute: <literal>$1"Not Your Business!"$2</literal> is
7647 easy to read: The text remembered as <literal>$1</literal>, followed by
7648 <literal>"Not Your Business!"</literal> (<emphasis>including</emphasis>
7649 the quotation marks!), followed by the text remembered as <literal>$2</literal>.
7650 This produces an exact copy of the original string, with the middle part
7651 (the <quote>document.referrer</quote>) replaced by <literal>"Not Your
7652 Business!"</literal>.
7656 The whole job now reads: Replace <quote>document.referrer</quote> by
7657 <literal>"Not Your Business!"</literal> wherever it appears inside a
7658 <script> tag. Note that this job won't break JavaScript syntax,
7659 since both the original and the replacement are syntactically valid
7660 string objects. The script just won't have access to the referrer
7661 information anymore.
7665 We'll show you two other jobs from the JavaScript taming department, but
7666 this time only point out the constructs of special interest:
7671 # The status bar is for displaying link targets, not pointless blahblah
7673 s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig</screen>
7677 <literal>\s</literal> stands for whitespace characters (space, tab, newline,
7678 carriage return, form feed), so that <literal>\s*</literal> means: <quote>zero
7679 or more whitespace</quote>. The <literal>?</literal> in <literal>.*?</literal>
7680 makes this matching of arbitrary text ungreedy. (Note that the <literal>U</literal>
7681 option is not set). The <literal>['"]</literal> construct means: <quote>a single
7682 <emphasis>or</emphasis> a double quote</quote>. Finally, <literal>\1</literal> is
7683 a back-reference to the first parenthesis just like <literal>$1</literal> above,
7684 with the difference that in the <emphasis>pattern</emphasis>, a backslash indicates
7685 a back-reference, whereas in the <emphasis>substitute</emphasis>, it's the dollar.
7689 So what does this job do? It replaces assignments of single- or double-quoted
7690 strings to the <quote>window.status</quote> object with a dummy assignment
7691 (using a variable name that is hopefully odd enough not to conflict with
7692 real variables in scripts). Thus, it catches many cases where e.g. pointless
7693 descriptions are displayed in the status bar instead of the link target when
7694 you move your mouse over links.
7699 # Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html
7701 s/(<body [^>]*)onunload(.*>)/$1never$2/iU</screen>
7706 <ulink url="http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-htmlevents">OnUnload
7707 event binding</ulink> in the HTML DOM was a <emphasis>CRIME</emphasis>.
7708 When I close a browser window, I want it to close and die. Basta.
7709 This job replaces the <quote>onunload</quote> attribute in
7710 <quote><body></quote> tags with the dummy word <literal>never</literal>.
7711 Note that the <literal>i</literal> option makes the pattern matching
7712 case-insensitive. Also note that ungreedy matching alone doesn't always guarantee
7713 a minimal match: In the first parenthesis, we had to use <literal>[^>]*</literal>
7714 instead of <literal>.*</literal> to prevent the match from exceeding the
7715 <body> tag if it doesn't contain <quote>OnUnload</quote>, but the page's
7720 The last example is from the fun department:
7725 FILTER: fun Fun text replacements
7727 # Spice the daily news:
7729 s/microsoft(?!\.com)/MicroSuck/ig</screen>
7733 Note the <literal>(?!\.com)</literal> part (a so-called negative lookahead)
7734 in the job's pattern, which means: Don't match, if the string
7735 <quote>.com</quote> appears directly following <quote>microsoft</quote>
7736 in the page. This prevents links to microsoft.com from being trashed, while
7737 still replacing the word everywhere else.
7742 # Buzzword Bingo (example for extended regex syntax)
7744 s* industry[ -]leading \
7746 | customer[ -]focused \
7747 | market[ -]driven \
7748 | award[ -]winning # Comments are OK, too! \
7749 | high[ -]performance \
7750 | solutions[ -]based \
7754 *<font color="red"><b>BINGO!</b></font> \
7759 The <literal>x</literal> option in this job turns on extended syntax, and allows for
7760 e.g. the liberal use of (non-interpreted!) whitespace for nicer formatting.
7768 <!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
7770 <sect2 id="predefined-filters"><title>The Pre-defined Filters</title>
7774 Note each filter is also listed in the +filter action section above. Please
7775 keep these listings in sync.
7780 The distribution <filename>default.filter</filename> file contains a selection of
7781 pre-defined filters for your convenience:
7786 <term><emphasis>js-annoyances</emphasis></term>
7789 The purpose of this filter is to get rid of particularly annoying JavaScript abuse.
7794 replaces JavaScript references to the browser's referrer information
7795 with the string "Not Your Business!". This compliments the <literal><link
7796 linkend="hide-referrer">hide-referrer</link></literal> action on the content level.
7801 removes the bindings to the DOM's
7802 <ulink url="http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-htmlevents">unload
7803 event</ulink> which we feel has no right to exist and is responsible for most <quote>exit consoles</quote>, i.e.
7804 nasty windows that pop up when you close another one.
7809 removes code that causes new windows to be opened with undesired properties, such as being
7810 full-screen, non-resizeable, without location, status or menu bar etc.
7816 Use with caution. This is an aggressive filter, and can break sites that
7817 rely heavily on JavaScript.
7823 <term><emphasis>js-events</emphasis></term>
7826 This is a very radical measure. It removes virtually all JavaScript event bindings, which
7827 means that scripts can not react to user actions such as mouse movements or clicks, window
7828 resizing etc, anymore. Use with caution!
7831 We <emphasis>strongly discourage</emphasis> using this filter as a default since it breaks
7832 many legitimate scripts. It is meant for use only on extra-nasty sites (should you really
7839 <term><emphasis>html-annoyances</emphasis></term>
7842 This filter will undo many common instances of HTML based abuse.
7845 The <literal>BLINK</literal> and <literal>MARQUEE</literal> tags
7846 are neutralized (yeah baby!), and browser windows will be created as
7847 resizeable (as of course they should be!), and will have location,
7848 scroll and menu bars -- even if specified otherwise.
7854 <term><emphasis>content-cookies</emphasis></term>
7857 Most cookies are set in the HTTP dialog, where they can be intercepted
7859 <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal>
7860 and <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal>
7861 actions. But web sites increasingly make use of HTML meta tags and JavaScript
7862 to sneak cookies to the browser on the content level.
7865 This filter disables most HTML and JavaScript code that reads or sets
7866 cookies. It cannot detect all clever uses of these types of code, so it
7867 should not be relied on as an absolute fix. Use it wherever you would also
7868 use the cookie crunch actions.
7874 <term><emphasis>refresh-tags</emphasis></term>
7877 Disable any refresh tags if the interval is greater than nine seconds (so
7878 that redirections done via refresh tags are not destroyed). This is useful
7879 for dial-on-demand setups, or for those who find this HTML feature
7886 <term><emphasis>unsolicited-popups</emphasis></term>
7889 This filter attempts to prevent only <quote>unsolicited</quote> pop-up
7890 windows from opening, yet still allow pop-up windows that the user
7891 has explicitly chosen to open. It was added in version 3.0.1,
7892 as an improvement over earlier such filters.
7895 Technical note: The filter works by redefining the window.open JavaScript
7896 function to a dummy function, <literal>PrivoxyWindowOpen()</literal>,
7897 during the loading and rendering phase of each HTML page access, and
7898 restoring the function afterward.
7901 This is recommended only for browsers that cannot perform this function
7902 reliably themselves. And be aware that some sites require such windows
7903 in order to function normally. Use with caution.
7909 <term><emphasis>all-popups</emphasis></term>
7912 Attempt to prevent <emphasis>all</emphasis> pop-up windows from opening.
7913 Note this should be used with even more discretion than the above, since
7914 it is more likely to break some sites that require pop-ups for normal
7915 usage. Use with caution.
7921 <term><emphasis>img-reorder</emphasis></term>
7924 This is a helper filter that has no value if used alone. It makes the
7925 <literal>banners-by-size</literal> and <literal>banners-by-link</literal>
7926 (see below) filters more effective and should be enabled together with them.
7932 <term><emphasis>banners-by-size</emphasis></term>
7935 This filter removes image tags purely based on what size they are. Fortunately
7936 for us, many ads and banner images tend to conform to certain standardized
7937 sizes, which makes this filter quite effective for ad stripping purposes.
7940 Occasionally this filter will cause false positives on images that are not ads,
7941 but just happen to be of one of the standard banner sizes.
7944 Recommended only for those who require extreme ad blocking. The default
7945 block rules should catch 95+% of all ads <emphasis>without</emphasis> this filter enabled.
7951 <term><emphasis>banners-by-link</emphasis></term>
7954 This is an experimental filter that attempts to kill any banners if
7955 their URLs seem to point to known or suspected click trackers. It is currently
7956 not of much value and is not recommended for use by default.
7962 <term><emphasis>webbugs</emphasis></term>
7965 Webbugs are small, invisible images (technically 1X1 GIF images), that
7966 are used to track users across websites, and collect information on them.
7967 As an HTML page is loaded by the browser, an embedded image tag causes the
7968 browser to contact a third-party site, disclosing the tracking information
7969 through the requested URL and/or cookies for that third-party domain, without
7970 the user ever becoming aware of the interaction with the third-party site.
7971 HTML-ized spam also uses a similar technique to verify email addresses.
7974 This filter removes the HTML code that loads such <quote>webbugs</quote>.
7980 <term><emphasis>tiny-textforms</emphasis></term>
7983 A rather special-purpose filter that can be used to enlarge textareas (those
7984 multi-line text boxes in web forms) and turn off hard word wrap in them.
7985 It was written for the sourceforge.net tracker system where such boxes are
7986 a nuisance, but it can be handy on other sites, too.
7989 It is not recommended to use this filter as a default.
7995 <term><emphasis>jumping-windows</emphasis></term>
7998 Many consider windows that move, or resize themselves to be abusive. This filter
7999 neutralizes the related JavaScript code. Note that some sites might not display
8000 or behave as intended when using this filter. Use with caution.
8006 <term><emphasis>frameset-borders</emphasis></term>
8009 Some web designers seem to assume that everyone in the world will view their
8010 web sites using the same browser brand and version, screen resolution etc,
8011 because only that assumption could explain why they'd use static frame sizes,
8012 yet prevent their frames from being resized by the user, should they be too
8013 small to show their whole content.
8016 This filter removes the related HTML code. It should only be applied to sites
8023 <term><emphasis>demoronizer</emphasis></term>
8026 Many Microsoft products that generate HTML use non-standard extensions (read:
8027 violations) of the ISO 8859-1 aka Latin-1 character set. This can cause those
8028 HTML documents to display with errors on standard-compliant platforms.
8031 This filter translates the MS-only characters into Latin-1 equivalents.
8032 It is not necessary when using MS products, and will cause corruption of
8033 all documents that use 8-bit character sets other than Latin-1. It's mostly
8034 worthwhile for Europeans on non-MS platforms, if weird garbage characters
8035 sometimes appear on some pages, or user agents that don't correct for this on
8038 My version of Mozilla (ancient) shows litte square boxes for quote
8039 characters, and apostrophes on moronized pages. So many pages have this, I
8040 can read them fine now. HB 08/27/06
8047 <term><emphasis>shockwave-flash</emphasis></term>
8050 A filter for shockwave haters. As the name suggests, this filter strips code
8051 out of web pages that is used to embed shockwave flash objects.
8059 <term><emphasis>quicktime-kioskmode</emphasis></term>
8062 Change HTML code that embeds Quicktime objects so that kioskmode, which
8063 prevents saving, is disabled.
8069 <term><emphasis>fun</emphasis></term>
8072 Text replacements for subversive browsing fun. Make fun of your favorite
8073 Monopolist or play buzzword bingo.
8079 <term><emphasis>crude-parental</emphasis></term>
8082 A demonstration-only filter that shows how <application>Privoxy</application>
8083 can be used to delete web content on a keyword basis.
8089 <term><emphasis>ie-exploits</emphasis></term>
8092 An experimental collection of text replacements to disable malicious HTML and JavaScript
8093 code that exploits known security holes in Internet Explorer.
8096 Presently, it only protects against Nimda and a cross-site scripting bug, and
8097 would need active maintenance to provide more substantial protection.
8103 <term><emphasis>site-specifics</emphasis></term>
8106 Some web sites have very specific problems, the cure for which doesn't apply
8107 anywhere else, or could even cause damage on other sites.
8110 This is a collection of such site-specific cures which should only be applied
8111 to the sites they were intended for, which is what the supplied
8112 <filename>default.action</filename> file does. Users shouldn't need to change
8113 anything regarding this filter.
8119 <term><emphasis>google</emphasis></term>
8122 A CSS based block for Google text ads. Also removes a width limitation
8123 and the toolbar advertisement.
8129 <term><emphasis>yahoo</emphasis></term>
8132 Another CSS based block, this time for Yahoo text ads. And removes
8133 a width limitation as well.
8139 <term><emphasis>msn</emphasis></term>
8142 Another CSS based block, this time for MSN text ads. And removes
8143 tracking URLs, as well as a width limitation.
8149 <term><emphasis>blogspot</emphasis></term>
8152 Cleans up some Blogspot blogs. Read the fine print before using this one!
8155 This filter also intentionally removes some navigation stuff and sets the
8156 page width to 100%. As a result, some rounded <quote>corners</quote> would
8157 appear to early or not at all and as fixing this would require a browser
8158 that understands background-size (CSS3), they are removed instead.
8164 <term><emphasis>xml-to-html</emphasis></term>
8167 Server-header filter to change the Content-Type from xml to html.
8173 <term><emphasis>html-to-xml</emphasis></term>
8176 Server-header filter to change the Content-Type from html to xml.
8182 <term><emphasis>no-ping</emphasis></term>
8185 Removes the non-standard <literal>ping</literal> attribute from
8186 anchor and area HTML tags.
8192 <term><emphasis>hide-tor-exit-notation</emphasis></term>
8195 Client-header filter to remove the <command>Tor</command> exit node notation
8196 found in Host and Referer headers.
8199 If &my-app; and <command>Tor</command> are chained and &my-app;
8200 is configured to use socks4a, one can use <quote>http://www.example.org.foobar.exit/</quote>
8201 to access the host <quote>www.example.org</quote> through the
8202 <command>Tor</command> exit node <quote>foobar</quote>.
8205 As the HTTP client isn't aware of this notation, it treats the
8206 whole string <quote>www.example.org.foobar.exit</quote> as host and uses it
8207 for the <quote>Host</quote> and <quote>Referer</quote> headers. From the
8208 server's point of view the resulting headers are invalid and can cause problems.
8211 An invalid <quote>Referer</quote> header can trigger <quote>hot-linking</quote>
8212 protections, an invalid <quote>Host</quote> header will make it impossible for
8213 the server to find the right vhost (several domains hosted on the same IP address).
8216 This client-header filter removes the <quote>foo.exit</quote> part in those headers
8217 to prevent the mentioned problems. Note that it only modifies
8218 the HTTP headers, it doesn't make it impossible for the server
8219 to detect your <command>Tor</command> exit node based on the IP address
8220 the request is coming from.
8227 <term><emphasis> </emphasis></term>
8241 <!-- ~ End section ~ -->
8245 <!-- ~~~~~ New section ~~~~~ -->
8247 <sect1 id="templates">
8248 <title>Privoxy's Template Files</title>
8250 All <application>Privoxy</application> built-in pages, i.e. error pages such as the
8251 <ulink url="http://show-the-404-error.page"><quote>404 - No Such Domain</quote>
8252 error page</ulink>, the <ulink
8253 url="http://ads.bannerserver.example.com/nasty-ads/sponsor.html"><quote>BLOCKED</quote>
8255 and all pages of its <ulink url="http://config.privoxy.org/">web-based
8256 user interface</ulink>, are generated from <emphasis>templates</emphasis>.
8257 (<application>Privoxy</application> must be running for the above links to work as
8262 These templates are stored in a subdirectory of the <link linkend="confdir">configuration
8263 directory</link> called <filename>templates</filename>. On Unixish platforms,
8265 <ulink url="file:///etc/privoxy/templates/"><filename>/etc/privoxy/templates/</filename></ulink>.
8269 The templates are basically normal HTML files, but with place-holders (called symbols
8270 or exports), which <application>Privoxy</application> fills at run time. It
8271 is possible to edit the templates with a normal text editor, should you want
8272 to customize them. (<emphasis>Not recommended for the casual
8273 user</emphasis>). Should you create your own custom templates, you should use
8274 the <filename>config</filename> setting <link linkend="templdir">templdir</link>
8275 to specify an alternate location, so your templates do not get overwritten
8279 Note that just like in configuration files, lines starting
8280 with <literal>#</literal> are ignored when the templates are filled in.
8284 The place-holders are of the form <literal>@name@</literal>, and you will
8285 find a list of available symbols, which vary from template to template,
8286 in the comments at the start of each file. Note that these comments are not
8287 always accurate, and that it's probably best to look at the existing HTML
8288 code to find out which symbols are supported and what they are filled in with.
8292 A special application of this substitution mechanism is to make whole
8293 blocks of HTML code disappear when a specific symbol is set. We use this
8294 for many purposes, one of them being to include the beta warning in all
8295 our user interface (CGI) pages when <application>Privoxy</application>
8296 is in an alpha or beta development stage:
8301 <!-- @if-unstable-start -->
8303 ... beta warning HTML code goes here ...
8305 <!-- if-unstable-end@ --></screen>
8309 If the "unstable" symbol is set, everything in between and including
8310 <literal>@if-unstable-start</literal> and <literal>if-unstable-end@</literal>
8311 will disappear, leaving nothing but an empty comment:
8315 <screen><!-- --></screen>
8319 There's also an if-then-else construct and an <literal>#include</literal>
8320 mechanism, but you'll sure find out if you are inclined to edit the
8325 All templates refer to a style located at
8326 <ulink url="http://config.privoxy.org/send-stylesheet"><literal>http://config.privoxy.org/send-stylesheet</literal></ulink>.
8327 This is, of course, locally served by <application>Privoxy</application>
8328 and the source for it can be found and edited in the
8329 <filename>cgi-style.css</filename> template.
8334 <!-- ~ End section ~ -->
8338 <!-- ~~~~~ New section ~~~~~ -->
8340 <sect1 id="contact"><title>Contacting the Developers, Bug Reporting and Feature
8343 <!-- Include contacting.sgml boilerplate: -->
8345 <!-- end boilerplate -->
8349 <!-- ~ End section ~ -->
8352 <!-- ~~~~~ New section ~~~~~ -->
8353 <sect1 id="copyright"><title>Privoxy Copyright, License and History</title>
8355 <!-- Include copyright.sgml: -->
8357 <!-- end copyright -->
8359 <!-- ~~~~~ New section ~~~~~ -->
8360 <sect2><title>License</title>
8361 <!-- Include copyright.sgml: -->
8363 <!-- end copyright -->
8365 <!-- ~ End section ~ -->
8368 <!-- ~~~~~ New section ~~~~~ -->
8370 <sect2 id="history"><title>History</title>
8371 <!-- Include history.sgml: -->
8373 <!-- end history -->
8376 <sect2 id="authors"><title>Authors</title>
8377 <!-- Include p-authors.sgml: -->
8379 <!-- end authors -->
8384 <!-- ~ End section ~ -->
8387 <!-- ~~~~~ New section ~~~~~ -->
8388 <sect1 id="seealso"><title>See Also</title>
8389 <!-- Include seealso.sgml: -->
8391 <!-- end seealso -->
8396 <!-- ~~~~~ New section ~~~~~ -->
8397 <sect1 id="appendix"><title>Appendix</title>
8400 <!-- ~~~~~ New section ~~~~~ -->
8402 <title>Regular Expressions</title>
8404 <application>Privoxy</application> uses Perl-style <quote>regular
8405 expressions</quote> in its <link linkend="actions-file">actions
8406 files</link> and <link linkend="filter-file">filter file</link>,
8407 through the <ulink url="http://www.pcre.org/">PCRE</ulink> and
8410 <ulink url="http://www.oesterhelt.org/pcrs/">PCRS</ulink> libraries.
8412 <application>PCRS</application> libraries.
8416 If you are reading this, you probably don't understand what <quote>regular
8417 expressions</quote> are, or what they can do. So this will be a very brief
8418 introduction only. A full explanation would require a <ulink
8419 url="http://www.oreilly.com/catalog/regex/">book</ulink> ;-)
8423 Regular expressions provide a language to describe patterns that can be
8424 run against strings of characters (letter, numbers, etc), to see if they
8425 match the string or not. The patterns are themselves (sometimes complex)
8426 strings of literal characters, combined with wild-cards, and other special
8427 characters, called meta-characters. The <quote>meta-characters</quote> have
8428 special meanings and are used to build complex patterns to be matched against.
8429 Perl Compatible Regular Expressions are an especially convenient
8430 <quote>dialect</quote> of the regular expression language.
8434 To make a simple analogy, we do something similar when we use wild-card
8435 characters when listing files with the <command>dir</command> command in DOS.
8436 <literal>*.*</literal> matches all filenames. The <quote>special</quote>
8437 character here is the asterisk which matches any and all characters. We can be
8438 more specific and use <literal>?</literal> to match just individual
8439 characters. So <quote>dir file?.text</quote> would match
8440 <quote>file1.txt</quote>, <quote>file2.txt</quote>, etc. We are pattern
8441 matching, using a similar technique to <quote>regular expressions</quote>!
8445 Regular expressions do essentially the same thing, but are much, much more
8446 powerful. There are many more <quote>special characters</quote> and ways of
8447 building complex patterns however. Let's look at a few of the common ones,
8448 and then some examples:
8453 <emphasis>.</emphasis> - Matches any single character, e.g. <quote>a</quote>,
8454 <quote>A</quote>, <quote>4</quote>, <quote>:</quote>, or <quote>@</quote>.
8456 </simplelist></para>
8460 <emphasis>?</emphasis> - The preceding character or expression is matched ZERO or ONE
8463 </simplelist></para>
8467 <emphasis>+</emphasis> - The preceding character or expression is matched ONE or MORE
8470 </simplelist></para>
8474 <emphasis>*</emphasis> - The preceding character or expression is matched ZERO or MORE
8477 </simplelist></para>
8481 <emphasis>\</emphasis> - The <quote>escape</quote> character denotes that
8482 the following character should be taken literally. This is used where one of the
8483 special characters (e.g. <quote>.</quote>) needs to be taken literally and
8484 not as a special meta-character. Example: <quote>example\.com</quote>, makes
8485 sure the period is recognized only as a period (and not expanded to its
8486 meta-character meaning of any single character).
8488 </simplelist></para>
8492 <emphasis>[ ]</emphasis> - Characters enclosed in brackets will be matched if
8493 any of the enclosed characters are encountered. For instance, <quote>[0-9]</quote>
8494 matches any numeric digit (zero through nine). As an example, we can combine
8495 this with <quote>+</quote> to match any digit one of more times: <quote>[0-9]+</quote>.
8497 </simplelist></para>
8501 <emphasis>( )</emphasis> - parentheses are used to group a sub-expression,
8502 or multiple sub-expressions.
8504 </simplelist></para>
8508 <emphasis>|</emphasis> - The <quote>bar</quote> character works like an
8509 <quote>or</quote> conditional statement. A match is successful if the
8510 sub-expression on either side of <quote>|</quote> matches. As an example:
8511 <quote>/(this|that) example/</quote> uses grouping and the bar character
8512 and would match either <quote>this example</quote> or <quote>that
8513 example</quote>, and nothing else.
8515 </simplelist></para>
8518 These are just some of the ones you are likely to use when matching URLs with
8519 <application>Privoxy</application>, and is a long way from a definitive
8520 list. This is enough to get us started with a few simple examples which may
8521 be more illuminating:
8525 <emphasis><literal>/.*/banners/.*</literal></emphasis> - A simple example
8526 that uses the common combination of <quote>.</quote> and <quote>*</quote> to
8527 denote any character, zero or more times. In other words, any string at all.
8528 So we start with a literal forward slash, then our regular expression pattern
8529 (<quote>.*</quote>) another literal forward slash, the string
8530 <quote>banners</quote>, another forward slash, and lastly another
8531 <quote>.*</quote>. We are building
8532 a directory path here. This will match any file with the path that has a
8533 directory named <quote>banners</quote> in it. The <quote>.*</quote> matches
8534 any characters, and this could conceivably be more forward slashes, so it
8535 might expand into a much longer looking path. For example, this could match:
8536 <quote>/eye/hate/spammers/banners/annoy_me_please.gif</quote>, or just
8537 <quote>/banners/annoying.html</quote>, or almost an infinite number of other
8538 possible combinations, just so it has <quote>banners</quote> in the path
8543 And now something a little more complex:
8547 <emphasis><literal>/.*/adv((er)?ts?|ertis(ing|ements?))?/</literal></emphasis> -
8548 We have several literal forward slashes again (<quote>/</quote>), so we are
8549 building another expression that is a file path statement. We have another
8550 <quote>.*</quote>, so we are matching against any conceivable sub-path, just so
8551 it matches our expression. The only true literal that <emphasis>must
8552 match</emphasis> our pattern is <application>adv</application>, together with
8553 the forward slashes. What comes after the <quote>adv</quote> string is the
8558 Remember the <quote>?</quote> means the preceding expression (either a
8559 literal character or anything grouped with <quote>(...)</quote> in this case)
8560 can exist or not, since this means either zero or one match. So
8561 <quote>((er)?ts?|ertis(ing|ements?))</quote> is optional, as are the
8562 individual sub-expressions: <quote>(er)</quote>,
8563 <quote>(ing|ements?)</quote>, and the <quote>s</quote>. The <quote>|</quote>
8564 means <quote>or</quote>. We have two of those. For instance,
8565 <quote>(ing|ements?)</quote>, can expand to match either <quote>ing</quote>
8566 <emphasis>OR</emphasis> <quote>ements?</quote>. What is being done here, is an
8567 attempt at matching as many variations of <quote>advertisement</quote>, and
8568 similar, as possible. So this would expand to match just <quote>adv</quote>,
8569 or <quote>advert</quote>, or <quote>adverts</quote>, or
8570 <quote>advertising</quote>, or <quote>advertisement</quote>, or
8571 <quote>advertisements</quote>. You get the idea. But it would not match
8572 <quote>advertizements</quote> (with a <quote>z</quote>). We could fix that by
8573 changing our regular expression to:
8574 <quote>/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/</quote>, which would then match
8579 <emphasis><literal>/.*/advert[0-9]+\.(gif|jpe?g)</literal></emphasis> - Again
8580 another path statement with forward slashes. Anything in the square brackets
8581 <quote>[ ]</quote> can be matched. This is using <quote>0-9</quote> as a
8582 shorthand expression to mean any digit one through nine. It is the same as
8583 saying <quote>0123456789</quote>. So any digit matches. The <quote>+</quote>
8584 means one or more of the preceding expression must be included. The preceding
8585 expression here is what is in the square brackets -- in this case, any digit
8586 one through nine. Then, at the end, we have a grouping: <quote>(gif|jpe?g)</quote>.
8587 This includes a <quote>|</quote>, so this needs to match the expression on
8588 either side of that bar character also. A simple <quote>gif</quote> on one side, and the other
8589 side will in turn match either <quote>jpeg</quote> or <quote>jpg</quote>,
8590 since the <quote>?</quote> means the letter <quote>e</quote> is optional and
8591 can be matched once or not at all. So we are building an expression here to
8592 match image GIF or JPEG type image file. It must include the literal
8593 string <quote>advert</quote>, then one or more digits, and a <quote>.</quote>
8594 (which is now a literal, and not a special character, since it is escaped
8595 with <quote>\</quote>), and lastly either <quote>gif</quote>, or
8596 <quote>jpeg</quote>, or <quote>jpg</quote>. Some possible matches would
8597 include: <quote>//advert1.jpg</quote>,
8598 <quote>/nasty/ads/advert1234.gif</quote>,
8599 <quote>/banners/from/hell/advert99.jpg</quote>. It would not match
8600 <quote>advert1.gif</quote> (no leading slash), or
8601 <quote>/adverts232.jpg</quote> (the expression does not include an
8602 <quote>s</quote>), or <quote>/advert1.jsp</quote> (<quote>jsp</quote> is not
8603 in the expression anywhere).
8607 We are barely scratching the surface of regular expressions here so that you
8608 can understand the default <application>Privoxy</application>
8609 configuration files, and maybe use this knowledge to customize your own
8610 installation. There is much, much more that can be done with regular
8611 expressions. Now that you know enough to get started, you can learn more on
8616 More reading on Perl Compatible Regular expressions:
8617 <ulink url="http://perldoc.perl.org/perlre.html">http://perldoc.perl.org/perlre.html</ulink>
8621 For information on regular expression based substitutions and their applications
8622 in filters, please see the <link linkend="filter-file">filter file tutorial</link>
8627 <!-- ~ End section ~ -->
8630 <!-- ~~~~~ New section ~~~~~ -->
8632 <title>Privoxy's Internal Pages</title>
8635 Since <application>Privoxy</application> proxies each requested
8636 web page, it is easy for <application>Privoxy</application> to
8637 trap certain special URLs. In this way, we can talk directly to
8638 <application>Privoxy</application>, and see how it is
8639 configured, see how our rules are being applied, change these
8640 rules and other configuration options, and even turn
8641 <application>Privoxy's</application> filtering off, all with
8647 The URLs listed below are the special ones that allow direct access
8648 to <application>Privoxy</application>. Of course,
8649 <application>Privoxy</application> must be running to access these. If
8650 not, you will get a friendly error message. Internet access is not
8663 <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
8667 There is a shortcut: <ulink url="http://p.p/">http://p.p/</ulink> (But it
8668 doesn't provide a fall-back to a real page, in case the request is not
8669 sent through <application>Privoxy</application>)
8675 Show information about the current configuration, including viewing and
8676 editing of actions files:
8680 <ulink url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
8687 Show the source code version numbers:
8691 <ulink url="http://config.privoxy.org/show-version">http://config.privoxy.org/show-version</ulink>
8698 Show the browser's request headers:
8702 <ulink url="http://config.privoxy.org/show-request">http://config.privoxy.org/show-request</ulink>
8709 Show which actions apply to a URL and why:
8713 <ulink url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
8720 Toggle Privoxy on or off. This feature can be turned off/on in the main
8721 <filename>config</filename> file. When toggled <quote>off</quote>, <quote>Privoxy</quote>
8722 continues to run, but only as a pass-through proxy, with no actions taking
8727 <ulink url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>
8731 Short cuts. Turn off, then on:
8735 <ulink url="http://config.privoxy.org/toggle?set=disable">http://config.privoxy.org/toggle?set=disable</ulink>
8740 <ulink url="http://config.privoxy.org/toggle?set=enable">http://config.privoxy.org/toggle?set=enable</ulink>
8749 These may be bookmarked for quick reference. See next.
8753 <sect3 id="bookmarklets">
8754 <title>Bookmarklets</title>
8756 Below are some <quote>bookmarklets</quote> to allow you to easily access a
8757 <quote>mini</quote> version of some of <application>Privoxy's</application>
8758 special pages. They are designed for MS Internet Explorer, but should work
8759 equally well in Netscape, Mozilla, and other browsers which support
8760 JavaScript. They are designed to run directly from your bookmarks - not by
8761 clicking the links below (although that should work for testing).
8764 To save them, right-click the link and choose <quote>Add to Favorites</quote>
8765 (IE) or <quote>Add Bookmark</quote> (Netscape). You will get a warning that
8766 the bookmark <quote>may not be safe</quote> - just click OK. Then you can run the
8767 Bookmarklet directly from your favorites/bookmarks. For even faster access,
8768 you can put them on the <quote>Links</quote> bar (IE) or the <quote>Personal
8769 Toolbar</quote> (Netscape), and run them with a single click.
8778 url="javascript:void(window.open('http://config.privoxy.org/toggle?mini=y&set=enabled','ijbstatus','width=250,height=100,resizable=yes,scrollbars=no,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());">Privoxy - Enable</ulink>
8785 url="javascript:void(window.open('http://config.privoxy.org/toggle?mini=y&set=disabled','ijbstatus','width=250,height=100,resizable=yes,scrollbars=no,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());">Privoxy - Disable</ulink>
8792 url="javascript:void(window.open('http://config.privoxy.org/toggle?mini=y&set=toggle','ijbstatus','width=250,height=100,resizable=yes,scrollbars=no,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());">Privoxy - Toggle Privoxy</ulink> (Toggles between enabled and disabled)
8799 url="javascript:void(window.open('http://config.privoxy.org/toggle?mini=y','ijbstatus','width=250,height=2,resizable=yes,scrollbars=no,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());">Privoxy- View Status</ulink>
8805 <ulink url="javascript:w=Math.floor(screen.width/2);h=Math.floor(screen.height*0.9);void(window.open('http://www.privoxy.org/actions/index.php?url='+escape(location.href),'Feedback','screenx='+w+',width='+w+',height='+h+',scrollbars=yes,toolbar=no,location=no,directories=no,status=no,menubar=no,copyhistory=no').focus());">Privoxy - Submit Actions File Feedback</ulink>
8811 <ulink url="javascript:void(window.open('http://config.privoxy.org/show-url-info?url='+escape(location.href),'Why').focus());">Privoxy - Why?</ulink>
8818 Credit: The site which gave us the general idea for these bookmarklets is
8819 <ulink url="http://www.bookmarklets.com/">www.bookmarklets.com</ulink>. They
8820 have more information about bookmarklets.
8829 <!-- ~~~~~ New section ~~~~~ -->
8831 <title>Chain of Events</title>
8833 Let's take a quick look at how some of <application>Privoxy's</application>
8834 core features are triggered, and the ensuing sequence of events when a web
8835 page is requested by your browser:
8842 First, your web browser requests a web page. The browser knows to send
8843 the request to <application>Privoxy</application>, which will in turn,
8844 relay the request to the remote web server after passing the following
8850 <application>Privoxy</application> traps any request for its own internal CGI
8851 pages (e.g <ulink url="http://p.p/">http://p.p/</ulink>) and sends the CGI page back to the browser.
8856 Next, <application>Privoxy</application> checks to see if the URL
8858 linkend="BLOCK"><quote>+block</quote></link> patterns. If
8859 so, the URL is then blocked, and the remote web server will not be contacted.
8860 <link linkend="HANDLE-AS-IMAGE"><quote>+handle-as-image</quote></link>
8862 <link linkend="HANDLE-AS-EMPTY-DOCUMENT"><quote>+handle-as-empty-document</quote></link>
8863 are then checked, and if there is no match, an
8864 HTML <quote>BLOCKED</quote> page is sent back to the browser. Otherwise, if
8865 it does match, an image is returned for the former, and an empty text
8866 document for the latter. The type of image would depend on the setting of
8867 <link linkend="SET-IMAGE-BLOCKER"><quote>+set-image-blocker</quote></link>
8868 (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
8873 Untrusted URLs are blocked. If URLs are being added to the
8874 <filename>trust</filename> file, then that is done.
8879 If the URL pattern matches the <link
8880 linkend="FAST-REDIRECTS"><quote>+fast-redirects</quote></link> action,
8881 it is then processed. Unwanted parts of the requested URL are stripped.
8886 Now the rest of the client browser's request headers are processed. If any
8887 of these match any of the relevant actions (e.g. <link
8888 linkend="HIDE-USER-AGENT"><quote>+hide-user-agent</quote></link>,
8889 etc.), headers are suppressed or forged as determined by these actions and
8895 Now the web server starts sending its response back (i.e. typically a web
8901 First, the server headers are read and processed to determine, among other
8902 things, the MIME type (document type) and encoding. The headers are then
8903 filtered as determined by the
8904 <link linkend="CRUNCH-INCOMING-COOKIES"><quote>+crunch-incoming-cookies</quote></link>,
8905 <link linkend="SESSION-COOKIES-ONLY"><quote>+session-cookies-only</quote></link>,
8906 and <link linkend="DOWNGRADE-HTTP-VERSION"><quote>+downgrade-http-version</quote></link>
8912 If any <link linkend="FILTER"><quote>+filter</quote></link> action
8914 linkend="DEANIMATE-GIFS"><quote>+deanimate-gifs</quote></link>
8915 action applies (and the document type fits the action), the rest of the page is
8916 read into memory (up to a configurable limit). Then the filter rules (from
8917 <filename>default.filter</filename> and any other filter files) are
8918 processed against the buffered content. Filters are applied in the order
8919 they are specified in one of the filter files. Animated GIFs, if present,
8920 are reduced to either the first or last frame, depending on the action
8921 setting.The entire page, which is now filtered, is then sent by
8922 <application>Privoxy</application> back to your browser.
8925 If neither a <link linkend="FILTER"><quote>+filter</quote></link> action
8927 linkend="DEANIMATE-GIFS"><quote>+deanimate-gifs</quote></link>
8928 matches, then <application>Privoxy</application> passes the raw data through
8929 to the client browser as it becomes available.
8934 As the browser receives the now (possibly filtered) page content, it
8935 reads and then requests any URLs that may be embedded within the page
8936 source, e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
8937 frames), sounds, etc. For each of these objects, the browser issues a
8938 separate request (this is easily viewable in <application>Privoxy's</application>
8939 logs). And each such request is in turn processed just as above. Note that a
8940 complex web page will have many, many such embedded URLs. If these
8941 secondary requests are to a different server, then quite possibly a very
8942 differing set of actions is triggered.
8949 NOTE: This is somewhat of a simplistic overview of what happens with each URL
8950 request. For the sake of brevity and simplicity, we have focused on
8951 <application>Privoxy's</application> core features only.
8957 <!-- ~~~~~ New section ~~~~~ -->
8958 <sect2 id="actionsanat">
8959 <title>Troubleshooting: Anatomy of an Action</title>
8962 The way <application>Privoxy</application> applies
8963 <link linkend="ACTIONS">actions</link> and <link linkend="FILTER">filters</link>
8964 to any given URL can be complex, and not always so
8965 easy to understand what is happening. And sometimes we need to be able to
8966 <emphasis>see</emphasis> just what <application>Privoxy</application> is
8967 doing. Especially, if something <application>Privoxy</application> is doing
8968 is causing us a problem inadvertently. It can be a little daunting to look at
8969 the actions and filters files themselves, since they tend to be filled with
8970 <link linkend="regex">regular expressions</link> whose consequences are not
8975 One quick test to see if <application>Privoxy</application> is causing a problem
8976 or not, is to disable it temporarily. This should be the first troubleshooting
8977 step. See <link linkend="bookmarklets">the Bookmarklets</link> section on a quick
8978 and easy way to do this (be sure to flush caches afterward!). Looking at the
8979 logs is a good idea too. (Note that both the toggle feature and logging are
8980 enabled via <filename>config</filename> file settings, and may need to be
8981 turned <quote>on</quote>.)
8984 Another easy troubleshooting step to try is if you have done any
8985 customization of your installation, revert back to the installed
8986 defaults and see if that helps. There are times the developers get complaints
8987 about one thing or another, and the problem is more related to a customized
8988 configuration issue.
8992 <application>Privoxy</application> also provides the
8993 <ulink url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
8994 page that can show us very specifically how <application>actions</application>
8995 are being applied to any given URL. This is a big help for troubleshooting.
8999 First, enter one URL (or partial URL) at the prompt, and then
9000 <application>Privoxy</application> will tell us
9001 how the current configuration will handle it. This will not
9002 help with filtering effects (i.e. the <link
9003 linkend="FILTER"><quote>+filter</quote></link> action) from
9004 one of the filter files since this is handled very
9005 differently and not so easy to trap! It also will not tell you about any other
9006 URLs that may be embedded within the URL you are testing. For instance, images
9007 such as ads are expressed as URLs within the raw page source of HTML pages. So
9008 you will only get info for the actual URL that is pasted into the prompt area
9009 -- not any sub-URLs. If you want to know about embedded URLs like ads, you
9010 will have to dig those out of the HTML source. Use your browser's <quote>View
9011 Page Source</quote> option for this. Or right click on the ad, and grab the
9016 Let's try an example, <ulink url="http://google.com">google.com</ulink>,
9017 and look at it one section at a time in a sample configuration (your real
9018 configuration may vary):
9023 Matches for http://www.google.com:
9025 In file: default.action <guibutton>[ View ]</guibutton> <guibutton>[ Edit ]</guibutton>
9027 {+change-x-forwarded-for{block}
9028 +deanimate-gifs {last}
9029 +fast-redirects {check-decoded-url}
9030 +filter {refresh-tags}
9031 +filter {img-reorder}
9032 +filter {banners-by-size}
9034 +filter {jumping-windows}
9035 +filter {ie-exploits}
9036 +hide-from-header {block}
9037 +hide-referrer {forge}
9038 +session-cookies-only
9039 +set-image-blocker {pattern}
9042 { -session-cookies-only }
9048 In file: user.action <guibutton>[ View ]</guibutton> <guibutton>[ Edit ]</guibutton>
9049 (no matches in this file)
9054 This is telling us how we have defined our
9055 <link linkend="ACTIONS"><quote>actions</quote></link>, and
9056 which ones match for our test case, <quote>google.com</quote>.
9057 Displayed is all the actions that are available to us. Remember,
9058 the <literal>+</literal> sign denotes <quote>on</quote>. <literal>-</literal>
9059 denotes <quote>off</quote>. So some are <quote>on</quote> here, but many
9060 are <quote>off</quote>. Each example we try may provide a slightly different
9061 end result, depending on our configuration directives.
9065 is for our <filename>default.action</filename> file. The large, multi-line
9066 listing, is how the actions are set to match for all URLs, i.e. our default
9067 settings. If you look at your <quote>actions</quote> file, this would be the
9068 section just below the <quote>aliases</quote> section near the top. This
9069 will apply to all URLs as signified by the single forward slash at the end
9070 of the listing -- <quote> / </quote>.
9074 But we have defined additional actions that would be exceptions to these general
9075 rules, and then we list specific URLs (or patterns) that these exceptions
9076 would apply to. Last match wins. Just below this then are two explicit
9077 matches for <quote>.google.com</quote>. The first is negating our previous
9078 cookie setting, which was for <link
9079 linkend="SESSION-COOKIES-ONLY"><quote>+session-cookies-only</quote></link>
9080 (i.e. not persistent). So we will allow persistent cookies for google, at
9081 least that is how it is in this example. The second turns
9082 <emphasis>off</emphasis> any <link
9083 linkend="FAST-REDIRECTS"><quote>+fast-redirects</quote></link>
9084 action, allowing this to take place unmolested. Note that there is a leading
9085 dot here -- <quote>.google.com</quote>. This will match any hosts and
9086 sub-domains, in the google.com domain also, such as
9087 <quote>www.google.com</quote> or <quote>mail.google.com</quote>. But it would not
9088 match <quote>www.google.de</quote>! So, apparently, we have these two actions
9089 defined as exceptions to the general rules at the top somewhere in the lower
9090 part of our <filename>default.action</filename> file, and
9091 <quote>google.com</quote> is referenced somewhere in these latter sections.
9095 Then, for our <filename>user.action</filename> file, we again have no hits.
9096 So there is nothing google-specific that we might have added to our own, local
9097 configuration. If there was, those actions would over-rule any actions from
9098 previously processed files, such as <filename>default.action</filename>.
9099 <filename>user.action</filename> typically has the last word. This is the
9100 best place to put hard and fast exceptions,
9104 And finally we pull it all together in the bottom section and summarize how
9105 <application>Privoxy</application> is applying all its <quote>actions</quote>
9106 to <quote>google.com</quote>:
9117 +change-x-forwarded-for{block}
9118 -client-header-filter{hide-tor-exit-notation}
9119 -content-type-overwrite
9120 -crunch-client-header
9121 -crunch-if-none-match
9122 -crunch-incoming-cookies
9123 -crunch-outgoing-cookies
9124 -crunch-server-header
9125 +deanimate-gifs {last}
9126 -downgrade-http-version
9129 -filter {content-cookies}
9130 -filter {all-popups}
9131 -filter {banners-by-link}
9132 -filter {tiny-textforms}
9133 -filter {frameset-borders}
9134 -filter {demoronizer}
9135 -filter {shockwave-flash}
9136 -filter {quicktime-kioskmode}
9138 -filter {crude-parental}
9139 -filter {site-specifics}
9140 -filter {js-annoyances}
9141 -filter {html-annoyances}
9142 +filter {refresh-tags}
9143 -filter {unsolicited-popups}
9144 +filter {img-reorder}
9145 +filter {banners-by-size}
9147 +filter {jumping-windows}
9148 +filter {ie-exploits}
9155 -handle-as-empty-document
9157 -hide-accept-language
9158 -hide-content-disposition
9159 +hide-from-header {block}
9160 -hide-if-modified-since
9161 +hide-referrer {forge}
9164 -overwrite-last-modified
9165 -prevent-compression
9167 -server-header-filter{xml-to-html}
9168 -server-header-filter{html-to-xml}
9169 -session-cookies-only
9170 +set-image-blocker {pattern} </screen>
9174 Notice the only difference here to the previous listing, is to
9175 <quote>fast-redirects</quote> and <quote>session-cookies-only</quote>,
9176 which are activated specifically for this site in our configuration,
9177 and thus show in the <quote>Final Results</quote>.
9181 Now another example, <quote>ad.doubleclick.net</quote>:
9187 { +block{Domains starts with "ad"} }
9190 { +block{Domain contains "ad"} }
9193 { +block{Doubleclick banner server} +handle-as-image }
9194 .[a-vx-z]*.doubleclick.net
9199 We'll just show the interesting part here - the explicit matches. It is
9200 matched three different times. Two <quote>+block{}</quote> sections,
9201 and a <quote>+block{} +handle-as-image</quote>,
9202 which is the expanded form of one of our aliases that had been defined as:
9203 <quote>+block-as-image</quote>. (<link
9204 linkend="ALIASES"><quote>Aliases</quote></link> are defined in
9205 the first section of the actions file and typically used to combine more
9210 Any one of these would have done the trick and blocked this as an unwanted
9211 image. This is unnecessarily redundant since the last case effectively
9212 would also cover the first. No point in taking chances with these guys
9213 though ;-) Note that if you want an ad or obnoxious
9214 URL to be invisible, it should be defined as <quote>ad.doubleclick.net</quote>
9215 is done here -- as both a <link
9216 linkend="BLOCK"><quote>+block{}</quote></link>
9217 <emphasis>and</emphasis> an
9218 <link linkend="HANDLE-AS-IMAGE"><quote>+handle-as-image</quote></link>.
9219 The custom alias <quote><literal>+block-as-image</literal></quote> just
9220 simplifies the process and make it more readable.
9224 One last example. Let's try <quote>http://www.example.net/adsl/HOWTO/</quote>.
9225 This one is giving us problems. We are getting a blank page. Hmmm ...
9231 Matches for http://www.example.net/adsl/HOWTO/:
9233 In file: default.action <guibutton>[ View ]</guibutton> <guibutton>[ Edit ]</guibutton>
9237 +change-x-forwarded-for{block}
9238 -client-header-filter{hide-tor-exit-notation}
9239 -content-type-overwrite
9240 -crunch-client-header
9241 -crunch-if-none-match
9242 -crunch-incoming-cookies
9243 -crunch-outgoing-cookies
9244 -crunch-server-header
9246 -downgrade-http-version
9247 +fast-redirects {check-decoded-url}
9249 -filter {content-cookies}
9250 -filter {all-popups}
9251 -filter {banners-by-link}
9252 -filter {tiny-textforms}
9253 -filter {frameset-borders}
9254 -filter {demoronizer}
9255 -filter {shockwave-flash}
9256 -filter {quicktime-kioskmode}
9258 -filter {crude-parental}
9259 -filter {site-specifics}
9260 -filter {js-annoyances}
9261 -filter {html-annoyances}
9262 +filter {refresh-tags}
9263 -filter {unsolicited-popups}
9264 +filter {img-reorder}
9265 +filter {banners-by-size}
9267 +filter {jumping-windows}
9268 +filter {ie-exploits}
9275 -handle-as-empty-document
9277 -hide-accept-language
9278 -hide-content-disposition
9279 +hide-from-header{block}
9280 +hide-referer{forge}
9282 -overwrite-last-modified
9283 +prevent-compression
9285 -server-header-filter{xml-to-html}
9286 -server-header-filter{html-to-xml}
9287 +session-cookies-only
9288 +set-image-blocker{blank} }
9291 { +block{Path contains "ads".} +handle-as-image }
9297 Ooops, the <quote>/adsl/</quote> is matching <quote>/ads</quote> in our
9298 configuration! But we did not want this at all! Now we see why we get the
9299 blank page. It is actually triggering two different actions here, and
9300 the effects are aggregated so that the URL is blocked, and &my-app; is told
9301 to treat the block as if it were an image. But this is, of course, all wrong.
9302 We could now add a new action below this (or better in our own
9303 <filename>user.action</filename> file) that explicitly
9304 <emphasis>un</emphasis> blocks (
9305 <link linkend="BLOCK"><quote>{-block}</quote></link>) paths with
9306 <quote>adsl</quote> in them (remember, last match in the configuration
9307 wins). There are various ways to handle such exceptions. Example:
9319 Now the page displays ;-)
9320 Remember to flush your browser's caches when making these kinds of changes to
9321 your configuration to insure that you get a freshly delivered page! Or, try
9322 using <literal>Shift+Reload</literal>.
9326 But now what about a situation where we get no explicit matches like
9333 { +block{Path starts with "ads".} +handle-as-image }
9339 That actually was very helpful and pointed us quickly to where the problem
9340 was. If you don't get this kind of match, then it means one of the default
9341 rules in the first section of <filename>default.action</filename> is causing
9342 the problem. This would require some guesswork, and maybe a little trial and
9343 error to isolate the offending rule. One likely cause would be one of the
9344 <link linkend="FILTER"><quote>+filter</quote></link> actions.
9345 These tend to be harder to troubleshoot.
9346 Try adding the URL for the site to one of aliases that turn off
9347 <link linkend="FILTER"><quote>+filter</quote></link>:
9355 .worldpay.com # for quietpc.com
9363 <quote><literal>{ shop }</literal></quote> is an <quote>alias</quote> that expands to
9364 <quote><literal>{ -filter -session-cookies-only }</literal></quote>.
9365 Or you could do your own exception to negate filtering:
9373 # Disable ALL filter actions for sites in this section
9381 This would turn off all filtering for these sites. This is best
9382 put in <filename>user.action</filename>, for local site
9383 exceptions. Note that when a simple domain pattern is used by itself (without
9384 the subsequent path portion), all sub-pages within that domain are included
9385 automatically in the scope of the action.
9389 Images that are inexplicably being blocked, may well be hitting the
9390 <link linkend="FILTER-BANNERS-BY-SIZE"><quote>+filter{banners-by-size}</quote></link>
9392 that images of certain sizes are ad banners (works well
9393 <emphasis>most of the time</emphasis> since these tend to be standardized).
9397 <quote><literal>{ fragile }</literal></quote> is an alias that disables most
9398 actions that are the most likely to cause trouble. This can be used as a
9399 last resort for problem sites.
9405 # Handle with care: easy to break
9407 mybank.example.com</screen>
9412 <emphasis>Remember to flush caches!</emphasis> Note that the
9413 <literal>mail.google</literal> reference lacks the TLD portion (e.g.
9414 <quote>.com</quote>). This will effectively match any TLD with
9415 <literal>google</literal> in it, such as <literal>mail.google.de.</literal>,
9419 If this still does not work, you will have to go through the remaining
9420 actions one by one to find which one(s) is causing the problem.
9429 This program is free software; you can redistribute it
9430 and/or modify it under the terms of the GNU General
9431 Public License as published by the Free Software
9432 Foundation; either version 2 of the License, or (at
9433 your option) any later version.
9435 This program is distributed in the hope that it will
9436 be useful, but WITHOUT ANY WARRANTY; without even the
9437 implied warranty of MERCHANTABILITY or FITNESS FOR A
9438 PARTICULAR PURPOSE. See the GNU General Public
9439 License for more details.
9441 The GNU General Public License should be included with
9442 this file. If not, you can view it at
9443 http://www.gnu.org/copyleft/gpl.html
9444 or write to the Free Software Foundation, Inc.,
9445 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
projects / privoxy.git / blob