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 "UNRELEASED">
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 2.156 2013/01/05 22:56:31 ler762 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; 2001-2011 by
59 <ulink url="http://www.privoxy.org/">Privoxy Developers</ulink>
63 <pubdate>$Id: user-manual.sgml,v 2.156 2013/01/05 22:56:31 ler762 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-pack-rpm"><title>Red Hat and Fedora RPMs</title>
187 RPMs can be installed with <literal>rpm -Uvh privoxy-&p-version;-1.rpm</literal>,
188 and will use <filename>/etc/privoxy</filename> for the location
189 of configuration files.
193 Note that on Red Hat, <application>Privoxy</application> will
194 <emphasis>not</emphasis> be automatically started on system boot. You will
195 need to enable that using <command>chkconfig</command>,
196 <command>ntsysv</command>, or similar methods.
200 If you have problems with failed dependencies, try rebuilding the SRC RPM:
201 <literal>rpm --rebuild privoxy-&p-version;-1.src.rpm</literal>. This
202 will use your locally installed libraries and RPM version.
206 Also note that if you have a <application>Junkbuster</application> RPM installed
207 on your system, you need to remove it first, because the packages conflict.
208 Otherwise, RPM will try to remove <application>Junkbuster</application>
209 automatically if found, before installing <application>Privoxy</application>.
213 <!-- ~~~~~ New section ~~~~~ -->
214 <sect3 id="installation-deb"><title>Debian and Ubuntu</title>
216 DEBs can be installed with <literal>apt-get install privoxy</literal>,
217 and will use <filename>/etc/privoxy</filename> for the location of
222 <!-- ~~~~~ New section ~~~~~ -->
223 <sect3 id="installation-pack-win"><title>Windows</title>
226 Just double-click the installer, which will guide you through
227 the installation process. You will find the configuration files
228 in the same directory as you installed <application>Privoxy</application> in.
231 Version 3.0.5 beta introduced full <application>Windows</application> service
232 functionality. On Windows only, the <application>Privoxy</application>
233 program has two new command line arguments to install and uninstall
234 <application>Privoxy</application> as a <emphasis>service</emphasis>.
238 <term>Arguments:</term>
241 <replaceable class="parameter">--install</replaceable>[:<replaceable class="parameter">service_name</replaceable>]
244 <replaceable class="parameter">--uninstall</replaceable>[:<replaceable class="parameter">service_name</replaceable>]
250 After invoking <application>Privoxy</application> with
251 <command>--install</command>, you will need to bring up the
252 <application>Windows</application> service console to assign the user you
253 want <application>Privoxy</application> to run under, and whether or not you
254 want it to run whenever the system starts. You can start the
255 <application>Windows</application> services console with the following
256 command: <command>services.msc</command>. If you do not take the manual step
257 of modifying <application>Privoxy's</application> service settings, it will
258 not start. Note too that you will need to give Privoxy a user account that
259 actually exists, or it will not be permitted to
260 write to its log and configuration files.
265 <!-- ~~~~~ New section ~~~~~ -->
266 <sect3 id="installation-pack-bintgz"><title>Solaris <!--, NetBSD, HP-UX--></title>
269 Create a new directory, <literal>cd</literal> to it, then unzip and
270 untar the archive. For the most part, you'll have to figure out where
271 things go. <!-- FIXME, more info needed? -->
275 <!-- ~~~~~ New section ~~~~~ -->
276 <sect3 id="installation-os2"><title>OS/2</title>
279 First, make sure that no previous installations of
280 <application>Junkbuster</application> and / or
281 <application>Privoxy</application> are left on your
282 system. Check that no <application>Junkbuster</application>
283 or <application>Privoxy</application> objects are in
289 Then, just double-click the WarpIN self-installing archive, which will
290 guide you through the installation process. A shadow of the
291 <application>Privoxy</application> executable will be placed in your
292 startup folder so it will start automatically whenever OS/2 starts.
296 The directory you choose to install <application>Privoxy</application>
297 into will contain all of the configuration files.
301 <!-- ~~~~~ New section ~~~~~ -->
302 <sect3 id="installation-mac"><title>Mac OS X</title>
304 Installation instructions for the OS X platform depend upon whether
305 you downloaded a ready-built installation package (.pkg or .mpkg) or have
306 downloaded the source code.
309 <sect3 renderas="sect4" id="OS-X-install-from-package">
310 <title>Installation from ready-built package</title>
312 The downloaded file will either be a .pkg (for OS X 10.5 upwards) or a bzipped
313 .mpkg file (for OS X 10.4). The former can be double-clicked as is and the
314 installation will start; double-clicking the latter will unzip the .mpkg file
315 which can then be double-clicked to commence the installation.
318 The privoxy service will automatically start after a successful installation
319 (and thereafter every time your computer starts up) however you will need to
320 configure your web browser(s) to use it. To do so, configure them to use a
321 proxy for HTTP and HTTPS at the address 127.0.0.1:8118.
324 To prevent the privoxy service from automatically starting when your computer
325 starts up, remove or rename the file <literal>/Library/LaunchDaemons/org.ijbswa.privoxy.plist</literal>
326 (on OS X 10.5 and higher) or the folder named
327 <literal>/Library/StartupItems/Privoxy</literal> (on OS X 10.4 'Tiger').
330 To manually start or stop the privoxy service, use the scripts startPrivoxy.sh
331 and stopPrivoxy.sh supplied in /Applications/Privoxy. They must be run from an
332 administrator account, using sudo.
335 To uninstall, run /Applications/Privoxy/uninstall.command as sudo from an
336 administrator account.
339 <sect3 renderas="sect4" id="OS-X-install-from-source">
340 <title>Installation from source</title>
342 To build and install the Privoxy source code on OS X you will need to obtain
343 the macsetup module from the Privoxy Sourceforge CVS repository (refer to
344 Sourceforge help for details of how to set up a CVS client to have read-only
345 access to the repository). This module contains scripts that leverage the usual
346 open-source tools (available as part of Apple's free of charge Xcode
347 distribution or via the usual open-source software package managers for OS X
348 (MacPorts, Homebrew, Fink etc.) to build and then install the privoxy binary
349 and associated files. The macsetup module's README file contains complete
350 instructions for its use.
353 The privoxy service will automatically start after a successful installation
354 (and thereafter every time your computer starts up) however you will need to
355 configure your web browser(s) to use it. To do so, configure them to use a
356 proxy for HTTP and HTTPS at the address 127.0.0.1:8118.
359 To prevent the privoxy service from automatically starting when your computer
360 starts up, remove or rename the file <literal>/Library/LaunchDaemons/org.ijbswa.privoxy.plist</literal>
361 (on OS X 10.5 and higher) or the folder named
362 <literal>/Library/StartupItems/Privoxy</literal> (on OS X 10.4 'Tiger').
365 To manually start or stop the privoxy service, use the Privoxy Utility
366 for Mac OS X (also part of the macsetup module). This application can start
367 and stop the privoxy service and display its log and configuration files.
370 To uninstall, run the macsetup module's uninstall.sh as sudo from an
371 administrator account.
375 <!-- ~~~~~ New section ~~~~~ -->
376 <sect3 id="installation-amiga"><title>AmigaOS</title>
378 Copy and then unpack the <filename>lha</filename> archive to a suitable location.
379 All necessary files will be installed into <application>Privoxy</application>
380 directory, including all configuration and log files. To uninstall, just
381 remove this directory.
385 <!-- ~~~~~ New section ~~~~~ -->
386 <sect3 id="installation-tbz"><title>FreeBSD</title>
389 Privoxy is part of FreeBSD's Ports Collection, you can build and install
390 it with <literal>cd /usr/ports/www/privoxy; make install clean</literal>.
393 If you don't use the ports, you can fetch and install
394 the package with <literal>pkg_add -r privoxy</literal>.
397 The port skeleton and the package can also be downloaded from the
398 <ulink url="https://sourceforge.net/project/showfiles.php?group_id=11118">File Release
399 Page</ulink>, but there's no reason to use them unless you're interested in the
400 beta releases which are only available there.
404 <!-- ~~~~~ New section ~~~~~ -->
405 <sect3 id="installattion-gentoo"><title>Gentoo</title>
407 Gentoo source packages (Ebuilds) for <application>Privoxy</application> are
408 contained in the Gentoo Portage Tree (they are not on the download page,
409 but there is a Gentoo section, where you can see when a new
410 <application>Privoxy</application> Version is added to the Portage Tree).
413 Before installing <application>Privoxy</application> under Gentoo just do
414 first <literal>emerge --sync</literal> to get the latest changes from the
415 Portage tree. With <literal>emerge privoxy</literal> you install the latest
419 Configuration files are in <filename>/etc/privoxy</filename>, the
420 documentation is in <filename>/usr/share/doc/privoxy-&p-version;</filename>
421 and the Log directory is in <filename>/var/log/privoxy</filename>.
427 <!-- ~~~~~ New section ~~~~~ -->
428 <sect2 id="installation-source"><title>Building from Source</title>
431 The most convenient way to obtain the <application>Privoxy</application> sources
432 is to download the source tarball from our
433 <ulink url="http://sourceforge.net/project/showfiles.php?group_id=11118&package_id=10571">project download
438 If you like to live on the bleeding edge and are not afraid of using
439 possibly unstable development versions, you can check out the up-to-the-minute
440 version directly from <ulink url="http://sourceforge.net/cvs/?group_id=11118">the
441 CVS repository</ulink>.
443 deprecated...out of business.
444 or simply download <ulink
445 url="http://cvs.sourceforge.net/cvstarballs/ijbswa-cvsroot.tar.bz2">the nightly CVS
450 <!-- include buildsource.sgml boilerplate: -->
452 <!-- end boilerplate -->
455 <!-- ~~~~~ New section ~~~~~ -->
456 <sect2 id="installation-keepupdated"><title>Keeping your Installation Up-to-Date</title>
458 As user feedback comes in and development continues, we will make updated versions
459 of both the main <link linkend="actions-file">actions file</link> (as a <ulink
460 url="http://sourceforge.net/project/showfiles.php?group_id=11118&release_id=103670">separate
461 package</ulink>) and the software itself (including the actions file) available for
466 If you wish to receive an email notification whenever we release updates of
467 <application>Privoxy</application> or the actions file, <ulink
468 url="http://lists.sourceforge.net/lists/listinfo/ijbswa-announce/">subscribe
469 to our announce mailing list</ulink>, ijbswa-announce@lists.sourceforge.net.
473 In order not to lose your personal changes and adjustments when updating
474 to the latest <literal>default.action</literal> file we <emphasis>strongly
475 recommend</emphasis> that you use <literal>user.action</literal> and
476 <literal>user.filter</literal> for your local
477 customizations of <application>Privoxy</application>. See the <link
478 linkend="actions-file">Chapter on actions files</link> for details.
486 <!-- ~ End section ~ -->
488 <!-- ~~~~~ New section ~~~~~ -->
489 <sect1 id="whatsnew">
490 <title>What's New in this Release</title>
492 <application>Privoxy 3.0.19</application> is a stable release.
493 The changes since 3.0.18 stable are:
504 Prevent a segmentation fault when de-chunking buffered content.
505 It could be triggered by malicious web servers if Privoxy was
506 configured to filter the content and running on a platform
507 where SIZE_T_MAX isn't larger than UINT_MAX, which probably
508 includes most 32-bit systems. On those platforms, all Privoxy
509 versions before 3.0.19 appear to be affected.
510 To be on the safe side, this bug should be presumed to allow
511 code execution as proving that it doesn't seems unrealistic.
516 Do not expect a response from the SOCKS4/4A server until it
517 got something to respond to. This regression was introduced
518 in 3.0.18 and prevented the SOCKS4/4A negotiation from working.
519 Reported by qqqqqw in #3459781.
527 General improvements:
531 Fix an off-by-one in an error message about connect failures.
536 Use a GNUMakefile variable for the webserver root directory and
537 update the path. Sourceforge changed it which broke various
543 Update the CODE_STATUS description.
553 The following changes were made between 3.0.17 and 3.0.18:
564 If a generated redirect URL contains characters RFC 3986 doesn't
565 permit, they are (re)encoded. Not doing this makes Privoxy versions
566 from 3.0.5 to 3.0.17 susceptible to HTTP response splitting (CWE-113)
567 attacks if the +fast-redirects{check-decoded-url} action is used.
572 Fix a logic bug that could cause Privoxy to reuse a server
573 socket after it got tainted by a server-header-tagger-induced
574 block that was triggered before the whole server response had
575 been read. If keep-alive was enabled and the request following
576 the blocked one was to the same host and using the same forwarding
577 settings, Privoxy would send it on the tainted server socket.
578 While the server would simply treat it as a pipelined request,
579 Privoxy would later on fail to properly parse the server's
580 response as it would try to parse the unread data from the
581 first response as server headers for the second one.
582 Regression introduced in 3.0.17.
587 When implying keep-alive in client_connection(), remember that
588 the client didn't. Fixes a regression introduced in 3.0.13 that
589 would cause Privoxy to wait for additional client requests after
590 receiving a HTTP/1.1 request with "Connection: close" set
591 and connection sharing enabled.
592 With clients which terminates the client connection after detecting
593 that the whole body has been received it doesn't really matter,
594 but with clients that don't the connection would be kept open until
600 Fix a subtle race condition between prepare_csp_for_next_request()
601 and sweep(). A thread preparing itself for the next client request
602 could briefly appear to be inactive.
603 If all other threads were already using more recent files,
604 the thread could get its files swept away under its feet.
605 So far this has only been reproduced while stress testing in
606 valgrind while touching action files in a loop. It's unlikely
607 to have caused any actual problems in the real world.
612 Disable filters if SDCH compression is used unless filtering is forced.
613 If SDCH was combined with a supported compression algorithm, Privoxy
614 previously could try to decompress it and ditch the Content-Encoding
615 header even though the SDCH compression wasn't dealt with.
616 Reported by zebul666 in #3225863.
621 Make a copy of the --user value and only mess with that when splitting
622 user and group. On some operating systems modifying the value directly
623 is reflected in the output of ps and friends and can be misleading.
624 Reported by zepard in #3292710.
629 If forwarded-connect-retries is set, only retry if Privoxy is actually
630 forwarding the request. Previously direct connections would be retried
636 Fixed a small memory leak when retrying connections with IPv6
642 Remove an incorrect assertion in compile_dynamic_pcrs_job_list()
643 It could be triggered by a pcrs job with an invalid pcre
644 pattern (for example one that contains a lone quantifier).
649 If the --user argument user[.group] contains a dot, always bail out
650 if no group has been specified. Previously the intended, but undocumented
651 (and apparently untested), behaviour was to try interpreting the whole
652 argument as user name, but the detection was flawed and checked for '0'
653 instead of '\0', thus merely preventing group names beginning with a zero.
658 In html_code_map[], use a numeric character reference instead of '
659 which wasn't standardized before XHTML 1.0.
664 Fix an invalid free when compiled with FEATURE_GRACEFUL_TERMINATION
665 and shut down through http://config.privoxy.org/die
670 In get_actions(), fix the "temporary" backwards compatibility hack
671 to accept block actions without reason.
672 It also covered other actions that should be rejected as invalid.
673 Reported by Billy Crook.
681 General improvements:
685 Privoxy can (re)compress buffered content before delivering
686 it to the client. Disabled by default as most users wouldn't
692 The +fast-redirects{check-decoded-url} action checks URL
693 segments separately. If there are other parameters behind
694 the redirect URL, this makes it unnecessary to cut them off
695 by additionally using a +redirect{} pcrs command.
696 Initial patch submitted by Jamie Zawinski in #3429848.
701 When loading action sections, verify that the referenced filters
702 exist. Currently missing filters only result in an error message,
703 but eventually the severity will be upgraded to fatal.
708 Allow to bind to multiple separate addresses.
709 Patch set submitted by Petr Pisar in #3354485.
714 Set socket_error to errno if connecting fails in rfc2553_connect_to().
715 Previously rejected direct connections could be incorrectly reported
716 as DNS issues if Privoxy was compiled with IPv6 support.
721 Adjust url_code_map[] so spaces are replaced with %20 instead of '+'
722 While '+' can be used by client's submitting form data, this is not
723 actually what Privoxy is using the lookups for. This is more of a
724 cosmetic issue and doesn't fix any known problems.
729 When compiled without FEATURE_FAST_REDIRECTS, do not silently
730 ignore +fast-redirect{} directives
735 Added a workaround for GNU libc's strptime() reporting negative
736 year values when the parsed year is only specified with two digits.
737 On affected systems cookies with such a date would not be turned
738 into session cookies by the +session-cookies-only action.
739 Reported by Vaeinoe in #3403560
744 Fixed bind failures with certain GNU libc versions if no non-loopback
745 IP address has been configured on the system. This is mainly an issue
746 if the system is using DHCP and Privoxy is started before the network
747 is completely configured.
748 Reported by Raphael Marichez in #3349356.
749 Additional insight from Petr Pisar.
754 Privoxy log messages now use the ISO 8601 date format %Y-%m-%d.
755 It's only slightly longer than the old format, but contains
756 the full date including the year and allows sorting by date
757 (when grepping in multiple log files) without hassle.
762 In get_last_url(), do not bother trying to decode URLs that do
763 not contain at least one '%' sign. It reduces the log noise and
764 a number of unnecessary memory allocations.
769 In case of SOCKS5 failures, dump the socks response in the log message.
774 Simplify the signal setup in main().
779 Streamline socks5_connect() slightly.
784 In socks5_connect(), require a complete socks response from the server.
785 Previously Privoxy didn't care how much data the server response
786 contained as long as the first two bytes contained the expected
787 values. While at it, shrink the buffer size so Privoxy can't read
788 more than a whole socks response.
793 In chat(), do not bother to generate a client request in case of
794 direct CONNECT requests. It will not be used anyway.
799 Reduce server_last_modified()'s stack size.
804 Shorten get_http_time() by using strftime().
809 Constify the known_http_methods pointers in unknown_method().
814 Constify the time_formats pointers in parse_header_time().
819 Constify the formerly_valid_actions pointers in action_used_to_be_valid().
824 Introduce a GNUMakefile MAN_PAGE variable that defaults to privoxy.1.
825 The Debian package uses section 8 for the man page and this
826 should simplify the patch.
831 Deduplicate the INADDR_NONE definition for Solaris by moving it to jbsockets.h
836 In block_url(), ditch the obsolete workaround for ancient Netscape versions
837 that supposedly couldn't properly deal with status code 403.
842 Remove a useless NULL pointer check in load_trustfile().
847 Remove two useless NULL pointer checks in load_one_re_filterfile().
852 Change url_code_map[] from an array of pointers to an array of arrays
853 It removes an unnecessary layer of indirection and on 64bit system reduces
854 the size of the binary a bit.
859 Fix various typos. Fixes taken from Debian's 29_typos.dpatch by Roland Rosenfeld.
864 Add a dok-tidy GNUMakefile target to clean up the messy HTML
865 generated by the other dok targets.
870 GNUisms in the GNUMakefile have been removed.
875 Change the HTTP version in static responses to 1.1
880 Synced config.sub and config.guess with upstream
881 2011-11-11/386c7218162c145f5f9e1ff7f558a3fbb66c37c5.
886 Add a dedicated function to parse the values of toggles. Reduces duplicated
887 code in load_config() and provides better error handling. Invalid or missing
888 toggle values are now a fatal error instead of being silently ignored.
893 Terminate HTML lines in static error messages with \n instead of \r\n.
898 Simplify cgi_error_unknown() a bit.
903 In LogPutString(), don't bother looking at pszText when not
904 actually logging anything.
909 Change ssplit()'s fourth parameter from int to size_t.
910 Fixes a clang complaint.
915 Add a warning that the statistics currently can't be trusted.
916 Mention Privoxy-Log-Parser's --statistics option as
917 an alternative for the time being.
922 In rfc2553_connect_to(), start setting cgi->error_message on error.
927 Change the expected status code returned for http://p.p/die depending
928 on whether or not FEATURE_GRACEFUL_TERMINATION is available.
933 In cgi_die(), mark the client connection for closing.
934 If the client will fetch the style sheet through another connection
935 it gets the main thread out of the accept() state and should thus
936 trigger the actual shutdown.
941 Add a proper CGI message for cgi_die().
946 Don't enforce a logical line length limit in read_config_line().
951 Slightly refactor server_last_modified() to remove useless gmtime*() calls.
956 In get_content_type(), also recognize '.jpeg' as JPEG extension.
961 Add '.png' to the list of recognized file extensions in get_content_type().
966 In block_url(), consistently use the block reason "Request blocked by Privoxy"
967 In two places the reason was "Request for blocked URL" which hides the
968 fact that the request got blocked by Privoxy and isn't necessarily
969 correct as the block may be due to tags.
974 In listen_loop(), reload the configuration files after accepting
975 a new connection instead of before.
976 Previously the first connection that arrived after a configuration
977 change would still be handled with the old configuration.
982 In chat()'s receive-data loop, skip a client socket check if
983 the socket will be written to right away anyway. This can
984 increase the transfer speed for unfiltered content on fast
990 The socket timeout is used for SOCKS negotiations as well which
991 previously couldn't timeout.
996 Don't keep the client connection alive if any configuration file
997 changed since the time the connection came in. This is closer to
998 Privoxy's behaviour before keep-alive support for client connection
999 has been added and also less confusing in general.
1004 Treat all Content-Type header values containing the pattern
1005 'script' as a sign of text. Reported by pribog in #3134970.
1013 Action file improvements:
1017 Moved the site-specific block pattern section below the one for the
1018 generic patterns so for requests that are matched in both, the block
1019 reason for the domain is shown which is usually more useful than showing
1020 the one for the generic pattern.
1025 Remove -prevent-compression from the fragile alias. It's no longer
1026 used anywhere by default and isn't known to break stuff anyway.
1031 Add a (disabled) section to block various Facebook tracking URLs.
1032 Reported by Dan Stahlke in #3421764.
1037 Add a (disabled) section to rewrite and redirect click-tracking
1038 URLs used on news.google.com.
1039 Reported by Dan Stahlke in #3421755.
1044 Unblock linuxcounter.net/.
1045 Reported by Dan Stahlke in #3422612.
1050 Block 'www91.intel.com/' which is used by Omniture.
1051 Reported by Adam Piggott in #3167370.
1056 Disable the handle-as-empty-doc-returns-ok option and mark it as deprecated.
1057 Reminded by tceverling in #2790091.
1062 Add ".ivwbox.de/" to the "Cross-site user tracking" section.
1063 Reported by Nettozahler in #3172525.
1068 Unblock and fast-redirect ".awin1.com/.*=http://".
1069 Reported by Adam Piggott in #3170921.
1074 Block "b.collective-media.net/".
1079 Widen the Debian popcon exception to "qa.debian.org/popcon".
1080 Seen in Debian's 05_default_action.dpatch by Roland Rosenfeld.
1085 Block ".gemius.pl/" which only seems to be used for user tracking.
1086 Reported by johnd16 in #3002731. Additional input from Lee and movax.
1091 Disable banners-by-size filters for '.thinkgeek.com/'.
1092 The filter only seems to catch pictures of the inventory.
1097 Block requests for 'go.idmnet.bbelements.com/please/showit/'.
1098 Reported by kacperdominik in #3372959.
1103 Unblock adainitiative.org/.
1108 Add a fast-redirects exception for '.googleusercontent.com/.*=cache'.
1113 Add a fast-redirects exception for webcache.googleusercontent.com/.
1118 Unblock http://adassier.wordpress.com/ and http://adassier.files.wordpress.com/.
1126 Filter file improvements:
1130 Let the yahoo filter hide '.ads'.
1135 Let the msn filter hide overlay ads for Facebook 'likes' in search
1136 results and elements with the id 's_notf_div'. They only seem to be
1137 used to advertise site 'enhancements'.
1142 Let the js-events filter additionally disarm setInterval().
1143 Suggested by dg1727 in #3423775.
1151 Documentation improvements:
1155 Clarify the effect of compiling Privoxy with zlib support.
1156 Suggested by dg1727 in #3423782.
1161 Point out that the SourceForge messaging system works like a black
1162 hole and should thus not be used to contact individual developers.
1167 Mention some of the problems one can experience when not explicitly
1168 configuring an IP addresses as listen address.
1173 Explicitly mention that hostnames can be used instead of IP addresses
1174 for the listen-address, that only the first address returned will be
1175 used and what happens if the address is invalid.
1176 Requested by Calestyo in #3302213.
1184 Log message improvements:
1188 If only the server connection is kept alive, do not pretend to
1189 wait for a new client request.
1194 Remove a superfluous log message in forget_connection().
1199 In chat(), properly report missing server responses as such
1200 instead of calling them empty.
1205 In forwarded_connect(), fix a log message nobody should ever see.
1210 Fix a log message in socks5_connect(), a failed write operation
1211 was logged as failed read operation.
1216 Let load_one_actions_file() properly complain about a missing
1217 '{' at the beginning of the file.
1218 Simply stating that a line is invalid isn't particularly helpful.
1223 Do not claim to listen on a socket until Privoxy actually does.
1224 Patch submitted by Petr Pisar #3354485
1229 Prevent a duplicated LOG_LEVEL_CLF message when sending out
1230 the "no-server-data" response.
1235 Also log the client socket when dropping a connection.
1240 Include the destination host in the 'Request ... marked for
1241 blocking. limit-connect{...} doesn't allow CONNECT ...' message
1242 Patch submitted by Saperski in #3296250.
1247 Prevent a duplicated log message if none of the resolved IP
1248 addresses were reachable.
1253 In connect_to(), do not pretend to retry if forwarded-connect-retries
1259 When a specified user or group can't be found, put the name in
1260 single-quotes when logging it.
1265 In rfc2553_connect_to(), explain getnameinfo() errors better.
1270 Remove a useless log message in chat().
1275 When retrying to connect, also log the maximum number of connection
1281 Rephrase a log message in compile_dynamic_pcrs_job_list().
1282 Divide the error code and its meaning with a colon. Call the pcrs
1283 job dynamic and not the filter. Filters may contain dynamic and
1284 non-dynamic pcrs jobs at the same time. Only mention the name of
1285 the filter or tagger, but don't claim it's a filter when it could
1291 In a fatal error message in load_one_actions_file(), cover both
1292 URL and TAG patterns.
1297 In pcrs_strerror(), properly report unknown positive error code
1298 values as such. Previously they were handled like 0 (no error).
1303 In compile_dynamic_pcrs_job_list(), also log the actual error code as
1304 pcrs_strerror() doesn't handle all errors reported by pcre.
1309 Don't bother trying to continue chatting if the client didn't ask for it.
1310 Reduces log noise a bit.
1315 Make two fatal error message in load_one_actions_file() more descriptive.
1320 In cgi_send_user_manual(), log when rejecting a file name due to '/' or '..'.
1325 In load_file(), log a message if opening a file failed.
1326 The CGI error message alone isn't too helpful.
1331 In connection_destination_matches(), improve two log messages
1332 to help understand why the destinations don't match.
1337 Rephrase a log message in serve(). Client request arrival
1338 should be differentiated from closed client connections now.
1343 In serve(), log if a client connection isn't reused due to a
1344 configuration file change.
1349 Let mark_server_socket_tainted() always mark the server socket tainted,
1350 just don't talk about it in cases where it has no effect. It doesn't change
1351 Privoxy's behaviour, but makes understanding the log file easier.
1363 Added a --disable-ipv6-support switch for platforms where support
1364 is detected but doesn't actually work.
1369 Do not check for the existence of strerror() and memmove() twice
1374 Remove a useless test for setpgrp(2). Privoxy doesn't need it and
1375 it can cause problems when cross-compiling.
1380 Rename the --disable-acl-files switch to --disable-acl-support.
1381 Since about 2001, ACL directives are specified in the standard
1387 Update the URL of the 'Removing outdated PCRE version after the
1388 next stable release' posting. The old URL stopped working after
1389 one of SF's recent site "optimizations". Reported by Han Liu.
1397 Privoxy-Regression-Test:
1401 Added --shuffle-tests option to increase the chances of detection race conditions.
1406 Added a --local-test-file option that allows to use Privoxy-Regression-Test without Privoxy.
1411 Added tests for missing socks4 and socks4a forwarders.
1416 The --privoxy-address option now works with IPv6 addresses containing brackets, too.
1421 Perform limited sanity checks for parameters that are supposed to have numerical values.
1426 Added a --sleep-time option to specify a number of seconds to
1427 sleep between tests, defaults to 0.
1432 Disable the range-requests tagger for tests that break if it's enabled.
1437 Log messages use the ISO 8601 date format %Y-%m-%d.
1442 Fix spelling in two error messages.
1447 In the --help output, include a list of supported tests and their default levels.
1452 Adjust the tests to properly deal with FEATURE_TOGGLE being disabled.
1464 Perform limited sanity checks for command line parameters that
1465 are supposed to have numerical values.
1470 Implement a --unbreak-lines-only option to try to revert MUA breakage.
1475 Accept and highlight: Added header: Content-Encoding: deflate
1480 Accept and highlight: Compressed content from 29258 to 8630 bytes.
1485 Accept and highlight: Client request arrived in time on socket 21.
1490 Highlight: Didn't receive data in time: a.fsdn.com:443
1495 Accept log messages with ISO 8601 time stamps, too.
1507 Bump generated Firefox version to 8.0.
1512 Only randomize the release date if the new --randomize-release-date
1513 option is enabled. Firefox versions after 4 use a fixed date string
1524 <!-- ~~~~~ New section ~~~~~ -->
1526 <sect2 id="upgradersnote">
1527 <title>Note to Upgraders</title>
1530 A quick list of things to be aware of before upgrading from earlier
1531 versions of <application>Privoxy</application>:
1539 The recommended way to upgrade &my-app; is to backup your old
1540 configuration files, install the new ones, verify that &my-app;
1541 is working correctly and finally merge back your changes using
1542 <application>diff</application> and maybe <application>patch</application>.
1545 There are a number of new features in each &my-app; release and
1546 most of them have to be explicitly enabled in the configuration
1547 files. Old configuration files obviously don't do that and due
1548 to syntax changes using old configuration files with a new
1549 &my-app; isn't always possible anyway.
1554 Note that some installers remove earlier versions completely,
1555 including configuration files, therefore you should really save
1556 any important configuration files!
1561 On the other hand, other installers don't overwrite existing configuration
1562 files, thinking you will want to do that yourself.
1567 <filename>standard.action</filename> has been merged into
1568 the <filename>default.action</filename> file.
1573 In the default configuration only fatal errors are logged now.
1574 You can change that in the <link linkend="DEBUG">debug section</link>
1575 of the configuration file. You may also want to enable more verbose
1576 logging until you verified that the new &my-app; version is working
1583 Three other config file settings are now off by default:
1584 <link linkend="enable-remote-toggle">enable-remote-toggle</link>,
1585 <link linkend="enable-remote-http-toggle">enable-remote-http-toggle</link>,
1586 and <link linkend="enable-edit-actions">enable-edit-actions</link>.
1587 If you use or want these, you will need to explicitly enable them, and
1588 be aware of the security issues involved.
1595 What constitutes a <quote>default</quote> configuration has changed,
1596 and you may want to review which actions are <quote>on</quote> by
1597 default. This is primarily a matter of emphasis, but some features
1598 you may have been used to, may now be <quote>off</quote> by default.
1599 There are also a number of new actions and filters you may want to
1600 consider, most of which are not fully incorporated into the default
1601 settings as yet (see above).
1608 The default actions setting is now <literal>Cautious</literal>. Previous
1609 releases had a default setting of <literal>Medium</literal>. Experienced
1610 users may want to adjust this, as it is fairly conservative by &my-app;
1611 standards and past practices. See <ulink
1612 url="http://config.privoxy.org/edit-actions-list?f=default">
1613 http://config.privoxy.org/edit-actions-list?f=default</ulink>. New users
1614 should try the default settings for a while before turning up the volume.
1620 The default setting has filtering turned <emphasis>off</emphasis>, which
1621 subsequently means that compression is <emphasis>on</emphasis>. Remember
1622 that filtering does not work on compressed pages, so if you use, or want to
1623 use, filtering, you will need to force compression off. Example:
1627 { +<link linkend="filter">filter</link>{google} +<link linkend="prevent-compression">prevent-compression</link> }
1631 Or if you use a number of filters, or filter many sites, you may just want
1632 to turn off compression for all sites in
1633 <filename>default.action</filename> (or
1634 <filename>user.action</filename>).
1641 Also, <link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> is
1642 off by default now. If you've liked this feature in the past, you may want
1643 to turn it back on in <filename>user.action</filename> now.
1650 Some installers may not automatically start
1651 <application>Privoxy</application> after installation.
1662 <!-- ~~~~~ New section ~~~~~ -->
1663 <sect1 id="quickstart"><title>Quickstart to Using Privoxy</title>
1669 Install <application>Privoxy</application>. See the <link
1670 linkend="installation">Installation Section</link> below for platform specific
1677 Advanced users and those who want to offer <application>Privoxy</application>
1678 service to more than just their local machine should check the <link
1679 linkend="config">main config file</link>, especially the <link
1680 linkend="access-control">security-relevant</link> options. These are
1687 Start <application>Privoxy</application>, if the installation program has
1688 not done this already (may vary according to platform). See the section
1689 <link linkend="startup">Starting <application>Privoxy</application></link>.
1695 Set your browser to use <application>Privoxy</application> as HTTP and
1696 HTTPS (SSL) <ulink url="http://en.wikipedia.org/wiki/Proxy_server">proxy</ulink>
1697 by setting the proxy configuration for address of
1698 <literal>127.0.0.1</literal> and port <literal>8118</literal>.
1699 <emphasis>DO NOT</emphasis> activate proxying for <literal>FTP</literal> or
1700 any protocols besides HTTP and HTTPS (SSL) unless you intend to prevent your
1701 browser from using these protocols.
1707 Flush your browser's disk and memory caches, to remove any cached ad images.
1708 If using <application>Privoxy</application> to manage
1709 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>,
1710 you should remove any currently stored cookies too.
1716 A default installation should provide a reasonable starting point for
1717 most. There will undoubtedly be occasions where you will want to adjust the
1718 configuration, but that can be dealt with as the need arises. Little
1719 to no initial configuration is required in most cases, you may want
1721 <ulink url="config.html#ENABLE-EDIT-ACTIONS">web-based action editor</ulink> though.
1722 Be sure to read the warnings first.
1725 See the <link linkend="configuration">Configuration section</link> for more
1726 configuration options, and how to customize your installation.
1727 You might also want to look at the <link
1728 linkend="quickstart-ad-blocking">next section</link> for a quick
1729 introduction to how <application>Privoxy</application> blocks ads and
1736 If you experience ads that slip through, innocent images that are
1737 blocked, or otherwise feel the need to fine-tune
1738 <application>Privoxy's</application> behavior, take a look at the <link
1739 linkend="actions-file">actions files</link>. As a quick start, you might
1740 find the <link linkend="act-examples">richly commented examples</link>
1741 helpful. You can also view and edit the actions files through the <ulink
1742 url="http://config.privoxy.org">web-based user interface</ulink>. The
1743 Appendix <quote><link linkend="actionsanat">Troubleshooting: Anatomy of an
1744 Action</link></quote> has hints on how to understand and debug actions that
1745 <quote>misbehave</quote>.
1750 Did anyone test these lately?
1754 For easy access to &my-app;'s most important controls, drag the provided
1755 <link linkend="bookmarklets">Bookmarklets</link> into your browser's
1763 Please see the section <link linkend="contact">Contacting the
1764 Developers</link> on how to report bugs, problems with websites or to get
1771 Now enjoy surfing with enhanced control, comfort and privacy!
1779 <!-- ~~~~~ New section ~~~~~ -->
1781 <sect2 id="quickstart-ad-blocking">
1782 <title>Quickstart to Ad Blocking</title>
1784 NOTE: This section is deliberately redundant for those that don't
1785 want to read the whole thing (which is getting lengthy).
1788 Ad blocking is but one of <application>Privoxy's</application>
1789 array of features. Many of these features are for the technically minded advanced
1790 user. But, ad and banner blocking is surely common ground for everybody.
1793 This section will provide a quick summary of ad blocking so
1794 you can get up to speed quickly without having to read the more extensive
1795 information provided below, though this is highly recommended.
1798 First a bit of a warning ... blocking ads is much like blocking SPAM: the
1799 more aggressive you are about it, the more likely you are to block
1800 things that were not intended. And the more likely that some things
1801 may not work as intended. So there is a trade off here. If you want
1802 extreme ad free browsing, be prepared to deal with more
1803 <quote>problem</quote> sites, and to spend more time adjusting the
1804 configuration to solve these unintended consequences. In short, there is
1805 not an easy way to eliminate <emphasis>all</emphasis> ads. Either take
1806 the easy way and settle for <emphasis>most</emphasis> ads blocked with the
1807 default configuration, or jump in and tweak it for your personal surfing
1808 habits and preferences.
1811 Secondly, a brief explanation of <application>Privoxy's </application>
1812 <quote>actions</quote>. <quote>Actions</quote> in this context, are
1813 the directives we use to tell <application>Privoxy</application> to perform
1814 some task relating to HTTP transactions (i.e. web browsing). We tell
1815 <application>Privoxy</application> to take some <quote>action</quote>. Each
1816 action has a unique name and function. While there are many potential
1817 <application>actions</application> in <application>Privoxy's</application>
1818 arsenal, only a few are used for ad blocking. <link
1819 linkend="actions">Actions</link>, and <link linkend="actions-file">action
1820 configuration files</link>, are explained in depth below.
1823 Actions are specified in <application>Privoxy's</application> configuration,
1824 followed by one or more URLs to which the action should apply. URLs
1825 can actually be URL type <link linkend="af-patterns">patterns</link> that use
1826 wildcards so they can apply potentially to a range of similar URLs. The
1827 actions, together with the URL patterns are called a section.
1830 When you connect to a website, the full URL will either match one or more
1831 of the sections as defined in <application>Privoxy's</application> configuration,
1832 or not. If so, then <application>Privoxy</application> will perform the
1833 respective actions. If not, then nothing special happens. Furthermore, web
1834 pages may contain embedded, secondary URLs that your web browser will
1835 use to load additional components of the page, as it parses the
1836 original page's HTML content. An ad image for instance, is just an URL
1837 embedded in the page somewhere. The image itself may be on the same server,
1838 or a server somewhere else on the Internet. Complex web pages will have many
1839 such embedded URLs. &my-app; can deal with each URL individually, so, for
1840 instance, the main page text is not touched, but images from such-and-such
1845 The most important actions for basic ad blocking are: <literal><link
1846 linkend="block">block</link></literal>, <literal><link
1847 linkend="handle-as-image">handle-as-image</link></literal>,
1849 linkend="handle-as-empty-document">handle-as-empty-document</link></literal>,and
1850 <literal><link linkend="set-image-blocker">set-image-blocker</link></literal>:
1858 <literal><link linkend="block">block</link></literal> - this is perhaps
1859 the single most used action, and is particularly important for ad blocking.
1860 This action stops any contact between your browser and any URL patterns
1861 that match this action's configuration. It can be used for blocking ads,
1862 but also anything that is determined to be unwanted. By itself, it simply
1863 stops any communication with the remote server and sends
1864 <application>Privoxy</application>'s own built-in BLOCKED page instead to
1865 let you now what has happened (with some exceptions, see below).
1871 <literal><link linkend="handle-as-image">handle-as-image</link></literal> -
1872 tells <application>Privoxy</application> to treat this URL as an image.
1873 <application>Privoxy</application>'s default configuration already does this
1874 for all common image types (e.g. GIF), but there are many situations where this
1875 is not so easy to determine. So we'll force it in these cases. This is particularly
1876 important for ad blocking, since only if we know that it's an image of
1877 some kind, can we replace it with an image of our choosing, instead of the
1878 <application>Privoxy</application> BLOCKED page (which would only result in
1879 a <quote>broken image</quote> icon). There are some limitations to this
1880 though. For instance, you can't just brute-force an image substitution for
1881 an entire HTML page in most situations.
1887 <literal><link linkend="handle-as-empty-document">handle-as-empty-document</link></literal> -
1888 sends an empty document instead of <application>Privoxy's</application>
1889 normal BLOCKED HTML page. This is useful for file types that are neither
1890 HTML nor images, such as blocking JavaScript files.
1897 linkend="set-image-blocker">set-image-blocker</link></literal> - tells
1898 <application>Privoxy</application> what to display in place of an ad image that
1899 has hit a block rule. For this to come into play, the URL must match a
1900 <literal><link linkend="block">block</link></literal> action somewhere in the
1901 configuration, <emphasis>and</emphasis>, it must also match an
1902 <literal><link linkend="handle-as-image">handle-as-image</link></literal> action.
1905 The configuration options on what to display instead of the ad are:
1909 <emphasis>pattern</emphasis> - a checkerboard pattern, so that an ad
1910 replacement is obvious. This is the default.
1915 <emphasis>blank</emphasis> - A very small empty GIF image is displayed.
1916 This is the so-called <quote>invisible</quote> configuration option.
1921 <emphasis>http://<URL></emphasis> - A redirect to any image anywhere
1922 of the user's choosing (advanced usage).
1931 Advanced users will eventually want to explore &my-app;
1932 <literal><link linkend="filter">filters</link></literal> as well. Filters
1933 are very different from <literal><link
1934 linkend="block">blocks</link></literal>.
1935 A <quote>block</quote> blocks a site, page, or unwanted contented. Filters
1936 are a way of filtering or modifying what is actually on the page. An example
1937 filter usage: a text replacement of <quote>no-no</quote> for
1938 <quote>nasty-word</quote>. That is a very simple example. This process can be
1939 used for ad blocking, but it is more in the realm of advanced usage and has
1940 some pitfalls to be wary off.
1944 The quickest way to adjust any of these settings is with your browser through
1945 the special <application>Privoxy</application> editor at <ulink
1946 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
1947 (shortcut: <ulink url="http://p.p/">http://p.p/show-status</ulink>). This
1948 is an internal page, and does not require Internet access.
1952 Note that as of <application>Privoxy</application> 3.0.7 beta the
1953 action editor is disabled by default. Check the
1954 <ulink url="config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions
1955 section in the configuration file</ulink> to learn why and in which
1956 cases it's safe to enable again.
1960 If you decided to enable the action editor, select the appropriate
1961 <quote>actions</quote> file, and click
1962 <quote><guibutton>Edit</guibutton></quote>. It is best to put personal or
1963 local preferences in <filename>user.action</filename> since this is not
1964 meant to be overwritten during upgrades, and will over-ride the settings in
1965 other files. Here you can insert new <quote>actions</quote>, and URLs for ad
1966 blocking or other purposes, and make other adjustments to the configuration.
1967 <application>Privoxy</application> will detect these changes automatically.
1971 A quick and simple step by step example:
1979 Right click on the ad image to be blocked, then select
1980 <quote><guimenuitem>Copy Link Location</guimenuitem></quote> from the
1988 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
1993 Find <filename>user.action</filename> in the top section, and click
1994 on <quote><guibutton>Edit</guibutton></quote>:
1997 <!-- image of editor and actions files selections -->
1999 <figure pgwide="0" float="0"><title>Actions Files in Use</title>
2002 <imagedata fileref="files-in-use.jpg" format="jpg">
2005 <phrase>[ Screenshot of Actions Files in Use ]</phrase>
2014 You should have a section with only
2015 <literal><link linkend="block">block</link></literal> listed under
2016 <quote>Actions:</quote>.
2017 If not, click a <quote><guibutton>Insert new section below</guibutton></quote>
2018 button, and in the new section that just appeared, click the
2019 <guibutton>Edit</guibutton> button right under the word <quote>Actions:</quote>.
2020 This will bring up a list of all actions. Find
2021 <literal><link linkend="block">block</link></literal> near the top, and click
2022 in the <quote>Enabled</quote> column, then <quote><guibutton>Submit</guibutton></quote>
2023 just below the list.
2028 Now, in the <literal><link linkend="block">block</link></literal> actions section,
2029 click the <quote><guibutton>Add</guibutton></quote> button, and paste the URL the
2030 browser got from <quote><guimenuitem>Copy Link Location</guimenuitem></quote>.
2031 Remove the <literal>http://</literal> at the beginning of the URL. Then, click
2032 <quote><guibutton>Submit</guibutton></quote> (or
2033 <quote><guibutton>OK</guibutton></quote> if in a pop-up window).
2038 Now go back to the original page, and press <keycap>SHIFT-Reload</keycap>
2039 (or flush all browser caches). The image should be gone now.
2047 This is a very crude and simple example. There might be good reasons to use a
2048 wildcard pattern match to include potentially similar images from the same
2049 site. For a more extensive explanation of <quote>patterns</quote>, and
2050 the entire actions concept, see <link linkend="actions-file">the Actions
2055 For advanced users who want to hand edit their config files, you might want
2056 to now go to the <link linkend="act-examples">Actions Files Tutorial</link>.
2057 The ideas explained therein also apply to the web-based editor.
2060 There are also various
2061 <link linkend="filter">filters</link> that can be used for ad blocking
2062 (filters are a special subset of actions). These
2063 fall into the <quote>advanced</quote> usage category, and are explained in
2064 depth in later sections.
2071 <!-- ~ End section ~ -->
2074 <!-- ~~~~~ New section ~~~~~ -->
2075 <sect1 id="startup">
2076 <title>Starting Privoxy</title>
2078 Before launching <application>Privoxy</application> for the first time, you
2079 will want to configure your browser(s) to use
2080 <application>Privoxy</application> as a HTTP and HTTPS (SSL)
2081 <ulink url="http://en.wikipedia.org/wiki/Proxy_server">proxy</ulink>. The default is
2082 127.0.0.1 (or localhost) for the proxy address, and port 8118 (earlier versions
2083 used port 8000). This is the one configuration step <emphasis>that must be done
2087 Please note that <application>Privoxy</application> can only proxy HTTP and
2088 HTTPS traffic. It will not work with FTP or other protocols.
2091 <!-- image of Mozilla Proxy configuration -->
2093 <figure pgwide="0" float="0"><title>Proxy Configuration Showing
2094 Mozilla/Netscape HTTP and HTTPS (SSL) Settings</title>
2097 <imagedata fileref="proxy_setup.jpg" format="jpg">
2100 <phrase>[ Screenshot of Mozilla Proxy Configuration ]</phrase>
2108 With <application>Firefox</application>, this is typically set under:
2112 <guibutton>Tools</guibutton> -> <guibutton>Options</guibutton> -> <guibutton>Advanced</guibutton> -> <guibutton>Network</guibutton> -><guibutton>Connection</guibutton> -> <guibutton>Settings</guibutton>
2117 Or optionally on some platforms:
2121 <guibutton>Edit</guibutton> -> <guibutton>Preferences</guibutton> -> <guibutton>General</guibutton> -> <guibutton>Connection Settings</guibutton> -> <guibutton>Manual Proxy Configuration</guibutton>
2127 With <application>Netscape</application> (and
2128 <application>Mozilla</application>), this can be set under:
2133 <!-- Mix ascii and gui art, something for everybody -->
2134 <!-- spacing on this is tricky -->
2135 <guibutton>Edit</guibutton> -> <guibutton>Preferences</guibutton> -> <guibutton>Advanced</guibutton> -> <guibutton>Proxies</guibutton> -> <guibutton>HTTP Proxy</guibutton>
2140 For <application>Internet Explorer v.5-7</application>:
2144 <guibutton>Tools</guibutton> -> <guibutton>Internet Options</guibutton> -> <guibutton>Connections</guibutton> -> <guibutton>LAN Settings</guibutton>
2148 Then, check <quote>Use Proxy</quote> and fill in the appropriate info
2149 (Address: 127.0.0.1, Port: 8118). Include HTTPS (SSL), if you want HTTPS
2150 proxy support too (sometimes labeled <quote>Secure</quote>). Make sure any
2151 checkboxes like <quote>Use the same proxy server for all protocols</quote> is
2152 <emphasis>UNCHECKED</emphasis>. You want only HTTP and HTTPS (SSL)!
2155 <!-- image of IE Proxy configuration -->
2157 <figure pgwide="0" float="0"><title>Proxy Configuration Showing
2158 Internet Explorer HTTP and HTTPS (Secure) Settings</title>
2161 <imagedata fileref="proxy2.jpg" format="jpg">
2164 <phrase>[ Screenshot of IE Proxy Configuration ]</phrase>
2172 After doing this, flush your browser's disk and memory caches to force a
2173 re-reading of all pages and to get rid of any ads that may be cached. Remove
2174 any <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>,
2175 if you want <application>Privoxy</application> to manage that. You are now
2176 ready to start enjoying the benefits of using
2177 <application>Privoxy</application>!
2181 <application>Privoxy</application> itself is typically started by specifying the
2182 main configuration file to be used on the command line. If no configuration
2183 file is specified on the command line, <application>Privoxy</application>
2184 will look for a file named <filename>config</filename> in the current
2185 directory. Except on Win32 where it will try <filename>config.txt</filename>.
2188 <sect2 id="start-redhat">
2189 <title>Red Hat and Fedora</title>
2191 A default Red Hat installation may not start &my-app; upon boot. It will use
2192 the file <filename>/etc/privoxy/config</filename> as its main configuration
2197 # /etc/rc.d/init.d/privoxy start
2205 # service privoxy start
2210 <sect2 id="start-debian">
2211 <title>Debian</title>
2213 We use a script. Note that Debian typically starts &my-app; upon booting per
2214 default. It will use the file
2215 <filename>/etc/privoxy/config</filename> as its main configuration
2220 # /etc/init.d/privoxy start
2225 <sect2 id="start-windows">
2226 <title>Windows</title>
2228 Click on the &my-app; Icon to start <application>Privoxy</application>. If no configuration file is
2229 specified on the command line, <application>Privoxy</application> will look
2230 for a file named <filename>config.txt</filename>. Note that Windows will
2231 automatically start &my-app; when the system starts if you chose that option
2235 <application>Privoxy</application> can run with full Windows service functionality.
2236 On Windows only, the &my-app; program has two new command line arguments
2237 to install and uninstall &my-app; as a service. See the
2238 <link linkend="installation-pack-win">Windows Installation
2239 instructions</link> for details.
2243 <sect2 id="start-unices">
2244 <title>Solaris, NetBSD, FreeBSD, HP-UX and others</title>
2246 Example Unix startup command:
2250 # /usr/sbin/privoxy /etc/privoxy/config
2255 <sect2 id="start-os2">
2258 During installation, <application>Privoxy</application> is configured to
2259 start automatically when the system restarts. You can start it manually by
2260 double-clicking on the <application>Privoxy</application> icon in the
2261 <application>Privoxy</application> folder.
2265 <sect2 id="start-macosx">
2266 <title>Mac OS X</title>
2268 After downloading the privoxy software, unzip the downloaded file by
2269 double-clicking on the zip file icon. Then, double-click on the
2270 installer package icon and follow the installation process.
2273 The privoxy service will automatically start after a successful
2274 installation. In addition, the privoxy service will automatically
2275 start every time your computer starts up.
2278 To prevent the privoxy service from automatically starting when your
2279 computer starts up, remove or rename the folder named
2280 /Library/StartupItems/Privoxy.
2283 A simple application named Privoxy Utility has been created which
2284 enables administrators to easily start and stop the privoxy service.
2287 In addition, the Privoxy Utility presents a simple way for
2288 administrators to edit the various privoxy config files. A method
2289 to uninstall the software is also available.
2292 An administrator username and password must be supplied in order for
2293 the Privoxy Utility to perform any of the tasks.
2298 <sect2 id="start-amigaos">
2299 <title>AmigaOS</title>
2301 Start <application>Privoxy</application> (with RUN <>NIL:) in your
2302 <filename>startnet</filename> script (AmiTCP), in
2303 <filename>s:user-startup</filename> (RoadShow), as startup program in your
2304 startup script (Genesis), or as startup action (Miami and MiamiDx).
2305 <application>Privoxy</application> will automatically quit when you quit your
2306 TCP/IP stack (just ignore the harmless warning your TCP/IP stack may display that
2307 <application>Privoxy</application> is still running).
2311 <sect2 id="start-gentoo">
2312 <title>Gentoo</title>
2314 A script is again used. It will use the file <filename>/etc/privoxy/config
2315 </filename> as its main configuration file.
2319 /etc/init.d/privoxy start
2323 Note that <application>Privoxy</application> is not automatically started at
2324 boot time by default. You can change this with the <literal>rc-update</literal>
2329 rc-update add privoxy default
2337 See the section <link linkend="cmdoptions">Command line options</link> for
2341 must find a better place for this paragraph
2344 The included default configuration files should give a reasonable starting
2345 point. Most of the per site configuration is done in the
2346 <ulink url="actions-file.html"><quote>actions</quote></ulink> files. These are
2347 where various cookie actions are defined, ad and banner blocking, and other
2348 aspects of <application>Privoxy</application> configuration. There are several
2349 such files included, with varying levels of aggressiveness.
2353 You will probably want to keep an eye out for sites for which you may prefer
2354 persistent cookies, and add these to your actions configuration as needed. By
2355 default, most of these will be accepted only during the current browser
2356 session (aka <quote>session cookies</quote>), unless you add them to the
2357 configuration. If you want the browser to handle this instead, you will need
2358 to edit <filename>user.action</filename> (or through the web based interface)
2359 and disable this feature. If you use more than one browser, it would make
2360 more sense to let <application>Privoxy</application> handle this. In which
2361 case, the browser(s) should be set to accept all cookies.
2365 Another feature where you will probably want to define exceptions for trusted
2366 sites is the popup-killing (through <ulink
2367 url="actions-file.html#FILTER-POPUPS"><quote>+filter{popups}</quote></ulink>),
2368 because your favorite shopping, banking, or leisure site may need
2369 popups (explained below).
2373 <application>Privoxy</application> does not support all of the optional HTTP/1.1
2374 features yet. In the unlikely event that you experience inexplicable problems
2375 with browsers that use HTTP/1.1 per default
2376 (like <application>Mozilla</application> or recent versions of I.E.), you might
2377 try to force HTTP/1.0 compatibility. For Mozilla, look under <literal>Edit ->
2378 Preferences -> Debug -> Networking</literal>.
2379 Alternatively, set the <quote>+downgrade-http-version</quote> config option in
2380 <filename>default.action</filename> which will downgrade your browser's HTTP
2381 requests from HTTP/1.1 to HTTP/1.0 before processing them.
2385 After running <application>Privoxy</application> for a while, you can
2386 start to fine tune the configuration to suit your personal, or site,
2387 preferences and requirements. There are many, many aspects that can
2388 be customized. <quote>Actions</quote>
2389 can be adjusted by pointing your browser to
2390 <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
2391 (shortcut: <ulink url="http://p.p/">http://p.p/</ulink>),
2392 and then follow the link to <quote>View & Change the Current Configuration</quote>.
2393 (This is an internal page and does not require Internet access.)
2397 In fact, various aspects of <application>Privoxy</application>
2398 configuration can be viewed from this page, including
2399 current configuration parameters, source code version numbers,
2400 the browser's request headers, and <quote>actions</quote> that apply
2401 to a given URL. In addition to the actions file
2402 editor mentioned above, <application>Privoxy</application> can also
2403 be turned <quote>on</quote> and <quote>off</quote> (toggled) from this page.
2407 If you encounter problems, try loading the page without
2408 <application>Privoxy</application>. If that helps, enter the URL where
2409 you have the problems into <ulink url="http://p.p/show-url-info">the browser
2410 based rule tracing utility</ulink>. See which rules apply and why, and
2411 then try turning them off for that site one after the other, until the problem
2412 is gone. When you have found the culprit, you might want to turn the rest on
2417 If the above paragraph sounds gibberish to you, you might want to <link
2418 linkend="actions-file">read more about the actions concept</link>
2419 or even dive deep into the <link linkend="actionsanat">Appendix
2424 If you can't get rid of the problem at all, think you've found a bug in
2425 Privoxy, want to propose a new feature or smarter rules, please see the
2426 section <link linkend="contact"><quote>Contacting the
2427 Developers</quote></link> below.
2432 <!-- ~~~~~ New section ~~~~~ -->
2433 <sect2 id="cmdoptions">
2434 <title>Command Line Options</title>
2436 <application>Privoxy</application> may be invoked with the following
2437 command-line options:
2445 <emphasis>--config-test</emphasis>
2448 Exit after loading the configuration files before binding to
2449 the listen address. The exit code signals whether or not the
2450 configuration files have been successfully loaded.
2453 If the exit code is 1, at least one of the configuration files
2454 is invalid, if it is 0, all the configuration files have been
2455 successfully loaded (but may still contain errors that can
2456 currently only be detected at run time).
2459 This option doesn't affect the log setting, combination with
2460 <emphasis>--no-daemon</emphasis> is recommended if a configured
2461 log file shouldn't be used.
2466 <emphasis>--version</emphasis>
2469 Print version info and exit. Unix only.
2474 <emphasis>--help</emphasis>
2477 Print short usage info and exit. Unix only.
2482 <emphasis>--no-daemon</emphasis>
2485 Don't become a daemon, i.e. don't fork and become process group
2486 leader, and don't detach from controlling tty. Unix only.
2491 <emphasis>--pidfile FILE</emphasis>
2494 On startup, write the process ID to <emphasis>FILE</emphasis>. Delete the
2495 <emphasis>FILE</emphasis> on exit. Failure to create or delete the
2496 <emphasis>FILE</emphasis> is non-fatal. If no <emphasis>FILE</emphasis>
2497 option is given, no PID file will be used. Unix only.
2502 <emphasis>--user USER[.GROUP]</emphasis>
2505 After (optionally) writing the PID file, assume the user ID of
2506 <emphasis>USER</emphasis>, and if included the GID of GROUP. Exit if the
2507 privileges are not sufficient to do so. Unix only.
2512 <emphasis>--chroot</emphasis>
2515 Before changing to the user ID given in the <emphasis>--user</emphasis> option,
2516 chroot to that user's home directory, i.e. make the kernel pretend to the &my-app;
2517 process that the directory tree starts there. If set up carefully, this can limit
2518 the impact of possible vulnerabilities in &my-app; to the files contained in that hierarchy.
2524 <emphasis>--pre-chroot-nslookup hostname</emphasis>
2527 Specifies a hostname to look up before doing a chroot. On some systems, initializing the
2528 resolver library involves reading config files from /etc and/or loading additional shared
2529 libraries from /lib. On these systems, doing a hostname lookup before the chroot reduces
2530 the number of files that must be copied into the chroot tree.
2533 For fastest startup speed, a good value is a hostname that is not in /etc/hosts but that
2534 your local name server (listed in /etc/resolv.conf) can resolve without recursion
2535 (that is, without having to ask any other name servers). The hostname need not exist,
2536 but if it doesn't, an error message (which can be ignored) will be output.
2542 <emphasis>configfile</emphasis>
2545 If no <emphasis>configfile</emphasis> is included on the command line,
2546 <application>Privoxy</application> will look for a file named
2547 <quote>config</quote> in the current directory (except on Win32
2548 where it will look for <quote>config.txt</quote> instead). Specify
2549 full path to avoid confusion. If no config file is found,
2550 <application>Privoxy</application> will fail to start.
2558 On <application>MS Windows</application> only there are two additional
2559 command-line options to allow <application>Privoxy</application> to install and
2560 run as a <emphasis>service</emphasis>. See the
2561 <link linkend="installation-pack-win">Window Installation section</link>
2569 <!-- ~ End section ~ -->
2572 <!-- ~~~~~ New section ~~~~~ -->
2573 <sect1 id="configuration"><title>Privoxy Configuration</title>
2575 All <application>Privoxy</application> configuration is stored
2576 in text files. These files can be edited with a text editor.
2577 Many important aspects of <application>Privoxy</application> can
2578 also be controlled easily with a web browser.
2582 <!-- ~~~~~ New section ~~~~~ -->
2585 <title>Controlling Privoxy with Your Web Browser</title>
2587 <application>Privoxy</application>'s user interface can be reached through the special
2588 URL <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
2589 (shortcut: <ulink url="http://p.p/">http://p.p/</ulink>),
2590 which is a built-in page and works without Internet access.
2591 You will see the following section:
2595 <!-- Needs to be put in a table and colorized -->
2598 <bridgehead renderas="sect2"> Privoxy Menu</bridgehead>
2602 ▪ <ulink url="http://config.privoxy.org/show-status">View & change the current configuration</ulink>
2605 ▪ <ulink url="http://config.privoxy.org/show-version">View the source code version numbers</ulink>
2608 ▪ <ulink url="http://config.privoxy.org/show-request">View the request headers.</ulink>
2611 ▪ <ulink url="http://config.privoxy.org/show-url-info">Look up which actions apply to a URL and why</ulink>
2614 ▪ <ulink url="http://config.privoxy.org/toggle">Toggle Privoxy on or off</ulink>
2617 ▪ <ulink
2618 url="http://www.privoxy.org/&p-version;/user-manual/">Documentation</ulink>
2626 This should be self-explanatory. Note the first item leads to an editor for the
2627 <link linkend="actions-file">actions files</link>, which is where the ad, banner,
2628 cookie, and URL blocking magic is configured as well as other advanced features of
2629 <application>Privoxy</application>. This is an easy way to adjust various
2630 aspects of <application>Privoxy</application> configuration. The actions
2631 file, and other configuration files, are explained in detail below.
2635 <quote>Toggle Privoxy On or Off</quote> is handy for sites that might
2636 have problems with your current actions and filters. You can in fact use
2637 it as a test to see whether it is <application>Privoxy</application>
2638 causing the problem or not. <application>Privoxy</application> continues
2639 to run as a proxy in this case, but all manipulation is disabled, i.e.
2640 <application>Privoxy</application> acts like a normal forwarding proxy. There
2641 is even a toggle <link linkend="bookmarklets">Bookmarklet</link> offered, so
2642 that you can toggle <application>Privoxy</application> with one click from
2647 Note that several of the features described above are disabled by default
2648 in <application>Privoxy</application> 3.0.7 beta and later.
2650 <ulink url="config.html">configuration file</ulink> to learn why
2651 and in which cases it's safe to enable them again.
2656 <!-- ~ End section ~ -->
2661 <!-- ~~~~~ New section ~~~~~ -->
2663 <sect2 id="confoverview">
2664 <title>Configuration Files Overview</title>
2666 For Unix, *BSD and Linux, all configuration files are located in
2667 <filename>/etc/privoxy/</filename> by default. For MS Windows, OS/2, and
2668 AmigaOS these are all in the same directory as the
2669 <application>Privoxy</application> executable. <![%p-not-stable;[ The name
2670 and number of configuration files has changed from previous versions, and is
2671 subject to change as development progresses.]]>
2675 The installed defaults provide a reasonable starting point, though
2676 some settings may be aggressive by some standards. For the time being, the
2677 principle configuration files are:
2685 The <link linkend="config">main configuration file</link> is named <filename>config</filename>
2686 on Linux, Unix, BSD, OS/2, and AmigaOS and <filename>config.txt</filename>
2687 on Windows. This is a required file.
2693 <filename>match-all.action</filename> is used to define which <quote>actions</quote>
2694 relating to banner-blocking, images, pop-ups, content modification, cookie handling
2695 etc should be applied by default. It should be the first actions file loaded.
2698 <filename>default.action</filename> defines many exceptions (both positive and negative)
2699 from the default set of actions that's configured in <filename>match-all.action</filename>.
2700 It should be the second actions file loaded and shouldn't be edited by the user.
2703 Multiple actions files may be defined in <filename>config</filename>. These
2704 are processed in the order they are defined. Local customizations and locally
2705 preferred exceptions to the default policies as defined in
2706 <filename>match-all.action</filename> (which you will most probably want
2707 to define sooner or later) are best applied in <filename>user.action</filename>,
2708 where you can preserve them across upgrades. The file isn't installed by all
2709 installers, but you can easily create it yourself with a text editor.
2712 There is also a web based editor that can be accessed from
2714 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
2716 url="http://p.p/show-status">http://p.p/show-status</ulink>) for the
2717 various actions files.
2723 <quote>Filter files</quote> (the <link linkend="filter-file">filter
2724 file</link>) can be used to re-write the raw page content, including
2725 viewable text as well as embedded HTML and JavaScript, and whatever else
2726 lurks on any given web page. The filtering jobs are only pre-defined here;
2727 whether to apply them or not is up to the actions files.
2728 <filename>default.filter</filename> includes various filters made
2729 available for use by the developers. Some are much more intrusive than
2730 others, and all should be used with caution. You may define additional
2731 filter files in <filename>config</filename> as you can with
2732 actions files. We suggest <filename>user.filter</filename> for any
2733 locally defined filters or customizations.
2741 The syntax of the configuration and filter files may change between different
2742 Privoxy versions, unfortunately some enhancements cost backwards compatibility.
2743 <!-- Add link to documentation-->
2747 All files use the <quote><literal>#</literal></quote> character to denote a
2748 comment (the rest of the line will be ignored) and understand line continuation
2749 through placing a backslash ("<literal>\</literal>") as the very last character
2750 in a line. If the <literal>#</literal> is preceded by a backslash, it looses
2751 its special function. Placing a <literal>#</literal> in front of an otherwise
2752 valid configuration line to prevent it from being interpreted is called "commenting
2753 out" that line. Blank lines are ignored.
2757 The actions files and filter files
2758 can use Perl style <link linkend="regex">regular expressions</link> for
2759 maximum flexibility.
2763 After making any changes, there is no need to restart
2764 <application>Privoxy</application> in order for the changes to take
2765 effect. <application>Privoxy</application> detects such changes
2766 automatically. Note, however, that it may take one or two additional
2767 requests for the change to take effect. When changing the listening address
2768 of <application>Privoxy</application>, these <quote>wake up</quote> requests
2769 must obviously be sent to the <emphasis>old</emphasis> listening address.
2774 While under development, the configuration content is subject to change.
2775 The below documentation may not be accurate by the time you read this.
2776 Also, what constitutes a <quote>default</quote> setting, may change, so
2777 please check all your configuration files on important issues.
2783 <!-- ~ End section ~ -->
2786 <!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
2788 <!-- **************************************************** -->
2789 <!-- Include config.sgml here -->
2790 <!-- This is where the entire config file is detailed. -->
2792 <!-- end include -->
2795 <!-- ~ End section ~ -->
2799 <!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
2801 <sect1 id="actions-file"><title>Actions Files</title>
2805 XXX: similar descriptions are in the Configuration Files sections.
2806 We should only describe them at one place.
2809 The actions files are used to define what <emphasis>actions</emphasis>
2810 <application>Privoxy</application> takes for which URLs, and thus determines
2811 how ad images, cookies and various other aspects of HTTP content and
2812 transactions are handled, and on which sites (or even parts thereof).
2813 There are a number of such actions, with a wide range of functionality.
2814 Each action does something a little different.
2815 These actions give us a veritable arsenal of tools with which to exert
2816 our control, preferences and independence. Actions can be combined so that
2817 their effects are aggregated when applied against a given set of URLs.
2821 are three action files included with <application>Privoxy</application> with
2828 <filename>match-all.action</filename> - is used to define which
2829 <quote>actions</quote> relating to banner-blocking, images, pop-ups,
2830 content modification, cookie handling etc should be applied by default.
2831 It should be the first actions file loaded
2836 <filename>default.action</filename> - defines many exceptions (both
2837 positive and negative) from the default set of actions that's configured
2838 in <filename>match-all.action</filename>. It is a set of rules that should
2839 work reasonably well as-is for most users. This file is only supposed to
2840 be edited by the developers. It should be the second actions file loaded.
2845 <filename>user.action</filename> - is intended to be for local site
2846 preferences and exceptions. As an example, if your ISP or your bank
2847 has specific requirements, and need special handling, this kind of
2848 thing should go here. This file will not be upgraded.
2853 <guibutton>Edit</guibutton> <guibutton>Set to Cautious</guibutton> <guibutton>Set to Medium</guibutton> <guibutton>Set to Advanced</guibutton>
2856 These have increasing levels of aggressiveness <emphasis>and have no
2857 influence on your browsing unless you select them explicitly in the
2858 editor</emphasis>. A default installation should be pre-set to
2859 <literal>Cautious</literal>. New users should try this for a while before
2860 adjusting the settings to more aggressive levels. The more aggressive
2861 the settings, then the more likelihood there is of problems such as sites
2862 not working as they should.
2865 The <guibutton>Edit</guibutton> button allows you to turn each
2866 action on/off individually for fine-tuning. The <guibutton>Cautious</guibutton>
2867 button changes the actions list to low/safe settings which will activate
2868 ad blocking and a minimal set of &my-app;'s features, and subsequently
2869 there will be less of a chance for accidental problems. The
2870 <guibutton>Medium</guibutton> button sets the list to a medium level of
2871 other features and a low level set of privacy features. The
2872 <guibutton>Advanced</guibutton> button sets the list to a high level of
2873 ad blocking and medium level of privacy. See the chart below. The latter
2874 three buttons over-ride any changes via with the
2875 <guibutton>Edit</guibutton> button. More fine-tuning can be done in the
2876 lower sections of this internal page.
2879 While the actions file editor allows to enable these settings in all
2880 actions files, they are only supposed to be enabled in the first one
2881 to make sure you don't unintentionally overrule earlier rules.
2884 The default profiles, and their associated actions, as pre-defined in
2885 <filename>default.action</filename> are:
2888 <table frame=all><title>Default Configurations</title>
2889 <tgroup cols=4 align=left colsep=1 rowsep=1>
2890 <colspec colname=c1>
2891 <colspec colname=c2>
2892 <colspec colname=c3>
2893 <colspec colname=c4>
2896 <entry>Feature</entry>
2897 <entry>Cautious</entry>
2898 <entry>Medium</entry>
2899 <entry>Advanced</entry>
2904 <!-- <entry>f1</entry> -->
2905 <!-- <entry>f2</entry> -->
2906 <!-- <entry>f3</entry> -->
2907 <!-- <entry>f4</entry> -->
2913 <entry>Ad-blocking Aggressiveness</entry>
2914 <entry>medium</entry>
2920 <entry>Ad-filtering by size</entry>
2927 <entry>Ad-filtering by link</entry>
2933 <entry>Pop-up killing</entry>
2934 <entry>blocks only</entry>
2935 <entry>blocks only</entry>
2936 <entry>blocks only</entry>
2940 <entry>Privacy Features</entry>
2942 <entry>medium</entry>
2943 <entry>medium/high</entry>
2947 <entry>Cookie handling</entry>
2949 <entry>session-only</entry>
2954 <entry>Referer forging</entry>
2961 <entry>GIF de-animation</entry>
2968 <entry>Fast redirects</entry>
2975 <entry>HTML taming</entry>
2982 <entry>JavaScript taming</entry>
2989 <entry>Web-bug killing</entry>
2996 <entry>Image tag reordering</entry>
3012 The list of actions files to be used are defined in the main configuration
3013 file, and are processed in the order they are defined (e.g.
3014 <filename>default.action</filename> is typically processed before
3015 <filename>user.action</filename>). The content of these can all be viewed and
3017 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>.
3018 The over-riding principle when applying actions, is that the last action that
3019 matches a given URL wins. The broadest, most general rules go first
3020 (defined in <filename>default.action</filename>),
3021 followed by any exceptions (typically also in
3022 <filename>default.action</filename>), which are then followed lastly by any
3023 local preferences (typically in <emphasis>user</emphasis><filename>.action</filename>).
3024 Generally, <filename>user.action</filename> has the last word.
3028 An actions file typically has multiple sections. If you want to use
3029 <quote>aliases</quote> in an actions file, you have to place the (optional)
3030 <link linkend="aliases">alias section</link> at the top of that file.
3031 Then comes the default set of rules which will apply universally to all
3032 sites and pages (be <emphasis>very careful</emphasis> with using such a
3033 universal set in <filename>user.action</filename> or any other actions file after
3034 <filename>default.action</filename>, because it will override the result
3035 from consulting any previous file). And then below that,
3036 exceptions to the defined universal policies. You can regard
3037 <filename>user.action</filename> as an appendix to <filename>default.action</filename>,
3038 with the advantage that it is a separate file, which makes preserving your
3039 personal settings across <application>Privoxy</application> upgrades easier.
3043 Actions can be used to block anything you want, including ads, banners, or
3044 just some obnoxious URL whose content you would rather not see. Cookies can be accepted
3045 or rejected, or accepted only during the current browser session (i.e. not
3046 written to disk), content can be modified, some JavaScripts tamed, user-tracking
3047 fooled, and much more. See below for a <link linkend="actions">complete list
3051 <!-- ~~~~~ New section ~~~~~ -->
3053 <title>Finding the Right Mix</title>
3055 Note that some <link linkend="actions">actions</link>, like cookie suppression
3056 or script disabling, may render some sites unusable that rely on these
3057 techniques to work properly. Finding the right mix of actions is not always easy and
3058 certainly a matter of personal taste. And, things can always change, requiring
3059 refinements in the configuration. In general, it can be said that the more
3060 <quote>aggressive</quote> your default settings (in the top section of the
3061 actions file) are, the more exceptions for <quote>trusted</quote> sites you
3062 will have to make later. If, for example, you want to crunch all cookies per
3063 default, you'll have to make exceptions from that rule for sites that you
3064 regularly use and that require cookies for actually useful purposes, like maybe
3065 your bank, favorite shop, or newspaper.
3069 We have tried to provide you with reasonable rules to start from in the
3070 distribution actions files. But there is no general rule of thumb on these
3071 things. There just are too many variables, and sites are constantly changing.
3072 Sooner or later you will want to change the rules (and read this chapter again :).
3076 <!-- ~~~~~ New section ~~~~~ -->
3078 <title>How to Edit</title>
3080 The easiest way to edit the actions files is with a browser by
3081 using our browser-based editor, which can be reached from <ulink
3082 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>.
3083 Note: the config file option <link
3084 linkend="enable-edit-actions">enable-edit-actions</link> must be enabled for
3085 this to work. The editor allows both fine-grained control over every single
3086 feature on a per-URL basis, and easy choosing from wholesale sets of defaults
3087 like <quote>Cautious</quote>, <quote>Medium</quote> or
3088 <quote>Advanced</quote>. Warning: the <quote>Advanced</quote> setting is more
3089 aggressive, and will be more likely to cause problems for some sites.
3090 Experienced users only!
3094 If you prefer plain text editing to GUIs, you can of course also directly edit the
3095 the actions files with your favorite text editor. Look at
3096 <filename>default.action</filename> which is richly commented with many
3102 <sect2 id="actions-apply">
3103 <title>How Actions are Applied to Requests</title>
3105 Actions files are divided into sections. There are special sections,
3106 like the <quote><link linkend="aliases">alias</link></quote> sections which will
3107 be discussed later. For now let's concentrate on regular sections: They have a
3108 heading line (often split up to multiple lines for readability) which consist
3109 of a list of actions, separated by whitespace and enclosed in curly braces.
3110 Below that, there is a list of URL and tag patterns, each on a separate line.
3114 To determine which actions apply to a request, the URL of the request is
3115 compared to all URL patterns in each <quote>action file</quote>.
3116 Every time it matches, the list of applicable actions for the request is
3117 incrementally updated, using the heading of the section in which the
3118 pattern is located. The same is done again for tags and tag patterns later on.
3122 If multiple applying sections set the same action differently,
3123 the last match wins. If not, the effects are aggregated.
3124 E.g. a URL might match a regular section with a heading line of <literal>{
3125 +<link linkend="handle-as-image">handle-as-image</link> }</literal>,
3126 then later another one with just <literal>{
3127 +<link linkend="block">block</link> }</literal>, resulting
3128 in <emphasis>both</emphasis> actions to apply. And there may well be
3129 cases where you will want to combine actions together. Such a section then
3135 { +<literal>handle-as-image</literal> +<literal>block{Banner ads.}</literal> }
3136 # Block these as if they were images. Send no block page.
3138 media.example.com/.*banners
3139 .example.com/images/ads/</screen>
3143 You can trace this process for URL patterns and any given URL by visiting <ulink
3144 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>.
3148 Examples and more detail on this is provided in the Appendix, <link linkend="ACTIONSANAT">
3149 Troubleshooting: Anatomy of an Action</link> section.
3153 <!-- ~~~~~ New section ~~~~~ -->
3154 <sect2 id="af-patterns">
3155 <title>Patterns</title>
3157 As mentioned, <application>Privoxy</application> uses <quote>patterns</quote>
3158 to determine what <emphasis>actions</emphasis> might apply to which sites and
3159 pages your browser attempts to access. These <quote>patterns</quote> use wild
3160 card type <emphasis>pattern</emphasis> matching to achieve a high degree of
3161 flexibility. This allows one expression to be expanded and potentially match
3162 against many similar patterns.
3166 Generally, an URL pattern has the form
3167 <literal><domain><port>/<path></literal>, where the
3168 <literal><domain></literal>, the <literal><port></literal>
3169 and the <literal><path></literal> are optional. (This is why the special
3170 <literal>/</literal> pattern matches all URLs). Note that the protocol
3171 portion of the URL pattern (e.g. <literal>http://</literal>) should
3172 <emphasis>not</emphasis> be included in the pattern. This is assumed already!
3175 The pattern matching syntax is different for the domain and path parts of
3176 the URL. The domain part uses a simple globbing type matching technique,
3177 while the path part uses more flexible
3178 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
3179 Expressions</quote></ulink> (POSIX 1003.2).
3182 The port part of a pattern is a decimal port number preceded by a colon
3183 (<literal>:</literal>). If the domain part contains a numerical IPv6 address,
3184 it has to be put into angle brackets
3185 (<literal><</literal>, <literal>></literal>).
3190 <term><literal>www.example.com/</literal></term>
3193 is a domain-only pattern and will match any request to <literal>www.example.com</literal>,
3194 regardless of which document on that server is requested. So ALL pages in
3195 this domain would be covered by the scope of this action. Note that a
3196 simple <literal>example.com</literal> is different and would NOT match.
3201 <term><literal>www.example.com</literal></term>
3204 means exactly the same. For domain-only patterns, the trailing <literal>/</literal> may
3210 <term><literal>www.example.com/index.html</literal></term>
3213 matches all the documents on <literal>www.example.com</literal>
3214 whose name starts with <literal>/index.html</literal>.
3219 <term><literal>www.example.com/index.html$</literal></term>
3222 matches only the single document <literal>/index.html</literal>
3223 on <literal>www.example.com</literal>.
3228 <term><literal>/index.html$</literal></term>
3231 matches the document <literal>/index.html</literal>, regardless of the domain,
3232 i.e. on <emphasis>any</emphasis> web server anywhere.
3237 <term><literal>/</literal></term>
3240 Matches any URL because there's no requirement for either the
3241 domain or the path to match anything.
3246 <term><literal>:8000/</literal></term>
3249 Matches any URL pointing to TCP port 8000.
3254 <term><literal><2001:db8::1>/</literal></term>
3257 Matches any URL with the host address <literal>2001:db8::1</literal>.
3258 (Note that the real URL uses plain brackets, not angle brackets.)
3263 <term><literal>index.html</literal></term>
3266 matches nothing, since it would be interpreted as a domain name and
3267 there is no top-level domain called <literal>.html</literal>. So its
3275 <!-- ~~~~~ New section ~~~~~ -->
3276 <sect3><title>The Domain Pattern</title>
3279 The matching of the domain part offers some flexible options: if the
3280 domain starts or ends with a dot, it becomes unanchored at that end.
3286 <term><literal>.example.com</literal></term>
3289 matches any domain with first-level domain <literal>com</literal>
3290 and second-level domain <literal>example</literal>.
3291 For example <literal>www.example.com</literal>,
3292 <literal>example.com</literal> and <literal>foo.bar.baz.example.com</literal>.
3293 Note that it wouldn't match if the second-level domain was <literal>another-example</literal>.
3298 <term><literal>www.</literal></term>
3301 matches any domain that <emphasis>STARTS</emphasis> with
3302 <literal>www.</literal> (It also matches the domain
3303 <literal>www</literal> but most of the time that doesn't matter.)
3308 <term><literal>.example.</literal></term>
3311 matches any domain that <emphasis>CONTAINS</emphasis> <literal>.example.</literal>.
3312 And, by the way, also included would be any files or documents that exist
3313 within that domain since no path limitations are specified. (Correctly
3314 speaking: It matches any FQDN that contains <literal>example</literal> as
3315 a domain.) This might be <literal>www.example.com</literal>,
3316 <literal>news.example.de</literal>, or
3317 <literal>www.example.net/cgi/testing.pl</literal> for instance. All these
3325 Additionally, there are wild-cards that you can use in the domain names
3326 themselves. These work similarly to shell globbing type wild-cards:
3327 <quote>*</quote> represents zero or more arbitrary characters (this is
3329 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
3330 Expression</quote></ulink> based syntax of <quote>.*</quote>),
3331 <quote>?</quote> represents any single character (this is equivalent to the
3332 regular expression syntax of a simple <quote>.</quote>), and you can define
3333 <quote>character classes</quote> in square brackets which is similar to
3334 the same regular expression technique. All of this can be freely mixed:
3339 <term><literal>ad*.example.com</literal></term>
3342 matches <quote>adserver.example.com</quote>,
3343 <quote>ads.example.com</quote>, etc but not <quote>sfads.example.com</quote>
3348 <term><literal>*ad*.example.com</literal></term>
3351 matches all of the above, and then some.
3356 <term><literal>.?pix.com</literal></term>
3359 matches <literal>www.ipix.com</literal>,
3360 <literal>pictures.epix.com</literal>, <literal>a.b.c.d.e.upix.com</literal> etc.
3365 <term><literal>www[1-9a-ez].example.c*</literal></term>
3368 matches <literal>www1.example.com</literal>,
3369 <literal>www4.example.cc</literal>, <literal>wwwd.example.cy</literal>,
3370 <literal>wwwz.example.com</literal> etc., but <emphasis>not</emphasis>
3371 <literal>wwww.example.com</literal>.
3378 While flexible, this is not the sophistication of full regular expression based syntax.
3383 <!-- ~ End section ~ -->
3386 <!-- ~~~~~ New section ~~~~~ -->
3387 <sect3><title>The Path Pattern</title>
3390 <application>Privoxy</application> uses <quote>modern</quote> POSIX 1003.2
3391 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
3392 Expressions</quote></ulink> for matching the path portion (after the slash),
3393 and is thus more flexible.
3397 There is an <link linkend="regex">Appendix</link> with a brief quick-start into regular
3398 expressions, you also might want to have a look at your operating system's documentation
3399 on regular expressions (try <literal>man re_format</literal>).
3403 Note that the path pattern is automatically left-anchored at the <quote>/</quote>,
3404 i.e. it matches as if it would start with a <quote>^</quote> (regular expression speak
3405 for the beginning of a line).
3409 Please also note that matching in the path is <emphasis>CASE INSENSITIVE</emphasis>
3410 by default, but you can switch to case sensitive at any point in the pattern by using the
3411 <quote>(?-i)</quote> switch: <literal>www.example.com/(?-i)PaTtErN.*</literal> will match
3412 only documents whose path starts with <literal>PaTtErN</literal> in
3413 <emphasis>exactly</emphasis> this capitalization.
3418 <term><literal>.example.com/.*</literal></term>
3421 Is equivalent to just <quote>.example.com</quote>, since any documents
3422 within that domain are matched with or without the <quote>.*</quote>
3423 regular expression. This is redundant
3428 <term><literal>.example.com/.*/index.html$</literal></term>
3431 Will match any page in the domain of <quote>example.com</quote> that is
3432 named <quote>index.html</quote>, and that is part of some path. For
3433 example, it matches <quote>www.example.com/testing/index.html</quote> but
3434 NOT <quote>www.example.com/index.html</quote> because the regular
3435 expression called for at least two <quote>/'s</quote>, thus the path
3436 requirement. It also would match
3437 <quote>www.example.com/testing/index_html</quote>, because of the
3438 special meta-character <quote>.</quote>.
3443 <term><literal>.example.com/(.*/)?index\.html$</literal></term>
3446 This regular expression is conditional so it will match any page
3447 named <quote>index.html</quote> regardless of path which in this case can
3448 have one or more <quote>/'s</quote>. And this one must contain exactly
3449 <quote>.html</quote> (but does not have to end with that!).
3454 <term><literal>.example.com/(.*/)(ads|banners?|junk)</literal></term>
3457 This regular expression will match any path of <quote>example.com</quote>
3458 that contains any of the words <quote>ads</quote>, <quote>banner</quote>,
3459 <quote>banners</quote> (because of the <quote>?</quote>) or <quote>junk</quote>.
3460 The path does not have to end in these words, just contain them.
3465 <term><literal>.example.com/(.*/)(ads|banners?|junk)/.*\.(jpe?g|gif|png)$</literal></term>
3468 This is very much the same as above, except now it must end in either
3469 <quote>.jpg</quote>, <quote>.jpeg</quote>, <quote>.gif</quote> or <quote>.png</quote>. So this
3470 one is limited to common image formats.
3477 There are many, many good examples to be found in <filename>default.action</filename>,
3478 and more tutorials below in <link linkend="regex">Appendix on regular expressions</link>.
3483 <!-- ~ End section ~ -->
3486 <!-- ~~~~~ New section ~~~~~ -->
3487 <sect3 id="tag-pattern"><title>The Tag Pattern</title>
3490 Tag patterns are used to change the applying actions based on the
3491 request's tags. Tags can be created with either the
3492 <link linkend="CLIENT-HEADER-TAGGER">client-header-tagger</link>
3493 or the <link linkend="SERVER-HEADER-TAGGER">server-header-tagger</link> action.
3497 Tag patterns have to start with <quote>TAG:</quote>, so &my-app;
3498 can tell them apart from URL patterns. Everything after the colon
3499 including white space, is interpreted as a regular expression with
3500 path pattern syntax, except that tag patterns aren't left-anchored
3501 automatically (&my-app; doesn't silently add a <quote>^</quote>,
3502 you have to do it yourself if you need it).
3506 To match all requests that are tagged with <quote>foo</quote>
3507 your pattern line should be <quote>TAG:^foo$</quote>,
3508 <quote>TAG:foo</quote> would work as well, but it would also
3509 match requests whose tags contain <quote>foo</quote> somewhere.
3510 <quote>TAG: foo</quote> wouldn't work as it requires white space.
3514 Sections can contain URL and tag patterns at the same time,
3515 but tag patterns are checked after the URL patterns and thus
3516 always overrule them, even if they are located before the URL patterns.
3520 Once a new tag is added, Privoxy checks right away if it's matched by one
3521 of the tag patterns and updates the action settings accordingly. As a result
3522 tags can be used to activate other tagger actions, as long as these other
3523 taggers look for headers that haven't already be parsed.
3527 For example you could tag client requests which use the
3528 <literal>POST</literal> method,
3529 then use this tag to activate another tagger that adds a tag if cookies
3530 are sent, and then use a block action based on the cookie tag. This allows
3531 the outcome of one action, to be input into a subsequent action. However if
3532 you'd reverse the position of the described taggers, and activated the
3533 method tagger based on the cookie tagger, no method tags would be created.
3534 The method tagger would look for the request line, but at the time
3535 the cookie tag is created, the request line has already been parsed.
3539 While this is a limitation you should be aware of, this kind of
3540 indirection is seldom needed anyway and even the example doesn't
3541 make too much sense.
3548 <!-- ~ End section ~ -->
3551 <!-- ~~~~~ New section ~~~~~ -->
3553 <sect2 id="actions">
3554 <title>Actions</title>
3556 All actions are disabled by default, until they are explicitly enabled
3557 somewhere in an actions file. Actions are turned on if preceded with a
3558 <quote>+</quote>, and turned off if preceded with a <quote>-</quote>. So a
3559 <literal>+action</literal> means <quote>do that action</quote>, e.g.
3560 <literal>+block</literal> means <quote>please block URLs that match the
3561 following patterns</quote>, and <literal>-block</literal> means <quote>don't
3562 block URLs that match the following patterns, even if <literal>+block</literal>
3563 previously applied.</quote>
3568 Again, actions are invoked by placing them on a line, enclosed in curly braces and
3569 separated by whitespace, like in
3570 <literal>{+some-action -some-other-action{some-parameter}}</literal>,
3571 followed by a list of URL patterns, one per line, to which they apply.
3572 Together, the actions line and the following pattern lines make up a section
3573 of the actions file.
3577 Actions fall into three categories:
3584 Boolean, i.e the action can only be <quote>enabled</quote> or
3585 <quote>disabled</quote>. Syntax:
3589 +<replaceable class="function">name</replaceable> # enable action <replaceable class="parameter">name</replaceable>
3590 -<replaceable class="function">name</replaceable> # disable action <replaceable class="parameter">name</replaceable></screen>
3593 Example: <literal>+handle-as-image</literal>
3600 Parameterized, where some value is required in order to enable this type of action.
3605 +<replaceable class="function">name</replaceable>{<replaceable class="parameter">param</replaceable>} # enable action and set parameter to <replaceable class="parameter">param</replaceable>,
3606 # overwriting parameter from previous match if necessary
3607 -<replaceable class="function">name</replaceable> # disable action. The parameter can be omitted</screen>
3610 Note that if the URL matches multiple positive forms of a parameterized action,
3611 the last match wins, i.e. the params from earlier matches are simply ignored.
3614 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>
3620 Multi-value. These look exactly like parameterized actions,
3621 but they behave differently: If the action applies multiple times to the
3622 same URL, but with different parameters, <emphasis>all</emphasis> the parameters
3623 from <emphasis>all</emphasis> matches are remembered. This is used for actions
3624 that can be executed for the same request repeatedly, like adding multiple
3625 headers, or filtering through multiple filters. Syntax:
3629 +<replaceable class="function">name</replaceable>{<replaceable class="parameter">param</replaceable>} # enable action and add <replaceable class="parameter">param</replaceable> to the list of parameters
3630 -<replaceable class="function">name</replaceable>{<replaceable class="parameter">param</replaceable>} # remove the parameter <replaceable class="parameter">param</replaceable> from the list of parameters
3631 # If it was the last one left, disable the action.
3632 <replaceable class="parameter">-name</replaceable> # disable this action completely and remove all parameters from the list</screen>
3635 Examples: <literal>+add-header{X-Fun-Header: Some text}</literal> and
3636 <literal>+filter{html-annoyances}</literal>
3644 If nothing is specified in any actions file, no <quote>actions</quote> are
3645 taken. So in this case <application>Privoxy</application> would just be a
3646 normal, non-blocking, non-filtering proxy. You must specifically enable the
3647 privacy and blocking features you need (although the provided default actions
3648 files will give a good starting point).
3652 Later defined action sections always over-ride earlier ones of the same type.
3653 So exceptions to any rules you make, should come in the latter part of the file (or
3654 in a file that is processed later when using multiple actions files such
3655 as <filename>user.action</filename>). For multi-valued actions, the actions
3656 are applied in the order they are specified. Actions files are processed in
3657 the order they are defined in <filename>config</filename> (the default
3658 installation has three actions files). It also quite possible for any given
3659 URL to match more than one <quote>pattern</quote> (because of wildcards and
3660 regular expressions), and thus to trigger more than one set of actions! Last
3664 <!-- start actions listing -->
3666 The list of valid <application>Privoxy</application> actions are:
3670 <!-- ********************************************************** -->
3671 <!-- Please note the below defined actions use id's that are -->
3672 <!-- probably linked from other places, so please don't change. -->
3674 <!-- ********************************************************** -->
3677 <!-- ~~~~~ New section ~~~~~ -->
3679 <sect3 renderas="sect4" id="add-header">
3680 <title>add-header</title>
3684 <term>Typical use:</term>
3686 <para>Confuse log analysis, custom applications</para>
3691 <term>Effect:</term>
3694 Sends a user defined HTTP header to the web server.
3701 <!-- boolean, parameterized, Multi-value -->
3703 <para>Multi-value.</para>
3708 <term>Parameter:</term>
3711 Any string value is possible. Validity of the defined HTTP headers is not checked.
3712 It is recommended that you use the <quote><literal>X-</literal></quote> prefix
3722 This action may be specified multiple times, in order to define multiple
3723 headers. This is rarely needed for the typical user. If you don't know what
3724 <quote>HTTP headers</quote> are, you definitely don't need to worry about this
3728 Headers added by this action are not modified by other actions.
3734 <term>Example usage:</term>
3737 <screen>+add-header{X-User-Tracking: sucks}</screen>
3745 <!-- ~~~~~ New section ~~~~~ -->
3746 <sect3 renderas="sect4" id="block">
3747 <title>block</title>
3751 <term>Typical use:</term>
3753 <para>Block ads or other unwanted content</para>
3758 <term>Effect:</term>
3761 Requests for URLs to which this action applies are blocked, i.e. the
3762 requests are trapped by &my-app; and the requested URL is never retrieved,
3763 but is answered locally with a substitute page or image, as determined by
3765 linkend="handle-as-image">handle-as-image</link></literal>,
3767 linkend="set-image-blocker">set-image-blocker</link></literal>, and
3769 linkend="handle-as-empty-document">handle-as-empty-document</link></literal> actions.
3777 <!-- boolean, parameterized, Multi-value -->
3779 <para>Parameterized.</para>
3784 <term>Parameter:</term>
3786 <para>A block reason that should be given to the user.</para>
3794 <application>Privoxy</application> sends a special <quote>BLOCKED</quote> page
3795 for requests to blocked pages. This page contains the block reason given as
3796 parameter, a link to find out why the block action applies, and a click-through
3797 to the blocked content (the latter only if the force feature is available and
3801 A very important exception occurs if <emphasis>both</emphasis>
3802 <literal>block</literal> and <literal><link linkend="handle-as-image">handle-as-image</link></literal>,
3803 apply to the same request: it will then be replaced by an image. If
3804 <literal><link linkend="set-image-blocker">set-image-blocker</link></literal>
3805 (see below) also applies, the type of image will be determined by its parameter,
3806 if not, the standard checkerboard pattern is sent.
3809 It is important to understand this process, in order
3810 to understand how <application>Privoxy</application> deals with
3811 ads and other unwanted content. Blocking is a core feature, and one
3812 upon which various other features depend.
3815 The <literal><link linkend="filter">filter</link></literal>
3816 action can perform a very similar task, by <quote>blocking</quote>
3817 banner images and other content through rewriting the relevant URLs in the
3818 document's HTML source, so they don't get requested in the first place.
3819 Note that this is a totally different technique, and it's easy to confuse the two.
3825 <term>Example usage (section):</term>
3828 <screen>{+block{No nasty stuff for you.}}
3829 # Block and replace with "blocked" page
3830 .nasty-stuff.example.com
3832 {+block{Doubleclick banners.} +handle-as-image}
3833 # Block and replace with image
3837 {+block{Layered ads.} +handle-as-empty-document}
3838 # Block and then ignore
3839 adserver.example.net/.*\.js$</screen>
3849 <!-- ~~~~~ New section ~~~~~ -->
3850 <sect3 renderas="sect4" id="change-x-forwarded-for">
3851 <title>change-x-forwarded-for</title>
3855 <term>Typical use:</term>
3857 <para>Improve privacy by not forwarding the source of the request in the HTTP headers.</para>
3862 <term>Effect:</term>
3865 Deletes the <quote>X-Forwarded-For:</quote> HTTP header from the client request,
3873 <!-- Boolean, Parameterized, Multi-value -->
3875 <para>Parameterized.</para>
3880 <term>Parameter:</term>
3884 <para><quote>block</quote> to delete the header.</para>
3888 <quote>add</quote> to create the header (or append
3889 the client's IP address to an already existing one).
3900 It is safe and recommended to use <literal>block</literal>.
3903 Forwarding the source address of the request may make
3904 sense in some multi-user setups but is also a privacy risk.
3909 <term>Example usage:</term>
3912 <screen>+change-x-forwarded-for{block}</screen>
3919 <!-- ~~~~~ New section ~~~~~ -->
3920 <sect3 renderas="sect4" id="client-header-filter">
3921 <title>client-header-filter</title>
3925 <term>Typical use:</term>
3928 Rewrite or remove single client headers.
3934 <term>Effect:</term>
3937 All client headers to which this action applies are filtered on-the-fly through
3938 the specified regular expression based substitutions.
3945 <!-- boolean, parameterized, Multi-value -->
3947 <para>Parameterized.</para>
3952 <term>Parameter:</term>
3955 The name of a client-header filter, as defined in one of the
3956 <link linkend="filter-file">filter files</link>.
3965 Client-header filters are applied to each header on its own, not to
3966 all at once. This makes it easier to diagnose problems, but on the downside
3967 you can't write filters that only change header x if header y's value is z.
3968 You can do that by using tags though.
3971 Client-header filters are executed after the other header actions have finished
3972 and use their output as input.
3975 If the request URI gets changed, &my-app; will detect that and use the new
3976 one. This can be used to rewrite the request destination behind the client's
3977 back, for example to specify a Tor exit relay for certain requests.
3980 Please refer to the <link linkend="filter-file">filter file chapter</link>
3981 to learn which client-header filters are available by default, and how to
3989 <term>Example usage (section):</term>
3993 # Hide Tor exit notation in Host and Referer Headers
3994 {+client-header-filter{hide-tor-exit-notation}}
4005 <!-- ~~~~~ New section ~~~~~ -->
4006 <sect3 renderas="sect4" id="client-header-tagger">
4007 <title>client-header-tagger</title>
4011 <term>Typical use:</term>
4014 Block requests based on their headers.
4020 <term>Effect:</term>
4023 Client headers to which this action applies are filtered on-the-fly through
4024 the specified regular expression based substitutions, the result is used as
4032 <!-- boolean, parameterized, Multi-value -->
4034 <para>Parameterized.</para>
4039 <term>Parameter:</term>
4042 The name of a client-header tagger, as defined in one of the
4043 <link linkend="filter-file">filter files</link>.
4052 Client-header taggers are applied to each header on its own,
4053 and as the header isn't modified, each tagger <quote>sees</quote>
4057 Client-header taggers are the first actions that are executed
4058 and their tags can be used to control every other action.
4064 <term>Example usage (section):</term>
4068 # Tag every request with the User-Agent header
4069 {+client-header-tagger{user-agent}}
4072 # Tagging itself doesn't change the action
4073 # settings, sections with TAG patterns do:
4075 # If it's a download agent, use a different forwarding proxy,
4076 # show the real User-Agent and make sure resume works.
4077 {+forward-override{forward-socks5 10.0.0.2:2222 .} \
4078 -hide-if-modified-since \
4079 -overwrite-last-modified \
4084 TAG:^User-Agent: NetBSD-ftp/
4085 TAG:^User-Agent: Novell ZYPP Installer
4086 TAG:^User-Agent: RPM APT-HTTP/
4087 TAG:^User-Agent: fetch libfetch/
4088 TAG:^User-Agent: Ubuntu APT-HTTP/
4089 TAG:^User-Agent: MPlayer/
4094 # Tag all requests with the Range header set
4095 {+client-header-tagger{range-requests}}
4098 # Disable filtering for the tagged requests.
4100 # With filtering enabled Privoxy would remove the Range headers
4101 # to be able to filter the whole response. The downside is that
4102 # it prevents clients from resuming downloads or skipping over
4103 # parts of multimedia files.
4104 {-filter -deanimate-gifs}
4115 <!-- ~~~~~ New section ~~~~~ -->
4116 <sect3 renderas="sect4" id="content-type-overwrite">
4117 <title>content-type-overwrite</title>
4121 <term>Typical use:</term>
4123 <para>Stop useless download menus from popping up, or change the browser's rendering mode</para>
4128 <term>Effect:</term>
4131 Replaces the <quote>Content-Type:</quote> HTTP server header.
4138 <!-- Boolean, Parameterized, Multi-value -->
4140 <para>Parameterized.</para>
4145 <term>Parameter:</term>
4157 The <quote>Content-Type:</quote> HTTP server header is used by the
4158 browser to decide what to do with the document. The value of this
4159 header can cause the browser to open a download menu instead of
4160 displaying the document by itself, even if the document's format is
4161 supported by the browser.
4164 The declared content type can also affect which rendering mode
4165 the browser chooses. If XHTML is delivered as <quote>text/html</quote>,
4166 many browsers treat it as yet another broken HTML document.
4167 If it is send as <quote>application/xml</quote>, browsers with
4168 XHTML support will only display it, if the syntax is correct.
4171 If you see a web site that proudly uses XHTML buttons, but sets
4172 <quote>Content-Type: text/html</quote>, you can use &my-app;
4173 to overwrite it with <quote>application/xml</quote> and validate
4174 the web master's claim inside your XHTML-supporting browser.
4175 If the syntax is incorrect, the browser will complain loudly.
4178 You can also go the opposite direction: if your browser prints
4179 error messages instead of rendering a document falsely declared
4180 as XHTML, you can overwrite the content type with
4181 <quote>text/html</quote> and have it rendered as broken HTML document.
4184 By default <literal>content-type-overwrite</literal> only replaces
4185 <quote>Content-Type:</quote> headers that look like some kind of text.
4186 If you want to overwrite it unconditionally, you have to combine it with
4187 <literal><link linkend="force-text-mode">force-text-mode</link></literal>.
4188 This limitation exists for a reason, think twice before circumventing it.
4191 Most of the time it's easier to replace this action with a custom
4192 <literal><link linkend="server-header-filter">server-header filter</link></literal>.
4193 It allows you to activate it for every document of a certain site and it will still
4194 only replace the content types you aimed at.
4197 Of course you can apply <literal>content-type-overwrite</literal>
4198 to a whole site and then make URL based exceptions, but it's a lot
4199 more work to get the same precision.
4205 <term>Example usage (sections):</term>
4208 <screen># Check if www.example.net/ really uses valid XHTML
4209 { +content-type-overwrite{application/xml} }
4212 # but leave the content type unmodified if the URL looks like a style sheet
4213 {-content-type-overwrite}
4214 www.example.net/.*\.css$
4215 www.example.net/.*style
4224 <!-- ~~~~~ New section ~~~~~ -->
4225 <sect3 renderas="sect4" id="crunch-client-header">
4229 <title>crunch-client-header</title>
4233 <term>Typical use:</term>
4235 <para>Remove a client header <application>Privoxy</application> has no dedicated action for.</para>
4240 <term>Effect:</term>
4243 Deletes every header sent by the client that contains the string the user supplied as parameter.
4250 <!-- Boolean, Parameterized, Multi-value -->
4252 <para>Parameterized.</para>
4257 <term>Parameter:</term>
4269 This action allows you to block client headers for which no dedicated
4270 <application>Privoxy</application> action exists.
4271 <application>Privoxy</application> will remove every client header that
4272 contains the string you supplied as parameter.
4275 Regular expressions are <emphasis>not supported</emphasis> and you can't
4276 use this action to block different headers in the same request, unless
4277 they contain the same string.
4280 <literal>crunch-client-header</literal> is only meant for quick tests.
4281 If you have to block several different headers, or only want to modify
4282 parts of them, you should use a
4283 <literal><link linkend="client-header-filter">client-header filter</link></literal>.
4287 Don't block any header without understanding the consequences.
4294 <term>Example usage (section):</term>
4297 <screen># Block the non-existent "Privacy-Violation:" client header
4298 { +crunch-client-header{Privacy-Violation:} }
4308 <!-- ~~~~~ New section ~~~~~ -->
4309 <sect3 renderas="sect4" id="crunch-if-none-match">
4310 <title>crunch-if-none-match</title>
4316 <term>Typical use:</term>
4318 <para>Prevent yet another way to track the user's steps between sessions.</para>
4323 <term>Effect:</term>
4326 Deletes the <quote>If-None-Match:</quote> HTTP client header.
4333 <!-- Boolean, Parameterized, Multi-value -->
4335 <para>Boolean.</para>
4340 <term>Parameter:</term>
4352 Removing the <quote>If-None-Match:</quote> HTTP client header
4353 is useful for filter testing, where you want to force a real
4354 reload instead of getting status code <quote>304</quote> which
4355 would cause the browser to use a cached copy of the page.
4358 It is also useful to make sure the header isn't used as a cookie
4359 replacement (unlikely but possible).
4362 Blocking the <quote>If-None-Match:</quote> header shouldn't cause any
4363 caching problems, as long as the <quote>If-Modified-Since:</quote> header
4364 isn't blocked or missing as well.
4367 It is recommended to use this action together with
4368 <literal><link linkend="hide-if-modified-since">hide-if-modified-since</link></literal>
4370 <literal><link linkend="overwrite-last-modified">overwrite-last-modified</link></literal>.
4376 <term>Example usage (section):</term>
4379 <screen># Let the browser revalidate cached documents but don't
4380 # allow the server to use the revalidation headers for user tracking.
4381 {+hide-if-modified-since{-60} \
4382 +overwrite-last-modified{randomize} \
4383 +crunch-if-none-match}
4392 <!-- ~~~~~ New section ~~~~~ -->
4393 <sect3 renderas="sect4" id="crunch-incoming-cookies">
4394 <title>crunch-incoming-cookies</title>
4398 <term>Typical use:</term>
4401 Prevent the web server from setting HTTP cookies on your system
4407 <term>Effect:</term>
4410 Deletes any <quote>Set-Cookie:</quote> HTTP headers from server replies.
4417 <!-- Boolean, Parameterized, Multi-value -->
4419 <para>Boolean.</para>
4424 <term>Parameter:</term>
4436 This action is only concerned with <emphasis>incoming</emphasis> HTTP cookies. For
4437 <emphasis>outgoing</emphasis> HTTP cookies, use
4438 <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal>.
4439 Use <emphasis>both</emphasis> to disable HTTP cookies completely.
4442 It makes <emphasis>no sense at all</emphasis> to use this action in conjunction
4443 with the <literal><link linkend="session-cookies-only">session-cookies-only</link></literal> action,
4444 since it would prevent the session cookies from being set. See also
4445 <literal><link linkend="filter-content-cookies">filter-content-cookies</link></literal>.
4451 <term>Example usage:</term>
4454 <screen>+crunch-incoming-cookies</screen>
4462 <!-- ~~~~~ New section ~~~~~ -->
4463 <sect3 renderas="sect4" id="crunch-server-header">
4464 <title>crunch-server-header</title>
4470 <term>Typical use:</term>
4472 <para>Remove a server header <application>Privoxy</application> has no dedicated action for.</para>
4477 <term>Effect:</term>
4480 Deletes every header sent by the server that contains the string the user supplied as parameter.
4487 <!-- Boolean, Parameterized, Multi-value -->
4489 <para>Parameterized.</para>
4494 <term>Parameter:</term>
4506 This action allows you to block server headers for which no dedicated
4507 <application>Privoxy</application> action exists. <application>Privoxy</application>
4508 will remove every server header that contains the string you supplied as parameter.
4511 Regular expressions are <emphasis>not supported</emphasis> and you can't
4512 use this action to block different headers in the same request, unless
4513 they contain the same string.
4516 <literal>crunch-server-header</literal> is only meant for quick tests.
4517 If you have to block several different headers, or only want to modify
4518 parts of them, you should use a custom
4519 <literal><link linkend="server-header-filter">server-header filter</link></literal>.
4523 Don't block any header without understanding the consequences.
4530 <term>Example usage (section):</term>
4533 <screen># Crunch server headers that try to prevent caching
4534 { +crunch-server-header{no-cache} }
4543 <!-- ~~~~~ New section ~~~~~ -->
4544 <sect3 renderas="sect4" id="crunch-outgoing-cookies">
4545 <title>crunch-outgoing-cookies</title>
4549 <term>Typical use:</term>
4552 Prevent the web server from reading any HTTP cookies from your system
4558 <term>Effect:</term>
4561 Deletes any <quote>Cookie:</quote> HTTP headers from client requests.
4568 <!-- Boolean, Parameterized, Multi-value -->
4570 <para>Boolean.</para>
4575 <term>Parameter:</term>
4587 This action is only concerned with <emphasis>outgoing</emphasis> HTTP cookies. For
4588 <emphasis>incoming</emphasis> HTTP cookies, use
4589 <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal>.
4590 Use <emphasis>both</emphasis> to disable HTTP cookies completely.
4593 It makes <emphasis>no sense at all</emphasis> to use this action in conjunction
4594 with the <literal><link linkend="session-cookies-only">session-cookies-only</link></literal> action,
4595 since it would prevent the session cookies from being read.
4601 <term>Example usage:</term>
4604 <screen>+crunch-outgoing-cookies</screen>
4613 <!-- ~~~~~ New section ~~~~~ -->
4614 <sect3 renderas="sect4" id="deanimate-gifs">
4615 <title>deanimate-gifs</title>
4619 <term>Typical use:</term>
4621 <para>Stop those annoying, distracting animated GIF images.</para>
4626 <term>Effect:</term>
4629 De-animate GIF animations, i.e. reduce them to their first or last image.
4636 <!-- boolean, parameterized, Multi-value -->
4638 <para>Parameterized.</para>
4643 <term>Parameter:</term>
4646 <quote>last</quote> or <quote>first</quote>
4655 This will also shrink the images considerably (in bytes, not pixels!). If
4656 the option <quote>first</quote> is given, the first frame of the animation
4657 is used as the replacement. If <quote>last</quote> is given, the last
4658 frame of the animation is used instead, which probably makes more sense for
4659 most banner animations, but also has the risk of not showing the entire
4660 last frame (if it is only a delta to an earlier frame).
4663 You can safely use this action with patterns that will also match non-GIF
4664 objects, because no attempt will be made at anything that doesn't look like
4671 <term>Example usage:</term>
4674 <screen>+deanimate-gifs{last}</screen>
4681 <!-- ~~~~~ New section ~~~~~ -->
4682 <sect3 renderas="sect4" id="downgrade-http-version">
4683 <title>downgrade-http-version</title>
4687 <term>Typical use:</term>
4689 <para>Work around (very rare) problems with HTTP/1.1</para>
4694 <term>Effect:</term>
4697 Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0.
4704 <!-- boolean, parameterized, Multi-value -->
4706 <para>Boolean.</para>
4711 <term>Parameter:</term>
4723 This is a left-over from the time when <application>Privoxy</application>
4724 didn't support important HTTP/1.1 features well. It is left here for the
4725 unlikely case that you experience HTTP/1.1-related problems with some server
4729 Note that enabling this action is only a workaround. It should not
4730 be enabled for sites that work without it. While it shouldn't break
4731 any pages, it has an (usually negative) performance impact.
4734 If you come across a site where enabling this action helps, please report it,
4735 so the cause of the problem can be analyzed. If the problem turns out to be
4736 caused by a bug in <application>Privoxy</application> it should be
4737 fixed so the following release works without the work around.
4743 <term>Example usage (section):</term>
4746 <screen>{+downgrade-http-version}
4747 problem-host.example.com</screen>
4755 <!-- ~~~~~ New section ~~~~~ -->
4756 <sect3 renderas="sect4" id="fast-redirects">
4757 <title>fast-redirects</title>
4761 <term>Typical use:</term>
4763 <para>Fool some click-tracking scripts and speed up indirect links.</para>
4768 <term>Effect:</term>
4771 Detects redirection URLs and redirects the browser without contacting
4772 the redirection server first.
4779 <!-- boolean, parameterized, Multi-value -->
4781 <para>Parameterized.</para>
4786 <term>Parameter:</term>
4791 <quote>simple-check</quote> to just search for the string <quote>http://</quote>
4792 to detect redirection URLs.
4797 <quote>check-decoded-url</quote> to decode URLs (if necessary) before searching
4798 for redirection URLs.
4809 Many sites, like yahoo.com, don't just link to other sites. Instead, they
4810 will link to some script on their own servers, giving the destination as a
4811 parameter, which will then redirect you to the final target. URLs
4812 resulting from this scheme typically look like:
4813 <quote>http://www.example.org/click-tracker.cgi?target=http%3a//www.example.net/</quote>.
4816 Sometimes, there are even multiple consecutive redirects encoded in the
4817 URL. These redirections via scripts make your web browsing more traceable,
4818 since the server from which you follow such a link can see where you go
4819 to. Apart from that, valuable bandwidth and time is wasted, while your
4820 browser asks the server for one redirect after the other. Plus, it feeds
4824 This feature is currently not very smart and is scheduled for improvement.
4825 If it is enabled by default, you will have to create some exceptions to
4826 this action. It can lead to failures in several ways:
4829 Not every URLs with other URLs as parameters is evil.
4830 Some sites offer a real service that requires this information to work.
4831 For example a validation service needs to know, which document to validate.
4832 <literal>fast-redirects</literal> assumes that every URL parameter that
4833 looks like another URL is a redirection target, and will always redirect to
4834 the last one. Most of the time the assumption is correct, but if it isn't,
4835 the user gets redirected anyway.
4838 Another failure occurs if the URL contains other parameters after the URL parameter.
4840 <quote>http://www.example.org/?redirect=http%3a//www.example.net/&foo=bar</quote>.
4841 contains the redirection URL <quote>http://www.example.net/</quote>,
4842 followed by another parameter. <literal>fast-redirects</literal> doesn't know that
4843 and will cause a redirect to <quote>http://www.example.net/&foo=bar</quote>.
4844 Depending on the target server configuration, the parameter will be silently ignored
4845 or lead to a <quote>page not found</quote> error. You can prevent this problem by
4846 first using the <literal><link linkend="redirect">redirect</link></literal> action
4847 to remove the last part of the URL, but it requires a little effort.
4850 To detect a redirection URL, <literal>fast-redirects</literal> only
4851 looks for the string <quote>http://</quote>, either in plain text
4852 (invalid but often used) or encoded as <quote>http%3a//</quote>.
4853 Some sites use their own URL encoding scheme, encrypt the address
4854 of the target server or replace it with a database id. In theses cases
4855 <literal>fast-redirects</literal> is fooled and the request reaches the
4856 redirection server where it probably gets logged.
4862 <term>Example usage:</term>
4866 { +fast-redirects{simple-check} }
4869 { +fast-redirects{check-decoded-url} }
4870 another.example.com/testing</screen>
4879 <!-- ~~~~~ New section ~~~~~ -->
4880 <sect3 renderas="sect4" id="filter">
4881 <title>filter</title>
4885 <term>Typical use:</term>
4887 <para>Get rid of HTML and JavaScript annoyances, banner advertisements (by size),
4888 do fun text replacements, add personalized effects, etc.</para>
4893 <term>Effect:</term>
4896 All instances of text-based type, most notably HTML and JavaScript, to which
4897 this action applies, can be filtered on-the-fly through the specified regular
4898 expression based substitutions. (Note: as of version 3.0.3 plain text documents
4899 are exempted from filtering, because web servers often use the
4900 <literal>text/plain</literal> MIME type for all files whose type they don't know.)
4907 <!-- boolean, parameterized, Multi-value -->
4909 <para>Parameterized.</para>
4914 <term>Parameter:</term>
4917 The name of a content filter, as defined in the <link linkend="filter-file">filter file</link>.
4918 Filters can be defined in one or more files as defined by the
4919 <literal><link linkend="filterfile">filterfile</link></literal>
4920 option in the <link linkend="config">config file</link>.
4921 <filename>default.filter</filename> is the collection of filters
4922 supplied by the developers. Locally defined filters should go
4923 in their own file, such as <filename>user.filter</filename>.
4926 When used in its negative form,
4927 and without parameters, <emphasis>all</emphasis> filtering is completely disabled.
4936 For your convenience, there are a number of pre-defined filters available
4937 in the distribution filter file that you can use. See the examples below for
4941 Filtering requires buffering the page content, which may appear to
4942 slow down page rendering since nothing is displayed until all content has
4943 passed the filters. (The total time until the page is completely rendered
4944 doesn't change much, but it may be perceived as slower since the page is
4945 not incrementally displayed.)
4946 This effect will be more noticeable on slower connections.
4949 <quote>Rolling your own</quote>
4950 filters requires a knowledge of
4951 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
4952 Expressions</quote></ulink> and
4953 <ulink url="http://en.wikipedia.org/wiki/Html"><quote>HTML</quote></ulink>.
4954 This is very powerful feature, and potentially very intrusive.
4955 Filters should be used with caution, and where an equivalent
4956 <quote>action</quote> is not available.
4959 The amount of data that can be filtered is limited to the
4960 <literal><link linkend="buffer-limit">buffer-limit</link></literal>
4961 option in the main <link linkend="config">config file</link>. The
4962 default is 4096 KB (4 Megs). Once this limit is exceeded, the buffered
4963 data, and all pending data, is passed through unfiltered.
4966 Inappropriate MIME types, such as zipped files, are not filtered at all.
4967 (Again, only text-based types except plain text). Encrypted SSL data
4968 (from HTTPS servers) cannot be filtered either, since this would violate
4969 the integrity of the secure transaction. In some situations it might
4970 be necessary to protect certain text, like source code, from filtering
4971 by defining appropriate <literal>-filter</literal> exceptions.
4974 Compressed content can't be filtered either, but if &my-app;
4975 is compiled with zlib support and a supported compression algorithm
4976 is used (gzip or deflate), &my-app; can first decompress the content
4980 If you use a &my-app; version without zlib support, but want filtering to work on
4981 as much documents as possible, even those that would normally be sent compressed,
4982 you must use the <literal><link linkend="prevent-compression">prevent-compression</link></literal>
4983 action in conjunction with <literal>filter</literal>.
4986 Content filtering can achieve some of the same effects as the
4987 <literal><link linkend="block">block</link></literal>
4988 action, i.e. it can be used to block ads and banners. But the mechanism
4989 works quite differently. One effective use, is to block ad banners
4990 based on their size (see below), since many of these seem to be somewhat
4994 <link linkend="contact">Feedback</link> with suggestions for new or
4995 improved filters is particularly welcome!
4998 The below list has only the names and a one-line description of each
4999 predefined filter. There are <link linkend="predefined-filters">more
5000 verbose explanations</link> of what these filters do in the <link
5001 linkend="filter-file">filter file chapter</link>.
5007 <term>Example usage (with filters from the distribution <filename>default.filter</filename> file).
5008 See <link linkend="PREDEFINED-FILTERS">the Predefined Filters section</link> for
5009 more explanation on each:</term>
5012 <anchor id="filter-js-annoyances">
5013 <screen>+filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse.</screen>
5016 <anchor id="filter-js-events">
5017 <screen>+filter{js-events} # Kill all JS event bindings and timers (Radically destructive! Only for extra nasty sites).</screen>
5020 <anchor id="filter-html-annoyances">
5021 <screen>+filter{html-annoyances} # Get rid of particularly annoying HTML abuse.</screen>
5024 <anchor id="filter-content-cookies">
5025 <screen>+filter{content-cookies} # Kill cookies that come in the HTML or JS content.</screen>
5028 <anchor id="filter-refresh-tags">
5029 <screen>+filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups).</screen>
5032 <anchor id="filter-unsolicited-popups">
5033 <screen>+filter{unsolicited-popups} # Disable only unsolicited pop-up windows. Useful if your browser lacks this ability.</screen>
5036 <anchor id="filter-all-popups">
5037 <screen>+filter{all-popups} # Kill all popups in JavaScript and HTML. Useful if your browser lacks this ability.</screen>
5040 <anchor id="filter-img-reorder">
5041 <screen>+filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective.</screen>
5044 <anchor id="filter-banners-by-size">
5045 <screen>+filter{banners-by-size} # Kill banners by size.</screen>
5048 <anchor id="filter-banners-by-link">
5049 <screen>+filter{banners-by-link} # Kill banners by their links to known clicktrackers.</screen>
5052 <anchor id="filter-webbugs">
5053 <screen>+filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking).</screen>
5056 <anchor id="filter-tiny-textforms">
5057 <screen>+filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap.</screen>
5060 <anchor id="filter-jumping-windows">
5061 <screen>+filter{jumping-windows} # Prevent windows from resizing and moving themselves.</screen>
5064 <anchor id="filter-frameset-borders">
5065 <screen>+filter{frameset-borders} # Give frames a border and make them resizable.</screen>
5068 <anchor id="filter-demoronizer">
5069 <screen>+filter{demoronizer} # Fix MS's non-standard use of standard charsets.</screen>
5072 <anchor id="filter-shockwave-flash">
5073 <screen>+filter{shockwave-flash} # Kill embedded Shockwave Flash objects.</screen>
5076 <anchor id="filter-quicktime-kioskmode">
5077 <screen>+filter{quicktime-kioskmode} # Make Quicktime movies saveable.</screen>
5080 <anchor id="filter-fun">
5081 <screen>+filter{fun} # Text replacements for subversive browsing fun!</screen>
5084 <anchor id="filter-crude-parental">
5085 <screen>+filter{crude-parental} # Crude parental filtering. Note that this filter doesn't work reliably.</screen>
5088 <anchor id="filter-ie-exploits">
5089 <screen>+filter{ie-exploits} # Disable some known Internet Explorer bug exploits.</screen>
5092 <anchor id="filter-site-specifics">
5093 <screen>+filter{site-specifics} # Cure for site-specific problems. Don't apply generally!</screen>
5096 <anchor id="filter-no-ping">
5097 <screen>+filter{no-ping} # Removes non-standard ping attributes in <a> and <area> tags.</screen>
5100 <anchor id="filter-google">
5101 <screen>+filter{google} # CSS-based block for Google text ads. Also removes a width limitation and the toolbar advertisement.</screen>
5104 <anchor id="filter-yahoo">
5105 <screen>+filter{yahoo} # CSS-based block for Yahoo text ads. Also removes a width limitation.</screen>
5108 <anchor id="filter-msn">
5109 <screen>+filter{msn} # CSS-based block for MSN text ads. Also removes tracking URLs and a width limitation.</screen>
5112 <anchor id="filter-blogspot">
5113 <screen>+filter{blogspot} # Cleans up some Blogspot blogs. Read the fine print before using this.</screen>
5121 <!-- ~~~~~ New section ~~~~~ -->
5122 <sect3 renderas="sect4" id="force-text-mode">
5123 <title>force-text-mode</title>
5129 <term>Typical use:</term>
5131 <para>Force <application>Privoxy</application> to treat a document as if it was in some kind of <emphasis>text</emphasis> format. </para>
5136 <term>Effect:</term>
5139 Declares a document as text, even if the <quote>Content-Type:</quote> isn't detected as such.
5146 <!-- Boolean, Parameterized, Multi-value -->
5148 <para>Boolean.</para>
5153 <term>Parameter:</term>
5165 As explained <literal><link linkend="filter">above</link></literal>,
5166 <application>Privoxy</application> tries to only filter files that are
5167 in some kind of text format. The same restrictions apply to
5168 <literal><link linkend="content-type-overwrite">content-type-overwrite</link></literal>.
5169 <literal>force-text-mode</literal> declares a document as text,
5170 without looking at the <quote>Content-Type:</quote> first.
5174 Think twice before activating this action. Filtering binary data
5175 with regular expressions can cause file damage.
5182 <term>Example usage:</term>
5195 <!-- ~~~~~ New section ~~~~~ -->
5196 <sect3 renderas="sect4" id="forward-override">
5197 <title>forward-override</title>
5203 <term>Typical use:</term>
5205 <para>Change the forwarding settings based on User-Agent or request origin</para>
5210 <term>Effect:</term>
5213 Overrules the forward directives in the configuration file.
5220 <!-- Boolean, Parameterized, Multi-value -->
5222 <para>Multi-value.</para>
5227 <term>Parameter:</term>
5231 <para><quote>forward .</quote> to use a direct connection without any additional proxies.</para>
5235 <quote>forward 127.0.0.1:8123</quote> to use the HTTP proxy listening at 127.0.0.1 port 8123.
5240 <quote>forward-socks4a 127.0.0.1:9050 .</quote> to use the socks4a proxy listening at
5241 127.0.0.1 port 9050. Replace <quote>forward-socks4a</quote> with <quote>forward-socks4</quote>
5242 to use a socks4 connection (with local DNS resolution) instead, use <quote>forward-socks5</quote>
5243 for socks5 connections (with remote DNS resolution).
5248 <quote>forward-socks4a 127.0.0.1:9050 proxy.example.org:8000</quote> to use the socks4a proxy
5249 listening at 127.0.0.1 port 9050 to reach the HTTP proxy listening at proxy.example.org port 8000.
5250 Replace <quote>forward-socks4a</quote> with <quote>forward-socks4</quote> to use a socks4 connection
5251 (with local DNS resolution) instead, use <quote>forward-socks5</quote>
5252 for socks5 connections (with remote DNS resolution).
5263 This action takes parameters similar to the
5264 <link linkend="forwarding">forward</link> directives in the configuration
5265 file, but without the URL pattern. It can be used as replacement, but normally it's only
5266 used in cases where matching based on the request URL isn't sufficient.
5270 Please read the description for the <link linkend="forwarding">forward</link> directives before
5271 using this action. Forwarding to the wrong people will reduce your privacy and increase the
5272 chances of man-in-the-middle attacks.
5275 If the ports are missing or invalid, default values will be used. This might change
5276 in the future and you shouldn't rely on it. Otherwise incorrect syntax causes Privoxy
5280 Use the <ulink url="http://config.privoxy.org/show-url-info">show-url-info CGI page</ulink>
5281 to verify that your forward settings do what you thought the do.
5288 <term>Example usage:</term>
5292 # Always use direct connections for requests previously tagged as
5293 # <quote>User-Agent: fetch libfetch/2.0</quote> and make sure
5294 # resuming downloads continues to work.
5295 # This way you can continue to use Tor for your normal browsing,
5296 # without overloading the Tor network with your FreeBSD ports updates
5297 # or downloads of bigger files like ISOs.
5298 # Note that HTTP headers are easy to fake and therefore their
5299 # values are as (un)trustworthy as your clients and users.
5300 {+forward-override{forward .} \
5301 -hide-if-modified-since \
5302 -overwrite-last-modified \
5304 TAG:^User-Agent: fetch libfetch/2\.0$
5313 <!-- ~~~~~ New section ~~~~~ -->
5314 <sect3 renderas="sect4" id="handle-as-empty-document">
5315 <title>handle-as-empty-document</title>
5321 <term>Typical use:</term>
5323 <para>Mark URLs that should be replaced by empty documents <emphasis>if they get blocked</emphasis></para>
5328 <term>Effect:</term>
5331 This action alone doesn't do anything noticeable. It just marks URLs.
5332 If the <literal><link linkend="block">block</link></literal> action <emphasis>also applies</emphasis>,
5333 the presence or absence of this mark decides whether an HTML <quote>BLOCKED</quote>
5334 page, or an empty document will be sent to the client as a substitute for the blocked content.
5335 The <emphasis>empty</emphasis> document isn't literally empty, but actually contains a single space.
5342 <!-- Boolean, Parameterized, Multi-value -->
5344 <para>Boolean.</para>
5349 <term>Parameter:</term>
5361 Some browsers complain about syntax errors if JavaScript documents
5362 are blocked with <application>Privoxy's</application>
5363 default HTML page; this option can be used to silence them.
5364 And of course this action can also be used to eliminate the &my-app;
5365 BLOCKED message in frames.
5368 The content type for the empty document can be specified with
5369 <literal><link linkend="content-type-overwrite">content-type-overwrite{}</link></literal>,
5370 but usually this isn't necessary.
5376 <term>Example usage:</term>
5379 <screen># Block all documents on example.org that end with ".js",
5380 # but send an empty document instead of the usual HTML message.
5381 {+block{Blocked JavaScript} +handle-as-empty-document}
5391 <!-- ~~~~~ New section ~~~~~ -->
5392 <sect3 renderas="sect4" id="handle-as-image">
5393 <title>handle-as-image</title>
5397 <term>Typical use:</term>
5399 <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>
5404 <term>Effect:</term>
5407 This action alone doesn't do anything noticeable. It just marks URLs as images.
5408 If the <literal><link linkend="block">block</link></literal> action <emphasis>also applies</emphasis>,
5409 the presence or absence of this mark decides whether an HTML <quote>blocked</quote>
5410 page, or a replacement image (as determined by the <literal><link
5411 linkend="set-image-blocker">set-image-blocker</link></literal> action) will be sent to the
5412 client as a substitute for the blocked content.
5419 <!-- Boolean, Parameterized, Multi-value -->
5421 <para>Boolean.</para>
5426 <term>Parameter:</term>
5438 The below generic example section is actually part of <filename>default.action</filename>.
5439 It marks all URLs with well-known image file name extensions as images and should
5443 Users will probably only want to use the handle-as-image action in conjunction with
5444 <literal><link linkend="block">block</link></literal>, to block sources of banners, whose URLs don't
5445 reflect the file type, like in the second example section.
5448 Note that you cannot treat HTML pages as images in most cases. For instance, (in-line) ad
5449 frames require an HTML page to be sent, or they won't display properly.
5450 Forcing <literal>handle-as-image</literal> in this situation will not replace the
5451 ad frame with an image, but lead to error messages.
5457 <term>Example usage (sections):</term>
5460 <screen># Generic image extensions:
5463 /.*\.(gif|jpg|jpeg|png|bmp|ico)$
5465 # These don't look like images, but they're banners and should be
5466 # blocked as images:
5468 {+block{Nasty banners.} +handle-as-image}
5469 nasty-banner-server.example.com/junk.cgi\?output=trash
5478 <!-- ~~~~~ New section ~~~~~ -->
5479 <sect3 renderas="sect4" id="hide-accept-language">
5480 <title>hide-accept-language</title>
5486 <term>Typical use:</term>
5488 <para>Pretend to use different language settings.</para>
5493 <term>Effect:</term>
5496 Deletes or replaces the <quote>Accept-Language:</quote> HTTP header in client requests.
5503 <!-- Boolean, Parameterized, Multi-value -->
5505 <para>Parameterized.</para>
5510 <term>Parameter:</term>
5513 Keyword: <quote>block</quote>, or any user defined value.
5522 Faking the browser's language settings can be useful to make a
5523 foreign User-Agent set with
5524 <literal><link linkend="hide-user-agent">hide-user-agent</link></literal>
5528 However some sites with content in different languages check the
5529 <quote>Accept-Language:</quote> to decide which one to take by default.
5530 Sometimes it isn't possible to later switch to another language without
5531 changing the <quote>Accept-Language:</quote> header first.
5534 Therefore it's a good idea to either only change the
5535 <quote>Accept-Language:</quote> header to languages you understand,
5536 or to languages that aren't wide spread.
5539 Before setting the <quote>Accept-Language:</quote> header
5540 to a rare language, you should consider that it helps to
5541 make your requests unique and thus easier to trace.
5542 If you don't plan to change this header frequently,
5543 you should stick to a common language.
5549 <term>Example usage (section):</term>
5552 <screen># Pretend to use Canadian language settings.
5553 {+hide-accept-language{en-ca} \
5554 +hide-user-agent{Mozilla/5.0 (X11; U; OpenBSD i386; en-CA; rv:1.8.0.4) Gecko/20060628 Firefox/1.5.0.4} \
5564 <!-- ~~~~~ New section ~~~~~ -->
5565 <sect3 renderas="sect4" id="hide-content-disposition">
5566 <title>hide-content-disposition</title>
5572 <term>Typical use:</term>
5574 <para>Prevent download menus for content you prefer to view inside the browser.</para>
5579 <term>Effect:</term>
5582 Deletes or replaces the <quote>Content-Disposition:</quote> HTTP header set by some servers.
5589 <!-- Boolean, Parameterized, Multi-value -->
5591 <para>Parameterized.</para>
5596 <term>Parameter:</term>
5599 Keyword: <quote>block</quote>, or any user defined value.
5608 Some servers set the <quote>Content-Disposition:</quote> HTTP header for
5609 documents they assume you want to save locally before viewing them.
5610 The <quote>Content-Disposition:</quote> header contains the file name
5611 the browser is supposed to use by default.
5614 In most browsers that understand this header, it makes it impossible to
5615 <emphasis>just view</emphasis> the document, without downloading it first,
5616 even if it's just a simple text file or an image.
5619 Removing the <quote>Content-Disposition:</quote> header helps
5620 to prevent this annoyance, but some browsers additionally check the
5621 <quote>Content-Type:</quote> header, before they decide if they can
5622 display a document without saving it first. In these cases, you have
5623 to change this header as well, before the browser stops displaying
5627 It is also possible to change the server's file name suggestion
5628 to another one, but in most cases it isn't worth the time to set
5632 This action will probably be removed in the future,
5633 use server-header filters instead.
5639 <term>Example usage:</term>
5642 <screen># Disarm the download link in Sourceforge's patch tracker
5644 +content-type-overwrite{text/plain}\
5645 +hide-content-disposition{block} }
5646 .sourceforge.net/tracker/download\.php</screen>
5654 <!-- ~~~~~ New section ~~~~~ -->
5655 <sect3 renderas="sect4" id="hide-if-modified-since">
5656 <title>hide-if-modified-since</title>
5662 <term>Typical use:</term>
5664 <para>Prevent yet another way to track the user's steps between sessions.</para>
5669 <term>Effect:</term>
5672 Deletes the <quote>If-Modified-Since:</quote> HTTP client header or modifies its value.
5679 <!-- Boolean, Parameterized, Multi-value -->
5681 <para>Parameterized.</para>
5686 <term>Parameter:</term>
5689 Keyword: <quote>block</quote>, or a user defined value that specifies a range of hours.
5698 Removing this header is useful for filter testing, where you want to force a real
5699 reload instead of getting status code <quote>304</quote>, which would cause the
5700 browser to use a cached copy of the page.
5703 Instead of removing the header, <literal>hide-if-modified-since</literal> can
5704 also add or subtract a random amount of time to/from the header's value.
5705 You specify a range of minutes where the random factor should be chosen from and
5706 <application>Privoxy</application> does the rest. A negative value means
5707 subtracting, a positive value adding.
5710 Randomizing the value of the <quote>If-Modified-Since:</quote> makes
5711 it less likely that the server can use the time as a cookie replacement,
5712 but you will run into caching problems if the random range is too high.
5715 It is a good idea to only use a small negative value and let
5716 <literal><link linkend="overwrite-last-modified">overwrite-last-modified</link></literal>
5717 handle the greater changes.
5720 It is also recommended to use this action together with
5721 <literal><link linkend="crunch-if-none-match">crunch-if-none-match</link></literal>,
5722 otherwise it's more or less pointless.
5728 <term>Example usage (section):</term>
5731 <screen># Let the browser revalidate but make tracking based on the time less likely.
5732 {+hide-if-modified-since{-60} \
5733 +overwrite-last-modified{randomize} \
5734 +crunch-if-none-match}
5743 <!-- ~~~~~ New section ~~~~~ -->
5744 <sect3 renderas="sect4" id="hide-from-header">
5745 <title>hide-from-header</title>
5749 <term>Typical use:</term>
5751 <para>Keep your (old and ill) browser from telling web servers your email address</para>
5756 <term>Effect:</term>
5759 Deletes any existing <quote>From:</quote> HTTP header, or replaces it with the
5767 <!-- Boolean, Parameterized, Multi-value -->
5769 <para>Parameterized.</para>
5774 <term>Parameter:</term>
5777 Keyword: <quote>block</quote>, or any user defined value.
5786 The keyword <quote>block</quote> will completely remove the header
5787 (not to be confused with the <literal><link linkend="block">block</link></literal>
5791 Alternately, you can specify any value you prefer to be sent to the web
5792 server. If you do, it is a matter of fairness not to use any address that
5793 is actually used by a real person.
5796 This action is rarely needed, as modern web browsers don't send
5797 <quote>From:</quote> headers anymore.
5803 <term>Example usage:</term>
5806 <screen>+hide-from-header{block}</screen> or
5807 <screen>+hide-from-header{spam-me-senseless@sittingduck.example.com}</screen>
5815 <!-- ~~~~~ New section ~~~~~ -->
5816 <sect3 renderas="sect4" id="hide-referrer">
5817 <title>hide-referrer</title>
5818 <anchor id="hide-referer">
5821 <term>Typical use:</term>
5823 <para>Conceal which link you followed to get to a particular site</para>
5828 <term>Effect:</term>
5831 Deletes the <quote>Referer:</quote> (sic) HTTP header from the client request,
5832 or replaces it with a forged one.
5839 <!-- Boolean, Parameterized, Multi-value -->
5841 <para>Parameterized.</para>
5846 <term>Parameter:</term>
5850 <para><quote>conditional-block</quote> to delete the header completely if the host has changed.</para>
5853 <para><quote>conditional-forge</quote> to forge the header if the host has changed.</para>
5856 <para><quote>block</quote> to delete the header unconditionally.</para>
5859 <para><quote>forge</quote> to pretend to be coming from the homepage of the server we are talking to.</para>
5862 <para>Any other string to set a user defined referrer.</para>
5872 <literal>conditional-block</literal> is the only parameter,
5873 that isn't easily detected in the server's log file. If it blocks the
5874 referrer, the request will look like the visitor used a bookmark or
5875 typed in the address directly.
5878 Leaving the referrer unmodified for requests on the same host
5879 allows the server owner to see the visitor's <quote>click path</quote>,
5880 but in most cases she could also get that information by comparing
5881 other parts of the log file: for example the User-Agent if it isn't
5882 a very common one, or the user's IP address if it doesn't change between
5886 Always blocking the referrer, or using a custom one, can lead to
5887 failures on servers that check the referrer before they answer any
5888 requests, in an attempt to prevent their content from being
5889 embedded or linked to elsewhere.
5892 Both <literal>conditional-block</literal> and <literal>forge</literal>
5893 will work with referrer checks, as long as content and valid referring page
5894 are on the same host. Most of the time that's the case.
5897 <literal>hide-referer</literal> is an alternate spelling of
5898 <literal>hide-referrer</literal> and the two can be can be freely
5899 substituted with each other. (<quote>referrer</quote> is the
5900 correct English spelling, however the HTTP specification has a bug - it
5901 requires it to be spelled as <quote>referer</quote>.)
5907 <term>Example usage:</term>
5910 <screen>+hide-referrer{forge}</screen> or
5911 <screen>+hide-referrer{http://www.yahoo.com/}</screen>
5919 <!-- ~~~~~ New section ~~~~~ -->
5920 <sect3 renderas="sect4" id="hide-user-agent">
5921 <title>hide-user-agent</title>
5925 <term>Typical use:</term>
5927 <para>Try to conceal your type of browser and client operating system</para>
5932 <term>Effect:</term>
5935 Replaces the value of the <quote>User-Agent:</quote> HTTP header
5936 in client requests with the specified value.
5943 <!-- Boolean, Parameterized, Multi-value -->
5945 <para>Parameterized.</para>
5950 <term>Parameter:</term>
5953 Any user-defined string.
5963 This can lead to problems on web sites that depend on looking at this header in
5964 order to customize their content for different browsers (which, by the
5965 way, is <emphasis>NOT</emphasis> the right thing to do: good web sites
5966 work browser-independently).
5970 Using this action in multi-user setups or wherever different types of
5971 browsers will access the same <application>Privoxy</application> is
5972 <emphasis>not recommended</emphasis>. In single-user, single-browser
5973 setups, you might use it to delete your OS version information from
5974 the headers, because it is an invitation to exploit known bugs for your
5975 OS. It is also occasionally useful to forge this in order to access
5976 sites that won't let you in otherwise (though there may be a good
5977 reason in some cases).
5980 More information on known user-agent strings can be found at
5981 <ulink url="http://www.user-agents.org/">http://www.user-agents.org/</ulink>
5983 <ulink url="http://en.wikipedia.org/wiki/User_agent">http://en.wikipedia.org/wiki/User_agent</ulink>.
5989 <term>Example usage:</term>
5992 <screen>+hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}</screen>
6000 <!-- ~~~~~ New section ~~~~~ -->
6001 <sect3 renderas="sect4" id="limit-connect">
6002 <title>limit-connect</title>
6006 <term>Typical use:</term>
6008 <para>Prevent abuse of <application>Privoxy</application> as a TCP proxy relay or disable SSL for untrusted sites</para>
6013 <term>Effect:</term>
6016 Specifies to which ports HTTP CONNECT requests are allowable.
6023 <!-- Boolean, Parameterized, Multi-value -->
6025 <para>Parameterized.</para>
6030 <term>Parameter:</term>
6033 A comma-separated list of ports or port ranges (the latter using dashes, with the minimum
6034 defaulting to 0 and the maximum to 65K).
6043 By default, i.e. if no <literal>limit-connect</literal> action applies,
6044 <application>Privoxy</application> allows HTTP CONNECT requests to all
6045 ports. Use <literal>limit-connect</literal> if fine-grained control
6046 is desired for some or all destinations.
6049 The CONNECT methods exists in HTTP to allow access to secure websites
6050 (<quote>https://</quote> URLs) through proxies. It works very simply:
6051 the proxy connects to the server on the specified port, and then
6052 short-circuits its connections to the client and to the remote server.
6053 This means CONNECT-enabled proxies can be used as TCP relays very easily.
6056 <application>Privoxy</application> relays HTTPS traffic without seeing
6057 the decoded content. Websites can leverage this limitation to circumvent &my-app;'s
6058 filters. By specifying an invalid port range you can disable HTTPS entirely.
6064 <term>Example usages:</term>
6066 <!-- I had trouble getting the spacing to look right in my browser -->
6067 <!-- I probably have the wrong font setup, bollocks. -->
6068 <!-- Apparently the emphasis tag uses a proportional font no matter what -->
6070 <screen>+limit-connect{443} # Port 443 is OK.
6071 +limit-connect{80,443} # Ports 80 and 443 are OK.
6072 +limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
6073 +limit-connect{-} # All ports are OK
6074 +limit-connect{,} # No HTTPS/SSL traffic is allowed</screen>
6082 <!-- ~~~~~ New section ~~~~~ -->
6083 <sect3 renderas="sect4" id="limit-cookie-lifetime">
6084 <title>limit-cookie-lifetime</title>
6088 <term>Typical use:</term>
6090 <para>Limit the lifetime of HTTP cookies to a couple of minutes or hours.</para>
6095 <term>Effect:</term>
6098 Overwrites the expires field in Set-Cookie server headers if it's above the specified limit.
6105 <!-- Boolean, Parameterized, Multi-value -->
6107 <para>Parameterized.</para>
6112 <term>Parameter:</term>
6115 The lifetime limit in minutes, or 0.
6124 This action reduces the lifetime of HTTP cookies coming from the
6125 server to the specified number of minutes, starting from the time
6126 the cookie passes Privoxy.
6129 Cookies with a lifetime below the limit are not modified.
6130 The lifetime of session cookies is set to the specified limit.
6133 The effect of this action depends on the server.
6136 In case of servers which refresh their cookies with each response
6137 (or at least frequently), the lifetime limit set by this action
6139 Thus, a session associated with the cookie continues to work with
6140 this action enabled, as long as a new request is made before the
6141 last limit set is reached.
6144 However, some servers send their cookies once, with a lifetime of several
6145 years (the year 2037 is a popular choice), and do not refresh them
6146 until a certain event in the future, for example the user logging out.
6147 In this case this action may limit the absolute lifetime of the session,
6148 even if requests are made frequently.
6151 If the parameter is <quote>0</quote>, this action behaves like
6152 <literal><link linkend="session-cookies-only">session-cookies-only</link></literal>.
6158 <term>Example usages:</term>
6161 <screen>+limit-cookie-lifetime{60}
6169 <!-- ~~~~~ New section ~~~~~ -->
6170 <sect3 renderas="sect4" id="prevent-compression">
6171 <title>prevent-compression</title>
6175 <term>Typical use:</term>
6178 Ensure that servers send the content uncompressed, so it can be
6179 passed through <literal><link linkend="filter">filter</link></literal>s.
6185 <term>Effect:</term>
6188 Removes the Accept-Encoding header which can be used to ask for compressed transfer.
6195 <!-- Boolean, Parameterized, Multi-value -->
6197 <para>Boolean.</para>
6202 <term>Parameter:</term>
6214 More and more websites send their content compressed by default, which
6215 is generally a good idea and saves bandwidth. But the <literal><link
6216 linkend="filter">filter</link></literal> and
6217 <literal><link linkend="deanimate-gifs">deanimate-gifs</link></literal>
6218 actions need access to the uncompressed data.
6221 When compiled with zlib support (available since &my-app; 3.0.7), content that should be
6222 filtered is decompressed on-the-fly and you don't have to worry about this action.
6223 If you are using an older &my-app; version, or one that hasn't been compiled with zlib
6224 support, this action can be used to convince the server to send the content uncompressed.
6227 Most text-based instances compress very well, the size is seldom decreased by less than 50%,
6228 for markup-heavy instances like news feeds saving more than 90% of the original size isn't
6232 Not using compression will therefore slow down the transfer, and you should only
6233 enable this action if you really need it. As of &my-app; 3.0.7 it's disabled in all
6234 predefined action settings.
6237 Note that some (rare) ill-configured sites don't handle requests for uncompressed
6238 documents correctly. Broken PHP applications tend to send an empty document body,
6239 some IIS versions only send the beginning of the content. If you enable
6240 <literal>prevent-compression</literal> per default, you might want to add
6241 exceptions for those sites. See the example for how to do that.
6247 <term>Example usage (sections):</term>
6251 # Selectively turn off compression, and enable a filter
6253 { +filter{tiny-textforms} +prevent-compression }
6254 # Match only these sites
6259 # Or instead, we could set a universal default:
6261 { +prevent-compression }
6264 # Then maybe make exceptions for broken sites:
6266 { -prevent-compression }
6267 .compusa.com/</screen>
6276 <!-- ~~~~~ New section ~~~~~ -->
6277 <sect3 renderas="sect4" id="overwrite-last-modified">
6278 <title>overwrite-last-modified</title>
6284 <term>Typical use:</term>
6286 <para>Prevent yet another way to track the user's steps between sessions.</para>
6291 <term>Effect:</term>
6294 Deletes the <quote>Last-Modified:</quote> HTTP server header or modifies its value.
6301 <!-- Boolean, Parameterized, Multi-value -->
6303 <para>Parameterized.</para>
6308 <term>Parameter:</term>
6311 One of the keywords: <quote>block</quote>, <quote>reset-to-request-time</quote>
6312 and <quote>randomize</quote>
6321 Removing the <quote>Last-Modified:</quote> header is useful for filter
6322 testing, where you want to force a real reload instead of getting status
6323 code <quote>304</quote>, which would cause the browser to reuse the old
6324 version of the page.
6327 The <quote>randomize</quote> option overwrites the value of the
6328 <quote>Last-Modified:</quote> header with a randomly chosen time
6329 between the original value and the current time. In theory the server
6330 could send each document with a different <quote>Last-Modified:</quote>
6331 header to track visits without using cookies. <quote>Randomize</quote>
6332 makes it impossible and the browser can still revalidate cached documents.
6335 <quote>reset-to-request-time</quote> overwrites the value of the
6336 <quote>Last-Modified:</quote> header with the current time. You could use
6337 this option together with
6338 <literal><link linkend="hide-if-modified-since">hide-if-modified-since</link></literal>
6339 to further customize your random range.
6342 The preferred parameter here is <quote>randomize</quote>. It is safe
6343 to use, as long as the time settings are more or less correct.
6344 If the server sets the <quote>Last-Modified:</quote> header to the time
6345 of the request, the random range becomes zero and the value stays the same.
6346 Therefore you should later randomize it a second time with
6347 <literal><link linkend="hide-if-modified-since">hided-if-modified-since</link></literal>,
6351 It is also recommended to use this action together with
6352 <literal><link linkend="crunch-if-none-match">crunch-if-none-match</link></literal>.
6358 <term>Example usage:</term>
6361 <screen># Let the browser revalidate without being tracked across sessions
6362 { +hide-if-modified-since{-60} \
6363 +overwrite-last-modified{randomize} \
6364 +crunch-if-none-match}
6373 <!-- ~~~~~ New section ~~~~~ -->
6374 <sect3 renderas="sect4" id="redirect">
6375 <title>redirect</title>
6381 <term>Typical use:</term>
6384 Redirect requests to other sites.
6390 <term>Effect:</term>
6393 Convinces the browser that the requested document has been moved
6394 to another location and the browser should get it from there.
6401 <!-- Boolean, Parameterized, Multi-value -->
6403 <para>Parameterized</para>
6408 <term>Parameter:</term>
6411 An absolute URL or a single pcrs command.
6420 Requests to which this action applies are answered with a
6421 HTTP redirect to URLs of your choosing. The new URL is
6422 either provided as parameter, or derived by applying a
6423 single pcrs command to the original URL.
6426 The syntax for pcrs commands is documented in the
6427 <link linkend="filter-file">filter file</link> section.
6430 This action will be ignored if you use it together with
6431 <literal><link linkend="block">block</link></literal>.
6432 It can be combined with
6433 <literal><link linkend="fast-redirects">fast-redirects{check-decoded-url}</link></literal>
6434 to redirect to a decoded version of a rewritten URL.
6437 Use this action carefully, make sure not to create redirection loops
6438 and be aware that using your own redirects might make it
6439 possible to fingerprint your requests.
6442 In case of problems with your redirects, or simply to watch
6443 them working, enable <link linkend="DEBUG">debug 128</link>.
6449 <term>Example usages:</term>
6452 <screen># Replace example.com's style sheet with another one
6453 { +redirect{http://localhost/css-replacements/example.com.css} }
6454 example.com/stylesheet\.css
6456 # Create a short, easy to remember nickname for a favorite site
6457 # (relies on the browser accept and forward invalid URLs to &my-app;)
6458 { +redirect{http://www.privoxy.org/user-manual/actions-file.html} }
6461 # Always use the expanded view for Undeadly.org articles
6462 # (Note the $ at the end of the URL pattern to make sure
6463 # the request for the rewritten URL isn't redirected as well)
6464 {+redirect{s@$@&mode=expanded@}}
6465 undeadly.org/cgi\?action=article&sid=\d*$
6467 # Redirect Google search requests to MSN
6468 {+redirect{s@^http://[^/]*/search\?q=([^&]*).*@http://search.msn.com/results.aspx?q=$1@}}
6471 # Redirect MSN search requests to Yahoo
6472 {+redirect{s@^http://[^/]*/results\.aspx\?q=([^&]*).*@http://search.yahoo.com/search?p=$1@}}
6473 search.msn.com//results\.aspx\?q=
6475 # Redirect remote requests for this manual
6476 # to the local version delivered by Privoxy
6477 {+redirect{s@^http://www@http://config@}}
6478 www.privoxy.org/user-manual/</screen>
6487 <!-- ~~~~~ New section ~~~~~ -->
6488 <sect3 renderas="sect4" id="server-header-filter">
6489 <title>server-header-filter</title>
6493 <term>Typical use:</term>
6496 Rewrite or remove single server headers.
6502 <term>Effect:</term>
6505 All server headers to which this action applies are filtered on-the-fly
6506 through the specified regular expression based substitutions.
6513 <!-- boolean, parameterized, Multi-value -->
6515 <para>Parameterized.</para>
6520 <term>Parameter:</term>
6523 The name of a server-header filter, as defined in one of the
6524 <link linkend="filter-file">filter files</link>.
6533 Server-header filters are applied to each header on its own, not to
6534 all at once. This makes it easier to diagnose problems, but on the downside
6535 you can't write filters that only change header x if header y's value is z.
6536 You can do that by using tags though.
6539 Server-header filters are executed after the other header actions have finished
6540 and use their output as input.
6543 Please refer to the <link linkend="filter-file">filter file chapter</link>
6544 to learn which server-header filters are available by default, and how to
6551 <term>Example usage (section):</term>
6555 {+server-header-filter{html-to-xml}}
6556 example.org/xml-instance-that-is-delivered-as-html
6558 {+server-header-filter{xml-to-html}}
6559 example.org/instance-that-is-delivered-as-xml-but-is-not
6569 <!-- ~~~~~ New section ~~~~~ -->
6570 <sect3 renderas="sect4" id="server-header-tagger">
6571 <title>server-header-tagger</title>
6575 <term>Typical use:</term>
6578 Enable or disable filters based on the Content-Type header.
6584 <term>Effect:</term>
6587 Server headers to which this action applies are filtered on-the-fly through
6588 the specified regular expression based substitutions, the result is used as
6596 <!-- boolean, parameterized, Multi-value -->
6598 <para>Parameterized.</para>
6603 <term>Parameter:</term>
6606 The name of a server-header tagger, as defined in one of the
6607 <link linkend="filter-file">filter files</link>.
6616 Server-header taggers are applied to each header on its own,
6617 and as the header isn't modified, each tagger <quote>sees</quote>
6621 Server-header taggers are executed before all other header actions
6622 that modify server headers. Their tags can be used to control
6623 all of the other server-header actions, the content filters
6624 and the crunch actions (<link linkend="redirect">redirect</link>
6625 and <link linkend="block">block</link>).
6628 Obviously crunching based on tags created by server-header taggers
6629 doesn't prevent the request from showing up in the server's log file.
6636 <term>Example usage (section):</term>
6640 # Tag every request with the content type declared by the server
6641 {+server-header-tagger{content-type}}
6652 <!-- ~~~~~ New section ~~~~~ -->
6653 <sect3 renderas="sect4" id="session-cookies-only">
6654 <title>session-cookies-only</title>
6658 <term>Typical use:</term>
6661 Allow only temporary <quote>session</quote> cookies (for the current
6662 browser session <emphasis>only</emphasis>).
6668 <term>Effect:</term>
6671 Deletes the <quote>expires</quote> field from <quote>Set-Cookie:</quote>
6672 server headers. Most browsers will not store such cookies permanently and
6673 forget them in between sessions.
6680 <!-- Boolean, Parameterized, Multi-value -->
6682 <para>Boolean.</para>
6687 <term>Parameter:</term>
6699 This is less strict than <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal> /
6700 <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal> and allows you to browse
6701 websites that insist or rely on setting cookies, without compromising your privacy too badly.
6704 Most browsers will not permanently store cookies that have been processed by
6705 <literal>session-cookies-only</literal> and will forget about them between sessions.
6706 This makes profiling cookies useless, but won't break sites which require cookies so
6707 that you can log in for transactions. This is generally turned on for all
6708 sites, and is the recommended setting.
6711 It makes <emphasis>no sense at all</emphasis> to use <literal>session-cookies-only</literal>
6712 together with <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal> or
6713 <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal>. If you do, cookies
6714 will be plainly killed.
6717 Note that it is up to the browser how it handles such cookies without an <quote>expires</quote>
6718 field. If you use an exotic browser, you might want to try it out to be sure.
6721 This setting also has no effect on cookies that may have been stored
6722 previously by the browser before starting <application>Privoxy</application>.
6723 These would have to be removed manually.
6726 <application>Privoxy</application> also uses
6727 the <link linkend="filter-content-cookies">content-cookies filter</link>
6728 to block some types of cookies. Content cookies are not effected by
6729 <literal>session-cookies-only</literal>.
6735 <term>Example usage:</term>
6738 <screen>+session-cookies-only</screen>
6746 <!-- ~~~~~ New section ~~~~~ -->
6747 <sect3 renderas="sect4" id="set-image-blocker">
6748 <title>set-image-blocker</title>
6752 <term>Typical use:</term>
6754 <para>Choose the replacement for blocked images</para>
6759 <term>Effect:</term>
6762 This action alone doesn't do anything noticeable. If <emphasis>both</emphasis>
6763 <literal><link linkend="block">block</link></literal> <emphasis>and</emphasis> <literal><link
6764 linkend="handle-as-image">handle-as-image</link></literal> <emphasis>also</emphasis>
6765 apply, i.e. if the request is to be blocked as an image,
6766 <emphasis>then</emphasis> the parameter of this action decides what will be
6767 sent as a replacement.
6774 <!-- Boolean, Parameterized, Multi-value -->
6776 <para>Parameterized.</para>
6781 <term>Parameter:</term>
6786 <quote>pattern</quote> to send a built-in checkerboard pattern image. The image is visually
6787 decent, scales very well, and makes it obvious where banners were busted.
6792 <quote>blank</quote> to send a built-in transparent image. This makes banners disappear
6793 completely, but makes it hard to detect where <application>Privoxy</application> has blocked
6794 images on a given page and complicates troubleshooting if <application>Privoxy</application>
6795 has blocked innocent images, like navigation icons.
6800 <quote><replaceable class="parameter">target-url</replaceable></quote> to
6801 send a redirect to <replaceable class="parameter">target-url</replaceable>. You can redirect
6802 to any image anywhere, even in your local filesystem via <quote>file:///</quote> URL.
6803 (But note that not all browsers support redirecting to a local file system).
6806 A good application of redirects is to use special <application>Privoxy</application>-built-in
6807 URLs, which send the built-in images, as <replaceable class="parameter">target-url</replaceable>.
6808 This has the same visual effect as specifying <quote>blank</quote> or <quote>pattern</quote> in
6809 the first place, but enables your browser to cache the replacement image, instead of requesting
6810 it over and over again.
6821 The URLs for the built-in images are <quote>http://config.privoxy.org/send-banner?type=<replaceable
6822 class="parameter">type</replaceable></quote>, where <replaceable class="parameter">type</replaceable> is
6823 either <quote>blank</quote> or <quote>pattern</quote>.
6826 There is a third (advanced) type, called <quote>auto</quote>. It is <emphasis>NOT</emphasis> to be
6827 used in <literal>set-image-blocker</literal>, but meant for use from <link linkend="filter-file">filters</link>.
6828 Auto will select the type of image that would have applied to the referring page, had it been an image.
6834 <term>Example usage:</term>
6840 <screen>+set-image-blocker{pattern}</screen>
6843 Redirect to the BSD daemon:
6846 <screen>+set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}</screen>
6849 Redirect to the built-in pattern for better caching:
6852 <screen>+set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}</screen>
6860 <!-- ~~~~~ New section ~~~~~ -->
6862 <title>Summary</title>
6864 Note that many of these actions have the potential to cause a page to
6865 misbehave, possibly even not to display at all. There are many ways
6866 a site designer may choose to design his site, and what HTTP header
6867 content, and other criteria, he may depend on. There is no way to have hard
6868 and fast rules for all sites. See the <link
6869 linkend="ACTIONSANAT">Appendix</link> for a brief example on troubleshooting
6875 <!-- ~~~~~ New section ~~~~~ -->
6876 <sect2 id="aliases">
6877 <title>Aliases</title>
6879 Custom <quote>actions</quote>, known to <application>Privoxy</application>
6880 as <quote>aliases</quote>, can be defined by combining other actions.
6881 These can in turn be invoked just like the built-in actions.
6882 Currently, an alias name can contain any character except space, tab,
6884 <quote>{</quote> and <quote>}</quote>, but we <emphasis>strongly
6885 recommend</emphasis> that you only use <quote>a</quote> to <quote>z</quote>,
6886 <quote>0</quote> to <quote>9</quote>, <quote>+</quote>, and <quote>-</quote>.
6887 Alias names are not case sensitive, and are not required to start with a
6888 <quote>+</quote> or <quote>-</quote> sign, since they are merely textually
6892 Aliases can be used throughout the actions file, but they <emphasis>must be
6893 defined in a special section at the top of the file!</emphasis>
6894 And there can only be one such section per actions file. Each actions file may
6895 have its own alias section, and the aliases defined in it are only visible
6899 There are two main reasons to use aliases: One is to save typing for frequently
6900 used combinations of actions, the other one is a gain in flexibility: If you
6901 decide once how you want to handle shops by defining an alias called
6902 <quote>shop</quote>, you can later change your policy on shops in
6903 <emphasis>one</emphasis> place, and your changes will take effect everywhere
6904 in the actions file where the <quote>shop</quote> alias is used. Calling aliases
6905 by their purpose also makes your actions files more readable.
6908 Currently, there is one big drawback to using aliases, though:
6909 <application>Privoxy</application>'s built-in web-based action file
6910 editor honors aliases when reading the actions files, but it expands
6911 them before writing. So the effects of your aliases are of course preserved,
6912 but the aliases themselves are lost when you edit sections that use aliases
6917 Now let's define some aliases...
6922 # Useful custom aliases we can use later.
6924 # Note the (required!) section header line and that this section
6925 # must be at the top of the actions file!
6929 # These aliases just save typing later:
6930 # (Note that some already use other aliases!)
6932 +crunch-all-cookies = +<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> +<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
6933 -crunch-all-cookies = -<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> -<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
6934 +block-as-image = +block{Blocked image.} +handle-as-image
6935 allow-all-cookies = -crunch-all-cookies -<link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> -<link linkend="FILTER-CONTENT-COOKIES">filter{content-cookies}</link>
6937 # These aliases define combinations of actions
6938 # that are useful for certain types of sites:
6940 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>
6942 shop = -crunch-all-cookies -<link linkend="FILTER-ALL-POPUPS">filter{all-popups}</link>
6944 # Short names for other aliases, for really lazy people ;-)
6946 c0 = +crunch-all-cookies
6947 c1 = -crunch-all-cookies</screen>
6951 ...and put them to use. These sections would appear in the lower part of an
6952 actions file and define exceptions to the default actions (as specified further
6953 up for the <quote>/</quote> pattern):
6958 # These sites are either very complex or very keen on
6959 # user data and require minimal interference to work:
6962 .office.microsoft.com
6963 .windowsupdate.microsoft.com
6964 # Gmail is really mail.google.com, not gmail.com
6968 # Allow cookies (for setting and retrieving your customer data)
6972 .worldpay.com # for quietpc.com
6975 # These shops require pop-ups:
6977 {-filter{all-popups} -filter{unsolicited-popups}}
6979 .overclockers.co.uk</screen>
6983 Aliases like <quote>shop</quote> and <quote>fragile</quote> are typically used for
6984 <quote>problem</quote> sites that require more than one action to be disabled
6985 in order to function properly.
6991 <!-- ~~~~~ New section ~~~~~ -->
6992 <sect2 id="act-examples">
6993 <title>Actions Files Tutorial</title>
6995 The above chapters have shown <link linkend="actions-file">which actions files
6996 there are and how they are organized</link>, how actions are <link
6997 linkend="actions">specified</link> and <link linkend="actions-apply">applied
6998 to URLs</link>, how <link linkend="af-patterns">patterns</link> work, and how to
6999 define and use <link linkend="aliases">aliases</link>. Now, let's look at an
7000 example <filename>match-all.action</filename>, <filename>default.action</filename>
7001 and <filename>user.action</filename> file and see how all these pieces come together:
7005 <title>match-all.action</title>
7007 Remember <emphasis>all actions are disabled when matching starts</emphasis>,
7008 so we have to explicitly enable the ones we want.
7012 While the <filename>match-all.action</filename> file only contains a
7013 single section, it is probably the most important one. It has only one
7014 pattern, <quote><literal>/</literal></quote>, but this pattern
7015 <link linkend="af-patterns">matches all URLs</link>. Therefore, the set of
7016 actions used in this <quote>default</quote> section <emphasis>will
7017 be applied to all requests as a start</emphasis>. It can be partly or
7018 wholly overridden by other actions files like <filename>default.action</filename>
7019 and <filename>user.action</filename>, but it will still be largely responsible
7020 for your overall browsing experience.
7024 Again, at the start of matching, all actions are disabled, so there is
7025 no need to disable any actions here. (Remember: a <quote>+</quote>
7026 preceding the action name enables the action, a <quote>-</quote> disables!).
7027 Also note how this long line has been made more readable by splitting it into
7028 multiple lines with line continuation.
7034 +<link linkend="CHANGE-X-FORWARDED-FOR">change-x-forwarded-for{block}</link> \
7035 +<link linkend="HIDE-FROM-HEADER">hide-from-header{block}</link> \
7036 +<link linkend="SET-IMAGE-BLOCKER">set-image-blocker{pattern}</link> \
7043 The default behavior is now set.
7048 <title>default.action</title>
7051 If you aren't a developer, there's no need for you to edit the
7052 <filename>default.action</filename> file. It is maintained by
7053 the &my-app; developers and if you disagree with some of the
7054 sections, you should overrule them in your <filename>user.action</filename>.
7058 Understanding the <filename>default.action</filename> file can
7059 help you with your <filename>user.action</filename>, though.
7063 The first section in this file is a special section for internal use
7064 that prevents older &my-app; versions from reading the file:
7069 ##########################################################################
7070 # Settings -- Don't change! For internal Privoxy use ONLY.
7071 ##########################################################################
7073 for-privoxy-version=3.0.11</screen>
7077 After that comes the (optional) alias section. We'll use the example
7078 section from the above <link linkend="aliases">chapter on aliases</link>,
7079 that also explains why and how aliases are used:
7084 ##########################################################################
7086 ##########################################################################
7089 # These aliases just save typing later:
7090 # (Note that some already use other aliases!)
7092 +crunch-all-cookies = +<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> +<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
7093 -crunch-all-cookies = -<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> -<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
7094 +block-as-image = +block{Blocked image.} +handle-as-image
7095 mercy-for-cookies = -crunch-all-cookies -<link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> -<link linkend="FILTER-CONTENT-COOKIES">filter{content-cookies}</link>
7097 # These aliases define combinations of actions
7098 # that are useful for certain types of sites:
7100 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>
7101 shop = -crunch-all-cookies -<link linkend="FILTER-ALL-POPUPS">filter{all-popups}</link></screen>
7105 The first of our specialized sections is concerned with <quote>fragile</quote>
7106 sites, i.e. sites that require minimum interference, because they are either
7107 very complex or very keen on tracking you (and have mechanisms in place that
7108 make them unusable for people who avoid being tracked). We will simply use
7109 our pre-defined <literal>fragile</literal> alias instead of stating the list
7110 of actions explicitly:
7115 ##########################################################################
7116 # Exceptions for sites that'll break under the default action set:
7117 ##########################################################################
7119 # "Fragile" Use a minimum set of actions for these sites (see alias above):
7122 .office.microsoft.com # surprise, surprise!
7123 .windowsupdate.microsoft.com
7124 mail.google.com</screen>
7128 Shopping sites are not as fragile, but they typically
7129 require cookies to log in, and pop-up windows for shopping
7130 carts or item details. Again, we'll use a pre-defined alias:
7139 .worldpay.com # for quietpc.com
7141 .scan.co.uk</screen>
7145 The <literal><link linkend="FAST-REDIRECTS">fast-redirects</link></literal>
7146 action, which may have been enabled in <filename>match-all.action</filename>,
7147 breaks some sites. So disable it for popular sites where we know it misbehaves:
7152 { -<link linkend="FAST-REDIRECTS">fast-redirects</link> }
7156 .altavista.com/.*(like|url|link):http
7157 .altavista.com/trans.*urltext=http
7158 .nytimes.com</screen>
7162 It is important that <application>Privoxy</application> knows which
7163 URLs belong to images, so that <emphasis>if</emphasis> they are to
7164 be blocked, a substitute image can be sent, rather than an HTML page.
7165 Contacting the remote site to find out is not an option, since it
7166 would destroy the loading time advantage of banner blocking, and it
7167 would feed the advertisers information about you. We can mark any
7168 URL as an image with the <literal><link
7169 linkend="handle-as-image">handle-as-image</link></literal> action,
7170 and marking all URLs that end in a known image file extension is a
7176 ##########################################################################
7178 ##########################################################################
7180 # Define which file types will be treated as images, in case they get
7181 # blocked further down this file:
7183 { +<link linkend="HANDLE-AS-IMAGE">handle-as-image</link> }
7184 /.*\.(gif|jpe?g|png|bmp|ico)$</screen>
7188 And then there are known banner sources. They often use scripts to
7189 generate the banners, so it won't be visible from the URL that the
7190 request is for an image. Hence we block them <emphasis>and</emphasis>
7191 mark them as images in one go, with the help of our
7192 <literal>+block-as-image</literal> alias defined above. (We could of
7193 course just as well use <literal>+<link linkend="block">block</link>
7194 +<link linkend="handle-as-image">handle-as-image</link></literal> here.)
7195 Remember that the type of the replacement image is chosen by the
7196 <literal><link linkend="set-image-blocker">set-image-blocker</link></literal>
7197 action. Since all URLs have matched the default section with its
7198 <literal>+<link linkend="set-image-blocker">set-image-blocker</link>{pattern}</literal>
7199 action before, it still applies and needn't be repeated:
7204 # Known ad generators:
7209 .ad.*.doubleclick.net
7210 .a.yimg.com/(?:(?!/i/).)*$
7211 .a[0-9].yimg.com/(?:(?!/i/).)*$
7217 One of the most important jobs of <application>Privoxy</application>
7218 is to block banners. Many of these can be <quote>blocked</quote>
7219 by the <literal><link linkend="filter">filter</link>{banners-by-size}</literal>
7220 action, which we enabled above, and which deletes the references to banner
7221 images from the pages while they are loaded, so the browser doesn't request
7222 them anymore, and hence they don't need to be blocked here. But this naturally
7223 doesn't catch all banners, and some people choose not to use filters, so we
7224 need a comprehensive list of patterns for banner URLs here, and apply the
7225 <literal><link linkend="block">block</link></literal> action to them.
7228 First comes many generic patterns, which do most of the work, by
7229 matching typical domain and path name components of banners. Then comes
7230 a list of individual patterns for specific sites, which is omitted here
7231 to keep the example short:
7236 ##########################################################################
7237 # Block these fine banners:
7238 ##########################################################################
7239 { <link linkend="BLOCK">+block{Banner ads.}</link> }
7247 /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
7248 /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
7250 # Site-specific patterns (abbreviated):
7252 .hitbox.com</screen>
7256 It's quite remarkable how many advertisers actually call their banner
7257 servers ads.<replaceable>company</replaceable>.com, or call the directory
7258 in which the banners are stored simply <quote>banners</quote>. So the above
7259 generic patterns are surprisingly effective.
7262 But being very generic, they necessarily also catch URLs that we don't want
7263 to block. The pattern <literal>.*ads.</literal> e.g. catches
7264 <quote>nasty-<emphasis>ads</emphasis>.nasty-corp.com</quote> as intended,
7265 but also <quote>downlo<emphasis>ads</emphasis>.sourcefroge.net</quote> or
7266 <quote><emphasis>ads</emphasis>l.some-provider.net.</quote> So here come some
7267 well-known exceptions to the <literal>+<link linkend="BLOCK">block</link></literal>
7271 Note that these are exceptions to exceptions from the default! Consider the URL
7272 <quote>downloads.sourcefroge.net</quote>: Initially, all actions are deactivated,
7273 so it wouldn't get blocked. Then comes the defaults section, which matches the
7274 URL, but just deactivates the <literal><link linkend="BLOCK">block</link></literal>
7275 action once again. Then it matches <literal>.*ads.</literal>, an exception to the
7276 general non-blocking policy, and suddenly
7277 <literal><link linkend="BLOCK">+block</link></literal> applies. And now, it'll match
7278 <literal>.*loads.</literal>, where <literal><link linkend="BLOCK">-block</link></literal>
7279 applies, so (unless it matches <emphasis>again</emphasis> further down) it ends up
7280 with no <literal><link linkend="BLOCK">block</link></literal> action applying.
7285 ##########################################################################
7286 # Save some innocent victims of the above generic block patterns:
7287 ##########################################################################
7291 { -<link linkend="BLOCK">block</link> }
7292 adv[io]*. # (for advogato.org and advice.*)
7293 adsl. # (has nothing to do with ads)
7294 adobe. # (has nothing to do with ads either)
7295 ad[ud]*. # (adult.* and add.*)
7296 .edu # (universities don't host banners (yet!))
7297 .*loads. # (downloads, uploads etc)
7305 www.globalintersec.com/adv # (adv = advanced)
7306 www.ugu.com/sui/ugu/adv</screen>
7310 Filtering source code can have nasty side effects,
7311 so make an exception for our friends at sourceforge.net,
7312 and all paths with <quote>cvs</quote> in them. Note that
7313 <literal>-<link linkend="FILTER">filter</link></literal>
7314 disables <emphasis>all</emphasis> filters in one fell swoop!
7319 # Don't filter code!
7321 { -<link linkend="FILTER">filter</link> }
7326 .sourceforge.net</screen>
7330 The actual <filename>default.action</filename> is of course much more
7331 comprehensive, but we hope this example made clear how it works.
7336 <sect3><title>user.action</title>
7339 So far we are painting with a broad brush by setting general policies,
7340 which would be a reasonable starting point for many people. Now,
7341 you might want to be more specific and have customized rules that
7342 are more suitable to your personal habits and preferences. These would
7343 be for narrowly defined situations like your ISP or your bank, and should
7344 be placed in <filename>user.action</filename>, which is parsed after all other
7345 actions files and hence has the last word, over-riding any previously
7346 defined actions. <filename>user.action</filename> is also a
7347 <emphasis>safe</emphasis> place for your personal settings, since
7348 <filename>default.action</filename> is actively maintained by the
7349 <application>Privoxy</application> developers and you'll probably want
7350 to install updated versions from time to time.
7354 So let's look at a few examples of things that one might typically do in
7355 <filename>user.action</filename>:
7359 <!-- brief sample user.action here -->
7363 # My user.action file. <fred@example.com></screen>
7367 As <link linkend="aliases">aliases</link> are local to the actions
7368 file that they are defined in, you can't use the ones from
7369 <filename>default.action</filename>, unless you repeat them here:
7374 # Aliases are local to the file they are defined in.
7375 # (Re-)define aliases for this file:
7379 # These aliases just save typing later, and the alias names should
7380 # be self explanatory.
7382 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
7383 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
7384 allow-all-cookies = -crunch-all-cookies -session-cookies-only
7385 allow-popups = -filter{all-popups}
7386 +block-as-image = +block{Blocked as image.} +handle-as-image
7387 -block-as-image = -block
7389 # These aliases define combinations of actions that are useful for
7390 # certain types of sites:
7392 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referrer
7393 shop = -crunch-all-cookies allow-popups
7395 # Allow ads for selected useful free sites:
7397 allow-ads = -block -filter{banners-by-size} -filter{banners-by-link}
7399 # Alias for specific file types that are text, but might have conflicting
7400 # MIME types. We want the browser to force these to be text documents.
7401 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>
7406 Say you have accounts on some sites that you visit regularly, and
7407 you don't want to have to log in manually each time. So you'd like
7408 to allow persistent cookies for these sites. The
7409 <literal>allow-all-cookies</literal> alias defined above does exactly
7410 that, i.e. it disables crunching of cookies in any direction, and the
7411 processing of cookies to make them only temporary.
7416 { allow-all-cookies }
7420 .redhat.com</screen>
7424 Your bank is allergic to some filter, but you don't know which, so you disable them all:
7429 { -<link linkend="FILTER">filter</link> }
7430 .your-home-banking-site.com</screen>
7434 Some file types you may not want to filter for various reasons:
7439 # Technical documentation is likely to contain strings that might
7440 # erroneously get altered by the JavaScript-oriented filters:
7445 # And this stupid host sends streaming video with a wrong MIME type,
7446 # so that Privoxy thinks it is getting HTML and starts filtering:
7448 stupid-server.example.com/</screen>
7452 Example of a simple <link linkend="BLOCK">block</link> action. Say you've
7453 seen an ad on your favourite page on example.com that you want to get rid of.
7454 You have right-clicked the image, selected <quote>copy image location</quote>
7455 and pasted the URL below while removing the leading http://, into a
7456 <literal>{ +block{} }</literal> section. Note that <literal>{ +handle-as-image
7457 }</literal> need not be specified, since all URLs ending in
7458 <literal>.gif</literal> will be tagged as images by the general rules as set
7459 in default.action anyway:
7464 { +<link linkend="BLOCK">block</link>{Nasty ads.} }
7465 www.example.com/nasty-ads/sponsor\.gif
7466 another.example.net/more/junk/here/</screen>
7470 The URLs of dynamically generated banners, especially from large banner
7471 farms, often don't use the well-known image file name extensions, which
7472 makes it impossible for <application>Privoxy</application> to guess
7473 the file type just by looking at the URL.
7474 You can use the <literal>+block-as-image</literal> alias defined above for
7476 Note that objects which match this rule but then turn out NOT to be an
7477 image are typically rendered as a <quote>broken image</quote> icon by the
7478 browser. Use cautiously.
7487 ar.atwola.com/</screen>
7491 Now you noticed that the default configuration breaks Forbes Magazine,
7492 but you were too lazy to find out which action is the culprit, and you
7493 were again too lazy to give <link linkend="contact">feedback</link>, so
7494 you just used the <literal>fragile</literal> alias on the site, and
7495 -- <emphasis>whoa!</emphasis> -- it worked. The <literal>fragile</literal>
7496 aliases disables those actions that are most likely to break a site. Also,
7497 good for testing purposes to see if it is <application>Privoxy</application>
7498 that is causing the problem or not. We later find other regular sites
7499 that misbehave, and add those to our personalized list of troublemakers:
7507 .mybank.com</screen>
7511 You like the <quote>fun</quote> text replacements in <filename>default.filter</filename>,
7512 but it is disabled in the distributed actions file.
7513 So you'd like to turn it on in your private,
7514 update-safe config, once and for all:
7519 { +<link linkend="filter-fun">filter{fun}</link> }
7520 / # For ALL sites!</screen>
7524 Note that the above is not really a good idea: There are exceptions
7525 to the filters in <filename>default.action</filename> for things that
7526 really shouldn't be filtered, like code on CVS->Web interfaces. Since
7527 <filename>user.action</filename> has the last word, these exceptions
7528 won't be valid for the <quote>fun</quote> filtering specified here.
7532 You might also worry about how your favourite free websites are
7533 funded, and find that they rely on displaying banner advertisements
7534 to survive. So you might want to specifically allow banners for those
7535 sites that you feel provide value to you:
7547 Note that <literal>allow-ads</literal> has been aliased to
7548 <literal>-<link linkend="block">block</link></literal>,
7549 <literal>-<link linkend="filter-banners-by-size">filter{banners-by-size}</link></literal>, and
7550 <literal>-<link linkend="filter-banners-by-link">filter{banners-by-link}</link></literal> above.
7554 Invoke another alias here to force an over-ride of the MIME type <literal>
7555 application/x-sh</literal> which typically would open a download type
7556 dialog. In my case, I want to look at the shell script, and then I can save
7557 it should I choose to.
7567 <filename>user.action</filename> is generally the best place to define
7568 exceptions and additions to the default policies of
7569 <filename>default.action</filename>. Some actions are safe to have their
7570 default policies set here though. So let's set a default policy to have a
7571 <quote>blank</quote> image as opposed to the checkerboard pattern for
7572 <emphasis>ALL</emphasis> sites. <quote>/</quote> of course matches all URL
7578 { +<link linkend="set-image-blocker">set-image-blocker{blank}</link> }
7579 / # ALL sites</screen>
7585 <!-- ~ End section ~ -->
7589 <!-- ~ End section ~ -->
7591 <!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
7593 <sect1 id="filter-file">
7594 <title>Filter Files</title>
7597 On-the-fly text substitutions need
7598 to be defined in a <quote>filter file</quote>. Once defined, they
7599 can then be invoked as an <quote>action</quote>.
7603 &my-app; supports three different filter actions:
7604 <literal><link linkend="filter">filter</link></literal> to
7605 rewrite the content that is send to the client,
7606 <literal><link linkend="client-header-filter">client-header-filter</link></literal>
7607 to rewrite headers that are send by the client, and
7608 <literal><link linkend="server-header-filter">server-header-filter</link></literal>
7609 to rewrite headers that are send by the server.
7613 &my-app; also supports two tagger actions:
7614 <literal><link linkend="client-header-tagger">client-header-tagger</link></literal>
7616 <literal><link linkend="server-header-tagger">server-header-tagger</link></literal>.
7617 Taggers and filters use the same syntax in the filter files, the difference
7618 is that taggers don't modify the text they are filtering, but use a rewritten
7619 version of the filtered text as tag. The tags can then be used to change the
7620 applying actions through sections with <link linkend="tag-pattern">tag-patterns</link>.
7625 Multiple filter files can be defined through the <literal> <link
7626 linkend="filterfile">filterfile</link></literal> config directive. The filters
7627 as supplied by the developers are located in
7628 <filename>default.filter</filename>. It is recommended that any locally
7629 defined or modified filters go in a separately defined file such as
7630 <filename>user.filter</filename>.
7634 Common tasks for content filters are to eliminate common annoyances in
7635 HTML and JavaScript, such as pop-up windows,
7636 exit consoles, crippled windows without navigation tools, the
7637 infamous <BLINK> tag etc, to suppress images with certain
7638 width and height attributes (standard banner sizes or web-bugs),
7639 or just to have fun.
7643 Enabled content filters are applied to any content whose
7644 <quote>Content Type</quote> header is recognised as a sign
7645 of text-based content, with the exception of <literal>text/plain</literal>.
7646 Use the <link linkend="FORCE-TEXT-MODE">force-text-mode</link> action
7647 to also filter other content.
7651 Substitutions are made at the source level, so if you want to <quote>roll
7652 your own</quote> filters, you should first be familiar with HTML syntax,
7653 and, of course, regular expressions.
7657 Just like the <link linkend="actions-file">actions files</link>, the
7658 filter file is organized in sections, which are called <emphasis>filters</emphasis>
7659 here. Each filter consists of a heading line, that starts with one of the
7660 <emphasis>keywords</emphasis> <literal>FILTER:</literal>,
7661 <literal>CLIENT-HEADER-FILTER:</literal> or <literal>SERVER-HEADER-FILTER:</literal>
7662 followed by the filter's <emphasis>name</emphasis>, and a short (one line)
7663 <emphasis>description</emphasis> of what it does. Below that line
7664 come the <emphasis>jobs</emphasis>, i.e. lines that define the actual
7665 text substitutions. By convention, the name of a filter
7666 should describe what the filter <emphasis>eliminates</emphasis>. The
7667 comment is used in the <ulink url="http://config.privoxy.org/">web-based
7668 user interface</ulink>.
7672 Once a filter called <replaceable>name</replaceable> has been defined
7673 in the filter file, it can be invoked by using an action of the form
7674 +<literal><link linkend="filter">filter</link>{<replaceable>name</replaceable>}</literal>
7675 in any <link linkend="actions-file">actions file</link>.
7679 Filter definitions start with a header line that contains the filter
7680 type, the filter name and the filter description.
7681 A content filter header line for a filter called <quote>foo</quote> could look
7686 <screen>FILTER: foo Replace all "foo" with "bar"</screen>
7690 Below that line, and up to the next header line, come the jobs that
7691 define what text replacements the filter executes. They are specified
7692 in a syntax that imitates <ulink url="http://www.perl.org/">Perl</ulink>'s
7693 <literal>s///</literal> operator. If you are familiar with Perl, you
7694 will find this to be quite intuitive, and may want to look at the
7695 PCRS documentation for the subtle differences to Perl behaviour. Most
7696 notably, the non-standard option letter <literal>U</literal> is supported,
7697 which turns the default to ungreedy matching.
7702 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
7703 Expressions</quote></ulink>, you might want to take a look at
7704 the <link linkend="regex">Appendix on regular expressions</link>, and
7705 see the <ulink url="http://perldoc.perl.org/perlre.html">Perl
7707 <ulink url="http://perldoc.perl.org/perlop.html">the
7708 <literal>s///</literal> operator's syntax</ulink> and <ulink
7709 url="http://perldoc.perl.org/perlre.html">Perl-style regular
7710 expressions</ulink> in general.
7711 The below examples might also help to get you started.
7715 <!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
7717 <sect2><title>Filter File Tutorial</title>
7719 Now, let's complete our <quote>foo</quote> content filter. We have already defined
7720 the heading, but the jobs are still missing. Since all it does is to replace
7721 <quote>foo</quote> with <quote>bar</quote>, there is only one (trivial) job
7726 <screen>s/foo/bar/</screen>
7730 But wait! Didn't the comment say that <emphasis>all</emphasis> occurrences
7731 of <quote>foo</quote> should be replaced? Our current job will only take
7732 care of the first <quote>foo</quote> on each page. For global substitution,
7733 we'll need to add the <literal>g</literal> option:
7737 <screen>s/foo/bar/g</screen>
7741 Our complete filter now looks like this:
7744 <screen>FILTER: foo Replace all "foo" with "bar"
7745 s/foo/bar/g</screen>
7749 Let's look at some real filters for more interesting examples. Here you see
7750 a filter that protects against some common annoyances that arise from JavaScript
7751 abuse. Let's look at its jobs one after the other:
7757 FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse
7759 # Get rid of JavaScript referrer tracking. Test page: http://www.randomoddness.com/untitled.htm
7761 s|(<script.*)document\.referrer(.*</script>)|$1"Not Your Business!"$2|Usg</screen>
7765 Following the header line and a comment, you see the job. Note that it uses
7766 <literal>|</literal> as the delimiter instead of <literal>/</literal>, because
7767 the pattern contains a forward slash, which would otherwise have to be escaped
7768 by a backslash (<literal>\</literal>).
7772 Now, let's examine the pattern: it starts with the text <literal><script.*</literal>
7773 enclosed in parentheses. Since the dot matches any character, and <literal>*</literal>
7774 means: <quote>Match an arbitrary number of the element left of myself</quote>, this
7775 matches <quote><script</quote>, followed by <emphasis>any</emphasis> text, i.e.
7776 it matches the whole page, from the start of the first <script> tag.
7780 That's more than we want, but the pattern continues: <literal>document\.referrer</literal>
7781 matches only the exact string <quote>document.referrer</quote>. The dot needed to
7782 be <emphasis>escaped</emphasis>, i.e. preceded by a backslash, to take away its
7783 special meaning as a joker, and make it just a regular dot. So far, the meaning is:
7784 Match from the start of the first <script> tag in a the page, up to, and including,
7785 the text <quote>document.referrer</quote>, if <emphasis>both</emphasis> are present
7786 in the page (and appear in that order).
7790 But there's still more pattern to go. The next element, again enclosed in parentheses,
7791 is <literal>.*</script></literal>. You already know what <literal>.*</literal>
7792 means, so the whole pattern translates to: Match from the start of the first <script>
7793 tag in a page to the end of the last <script> tag, provided that the text
7794 <quote>document.referrer</quote> appears somewhere in between.
7798 This is still not the whole story, since we have ignored the options and the parentheses:
7799 The portions of the page matched by sub-patterns that are enclosed in parentheses, will be
7800 remembered and be available through the variables <literal>$1, $2, ...</literal> in
7801 the substitute. The <literal>U</literal> option switches to ungreedy matching, which means
7802 that the first <literal>.*</literal> in the pattern will only <quote>eat up</quote> all
7803 text in between <quote><script</quote> and the <emphasis>first</emphasis> occurrence
7804 of <quote>document.referrer</quote>, and that the second <literal>.*</literal> will
7805 only span the text up to the <emphasis>first</emphasis> <quote></script></quote>
7806 tag. Furthermore, the <literal>s</literal> option says that the match may span
7807 multiple lines in the page, and the <literal>g</literal> option again means that the
7808 substitution is global.
7812 So, to summarize, the pattern means: Match all scripts that contain the text
7813 <quote>document.referrer</quote>. Remember the parts of the script from
7814 (and including) the start tag up to (and excluding) the string
7815 <quote>document.referrer</quote> as <literal>$1</literal>, and the part following
7816 that string, up to and including the closing tag, as <literal>$2</literal>.
7820 Now the pattern is deciphered, but wasn't this about substituting things? So
7821 lets look at the substitute: <literal>$1"Not Your Business!"$2</literal> is
7822 easy to read: The text remembered as <literal>$1</literal>, followed by
7823 <literal>"Not Your Business!"</literal> (<emphasis>including</emphasis>
7824 the quotation marks!), followed by the text remembered as <literal>$2</literal>.
7825 This produces an exact copy of the original string, with the middle part
7826 (the <quote>document.referrer</quote>) replaced by <literal>"Not Your
7827 Business!"</literal>.
7831 The whole job now reads: Replace <quote>document.referrer</quote> by
7832 <literal>"Not Your Business!"</literal> wherever it appears inside a
7833 <script> tag. Note that this job won't break JavaScript syntax,
7834 since both the original and the replacement are syntactically valid
7835 string objects. The script just won't have access to the referrer
7836 information anymore.
7840 We'll show you two other jobs from the JavaScript taming department, but
7841 this time only point out the constructs of special interest:
7846 # The status bar is for displaying link targets, not pointless blahblah
7848 s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig</screen>
7852 <literal>\s</literal> stands for whitespace characters (space, tab, newline,
7853 carriage return, form feed), so that <literal>\s*</literal> means: <quote>zero
7854 or more whitespace</quote>. The <literal>?</literal> in <literal>.*?</literal>
7855 makes this matching of arbitrary text ungreedy. (Note that the <literal>U</literal>
7856 option is not set). The <literal>['"]</literal> construct means: <quote>a single
7857 <emphasis>or</emphasis> a double quote</quote>. Finally, <literal>\1</literal> is
7858 a back-reference to the first parenthesis just like <literal>$1</literal> above,
7859 with the difference that in the <emphasis>pattern</emphasis>, a backslash indicates
7860 a back-reference, whereas in the <emphasis>substitute</emphasis>, it's the dollar.
7864 So what does this job do? It replaces assignments of single- or double-quoted
7865 strings to the <quote>window.status</quote> object with a dummy assignment
7866 (using a variable name that is hopefully odd enough not to conflict with
7867 real variables in scripts). Thus, it catches many cases where e.g. pointless
7868 descriptions are displayed in the status bar instead of the link target when
7869 you move your mouse over links.
7874 # Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html
7876 s/(<body [^>]*)onunload(.*>)/$1never$2/iU</screen>
7881 <ulink url="http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-htmlevents">OnUnload
7882 event binding</ulink> in the HTML DOM was a <emphasis>CRIME</emphasis>.
7883 When I close a browser window, I want it to close and die. Basta.
7884 This job replaces the <quote>onunload</quote> attribute in
7885 <quote><body></quote> tags with the dummy word <literal>never</literal>.
7886 Note that the <literal>i</literal> option makes the pattern matching
7887 case-insensitive. Also note that ungreedy matching alone doesn't always guarantee
7888 a minimal match: In the first parenthesis, we had to use <literal>[^>]*</literal>
7889 instead of <literal>.*</literal> to prevent the match from exceeding the
7890 <body> tag if it doesn't contain <quote>OnUnload</quote>, but the page's
7895 The last example is from the fun department:
7900 FILTER: fun Fun text replacements
7902 # Spice the daily news:
7904 s/microsoft(?!\.com)/MicroSuck/ig</screen>
7908 Note the <literal>(?!\.com)</literal> part (a so-called negative lookahead)
7909 in the job's pattern, which means: Don't match, if the string
7910 <quote>.com</quote> appears directly following <quote>microsoft</quote>
7911 in the page. This prevents links to microsoft.com from being trashed, while
7912 still replacing the word everywhere else.
7917 # Buzzword Bingo (example for extended regex syntax)
7919 s* industry[ -]leading \
7921 | customer[ -]focused \
7922 | market[ -]driven \
7923 | award[ -]winning # Comments are OK, too! \
7924 | high[ -]performance \
7925 | solutions[ -]based \
7929 *<font color="red"><b>BINGO!</b></font> \
7934 The <literal>x</literal> option in this job turns on extended syntax, and allows for
7935 e.g. the liberal use of (non-interpreted!) whitespace for nicer formatting.
7943 <!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
7945 <sect2 id="predefined-filters"><title>The Pre-defined Filters</title>
7949 Note each filter is also listed in the +filter action section above. Please
7950 keep these listings in sync.
7955 The distribution <filename>default.filter</filename> file contains a selection of
7956 pre-defined filters for your convenience:
7961 <term><emphasis>js-annoyances</emphasis></term>
7964 The purpose of this filter is to get rid of particularly annoying JavaScript abuse.
7969 replaces JavaScript references to the browser's referrer information
7970 with the string "Not Your Business!". This compliments the <literal><link
7971 linkend="hide-referrer">hide-referrer</link></literal> action on the content level.
7976 removes the bindings to the DOM's
7977 <ulink url="http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-htmlevents">unload
7978 event</ulink> which we feel has no right to exist and is responsible for most <quote>exit consoles</quote>, i.e.
7979 nasty windows that pop up when you close another one.
7984 removes code that causes new windows to be opened with undesired properties, such as being
7985 full-screen, non-resizeable, without location, status or menu bar etc.
7991 Use with caution. This is an aggressive filter, and can break sites that
7992 rely heavily on JavaScript.
7998 <term><emphasis>js-events</emphasis></term>
8001 This is a very radical measure. It removes virtually all JavaScript event bindings, which
8002 means that scripts can not react to user actions such as mouse movements or clicks, window
8003 resizing etc, anymore. Use with caution!
8006 We <emphasis>strongly discourage</emphasis> using this filter as a default since it breaks
8007 many legitimate scripts. It is meant for use only on extra-nasty sites (should you really
8014 <term><emphasis>html-annoyances</emphasis></term>
8017 This filter will undo many common instances of HTML based abuse.
8020 The <literal>BLINK</literal> and <literal>MARQUEE</literal> tags
8021 are neutralized (yeah baby!), and browser windows will be created as
8022 resizeable (as of course they should be!), and will have location,
8023 scroll and menu bars -- even if specified otherwise.
8029 <term><emphasis>content-cookies</emphasis></term>
8032 Most cookies are set in the HTTP dialog, where they can be intercepted
8034 <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal>
8035 and <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal>
8036 actions. But web sites increasingly make use of HTML meta tags and JavaScript
8037 to sneak cookies to the browser on the content level.
8040 This filter disables most HTML and JavaScript code that reads or sets
8041 cookies. It cannot detect all clever uses of these types of code, so it
8042 should not be relied on as an absolute fix. Use it wherever you would also
8043 use the cookie crunch actions.
8049 <term><emphasis>refresh-tags</emphasis></term>
8052 Disable any refresh tags if the interval is greater than nine seconds (so
8053 that redirections done via refresh tags are not destroyed). This is useful
8054 for dial-on-demand setups, or for those who find this HTML feature
8061 <term><emphasis>unsolicited-popups</emphasis></term>
8064 This filter attempts to prevent only <quote>unsolicited</quote> pop-up
8065 windows from opening, yet still allow pop-up windows that the user
8066 has explicitly chosen to open. It was added in version 3.0.1,
8067 as an improvement over earlier such filters.
8070 Technical note: The filter works by redefining the window.open JavaScript
8071 function to a dummy function, <literal>PrivoxyWindowOpen()</literal>,
8072 during the loading and rendering phase of each HTML page access, and
8073 restoring the function afterward.
8076 This is recommended only for browsers that cannot perform this function
8077 reliably themselves. And be aware that some sites require such windows
8078 in order to function normally. Use with caution.
8084 <term><emphasis>all-popups</emphasis></term>
8087 Attempt to prevent <emphasis>all</emphasis> pop-up windows from opening.
8088 Note this should be used with even more discretion than the above, since
8089 it is more likely to break some sites that require pop-ups for normal
8090 usage. Use with caution.
8096 <term><emphasis>img-reorder</emphasis></term>
8099 This is a helper filter that has no value if used alone. It makes the
8100 <literal>banners-by-size</literal> and <literal>banners-by-link</literal>
8101 (see below) filters more effective and should be enabled together with them.
8107 <term><emphasis>banners-by-size</emphasis></term>
8110 This filter removes image tags purely based on what size they are. Fortunately
8111 for us, many ads and banner images tend to conform to certain standardized
8112 sizes, which makes this filter quite effective for ad stripping purposes.
8115 Occasionally this filter will cause false positives on images that are not ads,
8116 but just happen to be of one of the standard banner sizes.
8119 Recommended only for those who require extreme ad blocking. The default
8120 block rules should catch 95+% of all ads <emphasis>without</emphasis> this filter enabled.
8126 <term><emphasis>banners-by-link</emphasis></term>
8129 This is an experimental filter that attempts to kill any banners if
8130 their URLs seem to point to known or suspected click trackers. It is currently
8131 not of much value and is not recommended for use by default.
8137 <term><emphasis>webbugs</emphasis></term>
8140 Webbugs are small, invisible images (technically 1X1 GIF images), that
8141 are used to track users across websites, and collect information on them.
8142 As an HTML page is loaded by the browser, an embedded image tag causes the
8143 browser to contact a third-party site, disclosing the tracking information
8144 through the requested URL and/or cookies for that third-party domain, without
8145 the user ever becoming aware of the interaction with the third-party site.
8146 HTML-ized spam also uses a similar technique to verify email addresses.
8149 This filter removes the HTML code that loads such <quote>webbugs</quote>.
8155 <term><emphasis>tiny-textforms</emphasis></term>
8158 A rather special-purpose filter that can be used to enlarge textareas (those
8159 multi-line text boxes in web forms) and turn off hard word wrap in them.
8160 It was written for the sourceforge.net tracker system where such boxes are
8161 a nuisance, but it can be handy on other sites, too.
8164 It is not recommended to use this filter as a default.
8170 <term><emphasis>jumping-windows</emphasis></term>
8173 Many consider windows that move, or resize themselves to be abusive. This filter
8174 neutralizes the related JavaScript code. Note that some sites might not display
8175 or behave as intended when using this filter. Use with caution.
8181 <term><emphasis>frameset-borders</emphasis></term>
8184 Some web designers seem to assume that everyone in the world will view their
8185 web sites using the same browser brand and version, screen resolution etc,
8186 because only that assumption could explain why they'd use static frame sizes,
8187 yet prevent their frames from being resized by the user, should they be too
8188 small to show their whole content.
8191 This filter removes the related HTML code. It should only be applied to sites
8198 <term><emphasis>demoronizer</emphasis></term>
8201 Many Microsoft products that generate HTML use non-standard extensions (read:
8202 violations) of the ISO 8859-1 aka Latin-1 character set. This can cause those
8203 HTML documents to display with errors on standard-compliant platforms.
8206 This filter translates the MS-only characters into Latin-1 equivalents.
8207 It is not necessary when using MS products, and will cause corruption of
8208 all documents that use 8-bit character sets other than Latin-1. It's mostly
8209 worthwhile for Europeans on non-MS platforms, if weird garbage characters
8210 sometimes appear on some pages, or user agents that don't correct for this on
8213 My version of Mozilla (ancient) shows litte square boxes for quote
8214 characters, and apostrophes on moronized pages. So many pages have this, I
8215 can read them fine now. HB 08/27/06
8222 <term><emphasis>shockwave-flash</emphasis></term>
8225 A filter for shockwave haters. As the name suggests, this filter strips code
8226 out of web pages that is used to embed shockwave flash objects.
8234 <term><emphasis>quicktime-kioskmode</emphasis></term>
8237 Change HTML code that embeds Quicktime objects so that kioskmode, which
8238 prevents saving, is disabled.
8244 <term><emphasis>fun</emphasis></term>
8247 Text replacements for subversive browsing fun. Make fun of your favorite
8248 Monopolist or play buzzword bingo.
8254 <term><emphasis>crude-parental</emphasis></term>
8257 A demonstration-only filter that shows how <application>Privoxy</application>
8258 can be used to delete web content on a keyword basis.
8264 <term><emphasis>ie-exploits</emphasis></term>
8267 An experimental collection of text replacements to disable malicious HTML and JavaScript
8268 code that exploits known security holes in Internet Explorer.
8271 Presently, it only protects against Nimda and a cross-site scripting bug, and
8272 would need active maintenance to provide more substantial protection.
8278 <term><emphasis>site-specifics</emphasis></term>
8281 Some web sites have very specific problems, the cure for which doesn't apply
8282 anywhere else, or could even cause damage on other sites.
8285 This is a collection of such site-specific cures which should only be applied
8286 to the sites they were intended for, which is what the supplied
8287 <filename>default.action</filename> file does. Users shouldn't need to change
8288 anything regarding this filter.
8294 <term><emphasis>google</emphasis></term>
8297 A CSS based block for Google text ads. Also removes a width limitation
8298 and the toolbar advertisement.
8304 <term><emphasis>yahoo</emphasis></term>
8307 Another CSS based block, this time for Yahoo text ads. And removes
8308 a width limitation as well.
8314 <term><emphasis>msn</emphasis></term>
8317 Another CSS based block, this time for MSN text ads. And removes
8318 tracking URLs, as well as a width limitation.
8324 <term><emphasis>blogspot</emphasis></term>
8327 Cleans up some Blogspot blogs. Read the fine print before using this one!
8330 This filter also intentionally removes some navigation stuff and sets the
8331 page width to 100%. As a result, some rounded <quote>corners</quote> would
8332 appear to early or not at all and as fixing this would require a browser
8333 that understands background-size (CSS3), they are removed instead.
8339 <term><emphasis>xml-to-html</emphasis></term>
8342 Server-header filter to change the Content-Type from xml to html.
8348 <term><emphasis>html-to-xml</emphasis></term>
8351 Server-header filter to change the Content-Type from html to xml.
8357 <term><emphasis>no-ping</emphasis></term>
8360 Removes the non-standard <literal>ping</literal> attribute from
8361 anchor and area HTML tags.
8367 <term><emphasis>hide-tor-exit-notation</emphasis></term>
8370 Client-header filter to remove the <command>Tor</command> exit node notation
8371 found in Host and Referer headers.
8374 If &my-app; and <command>Tor</command> are chained and &my-app;
8375 is configured to use socks4a, one can use <quote>http://www.example.org.foobar.exit/</quote>
8376 to access the host <quote>www.example.org</quote> through the
8377 <command>Tor</command> exit node <quote>foobar</quote>.
8380 As the HTTP client isn't aware of this notation, it treats the
8381 whole string <quote>www.example.org.foobar.exit</quote> as host and uses it
8382 for the <quote>Host</quote> and <quote>Referer</quote> headers. From the
8383 server's point of view the resulting headers are invalid and can cause problems.
8386 An invalid <quote>Referer</quote> header can trigger <quote>hot-linking</quote>
8387 protections, an invalid <quote>Host</quote> header will make it impossible for
8388 the server to find the right vhost (several domains hosted on the same IP address).
8391 This client-header filter removes the <quote>foo.exit</quote> part in those headers
8392 to prevent the mentioned problems. Note that it only modifies
8393 the HTTP headers, it doesn't make it impossible for the server
8394 to detect your <command>Tor</command> exit node based on the IP address
8395 the request is coming from.
8402 <term><emphasis> </emphasis></term>
8416 <!-- ~ End section ~ -->
8420 <!-- ~~~~~ New section ~~~~~ -->
8422 <sect1 id="templates">
8423 <title>Privoxy's Template Files</title>
8425 All <application>Privoxy</application> built-in pages, i.e. error pages such as the
8426 <ulink url="http://show-the-404-error.page"><quote>404 - No Such Domain</quote>
8427 error page</ulink>, the <ulink
8428 url="http://ads.bannerserver.example.com/nasty-ads/sponsor.html"><quote>BLOCKED</quote>
8430 and all pages of its <ulink url="http://config.privoxy.org/">web-based
8431 user interface</ulink>, are generated from <emphasis>templates</emphasis>.
8432 (<application>Privoxy</application> must be running for the above links to work as
8437 These templates are stored in a subdirectory of the <link linkend="confdir">configuration
8438 directory</link> called <filename>templates</filename>. On Unixish platforms,
8440 <ulink url="file:///etc/privoxy/templates/"><filename>/etc/privoxy/templates/</filename></ulink>.
8444 The templates are basically normal HTML files, but with place-holders (called symbols
8445 or exports), which <application>Privoxy</application> fills at run time. It
8446 is possible to edit the templates with a normal text editor, should you want
8447 to customize them. (<emphasis>Not recommended for the casual
8448 user</emphasis>). Should you create your own custom templates, you should use
8449 the <filename>config</filename> setting <link linkend="templdir">templdir</link>
8450 to specify an alternate location, so your templates do not get overwritten
8454 Note that just like in configuration files, lines starting
8455 with <literal>#</literal> are ignored when the templates are filled in.
8459 The place-holders are of the form <literal>@name@</literal>, and you will
8460 find a list of available symbols, which vary from template to template,
8461 in the comments at the start of each file. Note that these comments are not
8462 always accurate, and that it's probably best to look at the existing HTML
8463 code to find out which symbols are supported and what they are filled in with.
8467 A special application of this substitution mechanism is to make whole
8468 blocks of HTML code disappear when a specific symbol is set. We use this
8469 for many purposes, one of them being to include the beta warning in all
8470 our user interface (CGI) pages when <application>Privoxy</application>
8471 is in an alpha or beta development stage:
8476 <!-- @if-unstable-start -->
8478 ... beta warning HTML code goes here ...
8480 <!-- if-unstable-end@ --></screen>
8484 If the "unstable" symbol is set, everything in between and including
8485 <literal>@if-unstable-start</literal> and <literal>if-unstable-end@</literal>
8486 will disappear, leaving nothing but an empty comment:
8490 <screen><!-- --></screen>
8494 There's also an if-then-else construct and an <literal>#include</literal>
8495 mechanism, but you'll sure find out if you are inclined to edit the
8500 All templates refer to a style located at
8501 <ulink url="http://config.privoxy.org/send-stylesheet"><literal>http://config.privoxy.org/send-stylesheet</literal></ulink>.
8502 This is, of course, locally served by <application>Privoxy</application>
8503 and the source for it can be found and edited in the
8504 <filename>cgi-style.css</filename> template.
8509 <!-- ~ End section ~ -->
8513 <!-- ~~~~~ New section ~~~~~ -->
8515 <sect1 id="contact"><title>Contacting the Developers, Bug Reporting and Feature
8518 <!-- Include contacting.sgml boilerplate: -->
8520 <!-- end boilerplate -->
8524 <!-- ~ End section ~ -->
8527 <!-- ~~~~~ New section ~~~~~ -->
8528 <sect1 id="copyright"><title>Privoxy Copyright, License and History</title>
8530 <!-- Include copyright.sgml: -->
8532 <!-- end copyright -->
8534 <!-- ~~~~~ New section ~~~~~ -->
8535 <sect2><title>License</title>
8536 <!-- Include copyright.sgml: -->
8538 <!-- end copyright -->
8540 <!-- ~ End section ~ -->
8543 <!-- ~~~~~ New section ~~~~~ -->
8545 <sect2 id="history"><title>History</title>
8546 <!-- Include history.sgml: -->
8548 <!-- end history -->
8551 <sect2 id="authors"><title>Authors</title>
8552 <!-- Include p-authors.sgml: -->
8554 <!-- end authors -->
8559 <!-- ~ End section ~ -->
8562 <!-- ~~~~~ New section ~~~~~ -->
8563 <sect1 id="seealso"><title>See Also</title>
8564 <!-- Include seealso.sgml: -->
8566 <!-- end seealso -->
8571 <!-- ~~~~~ New section ~~~~~ -->
8572 <sect1 id="appendix"><title>Appendix</title>
8575 <!-- ~~~~~ New section ~~~~~ -->
8577 <title>Regular Expressions</title>
8579 <application>Privoxy</application> uses Perl-style <quote>regular
8580 expressions</quote> in its <link linkend="actions-file">actions
8581 files</link> and <link linkend="filter-file">filter file</link>,
8582 through the <ulink url="http://www.pcre.org/">PCRE</ulink> and
8585 <ulink url="http://www.oesterhelt.org/pcrs/">PCRS</ulink> libraries.
8587 <application>PCRS</application> libraries.
8591 If you are reading this, you probably don't understand what <quote>regular
8592 expressions</quote> are, or what they can do. So this will be a very brief
8593 introduction only. A full explanation would require a <ulink
8594 url="http://www.oreilly.com/catalog/regex/">book</ulink> ;-)
8598 Regular expressions provide a language to describe patterns that can be
8599 run against strings of characters (letter, numbers, etc), to see if they
8600 match the string or not. The patterns are themselves (sometimes complex)
8601 strings of literal characters, combined with wild-cards, and other special
8602 characters, called meta-characters. The <quote>meta-characters</quote> have
8603 special meanings and are used to build complex patterns to be matched against.
8604 Perl Compatible Regular Expressions are an especially convenient
8605 <quote>dialect</quote> of the regular expression language.
8609 To make a simple analogy, we do something similar when we use wild-card
8610 characters when listing files with the <command>dir</command> command in DOS.
8611 <literal>*.*</literal> matches all filenames. The <quote>special</quote>
8612 character here is the asterisk which matches any and all characters. We can be
8613 more specific and use <literal>?</literal> to match just individual
8614 characters. So <quote>dir file?.text</quote> would match
8615 <quote>file1.txt</quote>, <quote>file2.txt</quote>, etc. We are pattern
8616 matching, using a similar technique to <quote>regular expressions</quote>!
8620 Regular expressions do essentially the same thing, but are much, much more
8621 powerful. There are many more <quote>special characters</quote> and ways of
8622 building complex patterns however. Let's look at a few of the common ones,
8623 and then some examples:
8628 <emphasis>.</emphasis> - Matches any single character, e.g. <quote>a</quote>,
8629 <quote>A</quote>, <quote>4</quote>, <quote>:</quote>, or <quote>@</quote>.
8631 </simplelist></para>
8635 <emphasis>?</emphasis> - The preceding character or expression is matched ZERO or ONE
8638 </simplelist></para>
8642 <emphasis>+</emphasis> - The preceding character or expression is matched ONE or MORE
8645 </simplelist></para>
8649 <emphasis>*</emphasis> - The preceding character or expression is matched ZERO or MORE
8652 </simplelist></para>
8656 <emphasis>\</emphasis> - The <quote>escape</quote> character denotes that
8657 the following character should be taken literally. This is used where one of the
8658 special characters (e.g. <quote>.</quote>) needs to be taken literally and
8659 not as a special meta-character. Example: <quote>example\.com</quote>, makes
8660 sure the period is recognized only as a period (and not expanded to its
8661 meta-character meaning of any single character).
8663 </simplelist></para>
8667 <emphasis>[ ]</emphasis> - Characters enclosed in brackets will be matched if
8668 any of the enclosed characters are encountered. For instance, <quote>[0-9]</quote>
8669 matches any numeric digit (zero through nine). As an example, we can combine
8670 this with <quote>+</quote> to match any digit one of more times: <quote>[0-9]+</quote>.
8672 </simplelist></para>
8676 <emphasis>( )</emphasis> - parentheses are used to group a sub-expression,
8677 or multiple sub-expressions.
8679 </simplelist></para>
8683 <emphasis>|</emphasis> - The <quote>bar</quote> character works like an
8684 <quote>or</quote> conditional statement. A match is successful if the
8685 sub-expression on either side of <quote>|</quote> matches. As an example:
8686 <quote>/(this|that) example/</quote> uses grouping and the bar character
8687 and would match either <quote>this example</quote> or <quote>that
8688 example</quote>, and nothing else.
8690 </simplelist></para>
8693 These are just some of the ones you are likely to use when matching URLs with
8694 <application>Privoxy</application>, and is a long way from a definitive
8695 list. This is enough to get us started with a few simple examples which may
8696 be more illuminating:
8700 <emphasis><literal>/.*/banners/.*</literal></emphasis> - A simple example
8701 that uses the common combination of <quote>.</quote> and <quote>*</quote> to
8702 denote any character, zero or more times. In other words, any string at all.
8703 So we start with a literal forward slash, then our regular expression pattern
8704 (<quote>.*</quote>) another literal forward slash, the string
8705 <quote>banners</quote>, another forward slash, and lastly another
8706 <quote>.*</quote>. We are building
8707 a directory path here. This will match any file with the path that has a
8708 directory named <quote>banners</quote> in it. The <quote>.*</quote> matches
8709 any characters, and this could conceivably be more forward slashes, so it
8710 might expand into a much longer looking path. For example, this could match:
8711 <quote>/eye/hate/spammers/banners/annoy_me_please.gif</quote>, or just
8712 <quote>/banners/annoying.html</quote>, or almost an infinite number of other
8713 possible combinations, just so it has <quote>banners</quote> in the path
8718 And now something a little more complex:
8722 <emphasis><literal>/.*/adv((er)?ts?|ertis(ing|ements?))?/</literal></emphasis> -
8723 We have several literal forward slashes again (<quote>/</quote>), so we are
8724 building another expression that is a file path statement. We have another
8725 <quote>.*</quote>, so we are matching against any conceivable sub-path, just so
8726 it matches our expression. The only true literal that <emphasis>must
8727 match</emphasis> our pattern is <application>adv</application>, together with
8728 the forward slashes. What comes after the <quote>adv</quote> string is the
8733 Remember the <quote>?</quote> means the preceding expression (either a
8734 literal character or anything grouped with <quote>(...)</quote> in this case)
8735 can exist or not, since this means either zero or one match. So
8736 <quote>((er)?ts?|ertis(ing|ements?))</quote> is optional, as are the
8737 individual sub-expressions: <quote>(er)</quote>,
8738 <quote>(ing|ements?)</quote>, and the <quote>s</quote>. The <quote>|</quote>
8739 means <quote>or</quote>. We have two of those. For instance,
8740 <quote>(ing|ements?)</quote>, can expand to match either <quote>ing</quote>
8741 <emphasis>OR</emphasis> <quote>ements?</quote>. What is being done here, is an
8742 attempt at matching as many variations of <quote>advertisement</quote>, and
8743 similar, as possible. So this would expand to match just <quote>adv</quote>,
8744 or <quote>advert</quote>, or <quote>adverts</quote>, or
8745 <quote>advertising</quote>, or <quote>advertisement</quote>, or
8746 <quote>advertisements</quote>. You get the idea. But it would not match
8747 <quote>advertizements</quote> (with a <quote>z</quote>). We could fix that by
8748 changing our regular expression to:
8749 <quote>/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/</quote>, which would then match
8754 <emphasis><literal>/.*/advert[0-9]+\.(gif|jpe?g)</literal></emphasis> - Again
8755 another path statement with forward slashes. Anything in the square brackets
8756 <quote>[ ]</quote> can be matched. This is using <quote>0-9</quote> as a
8757 shorthand expression to mean any digit one through nine. It is the same as
8758 saying <quote>0123456789</quote>. So any digit matches. The <quote>+</quote>
8759 means one or more of the preceding expression must be included. The preceding
8760 expression here is what is in the square brackets -- in this case, any digit
8761 one through nine. Then, at the end, we have a grouping: <quote>(gif|jpe?g)</quote>.
8762 This includes a <quote>|</quote>, so this needs to match the expression on
8763 either side of that bar character also. A simple <quote>gif</quote> on one side, and the other
8764 side will in turn match either <quote>jpeg</quote> or <quote>jpg</quote>,
8765 since the <quote>?</quote> means the letter <quote>e</quote> is optional and
8766 can be matched once or not at all. So we are building an expression here to
8767 match image GIF or JPEG type image file. It must include the literal
8768 string <quote>advert</quote>, then one or more digits, and a <quote>.</quote>
8769 (which is now a literal, and not a special character, since it is escaped
8770 with <quote>\</quote>), and lastly either <quote>gif</quote>, or
8771 <quote>jpeg</quote>, or <quote>jpg</quote>. Some possible matches would
8772 include: <quote>//advert1.jpg</quote>,
8773 <quote>/nasty/ads/advert1234.gif</quote>,
8774 <quote>/banners/from/hell/advert99.jpg</quote>. It would not match
8775 <quote>advert1.gif</quote> (no leading slash), or
8776 <quote>/adverts232.jpg</quote> (the expression does not include an
8777 <quote>s</quote>), or <quote>/advert1.jsp</quote> (<quote>jsp</quote> is not
8778 in the expression anywhere).
8782 We are barely scratching the surface of regular expressions here so that you
8783 can understand the default <application>Privoxy</application>
8784 configuration files, and maybe use this knowledge to customize your own
8785 installation. There is much, much more that can be done with regular
8786 expressions. Now that you know enough to get started, you can learn more on
8791 More reading on Perl Compatible Regular expressions:
8792 <ulink url="http://perldoc.perl.org/perlre.html">http://perldoc.perl.org/perlre.html</ulink>
8796 For information on regular expression based substitutions and their applications
8797 in filters, please see the <link linkend="filter-file">filter file tutorial</link>
8802 <!-- ~ End section ~ -->
8805 <!-- ~~~~~ New section ~~~~~ -->
8807 <title>Privoxy's Internal Pages</title>
8810 Since <application>Privoxy</application> proxies each requested
8811 web page, it is easy for <application>Privoxy</application> to
8812 trap certain special URLs. In this way, we can talk directly to
8813 <application>Privoxy</application>, and see how it is
8814 configured, see how our rules are being applied, change these
8815 rules and other configuration options, and even turn
8816 <application>Privoxy's</application> filtering off, all with
8822 The URLs listed below are the special ones that allow direct access
8823 to <application>Privoxy</application>. Of course,
8824 <application>Privoxy</application> must be running to access these. If
8825 not, you will get a friendly error message. Internet access is not
8838 <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
8842 There is a shortcut: <ulink url="http://p.p/">http://p.p/</ulink> (But it
8843 doesn't provide a fall-back to a real page, in case the request is not
8844 sent through <application>Privoxy</application>)
8850 Show information about the current configuration, including viewing and
8851 editing of actions files:
8855 <ulink url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
8862 Show the source code version numbers:
8866 <ulink url="http://config.privoxy.org/show-version">http://config.privoxy.org/show-version</ulink>
8873 Show the browser's request headers:
8877 <ulink url="http://config.privoxy.org/show-request">http://config.privoxy.org/show-request</ulink>
8884 Show which actions apply to a URL and why:
8888 <ulink url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
8895 Toggle Privoxy on or off. This feature can be turned off/on in the main
8896 <filename>config</filename> file. When toggled <quote>off</quote>, <quote>Privoxy</quote>
8897 continues to run, but only as a pass-through proxy, with no actions taking
8902 <ulink url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>
8906 Short cuts. Turn off, then on:
8910 <ulink url="http://config.privoxy.org/toggle?set=disable">http://config.privoxy.org/toggle?set=disable</ulink>
8915 <ulink url="http://config.privoxy.org/toggle?set=enable">http://config.privoxy.org/toggle?set=enable</ulink>
8924 These may be bookmarked for quick reference. See next.
8928 <sect3 id="bookmarklets">
8929 <title>Bookmarklets</title>
8931 Below are some <quote>bookmarklets</quote> to allow you to easily access a
8932 <quote>mini</quote> version of some of <application>Privoxy's</application>
8933 special pages. They are designed for MS Internet Explorer, but should work
8934 equally well in Netscape, Mozilla, and other browsers which support
8935 JavaScript. They are designed to run directly from your bookmarks - not by
8936 clicking the links below (although that should work for testing).
8939 To save them, right-click the link and choose <quote>Add to Favorites</quote>
8940 (IE) or <quote>Add Bookmark</quote> (Netscape). You will get a warning that
8941 the bookmark <quote>may not be safe</quote> - just click OK. Then you can run the
8942 Bookmarklet directly from your favorites/bookmarks. For even faster access,
8943 you can put them on the <quote>Links</quote> bar (IE) or the <quote>Personal
8944 Toolbar</quote> (Netscape), and run them with a single click.
8953 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>
8960 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>
8967 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)
8974 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>
8980 <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>
8986 <ulink url="javascript:void(window.open('http://config.privoxy.org/show-url-info?url='+escape(location.href),'Why').focus());">Privoxy - Why?</ulink>
8993 Credit: The site which gave us the general idea for these bookmarklets is
8994 <ulink url="http://www.bookmarklets.com/">www.bookmarklets.com</ulink>. They
8995 have more information about bookmarklets.
9004 <!-- ~~~~~ New section ~~~~~ -->
9006 <title>Chain of Events</title>
9008 Let's take a quick look at how some of <application>Privoxy's</application>
9009 core features are triggered, and the ensuing sequence of events when a web
9010 page is requested by your browser:
9017 First, your web browser requests a web page. The browser knows to send
9018 the request to <application>Privoxy</application>, which will in turn,
9019 relay the request to the remote web server after passing the following
9025 <application>Privoxy</application> traps any request for its own internal CGI
9026 pages (e.g <ulink url="http://p.p/">http://p.p/</ulink>) and sends the CGI page back to the browser.
9031 Next, <application>Privoxy</application> checks to see if the URL
9033 linkend="BLOCK"><quote>+block</quote></link> patterns. If
9034 so, the URL is then blocked, and the remote web server will not be contacted.
9035 <link linkend="HANDLE-AS-IMAGE"><quote>+handle-as-image</quote></link>
9037 <link linkend="HANDLE-AS-EMPTY-DOCUMENT"><quote>+handle-as-empty-document</quote></link>
9038 are then checked, and if there is no match, an
9039 HTML <quote>BLOCKED</quote> page is sent back to the browser. Otherwise, if
9040 it does match, an image is returned for the former, and an empty text
9041 document for the latter. The type of image would depend on the setting of
9042 <link linkend="SET-IMAGE-BLOCKER"><quote>+set-image-blocker</quote></link>
9043 (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
9048 Untrusted URLs are blocked. If URLs are being added to the
9049 <filename>trust</filename> file, then that is done.
9054 If the URL pattern matches the <link
9055 linkend="FAST-REDIRECTS"><quote>+fast-redirects</quote></link> action,
9056 it is then processed. Unwanted parts of the requested URL are stripped.
9061 Now the rest of the client browser's request headers are processed. If any
9062 of these match any of the relevant actions (e.g. <link
9063 linkend="HIDE-USER-AGENT"><quote>+hide-user-agent</quote></link>,
9064 etc.), headers are suppressed or forged as determined by these actions and
9070 Now the web server starts sending its response back (i.e. typically a web
9076 First, the server headers are read and processed to determine, among other
9077 things, the MIME type (document type) and encoding. The headers are then
9078 filtered as determined by the
9079 <link linkend="CRUNCH-INCOMING-COOKIES"><quote>+crunch-incoming-cookies</quote></link>,
9080 <link linkend="SESSION-COOKIES-ONLY"><quote>+session-cookies-only</quote></link>,
9081 and <link linkend="DOWNGRADE-HTTP-VERSION"><quote>+downgrade-http-version</quote></link>
9087 If any <link linkend="FILTER"><quote>+filter</quote></link> action
9089 linkend="DEANIMATE-GIFS"><quote>+deanimate-gifs</quote></link>
9090 action applies (and the document type fits the action), the rest of the page is
9091 read into memory (up to a configurable limit). Then the filter rules (from
9092 <filename>default.filter</filename> and any other filter files) are
9093 processed against the buffered content. Filters are applied in the order
9094 they are specified in one of the filter files. Animated GIFs, if present,
9095 are reduced to either the first or last frame, depending on the action
9096 setting.The entire page, which is now filtered, is then sent by
9097 <application>Privoxy</application> back to your browser.
9100 If neither a <link linkend="FILTER"><quote>+filter</quote></link> action
9102 linkend="DEANIMATE-GIFS"><quote>+deanimate-gifs</quote></link>
9103 matches, then <application>Privoxy</application> passes the raw data through
9104 to the client browser as it becomes available.
9109 As the browser receives the now (possibly filtered) page content, it
9110 reads and then requests any URLs that may be embedded within the page
9111 source, e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
9112 frames), sounds, etc. For each of these objects, the browser issues a
9113 separate request (this is easily viewable in <application>Privoxy's</application>
9114 logs). And each such request is in turn processed just as above. Note that a
9115 complex web page will have many, many such embedded URLs. If these
9116 secondary requests are to a different server, then quite possibly a very
9117 differing set of actions is triggered.
9124 NOTE: This is somewhat of a simplistic overview of what happens with each URL
9125 request. For the sake of brevity and simplicity, we have focused on
9126 <application>Privoxy's</application> core features only.
9132 <!-- ~~~~~ New section ~~~~~ -->
9133 <sect2 id="actionsanat">
9134 <title>Troubleshooting: Anatomy of an Action</title>
9137 The way <application>Privoxy</application> applies
9138 <link linkend="ACTIONS">actions</link> and <link linkend="FILTER">filters</link>
9139 to any given URL can be complex, and not always so
9140 easy to understand what is happening. And sometimes we need to be able to
9141 <emphasis>see</emphasis> just what <application>Privoxy</application> is
9142 doing. Especially, if something <application>Privoxy</application> is doing
9143 is causing us a problem inadvertently. It can be a little daunting to look at
9144 the actions and filters files themselves, since they tend to be filled with
9145 <link linkend="regex">regular expressions</link> whose consequences are not
9150 One quick test to see if <application>Privoxy</application> is causing a problem
9151 or not, is to disable it temporarily. This should be the first troubleshooting
9152 step. See <link linkend="bookmarklets">the Bookmarklets</link> section on a quick
9153 and easy way to do this (be sure to flush caches afterward!). Looking at the
9154 logs is a good idea too. (Note that both the toggle feature and logging are
9155 enabled via <filename>config</filename> file settings, and may need to be
9156 turned <quote>on</quote>.)
9159 Another easy troubleshooting step to try is if you have done any
9160 customization of your installation, revert back to the installed
9161 defaults and see if that helps. There are times the developers get complaints
9162 about one thing or another, and the problem is more related to a customized
9163 configuration issue.
9167 <application>Privoxy</application> also provides the
9168 <ulink url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
9169 page that can show us very specifically how <application>actions</application>
9170 are being applied to any given URL. This is a big help for troubleshooting.
9174 First, enter one URL (or partial URL) at the prompt, and then
9175 <application>Privoxy</application> will tell us
9176 how the current configuration will handle it. This will not
9177 help with filtering effects (i.e. the <link
9178 linkend="FILTER"><quote>+filter</quote></link> action) from
9179 one of the filter files since this is handled very
9180 differently and not so easy to trap! It also will not tell you about any other
9181 URLs that may be embedded within the URL you are testing. For instance, images
9182 such as ads are expressed as URLs within the raw page source of HTML pages. So
9183 you will only get info for the actual URL that is pasted into the prompt area
9184 -- not any sub-URLs. If you want to know about embedded URLs like ads, you
9185 will have to dig those out of the HTML source. Use your browser's <quote>View
9186 Page Source</quote> option for this. Or right click on the ad, and grab the
9191 Let's try an example, <ulink url="http://google.com">google.com</ulink>,
9192 and look at it one section at a time in a sample configuration (your real
9193 configuration may vary):
9198 Matches for http://www.google.com:
9200 In file: default.action <guibutton>[ View ]</guibutton> <guibutton>[ Edit ]</guibutton>
9202 {+change-x-forwarded-for{block}
9203 +deanimate-gifs {last}
9204 +fast-redirects {check-decoded-url}
9205 +filter {refresh-tags}
9206 +filter {img-reorder}
9207 +filter {banners-by-size}
9209 +filter {jumping-windows}
9210 +filter {ie-exploits}
9211 +hide-from-header {block}
9212 +hide-referrer {forge}
9213 +session-cookies-only
9214 +set-image-blocker {pattern}
9217 { -session-cookies-only }
9223 In file: user.action <guibutton>[ View ]</guibutton> <guibutton>[ Edit ]</guibutton>
9224 (no matches in this file)
9229 This is telling us how we have defined our
9230 <link linkend="ACTIONS"><quote>actions</quote></link>, and
9231 which ones match for our test case, <quote>google.com</quote>.
9232 Displayed is all the actions that are available to us. Remember,
9233 the <literal>+</literal> sign denotes <quote>on</quote>. <literal>-</literal>
9234 denotes <quote>off</quote>. So some are <quote>on</quote> here, but many
9235 are <quote>off</quote>. Each example we try may provide a slightly different
9236 end result, depending on our configuration directives.
9240 is for our <filename>default.action</filename> file. The large, multi-line
9241 listing, is how the actions are set to match for all URLs, i.e. our default
9242 settings. If you look at your <quote>actions</quote> file, this would be the
9243 section just below the <quote>aliases</quote> section near the top. This
9244 will apply to all URLs as signified by the single forward slash at the end
9245 of the listing -- <quote> / </quote>.
9249 But we have defined additional actions that would be exceptions to these general
9250 rules, and then we list specific URLs (or patterns) that these exceptions
9251 would apply to. Last match wins. Just below this then are two explicit
9252 matches for <quote>.google.com</quote>. The first is negating our previous
9253 cookie setting, which was for <link
9254 linkend="SESSION-COOKIES-ONLY"><quote>+session-cookies-only</quote></link>
9255 (i.e. not persistent). So we will allow persistent cookies for google, at
9256 least that is how it is in this example. The second turns
9257 <emphasis>off</emphasis> any <link
9258 linkend="FAST-REDIRECTS"><quote>+fast-redirects</quote></link>
9259 action, allowing this to take place unmolested. Note that there is a leading
9260 dot here -- <quote>.google.com</quote>. This will match any hosts and
9261 sub-domains, in the google.com domain also, such as
9262 <quote>www.google.com</quote> or <quote>mail.google.com</quote>. But it would not
9263 match <quote>www.google.de</quote>! So, apparently, we have these two actions
9264 defined as exceptions to the general rules at the top somewhere in the lower
9265 part of our <filename>default.action</filename> file, and
9266 <quote>google.com</quote> is referenced somewhere in these latter sections.
9270 Then, for our <filename>user.action</filename> file, we again have no hits.
9271 So there is nothing google-specific that we might have added to our own, local
9272 configuration. If there was, those actions would over-rule any actions from
9273 previously processed files, such as <filename>default.action</filename>.
9274 <filename>user.action</filename> typically has the last word. This is the
9275 best place to put hard and fast exceptions,
9279 And finally we pull it all together in the bottom section and summarize how
9280 <application>Privoxy</application> is applying all its <quote>actions</quote>
9281 to <quote>google.com</quote>:
9292 +change-x-forwarded-for{block}
9293 -client-header-filter{hide-tor-exit-notation}
9294 -content-type-overwrite
9295 -crunch-client-header
9296 -crunch-if-none-match
9297 -crunch-incoming-cookies
9298 -crunch-outgoing-cookies
9299 -crunch-server-header
9300 +deanimate-gifs {last}
9301 -downgrade-http-version
9304 -filter {content-cookies}
9305 -filter {all-popups}
9306 -filter {banners-by-link}
9307 -filter {tiny-textforms}
9308 -filter {frameset-borders}
9309 -filter {demoronizer}
9310 -filter {shockwave-flash}
9311 -filter {quicktime-kioskmode}
9313 -filter {crude-parental}
9314 -filter {site-specifics}
9315 -filter {js-annoyances}
9316 -filter {html-annoyances}
9317 +filter {refresh-tags}
9318 -filter {unsolicited-popups}
9319 +filter {img-reorder}
9320 +filter {banners-by-size}
9322 +filter {jumping-windows}
9323 +filter {ie-exploits}
9330 -handle-as-empty-document
9332 -hide-accept-language
9333 -hide-content-disposition
9334 +hide-from-header {block}
9335 -hide-if-modified-since
9336 +hide-referrer {forge}
9339 -overwrite-last-modified
9340 -prevent-compression
9342 -server-header-filter{xml-to-html}
9343 -server-header-filter{html-to-xml}
9344 -session-cookies-only
9345 +set-image-blocker {pattern} </screen>
9349 Notice the only difference here to the previous listing, is to
9350 <quote>fast-redirects</quote> and <quote>session-cookies-only</quote>,
9351 which are activated specifically for this site in our configuration,
9352 and thus show in the <quote>Final Results</quote>.
9356 Now another example, <quote>ad.doubleclick.net</quote>:
9362 { +block{Domains starts with "ad"} }
9365 { +block{Domain contains "ad"} }
9368 { +block{Doubleclick banner server} +handle-as-image }
9369 .[a-vx-z]*.doubleclick.net
9374 We'll just show the interesting part here - the explicit matches. It is
9375 matched three different times. Two <quote>+block{}</quote> sections,
9376 and a <quote>+block{} +handle-as-image</quote>,
9377 which is the expanded form of one of our aliases that had been defined as:
9378 <quote>+block-as-image</quote>. (<link
9379 linkend="ALIASES"><quote>Aliases</quote></link> are defined in
9380 the first section of the actions file and typically used to combine more
9385 Any one of these would have done the trick and blocked this as an unwanted
9386 image. This is unnecessarily redundant since the last case effectively
9387 would also cover the first. No point in taking chances with these guys
9388 though ;-) Note that if you want an ad or obnoxious
9389 URL to be invisible, it should be defined as <quote>ad.doubleclick.net</quote>
9390 is done here -- as both a <link
9391 linkend="BLOCK"><quote>+block{}</quote></link>
9392 <emphasis>and</emphasis> an
9393 <link linkend="HANDLE-AS-IMAGE"><quote>+handle-as-image</quote></link>.
9394 The custom alias <quote><literal>+block-as-image</literal></quote> just
9395 simplifies the process and make it more readable.
9399 One last example. Let's try <quote>http://www.example.net/adsl/HOWTO/</quote>.
9400 This one is giving us problems. We are getting a blank page. Hmmm ...
9406 Matches for http://www.example.net/adsl/HOWTO/:
9408 In file: default.action <guibutton>[ View ]</guibutton> <guibutton>[ Edit ]</guibutton>
9412 +change-x-forwarded-for{block}
9413 -client-header-filter{hide-tor-exit-notation}
9414 -content-type-overwrite
9415 -crunch-client-header
9416 -crunch-if-none-match
9417 -crunch-incoming-cookies
9418 -crunch-outgoing-cookies
9419 -crunch-server-header
9421 -downgrade-http-version
9422 +fast-redirects {check-decoded-url}
9424 -filter {content-cookies}
9425 -filter {all-popups}
9426 -filter {banners-by-link}
9427 -filter {tiny-textforms}
9428 -filter {frameset-borders}
9429 -filter {demoronizer}
9430 -filter {shockwave-flash}
9431 -filter {quicktime-kioskmode}
9433 -filter {crude-parental}
9434 -filter {site-specifics}
9435 -filter {js-annoyances}
9436 -filter {html-annoyances}
9437 +filter {refresh-tags}
9438 -filter {unsolicited-popups}
9439 +filter {img-reorder}
9440 +filter {banners-by-size}
9442 +filter {jumping-windows}
9443 +filter {ie-exploits}
9450 -handle-as-empty-document
9452 -hide-accept-language
9453 -hide-content-disposition
9454 +hide-from-header{block}
9455 +hide-referer{forge}
9457 -overwrite-last-modified
9458 +prevent-compression
9460 -server-header-filter{xml-to-html}
9461 -server-header-filter{html-to-xml}
9462 +session-cookies-only
9463 +set-image-blocker{blank} }
9466 { +block{Path contains "ads".} +handle-as-image }
9472 Ooops, the <quote>/adsl/</quote> is matching <quote>/ads</quote> in our
9473 configuration! But we did not want this at all! Now we see why we get the
9474 blank page. It is actually triggering two different actions here, and
9475 the effects are aggregated so that the URL is blocked, and &my-app; is told
9476 to treat the block as if it were an image. But this is, of course, all wrong.
9477 We could now add a new action below this (or better in our own
9478 <filename>user.action</filename> file) that explicitly
9479 <emphasis>un</emphasis> blocks (
9480 <link linkend="BLOCK"><quote>{-block}</quote></link>) paths with
9481 <quote>adsl</quote> in them (remember, last match in the configuration
9482 wins). There are various ways to handle such exceptions. Example:
9494 Now the page displays ;-)
9495 Remember to flush your browser's caches when making these kinds of changes to
9496 your configuration to insure that you get a freshly delivered page! Or, try
9497 using <literal>Shift+Reload</literal>.
9501 But now what about a situation where we get no explicit matches like
9508 { +block{Path starts with "ads".} +handle-as-image }
9514 That actually was very helpful and pointed us quickly to where the problem
9515 was. If you don't get this kind of match, then it means one of the default
9516 rules in the first section of <filename>default.action</filename> is causing
9517 the problem. This would require some guesswork, and maybe a little trial and
9518 error to isolate the offending rule. One likely cause would be one of the
9519 <link linkend="FILTER"><quote>+filter</quote></link> actions.
9520 These tend to be harder to troubleshoot.
9521 Try adding the URL for the site to one of aliases that turn off
9522 <link linkend="FILTER"><quote>+filter</quote></link>:
9530 .worldpay.com # for quietpc.com
9538 <quote><literal>{ shop }</literal></quote> is an <quote>alias</quote> that expands to
9539 <quote><literal>{ -filter -session-cookies-only }</literal></quote>.
9540 Or you could do your own exception to negate filtering:
9548 # Disable ALL filter actions for sites in this section
9556 This would turn off all filtering for these sites. This is best
9557 put in <filename>user.action</filename>, for local site
9558 exceptions. Note that when a simple domain pattern is used by itself (without
9559 the subsequent path portion), all sub-pages within that domain are included
9560 automatically in the scope of the action.
9564 Images that are inexplicably being blocked, may well be hitting the
9565 <link linkend="FILTER-BANNERS-BY-SIZE"><quote>+filter{banners-by-size}</quote></link>
9567 that images of certain sizes are ad banners (works well
9568 <emphasis>most of the time</emphasis> since these tend to be standardized).
9572 <quote><literal>{ fragile }</literal></quote> is an alias that disables most
9573 actions that are the most likely to cause trouble. This can be used as a
9574 last resort for problem sites.
9580 # Handle with care: easy to break
9582 mybank.example.com</screen>
9587 <emphasis>Remember to flush caches!</emphasis> Note that the
9588 <literal>mail.google</literal> reference lacks the TLD portion (e.g.
9589 <quote>.com</quote>). This will effectively match any TLD with
9590 <literal>google</literal> in it, such as <literal>mail.google.de.</literal>,
9594 If this still does not work, you will have to go through the remaining
9595 actions one by one to find which one(s) is causing the problem.
9604 This program is free software; you can redistribute it
9605 and/or modify it under the terms of the GNU General
9606 Public License as published by the Free Software
9607 Foundation; either version 2 of the License, or (at
9608 your option) any later version.
9610 This program is distributed in the hope that it will
9611 be useful, but WITHOUT ANY WARRANTY; without even the
9612 implied warranty of MERCHANTABILITY or FITNESS FOR A
9613 PARTICULAR PURPOSE. See the GNU General Public
9614 License for more details.
9616 The GNU General Public License should be included with
9617 this file. If not, you can view it at
9618 http://www.gnu.org/copyleft/gpl.html
9619 or write to the Free Software Foundation, Inc.,
9620 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
projects / privoxy.git / blob