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 2.154 2012/11/11 12:39:15 fabiankeil Exp $
39 Copyright (C) 2001-2011 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 2.154 2012/11/11 12:39:15 fabiankeil Exp $</pubdate>
67 Note: the following should generate a separate page, and a live link to it,
68 all nicely done. But it doesn't for some mysterious reason. Please leave
69 commented unless it can be fixed proper. For the time being, the
70 copyright/license declarations will be in their own sgml.
83 This is here to keep vim syntax file from breaking :/
84 If I knew enough to fix it, I would.
85 PLEASE DO NOT REMOVE! HB: hal@foobox.net
91 The <citetitle>Privoxy User Manual</citetitle> gives users information on how to
92 install, configure and use <ulink
93 url="http://www.privoxy.org/">Privoxy</ulink>.
96 <!-- Include privoxy.sgml boilerplate: -->
98 <!-- end privoxy.sgml -->
101 You can find the latest version of the <citetitle>Privoxy User Manual</citetitle> at <ulink
102 url="http://www.privoxy.org/user-manual/">http://www.privoxy.org/user-manual/</ulink>.
103 Please see the <link linkend="contact">Contact section</link> on how to
104 contact the developers.
108 <!-- Feel free to send a note to the developers at <email>ijbswa-developers@lists.sourceforge.net</email>. -->
114 <!-- ~~~~~ New section ~~~~~ -->
115 <sect1 label="1" id="introduction"><title>Introduction</title>
117 This documentation is included with the current &p-status; version of
118 <application>Privoxy</application>, v.&p-version;<![%p-not-stable;[,
119 and is mostly complete at this point. The most up to date reference for the
120 time being is still the comments in the source files and in the individual
121 configuration files. Development of a new version is currently nearing
122 completion, and includes significant changes and enhancements over
126 <!-- include only in non-stable versions -->
129 Since this is a &p-status; version, not all new features are well tested. This
130 documentation may be slightly out of sync as a result (especially with
131 CVS sources). And there <emphasis>may be</emphasis> bugs, though hopefully
136 <!-- ~~~~~ New section ~~~~~ -->
137 <sect2 id="features"><title>Features</title>
139 In addition to the core
140 features of ad blocking and
141 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookie</ulink> management,
142 <application>Privoxy</application> provides many supplemental
143 features<![%p-not-stable;[, some of them currently under development]]>,
144 that give the end-user more control, more privacy and more freedom:
146 <!-- Include newfeatures.sgml boilerplate here: -->
148 <!-- end boilerplate -->
153 <!-- ~ End section ~ -->
156 <!-- ~~~~~ New section ~~~~~ -->
157 <sect1 id="installation"><title>Installation</title>
160 <application>Privoxy</application> is available both in convenient pre-compiled
161 packages for a wide range of operating systems, and as raw source code.
162 For most users, we recommend using the packages, which can be downloaded from our
163 <ulink url="http://sourceforge.net/projects/ijbswa/">Privoxy Project
169 On some platforms, the installer may remove previously installed versions, if
170 found. (See below for your platform). In any case <emphasis>be sure to backup
171 your old configuration if it is valuable to you.</emphasis> See the <link
172 linkend="upgradersnote">note to upgraders</link> section below.
175 <!-- ~~~~~ New section ~~~~~ -->
176 <sect2 id="installation-packages"><title>Binary Packages</title>
178 How to install the binary packages depends on your operating system:
181 <!-- XXX: The installation sections should be sorted -->
183 <!-- ~~~~~ New section ~~~~~ -->
184 <sect3 id="installation-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.
308 <sect3 renderas="sect4" id="OS-X-install-from-package">
309 <title>Installation from ready-built package</title>
311 The downloaded file will either be a .pkg (for OS X 10.5 upwards) or a bzipped
312 .mpkg file (for OS X 10.4). The former can be double-clicked as is and the
313 installation will start; double-clicking the latter will unzip the .mpkg file
314 which can then be double-clicked to commence the installation.
317 The privoxy service will automatically start after a successful installation
318 (and thereafter every time your computer starts up) however you will need to
319 configure your web browser(s) to use it. To do so, configure them to use a
320 proxy for HTTP and HTTPS at the address 127.0.0.1:8118.
323 To prevent the privoxy service from automatically starting when your computer
324 starts up, remove or rename the file <literal>/Library/LaunchDaemons/org.ijbswa.privoxy.plist</literal>
325 (on OS X 10.5 and higher) or the folder named
326 <literal>/Library/StartupItems/Privoxy</literal> (on OS X 10.4 'Tiger').
329 To manually start or stop the privoxy service, use the scripts startPrivoxy.sh
330 and stopPrivoxy.sh supplied in /Applications/Privoxy. They must be run from an
331 administrator account, using sudo.
334 To uninstall, run /Applications/Privoxy/uninstall.command as sudo from an
335 administrator account.
337 <sect3 renderas="sect4" id="OS-X-install-from-source">
338 <title>Installation from source</title>
340 To build and install the Privoxy source code on OS X you will need to obtain
341 the macsetup module from the Privoxy Sourceforge CVS repository (refer to
342 Sourceforge help for details of how to set up a CVS client to have read-only
343 access to the repository). This module contains scripts that leverage the usual
344 open-source tools (available as part of Apple's free of charge Xcode
345 distribution or via the usual open-source software package managers for OS X
346 (MacPorts, Homebrew, Fink etc.) to build and then install the privoxy binary
347 and associated files. The macsetup module's README file contains complete
348 instructions for its use.
351 The privoxy service will automatically start after a successful installation
352 (and thereafter every time your computer starts up) however you will need to
353 configure your web browser(s) to use it. To do so, configure them to use a
354 proxy for HTTP and HTTPS at the address 127.0.0.1:8118.
357 To prevent the privoxy service from automatically starting when your computer
358 starts up, remove or rename the file <literal>/Library/LaunchDaemons/org.ijbswa.privoxy.plist</literal>
359 (on OS X 10.5 and higher) or the folder named
360 <literal>/Library/StartupItems/Privoxy</literal> (on OS X 10.4 'Tiger').
363 To manually start or stop the privoxy service, use the Privoxy Utility
364 for Mac OS X (also part of the macsetup module). This application can start
365 and stop the privoxy service and display its log and configuration files.
368 To uninstall, run the macsetup module's uninstall.sh as sudo from an
369 administrator account.
373 <!-- ~~~~~ New section ~~~~~ -->
374 <sect3 id="installation-amiga"><title>AmigaOS</title>
376 Copy and then unpack the <filename>lha</filename> archive to a suitable location.
377 All necessary files will be installed into <application>Privoxy</application>
378 directory, including all configuration and log files. To uninstall, just
379 remove this directory.
383 <!-- ~~~~~ New section ~~~~~ -->
384 <sect3 id="installation-tbz"><title>FreeBSD</title>
387 Privoxy is part of FreeBSD's Ports Collection, you can build and install
388 it with <literal>cd /usr/ports/www/privoxy; make install clean</literal>.
391 If you don't use the ports, you can fetch and install
392 the package with <literal>pkg_add -r privoxy</literal>.
395 The port skeleton and the package can also be downloaded from the
396 <ulink url="https://sourceforge.net/project/showfiles.php?group_id=11118">File Release
397 Page</ulink>, but there's no reason to use them unless you're interested in the
398 beta releases which are only available there.
402 <!-- ~~~~~ New section ~~~~~ -->
403 <sect3 id="installattion-gentoo"><title>Gentoo</title>
405 Gentoo source packages (Ebuilds) for <application>Privoxy</application> are
406 contained in the Gentoo Portage Tree (they are not on the download page,
407 but there is a Gentoo section, where you can see when a new
408 <application>Privoxy</application> Version is added to the Portage Tree).
411 Before installing <application>Privoxy</application> under Gentoo just do
412 first <literal>emerge --sync</literal> to get the latest changes from the
413 Portage tree. With <literal>emerge privoxy</literal> you install the latest
417 Configuration files are in <filename>/etc/privoxy</filename>, the
418 documentation is in <filename>/usr/share/doc/privoxy-&p-version;</filename>
419 and the Log directory is in <filename>/var/log/privoxy</filename>.
425 <!-- ~~~~~ New section ~~~~~ -->
426 <sect2 id="installation-source"><title>Building from Source</title>
429 The most convenient way to obtain the <application>Privoxy</application> sources
430 is to download the source tarball from our
431 <ulink url="http://sourceforge.net/project/showfiles.php?group_id=11118&package_id=10571">project download
436 If you like to live on the bleeding edge and are not afraid of using
437 possibly unstable development versions, you can check out the up-to-the-minute
438 version directly from <ulink url="http://sourceforge.net/cvs/?group_id=11118">the
439 CVS repository</ulink>.
441 deprecated...out of business.
442 or simply download <ulink
443 url="http://cvs.sourceforge.net/cvstarballs/ijbswa-cvsroot.tar.bz2">the nightly CVS
448 <!-- include buildsource.sgml boilerplate: -->
450 <!-- end boilerplate -->
453 <!-- ~~~~~ New section ~~~~~ -->
454 <sect2 id="installation-keepupdated"><title>Keeping your Installation Up-to-Date</title>
456 As user feedback comes in and development continues, we will make updated versions
457 of both the main <link linkend="actions-file">actions file</link> (as a <ulink
458 url="http://sourceforge.net/project/showfiles.php?group_id=11118&release_id=103670">separate
459 package</ulink>) and the software itself (including the actions file) available for
464 If you wish to receive an email notification whenever we release updates of
465 <application>Privoxy</application> or the actions file, <ulink
466 url="http://lists.sourceforge.net/lists/listinfo/ijbswa-announce/">subscribe
467 to our announce mailing list</ulink>, ijbswa-announce@lists.sourceforge.net.
471 In order not to lose your personal changes and adjustments when updating
472 to the latest <literal>default.action</literal> file we <emphasis>strongly
473 recommend</emphasis> that you use <literal>user.action</literal> and
474 <literal>user.filter</literal> for your local
475 customizations of <application>Privoxy</application>. See the <link
476 linkend="actions-file">Chapter on actions files</link> for details.
484 <!-- ~ End section ~ -->
486 <!-- ~~~~~ New section ~~~~~ -->
487 <sect1 id="whatsnew">
488 <title>What's New in this Release</title>
490 <application>Privoxy 3.0.19</application> is a stable release.
491 The changes since 3.0.18 stable are:
502 Prevent a segmentation fault when de-chunking buffered content.
503 It could be triggered by malicious web servers if Privoxy was
504 configured to filter the content and running on a platform
505 where SIZE_T_MAX isn't larger than UINT_MAX, which probably
506 includes most 32-bit systems. On those platforms, all Privoxy
507 versions before 3.0.19 appear to be affected.
508 To be on the safe side, this bug should be presumed to allow
509 code execution as proving that it doesn't seems unrealistic.
514 Do not expect a response from the SOCKS4/4A server until it
515 got something to respond to. This regression was introduced
516 in 3.0.18 and prevented the SOCKS4/4A negotiation from working.
517 Reported by qqqqqw in #3459781.
525 General improvements:
529 Fix an off-by-one in an error message about connect failures.
534 Use a GNUMakefile variable for the webserver root directory and
535 update the path. Sourceforge changed it which broke various
541 Update the CODE_STATUS description.
551 The following changes were made between 3.0.17 and 3.0.18:
562 If a generated redirect URL contains characters RFC 3986 doesn't
563 permit, they are (re)encoded. Not doing this makes Privoxy versions
564 from 3.0.5 to 3.0.17 susceptible to HTTP response splitting (CWE-113)
565 attacks if the +fast-redirects{check-decoded-url} action is used.
570 Fix a logic bug that could cause Privoxy to reuse a server
571 socket after it got tainted by a server-header-tagger-induced
572 block that was triggered before the whole server response had
573 been read. If keep-alive was enabled and the request following
574 the blocked one was to the same host and using the same forwarding
575 settings, Privoxy would send it on the tainted server socket.
576 While the server would simply treat it as a pipelined request,
577 Privoxy would later on fail to properly parse the server's
578 response as it would try to parse the unread data from the
579 first response as server headers for the second one.
580 Regression introduced in 3.0.17.
585 When implying keep-alive in client_connection(), remember that
586 the client didn't. Fixes a regression introduced in 3.0.13 that
587 would cause Privoxy to wait for additional client requests after
588 receiving a HTTP/1.1 request with "Connection: close" set
589 and connection sharing enabled.
590 With clients which terminates the client connection after detecting
591 that the whole body has been received it doesn't really matter,
592 but with clients that don't the connection would be kept open until
598 Fix a subtle race condition between prepare_csp_for_next_request()
599 and sweep(). A thread preparing itself for the next client request
600 could briefly appear to be inactive.
601 If all other threads were already using more recent files,
602 the thread could get its files swept away under its feet.
603 So far this has only been reproduced while stress testing in
604 valgrind while touching action files in a loop. It's unlikely
605 to have caused any actual problems in the real world.
610 Disable filters if SDCH compression is used unless filtering is forced.
611 If SDCH was combined with a supported compression algorithm, Privoxy
612 previously could try to decompress it and ditch the Content-Encoding
613 header even though the SDCH compression wasn't dealt with.
614 Reported by zebul666 in #3225863.
619 Make a copy of the --user value and only mess with that when splitting
620 user and group. On some operating systems modifying the value directly
621 is reflected in the output of ps and friends and can be misleading.
622 Reported by zepard in #3292710.
627 If forwarded-connect-retries is set, only retry if Privoxy is actually
628 forwarding the request. Previously direct connections would be retried
634 Fixed a small memory leak when retrying connections with IPv6
640 Remove an incorrect assertion in compile_dynamic_pcrs_job_list()
641 It could be triggered by a pcrs job with an invalid pcre
642 pattern (for example one that contains a lone quantifier).
647 If the --user argument user[.group] contains a dot, always bail out
648 if no group has been specified. Previously the intended, but undocumented
649 (and apparently untested), behaviour was to try interpreting the whole
650 argument as user name, but the detection was flawed and checked for '0'
651 instead of '\0', thus merely preventing group names beginning with a zero.
656 In html_code_map[], use a numeric character reference instead of '
657 which wasn't standardized before XHTML 1.0.
662 Fix an invalid free when compiled with FEATURE_GRACEFUL_TERMINATION
663 and shut down through http://config.privoxy.org/die
668 In get_actions(), fix the "temporary" backwards compatibility hack
669 to accept block actions without reason.
670 It also covered other actions that should be rejected as invalid.
671 Reported by Billy Crook.
679 General improvements:
683 Privoxy can (re)compress buffered content before delivering
684 it to the client. Disabled by default as most users wouldn't
690 The +fast-redirects{check-decoded-url} action checks URL
691 segments separately. If there are other parameters behind
692 the redirect URL, this makes it unnecessary to cut them off
693 by additionally using a +redirect{} pcrs command.
694 Initial patch submitted by Jamie Zawinski in #3429848.
699 When loading action sections, verify that the referenced filters
700 exist. Currently missing filters only result in an error message,
701 but eventually the severity will be upgraded to fatal.
706 Allow to bind to multiple separate addresses.
707 Patch set submitted by Petr Pisar in #3354485.
712 Set socket_error to errno if connecting fails in rfc2553_connect_to().
713 Previously rejected direct connections could be incorrectly reported
714 as DNS issues if Privoxy was compiled with IPv6 support.
719 Adjust url_code_map[] so spaces are replaced with %20 instead of '+'
720 While '+' can be used by client's submitting form data, this is not
721 actually what Privoxy is using the lookups for. This is more of a
722 cosmetic issue and doesn't fix any known problems.
727 When compiled without FEATURE_FAST_REDIRECTS, do not silently
728 ignore +fast-redirect{} directives
733 Added a workaround for GNU libc's strptime() reporting negative
734 year values when the parsed year is only specified with two digits.
735 On affected systems cookies with such a date would not be turned
736 into session cookies by the +session-cookies-only action.
737 Reported by Vaeinoe in #3403560
742 Fixed bind failures with certain GNU libc versions if no non-loopback
743 IP address has been configured on the system. This is mainly an issue
744 if the system is using DHCP and Privoxy is started before the network
745 is completely configured.
746 Reported by Raphael Marichez in #3349356.
747 Additional insight from Petr Pisar.
752 Privoxy log messages now use the ISO 8601 date format %Y-%m-%d.
753 It's only slightly longer than the old format, but contains
754 the full date including the year and allows sorting by date
755 (when grepping in multiple log files) without hassle.
760 In get_last_url(), do not bother trying to decode URLs that do
761 not contain at least one '%' sign. It reduces the log noise and
762 a number of unnecessary memory allocations.
767 In case of SOCKS5 failures, dump the socks response in the log message.
772 Simplify the signal setup in main().
777 Streamline socks5_connect() slightly.
782 In socks5_connect(), require a complete socks response from the server.
783 Previously Privoxy didn't care how much data the server response
784 contained as long as the first two bytes contained the expected
785 values. While at it, shrink the buffer size so Privoxy can't read
786 more than a whole socks response.
791 In chat(), do not bother to generate a client request in case of
792 direct CONNECT requests. It will not be used anyway.
797 Reduce server_last_modified()'s stack size.
802 Shorten get_http_time() by using strftime().
807 Constify the known_http_methods pointers in unknown_method().
812 Constify the time_formats pointers in parse_header_time().
817 Constify the formerly_valid_actions pointers in action_used_to_be_valid().
822 Introduce a GNUMakefile MAN_PAGE variable that defaults to privoxy.1.
823 The Debian package uses section 8 for the man page and this
824 should simplify the patch.
829 Deduplicate the INADDR_NONE definition for Solaris by moving it to jbsockets.h
834 In block_url(), ditch the obsolete workaround for ancient Netscape versions
835 that supposedly couldn't properly deal with status code 403.
840 Remove a useless NULL pointer check in load_trustfile().
845 Remove two useless NULL pointer checks in load_one_re_filterfile().
850 Change url_code_map[] from an array of pointers to an array of arrays
851 It removes an unnecessary layer of indirection and on 64bit system reduces
852 the size of the binary a bit.
857 Fix various typos. Fixes taken from Debian's 29_typos.dpatch by Roland Rosenfeld.
862 Add a dok-tidy GNUMakefile target to clean up the messy HTML
863 generated by the other dok targets.
868 GNUisms in the GNUMakefile have been removed.
873 Change the HTTP version in static responses to 1.1
878 Synced config.sub and config.guess with upstream
879 2011-11-11/386c7218162c145f5f9e1ff7f558a3fbb66c37c5.
884 Add a dedicated function to parse the values of toggles. Reduces duplicated
885 code in load_config() and provides better error handling. Invalid or missing
886 toggle values are now a fatal error instead of being silently ignored.
891 Terminate HTML lines in static error messages with \n instead of \r\n.
896 Simplify cgi_error_unknown() a bit.
901 In LogPutString(), don't bother looking at pszText when not
902 actually logging anything.
907 Change ssplit()'s fourth parameter from int to size_t.
908 Fixes a clang complaint.
913 Add a warning that the statistics currently can't be trusted.
914 Mention Privoxy-Log-Parser's --statistics option as
915 an alternative for the time being.
920 In rfc2553_connect_to(), start setting cgi->error_message on error.
925 Change the expected status code returned for http://p.p/die depending
926 on whether or not FEATURE_GRACEFUL_TERMINATION is available.
931 In cgi_die(), mark the client connection for closing.
932 If the client will fetch the style sheet through another connection
933 it gets the main thread out of the accept() state and should thus
934 trigger the actual shutdown.
939 Add a proper CGI message for cgi_die().
944 Don't enforce a logical line length limit in read_config_line().
949 Slightly refactor server_last_modified() to remove useless gmtime*() calls.
954 In get_content_type(), also recognize '.jpeg' as JPEG extension.
959 Add '.png' to the list of recognized file extensions in get_content_type().
964 In block_url(), consistently use the block reason "Request blocked by Privoxy"
965 In two places the reason was "Request for blocked URL" which hides the
966 fact that the request got blocked by Privoxy and isn't necessarily
967 correct as the block may be due to tags.
972 In listen_loop(), reload the configuration files after accepting
973 a new connection instead of before.
974 Previously the first connection that arrived after a configuration
975 change would still be handled with the old configuration.
980 In chat()'s receive-data loop, skip a client socket check if
981 the socket will be written to right away anyway. This can
982 increase the transfer speed for unfiltered content on fast
988 The socket timeout is used for SOCKS negotiations as well which
989 previously couldn't timeout.
994 Don't keep the client connection alive if any configuration file
995 changed since the time the connection came in. This is closer to
996 Privoxy's behaviour before keep-alive support for client connection
997 has been added and also less confusing in general.
1002 Treat all Content-Type header values containing the pattern
1003 'script' as a sign of text. Reported by pribog in #3134970.
1011 Action file improvements:
1015 Moved the site-specific block pattern section below the one for the
1016 generic patterns so for requests that are matched in both, the block
1017 reason for the domain is shown which is usually more useful than showing
1018 the one for the generic pattern.
1023 Remove -prevent-compression from the fragile alias. It's no longer
1024 used anywhere by default and isn't known to break stuff anyway.
1029 Add a (disabled) section to block various Facebook tracking URLs.
1030 Reported by Dan Stahlke in #3421764.
1035 Add a (disabled) section to rewrite and redirect click-tracking
1036 URLs used on news.google.com.
1037 Reported by Dan Stahlke in #3421755.
1042 Unblock linuxcounter.net/.
1043 Reported by Dan Stahlke in #3422612.
1048 Block 'www91.intel.com/' which is used by Omniture.
1049 Reported by Adam Piggott in #3167370.
1054 Disable the handle-as-empty-doc-returns-ok option and mark it as deprecated.
1055 Reminded by tceverling in #2790091.
1060 Add ".ivwbox.de/" to the "Cross-site user tracking" section.
1061 Reported by Nettozahler in #3172525.
1066 Unblock and fast-redirect ".awin1.com/.*=http://".
1067 Reported by Adam Piggott in #3170921.
1072 Block "b.collective-media.net/".
1077 Widen the Debian popcon exception to "qa.debian.org/popcon".
1078 Seen in Debian's 05_default_action.dpatch by Roland Rosenfeld.
1083 Block ".gemius.pl/" which only seems to be used for user tracking.
1084 Reported by johnd16 in #3002731. Additional input from Lee and movax.
1089 Disable banners-by-size filters for '.thinkgeek.com/'.
1090 The filter only seems to catch pictures of the inventory.
1095 Block requests for 'go.idmnet.bbelements.com/please/showit/'.
1096 Reported by kacperdominik in #3372959.
1101 Unblock adainitiative.org/.
1106 Add a fast-redirects exception for '.googleusercontent.com/.*=cache'.
1111 Add a fast-redirects exception for webcache.googleusercontent.com/.
1116 Unblock http://adassier.wordpress.com/ and http://adassier.files.wordpress.com/.
1124 Filter file improvements:
1128 Let the yahoo filter hide '.ads'.
1133 Let the msn filter hide overlay ads for Facebook 'likes' in search
1134 results and elements with the id 's_notf_div'. They only seem to be
1135 used to advertise site 'enhancements'.
1140 Let the js-events filter additionally disarm setInterval().
1141 Suggested by dg1727 in #3423775.
1149 Documentation improvements:
1153 Clarify the effect of compiling Privoxy with zlib support.
1154 Suggested by dg1727 in #3423782.
1159 Point out that the SourceForge messaging system works like a black
1160 hole and should thus not be used to contact individual developers.
1165 Mention some of the problems one can experience when not explicitly
1166 configuring an IP addresses as listen address.
1171 Explicitly mention that hostnames can be used instead of IP addresses
1172 for the listen-address, that only the first address returned will be
1173 used and what happens if the address is invalid.
1174 Requested by Calestyo in #3302213.
1182 Log message improvements:
1186 If only the server connection is kept alive, do not pretend to
1187 wait for a new client request.
1192 Remove a superfluous log message in forget_connection().
1197 In chat(), properly report missing server responses as such
1198 instead of calling them empty.
1203 In forwarded_connect(), fix a log message nobody should ever see.
1208 Fix a log message in socks5_connect(), a failed write operation
1209 was logged as failed read operation.
1214 Let load_one_actions_file() properly complain about a missing
1215 '{' at the beginning of the file.
1216 Simply stating that a line is invalid isn't particularly helpful.
1221 Do not claim to listen on a socket until Privoxy actually does.
1222 Patch submitted by Petr Pisar #3354485
1227 Prevent a duplicated LOG_LEVEL_CLF message when sending out
1228 the "no-server-data" response.
1233 Also log the client socket when dropping a connection.
1238 Include the destination host in the 'Request ... marked for
1239 blocking. limit-connect{...} doesn't allow CONNECT ...' message
1240 Patch submitted by Saperski in #3296250.
1245 Prevent a duplicated log message if none of the resolved IP
1246 addresses were reachable.
1251 In connect_to(), do not pretend to retry if forwarded-connect-retries
1257 When a specified user or group can't be found, put the name in
1258 single-quotes when logging it.
1263 In rfc2553_connect_to(), explain getnameinfo() errors better.
1268 Remove a useless log message in chat().
1273 When retrying to connect, also log the maximum number of connection
1279 Rephrase a log message in compile_dynamic_pcrs_job_list().
1280 Divide the error code and its meaning with a colon. Call the pcrs
1281 job dynamic and not the filter. Filters may contain dynamic and
1282 non-dynamic pcrs jobs at the same time. Only mention the name of
1283 the filter or tagger, but don't claim it's a filter when it could
1289 In a fatal error message in load_one_actions_file(), cover both
1290 URL and TAG patterns.
1295 In pcrs_strerror(), properly report unknown positive error code
1296 values as such. Previously they were handled like 0 (no error).
1301 In compile_dynamic_pcrs_job_list(), also log the actual error code as
1302 pcrs_strerror() doesn't handle all errors reported by pcre.
1307 Don't bother trying to continue chatting if the client didn't ask for it.
1308 Reduces log noise a bit.
1313 Make two fatal error message in load_one_actions_file() more descriptive.
1318 In cgi_send_user_manual(), log when rejecting a file name due to '/' or '..'.
1323 In load_file(), log a message if opening a file failed.
1324 The CGI error message alone isn't too helpful.
1329 In connection_destination_matches(), improve two log messages
1330 to help understand why the destinations don't match.
1335 Rephrase a log message in serve(). Client request arrival
1336 should be differentiated from closed client connections now.
1341 In serve(), log if a client connection isn't reused due to a
1342 configuration file change.
1347 Let mark_server_socket_tainted() always mark the server socket tainted,
1348 just don't talk about it in cases where it has no effect. It doesn't change
1349 Privoxy's behaviour, but makes understanding the log file easier.
1361 Added a --disable-ipv6-support switch for platforms where support
1362 is detected but doesn't actually work.
1367 Do not check for the existence of strerror() and memmove() twice
1372 Remove a useless test for setpgrp(2). Privoxy doesn't need it and
1373 it can cause problems when cross-compiling.
1378 Rename the --disable-acl-files switch to --disable-acl-support.
1379 Since about 2001, ACL directives are specified in the standard
1385 Update the URL of the 'Removing outdated PCRE version after the
1386 next stable release' posting. The old URL stopped working after
1387 one of SF's recent site "optimizations". Reported by Han Liu.
1395 Privoxy-Regression-Test:
1399 Added --shuffle-tests option to increase the chances of detection race conditions.
1404 Added a --local-test-file option that allows to use Privoxy-Regression-Test without Privoxy.
1409 Added tests for missing socks4 and socks4a forwarders.
1414 The --privoxy-address option now works with IPv6 addresses containing brackets, too.
1419 Perform limited sanity checks for parameters that are supposed to have numerical values.
1424 Added a --sleep-time option to specify a number of seconds to
1425 sleep between tests, defaults to 0.
1430 Disable the range-requests tagger for tests that break if it's enabled.
1435 Log messages use the ISO 8601 date format %Y-%m-%d.
1440 Fix spelling in two error messages.
1445 In the --help output, include a list of supported tests and their default levels.
1450 Adjust the tests to properly deal with FEATURE_TOGGLE being disabled.
1462 Perform limited sanity checks for command line parameters that
1463 are supposed to have numerical values.
1468 Implement a --unbreak-lines-only option to try to revert MUA breakage.
1473 Accept and highlight: Added header: Content-Encoding: deflate
1478 Accept and highlight: Compressed content from 29258 to 8630 bytes.
1483 Accept and highlight: Client request arrived in time on socket 21.
1488 Highlight: Didn't receive data in time: a.fsdn.com:443
1493 Accept log messages with ISO 8601 time stamps, too.
1505 Bump generated Firefox version to 8.0.
1510 Only randomize the release date if the new --randomize-release-date
1511 option is enabled. Firefox versions after 4 use a fixed date string
1522 <!-- ~~~~~ New section ~~~~~ -->
1524 <sect2 id="upgradersnote">
1525 <title>Note to Upgraders</title>
1528 A quick list of things to be aware of before upgrading from earlier
1529 versions of <application>Privoxy</application>:
1537 The recommended way to upgrade &my-app; is to backup your old
1538 configuration files, install the new ones, verify that &my-app;
1539 is working correctly and finally merge back your changes using
1540 <application>diff</application> and maybe <application>patch</application>.
1543 There are a number of new features in each &my-app; release and
1544 most of them have to be explicitly enabled in the configuration
1545 files. Old configuration files obviously don't do that and due
1546 to syntax changes using old configuration files with a new
1547 &my-app; isn't always possible anyway.
1552 Note that some installers remove earlier versions completely,
1553 including configuration files, therefore you should really save
1554 any important configuration files!
1559 On the other hand, other installers don't overwrite existing configuration
1560 files, thinking you will want to do that yourself.
1565 <filename>standard.action</filename> has been merged into
1566 the <filename>default.action</filename> file.
1571 In the default configuration only fatal errors are logged now.
1572 You can change that in the <link linkend="DEBUG">debug section</link>
1573 of the configuration file. You may also want to enable more verbose
1574 logging until you verified that the new &my-app; version is working
1581 Three other config file settings are now off by default:
1582 <link linkend="enable-remote-toggle">enable-remote-toggle</link>,
1583 <link linkend="enable-remote-http-toggle">enable-remote-http-toggle</link>,
1584 and <link linkend="enable-edit-actions">enable-edit-actions</link>.
1585 If you use or want these, you will need to explicitly enable them, and
1586 be aware of the security issues involved.
1593 What constitutes a <quote>default</quote> configuration has changed,
1594 and you may want to review which actions are <quote>on</quote> by
1595 default. This is primarily a matter of emphasis, but some features
1596 you may have been used to, may now be <quote>off</quote> by default.
1597 There are also a number of new actions and filters you may want to
1598 consider, most of which are not fully incorporated into the default
1599 settings as yet (see above).
1606 The default actions setting is now <literal>Cautious</literal>. Previous
1607 releases had a default setting of <literal>Medium</literal>. Experienced
1608 users may want to adjust this, as it is fairly conservative by &my-app;
1609 standards and past practices. See <ulink
1610 url="http://config.privoxy.org/edit-actions-list?f=default">
1611 http://config.privoxy.org/edit-actions-list?f=default</ulink>. New users
1612 should try the default settings for a while before turning up the volume.
1618 The default setting has filtering turned <emphasis>off</emphasis>, which
1619 subsequently means that compression is <emphasis>on</emphasis>. Remember
1620 that filtering does not work on compressed pages, so if you use, or want to
1621 use, filtering, you will need to force compression off. Example:
1625 { +<link linkend="filter">filter</link>{google} +<link linkend="prevent-compression">prevent-compression</link> }
1629 Or if you use a number of filters, or filter many sites, you may just want
1630 to turn off compression for all sites in
1631 <filename>default.action</filename> (or
1632 <filename>user.action</filename>).
1639 Also, <link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> is
1640 off by default now. If you've liked this feature in the past, you may want
1641 to turn it back on in <filename>user.action</filename> now.
1648 Some installers may not automatically start
1649 <application>Privoxy</application> after installation.
1660 <!-- ~~~~~ New section ~~~~~ -->
1661 <sect1 id="quickstart"><title>Quickstart to Using Privoxy</title>
1667 Install <application>Privoxy</application>. See the <link
1668 linkend="installation">Installation Section</link> below for platform specific
1675 Advanced users and those who want to offer <application>Privoxy</application>
1676 service to more than just their local machine should check the <link
1677 linkend="config">main config file</link>, especially the <link
1678 linkend="access-control">security-relevant</link> options. These are
1685 Start <application>Privoxy</application>, if the installation program has
1686 not done this already (may vary according to platform). See the section
1687 <link linkend="startup">Starting <application>Privoxy</application></link>.
1693 Set your browser to use <application>Privoxy</application> as HTTP and
1694 HTTPS (SSL) <ulink url="http://en.wikipedia.org/wiki/Proxy_server">proxy</ulink>
1695 by setting the proxy configuration for address of
1696 <literal>127.0.0.1</literal> and port <literal>8118</literal>.
1697 <emphasis>DO NOT</emphasis> activate proxying for <literal>FTP</literal> or
1698 any protocols besides HTTP and HTTPS (SSL) unless you intend to prevent your
1699 browser from using these protocols.
1705 Flush your browser's disk and memory caches, to remove any cached ad images.
1706 If using <application>Privoxy</application> to manage
1707 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>,
1708 you should remove any currently stored cookies too.
1714 A default installation should provide a reasonable starting point for
1715 most. There will undoubtedly be occasions where you will want to adjust the
1716 configuration, but that can be dealt with as the need arises. Little
1717 to no initial configuration is required in most cases, you may want
1719 <ulink url="config.html#ENABLE-EDIT-ACTIONS">web-based action editor</ulink> though.
1720 Be sure to read the warnings first.
1723 See the <link linkend="configuration">Configuration section</link> for more
1724 configuration options, and how to customize your installation.
1725 You might also want to look at the <link
1726 linkend="quickstart-ad-blocking">next section</link> for a quick
1727 introduction to how <application>Privoxy</application> blocks ads and
1734 If you experience ads that slip through, innocent images that are
1735 blocked, or otherwise feel the need to fine-tune
1736 <application>Privoxy's</application> behavior, take a look at the <link
1737 linkend="actions-file">actions files</link>. As a quick start, you might
1738 find the <link linkend="act-examples">richly commented examples</link>
1739 helpful. You can also view and edit the actions files through the <ulink
1740 url="http://config.privoxy.org">web-based user interface</ulink>. The
1741 Appendix <quote><link linkend="actionsanat">Troubleshooting: Anatomy of an
1742 Action</link></quote> has hints on how to understand and debug actions that
1743 <quote>misbehave</quote>.
1748 Did anyone test these lately?
1752 For easy access to &my-app;'s most important controls, drag the provided
1753 <link linkend="bookmarklets">Bookmarklets</link> into your browser's
1761 Please see the section <link linkend="contact">Contacting the
1762 Developers</link> on how to report bugs, problems with websites or to get
1769 Now enjoy surfing with enhanced control, comfort and privacy!
1777 <!-- ~~~~~ New section ~~~~~ -->
1779 <sect2 id="quickstart-ad-blocking">
1780 <title>Quickstart to Ad Blocking</title>
1782 NOTE: This section is deliberately redundant for those that don't
1783 want to read the whole thing (which is getting lengthy).
1786 Ad blocking is but one of <application>Privoxy's</application>
1787 array of features. Many of these features are for the technically minded advanced
1788 user. But, ad and banner blocking is surely common ground for everybody.
1791 This section will provide a quick summary of ad blocking so
1792 you can get up to speed quickly without having to read the more extensive
1793 information provided below, though this is highly recommended.
1796 First a bit of a warning ... blocking ads is much like blocking SPAM: the
1797 more aggressive you are about it, the more likely you are to block
1798 things that were not intended. And the more likely that some things
1799 may not work as intended. So there is a trade off here. If you want
1800 extreme ad free browsing, be prepared to deal with more
1801 <quote>problem</quote> sites, and to spend more time adjusting the
1802 configuration to solve these unintended consequences. In short, there is
1803 not an easy way to eliminate <emphasis>all</emphasis> ads. Either take
1804 the easy way and settle for <emphasis>most</emphasis> ads blocked with the
1805 default configuration, or jump in and tweak it for your personal surfing
1806 habits and preferences.
1809 Secondly, a brief explanation of <application>Privoxy's </application>
1810 <quote>actions</quote>. <quote>Actions</quote> in this context, are
1811 the directives we use to tell <application>Privoxy</application> to perform
1812 some task relating to HTTP transactions (i.e. web browsing). We tell
1813 <application>Privoxy</application> to take some <quote>action</quote>. Each
1814 action has a unique name and function. While there are many potential
1815 <application>actions</application> in <application>Privoxy's</application>
1816 arsenal, only a few are used for ad blocking. <link
1817 linkend="actions">Actions</link>, and <link linkend="actions-file">action
1818 configuration files</link>, are explained in depth below.
1821 Actions are specified in <application>Privoxy's</application> configuration,
1822 followed by one or more URLs to which the action should apply. URLs
1823 can actually be URL type <link linkend="af-patterns">patterns</link> that use
1824 wildcards so they can apply potentially to a range of similar URLs. The
1825 actions, together with the URL patterns are called a section.
1828 When you connect to a website, the full URL will either match one or more
1829 of the sections as defined in <application>Privoxy's</application> configuration,
1830 or not. If so, then <application>Privoxy</application> will perform the
1831 respective actions. If not, then nothing special happens. Furthermore, web
1832 pages may contain embedded, secondary URLs that your web browser will
1833 use to load additional components of the page, as it parses the
1834 original page's HTML content. An ad image for instance, is just an URL
1835 embedded in the page somewhere. The image itself may be on the same server,
1836 or a server somewhere else on the Internet. Complex web pages will have many
1837 such embedded URLs. &my-app; can deal with each URL individually, so, for
1838 instance, the main page text is not touched, but images from such-and-such
1843 The most important actions for basic ad blocking are: <literal><link
1844 linkend="block">block</link></literal>, <literal><link
1845 linkend="handle-as-image">handle-as-image</link></literal>,
1847 linkend="handle-as-empty-document">handle-as-empty-document</link></literal>,and
1848 <literal><link linkend="set-image-blocker">set-image-blocker</link></literal>:
1856 <literal><link linkend="block">block</link></literal> - this is perhaps
1857 the single most used action, and is particularly important for ad blocking.
1858 This action stops any contact between your browser and any URL patterns
1859 that match this action's configuration. It can be used for blocking ads,
1860 but also anything that is determined to be unwanted. By itself, it simply
1861 stops any communication with the remote server and sends
1862 <application>Privoxy</application>'s own built-in BLOCKED page instead to
1863 let you now what has happened (with some exceptions, see below).
1869 <literal><link linkend="handle-as-image">handle-as-image</link></literal> -
1870 tells <application>Privoxy</application> to treat this URL as an image.
1871 <application>Privoxy</application>'s default configuration already does this
1872 for all common image types (e.g. GIF), but there are many situations where this
1873 is not so easy to determine. So we'll force it in these cases. This is particularly
1874 important for ad blocking, since only if we know that it's an image of
1875 some kind, can we replace it with an image of our choosing, instead of the
1876 <application>Privoxy</application> BLOCKED page (which would only result in
1877 a <quote>broken image</quote> icon). There are some limitations to this
1878 though. For instance, you can't just brute-force an image substitution for
1879 an entire HTML page in most situations.
1885 <literal><link linkend="handle-as-empty-document">handle-as-empty-document</link></literal> -
1886 sends an empty document instead of <application>Privoxy's</application>
1887 normal BLOCKED HTML page. This is useful for file types that are neither
1888 HTML nor images, such as blocking JavaScript files.
1895 linkend="set-image-blocker">set-image-blocker</link></literal> - tells
1896 <application>Privoxy</application> what to display in place of an ad image that
1897 has hit a block rule. For this to come into play, the URL must match a
1898 <literal><link linkend="block">block</link></literal> action somewhere in the
1899 configuration, <emphasis>and</emphasis>, it must also match an
1900 <literal><link linkend="handle-as-image">handle-as-image</link></literal> action.
1903 The configuration options on what to display instead of the ad are:
1907 <emphasis>pattern</emphasis> - a checkerboard pattern, so that an ad
1908 replacement is obvious. This is the default.
1913 <emphasis>blank</emphasis> - A very small empty GIF image is displayed.
1914 This is the so-called <quote>invisible</quote> configuration option.
1919 <emphasis>http://<URL></emphasis> - A redirect to any image anywhere
1920 of the user's choosing (advanced usage).
1929 Advanced users will eventually want to explore &my-app;
1930 <literal><link linkend="filter">filters</link></literal> as well. Filters
1931 are very different from <literal><link
1932 linkend="block">blocks</link></literal>.
1933 A <quote>block</quote> blocks a site, page, or unwanted contented. Filters
1934 are a way of filtering or modifying what is actually on the page. An example
1935 filter usage: a text replacement of <quote>no-no</quote> for
1936 <quote>nasty-word</quote>. That is a very simple example. This process can be
1937 used for ad blocking, but it is more in the realm of advanced usage and has
1938 some pitfalls to be wary off.
1942 The quickest way to adjust any of these settings is with your browser through
1943 the special <application>Privoxy</application> editor at <ulink
1944 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
1945 (shortcut: <ulink url="http://p.p/">http://p.p/show-status</ulink>). This
1946 is an internal page, and does not require Internet access.
1950 Note that as of <application>Privoxy</application> 3.0.7 beta the
1951 action editor is disabled by default. Check the
1952 <ulink url="config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions
1953 section in the configuration file</ulink> to learn why and in which
1954 cases it's safe to enable again.
1958 If you decided to enable the action editor, select the appropriate
1959 <quote>actions</quote> file, and click
1960 <quote><guibutton>Edit</guibutton></quote>. It is best to put personal or
1961 local preferences in <filename>user.action</filename> since this is not
1962 meant to be overwritten during upgrades, and will over-ride the settings in
1963 other files. Here you can insert new <quote>actions</quote>, and URLs for ad
1964 blocking or other purposes, and make other adjustments to the configuration.
1965 <application>Privoxy</application> will detect these changes automatically.
1969 A quick and simple step by step example:
1977 Right click on the ad image to be blocked, then select
1978 <quote><guimenuitem>Copy Link Location</guimenuitem></quote> from the
1986 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
1991 Find <filename>user.action</filename> in the top section, and click
1992 on <quote><guibutton>Edit</guibutton></quote>:
1995 <!-- image of editor and actions files selections -->
1997 <figure pgwide="0" float="0"><title>Actions Files in Use</title>
2000 <imagedata fileref="files-in-use.jpg" format="jpg">
2003 <phrase>[ Screenshot of Actions Files in Use ]</phrase>
2012 You should have a section with only
2013 <literal><link linkend="block">block</link></literal> listed under
2014 <quote>Actions:</quote>.
2015 If not, click a <quote><guibutton>Insert new section below</guibutton></quote>
2016 button, and in the new section that just appeared, click the
2017 <guibutton>Edit</guibutton> button right under the word <quote>Actions:</quote>.
2018 This will bring up a list of all actions. Find
2019 <literal><link linkend="block">block</link></literal> near the top, and click
2020 in the <quote>Enabled</quote> column, then <quote><guibutton>Submit</guibutton></quote>
2021 just below the list.
2026 Now, in the <literal><link linkend="block">block</link></literal> actions section,
2027 click the <quote><guibutton>Add</guibutton></quote> button, and paste the URL the
2028 browser got from <quote><guimenuitem>Copy Link Location</guimenuitem></quote>.
2029 Remove the <literal>http://</literal> at the beginning of the URL. Then, click
2030 <quote><guibutton>Submit</guibutton></quote> (or
2031 <quote><guibutton>OK</guibutton></quote> if in a pop-up window).
2036 Now go back to the original page, and press <keycap>SHIFT-Reload</keycap>
2037 (or flush all browser caches). The image should be gone now.
2045 This is a very crude and simple example. There might be good reasons to use a
2046 wildcard pattern match to include potentially similar images from the same
2047 site. For a more extensive explanation of <quote>patterns</quote>, and
2048 the entire actions concept, see <link linkend="actions-file">the Actions
2053 For advanced users who want to hand edit their config files, you might want
2054 to now go to the <link linkend="act-examples">Actions Files Tutorial</link>.
2055 The ideas explained therein also apply to the web-based editor.
2058 There are also various
2059 <link linkend="filter">filters</link> that can be used for ad blocking
2060 (filters are a special subset of actions). These
2061 fall into the <quote>advanced</quote> usage category, and are explained in
2062 depth in later sections.
2069 <!-- ~ End section ~ -->
2072 <!-- ~~~~~ New section ~~~~~ -->
2073 <sect1 id="startup">
2074 <title>Starting Privoxy</title>
2076 Before launching <application>Privoxy</application> for the first time, you
2077 will want to configure your browser(s) to use
2078 <application>Privoxy</application> as a HTTP and HTTPS (SSL)
2079 <ulink url="http://en.wikipedia.org/wiki/Proxy_server">proxy</ulink>. The default is
2080 127.0.0.1 (or localhost) for the proxy address, and port 8118 (earlier versions
2081 used port 8000). This is the one configuration step <emphasis>that must be done
2085 Please note that <application>Privoxy</application> can only proxy HTTP and
2086 HTTPS traffic. It will not work with FTP or other protocols.
2089 <!-- image of Mozilla Proxy configuration -->
2091 <figure pgwide="0" float="0"><title>Proxy Configuration Showing
2092 Mozilla/Netscape HTTP and HTTPS (SSL) Settings</title>
2095 <imagedata fileref="proxy_setup.jpg" format="jpg">
2098 <phrase>[ Screenshot of Mozilla Proxy Configuration ]</phrase>
2106 With <application>Firefox</application>, this is typically set under:
2110 <guibutton>Tools</guibutton> -> <guibutton>Options</guibutton> -> <guibutton>Advanced</guibutton> -> <guibutton>Network</guibutton> -><guibutton>Connection</guibutton> -> <guibutton>Settings</guibutton>
2115 Or optionally on some platforms:
2119 <guibutton>Edit</guibutton> -> <guibutton>Preferences</guibutton> -> <guibutton>General</guibutton> -> <guibutton>Connection Settings</guibutton> -> <guibutton>Manual Proxy Configuration</guibutton>
2125 With <application>Netscape</application> (and
2126 <application>Mozilla</application>), this can be set under:
2131 <!-- Mix ascii and gui art, something for everybody -->
2132 <!-- spacing on this is tricky -->
2133 <guibutton>Edit</guibutton> -> <guibutton>Preferences</guibutton> -> <guibutton>Advanced</guibutton> -> <guibutton>Proxies</guibutton> -> <guibutton>HTTP Proxy</guibutton>
2138 For <application>Internet Explorer v.5-7</application>:
2142 <guibutton>Tools</guibutton> -> <guibutton>Internet Options</guibutton> -> <guibutton>Connections</guibutton> -> <guibutton>LAN Settings</guibutton>
2146 Then, check <quote>Use Proxy</quote> and fill in the appropriate info
2147 (Address: 127.0.0.1, Port: 8118). Include HTTPS (SSL), if you want HTTPS
2148 proxy support too (sometimes labeled <quote>Secure</quote>). Make sure any
2149 checkboxes like <quote>Use the same proxy server for all protocols</quote> is
2150 <emphasis>UNCHECKED</emphasis>. You want only HTTP and HTTPS (SSL)!
2153 <!-- image of IE Proxy configuration -->
2155 <figure pgwide="0" float="0"><title>Proxy Configuration Showing
2156 Internet Explorer HTTP and HTTPS (Secure) Settings</title>
2159 <imagedata fileref="proxy2.jpg" format="jpg">
2162 <phrase>[ Screenshot of IE Proxy Configuration ]</phrase>
2170 After doing this, flush your browser's disk and memory caches to force a
2171 re-reading of all pages and to get rid of any ads that may be cached. Remove
2172 any <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>,
2173 if you want <application>Privoxy</application> to manage that. You are now
2174 ready to start enjoying the benefits of using
2175 <application>Privoxy</application>!
2179 <application>Privoxy</application> itself is typically started by specifying the
2180 main configuration file to be used on the command line. If no configuration
2181 file is specified on the command line, <application>Privoxy</application>
2182 will look for a file named <filename>config</filename> in the current
2183 directory. Except on Win32 where it will try <filename>config.txt</filename>.
2186 <sect2 id="start-redhat">
2187 <title>Red Hat and Fedora</title>
2189 A default Red Hat installation may not start &my-app; upon boot. It will use
2190 the file <filename>/etc/privoxy/config</filename> as its main configuration
2195 # /etc/rc.d/init.d/privoxy start
2203 # service privoxy start
2208 <sect2 id="start-debian">
2209 <title>Debian</title>
2211 We use a script. Note that Debian typically starts &my-app; upon booting per
2212 default. It will use the file
2213 <filename>/etc/privoxy/config</filename> as its main configuration
2218 # /etc/init.d/privoxy start
2223 <sect2 id="start-windows">
2224 <title>Windows</title>
2226 Click on the &my-app; Icon to start <application>Privoxy</application>. If no configuration file is
2227 specified on the command line, <application>Privoxy</application> will look
2228 for a file named <filename>config.txt</filename>. Note that Windows will
2229 automatically start &my-app; when the system starts if you chose that option
2233 <application>Privoxy</application> can run with full Windows service functionality.
2234 On Windows only, the &my-app; program has two new command line arguments
2235 to install and uninstall &my-app; as a service. See the
2236 <link linkend="installation-pack-win">Windows Installation
2237 instructions</link> for details.
2241 <sect2 id="start-unices">
2242 <title>Solaris, NetBSD, FreeBSD, HP-UX and others</title>
2244 Example Unix startup command:
2248 # /usr/sbin/privoxy /etc/privoxy/config
2253 <sect2 id="start-os2">
2256 During installation, <application>Privoxy</application> is configured to
2257 start automatically when the system restarts. You can start it manually by
2258 double-clicking on the <application>Privoxy</application> icon in the
2259 <application>Privoxy</application> folder.
2263 <sect2 id="start-macosx">
2264 <title>Mac OS X</title>
2266 After downloading the privoxy software, unzip the downloaded file by
2267 double-clicking on the zip file icon. Then, double-click on the
2268 installer package icon and follow the installation process.
2271 The privoxy service will automatically start after a successful
2272 installation. In addition, the privoxy service will automatically
2273 start every time your computer starts up.
2276 To prevent the privoxy service from automatically starting when your
2277 computer starts up, remove or rename the folder named
2278 /Library/StartupItems/Privoxy.
2281 A simple application named Privoxy Utility has been created which
2282 enables administrators to easily start and stop the privoxy service.
2285 In addition, the Privoxy Utility presents a simple way for
2286 administrators to edit the various privoxy config files. A method
2287 to uninstall the software is also available.
2290 An administrator username and password must be supplied in order for
2291 the Privoxy Utility to perform any of the tasks.
2296 <sect2 id="start-amigaos">
2297 <title>AmigaOS</title>
2299 Start <application>Privoxy</application> (with RUN <>NIL:) in your
2300 <filename>startnet</filename> script (AmiTCP), in
2301 <filename>s:user-startup</filename> (RoadShow), as startup program in your
2302 startup script (Genesis), or as startup action (Miami and MiamiDx).
2303 <application>Privoxy</application> will automatically quit when you quit your
2304 TCP/IP stack (just ignore the harmless warning your TCP/IP stack may display that
2305 <application>Privoxy</application> is still running).
2309 <sect2 id="start-gentoo">
2310 <title>Gentoo</title>
2312 A script is again used. It will use the file <filename>/etc/privoxy/config
2313 </filename> as its main configuration file.
2317 /etc/init.d/privoxy start
2321 Note that <application>Privoxy</application> is not automatically started at
2322 boot time by default. You can change this with the <literal>rc-update</literal>
2327 rc-update add privoxy default
2335 See the section <link linkend="cmdoptions">Command line options</link> for
2339 must find a better place for this paragraph
2342 The included default configuration files should give a reasonable starting
2343 point. Most of the per site configuration is done in the
2344 <ulink url="actions-file.html"><quote>actions</quote></ulink> files. These are
2345 where various cookie actions are defined, ad and banner blocking, and other
2346 aspects of <application>Privoxy</application> configuration. There are several
2347 such files included, with varying levels of aggressiveness.
2351 You will probably want to keep an eye out for sites for which you may prefer
2352 persistent cookies, and add these to your actions configuration as needed. By
2353 default, most of these will be accepted only during the current browser
2354 session (aka <quote>session cookies</quote>), unless you add them to the
2355 configuration. If you want the browser to handle this instead, you will need
2356 to edit <filename>user.action</filename> (or through the web based interface)
2357 and disable this feature. If you use more than one browser, it would make
2358 more sense to let <application>Privoxy</application> handle this. In which
2359 case, the browser(s) should be set to accept all cookies.
2363 Another feature where you will probably want to define exceptions for trusted
2364 sites is the popup-killing (through <ulink
2365 url="actions-file.html#FILTER-POPUPS"><quote>+filter{popups}</quote></ulink>),
2366 because your favorite shopping, banking, or leisure site may need
2367 popups (explained below).
2371 <application>Privoxy</application> does not support all of the optional HTTP/1.1
2372 features yet. In the unlikely event that you experience inexplicable problems
2373 with browsers that use HTTP/1.1 per default
2374 (like <application>Mozilla</application> or recent versions of I.E.), you might
2375 try to force HTTP/1.0 compatibility. For Mozilla, look under <literal>Edit ->
2376 Preferences -> Debug -> Networking</literal>.
2377 Alternatively, set the <quote>+downgrade-http-version</quote> config option in
2378 <filename>default.action</filename> which will downgrade your browser's HTTP
2379 requests from HTTP/1.1 to HTTP/1.0 before processing them.
2383 After running <application>Privoxy</application> for a while, you can
2384 start to fine tune the configuration to suit your personal, or site,
2385 preferences and requirements. There are many, many aspects that can
2386 be customized. <quote>Actions</quote>
2387 can be adjusted by pointing your browser to
2388 <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
2389 (shortcut: <ulink url="http://p.p/">http://p.p/</ulink>),
2390 and then follow the link to <quote>View & Change the Current Configuration</quote>.
2391 (This is an internal page and does not require Internet access.)
2395 In fact, various aspects of <application>Privoxy</application>
2396 configuration can be viewed from this page, including
2397 current configuration parameters, source code version numbers,
2398 the browser's request headers, and <quote>actions</quote> that apply
2399 to a given URL. In addition to the actions file
2400 editor mentioned above, <application>Privoxy</application> can also
2401 be turned <quote>on</quote> and <quote>off</quote> (toggled) from this page.
2405 If you encounter problems, try loading the page without
2406 <application>Privoxy</application>. If that helps, enter the URL where
2407 you have the problems into <ulink url="http://p.p/show-url-info">the browser
2408 based rule tracing utility</ulink>. See which rules apply and why, and
2409 then try turning them off for that site one after the other, until the problem
2410 is gone. When you have found the culprit, you might want to turn the rest on
2415 If the above paragraph sounds gibberish to you, you might want to <link
2416 linkend="actions-file">read more about the actions concept</link>
2417 or even dive deep into the <link linkend="actionsanat">Appendix
2422 If you can't get rid of the problem at all, think you've found a bug in
2423 Privoxy, want to propose a new feature or smarter rules, please see the
2424 section <link linkend="contact"><quote>Contacting the
2425 Developers</quote></link> below.
2430 <!-- ~~~~~ New section ~~~~~ -->
2431 <sect2 id="cmdoptions">
2432 <title>Command Line Options</title>
2434 <application>Privoxy</application> may be invoked with the following
2435 command-line options:
2443 <emphasis>--config-test</emphasis>
2446 Exit after loading the configuration files before binding to
2447 the listen address. The exit code signals whether or not the
2448 configuration files have been successfully loaded.
2451 If the exit code is 1, at least one of the configuration files
2452 is invalid, if it is 0, all the configuration files have been
2453 successfully loaded (but may still contain errors that can
2454 currently only be detected at run time).
2457 This option doesn't affect the log setting, combination with
2458 <emphasis>--no-daemon</emphasis> is recommended if a configured
2459 log file shouldn't be used.
2464 <emphasis>--version</emphasis>
2467 Print version info and exit. Unix only.
2472 <emphasis>--help</emphasis>
2475 Print short usage info and exit. Unix only.
2480 <emphasis>--no-daemon</emphasis>
2483 Don't become a daemon, i.e. don't fork and become process group
2484 leader, and don't detach from controlling tty. Unix only.
2489 <emphasis>--pidfile FILE</emphasis>
2492 On startup, write the process ID to <emphasis>FILE</emphasis>. Delete the
2493 <emphasis>FILE</emphasis> on exit. Failure to create or delete the
2494 <emphasis>FILE</emphasis> is non-fatal. If no <emphasis>FILE</emphasis>
2495 option is given, no PID file will be used. Unix only.
2500 <emphasis>--user USER[.GROUP]</emphasis>
2503 After (optionally) writing the PID file, assume the user ID of
2504 <emphasis>USER</emphasis>, and if included the GID of GROUP. Exit if the
2505 privileges are not sufficient to do so. Unix only.
2510 <emphasis>--chroot</emphasis>
2513 Before changing to the user ID given in the <emphasis>--user</emphasis> option,
2514 chroot to that user's home directory, i.e. make the kernel pretend to the &my-app;
2515 process that the directory tree starts there. If set up carefully, this can limit
2516 the impact of possible vulnerabilities in &my-app; to the files contained in that hierarchy.
2522 <emphasis>--pre-chroot-nslookup hostname</emphasis>
2525 Specifies a hostname to look up before doing a chroot. On some systems, initializing the
2526 resolver library involves reading config files from /etc and/or loading additional shared
2527 libraries from /lib. On these systems, doing a hostname lookup before the chroot reduces
2528 the number of files that must be copied into the chroot tree.
2531 For fastest startup speed, a good value is a hostname that is not in /etc/hosts but that
2532 your local name server (listed in /etc/resolv.conf) can resolve without recursion
2533 (that is, without having to ask any other name servers). The hostname need not exist,
2534 but if it doesn't, an error message (which can be ignored) will be output.
2540 <emphasis>configfile</emphasis>
2543 If no <emphasis>configfile</emphasis> is included on the command line,
2544 <application>Privoxy</application> will look for a file named
2545 <quote>config</quote> in the current directory (except on Win32
2546 where it will look for <quote>config.txt</quote> instead). Specify
2547 full path to avoid confusion. If no config file is found,
2548 <application>Privoxy</application> will fail to start.
2556 On <application>MS Windows</application> only there are two additional
2557 command-line options to allow <application>Privoxy</application> to install and
2558 run as a <emphasis>service</emphasis>. See the
2559 <link linkend="installation-pack-win">Window Installation section</link>
2567 <!-- ~ End section ~ -->
2570 <!-- ~~~~~ New section ~~~~~ -->
2571 <sect1 id="configuration"><title>Privoxy Configuration</title>
2573 All <application>Privoxy</application> configuration is stored
2574 in text files. These files can be edited with a text editor.
2575 Many important aspects of <application>Privoxy</application> can
2576 also be controlled easily with a web browser.
2580 <!-- ~~~~~ New section ~~~~~ -->
2583 <title>Controlling Privoxy with Your Web Browser</title>
2585 <application>Privoxy</application>'s user interface can be reached through the special
2586 URL <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
2587 (shortcut: <ulink url="http://p.p/">http://p.p/</ulink>),
2588 which is a built-in page and works without Internet access.
2589 You will see the following section:
2593 <!-- Needs to be put in a table and colorized -->
2596 <bridgehead renderas="sect2"> Privoxy Menu</bridgehead>
2600 ▪ <ulink url="http://config.privoxy.org/show-status">View & change the current configuration</ulink>
2603 ▪ <ulink url="http://config.privoxy.org/show-version">View the source code version numbers</ulink>
2606 ▪ <ulink url="http://config.privoxy.org/show-request">View the request headers.</ulink>
2609 ▪ <ulink url="http://config.privoxy.org/show-url-info">Look up which actions apply to a URL and why</ulink>
2612 ▪ <ulink url="http://config.privoxy.org/toggle">Toggle Privoxy on or off</ulink>
2615 ▪ <ulink
2616 url="http://www.privoxy.org/&p-version;/user-manual/">Documentation</ulink>
2624 This should be self-explanatory. Note the first item leads to an editor for the
2625 <link linkend="actions-file">actions files</link>, which is where the ad, banner,
2626 cookie, and URL blocking magic is configured as well as other advanced features of
2627 <application>Privoxy</application>. This is an easy way to adjust various
2628 aspects of <application>Privoxy</application> configuration. The actions
2629 file, and other configuration files, are explained in detail below.
2633 <quote>Toggle Privoxy On or Off</quote> is handy for sites that might
2634 have problems with your current actions and filters. You can in fact use
2635 it as a test to see whether it is <application>Privoxy</application>
2636 causing the problem or not. <application>Privoxy</application> continues
2637 to run as a proxy in this case, but all manipulation is disabled, i.e.
2638 <application>Privoxy</application> acts like a normal forwarding proxy. There
2639 is even a toggle <link linkend="bookmarklets">Bookmarklet</link> offered, so
2640 that you can toggle <application>Privoxy</application> with one click from
2645 Note that several of the features described above are disabled by default
2646 in <application>Privoxy</application> 3.0.7 beta and later.
2648 <ulink url="config.html">configuration file</ulink> to learn why
2649 and in which cases it's safe to enable them again.
2654 <!-- ~ End section ~ -->
2659 <!-- ~~~~~ New section ~~~~~ -->
2661 <sect2 id="confoverview">
2662 <title>Configuration Files Overview</title>
2664 For Unix, *BSD and Linux, all configuration files are located in
2665 <filename>/etc/privoxy/</filename> by default. For MS Windows, OS/2, and
2666 AmigaOS these are all in the same directory as the
2667 <application>Privoxy</application> executable. <![%p-not-stable;[ The name
2668 and number of configuration files has changed from previous versions, and is
2669 subject to change as development progresses.]]>
2673 The installed defaults provide a reasonable starting point, though
2674 some settings may be aggressive by some standards. For the time being, the
2675 principle configuration files are:
2683 The <link linkend="config">main configuration file</link> is named <filename>config</filename>
2684 on Linux, Unix, BSD, OS/2, and AmigaOS and <filename>config.txt</filename>
2685 on Windows. This is a required file.
2691 <filename>match-all.action</filename> is used to define which <quote>actions</quote>
2692 relating to banner-blocking, images, pop-ups, content modification, cookie handling
2693 etc should be applied by default. It should be the first actions file loaded.
2696 <filename>default.action</filename> defines many exceptions (both positive and negative)
2697 from the default set of actions that's configured in <filename>match-all.action</filename>.
2698 It should be the second actions file loaded and shouldn't be edited by the user.
2701 Multiple actions files may be defined in <filename>config</filename>. These
2702 are processed in the order they are defined. Local customizations and locally
2703 preferred exceptions to the default policies as defined in
2704 <filename>match-all.action</filename> (which you will most probably want
2705 to define sooner or later) are best applied in <filename>user.action</filename>,
2706 where you can preserve them across upgrades. The file isn't installed by all
2707 installers, but you can easily create it yourself with a text editor.
2710 There is also a web based editor that can be accessed from
2712 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
2714 url="http://p.p/show-status">http://p.p/show-status</ulink>) for the
2715 various actions files.
2721 <quote>Filter files</quote> (the <link linkend="filter-file">filter
2722 file</link>) can be used to re-write the raw page content, including
2723 viewable text as well as embedded HTML and JavaScript, and whatever else
2724 lurks on any given web page. The filtering jobs are only pre-defined here;
2725 whether to apply them or not is up to the actions files.
2726 <filename>default.filter</filename> includes various filters made
2727 available for use by the developers. Some are much more intrusive than
2728 others, and all should be used with caution. You may define additional
2729 filter files in <filename>config</filename> as you can with
2730 actions files. We suggest <filename>user.filter</filename> for any
2731 locally defined filters or customizations.
2739 The syntax of the configuration and filter files may change between different
2740 Privoxy versions, unfortunately some enhancements cost backwards compatibility.
2741 <!-- Add link to documentation-->
2745 All files use the <quote><literal>#</literal></quote> character to denote a
2746 comment (the rest of the line will be ignored) and understand line continuation
2747 through placing a backslash ("<literal>\</literal>") as the very last character
2748 in a line. If the <literal>#</literal> is preceded by a backslash, it looses
2749 its special function. Placing a <literal>#</literal> in front of an otherwise
2750 valid configuration line to prevent it from being interpreted is called "commenting
2751 out" that line. Blank lines are ignored.
2755 The actions files and filter files
2756 can use Perl style <link linkend="regex">regular expressions</link> for
2757 maximum flexibility.
2761 After making any changes, there is no need to restart
2762 <application>Privoxy</application> in order for the changes to take
2763 effect. <application>Privoxy</application> detects such changes
2764 automatically. Note, however, that it may take one or two additional
2765 requests for the change to take effect. When changing the listening address
2766 of <application>Privoxy</application>, these <quote>wake up</quote> requests
2767 must obviously be sent to the <emphasis>old</emphasis> listening address.
2772 While under development, the configuration content is subject to change.
2773 The below documentation may not be accurate by the time you read this.
2774 Also, what constitutes a <quote>default</quote> setting, may change, so
2775 please check all your configuration files on important issues.
2781 <!-- ~ End section ~ -->
2784 <!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
2786 <!-- **************************************************** -->
2787 <!-- Include config.sgml here -->
2788 <!-- This is where the entire config file is detailed. -->
2790 <!-- end include -->
2793 <!-- ~ End section ~ -->
2797 <!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
2799 <sect1 id="actions-file"><title>Actions Files</title>
2803 XXX: similar descriptions are in the Configuration Files sections.
2804 We should only describe them at one place.
2807 The actions files are used to define what <emphasis>actions</emphasis>
2808 <application>Privoxy</application> takes for which URLs, and thus determines
2809 how ad images, cookies and various other aspects of HTTP content and
2810 transactions are handled, and on which sites (or even parts thereof).
2811 There are a number of such actions, with a wide range of functionality.
2812 Each action does something a little different.
2813 These actions give us a veritable arsenal of tools with which to exert
2814 our control, preferences and independence. Actions can be combined so that
2815 their effects are aggregated when applied against a given set of URLs.
2819 are three action files included with <application>Privoxy</application> with
2826 <filename>match-all.action</filename> - is used to define which
2827 <quote>actions</quote> relating to banner-blocking, images, pop-ups,
2828 content modification, cookie handling etc should be applied by default.
2829 It should be the first actions file loaded
2834 <filename>default.action</filename> - defines many exceptions (both
2835 positive and negative) from the default set of actions that's configured
2836 in <filename>match-all.action</filename>. It is a set of rules that should
2837 work reasonably well as-is for most users. This file is only supposed to
2838 be edited by the developers. It should be the second actions file loaded.
2843 <filename>user.action</filename> - is intended to be for local site
2844 preferences and exceptions. As an example, if your ISP or your bank
2845 has specific requirements, and need special handling, this kind of
2846 thing should go here. This file will not be upgraded.
2851 <guibutton>Edit</guibutton> <guibutton>Set to Cautious</guibutton> <guibutton>Set to Medium</guibutton> <guibutton>Set to Advanced</guibutton>
2854 These have increasing levels of aggressiveness <emphasis>and have no
2855 influence on your browsing unless you select them explicitly in the
2856 editor</emphasis>. A default installation should be pre-set to
2857 <literal>Cautious</literal>. New users should try this for a while before
2858 adjusting the settings to more aggressive levels. The more aggressive
2859 the settings, then the more likelihood there is of problems such as sites
2860 not working as they should.
2863 The <guibutton>Edit</guibutton> button allows you to turn each
2864 action on/off individually for fine-tuning. The <guibutton>Cautious</guibutton>
2865 button changes the actions list to low/safe settings which will activate
2866 ad blocking and a minimal set of &my-app;'s features, and subsequently
2867 there will be less of a chance for accidental problems. The
2868 <guibutton>Medium</guibutton> button sets the list to a medium level of
2869 other features and a low level set of privacy features. The
2870 <guibutton>Advanced</guibutton> button sets the list to a high level of
2871 ad blocking and medium level of privacy. See the chart below. The latter
2872 three buttons over-ride any changes via with the
2873 <guibutton>Edit</guibutton> button. More fine-tuning can be done in the
2874 lower sections of this internal page.
2877 While the actions file editor allows to enable these settings in all
2878 actions files, they are only supposed to be enabled in the first one
2879 to make sure you don't unintentionally overrule earlier rules.
2882 The default profiles, and their associated actions, as pre-defined in
2883 <filename>default.action</filename> are:
2886 <table frame=all><title>Default Configurations</title>
2887 <tgroup cols=4 align=left colsep=1 rowsep=1>
2888 <colspec colname=c1>
2889 <colspec colname=c2>
2890 <colspec colname=c3>
2891 <colspec colname=c4>
2894 <entry>Feature</entry>
2895 <entry>Cautious</entry>
2896 <entry>Medium</entry>
2897 <entry>Advanced</entry>
2902 <!-- <entry>f1</entry> -->
2903 <!-- <entry>f2</entry> -->
2904 <!-- <entry>f3</entry> -->
2905 <!-- <entry>f4</entry> -->
2911 <entry>Ad-blocking Aggressiveness</entry>
2912 <entry>medium</entry>
2918 <entry>Ad-filtering by size</entry>
2925 <entry>Ad-filtering by link</entry>
2931 <entry>Pop-up killing</entry>
2932 <entry>blocks only</entry>
2933 <entry>blocks only</entry>
2934 <entry>blocks only</entry>
2938 <entry>Privacy Features</entry>
2940 <entry>medium</entry>
2941 <entry>medium/high</entry>
2945 <entry>Cookie handling</entry>
2947 <entry>session-only</entry>
2952 <entry>Referer forging</entry>
2959 <entry>GIF de-animation</entry>
2966 <entry>Fast redirects</entry>
2973 <entry>HTML taming</entry>
2980 <entry>JavaScript taming</entry>
2987 <entry>Web-bug killing</entry>
2994 <entry>Image tag reordering</entry>
3010 The list of actions files to be used are defined in the main configuration
3011 file, and are processed in the order they are defined (e.g.
3012 <filename>default.action</filename> is typically processed before
3013 <filename>user.action</filename>). The content of these can all be viewed and
3015 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>.
3016 The over-riding principle when applying actions, is that the last action that
3017 matches a given URL wins. The broadest, most general rules go first
3018 (defined in <filename>default.action</filename>),
3019 followed by any exceptions (typically also in
3020 <filename>default.action</filename>), which are then followed lastly by any
3021 local preferences (typically in <emphasis>user</emphasis><filename>.action</filename>).
3022 Generally, <filename>user.action</filename> has the last word.
3026 An actions file typically has multiple sections. If you want to use
3027 <quote>aliases</quote> in an actions file, you have to place the (optional)
3028 <link linkend="aliases">alias section</link> at the top of that file.
3029 Then comes the default set of rules which will apply universally to all
3030 sites and pages (be <emphasis>very careful</emphasis> with using such a
3031 universal set in <filename>user.action</filename> or any other actions file after
3032 <filename>default.action</filename>, because it will override the result
3033 from consulting any previous file). And then below that,
3034 exceptions to the defined universal policies. You can regard
3035 <filename>user.action</filename> as an appendix to <filename>default.action</filename>,
3036 with the advantage that it is a separate file, which makes preserving your
3037 personal settings across <application>Privoxy</application> upgrades easier.
3041 Actions can be used to block anything you want, including ads, banners, or
3042 just some obnoxious URL whose content you would rather not see. Cookies can be accepted
3043 or rejected, or accepted only during the current browser session (i.e. not
3044 written to disk), content can be modified, some JavaScripts tamed, user-tracking
3045 fooled, and much more. See below for a <link linkend="actions">complete list
3049 <!-- ~~~~~ New section ~~~~~ -->
3051 <title>Finding the Right Mix</title>
3053 Note that some <link linkend="actions">actions</link>, like cookie suppression
3054 or script disabling, may render some sites unusable that rely on these
3055 techniques to work properly. Finding the right mix of actions is not always easy and
3056 certainly a matter of personal taste. And, things can always change, requiring
3057 refinements in the configuration. In general, it can be said that the more
3058 <quote>aggressive</quote> your default settings (in the top section of the
3059 actions file) are, the more exceptions for <quote>trusted</quote> sites you
3060 will have to make later. If, for example, you want to crunch all cookies per
3061 default, you'll have to make exceptions from that rule for sites that you
3062 regularly use and that require cookies for actually useful purposes, like maybe
3063 your bank, favorite shop, or newspaper.
3067 We have tried to provide you with reasonable rules to start from in the
3068 distribution actions files. But there is no general rule of thumb on these
3069 things. There just are too many variables, and sites are constantly changing.
3070 Sooner or later you will want to change the rules (and read this chapter again :).
3074 <!-- ~~~~~ New section ~~~~~ -->
3076 <title>How to Edit</title>
3078 The easiest way to edit the actions files is with a browser by
3079 using our browser-based editor, which can be reached from <ulink
3080 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>.
3081 Note: the config file option <link
3082 linkend="enable-edit-actions">enable-edit-actions</link> must be enabled for
3083 this to work. The editor allows both fine-grained control over every single
3084 feature on a per-URL basis, and easy choosing from wholesale sets of defaults
3085 like <quote>Cautious</quote>, <quote>Medium</quote> or
3086 <quote>Advanced</quote>. Warning: the <quote>Advanced</quote> setting is more
3087 aggressive, and will be more likely to cause problems for some sites.
3088 Experienced users only!
3092 If you prefer plain text editing to GUIs, you can of course also directly edit the
3093 the actions files with your favorite text editor. Look at
3094 <filename>default.action</filename> which is richly commented with many
3100 <sect2 id="actions-apply">
3101 <title>How Actions are Applied to Requests</title>
3103 Actions files are divided into sections. There are special sections,
3104 like the <quote><link linkend="aliases">alias</link></quote> sections which will
3105 be discussed later. For now let's concentrate on regular sections: They have a
3106 heading line (often split up to multiple lines for readability) which consist
3107 of a list of actions, separated by whitespace and enclosed in curly braces.
3108 Below that, there is a list of URL and tag patterns, each on a separate line.
3112 To determine which actions apply to a request, the URL of the request is
3113 compared to all URL patterns in each <quote>action file</quote>.
3114 Every time it matches, the list of applicable actions for the request is
3115 incrementally updated, using the heading of the section in which the
3116 pattern is located. The same is done again for tags and tag patterns later on.
3120 If multiple applying sections set the same action differently,
3121 the last match wins. If not, the effects are aggregated.
3122 E.g. a URL might match a regular section with a heading line of <literal>{
3123 +<link linkend="handle-as-image">handle-as-image</link> }</literal>,
3124 then later another one with just <literal>{
3125 +<link linkend="block">block</link> }</literal>, resulting
3126 in <emphasis>both</emphasis> actions to apply. And there may well be
3127 cases where you will want to combine actions together. Such a section then
3133 { +<literal>handle-as-image</literal> +<literal>block{Banner ads.}</literal> }
3134 # Block these as if they were images. Send no block page.
3136 media.example.com/.*banners
3137 .example.com/images/ads/</screen>
3141 You can trace this process for URL patterns and any given URL by visiting <ulink
3142 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>.
3146 Examples and more detail on this is provided in the Appendix, <link linkend="ACTIONSANAT">
3147 Troubleshooting: Anatomy of an Action</link> section.
3151 <!-- ~~~~~ New section ~~~~~ -->
3152 <sect2 id="af-patterns">
3153 <title>Patterns</title>
3155 As mentioned, <application>Privoxy</application> uses <quote>patterns</quote>
3156 to determine what <emphasis>actions</emphasis> might apply to which sites and
3157 pages your browser attempts to access. These <quote>patterns</quote> use wild
3158 card type <emphasis>pattern</emphasis> matching to achieve a high degree of
3159 flexibility. This allows one expression to be expanded and potentially match
3160 against many similar patterns.
3164 Generally, an URL pattern has the form
3165 <literal><domain><port>/<path></literal>, where the
3166 <literal><domain></literal>, the <literal><port></literal>
3167 and the <literal><path></literal> are optional. (This is why the special
3168 <literal>/</literal> pattern matches all URLs). Note that the protocol
3169 portion of the URL pattern (e.g. <literal>http://</literal>) should
3170 <emphasis>not</emphasis> be included in the pattern. This is assumed already!
3173 The pattern matching syntax is different for the domain and path parts of
3174 the URL. The domain part uses a simple globbing type matching technique,
3175 while the path part uses more flexible
3176 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
3177 Expressions</quote></ulink> (POSIX 1003.2).
3180 The port part of a pattern is a decimal port number preceded by a colon
3181 (<literal>:</literal>). If the domain part contains a numerical IPv6 address,
3182 it has to be put into angle brackets
3183 (<literal><</literal>, <literal>></literal>).
3188 <term><literal>www.example.com/</literal></term>
3191 is a domain-only pattern and will match any request to <literal>www.example.com</literal>,
3192 regardless of which document on that server is requested. So ALL pages in
3193 this domain would be covered by the scope of this action. Note that a
3194 simple <literal>example.com</literal> is different and would NOT match.
3199 <term><literal>www.example.com</literal></term>
3202 means exactly the same. For domain-only patterns, the trailing <literal>/</literal> may
3208 <term><literal>www.example.com/index.html</literal></term>
3211 matches all the documents on <literal>www.example.com</literal>
3212 whose name starts with <literal>/index.html</literal>.
3217 <term><literal>www.example.com/index.html$</literal></term>
3220 matches only the single document <literal>/index.html</literal>
3221 on <literal>www.example.com</literal>.
3226 <term><literal>/index.html$</literal></term>
3229 matches the document <literal>/index.html</literal>, regardless of the domain,
3230 i.e. on <emphasis>any</emphasis> web server anywhere.
3235 <term><literal>/</literal></term>
3238 Matches any URL because there's no requirement for either the
3239 domain or the path to match anything.
3244 <term><literal>:8000/</literal></term>
3247 Matches any URL pointing to TCP port 8000.
3252 <term><literal><2001:db8::1>/</literal></term>
3255 Matches any URL with the host address <literal>2001:db8::1</literal>.
3256 (Note that the real URL uses plain brackets, not angle brackets.)
3261 <term><literal>index.html</literal></term>
3264 matches nothing, since it would be interpreted as a domain name and
3265 there is no top-level domain called <literal>.html</literal>. So its
3273 <!-- ~~~~~ New section ~~~~~ -->
3274 <sect3><title>The Domain Pattern</title>
3277 The matching of the domain part offers some flexible options: if the
3278 domain starts or ends with a dot, it becomes unanchored at that end.
3284 <term><literal>.example.com</literal></term>
3287 matches any domain with first-level domain <literal>com</literal>
3288 and second-level domain <literal>example</literal>.
3289 For example <literal>www.example.com</literal>,
3290 <literal>example.com</literal> and <literal>foo.bar.baz.example.com</literal>.
3291 Note that it wouldn't match if the second-level domain was <literal>another-example</literal>.
3296 <term><literal>www.</literal></term>
3299 matches any domain that <emphasis>STARTS</emphasis> with
3300 <literal>www.</literal> (It also matches the domain
3301 <literal>www</literal> but most of the time that doesn't matter.)
3306 <term><literal>.example.</literal></term>
3309 matches any domain that <emphasis>CONTAINS</emphasis> <literal>.example.</literal>.
3310 And, by the way, also included would be any files or documents that exist
3311 within that domain since no path limitations are specified. (Correctly
3312 speaking: It matches any FQDN that contains <literal>example</literal> as
3313 a domain.) This might be <literal>www.example.com</literal>,
3314 <literal>news.example.de</literal>, or
3315 <literal>www.example.net/cgi/testing.pl</literal> for instance. All these
3323 Additionally, there are wild-cards that you can use in the domain names
3324 themselves. These work similarly to shell globbing type wild-cards:
3325 <quote>*</quote> represents zero or more arbitrary characters (this is
3327 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
3328 Expression</quote></ulink> based syntax of <quote>.*</quote>),
3329 <quote>?</quote> represents any single character (this is equivalent to the
3330 regular expression syntax of a simple <quote>.</quote>), and you can define
3331 <quote>character classes</quote> in square brackets which is similar to
3332 the same regular expression technique. All of this can be freely mixed:
3337 <term><literal>ad*.example.com</literal></term>
3340 matches <quote>adserver.example.com</quote>,
3341 <quote>ads.example.com</quote>, etc but not <quote>sfads.example.com</quote>
3346 <term><literal>*ad*.example.com</literal></term>
3349 matches all of the above, and then some.
3354 <term><literal>.?pix.com</literal></term>
3357 matches <literal>www.ipix.com</literal>,
3358 <literal>pictures.epix.com</literal>, <literal>a.b.c.d.e.upix.com</literal> etc.
3363 <term><literal>www[1-9a-ez].example.c*</literal></term>
3366 matches <literal>www1.example.com</literal>,
3367 <literal>www4.example.cc</literal>, <literal>wwwd.example.cy</literal>,
3368 <literal>wwwz.example.com</literal> etc., but <emphasis>not</emphasis>
3369 <literal>wwww.example.com</literal>.
3376 While flexible, this is not the sophistication of full regular expression based syntax.
3381 <!-- ~ End section ~ -->
3384 <!-- ~~~~~ New section ~~~~~ -->
3385 <sect3><title>The Path Pattern</title>
3388 <application>Privoxy</application> uses <quote>modern</quote> POSIX 1003.2
3389 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
3390 Expressions</quote></ulink> for matching the path portion (after the slash),
3391 and is thus more flexible.
3395 There is an <link linkend="regex">Appendix</link> with a brief quick-start into regular
3396 expressions, you also might want to have a look at your operating system's documentation
3397 on regular expressions (try <literal>man re_format</literal>).
3401 Note that the path pattern is automatically left-anchored at the <quote>/</quote>,
3402 i.e. it matches as if it would start with a <quote>^</quote> (regular expression speak
3403 for the beginning of a line).
3407 Please also note that matching in the path is <emphasis>CASE INSENSITIVE</emphasis>
3408 by default, but you can switch to case sensitive at any point in the pattern by using the
3409 <quote>(?-i)</quote> switch: <literal>www.example.com/(?-i)PaTtErN.*</literal> will match
3410 only documents whose path starts with <literal>PaTtErN</literal> in
3411 <emphasis>exactly</emphasis> this capitalization.
3416 <term><literal>.example.com/.*</literal></term>
3419 Is equivalent to just <quote>.example.com</quote>, since any documents
3420 within that domain are matched with or without the <quote>.*</quote>
3421 regular expression. This is redundant
3426 <term><literal>.example.com/.*/index.html$</literal></term>
3429 Will match any page in the domain of <quote>example.com</quote> that is
3430 named <quote>index.html</quote>, and that is part of some path. For
3431 example, it matches <quote>www.example.com/testing/index.html</quote> but
3432 NOT <quote>www.example.com/index.html</quote> because the regular
3433 expression called for at least two <quote>/'s</quote>, thus the path
3434 requirement. It also would match
3435 <quote>www.example.com/testing/index_html</quote>, because of the
3436 special meta-character <quote>.</quote>.
3441 <term><literal>.example.com/(.*/)?index\.html$</literal></term>
3444 This regular expression is conditional so it will match any page
3445 named <quote>index.html</quote> regardless of path which in this case can
3446 have one or more <quote>/'s</quote>. And this one must contain exactly
3447 <quote>.html</quote> (but does not have to end with that!).
3452 <term><literal>.example.com/(.*/)(ads|banners?|junk)</literal></term>
3455 This regular expression will match any path of <quote>example.com</quote>
3456 that contains any of the words <quote>ads</quote>, <quote>banner</quote>,
3457 <quote>banners</quote> (because of the <quote>?</quote>) or <quote>junk</quote>.
3458 The path does not have to end in these words, just contain them.
3463 <term><literal>.example.com/(.*/)(ads|banners?|junk)/.*\.(jpe?g|gif|png)$</literal></term>
3466 This is very much the same as above, except now it must end in either
3467 <quote>.jpg</quote>, <quote>.jpeg</quote>, <quote>.gif</quote> or <quote>.png</quote>. So this
3468 one is limited to common image formats.
3475 There are many, many good examples to be found in <filename>default.action</filename>,
3476 and more tutorials below in <link linkend="regex">Appendix on regular expressions</link>.
3481 <!-- ~ End section ~ -->
3484 <!-- ~~~~~ New section ~~~~~ -->
3485 <sect3 id="tag-pattern"><title>The Tag Pattern</title>
3488 Tag patterns are used to change the applying actions based on the
3489 request's tags. Tags can be created with either the
3490 <link linkend="CLIENT-HEADER-TAGGER">client-header-tagger</link>
3491 or the <link linkend="SERVER-HEADER-TAGGER">server-header-tagger</link> action.
3495 Tag patterns have to start with <quote>TAG:</quote>, so &my-app;
3496 can tell them apart from URL patterns. Everything after the colon
3497 including white space, is interpreted as a regular expression with
3498 path pattern syntax, except that tag patterns aren't left-anchored
3499 automatically (&my-app; doesn't silently add a <quote>^</quote>,
3500 you have to do it yourself if you need it).
3504 To match all requests that are tagged with <quote>foo</quote>
3505 your pattern line should be <quote>TAG:^foo$</quote>,
3506 <quote>TAG:foo</quote> would work as well, but it would also
3507 match requests whose tags contain <quote>foo</quote> somewhere.
3508 <quote>TAG: foo</quote> wouldn't work as it requires white space.
3512 Sections can contain URL and tag patterns at the same time,
3513 but tag patterns are checked after the URL patterns and thus
3514 always overrule them, even if they are located before the URL patterns.
3518 Once a new tag is added, Privoxy checks right away if it's matched by one
3519 of the tag patterns and updates the action settings accordingly. As a result
3520 tags can be used to activate other tagger actions, as long as these other
3521 taggers look for headers that haven't already be parsed.
3525 For example you could tag client requests which use the
3526 <literal>POST</literal> method,
3527 then use this tag to activate another tagger that adds a tag if cookies
3528 are sent, and then use a block action based on the cookie tag. This allows
3529 the outcome of one action, to be input into a subsequent action. However if
3530 you'd reverse the position of the described taggers, and activated the
3531 method tagger based on the cookie tagger, no method tags would be created.
3532 The method tagger would look for the request line, but at the time
3533 the cookie tag is created, the request line has already been parsed.
3537 While this is a limitation you should be aware of, this kind of
3538 indirection is seldom needed anyway and even the example doesn't
3539 make too much sense.
3546 <!-- ~ End section ~ -->
3549 <!-- ~~~~~ New section ~~~~~ -->
3551 <sect2 id="actions">
3552 <title>Actions</title>
3554 All actions are disabled by default, until they are explicitly enabled
3555 somewhere in an actions file. Actions are turned on if preceded with a
3556 <quote>+</quote>, and turned off if preceded with a <quote>-</quote>. So a
3557 <literal>+action</literal> means <quote>do that action</quote>, e.g.
3558 <literal>+block</literal> means <quote>please block URLs that match the
3559 following patterns</quote>, and <literal>-block</literal> means <quote>don't
3560 block URLs that match the following patterns, even if <literal>+block</literal>
3561 previously applied.</quote>
3566 Again, actions are invoked by placing them on a line, enclosed in curly braces and
3567 separated by whitespace, like in
3568 <literal>{+some-action -some-other-action{some-parameter}}</literal>,
3569 followed by a list of URL patterns, one per line, to which they apply.
3570 Together, the actions line and the following pattern lines make up a section
3571 of the actions file.
3575 Actions fall into three categories:
3582 Boolean, i.e the action can only be <quote>enabled</quote> or
3583 <quote>disabled</quote>. Syntax:
3587 +<replaceable class="function">name</replaceable> # enable action <replaceable class="parameter">name</replaceable>
3588 -<replaceable class="function">name</replaceable> # disable action <replaceable class="parameter">name</replaceable></screen>
3591 Example: <literal>+handle-as-image</literal>
3598 Parameterized, where some value is required in order to enable this type of action.
3603 +<replaceable class="function">name</replaceable>{<replaceable class="parameter">param</replaceable>} # enable action and set parameter to <replaceable class="parameter">param</replaceable>,
3604 # overwriting parameter from previous match if necessary
3605 -<replaceable class="function">name</replaceable> # disable action. The parameter can be omitted</screen>
3608 Note that if the URL matches multiple positive forms of a parameterized action,
3609 the last match wins, i.e. the params from earlier matches are simply ignored.
3612 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>
3618 Multi-value. These look exactly like parameterized actions,
3619 but they behave differently: If the action applies multiple times to the
3620 same URL, but with different parameters, <emphasis>all</emphasis> the parameters
3621 from <emphasis>all</emphasis> matches are remembered. This is used for actions
3622 that can be executed for the same request repeatedly, like adding multiple
3623 headers, or filtering through multiple filters. Syntax:
3627 +<replaceable class="function">name</replaceable>{<replaceable class="parameter">param</replaceable>} # enable action and add <replaceable class="parameter">param</replaceable> to the list of parameters
3628 -<replaceable class="function">name</replaceable>{<replaceable class="parameter">param</replaceable>} # remove the parameter <replaceable class="parameter">param</replaceable> from the list of parameters
3629 # If it was the last one left, disable the action.
3630 <replaceable class="parameter">-name</replaceable> # disable this action completely and remove all parameters from the list</screen>
3633 Examples: <literal>+add-header{X-Fun-Header: Some text}</literal> and
3634 <literal>+filter{html-annoyances}</literal>
3642 If nothing is specified in any actions file, no <quote>actions</quote> are
3643 taken. So in this case <application>Privoxy</application> would just be a
3644 normal, non-blocking, non-filtering proxy. You must specifically enable the
3645 privacy and blocking features you need (although the provided default actions
3646 files will give a good starting point).
3650 Later defined action sections always over-ride earlier ones of the same type.
3651 So exceptions to any rules you make, should come in the latter part of the file (or
3652 in a file that is processed later when using multiple actions files such
3653 as <filename>user.action</filename>). For multi-valued actions, the actions
3654 are applied in the order they are specified. Actions files are processed in
3655 the order they are defined in <filename>config</filename> (the default
3656 installation has three actions files). It also quite possible for any given
3657 URL to match more than one <quote>pattern</quote> (because of wildcards and
3658 regular expressions), and thus to trigger more than one set of actions! Last
3662 <!-- start actions listing -->
3664 The list of valid <application>Privoxy</application> actions are:
3668 <!-- ********************************************************** -->
3669 <!-- Please note the below defined actions use id's that are -->
3670 <!-- probably linked from other places, so please don't change. -->
3672 <!-- ********************************************************** -->
3675 <!-- ~~~~~ New section ~~~~~ -->
3677 <sect3 renderas="sect4" id="add-header">
3678 <title>add-header</title>
3682 <term>Typical use:</term>
3684 <para>Confuse log analysis, custom applications</para>
3689 <term>Effect:</term>
3692 Sends a user defined HTTP header to the web server.
3699 <!-- boolean, parameterized, Multi-value -->
3701 <para>Multi-value.</para>
3706 <term>Parameter:</term>
3709 Any string value is possible. Validity of the defined HTTP headers is not checked.
3710 It is recommended that you use the <quote><literal>X-</literal></quote> prefix
3720 This action may be specified multiple times, in order to define multiple
3721 headers. This is rarely needed for the typical user. If you don't know what
3722 <quote>HTTP headers</quote> are, you definitely don't need to worry about this
3726 Headers added by this action are not modified by other actions.
3732 <term>Example usage:</term>
3735 <screen>+add-header{X-User-Tracking: sucks}</screen>
3743 <!-- ~~~~~ New section ~~~~~ -->
3744 <sect3 renderas="sect4" id="block">
3745 <title>block</title>
3749 <term>Typical use:</term>
3751 <para>Block ads or other unwanted content</para>
3756 <term>Effect:</term>
3759 Requests for URLs to which this action applies are blocked, i.e. the
3760 requests are trapped by &my-app; and the requested URL is never retrieved,
3761 but is answered locally with a substitute page or image, as determined by
3763 linkend="handle-as-image">handle-as-image</link></literal>,
3765 linkend="set-image-blocker">set-image-blocker</link></literal>, and
3767 linkend="handle-as-empty-document">handle-as-empty-document</link></literal> actions.
3775 <!-- boolean, parameterized, Multi-value -->
3777 <para>Parameterized.</para>
3782 <term>Parameter:</term>
3784 <para>A block reason that should be given to the user.</para>
3792 <application>Privoxy</application> sends a special <quote>BLOCKED</quote> page
3793 for requests to blocked pages. This page contains the block reason given as
3794 parameter, a link to find out why the block action applies, and a click-through
3795 to the blocked content (the latter only if the force feature is available and
3799 A very important exception occurs if <emphasis>both</emphasis>
3800 <literal>block</literal> and <literal><link linkend="handle-as-image">handle-as-image</link></literal>,
3801 apply to the same request: it will then be replaced by an image. If
3802 <literal><link linkend="set-image-blocker">set-image-blocker</link></literal>
3803 (see below) also applies, the type of image will be determined by its parameter,
3804 if not, the standard checkerboard pattern is sent.
3807 It is important to understand this process, in order
3808 to understand how <application>Privoxy</application> deals with
3809 ads and other unwanted content. Blocking is a core feature, and one
3810 upon which various other features depend.
3813 The <literal><link linkend="filter">filter</link></literal>
3814 action can perform a very similar task, by <quote>blocking</quote>
3815 banner images and other content through rewriting the relevant URLs in the
3816 document's HTML source, so they don't get requested in the first place.
3817 Note that this is a totally different technique, and it's easy to confuse the two.
3823 <term>Example usage (section):</term>
3826 <screen>{+block{No nasty stuff for you.}}
3827 # Block and replace with "blocked" page
3828 .nasty-stuff.example.com
3830 {+block{Doubleclick banners.} +handle-as-image}
3831 # Block and replace with image
3835 {+block{Layered ads.} +handle-as-empty-document}
3836 # Block and then ignore
3837 adserver.example.net/.*\.js$</screen>
3847 <!-- ~~~~~ New section ~~~~~ -->
3848 <sect3 renderas="sect4" id="change-x-forwarded-for">
3849 <title>change-x-forwarded-for</title>
3853 <term>Typical use:</term>
3855 <para>Improve privacy by not forwarding the source of the request in the HTTP headers.</para>
3860 <term>Effect:</term>
3863 Deletes the <quote>X-Forwarded-For:</quote> HTTP header from the client request,
3871 <!-- Boolean, Parameterized, Multi-value -->
3873 <para>Parameterized.</para>
3878 <term>Parameter:</term>
3882 <para><quote>block</quote> to delete the header.</para>
3886 <quote>add</quote> to create the header (or append
3887 the client's IP address to an already existing one).
3898 It is safe and recommended to use <literal>block</literal>.
3901 Forwarding the source address of the request may make
3902 sense in some multi-user setups but is also a privacy risk.
3907 <term>Example usage:</term>
3910 <screen>+change-x-forwarded-for{block}</screen>
3917 <!-- ~~~~~ New section ~~~~~ -->
3918 <sect3 renderas="sect4" id="client-header-filter">
3919 <title>client-header-filter</title>
3923 <term>Typical use:</term>
3926 Rewrite or remove single client headers.
3932 <term>Effect:</term>
3935 All client headers to which this action applies are filtered on-the-fly through
3936 the specified regular expression based substitutions.
3943 <!-- boolean, parameterized, Multi-value -->
3945 <para>Parameterized.</para>
3950 <term>Parameter:</term>
3953 The name of a client-header filter, as defined in one of the
3954 <link linkend="filter-file">filter files</link>.
3963 Client-header filters are applied to each header on its own, not to
3964 all at once. This makes it easier to diagnose problems, but on the downside
3965 you can't write filters that only change header x if header y's value is z.
3966 You can do that by using tags though.
3969 Client-header filters are executed after the other header actions have finished
3970 and use their output as input.
3973 If the request URI gets changed, &my-app; will detect that and use the new
3974 one. This can be used to rewrite the request destination behind the client's
3975 back, for example to specify a Tor exit relay for certain requests.
3978 Please refer to the <link linkend="filter-file">filter file chapter</link>
3979 to learn which client-header filters are available by default, and how to
3987 <term>Example usage (section):</term>
3991 # Hide Tor exit notation in Host and Referer Headers
3992 {+client-header-filter{hide-tor-exit-notation}}
4003 <!-- ~~~~~ New section ~~~~~ -->
4004 <sect3 renderas="sect4" id="client-header-tagger">
4005 <title>client-header-tagger</title>
4009 <term>Typical use:</term>
4012 Block requests based on their headers.
4018 <term>Effect:</term>
4021 Client headers to which this action applies are filtered on-the-fly through
4022 the specified regular expression based substitutions, the result is used as
4030 <!-- boolean, parameterized, Multi-value -->
4032 <para>Parameterized.</para>
4037 <term>Parameter:</term>
4040 The name of a client-header tagger, as defined in one of the
4041 <link linkend="filter-file">filter files</link>.
4050 Client-header taggers are applied to each header on its own,
4051 and as the header isn't modified, each tagger <quote>sees</quote>
4055 Client-header taggers are the first actions that are executed
4056 and their tags can be used to control every other action.
4062 <term>Example usage (section):</term>
4066 # Tag every request with the User-Agent header
4067 {+client-header-tagger{user-agent}}
4070 # Tagging itself doesn't change the action
4071 # settings, sections with TAG patterns do:
4073 # If it's a download agent, use a different forwarding proxy,
4074 # show the real User-Agent and make sure resume works.
4075 {+forward-override{forward-socks5 10.0.0.2:2222 .} \
4076 -hide-if-modified-since \
4077 -overwrite-last-modified \
4082 TAG:^User-Agent: NetBSD-ftp/
4083 TAG:^User-Agent: Novell ZYPP Installer
4084 TAG:^User-Agent: RPM APT-HTTP/
4085 TAG:^User-Agent: fetch libfetch/
4086 TAG:^User-Agent: Ubuntu APT-HTTP/
4087 TAG:^User-Agent: MPlayer/
4092 # Tag all requests with the Range header set
4093 {+client-header-tagger{range-requests}}
4096 # Disable filtering for the tagged requests.
4098 # With filtering enabled Privoxy would remove the Range headers
4099 # to be able to filter the whole response. The downside is that
4100 # it prevents clients from resuming downloads or skipping over
4101 # parts of multimedia files.
4102 {-filter -deanimate-gifs}
4113 <!-- ~~~~~ New section ~~~~~ -->
4114 <sect3 renderas="sect4" id="content-type-overwrite">
4115 <title>content-type-overwrite</title>
4119 <term>Typical use:</term>
4121 <para>Stop useless download menus from popping up, or change the browser's rendering mode</para>
4126 <term>Effect:</term>
4129 Replaces the <quote>Content-Type:</quote> HTTP server header.
4136 <!-- Boolean, Parameterized, Multi-value -->
4138 <para>Parameterized.</para>
4143 <term>Parameter:</term>
4155 The <quote>Content-Type:</quote> HTTP server header is used by the
4156 browser to decide what to do with the document. The value of this
4157 header can cause the browser to open a download menu instead of
4158 displaying the document by itself, even if the document's format is
4159 supported by the browser.
4162 The declared content type can also affect which rendering mode
4163 the browser chooses. If XHTML is delivered as <quote>text/html</quote>,
4164 many browsers treat it as yet another broken HTML document.
4165 If it is send as <quote>application/xml</quote>, browsers with
4166 XHTML support will only display it, if the syntax is correct.
4169 If you see a web site that proudly uses XHTML buttons, but sets
4170 <quote>Content-Type: text/html</quote>, you can use &my-app;
4171 to overwrite it with <quote>application/xml</quote> and validate
4172 the web master's claim inside your XHTML-supporting browser.
4173 If the syntax is incorrect, the browser will complain loudly.
4176 You can also go the opposite direction: if your browser prints
4177 error messages instead of rendering a document falsely declared
4178 as XHTML, you can overwrite the content type with
4179 <quote>text/html</quote> and have it rendered as broken HTML document.
4182 By default <literal>content-type-overwrite</literal> only replaces
4183 <quote>Content-Type:</quote> headers that look like some kind of text.
4184 If you want to overwrite it unconditionally, you have to combine it with
4185 <literal><link linkend="force-text-mode">force-text-mode</link></literal>.
4186 This limitation exists for a reason, think twice before circumventing it.
4189 Most of the time it's easier to replace this action with a custom
4190 <literal><link linkend="server-header-filter">server-header filter</link></literal>.
4191 It allows you to activate it for every document of a certain site and it will still
4192 only replace the content types you aimed at.
4195 Of course you can apply <literal>content-type-overwrite</literal>
4196 to a whole site and then make URL based exceptions, but it's a lot
4197 more work to get the same precision.
4203 <term>Example usage (sections):</term>
4206 <screen># Check if www.example.net/ really uses valid XHTML
4207 { +content-type-overwrite{application/xml} }
4210 # but leave the content type unmodified if the URL looks like a style sheet
4211 {-content-type-overwrite}
4212 www.example.net/.*\.css$
4213 www.example.net/.*style
4222 <!-- ~~~~~ New section ~~~~~ -->
4223 <sect3 renderas="sect4" id="crunch-client-header">
4227 <title>crunch-client-header</title>
4231 <term>Typical use:</term>
4233 <para>Remove a client header <application>Privoxy</application> has no dedicated action for.</para>
4238 <term>Effect:</term>
4241 Deletes every header sent by the client that contains the string the user supplied as parameter.
4248 <!-- Boolean, Parameterized, Multi-value -->
4250 <para>Parameterized.</para>
4255 <term>Parameter:</term>
4267 This action allows you to block client headers for which no dedicated
4268 <application>Privoxy</application> action exists.
4269 <application>Privoxy</application> will remove every client header that
4270 contains the string you supplied as parameter.
4273 Regular expressions are <emphasis>not supported</emphasis> and you can't
4274 use this action to block different headers in the same request, unless
4275 they contain the same string.
4278 <literal>crunch-client-header</literal> is only meant for quick tests.
4279 If you have to block several different headers, or only want to modify
4280 parts of them, you should use a
4281 <literal><link linkend="client-header-filter">client-header filter</link></literal>.
4285 Don't block any header without understanding the consequences.
4292 <term>Example usage (section):</term>
4295 <screen># Block the non-existent "Privacy-Violation:" client header
4296 { +crunch-client-header{Privacy-Violation:} }
4306 <!-- ~~~~~ New section ~~~~~ -->
4307 <sect3 renderas="sect4" id="crunch-if-none-match">
4308 <title>crunch-if-none-match</title>
4314 <term>Typical use:</term>
4316 <para>Prevent yet another way to track the user's steps between sessions.</para>
4321 <term>Effect:</term>
4324 Deletes the <quote>If-None-Match:</quote> HTTP client header.
4331 <!-- Boolean, Parameterized, Multi-value -->
4333 <para>Boolean.</para>
4338 <term>Parameter:</term>
4350 Removing the <quote>If-None-Match:</quote> HTTP client header
4351 is useful for filter testing, where you want to force a real
4352 reload instead of getting status code <quote>304</quote> which
4353 would cause the browser to use a cached copy of the page.
4356 It is also useful to make sure the header isn't used as a cookie
4357 replacement (unlikely but possible).
4360 Blocking the <quote>If-None-Match:</quote> header shouldn't cause any
4361 caching problems, as long as the <quote>If-Modified-Since:</quote> header
4362 isn't blocked or missing as well.
4365 It is recommended to use this action together with
4366 <literal><link linkend="hide-if-modified-since">hide-if-modified-since</link></literal>
4368 <literal><link linkend="overwrite-last-modified">overwrite-last-modified</link></literal>.
4374 <term>Example usage (section):</term>
4377 <screen># Let the browser revalidate cached documents but don't
4378 # allow the server to use the revalidation headers for user tracking.
4379 {+hide-if-modified-since{-60} \
4380 +overwrite-last-modified{randomize} \
4381 +crunch-if-none-match}
4390 <!-- ~~~~~ New section ~~~~~ -->
4391 <sect3 renderas="sect4" id="crunch-incoming-cookies">
4392 <title>crunch-incoming-cookies</title>
4396 <term>Typical use:</term>
4399 Prevent the web server from setting HTTP cookies on your system
4405 <term>Effect:</term>
4408 Deletes any <quote>Set-Cookie:</quote> HTTP headers from server replies.
4415 <!-- Boolean, Parameterized, Multi-value -->
4417 <para>Boolean.</para>
4422 <term>Parameter:</term>
4434 This action is only concerned with <emphasis>incoming</emphasis> HTTP cookies. For
4435 <emphasis>outgoing</emphasis> HTTP cookies, use
4436 <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal>.
4437 Use <emphasis>both</emphasis> to disable HTTP cookies completely.
4440 It makes <emphasis>no sense at all</emphasis> to use this action in conjunction
4441 with the <literal><link linkend="session-cookies-only">session-cookies-only</link></literal> action,
4442 since it would prevent the session cookies from being set. See also
4443 <literal><link linkend="filter-content-cookies">filter-content-cookies</link></literal>.
4449 <term>Example usage:</term>
4452 <screen>+crunch-incoming-cookies</screen>
4460 <!-- ~~~~~ New section ~~~~~ -->
4461 <sect3 renderas="sect4" id="crunch-server-header">
4462 <title>crunch-server-header</title>
4468 <term>Typical use:</term>
4470 <para>Remove a server header <application>Privoxy</application> has no dedicated action for.</para>
4475 <term>Effect:</term>
4478 Deletes every header sent by the server that contains the string the user supplied as parameter.
4485 <!-- Boolean, Parameterized, Multi-value -->
4487 <para>Parameterized.</para>
4492 <term>Parameter:</term>
4504 This action allows you to block server headers for which no dedicated
4505 <application>Privoxy</application> action exists. <application>Privoxy</application>
4506 will remove every server header that contains the string you supplied as parameter.
4509 Regular expressions are <emphasis>not supported</emphasis> and you can't
4510 use this action to block different headers in the same request, unless
4511 they contain the same string.
4514 <literal>crunch-server-header</literal> is only meant for quick tests.
4515 If you have to block several different headers, or only want to modify
4516 parts of them, you should use a custom
4517 <literal><link linkend="server-header-filter">server-header filter</link></literal>.
4521 Don't block any header without understanding the consequences.
4528 <term>Example usage (section):</term>
4531 <screen># Crunch server headers that try to prevent caching
4532 { +crunch-server-header{no-cache} }
4541 <!-- ~~~~~ New section ~~~~~ -->
4542 <sect3 renderas="sect4" id="crunch-outgoing-cookies">
4543 <title>crunch-outgoing-cookies</title>
4547 <term>Typical use:</term>
4550 Prevent the web server from reading any HTTP cookies from your system
4556 <term>Effect:</term>
4559 Deletes any <quote>Cookie:</quote> HTTP headers from client requests.
4566 <!-- Boolean, Parameterized, Multi-value -->
4568 <para>Boolean.</para>
4573 <term>Parameter:</term>
4585 This action is only concerned with <emphasis>outgoing</emphasis> HTTP cookies. For
4586 <emphasis>incoming</emphasis> HTTP cookies, use
4587 <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal>.
4588 Use <emphasis>both</emphasis> to disable HTTP cookies completely.
4591 It makes <emphasis>no sense at all</emphasis> to use this action in conjunction
4592 with the <literal><link linkend="session-cookies-only">session-cookies-only</link></literal> action,
4593 since it would prevent the session cookies from being read.
4599 <term>Example usage:</term>
4602 <screen>+crunch-outgoing-cookies</screen>
4611 <!-- ~~~~~ New section ~~~~~ -->
4612 <sect3 renderas="sect4" id="deanimate-gifs">
4613 <title>deanimate-gifs</title>
4617 <term>Typical use:</term>
4619 <para>Stop those annoying, distracting animated GIF images.</para>
4624 <term>Effect:</term>
4627 De-animate GIF animations, i.e. reduce them to their first or last image.
4634 <!-- boolean, parameterized, Multi-value -->
4636 <para>Parameterized.</para>
4641 <term>Parameter:</term>
4644 <quote>last</quote> or <quote>first</quote>
4653 This will also shrink the images considerably (in bytes, not pixels!). If
4654 the option <quote>first</quote> is given, the first frame of the animation
4655 is used as the replacement. If <quote>last</quote> is given, the last
4656 frame of the animation is used instead, which probably makes more sense for
4657 most banner animations, but also has the risk of not showing the entire
4658 last frame (if it is only a delta to an earlier frame).
4661 You can safely use this action with patterns that will also match non-GIF
4662 objects, because no attempt will be made at anything that doesn't look like
4669 <term>Example usage:</term>
4672 <screen>+deanimate-gifs{last}</screen>
4679 <!-- ~~~~~ New section ~~~~~ -->
4680 <sect3 renderas="sect4" id="downgrade-http-version">
4681 <title>downgrade-http-version</title>
4685 <term>Typical use:</term>
4687 <para>Work around (very rare) problems with HTTP/1.1</para>
4692 <term>Effect:</term>
4695 Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0.
4702 <!-- boolean, parameterized, Multi-value -->
4704 <para>Boolean.</para>
4709 <term>Parameter:</term>
4721 This is a left-over from the time when <application>Privoxy</application>
4722 didn't support important HTTP/1.1 features well. It is left here for the
4723 unlikely case that you experience HTTP/1.1-related problems with some server
4727 Note that enabling this action is only a workaround. It should not
4728 be enabled for sites that work without it. While it shouldn't break
4729 any pages, it has an (usually negative) performance impact.
4732 If you come across a site where enabling this action helps, please report it,
4733 so the cause of the problem can be analyzed. If the problem turns out to be
4734 caused by a bug in <application>Privoxy</application> it should be
4735 fixed so the following release works without the work around.
4741 <term>Example usage (section):</term>
4744 <screen>{+downgrade-http-version}
4745 problem-host.example.com</screen>
4753 <!-- ~~~~~ New section ~~~~~ -->
4754 <sect3 renderas="sect4" id="fast-redirects">
4755 <title>fast-redirects</title>
4759 <term>Typical use:</term>
4761 <para>Fool some click-tracking scripts and speed up indirect links.</para>
4766 <term>Effect:</term>
4769 Detects redirection URLs and redirects the browser without contacting
4770 the redirection server first.
4777 <!-- boolean, parameterized, Multi-value -->
4779 <para>Parameterized.</para>
4784 <term>Parameter:</term>
4789 <quote>simple-check</quote> to just search for the string <quote>http://</quote>
4790 to detect redirection URLs.
4795 <quote>check-decoded-url</quote> to decode URLs (if necessary) before searching
4796 for redirection URLs.
4807 Many sites, like yahoo.com, don't just link to other sites. Instead, they
4808 will link to some script on their own servers, giving the destination as a
4809 parameter, which will then redirect you to the final target. URLs
4810 resulting from this scheme typically look like:
4811 <quote>http://www.example.org/click-tracker.cgi?target=http%3a//www.example.net/</quote>.
4814 Sometimes, there are even multiple consecutive redirects encoded in the
4815 URL. These redirections via scripts make your web browsing more traceable,
4816 since the server from which you follow such a link can see where you go
4817 to. Apart from that, valuable bandwidth and time is wasted, while your
4818 browser asks the server for one redirect after the other. Plus, it feeds
4822 This feature is currently not very smart and is scheduled for improvement.
4823 If it is enabled by default, you will have to create some exceptions to
4824 this action. It can lead to failures in several ways:
4827 Not every URLs with other URLs as parameters is evil.
4828 Some sites offer a real service that requires this information to work.
4829 For example a validation service needs to know, which document to validate.
4830 <literal>fast-redirects</literal> assumes that every URL parameter that
4831 looks like another URL is a redirection target, and will always redirect to
4832 the last one. Most of the time the assumption is correct, but if it isn't,
4833 the user gets redirected anyway.
4836 Another failure occurs if the URL contains other parameters after the URL parameter.
4838 <quote>http://www.example.org/?redirect=http%3a//www.example.net/&foo=bar</quote>.
4839 contains the redirection URL <quote>http://www.example.net/</quote>,
4840 followed by another parameter. <literal>fast-redirects</literal> doesn't know that
4841 and will cause a redirect to <quote>http://www.example.net/&foo=bar</quote>.
4842 Depending on the target server configuration, the parameter will be silently ignored
4843 or lead to a <quote>page not found</quote> error. You can prevent this problem by
4844 first using the <literal><link linkend="redirect">redirect</link></literal> action
4845 to remove the last part of the URL, but it requires a little effort.
4848 To detect a redirection URL, <literal>fast-redirects</literal> only
4849 looks for the string <quote>http://</quote>, either in plain text
4850 (invalid but often used) or encoded as <quote>http%3a//</quote>.
4851 Some sites use their own URL encoding scheme, encrypt the address
4852 of the target server or replace it with a database id. In theses cases
4853 <literal>fast-redirects</literal> is fooled and the request reaches the
4854 redirection server where it probably gets logged.
4860 <term>Example usage:</term>
4864 { +fast-redirects{simple-check} }
4867 { +fast-redirects{check-decoded-url} }
4868 another.example.com/testing</screen>
4877 <!-- ~~~~~ New section ~~~~~ -->
4878 <sect3 renderas="sect4" id="filter">
4879 <title>filter</title>
4883 <term>Typical use:</term>
4885 <para>Get rid of HTML and JavaScript annoyances, banner advertisements (by size),
4886 do fun text replacements, add personalized effects, etc.</para>
4891 <term>Effect:</term>
4894 All instances of text-based type, most notably HTML and JavaScript, to which
4895 this action applies, can be filtered on-the-fly through the specified regular
4896 expression based substitutions. (Note: as of version 3.0.3 plain text documents
4897 are exempted from filtering, because web servers often use the
4898 <literal>text/plain</literal> MIME type for all files whose type they don't know.)
4905 <!-- boolean, parameterized, Multi-value -->
4907 <para>Parameterized.</para>
4912 <term>Parameter:</term>
4915 The name of a content filter, as defined in the <link linkend="filter-file">filter file</link>.
4916 Filters can be defined in one or more files as defined by the
4917 <literal><link linkend="filterfile">filterfile</link></literal>
4918 option in the <link linkend="config">config file</link>.
4919 <filename>default.filter</filename> is the collection of filters
4920 supplied by the developers. Locally defined filters should go
4921 in their own file, such as <filename>user.filter</filename>.
4924 When used in its negative form,
4925 and without parameters, <emphasis>all</emphasis> filtering is completely disabled.
4934 For your convenience, there are a number of pre-defined filters available
4935 in the distribution filter file that you can use. See the examples below for
4939 Filtering requires buffering the page content, which may appear to
4940 slow down page rendering since nothing is displayed until all content has
4941 passed the filters. (The total time until the page is completely rendered
4942 doesn't change much, but it may be perceived as slower since the page is
4943 not incrementally displayed.)
4944 This effect will be more noticeable on slower connections.
4947 <quote>Rolling your own</quote>
4948 filters requires a knowledge of
4949 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
4950 Expressions</quote></ulink> and
4951 <ulink url="http://en.wikipedia.org/wiki/Html"><quote>HTML</quote></ulink>.
4952 This is very powerful feature, and potentially very intrusive.
4953 Filters should be used with caution, and where an equivalent
4954 <quote>action</quote> is not available.
4957 The amount of data that can be filtered is limited to the
4958 <literal><link linkend="buffer-limit">buffer-limit</link></literal>
4959 option in the main <link linkend="config">config file</link>. The
4960 default is 4096 KB (4 Megs). Once this limit is exceeded, the buffered
4961 data, and all pending data, is passed through unfiltered.
4964 Inappropriate MIME types, such as zipped files, are not filtered at all.
4965 (Again, only text-based types except plain text). Encrypted SSL data
4966 (from HTTPS servers) cannot be filtered either, since this would violate
4967 the integrity of the secure transaction. In some situations it might
4968 be necessary to protect certain text, like source code, from filtering
4969 by defining appropriate <literal>-filter</literal> exceptions.
4972 Compressed content can't be filtered either, but if &my-app;
4973 is compiled with zlib support and a supported compression algorithm
4974 is used (gzip or deflate), &my-app; can first decompress the content
4978 If you use a &my-app; version without zlib support, but want filtering to work on
4979 as much documents as possible, even those that would normally be sent compressed,
4980 you must use the <literal><link linkend="prevent-compression">prevent-compression</link></literal>
4981 action in conjunction with <literal>filter</literal>.
4984 Content filtering can achieve some of the same effects as the
4985 <literal><link linkend="block">block</link></literal>
4986 action, i.e. it can be used to block ads and banners. But the mechanism
4987 works quite differently. One effective use, is to block ad banners
4988 based on their size (see below), since many of these seem to be somewhat
4992 <link linkend="contact">Feedback</link> with suggestions for new or
4993 improved filters is particularly welcome!
4996 The below list has only the names and a one-line description of each
4997 predefined filter. There are <link linkend="predefined-filters">more
4998 verbose explanations</link> of what these filters do in the <link
4999 linkend="filter-file">filter file chapter</link>.
5005 <term>Example usage (with filters from the distribution <filename>default.filter</filename> file).
5006 See <link linkend="PREDEFINED-FILTERS">the Predefined Filters section</link> for
5007 more explanation on each:</term>
5010 <anchor id="filter-js-annoyances">
5011 <screen>+filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse.</screen>
5014 <anchor id="filter-js-events">
5015 <screen>+filter{js-events} # Kill all JS event bindings and timers (Radically destructive! Only for extra nasty sites).</screen>
5018 <anchor id="filter-html-annoyances">
5019 <screen>+filter{html-annoyances} # Get rid of particularly annoying HTML abuse.</screen>
5022 <anchor id="filter-content-cookies">
5023 <screen>+filter{content-cookies} # Kill cookies that come in the HTML or JS content.</screen>
5026 <anchor id="filter-refresh-tags">
5027 <screen>+filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups).</screen>
5030 <anchor id="filter-unsolicited-popups">
5031 <screen>+filter{unsolicited-popups} # Disable only unsolicited pop-up windows. Useful if your browser lacks this ability.</screen>
5034 <anchor id="filter-all-popups">
5035 <screen>+filter{all-popups} # Kill all popups in JavaScript and HTML. Useful if your browser lacks this ability.</screen>
5038 <anchor id="filter-img-reorder">
5039 <screen>+filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective.</screen>
5042 <anchor id="filter-banners-by-size">
5043 <screen>+filter{banners-by-size} # Kill banners by size.</screen>
5046 <anchor id="filter-banners-by-link">
5047 <screen>+filter{banners-by-link} # Kill banners by their links to known clicktrackers.</screen>
5050 <anchor id="filter-webbugs">
5051 <screen>+filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking).</screen>
5054 <anchor id="filter-tiny-textforms">
5055 <screen>+filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap.</screen>
5058 <anchor id="filter-jumping-windows">
5059 <screen>+filter{jumping-windows} # Prevent windows from resizing and moving themselves.</screen>
5062 <anchor id="filter-frameset-borders">
5063 <screen>+filter{frameset-borders} # Give frames a border and make them resizable.</screen>
5066 <anchor id="filter-demoronizer">
5067 <screen>+filter{demoronizer} # Fix MS's non-standard use of standard charsets.</screen>
5070 <anchor id="filter-shockwave-flash">
5071 <screen>+filter{shockwave-flash} # Kill embedded Shockwave Flash objects.</screen>
5074 <anchor id="filter-quicktime-kioskmode">
5075 <screen>+filter{quicktime-kioskmode} # Make Quicktime movies saveable.</screen>
5078 <anchor id="filter-fun">
5079 <screen>+filter{fun} # Text replacements for subversive browsing fun!</screen>
5082 <anchor id="filter-crude-parental">
5083 <screen>+filter{crude-parental} # Crude parental filtering. Note that this filter doesn't work reliably.</screen>
5086 <anchor id="filter-ie-exploits">
5087 <screen>+filter{ie-exploits} # Disable some known Internet Explorer bug exploits.</screen>
5090 <anchor id="filter-site-specifics">
5091 <screen>+filter{site-specifics} # Cure for site-specific problems. Don't apply generally!</screen>
5094 <anchor id="filter-no-ping">
5095 <screen>+filter{no-ping} # Removes non-standard ping attributes in <a> and <area> tags.</screen>
5098 <anchor id="filter-google">
5099 <screen>+filter{google} # CSS-based block for Google text ads. Also removes a width limitation and the toolbar advertisement.</screen>
5102 <anchor id="filter-yahoo">
5103 <screen>+filter{yahoo} # CSS-based block for Yahoo text ads. Also removes a width limitation.</screen>
5106 <anchor id="filter-msn">
5107 <screen>+filter{msn} # CSS-based block for MSN text ads. Also removes tracking URLs and a width limitation.</screen>
5110 <anchor id="filter-blogspot">
5111 <screen>+filter{blogspot} # Cleans up some Blogspot blogs. Read the fine print before using this.</screen>
5119 <!-- ~~~~~ New section ~~~~~ -->
5120 <sect3 renderas="sect4" id="force-text-mode">
5121 <title>force-text-mode</title>
5127 <term>Typical use:</term>
5129 <para>Force <application>Privoxy</application> to treat a document as if it was in some kind of <emphasis>text</emphasis> format. </para>
5134 <term>Effect:</term>
5137 Declares a document as text, even if the <quote>Content-Type:</quote> isn't detected as such.
5144 <!-- Boolean, Parameterized, Multi-value -->
5146 <para>Boolean.</para>
5151 <term>Parameter:</term>
5163 As explained <literal><link linkend="filter">above</link></literal>,
5164 <application>Privoxy</application> tries to only filter files that are
5165 in some kind of text format. The same restrictions apply to
5166 <literal><link linkend="content-type-overwrite">content-type-overwrite</link></literal>.
5167 <literal>force-text-mode</literal> declares a document as text,
5168 without looking at the <quote>Content-Type:</quote> first.
5172 Think twice before activating this action. Filtering binary data
5173 with regular expressions can cause file damage.
5180 <term>Example usage:</term>
5193 <!-- ~~~~~ New section ~~~~~ -->
5194 <sect3 renderas="sect4" id="forward-override">
5195 <title>forward-override</title>
5201 <term>Typical use:</term>
5203 <para>Change the forwarding settings based on User-Agent or request origin</para>
5208 <term>Effect:</term>
5211 Overrules the forward directives in the configuration file.
5218 <!-- Boolean, Parameterized, Multi-value -->
5220 <para>Multi-value.</para>
5225 <term>Parameter:</term>
5229 <para><quote>forward .</quote> to use a direct connection without any additional proxies.</para>
5233 <quote>forward 127.0.0.1:8123</quote> to use the HTTP proxy listening at 127.0.0.1 port 8123.
5238 <quote>forward-socks4a 127.0.0.1:9050 .</quote> to use the socks4a proxy listening at
5239 127.0.0.1 port 9050. Replace <quote>forward-socks4a</quote> with <quote>forward-socks4</quote>
5240 to use a socks4 connection (with local DNS resolution) instead, use <quote>forward-socks5</quote>
5241 for socks5 connections (with remote DNS resolution).
5246 <quote>forward-socks4a 127.0.0.1:9050 proxy.example.org:8000</quote> to use the socks4a proxy
5247 listening at 127.0.0.1 port 9050 to reach the HTTP proxy listening at proxy.example.org port 8000.
5248 Replace <quote>forward-socks4a</quote> with <quote>forward-socks4</quote> to use a socks4 connection
5249 (with local DNS resolution) instead, use <quote>forward-socks5</quote>
5250 for socks5 connections (with remote DNS resolution).
5261 This action takes parameters similar to the
5262 <link linkend="forwarding">forward</link> directives in the configuration
5263 file, but without the URL pattern. It can be used as replacement, but normally it's only
5264 used in cases where matching based on the request URL isn't sufficient.
5268 Please read the description for the <link linkend="forwarding">forward</link> directives before
5269 using this action. Forwarding to the wrong people will reduce your privacy and increase the
5270 chances of man-in-the-middle attacks.
5273 If the ports are missing or invalid, default values will be used. This might change
5274 in the future and you shouldn't rely on it. Otherwise incorrect syntax causes Privoxy
5278 Use the <ulink url="http://config.privoxy.org/show-url-info">show-url-info CGI page</ulink>
5279 to verify that your forward settings do what you thought the do.
5286 <term>Example usage:</term>
5290 # Always use direct connections for requests previously tagged as
5291 # <quote>User-Agent: fetch libfetch/2.0</quote> and make sure
5292 # resuming downloads continues to work.
5293 # This way you can continue to use Tor for your normal browsing,
5294 # without overloading the Tor network with your FreeBSD ports updates
5295 # or downloads of bigger files like ISOs.
5296 # Note that HTTP headers are easy to fake and therefore their
5297 # values are as (un)trustworthy as your clients and users.
5298 {+forward-override{forward .} \
5299 -hide-if-modified-since \
5300 -overwrite-last-modified \
5302 TAG:^User-Agent: fetch libfetch/2\.0$
5311 <!-- ~~~~~ New section ~~~~~ -->
5312 <sect3 renderas="sect4" id="handle-as-empty-document">
5313 <title>handle-as-empty-document</title>
5319 <term>Typical use:</term>
5321 <para>Mark URLs that should be replaced by empty documents <emphasis>if they get blocked</emphasis></para>
5326 <term>Effect:</term>
5329 This action alone doesn't do anything noticeable. It just marks URLs.
5330 If the <literal><link linkend="block">block</link></literal> action <emphasis>also applies</emphasis>,
5331 the presence or absence of this mark decides whether an HTML <quote>BLOCKED</quote>
5332 page, or an empty document will be sent to the client as a substitute for the blocked content.
5333 The <emphasis>empty</emphasis> document isn't literally empty, but actually contains a single space.
5340 <!-- Boolean, Parameterized, Multi-value -->
5342 <para>Boolean.</para>
5347 <term>Parameter:</term>
5359 Some browsers complain about syntax errors if JavaScript documents
5360 are blocked with <application>Privoxy's</application>
5361 default HTML page; this option can be used to silence them.
5362 And of course this action can also be used to eliminate the &my-app;
5363 BLOCKED message in frames.
5366 The content type for the empty document can be specified with
5367 <literal><link linkend="content-type-overwrite">content-type-overwrite{}</link></literal>,
5368 but usually this isn't necessary.
5374 <term>Example usage:</term>
5377 <screen># Block all documents on example.org that end with ".js",
5378 # but send an empty document instead of the usual HTML message.
5379 {+block{Blocked JavaScript} +handle-as-empty-document}
5389 <!-- ~~~~~ New section ~~~~~ -->
5390 <sect3 renderas="sect4" id="handle-as-image">
5391 <title>handle-as-image</title>
5395 <term>Typical use:</term>
5397 <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>
5402 <term>Effect:</term>
5405 This action alone doesn't do anything noticeable. It just marks URLs as images.
5406 If the <literal><link linkend="block">block</link></literal> action <emphasis>also applies</emphasis>,
5407 the presence or absence of this mark decides whether an HTML <quote>blocked</quote>
5408 page, or a replacement image (as determined by the <literal><link
5409 linkend="set-image-blocker">set-image-blocker</link></literal> action) will be sent to the
5410 client as a substitute for the blocked content.
5417 <!-- Boolean, Parameterized, Multi-value -->
5419 <para>Boolean.</para>
5424 <term>Parameter:</term>
5436 The below generic example section is actually part of <filename>default.action</filename>.
5437 It marks all URLs with well-known image file name extensions as images and should
5441 Users will probably only want to use the handle-as-image action in conjunction with
5442 <literal><link linkend="block">block</link></literal>, to block sources of banners, whose URLs don't
5443 reflect the file type, like in the second example section.
5446 Note that you cannot treat HTML pages as images in most cases. For instance, (in-line) ad
5447 frames require an HTML page to be sent, or they won't display properly.
5448 Forcing <literal>handle-as-image</literal> in this situation will not replace the
5449 ad frame with an image, but lead to error messages.
5455 <term>Example usage (sections):</term>
5458 <screen># Generic image extensions:
5461 /.*\.(gif|jpg|jpeg|png|bmp|ico)$
5463 # These don't look like images, but they're banners and should be
5464 # blocked as images:
5466 {+block{Nasty banners.} +handle-as-image}
5467 nasty-banner-server.example.com/junk.cgi\?output=trash
5476 <!-- ~~~~~ New section ~~~~~ -->
5477 <sect3 renderas="sect4" id="hide-accept-language">
5478 <title>hide-accept-language</title>
5484 <term>Typical use:</term>
5486 <para>Pretend to use different language settings.</para>
5491 <term>Effect:</term>
5494 Deletes or replaces the <quote>Accept-Language:</quote> HTTP header in client requests.
5501 <!-- Boolean, Parameterized, Multi-value -->
5503 <para>Parameterized.</para>
5508 <term>Parameter:</term>
5511 Keyword: <quote>block</quote>, or any user defined value.
5520 Faking the browser's language settings can be useful to make a
5521 foreign User-Agent set with
5522 <literal><link linkend="hide-user-agent">hide-user-agent</link></literal>
5526 However some sites with content in different languages check the
5527 <quote>Accept-Language:</quote> to decide which one to take by default.
5528 Sometimes it isn't possible to later switch to another language without
5529 changing the <quote>Accept-Language:</quote> header first.
5532 Therefore it's a good idea to either only change the
5533 <quote>Accept-Language:</quote> header to languages you understand,
5534 or to languages that aren't wide spread.
5537 Before setting the <quote>Accept-Language:</quote> header
5538 to a rare language, you should consider that it helps to
5539 make your requests unique and thus easier to trace.
5540 If you don't plan to change this header frequently,
5541 you should stick to a common language.
5547 <term>Example usage (section):</term>
5550 <screen># Pretend to use Canadian language settings.
5551 {+hide-accept-language{en-ca} \
5552 +hide-user-agent{Mozilla/5.0 (X11; U; OpenBSD i386; en-CA; rv:1.8.0.4) Gecko/20060628 Firefox/1.5.0.4} \
5562 <!-- ~~~~~ New section ~~~~~ -->
5563 <sect3 renderas="sect4" id="hide-content-disposition">
5564 <title>hide-content-disposition</title>
5570 <term>Typical use:</term>
5572 <para>Prevent download menus for content you prefer to view inside the browser.</para>
5577 <term>Effect:</term>
5580 Deletes or replaces the <quote>Content-Disposition:</quote> HTTP header set by some servers.
5587 <!-- Boolean, Parameterized, Multi-value -->
5589 <para>Parameterized.</para>
5594 <term>Parameter:</term>
5597 Keyword: <quote>block</quote>, or any user defined value.
5606 Some servers set the <quote>Content-Disposition:</quote> HTTP header for
5607 documents they assume you want to save locally before viewing them.
5608 The <quote>Content-Disposition:</quote> header contains the file name
5609 the browser is supposed to use by default.
5612 In most browsers that understand this header, it makes it impossible to
5613 <emphasis>just view</emphasis> the document, without downloading it first,
5614 even if it's just a simple text file or an image.
5617 Removing the <quote>Content-Disposition:</quote> header helps
5618 to prevent this annoyance, but some browsers additionally check the
5619 <quote>Content-Type:</quote> header, before they decide if they can
5620 display a document without saving it first. In these cases, you have
5621 to change this header as well, before the browser stops displaying
5625 It is also possible to change the server's file name suggestion
5626 to another one, but in most cases it isn't worth the time to set
5630 This action will probably be removed in the future,
5631 use server-header filters instead.
5637 <term>Example usage:</term>
5640 <screen># Disarm the download link in Sourceforge's patch tracker
5642 +content-type-overwrite{text/plain}\
5643 +hide-content-disposition{block} }
5644 .sourceforge.net/tracker/download\.php</screen>
5652 <!-- ~~~~~ New section ~~~~~ -->
5653 <sect3 renderas="sect4" id="hide-if-modified-since">
5654 <title>hide-if-modified-since</title>
5660 <term>Typical use:</term>
5662 <para>Prevent yet another way to track the user's steps between sessions.</para>
5667 <term>Effect:</term>
5670 Deletes the <quote>If-Modified-Since:</quote> HTTP client header or modifies its value.
5677 <!-- Boolean, Parameterized, Multi-value -->
5679 <para>Parameterized.</para>
5684 <term>Parameter:</term>
5687 Keyword: <quote>block</quote>, or a user defined value that specifies a range of hours.
5696 Removing this header is useful for filter testing, where you want to force a real
5697 reload instead of getting status code <quote>304</quote>, which would cause the
5698 browser to use a cached copy of the page.
5701 Instead of removing the header, <literal>hide-if-modified-since</literal> can
5702 also add or subtract a random amount of time to/from the header's value.
5703 You specify a range of minutes where the random factor should be chosen from and
5704 <application>Privoxy</application> does the rest. A negative value means
5705 subtracting, a positive value adding.
5708 Randomizing the value of the <quote>If-Modified-Since:</quote> makes
5709 it less likely that the server can use the time as a cookie replacement,
5710 but you will run into caching problems if the random range is too high.
5713 It is a good idea to only use a small negative value and let
5714 <literal><link linkend="overwrite-last-modified">overwrite-last-modified</link></literal>
5715 handle the greater changes.
5718 It is also recommended to use this action together with
5719 <literal><link linkend="crunch-if-none-match">crunch-if-none-match</link></literal>,
5720 otherwise it's more or less pointless.
5726 <term>Example usage (section):</term>
5729 <screen># Let the browser revalidate but make tracking based on the time less likely.
5730 {+hide-if-modified-since{-60} \
5731 +overwrite-last-modified{randomize} \
5732 +crunch-if-none-match}
5741 <!-- ~~~~~ New section ~~~~~ -->
5742 <sect3 renderas="sect4" id="hide-from-header">
5743 <title>hide-from-header</title>
5747 <term>Typical use:</term>
5749 <para>Keep your (old and ill) browser from telling web servers your email address</para>
5754 <term>Effect:</term>
5757 Deletes any existing <quote>From:</quote> HTTP header, or replaces it with the
5765 <!-- Boolean, Parameterized, Multi-value -->
5767 <para>Parameterized.</para>
5772 <term>Parameter:</term>
5775 Keyword: <quote>block</quote>, or any user defined value.
5784 The keyword <quote>block</quote> will completely remove the header
5785 (not to be confused with the <literal><link linkend="block">block</link></literal>
5789 Alternately, you can specify any value you prefer to be sent to the web
5790 server. If you do, it is a matter of fairness not to use any address that
5791 is actually used by a real person.
5794 This action is rarely needed, as modern web browsers don't send
5795 <quote>From:</quote> headers anymore.
5801 <term>Example usage:</term>
5804 <screen>+hide-from-header{block}</screen> or
5805 <screen>+hide-from-header{spam-me-senseless@sittingduck.example.com}</screen>
5813 <!-- ~~~~~ New section ~~~~~ -->
5814 <sect3 renderas="sect4" id="hide-referrer">
5815 <title>hide-referrer</title>
5816 <anchor id="hide-referer">
5819 <term>Typical use:</term>
5821 <para>Conceal which link you followed to get to a particular site</para>
5826 <term>Effect:</term>
5829 Deletes the <quote>Referer:</quote> (sic) HTTP header from the client request,
5830 or replaces it with a forged one.
5837 <!-- Boolean, Parameterized, Multi-value -->
5839 <para>Parameterized.</para>
5844 <term>Parameter:</term>
5848 <para><quote>conditional-block</quote> to delete the header completely if the host has changed.</para>
5851 <para><quote>conditional-forge</quote> to forge the header if the host has changed.</para>
5854 <para><quote>block</quote> to delete the header unconditionally.</para>
5857 <para><quote>forge</quote> to pretend to be coming from the homepage of the server we are talking to.</para>
5860 <para>Any other string to set a user defined referrer.</para>
5870 <literal>conditional-block</literal> is the only parameter,
5871 that isn't easily detected in the server's log file. If it blocks the
5872 referrer, the request will look like the visitor used a bookmark or
5873 typed in the address directly.
5876 Leaving the referrer unmodified for requests on the same host
5877 allows the server owner to see the visitor's <quote>click path</quote>,
5878 but in most cases she could also get that information by comparing
5879 other parts of the log file: for example the User-Agent if it isn't
5880 a very common one, or the user's IP address if it doesn't change between
5884 Always blocking the referrer, or using a custom one, can lead to
5885 failures on servers that check the referrer before they answer any
5886 requests, in an attempt to prevent their content from being
5887 embedded or linked to elsewhere.
5890 Both <literal>conditional-block</literal> and <literal>forge</literal>
5891 will work with referrer checks, as long as content and valid referring page
5892 are on the same host. Most of the time that's the case.
5895 <literal>hide-referer</literal> is an alternate spelling of
5896 <literal>hide-referrer</literal> and the two can be can be freely
5897 substituted with each other. (<quote>referrer</quote> is the
5898 correct English spelling, however the HTTP specification has a bug - it
5899 requires it to be spelled as <quote>referer</quote>.)
5905 <term>Example usage:</term>
5908 <screen>+hide-referrer{forge}</screen> or
5909 <screen>+hide-referrer{http://www.yahoo.com/}</screen>
5917 <!-- ~~~~~ New section ~~~~~ -->
5918 <sect3 renderas="sect4" id="hide-user-agent">
5919 <title>hide-user-agent</title>
5923 <term>Typical use:</term>
5925 <para>Try to conceal your type of browser and client operating system</para>
5930 <term>Effect:</term>
5933 Replaces the value of the <quote>User-Agent:</quote> HTTP header
5934 in client requests with the specified value.
5941 <!-- Boolean, Parameterized, Multi-value -->
5943 <para>Parameterized.</para>
5948 <term>Parameter:</term>
5951 Any user-defined string.
5961 This can lead to problems on web sites that depend on looking at this header in
5962 order to customize their content for different browsers (which, by the
5963 way, is <emphasis>NOT</emphasis> the right thing to do: good web sites
5964 work browser-independently).
5968 Using this action in multi-user setups or wherever different types of
5969 browsers will access the same <application>Privoxy</application> is
5970 <emphasis>not recommended</emphasis>. In single-user, single-browser
5971 setups, you might use it to delete your OS version information from
5972 the headers, because it is an invitation to exploit known bugs for your
5973 OS. It is also occasionally useful to forge this in order to access
5974 sites that won't let you in otherwise (though there may be a good
5975 reason in some cases).
5978 More information on known user-agent strings can be found at
5979 <ulink url="http://www.user-agents.org/">http://www.user-agents.org/</ulink>
5981 <ulink url="http://en.wikipedia.org/wiki/User_agent">http://en.wikipedia.org/wiki/User_agent</ulink>.
5987 <term>Example usage:</term>
5990 <screen>+hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}</screen>
5998 <!-- ~~~~~ New section ~~~~~ -->
5999 <sect3 renderas="sect4" id="limit-connect">
6000 <title>limit-connect</title>
6004 <term>Typical use:</term>
6006 <para>Prevent abuse of <application>Privoxy</application> as a TCP proxy relay or disable SSL for untrusted sites</para>
6011 <term>Effect:</term>
6014 Specifies to which ports HTTP CONNECT requests are allowable.
6021 <!-- Boolean, Parameterized, Multi-value -->
6023 <para>Parameterized.</para>
6028 <term>Parameter:</term>
6031 A comma-separated list of ports or port ranges (the latter using dashes, with the minimum
6032 defaulting to 0 and the maximum to 65K).
6041 By default, i.e. if no <literal>limit-connect</literal> action applies,
6042 <application>Privoxy</application> allows HTTP CONNECT requests to all
6043 ports. Use <literal>limit-connect</literal> if fine-grained control
6044 is desired for some or all destinations.
6047 The CONNECT methods exists in HTTP to allow access to secure websites
6048 (<quote>https://</quote> URLs) through proxies. It works very simply:
6049 the proxy connects to the server on the specified port, and then
6050 short-circuits its connections to the client and to the remote server.
6051 This means CONNECT-enabled proxies can be used as TCP relays very easily.
6054 <application>Privoxy</application> relays HTTPS traffic without seeing
6055 the decoded content. Websites can leverage this limitation to circumvent &my-app;'s
6056 filters. By specifying an invalid port range you can disable HTTPS entirely.
6062 <term>Example usages:</term>
6064 <!-- I had trouble getting the spacing to look right in my browser -->
6065 <!-- I probably have the wrong font setup, bollocks. -->
6066 <!-- Apparently the emphasis tag uses a proportional font no matter what -->
6068 <screen>+limit-connect{443} # Port 443 is OK.
6069 +limit-connect{80,443} # Ports 80 and 443 are OK.
6070 +limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
6071 +limit-connect{-} # All ports are OK
6072 +limit-connect{,} # No HTTPS/SSL traffic is allowed</screen>
6080 <!-- ~~~~~ New section ~~~~~ -->
6081 <sect3 renderas="sect4" id="limit-cookie-lifetime">
6082 <title>limit-cookie-lifetime</title>
6086 <term>Typical use:</term>
6088 <para>Limit the lifetime of HTTP cookies to a couple of minutes or hours.</para>
6093 <term>Effect:</term>
6096 Overwrites the expires field in Set-Cookie server headers if it's above the specified limit.
6103 <!-- Boolean, Parameterized, Multi-value -->
6105 <para>Parameterized.</para>
6110 <term>Parameter:</term>
6113 The lifetime limit in minutes, or 0.
6122 This action reduces the lifetime of HTTP cookies coming from the
6123 server to the specified number of minutes, starting from the time
6124 the cookie passes Privoxy.
6127 Cookies with a lifetime below the limit are not modified.
6128 The lifetime of session cookies is set to the specified limit.
6131 The effect of this action depends on the server.
6134 In case of servers which refresh their cookies with each response
6135 (or at least frequently), the lifetime limit set by this action
6137 Thus, a session associated with the cookie continues to work with
6138 this action enabled, as long as a new request is made before the
6139 last limit set is reached.
6142 However, some servers send their cookies once, with a lifetime of several
6143 years (the year 2037 is a popular choice), and do not refresh them
6144 until a certain event in the future, for example the user logging out.
6145 In this case this action may limit the absolute lifetime of the session,
6146 even if requests are made frequently.
6149 If the parameter is <quote>0</quote>, this action behaves like
6150 <literal><link linkend="session-cookies-only">session-cookies-only</link></literal>.
6156 <term>Example usages:</term>
6159 <screen>+limit-cookie-lifetime{60}
6167 <!-- ~~~~~ New section ~~~~~ -->
6168 <sect3 renderas="sect4" id="prevent-compression">
6169 <title>prevent-compression</title>
6173 <term>Typical use:</term>
6176 Ensure that servers send the content uncompressed, so it can be
6177 passed through <literal><link linkend="filter">filter</link></literal>s.
6183 <term>Effect:</term>
6186 Removes the Accept-Encoding header which can be used to ask for compressed transfer.
6193 <!-- Boolean, Parameterized, Multi-value -->
6195 <para>Boolean.</para>
6200 <term>Parameter:</term>
6212 More and more websites send their content compressed by default, which
6213 is generally a good idea and saves bandwidth. But the <literal><link
6214 linkend="filter">filter</link></literal> and
6215 <literal><link linkend="deanimate-gifs">deanimate-gifs</link></literal>
6216 actions need access to the uncompressed data.
6219 When compiled with zlib support (available since &my-app; 3.0.7), content that should be
6220 filtered is decompressed on-the-fly and you don't have to worry about this action.
6221 If you are using an older &my-app; version, or one that hasn't been compiled with zlib
6222 support, this action can be used to convince the server to send the content uncompressed.
6225 Most text-based instances compress very well, the size is seldom decreased by less than 50%,
6226 for markup-heavy instances like news feeds saving more than 90% of the original size isn't
6230 Not using compression will therefore slow down the transfer, and you should only
6231 enable this action if you really need it. As of &my-app; 3.0.7 it's disabled in all
6232 predefined action settings.
6235 Note that some (rare) ill-configured sites don't handle requests for uncompressed
6236 documents correctly. Broken PHP applications tend to send an empty document body,
6237 some IIS versions only send the beginning of the content. If you enable
6238 <literal>prevent-compression</literal> per default, you might want to add
6239 exceptions for those sites. See the example for how to do that.
6245 <term>Example usage (sections):</term>
6249 # Selectively turn off compression, and enable a filter
6251 { +filter{tiny-textforms} +prevent-compression }
6252 # Match only these sites
6257 # Or instead, we could set a universal default:
6259 { +prevent-compression }
6262 # Then maybe make exceptions for broken sites:
6264 { -prevent-compression }
6265 .compusa.com/</screen>
6274 <!-- ~~~~~ New section ~~~~~ -->
6275 <sect3 renderas="sect4" id="overwrite-last-modified">
6276 <title>overwrite-last-modified</title>
6282 <term>Typical use:</term>
6284 <para>Prevent yet another way to track the user's steps between sessions.</para>
6289 <term>Effect:</term>
6292 Deletes the <quote>Last-Modified:</quote> HTTP server header or modifies its value.
6299 <!-- Boolean, Parameterized, Multi-value -->
6301 <para>Parameterized.</para>
6306 <term>Parameter:</term>
6309 One of the keywords: <quote>block</quote>, <quote>reset-to-request-time</quote>
6310 and <quote>randomize</quote>
6319 Removing the <quote>Last-Modified:</quote> header is useful for filter
6320 testing, where you want to force a real reload instead of getting status
6321 code <quote>304</quote>, which would cause the browser to reuse the old
6322 version of the page.
6325 The <quote>randomize</quote> option overwrites the value of the
6326 <quote>Last-Modified:</quote> header with a randomly chosen time
6327 between the original value and the current time. In theory the server
6328 could send each document with a different <quote>Last-Modified:</quote>
6329 header to track visits without using cookies. <quote>Randomize</quote>
6330 makes it impossible and the browser can still revalidate cached documents.
6333 <quote>reset-to-request-time</quote> overwrites the value of the
6334 <quote>Last-Modified:</quote> header with the current time. You could use
6335 this option together with
6336 <literal><link linkend="hide-if-modified-since">hide-if-modified-since</link></literal>
6337 to further customize your random range.
6340 The preferred parameter here is <quote>randomize</quote>. It is safe
6341 to use, as long as the time settings are more or less correct.
6342 If the server sets the <quote>Last-Modified:</quote> header to the time
6343 of the request, the random range becomes zero and the value stays the same.
6344 Therefore you should later randomize it a second time with
6345 <literal><link linkend="hide-if-modified-since">hided-if-modified-since</link></literal>,
6349 It is also recommended to use this action together with
6350 <literal><link linkend="crunch-if-none-match">crunch-if-none-match</link></literal>.
6356 <term>Example usage:</term>
6359 <screen># Let the browser revalidate without being tracked across sessions
6360 { +hide-if-modified-since{-60} \
6361 +overwrite-last-modified{randomize} \
6362 +crunch-if-none-match}
6371 <!-- ~~~~~ New section ~~~~~ -->
6372 <sect3 renderas="sect4" id="redirect">
6373 <title>redirect</title>
6379 <term>Typical use:</term>
6382 Redirect requests to other sites.
6388 <term>Effect:</term>
6391 Convinces the browser that the requested document has been moved
6392 to another location and the browser should get it from there.
6399 <!-- Boolean, Parameterized, Multi-value -->
6401 <para>Parameterized</para>
6406 <term>Parameter:</term>
6409 An absolute URL or a single pcrs command.
6418 Requests to which this action applies are answered with a
6419 HTTP redirect to URLs of your choosing. The new URL is
6420 either provided as parameter, or derived by applying a
6421 single pcrs command to the original URL.
6424 The syntax for pcrs commands is documented in the
6425 <link linkend="filter-file">filter file</link> section.
6428 This action will be ignored if you use it together with
6429 <literal><link linkend="block">block</link></literal>.
6430 It can be combined with
6431 <literal><link linkend="fast-redirects">fast-redirects{check-decoded-url}</link></literal>
6432 to redirect to a decoded version of a rewritten URL.
6435 Use this action carefully, make sure not to create redirection loops
6436 and be aware that using your own redirects might make it
6437 possible to fingerprint your requests.
6440 In case of problems with your redirects, or simply to watch
6441 them working, enable <link linkend="DEBUG">debug 128</link>.
6447 <term>Example usages:</term>
6450 <screen># Replace example.com's style sheet with another one
6451 { +redirect{http://localhost/css-replacements/example.com.css} }
6452 example.com/stylesheet\.css
6454 # Create a short, easy to remember nickname for a favorite site
6455 # (relies on the browser accept and forward invalid URLs to &my-app;)
6456 { +redirect{http://www.privoxy.org/user-manual/actions-file.html} }
6459 # Always use the expanded view for Undeadly.org articles
6460 # (Note the $ at the end of the URL pattern to make sure
6461 # the request for the rewritten URL isn't redirected as well)
6462 {+redirect{s@$@&mode=expanded@}}
6463 undeadly.org/cgi\?action=article&sid=\d*$
6465 # Redirect Google search requests to MSN
6466 {+redirect{s@^http://[^/]*/search\?q=([^&]*).*@http://search.msn.com/results.aspx?q=$1@}}
6469 # Redirect MSN search requests to Yahoo
6470 {+redirect{s@^http://[^/]*/results\.aspx\?q=([^&]*).*@http://search.yahoo.com/search?p=$1@}}
6471 search.msn.com//results\.aspx\?q=
6473 # Redirect remote requests for this manual
6474 # to the local version delivered by Privoxy
6475 {+redirect{s@^http://www@http://config@}}
6476 www.privoxy.org/user-manual/</screen>
6485 <!-- ~~~~~ New section ~~~~~ -->
6486 <sect3 renderas="sect4" id="server-header-filter">
6487 <title>server-header-filter</title>
6491 <term>Typical use:</term>
6494 Rewrite or remove single server headers.
6500 <term>Effect:</term>
6503 All server headers to which this action applies are filtered on-the-fly
6504 through the specified regular expression based substitutions.
6511 <!-- boolean, parameterized, Multi-value -->
6513 <para>Parameterized.</para>
6518 <term>Parameter:</term>
6521 The name of a server-header filter, as defined in one of the
6522 <link linkend="filter-file">filter files</link>.
6531 Server-header filters are applied to each header on its own, not to
6532 all at once. This makes it easier to diagnose problems, but on the downside
6533 you can't write filters that only change header x if header y's value is z.
6534 You can do that by using tags though.
6537 Server-header filters are executed after the other header actions have finished
6538 and use their output as input.
6541 Please refer to the <link linkend="filter-file">filter file chapter</link>
6542 to learn which server-header filters are available by default, and how to
6549 <term>Example usage (section):</term>
6553 {+server-header-filter{html-to-xml}}
6554 example.org/xml-instance-that-is-delivered-as-html
6556 {+server-header-filter{xml-to-html}}
6557 example.org/instance-that-is-delivered-as-xml-but-is-not
6567 <!-- ~~~~~ New section ~~~~~ -->
6568 <sect3 renderas="sect4" id="server-header-tagger">
6569 <title>server-header-tagger</title>
6573 <term>Typical use:</term>
6576 Enable or disable filters based on the Content-Type header.
6582 <term>Effect:</term>
6585 Server headers to which this action applies are filtered on-the-fly through
6586 the specified regular expression based substitutions, the result is used as
6594 <!-- boolean, parameterized, Multi-value -->
6596 <para>Parameterized.</para>
6601 <term>Parameter:</term>
6604 The name of a server-header tagger, as defined in one of the
6605 <link linkend="filter-file">filter files</link>.
6614 Server-header taggers are applied to each header on its own,
6615 and as the header isn't modified, each tagger <quote>sees</quote>
6619 Server-header taggers are executed before all other header actions
6620 that modify server headers. Their tags can be used to control
6621 all of the other server-header actions, the content filters
6622 and the crunch actions (<link linkend="redirect">redirect</link>
6623 and <link linkend="block">block</link>).
6626 Obviously crunching based on tags created by server-header taggers
6627 doesn't prevent the request from showing up in the server's log file.
6634 <term>Example usage (section):</term>
6638 # Tag every request with the content type declared by the server
6639 {+server-header-tagger{content-type}}
6650 <!-- ~~~~~ New section ~~~~~ -->
6651 <sect3 renderas="sect4" id="session-cookies-only">
6652 <title>session-cookies-only</title>
6656 <term>Typical use:</term>
6659 Allow only temporary <quote>session</quote> cookies (for the current
6660 browser session <emphasis>only</emphasis>).
6666 <term>Effect:</term>
6669 Deletes the <quote>expires</quote> field from <quote>Set-Cookie:</quote>
6670 server headers. Most browsers will not store such cookies permanently and
6671 forget them in between sessions.
6678 <!-- Boolean, Parameterized, Multi-value -->
6680 <para>Boolean.</para>
6685 <term>Parameter:</term>
6697 This is less strict than <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal> /
6698 <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal> and allows you to browse
6699 websites that insist or rely on setting cookies, without compromising your privacy too badly.
6702 Most browsers will not permanently store cookies that have been processed by
6703 <literal>session-cookies-only</literal> and will forget about them between sessions.
6704 This makes profiling cookies useless, but won't break sites which require cookies so
6705 that you can log in for transactions. This is generally turned on for all
6706 sites, and is the recommended setting.
6709 It makes <emphasis>no sense at all</emphasis> to use <literal>session-cookies-only</literal>
6710 together with <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal> or
6711 <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal>. If you do, cookies
6712 will be plainly killed.
6715 Note that it is up to the browser how it handles such cookies without an <quote>expires</quote>
6716 field. If you use an exotic browser, you might want to try it out to be sure.
6719 This setting also has no effect on cookies that may have been stored
6720 previously by the browser before starting <application>Privoxy</application>.
6721 These would have to be removed manually.
6724 <application>Privoxy</application> also uses
6725 the <link linkend="filter-content-cookies">content-cookies filter</link>
6726 to block some types of cookies. Content cookies are not effected by
6727 <literal>session-cookies-only</literal>.
6733 <term>Example usage:</term>
6736 <screen>+session-cookies-only</screen>
6744 <!-- ~~~~~ New section ~~~~~ -->
6745 <sect3 renderas="sect4" id="set-image-blocker">
6746 <title>set-image-blocker</title>
6750 <term>Typical use:</term>
6752 <para>Choose the replacement for blocked images</para>
6757 <term>Effect:</term>
6760 This action alone doesn't do anything noticeable. If <emphasis>both</emphasis>
6761 <literal><link linkend="block">block</link></literal> <emphasis>and</emphasis> <literal><link
6762 linkend="handle-as-image">handle-as-image</link></literal> <emphasis>also</emphasis>
6763 apply, i.e. if the request is to be blocked as an image,
6764 <emphasis>then</emphasis> the parameter of this action decides what will be
6765 sent as a replacement.
6772 <!-- Boolean, Parameterized, Multi-value -->
6774 <para>Parameterized.</para>
6779 <term>Parameter:</term>
6784 <quote>pattern</quote> to send a built-in checkerboard pattern image. The image is visually
6785 decent, scales very well, and makes it obvious where banners were busted.
6790 <quote>blank</quote> to send a built-in transparent image. This makes banners disappear
6791 completely, but makes it hard to detect where <application>Privoxy</application> has blocked
6792 images on a given page and complicates troubleshooting if <application>Privoxy</application>
6793 has blocked innocent images, like navigation icons.
6798 <quote><replaceable class="parameter">target-url</replaceable></quote> to
6799 send a redirect to <replaceable class="parameter">target-url</replaceable>. You can redirect
6800 to any image anywhere, even in your local filesystem via <quote>file:///</quote> URL.
6801 (But note that not all browsers support redirecting to a local file system).
6804 A good application of redirects is to use special <application>Privoxy</application>-built-in
6805 URLs, which send the built-in images, as <replaceable class="parameter">target-url</replaceable>.
6806 This has the same visual effect as specifying <quote>blank</quote> or <quote>pattern</quote> in
6807 the first place, but enables your browser to cache the replacement image, instead of requesting
6808 it over and over again.
6819 The URLs for the built-in images are <quote>http://config.privoxy.org/send-banner?type=<replaceable
6820 class="parameter">type</replaceable></quote>, where <replaceable class="parameter">type</replaceable> is
6821 either <quote>blank</quote> or <quote>pattern</quote>.
6824 There is a third (advanced) type, called <quote>auto</quote>. It is <emphasis>NOT</emphasis> to be
6825 used in <literal>set-image-blocker</literal>, but meant for use from <link linkend="filter-file">filters</link>.
6826 Auto will select the type of image that would have applied to the referring page, had it been an image.
6832 <term>Example usage:</term>
6838 <screen>+set-image-blocker{pattern}</screen>
6841 Redirect to the BSD daemon:
6844 <screen>+set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}</screen>
6847 Redirect to the built-in pattern for better caching:
6850 <screen>+set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}</screen>
6858 <!-- ~~~~~ New section ~~~~~ -->
6860 <title>Summary</title>
6862 Note that many of these actions have the potential to cause a page to
6863 misbehave, possibly even not to display at all. There are many ways
6864 a site designer may choose to design his site, and what HTTP header
6865 content, and other criteria, he may depend on. There is no way to have hard
6866 and fast rules for all sites. See the <link
6867 linkend="ACTIONSANAT">Appendix</link> for a brief example on troubleshooting
6873 <!-- ~~~~~ New section ~~~~~ -->
6874 <sect2 id="aliases">
6875 <title>Aliases</title>
6877 Custom <quote>actions</quote>, known to <application>Privoxy</application>
6878 as <quote>aliases</quote>, can be defined by combining other actions.
6879 These can in turn be invoked just like the built-in actions.
6880 Currently, an alias name can contain any character except space, tab,
6882 <quote>{</quote> and <quote>}</quote>, but we <emphasis>strongly
6883 recommend</emphasis> that you only use <quote>a</quote> to <quote>z</quote>,
6884 <quote>0</quote> to <quote>9</quote>, <quote>+</quote>, and <quote>-</quote>.
6885 Alias names are not case sensitive, and are not required to start with a
6886 <quote>+</quote> or <quote>-</quote> sign, since they are merely textually
6890 Aliases can be used throughout the actions file, but they <emphasis>must be
6891 defined in a special section at the top of the file!</emphasis>
6892 And there can only be one such section per actions file. Each actions file may
6893 have its own alias section, and the aliases defined in it are only visible
6897 There are two main reasons to use aliases: One is to save typing for frequently
6898 used combinations of actions, the other one is a gain in flexibility: If you
6899 decide once how you want to handle shops by defining an alias called
6900 <quote>shop</quote>, you can later change your policy on shops in
6901 <emphasis>one</emphasis> place, and your changes will take effect everywhere
6902 in the actions file where the <quote>shop</quote> alias is used. Calling aliases
6903 by their purpose also makes your actions files more readable.
6906 Currently, there is one big drawback to using aliases, though:
6907 <application>Privoxy</application>'s built-in web-based action file
6908 editor honors aliases when reading the actions files, but it expands
6909 them before writing. So the effects of your aliases are of course preserved,
6910 but the aliases themselves are lost when you edit sections that use aliases
6915 Now let's define some aliases...
6920 # Useful custom aliases we can use later.
6922 # Note the (required!) section header line and that this section
6923 # must be at the top of the actions file!
6927 # These aliases just save typing later:
6928 # (Note that some already use other aliases!)
6930 +crunch-all-cookies = +<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> +<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
6931 -crunch-all-cookies = -<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> -<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
6932 +block-as-image = +block{Blocked image.} +handle-as-image
6933 allow-all-cookies = -crunch-all-cookies -<link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> -<link linkend="FILTER-CONTENT-COOKIES">filter{content-cookies}</link>
6935 # These aliases define combinations of actions
6936 # that are useful for certain types of sites:
6938 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>
6940 shop = -crunch-all-cookies -<link linkend="FILTER-ALL-POPUPS">filter{all-popups}</link>
6942 # Short names for other aliases, for really lazy people ;-)
6944 c0 = +crunch-all-cookies
6945 c1 = -crunch-all-cookies</screen>
6949 ...and put them to use. These sections would appear in the lower part of an
6950 actions file and define exceptions to the default actions (as specified further
6951 up for the <quote>/</quote> pattern):
6956 # These sites are either very complex or very keen on
6957 # user data and require minimal interference to work:
6960 .office.microsoft.com
6961 .windowsupdate.microsoft.com
6962 # Gmail is really mail.google.com, not gmail.com
6966 # Allow cookies (for setting and retrieving your customer data)
6970 .worldpay.com # for quietpc.com
6973 # These shops require pop-ups:
6975 {-filter{all-popups} -filter{unsolicited-popups}}
6977 .overclockers.co.uk</screen>
6981 Aliases like <quote>shop</quote> and <quote>fragile</quote> are typically used for
6982 <quote>problem</quote> sites that require more than one action to be disabled
6983 in order to function properly.
6989 <!-- ~~~~~ New section ~~~~~ -->
6990 <sect2 id="act-examples">
6991 <title>Actions Files Tutorial</title>
6993 The above chapters have shown <link linkend="actions-file">which actions files
6994 there are and how they are organized</link>, how actions are <link
6995 linkend="actions">specified</link> and <link linkend="actions-apply">applied
6996 to URLs</link>, how <link linkend="af-patterns">patterns</link> work, and how to
6997 define and use <link linkend="aliases">aliases</link>. Now, let's look at an
6998 example <filename>match-all.action</filename>, <filename>default.action</filename>
6999 and <filename>user.action</filename> file and see how all these pieces come together:
7003 <title>match-all.action</title>
7005 Remember <emphasis>all actions are disabled when matching starts</emphasis>,
7006 so we have to explicitly enable the ones we want.
7010 While the <filename>match-all.action</filename> file only contains a
7011 single section, it is probably the most important one. It has only one
7012 pattern, <quote><literal>/</literal></quote>, but this pattern
7013 <link linkend="af-patterns">matches all URLs</link>. Therefore, the set of
7014 actions used in this <quote>default</quote> section <emphasis>will
7015 be applied to all requests as a start</emphasis>. It can be partly or
7016 wholly overridden by other actions files like <filename>default.action</filename>
7017 and <filename>user.action</filename>, but it will still be largely responsible
7018 for your overall browsing experience.
7022 Again, at the start of matching, all actions are disabled, so there is
7023 no need to disable any actions here. (Remember: a <quote>+</quote>
7024 preceding the action name enables the action, a <quote>-</quote> disables!).
7025 Also note how this long line has been made more readable by splitting it into
7026 multiple lines with line continuation.
7032 +<link linkend="CHANGE-X-FORWARDED-FOR">change-x-forwarded-for{block}</link> \
7033 +<link linkend="HIDE-FROM-HEADER">hide-from-header{block}</link> \
7034 +<link linkend="SET-IMAGE-BLOCKER">set-image-blocker{pattern}</link> \
7041 The default behavior is now set.
7046 <title>default.action</title>
7049 If you aren't a developer, there's no need for you to edit the
7050 <filename>default.action</filename> file. It is maintained by
7051 the &my-app; developers and if you disagree with some of the
7052 sections, you should overrule them in your <filename>user.action</filename>.
7056 Understanding the <filename>default.action</filename> file can
7057 help you with your <filename>user.action</filename>, though.
7061 The first section in this file is a special section for internal use
7062 that prevents older &my-app; versions from reading the file:
7067 ##########################################################################
7068 # Settings -- Don't change! For internal Privoxy use ONLY.
7069 ##########################################################################
7071 for-privoxy-version=3.0.11</screen>
7075 After that comes the (optional) alias section. We'll use the example
7076 section from the above <link linkend="aliases">chapter on aliases</link>,
7077 that also explains why and how aliases are used:
7082 ##########################################################################
7084 ##########################################################################
7087 # These aliases just save typing later:
7088 # (Note that some already use other aliases!)
7090 +crunch-all-cookies = +<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> +<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
7091 -crunch-all-cookies = -<link linkend="CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</link> -<link linkend="CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</link>
7092 +block-as-image = +block{Blocked image.} +handle-as-image
7093 mercy-for-cookies = -crunch-all-cookies -<link linkend="SESSION-COOKIES-ONLY">session-cookies-only</link> -<link linkend="FILTER-CONTENT-COOKIES">filter{content-cookies}</link>
7095 # These aliases define combinations of actions
7096 # that are useful for certain types of sites:
7098 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>
7099 shop = -crunch-all-cookies -<link linkend="FILTER-ALL-POPUPS">filter{all-popups}</link></screen>
7103 The first of our specialized sections is concerned with <quote>fragile</quote>
7104 sites, i.e. sites that require minimum interference, because they are either
7105 very complex or very keen on tracking you (and have mechanisms in place that
7106 make them unusable for people who avoid being tracked). We will simply use
7107 our pre-defined <literal>fragile</literal> alias instead of stating the list
7108 of actions explicitly:
7113 ##########################################################################
7114 # Exceptions for sites that'll break under the default action set:
7115 ##########################################################################
7117 # "Fragile" Use a minimum set of actions for these sites (see alias above):
7120 .office.microsoft.com # surprise, surprise!
7121 .windowsupdate.microsoft.com
7122 mail.google.com</screen>
7126 Shopping sites are not as fragile, but they typically
7127 require cookies to log in, and pop-up windows for shopping
7128 carts or item details. Again, we'll use a pre-defined alias:
7137 .worldpay.com # for quietpc.com
7139 .scan.co.uk</screen>
7143 The <literal><link linkend="FAST-REDIRECTS">fast-redirects</link></literal>
7144 action, which may have been enabled in <filename>match-all.action</filename>,
7145 breaks some sites. So disable it for popular sites where we know it misbehaves:
7150 { -<link linkend="FAST-REDIRECTS">fast-redirects</link> }
7154 .altavista.com/.*(like|url|link):http
7155 .altavista.com/trans.*urltext=http
7156 .nytimes.com</screen>
7160 It is important that <application>Privoxy</application> knows which
7161 URLs belong to images, so that <emphasis>if</emphasis> they are to
7162 be blocked, a substitute image can be sent, rather than an HTML page.
7163 Contacting the remote site to find out is not an option, since it
7164 would destroy the loading time advantage of banner blocking, and it
7165 would feed the advertisers information about you. We can mark any
7166 URL as an image with the <literal><link
7167 linkend="handle-as-image">handle-as-image</link></literal> action,
7168 and marking all URLs that end in a known image file extension is a
7174 ##########################################################################
7176 ##########################################################################
7178 # Define which file types will be treated as images, in case they get
7179 # blocked further down this file:
7181 { +<link linkend="HANDLE-AS-IMAGE">handle-as-image</link> }
7182 /.*\.(gif|jpe?g|png|bmp|ico)$</screen>
7186 And then there are known banner sources. They often use scripts to
7187 generate the banners, so it won't be visible from the URL that the
7188 request is for an image. Hence we block them <emphasis>and</emphasis>
7189 mark them as images in one go, with the help of our
7190 <literal>+block-as-image</literal> alias defined above. (We could of
7191 course just as well use <literal>+<link linkend="block">block</link>
7192 +<link linkend="handle-as-image">handle-as-image</link></literal> here.)
7193 Remember that the type of the replacement image is chosen by the
7194 <literal><link linkend="set-image-blocker">set-image-blocker</link></literal>
7195 action. Since all URLs have matched the default section with its
7196 <literal>+<link linkend="set-image-blocker">set-image-blocker</link>{pattern}</literal>
7197 action before, it still applies and needn't be repeated:
7202 # Known ad generators:
7207 .ad.*.doubleclick.net
7208 .a.yimg.com/(?:(?!/i/).)*$
7209 .a[0-9].yimg.com/(?:(?!/i/).)*$
7215 One of the most important jobs of <application>Privoxy</application>
7216 is to block banners. Many of these can be <quote>blocked</quote>
7217 by the <literal><link linkend="filter">filter</link>{banners-by-size}</literal>
7218 action, which we enabled above, and which deletes the references to banner
7219 images from the pages while they are loaded, so the browser doesn't request
7220 them anymore, and hence they don't need to be blocked here. But this naturally
7221 doesn't catch all banners, and some people choose not to use filters, so we
7222 need a comprehensive list of patterns for banner URLs here, and apply the
7223 <literal><link linkend="block">block</link></literal> action to them.
7226 First comes many generic patterns, which do most of the work, by
7227 matching typical domain and path name components of banners. Then comes
7228 a list of individual patterns for specific sites, which is omitted here
7229 to keep the example short:
7234 ##########################################################################
7235 # Block these fine banners:
7236 ##########################################################################
7237 { <link linkend="BLOCK">+block{Banner ads.}</link> }
7245 /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
7246 /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
7248 # Site-specific patterns (abbreviated):
7250 .hitbox.com</screen>
7254 It's quite remarkable how many advertisers actually call their banner
7255 servers ads.<replaceable>company</replaceable>.com, or call the directory
7256 in which the banners are stored simply <quote>banners</quote>. So the above
7257 generic patterns are surprisingly effective.
7260 But being very generic, they necessarily also catch URLs that we don't want
7261 to block. The pattern <literal>.*ads.</literal> e.g. catches
7262 <quote>nasty-<emphasis>ads</emphasis>.nasty-corp.com</quote> as intended,
7263 but also <quote>downlo<emphasis>ads</emphasis>.sourcefroge.net</quote> or
7264 <quote><emphasis>ads</emphasis>l.some-provider.net.</quote> So here come some
7265 well-known exceptions to the <literal>+<link linkend="BLOCK">block</link></literal>
7269 Note that these are exceptions to exceptions from the default! Consider the URL
7270 <quote>downloads.sourcefroge.net</quote>: Initially, all actions are deactivated,
7271 so it wouldn't get blocked. Then comes the defaults section, which matches the
7272 URL, but just deactivates the <literal><link linkend="BLOCK">block</link></literal>
7273 action once again. Then it matches <literal>.*ads.</literal>, an exception to the
7274 general non-blocking policy, and suddenly
7275 <literal><link linkend="BLOCK">+block</link></literal> applies. And now, it'll match
7276 <literal>.*loads.</literal>, where <literal><link linkend="BLOCK">-block</link></literal>
7277 applies, so (unless it matches <emphasis>again</emphasis> further down) it ends up
7278 with no <literal><link linkend="BLOCK">block</link></literal> action applying.
7283 ##########################################################################
7284 # Save some innocent victims of the above generic block patterns:
7285 ##########################################################################
7289 { -<link linkend="BLOCK">block</link> }
7290 adv[io]*. # (for advogato.org and advice.*)
7291 adsl. # (has nothing to do with ads)
7292 adobe. # (has nothing to do with ads either)
7293 ad[ud]*. # (adult.* and add.*)
7294 .edu # (universities don't host banners (yet!))
7295 .*loads. # (downloads, uploads etc)
7303 www.globalintersec.com/adv # (adv = advanced)
7304 www.ugu.com/sui/ugu/adv</screen>
7308 Filtering source code can have nasty side effects,
7309 so make an exception for our friends at sourceforge.net,
7310 and all paths with <quote>cvs</quote> in them. Note that
7311 <literal>-<link linkend="FILTER">filter</link></literal>
7312 disables <emphasis>all</emphasis> filters in one fell swoop!
7317 # Don't filter code!
7319 { -<link linkend="FILTER">filter</link> }
7324 .sourceforge.net</screen>
7328 The actual <filename>default.action</filename> is of course much more
7329 comprehensive, but we hope this example made clear how it works.
7334 <sect3><title>user.action</title>
7337 So far we are painting with a broad brush by setting general policies,
7338 which would be a reasonable starting point for many people. Now,
7339 you might want to be more specific and have customized rules that
7340 are more suitable to your personal habits and preferences. These would
7341 be for narrowly defined situations like your ISP or your bank, and should
7342 be placed in <filename>user.action</filename>, which is parsed after all other
7343 actions files and hence has the last word, over-riding any previously
7344 defined actions. <filename>user.action</filename> is also a
7345 <emphasis>safe</emphasis> place for your personal settings, since
7346 <filename>default.action</filename> is actively maintained by the
7347 <application>Privoxy</application> developers and you'll probably want
7348 to install updated versions from time to time.
7352 So let's look at a few examples of things that one might typically do in
7353 <filename>user.action</filename>:
7357 <!-- brief sample user.action here -->
7361 # My user.action file. <fred@example.com></screen>
7365 As <link linkend="aliases">aliases</link> are local to the actions
7366 file that they are defined in, you can't use the ones from
7367 <filename>default.action</filename>, unless you repeat them here:
7372 # Aliases are local to the file they are defined in.
7373 # (Re-)define aliases for this file:
7377 # These aliases just save typing later, and the alias names should
7378 # be self explanatory.
7380 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
7381 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
7382 allow-all-cookies = -crunch-all-cookies -session-cookies-only
7383 allow-popups = -filter{all-popups}
7384 +block-as-image = +block{Blocked as image.} +handle-as-image
7385 -block-as-image = -block
7387 # These aliases define combinations of actions that are useful for
7388 # certain types of sites:
7390 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referrer
7391 shop = -crunch-all-cookies allow-popups
7393 # Allow ads for selected useful free sites:
7395 allow-ads = -block -filter{banners-by-size} -filter{banners-by-link}
7397 # Alias for specific file types that are text, but might have conflicting
7398 # MIME types. We want the browser to force these to be text documents.
7399 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>
7404 Say you have accounts on some sites that you visit regularly, and
7405 you don't want to have to log in manually each time. So you'd like
7406 to allow persistent cookies for these sites. The
7407 <literal>allow-all-cookies</literal> alias defined above does exactly
7408 that, i.e. it disables crunching of cookies in any direction, and the
7409 processing of cookies to make them only temporary.
7414 { allow-all-cookies }
7418 .redhat.com</screen>
7422 Your bank is allergic to some filter, but you don't know which, so you disable them all:
7427 { -<link linkend="FILTER">filter</link> }
7428 .your-home-banking-site.com</screen>
7432 Some file types you may not want to filter for various reasons:
7437 # Technical documentation is likely to contain strings that might
7438 # erroneously get altered by the JavaScript-oriented filters:
7443 # And this stupid host sends streaming video with a wrong MIME type,
7444 # so that Privoxy thinks it is getting HTML and starts filtering:
7446 stupid-server.example.com/</screen>
7450 Example of a simple <link linkend="BLOCK">block</link> action. Say you've
7451 seen an ad on your favourite page on example.com that you want to get rid of.
7452 You have right-clicked the image, selected <quote>copy image location</quote>
7453 and pasted the URL below while removing the leading http://, into a
7454 <literal>{ +block{} }</literal> section. Note that <literal>{ +handle-as-image
7455 }</literal> need not be specified, since all URLs ending in
7456 <literal>.gif</literal> will be tagged as images by the general rules as set
7457 in default.action anyway:
7462 { +<link linkend="BLOCK">block</link>{Nasty ads.} }
7463 www.example.com/nasty-ads/sponsor\.gif
7464 another.example.net/more/junk/here/</screen>
7468 The URLs of dynamically generated banners, especially from large banner
7469 farms, often don't use the well-known image file name extensions, which
7470 makes it impossible for <application>Privoxy</application> to guess
7471 the file type just by looking at the URL.
7472 You can use the <literal>+block-as-image</literal> alias defined above for
7474 Note that objects which match this rule but then turn out NOT to be an
7475 image are typically rendered as a <quote>broken image</quote> icon by the
7476 browser. Use cautiously.
7485 ar.atwola.com/</screen>
7489 Now you noticed that the default configuration breaks Forbes Magazine,
7490 but you were too lazy to find out which action is the culprit, and you
7491 were again too lazy to give <link linkend="contact">feedback</link>, so
7492 you just used the <literal>fragile</literal> alias on the site, and
7493 -- <emphasis>whoa!</emphasis> -- it worked. The <literal>fragile</literal>
7494 aliases disables those actions that are most likely to break a site. Also,
7495 good for testing purposes to see if it is <application>Privoxy</application>
7496 that is causing the problem or not. We later find other regular sites
7497 that misbehave, and add those to our personalized list of troublemakers:
7505 .mybank.com</screen>
7509 You like the <quote>fun</quote> text replacements in <filename>default.filter</filename>,
7510 but it is disabled in the distributed actions file.
7511 So you'd like to turn it on in your private,
7512 update-safe config, once and for all:
7517 { +<link linkend="filter-fun">filter{fun}</link> }
7518 / # For ALL sites!</screen>
7522 Note that the above is not really a good idea: There are exceptions
7523 to the filters in <filename>default.action</filename> for things that
7524 really shouldn't be filtered, like code on CVS->Web interfaces. Since
7525 <filename>user.action</filename> has the last word, these exceptions
7526 won't be valid for the <quote>fun</quote> filtering specified here.
7530 You might also worry about how your favourite free websites are
7531 funded, and find that they rely on displaying banner advertisements
7532 to survive. So you might want to specifically allow banners for those
7533 sites that you feel provide value to you:
7545 Note that <literal>allow-ads</literal> has been aliased to
7546 <literal>-<link linkend="block">block</link></literal>,
7547 <literal>-<link linkend="filter-banners-by-size">filter{banners-by-size}</link></literal>, and
7548 <literal>-<link linkend="filter-banners-by-link">filter{banners-by-link}</link></literal> above.
7552 Invoke another alias here to force an over-ride of the MIME type <literal>
7553 application/x-sh</literal> which typically would open a download type
7554 dialog. In my case, I want to look at the shell script, and then I can save
7555 it should I choose to.
7565 <filename>user.action</filename> is generally the best place to define
7566 exceptions and additions to the default policies of
7567 <filename>default.action</filename>. Some actions are safe to have their
7568 default policies set here though. So let's set a default policy to have a
7569 <quote>blank</quote> image as opposed to the checkerboard pattern for
7570 <emphasis>ALL</emphasis> sites. <quote>/</quote> of course matches all URL
7576 { +<link linkend="set-image-blocker">set-image-blocker{blank}</link> }
7577 / # ALL sites</screen>
7583 <!-- ~ End section ~ -->
7587 <!-- ~ End section ~ -->
7589 <!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
7591 <sect1 id="filter-file">
7592 <title>Filter Files</title>
7595 On-the-fly text substitutions need
7596 to be defined in a <quote>filter file</quote>. Once defined, they
7597 can then be invoked as an <quote>action</quote>.
7601 &my-app; supports three different filter actions:
7602 <literal><link linkend="filter">filter</link></literal> to
7603 rewrite the content that is send to the client,
7604 <literal><link linkend="client-header-filter">client-header-filter</link></literal>
7605 to rewrite headers that are send by the client, and
7606 <literal><link linkend="server-header-filter">server-header-filter</link></literal>
7607 to rewrite headers that are send by the server.
7611 &my-app; also supports two tagger actions:
7612 <literal><link linkend="client-header-tagger">client-header-tagger</link></literal>
7614 <literal><link linkend="server-header-tagger">server-header-tagger</link></literal>.
7615 Taggers and filters use the same syntax in the filter files, the difference
7616 is that taggers don't modify the text they are filtering, but use a rewritten
7617 version of the filtered text as tag. The tags can then be used to change the
7618 applying actions through sections with <link linkend="tag-pattern">tag-patterns</link>.
7623 Multiple filter files can be defined through the <literal> <link
7624 linkend="filterfile">filterfile</link></literal> config directive. The filters
7625 as supplied by the developers are located in
7626 <filename>default.filter</filename>. It is recommended that any locally
7627 defined or modified filters go in a separately defined file such as
7628 <filename>user.filter</filename>.
7632 Common tasks for content filters are to eliminate common annoyances in
7633 HTML and JavaScript, such as pop-up windows,
7634 exit consoles, crippled windows without navigation tools, the
7635 infamous <BLINK> tag etc, to suppress images with certain
7636 width and height attributes (standard banner sizes or web-bugs),
7637 or just to have fun.
7641 Enabled content filters are applied to any content whose
7642 <quote>Content Type</quote> header is recognised as a sign
7643 of text-based content, with the exception of <literal>text/plain</literal>.
7644 Use the <link linkend="FORCE-TEXT-MODE">force-text-mode</link> action
7645 to also filter other content.
7649 Substitutions are made at the source level, so if you want to <quote>roll
7650 your own</quote> filters, you should first be familiar with HTML syntax,
7651 and, of course, regular expressions.
7655 Just like the <link linkend="actions-file">actions files</link>, the
7656 filter file is organized in sections, which are called <emphasis>filters</emphasis>
7657 here. Each filter consists of a heading line, that starts with one of the
7658 <emphasis>keywords</emphasis> <literal>FILTER:</literal>,
7659 <literal>CLIENT-HEADER-FILTER:</literal> or <literal>SERVER-HEADER-FILTER:</literal>
7660 followed by the filter's <emphasis>name</emphasis>, and a short (one line)
7661 <emphasis>description</emphasis> of what it does. Below that line
7662 come the <emphasis>jobs</emphasis>, i.e. lines that define the actual
7663 text substitutions. By convention, the name of a filter
7664 should describe what the filter <emphasis>eliminates</emphasis>. The
7665 comment is used in the <ulink url="http://config.privoxy.org/">web-based
7666 user interface</ulink>.
7670 Once a filter called <replaceable>name</replaceable> has been defined
7671 in the filter file, it can be invoked by using an action of the form
7672 +<literal><link linkend="filter">filter</link>{<replaceable>name</replaceable>}</literal>
7673 in any <link linkend="actions-file">actions file</link>.
7677 Filter definitions start with a header line that contains the filter
7678 type, the filter name and the filter description.
7679 A content filter header line for a filter called <quote>foo</quote> could look
7684 <screen>FILTER: foo Replace all "foo" with "bar"</screen>
7688 Below that line, and up to the next header line, come the jobs that
7689 define what text replacements the filter executes. They are specified
7690 in a syntax that imitates <ulink url="http://www.perl.org/">Perl</ulink>'s
7691 <literal>s///</literal> operator. If you are familiar with Perl, you
7692 will find this to be quite intuitive, and may want to look at the
7693 PCRS documentation for the subtle differences to Perl behaviour. Most
7694 notably, the non-standard option letter <literal>U</literal> is supported,
7695 which turns the default to ungreedy matching.
7700 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
7701 Expressions</quote></ulink>, you might want to take a look at
7702 the <link linkend="regex">Appendix on regular expressions</link>, and
7703 see the <ulink url="http://perldoc.perl.org/perlre.html">Perl
7705 <ulink url="http://perldoc.perl.org/perlop.html">the
7706 <literal>s///</literal> operator's syntax</ulink> and <ulink
7707 url="http://perldoc.perl.org/perlre.html">Perl-style regular
7708 expressions</ulink> in general.
7709 The below examples might also help to get you started.
7713 <!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
7715 <sect2><title>Filter File Tutorial</title>
7717 Now, let's complete our <quote>foo</quote> content filter. We have already defined
7718 the heading, but the jobs are still missing. Since all it does is to replace
7719 <quote>foo</quote> with <quote>bar</quote>, there is only one (trivial) job
7724 <screen>s/foo/bar/</screen>
7728 But wait! Didn't the comment say that <emphasis>all</emphasis> occurrences
7729 of <quote>foo</quote> should be replaced? Our current job will only take
7730 care of the first <quote>foo</quote> on each page. For global substitution,
7731 we'll need to add the <literal>g</literal> option:
7735 <screen>s/foo/bar/g</screen>
7739 Our complete filter now looks like this:
7742 <screen>FILTER: foo Replace all "foo" with "bar"
7743 s/foo/bar/g</screen>
7747 Let's look at some real filters for more interesting examples. Here you see
7748 a filter that protects against some common annoyances that arise from JavaScript
7749 abuse. Let's look at its jobs one after the other:
7755 FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse
7757 # Get rid of JavaScript referrer tracking. Test page: http://www.randomoddness.com/untitled.htm
7759 s|(<script.*)document\.referrer(.*</script>)|$1"Not Your Business!"$2|Usg</screen>
7763 Following the header line and a comment, you see the job. Note that it uses
7764 <literal>|</literal> as the delimiter instead of <literal>/</literal>, because
7765 the pattern contains a forward slash, which would otherwise have to be escaped
7766 by a backslash (<literal>\</literal>).
7770 Now, let's examine the pattern: it starts with the text <literal><script.*</literal>
7771 enclosed in parentheses. Since the dot matches any character, and <literal>*</literal>
7772 means: <quote>Match an arbitrary number of the element left of myself</quote>, this
7773 matches <quote><script</quote>, followed by <emphasis>any</emphasis> text, i.e.
7774 it matches the whole page, from the start of the first <script> tag.
7778 That's more than we want, but the pattern continues: <literal>document\.referrer</literal>
7779 matches only the exact string <quote>document.referrer</quote>. The dot needed to
7780 be <emphasis>escaped</emphasis>, i.e. preceded by a backslash, to take away its
7781 special meaning as a joker, and make it just a regular dot. So far, the meaning is:
7782 Match from the start of the first <script> tag in a the page, up to, and including,
7783 the text <quote>document.referrer</quote>, if <emphasis>both</emphasis> are present
7784 in the page (and appear in that order).
7788 But there's still more pattern to go. The next element, again enclosed in parentheses,
7789 is <literal>.*</script></literal>. You already know what <literal>.*</literal>
7790 means, so the whole pattern translates to: Match from the start of the first <script>
7791 tag in a page to the end of the last <script> tag, provided that the text
7792 <quote>document.referrer</quote> appears somewhere in between.
7796 This is still not the whole story, since we have ignored the options and the parentheses:
7797 The portions of the page matched by sub-patterns that are enclosed in parentheses, will be
7798 remembered and be available through the variables <literal>$1, $2, ...</literal> in
7799 the substitute. The <literal>U</literal> option switches to ungreedy matching, which means
7800 that the first <literal>.*</literal> in the pattern will only <quote>eat up</quote> all
7801 text in between <quote><script</quote> and the <emphasis>first</emphasis> occurrence
7802 of <quote>document.referrer</quote>, and that the second <literal>.*</literal> will
7803 only span the text up to the <emphasis>first</emphasis> <quote></script></quote>
7804 tag. Furthermore, the <literal>s</literal> option says that the match may span
7805 multiple lines in the page, and the <literal>g</literal> option again means that the
7806 substitution is global.
7810 So, to summarize, the pattern means: Match all scripts that contain the text
7811 <quote>document.referrer</quote>. Remember the parts of the script from
7812 (and including) the start tag up to (and excluding) the string
7813 <quote>document.referrer</quote> as <literal>$1</literal>, and the part following
7814 that string, up to and including the closing tag, as <literal>$2</literal>.
7818 Now the pattern is deciphered, but wasn't this about substituting things? So
7819 lets look at the substitute: <literal>$1"Not Your Business!"$2</literal> is
7820 easy to read: The text remembered as <literal>$1</literal>, followed by
7821 <literal>"Not Your Business!"</literal> (<emphasis>including</emphasis>
7822 the quotation marks!), followed by the text remembered as <literal>$2</literal>.
7823 This produces an exact copy of the original string, with the middle part
7824 (the <quote>document.referrer</quote>) replaced by <literal>"Not Your
7825 Business!"</literal>.
7829 The whole job now reads: Replace <quote>document.referrer</quote> by
7830 <literal>"Not Your Business!"</literal> wherever it appears inside a
7831 <script> tag. Note that this job won't break JavaScript syntax,
7832 since both the original and the replacement are syntactically valid
7833 string objects. The script just won't have access to the referrer
7834 information anymore.
7838 We'll show you two other jobs from the JavaScript taming department, but
7839 this time only point out the constructs of special interest:
7844 # The status bar is for displaying link targets, not pointless blahblah
7846 s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig</screen>
7850 <literal>\s</literal> stands for whitespace characters (space, tab, newline,
7851 carriage return, form feed), so that <literal>\s*</literal> means: <quote>zero
7852 or more whitespace</quote>. The <literal>?</literal> in <literal>.*?</literal>
7853 makes this matching of arbitrary text ungreedy. (Note that the <literal>U</literal>
7854 option is not set). The <literal>['"]</literal> construct means: <quote>a single
7855 <emphasis>or</emphasis> a double quote</quote>. Finally, <literal>\1</literal> is
7856 a back-reference to the first parenthesis just like <literal>$1</literal> above,
7857 with the difference that in the <emphasis>pattern</emphasis>, a backslash indicates
7858 a back-reference, whereas in the <emphasis>substitute</emphasis>, it's the dollar.
7862 So what does this job do? It replaces assignments of single- or double-quoted
7863 strings to the <quote>window.status</quote> object with a dummy assignment
7864 (using a variable name that is hopefully odd enough not to conflict with
7865 real variables in scripts). Thus, it catches many cases where e.g. pointless
7866 descriptions are displayed in the status bar instead of the link target when
7867 you move your mouse over links.
7872 # Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html
7874 s/(<body [^>]*)onunload(.*>)/$1never$2/iU</screen>
7879 <ulink url="http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-htmlevents">OnUnload
7880 event binding</ulink> in the HTML DOM was a <emphasis>CRIME</emphasis>.
7881 When I close a browser window, I want it to close and die. Basta.
7882 This job replaces the <quote>onunload</quote> attribute in
7883 <quote><body></quote> tags with the dummy word <literal>never</literal>.
7884 Note that the <literal>i</literal> option makes the pattern matching
7885 case-insensitive. Also note that ungreedy matching alone doesn't always guarantee
7886 a minimal match: In the first parenthesis, we had to use <literal>[^>]*</literal>
7887 instead of <literal>.*</literal> to prevent the match from exceeding the
7888 <body> tag if it doesn't contain <quote>OnUnload</quote>, but the page's
7893 The last example is from the fun department:
7898 FILTER: fun Fun text replacements
7900 # Spice the daily news:
7902 s/microsoft(?!\.com)/MicroSuck/ig</screen>
7906 Note the <literal>(?!\.com)</literal> part (a so-called negative lookahead)
7907 in the job's pattern, which means: Don't match, if the string
7908 <quote>.com</quote> appears directly following <quote>microsoft</quote>
7909 in the page. This prevents links to microsoft.com from being trashed, while
7910 still replacing the word everywhere else.
7915 # Buzzword Bingo (example for extended regex syntax)
7917 s* industry[ -]leading \
7919 | customer[ -]focused \
7920 | market[ -]driven \
7921 | award[ -]winning # Comments are OK, too! \
7922 | high[ -]performance \
7923 | solutions[ -]based \
7927 *<font color="red"><b>BINGO!</b></font> \
7932 The <literal>x</literal> option in this job turns on extended syntax, and allows for
7933 e.g. the liberal use of (non-interpreted!) whitespace for nicer formatting.
7941 <!-- ~~~~~~~~ New section Header ~~~~~~~~~ -->
7943 <sect2 id="predefined-filters"><title>The Pre-defined Filters</title>
7947 Note each filter is also listed in the +filter action section above. Please
7948 keep these listings in sync.
7953 The distribution <filename>default.filter</filename> file contains a selection of
7954 pre-defined filters for your convenience:
7959 <term><emphasis>js-annoyances</emphasis></term>
7962 The purpose of this filter is to get rid of particularly annoying JavaScript abuse.
7967 replaces JavaScript references to the browser's referrer information
7968 with the string "Not Your Business!". This compliments the <literal><link
7969 linkend="hide-referrer">hide-referrer</link></literal> action on the content level.
7974 removes the bindings to the DOM's
7975 <ulink url="http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-htmlevents">unload
7976 event</ulink> which we feel has no right to exist and is responsible for most <quote>exit consoles</quote>, i.e.
7977 nasty windows that pop up when you close another one.
7982 removes code that causes new windows to be opened with undesired properties, such as being
7983 full-screen, non-resizeable, without location, status or menu bar etc.
7989 Use with caution. This is an aggressive filter, and can break sites that
7990 rely heavily on JavaScript.
7996 <term><emphasis>js-events</emphasis></term>
7999 This is a very radical measure. It removes virtually all JavaScript event bindings, which
8000 means that scripts can not react to user actions such as mouse movements or clicks, window
8001 resizing etc, anymore. Use with caution!
8004 We <emphasis>strongly discourage</emphasis> using this filter as a default since it breaks
8005 many legitimate scripts. It is meant for use only on extra-nasty sites (should you really
8012 <term><emphasis>html-annoyances</emphasis></term>
8015 This filter will undo many common instances of HTML based abuse.
8018 The <literal>BLINK</literal> and <literal>MARQUEE</literal> tags
8019 are neutralized (yeah baby!), and browser windows will be created as
8020 resizeable (as of course they should be!), and will have location,
8021 scroll and menu bars -- even if specified otherwise.
8027 <term><emphasis>content-cookies</emphasis></term>
8030 Most cookies are set in the HTTP dialog, where they can be intercepted
8032 <literal><link linkend="crunch-incoming-cookies">crunch-incoming-cookies</link></literal>
8033 and <literal><link linkend="crunch-outgoing-cookies">crunch-outgoing-cookies</link></literal>
8034 actions. But web sites increasingly make use of HTML meta tags and JavaScript
8035 to sneak cookies to the browser on the content level.
8038 This filter disables most HTML and JavaScript code that reads or sets
8039 cookies. It cannot detect all clever uses of these types of code, so it
8040 should not be relied on as an absolute fix. Use it wherever you would also
8041 use the cookie crunch actions.
8047 <term><emphasis>refresh-tags</emphasis></term>
8050 Disable any refresh tags if the interval is greater than nine seconds (so
8051 that redirections done via refresh tags are not destroyed). This is useful
8052 for dial-on-demand setups, or for those who find this HTML feature
8059 <term><emphasis>unsolicited-popups</emphasis></term>
8062 This filter attempts to prevent only <quote>unsolicited</quote> pop-up
8063 windows from opening, yet still allow pop-up windows that the user
8064 has explicitly chosen to open. It was added in version 3.0.1,
8065 as an improvement over earlier such filters.
8068 Technical note: The filter works by redefining the window.open JavaScript
8069 function to a dummy function, <literal>PrivoxyWindowOpen()</literal>,
8070 during the loading and rendering phase of each HTML page access, and
8071 restoring the function afterward.
8074 This is recommended only for browsers that cannot perform this function
8075 reliably themselves. And be aware that some sites require such windows
8076 in order to function normally. Use with caution.
8082 <term><emphasis>all-popups</emphasis></term>
8085 Attempt to prevent <emphasis>all</emphasis> pop-up windows from opening.
8086 Note this should be used with even more discretion than the above, since
8087 it is more likely to break some sites that require pop-ups for normal
8088 usage. Use with caution.
8094 <term><emphasis>img-reorder</emphasis></term>
8097 This is a helper filter that has no value if used alone. It makes the
8098 <literal>banners-by-size</literal> and <literal>banners-by-link</literal>
8099 (see below) filters more effective and should be enabled together with them.
8105 <term><emphasis>banners-by-size</emphasis></term>
8108 This filter removes image tags purely based on what size they are. Fortunately
8109 for us, many ads and banner images tend to conform to certain standardized
8110 sizes, which makes this filter quite effective for ad stripping purposes.
8113 Occasionally this filter will cause false positives on images that are not ads,
8114 but just happen to be of one of the standard banner sizes.
8117 Recommended only for those who require extreme ad blocking. The default
8118 block rules should catch 95+% of all ads <emphasis>without</emphasis> this filter enabled.
8124 <term><emphasis>banners-by-link</emphasis></term>
8127 This is an experimental filter that attempts to kill any banners if
8128 their URLs seem to point to known or suspected click trackers. It is currently
8129 not of much value and is not recommended for use by default.
8135 <term><emphasis>webbugs</emphasis></term>
8138 Webbugs are small, invisible images (technically 1X1 GIF images), that
8139 are used to track users across websites, and collect information on them.
8140 As an HTML page is loaded by the browser, an embedded image tag causes the
8141 browser to contact a third-party site, disclosing the tracking information
8142 through the requested URL and/or cookies for that third-party domain, without
8143 the user ever becoming aware of the interaction with the third-party site.
8144 HTML-ized spam also uses a similar technique to verify email addresses.
8147 This filter removes the HTML code that loads such <quote>webbugs</quote>.
8153 <term><emphasis>tiny-textforms</emphasis></term>
8156 A rather special-purpose filter that can be used to enlarge textareas (those
8157 multi-line text boxes in web forms) and turn off hard word wrap in them.
8158 It was written for the sourceforge.net tracker system where such boxes are
8159 a nuisance, but it can be handy on other sites, too.
8162 It is not recommended to use this filter as a default.
8168 <term><emphasis>jumping-windows</emphasis></term>
8171 Many consider windows that move, or resize themselves to be abusive. This filter
8172 neutralizes the related JavaScript code. Note that some sites might not display
8173 or behave as intended when using this filter. Use with caution.
8179 <term><emphasis>frameset-borders</emphasis></term>
8182 Some web designers seem to assume that everyone in the world will view their
8183 web sites using the same browser brand and version, screen resolution etc,
8184 because only that assumption could explain why they'd use static frame sizes,
8185 yet prevent their frames from being resized by the user, should they be too
8186 small to show their whole content.
8189 This filter removes the related HTML code. It should only be applied to sites
8196 <term><emphasis>demoronizer</emphasis></term>
8199 Many Microsoft products that generate HTML use non-standard extensions (read:
8200 violations) of the ISO 8859-1 aka Latin-1 character set. This can cause those
8201 HTML documents to display with errors on standard-compliant platforms.
8204 This filter translates the MS-only characters into Latin-1 equivalents.
8205 It is not necessary when using MS products, and will cause corruption of
8206 all documents that use 8-bit character sets other than Latin-1. It's mostly
8207 worthwhile for Europeans on non-MS platforms, if weird garbage characters
8208 sometimes appear on some pages, or user agents that don't correct for this on
8211 My version of Mozilla (ancient) shows litte square boxes for quote
8212 characters, and apostrophes on moronized pages. So many pages have this, I
8213 can read them fine now. HB 08/27/06
8220 <term><emphasis>shockwave-flash</emphasis></term>
8223 A filter for shockwave haters. As the name suggests, this filter strips code
8224 out of web pages that is used to embed shockwave flash objects.
8232 <term><emphasis>quicktime-kioskmode</emphasis></term>
8235 Change HTML code that embeds Quicktime objects so that kioskmode, which
8236 prevents saving, is disabled.
8242 <term><emphasis>fun</emphasis></term>
8245 Text replacements for subversive browsing fun. Make fun of your favorite
8246 Monopolist or play buzzword bingo.
8252 <term><emphasis>crude-parental</emphasis></term>
8255 A demonstration-only filter that shows how <application>Privoxy</application>
8256 can be used to delete web content on a keyword basis.
8262 <term><emphasis>ie-exploits</emphasis></term>
8265 An experimental collection of text replacements to disable malicious HTML and JavaScript
8266 code that exploits known security holes in Internet Explorer.
8269 Presently, it only protects against Nimda and a cross-site scripting bug, and
8270 would need active maintenance to provide more substantial protection.
8276 <term><emphasis>site-specifics</emphasis></term>
8279 Some web sites have very specific problems, the cure for which doesn't apply
8280 anywhere else, or could even cause damage on other sites.
8283 This is a collection of such site-specific cures which should only be applied
8284 to the sites they were intended for, which is what the supplied
8285 <filename>default.action</filename> file does. Users shouldn't need to change
8286 anything regarding this filter.
8292 <term><emphasis>google</emphasis></term>
8295 A CSS based block for Google text ads. Also removes a width limitation
8296 and the toolbar advertisement.
8302 <term><emphasis>yahoo</emphasis></term>
8305 Another CSS based block, this time for Yahoo text ads. And removes
8306 a width limitation as well.
8312 <term><emphasis>msn</emphasis></term>
8315 Another CSS based block, this time for MSN text ads. And removes
8316 tracking URLs, as well as a width limitation.
8322 <term><emphasis>blogspot</emphasis></term>
8325 Cleans up some Blogspot blogs. Read the fine print before using this one!
8328 This filter also intentionally removes some navigation stuff and sets the
8329 page width to 100%. As a result, some rounded <quote>corners</quote> would
8330 appear to early or not at all and as fixing this would require a browser
8331 that understands background-size (CSS3), they are removed instead.
8337 <term><emphasis>xml-to-html</emphasis></term>
8340 Server-header filter to change the Content-Type from xml to html.
8346 <term><emphasis>html-to-xml</emphasis></term>
8349 Server-header filter to change the Content-Type from html to xml.
8355 <term><emphasis>no-ping</emphasis></term>
8358 Removes the non-standard <literal>ping</literal> attribute from
8359 anchor and area HTML tags.
8365 <term><emphasis>hide-tor-exit-notation</emphasis></term>
8368 Client-header filter to remove the <command>Tor</command> exit node notation
8369 found in Host and Referer headers.
8372 If &my-app; and <command>Tor</command> are chained and &my-app;
8373 is configured to use socks4a, one can use <quote>http://www.example.org.foobar.exit/</quote>
8374 to access the host <quote>www.example.org</quote> through the
8375 <command>Tor</command> exit node <quote>foobar</quote>.
8378 As the HTTP client isn't aware of this notation, it treats the
8379 whole string <quote>www.example.org.foobar.exit</quote> as host and uses it
8380 for the <quote>Host</quote> and <quote>Referer</quote> headers. From the
8381 server's point of view the resulting headers are invalid and can cause problems.
8384 An invalid <quote>Referer</quote> header can trigger <quote>hot-linking</quote>
8385 protections, an invalid <quote>Host</quote> header will make it impossible for
8386 the server to find the right vhost (several domains hosted on the same IP address).
8389 This client-header filter removes the <quote>foo.exit</quote> part in those headers
8390 to prevent the mentioned problems. Note that it only modifies
8391 the HTTP headers, it doesn't make it impossible for the server
8392 to detect your <command>Tor</command> exit node based on the IP address
8393 the request is coming from.
8400 <term><emphasis> </emphasis></term>
8414 <!-- ~ End section ~ -->
8418 <!-- ~~~~~ New section ~~~~~ -->
8420 <sect1 id="templates">
8421 <title>Privoxy's Template Files</title>
8423 All <application>Privoxy</application> built-in pages, i.e. error pages such as the
8424 <ulink url="http://show-the-404-error.page"><quote>404 - No Such Domain</quote>
8425 error page</ulink>, the <ulink
8426 url="http://ads.bannerserver.example.com/nasty-ads/sponsor.html"><quote>BLOCKED</quote>
8428 and all pages of its <ulink url="http://config.privoxy.org/">web-based
8429 user interface</ulink>, are generated from <emphasis>templates</emphasis>.
8430 (<application>Privoxy</application> must be running for the above links to work as
8435 These templates are stored in a subdirectory of the <link linkend="confdir">configuration
8436 directory</link> called <filename>templates</filename>. On Unixish platforms,
8438 <ulink url="file:///etc/privoxy/templates/"><filename>/etc/privoxy/templates/</filename></ulink>.
8442 The templates are basically normal HTML files, but with place-holders (called symbols
8443 or exports), which <application>Privoxy</application> fills at run time. It
8444 is possible to edit the templates with a normal text editor, should you want
8445 to customize them. (<emphasis>Not recommended for the casual
8446 user</emphasis>). Should you create your own custom templates, you should use
8447 the <filename>config</filename> setting <link linkend="templdir">templdir</link>
8448 to specify an alternate location, so your templates do not get overwritten
8452 Note that just like in configuration files, lines starting
8453 with <literal>#</literal> are ignored when the templates are filled in.
8457 The place-holders are of the form <literal>@name@</literal>, and you will
8458 find a list of available symbols, which vary from template to template,
8459 in the comments at the start of each file. Note that these comments are not
8460 always accurate, and that it's probably best to look at the existing HTML
8461 code to find out which symbols are supported and what they are filled in with.
8465 A special application of this substitution mechanism is to make whole
8466 blocks of HTML code disappear when a specific symbol is set. We use this
8467 for many purposes, one of them being to include the beta warning in all
8468 our user interface (CGI) pages when <application>Privoxy</application>
8469 is in an alpha or beta development stage:
8474 <!-- @if-unstable-start -->
8476 ... beta warning HTML code goes here ...
8478 <!-- if-unstable-end@ --></screen>
8482 If the "unstable" symbol is set, everything in between and including
8483 <literal>@if-unstable-start</literal> and <literal>if-unstable-end@</literal>
8484 will disappear, leaving nothing but an empty comment:
8488 <screen><!-- --></screen>
8492 There's also an if-then-else construct and an <literal>#include</literal>
8493 mechanism, but you'll sure find out if you are inclined to edit the
8498 All templates refer to a style located at
8499 <ulink url="http://config.privoxy.org/send-stylesheet"><literal>http://config.privoxy.org/send-stylesheet</literal></ulink>.
8500 This is, of course, locally served by <application>Privoxy</application>
8501 and the source for it can be found and edited in the
8502 <filename>cgi-style.css</filename> template.
8507 <!-- ~ End section ~ -->
8511 <!-- ~~~~~ New section ~~~~~ -->
8513 <sect1 id="contact"><title>Contacting the Developers, Bug Reporting and Feature
8516 <!-- Include contacting.sgml boilerplate: -->
8518 <!-- end boilerplate -->
8522 <!-- ~ End section ~ -->
8525 <!-- ~~~~~ New section ~~~~~ -->
8526 <sect1 id="copyright"><title>Privoxy Copyright, License and History</title>
8528 <!-- Include copyright.sgml: -->
8530 <!-- end copyright -->
8532 <!-- ~~~~~ New section ~~~~~ -->
8533 <sect2><title>License</title>
8534 <!-- Include copyright.sgml: -->
8536 <!-- end copyright -->
8538 <!-- ~ End section ~ -->
8541 <!-- ~~~~~ New section ~~~~~ -->
8543 <sect2 id="history"><title>History</title>
8544 <!-- Include history.sgml: -->
8546 <!-- end history -->
8549 <sect2 id="authors"><title>Authors</title>
8550 <!-- Include p-authors.sgml: -->
8552 <!-- end authors -->
8557 <!-- ~ End section ~ -->
8560 <!-- ~~~~~ New section ~~~~~ -->
8561 <sect1 id="seealso"><title>See Also</title>
8562 <!-- Include seealso.sgml: -->
8564 <!-- end seealso -->
8569 <!-- ~~~~~ New section ~~~~~ -->
8570 <sect1 id="appendix"><title>Appendix</title>
8573 <!-- ~~~~~ New section ~~~~~ -->
8575 <title>Regular Expressions</title>
8577 <application>Privoxy</application> uses Perl-style <quote>regular
8578 expressions</quote> in its <link linkend="actions-file">actions
8579 files</link> and <link linkend="filter-file">filter file</link>,
8580 through the <ulink url="http://www.pcre.org/">PCRE</ulink> and
8583 <ulink url="http://www.oesterhelt.org/pcrs/">PCRS</ulink> libraries.
8585 <application>PCRS</application> libraries.
8589 If you are reading this, you probably don't understand what <quote>regular
8590 expressions</quote> are, or what they can do. So this will be a very brief
8591 introduction only. A full explanation would require a <ulink
8592 url="http://www.oreilly.com/catalog/regex/">book</ulink> ;-)
8596 Regular expressions provide a language to describe patterns that can be
8597 run against strings of characters (letter, numbers, etc), to see if they
8598 match the string or not. The patterns are themselves (sometimes complex)
8599 strings of literal characters, combined with wild-cards, and other special
8600 characters, called meta-characters. The <quote>meta-characters</quote> have
8601 special meanings and are used to build complex patterns to be matched against.
8602 Perl Compatible Regular Expressions are an especially convenient
8603 <quote>dialect</quote> of the regular expression language.
8607 To make a simple analogy, we do something similar when we use wild-card
8608 characters when listing files with the <command>dir</command> command in DOS.
8609 <literal>*.*</literal> matches all filenames. The <quote>special</quote>
8610 character here is the asterisk which matches any and all characters. We can be
8611 more specific and use <literal>?</literal> to match just individual
8612 characters. So <quote>dir file?.text</quote> would match
8613 <quote>file1.txt</quote>, <quote>file2.txt</quote>, etc. We are pattern
8614 matching, using a similar technique to <quote>regular expressions</quote>!
8618 Regular expressions do essentially the same thing, but are much, much more
8619 powerful. There are many more <quote>special characters</quote> and ways of
8620 building complex patterns however. Let's look at a few of the common ones,
8621 and then some examples:
8626 <emphasis>.</emphasis> - Matches any single character, e.g. <quote>a</quote>,
8627 <quote>A</quote>, <quote>4</quote>, <quote>:</quote>, or <quote>@</quote>.
8629 </simplelist></para>
8633 <emphasis>?</emphasis> - The preceding character or expression is matched ZERO or ONE
8636 </simplelist></para>
8640 <emphasis>+</emphasis> - The preceding character or expression is matched ONE or MORE
8643 </simplelist></para>
8647 <emphasis>*</emphasis> - The preceding character or expression is matched ZERO or MORE
8650 </simplelist></para>
8654 <emphasis>\</emphasis> - The <quote>escape</quote> character denotes that
8655 the following character should be taken literally. This is used where one of the
8656 special characters (e.g. <quote>.</quote>) needs to be taken literally and
8657 not as a special meta-character. Example: <quote>example\.com</quote>, makes
8658 sure the period is recognized only as a period (and not expanded to its
8659 meta-character meaning of any single character).
8661 </simplelist></para>
8665 <emphasis>[ ]</emphasis> - Characters enclosed in brackets will be matched if
8666 any of the enclosed characters are encountered. For instance, <quote>[0-9]</quote>
8667 matches any numeric digit (zero through nine). As an example, we can combine
8668 this with <quote>+</quote> to match any digit one of more times: <quote>[0-9]+</quote>.
8670 </simplelist></para>
8674 <emphasis>( )</emphasis> - parentheses are used to group a sub-expression,
8675 or multiple sub-expressions.
8677 </simplelist></para>
8681 <emphasis>|</emphasis> - The <quote>bar</quote> character works like an
8682 <quote>or</quote> conditional statement. A match is successful if the
8683 sub-expression on either side of <quote>|</quote> matches. As an example:
8684 <quote>/(this|that) example/</quote> uses grouping and the bar character
8685 and would match either <quote>this example</quote> or <quote>that
8686 example</quote>, and nothing else.
8688 </simplelist></para>
8691 These are just some of the ones you are likely to use when matching URLs with
8692 <application>Privoxy</application>, and is a long way from a definitive
8693 list. This is enough to get us started with a few simple examples which may
8694 be more illuminating:
8698 <emphasis><literal>/.*/banners/.*</literal></emphasis> - A simple example
8699 that uses the common combination of <quote>.</quote> and <quote>*</quote> to
8700 denote any character, zero or more times. In other words, any string at all.
8701 So we start with a literal forward slash, then our regular expression pattern
8702 (<quote>.*</quote>) another literal forward slash, the string
8703 <quote>banners</quote>, another forward slash, and lastly another
8704 <quote>.*</quote>. We are building
8705 a directory path here. This will match any file with the path that has a
8706 directory named <quote>banners</quote> in it. The <quote>.*</quote> matches
8707 any characters, and this could conceivably be more forward slashes, so it
8708 might expand into a much longer looking path. For example, this could match:
8709 <quote>/eye/hate/spammers/banners/annoy_me_please.gif</quote>, or just
8710 <quote>/banners/annoying.html</quote>, or almost an infinite number of other
8711 possible combinations, just so it has <quote>banners</quote> in the path
8716 And now something a little more complex:
8720 <emphasis><literal>/.*/adv((er)?ts?|ertis(ing|ements?))?/</literal></emphasis> -
8721 We have several literal forward slashes again (<quote>/</quote>), so we are
8722 building another expression that is a file path statement. We have another
8723 <quote>.*</quote>, so we are matching against any conceivable sub-path, just so
8724 it matches our expression. The only true literal that <emphasis>must
8725 match</emphasis> our pattern is <application>adv</application>, together with
8726 the forward slashes. What comes after the <quote>adv</quote> string is the
8731 Remember the <quote>?</quote> means the preceding expression (either a
8732 literal character or anything grouped with <quote>(...)</quote> in this case)
8733 can exist or not, since this means either zero or one match. So
8734 <quote>((er)?ts?|ertis(ing|ements?))</quote> is optional, as are the
8735 individual sub-expressions: <quote>(er)</quote>,
8736 <quote>(ing|ements?)</quote>, and the <quote>s</quote>. The <quote>|</quote>
8737 means <quote>or</quote>. We have two of those. For instance,
8738 <quote>(ing|ements?)</quote>, can expand to match either <quote>ing</quote>
8739 <emphasis>OR</emphasis> <quote>ements?</quote>. What is being done here, is an
8740 attempt at matching as many variations of <quote>advertisement</quote>, and
8741 similar, as possible. So this would expand to match just <quote>adv</quote>,
8742 or <quote>advert</quote>, or <quote>adverts</quote>, or
8743 <quote>advertising</quote>, or <quote>advertisement</quote>, or
8744 <quote>advertisements</quote>. You get the idea. But it would not match
8745 <quote>advertizements</quote> (with a <quote>z</quote>). We could fix that by
8746 changing our regular expression to:
8747 <quote>/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/</quote>, which would then match
8752 <emphasis><literal>/.*/advert[0-9]+\.(gif|jpe?g)</literal></emphasis> - Again
8753 another path statement with forward slashes. Anything in the square brackets
8754 <quote>[ ]</quote> can be matched. This is using <quote>0-9</quote> as a
8755 shorthand expression to mean any digit one through nine. It is the same as
8756 saying <quote>0123456789</quote>. So any digit matches. The <quote>+</quote>
8757 means one or more of the preceding expression must be included. The preceding
8758 expression here is what is in the square brackets -- in this case, any digit
8759 one through nine. Then, at the end, we have a grouping: <quote>(gif|jpe?g)</quote>.
8760 This includes a <quote>|</quote>, so this needs to match the expression on
8761 either side of that bar character also. A simple <quote>gif</quote> on one side, and the other
8762 side will in turn match either <quote>jpeg</quote> or <quote>jpg</quote>,
8763 since the <quote>?</quote> means the letter <quote>e</quote> is optional and
8764 can be matched once or not at all. So we are building an expression here to
8765 match image GIF or JPEG type image file. It must include the literal
8766 string <quote>advert</quote>, then one or more digits, and a <quote>.</quote>
8767 (which is now a literal, and not a special character, since it is escaped
8768 with <quote>\</quote>), and lastly either <quote>gif</quote>, or
8769 <quote>jpeg</quote>, or <quote>jpg</quote>. Some possible matches would
8770 include: <quote>//advert1.jpg</quote>,
8771 <quote>/nasty/ads/advert1234.gif</quote>,
8772 <quote>/banners/from/hell/advert99.jpg</quote>. It would not match
8773 <quote>advert1.gif</quote> (no leading slash), or
8774 <quote>/adverts232.jpg</quote> (the expression does not include an
8775 <quote>s</quote>), or <quote>/advert1.jsp</quote> (<quote>jsp</quote> is not
8776 in the expression anywhere).
8780 We are barely scratching the surface of regular expressions here so that you
8781 can understand the default <application>Privoxy</application>
8782 configuration files, and maybe use this knowledge to customize your own
8783 installation. There is much, much more that can be done with regular
8784 expressions. Now that you know enough to get started, you can learn more on
8789 More reading on Perl Compatible Regular expressions:
8790 <ulink url="http://perldoc.perl.org/perlre.html">http://perldoc.perl.org/perlre.html</ulink>
8794 For information on regular expression based substitutions and their applications
8795 in filters, please see the <link linkend="filter-file">filter file tutorial</link>
8800 <!-- ~ End section ~ -->
8803 <!-- ~~~~~ New section ~~~~~ -->
8805 <title>Privoxy's Internal Pages</title>
8808 Since <application>Privoxy</application> proxies each requested
8809 web page, it is easy for <application>Privoxy</application> to
8810 trap certain special URLs. In this way, we can talk directly to
8811 <application>Privoxy</application>, and see how it is
8812 configured, see how our rules are being applied, change these
8813 rules and other configuration options, and even turn
8814 <application>Privoxy's</application> filtering off, all with
8820 The URLs listed below are the special ones that allow direct access
8821 to <application>Privoxy</application>. Of course,
8822 <application>Privoxy</application> must be running to access these. If
8823 not, you will get a friendly error message. Internet access is not
8836 <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
8840 There is a shortcut: <ulink url="http://p.p/">http://p.p/</ulink> (But it
8841 doesn't provide a fall-back to a real page, in case the request is not
8842 sent through <application>Privoxy</application>)
8848 Show information about the current configuration, including viewing and
8849 editing of actions files:
8853 <ulink url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
8860 Show the source code version numbers:
8864 <ulink url="http://config.privoxy.org/show-version">http://config.privoxy.org/show-version</ulink>
8871 Show the browser's request headers:
8875 <ulink url="http://config.privoxy.org/show-request">http://config.privoxy.org/show-request</ulink>
8882 Show which actions apply to a URL and why:
8886 <ulink url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
8893 Toggle Privoxy on or off. This feature can be turned off/on in the main
8894 <filename>config</filename> file. When toggled <quote>off</quote>, <quote>Privoxy</quote>
8895 continues to run, but only as a pass-through proxy, with no actions taking
8900 <ulink url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>
8904 Short cuts. Turn off, then on:
8908 <ulink url="http://config.privoxy.org/toggle?set=disable">http://config.privoxy.org/toggle?set=disable</ulink>
8913 <ulink url="http://config.privoxy.org/toggle?set=enable">http://config.privoxy.org/toggle?set=enable</ulink>
8922 These may be bookmarked for quick reference. See next.
8926 <sect3 id="bookmarklets">
8927 <title>Bookmarklets</title>
8929 Below are some <quote>bookmarklets</quote> to allow you to easily access a
8930 <quote>mini</quote> version of some of <application>Privoxy's</application>
8931 special pages. They are designed for MS Internet Explorer, but should work
8932 equally well in Netscape, Mozilla, and other browsers which support
8933 JavaScript. They are designed to run directly from your bookmarks - not by
8934 clicking the links below (although that should work for testing).
8937 To save them, right-click the link and choose <quote>Add to Favorites</quote>
8938 (IE) or <quote>Add Bookmark</quote> (Netscape). You will get a warning that
8939 the bookmark <quote>may not be safe</quote> - just click OK. Then you can run the
8940 Bookmarklet directly from your favorites/bookmarks. For even faster access,
8941 you can put them on the <quote>Links</quote> bar (IE) or the <quote>Personal
8942 Toolbar</quote> (Netscape), and run them with a single click.
8951 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>
8958 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>
8965 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)
8972 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>
8978 <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>
8984 <ulink url="javascript:void(window.open('http://config.privoxy.org/show-url-info?url='+escape(location.href),'Why').focus());">Privoxy - Why?</ulink>
8991 Credit: The site which gave us the general idea for these bookmarklets is
8992 <ulink url="http://www.bookmarklets.com/">www.bookmarklets.com</ulink>. They
8993 have more information about bookmarklets.
9002 <!-- ~~~~~ New section ~~~~~ -->
9004 <title>Chain of Events</title>
9006 Let's take a quick look at how some of <application>Privoxy's</application>
9007 core features are triggered, and the ensuing sequence of events when a web
9008 page is requested by your browser:
9015 First, your web browser requests a web page. The browser knows to send
9016 the request to <application>Privoxy</application>, which will in turn,
9017 relay the request to the remote web server after passing the following
9023 <application>Privoxy</application> traps any request for its own internal CGI
9024 pages (e.g <ulink url="http://p.p/">http://p.p/</ulink>) and sends the CGI page back to the browser.
9029 Next, <application>Privoxy</application> checks to see if the URL
9031 linkend="BLOCK"><quote>+block</quote></link> patterns. If
9032 so, the URL is then blocked, and the remote web server will not be contacted.
9033 <link linkend="HANDLE-AS-IMAGE"><quote>+handle-as-image</quote></link>
9035 <link linkend="HANDLE-AS-EMPTY-DOCUMENT"><quote>+handle-as-empty-document</quote></link>
9036 are then checked, and if there is no match, an
9037 HTML <quote>BLOCKED</quote> page is sent back to the browser. Otherwise, if
9038 it does match, an image is returned for the former, and an empty text
9039 document for the latter. The type of image would depend on the setting of
9040 <link linkend="SET-IMAGE-BLOCKER"><quote>+set-image-blocker</quote></link>
9041 (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
9046 Untrusted URLs are blocked. If URLs are being added to the
9047 <filename>trust</filename> file, then that is done.
9052 If the URL pattern matches the <link
9053 linkend="FAST-REDIRECTS"><quote>+fast-redirects</quote></link> action,
9054 it is then processed. Unwanted parts of the requested URL are stripped.
9059 Now the rest of the client browser's request headers are processed. If any
9060 of these match any of the relevant actions (e.g. <link
9061 linkend="HIDE-USER-AGENT"><quote>+hide-user-agent</quote></link>,
9062 etc.), headers are suppressed or forged as determined by these actions and
9068 Now the web server starts sending its response back (i.e. typically a web
9074 First, the server headers are read and processed to determine, among other
9075 things, the MIME type (document type) and encoding. The headers are then
9076 filtered as determined by the
9077 <link linkend="CRUNCH-INCOMING-COOKIES"><quote>+crunch-incoming-cookies</quote></link>,
9078 <link linkend="SESSION-COOKIES-ONLY"><quote>+session-cookies-only</quote></link>,
9079 and <link linkend="DOWNGRADE-HTTP-VERSION"><quote>+downgrade-http-version</quote></link>
9085 If any <link linkend="FILTER"><quote>+filter</quote></link> action
9087 linkend="DEANIMATE-GIFS"><quote>+deanimate-gifs</quote></link>
9088 action applies (and the document type fits the action), the rest of the page is
9089 read into memory (up to a configurable limit). Then the filter rules (from
9090 <filename>default.filter</filename> and any other filter files) are
9091 processed against the buffered content. Filters are applied in the order
9092 they are specified in one of the filter files. Animated GIFs, if present,
9093 are reduced to either the first or last frame, depending on the action
9094 setting.The entire page, which is now filtered, is then sent by
9095 <application>Privoxy</application> back to your browser.
9098 If neither a <link linkend="FILTER"><quote>+filter</quote></link> action
9100 linkend="DEANIMATE-GIFS"><quote>+deanimate-gifs</quote></link>
9101 matches, then <application>Privoxy</application> passes the raw data through
9102 to the client browser as it becomes available.
9107 As the browser receives the now (possibly filtered) page content, it
9108 reads and then requests any URLs that may be embedded within the page
9109 source, e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
9110 frames), sounds, etc. For each of these objects, the browser issues a
9111 separate request (this is easily viewable in <application>Privoxy's</application>
9112 logs). And each such request is in turn processed just as above. Note that a
9113 complex web page will have many, many such embedded URLs. If these
9114 secondary requests are to a different server, then quite possibly a very
9115 differing set of actions is triggered.
9122 NOTE: This is somewhat of a simplistic overview of what happens with each URL
9123 request. For the sake of brevity and simplicity, we have focused on
9124 <application>Privoxy's</application> core features only.
9130 <!-- ~~~~~ New section ~~~~~ -->
9131 <sect2 id="actionsanat">
9132 <title>Troubleshooting: Anatomy of an Action</title>
9135 The way <application>Privoxy</application> applies
9136 <link linkend="ACTIONS">actions</link> and <link linkend="FILTER">filters</link>
9137 to any given URL can be complex, and not always so
9138 easy to understand what is happening. And sometimes we need to be able to
9139 <emphasis>see</emphasis> just what <application>Privoxy</application> is
9140 doing. Especially, if something <application>Privoxy</application> is doing
9141 is causing us a problem inadvertently. It can be a little daunting to look at
9142 the actions and filters files themselves, since they tend to be filled with
9143 <link linkend="regex">regular expressions</link> whose consequences are not
9148 One quick test to see if <application>Privoxy</application> is causing a problem
9149 or not, is to disable it temporarily. This should be the first troubleshooting
9150 step. See <link linkend="bookmarklets">the Bookmarklets</link> section on a quick
9151 and easy way to do this (be sure to flush caches afterward!). Looking at the
9152 logs is a good idea too. (Note that both the toggle feature and logging are
9153 enabled via <filename>config</filename> file settings, and may need to be
9154 turned <quote>on</quote>.)
9157 Another easy troubleshooting step to try is if you have done any
9158 customization of your installation, revert back to the installed
9159 defaults and see if that helps. There are times the developers get complaints
9160 about one thing or another, and the problem is more related to a customized
9161 configuration issue.
9165 <application>Privoxy</application> also provides the
9166 <ulink url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
9167 page that can show us very specifically how <application>actions</application>
9168 are being applied to any given URL. This is a big help for troubleshooting.
9172 First, enter one URL (or partial URL) at the prompt, and then
9173 <application>Privoxy</application> will tell us
9174 how the current configuration will handle it. This will not
9175 help with filtering effects (i.e. the <link
9176 linkend="FILTER"><quote>+filter</quote></link> action) from
9177 one of the filter files since this is handled very
9178 differently and not so easy to trap! It also will not tell you about any other
9179 URLs that may be embedded within the URL you are testing. For instance, images
9180 such as ads are expressed as URLs within the raw page source of HTML pages. So
9181 you will only get info for the actual URL that is pasted into the prompt area
9182 -- not any sub-URLs. If you want to know about embedded URLs like ads, you
9183 will have to dig those out of the HTML source. Use your browser's <quote>View
9184 Page Source</quote> option for this. Or right click on the ad, and grab the
9189 Let's try an example, <ulink url="http://google.com">google.com</ulink>,
9190 and look at it one section at a time in a sample configuration (your real
9191 configuration may vary):
9196 Matches for http://www.google.com:
9198 In file: default.action <guibutton>[ View ]</guibutton> <guibutton>[ Edit ]</guibutton>
9200 {+change-x-forwarded-for{block}
9201 +deanimate-gifs {last}
9202 +fast-redirects {check-decoded-url}
9203 +filter {refresh-tags}
9204 +filter {img-reorder}
9205 +filter {banners-by-size}
9207 +filter {jumping-windows}
9208 +filter {ie-exploits}
9209 +hide-from-header {block}
9210 +hide-referrer {forge}
9211 +session-cookies-only
9212 +set-image-blocker {pattern}
9215 { -session-cookies-only }
9221 In file: user.action <guibutton>[ View ]</guibutton> <guibutton>[ Edit ]</guibutton>
9222 (no matches in this file)
9227 This is telling us how we have defined our
9228 <link linkend="ACTIONS"><quote>actions</quote></link>, and
9229 which ones match for our test case, <quote>google.com</quote>.
9230 Displayed is all the actions that are available to us. Remember,
9231 the <literal>+</literal> sign denotes <quote>on</quote>. <literal>-</literal>
9232 denotes <quote>off</quote>. So some are <quote>on</quote> here, but many
9233 are <quote>off</quote>. Each example we try may provide a slightly different
9234 end result, depending on our configuration directives.
9238 is for our <filename>default.action</filename> file. The large, multi-line
9239 listing, is how the actions are set to match for all URLs, i.e. our default
9240 settings. If you look at your <quote>actions</quote> file, this would be the
9241 section just below the <quote>aliases</quote> section near the top. This
9242 will apply to all URLs as signified by the single forward slash at the end
9243 of the listing -- <quote> / </quote>.
9247 But we have defined additional actions that would be exceptions to these general
9248 rules, and then we list specific URLs (or patterns) that these exceptions
9249 would apply to. Last match wins. Just below this then are two explicit
9250 matches for <quote>.google.com</quote>. The first is negating our previous
9251 cookie setting, which was for <link
9252 linkend="SESSION-COOKIES-ONLY"><quote>+session-cookies-only</quote></link>
9253 (i.e. not persistent). So we will allow persistent cookies for google, at
9254 least that is how it is in this example. The second turns
9255 <emphasis>off</emphasis> any <link
9256 linkend="FAST-REDIRECTS"><quote>+fast-redirects</quote></link>
9257 action, allowing this to take place unmolested. Note that there is a leading
9258 dot here -- <quote>.google.com</quote>. This will match any hosts and
9259 sub-domains, in the google.com domain also, such as
9260 <quote>www.google.com</quote> or <quote>mail.google.com</quote>. But it would not
9261 match <quote>www.google.de</quote>! So, apparently, we have these two actions
9262 defined as exceptions to the general rules at the top somewhere in the lower
9263 part of our <filename>default.action</filename> file, and
9264 <quote>google.com</quote> is referenced somewhere in these latter sections.
9268 Then, for our <filename>user.action</filename> file, we again have no hits.
9269 So there is nothing google-specific that we might have added to our own, local
9270 configuration. If there was, those actions would over-rule any actions from
9271 previously processed files, such as <filename>default.action</filename>.
9272 <filename>user.action</filename> typically has the last word. This is the
9273 best place to put hard and fast exceptions,
9277 And finally we pull it all together in the bottom section and summarize how
9278 <application>Privoxy</application> is applying all its <quote>actions</quote>
9279 to <quote>google.com</quote>:
9290 +change-x-forwarded-for{block}
9291 -client-header-filter{hide-tor-exit-notation}
9292 -content-type-overwrite
9293 -crunch-client-header
9294 -crunch-if-none-match
9295 -crunch-incoming-cookies
9296 -crunch-outgoing-cookies
9297 -crunch-server-header
9298 +deanimate-gifs {last}
9299 -downgrade-http-version
9302 -filter {content-cookies}
9303 -filter {all-popups}
9304 -filter {banners-by-link}
9305 -filter {tiny-textforms}
9306 -filter {frameset-borders}
9307 -filter {demoronizer}
9308 -filter {shockwave-flash}
9309 -filter {quicktime-kioskmode}
9311 -filter {crude-parental}
9312 -filter {site-specifics}
9313 -filter {js-annoyances}
9314 -filter {html-annoyances}
9315 +filter {refresh-tags}
9316 -filter {unsolicited-popups}
9317 +filter {img-reorder}
9318 +filter {banners-by-size}
9320 +filter {jumping-windows}
9321 +filter {ie-exploits}
9328 -handle-as-empty-document
9330 -hide-accept-language
9331 -hide-content-disposition
9332 +hide-from-header {block}
9333 -hide-if-modified-since
9334 +hide-referrer {forge}
9337 -overwrite-last-modified
9338 -prevent-compression
9340 -server-header-filter{xml-to-html}
9341 -server-header-filter{html-to-xml}
9342 -session-cookies-only
9343 +set-image-blocker {pattern} </screen>
9347 Notice the only difference here to the previous listing, is to
9348 <quote>fast-redirects</quote> and <quote>session-cookies-only</quote>,
9349 which are activated specifically for this site in our configuration,
9350 and thus show in the <quote>Final Results</quote>.
9354 Now another example, <quote>ad.doubleclick.net</quote>:
9360 { +block{Domains starts with "ad"} }
9363 { +block{Domain contains "ad"} }
9366 { +block{Doubleclick banner server} +handle-as-image }
9367 .[a-vx-z]*.doubleclick.net
9372 We'll just show the interesting part here - the explicit matches. It is
9373 matched three different times. Two <quote>+block{}</quote> sections,
9374 and a <quote>+block{} +handle-as-image</quote>,
9375 which is the expanded form of one of our aliases that had been defined as:
9376 <quote>+block-as-image</quote>. (<link
9377 linkend="ALIASES"><quote>Aliases</quote></link> are defined in
9378 the first section of the actions file and typically used to combine more
9383 Any one of these would have done the trick and blocked this as an unwanted
9384 image. This is unnecessarily redundant since the last case effectively
9385 would also cover the first. No point in taking chances with these guys
9386 though ;-) Note that if you want an ad or obnoxious
9387 URL to be invisible, it should be defined as <quote>ad.doubleclick.net</quote>
9388 is done here -- as both a <link
9389 linkend="BLOCK"><quote>+block{}</quote></link>
9390 <emphasis>and</emphasis> an
9391 <link linkend="HANDLE-AS-IMAGE"><quote>+handle-as-image</quote></link>.
9392 The custom alias <quote><literal>+block-as-image</literal></quote> just
9393 simplifies the process and make it more readable.
9397 One last example. Let's try <quote>http://www.example.net/adsl/HOWTO/</quote>.
9398 This one is giving us problems. We are getting a blank page. Hmmm ...
9404 Matches for http://www.example.net/adsl/HOWTO/:
9406 In file: default.action <guibutton>[ View ]</guibutton> <guibutton>[ Edit ]</guibutton>
9410 +change-x-forwarded-for{block}
9411 -client-header-filter{hide-tor-exit-notation}
9412 -content-type-overwrite
9413 -crunch-client-header
9414 -crunch-if-none-match
9415 -crunch-incoming-cookies
9416 -crunch-outgoing-cookies
9417 -crunch-server-header
9419 -downgrade-http-version
9420 +fast-redirects {check-decoded-url}
9422 -filter {content-cookies}
9423 -filter {all-popups}
9424 -filter {banners-by-link}
9425 -filter {tiny-textforms}
9426 -filter {frameset-borders}
9427 -filter {demoronizer}
9428 -filter {shockwave-flash}
9429 -filter {quicktime-kioskmode}
9431 -filter {crude-parental}
9432 -filter {site-specifics}
9433 -filter {js-annoyances}
9434 -filter {html-annoyances}
9435 +filter {refresh-tags}
9436 -filter {unsolicited-popups}
9437 +filter {img-reorder}
9438 +filter {banners-by-size}
9440 +filter {jumping-windows}
9441 +filter {ie-exploits}
9448 -handle-as-empty-document
9450 -hide-accept-language
9451 -hide-content-disposition
9452 +hide-from-header{block}
9453 +hide-referer{forge}
9455 -overwrite-last-modified
9456 +prevent-compression
9458 -server-header-filter{xml-to-html}
9459 -server-header-filter{html-to-xml}
9460 +session-cookies-only
9461 +set-image-blocker{blank} }
9464 { +block{Path contains "ads".} +handle-as-image }
9470 Ooops, the <quote>/adsl/</quote> is matching <quote>/ads</quote> in our
9471 configuration! But we did not want this at all! Now we see why we get the
9472 blank page. It is actually triggering two different actions here, and
9473 the effects are aggregated so that the URL is blocked, and &my-app; is told
9474 to treat the block as if it were an image. But this is, of course, all wrong.
9475 We could now add a new action below this (or better in our own
9476 <filename>user.action</filename> file) that explicitly
9477 <emphasis>un</emphasis> blocks (
9478 <link linkend="BLOCK"><quote>{-block}</quote></link>) paths with
9479 <quote>adsl</quote> in them (remember, last match in the configuration
9480 wins). There are various ways to handle such exceptions. Example:
9492 Now the page displays ;-)
9493 Remember to flush your browser's caches when making these kinds of changes to
9494 your configuration to insure that you get a freshly delivered page! Or, try
9495 using <literal>Shift+Reload</literal>.
9499 But now what about a situation where we get no explicit matches like
9506 { +block{Path starts with "ads".} +handle-as-image }
9512 That actually was very helpful and pointed us quickly to where the problem
9513 was. If you don't get this kind of match, then it means one of the default
9514 rules in the first section of <filename>default.action</filename> is causing
9515 the problem. This would require some guesswork, and maybe a little trial and
9516 error to isolate the offending rule. One likely cause would be one of the
9517 <link linkend="FILTER"><quote>+filter</quote></link> actions.
9518 These tend to be harder to troubleshoot.
9519 Try adding the URL for the site to one of aliases that turn off
9520 <link linkend="FILTER"><quote>+filter</quote></link>:
9528 .worldpay.com # for quietpc.com
9536 <quote><literal>{ shop }</literal></quote> is an <quote>alias</quote> that expands to
9537 <quote><literal>{ -filter -session-cookies-only }</literal></quote>.
9538 Or you could do your own exception to negate filtering:
9546 # Disable ALL filter actions for sites in this section
9554 This would turn off all filtering for these sites. This is best
9555 put in <filename>user.action</filename>, for local site
9556 exceptions. Note that when a simple domain pattern is used by itself (without
9557 the subsequent path portion), all sub-pages within that domain are included
9558 automatically in the scope of the action.
9562 Images that are inexplicably being blocked, may well be hitting the
9563 <link linkend="FILTER-BANNERS-BY-SIZE"><quote>+filter{banners-by-size}</quote></link>
9565 that images of certain sizes are ad banners (works well
9566 <emphasis>most of the time</emphasis> since these tend to be standardized).
9570 <quote><literal>{ fragile }</literal></quote> is an alias that disables most
9571 actions that are the most likely to cause trouble. This can be used as a
9572 last resort for problem sites.
9578 # Handle with care: easy to break
9580 mybank.example.com</screen>
9585 <emphasis>Remember to flush caches!</emphasis> Note that the
9586 <literal>mail.google</literal> reference lacks the TLD portion (e.g.
9587 <quote>.com</quote>). This will effectively match any TLD with
9588 <literal>google</literal> in it, such as <literal>mail.google.de.</literal>,
9592 If this still does not work, you will have to go through the remaining
9593 actions one by one to find which one(s) is causing the problem.
9602 This program is free software; you can redistribute it
9603 and/or modify it under the terms of the GNU General
9604 Public License as published by the Free Software
9605 Foundation; either version 2 of the License, or (at
9606 your option) any later version.
9608 This program is distributed in the hope that it will
9609 be useful, but WITHOUT ANY WARRANTY; without even the
9610 implied warranty of MERCHANTABILITY or FITNESS FOR A
9611 PARTICULAR PURPOSE. See the GNU General Public
9612 License for more details.
9614 The GNU General Public License should be included with
9615 this file. If not, you can view it at
9616 http://www.gnu.org/copyleft/gpl.html
9617 or write to the Free Software Foundation, Inc.,
9618 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,