1 <!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook V3.1//EN">
3 File : $Source: /cvsroot/ijbswa/current/doc/source/faq.sgml,v $
7 ijbswa.sourceforge.net:/home/groups/i/ij/ijbswa/htdocs/
9 $Id: faq.sgml,v 1.31 2002/03/26 22:29:55 swa Exp $
11 Written by and Copyright (C) 2001 the SourceForge
12 Privoxy team. http://www.privoxy.org/
14 Based on the Internet Junkbuster originally written
15 by and Copyright (C) 1997 Anonymous Coders and
16 Junkbusters Corporation. http://www.junkbusters.com
21 <title>Privoxy Frequently Asked Questions</title>
23 <pubdate>$Id: faq.sgml,v 1.31 2002/03/26 22:29:55 swa Exp $</pubdate>
28 <orgname>By: Privoxy Developers</orgname>
35 This FAQ gives users and developers alike answers to frequently asked
36 questions about <application>Privoxy</application>.
39 <application>Privoxy</application> is a web proxy with advanced filtering
40 capabilities for protecting privacy, filtering web page content, managing
41 cookies, controlling access, and removing ads, banners, pop-ups and other
42 obnoxious Internet junk. <application>Privoxy</application> has a very
43 flexible configuration and can be customized to suit individual needs and
44 tastes. <application>Privoxy</application> has application for both
45 stand-alone systems and multi-user networks.
48 <application>Privoxy</application> is based on the code of the
49 <application>Internet Junkbuster</application>.
50 <application>Junkbuster</application> was originally written by JunkBusters
51 Corporation, and was released as free open-source software under the GNU GPL.
52 Stefan Waldherr made many improvements, and started the SourceForge project
53 to continue development.
58 You can find the latest version of the document at <ulink url="http://www.privoxy.org/faq/">http://www.privoxy.org/faq/</ulink>.
59 Please see the Contact section in the
60 <ulink url="http://www.privoxy.org/user-manual/contact.html">user-manual</ulink> if you want to contact the developers.
64 <!-- Feel free to send a note to the developers at <email>ijbswa-developers@lists.sourceforge.net</email>. -->
70 <!-- ~~~~~ New section ~~~~~ -->
73 <sect1 id="introduction"><title>Introduction</title>
79 <!-- ~~~~~ New section ~~~~~ -->
81 <sect1 id="questions"><title>Frequently Asked Questions</title>
83 <!-- ~~~~~ New section ~~~~~ -->
85 <sect2 id="general"><title>General Information</title>
87 <sect3 id="newjb"><title>What is this new version of <application>Privoxy</application>?</title>
89 The original <application>Internet Junkbuster</application> (tm) is a
90 copyrighted product of <ulink url="http://www.junkbusters.com">Junkbusters
91 Corporation</ulink>. Development of this effort stopped some time ago as of
92 version 2.0.2. Stefan Waldherr started the ijbswa project on <ulink
93 url="http://ijbswa.sourceforge.net">Sourceforge</ulink> to rekindle
94 development. Other developers subsequently joined with Stefan, and have
95 since added many new features, refinements and enhancements.
98 The new <application>Privoxy</application> started with the same
99 <application>Junkbuster</application> code base, but has changed
100 significantly at this point.
107 <title id="whyprivoxy">Why <quote>Privoxy</quote>? Why a name change at all?</title>
109 <application>Privoxy</application> is for <quote>Privacy Enhancing Proxy</quote>.
110 There are possible legal complications from the continued use of the
111 <application>Junkbuster</application> name, which is a trademark of
112 <ulink url="http://junkbusters.com">Junkbusters Corporation</ulink>.
113 (There are no objections from Junkbusters Corporation to the
114 <application>Privoxy</application> project itself though, and they
115 in fact still share our ideals and goals.)
119 The developers also believed that there so many changes from the original
120 code, that it was time to make a clean break from the past and make
121 a name in their own right, especially now with the pending release of
128 <sect3 id="differs"><title>How does it differ from the old <application>Junkbuster?</application></title>
130 All the old features remain. The new <application>Privoxy</application>
131 still blocks ads and banners, still manages cookies, and still helps protect
132 your privacy. But, these are all enhanced, and many new features have been
133 added, all in the same vein.
136 The configuration has changed significantly as well. This is something that
137 users will notice right off the bat. The <quote>blocklist</quote> file does
138 not exist any more. This is replaced by <quote>actions</quote> files, such
139 as <filename>default.actions</filename>. This is where most of the per site
140 configuration is now.
145 <sect3 id="features"><title>What are some of the new features?</title>
147 This section is in both user-manual and faq. Please keep in sync!!!
154 Integrated browser based configuration and control utility (<ulink
155 url="http://p.p">http://p.p</ulink>). Browser-based tracing of rule
162 Modularized configuration that will allow for system wide settings, and
163 individual user settings. (not implemented yet, probably a 3.1 feature)
169 Blocking of annoying pop-up browser windows.
175 HTTP/1.1 compliant (most, but not all 1.1 features are supported).
181 Support for Perl Compatible Regular Expressions in the configuration files, and
182 generally a more sophisticated and flexible configuration syntax over
195 Web page content filtering (removes banners based on size,
196 invisible <quote>web-bugs</quote>, JavaScript, pop-ups, status bar abuse,
203 Bypass many click-tracking scripts (avoids script redirection).
210 Multi-threaded (POSIX and native threads).
216 Auto-detection and re-reading of config file changes.
222 User-customizable HTML templates (e.g. 404 error page).
228 Improved cookie management features (e.g. session based cookies).
234 Builds from source on most UNIX-like systems. Packages available for: Linux
235 (RedHat, SuSE, or Debian), Windows, Sun Solaris, Mac OSX, OS/2, HP-UX 11 and AmigaOS.
242 In addition, the configuration is much more powerful and versatile over-all.
251 <sect3 id="proxymoron"><title>What is a <quote>proxy</quote>? How does
252 <application>Privoxy</application> work? </title>
254 When you connect to a web site with <application>Privoxy</application>,
255 you are really connecting to your locally running version of
256 <application>Privoxy</application>. <application>Privoxy</application>
257 intercepts your requests for the web page, and relays that to the
258 <quote>real</quote> web site. The web site sends the HTTP data stream
259 back to <application>Privoxy</application>, where
260 <application>Privoxy</application> can work its magic before it
261 relays this data back to your web browser.
265 Since <application>Privoxy</application> sits between you and the
266 WWW, it is in a position to intercept and completely manage all web traffic and
267 HTTP content before it gets to your browser.
268 <application>Privoxy</application> uses various programming methods to do
269 this, all of which is under your control via the various configuration
274 There are many kinds of proxies. <application>Privoxy</application> best
275 fits the <quote>filtering proxy</quote> category.
280 <sect3 id="browsers2"><title>My browser does the same things as
281 <application>Privoxy</application>. Why should I use
282 <application>Privoxy</application> at all?</title>
284 Modern browsers do indeed have <emphasis>some</emphasis> of the same
285 functionality as <application>Privoxy</application>. Maybe this is
286 adequate for you. But <application>Privoxy</application> is much more
287 versatile and powerful, and can do a number of things that browsers just can't.
290 In addition, a proxy is good choice if you use multiple browsers, or
291 have a LAN with multiple computers. This way all the configuration
292 is in one place, and you don't have to maintain a similar configuration
293 for possibly many browsers.
300 <sect3 id="license"><title>Is there is a license or fee? What about a
301 warranty? Registration?</title>
303 <application>Privoxy</application> is licensed under the
304 GNU General Public License (GPL). It is free to use, copy,
305 modify or distribute as you wish under the terms of this license.
307 url="http://www.gnu.org/copyleft/gpl.html">http://www.gnu.org/copyleft/gpl.html</ulink>
311 There is no warranty of any kind, expressed, implied or otherwise. That is
312 something that would cost real money ;-) There is no registration either.
313 <application>Privoxy</application> really is <emphasis>free</emphasis>
319 <sect3 id="jointeam"><title>I would like to help you, what do I do?</title>
321 <sect4 id="jointeam-money"><title>Money Money Money</title>
323 We, of course, welcome donations and use the money for domain registering,
324 regular world-wide get-togethers (hahaha). Anyway, we'll soon describe the
325 process how to donate money to the team.
329 <sect4 id="jointeam-work"><title>You want to work with us?</title>
331 Well, helping the team is always a good idea. We welcome new developers,
332 RPM gurus or documentation makers. Simply get an account on sourceforge.net
333 and mail your id to the developer mailing list. Then read the
334 section Quickstart in the developers manual.
337 Once we have added you to the team, you'll have write access to the CVS
338 repository, and together we'll find a suitable task for you.
347 <!-- ~~~~~ New section ~~~~~ -->
349 <sect2 id="installation"><title>Installation</title>
351 <sect3 id="whichbrowsers">
352 <title>Which browsers are supported by <application>Privoxy</application>?</title>
354 Any browser that can be configured to use a <quote>proxy</quote>, which
355 is probably almost all browsers. Direct browser support is not necessary
356 since <application>Privoxy</application> runs as a separate application and
357 just exchanges standard HTML data with your browser.
362 <title>Which operating systems are supported?</title>
364 Right now Win32, Mac OSX, OS/2, AmigaOS, Linux, and many
369 Source code is available, so porting to other operating systems,
370 is always a possibility.
375 <sect3 id="newinstall"><title>Can I install
376 <application>Privoxy</application> over <application>Junkbuster</application>?</title>
378 We recommend you uninstall <application>Junkbuster</application>
379 first to minimize conflicts and confusion. You may want to
380 save your old configuration files for future reference. The configuration
381 is substantially changed.
385 url="http://www.privoxy.org/user-manual/">user-manual</ulink> for
386 platform specific installation instructions. [FIXME: This is meant for after
387 the name change for 3.0!]
393 <title id="firststep">I just installed <application>Privoxy</application>. Is there anything
394 special I have to do now?</title>
397 All browsers must be told to use <application>Privoxy</application>
398 as a proxy by specifying the correct proxy address and port number
399 in the appropriate configuration area for the browser. See below.
406 <sect3 id="localhost"><title>What is the proxy address of <application>Privoxy</application>?</title>
408 If you set up the <application>Privoxy</application> to run on
409 the computer you browse from (rather than your ISP's server or some
410 networked computer on a LAN), the proxy will be on <quote>localhost</quote>
411 (which is the special name used by every computer on the Internet to refer
412 to itself) and the port will be 8118 (unless you have <application>Privoxy</application> to run on a different port with the
413 <emphasis>listen-address</emphasis> config option).
416 When configuring your browser's proxy settings you typically enter
417 the word <quote>localhost</quote> in the boxes next to <quote>HTTP</quote>
418 and <quote>Secure</quote> (HTTPS) and then the number <quote>8118</quote>
419 for <quote>port</quote>. This tells your browser to send all web
420 requests to <application>Privoxy</application> instead of directly to the
424 <application>Privoxy</application> can also be used to proxy for
425 a Local Area Network. In this case, your would enter either the IP
426 address of the LAN host where <application>Privoxy</application>
427 is running, or the equivalent hostname. Port assignment would be
431 <application>Privoxy</application> does not currently handle
432 protocols such as FTP, SMTP, IM, IRC, ICQ, or other Internet
438 <title id="nothing">I just installed <application>Privoxy</application>, and nothing is happening.
439 All the ads are there. What's wrong?</title>
442 Did you configure your browser to use <application>Privoxy</application>
443 as a proxy? It does not sound like it. See above. You might also try flushing
444 the browser's caches to force a full re-reading of pages. You can verify
445 that <application>Privoxy</application> is running, and your browser
446 is correctly configured by entering the special URL:
447 <ulink url="http://p.p/">http://p.p/</ulink>. This should give you
448 a banner that says <quote>This is Privoxy</quote> and
449 access to <application>Privoxy's</application> internal configuration.
450 If you see this, then you are good to go. If not, the browser or
451 <application>Privoxy</application> are not set up correctly.
460 <!-- ~~~~~ New section ~~~~~ -->
462 <sect2 id="configuration"><title>Configuration</title>
464 <sect3 id="newconfig"><title>Can I use my old config files?</title>
466 There are major changes to <application>Junkbuster</application>
467 configuration from version 2.0.x to 2.9.x and later. The older files will
468 not work at all. If this is the case, you will need to re-enter your old
469 data into the new configuration structure. This is probably also a good
470 recommendation even if upgrading from 2.9.x to 3.x since there were
471 many minor changes along the way.
476 <title id="actionsfile">What is an <quote>actions</quote> file?</title>
479 <quote>actions</quote> files are where various actions that
480 <application>Privoxy</application> might take, are configured.
481 Typically, you would define a set of default actions that apply
482 to all URLs, then add exceptions to these defaults.
486 Actions can be defined on a per site basis, or for groups of sites. Actions
487 can also be grouped together and then applied to one or more sites. There
488 are many possible actions that might apply to any given site. As an example,
489 if we are blocking cookies as one of our default
490 <application>actions</application>, but need to accept cookies from a given
491 site, we would define this in our <quote>actions</quote> file.
496 <application>Privoxy</application> comes with several default
497 <application>actions</application> files, with varying degrees
498 of filtering and blocking, as starting points for your own
499 configuration (see below).
504 <sect3 id="actionss">
505 <title>The <quote>actions</quote>concept confuses me. Please list
506 some of these <quote>actions</quote>.</title>
508 These are all explained in the
509 <ulink url="../user-manual/configuration.html#ACTIONSFILE">user-manual</ulink>.
510 Please refer to that.
516 <title id="actconfig">How are actions files configured? What is the easiest
517 way to do this?</title>
520 The easiest way to do this, is to access <application>Privoxy</application>
521 with your web browser at <ulink url="http://p.p/">http://p.p/</ulink>,
523 "<ulink url="http://www.privoxy.org/config/edit-actions">Edit the actions list</ulink>"
524 from the selection list. You can also do this by editing the appropriate
525 file with a text editor.
531 url="../user-manual/configuration.html#ACTIONSFILE">user-manual</ulink> for a
532 detailed explanation of these and other configuration files, and their
533 various options and syntax.
539 FIXME: Commenting these out until we have some data there. HB 03/17/02.
541 <sect3 id="yahoo"><title>How can I make my Yahoo account work?</title>
547 <sect3 id="hotmail"> <title>How can I make my Hotmail account work?</title>
553 <sect3 id="gmx"> <title>How can I make my GMX account work?</title>
560 <sect3 id="configfiles"> <title>What are the differences between
561 intermediate.action, basic.action, etc.?</title>
563 Configuring <application>Privoxy</application> is not easy. To help you get
564 started, we provide you with three different default configurations. The
565 following table shows you, which features are enabled in each configuration.
568 <table frame=all><title>Default Configurations</title>
569 <tgroup cols=5 align=left colsep=1 rowsep=1>
577 <entry>Feature</entry>
578 <entry>default.action</entry>
579 <entry>basic.action</entry>
580 <entry>intermediate.action</entry>
581 <entry>advanced.action</entry>
587 <!-- <entry>f1</entry> -->
588 <!-- <entry>f2</entry> -->
589 <!-- <entry>f3</entry> -->
590 <!-- <entry>f4</entry> -->
591 <!-- <entry>f5</entry> -->
598 <entry>ad-filtering</entry>
606 <entry>blank image</entry>
614 <entry>de-animate GIFs</entry>
622 <entry>referer forging</entry>
630 <entry>jon's +no-cookies-keep (i.e. session cookies only)</entry>
638 <entry>no-popup windows</entry>
646 <entry>fast redirects</entry>
654 <entry>hide-referrer</entry>
662 <entry>hide-useragent</entry>
670 <entry>content-modification</entry>
678 <entry>feature-x</entry>
686 <entry>feature-y</entry>
694 <entry>feature-z</entry>
707 <sect3 id="browseconfig"> <title>Why can I change the configuration with a
708 browser? Does that not raise security issues?</title>
710 What I don't understand, is how I can browser edit the config file as a
711 regular user, while the whole /etc/privoxy hierarchy belongs to the user
712 "privoxy", with only 644 perms.
715 When you use the browser-based editor, <application>Privoxy</application>
716 itself is writing to the config files. Because
717 <application>Privoxy</application> is running as the user "privoxy", it can
718 update the config files.
721 If you don't like this, setting "enable-edit-actions 0" in the config file
722 will disable the browser-based editor. If you're that paranoid, you should
723 also consider setting "enable-remote-toggle 0" to prevent browser-based
724 enabling/disabling of <application>Privoxy</application>.
727 Note that normally only local users can connect to <application>Privoxy</application>, so this is not
728 (normally) a security problem.
734 <title id="filterfile">What is a <quote>default.filter</quote>?</title>
736 The <quote>default.filter</quote> file is used to <quote>filter</quote> any
737 web page content. By <quote>filtering</quote> we mean it can modify, remove,
738 or change <emphasis>anything</emphasis> on the page, including HTML tags, and
739 JavaScript. Regular expressions are used to accomplish this, and operate
740 on a line by line basis. This is potentially a very powerful feature, but
741 requires some expertise.
745 If you are familiar with regular expressions, and HTML, you can look at
746 the provided <filename>default.filter</filename> with a text editor and see
747 some of things it can be used for.
751 Presently, there is no GUI editor option for this part of the configuration,
752 but you can disable/enable various sections of the included default
753 file with the <quote>Actions List Editor</quote> from your browser.
759 <title id="lanconfig">How can I set up <application>Privoxy</application> to act as a proxy for my
762 By default, <application>Privoxy</application> only responds to requests
763 from localhost. To have it act as a server for a network, this needs to be
764 changed in the main config file where the <application>Privoxy</application>
765 configuration is located. In that file is a <quote>listen-address</quote>
766 option. It may be commented out with a <quote>#</quote> symbol. Make sure
767 it is uncommented, and assign it the address of the LAN gateway interface,
768 and port number to use:
773 listen-address 192.168.1.1:8118
778 Save the file, and restart <application>Privoxy</application>. Configure
779 all browsers on the network then to use this address and port number.
786 <title id="noseeum">Instead of ads, now I get a checkerboard pattern. I don't want to see anything.</title>
788 This is a configuration option for images that
789 <application>Privoxy</application> is stopping. You have the choice <!-- of
790 the --> <!-- <application>Privoxy</application> logo, --> a checkerboard
791 pattern, a transparent 1x1 GIF image (aka <quote>blank</quote>), or a custom
796 If you want to see nothing, then change the <quote>+image-blocker</quote>
797 action to <quote>+image-blocker{blank}</quote>. This can be done from the
798 <quote>Edit Actions List</quote> selection at <ulink
799 url="http://p.p/">http://p.p/</ulink>. Or by hand editing the appropriate
800 actions file. This will only effect what is defined as <quote>images</quote>
809 <title id="whyseeum">Why would anybody want to see a checkerboard pattern?</title>
811 This can be helpful for troubleshooting problems. It might also be good
812 for anyone new to <application>Privoxy</application> so that they can
813 see if their favorite pages are displaying correctly, and
814 <application>Privoxy</application> is not inadvertently removing something
821 <title id="blockedisugly">I see large red banners on some pages that say
822 <quote>Blocked</quote>. How do I get rid of this?</title>
824 These are URLs that match something in one of
825 <application>Privoxy's</application> block actions (+block). It is meant
826 to be a warning so that you know something has been blocked and an easy way
827 for you to see why. These are handled differently than what has been defined
828 as <quote>images</quote> (e.g. ad banners). If you want them to be treated
829 as if they were images, so that they can be made invisible, then move the
830 offending URL from the <quote>+block</quote> section to the
831 <quote>+imageblock</quote> section of your actions file. Alternately, you
832 could modify the <quote><filename>block</filename></quote> HTML template that
833 is used by <application>Privoxy</application> to display this, and make it
834 something more to your liking.
839 <sect3 id="otherproxy">
840 <title>How can I make <application>Privoxy</application> work with other
841 proxies like <application>Squid</application>?</title>
843 This can be done. See the <ulink
844 url="../user-manual/configuration.html#FORWARDING">user manual</ulink>,
845 which describes how to do this.
853 <!-- ~~~~~ New section ~~~~~ -->
855 <sect2 id="misc"><title>Miscellaneous</title>
858 <title id="slowsme">How much does <application>Privoxy</application> slow my browsing down? This
859 has to add extra time to browsing.</title>
861 It should not slow you down any in real terms, and may actually help
862 speed things up since ads, banners and other junk are not being displayed.
863 The actual processing time required by <application>Privoxy</application>
864 itself for each page, is relatively small in the overall scheme of things,
865 and happens very quickly. This is typically more than offset by time saved
866 not downloading and rendering ad images.
870 <quote>Filtering</quote> via the <filename>filterfile</filename>
871 mechanism may cause a perceived slowdown, since the entire page is buffered
872 before displaying. See below.
879 <sect3 id="loadingtimes"><title>I noticed considerable
880 delays in page requests compared to the old Junkbuster. What's wrong?</title>
882 Using the default filtering configuration, I noticed considerable delays in
883 page requests compared to the old Junkbuster. Loading pages with large contents
884 seemed to take forever, then suddenly delivering all the content at once.
887 The whole content must be loaded in order to filter, and nothing is is
888 sent to the browser during this time. The loading time does not really
889 change in real numbers, but the feeling is different, because most
890 browsers are able to start rendering incomplete content, giving the
891 user a feeling of "it works".
894 To modify the content of a page (i.e. make frames resizeable again, etc.) and
895 not just replace ads, <application>Privoxy</application> needs to download the
896 entire page first, do its content magic and then send the page to the browser.
901 <sect3 id="configurl"><title>What is the "http://p.p/"?</title>
903 Since <application>Privoxy</application> sits between your web browser and the Internet, it can be
904 programmed to handle certain pages specially.
908 With recent versions of <application>Privoxy</application> (version 2.9.x), you can get some
909 information about <application>Privoxy</application> and change some settings by going to
910 http://p.p/ or, equivalently, http://www.privoxy.org/config/
911 (Note that p.p is far easier to type but may not work in some
916 These pages are *not* forwarded to a server on the Internet - instead they are
917 handled by a special web server which is built in to <application>Privoxy</application>.
921 If you are not running <application>Privoxy</application>, then http://p.p/ will fail, and
922 http://www.privoxy.org/config/ will return a web page telling you
923 you're not running <application>Privoxy</application>.
927 If you have version 2.0.2, then the equivalent is
928 http://example.com/show-proxy-args (but you get far less information, and you
929 should really consider upgrading to 2.9.x).
934 FIXME: commented out until we have data. HB 03/18/02.
936 <sect3 id="badfiledesc"><title>I get the message 'Bad File Descriptor', why?</title>
942 <sect3 id="proxy-chaining"><title>How do I chain <application>Privoxy</application> with other proxies
943 (e.g. squid)?</title>
950 <sect3 id="blocklist"><title>Do you still maintain the blocklists?</title>
952 No. The format of the blocklists has changed significantly in the versions
953 2.9.x. Once we have released the new version, there will again be
954 blocklists that you can update automatically.
958 <sect3 id="newads"><title>How can I submit new ads?</title>
960 As of now, please discontinue to submit new ad blocking infos. Once we
961 have released the new version, there will again be a form on the website,
962 which you can use to contribute new ads.
966 <sect3 id="ip"><title>How can I hide my IP address?</title>
968 You cannot hide your IP address with <application>Privoxy</application> or any other software, since
969 the server needs to know your IP address to send the answer to you.
972 Fortunately there are many publicly usable anonymous proxies out there, which
973 solve the problem by providing a further level of indirection between you and
974 the web server, shared by many people and thus letting your requests "drown"
975 in white noise of unrelated requests as far as user tracking is concerned.
978 Most of them will, however, log your IP address and make it available to the
979 authorities in case you abuse that anonymity for criminal purposes. In fact
980 you can't even rule out that some of them only exist to *collect* information
981 on (those suspicious) people with a more than average preference for privacy.
984 You can find a list of anonymous public proxies at <ulink
985 url="http://www.multiproxy.org/anon_list.htm">multiproxy.org</ulink> and many
990 <!-- <sect3 id="image"><title>What is the imagefile (simage.ini, etc.) for?</title> -->
992 <!-- Anytime <application>Privoxy</application> determines (with the help of the blocklist) that a URL -->
993 <!-- contains an advertisement, it has to decide whether this advertisement is an -->
994 <!-- image or not. <application>Privoxy</application> uses the imagefile for that purpose. -->
999 <title id="anonforsure">Can <application>Privoxy</application> guarantee I am anonymous?</title>
1001 No. Your chances of remaining anonymous are greatly improved, but unless you
1002 are an expert on Internet security it would be safest to assume that
1003 everything you do on the Web can be traced back to you.
1006 <application>Privoxy</application> can remove various information about you,
1007 and allows <emphasis>you</emphasis> more freedom to decide which sites
1008 you can trust. But it's still possible that web sites can find out who you
1009 are. Here's one way this can happen.
1012 A few browsers disclose the user's email address in certain situations, such
1013 as when transferring a file by FTP. <application>Privoxy</application>
1014 does not filter FTP. If you need this feature, or are concerned about the
1015 mail handler of your browser disclosing your email address, you might
1016 consider products such as <application>NSClean</application>.
1019 Browsers available only as binaries could use non-standard headers to give
1020 out any information they can have access to: see the manufacturer's license
1021 agreement. It's impossible to anticipate and prevent every breach of privacy
1022 that might occur. The professionally paranoid prefer browsers available as
1023 source code, because anticipating their behavior is easier. Trust the source,
1030 <title id="sitebreak">Might some things break because header information is
1031 being altered?</title>
1034 Definitely. More and more sites use HTTP header content to decide what to
1035 display and how to display it. There is many ways that this can be handled,
1036 so having hard and fast rules, is tricky.
1040 <quote>USER AGENT</quote> in particular is often used in this way to identify
1041 the browser, and adjust content accordingly. Changing this now is not
1042 recommended, since so many sites do look for this. You may get undesirable
1043 results by changing this.
1047 For instance, different browsers use different encodings of Russian and Czech
1048 characters, certain web servers convert pages on-the-fly according to the
1049 User Agent header. Giving a <quote>User Agent</quote> with the wrong
1050 operating system or browser manufacturer causes some sites in these languages
1051 to be garbled; Surfers to Eastern European sites should change it to
1052 something closer. And then some page access counters work by looking at the
1053 <quote>REFERER</quote> header; they may fail or break if unavailable. The
1054 weather maps of Intellicast have been blocked by their server when no
1055 <quote>REFERER</quote> or cookie is provided, is another example. There are
1056 many, many other ways things can go wrong when trying to fool a web server.
1060 If you have problems with a site, you will have to adjust your configuration
1061 accordingly. Cookies are probably the most likely adjustment that may
1062 be required, but by no means the only one.
1070 <title id="caching">Can <application>Privoxy</application> act as a <quote>caching</quote> proxy to
1071 speed up web browsing?</title>
1073 No, it does not have this ability at all. You want something like
1074 <ulink url="http://www.squid-cache.org/">Squid</ulink> for this. And, yes,
1075 before you ask, <application>Privoxy</application> can co-exist
1076 with other kinds of proxies like <quote>Squid</quote>.
1081 <title id="firewall">What about as a firewall? Can <application>Privoxy</application> protect me?</title>
1083 Not in the way you mean, or in the way a true firewall can, or a proxy that
1084 has this specific capability. <application>Privoxy</application> can help
1085 protect your privacy, but not really protect you from intrusion attempts.
1091 <title id="logo">The <application>Privoxy</application> logo that replaces ads is very blocky
1092 and ugly looking. Can't a better font be used?</title>
1095 This is not a font problem. The logo is an image that is created by
1096 <application>Privoxy</application> on the fly. So as to not waste
1097 memory, the image is rather small. The blockiness comes when the
1098 image is scaled to fill a largish area. There is not much to be done
1099 about this, other than to use one of the other
1100 <quote>imageblock</quote> directives: <emphasis>pattern</emphasis>,
1101 <emphasis>blank</emphasis>, or a URL of your choosing.
1104 Given the above problem, we have decided to remove the logo option entirely
1111 <title id="wasted">I have large empty spaces now where ads used to be.
1112 Why does <application>Privoxy</application> leave these large gaps?</title>
1114 It would be easy enough to just eliminate this space altogether, rather than
1115 fill it with blank space. But, this would create problems with many pages
1116 that use the overall size of the ad to help organize the page layout and
1117 position the various components of the page where they were intended to be.
1118 It is best left this way.
1124 <title id="ssl">How can <application>Privoxy</application> filter Secure (HTTPS) URLs?</title>
1126 This is a limitation since HTTPS transactions are encrypted SSL sessions
1127 between your browser and the secure site, and are meant to be reliably
1128 <emphasis>secure</emphasis> and private. This means that all cookies and HTTP
1129 header information are also encrypted from the time they leave your browser,
1130 to the site, and vice versa. <application>Privoxy</application> does not
1131 try to unencrypt this information, so it just passes through as is.
1132 <application>Privoxy</application> can still catch images and ads that
1133 are embedded in the SSL stream though.
1140 <title id="secure"><application>Privoxy</application> runs as a <quote>server</quote>. How
1141 secure is it? Do I need to take any special precautions?</title>
1143 There are no known exploits that might effect
1144 <application>Privoxy</application>. On Unix-like systems,
1145 <application>Privoxy</application> can run as a non-privileged
1146 user, which is how we recommend it be run. Also, by default
1147 <application>Privoxy</application> only listens to requests
1148 from <quote>localhost</quote>. It is not itself directly exposed to the
1149 Internet in this configuration. If you want to have
1150 <application>Privoxy</application> serve as a LAN proxy, this will have to
1151 be opened up to allow for LAN requests. In this case, we'd recommend
1152 you specify only the LAN gateway address, e.g. 192.168.1.1 in the main
1153 <application>Privoxy</application> config file. All LAN hosts can then use
1154 this as their proxy address in the browser proxy configuration. In this way,
1155 <application>Privoxy</application> will not listen on any external ports.
1156 Of course, a firewall is always good too. Better safe than sorry.
1161 <sect3 id="turnoff">
1162 <title>How can I temporarily disable <application>Privoxy</application>?</title>
1164 The easiest way is to access <application>Privoxy</application> with your
1165 browser by using the special URL: <ulink url="http://p.p/">http://p.p/</ulink>
1166 and select "Toggle Privoxy on or off" from that page.
1174 <!-- ~~~~~ New section ~~~~~ -->
1177 <title id="trouble">Troubleshooting</title>
1180 <title id="refused">I just upgraded and am getting <quote>connection refused</quote>
1181 with every web page?</title>
1183 Either <application>Privoxy</application> is not running, or your
1184 browser is configured for a different port than what
1185 <application>Privoxy</application> is using.
1189 The old <application>Privoxy</application> (and also
1190 <application>Junkbuster</application>) used port 8000 by
1191 default. This has been changed to port 8118 now, due to a conflict
1192 with NAS (Network Audio Service), which uses port 8000. If you haven't,
1193 you need to change your browser to the new port number, or alternately
1194 change <application>Privoxy's</application> <quote>listen-address</quote>
1195 setting in the <filename>config</filename> file used to start
1196 <application>Privoxy</application>.
1202 <title id="flushit">I just added a new rule, but the steenkin ad is
1203 still getting through. How?</title>
1205 If the ad had been displayed before you added its URL, it will probably be
1206 held in the browser's cache for some time, so it will be displayed without
1207 the need for any request to the server, and <application>Privoxy</application>
1208 will not be in the picture. The best thing to do is try flushing the browser's
1209 caches. And then try again.
1213 If this doesn't help, you probably have an error in the rule you
1214 applied. Try pasting the full URL of the offending ad into <ulink
1215 url="http://www.privoxy.org/config/show-url-info">http://www.privoxy.org/config/show-url-info</ulink>
1216 and see if any actions match your new rule.
1222 <title id="badsite">One of my favorite sites does not work with <application>Privoxy</application>.
1223 What can I do?</title>
1226 First verify that it is indeed a <application>Privoxy</application> problem,
1227 by disabling <application>Privoxy</application> filtering and blocking.
1228 Go to <ulink url="http://p.p/">http://p.p/</ulink> and click on
1229 <quote>Toggle Privoxy On or Off</quote>, then disable it. Now try that
1234 If still a problem, go to <quote>Show which actions apply to a URL and
1235 why</quote> from <ulink url="http://p.p/">http://p.p/</ulink> and paste
1236 the full URL of the page in question into the prompt. See which actions are
1237 being applied to the URL. Now, armed with this information, go to <quote>Edit
1238 the actions list</quote>. Here you should see various sections that have
1239 various <application>Privoxy</application> features disabled for specific
1240 sites. Disabled <quote>actions</quote> will have a <quote>-</quote> (minus
1241 sign) in front of them. Add your problem page URL to one of these sections
1242 that looks like it is disabling the feature that is causing the
1243 problem. Re-try the page. There might be some trial and error involved. This
1244 is discussed in a little more detail in the <ulink
1245 url="../user-manual/appendix.html#ACTIONSANAT">user-manual
1251 Alternately, if you are comfortable with a text editor, you can accomplish
1252 the same thing by editing the appropriate <quote>actions</quote> file.
1258 <title id="time">What time is it?</title>
1269 <!-- ~~~~~ New section ~~~~~ -->
1271 FIXME: Commented out until we have something to put here. HB 03/18/02.
1272 <sect1 id="knownissues"><title>Known Issues</title>
1279 <!-- ~~~~~ New section ~~~~~ -->
1282 This is referenced in the doc header already. HB 03/25/02
1284 <sect1 id="contact"><title>Contact the developers</title>
1285 <para>Please see the user manual for information on how to contact the developers.
1289 <!-- ~~~~~ New section ~~~~~ -->
1290 <sect1 id="copyright"><title>Copyright and History</title>
1291 <para>Please see the user manual for information on Copyright and History.
1295 <!-- ~~~~~ New section ~~~~~ -->
1296 <sect1 id="seealso"><title>See also</title>
1297 <para>Please see the user manual for information on references.
1303 Tue 09/11/01 06:38:14 PM EST: Test SGML doc by Hal Burgiss.
1305 Last modified: Mon Sep 10 19:22:09 CEST 2001
1307 This program is free software; you can redistribute it
1308 and/or modify it under the terms of the GNU General
1309 Public License as published by the Free Software
1310 Foundation; either version 2 of the License, or (at
1311 your option) any later version.
1313 This program is distributed in the hope that it will
1314 be useful, but WITHOUT ANY WARRANTY; without even the
1315 implied warranty of MERCHANTABILITY or FITNESS FOR A
1316 PARTICULAR PURPOSE. See the GNU General Public
1317 License for more details.
1319 The GNU General Public License should be included with
1320 this file. If not, you can view it at
1321 http://www.gnu.org/copyleft/gpl.html
1322 or write to the Free Software Foundation, Inc., 59
1323 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
1326 Revision 1.31 2002/03/26 22:29:55 swa
1327 we have a new homepage!
1329 Revision 1.30 2002/03/25 16:39:22 hal9
1330 A few new sections. Made all links relative to user-manual.
1332 Revision 1.29 2002/03/25 05:23:57 hal9
1333 Moved section, and touch ups.
1335 Revision 1.28 2002/03/25 04:27:33 hal9
1336 New section related to name change.
1338 Revision 1.25 2002/03/24 16:08:08 swa
1339 we are too lazy to make a block-built
1340 privoxy logo. hence removed the option.
1342 Revision 1.24 2002/03/24 15:46:20 swa
1343 name change related issue.
1345 Revision 1.23 2002/03/24 12:33:01 swa
1348 Revision 1.22 2002/03/24 11:51:00 swa
1349 name change. changed filenames.
1351 Revision 1.21 2002/03/24 11:01:06 swa
1354 Revision 1.20 2002/03/23 15:13:11 swa
1355 renamed every reference to the old name with foobar.
1356 fixed "application foobar application" tag, fixed
1357 "the foobar" with "foobar". left junkbustser in cvs
1358 comments and remarks to history untouched.
1360 Revision 1.19 2002/03/21 17:01:54 hal9
1363 Revision 1.18 2002/03/18 16:40:31 hal9
1366 Revision 1.17 2002/03/18 03:53:53 hal9
1369 Revision 1.16 2002/03/17 21:32:56 hal9
1370 A few more additions.
1372 Revision 1.15 2002/03/17 07:25:59 hal9
1373 Correcting some of my typos, and some additions.
1375 Revision 1.14 2002/03/17 02:39:13 hal9
1376 A little more added ...
1378 Revision 1.13 2002/03/17 00:22:20 hal9
1379 Adding new stuff, and trying to incorporate stuff from old faq.
1381 Revision 1.12 2002/03/11 20:13:21 swa
1384 Revision 1.11 2002/03/11 18:42:27 swa
1387 Revision 1.10 2002/03/11 13:13:27 swa
1388 correct feedback channels
1390 Revision 1.9 2002/03/10 23:34:04 swa
1391 more info on not hiding ip address
1393 Revision 1.8 2002/03/09 15:55:48 swa
1394 added default config section
1396 Revision 1.7 2002/03/07 18:16:55 swa
1399 Revision 1.6 2002/03/07 13:16:31 oes
1400 Committing changes by Stefan
1402 Revision 1.5 2002/03/02 15:50:04 swa
1403 2.9.11 version. more input for docs.
1405 Revision 1.4 2002/02/24 14:34:24 jongfoster
1406 Formatting changes. Now changing the doctype to DocBook XML 4.1
1407 will work - no other changes are needed.
1409 Revision 1.3 2001/09/23 10:13:48 swa
1410 upload process established. run make webserver and
1411 the documentation is moved to the webserver. documents
1412 are now linked correctly.
1414 Revision 1.2 2001/09/13 15:20:17 swa
1415 merged standards into developer manual
1417 Revision 1.1 2001/09/12 15:36:41 swa
1418 source files for junkbuster documentation
1420 Revision 1.3 2001/09/10 17:43:59 swa
1421 first proposal of a structure.
1423 Revision 1.2 2001/06/13 14:28:31 swa
1424 docs should have an author.
1426 Revision 1.1 2001/06/13 14:20:37 swa
1427 first import of project's documentation for the webserver.