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7 File : $Source: /cvsroot/ijbswa/current/doc/source/faq.sgml,v $
10 This file belongs into
11 ijbswa.sourceforge.net:/home/groups/i/ij/ijbswa/htdocs/
13 $Id: faq.sgml,v 1.36 2002/03/31 23:18:47 hal9 Exp $
15 Written by and Copyright (C) 2001 the SourceForge
16 Privoxy team. http://www.privoxy.org/
18 Based on the Internet Junkbuster originally written
19 by and Copyright (C) 1997 Anonymous Coders and
20 Junkbusters Corporation. http://www.junkbusters.com
28 <title>Privoxy Frequently Asked Questions</title>
30 <pubdate>$Id: faq.sgml,v 1.36 2002/03/31 23:18:47 hal9 Exp $</pubdate>
35 <orgname>By: Privoxy Developers</orgname>
44 This is here to keep vim syntax file from breaking :/
45 If I knew enough to fix it, I would.
46 PLEASE DO NOT REMOVE! HB: hal@foobox.net
51 This FAQ gives users and developers alike answers to frequently asked
52 questions about <ulink url="http://www.privoxy.org">Privoxy</ulink>.
55 <application>Privoxy</application> is a web proxy with advanced filtering
56 capabilities for protecting privacy, filtering web page content, managing
57 cookies, controlling access, and removing ads, banners, pop-ups and other
58 obnoxious Internet junk. <application>Privoxy</application> has a very
59 flexible configuration and can be customized to suit individual needs and
60 tastes. <application>Privoxy</application> has application for both
61 stand-alone systems and multi-user networks.
64 <application>Privoxy</application> is based on the code of the
65 <application>Internet Junkbuster</application>.
66 <application>Junkbuster</application> was originally written by JunkBusters
67 Corporation, and was released as free open-source software under the GNU GPL.
68 Stefan Waldherr made many improvements, and started the SourceForge project
69 to continue development.
73 You can find the latest version of the document at <ulink url="http://www.privoxy.org/faq/">http://www.privoxy.org/faq/</ulink>.
74 Please see the Contact section in the
75 <ulink url="http://www.privoxy.org/user-manual/contact.html">user-manual</ulink> if you want to contact the developers.
79 <!-- Feel free to send a note to the developers at <email>ijbswa-developers@lists.sourceforge.net</email>. -->
85 <!-- ~~~~~ New section ~~~~~ -->
88 <sect1 id="introduction"><title>Introduction</title>
94 <!-- ~~~~~ New section ~~~~~ -->
96 <sect1 id="questions"><title>Frequently Asked Questions</title>
98 <!-- ~~~~~ New section ~~~~~ -->
100 <sect2 id="general"><title>General Information</title>
102 <sect3 id="newjb"><title>What is this new version of <application>Privoxy</application>?</title>
104 The original <application>Internet Junkbuster</application> (tm) is a
105 copyrighted product of <ulink url="http://www.junkbusters.com">Junkbusters
106 Corporation</ulink>. Development of this effort stopped some time ago as of
107 version 2.0.2. Stefan Waldherr started the ijbswa project on <ulink
108 url="http://sourceforge.net/projects/ijbswa/">Sourceforge</ulink> to rekindle
109 development. Other developers subsequently joined with Stefan, and have
110 since added many new features, refinements and enhancements. The result
111 of this effort is <application>Privoxy</application>.
114 <application>Privoxy</application> started with the
115 <application>Junkbuster 2.0.2</application> code base, but has advanced
116 significantly at this point.
123 <title id="whyprivoxy">Why <quote>Privoxy</quote>? Why a name change at all?</title>
125 <application>Privoxy</application> is the
126 <quote><emphasis>Privacy Enhancing Proxy</emphasis></quote>.
129 There are possible legal complications from the continued use of the
130 <application>Junkbuster</application> name, which is a trademark of
131 <ulink url="http://junkbusters.com">Junkbusters Corporation</ulink>.
132 (There are, however, no objections from Junkbusters Corporation to the
133 <application>Privoxy</application> project itself, and they, in fact, still
134 share our ideals and goals.)
138 The developers also believed that there so many changes from the original
139 code, that it was time to make a clean break from the past and make
140 a name in their own right, especially now with the pending release of
147 <sect3 id="differs"><title>How does <application>Privoxy</application> differ
148 from the old <application>Junkbuster?</application></title>
150 <application>Privoxy</application> picks up where
151 <application>Junkbuster</application> left off. All the old features remain.
152 The new <application>Privoxy</application> still blocks ads and banners,
153 still manages cookies, and still helps protect your privacy. But, these are
154 all enhanced, and many new features have been added, all in the same vein.
157 The configuration has changed significantly as well. This is something that
158 users will notice right off the bat. The <quote>blocklist</quote> file does
159 not exist any more. This is replaced by <quote>actions</quote> files, such
160 as <filename>default.actions</filename>. This is where most of the per site
161 configuration is now.
166 <sect3 id="features"><title>What are some of the new features?</title>
168 Include newfeatures.sgml
174 <sect3 id="proxymoron"><title>What is a <quote>proxy</quote>? How does
175 <application>Privoxy</application> work? </title>
177 When you connect to a web site with <application>Privoxy</application>,
178 you are really connecting to your locally running version of
179 <application>Privoxy</application>. <application>Privoxy</application>
180 intercepts your requests for the web page, and relays that to the
181 <quote>real</quote> web site. The web site sends the HTTP data stream
182 back to <application>Privoxy</application>, where
183 <application>Privoxy</application> can work its magic before it
184 relays this data back to your web browser.
188 Since <application>Privoxy</application> sits between you and the
189 WWW, it is in a position to intercept and completely manage all web traffic and
190 HTTP content before it gets to your browser.
191 <application>Privoxy</application> uses various programming methods to do
192 this, all of which is under your control via the various configuration
197 There are many kinds of proxies. <application>Privoxy</application> best
198 fits the <quote>filtering proxy</quote> category.
205 <title id="knows">How does <application>Privoxy</application> know what is
206 an ad, and what is not?</title>
208 <application>Privoxy</application> processes all the raw content of every
209 web page. So it reads everything on each page. It then compares this to the
210 rules as set up in the configuration files, and looks for any matches to
211 these rules. <application>Privoxy</application> makes heavy use of
212 <quote>regular expressions</quote>. (If you are not familiar with regular
213 expressions, it is explained briefly in <ulink
214 url="../user-manual/appendix.html">the user manual</ulink>.) Regular
215 expressions facilitate matching of one text string against another, using
216 wildcards to build complex patterns. So <application>Privoxy</application>
217 will typically look for URLs and other content that match certain key words
218 and expressions as defined in the configuration files. For instance a URL
219 that contains <quote>/banners</quote>, has a high probability of containing
220 ad banners, and thus would be a prime candidate to have a matching rule.
223 So <application>Privoxy</application> will look for these kinds of obvious
224 looking culprits. And also, will use lists of known organizations that
225 specialize in ads. Again, using complex patterns to match as many potential
226 combinations as possible since there tend to be many, many variations used by
227 advertisers, and new ones are being introduced all the time.
232 <title id="mistakes">Can <application>Privoxy</application> make mistakes?
233 This does not sound very scientific.</title>
235 Actually, it's a black art ;-) And yes, it is always possible to have a broad rule
236 accidentally block something by mistake. There is a good chance you may run
237 into such a situation at some point. It is tricky writing rules to cover
238 every conceivable possibility, and not occasionally get false positives.
242 But this should not be a big concern since the
243 <application>Privoxy</application> configuration is very flexible, and
244 includes tools to help identify these types of situations so they can be
245 addressed as needed, allowing you to customize your installation.
246 (<link linkend="badsite">See the appendix below</link>.)
252 <sect3 id="browsers2"><title>My browser does the same things as
253 <application>Privoxy</application>. Why should I use
254 <application>Privoxy</application> at all?</title>
256 Modern browsers do indeed have <emphasis>some</emphasis> of the same
257 functionality as <application>Privoxy</application>. Maybe this is
258 adequate for you. But <application>Privoxy</application> is much more
259 versatile and powerful, and can do a number of things that browsers just can't.
262 In addition, a proxy is good choice if you use multiple browsers, or
263 have a LAN with multiple computers. This way all the configuration
264 is in one place, and you don't have to maintain a similar configuration
265 for possibly many browsers.
272 <sect3 id="license"><title>Is there is a license or fee? What about a
273 warranty? Registration?</title>
275 <application>Privoxy</application> is licensed under the
276 GNU General Public License (GPL). It is free to use, copy,
277 modify or distribute as you wish under the terms of this license.
279 url="http://www.gnu.org/copyleft/gpl.html">http://www.gnu.org/copyleft/gpl.html</ulink>
283 There is no warranty of any kind, expressed, implied or otherwise. That is
284 something that would cost real money ;-) There is no registration either.
285 <application>Privoxy</application> really is <emphasis>free</emphasis>
291 <sect3 id="jointeam"><title>I would like to help you, what do I do?</title>
293 <sect4 id="jointeam-money"><title>Money Money Money</title>
295 We, of course, welcome donations and use the money for domain registering,
296 regular world-wide get-togethers (hahaha). Anyway, we'll soon describe the
297 process how to donate money to the team.
301 <sect4 id="jointeam-work"><title>You want to work with us?</title>
303 Well, helping the team is always a good idea. We welcome new developers,
304 RPM gurus or documentation makers. Simply get an account on sourceforge.net
305 and mail your id to the developer mailing list. Then read the
306 section Quickstart in the <ulink url="http://privoxy.org/developer-manual/quickstart.html">
307 Developer's Manual</ulink>.
310 Once we have added you to the team, you'll have write access to the CVS
311 repository, and together we'll find a suitable task for you.
320 <!-- ~~~~~ New section ~~~~~ -->
322 <sect2 id="installation"><title>Installation</title>
324 <sect3 id="whichbrowsers">
325 <title>Which browsers are supported by <application>Privoxy</application>?</title>
327 Any browser that can be configured to use a <quote>proxy</quote>, which
328 should be virtually all browsers. Direct browser support is not necessary
329 since <application>Privoxy</application> runs as a separate application and
330 just exchanges standard HTML data with your browser, just like a web server
336 <title>Which operating systems are supported?</title>
338 Include supported.sgml here:
343 <sect3 id="newinstall"><title>Can I install
344 <application>Privoxy</application> over <application>Junkbuster</application>?</title>
346 We recommend you uninstall <application>Junkbuster</application>
347 first to minimize conflicts and confusion. You may want to
348 save your old configuration files for future reference. The configuration
349 is substantially changed.
353 url="../user-manual/index.html">user-manual</ulink> for
354 platform specific installation instructions. [FIXME: This is meant for after
355 the name change for 3.0!]
358 Note: Some installers may automatically uninstall
359 <application>Junkbuster</application>, if present!
365 <title id="firststep">I just installed <application>Privoxy</application>. Is there anything
366 special I have to do now?</title>
369 All browsers must be told to use <application>Privoxy</application>
370 as a proxy by specifying the correct proxy address and port number
371 in the appropriate configuration area for the browser. See below.
372 Also, you should flush your browser's memory and disk cache to get rid of any
380 <sect3 id="localhost"><title>What is the proxy address of <application>Privoxy</application>?</title>
382 If you set up the <application>Privoxy</application> to run on
383 the computer you browse from (rather than your ISP's server or some
384 networked computer on a LAN), the proxy will be on <quote>localhost</quote>
385 (which is the special name used by every computer on the Internet to refer
386 to itself) and the port will be 8118 (unless you have <application>Privoxy</application> to run on a different port with the
387 <emphasis>listen-address</emphasis> config option).
390 When configuring your browser's proxy settings you typically enter
391 the word <quote>localhost</quote> in the boxes next to <quote>HTTP</quote>
392 and <quote>Secure</quote> (HTTPS) and then the number <quote>8118</quote>
393 for <quote>port</quote>. This tells your browser to send all web
394 requests to <application>Privoxy</application> instead of directly to the
398 <application>Privoxy</application> can also be used to proxy for
399 a Local Area Network. In this case, your would enter either the IP
400 address of the LAN host where <application>Privoxy</application>
401 is running, or the equivalent hostname. Port assignment would be
405 <application>Privoxy</application> does not currently handle
406 protocols such as FTP, SMTP, IM, IRC, ICQ, or other Internet
412 <title id="nothing">I just installed <application>Privoxy</application>, and nothing is happening.
413 All the ads are there. What's wrong?</title>
416 Did you configure your browser to use <application>Privoxy</application>
417 as a proxy? It does not sound like it. See above. You might also try flushing
418 the browser's caches to force a full re-reading of pages. You can verify
419 that <application>Privoxy</application> is running, and your browser
420 is correctly configured by entering the special URL:
421 <ulink url="http://p.p/">http://p.p/</ulink>. This should give you
422 a banner that says <quote>This is Privoxy</quote> and
423 access to <application>Privoxy's</application> internal configuration.
424 If you see this, then you are good to go. If not, the browser or
425 <application>Privoxy</application> are not set up correctly.
434 <!-- ~~~~~ New section ~~~~~ -->
436 <sect2 id="configuration"><title>Configuration</title>
438 <sect3 id="newconfig"><title>Can I use my old config files?</title>
440 There are major changes to <application>Junkbuster</application>,
441 <application>Privoxy</application>, configuration from version 2.0.x to
442 2.9.x and later. Most of the older files will not work at all. This is
443 especially true of <filename>blocklist</filename>. If this is the case, you
444 will need to re-enter your old data into the new configuration structure.
445 This is probably also a good recommendation even if upgrading from 2.9.x to
446 3.x since there were many minor changes along the way.
451 <title id="actionsfile">What is an <quote>actions</quote> file?</title>
454 <quote>actions</quote> files are where various actions that
455 <application>Privoxy</application> might take, are configured.
456 Typically, you would define a set of default actions that apply
457 to all URLs, then add exceptions to these defaults.
461 Actions can be defined on a per site basis, or for groups of sites. Actions
462 can also be grouped together and then applied to one or more sites. There
463 are many possible actions that might apply to any given site. As an example,
464 if we are blocking cookies as one of our default
465 <application>actions</application>, but need to accept cookies from a given
466 site, we would define this in our <quote>actions</quote> file.
471 <application>Privoxy</application> comes with several default
472 <application>actions</application> files, with varying degrees
473 of filtering and blocking, as starting points for your own
474 configuration (see below).
479 <sect3 id="actionss">
480 <title>The <quote>actions</quote>concept confuses me. Please list
481 some of these <quote>actions</quote>.</title>
483 These are all explained in the
484 <ulink url="../user-manual/configuration.html#ACTIONSFILE">user-manual</ulink>.
485 Please refer to that.
491 <title id="actconfig">How are actions files configured? What is the easiest
492 way to do this?</title>
495 The easiest way to do this, is to access <application>Privoxy</application>
496 with your web browser at <ulink url="http://p.p/">http://p.p/</ulink>,
498 "<ulink url="http://config.privoxy.org">Edit the actions list</ulink>"
499 from the selection list. You can also do this by editing the appropriate
500 file with a text editor.
506 url="../user-manual/configuration.html#ACTIONSFILE">user-manual</ulink> for a
507 detailed explanation of these and other configuration files, and their
508 various options and syntax.
514 FIXME: Commenting these out until we have some data there. HB 03/17/02.
516 <sect3 id="yahoo"><title>How can I make my Yahoo account work?</title>
522 <sect3 id="hotmail"> <title>How can I make my Hotmail account work?</title>
528 <sect3 id="gmx"> <title>How can I make my GMX account work?</title>
535 <sect3 id="configfiles"> <title>What are the differences between
536 intermediate.action, basic.action, etc.?</title>
538 Configuring <application>Privoxy</application> is not easy. To help you get
539 started, we provide you with three different default configurations. The
540 following table shows you, which features are enabled in each configuration.
543 <table frame=all><title>Default Configurations</title>
544 <tgroup cols=5 align=left colsep=1 rowsep=1>
552 <entry>Feature</entry>
553 <entry>default.action</entry>
554 <entry>basic.action</entry>
555 <entry>intermediate.action</entry>
556 <entry>advanced.action</entry>
562 <!-- <entry>f1</entry> -->
563 <!-- <entry>f2</entry> -->
564 <!-- <entry>f3</entry> -->
565 <!-- <entry>f4</entry> -->
566 <!-- <entry>f5</entry> -->
573 <entry>ad-filtering</entry>
581 <entry>blank image</entry>
589 <entry>de-animate GIFs</entry>
597 <entry>referer forging</entry>
605 <entry>jon's +no-cookies-keep (i.e. session cookies only)</entry>
613 <entry>no-popup windows</entry>
621 <entry>fast redirects</entry>
629 <entry>hide-referrer</entry>
637 <entry>hide-useragent</entry>
645 <entry>content-modification</entry>
653 <entry>feature-x</entry>
661 <entry>feature-y</entry>
669 <entry>feature-z</entry>
682 <sect3 id="browseconfig"> <title>Why can I change the configuration with a
683 browser? Does that not raise security issues?</title>
685 What I don't understand, is how I can browser edit the config file as a
686 regular user, while the whole /etc/privoxy hierarchy belongs to the user
687 "privoxy", with only 644 perms.
690 When you use the browser-based editor, <application>Privoxy</application>
691 itself is writing to the config files. Because
692 <application>Privoxy</application> is running as the user "privoxy", it can
693 update the config files.
696 If you don't like this, setting "enable-edit-actions 0" in the config file
697 will disable the browser-based editor. If you're that paranoid, you should
698 also consider setting "enable-remote-toggle 0" to prevent browser-based
699 enabling/disabling of <application>Privoxy</application>.
702 Note that normally only local users can connect to <application>Privoxy</application>, so this is not
703 (normally) a security problem.
709 <title id="filterfile">What is <quote>default.filter</quote>?</title>
711 The <quote>default.filter</quote> file is used to <quote>filter</quote> any
712 web page content. By <quote>filtering</quote> we mean it can modify, remove,
713 or change <emphasis>anything</emphasis> on the page, including HTML tags, and
714 JavaScript. Regular expressions are used to accomplish this, and operate
715 on a line by line basis. This is potentially a very powerful feature, but
716 requires some expertise.
720 If you are familiar with regular expressions, and HTML, you can look at
721 the provided <filename>default.filter</filename> with a text editor and see
722 some of things it can be used for.
726 Presently, there is no GUI editor option for this part of the configuration,
727 but you can disable/enable various sections of the included default
728 file with the <quote>Actions List Editor</quote> from your browser.
734 <title id="lanconfig">How can I set up <application>Privoxy</application> to act as a proxy for my
737 By default, <application>Privoxy</application> only responds to requests
738 from localhost. To have it act as a server for a network, this needs to be
739 changed in the main config file where the <application>Privoxy</application>
740 configuration is located. In that file is a <quote>listen-address</quote>
741 option. It may be commented out with a <quote>#</quote> symbol. Make sure
742 it is uncommented, and assign it the address of the LAN gateway interface,
743 and port number to use:
748 listen-address 192.168.1.1:8118
753 Save the file, and restart <application>Privoxy</application>. Configure
754 all browsers on the network then to use this address and port number.
761 <title id="noseeum">Instead of ads, now I get a checkerboard pattern. I don't want to see anything.</title>
763 This is a configuration option for images that
764 <application>Privoxy</application> is stopping. You have the choice <!-- of
765 the --> <!-- <application>Privoxy</application> logo, --> of a checkerboard
766 pattern, a transparent 1x1 GIF image (aka <quote>blank</quote>), or a custom
767 URL of your choice. Note that to fit this category, the URL must match both
768 the <quote>+image</quote> and <quote>+block</quote> actions.
772 If you want to see nothing, then change the <quote>+image-blocker</quote>
773 action to <quote>+image-blocker{blank}</quote>. This can be done from the
774 <quote>Edit Actions List</quote> selection at <ulink
775 url="http://p.p/">http://p.p/</ulink>. Or by hand editing the appropriate
776 actions file. This will only effect what is defined as <quote>images</quote>
777 though. Also, some URLs that generate the bright red <quote>Blocked</quote>
778 banner, can be moved to the <quote>+image-blocker</quote> section for the
779 same reason, but there are some limits and risks to this (see below).
786 <title id="whyseeum">Why would anybody want to see a checkerboard pattern?</title>
788 This can be helpful for troubleshooting problems. It might also be good
789 for anyone new to <application>Privoxy</application> so that they can
790 see if their favorite pages are displaying correctly, and
791 <application>Privoxy</application> is not inadvertently removing something
798 <title id="blockedisugly">I see large red banners on some pages that say
799 <quote>Blocked</quote>. Why and how do I get rid of this?</title>
801 These are URLs that match something in one of
802 <application>Privoxy's</application> block actions (+block). It is meant
803 to be a warning so that you know something has been blocked and an easy way
804 for you to see why. These are handled differently than what has been defined
805 explicitly as <quote>images</quote> (e.g. ad banners). Depending on the
806 URL itself, it is sometimes hard for <application>Privoxy</application> to
807 really know whether there is indeed an ad image there or not. And there are
808 limitations as to what <application>Privoxy</application> can do to
809 <quote>fool</quote> the browser.
813 For instance, if the ad is in a frame, then it is embedded in the separate
814 HTML page used for the frame. In this case, you cannot just substitute an
815 aribitray image (like we would for a <quote>blank</quote> image), for an HTML
816 page. The browser is expecting an HTML page, and that is what it must have
817 for frames. So this situation can be a little trickier to deal with, and
818 <application>Privoxy</application> will use the <quote>Blocked</quote> page.
822 If you want these to be treated as if they were images, so that they can be
823 made invisible, you can try moving the offending URL from the
824 <quote>+block</quote> section to the <quote>+imageblock</quote> section of
825 your actions file. Just be forewarned, if any URL is made
826 <quote>invisible</quote>, you may not have any inkling that something has
827 been removed from that page, or why. If this approach does not work, then you are
828 probably dealing with a frame (or <quote>ilayer</quote>), and the only thing
829 that can go there is an HTML page of some sort.
832 To deal with this situation, you could modify the
833 <quote><filename>block</filename></quote> HTML template that is used by
834 <application>Privoxy</application> to display this, and make it something
835 more to your liking. Currently, there is no configuration option for this.
836 You will have to modify, or create your own page, and use this to replace
837 <filename>templates/blocked</filename>, which is what
838 <application>Privoxy</application> uses to display the <quote>Blocked</quote>
842 Another way to deal with this is find why and where
843 <application>Privoxy</application> is blocking the frame, and
844 diable this. Then let the <quote>+image-blocker</quote> action
845 handle the ad that is embedded in the frame's HTML page.
850 <sect3 id="alliseeisred">
851 <title>I cannot see all of the <quote>Blocked</quote> page banner. All I
852 see is a bright red square.</title>
854 There is not enough space to fit the entire page. Try right clicking on the
855 visible, red portion, and select <quote>Show Frame</quote>, or equivalent.
856 This will usually allow you to see the entire Privoxy <quote>Blocked</quote>
857 page, and from there you can see just what is being blocked, and why.
861 <sect3 id="otherproxy">
862 <title>How can I make <application>Privoxy</application> work with other
863 proxies like <application>Squid</application>?</title>
865 This can be done. See the <ulink
866 url="../user-manual/configuration.html#FORWARDING">user manual</ulink>,
867 which describes how to do this.
875 <!-- ~~~~~ New section ~~~~~ -->
877 <sect2 id="misc"><title>Miscellaneous</title>
880 <title id="slowsme">How much does <application>Privoxy</application> slow my browsing down? This
881 has to add extra time to browsing.</title>
883 It should not slow you down any in real terms, and may actually help
884 speed things up since ads, banners and other junk are not being displayed.
885 The actual processing time required by <application>Privoxy</application>
886 itself for each page, is relatively small in the overall scheme of things,
887 and happens very quickly. This is typically more than offset by time saved
888 not downloading and rendering ad images.
892 <quote>Filtering</quote> via the <filename>filterfile</filename>
893 mechanism may cause a perceived slowdown, since the entire page is buffered
894 before displaying. See below.
901 <sect3 id="loadingtimes"><title>I noticed considerable
902 delays in page requests compared to the old Junkbuster. What's wrong?</title>
904 Using the default filtering configuration, I noticed considerable delays in
905 page requests compared to the old Junkbuster. Loading pages with large contents
906 seemed to take forever, then suddenly delivering all the content at once.
909 The whole content must be loaded in order to filter, and nothing is is
910 sent to the browser during this time. The loading time does not really
911 change in real numbers, but the feeling is different, because most
912 browsers are able to start rendering incomplete content, giving the
913 user a feeling of "it works".
916 To modify the content of a page (i.e. make frames resizeable again, etc.) and
917 not just replace ads, <application>Privoxy</application> needs to download the
918 entire page first, do its content magic and then send the page to the browser.
923 <sect3 id="configurl"><title>What is the "http://p.p/"?</title>
925 Since <application>Privoxy</application> sits between your web browser and the Internet, it can be
926 programmed to handle certain pages specially.
930 With recent versions of <application>Privoxy</application> (version 2.9.x), you can get some
931 information about <application>Privoxy</application> and change some settings by going to
932 <ulink url="http://p.p/">http://p.p/</ulink> or, equivalently, <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
933 (Note that p.p is far easier to type but may not work in some
934 configurations. With the name change to <application>Privoxy</application>,
935 this is changed from the previous http://i.j.b/ or earlier 2.9.x versions).
939 These pages are <emphasis>not</emphasis> forwarded to a server on the Internet
940 - instead they are handled by a special web server which is built in to
941 <application>Privoxy</application>.
945 If you are not running <application>Privoxy</application>, then <ulink
946 url="http://p.p/">http://p.p/</ulink> will fail, and <ulink
947 url="http://config.privoxy.org/">http://config.privoxy.org/</ulink> will
948 return a web page telling you you're not running
949 <application>Privoxy</application>.
953 If you have version 2.0.2, then the equivalent is
954 http://example.com/show-proxy-args (but you get far less information, and you
955 should really consider upgrading to 2.9.x).
960 FIXME: commented out until we have data. HB 03/18/02.
962 <sect3 id="badfiledesc"><title>I get the message 'Bad File Descriptor', why?</title>
968 <sect3 id="proxy-chaining"><title>How do I chain <application>Privoxy</application> with other proxies
969 (e.g. squid)?</title>
976 <sect3 id="blocklist"><title>Do you still maintain the blocklists?</title>
978 No. The format of the blocklists has changed significantly in the versions
979 2.9.x. Once we have released the new stable version, v3.0, there will
980 again be blocklists that you can update automatically.
984 <sect3 id="newads"><title>How can I submit new ads?</title>
986 As of now, please discontinue to submit new ad blocking infos. Once we
987 have released the new version, there will again be a form on the website,
988 which you can use to contribute new ads.
992 <sect3 id="ip"><title>How can I hide my IP address?</title>
994 You cannot hide your IP address with <application>Privoxy</application> or any other software, since
995 the server needs to know your IP address to send the answer to you.
998 Fortunately there are many publicly usable anonymous proxies out there, which
999 solve the problem by providing a further level of indirection between you and
1000 the web server, shared by many people and thus letting your requests "drown"
1001 in white noise of unrelated requests as far as user tracking is concerned.
1004 Most of them will, however, log your IP address and make it available to the
1005 authorities in case you abuse that anonymity for criminal purposes. In fact
1006 you can't even rule out that some of them only exist to *collect* information
1007 on (those suspicious) people with a more than average preference for privacy.
1010 You can find a list of anonymous public proxies at <ulink
1011 url="http://www.multiproxy.org/anon_list.htm">multiproxy.org</ulink> and many
1012 more through Google.
1016 <!-- <sect3 id="image"><title>What is the imagefile (simage.ini, etc.) for?</title> -->
1018 <!-- Anytime <application>Privoxy</application> determines (with the help of the blocklist) that a URL -->
1019 <!-- contains an advertisement, it has to decide whether this advertisement is an -->
1020 <!-- image or not. <application>Privoxy</application> uses the imagefile for that purpose. -->
1025 <title id="anonforsure">Can <application>Privoxy</application> guarantee I am anonymous?</title>
1027 No. Your chances of remaining anonymous are greatly improved, but unless you
1028 are an expert on Internet security it would be safest to assume that
1029 everything you do on the Web can be traced back to you.
1032 <application>Privoxy</application> can remove various information about you,
1033 and allows <emphasis>you</emphasis> more freedom to decide which sites
1034 you can trust. But it's still possible that web sites can find out who you
1035 are. Here's one way this can happen.
1038 A few browsers disclose the user's email address in certain situations, such
1039 as when transferring a file by FTP. <application>Privoxy</application>
1040 does not filter FTP. If you need this feature, or are concerned about the
1041 mail handler of your browser disclosing your email address, you might
1042 consider products such as <application>NSClean</application>.
1045 Browsers available only as binaries could use non-standard headers to give
1046 out any information they can have access to: see the manufacturer's license
1047 agreement. It's impossible to anticipate and prevent every breach of privacy
1048 that might occur. The professionally paranoid prefer browsers available as
1049 source code, because anticipating their behavior is easier. Trust the source,
1056 <title id="sitebreak">Might some things break because header information is
1057 being altered?</title>
1060 Definitely. More and more sites use HTTP header content to decide what to
1061 display and how to display it. There is many ways that this can be handled,
1062 so having hard and fast rules, is tricky.
1066 <quote>USER AGENT</quote> in particular is often used in this way to identify
1067 the browser, and adjust content accordingly. Changing this now is not
1068 recommended, since so many sites do look for this. You may get undesirable
1069 results by changing this.
1073 For instance, different browsers use different encodings of Russian and Czech
1074 characters, certain web servers convert pages on-the-fly according to the
1075 User Agent header. Giving a <quote>User Agent</quote> with the wrong
1076 operating system or browser manufacturer causes some sites in these languages
1077 to be garbled; Surfers to Eastern European sites should change it to
1078 something closer. And then some page access counters work by looking at the
1079 <quote>REFERER</quote> header; they may fail or break if unavailable. The
1080 weather maps of Intellicast have been blocked by their server when no
1081 <quote>REFERER</quote> or cookie is provided, is another example. There are
1082 many, many other ways things can go wrong when trying to fool a web server.
1086 If you have problems with a site, you will have to adjust your configuration
1087 accordingly. Cookies are probably the most likely adjustment that may
1088 be required, but by no means the only one.
1096 <title id="caching">Can <application>Privoxy</application> act as a <quote>caching</quote> proxy to
1097 speed up web browsing?</title>
1099 No, it does not have this ability at all. You want something like
1100 <ulink url="http://www.squid-cache.org/">Squid</ulink> for this. And, yes,
1101 before you ask, <application>Privoxy</application> can co-exist
1102 with other kinds of proxies like <application>Squid</application>.
1107 <title id="firewall">What about as a firewall? Can <application>Privoxy</application> protect me?</title>
1109 Not in the way you mean, or in the way a true firewall can, or a proxy that
1110 has this specific capability. <application>Privoxy</application> can help
1111 protect your privacy, but not really protect you from intrusion attempts.
1117 <title id="logo">The <application>Privoxy</application> logo that replaces ads is very blocky
1118 and ugly looking. Can't a better font be used?</title>
1121 This is not a font problem. The logo is an image that is created by
1122 <application>Privoxy</application> on the fly. So as to not waste
1123 memory, the image is rather small. The blockiness comes when the
1124 image is scaled to fill a largish area. There is not much to be done
1125 about this, other than to use one of the other
1126 <quote>imageblock</quote> directives: <emphasis>pattern</emphasis>,
1127 <emphasis>blank</emphasis>, or a URL of your choosing.
1130 Given the above problem, we have decided to remove the logo option entirely
1137 <title id="wasted">I have large empty spaces now where ads used to be.
1140 It would be easy enough to just eliminate this space altogether, rather than
1141 fill it with blank space. But, this would create problems with many pages
1142 that use the overall size of the ad to help organize the page layout and
1143 position the various components of the page where they were intended to be.
1144 It is best left this way.
1150 <title id="ssl">How can <application>Privoxy</application> filter Secure (HTTPS) URLs?</title>
1152 This is a limitation since HTTPS transactions are encrypted SSL sessions
1153 between your browser and the secure site, and are meant to be reliably
1154 <emphasis>secure</emphasis> and private. This means that all cookies and HTTP
1155 header information are also encrypted from the time they leave your browser,
1156 to the site, and vice versa. <application>Privoxy</application> does not
1157 try to unencrypt this information, so it just passes through as is.
1158 <application>Privoxy</application> can still catch images and ads that
1159 are embedded in the SSL stream though.
1166 <title id="secure"><application>Privoxy</application> runs as a <quote>server</quote>. How
1167 secure is it? Do I need to take any special precautions?</title>
1169 There are no known exploits that might effect
1170 <application>Privoxy</application>. On Unix-like systems,
1171 <application>Privoxy</application> can run as a non-privileged
1172 user, which is how we recommend it be run. Also, by default
1173 <application>Privoxy</application> only listens to requests
1174 from <quote>localhost</quote>. The server aspect of
1175 <application>Privoxy</application> is not itself directly exposed to the
1176 Internet in this configuration. If you want to have
1177 <application>Privoxy</application> serve as a LAN proxy, this will have to
1178 be opened up to allow for LAN requests. In this case, we'd recommend
1179 you specify only the LAN gateway address, e.g. 192.168.1.1, in the main
1180 <application>Privoxy</application> config file. All LAN hosts can then use
1181 this as their proxy address in the browser proxy configuration. In this way,
1182 <application>Privoxy</application> will not listen on any external ports.
1183 Of course, a firewall is always good too. Better safe than sorry.
1188 <sect3 id="turnoff">
1189 <title>How can I temporarily disable <application>Privoxy</application>?</title>
1191 The easiest way is to access <application>Privoxy</application> with your
1192 browser by using the special URL: <ulink url="http://p.p/">http://p.p/</ulink>
1193 and select "Toggle Privoxy on or off" from that page.
1201 <!-- ~~~~~ New section ~~~~~ -->
1204 <title id="trouble">Troubleshooting</title>
1207 <title id="refused">I just upgraded and am getting <quote>connection refused</quote>
1208 with every web page?</title>
1210 Either <application>Privoxy</application> is not running, or your
1211 browser is configured for a different port than what
1212 <application>Privoxy</application> is using.
1216 The old <application>Privoxy</application> (and also
1217 <application>Junkbuster</application>) used port 8000 by
1218 default. This has been changed to port 8118 now, due to a conflict
1219 with NAS (Network Audio Service), which uses port 8000. If you haven't,
1220 you need to change your browser to the new port number, or alternately
1221 change <application>Privoxy's</application> <quote>listen-address</quote>
1222 setting in the <filename>config</filename> file used to start
1223 <application>Privoxy</application>.
1229 <title id="flushit">I just added a new rule, but the steenkin ad is
1230 still getting through. How?</title>
1232 If the ad had been displayed before you added its URL, it will probably be
1233 held in the browser's cache for some time, so it will be displayed without
1234 the need for any request to the server, and <application>Privoxy</application>
1235 will not be in the picture. The best thing to do is try flushing the browser's
1236 caches. And then try again.
1240 If this doesn't help, you probably have an error in the rule you
1241 applied. Try pasting the full URL of the offending ad into <ulink
1242 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
1243 and see if any actions match your new rule.
1249 <title id="badsite">One of my favorite sites does not work with <application>Privoxy</application>.
1250 What can I do?</title>
1253 First verify that it is indeed a <application>Privoxy</application> problem,
1254 by disabling <application>Privoxy</application> filtering and blocking.
1255 Go to <ulink url="http://p.p/">http://p.p/</ulink> and click on
1256 <quote>Toggle Privoxy On or Off</quote>, then disable it. Now try that
1257 page again. It's probably a good idea to flush the browser cache as well.
1261 If still a problem, go to <quote>Show which actions apply to a URL and
1262 why</quote> from <ulink url="http://p.p/">http://p.p/</ulink> and paste
1263 the full URL of the page in question into the prompt. See which actions are
1264 being applied to the URL. Now, armed with this information, go to <quote>Edit
1265 the actions list</quote>. Here you should see various sections that have
1266 various <application>Privoxy</application> features disabled for specific
1267 sites. Disabled <quote>actions</quote> will have a <quote>-</quote> (minus
1268 sign) in front of them. Add your problem page URL to one of these sections
1269 that looks like it is disabling the feature that is causing the
1270 problem. Re-try the page. There might be some trial and error involved. This
1271 is discussed in a little more detail in the
1272 <ulink url="../user-manual/appendix.html#ACTIONSANAT">user-manual
1278 Alternately, if you are comfortable with a text editor, you can accomplish
1279 the same thing by editing the appropriate <quote>actions</quote> file.
1285 <title>Where can I get help? Report bugs? Feature Requests? Etc?</title>
1287 Feedback is encouraged, whether good, bad or ugly. Please see the contact
1288 page in the <ulink url="../user-manual/contact.html">user-manual</ulink> for
1296 <title id="time">What time is it?</title>
1307 <!-- ~~~~~ New section ~~~~~ -->
1309 FIXME: Commented out until we have something to put here. HB 03/18/02.
1310 <sect1 id="knownissues"><title>Known Issues</title>
1317 <!-- ~~~~~ New section ~~~~~ -->
1320 This is referenced in the doc header already. HB 03/25/02
1322 <sect1 id="contact"><title>Contact the developers</title>
1323 <para>Please see the user manual for information on how to contact the developers.
1327 <!-- ~~~~~ New section ~~~~~ -->
1328 <sect1 id="copyright"><title>Copyright and History</title>
1331 <ulink url="../user-manual/copyright.html#HISTORY">user-manual</ulink> for
1332 information on Copyright and History.
1336 <!-- ~~~~~ New section ~~~~~ -->
1337 <sect1 id="seealso"><title>See also</title>
1340 <ulink url="../user-manual/seealso.html">user-manual</ulink> for
1347 Tue 09/11/01 06:38:14 PM EST: Test SGML doc by Hal Burgiss.
1349 Last modified: Mon Sep 10 19:22:09 CEST 2001
1351 This program is free software; you can redistribute it
1352 and/or modify it under the terms of the GNU General
1353 Public License as published by the Free Software
1354 Foundation; either version 2 of the License, or (at
1355 your option) any later version.
1357 This program is distributed in the hope that it will
1358 be useful, but WITHOUT ANY WARRANTY; without even the
1359 implied warranty of MERCHANTABILITY or FITNESS FOR A
1360 PARTICULAR PURPOSE. See the GNU General Public
1361 License for more details.
1363 The GNU General Public License should be included with
1364 this file. If not, you can view it at
1365 http://www.gnu.org/copyleft/gpl.html
1366 or write to the Free Software Foundation, Inc., 59
1367 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
1370 Revision 1.36 2002/03/31 23:18:47 hal9
1371 More on dealing with BLOCKED.
1373 Revision 1.35 2002/03/30 04:14:19 hal9
1374 Fix privoxy.org/config links.
1376 Revision 1.34 2002/03/29 04:35:56 hal9
1379 Revision 1.33 2002/03/29 01:31:48 hal9
1380 Several new Q/A's and other touch ups.
1382 Revision 1.32 2002/03/27 00:57:03 hal9
1383 Touch ups for name change.
1385 Revision 1.31 2002/03/26 22:29:55 swa
1386 we have a new homepage!
1388 Revision 1.30 2002/03/25 16:39:22 hal9
1389 A few new sections. Made all links relative to user-manual.
1391 Revision 1.29 2002/03/25 05:23:57 hal9
1392 Moved section, and touch ups.
1394 Revision 1.28 2002/03/25 04:27:33 hal9
1395 New section related to name change.
1397 Revision 1.25 2002/03/24 16:08:08 swa
1398 we are too lazy to make a block-built
1399 privoxy logo. hence removed the option.
1401 Revision 1.24 2002/03/24 15:46:20 swa
1402 name change related issue.
1404 Revision 1.23 2002/03/24 12:33:01 swa
1407 Revision 1.22 2002/03/24 11:51:00 swa
1408 name change. changed filenames.
1410 Revision 1.21 2002/03/24 11:01:06 swa
1413 Revision 1.20 2002/03/23 15:13:11 swa
1414 renamed every reference to the old name with foobar.
1415 fixed "application foobar application" tag, fixed
1416 "the foobar" with "foobar". left junkbustser in cvs
1417 comments and remarks to history untouched.
1419 Revision 1.19 2002/03/21 17:01:54 hal9
1422 Revision 1.18 2002/03/18 16:40:31 hal9
1425 Revision 1.17 2002/03/18 03:53:53 hal9
1428 Revision 1.16 2002/03/17 21:32:56 hal9
1429 A few more additions.
1431 Revision 1.15 2002/03/17 07:25:59 hal9
1432 Correcting some of my typos, and some additions.
1434 Revision 1.14 2002/03/17 02:39:13 hal9
1435 A little more added ...
1437 Revision 1.13 2002/03/17 00:22:20 hal9
1438 Adding new stuff, and trying to incorporate stuff from old faq.
1440 Revision 1.12 2002/03/11 20:13:21 swa
1443 Revision 1.11 2002/03/11 18:42:27 swa
1446 Revision 1.10 2002/03/11 13:13:27 swa
1447 correct feedback channels
1449 Revision 1.9 2002/03/10 23:34:04 swa
1450 more info on not hiding ip address
1452 Revision 1.8 2002/03/09 15:55:48 swa
1453 added default config section
1455 Revision 1.7 2002/03/07 18:16:55 swa
1458 Revision 1.6 2002/03/07 13:16:31 oes
1459 Committing changes by Stefan
1461 Revision 1.5 2002/03/02 15:50:04 swa
1462 2.9.11 version. more input for docs.
1464 Revision 1.4 2002/02/24 14:34:24 jongfoster
1465 Formatting changes. Now changing the doctype to DocBook XML 4.1
1466 will work - no other changes are needed.
1468 Revision 1.3 2001/09/23 10:13:48 swa
1469 upload process established. run make webserver and
1470 the documentation is moved to the webserver. documents
1471 are now linked correctly.
1473 Revision 1.2 2001/09/13 15:20:17 swa
1474 merged standards into developer manual
1476 Revision 1.1 2001/09/12 15:36:41 swa
1477 source files for junkbuster documentation
1479 Revision 1.3 2001/09/10 17:43:59 swa
1480 first proposal of a structure.
1482 Revision 1.2 2001/06/13 14:28:31 swa
1483 docs should have an author.
1485 Revision 1.1 2001/06/13 14:20:37 swa
1486 first import of project's documentation for the webserver.