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3 File : $Source: /cvsroot/ijbswa/current/doc/source/faq.sgml,v $
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9 $Id: faq.sgml,v 1.29 2002/03/25 05:23:57 hal9 Exp $
11 Written by and Copyright (C) 2001 the SourceForge
12 PRIVOXY team. http://ijbswa.sourceforge.net
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 1.29 2002/03/25 05:23:57 hal9 Exp $</pubdate>
28 <orgname>By: Privoxy Developers</orgname>
35 The FAQ document gives users and developers alike answers to frequently asked
37 <application>Privoxy</application>. <application>Privoxy</application> is a web
38 proxy with advanced filtering capabilities for protecting privacy, filtering
39 web page content, managing cookies, controlling access, and removing ads,
40 banners, pop-ups and other obnoxious Internet
41 Junk. <application>Privoxy</application> has a very flexible configuration and
42 can be customized to suit individual needs and
43 tastes. <application>Privoxy</application> has application for both stand-alone
44 systems and multi-user networks.
47 You can find the latest version of the document at <ulink url="http://ijbswa.sourceforge.net/faq/">http://ijbswa.sourceforge.net/faq/</ulink>.
48 Please see the Contact section in the
49 <ulink url="http://ijbswa.sourceforge.net/user-manual/contact.html">user-manual</ulink> if you want to contact the developers.
53 <!-- Feel free to send a note to the developers at <email>ijbswa-developers@lists.sourceforge.net</email>. -->
59 <!-- ~~~~~ New section ~~~~~ -->
62 <sect1 id="introduction"><title>Introduction</title>
68 <!-- ~~~~~ New section ~~~~~ -->
70 <sect1 id="questions"><title>Frequently Asked Questions</title>
72 <!-- ~~~~~ New section ~~~~~ -->
74 <sect2 id="general"><title>General Information</title>
76 <sect3 id="newjb"><title>What is this new version of <application>Privoxy</application>?</title>
78 The original <application>Internet Junkbuster</application> (tm) is a
79 copyrighted product of <ulink url="http://www.junkbusters.com">Junkbusters
80 Corporation</ulink>. Development of this effort stopped some time ago as of
81 version 2.0.2. Stefan Waldherr started the ijbswa project on <ulink
82 url="http://ijbswa.sourceforge.net">Sourceforge</ulink> to rekindle
83 development. Other developers subsequently joined with Stefan, and have
84 since added many new features, refinements and enhancements.
87 The new <application>Privoxy</application> started with the same
88 <application>Junkbuster</application> code base, but has changed
89 significantly at this point.
96 <title id="whyprivoxy">Why <quote>Privoxy</quote>? Why a name change at all?</title>
98 <application>Privoxy</application> is for <quote>Privacy Enhancing Proxy</quote>.
99 There are possible legal complications from the continued use of the
100 <application>Junkbuster</application> name, which is a trademark of
101 <ulink url="http://junkbusters.com">Junkbusters Corporation</ulink>.
102 (There are no objections from Junkbusters Corporation to the
103 <application>Privoxy</application> project itself though, and they
104 in fact still share our ideals and goals.)
108 The developers also believed that there so many changes from the original
109 code, that it was time to make a clean break from the past and make
110 a name in their own right, especially now with the pending release of
117 <sect3 id="differs"><title>How does it differ from the old <application>Junkbuster?</application></title>
119 All the old features remain. The new <application>Privoxy</application>
120 still blocks ads and banners, still manages cookies, and still helps protect
121 your privacy. But, these are all enhanced, and many new features have been
122 added, all in the same vein.
125 The configuration has changed significantly as well. This is something that
126 users will notice right off the bat. The <quote>blocklist</quote> file does
127 not exist any more. This is replaced by <quote>actions</quote> files, such
128 as <filename>default.actions</filename>. This is where most of the per site
129 configuration is now.
134 <sect3 id="features"><title>What are some of the new features?</title>
136 This section is in both user-manual and faq. Please keep in sync!!!
143 Integrated browser based configuration and control utility (<ulink
144 url="http://p.p">http://p.p</ulink>). Browser-based tracing of rule
151 Modularized configuration that will allow for system wide settings, and
152 individual user settings. (not implemented yet, probably a 3.1 feature)
158 Blocking of annoying pop-up browser windows.
164 HTTP/1.1 compliant (most, but not all 1.1 features are supported).
170 Support for Perl Compatible Regular Expressions in the configuration files, and
171 generally a more sophisticated and flexible configuration syntax over
184 Web page content filtering (removes banners based on size,
185 invisible <quote>web-bugs</quote>, JavaScript, pop-ups, status bar abuse,
192 Bypass many click-tracking scripts (avoids script redirection).
199 Multi-threaded (POSIX and native threads).
205 Auto-detection and re-reading of config file changes.
211 User-customizable HTML templates (e.g. 404 error page).
217 Improved cookie management features (e.g. session based cookies).
223 Builds from source on most UNIX-like systems. Packages available for: Linux
224 (RedHat, SuSE, or Debian), Windows, Sun Solaris, Mac OSX, OS/2, HP-UX 11 and AmigaOS.
231 In addition, the configuration is much more powerful and versatile over-all.
240 <sect3 id="proxymoron"><title>What is a <quote>proxy</quote>? How does
241 <application>Privoxy</application> work? </title>
243 When you connect to a web site with <application>Privoxy</application>,
244 you are really connecting to your locally running version of
245 <application>Privoxy</application>. <application>Privoxy</application>
246 intercepts your requests for the web page, and relays that to the
247 <quote>real</quote> web site. The web site sends the HTTP data stream
248 back to <application>Privoxy</application>, where
249 <application>Privoxy</application> can work its magic before it
250 relays this data back to your web browser.
254 Since <application>Privoxy</application> sits between you and the
255 WWW, it is in a position to intercept and completely manage all web traffic and
256 HTTP content before it gets to your browser.
257 <application>Privoxy</application> uses various programming methods to do
258 this, all of which is under your control via the various configuration
263 There are many kinds of proxies. <application>Privoxy</application> best
264 fits the <quote>filtering proxy</quote> category.
269 <sect3 id="browsers2"><title>My browser does the same things as
270 <application>Privoxy</application>. Why should I use
271 <application>Privoxy</application> at all?</title>
273 Modern browsers do indeed have <emphasis>some</emphasis> of the same
274 functionality as <application>Privoxy</application>. Maybe this is
275 adequate for you. But <application>Privoxy</application> is much more
276 versatile and powerful, and can do a number of things that browsers just can't.
279 In addition, a proxy is good choice if you use multiple browsers, or
280 have a LAN with multiple computers. This way all the configuration
281 is in one place, and you don't have to maintain a similar configuration
282 for possibly many browsers.
289 <sect3 id="license"><title>Is there is a license or fee? What about a
290 warranty? Registration?</title>
292 <application>Privoxy</application> is licensed under the
293 GNU General Public License (GPL). It is free to use, copy,
294 modify or distribute as you wish under the terms of this license.
296 url="http://www.gnu.org/copyleft/gpl.html">http://www.gnu.org/copyleft/gpl.html</ulink>
300 There is no warranty of any kind, expressed, implied or otherwise. That is
301 something that would cost real money ;-) There is no registration either.
302 <application>Privoxy</application> really is <emphasis>free</emphasis>
308 <sect3 id="jointeam"><title>I would like to help you, what do I do?</title>
310 <sect4 id="jointeam-money"><title>Money Money Money</title>
312 We, of course, welcome donations and use the money for domain registering,
313 regular world-wide get-togethers (hahaha). Anyway, we'll soon describe the
314 process how to donate money to the team.
318 <sect4 id="jointeam-work"><title>You want to work with us?</title>
320 Well, helping the team is always a good idea. We welcome new developers,
321 RPM gurus or documentation makers. Simply get an account on sourceforge.net
322 and mail your id to the developer mailing list. Then read the
323 section Quickstart in the developers manual.
326 Once we have added you to the team, you'll have write access to the CVS
327 repository, and together we'll find a suitable task for you.
336 <!-- ~~~~~ New section ~~~~~ -->
338 <sect2 id="installation"><title>Installation</title>
340 <sect3 id="whichbrowsers">
341 <title>Which browsers are supported by <application>Privoxy</application>?</title>
343 Any browser that can be configured to use a <quote>proxy</quote>, which
344 is probably almost all browsers. Direct browser support is not necessary
345 since <application>Privoxy</application> runs as a separate application and
346 just exchanges standard HTML data with your browser.
351 <title>Which operating systems are supported?</title>
353 Right now Win32, Mac OSX, OS/2, AmigaOS, Linux, and many
358 Source code is available, so porting to other operating systems,
359 is always a possibility.
364 <sect3 id="newinstall"><title>Can I install
365 <application>Privoxy</application> over <application>Junkbuster</application>?</title>
367 We recommend you uninstall <application>Junkbuster</application>
368 first to minimize conflicts and confusion. You may want to
369 save your old configuration files for future reference. The configuration
370 is substantially changed.
374 url="http://ijbswa.sourceforge.net/user-manual/">user-manual</ulink> for
375 platform specific installation instructions. [FIXME: This is meant for after
376 the name change for 3.0!]
382 <title id="firststep">I just installed <application>Privoxy</application>. Is there anything
383 special I have to do now?</title>
386 All browsers must be told to use <application>Privoxy</application>
387 as a proxy by specifying the correct proxy address and port number
388 in the appropriate configuration area for the browser. See below.
395 <sect3 id="localhost"><title>What is the proxy address of <application>Privoxy</application>?</title>
397 If you set up the <application>Privoxy</application> to run on
398 the computer you browse from (rather than your ISP's server or some
399 networked computer on a LAN), the proxy will be on <quote>localhost</quote>
400 (which is the special name used by every computer on the Internet to refer
401 to itself) and the port will be 8118 (unless you have <application>Privoxy</application> to run on a different port with the
402 <emphasis>listen-address</emphasis> config option).
405 When configuring your browser's proxy settings you typically enter
406 the word <quote>localhost</quote> in the boxes next to <quote>HTTP</quote>
407 and <quote>Secure</quote> (HTTPS) and then the number <quote>8118</quote>
408 for <quote>port</quote>. This tells your browser to send all web
409 requests to <application>Privoxy</application> instead of directly to the
413 <application>Privoxy</application> can also be used to proxy for
414 a Local Area Network. In this case, your would enter either the IP
415 address of the LAN host where <application>Privoxy</application>
416 is running, or the equivalent hostname. Port assignment would be
420 <application>Privoxy</application> does not currently handle
421 protocols such as FTP, SMTP, IM, IRC, ICQ, or other Internet
427 <title id="nothing">I just installed <application>Privoxy</application>, and nothing is happening.
428 All the ads are there. What's wrong?</title>
431 Did you configure your browser to use <application>Privoxy</application>
432 as a proxy? It does not sound like it. See above. You might also try flushing
433 the browser's caches to force a full re-reading of pages. You can verify
434 that <application>Privoxy</application> is running, and your browser
435 is correctly configured by entering the special URL:
436 <ulink url="http://p.p/">http://p.p/</ulink>. This should give you
437 a banner that says <quote>This is Privoxy</quote> and
438 access to <application>Privoxy's</application> internal configuration.
439 If you see this, then you are good to go. If not, the browser or
440 <application>Privoxy</application> are not set up correctly.
449 <!-- ~~~~~ New section ~~~~~ -->
451 <sect2 id="configuration"><title>Configuration</title>
453 <sect3 id="newconfig"><title>Can I use my old config files?</title>
455 There are major changes to <application>Junkbuster</application>
456 configuration from version 2.0.x to 2.9.x and later. The older files will
457 not work at all. If this is the case, you will need to re-enter your old
458 data into the new configuration structure. This is probably also a good
459 recommendation even if upgrading from 2.9.x to 3.x since there were
460 many minor changes along the way.
465 <title id="actionsfile">What is an <quote>actions</quote> file?</title>
468 <quote>actions</quote> files are where various actions that
469 <application>Privoxy</application> might take, are configured.
470 Typically, you would define a set of default actions that apply
471 to all URLs, then add exceptions to these defaults.
475 Actions can be defined on a per site basis, or for groups of sites. Actions
476 can also be grouped together and then applied to one or more sites. There
477 are many possible actions that might apply to any given site. As an example,
478 if we are blocking cookies as one of our default
479 <application>actions</application>, but need to accept cookies from a given
480 site, we would define this in our <quote>actions</quote> file.
485 <application>Privoxy</application> comes with several default
486 <application>actions</application> files, with varying degrees
487 of filtering and blocking, as starting points for your own
488 configuration (see below).
493 <sect3 id="actionss">
494 <title>The <quote>actions</quote>concept confuses me. Please list
495 some of these <quote>actions</quote>.</title>
497 These are all explained in the
498 <ulink url="../user-manual/configuration.html#ACTIONSFILE">user-manual</ulink>.
499 Please refer to that.
505 <title id="actconfig">How are actions files configured? What is the easiest
506 way to do this?</title>
509 The easiest way to do this, is to access <application>Privoxy</application>
510 with your web browser at <ulink url="http://p.p/">http://p.p/</ulink>,
512 "<ulink url="http://ijbswa.sourceforge.net/config/edit-actions">Edit the actions list</ulink>"
513 from the selection list. You can also do this by editing the appropriate
514 file with a text editor.
520 url="../user-manual/configuration.html#ACTIONSFILE">user-manual</ulink> for a
521 detailed explanation of these and other configuration files, and their
522 various options and syntax.
528 FIXME: Commenting these out until we have some data there. HB 03/17/02.
530 <sect3 id="yahoo"><title>How can I make my Yahoo account work?</title>
536 <sect3 id="hotmail"> <title>How can I make my Hotmail account work?</title>
542 <sect3 id="gmx"> <title>How can I make my GMX account work?</title>
549 <sect3 id="configfiles"> <title>What are the differences between
550 intermediate.action, basic.action, etc.?</title>
552 Configuring <application>Privoxy</application> is not easy. To help you get
553 started, we provide you with three different default configurations. The
554 following table shows you, which features are enabled in each configuration.
557 <table frame=all><title>Default Configurations</title>
558 <tgroup cols=5 align=left colsep=1 rowsep=1>
566 <entry>Feature</entry>
567 <entry>default.action</entry>
568 <entry>basic.action</entry>
569 <entry>intermediate.action</entry>
570 <entry>advanced.action</entry>
576 <!-- <entry>f1</entry> -->
577 <!-- <entry>f2</entry> -->
578 <!-- <entry>f3</entry> -->
579 <!-- <entry>f4</entry> -->
580 <!-- <entry>f5</entry> -->
587 <entry>ad-filtering</entry>
595 <entry>blank image</entry>
603 <entry>de-animate GIFs</entry>
611 <entry>referer forging</entry>
619 <entry>jon's +no-cookies-keep (i.e. session cookies only)</entry>
627 <entry>no-popup windows</entry>
635 <entry>fast redirects</entry>
643 <entry>hide-referrer</entry>
651 <entry>hide-useragent</entry>
659 <entry>content-modification</entry>
667 <entry>feature-x</entry>
675 <entry>feature-y</entry>
683 <entry>feature-z</entry>
696 <sect3 id="browseconfig"> <title>Why can I change the configuration with a
697 browser? Does that not raise security issues?</title>
699 What I don't understand, is how I can browser edit the config file as a
700 regular user, while the whole /etc/privoxy hierarchy belongs to the user
701 "privoxy", with only 644 perms.
704 When you use the browser-based editor, <application>Privoxy</application>
705 itself is writing to the config files. Because
706 <application>Privoxy</application> is running as the user "privoxy", it can
707 update the config files.
710 If you don't like this, setting "enable-edit-actions 0" in the config file
711 will disable the browser-based editor. If you're that paranoid, you should
712 also consider setting "enable-remote-toggle 0" to prevent browser-based
713 enabling/disabling of <application>Privoxy</application>.
716 Note that normally only local users can connect to <application>Privoxy</application>, so this is not
717 (normally) a security problem.
723 <title id="filterfile">What is a <quote>default.filter</quote>?</title>
725 The <quote>default.filter</quote> file is used to <quote>filter</quote> any
726 web page content. By <quote>filtering</quote> we mean it can modify, remove,
727 or change <emphasis>anything</emphasis> on the page, including HTML tags, and
728 JavaScript. Regular expressions are used to accomplish this, and operate
729 on a line by line basis. This is potentially a very powerful feature, but
730 requires some expertise.
734 If you are familiar with regular expressions, and HTML, you can look at
735 the provided <filename>default.filter</filename> with a text editor and see
736 some of things it can be used for.
740 Presently, there is no GUI editor option for this part of the configuration,
741 but you can disable/enable various sections of the included default
742 file with the <quote>Actions List Editor</quote> from your browser.
748 <title id="lanconfig">How can I set up <application>Privoxy</application> to act as a proxy for my
751 By default, <application>Privoxy</application> only responds to requests
752 from localhost. To have it act as a server for a network, this needs to be
753 changed in the main config file where the <application>Privoxy</application>
754 configuration is located. In that file is a <quote>listen-address</quote>
755 option. It may be commented out with a <quote>#</quote> symbol. Make sure
756 it is uncommented, and assign it the address of the LAN gateway interface,
757 and port number to use:
762 listen-address 192.168.1.1:8118
767 Save the file, and restart <application>Privoxy</application>. Configure
768 all browsers on the network then to use this address and port number.
775 <title id="noseeum">Instead of ads, now I get a checkerboard pattern. I don't want to see anything.</title>
777 This is a configuration option for images that
778 <application>Privoxy</application> is stopping. You have the choice <!-- of
779 the --> <!-- <application>Privoxy</application> logo, --> a checkerboard
780 pattern, a transparent 1x1 GIF image (aka <quote>blank</quote>), or a custom
785 If you want to see nothing, then change the <quote>+image-blocker</quote>
786 action to <quote>+image-blocker{blank}</quote>. This can be done from the
787 <quote>Edit Actions List</quote> selection at <ulink
788 url="http://p.p/">http://p.p/</ulink>. Or by hand editing the appropriate
789 actions file. This will only effect what is defined as <quote>images</quote>
798 <title id="whyseeum">Why would anybody want to see a checkerboard pattern?</title>
800 This can be helpful for troubleshooting problems. It might also be good
801 for anyone new to <application>Privoxy</application> so that they can
802 see if their favorite pages are displaying correctly, and
803 <application>Privoxy</application> is not inadvertently removing something
810 <title id="blockedisugly">I see large red banners on some pages that say
811 <quote>Blocked</quote>. How do I get rid of this?</title>
813 These are URLs that match something in one of
814 <application>Privoxy's</application> block actions (+block). It is meant
815 to be a warning so that you know something has been blocked and an easy way
816 for you to see why. These are handled differently than what has been defined
817 as <quote>images</quote> (e.g. ad banners). If you want them to be treated
818 as if they were images, so that they can be made invisible, then move the
819 offending URL from the <quote>+block</quote> section to the
820 <quote>+imageblock</quote> section of your actions file. Alternately, you
821 could modify the <quote><filename>block</filename></quote> HTML template that
822 is used by <application>Privoxy</application> to display this, and make it
823 something more to your liking.
828 <sect3 id="otherproxy">
829 <title>How can I make <application>Privoxy</application> work with other
830 proxies like <application>Squid</application>?</title>
832 This can be done. See the <ulink
833 url="../user-manual/configuration.html#FORWARDING">user manual</ulink>,
834 which describes how to do this.
842 <!-- ~~~~~ New section ~~~~~ -->
844 <sect2 id="misc"><title>Miscellaneous</title>
847 <title id="slowsme">How much does <application>Privoxy</application> slow my browsing down? This
848 has to add extra time to browsing.</title>
850 It should not slow you down any in real terms, and may actually help
851 speed things up since ads, banners and other junk are not being displayed.
852 The actual processing time required by <application>Privoxy</application>
853 itself for each page, is relatively small in the overall scheme of things,
854 and happens very quickly. This is typically more than offset by time saved
855 not downloading and rendering ad images.
859 <quote>Filtering</quote> via the <filename>filterfile</filename>
860 mechanism may cause a perceived slowdown, since the entire page is buffered
861 before displaying. See below.
868 <sect3 id="loadingtimes"><title>I noticed considerable
869 delays in page requests compared to the old Junkbuster. What's wrong?</title>
871 Using the default filtering configuration, I noticed considerable delays in
872 page requests compared to the old Junkbuster. Loading pages with large contents
873 seemed to take forever, then suddenly delivering all the content at once.
876 The whole content must be loaded in order to filter, and nothing is is
877 sent to the browser during this time. The loading time does not really
878 change in real numbers, but the feeling is different, because most
879 browsers are able to start rendering incomplete content, giving the
880 user a feeling of "it works".
883 To modify the content of a page (i.e. make frames resizeable again, etc.) and
884 not just replace ads, <application>Privoxy</application> needs to download the
885 entire page first, do its content magic and then send the page to the browser.
890 <sect3 id="configurl"><title>What is the "http://p.p/"?</title>
892 Since <application>Privoxy</application> sits between your web browser and the Internet, it can be
893 programmed to handle certain pages specially.
897 With recent versions of <application>Privoxy</application> (version 2.9.x), you can get some
898 information about <application>Privoxy</application> and change some settings by going to
899 http://p.p/ or, equivalently, http://ijbswa.sourceforge.net/config/
900 (Note that p.p is far easier to type but may not work in some
905 These pages are *not* forwarded to a server on the Internet - instead they are
906 handled by a special web server which is built in to <application>Privoxy</application>.
910 If you are not running <application>Privoxy</application>, then http://p.p/ will fail, and
911 http://ijbswa.sourceforge.net/config/ will return a web page telling you
912 you're not running <application>Privoxy</application>.
916 If you have version 2.0.2, then the equivalent is
917 http://example.com/show-proxy-args (but you get far less information, and you
918 should really consider upgrading to 2.9.x).
923 FIXME: commented out until we have data. HB 03/18/02.
925 <sect3 id="badfiledesc"><title>I get the message 'Bad File Descriptor', why?</title>
931 <sect3 id="proxy-chaining"><title>How do I chain <application>Privoxy</application> with other proxies
932 (e.g. squid)?</title>
939 <sect3 id="blocklist"><title>Do you still maintain the blocklists?</title>
941 No. The format of the blocklists has changed significantly in the versions
942 2.9.x. Once we have released the new version, there will again be
943 blocklists that you can update automatically.
947 <sect3 id="newads"><title>How can I submit new ads?</title>
949 As of now, please discontinue to submit new ad blocking infos. Once we
950 have released the new version, there will again be a form on the website,
951 which you can use to contribute new ads.
955 <sect3 id="ip"><title>How can I hide my IP address?</title>
957 You cannot hide your IP address with <application>Privoxy</application> or any other software, since
958 the server needs to know your IP address to send the answer to you.
961 Fortunately there are many publicly usable anonymous proxies out there, which
962 solve the problem by providing a further level of indirection between you and
963 the web server, shared by many people and thus letting your requests "drown"
964 in white noise of unrelated requests as far as user tracking is concerned.
967 Most of them will, however, log your IP address and make it available to the
968 authorities in case you abuse that anonymity for criminal purposes. In fact
969 you can't even rule out that some of them only exist to *collect* information
970 on (those suspicious) people with a more than average preference for privacy.
973 You can find a list of anonymous public proxies at <ulink
974 url="http://www.multiproxy.org/anon_list.htm">multiproxy.org</ulink> and many
979 <!-- <sect3 id="image"><title>What is the imagefile (simage.ini, etc.) for?</title> -->
981 <!-- Anytime <application>Privoxy</application> determines (with the help of the blocklist) that a URL -->
982 <!-- contains an advertisement, it has to decide whether this advertisement is an -->
983 <!-- image or not. <application>Privoxy</application> uses the imagefile for that purpose. -->
988 <title id="anonforsure">Can <application>Privoxy</application> guarantee I am anonymous?</title>
990 No. Your chances of remaining anonymous are greatly improved, but unless you
991 are an expert on Internet security it would be safest to assume that
992 everything you do on the Web can be traced back to you.
995 <application>Privoxy</application> can remove various information about you,
996 and allows <emphasis>you</emphasis> more freedom to decide which sites
997 you can trust. But it's still possible that web sites can find out who you
998 are. Here's one way this can happen.
1001 A few browsers disclose the user's email address in certain situations, such
1002 as when transferring a file by FTP. <application>Privoxy</application>
1003 does not filter FTP. If you need this feature, or are concerned about the
1004 mail handler of your browser disclosing your email address, you might
1005 consider products such as <application>NSClean</application>.
1008 Browsers available only as binaries could use non-standard headers to give
1009 out any information they can have access to: see the manufacturer's license
1010 agreement. It's impossible to anticipate and prevent every breach of privacy
1011 that might occur. The professionally paranoid prefer browsers available as
1012 source code, because anticipating their behavior is easier. Trust the source,
1019 <title id="sitebreak">Might some things break because header information is
1020 being altered?</title>
1023 Definitely. More and more sites use HTTP header content to decide what to
1024 display and how to display it. There is many ways that this can be handled,
1025 so having hard and fast rules, is tricky.
1029 <quote>USER AGENT</quote> in particular is often used in this way to identify
1030 the browser, and adjust content accordingly. Changing this now is not
1031 recommended, since so many sites do look for this. You may get undesirable
1032 results by changing this.
1036 For instance, different browsers use different encodings of Russian and Czech
1037 characters, certain web servers convert pages on-the-fly according to the
1038 User Agent header. Giving a <quote>User Agent</quote> with the wrong
1039 operating system or browser manufacturer causes some sites in these languages
1040 to be garbled; Surfers to Eastern European sites should change it to
1041 something closer. And then some page access counters work by looking at the
1042 <quote>REFERER</quote> header; they may fail or break if unavailable. The
1043 weather maps of Intellicast have been blocked by their server when no
1044 <quote>REFERER</quote> or cookie is provided, is another example. There are
1045 many, many other ways things can go wrong when trying to fool a web server.
1049 If you have problems with a site, you will have to adjust your configuration
1050 accordingly. Cookies are probably the most likely adjustment that may
1051 be required, but by no means the only one.
1059 <title id="caching">Can <application>Privoxy</application> act as a <quote>caching</quote> proxy to
1060 speed up web browsing?</title>
1062 No, it does not have this ability at all. You want something like
1063 <ulink url="http://www.squid-cache.org/">Squid</ulink> for this. And, yes,
1064 before you ask, <application>Privoxy</application> can co-exist
1065 with other kinds of proxies like <quote>Squid</quote>.
1070 <title id="firewall">What about as a firewall? Can <application>Privoxy</application> protect me?</title>
1072 Not in the way you mean, or in the way a true firewall can, or a proxy that
1073 has this specific capability. <application>Privoxy</application> can help
1074 protect your privacy, but not really protect you from intrusion attempts.
1080 <title id="logo">The <application>Privoxy</application> logo that replaces ads is very blocky
1081 and ugly looking. Can't a better font be used?</title>
1084 This is not a font problem. The logo is an image that is created by
1085 <application>Privoxy</application> on the fly. So as to not waste
1086 memory, the image is rather small. The blockiness comes when the
1087 image is scaled to fill a largish area. There is not much to be done
1088 about this, other than to use one of the other
1089 <quote>imageblock</quote> directives: <emphasis>pattern</emphasis>,
1090 <emphasis>blank</emphasis>, or a URL of your choosing.
1093 Given the above problem, we have decided to remove the logo option entirely
1100 <title id="wasted">I have large empty spaces now where ads used to be.
1101 Why does <application>Privoxy</application> leave these large gaps?</title>
1103 It would be easy enough to just eliminate this space altogether, rather than
1104 fill it with blank space. But, this would create problems with many pages
1105 that use the overall size of the ad to help organize the page layout and
1106 position the various components of the page where they were intended to be.
1107 It is best left this way.
1113 <title id="ssl">How can <application>Privoxy</application> filter Secure (HTTPS) URLs?</title>
1115 This is a limitation since HTTPS transactions are encrypted SSL sessions
1116 between your browser and the secure site, and are meant to be reliably
1117 <emphasis>secure</emphasis> and private. This means that all cookies and HTTP
1118 header information are also encrypted from the time they leave your browser,
1119 to the site, and vice versa. <application>Privoxy</application> does not
1120 try to unencrypt this information, so it just passes through as is.
1121 <application>Privoxy</application> can still catch images and ads that
1122 are embedded in the SSL stream though.
1129 <title id="secure"><application>Privoxy</application> runs as a <quote>server</quote>. How
1130 secure is it? Do I need to take any special precautions?</title>
1132 There are no known exploits that might effect
1133 <application>Privoxy</application>. On Unix-like systems,
1134 <application>Privoxy</application> can run as a non-privileged
1135 user, which is how we recommend it be run. Also, by default
1136 <application>Privoxy</application> only listens to requests
1137 from <quote>localhost</quote>. It is not itself directly exposed to the
1138 Internet in this configuration. If you want to have
1139 <application>Privoxy</application> serve as a LAN proxy, this will have to
1140 be opened up to allow for LAN requests. In this case, we'd recommend
1141 you specify only the LAN gateway address, e.g. 192.168.1.1 in the main
1142 <application>Privoxy</application> config file. All LAN hosts can then use
1143 this as their proxy address in the browser proxy configuration. In this way,
1144 <application>Privoxy</application> will not listen on any external ports.
1145 Of course, a firewall is always good too. Better safe than sorry.
1150 <sect3 id="turnoff">
1151 <title>How can I temporarily disable <application>Privoxy</application>?</title>
1153 The easiest way is to access <application>Privoxy</application> with your
1154 browser by using the special URL: <ulink url="http://p.p/">http://p.p/</ulink>
1155 and select "Toggle Privoxy on or off" from that page.
1163 <!-- ~~~~~ New section ~~~~~ -->
1166 <title id="trouble">Troubleshooting</title>
1169 <title id="refused">I just upgraded and am getting <quote>connection refused</quote>
1170 with every web page?</title>
1172 Either <application>Privoxy</application> is not running, or your
1173 browser is configured for a different port than what
1174 <application>Privoxy</application> is using.
1178 The old <application>Privoxy</application> (and also
1179 <application>Junkbuster</application>) used port 8000 by
1180 default. This has been changed to port 8118 now, due to a conflict
1181 with NAS (Network Audio Service), which uses port 8000. If you haven't,
1182 you need to change your browser to the new port number, or alternately
1183 change <application>Privoxy's</application> <quote>listen-address</quote>
1184 setting in the <filename>config</filename> file used to start
1185 <application>Privoxy</application>.
1191 <title id="flushit">I just added a new rule, but the steenkin ad is
1192 still getting through. How?</title>
1194 If the ad had been displayed before you added its URL, it will probably be
1195 held in the browser's cache for some time, so it will be displayed without
1196 the need for any request to the server, and <application>Privoxy</application>
1197 will not be in the picture. The best thing to do is try flushing the browser's
1198 caches. And then try again.
1202 If this doesn't help, you probably have an error in the rule you
1203 applied. Try pasting the full URL of the offending ad into <ulink
1204 url="http://ijbswa.sourceforge.net/config/show-url-info">http://ijbswa.sourceforge.net/config/show-url-info</ulink>
1205 and see if any actions match your new rule.
1211 <title id="badsite">One of my favorite sites does not work with <application>Privoxy</application>.
1212 What can I do?</title>
1215 First verify that it is indeed a <application>Privoxy</application> problem,
1216 by disabling <application>Privoxy</application> filtering and blocking.
1217 Go to <ulink url="http://p.p/">http://p.p/</ulink> and click on
1218 <quote>Toggle Privoxy On or Off</quote>, then disable it. Now try that
1223 If still a problem, go to <quote>Show which actions apply to a URL and
1224 why</quote> from <ulink url="http://p.p/">http://p.p/</ulink> and paste
1225 the full URL of the page in question into the prompt. See which actions are
1226 being applied to the URL. Now, armed with this information, go to <quote>Edit
1227 the actions list</quote>. Here you should see various sections that have
1228 various <application>Privoxy</application> features disabled for specific
1229 sites. Disabled <quote>actions</quote> will have a <quote>-</quote> (minus
1230 sign) in front of them. Add your problem page URL to one of these sections
1231 that looks like it is disabling the feature that is causing the
1232 problem. Re-try the page. There might be some trial and error involved. This
1233 is discussed in a little more detail in the <ulink
1234 url="../user-manual/appendix.html#ACTIONSANAT">user-manual
1240 Alternately, if you are comfortable with a text editor, you can accomplish
1241 the same thing by editing the appropriate <quote>actions</quote> file.
1247 <title id="time">What time is it?</title>
1258 <!-- ~~~~~ New section ~~~~~ -->
1260 FIXME: Commented out until we have something to put here. HB 03/18/02.
1261 <sect1 id="knownissues"><title>Known Issues</title>
1268 <!-- ~~~~~ New section ~~~~~ -->
1271 This is referenced in the doc header already. HB 03/25/02
1273 <sect1 id="contact"><title>Contact the developers</title>
1274 <para>Please see the user manual for information on how to contact the developers.
1278 <!-- ~~~~~ New section ~~~~~ -->
1279 <sect1 id="copyright"><title>Copyright and History</title>
1280 <para>Please see the user manual for information on Copyright and History.
1284 <!-- ~~~~~ New section ~~~~~ -->
1285 <sect1 id="seealso"><title>See also</title>
1286 <para>Please see the user manual for information on references.
1292 Tue 09/11/01 06:38:14 PM EST: Test SGML doc by Hal Burgiss.
1294 Last modified: Mon Sep 10 19:22:09 CEST 2001
1296 This program is free software; you can redistribute it
1297 and/or modify it under the terms of the GNU General
1298 Public License as published by the Free Software
1299 Foundation; either version 2 of the License, or (at
1300 your option) any later version.
1302 This program is distributed in the hope that it will
1303 be useful, but WITHOUT ANY WARRANTY; without even the
1304 implied warranty of MERCHANTABILITY or FITNESS FOR A
1305 PARTICULAR PURPOSE. See the GNU General Public
1306 License for more details.
1308 The GNU General Public License should be included with
1309 this file. If not, you can view it at
1310 http://www.gnu.org/copyleft/gpl.html
1311 or write to the Free Software Foundation, Inc., 59
1312 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
1315 Revision 1.29 2002/03/25 05:23:57 hal9
1316 Moved section, and touch ups.
1318 Revision 1.28 2002/03/25 04:27:33 hal9
1319 New section related to name change.
1321 Revision 1.25 2002/03/24 16:08:08 swa
1322 we are too lazy to make a block-built
1323 privoxy logo. hence removed the option.
1325 Revision 1.24 2002/03/24 15:46:20 swa
1326 name change related issue.
1328 Revision 1.23 2002/03/24 12:33:01 swa
1331 Revision 1.22 2002/03/24 11:51:00 swa
1332 name change. changed filenames.
1334 Revision 1.21 2002/03/24 11:01:06 swa
1337 Revision 1.20 2002/03/23 15:13:11 swa
1338 renamed every reference to the old name with foobar.
1339 fixed "application foobar application" tag, fixed
1340 "the foobar" with "foobar". left junkbustser in cvs
1341 comments and remarks to history untouched.
1343 Revision 1.19 2002/03/21 17:01:54 hal9
1346 Revision 1.18 2002/03/18 16:40:31 hal9
1349 Revision 1.17 2002/03/18 03:53:53 hal9
1352 Revision 1.16 2002/03/17 21:32:56 hal9
1353 A few more additions.
1355 Revision 1.15 2002/03/17 07:25:59 hal9
1356 Correcting some of my typos, and some additions.
1358 Revision 1.14 2002/03/17 02:39:13 hal9
1359 A little more added ...
1361 Revision 1.13 2002/03/17 00:22:20 hal9
1362 Adding new stuff, and trying to incorporate stuff from old faq.
1364 Revision 1.12 2002/03/11 20:13:21 swa
1367 Revision 1.11 2002/03/11 18:42:27 swa
1370 Revision 1.10 2002/03/11 13:13:27 swa
1371 correct feedback channels
1373 Revision 1.9 2002/03/10 23:34:04 swa
1374 more info on not hiding ip address
1376 Revision 1.8 2002/03/09 15:55:48 swa
1377 added default config section
1379 Revision 1.7 2002/03/07 18:16:55 swa
1382 Revision 1.6 2002/03/07 13:16:31 oes
1383 Committing changes by Stefan
1385 Revision 1.5 2002/03/02 15:50:04 swa
1386 2.9.11 version. more input for docs.
1388 Revision 1.4 2002/02/24 14:34:24 jongfoster
1389 Formatting changes. Now changing the doctype to DocBook XML 4.1
1390 will work - no other changes are needed.
1392 Revision 1.3 2001/09/23 10:13:48 swa
1393 upload process established. run make webserver and
1394 the documentation is moved to the webserver. documents
1395 are now linked correctly.
1397 Revision 1.2 2001/09/13 15:20:17 swa
1398 merged standards into developer manual
1400 Revision 1.1 2001/09/12 15:36:41 swa
1401 source files for junkbuster documentation
1403 Revision 1.3 2001/09/10 17:43:59 swa
1404 first proposal of a structure.
1406 Revision 1.2 2001/06/13 14:28:31 swa
1407 docs should have an author.
1409 Revision 1.1 2001/06/13 14:20:37 swa
1410 first import of project's documentation for the webserver.