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9 $Id: faq.sgml,v 1.33 2002/03/29 01:31:48 hal9 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 1.33 2002/03/29 01:31:48 hal9 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://sourceforge.net/projects/ijbswa/">Sourceforge</ulink> to rekindle
94 development. Other developers subsequently joined with Stefan, and have
95 since added many new features, refinements and enhancements. The result
96 of this effort is <application>Privoxy</application>.
99 <application>Privoxy</application> started with the same
100 <application>Junkbuster 2.0.2</application> code base, but has advanced
101 significantly at this point.
108 <title id="whyprivoxy">Why <quote>Privoxy</quote>? Why a name change at all?</title>
110 <application>Privoxy</application> is the
111 <quote><emphasis>Privacy Enhancing Proxy</emphasis></quote>.
114 There are possible legal complications from the continued use of the
115 <application>Junkbuster</application> name, which is a trademark of
116 <ulink url="http://junkbusters.com">Junkbusters Corporation</ulink>.
117 (There are, however, no objections from Junkbusters Corporation to the
118 <application>Privoxy</application> project itself, and they, in fact, still
119 share our ideals and goals.)
123 The developers also believed that there so many changes from the original
124 code, that it was time to make a clean break from the past and make
125 a name in their own right, especially now with the pending release of
132 <sect3 id="differs"><title>How does <application>Privoxy</application> differ
133 from the old <application>Junkbuster?</application></title>
135 <application>Privoxy</application> picks up where
136 <application>Junkbuster</application> left off. All the old features remain.
137 The new <application>Privoxy</application> still blocks ads and banners,
138 still manages cookies, and still helps protect your privacy. But, these are
139 all enhanced, and many new features have been added, all in the same vein.
142 The configuration has changed significantly as well. This is something that
143 users will notice right off the bat. The <quote>blocklist</quote> file does
144 not exist any more. This is replaced by <quote>actions</quote> files, such
145 as <filename>default.actions</filename>. This is where most of the per site
146 configuration is now.
151 <sect3 id="features"><title>What are some of the new features?</title>
153 This section is in both user-manual and faq. Please keep in sync!!!
160 Integrated browser based configuration and control utility (<ulink
161 url="http://p.p">http://p.p</ulink>). Browser-based tracing of rule
168 Modularized configuration that will allow for system wide settings, and
169 individual user settings. (not implemented yet, probably a 3.1 feature)
175 Blocking of annoying pop-up browser windows.
181 HTTP/1.1 compliant (most, but not all 1.1 features are supported).
187 Support for Perl Compatible Regular Expressions in the configuration files, and
188 generally a more sophisticated and flexible configuration syntax over
201 Web page content filtering (removes banners based on size,
202 invisible <quote>web-bugs</quote>, JavaScript, pop-ups, status bar abuse,
209 Bypass many click-tracking scripts (avoids script redirection).
216 Multi-threaded (POSIX and native threads).
222 Auto-detection and re-reading of config file changes.
228 User-customizable HTML templates (e.g. 404 error page).
234 Improved cookie management features (e.g. session based cookies).
240 Improved signal handling, and a true daemon mode (Unix).
246 Builds from source on most UNIX-like systems. Packages available for: Linux
247 (RedHat, SuSE, or Debian), Windows, Sun Solaris, Mac OSX, OS/2, HP-UX 11 and AmigaOS.
254 In addition, the configuration is much more powerful and versatile over-all.
263 <sect3 id="proxymoron"><title>What is a <quote>proxy</quote>? How does
264 <application>Privoxy</application> work? </title>
266 When you connect to a web site with <application>Privoxy</application>,
267 you are really connecting to your locally running version of
268 <application>Privoxy</application>. <application>Privoxy</application>
269 intercepts your requests for the web page, and relays that to the
270 <quote>real</quote> web site. The web site sends the HTTP data stream
271 back to <application>Privoxy</application>, where
272 <application>Privoxy</application> can work its magic before it
273 relays this data back to your web browser.
277 Since <application>Privoxy</application> sits between you and the
278 WWW, it is in a position to intercept and completely manage all web traffic and
279 HTTP content before it gets to your browser.
280 <application>Privoxy</application> uses various programming methods to do
281 this, all of which is under your control via the various configuration
286 There are many kinds of proxies. <application>Privoxy</application> best
287 fits the <quote>filtering proxy</quote> category.
294 <title id="knows">How does <application>Privoxy</application> know what is
295 an ad, and what is not?</title>
297 <application>Privoxy</application> processes all the raw content of every
298 web page. So it reads everything on each page. It then compares this to the
299 rules as set up in the configuration files, and looks for any matches to
300 these rules. <application>Privoxy</application> makes heavy use of
301 <quote>regular expressions</quote>. (If you are not familiar with regular
302 expressions, it is explained briefly in <ulink
303 url="../user-manual/appendix.html">the user manual</ulink>.) Regular
304 expressions facilitate matching of one text string against another, using
305 wildcards to build complex patterns. So <application>Privoxy</application>
306 will typically look for URLs and other content that match certain key words
307 and expressions as defined in the configuration files. For instance a URL
308 that contains <quote>/banners</quote>, has a high probability of containing
309 ad banners, and thus would be a prime candidate to have a matching rule.
312 So <application>Privoxy</application> will look for these kinds of obvious
313 looking culprits. And also, will use lists of known organizations that
314 specialize in ads. Again, using complex patterns to match as many potential
315 combinations as possible since there tend to be many, many variations used by
316 advertisers, and new ones are being introduced all the time.
321 <title id="mistakes">Can <application>Privoxy</application> make mistakes?
322 This does not sound very scientific.</title>
324 Actually, it's a black art ;-) And yes, it is always possible to have a broad rule
325 accidentally block something by mistake. There is a good chance you may run
326 into such a situation at some point. It is tricky writing rules to cover
327 every conceivable possibility, and not occasionally get false positives.
331 But this should not be a big concern since the
332 <application>Privoxy</application> configuration is very flexible, and
333 includes tools to help identify these types of situations so they can be
334 addressed as needed, allowing you to customize your installation.
335 (<link linkend="badsite">See the appendix below</link>.)
341 <sect3 id="browsers2"><title>My browser does the same things as
342 <application>Privoxy</application>. Why should I use
343 <application>Privoxy</application> at all?</title>
345 Modern browsers do indeed have <emphasis>some</emphasis> of the same
346 functionality as <application>Privoxy</application>. Maybe this is
347 adequate for you. But <application>Privoxy</application> is much more
348 versatile and powerful, and can do a number of things that browsers just can't.
351 In addition, a proxy is good choice if you use multiple browsers, or
352 have a LAN with multiple computers. This way all the configuration
353 is in one place, and you don't have to maintain a similar configuration
354 for possibly many browsers.
361 <sect3 id="license"><title>Is there is a license or fee? What about a
362 warranty? Registration?</title>
364 <application>Privoxy</application> is licensed under the
365 GNU General Public License (GPL). It is free to use, copy,
366 modify or distribute as you wish under the terms of this license.
368 url="http://www.gnu.org/copyleft/gpl.html">http://www.gnu.org/copyleft/gpl.html</ulink>
372 There is no warranty of any kind, expressed, implied or otherwise. That is
373 something that would cost real money ;-) There is no registration either.
374 <application>Privoxy</application> really is <emphasis>free</emphasis>
380 <sect3 id="jointeam"><title>I would like to help you, what do I do?</title>
382 <sect4 id="jointeam-money"><title>Money Money Money</title>
384 We, of course, welcome donations and use the money for domain registering,
385 regular world-wide get-togethers (hahaha). Anyway, we'll soon describe the
386 process how to donate money to the team.
390 <sect4 id="jointeam-work"><title>You want to work with us?</title>
392 Well, helping the team is always a good idea. We welcome new developers,
393 RPM gurus or documentation makers. Simply get an account on sourceforge.net
394 and mail your id to the developer mailing list. Then read the
395 section Quickstart in the <ulink url="http://privoxy.org/developer-manual/quickstart.html">
396 Developer's Manual</ulink>.
399 Once we have added you to the team, you'll have write access to the CVS
400 repository, and together we'll find a suitable task for you.
409 <!-- ~~~~~ New section ~~~~~ -->
411 <sect2 id="installation"><title>Installation</title>
413 <sect3 id="whichbrowsers">
414 <title>Which browsers are supported by <application>Privoxy</application>?</title>
416 Any browser that can be configured to use a <quote>proxy</quote>, which
417 should be virtually all browsers. Direct browser support is not necessary
418 since <application>Privoxy</application> runs as a separate application and
419 just exchanges standard HTML data with your browser.
424 <title>Which operating systems are supported?</title>
426 Right now Win32, Mac OSX, OS/2, AmigaOS, Linux, and many
431 Source code is available, so porting to other operating systems,
432 is always a possibility.
437 <sect3 id="newinstall"><title>Can I install
438 <application>Privoxy</application> over <application>Junkbuster</application>?</title>
440 We recommend you uninstall <application>Junkbuster</application>
441 first to minimize conflicts and confusion. You may want to
442 save your old configuration files for future reference. The configuration
443 is substantially changed.
447 url="../user-manual/index.html">user-manual</ulink> for
448 platform specific installation instructions. [FIXME: This is meant for after
449 the name change for 3.0!]
452 Note: Some installers may automatically uninstall
453 <application>Junkbuster</application>, if present!
459 <title id="firststep">I just installed <application>Privoxy</application>. Is there anything
460 special I have to do now?</title>
463 All browsers must be told to use <application>Privoxy</application>
464 as a proxy by specifying the correct proxy address and port number
465 in the appropriate configuration area for the browser. See below.
466 Also, you should flush your browser's memory and disk cache to get rid of any
474 <sect3 id="localhost"><title>What is the proxy address of <application>Privoxy</application>?</title>
476 If you set up the <application>Privoxy</application> to run on
477 the computer you browse from (rather than your ISP's server or some
478 networked computer on a LAN), the proxy will be on <quote>localhost</quote>
479 (which is the special name used by every computer on the Internet to refer
480 to itself) and the port will be 8118 (unless you have <application>Privoxy</application> to run on a different port with the
481 <emphasis>listen-address</emphasis> config option).
484 When configuring your browser's proxy settings you typically enter
485 the word <quote>localhost</quote> in the boxes next to <quote>HTTP</quote>
486 and <quote>Secure</quote> (HTTPS) and then the number <quote>8118</quote>
487 for <quote>port</quote>. This tells your browser to send all web
488 requests to <application>Privoxy</application> instead of directly to the
492 <application>Privoxy</application> can also be used to proxy for
493 a Local Area Network. In this case, your would enter either the IP
494 address of the LAN host where <application>Privoxy</application>
495 is running, or the equivalent hostname. Port assignment would be
499 <application>Privoxy</application> does not currently handle
500 protocols such as FTP, SMTP, IM, IRC, ICQ, or other Internet
506 <title id="nothing">I just installed <application>Privoxy</application>, and nothing is happening.
507 All the ads are there. What's wrong?</title>
510 Did you configure your browser to use <application>Privoxy</application>
511 as a proxy? It does not sound like it. See above. You might also try flushing
512 the browser's caches to force a full re-reading of pages. You can verify
513 that <application>Privoxy</application> is running, and your browser
514 is correctly configured by entering the special URL:
515 <ulink url="http://p.p/">http://p.p/</ulink>. This should give you
516 a banner that says <quote>This is Privoxy</quote> and
517 access to <application>Privoxy's</application> internal configuration.
518 If you see this, then you are good to go. If not, the browser or
519 <application>Privoxy</application> are not set up correctly.
528 <!-- ~~~~~ New section ~~~~~ -->
530 <sect2 id="configuration"><title>Configuration</title>
532 <sect3 id="newconfig"><title>Can I use my old config files?</title>
534 There are major changes to <application>Junkbuster</application>
535 configuration from version 2.0.x to 2.9.x and later. The older files will
536 not work at all. If this is the case, you will need to re-enter your old
537 data into the new configuration structure. This is probably also a good
538 recommendation even if upgrading from 2.9.x to 3.x since there were
539 many minor changes along the way.
544 <title id="actionsfile">What is an <quote>actions</quote> file?</title>
547 <quote>actions</quote> files are where various actions that
548 <application>Privoxy</application> might take, are configured.
549 Typically, you would define a set of default actions that apply
550 to all URLs, then add exceptions to these defaults.
554 Actions can be defined on a per site basis, or for groups of sites. Actions
555 can also be grouped together and then applied to one or more sites. There
556 are many possible actions that might apply to any given site. As an example,
557 if we are blocking cookies as one of our default
558 <application>actions</application>, but need to accept cookies from a given
559 site, we would define this in our <quote>actions</quote> file.
564 <application>Privoxy</application> comes with several default
565 <application>actions</application> files, with varying degrees
566 of filtering and blocking, as starting points for your own
567 configuration (see below).
572 <sect3 id="actionss">
573 <title>The <quote>actions</quote>concept confuses me. Please list
574 some of these <quote>actions</quote>.</title>
576 These are all explained in the
577 <ulink url="../user-manual/configuration.html#ACTIONSFILE">user-manual</ulink>.
578 Please refer to that.
584 <title id="actconfig">How are actions files configured? What is the easiest
585 way to do this?</title>
588 The easiest way to do this, is to access <application>Privoxy</application>
589 with your web browser at <ulink url="http://p.p/">http://p.p/</ulink>,
591 "<ulink url="http://www.privoxy.org/config/edit-actions">Edit the actions list</ulink>"
592 from the selection list. You can also do this by editing the appropriate
593 file with a text editor.
599 url="../user-manual/configuration.html#ACTIONSFILE">user-manual</ulink> for a
600 detailed explanation of these and other configuration files, and their
601 various options and syntax.
607 FIXME: Commenting these out until we have some data there. HB 03/17/02.
609 <sect3 id="yahoo"><title>How can I make my Yahoo account work?</title>
615 <sect3 id="hotmail"> <title>How can I make my Hotmail account work?</title>
621 <sect3 id="gmx"> <title>How can I make my GMX account work?</title>
628 <sect3 id="configfiles"> <title>What are the differences between
629 intermediate.action, basic.action, etc.?</title>
631 Configuring <application>Privoxy</application> is not easy. To help you get
632 started, we provide you with three different default configurations. The
633 following table shows you, which features are enabled in each configuration.
636 <table frame=all><title>Default Configurations</title>
637 <tgroup cols=5 align=left colsep=1 rowsep=1>
645 <entry>Feature</entry>
646 <entry>default.action</entry>
647 <entry>basic.action</entry>
648 <entry>intermediate.action</entry>
649 <entry>advanced.action</entry>
655 <!-- <entry>f1</entry> -->
656 <!-- <entry>f2</entry> -->
657 <!-- <entry>f3</entry> -->
658 <!-- <entry>f4</entry> -->
659 <!-- <entry>f5</entry> -->
666 <entry>ad-filtering</entry>
674 <entry>blank image</entry>
682 <entry>de-animate GIFs</entry>
690 <entry>referer forging</entry>
698 <entry>jon's +no-cookies-keep (i.e. session cookies only)</entry>
706 <entry>no-popup windows</entry>
714 <entry>fast redirects</entry>
722 <entry>hide-referrer</entry>
730 <entry>hide-useragent</entry>
738 <entry>content-modification</entry>
746 <entry>feature-x</entry>
754 <entry>feature-y</entry>
762 <entry>feature-z</entry>
775 <sect3 id="browseconfig"> <title>Why can I change the configuration with a
776 browser? Does that not raise security issues?</title>
778 What I don't understand, is how I can browser edit the config file as a
779 regular user, while the whole /etc/privoxy hierarchy belongs to the user
780 "privoxy", with only 644 perms.
783 When you use the browser-based editor, <application>Privoxy</application>
784 itself is writing to the config files. Because
785 <application>Privoxy</application> is running as the user "privoxy", it can
786 update the config files.
789 If you don't like this, setting "enable-edit-actions 0" in the config file
790 will disable the browser-based editor. If you're that paranoid, you should
791 also consider setting "enable-remote-toggle 0" to prevent browser-based
792 enabling/disabling of <application>Privoxy</application>.
795 Note that normally only local users can connect to <application>Privoxy</application>, so this is not
796 (normally) a security problem.
802 <title id="filterfile">What is <quote>default.filter</quote>?</title>
804 The <quote>default.filter</quote> file is used to <quote>filter</quote> any
805 web page content. By <quote>filtering</quote> we mean it can modify, remove,
806 or change <emphasis>anything</emphasis> on the page, including HTML tags, and
807 JavaScript. Regular expressions are used to accomplish this, and operate
808 on a line by line basis. This is potentially a very powerful feature, but
809 requires some expertise.
813 If you are familiar with regular expressions, and HTML, you can look at
814 the provided <filename>default.filter</filename> with a text editor and see
815 some of things it can be used for.
819 Presently, there is no GUI editor option for this part of the configuration,
820 but you can disable/enable various sections of the included default
821 file with the <quote>Actions List Editor</quote> from your browser.
827 <title id="lanconfig">How can I set up <application>Privoxy</application> to act as a proxy for my
830 By default, <application>Privoxy</application> only responds to requests
831 from localhost. To have it act as a server for a network, this needs to be
832 changed in the main config file where the <application>Privoxy</application>
833 configuration is located. In that file is a <quote>listen-address</quote>
834 option. It may be commented out with a <quote>#</quote> symbol. Make sure
835 it is uncommented, and assign it the address of the LAN gateway interface,
836 and port number to use:
841 listen-address 192.168.1.1:8118
846 Save the file, and restart <application>Privoxy</application>. Configure
847 all browsers on the network then to use this address and port number.
854 <title id="noseeum">Instead of ads, now I get a checkerboard pattern. I don't want to see anything.</title>
856 This is a configuration option for images that
857 <application>Privoxy</application> is stopping. You have the choice <!-- of
858 the --> <!-- <application>Privoxy</application> logo, --> of a checkerboard
859 pattern, a transparent 1x1 GIF image (aka <quote>blank</quote>), or a custom
860 URL of your choice. Note that to fit this category, the URL must match both
861 the <quote>+image</quote> and <quote>+block</quote> actions.
865 If you want to see nothing, then change the <quote>+image-blocker</quote>
866 action to <quote>+image-blocker{blank}</quote>. This can be done from the
867 <quote>Edit Actions List</quote> selection at <ulink
868 url="http://p.p/">http://p.p/</ulink>. Or by hand editing the appropriate
869 actions file. This will only effect what is defined as <quote>images</quote>
870 though. Also, any URLs that generate the bright red <quote>Blocked</quote>
871 banner, can be moved to the <quote>+image-blocker</quote> section for the
880 <title id="whyseeum">Why would anybody want to see a checkerboard pattern?</title>
882 This can be helpful for troubleshooting problems. It might also be good
883 for anyone new to <application>Privoxy</application> so that they can
884 see if their favorite pages are displaying correctly, and
885 <application>Privoxy</application> is not inadvertently removing something
892 <title id="blockedisugly">I see large red banners on some pages that say
893 <quote>Blocked</quote>. Why and how do I get rid of this?</title>
895 These are URLs that match something in one of
896 <application>Privoxy's</application> block actions (+block). It is meant
897 to be a warning so that you know something has been blocked and an easy way
898 for you to see why. These are handled differently than what has been defined
899 explicitly as <quote>images</quote> (e.g. ad banners). Depending on the
900 URL itself, it is sometimes hard for <application>Privoxy</application> to
901 really know whether it is indeed an ad image or not.
905 If you want them to be treated as if they were images, so that they can be
906 made invisible, then move the offending URL from the <quote>+block</quote>
907 section to the <quote>+imageblock</quote> section of your actions file. Just
908 be forewarned, if make any URL is made <quote>invisible</quote>, you may not
909 have any inkling that something has been removed from that page.
912 Alternately, you could modify the <quote><filename>block</filename></quote>
913 HTML template that is used by <application>Privoxy</application> to display
914 this, and make it something more to your liking.
919 <sect3 id="alliseeisred">
920 <title>I cannot see all of the <quote>Blocked</quote> page banner. All I
921 see is a bright red square.</title>
923 There is not enough space to fit the entire page. Try right clicking on the
924 visible, red portion, and select <quote>Show Frame</quote>, or equivalent.
925 This will usually allow you to see the entire Privoxy <quote>Blocked</quote>
926 page, and from there you can see just what is being blocked, and why.
930 <sect3 id="otherproxy">
931 <title>How can I make <application>Privoxy</application> work with other
932 proxies like <application>Squid</application>?</title>
934 This can be done. See the <ulink
935 url="../user-manual/configuration.html#FORWARDING">user manual</ulink>,
936 which describes how to do this.
944 <!-- ~~~~~ New section ~~~~~ -->
946 <sect2 id="misc"><title>Miscellaneous</title>
949 <title id="slowsme">How much does <application>Privoxy</application> slow my browsing down? This
950 has to add extra time to browsing.</title>
952 It should not slow you down any in real terms, and may actually help
953 speed things up since ads, banners and other junk are not being displayed.
954 The actual processing time required by <application>Privoxy</application>
955 itself for each page, is relatively small in the overall scheme of things,
956 and happens very quickly. This is typically more than offset by time saved
957 not downloading and rendering ad images.
961 <quote>Filtering</quote> via the <filename>filterfile</filename>
962 mechanism may cause a perceived slowdown, since the entire page is buffered
963 before displaying. See below.
970 <sect3 id="loadingtimes"><title>I noticed considerable
971 delays in page requests compared to the old Junkbuster. What's wrong?</title>
973 Using the default filtering configuration, I noticed considerable delays in
974 page requests compared to the old Junkbuster. Loading pages with large contents
975 seemed to take forever, then suddenly delivering all the content at once.
978 The whole content must be loaded in order to filter, and nothing is is
979 sent to the browser during this time. The loading time does not really
980 change in real numbers, but the feeling is different, because most
981 browsers are able to start rendering incomplete content, giving the
982 user a feeling of "it works".
985 To modify the content of a page (i.e. make frames resizeable again, etc.) and
986 not just replace ads, <application>Privoxy</application> needs to download the
987 entire page first, do its content magic and then send the page to the browser.
992 <sect3 id="configurl"><title>What is the "http://p.p/"?</title>
994 Since <application>Privoxy</application> sits between your web browser and the Internet, it can be
995 programmed to handle certain pages specially.
999 With recent versions of <application>Privoxy</application> (version 2.9.x), you can get some
1000 information about <application>Privoxy</application> and change some settings by going to
1001 http://p.p/ or, equivalently, http://www.privoxy.org/config/
1002 (Note that p.p is far easier to type but may not work in some
1007 These pages are *not* forwarded to a server on the Internet - instead they are
1008 handled by a special web server which is built in to <application>Privoxy</application>.
1012 If you are not running <application>Privoxy</application>, then http://p.p/ will fail, and
1013 http://www.privoxy.org/config/ will return a web page telling you
1014 you're not running <application>Privoxy</application>.
1018 If you have version 2.0.2, then the equivalent is
1019 http://example.com/show-proxy-args (but you get far less information, and you
1020 should really consider upgrading to 2.9.x).
1025 FIXME: commented out until we have data. HB 03/18/02.
1027 <sect3 id="badfiledesc"><title>I get the message 'Bad File Descriptor', why?</title>
1033 <sect3 id="proxy-chaining"><title>How do I chain <application>Privoxy</application> with other proxies
1034 (e.g. squid)?</title>
1041 <sect3 id="blocklist"><title>Do you still maintain the blocklists?</title>
1043 No. The format of the blocklists has changed significantly in the versions
1044 2.9.x. Once we have released the new stable version, v3.0, there will
1045 again be blocklists that you can update automatically.
1049 <sect3 id="newads"><title>How can I submit new ads?</title>
1051 As of now, please discontinue to submit new ad blocking infos. Once we
1052 have released the new version, there will again be a form on the website,
1053 which you can use to contribute new ads.
1057 <sect3 id="ip"><title>How can I hide my IP address?</title>
1059 You cannot hide your IP address with <application>Privoxy</application> or any other software, since
1060 the server needs to know your IP address to send the answer to you.
1063 Fortunately there are many publicly usable anonymous proxies out there, which
1064 solve the problem by providing a further level of indirection between you and
1065 the web server, shared by many people and thus letting your requests "drown"
1066 in white noise of unrelated requests as far as user tracking is concerned.
1069 Most of them will, however, log your IP address and make it available to the
1070 authorities in case you abuse that anonymity for criminal purposes. In fact
1071 you can't even rule out that some of them only exist to *collect* information
1072 on (those suspicious) people with a more than average preference for privacy.
1075 You can find a list of anonymous public proxies at <ulink
1076 url="http://www.multiproxy.org/anon_list.htm">multiproxy.org</ulink> and many
1077 more through Google.
1081 <!-- <sect3 id="image"><title>What is the imagefile (simage.ini, etc.) for?</title> -->
1083 <!-- Anytime <application>Privoxy</application> determines (with the help of the blocklist) that a URL -->
1084 <!-- contains an advertisement, it has to decide whether this advertisement is an -->
1085 <!-- image or not. <application>Privoxy</application> uses the imagefile for that purpose. -->
1090 <title id="anonforsure">Can <application>Privoxy</application> guarantee I am anonymous?</title>
1092 No. Your chances of remaining anonymous are greatly improved, but unless you
1093 are an expert on Internet security it would be safest to assume that
1094 everything you do on the Web can be traced back to you.
1097 <application>Privoxy</application> can remove various information about you,
1098 and allows <emphasis>you</emphasis> more freedom to decide which sites
1099 you can trust. But it's still possible that web sites can find out who you
1100 are. Here's one way this can happen.
1103 A few browsers disclose the user's email address in certain situations, such
1104 as when transferring a file by FTP. <application>Privoxy</application>
1105 does not filter FTP. If you need this feature, or are concerned about the
1106 mail handler of your browser disclosing your email address, you might
1107 consider products such as <application>NSClean</application>.
1110 Browsers available only as binaries could use non-standard headers to give
1111 out any information they can have access to: see the manufacturer's license
1112 agreement. It's impossible to anticipate and prevent every breach of privacy
1113 that might occur. The professionally paranoid prefer browsers available as
1114 source code, because anticipating their behavior is easier. Trust the source,
1121 <title id="sitebreak">Might some things break because header information is
1122 being altered?</title>
1125 Definitely. More and more sites use HTTP header content to decide what to
1126 display and how to display it. There is many ways that this can be handled,
1127 so having hard and fast rules, is tricky.
1131 <quote>USER AGENT</quote> in particular is often used in this way to identify
1132 the browser, and adjust content accordingly. Changing this now is not
1133 recommended, since so many sites do look for this. You may get undesirable
1134 results by changing this.
1138 For instance, different browsers use different encodings of Russian and Czech
1139 characters, certain web servers convert pages on-the-fly according to the
1140 User Agent header. Giving a <quote>User Agent</quote> with the wrong
1141 operating system or browser manufacturer causes some sites in these languages
1142 to be garbled; Surfers to Eastern European sites should change it to
1143 something closer. And then some page access counters work by looking at the
1144 <quote>REFERER</quote> header; they may fail or break if unavailable. The
1145 weather maps of Intellicast have been blocked by their server when no
1146 <quote>REFERER</quote> or cookie is provided, is another example. There are
1147 many, many other ways things can go wrong when trying to fool a web server.
1151 If you have problems with a site, you will have to adjust your configuration
1152 accordingly. Cookies are probably the most likely adjustment that may
1153 be required, but by no means the only one.
1161 <title id="caching">Can <application>Privoxy</application> act as a <quote>caching</quote> proxy to
1162 speed up web browsing?</title>
1164 No, it does not have this ability at all. You want something like
1165 <ulink url="http://www.squid-cache.org/">Squid</ulink> for this. And, yes,
1166 before you ask, <application>Privoxy</application> can co-exist
1167 with other kinds of proxies like <application>Squid</application>.
1172 <title id="firewall">What about as a firewall? Can <application>Privoxy</application> protect me?</title>
1174 Not in the way you mean, or in the way a true firewall can, or a proxy that
1175 has this specific capability. <application>Privoxy</application> can help
1176 protect your privacy, but not really protect you from intrusion attempts.
1182 <title id="logo">The <application>Privoxy</application> logo that replaces ads is very blocky
1183 and ugly looking. Can't a better font be used?</title>
1186 This is not a font problem. The logo is an image that is created by
1187 <application>Privoxy</application> on the fly. So as to not waste
1188 memory, the image is rather small. The blockiness comes when the
1189 image is scaled to fill a largish area. There is not much to be done
1190 about this, other than to use one of the other
1191 <quote>imageblock</quote> directives: <emphasis>pattern</emphasis>,
1192 <emphasis>blank</emphasis>, or a URL of your choosing.
1195 Given the above problem, we have decided to remove the logo option entirely
1202 <title id="wasted">I have large empty spaces now where ads used to be.
1205 It would be easy enough to just eliminate this space altogether, rather than
1206 fill it with blank space. But, this would create problems with many pages
1207 that use the overall size of the ad to help organize the page layout and
1208 position the various components of the page where they were intended to be.
1209 It is best left this way.
1215 <title id="ssl">How can <application>Privoxy</application> filter Secure (HTTPS) URLs?</title>
1217 This is a limitation since HTTPS transactions are encrypted SSL sessions
1218 between your browser and the secure site, and are meant to be reliably
1219 <emphasis>secure</emphasis> and private. This means that all cookies and HTTP
1220 header information are also encrypted from the time they leave your browser,
1221 to the site, and vice versa. <application>Privoxy</application> does not
1222 try to unencrypt this information, so it just passes through as is.
1223 <application>Privoxy</application> can still catch images and ads that
1224 are embedded in the SSL stream though.
1231 <title id="secure"><application>Privoxy</application> runs as a <quote>server</quote>. How
1232 secure is it? Do I need to take any special precautions?</title>
1234 There are no known exploits that might effect
1235 <application>Privoxy</application>. On Unix-like systems,
1236 <application>Privoxy</application> can run as a non-privileged
1237 user, which is how we recommend it be run. Also, by default
1238 <application>Privoxy</application> only listens to requests
1239 from <quote>localhost</quote>. The server aspect of
1240 <application>Privoxy</application> is not itself directly exposed to the
1241 Internet in this configuration. If you want to have
1242 <application>Privoxy</application> serve as a LAN proxy, this will have to
1243 be opened up to allow for LAN requests. In this case, we'd recommend
1244 you specify only the LAN gateway address, e.g. 192.168.1.1, in the main
1245 <application>Privoxy</application> config file. All LAN hosts can then use
1246 this as their proxy address in the browser proxy configuration. In this way,
1247 <application>Privoxy</application> will not listen on any external ports.
1248 Of course, a firewall is always good too. Better safe than sorry.
1253 <sect3 id="turnoff">
1254 <title>How can I temporarily disable <application>Privoxy</application>?</title>
1256 The easiest way is to access <application>Privoxy</application> with your
1257 browser by using the special URL: <ulink url="http://p.p/">http://p.p/</ulink>
1258 and select "Toggle Privoxy on or off" from that page.
1266 <!-- ~~~~~ New section ~~~~~ -->
1269 <title id="trouble">Troubleshooting</title>
1272 <title id="refused">I just upgraded and am getting <quote>connection refused</quote>
1273 with every web page?</title>
1275 Either <application>Privoxy</application> is not running, or your
1276 browser is configured for a different port than what
1277 <application>Privoxy</application> is using.
1281 The old <application>Privoxy</application> (and also
1282 <application>Junkbuster</application>) used port 8000 by
1283 default. This has been changed to port 8118 now, due to a conflict
1284 with NAS (Network Audio Service), which uses port 8000. If you haven't,
1285 you need to change your browser to the new port number, or alternately
1286 change <application>Privoxy's</application> <quote>listen-address</quote>
1287 setting in the <filename>config</filename> file used to start
1288 <application>Privoxy</application>.
1294 <title id="flushit">I just added a new rule, but the steenkin ad is
1295 still getting through. How?</title>
1297 If the ad had been displayed before you added its URL, it will probably be
1298 held in the browser's cache for some time, so it will be displayed without
1299 the need for any request to the server, and <application>Privoxy</application>
1300 will not be in the picture. The best thing to do is try flushing the browser's
1301 caches. And then try again.
1305 If this doesn't help, you probably have an error in the rule you
1306 applied. Try pasting the full URL of the offending ad into <ulink
1307 url="http://www.privoxy.org/config/show-url-info">http://www.privoxy.org/config/show-url-info</ulink>
1308 and see if any actions match your new rule.
1314 <title id="badsite">One of my favorite sites does not work with <application>Privoxy</application>.
1315 What can I do?</title>
1318 First verify that it is indeed a <application>Privoxy</application> problem,
1319 by disabling <application>Privoxy</application> filtering and blocking.
1320 Go to <ulink url="http://p.p/">http://p.p/</ulink> and click on
1321 <quote>Toggle Privoxy On or Off</quote>, then disable it. Now try that
1322 page again. It's probably a good idea to flush the browser cache as well.
1326 If still a problem, go to <quote>Show which actions apply to a URL and
1327 why</quote> from <ulink url="http://p.p/">http://p.p/</ulink> and paste
1328 the full URL of the page in question into the prompt. See which actions are
1329 being applied to the URL. Now, armed with this information, go to <quote>Edit
1330 the actions list</quote>. Here you should see various sections that have
1331 various <application>Privoxy</application> features disabled for specific
1332 sites. Disabled <quote>actions</quote> will have a <quote>-</quote> (minus
1333 sign) in front of them. Add your problem page URL to one of these sections
1334 that looks like it is disabling the feature that is causing the
1335 problem. Re-try the page. There might be some trial and error involved. This
1336 is discussed in a little more detail in the
1337 <ulink url="../user-manual/appendix.html#ACTIONSANAT">user-manual
1343 Alternately, if you are comfortable with a text editor, you can accomplish
1344 the same thing by editing the appropriate <quote>actions</quote> file.
1350 <title>Where can I get help? Report bugs? Feature Requests? Etc?</title>
1352 Feedback is encouraged, whether good, bad or ugly. Please see the contact
1353 page in the <ulink url="../user-manual/contact.html">user-manual</ulink> for
1361 <title id="time">What time is it?</title>
1372 <!-- ~~~~~ New section ~~~~~ -->
1374 FIXME: Commented out until we have something to put here. HB 03/18/02.
1375 <sect1 id="knownissues"><title>Known Issues</title>
1382 <!-- ~~~~~ New section ~~~~~ -->
1385 This is referenced in the doc header already. HB 03/25/02
1387 <sect1 id="contact"><title>Contact the developers</title>
1388 <para>Please see the user manual for information on how to contact the developers.
1392 <!-- ~~~~~ New section ~~~~~ -->
1393 <sect1 id="copyright"><title>Copyright and History</title>
1396 <ulink url="../user-manual/copyright.html#HISTORY">user-manual</ulink> for
1397 information on Copyright and History.
1401 <!-- ~~~~~ New section ~~~~~ -->
1402 <sect1 id="seealso"><title>See also</title>
1405 <ulink url="../user-manual/seealso.html">user-manual</ulink> for
1412 Tue 09/11/01 06:38:14 PM EST: Test SGML doc by Hal Burgiss.
1414 Last modified: Mon Sep 10 19:22:09 CEST 2001
1416 This program is free software; you can redistribute it
1417 and/or modify it under the terms of the GNU General
1418 Public License as published by the Free Software
1419 Foundation; either version 2 of the License, or (at
1420 your option) any later version.
1422 This program is distributed in the hope that it will
1423 be useful, but WITHOUT ANY WARRANTY; without even the
1424 implied warranty of MERCHANTABILITY or FITNESS FOR A
1425 PARTICULAR PURPOSE. See the GNU General Public
1426 License for more details.
1428 The GNU General Public License should be included with
1429 this file. If not, you can view it at
1430 http://www.gnu.org/copyleft/gpl.html
1431 or write to the Free Software Foundation, Inc., 59
1432 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
1435 Revision 1.33 2002/03/29 01:31:48 hal9
1436 Several new Q/A's and other touch ups.
1438 Revision 1.32 2002/03/27 00:57:03 hal9
1439 Touch ups for name change.
1441 Revision 1.31 2002/03/26 22:29:55 swa
1442 we have a new homepage!
1444 Revision 1.30 2002/03/25 16:39:22 hal9
1445 A few new sections. Made all links relative to user-manual.
1447 Revision 1.29 2002/03/25 05:23:57 hal9
1448 Moved section, and touch ups.
1450 Revision 1.28 2002/03/25 04:27:33 hal9
1451 New section related to name change.
1453 Revision 1.25 2002/03/24 16:08:08 swa
1454 we are too lazy to make a block-built
1455 privoxy logo. hence removed the option.
1457 Revision 1.24 2002/03/24 15:46:20 swa
1458 name change related issue.
1460 Revision 1.23 2002/03/24 12:33:01 swa
1463 Revision 1.22 2002/03/24 11:51:00 swa
1464 name change. changed filenames.
1466 Revision 1.21 2002/03/24 11:01:06 swa
1469 Revision 1.20 2002/03/23 15:13:11 swa
1470 renamed every reference to the old name with foobar.
1471 fixed "application foobar application" tag, fixed
1472 "the foobar" with "foobar". left junkbustser in cvs
1473 comments and remarks to history untouched.
1475 Revision 1.19 2002/03/21 17:01:54 hal9
1478 Revision 1.18 2002/03/18 16:40:31 hal9
1481 Revision 1.17 2002/03/18 03:53:53 hal9
1484 Revision 1.16 2002/03/17 21:32:56 hal9
1485 A few more additions.
1487 Revision 1.15 2002/03/17 07:25:59 hal9
1488 Correcting some of my typos, and some additions.
1490 Revision 1.14 2002/03/17 02:39:13 hal9
1491 A little more added ...
1493 Revision 1.13 2002/03/17 00:22:20 hal9
1494 Adding new stuff, and trying to incorporate stuff from old faq.
1496 Revision 1.12 2002/03/11 20:13:21 swa
1499 Revision 1.11 2002/03/11 18:42:27 swa
1502 Revision 1.10 2002/03/11 13:13:27 swa
1503 correct feedback channels
1505 Revision 1.9 2002/03/10 23:34:04 swa
1506 more info on not hiding ip address
1508 Revision 1.8 2002/03/09 15:55:48 swa
1509 added default config section
1511 Revision 1.7 2002/03/07 18:16:55 swa
1514 Revision 1.6 2002/03/07 13:16:31 oes
1515 Committing changes by Stefan
1517 Revision 1.5 2002/03/02 15:50:04 swa
1518 2.9.11 version. more input for docs.
1520 Revision 1.4 2002/02/24 14:34:24 jongfoster
1521 Formatting changes. Now changing the doctype to DocBook XML 4.1
1522 will work - no other changes are needed.
1524 Revision 1.3 2001/09/23 10:13:48 swa
1525 upload process established. run make webserver and
1526 the documentation is moved to the webserver. documents
1527 are now linked correctly.
1529 Revision 1.2 2001/09/13 15:20:17 swa
1530 merged standards into developer manual
1532 Revision 1.1 2001/09/12 15:36:41 swa
1533 source files for junkbuster documentation
1535 Revision 1.3 2001/09/10 17:43:59 swa
1536 first proposal of a structure.
1538 Revision 1.2 2001/06/13 14:28:31 swa
1539 docs should have an author.
1541 Revision 1.1 2001/06/13 14:20:37 swa
1542 first import of project's documentation for the webserver.