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9 $Id: faq.sgml,v 1.34 2002/03/29 04:35:56 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 1.34 2002/03/29 04:35:56 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
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://config.privoxy.org">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 <ulink url="http://p.p/">http://p.p/</ulink> or, equivalently, <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
1002 (Note that p.p is far easier to type but may not work in some
1003 configurations. With the name change to <application>Privoxy</application>,
1004 this is changed from the previous http://i.j.b/ or earlier 2.9.x versions).
1008 These pages are <emphasis>not</emphasis> forwarded to a server on the Internet
1009 - instead they are handled by a special web server which is built in to
1010 <application>Privoxy</application>.
1014 If you are not running <application>Privoxy</application>, then <ulink
1015 url="http://p.p/">http://p.p/</ulink> will fail, and <ulink
1016 url="http://config.privoxy.org/">http://config.privoxy.org/</ulink> will
1017 return a web page telling you you're not running
1018 <application>Privoxy</application>.
1022 If you have version 2.0.2, then the equivalent is
1023 http://example.com/show-proxy-args (but you get far less information, and you
1024 should really consider upgrading to 2.9.x).
1029 FIXME: commented out until we have data. HB 03/18/02.
1031 <sect3 id="badfiledesc"><title>I get the message 'Bad File Descriptor', why?</title>
1037 <sect3 id="proxy-chaining"><title>How do I chain <application>Privoxy</application> with other proxies
1038 (e.g. squid)?</title>
1045 <sect3 id="blocklist"><title>Do you still maintain the blocklists?</title>
1047 No. The format of the blocklists has changed significantly in the versions
1048 2.9.x. Once we have released the new stable version, v3.0, there will
1049 again be blocklists that you can update automatically.
1053 <sect3 id="newads"><title>How can I submit new ads?</title>
1055 As of now, please discontinue to submit new ad blocking infos. Once we
1056 have released the new version, there will again be a form on the website,
1057 which you can use to contribute new ads.
1061 <sect3 id="ip"><title>How can I hide my IP address?</title>
1063 You cannot hide your IP address with <application>Privoxy</application> or any other software, since
1064 the server needs to know your IP address to send the answer to you.
1067 Fortunately there are many publicly usable anonymous proxies out there, which
1068 solve the problem by providing a further level of indirection between you and
1069 the web server, shared by many people and thus letting your requests "drown"
1070 in white noise of unrelated requests as far as user tracking is concerned.
1073 Most of them will, however, log your IP address and make it available to the
1074 authorities in case you abuse that anonymity for criminal purposes. In fact
1075 you can't even rule out that some of them only exist to *collect* information
1076 on (those suspicious) people with a more than average preference for privacy.
1079 You can find a list of anonymous public proxies at <ulink
1080 url="http://www.multiproxy.org/anon_list.htm">multiproxy.org</ulink> and many
1081 more through Google.
1085 <!-- <sect3 id="image"><title>What is the imagefile (simage.ini, etc.) for?</title> -->
1087 <!-- Anytime <application>Privoxy</application> determines (with the help of the blocklist) that a URL -->
1088 <!-- contains an advertisement, it has to decide whether this advertisement is an -->
1089 <!-- image or not. <application>Privoxy</application> uses the imagefile for that purpose. -->
1094 <title id="anonforsure">Can <application>Privoxy</application> guarantee I am anonymous?</title>
1096 No. Your chances of remaining anonymous are greatly improved, but unless you
1097 are an expert on Internet security it would be safest to assume that
1098 everything you do on the Web can be traced back to you.
1101 <application>Privoxy</application> can remove various information about you,
1102 and allows <emphasis>you</emphasis> more freedom to decide which sites
1103 you can trust. But it's still possible that web sites can find out who you
1104 are. Here's one way this can happen.
1107 A few browsers disclose the user's email address in certain situations, such
1108 as when transferring a file by FTP. <application>Privoxy</application>
1109 does not filter FTP. If you need this feature, or are concerned about the
1110 mail handler of your browser disclosing your email address, you might
1111 consider products such as <application>NSClean</application>.
1114 Browsers available only as binaries could use non-standard headers to give
1115 out any information they can have access to: see the manufacturer's license
1116 agreement. It's impossible to anticipate and prevent every breach of privacy
1117 that might occur. The professionally paranoid prefer browsers available as
1118 source code, because anticipating their behavior is easier. Trust the source,
1125 <title id="sitebreak">Might some things break because header information is
1126 being altered?</title>
1129 Definitely. More and more sites use HTTP header content to decide what to
1130 display and how to display it. There is many ways that this can be handled,
1131 so having hard and fast rules, is tricky.
1135 <quote>USER AGENT</quote> in particular is often used in this way to identify
1136 the browser, and adjust content accordingly. Changing this now is not
1137 recommended, since so many sites do look for this. You may get undesirable
1138 results by changing this.
1142 For instance, different browsers use different encodings of Russian and Czech
1143 characters, certain web servers convert pages on-the-fly according to the
1144 User Agent header. Giving a <quote>User Agent</quote> with the wrong
1145 operating system or browser manufacturer causes some sites in these languages
1146 to be garbled; Surfers to Eastern European sites should change it to
1147 something closer. And then some page access counters work by looking at the
1148 <quote>REFERER</quote> header; they may fail or break if unavailable. The
1149 weather maps of Intellicast have been blocked by their server when no
1150 <quote>REFERER</quote> or cookie is provided, is another example. There are
1151 many, many other ways things can go wrong when trying to fool a web server.
1155 If you have problems with a site, you will have to adjust your configuration
1156 accordingly. Cookies are probably the most likely adjustment that may
1157 be required, but by no means the only one.
1165 <title id="caching">Can <application>Privoxy</application> act as a <quote>caching</quote> proxy to
1166 speed up web browsing?</title>
1168 No, it does not have this ability at all. You want something like
1169 <ulink url="http://www.squid-cache.org/">Squid</ulink> for this. And, yes,
1170 before you ask, <application>Privoxy</application> can co-exist
1171 with other kinds of proxies like <application>Squid</application>.
1176 <title id="firewall">What about as a firewall? Can <application>Privoxy</application> protect me?</title>
1178 Not in the way you mean, or in the way a true firewall can, or a proxy that
1179 has this specific capability. <application>Privoxy</application> can help
1180 protect your privacy, but not really protect you from intrusion attempts.
1186 <title id="logo">The <application>Privoxy</application> logo that replaces ads is very blocky
1187 and ugly looking. Can't a better font be used?</title>
1190 This is not a font problem. The logo is an image that is created by
1191 <application>Privoxy</application> on the fly. So as to not waste
1192 memory, the image is rather small. The blockiness comes when the
1193 image is scaled to fill a largish area. There is not much to be done
1194 about this, other than to use one of the other
1195 <quote>imageblock</quote> directives: <emphasis>pattern</emphasis>,
1196 <emphasis>blank</emphasis>, or a URL of your choosing.
1199 Given the above problem, we have decided to remove the logo option entirely
1206 <title id="wasted">I have large empty spaces now where ads used to be.
1209 It would be easy enough to just eliminate this space altogether, rather than
1210 fill it with blank space. But, this would create problems with many pages
1211 that use the overall size of the ad to help organize the page layout and
1212 position the various components of the page where they were intended to be.
1213 It is best left this way.
1219 <title id="ssl">How can <application>Privoxy</application> filter Secure (HTTPS) URLs?</title>
1221 This is a limitation since HTTPS transactions are encrypted SSL sessions
1222 between your browser and the secure site, and are meant to be reliably
1223 <emphasis>secure</emphasis> and private. This means that all cookies and HTTP
1224 header information are also encrypted from the time they leave your browser,
1225 to the site, and vice versa. <application>Privoxy</application> does not
1226 try to unencrypt this information, so it just passes through as is.
1227 <application>Privoxy</application> can still catch images and ads that
1228 are embedded in the SSL stream though.
1235 <title id="secure"><application>Privoxy</application> runs as a <quote>server</quote>. How
1236 secure is it? Do I need to take any special precautions?</title>
1238 There are no known exploits that might effect
1239 <application>Privoxy</application>. On Unix-like systems,
1240 <application>Privoxy</application> can run as a non-privileged
1241 user, which is how we recommend it be run. Also, by default
1242 <application>Privoxy</application> only listens to requests
1243 from <quote>localhost</quote>. The server aspect of
1244 <application>Privoxy</application> is not itself directly exposed to the
1245 Internet in this configuration. If you want to have
1246 <application>Privoxy</application> serve as a LAN proxy, this will have to
1247 be opened up to allow for LAN requests. In this case, we'd recommend
1248 you specify only the LAN gateway address, e.g. 192.168.1.1, in the main
1249 <application>Privoxy</application> config file. All LAN hosts can then use
1250 this as their proxy address in the browser proxy configuration. In this way,
1251 <application>Privoxy</application> will not listen on any external ports.
1252 Of course, a firewall is always good too. Better safe than sorry.
1257 <sect3 id="turnoff">
1258 <title>How can I temporarily disable <application>Privoxy</application>?</title>
1260 The easiest way is to access <application>Privoxy</application> with your
1261 browser by using the special URL: <ulink url="http://p.p/">http://p.p/</ulink>
1262 and select "Toggle Privoxy on or off" from that page.
1270 <!-- ~~~~~ New section ~~~~~ -->
1273 <title id="trouble">Troubleshooting</title>
1276 <title id="refused">I just upgraded and am getting <quote>connection refused</quote>
1277 with every web page?</title>
1279 Either <application>Privoxy</application> is not running, or your
1280 browser is configured for a different port than what
1281 <application>Privoxy</application> is using.
1285 The old <application>Privoxy</application> (and also
1286 <application>Junkbuster</application>) used port 8000 by
1287 default. This has been changed to port 8118 now, due to a conflict
1288 with NAS (Network Audio Service), which uses port 8000. If you haven't,
1289 you need to change your browser to the new port number, or alternately
1290 change <application>Privoxy's</application> <quote>listen-address</quote>
1291 setting in the <filename>config</filename> file used to start
1292 <application>Privoxy</application>.
1298 <title id="flushit">I just added a new rule, but the steenkin ad is
1299 still getting through. How?</title>
1301 If the ad had been displayed before you added its URL, it will probably be
1302 held in the browser's cache for some time, so it will be displayed without
1303 the need for any request to the server, and <application>Privoxy</application>
1304 will not be in the picture. The best thing to do is try flushing the browser's
1305 caches. And then try again.
1309 If this doesn't help, you probably have an error in the rule you
1310 applied. Try pasting the full URL of the offending ad into <ulink
1311 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
1312 and see if any actions match your new rule.
1318 <title id="badsite">One of my favorite sites does not work with <application>Privoxy</application>.
1319 What can I do?</title>
1322 First verify that it is indeed a <application>Privoxy</application> problem,
1323 by disabling <application>Privoxy</application> filtering and blocking.
1324 Go to <ulink url="http://p.p/">http://p.p/</ulink> and click on
1325 <quote>Toggle Privoxy On or Off</quote>, then disable it. Now try that
1326 page again. It's probably a good idea to flush the browser cache as well.
1330 If still a problem, go to <quote>Show which actions apply to a URL and
1331 why</quote> from <ulink url="http://p.p/">http://p.p/</ulink> and paste
1332 the full URL of the page in question into the prompt. See which actions are
1333 being applied to the URL. Now, armed with this information, go to <quote>Edit
1334 the actions list</quote>. Here you should see various sections that have
1335 various <application>Privoxy</application> features disabled for specific
1336 sites. Disabled <quote>actions</quote> will have a <quote>-</quote> (minus
1337 sign) in front of them. Add your problem page URL to one of these sections
1338 that looks like it is disabling the feature that is causing the
1339 problem. Re-try the page. There might be some trial and error involved. This
1340 is discussed in a little more detail in the
1341 <ulink url="../user-manual/appendix.html#ACTIONSANAT">user-manual
1347 Alternately, if you are comfortable with a text editor, you can accomplish
1348 the same thing by editing the appropriate <quote>actions</quote> file.
1354 <title>Where can I get help? Report bugs? Feature Requests? Etc?</title>
1356 Feedback is encouraged, whether good, bad or ugly. Please see the contact
1357 page in the <ulink url="../user-manual/contact.html">user-manual</ulink> for
1365 <title id="time">What time is it?</title>
1376 <!-- ~~~~~ New section ~~~~~ -->
1378 FIXME: Commented out until we have something to put here. HB 03/18/02.
1379 <sect1 id="knownissues"><title>Known Issues</title>
1386 <!-- ~~~~~ New section ~~~~~ -->
1389 This is referenced in the doc header already. HB 03/25/02
1391 <sect1 id="contact"><title>Contact the developers</title>
1392 <para>Please see the user manual for information on how to contact the developers.
1396 <!-- ~~~~~ New section ~~~~~ -->
1397 <sect1 id="copyright"><title>Copyright and History</title>
1400 <ulink url="../user-manual/copyright.html#HISTORY">user-manual</ulink> for
1401 information on Copyright and History.
1405 <!-- ~~~~~ New section ~~~~~ -->
1406 <sect1 id="seealso"><title>See also</title>
1409 <ulink url="../user-manual/seealso.html">user-manual</ulink> for
1416 Tue 09/11/01 06:38:14 PM EST: Test SGML doc by Hal Burgiss.
1418 Last modified: Mon Sep 10 19:22:09 CEST 2001
1420 This program is free software; you can redistribute it
1421 and/or modify it under the terms of the GNU General
1422 Public License as published by the Free Software
1423 Foundation; either version 2 of the License, or (at
1424 your option) any later version.
1426 This program is distributed in the hope that it will
1427 be useful, but WITHOUT ANY WARRANTY; without even the
1428 implied warranty of MERCHANTABILITY or FITNESS FOR A
1429 PARTICULAR PURPOSE. See the GNU General Public
1430 License for more details.
1432 The GNU General Public License should be included with
1433 this file. If not, you can view it at
1434 http://www.gnu.org/copyleft/gpl.html
1435 or write to the Free Software Foundation, Inc., 59
1436 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
1439 Revision 1.34 2002/03/29 04:35:56 hal9
1442 Revision 1.33 2002/03/29 01:31:48 hal9
1443 Several new Q/A's and other touch ups.
1445 Revision 1.32 2002/03/27 00:57:03 hal9
1446 Touch ups for name change.
1448 Revision 1.31 2002/03/26 22:29:55 swa
1449 we have a new homepage!
1451 Revision 1.30 2002/03/25 16:39:22 hal9
1452 A few new sections. Made all links relative to user-manual.
1454 Revision 1.29 2002/03/25 05:23:57 hal9
1455 Moved section, and touch ups.
1457 Revision 1.28 2002/03/25 04:27:33 hal9
1458 New section related to name change.
1460 Revision 1.25 2002/03/24 16:08:08 swa
1461 we are too lazy to make a block-built
1462 privoxy logo. hence removed the option.
1464 Revision 1.24 2002/03/24 15:46:20 swa
1465 name change related issue.
1467 Revision 1.23 2002/03/24 12:33:01 swa
1470 Revision 1.22 2002/03/24 11:51:00 swa
1471 name change. changed filenames.
1473 Revision 1.21 2002/03/24 11:01:06 swa
1476 Revision 1.20 2002/03/23 15:13:11 swa
1477 renamed every reference to the old name with foobar.
1478 fixed "application foobar application" tag, fixed
1479 "the foobar" with "foobar". left junkbustser in cvs
1480 comments and remarks to history untouched.
1482 Revision 1.19 2002/03/21 17:01:54 hal9
1485 Revision 1.18 2002/03/18 16:40:31 hal9
1488 Revision 1.17 2002/03/18 03:53:53 hal9
1491 Revision 1.16 2002/03/17 21:32:56 hal9
1492 A few more additions.
1494 Revision 1.15 2002/03/17 07:25:59 hal9
1495 Correcting some of my typos, and some additions.
1497 Revision 1.14 2002/03/17 02:39:13 hal9
1498 A little more added ...
1500 Revision 1.13 2002/03/17 00:22:20 hal9
1501 Adding new stuff, and trying to incorporate stuff from old faq.
1503 Revision 1.12 2002/03/11 20:13:21 swa
1506 Revision 1.11 2002/03/11 18:42:27 swa
1509 Revision 1.10 2002/03/11 13:13:27 swa
1510 correct feedback channels
1512 Revision 1.9 2002/03/10 23:34:04 swa
1513 more info on not hiding ip address
1515 Revision 1.8 2002/03/09 15:55:48 swa
1516 added default config section
1518 Revision 1.7 2002/03/07 18:16:55 swa
1521 Revision 1.6 2002/03/07 13:16:31 oes
1522 Committing changes by Stefan
1524 Revision 1.5 2002/03/02 15:50:04 swa
1525 2.9.11 version. more input for docs.
1527 Revision 1.4 2002/02/24 14:34:24 jongfoster
1528 Formatting changes. Now changing the doctype to DocBook XML 4.1
1529 will work - no other changes are needed.
1531 Revision 1.3 2001/09/23 10:13:48 swa
1532 upload process established. run make webserver and
1533 the documentation is moved to the webserver. documents
1534 are now linked correctly.
1536 Revision 1.2 2001/09/13 15:20:17 swa
1537 merged standards into developer manual
1539 Revision 1.1 2001/09/12 15:36:41 swa
1540 source files for junkbuster documentation
1542 Revision 1.3 2001/09/10 17:43:59 swa
1543 first proposal of a structure.
1545 Revision 1.2 2001/06/13 14:28:31 swa
1546 docs should have an author.
1548 Revision 1.1 2001/06/13 14:20:37 swa
1549 first import of project's documentation for the webserver.