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9 $Id: faq.sgml,v 1.35 2002/03/30 04:14:19 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 1.35 2002/03/30 04:14:19 hal9 Exp $</pubdate>
28 <orgname>By: Privoxy Developers</orgname>
35 This FAQ gives users and developers alike answers to frequently asked
36 questions about <ulink url="http://www.privoxy.org">Privoxy</ulink>.
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 <application>Privoxy</application>, configuration from version 2.0.x to
536 2.9.x and later. Most of the older files will not work at all. This is
537 especially true of <filename>blocklist</filename>. If this is the case, you
538 will need to re-enter your old data into the new configuration structure.
539 This is probably also a good recommendation even if upgrading from 2.9.x to
540 3.x since there were many minor changes along the way.
545 <title id="actionsfile">What is an <quote>actions</quote> file?</title>
548 <quote>actions</quote> files are where various actions that
549 <application>Privoxy</application> might take, are configured.
550 Typically, you would define a set of default actions that apply
551 to all URLs, then add exceptions to these defaults.
555 Actions can be defined on a per site basis, or for groups of sites. Actions
556 can also be grouped together and then applied to one or more sites. There
557 are many possible actions that might apply to any given site. As an example,
558 if we are blocking cookies as one of our default
559 <application>actions</application>, but need to accept cookies from a given
560 site, we would define this in our <quote>actions</quote> file.
565 <application>Privoxy</application> comes with several default
566 <application>actions</application> files, with varying degrees
567 of filtering and blocking, as starting points for your own
568 configuration (see below).
573 <sect3 id="actionss">
574 <title>The <quote>actions</quote>concept confuses me. Please list
575 some of these <quote>actions</quote>.</title>
577 These are all explained in the
578 <ulink url="../user-manual/configuration.html#ACTIONSFILE">user-manual</ulink>.
579 Please refer to that.
585 <title id="actconfig">How are actions files configured? What is the easiest
586 way to do this?</title>
589 The easiest way to do this, is to access <application>Privoxy</application>
590 with your web browser at <ulink url="http://p.p/">http://p.p/</ulink>,
592 "<ulink url="http://config.privoxy.org">Edit the actions list</ulink>"
593 from the selection list. You can also do this by editing the appropriate
594 file with a text editor.
600 url="../user-manual/configuration.html#ACTIONSFILE">user-manual</ulink> for a
601 detailed explanation of these and other configuration files, and their
602 various options and syntax.
608 FIXME: Commenting these out until we have some data there. HB 03/17/02.
610 <sect3 id="yahoo"><title>How can I make my Yahoo account work?</title>
616 <sect3 id="hotmail"> <title>How can I make my Hotmail account work?</title>
622 <sect3 id="gmx"> <title>How can I make my GMX account work?</title>
629 <sect3 id="configfiles"> <title>What are the differences between
630 intermediate.action, basic.action, etc.?</title>
632 Configuring <application>Privoxy</application> is not easy. To help you get
633 started, we provide you with three different default configurations. The
634 following table shows you, which features are enabled in each configuration.
637 <table frame=all><title>Default Configurations</title>
638 <tgroup cols=5 align=left colsep=1 rowsep=1>
646 <entry>Feature</entry>
647 <entry>default.action</entry>
648 <entry>basic.action</entry>
649 <entry>intermediate.action</entry>
650 <entry>advanced.action</entry>
656 <!-- <entry>f1</entry> -->
657 <!-- <entry>f2</entry> -->
658 <!-- <entry>f3</entry> -->
659 <!-- <entry>f4</entry> -->
660 <!-- <entry>f5</entry> -->
667 <entry>ad-filtering</entry>
675 <entry>blank image</entry>
683 <entry>de-animate GIFs</entry>
691 <entry>referer forging</entry>
699 <entry>jon's +no-cookies-keep (i.e. session cookies only)</entry>
707 <entry>no-popup windows</entry>
715 <entry>fast redirects</entry>
723 <entry>hide-referrer</entry>
731 <entry>hide-useragent</entry>
739 <entry>content-modification</entry>
747 <entry>feature-x</entry>
755 <entry>feature-y</entry>
763 <entry>feature-z</entry>
776 <sect3 id="browseconfig"> <title>Why can I change the configuration with a
777 browser? Does that not raise security issues?</title>
779 What I don't understand, is how I can browser edit the config file as a
780 regular user, while the whole /etc/privoxy hierarchy belongs to the user
781 "privoxy", with only 644 perms.
784 When you use the browser-based editor, <application>Privoxy</application>
785 itself is writing to the config files. Because
786 <application>Privoxy</application> is running as the user "privoxy", it can
787 update the config files.
790 If you don't like this, setting "enable-edit-actions 0" in the config file
791 will disable the browser-based editor. If you're that paranoid, you should
792 also consider setting "enable-remote-toggle 0" to prevent browser-based
793 enabling/disabling of <application>Privoxy</application>.
796 Note that normally only local users can connect to <application>Privoxy</application>, so this is not
797 (normally) a security problem.
803 <title id="filterfile">What is <quote>default.filter</quote>?</title>
805 The <quote>default.filter</quote> file is used to <quote>filter</quote> any
806 web page content. By <quote>filtering</quote> we mean it can modify, remove,
807 or change <emphasis>anything</emphasis> on the page, including HTML tags, and
808 JavaScript. Regular expressions are used to accomplish this, and operate
809 on a line by line basis. This is potentially a very powerful feature, but
810 requires some expertise.
814 If you are familiar with regular expressions, and HTML, you can look at
815 the provided <filename>default.filter</filename> with a text editor and see
816 some of things it can be used for.
820 Presently, there is no GUI editor option for this part of the configuration,
821 but you can disable/enable various sections of the included default
822 file with the <quote>Actions List Editor</quote> from your browser.
828 <title id="lanconfig">How can I set up <application>Privoxy</application> to act as a proxy for my
831 By default, <application>Privoxy</application> only responds to requests
832 from localhost. To have it act as a server for a network, this needs to be
833 changed in the main config file where the <application>Privoxy</application>
834 configuration is located. In that file is a <quote>listen-address</quote>
835 option. It may be commented out with a <quote>#</quote> symbol. Make sure
836 it is uncommented, and assign it the address of the LAN gateway interface,
837 and port number to use:
842 listen-address 192.168.1.1:8118
847 Save the file, and restart <application>Privoxy</application>. Configure
848 all browsers on the network then to use this address and port number.
855 <title id="noseeum">Instead of ads, now I get a checkerboard pattern. I don't want to see anything.</title>
857 This is a configuration option for images that
858 <application>Privoxy</application> is stopping. You have the choice <!-- of
859 the --> <!-- <application>Privoxy</application> logo, --> of a checkerboard
860 pattern, a transparent 1x1 GIF image (aka <quote>blank</quote>), or a custom
861 URL of your choice. Note that to fit this category, the URL must match both
862 the <quote>+image</quote> and <quote>+block</quote> actions.
866 If you want to see nothing, then change the <quote>+image-blocker</quote>
867 action to <quote>+image-blocker{blank}</quote>. This can be done from the
868 <quote>Edit Actions List</quote> selection at <ulink
869 url="http://p.p/">http://p.p/</ulink>. Or by hand editing the appropriate
870 actions file. This will only effect what is defined as <quote>images</quote>
871 though. Also, any URLs that generate the bright red <quote>Blocked</quote>
872 banner, can be moved to the <quote>+image-blocker</quote> section for the
881 <title id="whyseeum">Why would anybody want to see a checkerboard pattern?</title>
883 This can be helpful for troubleshooting problems. It might also be good
884 for anyone new to <application>Privoxy</application> so that they can
885 see if their favorite pages are displaying correctly, and
886 <application>Privoxy</application> is not inadvertently removing something
893 <title id="blockedisugly">I see large red banners on some pages that say
894 <quote>Blocked</quote>. Why and how do I get rid of this?</title>
896 These are URLs that match something in one of
897 <application>Privoxy's</application> block actions (+block). It is meant
898 to be a warning so that you know something has been blocked and an easy way
899 for you to see why. These are handled differently than what has been defined
900 explicitly as <quote>images</quote> (e.g. ad banners). Depending on the
901 URL itself, it is sometimes hard for <application>Privoxy</application> to
902 really know whether it is indeed an ad image or not. And there are
903 limitations as to what <application>Privoxy</application> can do to
904 <quote>fool</quote> the browser.
908 For instance, if the ad is in a frame, then it is embedded in the separate
909 HTML page used for the frame. In this case, you cannot just substitute an
910 aribitray image (like we would for a <quote>blank</quote> image), for an HTML
911 page. The browser is expecting an HTML page, and that is what it must have
912 for frames. So this situation can be a little trickier to deal with, and
913 <application>Privoxy</application> will use the <quote>Blocked</quote> page.
917 If you want these to be treated as if they were images, so that they can be
918 made invisible, you can try moving the offending URL from the
919 <quote>+block</quote> section to the <quote>+imageblock</quote> section of
920 your actions file. Just be forewarned, if any URL is made
921 <quote>invisible</quote>, you may not have any inkling that something has
922 been removed from that page. If this approach does not work, then you are
923 probably dealing with a frame (or <quote>ilayer</quote>), and the only thing
924 that can go there is an HTML page of some sort.
927 To deal with this situation, you could modify the
928 <quote><filename>block</filename></quote> HTML template that is used by
929 <application>Privoxy</application> to display this, and make it something
930 more to your liking. Currently, there is no configuration option for this.
931 You will have to modify, or create your own page, and use this to replace
932 <filename>templates/blocked</filename>, which is what
933 <application>Privoxy</application> uses to display the <quote>Blocked</quote>
937 Another way to deal with this is find why and where
938 <application>Privoxy</application> is blocking the frame, and
939 diable this. Then let the <quote>+image-blocker</quote> action
940 handle the ad that is embedded in the frame's HTML page.
945 <sect3 id="alliseeisred">
946 <title>I cannot see all of the <quote>Blocked</quote> page banner. All I
947 see is a bright red square.</title>
949 There is not enough space to fit the entire page. Try right clicking on the
950 visible, red portion, and select <quote>Show Frame</quote>, or equivalent.
951 This will usually allow you to see the entire Privoxy <quote>Blocked</quote>
952 page, and from there you can see just what is being blocked, and why.
956 <sect3 id="otherproxy">
957 <title>How can I make <application>Privoxy</application> work with other
958 proxies like <application>Squid</application>?</title>
960 This can be done. See the <ulink
961 url="../user-manual/configuration.html#FORWARDING">user manual</ulink>,
962 which describes how to do this.
970 <!-- ~~~~~ New section ~~~~~ -->
972 <sect2 id="misc"><title>Miscellaneous</title>
975 <title id="slowsme">How much does <application>Privoxy</application> slow my browsing down? This
976 has to add extra time to browsing.</title>
978 It should not slow you down any in real terms, and may actually help
979 speed things up since ads, banners and other junk are not being displayed.
980 The actual processing time required by <application>Privoxy</application>
981 itself for each page, is relatively small in the overall scheme of things,
982 and happens very quickly. This is typically more than offset by time saved
983 not downloading and rendering ad images.
987 <quote>Filtering</quote> via the <filename>filterfile</filename>
988 mechanism may cause a perceived slowdown, since the entire page is buffered
989 before displaying. See below.
996 <sect3 id="loadingtimes"><title>I noticed considerable
997 delays in page requests compared to the old Junkbuster. What's wrong?</title>
999 Using the default filtering configuration, I noticed considerable delays in
1000 page requests compared to the old Junkbuster. Loading pages with large contents
1001 seemed to take forever, then suddenly delivering all the content at once.
1004 The whole content must be loaded in order to filter, and nothing is is
1005 sent to the browser during this time. The loading time does not really
1006 change in real numbers, but the feeling is different, because most
1007 browsers are able to start rendering incomplete content, giving the
1008 user a feeling of "it works".
1011 To modify the content of a page (i.e. make frames resizeable again, etc.) and
1012 not just replace ads, <application>Privoxy</application> needs to download the
1013 entire page first, do its content magic and then send the page to the browser.
1018 <sect3 id="configurl"><title>What is the "http://p.p/"?</title>
1020 Since <application>Privoxy</application> sits between your web browser and the Internet, it can be
1021 programmed to handle certain pages specially.
1025 With recent versions of <application>Privoxy</application> (version 2.9.x), you can get some
1026 information about <application>Privoxy</application> and change some settings by going to
1027 <ulink url="http://p.p/">http://p.p/</ulink> or, equivalently, <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
1028 (Note that p.p is far easier to type but may not work in some
1029 configurations. With the name change to <application>Privoxy</application>,
1030 this is changed from the previous http://i.j.b/ or earlier 2.9.x versions).
1034 These pages are <emphasis>not</emphasis> forwarded to a server on the Internet
1035 - instead they are handled by a special web server which is built in to
1036 <application>Privoxy</application>.
1040 If you are not running <application>Privoxy</application>, then <ulink
1041 url="http://p.p/">http://p.p/</ulink> will fail, and <ulink
1042 url="http://config.privoxy.org/">http://config.privoxy.org/</ulink> will
1043 return a web page telling you you're not running
1044 <application>Privoxy</application>.
1048 If you have version 2.0.2, then the equivalent is
1049 http://example.com/show-proxy-args (but you get far less information, and you
1050 should really consider upgrading to 2.9.x).
1055 FIXME: commented out until we have data. HB 03/18/02.
1057 <sect3 id="badfiledesc"><title>I get the message 'Bad File Descriptor', why?</title>
1063 <sect3 id="proxy-chaining"><title>How do I chain <application>Privoxy</application> with other proxies
1064 (e.g. squid)?</title>
1071 <sect3 id="blocklist"><title>Do you still maintain the blocklists?</title>
1073 No. The format of the blocklists has changed significantly in the versions
1074 2.9.x. Once we have released the new stable version, v3.0, there will
1075 again be blocklists that you can update automatically.
1079 <sect3 id="newads"><title>How can I submit new ads?</title>
1081 As of now, please discontinue to submit new ad blocking infos. Once we
1082 have released the new version, there will again be a form on the website,
1083 which you can use to contribute new ads.
1087 <sect3 id="ip"><title>How can I hide my IP address?</title>
1089 You cannot hide your IP address with <application>Privoxy</application> or any other software, since
1090 the server needs to know your IP address to send the answer to you.
1093 Fortunately there are many publicly usable anonymous proxies out there, which
1094 solve the problem by providing a further level of indirection between you and
1095 the web server, shared by many people and thus letting your requests "drown"
1096 in white noise of unrelated requests as far as user tracking is concerned.
1099 Most of them will, however, log your IP address and make it available to the
1100 authorities in case you abuse that anonymity for criminal purposes. In fact
1101 you can't even rule out that some of them only exist to *collect* information
1102 on (those suspicious) people with a more than average preference for privacy.
1105 You can find a list of anonymous public proxies at <ulink
1106 url="http://www.multiproxy.org/anon_list.htm">multiproxy.org</ulink> and many
1107 more through Google.
1111 <!-- <sect3 id="image"><title>What is the imagefile (simage.ini, etc.) for?</title> -->
1113 <!-- Anytime <application>Privoxy</application> determines (with the help of the blocklist) that a URL -->
1114 <!-- contains an advertisement, it has to decide whether this advertisement is an -->
1115 <!-- image or not. <application>Privoxy</application> uses the imagefile for that purpose. -->
1120 <title id="anonforsure">Can <application>Privoxy</application> guarantee I am anonymous?</title>
1122 No. Your chances of remaining anonymous are greatly improved, but unless you
1123 are an expert on Internet security it would be safest to assume that
1124 everything you do on the Web can be traced back to you.
1127 <application>Privoxy</application> can remove various information about you,
1128 and allows <emphasis>you</emphasis> more freedom to decide which sites
1129 you can trust. But it's still possible that web sites can find out who you
1130 are. Here's one way this can happen.
1133 A few browsers disclose the user's email address in certain situations, such
1134 as when transferring a file by FTP. <application>Privoxy</application>
1135 does not filter FTP. If you need this feature, or are concerned about the
1136 mail handler of your browser disclosing your email address, you might
1137 consider products such as <application>NSClean</application>.
1140 Browsers available only as binaries could use non-standard headers to give
1141 out any information they can have access to: see the manufacturer's license
1142 agreement. It's impossible to anticipate and prevent every breach of privacy
1143 that might occur. The professionally paranoid prefer browsers available as
1144 source code, because anticipating their behavior is easier. Trust the source,
1151 <title id="sitebreak">Might some things break because header information is
1152 being altered?</title>
1155 Definitely. More and more sites use HTTP header content to decide what to
1156 display and how to display it. There is many ways that this can be handled,
1157 so having hard and fast rules, is tricky.
1161 <quote>USER AGENT</quote> in particular is often used in this way to identify
1162 the browser, and adjust content accordingly. Changing this now is not
1163 recommended, since so many sites do look for this. You may get undesirable
1164 results by changing this.
1168 For instance, different browsers use different encodings of Russian and Czech
1169 characters, certain web servers convert pages on-the-fly according to the
1170 User Agent header. Giving a <quote>User Agent</quote> with the wrong
1171 operating system or browser manufacturer causes some sites in these languages
1172 to be garbled; Surfers to Eastern European sites should change it to
1173 something closer. And then some page access counters work by looking at the
1174 <quote>REFERER</quote> header; they may fail or break if unavailable. The
1175 weather maps of Intellicast have been blocked by their server when no
1176 <quote>REFERER</quote> or cookie is provided, is another example. There are
1177 many, many other ways things can go wrong when trying to fool a web server.
1181 If you have problems with a site, you will have to adjust your configuration
1182 accordingly. Cookies are probably the most likely adjustment that may
1183 be required, but by no means the only one.
1191 <title id="caching">Can <application>Privoxy</application> act as a <quote>caching</quote> proxy to
1192 speed up web browsing?</title>
1194 No, it does not have this ability at all. You want something like
1195 <ulink url="http://www.squid-cache.org/">Squid</ulink> for this. And, yes,
1196 before you ask, <application>Privoxy</application> can co-exist
1197 with other kinds of proxies like <application>Squid</application>.
1202 <title id="firewall">What about as a firewall? Can <application>Privoxy</application> protect me?</title>
1204 Not in the way you mean, or in the way a true firewall can, or a proxy that
1205 has this specific capability. <application>Privoxy</application> can help
1206 protect your privacy, but not really protect you from intrusion attempts.
1212 <title id="logo">The <application>Privoxy</application> logo that replaces ads is very blocky
1213 and ugly looking. Can't a better font be used?</title>
1216 This is not a font problem. The logo is an image that is created by
1217 <application>Privoxy</application> on the fly. So as to not waste
1218 memory, the image is rather small. The blockiness comes when the
1219 image is scaled to fill a largish area. There is not much to be done
1220 about this, other than to use one of the other
1221 <quote>imageblock</quote> directives: <emphasis>pattern</emphasis>,
1222 <emphasis>blank</emphasis>, or a URL of your choosing.
1225 Given the above problem, we have decided to remove the logo option entirely
1232 <title id="wasted">I have large empty spaces now where ads used to be.
1235 It would be easy enough to just eliminate this space altogether, rather than
1236 fill it with blank space. But, this would create problems with many pages
1237 that use the overall size of the ad to help organize the page layout and
1238 position the various components of the page where they were intended to be.
1239 It is best left this way.
1245 <title id="ssl">How can <application>Privoxy</application> filter Secure (HTTPS) URLs?</title>
1247 This is a limitation since HTTPS transactions are encrypted SSL sessions
1248 between your browser and the secure site, and are meant to be reliably
1249 <emphasis>secure</emphasis> and private. This means that all cookies and HTTP
1250 header information are also encrypted from the time they leave your browser,
1251 to the site, and vice versa. <application>Privoxy</application> does not
1252 try to unencrypt this information, so it just passes through as is.
1253 <application>Privoxy</application> can still catch images and ads that
1254 are embedded in the SSL stream though.
1261 <title id="secure"><application>Privoxy</application> runs as a <quote>server</quote>. How
1262 secure is it? Do I need to take any special precautions?</title>
1264 There are no known exploits that might effect
1265 <application>Privoxy</application>. On Unix-like systems,
1266 <application>Privoxy</application> can run as a non-privileged
1267 user, which is how we recommend it be run. Also, by default
1268 <application>Privoxy</application> only listens to requests
1269 from <quote>localhost</quote>. The server aspect of
1270 <application>Privoxy</application> is not itself directly exposed to the
1271 Internet in this configuration. If you want to have
1272 <application>Privoxy</application> serve as a LAN proxy, this will have to
1273 be opened up to allow for LAN requests. In this case, we'd recommend
1274 you specify only the LAN gateway address, e.g. 192.168.1.1, in the main
1275 <application>Privoxy</application> config file. All LAN hosts can then use
1276 this as their proxy address in the browser proxy configuration. In this way,
1277 <application>Privoxy</application> will not listen on any external ports.
1278 Of course, a firewall is always good too. Better safe than sorry.
1283 <sect3 id="turnoff">
1284 <title>How can I temporarily disable <application>Privoxy</application>?</title>
1286 The easiest way is to access <application>Privoxy</application> with your
1287 browser by using the special URL: <ulink url="http://p.p/">http://p.p/</ulink>
1288 and select "Toggle Privoxy on or off" from that page.
1296 <!-- ~~~~~ New section ~~~~~ -->
1299 <title id="trouble">Troubleshooting</title>
1302 <title id="refused">I just upgraded and am getting <quote>connection refused</quote>
1303 with every web page?</title>
1305 Either <application>Privoxy</application> is not running, or your
1306 browser is configured for a different port than what
1307 <application>Privoxy</application> is using.
1311 The old <application>Privoxy</application> (and also
1312 <application>Junkbuster</application>) used port 8000 by
1313 default. This has been changed to port 8118 now, due to a conflict
1314 with NAS (Network Audio Service), which uses port 8000. If you haven't,
1315 you need to change your browser to the new port number, or alternately
1316 change <application>Privoxy's</application> <quote>listen-address</quote>
1317 setting in the <filename>config</filename> file used to start
1318 <application>Privoxy</application>.
1324 <title id="flushit">I just added a new rule, but the steenkin ad is
1325 still getting through. How?</title>
1327 If the ad had been displayed before you added its URL, it will probably be
1328 held in the browser's cache for some time, so it will be displayed without
1329 the need for any request to the server, and <application>Privoxy</application>
1330 will not be in the picture. The best thing to do is try flushing the browser's
1331 caches. And then try again.
1335 If this doesn't help, you probably have an error in the rule you
1336 applied. Try pasting the full URL of the offending ad into <ulink
1337 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
1338 and see if any actions match your new rule.
1344 <title id="badsite">One of my favorite sites does not work with <application>Privoxy</application>.
1345 What can I do?</title>
1348 First verify that it is indeed a <application>Privoxy</application> problem,
1349 by disabling <application>Privoxy</application> filtering and blocking.
1350 Go to <ulink url="http://p.p/">http://p.p/</ulink> and click on
1351 <quote>Toggle Privoxy On or Off</quote>, then disable it. Now try that
1352 page again. It's probably a good idea to flush the browser cache as well.
1356 If still a problem, go to <quote>Show which actions apply to a URL and
1357 why</quote> from <ulink url="http://p.p/">http://p.p/</ulink> and paste
1358 the full URL of the page in question into the prompt. See which actions are
1359 being applied to the URL. Now, armed with this information, go to <quote>Edit
1360 the actions list</quote>. Here you should see various sections that have
1361 various <application>Privoxy</application> features disabled for specific
1362 sites. Disabled <quote>actions</quote> will have a <quote>-</quote> (minus
1363 sign) in front of them. Add your problem page URL to one of these sections
1364 that looks like it is disabling the feature that is causing the
1365 problem. Re-try the page. There might be some trial and error involved. This
1366 is discussed in a little more detail in the
1367 <ulink url="../user-manual/appendix.html#ACTIONSANAT">user-manual
1373 Alternately, if you are comfortable with a text editor, you can accomplish
1374 the same thing by editing the appropriate <quote>actions</quote> file.
1380 <title>Where can I get help? Report bugs? Feature Requests? Etc?</title>
1382 Feedback is encouraged, whether good, bad or ugly. Please see the contact
1383 page in the <ulink url="../user-manual/contact.html">user-manual</ulink> for
1391 <title id="time">What time is it?</title>
1402 <!-- ~~~~~ New section ~~~~~ -->
1404 FIXME: Commented out until we have something to put here. HB 03/18/02.
1405 <sect1 id="knownissues"><title>Known Issues</title>
1412 <!-- ~~~~~ New section ~~~~~ -->
1415 This is referenced in the doc header already. HB 03/25/02
1417 <sect1 id="contact"><title>Contact the developers</title>
1418 <para>Please see the user manual for information on how to contact the developers.
1422 <!-- ~~~~~ New section ~~~~~ -->
1423 <sect1 id="copyright"><title>Copyright and History</title>
1426 <ulink url="../user-manual/copyright.html#HISTORY">user-manual</ulink> for
1427 information on Copyright and History.
1431 <!-- ~~~~~ New section ~~~~~ -->
1432 <sect1 id="seealso"><title>See also</title>
1435 <ulink url="../user-manual/seealso.html">user-manual</ulink> for
1442 Tue 09/11/01 06:38:14 PM EST: Test SGML doc by Hal Burgiss.
1444 Last modified: Mon Sep 10 19:22:09 CEST 2001
1446 This program is free software; you can redistribute it
1447 and/or modify it under the terms of the GNU General
1448 Public License as published by the Free Software
1449 Foundation; either version 2 of the License, or (at
1450 your option) any later version.
1452 This program is distributed in the hope that it will
1453 be useful, but WITHOUT ANY WARRANTY; without even the
1454 implied warranty of MERCHANTABILITY or FITNESS FOR A
1455 PARTICULAR PURPOSE. See the GNU General Public
1456 License for more details.
1458 The GNU General Public License should be included with
1459 this file. If not, you can view it at
1460 http://www.gnu.org/copyleft/gpl.html
1461 or write to the Free Software Foundation, Inc., 59
1462 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
1465 Revision 1.35 2002/03/30 04:14:19 hal9
1466 Fix privoxy.org/config links.
1468 Revision 1.34 2002/03/29 04:35:56 hal9
1471 Revision 1.33 2002/03/29 01:31:48 hal9
1472 Several new Q/A's and other touch ups.
1474 Revision 1.32 2002/03/27 00:57:03 hal9
1475 Touch ups for name change.
1477 Revision 1.31 2002/03/26 22:29:55 swa
1478 we have a new homepage!
1480 Revision 1.30 2002/03/25 16:39:22 hal9
1481 A few new sections. Made all links relative to user-manual.
1483 Revision 1.29 2002/03/25 05:23:57 hal9
1484 Moved section, and touch ups.
1486 Revision 1.28 2002/03/25 04:27:33 hal9
1487 New section related to name change.
1489 Revision 1.25 2002/03/24 16:08:08 swa
1490 we are too lazy to make a block-built
1491 privoxy logo. hence removed the option.
1493 Revision 1.24 2002/03/24 15:46:20 swa
1494 name change related issue.
1496 Revision 1.23 2002/03/24 12:33:01 swa
1499 Revision 1.22 2002/03/24 11:51:00 swa
1500 name change. changed filenames.
1502 Revision 1.21 2002/03/24 11:01:06 swa
1505 Revision 1.20 2002/03/23 15:13:11 swa
1506 renamed every reference to the old name with foobar.
1507 fixed "application foobar application" tag, fixed
1508 "the foobar" with "foobar". left junkbustser in cvs
1509 comments and remarks to history untouched.
1511 Revision 1.19 2002/03/21 17:01:54 hal9
1514 Revision 1.18 2002/03/18 16:40:31 hal9
1517 Revision 1.17 2002/03/18 03:53:53 hal9
1520 Revision 1.16 2002/03/17 21:32:56 hal9
1521 A few more additions.
1523 Revision 1.15 2002/03/17 07:25:59 hal9
1524 Correcting some of my typos, and some additions.
1526 Revision 1.14 2002/03/17 02:39:13 hal9
1527 A little more added ...
1529 Revision 1.13 2002/03/17 00:22:20 hal9
1530 Adding new stuff, and trying to incorporate stuff from old faq.
1532 Revision 1.12 2002/03/11 20:13:21 swa
1535 Revision 1.11 2002/03/11 18:42:27 swa
1538 Revision 1.10 2002/03/11 13:13:27 swa
1539 correct feedback channels
1541 Revision 1.9 2002/03/10 23:34:04 swa
1542 more info on not hiding ip address
1544 Revision 1.8 2002/03/09 15:55:48 swa
1545 added default config section
1547 Revision 1.7 2002/03/07 18:16:55 swa
1550 Revision 1.6 2002/03/07 13:16:31 oes
1551 Committing changes by Stefan
1553 Revision 1.5 2002/03/02 15:50:04 swa
1554 2.9.11 version. more input for docs.
1556 Revision 1.4 2002/02/24 14:34:24 jongfoster
1557 Formatting changes. Now changing the doctype to DocBook XML 4.1
1558 will work - no other changes are needed.
1560 Revision 1.3 2001/09/23 10:13:48 swa
1561 upload process established. run make webserver and
1562 the documentation is moved to the webserver. documents
1563 are now linked correctly.
1565 Revision 1.2 2001/09/13 15:20:17 swa
1566 merged standards into developer manual
1568 Revision 1.1 2001/09/12 15:36:41 swa
1569 source files for junkbuster documentation
1571 Revision 1.3 2001/09/10 17:43:59 swa
1572 first proposal of a structure.
1574 Revision 1.2 2001/06/13 14:28:31 swa
1575 docs should have an author.
1577 Revision 1.1 2001/06/13 14:20:37 swa
1578 first import of project's documentation for the webserver.