1 <!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook V3.1//EN"[
2 <!entity % dummy "IGNORE">
3 <!entity supported SYSTEM "supported.sgml">
4 <!entity newfeatures SYSTEM "newfeatures.sgml">
5 <!entity p-intro SYSTEM "privoxy.sgml">
6 <!entity seealso SYSTEM "seealso.sgml">
7 <!entity contacting SYSTEM "contacting.sgml">
8 <!entity history SYSTEM "history.sgml">
9 <!entity copyright SYSTEM "copyright.sgml">
10 <!entity license SYSTEM "license.sgml">
11 <!entity p-version "3.0.7">
12 <!entity p-status "UNRELEASED">
13 <!entity % p-not-stable "INCLUDE">
14 <!entity % p-stable "IGNORE">
15 <!entity % p-text "IGNORE"> <!-- define we are not a text only doc -->
16 <!entity % p-doc "INCLUDE"> <!-- and we are a formal doc -->
17 <!entity % p-supp-userman "INCLUDE"> <!-- Include all from supported.sgml -->
18 <!entity my-copy "©"> <!-- kludge for docbook2man -->
19 <!entity % p-newstuff "INCLUDE"> <!-- exclude stuff from devel versions -->
20 <!entity my-app "<application>Privoxy</application>">
23 File : $Source: /cvsroot/ijbswa/current/doc/source/faq.sgml,v $
26 This file belongs into
27 ijbswa.sourceforge.net:/home/groups/i/ij/ijbswa/htdocs/
29 $Id: faq.sgml,v 2.30 2007/11/04 15:16:40 hal9 Exp $
31 Copyright (C) 2001-2007 Privoxy Developers http://privoxy.org
34 Based partially on the Internet Junkbuster FAQ originally written by and
35 Copyright (C) 1997 Anonymous Coders and Junkbusters Corporation.
36 http://www.junkbusters.com/
38 <Qandaset defaultlabel='qanda'>
53 ========================================================================
54 NOTE: Please read developer-manual/documentation.html before touching
57 Please we keep the info in this file as version independent as possible
58 so we only have to maintain one FAQ. Where significant changes are
59 made to Privoxy configuration, please note the change in such a way that
60 it makes sense to both users of older and newer versions.
61 ========================================================================
67 <article id="index" class="faq">
69 <title>Privoxy Frequently Asked Questions</title>
73 <!-- Completely the wrong markup, but very little is allowed -->
74 <!-- in this part of an article. FIXME -->
75 <link linkend="copyright">Copyright</link> &my-copy; 2001-2007 by
76 <ulink url="http://www.privoxy.org/">Privoxy Developers</ulink>
80 <pubdate>$Id: faq.sgml,v 2.30 2007/11/04 15:16:40 hal9 Exp $</pubdate>
84 Note: this should generate a separate page, and a live link to it.
85 But it doesn't for some mysterious reason. Please leave commented
86 unless it can be fixed proper. For the time being, the copyright
87 statement will be in copyright.smgl.
91 <legalnotice id="legalnotice">
93 text goes here ........
103 <orgname>By: Privoxy Developers</orgname>
112 This is here to keep vim syntax file from breaking :/
113 If I knew enough to fix it, I would.
114 PLEASE DO NOT REMOVE! HB: hal@foobox.net
119 This FAQ gives quick answers to frequently asked questions about
120 <ulink url="http://www.privoxy.org/">Privoxy</ulink>.
121 It is not a substitute for the
122 <ulink url="../user-manual/index.html"><citetitle>Privoxy User Manual</citetitle></ulink>.
124 This works, at least in some situtations:
125 Test: <ulink url="privoxy-user-manual.pdf"><citetitle>User Manual</citetitle></ulink>.
129 <!-- Include privoxy.sgml boilerplate: -->
130 <para>What is Privoxy?</para> &p-intro;
131 <!-- end boilerplate -->
134 Please note that this document is a work in progress. This copy represents
135 the state at the release of version &p-version;.
136 You can find the latest version of the document at <ulink
137 url="http://www.privoxy.org/faq/">http://www.privoxy.org/faq/</ulink>.
138 Please see the <link linkend="contact">Contact section</link> if you want to
139 contact the developers.
143 <!-- Feel free to send a note to the developers at <email>ijbswa-developers@lists.sourceforge.net</email>. -->
149 <!-- ~~~~~ New section ~~~~~ -->
151 <sect1 id="general"><title>General Information</title>
152 <sect2 renderas="sect3" id="who-uses"><title>Who should use Privoxy?</title>
154 Anyone that is interested in security, privacy, or in
155 finer-grained control over their web and Internet experience.
156 Everyone is encouraged to try &my-app;.
160 <sect2 renderas="sect3" id="bestchoice"><title>Is Privoxy the best choice for
163 &my-app; is certainly a good choice, especially for those who want more
164 control and security. Those that have the ability to fine-tune their installation
165 will benefit the most. One of <application>Privoxy's</application>
166 strength's is that it is highly configurable giving you the ability to
167 completely personalize your installation. Being familiar with, or at least
168 having an interest in learning about <ulink
169 url="http://en.wikipedia.org/wiki/Http">HTTP</ulink> and other networking
170 protocols, <ulink url="http://en.wikipedia.org/wiki/Html">HTML</ulink>,
171 <ulink url="http://en.wikipedia.org/wiki/Internet_Protocol">IP (Internet
172 Protocol)</ulink>, and
173 <ulink url="http://en.wikipedia.org/wiki/Regular_expressions"><quote>Regular
174 Expressions</quote></ulink>
175 will be a big plus and will help you get the most out of &my-app;.
176 A new installation just includes a very basic configuration. The user
177 should take this as a starting point only, and enhance it as he or she
178 sees fit. In fact, the user is encouraged, and expected to, fine-tune the
182 Much of <application>Privoxy's</application> configuration can be done
183 with a <ulink url="http://en.wikipedia.org/wiki/Web_browser">Web browser</ulink>.
184 But there are areas where configuration is done using a
185 <ulink url="http://en.wikipedia.org/wiki/Text_editors">text editor</ulink>
186 to edit configuration files.
190 <sect2 renderas="sect3" id="proxymoron"><title>What is a <quote>proxy</quote>? How does
191 Privoxy work? </title>
193 A <ulink url="http://en.wikipedia.org/wiki/Proxy_server">web proxy</ulink>
194 is a service, based on a software such as
195 <application>Privoxy</application>, that clients (i.e. browsers) can use
196 instead of connecting directly to web servers on the Internet. The
197 clients then ask the proxy to fetch the objects they need (web pages,
198 images, movies etc) on their behalf, and when the proxy has done so, it
199 hands the results back to the client. It is a <quote>go-between</quote>. See
200 the <ulink url="http://en.wikipedia.org/wiki/Proxy_server">Wikipedia proxy
201 definition</ulink> for more.
204 There are many reasons to use web proxies, such as security (firewalling),
205 efficiency (caching) and others, and there are any number of proxies
206 to accommodate those needs.
209 <application>Privoxy</application> is a proxy that is primarily focused on privacy
210 protection, ad and junk elimination and freeing the user from restrictions placed on his
211 activities. Sitting between your browser(s) and the Internet,
212 it is in a perfect position to filter outbound personal information that your
213 browser is leaking, as well as inbound junk. It uses a variety of techniques to do
214 this, all of which are under your complete control via the various configuration
215 files and options. Being a proxy also makes it easier to share
216 configurations among multiple browsers and/or users.
220 <sect2 renderas="sect3" id="otherstuff">
221 <title>Does Privoxy do anything more than ad blocking?</title>
223 Yes, ad blocking is but one possible use. There are many, many ways &my-app;
224 can be used to sanitize and customize web browsing.
228 <sect2 renderas="sect3" id="newjb"><title>What is this new version of
229 <quote><citetitle>Junkbuster</citetitle></quote>?</title>
231 <!-- Include history.sgml -->
238 <sect2 renderas="sect3">
239 <title id="whyprivoxy">Why <quote>Privoxy</quote>? Why change the name from
240 Junkbuster at all?</title>
242 Though outdated, <ulink url="http://junkbusters.com/">Junkbusters Corporation</ulink>
243 continues to offer their original version of the <application>Internet
244 Junkbuster</application>, so publishing our
245 <application> Junkbuster</application>-derived software under the same name
249 There are also potential legal complications from our use of the
250 <application>Junkbuster</application> name, which is a registered trademark of
251 <ulink url="http://junkbusters.com/">Junkbusters Corporation</ulink>.
252 There are, however, no objections from Junkbusters Corporation to the
253 <application>Privoxy</application> project itself, and they, in fact, still
254 share our ideals and goals.
257 The developers also believed that there are so many improvements over the original
258 code, that it was time to make a clean break from the past and make
259 a name in their own right.
262 <application>Privoxy</application> is the
263 <quote><emphasis>Privacy Enhancing Proxy</emphasis></quote>. Also, its content
264 modification and junk suppression gives <emphasis>you</emphasis>, the user, more
265 control, more freedom, and allows you to browse your personal and
266 <quote><emphasis>private</emphasis> edition</quote> of the web.
270 <sect2 renderas="sect3" id="differs"><title>How does Privoxy differ
271 from the old Junkbuster?</title>
273 <application>Privoxy</application> picks up where
274 <application>Junkbuster</application> left off. All the old features remain.
275 The new <application>Privoxy</application> still blocks ads and banners,
277 url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>, and still
278 helps protect your privacy. But, these are all greatly enhanced, and many,
279 many new features have been added, all in the same vein.
282 The configuration has changed significantly as well. This is something that
283 users will notice right off the bat if upgrading from
284 <application>Junkbuster</application> 2.0.x. The <quote>blocklist</quote>
285 <quote>cookielist</quote>, <quote>imagelist</quote> and much more has been
286 combined into the <quote>actions</quote> files, with a completely different
287 syntax. <![%p-newstuff;[ See the <ulink url="../user-manual/whatsnew.html">What's New</ulink>
288 page for the latest updates.]]>
291 <application>Privoxy</application>'s new features include:
294 <!-- Include newfeatures.sgml: -->
300 <sect2 renderas="sect3" id="whatsanad">
301 <title id="knows">How does Privoxy know what is
302 an ad, and what is not?</title>
304 <application>Privoxy</application>'s approach to blocking ads is twofold:
307 First, there are certain patterns in the <emphasis>locations</emphasis> (URLs)
308 of banner images. This applies to both the path (you wouldn't guess how many
309 web sites serve their banners from a directory called <quote>banners</quote>!)
310 and the host (blocking the big banner hosting services like doublecklick.net
311 already helps a lot). <application>Privoxy</application> takes advantage of this
312 fact by using <ulink url="../user-manual/actions-file.html#AF-PATTERNS">URL
313 patterns</ulink> to sort out and block the requests for things that sound
314 like they would be ads or banners.
317 Second, banners tend to come in certain <emphasis>sizes</emphasis>. But you
318 can't tell the size of an image by its URL without downloading it, and if you
319 do, it's too late to save bandwidth. Therefore, <application>Privoxy</application>
320 also inspects the HTML sources of web pages while they are loaded, and replaces
321 references to images with standard banner sizes by dummy references, so that
322 your browser doesn't request them anymore in the first place.
325 Both of this involves a certain amount of guesswork and is, of course, freely
326 and readily configurable.
330 <sect2 renderas="sect3">
331 <title id="mistakes">Can Privoxy make mistakes?
332 This does not sound very scientific.</title>
334 Actually, it's a black art ;-) And yes, it is always possible to have a broad
335 rule accidentally block or change something by mistake. You will almost surely
336 run into such situations at some point. It is tricky writing rules to
337 cover every conceivable possibility, and not occasionally get false positives.
341 But this should not be a big concern since the
342 <application>Privoxy</application> configuration is very flexible, and
343 includes tools to help identify these types of situations so they can be
344 addressed as needed, allowing you to customize your installation.
345 (<link linkend="badsite">See the Troubleshooting section below</link>.)
350 <sect2 renderas="sect3">
351 <title id="configornot">Will I have to configure Privoxy
352 before I can use it?</title>
354 No, not really. The default installation should give you a good starting
355 point, and block <emphasis>most</emphasis> ads and unwanted content. Many of
356 the more advanced features are off by default, and would require you to
360 You do have to set up your browser to use
361 <application>Privoxy</application> (see the <link
362 linkend="firststep">Installation section below</link>).
365 And you will certainly run into situations where there are false positives,
366 or ads not being blocked that you may not want to see. In these cases, you
367 would certainly benefit by customizing <application>Privoxy's</application>
368 configuration to more closely match your individual situation. And we would
369 encourage you to do this. This is where the real power of
370 <application>Privoxy</application> lies!
375 <sect2 renderas="sect3" id="lan">
376 <title>Can Privoxy run as a server on a network?</title>
378 Yes, &my-app; runs as a server already, and can easily be configured to
379 <quote>serve</quote> more than one client. See <link linkend="lanconfig">
380 How can I set up Privoxy to act as a proxy for my LAN</link> below.
384 <sect2 renderas="sect3" id="browsers2"><title>My browser does the same things as
385 Privoxy. Why should I use Privoxy at all?</title>
387 Modern browsers do indeed have <emphasis>some</emphasis> of the same
388 functionality as <application>Privoxy</application>. Maybe this is
389 adequate for you. But <application>Privoxy</application> is much more
390 versatile and powerful, and can do a number of things that browsers just can't.
393 In addition, a proxy is good choice if you use multiple browsers, or
394 have a LAN with multiple computers since &my-app; can run as a server
395 application. This way all the configuration is in one place, and you don't
396 have to maintain a similar configuration for possibly many browsers or
401 <sect2 renderas="sect3" id="whytrust"><title>Why should I trust Privoxy?</title>
403 The most important reason is because you have access to
404 <emphasis>everything</emphasis>, and you can control everything. You can
405 check every line of every configuration file yourself. You can check every
406 last bit of source code should you desire. And even if you can't read code,
407 there should be some comfort in knowing that thousands of other people can,
408 and some of them do read it. You can build the software from scratch, if you want,
409 so that you know the executable is clean, and that it is
410 <emphasis>yours</emphasis>. In fact, we encourage this level of scrutiny. It
411 is one reason we use &my-app; ourselves.
415 <sect2 renderas="sect3" id="license"><title>Is there is a license or fee? What about a
416 warranty? Registration?</title>
418 <application>Privoxy</application> is licensed under the <ulink
419 url="http://www.gnu.org/licenses/old-licenses/gpl-2.0.html">GNU General Public License (GPL) version 2</ulink>.
420 It is free to use, copy, modify or distribute as you wish under the terms of this
421 license. Please see the <link linkend="copyright">Copyright</link> section for more
422 information on the license and copyright. Or the <filename>LICENSE</filename> file
423 that should be included.
426 There is <emphasis>no warranty</emphasis> of any kind, expressed, implied or otherwise.
427 That is something that would cost real money ;-) There is no registration either.
428 <application>Privoxy</application> really is <emphasis>free</emphasis>
434 <sect2 renderas="sect3" id="spyware">
435 <title>Can Privoxy remove spyware? Adware? Viruses?</title>
437 No, at least not reliable enough to trust it. &my-app; is not designed to be
438 a malware removal tool and the default configuration doesn't even try to
439 filter out any malware.
442 &my-app; could help prevent contact from (known) sites that use such
443 tactics with appropriate configuration rules, and thus could conceivably
444 prevent contamination from such sites.
449 <sect2 renderas="sect3" id="otherads">
450 <title>Can I use Privoxy with other ad-blocking software?</title>
452 &my-app; should work fine with other proxies and other software in general.
455 But it is probably not necessary to use &my-app; in conjunction with other
456 ad-blocking products, and this could conceivably cause undesirable results.
457 It would be better to choose one software or the other and work a little to
458 tweak its configuration to your liking.
462 <sect2 renderas="sect3" id="jointeam"><title>I would like to help you, what can I do?</title>
464 <sect3 renderas="sect4" id="jointeam-work"><title>Would you like to participate?</title>
466 Well, we <emphasis>always</emphasis> need help. There is something for
467 everybody who wants to help us. We welcome new developers, packagers,
468 testers, documentation writers or really anyone with a desire to help in
469 any way. You <emphasis>DO NOT</emphasis> need to be a
470 <quote>programmer</quote>. There are many other tasks available. In fact,
471 the programmers often can't spend as much time programming because of some
472 of the other, more mundane things that need to be done, like checking the
473 Tracker feedback sections.
476 So first thing, <ulink
477 url="https://sourceforge.net/account/register.php">get an account on SourceForge.net</ulink>
478 and mail your id to the <ulink url="mailto:ijbswa-developers@lists.sourceforge.net">developers
479 mailing list</ulink>. Then, please read the <ulink
480 url="../developer-manual/index.html">Developer's Manual</ulink>, at least
481 the pertinent sections.
485 <sect3 renderas="sect4" id="jointeam-money"><title>Contribute!</title>
487 We, of course, welcome donations and could use money for domain registering,
488 buying software to test <application>Privoxy</application> with, and, of course,
489 for regular world-wide get-togethers (hahaha). If you enjoy the software and feel
490 like helping us with a donation, just <ulink
491 url="mailto: ijbswa-developers@lists.sourceforge.net">drop us a note</ulink>.
495 <sect3 renderas="sect4" id="jointeam-software"><title>Software</title>
497 If you are a vendor of a web-related software like a browser, web server
498 or proxy, and would like us to ensure that <application>Privoxy</application>
499 runs smoothly with your product, you might consider supplying us with a
500 copy or license. We can't, however, guarantee that we will fix all potential
501 compatibility issues as a result.
511 <!-- ~~~~~ New section ~~~~~ -->
513 <sect1 id="installation"><title>Installation</title>
515 <sect2 renderas="sect3" id="whichbrowsers">
516 <title>Which browsers are supported by Privoxy?</title>
518 Any browser that can be configured to use a proxy, which
519 should be virtually all browsers, including
520 <application>Firefox</application>, <application>Internet
521 Explorer</application>, <application>Opera</application>, and
522 <application>Safari</application> among others.
523 Direct browser support is not an absolute requirement since
524 <application>Privoxy</application> runs as a separate application and talks
525 to the browser in the standardized HTTP protocol, just like a web server
530 <sect2 renderas="sect3" id="whichos">
531 <title>Which operating systems are supported?</title>
533 Include supported.sgml here:
538 <sect2 renderas="sect3" id="email-client">
539 <title>Can I use Privoxy with my email client?</title>
541 As long as there is some way to set a HTTP proxy for the client, then yes,
542 any application can be used, whether it is strictly speaking a
543 <quote>browser</quote> or not. Though this may not be the best approach for
544 dealing with some of the common abuses of HTML in email. See <link
545 linkend="outlook">How can I configure <application>Privoxy</application>
546 with <application>Outlook Express</application>?</link> below for more on
550 Be aware that HTML email presents a number of unique security and privacy
551 related issues, that can require advanced skills to overcome. The developers
552 recommend using email clients that can be configured to convert HTML to plain
553 text for these reasons.
557 <!-- Nobody is going to still be doing this!
558 <sect2 renderas="sect3" id="newinstall"><title>Can I install
559 Privoxy over Junkbuster?</title>
561 We recommend you un-install <application>Junkbuster</application>
562 first to minimize conflicts and confusion. You may want to
563 save your old configuration files for future reference. The configuration
564 files and syntax have substantially changed, so you will need to manually
565 port your old patterns. See the <ulink url="../user-manual/upgradersnote.html">note
566 to upgraders</ulink> and <ulink url="../user-manual/installation.html">installation
567 chapter</ulink> in the <ulink url="../user-manual/index.html">User Manual</ulink>
571 Note: Some installers may automatically un-install
572 <application>Junkbuster</application>, if present!
578 <sect2 renderas="sect3" id="firststep">
579 <title>I just installed Privoxy. Is there anything
580 special I have to do now?</title>
583 All browsers must be told to use <application>Privoxy</application>
584 as a proxy by specifying the correct proxy address and port number
585 in the appropriate configuration area for the browser. See
586 <ulink url="../user-manual/startup.html">the User Manual for more
587 details</ulink>. You should also flush your browser's memory and disk cache to get rid of any
588 cached junk items, and remove any stored
589 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>.
595 <sect2 renderas="sect3" id="localhost"><title>What is the proxy address of Privoxy?</title>
597 If you set up the <application>Privoxy</application> to run on
598 the computer you browse from (rather than your ISP's server or some
599 networked computer on a LAN), the proxy will be on <literal>127.0.0.1</literal>
600 (sometimes referred to as <quote>localhost</quote>,
601 which is the special name used by every computer on the Internet to refer
602 to itself) and the port will be 8118 (unless you have <application>Privoxy</application>
603 to run on a different port with the <ulink
604 url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink> config option).
607 When configuring your browser's proxy settings you typically enter
608 the word <quote>localhost</quote> or the IP address <quote>127.0.0.1</quote>
609 in the boxes next to <quote>HTTP</quote> and <quote>Secure</quote> (HTTPS) and
610 then the number <quote>8118</quote> for <quote>port</quote>.
611 This tells your browser to send all web requests to <application>Privoxy</application>
612 instead of directly to the Internet.
615 <application>Privoxy</application> can also be used to proxy for
616 a Local Area Network. In this case, your would enter either the IP
617 address of the LAN host where <application>Privoxy</application>
618 is running, or the equivalent hostname, e.g. <literal>192.168.1.1</literal>.
619 Port assignment would be same as above. Note that
620 <application>Privoxy</application> doesn't listen on any LAN interfaces by
624 <application>Privoxy</application> does not currently handle
625 any other protocols such as FTP, SMTP, IM, IRC, ICQ, etc. Be sure that
626 proxying any of these other protocols is not activated.
630 <sect2 renderas="sect3" id="nothing">
631 <title>I just installed Privoxy, and nothing is happening.
632 All the ads are there. What's wrong?</title>
635 Did you configure your browser to use <application>Privoxy</application>
636 as a proxy? It does not sound like it. See above. You might also try flushing
637 the browser's caches to force a full re-reading of pages. You can verify
638 that <application>Privoxy</application> is running, and your browser
639 is correctly configured by entering the special URL:
640 <ulink url="http://p.p/">http://p.p/</ulink>.
641 <!-- Use http://p.p/ instead of http://config.privoxy.org/ here because
642 of potential redirect caching problem (see next Q). -->
643 This should take you to a page titled <quote>This is Privoxy..</quote> with
644 access to <application>Privoxy's</application> internal configuration.
645 If you see this, then you are good to go. If you receive a page saying
646 <quote>Privoxy is not running</quote>, then the browser is not set up to use
647 your <application>Privoxy</application> installation.
648 If you receive anything else (probably nothing at all), it could either
649 be that the browser is not set up correctly, or that
650 <application>Privoxy</application> is not running at all. Check the <ulink
651 url="../user-manual/config.html#LOGFILE">log file</ulink>. For instructions
652 on starting <application>Privoxy</application> and browser configuration,
653 see the <ulink url="http://www.privoxy.org/user-manual/startup.html">chapter
654 on starting <application>Privoxy</application></ulink> in the
655 <ulink url="http://www.privoxy.org/user-manual/">User Manual</ulink>.
660 <sect2 renderas="sect3" id="notused">
661 <title>I get a <quote>Privoxy is not being used</quote> dummy page although
662 Privoxy is running and being used.</title>
665 First, make sure that Privoxy is <emphasis>really</emphasis> running and
666 being used by visiting <ulink url="http://p.p/">http://p.p/</ulink>. You
667 should see the <application>Privoxy</application> main page. If not, see
668 the <ulink url="http://www.privoxy.org/user-manual/startup.html">chapter
669 on starting <application>Privoxy</application></ulink> in the
670 <ulink url="http://www.privoxy.org/user-manual/">User Manual</ulink>.
674 Now if <ulink url="http://p.p/">http://p.p/</ulink> works for you, but
675 other parts of <application>Privoxy</application>'s web interface show
676 the dummy page, your browser has cached a redirection it encountered before
677 <application>Privoxy</application> was being used. You need to clear your
678 browser's cache. Note that shift-reloading the dummy page won't help, since
679 that'll only refresh the dummy page, not the redirection that lead you there.
683 The procedure for clearing the cache varies from browser to browser. For
684 example, <application>Mozilla/Netscape</application> users would click
685 <guibutton>Edit</guibutton> --> <guibutton>Preferences</guibutton> -->
686 <guibutton>Advanced</guibutton> --> <guibutton>Cache</guibutton> and
687 then click both <quote><guibutton>Clear Memory Cache</guibutton></quote>
688 and <quote><guibutton>Clear Disk Cache</guibutton></quote>.
689 And, <application>Firefox</application> users would click
690 <guibutton>Tools</guibutton> --> <guibutton>Options</guibutton> -->
691 <guibutton>Privacy</guibutton> --> <guibutton>Cache</guibutton> and
692 then click <quote><guibutton>Clear Cache Now</guibutton></quote>.
700 <!-- ~~~~~ New section ~~~~~ -->
702 <sect1 id="configuration"><title>Configuration</title>
703 <sect2 renderas="sect3">
704 <title id="actionsfile">What exactly is an <quote>actions</quote> file?</title>
707 &my-app; utilizes the concept of <quote>
708 <ulink url="../user-manual/actions-file.html#ACTIONS">actions</ulink></quote>
709 that are used to manipulate and control web page data.
710 <ulink url="../user-manual/actions-file.html">Actions files</ulink>
711 are where these <ulink url="../user-manual/actions-file.html#ACTIONS">actions</ulink>
712 that <application>Privoxy</application> could take while processing a certain
713 request, are configured. Typically, you would define a set of default actions
714 that apply globally to all URLs, then add exceptions to these defaults where needed.
715 There is a wide array of actions available that give the user a high degree
716 of control and flexibility on how to process each and every web page.
720 Actions can be defined on a <ulink
721 url="../user-manual/actions-file.html#AF-PATTERNS">URL pattern</ulink> basis, i.e.
722 for single URLs, whole web sites, groups or parts thereof etc. Actions can also be
723 grouped together and then applied to requests matching one or more patterns.
724 There are many possible actions that might apply to any given site. As an example,
725 if you are blocking <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>
726 as one of your default actions, but need to accept cookies from a given site,
727 you would need to define an exception for this site in one of your actions
728 files, preferably in <filename>user.action</filename>.
733 <sect2 renderas="sect3" id="actionss">
734 <title>The <quote>actions</quote> concept confuses me. Please list
735 some of these <quote>actions</quote>.</title>
737 For a comprehensive discussion of the actions concept, please refer
738 to the <ulink url="../user-manual/actions-file.html">actions file
739 chapter</ulink> in the <ulink url="../user-manual/index.html">User
740 Manual</ulink>. It includes a <ulink
741 url="../user-manual/actions-file.html#ACTIONS">list of all actions</ulink>
742 and an <ulink url="../user-manual/actions-file.html#ACT-EXAMPLES">actions
743 file tutorial</ulink> to get you started.
748 <sect2 renderas="sect3">
749 <title id="actconfig">How are actions files configured? What is the easiest
750 way to do this?</title>
753 Actions files are just text files in a special syntax and can be edited
754 with a text editor. But probably the easiest way is to access
755 <application>Privoxy</application>'s user interface with your web browser
756 at <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
757 (Shortcut: <ulink url="http://p.p/">http://p.p/</ulink>) and then select
758 <quote><ulink url="http://config.privoxy.org/show-status">View &
759 change the current configuration</ulink></quote> from the menu. Note
760 that this feature must be explicitly enabled in the main config file
762 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>).
767 <sect2 renderas="sect3">
768 <title>There are several different <quote>actions</quote> files. What are
769 the differences?</title>
772 are being included by the developers, to be used for
773 different purposes: These are
774 <filename>default.action</filename>, the <quote>main</quote> actions file
775 which is actively maintained by the <application>Privoxy</application>
776 developers and typically sets the default policies, <filename>user.action</filename>, where users are encouraged
777 to make their private customizations, and <filename>standard.action</filename>,
778 which is for internal <application>Privoxy</application> use only.
779 Please see <ulink url="../user-manual/actions-file.html">the actions chapter</ulink>
780 in the <ulink url="../user-manual/index.html">User Manual</ulink> for a more
781 detailed explanation.
785 Earlier versions included three different versions of the
786 <filename>default.action</filename> file. The new scheme allows for
787 greater flexibility of local configuration, and for browser based
788 selection of pre-defined <quote>aggressiveness</quote> levels.
793 <sect2 renderas="sect3" id="getupdates"><title>Where can I get updated Actions Files?</title>
795 Based on your feedback and the continuing development, updates of
796 <filename>default.action</filename> will be
797 made available from time to time on the <ulink
798 url="http://sourceforge.net/project/showfiles.php?group_id=11118">files section</ulink> of
799 our <ulink url="http://sf.net/projects/ijbswa/">project page</ulink>.
803 If you wish to receive an email notification whenever we release updates of
804 <application>Privoxy</application> or the actions file, <ulink
805 url="http://lists.sourceforge.net/lists/listinfo/ijbswa-announce/">subscribe
806 to our announce mailing list</ulink>, ijbswa-announce@lists.sourceforge.net.
811 <sect2 renderas="sect3" id="newconfig"><title>Can I use my old config files?</title>
813 The syntax and purpose of configuration files has remained roughly the
814 same throughout the 3.x series, but backwards compatibility is not guaranteed.
815 Also each release contains updated, <quote>improved</quote> versions and it is
816 therefore strongly recommended to use the newer configuration files.
820 <sect2 renderas="sect3" id="difficult">
821 <title>Why is the configuration so complicated?</title>
823 <quote>Complicated</quote> is in the eye of the beholder. Those that are
824 familiar with some of the underlying concepts, such as regular expression
825 syntax, take to it like a fish takes to water. Also, software that tries
826 hard to be <quote>user friendly</quote>, often lacks sophistication and
827 flexibility. There is always that trade-off there between power vs.
828 easy-of-use. Furthermore, anyone is welcome to contribute ideas and
829 implementations to enhance &my-app;.
833 <sect2 renderas="sect3" id="yahoo"><title>How can I make my Yahoo/Hotmail/Gmail account work?</title>
835 The default configuration shouldn't impact the usability of any of these services.
836 It may, however, make all <ulink
837 url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>
838 temporary, so that your browser will forget your
839 login credentials in between browser sessions. If you would like not to have to log
840 in manually each time you access those websites, simply turn off all cookie handling
841 for them in the <filename>user.action</filename> file. An example for yahoo might
845 <screen># Allow all cookies for Yahoo login:
847 { -<ulink url="../user-manual/actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</ulink> -<ulink url="../user-manual/actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</ulink> -<ulink url="../user-manual/actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</ulink> }
848 .login.yahoo.com</screen>
851 These kinds of sites are often quite complex and heavy with
852 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink> and
853 thus <quote>fragile</quote>. So if <emphasis>still</emphasis> a problem,
855 url="../user-manual/actions-file.html#ALIASES">alias</ulink> just for such
859 <screen># Gmail is a _fragile_ site:
861 { <literal>fragile</literal> }
863 mail.google.com</screen>
866 Be sure to flush your browser's caches whenever making these kinds of
867 changes, just to make sure the changes <quote>take</quote>.
870 Make sure the domain, host and path are appropriate as well. Your browser can
871 tell you where you are specifically and you should use that information for
872 your configuration settings. Note that above it is not referenced as
873 <literal>gmail.com</literal>, which is a valid domain name.
878 <sect2 renderas="sect3" id="configfiles"> <title>What's the difference between the
879 <quote>Cautious</quote>, <quote>Medium</quote> and <quote>Advanced</quote> defaults?</title>
881 Configuring <application>Privoxy</application> is not entirely trivial. To
882 help you get started, we provide you with three different default action
883 <quote>profiles</quote> in the web based actions file editor at <ulink
884 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>.
885 See the <ulink url="../user-manual/actions-file.html"><citetitle>User
886 Manual</citetitle></ulink> for a list of actions, and how the default
891 Where the defaults are likely to break some sites, exceptions for
892 known popular <quote>problem</quote> sites are included, but in
893 general, the more aggressive your default settings are, the more exceptions
894 you will have to make later. New users are best to start off in
895 <quote>Cautious</quote> setting. This is safest and will have the fewest
896 problems. See the <ulink
897 url="../user-manual/index.html"><citetitle>User Manual</citetitle></ulink>
898 for a more detailed discussion.
902 It should be noted that the <quote>Advanced</quote> profile (formerly known
903 as the <quote>Adventuresome</quote> profile) is more
904 aggressive, and will make use of some of
905 <application>Privoxy's</application> advanced features. Use at your own risk!
910 <sect2 renderas="sect3" id="browseconfig"> <title>Why can I change the configuration
911 with a browser? Does that not raise security issues?</title>
913 It may seem strange that regular users can edit the config files with their
914 browsers, although the whole <filename>/etc/privoxy</filename> hierarchy
915 belongs to the user <quote>privoxy</quote>, with only 644 permissions.
918 When you use the browser-based editor, <application>Privoxy</application>
919 itself is writing to the config files. Because
920 <application>Privoxy</application> is running as the user <quote>privoxy</quote>,
921 it can update its own config files.
924 If you run <application>Privoxy</application> for multiple untrusted users (e.g. in
925 a LAN), you will probably want to make sure that the the web-based
926 editor and remote toggle features are <quote>off</quote> by setting <quote><literal><ulink
927 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>
928 0</literal></quote> and <quote><literal><ulink
929 url="../user-manual/config.html#ENABLE-REMOTE-TOGGLE">enable-remote-toggle</ulink>
930 0</literal></quote> in the <ulink url="../user-manual/config.html">main configuration file</ulink>.
933 Note that in the default configuration, only local users (i.e. those on
934 <quote>localhost</quote>) can connect to <application>Privoxy</application>,
935 so this is (normally) not a security problem.
940 <sect2 renderas="sect3">
941 <title id="filterfile">What is the <filename>default.filter</filename> file? What is a <quote>filter</quote>?</title>
943 The <ulink url="../user-manual/filter-file.html"><filename>default.filter</filename></ulink>
944 file is where <emphasis>filters</emphasis> as supplied by the developers are defined.
945 Filters are a special subset of actions that can be used to modify or
946 remove, web page content on the fly. Filters apply to <emphasis>anything</emphasis>
947 in the page source (and optionally both client and server headers), including
948 HTML tags, and JavaScript. Regular expressions are used to accomplish this.
949 There are a number of pre-defined filters to deal with common annoyances. The
950 filters are only defined here, to invoke them, you need to use the
952 url="../user-manual/actions-file.html#FILTER"><literal>filter</literal>
953 action</ulink> in one of the actions files. Filtering is automatically
954 disabled for inappropriate MIME types.
958 If you are familiar with regular expressions, and HTML, you can look at
959 the provided <filename>default.filter</filename> with a text editor and define
960 your own filters. This is potentially a very powerful feature, but
961 requires some expertise in both regular expressions and HTML/HTTP.
962 <![%p-newstuff;[ You should
963 place any modifications to the default filters, or any new ones you create
964 in a separate file, such as <filename>user.filter</filename>, so they won't
965 be overwritten during upgrades.
966 The ability to define multiple filter files
967 in <filename>config</filename> is a new feature as of v. 3.0.5.]]>
971 There is no GUI editor option for this part of the configuration,
972 but you can disable/enable the various pre-defined filters of the included
973 <filename>default.filter</filename> file with the <ulink
974 url="http://config.privoxy.org/show-status">web-based actions file editor</ulink>
976 that the custom actions editor must be explicitly enabled in the main config file
978 url="../user-manual/config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</ulink>).
984 <sect2 renderas="sect3" id="lanconfig">
985 <title>How can I set up Privoxy to act as a proxy for my
988 By default, <application>Privoxy</application> only responds to requests
989 from <literal>127.0.0.1</literal> (localhost). To have it act as a server for
990 a network, this needs to be changed in the <ulink
991 url="../user-manual/config.html">main configuration file</ulink>. Look for
993 url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink></literal>
994 option, which may be commented out with a <quote>#</quote> symbol. Make sure
995 it is uncommented, and assign it the address of the LAN gateway interface,
996 and port number to use. Assuming your LAN address is 192.168.1.1 and you
997 wish to run <application>Privoxy</application> on port 8118, this line
1003 listen-address 192.168.1.1:8118</screen>
1007 Save the file, and restart <application>Privoxy</application>. Configure
1008 all browsers on the network then to use this address and port number.
1012 Alternately, you can have <application>Privoxy</application> listen on
1013 all available interfaces:
1018 listen-address :8118</screen>
1022 And then use <application>Privoxy's</application>
1024 url="../user-manual/config.html#PERMIT-ACCESS">permit-access</ulink>
1025 feature to limit connections. A firewall in this situation is recommended
1030 The above steps should be the same for any TCP network, regardless of
1035 If you run <application>Privoxy</application> on a LAN with untrusted users,
1036 we recommend that you double-check the <ulink
1037 url="../user-manual/config.html#ACCESS-CONTROL">access control and security</ulink>
1044 <sect2 renderas="sect3">
1045 <title id="noseeum">Instead of ads, now I get a checkerboard pattern. I don't want to see anything.</title>
1047 The replacement for blocked images can be controlled with the <ulink
1048 url="../user-manual/actions-file.html#SET-IMAGE-BLOCKER"><literal>set-image-blocker</literal>
1049 action</ulink>. You have the choice of a checkerboard pattern, a transparent 1x1 GIF
1050 image (aka <quote>blank</quote>), or a redirect to a custom image of your choice.
1051 Note that this choice only has effect for images which are blocked as images, i.e.
1052 whose URLs match both a <literal><ulink
1053 url="../user-manual/actions-file.html#HANDLE-AS-IMAGE">handle-as-image</ulink></literal>
1054 <emphasis>and</emphasis> <literal><ulink
1055 url="../user-manual/actions-file.html#BLOCK">block</ulink></literal> action.
1058 If you want to see nothing, then change the <ulink
1059 url="../user-manual/actions-file.html#SET-IMAGE-BLOCKER"><literal>set-image-blocker</literal>
1060 action</ulink> to <quote>blank</quote>. This can be done by editing the
1061 <filename>user.action</filename> file, or through the <ulink
1062 url="http://config.privoxy.org/show-status">web-based actions file editor</ulink>.
1067 <sect2 renderas="sect3">
1068 <title id="whyseeum">Why would anybody want to see a checkerboard pattern?</title>
1070 Remember that <link linkend="whatsanad">telling which image is an ad and which
1071 isn't</link>, is an educated guess. While we hope that the standard configuration
1072 is rather smart, it will make occasional mistakes. The checkerboard image is visually
1073 decent, and it shows you where images have been blocked, which can be very
1074 helpful in case some navigation aid or otherwise innocent image was
1075 erroneously blocked. It is recommended for new users so they can
1076 <quote>see</quote> what is happening. Some people might also enjoy seeing how
1077 many banners they <emphasis>don't</emphasis> have to see.
1082 <sect2 renderas="sect3">
1083 <title id="blockedbytext">I see some images being replaced with text
1084 instead of the checkerboard image. Why and how do I get rid of this?</title>
1086 This happens when the banners are not embedded in the HTML code of the
1087 page itself, but in separate HTML (sub)documents that are loaded into (i)frames
1088 or (i)layers, and these external HTML documents are blocked. Being non-images
1089 they get replaced by a substitute HTML page rather than a substitute image,
1090 which wouldn't work out technically, since the browser expects and accepts
1091 only HTML when it has requested an HTML document.
1094 The substitute page adapts to the available space and shows itself as a
1095 miniature two-liner if loaded into small frames, or full-blown with a
1096 large red "BLOCKED" banner if space allows.
1099 If you prefer the banners to be blocked by images, you must see to it that
1100 the HTML documents in which they are embedded are not blocked. Clicking
1101 the <quote>See why</quote> link offered in the substitute page will show
1102 you which rule blocked the page. After changing the rule and un-blocking
1103 the HTML documents, the browser will try to load the actual banner images
1104 and the usual image blocking will (hopefully!) kick in.
1109 <sect2 renderas="sect3" id="srvany">
1110 <title>Can Privoxy run as a service
1111 on Win2K/NT/XP?</title>
1114 Yes. Version 3.0.5 introduces full <application>Windows</application> service
1115 functionality. See <ulink url="../user-manual/installation.html#installation-pack-win">
1116 the <citetitle>User Manual</citetitle></ulink> for details on how to install and configure
1117 <application>Privoxy</application> as a service.
1120 Earlier ]]>3.x versions could run as a system service using <command>srvany.exe</command>.
1121 See the discussion at <ulink
1122 url="http://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118">http://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118</ulink>,
1123 for details, and a sample configuration.
1128 <sect2 renderas="sect3" id="otherproxy">
1129 <title>How can I make Privoxy work with other
1130 proxies like Squid or Tor?</title>
1132 This can be done and is often useful to combine the benefits of
1133 <application>Privoxy</application> with those of a another proxy.
1135 url="../user-manual/config.html#FORWARDING">forwarding chapter</ulink>
1136 in the <ulink url="../user-manual/index.html">User Manual</ulink> which
1137 describes how to do this, and the <link linkend="TOR">
1138 How do I use Privoxy together with
1139 Tor</link> section below.
1143 <sect2 renderas="sect3" id="port-80">
1144 <title>Can I just set Privoxy to use port 80
1145 and thus avoid individual browser configuration?</title>
1148 No, its more complicated than that. This only works with special kinds
1149 of proxies known as <quote>intercepting</quote> proxies (see below).
1154 <sect2 renderas="sect3" id="transparent">
1155 <title>Can Privoxy run as a <quote>transparent
1156 </quote> proxy?</title>
1158 The whole idea of Privoxy is to modify client requests
1159 and server responses in all sorts of ways and therefore
1160 it's not a transparent proxy as described in
1161 <ulink url="http://tools.ietf.org/html/rfc2616">RFC 2616</ulink>.
1164 However, some people say <quote>transparent proxy</quote> when they
1165 mean <quote>intercepting proxy</quote>. If you are one of them,
1166 please read the <ulink url="#intercepting">next entry</ulink>.
1171 <sect2 renderas="sect3" id="intercepting">
1172 <title>Can Privoxy run as a <quote>intercepting</quote> proxy?</title>
1174 <application>Privoxy</application> can't intercept traffic itself,
1175 but it can handle requests that where intercepted and redirected
1176 with a packet filter (like <application>PF</application> or
1177 <application>iptables</application>), as long as the <literal>Host</literal>
1181 As the <literal>Host</literal> header is required by HTTP/1.1 and as most
1182 web sites don't work if it isn't set, this limitation shouldn't be a
1186 Please refer to your packet filter's documentation to learn how to
1187 intercept and redirect traffic into <application>Privoxy</application>. Afterward you just have
1188 to configure <application>Privoxy</application> to
1189 <ulink url="../user-manual/config.html#ACCEPT-INTERCEPTED-REQUESTS">accept intercepted requests</ulink>.
1194 <sect2 renderas="sect3" id="outlook">
1195 <title>How can I configure Privoxy for use with Outlook
1198 <application>Outlook Express</application> uses <application>Internet Explorer</application>
1199 components to both render HTML, and fetch any HTTP requests that may be embedded in an HTML email.
1200 So however you have <application>Privoxy</application> configured to work
1201 with IE, this configuration should automatically be shared.
1205 <sect2 renderas="sect3" id="outlook-more">
1206 <title>How can I have separate rules just for HTML mail?</title>
1208 The short answer is, you can't. <application>Privoxy</application> has no way
1209 of knowing which particular application makes a request, so there is no way to
1210 distinguish between web pages and HTML mail.
1211 <application>Privoxy</application> just blindly proxies all requests. In the
1212 case of <application>Outlook Express</application> (see above), OE uses
1213 IE anyway, and there is no way for <application>Privoxy</application> to ever
1214 be able to distinguish between them (nor could any other proxy type application for
1218 For a good discussion of some of the issues involved (including privacy and
1219 security issues), see
1220 <ulink url="http://sourceforge.net/tracker/?func=detail&atid=211118&aid=629518&group_id=11118">http://sourceforge.net/tracker/?func=detail&atid=211118&aid=629518&group_id=11118</ulink>.
1224 <sect2 renderas="sect3" id="sneaky-cookies">
1225 <title>I sometimes notice cookies sneaking through. How?</title>
1228 url="http://en.wikipedia.org/wiki/Browser_cookie">Cookies</ulink> can be
1229 set in several ways. The classic method is via the
1230 <literal>Set-Cookie</literal> HTTP header. This is straightforward, and an
1231 easy one to manipulate, such as the &my-app; concept of
1232 <ulink url="../user-manual/actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</ulink>.
1233 There is also the possibility of using
1234 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink> to
1235 set cookies (&my-app; calls these <literal>content-cookies</literal>). This
1236 is trickier because the syntax can vary widely, and thus requires a certain
1237 amount of guesswork. It is not realistic to catch all of these short of
1238 disabling Javascript, which would break many sites. And lastly, if the
1239 cookies are embedded in a HTTPS/SSL secure session via Javascript, they are beyond
1240 <application>Privoxy's</application> reach.
1243 All in all, &my-app; can help manage cookies in general, can help minimize
1244 the loss of privacy posed by cookies, but can't realistically stop all
1249 <sect2 renderas="sect3" id="evil-cookies">
1250 <title>Are all cookies bad? Why?</title>
1252 No, in fact there are many beneficial uses of
1254 url="http://en.wikipedia.org/wiki/Browser_cookie">cookies</ulink>. Cookies are just a
1255 method that browsers can use to store data between pages, or between browser
1256 sessions. Sometimes there is a good reason for this, and the user's life is a
1257 bit easier as a result. But there is a long history of some websites taking
1258 advantage of this layer of trust, and using the data they glean from you and
1259 your browsing habits for their own purposes, and maybe to your potential
1260 detriment. Such sites are using you and storing their data on your system.
1261 That is why the privacy conscious watch from whom those cookies come, and why
1262 they really <emphasis>need</emphasis> to be there.
1266 <ulink url="http://en.wikipedia.org/wiki/Browser_cookie">Wikipedia cookie
1267 definition</ulink> for more.
1271 <sect2 renderas="sect3" id="allow-cookies">
1272 <title>How can I allow permanent cookies for my trusted sites?</title>
1275 There are several actions that relate to cookies. The default behavior is to
1276 allow only <quote>session cookies</quote>, which means the cookies only last
1277 for the current browser session. This eliminates most kinds of abuse related
1278 to cookies. But there may be cases where you want cookies to last.
1281 To disable all cookie actions, so that cookies are allowed unrestricted,
1282 both in and out, for <literal>example.com</literal>:
1286 { -crunch-incoming-cookies -crunch-outgoing-cookies -session-cookies-only -filter{content-cookies} }
1287 .example.com</screen>
1290 Place the above in <filename>user.action</filename>. Note that some of these may
1291 be off by default anyway, so this might be redundant, but there is no harm
1292 being explicit in what you want to happen. <filename>user.action</filename>
1293 includes an alias for this situation, called
1294 <literal>allow-all-cookies</literal>.
1298 <sect2 renderas="sect3" id="multiples">
1299 <title>Can I have separate configurations for different users?</title>
1301 Each instance of <application>Privoxy</application> has its own
1302 configuration, including such attributes as the TCP port that it listens on.
1303 What you can do is run multiple instances of <application>Privoxy</application>, each with
1305 <ulink url="../user-manual/config.html#LISTEN-ADDRESS">listen-address</ulink>
1306 configuration setting, and configuration path, and then
1307 each of these can have their own configurations. Think of it as per-port
1311 Simple enough for a few users, but for large installations, consider having
1312 groups of users that might share like configurations.
1316 <sect2 renderas="sect3" id="whitelists">
1317 <title>Can I set-up Privoxy as a whitelist of
1318 <quote>good</quote> sites?</title>
1320 Sure. There are a couple of things you can do for simple white-listing.
1321 Here's one real easy one:
1324 ############################################################
1326 ############################################################
1327 { <ulink url="../user-manual/actions-file.html#BLOCK">+block</ulink> }
1328 / # Block *all* URLs
1330 ############################################################
1332 ############################################################
1333 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> }
1336 games.example.com</screen>
1338 This allows access to only those three sites by first blocking all URLs, and
1339 then subsequently allowing three specific exceptions.
1342 A more interesting approach is <application>Privoxy's</application>
1343 <literal>trustfile</literal> concept, which incorporates the notion of
1344 <quote>trusted referrers</quote>. See the <ulink
1345 url="../user-manual/config.html#TRUSTFILE">User Manual Trust</ulink>
1349 These are fairly simple approaches and are not completely foolproof. There
1350 are various other configuration options that should be disabled (described
1351 elsewhere here and in <ulink url="../user-manual/">the User Manual</ulink>)
1352 so that users can't modify their own configuration and easily circumvent the
1357 <sect2 renderas="sect3" id="no-adblock">
1358 <title>How can I turn off ad-blocking?</title>
1360 Ad blocking is achieved through a complex application of various &my-app;
1361 <ulink url="../user-manual/actions-file.html">actions</ulink>. These
1362 actions are deployed against simple images, banners, flash animations,
1363 text pages, JavaScript, pop-ups and pop-unders, etc., so its not as simple as
1364 just turning one or two actions off. The various actions that make up
1365 &my-app; ad blocking are hard-coded into the default configuration files. It
1366 has been assumed that everyone using &my-app; is interested in this
1370 If you want to do without this, there are several approaches you can take:
1371 You can manually undo the many block rules in
1372 <filename>default.action</filename>. Or even easier, just create your own
1373 <filename>default.action</filename> file from scratch without the many ad
1374 blocking rules, and corresponding exceptions. Or lastly, if you are not
1375 concerned about the additional blocks that are done for privacy reasons, you
1376 can very easily over-ride <emphasis>all</emphasis> blocking with the
1377 following very simple rule in your <filename>user.action</filename>:
1381 # Unblock everybody, everywhere
1382 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> }
1383 / # UN-Block *all* URLs</screen>
1386 Or even a more comprehensive reversing of various ad related actions:
1390 # Unblock everybody, everywhere, and turn off appropriate filtering, etc
1391 { <ulink url="../user-manual/actions-file.html#BLOCK">-block</ulink> \
1392 <ulink url="../user-manual/actions-file.html#FILTER-BANNERS-BY-SIZE">-filter{banners-by-size}</ulink> \
1393 <ulink url="../user-manual/actions-file.html#FILTER-BANNERS-BY-LINK">-filter{banners-by-link}</ulink> \
1394 <literal>allow-popups</literal> \
1396 / # UN-Block *all* URLs and allow ads</screen>
1399 This last <quote>action</quote> in this compound statement,
1400 <literal>allow-popups</literal>, is an <ulink
1401 url="../user-manual/actions-file.html#ALIASES">alias</ulink> that disables
1402 various pop-up blocking features.
1406 <sect2 renderas="sect3" id="templates">
1407 <title>How can I have custom template pages, like the
1408 <emphasis>BLOCKED</emphasis> page?</title>
1410 &my-app; <quote>templates</quote> are specialized text files utilized by
1411 &my-app; for various purposes and can easily be modified using any text
1412 editor. All the template pages are installed in a sub-directory appropriately
1413 named: <filename>templates</filename>. Knowing something about HTML syntax
1414 will of course be helpful. You cannot rename any of these files, or create
1415 completely new templates, that is not possible. But you can change the page
1416 content to whatever you like. Be forewarned that these files are subject to
1417 being overwritten during upgrades, so be sure to save any customizations.
1421 <sect2 renderas="sect3" id="blockall">
1422 <title>How can I remove the <quote>Go There Anyway</quote> link from
1423 the <emphasis>BLOCKED</emphasis> page?</title>
1425 There is more than one way to do it.
1428 Editing the BLOCKED template page (see above) may dissuade some users, but
1429 this method is easily circumvented. Where you need this level of control, you
1430 should build &my-app; from source, and enable various features that are
1431 available as compile-time options. You should
1432 <command>configure</command> the sources as follows:
1436 ./configure --disable-toggle --disable-editor --disable-force</screen>
1439 This will create an executable with hard-coded security features so that
1440 &my-app; does not allow easy bypassing of blocked sites, or changing the
1441 current configuration via any connected user's web browser.
1444 Note that all of these features can also be toggled on/off via options in
1445 <application>Privoxy's</application> main <ulink
1446 url="../user-manual/config.html#ACCESS-CONTROL">config</ulink> file which
1447 means you don't have to recompile anything.
1453 <!-- ~ End section ~ -->
1456 <!-- ~~~~~ New section ~~~~~ -->
1458 <sect1 id="misc"><title>Miscellaneous</title>
1460 <sect2 renderas="sect3">
1461 <title id="slowsme">How much does Privoxy slow my browsing down? This
1462 has to add extra time to browsing.</title>
1464 How much of an impact depends on many things, including the CPU of the host
1465 system, how aggressive the configuration is, which specific actions are being triggered,
1466 the size of the page, the bandwidth of the connection, etc.
1469 Overall, it should not slow you down any in real terms, and may actually help
1470 speed things up since ads, banners and other junk are not typically being
1471 retrieved and displayed. The actual processing time required by
1472 <application>Privoxy</application> itself for each page, is relatively small
1473 in the overall scheme of things, and happens very quickly. This is typically
1474 more than offset by time saved not downloading and rendering ad images (if ad
1475 blocking is being used).
1479 <quote>Filtering</quote> content via the <literal><ulink
1480 url="../user-manual/actions-file.html#FILTER">filter</ulink></literal> or
1482 url="../user-manual/actions-file.html#DEANIMATE-GIFS">deanimate-gifs</ulink></literal>
1483 actions may cause a perceived slowdown, since the entire document
1484 needs to be buffered before displaying. And on very large documents, filtering may have
1485 some measurable impact. How much depends on the page size, the actual
1486 definition of the filter(s), etc. See below. Most other actions have little
1487 to no impact on speed.
1490 Also, when filtering is enabled but zlib support isn't available, compression
1491 is often disabled (see <ulink
1492 url="../user-manual/actions-file.html#PREVENT-COMPRESSION">prevent-compression</ulink>).
1493 This can have an impact on speed as well. Again, the page size, etc. will
1494 determine how much of an impact.
1500 <sect2 renderas="sect3" id="loadingtimes"><title>I notice considerable
1501 delays in page requests. What's wrong?</title>
1503 If you use any <literal><ulink
1504 url="../user-manual/actions-file.html#FILTER">filter</ulink></literal> action,
1505 such as filtering banners by size, web-bugs etc, or the <literal><ulink
1506 url="../user-manual/actions-file.html#DEANIMATE-GIFS">deanimate-gifs</ulink></literal>
1507 action, the entire document must be loaded into memory in order for the filtering
1508 mechanism to work, and nothing is sent to the browser during this time.
1511 The loading time typically does not really change much in real numbers, but
1512 the feeling is different, because most browsers are able to start rendering
1513 incomplete content, giving the user a feeling of "it works". This effect is
1514 more noticeable on slower dialup connections. Extremely large documents
1515 may have some impact on the time to load the page where there is filtering
1516 being done. But overall, the difference should be very minimal. If there is a
1517 big impact, then probably some other situation is contributing (like
1518 anti-virus software).
1521 Filtering is automatically disabled for inappropriate MIME types. But note
1522 that if the web server mis-reports the MIME type, then content that should
1523 not be filtered, could be. <application>Privoxy</application> only knows how
1524 to differentiate filterable content because of the MIME type as reported by
1525 the server, or because of some configuration setting that enables/disables
1530 <sect2 renderas="sect3" id="configurl"><title>What are "http://config.privoxy.org/" and
1531 "http://p.p/"?</title>
1533 <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink> is the
1534 address of <application>Privoxy</application>'s built-in user interface, and
1535 <ulink url="http://p.p/">http://p.p/</ulink> is a shortcut for it.
1538 Since <application>Privoxy</application> sits between your web browser and the Internet,
1539 it can simply intercept requests for these addresses and answer them with its built-in
1540 <quote>web server</quote>.
1543 This also makes for a good test for your browser configuration: If entering the
1544 URL <ulink url="http://config.privoxy.org/">http://config.privoxy.org/</ulink>
1545 takes you to a page saying <quote>This is Privoxy ...</quote>, everything is OK.
1546 If you get a page saying <quote>Privoxy is not working</quote> instead, then
1547 your browser didn't use <application>Privoxy</application> for the request,
1548 hence it could not be intercepted, and you have accessed the <emphasis>real</emphasis>
1549 web site at config.privoxy.org.
1555 out of date 09/02/06 HB
1556 <sect2 renderas="sect3" id="blocklist"><title>Do you still maintain the blocklists?</title>
1558 No. The patterns for blocking now reside (among other things) in the <ulink
1559 url="../user-manual/actions-file.html">actions files</ulink>, which are
1560 actively maintained instead. See next question ...
1564 <sect2 renderas="sect3" id="newads"><title>How can I submit new ads, or report
1567 Please see the <link linkend="contact">Contact section</link> for
1568 various ways to interact with the developers.
1573 <sect2 renderas="sect3" id="newads2"><title>If I do submit missed ads, will
1574 they be included in future updates?</title>
1576 Whether such submissions are eventually included in the
1577 <filename>default.action</filename> configuration file depends on how
1578 significant the issue is. We of course want to address any potential
1579 problem with major, high-profile sites such as <citetitle>Google</citetitle>,
1580 <citetitle>Yahoo</citetitle>, etc. Any site with global or regional reach,
1581 has a good chance of being a candidate. But at the other end of the spectrum
1582 are any number of smaller, low-profile sites such as for local clubs or
1583 schools. Since their reach and impact are much less, they are best handled by
1584 inclusion in the user's <filename>user.action</filename>, and thus would be
1585 unlikely to be included.
1591 <sect2 renderas="sect3" id="noonecares"><title>Why doesn't anyone answer my support
1594 Rest assured that it has been read and considered. Why it is not answered,
1595 could be for various reasons, including no one has a good answer for it, no
1596 one has had time to yet investigate it thoroughly, it has been reported
1597 numerous times already, or because not enough information was provided to help
1598 us help you. Your efforts are not wasted, and we do appreciate them.
1604 <sect2 renderas="sect3" id="ip"><title>How can I hide my IP address?</title>
1606 If you run both the browser and &my-app; locally, you cannot hide your IP
1607 address with <application>Privoxy</application> or ultimately any other
1608 software alone. The server needs to know your IP address so that it knows
1609 where to send the responses back.
1612 There are many publicly usable "anonymous" proxies out there, which
1613 provide a further level of indirection between you and the web server.
1616 However, these proxies are called "anonymous" because you don't need
1617 to authenticate, not because they would offer any real anonymity.
1618 Most of them will log your IP address and make it available to the
1619 authorities in case you violate the law of the country they run in. In fact
1620 you can't even rule out that some of them only exist to *collect* information
1621 on (those suspicious) people with a more than average preference for privacy.
1624 Your best bet is to chain <application>Privoxy</application>
1625 with <ulink url="http://tor.eff.org/">Tor</ulink>,
1626 an <ulink url="http://www.eff.org/">EFF</ulink> supported onion routing system.
1627 The configuration details can be found in
1628 <ulink url="#TOR">How do I use <application>Privoxy</application> together
1629 with <application>Tor</application> section</ulink>
1634 <sect2 renderas="sect3">
1635 <title id="anonforsure">Can Privoxy guarantee I am anonymous?</title>
1637 No. Your chances of remaining anonymous are greatly improved, but unless you
1638 <ulink url="#TOR">chain <application>Privoxy</application> with <application>Tor</application></ulink>
1639 or a similar system and know what you're doing when it comes to configuring
1640 the rest of your system, it would be safest to assume that everything you do
1641 on the Web can be traced back to you.
1644 <application>Privoxy</application> can remove various information about you,
1645 and allows <emphasis>you</emphasis> more freedom to decide which sites
1646 you can trust, and what details you want to reveal. But it neither
1647 hides your IP address, nor can it guarantee that the rest of the system
1648 behaves correctly. There are several possibilities how a web sites can find
1649 out who you are, even if you are using a strict <application>Privoxy</application>
1650 configuration and chained it with <application>Tor</application>.
1653 Most of <application>Privoxy's</application> privacy-enhancing features can be easily subverted
1654 by an insecure browser configuration, therefore you should use a browser that can
1655 be configured to only execute code from trusted sites, and be careful which sites you trust.
1656 For example there is no point in having <application>Privoxy</application>
1657 modify the User-Agent header, if websites can get all the information they want
1658 through JavaScript, ActiveX, Flash, Java etc.
1661 A few browsers disclose the user's email address in certain situations, such
1662 as when transferring a file by FTP. <application>Privoxy</application>
1663 does not filter FTP. If you need this feature, or are concerned about the
1664 mail handler of your browser disclosing your email address, you might
1665 consider products such as <application>NSClean</application>.
1668 Browsers available only as binaries could use non-standard headers to give
1669 out any information they can have access to: see the manufacturer's license
1670 agreement. It's impossible to anticipate and prevent every breach of privacy
1671 that might occur. The professionally paranoid prefer browsers available as
1672 source code, because anticipating their behavior is easier. Trust the source,
1678 <sect2 renderas="sect3">
1679 <title id="proxytest">A test site says I am not using a Proxy.</title>
1681 Good! Actually, they are probably testing for some other kinds of proxies.
1682 Hiding yourself completely would require additional steps.
1686 <sect2 renderas="sect3" id="tor"><title>How do I use Privoxy
1687 together with Tor?</title>
1689 Before you configure <application>Privoxy</application> to use
1690 <ulink url="https://www.torproject.org/">Tor</ulink>,
1691 please follow the <citetitle>User Manual</citetitle> chapters
1692 <ulink url="../user-manual/installation.html">2. Installation</ulink> and
1693 <ulink url="../user-manual/startup.html">5. Startup</ulink> to make sure
1694 <application>Privoxy</application> itself is setup correctly.
1697 If it is, refer to <ulink url="https://www.torproject.org/documentation.html">Tor's
1698 extensive documentation</ulink> to learn how to install <application>Tor</application>,
1699 and make sure <application>Tor</application>'s logfile says that
1700 <quote>Tor has successfully opened a circuit</quote> and it
1701 <quote>looks like client functionality is working</quote>.
1704 If either <application>Tor</application> or <application>Privoxy</application>
1705 isn't working, their combination most likely will neither. Testing them on their
1706 own will also help you to direct problem reports to the right audience.
1707 If <application>Privoxy</application> isn't working, don't bother the
1708 <application>Tor</application> developers. If <application>Tor</application>
1709 isn't working, don't send bug reports to the <application>Privoxy</application> Team.
1712 If you verified that <application>Privoxy</application> and <application>Tor</application>
1713 are working, it is time to connect them. As far as <application>Privoxy</application>
1714 is concerned, <application>Tor</application> is just another proxy that can be reached
1715 by socks4 or socks4a. Most likely you are interested in <application>Tor</application>
1716 to increase your anonymity level, therefore you should use socks4a, to make sure DNS requests are
1717 done through <application>Tor</application> and thus invisible to your local network.
1722 Since <application>Privoxy</application> 3.0.5, its
1723 <ulink url="../user-manual/config.html">main configuration file</ulink>
1724 is already prepared for <application>Tor</application>, if you are using a
1725 default <application>Tor</application> configuration and run it on the same
1726 system as &my-app;, you just have to edit the
1727 <ulink url="../user-manual/config.html#FORWARDING">forwarding section</ulink>
1728 and uncomment the line:
1732 # forward-socks4a / 127.0.0.1:9050 .
1736 This is enough to reach the Internet, but additionally you might want to
1737 uncomment the following forward rules, to make sure your local network is still
1738 reachable through Privoxy:
1742 # forward 192.168.*.*/ .
1743 # forward 10.*.*.*/ .
1744 # forward 127.*.*.*/ .
1748 Unencrypted connections to systems in these address ranges will
1749 be as (un)secure as the local network is, but the alternative is
1750 that your browser can't reach the network at all. Then again,
1751 that may actually be desired and if you don't know for sure
1752 that your browser has to be able to reach the local network,
1753 there's no reason to allow it.
1756 If you want your browser to be able to reach servers in your local
1757 network by using their names, you will need additional exceptions
1758 that look like this:
1762 # forward localhost/ .
1766 Save the modified configuration file and open
1767 <ulink url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status/</ulink>
1768 in your browser, confirm that <application>Privoxy</application> has reloaded its configuration
1769 and that there are no other forward lines, unless you know that you need them. If everything looks good,
1771 <ulink url="https://wiki.torproject.org/wiki/TheOnionRouter/TorFAQ#head-0e1cc2ac330ede8c6ad1ac0d0db0ac163b0e6143">Tor
1772 Faq 4.2</ulink> to learn how to verify that you are really using <application>Tor</application>.
1775 Afterward, please take the time to at least skim through the rest
1776 of <application>Tor's</application> documentation. Make sure you understand
1777 what <application>Tor</application> does, why it is no replacement for
1778 application level security, and why you shouldn't use it for unencrypted logins.
1782 <sect2 renderas="sect3">
1783 <title id="sitebreak">Might some things break because header information or
1784 content is being altered?</title>
1787 Definitely. It is common for sites to use browser type, browser version,
1788 HTTP header content, and various other techniques in order to dynamically
1789 decide what to display and how to display it. What you see, and what I see,
1790 might be very different. There are many, many ways that this can be handled,
1791 so having hard and fast rules, is tricky.
1795 The <quote>User-Agent</quote> is sometimes used in this way to identify
1796 the browser, and adjust content accordingly.
1800 Also, different browsers use different encodings of Russian and Czech
1801 characters, certain web servers convert pages on-the-fly according to the
1802 User Agent header. Giving a <quote>User Agent</quote> with the wrong
1803 operating system or browser manufacturer causes some sites in these languages
1804 to be garbled; Surfers to Eastern European sites should change it to
1805 something closer. And then some page access counters work by looking at the
1806 <quote>Referer</quote> header; they may fail or break if unavailable. The
1807 weather maps of Intellicast have been blocked by their server when no
1808 <quote>Referer</quote> or cookie is provided, is another example. (But you
1809 can forge both headers without giving information away). There are
1810 many other ways things that can go wrong when trying to fool a web server. The
1811 results of which could inadvertently cause pages to load incorrectly,
1812 partially, or even not at all. And there may be no obvious clues as to just
1813 what went wrong, or why. Nowhere will there be a message that says
1814 <quote><emphasis>Turn off <literal>fast-redirects</literal> or else!</emphasis>
1819 Similar thoughts apply to modifying JavaScript, and, to a lesser degree,
1824 If you have problems with a site, you will have to adjust your configuration
1825 accordingly. Cookies are probably the most likely adjustment that may
1826 be required, but by no means the only one.
1832 <sect2 renderas="sect3">
1833 <title id="caching">Can Privoxy act as a <quote>caching</quote> proxy to
1834 speed up web browsing?</title>
1836 No, it does not have this ability at all. You want something like
1837 <ulink url="http://www.squid-cache.org/">Squid</ulink> or
1838 <ulink url="http://www.pps.jussieu.fr/~jch/software/polipo/">Polipo</ulink> for this.
1839 And, yes, before you ask, <application>Privoxy</application> can co-exist
1840 with other kinds of proxies like <application>Squid</application>.
1841 See the <ulink url="../user-manual/config.html#FORWARDING">forwarding
1842 chapter</ulink> in the <ulink url="../user-manual/index.html">user
1843 manual</ulink> for details.
1847 <sect2 renderas="sect3">
1848 <title id="firewall">What about as a firewall? Can Privoxy protect me?</title>
1850 Not in the way you mean, or in the way some firewall vendors claim they can.
1851 <application>Privoxy</application> can help protect your privacy, but can't
1852 protect your system from intrusion attempts. It is, of course, perfectly possible
1853 to use <emphasis>both</emphasis>.
1857 <sect2 renderas="sect3">
1858 <title id="wasted">I have large empty spaces / a checkerboard pattern now where
1859 ads used to be. Why?</title>
1861 It is technically possible to eliminate banners and ads in a way that frees
1862 their allocated page space. This could easily be done by blocking with
1863 <application>Privoxy's</application> filters,
1864 and eliminating the <emphasis>entire</emphasis> image references from the
1868 But, this would consume considerably more CPU resources (IOW, slow things
1869 down), would likely destroy the layout of some web pages which rely on the
1870 banners utilizing a certain amount of page space, and might fail in other
1871 cases, where the screen space is reserved (e.g. by HTML tables for instance).
1872 Also, making ads and banners disappear without any trace complicates
1873 troubleshooting, and would sooner or later be problematic.
1876 The better alternative is to instead let them stay, and block the resulting
1877 requests for the banners themselves as is now the case. This leaves either
1878 empty space, or the familiar checkerboard pattern.
1881 So the developers won't support this in the default configuration, but you
1882 can of course define appropriate filters yourself to achieve this.
1886 <sect2 renderas="sect3">
1887 <title id="ssl">How can Privoxy filter Secure (HTTPS) URLs?</title>
1889 Since secure HTTP connections are encrypted SSL sessions between your browser
1890 and the secure site, and are meant to be reliably <emphasis>secure</emphasis>,
1891 there is little that <application>Privoxy</application> can do but hand the raw
1892 gibberish data though from one end to the other unprocessed.
1895 The only exception to this is blocking by host patterns, as the client needs
1896 to tell <application>Privoxy</application> the name of the remote server,
1897 so that <application>Privoxy</application> can establish the connection.
1898 If that name matches a host-only pattern, the connection will be blocked.
1901 As far as ad blocking is concerned, this is less of a restriction than it may
1902 seem, since ad sources are often identifiable by the host name, and often
1903 the banners to be placed in an encrypted page come unencrypted nonetheless
1904 for efficiency reasons, which exposes them to the full power of
1905 <application>Privoxy</application>'s ad blocking.
1908 <quote>Content cookies</quote> (those that are embedded in the actual HTML or
1909 JS page content, see <literal><ulink
1910 url="../user-manual/actions-file.html#FILTER-CONTENT-COOKIES">filter{content-cookies}</ulink></literal>),
1911 in an SSL transaction will be impossible to block under these conditions.
1912 Fortunately, this does not seem to be a very common scenario since most
1913 cookies come by traditional means.
1918 <sect2 renderas="sect3">
1919 <title id="secure">Privoxy runs as a <quote>server</quote>. How
1920 secure is it? Do I need to take any special precautions?</title>
1922 On Unix-like systems, <application>Privoxy</application> can run as a non-privileged
1923 user, which is how we recommend it be run. Also, by default
1924 <application>Privoxy</application> listens to requests from <quote>localhost</quote>
1928 The server aspect of <application>Privoxy</application> is not itself directly
1929 exposed to the Internet in this configuration. If you want to have
1930 <application>Privoxy</application> serve as a LAN proxy, this will have to
1931 be opened up to allow for LAN requests. In this case, we'd recommend
1932 you specify only the LAN gateway address, e.g. 192.168.1.1, in the main
1933 <application>Privoxy</application> configuration file and check all <ulink
1934 url="../user-manual/config.html#ACCESS-CONTROL">access control and security
1935 options</ulink>. All LAN hosts can then use this as their proxy address
1936 in the browser proxy configuration, but <application>Privoxy</application>
1937 will not listen on any external interfaces. ACLs can be defined in addition,
1938 and using a firewall is always good too. Better safe than sorry.
1943 <sect2 renderas="sect3" id="turnoff">
1944 <title>How can I temporarily disable Privoxy?</title>
1946 The easiest way is to access <application>Privoxy</application> with your
1947 browser by using the remote toggle URL: <ulink
1948 url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>.
1949 See the <ulink url="../user-manual/appendix.html#BOOKMARKLETS">Bookmarklets section</ulink>
1950 of the <citetitle>User Manual</citetitle> for an easy way to access this
1956 <sect2 renderas="sect3" id="reallyoff">
1957 <title>When <quote>disabled</quote> is Privoxy totally
1958 out of the picture?</title>
1960 No, this just means all optional filtering and actions are disabled.
1961 <application>Privoxy</application> is still acting as a proxy, but just not
1962 doing any of the things that <application>Privoxy</application> would
1963 normally be expected to do. It is still a <quote>middle-man</quote> in
1964 the interaction between your browser and web sites. See below to bypass
1969 <sect2 renderas="sect3" id="turnoff2">
1970 <title>How can I tell Privoxy to totally ignore certain sites?</title>
1972 Bypassing a proxy, or proxying based on arbitrary criteria, is purely a browser
1973 configuration issue, not a &my-app; issue. Modern browsers typically do have
1974 settings for not proxying certain sites. Check your browser's help files.
1979 <sect2 renderas="sect3" id="crunch">
1980 <title>My logs show Privoxy <quote>crunches</quote>
1981 ads, but also its own internal CGI pages. What is a <quote>crunch</quote>?</title>
1983 A <quote>crunch</quote> simply means <application>Privoxy</application> intercepted
1984 <emphasis>something</emphasis>, nothing more. Often this is indeed ads or
1985 banners, but <application>Privoxy</application> uses the same mechanism for
1986 trapping requests for its own internal pages. For instance, a request for
1987 <application>Privoxy's</application> configuration page at: <ulink
1988 url="http://config.privoxy.org">http://config.privoxy.org</ulink>, is
1989 intercepted (i.e. it does not go out to the 'net), and the familiar CGI
1990 configuration is returned to the browser, and the log consequently will show
1991 a <quote>crunch</quote>.
1994 Since version 3.0.7, Privoxy will also log the crunch reason.
1995 If you are using an older version you might want to upgrade.
1999 <sect2 renderas="sect3" id="downloads">
2000 <title>Can Privoxy effect files that I download
2001 from a webserver? FTP server?</title>
2003 From the webserver's perspective, there is no difference between
2004 viewing a document (i.e. a page), and downloading a file. The same is true of
2005 <application>Privoxy</application>. If there is a match for a <literal><ulink
2006 url="../user-manual/actions-file.html#BLOCK">block</ulink></literal> pattern,
2007 it will still be blocked, and of course this is obvious.
2010 Filtering is potentially more of a concern since the results are not always
2011 so obvious, and the effects of filtering are there whether the file is simply
2012 viewed, or downloaded. And potentially whether the content is some obnoxious
2013 advertisement, or Mr. Jimmy's latest/greatest source code jewel. Of course,
2014 one of these presumably is <quote>bad</quote> content that we don't want, and
2015 the other is <quote>good</quote> content that we do want.
2016 <application>Privoxy</application> is blind to the differences, and can only
2017 distinguish <quote>good from bad</quote> by the configuration parameters
2018 <emphasis>we</emphasis> give it.
2021 <application>Privoxy</application> knows the differences in files according
2022 to the <quote>Content Type</quote> as reported by the webserver. If this is
2023 reported accurately (e.g. <quote>application/zip</quote> for a zip archive),
2024 then <application>Privoxy</application> knows to ignore these where
2025 appropriate. <application>Privoxy</application> potentially can filter HTML
2026 as well as plain text documents, subject to configuration parameters of
2027 course. Also, documents that are of an unknown type (generally assumed to be
2028 <quote>text/plain</quote>) can be filtered, as will those that might be
2029 incorrectly reported by the webserver. If such a file is a downloaded file
2030 that is intended to be saved to disk, then any content that might have been
2031 altered by filtering, will be saved too, for these (probably rare) cases.
2034 Note that versions later than 3.0.2 do NOT filter document types reported as
2035 <quote>text/plain</quote>. Prior to this, <application>Privoxy</application>
2036 did filter this document type.
2039 In short, filtering is <quote>ON</quote> if a) the content type as reported
2040 by the webserver is appropriate <emphasis>and</emphasis> b) the configuration
2041 allows it (or at least does not disallow it). That's it. There is no magic
2042 cookie anywhere to say this is <quote>good</quote> and this is
2043 <quote>bad</quote>. It's the configuration that lets it all happen or not.
2046 If you download text files, you probably do not want these to be filtered,
2047 particularly if the content is source code, or other critical content. Source
2048 code sometimes might be mistaken for Javascript (i.e. the kind that might
2049 open a pop-up window). It is recommended to turn off filtering for download
2050 sites (particularly if the content may be plain text files and you are using
2051 version 3.0.2 or earlier) in your <filename>user.action</filename> file. And
2052 also, for any site or page where making <emphasis>any</emphasis> changes at
2053 all to the content is to be avoided.
2056 <application>Privoxy</application> does not do FTP at all, only HTTP
2057 and HTTPS (SSL) protocols, so please don't try.
2061 <sect2 renderas="sect3" id="downloads2">
2062 <title>I just downloaded a Perl script, and Privoxy
2063 altered it! Yikes, what is wrong!</title>
2069 <sect2 renderas="sect3" id="hostsfile">
2070 <title>Should I continue to use a <quote>HOSTS</quote> file for ad-blocking?</title>
2072 One time-tested technique to defeat common ads is to trick the local DNS
2073 system by giving a phony IP address for the ad generator in the local
2074 <filename>HOSTS</filename> file, typically using <literal>127.0.0.1</literal>, aka
2075 <literal>localhost</literal>. This effectively blocks the ad.
2078 There is no reason to use this technique in conjunction with
2079 <application>Privoxy</application>. <application>Privoxy</application>
2080 does essentially the same thing, much more elegantly and with much more
2081 flexibility. A large <filename>HOSTS</filename> file, in fact, not only
2082 duplicates effort, but may get in the way and seriously slow down your system.
2083 It is recommended to remove such entries from your <filename>HOSTS</filename> file. If you think
2084 your hosts list is neglected by <application>Privoxy's </application>
2085 configuration, consider adding your list to your <filename>user.action</filename> file:
2092 ads.galore.example.com
2093 etc.example.com</screen>
2097 <sect2 renderas="sect3" id="seealso">
2098 <title>Where can I find more information about Privoxy
2099 and related issues?</title>
2100 <!-- Include seealso.sgml boilerplate: -->
2102 <!-- end boilerplate -->
2107 <ulink url="../user-manual/seealso.html">user-manual</ulink> for
2113 <sect2 renderas="sect3" id="microsuck">
2114 <title>I've noticed that Privoxy changes <quote>Microsoft</quote> to
2115 <quote>MicroSuck</quote>! Why are you manipulating my browsing?</title>
2118 We're not. The text substitutions that you are seeing are disabled
2119 in the default configuration as shipped. You have either manually
2120 activated the <quote><literal>fun</literal></quote> filter which
2121 is clearly labeled <quote>Text replacements for subversive browsing
2122 fun!</quote> or you are using an older Privoxy version and have implicitly
2123 activated it by choosing the <quote>Adventuresome</quote> profile in the
2124 web-based editor. Please upgrade!
2128 <sect2 renderas="sect3" id="valid">
2129 <title>Does Privoxy produce <quote>valid</quote> HTML (or XHTML)?</title>
2132 Privoxy generates HTML in both its own <quote>templates</quote>, and possibly
2133 whenever there are text substitutions via a &my-app; filter. While this
2134 should always conform to the HTML 4.01 specifications, it has not been
2135 validated against this or any other standard.
2143 <!-- ~~~~~ New section ~~~~~ -->
2145 <sect1 id="trouble">
2146 <title>Troubleshooting</title>
2148 <sect2 renderas="sect3">
2149 <title id="refused">I cannot connect to any websites. Or, I am getting
2150 <quote>connection refused</quote> message with every web page. Why?</title>
2152 There are several possibilities:
2157 <application>Privoxy</application> is not running. Solution: verify
2158 that &my-app; is installed correctly, has not crashed, and is indeed running.
2159 Turn on <application>Privoxy's</application> logging, and look at the logs to see what they say.
2161 <listitem><para>Or your browser is configured for a different port than what
2162 <application>Privoxy</application> is using. Solution: verify that &my-app;
2163 and your browser are set to the same port (<literal>listen-address</literal>).
2165 <listitem><para>Or if using a forwarding rule, you have a configuration problem or a
2166 problem with a host in the forwarding chain. Solution: temporarily alter your
2167 configuration and take the forwarders out of the equation.
2170 Or you have a firewall that is interfering and blocking you. Solution:
2171 try disabling or removing the firewall as a simple test.
2178 <!-- ~~~~~ New section ~~~~~ -->
2179 <sect2 renderas="sect3" id="error503">
2180 <title>Why am I getting a 503 Error (WSAECONNREFUSED) on every page?</title>
2182 More than likely this is a problem with your TCP/IP networking. ZoneAlarm has
2183 been reported to cause this symptom -- even if not running! The solution is
2184 to either fight the ZA configuration, or uninstall ZoneAlarm, and then find
2185 something better behaved in its place. Other personal firewall type products
2186 may cause similar type problems if not configured correctly.
2190 <sect2 renderas="sect3">
2191 <title id="flushit">I just added a new rule, but the steenkin ad is
2192 still getting through. How?</title>
2194 If the ad had been displayed before you added its URL, it will probably be
2195 held in the browser's cache for some time, so it will be displayed without
2196 the need for any request to the server, and <application>Privoxy</application>
2197 will not be involved. Flush the browser's caches, and then try again.
2201 If this doesn't help, you probably have an error in the rule you
2202 applied. Try pasting the full URL of the offending ad into <ulink
2203 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
2204 and see if it really matches your new rule. Blocking ads is like blocking
2205 spam: a lot of tinkering is required to stay ahead of the game. And
2206 remember you need to block the URL of the ad in question, which may be
2207 entirely different from the site URL itself. Most ads are hosted on different
2208 servers than the main site itself. If you right-click on the ad, you should
2209 be able to get all the relevant information you need. Alternately, you can
2210 find the correct URL by looking at <application>Privoxy's</application> logs
2211 (you may need to enable logging in the main config file if its disabled).
2214 Below is a slightly modified real-life log snippet that originates with one
2215 requested URL: <literal>www.example.com</literal> (name of site was changed
2216 for this example, the number of requests is real). You can see in this the
2217 complexity of what goes into making up this one <quote>page</quote>. There
2218 are eight different domains involved here, with thirty two separate URLs
2219 requested in all, making up all manner of images, Shockwave Flash,
2220 JavaScript, CSS stylesheets, scripts, and other related content. Some of this
2221 content is obviously <quote>good</quote> or <quote>bad</quote>, but not all.
2222 Many of the more questionable looking requests, are going to outside domains
2223 that seem to be identifying themselves with suspicious looking names, making
2224 our job a little easier. &my-app; has <quote>crunched</quote> (meaning caught
2225 and BLOCKED) quite a few items in this example, but perhaps missed a few as well.
2230 Request: www.example.com/
2231 Request: www.example.com/favicon.ico
2232 Request: img.example.com/main.css
2233 Request: img.example.com/sr.js
2234 Request: example.betamarker.com/example.html
2235 Request: www.lik-sang.com/Banners/bestsellers/skyscraper.php?likref=BSellers
2236 Request: img.example.com/pb.png
2237 Request: www.google-analytics.com/urchin.js crunch!
2238 Request: www.advertising-department.com/ats/switch.ps.php?26856 crunch!
2239 Request: img.example.com/p.gif
2240 Request: www.popuptraffic.com/assign.php?l=example&mode=behind crunch!
2241 Request: www.popuptraffic.com/scripts/popup.php?hid=5c3cf&tmpl=PBa.tmpl crunch!
2242 Request: www.popuptraffic.com/assign.php?l=example crunch!
2243 Request: www.lik-sang.com/Banners/best_sellers/best_sellers.css
2244 Request: www.adtrak.net/adx.js crunch!
2245 Request: img.example.com/hbg.gif
2246 Request: img.example.com/example.jpg
2247 Request: img.example.com/mt.png
2248 Request: img.example.com/mm.png
2249 Request: img.example.com/mb.png
2250 Request: www.popuptraffic.com/scripts/popup.php?hid=a71b91fa5&tmpl=Ua.tmp crunch!
2251 Request: www.example.com/tracker.js
2252 Request: www.lik-sang.com/Banners/best_sellers/lsi_head.gif
2253 Request: www.adtrak.net/adjs.php?n=020548130&what=zone:61 crunch!
2254 Request: www.adtrak.net/adjs.php?n=463594413&what=zone:58&source=Ua crunch!
2255 Request: www.lik-sang.com/Banners/best_sellers/bottomani.swf
2256 Request: mmm.elitemediagroup.net/install.php?allowpop=no&popupmincook=0&allowsp2=1 crunch!
2257 Request: www.example.com/tracker.js?screen=1400x1050&win=962x693
2258 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=61 crunch!
2259 Request: 66.70.21.80/scripts/click.php?hid=5c3cf599a9efd0320d26&si
2260 Request: 66.70.21.80/img/pixel.gif
2261 Request: www.adtrak.net/adlog.php?bannerid=1309&clientid=439&zoneid=58&source=Ua&block=86400 crunch!
2262 Request: 66.70.21.80/scripts/click.php?hid=a71b9f6504b0c5681fa5&si=Ua
2267 Despite 12 out of 32 requests being blocked, the page looked, and seemed to
2268 behave perfectly <quote>normal</quote> (minus some ads, of course).
2273 <sect2 id="badsite" renderas="sect3">
2274 <title >One of my favorite sites does not work with Privoxy.
2275 What can I do?</title>
2278 First verify that it is indeed a <application>Privoxy</application> problem,
2279 by toggling off <application>Privoxy</application> through <ulink
2280 url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle</ulink>,
2281 and then shift-reloading the problem page (i.e. holding down the shift key
2282 while clicking reload. Alternatively, flush your browser's disk and memory
2287 If the problem went away, we know we have a configuration related problem.
2289 url="http://config.privoxy.org/show-url-info">http://config.privoxy.org/show-url-info</ulink>
2290 and paste the full URL of the page in question into the prompt. See which
2291 actions are being applied to the URL, and which matches in which actions
2292 files are responsible for that. It might be helpful also to look at your logs
2293 for this site too, to see what else might be happening (note: logging may need
2294 to be enabled in the main config file). Many sites are
2295 complex and require a number of related pages to help present their content.
2296 Look at what else might be used by the page in question, and what of that
2297 might be <emphasis>required</emphasis>.
2298 Now, armed with this information, go to
2300 url="http://config.privoxy.org/show-status">http://config.privoxy.org/show-status</ulink>
2301 and select the appropriate actions files for editing. </para>
2303 You can now either look for a section which disables the actions that
2304 you suspect to cause the problem and add a pattern for your site there,
2305 or make up a completely new section for your site. In any case, the recommended
2306 way is to disable only the prime suspect, reload the problem page, and only
2307 if the problem persists, disable more and more actions until you have
2308 identified the culprit. You may or may not want to turn the other actions
2309 on again. Remember to flush your browser's caches in between any such changes!
2312 Alternately, if you are comfortable with a text editor, you can accomplish
2313 the same thing by editing the appropriate actions file. Probably the easiest
2314 way to deal with such problems when editing by hand is to add your
2315 site to a <literal>{ fragile }</literal> section in <filename>user.action</filename>,
2316 which is an alias that turns off most <quote>dangerous</quote>
2317 actions, but is also likely to turn off more actions then needed, and thus lower
2318 your privacy and protection more than necessary,
2321 Troubleshooting actions is discussed in more detail in the <ulink
2322 url="../user-manual/appendix.html#ACTIONSANAT">User Manual appendix,
2323 Troubleshooting: the Anatomy of an Action</ulink>.
2324 There is also an <ulink
2325 url="../user-manual/actions-file.html#ACT-EXAMPLES">actions tutorial</ulink>
2326 with general configuration information and examples.
2329 As a last resort, you can always see if your browser has a setting that will
2330 bypass the proxy setting for selective sites. Modern browsers can do this.
2336 <!-- ~~~~~ New section ~~~~~ -->
2337 <sect2 id="dun" renderas="sect3">
2338 <title>After installing Privoxy, I have to log in
2339 every time I start IE. What gives?</title>
2342 This is a quirk that effects the installation of
2343 <application>Privoxy</application>, in conjunction with Internet Explorer and
2344 Internet Connection Sharing on Windows 2000 and Windows XP. The symptoms may
2345 appear to be corrupted or invalid DUN settings, or passwords.
2349 When setting up an NT based Windows system with
2350 <application>Privoxy</application> you may find that things do not seem to be
2351 doing what you expect. When you set your system up you will probably have set
2352 up Internet Connection Sharing (ICS) with Dial up Networking (DUN) when
2353 logged in with administrator privileges. You will probably have made this DUN
2354 connection available to other accounts that you may have set-up on your
2355 system. E.g. Mum or Dad sets up the system and makes accounts suitably
2356 configured for the kids.
2360 When setting up <application>Privoxy</application> in this environment you
2361 will have to alter the proxy set-up of Internet Explorer (IE) for the
2362 specific DUN connection on which you wish to use
2363 <application>Privoxy</application>. When you do this the ICS DUN set-up
2364 becomes user specific. In this instance you will see no difference if you
2365 change the DUN connection under the account used to set-up the connection.
2366 However when you do this from another user you will notice that the DUN
2367 connection changes to make available to "Me only". You will also find that
2368 you have to store the password under each different user!
2372 The reason for this is that each user's set-up for IE is user specific. Each
2373 set-up DUN connection and each LAN connection in IE store the settings for
2374 each user individually. As such this enforces individual configurations
2375 rather than common ones. Hence the first time you use a DUN connection after
2376 re-booting your system it may not perform as you expect, and prompt you for
2377 the password. Just set and save the password again and all should be OK.
2381 [Thanks to Ray Griffith for this submission.]
2386 <!-- ~~~~~ New section ~~~~~ -->
2387 <sect2 id="ftp" renderas="sect3">
2388 <title>I cannot connect to any FTP sites. Privoxy
2389 is blocking me.</title>
2391 <application>Privoxy</application> cannot act as a proxy for FTP traffic,
2392 so do not configure your browser to use <application>Privoxy</application>
2393 as an FTP proxy. The same is true for <emphasis>any protocol other than HTTP
2394 or HTTPS (SSL)</emphasis>.
2397 Most browsers understand FTP as well as HTTP. If you connect to a site, with
2398 a URL like <literal>ftp://ftp.example.com</literal>, your browser is making
2399 an FTP connection, and not a HTTP connection. So while your browser may
2400 speak FTP, <application>Privoxy</application> does not, and cannot proxy
2404 To complicate matters, some systems may have a generic <quote>proxy</quote>
2405 setting, which will enable various protocols, including
2406 <emphasis>both</emphasis> HTTP and FTP proxying! So it is possible to
2407 accidentally enable FTP proxying in these cases. And of course, if this
2408 happens, <application>Privoxy</application> will indeed cause problems since
2409 it does not know FTP. <![%p-newstuff;[Newer version will give a sane error
2410 message if a FTP connection is attempted.]]> Just disable the FTP setting
2411 and all will be well again.
2414 Will <application>Privoxy</application> ever proxy FTP traffic? Unlikely.
2415 There just is not much reason, and the work to make this happen is more than
2420 <!-- ~~~~~ New section ~~~~~ -->
2421 <sect2 id="osxie" renderas="sect3">
2422 <title>In Mac OSX, I can't configure Microsoft Internet Explorer to use
2423 Privoxy as the HTTP proxy.</title>
2425 Microsoft Internet Explorer (in versions like 5.1) respects system-wide
2426 network settings. In order to change the HTTP proxy, open System
2427 Preferences, and click on the Network icon. In the settings pane that
2428 comes up, click on the Proxies tab. Ensure the "Web Proxy (HTTP)" checkbox
2429 is checked and enter <literal>127.0.0.1</literal> in the entry field.
2430 Enter <literal>8118</literal> in the Port field. The next time you start
2431 IE, it should reflect these values.
2435 <!-- ~~~~~ New section ~~~~~ -->
2436 <sect2 renderas="sect3" id="osxuninstall">
2437 <title>In Mac OSX, I dragged the Privoxy folder to the trash in order to
2438 uninstall it. Now the finder tells me I don't have sufficient privileges to
2439 empty the trash.</title>
2441 Just dragging the <application>Privoxy</application> folder to the trash is
2442 not enough to delete it. <application>Privoxy</application> supplies an
2443 <application>uninstall.command</application> file that takes care of
2444 these details. Open the trash, drag the <application>uninstall.command</application>
2445 file out of the trash and double-click on it. You will be prompted for
2446 confirmation and the administration password.
2449 The trash may still appear full after this command; emptying the trash
2450 from the desktop should make it appear empty again.
2455 <!-- ~~~~~ New section ~~~~~ -->
2456 <sect2 renderas="sect3" id="osximages">
2457 <title>In Mac OSX Panther (10.3), images often fail to load and/or I
2458 experience random delays in page loading. I'm using
2459 <literal>localhost</literal> as my browser's proxy setting.</title>
2461 We believe this is due to an IPv6-related bug in OSX, but don't fully
2462 understand the issue yet. In any case, changing the proxy setting to
2463 <literal>127.0.0.1</literal> instead of <literal>localhost</literal>
2464 works around the problem.
2468 <!-- ~~~~~ New section ~~~~~ -->
2469 <sect2 renderas="sect3" id="blankpage">
2470 <title>I get a completely blank page at one site. <quote>View Source</quote>
2471 shows only: <markup><![CDATA[<html><body></body></html>]]></markup>. Without
2472 Privoxy the page loads fine.</title>
2474 Chances are that the site suffers from a bug in
2475 <ulink url="http://www.php.net/"><application>PHP</application></ulink>,
2476 which results in empty pages being sent if the client explicitly requests
2477 an uncompressed page, like <application>Privoxy</application> does.
2478 This bug has been fixed in PHP 4.2.3.
2481 To find out if this is in fact the source of the problem, try adding
2482 the site to a <literal>-prevent-compression</literal> section in
2483 <filename>user.action</filename>:
2486 # Make exceptions for ill-behaved sites:
2488 {-prevent-compression}
2489 .example.com</screen>
2491 If that works, you may also want to report the problem to the
2492 site's webmasters, telling them to use zlib.output_compression
2493 instead of ob_gzhandler in their PHP applications (workaround)
2494 or upgrade to PHP 4.2.3 or later (fix).
2498 <sect2 renderas="sect3" id="nohostname">
2499 <title>My logs show many <quote>Unable to get my own hostname</quote> lines.
2502 <application>Privoxy</application> tries to get the hostname of the system
2503 its running on from the IP address of the system interface it is bound to
2504 (from the <filename>config</filename> file
2505 <emphasis>listen-address</emphasis> setting). If the system cannot supply
2506 this information, <application>Privoxy</application> logs this condition.
2509 Typically, this would be considered a minor system configuration error. It is
2510 not a fatal error to <application>Privoxy</application> however, but may
2511 result in a much slower response from <application>Privoxy</application> on
2512 some platforms due to DNS timeouts.
2515 This can be caused by a problem with the local <filename>HOSTS</filename>
2516 file. If this file has been changed from the original, try reverting it to
2517 see if that helps. Make sure whatever name(s) are used for the local system,
2518 that they resolve both ways.
2522 <sect2 renderas="sect3" id="inuse">
2523 <title>When I try to launch Privoxy, I get an
2524 error message <quote>port 8118 is already in use</quote> (or similar wording).
2527 Port 8118 is <application>Privoxy's</application> default TCP
2528 <quote>listening</quote> port. Typically this message would mean that there
2529 is already one instance of <application>Privoxy</application> running, and
2530 your system is actually trying to start a second
2531 <application>Privoxy</application> on the same port, which will not work.
2532 (You can have multiple instances but they must be assigned different ports.)
2533 How and why this might happen varies from platform to platform, but you need
2534 to check your installation and start-up procedures.
2538 <sect2 renderas="sect3" id="demoronizer">
2540 Pages with UTF-8 fonts are garbled.
2543 This is caused by the <quote>demoronizer</quote> filter. You should either
2544 upgrade <application>Privoxy</application>, or at least upgrade to the most
2545 recent <filename>default.action</filename> file available from <ulink
2546 url="http://sourceforge.net/project/showfiles.php?group_id=11118">SourceForge</ulink>.
2547 Or you can simply disable the demoronizer filter.
2551 <sect2 renderas="sect3" id="demoronizer2">
2553 Why are binary files (such as images) corrupted when Privoxy
2557 This may also be caused by the <quote>demoronizer</quote> filter,
2558 in conjunction with a web server that is misreporting the content type. Binary
2559 files are exempted from <application>Privoxy's</application> filtering
2560 (unless the web server by mistake says the file is something else). Either
2561 upgrade <application>Privoxy</application>, or go to the most recent
2562 <filename>default.action</filename> file available from <ulink
2563 url="http://sourceforge.net/project/showfiles.php?group_id=11118">SourceForge</ulink>.
2567 <sect2 renderas="sect3" id="demoronizer3">
2569 What is the <quote>demoronizer</quote> and why is it there?
2572 The original demoronizer was a Perl script that cleaned up HTML pages which
2573 were created with certain Microsoft products. MS has used proprietary extensions
2574 to standardized font encodings (ISO 8859-1), which has caused problems for pages
2575 that are viewed with non-Microsoft products (and are expecting to see a
2576 standard set of fonts). The demoronizer corrected these errors so the pages
2577 displayed correctly. <application>Privoxy</application> borrowed from this
2578 script, introducing a filter based on the original demoronizer, which in turn could
2579 correct these errors on the fly.
2582 But this is only needed in some situations, and will cause serious problems in some
2586 If you are using Microsoft products, you do not need it. If you need to view
2587 pages with UTF-8 characters (such as Cyrillic or Chinese), then it will
2588 cause corruption of the fonts, and thus <emphasis>should not be on</emphasis>.
2591 On the other hand, if you use non-Microsoft products, and you occasionally
2592 notice wierd characters on pages, you might want to try it.
2596 <sect2 renderas="sect3" id="windowopen">
2598 Why do I keep seeing <quote>PrivoxyWindowOpen()</quote> in raw source code?
2601 <application>Privoxy</application> is attempting to disable malicious
2602 <ulink url="http://en.wikipedia.org/wiki/Javascript">Javascript</ulink>
2603 in this case, with the <literal>unsolicited-popups</literal>
2604 filter. <application>Privoxy</application> cannot tell very well
2605 <quote>good</quote> code snippets from <quote>bad</quote> code snippets.
2608 If you see this in HTML source, and the page displays without problems, then
2609 this is good, and likely some pop-up window was disabled. If you see this
2610 where it is causing a problem, such as a downloaded program source code file,
2611 then you should set an exception for this site or page such that the
2612 integrity of the page stays in tact by disabling all filtering.
2616 <sect2 renderas="sect3" id="dnserrors">
2618 I am getting too many DNS errors like <quote>404 No Such Domain</quote>. Why
2619 can't Privoxy do this better?
2622 There are potentially several factors here. First of all, the DNS resolution
2623 is done by the underlying operating system -- not
2624 <application>Privoxy</application> itself. <application>Privoxy</application>
2625 merely initiates the process and hands it off, and then later reports
2626 whatever the outcome was. And tries to give a coherent message if there seems
2627 to be a problem. In some cases, this might otherwise be mitigated by the
2628 browser itself which might try some work-arounds and alternate approaches (e.g
2629 adding <quote>www.</quote> to the URL). In other cases, if
2630 <application>Privoxy</application> is being chained with another proxy, this
2631 could complicate the issue, and cause undue
2632 delays and timeouts. In the case of a <quote>socks4a</quote> proxy, the socks
2633 server handles all the DNS. <application>Privoxy</application> would just be
2634 the <quote>messenger</quote> which is reporting whatever problem occurred
2635 downstream, and not the root cause of the error.
2639 In any case, newer versions include various improvements to help
2640 <application>Privoxy</application> better handle these cases.
2644 <sect2 renderas="sect3" id="allcpu">
2646 At one site Privoxy just hangs, and starts taking
2647 all CPU. Why is this?
2650 This is probably a manifestation of the <quote>100% cpu</quote> problem that
2651 occurs on pages containing many (thousands upon thousands) of blank lines. The blank lines
2652 are in the raw HTML source of the page, and the browser just ignores them. But the
2653 pattern matching in <application>Privoxy's</application> page filtering
2654 mechanism is trying to match against absurdly long strings and this becomes
2655 very CPU-intensive, taking a long, long time to complete. Until a better
2656 solution comes along, disable filtering on these pages, particularly the
2657 <literal>js-annoyances</literal> and <literal>unsolicited-popups</literal>
2662 <sect2 renderas="sect3" id="slowcrawl">
2663 <title>I just installed Privoxy, and all my
2664 browsing has slowed to a crawl. What gives? </title>
2666 This should not happen, and for the overwhelming number of users world-wide,
2667 it does not happen. I would suspect some inadvertent interaction of software
2668 components such as anti-virus software, spyware protectors, personal
2669 firewalls or similar components. Try disabling (or uninstalling) these one
2670 at a time and see if that helps.
2674 <sect2 renderas="sect3" id="preventcomp">
2675 <title>Why do my filters work on some sites but not on others? </title>
2677 It's probably due to compression. It is a common practice for web servers to
2678 send their content <quote>compressed</quote> in order to speed things up, and
2679 then let the browser <quote>uncompress</quote> them. When compiled with zlib support
2680 &my-app; can decompress content before filtering, otherwise you may want to enable
2682 url="../user-manual/actions-file.html#PREVENT-COMPRESSION">prevent-compression</ulink>.
2689 <!-- ~~~~~ New section ~~~~~ -->
2690 <sect1 id="contact"><title>Contacting the developers, Bug Reporting and Feature Requests</title>
2691 <!-- Include contacting.sgml -->
2693 <!-- end contacting -->
2696 <!-- ~~~~~ New section ~~~~~ -->
2697 <sect1 id="copyright"><title>Privoxy Copyright, License and History</title>
2699 <!-- Include copyright.sgml -->
2705 Portions of this document are <quote>borrowed</quote> from the original
2706 <application>Junkbuster</application> (tm) FAQ, and modified as
2707 appropriate for <application>Privoxy</application>.
2710 <!-- ~~~~~ New section ~~~~~ -->
2711 <sect2><title>License</title>
2712 <!-- Include copyright.sgml: -->
2714 <!-- end copyright -->
2716 <!-- ~ End section ~ -->
2718 <!-- ~~~~~ New section ~~~~~ -->
2719 <sect2><title>History</title>
2720 <!-- Include history.sgml -->
2726 <!-- ~ End section ~ -->
2729 <!-- ~~~~~ New section ~~~~~ -->
2731 <sect1 id="seealso"><title>See also</title>
2733 <!-- Include seealso.sgml -->
2744 Tue 09/11/01 06:38:14 PM EST: Test SGML doc by Hal Burgiss.
2746 This program is free software; you can redistribute it
2747 and/or modify it under the terms of the GNU General
2748 Public License as published by the Free Software
2749 Foundation; either version 2 of the License, or (at
2750 your option) any later version.
2752 This program is distributed in the hope that it will
2753 be useful, but WITHOUT ANY WARRANTY; without even the
2754 implied warranty of MERCHANTABILITY or FITNESS FOR A
2755 PARTICULAR PURPOSE. See the GNU General Public
2756 License for more details.
2758 The GNU General Public License should be included with
2759 this file. If not, you can view it at
2760 http://www.gnu.org/copyleft/gpl.html
2761 or write to the Free Software Foundation, Inc.,
2762 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
2765 Revision 2.30 2007/11/04 15:16:40 hal9
2768 Revision 2.29 2007/11/04 15:12:47 hal9
2769 Various minor adjustments.
2771 Revision 2.28 2007/10/27 15:14:16 fabiankeil
2772 Change Tor links to use the new domain torproject.org.
2774 Revision 2.27 2007/10/22 19:47:05 fabiankeil
2775 - Bump version and copyright.
2776 - Adjust Tor section to make it clear that forward exceptions
2777 aren't required and may not even be desired.
2778 - A bunch of other minor rewordings.
2779 - Fix markup problems Roland noticed (hopefully without adding new ones).
2781 Revision 2.26 2007/08/05 15:37:55 fabiankeil
2782 - Don't claim that thousands of people read our code.
2783 - Specify the GPL version and link to GPLv2 instead of v3.
2784 - Note that configuration syntax may change between releases.
2785 - Mention zlib support.
2786 - Answer the "transparent proxy" question properly.
2787 - Add "intercepting proxy" entry.
2789 - Rephrase some other sentences for various reasons.
2791 Revision 2.25 2007/07/18 11:00:34 hal9
2792 Add misc note about valid mark-up in Privoxy.
2794 Revision 2.24 2006/11/14 01:57:46 hal9
2795 Dump all docs prior to 3.0.6 release. Various minor changes to faq and user
2798 Revision 2.23 2006/10/21 22:19:52 hal9
2799 Two new FAQs, a rewrite or two, and some touch ups.
2801 Revision 2.22 2006/10/14 20:33:10 hal9
2802 Three new FAQ's re: templates and blocking, and various minor touch-ups/improvements.
2804 Revision 2.21 2006/10/03 14:40:51 fabiankeil
2805 Added links from the Tor faq to the
2806 configuration chapter in the User Manual.
2808 Revision 2.20 2006/09/26 10:12:37 fabiankeil
2811 Revision 2.19 2006/09/22 10:54:32 hal9
2812 Change references to 3.0.4 to 3.0.5 and minor adjustments.
2814 Revision 2.18 2006/09/22 01:27:55 hal9
2815 Final commit of probably various minor changes here and there. Unless
2816 something changes this should be ready for pending release.
2818 Revision 2.17 2006/09/17 14:56:32 hal9
2819 This includes yet several more new FAQs, some improved wording, enhanced
2820 mark-up, various hyper links to wikipedia to explain key terminology to the
2821 uninitiated, etc. This is ready for release IMO pending final tagging of cvs
2822 and Privoxy version stamping.
2824 Revision 2.16 2006/09/10 15:30:46 hal9
2827 Revision 2.15 2006/09/08 23:05:07 hal9
2828 Fix broken links. Add faq on hosts files. Move most of new windows service
2829 feature to user manual and reference in faq. Various other small changes.
2831 Revision 2.14 2006/09/05 13:25:12 david__schmidt
2832 Add Windows service invocation stuff (duplicated) in FAQ and in user manual under Windows startup. One probably ought to reference the other.
2834 Revision 2.13 2006/09/04 19:20:33 fabiankeil
2835 Adjusted anonymity related sections to match reality.
2836 Added a section about using Privoxy with Tor.
2838 Revision 2.12 2006/09/03 14:15:30 hal9
2839 Various updates, including 7 or 8 new FAQs, and updates/changes to various
2840 other ones to better reflect improvements, additions and changes for the
2841 upcoming release. This is close to final form for 3.0.4 IMHO.
2843 Revision 2.11 2006/07/18 14:48:50 david__schmidt
2844 Reorganizing the repository: swapping out what was HEAD (the old 3.1 branch)
2845 with what was really the latest development (the v_3_0_branch branch)
2847 Revision 1.61.2.41 2004/04/05 13:44:05 oes
2848 Fixed allow-all-cookies alias name; closes SR #929746
2850 Revision 1.61.2.40 2004/01/30 17:00:33 oes
2851 Added OSX Panther problem
2853 Revision 1.61.2.39 2004/01/29 22:53:08 hal9
2854 Minor changes for exempting docs of text/plain. Change copyright date.
2856 Revision 1.61.2.38 2003/12/10 03:39:45 hal9
2857 Added FAQs for: demoronizer, related problems and why its included. Also,
2858 port 8118 already in use questions, and PrivoxyWindowOpen() questions. All in
2859 troubleshooting section.
2861 Revision 1.61.2.37 2003/10/17 11:01:50 oes
2862 Added Q&A for "not being used" page problem
2864 Revision 1.61.2.36 2003/06/26 23:49:20 hal9
2865 More on the filter/source code problem.
2867 Revision 1.61.2.35 2003/06/26 13:38:08 hal9
2868 Add FAQ on whether configuring Privoxy is necessary or not.
2870 Revision 1.61.2.34 2003/06/26 03:00:03 hal9
2871 Sorry, found another copyright date.
2873 Revision 1.61.2.33 2003/06/26 02:57:05 hal9
2874 Fix typo (finally!) and very minor modifications.
2876 Revision 1.61.2.32 2003/06/26 02:52:04 hal9
2879 Revision 1.61.2.31 2003/06/25 01:27:51 hal9
2880 Fix copyright, and a few nits.
2882 Revision 1.61.2.30 2003/06/25 01:13:52 hal9
2885 - FAQ on "Unable to get my own hostname"
2886 - Another one on filtering effects on text files.
2888 Revision 1.61.2.29 2003/06/15 21:32:58 hal9
2889 Add to the 4.17 (filtering effects on downloaded files).
2891 Revision 1.61.2.28 2003/03/18 19:37:21 oes
2892 s/Advanced|Radical/Adventuresome/g to avoid complaints re fun filter
2894 Revision 1.61.2.27 2002/12/01 06:31:58 hal9
2895 Add faq on win32 error 503 due to ZoneAlarm.
2897 Revision 1.61.2.26 2002/11/17 06:41:06 hal9
2898 Move default profiles table from FAQ to U-M, and other minor related changes.
2901 Revision 1.61.2.25 2002/10/29 03:21:50 hal9
2902 Add 3 Q/A's relating to HTML in email. Other minor touchups.
2904 Revision 1.61.2.24 2002/10/15 12:50:22 oes
2905 s/Advanced/Radical/ (stupid me)
2907 Revision 1.61.2.23 2002/10/15 12:38:56 oes
2908 Added Microsuck faq; more detail for PHP problem
2910 Revision 1.61.2.22 2002/10/12 01:13:13 hal9
2911 Updates for demoronizer, more commentary on Radical profile, and update on
2912 the srvany.exe/icon fix.
2914 Revision 1.61.2.21 2002/10/10 04:09:35 hal9
2915 s/Advanced/Radical/ and added very brief note.
2917 Revision 1.61.2.20 2002/09/26 01:22:45 hal9
2918 Small additions for LAN setup, content-cookies/SSL, and FTP non-support.
2920 Revision 1.61.2.19 2002/08/25 23:31:56 hal9
2921 Fix one grammatical error. Add brief FAQ relating to tranparent proxies (ie
2922 port 80 setting). Add FAQ on effects of Privoxy on downloaded files
2923 (especially filtering).
2925 Revision 1.61.2.18 2002/08/14 16:39:37 hal9
2926 Fix wrong tag on FAQ addition.
2928 Revision 1.61.2.17 2002/08/14 00:01:18 hal9
2931 Revision 1.61.2.16 2002/08/13 00:10:38 hal9
2932 Add faq to troubleshooting re: blank page syndrome, ie {-prevent-compression}.
2934 Revision 1.61.2.15 2002/08/10 11:34:22 oes
2935 Add disclaimer about probably being out-of-date
2937 Revision 1.61.2.14 2002/08/07 02:53:43 hal9
2938 Fix some minor markup errors, and move one OSX Q/A to troubleshooting section.
2940 Revision 1.61.2.13 2002/08/06 11:55:32 oes
2941 Added missing close tag
2943 Revision 1.61.2.12 2002/08/06 11:43:46 david__schmidt
2944 Updated OSX uninstall FAQ... we have an uninstall script now.
2946 Revision 1.61.2.11 2002/08/06 08:54:03 oes
2947 Style police: Fixed formatting details
2949 Revision 1.61.2.10 2002/08/02 14:00:25 david__schmidt
2950 Made the OSX removal commands far less dangerous
2952 Revision 1.61.2.9 2002/08/02 13:14:45 oes
2953 Added warning about sudo rm -r for Mac OSX deinstallation; moved this item to install section
2955 Revision 1.61.2.8 2002/08/02 02:01:42 david__schmidt
2956 Add FAQ item for MSIE on OSX HTTP proxy confusion
2958 Revision 1.61.2.7 2002/08/02 01:46:01 david__schmidt
2959 Added FAQ item for Mac OSX uninstall woes
2961 Revision 1.61.2.6 2002/07/30 20:04:56 hal9
2962 Fix typo: 'schould'.
2964 Revision 1.61.2.5 2002/07/26 15:22:58 oes
2965 - Updated to reflect changes in standard.action
2966 - Added info on where to get updated actions files
2968 Revision 1.61.2.4 2002/07/25 21:42:29 hal9
2969 Add brief notes on not proxying non-HTTP protocols.
2971 Revision 1.61.2.3 2002/06/09 16:36:33 hal9
2972 Clarifications on filtering and MIME. Hardcode 'latest release' in index.html.
2974 Revision 1.61.2.2 2002/06/06 02:51:34 hal9
2975 Fix typo in URL http:/config.privoxy.org
2977 Revision 1.61.2.1 2002/06/05 23:10:43 hal9
2978 Add new FAQ re: DUN/IE. Change release date from May to June :)
2980 Revision 1.61 2002/05/25 12:37:25 hal9
2981 Various minor changes and edits.
2983 Revision 1.60 2002/05/22 17:17:48 oes
2984 Proofread & added more links into u-m
2986 Revision 1.59 2002/05/15 04:03:30 hal9
2987 Fix ulink -> link markup.
2989 Revision 1.58 2002/05/10 01:48:20 hal9
2990 This is mostly proposed copyright/licensing additions and changes. Docs
2991 are still GPL, but licensing and copyright are more visible. Also, copyright
2992 changed in doc header comments (eliminate references to JB except FAQ).
2994 Revision 1.57 2002/05/05 20:26:02 hal9
2995 Sorting out license vs copyright in these docs.
2997 Revision 1.56 2002/05/04 08:44:44 swa
3000 Revision 1.55 2002/05/04 00:41:56 hal9
3001 -Remove TOC/first page kludge in favor of proper handling via dsl file.
3003 Revision 1.54 2002/05/03 05:06:44 hal9
3004 Add brief Q/A on transparent proxies.
3006 Revision 1.53 2002/05/03 01:34:52 hal9
3007 Fix section numbering for new sections (due to TOC kludge).
3009 Revision 1.52 2002/04/29 03:08:43 hal9
3010 -Added new Q/A on new actions file set up (pointer to u-m)
3011 -Fixed a few broken links and converted old actions as a result of
3014 Revision 1.51 2002/04/26 17:24:31 swa
3015 bookmarks cleaned, changed structure of user manual, screen and programlisting cleanups, and numerous other changes that I forgot
3017 Revision 1.50 2002/04/26 05:25:23 hal9
3018 Mass commit to catch a few scattered fixes.
3020 Revision 1.49 2002/04/12 10:10:18 swa
3023 Revision 1.48 2002/04/10 18:45:15 swa
3026 Revision 1.47 2002/04/10 04:05:32 hal9
3029 Revision 1.45 2002/04/08 22:59:26 hal9
3030 Version update. Spell chkconfig correctly :)
3032 Revision 1.44 2002/04/07 21:24:29 hal9
3033 Touch up on name change.
3035 Revision 1.43 2002/04/04 21:59:53 hal9
3036 Added NT/W2K service/icon situation.
3038 Revision 1.42 2002/04/04 18:46:47 swa
3039 consistent look. reuse of copyright, history et. al.
3041 Revision 1.41 2002/04/04 06:48:37 hal9
3042 Structural changes to allow for conditional inclusion/exclusion of content
3043 based on entity toggles, e.g. 'entity % p-not-stable "INCLUDE"'. And
3044 definition of internal entities, e.g. 'entity p-version "2.9.13"' that will
3045 eventually be set by Makefile.
3046 More boilerplate text for use across multiple docs.
3048 Revision 1.40 2002/04/03 04:22:03 hal9
3049 Fixed several typos.
3051 Revision 1.39 2002/04/03 03:53:03 hal9
3052 Revert some changes, and then make some news, to layout, and appearance.
3054 Revision 1.38 2002/04/02 03:49:10 hal9
3055 Major changes to doc structure and layout. Sections are not automatically
3056 numbered now. TOC is on page by itself.
3058 Revision 1.37 2002/04/01 16:24:07 hal9
3059 -Rework of supported Q/A.
3060 -Set up entities to include boilerplate text.
3062 Revision 1.36 2002/03/31 23:18:47 hal9
3063 More on dealing with BLOCKED.
3065 Revision 1.35 2002/03/30 04:14:19 hal9
3066 Fix privoxy.org/config links.
3068 Revision 1.34 2002/03/29 04:35:56 hal9
3071 Revision 1.33 2002/03/29 01:31:48 hal9
3072 Several new Q/A's and other touch ups.
3074 Revision 1.32 2002/03/27 00:57:03 hal9
3075 Touch ups for name change.
3077 Revision 1.31 2002/03/26 22:29:55 swa
3078 we have a new homepage!
3080 Revision 1.30 2002/03/25 16:39:22 hal9
3081 A few new sections. Made all links relative to user-manual.
3083 Revision 1.29 2002/03/25 05:23:57 hal9
3084 Moved section, and touch ups.
3086 Revision 1.28 2002/03/25 04:27:33 hal9
3087 New section related to name change.
3089 Revision 1.25 2002/03/24 16:08:08 swa
3090 we are too lazy to make a block-built
3091 privoxy logo. hence removed the option.
3093 Revision 1.24 2002/03/24 15:46:20 swa
3094 name change related issue.
3096 Revision 1.23 2002/03/24 12:33:01 swa
3099 Revision 1.22 2002/03/24 11:51:00 swa
3100 name change. changed filenames.
3102 Revision 1.21 2002/03/24 11:01:06 swa
3105 Revision 1.20 2002/03/23 15:13:11 swa
3106 renamed every reference to the old name with foobar.
3107 fixed "application foobar application" tag, fixed
3108 "the foobar" with "foobar". left junkbustser in cvs
3109 comments and remarks to history untouched.
3111 Revision 1.19 2002/03/21 17:01:54 hal9
3114 Revision 1.18 2002/03/18 16:40:31 hal9
3117 Revision 1.17 2002/03/18 03:53:53 hal9
3120 Revision 1.16 2002/03/17 21:32:56 hal9
3121 A few more additions.
3123 Revision 1.15 2002/03/17 07:25:59 hal9
3124 Correcting some of my typos, and some additions.
3126 Revision 1.14 2002/03/17 02:39:13 hal9
3127 A little more added ...
3129 Revision 1.13 2002/03/17 00:22:20 hal9
3130 Adding new stuff, and trying to incorporate stuff from old faq.
3132 Revision 1.12 2002/03/11 20:13:21 swa
3135 Revision 1.11 2002/03/11 18:42:27 swa
3138 Revision 1.10 2002/03/11 13:13:27 swa
3139 correct feedback channels
3141 Revision 1.9 2002/03/10 23:34:04 swa
3142 more info on not hiding ip address
3144 Revision 1.8 2002/03/09 15:55:48 swa
3145 added default config section
3147 Revision 1.7 2002/03/07 18:16:55 swa
3150 Revision 1.6 2002/03/07 13:16:31 oes
3151 Committing changes by Stefan
3153 Revision 1.5 2002/03/02 15:50:04 swa
3154 2.9.11 version. more input for docs.
3156 Revision 1.4 2002/02/24 14:34:24 jongfoster
3157 Formatting changes. Now changing the doctype to DocBook XML 4.1
3158 will work - no other changes are needed.
3160 Revision 1.3 2001/09/23 10:13:48 swa
3161 upload process established. run make webserver and
3162 the documentation is moved to the webserver. documents
3163 are now linked correctly.
3165 Revision 1.2 2001/09/13 15:20:17 swa
3166 merged standards into developer manual
3168 Revision 1.1 2001/09/12 15:36:41 swa
3169 source files for junkbuster documentation
3171 Revision 1.3 2001/09/10 17:43:59 swa
3172 first proposal of a structure.
3174 Revision 1.2 2001/06/13 14:28:31 swa
3175 docs should have an author.
3177 Revision 1.1 2001/06/13 14:20:37 swa
3178 first import of project's documentation for the webserver.
projects / privoxy.git / blob