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41 <h1 class="SECT1"><a name="ACTIONS-FILE" id="ACTIONS-FILE">8. Actions
44 <p>The actions files are used to define what <span class=
45 "emphasis"><i class="EMPHASIS">actions</i></span> <span class=
46 "APPLICATION">Privoxy</span> takes for which URLs, and thus determines
47 how ad images, cookies and various other aspects of HTTP content and
48 transactions are handled, and on which sites (or even parts thereof).
49 There are a number of such actions, with a wide range of functionality.
50 Each action does something a little different. These actions give us a
51 veritable arsenal of tools with which to exert our control, preferences
52 and independence. Actions can be combined so that their effects are
53 aggregated when applied against a given set of URLs.</p>
55 <p>There are three action files included with <span class=
56 "APPLICATION">Privoxy</span> with differing purposes:</p>
60 <p><tt class="FILENAME">match-all.action</tt> - is used to define
61 which <span class="QUOTE">"actions"</span> relating to
62 banner-blocking, images, pop-ups, content modification, cookie
63 handling etc should be applied by default. It should be the first
64 actions file loaded</p>
68 <p><tt class="FILENAME">default.action</tt> - defines many exceptions
69 (both positive and negative) from the default set of actions that's
70 configured in <tt class="FILENAME">match-all.action</tt>. It is a set
71 of rules that should work reasonably well as-is for most users. This
72 file is only supposed to be edited by the developers. It should be
73 the second actions file loaded.</p>
77 <p><tt class="FILENAME">user.action</tt> - is intended to be for
78 local site preferences and exceptions. As an example, if your ISP or
79 your bank has specific requirements, and need special handling, this
80 kind of thing should go here. This file will not be upgraded.</p>
84 <p><span class="GUIBUTTON">Edit</span> <span class="GUIBUTTON">Set to
85 Cautious</span> <span class="GUIBUTTON">Set to Medium</span>
86 <span class="GUIBUTTON">Set to Advanced</span></p>
88 <p>These have increasing levels of aggressiveness <span class=
89 "emphasis"><i class="EMPHASIS">and have no influence on your browsing
90 unless you select them explicitly in the editor</i></span>. A default
91 installation should be pre-set to <tt class="LITERAL">Cautious</tt>.
92 New users should try this for a while before adjusting the settings
93 to more aggressive levels. The more aggressive the settings, then the
94 more likelihood there is of problems such as sites not working as
97 <p>The <span class="GUIBUTTON">Edit</span> button allows you to turn
98 each action on/off individually for fine-tuning. The <span class=
99 "GUIBUTTON">Cautious</span> button changes the actions list to
100 low/safe settings which will activate ad blocking and a minimal set
101 of <span class="APPLICATION">Privoxy</span>'s features, and
102 subsequently there will be less of a chance for accidental problems.
103 The <span class="GUIBUTTON">Medium</span> button sets the list to a
104 medium level of other features and a low level set of privacy
105 features. The <span class="GUIBUTTON">Advanced</span> button sets the
106 list to a high level of ad blocking and medium level of privacy. See
107 the chart below. The latter three buttons over-ride any changes via
108 with the <span class="GUIBUTTON">Edit</span> button. More fine-tuning
109 can be done in the lower sections of this internal page.</p>
111 <p>While the actions file editor allows to enable these settings in
112 all actions files, they are only supposed to be enabled in the first
113 one to make sure you don't unintentionally overrule earlier
116 <p>The default profiles, and their associated actions, as pre-defined
117 in <tt class="FILENAME">default.action</tt> are:</p>
120 <a name="AEN2618" id="AEN2618"></a>
122 <p><b>Table 1. Default Configurations</b></p>
124 <table border="1" frame="border" rules="all" class="CALSTABLE">
125 <col width="1*" title="C1">
126 <col width="1*" title="C2">
127 <col width="1*" title="C3">
128 <col width="1*" title="C4">
144 <td>Ad-blocking Aggressiveness</td>
154 <td>Ad-filtering by size</td>
164 <td>Ad-filtering by link</td>
174 <td>Pop-up killing</td>
184 <td>Privacy Features</td>
194 <td>Cookie handling</td>
198 <td>session-only</td>
204 <td>Referer forging</td>
214 <td>GIF de-animation</td>
224 <td>Fast redirects</td>
244 <td>JavaScript taming</td>
254 <td>Web-bug killing</td>
264 <td>Image tag reordering</td>
278 <p>The list of actions files to be used are defined in the main
279 configuration file, and are processed in the order they are defined (e.g.
280 <tt class="FILENAME">default.action</tt> is typically processed before
281 <tt class="FILENAME">user.action</tt>). The content of these can all be
282 viewed and edited from <a href="http://config.privoxy.org/show-status"
283 target="_top">http://config.privoxy.org/show-status</a>. The over-riding
284 principle when applying actions, is that the last action that matches a
285 given URL wins. The broadest, most general rules go first (defined in
286 <tt class="FILENAME">default.action</tt>), followed by any exceptions
287 (typically also in <tt class="FILENAME">default.action</tt>), which are
288 then followed lastly by any local preferences (typically in <span class=
289 "emphasis"><i class="EMPHASIS">user</i></span><tt class=
290 "FILENAME">.action</tt>). Generally, <tt class=
291 "FILENAME">user.action</tt> has the last word.</p>
293 <p>An actions file typically has multiple sections. If you want to use
294 <span class="QUOTE">"aliases"</span> in an actions file, you have to
295 place the (optional) <a href="actions-file.html#ALIASES">alias
296 section</a> at the top of that file. Then comes the default set of rules
297 which will apply universally to all sites and pages (be <span class=
298 "emphasis"><i class="EMPHASIS">very careful</i></span> with using such a
299 universal set in <tt class="FILENAME">user.action</tt> or any other
300 actions file after <tt class="FILENAME">default.action</tt>, because it
301 will override the result from consulting any previous file). And then
302 below that, exceptions to the defined universal policies. You can regard
303 <tt class="FILENAME">user.action</tt> as an appendix to <tt class=
304 "FILENAME">default.action</tt>, with the advantage that it is a separate
305 file, which makes preserving your personal settings across <span class=
306 "APPLICATION">Privoxy</span> upgrades easier.</p>
308 <p>Actions can be used to block anything you want, including ads,
309 banners, or just some obnoxious URL whose content you would rather not
310 see. Cookies can be accepted or rejected, or accepted only during the
311 current browser session (i.e. not written to disk), content can be
312 modified, some JavaScripts tamed, user-tracking fooled, and much more.
313 See below for a <a href="actions-file.html#ACTIONS">complete list of
317 <h2 class="SECT2"><a name="RIGHT-MIX" id="RIGHT-MIX">8.1. Finding the
320 <p>Note that some <a href="actions-file.html#ACTIONS">actions</a>, like
321 cookie suppression or script disabling, may render some sites unusable
322 that rely on these techniques to work properly. Finding the right mix
323 of actions is not always easy and certainly a matter of personal taste.
324 And, things can always change, requiring refinements in the
325 configuration. In general, it can be said that the more <span class=
326 "QUOTE">"aggressive"</span> your default settings (in the top section
327 of the actions file) are, the more exceptions for <span class=
328 "QUOTE">"trusted"</span> sites you will have to make later. If, for
329 example, you want to crunch all cookies per default, you'll have to
330 make exceptions from that rule for sites that you regularly use and
331 that require cookies for actually useful purposes, like maybe your
332 bank, favorite shop, or newspaper.</p>
334 <p>We have tried to provide you with reasonable rules to start from in
335 the distribution actions files. But there is no general rule of thumb
336 on these things. There just are too many variables, and sites are
337 constantly changing. Sooner or later you will want to change the rules
338 (and read this chapter again :).</p>
342 <h2 class="SECT2"><a name="HOW-TO-EDIT" id="HOW-TO-EDIT">8.2. How to
345 <p>The easiest way to edit the actions files is with a browser by using
346 our browser-based editor, which can be reached from <a href=
347 "http://config.privoxy.org/show-status" target=
348 "_top">http://config.privoxy.org/show-status</a>. Note: the config file
350 "config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</a> must be
351 enabled for this to work. The editor allows both fine-grained control
352 over every single feature on a per-URL basis, and easy choosing from
353 wholesale sets of defaults like <span class="QUOTE">"Cautious"</span>,
354 <span class="QUOTE">"Medium"</span> or <span class=
355 "QUOTE">"Advanced"</span>. Warning: the <span class=
356 "QUOTE">"Advanced"</span> setting is more aggressive, and will be more
357 likely to cause problems for some sites. Experienced users only!</p>
359 <p>If you prefer plain text editing to GUIs, you can of course also
360 directly edit the the actions files with your favorite text editor.
361 Look at <tt class="FILENAME">default.action</tt> which is richly
362 commented with many good examples.</p>
366 <h2 class="SECT2"><a name="ACTIONS-APPLY" id="ACTIONS-APPLY">8.3. How
367 Actions are Applied to Requests</a></h2>
369 <p>Actions files are divided into sections. There are special sections,
370 like the <span class="QUOTE">"<a href=
371 "actions-file.html#ALIASES">alias</a>"</span> sections which will be
372 discussed later. For now let's concentrate on regular sections: They
373 have a heading line (often split up to multiple lines for readability)
374 which consist of a list of actions, separated by whitespace and
375 enclosed in curly braces. Below that, there is a list of URL and tag
376 patterns, each on a separate line.</p>
378 <p>To determine which actions apply to a request, the URL of the
379 request is compared to all URL patterns in each <span class=
380 "QUOTE">"action file"</span>. Every time it matches, the list of
381 applicable actions for the request is incrementally updated, using the
382 heading of the section in which the pattern is located. The same is
383 done again for tags and tag patterns later on.</p>
385 <p>If multiple applying sections set the same action differently, the
386 last match wins. If not, the effects are aggregated. E.g. a URL might
387 match a regular section with a heading line of <tt class="LITERAL">{
388 +<a href="actions-file.html#HANDLE-AS-IMAGE">handle-as-image</a>
389 }</tt>, then later another one with just <tt class="LITERAL">{
390 +<a href="actions-file.html#BLOCK">block</a> }</tt>, resulting in
391 <span class="emphasis"><i class="EMPHASIS">both</i></span> actions to
392 apply. And there may well be cases where you will want to combine
393 actions together. Such a section then might look like:</p>
395 <table border="0" bgcolor="#E0E0E0" width="100%">
399 { +<tt class="LITERAL">handle-as-image</tt> +<tt class=
400 "LITERAL">block{Banner ads.}</tt> }
401 # Block these as if they were images. Send no block page.
403 media.example.com/.*banners
404 .example.com/images/ads/
410 <p>You can trace this process for URL patterns and any given URL by
411 visiting <a href="http://config.privoxy.org/show-url-info" target=
412 "_top">http://config.privoxy.org/show-url-info</a>.</p>
414 <p>Examples and more detail on this is provided in the Appendix,
415 <a href="appendix.html#ACTIONSANAT">Troubleshooting: Anatomy of an
416 Action</a> section.</p>
420 <h2 class="SECT2"><a name="AF-PATTERNS" id="AF-PATTERNS">8.4.
423 <p>As mentioned, <span class="APPLICATION">Privoxy</span> uses
424 <span class="QUOTE">"patterns"</span> to determine what <span class=
425 "emphasis"><i class="EMPHASIS">actions</i></span> might apply to which
426 sites and pages your browser attempts to access. These <span class=
427 "QUOTE">"patterns"</span> use wild card type <span class=
428 "emphasis"><i class="EMPHASIS">pattern</i></span> matching to achieve a
429 high degree of flexibility. This allows one expression to be expanded
430 and potentially match against many similar patterns.</p>
432 <p>Generally, an URL pattern has the form <tt class=
433 "LITERAL"><host><port>/<path></tt>, where the
434 <tt class="LITERAL"><host></tt>, the <tt class=
435 "LITERAL"><port></tt> and the <tt class=
436 "LITERAL"><path></tt> are optional. (This is why the special
437 <tt class="LITERAL">/</tt> pattern matches all URLs). Note that the
438 protocol portion of the URL pattern (e.g. <tt class=
439 "LITERAL">http://</tt>) should <span class="emphasis"><i class=
440 "EMPHASIS">not</i></span> be included in the pattern. This is assumed
443 <p>The pattern matching syntax is different for the host and path parts
444 of the URL. The host part uses a simple globbing type matching
445 technique, while the path part uses more flexible <a href=
446 "http://en.wikipedia.org/wiki/Regular_expressions" target=
447 "_top"><span class="QUOTE">"Regular Expressions"</span></a> (POSIX
450 <p>The port part of a pattern is a decimal port number preceded by a
451 colon (<tt class="LITERAL">:</tt>). If the host part contains a
452 numerical IPv6 address, it has to be put into angle brackets
453 (<tt class="LITERAL"><</tt>, <tt class="LITERAL">></tt>).</p>
455 <div class="VARIABLELIST">
457 <dt><tt class="LITERAL">www.example.com/</tt></dt>
460 <p>is a host-only pattern and will match any request to
461 <tt class="LITERAL">www.example.com</tt>, regardless of which
462 document on that server is requested. So ALL pages in this domain
463 would be covered by the scope of this action. Note that a simple
464 <tt class="LITERAL">example.com</tt> is different and would NOT
468 <dt><tt class="LITERAL">www.example.com</tt></dt>
471 <p>means exactly the same. For host-only patterns, the trailing
472 <tt class="LITERAL">/</tt> may be omitted.</p>
475 <dt><tt class="LITERAL">www.example.com/index.html</tt></dt>
478 <p>matches all the documents on <tt class=
479 "LITERAL">www.example.com</tt> whose name starts with <tt class=
480 "LITERAL">/index.html</tt>.</p>
483 <dt><tt class="LITERAL">www.example.com/index.html$</tt></dt>
486 <p>matches only the single document <tt class=
487 "LITERAL">/index.html</tt> on <tt class=
488 "LITERAL">www.example.com</tt>.</p>
491 <dt><tt class="LITERAL">/index.html$</tt></dt>
494 <p>matches the document <tt class="LITERAL">/index.html</tt>,
495 regardless of the domain, i.e. on <span class=
496 "emphasis"><i class="EMPHASIS">any</i></span> web server
500 <dt><tt class="LITERAL">/</tt></dt>
503 <p>Matches any URL because there's no requirement for either the
504 domain or the path to match anything.</p>
507 <dt><tt class="LITERAL">:8000/</tt></dt>
510 <p>Matches any URL pointing to TCP port 8000.</p>
513 <dt><tt class="LITERAL">10.0.0.1/</tt></dt>
516 <p>Matches any URL with the host address <tt class=
517 "LITERAL">10.0.0.1</tt>. (Note that the real URL uses plain
518 brackets, not angle brackets.)</p>
521 <dt><tt class="LITERAL"><2001:db8::1>/</tt></dt>
524 <p>Matches any URL with the host address <tt class=
525 "LITERAL">2001:db8::1</tt>. (Note that the real URL uses plain
526 brackets, not angle brackets.)</p>
529 <dt><tt class="LITERAL">index.html</tt></dt>
532 <p>matches nothing, since it would be interpreted as a domain
533 name and there is no top-level domain called <tt class=
534 "LITERAL">.html</tt>. So its a mistake.</p>
540 <h3 class="SECT3"><a name="HOST-PATTERN" id="HOST-PATTERN">8.4.1. The
541 Host Pattern</a></h3>
543 <p>The matching of the host part offers some flexible options: if the
544 host pattern starts or ends with a dot, it becomes unanchored at that
545 end. The host pattern is often referred to as domain pattern as it is
546 usually used to match domain names and not IP addresses. For
549 <div class="VARIABLELIST">
551 <dt><tt class="LITERAL">.example.com</tt></dt>
554 <p>matches any domain with first-level domain <tt class=
555 "LITERAL">com</tt> and second-level domain <tt class=
556 "LITERAL">example</tt>. For example <tt class=
557 "LITERAL">www.example.com</tt>, <tt class=
558 "LITERAL">example.com</tt> and <tt class=
559 "LITERAL">foo.bar.baz.example.com</tt>. Note that it wouldn't
560 match if the second-level domain was <tt class=
561 "LITERAL">another-example</tt>.</p>
564 <dt><tt class="LITERAL">www.</tt></dt>
567 <p>matches any domain that <span class="emphasis"><i class=
568 "EMPHASIS">STARTS</i></span> with <tt class="LITERAL">www.</tt>
569 (It also matches the domain <tt class="LITERAL">www</tt> but
570 most of the time that doesn't matter.)</p>
573 <dt><tt class="LITERAL">.example.</tt></dt>
576 <p>matches any domain that <span class="emphasis"><i class=
577 "EMPHASIS">CONTAINS</i></span> <tt class=
578 "LITERAL">.example.</tt>. And, by the way, also included would
579 be any files or documents that exist within that domain since
580 no path limitations are specified. (Correctly speaking: It
581 matches any FQDN that contains <tt class="LITERAL">example</tt>
582 as a domain.) This might be <tt class=
583 "LITERAL">www.example.com</tt>, <tt class=
584 "LITERAL">news.example.de</tt>, or <tt class=
585 "LITERAL">www.example.net/cgi/testing.pl</tt> for instance. All
586 these cases are matched.</p>
591 <p>Additionally, there are wild-cards that you can use in the domain
592 names themselves. These work similarly to shell globbing type
593 wild-cards: <span class="QUOTE">"*"</span> represents zero or more
594 arbitrary characters (this is equivalent to the <a href=
595 "http://en.wikipedia.org/wiki/Regular_expressions" target=
596 "_top"><span class="QUOTE">"Regular Expression"</span></a> based
597 syntax of <span class="QUOTE">".*"</span>), <span class=
598 "QUOTE">"?"</span> represents any single character (this is
599 equivalent to the regular expression syntax of a simple <span class=
600 "QUOTE">"."</span>), and you can define <span class=
601 "QUOTE">"character classes"</span> in square brackets which is
602 similar to the same regular expression technique. All of this can be
605 <div class="VARIABLELIST">
607 <dt><tt class="LITERAL">ad*.example.com</tt></dt>
610 <p>matches <span class="QUOTE">"adserver.example.com"</span>,
611 <span class="QUOTE">"ads.example.com"</span>, etc but not
612 <span class="QUOTE">"sfads.example.com"</span></p>
615 <dt><tt class="LITERAL">*ad*.example.com</tt></dt>
618 <p>matches all of the above, and then some.</p>
621 <dt><tt class="LITERAL">.?pix.com</tt></dt>
624 <p>matches <tt class="LITERAL">www.ipix.com</tt>, <tt class=
625 "LITERAL">pictures.epix.com</tt>, <tt class=
626 "LITERAL">a.b.c.d.e.upix.com</tt> etc.</p>
629 <dt><tt class="LITERAL">www[1-9a-ez].example.c*</tt></dt>
632 <p>matches <tt class="LITERAL">www1.example.com</tt>,
633 <tt class="LITERAL">www4.example.cc</tt>, <tt class=
634 "LITERAL">wwwd.example.cy</tt>, <tt class=
635 "LITERAL">wwwz.example.com</tt> etc., but <span class=
636 "emphasis"><i class="EMPHASIS">not</i></span> <tt class=
637 "LITERAL">wwww.example.com</tt>.</p>
642 <p>While flexible, this is not the sophistication of full regular
643 expression based syntax.</p>
647 <h3 class="SECT3"><a name="PATH-PATTERN" id="PATH-PATTERN">8.4.2. The
648 Path Pattern</a></h3>
650 <p><span class="APPLICATION">Privoxy</span> uses <span class=
651 "QUOTE">"modern"</span> POSIX 1003.2 <a href=
652 "http://en.wikipedia.org/wiki/Regular_expressions" target=
653 "_top"><span class="QUOTE">"Regular Expressions"</span></a> for
654 matching the path portion (after the slash), and is thus more
657 <p>There is an <a href="appendix.html#REGEX">Appendix</a> with a
658 brief quick-start into regular expressions, you also might want to
659 have a look at your operating system's documentation on regular
660 expressions (try <tt class="LITERAL">man re_format</tt>).</p>
662 <p>Note that the path pattern is automatically left-anchored at the
663 <span class="QUOTE">"/"</span>, i.e. it matches as if it would start
664 with a <span class="QUOTE">"^"</span> (regular expression speak for
665 the beginning of a line).</p>
667 <p>Please also note that matching in the path is <span class=
668 "emphasis"><i class="EMPHASIS">CASE INSENSITIVE</i></span> by
669 default, but you can switch to case sensitive at any point in the
670 pattern by using the <span class="QUOTE">"(?-i)"</span> switch:
671 <tt class="LITERAL">www.example.com/(?-i)PaTtErN.*</tt> will match
672 only documents whose path starts with <tt class=
673 "LITERAL">PaTtErN</tt> in <span class="emphasis"><i class=
674 "EMPHASIS">exactly</i></span> this capitalization.</p>
676 <div class="VARIABLELIST">
678 <dt><tt class="LITERAL">.example.com/.*</tt></dt>
681 <p>Is equivalent to just <span class=
682 "QUOTE">".example.com"</span>, since any documents within that
683 domain are matched with or without the <span class=
684 "QUOTE">".*"</span> regular expression. This is redundant</p>
687 <dt><tt class="LITERAL">.example.com/.*/index.html$</tt></dt>
690 <p>Will match any page in the domain of <span class=
691 "QUOTE">"example.com"</span> that is named <span class=
692 "QUOTE">"index.html"</span>, and that is part of some path. For
693 example, it matches <span class=
694 "QUOTE">"www.example.com/testing/index.html"</span> but NOT
695 <span class="QUOTE">"www.example.com/index.html"</span> because
696 the regular expression called for at least two <span class=
697 "QUOTE">"/'s"</span>, thus the path requirement. It also would
699 "QUOTE">"www.example.com/testing/index_html"</span>, because of
700 the special meta-character <span class="QUOTE">"."</span>.</p>
703 <dt><tt class="LITERAL">.example.com/(.*/)?index\.html$</tt></dt>
706 <p>This regular expression is conditional so it will match any
707 page named <span class="QUOTE">"index.html"</span> regardless
708 of path which in this case can have one or more <span class=
709 "QUOTE">"/'s"</span>. And this one must contain exactly
710 <span class="QUOTE">".html"</span> (but does not have to end
715 "LITERAL">.example.com/(.*/)(ads|banners?|junk)</tt></dt>
718 <p>This regular expression will match any path of <span class=
719 "QUOTE">"example.com"</span> that contains any of the words
720 <span class="QUOTE">"ads"</span>, <span class=
721 "QUOTE">"banner"</span>, <span class="QUOTE">"banners"</span>
722 (because of the <span class="QUOTE">"?"</span>) or <span class=
723 "QUOTE">"junk"</span>. The path does not have to end in these
724 words, just contain them.</p>
728 "LITERAL">.example.com/(.*/)(ads|banners?|junk)/.*\.(jpe?g|gif|png)$</tt></dt>
731 <p>This is very much the same as above, except now it must end
732 in either <span class="QUOTE">".jpg"</span>, <span class=
733 "QUOTE">".jpeg"</span>, <span class="QUOTE">".gif"</span> or
734 <span class="QUOTE">".png"</span>. So this one is limited to
735 common image formats.</p>
740 <p>There are many, many good examples to be found in <tt class=
741 "FILENAME">default.action</tt>, and more tutorials below in <a href=
742 "appendix.html#REGEX">Appendix on regular expressions</a>.</p>
746 <h3 class="SECT3"><a name="TAG-PATTERN" id="TAG-PATTERN">8.4.3. The
749 <p>Tag patterns are used to change the applying actions based on the
750 request's tags. Tags can be created with either the <a href=
751 "actions-file.html#CLIENT-HEADER-TAGGER">client-header-tagger</a> or
753 "actions-file.html#SERVER-HEADER-TAGGER">server-header-tagger</a>
756 <p>Tag patterns have to start with <span class="QUOTE">"TAG:"</span>,
757 so <span class="APPLICATION">Privoxy</span> can tell them apart from
758 URL patterns. Everything after the colon including white space, is
759 interpreted as a regular expression with path pattern syntax, except
760 that tag patterns aren't left-anchored automatically (<span class=
761 "APPLICATION">Privoxy</span> doesn't silently add a <span class=
762 "QUOTE">"^"</span>, you have to do it yourself if you need it).</p>
764 <p>To match all requests that are tagged with <span class=
765 "QUOTE">"foo"</span> your pattern line should be <span class=
766 "QUOTE">"TAG:^foo$"</span>, <span class="QUOTE">"TAG:foo"</span>
767 would work as well, but it would also match requests whose tags
768 contain <span class="QUOTE">"foo"</span> somewhere. <span class=
769 "QUOTE">"TAG: foo"</span> wouldn't work as it requires white
772 <p>Sections can contain URL and tag patterns at the same time, but
773 tag patterns are checked after the URL patterns and thus always
774 overrule them, even if they are located before the URL patterns.</p>
776 <p>Once a new tag is added, Privoxy checks right away if it's matched
777 by one of the tag patterns and updates the action settings
778 accordingly. As a result tags can be used to activate other tagger
779 actions, as long as these other taggers look for headers that haven't
780 already be parsed.</p>
782 <p>For example you could tag client requests which use the <tt class=
783 "LITERAL">POST</tt> method, then use this tag to activate another
784 tagger that adds a tag if cookies are sent, and then use a block
785 action based on the cookie tag. This allows the outcome of one
786 action, to be input into a subsequent action. However if you'd
787 reverse the position of the described taggers, and activated the
788 method tagger based on the cookie tagger, no method tags would be
789 created. The method tagger would look for the request line, but at
790 the time the cookie tag is created, the request line has already been
793 <p>While this is a limitation you should be aware of, this kind of
794 indirection is seldom needed anyway and even the example doesn't make
799 <h3 class="SECT3"><a name="NEGATIVE-TAG-PATTERNS" id=
800 "NEGATIVE-TAG-PATTERNS">8.4.4. The Negative Tag Patterns</a></h3>
802 <p>To match requests that do not have a certain tag, specify a
803 negative tag pattern by prefixing the tag pattern line with either
804 <span class="QUOTE">"NO-REQUEST-TAG:"</span> or <span class=
805 "QUOTE">"NO-RESPONSE-TAG:"</span> instead of <span class=
806 "QUOTE">"TAG:"</span>.</p>
808 <p>Negative tag patterns created with <span class=
809 "QUOTE">"NO-REQUEST-TAG:"</span> are checked after all client headers
810 are scanned, the ones created with <span class=
811 "QUOTE">"NO-RESPONSE-TAG:"</span> are checked after all server
812 headers are scanned. In both cases all the created tags are
818 <h2 class="SECT2"><a name="ACTIONS" id="ACTIONS">8.5. Actions</a></h2>
820 <p>All actions are disabled by default, until they are explicitly
821 enabled somewhere in an actions file. Actions are turned on if preceded
822 with a <span class="QUOTE">"+"</span>, and turned off if preceded with
823 a <span class="QUOTE">"-"</span>. So a <tt class="LITERAL">+action</tt>
824 means <span class="QUOTE">"do that action"</span>, e.g. <tt class=
825 "LITERAL">+block</tt> means <span class="QUOTE">"please block URLs that
826 match the following patterns"</span>, and <tt class=
827 "LITERAL">-block</tt> means <span class="QUOTE">"don't block URLs that
828 match the following patterns, even if <tt class="LITERAL">+block</tt>
829 previously applied."</span></p>
831 <p>Again, actions are invoked by placing them on a line, enclosed in
832 curly braces and separated by whitespace, like in <tt class=
833 "LITERAL">{+some-action -some-other-action{some-parameter}}</tt>,
834 followed by a list of URL patterns, one per line, to which they apply.
835 Together, the actions line and the following pattern lines make up a
836 section of the actions file.</p>
838 <p>Actions fall into three categories:</p>
842 <p>Boolean, i.e the action can only be <span class=
843 "QUOTE">"enabled"</span> or <span class="QUOTE">"disabled"</span>.
846 <table border="0" bgcolor="#E0E0E0" width="90%">
850 +<tt class="REPLACEABLE"><i>name</i></tt> # enable action <tt class=
851 "REPLACEABLE"><i>name</i></tt>
853 "REPLACEABLE"><i>name</i></tt> # disable action <tt class="REPLACEABLE"><i>name</i></tt>
859 <p>Example: <tt class="LITERAL">+handle-as-image</tt></p>
863 <p>Parameterized, where some value is required in order to enable
864 this type of action. Syntax:</p>
866 <table border="0" bgcolor="#E0E0E0" width="90%">
870 +<tt class="REPLACEABLE"><i>name</i></tt>{<tt class=
871 "REPLACEABLE"><i>param</i></tt>} # enable action and set parameter to <tt class="REPLACEABLE"><i>param</i></tt>,
872 # overwriting parameter from previous match if necessary
874 "REPLACEABLE"><i>name</i></tt> # disable action. The parameter can be omitted
880 <p>Note that if the URL matches multiple positive forms of a
881 parameterized action, the last match wins, i.e. the params from
882 earlier matches are simply ignored.</p>
884 <p>Example: <tt class="LITERAL">+hide-user-agent{Mozilla/5.0 (X11;
885 U; FreeBSD i386; en-US; rv:1.8.1.4) Gecko/20070602
886 Firefox/2.0.0.4}</tt></p>
890 <p>Multi-value. These look exactly like parameterized actions, but
891 they behave differently: If the action applies multiple times to
892 the same URL, but with different parameters, <span class=
893 "emphasis"><i class="EMPHASIS">all</i></span> the parameters from
894 <span class="emphasis"><i class="EMPHASIS">all</i></span> matches
895 are remembered. This is used for actions that can be executed for
896 the same request repeatedly, like adding multiple headers, or
897 filtering through multiple filters. Syntax:</p>
899 <table border="0" bgcolor="#E0E0E0" width="90%">
903 +<tt class="REPLACEABLE"><i>name</i></tt>{<tt class=
904 "REPLACEABLE"><i>param</i></tt>} # enable action and add <tt class=
905 "REPLACEABLE"><i>param</i></tt> to the list of parameters
906 -<tt class="REPLACEABLE"><i>name</i></tt>{<tt class=
907 "REPLACEABLE"><i>param</i></tt>} # remove the parameter <tt class=
908 "REPLACEABLE"><i>param</i></tt> from the list of parameters
909 # If it was the last one left, disable the action.
911 "REPLACEABLE"><i>-name</i></tt> # disable this action completely and remove all parameters from the list
917 <p>Examples: <tt class="LITERAL">+add-header{X-Fun-Header: Some
918 text}</tt> and <tt class=
919 "LITERAL">+filter{html-annoyances}</tt></p>
923 <p>If nothing is specified in any actions file, no <span class=
924 "QUOTE">"actions"</span> are taken. So in this case <span class=
925 "APPLICATION">Privoxy</span> would just be a normal, non-blocking,
926 non-filtering proxy. You must specifically enable the privacy and
927 blocking features you need (although the provided default actions files
928 will give a good starting point).</p>
930 <p>Later defined action sections always over-ride earlier ones of the
931 same type. So exceptions to any rules you make, should come in the
932 latter part of the file (or in a file that is processed later when
933 using multiple actions files such as <tt class=
934 "FILENAME">user.action</tt>). For multi-valued actions, the actions are
935 applied in the order they are specified. Actions files are processed in
936 the order they are defined in <tt class="FILENAME">config</tt> (the
937 default installation has three actions files). It also quite possible
938 for any given URL to match more than one <span class=
939 "QUOTE">"pattern"</span> (because of wildcards and regular
940 expressions), and thus to trigger more than one set of actions! Last
943 <p>The list of valid <span class="APPLICATION">Privoxy</span> actions
947 <h4 class="SECT3"><a name="ADD-HEADER" id="ADD-HEADER">8.5.1.
950 <div class="VARIABLELIST">
952 <dt>Typical use:</dt>
955 <p>Confuse log analysis, custom applications</p>
961 <p>Sends a user defined HTTP header to the web server.</p>
973 <p>Any string value is possible. Validity of the defined HTTP
974 headers is not checked. It is recommended that you use the
975 <span class="QUOTE">"<tt class="LITERAL">X-</tt>"</span> prefix
976 for custom headers.</p>
982 <p>This action may be specified multiple times, in order to
983 define multiple headers. This is rarely needed for the typical
984 user. If you don't know what <span class="QUOTE">"HTTP
985 headers"</span> are, you definitely don't need to worry about
988 <p>Headers added by this action are not modified by other
992 <dt>Example usage:</dt>
995 <table border="0" bgcolor="#E0E0E0" width="90%">
999 +add-header{X-User-Tracking: sucks}
1010 <h4 class="SECT3"><a name="BLOCK" id="BLOCK">8.5.2. block</a></h4>
1012 <div class="VARIABLELIST">
1014 <dt>Typical use:</dt>
1017 <p>Block ads or other unwanted content</p>
1023 <p>Requests for URLs to which this action applies are blocked,
1024 i.e. the requests are trapped by <span class=
1025 "APPLICATION">Privoxy</span> and the requested URL is never
1026 retrieved, but is answered locally with a substitute page or
1027 image, as determined by the <tt class="LITERAL"><a href=
1028 "actions-file.html#HANDLE-AS-IMAGE">handle-as-image</a></tt>,
1029 <tt class="LITERAL"><a href=
1030 "actions-file.html#SET-IMAGE-BLOCKER">set-image-blocker</a></tt>,
1031 and <tt class="LITERAL"><a href=
1032 "actions-file.html#HANDLE-AS-EMPTY-DOCUMENT">handle-as-empty-document</a></tt>
1039 <p>Parameterized.</p>
1045 <p>A block reason that should be given to the user.</p>
1051 <p><span class="APPLICATION">Privoxy</span> sends a special
1052 <span class="QUOTE">"BLOCKED"</span> page for requests to
1053 blocked pages. This page contains the block reason given as
1054 parameter, a link to find out why the block action applies, and
1055 a click-through to the blocked content (the latter only if the
1056 force feature is available and enabled).</p>
1058 <p>A very important exception occurs if <span class=
1059 "emphasis"><i class="EMPHASIS">both</i></span> <tt class=
1060 "LITERAL">block</tt> and <tt class="LITERAL"><a href=
1061 "actions-file.html#HANDLE-AS-IMAGE">handle-as-image</a></tt>,
1062 apply to the same request: it will then be replaced by an
1063 image. If <tt class="LITERAL"><a href=
1064 "actions-file.html#SET-IMAGE-BLOCKER">set-image-blocker</a></tt>
1065 (see below) also applies, the type of image will be determined
1066 by its parameter, if not, the standard checkerboard pattern is
1069 <p>It is important to understand this process, in order to
1070 understand how <span class="APPLICATION">Privoxy</span> deals
1071 with ads and other unwanted content. Blocking is a core
1072 feature, and one upon which various other features depend.</p>
1074 <p>The <tt class="LITERAL"><a href=
1075 "actions-file.html#FILTER">filter</a></tt> action can perform a
1076 very similar task, by <span class="QUOTE">"blocking"</span>
1077 banner images and other content through rewriting the relevant
1078 URLs in the document's HTML source, so they don't get requested
1079 in the first place. Note that this is a totally different
1080 technique, and it's easy to confuse the two.</p>
1083 <dt>Example usage (section):</dt>
1086 <table border="0" bgcolor="#E0E0E0" width="90%">
1089 <pre class="SCREEN">
1090 {+block{No nasty stuff for you.}}
1091 # Block and replace with "blocked" page
1092 .nasty-stuff.example.com
1094 {+block{Doubleclick banners.} +handle-as-image}
1095 # Block and replace with image
1099 {+block{Layered ads.} +handle-as-empty-document}
1100 # Block and then ignore
1101 adserver.example.net/.*\.js$
1112 <h4 class="SECT3"><a name="CHANGE-X-FORWARDED-FOR" id=
1113 "CHANGE-X-FORWARDED-FOR">8.5.3. change-x-forwarded-for</a></h4>
1115 <div class="VARIABLELIST">
1117 <dt>Typical use:</dt>
1120 <p>Improve privacy by not forwarding the source of the request
1121 in the HTTP headers.</p>
1127 <p>Deletes the <span class="QUOTE">"X-Forwarded-For:"</span>
1128 HTTP header from the client request, or adds a new one.</p>
1134 <p>Parameterized.</p>
1142 <p><span class="QUOTE">"block"</span> to delete the
1147 <p><span class="QUOTE">"add"</span> to create the header
1148 (or append the client's IP address to an already existing
1157 <p>It is safe and recommended to use <tt class=
1158 "LITERAL">block</tt>.</p>
1160 <p>Forwarding the source address of the request may make sense
1161 in some multi-user setups but is also a privacy risk.</p>
1164 <dt>Example usage:</dt>
1167 <table border="0" bgcolor="#E0E0E0" width="90%">
1170 <pre class="SCREEN">
1171 +change-x-forwarded-for{block}
1182 <h4 class="SECT3"><a name="CLIENT-HEADER-FILTER" id=
1183 "CLIENT-HEADER-FILTER">8.5.4. client-header-filter</a></h4>
1185 <div class="VARIABLELIST">
1187 <dt>Typical use:</dt>
1190 <p>Rewrite or remove single client headers.</p>
1196 <p>All client headers to which this action applies are filtered
1197 on-the-fly through the specified regular expression based
1210 <p>The name of a client-header filter, as defined in one of the
1211 <a href="filter-file.html">filter files</a>.</p>
1217 <p>Client-header filters are applied to each header on its own,
1218 not to all at once. This makes it easier to diagnose problems,
1219 but on the downside you can't write filters that only change
1220 header x if header y's value is z. You can do that by using
1223 <p>Client-header filters are executed after the other header
1224 actions have finished and use their output as input.</p>
1226 <p>If the request URI gets changed, <span class=
1227 "APPLICATION">Privoxy</span> will detect that and use the new
1228 one. This can be used to rewrite the request destination behind
1229 the client's back, for example to specify a Tor exit relay for
1230 certain requests.</p>
1232 <p>Please refer to the <a href="filter-file.html">filter file
1233 chapter</a> to learn which client-header filters are available
1234 by default, and how to create your own.</p>
1237 <dt>Example usage (section):</dt>
1240 <table border="0" bgcolor="#E0E0E0" width="90%">
1243 <pre class="SCREEN">
1244 # Hide Tor exit notation in Host and Referer Headers
1245 {+client-header-filter{hide-tor-exit-notation}}
1258 <h4 class="SECT3"><a name="CLIENT-HEADER-TAGGER" id=
1259 "CLIENT-HEADER-TAGGER">8.5.5. client-header-tagger</a></h4>
1261 <div class="VARIABLELIST">
1263 <dt>Typical use:</dt>
1266 <p>Block requests based on their headers.</p>
1272 <p>Client headers to which this action applies are filtered
1273 on-the-fly through the specified regular expression based
1274 substitutions, the result is used as tag.</p>
1286 <p>The name of a client-header tagger, as defined in one of the
1287 <a href="filter-file.html">filter files</a>.</p>
1293 <p>Client-header taggers are applied to each header on its own,
1294 and as the header isn't modified, each tagger <span class=
1295 "QUOTE">"sees"</span> the original.</p>
1297 <p>Client-header taggers are the first actions that are
1298 executed and their tags can be used to control every other
1302 <dt>Example usage (section):</dt>
1305 <table border="0" bgcolor="#E0E0E0" width="90%">
1308 <pre class="SCREEN">
1309 # Tag every request with the User-Agent header
1310 {+client-header-tagger{user-agent}}
1313 # Tagging itself doesn't change the action
1314 # settings, sections with TAG patterns do:
1316 # If it's a download agent, use a different forwarding proxy,
1317 # show the real User-Agent and make sure resume works.
1318 {+forward-override{forward-socks5 10.0.0.2:2222 .} \
1319 -hide-if-modified-since \
1320 -overwrite-last-modified \
1325 TAG:^User-Agent: NetBSD-ftp/
1326 TAG:^User-Agent: Novell ZYPP Installer
1327 TAG:^User-Agent: RPM APT-HTTP/
1328 TAG:^User-Agent: fetch libfetch/
1329 TAG:^User-Agent: Ubuntu APT-HTTP/
1330 TAG:^User-Agent: MPlayer/
1337 <table border="0" bgcolor="#E0E0E0" width="90%">
1340 <pre class="SCREEN">
1341 # Tag all requests with the Range header set
1342 {+client-header-tagger{range-requests}}
1345 # Disable filtering for the tagged requests.
1347 # With filtering enabled Privoxy would remove the Range headers
1348 # to be able to filter the whole response. The downside is that
1349 # it prevents clients from resuming downloads or skipping over
1350 # parts of multimedia files.
1351 {-filter -deanimate-gifs}
1364 <h4 class="SECT3"><a name="CONTENT-TYPE-OVERWRITE" id=
1365 "CONTENT-TYPE-OVERWRITE">8.5.6. content-type-overwrite</a></h4>
1367 <div class="VARIABLELIST">
1369 <dt>Typical use:</dt>
1372 <p>Stop useless download menus from popping up, or change the
1373 browser's rendering mode</p>
1379 <p>Replaces the <span class="QUOTE">"Content-Type:"</span> HTTP
1386 <p>Parameterized.</p>
1398 <p>The <span class="QUOTE">"Content-Type:"</span> HTTP server
1399 header is used by the browser to decide what to do with the
1400 document. The value of this header can cause the browser to
1401 open a download menu instead of displaying the document by
1402 itself, even if the document's format is supported by the
1405 <p>The declared content type can also affect which rendering
1406 mode the browser chooses. If XHTML is delivered as <span class=
1407 "QUOTE">"text/html"</span>, many browsers treat it as yet
1408 another broken HTML document. If it is send as <span class=
1409 "QUOTE">"application/xml"</span>, browsers with XHTML support
1410 will only display it, if the syntax is correct.</p>
1412 <p>If you see a web site that proudly uses XHTML buttons, but
1413 sets <span class="QUOTE">"Content-Type: text/html"</span>, you
1414 can use <span class="APPLICATION">Privoxy</span> to overwrite
1415 it with <span class="QUOTE">"application/xml"</span> and
1416 validate the web master's claim inside your XHTML-supporting
1417 browser. If the syntax is incorrect, the browser will complain
1420 <p>You can also go the opposite direction: if your browser
1421 prints error messages instead of rendering a document falsely
1422 declared as XHTML, you can overwrite the content type with
1423 <span class="QUOTE">"text/html"</span> and have it rendered as
1424 broken HTML document.</p>
1426 <p>By default <tt class="LITERAL">content-type-overwrite</tt>
1427 only replaces <span class="QUOTE">"Content-Type:"</span>
1428 headers that look like some kind of text. If you want to
1429 overwrite it unconditionally, you have to combine it with
1430 <tt class="LITERAL"><a href=
1431 "actions-file.html#FORCE-TEXT-MODE">force-text-mode</a></tt>.
1432 This limitation exists for a reason, think twice before
1433 circumventing it.</p>
1435 <p>Most of the time it's easier to replace this action with a
1436 custom <tt class="LITERAL"><a href=
1437 "actions-file.html#SERVER-HEADER-FILTER">server-header
1438 filter</a></tt>. It allows you to activate it for every
1439 document of a certain site and it will still only replace the
1440 content types you aimed at.</p>
1442 <p>Of course you can apply <tt class=
1443 "LITERAL">content-type-overwrite</tt> to a whole site and then
1444 make URL based exceptions, but it's a lot more work to get the
1448 <dt>Example usage (sections):</dt>
1451 <table border="0" bgcolor="#E0E0E0" width="90%">
1454 <pre class="SCREEN">
1455 # Check if www.example.net/ really uses valid XHTML
1456 { +content-type-overwrite{application/xml} }
1459 # but leave the content type unmodified if the URL looks like a style sheet
1460 {-content-type-overwrite}
1461 www.example.net/.*\.css$
1462 www.example.net/.*style
1473 <h4 class="SECT3"><a name="CRUNCH-CLIENT-HEADER" id=
1474 "CRUNCH-CLIENT-HEADER">8.5.7. crunch-client-header</a></h4>
1476 <div class="VARIABLELIST">
1478 <dt>Typical use:</dt>
1481 <p>Remove a client header <span class=
1482 "APPLICATION">Privoxy</span> has no dedicated action for.</p>
1488 <p>Deletes every header sent by the client that contains the
1489 string the user supplied as parameter.</p>
1495 <p>Parameterized.</p>
1507 <p>This action allows you to block client headers for which no
1508 dedicated <span class="APPLICATION">Privoxy</span> action
1509 exists. <span class="APPLICATION">Privoxy</span> will remove
1510 every client header that contains the string you supplied as
1513 <p>Regular expressions are <span class="emphasis"><i class=
1514 "EMPHASIS">not supported</i></span> and you can't use this
1515 action to block different headers in the same request, unless
1516 they contain the same string.</p>
1518 <p><tt class="LITERAL">crunch-client-header</tt> is only meant
1519 for quick tests. If you have to block several different
1520 headers, or only want to modify parts of them, you should use a
1521 <tt class="LITERAL"><a href=
1522 "actions-file.html#CLIENT-HEADER-FILTER">client-header
1523 filter</a></tt>.</p>
1525 <div class="WARNING">
1526 <table class="WARNING" border="1" width="90%">
1528 <td align="center"><b>Warning</b></td>
1533 <p>Don't block any header without understanding the
1541 <dt>Example usage (section):</dt>
1544 <table border="0" bgcolor="#E0E0E0" width="90%">
1547 <pre class="SCREEN">
1548 # Block the non-existent "Privacy-Violation:" client header
1549 { +crunch-client-header{Privacy-Violation:} }
1562 <h4 class="SECT3"><a name="CRUNCH-IF-NONE-MATCH" id=
1563 "CRUNCH-IF-NONE-MATCH">8.5.8. crunch-if-none-match</a></h4>
1565 <div class="VARIABLELIST">
1567 <dt>Typical use:</dt>
1570 <p>Prevent yet another way to track the user's steps between
1577 <p>Deletes the <span class="QUOTE">"If-None-Match:"</span> HTTP
1596 <p>Removing the <span class="QUOTE">"If-None-Match:"</span>
1597 HTTP client header is useful for filter testing, where you want
1598 to force a real reload instead of getting status code
1599 <span class="QUOTE">"304"</span> which would cause the browser
1600 to use a cached copy of the page.</p>
1602 <p>It is also useful to make sure the header isn't used as a
1603 cookie replacement (unlikely but possible).</p>
1605 <p>Blocking the <span class="QUOTE">"If-None-Match:"</span>
1606 header shouldn't cause any caching problems, as long as the
1607 <span class="QUOTE">"If-Modified-Since:"</span> header isn't
1608 blocked or missing as well.</p>
1610 <p>It is recommended to use this action together with
1611 <tt class="LITERAL"><a href=
1612 "actions-file.html#HIDE-IF-MODIFIED-SINCE">hide-if-modified-since</a></tt>
1613 and <tt class="LITERAL"><a href=
1614 "actions-file.html#OVERWRITE-LAST-MODIFIED">overwrite-last-modified</a></tt>.</p>
1617 <dt>Example usage (section):</dt>
1620 <table border="0" bgcolor="#E0E0E0" width="90%">
1623 <pre class="SCREEN">
1624 # Let the browser revalidate cached documents but don't
1625 # allow the server to use the revalidation headers for user tracking.
1626 {+hide-if-modified-since{-60} \
1627 +overwrite-last-modified{randomize} \
1628 +crunch-if-none-match}
1640 <h4 class="SECT3"><a name="CRUNCH-INCOMING-COOKIES" id=
1641 "CRUNCH-INCOMING-COOKIES">8.5.9. crunch-incoming-cookies</a></h4>
1643 <div class="VARIABLELIST">
1645 <dt>Typical use:</dt>
1648 <p>Prevent the web server from setting HTTP cookies on your
1655 <p>Deletes any <span class="QUOTE">"Set-Cookie:"</span> HTTP
1656 headers from server replies.</p>
1674 <p>This action is only concerned with <span class=
1675 "emphasis"><i class="EMPHASIS">incoming</i></span> HTTP
1676 cookies. For <span class="emphasis"><i class=
1677 "EMPHASIS">outgoing</i></span> HTTP cookies, use <tt class=
1679 "actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</a></tt>.
1680 Use <span class="emphasis"><i class="EMPHASIS">both</i></span>
1681 to disable HTTP cookies completely.</p>
1683 <p>It makes <span class="emphasis"><i class="EMPHASIS">no sense
1684 at all</i></span> to use this action in conjunction with the
1685 <tt class="LITERAL"><a href=
1686 "actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</a></tt>
1687 action, since it would prevent the session cookies from being
1688 set. See also <tt class="LITERAL"><a href=
1689 "actions-file.html#FILTER-CONTENT-COOKIES">filter-content-cookies</a></tt>.</p>
1692 <dt>Example usage:</dt>
1695 <table border="0" bgcolor="#E0E0E0" width="90%">
1698 <pre class="SCREEN">
1699 +crunch-incoming-cookies
1710 <h4 class="SECT3"><a name="CRUNCH-SERVER-HEADER" id=
1711 "CRUNCH-SERVER-HEADER">8.5.10. crunch-server-header</a></h4>
1713 <div class="VARIABLELIST">
1715 <dt>Typical use:</dt>
1718 <p>Remove a server header <span class=
1719 "APPLICATION">Privoxy</span> has no dedicated action for.</p>
1725 <p>Deletes every header sent by the server that contains the
1726 string the user supplied as parameter.</p>
1732 <p>Parameterized.</p>
1744 <p>This action allows you to block server headers for which no
1745 dedicated <span class="APPLICATION">Privoxy</span> action
1746 exists. <span class="APPLICATION">Privoxy</span> will remove
1747 every server header that contains the string you supplied as
1750 <p>Regular expressions are <span class="emphasis"><i class=
1751 "EMPHASIS">not supported</i></span> and you can't use this
1752 action to block different headers in the same request, unless
1753 they contain the same string.</p>
1755 <p><tt class="LITERAL">crunch-server-header</tt> is only meant
1756 for quick tests. If you have to block several different
1757 headers, or only want to modify parts of them, you should use a
1758 custom <tt class="LITERAL"><a href=
1759 "actions-file.html#SERVER-HEADER-FILTER">server-header
1760 filter</a></tt>.</p>
1762 <div class="WARNING">
1763 <table class="WARNING" border="1" width="90%">
1765 <td align="center"><b>Warning</b></td>
1770 <p>Don't block any header without understanding the
1778 <dt>Example usage (section):</dt>
1781 <table border="0" bgcolor="#E0E0E0" width="90%">
1784 <pre class="SCREEN">
1785 # Crunch server headers that try to prevent caching
1786 { +crunch-server-header{no-cache} }
1798 <h4 class="SECT3"><a name="CRUNCH-OUTGOING-COOKIES" id=
1799 "CRUNCH-OUTGOING-COOKIES">8.5.11. crunch-outgoing-cookies</a></h4>
1801 <div class="VARIABLELIST">
1803 <dt>Typical use:</dt>
1806 <p>Prevent the web server from reading any HTTP cookies from
1813 <p>Deletes any <span class="QUOTE">"Cookie:"</span> HTTP
1814 headers from client requests.</p>
1832 <p>This action is only concerned with <span class=
1833 "emphasis"><i class="EMPHASIS">outgoing</i></span> HTTP
1834 cookies. For <span class="emphasis"><i class=
1835 "EMPHASIS">incoming</i></span> HTTP cookies, use <tt class=
1837 "actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</a></tt>.
1838 Use <span class="emphasis"><i class="EMPHASIS">both</i></span>
1839 to disable HTTP cookies completely.</p>
1841 <p>It makes <span class="emphasis"><i class="EMPHASIS">no sense
1842 at all</i></span> to use this action in conjunction with the
1843 <tt class="LITERAL"><a href=
1844 "actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</a></tt>
1845 action, since it would prevent the session cookies from being
1849 <dt>Example usage:</dt>
1852 <table border="0" bgcolor="#E0E0E0" width="90%">
1855 <pre class="SCREEN">
1856 +crunch-outgoing-cookies
1867 <h4 class="SECT3"><a name="DEANIMATE-GIFS" id=
1868 "DEANIMATE-GIFS">8.5.12. deanimate-gifs</a></h4>
1870 <div class="VARIABLELIST">
1872 <dt>Typical use:</dt>
1875 <p>Stop those annoying, distracting animated GIF images.</p>
1881 <p>De-animate GIF animations, i.e. reduce them to their first
1888 <p>Parameterized.</p>
1894 <p><span class="QUOTE">"last"</span> or <span class=
1895 "QUOTE">"first"</span></p>
1901 <p>This will also shrink the images considerably (in bytes, not
1902 pixels!). If the option <span class="QUOTE">"first"</span> is
1903 given, the first frame of the animation is used as the
1904 replacement. If <span class="QUOTE">"last"</span> is given, the
1905 last frame of the animation is used instead, which probably
1906 makes more sense for most banner animations, but also has the
1907 risk of not showing the entire last frame (if it is only a
1908 delta to an earlier frame).</p>
1910 <p>You can safely use this action with patterns that will also
1911 match non-GIF objects, because no attempt will be made at
1912 anything that doesn't look like a GIF.</p>
1915 <dt>Example usage:</dt>
1918 <table border="0" bgcolor="#E0E0E0" width="90%">
1921 <pre class="SCREEN">
1922 +deanimate-gifs{last}
1933 <h4 class="SECT3"><a name="DOWNGRADE-HTTP-VERSION" id=
1934 "DOWNGRADE-HTTP-VERSION">8.5.13. downgrade-http-version</a></h4>
1936 <div class="VARIABLELIST">
1938 <dt>Typical use:</dt>
1941 <p>Work around (very rare) problems with HTTP/1.1</p>
1947 <p>Downgrades HTTP/1.1 client requests and server replies to
1966 <p>This is a left-over from the time when <span class=
1967 "APPLICATION">Privoxy</span> didn't support important HTTP/1.1
1968 features well. It is left here for the unlikely case that you
1969 experience HTTP/1.1-related problems with some server out
1972 <p>Note that enabling this action is only a workaround. It
1973 should not be enabled for sites that work without it. While it
1974 shouldn't break any pages, it has an (usually negative)
1975 performance impact.</p>
1977 <p>If you come across a site where enabling this action helps,
1978 please report it, so the cause of the problem can be analyzed.
1979 If the problem turns out to be caused by a bug in <span class=
1980 "APPLICATION">Privoxy</span> it should be fixed so the
1981 following release works without the work around.</p>
1984 <dt>Example usage (section):</dt>
1987 <table border="0" bgcolor="#E0E0E0" width="90%">
1990 <pre class="SCREEN">
1991 {+downgrade-http-version}
1992 problem-host.example.com
2003 <h4 class="SECT3"><a name="EXTERNAL-FILTER" id=
2004 "EXTERNAL-FILTER">8.5.14. external-filter</a></h4>
2006 <div class="VARIABLELIST">
2008 <dt>Typical use:</dt>
2011 <p>Modify content using a programming language of your
2018 <p>All instances of text-based type, most notably HTML and
2019 JavaScript, to which this action applies, can be filtered
2020 on-the-fly through the specified external filter. By default
2021 plain text documents are exempted from filtering, because web
2022 servers often use the <tt class="LITERAL">text/plain</tt> MIME
2023 type for all files whose type they don't know.)</p>
2035 <p>The name of an external content filter, as defined in the
2036 <a href="filter-file.html">filter file</a>. External filters
2037 can be defined in one or more files as defined by the
2038 <tt class="LITERAL"><a href=
2039 "config.html#FILTERFILE">filterfile</a></tt> option in the
2040 <a href="config.html">config file</a>.</p>
2042 <p>When used in its negative form, and without parameters,
2043 <span class="emphasis"><i class="EMPHASIS">all</i></span>
2044 filtering with external filters is completely disabled.</p>
2050 <p>External filters are scripts or programs that can modify the
2051 content in case common <tt class="LITERAL"><a href=
2052 "actions-file.html#FILTER">filters</a></tt> aren't powerful
2053 enough. With the exception that this action doesn't use
2054 pcrs-based filters, the notes in the <tt class=
2055 "LITERAL"><a href="actions-file.html#FILTER">filter</a></tt>
2058 <div class="WARNING">
2059 <table class="WARNING" border="1" width="90%">
2061 <td align="center"><b>Warning</b></td>
2066 <p>Currently external filters are executed with
2067 <span class="APPLICATION">Privoxy</span>'s privileges.
2068 Only use external filters you understand and trust.</p>
2074 <p>This feature is experimental, the <tt class=
2076 "filter-file.html#EXTERNAL-FILTER-SYNTAX">syntax</a></tt> may
2077 change in the future.</p>
2080 <dt>Example usage:</dt>
2083 <table border="0" bgcolor="#E0E0E0" width="90%">
2086 <pre class="SCREEN">
2087 +external-filter{fancy-filter}
2098 <h4 class="SECT3"><a name="FAST-REDIRECTS" id=
2099 "FAST-REDIRECTS">8.5.15. fast-redirects</a></h4>
2101 <div class="VARIABLELIST">
2103 <dt>Typical use:</dt>
2106 <p>Fool some click-tracking scripts and speed up indirect
2113 <p>Detects redirection URLs and redirects the browser without
2114 contacting the redirection server first.</p>
2120 <p>Parameterized.</p>
2128 <p><span class="QUOTE">"simple-check"</span> to just search
2129 for the string <span class="QUOTE">"http://"</span> to
2130 detect redirection URLs.</p>
2134 <p><span class="QUOTE">"check-decoded-url"</span> to decode
2135 URLs (if necessary) before searching for redirection
2144 <p>Many sites, like yahoo.com, don't just link to other sites.
2145 Instead, they will link to some script on their own servers,
2146 giving the destination as a parameter, which will then redirect
2147 you to the final target. URLs resulting from this scheme
2148 typically look like: <span class=
2149 "QUOTE">"http://www.example.org/click-tracker.cgi?target=http%3a//www.example.net/"</span>.</p>
2151 <p>Sometimes, there are even multiple consecutive redirects
2152 encoded in the URL. These redirections via scripts make your
2153 web browsing more traceable, since the server from which you
2154 follow such a link can see where you go to. Apart from that,
2155 valuable bandwidth and time is wasted, while your browser asks
2156 the server for one redirect after the other. Plus, it feeds the
2159 <p>This feature is currently not very smart and is scheduled
2160 for improvement. If it is enabled by default, you will have to
2161 create some exceptions to this action. It can lead to failures
2162 in several ways:</p>
2164 <p>Not every URLs with other URLs as parameters is evil. Some
2165 sites offer a real service that requires this information to
2166 work. For example a validation service needs to know, which
2167 document to validate. <tt class="LITERAL">fast-redirects</tt>
2168 assumes that every URL parameter that looks like another URL is
2169 a redirection target, and will always redirect to the last one.
2170 Most of the time the assumption is correct, but if it isn't,
2171 the user gets redirected anyway.</p>
2173 <p>Another failure occurs if the URL contains other parameters
2174 after the URL parameter. The URL: <span class=
2175 "QUOTE">"http://www.example.org/?redirect=http%3a//www.example.net/&foo=bar"</span>.
2176 contains the redirection URL <span class=
2177 "QUOTE">"http://www.example.net/"</span>, followed by another
2178 parameter. <tt class="LITERAL">fast-redirects</tt> doesn't know
2179 that and will cause a redirect to <span class=
2180 "QUOTE">"http://www.example.net/&foo=bar"</span>. Depending
2181 on the target server configuration, the parameter will be
2182 silently ignored or lead to a <span class="QUOTE">"page not
2183 found"</span> error. You can prevent this problem by first
2184 using the <tt class="LITERAL"><a href=
2185 "actions-file.html#REDIRECT">redirect</a></tt> action to remove
2186 the last part of the URL, but it requires a little effort.</p>
2188 <p>To detect a redirection URL, <tt class=
2189 "LITERAL">fast-redirects</tt> only looks for the string
2190 <span class="QUOTE">"http://"</span>, either in plain text
2191 (invalid but often used) or encoded as <span class=
2192 "QUOTE">"http%3a//"</span>. Some sites use their own URL
2193 encoding scheme, encrypt the address of the target server or
2194 replace it with a database id. In theses cases <tt class=
2195 "LITERAL">fast-redirects</tt> is fooled and the request reaches
2196 the redirection server where it probably gets logged.</p>
2199 <dt>Example usage:</dt>
2202 <table border="0" bgcolor="#E0E0E0" width="90%">
2205 <pre class="SCREEN">
2206 { +fast-redirects{simple-check} }
2209 { +fast-redirects{check-decoded-url} }
2210 another.example.com/testing
2221 <h4 class="SECT3"><a name="FILTER" id="FILTER">8.5.16.
2224 <div class="VARIABLELIST">
2226 <dt>Typical use:</dt>
2229 <p>Get rid of HTML and JavaScript annoyances, banner
2230 advertisements (by size), do fun text replacements, add
2231 personalized effects, etc.</p>
2237 <p>All instances of text-based type, most notably HTML and
2238 JavaScript, to which this action applies, can be filtered
2239 on-the-fly through the specified regular expression based
2240 substitutions. (Note: as of version 3.0.3 plain text documents
2241 are exempted from filtering, because web servers often use the
2242 <tt class="LITERAL">text/plain</tt> MIME type for all files
2243 whose type they don't know.)</p>
2255 <p>The name of a content filter, as defined in the <a href=
2256 "filter-file.html">filter file</a>. Filters can be defined in
2257 one or more files as defined by the <tt class=
2258 "LITERAL"><a href="config.html#FILTERFILE">filterfile</a></tt>
2259 option in the <a href="config.html">config file</a>. <tt class=
2260 "FILENAME">default.filter</tt> is the collection of filters
2261 supplied by the developers. Locally defined filters should go
2262 in their own file, such as <tt class=
2263 "FILENAME">user.filter</tt>.</p>
2265 <p>When used in its negative form, and without parameters,
2266 <span class="emphasis"><i class="EMPHASIS">all</i></span>
2267 filtering is completely disabled.</p>
2273 <p>For your convenience, there are a number of pre-defined
2274 filters available in the distribution filter file that you can
2275 use. See the examples below for a list.</p>
2277 <p>Filtering requires buffering the page content, which may
2278 appear to slow down page rendering since nothing is displayed
2279 until all content has passed the filters. (The total time until
2280 the page is completely rendered doesn't change much, but it may
2281 be perceived as slower since the page is not incrementally
2282 displayed.) This effect will be more noticeable on slower
2285 <p><span class="QUOTE">"Rolling your own"</span> filters
2286 requires a knowledge of <a href=
2287 "http://en.wikipedia.org/wiki/Regular_expressions" target=
2288 "_top"><span class="QUOTE">"Regular Expressions"</span></a> and
2289 <a href="http://en.wikipedia.org/wiki/Html" target=
2290 "_top"><span class="QUOTE">"HTML"</span></a>. This is very
2291 powerful feature, and potentially very intrusive. Filters
2292 should be used with caution, and where an equivalent
2293 <span class="QUOTE">"action"</span> is not available.</p>
2295 <p>The amount of data that can be filtered is limited to the
2296 <tt class="LITERAL"><a href=
2297 "config.html#BUFFER-LIMIT">buffer-limit</a></tt> option in the
2298 main <a href="config.html">config file</a>. The default is 4096
2299 KB (4 Megs). Once this limit is exceeded, the buffered data,
2300 and all pending data, is passed through unfiltered.</p>
2302 <p>Inappropriate MIME types, such as zipped files, are not
2303 filtered at all. (Again, only text-based types except plain
2304 text). Encrypted SSL data (from HTTPS servers) cannot be
2305 filtered either, since this would violate the integrity of the
2306 secure transaction. In some situations it might be necessary to
2307 protect certain text, like source code, from filtering by
2308 defining appropriate <tt class="LITERAL">-filter</tt>
2311 <p>Compressed content can't be filtered either, but if
2312 <span class="APPLICATION">Privoxy</span> is compiled with zlib
2313 support and a supported compression algorithm is used (gzip or
2314 deflate), <span class="APPLICATION">Privoxy</span> can first
2315 decompress the content and then filter it.</p>
2317 <p>If you use a <span class="APPLICATION">Privoxy</span>
2318 version without zlib support, but want filtering to work on as
2319 much documents as possible, even those that would normally be
2320 sent compressed, you must use the <tt class="LITERAL"><a href=
2321 "actions-file.html#PREVENT-COMPRESSION">prevent-compression</a></tt>
2322 action in conjunction with <tt class="LITERAL">filter</tt>.</p>
2324 <p>Content filtering can achieve some of the same effects as
2325 the <tt class="LITERAL"><a href=
2326 "actions-file.html#BLOCK">block</a></tt> action, i.e. it can be
2327 used to block ads and banners. But the mechanism works quite
2328 differently. One effective use, is to block ad banners based on
2329 their size (see below), since many of these seem to be somewhat
2332 <p><a href="contact.html">Feedback</a> with suggestions for new
2333 or improved filters is particularly welcome!</p>
2335 <p>The below list has only the names and a one-line description
2336 of each predefined filter. There are <a href=
2337 "filter-file.html#PREDEFINED-FILTERS">more verbose
2338 explanations</a> of what these filters do in the <a href=
2339 "filter-file.html">filter file chapter</a>.</p>
2342 <dt>Example usage (with filters from the distribution <tt class=
2343 "FILENAME">default.filter</tt> file). See <a href=
2344 "filter-file.html#PREDEFINED-FILTERS">the Predefined Filters
2345 section</a> for more explanation on each:</dt>
2348 <p><a name="FILTER-JS-ANNOYANCES" id=
2349 "FILTER-JS-ANNOYANCES"></a></p>
2351 <table border="0" bgcolor="#E0E0E0" width="90%">
2354 <pre class="SCREEN">
2355 +filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse.
2361 <p><a name="FILTER-JS-EVENTS" id="FILTER-JS-EVENTS"></a></p>
2363 <table border="0" bgcolor="#E0E0E0" width="90%">
2366 <pre class="SCREEN">
2367 +filter{js-events} # Kill JavaScript event bindings and timers (Radically destructive! Only for extra nasty sites).
2373 <p><a name="FILTER-HTML-ANNOYANCES" id=
2374 "FILTER-HTML-ANNOYANCES"></a></p>
2376 <table border="0" bgcolor="#E0E0E0" width="90%">
2379 <pre class="SCREEN">
2380 +filter{html-annoyances} # Get rid of particularly annoying HTML abuse.
2386 <p><a name="FILTER-CONTENT-COOKIES" id=
2387 "FILTER-CONTENT-COOKIES"></a></p>
2389 <table border="0" bgcolor="#E0E0E0" width="90%">
2392 <pre class="SCREEN">
2393 +filter{content-cookies} # Kill cookies that come in the HTML or JS content.
2399 <p><a name="FILTER-REFRESH-TAGS" id=
2400 "FILTER-REFRESH-TAGS"></a></p>
2402 <table border="0" bgcolor="#E0E0E0" width="90%">
2405 <pre class="SCREEN">
2406 +filter{refresh-tags} # Kill automatic refresh tags if refresh time is larger than 9 seconds.
2412 <p><a name="FILTER-UNSOLICITED-POPUPS" id=
2413 "FILTER-UNSOLICITED-POPUPS"></a></p>
2415 <table border="0" bgcolor="#E0E0E0" width="90%">
2418 <pre class="SCREEN">
2419 +filter{unsolicited-popups} # Disable only unsolicited pop-up windows.
2425 <p><a name="FILTER-ALL-POPUPS" id="FILTER-ALL-POPUPS"></a></p>
2427 <table border="0" bgcolor="#E0E0E0" width="90%">
2430 <pre class="SCREEN">
2431 +filter{all-popups} # Kill all popups in JavaScript and HTML.
2437 <p><a name="FILTER-IMG-REORDER" id=
2438 "FILTER-IMG-REORDER"></a></p>
2440 <table border="0" bgcolor="#E0E0E0" width="90%">
2443 <pre class="SCREEN">
2444 +filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective.
2450 <p><a name="FILTER-BANNERS-BY-SIZE" id=
2451 "FILTER-BANNERS-BY-SIZE"></a></p>
2453 <table border="0" bgcolor="#E0E0E0" width="90%">
2456 <pre class="SCREEN">
2457 +filter{banners-by-size} # Kill banners by size.
2463 <p><a name="FILTER-BANNERS-BY-LINK" id=
2464 "FILTER-BANNERS-BY-LINK"></a></p>
2466 <table border="0" bgcolor="#E0E0E0" width="90%">
2469 <pre class="SCREEN">
2470 +filter{banners-by-link} # Kill banners by their links to known clicktrackers.
2476 <p><a name="FILTER-WEBBUGS" id="FILTER-WEBBUGS"></a></p>
2478 <table border="0" bgcolor="#E0E0E0" width="90%">
2481 <pre class="SCREEN">
2482 +filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking).
2488 <p><a name="FILTER-TINY-TEXTFORMS" id=
2489 "FILTER-TINY-TEXTFORMS"></a></p>
2491 <table border="0" bgcolor="#E0E0E0" width="90%">
2494 <pre class="SCREEN">
2495 +filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap.
2501 <p><a name="FILTER-JUMPING-WINDOWS" id=
2502 "FILTER-JUMPING-WINDOWS"></a></p>
2504 <table border="0" bgcolor="#E0E0E0" width="90%">
2507 <pre class="SCREEN">
2508 +filter{jumping-windows} # Prevent windows from resizing and moving themselves.
2514 <p><a name="FILTER-FRAMESET-BORDERS" id=
2515 "FILTER-FRAMESET-BORDERS"></a></p>
2517 <table border="0" bgcolor="#E0E0E0" width="90%">
2520 <pre class="SCREEN">
2521 +filter{frameset-borders} # Give frames a border and make them resizable.
2527 <p><a name="FILTER-IFRAMES" id="FILTER-IFRAMES"></a></p>
2529 <table border="0" bgcolor="#E0E0E0" width="90%">
2532 <pre class="SCREEN">
2533 +filter{iframes} # Removes all detected iframes. Should only be enabled for individual sites.
2539 <p><a name="FILTER-DEMORONIZER" id=
2540 "FILTER-DEMORONIZER"></a></p>
2542 <table border="0" bgcolor="#E0E0E0" width="90%">
2545 <pre class="SCREEN">
2546 +filter{demoronizer} # Fix MS's non-standard use of standard charsets.
2552 <p><a name="FILTER-SHOCKWAVE-FLASH" id=
2553 "FILTER-SHOCKWAVE-FLASH"></a></p>
2555 <table border="0" bgcolor="#E0E0E0" width="90%">
2558 <pre class="SCREEN">
2559 +filter{shockwave-flash} # Kill embedded Shockwave Flash objects.
2565 <p><a name="FILTER-QUICKTIME-KIOSKMODE" id=
2566 "FILTER-QUICKTIME-KIOSKMODE"></a></p>
2568 <table border="0" bgcolor="#E0E0E0" width="90%">
2571 <pre class="SCREEN">
2572 +filter{quicktime-kioskmode} # Make Quicktime movies saveable.
2578 <p><a name="FILTER-FUN" id="FILTER-FUN"></a></p>
2580 <table border="0" bgcolor="#E0E0E0" width="90%">
2583 <pre class="SCREEN">
2584 +filter{fun} # Text replacements for subversive browsing fun!
2590 <p><a name="FILTER-CRUDE-PARENTAL" id=
2591 "FILTER-CRUDE-PARENTAL"></a></p>
2593 <table border="0" bgcolor="#E0E0E0" width="90%">
2596 <pre class="SCREEN">
2597 +filter{crude-parental} # Crude parental filtering. Note that this filter doesn't work reliably.
2603 <p><a name="FILTER-IE-EXPLOITS" id=
2604 "FILTER-IE-EXPLOITS"></a></p>
2606 <table border="0" bgcolor="#E0E0E0" width="90%">
2609 <pre class="SCREEN">
2610 +filter{ie-exploits} # Disable some known Internet Explorer bug exploits.
2616 <p><a name="FILTER-SITE-SPECIFICS" id=
2617 "FILTER-SITE-SPECIFICS"></a></p>
2619 <table border="0" bgcolor="#E0E0E0" width="90%">
2622 <pre class="SCREEN">
2623 +filter{site-specifics} # Cure for site-specific problems. Don't apply generally!
2629 <p><a name="FILTER-NO-PING" id="FILTER-NO-PING"></a></p>
2631 <table border="0" bgcolor="#E0E0E0" width="90%">
2634 <pre class="SCREEN">
2635 +filter{no-ping} # Removes non-standard ping attributes in <a> and <area> tags.
2641 <p><a name="FILTER-GOOGLE" id="FILTER-GOOGLE"></a></p>
2643 <table border="0" bgcolor="#E0E0E0" width="90%">
2646 <pre class="SCREEN">
2647 +filter{google} # CSS-based block for Google text ads. Also removes a width limitation and the toolbar advertisement.
2653 <p><a name="FILTER-YAHOO" id="FILTER-YAHOO"></a></p>
2655 <table border="0" bgcolor="#E0E0E0" width="90%">
2658 <pre class="SCREEN">
2659 +filter{yahoo} # CSS-based block for Yahoo text ads. Also removes a width limitation.
2665 <p><a name="FILTER-MSN" id="FILTER-MSN"></a></p>
2667 <table border="0" bgcolor="#E0E0E0" width="90%">
2670 <pre class="SCREEN">
2671 +filter{msn} # CSS-based block for MSN text ads. Also removes tracking URLs and a width limitation.
2677 <p><a name="FILTER-BLOGSPOT" id="FILTER-BLOGSPOT"></a></p>
2679 <table border="0" bgcolor="#E0E0E0" width="90%">
2682 <pre class="SCREEN">
2683 +filter{blogspot} # Cleans up some Blogspot blogs. Read the fine print before using this.
2694 <h4 class="SECT3"><a name="FORCE-TEXT-MODE" id=
2695 "FORCE-TEXT-MODE">8.5.17. force-text-mode</a></h4>
2697 <div class="VARIABLELIST">
2699 <dt>Typical use:</dt>
2702 <p>Force <span class="APPLICATION">Privoxy</span> to treat a
2703 document as if it was in some kind of <span class=
2704 "emphasis"><i class="EMPHASIS">text</i></span> format.</p>
2710 <p>Declares a document as text, even if the <span class=
2711 "QUOTE">"Content-Type:"</span> isn't detected as such.</p>
2729 <p>As explained <tt class="LITERAL"><a href=
2730 "actions-file.html#FILTER">above</a></tt>, <span class=
2731 "APPLICATION">Privoxy</span> tries to only filter files that
2732 are in some kind of text format. The same restrictions apply to
2733 <tt class="LITERAL"><a href=
2734 "actions-file.html#CONTENT-TYPE-OVERWRITE">content-type-overwrite</a></tt>.
2735 <tt class="LITERAL">force-text-mode</tt> declares a document as
2736 text, without looking at the <span class=
2737 "QUOTE">"Content-Type:"</span> first.</p>
2739 <div class="WARNING">
2740 <table class="WARNING" border="1" width="90%">
2742 <td align="center"><b>Warning</b></td>
2747 <p>Think twice before activating this action. Filtering
2748 binary data with regular expressions can cause file
2756 <dt>Example usage:</dt>
2759 <table border="0" bgcolor="#E0E0E0" width="90%">
2762 <pre class="SCREEN">
2775 <h4 class="SECT3"><a name="FORWARD-OVERRIDE" id=
2776 "FORWARD-OVERRIDE">8.5.18. forward-override</a></h4>
2778 <div class="VARIABLELIST">
2780 <dt>Typical use:</dt>
2783 <p>Change the forwarding settings based on User-Agent or
2790 <p>Overrules the forward directives in the configuration
2797 <p>Parameterized.</p>
2805 <p><span class="QUOTE">"forward ."</span> to use a direct
2806 connection without any additional proxies.</p>
2810 <p><span class="QUOTE">"forward 127.0.0.1:8123"</span> to
2811 use the HTTP proxy listening at 127.0.0.1 port 8123.</p>
2815 <p><span class="QUOTE">"forward-socks4a 127.0.0.1:9050
2816 ."</span> to use the socks4a proxy listening at 127.0.0.1
2817 port 9050. Replace <span class=
2818 "QUOTE">"forward-socks4a"</span> with <span class=
2819 "QUOTE">"forward-socks4"</span> to use a socks4 connection
2820 (with local DNS resolution) instead, use <span class=
2821 "QUOTE">"forward-socks5"</span> for socks5 connections
2822 (with remote DNS resolution).</p>
2826 <p><span class="QUOTE">"forward-socks4a 127.0.0.1:9050
2827 proxy.example.org:8000"</span> to use the socks4a proxy
2828 listening at 127.0.0.1 port 9050 to reach the HTTP proxy
2829 listening at proxy.example.org port 8000. Replace
2830 <span class="QUOTE">"forward-socks4a"</span> with
2831 <span class="QUOTE">"forward-socks4"</span> to use a socks4
2832 connection (with local DNS resolution) instead, use
2833 <span class="QUOTE">"forward-socks5"</span> for socks5
2834 connections (with remote DNS resolution).</p>
2838 <p><span class="QUOTE">"forward-webserver
2839 127.0.0.1:80"</span> to use the HTTP server listening at
2840 127.0.0.1 port 80 without adjusting the request
2843 <p>This makes it more convenient to use Privoxy to make
2844 existing websites available as onion services as well.</p>
2846 <p>Many websites serve content with hardcoded URLs and
2847 can't be easily adjusted to change the domain based on the
2848 one used by the client.</p>
2850 <p>Putting Privoxy between Tor and the webserver (or an
2851 stunnel that forwards to the webserver) allows to rewrite
2852 headers and content to make client and server happy at the
2855 <p>Using Privoxy for webservers that are only reachable
2856 through onion addresses and whose location is supposed to
2857 be secret is not recommended and should not be necessary
2866 <p>This action takes parameters similar to the <a href=
2867 "config.html#FORWARDING">forward</a> directives in the
2868 configuration file, but without the URL pattern. It can be used
2869 as replacement, but normally it's only used in cases where
2870 matching based on the request URL isn't sufficient.</p>
2872 <div class="WARNING">
2873 <table class="WARNING" border="1" width="90%">
2875 <td align="center"><b>Warning</b></td>
2880 <p>Please read the description for the <a href=
2881 "config.html#FORWARDING">forward</a> directives before
2882 using this action. Forwarding to the wrong people will
2883 reduce your privacy and increase the chances of
2884 man-in-the-middle attacks.</p>
2886 <p>If the ports are missing or invalid, default values
2887 will be used. This might change in the future and you
2888 shouldn't rely on it. Otherwise incorrect syntax causes
2889 Privoxy to exit. Due to design limitations, invalid
2890 parameter syntax isn't detected until the action is
2891 used the first time.</p>
2894 "http://config.privoxy.org/show-url-info" target=
2895 "_top">show-url-info CGI page</a> to verify that your
2896 forward settings do what you thought the do.</p>
2903 <dt>Example usage:</dt>
2906 <table border="0" bgcolor="#E0E0E0" width="90%">
2909 <pre class="SCREEN">
2910 # Use an ssh tunnel for requests previously tagged as
2911 # <span class="QUOTE">"User-Agent: fetch libfetch/2.0"</span> and make sure
2912 # resuming downloads continues to work.
2914 # This way you can continue to use Tor for your normal browsing,
2915 # without overloading the Tor network with your FreeBSD ports updates
2916 # or downloads of bigger files like ISOs.
2918 # Note that HTTP headers are easy to fake and therefore their
2919 # values are as (un)trustworthy as your clients and users.
2920 {+forward-override{forward-socks5 10.0.0.2:2222 .} \
2921 -hide-if-modified-since \
2922 -overwrite-last-modified \
2924 TAG:^User-Agent: fetch libfetch/2\.0$
2936 <h4 class="SECT3"><a name="HANDLE-AS-EMPTY-DOCUMENT" id=
2937 "HANDLE-AS-EMPTY-DOCUMENT">8.5.19. handle-as-empty-document</a></h4>
2939 <div class="VARIABLELIST">
2941 <dt>Typical use:</dt>
2944 <p>Mark URLs that should be replaced by empty documents
2945 <span class="emphasis"><i class="EMPHASIS">if they get
2946 blocked</i></span></p>
2952 <p>This action alone doesn't do anything noticeable. It just
2953 marks URLs. If the <tt class="LITERAL"><a href=
2954 "actions-file.html#BLOCK">block</a></tt> action <span class=
2955 "emphasis"><i class="EMPHASIS">also applies</i></span>, the
2956 presence or absence of this mark decides whether an HTML
2957 <span class="QUOTE">"BLOCKED"</span> page, or an empty document
2958 will be sent to the client as a substitute for the blocked
2959 content. The <span class="emphasis"><i class=
2960 "EMPHASIS">empty</i></span> document isn't literally empty, but
2961 actually contains a single space.</p>
2979 <p>Some browsers complain about syntax errors if JavaScript
2980 documents are blocked with <span class=
2981 "APPLICATION">Privoxy's</span> default HTML page; this option
2982 can be used to silence them. And of course this action can also
2983 be used to eliminate the <span class=
2984 "APPLICATION">Privoxy</span> BLOCKED message in frames.</p>
2986 <p>The content type for the empty document can be specified
2987 with <tt class="LITERAL"><a href=
2988 "actions-file.html#CONTENT-TYPE-OVERWRITE">content-type-overwrite{}</a></tt>,
2989 but usually this isn't necessary.</p>
2992 <dt>Example usage:</dt>
2995 <table border="0" bgcolor="#E0E0E0" width="90%">
2998 <pre class="SCREEN">
2999 # Block all documents on example.org that end with ".js",
3000 # but send an empty document instead of the usual HTML message.
3001 {+block{Blocked JavaScript} +handle-as-empty-document}
3014 <h4 class="SECT3"><a name="HANDLE-AS-IMAGE" id=
3015 "HANDLE-AS-IMAGE">8.5.20. handle-as-image</a></h4>
3017 <div class="VARIABLELIST">
3019 <dt>Typical use:</dt>
3022 <p>Mark URLs as belonging to images (so they'll be replaced by
3023 images <span class="emphasis"><i class="EMPHASIS">if they do
3024 get blocked</i></span>, rather than HTML pages)</p>
3030 <p>This action alone doesn't do anything noticeable. It just
3031 marks URLs as images. If the <tt class="LITERAL"><a href=
3032 "actions-file.html#BLOCK">block</a></tt> action <span class=
3033 "emphasis"><i class="EMPHASIS">also applies</i></span>, the
3034 presence or absence of this mark decides whether an HTML
3035 <span class="QUOTE">"blocked"</span> page, or a replacement
3036 image (as determined by the <tt class="LITERAL"><a href=
3037 "actions-file.html#SET-IMAGE-BLOCKER">set-image-blocker</a></tt>
3038 action) will be sent to the client as a substitute for the
3039 blocked content.</p>
3057 <p>The below generic example section is actually part of
3058 <tt class="FILENAME">default.action</tt>. It marks all URLs
3059 with well-known image file name extensions as images and should
3062 <p>Users will probably only want to use the handle-as-image
3063 action in conjunction with <tt class="LITERAL"><a href=
3064 "actions-file.html#BLOCK">block</a></tt>, to block sources of
3065 banners, whose URLs don't reflect the file type, like in the
3066 second example section.</p>
3068 <p>Note that you cannot treat HTML pages as images in most
3069 cases. For instance, (in-line) ad frames require an HTML page
3070 to be sent, or they won't display properly. Forcing <tt class=
3071 "LITERAL">handle-as-image</tt> in this situation will not
3072 replace the ad frame with an image, but lead to error
3076 <dt>Example usage (sections):</dt>
3079 <table border="0" bgcolor="#E0E0E0" width="90%">
3082 <pre class="SCREEN">
3083 # Generic image extensions:
3086 /.*\.(gif|jpg|jpeg|png|bmp|ico)$
3088 # These don't look like images, but they're banners and should be
3089 # blocked as images:
3091 {+block{Nasty banners.} +handle-as-image}
3092 nasty-banner-server.example.com/junk.cgi\?output=trash
3103 <h4 class="SECT3"><a name="HIDE-ACCEPT-LANGUAGE" id=
3104 "HIDE-ACCEPT-LANGUAGE">8.5.21. hide-accept-language</a></h4>
3106 <div class="VARIABLELIST">
3108 <dt>Typical use:</dt>
3111 <p>Pretend to use different language settings.</p>
3117 <p>Deletes or replaces the <span class=
3118 "QUOTE">"Accept-Language:"</span> HTTP header in client
3125 <p>Parameterized.</p>
3131 <p>Keyword: <span class="QUOTE">"block"</span>, or any user
3138 <p>Faking the browser's language settings can be useful to make
3139 a foreign User-Agent set with <tt class="LITERAL"><a href=
3140 "actions-file.html#HIDE-USER-AGENT">hide-user-agent</a></tt>
3141 more believable.</p>
3143 <p>However some sites with content in different languages check
3144 the <span class="QUOTE">"Accept-Language:"</span> to decide
3145 which one to take by default. Sometimes it isn't possible to
3146 later switch to another language without changing the
3147 <span class="QUOTE">"Accept-Language:"</span> header first.</p>
3149 <p>Therefore it's a good idea to either only change the
3150 <span class="QUOTE">"Accept-Language:"</span> header to
3151 languages you understand, or to languages that aren't wide
3154 <p>Before setting the <span class=
3155 "QUOTE">"Accept-Language:"</span> header to a rare language,
3156 you should consider that it helps to make your requests unique
3157 and thus easier to trace. If you don't plan to change this
3158 header frequently, you should stick to a common language.</p>
3161 <dt>Example usage (section):</dt>
3164 <table border="0" bgcolor="#E0E0E0" width="90%">
3167 <pre class="SCREEN">
3168 # Pretend to use Canadian language settings.
3169 {+hide-accept-language{en-ca} \
3170 +hide-user-agent{Mozilla/5.0 (X11; U; OpenBSD i386; en-CA; rv:1.8.0.4) Gecko/20060628 Firefox/1.5.0.4} \
3183 <h4 class="SECT3"><a name="HIDE-CONTENT-DISPOSITION" id=
3184 "HIDE-CONTENT-DISPOSITION">8.5.22. hide-content-disposition</a></h4>
3186 <div class="VARIABLELIST">
3188 <dt>Typical use:</dt>
3191 <p>Prevent download menus for content you prefer to view inside
3198 <p>Deletes or replaces the <span class=
3199 "QUOTE">"Content-Disposition:"</span> HTTP header set by some
3206 <p>Parameterized.</p>
3212 <p>Keyword: <span class="QUOTE">"block"</span>, or any user
3219 <p>Some servers set the <span class=
3220 "QUOTE">"Content-Disposition:"</span> HTTP header for documents
3221 they assume you want to save locally before viewing them. The
3222 <span class="QUOTE">"Content-Disposition:"</span> header
3223 contains the file name the browser is supposed to use by
3226 <p>In most browsers that understand this header, it makes it
3227 impossible to <span class="emphasis"><i class="EMPHASIS">just
3228 view</i></span> the document, without downloading it first,
3229 even if it's just a simple text file or an image.</p>
3231 <p>Removing the <span class=
3232 "QUOTE">"Content-Disposition:"</span> header helps to prevent
3233 this annoyance, but some browsers additionally check the
3234 <span class="QUOTE">"Content-Type:"</span> header, before they
3235 decide if they can display a document without saving it first.
3236 In these cases, you have to change this header as well, before
3237 the browser stops displaying download menus.</p>
3239 <p>It is also possible to change the server's file name
3240 suggestion to another one, but in most cases it isn't worth the
3241 time to set it up.</p>
3243 <p>This action will probably be removed in the future, use
3244 server-header filters instead.</p>
3247 <dt>Example usage:</dt>
3250 <table border="0" bgcolor="#E0E0E0" width="90%">
3253 <pre class="SCREEN">
3254 # Disarm the download link in Sourceforge's patch tracker
3256 +content-type-overwrite{text/plain}\
3257 +hide-content-disposition{block} }
3258 .sourceforge.net/tracker/download\.php
3269 <h4 class="SECT3"><a name="HIDE-IF-MODIFIED-SINCE" id=
3270 "HIDE-IF-MODIFIED-SINCE">8.5.23. hide-if-modified-since</a></h4>
3272 <div class="VARIABLELIST">
3274 <dt>Typical use:</dt>
3277 <p>Prevent yet another way to track the user's steps between
3284 <p>Deletes the <span class="QUOTE">"If-Modified-Since:"</span>
3285 HTTP client header or modifies its value.</p>
3291 <p>Parameterized.</p>
3297 <p>Keyword: <span class="QUOTE">"block"</span>, or a user
3298 defined value that specifies a range of hours.</p>
3304 <p>Removing this header is useful for filter testing, where you
3305 want to force a real reload instead of getting status code
3306 <span class="QUOTE">"304"</span>, which would cause the browser
3307 to use a cached copy of the page.</p>
3309 <p>Instead of removing the header, <tt class=
3310 "LITERAL">hide-if-modified-since</tt> can also add or subtract
3311 a random amount of time to/from the header's value. You specify
3312 a range of minutes where the random factor should be chosen
3313 from and <span class="APPLICATION">Privoxy</span> does the
3314 rest. A negative value means subtracting, a positive value
3317 <p>Randomizing the value of the <span class=
3318 "QUOTE">"If-Modified-Since:"</span> makes it less likely that
3319 the server can use the time as a cookie replacement, but you
3320 will run into caching problems if the random range is too
3323 <p>It is a good idea to only use a small negative value and let
3324 <tt class="LITERAL"><a href=
3325 "actions-file.html#OVERWRITE-LAST-MODIFIED">overwrite-last-modified</a></tt>
3326 handle the greater changes.</p>
3328 <p>It is also recommended to use this action together with
3329 <tt class="LITERAL"><a href=
3330 "actions-file.html#CRUNCH-IF-NONE-MATCH">crunch-if-none-match</a></tt>,
3331 otherwise it's more or less pointless.</p>
3334 <dt>Example usage (section):</dt>
3337 <table border="0" bgcolor="#E0E0E0" width="90%">
3340 <pre class="SCREEN">
3341 # Let the browser revalidate but make tracking based on the time less likely.
3342 {+hide-if-modified-since{-60} \
3343 +overwrite-last-modified{randomize} \
3344 +crunch-if-none-match}
3356 <h4 class="SECT3"><a name="HIDE-FROM-HEADER" id=
3357 "HIDE-FROM-HEADER">8.5.24. hide-from-header</a></h4>
3359 <div class="VARIABLELIST">
3361 <dt>Typical use:</dt>
3364 <p>Keep your (old and ill) browser from telling web servers
3365 your email address</p>
3371 <p>Deletes any existing <span class="QUOTE">"From:"</span> HTTP
3372 header, or replaces it with the specified string.</p>
3378 <p>Parameterized.</p>
3384 <p>Keyword: <span class="QUOTE">"block"</span>, or any user
3391 <p>The keyword <span class="QUOTE">"block"</span> will
3392 completely remove the header (not to be confused with the
3393 <tt class="LITERAL"><a href=
3394 "actions-file.html#BLOCK">block</a></tt> action).</p>
3396 <p>Alternately, you can specify any value you prefer to be sent
3397 to the web server. If you do, it is a matter of fairness not to
3398 use any address that is actually used by a real person.</p>
3400 <p>This action is rarely needed, as modern web browsers don't
3401 send <span class="QUOTE">"From:"</span> headers anymore.</p>
3404 <dt>Example usage:</dt>
3407 <table border="0" bgcolor="#E0E0E0" width="90%">
3410 <pre class="SCREEN">
3411 +hide-from-header{block}
3417 <table border="0" bgcolor="#E0E0E0" width="90%">
3420 <pre class="SCREEN">
3421 +hide-from-header{spam-me-senseless@sittingduck.example.com}
3432 <h4 class="SECT3"><a name="HIDE-REFERRER" id="HIDE-REFERRER">8.5.25.
3433 hide-referrer</a></h4><a name="HIDE-REFERER" id="HIDE-REFERER"></a>
3435 <div class="VARIABLELIST">
3437 <dt>Typical use:</dt>
3440 <p>Conceal which link you followed to get to a particular
3447 <p>Deletes the <span class="QUOTE">"Referer:"</span> (sic) HTTP
3448 header from the client request, or replaces it with a forged
3455 <p>Parameterized.</p>
3463 <p><span class="QUOTE">"conditional-block"</span> to delete
3464 the header completely if the host has changed.</p>
3468 <p><span class="QUOTE">"conditional-forge"</span> to forge
3469 the header if the host has changed.</p>
3473 <p><span class="QUOTE">"block"</span> to delete the header
3474 unconditionally.</p>
3478 <p><span class="QUOTE">"forge"</span> to pretend to be
3479 coming from the homepage of the server we are talking
3484 <p>Any other string to set a user defined referrer.</p>
3492 <p><tt class="LITERAL">conditional-block</tt> is the only
3493 parameter, that isn't easily detected in the server's log file.
3494 If it blocks the referrer, the request will look like the
3495 visitor used a bookmark or typed in the address directly.</p>
3497 <p>Leaving the referrer unmodified for requests on the same
3498 host allows the server owner to see the visitor's <span class=
3499 "QUOTE">"click path"</span>, but in most cases she could also
3500 get that information by comparing other parts of the log file:
3501 for example the User-Agent if it isn't a very common one, or
3502 the user's IP address if it doesn't change between different
3505 <p>Always blocking the referrer, or using a custom one, can
3506 lead to failures on servers that check the referrer before they
3507 answer any requests, in an attempt to prevent their content
3508 from being embedded or linked to elsewhere.</p>
3510 <p>Both <tt class="LITERAL">conditional-block</tt> and
3511 <tt class="LITERAL">forge</tt> will work with referrer checks,
3512 as long as content and valid referring page are on the same
3513 host. Most of the time that's the case.</p>
3515 <p><tt class="LITERAL">hide-referer</tt> is an alternate
3516 spelling of <tt class="LITERAL">hide-referrer</tt> and the two
3517 can be can be freely substituted with each other. (<span class=
3518 "QUOTE">"referrer"</span> is the correct English spelling,
3519 however the HTTP specification has a bug - it requires it to be
3520 spelled as <span class="QUOTE">"referer"</span>.)</p>
3523 <dt>Example usage:</dt>
3526 <table border="0" bgcolor="#E0E0E0" width="90%">
3529 <pre class="SCREEN">
3530 +hide-referrer{forge}
3536 <table border="0" bgcolor="#E0E0E0" width="90%">
3539 <pre class="SCREEN">
3540 +hide-referrer{http://www.yahoo.com/}
3551 <h4 class="SECT3"><a name="HIDE-USER-AGENT" id=
3552 "HIDE-USER-AGENT">8.5.26. hide-user-agent</a></h4>
3554 <div class="VARIABLELIST">
3556 <dt>Typical use:</dt>
3559 <p>Try to conceal your type of browser and client operating
3566 <p>Replaces the value of the <span class=
3567 "QUOTE">"User-Agent:"</span> HTTP header in client requests
3568 with the specified value.</p>
3574 <p>Parameterized.</p>
3580 <p>Any user-defined string.</p>
3586 <div class="WARNING">
3587 <table class="WARNING" border="1" width="90%">
3589 <td align="center"><b>Warning</b></td>
3594 <p>This can lead to problems on web sites that depend
3595 on looking at this header in order to customize their
3596 content for different browsers (which, by the way, is
3597 <span class="emphasis"><i class=
3598 "EMPHASIS">NOT</i></span> the right thing to do: good
3599 web sites work browser-independently).</p>
3605 <p>Using this action in multi-user setups or wherever different
3606 types of browsers will access the same <span class=
3607 "APPLICATION">Privoxy</span> is <span class=
3608 "emphasis"><i class="EMPHASIS">not recommended</i></span>. In
3609 single-user, single-browser setups, you might use it to delete
3610 your OS version information from the headers, because it is an
3611 invitation to exploit known bugs for your OS. It is also
3612 occasionally useful to forge this in order to access sites that
3613 won't let you in otherwise (though there may be a good reason
3616 <p>More information on known user-agent strings can be found at
3617 <a href="http://www.user-agents.org/" target=
3618 "_top">http://www.user-agents.org/</a> and <a href=
3619 "http://en.wikipedia.org/wiki/User_agent" target=
3620 "_top">http://en.wikipedia.org/wiki/User_agent</a>.</p>
3623 <dt>Example usage:</dt>
3626 <table border="0" bgcolor="#E0E0E0" width="90%">
3629 <pre class="SCREEN">
3630 +hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}
3641 <h4 class="SECT3"><a name="LIMIT-CONNECT" id="LIMIT-CONNECT">8.5.27.
3642 limit-connect</a></h4>
3644 <div class="VARIABLELIST">
3646 <dt>Typical use:</dt>
3649 <p>Prevent abuse of <span class="APPLICATION">Privoxy</span> as
3650 a TCP proxy relay or disable SSL for untrusted sites</p>
3656 <p>Specifies to which ports HTTP CONNECT requests are
3663 <p>Parameterized.</p>
3669 <p>A comma-separated list of ports or port ranges (the latter
3670 using dashes, with the minimum defaulting to 0 and the maximum
3677 <p>By default, i.e. if no <tt class=
3678 "LITERAL">limit-connect</tt> action applies, <span class=
3679 "APPLICATION">Privoxy</span> allows HTTP CONNECT requests to
3680 all ports. Use <tt class="LITERAL">limit-connect</tt> if
3681 fine-grained control is desired for some or all
3684 <p>The CONNECT methods exists in HTTP to allow access to secure
3685 websites (<span class="QUOTE">"https://"</span> URLs) through
3686 proxies. It works very simply: the proxy connects to the server
3687 on the specified port, and then short-circuits its connections
3688 to the client and to the remote server. This means
3689 CONNECT-enabled proxies can be used as TCP relays very
3692 <p><span class="APPLICATION">Privoxy</span> relays HTTPS
3693 traffic without seeing the decoded content. Websites can
3694 leverage this limitation to circumvent <span class=
3695 "APPLICATION">Privoxy</span>'s filters. By specifying an
3696 invalid port range you can disable HTTPS entirely.</p>
3699 <dt>Example usages:</dt>
3702 <table border="0" bgcolor="#E0E0E0" width="90%">
3705 <pre class="SCREEN">
3706 +limit-connect{443} # Port 443 is OK.
3707 +limit-connect{80,443} # Ports 80 and 443 are OK.
3708 +limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
3709 +limit-connect{-} # All ports are OK
3710 +limit-connect{,} # No HTTPS/SSL traffic is allowed
3721 <h4 class="SECT3"><a name="LIMIT-COOKIE-LIFETIME" id=
3722 "LIMIT-COOKIE-LIFETIME">8.5.28. limit-cookie-lifetime</a></h4>
3724 <div class="VARIABLELIST">
3726 <dt>Typical use:</dt>
3729 <p>Limit the lifetime of HTTP cookies to a couple of minutes or
3736 <p>Overwrites the expires field in Set-Cookie server headers if
3737 it's above the specified limit.</p>
3743 <p>Parameterized.</p>
3749 <p>The lifetime limit in minutes, or 0.</p>
3755 <p>This action reduces the lifetime of HTTP cookies coming from
3756 the server to the specified number of minutes, starting from
3757 the time the cookie passes Privoxy.</p>
3759 <p>Cookies with a lifetime below the limit are not modified.
3760 The lifetime of session cookies is set to the specified
3763 <p>The effect of this action depends on the server.</p>
3765 <p>In case of servers which refresh their cookies with each
3766 response (or at least frequently), the lifetime limit set by
3767 this action is updated as well. Thus, a session associated with
3768 the cookie continues to work with this action enabled, as long
3769 as a new request is made before the last limit set is
3772 <p>However, some servers send their cookies once, with a
3773 lifetime of several years (the year 2037 is a popular choice),
3774 and do not refresh them until a certain event in the future,
3775 for example the user logging out. In this case this action may
3776 limit the absolute lifetime of the session, even if requests
3777 are made frequently.</p>
3779 <p>If the parameter is <span class="QUOTE">"0"</span>, this
3780 action behaves like <tt class="LITERAL"><a href=
3781 "actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</a></tt>.</p>
3784 <dt>Example usages:</dt>
3787 <table border="0" bgcolor="#E0E0E0" width="90%">
3790 <pre class="SCREEN">
3791 +limit-cookie-lifetime{60}
3803 <h4 class="SECT3"><a name="PREVENT-COMPRESSION" id=
3804 "PREVENT-COMPRESSION">8.5.29. prevent-compression</a></h4>
3806 <div class="VARIABLELIST">
3808 <dt>Typical use:</dt>
3811 <p>Ensure that servers send the content uncompressed, so it can
3812 be passed through <tt class="LITERAL"><a href=
3813 "actions-file.html#FILTER">filter</a></tt>s.</p>
3819 <p>Removes the Accept-Encoding header which can be used to ask
3820 for compressed transfer.</p>
3838 <p>More and more websites send their content compressed by
3839 default, which is generally a good idea and saves bandwidth.
3840 But the <tt class="LITERAL"><a href=
3841 "actions-file.html#FILTER">filter</a></tt> and <tt class=
3843 "actions-file.html#DEANIMATE-GIFS">deanimate-gifs</a></tt>
3844 actions need access to the uncompressed data.</p>
3846 <p>When compiled with zlib support (available since
3847 <span class="APPLICATION">Privoxy</span> 3.0.7), content that
3848 should be filtered is decompressed on-the-fly and you don't
3849 have to worry about this action. If you are using an older
3850 <span class="APPLICATION">Privoxy</span> version, or one that
3851 hasn't been compiled with zlib support, this action can be used
3852 to convince the server to send the content uncompressed.</p>
3854 <p>Most text-based instances compress very well, the size is
3855 seldom decreased by less than 50%, for markup-heavy instances
3856 like news feeds saving more than 90% of the original size isn't
3859 <p>Not using compression will therefore slow down the transfer,
3860 and you should only enable this action if you really need it.
3861 As of <span class="APPLICATION">Privoxy</span> 3.0.7 it's
3862 disabled in all predefined action settings.</p>
3864 <p>Note that some (rare) ill-configured sites don't handle
3865 requests for uncompressed documents correctly. Broken PHP
3866 applications tend to send an empty document body, some IIS
3867 versions only send the beginning of the content. If you enable
3868 <tt class="LITERAL">prevent-compression</tt> per default, you
3869 might want to add exceptions for those sites. See the example
3870 for how to do that.</p>
3873 <dt>Example usage (sections):</dt>
3876 <table border="0" bgcolor="#E0E0E0" width="90%">
3879 <pre class="SCREEN">
3880 # Selectively turn off compression, and enable a filter
3882 { +filter{tiny-textforms} +prevent-compression }
3883 # Match only these sites
3888 # Or instead, we could set a universal default:
3890 { +prevent-compression }
3893 # Then maybe make exceptions for broken sites:
3895 { -prevent-compression }
3907 <h4 class="SECT3"><a name="OVERWRITE-LAST-MODIFIED" id=
3908 "OVERWRITE-LAST-MODIFIED">8.5.30. overwrite-last-modified</a></h4>
3910 <div class="VARIABLELIST">
3912 <dt>Typical use:</dt>
3915 <p>Prevent yet another way to track the user's steps between
3922 <p>Deletes the <span class="QUOTE">"Last-Modified:"</span> HTTP
3923 server header or modifies its value.</p>
3929 <p>Parameterized.</p>
3935 <p>One of the keywords: <span class="QUOTE">"block"</span>,
3936 <span class="QUOTE">"reset-to-request-time"</span> and
3937 <span class="QUOTE">"randomize"</span></p>
3943 <p>Removing the <span class="QUOTE">"Last-Modified:"</span>
3944 header is useful for filter testing, where you want to force a
3945 real reload instead of getting status code <span class=
3946 "QUOTE">"304"</span>, which would cause the browser to reuse
3947 the old version of the page.</p>
3949 <p>The <span class="QUOTE">"randomize"</span> option overwrites
3950 the value of the <span class="QUOTE">"Last-Modified:"</span>
3951 header with a randomly chosen time between the original value
3952 and the current time. In theory the server could send each
3953 document with a different <span class=
3954 "QUOTE">"Last-Modified:"</span> header to track visits without
3955 using cookies. <span class="QUOTE">"Randomize"</span> makes it
3956 impossible and the browser can still revalidate cached
3959 <p><span class="QUOTE">"reset-to-request-time"</span>
3960 overwrites the value of the <span class=
3961 "QUOTE">"Last-Modified:"</span> header with the current time.
3962 You could use this option together with <tt class=
3964 "actions-file.html#HIDE-IF-MODIFIED-SINCE">hide-if-modified-since</a></tt>
3965 to further customize your random range.</p>
3967 <p>The preferred parameter here is <span class=
3968 "QUOTE">"randomize"</span>. It is safe to use, as long as the
3969 time settings are more or less correct. If the server sets the
3970 <span class="QUOTE">"Last-Modified:"</span> header to the time
3971 of the request, the random range becomes zero and the value
3972 stays the same. Therefore you should later randomize it a
3973 second time with <tt class="LITERAL"><a href=
3974 "actions-file.html#HIDE-IF-MODIFIED-SINCE">hided-if-modified-since</a></tt>,
3975 just to be sure.</p>
3977 <p>It is also recommended to use this action together with
3978 <tt class="LITERAL"><a href=
3979 "actions-file.html#CRUNCH-IF-NONE-MATCH">crunch-if-none-match</a></tt>.</p>
3982 <dt>Example usage:</dt>
3985 <table border="0" bgcolor="#E0E0E0" width="90%">
3988 <pre class="SCREEN">
3989 # Let the browser revalidate without being tracked across sessions
3990 { +hide-if-modified-since{-60} \
3991 +overwrite-last-modified{randomize} \
3992 +crunch-if-none-match}
4004 <h4 class="SECT3"><a name="REDIRECT" id="REDIRECT">8.5.31.
4007 <div class="VARIABLELIST">
4009 <dt>Typical use:</dt>
4012 <p>Redirect requests to other sites.</p>
4018 <p>Convinces the browser that the requested document has been
4019 moved to another location and the browser should get it from
4026 <p>Parameterized</p>
4032 <p>An absolute URL or a single pcrs command.</p>
4038 <p>Requests to which this action applies are answered with a
4039 HTTP redirect to URLs of your choosing. The new URL is either
4040 provided as parameter, or derived by applying a single pcrs
4041 command to the original URL.</p>
4043 <p>The syntax for pcrs commands is documented in the <a href=
4044 "filter-file.html">filter file</a> section.</p>
4046 <p>Requests can't be blocked and redirected at the same time,
4047 applying this action together with <tt class="LITERAL"><a href=
4048 "actions-file.html#BLOCK">block</a></tt> is a configuration
4049 error. Currently the request is blocked and an error message
4050 logged, the behavior may change in the future and result in
4051 Privoxy rejecting the action file.</p>
4053 <p>This action can be combined with <tt class=
4054 "LITERAL"><a href="actions-file.html#FAST-REDIRECTS">fast-redirects{check-decoded-url}</a></tt>
4055 to redirect to a decoded version of a rewritten URL.</p>
4057 <p>Use this action carefully, make sure not to create
4058 redirection loops and be aware that using your own redirects
4059 might make it possible to fingerprint your requests.</p>
4061 <p>In case of problems with your redirects, or simply to watch
4062 them working, enable <a href="config.html#DEBUG">debug
4066 <dt>Example usages:</dt>
4069 <table border="0" bgcolor="#E0E0E0" width="90%">
4072 <pre class="SCREEN">
4073 # Replace example.com's style sheet with another one
4074 { +redirect{http://localhost/css-replacements/example.com.css} }
4075 example.com/stylesheet\.css
4077 # Create a short, easy to remember nickname for a favorite site
4078 # (relies on the browser to accept and forward invalid URLs to <span class=
4079 "APPLICATION">Privoxy</span>)
4080 { +redirect{http://www.privoxy.org/user-manual/actions-file.html} }
4083 # Always use the expanded view for Undeadly.org articles
4084 # (Note the $ at the end of the URL pattern to make sure
4085 # the request for the rewritten URL isn't redirected as well)
4086 {+redirect{s@$@&mode=expanded@}}
4087 undeadly.org/cgi\?action=article&sid=\d*$
4089 # Redirect Google search requests to MSN
4090 {+redirect{s@^http://[^/]*/search\?q=([^&]*).*@http://search.msn.com/results.aspx?q=$1@}}
4093 # Redirect MSN search requests to Yahoo
4094 {+redirect{s@^http://[^/]*/results\.aspx\?q=([^&]*).*@http://search.yahoo.com/search?p=$1@}}
4095 search.msn.com//results\.aspx\?q=
4097 # Redirect http://example.com/&bla=fasel&toChange=foo (and any other value but "bar")
4098 # to http://example.com/&bla=fasel&toChange=bar
4100 # The URL pattern makes sure that the following request isn't redirected again.
4101 {+redirect{s@toChange=[^&]+@toChange=bar@}}
4102 example.com/.*toChange=(?!bar)
4104 # Add a shortcut to look up illumos bugs
4105 {+redirect{s@^http://i([0-9]+)/.*@https://www.illumos.org/issues/$1@}}
4106 # Redirected URL = http://i4974/
4107 # Redirect Destination = https://www.illumos.org/issues/4974
4108 i[0-9][0-9][0-9][0-9]*/
4110 # Redirect remote requests for this manual
4111 # to the local version delivered by Privoxy
4112 {+redirect{s@^http://www@http://config@}}
4113 www.privoxy.org/user-manual/
4124 <h4 class="SECT3"><a name="SERVER-HEADER-FILTER" id=
4125 "SERVER-HEADER-FILTER">8.5.32. server-header-filter</a></h4>
4127 <div class="VARIABLELIST">
4129 <dt>Typical use:</dt>
4132 <p>Rewrite or remove single server headers.</p>
4138 <p>All server headers to which this action applies are filtered
4139 on-the-fly through the specified regular expression based
4152 <p>The name of a server-header filter, as defined in one of the
4153 <a href="filter-file.html">filter files</a>.</p>
4159 <p>Server-header filters are applied to each header on its own,
4160 not to all at once. This makes it easier to diagnose problems,
4161 but on the downside you can't write filters that only change
4162 header x if header y's value is z. You can do that by using
4165 <p>Server-header filters are executed after the other header
4166 actions have finished and use their output as input.</p>
4168 <p>Please refer to the <a href="filter-file.html">filter file
4169 chapter</a> to learn which server-header filters are available
4170 by default, and how to create your own.</p>
4173 <dt>Example usage (section):</dt>
4176 <table border="0" bgcolor="#E0E0E0" width="90%">
4179 <pre class="SCREEN">
4180 {+server-header-filter{html-to-xml}}
4181 example.org/xml-instance-that-is-delivered-as-html
4183 {+server-header-filter{xml-to-html}}
4184 example.org/instance-that-is-delivered-as-xml-but-is-not
4196 <h4 class="SECT3"><a name="SERVER-HEADER-TAGGER" id=
4197 "SERVER-HEADER-TAGGER">8.5.33. server-header-tagger</a></h4>
4199 <div class="VARIABLELIST">
4201 <dt>Typical use:</dt>
4204 <p>Enable or disable filters based on the Content-Type
4211 <p>Server headers to which this action applies are filtered
4212 on-the-fly through the specified regular expression based
4213 substitutions, the result is used as tag.</p>
4225 <p>The name of a server-header tagger, as defined in one of the
4226 <a href="filter-file.html">filter files</a>.</p>
4232 <p>Server-header taggers are applied to each header on its own,
4233 and as the header isn't modified, each tagger <span class=
4234 "QUOTE">"sees"</span> the original.</p>
4236 <p>Server-header taggers are executed before all other header
4237 actions that modify server headers. Their tags can be used to
4238 control all of the other server-header actions, the content
4239 filters and the crunch actions (<a href=
4240 "actions-file.html#REDIRECT">redirect</a> and <a href=
4241 "actions-file.html#BLOCK">block</a>).</p>
4243 <p>Obviously crunching based on tags created by server-header
4244 taggers doesn't prevent the request from showing up in the
4245 server's log file.</p>
4248 <dt>Example usage (section):</dt>
4251 <table border="0" bgcolor="#E0E0E0" width="90%">
4254 <pre class="SCREEN">
4255 # Tag every request with the content type declared by the server
4256 {+server-header-tagger{content-type}}
4259 # If the response has a tag starting with 'image/' enable an external
4260 # filter that only applies to images.
4262 # Note that the filter is not available by default, it's just a
4263 # <tt class="LITERAL"><a href=
4264 "filter-file.html#EXTERNAL-FILTER-SYNTAX">silly example</a></tt>.
4265 {+external-filter{rotate-image} +force-text-mode}
4278 <h4 class="SECT3"><a name="SESSION-COOKIES-ONLY" id=
4279 "SESSION-COOKIES-ONLY">8.5.34. session-cookies-only</a></h4>
4281 <div class="VARIABLELIST">
4283 <dt>Typical use:</dt>
4286 <p>Allow only temporary <span class="QUOTE">"session"</span>
4287 cookies (for the current browser session <span class=
4288 "emphasis"><i class="EMPHASIS">only</i></span>).</p>
4294 <p>Deletes the <span class="QUOTE">"expires"</span> field from
4295 <span class="QUOTE">"Set-Cookie:"</span> server headers. Most
4296 browsers will not store such cookies permanently and forget
4297 them in between sessions.</p>
4315 <p>This is less strict than <tt class="LITERAL"><a href=
4316 "actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</a></tt>
4317 / <tt class="LITERAL"><a href=
4318 "actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</a></tt>
4319 and allows you to browse websites that insist or rely on
4320 setting cookies, without compromising your privacy too
4323 <p>Most browsers will not permanently store cookies that have
4324 been processed by <tt class="LITERAL">session-cookies-only</tt>
4325 and will forget about them between sessions. This makes
4326 profiling cookies useless, but won't break sites which require
4327 cookies so that you can log in for transactions. This is
4328 generally turned on for all sites, and is the recommended
4331 <p>It makes <span class="emphasis"><i class="EMPHASIS">no sense
4332 at all</i></span> to use <tt class=
4333 "LITERAL">session-cookies-only</tt> together with <tt class=
4335 "actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</a></tt>
4336 or <tt class="LITERAL"><a href=
4337 "actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</a></tt>.
4338 If you do, cookies will be plainly killed.</p>
4340 <p>Note that it is up to the browser how it handles such
4341 cookies without an <span class="QUOTE">"expires"</span> field.
4342 If you use an exotic browser, you might want to try it out to
4345 <p>This setting also has no effect on cookies that may have
4346 been stored previously by the browser before starting
4347 <span class="APPLICATION">Privoxy</span>. These would have to
4348 be removed manually.</p>
4350 <p><span class="APPLICATION">Privoxy</span> also uses the
4352 "actions-file.html#FILTER-CONTENT-COOKIES">content-cookies
4353 filter</a> to block some types of cookies. Content cookies are
4354 not effected by <tt class=
4355 "LITERAL">session-cookies-only</tt>.</p>
4358 <dt>Example usage:</dt>
4361 <table border="0" bgcolor="#E0E0E0" width="90%">
4364 <pre class="SCREEN">
4365 +session-cookies-only
4376 <h4 class="SECT3"><a name="SET-IMAGE-BLOCKER" id=
4377 "SET-IMAGE-BLOCKER">8.5.35. set-image-blocker</a></h4>
4379 <div class="VARIABLELIST">
4381 <dt>Typical use:</dt>
4384 <p>Choose the replacement for blocked images</p>
4390 <p>This action alone doesn't do anything noticeable. If
4391 <span class="emphasis"><i class="EMPHASIS">both</i></span>
4392 <tt class="LITERAL"><a href=
4393 "actions-file.html#BLOCK">block</a></tt> <span class=
4394 "emphasis"><i class="EMPHASIS">and</i></span> <tt class=
4396 "actions-file.html#HANDLE-AS-IMAGE">handle-as-image</a></tt>
4397 <span class="emphasis"><i class="EMPHASIS">also</i></span>
4398 apply, i.e. if the request is to be blocked as an image,
4399 <span class="emphasis"><i class="EMPHASIS">then</i></span> the
4400 parameter of this action decides what will be sent as a
4407 <p>Parameterized.</p>
4415 <p><span class="QUOTE">"pattern"</span> to send a built-in
4416 checkerboard pattern image. The image is visually decent,
4417 scales very well, and makes it obvious where banners were
4422 <p><span class="QUOTE">"blank"</span> to send a built-in
4423 transparent image. This makes banners disappear completely,
4424 but makes it hard to detect where <span class=
4425 "APPLICATION">Privoxy</span> has blocked images on a given
4426 page and complicates troubleshooting if <span class=
4427 "APPLICATION">Privoxy</span> has blocked innocent images,
4428 like navigation icons.</p>
4432 <p><span class="QUOTE">"<tt class=
4433 "REPLACEABLE"><i>target-url</i></tt>"</span> to send a
4434 redirect to <tt class="REPLACEABLE"><i>target-url</i></tt>.
4435 You can redirect to any image anywhere, even in your local
4436 filesystem via <span class="QUOTE">"file:///"</span> URL.
4437 (But note that not all browsers support redirecting to a
4438 local file system).</p>
4440 <p>A good application of redirects is to use special
4441 <span class="APPLICATION">Privoxy</span>-built-in URLs,
4442 which send the built-in images, as <tt class=
4443 "REPLACEABLE"><i>target-url</i></tt>. This has the same
4444 visual effect as specifying <span class=
4445 "QUOTE">"blank"</span> or <span class=
4446 "QUOTE">"pattern"</span> in the first place, but enables
4447 your browser to cache the replacement image, instead of
4448 requesting it over and over again.</p>
4456 <p>The URLs for the built-in images are <span class=
4457 "QUOTE">"http://config.privoxy.org/send-banner?type=<tt class=
4458 "REPLACEABLE"><i>type</i></tt>"</span>, where <tt class=
4459 "REPLACEABLE"><i>type</i></tt> is either <span class=
4460 "QUOTE">"blank"</span> or <span class=
4461 "QUOTE">"pattern"</span>.</p>
4463 <p>There is a third (advanced) type, called <span class=
4464 "QUOTE">"auto"</span>. It is <span class="emphasis"><i class=
4465 "EMPHASIS">NOT</i></span> to be used in <tt class=
4466 "LITERAL">set-image-blocker</tt>, but meant for use from
4467 <a href="filter-file.html">filters</a>. Auto will select the
4468 type of image that would have applied to the referring page,
4469 had it been an image.</p>
4472 <dt>Example usage:</dt>
4475 <p>Built-in pattern:</p>
4477 <table border="0" bgcolor="#E0E0E0" width="90%">
4480 <pre class="SCREEN">
4481 +set-image-blocker{pattern}
4487 <p>Redirect to the BSD daemon:</p>
4489 <table border="0" bgcolor="#E0E0E0" width="90%">
4492 <pre class="SCREEN">
4493 +set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}
4499 <p>Redirect to the built-in pattern for better caching:</p>
4501 <table border="0" bgcolor="#E0E0E0" width="90%">
4504 <pre class="SCREEN">
4505 +set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}
4516 <h3 class="SECT3"><a name="SUMMARY" id="SUMMARY">8.5.36.
4519 <p>Note that many of these actions have the potential to cause a page
4520 to misbehave, possibly even not to display at all. There are many
4521 ways a site designer may choose to design his site, and what HTTP
4522 header content, and other criteria, he may depend on. There is no way
4523 to have hard and fast rules for all sites. See the <a href=
4524 "appendix.html#ACTIONSANAT">Appendix</a> for a brief example on
4525 troubleshooting actions.</p>
4530 <h2 class="SECT2"><a name="ALIASES" id="ALIASES">8.6. Aliases</a></h2>
4532 <p>Custom <span class="QUOTE">"actions"</span>, known to <span class=
4533 "APPLICATION">Privoxy</span> as <span class="QUOTE">"aliases"</span>,
4534 can be defined by combining other actions. These can in turn be invoked
4535 just like the built-in actions. Currently, an alias name can contain
4536 any character except space, tab, <span class="QUOTE">"="</span>,
4537 <span class="QUOTE">"{"</span> and <span class="QUOTE">"}"</span>, but
4538 we <span class="emphasis"><i class="EMPHASIS">strongly
4539 recommend</i></span> that you only use <span class="QUOTE">"a"</span>
4540 to <span class="QUOTE">"z"</span>, <span class="QUOTE">"0"</span> to
4541 <span class="QUOTE">"9"</span>, <span class="QUOTE">"+"</span>, and
4542 <span class="QUOTE">"-"</span>. Alias names are not case sensitive, and
4543 are not required to start with a <span class="QUOTE">"+"</span> or
4544 <span class="QUOTE">"-"</span> sign, since they are merely textually
4547 <p>Aliases can be used throughout the actions file, but they
4548 <span class="emphasis"><i class="EMPHASIS">must be defined in a special
4549 section at the top of the file!</i></span> And there can only be one
4550 such section per actions file. Each actions file may have its own alias
4551 section, and the aliases defined in it are only visible within that
4554 <p>There are two main reasons to use aliases: One is to save typing for
4555 frequently used combinations of actions, the other one is a gain in
4556 flexibility: If you decide once how you want to handle shops by
4557 defining an alias called <span class="QUOTE">"shop"</span>, you can
4558 later change your policy on shops in <span class="emphasis"><i class=
4559 "EMPHASIS">one</i></span> place, and your changes will take effect
4560 everywhere in the actions file where the <span class=
4561 "QUOTE">"shop"</span> alias is used. Calling aliases by their purpose
4562 also makes your actions files more readable.</p>
4564 <p>Currently, there is one big drawback to using aliases, though:
4565 <span class="APPLICATION">Privoxy</span>'s built-in web-based action
4566 file editor honors aliases when reading the actions files, but it
4567 expands them before writing. So the effects of your aliases are of
4568 course preserved, but the aliases themselves are lost when you edit
4569 sections that use aliases with it.</p>
4571 <p>Now let's define some aliases...</p>
4573 <table border="0" bgcolor="#E0E0E0" width="100%">
4576 <pre class="SCREEN">
4577 # Useful custom aliases we can use later.
4579 # Note the (required!) section header line and that this section
4580 # must be at the top of the actions file!
4584 # These aliases just save typing later:
4585 # (Note that some already use other aliases!)
4587 +crunch-all-cookies = +<a href=
4588 "actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</a> +<a href="actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</a>
4589 -crunch-all-cookies = -<a href=
4590 "actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</a> -<a href="actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</a>
4591 +block-as-image = +block{Blocked image.} +handle-as-image
4592 allow-all-cookies = -crunch-all-cookies -<a href=
4593 "actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</a> -<a href=
4594 "actions-file.html#FILTER-CONTENT-COOKIES">filter{content-cookies}</a>
4596 # These aliases define combinations of actions
4597 # that are useful for certain types of sites:
4599 fragile = -<a href="actions-file.html#BLOCK">block</a> -<a href=
4600 "actions-file.html#FILTER">filter</a> -crunch-all-cookies -<a href=
4601 "actions-file.html#FAST-REDIRECTS">fast-redirects</a> -<a href=
4602 "actions-file.html#HIDE-REFERER">hide-referrer</a> -<a href=
4603 "actions-file.html#PREVENT-COMPRESSION">prevent-compression</a>
4605 shop = -crunch-all-cookies -<a href=
4606 "actions-file.html#FILTER-ALL-POPUPS">filter{all-popups}</a>
4608 # Short names for other aliases, for really lazy people ;-)
4610 c0 = +crunch-all-cookies
4611 c1 = -crunch-all-cookies
4617 <p>...and put them to use. These sections would appear in the lower
4618 part of an actions file and define exceptions to the default actions
4619 (as specified further up for the <span class="QUOTE">"/"</span>
4622 <table border="0" bgcolor="#E0E0E0" width="100%">
4625 <pre class="SCREEN">
4626 # These sites are either very complex or very keen on
4627 # user data and require minimal interference to work:
4630 .office.microsoft.com
4631 .windowsupdate.microsoft.com
4632 # Gmail is really mail.google.com, not gmail.com
4636 # Allow cookies (for setting and retrieving your customer data)
4640 .worldpay.com # for quietpc.com
4643 # These shops require pop-ups:
4645 {-filter{all-popups} -filter{unsolicited-popups}}
4653 <p>Aliases like <span class="QUOTE">"shop"</span> and <span class=
4654 "QUOTE">"fragile"</span> are typically used for <span class=
4655 "QUOTE">"problem"</span> sites that require more than one action to be
4656 disabled in order to function properly.</p>
4660 <h2 class="SECT2"><a name="ACT-EXAMPLES" id="ACT-EXAMPLES">8.7. Actions
4661 Files Tutorial</a></h2>
4663 <p>The above chapters have shown <a href="actions-file.html">which
4664 actions files there are and how they are organized</a>, how actions are
4665 <a href="actions-file.html#ACTIONS">specified</a> and <a href=
4666 "actions-file.html#ACTIONS-APPLY">applied to URLs</a>, how <a href=
4667 "actions-file.html#AF-PATTERNS">patterns</a> work, and how to define
4668 and use <a href="actions-file.html#ALIASES">aliases</a>. Now, let's
4669 look at an example <tt class="FILENAME">match-all.action</tt>,
4670 <tt class="FILENAME">default.action</tt> and <tt class=
4671 "FILENAME">user.action</tt> file and see how all these pieces come
4675 <h3 class="SECT3"><a name="MATCH-ALL" id="MATCH-ALL">8.7.1.
4676 match-all.action</a></h3>
4678 <p>Remember <span class="emphasis"><i class="EMPHASIS">all actions
4679 are disabled when matching starts</i></span>, so we have to
4680 explicitly enable the ones we want.</p>
4682 <p>While the <tt class="FILENAME">match-all.action</tt> file only
4683 contains a single section, it is probably the most important one. It
4684 has only one pattern, <span class="QUOTE">"<tt class=
4685 "LITERAL">/</tt>"</span>, but this pattern <a href=
4686 "actions-file.html#AF-PATTERNS">matches all URLs</a>. Therefore, the
4687 set of actions used in this <span class="QUOTE">"default"</span>
4688 section <span class="emphasis"><i class="EMPHASIS">will be applied to
4689 all requests as a start</i></span>. It can be partly or wholly
4690 overridden by other actions files like <tt class=
4691 "FILENAME">default.action</tt> and <tt class=
4692 "FILENAME">user.action</tt>, but it will still be largely responsible
4693 for your overall browsing experience.</p>
4695 <p>Again, at the start of matching, all actions are disabled, so
4696 there is no need to disable any actions here. (Remember: a
4697 <span class="QUOTE">"+"</span> preceding the action name enables the
4698 action, a <span class="QUOTE">"-"</span> disables!). Also note how
4699 this long line has been made more readable by splitting it into
4700 multiple lines with line continuation.</p>
4702 <table border="0" bgcolor="#E0E0E0" width="100%">
4705 <pre class="SCREEN">
4708 "actions-file.html#CHANGE-X-FORWARDED-FOR">change-x-forwarded-for{block}</a> \
4709 +<a href="actions-file.html#HIDE-FROM-HEADER">hide-from-header{block}</a> \
4711 "actions-file.html#SET-IMAGE-BLOCKER">set-image-blocker{pattern}</a> \
4720 <p>The default behavior is now set.</p>
4724 <h3 class="SECT3"><a name="DEFAULT-ACTION" id="DEFAULT-ACTION">8.7.2.
4725 default.action</a></h3>
4727 <p>If you aren't a developer, there's no need for you to edit the
4728 <tt class="FILENAME">default.action</tt> file. It is maintained by
4729 the <span class="APPLICATION">Privoxy</span> developers and if you
4730 disagree with some of the sections, you should overrule them in your
4731 <tt class="FILENAME">user.action</tt>.</p>
4733 <p>Understanding the <tt class="FILENAME">default.action</tt> file
4734 can help you with your <tt class="FILENAME">user.action</tt>,
4737 <p>The first section in this file is a special section for internal
4738 use that prevents older <span class="APPLICATION">Privoxy</span>
4739 versions from reading the file:</p>
4741 <table border="0" bgcolor="#E0E0E0" width="100%">
4744 <pre class="SCREEN">
4745 ##########################################################################
4746 # Settings -- Don't change! For internal Privoxy use ONLY.
4747 ##########################################################################
4749 for-privoxy-version=3.0.11
4755 <p>After that comes the (optional) alias section. We'll use the
4756 example section from the above <a href=
4757 "actions-file.html#ALIASES">chapter on aliases</a>, that also
4758 explains why and how aliases are used:</p>
4760 <table border="0" bgcolor="#E0E0E0" width="100%">
4763 <pre class="SCREEN">
4764 ##########################################################################
4766 ##########################################################################
4769 # These aliases just save typing later:
4770 # (Note that some already use other aliases!)
4772 +crunch-all-cookies = +<a href=
4773 "actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</a> +<a href="actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</a>
4774 -crunch-all-cookies = -<a href=
4775 "actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</a> -<a href="actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</a>
4776 +block-as-image = +block{Blocked image.} +handle-as-image
4777 mercy-for-cookies = -crunch-all-cookies -<a href=
4778 "actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</a> -<a href=
4779 "actions-file.html#FILTER-CONTENT-COOKIES">filter{content-cookies}</a>
4781 # These aliases define combinations of actions
4782 # that are useful for certain types of sites:
4784 fragile = -<a href="actions-file.html#BLOCK">block</a> -<a href=
4785 "actions-file.html#FILTER">filter</a> -crunch-all-cookies -<a href=
4786 "actions-file.html#FAST-REDIRECTS">fast-redirects</a> -<a href=
4787 "actions-file.html#HIDE-REFERER">hide-referrer</a>
4788 shop = -crunch-all-cookies -<a href=
4789 "actions-file.html#FILTER-ALL-POPUPS">filter{all-popups}</a>
4795 <p>The first of our specialized sections is concerned with
4796 <span class="QUOTE">"fragile"</span> sites, i.e. sites that require
4797 minimum interference, because they are either very complex or very
4798 keen on tracking you (and have mechanisms in place that make them
4799 unusable for people who avoid being tracked). We will simply use our
4800 pre-defined <tt class="LITERAL">fragile</tt> alias instead of stating
4801 the list of actions explicitly:</p>
4803 <table border="0" bgcolor="#E0E0E0" width="100%">
4806 <pre class="SCREEN">
4807 ##########################################################################
4808 # Exceptions for sites that'll break under the default action set:
4809 ##########################################################################
4811 # "Fragile" Use a minimum set of actions for these sites (see alias above):
4814 .office.microsoft.com # surprise, surprise!
4815 .windowsupdate.microsoft.com
4822 <p>Shopping sites are not as fragile, but they typically require
4823 cookies to log in, and pop-up windows for shopping carts or item
4824 details. Again, we'll use a pre-defined alias:</p>
4826 <table border="0" bgcolor="#E0E0E0" width="100%">
4829 <pre class="SCREEN">
4834 .worldpay.com # for quietpc.com
4842 <p>The <tt class="LITERAL"><a href=
4843 "actions-file.html#FAST-REDIRECTS">fast-redirects</a></tt> action,
4844 which may have been enabled in <tt class=
4845 "FILENAME">match-all.action</tt>, breaks some sites. So disable it
4846 for popular sites where we know it misbehaves:</p>
4848 <table border="0" bgcolor="#E0E0E0" width="100%">
4851 <pre class="SCREEN">
4852 { -<a href="actions-file.html#FAST-REDIRECTS">fast-redirects</a> }
4856 .altavista.com/.*(like|url|link):http
4857 .altavista.com/trans.*urltext=http
4864 <p>It is important that <span class="APPLICATION">Privoxy</span>
4865 knows which URLs belong to images, so that <span class=
4866 "emphasis"><i class="EMPHASIS">if</i></span> they are to be blocked,
4867 a substitute image can be sent, rather than an HTML page. Contacting
4868 the remote site to find out is not an option, since it would destroy
4869 the loading time advantage of banner blocking, and it would feed the
4870 advertisers information about you. We can mark any URL as an image
4871 with the <tt class="LITERAL"><a href=
4872 "actions-file.html#HANDLE-AS-IMAGE">handle-as-image</a></tt> action,
4873 and marking all URLs that end in a known image file extension is a
4876 <table border="0" bgcolor="#E0E0E0" width="100%">
4879 <pre class="SCREEN">
4880 ##########################################################################
4882 ##########################################################################
4884 # Define which file types will be treated as images, in case they get
4885 # blocked further down this file:
4887 { +<a href="actions-file.html#HANDLE-AS-IMAGE">handle-as-image</a> }
4888 /.*\.(gif|jpe?g|png|bmp|ico)$
4894 <p>And then there are known banner sources. They often use scripts to
4895 generate the banners, so it won't be visible from the URL that the
4896 request is for an image. Hence we block them <span class=
4897 "emphasis"><i class="EMPHASIS">and</i></span> mark them as images in
4898 one go, with the help of our <tt class="LITERAL">+block-as-image</tt>
4899 alias defined above. (We could of course just as well use <tt class=
4900 "LITERAL">+<a href="actions-file.html#BLOCK">block</a> +<a href=
4901 "actions-file.html#HANDLE-AS-IMAGE">handle-as-image</a></tt> here.)
4902 Remember that the type of the replacement image is chosen by the
4903 <tt class="LITERAL"><a href=
4904 "actions-file.html#SET-IMAGE-BLOCKER">set-image-blocker</a></tt>
4905 action. Since all URLs have matched the default section with its
4906 <tt class="LITERAL">+<a href=
4907 "actions-file.html#SET-IMAGE-BLOCKER">set-image-blocker</a>{pattern}</tt>
4908 action before, it still applies and needn't be repeated:</p>
4910 <table border="0" bgcolor="#E0E0E0" width="100%">
4913 <pre class="SCREEN">
4914 # Known ad generators:
4919 .ad.*.doubleclick.net
4920 .a.yimg.com/(?:(?!/i/).)*$
4921 .a[0-9].yimg.com/(?:(?!/i/).)*$
4929 <p>One of the most important jobs of <span class=
4930 "APPLICATION">Privoxy</span> is to block banners. Many of these can
4931 be <span class="QUOTE">"blocked"</span> by the <tt class=
4933 "actions-file.html#FILTER">filter</a>{banners-by-size}</tt> action,
4934 which we enabled above, and which deletes the references to banner
4935 images from the pages while they are loaded, so the browser doesn't
4936 request them anymore, and hence they don't need to be blocked here.
4937 But this naturally doesn't catch all banners, and some people choose
4938 not to use filters, so we need a comprehensive list of patterns for
4939 banner URLs here, and apply the <tt class="LITERAL"><a href=
4940 "actions-file.html#BLOCK">block</a></tt> action to them.</p>
4942 <p>First comes many generic patterns, which do most of the work, by
4943 matching typical domain and path name components of banners. Then
4944 comes a list of individual patterns for specific sites, which is
4945 omitted here to keep the example short:</p>
4947 <table border="0" bgcolor="#E0E0E0" width="100%">
4950 <pre class="SCREEN">
4951 ##########################################################################
4952 # Block these fine banners:
4953 ##########################################################################
4954 { <a href="actions-file.html#BLOCK">+block{Banner ads.}</a> }
4962 /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
4963 /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
4965 # Site-specific patterns (abbreviated):
4973 <p>It's quite remarkable how many advertisers actually call their
4974 banner servers ads.<tt class="REPLACEABLE"><i>company</i></tt>.com,
4975 or call the directory in which the banners are stored simply
4976 <span class="QUOTE">"banners"</span>. So the above generic patterns
4977 are surprisingly effective.</p>
4979 <p>But being very generic, they necessarily also catch URLs that we
4980 don't want to block. The pattern <tt class="LITERAL">.*ads.</tt> e.g.
4981 catches <span class="QUOTE">"nasty-<span class="emphasis"><i class=
4982 "EMPHASIS">ads</i></span>.nasty-corp.com"</span> as intended, but
4983 also <span class="QUOTE">"downlo<span class="emphasis"><i class=
4984 "EMPHASIS">ads</i></span>.sourcefroge.net"</span> or <span class=
4985 "QUOTE">"<span class="emphasis"><i class=
4986 "EMPHASIS">ads</i></span>l.some-provider.net."</span> So here come
4987 some well-known exceptions to the <tt class="LITERAL">+<a href=
4988 "actions-file.html#BLOCK">block</a></tt> section above.</p>
4990 <p>Note that these are exceptions to exceptions from the default!
4991 Consider the URL <span class=
4992 "QUOTE">"downloads.sourcefroge.net"</span>: Initially, all actions
4993 are deactivated, so it wouldn't get blocked. Then comes the defaults
4994 section, which matches the URL, but just deactivates the <tt class=
4995 "LITERAL"><a href="actions-file.html#BLOCK">block</a></tt> action
4996 once again. Then it matches <tt class="LITERAL">.*ads.</tt>, an
4997 exception to the general non-blocking policy, and suddenly <tt class=
4998 "LITERAL"><a href="actions-file.html#BLOCK">+block</a></tt> applies.
4999 And now, it'll match <tt class="LITERAL">.*loads.</tt>, where
5000 <tt class="LITERAL"><a href="actions-file.html#BLOCK">-block</a></tt>
5001 applies, so (unless it matches <span class="emphasis"><i class=
5002 "EMPHASIS">again</i></span> further down) it ends up with no
5003 <tt class="LITERAL"><a href="actions-file.html#BLOCK">block</a></tt>
5004 action applying.</p>
5006 <table border="0" bgcolor="#E0E0E0" width="100%">
5009 <pre class="SCREEN">
5010 ##########################################################################
5011 # Save some innocent victims of the above generic block patterns:
5012 ##########################################################################
5016 { -<a href="actions-file.html#BLOCK">block</a> }
5017 adv[io]*. # (for advogato.org and advice.*)
5018 adsl. # (has nothing to do with ads)
5019 adobe. # (has nothing to do with ads either)
5020 ad[ud]*. # (adult.* and add.*)
5021 .edu # (universities don't host banners (yet!))
5022 .*loads. # (downloads, uploads etc)
5030 www.globalintersec.com/adv # (adv = advanced)
5031 www.ugu.com/sui/ugu/adv
5037 <p>Filtering source code can have nasty side effects, so make an
5038 exception for our friends at sourceforge.net, and all paths with
5039 <span class="QUOTE">"cvs"</span> in them. Note that <tt class=
5040 "LITERAL">-<a href="actions-file.html#FILTER">filter</a></tt>
5041 disables <span class="emphasis"><i class="EMPHASIS">all</i></span>
5042 filters in one fell swoop!</p>
5044 <table border="0" bgcolor="#E0E0E0" width="100%">
5047 <pre class="SCREEN">
5048 # Don't filter code!
5050 { -<a href="actions-file.html#FILTER">filter</a> }
5061 <p>The actual <tt class="FILENAME">default.action</tt> is of course
5062 much more comprehensive, but we hope this example made clear how it
5067 <h3 class="SECT3"><a name="USER-ACTION" id="USER-ACTION">8.7.3.
5068 user.action</a></h3>
5070 <p>So far we are painting with a broad brush by setting general
5071 policies, which would be a reasonable starting point for many people.
5072 Now, you might want to be more specific and have customized rules
5073 that are more suitable to your personal habits and preferences. These
5074 would be for narrowly defined situations like your ISP or your bank,
5075 and should be placed in <tt class="FILENAME">user.action</tt>, which
5076 is parsed after all other actions files and hence has the last word,
5077 over-riding any previously defined actions. <tt class=
5078 "FILENAME">user.action</tt> is also a <span class=
5079 "emphasis"><i class="EMPHASIS">safe</i></span> place for your
5080 personal settings, since <tt class="FILENAME">default.action</tt> is
5081 actively maintained by the <span class="APPLICATION">Privoxy</span>
5082 developers and you'll probably want to install updated versions from
5085 <p>So let's look at a few examples of things that one might typically
5086 do in <tt class="FILENAME">user.action</tt>:</p>
5088 <table border="0" bgcolor="#E0E0E0" width="100%">
5091 <pre class="SCREEN">
5092 # My user.action file. <fred@example.com>
5098 <p>As <a href="actions-file.html#ALIASES">aliases</a> are local to
5099 the actions file that they are defined in, you can't use the ones
5100 from <tt class="FILENAME">default.action</tt>, unless you repeat them
5103 <table border="0" bgcolor="#E0E0E0" width="100%">
5106 <pre class="SCREEN">
5107 # Aliases are local to the file they are defined in.
5108 # (Re-)define aliases for this file:
5112 # These aliases just save typing later, and the alias names should
5113 # be self explanatory.
5115 +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
5116 -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
5117 allow-all-cookies = -crunch-all-cookies -session-cookies-only
5118 allow-popups = -filter{all-popups}
5119 +block-as-image = +block{Blocked as image.} +handle-as-image
5120 -block-as-image = -block
5122 # These aliases define combinations of actions that are useful for
5123 # certain types of sites:
5125 fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referrer
5126 shop = -crunch-all-cookies allow-popups
5128 # Allow ads for selected useful free sites:
5130 allow-ads = -block -filter{banners-by-size} -filter{banners-by-link}
5132 # Alias for specific file types that are text, but might have conflicting
5133 # MIME types. We want the browser to force these to be text documents.
5134 handle-as-text = -<a href="actions-file.html#FILTER">filter</a> +-<a href=
5135 "actions-file.html#CONTENT-TYPE-OVERWRITE">content-type-overwrite{text/plain}</a> +-<a href="actions-file.html#FORCE-TEXT-MODE">force-text-mode</a> -<a href="actions-file.html#HIDE-CONTENT-DISPOSITION">hide-content-disposition</a>
5141 <p>Say you have accounts on some sites that you visit regularly, and
5142 you don't want to have to log in manually each time. So you'd like to
5143 allow persistent cookies for these sites. The <tt class=
5144 "LITERAL">allow-all-cookies</tt> alias defined above does exactly
5145 that, i.e. it disables crunching of cookies in any direction, and the
5146 processing of cookies to make them only temporary.</p>
5148 <table border="0" bgcolor="#E0E0E0" width="100%">
5151 <pre class="SCREEN">
5152 { allow-all-cookies }
5162 <p>Your bank is allergic to some filter, but you don't know which, so
5163 you disable them all:</p>
5165 <table border="0" bgcolor="#E0E0E0" width="100%">
5168 <pre class="SCREEN">
5169 { -<a href="actions-file.html#FILTER">filter</a> }
5170 .your-home-banking-site.com
5176 <p>Some file types you may not want to filter for various
5179 <table border="0" bgcolor="#E0E0E0" width="100%">
5182 <pre class="SCREEN">
5183 # Technical documentation is likely to contain strings that might
5184 # erroneously get altered by the JavaScript-oriented filters:
5189 # And this stupid host sends streaming video with a wrong MIME type,
5190 # so that Privoxy thinks it is getting HTML and starts filtering:
5192 stupid-server.example.com/
5198 <p>Example of a simple <a href="actions-file.html#BLOCK">block</a>
5199 action. Say you've seen an ad on your favourite page on example.com
5200 that you want to get rid of. You have right-clicked the image,
5201 selected <span class="QUOTE">"copy image location"</span> and pasted
5202 the URL below while removing the leading http://, into a <tt class=
5203 "LITERAL">{ +block{} }</tt> section. Note that <tt class="LITERAL">{
5204 +handle-as-image }</tt> need not be specified, since all URLs ending
5205 in <tt class="LITERAL">.gif</tt> will be tagged as images by the
5206 general rules as set in default.action anyway:</p>
5208 <table border="0" bgcolor="#E0E0E0" width="100%">
5211 <pre class="SCREEN">
5212 { +<a href="actions-file.html#BLOCK">block</a>{Nasty ads.} }
5213 www.example.com/nasty-ads/sponsor\.gif
5214 another.example.net/more/junk/here/
5220 <p>The URLs of dynamically generated banners, especially from large
5221 banner farms, often don't use the well-known image file name
5222 extensions, which makes it impossible for <span class=
5223 "APPLICATION">Privoxy</span> to guess the file type just by looking
5224 at the URL. You can use the <tt class="LITERAL">+block-as-image</tt>
5225 alias defined above for these cases. Note that objects which match
5226 this rule but then turn out NOT to be an image are typically rendered
5227 as a <span class="QUOTE">"broken image"</span> icon by the browser.
5230 <table border="0" bgcolor="#E0E0E0" width="100%">
5233 <pre class="SCREEN">
5244 <p>Now you noticed that the default configuration breaks Forbes
5245 Magazine, but you were too lazy to find out which action is the
5246 culprit, and you were again too lazy to give <a href=
5247 "contact.html">feedback</a>, so you just used the <tt class=
5248 "LITERAL">fragile</tt> alias on the site, and -- <span class=
5249 "emphasis"><i class="EMPHASIS">whoa!</i></span> -- it worked. The
5250 <tt class="LITERAL">fragile</tt> aliases disables those actions that
5251 are most likely to break a site. Also, good for testing purposes to
5252 see if it is <span class="APPLICATION">Privoxy</span> that is causing
5253 the problem or not. We later find other regular sites that misbehave,
5254 and add those to our personalized list of troublemakers:</p>
5256 <table border="0" bgcolor="#E0E0E0" width="100%">
5259 <pre class="SCREEN">
5269 <p>You like the <span class="QUOTE">"fun"</span> text replacements in
5270 <tt class="FILENAME">default.filter</tt>, but it is disabled in the
5271 distributed actions file. So you'd like to turn it on in your
5272 private, update-safe config, once and for all:</p>
5274 <table border="0" bgcolor="#E0E0E0" width="100%">
5277 <pre class="SCREEN">
5278 { +<a href="actions-file.html#FILTER-FUN">filter{fun}</a> }
5285 <p>Note that the above is not really a good idea: There are
5286 exceptions to the filters in <tt class="FILENAME">default.action</tt>
5287 for things that really shouldn't be filtered, like code on
5288 CVS->Web interfaces. Since <tt class="FILENAME">user.action</tt>
5289 has the last word, these exceptions won't be valid for the
5290 <span class="QUOTE">"fun"</span> filtering specified here.</p>
5292 <p>You might also worry about how your favourite free websites are
5293 funded, and find that they rely on displaying banner advertisements
5294 to survive. So you might want to specifically allow banners for those
5295 sites that you feel provide value to you:</p>
5297 <table border="0" bgcolor="#E0E0E0" width="100%">
5300 <pre class="SCREEN">
5310 <p>Note that <tt class="LITERAL">allow-ads</tt> has been aliased to
5311 <tt class="LITERAL">-<a href=
5312 "actions-file.html#BLOCK">block</a></tt>, <tt class=
5314 "actions-file.html#FILTER-BANNERS-BY-SIZE">filter{banners-by-size}</a></tt>,
5315 and <tt class="LITERAL">-<a href=
5316 "actions-file.html#FILTER-BANNERS-BY-LINK">filter{banners-by-link}</a></tt>
5319 <p>Invoke another alias here to force an over-ride of the MIME type
5320 <tt class="LITERAL">application/x-sh</tt> which typically would open
5321 a download type dialog. In my case, I want to look at the shell
5322 script, and then I can save it should I choose to.</p>
5324 <table border="0" bgcolor="#E0E0E0" width="100%">
5327 <pre class="SCREEN">
5335 <p><tt class="FILENAME">user.action</tt> is generally the best place
5336 to define exceptions and additions to the default policies of
5337 <tt class="FILENAME">default.action</tt>. Some actions are safe to
5338 have their default policies set here though. So let's set a default
5339 policy to have a <span class="QUOTE">"blank"</span> image as opposed
5340 to the checkerboard pattern for <span class="emphasis"><i class=
5341 "EMPHASIS">ALL</i></span> sites. <span class="QUOTE">"/"</span> of
5342 course matches all URL paths and patterns:</p>
5344 <table border="0" bgcolor="#E0E0E0" width="100%">
5347 <pre class="SCREEN">
5349 "actions-file.html#SET-IMAGE-BLOCKER">set-image-blocker{blank}</a> }
5359 <div class="NAVFOOTER">
5360 <hr align="left" width="100%">
5362 <table summary="Footer navigation table" width="100%" border="0"
5363 cellpadding="0" cellspacing="0">
5365 <td width="33%" align="left" valign="top"><a href="config.html"
5366 accesskey="P">Prev</a></td>
5368 <td width="34%" align="center" valign="top"><a href="index.html"
5369 accesskey="H">Home</a></td>
5371 <td width="33%" align="right" valign="top"><a href="filter-file.html"
5372 accesskey="N">Next</a></td>
5376 <td width="33%" align="left" valign="top">The Main Configuration
5379 <td width="34%" align="center" valign="top"> </td>
5381 <td width="33%" align="right" valign="top">Filter Files</td>
projects / privoxy.git / blob