-<HTML
-><HEAD
-><TITLE
->Actions Files</TITLE
-><META
-NAME="GENERATOR"
-CONTENT="Modular DocBook HTML Stylesheet Version 1.60"><LINK
-REL="HOME"
-TITLE="Privoxy User Manual"
-HREF="index.html"><LINK
-REL="PREVIOUS"
-TITLE="The Main Configuration File"
-HREF="config.html"><LINK
-REL="NEXT"
-TITLE="The Filter File"
-HREF="filter-file.html"><LINK
-REL="STYLESHEET"
-TYPE="text/css"
-HREF="../p_doc.css"></HEAD
-><BODY
-CLASS="SECT1"
-BGCOLOR="#EEEEEE"
-TEXT="#000000"
-LINK="#0000FF"
-VLINK="#840084"
-ALINK="#0000FF"
-><DIV
-CLASS="NAVHEADER"
-><TABLE
-WIDTH="100%"
-BORDER="0"
-CELLPADDING="0"
-CELLSPACING="0"
-><TR
-><TH
-COLSPAN="3"
-ALIGN="center"
->Privoxy User Manual</TH
-></TR
-><TR
-><TD
-WIDTH="10%"
-ALIGN="left"
-VALIGN="bottom"
-><A
-HREF="config.html"
->Prev</A
-></TD
-><TD
-WIDTH="80%"
-ALIGN="center"
-VALIGN="bottom"
-></TD
-><TD
-WIDTH="10%"
-ALIGN="right"
-VALIGN="bottom"
-><A
-HREF="filter-file.html"
->Next</A
-></TD
-></TR
-></TABLE
-><HR
-ALIGN="LEFT"
-WIDTH="100%"></DIV
-><DIV
-CLASS="SECT1"
-><H1
-CLASS="SECT1"
-><A
-NAME="ACTIONS-FILE"
->8. Actions Files</A
-></H1
-><P
-> The actions files are used to define what actions
- <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> takes for which URLs, and thus determine
- how ad images, cookies and various other aspects of HTTP content and
- transactions are handled, and on which sites (or even parts thereof). There
- are three such files included with <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> (as of
- version 2.9.15), with differing purposes:
- </P
-><P
-> <P
-></P
-><UL
-><LI
-><P
-> <TT
-CLASS="FILENAME"
->default.action</TT
-> - is the primary action file
- that sets the initial values for all actions. It is intended to
- provide a base level of functionality for
- <SPAN
-CLASS="APPLICATION"
->Privoxy's</SPAN
-> array of features. So it is
- a set of broad rules that should work reasonably well for users everywhere.
- This is the file that the developers are keeping updated, and making
- available to users.
- </P
-></LI
-><LI
-><P
-> <TT
-CLASS="FILENAME"
->user.action</TT
-> - is intended to be for local site
- preferences and exceptions. As an example, if your ISP or your bank
- has specific requirements, and need special handling, this kind of
- thing should go here. This file will not be upgraded.
- </P
-></LI
-><LI
-><P
-> <TT
-CLASS="FILENAME"
->standard.action</TT
-> - is used by the web based editor,
- to set various pre-defined sets of rules for the default actions section
- in <TT
-CLASS="FILENAME"
->default.action</TT
->. These have increasing levels of
- aggressiveness <I
-CLASS="EMPHASIS"
->and have no influence on your browsing unless
- you select them explicitly in the editor</I
->. It is not recommend
- to edit this file.
- </P
-></LI
-></UL
->
- </P
-><P
-> The list of actions files to be used are defined in the main configuration
- file, and are processed in the order they are defined. The content of these
- can all be viewed and edited from <A
-HREF="http://config.privoxy.org/show-status"
-TARGET="_top"
->http://config.privoxy.org/show-status</A
->.</P
-><P
-> An actions file typically has multiple sections. If you want to use
- <SPAN
-CLASS="QUOTE"
->"aliases"</SPAN
-> in an actions file, you have to place the (optional)
- <A
-HREF="actions-file.html#ALIASES"
->alias section</A
-> at the top of that file.
- Then comes the default set of rules which will apply universally to all
- sites and pages (be <I
-CLASS="EMPHASIS"
->very careful</I
-> with using such a
- universal set in <TT
-CLASS="FILENAME"
->user.action</TT
-> or any other actions file after
- <TT
-CLASS="FILENAME"
->default.action</TT
->, because it will override the result
- from consulting any previous file). And then below that,
- exceptions to the defined universal policies. You can regard
- <TT
-CLASS="FILENAME"
->user.action</TT
-> as an appendix to <TT
-CLASS="FILENAME"
->default.action</TT
->,
- with the advantage that is a separate file, which makes preserving your
- personal settings across <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> upgrades easier.</P
-><P
->
- Actions can be used to block anything you want, including ads, banners, or
- just some obnoxious URL that you would rather not see. Cookies can be accepted
- or rejected, or accepted only during the current browser session (i.e. not
- written to disk), content can be modified, JavaScripts tamed, user-tracking
- fooled, and much more. See below for a <A
-HREF="actions-file.html#ACTIONS"
->complete list
- of actions</A
->.</P
-><DIV
-CLASS="SECT2"
-><H2
-CLASS="SECT2"
-><A
-NAME="AEN1403"
->8.1. Finding the Right Mix</A
-></H2
-><P
-> Note that some <A
-HREF="actions-file.html#ACTIONS"
->actions</A
->, like cookie suppression
- or script disabling, may render some sites unusable that rely on these
- techniques to work properly. Finding the right mix of actions is not always easy and
- certainly a matter of personal taste. In general, it can be said that the more
- <SPAN
-CLASS="QUOTE"
->"aggressive"</SPAN
-> your default settings (in the top section of the
- actions file) are, the more exceptions for <SPAN
-CLASS="QUOTE"
->"trusted"</SPAN
-> sites you
- will have to make later. If, for example, you want to kill popup windows per
- default, you'll have to make exceptions from that rule for sites that you
- regularly use and that require popups for actually useful content, like maybe
- your bank, favorite shop, or newspaper.</P
-><P
-> We have tried to provide you with reasonable rules to start from in the
- distribution actions files. But there is no general rule of thumb on these
- things. There just are too many variables, and sites are constantly changing.
- Sooner or later you will want to change the rules (and read this chapter again :).</P
-></DIV
-><DIV
-CLASS="SECT2"
-><H2
-CLASS="SECT2"
-><A
-NAME="AEN1410"
->8.2. How to Edit</A
-></H2
-><P
-> The easiest way to edit the actions files is with a browser by
- using our browser-based editor, which can be reached from <A
-HREF="http://config.privoxy.org/show-status"
-TARGET="_top"
->http://config.privoxy.org/show-status</A
->.
- The editor allows both fine-grained control over every single feature on a
- per-URL basis, and easy choosing from wholesale sets of defaults like
- <SPAN
-CLASS="QUOTE"
->"Cautious"</SPAN
->, <SPAN
-CLASS="QUOTE"
->"Medium"</SPAN
-> or <SPAN
-CLASS="QUOTE"
->"Advanced"</SPAN
->.</P
-><P
-> If you prefer plain text editing to GUIs, you can of course also directly edit the
- the actions files. Look at <TT
-CLASS="FILENAME"
->default.action</TT
-> which is richly
- commented.</P
-></DIV
-><DIV
-CLASS="SECT2"
-><H2
-CLASS="SECT2"
-><A
-NAME="ACTIONS-APPLY"
->8.3. How Actions are Applied to URLs</A
-></H2
-><P
-> Actions files are divided into sections. There are special sections,
- like the <SPAN
-CLASS="QUOTE"
->"<A
-HREF="actions-file.html#ALIASES"
->alias</A
->"</SPAN
-> sections which will be discussed later. For now
- let's concentrate on regular sections: They have a heading line (often split
- up to multiple lines for readability) which consist of a list of actions,
- separated by whitespace and enclosed in curly braces. Below that, there
- is a list of URL patterns, each on a separate line.</P
-><P
-> To determine which actions apply to a request, the URL of the request is
- compared to all patterns in each action file file. Every time it matches, the list of
- applicable actions for the URL is incrementally updated, using the heading
- of the section in which the pattern is located. If multiple matches for
- the same URL set the same action differently, the last match wins. If not,
- the effects are aggregated (e.g. a URL might match both the
- <A
-HREF="actions-file.html#HANDLE-AS-IMAGE"
-TARGET="_top"
-><SPAN
-CLASS="QUOTE"
->"+handle-as-image"</SPAN
-></A
->
- and <A
-HREF="actions-file.html#BLOCK"
-TARGET="_top"
-><SPAN
-CLASS="QUOTE"
->"+block"</SPAN
-></A
-> actions).
- </P
-><P
-> You can trace this process for any given URL by visiting <A
-HREF="http://config.privoxy.org/show-url-info"
-TARGET="_top"
->http://config.privoxy.org/show-url-info</A
->.</P
-><P
-> More detail on this is provided in the Appendix, <A
-HREF="appendix.html#ACTIONSANAT"
-> Anatomy of an Action</A
->.</P
-></DIV
-><DIV
-CLASS="SECT2"
-><H2
-CLASS="SECT2"
-><A
-NAME="AF-PATTERNS"
->8.4. Patterns</A
-></H2
-><P
-> Generally, a pattern has the form <TT
-CLASS="LITERAL"
-><domain>/<path></TT
->,
- where both the <TT
-CLASS="LITERAL"
-><domain></TT
-> and <TT
-CLASS="LITERAL"
-><path></TT
->
- are optional. (This is why the pattern <TT
-CLASS="LITERAL"
->/</TT
-> matches all URLs).</P
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
-><TT
-CLASS="LITERAL"
->www.example.com/</TT
-></DT
-><DD
-><P
-> is a domain-only pattern and will match any request to <TT
-CLASS="LITERAL"
->www.example.com</TT
->,
- regardless of which document on that server is requested.
- </P
-></DD
-><DT
-><TT
-CLASS="LITERAL"
->www.example.com</TT
-></DT
-><DD
-><P
-> means exactly the same. For domain-only patterns, the trailing <TT
-CLASS="LITERAL"
->/</TT
-> may
- be omitted.
- </P
-></DD
-><DT
-><TT
-CLASS="LITERAL"
->www.example.com/index.html</TT
-></DT
-><DD
-><P
-> matches only the single document <TT
-CLASS="LITERAL"
->/index.html</TT
->
- on <TT
-CLASS="LITERAL"
->www.example.com</TT
->.
- </P
-></DD
-><DT
-><TT
-CLASS="LITERAL"
->/index.html</TT
-></DT
-><DD
-><P
-> matches the document <TT
-CLASS="LITERAL"
->/index.html</TT
->, regardless of the domain,
- i.e. on <I
-CLASS="EMPHASIS"
->any</I
-> web server.
- </P
-></DD
-><DT
-><TT
-CLASS="LITERAL"
->index.html</TT
-></DT
-><DD
-><P
-> matches nothing, since it would be interpreted as a domain name and
- there is no top-level domain called <TT
-CLASS="LITERAL"
->.html</TT
->.
- </P
-></DD
-></DL
-></DIV
-><DIV
-CLASS="SECT3"
-><H3
-CLASS="SECT3"
-><A
-NAME="AEN1473"
->8.4.1. The Domain Pattern</A
-></H3
-><P
-> The matching of the domain part offers some flexible options: if the
- domain starts or ends with a dot, it becomes unanchored at that end.
- For example:</P
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
-><TT
-CLASS="LITERAL"
->.example.com</TT
-></DT
-><DD
-><P
-> matches any domain that <I
-CLASS="EMPHASIS"
->ENDS</I
-> in
- <TT
-CLASS="LITERAL"
->.example.com</TT
->
- </P
-></DD
-><DT
-><TT
-CLASS="LITERAL"
->www.</TT
-></DT
-><DD
-><P
-> matches any domain that <I
-CLASS="EMPHASIS"
->STARTS</I
-> with
- <TT
-CLASS="LITERAL"
->www.</TT
->
- </P
-></DD
-><DT
-><TT
-CLASS="LITERAL"
->.example.</TT
-></DT
-><DD
-><P
-> matches any domain that <I
-CLASS="EMPHASIS"
->CONTAINS</I
-> <TT
-CLASS="LITERAL"
->.example.</TT
->
- (Correctly speaking: It matches any FQDN that contains <TT
-CLASS="LITERAL"
->example</TT
-> as a domain.)
- </P
-></DD
-></DL
-></DIV
-><P
-> Additionally, there are wild-cards that you can use in the domain names
- themselves. They work pretty similar to shell wild-cards: <SPAN
-CLASS="QUOTE"
->"*"</SPAN
->
- stands for zero or more arbitrary characters, <SPAN
-CLASS="QUOTE"
->"?"</SPAN
-> stands for
- any single character, you can define character classes in square
- brackets and all of that can be freely mixed:</P
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
-><TT
-CLASS="LITERAL"
->ad*.example.com</TT
-></DT
-><DD
-><P
-> matches <SPAN
-CLASS="QUOTE"
->"adserver.example.com"</SPAN
->,
- <SPAN
-CLASS="QUOTE"
->"ads.example.com"</SPAN
->, etc but not <SPAN
-CLASS="QUOTE"
->"sfads.example.com"</SPAN
->
- </P
-></DD
-><DT
-><TT
-CLASS="LITERAL"
->*ad*.example.com</TT
-></DT
-><DD
-><P
-> matches all of the above, and then some.
- </P
-></DD
-><DT
-><TT
-CLASS="LITERAL"
->.?pix.com</TT
-></DT
-><DD
-><P
-> matches <TT
-CLASS="LITERAL"
->www.ipix.com</TT
->,
- <TT
-CLASS="LITERAL"
->pictures.epix.com</TT
->, <TT
-CLASS="LITERAL"
->a.b.c.d.e.upix.com</TT
-> etc.
- </P
-></DD
-><DT
-><TT
-CLASS="LITERAL"
->www[1-9a-ez].example.c*</TT
-></DT
-><DD
-><P
-> matches <TT
-CLASS="LITERAL"
->www1.example.com</TT
->,
- <TT
-CLASS="LITERAL"
->www4.example.cc</TT
->, <TT
-CLASS="LITERAL"
->wwwd.example.cy</TT
->,
- <TT
-CLASS="LITERAL"
->wwwz.example.com</TT
-> etc., but <I
-CLASS="EMPHASIS"
->not</I
->
- <TT
-CLASS="LITERAL"
->wwww.example.com</TT
->.
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H3
-CLASS="SECT3"
-><A
-NAME="AEN1535"
->8.4.2. The Path Pattern</A
-></H3
-><P
-> <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> uses Perl compatible regular expressions
- (through the <A
-HREF="http://www.pcre.org/"
-TARGET="_top"
->PCRE</A
-> library) for
- matching the path.</P
-><P
-> There is an <A
-HREF="appendix.html#REGEX"
->Appendix</A
-> with a brief quick-start into regular
- expressions, and full (very technical) documentation on PCRE regex syntax is available on-line
- at <A
-HREF="http://www.pcre.org/man.txt"
-TARGET="_top"
->http://www.pcre.org/man.txt</A
->.
- You might also find the Perl man page on regular expressions (<TT
-CLASS="LITERAL"
->man perlre</TT
->)
- useful, which is available on-line at <A
-HREF="http://www.perldoc.com/perl5.6/pod/perlre.html"
-TARGET="_top"
->http://www.perldoc.com/perl5.6/pod/perlre.html</A
->.</P
-><P
-> Note that the path pattern is automatically left-anchored at the <SPAN
-CLASS="QUOTE"
->"/"</SPAN
->,
- i.e. it matches as if it would start with a <SPAN
-CLASS="QUOTE"
->"^"</SPAN
-> (regular expression speak
- for the beginning of a line).</P
-><P
-> Please also note that matching in the path is case
- <I
-CLASS="EMPHASIS"
->INSENSITIVE</I
-> by default, but you can switch to case
- sensitive at any point in the pattern by using the
- <SPAN
-CLASS="QUOTE"
->"(?-i)"</SPAN
-> switch:
- <TT
-CLASS="LITERAL"
->www.example.com/(?-i)PaTtErN.*</TT
-> will match only
- documents whose path starts with <TT
-CLASS="LITERAL"
->PaTtErN</TT
-> in
- <I
-CLASS="EMPHASIS"
->exactly</I
-> this capitalization.</P
-></DIV
-></DIV
-><DIV
-CLASS="SECT2"
-><H2
-CLASS="SECT2"
-><A
-NAME="ACTIONS"
->8.5. Actions</A
-></H2
-><P
-> All actions are disabled by default, until they are explicitly enabled
- somewhere in an actions file. Actions are turned on if preceded with a
- <SPAN
-CLASS="QUOTE"
->"+"</SPAN
->, and turned off if preceded with a <SPAN
-CLASS="QUOTE"
->"-"</SPAN
->. So a
- <TT
-CLASS="LITERAL"
->+action</TT
-> means <SPAN
-CLASS="QUOTE"
->"do that action"</SPAN
->, e.g.
- <TT
-CLASS="LITERAL"
->+block</TT
-> means <SPAN
-CLASS="QUOTE"
->"please block URLs that match the
- following patterns"</SPAN
->, and <TT
-CLASS="LITERAL"
->-block</TT
-> means <SPAN
-CLASS="QUOTE"
->"don't
- block URLs that match the following patterns, even if <TT
-CLASS="LITERAL"
->+block</TT
->
- previously applied."</SPAN
-> </P
-><P
->
- Again, actions are invoked by placing them on a line, enclosed in curly braces and
- separated by whitespace, like in
- <TT
-CLASS="LITERAL"
->{+some-action -some-other-action{some-parameter}}</TT
->,
- followed by a list of URL patterns, one per line, to which they apply.
- Together, the actions line and the following pattern lines make up a section
- of the actions file. </P
-><P
->
- There are three classes of actions:</P
-><P
-> <P
-></P
-><UL
-><LI
-><P
->
- Boolean, i.e the action can only be <SPAN
-CLASS="QUOTE"
->"enabled"</SPAN
-> or
- <SPAN
-CLASS="QUOTE"
->"disabled"</SPAN
->. Syntax:
- </P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
-> +<TT
-CLASS="REPLACEABLE"
-><I
->name</I
-></TT
-> # enable action <TT
-CLASS="REPLACEABLE"
-><I
->name</I
-></TT
->
- -<TT
-CLASS="REPLACEABLE"
-><I
->name</I
-></TT
-> # disable action <TT
-CLASS="REPLACEABLE"
-><I
->name</I
-></TT
-></PRE
-></TD
-></TR
-></TABLE
->
- </P
-><P
->
- Example: <TT
-CLASS="LITERAL"
->+block</TT
->
- </P
-></LI
-><LI
-><P
->
- Parameterized, where some value is required in order to enable this type of action.
- Syntax:
- </P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
-> +<TT
-CLASS="REPLACEABLE"
-><I
->name</I
-></TT
->{<TT
-CLASS="REPLACEABLE"
-><I
->param</I
-></TT
->} # enable action and set parameter to <TT
-CLASS="REPLACEABLE"
-><I
->param</I
-></TT
->,
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
+"http://www.w3.org/TR/html4/loose.dtd">
+
+<html>
+<head>
+ <title>Actions Files</title>
+ <meta name="GENERATOR" content=
+ "Modular DocBook HTML Stylesheet Version 1.79">
+ <link rel="HOME" title="Privoxy 3.0.21 User Manual" href="index.html">
+ <link rel="PREVIOUS" title="The Main Configuration File" href=
+ "config.html">
+ <link rel="NEXT" title="Filter Files" href="filter-file.html">
+ <link rel="STYLESHEET" type="text/css" href="../p_doc.css">
+ <meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
+ <link rel="STYLESHEET" type="text/css" href="p_doc.css">
+</head>
+
+<body class="SECT1" bgcolor="#EEEEEE" text="#000000" link="#0000FF" vlink=
+"#840084" alink="#0000FF">
+ <div class="NAVHEADER">
+ <table summary="Header navigation table" width="100%" border="0"
+ cellpadding="0" cellspacing="0">
+ <tr>
+ <th colspan="3" align="center">Privoxy 3.0.21 User Manual</th>
+ </tr>
+
+ <tr>
+ <td width="10%" align="left" valign="bottom"><a href="config.html"
+ accesskey="P">Prev</a></td>
+
+ <td width="80%" align="center" valign="bottom"></td>
+
+ <td width="10%" align="right" valign="bottom"><a href=
+ "filter-file.html" accesskey="N">Next</a></td>
+ </tr>
+ </table>
+ <hr align="left" width="100%">
+ </div>
+
+ <div class="SECT1">
+ <h1 class="SECT1"><a name="ACTIONS-FILE" id="ACTIONS-FILE">8. Actions
+ Files</a></h1>
+
+ <p>The actions files are used to define what <span class=
+ "emphasis"><i class="EMPHASIS">actions</i></span> <span class=
+ "APPLICATION">Privoxy</span> takes for which URLs, and thus determines
+ how ad images, cookies and various other aspects of HTTP content and
+ transactions are handled, and on which sites (or even parts thereof).
+ There are a number of such actions, with a wide range of functionality.
+ Each action does something a little different. These actions give us a
+ veritable arsenal of tools with which to exert our control, preferences
+ and independence. Actions can be combined so that their effects are
+ aggregated when applied against a given set of URLs.</p>
+
+ <p>There are three action files included with <span class=
+ "APPLICATION">Privoxy</span> with differing purposes:</p>
+
+ <ul>
+ <li>
+ <p><tt class="FILENAME">match-all.action</tt> - is used to define
+ which <span class="QUOTE">"actions"</span> relating to
+ banner-blocking, images, pop-ups, content modification, cookie
+ handling etc should be applied by default. It should be the first
+ actions file loaded</p>
+ </li>
+
+ <li>
+ <p><tt class="FILENAME">default.action</tt> - defines many exceptions
+ (both positive and negative) from the default set of actions that's
+ configured in <tt class="FILENAME">match-all.action</tt>. It is a set
+ of rules that should work reasonably well as-is for most users. This
+ file is only supposed to be edited by the developers. It should be
+ the second actions file loaded.</p>
+ </li>
+
+ <li>
+ <p><tt class="FILENAME">user.action</tt> - is intended to be for
+ local site preferences and exceptions. As an example, if your ISP or
+ your bank has specific requirements, and need special handling, this
+ kind of thing should go here. This file will not be upgraded.</p>
+ </li>
+
+ <li>
+ <p><span class="GUIBUTTON">Edit</span> <span class="GUIBUTTON">Set to
+ Cautious</span> <span class="GUIBUTTON">Set to Medium</span>
+ <span class="GUIBUTTON">Set to Advanced</span></p>
+
+ <p>These have increasing levels of aggressiveness <span class=
+ "emphasis"><i class="EMPHASIS">and have no influence on your browsing
+ unless you select them explicitly in the editor</i></span>. A default
+ installation should be pre-set to <tt class="LITERAL">Cautious</tt>.
+ New users should try this for a while before adjusting the settings
+ to more aggressive levels. The more aggressive the settings, then the
+ more likelihood there is of problems such as sites not working as
+ they should.</p>
+
+ <p>The <span class="GUIBUTTON">Edit</span> button allows you to turn
+ each action on/off individually for fine-tuning. The <span class=
+ "GUIBUTTON">Cautious</span> button changes the actions list to
+ low/safe settings which will activate ad blocking and a minimal set
+ of <span class="APPLICATION">Privoxy</span>'s features, and
+ subsequently there will be less of a chance for accidental problems.
+ The <span class="GUIBUTTON">Medium</span> button sets the list to a
+ medium level of other features and a low level set of privacy
+ features. The <span class="GUIBUTTON">Advanced</span> button sets the
+ list to a high level of ad blocking and medium level of privacy. See
+ the chart below. The latter three buttons over-ride any changes via
+ with the <span class="GUIBUTTON">Edit</span> button. More fine-tuning
+ can be done in the lower sections of this internal page.</p>
+
+ <p>While the actions file editor allows to enable these settings in
+ all actions files, they are only supposed to be enabled in the first
+ one to make sure you don't unintentionally overrule earlier
+ rules.</p>
+
+ <p>The default profiles, and their associated actions, as pre-defined
+ in <tt class="FILENAME">default.action</tt> are:</p>
+
+ <div class="TABLE">
+ <a name="AEN2777" id="AEN2777"></a>
+
+ <p><b>Table 1. Default Configurations</b></p>
+
+ <table border="1" frame="border" rules="all" class="CALSTABLE">
+ <col width="1*" title="C1">
+ <col width="1*" title="C2">
+ <col width="1*" title="C3">
+ <col width="1*" title="C4">
+
+ <thead>
+ <tr>
+ <th>Feature</th>
+
+ <th>Cautious</th>
+
+ <th>Medium</th>
+
+ <th>Advanced</th>
+ </tr>
+ </thead>
+
+ <tbody>
+ <tr>
+ <td>Ad-blocking Aggressiveness</td>
+
+ <td>medium</td>
+
+ <td>high</td>
+
+ <td>high</td>
+ </tr>
+
+ <tr>
+ <td>Ad-filtering by size</td>
+
+ <td>no</td>
+
+ <td>yes</td>
+
+ <td>yes</td>
+ </tr>
+
+ <tr>
+ <td>Ad-filtering by link</td>
+
+ <td>no</td>
+
+ <td>no</td>
+
+ <td>yes</td>
+ </tr>
+
+ <tr>
+ <td>Pop-up killing</td>
+
+ <td>blocks only</td>
+
+ <td>blocks only</td>
+
+ <td>blocks only</td>
+ </tr>
+
+ <tr>
+ <td>Privacy Features</td>
+
+ <td>low</td>
+
+ <td>medium</td>
+
+ <td>medium/high</td>
+ </tr>
+
+ <tr>
+ <td>Cookie handling</td>
+
+ <td>none</td>
+
+ <td>session-only</td>
+
+ <td>kill</td>
+ </tr>
+
+ <tr>
+ <td>Referer forging</td>
+
+ <td>no</td>
+
+ <td>yes</td>
+
+ <td>yes</td>
+ </tr>
+
+ <tr>
+ <td>GIF de-animation</td>
+
+ <td>no</td>
+
+ <td>yes</td>
+
+ <td>yes</td>
+ </tr>
+
+ <tr>
+ <td>Fast redirects</td>
+
+ <td>no</td>
+
+ <td>no</td>
+
+ <td>yes</td>
+ </tr>
+
+ <tr>
+ <td>HTML taming</td>
+
+ <td>no</td>
+
+ <td>no</td>
+
+ <td>yes</td>
+ </tr>
+
+ <tr>
+ <td>JavaScript taming</td>
+
+ <td>no</td>
+
+ <td>no</td>
+
+ <td>yes</td>
+ </tr>
+
+ <tr>
+ <td>Web-bug killing</td>
+
+ <td>no</td>
+
+ <td>yes</td>
+
+ <td>yes</td>
+ </tr>
+
+ <tr>
+ <td>Image tag reordering</td>
+
+ <td>no</td>
+
+ <td>yes</td>
+
+ <td>yes</td>
+ </tr>
+ </tbody>
+ </table>
+ </div>
+ </li>
+ </ul>
+
+ <p>The list of actions files to be used are defined in the main
+ configuration file, and are processed in the order they are defined (e.g.
+ <tt class="FILENAME">default.action</tt> is typically processed before
+ <tt class="FILENAME">user.action</tt>). The content of these can all be
+ viewed and edited from <a href="http://config.privoxy.org/show-status"
+ target="_top">http://config.privoxy.org/show-status</a>. The over-riding
+ principle when applying actions, is that the last action that matches a
+ given URL wins. The broadest, most general rules go first (defined in
+ <tt class="FILENAME">default.action</tt>), followed by any exceptions
+ (typically also in <tt class="FILENAME">default.action</tt>), which are
+ then followed lastly by any local preferences (typically in <span class=
+ "emphasis"><i class="EMPHASIS">user</i></span><tt class=
+ "FILENAME">.action</tt>). Generally, <tt class=
+ "FILENAME">user.action</tt> has the last word.</p>
+
+ <p>An actions file typically has multiple sections. If you want to use
+ <span class="QUOTE">"aliases"</span> in an actions file, you have to
+ place the (optional) <a href="actions-file.html#ALIASES">alias
+ section</a> at the top of that file. Then comes the default set of rules
+ which will apply universally to all sites and pages (be <span class=
+ "emphasis"><i class="EMPHASIS">very careful</i></span> with using such a
+ universal set in <tt class="FILENAME">user.action</tt> or any other
+ actions file after <tt class="FILENAME">default.action</tt>, because it
+ will override the result from consulting any previous file). And then
+ below that, exceptions to the defined universal policies. You can regard
+ <tt class="FILENAME">user.action</tt> as an appendix to <tt class=
+ "FILENAME">default.action</tt>, with the advantage that it is a separate
+ file, which makes preserving your personal settings across <span class=
+ "APPLICATION">Privoxy</span> upgrades easier.</p>
+
+ <p>Actions can be used to block anything you want, including ads,
+ banners, or just some obnoxious URL whose content you would rather not
+ see. Cookies can be accepted or rejected, or accepted only during the
+ current browser session (i.e. not written to disk), content can be
+ modified, some JavaScripts tamed, user-tracking fooled, and much more.
+ See below for a <a href="actions-file.html#ACTIONS">complete list of
+ actions</a>.</p>
+
+ <div class="SECT2">
+ <h2 class="SECT2"><a name="AEN2876" id="AEN2876">8.1. Finding the Right
+ Mix</a></h2>
+
+ <p>Note that some <a href="actions-file.html#ACTIONS">actions</a>, like
+ cookie suppression or script disabling, may render some sites unusable
+ that rely on these techniques to work properly. Finding the right mix
+ of actions is not always easy and certainly a matter of personal taste.
+ And, things can always change, requiring refinements in the
+ configuration. In general, it can be said that the more <span class=
+ "QUOTE">"aggressive"</span> your default settings (in the top section
+ of the actions file) are, the more exceptions for <span class=
+ "QUOTE">"trusted"</span> sites you will have to make later. If, for
+ example, you want to crunch all cookies per default, you'll have to
+ make exceptions from that rule for sites that you regularly use and
+ that require cookies for actually useful purposes, like maybe your
+ bank, favorite shop, or newspaper.</p>
+
+ <p>We have tried to provide you with reasonable rules to start from in
+ the distribution actions files. But there is no general rule of thumb
+ on these things. There just are too many variables, and sites are
+ constantly changing. Sooner or later you will want to change the rules
+ (and read this chapter again :).</p>
+ </div>
+
+ <div class="SECT2">
+ <h2 class="SECT2"><a name="AEN2883" id="AEN2883">8.2. How to
+ Edit</a></h2>
+
+ <p>The easiest way to edit the actions files is with a browser by using
+ our browser-based editor, which can be reached from <a href=
+ "http://config.privoxy.org/show-status" target=
+ "_top">http://config.privoxy.org/show-status</a>. Note: the config file
+ option <a href=
+ "config.html#ENABLE-EDIT-ACTIONS">enable-edit-actions</a> must be
+ enabled for this to work. The editor allows both fine-grained control
+ over every single feature on a per-URL basis, and easy choosing from
+ wholesale sets of defaults like <span class="QUOTE">"Cautious"</span>,
+ <span class="QUOTE">"Medium"</span> or <span class=
+ "QUOTE">"Advanced"</span>. Warning: the <span class=
+ "QUOTE">"Advanced"</span> setting is more aggressive, and will be more
+ likely to cause problems for some sites. Experienced users only!</p>
+
+ <p>If you prefer plain text editing to GUIs, you can of course also
+ directly edit the the actions files with your favorite text editor.
+ Look at <tt class="FILENAME">default.action</tt> which is richly
+ commented with many good examples.</p>
+ </div>
+
+ <div class="SECT2">
+ <h2 class="SECT2"><a name="ACTIONS-APPLY" id="ACTIONS-APPLY">8.3. How
+ Actions are Applied to Requests</a></h2>
+
+ <p>Actions files are divided into sections. There are special sections,
+ like the <span class="QUOTE">"<a href=
+ "actions-file.html#ALIASES">alias</a>"</span> sections which will be
+ discussed later. For now let's concentrate on regular sections: They
+ have a heading line (often split up to multiple lines for readability)
+ which consist of a list of actions, separated by whitespace and
+ enclosed in curly braces. Below that, there is a list of URL and tag
+ patterns, each on a separate line.</p>
+
+ <p>To determine which actions apply to a request, the URL of the
+ request is compared to all URL patterns in each <span class=
+ "QUOTE">"action file"</span>. Every time it matches, the list of
+ applicable actions for the request is incrementally updated, using the
+ heading of the section in which the pattern is located. The same is
+ done again for tags and tag patterns later on.</p>
+
+ <p>If multiple applying sections set the same action differently, the
+ last match wins. If not, the effects are aggregated. E.g. a URL might
+ match a regular section with a heading line of <tt class="LITERAL">{
+ +<a href="actions-file.html#HANDLE-AS-IMAGE">handle-as-image</a>
+ }</tt>, then later another one with just <tt class="LITERAL">{
+ +<a href="actions-file.html#BLOCK">block</a> }</tt>, resulting in
+ <span class="emphasis"><i class="EMPHASIS">both</i></span> actions to
+ apply. And there may well be cases where you will want to combine
+ actions together. Such a section then might look like:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+ { +<tt class="LITERAL">handle-as-image</tt> +<tt class=
+"LITERAL">block{Banner ads.}</tt> }
+ # Block these as if they were images. Send no block page.
+ banners.example.com
+ media.example.com/.*banners
+ .example.com/images/ads/
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>You can trace this process for URL patterns and any given URL by
+ visiting <a href="http://config.privoxy.org/show-url-info" target=
+ "_top">http://config.privoxy.org/show-url-info</a>.</p>
+
+ <p>Examples and more detail on this is provided in the Appendix,
+ <a href="appendix.html#ACTIONSANAT">Troubleshooting: Anatomy of an
+ Action</a> section.</p>
+ </div>
+
+ <div class="SECT2">
+ <h2 class="SECT2"><a name="AF-PATTERNS" id="AF-PATTERNS">8.4.
+ Patterns</a></h2>
+
+ <p>As mentioned, <span class="APPLICATION">Privoxy</span> uses
+ <span class="QUOTE">"patterns"</span> to determine what <span class=
+ "emphasis"><i class="EMPHASIS">actions</i></span> might apply to which
+ sites and pages your browser attempts to access. These <span class=
+ "QUOTE">"patterns"</span> use wild card type <span class=
+ "emphasis"><i class="EMPHASIS">pattern</i></span> matching to achieve a
+ high degree of flexibility. This allows one expression to be expanded
+ and potentially match against many similar patterns.</p>
+
+ <p>Generally, an URL pattern has the form <tt class=
+ "LITERAL"><domain><port>/<path></tt>, where the
+ <tt class="LITERAL"><domain></tt>, the <tt class=
+ "LITERAL"><port></tt> and the <tt class=
+ "LITERAL"><path></tt> are optional. (This is why the special
+ <tt class="LITERAL">/</tt> pattern matches all URLs). Note that the
+ protocol portion of the URL pattern (e.g. <tt class=
+ "LITERAL">http://</tt>) should <span class="emphasis"><i class=
+ "EMPHASIS">not</i></span> be included in the pattern. This is assumed
+ already!</p>
+
+ <p>The pattern matching syntax is different for the domain and path
+ parts of the URL. The domain part uses a simple globbing type matching
+ technique, while the path part uses more flexible <a href=
+ "http://en.wikipedia.org/wiki/Regular_expressions" target=
+ "_top"><span class="QUOTE">"Regular Expressions"</span></a> (POSIX
+ 1003.2).</p>
+
+ <p>The port part of a pattern is a decimal port number preceded by a
+ colon (<tt class="LITERAL">:</tt>). If the domain part contains a
+ numerical IPv6 address, it has to be put into angle brackets
+ (<tt class="LITERAL"><</tt>, <tt class="LITERAL">></tt>).</p>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt><tt class="LITERAL">www.example.com/</tt></dt>
+
+ <dd>
+ <p>is a domain-only pattern and will match any request to
+ <tt class="LITERAL">www.example.com</tt>, regardless of which
+ document on that server is requested. So ALL pages in this domain
+ would be covered by the scope of this action. Note that a simple
+ <tt class="LITERAL">example.com</tt> is different and would NOT
+ match.</p>
+ </dd>
+
+ <dt><tt class="LITERAL">www.example.com</tt></dt>
+
+ <dd>
+ <p>means exactly the same. For domain-only patterns, the trailing
+ <tt class="LITERAL">/</tt> may be omitted.</p>
+ </dd>
+
+ <dt><tt class="LITERAL">www.example.com/index.html</tt></dt>
+
+ <dd>
+ <p>matches all the documents on <tt class=
+ "LITERAL">www.example.com</tt> whose name starts with <tt class=
+ "LITERAL">/index.html</tt>.</p>
+ </dd>
+
+ <dt><tt class="LITERAL">www.example.com/index.html$</tt></dt>
+
+ <dd>
+ <p>matches only the single document <tt class=
+ "LITERAL">/index.html</tt> on <tt class=
+ "LITERAL">www.example.com</tt>.</p>
+ </dd>
+
+ <dt><tt class="LITERAL">/index.html$</tt></dt>
+
+ <dd>
+ <p>matches the document <tt class="LITERAL">/index.html</tt>,
+ regardless of the domain, i.e. on <span class=
+ "emphasis"><i class="EMPHASIS">any</i></span> web server
+ anywhere.</p>
+ </dd>
+
+ <dt><tt class="LITERAL">/</tt></dt>
+
+ <dd>
+ <p>Matches any URL because there's no requirement for either the
+ domain or the path to match anything.</p>
+ </dd>
+
+ <dt><tt class="LITERAL">:8000/</tt></dt>
+
+ <dd>
+ <p>Matches any URL pointing to TCP port 8000.</p>
+ </dd>
+
+ <dt><tt class="LITERAL"><2001:db8::1>/</tt></dt>
+
+ <dd>
+ <p>Matches any URL with the host address <tt class=
+ "LITERAL">2001:db8::1</tt>. (Note that the real URL uses plain
+ brackets, not angle brackets.)</p>
+ </dd>
+
+ <dt><tt class="LITERAL">index.html</tt></dt>
+
+ <dd>
+ <p>matches nothing, since it would be interpreted as a domain
+ name and there is no top-level domain called <tt class=
+ "LITERAL">.html</tt>. So its a mistake.</p>
+ </dd>
+ </dl>
+ </div>
+
+ <div class="SECT3">
+ <h3 class="SECT3"><a name="AEN2995" id="AEN2995">8.4.1. The Domain
+ Pattern</a></h3>
+
+ <p>The matching of the domain part offers some flexible options: if
+ the domain starts or ends with a dot, it becomes unanchored at that
+ end. For example:</p>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt><tt class="LITERAL">.example.com</tt></dt>
+
+ <dd>
+ <p>matches any domain with first-level domain <tt class=
+ "LITERAL">com</tt> and second-level domain <tt class=
+ "LITERAL">example</tt>. For example <tt class=
+ "LITERAL">www.example.com</tt>, <tt class=
+ "LITERAL">example.com</tt> and <tt class=
+ "LITERAL">foo.bar.baz.example.com</tt>. Note that it wouldn't
+ match if the second-level domain was <tt class=
+ "LITERAL">another-example</tt>.</p>
+ </dd>
+
+ <dt><tt class="LITERAL">www.</tt></dt>
+
+ <dd>
+ <p>matches any domain that <span class="emphasis"><i class=
+ "EMPHASIS">STARTS</i></span> with <tt class="LITERAL">www.</tt>
+ (It also matches the domain <tt class="LITERAL">www</tt> but
+ most of the time that doesn't matter.)</p>
+ </dd>
+
+ <dt><tt class="LITERAL">.example.</tt></dt>
+
+ <dd>
+ <p>matches any domain that <span class="emphasis"><i class=
+ "EMPHASIS">CONTAINS</i></span> <tt class=
+ "LITERAL">.example.</tt>. And, by the way, also included would
+ be any files or documents that exist within that domain since
+ no path limitations are specified. (Correctly speaking: It
+ matches any FQDN that contains <tt class="LITERAL">example</tt>
+ as a domain.) This might be <tt class=
+ "LITERAL">www.example.com</tt>, <tt class=
+ "LITERAL">news.example.de</tt>, or <tt class=
+ "LITERAL">www.example.net/cgi/testing.pl</tt> for instance. All
+ these cases are matched.</p>
+ </dd>
+ </dl>
+ </div>
+
+ <p>Additionally, there are wild-cards that you can use in the domain
+ names themselves. These work similarly to shell globbing type
+ wild-cards: <span class="QUOTE">"*"</span> represents zero or more
+ arbitrary characters (this is equivalent to the <a href=
+ "http://en.wikipedia.org/wiki/Regular_expressions" target=
+ "_top"><span class="QUOTE">"Regular Expression"</span></a> based
+ syntax of <span class="QUOTE">".*"</span>), <span class=
+ "QUOTE">"?"</span> represents any single character (this is
+ equivalent to the regular expression syntax of a simple <span class=
+ "QUOTE">"."</span>), and you can define <span class=
+ "QUOTE">"character classes"</span> in square brackets which is
+ similar to the same regular expression technique. All of this can be
+ freely mixed:</p>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt><tt class="LITERAL">ad*.example.com</tt></dt>
+
+ <dd>
+ <p>matches <span class="QUOTE">"adserver.example.com"</span>,
+ <span class="QUOTE">"ads.example.com"</span>, etc but not
+ <span class="QUOTE">"sfads.example.com"</span></p>
+ </dd>
+
+ <dt><tt class="LITERAL">*ad*.example.com</tt></dt>
+
+ <dd>
+ <p>matches all of the above, and then some.</p>
+ </dd>
+
+ <dt><tt class="LITERAL">.?pix.com</tt></dt>
+
+ <dd>
+ <p>matches <tt class="LITERAL">www.ipix.com</tt>, <tt class=
+ "LITERAL">pictures.epix.com</tt>, <tt class=
+ "LITERAL">a.b.c.d.e.upix.com</tt> etc.</p>
+ </dd>
+
+ <dt><tt class="LITERAL">www[1-9a-ez].example.c*</tt></dt>
+
+ <dd>
+ <p>matches <tt class="LITERAL">www1.example.com</tt>,
+ <tt class="LITERAL">www4.example.cc</tt>, <tt class=
+ "LITERAL">wwwd.example.cy</tt>, <tt class=
+ "LITERAL">wwwz.example.com</tt> etc., but <span class=
+ "emphasis"><i class="EMPHASIS">not</i></span> <tt class=
+ "LITERAL">wwww.example.com</tt>.</p>
+ </dd>
+ </dl>
+ </div>
+
+ <p>While flexible, this is not the sophistication of full regular
+ expression based syntax.</p>
+ </div>
+
+ <div class="SECT3">
+ <h3 class="SECT3"><a name="AEN3071" id="AEN3071">8.4.2. The Path
+ Pattern</a></h3>
+
+ <p><span class="APPLICATION">Privoxy</span> uses <span class=
+ "QUOTE">"modern"</span> POSIX 1003.2 <a href=
+ "http://en.wikipedia.org/wiki/Regular_expressions" target=
+ "_top"><span class="QUOTE">"Regular Expressions"</span></a> for
+ matching the path portion (after the slash), and is thus more
+ flexible.</p>
+
+ <p>There is an <a href="appendix.html#REGEX">Appendix</a> with a
+ brief quick-start into regular expressions, you also might want to
+ have a look at your operating system's documentation on regular
+ expressions (try <tt class="LITERAL">man re_format</tt>).</p>
+
+ <p>Note that the path pattern is automatically left-anchored at the
+ <span class="QUOTE">"/"</span>, i.e. it matches as if it would start
+ with a <span class="QUOTE">"^"</span> (regular expression speak for
+ the beginning of a line).</p>
+
+ <p>Please also note that matching in the path is <span class=
+ "emphasis"><i class="EMPHASIS">CASE INSENSITIVE</i></span> by
+ default, but you can switch to case sensitive at any point in the
+ pattern by using the <span class="QUOTE">"(?-i)"</span> switch:
+ <tt class="LITERAL">www.example.com/(?-i)PaTtErN.*</tt> will match
+ only documents whose path starts with <tt class=
+ "LITERAL">PaTtErN</tt> in <span class="emphasis"><i class=
+ "EMPHASIS">exactly</i></span> this capitalization.</p>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt><tt class="LITERAL">.example.com/.*</tt></dt>
+
+ <dd>
+ <p>Is equivalent to just <span class=
+ "QUOTE">".example.com"</span>, since any documents within that
+ domain are matched with or without the <span class=
+ "QUOTE">".*"</span> regular expression. This is redundant</p>
+ </dd>
+
+ <dt><tt class="LITERAL">.example.com/.*/index.html$</tt></dt>
+
+ <dd>
+ <p>Will match any page in the domain of <span class=
+ "QUOTE">"example.com"</span> that is named <span class=
+ "QUOTE">"index.html"</span>, and that is part of some path. For
+ example, it matches <span class=
+ "QUOTE">"www.example.com/testing/index.html"</span> but NOT
+ <span class="QUOTE">"www.example.com/index.html"</span> because
+ the regular expression called for at least two <span class=
+ "QUOTE">"/'s"</span>, thus the path requirement. It also would
+ match <span class=
+ "QUOTE">"www.example.com/testing/index_html"</span>, because of
+ the special meta-character <span class="QUOTE">"."</span>.</p>
+ </dd>
+
+ <dt><tt class="LITERAL">.example.com/(.*/)?index\.html$</tt></dt>
+
+ <dd>
+ <p>This regular expression is conditional so it will match any
+ page named <span class="QUOTE">"index.html"</span> regardless
+ of path which in this case can have one or more <span class=
+ "QUOTE">"/'s"</span>. And this one must contain exactly
+ <span class="QUOTE">".html"</span> (but does not have to end
+ with that!).</p>
+ </dd>
+
+ <dt><tt class=
+ "LITERAL">.example.com/(.*/)(ads|banners?|junk)</tt></dt>
+
+ <dd>
+ <p>This regular expression will match any path of <span class=
+ "QUOTE">"example.com"</span> that contains any of the words
+ <span class="QUOTE">"ads"</span>, <span class=
+ "QUOTE">"banner"</span>, <span class="QUOTE">"banners"</span>
+ (because of the <span class="QUOTE">"?"</span>) or <span class=
+ "QUOTE">"junk"</span>. The path does not have to end in these
+ words, just contain them.</p>
+ </dd>
+
+ <dt><tt class=
+ "LITERAL">.example.com/(.*/)(ads|banners?|junk)/.*\.(jpe?g|gif|png)$</tt></dt>
+
+ <dd>
+ <p>This is very much the same as above, except now it must end
+ in either <span class="QUOTE">".jpg"</span>, <span class=
+ "QUOTE">".jpeg"</span>, <span class="QUOTE">".gif"</span> or
+ <span class="QUOTE">".png"</span>. So this one is limited to
+ common image formats.</p>
+ </dd>
+ </dl>
+ </div>
+
+ <p>There are many, many good examples to be found in <tt class=
+ "FILENAME">default.action</tt>, and more tutorials below in <a href=
+ "appendix.html#REGEX">Appendix on regular expressions</a>.</p>
+ </div>
+
+ <div class="SECT3">
+ <h3 class="SECT3"><a name="TAG-PATTERN" id="TAG-PATTERN">8.4.3. The
+ Tag Pattern</a></h3>
+
+ <p>Tag patterns are used to change the applying actions based on the
+ request's tags. Tags can be created with either the <a href=
+ "actions-file.html#CLIENT-HEADER-TAGGER">client-header-tagger</a> or
+ the <a href=
+ "actions-file.html#SERVER-HEADER-TAGGER">server-header-tagger</a>
+ action.</p>
+
+ <p>Tag patterns have to start with <span class="QUOTE">"TAG:"</span>,
+ so <span class="APPLICATION">Privoxy</span> can tell them apart from
+ URL patterns. Everything after the colon including white space, is
+ interpreted as a regular expression with path pattern syntax, except
+ that tag patterns aren't left-anchored automatically (<span class=
+ "APPLICATION">Privoxy</span> doesn't silently add a <span class=
+ "QUOTE">"^"</span>, you have to do it yourself if you need it).</p>
+
+ <p>To match all requests that are tagged with <span class=
+ "QUOTE">"foo"</span> your pattern line should be <span class=
+ "QUOTE">"TAG:^foo$"</span>, <span class="QUOTE">"TAG:foo"</span>
+ would work as well, but it would also match requests whose tags
+ contain <span class="QUOTE">"foo"</span> somewhere. <span class=
+ "QUOTE">"TAG: foo"</span> wouldn't work as it requires white
+ space.</p>
+
+ <p>Sections can contain URL and tag patterns at the same time, but
+ tag patterns are checked after the URL patterns and thus always
+ overrule them, even if they are located before the URL patterns.</p>
+
+ <p>Once a new tag is added, Privoxy checks right away if it's matched
+ by one of the tag patterns and updates the action settings
+ accordingly. As a result tags can be used to activate other tagger
+ actions, as long as these other taggers look for headers that haven't
+ already be parsed.</p>
+
+ <p>For example you could tag client requests which use the <tt class=
+ "LITERAL">POST</tt> method, then use this tag to activate another
+ tagger that adds a tag if cookies are sent, and then use a block
+ action based on the cookie tag. This allows the outcome of one
+ action, to be input into a subsequent action. However if you'd
+ reverse the position of the described taggers, and activated the
+ method tagger based on the cookie tagger, no method tags would be
+ created. The method tagger would look for the request line, but at
+ the time the cookie tag is created, the request line has already been
+ parsed.</p>
+
+ <p>While this is a limitation you should be aware of, this kind of
+ indirection is seldom needed anyway and even the example doesn't make
+ too much sense.</p>
+ </div>
+ </div>
+
+ <div class="SECT2">
+ <h2 class="SECT2"><a name="ACTIONS" id="ACTIONS">8.5. Actions</a></h2>
+
+ <p>All actions are disabled by default, until they are explicitly
+ enabled somewhere in an actions file. Actions are turned on if preceded
+ with a <span class="QUOTE">"+"</span>, and turned off if preceded with
+ a <span class="QUOTE">"-"</span>. So a <tt class="LITERAL">+action</tt>
+ means <span class="QUOTE">"do that action"</span>, e.g. <tt class=
+ "LITERAL">+block</tt> means <span class="QUOTE">"please block URLs that
+ match the following patterns"</span>, and <tt class=
+ "LITERAL">-block</tt> means <span class="QUOTE">"don't block URLs that
+ match the following patterns, even if <tt class="LITERAL">+block</tt>
+ previously applied."</span></p>
+
+ <p>Again, actions are invoked by placing them on a line, enclosed in
+ curly braces and separated by whitespace, like in <tt class=
+ "LITERAL">{+some-action -some-other-action{some-parameter}}</tt>,
+ followed by a list of URL patterns, one per line, to which they apply.
+ Together, the actions line and the following pattern lines make up a
+ section of the actions file.</p>
+
+ <p>Actions fall into three categories:</p>
+
+ <ul>
+ <li>
+ <p>Boolean, i.e the action can only be <span class=
+ "QUOTE">"enabled"</span> or <span class="QUOTE">"disabled"</span>.
+ Syntax:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+ +<tt class="REPLACEABLE"><i>name</i></tt> # enable action <tt class=
+"REPLACEABLE"><i>name</i></tt>
+ -<tt class=
+"REPLACEABLE"><i>name</i></tt> # disable action <tt class="REPLACEABLE"><i>name</i></tt>
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>Example: <tt class="LITERAL">+handle-as-image</tt></p>
+ </li>
+
+ <li>
+ <p>Parameterized, where some value is required in order to enable
+ this type of action. Syntax:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+ +<tt class="REPLACEABLE"><i>name</i></tt>{<tt class=
+"REPLACEABLE"><i>param</i></tt>} # enable action and set parameter to <tt class="REPLACEABLE"><i>param</i></tt>,
# overwriting parameter from previous match if necessary
- -<TT
-CLASS="REPLACEABLE"
-><I
->name</I
-></TT
-> # disable action. The parameter can be omitted</PRE
-></TD
-></TR
-></TABLE
->
- </P
-><P
-> Note that if the URL matches multiple positive forms of a parameterized action,
- the last match wins, i.e. the params from earlier matches are simply ignored.
- </P
-><P
->
- Example: <TT
-CLASS="LITERAL"
->+hide-user-agent{ Mozilla 1.0 }</TT
->
- </P
-></LI
-><LI
-><P
->
- Multi-value. These look exactly like parameterized actions,
- but they behave differently: If the action applies multiple times to the
- same URL, but with different parameters, <I
-CLASS="EMPHASIS"
->all</I
-> the parameters
- from <I
-CLASS="EMPHASIS"
->all</I
-> matches are remembered. This is used for actions
- that can be executed for the same request repeatedly, like adding multiple
- headers, or filtering through multiple filters. Syntax:
- </P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
-> +<TT
-CLASS="REPLACEABLE"
-><I
->name</I
-></TT
->{<TT
-CLASS="REPLACEABLE"
-><I
->param</I
-></TT
->} # enable action and add <TT
-CLASS="REPLACEABLE"
-><I
->param</I
-></TT
-> to the list of parameters
- -<TT
-CLASS="REPLACEABLE"
-><I
->name</I
-></TT
->{<TT
-CLASS="REPLACEABLE"
-><I
->param</I
-></TT
->} # remove the parameter <TT
-CLASS="REPLACEABLE"
-><I
->param</I
-></TT
-> from the list of parameters
+ -<tt class=
+"REPLACEABLE"><i>name</i></tt> # disable action. The parameter can be omitted
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>Note that if the URL matches multiple positive forms of a
+ parameterized action, the last match wins, i.e. the params from
+ earlier matches are simply ignored.</p>
+
+ <p>Example: <tt class="LITERAL">+hide-user-agent{Mozilla/5.0 (X11;
+ U; FreeBSD i386; en-US; rv:1.8.1.4) Gecko/20070602
+ Firefox/2.0.0.4}</tt></p>
+ </li>
+
+ <li>
+ <p>Multi-value. These look exactly like parameterized actions, but
+ they behave differently: If the action applies multiple times to
+ the same URL, but with different parameters, <span class=
+ "emphasis"><i class="EMPHASIS">all</i></span> the parameters from
+ <span class="emphasis"><i class="EMPHASIS">all</i></span> matches
+ are remembered. This is used for actions that can be executed for
+ the same request repeatedly, like adding multiple headers, or
+ filtering through multiple filters. Syntax:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+ +<tt class="REPLACEABLE"><i>name</i></tt>{<tt class=
+"REPLACEABLE"><i>param</i></tt>} # enable action and add <tt class=
+"REPLACEABLE"><i>param</i></tt> to the list of parameters
+ -<tt class="REPLACEABLE"><i>name</i></tt>{<tt class=
+"REPLACEABLE"><i>param</i></tt>} # remove the parameter <tt class=
+"REPLACEABLE"><i>param</i></tt> from the list of parameters
# If it was the last one left, disable the action.
- <TT
-CLASS="REPLACEABLE"
-><I
->-name</I
-></TT
-> # disable this action completely and remove all parameters from the list</PRE
-></TD
-></TR
-></TABLE
->
- </P
-><P
->
- Examples: <TT
-CLASS="LITERAL"
->+add-header{X-Fun-Header: Some text}</TT
-> and
- <TT
-CLASS="LITERAL"
->+filter{html-annoyances}</TT
->
- </P
-></LI
-></UL
-></P
-><P
-> If nothing is specified in any actions file, no <SPAN
-CLASS="QUOTE"
->"actions"</SPAN
-> are
- taken. So in this case <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> would just be a
- normal, non-blocking, non-anonymizing proxy. You must specifically enable the
- privacy and blocking features you need (although the provided default actions
- files will give a good starting point).</P
-><P
-> Later defined actions always over-ride earlier ones. So exceptions
- to any rules you make, should come in the latter part of the file (or
- in a file that is processed later when using multiple actions files). For
- multi-valued actions, the actions are applied in the order they are specified.
- Actions files are processed in the order they are defined in
- <TT
-CLASS="FILENAME"
->config</TT
-> (the default installation has three actions
- files). It also quite possible for any given URL pattern to match more than
- one pattern and thus more than one set of actions!</P
-><P
-> The list of valid <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> actions are:</P
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="ADD-HEADER"
->8.5.1. <I
-CLASS="EMPHASIS"
->add-header</I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
->Confuse log analysis, custom applications</P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> Sends a user defined HTTP header to the web server.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Multi-value.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-> Any string value is possible. Validity of the defined HTTP headers is not checked.
- It is recommended that you use the <SPAN
-CLASS="QUOTE"
->"<TT
-CLASS="LITERAL"
->X-</TT
->"</SPAN
-> prefix
- for custom headers.
- </P
-></DD
-><DT
->Notes:</DT
-><DD
-><P
-> This action may be specified multiple times, in order to define multiple
- headers. This is rarely needed for the typical user. If you don't know what
- <SPAN
-CLASS="QUOTE"
->"HTTP headers"</SPAN
-> are, you definitely don't need to worry about this
- one.
- </P
-></DD
-><DT
->Example usage:</DT
-><DD
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+add-header{X-User-Tracking: sucks}</PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="BLOCK"
->8.5.2. <I
-CLASS="EMPHASIS"
->block</I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
->Block ads or other obnoxious content</P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> Requests for URLs to which this action applies are blocked, i.e. the requests are not
- forwarded to the remote server, but answered locally with a substitute page or image,
- as determined by the <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#HANDLE-AS-IMAGE"
->handle-as-image</A
-></TT
->
- and <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#SET-IMAGE-BLOCKER"
->set-image-blocker</A
-></TT
-> actions.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Boolean.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
->N/A</P
-></DD
-><DT
->Notes:</DT
-><DD
-><P
-> <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> sends a special <SPAN
-CLASS="QUOTE"
->"BLOCKED"</SPAN
-> page
- for requests to blocked pages. This page contains links to find out why the request
- was blocked, and a click-through to the blocked content (the latter only if compiled with the
- force feature enabled). The <SPAN
-CLASS="QUOTE"
->"BLOCKED"</SPAN
-> page adapts to the available
- screen space -- it displays full-blown if space allows, or miniaturized and text-only
- if loaded into a small frame or window. If you are using <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->
- right now, you can take a look at the
- <A
-HREF="http://ads.bannerserver.example.com/nasty-ads/sponsor.html"
-TARGET="_top"
-><SPAN
-CLASS="QUOTE"
->"BLOCKED"</SPAN
->
- page</A
->.
- </P
-><P
->
- A very important exception occurs if <I
-CLASS="EMPHASIS"
->both</I
->
- <TT
-CLASS="LITERAL"
->block</TT
-> and <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#HANDLE-AS-IMAGE"
->handle-as-image</A
-></TT
->,
- apply to the same request: it will then be replaced by an image. If
- <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#SET-IMAGE-BLOCKER"
->set-image-blocker</A
-></TT
->
- (see below) also applies, the type of image will be determined by its parameter,
- if not, the standard checkerboard pattern is sent.
- </P
-><P
-> It is important to understand this process, in order
- to understand how <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> deals with
- ads and other unwanted content.
- </P
-><P
-> The <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#FILTER"
->filter</A
-></TT
->
- action can perform a very similar task, by <SPAN
-CLASS="QUOTE"
->"blocking"</SPAN
->
- banner images and other content through rewriting the relevant URLs in the
- document's HTML source, so they don't get requested in the first place.
- Note that this is a totally different technique, and it's easy to confuse the two.
- </P
-></DD
-><DT
->Example usage (section):</DT
-><DD
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->{+block} # Block and replace with "blocked" page
-.nasty-stuff.example.com
-
-{+block +handle-as-image} # Block and replace with image
-.ad.doubleclick.net
-.ads.r.us</PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="CRUNCH-INCOMING-COOKIES"
->8.5.3. <I
-CLASS="EMPHASIS"
->crunch-incoming-cookies</I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
-> Prevent the web server from setting any cookies on your system
- </P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> Deletes any <SPAN
-CLASS="QUOTE"
->"Set-Cookie:"</SPAN
-> HTTP headers from server replies.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Boolean.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-> N/A
- </P
-></DD
-><DT
->Notes:</DT
-><DD
-><P
-> This action is only concerned with <I
-CLASS="EMPHASIS"
->incoming</I
-> cookies. For
- <I
-CLASS="EMPHASIS"
->outgoing</I
-> cookies, use
- <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#CRUNCH-OUTGOING-COOKIES"
->crunch-outgoing-cookies</A
-></TT
->.
- Use <I
-CLASS="EMPHASIS"
->both</I
-> to disable cookies completely.
- </P
-><P
-> It makes <I
-CLASS="EMPHASIS"
->no sense at all</I
-> to use this action in conjunction
- with the <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#SESSION-COOKIES-ONLY"
->session-cookies-only</A
-></TT
-> action,
- since it would prevent the session cookies from being set.
- </P
-></DD
-><DT
->Example usage:</DT
-><DD
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+crunch-incoming-cookies</PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="CRUNCH-OUTGOING-COOKIES"
->8.5.4. <I
-CLASS="EMPHASIS"
->crunch-outgoing-cookies</I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
-> Prevent the web server from reading any cookies from your system
- </P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> Deletes any <SPAN
-CLASS="QUOTE"
->"Cookie:"</SPAN
-> HTTP headers from client requests.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Boolean.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-> N/A
- </P
-></DD
-><DT
->Notes:</DT
-><DD
-><P
-> This action is only concerned with <I
-CLASS="EMPHASIS"
->outgoing</I
-> cookies. For
- <I
-CLASS="EMPHASIS"
->incoming</I
-> cookies, use
- <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#CRUNCH-INCOMING-COOKIES"
->crunch-incoming-cookies</A
-></TT
->.
- Use <I
-CLASS="EMPHASIS"
->both</I
-> to disable cookies completely.
- </P
-><P
-> It makes <I
-CLASS="EMPHASIS"
->no sense at all</I
-> to use this action in conjunction
- with the <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#SESSION-COOKIES-ONLY"
->session-cookies-only</A
-></TT
-> action,
- since it would prevent the session cookies from being read.
- </P
-></DD
-><DT
->Example usage:</DT
-><DD
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+crunch-outgoing-cookies</PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="DEANIMATE-GIFS"
->8.5.5. <I
-CLASS="EMPHASIS"
->deanimate-gifs</I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
->Stop those annoying, distracting animated GIF images.</P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> De-animate GIF animations, i.e. reduce them to their first or last image.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Parameterized.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-> <SPAN
-CLASS="QUOTE"
->"last"</SPAN
-> or <SPAN
-CLASS="QUOTE"
->"first"</SPAN
->
- </P
-></DD
-><DT
->Notes:</DT
-><DD
-><P
-> This will also shrink the images considerably (in bytes, not pixels!). If
- the option <SPAN
-CLASS="QUOTE"
->"first"</SPAN
-> is given, the first frame of the animation
- is used as the replacement. If <SPAN
-CLASS="QUOTE"
->"last"</SPAN
-> is given, the last
- frame of the animation is used instead, which probably makes more sense for
- most banner animations, but also has the risk of not showing the entire
- last frame (if it is only a delta to an earlier frame).
- </P
-><P
-> You can safely use this action with patterns that will also match non-GIF
- objects, because no attempt will be made at anything that doesn't look like
- a GIF.
- </P
-></DD
-><DT
->Example usage:</DT
-><DD
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+deanimate-gifs{last}</PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="DOWNGRADE-HTTP-VERSION"
->8.5.6. <I
-CLASS="EMPHASIS"
->downgrade-http-version</I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
->Work around (very rare) problems with HTTP/1.1</P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Boolean.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-> N/A
- </P
-></DD
-><DT
->Notes:</DT
-><DD
-><P
-> This is a left-over from the time when <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->
- didn't support important HTTP/1.1 features well. It is left here for the
- unlikely case that you experience HTTP/1.1 related problems with some server
- out there. Not all (optional) HTTP/1.1 features are supported yet, so there
- is a chance you might need this action.
- </P
-></DD
-><DT
->Example usage (section):</DT
-><DD
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->{+downgrade-http-version}
-problem-host.example.com</PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="FAST-REDIRECTS"
->8.5.7. <I
-CLASS="EMPHASIS"
->fast-redirects</I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
->Fool some click-tracking scripts and speed up indirect links</P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> Cut off all but the last valid URL from requests.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Boolean.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-> N/A
- </P
-></DD
-><DT
->Notes:</DT
-><DD
-><P
->
- Many sites, like yahoo.com, don't just link to other sites. Instead, they
- will link to some script on their own servers, giving the destination as a
- parameter, which will then redirect you to the final target. URLs
- resulting from this scheme typically look like:
- <I
-CLASS="EMPHASIS"
->http://some.place/click-tracker.cgi?target=http://some.where.else</I
->.
- </P
-><P
-> Sometimes, there are even multiple consecutive redirects encoded in the
- URL. These redirections via scripts make your web browsing more traceable,
- since the server from which you follow such a link can see where you go
- to. Apart from that, valuable bandwidth and time is wasted, while your
- browser ask the server for one redirect after the other. Plus, it feeds
- the advertisers.
- </P
-><P
-> This feature is currently not very smart and is scheduled for improvement.
- It is likely to break some sites. You should expect to need possibly
- many exceptions to this action, if it is enabled by default in
- <TT
-CLASS="FILENAME"
->default.action</TT
->. Some sites just don't work without
- it.
- </P
-></DD
-><DT
->Example usage:</DT
-><DD
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->{+fast-redirects}</PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="FILTER"
->8.5.8. <I
-CLASS="EMPHASIS"
->filter</I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
->Get rid of HTML and JavaScript annoyances, banner advertisements (by size), do fun text replacements, etc.</P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> Text documents, including HTML and JavaScript, to which this action applies, are filtered on-the-fly
- through the specified regular expression based substitutions.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Parameterized.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-> The name of a filter, as defined in the <A
-HREF="filter-file.html"
->filter file</A
->
- (typically <TT
-CLASS="FILENAME"
->default.filter</TT
->, set by the
- <TT
-CLASS="LITERAL"
-><A
-HREF="config.html#FILTERFILE"
->filterfile</A
-></TT
->
- option in the <A
-HREF="config.html"
->config file</A
->)
- </P
-></DD
-><DT
->Notes:</DT
-><DD
-><P
-> For your convenience, there are a bunch of pre-defined filters available
- in the distribution filter file that you can use. See the example below for
- a list.
- </P
-><P
-> This is potentially a very powerful feature! But <SPAN
-CLASS="QUOTE"
->"rolling your own"</SPAN
->
- filters requires a knowledge of regular expressions and HTML.
- </P
-><P
-> Filtering requires buffering the page content, which may appear to
- slow down page rendering since nothing is displayed until all content has
- passed the filters. (It does not really take longer, but seems that way
- since the page is not incrementally displayed.) This effect will be more
- noticeable on slower connections.
- </P
-><P
-> At this time, <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> cannot (yet!) uncompress compressed
- documents. If you want filtering to work on all documents, even those that
- would normally be sent compressed, use the
- <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#PREVENT-COMPRESSION"
->prevent-compression</A
-></TT
->
- action in conjunction with <TT
-CLASS="LITERAL"
->filter</TT
->.
- </P
-><P
-> Filtering can achieve some of the effects as the
- <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#BLOCK"
->block</A
-></TT
->
- action, i.e. it can be used to block ads and banners.
- </P
-><P
-> <A
-HREF="contact.html"
->Feedback</A
-> with suggestions for new or improved filters is particularly
- welcome!
- </P
-></DD
-><DT
->Example usage (with filters from the distribution <TT
-CLASS="FILENAME"
->default.filter</TT
-> file):</DT
-><DD
-><P
-> <A
-NAME="FILTER-HTML-ANNOYANCES"
-></A
->
- <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+filter{html-annoyances} # Get rid of particularly annoying HTML abuse.</PRE
-></TD
-></TR
-></TABLE
->
- </P
-><P
-> <A
-NAME="FILTER-JS-ANNOYANCES"
-></A
->
- <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse</PRE
-></TD
-></TR
-></TABLE
->
- </P
-><P
-> <A
-NAME="FILTER-BANNERS-BY-SIZE"
-></A
->
- <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+filter{banners-by-size} # Kill banners by size (<I
-CLASS="EMPHASIS"
->very</I
-> efficient!)</PRE
-></TD
-></TR
-></TABLE
->
- </P
-><P
-> <A
-NAME="FILTER-CONTENT-COOKIES"
-></A
->
- <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+filter{content-cookies} # Kill cookies that come sneaking in the HTML or JS content</PRE
-></TD
-></TR
-></TABLE
->
- </P
-><P
-> <A
-NAME="FILTER-POPUPS"
-></A
->
- <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+filter{popups} # Kill all popups in JS and HTML</PRE
-></TD
-></TR
-></TABLE
->
- </P
-><P
-> <A
-NAME="FILTER-WEBBUGS"
-></A
->
- <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking)</PRE
-></TD
-></TR
-></TABLE
->
- </P
-><P
-> <A
-NAME="FILTER-FUN"
-></A
->
- <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+filter{fun} # Text replacements for subversive browsing fun!</PRE
-></TD
-></TR
-></TABLE
->
- </P
-><P
-> <A
-NAME="FILTER-FRAMESET-BORDERS"
-></A
->
- <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+filter{frameset-borders} # Give frames a border and make them resizeable</PRE
-></TD
-></TR
-></TABLE
->
- </P
-><P
-> <A
-NAME="FILTER-REFRESH-TAGS"
-></A
->
- <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups)</PRE
-></TD
-></TR
-></TABLE
->
- </P
-><P
-> <A
-NAME="FILTER-NIMDA"
-></A
->
- <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+filter{nimda} # Remove Nimda (virus) code.</PRE
-></TD
-></TR
-></TABLE
->
- </P
-><P
-> <A
-NAME="FILTER-SHOCKWAVE-FLASH"
-></A
->
- <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+filter{shockwave-flash} # Kill embedded Shockwave Flash objects</PRE
-></TD
-></TR
-></TABLE
->
- </P
-><P
-> <A
-NAME="FILTER-CRUDE-PARENTAL"
-></A
->
- <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+filter{crude-parental} # Kill all web pages that contain the words "sex" or "warez"</PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="HANDLE-AS-IMAGE"
->8.5.9. <I
-CLASS="EMPHASIS"
->handle-as-image</I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
->Mark URLs as belonging to images (so they'll be replaced by images <I
-CLASS="EMPHASIS"
->if they get blocked</I
->)</P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> This action alone doesn't do anything noticeable. It just marks URLs as images.
- If the <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#BLOCK"
->block</A
-></TT
-> action <I
-CLASS="EMPHASIS"
->also applies</I
->,
- the presence or absence of this mark decides whether an HTML <SPAN
-CLASS="QUOTE"
->"blocked"</SPAN
->
- page, or a replacement image (as determined by the <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#SET-IMAGE-BLOCKER"
->set-image-blocker</A
-></TT
-> action) will be sent to the
- client as a substitute for the blocked content.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Boolean.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-> N/A
- </P
-></DD
-><DT
->Notes:</DT
-><DD
-><P
-> The below generic example section is actually part of <TT
-CLASS="FILENAME"
->default.action</TT
->.
- It marks all URLs with well-known image file name extensions as images and should
- be left intact.
- </P
-><P
-> Users will probably only want to use the handle-as-image action in conjunction with
- <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#BLOCK"
->block</A
-></TT
->, to block sources of banners, whose URLs don't
- reflect the file type, like in the second example section.
- </P
-><P
-> Note that you cannot treat HTML pages as images in most cases. For instance, (inline) ad
- frames require an HTML page to be sent, or they won't display properly.
- Forcing <TT
-CLASS="LITERAL"
->handle-as-image</TT
-> in this situation will not replace the
- ad frame with an image, but lead to error messages.
- </P
-></DD
-><DT
->Example usage (sections):</DT
-><DD
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
-># Generic image extensions:
+ <tt class=
+"REPLACEABLE"><i>-name</i></tt> # disable this action completely and remove all parameters from the list
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>Examples: <tt class="LITERAL">+add-header{X-Fun-Header: Some
+ text}</tt> and <tt class=
+ "LITERAL">+filter{html-annoyances}</tt></p>
+ </li>
+ </ul>
+
+ <p>If nothing is specified in any actions file, no <span class=
+ "QUOTE">"actions"</span> are taken. So in this case <span class=
+ "APPLICATION">Privoxy</span> would just be a normal, non-blocking,
+ non-filtering proxy. You must specifically enable the privacy and
+ blocking features you need (although the provided default actions files
+ will give a good starting point).</p>
+
+ <p>Later defined action sections always over-ride earlier ones of the
+ same type. So exceptions to any rules you make, should come in the
+ latter part of the file (or in a file that is processed later when
+ using multiple actions files such as <tt class=
+ "FILENAME">user.action</tt>). For multi-valued actions, the actions are
+ applied in the order they are specified. Actions files are processed in
+ the order they are defined in <tt class="FILENAME">config</tt> (the
+ default installation has three actions files). It also quite possible
+ for any given URL to match more than one <span class=
+ "QUOTE">"pattern"</span> (because of wildcards and regular
+ expressions), and thus to trigger more than one set of actions! Last
+ match wins.</p>
+
+ <p>The list of valid <span class="APPLICATION">Privoxy</span> actions
+ are:</p>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="ADD-HEADER" id="ADD-HEADER">8.5.1.
+ add-header</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Confuse log analysis, custom applications</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Sends a user defined HTTP header to the web server.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Multi-value.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>Any string value is possible. Validity of the defined HTTP
+ headers is not checked. It is recommended that you use the
+ <span class="QUOTE">"<tt class="LITERAL">X-</tt>"</span> prefix
+ for custom headers.</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>This action may be specified multiple times, in order to
+ define multiple headers. This is rarely needed for the typical
+ user. If you don't know what <span class="QUOTE">"HTTP
+ headers"</span> are, you definitely don't need to worry about
+ this one.</p>
+
+ <p>Headers added by this action are not modified by other
+ actions.</p>
+ </dd>
+
+ <dt>Example usage:</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++add-header{X-User-Tracking: sucks}
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="BLOCK" id="BLOCK">8.5.2. block</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Block ads or other unwanted content</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Requests for URLs to which this action applies are blocked,
+ i.e. the requests are trapped by <span class=
+ "APPLICATION">Privoxy</span> and the requested URL is never
+ retrieved, but is answered locally with a substitute page or
+ image, as determined by the <tt class="LITERAL"><a href=
+ "actions-file.html#HANDLE-AS-IMAGE">handle-as-image</a></tt>,
+ <tt class="LITERAL"><a href=
+ "actions-file.html#SET-IMAGE-BLOCKER">set-image-blocker</a></tt>,
+ and <tt class="LITERAL"><a href=
+ "actions-file.html#HANDLE-AS-EMPTY-DOCUMENT">handle-as-empty-document</a></tt>
+ actions.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>A block reason that should be given to the user.</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p><span class="APPLICATION">Privoxy</span> sends a special
+ <span class="QUOTE">"BLOCKED"</span> page for requests to
+ blocked pages. This page contains the block reason given as
+ parameter, a link to find out why the block action applies, and
+ a click-through to the blocked content (the latter only if the
+ force feature is available and enabled).</p>
+
+ <p>A very important exception occurs if <span class=
+ "emphasis"><i class="EMPHASIS">both</i></span> <tt class=
+ "LITERAL">block</tt> and <tt class="LITERAL"><a href=
+ "actions-file.html#HANDLE-AS-IMAGE">handle-as-image</a></tt>,
+ apply to the same request: it will then be replaced by an
+ image. If <tt class="LITERAL"><a href=
+ "actions-file.html#SET-IMAGE-BLOCKER">set-image-blocker</a></tt>
+ (see below) also applies, the type of image will be determined
+ by its parameter, if not, the standard checkerboard pattern is
+ sent.</p>
+
+ <p>It is important to understand this process, in order to
+ understand how <span class="APPLICATION">Privoxy</span> deals
+ with ads and other unwanted content. Blocking is a core
+ feature, and one upon which various other features depend.</p>
+
+ <p>The <tt class="LITERAL"><a href=
+ "actions-file.html#FILTER">filter</a></tt> action can perform a
+ very similar task, by <span class="QUOTE">"blocking"</span>
+ banner images and other content through rewriting the relevant
+ URLs in the document's HTML source, so they don't get requested
+ in the first place. Note that this is a totally different
+ technique, and it's easy to confuse the two.</p>
+ </dd>
+
+ <dt>Example usage (section):</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+{+block{No nasty stuff for you.}}
+# Block and replace with "blocked" page
+ .nasty-stuff.example.com
+
+{+block{Doubleclick banners.} +handle-as-image}
+# Block and replace with image
+ .ad.doubleclick.net
+ .ads.r.us/banners/
+
+{+block{Layered ads.} +handle-as-empty-document}
+# Block and then ignore
+ adserver.example.net/.*\.js$
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="CHANGE-X-FORWARDED-FOR" id=
+ "CHANGE-X-FORWARDED-FOR">8.5.3. change-x-forwarded-for</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Improve privacy by not forwarding the source of the request
+ in the HTTP headers.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Deletes the <span class="QUOTE">"X-Forwarded-For:"</span>
+ HTTP header from the client request, or adds a new one.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <ul>
+ <li>
+ <p><span class="QUOTE">"block"</span> to delete the
+ header.</p>
+ </li>
+
+ <li>
+ <p><span class="QUOTE">"add"</span> to create the header
+ (or append the client's IP address to an already existing
+ one).</p>
+ </li>
+ </ul>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>It is safe and recommended to use <tt class=
+ "LITERAL">block</tt>.</p>
+
+ <p>Forwarding the source address of the request may make sense
+ in some multi-user setups but is also a privacy risk.</p>
+ </dd>
+
+ <dt>Example usage:</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++change-x-forwarded-for{block}
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="CLIENT-HEADER-FILTER" id=
+ "CLIENT-HEADER-FILTER">8.5.4. client-header-filter</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Rewrite or remove single client headers.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>All client headers to which this action applies are filtered
+ on-the-fly through the specified regular expression based
+ substitutions.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>The name of a client-header filter, as defined in one of the
+ <a href="filter-file.html">filter files</a>.</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>Client-header filters are applied to each header on its own,
+ not to all at once. This makes it easier to diagnose problems,
+ but on the downside you can't write filters that only change
+ header x if header y's value is z. You can do that by using
+ tags though.</p>
+
+ <p>Client-header filters are executed after the other header
+ actions have finished and use their output as input.</p>
+
+ <p>If the request URI gets changed, <span class=
+ "APPLICATION">Privoxy</span> will detect that and use the new
+ one. This can be used to rewrite the request destination behind
+ the client's back, for example to specify a Tor exit relay for
+ certain requests.</p>
+
+ <p>Please refer to the <a href="filter-file.html">filter file
+ chapter</a> to learn which client-header filters are available
+ by default, and how to create your own.</p>
+ </dd>
+
+ <dt>Example usage (section):</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Hide Tor exit notation in Host and Referer Headers
+{+client-header-filter{hide-tor-exit-notation}}
+/
+
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="CLIENT-HEADER-TAGGER" id=
+ "CLIENT-HEADER-TAGGER">8.5.5. client-header-tagger</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Block requests based on their headers.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Client headers to which this action applies are filtered
+ on-the-fly through the specified regular expression based
+ substitutions, the result is used as tag.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>The name of a client-header tagger, as defined in one of the
+ <a href="filter-file.html">filter files</a>.</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>Client-header taggers are applied to each header on its own,
+ and as the header isn't modified, each tagger <span class=
+ "QUOTE">"sees"</span> the original.</p>
+
+ <p>Client-header taggers are the first actions that are
+ executed and their tags can be used to control every other
+ action.</p>
+ </dd>
+
+ <dt>Example usage (section):</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Tag every request with the User-Agent header
+{+client-header-tagger{user-agent}}
+/
+
+# Tagging itself doesn't change the action
+# settings, sections with TAG patterns do:
+#
+# If it's a download agent, use a different forwarding proxy,
+# show the real User-Agent and make sure resume works.
+{+forward-override{forward-socks5 10.0.0.2:2222 .} \
+ -hide-if-modified-since \
+ -overwrite-last-modified \
+ -hide-user-agent \
+ -filter \
+ -deanimate-gifs \
+}
+TAG:^User-Agent: NetBSD-ftp/
+TAG:^User-Agent: Novell ZYPP Installer
+TAG:^User-Agent: RPM APT-HTTP/
+TAG:^User-Agent: fetch libfetch/
+TAG:^User-Agent: Ubuntu APT-HTTP/
+TAG:^User-Agent: MPlayer/
+
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Tag all requests with the Range header set
+{+client-header-tagger{range-requests}}
+/
+
+# Disable filtering for the tagged requests.
+#
+# With filtering enabled Privoxy would remove the Range headers
+# to be able to filter the whole response. The downside is that
+# it prevents clients from resuming downloads or skipping over
+# parts of multimedia files.
+{-filter -deanimate-gifs}
+TAG:^RANGE-REQUEST$
+
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="CONTENT-TYPE-OVERWRITE" id=
+ "CONTENT-TYPE-OVERWRITE">8.5.6. content-type-overwrite</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Stop useless download menus from popping up, or change the
+ browser's rendering mode</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Replaces the <span class="QUOTE">"Content-Type:"</span> HTTP
+ server header.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>Any string.</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>The <span class="QUOTE">"Content-Type:"</span> HTTP server
+ header is used by the browser to decide what to do with the
+ document. The value of this header can cause the browser to
+ open a download menu instead of displaying the document by
+ itself, even if the document's format is supported by the
+ browser.</p>
+
+ <p>The declared content type can also affect which rendering
+ mode the browser chooses. If XHTML is delivered as <span class=
+ "QUOTE">"text/html"</span>, many browsers treat it as yet
+ another broken HTML document. If it is send as <span class=
+ "QUOTE">"application/xml"</span>, browsers with XHTML support
+ will only display it, if the syntax is correct.</p>
+
+ <p>If you see a web site that proudly uses XHTML buttons, but
+ sets <span class="QUOTE">"Content-Type: text/html"</span>, you
+ can use <span class="APPLICATION">Privoxy</span> to overwrite
+ it with <span class="QUOTE">"application/xml"</span> and
+ validate the web master's claim inside your XHTML-supporting
+ browser. If the syntax is incorrect, the browser will complain
+ loudly.</p>
+
+ <p>You can also go the opposite direction: if your browser
+ prints error messages instead of rendering a document falsely
+ declared as XHTML, you can overwrite the content type with
+ <span class="QUOTE">"text/html"</span> and have it rendered as
+ broken HTML document.</p>
+
+ <p>By default <tt class="LITERAL">content-type-overwrite</tt>
+ only replaces <span class="QUOTE">"Content-Type:"</span>
+ headers that look like some kind of text. If you want to
+ overwrite it unconditionally, you have to combine it with
+ <tt class="LITERAL"><a href=
+ "actions-file.html#FORCE-TEXT-MODE">force-text-mode</a></tt>.
+ This limitation exists for a reason, think twice before
+ circumventing it.</p>
+
+ <p>Most of the time it's easier to replace this action with a
+ custom <tt class="LITERAL"><a href=
+ "actions-file.html#SERVER-HEADER-FILTER">server-header
+ filter</a></tt>. It allows you to activate it for every
+ document of a certain site and it will still only replace the
+ content types you aimed at.</p>
+
+ <p>Of course you can apply <tt class=
+ "LITERAL">content-type-overwrite</tt> to a whole site and then
+ make URL based exceptions, but it's a lot more work to get the
+ same precision.</p>
+ </dd>
+
+ <dt>Example usage (sections):</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Check if www.example.net/ really uses valid XHTML
+{ +content-type-overwrite{application/xml} }
+www.example.net/
+
+# but leave the content type unmodified if the URL looks like a style sheet
+{-content-type-overwrite}
+www.example.net/.*\.css$
+www.example.net/.*style
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="CRUNCH-CLIENT-HEADER" id=
+ "CRUNCH-CLIENT-HEADER">8.5.7. crunch-client-header</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Remove a client header <span class=
+ "APPLICATION">Privoxy</span> has no dedicated action for.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Deletes every header sent by the client that contains the
+ string the user supplied as parameter.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>Any string.</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>This action allows you to block client headers for which no
+ dedicated <span class="APPLICATION">Privoxy</span> action
+ exists. <span class="APPLICATION">Privoxy</span> will remove
+ every client header that contains the string you supplied as
+ parameter.</p>
+
+ <p>Regular expressions are <span class="emphasis"><i class=
+ "EMPHASIS">not supported</i></span> and you can't use this
+ action to block different headers in the same request, unless
+ they contain the same string.</p>
+
+ <p><tt class="LITERAL">crunch-client-header</tt> is only meant
+ for quick tests. If you have to block several different
+ headers, or only want to modify parts of them, you should use a
+ <tt class="LITERAL"><a href=
+ "actions-file.html#CLIENT-HEADER-FILTER">client-header
+ filter</a></tt>.</p>
+
+ <div class="WARNING">
+ <table class="WARNING" border="1" width="90%">
+ <tr>
+ <td align="center"><b>Warning</b></td>
+ </tr>
+
+ <tr>
+ <td align="left">
+ <p>Don't block any header without understanding the
+ consequences.</p>
+ </td>
+ </tr>
+ </table>
+ </div>
+ </dd>
+
+ <dt>Example usage (section):</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Block the non-existent "Privacy-Violation:" client header
+{ +crunch-client-header{Privacy-Violation:} }
+/
+
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="CRUNCH-IF-NONE-MATCH" id=
+ "CRUNCH-IF-NONE-MATCH">8.5.8. crunch-if-none-match</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Prevent yet another way to track the user's steps between
+ sessions.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Deletes the <span class="QUOTE">"If-None-Match:"</span> HTTP
+ client header.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Boolean.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>N/A</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>Removing the <span class="QUOTE">"If-None-Match:"</span>
+ HTTP client header is useful for filter testing, where you want
+ to force a real reload instead of getting status code
+ <span class="QUOTE">"304"</span> which would cause the browser
+ to use a cached copy of the page.</p>
+
+ <p>It is also useful to make sure the header isn't used as a
+ cookie replacement (unlikely but possible).</p>
+
+ <p>Blocking the <span class="QUOTE">"If-None-Match:"</span>
+ header shouldn't cause any caching problems, as long as the
+ <span class="QUOTE">"If-Modified-Since:"</span> header isn't
+ blocked or missing as well.</p>
+
+ <p>It is recommended to use this action together with
+ <tt class="LITERAL"><a href=
+ "actions-file.html#HIDE-IF-MODIFIED-SINCE">hide-if-modified-since</a></tt>
+ and <tt class="LITERAL"><a href=
+ "actions-file.html#OVERWRITE-LAST-MODIFIED">overwrite-last-modified</a></tt>.</p>
+ </dd>
+
+ <dt>Example usage (section):</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Let the browser revalidate cached documents but don't
+# allow the server to use the revalidation headers for user tracking.
+{+hide-if-modified-since{-60} \
+ +overwrite-last-modified{randomize} \
+ +crunch-if-none-match}
+/
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="CRUNCH-INCOMING-COOKIES" id=
+ "CRUNCH-INCOMING-COOKIES">8.5.9. crunch-incoming-cookies</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Prevent the web server from setting HTTP cookies on your
+ system</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Deletes any <span class="QUOTE">"Set-Cookie:"</span> HTTP
+ headers from server replies.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Boolean.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>N/A</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>This action is only concerned with <span class=
+ "emphasis"><i class="EMPHASIS">incoming</i></span> HTTP
+ cookies. For <span class="emphasis"><i class=
+ "EMPHASIS">outgoing</i></span> HTTP cookies, use <tt class=
+ "LITERAL"><a href=
+ "actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</a></tt>.
+ Use <span class="emphasis"><i class="EMPHASIS">both</i></span>
+ to disable HTTP cookies completely.</p>
+
+ <p>It makes <span class="emphasis"><i class="EMPHASIS">no sense
+ at all</i></span> to use this action in conjunction with the
+ <tt class="LITERAL"><a href=
+ "actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</a></tt>
+ action, since it would prevent the session cookies from being
+ set. See also <tt class="LITERAL"><a href=
+ "actions-file.html#FILTER-CONTENT-COOKIES">filter-content-cookies</a></tt>.</p>
+ </dd>
+
+ <dt>Example usage:</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++crunch-incoming-cookies
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="CRUNCH-SERVER-HEADER" id=
+ "CRUNCH-SERVER-HEADER">8.5.10. crunch-server-header</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Remove a server header <span class=
+ "APPLICATION">Privoxy</span> has no dedicated action for.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Deletes every header sent by the server that contains the
+ string the user supplied as parameter.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>Any string.</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>This action allows you to block server headers for which no
+ dedicated <span class="APPLICATION">Privoxy</span> action
+ exists. <span class="APPLICATION">Privoxy</span> will remove
+ every server header that contains the string you supplied as
+ parameter.</p>
+
+ <p>Regular expressions are <span class="emphasis"><i class=
+ "EMPHASIS">not supported</i></span> and you can't use this
+ action to block different headers in the same request, unless
+ they contain the same string.</p>
+
+ <p><tt class="LITERAL">crunch-server-header</tt> is only meant
+ for quick tests. If you have to block several different
+ headers, or only want to modify parts of them, you should use a
+ custom <tt class="LITERAL"><a href=
+ "actions-file.html#SERVER-HEADER-FILTER">server-header
+ filter</a></tt>.</p>
+
+ <div class="WARNING">
+ <table class="WARNING" border="1" width="90%">
+ <tr>
+ <td align="center"><b>Warning</b></td>
+ </tr>
+
+ <tr>
+ <td align="left">
+ <p>Don't block any header without understanding the
+ consequences.</p>
+ </td>
+ </tr>
+ </table>
+ </div>
+ </dd>
+
+ <dt>Example usage (section):</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Crunch server headers that try to prevent caching
+{ +crunch-server-header{no-cache} }
+/
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="CRUNCH-OUTGOING-COOKIES" id=
+ "CRUNCH-OUTGOING-COOKIES">8.5.11. crunch-outgoing-cookies</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Prevent the web server from reading any HTTP cookies from
+ your system</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Deletes any <span class="QUOTE">"Cookie:"</span> HTTP
+ headers from client requests.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Boolean.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>N/A</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>This action is only concerned with <span class=
+ "emphasis"><i class="EMPHASIS">outgoing</i></span> HTTP
+ cookies. For <span class="emphasis"><i class=
+ "EMPHASIS">incoming</i></span> HTTP cookies, use <tt class=
+ "LITERAL"><a href=
+ "actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</a></tt>.
+ Use <span class="emphasis"><i class="EMPHASIS">both</i></span>
+ to disable HTTP cookies completely.</p>
+
+ <p>It makes <span class="emphasis"><i class="EMPHASIS">no sense
+ at all</i></span> to use this action in conjunction with the
+ <tt class="LITERAL"><a href=
+ "actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</a></tt>
+ action, since it would prevent the session cookies from being
+ read.</p>
+ </dd>
+
+ <dt>Example usage:</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++crunch-outgoing-cookies
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="DEANIMATE-GIFS" id=
+ "DEANIMATE-GIFS">8.5.12. deanimate-gifs</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Stop those annoying, distracting animated GIF images.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>De-animate GIF animations, i.e. reduce them to their first
+ or last image.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p><span class="QUOTE">"last"</span> or <span class=
+ "QUOTE">"first"</span></p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>This will also shrink the images considerably (in bytes, not
+ pixels!). If the option <span class="QUOTE">"first"</span> is
+ given, the first frame of the animation is used as the
+ replacement. If <span class="QUOTE">"last"</span> is given, the
+ last frame of the animation is used instead, which probably
+ makes more sense for most banner animations, but also has the
+ risk of not showing the entire last frame (if it is only a
+ delta to an earlier frame).</p>
+
+ <p>You can safely use this action with patterns that will also
+ match non-GIF objects, because no attempt will be made at
+ anything that doesn't look like a GIF.</p>
+ </dd>
+
+ <dt>Example usage:</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++deanimate-gifs{last}
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="DOWNGRADE-HTTP-VERSION" id=
+ "DOWNGRADE-HTTP-VERSION">8.5.13. downgrade-http-version</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Work around (very rare) problems with HTTP/1.1</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Downgrades HTTP/1.1 client requests and server replies to
+ HTTP/1.0.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Boolean.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>N/A</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>This is a left-over from the time when <span class=
+ "APPLICATION">Privoxy</span> didn't support important HTTP/1.1
+ features well. It is left here for the unlikely case that you
+ experience HTTP/1.1-related problems with some server out
+ there.</p>
+
+ <p>Note that enabling this action is only a workaround. It
+ should not be enabled for sites that work without it. While it
+ shouldn't break any pages, it has an (usually negative)
+ performance impact.</p>
+
+ <p>If you come across a site where enabling this action helps,
+ please report it, so the cause of the problem can be analyzed.
+ If the problem turns out to be caused by a bug in <span class=
+ "APPLICATION">Privoxy</span> it should be fixed so the
+ following release works without the work around.</p>
+ </dd>
+
+ <dt>Example usage (section):</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+{+downgrade-http-version}
+problem-host.example.com
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="FAST-REDIRECTS" id=
+ "FAST-REDIRECTS">8.5.14. fast-redirects</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Fool some click-tracking scripts and speed up indirect
+ links.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Detects redirection URLs and redirects the browser without
+ contacting the redirection server first.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <ul>
+ <li>
+ <p><span class="QUOTE">"simple-check"</span> to just search
+ for the string <span class="QUOTE">"http://"</span> to
+ detect redirection URLs.</p>
+ </li>
+
+ <li>
+ <p><span class="QUOTE">"check-decoded-url"</span> to decode
+ URLs (if necessary) before searching for redirection
+ URLs.</p>
+ </li>
+ </ul>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>Many sites, like yahoo.com, don't just link to other sites.
+ Instead, they will link to some script on their own servers,
+ giving the destination as a parameter, which will then redirect
+ you to the final target. URLs resulting from this scheme
+ typically look like: <span class=
+ "QUOTE">"http://www.example.org/click-tracker.cgi?target=http%3a//www.example.net/"</span>.</p>
+
+ <p>Sometimes, there are even multiple consecutive redirects
+ encoded in the URL. These redirections via scripts make your
+ web browsing more traceable, since the server from which you
+ follow such a link can see where you go to. Apart from that,
+ valuable bandwidth and time is wasted, while your browser asks
+ the server for one redirect after the other. Plus, it feeds the
+ advertisers.</p>
+
+ <p>This feature is currently not very smart and is scheduled
+ for improvement. If it is enabled by default, you will have to
+ create some exceptions to this action. It can lead to failures
+ in several ways:</p>
+
+ <p>Not every URLs with other URLs as parameters is evil. Some
+ sites offer a real service that requires this information to
+ work. For example a validation service needs to know, which
+ document to validate. <tt class="LITERAL">fast-redirects</tt>
+ assumes that every URL parameter that looks like another URL is
+ a redirection target, and will always redirect to the last one.
+ Most of the time the assumption is correct, but if it isn't,
+ the user gets redirected anyway.</p>
+
+ <p>Another failure occurs if the URL contains other parameters
+ after the URL parameter. The URL: <span class=
+ "QUOTE">"http://www.example.org/?redirect=http%3a//www.example.net/&foo=bar"</span>.
+ contains the redirection URL <span class=
+ "QUOTE">"http://www.example.net/"</span>, followed by another
+ parameter. <tt class="LITERAL">fast-redirects</tt> doesn't know
+ that and will cause a redirect to <span class=
+ "QUOTE">"http://www.example.net/&foo=bar"</span>. Depending
+ on the target server configuration, the parameter will be
+ silently ignored or lead to a <span class="QUOTE">"page not
+ found"</span> error. You can prevent this problem by first
+ using the <tt class="LITERAL"><a href=
+ "actions-file.html#REDIRECT">redirect</a></tt> action to remove
+ the last part of the URL, but it requires a little effort.</p>
+
+ <p>To detect a redirection URL, <tt class=
+ "LITERAL">fast-redirects</tt> only looks for the string
+ <span class="QUOTE">"http://"</span>, either in plain text
+ (invalid but often used) or encoded as <span class=
+ "QUOTE">"http%3a//"</span>. Some sites use their own URL
+ encoding scheme, encrypt the address of the target server or
+ replace it with a database id. In theses cases <tt class=
+ "LITERAL">fast-redirects</tt> is fooled and the request reaches
+ the redirection server where it probably gets logged.</p>
+ </dd>
+
+ <dt>Example usage:</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+ { +fast-redirects{simple-check} }
+ one.example.com
+
+ { +fast-redirects{check-decoded-url} }
+ another.example.com/testing
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="FILTER" id="FILTER">8.5.15.
+ filter</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Get rid of HTML and JavaScript annoyances, banner
+ advertisements (by size), do fun text replacements, add
+ personalized effects, etc.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>All instances of text-based type, most notably HTML and
+ JavaScript, to which this action applies, can be filtered
+ on-the-fly through the specified regular expression based
+ substitutions. (Note: as of version 3.0.3 plain text documents
+ are exempted from filtering, because web servers often use the
+ <tt class="LITERAL">text/plain</tt> MIME type for all files
+ whose type they don't know.)</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>The name of a content filter, as defined in the <a href=
+ "filter-file.html">filter file</a>. Filters can be defined in
+ one or more files as defined by the <tt class=
+ "LITERAL"><a href="config.html#FILTERFILE">filterfile</a></tt>
+ option in the <a href="config.html">config file</a>. <tt class=
+ "FILENAME">default.filter</tt> is the collection of filters
+ supplied by the developers. Locally defined filters should go
+ in their own file, such as <tt class=
+ "FILENAME">user.filter</tt>.</p>
+
+ <p>When used in its negative form, and without parameters,
+ <span class="emphasis"><i class="EMPHASIS">all</i></span>
+ filtering is completely disabled.</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>For your convenience, there are a number of pre-defined
+ filters available in the distribution filter file that you can
+ use. See the examples below for a list.</p>
+
+ <p>Filtering requires buffering the page content, which may
+ appear to slow down page rendering since nothing is displayed
+ until all content has passed the filters. (The total time until
+ the page is completely rendered doesn't change much, but it may
+ be perceived as slower since the page is not incrementally
+ displayed.) This effect will be more noticeable on slower
+ connections.</p>
+
+ <p><span class="QUOTE">"Rolling your own"</span> filters
+ requires a knowledge of <a href=
+ "http://en.wikipedia.org/wiki/Regular_expressions" target=
+ "_top"><span class="QUOTE">"Regular Expressions"</span></a> and
+ <a href="http://en.wikipedia.org/wiki/Html" target=
+ "_top"><span class="QUOTE">"HTML"</span></a>. This is very
+ powerful feature, and potentially very intrusive. Filters
+ should be used with caution, and where an equivalent
+ <span class="QUOTE">"action"</span> is not available.</p>
+
+ <p>The amount of data that can be filtered is limited to the
+ <tt class="LITERAL"><a href=
+ "config.html#BUFFER-LIMIT">buffer-limit</a></tt> option in the
+ main <a href="config.html">config file</a>. The default is 4096
+ KB (4 Megs). Once this limit is exceeded, the buffered data,
+ and all pending data, is passed through unfiltered.</p>
+
+ <p>Inappropriate MIME types, such as zipped files, are not
+ filtered at all. (Again, only text-based types except plain
+ text). Encrypted SSL data (from HTTPS servers) cannot be
+ filtered either, since this would violate the integrity of the
+ secure transaction. In some situations it might be necessary to
+ protect certain text, like source code, from filtering by
+ defining appropriate <tt class="LITERAL">-filter</tt>
+ exceptions.</p>
+
+ <p>Compressed content can't be filtered either, but if
+ <span class="APPLICATION">Privoxy</span> is compiled with zlib
+ support and a supported compression algorithm is used (gzip or
+ deflate), <span class="APPLICATION">Privoxy</span> can first
+ decompress the content and then filter it.</p>
+
+ <p>If you use a <span class="APPLICATION">Privoxy</span>
+ version without zlib support, but want filtering to work on as
+ much documents as possible, even those that would normally be
+ sent compressed, you must use the <tt class="LITERAL"><a href=
+ "actions-file.html#PREVENT-COMPRESSION">prevent-compression</a></tt>
+ action in conjunction with <tt class="LITERAL">filter</tt>.</p>
+
+ <p>Content filtering can achieve some of the same effects as
+ the <tt class="LITERAL"><a href=
+ "actions-file.html#BLOCK">block</a></tt> action, i.e. it can be
+ used to block ads and banners. But the mechanism works quite
+ differently. One effective use, is to block ad banners based on
+ their size (see below), since many of these seem to be somewhat
+ standardized.</p>
+
+ <p><a href="contact.html">Feedback</a> with suggestions for new
+ or improved filters is particularly welcome!</p>
+
+ <p>The below list has only the names and a one-line description
+ of each predefined filter. There are <a href=
+ "filter-file.html#PREDEFINED-FILTERS">more verbose
+ explanations</a> of what these filters do in the <a href=
+ "filter-file.html">filter file chapter</a>.</p>
+ </dd>
+
+ <dt>Example usage (with filters from the distribution <tt class=
+ "FILENAME">default.filter</tt> file). See <a href=
+ "filter-file.html#PREDEFINED-FILTERS">the Predefined Filters
+ section</a> for more explanation on each:</dt>
+
+ <dd>
+ <p><a name="FILTER-JS-ANNOYANCES" id=
+ "FILTER-JS-ANNOYANCES"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-JS-EVENTS" id="FILTER-JS-EVENTS"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{js-events} # Kill all JS event bindings and timers (Radically destructive! Only for extra nasty sites).
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-HTML-ANNOYANCES" id=
+ "FILTER-HTML-ANNOYANCES"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{html-annoyances} # Get rid of particularly annoying HTML abuse.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-CONTENT-COOKIES" id=
+ "FILTER-CONTENT-COOKIES"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{content-cookies} # Kill cookies that come in the HTML or JS content.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-REFRESH-TAGS" id=
+ "FILTER-REFRESH-TAGS"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups).
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-UNSOLICITED-POPUPS" id=
+ "FILTER-UNSOLICITED-POPUPS"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{unsolicited-popups} # Disable only unsolicited pop-up windows. Useful if your browser lacks this ability.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-ALL-POPUPS" id="FILTER-ALL-POPUPS"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{all-popups} # Kill all popups in JavaScript and HTML. Useful if your browser lacks this ability.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-IMG-REORDER" id=
+ "FILTER-IMG-REORDER"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-BANNERS-BY-SIZE" id=
+ "FILTER-BANNERS-BY-SIZE"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{banners-by-size} # Kill banners by size.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-BANNERS-BY-LINK" id=
+ "FILTER-BANNERS-BY-LINK"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{banners-by-link} # Kill banners by their links to known clicktrackers.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-WEBBUGS" id="FILTER-WEBBUGS"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking).
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-TINY-TEXTFORMS" id=
+ "FILTER-TINY-TEXTFORMS"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-JUMPING-WINDOWS" id=
+ "FILTER-JUMPING-WINDOWS"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{jumping-windows} # Prevent windows from resizing and moving themselves.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-FRAMESET-BORDERS" id=
+ "FILTER-FRAMESET-BORDERS"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{frameset-borders} # Give frames a border and make them resizable.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-DEMORONIZER" id=
+ "FILTER-DEMORONIZER"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{demoronizer} # Fix MS's non-standard use of standard charsets.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-SHOCKWAVE-FLASH" id=
+ "FILTER-SHOCKWAVE-FLASH"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{shockwave-flash} # Kill embedded Shockwave Flash objects.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-QUICKTIME-KIOSKMODE" id=
+ "FILTER-QUICKTIME-KIOSKMODE"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{quicktime-kioskmode} # Make Quicktime movies saveable.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-FUN" id="FILTER-FUN"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{fun} # Text replacements for subversive browsing fun!
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-CRUDE-PARENTAL" id=
+ "FILTER-CRUDE-PARENTAL"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{crude-parental} # Crude parental filtering. Note that this filter doesn't work reliably.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-IE-EXPLOITS" id=
+ "FILTER-IE-EXPLOITS"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{ie-exploits} # Disable some known Internet Explorer bug exploits.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-SITE-SPECIFICS" id=
+ "FILTER-SITE-SPECIFICS"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{site-specifics} # Cure for site-specific problems. Don't apply generally!
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-NO-PING" id="FILTER-NO-PING"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{no-ping} # Removes non-standard ping attributes in <a> and <area> tags.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-GOOGLE" id="FILTER-GOOGLE"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{google} # CSS-based block for Google text ads. Also removes a width limitation and the toolbar advertisement.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-YAHOO" id="FILTER-YAHOO"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{yahoo} # CSS-based block for Yahoo text ads. Also removes a width limitation.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-MSN" id="FILTER-MSN"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{msn} # CSS-based block for MSN text ads. Also removes tracking URLs and a width limitation.
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><a name="FILTER-BLOGSPOT" id="FILTER-BLOGSPOT"></a></p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++filter{blogspot} # Cleans up some Blogspot blogs. Read the fine print before using this.
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="FORCE-TEXT-MODE" id=
+ "FORCE-TEXT-MODE">8.5.16. force-text-mode</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Force <span class="APPLICATION">Privoxy</span> to treat a
+ document as if it was in some kind of <span class=
+ "emphasis"><i class="EMPHASIS">text</i></span> format.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Declares a document as text, even if the <span class=
+ "QUOTE">"Content-Type:"</span> isn't detected as such.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Boolean.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>N/A</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>As explained <tt class="LITERAL"><a href=
+ "actions-file.html#FILTER">above</a></tt>, <span class=
+ "APPLICATION">Privoxy</span> tries to only filter files that
+ are in some kind of text format. The same restrictions apply to
+ <tt class="LITERAL"><a href=
+ "actions-file.html#CONTENT-TYPE-OVERWRITE">content-type-overwrite</a></tt>.
+ <tt class="LITERAL">force-text-mode</tt> declares a document as
+ text, without looking at the <span class=
+ "QUOTE">"Content-Type:"</span> first.</p>
+
+ <div class="WARNING">
+ <table class="WARNING" border="1" width="90%">
+ <tr>
+ <td align="center"><b>Warning</b></td>
+ </tr>
+
+ <tr>
+ <td align="left">
+ <p>Think twice before activating this action. Filtering
+ binary data with regular expressions can cause file
+ damage.</p>
+ </td>
+ </tr>
+ </table>
+ </div>
+ </dd>
+
+ <dt>Example usage:</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++force-text-mode
+
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="FORWARD-OVERRIDE" id=
+ "FORWARD-OVERRIDE">8.5.17. forward-override</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Change the forwarding settings based on User-Agent or
+ request origin</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Overrules the forward directives in the configuration
+ file.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Multi-value.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <ul>
+ <li>
+ <p><span class="QUOTE">"forward ."</span> to use a direct
+ connection without any additional proxies.</p>
+ </li>
+
+ <li>
+ <p><span class="QUOTE">"forward 127.0.0.1:8123"</span> to
+ use the HTTP proxy listening at 127.0.0.1 port 8123.</p>
+ </li>
+
+ <li>
+ <p><span class="QUOTE">"forward-socks4a 127.0.0.1:9050
+ ."</span> to use the socks4a proxy listening at 127.0.0.1
+ port 9050. Replace <span class=
+ "QUOTE">"forward-socks4a"</span> with <span class=
+ "QUOTE">"forward-socks4"</span> to use a socks4 connection
+ (with local DNS resolution) instead, use <span class=
+ "QUOTE">"forward-socks5"</span> for socks5 connections
+ (with remote DNS resolution).</p>
+ </li>
+
+ <li>
+ <p><span class="QUOTE">"forward-socks4a 127.0.0.1:9050
+ proxy.example.org:8000"</span> to use the socks4a proxy
+ listening at 127.0.0.1 port 9050 to reach the HTTP proxy
+ listening at proxy.example.org port 8000. Replace
+ <span class="QUOTE">"forward-socks4a"</span> with
+ <span class="QUOTE">"forward-socks4"</span> to use a socks4
+ connection (with local DNS resolution) instead, use
+ <span class="QUOTE">"forward-socks5"</span> for socks5
+ connections (with remote DNS resolution).</p>
+ </li>
+ </ul>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>This action takes parameters similar to the <a href=
+ "config.html#FORWARDING">forward</a> directives in the
+ configuration file, but without the URL pattern. It can be used
+ as replacement, but normally it's only used in cases where
+ matching based on the request URL isn't sufficient.</p>
+
+ <div class="WARNING">
+ <table class="WARNING" border="1" width="90%">
+ <tr>
+ <td align="center"><b>Warning</b></td>
+ </tr>
+
+ <tr>
+ <td align="left">
+ <p>Please read the description for the <a href=
+ "config.html#FORWARDING">forward</a> directives before
+ using this action. Forwarding to the wrong people will
+ reduce your privacy and increase the chances of
+ man-in-the-middle attacks.</p>
+
+ <p>If the ports are missing or invalid, default values
+ will be used. This might change in the future and you
+ shouldn't rely on it. Otherwise incorrect syntax causes
+ Privoxy to exit.</p>
+
+ <p>Use the <a href=
+ "http://config.privoxy.org/show-url-info" target=
+ "_top">show-url-info CGI page</a> to verify that your
+ forward settings do what you thought the do.</p>
+ </td>
+ </tr>
+ </table>
+ </div>
+ </dd>
+
+ <dt>Example usage:</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Always use direct connections for requests previously tagged as
+# <span class="QUOTE">"User-Agent: fetch libfetch/2.0"</span> and make sure
+# resuming downloads continues to work.
+# This way you can continue to use Tor for your normal browsing,
+# without overloading the Tor network with your FreeBSD ports updates
+# or downloads of bigger files like ISOs.
+# Note that HTTP headers are easy to fake and therefore their
+# values are as (un)trustworthy as your clients and users.
+{+forward-override{forward .} \
+ -hide-if-modified-since \
+ -overwrite-last-modified \
+}
+TAG:^User-Agent: fetch libfetch/2\.0$
+
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="HANDLE-AS-EMPTY-DOCUMENT" id=
+ "HANDLE-AS-EMPTY-DOCUMENT">8.5.18. handle-as-empty-document</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Mark URLs that should be replaced by empty documents
+ <span class="emphasis"><i class="EMPHASIS">if they get
+ blocked</i></span></p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>This action alone doesn't do anything noticeable. It just
+ marks URLs. If the <tt class="LITERAL"><a href=
+ "actions-file.html#BLOCK">block</a></tt> action <span class=
+ "emphasis"><i class="EMPHASIS">also applies</i></span>, the
+ presence or absence of this mark decides whether an HTML
+ <span class="QUOTE">"BLOCKED"</span> page, or an empty document
+ will be sent to the client as a substitute for the blocked
+ content. The <span class="emphasis"><i class=
+ "EMPHASIS">empty</i></span> document isn't literally empty, but
+ actually contains a single space.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Boolean.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>N/A</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>Some browsers complain about syntax errors if JavaScript
+ documents are blocked with <span class=
+ "APPLICATION">Privoxy's</span> default HTML page; this option
+ can be used to silence them. And of course this action can also
+ be used to eliminate the <span class=
+ "APPLICATION">Privoxy</span> BLOCKED message in frames.</p>
+
+ <p>The content type for the empty document can be specified
+ with <tt class="LITERAL"><a href=
+ "actions-file.html#CONTENT-TYPE-OVERWRITE">content-type-overwrite{}</a></tt>,
+ but usually this isn't necessary.</p>
+ </dd>
+
+ <dt>Example usage:</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Block all documents on example.org that end with ".js",
+# but send an empty document instead of the usual HTML message.
+{+block{Blocked JavaScript} +handle-as-empty-document}
+example.org/.*\.js$
+
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="HANDLE-AS-IMAGE" id=
+ "HANDLE-AS-IMAGE">8.5.19. handle-as-image</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Mark URLs as belonging to images (so they'll be replaced by
+ images <span class="emphasis"><i class="EMPHASIS">if they do
+ get blocked</i></span>, rather than HTML pages)</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>This action alone doesn't do anything noticeable. It just
+ marks URLs as images. If the <tt class="LITERAL"><a href=
+ "actions-file.html#BLOCK">block</a></tt> action <span class=
+ "emphasis"><i class="EMPHASIS">also applies</i></span>, the
+ presence or absence of this mark decides whether an HTML
+ <span class="QUOTE">"blocked"</span> page, or a replacement
+ image (as determined by the <tt class="LITERAL"><a href=
+ "actions-file.html#SET-IMAGE-BLOCKER">set-image-blocker</a></tt>
+ action) will be sent to the client as a substitute for the
+ blocked content.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Boolean.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>N/A</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>The below generic example section is actually part of
+ <tt class="FILENAME">default.action</tt>. It marks all URLs
+ with well-known image file name extensions as images and should
+ be left intact.</p>
+
+ <p>Users will probably only want to use the handle-as-image
+ action in conjunction with <tt class="LITERAL"><a href=
+ "actions-file.html#BLOCK">block</a></tt>, to block sources of
+ banners, whose URLs don't reflect the file type, like in the
+ second example section.</p>
+
+ <p>Note that you cannot treat HTML pages as images in most
+ cases. For instance, (in-line) ad frames require an HTML page
+ to be sent, or they won't display properly. Forcing <tt class=
+ "LITERAL">handle-as-image</tt> in this situation will not
+ replace the ad frame with an image, but lead to error
+ messages.</p>
+ </dd>
+
+ <dt>Example usage (sections):</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Generic image extensions:
#
{+handle-as-image}
/.*\.(gif|jpg|jpeg|png|bmp|ico)$
-# These don't look like images, but they're banners and should be
-# blocked as images:
+# These don't look like images, but they're banners and should be
+# blocked as images:
+#
+{+block{Nasty banners.} +handle-as-image}
+nasty-banner-server.example.com/junk.cgi\?output=trash
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="HIDE-ACCEPT-LANGUAGE" id=
+ "HIDE-ACCEPT-LANGUAGE">8.5.20. hide-accept-language</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Pretend to use different language settings.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Deletes or replaces the <span class=
+ "QUOTE">"Accept-Language:"</span> HTTP header in client
+ requests.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>Keyword: <span class="QUOTE">"block"</span>, or any user
+ defined value.</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>Faking the browser's language settings can be useful to make
+ a foreign User-Agent set with <tt class="LITERAL"><a href=
+ "actions-file.html#HIDE-USER-AGENT">hide-user-agent</a></tt>
+ more believable.</p>
+
+ <p>However some sites with content in different languages check
+ the <span class="QUOTE">"Accept-Language:"</span> to decide
+ which one to take by default. Sometimes it isn't possible to
+ later switch to another language without changing the
+ <span class="QUOTE">"Accept-Language:"</span> header first.</p>
+
+ <p>Therefore it's a good idea to either only change the
+ <span class="QUOTE">"Accept-Language:"</span> header to
+ languages you understand, or to languages that aren't wide
+ spread.</p>
+
+ <p>Before setting the <span class=
+ "QUOTE">"Accept-Language:"</span> header to a rare language,
+ you should consider that it helps to make your requests unique
+ and thus easier to trace. If you don't plan to change this
+ header frequently, you should stick to a common language.</p>
+ </dd>
+
+ <dt>Example usage (section):</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Pretend to use Canadian language settings.
+{+hide-accept-language{en-ca} \
++hide-user-agent{Mozilla/5.0 (X11; U; OpenBSD i386; en-CA; rv:1.8.0.4) Gecko/20060628 Firefox/1.5.0.4} \
+}
+/
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="HIDE-CONTENT-DISPOSITION" id=
+ "HIDE-CONTENT-DISPOSITION">8.5.21. hide-content-disposition</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Prevent download menus for content you prefer to view inside
+ the browser.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Deletes or replaces the <span class=
+ "QUOTE">"Content-Disposition:"</span> HTTP header set by some
+ servers.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>Keyword: <span class="QUOTE">"block"</span>, or any user
+ defined value.</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>Some servers set the <span class=
+ "QUOTE">"Content-Disposition:"</span> HTTP header for documents
+ they assume you want to save locally before viewing them. The
+ <span class="QUOTE">"Content-Disposition:"</span> header
+ contains the file name the browser is supposed to use by
+ default.</p>
+
+ <p>In most browsers that understand this header, it makes it
+ impossible to <span class="emphasis"><i class="EMPHASIS">just
+ view</i></span> the document, without downloading it first,
+ even if it's just a simple text file or an image.</p>
+
+ <p>Removing the <span class=
+ "QUOTE">"Content-Disposition:"</span> header helps to prevent
+ this annoyance, but some browsers additionally check the
+ <span class="QUOTE">"Content-Type:"</span> header, before they
+ decide if they can display a document without saving it first.
+ In these cases, you have to change this header as well, before
+ the browser stops displaying download menus.</p>
+
+ <p>It is also possible to change the server's file name
+ suggestion to another one, but in most cases it isn't worth the
+ time to set it up.</p>
+
+ <p>This action will probably be removed in the future, use
+ server-header filters instead.</p>
+ </dd>
+
+ <dt>Example usage:</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Disarm the download link in Sourceforge's patch tracker
+{ -filter \
+ +content-type-overwrite{text/plain}\
+ +hide-content-disposition{block} }
+ .sourceforge.net/tracker/download\.php
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="HIDE-IF-MODIFIED-SINCE" id=
+ "HIDE-IF-MODIFIED-SINCE">8.5.22. hide-if-modified-since</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Prevent yet another way to track the user's steps between
+ sessions.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Deletes the <span class="QUOTE">"If-Modified-Since:"</span>
+ HTTP client header or modifies its value.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>Keyword: <span class="QUOTE">"block"</span>, or a user
+ defined value that specifies a range of hours.</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>Removing this header is useful for filter testing, where you
+ want to force a real reload instead of getting status code
+ <span class="QUOTE">"304"</span>, which would cause the browser
+ to use a cached copy of the page.</p>
+
+ <p>Instead of removing the header, <tt class=
+ "LITERAL">hide-if-modified-since</tt> can also add or subtract
+ a random amount of time to/from the header's value. You specify
+ a range of minutes where the random factor should be chosen
+ from and <span class="APPLICATION">Privoxy</span> does the
+ rest. A negative value means subtracting, a positive value
+ adding.</p>
+
+ <p>Randomizing the value of the <span class=
+ "QUOTE">"If-Modified-Since:"</span> makes it less likely that
+ the server can use the time as a cookie replacement, but you
+ will run into caching problems if the random range is too
+ high.</p>
+
+ <p>It is a good idea to only use a small negative value and let
+ <tt class="LITERAL"><a href=
+ "actions-file.html#OVERWRITE-LAST-MODIFIED">overwrite-last-modified</a></tt>
+ handle the greater changes.</p>
+
+ <p>It is also recommended to use this action together with
+ <tt class="LITERAL"><a href=
+ "actions-file.html#CRUNCH-IF-NONE-MATCH">crunch-if-none-match</a></tt>,
+ otherwise it's more or less pointless.</p>
+ </dd>
+
+ <dt>Example usage (section):</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Let the browser revalidate but make tracking based on the time less likely.
+{+hide-if-modified-since{-60} \
+ +overwrite-last-modified{randomize} \
+ +crunch-if-none-match}
+/
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="HIDE-FROM-HEADER" id=
+ "HIDE-FROM-HEADER">8.5.23. hide-from-header</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Keep your (old and ill) browser from telling web servers
+ your email address</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Deletes any existing <span class="QUOTE">"From:"</span> HTTP
+ header, or replaces it with the specified string.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>Keyword: <span class="QUOTE">"block"</span>, or any user
+ defined value.</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>The keyword <span class="QUOTE">"block"</span> will
+ completely remove the header (not to be confused with the
+ <tt class="LITERAL"><a href=
+ "actions-file.html#BLOCK">block</a></tt> action).</p>
+
+ <p>Alternately, you can specify any value you prefer to be sent
+ to the web server. If you do, it is a matter of fairness not to
+ use any address that is actually used by a real person.</p>
+
+ <p>This action is rarely needed, as modern web browsers don't
+ send <span class="QUOTE">"From:"</span> headers anymore.</p>
+ </dd>
+
+ <dt>Example usage:</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++hide-from-header{block}
+</pre>
+ </td>
+ </tr>
+ </table>or
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++hide-from-header{spam-me-senseless@sittingduck.example.com}
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="HIDE-REFERRER" id="HIDE-REFERRER">8.5.24.
+ hide-referrer</a></h4><a name="HIDE-REFERER" id="HIDE-REFERER"></a>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Conceal which link you followed to get to a particular
+ site</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Deletes the <span class="QUOTE">"Referer:"</span> (sic) HTTP
+ header from the client request, or replaces it with a forged
+ one.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <ul>
+ <li>
+ <p><span class="QUOTE">"conditional-block"</span> to delete
+ the header completely if the host has changed.</p>
+ </li>
+
+ <li>
+ <p><span class="QUOTE">"conditional-forge"</span> to forge
+ the header if the host has changed.</p>
+ </li>
+
+ <li>
+ <p><span class="QUOTE">"block"</span> to delete the header
+ unconditionally.</p>
+ </li>
+
+ <li>
+ <p><span class="QUOTE">"forge"</span> to pretend to be
+ coming from the homepage of the server we are talking
+ to.</p>
+ </li>
+
+ <li>
+ <p>Any other string to set a user defined referrer.</p>
+ </li>
+ </ul>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p><tt class="LITERAL">conditional-block</tt> is the only
+ parameter, that isn't easily detected in the server's log file.
+ If it blocks the referrer, the request will look like the
+ visitor used a bookmark or typed in the address directly.</p>
+
+ <p>Leaving the referrer unmodified for requests on the same
+ host allows the server owner to see the visitor's <span class=
+ "QUOTE">"click path"</span>, but in most cases she could also
+ get that information by comparing other parts of the log file:
+ for example the User-Agent if it isn't a very common one, or
+ the user's IP address if it doesn't change between different
+ requests.</p>
+
+ <p>Always blocking the referrer, or using a custom one, can
+ lead to failures on servers that check the referrer before they
+ answer any requests, in an attempt to prevent their content
+ from being embedded or linked to elsewhere.</p>
+
+ <p>Both <tt class="LITERAL">conditional-block</tt> and
+ <tt class="LITERAL">forge</tt> will work with referrer checks,
+ as long as content and valid referring page are on the same
+ host. Most of the time that's the case.</p>
+
+ <p><tt class="LITERAL">hide-referer</tt> is an alternate
+ spelling of <tt class="LITERAL">hide-referrer</tt> and the two
+ can be can be freely substituted with each other. (<span class=
+ "QUOTE">"referrer"</span> is the correct English spelling,
+ however the HTTP specification has a bug - it requires it to be
+ spelled as <span class="QUOTE">"referer"</span>.)</p>
+ </dd>
+
+ <dt>Example usage:</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++hide-referrer{forge}
+</pre>
+ </td>
+ </tr>
+ </table>or
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++hide-referrer{http://www.yahoo.com/}
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="HIDE-USER-AGENT" id=
+ "HIDE-USER-AGENT">8.5.25. hide-user-agent</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Try to conceal your type of browser and client operating
+ system</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Replaces the value of the <span class=
+ "QUOTE">"User-Agent:"</span> HTTP header in client requests
+ with the specified value.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>Any user-defined string.</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <div class="WARNING">
+ <table class="WARNING" border="1" width="90%">
+ <tr>
+ <td align="center"><b>Warning</b></td>
+ </tr>
+
+ <tr>
+ <td align="left">
+ <p>This can lead to problems on web sites that depend
+ on looking at this header in order to customize their
+ content for different browsers (which, by the way, is
+ <span class="emphasis"><i class=
+ "EMPHASIS">NOT</i></span> the right thing to do: good
+ web sites work browser-independently).</p>
+ </td>
+ </tr>
+ </table>
+ </div>
+
+ <p>Using this action in multi-user setups or wherever different
+ types of browsers will access the same <span class=
+ "APPLICATION">Privoxy</span> is <span class=
+ "emphasis"><i class="EMPHASIS">not recommended</i></span>. In
+ single-user, single-browser setups, you might use it to delete
+ your OS version information from the headers, because it is an
+ invitation to exploit known bugs for your OS. It is also
+ occasionally useful to forge this in order to access sites that
+ won't let you in otherwise (though there may be a good reason
+ in some cases).</p>
+
+ <p>More information on known user-agent strings can be found at
+ <a href="http://www.user-agents.org/" target=
+ "_top">http://www.user-agents.org/</a> and <a href=
+ "http://en.wikipedia.org/wiki/User_agent" target=
+ "_top">http://en.wikipedia.org/wiki/User_agent</a>.</p>
+ </dd>
+
+ <dt>Example usage:</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="LIMIT-CONNECT" id="LIMIT-CONNECT">8.5.26.
+ limit-connect</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Prevent abuse of <span class="APPLICATION">Privoxy</span> as
+ a TCP proxy relay or disable SSL for untrusted sites</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Specifies to which ports HTTP CONNECT requests are
+ allowable.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>A comma-separated list of ports or port ranges (the latter
+ using dashes, with the minimum defaulting to 0 and the maximum
+ to 65K).</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>By default, i.e. if no <tt class=
+ "LITERAL">limit-connect</tt> action applies, <span class=
+ "APPLICATION">Privoxy</span> allows HTTP CONNECT requests to
+ all ports. Use <tt class="LITERAL">limit-connect</tt> if
+ fine-grained control is desired for some or all
+ destinations.</p>
+
+ <p>The CONNECT methods exists in HTTP to allow access to secure
+ websites (<span class="QUOTE">"https://"</span> URLs) through
+ proxies. It works very simply: the proxy connects to the server
+ on the specified port, and then short-circuits its connections
+ to the client and to the remote server. This means
+ CONNECT-enabled proxies can be used as TCP relays very
+ easily.</p>
+
+ <p><span class="APPLICATION">Privoxy</span> relays HTTPS
+ traffic without seeing the decoded content. Websites can
+ leverage this limitation to circumvent <span class=
+ "APPLICATION">Privoxy</span>'s filters. By specifying an
+ invalid port range you can disable HTTPS entirely.</p>
+ </dd>
+
+ <dt>Example usages:</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++limit-connect{443} # Port 443 is OK.
++limit-connect{80,443} # Ports 80 and 443 are OK.
++limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
++limit-connect{-} # All ports are OK
++limit-connect{,} # No HTTPS/SSL traffic is allowed
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="LIMIT-COOKIE-LIFETIME" id=
+ "LIMIT-COOKIE-LIFETIME">8.5.27. limit-cookie-lifetime</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Limit the lifetime of HTTP cookies to a couple of minutes or
+ hours.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Overwrites the expires field in Set-Cookie server headers if
+ it's above the specified limit.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>The lifetime limit in minutes, or 0.</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>This action reduces the lifetime of HTTP cookies coming from
+ the server to the specified number of minutes, starting from
+ the time the cookie passes Privoxy.</p>
+
+ <p>Cookies with a lifetime below the limit are not modified.
+ The lifetime of session cookies is set to the specified
+ limit.</p>
+
+ <p>The effect of this action depends on the server.</p>
+
+ <p>In case of servers which refresh their cookies with each
+ response (or at least frequently), the lifetime limit set by
+ this action is updated as well. Thus, a session associated with
+ the cookie continues to work with this action enabled, as long
+ as a new request is made before the last limit set is
+ reached.</p>
+
+ <p>However, some servers send their cookies once, with a
+ lifetime of several years (the year 2037 is a popular choice),
+ and do not refresh them until a certain event in the future,
+ for example the user logging out. In this case this action may
+ limit the absolute lifetime of the session, even if requests
+ are made frequently.</p>
+
+ <p>If the parameter is <span class="QUOTE">"0"</span>, this
+ action behaves like <tt class="LITERAL"><a href=
+ "actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</a></tt>.</p>
+ </dd>
+
+ <dt>Example usages:</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++limit-cookie-lifetime{60}
+
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="PREVENT-COMPRESSION" id=
+ "PREVENT-COMPRESSION">8.5.28. prevent-compression</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Ensure that servers send the content uncompressed, so it can
+ be passed through <tt class="LITERAL"><a href=
+ "actions-file.html#FILTER">filter</a></tt>s.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Removes the Accept-Encoding header which can be used to ask
+ for compressed transfer.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Boolean.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>N/A</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>More and more websites send their content compressed by
+ default, which is generally a good idea and saves bandwidth.
+ But the <tt class="LITERAL"><a href=
+ "actions-file.html#FILTER">filter</a></tt> and <tt class=
+ "LITERAL"><a href=
+ "actions-file.html#DEANIMATE-GIFS">deanimate-gifs</a></tt>
+ actions need access to the uncompressed data.</p>
+
+ <p>When compiled with zlib support (available since
+ <span class="APPLICATION">Privoxy</span> 3.0.7), content that
+ should be filtered is decompressed on-the-fly and you don't
+ have to worry about this action. If you are using an older
+ <span class="APPLICATION">Privoxy</span> version, or one that
+ hasn't been compiled with zlib support, this action can be used
+ to convince the server to send the content uncompressed.</p>
+
+ <p>Most text-based instances compress very well, the size is
+ seldom decreased by less than 50%, for markup-heavy instances
+ like news feeds saving more than 90% of the original size isn't
+ unusual.</p>
+
+ <p>Not using compression will therefore slow down the transfer,
+ and you should only enable this action if you really need it.
+ As of <span class="APPLICATION">Privoxy</span> 3.0.7 it's
+ disabled in all predefined action settings.</p>
+
+ <p>Note that some (rare) ill-configured sites don't handle
+ requests for uncompressed documents correctly. Broken PHP
+ applications tend to send an empty document body, some IIS
+ versions only send the beginning of the content. If you enable
+ <tt class="LITERAL">prevent-compression</tt> per default, you
+ might want to add exceptions for those sites. See the example
+ for how to do that.</p>
+ </dd>
+
+ <dt>Example usage (sections):</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Selectively turn off compression, and enable a filter
#
-{+block +handle-as-image}
-some.nasty-banner-server.com/junk.cgi?output=trash
-
-# Banner source! Who cares if they also have non-image content?
-ad.doubleclick.net </PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="HIDE-FORWARDED-FOR-HEADERS"
->8.5.10. <I
-CLASS="EMPHASIS"
->hide-forwarded-for-headers</I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
->Improve privacy by hiding the true source of the request</P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> Deletes any existing <SPAN
-CLASS="QUOTE"
->"X-Forwarded-for:"</SPAN
-> HTTP header from client requests,
- and prevents adding a new one.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Boolean.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-> N/A
- </P
-></DD
-><DT
->Notes:</DT
-><DD
-><P
-> It is fairly safe to leave this on.
- </P
-><P
-> This action is scheduled for improvement: It should be able to generate forged
- <SPAN
-CLASS="QUOTE"
->"X-Forwarded-for:"</SPAN
-> headers using random IP addresses from a specified network,
- to make successive requests from the same client look like requests from a pool of different
- users sharing the same proxy.
- </P
-></DD
-><DT
->Example usage:</DT
-><DD
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+hide-forwarded-for-headers</PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="HIDE-FROM-HEADER"
->8.5.11. <I
-CLASS="EMPHASIS"
->hide-from-header</I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
->Keep your (old and ill) browser from telling web servers your email address</P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> Deletes any existing <SPAN
-CLASS="QUOTE"
->"From:"</SPAN
-> HTTP header, or replaces it with the
- specified string.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Parameterized.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-> Keyword: <SPAN
-CLASS="QUOTE"
->"block"</SPAN
->, or any user defined value.
- </P
-></DD
-><DT
->Notes:</DT
-><DD
-><P
-> The keyword <SPAN
-CLASS="QUOTE"
->"block"</SPAN
-> will completely remove the header
- (not to be confused with the <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#BLOCK"
->block</A
-></TT
->
- action).
- </P
-><P
-> Alternately, you can specify any value you prefer to be sent to the web
- server. If you do, it is a matter of fairness not to use any address that
- is actually used by a real person.
- </P
-><P
-> This action is rarely needed, as modern web browsers don't send
- <SPAN
-CLASS="QUOTE"
->"From:"</SPAN
-> headers anymore.
- </P
-></DD
-><DT
->Example usage:</DT
-><DD
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+hide-from-header{block}</PRE
-></TD
-></TR
-></TABLE
-> or
- <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+hide-from-header{spam-me-senseless@sittingduck.example.com}</PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="HIDE-REFERRER"
->8.5.12. <I
-CLASS="EMPHASIS"
->hide-referrer</I
-></A
-></H4
-><A
-NAME="HIDE-REFERER"
-></A
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
->Conceal which link you followed to get to a particular site</P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> Deletes the <SPAN
-CLASS="QUOTE"
->"Referer:"</SPAN
-> (sic) HTTP header from the client request,
- or replaces it with a forged one.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Parameterized.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-></P
-><UL
-><LI
-><P
-><SPAN
-CLASS="QUOTE"
->"block"</SPAN
-> to delete the header completely.</P
-></LI
-><LI
-><P
-><SPAN
-CLASS="QUOTE"
->"forge"</SPAN
-> to pretend to be coming from the homepage of the server we are talking to.</P
-></LI
-><LI
-><P
->Any other string to set a user defined referrer.</P
-></LI
-></UL
-></DD
-><DT
->Notes:</DT
-><DD
-><P
-> <SPAN
-CLASS="QUOTE"
->"forge"</SPAN
-> is the preferred option here, since some servers will
- not send images back otherwise, in an attempt to prevent their valuable
- content from being embedded elsewhere (and hence, without being surrounded
- by <I
-CLASS="EMPHASIS"
->their</I
-> banners).
- </P
-><P
->
- <TT
-CLASS="LITERAL"
->hide-referer</TT
-> is an alternate spelling of
- <TT
-CLASS="LITERAL"
->hide-referrer</TT
-> and the two can be can be freely
- substituted with each other. (<SPAN
-CLASS="QUOTE"
->"referrer"</SPAN
-> is the
- correct English spelling, however the HTTP specification has a bug - it
- requires it to be spelled as <SPAN
-CLASS="QUOTE"
->"referer"</SPAN
->.)
- </P
-></DD
-><DT
->Example usage:</DT
-><DD
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+hide-referrer{forge}</PRE
-></TD
-></TR
-></TABLE
-> or
- <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+hide-referrer{http://www.yahoo.com/}</PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="HIDE-USER-AGENT"
->8.5.13. <I
-CLASS="EMPHASIS"
->hide-user-agent</I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
->Conceal your type of browser and client operating system</P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> Replaces the value of the <SPAN
-CLASS="QUOTE"
->"User-Agent:"</SPAN
-> HTTP header
- in client requests with the specified value.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Parameterized.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-> Any user-defined string.
- </P
-></DD
-><DT
->Notes:</DT
-><DD
-><DIV
-CLASS="WARNING"
-><P
-></P
-><TABLE
-CLASS="WARNING"
-BORDER="1"
-WIDTH="90%"
-><TR
-><TD
-ALIGN="CENTER"
-><B
->Warning</B
-></TD
-></TR
-><TR
-><TD
-ALIGN="LEFT"
-><P
-> This breaks many web sites that depend on looking at this header in order
- to customize their content for different browsers (which, by the
- way, is <I
-CLASS="EMPHASIS"
->NOT</I
-> a <A
-HREF="http://www.javascriptkit.com/javaindex.shtml"
-TARGET="_top"
->smart way to do
- that</A
->!).
- </P
-></TD
-></TR
-></TABLE
-></DIV
-><P
-> Using this action in multi-user setups or wherever different types of
- browsers will access the same <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> is
- <I
-CLASS="EMPHASIS"
->not recommended</I
->. In single-user, single-browser
- setups, you might use it to delete your OS version information from
- the headers, because it is an invitation to exploit known bugs for your
- OS. It is also occasionally useful to forge this in order to access
- sites that won't let you in otherwise (though there may be a good
- reason in some cases). Example of this: some MSN sites will not
- let <SPAN
-CLASS="APPLICATION"
->Mozilla</SPAN
-> enter, yet forging to a
- <SPAN
-CLASS="APPLICATION"
->Netscape 6.1</SPAN
-> user-agent works just fine.
- (Must be just a silly MS goof, I'm sure :-).
- </P
-><P
-> This action is scheduled for improvement.
- </P
-></DD
-><DT
->Example usage:</DT
-><DD
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}</PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="KILL-POPUPS"
->8.5.14. <I
-CLASS="EMPHASIS"
->kill-popups<A
-NAME="KILL-POPUP"
-></A
-></I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
->Eliminate those annoying pop-up windows</P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> While loading the document, replace JavaScript code that opens
- pop-up windows with (syntactically neutral) dummy code on the fly.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Boolean.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-> N/A
- </P
-></DD
-><DT
->Notes:</DT
-><DD
-><P
-> This action is easily confused with the built-in, hardwired <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#FILTER"
->filter</A
-></TT
->
- action, but there are important differences: For <TT
-CLASS="LITERAL"
->kill-popups</TT
->,
- the document need not be buffered, so it can be incrementally rendered while
- downloading. But <TT
-CLASS="LITERAL"
->kill-popups</TT
-> doesn't catch as many pop-ups as
- <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#FILTER"
->filter</A
->{<TT
-CLASS="REPLACEABLE"
-><I
->popups</I
-></TT
->}</TT
->
- does.
- </P
-><P
-> Think of it as a fast and efficient replacement for a filter that you
- can use if you don't want any filtering at all. Note that it doesn't make
- sense to combine it with any <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#FILTER"
->filter</A
-></TT
-> action,
- since as soon as one <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#FILTER"
->filter</A
-></TT
-> applies,
- the whole document needs to be buffered anyway, which destroys the advantage of
- the <TT
-CLASS="LITERAL"
->kill-popups</TT
-> action over its filter equivalent.
- </P
-><P
-> Killing all pop-ups is a dangerous business. Many shops and banks rely on
- pop-ups to display forms, shopping carts etc, and killing only the unwanted pop-ups
- would require artificial intelligence in <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->.
- If the only kind of pop-ups that you want to kill are exit consoles (those
- <I
-CLASS="EMPHASIS"
->really nasty</I
-> windows that appear when you close an other
- one), you might want to use
- <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#FILTER"
->filter</A
->{<TT
-CLASS="REPLACEABLE"
-><I
->js-annoyances</I
-></TT
->}</TT
->
- instead.
- </P
-></DD
-><DT
->Example usage:</DT
-><DD
-><P
-><TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+kill-popups</PRE
-></TD
-></TR
-></TABLE
-></P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="LIMIT-CONNECT"
->8.5.15. <I
-CLASS="EMPHASIS"
->limit-connect</I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
->Prevent abuse of <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> as a TCP proxy relay</P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> Specifies to which ports HTTP CONNECT requests are allowable.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Parameterized.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-> A comma-separated list of ports or port ranges (the latter using dashes, with the minimum
- defaulting to 0 and the maximum to 65K).
- </P
-></DD
-><DT
->Notes:</DT
-><DD
-><P
-> By default, i.e. if no <TT
-CLASS="LITERAL"
->limit-connect</TT
-> action applies,
- <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> only allows HTTP CONNECT
- requests to port 443 (the standard, secure HTTPS port). Use
- <TT
-CLASS="LITERAL"
->limit-connect</TT
-> if more fine-grained control is desired
- for some or all destinations.
- </P
-><P
-> The CONNECT methods exists in HTTP to allow access to secure websites
- (<SPAN
-CLASS="QUOTE"
->"https://"</SPAN
-> URLs) through proxies. It works very simply:
- the proxy connects to the server on the specified port, and then
- short-circuits its connections to the client and to the remote server.
- This can be a big security hole, since CONNECT-enabled proxies can be
- abused as TCP relays very easily.
- </P
-><P
-> If you don't know what any of this means, there probably is no reason to
- change this one, since the default is already very restrictive.
- </P
-></DD
-><DT
->Example usages:</DT
-><DD
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+limit-connect{443} # This is the default and need not be specified.
-+limit-connect{80,443} # Ports 80 and 443 are OK.
-+limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
-+limit-connect{-} # All ports are OK (gaping security hole!)</PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="PREVENT-COMPRESSION"
->8.5.16. <I
-CLASS="EMPHASIS"
->prevent-compression</I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
-> Ensure that servers send the content uncompressed, so it can be
- passed through <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#FILTER"
->filter</A
-></TT
->s
- </P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> Adds a header to the request that asks for uncompressed transfer.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Boolean.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-> N/A
- </P
-></DD
-><DT
->Notes:</DT
-><DD
-><P
-> More and more websites send their content compressed by default, which
- is generally a good idea and saves bandwidth. But for the <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#FILTER"
->filter</A
-></TT
->, <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#DEANIMATE-GIFS"
->deanimate-gifs</A
-></TT
->
- and <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#KILL-POPUPS"
->kill-popups</A
-></TT
-> actions to work,
- <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> needs access to the uncompressed data.
- Unfortunately, <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> can't yet(!) uncompress, filter, and
- re-compress the content on the fly. So if you want to ensure that all websites, including
- those that normally compress, can be filtered, you need to use this action.
- </P
-><P
-> This will slow down transfers from those websites, though. If you use any of the above-mentioned
- actions, you will typically want to use <TT
-CLASS="LITERAL"
->prevent-compression</TT
-> in conjunction
- with them.
- </P
-><P
-> Note that some (rare) ill-configured sites don't handle requests for uncompressed
- documents correctly (they send an empty document body). If you use <TT
-CLASS="LITERAL"
->prevent-compression</TT
->
- per default, you'll have to add exceptions for those sites. See the example for how to do that.
- </P
-></DD
-><DT
->Example usage (sections):</DT
-><DD
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
-># Set default:
+{ +filter{tiny-textforms} +prevent-compression }
+# Match only these sites
+ .google.
+ sourceforge.net
+ sf.net
+
+# Or instead, we could set a universal default:
#
-{+prevent-compression}
-/ # Match all sites
+{ +prevent-compression }
+ / # Match all sites
-# Make exceptions for ill sites:
+# Then maybe make exceptions for broken sites:
#
-{-prevent-compression}
-www.debianhelp.org
-www.pclinuxonline.com</PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="SEND-VANILLA-WAFER"
->8.5.17. <I
-CLASS="EMPHASIS"
->send-vanilla-wafer</I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
-> Feed log analysis scripts with useless data.
- </P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> Sends a cookie with each request stating that you do not accept any copyright
- on cookies sent to you, and asking the site operator not to track you.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Boolean.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-> N/A
- </P
-></DD
-><DT
->Notes:</DT
-><DD
-><P
-> The vanilla wafer is a (relatively) unique header and could conceivably be used to track you.
- </P
-><P
-> This action is rarely used and not enabled in the default configuration.
- </P
-></DD
-><DT
->Example usage:</DT
-><DD
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+send-vanilla-wafer</PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="SEND-WAFER"
->8.5.18. <I
-CLASS="EMPHASIS"
->send-wafer</I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
-> Send custom cookies or feed log analysis scripts with even more useless data.
- </P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> Sends a custom, user-defined cookie with each request.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Multi-value.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-> A string of the form <SPAN
-CLASS="QUOTE"
->"<TT
-CLASS="REPLACEABLE"
-><I
->name</I
-></TT
->=<TT
-CLASS="REPLACEABLE"
-><I
->value</I
-></TT
->"</SPAN
->.
- </P
-></DD
-><DT
->Notes:</DT
-><DD
-><P
-> Being multi-valued, multiple instances of this action can apply to the same request,
- resulting in multiple cookies being sent.
- </P
-><P
-> This action is rarely used and not enabled in the default configuration.
- </P
-></DD
-><DT
->Example usage (section):</DT
-><DD
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->{+send-wafer{UsingPrivoxy=true}}
-my-internal-testing-server.void</PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="SESSION-COOKIES-ONLY"
->8.5.19. <I
-CLASS="EMPHASIS"
->session-cookies-only</I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
-> Allow only temporary <SPAN
-CLASS="QUOTE"
->"session"</SPAN
-> cookies (for the current browser session <I
-CLASS="EMPHASIS"
->only</I
->).
- </P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> Deletes the <SPAN
-CLASS="QUOTE"
->"expires"</SPAN
-> field from <SPAN
-CLASS="QUOTE"
->"Set-Cookie:"</SPAN
-> server headers.
- Most browsers will not store such cookies permanently and forget them in between sessions.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Boolean.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-> N/A
- </P
-></DD
-><DT
->Notes:</DT
-><DD
-><P
-> This is less strict than <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#CRUNCH-INCOMING-COOKIES"
->crunch-incoming-cookies</A
-></TT
-> /
- <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#CRUNCH-OUTGOING-COOKIES"
->crunch-outgoing-cookies</A
-></TT
-> and allows you to browse
- websites that insist or rely on setting cookies, without compromising your privacy too badly.
- </P
-><P
-> Most browsers will not permanently store cookies that have been processed by
- <TT
-CLASS="LITERAL"
->session-cookies-only</TT
-> and will forget about them between sessions.
- This makes profiling cookies useless, but won't break sites which require cookies so
- that you can log in for transactions. This is generally turned on for all
- sites, and is the recommended setting.
- </P
-><P
-> It makes <I
-CLASS="EMPHASIS"
->no sense at all</I
-> to use <TT
-CLASS="LITERAL"
->session-cookies-only</TT
->
- together with <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#CRUNCH-INCOMING-COOKIES"
->crunch-incoming-cookies</A
-></TT
-> or
- <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#CRUNCH-OUTGOING-COOKIES"
->crunch-outgoing-cookies</A
-></TT
->. If you do, cookies
- will be plainly killed.
- </P
-><P
-> Note that it is up to the browser how it handles such cookies without an <SPAN
-CLASS="QUOTE"
->"expires"</SPAN
->
- field. If you use an exotic browser, you might want to try it out to be sure.
- </P
-></DD
-><DT
->Example usage:</DT
-><DD
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+session-cookies-only</PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H4
-CLASS="SECT3"
-><A
-NAME="SET-IMAGE-BLOCKER"
->8.5.20. <I
-CLASS="EMPHASIS"
->set-image-blocker</I
-></A
-></H4
-><P
-></P
-><DIV
-CLASS="VARIABLELIST"
-><DL
-><DT
->Typical use:</DT
-><DD
-><P
->Choose the replacement for blocked images</P
-></DD
-><DT
->Effect:</DT
-><DD
-><P
-> This action alone doesn't do anything noticeable. If <I
-CLASS="EMPHASIS"
->both</I
->
- <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#BLOCK"
->block</A
-></TT
-> <I
-CLASS="EMPHASIS"
->and</I
-> <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#HANDLE-AS-IMAGE"
->handle-as-image</A
-></TT
-> <I
-CLASS="EMPHASIS"
->also</I
->
- apply, i.e. if the request is to be blocked as an image,
- <I
-CLASS="EMPHASIS"
->then</I
-> the parameter of this action decides what will be
- sent as a replacement.
- </P
-></DD
-><DT
->Type:</DT
-><DD
-><P
->Parameterized.</P
-></DD
-><DT
->Parameter:</DT
-><DD
-><P
-></P
-><UL
-><LI
-><P
-> <SPAN
-CLASS="QUOTE"
->"pattern"</SPAN
-> to send a built-in checkerboard pattern image. The image is visually
- decent, scales very well, and makes it obvious where banners were busted.
- </P
-></LI
-><LI
-><P
-> <SPAN
-CLASS="QUOTE"
->"blank"</SPAN
-> to send a built-in transparent image. This makes banners disappear
- completely, but makes it hard to detect where <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> has blocked
- images on a given page and complicates troubleshooting if <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->
- has blocked innocent images, like navigation icons.
- </P
-></LI
-><LI
-><P
-> <SPAN
-CLASS="QUOTE"
->"<TT
-CLASS="REPLACEABLE"
-><I
->target-url</I
-></TT
->"</SPAN
-> to
- send a redirect to <TT
-CLASS="REPLACEABLE"
-><I
->target-url</I
-></TT
->. You can redirect
- to any image anywhere, even in your local filesystem (via <SPAN
-CLASS="QUOTE"
->"file:///"</SPAN
-> URL).
- </P
-><P
-> A good application of redirects is to use special <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->-built-in
- URLs, which send the built-in images, as <TT
-CLASS="REPLACEABLE"
-><I
->target-url</I
-></TT
->.
- This has the same visual effect as specifying <SPAN
-CLASS="QUOTE"
->"blank"</SPAN
-> or <SPAN
-CLASS="QUOTE"
->"pattern"</SPAN
-> in
- the first place, but enables your browser to cache the replacement image, instead of requesting
- it over and over again.
- </P
-></LI
-></UL
-></DD
-><DT
->Notes:</DT
-><DD
-><P
-> The URLs for the built-in images are <SPAN
-CLASS="QUOTE"
->"http://config.privoxy.org/send-banner?type=<TT
-CLASS="REPLACEABLE"
-><I
->type</I
-></TT
->"</SPAN
->, where <TT
-CLASS="REPLACEABLE"
-><I
->type</I
-></TT
-> is
- either <SPAN
-CLASS="QUOTE"
->"blank"</SPAN
-> or <SPAN
-CLASS="QUOTE"
->"pattern"</SPAN
->.
- </P
-><P
-> There is a third (advanced) type, called <SPAN
-CLASS="QUOTE"
->"auto"</SPAN
->. It is <I
-CLASS="EMPHASIS"
->NOT</I
-> to be
- used in <TT
-CLASS="LITERAL"
->set-image-blocker</TT
->, but meant for use from <A
-HREF="filter-file.html"
->filters</A
->.
- Auto will select the type of image that would have applied to the referring page, had it been an image.
- </P
-></DD
-><DT
->Example usage:</DT
-><DD
-><P
-> Built-in pattern:
- </P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+set-image-blocker{pattern}</PRE
-></TD
-></TR
-></TABLE
->
- </P
-><P
-> Redirect to the BSD devil:
- </P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}</PRE
-></TD
-></TR
-></TABLE
->
- </P
-><P
-> Redirect to the built-in pattern for better caching:
- </P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="90%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->+set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}</PRE
-></TD
-></TR
-></TABLE
->
- </P
-></DD
-></DL
-></DIV
-></DIV
-><DIV
-CLASS="SECT3"
-><H3
-CLASS="SECT3"
-><A
-NAME="AEN2469"
->8.5.21. Summary</A
-></H3
-><P
-> Note that many of these actions have the potential to cause a page to
- misbehave, possibly even not to display at all. There are many ways
- a site designer may choose to design his site, and what HTTP header
- content, and other criteria, he may depend on. There is no way to have hard
- and fast rules for all sites. See the <A
-HREF="appendix.html#ACTIONSANAT"
->Appendix</A
-> for a brief example on troubleshooting
- actions.</P
-></DIV
-></DIV
-><DIV
-CLASS="SECT2"
-><H2
-CLASS="SECT2"
-><A
-NAME="ALIASES"
->8.6. Aliases</A
-></H2
-><P
-> Custom <SPAN
-CLASS="QUOTE"
->"actions"</SPAN
->, known to <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->
- as <SPAN
-CLASS="QUOTE"
->"aliases"</SPAN
->, can be defined by combining other actions.
- These can in turn be invoked just like the built-in actions.
- Currently, an alias name can contain any character except space, tab,
- <SPAN
-CLASS="QUOTE"
->"="</SPAN
->,
- <SPAN
-CLASS="QUOTE"
->"{"</SPAN
-> and <SPAN
-CLASS="QUOTE"
->"}"</SPAN
->, but we <I
-CLASS="EMPHASIS"
->strongly
- recommend</I
-> that you only use <SPAN
-CLASS="QUOTE"
->"a"</SPAN
-> to <SPAN
-CLASS="QUOTE"
->"z"</SPAN
->,
- <SPAN
-CLASS="QUOTE"
->"0"</SPAN
-> to <SPAN
-CLASS="QUOTE"
->"9"</SPAN
->, <SPAN
-CLASS="QUOTE"
->"+"</SPAN
->, and <SPAN
-CLASS="QUOTE"
->"-"</SPAN
->.
- Alias names are not case sensitive, and are not required to start with a
- <SPAN
-CLASS="QUOTE"
->"+"</SPAN
-> or <SPAN
-CLASS="QUOTE"
->"-"</SPAN
-> sign, since they are merely textually
- expanded.</P
-><P
-> Aliases can be used throughout the actions file, but they <I
-CLASS="EMPHASIS"
->must be
- defined in a special section at the top of the file!</I
->
- And there can only be one such section per actions file. Each actions file may
- have its own alias section, and the aliases defined in it are only visible
- within that file.</P
-><P
-> There are two main reasons to use aliases: One is to save typing for frequently
- used combinations of actions, the other one is a gain in flexibility: If you
- decide once how you want to handle shops by defining an alias called
- <SPAN
-CLASS="QUOTE"
->"shop"</SPAN
->, you can later change your policy on shops in
- <I
-CLASS="EMPHASIS"
->one</I
-> place, and your changes will take effect everywhere
- in the actions file where the <SPAN
-CLASS="QUOTE"
->"shop"</SPAN
-> alias is used. Calling aliases
- by their purpose also makes your actions files more readable.</P
-><P
-> Currently, there is one big drawback to using aliases, though:
- <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->'s built-in web-based action file
- editor honors aliases when reading the actions files, but it expands
- them before writing. So the effects of your aliases are of course preserved,
- but the aliases themselves are lost when you edit sections that use aliases
- with it.
- This is likely to change in future versions of <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->.</P
-><P
-> Now let's define some aliases...</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
-> # Useful custom aliases we can use later.
+{ -prevent-compression }
+.compusa.com/
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="OVERWRITE-LAST-MODIFIED" id=
+ "OVERWRITE-LAST-MODIFIED">8.5.29. overwrite-last-modified</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Prevent yet another way to track the user's steps between
+ sessions.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Deletes the <span class="QUOTE">"Last-Modified:"</span> HTTP
+ server header or modifies its value.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>One of the keywords: <span class="QUOTE">"block"</span>,
+ <span class="QUOTE">"reset-to-request-time"</span> and
+ <span class="QUOTE">"randomize"</span></p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>Removing the <span class="QUOTE">"Last-Modified:"</span>
+ header is useful for filter testing, where you want to force a
+ real reload instead of getting status code <span class=
+ "QUOTE">"304"</span>, which would cause the browser to reuse
+ the old version of the page.</p>
+
+ <p>The <span class="QUOTE">"randomize"</span> option overwrites
+ the value of the <span class="QUOTE">"Last-Modified:"</span>
+ header with a randomly chosen time between the original value
+ and the current time. In theory the server could send each
+ document with a different <span class=
+ "QUOTE">"Last-Modified:"</span> header to track visits without
+ using cookies. <span class="QUOTE">"Randomize"</span> makes it
+ impossible and the browser can still revalidate cached
+ documents.</p>
+
+ <p><span class="QUOTE">"reset-to-request-time"</span>
+ overwrites the value of the <span class=
+ "QUOTE">"Last-Modified:"</span> header with the current time.
+ You could use this option together with <tt class=
+ "LITERAL"><a href=
+ "actions-file.html#HIDE-IF-MODIFIED-SINCE">hide-if-modified-since</a></tt>
+ to further customize your random range.</p>
+
+ <p>The preferred parameter here is <span class=
+ "QUOTE">"randomize"</span>. It is safe to use, as long as the
+ time settings are more or less correct. If the server sets the
+ <span class="QUOTE">"Last-Modified:"</span> header to the time
+ of the request, the random range becomes zero and the value
+ stays the same. Therefore you should later randomize it a
+ second time with <tt class="LITERAL"><a href=
+ "actions-file.html#HIDE-IF-MODIFIED-SINCE">hided-if-modified-since</a></tt>,
+ just to be sure.</p>
+
+ <p>It is also recommended to use this action together with
+ <tt class="LITERAL"><a href=
+ "actions-file.html#CRUNCH-IF-NONE-MATCH">crunch-if-none-match</a></tt>.</p>
+ </dd>
+
+ <dt>Example usage:</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Let the browser revalidate without being tracked across sessions
+{ +hide-if-modified-since{-60} \
+ +overwrite-last-modified{randomize} \
+ +crunch-if-none-match}
+/
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="REDIRECT" id="REDIRECT">8.5.30.
+ redirect</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Redirect requests to other sites.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Convinces the browser that the requested document has been
+ moved to another location and the browser should get it from
+ there.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>An absolute URL or a single pcrs command.</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>Requests to which this action applies are answered with a
+ HTTP redirect to URLs of your choosing. The new URL is either
+ provided as parameter, or derived by applying a single pcrs
+ command to the original URL.</p>
+
+ <p>The syntax for pcrs commands is documented in the <a href=
+ "filter-file.html">filter file</a> section.</p>
+
+ <p>This action will be ignored if you use it together with
+ <tt class="LITERAL"><a href=
+ "actions-file.html#BLOCK">block</a></tt>. It can be combined
+ with <tt class="LITERAL"><a href=
+ "actions-file.html#FAST-REDIRECTS">fast-redirects{check-decoded-url}</a></tt>
+ to redirect to a decoded version of a rewritten URL.</p>
+
+ <p>Use this action carefully, make sure not to create
+ redirection loops and be aware that using your own redirects
+ might make it possible to fingerprint your requests.</p>
+
+ <p>In case of problems with your redirects, or simply to watch
+ them working, enable <a href="config.html#DEBUG">debug
+ 128</a>.</p>
+ </dd>
+
+ <dt>Example usages:</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Replace example.com's style sheet with another one
+{ +redirect{http://localhost/css-replacements/example.com.css} }
+ example.com/stylesheet\.css
+
+# Create a short, easy to remember nickname for a favorite site
+# (relies on the browser accept and forward invalid URLs to <span class=
+"APPLICATION">Privoxy</span>)
+{ +redirect{http://www.privoxy.org/user-manual/actions-file.html} }
+ a
+
+# Always use the expanded view for Undeadly.org articles
+# (Note the $ at the end of the URL pattern to make sure
+# the request for the rewritten URL isn't redirected as well)
+{+redirect{s@$@&mode=expanded@}}
+undeadly.org/cgi\?action=article&sid=\d*$
+
+# Redirect Google search requests to MSN
+{+redirect{s@^http://[^/]*/search\?q=([^&]*).*@http://search.msn.com/results.aspx?q=$1@}}
+.google.com/search
+
+# Redirect MSN search requests to Yahoo
+{+redirect{s@^http://[^/]*/results\.aspx\?q=([^&]*).*@http://search.yahoo.com/search?p=$1@}}
+search.msn.com//results\.aspx\?q=
+
+# Redirect remote requests for this manual
+# to the local version delivered by Privoxy
+{+redirect{s@^http://www@http://config@}}
+www.privoxy.org/user-manual/
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="SERVER-HEADER-FILTER" id=
+ "SERVER-HEADER-FILTER">8.5.31. server-header-filter</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Rewrite or remove single server headers.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>All server headers to which this action applies are filtered
+ on-the-fly through the specified regular expression based
+ substitutions.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>The name of a server-header filter, as defined in one of the
+ <a href="filter-file.html">filter files</a>.</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>Server-header filters are applied to each header on its own,
+ not to all at once. This makes it easier to diagnose problems,
+ but on the downside you can't write filters that only change
+ header x if header y's value is z. You can do that by using
+ tags though.</p>
+
+ <p>Server-header filters are executed after the other header
+ actions have finished and use their output as input.</p>
+
+ <p>Please refer to the <a href="filter-file.html">filter file
+ chapter</a> to learn which server-header filters are available
+ by default, and how to create your own.</p>
+ </dd>
+
+ <dt>Example usage (section):</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+{+server-header-filter{html-to-xml}}
+example.org/xml-instance-that-is-delivered-as-html
+
+{+server-header-filter{xml-to-html}}
+example.org/instance-that-is-delivered-as-xml-but-is-not
+
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="SERVER-HEADER-TAGGER" id=
+ "SERVER-HEADER-TAGGER">8.5.32. server-header-tagger</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Enable or disable filters based on the Content-Type
+ header.</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Server headers to which this action applies are filtered
+ on-the-fly through the specified regular expression based
+ substitutions, the result is used as tag.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>The name of a server-header tagger, as defined in one of the
+ <a href="filter-file.html">filter files</a>.</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>Server-header taggers are applied to each header on its own,
+ and as the header isn't modified, each tagger <span class=
+ "QUOTE">"sees"</span> the original.</p>
+
+ <p>Server-header taggers are executed before all other header
+ actions that modify server headers. Their tags can be used to
+ control all of the other server-header actions, the content
+ filters and the crunch actions (<a href=
+ "actions-file.html#REDIRECT">redirect</a> and <a href=
+ "actions-file.html#BLOCK">block</a>).</p>
+
+ <p>Obviously crunching based on tags created by server-header
+ taggers doesn't prevent the request from showing up in the
+ server's log file.</p>
+ </dd>
+
+ <dt>Example usage (section):</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Tag every request with the content type declared by the server
+{+server-header-tagger{content-type}}
+/
+
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="SESSION-COOKIES-ONLY" id=
+ "SESSION-COOKIES-ONLY">8.5.33. session-cookies-only</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Allow only temporary <span class="QUOTE">"session"</span>
+ cookies (for the current browser session <span class=
+ "emphasis"><i class="EMPHASIS">only</i></span>).</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>Deletes the <span class="QUOTE">"expires"</span> field from
+ <span class="QUOTE">"Set-Cookie:"</span> server headers. Most
+ browsers will not store such cookies permanently and forget
+ them in between sessions.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Boolean.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <p>N/A</p>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>This is less strict than <tt class="LITERAL"><a href=
+ "actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</a></tt>
+ / <tt class="LITERAL"><a href=
+ "actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</a></tt>
+ and allows you to browse websites that insist or rely on
+ setting cookies, without compromising your privacy too
+ badly.</p>
+
+ <p>Most browsers will not permanently store cookies that have
+ been processed by <tt class="LITERAL">session-cookies-only</tt>
+ and will forget about them between sessions. This makes
+ profiling cookies useless, but won't break sites which require
+ cookies so that you can log in for transactions. This is
+ generally turned on for all sites, and is the recommended
+ setting.</p>
+
+ <p>It makes <span class="emphasis"><i class="EMPHASIS">no sense
+ at all</i></span> to use <tt class=
+ "LITERAL">session-cookies-only</tt> together with <tt class=
+ "LITERAL"><a href=
+ "actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</a></tt>
+ or <tt class="LITERAL"><a href=
+ "actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</a></tt>.
+ If you do, cookies will be plainly killed.</p>
+
+ <p>Note that it is up to the browser how it handles such
+ cookies without an <span class="QUOTE">"expires"</span> field.
+ If you use an exotic browser, you might want to try it out to
+ be sure.</p>
+
+ <p>This setting also has no effect on cookies that may have
+ been stored previously by the browser before starting
+ <span class="APPLICATION">Privoxy</span>. These would have to
+ be removed manually.</p>
+
+ <p><span class="APPLICATION">Privoxy</span> also uses the
+ <a href=
+ "actions-file.html#FILTER-CONTENT-COOKIES">content-cookies
+ filter</a> to block some types of cookies. Content cookies are
+ not effected by <tt class=
+ "LITERAL">session-cookies-only</tt>.</p>
+ </dd>
+
+ <dt>Example usage:</dt>
+
+ <dd>
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++session-cookies-only
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h4 class="SECT3"><a name="SET-IMAGE-BLOCKER" id=
+ "SET-IMAGE-BLOCKER">8.5.34. set-image-blocker</a></h4>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt>Typical use:</dt>
+
+ <dd>
+ <p>Choose the replacement for blocked images</p>
+ </dd>
+
+ <dt>Effect:</dt>
+
+ <dd>
+ <p>This action alone doesn't do anything noticeable. If
+ <span class="emphasis"><i class="EMPHASIS">both</i></span>
+ <tt class="LITERAL"><a href=
+ "actions-file.html#BLOCK">block</a></tt> <span class=
+ "emphasis"><i class="EMPHASIS">and</i></span> <tt class=
+ "LITERAL"><a href=
+ "actions-file.html#HANDLE-AS-IMAGE">handle-as-image</a></tt>
+ <span class="emphasis"><i class="EMPHASIS">also</i></span>
+ apply, i.e. if the request is to be blocked as an image,
+ <span class="emphasis"><i class="EMPHASIS">then</i></span> the
+ parameter of this action decides what will be sent as a
+ replacement.</p>
+ </dd>
+
+ <dt>Type:</dt>
+
+ <dd>
+ <p>Parameterized.</p>
+ </dd>
+
+ <dt>Parameter:</dt>
+
+ <dd>
+ <ul>
+ <li>
+ <p><span class="QUOTE">"pattern"</span> to send a built-in
+ checkerboard pattern image. The image is visually decent,
+ scales very well, and makes it obvious where banners were
+ busted.</p>
+ </li>
+
+ <li>
+ <p><span class="QUOTE">"blank"</span> to send a built-in
+ transparent image. This makes banners disappear completely,
+ but makes it hard to detect where <span class=
+ "APPLICATION">Privoxy</span> has blocked images on a given
+ page and complicates troubleshooting if <span class=
+ "APPLICATION">Privoxy</span> has blocked innocent images,
+ like navigation icons.</p>
+ </li>
+
+ <li>
+ <p><span class="QUOTE">"<tt class=
+ "REPLACEABLE"><i>target-url</i></tt>"</span> to send a
+ redirect to <tt class="REPLACEABLE"><i>target-url</i></tt>.
+ You can redirect to any image anywhere, even in your local
+ filesystem via <span class="QUOTE">"file:///"</span> URL.
+ (But note that not all browsers support redirecting to a
+ local file system).</p>
+
+ <p>A good application of redirects is to use special
+ <span class="APPLICATION">Privoxy</span>-built-in URLs,
+ which send the built-in images, as <tt class=
+ "REPLACEABLE"><i>target-url</i></tt>. This has the same
+ visual effect as specifying <span class=
+ "QUOTE">"blank"</span> or <span class=
+ "QUOTE">"pattern"</span> in the first place, but enables
+ your browser to cache the replacement image, instead of
+ requesting it over and over again.</p>
+ </li>
+ </ul>
+ </dd>
+
+ <dt>Notes:</dt>
+
+ <dd>
+ <p>The URLs for the built-in images are <span class=
+ "QUOTE">"http://config.privoxy.org/send-banner?type=<tt class=
+ "REPLACEABLE"><i>type</i></tt>"</span>, where <tt class=
+ "REPLACEABLE"><i>type</i></tt> is either <span class=
+ "QUOTE">"blank"</span> or <span class=
+ "QUOTE">"pattern"</span>.</p>
+
+ <p>There is a third (advanced) type, called <span class=
+ "QUOTE">"auto"</span>. It is <span class="emphasis"><i class=
+ "EMPHASIS">NOT</i></span> to be used in <tt class=
+ "LITERAL">set-image-blocker</tt>, but meant for use from
+ <a href="filter-file.html">filters</a>. Auto will select the
+ type of image that would have applied to the referring page,
+ had it been an image.</p>
+ </dd>
+
+ <dt>Example usage:</dt>
+
+ <dd>
+ <p>Built-in pattern:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++set-image-blocker{pattern}
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>Redirect to the BSD daemon:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>Redirect to the built-in pattern for better caching:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="90%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
++set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}
+</pre>
+ </td>
+ </tr>
+ </table>
+ </dd>
+ </dl>
+ </div>
+ </div>
+
+ <div class="SECT3">
+ <h3 class="SECT3"><a name="AEN4743" id="AEN4743">8.5.35.
+ Summary</a></h3>
+
+ <p>Note that many of these actions have the potential to cause a page
+ to misbehave, possibly even not to display at all. There are many
+ ways a site designer may choose to design his site, and what HTTP
+ header content, and other criteria, he may depend on. There is no way
+ to have hard and fast rules for all sites. See the <a href=
+ "appendix.html#ACTIONSANAT">Appendix</a> for a brief example on
+ troubleshooting actions.</p>
+ </div>
+ </div>
+
+ <div class="SECT2">
+ <h2 class="SECT2"><a name="ALIASES" id="ALIASES">8.6. Aliases</a></h2>
+
+ <p>Custom <span class="QUOTE">"actions"</span>, known to <span class=
+ "APPLICATION">Privoxy</span> as <span class="QUOTE">"aliases"</span>,
+ can be defined by combining other actions. These can in turn be invoked
+ just like the built-in actions. Currently, an alias name can contain
+ any character except space, tab, <span class="QUOTE">"="</span>,
+ <span class="QUOTE">"{"</span> and <span class="QUOTE">"}"</span>, but
+ we <span class="emphasis"><i class="EMPHASIS">strongly
+ recommend</i></span> that you only use <span class="QUOTE">"a"</span>
+ to <span class="QUOTE">"z"</span>, <span class="QUOTE">"0"</span> to
+ <span class="QUOTE">"9"</span>, <span class="QUOTE">"+"</span>, and
+ <span class="QUOTE">"-"</span>. Alias names are not case sensitive, and
+ are not required to start with a <span class="QUOTE">"+"</span> or
+ <span class="QUOTE">"-"</span> sign, since they are merely textually
+ expanded.</p>
+
+ <p>Aliases can be used throughout the actions file, but they
+ <span class="emphasis"><i class="EMPHASIS">must be defined in a special
+ section at the top of the file!</i></span> And there can only be one
+ such section per actions file. Each actions file may have its own alias
+ section, and the aliases defined in it are only visible within that
+ file.</p>
+
+ <p>There are two main reasons to use aliases: One is to save typing for
+ frequently used combinations of actions, the other one is a gain in
+ flexibility: If you decide once how you want to handle shops by
+ defining an alias called <span class="QUOTE">"shop"</span>, you can
+ later change your policy on shops in <span class="emphasis"><i class=
+ "EMPHASIS">one</i></span> place, and your changes will take effect
+ everywhere in the actions file where the <span class=
+ "QUOTE">"shop"</span> alias is used. Calling aliases by their purpose
+ also makes your actions files more readable.</p>
+
+ <p>Currently, there is one big drawback to using aliases, though:
+ <span class="APPLICATION">Privoxy</span>'s built-in web-based action
+ file editor honors aliases when reading the actions files, but it
+ expands them before writing. So the effects of your aliases are of
+ course preserved, but the aliases themselves are lost when you edit
+ sections that use aliases with it.</p>
+
+ <p>Now let's define some aliases...</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+ # Useful custom aliases we can use later.
#
# Note the (required!) section header line and that this section
# must be at the top of the actions file!
# These aliases just save typing later:
# (Note that some already use other aliases!)
#
- +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
- -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
- block-as-image = +block +handle-as-image
- mercy-for-cookies = -crunch-all-cookies -session-cookies-only
+ +crunch-all-cookies = +<a href=
+"actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</a> +<a href="actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</a>
+ -crunch-all-cookies = -<a href=
+"actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</a> -<a href="actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</a>
+ +block-as-image = +block{Blocked image.} +handle-as-image
+ allow-all-cookies = -crunch-all-cookies -<a href=
+"actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</a> -<a href=
+"actions-file.html#FILTER-CONTENT-COOKIES">filter{content-cookies}</a>
# These aliases define combinations of actions
# that are useful for certain types of sites:
#
- fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
- shop = -crunch-all-cookies -filter{popups} -kill-popups
+ fragile = -<a href="actions-file.html#BLOCK">block</a> -<a href=
+"actions-file.html#FILTER">filter</a> -crunch-all-cookies -<a href=
+"actions-file.html#FAST-REDIRECTS">fast-redirects</a> -<a href=
+"actions-file.html#HIDE-REFERER">hide-referrer</a> -<a href=
+"actions-file.html#PREVENT-COMPRESSION">prevent-compression</a>
+
+ shop = -crunch-all-cookies -<a href=
+"actions-file.html#FILTER-ALL-POPUPS">filter{all-popups}</a>
# Short names for other aliases, for really lazy people ;-)
#
c0 = +crunch-all-cookies
- c1 = -crunch-all-cookies</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> ...and put them to use. These sections would appear in the lower part of an
- actions file and define exceptions to the default actions (as specified further
- up for the <SPAN
-CLASS="QUOTE"
->"/"</SPAN
-> pattern):</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
-> # These sites are either very complex or very keen on
+ c1 = -crunch-all-cookies
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>...and put them to use. These sections would appear in the lower
+ part of an actions file and define exceptions to the default actions
+ (as specified further up for the <span class="QUOTE">"/"</span>
+ pattern):</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+ # These sites are either very complex or very keen on
# user data and require minimal interference to work:
#
{fragile}
.office.microsoft.com
.windowsupdate.microsoft.com
- .nytimes.com
+ # Gmail is really mail.google.com, not gmail.com
+ mail.google.com
# Shopping sites:
# Allow cookies (for setting and retrieving your customer data)
- #
+ #
{shop}
.quietpc.com
.worldpay.com # for quietpc.com
- .scan.co.uk
+ mybank.example.com
# These shops require pop-ups:
#
- {shop -kill-popups -filter{popups}}
+ {-filter{all-popups} -filter{unsolicited-popups}}
.dabs.com
- .overclockers.co.uk</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> Aliases like <SPAN
-CLASS="QUOTE"
->"shop"</SPAN
-> and <SPAN
-CLASS="QUOTE"
->"fragile"</SPAN
-> are often used for
- <SPAN
-CLASS="QUOTE"
->"problem"</SPAN
-> sites that require some actions to be disabled
- in order to function properly.</P
-></DIV
-><DIV
-CLASS="SECT2"
-><H2
-CLASS="SECT2"
-><A
-NAME="ACT-EXAMPLES"
->8.7. Actions Files Tutorial</A
-></H2
-><P
-> The above chapters have shown <A
-HREF="actions-file.html"
->which actions files
- there are and how they are organized</A
->, how actions are <A
-HREF="actions-file.html#ACTIONS"
->specified</A
-> and <A
-HREF="actions-file.html#ACTIONS-APPLY"
->applied
- to URLs</A
->, how <A
-HREF="actions-file.html#AF-PATTERNS"
->patterns</A
-> work, and how to
- define and use <A
-HREF="actions-file.html#ALIASES"
->aliases</A
->. Now, let's look at an
- example <TT
-CLASS="FILENAME"
->default.action</TT
-> and <TT
-CLASS="FILENAME"
->user.action</TT
->
- file and see how all these pieces come together:</P
-><DIV
-CLASS="SECT3"
-><H3
-CLASS="SECT3"
-><A
-NAME="AEN2521"
->8.7.1. default.action</A
-></H3
-><P
->Every config file should start with a short comment stating its purpose:</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
-># Sample default.action file <developers@privoxy.org></PRE
-></TD
-></TR
-></TABLE
-></P
-><P
->Then, since this is the <TT
-CLASS="FILENAME"
->default.action</TT
-> file, the
-first section is a special section for internal use that you needn't
-change or worry about:</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->##########################################################################
+ .overclockers.co.uk
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>Aliases like <span class="QUOTE">"shop"</span> and <span class=
+ "QUOTE">"fragile"</span> are typically used for <span class=
+ "QUOTE">"problem"</span> sites that require more than one action to be
+ disabled in order to function properly.</p>
+ </div>
+
+ <div class="SECT2">
+ <h2 class="SECT2"><a name="ACT-EXAMPLES" id="ACT-EXAMPLES">8.7. Actions
+ Files Tutorial</a></h2>
+
+ <p>The above chapters have shown <a href="actions-file.html">which
+ actions files there are and how they are organized</a>, how actions are
+ <a href="actions-file.html#ACTIONS">specified</a> and <a href=
+ "actions-file.html#ACTIONS-APPLY">applied to URLs</a>, how <a href=
+ "actions-file.html#AF-PATTERNS">patterns</a> work, and how to define
+ and use <a href="actions-file.html#ALIASES">aliases</a>. Now, let's
+ look at an example <tt class="FILENAME">match-all.action</tt>,
+ <tt class="FILENAME">default.action</tt> and <tt class=
+ "FILENAME">user.action</tt> file and see how all these pieces come
+ together:</p>
+
+ <div class="SECT3">
+ <h3 class="SECT3"><a name="AEN4807" id="AEN4807">8.7.1.
+ match-all.action</a></h3>
+
+ <p>Remember <span class="emphasis"><i class="EMPHASIS">all actions
+ are disabled when matching starts</i></span>, so we have to
+ explicitly enable the ones we want.</p>
+
+ <p>While the <tt class="FILENAME">match-all.action</tt> file only
+ contains a single section, it is probably the most important one. It
+ has only one pattern, <span class="QUOTE">"<tt class=
+ "LITERAL">/</tt>"</span>, but this pattern <a href=
+ "actions-file.html#AF-PATTERNS">matches all URLs</a>. Therefore, the
+ set of actions used in this <span class="QUOTE">"default"</span>
+ section <span class="emphasis"><i class="EMPHASIS">will be applied to
+ all requests as a start</i></span>. It can be partly or wholly
+ overridden by other actions files like <tt class=
+ "FILENAME">default.action</tt> and <tt class=
+ "FILENAME">user.action</tt>, but it will still be largely responsible
+ for your overall browsing experience.</p>
+
+ <p>Again, at the start of matching, all actions are disabled, so
+ there is no need to disable any actions here. (Remember: a
+ <span class="QUOTE">"+"</span> preceding the action name enables the
+ action, a <span class="QUOTE">"-"</span> disables!). Also note how
+ this long line has been made more readable by splitting it into
+ multiple lines with line continuation.</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+{ \
+ +<a href=
+"actions-file.html#CHANGE-X-FORWARDED-FOR">change-x-forwarded-for{block}</a> \
+ +<a href="actions-file.html#HIDE-FROM-HEADER">hide-from-header{block}</a> \
+ +<a href=
+"actions-file.html#SET-IMAGE-BLOCKER">set-image-blocker{pattern}</a> \
+}
+/ # Match all URLs
+
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>The default behavior is now set.</p>
+ </div>
+
+ <div class="SECT3">
+ <h3 class="SECT3"><a name="AEN4829" id="AEN4829">8.7.2.
+ default.action</a></h3>
+
+ <p>If you aren't a developer, there's no need for you to edit the
+ <tt class="FILENAME">default.action</tt> file. It is maintained by
+ the <span class="APPLICATION">Privoxy</span> developers and if you
+ disagree with some of the sections, you should overrule them in your
+ <tt class="FILENAME">user.action</tt>.</p>
+
+ <p>Understanding the <tt class="FILENAME">default.action</tt> file
+ can help you with your <tt class="FILENAME">user.action</tt>,
+ though.</p>
+
+ <p>The first section in this file is a special section for internal
+ use that prevents older <span class="APPLICATION">Privoxy</span>
+ versions from reading the file:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+##########################################################################
# Settings -- Don't change! For internal Privoxy use ONLY.
##########################################################################
-
{{settings}}
-for-privoxy-version=3.0</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
->After that comes the (optional) alias section. We'll use the example
-section from the above <A
-HREF="actions-file.html#ALIASES"
->chapter on aliases</A
->,
-that also explains why and how aliases are used:</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->##########################################################################
+for-privoxy-version=3.0.11
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>After that comes the (optional) alias section. We'll use the
+ example section from the above <a href=
+ "actions-file.html#ALIASES">chapter on aliases</a>, that also
+ explains why and how aliases are used:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+##########################################################################
# Aliases
##########################################################################
{{alias}}
-# These aliases just save typing later:
-# (Note that some already use other aliases!)
-#
-+crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
--crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
-block-as-image = +block +handle-as-image
-mercy-for-cookies = -crunch-all-cookies -session-cookies-only
+ # These aliases just save typing later:
+ # (Note that some already use other aliases!)
+ #
+ +crunch-all-cookies = +<a href=
+"actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</a> +<a href="actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</a>
+ -crunch-all-cookies = -<a href=
+"actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</a> -<a href="actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</a>
+ +block-as-image = +block{Blocked image.} +handle-as-image
+ mercy-for-cookies = -crunch-all-cookies -<a href=
+"actions-file.html#SESSION-COOKIES-ONLY">session-cookies-only</a> -<a href=
+"actions-file.html#FILTER-CONTENT-COOKIES">filter{content-cookies}</a>
-# These aliases define combinations of actions
-# that are useful for certain types of sites:
-#
-fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
-shop = mercy-for-cookies -filter{popups} -kill-popups</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> Now come the regular sections, i.e. sets of actions, accompanied
- by URL patterns to which they apply. Remember <I
-CLASS="EMPHASIS"
->all actions
- are disabled when matching starts</I
->, so we have to explicitly
- enable the ones we want.</P
-><P
-> The first regular section is probably the most important. It has only
- one pattern, <SPAN
-CLASS="QUOTE"
->"<TT
-CLASS="LITERAL"
->/</TT
->"</SPAN
->, but this pattern
- <A
-HREF="actions-file.html#AF-PATTERNS"
->matches all URLs.</A
->. Therefore, the
- set of actions used in this <SPAN
-CLASS="QUOTE"
->"default"</SPAN
-> section <I
-CLASS="EMPHASIS"
->will
- be applied to all requests as a start</I
->. It can be partly or
- wholly overridden by later matches further down this file, or in user.action,
- but it will still be largely responsible for your overall browsing
- experience.</P
-><P
-> Again, at the start of matching, all actions are disabled, so there is
- no real need to disable any actions here, but we will do that nonetheless,
- to have a complete listing for your reference. (Remember: A <SPAN
-CLASS="QUOTE"
->"+"</SPAN
->
- preceding the action name enables the action, a <SPAN
-CLASS="QUOTE"
->"-"</SPAN
-> disables!).
- Also note how this long line has been made more readable by splitting it into
- multiple lines with line continuation.</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->##########################################################################
-# "Defaults" section:
+ # These aliases define combinations of actions
+ # that are useful for certain types of sites:
+ #
+ fragile = -<a href="actions-file.html#BLOCK">block</a> -<a href=
+"actions-file.html#FILTER">filter</a> -crunch-all-cookies -<a href=
+"actions-file.html#FAST-REDIRECTS">fast-redirects</a> -<a href=
+"actions-file.html#HIDE-REFERER">hide-referrer</a>
+ shop = -crunch-all-cookies -<a href=
+"actions-file.html#FILTER-ALL-POPUPS">filter{all-popups}</a>
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>The first of our specialized sections is concerned with
+ <span class="QUOTE">"fragile"</span> sites, i.e. sites that require
+ minimum interference, because they are either very complex or very
+ keen on tracking you (and have mechanisms in place that make them
+ unusable for people who avoid being tracked). We will simply use our
+ pre-defined <tt class="LITERAL">fragile</tt> alias instead of stating
+ the list of actions explicitly:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
##########################################################################
- { \
- -<A
-HREF="actions-file.html#ADD-HEADER"
->add-header</A
-> \
- -<A
-HREF="actions-file.html#BLOCK"
->block</A
-> \
- -<A
-HREF="actions-file.html#CRUNCH-INCOMING-COOKIES"
->crunch-incoming-cookies</A
-> \
- -<A
-HREF="actions-file.html#CRUNCH-OUTGOING-COOKIES"
->crunch-outgoing-cookies</A
-> \
- +<A
-HREF="actions-file.html#DEANIMATE-GIFS"
->deanimate-gifs</A
-> \
- -<A
-HREF="actions-file.html#DOWNGRADE-HTTP-VERSION"
->downgrade-http-version</A
-> \
- +<A
-HREF="actions-file.html#FAST-REDIRECTS"
->fast-redirects</A
-> \
- +<A
-HREF="actions-file.html#FILTER-HTML-ANNOYANCES"
->filter{html-annoyances}</A
-> \
- +<A
-HREF="actions-file.html#FILTER-JS-ANNOYANCES"
->filter{js-annoyances}</A
-> \
- -<A
-HREF="actions-file.html#FILTER-CONTENT-COOKIES"
->filter{content-cookies}</A
-> \
- +<A
-HREF="actions-file.html#FILTER-POPUPS"
->filter{popups}</A
-> \
- +<A
-HREF="actions-file.html#FILTER-WEBBUGS"
->filter{webbugs}</A
-> \
- -<A
-HREF="actions-file.html#FILTER-REFRESH-TAGS"
->filter{refresh-tags}</A
-> \
- -<A
-HREF="actions-file.html#FILTER-FUN"
->filter{fun}</A
-> \
- +<A
-HREF="actions-file.html#FILTER-NIMDA"
->filter{nimda}</A
-> \
- +<A
-HREF="actions-file.html#FILTER-BANNERS-BY-SIZE"
->filter{banners-by-size}</A
-> \
- -<A
-HREF="actions-file.html#FILTER-SHOCKWAVE-FLASH"
->filter{shockwave-flash}</A
-> \
- -<A
-HREF="actions-file.html#FILTER-CRUDE-PARENTAL"
->filter{crude-parental}</A
-> \
- -<A
-HREF="actions-file.html#HANDLE-AS-IMAGE"
->handle-as-image</A
-> \
- +<A
-HREF="actions-file.html#HIDE-FORWARDED-FOR-HEADERS"
->hide-forwarded-for-headers</A
-> \
- +<A
-HREF="actions-file.html#HIDE-FROM-HEADER"
->hide-from-header{block}</A
-> \
- +<A
-HREF="actions-file.html#HIDE-REFERER"
->hide-referrer{forge}</A
-> \
- -<A
-HREF="actions-file.html#HIDE-USER-AGENT"
->hide-user-agent</A
-> \
- -<A
-HREF="actions-file.html#KILL-POPUPS"
->kill-popups</A
-> \
- -<A
-HREF="actions-file.html#LIMIT-CONNECT"
->limit-connect</A
-> \
- +<A
-HREF="actions-file.html#PREVENT-COMPRESSION"
->prevent-compression</A
-> \
- -<A
-HREF="actions-file.html#SEND-VANILLA-WAFER"
->send-vanilla-wafer</A
-> \
- -<A
-HREF="actions-file.html#SEND-WAFER"
->send-wafer</A
-> \
- +<A
-HREF="actions-file.html#SESSION-COOKIES-ONLY"
->session-cookies-only</A
-> \
- +<A
-HREF="actions-file.html#SET-IMAGE-BLOCKER"
->set-image-blocker{pattern}</A
-> \
- }
- / # forward slash will match *all* potential URL patterns.</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> The default behavior is now set. Note that some actions, like not hiding
- the user agent, are part of a <SPAN
-CLASS="QUOTE"
->"general policy"</SPAN
-> that applies
- universally and won't get any exceptions defined later. Other choices,
- like not blocking (which is <I
-CLASS="EMPHASIS"
->understandably</I
-> the
- default!) need exceptions, i.e. we need to specify explicitly what we
- want to block in later sections.
- We will also want to make exceptions from our general pop-up-killing,
- and use our defined aliases for that.</P
-><P
-> The first of our specialized sections is concerned with <SPAN
-CLASS="QUOTE"
->"fragile"</SPAN
->
- sites, i.e. sites that require minimum interference, because they are either
- very complex or very keen on tracking you (and have mechanisms in place that
- make them unusable for people who avoid being tracked). We will simply use
- our pre-defined <TT
-CLASS="LITERAL"
->fragile</TT
-> alias instead of stating the list
- of actions explicitly:</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->##########################################################################
# Exceptions for sites that'll break under the default action set:
##########################################################################
#
{ fragile }
.office.microsoft.com # surprise, surprise!
-.windowsupdate.microsoft.com</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> Shopping sites are not as fragile, but they typically
- require cookies to log in, and pop-up windows for shopping
- carts or item details. Again, we'll use a pre-defined alias:</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
-># Shopping sites:
+.windowsupdate.microsoft.com
+mail.google.com
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>Shopping sites are not as fragile, but they typically require
+ cookies to log in, and pop-up windows for shopping carts or item
+ details. Again, we'll use a pre-defined alias:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Shopping sites:
#
{ shop }
-.quietpc.com
+.quietpc.com
.worldpay.com # for quietpc.com
.jungle.com
-.scan.co.uk</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> Then, there are sites which rely on pop-up windows (yuck!) to work.
- Since we made pop-up-killing our default above, we need to make exceptions
- now. <A
-HREF="http://www.mozilla.org/"
-TARGET="_top"
->Mozilla</A
-> users, who
- can turn on smart handling of unwanted pop-ups in their browsers, can
- safely choose
- -<TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#FILTER-POPUPS"
->filter{popups}</A
-></TT
-> (and
- -<TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#KILL-POPUPS"
->kill-popups</A
-></TT
->) above
- and hence don't need this section. Anyway, disabling an already disabled
- action doesn't hurt, so we'll define our exceptions regardless of what was
- chosen in the defaults section:</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
-># These sites require pop-ups too :(
-#
-{ -<A
-HREF="actions-file.html#KILL-POPUPS"
->kill-popups</A
-> -<A
-HREF="actions-file.html#FILTER-POPUPS"
->filter{popups}</A
-> }
-.dabs.com
-.overclockers.co.uk
-.deutsche-bank-24.de</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> The <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#FAST-REDIRECTS"
->fast-redirects</A
-></TT
->
- action, which we enabled per default above, breaks some sites. So disable
- it for popular sites where we know it misbehaves:</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->{ -<A
-HREF="actions-file.html#FAST-REDIRECTS"
->fast-redirects</A
-> }
+.scan.co.uk
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>The <tt class="LITERAL"><a href=
+ "actions-file.html#FAST-REDIRECTS">fast-redirects</a></tt> action,
+ which may have been enabled in <tt class=
+ "FILENAME">match-all.action</tt>, breaks some sites. So disable it
+ for popular sites where we know it misbehaves:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+{ -<a href="actions-file.html#FAST-REDIRECTS">fast-redirects</a> }
login.yahoo.com
edit.*.yahoo.com
.google.com
.altavista.com/.*(like|url|link):http
.altavista.com/trans.*urltext=http
-.nytimes.com</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> It is important that <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> knows which
- URLs belong to images, so that <I
-CLASS="EMPHASIS"
->if</I
-> they are to
- be blocked, a substitute image can be sent, rather than an HTML page.
- Contacting the remote site to find out is not an option, since it
- would destroy the loading time advantage of banner blocking, and it
- would feed the advertisers (in terms of money <I
-CLASS="EMPHASIS"
->and</I
->
- information). We can mark any URL as an image with the <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#HANDLE-AS-IMAGE"
->handle-as-image</A
-></TT
-> action,
- and marking all URLs that end in a known image file extension is a
- good start:</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->##########################################################################
+.nytimes.com
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>It is important that <span class="APPLICATION">Privoxy</span>
+ knows which URLs belong to images, so that <span class=
+ "emphasis"><i class="EMPHASIS">if</i></span> they are to be blocked,
+ a substitute image can be sent, rather than an HTML page. Contacting
+ the remote site to find out is not an option, since it would destroy
+ the loading time advantage of banner blocking, and it would feed the
+ advertisers information about you. We can mark any URL as an image
+ with the <tt class="LITERAL"><a href=
+ "actions-file.html#HANDLE-AS-IMAGE">handle-as-image</a></tt> action,
+ and marking all URLs that end in a known image file extension is a
+ good start:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+##########################################################################
# Images:
##########################################################################
# Define which file types will be treated as images, in case they get
# blocked further down this file:
#
-{ +<A
-HREF="actions-file.html#HANDLE-AS-IMAGE"
->handle-as-image</A
-> }
-/.*\.(gif|jpe?g|png|bmp|ico)$</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> And then there are known banner sources. They often use scripts to
- generate the banners, so it won't be visible from the URL that the
- request is for an image. Hence we block them <I
-CLASS="EMPHASIS"
->and</I
->
- mark them as images in one go, with the help of our
- <TT
-CLASS="LITERAL"
->block-as-image</TT
-> alias defined above. (We could of
- course just as well use <TT
-CLASS="LITERAL"
->+<A
-HREF="actions-file.html#BLOCK"
->block</A
->
- +<A
-HREF="actions-file.html#HANDLE-AS-IMAGE"
->handle-as-image</A
-></TT
-> here.)
- Remember that the type of the replacement image is chosen by the
- <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#SET-IMAGE-BLOCKER"
->set-image-blocker</A
-></TT
->
- action. Since all URLs have matched the default section with its
- <TT
-CLASS="LITERAL"
->+<A
-HREF="actions-file.html#SET-IMAGE-BLOCKER"
->set-image-blocker</A
->{pattern}</TT
->
- action before, it still applies and needn't be repeated:</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
-># Known ad generators:
+{ +<a href="actions-file.html#HANDLE-AS-IMAGE">handle-as-image</a> }
+/.*\.(gif|jpe?g|png|bmp|ico)$
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>And then there are known banner sources. They often use scripts to
+ generate the banners, so it won't be visible from the URL that the
+ request is for an image. Hence we block them <span class=
+ "emphasis"><i class="EMPHASIS">and</i></span> mark them as images in
+ one go, with the help of our <tt class="LITERAL">+block-as-image</tt>
+ alias defined above. (We could of course just as well use <tt class=
+ "LITERAL">+<a href="actions-file.html#BLOCK">block</a> +<a href=
+ "actions-file.html#HANDLE-AS-IMAGE">handle-as-image</a></tt> here.)
+ Remember that the type of the replacement image is chosen by the
+ <tt class="LITERAL"><a href=
+ "actions-file.html#SET-IMAGE-BLOCKER">set-image-blocker</a></tt>
+ action. Since all URLs have matched the default section with its
+ <tt class="LITERAL">+<a href=
+ "actions-file.html#SET-IMAGE-BLOCKER">set-image-blocker</a>{pattern}</tt>
+ action before, it still applies and needn't be repeated:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Known ad generators:
#
-{ block-as-image }
-ar.atwola.com
+{ +block-as-image }
+ar.atwola.com
.ad.doubleclick.net
.ad.*.doubleclick.net
.a.yimg.com/(?:(?!/i/).)*$
.a[0-9].yimg.com/(?:(?!/i/).)*$
bs*.gsanet.com
-bs*.einets.com
-.qkimg.net</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> One of the most important jobs of <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
->
- is to block banners. A huge bunch of them are already <SPAN
-CLASS="QUOTE"
->"blocked"</SPAN
->
- by the <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#FILTER"
->filter</A
->{banners-by-size}</TT
->
- action, which we enabled above, and which deletes the references to banner
- images from the pages while they are loaded, so the browser doesn't request
- them anymore, and hence they don't need to be blocked here. But this naturally
- doesn't catch all banners, and some people choose not to use filters, so we
- need a comprehensive list of patterns for banner URLs here, and apply the
- <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#BLOCK"
->block</A
-></TT
-> action to them.</P
-><P
-> First comes a bunch of generic patterns, which do most of the work, by
- matching typical domain and path name components of banners. Then comes
- a list of individual patterns for specific sites, which is omitted here
- to keep the example short:</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->##########################################################################
+.qkimg.net
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>One of the most important jobs of <span class=
+ "APPLICATION">Privoxy</span> is to block banners. Many of these can
+ be <span class="QUOTE">"blocked"</span> by the <tt class=
+ "LITERAL"><a href=
+ "actions-file.html#FILTER">filter</a>{banners-by-size}</tt> action,
+ which we enabled above, and which deletes the references to banner
+ images from the pages while they are loaded, so the browser doesn't
+ request them anymore, and hence they don't need to be blocked here.
+ But this naturally doesn't catch all banners, and some people choose
+ not to use filters, so we need a comprehensive list of patterns for
+ banner URLs here, and apply the <tt class="LITERAL"><a href=
+ "actions-file.html#BLOCK">block</a></tt> action to them.</p>
+
+ <p>First comes many generic patterns, which do most of the work, by
+ matching typical domain and path name components of banners. Then
+ comes a list of individual patterns for specific sites, which is
+ omitted here to keep the example short:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+##########################################################################
# Block these fine banners:
##########################################################################
-{ <A
-HREF="actions-file.html#BLOCK"
->+block</A
-> }
+{ <a href="actions-file.html#BLOCK">+block{Banner ads.}</a> }
# Generic patterns:
-#
+#
ad*.
.*ads.
banner?.
# Site-specific patterns (abbreviated):
#
-.hitbox.com</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> You wouldn't believe how many advertisers actually call their banner
- servers ads.<TT
-CLASS="REPLACEABLE"
-><I
->company</I
-></TT
->.com, or call the directory
- in which the banners are stored simply <SPAN
-CLASS="QUOTE"
->"banners"</SPAN
->. So the above
- generic patterns are surprisingly effective.</P
-><P
-> But being very generic, they necessarily also catch URLs that we don't want
- to block. The pattern <TT
-CLASS="LITERAL"
->.*ads.</TT
-> e.g. catches
- <SPAN
-CLASS="QUOTE"
->"nasty-<I
-CLASS="EMPHASIS"
->ads</I
->.nasty-corp.com"</SPAN
-> as intended,
- but also <SPAN
-CLASS="QUOTE"
->"downlo<I
-CLASS="EMPHASIS"
->ads</I
->.sourcefroge.net"</SPAN
-> or
- <SPAN
-CLASS="QUOTE"
->"<I
-CLASS="EMPHASIS"
->ads</I
->l.some-provider.net."</SPAN
-> So here come some
- well-known exceptions to the <TT
-CLASS="LITERAL"
->+<A
-HREF="actions-file.html#BLOCK"
->block</A
-></TT
->
- section above.</P
-><P
-> Note that these are exceptions to exceptions from the default! Consider the URL
- <SPAN
-CLASS="QUOTE"
->"downloads.sourcefroge.net"</SPAN
->: Initially, all actions are deactivated,
- so it wouldn't get blocked. Then comes the defaults section, which matches the
- URL, but just deactivates the <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#BLOCK"
->block</A
-></TT
->
- action once again. Then it matches <TT
-CLASS="LITERAL"
->.*ads.</TT
->, an exception to the
- general non-blocking policy, and suddenly
- <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#BLOCK"
->+block</A
-></TT
-> applies. And now, it'll match
- <TT
-CLASS="LITERAL"
->.*loads.</TT
->, where <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#BLOCK"
->-block</A
-></TT
->
- applies, so (unless it matches <I
-CLASS="EMPHASIS"
->again</I
-> further down) it ends up
- with no <TT
-CLASS="LITERAL"
-><A
-HREF="actions-file.html#BLOCK"
->block</A
-></TT
-> action applying.</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->##########################################################################
+.hitbox.com
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>It's quite remarkable how many advertisers actually call their
+ banner servers ads.<tt class="REPLACEABLE"><i>company</i></tt>.com,
+ or call the directory in which the banners are stored simply
+ <span class="QUOTE">"banners"</span>. So the above generic patterns
+ are surprisingly effective.</p>
+
+ <p>But being very generic, they necessarily also catch URLs that we
+ don't want to block. The pattern <tt class="LITERAL">.*ads.</tt> e.g.
+ catches <span class="QUOTE">"nasty-<span class="emphasis"><i class=
+ "EMPHASIS">ads</i></span>.nasty-corp.com"</span> as intended, but
+ also <span class="QUOTE">"downlo<span class="emphasis"><i class=
+ "EMPHASIS">ads</i></span>.sourcefroge.net"</span> or <span class=
+ "QUOTE">"<span class="emphasis"><i class=
+ "EMPHASIS">ads</i></span>l.some-provider.net."</span> So here come
+ some well-known exceptions to the <tt class="LITERAL">+<a href=
+ "actions-file.html#BLOCK">block</a></tt> section above.</p>
+
+ <p>Note that these are exceptions to exceptions from the default!
+ Consider the URL <span class=
+ "QUOTE">"downloads.sourcefroge.net"</span>: Initially, all actions
+ are deactivated, so it wouldn't get blocked. Then comes the defaults
+ section, which matches the URL, but just deactivates the <tt class=
+ "LITERAL"><a href="actions-file.html#BLOCK">block</a></tt> action
+ once again. Then it matches <tt class="LITERAL">.*ads.</tt>, an
+ exception to the general non-blocking policy, and suddenly <tt class=
+ "LITERAL"><a href="actions-file.html#BLOCK">+block</a></tt> applies.
+ And now, it'll match <tt class="LITERAL">.*loads.</tt>, where
+ <tt class="LITERAL"><a href="actions-file.html#BLOCK">-block</a></tt>
+ applies, so (unless it matches <span class="emphasis"><i class=
+ "EMPHASIS">again</i></span> further down) it ends up with no
+ <tt class="LITERAL"><a href="actions-file.html#BLOCK">block</a></tt>
+ action applying.</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+##########################################################################
# Save some innocent victims of the above generic block patterns:
##########################################################################
# By domain:
-#
-{ -<A
-HREF="actions-file.html#BLOCK"
->block</A
-> }
+#
+{ -<a href="actions-file.html#BLOCK">block</a> }
adv[io]*. # (for advogato.org and advice.*)
adsl. # (has nothing to do with ads)
+adobe. # (has nothing to do with ads either)
ad[ud]*. # (adult.* and add.*)
.edu # (universities don't host banners (yet!))
.*loads. # (downloads, uploads etc)
# Site-specific:
#
www.globalintersec.com/adv # (adv = advanced)
-www.ugu.com/sui/ugu/adv</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> Filtering source code can have nasty side effects,
- so make an exception for our friends at sourceforge.net,
- and all paths with <SPAN
-CLASS="QUOTE"
->"cvs"</SPAN
-> in them. Note that
- <TT
-CLASS="LITERAL"
->-<A
-HREF="actions-file.html#FILTER"
->filter</A
-></TT
->
- disables <I
-CLASS="EMPHASIS"
->all</I
-> filters in one fell swoop!</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
-># Don't filter code!
+www.ugu.com/sui/ugu/adv
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>Filtering source code can have nasty side effects, so make an
+ exception for our friends at sourceforge.net, and all paths with
+ <span class="QUOTE">"cvs"</span> in them. Note that <tt class=
+ "LITERAL">-<a href="actions-file.html#FILTER">filter</a></tt>
+ disables <span class="emphasis"><i class="EMPHASIS">all</i></span>
+ filters in one fell swoop!</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Don't filter code!
#
-{ -<A
-HREF="actions-file.html#FILTER"
->filter</A
-> }
-/.*cvs
-.sourceforge.net</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> The actual <TT
-CLASS="FILENAME"
->default.action</TT
-> is of course more
- comprehensive, but we hope this example made clear how it works.</P
-></DIV
-><DIV
-CLASS="SECT3"
-><H3
-CLASS="SECT3"
-><A
-NAME="AEN2675"
->8.7.2. user.action</A
-></H3
-><P
-> So far we are painting with a broad brush by setting general policies,
- which would be a reasonable starting point for many people. Now,
- you'd maybe want to be more specific and have customized rules that
- are more suitable to your personal habits and preferences. These would
- be for narrowly defined situations like your ISP or your bank, and should
- be placed in <TT
-CLASS="FILENAME"
->user.action</TT
->, which is parsed after all other
- actions files and hence has the last word, over-riding any previously
- defined actions. <TT
-CLASS="FILENAME"
->user.action</TT
-> is also a
- <I
-CLASS="EMPHASIS"
->safe</I
-> place for your personal settings, since
- <TT
-CLASS="FILENAME"
->default.action</TT
-> is actively maintained by the
- <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> developers and you'll probably want
- to install updated versions from time to time.</P
-><P
-> So let's look at a few examples of things that one might typically do in
- <TT
-CLASS="FILENAME"
->user.action</TT
->: </P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
-># My user.action file. <fred@foobar.com></PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> As <A
-HREF="actions-file.html#ALIASES"
->aliases</A
-> are local to the actions
- file that they are defined in, you can't use the ones from
- <TT
-CLASS="FILENAME"
->default.action</TT
->, unless you repeat them here:</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
-># (Re-)define aliases for this file:
+{ -<a href="actions-file.html#FILTER">filter</a> }
+/(.*/)?cvs
+bugzilla.
+developer.
+wiki.
+.sourceforge.net
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>The actual <tt class="FILENAME">default.action</tt> is of course
+ much more comprehensive, but we hope this example made clear how it
+ works.</p>
+ </div>
+
+ <div class="SECT3">
+ <h3 class="SECT3"><a name="AEN4942" id="AEN4942">8.7.3.
+ user.action</a></h3>
+
+ <p>So far we are painting with a broad brush by setting general
+ policies, which would be a reasonable starting point for many people.
+ Now, you might want to be more specific and have customized rules
+ that are more suitable to your personal habits and preferences. These
+ would be for narrowly defined situations like your ISP or your bank,
+ and should be placed in <tt class="FILENAME">user.action</tt>, which
+ is parsed after all other actions files and hence has the last word,
+ over-riding any previously defined actions. <tt class=
+ "FILENAME">user.action</tt> is also a <span class=
+ "emphasis"><i class="EMPHASIS">safe</i></span> place for your
+ personal settings, since <tt class="FILENAME">default.action</tt> is
+ actively maintained by the <span class="APPLICATION">Privoxy</span>
+ developers and you'll probably want to install updated versions from
+ time to time.</p>
+
+ <p>So let's look at a few examples of things that one might typically
+ do in <tt class="FILENAME">user.action</tt>:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# My user.action file. <fred@example.com>
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>As <a href="actions-file.html#ALIASES">aliases</a> are local to
+ the actions file that they are defined in, you can't use the ones
+ from <tt class="FILENAME">default.action</tt>, unless you repeat them
+ here:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Aliases are local to the file they are defined in.
+# (Re-)define aliases for this file:
#
{{alias}}
+#
+# These aliases just save typing later, and the alias names should
+# be self explanatory.
+#
++crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
-crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
-mercy-for-cookies = -crunch-all-cookies -session-cookies-only
-fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
-shop = mercy-for-cookies -filter{popups} -kill-popups
-allow-ads = -block -filter{banners-by-size} # (see below)</PRE
-></TD
-></TR
-></TABLE
->
- </P
-><P
-> Say you have accounts on some sites that you visit regularly, and
- you don't want to have to log in manually each time. So you'd like
- to allow persistent cookies for these sites. The
- <TT
-CLASS="LITERAL"
->mercy-for-cookies</TT
-> alias defined above does exactly
- that, i.e. it disables crunching of cookies in any direction, and
- processing of cookies to make them temporary.</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->{ mercy-for-cookies }
-sunsolve.sun.com
-slashdot.org
-.yahoo.com
-.msdn.microsoft.com
-.redhat.com</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> Your bank needs popups and is allergic to some filter, but you don't
- know which, so you disable them all:</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->{ -<A
-HREF="actions-file.html#FILTER"
->filter</A
-> -<A
-HREF="actions-file.html#KILL-POPUPS"
->kill-popups</A
-> }
-.your-home-banking-site.com</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> While browsing the web with <SPAN
-CLASS="APPLICATION"
->Privoxy</SPAN
-> you
- noticed some ads that sneaked through, but you were too lazy to
- report them through our fine and easy <A
-HREF="contact.html"
->feedback</A
->
- system, so you have added them here:</P
-><P
-> <TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->{ +<A
-HREF="actions-file.html#BLOCK"
->block</A
-> }
-www.a-popular-site.com/some/unobvious/path
-another.popular.site.net/more/junk/here/</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> Note that, assuming the banners in the above example have regular image
- extensions (most do),
- <TT
-CLASS="LITERAL"
->+<A
-HREF="actions-file.html#HANDLE-AS-IMAGE"
->handle-as-image</A
-></TT
->
- need not be specified, since all URLs ending in these extensions will
- already have been tagged as images in the relevant section of
- <TT
-CLASS="FILENAME"
->default.action</TT
-> by now.</P
-><P
-> Then you noticed that the default configuration breaks Forbes Magazine,
- but you were too lazy to find out which action is the culprit, and you
- were again too lazy to give <A
-HREF="contact.html"
->feedback</A
->, so
- you just used the <TT
-CLASS="LITERAL"
->fragile</TT
-> alias on the site, and
- -- whoa! -- it worked:</P
-><P
-><TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->{ fragile }
-.forbes.com</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> You like the <SPAN
-CLASS="QUOTE"
->"fun"</SPAN
-> text replacements in <TT
-CLASS="FILENAME"
->default.filter</TT
->,
- but it is disabled in the distributed actions file. (My colleagues on the team just
- don't have a sense of humour, that's why! ;-). So you'd like to turn it on in your private,
- update-safe config, once and for all:</P
-><P
-><TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->{ +<A
-HREF="actions-file.html#FILTER-FUN"
->filter{fun}</A
-> }
-/ # For ALL sites!</PRE
-></TD
-></TR
-></TABLE
-></P
-><P
-> Note that the above is not really a good idea: There are exceptions
- to the filters in <TT
-CLASS="FILENAME"
->default.action</TT
-> for things that
- really shouldn't be filtered, like code on CVS->Web interfaces. Since
- <TT
-CLASS="FILENAME"
->user.action</TT
-> has the last word, these exceptions
- won't be valid for the <SPAN
-CLASS="QUOTE"
->"fun"</SPAN
-> filtering specified here.</P
-><P
-> Finally, you might think about how your favourite free websites are
- funded, and find that they rely on displaying banner advertisements
- to survive. So you might want to specifically allow banners for those
- sites that you feel provide value to you:</P
-><P
-><TABLE
-BORDER="0"
-BGCOLOR="#E0E0E0"
-WIDTH="100%"
-><TR
-><TD
-><PRE
-CLASS="SCREEN"
->{ allow-ads }
-.sourceforge.net
-.slashdot.org
-.osdn.net</PRE
-></TD
-></TR
-></TABLE
-> </P
-><P
-> Note that <TT
-CLASS="LITERAL"
->allow-ads</TT
-> has been aliased to
- <TT
-CLASS="LITERAL"
->-<A
-HREF="actions-file.html#BLOCK"
->block</A
-></TT
->
- <TT
-CLASS="LITERAL"
->-<A
-HREF="actions-file.html#FILTER-BANNERS-BY-SIZE"
->filter{banners-by-size}</A
-></TT
->
- above.</P
-></DIV
-></DIV
-></DIV
-><DIV
-CLASS="NAVFOOTER"
-><HR
-ALIGN="LEFT"
-WIDTH="100%"><TABLE
-WIDTH="100%"
-BORDER="0"
-CELLPADDING="0"
-CELLSPACING="0"
-><TR
-><TD
-WIDTH="33%"
-ALIGN="left"
-VALIGN="top"
-><A
-HREF="config.html"
->Prev</A
-></TD
-><TD
-WIDTH="34%"
-ALIGN="center"
-VALIGN="top"
-><A
-HREF="index.html"
->Home</A
-></TD
-><TD
-WIDTH="33%"
-ALIGN="right"
-VALIGN="top"
-><A
-HREF="filter-file.html"
->Next</A
-></TD
-></TR
-><TR
-><TD
-WIDTH="33%"
-ALIGN="left"
-VALIGN="top"
->The Main Configuration File</TD
-><TD
-WIDTH="34%"
-ALIGN="center"
-VALIGN="top"
-> </TD
-><TD
-WIDTH="33%"
-ALIGN="right"
-VALIGN="top"
->The Filter File</TD
-></TR
-></TABLE
-></DIV
-></BODY
-></HTML
->
\ No newline at end of file
+ allow-all-cookies = -crunch-all-cookies -session-cookies-only
+ allow-popups = -filter{all-popups}
++block-as-image = +block{Blocked as image.} +handle-as-image
+-block-as-image = -block
+
+# These aliases define combinations of actions that are useful for
+# certain types of sites:
+#
+fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referrer
+shop = -crunch-all-cookies allow-popups
+
+# Allow ads for selected useful free sites:
+#
+allow-ads = -block -filter{banners-by-size} -filter{banners-by-link}
+
+# Alias for specific file types that are text, but might have conflicting
+# MIME types. We want the browser to force these to be text documents.
+handle-as-text = -<a href="actions-file.html#FILTER">filter</a> +-<a href=
+"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>
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>Say you have accounts on some sites that you visit regularly, and
+ you don't want to have to log in manually each time. So you'd like to
+ allow persistent cookies for these sites. The <tt class=
+ "LITERAL">allow-all-cookies</tt> alias defined above does exactly
+ that, i.e. it disables crunching of cookies in any direction, and the
+ processing of cookies to make them only temporary.</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+{ allow-all-cookies }
+ sourceforge.net
+ .yahoo.com
+ .msdn.microsoft.com
+ .redhat.com
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>Your bank is allergic to some filter, but you don't know which, so
+ you disable them all:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+{ -<a href="actions-file.html#FILTER">filter</a> }
+ .your-home-banking-site.com
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>Some file types you may not want to filter for various
+ reasons:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+# Technical documentation is likely to contain strings that might
+# erroneously get altered by the JavaScript-oriented filters:
+#
+.tldp.org
+/(.*/)?selfhtml/
+
+# And this stupid host sends streaming video with a wrong MIME type,
+# so that Privoxy thinks it is getting HTML and starts filtering:
+#
+stupid-server.example.com/
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>Example of a simple <a href="actions-file.html#BLOCK">block</a>
+ action. Say you've seen an ad on your favourite page on example.com
+ that you want to get rid of. You have right-clicked the image,
+ selected <span class="QUOTE">"copy image location"</span> and pasted
+ the URL below while removing the leading http://, into a <tt class=
+ "LITERAL">{ +block{} }</tt> section. Note that <tt class="LITERAL">{
+ +handle-as-image }</tt> need not be specified, since all URLs ending
+ in <tt class="LITERAL">.gif</tt> will be tagged as images by the
+ general rules as set in default.action anyway:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+{ +<a href="actions-file.html#BLOCK">block</a>{Nasty ads.} }
+ www.example.com/nasty-ads/sponsor\.gif
+ another.example.net/more/junk/here/
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>The URLs of dynamically generated banners, especially from large
+ banner farms, often don't use the well-known image file name
+ extensions, which makes it impossible for <span class=
+ "APPLICATION">Privoxy</span> to guess the file type just by looking
+ at the URL. You can use the <tt class="LITERAL">+block-as-image</tt>
+ alias defined above for these cases. Note that objects which match
+ this rule but then turn out NOT to be an image are typically rendered
+ as a <span class="QUOTE">"broken image"</span> icon by the browser.
+ Use cautiously.</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+{ +block-as-image }
+ .doubleclick.net
+ .fastclick.net
+ /Realmedia/ads/
+ ar.atwola.com/
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>Now you noticed that the default configuration breaks Forbes
+ Magazine, but you were too lazy to find out which action is the
+ culprit, and you were again too lazy to give <a href=
+ "contact.html">feedback</a>, so you just used the <tt class=
+ "LITERAL">fragile</tt> alias on the site, and -- <span class=
+ "emphasis"><i class="EMPHASIS">whoa!</i></span> -- it worked. The
+ <tt class="LITERAL">fragile</tt> aliases disables those actions that
+ are most likely to break a site. Also, good for testing purposes to
+ see if it is <span class="APPLICATION">Privoxy</span> that is causing
+ the problem or not. We later find other regular sites that misbehave,
+ and add those to our personalized list of troublemakers:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+{ fragile }
+ .forbes.com
+ webmail.example.com
+ .mybank.com
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>You like the <span class="QUOTE">"fun"</span> text replacements in
+ <tt class="FILENAME">default.filter</tt>, but it is disabled in the
+ distributed actions file. So you'd like to turn it on in your
+ private, update-safe config, once and for all:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+{ +<a href="actions-file.html#FILTER-FUN">filter{fun}</a> }
+ / # For ALL sites!
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>Note that the above is not really a good idea: There are
+ exceptions to the filters in <tt class="FILENAME">default.action</tt>
+ for things that really shouldn't be filtered, like code on
+ CVS->Web interfaces. Since <tt class="FILENAME">user.action</tt>
+ has the last word, these exceptions won't be valid for the
+ <span class="QUOTE">"fun"</span> filtering specified here.</p>
+
+ <p>You might also worry about how your favourite free websites are
+ funded, and find that they rely on displaying banner advertisements
+ to survive. So you might want to specifically allow banners for those
+ sites that you feel provide value to you:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+{ allow-ads }
+ .sourceforge.net
+ .slashdot.org
+ .osdn.net
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>Note that <tt class="LITERAL">allow-ads</tt> has been aliased to
+ <tt class="LITERAL">-<a href=
+ "actions-file.html#BLOCK">block</a></tt>, <tt class=
+ "LITERAL">-<a href=
+ "actions-file.html#FILTER-BANNERS-BY-SIZE">filter{banners-by-size}</a></tt>,
+ and <tt class="LITERAL">-<a href=
+ "actions-file.html#FILTER-BANNERS-BY-LINK">filter{banners-by-link}</a></tt>
+ above.</p>
+
+ <p>Invoke another alias here to force an over-ride of the MIME type
+ <tt class="LITERAL">application/x-sh</tt> which typically would open
+ a download type dialog. In my case, I want to look at the shell
+ script, and then I can save it should I choose to.</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+{ handle-as-text }
+ /.*\.sh$
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p><tt class="FILENAME">user.action</tt> is generally the best place
+ to define exceptions and additions to the default policies of
+ <tt class="FILENAME">default.action</tt>. Some actions are safe to
+ have their default policies set here though. So let's set a default
+ policy to have a <span class="QUOTE">"blank"</span> image as opposed
+ to the checkerboard pattern for <span class="emphasis"><i class=
+ "EMPHASIS">ALL</i></span> sites. <span class="QUOTE">"/"</span> of
+ course matches all URL paths and patterns:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+{ +<a href=
+"actions-file.html#SET-IMAGE-BLOCKER">set-image-blocker{blank}</a> }
+/ # ALL sites
+</pre>
+ </td>
+ </tr>
+ </table>
+ </div>
+ </div>
+ </div>
+
+ <div class="NAVFOOTER">
+ <hr align="left" width="100%">
+
+ <table summary="Footer navigation table" width="100%" border="0"
+ cellpadding="0" cellspacing="0">
+ <tr>
+ <td width="33%" align="left" valign="top"><a href="config.html"
+ accesskey="P">Prev</a></td>
+
+ <td width="34%" align="center" valign="top"><a href="index.html"
+ accesskey="H">Home</a></td>
+
+ <td width="33%" align="right" valign="top"><a href="filter-file.html"
+ accesskey="N">Next</a></td>
+ </tr>
+
+ <tr>
+ <td width="33%" align="left" valign="top">The Main Configuration
+ File</td>
+
+ <td width="34%" align="center" valign="top"> </td>
+
+ <td width="33%" align="right" valign="top">Filter Files</td>
+ </tr>
+ </table>
+ </div>
+</body>
+</html>
projects / privoxy.git / blobdiff