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+ <td width="10%" align="left" valign="bottom"><a href=
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+ <hr align="left" width="100%">
+ </div>
+
+ <div class="SECT1">
+ <h1 class="SECT1"><a name="FILTER-FILE" id="FILTER-FILE">9. Filter
+ Files</a></h1>
+
+ <p>On-the-fly text substitutions need to be defined in a <span class=
+ "QUOTE">"filter file"</span>. Once defined, they can then be invoked as
+ an <span class="QUOTE">"action"</span>.</p>
+
+ <p><span class="APPLICATION">Privoxy</span> supports three different
+ pcrs-based filter actions: <tt class="LITERAL"><a href=
+ "actions-file.html#FILTER">filter</a></tt> to rewrite the content that is
+ send to the client, <tt class="LITERAL"><a href=
+ "actions-file.html#CLIENT-HEADER-FILTER">client-header-filter</a></tt> to
+ rewrite headers that are send by the client, and <tt class=
+ "LITERAL"><a href=
+ "actions-file.html#SERVER-HEADER-FILTER">server-header-filter</a></tt> to
+ rewrite headers that are send by the server.</p>
+
+ <p><span class="APPLICATION">Privoxy</span> also supports two tagger
+ actions: <tt class="LITERAL"><a href=
+ "actions-file.html#CLIENT-HEADER-TAGGER">client-header-tagger</a></tt>
+ and <tt class="LITERAL"><a href=
+ "actions-file.html#SERVER-HEADER-TAGGER">server-header-tagger</a></tt>.
+ Taggers and filters use the same syntax in the filter files, the
+ difference is that taggers don't modify the text they are filtering, but
+ use a rewritten version of the filtered text as tag. The tags can then be
+ used to change the applying actions through sections with <a href=
+ "actions-file.html#TAG-PATTERN">tag-patterns</a>.</p>
+
+ <p>Finally <span class="APPLICATION">Privoxy</span> supports the
+ <tt class="LITERAL"><a href=
+ "actions-file.html#EXTERNAL-FILTER">external-filter</a></tt> action to
+ enable <tt class="LITERAL"><a href=
+ "filter-file.html#EXTERNAL-FILTER-SYNTAX">external filters</a></tt>
+ written in proper programming languages.</p>
+
+ <p>Multiple filter files can be defined through the <tt class=
+ "LITERAL"><a href="config.html#FILTERFILE">filterfile</a></tt> config
+ directive. The filters as supplied by the developers are located in
+ <tt class="FILENAME">default.filter</tt>. It is recommended that any
+ locally defined or modified filters go in a separately defined file such
+ as <tt class="FILENAME">user.filter</tt>.</p>
+
+ <p>Common tasks for content filters are to eliminate common annoyances in
+ HTML and JavaScript, such as pop-up windows, exit consoles, crippled
+ windows without navigation tools, the infamous <BLINK> tag etc, to
+ suppress images with certain width and height attributes (standard banner
+ sizes or web-bugs), or just to have fun.</p>
+
+ <p>Enabled content filters are applied to any content whose <span class=
+ "QUOTE">"Content Type"</span> header is recognised as a sign of
+ text-based content, with the exception of <tt class=
+ "LITERAL">text/plain</tt>. Use the <a href=
+ "actions-file.html#FORCE-TEXT-MODE">force-text-mode</a> action to also
+ filter other content.</p>
+
+ <p>Substitutions are made at the source level, so if you want to
+ <span class="QUOTE">"roll your own"</span> filters, you should first be
+ familiar with HTML syntax, and, of course, regular expressions.</p>
+
+ <p>Just like the <a href="actions-file.html">actions files</a>, the
+ filter file is organized in sections, which are called <span class=
+ "emphasis"><i class="EMPHASIS">filters</i></span> here. Each filter
+ consists of a heading line, that starts with one of the <span class=
+ "emphasis"><i class="EMPHASIS">keywords</i></span> <tt class=
+ "LITERAL">FILTER:</tt>, <tt class="LITERAL">CLIENT-HEADER-FILTER:</tt> or
+ <tt class="LITERAL">SERVER-HEADER-FILTER:</tt> followed by the filter's
+ <span class="emphasis"><i class="EMPHASIS">name</i></span>, and a short
+ (one line) <span class="emphasis"><i class=
+ "EMPHASIS">description</i></span> of what it does. Below that line come
+ the <span class="emphasis"><i class="EMPHASIS">jobs</i></span>, i.e.
+ lines that define the actual text substitutions. By convention, the name
+ of a filter should describe what the filter <span class=
+ "emphasis"><i class="EMPHASIS">eliminates</i></span>. The comment is used
+ in the <a href="http://config.privoxy.org/" target="_top">web-based user
+ interface</a>.</p>
+
+ <p>Once a filter called <tt class="REPLACEABLE"><i>name</i></tt> has been
+ defined in the filter file, it can be invoked by using an action of the
+ form +<tt class="LITERAL"><a href=
+ "actions-file.html#FILTER">filter</a>{<tt class=
+ "REPLACEABLE"><i>name</i></tt>}</tt> in any <a href=
+ "actions-file.html">actions file</a>.</p>
+
+ <p>Filter definitions start with a header line that contains the filter
+ type, the filter name and the filter description. A content filter header
+ line for a filter called <span class="QUOTE">"foo"</span> could look like
+ this:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
+FILTER: foo Replace all "foo" with "bar"
+</pre>
+ </td>
+ </tr>
+ </table>
+
+ <p>Below that line, and up to the next header line, come the jobs that
+ define what text replacements the filter executes. They are specified in
+ a syntax that imitates <a href="http://www.perl.org/" target=
+ "_top">Perl</a>'s <tt class="LITERAL">s///</tt> operator. If you are
+ familiar with Perl, you will find this to be quite intuitive, and may
+ want to look at the PCRS documentation for the subtle differences to Perl
+ behaviour.</p>
+
+ <p>Most notably, the non-standard option letter <tt class=
+ "LITERAL">U</tt> is supported, which turns the default to ungreedy
+ matching (add <tt class="LITERAL">?</tt> to quantifiers to turn them
+ greedy again).</p>
+
+ <p>The non-standard option letter <tt class="LITERAL">D</tt> (dynamic)
+ allows to use the variables $host, $origin (the IP address the request
+ came from), $path, $url and $listen-address (the address on which Privoxy
+ accepted the client request. Example: 127.0.0.1:8118). They will be
+ replaced with the value they refer to before the filter is executed.</p>
+
+ <p>Note that '$' is a bad choice for a delimiter in a dynamic filter as
+ you might end up with unintended variables if you use a variable name
+ directly after the delimiter. Variables will be resolved without escaping
+ anything, therefore you also have to be careful not to chose delimiters
+ that appear in the replacement text. For example '<' should be save,
+ while '?' will sooner or later cause conflicts with $url.</p>
+
+ <p>The non-standard option letter <tt class="LITERAL">T</tt> (trivial)
+ prevents parsing for backreferences in the substitute. Use it if you want
+ to include text like '$&' in your substitute without quoting.</p>
+
+ <p>If you are new to <a href=
+ "http://en.wikipedia.org/wiki/Regular_expressions" target=
+ "_top"><span class="QUOTE">"Regular Expressions"</span></a>, you might
+ want to take a look at the <a href="appendix.html#REGEX">Appendix on
+ regular expressions</a>, and see the <a href=
+ "http://perldoc.perl.org/perlre.html" target="_top">Perl manual</a> for
+ <a href="http://perldoc.perl.org/perlop.html" target="_top">the
+ <tt class="LITERAL">s///</tt> operator's syntax</a> and <a href=
+ "http://perldoc.perl.org/perlre.html" target="_top">Perl-style regular
+ expressions</a> in general. The below examples might also help to get you
+ started.</p>
+
+ <div class="SECT2">
+ <h2 class="SECT2"><a name="FILTER-FILE-TUT" id="FILTER-FILE-TUT">9.1.
+ Filter File Tutorial</a></h2>
+
+ <p>Now, let's complete our <span class="QUOTE">"foo"</span> content
+ filter. We have already defined the heading, but the jobs are still
+ missing. Since all it does is to replace <span class=
+ "QUOTE">"foo"</span> with <span class="QUOTE">"bar"</span>, there is
+ only one (trivial) job needed:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
<tr>
- <td width="10%" align="left" valign="bottom">
- <a href="actions-file.html" accesskey="P">Prev</a>
- </td>
- <td width="80%" align="center" valign="bottom">
- </td>
- <td width="10%" align="right" valign="bottom">
- <a href="templates.html" accesskey="N">Next</a>
+ <td>
+ <pre class="SCREEN">
+s/foo/bar/
+</pre>
</td>
</tr>
</table>
- <hr align="LEFT" width="100%">
- </div>
- <div class="SECT1">
- <h1 class="SECT1">
- <a name="FILTER-FILE">9. Filter Files</a>
- </h1>
- <p>
- On-the-fly text substitutions need to be defined in a <span class=
- "QUOTE">"filter file"</span>. Once defined, they can then be invoked
- as an <span class="QUOTE">"action"</span>.
- </p>
- <p>
- <span class="APPLICATION">Privoxy</span> supports three different
- pcrs-based filter actions: <tt class="LITERAL"><a href=
- "actions-file.html#FILTER">filter</a></tt> to rewrite the content
- that is send to the client, <tt class="LITERAL"><a href=
- "actions-file.html#CLIENT-HEADER-FILTER">client-header-filter</a></tt>
- to rewrite headers that are send by the client, and <tt class=
- "LITERAL"><a href=
- "actions-file.html#SERVER-HEADER-FILTER">server-header-filter</a></tt>
- to rewrite headers that are send by the server.
- </p>
- <p>
- <span class="APPLICATION">Privoxy</span> also supports two tagger
- actions: <tt class="LITERAL"><a href=
- "actions-file.html#CLIENT-HEADER-TAGGER">client-header-tagger</a></tt>
- and <tt class="LITERAL"><a href=
- "actions-file.html#SERVER-HEADER-TAGGER">server-header-tagger</a></tt>.
- Taggers and filters use the same syntax in the filter files, the
- difference is that taggers don't modify the text they are filtering,
- but use a rewritten version of the filtered text as tag. The tags can
- then be used to change the applying actions through sections with <a
- href="actions-file.html#TAG-PATTERN">tag-patterns</a>.
- </p>
- <p>
- Finally <span class="APPLICATION">Privoxy</span> supports the <tt
- class="LITERAL"><a href=
- "actions-file.html#EXTERNAL-FILTER">external-filter</a></tt> action
- to enable <tt class="LITERAL"><a href=
- "filter-file.html#EXTERNAL-FILTER-SYNTAX">external filters</a></tt>
- written in proper programming languages.
- </p>
- <p>
- Multiple filter files can be defined through the <tt class=
- "LITERAL"><a href="config.html#FILTERFILE">filterfile</a></tt> config
- directive. The filters as supplied by the developers are located in
- <tt class="FILENAME">default.filter</tt>. It is recommended that any
- locally defined or modified filters go in a separately defined file
- such as <tt class="FILENAME">user.filter</tt>.
- </p>
- <p>
- Common tasks for content filters are to eliminate common annoyances
- in HTML and JavaScript, such as pop-up windows, exit consoles,
- crippled windows without navigation tools, the infamous <BLINK>
- tag etc, to suppress images with certain width and height attributes
- (standard banner sizes or web-bugs), or just to have fun.
- </p>
- <p>
- Enabled content filters are applied to any content whose <span class=
- "QUOTE">"Content Type"</span> header is recognised as a sign of
- text-based content, with the exception of <tt class=
- "LITERAL">text/plain</tt>. Use the <a href=
- "actions-file.html#FORCE-TEXT-MODE">force-text-mode</a> action to
- also filter other content.
- </p>
- <p>
- Substitutions are made at the source level, so if you want to <span
- class="QUOTE">"roll your own"</span> filters, you should first be
- familiar with HTML syntax, and, of course, regular expressions.
- </p>
- <p>
- Just like the <a href="actions-file.html">actions files</a>, the
- filter file is organized in sections, which are called <span class=
- "emphasis"><i class="EMPHASIS">filters</i></span> here. Each filter
- consists of a heading line, that starts with one of the <span class=
- "emphasis"><i class="EMPHASIS">keywords</i></span> <tt class=
- "LITERAL">FILTER:</tt>, <tt class=
- "LITERAL">CLIENT-HEADER-FILTER:</tt> or <tt class=
- "LITERAL">SERVER-HEADER-FILTER:</tt> followed by the filter's <span
- class="emphasis"><i class="EMPHASIS">name</i></span>, and a short
- (one line) <span class="emphasis"><i class=
- "EMPHASIS">description</i></span> of what it does. Below that line
- come the <span class="emphasis"><i class="EMPHASIS">jobs</i></span>,
- i.e. lines that define the actual text substitutions. By convention,
- the name of a filter should describe what the filter <span class=
- "emphasis"><i class="EMPHASIS">eliminates</i></span>. The comment is
- used in the <a href="http://config.privoxy.org/" target=
- "_top">web-based user interface</a>.
- </p>
- <p>
- Once a filter called <tt class="REPLACEABLE"><i>name</i></tt> has
- been defined in the filter file, it can be invoked by using an action
- of the form +<tt class="LITERAL"><a href=
- "actions-file.html#FILTER">filter</a>{<tt class=
- "REPLACEABLE"><i>name</i></tt>}</tt> in any <a href=
- "actions-file.html">actions file</a>.
- </p>
- <p>
- Filter definitions start with a header line that contains the filter
- type, the filter name and the filter description. A content filter
- header line for a filter called <span class="QUOTE">"foo"</span>
- could look like this:
- </p>
- <p>
- </p>
+
+ <p>But wait! Didn't the comment say that <span class=
+ "emphasis"><i class="EMPHASIS">all</i></span> occurrences of
+ <span class="QUOTE">"foo"</span> should be replaced? Our current job
+ will only take care of the first <span class="QUOTE">"foo"</span> on
+ each page. For global substitution, we'll need to add the <tt class=
+ "LITERAL">g</tt> option:</p>
+
<table border="0" bgcolor="#E0E0E0" width="100%">
<tr>
<td>
-<pre class="SCREEN">
-FILTER: foo Replace all "foo" with "bar"
+s/foo/bar/g
</pre>
</td>
</tr>
</table>
- <p>
- Below that line, and up to the next header line, come the jobs that
- define what text replacements the filter executes. They are specified
- in a syntax that imitates <a href="http://www.perl.org/" target=
- "_top">Perl</a>'s <tt class="LITERAL">s///</tt> operator. If you are
- familiar with Perl, you will find this to be quite intuitive, and may
- want to look at the PCRS documentation for the subtle differences to
- Perl behaviour.
- </p>
- <p>
- Most notably, the non-standard option letter <tt class=
- "LITERAL">U</tt> is supported, which turns the default to ungreedy
- matching (add <tt class="LITERAL">?</tt> to quantifiers to turn them
- greedy again).
- </p>
- <p>
- The non-standard option letter <tt class="LITERAL">D</tt> (dynamic)
- allows to use the variables $host, $origin (the IP address the
- request came from), $path, $url and $listen-address (the address on
- which Privoxy accepted the client request. Example: 127.0.0.1:8118).
- They will be replaced with the value they refer to before the filter
- is executed.
- </p>
- <p>
- Note that '$' is a bad choice for a delimiter in a dynamic filter as
- you might end up with unintended variables if you use a variable name
- directly after the delimiter. Variables will be resolved without
- escaping anything, therefore you also have to be careful not to chose
- delimiters that appear in the replacement text. For example '<'
- should be save, while '?' will sooner or later cause conflicts with
- $url.
- </p>
- <p>
- The non-standard option letter <tt class="LITERAL">T</tt> (trivial)
- prevents parsing for backreferences in the substitute. Use it if you
- want to include text like '$&' in your substitute without
- quoting.
- </p>
- <p>
- If you are new to <a href=
- "http://en.wikipedia.org/wiki/Regular_expressions" target=
- "_top"><span class="QUOTE">"Regular Expressions"</span></a>, you
- might want to take a look at the <a href=
- "appendix.html#REGEX">Appendix on regular expressions</a>, and see
- the <a href="http://perldoc.perl.org/perlre.html" target="_top">Perl
- manual</a> for <a href="http://perldoc.perl.org/perlop.html" target=
- "_top">the <tt class="LITERAL">s///</tt> operator's syntax</a> and <a
- href="http://perldoc.perl.org/perlre.html" target="_top">Perl-style
- regular expressions</a> in general. The below examples might also
- help to get you started.
- </p>
- <div class="SECT2">
- <h2 class="SECT2">
- <a name="FILTER-FILE-TUT">9.1. Filter File Tutorial</a>
- </h2>
- <p>
- Now, let's complete our <span class="QUOTE">"foo"</span> content
- filter. We have already defined the heading, but the jobs are still
- missing. Since all it does is to replace <span class=
- "QUOTE">"foo"</span> with <span class="QUOTE">"bar"</span>, there
- is only one (trivial) job needed:
- </p>
- <p>
- </p>
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
-<pre class="SCREEN">
-s/foo/bar/
-</pre>
- </td>
- </tr>
- </table>
-
- <p>
- But wait! Didn't the comment say that <span class="emphasis"><i
- class="EMPHASIS">all</i></span> occurrences of <span class=
- "QUOTE">"foo"</span> should be replaced? Our current job will only
- take care of the first <span class="QUOTE">"foo"</span> on each
- page. For global substitution, we'll need to add the <tt class=
- "LITERAL">g</tt> option:
- </p>
- <p>
- </p>
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
-<pre class="SCREEN">
-s/foo/bar/g
-</pre>
- </td>
- </tr>
- </table>
+ <p>Our complete filter now looks like this:</p>
- <p>
- Our complete filter now looks like this:
- </p>
- <p>
- </p>
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
-<pre class="SCREEN">
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
FILTER: foo Replace all "foo" with "bar"
s/foo/bar/g
</pre>
- </td>
- </tr>
- </table>
+ </td>
+ </tr>
+ </table>
- <p>
- Let's look at some real filters for more interesting examples. Here
- you see a filter that protects against some common annoyances that
- arise from JavaScript abuse. Let's look at its jobs one after the
- other:
- </p>
- <p>
- </p>
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
-<pre class="SCREEN">
+ <p>Let's look at some real filters for more interesting examples. Here
+ you see a filter that protects against some common annoyances that
+ arise from JavaScript abuse. Let's look at its jobs one after the
+ other:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse
# Get rid of JavaScript referrer tracking. Test page: http://www.randomoddness.com/untitled.htm
#
s|(<script.*)document\.referrer(.*</script>)|$1"Not Your Business!"$2|Usg
</pre>
- </td>
- </tr>
- </table>
+ </td>
+ </tr>
+ </table>
- <p>
- Following the header line and a comment, you see the job. Note that
- it uses <tt class="LITERAL">|</tt> as the delimiter instead of <tt
- class="LITERAL">/</tt>, because the pattern contains a forward
- slash, which would otherwise have to be escaped by a backslash (<tt
- class="LITERAL">\</tt>).
- </p>
- <p>
- Now, let's examine the pattern: it starts with the text <tt class=
- "LITERAL"><script.*</tt> enclosed in parentheses. Since the dot
- matches any character, and <tt class="LITERAL">*</tt> means: <span
- class="QUOTE">"Match an arbitrary number of the element left of
- myself"</span>, this matches <span class=
- "QUOTE">"<script"</span>, followed by <span class="emphasis"><i
- class="EMPHASIS">any</i></span> text, i.e. it matches the whole
- page, from the start of the first <script> tag.
- </p>
- <p>
- That's more than we want, but the pattern continues: <tt class=
- "LITERAL">document\.referrer</tt> matches only the exact string
- <span class="QUOTE">"document.referrer"</span>. The dot needed to
- be <span class="emphasis"><i class="EMPHASIS">escaped</i></span>,
- i.e. preceded by a backslash, to take away its special meaning as a
- joker, and make it just a regular dot. So far, the meaning is:
- Match from the start of the first <script> tag in a the page,
- up to, and including, the text <span class=
- "QUOTE">"document.referrer"</span>, if <span class="emphasis"><i
- class="EMPHASIS">both</i></span> are present in the page (and
- appear in that order).
- </p>
- <p>
- But there's still more pattern to go. The next element, again
- enclosed in parentheses, is <tt class=
- "LITERAL">.*</script></tt>. You already know what <tt class=
- "LITERAL">.*</tt> means, so the whole pattern translates to: Match
- from the start of the first <script> tag in a page to the end
- of the last <script> tag, provided that the text <span class=
- "QUOTE">"document.referrer"</span> appears somewhere in between.
- </p>
- <p>
- This is still not the whole story, since we have ignored the
- options and the parentheses: The portions of the page matched by
- sub-patterns that are enclosed in parentheses, will be remembered
- and be available through the variables <tt class="LITERAL">$1, $2,
- ...</tt> in the substitute. The <tt class="LITERAL">U</tt> option
- switches to ungreedy matching, which means that the first <tt
- class="LITERAL">.*</tt> in the pattern will only <span class=
- "QUOTE">"eat up"</span> all text in between <span class=
- "QUOTE">"<script"</span> and the <span class="emphasis"><i
- class="EMPHASIS">first</i></span> occurrence of <span class=
- "QUOTE">"document.referrer"</span>, and that the second <tt class=
- "LITERAL">.*</tt> will only span the text up to the <span class=
- "emphasis"><i class="EMPHASIS">first</i></span> <span class=
- "QUOTE">"</script>"</span> tag. Furthermore, the <tt class=
- "LITERAL">s</tt> option says that the match may span multiple lines
- in the page, and the <tt class="LITERAL">g</tt> option again means
- that the substitution is global.
- </p>
- <p>
- So, to summarize, the pattern means: Match all scripts that contain
- the text <span class="QUOTE">"document.referrer"</span>. Remember
- the parts of the script from (and including) the start tag up to
- (and excluding) the string <span class=
- "QUOTE">"document.referrer"</span> as <tt class="LITERAL">$1</tt>,
- and the part following that string, up to and including the closing
- tag, as <tt class="LITERAL">$2</tt>.
- </p>
- <p>
- Now the pattern is deciphered, but wasn't this about substituting
- things? So lets look at the substitute: <tt class="LITERAL">$1"Not
- Your Business!"$2</tt> is easy to read: The text remembered as <tt
- class="LITERAL">$1</tt>, followed by <tt class="LITERAL">"Not Your
- Business!"</tt> (<span class="emphasis"><i class=
- "EMPHASIS">including</i></span> the quotation marks!), followed by
- the text remembered as <tt class="LITERAL">$2</tt>. This produces
- an exact copy of the original string, with the middle part (the
- <span class="QUOTE">"document.referrer"</span>) replaced by <tt
- class="LITERAL">"Not Your Business!"</tt>.
- </p>
- <p>
- The whole job now reads: Replace <span class=
- "QUOTE">"document.referrer"</span> by <tt class="LITERAL">"Not Your
- Business!"</tt> wherever it appears inside a <script> tag.
- Note that this job won't break JavaScript syntax, since both the
- original and the replacement are syntactically valid string
- objects. The script just won't have access to the referrer
- information anymore.
- </p>
- <p>
- We'll show you two other jobs from the JavaScript taming
- department, but this time only point out the constructs of special
- interest:
- </p>
- <p>
- </p>
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
-<pre class="SCREEN">
+ <p>Following the header line and a comment, you see the job. Note that
+ it uses <tt class="LITERAL">|</tt> as the delimiter instead of
+ <tt class="LITERAL">/</tt>, because the pattern contains a forward
+ slash, which would otherwise have to be escaped by a backslash
+ (<tt class="LITERAL">\</tt>).</p>
+
+ <p>Now, let's examine the pattern: it starts with the text <tt class=
+ "LITERAL"><script.*</tt> enclosed in parentheses. Since the dot
+ matches any character, and <tt class="LITERAL">*</tt> means:
+ <span class="QUOTE">"Match an arbitrary number of the element left of
+ myself"</span>, this matches <span class="QUOTE">"<script"</span>,
+ followed by <span class="emphasis"><i class="EMPHASIS">any</i></span>
+ text, i.e. it matches the whole page, from the start of the first
+ <script> tag.</p>
+
+ <p>That's more than we want, but the pattern continues: <tt class=
+ "LITERAL">document\.referrer</tt> matches only the exact string
+ <span class="QUOTE">"document.referrer"</span>. The dot needed to be
+ <span class="emphasis"><i class="EMPHASIS">escaped</i></span>, i.e.
+ preceded by a backslash, to take away its special meaning as a joker,
+ and make it just a regular dot. So far, the meaning is: Match from the
+ start of the first <script> tag in a the page, up to, and
+ including, the text <span class="QUOTE">"document.referrer"</span>, if
+ <span class="emphasis"><i class="EMPHASIS">both</i></span> are present
+ in the page (and appear in that order).</p>
+
+ <p>But there's still more pattern to go. The next element, again
+ enclosed in parentheses, is <tt class="LITERAL">.*</script></tt>.
+ You already know what <tt class="LITERAL">.*</tt> means, so the whole
+ pattern translates to: Match from the start of the first <script>
+ tag in a page to the end of the last <script> tag, provided that
+ the text <span class="QUOTE">"document.referrer"</span> appears
+ somewhere in between.</p>
+
+ <p>This is still not the whole story, since we have ignored the options
+ and the parentheses: The portions of the page matched by sub-patterns
+ that are enclosed in parentheses, will be remembered and be available
+ through the variables <tt class="LITERAL">$1, $2, ...</tt> in the
+ substitute. The <tt class="LITERAL">U</tt> option switches to ungreedy
+ matching, which means that the first <tt class="LITERAL">.*</tt> in the
+ pattern will only <span class="QUOTE">"eat up"</span> all text in
+ between <span class="QUOTE">"<script"</span> and the <span class=
+ "emphasis"><i class="EMPHASIS">first</i></span> occurrence of
+ <span class="QUOTE">"document.referrer"</span>, and that the second
+ <tt class="LITERAL">.*</tt> will only span the text up to the
+ <span class="emphasis"><i class="EMPHASIS">first</i></span>
+ <span class="QUOTE">"</script>"</span> tag. Furthermore, the
+ <tt class="LITERAL">s</tt> option says that the match may span multiple
+ lines in the page, and the <tt class="LITERAL">g</tt> option again
+ means that the substitution is global.</p>
+
+ <p>So, to summarize, the pattern means: Match all scripts that contain
+ the text <span class="QUOTE">"document.referrer"</span>. Remember the
+ parts of the script from (and including) the start tag up to (and
+ excluding) the string <span class="QUOTE">"document.referrer"</span> as
+ <tt class="LITERAL">$1</tt>, and the part following that string, up to
+ and including the closing tag, as <tt class="LITERAL">$2</tt>.</p>
+
+ <p>Now the pattern is deciphered, but wasn't this about substituting
+ things? So lets look at the substitute: <tt class="LITERAL">$1"Not Your
+ Business!"$2</tt> is easy to read: The text remembered as <tt class=
+ "LITERAL">$1</tt>, followed by <tt class="LITERAL">"Not Your
+ Business!"</tt> (<span class="emphasis"><i class=
+ "EMPHASIS">including</i></span> the quotation marks!), followed by the
+ text remembered as <tt class="LITERAL">$2</tt>. This produces an exact
+ copy of the original string, with the middle part (the <span class=
+ "QUOTE">"document.referrer"</span>) replaced by <tt class=
+ "LITERAL">"Not Your Business!"</tt>.</p>
+
+ <p>The whole job now reads: Replace <span class=
+ "QUOTE">"document.referrer"</span> by <tt class="LITERAL">"Not Your
+ Business!"</tt> wherever it appears inside a <script> tag. Note
+ that this job won't break JavaScript syntax, since both the original
+ and the replacement are syntactically valid string objects. The script
+ just won't have access to the referrer information anymore.</p>
+
+ <p>We'll show you two other jobs from the JavaScript taming department,
+ but this time only point out the constructs of special interest:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
# The status bar is for displaying link targets, not pointless blahblah
#
s/window\.status\s*=\s*(['"]).*?\1/dUmMy=1/ig
</pre>
- </td>
- </tr>
- </table>
+ </td>
+ </tr>
+ </table>
- <p>
- <tt class="LITERAL">\s</tt> stands for whitespace characters
- (space, tab, newline, carriage return, form feed), so that <tt
- class="LITERAL">\s*</tt> means: <span class="QUOTE">"zero or more
- whitespace"</span>. The <tt class="LITERAL">?</tt> in <tt class=
- "LITERAL">.*?</tt> makes this matching of arbitrary text ungreedy.
- (Note that the <tt class="LITERAL">U</tt> option is not set). The
- <tt class="LITERAL">['"]</tt> construct means: <span class=
- "QUOTE">"a single <span class="emphasis"><i class=
- "EMPHASIS">or</i></span> a double quote"</span>. Finally, <tt
- class="LITERAL">\1</tt> is a back-reference to the first
- parenthesis just like <tt class="LITERAL">$1</tt> above, with the
- difference that in the <span class="emphasis"><i class=
- "EMPHASIS">pattern</i></span>, a backslash indicates a
- back-reference, whereas in the <span class="emphasis"><i class=
- "EMPHASIS">substitute</i></span>, it's the dollar.
- </p>
- <p>
- So what does this job do? It replaces assignments of single- or
- double-quoted strings to the <span class=
- "QUOTE">"window.status"</span> object with a dummy assignment
- (using a variable name that is hopefully odd enough not to conflict
- with real variables in scripts). Thus, it catches many cases where
- e.g. pointless descriptions are displayed in the status bar instead
- of the link target when you move your mouse over links.
- </p>
- <p>
- </p>
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
-<pre class="SCREEN">
+ <p><tt class="LITERAL">\s</tt> stands for whitespace characters (space,
+ tab, newline, carriage return, form feed), so that <tt class=
+ "LITERAL">\s*</tt> means: <span class="QUOTE">"zero or more
+ whitespace"</span>. The <tt class="LITERAL">?</tt> in <tt class=
+ "LITERAL">.*?</tt> makes this matching of arbitrary text ungreedy.
+ (Note that the <tt class="LITERAL">U</tt> option is not set). The
+ <tt class="LITERAL">['"]</tt> construct means: <span class="QUOTE">"a
+ single <span class="emphasis"><i class="EMPHASIS">or</i></span> a
+ double quote"</span>. Finally, <tt class="LITERAL">\1</tt> is a
+ back-reference to the first parenthesis just like <tt class=
+ "LITERAL">$1</tt> above, with the difference that in the <span class=
+ "emphasis"><i class="EMPHASIS">pattern</i></span>, a backslash
+ indicates a back-reference, whereas in the <span class=
+ "emphasis"><i class="EMPHASIS">substitute</i></span>, it's the
+ dollar.</p>
+
+ <p>So what does this job do? It replaces assignments of single- or
+ double-quoted strings to the <span class="QUOTE">"window.status"</span>
+ object with a dummy assignment (using a variable name that is hopefully
+ odd enough not to conflict with real variables in scripts). Thus, it
+ catches many cases where e.g. pointless descriptions are displayed in
+ the status bar instead of the link target when you move your mouse over
+ links.</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
# Kill OnUnload popups. Yummy. Test: http://www.zdnet.com/zdsubs/yahoo/tree/yfs.html
#
s/(<body [^>]*)onunload(.*>)/$1never$2/iU
</pre>
- </td>
- </tr>
- </table>
+ </td>
+ </tr>
+ </table>
- <p>
- Including the <a href=
- "http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-htmlevents"
- target="_top">OnUnload event binding</a> in the HTML DOM was a
- <span class="emphasis"><i class="EMPHASIS">CRIME</i></span>. When I
- close a browser window, I want it to close and die. Basta. This job
- replaces the <span class="QUOTE">"onunload"</span> attribute in
- <span class="QUOTE">"<body>"</span> tags with the dummy word
- <tt class="LITERAL">never</tt>. Note that the <tt class=
- "LITERAL">i</tt> option makes the pattern matching
- case-insensitive. Also note that ungreedy matching alone doesn't
- always guarantee a minimal match: In the first parenthesis, we had
- to use <tt class="LITERAL">[^>]*</tt> instead of <tt class=
- "LITERAL">.*</tt> to prevent the match from exceeding the
- <body> tag if it doesn't contain <span class=
- "QUOTE">"OnUnload"</span>, but the page's content does.
- </p>
- <p>
- The last example is from the fun department:
- </p>
- <p>
- </p>
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
-<pre class="SCREEN">
+ <p>Including the <a href=
+ "http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-htmlevents"
+ target="_top">OnUnload event binding</a> in the HTML DOM was a
+ <span class="emphasis"><i class="EMPHASIS">CRIME</i></span>. When I
+ close a browser window, I want it to close and die. Basta. This job
+ replaces the <span class="QUOTE">"onunload"</span> attribute in
+ <span class="QUOTE">"<body>"</span> tags with the dummy word
+ <tt class="LITERAL">never</tt>. Note that the <tt class=
+ "LITERAL">i</tt> option makes the pattern matching case-insensitive.
+ Also note that ungreedy matching alone doesn't always guarantee a
+ minimal match: In the first parenthesis, we had to use <tt class=
+ "LITERAL">[^>]*</tt> instead of <tt class="LITERAL">.*</tt> to
+ prevent the match from exceeding the <body> tag if it doesn't
+ contain <span class="QUOTE">"OnUnload"</span>, but the page's content
+ does.</p>
+
+ <p>The last example is from the fun department:</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
FILTER: fun Fun text replacements
# Spice the daily news:
#
s/microsoft(?!\.com)/MicroSuck/ig
</pre>
- </td>
- </tr>
- </table>
+ </td>
+ </tr>
+ </table>
- <p>
- Note the <tt class="LITERAL">(?!\.com)</tt> part (a so-called
- negative lookahead) in the job's pattern, which means: Don't match,
- if the string <span class="QUOTE">".com"</span> appears directly
- following <span class="QUOTE">"microsoft"</span> in the page. This
- prevents links to microsoft.com from being trashed, while still
- replacing the word everywhere else.
- </p>
- <p>
- </p>
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
-<pre class="SCREEN">
+ <p>Note the <tt class="LITERAL">(?!\.com)</tt> part (a so-called
+ negative lookahead) in the job's pattern, which means: Don't match, if
+ the string <span class="QUOTE">".com"</span> appears directly following
+ <span class="QUOTE">"microsoft"</span> in the page. This prevents links
+ to microsoft.com from being trashed, while still replacing the word
+ everywhere else.</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
# Buzzword Bingo (example for extended regex syntax)
#
s* industry[ -]leading \
*<font color="red"><b>BINGO!</b></font> \
*igx
</pre>
- </td>
- </tr>
- </table>
+ </td>
+ </tr>
+ </table>
- <p>
- The <tt class="LITERAL">x</tt> option in this job turns on extended
- syntax, and allows for e.g. the liberal use of (non-interpreted!)
- whitespace for nicer formatting.
- </p>
- <p>
- You get the idea?
- </p>
- </div>
- <div class="SECT2">
- <h2 class="SECT2">
- <a name="PREDEFINED-FILTERS">9.2. The Pre-defined Filters</a>
- </h2>
- <p>
- The distribution <tt class="FILENAME">default.filter</tt> file
- contains a selection of pre-defined filters for your convenience:
- </p>
- <div class="VARIABLELIST">
- <dl>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">js-annoyances</i></span>
- </dt>
- <dd>
- <p>
- The purpose of this filter is to get rid of particularly
- annoying JavaScript abuse. To that end, it
- </p>
- <ul>
- <li>
- <p>
- replaces JavaScript references to the browser's referrer
- information with the string "Not Your Business!". This
- compliments the <tt class="LITERAL"><a href=
- "actions-file.html#HIDE-REFERRER">hide-referrer</a></tt>
- action on the content level.
- </p>
- </li>
- <li>
- <p>
- removes the bindings to the DOM's <a href=
- "http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-htmlevents"
- target="_top">unload event</a> which we feel has no
- right to exist and is responsible for most <span class=
- "QUOTE">"exit consoles"</span>, i.e. nasty windows that
- pop up when you close another one.
- </p>
- </li>
- <li>
- <p>
- removes code that causes new windows to be opened with
- undesired properties, such as being full-screen,
- non-resizeable, without location, status or menu bar etc.
- </p>
- </li>
- </ul>
-
- <p>
- Use with caution. This is an aggressive filter, and can break
- sites that rely heavily on JavaScript.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class="EMPHASIS">js-events</i></span>
- </dt>
- <dd>
- <p>
- This is a very radical measure. It removes virtually all
- JavaScript event bindings, which means that scripts can not
- react to user actions such as mouse movements or clicks,
- window resizing etc, anymore. Use with caution!
- </p>
- <p>
- We <span class="emphasis"><i class="EMPHASIS">strongly
- discourage</i></span> using this filter as a default since it
- breaks many legitimate scripts. It is meant for use only on
- extra-nasty sites (should you really need to go there).
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">html-annoyances</i></span>
- </dt>
- <dd>
- <p>
- This filter will undo many common instances of HTML based
- abuse.
- </p>
- <p>
- The <tt class="LITERAL">BLINK</tt> and <tt class=
- "LITERAL">MARQUEE</tt> tags are neutralized (yeah baby!), and
- browser windows will be created as resizeable (as of course
- they should be!), and will have location, scroll and menu
- bars -- even if specified otherwise.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">content-cookies</i></span>
- </dt>
- <dd>
- <p>
- Most cookies are set in the HTTP dialog, where they can be
- intercepted by the <tt class="LITERAL"><a href=
- "actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</a></tt>
- and <tt class="LITERAL"><a href=
- "actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</a></tt>
- actions. But web sites increasingly make use of HTML meta
- tags and JavaScript to sneak cookies to the browser on the
- content level.
- </p>
- <p>
- This filter disables most HTML and JavaScript code that reads
- or sets cookies. It cannot detect all clever uses of these
- types of code, so it should not be relied on as an absolute
- fix. Use it wherever you would also use the cookie crunch
- actions.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">refresh-tags</i></span>
- </dt>
- <dd>
- <p>
- Disable any refresh tags if the interval is greater than nine
- seconds (so that redirections done via refresh tags are not
- destroyed). This is useful for dial-on-demand setups, or for
- those who find this HTML feature annoying.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">unsolicited-popups</i></span>
- </dt>
- <dd>
- <p>
- This filter attempts to prevent only <span class=
- "QUOTE">"unsolicited"</span> pop-up windows from opening, yet
- still allow pop-up windows that the user has explicitly
- chosen to open. It was added in version 3.0.1, as an
- improvement over earlier such filters.
- </p>
- <p>
- Technical note: The filter works by redefining the
- window.open JavaScript function to a dummy function, <tt
- class="LITERAL">PrivoxyWindowOpen()</tt>, during the loading
- and rendering phase of each HTML page access, and restoring
- the function afterward.
- </p>
- <p>
- This is recommended only for browsers that cannot perform
- this function reliably themselves. And be aware that some
- sites require such windows in order to function normally. Use
- with caution.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">all-popups</i></span>
- </dt>
- <dd>
- <p>
- Attempt to prevent <span class="emphasis"><i class=
- "EMPHASIS">all</i></span> pop-up windows from opening. Note
- this should be used with even more discretion than the above,
- since it is more likely to break some sites that require
- pop-ups for normal usage. Use with caution.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">img-reorder</i></span>
- </dt>
- <dd>
- <p>
- This is a helper filter that has no value if used alone. It
- makes the <tt class="LITERAL">banners-by-size</tt> and <tt
- class="LITERAL">banners-by-link</tt> (see below) filters more
- effective and should be enabled together with them.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">banners-by-size</i></span>
- </dt>
- <dd>
- <p>
- This filter removes image tags purely based on what size they
- are. Fortunately for us, many ads and banner images tend to
- conform to certain standardized sizes, which makes this
- filter quite effective for ad stripping purposes.
- </p>
- <p>
- Occasionally this filter will cause false positives on images
- that are not ads, but just happen to be of one of the
- standard banner sizes.
- </p>
- <p>
- Recommended only for those who require extreme ad blocking.
- The default block rules should catch 95+% of all ads <span
- class="emphasis"><i class="EMPHASIS">without</i></span> this
- filter enabled.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">banners-by-link</i></span>
- </dt>
- <dd>
- <p>
- This is an experimental filter that attempts to kill any
- banners if their URLs seem to point to known or suspected
- click trackers. It is currently not of much value and is not
- recommended for use by default.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class="EMPHASIS">webbugs</i></span>
- </dt>
- <dd>
- <p>
- Webbugs are small, invisible images (technically 1X1 GIF
- images), that are used to track users across websites, and
- collect information on them. As an HTML page is loaded by the
- browser, an embedded image tag causes the browser to contact
- a third-party site, disclosing the tracking information
- through the requested URL and/or cookies for that third-party
- domain, without the user ever becoming aware of the
- interaction with the third-party site. HTML-ized spam also
- uses a similar technique to verify email addresses.
- </p>
- <p>
- This filter removes the HTML code that loads such <span
- class="QUOTE">"webbugs"</span>.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">tiny-textforms</i></span>
- </dt>
- <dd>
- <p>
- A rather special-purpose filter that can be used to enlarge
- textareas (those multi-line text boxes in web forms) and turn
- off hard word wrap in them. It was written for the
- sourceforge.net tracker system where such boxes are a
- nuisance, but it can be handy on other sites, too.
- </p>
- <p>
- It is not recommended to use this filter as a default.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">jumping-windows</i></span>
- </dt>
- <dd>
- <p>
- Many consider windows that move, or resize themselves to be
- abusive. This filter neutralizes the related JavaScript code.
- Note that some sites might not display or behave as intended
- when using this filter. Use with caution.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">frameset-borders</i></span>
- </dt>
- <dd>
- <p>
- Some web designers seem to assume that everyone in the world
- will view their web sites using the same browser brand and
- version, screen resolution etc, because only that assumption
- could explain why they'd use static frame sizes, yet prevent
- their frames from being resized by the user, should they be
- too small to show their whole content.
- </p>
- <p>
- This filter removes the related HTML code. It should only be
- applied to sites which need it.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">demoronizer</i></span>
- </dt>
- <dd>
- <p>
- Many Microsoft products that generate HTML use non-standard
- extensions (read: violations) of the ISO 8859-1 aka Latin-1
- character set. This can cause those HTML documents to display
- with errors on standard-compliant platforms.
- </p>
- <p>
- This filter translates the MS-only characters into Latin-1
- equivalents. It is not necessary when using MS products, and
- will cause corruption of all documents that use 8-bit
- character sets other than Latin-1. It's mostly worthwhile for
- Europeans on non-MS platforms, if weird garbage characters
- sometimes appear on some pages, or user agents that don't
- correct for this on the fly.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">shockwave-flash</i></span>
- </dt>
- <dd>
- <p>
- A filter for shockwave haters. As the name suggests, this
- filter strips code out of web pages that is used to embed
- shockwave flash objects.
- </p>
- <p>
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">quicktime-kioskmode</i></span>
- </dt>
- <dd>
- <p>
- Change HTML code that embeds Quicktime objects so that
- kioskmode, which prevents saving, is disabled.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class="EMPHASIS">fun</i></span>
- </dt>
- <dd>
- <p>
- Text replacements for subversive browsing fun. Make fun of
- your favorite Monopolist or play buzzword bingo.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">crude-parental</i></span>
- </dt>
- <dd>
- <p>
- A demonstration-only filter that shows how <span class=
- "APPLICATION">Privoxy</span> can be used to delete web
- content on a keyword basis.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">ie-exploits</i></span>
- </dt>
- <dd>
- <p>
- An experimental collection of text replacements to disable
- malicious HTML and JavaScript code that exploits known
- security holes in Internet Explorer.
- </p>
- <p>
- Presently, it only protects against Nimda and a cross-site
- scripting bug, and would need active maintenance to provide
- more substantial protection.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">site-specifics</i></span>
- </dt>
- <dd>
- <p>
- Some web sites have very specific problems, the cure for
- which doesn't apply anywhere else, or could even cause damage
- on other sites.
- </p>
- <p>
- This is a collection of such site-specific cures which should
- only be applied to the sites they were intended for, which is
- what the supplied <tt class="FILENAME">default.action</tt>
- file does. Users shouldn't need to change anything regarding
- this filter.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class="EMPHASIS">google</i></span>
- </dt>
- <dd>
- <p>
- A CSS based block for Google text ads. Also removes a width
- limitation and the toolbar advertisement.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class="EMPHASIS">yahoo</i></span>
- </dt>
- <dd>
- <p>
- Another CSS based block, this time for Yahoo text ads. And
- removes a width limitation as well.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class="EMPHASIS">msn</i></span>
- </dt>
- <dd>
- <p>
- Another CSS based block, this time for MSN text ads. And
- removes tracking URLs, as well as a width limitation.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class="EMPHASIS">blogspot</i></span>
- </dt>
- <dd>
- <p>
- Cleans up some Blogspot blogs. Read the fine print before
- using this one!
- </p>
- <p>
- This filter also intentionally removes some navigation stuff
- and sets the page width to 100%. As a result, some rounded
- <span class="QUOTE">"corners"</span> would appear to early or
- not at all and as fixing this would require a browser that
- understands background-size (CSS3), they are removed instead.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">xml-to-html</i></span>
- </dt>
- <dd>
- <p>
- Server-header filter to change the Content-Type from xml to
- html.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">html-to-xml</i></span>
- </dt>
- <dd>
- <p>
- Server-header filter to change the Content-Type from html to
- xml.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class="EMPHASIS">no-ping</i></span>
- </dt>
- <dd>
- <p>
- Removes the non-standard <tt class="LITERAL">ping</tt>
- attribute from anchor and area HTML tags.
- </p>
- </dd>
- <dt>
- <span class="emphasis"><i class=
- "EMPHASIS">hide-tor-exit-notation</i></span>
- </dt>
- <dd>
- <p>
- Client-header filter to remove the <b class="COMMAND">Tor</b>
- exit node notation found in Host and Referer headers.
- </p>
- <p>
- If <span class="APPLICATION">Privoxy</span> and <b class=
- "COMMAND">Tor</b> are chained and <span class=
- "APPLICATION">Privoxy</span> is configured to use socks4a,
- one can use <span class=
- "QUOTE">"http://www.example.org.foobar.exit/"</span> to
- access the host <span class="QUOTE">"www.example.org"</span>
- through the <b class="COMMAND">Tor</b> exit node <span class=
- "QUOTE">"foobar"</span>.
- </p>
- <p>
- As the HTTP client isn't aware of this notation, it treats
- the whole string <span class=
- "QUOTE">"www.example.org.foobar.exit"</span> as host and uses
- it for the <span class="QUOTE">"Host"</span> and <span class=
- "QUOTE">"Referer"</span> headers. From the server's point of
- view the resulting headers are invalid and can cause
- problems.
- </p>
- <p>
- An invalid <span class="QUOTE">"Referer"</span> header can
- trigger <span class="QUOTE">"hot-linking"</span> protections,
- an invalid <span class="QUOTE">"Host"</span> header will make
- it impossible for the server to find the right vhost (several
- domains hosted on the same IP address).
- </p>
- <p>
- This client-header filter removes the <span class=
- "QUOTE">"foo.exit"</span> part in those headers to prevent
- the mentioned problems. Note that it only modifies the HTTP
- headers, it doesn't make it impossible for the server to
- detect your <b class="COMMAND">Tor</b> exit node based on the
- IP address the request is coming from.
- </p>
- </dd>
- </dl>
- </div>
+ <p>The <tt class="LITERAL">x</tt> option in this job turns on extended
+ syntax, and allows for e.g. the liberal use of (non-interpreted!)
+ whitespace for nicer formatting.</p>
+
+ <p>You get the idea?</p>
+ </div>
+
+ <div class="SECT2">
+ <h2 class="SECT2"><a name="PREDEFINED-FILTERS" id=
+ "PREDEFINED-FILTERS">9.2. The Pre-defined Filters</a></h2>
+
+ <p>The distribution <tt class="FILENAME">default.filter</tt> file
+ contains a selection of pre-defined filters for your convenience:</p>
+
+ <div class="VARIABLELIST">
+ <dl>
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">js-annoyances</i></span></dt>
+
+ <dd>
+ <p>The purpose of this filter is to get rid of particularly
+ annoying JavaScript abuse. To that end, it</p>
+
+ <ul>
+ <li>
+ <p>replaces JavaScript references to the browser's referrer
+ information with the string "Not Your Business!". This
+ compliments the <tt class="LITERAL"><a href=
+ "actions-file.html#HIDE-REFERRER">hide-referrer</a></tt>
+ action on the content level.</p>
+ </li>
+
+ <li>
+ <p>removes the bindings to the DOM's <a href=
+ "http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-htmlevents"
+ target="_top">unload event</a> which we feel has no right to
+ exist and is responsible for most <span class="QUOTE">"exit
+ consoles"</span>, i.e. nasty windows that pop up when you
+ close another one.</p>
+ </li>
+
+ <li>
+ <p>removes code that causes new windows to be opened with
+ undesired properties, such as being full-screen,
+ non-resizeable, without location, status or menu bar etc.</p>
+ </li>
+ </ul>
+
+ <p>Use with caution. This is an aggressive filter, and can break
+ sites that rely heavily on JavaScript.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">js-events</i></span></dt>
+
+ <dd>
+ <p>This is a very radical measure. It removes virtually all
+ JavaScript event bindings, which means that scripts can not react
+ to user actions such as mouse movements or clicks, window
+ resizing etc, anymore. Use with caution!</p>
+
+ <p>We <span class="emphasis"><i class="EMPHASIS">strongly
+ discourage</i></span> using this filter as a default since it
+ breaks many legitimate scripts. It is meant for use only on
+ extra-nasty sites (should you really need to go there).</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">html-annoyances</i></span></dt>
+
+ <dd>
+ <p>This filter will undo many common instances of HTML based
+ abuse.</p>
+
+ <p>The <tt class="LITERAL">BLINK</tt> and <tt class=
+ "LITERAL">MARQUEE</tt> tags are neutralized (yeah baby!), and
+ browser windows will be created as resizeable (as of course they
+ should be!), and will have location, scroll and menu bars -- even
+ if specified otherwise.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">content-cookies</i></span></dt>
+
+ <dd>
+ <p>Most cookies are set in the HTTP dialog, where they can be
+ intercepted by the <tt class="LITERAL"><a href=
+ "actions-file.html#CRUNCH-INCOMING-COOKIES">crunch-incoming-cookies</a></tt>
+ and <tt class="LITERAL"><a href=
+ "actions-file.html#CRUNCH-OUTGOING-COOKIES">crunch-outgoing-cookies</a></tt>
+ actions. But web sites increasingly make use of HTML meta tags
+ and JavaScript to sneak cookies to the browser on the content
+ level.</p>
+
+ <p>This filter disables most HTML and JavaScript code that reads
+ or sets cookies. It cannot detect all clever uses of these types
+ of code, so it should not be relied on as an absolute fix. Use it
+ wherever you would also use the cookie crunch actions.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">refresh-tags</i></span></dt>
+
+ <dd>
+ <p>Disable any refresh tags if the interval is greater than nine
+ seconds (so that redirections done via refresh tags are not
+ destroyed). This is useful for dial-on-demand setups, or for
+ those who find this HTML feature annoying.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">unsolicited-popups</i></span></dt>
+
+ <dd>
+ <p>This filter attempts to prevent only <span class=
+ "QUOTE">"unsolicited"</span> pop-up windows from opening, yet
+ still allow pop-up windows that the user has explicitly chosen to
+ open. It was added in version 3.0.1, as an improvement over
+ earlier such filters.</p>
+
+ <p>Technical note: The filter works by redefining the window.open
+ JavaScript function to a dummy function, <tt class=
+ "LITERAL">PrivoxyWindowOpen()</tt>, during the loading and
+ rendering phase of each HTML page access, and restoring the
+ function afterward.</p>
+
+ <p>This is recommended only for browsers that cannot perform this
+ function reliably themselves. And be aware that some sites
+ require such windows in order to function normally. Use with
+ caution.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">all-popups</i></span></dt>
+
+ <dd>
+ <p>Attempt to prevent <span class="emphasis"><i class=
+ "EMPHASIS">all</i></span> pop-up windows from opening. Note this
+ should be used with even more discretion than the above, since it
+ is more likely to break some sites that require pop-ups for
+ normal usage. Use with caution.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">img-reorder</i></span></dt>
+
+ <dd>
+ <p>This is a helper filter that has no value if used alone. It
+ makes the <tt class="LITERAL">banners-by-size</tt> and <tt class=
+ "LITERAL">banners-by-link</tt> (see below) filters more effective
+ and should be enabled together with them.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">banners-by-size</i></span></dt>
+
+ <dd>
+ <p>This filter removes image tags purely based on what size they
+ are. Fortunately for us, many ads and banner images tend to
+ conform to certain standardized sizes, which makes this filter
+ quite effective for ad stripping purposes.</p>
+
+ <p>Occasionally this filter will cause false positives on images
+ that are not ads, but just happen to be of one of the standard
+ banner sizes.</p>
+
+ <p>Recommended only for those who require extreme ad blocking.
+ The default block rules should catch 95+% of all ads <span class=
+ "emphasis"><i class="EMPHASIS">without</i></span> this filter
+ enabled.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">banners-by-link</i></span></dt>
+
+ <dd>
+ <p>This is an experimental filter that attempts to kill any
+ banners if their URLs seem to point to known or suspected click
+ trackers. It is currently not of much value and is not
+ recommended for use by default.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">webbugs</i></span></dt>
+
+ <dd>
+ <p>Webbugs are small, invisible images (technically 1X1 GIF
+ images), that are used to track users across websites, and
+ collect information on them. As an HTML page is loaded by the
+ browser, an embedded image tag causes the browser to contact a
+ third-party site, disclosing the tracking information through the
+ requested URL and/or cookies for that third-party domain, without
+ the user ever becoming aware of the interaction with the
+ third-party site. HTML-ized spam also uses a similar technique to
+ verify email addresses.</p>
+
+ <p>This filter removes the HTML code that loads such <span class=
+ "QUOTE">"webbugs"</span>.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">tiny-textforms</i></span></dt>
+
+ <dd>
+ <p>A rather special-purpose filter that can be used to enlarge
+ textareas (those multi-line text boxes in web forms) and turn off
+ hard word wrap in them. It was written for the sourceforge.net
+ tracker system where such boxes are a nuisance, but it can be
+ handy on other sites, too.</p>
+
+ <p>It is not recommended to use this filter as a default.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">jumping-windows</i></span></dt>
+
+ <dd>
+ <p>Many consider windows that move, or resize themselves to be
+ abusive. This filter neutralizes the related JavaScript code.
+ Note that some sites might not display or behave as intended when
+ using this filter. Use with caution.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">frameset-borders</i></span></dt>
+
+ <dd>
+ <p>Some web designers seem to assume that everyone in the world
+ will view their web sites using the same browser brand and
+ version, screen resolution etc, because only that assumption
+ could explain why they'd use static frame sizes, yet prevent
+ their frames from being resized by the user, should they be too
+ small to show their whole content.</p>
+
+ <p>This filter removes the related HTML code. It should only be
+ applied to sites which need it.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">demoronizer</i></span></dt>
+
+ <dd>
+ <p>Many Microsoft products that generate HTML use non-standard
+ extensions (read: violations) of the ISO 8859-1 aka Latin-1
+ character set. This can cause those HTML documents to display
+ with errors on standard-compliant platforms.</p>
+
+ <p>This filter translates the MS-only characters into Latin-1
+ equivalents. It is not necessary when using MS products, and will
+ cause corruption of all documents that use 8-bit character sets
+ other than Latin-1. It's mostly worthwhile for Europeans on
+ non-MS platforms, if weird garbage characters sometimes appear on
+ some pages, or user agents that don't correct for this on the
+ fly.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">shockwave-flash</i></span></dt>
+
+ <dd>
+ <p>A filter for shockwave haters. As the name suggests, this
+ filter strips code out of web pages that is used to embed
+ shockwave flash objects.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">quicktime-kioskmode</i></span></dt>
+
+ <dd>
+ <p>Change HTML code that embeds Quicktime objects so that
+ kioskmode, which prevents saving, is disabled.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class="EMPHASIS">fun</i></span></dt>
+
+ <dd>
+ <p>Text replacements for subversive browsing fun. Make fun of
+ your favorite Monopolist or play buzzword bingo.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">crude-parental</i></span></dt>
+
+ <dd>
+ <p>A demonstration-only filter that shows how <span class=
+ "APPLICATION">Privoxy</span> can be used to delete web content on
+ a keyword basis.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">ie-exploits</i></span></dt>
+
+ <dd>
+ <p>An experimental collection of text replacements to disable
+ malicious HTML and JavaScript code that exploits known security
+ holes in Internet Explorer.</p>
+
+ <p>Presently, it only protects against Nimda and a cross-site
+ scripting bug, and would need active maintenance to provide more
+ substantial protection.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">site-specifics</i></span></dt>
+
+ <dd>
+ <p>Some web sites have very specific problems, the cure for which
+ doesn't apply anywhere else, or could even cause damage on other
+ sites.</p>
+
+ <p>This is a collection of such site-specific cures which should
+ only be applied to the sites they were intended for, which is
+ what the supplied <tt class="FILENAME">default.action</tt> file
+ does. Users shouldn't need to change anything regarding this
+ filter.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">google</i></span></dt>
+
+ <dd>
+ <p>A CSS based block for Google text ads. Also removes a width
+ limitation and the toolbar advertisement.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">yahoo</i></span></dt>
+
+ <dd>
+ <p>Another CSS based block, this time for Yahoo text ads. And
+ removes a width limitation as well.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class="EMPHASIS">msn</i></span></dt>
+
+ <dd>
+ <p>Another CSS based block, this time for MSN text ads. And
+ removes tracking URLs, as well as a width limitation.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">blogspot</i></span></dt>
+
+ <dd>
+ <p>Cleans up some Blogspot blogs. Read the fine print before
+ using this one!</p>
+
+ <p>This filter also intentionally removes some navigation stuff
+ and sets the page width to 100%. As a result, some rounded
+ <span class="QUOTE">"corners"</span> would appear to early or not
+ at all and as fixing this would require a browser that
+ understands background-size (CSS3), they are removed instead.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">xml-to-html</i></span></dt>
+
+ <dd>
+ <p>Server-header filter to change the Content-Type from xml to
+ html.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">html-to-xml</i></span></dt>
+
+ <dd>
+ <p>Server-header filter to change the Content-Type from html to
+ xml.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">no-ping</i></span></dt>
+
+ <dd>
+ <p>Removes the non-standard <tt class="LITERAL">ping</tt>
+ attribute from anchor and area HTML tags.</p>
+ </dd>
+
+ <dt><span class="emphasis"><i class=
+ "EMPHASIS">hide-tor-exit-notation</i></span></dt>
+
+ <dd>
+ <p>Client-header filter to remove the <b class="COMMAND">Tor</b>
+ exit node notation found in Host and Referer headers.</p>
+
+ <p>If <span class="APPLICATION">Privoxy</span> and <b class=
+ "COMMAND">Tor</b> are chained and <span class=
+ "APPLICATION">Privoxy</span> is configured to use socks4a, one
+ can use <span class=
+ "QUOTE">"http://www.example.org.foobar.exit/"</span> to access
+ the host <span class="QUOTE">"www.example.org"</span> through the
+ <b class="COMMAND">Tor</b> exit node <span class=
+ "QUOTE">"foobar"</span>.</p>
+
+ <p>As the HTTP client isn't aware of this notation, it treats the
+ whole string <span class=
+ "QUOTE">"www.example.org.foobar.exit"</span> as host and uses it
+ for the <span class="QUOTE">"Host"</span> and <span class=
+ "QUOTE">"Referer"</span> headers. From the server's point of view
+ the resulting headers are invalid and can cause problems.</p>
+
+ <p>An invalid <span class="QUOTE">"Referer"</span> header can
+ trigger <span class="QUOTE">"hot-linking"</span> protections, an
+ invalid <span class="QUOTE">"Host"</span> header will make it
+ impossible for the server to find the right vhost (several
+ domains hosted on the same IP address).</p>
+
+ <p>This client-header filter removes the <span class=
+ "QUOTE">"foo.exit"</span> part in those headers to prevent the
+ mentioned problems. Note that it only modifies the HTTP headers,
+ it doesn't make it impossible for the server to detect your
+ <b class="COMMAND">Tor</b> exit node based on the IP address the
+ request is coming from.</p>
+ </dd>
+ </dl>
</div>
- <div class="SECT2">
- <h2 class="SECT2">
- <a name="EXTERNAL-FILTER-SYNTAX">9.3. External filter syntax</a>
- </h2>
- <p>
- External filters are scripts or programs that can modify the
- content in case common <tt class="LITERAL"><a href=
- "actions-file.html#FILTER">filters</a></tt> aren't powerful enough.
- </p>
- <p>
- External filters can be written in any language the platform <span
- class="APPLICATION">Privoxy</span> runs on supports.
- </p>
- <p>
- They are controlled with the <tt class="LITERAL"><a href=
- "actions-file.html#EXTERNAL-FILTER">external-filter</a></tt> action
- and have to be defined in the <tt class="LITERAL"><a href=
- "config.html#FILTERFILE">filterfile</a></tt> first.
- </p>
- <p>
- The header looks like any other filter, but instead of pcrs jobs,
- external filters contain a single job which can be a program or a
- shell script (which may call other scripts or programs).
- </p>
- <p>
- External filters read the content from STDIN and write the
- rewritten content to STDOUT. The environment variables PRIVOXY_URL,
- PRIVOXY_PATH, PRIVOXY_HOST, PRIVOXY_ORIGIN, PRIVOXY_LISTEN_ADDRESS
- can be used to get some details about the client request.
- </p>
- <p>
- <span class="APPLICATION">Privoxy</span> will temporary store the
- content to filter in the <tt class="LITERAL"><a href=
- "config.html#TEMPORARY-DIRECTORY">temporary-directory</a></tt>.
- </p>
- <p>
- </p>
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
-<pre class="SCREEN">
+ </div>
+
+ <div class="SECT2">
+ <h2 class="SECT2"><a name="EXTERNAL-FILTER-SYNTAX" id=
+ "EXTERNAL-FILTER-SYNTAX">9.3. External filter syntax</a></h2>
+
+ <p>External filters are scripts or programs that can modify the content
+ in case common <tt class="LITERAL"><a href=
+ "actions-file.html#FILTER">filters</a></tt> aren't powerful enough.</p>
+
+ <p>External filters can be written in any language the platform
+ <span class="APPLICATION">Privoxy</span> runs on supports.</p>
+
+ <p>They are controlled with the <tt class="LITERAL"><a href=
+ "actions-file.html#EXTERNAL-FILTER">external-filter</a></tt> action and
+ have to be defined in the <tt class="LITERAL"><a href=
+ "config.html#FILTERFILE">filterfile</a></tt> first.</p>
+
+ <p>The header looks like any other filter, but instead of pcrs jobs,
+ external filters contain a single job which can be a program or a shell
+ script (which may call other scripts or programs).</p>
+
+ <p>External filters read the content from STDIN and write the rewritten
+ content to STDOUT. The environment variables PRIVOXY_URL, PRIVOXY_PATH,
+ PRIVOXY_HOST, PRIVOXY_ORIGIN, PRIVOXY_LISTEN_ADDRESS can be used to get
+ some details about the client request.</p>
+
+ <p><span class="APPLICATION">Privoxy</span> will temporary store the
+ content to filter in the <tt class="LITERAL"><a href=
+ "config.html#TEMPORARY-DIRECTORY">temporary-directory</a></tt>.</p>
+
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+ <pre class="SCREEN">
EXTERNAL-FILTER: cat Pointless example filter that doesn't actually modify the content
/bin/cat
EXTERNAL-FILTER: citation-needed Adds a "[citation needed]" tag to an image. The coordinates may need adjustment.
/usr/local/bin/convert - -pointsize 16 -fill white -annotate +17+418 "[citation needed]" -
</pre>
+ </td>
+ </tr>
+ </table>
+
+ <div class="WARNING">
+ <table class="WARNING" border="1" width="100%">
+ <tr>
+ <td align="center"><b>Warning</b></td>
+ </tr>
+
+ <tr>
+ <td align="left">
+ <p>Currently external filters are executed with <span class=
+ "APPLICATION">Privoxy</span>'s privileges! Only use external
+ filters you understand and trust.</p>
</td>
</tr>
</table>
-
- <div class="WARNING">
- <table class="WARNING" border="1" width="100%">
- <tr>
- <td align="CENTER">
- <b>Warning</b>
- </td>
- </tr>
- <tr>
- <td align="LEFT">
- <p>
- Currently external filters are executed with <span class=
- "APPLICATION">Privoxy</span>'s privileges! Only use
- external filters you understand and trust.
- </p>
- </td>
- </tr>
- </table>
- </div>
- <p>
- External filters are experimental and the syntax may change in the
- future.
- </p>
</div>
+
+ <p>External filters are experimental and the syntax may change in the
+ future.</p>
</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="actions-file.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="templates.html" accesskey="N">Next</a>
- </td>
- </tr>
- <tr>
- <td width="33%" align="left" valign="top">
- Actions Files
- </td>
- <td width="34%" align="center" valign="top">
-
- </td>
- <td width="33%" align="right" valign="top">
- Privoxy's Template Files
- </td>
- </tr>
- </table>
- </div>
- </body>
-</html>
+ </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="actions-file.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="templates.html"
+ accesskey="N">Next</a></td>
+ </tr>
+
+ <tr>
+ <td width="33%" align="left" valign="top">Actions Files</td>
+
+ <td width="34%" align="center" valign="top"> </td>
+
+ <td width="33%" align="right" valign="top">Privoxy's Template
+ Files</td>
+ </tr>
+ </table>
+ </div>
+</body>
+</html>
projects / privoxy.git / blobdiff