# Check if www.example.net/ really uses valid XHTML
-{+content-type-overwrite {application/xml}}
+
+ Examples: +add-header{X-Fun-Header: Some
+ text} and +filter{html-annoyances}
+
+
+
+
+
+ If nothing is specified in any actions file, no "actions" are taken. So in this case Privoxy 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).
+
+
+ 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 user.action). 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 config (the default installation has three actions
+ files). It also quite possible for any given URL to match more than
+ one "pattern" (because of wildcards and
+ regular expressions), and thus to trigger more than one set of
+ actions! Last match wins.
+
+
+ The list of valid Privoxy actions
+ are:
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Confuse log analysis, custom applications
+
+
+ -
+ Effect:
+
+ -
+
+ Sends a user defined HTTP header to the web server.
+
+
+ -
+ Type:
+
+ -
+
+ Multi-value.
+
+
+ -
+ Parameter:
+
+ -
+
+ Any string value is possible. Validity of the defined HTTP
+ headers is not checked. It is recommended that you use the
+ "X-"
+ prefix for custom headers.
+
+
+ -
+ Notes:
+
+ -
+
+ 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 "HTTP headers" are, you definitely don't
+ need to worry about this one.
+
+
+ Headers added by this action are not modified by other
+ actions.
+
+
+ -
+ Example usage:
+
+ -
+
+
+
+
+
+
+# Add a DNT ("Do not track") header to all requests,
+# event to those that already have one.
+#
+# This is just an example, not a recommendation.
+#
+# There is no reason to believe that user-tracking websites care
+# about the DNT header and depending on the User-Agent, adding the
+# header may make user-tracking easier.
+{+add-header{DNT: 1}}
+/
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Block ads or other unwanted content
+
+
+ -
+ Effect:
+
+ -
+
+ Requests for URLs to which this action applies are blocked,
+ i.e. the requests are trapped by Privoxy and the requested URL is never
+ retrieved, but is answered locally with a substitute page
+ or image, as determined by the handle-as-image,
+ set-image-blocker,
+ and handle-as-empty-document
+ actions.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized.
+
+
+ -
+ Parameter:
+
+ -
+
+ A block reason that should be given to the user.
+
+
+ -
+ Notes:
+
+ -
+
+ Privoxy sends a special
+ "BLOCKED" 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).
+
+
+ A very important exception occurs if both block and handle-as-image,
+ apply to the same request: it will then be replaced by an
+ image. If set-image-blocker
+ (see below) also applies, the type of image will be
+ determined by its parameter, if not, the standard
+ checkerboard pattern is sent.
+
+
+ It is important to understand this process, in order to
+ understand how Privoxy
+ deals with ads and other unwanted content. Blocking is a
+ core feature, and one upon which various other features
+ depend.
+
+
+ The filter action can
+ perform a very similar task, by "blocking" 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.
+
+
+ -
+ Example usage (section):
+
+ -
+
+
+
+
+
+
+{+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$
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Improve privacy by not forwarding the source of the request
+ in the HTTP headers.
+
+
+ -
+ Effect:
+
+ -
+
+ Deletes the "X-Forwarded-For:"
+ HTTP header from the client request, or adds a new one.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized.
+
+
+ -
+ Parameter:
+
+ -
+
+
+ -
+ Notes:
+
+ -
+
+ It is safe and recommended to use block.
+
+
+ Forwarding the source address of the request may make sense
+ in some multi-user setups but is also a privacy risk.
+
+
+ -
+ Example usage:
+
+ -
+
+
+
+
+
+
++change-x-forwarded-for{block}
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Rewrite or remove single client headers.
+
+
+ -
+ Effect:
+
+ -
+
+ All client headers to which this action applies are
+ filtered on-the-fly through the specified regular
+ expression based substitutions.
+
+
+ -
+ Type:
+
+ -
+
+ Multi-value.
+
+
+ -
+ Parameter:
+
+ -
+
+ The name of a client-header filter, as defined in one of
+ the filter files.
+
+
+ -
+ Notes:
+
+ -
+
+ 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.
+
+
+ Client-header filters are executed after the other header
+ actions have finished and use their output as input.
+
+
+ If the request URI gets changed, Privoxy 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.
+
+
+ Please refer to the filter file
+ chapter to learn which client-header filters are
+ available by default, and how to create your own.
+
+
+ -
+ Example usage (section):
+
+ -
+
+
+
+
+
+
+# Hide Tor exit notation in Host and Referer Headers
+{+client-header-filter{hide-tor-exit-notation}}
+/
+
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Block requests based on their headers.
+
+
+ -
+ Effect:
+
+ -
+
+ 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.
+
+
+ -
+ Type:
+
+ -
+
+ Multi-value.
+
+
+ -
+ Parameter:
+
+ -
+
+ The name of a client-header tagger, as defined in one of
+ the filter files.
+
+
+ -
+ Notes:
+
+ -
+
+ Client-header taggers are applied to each header on its
+ own, and as the header isn't modified, each tagger "sees" the original.
+
+
+ Client-header taggers are the first actions that are
+ executed and their tags can be used to control every other
+ action.
+
+
+ -
+ Example usage (section):
+
+ -
+
+
+
+
+
+
+# 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/
+
+
+ |
+
+
+
+
+
+
+
+
+
+# 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$
+
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Stop useless download menus from popping up, or change the
+ browser's rendering mode
+
+
+ -
+ Effect:
+
+ -
+
+ Replaces the "Content-Type:"
+ HTTP server header.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized.
+
+
+ -
+ Parameter:
+
+ -
+
+ Any string.
+
+
+ -
+ Notes:
+
+ -
+
+ The "Content-Type:" 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.
+
+
+ The declared content type can also affect which rendering
+ mode the browser chooses. If XHTML is delivered as "text/html", many browsers treat it as
+ yet another broken HTML document. If it is send as "application/xml", browsers with XHTML
+ support will only display it, if the syntax is correct.
+
+
+ If you see a web site that proudly uses XHTML buttons, but
+ sets "Content-Type: text/html",
+ you can use Privoxy to
+ overwrite it with "application/xml" and validate the web
+ master's claim inside your XHTML-supporting browser. If the
+ syntax is incorrect, the browser will complain loudly.
+
+
+ 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 "text/html" and have
+ it rendered as broken HTML document.
+
+
+ By default content-type-overwrite
+ only replaces "Content-Type:"
+ headers that look like some kind of text. If you want to
+ overwrite it unconditionally, you have to combine it with
+ force-text-mode.
+ This limitation exists for a reason, think twice before
+ circumventing it.
+
+
+ Most of the time it's easier to replace this action with a
+ custom server-header
+ filter. 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.
+
+
+ Of course you can apply content-type-overwrite to a whole site and
+ then make URL based exceptions, but it's a lot more work to
+ get the same precision.
+
+
+ -
+ Example usage (sections):
+
+ -
+
+
+
+
+
+
+# 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 |
- 8.5.4. crunch-server-header- Typical use:
Remove a client header Privoxy has no dedicated action for. - Effect:
Deletes every header send by the client that contains the string the user supplied as parameter.
- - Type:
Parameterized. - Parameter:
Any string.
- - Notes:
This action allows you to block client headers for which no dedicated
- Privoxy action exists.
- Privoxy will remove every client header that
- contains the string you supplied as parameter.
- Regular expressions are not supported and you can't
- use this action to block different headers in the same request, unless
- they contain the same string.
- crunch-client-header is only meant for quick tests.
- If you have to block several different headers, or only want to modify
- parts of them, you should enable
- filter-client-headers
- and create your own filter.
- Warning | Don't block any header without understanding the consequences.
- |
- Example usage (section):
# Block the non-existent "Privacy-Violation:" client header
-{+crunch-client-header {Privacy-Violation:}}
+www.example.net/.*\.css$
+www.example.net/.*style
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Remove a client header Privoxy has no dedicated action for.
+
+
+ -
+ Effect:
+
+ -
+
+ Deletes every header sent by the client that contains the
+ string the user supplied as parameter.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized.
+
+
+ -
+ Parameter:
+
+ -
+
+ Any string.
+
+
+ -
+ Notes:
+
+ -
+
+ This action allows you to block client headers for which no
+ dedicated Privoxy action
+ exists. Privoxy will
+ remove every client header that contains the string you
+ supplied as parameter.
+
+
+ Regular expressions are not supported and you can't use this
+ action to block different headers in the same request,
+ unless they contain the same string.
+
+
+ crunch-client-header 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 client-header
+ filter.
+
+
+
+
+
+ Warning
+ |
+
+
+
+
+ Don't block any header without understanding the
+ consequences.
+
+ |
+
+
+
+
+ -
+ Example usage (section):
+
+ -
+
+
+
+
+
+
+# Block the non-existent "Privacy-Violation:" client header
+{ +crunch-client-header{Privacy-Violation:} }
+/
+
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Prevent yet another way to track the user's steps between
+ sessions.
+
+
+ -
+ Effect:
+
+ -
+
+ Deletes the "If-None-Match:"
+ HTTP client header.
+
+
+ -
+ Type:
+
+ -
+
+ Boolean.
+
+
+ -
+ Parameter:
+
+ -
+
+ N/A
+
+
+ -
+ Notes:
+
+ -
+
+ Removing the "If-None-Match:"
+ HTTP client header is useful for filter testing, where you
+ want to force a real reload instead of getting status code
+ "304" which would cause the
+ browser to use a cached copy of the page.
+
+
+ It is also useful to make sure the header isn't used as a
+ cookie replacement (unlikely but possible).
+
+
+ Blocking the "If-None-Match:"
+ header shouldn't cause any caching problems, as long as the
+ "If-Modified-Since:" header
+ isn't blocked or missing as well.
+
+
+ It is recommended to use this action together with hide-if-modified-since
+ and overwrite-last-modified.
+
+
+ -
+ Example usage (section):
+
+ -
+
+
+
+
+
+
+# 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}
+/
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Prevent the web server from setting HTTP cookies on your
+ system
+
+
+ -
+ Effect:
+
+ -
+
+ Deletes any "Set-Cookie:" HTTP
+ headers from server replies.
+
+
+ -
+ Type:
+
+ -
+
+ Boolean.
+
+
+ -
+ Parameter:
+
+ -
+
+ N/A
+
+
+ -
+ Notes:
+
+ -
+
+ This action is only concerned with incoming HTTP
+ cookies. For outgoing HTTP cookies, use crunch-outgoing-cookies.
+ Use both to disable HTTP cookies
+ completely.
+
+
+ It makes no
+ sense at all to use this action in conjunction
+ with the session-cookies-only
+ action, since it would prevent the session cookies from
+ being set. See also filter-content-cookies.
+
+
+ -
+ Example usage:
+
+ -
+
+
+
+
+
+
++crunch-incoming-cookies
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Remove a server header Privoxy has no dedicated action for.
+
+
+ -
+ Effect:
+
+ -
+
+ Deletes every header sent by the server that contains the
+ string the user supplied as parameter.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized.
+
+
+ -
+ Parameter:
+
+ -
+
+ Any string.
+
+
+ -
+ Notes:
+
+ -
+
+ This action allows you to block server headers for which no
+ dedicated Privoxy action
+ exists. Privoxy will
+ remove every server header that contains the string you
+ supplied as parameter.
+
+
+ Regular expressions are not supported and you can't use this
+ action to block different headers in the same request,
+ unless they contain the same string.
+
+
+ crunch-server-header 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 server-header
+ filter.
+
+
+
+
+
+ Warning
+ |
+
+
+
+
+ Don't block any header without understanding the
+ consequences.
+
+ |
+
+
+
+
+ -
+ Example usage (section):
+
+ -
+
+
+
+
+
+
+# Crunch server headers that try to prevent caching
+{ +crunch-server-header{no-cache} }
/
- |
- 8.5.5. crunch-if-none-match- Typical use:
Prevent yet another way to track the user's steps between sessions. - Effect:
Deletes the "If-None-Match:" HTTP client header.
- - Type:
Boolean. - Parameter:
N/A
- - Notes:
Removing the "If-None-Match:" HTTP client header
- is useful for filter testing, where you want to force a real
- reload instead of getting status code "304" which
- would cause the browser to use a cached copy of the page.
- It is also useful to make sure the header isn't used as a cookie
- replacement.
- Blocking the "If-None-Match:" header shouldn't cause any
- caching problems, as long as the "If-Modified-Since:" header
- isn't blocked as well.
- It is recommended to use this action together with
- hide-if-modified-since
- and
- overwrite-last-modified.
- - Example usage (section):
# Let the browser revalidate cached documents without being tracked across sessions
-{+hide-if-modified-since {-1} \
-+overwrite-last-modified {randomize} \
-+crunch-if-none-match}
-/ |
-
8.5.6. crunch-incoming-cookies- Typical use:
Prevent the web server from setting any cookies on your system
- - Effect:
Deletes any "Set-Cookie:" HTTP headers from server replies.
- - Type:
Boolean. - Parameter:
N/A
- - Notes:
This action is only concerned with incoming cookies. For
- outgoing cookies, use
- crunch-outgoing-cookies.
- Use both to disable cookies completely.
- It makes no sense at all to use this action in conjunction
- with the session-cookies-only action,
- since it would prevent the session cookies from being set. See also
- filter-content-cookies.
- - Example usage:
-
8.5.7. crunch-server-header- Typical use:
Remove a server header Privoxy has no dedicated action for. - Effect:
Deletes every header sent by the server that contains the string the user supplied as parameter.
- - Type:
Parameterized. - Parameter:
Any string.
- - Notes:
This action allows you to block server headers for which no dedicated
- Privoxy action exists. Privoxy
- will remove every server header that contains the string you supplied as parameter.
- Regular expressions are not supported and you can't
- use this action to block different headers in the same request, unless
- they contain the same string.
- crunch-server-header is only meant for quick tests.
- If you have to block several different headers, or only want to modify
- parts of them, you should enable
- filter-server-headers
- and create your own filter.
- Warning | Don't block any header without understanding the consequences.
- |
- Example usage (section):
# Crunch server headers that try to prevent caching
-{+crunch-server-header {no-cache}}
-/ |
-
8.5.8. crunch-outgoing-cookies- Typical use:
Prevent the web server from reading any cookies from your system
- - Effect:
Deletes any "Cookie:" HTTP headers from client requests.
- - Type:
Boolean. - Parameter:
N/A
- - Notes:
This action is only concerned with outgoing cookies. For
- incoming cookies, use
- crunch-incoming-cookies.
- Use both to disable cookies completely.
- It makes no sense at all to use this action in conjunction
- with the session-cookies-only action,
- since it would prevent the session cookies from being read.
- - Example usage:
-
8.5.9. deanimate-gifs- Typical use:
Stop those annoying, distracting animated GIF images. - Effect:
De-animate GIF animations, i.e. reduce them to their first or last image.
- - Type:
Parameterized. - Parameter:
"last" or "first"
- - Notes:
This will also shrink the images considerably (in bytes, not pixels!). If
- the option "first" is given, the first frame of the animation
- is used as the replacement. If "last" 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).
- 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.
- - Example usage:
-
8.5.10. downgrade-http-version- Typical use:
Work around (very rare) problems with HTTP/1.1 - Effect:
Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0.
- - Type:
Boolean. - Parameter:
N/A
- - Notes:
This is a left-over from the time when Privoxy
- 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.
- - Example usage (section):
{+downgrade-http-version}
-problem-host.example.com |
-
8.5.11. fast-redirects- Typical use:
Fool some click-tracking scripts and speed up indirect links. - Effect:
Detects redirection URLs and redirects the browser without contacting
- the redirection server first.
- - Type:
Parameterized. - Parameter:
- Notes:
- 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:
- "http://www.example.org/click-tracker.cgi?target=http%3a//www.example.net/".
- 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.
- 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:
- 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.
- fast-redirects 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.
- Another failure occurs if the URL contains other parameters after the URL parameter.
- The URL:
- "http://www.example.org/?redirect=http%3a//www.example.net/&foo=bar".
- contains the redirection URL "http://www.example.net/",
- followed by another parameter. fast-redirects doesn't know that
- and will cause a redirect to "http://www.example.net/&foo=bar".
- Depending on the target server configuration, the parameter will be silently ignored
- or lead to a "page not found" error. It is possible to fix these redirected
- requests with filter-client-headers
- but it requires a little effort.
- To detect a redirection URL, fast-redirects only
- looks for the string "http://", either in plain text
- (invalid but often used) or encoded as "http%3a//".
- 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
- fast-redirects is fooled and the request reaches the
- redirection server where it probably gets logged.
- - Example usage:
+fast-redirects{simple-check} |
- +fast-redirects{check-decoded-url} |
-
8.5.12. filter- Typical use:
Get rid of HTML and JavaScript annoyances, banner advertisements (by size), do fun text replacements, etc. - Effect:
All files of text-based type, most notably HTML and JavaScript, to which this
- action applies, are 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
- text/plain MIME type for all files whose type they
- don't know.)
- - Type:
Parameterized. - Parameter:
The name of a filter, as defined in the filter file.
- Filters can be defined in one or more files as defined by the
- filterfile
- option in the config file.
- default.filter is the collection of filters
- supplied by the developers. Locally defined filters should go
- in their own file, such as user.filter.
- When used in its negative form,
- and without parameters, filtering is completely disabled.
- - Notes:
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.
- 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.
- This is very powerful feature, and "rolling your own"
- filters requires a knowledge of regular expressions and HTML.
- The amount of data that can be filtered is limited to the
- buffer-limit
- option in the main config file. The
- default is 4096 KB (4 Megs). Once this limit is exceeded, the buffered
- data, and all pending data, is passed through unfiltered.
- Inadequate 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 -filter sections.
- At this time, Privoxy cannot (yet!) uncompress compressed
- documents. If you want filtering to work on all documents, even those that
- would normally be sent compressed, use the
- prevent-compression
- action in conjunction with filter.
- Filtering can achieve some of the same effects as the
- block
- 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.
- Feedback with suggestions for new or
- improved filters is particularly welcome!
- The below list has only the names and a one-line description of each
- predefined filter. There are more
- verbose explanations of what these filters do in the filter file chapter.
- - Example usage (with filters from the distribution default.filter file).
- See the Predefined Filters section for
- more explanation on each:
- +filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse |
-
- +filter{js-events} # Kill all JS event bindings (Radically destructive! Only for extra nasty sites) |
-
- +filter{html-annoyances} # Get rid of particularly annoying HTML abuse |
-
- +filter{content-cookies} # Kill cookies that come in the HTML or JS content |
-
- +filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups) |
-
- +filter{unsolicited-popups} # Disable only unsolicited pop-up windows |
-
- +filter{all-popups} # Kill all popups in JavaScript and HTML |
-
- +filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective |
-
- +filter{banners-by-size} # Kill banners by size |
-
- +filter{banners-by-link} # Kill banners by their links to known clicktrackers |
-
- +filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking) |
-
- +filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap |
-
- +filter{jumping-windows} # Prevent windows from resizing and moving themselves |
-
- +filter{frameset-borders} # Give frames a border and make them resizable |
-
- +filter{demoronizer} # Fix MS's non-standard use of standard charsets |
-
- +filter{shockwave-flash} # Kill embedded Shockwave Flash objects |
-
- +filter{quicktime-kioskmode} # Make Quicktime movies saveable |
-
- +filter{fun} # Text replacements for subversive browsing fun! |
-
- +filter{crude-parental} # Crude parental filtering (demo only) |
-
- +filter{ie-exploits} # Disable some known Internet Explorer bug exploits |
-
8.5.13. force-text-mode- Typical use:
Force Privoxy to treat a document as if it was in some kind of text format. - Effect:
Declares a document as text, even if the "Content-Type:" isn't detected as such.
- - Type:
Boolean. - Parameter:
N/A
- - Notes:
As explained above,
- Privoxy tries to only filter files that are
- in some kind of text format. The same restrictions apply to
- content-type-overwrite.
- force-text-mode declares a document as text,
- without looking at the "Content-Type:" first.
- Warning | Think twice before activating this action. Filtering binary data
- with regular expressions can cause file damage.
- |
- Example usage:
-
8.5.14. handle-as-empty-document- Typical use:
Mark URLs that should be replaced by empty documents if they get blocked - Effect:
This action alone doesn't do anything noticeable. It just marks URLs.
- If the block action also applies,
- the presence or absence of this mark decides whether an HTML "blocked"
- page, or an empty document will be sent to the client as a substitute for the blocked content.
- The empty document isn't literally empty, but actually contains a single space.
- - Type:
Boolean. - Parameter:
N/A
- - Notes:
Some browsers complain about syntax errors if JavaScript documents
- are blocked with Privoxy's
- default HTML page; this option can be used to silence them.
- The content type for the empty document can be specified with
- content-type-overwrite{},
- but usually this isn't necessary.
- - Example usage:
# Block all documents on example.org that end with ".js",
-# but send an empty document instead of the usual HTML message.
-{+block +handle-as-empty-document}
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Prevent the web server from reading any HTTP cookies from
+ your system
+
+
+ -
+ Effect:
+
+ -
+
+ Deletes any "Cookie:" HTTP
+ headers from client requests.
+
+
+ -
+ Type:
+
+ -
+
+ Boolean.
+
+
+ -
+ Parameter:
+
+ -
+
+ N/A
+
+
+ -
+ Notes:
+
+ -
+
+ This action is only concerned with outgoing HTTP
+ cookies. For incoming HTTP cookies, use crunch-incoming-cookies.
+ Use both to disable HTTP cookies
+ completely.
+
+
+ It makes no
+ sense at all to use this action in conjunction
+ with the session-cookies-only
+ action, since it would prevent the session cookies from
+ being read.
+
+
+ -
+ Example usage:
+
+ -
+
+
+
+
+
+
++crunch-outgoing-cookies
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Stop those annoying, distracting animated GIF images.
+
+
+ -
+ Effect:
+
+ -
+
+ De-animate GIF animations, i.e. reduce them to their first
+ or last image.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized.
+
+
+ -
+ Parameter:
+
+ -
+
+ "last" or "first"
+
+
+ -
+ Notes:
+
+ -
+
+ This will also shrink the images considerably (in bytes,
+ not pixels!). If the option "first" is given, the first frame of the
+ animation is used as the replacement. If "last" 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).
+
+
+ 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.
+
+
+ -
+ Example usage:
+
+ -
+
+
+
+
+
+
++deanimate-gifs{last}
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Work around (very rare) problems with HTTP/1.1
+
+
+ -
+ Effect:
+
+ -
+
+ Downgrades HTTP/1.1 client requests and server replies to
+ HTTP/1.0.
+
+
+ -
+ Type:
+
+ -
+
+ Boolean.
+
+
+ -
+ Parameter:
+
+ -
+
+ N/A
+
+
+ -
+ Notes:
+
+ -
+
+ This is a left-over from the time when Privoxy 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.
+
+
+ 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.
+
+
+ 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
+ Privoxy it should be fixed
+ so the following release works without the work around.
+
+
+ -
+ Example usage (section):
+
+ -
+
+
+
+
+
+
+{+downgrade-http-version}
+problem-host.example.com
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Modify content using a programming language of your choice.
+
+
+ -
+ Effect:
+
+ -
+
+ 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 external filter. By
+ default plain text documents are exempted from filtering,
+ because web servers often use the text/plain MIME type for all files whose
+ type they don't know.)
+
+
+ -
+ Type:
+
+ -
+
+ Multi-value.
+
+
+ -
+ Parameter:
+
+ -
+
+ The name of an external content filter, as defined in the
+ filter file. External
+ filters can be defined in one or more files as defined by
+ the filterfile option in the
+ config file.
+
+
+ When used in its negative form, and without parameters,
+ all
+ filtering with external filters is completely disabled.
+
+
+ -
+ Notes:
+
+ -
+
+ External filters are scripts or programs that can modify
+ the content in case common filters aren't powerful
+ enough. With the exception that this action doesn't use
+ pcrs-based filters, the notes in the filter section
+ apply.
+
+
+
+
+
+ Warning
+ |
+
+
+
+
+ Currently external filters are executed with Privoxy's privileges.
+ Only use external filters you understand and trust.
+
+ |
+
+
+
+
+ This feature is experimental, the syntax
+ may change in the future.
+
+
+ -
+ Example usage:
+
+ -
+
+
+
+
+
+
++external-filter{fancy-filter}
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Fool some click-tracking scripts and speed up indirect
+ links.
+
+
+ -
+ Effect:
+
+ -
+
+ Detects redirection URLs and redirects the browser without
+ contacting the redirection server first.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized.
+
+
+ -
+ Parameter:
+
+ -
+
+
+ -
+ Notes:
+
+ -
+
+ 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: "http://www.example.org/click-tracker.cgi?target=http%3a//www.example.net/".
+
+
+ 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.
+
+
+ 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:
+
+
+ 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. fast-redirects 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.
+
+
+ Another failure occurs if the URL contains other parameters
+ after the URL parameter. The URL: "http://www.example.org/?redirect=http%3a//www.example.net/&foo=bar".
+ contains the redirection URL "http://www.example.net/", followed by
+ another parameter. fast-redirects
+ doesn't know that and will cause a redirect to "http://www.example.net/&foo=bar".
+ Depending on the target server configuration, the parameter
+ will be silently ignored or lead to a "page not found" error. You can prevent this
+ problem by first using the redirect action to
+ remove the last part of the URL, but it requires a little
+ effort.
+
+
+ To detect a redirection URL, fast-redirects only looks for the string
+ "http://", either in plain text
+ (invalid but often used) or encoded as "http%3a//". 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 fast-redirects is fooled and the
+ request reaches the redirection server where it probably
+ gets logged.
+
+
+ -
+ Example usage:
+
+ -
+
+
+
+
+
+
+ { +fast-redirects{simple-check} }
+ one.example.com
+
+ { +fast-redirects{check-decoded-url} }
+ another.example.com/testing
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Get rid of HTML and JavaScript annoyances, banner
+ advertisements (by size), do fun text replacements, add
+ personalized effects, etc.
+
+
+ -
+ Effect:
+
+ -
+
+ 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 text/plain MIME type
+ for all files whose type they don't know.)
+
+
+ -
+ Type:
+
+ -
+
+ Multi-value.
+
+
+ -
+ Parameter:
+
+ -
+
+ The name of a content filter, as defined in the filter file. Filters can be defined
+ in one or more files as defined by the filterfile option in the
+ config file. default.filter is the collection of filters
+ supplied by the developers. Locally defined filters should
+ go in their own file, such as user.filter.
+
+
+ When used in its negative form, and without parameters,
+ all
+ filtering is completely disabled.
+
+
+ -
+ Notes:
+
+ -
+
+ 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.
+
+
+ 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.
+
+
+ "Rolling your own" filters
+ requires a knowledge of "Regular Expressions"
+ and "HTML". This is very
+ powerful feature, and potentially very intrusive. Filters
+ should be used with caution, and where an equivalent "action" is not available.
+
+
+ The amount of data that can be filtered is limited to the
+ buffer-limit option in
+ the main config file. The default
+ is 4096 KB (4 Megs). Once this limit is exceeded, the
+ buffered data, and all pending data, is passed through
+ unfiltered.
+
+
+ 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 -filter exceptions.
+
+
+ Compressed content can't be filtered either, but if Privoxy is compiled with zlib
+ support and a supported compression algorithm is used (gzip
+ or deflate), Privoxy can
+ first decompress the content and then filter it.
+
+
+ If you use a Privoxy
+ 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 prevent-compression
+ action in conjunction with filter.
+
+
+ Content filtering can achieve some of the same effects as
+ the block 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.
+
+
+ Feedback with suggestions for
+ new or improved filters is particularly welcome!
+
+
+ The below list has only the names and a one-line
+ description of each predefined filter. There are more verbose
+ explanations of what these filters do in the filter file chapter.
+
+
+ -
+ Example usage (with filters from the distribution default.filter file). See the Predefined Filters
+ section for more explanation on each:
+
+ -
+
+
+
+
+
+
+
++filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{js-events} # Kill JavaScript event bindings and timers (Radically destructive! Only for extra nasty sites).
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{html-annoyances} # Get rid of particularly annoying HTML abuse.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{content-cookies} # Kill cookies that come in the HTML or JS content.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{refresh-tags} # Kill automatic refresh tags if refresh time is larger than 9 seconds.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{unsolicited-popups} # Disable only unsolicited pop-up windows.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{all-popups} # Kill all popups in JavaScript and HTML.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{banners-by-size} # Kill banners by size.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{banners-by-link} # Kill banners by their links to known clicktrackers.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking).
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{jumping-windows} # Prevent windows from resizing and moving themselves.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{frameset-borders} # Give frames a border and make them resizable.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{iframes} # Removes all detected iframes. Should only be enabled for individual sites.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{demoronizer} # Fix MS's non-standard use of standard charsets.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{shockwave-flash} # Kill embedded Shockwave Flash objects.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{quicktime-kioskmode} # Make Quicktime movies saveable.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{fun} # Text replacements for subversive browsing fun!
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{crude-parental} # Crude parental filtering. Note that this filter doesn't work reliably.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{ie-exploits} # Disable some known Internet Explorer bug exploits.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{site-specifics} # Cure for site-specific problems. Don't apply generally!
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{no-ping} # Removes non-standard ping attributes in <a> and <area> tags.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{google} # CSS-based block for Google text ads. Also removes a width limitation and the toolbar advertisement.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{yahoo} # CSS-based block for Yahoo text ads. Also removes a width limitation.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{msn} # CSS-based block for MSN text ads. Also removes tracking URLs and a width limitation.
+
+ |
+
+
+
+
+
+
+
+
+
+
++filter{blogspot} # Cleans up some Blogspot blogs. Read the fine print before using this.
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Force Privoxy to treat a
+ document as if it was in some kind of text format.
+
+
+ -
+ Effect:
+
+ -
+
+ Declares a document as text, even if the "Content-Type:" isn't detected as such.
+
+
+ -
+ Type:
+
+ -
+
+ Boolean.
+
+
+ -
+ Parameter:
+
+ -
+
+ N/A
+
+
+ -
+ Notes:
+
+ -
+
+ As explained above, Privoxy tries to only filter files
+ that are in some kind of text format. The same restrictions
+ apply to content-type-overwrite.
+ force-text-mode declares a
+ document as text, without looking at the "Content-Type:" first.
+
+
+
+
+
+ Warning
+ |
+
+
+
+
+ Think twice before activating this action.
+ Filtering binary data with regular expressions can
+ cause file damage.
+
+ |
+
+
+
+
+ -
+ Example usage:
+
+ -
+
+
+
+
+
+
++force-text-mode
+
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Change the forwarding settings based on User-Agent or
+ request origin
+
+
+ -
+ Effect:
+
+ -
+
+ Overrules the forward directives in the configuration file.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized.
+
+
+ -
+ Parameter:
+
+ -
+
+ -
+
+ "forward ." to use a direct
+ connection without any additional proxies.
+
+
+ -
+
+ "forward 127.0.0.1:8123" to
+ use the HTTP proxy listening at 127.0.0.1 port 8123.
+
+
+ -
+
+ "forward-socks4a 127.0.0.1:9050
+ ." to use the socks4a proxy listening at
+ 127.0.0.1 port 9050. Replace "forward-socks4a" with "forward-socks4" to use a socks4
+ connection (with local DNS resolution) instead, use
+ "forward-socks5" for socks5
+ connections (with remote DNS resolution).
+
+
+ -
+
+ "forward-socks4a 127.0.0.1:9050
+ proxy.example.org:8000" 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
+ "forward-socks4a" with "forward-socks4" to use a socks4
+ connection (with local DNS resolution) instead, use
+ "forward-socks5" for socks5
+ connections (with remote DNS resolution).
+
+
+ -
+
+ "forward-webserver
+ 127.0.0.1:80" to use the HTTP server listening
+ at 127.0.0.1 port 80 without adjusting the request
+ headers.
+
+
+ This makes it more convenient to use Privoxy to make
+ existing websites available as onion services as well.
+
+
+ Many websites serve content with hardcoded URLs and
+ can't be easily adjusted to change the domain based on
+ the one used by the client.
+
+
+ Putting Privoxy between Tor and the webserver (or an
+ stunnel that forwards to the webserver) allows to
+ rewrite headers and content to make client and server
+ happy at the same time.
+
+
+ Using Privoxy for webservers that are only reachable
+ through onion addresses and whose location is supposed
+ to be secret is not recommended and should not be
+ necessary anyway.
+
+
+
+
+ -
+ Notes:
+
+ -
+
+ This action takes parameters similar to the forward 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.
+
+
+
+
+
+ Warning
+ |
+
+
+
+
+ Please read the description for the forward directives
+ before using this action. Forwarding to the wrong
+ people will reduce your privacy and increase the
+ chances of man-in-the-middle attacks.
+
+
+ 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. Due to design
+ limitations, invalid parameter syntax isn't
+ detected until the action is used the first time.
+
+
+ Use the show-url-info CGI page to verify that
+ your forward settings do what you thought the do.
+
+ |
+
+
+
+
+ -
+ Example usage:
+
+ -
+
+
+
+
+
+
+# Use an ssh tunnel for requests previously tagged as
+# "User-Agent: fetch libfetch/2.0" 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-socks5 10.0.0.2:2222 .} \
+ -hide-if-modified-since \
+ -overwrite-last-modified \
+}
+TAG:^User-Agent: fetch libfetch/2\.0$
+
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Mark URLs that should be replaced by empty documents if they get
+ blocked
+
+
+ -
+ Effect:
+
+ -
+
+ This action alone doesn't do anything noticeable. It just
+ marks URLs. If the block action also
+ applies, the presence or absence of this mark
+ decides whether an HTML "BLOCKED" page, or an empty document will be
+ sent to the client as a substitute for the blocked content.
+ The empty document isn't literally empty,
+ but actually contains a single space.
+
+
+ -
+ Type:
+
+ -
+
+ Boolean.
+
+
+ -
+ Parameter:
+
+ -
+
+ N/A
+
+
+ -
+ Notes:
+
+ -
+
+ Some browsers complain about syntax errors if JavaScript
+ documents are blocked with Privoxy's default HTML page; this
+ option can be used to silence them. And of course this
+ action can also be used to eliminate the Privoxy BLOCKED message in frames.
+
+
+ The content type for the empty document can be specified
+ with content-type-overwrite{},
+ but usually this isn't necessary.
+
+
+ -
+ Example usage:
+
+ -
+
+
+
+
+
+
+# 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$
- |
- 8.5.15. handle-as-image- Typical use:
Mark URLs as belonging to images (so they'll be replaced by imagee if they get blocked) - Effect:
This action alone doesn't do anything noticeable. It just marks URLs as images.
- If the block action also applies,
- the presence or absence of this mark decides whether an HTML "blocked"
- page, or a replacement image (as determined by the set-image-blocker action) will be sent to the
- client as a substitute for the blocked content.
- - Type:
Boolean. - Parameter:
N/A
- - Notes:
The below generic example section is actually part of default.action.
- It marks all URLs with well-known image file name extensions as images and should
- be left intact.
- Users will probably only want to use the handle-as-image action in conjunction with
- block, to block sources of banners, whose URLs don't
- reflect the file type, like in the second example section.
- 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 handle-as-image in this situation will not replace the
- ad frame with an image, but lead to error messages.
- - Example usage (sections):
# Generic image extensions:
+
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Mark URLs as belonging to images (so they'll be replaced by
+ images if they
+ do get blocked, rather than HTML pages)
+
+
+ -
+ Effect:
+
+ -
+
+ This action alone doesn't do anything noticeable. It just
+ marks URLs as images. If the block action also
+ applies, the presence or absence of this mark
+ decides whether an HTML "blocked" page, or a replacement image (as
+ determined by the set-image-blocker
+ action) will be sent to the client as a substitute for the
+ blocked content.
+
+
+ -
+ Type:
+
+ -
+
+ Boolean.
+
+
+ -
+ Parameter:
+
+ -
+
+ N/A
+
+
+ -
+ Notes:
+
+ -
+
+ The below generic example section is actually part of default.action. It marks all URLs
+ with well-known image file name extensions as images and
+ should be left intact.
+
+
+ Users will probably only want to use the handle-as-image
+ action in conjunction with block, to block sources
+ of banners, whose URLs don't reflect the file type, like in
+ the second example section.
+
+
+ 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
+ handle-as-image in this situation
+ will not replace the ad frame with an image, but lead to
+ error messages.
+
+
+ -
+ Example usage (sections):
+
+ -
+
+
+
+
+
+
+# Generic image extensions:
#
{+handle-as-image}
/.*\.(gif|jpg|jpeg|png|bmp|ico)$
@@ -3756,2489 +3700,1762 @@ CLASS="SCREEN"
# These don't look like images, but they're banners and should be
# blocked as images:
#
-{+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 |
- 8.5.16. hide-accept-language- Typical use:
Pretend to use different language settings. - Effect:
Deletes or replaces the "Accept-Language:" HTTP header in client requests.
- - Type:
Parameterized. - Parameter:
Keyword: "block", or any user defined value.
- - Notes:
Faking the browser's language settings can be useful to make a
- foreign User-Agent set with
- hide-user-agent
- more believable.
- However some sites with content in different languages check the
- "Accept-Language:" to decide which one to take by default.
- Sometimes it isn't possible to later switch to another language without
- changing the "Accept-Language:" header first.
- Therefore it's a good idea to either only change the
- "Accept-Language:" header to languages you understand,
- or to languages that aren't wide spread.
- Before setting the "Accept-Language:" 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.
- - Example usage (section):
# Pretend to use Canadian language settings.
+{+block{Nasty banners.} +handle-as-image}
+nasty-banner-server.example.com/junk.cgi\?output=trash
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Pretend to use different language settings.
+
+
+ -
+ Effect:
+
+ -
+
+ Deletes or replaces the "Accept-Language:" HTTP header in client
+ requests.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized.
+
+
+ -
+ Parameter:
+
+ -
+
+ Keyword: "block", or any user
+ defined value.
+
+
+ -
+ Notes:
+
+ -
+
+ Faking the browser's language settings can be useful to
+ make a foreign User-Agent set with hide-user-agent
+ more believable.
+
+
+ However some sites with content in different languages
+ check the "Accept-Language:" to
+ decide which one to take by default. Sometimes it isn't
+ possible to later switch to another language without
+ changing the "Accept-Language:"
+ header first.
+
+
+ Therefore it's a good idea to either only change the "Accept-Language:" header to languages
+ you understand, or to languages that aren't wide spread.
+
+
+ Before setting the "Accept-Language:" 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.
+
+
+ -
+ Example usage (section):
+
+ -
+
+
+
+
+
+
+# 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} \
}
-/ |
- 8.5.17. hide-content-disposition- Typical use:
Prevent download menus for content you prefer to view inside the browser. - Effect:
Deletes or replaces the "Content-Disposition:" HTTP header set by some servers.
- - Type:
Parameterized. - Parameter:
Keyword: "block", or any user defined value.
- - Notes:
Some servers set the "Content-Disposition:" HTTP header for
- documents they assume you want to save locally before viewing them.
- The "Content-Disposition:" header contains the file name
- the browser is supposed to use by default.
- In most browsers that understand this header, it makes it impossible to
- just view the document, without downloading it first,
- even if it's just a simple text file or an image.
- Removing the "Content-Disposition:" header helps
- to prevent this annoyance, but some browsers additionally check the
- "Content-Type:" 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.
- 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.
- - Example usage:
# Disarm the download link in Sourceforge's patch tracker
-{-filter\
-+content-type-overwrite {text/plain}\
-+hide-content-disposition {block} }
-.sourceforge.net/tracker/download.php |
-
8.5.18. hide-if-modified-since- Typical use:
Prevent yet another way to track the user's steps between sessions. - Effect:
Deletes the "If-Modified-Since:" HTTP client header or modifies its value.
- - Type:
Parameterized. - Parameter:
Keyword: "block", or a user defined value that specifies a range of hours.
- - Notes:
Removing this header is useful for filter testing, where you want to force a real
- reload instead of getting status code "304", which would cause the
- browser to use a cached copy of the page.
- Instead of removing the header, hide-if-modified-since can
- also add or substract a random amount of time to/from the headers value.
- You specify a range of hours were the random factor should be chosen from and
- Privoxy does the rest. A negative value means
- subtracting, a positive value adding.
- Randomizing the value of the "If-Modified-Since:" makes
- sure it isn't used as a cookie replacement, but you will run into
- caching problems if the random range is too high.
- It is a good idea to only use a small negative value and let
- overwrite-last-modified
- handle the greater changes.
- It is also recommended to use this action together with
- crunch-if-none-match.
- - Example usage (section):
# Let the browser revalidate without being tracked across sessions
-{+hide-if-modified-since {-1}\
-+overwrite-last-modified {randomize}\
-+crunch-if-none-match}
-/ |
-
8.5.19. hide-forwarded-for-headers- Typical use:
Improve privacy by hiding the true source of the request - Effect:
Deletes any existing "X-Forwarded-for:" HTTP header from client requests,
- and prevents adding a new one.
- - Type:
Boolean. - Parameter:
N/A
- - Notes:
It is fairly safe to leave this on.
- This action is scheduled for improvement: It should be able to generate forged
- "X-Forwarded-for:" 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.
- - Example usage:
+hide-forwarded-for-headers |
-
8.5.20. hide-from-header- Typical use:
Keep your (old and ill) browser from telling web servers your email address - Effect:
Deletes any existing "From:" HTTP header, or replaces it with the
- specified string.
- - Type:
Parameterized. - Parameter:
Keyword: "block", or any user defined value.
- - Notes:
The keyword "block" will completely remove the header
- (not to be confused with the block
- action).
- 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.
- This action is rarely needed, as modern web browsers don't send
- "From:" headers anymore.
- - Example usage:
or
- +hide-from-header{spam-me-senseless@sittingduck.example.com} |
-
8.5.21. hide-referrer- Typical use:
Conceal which link you followed to get to a particular site - Effect:
Deletes the "Referer:" (sic) HTTP header from the client request,
- or replaces it with a forged one.
- - Type:
Parameterized. - Parameter:
"conditional-block" to delete the header completely if the host has changed. "block" to delete the header unconditionally. "forge" to pretend to be coming from the homepage of the server we are talking to. Any other string to set a user defined referrer.
- Notes:
conditional-block 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.
- Leaving the referrer unmodified for requests on the same host
- allows the server owner to see the visitor's "click path",
- 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.
- 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 valuable content from being
- embedded or linked to elsewhere.
- Both conditional-block and forge
- 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.
-
- hide-referer is an alternate spelling of
- hide-referrer and the two can be can be freely
- substituted with each other. ("referrer" is the
- correct English spelling, however the HTTP specification has a bug - it
- requires it to be spelled as "referer".)
- - Example usage:
or
- +hide-referrer{http://www.yahoo.com/} |
-
8.5.22. hide-user-agent- Typical use:
Conceal your type of browser and client operating system - Effect:
Replaces the value of the "User-Agent:" HTTP header
- in client requests with the specified value.
- - Type:
Parameterized. - Parameter:
Any user-defined string.
- - Notes:
Warning | 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 NOT the right thing to do: good web sites
- work browser-independently).
-
- |
Using this action in multi-user setups or wherever different types of
- browsers will access the same Privoxy is
- not recommended. 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 Mozilla enter, yet forging to a
- Netscape 6.1 user-agent works just fine.
- (Must be just a silly MS goof, I'm sure :-).
- This action is scheduled for improvement.
- - Example usage:
+hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)} |
-
8.5.23. inspect-jpegs- Typical use:
To protect against the MS buffer over-run in JPEG processing - Effect:
To protect against a known exploit
- - Type:
Boolean. - Parameter:
N/A
- - Notes:
See Microsoft Security Bulletin MS04-028. JPEG images are one of the most
- common image types found across the Internet. The exploit as described can
- allow execution of code on the target system, giving an attacker access
- to the system in question by merely planting an altered JPEG image, which
- would have no obvious indications of what lurks inside. This action
- prevents unwanted intrusion.
- - Example usage:
8.5.24. kill-popups- Typical use:
Eliminate those annoying pop-up windows (deprecated) - Effect:
While loading the document, replace JavaScript code that opens
- pop-up windows with (syntactically neutral) dummy code on the fly.
- - Type:
Boolean. - Parameter:
N/A
- - Notes:
This action is basically a built-in, hardwired special-purpose filter
- action, but there are important differences: For kill-popups,
- the document need not be buffered, so it can be incrementally rendered while
- downloading. But kill-popups doesn't catch as many pop-ups as
- filter{all-popups}
- does and is not as smart as filter{unsolicited-popups}
- is.
- 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 filter action,
- since as soon as one filter applies,
- the whole document needs to be buffered anyway, which destroys the advantage of
- the kill-popups action over its filter equivalent.
- Killing all pop-ups unconditionally is problematic. Many shops and banks rely on
- pop-ups to display forms, shopping carts etc, and the filter{unsolicited-popups}
- does a fairly good job of catching only the unwanted ones.
- If the only kind of pop-ups that you want to kill are exit consoles (those
- really nasty windows that appear when you close an other
- one), you might want to use
- filter{js-annoyances}
- instead.
- - Example usage:
8.5.25. limit-connect- Typical use:
Prevent abuse of Privoxy as a TCP proxy relay or disable SSL for untrusted sites - Effect:
Specifies to which ports HTTP CONNECT requests are allowable.
- - Type:
Parameterized. - Parameter:
A comma-separated list of ports or port ranges (the latter using dashes, with the minimum
- defaulting to 0 and the maximum to 65K).
- - Notes:
By default, i.e. if no limit-connect action applies,
- Privoxy only allows HTTP CONNECT
- requests to port 443 (the standard, secure HTTPS port). Use
- limit-connect if more fine-grained control is desired
- for some or all destinations.
- The CONNECT methods exists in HTTP to allow access to secure websites
- ("https://" 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.
- Privoxy relays HTTPS traffic without seeing
- the decoded content. Websites can leverage this limitation to circumvent Privoxy's
- filters. By specifying an invalid port range you can disable HTTPS entirely.
- If you plan to disable SSL by default, consider enabling
- treat-forbidden-connects-like-blocks
- as well, to be able to quickly create exceptions.
- - Example usages:
+limit-connect{443} # This is the default and need not be specified.
+/
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Prevent download menus for content you prefer to view
+ inside the browser.
+
+
+ -
+ Effect:
+
+ -
+
+ Deletes or replaces the "Content-Disposition:" HTTP header set by
+ some servers.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized.
+
+
+ -
+ Parameter:
+
+ -
+
+ Keyword: "block", or any user
+ defined value.
+
+
+ -
+ Notes:
+
+ -
+
+ Some servers set the "Content-Disposition:" HTTP header for
+ documents they assume you want to save locally before
+ viewing them. The "Content-Disposition:" header contains the
+ file name the browser is supposed to use by default.
+
+
+ In most browsers that understand this header, it makes it
+ impossible to just view the document, without
+ downloading it first, even if it's just a simple text file
+ or an image.
+
+
+ Removing the "Content-Disposition:" header helps to
+ prevent this annoyance, but some browsers additionally
+ check the "Content-Type:"
+ 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.
+
+
+ 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.
+
+
+ This action will probably be removed in the future, use
+ server-header filters instead.
+
+
+ -
+ Example usage:
+
+ -
+
+
+
+
+
+
+# Disarm the download link in Sourceforge's patch tracker
+{ -filter \
+ +content-type-overwrite{text/plain}\
+ +hide-content-disposition{block} }
+ .sourceforge.net/tracker/download\.php
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Prevent yet another way to track the user's steps between
+ sessions.
+
+
+ -
+ Effect:
+
+ -
+
+ Deletes the "If-Modified-Since:"
+ HTTP client header or modifies its value.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized.
+
+
+ -
+ Parameter:
+
+ -
+
+ Keyword: "block", or a user
+ defined value that specifies a range of hours.
+
+
+ -
+ Notes:
+
+ -
+
+ Removing this header is useful for filter testing, where
+ you want to force a real reload instead of getting status
+ code "304", which would cause
+ the browser to use a cached copy of the page.
+
+
+ Instead of removing the header, hide-if-modified-since 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 Privoxy does the rest. A negative
+ value means subtracting, a positive value adding.
+
+
+ Randomizing the value of the "If-Modified-Since:" 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.
+
+
+ It is a good idea to only use a small negative value and
+ let overwrite-last-modified
+ handle the greater changes.
+
+
+ It is also recommended to use this action together with crunch-if-none-match,
+ otherwise it's more or less pointless.
+
+
+ -
+ Example usage (section):
+
+ -
+
+
+
+
+
+
+# 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}
+/
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Keep your (old and ill) browser from telling web servers
+ your email address
+
+
+ -
+ Effect:
+
+ -
+
+ Deletes any existing "From:"
+ HTTP header, or replaces it with the specified string.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized.
+
+
+ -
+ Parameter:
+
+ -
+
+ Keyword: "block", or any user
+ defined value.
+
+
+ -
+ Notes:
+
+ -
+
+ The keyword "block" will
+ completely remove the header (not to be confused with the
+ block action).
+
+
+ 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.
+
+
+ This action is rarely needed, as modern web browsers don't
+ send "From:" headers anymore.
+
+
+ -
+ Example usage:
+
+ -
+
+
+
+
+
+
++hide-from-header{block}
+
+ |
+
+
+ or
+
+
+
+
++hide-from-header{spam-me-senseless@sittingduck.example.com}
+
+ |
+
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Conceal which link you followed to get to a particular site
+
+
+ -
+ Effect:
+
+ -
+
+ Deletes the "Referer:" (sic)
+ HTTP header from the client request, or replaces it with a
+ forged one.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized.
+
+
+ -
+ Parameter:
+
+ -
+
+ -
+
+ "conditional-block" to
+ delete the header completely if the host has changed.
+
+
+ -
+
+ "conditional-forge" to forge
+ the header if the host has changed.
+
+
+ -
+
+ "block" to delete the header
+ unconditionally.
+
+
+ -
+
+ "forge" to pretend to be
+ coming from the homepage of the server we are talking
+ to.
+
+
+ -
+
+ Any other string to set a user defined referrer.
+
+
+
+
+ -
+ Notes:
+
+ -
+
+ conditional-block 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.
+
+
+ Leaving the referrer unmodified for requests on the same
+ host allows the server owner to see the visitor's "click path", 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.
+
+
+ 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.
+
+
+ Both conditional-block and forge 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.
+
+
+ hide-referer is an alternate
+ spelling of hide-referrer and the
+ two can be can be freely substituted with each other.
+ ("referrer" is the correct
+ English spelling, however the HTTP specification has a bug
+ - it requires it to be spelled as "referer".)
+
+
+ -
+ Example usage:
+
+ -
+
+
+
+
+
+
++hide-referrer{forge}
+
+ |
+
+
+ or
+
+
+
+
++hide-referrer{http://www.yahoo.com/}
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Try to conceal your type of browser and client operating
+ system
+
+
+ -
+ Effect:
+
+ -
+
+ Replaces the value of the "User-Agent:" HTTP header in client requests
+ with the specified value.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized.
+
+
+ -
+ Parameter:
+
+ -
+
+ Any user-defined string.
+
+
+ -
+ Notes:
+
+ -
+
+
+
+
+ Warning
+ |
+
+
+
+
+ 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 NOT the right thing to do:
+ good web sites work browser-independently).
+
+ |
+
+
+
+
+ Using this action in multi-user setups or wherever
+ different types of browsers will access the same Privoxy is not recommended.
+ 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).
+
+
+ More information on known user-agent strings can be found
+ at http://www.user-agents.org/ and http://en.wikipedia.org/wiki/User_agent.
+
+
+ -
+ Example usage:
+
+ -
+
+
+
+
+
+
++hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Prevent abuse of Privoxy
+ as a TCP proxy relay or disable SSL for untrusted sites
+
+
+ -
+ Effect:
+
+ -
+
+ Specifies to which ports HTTP CONNECT requests are
+ allowable.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized.
+
+
+ -
+ Parameter:
+
+ -
+
+ A comma-separated list of ports or port ranges (the latter
+ using dashes, with the minimum defaulting to 0 and the
+ maximum to 65K).
+
+
+ -
+ Notes:
+
+ -
+
+ By default, i.e. if no limit-connect action applies, Privoxy allows HTTP CONNECT requests
+ to all ports. Use limit-connect if
+ fine-grained control is desired for some or all
+ destinations.
+
+
+ The CONNECT methods exists in HTTP to allow access to
+ secure websites ("https://"
+ 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.
+
+
+ Privoxy relays HTTPS
+ traffic without seeing the decoded content. Websites can
+ leverage this limitation to circumvent Privoxy's filters. By specifying an
+ invalid port range you can disable HTTPS entirely.
+
+
+ -
+ Example usages:
+
+ -
+
+
+
+
+
+
++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 traffic is allowed |
- 8.5.26. prevent-compression- Typical use:
Ensure that servers send the content uncompressed, so it can be
- passed through filters.
- - Effect:
Removes the Accept-Encoding header which can be used to ask for compressed transfer.
- - Type:
Boolean. - Parameter:
N/A
- - Notes:
More and more websites send their content compressed by default, which
- is generally a good idea and saves bandwidth. But for the filter, deanimate-gifs
- and kill-popups actions to work,
- Privoxy needs access to the uncompressed data.
- Unfortunately, Privoxy 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.
- This will slow down transfers from those websites, though. If you use any of the above-mentioned
- actions, you will typically want to use prevent-compression in conjunction
- with them.
- Note that some (rare) ill-configured sites don't handle requests for uncompressed
- documents correctly (they send an empty document body). If you use prevent-compression
- per default, you'll have to add exceptions for those sites. See the example for how to do that.
- - Example usage (sections):
# Set default:
++limit-connect{,} # No HTTPS/SSL traffic is allowed
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Limit the lifetime of HTTP cookies to a couple of minutes
+ or hours.
+
+
+ -
+ Effect:
+
+ -
+
+ Overwrites the expires field in Set-Cookie server headers
+ if it's above the specified limit.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized.
+
+
+ -
+ Parameter:
+
+ -
+
+ The lifetime limit in minutes, or 0.
+
+
+ -
+ Notes:
+
+ -
+
+ 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.
+
+
+ Cookies with a lifetime below the limit are not modified.
+ The lifetime of session cookies is set to the specified
+ limit.
+
+
+ The effect of this action depends on the server.
+
+
+ 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.
+
+
+ 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.
+
+
+ If the parameter is "0", this
+ action behaves like session-cookies-only.
+
+
+ -
+ Example usages:
+
+ -
+
+
+
+
+
+
++limit-cookie-lifetime{60}
+
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Ensure that servers send the content uncompressed, so it
+ can be passed through filters.
+
+
+ -
+ Effect:
+
+ -
+
+ Removes the Accept-Encoding header which can be used to ask
+ for compressed transfer.
+
+
+ -
+ Type:
+
+ -
+
+ Boolean.
+
+
+ -
+ Parameter:
+
+ -
+
+ N/A
+
+
+ -
+ Notes:
+
+ -
+
+ More and more websites send their content compressed by
+ default, which is generally a good idea and saves
+ bandwidth. But the filter and deanimate-gifs
+ actions need access to the uncompressed data.
+
+
+ When compiled with zlib support (available since Privoxy 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
+ Privoxy 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.
+
+
+ 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.
+
+
+ Not using compression will therefore slow down the
+ transfer, and you should only enable this action if you
+ really need it. As of Privoxy 3.0.7 it's disabled in all
+ predefined action settings.
+
+
+ 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 prevent-compression per
+ default, you might want to add exceptions for those sites.
+ See the example for how to do that.
+
+
+ -
+ Example usage (sections):
+
+ -
+
+
+
+
+
+
+# Selectively turn off compression, and enable a filter
+#
+{ +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
+
+# Then maybe make exceptions for broken sites:
#
-{+prevent-compression}
-/ # Match all sites
+{ -prevent-compression }
+.compusa.com/
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Prevent yet another way to track the user's steps between
+ sessions.
+
+
+ -
+ Effect:
+
+ -
+
+ Deletes the "Last-Modified:"
+ HTTP server header or modifies its value.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized.
+
+
+ -
+ Parameter:
+
+ -
+
+ One of the keywords: "block",
+ "reset-to-request-time" and
+ "randomize"
+
+
+ -
+ Notes:
+
+ -
+
+ Removing the "Last-Modified:"
+ header is useful for filter testing, where you want to
+ force a real reload instead of getting status code "304", which would cause the browser
+ to reuse the old version of the page.
+
+
+ The "randomize" option
+ overwrites the value of the "Last-Modified:" 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 "Last-Modified:"
+ header to track visits without using cookies. "Randomize" makes it impossible and the
+ browser can still revalidate cached documents.
+
+
+ "reset-to-request-time"
+ overwrites the value of the "Last-Modified:" header with the current
+ time. You could use this option together with hide-if-modified-since
+ to further customize your random range.
+
+
+ The preferred parameter here is "randomize". It is safe to use, as long as
+ the time settings are more or less correct. If the server
+ sets the "Last-Modified:" 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 hided-if-modified-since,
+ just to be sure.
+
+
+ It is also recommended to use this action together with crunch-if-none-match.
+
+
+ -
+ Example usage:
+
+ -
+
+
+
+
+
+
+# Let the browser revalidate without being tracked across sessions
+{ +hide-if-modified-since{-60} \
+ +overwrite-last-modified{randomize} \
+ +crunch-if-none-match}
+/
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Redirect requests to other sites.
+
+
+ -
+ Effect:
+
+ -
+
+ Convinces the browser that the requested document has been
+ moved to another location and the browser should get it
+ from there.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized
+
+
+ -
+ Parameter:
+
+ -
+
+ An absolute URL or a single pcrs command.
+
+
+ -
+ Notes:
+
+ -
+
+ 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.
+
+
+ The syntax for pcrs commands is documented in the filter file section.
+
+
+ Requests can't be blocked and redirected at the same time,
+ applying this action together with block is a
+ configuration error. Currently the request is blocked and
+ an error message logged, the behavior may change in the
+ future and result in Privoxy rejecting the action file.
+
+
+ This action can be combined with fast-redirects{check-decoded-url}
+ to redirect to a decoded version of a rewritten URL.
+
+
+ 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.
+
+
+ In case of problems with your redirects, or simply to watch
+ them working, enable debug
+ 128.
+
+
+ -
+ Example usages:
+
+ -
+
+
+
+
+
+
+# Replace example.com's style sheet with another one
+{ +redirect{http://localhost/css-replacements/example.com.css} }
+ example.com/stylesheet\.css
-# Make exceptions for ill sites:
+# Create a short, easy to remember nickname for a favorite site
+# (relies on the browser to accept and forward invalid URLs to Privoxy)
+{ +redirect{https://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 http://example.com/&bla=fasel&toChange=foo (and any other value but "bar")
+# to http://example.com/&bla=fasel&toChange=bar
#
-{-prevent-compression}
-www.debianhelp.org
-www.pclinuxonline.com |
- 8.5.27. overwrite-last-modified- Typical use:
Prevent yet another way to track the user's steps between sessions. - Effect:
Deletes the "Last-Modified:" HTTP server header or modifies its value.
- - Type:
Parameterized. - Parameter:
One of the keywords: "block", "reset-to-request-time"
- and "randomize"
- - Notes:
Removing the "Last-Modified:" header is useful for filter
- testing, where you want to force a real reload instead of getting status
- code "304", which would cause the browser to reuse the old
- version of the page.
- The "randomize" option overwrites the value of the
- "Last-Modified:" 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 "Last-Modified:"
- header to track visits without using cookies. "Randomize"
- makes it impossible and the browser can still revalidate cached documents.
- "reset-to-request-time" overwrites the value of the
- "Last-Modified:" header with the current time. You could use
- this option together with
- hided-if-modified-since
- to further customize your random range.
- The preferred parameter here is "randomize". It is safe
- to use, as long as the time settings are more or less correct.
- If the server sets the "Last-Modified:" 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
- hided-if-modified-since,
- just to be sure.
- It is also recommended to use this action together with
- crunch-if-none-match.
- - Example usage:
# Let the browser revalidate without being tracked across sessions
-{+hide-if-modified-since {-1}\
-+overwrite-last-modified {randomize}\
-+crunch-if-none-match}
-/ |
-
8.5.28. redirect- Typical use:
Redirect requests to other sites.
- - Effect:
Convinces the browser that the requested document has been moved
- to another location and the browser should get it from there.
- - Type:
Parameterized - Parameter:
Any URL.
- - Notes:
This action is useful to replace whole documents with your own
- ones. For that to work, they have to be available on another server.
- You can do the same by combining the actions
- block,
- handle-as-image and
- set-image-blocker{URL}.
- It doesn't sound right for non-image documents, and that's why this action
- was created.
- This action will be ignored if you use it together with
- block.
- - Example usage:
# Replace example.com's style sheet with another one
-{+redirect{http://localhost/css-replacements/example.com.css}}
-example.com/stylesheet.css |
-
8.5.29. send-vanilla-wafer- Typical use:
Feed log analysis scripts with useless data.
- - Effect:
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.
- - Type:
Boolean. - Parameter:
N/A
- - Notes:
The vanilla wafer is a (relatively) unique header and could conceivably be used to track you.
- This action is rarely used and not enabled in the default configuration.
- - Example usage:
-
8.5.30. send-wafer- Typical use:
Send custom cookies or feed log analysis scripts with even more useless data.
- - Effect:
Sends a custom, user-defined cookie with each request.
- - Type:
Multi-value. - Parameter:
A string of the form "name=value".
- - Notes:
Being multi-valued, multiple instances of this action can apply to the same request,
- resulting in multiple cookies being sent.
- This action is rarely used and not enabled in the default configuration.
- - Example usage (section):
{+send-wafer{UsingPrivoxy=true}}
-my-internal-testing-server.void |
-
8.5.31. session-cookies-only- Typical use:
Allow only temporary "session" cookies (for the current
- browser session only).
- - Effect:
Deletes the "expires" field from "Set-Cookie:"
- server headers. Most browsers will not store such cookies permanently and
- forget them in between sessions.
- - Type:
Boolean. - Parameter:
N/A
- - Notes:
This is less strict than crunch-incoming-cookies /
- crunch-outgoing-cookies and allows you to browse
- websites that insist or rely on setting cookies, without compromising your privacy too badly.
- Most browsers will not permanently store cookies that have been processed by
- session-cookies-only 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.
- It makes no sense at all to use session-cookies-only
- together with crunch-incoming-cookies or
- crunch-outgoing-cookies. If you do, cookies
- will be plainly killed.
- Note that it is up to the browser how it handles such cookies without an "expires"
- field. If you use an exotic browser, you might want to try it out to be sure.
- This setting also has no effect on cookies that may have been stored
- previously by the browser before starting Privoxy.
- These would have to be removed manually.
- Privoxy also uses
- the content-cookies filter
- to block some types of cookies. Content cookies are not effected by
- session-cookies-only.
- - Example usage:
-
8.5.32. set-image-blocker- Typical use:
Choose the replacement for blocked images - Effect:
This action alone doesn't do anything noticeable. If both
- block and handle-as-image also
- apply, i.e. if the request is to be blocked as an image,
- then the parameter of this action decides what will be
- sent as a replacement.
- - Type:
Parameterized. - Parameter:
"pattern" to send a built-in checkerboard pattern image. The image is visually
- decent, scales very well, and makes it obvious where banners were busted.
- "blank" to send a built-in transparent image. This makes banners disappear
- completely, but makes it hard to detect where Privoxy has blocked
- images on a given page and complicates troubleshooting if Privoxy
- has blocked innocent images, like navigation icons.
- "target-url" to
- send a redirect to target-url. You can redirect
- to any image anywhere, even in your local filesystem via "file:///" URL.
- (But note that not all browsers support redirecting to a local file system).
- A good application of redirects is to use special Privoxy-built-in
- URLs, which send the built-in images, as target-url.
- This has the same visual effect as specifying "blank" or "pattern" in
- the first place, but enables your browser to cache the replacement image, instead of requesting
- it over and over again.
-
- Notes:
The URLs for the built-in images are "http://config.privoxy.org/send-banner?type=type", where type is
- either "blank" or "pattern".
- There is a third (advanced) type, called "auto". It is NOT to be
- used in set-image-blocker, but meant for use from filters.
- Auto will select the type of image that would have applied to the referring page, had it been an image.
- - Example usage:
Built-in pattern:
- +set-image-blocker{pattern} |
- Redirect to the BSD devil:
- +set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif} |
- Redirect to the built-in pattern for better caching:
- +set-image-blocker{http://config.privoxy.org/send-banner?type=pattern} |
-
8.5.33. treat-forbidden-connects-like-blocks- Typical use:
Block forbidden connects with an easy to find error message. - Effect:
If this action is enabled, Privoxy no longer
- makes a difference between forbidden connects and ordinary blocks.
- - Type:
Boolean - Parameter:
N/A - Notes:
By default Privoxy answers
- forbidden "Connect" requests
- with a short error message inside the headers. If the browser doesn't display
- headers (most don't), you just see an empty page.
- With this action enabled, Privoxy displays
- the message that is used for ordinary blocks instead. If you decide
- to make an exception for the page in question, you can do so by
- following the "See why" link.
- For "Connect" requests the clients tell
- Privoxy which host they are interested
- in, but not which document they plan to get later. As a result, the
- "Go there anyway" link becomes rather useless:
- it lets the client request the home page of the forbidden host
- through unencrypted HTTP, still using the port of the last request.
- If you previously configured Privoxy to do the
- request through a SSL tunnel, everything will work. Most likely you haven't
- and the server will responds with an error message because it is expecting
- HTTPS.
- - Example usage:
+treat-forbidden-connects-like-blocks |
-
8.5.34. Summary 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 Appendix for a brief example on troubleshooting
- actions. 8.6. Aliases Custom "actions", known to Privoxy
- as "aliases", 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,
- "=",
- "{" and "}", but we strongly
- recommend that you only use "a" to "z",
- "0" to "9", "+", and "-".
- Alias names are not case sensitive, and are not required to start with a
- "+" or "-" sign, since they are merely textually
- expanded. Aliases can be used throughout the actions file, but they must be
- defined in a special section at the top of the file!
- 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. 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
- "shop", you can later change your policy on shops in
- one place, and your changes will take effect everywhere
- in the actions file where the "shop" alias is used. Calling aliases
- by their purpose also makes your actions files more readable. Currently, there is one big drawback to using aliases, though:
- Privoxy'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 Privoxy. Now let's define some aliases... # Useful custom aliases we can use later.
+# The URL pattern makes sure that the following request isn't redirected again.
+{+redirect{s@toChange=[^&]+@toChange=bar@}}
+example.com/.*toChange=(?!bar)
+
+# Add a shortcut to look up illumos bugs
+{+redirect{s@^http://i([0-9]+)/.*@https://www.illumos.org/issues/$1@}}
+# Redirected URL = http://i4974/
+# Redirect Destination = https://www.illumos.org/issues/4974
+i[0-9][0-9][0-9][0-9]*/
+
+# Redirect remote requests for this manual
+# to the local version delivered by Privoxy
+{+redirect{s@^http://www@http://config@}}
+www.privoxy.org/user-manual/
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Rewrite or remove single server headers.
+
+
+ -
+ Effect:
+
+ -
+
+ All server headers to which this action applies are
+ filtered on-the-fly through the specified regular
+ expression based substitutions.
+
+
+ -
+ Type:
+
+ -
+
+ Multi-value.
+
+
+ -
+ Parameter:
+
+ -
+
+ The name of a server-header filter, as defined in one of
+ the filter files.
+
+
+ -
+ Notes:
+
+ -
+
+ 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.
+
+
+ Server-header filters are executed after the other header
+ actions have finished and use their output as input.
+
+
+ Please refer to the filter file
+ chapter to learn which server-header filters are
+ available by default, and how to create your own.
+
+
+ -
+ Example usage (section):
+
+ -
+
+
+
+
+
+
+{+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
+
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Enable or disable filters based on the Content-Type header.
+
+
+ -
+ Effect:
+
+ -
+
+ 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.
+
+
+ -
+ Type:
+
+ -
+
+ Multi-value.
+
+
+ -
+ Parameter:
+
+ -
+
+ The name of a server-header tagger, as defined in one of
+ the filter files.
+
+
+ -
+ Notes:
+
+ -
+
+ Server-header taggers are applied to each header on its
+ own, and as the header isn't modified, each tagger "sees" the original.
+
+
+ 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 (redirect and block).
+
+
+ Obviously crunching based on tags created by server-header
+ taggers doesn't prevent the request from showing up in the
+ server's log file.
+
+
+ -
+ Example usage (section):
+
+ -
+
+
+
+
+
+
+# Tag every request with the content type declared by the server
+{+server-header-tagger{content-type}}
+/
+
+# If the response has a tag starting with 'image/' enable an external
+# filter that only applies to images.
+#
+# Note that the filter is not available by default, it's just a
+# silly example.
+{+external-filter{rotate-image} +force-text-mode}
+TAG:^image/
+
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Allow only temporary "session"
+ cookies (for the current browser session only).
+
+
+ -
+ Effect:
+
+ -
+
+ Deletes the "expires" field from
+ "Set-Cookie:" server headers.
+ Most browsers will not store such cookies permanently and
+ forget them in between sessions.
+
+
+ -
+ Type:
+
+ -
+
+ Boolean.
+
+
+ -
+ Parameter:
+
+ -
+
+ N/A
+
+
+ -
+ Notes:
+
+ -
+
+ This is less strict than crunch-incoming-cookies
+ / crunch-outgoing-cookies
+ and allows you to browse websites that insist or rely on
+ setting cookies, without compromising your privacy too
+ badly.
+
+
+ Most browsers will not permanently store cookies that have
+ been processed by session-cookies-only 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.
+
+
+ It makes no
+ sense at all to use session-cookies-only together with crunch-incoming-cookies
+ or crunch-outgoing-cookies.
+ If you do, cookies will be plainly killed.
+
+
+ Note that it is up to the browser how it handles such
+ cookies without an "expires"
+ field. If you use an exotic browser, you might want to try
+ it out to be sure.
+
+
+ This setting also has no effect on cookies that may have
+ been stored previously by the browser before starting Privoxy. These would have to be
+ removed manually.
+
+
+ Privoxy also uses the content-cookies
+ filter to block some types of cookies. Content cookies
+ are not effected by session-cookies-only.
+
+
+ -
+ Example usage:
+
+ -
+
+
+
+
+
+
++session-cookies-only
+
+ |
+
+
+
+
+
+
+
+
+
+
+ -
+ Typical use:
+
+ -
+
+ Choose the replacement for blocked images
+
+
+ -
+ Effect:
+
+ -
+
+ This action alone doesn't do anything noticeable. If both block and handle-as-image
+ also
+ apply, i.e. if the request is to be blocked as an image,
+ then
+ the parameter of this action decides what will be sent as a
+ replacement.
+
+
+ -
+ Type:
+
+ -
+
+ Parameterized.
+
+
+ -
+ Parameter:
+
+ -
+
+ -
+
+ "pattern" to send a built-in
+ checkerboard pattern image. The image is visually
+ decent, scales very well, and makes it obvious where
+ banners were busted.
+
+
+ -
+
+ "blank" to send a built-in
+ transparent image. This makes banners disappear
+ completely, but makes it hard to detect where Privoxy has blocked images
+ on a given page and complicates troubleshooting if
+ Privoxy has blocked
+ innocent images, like navigation icons.
+
+
+ -
+
+ "target-url" to send a
+ redirect to target-url. You can redirect
+ to any image anywhere, even in your local filesystem
+ via "file:///" URL. (But
+ note that not all browsers support redirecting to a
+ local file system).
+
+
+ A good application of redirects is to use special Privoxy-built-in URLs, which
+ send the built-in images, as target-url. This has the same
+ visual effect as specifying "blank" or "pattern" in the first place, but
+ enables your browser to cache the replacement image,
+ instead of requesting it over and over again.
+
+
+
+
+ -
+ Notes:
+
+ -
+
+ The URLs for the built-in images are "http://config.privoxy.org/send-banner?type=type", where type is either "blank" or "pattern".
+
+
+ There is a third (advanced) type, called "auto". It is NOT to be used in set-image-blocker, but meant for use from filters. Auto will select the
+ type of image that would have applied to the referring
+ page, had it been an image.
+
+
+ -
+ Example usage:
+
+ -
+
+ Built-in pattern:
+
+
+
+
+
+
+
++set-image-blocker{pattern}
+
+ |
+
+
+
+
+ Redirect to the BSD daemon:
+
+
+
+
+
+
+
++set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}
+
+ |
+
+
+
+
+ Redirect to the built-in pattern for better caching:
+
+
+
+
+
+
+
++set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}
+
+ |
+
+
+
+
+
+
+
+
+
+ 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 Appendix for a brief example
+ on troubleshooting actions.
+
+
+
+
+
+
+ Custom "actions", known to Privoxy as "aliases", 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, "=", "{" and "}", but we strongly recommend
+ that you only use "a" to "z", "0" to "9", "+", and "-". Alias names are not case sensitive, and
+ are not required to start with a "+" or
+ "-" sign, since they are merely
+ textually expanded.
+
+
+ Aliases can be used throughout the actions file, but they must be defined in a special
+ section at the top of the file! 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.
+
+
+ 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 "shop", you can later change your policy on shops in
+ one place,
+ and your changes will take effect everywhere in the actions file
+ where the "shop" alias is used. Calling
+ aliases by their purpose also makes your actions files more
+ readable.
+
+
+ Currently, there is one big drawback to using aliases, though:
+ Privoxy'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.
+
+
+ Now let's define some aliases...
+
+
+
+ ...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 "/" pattern): # These sites are either very complex or very keen on
+ c1 = -crunch-all-cookies
+
+ |
+
+
+
+
+ ...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 "/" pattern):
+
+
+
+
+
+
+
+ # 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{all-popups}}
+ {-filter{all-popups} -filter{unsolicited-popups}}
.dabs.com
- .overclockers.co.uk | Aliases like "shop" and "fragile" are often used for
- "problem" sites that require some actions to be disabled
- in order to function properly. 8.7. Actions Files Tutorial The above chapters have shown which actions files
- there are and how they are organized, how actions are specified and applied
- to URLs, how patterns work, and how to
- define and use aliases. Now, let's look at an
- example default.action and user.action
- file and see how all these pieces come together: 8.7.1. default.actionEvery config file should start with a short comment stating its purpose: # Sample default.action file <ijbswa-developers@lists.sourceforge.net> |
Then, since this is the default.action file, the
-first section is a special section for internal use that you needn't
-change or worry about: ##########################################################################
+ .overclockers.co.uk
+
+ |
+
+
+
+
+ Aliases like "shop" and "fragile" are typically used for "problem" sites that require more than one action to
+ be disabled in order to function properly.
+
+
+
+
+
+ The above chapters have shown which
+ actions files there are and how they are organized, how actions
+ are specified and applied to URLs, how patterns work, and how to
+ define and use aliases.
+ Now, let's look at an example match-all.action, default.action and user.action file and see how all these pieces come
+ together:
+
+
+
+
+ Remember all actions
+ are disabled when matching starts, so we have to
+ explicitly enable the ones we want.
+
+
+ While the match-all.action file only
+ contains a single section, it is probably the most important one.
+ It has only one pattern, "/", but this pattern matches all URLs. Therefore,
+ the set of actions used in this "default" section will be applied to all requests as a start.
+ It can be partly or wholly overridden by other actions files like
+ default.action and user.action, but it will still be largely
+ responsible for your overall browsing experience.
+
+
+ Again, at the start of matching, all actions are disabled, so
+ there is no need to disable any actions here. (Remember: a "+" preceding the action name enables the
+ action, a "-" disables!). Also note
+ how this long line has been made more readable by splitting it
+ into multiple lines with line continuation.
+
+
+
+
+
+
+ The default behavior is now set.
+
+
+
+
+
+ If you aren't a developer, there's no need for you to edit the
+ default.action file. It is maintained
+ by the Privoxy developers and if
+ you disagree with some of the sections, you should overrule them
+ in your user.action.
+
+
+ Understanding the default.action file
+ can help you with your user.action,
+ though.
+
+
+ The first section in this file is a special section for internal
+ use that prevents older Privoxy
+ versions from reading the file:
+
+
+
+
+
+
+
+##########################################################################
# Settings -- Don't change! For internal Privoxy use ONLY.
##########################################################################
-
{{settings}}
-for-privoxy-version=3.0 | After that comes the (optional) alias section. We'll use the example
-section from the above chapter on aliases,
-that also explains why and how aliases are used: ##########################################################################
+for-privoxy-version=3.0.11
+
+ |
+
+
+
+
+ After that comes the (optional) alias section. We'll use the
+ example section from the above chapter on aliases, that also
+ explains why and how aliases are used:
+
+
+
+ Now come the regular sections, i.e. sets of actions, accompanied
- by URL patterns to which they apply. Remember all actions
- are disabled when matching starts, so we have to explicitly
- enable the ones we want. The first regular section is probably the most important. It has only
- one pattern, "/", but this pattern
- matches all URLs. Therefore, the
- set of actions used in this "default" section will
- be applied to all requests as a start. 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. 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 "+"
- preceding the action name enables the action, a "-" disables!).
- Also note how this long line has been made more readable by splitting it into
- multiple lines with line continuation.
+
+
+ The first of our specialized sections is concerned with "fragile" 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 fragile alias
+ instead of stating the list of actions explicitly:
+
+
+
+ The default behavior is now set. Note that some actions, like not hiding
- the user agent, are part of a "general policy" that applies
- universally and won't get any exceptions defined later. Other choices,
- like not blocking (which is understandably the
- default!) need exceptions, i.e. we need to specify explicitly what we
- want to block in later sections. The first of our specialized sections is concerned with "fragile"
- 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 fragile alias instead of stating the list
- of actions explicitly: ##########################################################################
# Exceptions for sites that'll break under the default action set:
##########################################################################
@@ -6796,243 +5719,168 @@ CLASS="SCREEN"
#
{ fragile }
.office.microsoft.com # surprise, surprise!
-.windowsupdate.microsoft.com |
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: # Shopping sites:
+.windowsupdate.microsoft.com
+mail.google.com
+
+ |
+
+
+
+
+ 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:
+
+
+
+
+
+
+
+# Shopping sites:
#
{ shop }
-.quietpc.com
+.quietpc.com
.worldpay.com # for quietpc.com
.jungle.com
-.scan.co.uk | The fast-redirects
- action, which we enabled per default above, breaks some sites. So disable
- it for popular sites where we know it misbehaves:
+
+
+ The fast-redirects
+ action, which may have been enabled in match-all.action, breaks some sites. So disable
+ it for popular sites where we know it misbehaves:
+
+
+
+
+
+
+
+{ -fast-redirects }
login.yahoo.com
edit.*.yahoo.com
.google.com
.altavista.com/.*(like|url|link):http
.altavista.com/trans.*urltext=http
-.nytimes.com | It is important that Privoxy knows which
- URLs belong to images, so that if 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 and
- information). We can mark any URL as an image with the handle-as-image action,
- and marking all URLs that end in a known image file extension is a
- good start: ##########################################################################
+.nytimes.com
+
+ |
+
+
+
+
+ It is important that Privoxy
+ knows which URLs belong to images, so that if 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 handle-as-image
+ action, and marking all URLs that end in a known image file
+ extension is a good start:
+
+
+
+
+
+
+
+##########################################################################
# Images:
##########################################################################
# Define which file types will be treated as images, in case they get
# blocked further down this file:
#
-{ +handle-as-image }
-/.*\.(gif|jpe?g|png|bmp|ico)$ | 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 and
- mark them as images in one go, with the help of our
- block-as-image alias defined above. (We could of
- course just as well use +block
- +handle-as-image here.)
- Remember that the type of the replacement image is chosen by the
- set-image-blocker
- action. Since all URLs have matched the default section with its
- +set-image-blocker{pattern}
- action before, it still applies and needn't be repeated: # Known ad generators:
+{ +handle-as-image }
+/.*\.(gif|jpe?g|png|bmp|ico)$
+
+ |
+
+
+
+
+ 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 and mark them as images
+ in one go, with the help of our +block-as-image alias defined above. (We could of
+ course just as well use +block +handle-as-image
+ here.) Remember that the type of the replacement image is chosen
+ by the set-image-blocker
+ action. Since all URLs have matched the default section with its
+ +set-image-blocker{pattern}
+ action before, it still applies and needn't be repeated:
+
+
+
+
+
+
+
+# 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 | One of the most important jobs of Privoxy
- is to block banners. A huge bunch of them are already "blocked"
- by the filter{banners-by-size}
- 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
- block action to them. 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: ##########################################################################
+.qkimg.net
+
+ |
+
+
+
+
+ One of the most important jobs of Privoxy is to block banners. Many of these
+ can be "blocked" by the filter{banners-by-size}
+ 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 block action to them.
+
+
+ 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:
+
+
+
+
+
+
+
+##########################################################################
# Block these fine banners:
##########################################################################
-{ +block }
+{ +block{Banner ads.} }
# Generic patterns:
-#
+#
ad*.
.*ads.
banner?.
@@ -7042,139 +5890,67 @@ count*.
# Site-specific patterns (abbreviated):
#
-.hitbox.com | You wouldn't believe how many advertisers actually call their banner
- servers ads.company.com, or call the directory
- in which the banners are stored simply "banners". So the above
- generic patterns are surprisingly effective. But being very generic, they necessarily also catch URLs that we don't want
- to block. The pattern .*ads. e.g. catches
- "nasty-ads.nasty-corp.com" as intended,
- but also "downloads.sourcefroge.net" or
- "adsl.some-provider.net." So here come some
- well-known exceptions to the +block
- section above. Note that these are exceptions to exceptions from the default! Consider the URL
- "downloads.sourcefroge.net": Initially, all actions are deactivated,
- so it wouldn't get blocked. Then comes the defaults section, which matches the
- URL, but just deactivates the block
- action once again. Then it matches .*ads., an exception to the
- general non-blocking policy, and suddenly
- +block applies. And now, it'll match
- .*loads., where -block
- applies, so (unless it matches again further down) it ends up
- with no block action applying. ##########################################################################
+.hitbox.com
+
+ |
+
+
+
+
+ It's quite remarkable how many advertisers actually call their
+ banner servers ads.company.com, or call the directory in
+ which the banners are stored simply "banners". So the above generic patterns are
+ surprisingly effective.
+
+
+ But being very generic, they necessarily also catch URLs that we
+ don't want to block. The pattern .*ads.
+ e.g. catches "nasty-ads.nasty-corp.com" as
+ intended, but also "downloads.sourcefroge.net" or "adsl.some-provider.net." So here
+ come some well-known exceptions to the +block section above.
+
+
+ Note that these are exceptions to exceptions from the default!
+ Consider the URL "downloads.sourcefroge.net": Initially, all
+ actions are deactivated, so it wouldn't get blocked. Then comes
+ the defaults section, which matches the URL, but just deactivates
+ the block action once again. Then
+ it matches .*ads., an exception to the
+ general non-blocking policy, and suddenly +block applies. And now,
+ it'll match .*loads., where -block
+ applies, so (unless it matches again further down) it ends up with no block
+ action applying.
+
+
+
+
+
+
+
+##########################################################################
# Save some innocent victims of the above generic block patterns:
##########################################################################
# By domain:
-#
-{ -block }
+#
+{ -block }
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)
@@ -7186,230 +5962,182 @@ ad[ud]*. # (adult.* and add.*)
# Site-specific:
#
www.globalintersec.com/adv # (adv = advanced)
-www.ugu.com/sui/ugu/adv | Filtering source code can have nasty side effects,
- so make an exception for our friends at sourceforge.net,
- and all paths with "cvs" in them. Note that
- -filter
- disables all filters in one fell swoop! # Don't filter code!
+www.ugu.com/sui/ugu/adv
+
+ |
+
+
+
+
+ Filtering source code can have nasty side effects, so make an
+ exception for our friends at sourceforge.net, and all paths with
+ "cvs" in them. Note that -filter
+ disables all filters in one fell swoop!
+
+
+
+
+
+
+
+# Don't filter code!
#
-{ -filter }
-/.*cvs
-.sourceforge.net | The actual default.action is of course more
- comprehensive, but we hope this example made clear how it works. 8.7.2. user.action 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 user.action, which is parsed after all other
- actions files and hence has the last word, over-riding any previously
- defined actions. user.action is also a
- safe place for your personal settings, since
- default.action is actively maintained by the
- Privoxy developers and you'll probably want
- to install updated versions from time to time. So let's look at a few examples of things that one might typically do in
- user.action: # My user.action file. <fred@foobar.com> |
As aliases are local to the actions
- file that they are defined in, you can't use the ones from
- default.action, unless you repeat them here: # Aliases are local to the file they are defined in.
+{ -filter }
+/(.*/)?cvs
+bugzilla.
+developer.
+wiki.
+.sourceforge.net
+
+ |
+
+
+
+
+ The actual default.action is of course
+ much more comprehensive, but we hope this example made clear how
+ it works.
+
+
+
+
+
+ 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 user.action, which is parsed after all other
+ actions files and hence has the last word, over-riding any
+ previously defined actions. user.action
+ is also a safe place for your personal settings,
+ since default.action is actively
+ maintained by the Privoxy
+ developers and you'll probably want to install updated versions
+ from time to time.
+
+
+ So let's look at a few examples of things that one might
+ typically do in user.action:
+
+
+
+
+
+
+
+# My user.action file. <fred@example.com>
+
+ |
+
+
+
+
+ As aliases are local to
+ the actions file that they are defined in, you can't use the ones
+ from default.action, unless you repeat
+ them here:
+
+
+
+
+
+
+
+# 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
+#
+# 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
allow-all-cookies = -crunch-all-cookies -session-cookies-only
- allow-popups = -filter{all-popups} -kill-popups
-+block-as-image = +block +handle-as-image
+ 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 -kill-popups
+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} |
+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 = - filter +- content-type-overwrite{text/plain} +- force-text-mode - hide-content-disposition
+
+ |
+
+