The actions files are used to define what actions
+> The actions files are used to define what actions
Privoxy takes for which URLs, and thus determine
+> takes for which URLs, and thus determines
how ad images, cookies and various other aspects of HTTP content and
- transactions are handled, and on which sites (or even parts thereof). There
- are three such files included with There
+ are three action files included with Privoxy (as of
- version 2.9.15), with differing purposes:
+> with
+ differing purposes:
Privoxy's
Edit Set to Cautious Set to Medium Set to Advanced +
These have increasing levels of aggressiveness and have no influence on your browsing unless - you select them explicitly in the editorand have no + influence on your browsing unless you select them explicitly in the + editor. It is not recommend - to edit this file. +>. A default installation should be pre-set to + Cautious (versions prior to 3.0.5 were set to + Medium). New users should try this for a while before + adjusting the settings to more aggressive levels. The more aggressive + the settings, then the more likelihood there is of problems such as sites + not working as they should. +
The Edit button allows you to turn each + action on/off individually for fine-tuning. The Cautious + button changes the actions list to low/safe settings which will activate + ad blocking and a minimal set of Privoxy's features, and subsequently + there will be less of a chance for accidental problems. The + Medium button sets the list to a medium level of + other features and a low level set of privacy features. The + Advanced button sets the list to a high level of + ad blocking and medium level of privacy. See the chart below. The latter + three buttons over-ride any changes via with the + Edit button. More fine-tuning can be done in the + lower sections of this internal page. +
It is not recommend to edit the standard.action file + itself. +
The default profiles, and their associated actions, as pre-defined in + standard.action are: +
Table 1. Default Configurations
| Feature | Cautious | Medium | Advanced |
|---|---|---|---|
| Ad-blocking Aggressiveness | medium | high | high |
| Ad-filtering by size | no | yes | yes |
| Ad-filtering by link | no | no | yes |
| Pop-up killing | blocks only | blocks only | blocks only |
| Privacy Features | low | medium | medium/high |
| Cookie handling | none | session-only | kill |
| Referer forging | no | yes | yes |
| GIF de-animation | no | yes | yes |
| Fast redirects | no | no | yes |
| HTML taming | no | no | yes |
| JavaScript taming | no | no | yes |
| Web-bug killing | no | yes | yes |
| Image tag reordering | no | no | yes |
The list of actions files to be used are defined in the main configuration - file, and are processed in the order they are defined. The content of these - can all be viewed and edited from default.action is typically processed before + user.action). The content of these can all be viewed and + edited from http://config.privoxy.org/show-status.
. + The over-riding principle when applying actions, is that the last action that + matches a given URL wins. The broadest, most general rules go first + (defined in default.action), + followed by any exceptions (typically also in + default.action), which are then followed lastly by any + local preferences (typically in user.action). + Generally, user.action has the last word. + An actions file typically has multiple sections. If you want to use
default.action,
- with the advantage that is a separate file, which makes preserving your
+ with the advantage that it is a separate file, which makes preserving your
personal settings across Privoxy
Actions can be used to block anything you want, including ads, banners, or
- just some obnoxious URL that you would rather not see. Cookies can be accepted
+ just some obnoxious URL whose content you would rather not see. Cookies can be accepted
or rejected, or accepted only during the current browser session (i.e. not
- written to disk), content can be modified, JavaScripts tamed, user-tracking
+ written to disk), content can be modified, some JavaScripts tamed, user-tracking
fooled, and much more. See below for a complete list
@@ -211,7 +528,9 @@ CLASS="SECT2"
>8.1. Finding the Right Mix
8.1. Finding the Right Mix
We have tried to provide you with reasonable rules to start from in the @@ -243,7 +563,9 @@ CLASS="SECT2" >
The easiest way to edit the actions files is with a browser by using our browser-based editor, which can be reached from http://config.privoxy.org/show-status. - The editor allows both fine-grained control over every single feature on a - per-URL basis, and easy choosing from wholesale sets of defaults like - enable-edit-actions must be enabled for + this to work. The editor allows both fine-grained control over every single + feature on a per-URL basis, and easy choosing from wholesale sets of defaults + like "Cautious", "Medium" or or + "Advanced".
. Warning: the "Advanced" setting is more + aggressive, and will be more likely to cause problems for some sites. + Experienced users only! +If you prefer plain text editing to GUIs, you can of course also directly edit the - the actions files. Look at default.action which is richly - commented.
which is richly commented with many + good examples. Actions files are divided into sections. There are special sections,
like the To determine which actions apply to a request, the URL of the request is
- compared to all patterns in each action file file. Every time it matches, the list of
- applicable actions for the URL is incrementally updated, using the heading
- of the section in which the pattern is located. If multiple matches for
- the same URL set the same action differently, the last match wins. If not,
- the effects are aggregated. E.g. a URL might match a regular section with
- a heading line of "action file"
If multiple applying sections set the same action differently, + the last match wins. If not, the effects are aggregated. + E.g. a URL might match a regular section with a heading line of { +both actions to apply.
actions to apply. And there may well be + cases where you will want to combine actions together. Such a section then + might look like:
{ +handle-as-image +block }
+ # Block these as if they were images. Send no block page.
+ banners.example.com
+ media.example.com/.*banners
+ .example.com/images/ads/ |
You can trace this process for any given URL by visiting You can trace this process for URL patterns and any given URL by visiting http://config.privoxy.org/show-url-info.
More detail on this is provided in the Appendix, Examples and more detail on this is provided in the Appendix, Anatomy of an Action.
Troubleshooting: Anatomy of an Action section.+ As mentioned, Privoxy uses "patterns" + to determine what actions might apply to which sites and + pages your browser attempts to access. These "patterns" use wild + card type pattern matching to achieve a high degree of + flexibility. This allows one expression to be expanded and potentially match + against many similar patterns.
Generally, a pattern has the form Generally, an URL pattern has the form + <domain>/<path>, - where both the , where both the + <domain> and <path> - are optional. (This is why the pattern are + optional. (This is why the special / matches all URLs).
pattern matches all + URLs). Note that the protocol portion of the URL pattern (e.g. + http://) should not be included in + the pattern. This is assumed already!The pattern matching syntax is different for the domain and path parts of + the URL. The domain part uses a simple globbing type matching technique, + while the path part uses a more flexible + "Regular + Expressions (PCRE)" based syntax.
matches all the documents on www.example.com + whose name starts with /index.html. +
any web server. +> web server anywhere.
matches nothing, since it would be interpreted as a domain name and +> matches nothing, since it would be interpreted as a domain name and there is no top-level domain called .html. +>. So its + a mistake.
The matching of the domain part offers some flexible options: if the domain starts or ends with a dot, it becomes unanchored at that end. @@ -511,28 +961,64 @@ CLASS="EMPHASIS" > .example. - (Correctly speaking: It matches any FQDN that contains . + And, by the way, also included would be any files or documents that exist + within that domain since no path limitations are specified. (Correctly + speaking: It matches any FQDN that contains example as a domain.) +> as + a domain.) This might be www.example.com, + news.example.de, or + www.example.net/cgi/testing.pl for instance. All these + cases are matched.
Additionally, there are wild-cards that you can use in the domain names - themselves. They work pretty similar to shell wild-cards: "*" - stands for zero or more arbitrary characters, represents zero or more arbitrary characters (this is + equivalent to the + "?" stands for - any single character, you can define character classes in square - brackets and all of that can be freely mixed:
"Regular + Expression" based syntax of ".*"), + "?" represents any single character (this is equivalent to the + regular expression syntax of a simple "."), and you can define + "character classes" in square brackets which is similar to + the same regular expression technique. All of this can be freely mixed:
While flexible, this is not the sophistication of full regular expression based syntax.
Privoxy uses Perl compatible regular expressions +> uses Perl compatible (PCRE) + "Regular + Expression" based syntax (through the PCRE library) for - matching the path.
There is an man perlre) useful, which is available on-line at http://www.perldoc.com/perl5.6/pod/perlre.htmlhttp://perldoc.perl.org/perlre.html.
Note that the path pattern is automatically left-anchored at the exactly this capitalization.
Is equivalent to just ".example.com", since any documents + within that domain are matched with or without the ".*" + regular expression. This is redundant +
Will match any page in the domain of "example.com" that is + named "index.html", and that is part of some path. For + example, it matches "www.example.com/testing/index.html" but + NOT "www.example.com/index.html" because the regular + expression called for at least two "/'s", thus the path + requirement. It also would match + "www.example.com/testing/index_html", because of the + special meta-character ".". +
This regular expression is conditional so it will match any page + named "index.html" regardless of path which in this case can + have one or more "/'s". And this one must contain exactly + ".html" (but does not have to end with that!). +
This regular expression will match any path of "example.com" + that contains any of the words "ads", "banner", + "banners" (because of the "?") or "junk". + The path does not have to end in these words, just contain them. +
This is very much the same as above, except now it must end in either + ".jpg", ".jpeg", ".gif" or ".png". So this + one is limited to common image formats. +
There are many, many good examples to be found in default.action, + and more tutorials below in Appendix on regular expressions.
Tag patterns are used to change the applying actions based on the + request's tags. Tags can be created with either the + client-header-tagger + or the server-header-tagger action.
Tag patterns have to start with "TAG:", so Privoxy + can tell them apart from URL patterns. Everything after the colon + including white space, is interpreted as a regular expression with + path pattern syntax, except that tag patterns aren't left-anchored + automatically (Privoxy doesn't silently add a "^", + you have to do it yourself if you need it).
To match all requests that are tagged with "foo" + your pattern line should be "TAG:^foo$", + "TAG:foo" would work as well, but it would also + match requests whose tags contain "foo" somewhere. + "TAG: foo" wouldn't work as it requires white space.
Sections can contain URL and tag patterns at the same time, + but tag patterns are checked after the URL patterns and thus + always overrule them, even if they are located before the URL patterns.
Once a new tag is added, Privoxy checks right away if it's matched by one + of the tag patterns and updates the action settings accordingly. As a result + tags can be used to activate other tagger actions, as long as these other + taggers look for headers that haven't already be parsed.
For example you could tag client requests which use the + POST method, + then use this tag to activate another tagger that adds a tag if cookies + are sent, and then use a block action based on the cookie tag. This allows + the outcome of one action, to be input into a subsequent action. However if + you'd reverse the position of the described taggers, and activated the + method tagger based on the cookie tagger, no method tags would be created. + The method tagger would look for the request line, but at the time + the cookie tag is created, the request line has already been parsed.
While this is a limitation you should be aware of, this kind of + indirection is seldom needed anyway and even the example doesn't + make too much sense.
All actions are disabled by default, until they are explicitly enabled somewhere in an actions file. Actions are turned on if preceded with a @@ -755,7 +1491,7 @@ CLASS="LITERAL" of the actions file.
- There are three classes of actions:
Example: +hide-user-agent{ Mozilla 1.0 }+hide-user-agent{Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.8.1.4) Gecko/20070602 Firefox/2.0.0.4} Privoxy would just be a - normal, non-blocking, non-anonymizing proxy. You must specifically enable the + 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 actions always over-ride earlier ones. So exceptions - to any rules you make, should come in the latter part of the file (or - in a file that is processed later when using multiple actions files). For - multi-valued actions, the actions are applied in the order they are specified. - Actions files are processed in the order they are defined in - 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 pattern to match more than - one pattern and thus more than one set of actions!
(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 Block ads or other obnoxious content Requests for URLs to which this action applies are blocked, i.e. the requests are not
- forwarded to the remote server, but answered locally with a substitute page or image,
- as determined by the 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
- and ,
+ set-image-blocker, and
+ handle-as-empty-document actions.
+
The 8.5.1. add-header
8.5.1. add-header8.5.2. block
8.5.2. block{+block} # Block and replace with "blocked" page
-.nasty-stuff.example.com
+>{+block}
+# Block and replace with "blocked" page
+ .nasty-stuff.example.com
-{+block +handle-as-image} # Block and replace with image
-.ad.doubleclick.net
-.ads.r.us
Prevent the web server from setting any cookies on your system +> Rewrite or remove single client headers.
Deletes any "Set-Cookie:" HTTP headers from server replies. +> All client headers to which this action applies are filtered on-the-fly through + the specified regular expression based substitutions.
Boolean.
Parameterized.N/A +> The name of a client-header filter, as defined in one of the + filter files.
This action is only concerned with incoming cookies. For - outgoing cookies, use - crunch-outgoing-cookies. - Use both to disable cookies completely. +> 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.
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. +> Client-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 client-header filters are available by default, and how to + create your own.
+crunch-incoming-cookies{+client-header-filter{hide-tor-exit-notation}} +.exit/ + |
Prevent the web server from reading any cookies from your system +> Block requests based on their headers.
Deletes any "Cookie:" HTTP headers from client requests. +> 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.
Boolean.
Parameterized.N/A +> The name of a client-header tagger, as defined in one of the + filter files.
This action is only concerned with outgoing cookies. For - incoming cookies, use - crunch-incoming-cookies. - Use both to disable cookies completely. -
Client-header taggers are applied to each header on its own, + and as the header isn't modified, each tagger "sees" + the original. +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. +> Client-header taggers are the first actions that are executed + and their tags can be used to control every other action.
+crunch-outgoing-cookies# Tag every request with the User-Agent header +{+client-header-tagger{user-agent}} +/ + |
Stop those annoying, distracting animated GIF images.
Stop useless download menus from popping up, or change the browser's rendering modeDe-animate GIF animations, i.e. reduce them to their first or last image. +> Replaces the "Content-Type:" HTTP server header.
"last" or "first" +> Any string.
This will also shrink the images considerably (in bytes, not pixels!). If - the option The "first" is given, the first frame of the animation - is used as the replacement. If "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 "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). +>"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.
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. +> 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.
+deanimate-gifs{last}# 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 |
Work around (very rare) problems with HTTP/1.1
Remove a client header Privoxy has no dedicated action for.Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0. +> Deletes every header sent by the client that contains the string the user supplied as parameter.
Boolean.
Parameterized.N/A +> Any string.
This is a left-over from the time when This action allows you to block client headers for which no dedicated + 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. +> 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. + |
{+downgrade-http-version}
-problem-host.example.com# Block the non-existent "Privacy-Violation:" client header
+{ +crunch-client-header{Privacy-Violation:} }
+/
+ Fool some click-tracking scripts and speed up indirect links
Prevent yet another way to track the user's steps between sessions.Cut off all but the last valid URL from requests. +> Deletes the "If-None-Match:" HTTP client header.
- 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://some.place/click-tracker.cgi?target=http://some.where.else. -
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. +Sometimes, there are even multiple consecutive redirects encoded in the - URL. These redirections via scripts make your web browsing more traceable, - since the server from which you follow such a link can see where you go - to. Apart from that, valuable bandwidth and time is wasted, while your - browser ask the server for one redirect after the other. Plus, it feeds - the advertisers. +> It is also useful to make sure the header isn't used as a cookie + replacement (unlikely but possible).
This feature is currently not very smart and is scheduled for improvement. - It is likely to break some sites. You should expect to need possibly - many exceptions to this action, if it is enabled by default in +> 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 default.action. Some sites just don't work without - it. +CLASS="LITERAL" +>hide-if-modified-since + and + overwrite-last-modified.
{+fast-redirects}# 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}
+/ |
Get rid of HTML and JavaScript annoyances, banner advertisements (by size), do fun text replacements, etc.
Prevent the web server from setting HTTP cookies on your system +Text documents, including HTML and JavaScript, to which this action - applies, are filtered on-the-fly through the specified regular expression - based substitutions. +> Deletes any "Set-Cookie:" HTTP headers from server replies.
Parameterized.
Boolean.The name of a filter, as defined in the filter file - (typically default.filter, set by the - filterfile - option in the config file). Filtering - can be completely disabled without the use of parameters. +> N/A
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. -
This is potentially a very powerful feature! But "rolling your own" - filters requires a knowledge of regular expressions and HTML. -
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. -
The amount of data that can be filtered is limited to the +> This action is only concerned with incoming HTTP cookies. For + outgoing HTTP cookies, use buffer-limitcrunch-outgoing-cookies - 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 are not filtered. +>. + Use both to disable HTTP cookies completely.
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 - It makes no sense at all to use this action in conjunction + with the prevent-compressionsession-cookies-only - action in conjunction with filter. -
Filtering can achieve some of the same effects as the +> action, + since it would prevent the session cookies from being set. See also blockfilter-content-cookies - 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! +>.
+filter{html-annoyances} # Get rid of particularly annoying HTML abuse.+crunch-incoming-cookies |
Remove a server header Privoxy has no dedicated action for.
Deletes every header sent by the server that contains the string the user supplied as parameter. +
+filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse |
Any string.
This action allows you to block server headers for which no dedicated + Privoxy action exists. Privoxy -
+filter{banners-by-size} # Kill banners based on their size for this page ( |
+filter{banners-by-link} # Kill banners based on the link they are contained in (experimental) |
+filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effectiveWarning |
+filter{content-cookies} # Kill cookies that come sneaking in the HTML or JS contentDon't block any header without understanding the consequences. + |
+filter{popups} # Kill all popups in JS and HTML# Crunch server headers that try to prevent caching
+{ +crunch-server-header{no-cache} }
+/ |
+filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking) |
Prevent the web server from reading any HTTP cookies from your system
+filter{fun} # Text replacements for subversive browsing fun! |
+filter{frameset-borders} # Give frames a border and make them resizeable |
N/A
+filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups)+crunch-outgoing-cookies |
Stop those annoying, distracting animated GIF images.
De-animate GIF animations, i.e. reduce them to their first or last image. +
Parameterized.
"last" or "first" -
+filter{nimda} # Remove Nimda (virus) code.+deanimate-gifs{last} |
Work around (very rare) problems with HTTP/1.1
Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0. +
Boolean.
N/A
This is a left-over from the time when Privoxy -
+filter{shockwave-flash} # Kill embedded Shockwave Flash objects{+downgrade-http-version}
+problem-host.example.com |
Fool some click-tracking scripts and speed up indirect links.
Detects redirection URLs and redirects the browser without contacting + the redirection server first. +
Parameterized.
"simple-check" to just search for the string "http://" + to detect redirection URLs. +
"check-decoded-url" to decode URLs (if necessary) before searching + for redirection URLs. +
+ 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. +
{ +fast-redirects{simple-check} }
+ one.example.com
+
+ { +fast-redirects{check-decoded-url} }
+ another.example.com/testing |
Get rid of HTML and JavaScript annoyances, banner advertisements (by size), + do fun text replacements, add personalized effects, etc.
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.) +
Parameterized.
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. +
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. +
"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, unless Privoxy + is compiled with zlib support (requires at least Privoxy 3.0.7), + in which case Privoxy will decompress the content before filtering + 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. +
+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. Useful if your browser lacks this ability. |
+filter{all-popups} # Kill all popups in JavaScript and HTML. Useful if your browser lacks this ability. |
+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 resizeable |
+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 savable |
+filter{fun} # Text replacements for subversive browsing fun! |
+filter{crude-parental} # Crude parental filtering (demo only) |
+filter{ie-exploits} # Disable a known Internet Explorer bug exploits |
+filter{site-specifics} # Custom filters for specific site related problems |
+filter{google} # Removes text ads and other Google specific improvements |
+filter{yahoo} # Removes text ads and other Yahoo specific improvements |
+filter{msn} # Removes text ads and other MSN specific improvements |
+filter{blogspot} # Cleans up Blogspot blogs |
+filter{no-ping} # Removes non-standard ping attributes from anchor and area tags |
Force Privoxy to treat a document as if it was in some kind of text format.
Declares a document as text, even if the "Content-Type:" isn't detected as such. +
Boolean.
N/A +
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. + |
+force-text-mode + |
Change the forwarding settings based on User-Agent or request origin
Overrules the forward directives in the configuration file. +
Multi-value.
"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. +
"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. +
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. + Use the show-url-info CGI page + to verify that your forward settings do what you thought the do. + |
# Always use direct connections 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.
+{+forward-override{forward .} \
+ -hide-if-modified-since \
+ -overwrite-last-modified \
+}
+TAG:^User-Agent: fetch libfetch/2\.0$
+ |
Mark URLs that should be replaced by empty documents if they get blocked
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. +
Boolean.
N/A +
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. +
# 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}
+example.org/.*\.js$
+ |
Mark URLs as belonging to images (so they'll be replaced by images if they do get blocked, rather than HTML pages)
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. +
Boolean.
N/A +
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. +
# Generic image extensions:
+#
+{+handle-as-image}
+/.*\.(gif|jpg|jpeg|png|bmp|ico)$
+
+# These don't look like images, but they're banners and should be
+# blocked as images:
+#
+{+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 |
Pretend to use different language settings.
Deletes or replaces the "Accept-Language:" HTTP header in client requests. +
Parameterized.
Keyword: "block", or any user defined value. +
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. +
# 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} \
+}
+/ |
Prevent download menus for content you prefer to view inside the browser.
Deletes or replaces the "Content-Disposition:" HTTP header set by some servers. +
Parameterized.
Keyword: "block", or any user defined value. +
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. +
# Disarm the download link in Sourceforge's patch tracker
+{ -filter \
+ +content-type-overwrite{text/plain}\
+ +hide-content-disposition{block} }
+ .sourceforge.net/tracker/download\.php |
Prevent yet another way to track the user's steps between sessions.
Deletes the "If-Modified-Since:" HTTP client header or modifies its value. +
Parameterized.
Keyword: "block", or a user defined value that specifies a range of hours. +
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 + 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. +
# Let the browser revalidate without being tracked across sessions
+{ +hide-if-modified-since{-60} \
+ +overwrite-last-modified{randomize} \
+ +crunch-if-none-match}
+/ |
Improve privacy by not embedding the source of the request in the HTTP headers.
Deletes any existing "X-Forwarded-for:" HTTP header from client requests, + and prevents adding a new one. +
Boolean.
N/A +
It is safe to leave this on. +
+hide-forwarded-for-headers |
Keep your (old and ill) browser from telling web servers your email address
Deletes any existing "From:" HTTP header, or replaces it with the + specified string. +
Parameterized.
Keyword: "block", or any user defined value. +
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. +
+hide-from-header{block} |
+hide-from-header{spam-me-senseless@sittingduck.example.com} |
Conceal which link you followed to get to a particular site
Deletes the "Referer:" (sic) HTTP header from the client request, + or replaces it with a forged one. +
Parameterized.
"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.
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".)
+filter{crude-parental} # Kill all web pages that contain the words "sex" or "warez"+hide-referrer{forge} |
+filter{js-events} # Kill all JS event bindings (Radically destructive! Only for extra nasty sites) +hide-referrer{http://www.yahoo.com/} |
Mark URLs as belonging to images (so they'll be replaced by images if they get blocked)
Conceal your type of browser and client operating systemThis 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 Replaces the value of the "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. +>"User-Agent:" HTTP header + in client requests with the specified value.
Boolean.
Parameterized.N/A +> Any user-defined string.
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. -
| Warning |
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. +> 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 :-).
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. +> More information on known user-agent strings can be found at + http://www.user-agents.org/ + and + http://en.wikipedia.org/wiki/User_agent.
# Generic image extensions:
-#
-{+handle-as-image}
-/.*\.(gif|jpg|jpeg|png|bmp|ico)$
-
-# These don't look like images, but they're banners and should be
-# blocked as images:
-#
-{+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 +hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)} |
Improve privacy by hiding the true source of the request
To protect against the MS buffer over-run in JPEG processingDeletes any existing "X-Forwarded-for:" HTTP header from client requests, - and prevents adding a new one. +> Protect against a known exploit
It is fairly safe to leave this on. +> 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 this exploit.
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. +> Note that the described exploit is only one of many, + using this action does not mean that you no longer + have to patch the client.
+hide-forwarded-for-headers+inspect-jpegs |
Keep your (old and ill) browser from telling web servers your email address
Eliminate those annoying pop-up windows (deprecated)Deletes any existing "From:" HTTP header, or replaces it with the - specified string. +> While loading the document, replace JavaScript code that opens + pop-up windows with (syntactically neutral) dummy code on the fly.
Parameterized.
Boolean.Keyword: "block", or any user defined value. +> N/A
The keyword "block" will completely remove the header - (not to be confused with the 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 + blockfilter{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} - action). + does a better job of catching only the unwanted ones.
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. +> 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.
This action is rarely needed, as modern web browsers don't send - "From:" headers anymore. +> This action is most appropriate for browsers that don't have any controls + for unwanted pop-ups. Not recommended for general usage.
+hide-from-header{block} |
+hide-from-header{spam-me-senseless@sittingduck.example.com}+kill-popups |
Conceal which link you followed to get to a particular site
Prevent abuse of Privoxy as a TCP proxy relay or disable SSL for untrusted sitesDeletes the "Referer:" (sic) HTTP header from the client request, - or replaces it with a forged one. +> Specifies to which ports HTTP CONNECT requests are allowable.
"block" to delete the header completely.
"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.
"forge" is the preferred option here, since some servers will - not send images back otherwise, in an attempt to prevent their valuable - content from being embedded elsewhere (and hence, without being surrounded - by their banners). +> 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.
- hide-referer is an alternate spelling of +> 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 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".) +>treat-forbidden-connects-like-blocks + as well, to be able to quickly create exceptions.
+hide-referrer{forge} |
+hide-referrer{http://www.yahoo.com/}+limit-connect{443} # This is the default and need not be specified.
++limit-connect{80,443} # Ports 80 and 443 are OK.
++limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
++limit-connect{-} # All ports are OK
++limit-connect{,} # No HTTPS/SSL traffic is allowed |
Conceal your type of browser and client operating system
Ensure that servers send the content uncompressed, so it can be + passed through filters. +Replaces the value of the "User-Agent:" HTTP header - in client requests with the specified value. +> Removes the Accept-Encoding header which can be used to ask for compressed transfer.
Parameterized.
Boolean.Any user-defined string. +> N/A
| Warning |
This breaks many web sites that depend on looking at this header in order - to customize their content for different browsers (which, by the - way, is NOT a smart way to do - that!). - |
Using this action in multi-user setups or wherever different types of - browsers will access the same When compiled with zlib support (available since 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 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 Mozilla enter, yet forging to a - 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 Netscape 6.1 user-agent works just fine. - (Must be just a silly MS goof, I'm sure :-). +>Privoxy 3.0.7 it's disabled in all + predefined action settings.
This action is scheduled for improvement. +> 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.
+hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}# 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 }
+.compusa.com/ |
Eliminate those annoying pop-up windows
Prevent yet another way to track the user's steps between sessions.While loading the document, replace JavaScript code that opens - pop-up windows with (syntactically neutral) dummy code on the fly. +> Deletes the "Last-Modified:" HTTP server header or modifies its value.
Boolean.
Parameterized.N/A +> One of the keywords: "block", "reset-to-request-time" + and "randomize"
This action is easily confused with the built-in, hardwired filter 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:" - 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 + 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 filter{popupshided-if-modified-since} - does. + to further customize your random range.
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 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 + filterhided-if-modified-since applies, - the whole document needs to be buffered anyway, which destroys the advantage of - the kill-popups action over its filter equivalent. +>, + just to be sure.
Killing all pop-ups is a dangerous business. Many shops and banks rely on - pop-ups to display forms, shopping carts etc, and killing only the unwanted pop-ups - would require artificial intelligence in Privoxy. - 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 +> It is also recommended to use this action together with filter{js-annoyancescrunch-if-none-match} - instead. +>.
+kill-popups# Let the browser revalidate without being tracked across sessions +{ +hide-if-modified-since{-60} \ + +overwrite-last-modified{randomize} \ + +crunch-if-none-match} +/ |
Prevent abuse of Privoxy as a TCP proxy relay
Redirect requests to other sites. +Specifies to which ports HTTP CONNECT requests are allowable. +> Convinces the browser that the requested document has been moved + to another location and the browser should get it from there.
Parameterized.
ParameterizedA comma-separated list of ports or port ranges (the latter using dashes, with the minimum - defaulting to 0 and the maximum to 65K). +> An absolute URL or a single pcrs command.
By default, i.e. if no 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. +
This action will be ignored if you use it together with + limit-connect action applies, - Privoxy only allows HTTP CONNECT - requests to port 443 (the standard, secure HTTPS port). Use +>block. + It can be combined with limit-connect if more fine-grained control is desired - for some or all destinations. +>fast-redirects{check-decoded-url} + to redirect to a decoded version of a rewritten URL.
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. -
If you don't know what any of this means, there probably is no reason to - change this one, since the default is already very restrictive. -
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. +
+limit-connect{443} # This is the default and need not be specified.
-+limit-connect{80,443} # Ports 80 and 443 are OK.
-+limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
-+limit-connect{-} # All ports are OK (gaping security hole!)# Replace example.com's style sheet with another one
+{ +redirect{http://localhost/css-replacements/example.com.css} }
+ example.com/stylesheet\.css
+
+# Create a short, easy to remember nickname for a favorite site
+# (relies on the browser accept and forward invalid URLs to Privoxy)
+{ +redirect{http://www.privoxy.org/user-manual/actions-file.html} }
+ a
+
+# Always use the expanded view for Undeadly.org articles
+# (Note the $ at the end of the URL pattern to make sure
+# the request for the rewritten URL isn't redirected as well)
+{+redirect{s@$@&mode=expanded@}}
+undeadly.org/cgi\?action=article&sid=\d*$ |
Ensure that servers send the content uncompressed, so it can be - passed through filters +> Feed log analysis scripts with useless data.
Adds a header to the request that asks for uncompressed transfer. +> 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.
More and more websites send their content compressed by default, which - is generally a good idea and saves bandwidth. But for the filter, 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. +
+send-vanilla-wafer |
Send custom cookies or feed log analysis scripts with even more useless data. +
Sends a custom, user-defined cookie with each request. +
Multi-value.
A string of the form "name - and kill-popups=value 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. +> Being multi-valued, multiple instances of this action can apply to the same request, + resulting in multiple cookies being sent.
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. +> This action is rarely used and not enabled in the default configuration.
# Set default:
-#
-{+prevent-compression}
-/ # Match all sites
-
-# Make exceptions for ill sites:
-#
-{-prevent-compression}
-www.debianhelp.org
-www.pclinuxonline.com{+send-wafer{UsingPrivoxy=true}}
+my-internal-testing-server.void |
Feed log analysis scripts with useless data. +> Rewrite or remove single server headers.
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. +> All server headers to which this action applies are filtered on-the-fly + through the specified regular expression based substitutions.
Boolean.
Parameterized.N/A +> The name of a server-header filter, as defined in one of the + filter files.
The vanilla wafer is a (relatively) unique header and could conceivably be used to track you. +> 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.
This action is rarely used and not enabled in the default configuration. +> 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.
+send-vanilla-wafer{+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 + |
Send custom cookies or feed log analysis scripts with even more useless data. +> Enable or disable filters based on the Content-Type header.
Sends a custom, user-defined cookie with each request. +> 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.
Multi-value.
Parameterized.A string of the form "name=value" The name of a server-header tagger, as defined in one of the + filter files.
Being multi-valued, multiple instances of this action can apply to the same request, - resulting in multiple cookies being sent. +> Server-header taggers are applied to each header on its own, + and as the header isn't modified, each tagger "sees" + the original.
This action is rarely used and not enabled in the default configuration. +> 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.
{+send-wafer{UsingPrivoxy=true}}
-my-internal-testing-server.void# Tag every request with the content type declared by the server
+{+server-header-tagger{content-type}}
+/
+ |
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. +
A good application of redirects is to use special
Redirect to the BSD devil: +> Redirect to the BSD daemon:
+treat-forbidden-connects-like-blocks |
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 @@ -3716,7 +7184,9 @@ CLASS="SECT2" >
Custom Privoxy.
Now let's define some aliases...
crunch-incoming-cookies +crunch-outgoing-cookies + -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies + +block-as-image = +block +handle-as-image + allow-all-cookies = -crunch-all-cookies -session-cookies-only -filter{content-cookies} # These aliases define combinations of actions # that are useful for certain types of sites: # - fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups - shop = -crunch-all-cookies -filter{popups} -kill-popups + fragile = -block -filter -crunch-all-cookies -fast-redirects -hide-referrer -kill-popups -prevent-compression + + shop = -crunch-all-cookies -filter{all-popups} -kill-popups # Short names for other aliases, for really lazy people ;-) # @@ -3885,7 +7394,8 @@ CLASS="SCREEN" {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) @@ -3893,11 +7403,11 @@ CLASS="SCREEN" {shop} .quietpc.com .worldpay.com # for quietpc.com - .scan.co.uk + mybank.example.com # These shops require pop-ups: # - {shop -kill-popups -filter{popups}} + {-kill-popups -filter{all-popups} -filter{unsolicited-popups}} .dabs.com .overclockers.co.uk and "fragile" are often used for +> are typically used for "problem" sites that require some actions to be disabled +> sites that require more than one action to be disabled in order to function properly.
The above chapters have shown 8.7.1. default.action
8.7.1. default.action
Every config file should start with a short comment stating its purpose:
# Sample default.action file <developers@privoxy.org># Sample default.action file <ijbswa-developers@lists.sourceforge.net>
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 "+" @@ -4102,94 +7654,26 @@ CLASS="SCREEN" # "Defaults" section: ########################################################################## { \ - -add-header \ - -block \ - -crunch-incoming-cookies \ - -crunch-outgoing-cookies \ +deanimate-gifs \ - -downgrade-http-version \ - +fast-redirects \ +filter{html-annoyances} \ +filter{js-annoyances} \ - -filter{content-cookies} \ - +filter{popups} \ - +filter{webbugs} \ - -filter{refresh-tags} \ - -filter{fun} \ +filter{nimda}filter{webbugs} \ +filter{banners-by-size} \ - -filter{banners-by-link} \ - -filter{img-reorder} \ - -filter{shockwave-flash} \ - -filter{crude-parental} \ - -filter{js-events} \ - -handle-as-image \ +HREF="actions-file.html#FILTER-IE-EXPLOITS" +>filter{ie-exploits} \ +hide-forwarded-for-headershide-referrer{forge} \ - -hide-user-agent \ - -kill-popups \ - -limit-connect \ +prevent-compression \ - -send-vanilla-wafer \ - -send-wafer \ +
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. - We will also want to make exceptions from our general pop-up-killing, - and use our defined aliases for that.
The default behavior is now set. +The first of our specialized sections is concerned with
Then, there are sites which rely on pop-up windows (yuck!) to work. - Since we made pop-up-killing our default above, we need to make exceptions - now. Mozilla users, who - can turn on smart handling of unwanted pop-ups in their browsers, can - safely choose - -filter{popups} (and - -kill-popups) above - and hence don't need this section. Anyway, disabling an already disabled - action doesn't hurt, so we'll define our exceptions regardless of what was - chosen in the defaults section:
# These sites require pop-ups too :(
-#
-{ -kill-popups -filter{popups} }
-.dabs.com
-.overclockers.co.uk
-.deutsche-bank-24.de |
The block-as-image+block-as-image alias defined above. (We could of course just as well use # Known ad generators: # -{ block-as-image } +{ +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.netPrivoxy - is to block banners. A huge bunch of them are already "blocked" @@ -4554,7 +7951,7 @@ HREF="actions-file.html#BLOCK" > action to them.
First comes a bunch of generic patterns, which do most of the work, by +> 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:
You wouldn't believe how many advertisers actually call their banner +> It's quite remarkable how many advertisers actually call their banner servers ads. } 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) @@ -4771,7 +8169,10 @@ CLASS="SCREEN" HREF="actions-file.html#FILTER" >filter } -/.*cvs +/(.*/)?cvs +bugzilla. +developer. +wiki. .sourceforge.net The actual default.action is of course more +> 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, @@ -4836,7 +8239,7 @@ WIDTH="100%" >
# My user.action file. <fred@foobar.com># My user.action file. <fred@example.com>
# (Re-)define aliases for this file:
+># Aliases are local to the file they are defined in.
+# (Re-)define aliases for this file:
#
{{alias}}
+#
+# These aliases just save typing later, and the alias names should
+# be self explanatory.
+#
++crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
-crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
-mercy-for-cookies = -crunch-all-cookies -session-cookies-only
-fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referer -kill-popups
-shop = mercy-for-cookies -filter{popups} -kill-popups
-allow-ads = -block -filter{banners-by-size} # (see below)filter +-content-type-overwrite{text/plain} +-force-text-mode -hide-content-dispositionSay you have accounts on some sites that you visit regularly, and you don't want to have to log in manually each time. So you'd like to allow persistent cookies for these sites. The mercy-for-cookiesallow-all-cookies alias defined above does exactly - that, i.e. it disables crunching of cookies in any direction, and - processing of cookies to make them temporary.
{ mercy-for-cookies }
-sunsolve.sun.com
-slashdot.org
-.yahoo.com
-.msdn.microsoft.com
-.redhat.com{ allow-all-cookies }
+ sourceforge.net
+ .yahoo.com
+ .msdn.microsoft.com
+ .redhat.com |
Your bank needs popups and is allergic to some filter, but you don't - know which, so you disable them all:
Your bank is allergic to some filter, but you don't know which, so you disable them all:
While browsing the web with Privoxy you - noticed some ads that sneaked through, but you were too lazy to - report them through our fine and easy feedback Some file types you may not want to filter for various reasons:
# Technical documentation is likely to contain strings that might +# erroneously get altered by the JavaScript-oriented filters: +# +.tldp.org +/(.*/)?selfhtml/ + +# And this stupid host sends streaming video with a wrong MIME type, +# so that Privoxy thinks it is getting HTML and starts filtering: +# +stupid-server.example.com/ |
Example of a simple block action. Say you've + seen an ad on your favourite page on example.com that you want to get rid of. + You have right-clicked the image, selected "copy image location" - system, so you have added them here:
{ +block } section. Note that { +handle-as-image + } need not be specified, since all URLs ending in + .gif will be tagged as images by the general rules as set + in default.action anyway:
Note that, assuming the banners in the above example have regular image - extensions (most do), - The URLs of dynamically generated banners, especially from large banner + farms, often don't use the well-known image file name extensions, which + makes it impossible for Privoxy to guess + the file type just by looking at the URL. + You can use the +handle-as-image - need not be specified, since all URLs ending in these extensions will - already have been tagged as images in the relevant section of - default.action by now.
+block-as-image alias defined above for + these cases. + Note that objects which match this rule but then turn out NOT to be an + image are typically rendered as a "broken image" icon by the + browser. Use cautiously.Then you noticed that the default configuration breaks Forbes Magazine, +>
{ +block-as-image }
+ .doubleclick.net
+ .fastclick.net
+ /Realmedia/ads/
+ ar.atwola.com/ |
Now you noticed that the default configuration breaks Forbes Magazine, but you were too lazy to find out which action is the culprit, and you were again too lazy to give fragile alias on the site, and - -- whoa! -- it worked:
whoa! -- it worked. The fragile + aliases disables those actions that are most likely to break a site. Also, + good for testing purposes to see if it is Privoxy + that is causing the problem or not. We later find other regular sites + that misbehave, and add those to our personalized list of troublemakers:Finally, you might think about how your favourite free websites are +> You might also worry about how your favourite free websites are funded, and find that they rely on displaying banner advertisements to survive. So you might want to specifically allow banners for those sites that you feel provide value to you:
{ allow-ads }
-.sourceforge.net
-.slashdot.org
-.osdn.netInvoke another alias here to force an over-ride of the MIME type application/x-sh which typically would open a download type + dialog. In my case, I want to look at the shell script, and then I can save + it should I choose to.
{ handle-as-text }
+ /.*\.sh$ |
user.action is generally the best place to define + exceptions and additions to the default policies of + default.action. Some actions are safe to have their + default policies set here though. So let's set a default policy to have a + "blank" image as opposed to the checkerboard pattern for + ALL sites. "/" of course matches all URL + paths and patterns:
{ +set-image-blocker{blank} }
+/ # ALL sites |