+Effect if unset:
+
+ Act as if toggled on
+
+Notes:
+
+ If set to 0, Privoxy will start in "toggled off" mode, i.e. behave like a
+ normal, content-neutral proxy where all ad blocking, filtering, etc are
+ disabled. See enable-remote-toggle below. This is not really useful
+ anymore, since toggling is much easier via the web interface than via
+ editing the conf file.
+
+ The windows version will only display the toggle icon in the system tray if
+ this option is present.
+
+-------------------------------------------------------------------------------
+
+7.4.3. enable-remote-toggle
+
+Specifies:
+
+ Whether or not the web-based toggle feature may be used
+
+Type of value:
+
+ 0 or 1
+
+Default value:
+
+ 1
+
+Effect if unset:
+
+ The web-based toggle feature is disabled.
+
+Notes:
+
+ When toggled off, Privoxy acts like a normal, content-neutral proxy, i.e.
+ it acts as if none of the actions applied to any URL.
+
+ For the time being, access to the toggle feature can not be controlled
+ separately by "ACLs" or HTTP authentication, so that everybody who can
+ access Privoxy (see "ACLs" and listen-address above) can toggle it for all
+ users. So this option is not recommended for multi-user environments with
+ untrusted users.
+
+ Note that you must have compiled Privoxy with support for this feature,
+ otherwise this option has no effect.
+
+-------------------------------------------------------------------------------
+
+7.4.4. enable-edit-actions
+
+Specifies:
+
+ Whether or not the web-based actions file editor may be used
+
+Type of value:
+
+ 0 or 1
+
+Default value:
+
+ 1
+
+Effect if unset:
+
+ The web-based actions file editor is disabled.
+
+Notes:
+
+ For the time being, access to the editor can not be controlled separately
+ by "ACLs" or HTTP authentication, so that everybody who can access Privoxy
+ (see "ACLs" and listen-address above) can modify its configuration for all
+ users. So this option is not recommended for multi-user environments with
+ untrusted users.
+
+ Note that you must have compiled Privoxy with support for this feature,
+ otherwise this option has no effect.
+
+-------------------------------------------------------------------------------
+
+7.4.5. ACLs: permit-access and deny-access
+
+Specifies:
+
+ Who can access what.
+
+Type of value:
+
+ src_addr[/src_masklen] [dst_addr[/dst_masklen]]
+
+ Where src_addr and dst_addr are IP addresses in dotted decimal notation or
+ valid DNS names, and src_masklen and dst_masklen are subnet masks in CIDR
+ notation, i.e. integer values from 2 to 30 representing the length (in
+ bits) of the network address. The masks and the whole destination part are
+ optional.
+
+Default value:
+
+ Unset
+
+Effect if unset:
+
+ Don't restrict access further than implied by listen-address
+
+Notes:
+
+ Access controls are included at the request of ISPs and systems
+ administrators, and are not usually needed by individual users. For a
+ typical home user, it will normally suffice to ensure that Privoxy only
+ listens on the localhost (127.0.0.1) or internal (home) network address by
+ means of the listen-address option.
+
+ Please see the warnings in the FAQ that this proxy is not intended to be a
+ substitute for a firewall or to encourage anyone to defer addressing basic
+ security weaknesses.
+
+ Multiple ACL lines are OK. If any ACLs are specified, then the Privoxy
+ talks only to IP addresses that match at least one permit-access line and
+ don't match any subsequent deny-access line. In other words, the last match
+ wins, with the default being deny-access.
+
+ If Privoxy is using a forwarder (see forward below) for a particular
+ destination URL, the dst_addr that is examined is the address of the
+ forwarder and NOT the address of the ultimate target. This is necessary
+ because it may be impossible for the local Privoxy to determine the IP
+ address of the ultimate target (that's often what gateways are used for).
+
+ You should prefer using IP addresses over DNS names, because the address
+ lookups take time. All DNS names must resolve! You can not use domain
+ patterns like "*.org" or partial domain names. If a DNS name resolves to
+ multiple IP addresses, only the first one is used.
+
+ Denying access to particular sites by ACL may have undesired side effects
+ if the site in question is hosted on a machine which also hosts other
+ sites.
+
+Examples:
+
+ Explicitly define the default behavior if no ACL and listen-address are
+ set: "localhost" is OK. The absence of a dst_addr implies that all
+ destination addresses are OK:
+
+ permit-access localhost
+
+ Allow any host on the same class C subnet as www.privoxy.org access to
+ nothing but www.example.com:
+
+ permit-access www.privoxy.org/24 www.example.com/32
+
+ Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere,
+ with the exception that 192.168.45.73 may not access
+ www.dirty-stuff.example.com:
+
+ permit-access 192.168.45.64/26
+ deny-access 192.168.45.73 www.dirty-stuff.example.com
+
+-------------------------------------------------------------------------------
+
+7.4.6. buffer-limit
+
+Specifies:
+
+ Maximum size of the buffer for content filtering.
+
+Type of value:
+
+ Size in Kbytes
+
+Default value:
+
+ 4096
+
+Effect if unset:
+
+ Use a 4MB (4096 KB) limit.
+
+Notes:
+
+ For content filtering, i.e. the +filter and +deanimate-gif actions, it is
+ necessary that Privoxy buffers the entire document body. This can be
+ potentially dangerous, since a server could just keep sending data
+ indefinitely and wait for your RAM to exhaust -- with nasty consequences.
+ Hence this option.
+
+ When a document buffer size reaches the buffer-limit, it is flushed to the
+ client unfiltered and no further attempt to filter the rest of the document
+ is made. Remember that there may be multiple threads running, which might
+ require up to buffer-limit Kbytes each, unless you have enabled
+ "single-threaded" above.
+
+-------------------------------------------------------------------------------
+
+7.5. Forwarding
+
+This feature allows routing of HTTP requests through a chain of multiple
+proxies. It can be used to better protect privacy and confidentiality when
+accessing specific domains by routing requests to those domains through an
+anonymous public proxy (see e.g. http://www.multiproxy.org/anon_list.htm) Or to
+use a caching proxy to speed up browsing. Or chaining to a parent proxy may be
+necessary because the machine that Privoxy runs on has no direct Internet
+access.
+
+Also specified here are SOCKS proxies. Privoxy supports the SOCKS 4 and SOCKS
+4A protocols.
+
+-------------------------------------------------------------------------------
+
+7.5.1. forward
+
+Specifies:
+
+ To which parent HTTP proxy specific requests should be routed.
+
+Type of value:
+
+ target_domain[:port] http_parent[/port]
+
+ Where target_domain is a domain name pattern (see the chapter on domain
+ matching in the default.action file), http_parent is the address of the
+ parent HTTP proxy as an IP addresses in dotted decimal notation or as a
+ valid DNS name (or "." to denote "no forwarding", and the optional port
+ parameters are TCP ports, i.e. integer values from 1 to 64535
+
+Default value:
+
+ Unset
+
+Effect if unset:
+
+ Don't use parent HTTP proxies.
+
+Notes:
+
+ If http_parent is ".", then requests are not forwarded to another HTTP
+ proxy but are made directly to the web servers.
+
+ Multiple lines are OK, they are checked in sequence, and the last match
+ wins.
+
+Examples:
+
+ Everything goes to an example anonymizing proxy, except SSL on port 443
+ (which it doesn't handle):
+
+ forward .* anon-proxy.example.org:8080
+ forward :443 .
+
+ Everything goes to our example ISP's caching proxy, except for requests to
+ that ISP's sites:
+
+ forward .*. caching-proxy.example-isp.net:8000
+ forward .example-isp.net .
+
+-------------------------------------------------------------------------------
+
+7.5.2. forward-socks4 and forward-socks4a
+
+Specifies:
+
+ Through which SOCKS proxy (and to which parent HTTP proxy) specific
+ requests should be routed.
+
+Type of value:
+
+ target_domain[:port] socks_proxy[/port] http_parent[/port]
+
+ Where target_domain is a domain name pattern (see the chapter on domain
+ matching in the default.action file), http_parent and socks_proxy are IP
+ addresses in dotted decimal notation or valid DNS names (http_parent may be
+ "." to denote "no HTTP forwarding"), and the optional port parameters are
+ TCP ports, i.e. integer values from 1 to 64535
+
+Default value:
+
+ Unset
+
+Effect if unset:
+
+ Don't use SOCKS proxies.
+
+Notes:
+
+ Multiple lines are OK, they are checked in sequence, and the last match
+ wins.
+
+ The difference between forward-socks4 and forward-socks4a is that in the
+ SOCKS 4A protocol, the DNS resolution of the target hostname happens on the
+ SOCKS server, while in SOCKS 4 it happens locally.
+
+ If http_parent is ".", then requests are not forwarded to another HTTP
+ proxy but are made (HTTP-wise) directly to the web servers, albeit through
+ a SOCKS proxy.
+
+Examples:
+
+ From the company example.com, direct connections are made to all "internal"
+ domains, but everything outbound goes through their ISP's proxy by way of
+ example.com's corporate SOCKS 4A gateway to the Internet.
+
+ forward-socks4a .*. socks-gw.example.com:1080 www-cache.example-isp.net:8080
+ forward .example.com .
+
+ A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent
+ looks like this:
+
+ forward-socks4 .*. socks-gw.example.com:1080 .
+
+-------------------------------------------------------------------------------
+
+7.5.3. Advanced Forwarding Examples
+
+If you have links to multiple ISPs that provide various special content only to
+their subscribers, you can configure multiple Privoxies which have connections
+to the respective ISPs to act as forwarders to each other, so that your users
+can see the internal content of all ISPs.
+
+Assume that host-a has a PPP connection to isp-a.net. And host-b has a PPP
+connection to isp-b.net. Both run Privoxy. Their forwarding configuration can
+look like this:
+
+host-a:
+
+ forward .*. .
+ forward .isp-b.net host-b:8118
+
+host-b:
+
+ forward .*. .
+ forward .isp-a.net host-a:8118
+
+Now, your users can set their browser's proxy to use either host-a or host-b
+and be able to browse the internal content of both isp-a and isp-b.
+
+If you intend to chain Privoxy and squid locally, then chain as browser ->
+squid -> privoxy is the recommended way.
+
+Assuming that Privoxy and squid run on the same box, your squid configuration
+could then look like this:
+
+ # Define Privoxy as parent proxy (without ICP)
+ cache_peer 127.0.0.1 parent 8118 7 no-query
+
+ # Define ACL for protocol FTP
+ acl ftp proto FTP
+
+ # Do not forward FTP requests to Privoxy
+ always_direct allow ftp
+
+ # Forward all the rest to Privoxy
+ never_direct allow all
+
+You would then need to change your browser's proxy settings to squid's address
+and port. Squid normally uses port 3128. If unsure consult http_port in
+squid.conf.
+
+-------------------------------------------------------------------------------
+
+7.6. Windows GUI Options
+
+Privoxy has a number of options specific to the Windows GUI interface:
+
+If "activity-animation" is set to 1, the Privoxy icon will animate when
+"Privoxy" is active. To turn off, set to 0.
+
+ activity-animation 1
+
+
+If "log-messages" is set to 1, Privoxy will log messages to the console window:
+
+ log-messages 1
+
+
+If "log-buffer-size" is set to 1, the size of the log buffer, i.e. the amount
+of memory used for the log messages displayed in the console window, will be
+limited to "log-max-lines" (see below).
+
+Warning: Setting this to 0 will result in the buffer to grow infinitely and eat
+up all your memory!
+
+ log-buffer-size 1
+
+
+log-max-lines is the maximum number of lines held in the log buffer. See above.
+
+ log-max-lines 200
+
+
+If "log-highlight-messages" is set to 1, Privoxy will highlight portions of the
+log messages with a bold-faced font:
+
+ log-highlight-messages 1
+
+
+The font used in the console window:
+
+ log-font-name Comic Sans MS
+
+
+Font size used in the console window:
+
+ log-font-size 8
+
+
+"show-on-task-bar" controls whether or not Privoxy will appear as a button on
+the Task bar when minimized:
+
+ show-on-task-bar 0
+
+
+If "close-button-minimizes" is set to 1, the Windows close button will minimize
+Privoxy instead of closing the program (close with the exit option on the File
+menu).
+
+ close-button-minimizes 1
+
+
+The "hide-console" option is specific to the MS-Win console version of Privoxy.
+If this option is used, Privoxy will disconnect from and hide the command
+console.
+
+ #hide-console
+
+
+-------------------------------------------------------------------------------
+
+8. Actions Files
+
+The actions files are used to define what actions Privoxy takes for which URLs,
+and thus determine how ad images, cookies and various other aspects of HTTP
+content and transactions are handled, and on which sites (or even parts
+thereof). There are three such files included with Privoxy (as of version
+2.9.15), with differing purposes:
+
+ * standard.action - is used by the web based editor, to set various
+ pre-defined sets of rules for the default actions section in
+ default.action. These have increasing levels of aggressiveness and have no
+ influence on your browsing unless you select them explicitly in the editor.
+ It is not recommend to edit this file.
+
+ * default.action - is the primary action file that sets the initial values
+ for all actions. It is intended to provide a base level of functionality
+ for Privoxy's array of features. So it is a set of broad rules that should
+ work reasonably well for users everywhere. This is the file that the
+ developers are keeping updated, and making available to users.
+
+ * user.action - is intended to be for local site preferences and exceptions.
+ As an example, if your ISP or your bank has specific requirements, and need
+ special handling, this kind of thing should go here. This file will not be
+ upgraded.
+
+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 http://config.privoxy.org/show-status.
+
+An actions file typically has multiple sections. If you want to use "aliases"
+in an actions file, you have to place the (optional) alias section at the top
+of that file. Then comes the default set of rules which will apply universally
+to all sites and pages (be very careful with using such a universal set in
+user.action or any other actions file after default.action, because it will
+override the result from consulting any previous file). And then below that,
+exceptions to the defined universal policies. You can regard user.action as an
+appendix to default.action, with the advantage that is a separate file, which
+makes preserving your personal settings across Privoxy upgrades easier.
+
+Actions can be used to block anything you want, including ads, banners, or just
+some obnoxious URL that you would rather not see. Cookies can be accepted or
+rejected, or accepted only during the current browser session (i.e. not written
+to disk), content can be modified, JavaScripts tamed, user-tracking fooled, and
+much more. See below for a complete list of actions.
+
+-------------------------------------------------------------------------------
+
+8.1. Finding the Right Mix
+
+Note that some actions, like cookie suppression or script disabling, may render
+some sites unusable that rely on these techniques to work properly. Finding the
+right mix of actions is not always easy and certainly a matter of personal
+taste. In general, it can be said that the more "aggressive" your default
+settings (in the top section of the actions file) are, the more exceptions for
+"trusted" sites you will have to make later. If, for example, you want to kill
+popup windows per default, you'll have to make exceptions from that rule for
+sites that you regularly use and that require popups for actually useful
+content, like maybe your bank, favorite shop, or newspaper.
+
+We have tried to provide you with reasonable rules to start from in the
+distribution actions files. But there is no general rule of thumb on these
+things. There just are too many variables, and sites are constantly changing.
+Sooner or later you will want to change the rules (and read this chapter again
+:).
+
+-------------------------------------------------------------------------------
+
+8.2. How to Edit
+
+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 "Cautious", "Medium" or "Advanced".
+
+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.
+
+-------------------------------------------------------------------------------
+
+8.3. How Actions are Applied to URLs
+
+Actions files are divided into sections. There are special sections, like the "
+alias" sections which will be discussed later. For now let's concentrate on
+regular sections: They have a heading line (often split up to multiple lines
+for readability) which consist of a list of actions, separated by whitespace
+and enclosed in curly braces. Below that, there is a list of URL patterns, each
+on a separate line.
+
+To determine which actions apply to a request, the URL of the request is
+compared to all patterns in each action file file. Every time it matches, the
+list of applicable actions for the URL is incrementally updated, using the
+heading of the section in which the pattern is located. If multiple matches for
+the same URL set the same action differently, the last match wins. If not, the
+effects are aggregated (e.g. a URL might match both the "+handle-as-image" and
+"+block" actions).
+
+You can trace this process for any given URL by visiting http://
+config.privoxy.org/show-url-info.
+
+More detail on this is provided in the Appendix, Anatomy of an Action.
+
+-------------------------------------------------------------------------------
+
+8.4. Patterns
+
+Generally, a pattern has the form <domain>/<path>, where both the <domain> and
+<path> are optional. (This is why the pattern / matches all URLs).
+
+www.example.com/
+
+ is a domain-only pattern and will match any request to www.example.com,
+ regardless of which document on that server is requested.
+
+www.example.com
+
+ means exactly the same. For domain-only patterns, the trailing / may be
+ omitted.
+
+www.example.com/index.html
+
+ matches only the single document /index.html on www.example.com.
+
+/index.html
+
+ matches the document /index.html, regardless of the domain, i.e. on any web
+ server.
+
+index.html
+
+ matches nothing, since it would be interpreted as a domain name and there
+ is no top-level domain called .html.
+
+-------------------------------------------------------------------------------
+
+8.4.1. The Domain Pattern
+
+The matching of the domain part offers some flexible options: if the domain
+starts or ends with a dot, it becomes unanchored at that end. For example:
+
+.example.com
+
+ matches any domain that ENDS in .example.com
+
+www.
+
+ matches any domain that STARTS with www.
+
+.example.
+
+ matches any domain that CONTAINS .example. (Correctly speaking: It matches
+ any FQDN that contains example as a domain.)
+
+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, "?" stands for any single character, you can
+define character classes in square brackets and all of that can be freely
+mixed:
+
+ad*.example.com
+
+ matches "adserver.example.com", "ads.example.com", etc but not
+ "sfads.example.com"
+
+*ad*.example.com
+
+ matches all of the above, and then some.
+
+.?pix.com
+
+ matches www.ipix.com, pictures.epix.com, a.b.c.d.e.upix.com etc.
+
+www[1-9a-ez].example.c*
+
+ matches www1.example.com, www4.example.cc, wwwd.example.cy,
+ wwwz.example.com etc., but not wwww.example.com.
+
+-------------------------------------------------------------------------------
+
+8.4.2. The Path Pattern
+
+Privoxy uses Perl compatible regular expressions (through the PCRE library) for
+matching the path.
+
+There is an Appendix with a brief quick-start into regular expressions, and
+full (very technical) documentation on PCRE regex syntax is available on-line
+at http://www.pcre.org/man.txt. You might also find the Perl man page on
+regular expressions (man perlre) useful, which is available on-line at http://
+www.perldoc.com/perl5.6/pod/perlre.html.
+
+Note that the path pattern is automatically left-anchored at the "/", i.e. it
+matches as if it would start with a "^" (regular expression speak for the
+beginning of a line).
+
+Please also note that matching in the path is case INSENSITIVE by default, but
+you can switch to case sensitive at any point in the pattern by using the "(?
+-i)" switch: www.example.com/(?-i)PaTtErN.* will match only documents whose
+path starts with PaTtErN in exactly this capitalization.
+
+-------------------------------------------------------------------------------
+
+8.5. Actions
+
+All actions are disabled by default, until they are explicitly enabled
+somewhere in an actions file. Actions are turned on if preceded with a "+", and
+turned off if preceded with a "-". So a +action means "do that action", e.g.
++block means "please block URLs that match the following patterns", and -block
+means "don't block URLs that match the following patterns, even if +block
+previously applied."
+
+Again, actions are invoked by placing them on a line, enclosed in curly braces
+and separated by whitespace, like in {+some-action -some-other-action
+{some-parameter}}, followed by a list of URL patterns, one per line, to which
+they apply. Together, the actions line and the following pattern lines make up
+a section of the actions file.
+
+There are three classes of actions:
+
+ * Boolean, i.e the action can only be "enabled" or "disabled". Syntax:
+
+ +name # enable action name
+ -name # disable action name
+
+ Example: +block
+
+ * Parameterized, where some value is required in order to enable this type of
+ action. Syntax:
+
+ +name{param} # enable action and set parameter to param,
+ # overwriting parameter from previous match if necessary
+ -name # disable action. The parameter can be omitted
+
+ Note that if the URL matches multiple positive forms of a parameterized
+ action, the last match wins, i.e. the params from earlier matches are
+ simply ignored.
+
+ Example: +hide-user-agent{ Mozilla 1.0 }
+
+ * Multi-value. These look exactly like parameterized actions, but they behave
+ differently: If the action applies multiple times to the same URL, but with
+ different parameters, all the parameters from all matches are remembered.
+ This is used for actions that can be executed for the same request
+ repeatedly, like adding multiple headers, or filtering through multiple
+ filters. Syntax:
+
+ +name{param} # enable action and add param to the list of parameters
+ -name{param} # remove the parameter param from the list of parameters
+ # If it was the last one left, disable the action.
+ -name # disable this action completely and remove all parameters from the list
+
+ 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-anonymizing proxy. You
+must specifically enable the privacy and blocking features you need (although
+the provided default actions files will give a good starting point).
+
+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 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 list of valid Privoxy actions are:
+
+-------------------------------------------------------------------------------
+
+8.5.1. add-header
+
+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.
+
+Example usage:
+
+ +add-header{X-User-Tracking: sucks}
+
+-------------------------------------------------------------------------------
+
+8.5.2. block
+
+Typical use:
+
+ Block ads or other obnoxious content
+
+Effect:
+
+ 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 handle-as-image and
+ set-image-blocker actions.
+
+Type:
+
+ Boolean.
+
+Parameter:
+
+ N/A
+
+Notes:
+
+ Privoxy sends a special "BLOCKED" page for requests to blocked pages. This
+ page contains links to find out why the request was blocked, and a
+ click-through to the blocked content (the latter only if compiled with the
+ force feature enabled). The "BLOCKED" page adapts to the available screen
+ space -- it displays full-blown if space allows, or miniaturized and
+ text-only if loaded into a small frame or window. If you are using Privoxy
+ right now, you can take a look at the "BLOCKED" page.
+
+ 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.
+
+ 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} # 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
+
+-------------------------------------------------------------------------------
+
+8.5.3. 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.
+
+Example usage:
+
+ +crunch-incoming-cookies
+
+-------------------------------------------------------------------------------
+
+8.5.4. 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:
+
+ +crunch-outgoing-cookies
+
+-------------------------------------------------------------------------------
+
+8.5.5. 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:
+
+ +deanimate-gifs{last}
+
+-------------------------------------------------------------------------------
+
+8.5.6. 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
+
+-------------------------------------------------------------------------------
+
+8.5.7. fast-redirects
+
+Typical use:
+
+ Fool some click-tracking scripts and speed up indirect links
+
+Effect:
+
+ Cut off all but the last valid URL from requests.
+
+Type:
+
+ Boolean.
+
+Parameter:
+
+ N/A
+
+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://some.place/click-tracker.cgi?
+ target=http://some.where.else.
+
+ 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.
+
+ 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 default.action.
+ Some sites just don't work without it.
+
+Example usage:
+
+ {+fast-redirects}
+
+-------------------------------------------------------------------------------
+
+8.5.8. filter
+
+Typical use:
+
+ Get rid of HTML and JavaScript annoyances, banner advertisements (by size),
+ do fun text replacements, etc.
+
+Effect:
+
+ Text documents, including HTML and JavaScript, to which this action
+ applies, are filtered on-the-fly through the specified regular expression
+ based substitutions.
+
+Type:
+
+ Parameterized.
+
+Parameter:
+
+ The name of a filter, as defined in the filter file (typically
+ default.filter, set by the filterfile option in the config file)
+
+Notes:
+
+ For your convenience, there are a bunch of pre-defined filters available in
+ the distribution filter file that you can use. See the example below for a
+ list.
+
+ 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.
+
+ 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 effects as the block action, i.e. it can
+ be used to block ads and banners.
+
+ Feedback with suggestions for new or improved filters is particularly
+ welcome!
+
+Example usage (with filters from the distribution default.filter file):
+
+ +filter{html-annoyances} # Get rid of particularly annoying HTML abuse.
+
+ +filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse
+
+ +filter{banners-by-size} # Kill banners by size (very efficient!)
+
+ +filter{content-cookies} # Kill cookies that come sneaking in the HTML or JS content
+
+ +filter{popups} # Kill all popups in JS and HTML
+
+ +filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking)
+
+ +filter{fun} # Text replacements for subversive browsing fun!
+
+ +filter{frameset-borders} # Give frames a border and make them resizeable
+
+ +filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups)
+
+ +filter{nimda} # Remove Nimda (virus) code.
+
+ +filter{shockwave-flash} # Kill embedded Shockwave Flash objects
+
+ +filter{crude-parental} # Kill all web pages that contain the words "sex" or "warez"
+
+-------------------------------------------------------------------------------
+
+8.5.9. handle-as-image
+
+Typical use:
+
+ Mark URLs as belonging to images (so they'll be replaced by images 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, (inline) 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)$
+
+ # 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
+
+-------------------------------------------------------------------------------
+
+8.5.10. 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
+
+-------------------------------------------------------------------------------
+
+8.5.11. 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:
+
+ +hide-from-header{block}
+
+ or
+
+ +hide-from-header{spam-me-senseless@sittingduck.example.com}
+
+-------------------------------------------------------------------------------
+
+8.5.12. 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:
+
+ + "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.
+
+Notes:
+
+ "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).
+
+ 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/}
+
+-------------------------------------------------------------------------------
+
+8.5.13. 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 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 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)}
+
+-------------------------------------------------------------------------------
+
+8.5.14. kill-popups
+
+Typical use:
+
+ Eliminate those annoying pop-up windows
+
+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 easily confused with the built-in, hardwired 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{popups} does.
+
+ 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 it's filter equivalent.
+
+ 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
+ filter{js-annoyances} instead.
+
+Example usage:
+
+ +kill-popups
+
+-------------------------------------------------------------------------------
+
+8.5.15. limit-connect
+
+Typical use:
+
+ Prevent abuse of Privoxy as a TCP proxy relay
+
+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.
+
+ 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.
+
+Example usages:
+
+ +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!)
+
+-------------------------------------------------------------------------------
+
+8.5.16. prevent-compression
+
+Typical use:
+
+ Ensure that servers send the content uncompressed, so it can be passed
+ through filters
+
+Effect:
+
+ Adds a header to the request that asks for uncompressed 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:
+ #
+ {+prevent-compression}
+ / # Match all sites
+
+ # Make exceptions for ill sites:
+ #
+ {-prevent-compression}
+ www.debianhelp.org
+ www.pclinuxonline.com
+
+-------------------------------------------------------------------------------
+
+8.5.17. 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:
+
+ +send-vanilla-wafer
+
+-------------------------------------------------------------------------------
+
+8.5.18. 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
+
+-------------------------------------------------------------------------------
+
+8.5.19. 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.
+
+Example usage:
+
+ +session-cookies-only
+
+-------------------------------------------------------------------------------
+
+8.5.20. 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).
+
+ 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}
+
+-------------------------------------------------------------------------------
+
+8.5.21. 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.
+ #
+ # Note the (required!) section header line and that this section
+ # must be at the top of the actions file!
+ #
+ {{alias}}
+
+ # These aliases just save typing later:
+ #
+ +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies
+ -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies
+ +imageblock = +block +handle-as-image
+
+ # 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 -fast-redirects
+
+ # Aliases defined from other aliases, for really lazy people ;-)
+ #
+ c0 = +crunch-all-cookies
+ 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
+
+ # Shopping sites:
+ # Allow cookies (for setting and retrieving your customer data)
+ #
+ {shop}
+ .quietpc.com
+ .worldpay.com # for quietpc.com
+ .scan.co.uk
+
+ # These shops require pop-ups:
+ #
+ {shop -kill-popups -filter{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. Sample Actions Files
+
+Remember that the meaning of each action is reversed by preceding the action
+with a "-", in place of the "+". Also, that some actions are turned on in the
+default section of the actions file, and require little to no additional
+configuration. These are just "on".
+
+But, other actions that are turned on in the default section do typically
+require exceptions to be listed in the latter sections of one of our actions
+file. For instance, by default no URLs are "blocked" (i.e. in the default
+definitions of default.action). We need exceptions to this in order to enable
+ad blocking in the lower sections. But we need to be very selective about what
+we do block. Thus, the default is "off" for blocking.
+
+Below is a liberally commented sample default.action file to demonstrate how
+all the pieces come together. And to show how exceptions to the default
+policies can be handled. This is followed by a brief user.action with similar
+examples.
+
+# Sample default.action file <developers@privoxy.org>
+
+# Settings -- Don't change! For internal Privoxy use ONLY.
+{{settings}}
+for-privoxy-version=3.0
+
+
+##########################################################################
+# Aliases must be defined *before* they are used. These are
+# easier to remember, and can combine several actions into one. Once
+# defined they can be used just like any built-in action -- but within
+# this file only! Aliases do not require a + or - sign.
+##########################################################################
+{{alias}}
+
+# Some useful aliases.
+# Alias to turn off cookie handling, ie allow all cookies unmolested.
+#
+mercy-for-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies \
+ -session-cookies-only
+
+# Alias to both block and treat as if an image for ad blocking
+# purposes.
+#
++block-as-image = +block +handle-as-image
+
+# Shops should be allowed to set persistent cookies
+#
+shop = -filter mercy-for-cookies
+
+# Fragile sites should receive minimum interference:
+#
+fragile = -block -deanimate-gifs -fast-redirects -filter -hide-referer \
+ mercy-for-cookies -kill-popups
+
+##########################################################################
+# Matching starts here. Remember that at this time, all actions are
+# disabled, so we need to explicitly enable the ones we want.
+#
+# We begin with "default" action settings, i.e. we define a set of actions
+# for a pattern ("/") that matches all URLs. This default set will be
+# applied to all requests as a start, and can be partly or wholly overridden
+# by later matches further down this file, or in user.action.
+#
+# We will show all potential actions here whether they are enabled
+# or not. We could omit any disabled action if we wanted, since all
+# actions are 'off' by default anyway. Shown for completeness only.
+# Actions are enabled if preceded by a '+', otherwise they are disabled
+# (unless an alias has been defined without this).
+##########################################################################
+ { \
+ -add-header \
+ -block \
+ -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{banners-by-size} \
+ -filter{shockwave-flash} \
+ -filter{crude-parental} \
+ +hide-forwarded-for-headers \
+ +hide-from-header{block} \
+ -hide-referrer \
+ -hide-user-agent \
+ -handle-as-image \
+ +set-image-blocker{pattern} \
+ -limit-connect \
+ +prevent-compression \
+ -session-cookies-only \
+ -crunch-outgoing-cookies \
+ -crunch-incoming-cookies \
+ -kill-popups \
+ -send-vanilla-wafer \
+ -send-wafer \
+ }
+ / # forward slash will match *all* potential URL patterns.
+
+##########################################################################
+# Default behavior is now set. Now we will define some exceptions to our
+# default action policies.
+##########################################################################
+
+# These sites are very complex and require very minimal interference.
+# We'll disable most actions with our 'fragile' alias:
+ { fragile }
+ .office.microsoft.com # surprise, surprise!
+ .windowsupdate.microsoft.com
+
+
+# Shopping sites - not as fragile but require some special
+# handling. We still want to block ads, and we will allow
+# persistent cookies via the 'shop' alias:
+ { shop }
+ .quietpc.com
+ .worldpay.com # for quietpc.com
+ .jungle.com
+ .scan.co.uk
+
+
+# These sites require pop-ups too :( We'll combine our 'shop'
+# alias with two other actions into one rule to allow all popups.
+ { shop -kill-popups -filter{popups} }
+ .dabs.com
+ .overclockers.co.uk
+
+
+# The 'Fast-redirects' action breaks some sites. Disable this action
+# for these known sensitive sites:
+ { -fast-redirects }
+ login.yahoo.com
+ edit.europe.yahoo.com
+ .google.com
+ .altavista.com/.*(like|url|link):http
+ .altavista.com/trans.*urltext=http
+ .nytimes.com
+
+
+# Define which file types will be treated as images. Important
+# for ad blocking.
+ { +handle-as-image }
+ /.*\.(gif|jpe?g|png|bmp|ico)
+
+
+# Now lets list some domains that are known ad generators. And
+# our alias that we use here will block these as well as force
+# them to be treated as images. This combination of actions is
+# important for ad blocking. What the browser will show instead is
+# determined by the setting of "+set-image-blocker"
+ { +imageblock }
+ ar.atwola.com
+ .ad.doubleclick.net
+ .a.yimg.com/(?:(?!/i/).)*$
+ .a[0-9].yimg.com/(?:(?!/i/).)*$
+ bs*.gsanet.com
+ bs*.einets.com
+ .qkimg.net
+ ad.*.doubleclick.net
+
+
+# These will just simply be blocked. They will generate the BLOCKED
+# banner page, if matched. Heavy use of wildcards and regular
+# expressions in this example. Enable block action:
+ { +block }
+ ad*.
+ .*ads.
+ banner?.
+ count*.
+ /.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?)
+ /(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/
+ .hitbox.com
+
+
+# The above block section will probably inadvertently catch some
+# sites we DO NOT want blocked via the wildcards and regular expressions.
+# Now let's set exceptions to the exceptions so the good guys get better
+# treatment. Disable block action:
+ { -block }
+ advogato.org
+ adsl.
+ ad[ud]*.
+ advice.
+# Let's just trust all .edu top level domains.
+ .edu
+ www.ugu.com/sui/ugu/adv
+# We'll need to access to path names containing 'download'
+ .*downloads.
+ /downloads/
+# 'adv' is for globalintersec and means advanced, not advertisement
+ www.globalintersec.com/adv
+
+
+# Don't filter *anything* from our friends at sourceforge.
+# Notice we don't have to name the individual filter
+# identifiers -- we just turn them all off in one fell swoop.
+# Disable all filters for this one site:
+ { -filter }
+ .sourceforge.net
+
+
+So far we are painting with a broad brush by setting general policies. The
+above would be a reasonable starting point for many situations. Now, we want to
+be more specific and have customized rules that are more suitable to our
+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 should not be clobbered by upgrades.
+So any settings here, will have the last word and over-ride any previously
+defined actions.
+
+Now a few examples of some things that one might do with a user.action file.
+
+# Sample user.action file.
+
+# Any aliases you want to use need to be re-defined here.
+# Alias to turn off cookie handling, ie allow all cookies unmolested.
+ -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies \
+ -session-cookies-only
+
+# Fragile sites should have the minimum changes:
+ fragile = -block -deanimate-gifs -fast-redirects -filter -hide-referer \
+ -crunch-all-cookies -kill-popups
+
+# Allow persistent cookies for a few regular sites that we
+# trust via our above alias. These will be saved from one browser session
+# to the next. We are explicitly turning off any and all cookie handling,
+# even though the crunch-*-cookies settings were disabled in our above
+# default.action anyway. So cookies from these domains will come through
+# unmolested.
+ { -crunch-all-cookies }
+ .sun.com
+ .yahoo.com
+ .msdn.microsoft.com
+ .redhat.com
+
+
+# My ISP uses obnoxious self promoting images on many pages.
+# Nuke them :) Note that "+handle-as-image" need not be specified,
+# since all URLs ending in .gif will be tagged as images by the
+# general rules in default.action anyway.
+ { +block }
+ www.my-isp-example.com/logo[0-9].gif
+
+
+# Say the site where you do your home banking needs to open
+# popup windows, but you have chosen to kill popups by
+# default. This will allow it for your-example-bank.com:
+#
+ { -filter{popups} -kill-popups }
+ .my-example-bank.com
+
+
+# This site is delicate, and requires kid-glove
+# treatment.
+ { fragile }
+ .forbes.com
+
+
+-------------------------------------------------------------------------------
+
+9. The Filter File
+
+Any web page can be dynamically modified with the filter file. This
+modification can be removal, or re-writing, of any web page content, including
+tags and non-visible content. The default filter file is oddly enough
+default.filter, located in the config directory.
+
+This is potentially a very powerful feature, and requires knowledge of both
+"regular expression" and HTML in order create custom filters. But, there are a
+number of useful filters included with Privoxy for many common situations.
+
+The included example file is divided into sections. Each section begins with
+the FILTER keyword, followed by the identifier for that section, e.g. "FILTER:
+webbugs". Each section performs a similar type of filtering, such as
+"html-annoyances".
+
+This file uses regular expressions to alter or remove any string in the target
+page. The expressions can only operate on one line at a time. Some examples
+from the included default default.filter:
+
+Stop web pages from displaying annoying messages in the status bar by deleting
+such references:
+
+ FILTER: html-annoyances
+
+ # New browser windows should be resizeable and have a location and status
+ # bar. Make it so.
+ #
+ s/resizable="?(no|0)"?/resizable=1/ig s/noresize/yesresize/ig
+ s/location="?(no|0)"?/location=1/ig s/status="?(no|0)"?/status=1/ig
+ s/scrolling="?(no|0|Auto)"?/scrolling=1/ig
+ s/menubar="?(no|0)"?/menubar=1/ig
+
+ # The <BLINK> tag was a crime!
+ #
+ s*<blink>|</blink>**ig
+
+ # Is this evil?
+ #
+ #s/framespacing="?(no|0)"?//ig
+ #s/margin(height|width)=[0-9]*//gi
+
+
+Just for kicks, replace any occurrence of "Microsoft" with "MicroSuck", and
+have a little fun with topical buzzwords:
+
+ FILTER: fun
+
+ s/microsoft(?!.com)/MicroSuck/ig
+
+ # Buzzword Bingo:
+ #
+ s/industry-leading|cutting-edge|award-winning/<font color=red><b>BINGO!</b></
+font>/ig
+
+
+Kill those pesky little web-bugs:
+
+ # webbugs: Squish WebBugs (1x1 invisible GIFs used for user tracking)
+ FILTER: webbugs
+
+ s/<img\s+[^>]*?(width|height)\s*=\s*['"]?1\D[^>]*?(width|height)\s*=\s*['"]?1
+(\D[^>]*?)?>/<!-- Squished WebBug -->/sig
+
+
+-------------------------------------------------------------------------------
+
+9.1. The +filter Action
+
+Filters are enabled with the "+filter" action from within one of the actions
+files. "+filter" requires one parameter, which should match one of the section
+identifiers in the filter file itself. Example:
+
+ +filter{html-annoyances}
+
+This would activate that particular filter. Similarly, "+filter" can be turned
+off for selected sites as: "-filter{html-annoyances}". Remember too, all
+actions are off by default, unless they are explicitly enabled in one of the
+actions files.
+
+-------------------------------------------------------------------------------
+
+10. Templates
+
+When Privoxy displays one of its internal pages, such as a 404 Not Found error
+page (Privoxy must be running for link to work as intended), it uses the
+appropriate template. On Linux, BSD, and Unix, these are located in /etc/
+privoxy/templates by default. These may be customized, if desired.
+cgi-style.css is used to control the HTML attributes (fonts, etc).
+
+The default Blocked (Privoxy needs to be running for page to display) banner
+page with the bright red top banner, is called just "blocked". This may be
+customized or replaced with something else if desired (not recommended for the
+casual user).
+
+-------------------------------------------------------------------------------
+
+11. Contacting the Developers, Bug Reporting and Feature Requests
+
+We value your feedback. However, to provide you with the best support, please
+note the following sections.
+
+-------------------------------------------------------------------------------
+
+11.1. Get Support
+
+To get support, use the Sourceforge Support Forum:
+
+ http://sourceforge.net/tracker/?group_id=11118&atid=211118
+
+-------------------------------------------------------------------------------
+
+11.2. Report bugs
+
+To submit bugs, use the Sourceforge Bug Forum:
+
+ http://sourceforge.net/tracker/?group_id=11118&atid=111118.
+
+Make sure that the bug has not already been submitted. Please try to verify
+that it is a Privoxy bug, and not a browser or site bug first. If you are using
+your own custom configuration, please try the stock configs to see if the
+problem is a configuration related bug. And if not using the latest development
+snapshot, please try the latest one. Or even better, CVS sources. Please be
+sure to include the Privoxy version, platform, browser, any pertinent log data,
+any other relevant details (please be specific) and, if possible, some way to
+reproduce the bug.
+
+-------------------------------------------------------------------------------
+
+11.3. Request new features
+
+To submit ideas on new features, use the Sourceforge feature request forum:
+
+ http://sourceforge.net/tracker/?atid=361118&group_id=11118&func=browse.
+
+-------------------------------------------------------------------------------
+
+11.4. Report ads or other filter problems
+
+You can also send feedback on websites that Privoxy has problems with. Please
+bookmark the following link: "Privoxy - Submit Filter Feedback". Once you surf
+to a page with problems, use the bookmark to send us feedback. We will look
+into the issue as soon as possible.
+
+New, improved default.action files will occasionally be made available based on
+your feedback. These will be announced on the ijbswa-announce list.
+
+-------------------------------------------------------------------------------
+
+11.5. Other
+
+For any other issues, feel free to use the mailing lists:
+
+ http://sourceforge.net/mail/?group_id=11118.
+
+Anyone interested in actively participating in development and related
+discussions can also join the appropriate mailing list. Archives are available,
+too. See the page on Sourceforge.
+
+-------------------------------------------------------------------------------
+
+12. Privoxy Copyright, License and History
+
+Copyright © 2001, 2002 by Privoxy Developers <developers@privoxy.org>
+
+Some source code is based on code Copyright © 1997 by Anonymous Coders and
+Junkbusters, Inc. and licensed under the GNU General Public License.
+
+-------------------------------------------------------------------------------
+
+12.1. License
+
+Privoxy is free software; you can redistribute it and/or modify it under the
+terms of the GNU General Public License, version 2, as published by the Free
+Software Foundation.
+
+This program is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+PARTICULAR PURPOSE. See the GNU General Public License for more details, which
+is available from the Free Software Foundation, Inc, 59 Temple Place - Suite
+330, Boston, MA 02111-1307, USA.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the
+
+ Free Software
+ Foundation, Inc. 59 Temple Place - Suite 330
+ Boston, MA 02111-1307
+ USA
+
+-------------------------------------------------------------------------------
+
+12.2. History
+
+Privoxy is evolved, and derived from, the Internet Junkbuster, with many
+improvements and enhancements over the original.
+
+Junkbuster was originally written by Anonymous Coders and Junkbusters
+Corporation, and was released as free open-source software under the GNU GPL.
+Stefan Waldherr made many improvements, and started the SourceForge project
+Privoxy to rekindle development. There are now several active developers
+contributing. The last stable release of Junkbuster was v2.0.2, which has now
+grown whiskers ;-).
+
+-------------------------------------------------------------------------------
+
+13. See Also
+
+Other references and sites of interest to Privoxy users:
+
+http://www.privoxy.org/, The Privoxy Home page.
+
+http://sourceforge.net/projects/ijbswa, the Project Page for Privoxy on
+Sourceforge.
+
+http://p.p/, access Privoxy from your browser. Alternately, http://
+config.privoxy.org may work in some situations where the first does not.
+
+http://p.p/, and select "Privoxy - Submit Filter Feedback" to submit "misses"
+to the developers.
+
+http://www.junkbusters.com/ht/en/cookies.html
+
+http://www.waldherr.org/junkbuster/
+
+http://privacy.net/analyze/
+
+http://www.squid-cache.org/
+
+
+
+-------------------------------------------------------------------------------
+
+14. Appendix
+
+14.1. Regular Expressions
+
+Privoxy can use "regular expressions" in various config files. Assuming support
+for "pcre" (Perl Compatible Regular Expressions) is compiled in, which is the
+default. Such configuration directives do not require regular expressions, but
+they can be used to increase flexibility by matching a pattern with wild-cards
+against URLs.
+
+If you are reading this, you probably don't understand what "regular
+expressions" are, or what they can do. So this will be a very brief
+introduction only. A full explanation would require a book ;-)
+
+"Regular expressions" is a way of matching one character expression against
+another to see if it matches or not. One of the "expressions" is a literal
+string of readable characters (letter, numbers, etc), and the other is a
+complex string of literal characters combined with wild-cards, and other
+special characters, called meta-characters. The "meta-characters" have special
+meanings and are used to build the complex pattern to be matched against. Perl
+Compatible Regular Expressions is an enhanced form of the regular expression
+language with backward compatibility.
+
+To make a simple analogy, we do something similar when we use wild-card
+characters when listing files with the dir command in DOS. *.* matches all
+filenames. The "special" character here is the asterisk which matches any and
+all characters. We can be more specific and use ? to match just individual
+characters. So "dir file?.text" would match "file1.txt", "file2.txt", etc. We
+are pattern matching, using a similar technique to "regular expressions"!
+
+Regular expressions do essentially the same thing, but are much, much more
+powerful. There are many more "special characters" and ways of building complex
+patterns however. Let's look at a few of the common ones, and then some
+examples:
+
+. - Matches any single character, e.g. "a", "A", "4", ":", or "@".
+
+? - The preceding character or expression is matched ZERO or ONE times. Either/
+or.
+
++ - The preceding character or expression is matched ONE or MORE times.
+
+* - The preceding character or expression is matched ZERO or MORE times.
+
+\ - The "escape" character denotes that the following character should be taken
+literally. This is used where one of the special characters (e.g. ".") needs to
+be taken literally and not as a special meta-character. Example: "example
+\.com", makes sure the period is recognized only as a period (and not expanded
+to its meta-character meaning of any single character).
+
+[] - Characters enclosed in brackets will be matched if any of the enclosed
+characters are encountered. For instance, "[0-9]" matches any numeric digit
+(zero through nine). As an example, we can combine this with "+" to match any
+digit one of more times: "[0-9]+".
+
+() - parentheses are used to group a sub-expression, or multiple
+sub-expressions.
+
+| - The "bar" character works like an "or" conditional statement. A match is
+successful if the sub-expression on either side of "|" matches. As an example:
+"/(this|that) example/" uses grouping and the bar character and would match
+either "this example" or "that example", and nothing else.
+
+s/string1/string2/g - This is used to rewrite strings of text. "string1" is
+replaced by "string2" in this example. There must of course be a match on
+"string1" first.
+
+These are just some of the ones you are likely to use when matching URLs with
+Privoxy, and is a long way from a definitive list. This is enough to get us
+started with a few simple examples which may be more illuminating:
+
+/.*/banners/.* - A simple example that uses the common combination of "." and "
+*" to denote any character, zero or more times. In other words, any string at
+all. So we start with a literal forward slash, then our regular expression
+pattern (".*") another literal forward slash, the string "banners", another
+forward slash, and lastly another ".*". We are building a directory path here.
+This will match any file with the path that has a directory named "banners" in
+it. The ".*" matches any characters, and this could conceivably be more forward
+slashes, so it might expand into a much longer looking path. For example, this
+could match: "/eye/hate/spammers/banners/annoy_me_please.gif", or just "/
+banners/annoying.html", or almost an infinite number of other possible
+combinations, just so it has "banners" in the path somewhere.
+
+A now something a little more complex:
+
+/.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward
+slashes again ("/"), so we are building another expression that is a file path
+statement. We have another ".*", so we are matching against any conceivable
+sub-path, just so it matches our expression. The only true literal that must
+match our pattern is adv, together with the forward slashes. What comes after
+the "adv" string is the interesting part.
+
+Remember the "?" means the preceding expression (either a literal character or
+anything grouped with "(...)" in this case) can exist or not, since this means
+either zero or one match. So "((er)?ts?|ertis(ing|ements?))" is optional, as
+are the individual sub-expressions: "(er)", "(ing|ements?)", and the "s". The "
+|" means "or". We have two of those. For instance, "(ing|ements?)", can expand
+to match either "ing" OR "ements?". What is being done here, is an attempt at
+matching as many variations of "advertisement", and similar, as possible. So
+this would expand to match just "adv", or "advert", or "adverts", or
+"advertising", or "advertisement", or "advertisements". You get the idea. But
+it would not match "advertizements" (with a "z"). We could fix that by changing
+our regular expression to: "/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/", which
+would then match either spelling.
+
+/.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward
+slashes. Anything in the square brackets "[]" can be matched. This is using
+"0-9" as a shorthand expression to mean any digit one through nine. It is the
+same as saying "0123456789". So any digit matches. The "+" means one or more of
+the preceding expression must be included. The preceding expression here is
+what is in the square brackets -- in this case, any digit one through nine.
+Then, at the end, we have a grouping: "(gif|jpe?g)". This includes a "|", so
+this needs to match the expression on either side of that bar character also. A
+simple "gif" on one side, and the other side will in turn match either "jpeg"
+or "jpg", since the "?" means the letter "e" is optional and can be matched
+once or not at all. So we are building an expression here to match image GIF or
+JPEG type image file. It must include the literal string "advert", then one or
+more digits, and a "." (which is now a literal, and not a special character,
+since it is escaped with "\"), and lastly either "gif", or "jpeg", or "jpg".
+Some possible matches would include: "//advert1.jpg", "/nasty/ads/
+advert1234.gif", "/banners/from/hell/advert99.jpg". It would not match
+"advert1.gif" (no leading slash), or "/adverts232.jpg" (the expression does not
+include an "s"), or "/advert1.jsp" ("jsp" is not in the expression anywhere).
+
+s/microsoft(?!.com)/MicroSuck/i - This is a substitution. "MicroSuck" will
+replace any occurrence of "microsoft". The "i" at the end of the expression
+means ignore case. The "(?!.com)" means the match should fail if "microsoft" is
+followed by ".com". In other words, this acts like a "NOT" modifier. In case
+this is a hyperlink, we don't want to break it ;-).
+
+We are barely scratching the surface of regular expressions here so that you
+can understand the default Privoxy configuration files, and maybe use this
+knowledge to customize your own installation. There is much, much more that can
+be done with regular expressions. Now that you know enough to get started, you
+can learn more on your own :/
+
+More reading on Perl Compatible Regular expressions: http://www.perldoc.com/
+perl5.6/pod/perlre.html
+
+-------------------------------------------------------------------------------
+
+14.2. Privoxy's Internal Pages
+
+Since Privoxy proxies each requested web page, it is easy for Privoxy to trap
+certain special URLs. In this way, we can talk directly to Privoxy, and see how
+it is configured, see how our rules are being applied, change these rules and
+other configuration options, and even turn Privoxy's filtering off, all with a
+web browser.
+
+The URLs listed below are the special ones that allow direct access to Privoxy.
+Of course, Privoxy must be running to access these. If not, you will get a
+friendly error message. Internet access is not necessary either.
+
+ * Privoxy main page:
+
+ http://config.privoxy.org/
+
+ Alternately, this may be reached at http://p.p/, but this variation may not
+ work as reliably as the above in some configurations.
+
+ * Show information about the current configuration, including viewing and
+ editing of actions files:
+
+ http://config.privoxy.org/show-status
+
+ * Show the source code version numbers:
+
+ http://config.privoxy.org/show-version
+
+ * Show the browser's request headers:
+
+ http://config.privoxy.org/show-request
+
+ * Show which actions apply to a URL and why:
+
+ http://config.privoxy.org/show-url-info
+
+ * Toggle Privoxy on or off. In this case, "Privoxy" continues to run, but
+ only as a pass-through proxy, with no actions taking place:
+
+ http://config.privoxy.org/toggle
+
+ Short cuts. Turn off, then on:
+
+ http://config.privoxy.org/toggle?set=disable
+
+ http://config.privoxy.org/toggle?set=enable
+
+These may be bookmarked for quick reference. See next.
+
+-------------------------------------------------------------------------------
+
+14.2.1. Bookmarklets
+
+Below are some "bookmarklets" to allow you to easily access a "mini" version of
+some of Privoxy's special pages. They are designed for MS Internet Explorer,
+but should work equally well in Netscape, Mozilla, and other browsers which
+support JavaScript. They are designed to run directly from your bookmarks - not
+by clicking the links below (although that should work for testing).
+
+To save them, right-click the link and choose "Add to Favorites" (IE) or "Add
+Bookmark" (Netscape). You will get a warning that the bookmark "may not be
+safe" - just click OK. Then you can run the Bookmarklet directly from your
+favorites/bookmarks. For even faster access, you can put them on the "Links"
+bar (IE) or the "Personal Toolbar" (Netscape), and run them with a single
+click.
+
+ * Privoxy - Enable
+
+ * Privoxy - Disable
+
+ * Privoxy - Toggle Privoxy (Toggles between enabled and disabled)
+
+ * Privoxy- View Status
+
+ * Privoxy - Submit Filter Feedback
+
+Credit: The site which gave me the general idea for these bookmarklets is
+www.bookmarklets.com. They have more information about bookmarklets.
+
+-------------------------------------------------------------------------------
+
+14.3. Chain of Events
+
+Let's take a quick look at the basic sequence of events when a web page is
+requested by your browser and Privoxy is on duty:
+
+ * First, your web browser requests a web page. The browser knows to send the
+ request to Privoxy, which will in turn, relay the request to the remote web
+ server after passing the following tests:
+
+ * Privoxy traps any request for its own internal CGI pages (e.g http://p.p/)
+ and sends the CGI page back to the browser.
+
+ * Next, Privoxy checks to see if the URL matches any "+block" patterns. If
+ so, the URL is then blocked, and the remote web server will not be
+ contacted. "+handle-as-image" is then checked and if it does not match, an
+ HTML "BLOCKED" page is sent back. Otherwise, if it does match, an image is
+ returned. The type of image depends on the setting of "+set-image-blocker"
+ (blank, checkerboard pattern, or an HTTP redirect to an image elsewhere).
+
+ * Untrusted URLs are blocked. If URLs are being added to the trust file, then
+ that is done.
+
+ * If the URL pattern matches the "+fast-redirects" action, it is then
+ processed. Unwanted parts of the requested URL are stripped.
+
+ * Now the rest of the client browser's request headers are processed. If any
+ of these match any of the relevant actions (e.g. "+hide-user-agent", etc.),
+ headers are suppressed or forged as determined by these actions and their
+ parameters.
+
+ * Now the web server starts sending its response back (i.e. typically a web
+ page and related data).
+
+ * First, the server headers are read and processed to determine, among other
+ things, the MIME type (document type) and encoding. The headers are then
+ filtered as determined by the "+crunch-incoming-cookies",
+ "+session-cookies-only", and "+downgrade-http-version" actions.
+
+ * If the "+kill-popups" action applies, and it is an HTML or JavaScript
+ document, the popup-code in the response is filtered on-the-fly as it is
+ received.
+
+ * If a "+filter" or "+deanimate-gifs" action applies (and the document type
+ fits the action), the rest of the page is read into memory (up to a
+ configurable limit). Then the filter rules (from default.filter) are
+ processed against the buffered content. Filters are applied in the order
+ they are specified in the default.filter file. Animated GIFs, if present,
+ are reduced to either the first or last frame, depending on the action
+ setting.The entire page, which is now filtered, is then sent by Privoxy
+ back to your browser.
+
+ If neither "+filter" or "+deanimate-gifs" matches, then Privoxy passes the
+ raw data through to the client browser as it becomes available.
+
+ * As the browser receives the now (probably filtered) page content, it reads
+ and then requests any URLs that may be embedded within the page source,
+ e.g. ad images, stylesheets, JavaScript, other HTML documents (e.g.
+ frames), sounds, etc. For each of these objects, the browser issues a new
+ request. And each such request is in turn processed as above. Note that a
+ complex web page may have many such embedded URLs.
+
+-------------------------------------------------------------------------------
+
+14.4. Anatomy of an Action
+
+The way Privoxy applies "actions" and "filters" to any given URL can be
+complex, and not always so easy to understand what is happening. And sometimes
+we need to be able to see just what Privoxy is doing. Especially, if something
+Privoxy is doing is causing us a problem inadvertently. It can be a little
+daunting to look at the actions and filters files themselves, since they tend
+to be filled with "regular expressions" whose consequences are not always so
+obvious.
+
+One quick test to see if Privoxy is causing a problem or not, is to disable it
+temporarily. This should be the first troubleshooting step. See the
+Bookmarklets section on a quick and easy way to do this (be sure to flush
+caches afterward!).
+
+Privoxy also provides the http://config.privoxy.org/show-url-info page that can
+show us very specifically how actions are being applied to any given URL. This
+is a big help for troubleshooting.
+
+First, enter one URL (or partial URL) at the prompt, and then Privoxy will tell
+us how the current configuration will handle it. This will not help with
+filtering effects (i.e. the "+filter" action) from the default.filter file
+since this is handled very differently and not so easy to trap! It also will
+not tell you about any other URLs that may be embedded within the URL you are
+testing. For instance, images such as ads are expressed as URLs within the raw
+page source of HTML pages. So you will only get info for the actual URL that is
+pasted into the prompt area -- not any sub-URLs. If you want to know about
+embedded URLs like ads, you will have to dig those out of the HTML source. Use
+your browser's "View Page Source" option for this. Or right click on the ad,
+and grab the URL.
+
+Let's try an example, google.com, and look at it one section at a time:
+
+ Matches for http://google.com:
+
+--- File standard ---
+(no matches in this file)
+
+--- File default ---
+
+{ -add-header -block +deanimate-gifs{last} -downgrade-http-version +fast-redirects
+ -filter{popups} -filter{fun} -filter{shockwave-flash} -filter{crude-parental}
+ +filter{html-annoyances} +filter{js-annoyances} +filter{content-cookies}
+ +filter{webbugs} +filter{refresh-tags} +filter{nimda} +filter{banners-by-size}
+ +hide-forwarded-for-headers +hide-from-header{block} +hide-referer{forge}
+ -hide-user-agent -handle-as-image +set-image-blocker{pattern} -limit-connect
+ +prevent-compression +session-cookies-only -crunch-outgoing-cookies
+ -crunch-incoming-cookies -kill-popups -send-vanilla-wafer -send-wafer }
+/
+
+ { -session-cookies-only }
+ .google.com
+
+ { -fast-redirects }
+ .google.com
+
+--- File user ---
+(no matches in this file)
+
+This tells us how we have defined our "actions", and which ones match for our
+example, "google.com". The first listing is any matches for the standard.action
+file. No hits at all here on "standard". Then next is "default", or our
+default.action file. The large, multi-line listing, is how the actions are set
+to match for all URLs, i.e. our default settings. If you look at your "actions"
+file, this would be the section just below the "aliases" section near the top.
+This will apply to all URLs as signified by the single forward slash at the end
+of the listing -- "/".
+
+But we can define additional actions that would be exceptions to these general
+rules, and then list specific URLs (or patterns) that these exceptions would
+apply to. Last match wins. Just below this then are two explicit matches for
+".google.com". The first is negating our previous cookie setting, which was for
+"+session-cookies-only" (i.e. not persistent). So we will allow persistent
+cookies for google. The second turns off any "+fast-redirects" action, allowing
+this to take place unmolested. Note that there is a leading dot here --
+".google.com". This will match any hosts and sub-domains, in the google.com
+domain also, such as "www.google.com". So, apparently, we have these two
+actions defined somewhere in the lower part of our default.action file, and
+"google.com" is referenced somewhere in these latter sections.
+
+Then, for our user.action file, we again have no hits.
+
+And finally we pull it all together in the bottom section and summarize how
+Privoxy is applying all its "actions" to "google.com":
+
+ Final results:
+ -add-header -block +deanimate-gifs{last} -downgrade-http-version -fast-redirects
+ -filter{popups} -filter{fun} -filter{shockwave-flash} -filter{crude-parental}
+ +filter{html-annoyances} +filter{js-annoyances} +filter{content-cookies}
+ +filter{webbugs} +filter{refresh-tags} +filter{nimda} +filter{banners-by-size}
+ +hide-forwarded-for-headers +hide-from-header{block} +hide-referer{forge}
+ -hide-user-agent -handle-as-image +set-image-blocker{pattern} -limit-connect
+ +prevent-compression -session-cookies-only -crunch-outgoing-cookies
+ -crunch-incoming-cookies -kill-popups -send-vanilla-wafer -send-wafer
+
+Notice the only difference here to the previous listing, is to "fast-redirects"
+and "session-cookies-only".
+
+Now another example, "ad.doubleclick.net":
+
+ { +block +handle-as-image }
+ .ad.doubleclick.net
+
+ { +block +handle-as-image }
+ ad*.
+
+ { +block +handle-as-image }
+ .doubleclick.net
+
+We'll just show the interesting part here, the explicit matches. It is matched
+three different times. Each as an "+block +handle-as-image", which is the
+expanded form of one of our aliases that had been defined as: "+imageblock". (
+"Aliases" are defined in the first section of the actions file and typically
+used to combine more than one action.)
+
+Any one of these would have done the trick and blocked this as an unwanted
+image. This is unnecessarily redundant since the last case effectively would
+also cover the first. No point in taking chances with these guys though ;-)
+Note that if you want an ad or obnoxious URL to be invisible, it should be
+defined as "ad.doubleclick.net" is done here -- as both a "+block" and an
+"+handle-as-image". The custom alias "+imageblock" just simplifies the process
+and make it more readable.
+
+One last example. Let's try "http://www.rhapsodyk.net/adsl/HOWTO/". This one is
+giving us problems. We are getting a blank page. Hmmm...
+
+ Matches for http://www.rhapsodyk.net/adsl/HOWTO/:
+
+ { -add-header -block +deanimate-gifs -downgrade-http-version +fast-redirects
+ +filter{html-annoyances} +filter{js-annoyances} +filter{kill-popups}
+ +filter{webbugs} +filter{nimda} +filter{banners-by-size} +filter{hal}
+ +filter{fun} +hide-forwarded-for-headers +hide-from-header{block}
+ +hide-referer{forge} -hide-user-agent -handle-as-image +set-image-blocker{blank}
+ +prevent-compression +session-cookies-only -crunch-incoming-cookies
+ -crunch-outgoing-cookies +kill-popups -send-vanilla-wafer -send-wafer }
+ /
+
+ { +block +handle-as-image }
+ /ads
+
+Ooops, the "/adsl/" is matching "/ads"! But we did not want this at all! Now we
+see why we get the blank page. We could now add a new action below this that
+explicitly does not block ("{-block}") paths with "adsl". There are various
+ways to handle such exceptions. Example:
+
+ { -block }
+ /adsl
+
+Now the page displays ;-) Be sure to flush your browser's caches when making
+such changes. Or, try using Shift+Reload.
+
+But now what about a situation where we get no explicit matches like we did
+with:
+
+ { +block +handle-as-image }
+ /ads
+
+That actually was very telling and pointed us quickly to where the problem was.
+If you don't get this kind of match, then it means one of the default rules in
+the first section is causing the problem. This would require some guesswork,
+and maybe a little trial and error to isolate the offending rule. One likely
+cause would be one of the "{+filter}" actions. Try adding the URL for the site
+to one of aliases that turn off "+filter":
+
+ {shop}
+ .quietpc.com
+ .worldpay.com # for quietpc.com
+ .jungle.com
+ .scan.co.uk
+ .forbes.com
+
+"{shop}" is an "alias" that expands to "{ -filter -session-cookies-only }". Or
+you could do your own exception to negate filtering:
+
+ {-filter}
+ .forbes.com
+
+This would probably be most appropriately put in user.action, for local site
+exceptions.
+
+"{fragile}" is an alias that disables most actions. This can be used as a last
+resort for problem sites. Remember to flush caches! If this still does not
+work, you will have to go through the remaining actions one by one to find
+which one(s) is causing the problem.
+