+ When building from a source tarball, first unpack the source:
+
+ tar xzvf privoxy-3.0.8-src* [.tgz or .tar.gz]
+ cd privoxy-3.0.8
+
+ For retrieving the current CVS sources, you'll need a CVS client
+ installed. Note that sources from CVS are typically development quality,
+ and may not be stable, or well tested. To download CVS source, check the
+ Sourceforge documentation, which might give commands like:
+
+ cvs -d:pserver:anonymous@ijbswa.cvs.sourceforge.net:/cvsroot/ijbswa login
+ cvs -z3 -d:pserver:anonymous@ijbswa.cvs.sourceforge.net:/cvsroot/ijbswa co current
+ cd current
+
+ This will create a directory named current/, which will contain the source
+ tree.
+
+ You can also check out any Privoxy "branch", just exchange the current
+ name with the wanted branch name (Example: v_3_0_branch for the 3.0 cvs
+ tree).
+
+ It is also strongly recommended to not run Privoxy as root. You should
+ configure/install/run Privoxy as an unprivileged user, preferably by
+ creating a "privoxy" user and group just for this purpose. See your local
+ documentation for the correct command line to do add new users and groups
+ (something like adduser, but the command syntax may vary from platform to
+ platform).
+
+ /etc/passwd might then look like:
+
+ privoxy:*:7777:7777:privoxy proxy:/no/home:/no/shell
+
+ And then /etc/group, like:
+
+ privoxy:*:7777:
+
+ Some binary packages may do this for you.
+
+ Then, to build from either unpacked tarball or CVS source:
+
+ autoheader
+ autoconf
+ ./configure # (--help to see options)
+ make # (the make from GNU, sometimes called gmake)
+ su # Possibly required
+ make -n install # (to see where all the files will go)
+ make -s install # (to really install, -s to silence output)
+
+ Using GNU make, you can have the first four steps automatically done for
+ you by just typing:
+
+ make
+
+ in the freshly downloaded or unpacked source directory.
+
+ To build an executable with security enhanced features so that users
+ cannot easily bypass the proxy (e.g. "Go There Anyway"), or alter their
+ own configurations, configure like this:
+
+ ./configure --disable-toggle --disable-editor --disable-force
+
+ Then build as above. In Privoxy 3.0.7 and later, all of these options can
+ also be disabled through the configuration file.
+
+ WARNING: If installing as root, the install will fail unless a non-root
+ user or group is specified, or a privoxy user and group already exist on
+ the system. If a non-root user is specified, and no group, then the
+ installation will try to also use a group of the same name as "user". If a
+ group is specified (and no user), then the support files will be installed
+ as writable by that group, and owned by the user running the installation.
+
+ configure accepts --with-user and --with-group options for setting user
+ and group ownership of the configuration files (which need to be writable
+ by the daemon). The specified user must already exist. When starting
+ Privoxy, it must be run as this same user to insure write access to
+ configuration and log files!
+
+ Alternately, you can specify user and group on the make command line, but
+ be sure both already exist:
+
+ make -s install USER=privoxy GROUP=privoxy
+
+ The default installation path for make install is /usr/local. This may of
+ course be customized with the various ./configure path options. If you are
+ doing an install to anywhere besides /usr/local, be sure to set the
+ appropriate paths with the correct configure options (./configure --help).
+ Non-privileged users must of course have write access permissions to
+ wherever the target installation is going.
+
+ If you do install to /usr/local, the install will use
+ sysconfdir=$prefix/etc/privoxy by default. All other destinations, and the
+ direct usage of --sysconfdir flag behave like normal, i.e. will not add
+ the extra privoxy directory. This is for a safer install, as there may
+ already exist another program that uses a file with the "config" name, and
+ thus makes /usr/local/etc cleaner.
+
+ If installing to /usr/local, the documentation will go by default to
+ $prefix/share/doc. But if this directory doesn't exist, it will then try
+ $prefix/doc and install there before creating a new $prefix/share/doc just
+ for Privoxy.
+
+ Again, if the installs goes to /usr/local, the localstatedir (ie: var/)
+ will default to /var instead of $prefix/var so the logs will go to
+ /var/log/privoxy/, and the pid file will be created in
+ /var/run/privoxy.pid.
+
+ make install will attempt to set the correct values in config (main
+ configuration file). You should check this to make sure all values are
+ correct. If appropriate, an init script will be installed, but it is up to
+ the user to determine how and where to start Privoxy. The init script
+ should be checked for correct paths and values, if anything other than a
+ default install is done.
+
+ If install finds previous versions of local configuration files, most of
+ these will not be overwritten, and the new ones will be installed with a
+ "new" extension. default.action, default.filter, and standard.action will
+ be overwritten. You will then need to manually update the other installed
+ configuration files as needed. The default template files will be
+ overwritten. If you have customized, local templates, these should be
+ stored safely in a separate directory and defined in config by the
+ "templdir" directive. It is of course wise to always back-up any important
+ configuration files "just in case". If a previous version of Privoxy is
+ already running, you will have to restart it manually.
+
+ For more detailed instructions on how to build Redhat RPMs, Windows
+ self-extracting installers, building on platforms with special
+ requirements etc, please consult the developer manual.
+
+ --------------------------------------------------------------------------
+
+ 2.3. Keeping your Installation Up-to-Date
+
+ As user feedback comes in and development continues, we will make updated
+ versions of both the main actions file (as a separate package) and the
+ software itself (including the actions file) available for download.
+
+ If you wish to receive an email notification whenever we release updates
+ of Privoxy or the actions file, subscribe to our announce mailing list,
+ ijbswa-announce@lists.sourceforge.net.
+
+ In order not to lose your personal changes and adjustments when updating
+ to the latest default.action file we strongly recommend that you use
+ user.action and user.filter for your local customizations of Privoxy. See
+ the Chapter on actions files for details.
+
+ --------------------------------------------------------------------------
+
+3. What's New in this Release
+
+ There are many improvements and new features since Privoxy 3.0.6, the last
+ stable release:
+
+ * Two new actions server-header-tagger and client-header-tagger that can
+ be used to create arbitrary "tags" based on client and server headers.
+ These "tags" can then subsequently be used to control the other
+ actions used for the current request, greatly increasing Privoxy's
+ flexibility and selectivity. See tag patterns for more information on
+ tags.
+
+ * Header filtering is done with dedicated header filters now. As a
+ result the actions "filter-client-headers" and "filter-server-headers"
+ that were introduced with Privoxy 3.0.5 to apply content filters to
+ the headers have been removed. See the new actions
+ server-header-filter and client-header-filter for details.
+
+ * There are four new options for the main config file:
+
+ * allow-cgi-request-crunching which allows requests for Privoxy's
+ internal CGI pages to be blocked, redirected or (un)trusted like
+ ordinary requests.
+
+ * split-large-forms that will work around a browser bug that caused
+ IE6 and IE7 to ignore the Submit button on the Privoxy's
+ edit-actions-for-url CGI page.
+
+ * accept-intercepted-requests which allows to combine Privoxy with
+ any packet filter to create an intercepting proxy for HTTP/1.1
+ requests (and for HTTP/1.0 requests with Host header set). This
+ means clients can be forced to use Privoxy even if their proxy
+ settings are configured differently.
+
+ * templdir to designate an alternate location for Privoxy's locally
+ customized CGI templates so that these are not overwritten during
+ upgrades.
+
+ * A new command line option --pre-chroot-nslookup hostname to initialize
+ the resolver library before chroot'ing. On some systems this reduces
+ the number of files that must be copied into the chroot tree. (Patch
+ provided by Stephen Gildea)
+
+ * The forward-override action allows changing of the forwarding settings
+ through the actions files. Combined with tags, this allows to choose
+ the forwarder based on client headers like the User-Agent, or the
+ request origin.
+
+ * The redirect action can now use regular expression substitutions
+ against the original URL.
+
+ * zlib support is now available as a compile time option to filter
+ compressed content. Patch provided by Wil Mahan.
+
+ * Improve various filters, and add new ones.
+
+ * Include support for RFC 3253 so that Subversion works with Privoxy.
+ Patch provided by Petr Kadlec.
+
+ * Logging can be completely turned off by not specifying a logfile
+ directive.
+
+ * A number of improvements to Privoxy's internal CGI pages, including
+ the use of favicons for error and control pages.
+
+ * Many bugfixes, memory leaks addressed, code improvements, and logging
+ improvements.
+
+ For a more detailed list of changes please have a look at the ChangeLog.
+
+ --------------------------------------------------------------------------
+
+ 3.1. Note to Upgraders
+
+ A quick list of things to be aware of before upgrading from earlier
+ versions of Privoxy:
+
+ * The recommended way to upgrade Privoxy is to backup your old
+ configuration files, install the new ones, verify that Privoxy is
+ working correctly and finally merge back your changes using diff and
+ maybe patch.
+
+ There are a number of new features in each Privoxy release and most of
+ them have to be explicitly enabled in the configuration files. Old
+ configuration files obviously don't do that and due to syntax changes
+ using old configuration files with a new Privoxy isn't always possible
+ anyway.
+
+ * Note that some installers remove earlier versions completely,
+ including configuration files, therefore you should really save any
+ important configuration files!
+
+ * On the other hand, other installers don't overwrite existing
+ configuration files, thinking you will want to do that yourself.
+
+ * standard.action now only includes the enabled actions. Not all actions
+ as before.
+
+ * In the default configuration only fatal errors are logged now. You can
+ change that in the debug section of the configuration file. You may
+ also want to enable more verbose logging until you verified that the
+ new Privoxy version is working as expected.
+
+ * Three other config file settings are now off by default:
+ enable-remote-toggle, enable-remote-http-toggle, and
+ enable-edit-actions. If you use or want these, you will need to
+ explicitly enable them, and be aware of the security issues involved.
+
+ * The "filter-client-headers" and "filter-server-headers" actions that
+ were introduced with Privoxy 3.0.5 to apply content filters to the
+ headers have been removed and replaced with new actions. See the
+ What's New section above.
+
+ --------------------------------------------------------------------------
+
+4. Quickstart to Using Privoxy
+
+ * Install Privoxy. See the Installation Section below for platform
+ specific information.
+
+ * Advanced users and those who want to offer Privoxy service to more
+ than just their local machine should check the main config file,
+ especially the security-relevant options. These are off by default.
+
+ * Start Privoxy, if the installation program has not done this already
+ (may vary according to platform). See the section Starting Privoxy.
+
+ * Set your browser to use Privoxy as HTTP and HTTPS (SSL) proxy by
+ setting the proxy configuration for address of 127.0.0.1 and port
+ 8118. DO NOT activate proxying for FTP or any protocols besides HTTP
+ and HTTPS (SSL) unless you intend to prevent your browser from using
+ these protocols.
+
+ * Flush your browser's disk and memory caches, to remove any cached ad
+ images. If using Privoxy to manage cookies, you should remove any
+ currently stored cookies too.
+
+ * A default installation should provide a reasonable starting point for
+ most. There will undoubtedly be occasions where you will want to
+ adjust the configuration, but that can be dealt with as the need
+ arises. Little to no initial configuration is required in most cases,
+ you may want to enable the web-based action editor though. Be sure to
+ read the warnings first.
+
+ See the Configuration section for more configuration options, and how
+ to customize your installation. You might also want to look at the
+ next section for a quick introduction to how Privoxy blocks ads and
+ banners.
+
+ * If you experience ads that slip through, innocent images that are
+ blocked, or otherwise feel the need to fine-tune Privoxy's behavior,
+ take a look at the actions files. As a quick start, you might find the
+ richly commented examples helpful. You can also view and edit the
+ actions files through the web-based user interface. The Appendix
+ "Troubleshooting: Anatomy of an Action" has hints on how to understand
+ and debug actions that "misbehave".
+
+ * Please see the section Contacting the Developers on how to report
+ bugs, problems with websites or to get help.
+
+ * Now enjoy surfing with enhanced control, comfort and privacy!
+
+ --------------------------------------------------------------------------
+
+ 4.1. Quickstart to Ad Blocking
+
+ Ad blocking is but one of Privoxy's array of features. Many of these
+ features are for the technically minded advanced user. But, ad and banner
+ blocking is surely common ground for everybody.
+
+ This section will provide a quick summary of ad blocking so you can get up
+ to speed quickly without having to read the more extensive information
+ provided below, though this is highly recommended.
+
+ First a bit of a warning ... blocking ads is much like blocking SPAM: the
+ more aggressive you are about it, the more likely you are to block things
+ that were not intended. And the more likely that some things may not work
+ as intended. So there is a trade off here. If you want extreme ad free
+ browsing, be prepared to deal with more "problem" sites, and to spend more
+ time adjusting the configuration to solve these unintended consequences.
+ In short, there is not an easy way to eliminate all ads. Either take the
+ easy way and settle for most ads blocked with the default configuration,
+ or jump in and tweak it for your personal surfing habits and preferences.
+
+ Secondly, a brief explanation of Privoxy's "actions". "Actions" in this
+ context, are the directives we use to tell Privoxy to perform some task
+ relating to HTTP transactions (i.e. web browsing). We tell Privoxy to take
+ some "action". Each action has a unique name and function. While there are
+ many potential actions in Privoxy's arsenal, only a few are used for ad
+ blocking. Actions, and action configuration files, are explained in depth
+ below.
+
+ Actions are specified in Privoxy's configuration, followed by one or more
+ URLs to which the action should apply. URLs can actually be URL type
+ patterns that use wildcards so they can apply potentially to a range of
+ similar URLs. The actions, together with the URL patterns are called a
+ section.
+
+ When you connect to a website, the full URL will either match one or more
+ of the sections as defined in Privoxy's configuration, or not. If so, then
+ Privoxy will perform the respective actions. If not, then nothing special
+ happens. Furthermore, web pages may contain embedded, secondary URLs that
+ your web browser will use to load additional components of the page, as it
+ parses the original page's HTML content. An ad image for instance, is just
+ an URL embedded in the page somewhere. The image itself may be on the same
+ server, or a server somewhere else on the Internet. Complex web pages will
+ have many such embedded URLs. Privoxy can deal with each URL individually,
+ so, for instance, the main page text is not touched, but images from
+ such-and-such server are blocked.
+
+ The most important actions for basic ad blocking are: block,
+ handle-as-image, handle-as-empty-document,and set-image-blocker:
+
+ * block - this is perhaps the single most used action, and is
+ particularly important for ad blocking. This action stops any contact
+ between your browser and any URL patterns that match this action's
+ configuration. It can be used for blocking ads, but also anything that
+ is determined to be unwanted. By itself, it simply stops any
+ communication with the remote server and sends Privoxy's own built-in
+ BLOCKED page instead to let you now what has happened (with some
+ exceptions, see below).
+
+ * handle-as-image - tells Privoxy to treat this URL as an image.
+ Privoxy's default configuration already does this for all common image
+ types (e.g. GIF), but there are many situations where this is not so
+ easy to determine. So we'll force it in these cases. This is
+ particularly important for ad blocking, since only if we know that
+ it's an image of some kind, can we replace it with an image of our
+ choosing, instead of the Privoxy BLOCKED page (which would only result
+ in a "broken image" icon). There are some limitations to this though.
+ For instance, you can't just brute-force an image substitution for an
+ entire HTML page in most situations.
+
+ * handle-as-empty-document - sends an empty document instead of
+ Privoxy's normal BLOCKED HTML page. This is useful for file types that
+ are neither HTML nor images, such as blocking JavaScript files.
+
+ * set-image-blocker - tells Privoxy what to display in place of an ad
+ image that has hit a block rule. For this to come into play, the URL
+ must match a block action somewhere in the configuration, and, it must
+ also match an handle-as-image action.
+
+ The configuration options on what to display instead of the ad are:
+
+ pattern - a checkerboard pattern, so that an ad replacement is
+ obvious. This is the default.
+
+ blank - A very small empty GIF image is displayed. This is the
+ so-called "invisible" configuration option.
+
+ http://<URL> - A redirect to any image anywhere of the user's
+ choosing (advanced usage).
+
+ Advanced users will eventually want to explore Privoxy filters as well.
+ Filters are very different from blocks. A "block" blocks a site, page, or
+ unwanted contented. Filters are a way of filtering or modifying what is
+ actually on the page. An example filter usage: a text replacement of
+ "no-no" for "nasty-word". That is a very simple example. This process can
+ be used for ad blocking, but it is more in the realm of advanced usage and
+ has some pitfalls to be wary off.
+
+ The quickest way to adjust any of these settings is with your browser
+ through the special Privoxy editor at
+ http://config.privoxy.org/show-status (shortcut: http://p.p/show-status).
+ This is an internal page, and does not require Internet access.
+
+ Note that as of Privoxy 3.0.7 beta the action editor is disabled by
+ default. Check the enable-edit-actions section in the configuration file
+ to learn why and in which cases it's safe to enable again.
+
+ If you decided to enable the action editor, select the appropriate
+ "actions" file, and click "Edit". It is best to put personal or local
+ preferences in user.action since this is not meant to be overwritten
+ during upgrades, and will over-ride the settings in other files. Here you
+ can insert new "actions", and URLs for ad blocking or other purposes, and
+ make other adjustments to the configuration. Privoxy will detect these
+ changes automatically.
+
+ A quick and simple step by step example:
+
+ * Right click on the ad image to be blocked, then select "Copy Link
+ Location" from the pop-up menu.
+
+ * Set your browser to http://config.privoxy.org/show-status
+
+ * Find user.action in the top section, and click on "Edit":
+
+ Figure 1. Actions Files in Use
+
+ * You should have a section with only block listed under "Actions:". If
+ not, click a "Insert new section below" button, and in the new section
+ that just appeared, click the Edit button right under the word
+ "Actions:". This will bring up a list of all actions. Find block near
+ the top, and click in the "Enabled" column, then "Submit" just below
+ the list.
+
+ * Now, in the block actions section, click the "Add" button, and paste
+ the URL the browser got from "Copy Link Location". Remove the http://
+ at the beginning of the URL. Then, click "Submit" (or "OK" if in a
+ pop-up window).
+
+ * Now go back to the original page, and press SHIFT-Reload (or flush all
+ browser caches). The image should be gone now.
+
+ This is a very crude and simple example. There might be good reasons to
+ use a wildcard pattern match to include potentially similar images from
+ the same site. For a more extensive explanation of "patterns", and the
+ entire actions concept, see the Actions section.
+
+ For advanced users who want to hand edit their config files, you might
+ want to now go to the Actions Files Tutorial. The ideas explained therein
+ also apply to the web-based editor.
+
+ There are also various filters that can be used for ad blocking (filters
+ are a special subset of actions). These fall into the "advanced" usage
+ category, and are explained in depth in later sections.
+
+ --------------------------------------------------------------------------
+
+5. Starting Privoxy
+
+ Before launching Privoxy for the first time, you will want to configure
+ your browser(s) to use Privoxy as a HTTP and HTTPS (SSL) proxy. The
+ default is 127.0.0.1 (or localhost) for the proxy address, and port 8118
+ (earlier versions used port 8000). This is the one configuration step that
+ must be done!
+
+ Please note that Privoxy can only proxy HTTP and HTTPS traffic. It will
+ not work with FTP or other protocols.
+
+ Figure 2. Proxy Configuration Showing Mozilla/Netscape HTTP and HTTPS
+ (SSL) Settings
+
+ With Firefox, this is typically set under:
+
+ Tools -> Options -> Advanced -> Network ->Connection -> Settings
+
+
+ Or optionally on some platforms:
+
+ Edit -> Preferences -> General -> Connection Settings -> Manual Proxy
+ Configuration
+
+
+ With Netscape (and Mozilla), this can be set under:
+
+ Edit -> Preferences -> Advanced -> Proxies -> HTTP Proxy
+
+
+ For Internet Explorer v.5-7:
+
+ Tools -> Internet Options -> Connections -> LAN Settings
+
+ Then, check "Use Proxy" and fill in the appropriate info (Address:
+ 127.0.0.1, Port: 8118). Include HTTPS (SSL), if you want HTTPS proxy
+ support too (sometimes labeled "Secure"). Make sure any checkboxes like
+ "Use the same proxy server for all protocols" is UNCHECKED. You want only
+ HTTP and HTTPS (SSL)!
+
+ Figure 3. Proxy Configuration Showing Internet Explorer HTTP and HTTPS
+ (Secure) Settings
+
+ After doing this, flush your browser's disk and memory caches to force a
+ re-reading of all pages and to get rid of any ads that may be cached.
+ Remove any cookies, if you want Privoxy to manage that. You are now ready
+ to start enjoying the benefits of using Privoxy!
+
+ Privoxy itself is typically started by specifying the main configuration
+ file to be used on the command line. If no configuration file is specified
+ on the command line, Privoxy will look for a file named config in the
+ current directory. Except on Win32 where it will try config.txt.
+
+ --------------------------------------------------------------------------
+
+ 5.1. Red Hat and Fedora
+
+ A default Red Hat installation may not start Privoxy upon boot. It will
+ use the file /etc/privoxy/config as its main configuration file.
+
+ # /etc/rc.d/init.d/privoxy start
+
+ Or ...
+
+ # service privoxy start
+
+ --------------------------------------------------------------------------
+
+ 5.2. Debian
+
+ We use a script. Note that Debian typically starts Privoxy upon booting
+ per default. It will use the file /etc/privoxy/config as its main
+ configuration file.
+
+ # /etc/init.d/privoxy start
+
+ --------------------------------------------------------------------------
+
+ 5.3. Windows
+
+ Click on the Privoxy Icon to start Privoxy. If no configuration file is
+ specified on the command line, Privoxy will look for a file named
+ config.txt. Note that Windows will automatically start Privoxy when the
+ system starts if you chose that option when installing.
+
+ Privoxy can run with full Windows service functionality. On Windows only,
+ the Privoxy program has two new command line arguments to install and
+ uninstall Privoxy as a service. See the Windows Installation instructions
+ for details.
+
+ --------------------------------------------------------------------------
+
+ 5.4. Solaris, NetBSD, FreeBSD, HP-UX and others
+
+ Example Unix startup command:
+
+ # /usr/sbin/privoxy /etc/privoxy/config
+
+ --------------------------------------------------------------------------
+
+ 5.5. OS/2
+
+ During installation, Privoxy is configured to start automatically when the
+ system restarts. You can start it manually by double-clicking on the
+ Privoxy icon in the Privoxy folder.
+
+ --------------------------------------------------------------------------
+
+ 5.6. Mac OSX
+
+ During installation, Privoxy is configured to start automatically when the
+ system restarts. To start Privoxy manually, double-click on the
+ StartPrivoxy.command icon in the /Library/Privoxy folder. Or, type this
+ command in the Terminal:
+
+ /Library/Privoxy/StartPrivoxy.command
+
+
+ You will be prompted for the administrator password.
+
+ --------------------------------------------------------------------------
+
+ 5.7. AmigaOS
+
+ Start Privoxy (with RUN <>NIL:) in your startnet script (AmiTCP), in
+ s:user-startup (RoadShow), as startup program in your startup script
+ (Genesis), or as startup action (Miami and MiamiDx). Privoxy will
+ automatically quit when you quit your TCP/IP stack (just ignore the
+ harmless warning your TCP/IP stack may display that Privoxy is still
+ running).
+
+ --------------------------------------------------------------------------
+
+ 5.8. Gentoo
+
+ A script is again used. It will use the file /etc/privoxy/config as its
+ main configuration file.
+
+ /etc/init.d/privoxy start
+
+
+ Note that Privoxy is not automatically started at boot time by default.
+ You can change this with the rc-update command.
+
+ rc-update add privoxy default
+
+
+ --------------------------------------------------------------------------
+
+ 5.9. Command Line Options
+
+ Privoxy may be invoked with the following command-line options:
+
+ * --version
+
+ Print version info and exit. Unix only.
+
+ * --help
+
+ Print short usage info and exit. Unix only.
+
+ * --no-daemon
+
+ Don't become a daemon, i.e. don't fork and become process group
+ leader, and don't detach from controlling tty. Unix only.
+
+ * --pidfile FILE
+
+ On startup, write the process ID to FILE. Delete the FILE on exit.
+ Failure to create or delete the FILE is non-fatal. If no FILE option
+ is given, no PID file will be used. Unix only.
+
+ * --user USER[.GROUP]
+
+ After (optionally) writing the PID file, assume the user ID of USER,
+ and if included the GID of GROUP. Exit if the privileges are not
+ sufficient to do so. Unix only.
+
+ * --chroot
+
+ Before changing to the user ID given in the --user option, chroot to
+ that user's home directory, i.e. make the kernel pretend to the
+ Privoxy process that the directory tree starts there. If set up
+ carefully, this can limit the impact of possible vulnerabilities in
+ Privoxy to the files contained in that hierarchy. Unix only.
+
+ * --pre-chroot-nslookup hostname
+
+ Specifies a hostname to look up before doing a chroot. On some
+ systems, initializing the resolver library involves reading config
+ files from /etc and/or loading additional shared libraries from /lib.
+ On these systems, doing a hostname lookup before the chroot reduces
+ the number of files that must be copied into the chroot tree.
+
+ For fastest startup speed, a good value is a hostname that is not in
+ /etc/hosts but that your local name server (listed in
+ /etc/resolv.conf) can resolve without recursion (that is, without
+ having to ask any other name servers). The hostname need not exist,
+ but if it doesn't, an error message (which can be ignored) will be
+ output.
+
+ * configfile
+
+ If no configfile is included on the command line, Privoxy will look
+ for a file named "config" in the current directory (except on Win32
+ where it will look for "config.txt" instead). Specify full path to
+ avoid confusion. If no config file is found, Privoxy will fail to
+ start.
+
+ On MS Windows only there are two additional command-line options to allow
+ Privoxy to install and run as a service. See the Window Installation
+ section for details.
+
+ --------------------------------------------------------------------------
+
+6. Privoxy Configuration
+
+ All Privoxy configuration is stored in text files. These files can be
+ edited with a text editor. Many important aspects of Privoxy can also be
+ controlled easily with a web browser.
+
+ --------------------------------------------------------------------------
+
+ 6.1. Controlling Privoxy with Your Web Browser
+
+ Privoxy's user interface can be reached through the special URL
+ http://config.privoxy.org/ (shortcut: http://p.p/), which is a built-in
+ page and works without Internet access. You will see the following
+ section:
+
+
+
+ Privoxy Menu
+
+ sB View & change the current configuration
+
+ sB View the source code version numbers
+
+ sB View the request headers.
+
+ sB Look up which actions apply to a URL and why
+
+ sB Toggle Privoxy on or off
+
+ sB Documentation
+
+
+ This should be self-explanatory. Note the first item leads to an editor
+ for the actions files, which is where the ad, banner, cookie, and URL
+ blocking magic is configured as well as other advanced features of
+ Privoxy. This is an easy way to adjust various aspects of Privoxy
+ configuration. The actions file, and other configuration files, are
+ explained in detail below.
+
+ "Toggle Privoxy On or Off" is handy for sites that might have problems
+ with your current actions and filters. You can in fact use it as a test to
+ see whether it is Privoxy causing the problem or not. Privoxy continues to
+ run as a proxy in this case, but all manipulation is disabled, i.e.
+ Privoxy acts like a normal forwarding proxy. There is even a toggle
+ Bookmarklet offered, so that you can toggle Privoxy with one click from
+ your browser.
+
+ Note that several of the features described above are disabled by default
+ in Privoxy 3.0.7 beta and later. Check the configuration file to learn why
+ and in which cases it's safe to enable them again.
+
+ --------------------------------------------------------------------------
+
+ 6.2. Configuration Files Overview
+
+ For Unix, *BSD and Linux, all configuration files are located in
+ /etc/privoxy/ by default. For MS Windows, OS/2, and AmigaOS these are all
+ in the same directory as the Privoxy executable.
+
+ The installed defaults provide a reasonable starting point, though some
+ settings may be aggressive by some standards. For the time being, the
+ principle configuration files are:
+
+ * The main configuration file is named config on Linux, Unix, BSD, OS/2,
+ and AmigaOS and config.txt on Windows. This is a required file.
+
+ * default.action (the main actions file) is used to define which
+ "actions" relating to banner-blocking, images, pop-ups, content
+ modification, cookie handling etc should be applied by default. It
+ also defines many exceptions (both positive and negative) from this
+ default set of actions that enable Privoxy to selectively eliminate
+ the junk, and only the junk, on as many websites as possible.
+
+ Multiple actions files may be defined in config. These are processed
+ in the order they are defined. Local customizations and locally
+ preferred exceptions to the default policies as defined in
+ default.action (which you will most probably want to define sooner or
+ later) are probably best applied in user.action, where you can
+ preserve them across upgrades. standard.action is only for Privoxy's
+ internal use.
+
+ There is also a web based editor that can be accessed from
+ http://config.privoxy.org/show-status (Shortcut:
+ http://p.p/show-status) for the various actions files.
+
+ * "Filter files" (the filter file) can be used to re-write the raw page
+ content, including viewable text as well as embedded HTML and
+ JavaScript, and whatever else lurks on any given web page. The
+ filtering jobs are only pre-defined here; whether to apply them or not
+ is up to the actions files. default.filter includes various filters
+ made available for use by the developers. Some are much more intrusive
+ than others, and all should be used with caution. You may define
+ additional filter files in config as you can with actions files. We
+ suggest user.filter for any locally defined filters or customizations.
+
+ The syntax of the configuration and filter files may change between
+ different Privoxy versions, unfortunately some enhancements cost backwards
+ compatibility.
+
+ All files use the "#" character to denote a comment (the rest of the line
+ will be ignored) and understand line continuation through placing a
+ backslash ("\") as the very last character in a line. If the # is preceded
+ by a backslash, it looses its special function. Placing a # in front of an
+ otherwise valid configuration line to prevent it from being interpreted is
+ called "commenting out" that line. Blank lines are ignored.
+
+ The actions files and filter files can use Perl style regular expressions
+ for maximum flexibility.
+
+ After making any changes, there is no need to restart Privoxy in order for
+ the changes to take effect. Privoxy detects such changes automatically.
+ Note, however, that it may take one or two additional requests for the
+ change to take effect. When changing the listening address of Privoxy,
+ these "wake up" requests must obviously be sent to the old listening
+ address.
+
+ --------------------------------------------------------------------------
+
+7. The Main Configuration File
+
+ Again, the main configuration file is named config on Linux/Unix/BSD and
+ OS/2, and config.txt on Windows. Configuration lines consist of an initial
+ keyword followed by a list of values, all separated by whitespace (any
+ number of spaces or tabs). For example:
+
+ confdir /etc/privoxy
+
+ Assigns the value /etc/privoxy to the option confdir and thus indicates
+ that the configuration directory is named "/etc/privoxy/".
+
+ All options in the config file except for confdir and logdir are optional.
+ Watch out in the below description for what happens if you leave them
+ unset.
+
+ The main config file controls all aspects of Privoxy's operation that are
+ not location dependent (i.e. they apply universally, no matter where you
+ may be surfing).
+
+ --------------------------------------------------------------------------
+
+ 7.1. Local Set-up Documentation
+
+ If you intend to operate Privoxy for more users than just yourself, it
+ might be a good idea to let them know how to reach you, what you block and
+ why you do that, your policies, etc.
+
+ --------------------------------------------------------------------------
+
+ 7.1.1. user-manual
+
+ Specifies:
+
+ Location of the Privoxy User Manual.
+
+ Type of value:
+
+ A fully qualified URI
+
+ Default value:
+
+ Unset
+
+ Effect if unset:
+
+ http://www.privoxy.org/version/user-manual/ will be used, where
+ version is the Privoxy version.
+
+ Notes:
+
+ The User Manual URI is the single best source of information on
+ Privoxy, and is used for help links from some of the internal CGI
+ pages. The manual itself is normally packaged with the binary
+ distributions, so you probably want to set this to a locally
+ installed copy.
+
+ Examples:
+
+ The best all purpose solution is simply to put the full local PATH
+ to where the User Manual is located:
+
+ user-manual /usr/share/doc/privoxy/user-manual
+
+ The User Manual is then available to anyone with access to
+ Privoxy, by following the built-in URL:
+ http://config.privoxy.org/user-manual/ (or the shortcut:
+ http://p.p/user-manual/).
+
+ If the documentation is not on the local system, it can be
+ accessed from a remote server, as:
+
+ user-manual http://example.com/privoxy/user-manual/
+
+ +---------------------------------------------------------+
+ | Warning |
+ |---------------------------------------------------------|
+ | If set, this option should be the first option in the |
+ | config file, because it is used while the config file |
+ | is being read on start-up. |
+ +---------------------------------------------------------+
+
+ --------------------------------------------------------------------------
+
+ 7.1.2. trust-info-url
+
+ Specifies:
+
+ A URL to be displayed in the error page that users will see if
+ access to an untrusted page is denied.
+
+ Type of value:
+
+ URL
+
+ Default value:
+
+ Two example URLs are provided
+
+ Effect if unset:
+
+ No links are displayed on the "untrusted" error page.
+
+ Notes:
+
+ The value of this option only matters if the experimental trust
+ mechanism has been activated. (See trustfile below.)
+
+ If you use the trust mechanism, it is a good idea to write up some
+ on-line documentation about your trust policy and to specify the
+ URL(s) here. Use multiple times for multiple URLs.
+
+ The URL(s) should be added to the trustfile as well, so users
+ don't end up locked out from the information on why they were
+ locked out in the first place!
+
+ --------------------------------------------------------------------------
+
+ 7.1.3. admin-address
+
+ Specifies:
+
+ An email address to reach the Privoxy administrator.
+
+ Type of value:
+
+ Email address
+
+ Default value:
+
+ Unset
+
+ Effect if unset:
+
+ No email address is displayed on error pages and the CGI user
+ interface.
+
+ Notes:
+
+ If both admin-address and proxy-info-url are unset, the whole
+ "Local Privoxy Support" box on all generated pages will not be
+ shown.
+
+ --------------------------------------------------------------------------
+
+ 7.1.4. proxy-info-url
+
+ Specifies:
+
+ A URL to documentation about the local Privoxy setup,
+ configuration or policies.
+
+ Type of value:
+
+ URL
+
+ Default value:
+
+ Unset
+
+ Effect if unset:
+
+ No link to local documentation is displayed on error pages and the
+ CGI user interface.
+
+ Notes:
+
+ If both admin-address and proxy-info-url are unset, the whole
+ "Local Privoxy Support" box on all generated pages will not be
+ shown.
+
+ This URL shouldn't be blocked ;-)
+
+ --------------------------------------------------------------------------
+
+ 7.2. Configuration and Log File Locations
+
+ Privoxy can (and normally does) use a number of other files for additional
+ configuration, help and logging. This section of the configuration file
+ tells Privoxy where to find those other files.
+
+ The user running Privoxy, must have read permission for all configuration
+ files, and write permission to any files that would be modified, such as
+ log files and actions files.
+
+ --------------------------------------------------------------------------
+
+ 7.2.1. confdir
+
+ Specifies:
+
+ The directory where the other configuration files are located.
+
+ Type of value:
+
+ Path name
+
+ Default value:
+
+ /etc/privoxy (Unix) or Privoxy installation dir (Windows)
+
+ Effect if unset:
+
+ Mandatory
+
+ Notes:
+
+ No trailing "/", please.
+
+ --------------------------------------------------------------------------
+
+ 7.2.2. templdir
+
+ Specifies:
+
+ An alternative directory where the templates are loaded from.
+
+ Type of value:
+
+ Path name
+
+ Default value:
+
+ unset
+
+ Effect if unset:
+
+ The templates are assumed to be located in confdir/template.
+
+ Notes:
+
+ Privoxy's original templates are usually overwritten with each
+ update. Use this option to relocate customized templates that
+ should be kept. As template variables might change between
+ updates, you shouldn't expect templates to work with Privoxy
+ releases other than the one they were part of, though.
+
+ --------------------------------------------------------------------------
+
+ 7.2.3. logdir
+
+ Specifies:
+
+ The directory where all logging takes place (i.e. where logfile
+ and jarfile are located).
+
+ Type of value:
+
+ Path name
+
+ Default value:
+
+ /var/log/privoxy (Unix) or Privoxy installation dir (Windows)
+
+ Effect if unset:
+
+ Mandatory
+
+ Notes:
+
+ No trailing "/", please.
+
+ --------------------------------------------------------------------------
+
+ 7.2.4. actionsfile
+
+ Specifies:
+
+ The actions file(s) to use
+
+ Type of value:
+
+ Complete file name, relative to confdir
+
+ Default values:
+
+ standard.action # Internal purposes, no editing recommended
+ default.action # Main actions file
+ user.action # User customizations
+
+ Effect if unset:
+
+ No actions are taken at all. More or less neutral proxying.
+
+ Notes:
+
+ Multiple actionsfile lines are permitted, and are in fact
+ recommended!
+
+ The default values include standard.action, which is used for
+ internal purposes and should be loaded, default.action, which is
+ the "main" actions file maintained by the developers, and
+ user.action, where you can make your personal additions.
+
+ Actions files contain all the per site and per URL configuration
+ for ad blocking, cookie management, privacy considerations, etc.
+ There is no point in using Privoxy without at least one actions
+ file.
+
+ Note that since Privoxy 3.0.7, the complete filename, including
+ the ".action" extension has to be specified. The syntax change was
+ necessary to be consistent with the other file options and to
+ allow previously forbidden characters.
+
+ --------------------------------------------------------------------------
+
+ 7.2.5. filterfile
+
+ Specifies:
+
+ The filter file(s) to use
+
+ Type of value:
+
+ File name, relative to confdir
+
+ Default value:
+
+ default.filter (Unix) or default.filter.txt (Windows)
+
+ Effect if unset:
+
+ No textual content filtering takes place, i.e. all +filter{name}
+ actions in the actions files are turned neutral.
+
+ Notes:
+
+ Multiple filterfile lines are permitted.
+
+ The filter files contain content modification rules that use
+ regular expressions. These rules permit powerful changes on the
+ content of Web pages, and optionally the headers as well, e.g.,
+ you could try to disable your favorite JavaScript annoyances,
+ re-write the actual displayed text, or just have some fun playing
+ buzzword bingo with web pages.
+
+ The +filter{name} actions rely on the relevant filter (name) to be
+ defined in a filter file!
+
+ A pre-defined filter file called default.filter that contains a
+ number of useful filters for common problems is included in the
+ distribution. See the section on the filter action for a list.
+
+ It is recommended to place any locally adapted filters into a
+ separate file, such as user.filter.
+
+ --------------------------------------------------------------------------
+
+ 7.2.6. logfile
+
+ Specifies:
+
+ The log file to use
+
+ Type of value:
+
+ File name, relative to logdir
+
+ Default value:
+
+ Unset (commented out). When activated: logfile (Unix) or
+ privoxy.log (Windows).
+
+ Effect if unset:
+
+ No logfile is written.
+
+ Notes:
+
+ The logfile is where all logging and error messages are written.
+ The level of detail and number of messages are set with the debug
+ option (see below). The logfile can be useful for tracking down a
+ problem with Privoxy (e.g., it's not blocking an ad you think it
+ should block) and it can help you to monitor what your browser is
+ doing.
+
+ Depending on the debug options below, the logfile may be a privacy
+ risk if third parties can get access to it. As most users will
+ never look at it, Privoxy 3.0.7 and later only log fatal errors by
+ default.
+
+ For most troubleshooting purposes, you will have to change that,
+ please refer to the debugging section for details.
+
+ Your logfile will grow indefinitely, and you will probably want to
+ periodically remove it. On Unix systems, you can do this with a
+ cron job (see "man cron"). For Red Hat based Linux distributions,
+ a logrotate script has been included.
+
+ Any log files must be writable by whatever user Privoxy is being
+ run as (on Unix, default user id is "privoxy").
+
+ --------------------------------------------------------------------------
+
+ 7.2.7. jarfile
+
+ Specifies:
+
+ The file to store intercepted cookies in
+
+ Type of value:
+
+ File name, relative to logdir
+
+ Default value:
+
+ Unset (commented out). When activated: jarfile (Unix) or
+ privoxy.jar (Windows).
+
+ Effect if unset:
+
+ Intercepted cookies are not stored in a dedicated log file.
+
+ Notes:
+
+ The jarfile may grow to ridiculous sizes over time.
+
+ If debug 8 (show header parsing) is enabled, cookies are also
+ written to the logfile with the rest of the headers. Therefore
+ this option isn't very useful and may be removed in future
+ releases. Please report to the developers if you are still using
+ it.
+
+ --------------------------------------------------------------------------
+
+ 7.2.8. trustfile
+
+ Specifies:
+
+ The name of the trust file to use
+
+ Type of value:
+
+ File name, relative to confdir
+
+ Default value:
+
+ Unset (commented out). When activated: trust (Unix) or trust.txt
+ (Windows)
+
+ Effect if unset:
+
+ The entire trust mechanism is disabled.
+
+ Notes:
+
+ The trust mechanism is an experimental feature for building
+ white-lists and should be used with care. It is NOT recommended
+ for the casual user.
+
+ If you specify a trust file, Privoxy will only allow access to
+ sites that are specified in the trustfile. Sites can be listed in
+ one of two ways:
+
+ Prepending a ~ character limits access to this site only (and any
+ sub-paths within this site), e.g. ~www.example.com allows access
+ to ~www.example.com/features/news.html, etc.
+
+ Or, you can designate sites as trusted referrers, by prepending
+ the name with a + character. The effect is that access to
+ untrusted sites will be granted -- but only if a link from this
+ trusted referrer was used to get there. The link target will then
+ be added to the "trustfile" so that future, direct accesses will
+ be granted. Sites added via this mechanism do not become trusted
+ referrers themselves (i.e. they are added with a ~ designation).
+ There is a limit of 512 such entries, after which new entries will
+ not be made.
+
+ If you use the + operator in the trust file, it may grow
+ considerably over time.
+
+ It is recommended that Privoxy be compiled with the
+ --disable-force, --disable-toggle and --disable-editor options, if
+ this feature is to be used.
+
+ Possible applications include limiting Internet access for
+ children.
+
+ --------------------------------------------------------------------------
+
+ 7.3. Debugging
+
+ These options are mainly useful when tracing a problem. Note that you
+ might also want to invoke Privoxy with the --no-daemon command line option
+ when debugging.
+
+ --------------------------------------------------------------------------
+
+ 7.3.1. debug
+
+ Specifies:
+
+ Key values that determine what information gets logged.
+
+ Type of value:
+
+ Integer values
+
+ Default value:
+
+ 0 (i.e.: only fatal errors (that cause Privoxy to exit) are
+ logged)
+
+ Effect if unset:
+
+ Default value is used (see above).
+
+ Notes:
+
+ The available debug levels are:
+
+ debug 1 # log each request destination (and the crunch reason if Privoxy intercepted the request)
+ debug 2 # show each connection status
+ debug 4 # show I/O status
+ debug 8 # show header parsing
+ debug 16 # log all data written to the network into the logfile
+ debug 32 # debug force feature
+ debug 64 # debug regular expression filters
+ debug 128 # debug redirects
+ debug 256 # debug GIF de-animation
+ debug 512 # Common Log Format
+ debug 1024 # debug kill pop-ups
+ debug 2048 # CGI user interface
+ debug 4096 # Startup banner and warnings.
+ debug 8192 # Non-fatal errors
+
+ To select multiple debug levels, you can either add them or use
+ multiple debug lines.
+
+ A debug level of 1 is informative because it will show you each
+ request as it happens. 1, 4096 and 8192 are recommended so that
+ you will notice when things go wrong. The other levels are
+ probably only of interest if you are hunting down a specific
+ problem. They can produce a hell of an output (especially 16).
+
+ Privoxy used to ship with the debug levels recommended above
+ enabled by default, but due to privacy concerns 3.0.7 and later
+ are configured to only log fatal errors.
+
+ If you are used to the more verbose settings, simply enable the
+ debug lines below again.
+
+ If you want to use pure CLF (Common Log Format), you should set
+ "debug 512" ONLY and not enable anything else.
+
+ Privoxy has a hard-coded limit for the length of log messages. If
+ it's reached, messages are logged truncated and marked with "...
+ [too long, truncated]".
+
+ Please don't file any support requests without trying to reproduce
+ the problem with increased debug level first. Once you read the
+ log messages, you may even be able to solve the problem on your
+ own.
+
+ --------------------------------------------------------------------------
+
+ 7.3.2. single-threaded
+
+ Specifies:
+
+ Whether to run only one server thread.
+
+ Type of value:
+
+ None
+
+ Default value:
+
+ Unset
+
+ Effect if unset:
+
+ Multi-threaded (or, where unavailable: forked) operation, i.e. the
+ ability to serve multiple requests simultaneously.
+
+ Notes:
+
+ This option is only there for debugging purposes. It will
+ drastically reduce performance.
+
+ --------------------------------------------------------------------------
+
+ 7.4. Access Control and Security
+
+ This section of the config file controls the security-relevant aspects of
+ Privoxy's configuration.
+
+ --------------------------------------------------------------------------
+
+ 7.4.1. listen-address
+
+ Specifies:
+
+ The IP address and TCP port on which Privoxy will listen for
+ client requests.
+
+ Type of value:
+
+ [IP-Address]:Port
+
+ Default value:
+
+ 127.0.0.1:8118
+
+ Effect if unset:
+
+ Bind to 127.0.0.1 (localhost), port 8118. This is suitable and
+ recommended for home users who run Privoxy on the same machine as
+ their browser.
+
+ Notes:
+
+ You will need to configure your browser(s) to this proxy address
+ and port.
+
+ If you already have another service running on port 8118, or if
+ you want to serve requests from other machines (e.g. on your local
+ network) as well, you will need to override the default.
+
+ If you leave out the IP address, Privoxy will bind to all
+ interfaces (addresses) on your machine and may become reachable
+ from the Internet. In that case, consider using access control
+ lists (ACL's, see below), and/or a firewall.
+
+ If you open Privoxy to untrusted users, you will also want to make
+ sure that the following actions are disabled: enable-edit-actions
+ and enable-remote-toggle
+
+ Example:
+
+ Suppose you are running Privoxy on a machine which has the address
+ 192.168.0.1 on your local private network (192.168.0.0) and has
+ another outside connection with a different address. You want it
+ to serve requests from inside only:
+
+ listen-address 192.168.0.1:8118
+
+ --------------------------------------------------------------------------
+
+ 7.4.2. toggle
+
+ Specifies:
+
+ Initial state of "toggle" status
+
+ Type of value:
+
+ 1 or 0
+
+ Default value:
+
+ 1
+
+ Effect if unset:
+
+ Act as if toggled on
+
+ Notes:
+
+ If set to 0, Privoxy will start in "toggled off" mode, i.e. mostly
+ behave like a normal, content-neutral proxy with both ad blocking
+ and content filtering disabled. See enable-remote-toggle below.
+
+ 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:
+
+ 0
+
+ Effect if unset:
+
+ The web-based toggle feature is disabled.
+
+ Notes:
+
+ When toggled off, Privoxy mostly acts like a normal,
+ content-neutral proxy, i.e. doesn't block ads or filter content.
+
+ 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 malicious client side code (e.g Java) is also capable of
+ using this option.
+
+ As a lot of Privoxy users don't read documentation, this feature
+ is disabled by default.
+
+ Note that you must have compiled Privoxy with support for this
+ feature, otherwise this option has no effect.
+
+ --------------------------------------------------------------------------
+
+ 7.4.4. enable-remote-http-toggle
+
+ Specifies:
+
+ Whether or not Privoxy recognizes special HTTP headers to change
+ its behaviour.
+
+ Type of value:
+
+ 0 or 1
+
+ Default value:
+
+ 0
+
+ Effect if unset:
+
+ Privoxy ignores special HTTP headers.
+
+ Notes:
+
+ When toggled on, the client can change Privoxy's behaviour by
+ setting special HTTP headers. Currently the only supported special
+ header is "X-Filter: No", to disable filtering for the ongoing
+ request, even if it is enabled in one of the action files.
+
+ This feature is disabled by default. If you are using Privoxy in a
+ environment with trusted clients, you may enable this feature at
+ your discretion. Note that malicious client side code (e.g Java)
+ is also capable of using this feature.
+
+ This option will be removed in future releases as it has been
+ obsoleted by the more general header taggers.
+
+ --------------------------------------------------------------------------
+
+ 7.4.5. enable-edit-actions
+
+ Specifies:
+
+ Whether or not the web-based actions file editor may be used
+
+ Type of value:
+
+ 0 or 1
+
+ Default value:
+
+ 0
+
+ Effect if unset:
+
+ The web-based actions file editor is disabled.
+
+ Notes:
+
+ 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.
+
+ This option is not recommended for environments with untrusted
+ users and as a lot of Privoxy users don't read documentation, this
+ feature is disabled by default.
+
+ Note that malicious client side code (e.g Java) is also capable of
+ using the actions editor and you shouldn't enable this options
+ unless you understand the consequences and are sure your browser
+ is configured correctly.
+
+ Note that you must have compiled Privoxy with support for this
+ feature, otherwise this option has no effect.
+
+ --------------------------------------------------------------------------
+
+ 7.4.6. enforce-blocks
+
+ Specifies:
+
+ Whether the user is allowed to ignore blocks and can "go there
+ anyway".
+
+ Type of value:
+
+ 0 or 1
+
+ Default value:
+
+ 0
+
+ Effect if unset:
+
+ Blocks are not enforced.
+
+ Notes:
+
+ Privoxy is mainly used to block and filter requests as a service
+ to the user, for example to block ads and other junk that clogs
+ the pipes. Privoxy's configuration isn't perfect and sometimes
+ innocent pages are blocked. In this situation it makes sense to
+ allow the user to enforce the request and have Privoxy ignore the
+ block.
+
+ In the default configuration Privoxy's "Blocked" page contains a
+ "go there anyway" link to adds a special string (the force prefix)
+ to the request URL. If that link is used, Privoxy will detect the
+ force prefix, remove it again and let the request pass.
+
+ Of course Privoxy can also be used to enforce a network policy. In
+ that case the user obviously should not be able to bypass any
+ blocks, and that's what the "enforce-blocks" option is for. If
+ it's enabled, Privoxy hides the "go there anyway" link. If the
+ user adds the force prefix by hand, it will not be accepted and
+ the circumvention attempt is logged.
+
+ Examples:
+
+ enforce-blocks 1
+
+ --------------------------------------------------------------------------
+
+ 7.4.7. 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 Privoxy 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, Privoxy only
+ talks 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 (most sites are).
+
+ 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 (or other domains hosted on
+ the same system):
+
+ 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 the
+ IP address behind www.dirty-stuff.example.com:
+
+ permit-access 192.168.45.64/26
+ deny-access 192.168.45.73 www.dirty-stuff.example.com
+
+ --------------------------------------------------------------------------
+
+ 7.4.8. 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.
+
+ Forwarding can be used to chain Privoxy with a caching proxy to speed up
+ browsing. Using a parent proxy may also be necessary if the machine that
+ Privoxy runs on has no direct Internet access.
+
+ Note that parent proxies can severely decrease your privacy level. For
+ example a parent proxy could add your IP address to the request headers
+ and if it's a caching proxy it may add the "Etag" header to revalidation
+ requests again, even though you configured Privoxy to remove it. It may
+ also ignore Privoxy's header time randomization and use the original
+ values which could be used by the server as cookie replacement to track
+ your steps between visits.
+
+ 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_pattern http_parent[:port]
+
+ where target_pattern is a URL pattern that specifies to which
+ requests (i.e. URLs) this forward rule shall apply. Use / to
+ denote "all URLs". http_parent[:port] is the DNS name or IP
+ address of the parent HTTP proxy through which the requests should
+ be forwarded, optionally followed by its listening port (default:
+ 8080). Use a single dot (.) to denote "no forwarding".
+
+ 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 parent proxy, except SSL on port 443
+ (which it doesn't handle):
+
+ forward / parent-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.isp.example.net:8000
+ forward .isp.example.net .
+
+ --------------------------------------------------------------------------
+
+ 7.5.2. forward-socks4 and forward-socks4a
+
+ Specifies:
+
+ Through which SOCKS proxy (and optionally to which parent HTTP
+ proxy) specific requests should be routed.
+
+ Type of value:
+
+ target_pattern socks_proxy[:port] http_parent[:port]
+
+ where target_pattern is a URL pattern that specifies to which
+ requests (i.e. URLs) this forward rule shall apply. Use / to
+ denote "all URLs". 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.isp.example.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 .
+
+ To chain Privoxy and Tor, both running on the same system, you
+ would use something like:
+
+ forward-socks4a / 127.0.0.1:9050 .
+
+ The public Tor network can't be used to reach your local network,
+ if you need to access local servers you therefore might want to
+ make some exceptions:
+
+ forward 192.168.*.*/ .
+ forward 10.*.*.*/ .
+ forward 127.*.*.*/ .
+
+ Unencrypted connections to systems in these address ranges will be
+ as (un)secure as the local network is, but the alternative is that
+ you can't reach the local network through Privoxy at all. Of
+ course this may actually be desired and there is no reason to make
+ these exceptions if you aren't sure you need them.
+
+ If you also want to be able to reach servers in your local network
+ by using their names, you will need additional exceptions that
+ look like this:
+
+ forward localhost/ .
+
+ --------------------------------------------------------------------------
+
+ 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.example.net. And host-b
+ has a PPP connection to isp-b.example.org. Both run Privoxy. Their
+ forwarding configuration can look like this:
+
+ host-a:
+
+ forward / .
+ forward .isp-b.example.net host-b:8118
+
+ host-b:
+
+ forward / .
+ forward .isp-a.example.org 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 chaining 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.
+
+ You could just as well decide to only forward requests you suspect of
+ leading to Windows executables through a virus-scanning parent proxy, say,
+ on antivir.example.com, port 8010:
+
+ forward / .
+ forward /.*\.(exe|com|dll|zip)$ antivir.example.com:8010
+
+ --------------------------------------------------------------------------
+
+ 7.5.4. forwarded-connect-retries
+
+ Specifies:
+
+ How often Privoxy retries if a forwarded connection request fails.
+
+ Type of value:
+
+ Number of retries.
+
+ Default value:
+
+ 0
+
+ Effect if unset:
+
+ Connections forwarded through other proxies are treated like
+ direct connections and no retry attempts are made.
+
+ Notes:
+
+ forwarded-connect-retries is mainly interesting for socks4a
+ connections, where Privoxy can't detect why the connections
+ failed. The connection might have failed because of a DNS timeout
+ in which case a retry makes sense, but it might also have failed
+ because the server doesn't exist or isn't reachable. In this case
+ the retry will just delay the appearance of Privoxy's error
+ message.
+
+ Note that in the context of this option, "forwarded connections"
+ includes all connections that Privoxy forwards through other
+ proxies. This option is not limited to the HTTP CONNECT method.
+
+ Only use this option, if you are getting lots of
+ forwarding-related error messages that go away when you try again
+ manually. Start with a small value and check Privoxy's logfile
+ from time to time, to see how many retries are usually needed.
+
+ Examples:
+
+ forwarded-connect-retries 1
+
+ --------------------------------------------------------------------------
+
+ 7.5.5. accept-intercepted-requests
+
+ Specifies:
+
+ Whether intercepted requests should be treated as valid.
+
+ Type of value:
+
+ 0 or 1
+
+ Default value:
+
+ 0
+
+ Effect if unset:
+
+ Only proxy requests are accepted, intercepted requests are treated
+ as invalid.
+
+ Notes:
+
+ If you don't trust your clients and want to force them to use
+ Privoxy, enable this option and configure your packet filter to
+ redirect outgoing HTTP connections into Privoxy.
+
+ Make sure that Privoxy's own requests aren't redirected as well.
+ Additionally take care that Privoxy can't intentionally connect to
+ itself, otherwise you could run into redirection loops if
+ Privoxy's listening port is reachable by the outside or an
+ attacker has access to the pages you visit.
+
+ Examples:
+
+ accept-intercepted-requests 1
+
+ --------------------------------------------------------------------------
+
+ 7.5.6. allow-cgi-request-crunching
+
+ Specifies:
+
+ Whether requests to Privoxy's CGI pages can be blocked or
+ redirected.
+
+ Type of value:
+
+ 0 or 1
+
+ Default value:
+
+ 0
+
+ Effect if unset:
+
+ Privoxy ignores block and redirect actions for its CGI pages.
+
+ Notes:
+
+ By default Privoxy ignores block or redirect actions for its CGI
+ pages. Intercepting these requests can be useful in multi-user
+ setups to implement fine-grained access control, but it can also
+ render the complete web interface useless and make debugging
+ problems painful if done without care.
+
+ Don't enable this option unless you're sure that you really need
+ it.
+
+ Examples:
+
+ allow-cgi-request-crunching 1
+
+ --------------------------------------------------------------------------
+
+ 7.5.7. split-large-forms
+
+ Specifies:
+
+ Whether the CGI interface should stay compatible with broken HTTP
+ clients.
+
+ Type of value:
+
+ 0 or 1
+
+ Default value:
+
+ 0
+
+ Effect if unset:
+
+ The CGI form generate long GET URLs.
+
+ Notes:
+
+ Privoxy's CGI forms can lead to rather long URLs. This isn't a
+ problem as far as the HTTP standard is concerned, but it can
+ confuse clients with arbitrary URL length limitations.
+
+ Enabling split-large-forms causes Privoxy to divide big forms into
+ smaller ones to keep the URL length down. It makes editing a lot
+ less convenient and you can no longer submit all changes at once,
+ but at least it works around this browser bug.
+
+ If you don't notice any editing problems, there is no reason to
+ enable this option, but if one of the submit buttons appears to be
+ broken, you should give it a try.
+
+ Examples:
+
+ split-large-forms 1
+
+ --------------------------------------------------------------------------
+
+ 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 determines how ad images, cookies and various other aspects
+ of HTTP content and transactions are handled, and on which sites (or even
+ parts thereof). There are a number of such actions, with a wide range of
+ functionality. Each action does something a little different. These
+ actions give us a veritable arsenal of tools with which to exert our
+ control, preferences and independence. Actions can be combined so that
+ their effects are aggregated when applied against a given set of URLs.
+
+ There are three action files included with Privoxy with differing
+ purposes:
+
+ * 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 as-is for most users. This is
+ the file that the developers are keeping updated, and making available
+ to users. The user's preferences as set in standard.action, e.g.
+ either Cautious (the default), Medium, or Advanced (see below).
+
+ * 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.
+
+ * standard.action - is used only by the web based editor at
+ http://config.privoxy.org/edit-actions-list?f=default, to set various
+ pre-defined sets of rules for the default actions section in
+ default.action.
+
+ Edit Set to Cautious Set to Medium Set to Advanced
+
+ These have increasing levels of aggressiveness and have no influence
+ on your browsing unless you select them explicitly in the editor. A
+ default installation should be pre-set to Cautious (versions prior to
+ 3.0.5 were set to Medium). New users should try this for a while
+ before adjusting the settings to more aggressive levels. The more
+ aggressive the settings, then the more likelihood there is of problems
+ such as sites not working as they should.
+
+ The Edit button allows you to turn each action on/off individually for
+ fine-tuning. The Cautious button changes the actions list to low/safe
+ settings which will activate ad blocking and a minimal set of
+ Privoxy's features, and subsequently there will be less of a chance
+ for accidental problems. The Medium button sets the list to a medium
+ level of other features and a low level set of privacy features. The
+ Advanced button sets the list to a high level of ad blocking and
+ medium level of privacy. See the chart below. The latter three buttons
+ over-ride any changes via with the Edit button. More fine-tuning can
+ be done in the lower sections of this internal page.
+
+ It is not recommend to edit the standard.action file itself.
+
+ The default profiles, and their associated actions, as pre-defined in
+ standard.action are:
+
+ Table 1. Default Configurations
+
+ +--------------------------------------------------------------------+
+ | Feature | Cautious | Medium | Advanced |
+ |-------------------------+-------------+--------------+-------------|
+ | Ad-blocking | medium | high | high |
+ | Aggressiveness | | | |
+ |-------------------------+-------------+--------------+-------------|
+ | Ad-filtering by size | no | yes | yes |
+ |-------------------------+-------------+--------------+-------------|
+ | Ad-filtering by link | no | no | yes |
+ |-------------------------+-------------+--------------+-------------|
+ | Pop-up killing | blocks only | blocks only | blocks only |
+ |-------------------------+-------------+--------------+-------------|
+ | Privacy Features | low | medium | medium/high |
+ |-------------------------+-------------+--------------+-------------|
+ | Cookie handling | none | session-only | kill |
+ |-------------------------+-------------+--------------+-------------|
+ | Referer forging | no | yes | yes |
+ |-------------------------+-------------+--------------+-------------|
+ | GIF de-animation | no | yes | yes |
+ |-------------------------+-------------+--------------+-------------|
+ | Fast redirects | no | no | yes |
+ |-------------------------+-------------+--------------+-------------|
+ | HTML taming | no | no | yes |
+ |-------------------------+-------------+--------------+-------------|
+ | JavaScript taming | no | no | yes |
+ |-------------------------+-------------+--------------+-------------|
+ | Web-bug killing | no | yes | yes |
+ |-------------------------+-------------+--------------+-------------|
+ | Image tag reordering | no | no | yes |
+ +--------------------------------------------------------------------+
+
+ The list of actions files to be used are defined in the main configuration
+ file, and are processed in the order they are defined (e.g. default.action
+ is typically processed before user.action). The content of these can all
+ be viewed and edited from http://config.privoxy.org/show-status. The
+ over-riding principle when applying actions, is that the last action that
+ matches a given URL wins. The broadest, most general rules go first
+ (defined in default.action), followed by any exceptions (typically also in
+ default.action), which are then followed lastly by any local preferences
+ (typically in user.action). Generally, user.action has the last word.
+
+ An actions file typically has multiple sections. If you want to use
+ "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 it 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 whose content you would rather not see. Cookies
+ can be accepted or rejected, or accepted only during the current browser
+ session (i.e. not written to disk), content can be modified, some
+ JavaScripts tamed, user-tracking fooled, and much more. See below for a
+ 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. And, things can always change, requiring refinements in
+ the configuration. 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 crunch all cookies per default, you'll have to make
+ exceptions from that rule for sites that you regularly use and that
+ require cookies for actually useful purposes, like maybe your bank,
+ favorite shop, or newspaper.
+
+ 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. Note: the config file option
+ enable-edit-actions must be enabled for this to work. The editor allows
+ both fine-grained control over every single feature on a per-URL basis,
+ and easy choosing from wholesale sets of defaults like "Cautious",
+ "Medium" or "Advanced". Warning: the "Advanced" setting is more
+ aggressive, and will be more likely to cause problems for some sites.
+ Experienced users only!
+
+ If you prefer plain text editing to GUIs, you can of course also directly
+ edit the the actions files with your favorite text editor. Look at
+ default.action which is richly commented with many good examples.
+
+ --------------------------------------------------------------------------
+
+ 8.3. How Actions are Applied to Requests
+
+ 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 and tag patterns, each on a separate line.
+
+ To determine which actions apply to a request, the URL of the request is
+ compared to all URL patterns in each "action file". Every time it matches,
+ the list of applicable actions for the request is incrementally updated,
+ using the heading of the section in which the pattern is located. The same
+ is done again for tags and tag patterns later on.
+
+ If multiple applying sections set the same action differently, the last
+ match wins. If not, the effects are aggregated. E.g. a URL might match a
+ regular section with a heading line of { +handle-as-image }, then later
+ another one with just { +block }, resulting in both actions to apply. And
+ there may well be cases where you will want to combine actions together.
+ Such a section then might look like:
+
+ { +handle-as-image +block }
+ # Block these as if they were images. Send no block page.
+ banners.example.com
+ media.example.com/.*banners
+ .example.com/images/ads/
+
+ You can trace this process for URL patterns and any given URL by visiting
+ http://config.privoxy.org/show-url-info.
+
+ Examples and more detail on this is provided in the Appendix,
+ Troubleshooting: Anatomy of an Action section.
+
+ --------------------------------------------------------------------------
+
+ 8.4. Patterns
+
+ As mentioned, Privoxy uses "patterns" to determine what actions might
+ apply to which sites and pages your browser attempts to access. These
+ "patterns" use wild card type pattern matching to achieve a high degree of
+ flexibility. This allows one expression to be expanded and potentially
+ match against many similar patterns.
+
+ Generally, an URL pattern has the form <domain>/<path>, where both the
+ <domain> and <path> are optional. (This is why the special / pattern
+ matches all URLs). Note that the protocol portion of the URL pattern (e.g.
+ http://) should not be included in the pattern. This is assumed already!
+
+ The pattern matching syntax is different for the domain and path parts of
+ the URL. The domain part uses a simple globbing type matching technique,
+ while the path part uses a more flexible "Regular Expressions (PCRE)"
+ based syntax.
+
+ 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. So ALL pages in this domain would be covered by the
+ scope of this action. Note that a simple example.com is different
+ and would NOT match.
+
+ www.example.com
+
+ means exactly the same. For domain-only patterns, the trailing /
+ may be omitted.
+
+ www.example.com/index.html$
+
+ matches all the documents on www.example.com whose name starts
+ with /index.html.
+
+ 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 anywhere.
+
+ index.html
+
+ matches nothing, since it would be interpreted as a domain name
+ and there is no top-level domain called .html. So its a mistake.
+
+ --------------------------------------------------------------------------
+
+ 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 with first-level domain com and second-level
+ domain example. For example www.example.com, example.com and
+ foo.bar.baz.example.com. Note that it wouldn't match if the
+ second-level domain was another-example.
+
+ www.
+
+ matches any domain that STARTS with www. (It also matches the
+ domain www but most of the time that doesn't matter.)
+
+ .example.
+
+ matches any domain that CONTAINS .example.. And, by the way, also
+ included would be any files or documents that exist within that
+ domain since no path limitations are specified. (Correctly
+ speaking: It matches any FQDN that contains example as a domain.)
+ This might be www.example.com, news.example.de, or
+ www.example.net/cgi/testing.pl for instance. All these cases are
+ matched.
+
+ Additionally, there are wild-cards that you can use in the domain names
+ themselves. These work similarly to shell globbing type wild-cards: "*"
+ represents zero or more arbitrary characters (this is equivalent to the
+ "Regular Expression" based syntax of ".*"), "?" represents any single
+ character (this is equivalent to the regular expression syntax of a simple
+ "."), and you can define "character classes" in square brackets which is
+ similar to the same regular expression technique. All of this can be
+ freely mixed:
+
+ 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.
+
+ While flexible, this is not the sophistication of full regular expression
+ based syntax.
+
+ --------------------------------------------------------------------------
+
+ 8.4.2. The Path Pattern
+
+ Privoxy uses Perl compatible (PCRE) "Regular Expression" based syntax
+ (through the PCRE library) for matching the path portion (after the
+ slash), and is thus more flexible.
+
+ 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://perldoc.perl.org/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.
+
+ .example.com/.*
+
+ Is equivalent to just ".example.com", since any documents within
+ that domain are matched with or without the ".*" regular
+ expression. This is redundant
+
+ .example.com/.*/index.html$
+
+ Will match any page in the domain of "example.com" that is named
+ "index.html", and that is part of some path. For example, it
+ matches "www.example.com/testing/index.html" but NOT
+ "www.example.com/index.html" because the regular expression called
+ for at least two "/'s", thus the path requirement. It also would
+ match "www.example.com/testing/index_html", because of the special
+ meta-character ".".
+
+ .example.com/(.*/)?index\.html$
+
+ This regular expression is conditional so it will match any page
+ named "index.html" regardless of path which in this case can have
+ one or more "/'s". And this one must contain exactly ".html" (but
+ does not have to end with that!).
+
+ .example.com/(.*/)(ads|banners?|junk)
+
+ This regular expression will match any path of "example.com" that
+ contains any of the words "ads", "banner", "banners" (because of
+ the "?") or "junk". The path does not have to end in these words,
+ just contain them.
+
+ .example.com/(.*/)(ads|banners?|junk)/.*\.(jpe?g|gif|png)$
+
+ This is very much the same as above, except now it must end in
+ either ".jpg", ".jpeg", ".gif" or ".png". So this one is limited
+ to common image formats.
+
+ There are many, many good examples to be found in default.action, and more
+ tutorials below in Appendix on regular expressions.
+
+ --------------------------------------------------------------------------
+
+ 8.4.3. The Tag Pattern
+
+ Tag patterns are used to change the applying actions based on the
+ request's tags. Tags can be created with either the client-header-tagger
+ or the server-header-tagger action.
+
+ Tag patterns have to start with "TAG:", so Privoxy can tell them apart
+ from URL patterns. Everything after the colon including white space, is
+ interpreted as a regular expression with path pattern syntax, except that
+ tag patterns aren't left-anchored automatically (Privoxy doesn't silently
+ add a "^", you have to do it yourself if you need it).
+
+ To match all requests that are tagged with "foo" your pattern line should
+ be "TAG:^foo$", "TAG:foo" would work as well, but it would also match
+ requests whose tags contain "foo" somewhere. "TAG: foo" wouldn't work as
+ it requires white space.
+
+ Sections can contain URL and tag patterns at the same time, but tag
+ patterns are checked after the URL patterns and thus always overrule them,
+ even if they are located before the URL patterns.
+
+ Once a new tag is added, Privoxy checks right away if it's matched by one
+ of the tag patterns and updates the action settings accordingly. As a
+ result tags can be used to activate other tagger actions, as long as these
+ other taggers look for headers that haven't already be parsed.
+
+ For example you could tag client requests which use the POST method, then
+ use this tag to activate another tagger that adds a tag if cookies are
+ sent, and then use a block action based on the cookie tag. This allows the
+ outcome of one action, to be input into a subsequent action. However if
+ you'd reverse the position of the described taggers, and activated the
+ method tagger based on the cookie tagger, no method tags would be created.
+ The method tagger would look for the request line, but at the time the
+ cookie tag is created, the request line has already been parsed.
+
+ While this is a limitation you should be aware of, this kind of
+ indirection is seldom needed anyway and even the example doesn't make too
+ much sense.
+
+ --------------------------------------------------------------------------
+
+ 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.
+
+ Actions fall into three categories:
+
+ * 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/5.0 (X11; U; FreeBSD i386; en-US;
+ rv:1.8.1.4) Gecko/20070602 Firefox/2.0.0.4}
+
+ * 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-filtering
+ proxy. You must specifically enable the privacy and blocking features you
+ need (although the provided default actions files will give a good
+ starting point).
+
+ Later defined action sections always over-ride earlier ones of the same
+ type. So exceptions to any rules you make, should come in the latter part
+ of the file (or in a file that is processed later when using multiple
+ actions files such as user.action). For multi-valued actions, the actions
+ are applied in the order they are specified. Actions files are processed
+ in the order they are defined in config (the default installation has
+ three actions files). It also quite possible for any given URL to match
+ more than one "pattern" (because of wildcards and regular expressions),
+ and thus to trigger more than one set of actions! Last match wins.
+
+ The list of valid Privoxy actions are:
+
+ --------------------------------------------------------------------------
+
+ 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 unwanted content
+
+ Effect:
+
+ Requests for URLs to which this action applies are blocked, i.e.
+ the requests are trapped by Privoxy and the requested URL is never
+ retrieved, but is answered locally with a substitute page or
+ image, as determined by the handle-as-image, set-image-blocker,
+ and handle-as-empty-document actions.
+
+ Type:
+
+ 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. Blocking is
+ a core feature, and one upon which various other features depend.
+
+ The filter action can perform a very similar task, by "blocking"
+ banner images and other content through rewriting the relevant
+ URLs in the document's HTML source, so they don't get requested in
+ the first place. Note that this is a totally different technique,
+ and it's easy to confuse the two.
+
+ Example usage (section):
+
+ {+block}
+ # 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/banners/
+
+ {+block +handle-as-empty-document}
+ # Block and then ignore
+ adserver.exampleclick.net/.*\.js$
+
+ --------------------------------------------------------------------------
+
+ 8.5.3. client-header-filter
+
+ Typical use:
+
+ Rewrite or remove single client headers.
+
+ Effect:
+
+ All client headers to which this action applies are filtered
+ on-the-fly through the specified regular expression based
+ substitutions.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ The name of a client-header filter, as defined in one of the
+ filter files.
+
+ Notes:
+
+ Client-header filters are applied to each header on its own, not
+ to all at once. This makes it easier to diagnose problems, but on
+ the downside you can't write filters that only change header x if
+ header y's value is z. You can do that by using tags though.
+
+ Client-header filters are executed after the other header actions
+ have finished and use their output as input.
+
+ If the request URL gets changed, Privoxy will detect that and use
+ the new one. This can be used to rewrite the request destination
+ behind the client's back, for example to specify a Tor exit relay
+ for certain requests.
+
+ Please refer to the filter file chapter to learn which
+ client-header filters are available by default, and how to create
+ your own.
+
+ Example usage (section):
+
+ {+client-header-filter{hide-tor-exit-notation}}
+ .exit/
+
+
+ --------------------------------------------------------------------------
+
+ 8.5.4. client-header-tagger
+
+ Typical use:
+
+ Block requests based on their headers.
+
+ Effect:
+
+ Client headers to which this action applies are filtered
+ on-the-fly through the specified regular expression based
+ substitutions, the result is used as tag.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ The name of a client-header tagger, as defined in one of the
+ filter files.
+
+ Notes:
+
+ Client-header taggers are applied to each header on its own, and
+ as the header isn't modified, each tagger "sees" the original.
+
+ Client-header taggers are the first actions that are executed and
+ their tags can be used to control every other action.
+
+ Example usage (section):
+
+ # Tag every request with the User-Agent header
+ {+client-header-tagger{user-agent}}
+ /
+
+
+ --------------------------------------------------------------------------
+
+ 8.5.5. content-type-overwrite
+
+ Typical use:
+
+ Stop useless download menus from popping up, or change the
+ browser's rendering mode
+
+ Effect:
+
+ Replaces the "Content-Type:" HTTP server header.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ Any string.
+
+ Notes:
+
+ The "Content-Type:" HTTP server header is used by the browser to
+ decide what to do with the document. The value of this header can
+ cause the browser to open a download menu instead of displaying
+ the document by itself, even if the document's format is supported
+ by the browser.
+
+ The declared content type can also affect which rendering mode the
+ browser chooses. If XHTML is delivered as "text/html", many
+ browsers treat it as yet another broken HTML document. If it is
+ send as "application/xml", browsers with XHTML support will only
+ display it, if the syntax is correct.
+
+ If you see a web site that proudly uses XHTML buttons, but sets
+ "Content-Type: text/html", you can use Privoxy to overwrite it
+ with "application/xml" and validate the web master's claim inside
+ your XHTML-supporting browser. If the syntax is incorrect, the
+ browser will complain loudly.
+
+ You can also go the opposite direction: if your browser prints
+ error messages instead of rendering a document falsely declared as
+ XHTML, you can overwrite the content type with "text/html" and
+ have it rendered as broken HTML document.
+
+ By default content-type-overwrite only replaces "Content-Type:"
+ headers that look like some kind of text. If you want to overwrite
+ it unconditionally, you have to combine it with force-text-mode.
+ This limitation exists for a reason, think twice before
+ circumventing it.
+
+ Most of the time it's easier to replace this action with a custom
+ server-header filter. It allows you to activate it for every
+ document of a certain site and it will still only replace the
+ content types you aimed at.
+
+ Of course you can apply content-type-overwrite to a whole site and
+ then make URL based exceptions, but it's a lot more work to get
+ the same precision.
+
+ Example usage (sections):
+
+ # Check if www.example.net/ really uses valid XHTML
+ { +content-type-overwrite{application/xml} }
+ www.example.net/
+
+ # but leave the content type unmodified if the URL looks like a style sheet
+ {-content-type-overwrite}
+ www.example.net/.*\.css$
+ www.example.net/.*style
+
+ --------------------------------------------------------------------------
+
+ 8.5.6. crunch-client-header
+
+ Typical use:
+
+ Remove a client header Privoxy has no dedicated action for.
+
+ Effect:
+
+ Deletes every header sent by the client that contains the string
+ the user supplied as parameter.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ Any string.
+
+ Notes:
+
+ This action allows you to block client headers for which no
+ dedicated Privoxy action exists. Privoxy will remove every client
+ header that contains the string you supplied as parameter.
+
+ Regular expressions are not supported and you can't use this
+ action to block different headers in the same request, unless they
+ contain the same string.
+
+ crunch-client-header is only meant for quick tests. If you have to
+ block several different headers, or only want to modify parts of
+ them, you should use a client-header filter.
+
+ +---------------------------------------------------------+
+ | Warning |
+ |---------------------------------------------------------|
+ | Don't block any header without understanding the |
+ | consequences. |
+ +---------------------------------------------------------+
+
+ Example usage (section):
+
+ # Block the non-existent "Privacy-Violation:" client header
+ { +crunch-client-header{Privacy-Violation:} }
+ /
+
+
+ --------------------------------------------------------------------------
+
+ 8.5.7. crunch-if-none-match
+
+ Typical use:
+
+ Prevent yet another way to track the user's steps between
+ sessions.
+
+ Effect:
+
+ Deletes the "If-None-Match:" HTTP client header.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ Removing the "If-None-Match:" HTTP client header is useful for
+ filter testing, where you want to force a real reload instead of
+ getting status code "304" which would cause the browser to use a
+ cached copy of the page.
+
+ It is also useful to make sure the header isn't used as a cookie
+ replacement (unlikely but possible).
+
+ Blocking the "If-None-Match:" header shouldn't cause any caching
+ problems, as long as the "If-Modified-Since:" header isn't blocked
+ or missing as well.
+
+ It is recommended to use this action together with
+ hide-if-modified-since and overwrite-last-modified.
+
+ Example usage (section):
+
+ # Let the browser revalidate cached documents but don't
+ # allow the server to use the revalidation headers for user tracking.
+ {+hide-if-modified-since{-60} \
+ +overwrite-last-modified{randomize} \
+ +crunch-if-none-match}
+ /
+
+ --------------------------------------------------------------------------
+
+ 8.5.8. crunch-incoming-cookies
+
+ Typical use:
+
+ Prevent the web server from setting HTTP cookies on your system
+
+ Effect:
+
+ Deletes any "Set-Cookie:" HTTP headers from server replies.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ This action is only concerned with incoming HTTP cookies. For
+ outgoing HTTP cookies, use crunch-outgoing-cookies. Use both to
+ disable HTTP cookies completely.
+
+ It makes no sense at all to use this action in conjunction with
+ the session-cookies-only action, since it would prevent the
+ session cookies from being set. See also filter-content-cookies.
+
+ Example usage:
+
+ +crunch-incoming-cookies
+
+ --------------------------------------------------------------------------
+
+ 8.5.9. crunch-server-header
+
+ Typical use:
+
+ Remove a server header Privoxy has no dedicated action for.
+
+ Effect:
+
+ Deletes every header sent by the server that contains the string
+ the user supplied as parameter.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ Any string.
+
+ Notes:
+
+ This action allows you to block server headers for which no
+ dedicated Privoxy action exists. Privoxy will remove every server
+ header that contains the string you supplied as parameter.
+
+ Regular expressions are not supported and you can't use this
+ action to block different headers in the same request, unless they
+ contain the same string.
+
+ crunch-server-header is only meant for quick tests. If you have to
+ block several different headers, or only want to modify parts of
+ them, you should use a custom server-header filter.
+
+ +---------------------------------------------------------+
+ | Warning |
+ |---------------------------------------------------------|
+ | Don't block any header without understanding the |
+ | consequences. |
+ +---------------------------------------------------------+
+
+ Example usage (section):
+
+ # Crunch server headers that try to prevent caching
+ { +crunch-server-header{no-cache} }
+ /
+
+ --------------------------------------------------------------------------
+
+ 8.5.10. crunch-outgoing-cookies
+
+ Typical use:
+
+ Prevent the web server from reading any HTTP cookies from your
+ system
+
+ Effect:
+
+ Deletes any "Cookie:" HTTP headers from client requests.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ This action is only concerned with outgoing HTTP cookies. For
+ incoming HTTP cookies, use crunch-incoming-cookies. Use both to
+ disable HTTP cookies completely.
+
+ It makes no sense at all to use this action in conjunction with
+ the session-cookies-only action, since it would prevent the
+ session cookies from being read.
+
+ Example usage:
+
+ +crunch-outgoing-cookies
+
+ --------------------------------------------------------------------------
+
+ 8.5.11. 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}
+
+ --------------------------------------------------------------------------
+
+ 8.5.12. 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 HTTP/1.1 features and requirements are
+ supported yet, so there is a chance you might need this action.
+
+ Example usage (section):
+
+ {+downgrade-http-version}
+ problem-host.example.com
+
+ --------------------------------------------------------------------------
+
+ 8.5.13. fast-redirects
+
+ Typical use:
+
+ Fool some click-tracking scripts and speed up indirect links.
+
+ Effect:
+
+ Detects redirection URLs and redirects the browser without
+ contacting the redirection server first.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ * "simple-check" to just search for the string "http://" to
+ detect redirection URLs.
+
+ * "check-decoded-url" to decode URLs (if necessary) before
+ searching for redirection URLs.
+
+ Notes:
+
+ Many sites, like yahoo.com, don't just link to other sites.
+ Instead, they will link to some script on their own servers,
+ giving the destination as a parameter, which will then redirect
+ you to the final target. URLs resulting from this scheme typically
+ look like:
+ "http://www.example.org/click-tracker.cgi?target=http%3a//www.example.net/".
+
+ Sometimes, there are even multiple consecutive redirects encoded
+ in the URL. These redirections via scripts make your web browsing
+ more traceable, since the server from which you follow such a link
+ can see where you go to. Apart from that, valuable bandwidth and
+ time is wasted, while your browser asks the server for one
+ redirect after the other. Plus, it feeds the advertisers.
+
+ This feature is currently not very smart and is scheduled for
+ improvement. If it is enabled by default, you will have to create
+ some exceptions to this action. It can lead to failures in several
+ ways:
+
+ Not every URLs with other URLs as parameters is evil. Some sites
+ offer a real service that requires this information to work. For
+ example a validation service needs to know, which document to
+ validate. fast-redirects assumes that every URL parameter that
+ looks like another URL is a redirection target, and will always
+ redirect to the last one. Most of the time the assumption is
+ correct, but if it isn't, the user gets redirected anyway.
+
+ Another failure occurs if the URL contains other parameters after
+ the URL parameter. The URL:
+ "http://www.example.org/?redirect=http%3a//www.example.net/&foo=bar".
+ contains the redirection URL "http://www.example.net/", followed
+ by another parameter. fast-redirects doesn't know that and will
+ cause a redirect to "http://www.example.net/&foo=bar". Depending
+ on the target server configuration, the parameter will be silently
+ ignored or lead to a "page not found" error. You can prevent this
+ problem by first using the redirect action to remove the last part
+ of the URL, but it requires a little effort.
+
+ To detect a redirection URL, fast-redirects only looks for the
+ string "http://", either in plain text (invalid but often used) or
+ encoded as "http%3a//". Some sites use their own URL encoding
+ scheme, encrypt the address of the target server or replace it
+ with a database id. In theses cases fast-redirects is fooled and
+ the request reaches the redirection server where it probably gets
+ logged.
+
+ Example usage:
+
+ { +fast-redirects{simple-check} }
+ one.example.com
+
+ { +fast-redirects{check-decoded-url} }
+ another.example.com/testing
+
+ --------------------------------------------------------------------------
+
+ 8.5.14. filter
+
+ Typical use:
+
+ Get rid of HTML and JavaScript annoyances, banner advertisements
+ (by size), do fun text replacements, add personalized effects,
+ etc.
+
+ Effect:
+
+ All instances of text-based type, most notably HTML and
+ JavaScript, to which this action applies, can be filtered
+ on-the-fly through the specified regular expression based
+ substitutions. (Note: as of version 3.0.3 plain text documents are
+ exempted from filtering, because web servers often use the
+ text/plain MIME type for all files whose type they don't know.)
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ The name of a content filter, as defined in the filter file.
+ Filters can be defined in one or more files as defined by the
+ filterfile option in the config file. default.filter is the
+ collection of filters supplied by the developers. Locally defined
+ filters should go in their own file, such as user.filter.
+
+ When used in its negative form, and without parameters, all
+ filtering is completely disabled.
+
+ Notes:
+
+ For your convenience, there are a number of pre-defined filters
+ available in the distribution filter file that you can use. See
+ the examples below for a list.
+
+ Filtering requires buffering the page content, which may appear to
+ slow down page rendering since nothing is displayed until all
+ content has passed the filters. (It does not really take longer,
+ but seems that way since the page is not incrementally displayed.)
+ This effect will be more noticeable on slower connections.
+
+ "Rolling your own" filters requires a knowledge of "Regular
+ Expressions" and "HTML". This is very powerful feature, and
+ potentially very intrusive. Filters should be used with caution,
+ and where an equivalent "action" is not available.
+
+ The amount of data that can be filtered is limited to the
+ buffer-limit option in the main config file. The default is 4096
+ KB (4 Megs). Once this limit is exceeded, the buffered data, and
+ all pending data, is passed through unfiltered.
+
+ Inappropriate MIME types, such as zipped files, are not filtered
+ at all. (Again, only text-based types except plain text).
+ Encrypted SSL data (from HTTPS servers) cannot be filtered either,
+ since this would violate the integrity of the secure transaction.
+ In some situations it might be necessary to protect certain text,
+ like source code, from filtering by defining appropriate -filter
+ exceptions.
+
+ Compressed content can't be filtered either, unless Privoxy is
+ compiled with zlib support (requires at least Privoxy 3.0.7), in
+ which case Privoxy will decompress the content before filtering
+ it.
+
+ If you use a Privoxy version without zlib support, but want
+ filtering to work on as much documents as possible, even those
+ that would normally be sent compressed, you must use the
+ prevent-compression action in conjunction with filter.
+
+ Content filtering can achieve some of the same effects as the
+ block action, i.e. it can be used to block ads and banners. But
+ the mechanism works quite differently. One effective use, is to
+ block ad banners based on their size (see below), since many of
+ these seem to be somewhat standardized.
+
+ Feedback with suggestions for new or improved filters is
+ particularly welcome!
+
+ The below list has only the names and a one-line description of
+ each predefined filter. There are more verbose explanations of
+ what these filters do in the filter file chapter.
+
+ Example usage (with filters from the distribution default.filter file).
+ See the Predefined Filters section for more explanation on each:
+
++filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse
+
++filter{js-events} # Kill all JS event bindings (Radically destructive! Only for extra nasty sites)
+
+ +filter{html-annoyances} # Get rid of particularly annoying HTML abuse
+
+ +filter{content-cookies} # Kill cookies that come in the HTML or JS content
+
++filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups)
+
++filter{unsolicited-popups} # Disable only unsolicited pop-up windows. Useful if your browser lacks this ability.
+
++filter{all-popups} # Kill all popups in JavaScript and HTML. Useful if your browser lacks this ability.
+
++filter{img-reorder} # Reorder attributes in <img> tags to make the banners-by-* filters more effective
+
+ +filter{banners-by-size} # Kill banners by size
+
++filter{banners-by-link} # Kill banners by their links to known clicktrackers
+
++filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking)
+
++filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap
+
++filter{jumping-windows} # Prevent windows from resizing and moving themselves
+
+ +filter{frameset-borders} # Give frames a border and make them resizeable
+
+ +filter{demoronizer} # Fix MS's non-standard use of standard charsets
+
+ +filter{shockwave-flash} # Kill embedded Shockwave Flash objects
+
+ +filter{quicktime-kioskmode} # Make Quicktime movies savable
+
+ +filter{fun} # Text replacements for subversive browsing fun!
+
+ +filter{crude-parental} # Crude parental filtering (demo only)
+
+ +filter{ie-exploits} # Disable a known Internet Explorer bug exploits
+
++filter{site-specifics} # Custom filters for specific site related problems
+
++filter{google} # Removes text ads and other Google specific improvements
+
++filter{yahoo} # Removes text ads and other Yahoo specific improvements
+
++filter{msn} # Removes text ads and other MSN specific improvements
+
+ +filter{blogspot} # Cleans up Blogspot blogs
+
++filter{no-ping} # Removes non-standard ping attributes from anchor and area tags
+
+ --------------------------------------------------------------------------
+
+ 8.5.15. force-text-mode
+
+ Typical use:
+
+ Force Privoxy to treat a document as if it was in some kind of
+ text format.
+
+ Effect:
+
+ Declares a document as text, even if the "Content-Type:" isn't
+ detected as such.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ As explained above, Privoxy tries to only filter files that are in
+ some kind of text format. The same restrictions apply to
+ content-type-overwrite. force-text-mode declares a document as
+ text, without looking at the "Content-Type:" first.
+
+ +---------------------------------------------------------+
+ | Warning |
+ |---------------------------------------------------------|
+ | Think twice before activating this action. Filtering |
+ | binary data with regular expressions can cause file |
+ | damage. |
+ +---------------------------------------------------------+
+
+ Example usage:
+
+ +force-text-mode
+
+
+ --------------------------------------------------------------------------
+
+ 8.5.16. forward-override
+
+ Typical use:
+
+ Change the forwarding settings based on User-Agent or request
+ origin
+
+ Effect:
+
+ Overrules the forward directives in the configuration file.
+
+ Type:
+
+ Multi-value.
+
+ Parameter:
+
+ * "forward ." to use a direct connection without any additional
+ proxies.
+
+ * "forward 127.0.0.1:8123" to use the HTTP proxy listening at
+ 127.0.0.1 port 8123.
+
+ * "forward-socks4a 127.0.0.1:9050 ." to use the socks4a proxy
+ listening at 127.0.0.1 port 9050. Replace "forward-socks4a"
+ with "forward-socks4" to use a socks4 connection (with local
+ DNS resolution) instead.
+
+ * "forward-socks4a 127.0.0.1:9050 proxy.example.org:8000" to
+ use the socks4a proxy listening at 127.0.0.1 port 9050 to
+ reach the HTTP proxy listening at proxy.example.org port
+ 8000. Replace "forward-socks4a" with "forward-socks4" to use
+ a socks4 connection (with local DNS resolution) instead.
+
+ Notes:
+
+ This action takes parameters similar to the forward directives in
+ the configuration file, but without the URL pattern. It can be
+ used as replacement, but normally it's only used in cases where
+ matching based on the request URL isn't sufficient.
+
+ +---------------------------------------------------------+
+ | Warning |
+ |---------------------------------------------------------|
+ | Please read the description for the forward directives |
+ | before using this action. Forwarding to the wrong |
+ | people will reduce your privacy and increase the |
+ | chances of man-in-the-middle attacks. |
+ | |
+ | If the ports are missing or invalid, default values |
+ | will be used. This might change in the future and you |
+ | shouldn't rely on it. Otherwise incorrect syntax causes |
+ | Privoxy to exit. |
+ | |
+ | Use the show-url-info CGI page to verify that your |
+ | forward settings do what you thought the do. |
+ +---------------------------------------------------------+
+
+ Example usage:
+
+ # Always use direct connections for requests previously tagged as
+ # "User-Agent: fetch libfetch/2.0" and make sure
+ # resuming downloads continues to work.
+ # This way you can continue to use Tor for your normal browsing,
+ # without overloading the Tor network with your FreeBSD ports updates
+ # or downloads of bigger files like ISOs.
+ # Note that HTTP headers are easy to fake and therefore their
+ # values are as (un)trustworthy as your clients and users.
+ {+forward-override{forward .} \
+ -hide-if-modified-since \
+ -overwrite-last-modified \
+ }
+ TAG:^User-Agent: fetch libfetch/2\.0$
+
+
+ --------------------------------------------------------------------------
+
+ 8.5.17. handle-as-empty-document
+
+ Typical use:
+
+ Mark URLs that should be replaced by empty documents if they get
+ blocked
+
+ Effect:
+
+ This action alone doesn't do anything noticeable. It just marks
+ URLs. If the block action also applies, the presence or absence of
+ this mark decides whether an HTML "BLOCKED" page, or an empty
+ document will be sent to the client as a substitute for the
+ blocked content. The empty document isn't literally empty, but
+ actually contains a single space.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ Some browsers complain about syntax errors if JavaScript documents
+ are blocked with Privoxy's default HTML page; this option can be
+ used to silence them. And of course this action can also be used
+ to eliminate the Privoxy BLOCKED message in frames.
+
+ The content type for the empty document can be specified with
+ content-type-overwrite{}, but usually this isn't necessary.
+
+ Example usage:
+
+ # Block all documents on example.org that end with ".js",
+ # but send an empty document instead of the usual HTML message.
+ {+block +handle-as-empty-document}
+ example.org/.*\.js$
+
+
+ --------------------------------------------------------------------------
+
+ 8.5.18. handle-as-image
+
+ Typical use:
+
+ Mark URLs as belonging to images (so they'll be replaced by images
+ if they do get blocked, rather than HTML pages)
+
+ Effect:
+
+ This action alone doesn't do anything noticeable. It just marks
+ URLs as images. If the block action also applies, the presence or
+ absence of this mark decides whether an HTML "blocked" page, or a
+ replacement image (as determined by the set-image-blocker action)
+ will be sent to the client as a substitute for the blocked
+ content.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ The below generic example section is actually part of
+ default.action. It marks all URLs with well-known image file name
+ extensions as images and should be left intact.
+
+ Users will probably only want to use the handle-as-image action in
+ conjunction with block, to block sources of banners, whose URLs
+ don't reflect the file type, like in the second example section.
+
+ Note that you cannot treat HTML pages as images in most cases. For
+ instance, (in-line) ad frames require an HTML page to be sent, or
+ they won't display properly. Forcing handle-as-image in this
+ situation will not replace the ad frame with an image, but lead to
+ error messages.
+
+ Example usage (sections):
+
+ # Generic image extensions:
+ #
+ {+handle-as-image}
+ /.*\.(gif|jpg|jpeg|png|bmp|ico)$
+
+ # 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
+
+ --------------------------------------------------------------------------
+
+ 8.5.19. hide-accept-language
+
+ Typical use:
+
+ Pretend to use different language settings.
+
+ Effect:
+
+ Deletes or replaces the "Accept-Language:" HTTP header in client
+ requests.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ Keyword: "block", or any user defined value.
+
+ Notes:
+
+ Faking the browser's language settings can be useful to make a
+ foreign User-Agent set with hide-user-agent more believable.
+
+ However some sites with content in different languages check the
+ "Accept-Language:" to decide which one to take by default.
+ Sometimes it isn't possible to later switch to another language
+ without changing the "Accept-Language:" header first.
+
+ Therefore it's a good idea to either only change the
+ "Accept-Language:" header to languages you understand, or to
+ languages that aren't wide spread.
+
+ Before setting the "Accept-Language:" header to a rare language,
+ you should consider that it helps to make your requests unique and
+ thus easier to trace. If you don't plan to change this header
+ frequently, you should stick to a common language.
+
+ Example usage (section):
+
+# Pretend to use Canadian language settings.
+{+hide-accept-language{en-ca} \
++hide-user-agent{Mozilla/5.0 (X11; U; OpenBSD i386; en-CA; rv:1.8.0.4) Gecko/20060628 Firefox/1.5.0.4} \
+}
+/
+
+ --------------------------------------------------------------------------
+
+ 8.5.20. hide-content-disposition
+
+ Typical use:
+
+ Prevent download menus for content you prefer to view inside the
+ browser.
+
+ Effect:
+
+ Deletes or replaces the "Content-Disposition:" HTTP header set by
+ some servers.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ Keyword: "block", or any user defined value.
+
+ Notes:
+
+ Some servers set the "Content-Disposition:" HTTP header for
+ documents they assume you want to save locally before viewing
+ them. The "Content-Disposition:" header contains the file name the
+ browser is supposed to use by default.
+
+ In most browsers that understand this header, it makes it
+ impossible to just view the document, without downloading it
+ first, even if it's just a simple text file or an image.
+
+ Removing the "Content-Disposition:" header helps to prevent this
+ annoyance, but some browsers additionally check the
+ "Content-Type:" header, before they decide if they can display a
+ document without saving it first. In these cases, you have to
+ change this header as well, before the browser stops displaying
+ download menus.
+
+ It is also possible to change the server's file name suggestion to
+ another one, but in most cases it isn't worth the time to set it
+ up.
+
+ This action will probably be removed in the future, use
+ server-header filters instead.
+
+ Example usage:
+
+ # Disarm the download link in Sourceforge's patch tracker
+ { -filter \
+ +content-type-overwrite{text/plain}\
+ +hide-content-disposition{block} }
+ .sourceforge.net/tracker/download\.php
+
+ --------------------------------------------------------------------------
+
+ 8.5.21. hide-if-modified-since
+
+ Typical use:
+
+ Prevent yet another way to track the user's steps between
+ sessions.
+
+ Effect:
+
+ Deletes the "If-Modified-Since:" HTTP client header or modifies
+ its value.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ Keyword: "block", or a user defined value that specifies a range
+ of hours.
+
+ Notes:
+
+ Removing this header is useful for filter testing, where you want
+ to force a real reload instead of getting status code "304", which
+ would cause the browser to use a cached copy of the page.
+
+ Instead of removing the header, hide-if-modified-since can also
+ add or subtract a random amount of time to/from the header's
+ value. You specify a range of minutes where the random factor
+ should be chosen from and Privoxy does the rest. A negative value
+ means subtracting, a positive value adding.
+
+ Randomizing the value of the "If-Modified-Since:" makes it less
+ likely that the server can use the time as a cookie replacement,
+ but you will run into caching problems if the random range is too
+ high.
+
+ It is a good idea to only use a small negative value and let
+ overwrite-last-modified handle the greater changes.
+
+ It is also recommended to use this action together with
+ crunch-if-none-match, otherwise it's more or less pointless.
+
+ Example usage (section):
+
+ # Let the browser revalidate but make tracking based on the time less likely.
+ {+hide-if-modified-since{-60} \
+ +overwrite-last-modified{randomize} \
+ +crunch-if-none-match}
+ /
+
+ --------------------------------------------------------------------------
+
+ 8.5.22. hide-forwarded-for-headers
+
+ Typical use:
+
+ Improve privacy by not forwarding the source of the request in the
+ HTTP headers.
+
+ Effect:
+
+ Deletes any existing "X-Forwarded-for:" HTTP header from client
+ requests.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ It is safe and recommended to leave this on.
+
+ Example usage:
+
+ +hide-forwarded-for-headers
+
+ --------------------------------------------------------------------------
+
+ 8.5.23. 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}
+
+ --------------------------------------------------------------------------
+
+ 8.5.24. hide-referrer
+
+ Typical use:
+
+ Conceal which link you followed to get to a particular site
+
+ Effect:
+
+ Deletes the "Referer:" (sic) HTTP header from the client request,
+ or replaces it with a forged one.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ * "conditional-block" to delete the header completely if the
+ host has changed.
+
+ * "conditional-forge" to forge the header if the host has
+ changed.
+
+ * "block" to delete the header unconditionally.
+
+ * "forge" to pretend to be coming from the homepage of the
+ server we are talking to.
+
+ * Any other string to set a user defined referrer.
+
+ Notes:
+
+ conditional-block is the only parameter, that isn't easily
+ detected in the server's log file. If it blocks the referrer, the
+ request will look like the visitor used a bookmark or typed in the
+ address directly.
+
+ Leaving the referrer unmodified for requests on the same host
+ allows the server owner to see the visitor's "click path", but in
+ most cases she could also get that information by comparing other
+ parts of the log file: for example the User-Agent if it isn't a
+ very common one, or the user's IP address if it doesn't change
+ between different requests.
+
+ Always blocking the referrer, or using a custom one, can lead to
+ failures on servers that check the referrer before they answer any
+ requests, in an attempt to prevent their content from being
+ embedded or linked to elsewhere.
+
+ Both conditional-block and forge will work with referrer checks,
+ as long as content and valid referring page are on the same host.
+ Most of the time that's the case.
+
+ hide-referer is an alternate spelling of hide-referrer and the two
+ can be can be freely substituted with each other. ("referrer" is
+ the correct English spelling, however the HTTP specification has a
+ bug - it requires it to be spelled as "referer".)
+
+ Example usage:
+
+ +hide-referrer{forge}
+
+ or
+
+ +hide-referrer{http://www.yahoo.com/}
+
+ --------------------------------------------------------------------------
+
+ 8.5.25. hide-user-agent
+
+ Typical use:
+
+ Try to conceal your type of browser and client operating system
+
+ Effect:
+
+ Replaces the value of the "User-Agent:" HTTP header in client
+ requests with the specified value.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ Any user-defined string.
+
+ Notes:
+
+ +---------------------------------------------------------+
+ | Warning |
+ |---------------------------------------------------------|
+ | This can lead to problems on web sites that depend on |
+ | looking at this header in order to customize their |
+ | content for different browsers (which, by the way, is |
+ | NOT the right thing to do: good web sites work |
+ | browser-independently). |
+ +---------------------------------------------------------+
+
+ Using this action in multi-user setups or wherever different types
+ of browsers will access the same Privoxy is not recommended. In
+ single-user, single-browser setups, you might use it to delete
+ your OS version information from the headers, because it is an
+ invitation to exploit known bugs for your OS. It is also
+ occasionally useful to forge this in order to access sites that
+ won't let you in otherwise (though there may be a good reason in
+ some cases). 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 :-).
+
+ More information on known user-agent strings can be found at
+ http://www.user-agents.org/ and
+ http://en.wikipedia.org/wiki/User_agent.
+
+ Example usage:
+
+ +hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}
+
+ --------------------------------------------------------------------------
+
+ 8.5.26. inspect-jpegs
+
+ Typical use:
+
+ Try to protect against a MS buffer over-run in JPEG processing
+
+ Effect:
+
+ Protect against a known exploit
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ See Microsoft Security Bulletin MS04-028. JPEG images are one of
+ the most common image types found across the Internet. The exploit
+ as described can allow execution of code on the target system,
+ giving an attacker access to the system in question by merely
+ planting an altered JPEG image, which would have no obvious
+ indications of what lurks inside. This action tries to prevent
+ this exploit if delivered through unencrypted HTTP.
+
+ Note that the exploit mentioned is several years old and it's
+ unlikely that your client is still vulnerable against it. This
+ action may be removed in one of the next releases.
+
+ Example usage:
+
+ +inspect-jpegs
+
+ --------------------------------------------------------------------------
+
+ 8.5.27. kill-popups
+
+ Typical use:
+
+ Eliminate those annoying pop-up windows (deprecated)
+
+ Effect:
+
+ While loading the document, replace JavaScript code that opens
+ pop-up windows with (syntactically neutral) dummy code on the fly.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ This action is basically a built-in, hardwired special-purpose
+ filter action, but there are important differences: For
+ kill-popups, the document need not be buffered, so it can be
+ incrementally rendered while downloading. But kill-popups doesn't
+ catch as many pop-ups as filter{all-popups} does and is not as
+ smart as filter{unsolicited-popups} is.
+
+ Think of it as a fast and efficient replacement for a filter that
+ you can use if you don't want any filtering at all. Note that it
+ doesn't make sense to combine it with any filter action, since as
+ soon as one filter applies, the whole document needs to be
+ buffered anyway, which destroys the advantage of the kill-popups
+ action over its filter equivalent.
+
+ Killing all pop-ups unconditionally is problematic. Many shops and
+ banks rely on pop-ups to display forms, shopping carts etc, and
+ the filter{unsolicited-popups} does a better job of catching only
+ the unwanted ones.
+
+ If the only kind of pop-ups that you want to kill are exit
+ consoles (those really nasty windows that appear when you close an
+ other one), you might want to use filter{js-annoyances} instead.
+
+ This action is most appropriate for browsers that don't have any
+ controls for unwanted pop-ups. Not recommended for general usage.
+
+ This action doesn't work very reliable and may be removed in
+ future releases.
+
+ Example usage:
+
+ +kill-popups
+
+ --------------------------------------------------------------------------
+
+ 8.5.28. limit-connect
+
+ Typical use:
+
+ Prevent abuse of Privoxy as a TCP proxy relay or disable SSL for
+ untrusted sites
+
+ Effect:
+
+ Specifies to which ports HTTP CONNECT requests are allowable.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ A comma-separated list of ports or port ranges (the latter using
+ dashes, with the minimum defaulting to 0 and the maximum to 65K).
+
+ Notes:
+
+ By default, i.e. if no limit-connect action applies, Privoxy only
+ allows HTTP CONNECT requests to port 443 (the standard, secure
+ HTTPS port). Use limit-connect if more fine-grained control is
+ desired for some or all destinations.
+
+ The CONNECT methods exists in HTTP to allow access to secure
+ websites ("https://" URLs) through proxies. It works very simply:
+ the proxy connects to the server on the specified port, and then
+ short-circuits its connections to the client and to the remote
+ server. This means CONNECT-enabled proxies can be used as TCP
+ relays very easily.
+
+ Privoxy relays HTTPS traffic without seeing the decoded content.
+ Websites can leverage this limitation to circumvent Privoxy's
+ filters. By specifying an invalid port range you can disable HTTPS
+ entirely. If you plan to disable SSL by default, consider enabling
+ treat-forbidden-connects-like-blocks as well, to be able to
+ quickly create exceptions.
+
+ Example usages:
+
++limit-connect{443} # This is the default and need not be specified.
++limit-connect{80,443} # Ports 80 and 443 are OK.
++limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK.
++limit-connect{-} # All ports are OK
++limit-connect{,} # No HTTPS/SSL traffic is allowed
+
+ --------------------------------------------------------------------------
+
+ 8.5.29. prevent-compression
+
+ Typical use:
+
+ Ensure that servers send the content uncompressed, so it can be
+ passed through filters.
+
+ Effect:
+
+ Removes the Accept-Encoding header which can be used to ask for
+ compressed transfer.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ More and more websites send their content compressed by default,
+ which is generally a good idea and saves bandwidth. But the
+ filter, deanimate-gifs and kill-popups actions need access to the
+ uncompressed data.
+
+ When compiled with zlib support (available since Privoxy 3.0.7),
+ content that should be filtered is decompressed on-the-fly and you
+ don't have to worry about this action. If you are using an older
+ Privoxy version, or one that hasn't been compiled with zlib
+ support, this action can be used to convince the server to send
+ the content uncompressed.
+
+ Most text-based instances compress very well, the size is seldom
+ decreased by less than 50%, for markup-heavy instances like news
+ feeds saving more than 90% of the original size isn't unusual.
+
+ Not using compression will therefore slow down the transfer, and
+ you should only enable this action if you really need it. As of
+ Privoxy 3.0.7 it's disabled in all predefined action settings.
+
+ Note that some (rare) ill-configured sites don't handle requests
+ for uncompressed documents correctly. Broken PHP applications tend
+ to send an empty document body, some IIS versions only send the
+ beginning of the content. If you enable prevent-compression per
+ default, you might want to add exceptions for those sites. See the
+ example for how to do that.
+
+ Example usage (sections):
+
+ # Selectively turn off compression, and enable a filter
+ #
+ { +filter{tiny-textforms} +prevent-compression }
+ # Match only these sites
+ .google.
+ sourceforge.net
+ sf.net
+
+ # Or instead, we could set a universal default:
+ #
+ { +prevent-compression }
+ / # Match all sites
+
+ # Then maybe make exceptions for broken sites:
+ #
+ { -prevent-compression }
+ .compusa.com/
+
+ --------------------------------------------------------------------------
+
+ 8.5.30. overwrite-last-modified
+
+ Typical use:
+
+ Prevent yet another way to track the user's steps between
+ sessions.
+
+ Effect:
+
+ Deletes the "Last-Modified:" HTTP server header or modifies its
+ value.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ One of the keywords: "block", "reset-to-request-time" and
+ "randomize"
+
+ Notes:
+
+ Removing the "Last-Modified:" header is useful for filter testing,
+ where you want to force a real reload instead of getting status
+ code "304", which would cause the browser to reuse the old version
+ of the page.
+
+ The "randomize" option overwrites the value of the
+ "Last-Modified:" header with a randomly chosen time between the
+ original value and the current time. In theory the server could
+ send each document with a different "Last-Modified:" header to
+ track visits without using cookies. "Randomize" makes it
+ impossible and the browser can still revalidate cached documents.
+
+ "reset-to-request-time" overwrites the value of the
+ "Last-Modified:" header with the current time. You could use this
+ option together with hided-if-modified-since to further customize
+ your random range.
+
+ The preferred parameter here is "randomize". It is safe to use, as
+ long as the time settings are more or less correct. If the server
+ sets the "Last-Modified:" header to the time of the request, the
+ random range becomes zero and the value stays the same. Therefore
+ you should later randomize it a second time with
+ hided-if-modified-since, just to be sure.
+
+ It is also recommended to use this action together with
+ crunch-if-none-match.
+
+ Example usage:
+
+ # Let the browser revalidate without being tracked across sessions
+ { +hide-if-modified-since{-60} \
+ +overwrite-last-modified{randomize} \
+ +crunch-if-none-match}
+ /
+
+ --------------------------------------------------------------------------
+
+ 8.5.31. redirect
+
+ Typical use:
+
+ Redirect requests to other sites.
+
+ Effect:
+
+ Convinces the browser that the requested document has been moved
+ to another location and the browser should get it from there.
+
+ Type:
+
+ Parameterized
+
+ Parameter:
+
+ An absolute URL or a single pcrs command.
+
+ Notes:
+
+ Requests to which this action applies are answered with a HTTP
+ redirect to URLs of your choosing. The new URL is either provided
+ as parameter, or derived by applying a single pcrs command to the
+ original URL.
+
+ This action will be ignored if you use it together with block. It
+ can be combined with fast-redirects{check-decoded-url} to redirect
+ to a decoded version of a rewritten URL.
+
+ Use this action carefully, make sure not to create redirection
+ loops and be aware that using your own redirects might make it
+ possible to fingerprint your requests.
+
+ Example usages:
+
+ # Replace example.com's style sheet with another one
+ { +redirect{http://localhost/css-replacements/example.com.css} }
+ example.com/stylesheet\.css
+
+ # Create a short, easy to remember nickname for a favorite site
+ # (relies on the browser accept and forward invalid URLs to Privoxy)
+ { +redirect{http://www.privoxy.org/user-manual/actions-file.html} }
+ a
+
+ # Always use the expanded view for Undeadly.org articles
+ # (Note the $ at the end of the URL pattern to make sure
+ # the request for the rewritten URL isn't redirected as well)
+ {+redirect{s@$@&mode=expanded@}}
+ undeadly.org/cgi\?action=article&sid=\d*$
+
+ --------------------------------------------------------------------------
+
+ 8.5.32. 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
+
+ --------------------------------------------------------------------------
+
+ 8.5.33. 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
+
+ --------------------------------------------------------------------------
+
+ 8.5.34. server-header-filter
+
+ Typical use:
+
+ Rewrite or remove single server headers.
+
+ Effect:
+
+ All server headers to which this action applies are filtered
+ on-the-fly through the specified regular expression based
+ substitutions.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ The name of a server-header filter, as defined in one of the
+ filter files.
+
+ Notes:
+
+ Server-header filters are applied to each header on its own, not
+ to all at once. This makes it easier to diagnose problems, but on
+ the downside you can't write filters that only change header x if
+ header y's value is z. You can do that by using tags though.
+
+ Server-header filters are executed after the other header actions
+ have finished and use their output as input.
+
+ Please refer to the filter file chapter to learn which
+ server-header filters are available by default, and how to create
+ your own.
+
+ Example usage (section):
+
+ {+server-header-filter{html-to-xml}}
+ example.org/xml-instance-that-is-delivered-as-html
+
+ {+server-header-filter{xml-to-html}}
+ example.org/instance-that-is-delivered-as-xml-but-is-not
+
+
+ --------------------------------------------------------------------------
+
+ 8.5.35. server-header-tagger
+
+ Typical use:
+
+ Enable or disable filters based on the Content-Type header.
+
+ Effect:
+
+ Server headers to which this action applies are filtered
+ on-the-fly through the specified regular expression based
+ substitutions, the result is used as tag.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ The name of a server-header tagger, as defined in one of the
+ filter files.
+
+ Notes:
+
+ Server-header taggers are applied to each header on its own, and
+ as the header isn't modified, each tagger "sees" the original.
+
+ Server-header taggers are executed before all other header actions
+ that modify server headers. Their tags can be used to control all
+ of the other server-header actions, the content filters and the
+ crunch actions (redirect and block).
+
+ Obviously crunching based on tags created by server-header taggers
+ doesn't prevent the request from showing up in the server's log
+ file.
+
+ Example usage (section):
+
+ # Tag every request with the content type declared by the server
+ {+server-header-tagger{content-type}}
+ /
+
+
+ --------------------------------------------------------------------------
+
+ 8.5.36. session-cookies-only
+
+ Typical use:
+
+ Allow only temporary "session" cookies (for the current browser
+ session only).
+
+ Effect:
+
+ Deletes the "expires" field from "Set-Cookie:" server headers.
+ Most browsers will not store such cookies permanently and forget
+ them in between sessions.
+
+ Type:
+
+ Boolean.
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ This is less strict than crunch-incoming-cookies /
+ crunch-outgoing-cookies and allows you to browse websites that
+ insist or rely on setting cookies, without compromising your
+ privacy too badly.
+
+ Most browsers will not permanently store cookies that have been
+ processed by session-cookies-only and will forget about them
+ between sessions. This makes profiling cookies useless, but won't
+ break sites which require cookies so that you can log in for
+ transactions. This is generally turned on for all sites, and is
+ the recommended setting.
+
+ It makes no sense at all to use session-cookies-only together with
+ crunch-incoming-cookies or crunch-outgoing-cookies. If you do,
+ cookies will be plainly killed.
+
+ Note that it is up to the browser how it handles such cookies
+ without an "expires" field. If you use an exotic browser, you
+ might want to try it out to be sure.
+
+ This setting also has no effect on cookies that may have been
+ stored previously by the browser before starting Privoxy. These
+ would have to be removed manually.
+
+ Privoxy also uses the content-cookies filter to block some types
+ of cookies. Content cookies are not effected by
+ session-cookies-only.
+
+ Example usage:
+
+ +session-cookies-only
+
+ --------------------------------------------------------------------------
+
+ 8.5.37. set-image-blocker
+
+ Typical use:
+
+ Choose the replacement for blocked images
+
+ Effect:
+
+ This action alone doesn't do anything noticeable. If both block
+ and handle-as-image also apply, i.e. if the request is to be
+ blocked as an image, then the parameter of this action decides
+ what will be sent as a replacement.
+
+ Type:
+
+ Parameterized.
+
+ Parameter:
+
+ * "pattern" to send a built-in checkerboard pattern image. The
+ image is visually decent, scales very well, and makes it
+ obvious where banners were busted.
+
+ * "blank" to send a built-in transparent image. This makes
+ banners disappear completely, but makes it hard to detect
+ where Privoxy has blocked images on a given page and
+ complicates troubleshooting if Privoxy has blocked innocent
+ images, like navigation icons.
+
+ * "target-url" to send a redirect to target-url. You can
+ redirect to any image anywhere, even in your local filesystem
+ via "file:///" URL. (But note that not all browsers support
+ redirecting to a local file system).
+
+ A good application of redirects is to use special
+ Privoxy-built-in URLs, which send the built-in images, as
+ target-url. This has the same visual effect as specifying
+ "blank" or "pattern" in the first place, but enables your
+ browser to cache the replacement image, instead of requesting
+ it over and over again.
+
+ Notes:
+
+ The URLs for the built-in images are
+ "http://config.privoxy.org/send-banner?type=type", where type is
+ either "blank" or "pattern".
+
+ There is a third (advanced) type, called "auto". It is NOT to be
+ used in set-image-blocker, but meant for use from filters. Auto
+ will select the type of image that would have applied to the
+ referring page, had it been an image.
+
+ Example usage:
+
+ Built-in pattern:
+
+ +set-image-blocker{pattern}
+
+ Redirect to the BSD daemon:
+
+ +set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif}
+
+ Redirect to the built-in pattern for better caching:
+
+ +set-image-blocker{http://config.privoxy.org/send-banner?type=pattern}
+
+ --------------------------------------------------------------------------
+
+ 8.5.38. treat-forbidden-connects-like-blocks
+
+ Typical use:
+
+ Block forbidden connects with an easy to find error message.
+
+ Effect:
+
+ If this action is enabled, Privoxy no longer makes a difference
+ between forbidden connects and ordinary blocks.
+
+ Type:
+
+ Boolean
+
+ Parameter:
+
+ N/A
+
+ Notes:
+
+ By default Privoxy answers forbidden "Connect" requests with a
+ short error message inside the headers. If the browser doesn't
+ display headers (most don't), you just see an empty page.
+
+ With this action enabled, Privoxy displays the message that is
+ used for ordinary blocks instead. If you decide to make an
+ exception for the page in question, you can do so by following the
+ "See why" link.
+
+ For "Connect" requests the clients tell Privoxy which host they
+ are interested in, but not which document they plan to get later.
+ As a result, the "Go there anyway" wouldn't work and is therefore
+ suppressed.
+
+ Example usage:
+
+ +treat-forbidden-connects-like-blocks
+
+ --------------------------------------------------------------------------
+
+ 8.5.39. 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.
+
+ 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!
+ #