X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=doc%2Ftext%2Fuser-manual.txt;h=f229e8838b814b03636527ab13a64fd6592994c3;hp=90b93b990b78dcb77abf2ba43a07bcbfa928303d;hb=72081f829de368392d04076728f8c991178c0080;hpb=47ebc96cd29a0e2de4c752e7b42006c27d365064 diff --git a/doc/text/user-manual.txt b/doc/text/user-manual.txt index 90b93b99..f229e883 100644 --- a/doc/text/user-manual.txt +++ b/doc/text/user-manual.txt @@ -1,14 +1,14 @@ -Privoxy User Manual +Privoxy 3.0.3 User Manual -Copyright © 2001, 2002 by Privoxy Developers +[ Copyright © 2001 - 2004 by Privoxy Developers ] -$Id: user-manual.sgml,v 1.105 2002/05/05 20:26:02 hal9 Exp $ +$Id: user-manual.txt,v 1.60.2.7 2004/01/30 23:46:57 oes Exp $ -The user manual gives users information on how to install, configure and use +The User Manual gives users information on how to install, configure and use Privoxy. Privoxy is a web proxy with advanced filtering capabilities for protecting -privacy, filtering web page content, managing cookies, controlling access, and +privacy, modifying web page content, managing cookies, controlling access, and removing ads, banners, pop-ups and other obnoxious Internet junk. Privoxy has a very flexible configuration and can be customized to suit individual needs and tastes. Privoxy has application for both stand-alone systems and multi-user @@ -16,52 +16,59 @@ networks. Privoxy is based on Internet Junkbuster (tm). -You can find the latest version of the user manual at http://www.privoxy.org/ +You can find the latest version of the User Manual at http://www.privoxy.org/ user-manual/. Please see the Contact section on how to contact the developers. ------------------------------------------------------------------------------- Table of Contents 1. Introduction - + 1.1. Features - + 2. Installation - + 2.1. Binary Packages - - 2.1.1. Red Hat and SuSE RPMs + + 2.1.1. Red Hat, SuSE and Conectiva RPMs 2.1.2. Debian 2.1.3. Windows 2.1.4. Solaris, NetBSD, FreeBSD, HP-UX 2.1.5. OS/2 - 2.1.6. Max OSX + 2.1.6. Mac OSX 2.1.7. AmigaOS - + 2.1.8. Gentoo + 2.2. Building from Source - + 2.3. Keeping your Installation Up-to-Date + 3. Note to Upgraders 4. Quickstart to Using Privoxy + + 4.1. Quickstart to Ad Blocking + 5. Starting Privoxy - - 5.1. RedHat and Debian - 5.2. SuSE - 5.3. Windows - 5.4. Solaris, NetBSD, FreeBSD, HP-UX and others - 5.5. OS/2 - 5.6. MAX OSX - 5.7. AmigaOS - 5.8. Command Line Options - + + 5.1. Red Hat and Conectiva + 5.2. Debian + 5.3. SuSE + 5.4. Windows + 5.5. Solaris, NetBSD, FreeBSD, HP-UX and others + 5.6. OS/2 + 5.7. Mac OSX + 5.8. AmigaOS + 5.9. Gentoo + 5.10. Command Line Options + 6. Privoxy Configuration - + 6.1. Controlling Privoxy with Your Web Browser 6.2. Configuration Files Overview - + 7. The Main Configuration File - + 7.1. Configuration and Log File Locations - + 7.1.1. confdir 7.1.2. logdir 7.1.3. actionsfile @@ -69,161 +76,157 @@ Table of Contents 7.1.5. logfile 7.1.6. jarfile 7.1.7. trustfile - + 7.2. Local Set-up Documentation - + 7.2.1. user-manual 7.2.2. trust-info-url 7.2.3. admin-address 7.2.4. proxy-info-url - + 7.3. Debugging - + 7.3.1. debug 7.3.2. single-threaded - + 7.4. Access Control and Security - + 7.4.1. listen-address 7.4.2. toggle 7.4.3. enable-remote-toggle 7.4.4. enable-edit-actions 7.4.5. ACLs: permit-access and deny-access 7.4.6. buffer-limit - + 7.5. Forwarding - + 7.5.1. forward 7.5.2. forward-socks4 and forward-socks4a 7.5.3. Advanced Forwarding Examples - + 7.6. Windows GUI Options - + 8. Actions Files - + 8.1. Finding the Right Mix 8.2. How to Edit 8.3. How Actions are Applied to URLs 8.4. Patterns - + 8.4.1. The Domain Pattern 8.4.2. The Path Pattern - + 8.5. Actions - - 8.5.1. +add-header - 8.5.2. +block - 8.5.3. +deanimate-gifs - 8.5.4. +downgrade-http-version - 8.5.5. +fast-redirects - 8.5.6. +filter - 8.5.7. +hide-forwarded-for-headers - 8.5.8. +hide-from-header - 8.5.9. +hide-referer - 8.5.10. +hide-user-agent - 8.5.11. +handle-as-image - 8.5.12. +set-image-blocker - 8.5.13. +limit-connect - 8.5.14. +prevent-compression - 8.5.15. +session-cookies-only - 8.5.16. +prevent-reading-cookies - 8.5.17. +prevent-setting-cookies - 8.5.18. +kill-popups - 8.5.19. +send-vanilla-wafer - 8.5.20. +send-wafer + + 8.5.1. add-header + 8.5.2. block + 8.5.3. crunch-incoming-cookies + 8.5.4. crunch-outgoing-cookies + 8.5.5. deanimate-gifs + 8.5.6. downgrade-http-version + 8.5.7. fast-redirects + 8.5.8. filter + 8.5.9. handle-as-image + 8.5.10. hide-forwarded-for-headers + 8.5.11. hide-from-header + 8.5.12. hide-referrer + 8.5.13. hide-user-agent + 8.5.14. kill-popups + 8.5.15. limit-connect + 8.5.16. prevent-compression + 8.5.17. send-vanilla-wafer + 8.5.18. send-wafer + 8.5.19. session-cookies-only + 8.5.20. set-image-blocker 8.5.21. Summary - 8.5.22. Sample Actions Files - + 8.6. Aliases - + 8.7. Actions Files Tutorial + + 8.7.1. default.action + 8.7.2. user.action + 9. The Filter File - - 9.1. The +filter Action - + + 9.1. Filter File Tutorial + 9.2. The Pre-defined Filters + 10. Templates 11. Contacting the Developers, Bug Reporting and Feature Requests - + 11.1. Get Support - 11.2. Report bugs - 11.3. Request new features - 11.4. Report ads or other filter problems + 11.2. Report Bugs + 11.3. Request New Features + 11.4. Report Ads or Other Actions-Related Problems 11.5. Other - + 12. Privoxy Copyright, License and History - + 12.1. License 12.2. History - + 12.3. Authors + 13. See Also 14. Appendix - + 14.1. Regular Expressions 14.2. Privoxy's Internal Pages - + 14.2.1. Bookmarklets - + 14.3. Chain of Events 14.4. Anatomy of an Action - -1. Introduction -This documentation is included with the current beta version of Privoxy, -v.2.9.15, and is mostly complete at this point. The most up to date reference -for the time being is still the comments in the source files and in the -individual configuration files. Development of version 3.0 is currently nearing -completion, and includes many significant changes and enhancements over earlier -versions. The target release date for stable v3.0 is "soon" ;-). +1. Introduction -Since this is a beta version, not all new features are well tested. This -documentation may be slightly out of sync as a result (especially with CVS -sources). And there may be bugs, though hopefully not many! +This documentation is included with the current stable version of Privoxy, +v.3.0.3. ------------------------------------------------------------------------------- 1.1. Features In addition to Internet Junkbuster's traditional features of ad and banner -blocking and cookie management, Privoxy provides new features, some of them -currently under development: +blocking and cookie management, Privoxy provides new features: * Integrated browser based configuration and control utility at http:// config.privoxy.org/ (shortcut: http://p.p/). Browser-based tracing of rule and filter effects. Remote toggling. - + * Web page content filtering (removes banners based on size, invisible "web-bugs", JavaScript and HTML annoyances, pop-up windows, etc.) - + * Modularized configuration that allows for standard settings and user settings to reside in separate files, so that installing updated actions - files won't overwrite idividual user settings. - + files won't overwrite individual user settings. + * HTTP/1.1 compliant (but not all optional 1.1 features are supported). - + * Support for Perl Compatible Regular Expressions in the configuration files, and generally a more sophisticated and flexible configuration syntax over previous versions. - + * Improved cookie management features (e.g. session based cookies). - + * GIF de-animation. - + * Bypass many click-tracking scripts (avoids script redirection). - + * Multi-threaded (POSIX and native threads). - + * User-customizable HTML templates for all proxy-generated pages (e.g. "blocked" page). - + * Auto-detection and re-reading of config file changes. - + * Improved signal handling, and a true daemon mode (Unix). - + * Every feature now controllable on a per-site or per-location basis, configuration more powerful and versatile over-all. - + * Many smaller new features added, limitations and bugs removed, and security holes fixed. - + ------------------------------------------------------------------------------- 2. Installation @@ -233,9 +236,9 @@ of operating systems, and as raw source code. For most users, we recommend using the packages, which can be downloaded from our Privoxy Project Page. Note: If you have a previous Junkbuster or Privoxy installation on your system, -you will need to remove it. Some platforms do this for you as part of their -installation procedure. (See below for your platform). In any case be sure to -backup your old configuration if it is valuable to you. See the note to +you will need to remove it. On some platforms, this may be done for you as part +of their installation procedure. (See below for your platform). In any case be +sure to backup your old configuration if it is valuable to you. See the note to upgraders section below. ------------------------------------------------------------------------------- @@ -246,9 +249,9 @@ How to install the binary packages depends on your operating system: ------------------------------------------------------------------------------- -2.1.1. Red Hat and SuSE RPMs +2.1.1. Red Hat, SuSE and Conectiva RPMs -RPMs can be installed with rpm -Uvh privoxy-2.9.15-1.rpm, and will use /etc/ +RPMs can be installed with rpm -Uvh privoxy-3.0.3-1.rpm, and will use /etc/ privoxy for the location of configuration files. Note that on Red Hat, Privoxy will not be automatically started on system boot. @@ -256,7 +259,7 @@ You will need to enable that using chkconfig, ntsysv, or similar methods. Note that SuSE will automatically start Privoxy in the boot process. If you have problems with failed dependencies, try rebuilding the SRC RPM: rpm ---rebuild privoxy-2.9.15-1.src.rpm;. This will use your locally installed +--rebuild privoxy-3.0.3-1.src.rpm. This will use your locally installed libraries and RPM version. Also note that if you have a Junkbuster RPM installed on your system, you need @@ -267,7 +270,8 @@ remove Junkbuster automatically, before installing Privoxy. 2.1.2. Debian -FIXME. +DEBs can be installed with apt-get install privoxy, and will use /etc/privoxy +for the location of configuration files. ------------------------------------------------------------------------------- @@ -282,14 +286,15 @@ installed Privoxy in. We do not use the registry of Windows. 2.1.4. Solaris, NetBSD, FreeBSD, HP-UX Create a new directory, cd to it, then unzip and untar the archive. For the -most part, you'll have to figure out where things go. FIXME. +most part, you'll have to figure out where things go. ------------------------------------------------------------------------------- 2.1.5. OS/2 First, make sure that no previous installations of Junkbuster and / or Privoxy -are left on your system. You can do this by +are left on your system. Check that no Junkbuster or Privoxy objects are in +your startup folder. Then, just double-click the WarpIN self-installing archive, which will guide you through the installation process. A shadow of the Privoxy executable will @@ -301,14 +306,23 @@ configuration files. ------------------------------------------------------------------------------- -2.1.6. Max OSX +2.1.6. Mac OSX + +Unzip the downloaded file (you can either double-click on the file from the +finder, or from the desktop if you downloaded it there). Then, double-click on +the package installer icon named Privoxy.pkg and follow the installation +process. Privoxy will be installed in the folder /Library/Privoxy. It will +start automatically whenever you start up. To prevent it from starting +automatically, remove or rename the folder /Library/StartupItems/Privoxy. + +To start Privoxy by hand, double-click on StartPrivoxy.command in the /Library/ +Privoxy folder. Or, type this command in the Terminal: -Unzip the downloaded package (you can either double-click on the file in the -finder, or on the desktop if you downloaded it there). Then, double-click on -the package installer icon and follow the installation process. Privoxy will be -installed in the subdirectory /Applications/Privoxy.app. Privoxy will set -itself up to start automatically on system bring-up via /System/Library/ -StartupItems/Privoxy. + /Library/Privoxy/StartPrivoxy.command + + + +You will be prompted for the administrator password. ------------------------------------------------------------------------------- @@ -318,11 +332,20 @@ Copy and then unpack the lha archive to a suitable location. All necessary files will be installed into Privoxy directory, including all configuration and log files. To uninstall, just remove this directory. -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). +------------------------------------------------------------------------------- + +2.1.8. Gentoo + +Gentoo source packages (Ebuilds) for Privoxy are contained in the Gentoo +Portage Tree (they are not on the download page, but there is a Gentoo section, +where you can see when a new Privoxy Version is added to the Portage Tree). + +Before installing Privoxy under Gentoo just do first emerge rsync to get the +latest changes from the Portage tree. With emerge privoxy you install the +latest version. + +Configuration files are in /etc/privoxy, the documentation is in /usr/share/doc +/privoxy-3.0.3 and the Log directory is in /var/log/privoxy. ------------------------------------------------------------------------------- @@ -341,34 +364,38 @@ compiler like gcc are required. When building from a source tarball (either release version or nightly CVS tarball), first unpack the source: - tar xzvf privoxy-2.9.15-beta-src* [.tgz or .tar.gz] - cd privoxy-2.9.15-beta + tar xzvf privoxy-3.0.3-src* [.tgz or .tar.gz] + cd privoxy-3.0.3 + For retrieving the current CVS sources, you'll need CVS installed. Note that sources from CVS are development quality, and may not be stable, or well tested. To download CVS source: - cvs -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa login - cvs -z3 -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa co current - cd current + cvs -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa login + cvs -z3 -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa co current + cd current + This will create a directory named current/, which will contain the source tree. Then, in either case, to build from unpacked tarball or CVS source: - autoheader - autoconf - ./configure # (--help to see options) - make # (the make from gnu, gmake for *BSD) - su - make -n install # (to see where all the files will go) - make install # (to really install) + autoheader + autoconf + ./configure # (--help to see options) + make # (the make from gnu, gmake for *BSD) + su + make -n install # (to see where all the files will go) + make install # (to really install) + If you have gnu make, you can have the first four steps automatically done for you by just typing: - make + make + in the freshly downloaded or unpacked source directory. @@ -378,6 +405,23 @@ 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 loose your personal changes and adjustments when updating to +the latest default.action file we strongly recommend that you use user.action +for your customization of Privoxy. See the Chapter on actions files for +details. + +------------------------------------------------------------------------------- + 3. Note to Upgraders There are very significant changes from earlier Junkbuster versions to the @@ -403,67 +447,235 @@ A quick list of things to be aware of before upgrading: * The default listening port is now 8118 due to a conflict with another service (NAS). - + * Some installers may remove earlier versions completely. Save any important configuration files! - + * Privoxy is controllable with a web browser at the special URL: http:// config.privoxy.org/ (Shortcut: http://p.p/). Many aspects of configuration can be done here, including temporarily disabling Privoxy. - - * The primary configuration file for cookie management, ad and banner - blocking, and many other aspects of Privoxy configuration is in the actions + + * The primary configuration files for cookie management, ad and banner + blocking, and many other aspects of Privoxy configuration are the actions files. It is strongly recommended to become familiar with the new actions concept below, before modifying these files. Locally defined rules should go into user.action. - + * Some installers may not automatically start Privoxy after installation. - + ------------------------------------------------------------------------------- 4. Quickstart to Using Privoxy - * If upgrading, please back up any configuration files. See the Note to - Upgraders Section. - - * Install Privoxy. See the Installation Section for platform specific + * If upgrading, from versions before 2.9.16, please back up any configuration + files. See the Note to Upgraders Section. + + * Install Privoxy. See the Installation Section below for platform specific information. - - * Start Privoxy, if the installation program has not done this already. See - the section Starting Privoxy. - - * Set your browser to use Privoxy as HTTP and HTTPS proxy by setting the - proxy configuration for address of localhost and port 8118. (Junkbuster and - earlier versions of Privoxy used port 8000.) See the section Starting - Privoxy. - - * Flush your browser's caches, to remove any cached ad images. - - * Enjoy surfing with enhanced comfort and privacy. You may want to customize - the user.action file to personalize your new browsing experience. See the - Configuration section for more configuration options, and how to further + + * 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. (Junkbuster + and earlier versions of Privoxy used port 8000.) See the section Starting + Privoxy below for more details on this. + + * 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. + + See the Configuration section for more configuration options, and how to customize your installation. - - * If you experience problems with sites that "misbehave", see the Anatomy of - an Action section in the Appendix. - + + * If you experience ads that slipped through, innocent images that are + blocked, or otherwise feel the need to fine-tune Privoxy's behaviour, 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 "Anatomy of an Action" + has hints how to debug actions that "misbehave". + + * For easy access to Privoxy's most important controls, drag the provided + Bookmarklets into your browser's personal toolbar. + * Please see the section Contacting the Developers on how to report bugs or problems with websites or to get help. - + + * Now enjoy surfing with enhanced 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. 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. + +The actions we need to know about for ad blocking are: block, handle-as-image, +and set-image-blocker: + + * block - 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. + + * 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. + + * 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:// - A redirect to any image anywhere of the user's choosing + (advanced usage). + +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. 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 + + [files-in-u] + + * 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. + ------------------------------------------------------------------------------- 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 proxy. The default is localhost -for the proxy address, and port 8118 (earlier versions used port 8000). This is -the one configuration step that must be done! +browser(s) to use Privoxy as a HTTP and HTTPS 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 (Mozilla) + +[proxy_setu] + +With Netscape (and Mozilla), this can be set under: + + Edit + |_ + Preferences + |_ + Advanced + |_ + Proxies + |_ + HTTP Proxy + +For Internet Explorer: -With Netscape (and Mozilla), this can be set under Edit -> Preferences -> -Advanced -> Proxies -> HTTP Proxy. For Internet Explorer: Tools -> Internet -Properties -> Connections -> LAN Setting. Then, check "Use Proxy" and fill in -the appropriate info (Address: localhost, Port: 8118). Include if HTTPS proxy -support too. + Tools + |_ + Internet Properties + |_ + 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. 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. You are @@ -476,26 +688,38 @@ Except on Win32 where it will try config.txt. ------------------------------------------------------------------------------- -5.1. RedHat and Debian +5.1. Red Hat and Conectiva -We use a script. Note that RedHat does not start Privoxy upon booting per +We use a script. Note that Red Hat does not start Privoxy upon booting per default. It will use the file /etc/privoxy/config as its main configuration -file. FIXME: Debian?? +file. + + # /etc/rc.d/init.d/privoxy start + + +------------------------------------------------------------------------------- + +5.2. Debian + +We use a script. Note that Debian starts Privoxy upon booting per default. It +will use the file /etc/privoxy/config as its main configuration file. + + # /etc/init.d/privoxy start - # /etc/rc.d/init.d/privoxy start ------------------------------------------------------------------------------- -5.2. SuSE +5.3. SuSE We use a script. It will use the file /etc/privoxy/config as its main configuration file. Note that SuSE starts Privoxy upon booting your PC. - # rcprivoxy start + # rcprivoxy start + ------------------------------------------------------------------------------- -5.3. Windows +5.4. 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. @@ -503,68 +727,110 @@ Note that Windows will automatically start Privoxy upon booting you PC. ------------------------------------------------------------------------------- -5.4. Solaris, NetBSD, FreeBSD, HP-UX and others +5.5. Solaris, NetBSD, FreeBSD, HP-UX and others Example Unix startup command: - # /usr/sbin/privoxy /etc/privoxy/config + # /usr/sbin/privoxy /etc/privoxy/config + + +------------------------------------------------------------------------------- + +5.6. 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. ------------------------------------------------------------------------------- -5.5. OS/2 +5.7. Mac OSX + +During installation, Privoxy is configured to start automatically when the +system restarts. To start Privoxy by hand, double-click on the +StartPrivoxy.command icon in the /Library/Privoxy folder. Or, type this command +in the Terminal: + + /Library/Privoxy/StartPrivoxy.command -FIXME. + + +You will be prompted for the administrator password. ------------------------------------------------------------------------------- -5.6. MAX OSX +5.8. AmigaOS -FIXME. +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). ------------------------------------------------------------------------------- -5.7. AmigaOS +5.9. 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 + -FIXME. ------------------------------------------------------------------------------- -5.8. Command Line Options +5.10. 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. + * 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. - + ------------------------------------------------------------------------------- 6. Privoxy Configuration @@ -579,15 +845,16 @@ easily with a 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: +without Internet access. You will see the following section: + + Privoxy Menu + ? View & change the current configuration + ? View the source code version numbers + ? View the request headers. + ? Look up which actions apply to a URL and why + ? Toggle Privoxy on or off + ? Documentation - Privoxy Menu - ? View & change the current configuration - ? View the source code version numbers - ? View the request headers. - ? Look up which actions apply to a URL and why - ? Toggle Privoxy on or off - 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 @@ -608,9 +875,7 @@ you can toggle Privoxy with one click from your browser. 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 name and number of configuration files -has changed from previous versions, and is subject to change as development -progresses. +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 @@ -618,30 +883,31 @@ 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 propably want to define sooner or later) are probably best + 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 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. - + * default.filter (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. - + Only one filter file may be defined. + 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 @@ -658,11 +924,6 @@ 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. -While under development, the configuration content is subject to change. The -below documentation may not be accurate by the time you read this. Also, what -constitutes a "default" setting, may change, so please check all your -configuration files on important issues. - ------------------------------------------------------------------------------- 7. The Main Configuration File @@ -694,276 +955,305 @@ 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. +files and actions files. ------------------------------------------------------------------------------- 7.1.1. 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 - + When development goes modular and multi-user, the blocker, filter, and per-user config will be stored in subdirectories of "confdir". For now, the configuration directory structure is flat, except for confdir/templates, where the HTML templates for CGI output reside (e.g. Privoxy's 404 error page). - + ------------------------------------------------------------------------------- 7.1.2. 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 - + ------------------------------------------------------------------------------- 7.1.3. actionsfile Specifies: - + The actions file(s) to use - + Type of value: - + File name, relative to confdir, without the .action suffix - -Default value: - + +Default values: + standard # Internal purposes, no editing recommended - - default # Main actions file - - user # User customizations - + + default # Main actions file + + user # User customizations + Effect if unset: - + No actions are taken at all. Simple 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 are where all the per site and per URL configuration is done for ad blocking, cookie management, privacy considerations, etc. There is no point in using Privoxy without at least one actions file. - + ------------------------------------------------------------------------------- 7.1.4. filterfile Specifies: - + The filter file 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: - - The "default.filter" file contains content modification rules that use - "regular expressions". These rules permit powerful changes on the content - of Web pages, e.g., you could disable your favorite JavaScript annoyances, + + The filter file contains content modification rules that use regular + expressions. These rules permit powerful changes on the content of Web + pages, e.g., you could disable your favorite JavaScript annoyances, re-write the actual displayed text, or just have some fun replacing "Microsoft" with "MicroSuck" wherever it appears on a Web page. - + + The +filter{name} actions rely on the relevant filter (name) to be defined + in the filter file! + + A pre-defined filter file called default.filter that contains a bunch of + handy filters for common problems is included in the distribution. See the + section on the filter action for a list. + ------------------------------------------------------------------------------- 7.1.5. logfile Specifies: - + The log file to use - + Type of value: - + File name, relative to logdir - + Default value: - + logfile (Unix) or privoxy.log (Windows) - + Effect if unset: - - No log file is used, all log messages go to the console (stderr). - + + No log file is used, all log messages go to the console (STDERR). + Notes: - - The windows version will additionally log to the console. - + 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) but in most cases you probably will never look at it. - + 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, a logrotate script has been included. - + On SuSE Linux systems, you can place a line like "/var/log/privoxy.* +1024k 644 nobody.nogroup" in /etc/logfiles, with the effect that cron.daily will automatically archive, gzip, and empty the log, when it exceeds 1M size. - + Any log files must be writable by whatever user Privoxy is being run as (default on UNIX, user id is "privoxy"). - + ------------------------------------------------------------------------------- 7.1.6. jarfile Specifies: - + The file to store intercepted cookies in - + Type of value: - + File name, relative to logdir - + Default value: - + jarfile (Unix) or privoxy.jar (Windows) - + Effect if unset: - + Intercepted cookies are not stored at all. - + Notes: - + The jarfile may grow to ridiculous sizes over time. - + ------------------------------------------------------------------------------- 7.1.7. trustfile Specifies: - + 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 whole trust mechanism is turned off. - + + The entire trust mechanism is turned off. + 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 named in the trustfile. You can also mark sites as trusted referrers - (with +), with the effect that access to untrusted sites will be granted, - if a link from a trusted referrer was used. The link target will then be - added to the "trustfile". Possible applications include limiting Internet - access for children. - - If you use + operator in the trust file, it may grow considerably over + 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. + + 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. 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). + + 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. + ------------------------------------------------------------------------------- 7.2. Local Set-up Documentation -If you intend to operate Privoxy for more users that just yourself, it might be +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. +that, your policies, etc. ------------------------------------------------------------------------------- 7.2.1. 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 used for help links from some of the internal CGI pages. The manual itself is normally packaged with the binary - distributions, so you propably want to set this to a locally installed + distributions, so you probably want to set this to a locally installed copy. For multi-user setups, you could provide a copy on a local webserver for all your users and use the corresponding URL here. - + Examples: - + Unix, in local filesystem: - - user-manual file:///usr/share/doc/privoxy-2.9.15/user-manual/ - + + user-manual file:///usr/share/doc/privoxy-3.0.3/user-manual/ + + + Windows, in local filesystem, must use forward slash notation: + + user-manual file:/c:/some-dir/privoxy-3.0.3/user-manual/ + + + Windows, UNC notation (with forward slashes): + + user-manual file://///some-server/some-path/privoxy-3.0.3/user-manual/ + + Any platform, on local webserver (called "local-webserver"): - - user-manual http://local-webserver/privoxy-user-manual/ - + + user-manual http://local-webserver/privoxy-user-manual/ + + +-----------------------------------------------------------------+ | Warning | |-----------------------------------------------------------------| @@ -976,89 +1266,89 @@ Notes: 7.2.2. 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 URL 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 above.) - + 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! - + ------------------------------------------------------------------------------- 7.2.3. admin-address Specifies: - + An email address to reach the proxy 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. - + ------------------------------------------------------------------------------- 7.2.4. 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 ;-) - + ------------------------------------------------------------------------------- 7.3. Debugging @@ -1072,80 +1362,82 @@ debugging. 7.3.1. debug Specifies: - - Key values that determine what information gets logged. - + + Key values that determine what information gets logged to the logfile. + Type of value: - + Integer values - + Default value: - + 12289 (i.e.: URLs plus informational and warning messages) - + Effect if unset: - + Nothing gets logged. - + Notes: - + The available debug levels are: - - debug 1 # show each GET/POST/CONNECT request - debug 2 # show each connection status - debug 4 # show I/O status - debug 8 # show header parsing - debug 16 # log all data into the logfile - debug 32 # debug force feature - debug 64 # debug regular expression filter - debug 128 # debug fast redirects - debug 256 # debug GIF de-animation - debug 512 # Common Log Format - debug 1024 # debug kill pop-ups - debug 4096 # Startup banner and warnings. - debug 8192 # Non-fatal errors - + + debug 1 # show each GET/POST/CONNECT request + debug 2 # show each connection status + debug 4 # show I/O status + debug 8 # show header parsing + debug 16 # log all data into the logfile + debug 32 # debug force feature + debug 64 # debug regular expression filter + debug 128 # debug fast 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 highly 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). - + The reporting of fatal errors (i.e. ones which crash Privoxy) is always on and cannot be disabled. - + If you want to use CLF (Common Log Format), you should set "debug 512" ONLY and not enable anything else. - + ------------------------------------------------------------------------------- 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 debug purposes and you should never need to use it. It will drastically reduce performance. - + ------------------------------------------------------------------------------- 7.4. Access Control and Security @@ -1158,252 +1450,260 @@ 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: - - localhost:8118 - + + 127.0.0.1:8118 + Effect if unset: - - Bind to localhost (127.0.0.1), port 8118. This is suitable and recommended + + 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 "ACLs" below), - or a firewall. - + 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 turn off the + enable-edit-actions and enable-remote-toggle options! + 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 - + + 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. behave like a - normal, content-neutral proxy. See enable-remote-toggle below. This is not - really useful anymore, since toggling is much easier via the web interface - than via editing the conf file. - + normal, content-neutral proxy where all ad blocking, filtering, etc are + disabled. See enable-remote-toggle below. This is not really useful + anymore, since toggling is much easier via the web interface than via + editing the conf file. + The windows version will only display the toggle icon in the system tray if this option is present. - + ------------------------------------------------------------------------------- 7.4.3. enable-remote-toggle Specifies: - + Whether or not the web-based toggle feature may be used - + Type of value: - + 0 or 1 - + Default value: - + 1 - + Effect if unset: - + The web-based toggle feature is disabled. - + Notes: - + When toggled off, Privoxy acts like a normal, content-neutral proxy, i.e. it acts as if none of the actions applied to any URL. - + For the time being, access to the toggle feature can not be controlled separately by "ACLs" or HTTP authentication, so that everybody who can access Privoxy (see "ACLs" and listen-address above) can toggle it for all users. So this option is not recommended for multi-user environments with untrusted users. - + Note that you must have compiled Privoxy with support for this feature, otherwise this option has no effect. - + ------------------------------------------------------------------------------- 7.4.4. enable-edit-actions Specifies: - + Whether or not the web-based actions file editor may be used - + Type of value: - + 0 or 1 - + Default value: - + 1 - + Effect if unset: - + The web-based actions file editor is disabled. - + Notes: - + For the time being, access to the editor can not be controlled separately by "ACLs" or HTTP authentication, so that everybody who can access Privoxy (see "ACLs" and listen-address above) can modify its configuration for all users. So this option is not recommended for multi-user environments with untrusted users. - + Note that you must have compiled Privoxy with support for this feature, otherwise this option has no effect. - + ------------------------------------------------------------------------------- 7.4.5. ACLs: permit-access and deny-access Specifies: - + Who can access what. - + Type of value: - + src_addr[/src_masklen] [dst_addr[/dst_masklen]] - + Where src_addr and dst_addr are IP addresses in dotted decimal notation or valid DNS names, and src_masklen and dst_masklen are subnet masks in CIDR notation, i.e. integer values from 2 to 30 representing the length (in bits) of the network address. The masks and the whole destination part are optional. - + Default value: - + Unset - + Effect if unset: - + Don't restrict access further than implied by listen-address - + Notes: - + Access controls are included at the request of ISPs and systems administrators, and are not usually needed by individual users. For a typical home user, it will normally suffice to ensure that Privoxy only - listens on the localhost or internal (home) network address by means of the - listen-address option. - + listens on the localhost (127.0.0.1) or internal (home) network address by + means of the listen-address option. + Please see the warnings in the FAQ that this proxy is not intended to be a substitute for a firewall or to encourage anyone to defer addressing basic security weaknesses. - + Multiple ACL lines are OK. If any ACLs are specified, then the Privoxy talks only to IP addresses that match at least one permit-access line and don't match any subsequent deny-access line. In other words, the last match wins, with the default being deny-access. - + If Privoxy is using a forwarder (see forward below) for a particular destination URL, the dst_addr that is examined is the address of the forwarder and NOT the address of the ultimate target. This is necessary because it may be impossible for the local Privoxy to determine the IP address of the ultimate target (that's often what gateways are used for). - + You should prefer using IP addresses over DNS names, because the address lookups take time. All DNS names must resolve! You can not use domain patterns like "*.org" or partial domain names. If a DNS name resolves to multiple IP addresses, only the first one is used. - + Denying access to particular sites by ACL may have undesired side effects if the site in question is hosted on a machine which also hosts other sites. - + Examples: - + Explicitly define the default behavior if no ACL and listen-address are set: "localhost" is OK. The absence of a dst_addr implies that all destination addresses are OK: - - permit-access localhost - + + permit-access localhost + + Allow any host on the same class C subnet as www.privoxy.org access to nothing but www.example.com: - - permit-access www.privoxy.org/24 www.example.com/32 - + + permit-access www.privoxy.org/24 www.example.com/32 + + Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere, with the exception that 192.168.45.73 may not access www.dirty-stuff.example.com: - - permit-access 192.168.45.64/26 - deny-access 192.168.45.73 www.dirty-stuff.example.com - + + permit-access 192.168.45.64/26 + deny-access 192.168.45.73 www.dirty-stuff.example.com + + ------------------------------------------------------------------------------- 7.4.6. buffer-limit Specifies: - + Maximum size of the buffer for content filtering. - + Type of value: - + Size in Kbytes - + Default value: - + 4096 - + Effect if unset: - + Use a 4MB (4096 KB) limit. - + Notes: - + For content filtering, i.e. the +filter and +deanimate-gif actions, it is necessary that Privoxy buffers the entire document body. This can be potentially dangerous, since a server could just keep sending data indefinitely and wait for your RAM to exhaust -- with nasty consequences. Hence this option. - + When a document buffer size reaches the buffer-limit, it is flushed to the client unfiltered and no further attempt to filter the rest of the document is made. Remember that there may be multiple threads running, which might require up to buffer-limit Kbytes each, unless you have enabled "single-threaded" above. - + ------------------------------------------------------------------------------- 7.5. Forwarding @@ -1424,103 +1724,109 @@ Also specified here are SOCKS proxies. Privoxy supports the SOCKS 4 and SOCKS 7.5.1. forward Specifies: - + To which parent HTTP proxy specific requests should be routed. - + Type of value: - - target_domain[:port] http_parent[/port] - - Where target_domain is a domain name pattern (see the chapter on domain - matching in the default.action file), http_parent is the address of the - parent HTTP proxy as an IP addresses in dotted decimal notation or as a - valid DNS name (or "." to denote "no forwarding", and the optional port - parameters are TCP ports, i.e. integer values from 1 to 64535 - + + 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 anonymizing proxy, except SSL on port 443 (which it doesn't handle): - - forward .* anon-proxy.example.org:8080 - forward :443 . - + + forward / anon-proxy.example.org:8080 + forward :443 . + + Everything goes to our example ISP's caching proxy, except for requests to that ISP's sites: - - forward .*. caching-proxy.example-isp.net:8000 - forward .example-isp.net . - + + forward / caching-proxy.example-isp.net:8000 + forward .example-isp.net . + + ------------------------------------------------------------------------------- 7.5.2. forward-socks4 and forward-socks4a Specifies: - + Through which SOCKS proxy (and to which parent HTTP proxy) specific requests should be routed. - + Type of value: - - target_domain[:port] socks_proxy[/port] http_parent[/port] - - Where target_domain is a domain name pattern (see the chapter on domain - matching in the default.action file), http_parent and socks_proxy are IP - addresses in dotted decimal notation or valid DNS names (http_parent may be - "." to denote "no HTTP forwarding"), and the optional port parameters are - TCP ports, i.e. integer values from 1 to 64535 - + + 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.example-isp.net:8080 - forward .example.com . - + + forward-socks4a / socks-gw.example.com:1080 www-cache.example-isp.net:8080 + forward .example.com . + + A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent looks like this: - - forward-socks4 .*. socks-gw.example.com:1080 . - + + forward-socks4 / socks-gw.example.com:1080 . + + ------------------------------------------------------------------------------- 7.5.3. Advanced Forwarding Examples @@ -1536,13 +1842,15 @@ look like this: host-a: - forward .*. . - forward .isp-b.net host-b:8118 + forward / . + forward .isp-b.net host-b:8118 + host-b: - forward .*. . - forward .isp-a.net host-a:8118 + forward / . + forward .isp-a.net host-a:8118 + Now, your users can set their browser's proxy to use either host-a or host-b and be able to browse the internal content of both isp-a and isp-b. @@ -1553,22 +1861,30 @@ 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 + # 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 for 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 + + ------------------------------------------------------------------------------- 7.6. Windows GUI Options @@ -1644,29 +1960,67 @@ console. The actions files are used to define what actions Privoxy takes for which URLs, and thus determine how ad images, cookies and various other aspects of HTTP content and transactions are handled, and on which sites (or even parts -thereof). There are three such files included with Privoxy (as of version -2.9.15), with differing purposes: +thereof). There are three such files included with Privoxy with differing +purposes: - * standard.action - is used by the web based editor, to set various - pre-defined sets of rules for the default actions section in - default.action. These have increasing levels of aggressiveness and have no - influence on your browsing unless you select them explicitly in the editor. - It is not recommend to edit this file. - * default.action - is the primary action file that sets the initial values for all actions. It is intended to provide a base level of functionality for Privoxy's array of features. So it is a set of broad rules that should work reasonably well for users everywhere. This is the file that the developers are keeping updated, and making available to users. - + * user.action - is intended to be for local site preferences and exceptions. As an example, if your ISP or your bank has specific requirements, and need special handling, this kind of thing should go here. This file will not be upgraded. - + + * standard.action - is used by the web based editor, to set various + pre-defined sets of rules for the default actions section in + default.action. These have increasing levels of aggressiveness and have no + influence on your browsing unless you select them explicitly in the editor. + It is not recommend to edit this file. + + The default profiles, and their associated actions, as pre-defined in + standard.action are: + + Table 1. Default Configurations + + +------------------------------------------------------------+ + | Feature | Cautious | Medium |Adventuresome| + |---------------------+-----------+------------+-------------| + |Ad-blocking by URL |yes |yes |yes | + |---------------------+-----------+------------+-------------| + |Ad-filtering by size |yes |yes |yes | + |---------------------+-----------+------------+-------------| + |GIF de-animation |no |yes |yes | + |---------------------+-----------+------------+-------------| + |Referer forging |no |yes |yes | + |---------------------+-----------+------------+-------------| + |Cookie handling |none |session-only|kill | + |---------------------+-----------+------------+-------------| + |Pop-up killing |unsolicited|unsolicited |all | + |---------------------+-----------+------------+-------------| + |Fast redirects |no |no |yes | + |---------------------+-----------+------------+-------------| + |HTML taming |yes |yes |yes | + |---------------------+-----------+------------+-------------| + |JavaScript taming |yes |yes |yes | + |---------------------+-----------+------------+-------------| + |Web-bug killing |yes |yes |yes | + |---------------------+-----------+------------+-------------| + |Fun text replacements|no |no |yes | + |---------------------+-----------+------------+-------------| + |Image tag reordering |no |no |yes | + |---------------------+-----------+------------+-------------| + |Ad-filtering by link |no |no |yes | + |---------------------+-----------+------------+-------------| + |Demoronizer |no |no |yes | + +------------------------------------------------------------+ + The list of actions files to be used are defined in the main configuration -file, and are processed in the order they are defined. The content of these can -all be viewed and edited from http://config.privoxy.org/show-status. +file, and are processed in the order they are defined (e.g. default.action is +typically process before user.action). The content of these can all be viewed +and edited from http://config.privoxy.org/show-status. An actions file typically has multiple sections. If you want to use "aliases" in an actions file, you have to place the (optional) alias section at the top @@ -1693,10 +2047,10 @@ some sites unusable that rely on these techniques to work properly. Finding the right mix of actions is not always easy and certainly a matter of personal taste. In general, it can be said that the more "aggressive" your default settings (in the top section of the actions file) are, the more exceptions for -"trusted" sites you will have to make later. If, for example, you want to kill -popup windows per default, you'll have to make exceptions from that rule for -sites that you regularly use and that require popups for actually useful -content, like maybe your bank, favorite shop, or newspaper. +"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 +puposes, 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 @@ -1712,7 +2066,9 @@ The easiest way to edit the actions files is with a browser by using our browser-based editor, which can be reached from http://config.privoxy.org/ show-status. The editor allows both fine-grained control over every single feature on a per-URL basis, and easy choosing from wholesale sets of defaults -like "Cautious", "Medium" or "Advanced". +like "Cautious", "Medium" or "Adventuresome". Warning: the "Adventuresome" +setting is not only more aggressive, but includes settings that are fun and +subversive, and which some may find of dubious merit! If you prefer plain text editing to GUIs, you can of course also directly edit the the actions files. Look at default.action which is richly commented. @@ -1733,8 +2089,9 @@ compared to all patterns in each action file file. Every time it matches, the list of applicable actions for the URL is incrementally updated, using the heading of the section in which the pattern is located. If multiple matches for the same URL set the same action differently, the last match wins. If not, the -effects are aggregated (e.g. a URL might match both the "+handle-as-image" and -"+block" actions). +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. You can trace this process for any given URL by visiting http:// config.privoxy.org/show-url-info. @@ -1745,33 +2102,41 @@ More detail on this is provided in the Appendix, Anatomy of an Action. 8.4. Patterns -Generally, a pattern has the form /, where both the and - are optional. (This is why the pattern / matches all URLs). +As mentioned, Privoxy uses "patterns" to determine what actions might apply to +which sites and pages your browser attempts to access. These "patterns" use +wild card type pattern matching to achieve a high degree of flexibility. This +allows one expression to be expanded and potentially match against many similar +patterns. + +Generally, a Privoxy pattern has the form /, where both the + and 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! www.example.com/ - + is a domain-only pattern and will match any request to www.example.com, regardless of which document on that server is requested. - + www.example.com - + means exactly the same. For domain-only patterns, the trailing / may be omitted. - + www.example.com/index.html - + matches only the single document /index.html on www.example.com. - + /index.html - + matches the document /index.html, regardless of the domain, i.e. on any web server. - + index.html - + matches nothing, since it would be interpreted as a domain name and there is no top-level domain called .html. - + ------------------------------------------------------------------------------- 8.4.1. The Domain Pattern @@ -1780,18 +2145,18 @@ The matching of the domain part offers some flexible options: if the domain starts or ends with a dot, it becomes unanchored at that end. For example: .example.com - + matches any domain that ENDS in .example.com - + www. - + matches any domain that STARTS with www. - + .example. - + matches any domain that CONTAINS .example. (Correctly speaking: It matches any FQDN that contains example as a domain.) - + Additionally, there are wild-cards that you can use in the domain names themselves. They work pretty similar to shell wild-cards: "*" stands for zero or more arbitrary characters, "?" stands for any single character, you can @@ -1799,23 +2164,23 @@ define character classes in square brackets and all of that can be freely mixed: ad*.example.com - + matches "adserver.example.com", "ads.example.com", etc but not "sfads.example.com" - + *ad*.example.com - + matches all of the above, and then some. - + .?pix.com - + matches www.ipix.com, pictures.epix.com, a.b.c.d.e.upix.com etc. - + www[1-9a-ez].example.c* - + matches www1.example.com, www4.example.cc, wwwd.example.cy, wwwz.example.com etc., but not wwww.example.com. - + ------------------------------------------------------------------------------- 8.4.2. The Path Pattern @@ -1833,7 +2198,7 @@ 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 +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. @@ -1847,7 +2212,7 @@ 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." +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 @@ -1858,39 +2223,42 @@ a section of the actions file. There are three classes of actions: * Boolean, i.e the action can only be "enabled" or "disabled". Syntax: - - +name # enable action name - -name # disable action name - + + +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 - + + +name{param} # enable action and set parameter to param, + # overwriting parameter from previous match if necessary + -name # disable action. The parameter can be omitted + + Note that if the URL matches multiple positive forms of a parameterized action, the last match wins, i.e. the params from earlier matches are simply ignored. - + Example: +hide-user-agent{ Mozilla 1.0 } - + * Multi-value. These look exactly like parameterized actions, but they behave differently: If the action applies multiple times to the same URL, but with different parameters, all the parameters from all matches are remembered. This is used for actions that can be executed for the same request repeatedly, like adding multiple headers, or filtering through multiple filters. Syntax: - - +name{param} # enable action and add param to the list of parameters - -name{param} # remove the parameter param from the list of parameters - # If it was the last one left, disable the action. + + +name{param} # enable action and add param to the list of parameters + -name{param} # remove the parameter param from the list of parameters + # If it was the last one left, disable the action. -name # disable this action completely and remove all parameters from the list - + + Examples: +add-header{X-Fun-Header: Some text} and +filter{html-annoyances} - + If nothing is specified in any actions file, no "actions" are taken. So in this case Privoxy would just be a normal, non-blocking, non-anonymizing proxy. You must specifically enable the privacy and blocking features you need (although @@ -1908,1177 +2276,2054 @@ The list of valid Privoxy actions are: ------------------------------------------------------------------------------- -8.5.1. +add-header +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. - -Purpose and typical uses: - - Send a user defined HTTP header to the web server. Can be used to confuse - log analysis. - -Possible values: - - Any value is possible. Validity of the defined HTTP headers is not checked. - It is recommended that you use the "X-" prefix for custom headers. - -Example usage: - - {+add-header{X-User-Tracking: sucks}} - .example.com - + +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 +8.5.2. block + +Typical use: + + Block ads or other obnoxious content + +Effect: -Type: - - Boolean. - -Purpose and typical uses: - Requests for URLs to which this action applies are blocked, i.e. the requests are not forwarded to the remote server, but answered locally with - a substitute page or image, as determined by the handle-as-image and - set-image-blocker actions. It is typically used to block ads or other - obnoxious content. - -Possible values: - + a substitute page or image, as determined by the handle-as-image and + set-image-blocker actions. + +Type: + + Boolean. + +Parameter: + N/A - + +Notes: + + Privoxy sends a special "BLOCKED" page for requests to blocked pages. This + page contains links to find out why the request was blocked, and a + click-through to the blocked content (the latter only if compiled with the + force feature enabled). The "BLOCKED" page adapts to the available screen + space -- it displays full-blown if space allows, or miniaturized and + text-only if loaded into a small frame or window. If you are using Privoxy + right now, you can take a look at the "BLOCKED" page. + + A very important exception occurs if both block and handle-as-image, apply + to the same request: it will then be replaced by an image. If + set-image-blocker (see below) also applies, the type of image will be + determined by its parameter, if not, the standard checkerboard pattern is + sent. + + It is important to understand this process, in order to understand how + Privoxy deals with ads and other unwanted content. + + The filter action can perform a very similar task, by "blocking" banner + images and other content through rewriting the relevant URLs in the + document's HTML source, so they don't get requested in the first place. + Note that this is a totally different technique, and it's easy to confuse + the two. + +Example usage (section): + + {+block} # Block and replace with "blocked" page + .nasty-stuff.example.com + + {+block +handle-as-image} # Block and replace with image + .ad.doubleclick.net + .ads.r.us + + +------------------------------------------------------------------------------- + +8.5.3. crunch-incoming-cookies + +Typical use: + + Prevent the web server from setting any cookies on your system + +Effect: + + Deletes any "Set-Cookie:" HTTP headers from server replies. + +Type: + + Boolean. + +Parameter: + + N/A + +Notes: + + This action is only concerned with incoming cookies. For outgoing cookies, + use crunch-outgoing-cookies. Use both to disable cookies completely. + + It makes no sense at all to use this action in conjunction with the + session-cookies-only action, since it would prevent the session cookies + from being set. See also filter-content-cookies. + Example usage: - - {+block} - .banners.example.com - .ads.r.us - - + + +crunch-incoming-cookies + + +------------------------------------------------------------------------------- + +8.5.4. crunch-outgoing-cookies + +Typical use: + + Prevent the web server from reading any cookies from your system + +Effect: + + Deletes any "Cookie:" HTTP headers from client requests. + +Type: + + Boolean. + +Parameter: + + N/A + Notes: - - If a URL matches one of the blocked patterns, Privoxy will intercept the - URL and display its special "BLOCKED" page instead. If there is sufficient - space, a large red banner will appear with a friendly message about why the - page was blocked, and a way to go there anyway. If there is insufficient - space a smaller "BLOCKED" page will appear without the red banner. Click - here to view the default blocked HTML page (Privoxy must be running for - this to work as intended!). - - A very important exception is if the URL matches both "+block" and - "+handle-as-image", then it will be handled by "+set-image-blocker" (see - below). It is important to understand this process, in order to understand - how Privoxy is able to deal with ads and other objectionable content. - - The "+filter" action can also perform some of the same functionality as - "+block", but by virtue of very different programming techniques, and is - most often used for different reasons. - + + This action is only concerned with outgoing cookies. For incoming cookies, + use crunch-incoming-cookies. Use both to disable cookies completely. + + It makes no sense at all to use this action in conjunction with the + session-cookies-only action, since it would prevent the session cookies + from being read. + +Example usage: + + +crunch-outgoing-cookies + + ------------------------------------------------------------------------------- -8.5.3. +deanimate-gifs +8.5.5. deanimate-gifs + +Typical use: + + Stop those annoying, distracting animated GIF images. + +Effect: + + De-animate GIF animations, i.e. reduce them to their first or last image. Type: - + Parameterized. - -Typical uses: - - To stop those annoying, distracting animated GIF images. - -Possible values: - + +Parameter: + "last" or "first" - -Example usage: - - {+deanimate-gifs{last}} - .example.com - - + Notes: - - De-animate all animated GIF images, i.e. reduce them to their last frame. + 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). - -------------------------------------------------------------------------------- -8.5.4. +downgrade-http-version + 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. -Type: - - Boolean. - -Typical uses: - - "+downgrade-http-version" will downgrade HTTP/1.1 client requests to HTTP/ - 1.0 and downgrade the responses as well. - -Possible values: - - N/A - Example usage: - - {+downgrade-http-version} - .example.com - - -Notes: - - Use this action for servers that use HTTP/1.1 protocol features that - Privoxy doesn't handle well yet. HTTP/1.1 is only partially implemented. - Default is not to downgrade requests. This is an infrequently needed - action, and is used to help with rare problem sites only. - + + +deanimate-gifs{last} + + ------------------------------------------------------------------------------- -8.5.5. +fast-redirects +8.5.6. downgrade-http-version + +Typical use: + + Work around (very rare) problems with HTTP/1.1 + +Effect: + + Downgrades HTTP/1.1 client requests and server replies to HTTP/1.0. + +Type: -Type: - Boolean. - -Typical uses: - - The "+fast-redirects" action enables interception of "redirect" requests - from one server to another, which are used to track users.Privoxy can cut - off all but the last valid URL in a redirect request and send a local - redirect back to your browser without contacting the intermediate site(s). - -Possible values: - + +Parameter: + N/A - -Example usage: - - {+fast-redirects} - .example.com - - + Notes: - + + This is a left-over from the time when Privoxy didn't support important + HTTP/1.1 features well. It is left here for the unlikely case that you + experience HTTP/1.1 related problems with some server out there. Not all + (optional) HTTP/1.1 features are supported yet, so there is a chance you + might need this action. + +Example usage (section): + + {+downgrade-http-version} + problem-host.example.com + + +------------------------------------------------------------------------------- + +8.5.7. fast-redirects + +Typical use: + + Fool some click-tracking scripts and speed up indirect links + +Effect: + + Cut off all but the last valid URL from requests. + +Type: + + Boolean. + +Parameter: + + N/A + +Notes: + Many sites, like yahoo.com, don't just link to other sites. Instead, they - will link to some script on their own server, giving the destination as a + will link to some script on their own servers, giving the destination as a parameter, which will then redirect you to the final target. URLs resulting - from this scheme typically look like: http://some.place/some_script?http:// - some.where-else. - + from this scheme typically look like: http://some.place/click-tracker.cgi? + target=http://some.where.else. + Sometimes, there are even multiple consecutive redirects encoded in the URL. These redirections via scripts make your web browsing more traceable, since the server from which you follow such a link can see where you go to. Apart from that, valuable bandwidth and time is wasted, while your browser ask the server for one redirect after the other. Plus, it feeds the advertisers. - - This is a normally "on" feature, and often requires exceptions for sites - that are sensitive to defeating this mechanism. - + + This feature is currently not very smart and is scheduled for improvement. + It is likely to break some sites. You should expect to need possibly many + exceptions to this action, if it is enabled by default in default.action. + Some sites just don't work without it. + +Example usage: + + {+fast-redirects} + + ------------------------------------------------------------------------------- -8.5.6. +filter +8.5.8. filter + +Typical use: + + Get rid of HTML and JavaScript annoyances, banner advertisements (by size), + do fun text replacements, etc. + +Effect: + + All files of text-based type, most notably HTML and JavaScript, to which + this action applies, are filtered on-the-fly through the specified regular + expression based substitutions. (Note: as of version 3.0.3 plain text + documents are exempted from filtering, because web servers often use the + text/plain MIME type for all files whose type they don't know.) Type: - + Parameterized. - -Typical uses: - - Apply page filtering as defined by named sections of the default.filter - file to the specified site(s). "Filtering" can be any modification of the - raw page content, including re-writing or deletion of content. - -Possible values: - - "+filter" must include the name of one of the section identifiers from - default.filter (or whatever filterfile is specified in config). - -Example usage (from the current default.filter): - - +filter{html-annoyances}: Get rid of particularly annoying HTML abuse. - - +filter{js-annoyances}: Get rid of particularly annoying JavaScript abuse - - +filter{content-cookies}: Kill cookies that come in the HTML or JS content - - +filter{popups}: Kill all popups in JS and HTML - - +filter{frameset-borders}: Give frames a border and make them resizable - - +filter{webbugs}: Squish WebBugs (1x1 invisible GIFs used for user - tracking) - - +filter{refresh-tags}: Kill automatic refresh tags (for dial-on-demand - setups) - - +filter{fun}: Text replacements for subversive browsing fun! - - +filter{nimda}: Remove Nimda (virus) code. - - +filter{banners-by-size}: Kill banners by size (very efficient!) - - +filter{shockwave-flash}: Kill embedded Shockwave Flash objects - - +filter{crude-parental}: Kill all web pages that contain the words "sex" or - "warez" - + +Parameter: + + The name of a filter, as defined in the filter file (typically + default.filter, set by the filterfile option in the config file). When used + in its negative form, and without parameters, filtering is completely + disabled. + Notes: - - This is potentially a very powerful feature! And requires a knowledge of - regular expressions if you want to "roll your own". Filtering operates on a - line by line basis throughout the entire page. - + + 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. - - Filtering can achieve some of the effects as the "+block" action, i.e. it - can be used to block ads and banners. In the overall scheme of things, - filtering is one of the first things "Privoxy" does with a web page. So - other most other actions are applied to the already "filtered" page. - + + This is very powerful feature, but "rolling your own" filters requires a + knowledge of regular expressions and HTML. + + The amount of data that can be filtered is limited to the buffer-limit + option in the main config file. The default is 4096 KB (4 Megs). Once this + limit is exceeded, the buffered data, and all pending data, is passed + through unfiltered. + + Inadequate MIME types, such as zipped files, are not filtered at all. + (Again, only text-based types except plain text). Encrypted SSL data (from + HTTPS servers) cannot be filtered either, since this would violate the + integrity of the secure transaction. In some situations it might be + necessary to protect certain text, like source code, from filtering by + defining appropriate -filter sections. + + At this time, Privoxy cannot (yet!) uncompress compressed documents. If you + want filtering to work on all documents, even those that would normally be + sent compressed, use the prevent-compression action in conjunction with + filter. + + Filtering can achieve some of the same effects as the block action, i.e. it + can be used to block ads and banners. But the mechanism works quite + differently. One effective use, is to block ad banners based on their size + (see below), since many of these seem to be somewhat standardized. + + Feedback with suggestions for new or improved filters is particularly + welcome! + + The below list has only the names and a one-line description of each + predefined filter. There are more verbose explanations of what these + filters do in the filter file chapter. + +Example usage (with filters from the distribution default.filter file). See the + Predefined Filters section for more explanation on each: + + +filter{js-annoyances} # Get rid of particularly annoying JavaScript abuse + + + +filter{js-events} # Kill all JS event bindings (Radically destructive! Only for extra nasty sites) + + + +filter{html-annoyances} # Get rid of particularly annoying HTML abuse + + + +filter{content-cookies} # Kill cookies that come in the HTML or JS content + + + +filter{refresh-tags} # Kill automatic refresh tags (for dial-on-demand setups) + + + +filter{unsolicited-popups} # Disable only unsolicited pop-up windows + + + +filter{all-popups} # Kill all popups in JavaScript and HTML + + + +filter{img-reorder} # Reorder attributes in tags to make the banners-by-* filters more effective + + + +filter{banners-by-size} # Kill banners by size + + + +filter{banners-by-link} # Kill banners by their links to known clicktrackers + + + +filter{webbugs} # Squish WebBugs (1x1 invisible GIFs used for user tracking) + + + +filter{tiny-textforms} # Extend those tiny textareas up to 40x80 and kill the hard wrap + + + +filter{jumping-windows} # Prevent windows from resizing and moving themselves + + + +filter{frameset-borders} # Give frames a border and make them resizable + + + +filter{demoronizer} # Fix MS's non-standard use of standard charsets + + + +filter{shockwave-flash} # Kill embedded Shockwave Flash objects + + + +filter{quicktime-kioskmode} # Make Quicktime movies saveable + + + +filter{fun} # Text replacements for subversive browsing fun! + + + +filter{crude-parental} # Crude parental filtering (demo only) + + + +filter{ie-exploits} # Disable some known Internet Explorer bug exploits + + ------------------------------------------------------------------------------- -8.5.7. +hide-forwarded-for-headers +8.5.9. handle-as-image + +Typical use: + + Mark URLs as belonging to images (so they'll be replaced by images if they + get blocked) + +Effect: + + This action alone doesn't do anything noticeable. It just marks URLs as + images. If the block action also applies, the presence or absence of this + mark decides whether an HTML "blocked" page, or a replacement image (as + determined by the set-image-blocker action) will be sent to the client as a + substitute for the blocked content. Type: - + Boolean. - -Typical uses: - - Block any existing X-Forwarded-for HTTP header, and do not add a new one. - -Possible values: - + +Parameter: + N/A - -Example usage: - - {+hide-forwarded-for-headers} - .example.com - - + Notes: - - It is fairly safe to leave this on. It does not seem to break many sites. - + + 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 + + ------------------------------------------------------------------------------- -8.5.8. +hide-from-header +8.5.10. hide-forwarded-for-headers + +Typical use: + + Improve privacy by hiding the true source of the request + +Effect: + + Deletes any existing "X-Forwarded-for:" HTTP header from client requests, + and prevents adding a new one. Type: - - Parameterized. - -Typical uses: - - To block the browser from sending your email address in a "From:" header. - -Possible values: - - Keyword: "block", or any user defined value. - -Example usage: - - {+hide-from-header{block}} - .example.com - - + + Boolean. + +Parameter: + + N/A + 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 send to the web server. - -------------------------------------------------------------------------------- -8.5.9. +hide-referer + It is fairly safe to leave this on. + + This action is scheduled for improvement: It should be able to generate + forged "X-Forwarded-for:" headers using random IP addresses from a + specified network, to make successive requests from the same client look + like requests from a pool of different users sharing the same proxy. -Type: - - Parameterized. - -Typical uses: - - Don't send the "Referer:" (sic) HTTP header to the web site. Or, - alternately send a forged header instead. - -Possible values: - - Prevent the header from being sent with the keyword, "block". Or, "forge" a - URL to one from the same server as the request. Or, set to user defined - value of your choice. - Example usage: - - {+hide-referer{forge}} - .example.com - - -Notes: - - "forge" is the preferred option here, since some servers will not send - images back otherwise. - - "+hide-referrer" is an alternate spelling of "+hide-referer". It has the - exact same parameters, and can be freely mixed with, "+hide-referer". - ("referrer" is the correct English spelling, however the HTTP specification - has a bug - it requires it to be spelled as "referer".) - + + +hide-forwarded-for-headers + + ------------------------------------------------------------------------------- -8.5.10. +hide-user-agent +8.5.11. hide-from-header + +Typical use: + + Keep your (old and ill) browser from telling web servers your email address + +Effect: + + Deletes any existing "From:" HTTP header, or replaces it with the specified + string. Type: - + Parameterized. - -Typical uses: - - To change the "User-Agent:" header so web servers can't tell your browser - type. Who's business is it anyway? - -Possible values: - - Any user defined string. - -Example usage: - - {+hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)}} - .msn.com - - + +Parameter: + + Keyword: "block", or any user defined value. + Notes: - - Warning! This breaks many web sites that depend on this in order to - determine how the target browser will respond to various requests. Use with - caution. - -------------------------------------------------------------------------------- -8.5.11. +handle-as-image + 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. -Type: - - Boolean. - -Typical uses: - - To define what Privoxy should treat automatically as an image, and is an - important ingredient of how ads are handled. - -Possible values: - - N/A - Example usage: - - {+handle-as-image} - /.*\.(gif|jpg|jpeg|png|bmp|ico) - - -Notes: - - This only has meaning if the URL (or pattern) also is "+block"ed, in which - case a user definable image can be sent rather than a HTML page. This is - integral to the whole concept of ad blocking: the URL must match both a - "+block" rule, and "+handle-as-image". (See "+set-image-blocker" below for - control over what will actually be displayed by the browser.) - - There is little reason to change the default definition for this action. - + + +hide-from-header{block} + + + or + + +hide-from-header{spam-me-senseless@sittingduck.example.com} + + ------------------------------------------------------------------------------- -8.5.12. +set-image-blocker +8.5.12. hide-referrer + +Typical use: + + Conceal which link you followed to get to a particular site + +Effect: + + Deletes the "Referer:" (sic) HTTP header from the client request, or + replaces it with a forged one. Type: - + Parameterized. - -Typical uses: - - Decide what to do with URLs that end up tagged with both "+block" and - "+handle-as-image", e.g an advertisement. - -Possible values: - - There are four available options: "-set-image-blocker" will send a HTML - "blocked" page, usually resulting in a "broken image" icon. - "+set-image-blocker{blank}" will send a 1x1 transparent GIF image. - "+set-image-blocker{pattern}" will send a checkerboard type pattern (the - default). And finally, "+set-image-blocker{http://xyz.com}" will send a - HTTP temporary redirect to the specified image. This has the advantage of - the icon being being cached by the browser, which will speed up the - display. - + +Parameter: + + + "block" to delete the header completely. + + + "forge" to pretend to be coming from the homepage of the server we are + talking to. + + + Any other string to set a user defined referrer. + +Notes: + + "forge" is the preferred option here, since some servers will not send + images back otherwise, in an attempt to prevent their valuable content from + being embedded elsewhere (and hence, without being surrounded by their + banners). + + hide-referer is an alternate spelling of hide-referrer and the two can be + can be freely substituted with each other. ("referrer" is the correct + English spelling, however the HTTP specification has a bug - it requires it + to be spelled as "referer".) + Example usage: - - {+set-image-blocker{blank}} - .example.com - - + + +hide-referrer{forge} + + + or + + +hide-referrer{http://www.yahoo.com/} + + +------------------------------------------------------------------------------- + +8.5.13. hide-user-agent + +Typical use: + + Conceal your type of browser and client operating system + +Effect: + + Replaces the value of the "User-Agent:" HTTP header in client requests with + the specified value. + +Type: + + Parameterized. + +Parameter: + + Any user-defined string. + Notes: - - If you want invisible ads, they need to meet criteria as matching both - images and blocked actions. And then, "image-blocker" should be set to - "blank" for invisibility. Note you cannot treat HTML pages as images in - most cases. For instance, frames require an HTML page to display. So a - frame that is an ad, typically cannot be treated as an image. Forcing an - "image" in this situation just will not work reliably. - + + +-----------------------------------------------------------------+ + | Warning | + |-----------------------------------------------------------------| + |This breaks many web sites that depend on looking at this header | + |in order to customize their content for different browsers | + |(which, by the way, is NOT a smart way to do that!). | + +-----------------------------------------------------------------+ + + Using this action in multi-user setups or wherever different types of + browsers will access the same Privoxy is not recommended. In single-user, + single-browser setups, you might use it to delete your OS version + information from the headers, because it is an invitation to exploit known + bugs for your OS. It is also occasionally useful to forge this in order to + access sites that won't let you in otherwise (though there may be a good + reason in some cases). Example of this: some MSN sites will not let Mozilla + enter, yet forging to a Netscape 6.1 user-agent works just fine. (Must be + just a silly MS goof, I'm sure :-). + + This action is scheduled for improvement. + +Example usage: + + +hide-user-agent{Netscape 6.1 (X11; I; Linux 2.4.18 i686)} + + ------------------------------------------------------------------------------- -8.5.13. +limit-connect +8.5.14. kill-popups + +Typical use: + + Eliminate those annoying pop-up windows (deprecated) + +Effect: + + While loading the document, replace JavaScript code that opens pop-up + windows with (syntactically neutral) dummy code on the fly. Type: - + + Boolean. + +Parameter: + + N/A + +Notes: + + This action is basically a built-in, hardwired special-purpose filter + action, but there are important differences: For kill-popups, the document + need not be buffered, so it can be incrementally rendered while + downloading. But kill-popups doesn't catch as many pop-ups as filter + {all-popups} does and is not as smart as filter{unsolicited-popups} is. + + Think of it as a fast and efficient replacement for a filter that you can + use if you don't want any filtering at all. Note that it doesn't make sense + to combine it with any filter action, since as soon as one filter applies, + the whole document needs to be buffered anyway, which destroys the + advantage of the kill-popups action over its filter equivalent. + + Killing all pop-ups unconditionally is problematic. Many shops and banks + rely on pop-ups to display forms, shopping carts etc, and the filter + {unsolicited-popups} does a fairly good job of catching only the unwanted + ones. + + If the only kind of pop-ups that you want to kill are exit consoles (those + really nasty windows that appear when you close an other one), you might + want to use filter{js-annoyances} instead. + +Example usage: + + +kill-popups + + +------------------------------------------------------------------------------- + +8.5.15. limit-connect + +Typical use: + + Prevent abuse of Privoxy as a TCP proxy relay + +Effect: + + Specifies to which ports HTTP CONNECT requests are allowable. + +Type: + Parameterized. - -Typical uses: - - By default, Privoxy only allows HTTP CONNECT requests to port 443 (the - standard, secure HTTPS port). Use "+limit-connect" to disable this - altogether, or to allow more ports. - -Possible values: - - Any valid port number, or port number range. - -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-} # - Port less than 3, 7, 20 to 100 and above 500 are OK. - - + +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 + ("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 proxy. This can be a big + connections to the client and to the remote server. This can be a big security hole, since CONNECT-enabled proxies can be abused as TCP relays very easily. - - If you want to allow CONNECT for more ports than this, or want to forbid - CONNECT altogether, you can specify a comma separated list of ports and - port ranges (the latter using dashes, with the minimum defaulting to 0 and - max to 65K). - + If you don't know what any of this means, there probably is no reason to - change this one. - + change this one, since the default is already very restrictive. + +Example usages: + + +limit-connect{443} # This is the default and need not be specified. + +limit-connect{80,443} # Ports 80 and 443 are OK. + +limit-connect{-3, 7, 20-100, 500-} # Ports less than 3, 7, 20 to 100 and above 500 are OK. + +limit-connect{-} # All ports are OK (gaping security hole!) + + ------------------------------------------------------------------------------- -8.5.14. +prevent-compression +8.5.16. prevent-compression + +Typical use: + + Ensure that servers send the content uncompressed, so it can be passed + through filters + +Effect: + + Adds a header to the request that asks for uncompressed transfer. Type: - + Boolean. - -Typical uses: - - Prevent the specified websites from compressing HTTP data. - -Possible values: - + +Parameter: + N/A - -Example usage: - - {+prevent-compression} - .example.com - - + Notes: - - Some websites do this, which can be a problem for Privoxy, since "+filter", - "+kill-popups" and "+gif-deanimate" will not work on compressed data. This - will slow down connections to those websites, though. Default typically is - to turn "prevent-compression" on. - + + More and more websites send their content compressed by default, which is + generally a good idea and saves bandwidth. But for the filter, + deanimate-gifs and kill-popups actions to work, Privoxy needs access to the + uncompressed data. Unfortunately, Privoxy can't yet(!) uncompress, filter, + and re-compress the content on the fly. So if you want to ensure that all + websites, including those that normally compress, can be filtered, you need + to use this action. + + This will slow down transfers from those websites, though. If you use any + of the above-mentioned actions, you will typically want to use + prevent-compression in conjunction with them. + + Note that some (rare) ill-configured sites don't handle requests for + uncompressed documents correctly (they send an empty document body). If you + use prevent-compression per default, you'll have to add exceptions for + those sites. See the example for how to do that. + +Example usage (sections): + + # Set default: + # + {+prevent-compression} + / # Match all sites + + # Make exceptions for ill sites: + # + {-prevent-compression} + www.debianhelp.org + www.pclinuxonline.com + + ------------------------------------------------------------------------------- -8.5.15. +session-cookies-only +8.5.17. send-vanilla-wafer + +Typical use: + + Feed log analysis scripts with useless data. + +Effect: + + Sends a cookie with each request stating that you do not accept any + copyright on cookies sent to you, and asking the site operator not to track + you. Type: - + Boolean. - -Typical uses: - - Allow cookies for the current browser session only. - -Possible values: - + +Parameter: + N/A - -Example usage (disabling): - - {-session-cookies-only} - .example.com - - + Notes: - - If websites set cookies, "+session-cookies-only" will make sure they are - erased when you exit and restart your web browser. 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. - - "+prevent-*-cookies" actions should be turned off as well (see below), for - "+session-cookies-only" to work. Or, else no cookies will get through at - all. For, "persistent" cookies that survive across browser sessions, see - below as well. - + + 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 + + ------------------------------------------------------------------------------- -8.5.16. +prevent-reading-cookies +8.5.18. send-wafer + +Typical use: + + Send custom cookies or feed log analysis scripts with even more useless + data. + +Effect: + + Sends a custom, user-defined cookie with each request. Type: - - Boolean. - -Typical uses: - - Explicitly prevent the web server from reading any cookies on your system. - -Possible values: - - N/A - -Example usage: - - {+prevent-reading-cookies} - .example.com - - + + Multi-value. + +Parameter: + + A string of the form "name=value". + Notes: - - Often used in conjunction with "+prevent-setting-cookies" to disable - cookies completely. Note that "+session-cookies-only" requires these to - both be disabled (or else it never gets any cookies to cache). - - For "persistent" cookies to work (i.e. they survive across browser sessions - and reboots), all three cookie settings should be "off" for the specified - sites. - + + 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 + + ------------------------------------------------------------------------------- -8.5.17. +prevent-setting-cookies +8.5.19. session-cookies-only + +Typical use: + + Allow only temporary "session" cookies (for the current browser session + only). + +Effect: + + Deletes the "expires" field from "Set-Cookie:" server headers. Most + browsers will not store such cookies permanently and forget them in between + sessions. Type: - + Boolean. - -Typical uses: - - Explicitly block the web server from storing cookies on your system. - -Possible values: - + +Parameter: + N/A - -Example usage: - - {+prevent-setting-cookies} - .example.com - - + Notes: - - Often used in conjunction with "+prevent-reading-cookies" to disable - cookies completely (see above). - + + 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 + + ------------------------------------------------------------------------------- -8.5.18. +kill-popups +8.5.20. set-image-blocker + +Typical use: + + Choose the replacement for blocked images + +Effect: + + This action alone doesn't do anything noticeable. If both block and + handle-as-image also apply, i.e. if the request is to be blocked as an + image, then the parameter of this action decides what will be sent as a + replacement. Type: - - Boolean. - -Typical uses: - - Stop those annoying JavaScript pop-up windows! - -Possible values: - - N/A - -Example usage: - - {+kill-popups} - .example.com - - + + Parameterized. + +Parameter: + + + "pattern" to send a built-in checkerboard pattern image. The image is + visually decent, scales very well, and makes it obvious where banners + were busted. + + + "blank" to send a built-in transparent image. This makes banners + disappear completely, but makes it hard to detect where Privoxy has + blocked images on a given page and complicates troubleshooting if + Privoxy has blocked innocent images, like navigation icons. + + + "target-url" to send a redirect to target-url. You can redirect to any + image anywhere, even in your local filesystem (via "file:///" URL). + + A good application of redirects is to use special Privoxy-built-in + URLs, which send the built-in images, as target-url. This has the same + visual effect as specifying "blank" or "pattern" in the first place, + but enables your browser to cache the replacement image, instead of + requesting it over and over again. + Notes: - - "+kill-popups" uses a built in filter to disable pop-ups that use the - window.open() function, etc. This is one of the first actions processed by - Privoxy as it contacts the remote web server. This action is not always - 100% reliable, and is supplemented by "+filter{popups}". - + + The URLs for the built-in images are "http://config.privoxy.org/ + send-banner?type=type", where type is either "blank" or "pattern". + + There is a third (advanced) type, called "auto". It is NOT to be used in + set-image-blocker, but meant for use from filters. Auto will select the + type of image that would have applied to the referring page, had it been an + image. + +Example usage: + + Built-in pattern: + + +set-image-blocker{pattern} + + + Redirect to the BSD devil: + + +set-image-blocker{http://www.freebsd.org/gifs/dae_up3.gif} + + + Redirect to the built-in pattern for better caching: + + +set-image-blocker{http://config.privoxy.org/send-banner?type=pattern} + + ------------------------------------------------------------------------------- -8.5.19. +send-vanilla-wafer +8.5.21. Summary + +Note that many of these actions have the potential to cause a page to +misbehave, possibly even not to display at all. There are many ways a site +designer may choose to design his site, and what HTTP header content, and other +criteria, he may depend on. There is no way to have hard and fast rules for all +sites. See the Appendix for a brief example on troubleshooting actions. + +------------------------------------------------------------------------------- + +8.6. Aliases + +Custom "actions", known to Privoxy as "aliases", can be defined by combining +other actions. These can in turn be invoked just like the built-in actions. +Currently, an alias name can contain any character except space, tab, "=", "{" +and "}", but we strongly recommend that you only use "a" to "z", "0" to "9", +"+", and "-". Alias names are not case sensitive, and are not required to start +with a "+" or "-" sign, since they are merely textually expanded. + +Aliases can be used throughout the actions file, but they must be defined in a +special section at the top of the file! And there can only be one such section +per actions file. Each actions file may have its own alias section, and the +aliases defined in it are only visible within that file. + +There are two main reasons to use aliases: One is to save typing for frequently +used combinations of actions, the other one is a gain in flexibility: If you +decide once how you want to handle shops by defining an alias called "shop", +you can later change your policy on shops in one place, and your changes will +take effect everywhere in the actions file where the "shop" alias is used. +Calling aliases by their purpose also makes your actions files more readable. + +Currently, there is one big drawback to using aliases, though: Privoxy's +built-in web-based action file editor honors aliases when reading the actions +files, but it expands them before writing. So the effects of your aliases are +of course preserved, but the aliases themselves are lost when you edit sections +that use aliases with it. This is likely to change in future versions of +Privoxy. + +Now let's define some aliases... + + # Useful custom aliases we can use later. + # + # Note the (required!) section header line and that this section + # must be at the top of the actions file! + # + {{alias}} + + # These aliases just save typing later: + # (Note that some already use other aliases!) + # + +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies + -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies + block-as-image = +block +handle-as-image + mercy-for-cookies = -crunch-all-cookies -session-cookies-only -filter{content-cookies} + + # These aliases define combinations of actions + # that are useful for certain types of sites: + # + fragile = -block -filter -crunch-all-cookies -fast-redirects -hide-referrer -kill-popups + shop = -crunch-all-cookies -filter{all-popups} -kill-popups + + # Short names for other aliases, for really lazy people ;-) + # + c0 = +crunch-all-cookies + c1 = -crunch-all-cookies + + +...and put them to use. These sections would appear in the lower part of an +actions file and define exceptions to the default actions (as specified further +up for the "/" pattern): + + # These sites are either very complex or very keen on + # user data and require minimal interference to work: + # + {fragile} + .office.microsoft.com + .windowsupdate.microsoft.com + .nytimes.com + + # Shopping sites: + # Allow cookies (for setting and retrieving your customer data) + # + {shop} + .quietpc.com + .worldpay.com # for quietpc.com + .scan.co.uk + + # These shops require pop-ups: + # + {shop -kill-popups -filter{all-popups}} + .dabs.com + .overclockers.co.uk + + +Aliases like "shop" and "fragile" are often used for "problem" sites that +require some actions to be disabled in order to function properly. + +------------------------------------------------------------------------------- + +8.7. Actions Files Tutorial + +The above chapters have shown which actions files there are and how they are +organized, how actions are specified and applied to URLs, how patterns work, +and how to define and use aliases. Now, let's look at an example default.action +and user.action file and see how all these pieces come together: + +------------------------------------------------------------------------------- + +8.7.1. default.action + +Every config file should start with a short comment stating its purpose: + +# Sample default.action file + + +Then, since this is the default.action file, the first section is a special +section for internal use that you needn't change or worry about: + +########################################################################## +# Settings -- Don't change! For internal Privoxy use ONLY. +########################################################################## + +{{settings}} +for-privoxy-version=3.0 + + +After that comes the (optional) alias section. We'll use the example section +from the above chapter on aliases, that also explains why and how aliases are +used: + +########################################################################## +# Aliases +########################################################################## +{{alias}} + + # These aliases just save typing later: + # (Note that some already use other aliases!) + # + +crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies + -crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies + block-as-image = +block +handle-as-image + mercy-for-cookies = -crunch-all-cookies -session-cookies-only -filter{content-cookies} + + # These aliases define combinations of actions + # that are useful for certain types of sites: + # + fragile = -block -filter -crunch-all-cookies -fast-redirects -hide-referrer -kill-popups + shop = -crunch-all-cookies -filter{all-popups} -kill-popups + + +Now come the regular sections, i.e. sets of actions, accompanied by URL +patterns to which they apply. Remember all actions are disabled when matching +starts, so we have to explicitly enable the ones we want. + +The first regular section is probably the most important. It has only one +pattern, "/", but this pattern matches all URLs. Therefore, the set of actions +used in this "default" section will be applied to all requests as a start. It +can be partly or wholly overridden by later matches further down this file, or +in user.action, but it will still be largely responsible for your overall +browsing experience. + +Again, at the start of matching, all actions are disabled, so there is no real +need to disable any actions here, but we will do that nonetheless, to have a +complete listing for your reference. (Remember: a "+" preceding the action name +enables the action, a "-" disables!). Also note how this long line has been +made more readable by splitting it into multiple lines with line continuation. + +########################################################################## +# "Defaults" section: +########################################################################## + { \ + -add-header \ + -block \ + -crunch-incoming-cookies \ + -crunch-outgoing-cookies \ + +deanimate-gifs \ + -downgrade-http-version \ + +fast-redirects \ + +filter{js-annoyances} \ + -filter{js-events} \ + +filter{html-annoyances} \ + -filter{content-cookies} \ + +filter{refresh-tags} \ + +filter{unsolicited-popups} \ + -filter{all-popups} \ + +filter{img-reorder} \ + +filter{banners-by-size} \ + -filter{banners-by-link} \ + +filter{webbugs} \ + -filter{tiny-textforms} \ + +filter{jumping-windows} \ + -filter{frameset-borders} \ + -filter{demoronizer} \ + -filter{shockwave-flash} \ + -filter{quicktime-kioskmode} \ + -filter{fun} \ + -filter{crude-parental} \ + +filter{ie-exploits} \ + -handle-as-image \ + +hide-forwarded-for-headers \ + +hide-from-header{block} \ + +hide-referrer{forge} \ + -hide-user-agent \ + -kill-popups \ + -limit-connect \ + +prevent-compression \ + -send-vanilla-wafer \ + -send-wafer \ + +session-cookies-only \ + +set-image-blocker{pattern} \ + } + / # forward slash will match *all* potential URL patterns. + + +The default behavior is now set. Note that some actions, like not hiding the +user agent, are part of a "general policy" that applies universally and won't +get any exceptions defined later. Other choices, like not blocking (which is +understandably the default!) need exceptions, i.e. we need to specify +explicitly what we want to block in later sections. + +The first of our specialized sections is concerned with "fragile" sites, i.e. +sites that require minimum interference, because they are either very complex +or very keen on tracking you (and have mechanisms in place that make them +unusable for people who avoid being tracked). We will simply use our +pre-defined fragile alias instead of stating the list of actions explicitly: + +########################################################################## +# Exceptions for sites that'll break under the default action set: +########################################################################## + +# "Fragile" Use a minimum set of actions for these sites (see alias above): +# +{ fragile } +.office.microsoft.com # surprise, surprise! +.windowsupdate.microsoft.com + + +Shopping sites are not as fragile, but they typically require cookies to log +in, and pop-up windows for shopping carts or item details. Again, we'll use a +pre-defined alias: + +# Shopping sites: +# +{ shop } +.quietpc.com +.worldpay.com # for quietpc.com +.jungle.com +.scan.co.uk + + +The fast-redirects action, which we enabled per default above, breaks some +sites. So disable it for popular sites where we know it misbehaves: + +{ -fast-redirects } +login.yahoo.com +edit.*.yahoo.com +.google.com +.altavista.com/.*(like|url|link):http +.altavista.com/trans.*urltext=http +.nytimes.com + + +It is important that Privoxy knows which URLs belong to images, so that if they +are to be blocked, a substitute image can be sent, rather than an HTML page. +Contacting the remote site to find out is not an option, since it would destroy +the loading time advantage of banner blocking, and it would feed the +advertisers (in terms of money and information). We can mark any URL as an +image with the handle-as-image action, and marking all URLs that end in a known +image file extension is a good start: + +########################################################################## +# Images: +########################################################################## + +# Define which file types will be treated as images, in case they get +# blocked further down this file: +# +{ +handle-as-image } +/.*\.(gif|jpe?g|png|bmp|ico)$ + + +And then there are known banner sources. They often use scripts to generate the +banners, so it won't be visible from the URL that the request is for an image. +Hence we block them and mark them as images in one go, with the help of our +block-as-image alias defined above. (We could of course just as well use +block ++handle-as-image here.) Remember that the type of the replacement image is +chosen by the set-image-blocker action. Since all URLs have matched the default +section with its +set-image-blocker{pattern} action before, it still applies +and needn't be repeated: + +# Known ad generators: +# +{ block-as-image } +ar.atwola.com +.ad.doubleclick.net +.ad.*.doubleclick.net +.a.yimg.com/(?:(?!/i/).)*$ +.a[0-9].yimg.com/(?:(?!/i/).)*$ +bs*.gsanet.com +bs*.einets.com +.qkimg.net + + +One of the most important jobs of Privoxy is to block banners. A huge bunch of +them are already "blocked" by the filter{banners-by-size} action, which we +enabled above, and which deletes the references to banner images from the pages +while they are loaded, so the browser doesn't request them anymore, and hence +they don't need to be blocked here. But this naturally doesn't catch all +banners, and some people choose not to use filters, so we need a comprehensive +list of patterns for banner URLs here, and apply the block action to them. + +First comes a bunch of generic patterns, which do most of the work, by matching +typical domain and path name components of banners. Then comes a list of +individual patterns for specific sites, which is omitted here to keep the +example short: + +########################################################################## +# Block these fine banners: +########################################################################## +{ +block } + +# Generic patterns: +# +ad*. +.*ads. +banner?. +count*. +/.*count(er)?\.(pl|cgi|exe|dll|asp|php[34]?) +/(?:.*/)?(publicite|werbung|rekla(ma|me|am)|annonse|maino(kset|nta|s)?)/ + +# Site-specific patterns (abbreviated): +# +.hitbox.com + + +You wouldn't believe how many advertisers actually call their banner servers +ads.company.com, or call the directory in which the banners are stored simply +"banners". So the above generic patterns are surprisingly effective. + +But being very generic, they necessarily also catch URLs that we don't want to +block. The pattern .*ads. e.g. catches "nasty-ads.nasty-corp.com" as intended, +but also "downloads.sourcefroge.net" or "adsl.some-provider.net." So here come +some well-known exceptions to the +block section above. + +Note that these are exceptions to exceptions from the default! Consider the URL +"downloads.sourcefroge.net": Initially, all actions are deactivated, so it +wouldn't get blocked. Then comes the defaults section, which matches the URL, +but just deactivates the block action once again. Then it matches .*ads., an +exception to the general non-blocking policy, and suddenly +block applies. And +now, it'll match .*loads., where -block applies, so (unless it matches again +further down) it ends up with no block action applying. + +########################################################################## +# Save some innocent victims of the above generic block patterns: +########################################################################## + +# By domain: +# +{ -block } +adv[io]*. # (for advogato.org and advice.*) +adsl. # (has nothing to do with ads) +ad[ud]*. # (adult.* and add.*) +.edu # (universities don't host banners (yet!)) +.*loads. # (downloads, uploads etc) + +# By path: +# +/.*loads/ + +# Site-specific: +# +www.globalintersec.com/adv # (adv = advanced) +www.ugu.com/sui/ugu/adv + + +Filtering source code can have nasty side effects, so make an exception for our +friends at sourceforge.net, and all paths with "cvs" in them. Note that -filter +disables all filters in one fell swoop! + +# Don't filter code! +# +{ -filter } +/.*cvs +.sourceforge.net + + +The actual default.action is of course more comprehensive, but we hope this +example made clear how it works. + +------------------------------------------------------------------------------- + +8.7.2. user.action + +So far we are painting with a broad brush by setting general policies, which +would be a reasonable starting point for many people. Now, you might want to be +more specific and have customized rules that are more suitable to your personal +habits and preferences. These would be for narrowly defined situations like +your ISP or your bank, and should be placed in user.action, which is parsed +after all other actions files and hence has the last word, over-riding any +previously defined actions. user.action is also a safe place for your personal +settings, since default.action is actively maintained by the Privoxy developers +and you'll probably want to install updated versions from time to time. + +So let's look at a few examples of things that one might typically do in +user.action: + +# My user.action file. + + +As aliases are local to the actions file that they are defined in, you can't +use the ones from default.action, unless you repeat them here: + +# Aliases are local to the file they are defined in. +# (Re-)define aliases for this file: +# +{{alias}} +# +# These aliases just save typing later, and the alias names should +# be self explanatory. +# ++crunch-all-cookies = +crunch-incoming-cookies +crunch-outgoing-cookies +-crunch-all-cookies = -crunch-incoming-cookies -crunch-outgoing-cookies + allow-all-cookies = -crunch-all-cookies -session-cookies-only + allow-popups = -filter{all-popups} -kill-popups ++block-as-image = +block +handle-as-image +-block-as-image = -block + +# These aliases define combinations of actions that are useful for +# certain types of sites: +# +fragile = -block -crunch-all-cookies -filter -fast-redirects -hide-referrer -kill-popups +shop = -crunch-all-cookies allow-popups + +# Allow ads for selected useful free sites: +# +allow-ads = -block -filter{banners-by-size} -filter{banners-by-link} + + +Say you have accounts on some sites that you visit regularly, and you don't +want to have to log in manually each time. So you'd like to allow persistent +cookies for these sites. The allow-all-cookies alias defined above does exactly +that, i.e. it disables crunching of cookies in any direction, and the +processing of cookies to make them only temporary. + +{ allow-all-cookies } +sourceforge.net +sunsolve.sun.com +.slashdot.org +.yahoo.com +.msdn.microsoft.com +.redhat.com + + +Your bank is allergic to some filter, but you don't know which, so you disable +them all: + +{ -filter } +.your-home-banking-site.com + + +Some file types you may not want to filter for various reasons: + +# Technical documentation is likely to contain strings that might +# erroneously get altered by the JavaScript-oriented filters: +# +.tldp.org +/(.*/)?selfhtml/ + +# And this stupid host sends streaming video with a wrong MIME type, +# so that Privoxy thinks it is getting HTML and starts filtering: +# +stupid-server.example.com/ + + +Example of a simple block action. Say you've seen an ad on your favourite page +on example.com that you want to get rid of. You have right-clicked the image, +selected "copy image location" and pasted the URL below while removing the +leading http://, into a { +block } section. Note that { +handle-as-image } need +not be specified, since all URLs ending in .gif will be tagged as images by the +general rules as set in default.action anyway: + +{ +block } +www.example.com/nasty-ads/sponsor.gif +another.popular.site.net/more/junk/here/ + + +The URLs of dynamically generated banners, especially from large banner farms, +often don't use the well-known image file name extensions, which makes it +impossible for Privoxy to guess the file type just by looking at the URL. You +can use the +block-as-image alias defined above for these cases. Note that +objects which match this rule but then turn out NOT to be an image are +typically rendered as a "broken image" icon by the browser. Use cautiously. + +{ +block-as-image } +.doubleclick.net +/Realmedia/ads/ +ar.atwola.com/ + + +Now you noticed that the default configuration breaks Forbes Magazine, but you +were too lazy to find out which action is the culprit, and you were again too +lazy to give feedback, so you just used the fragile alias on the site, and -- +whoa! -- it worked. The fragile aliases disables those actions that are most +likely to break a site. Also, good for testing purposes to see if it is Privoxy +that is causing the problem or not. + +{ fragile } +.forbes.com + + +You like the "fun" text replacements in default.filter, but it is disabled in +the distributed actions file. (My colleagues on the team just don't have a +sense of humour, that's why! ;-). So you'd like to turn it on in your private, +update-safe config, once and for all: + +{ +filter{fun} } +/ # For ALL sites! + + +Note that the above is not really a good idea: There are exceptions to the +filters in default.action for things that really shouldn't be filtered, like +code on CVS->Web interfaces. Since user.action has the last word, these +exceptions won't be valid for the "fun" filtering specified here. + +You might also worry about how your favourite free websites are funded, and +find that they rely on displaying banner advertisements to survive. So you +might want to specifically allow banners for those sites that you feel provide +value to you: + +{ allow-ads } +.sourceforge.net +.slashdot.org +.osdn.net + + +Note that allow-ads has been aliased to -block, -filter{banners-by-size}, and - +filter{banners-by-link} above. + +user.action is generally the best place to define exceptions and additions to +the default policies of default.action. Some actions are safe to have their +default policies set here though. So let's set a default policy to have a +"blank" image as opposed to the checkerboard pattern for ALL sites. "/" of +course matches all URL paths and patterns: -Type: - - Boolean. - -Typical uses: - - Sends a cookie for every site stating that you do not accept any copyright - on cookies sent to you, and asking them not to track you. - -Possible values: - - N/A - -Example usage: - - {+send-vanilla-wafer} - .example.com - - -Notes: - - This action only applies if you are using a jarfile for saving cookies. Of - course, this is a (relatively) unique header and could conceivably be used - to track you. - -------------------------------------------------------------------------------- +{ +set-image-blocker{blank} } +/ # ALL sites -8.5.20. +send-wafer -Type: - - Multi-value. - -Typical uses: - - This allows you to send an arbitrary, user definable cookie. - -Possible values: - - User specified cookie name and corresponding value. - -Example usage: - - {+send-wafer{name=value}} - .example.com - - -Notes: - - This can be specified multiple times in order to add as many cookies as you - like. - ------------------------------------------------------------------------------- -8.5.21. Summary +9. The Filter File -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. +All text substitutions that can be invoked through the filter action must first +be defined in the filter file, which is typically called default.filter and +which can be selected through the filterfile config option. + +Typical reasons for doing such substitutions are to eliminate common annoyances +in HTML and JavaScript, such as pop-up windows, exit consoles, crippled windows +without navigation tools, the infamous tag etc, to suppress images with +certain width and height attributes (standard banner sizes or web-bugs), or +just to have fun. The possibilities are endless. + +Filtering works on any text-based document type, including HTML, JavaScript, +CSS etc. (all text/* MIME types, except text/plain). Substitutions are made at +the source level, so if you want to "roll your own" filters, you should be +familiar with HTML syntax. + +Just like the actions files, the filter file is organized in sections, which +are called filters here. Each filter consists of a heading line, that starts +with the keyword FILTER:, followed by the filter's name, and a short (one line) +description of what it does. Below that line come the jobs, i.e. lines that +define the actual text substitutions. By convention, the name of a filter +should describe what the filter eliminates. The comment is used in the +web-based user interface. + +Once a filter called name has been defined in the filter file, it can be +invoked by using an action of the form +filter{name} in any actions file. + +A filter header line for a filter called "foo" could look like this: + +FILTER: foo Replace all "foo" with "bar" + + +Below that line, and up to the next header line, come the jobs that define what +text replacements the filter executes. They are specified in a syntax that +imitates Perl's s/// operator. If you are familiar with Perl, you will find +this to be quite intuitive, and may want to look at the PCRS man page for the +subtle differences to Perl behaviour. Most notably, the non-standard option +letter U is supported, which turns the default to ungreedy matching. + +If you are new to regular expressions, you might want to take a look at the +Appendix on regular expressions, and see the Perl manual for the s/// +operator's syntax and Perl-style regular expressions in general. The below +examples might also help to get you started. ------------------------------------------------------------------------------- -8.5.22. Sample Actions Files +9.1. Filter File Tutorial -Remember that the meaning of any of the above references is reversed by -preceding the action with a "-", in place of the "+". Also, that some actions -are turned on in the default section of the actions file, and require little to -no additional configuration. These are just "on". +Now, let's complete our "foo" filter. We have already defined the heading, but +the jobs are still missing. Since all it does is to replace "foo" with "bar", +there is only one (trivial) job needed: -But, other actions that are turned on in the default section do typically -require exceptions to be listed in the latter sections of one of our actions -file. For instance, by default no URLs are "blocked" (i.e. in the default -definitions of default.action). We need exceptions to this in order to enable -ad blocking in the lower sections. But we need to be very selective about what -we do block. Thus, the default is "off" for blocking. +s/foo/bar/ -Below is a liberally commented sample default.action file to demonstrate how -all the pieces come together. And to show how exceptions to the default -policies can be handled. This is followed by a brief user.action with similar -examples. -# Sample default.action file +But wait! Didn't the comment say that all occurrences of "foo" should be +replaced? Our current job will only take care of the first "foo" on each page. +For global substitution, we'll need to add the g option: -# Settings -- Don't change! For internal Privoxy use ONLY. -{{settings}} -for-privoxy-version=3.0 +s/foo/bar/g -########################################################################## -# Aliases must be defined *before* they are used. These are -# easier to remember, and can combine several actions into one. Once -# defined they can be used just like any built-in action -- but within -# this file only! Aliases do not require a + or - sign. -########################################################################## +Our complete filter now looks like this: -# Some useful aliases. -# Alias to turn off cookie handling, ie allow all cookies unmolested. - -prevent-cookies = -prevent-setting-cookies -prevent-reading-cookies \ - -session-cookies-only +FILTER: foo Replace all "foo" with "bar" +s/foo/bar/g -# Alias to both block and treat as if an image for ad blocking -# purposes. - +imageblock = +block +handle-as-image -# Fragile sites should have the minimum changes: - fragile = -block -deanimate-gifs -fast-redirects -filter -hide-referer \ - -prevent-cookies -kill-popups +Let's look at some real filters for more interesting examples. Here you see a +filter that protects against some common annoyances that arise from JavaScript +abuse. Let's look at its jobs one after the other: -# Shops should be allowed to set persistent cookies - shop = -filter -prevent-cookies -session-cookies-only +FILTER: js-annoyances Get rid of particularly annoying JavaScript abuse +# Get rid of JavaScript referrer tracking. Test page: http://www.randomoddness.com/untitled.htm +# +s|()|$1"Not Your Business!"$2|Usg + + +Following the header line and a comment, you see the job. Note that it uses | +as the delimiter instead of /, because the pattern contains a forward slash, +which would otherwise have to be escaped by a backslash (\). + +Now, let's examine the pattern: it starts with the text tag. + +That's more than we want, but the pattern continues: document\.referrer matches +only the exact string "document.referrer". The dot needed to be escaped, i.e. +preceded by a backslash, to take away its special meaning as a joker, and make +it just a regular dot. So far, the meaning is: Match from the start of the +first . You already know what .* means, so the whole +pattern translates to: Match from the start of the first " tag. Furthermore, the s +option says that the match may span multiple lines in the page, and the g +option again means that the substitution is global. + +So, to summarize, the pattern means: Match all scripts that contain the text +"document.referrer". Remember the parts of the script from (and including) the +start tag up to (and excluding) the string "document.referrer" as $1, and the +part following that string, up to and including the closing tag, as $2. + +Now the pattern is deciphered, but wasn't this about substituting things? So +lets look at the substitute: $1"Not Your Business!"$2 is easy to read: The text +remembered as $1, followed by "Not Your Business!" (including the quotation +marks!), followed by the text remembered as $2. This produces an exact copy of +the original string, with the middle part (the "document.referrer") replaced by +"Not Your Business!". + +The whole job now reads: Replace "document.referrer" by "Not Your Business!" +wherever it appears inside a