1 output is user-manual Using catalogs: /etc/sgml/sgml-docbook-3.1.cat Using
2 stylesheet: /usr/share/sgml/docbook/utils-0.6/docbook-utils.dsl#html Working
3 on: /home/hal/junkbuster/current/doc/source/user-manual.sgml Junkbuster User Manual
5 By: Junkbuster Developers
7 The user manual gives the users
8 information on how to install and
9 configure Internet Junkbuster. Internet
10 Junkbuster is an application that
11 provides privacy and security to users
12 of the World Wide Web.
14 You can find the latest version of the
15 user manual at http://
16 ijbswa.sourceforge.net/user-manual/.
18 Feel free to send a note to the
20 ijbswa-developers@lists.sourceforge.net
23 -----------------------------------------------------------
28 Junkbuster Configuration
29 Quickstart to Using Junkbuster
30 Contact the Developers
37 Internet Junkbuster is a web proxy with advanced filtering capabilities for
38 protecting privacy, filtering web page content, managing cookies, controlling
39 access, and removing ads, banners, pop-ups and other obnoxious Internet Junk.
40 Junkbuster has a very flexible configuration and can be customized to suit
41 individual needs and tastes. Internet Junkbuster has application for both
42 stand-alone systems and multi-user networks.
44 This documentation is included with the current development version of Internet
45 Junkbuster and is incomplete at this point. The most up to date reference for
46 the time being is still the comments in the source files and in the individual
47 configuration files. Development of version 3.0 is currently underway, and
48 includes many significant changes and enhancements over earlier verions. The
49 target release date for stable v3.0 is December 2001.
51 Since this is a development version, some features are in the process of being
52 implemented. This documentation may be slightly out of sync as a result. And
53 there are bugs, though hopefully not many!
55 -------------------------------------------------------------------------------
59 In addition to Junkbuster's traditional features of ad and banner blocking and
60 cookie management, this is a list of new features currently under development:
62 * A browser based configuration utility (WIP at http://i.j.b).
64 * Modularized configuration that will allow for system wide settings, and
65 individual user settings. (not implemented yet)
67 * Blocking of annoying pop-up browser windows (previously available as a
70 * Support for HTTP/1.1 (partially implemented at this point).
72 * Support for Perl Compatible Regular Expressions in the configuration files,
73 and generally a more sophisticated configuration syntax over previous
76 * Web page content filtering.
80 In addition, the configuration is more versatile overall.
82 -------------------------------------------------------------------------------
86 Junkbuster is available as raw source code, or pre-compiled binaries. See the
87 Junkbuster Home Page for current release info. Junkbuster is also available via
88 CVS. This is the recommended approach at this time. But please be aware that
89 CVS is constantly changing, and it may break in mysterious ways.
91 -------------------------------------------------------------------------------
95 For gzipped tar archives, unpack the source:
97 tar zxvf ijb_source_2.9*
101 For retrieving the current CVS sources, you'll need the CVS package installed
102 first. To download CVS source:
104 cvs -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa login
105 cvs -z3 -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa co current
109 This will create a directory named current/, which will contain the source
112 Then, in either case, to build from source:
114 autoconf #recommended for CVS source
121 For Redhat and SuSE Linux RPM packages, see below.
123 -------------------------------------------------------------------------------
127 To build Redhat RPM packages, install source as above. Then:
129 autoconf #recommended for CVS source
134 This will create both binary and src RPMs in the usual places. Example:
136 /usr/src/redhat/RPMS/i686/junkbuster-2.9.8-1.i686.rpm
138 /usr/src/redhat/SRPMS/junkbuster-2.9.9-1.src.rpm
140 To install, of course:
142 rpm -Uvv /usr/src/redhat/RPMS/i686/junkbuster-2.9.9-1.i686.rpm
145 This will place the Junkbuster configuration files in /etc/junkbuster/, and log
146 files in /var/log/junkbuster/.
148 -------------------------------------------------------------------------------
152 To build SuSE RPM packages, install source as above. Then:
154 autoconf #recommended for CVS source
159 This will create both binary and src RPMs in the usual places. Example:
161 /usr/src/suse/RPMS/i686/junkbuster-2.9.9-1.i686.rpm
163 /usr/src/suse/SRPMS/junkbuster-2.9.9-1.src.rpm
165 To install, of course:
167 rpm -Uvv /usr/src/suse/RPMS/i686/junkbuster-2.9.9-1.i686.rpm
170 This will place the Junkbuster configuration files in /etc/junkbuster/, and log
171 files in /var/log/junkbuster/.
173 -------------------------------------------------------------------------------
177 The OS/2 version of Junkbuster requires the EMX runtime library to be
178 installed. The EMX runtime library is available on the hobbes OS/2 archive,
179 among many other locations: http://hobbes.nmsu.edu/cgi-bin/h-search?sh=1&button
180 =Search&key=emxrt.zip&stype=all&sort=type&dir=%2Fpub%2Fos2%2Fdev%2Femx%2Fv0.9d
182 Junkbuster is packaged in a WarpIN self- installing archive. The
183 self-installing program will be named depending on the release version,
184 something like: ijbos123.exe. In order to install it, simply run this
185 executable or double-click on its icon and follow the WarpIN installation
186 panels. A shadow of the Junkbuster executable will be placed in your startup
187 folder so it will start automatically whenever OS/2 starts.
189 The directory you choose to install Junkbuster into will contain all of the
192 If you would like to build binary images on OS/2 yourself, you will need a
193 working EMX/GCC environment, plus several Unix-like tools. The Hobbes OS/2
194 archive is a good place to start when building such an environment. A set of
195 Unix-like tools named gnupack is located here: http://hobbes.nmsu.edu/cgi-bin/
196 h-search?sh=1&key=gnupack&stype=all&sort=type&dir=%2Fpub%2Fos2%2Fapps
198 Once you have the source code unpacked as above, you can build the binaries
199 from the current/ directory:
206 -------------------------------------------------------------------------------
210 Click-click. (I need help on this. Not a clue here. Also for configuration
213 -------------------------------------------------------------------------------
217 Some quick notes on other Operating Systems.
219 For FreeBSD (and other *BSDs?), the build will need gmake instead of the
220 included make. gmake is available from http://www.gnu.org. The rest should be
221 the same as above for Linux/Unix.
223 -------------------------------------------------------------------------------
225 Junkbuster Configuration
227 For Unix, *BSD and Linux, all configuraton files are located in /etc/junkbuster
228 / by default. For MS Windows and OS/2, these are all in the same directory as
229 the Junkbuster executable. The name and number of configuration files has
230 changed from previous versions, and is subject to change as development
233 The installed defaults provide a reasonable starting point. For the time being,
234 there are only three default configuration files (this will change in time):
236 * The main configuration file is named config on Linux, Unix, BSD, and OS/2,
237 and junkbustr.txt on Windows. On Amiga, it is AmiTCP:db/junkbuster/config.
239 * The actionsfile file is used to define various "actions" relating to
240 images, banners, pop-ups, access restrictions, banners and cookies. There
241 is a CGI based editor for this file that can be accessed via http://i.j.b./
242 . This is the easiest method of configuring actions. (Still under active
245 * The re_filterfile file can be used to rewrite the raw page content,
246 including text as well as embedded HTML and JavaScript.
248 actionsfile and re_filterfile can use Perl style regular expressions for
249 maximum flexibility. All files use the "#" character to denote a comment. Such
250 lines are not processed by Junkbuster. After making any changes, restart
251 Junkbuster in order for the changes to take effect.
253 While under development, the configuration content is subject to change. The
254 below documentation may not be accurate by the time you read this. Also, what
255 constitutes a "default" setting, may change, so please check all your
256 configuration files on important issues.
258 -------------------------------------------------------------------------------
260 The Main Configuration File
262 Again, the main configuration file is named config on Linux/Unix/BSD and OS/2,
263 and junkbustr.txt on Windows. Configuration lines consist of an initial keyword
264 followed by a list of values, all separated by whitespace (any number of spaces
265 or tabs). For example:
267 blockfile blocklist.ini
270 Indicates that the blockfile is named "blocklist.ini".
272 A "#" indicates a comment. Any part of a line following a "#" is ignored,
273 except if the "#" is preceded by a "\".
275 Thus, by placing a "#" at the start of an existing configuration line, you can
276 make it a comment and it will be treated as if it weren't there. This is called
277 "commenting out" an option and can be useful to turn off features: If you
278 comment out the "logfile" line, junkbuster will not log to a file at all. Watch
279 for the "default:" section in each explanation to see what happens if the
280 option is left unset (or commented out).
282 Long lines can be continued on the next line by using a "\" as the very last
285 There are various aspects of Junkbuster behavior that can be tuned.
287 -------------------------------------------------------------------------------
289 Defining Other Configuration Files
291 Junkbuster can use a number of other files to tell it what ads to block, what
292 cookies to accept, etc. This section of the configuration file tells Junkbuster
293 where to find all those other files.
295 On Windows, Junkbuster looks for these files in the same directory as the
296 executable. On Unix and OS/2, Junkbuster looks for these files in the current
297 working directory. In either case, an absolute path name can be used to avoid
300 When development goes modular and multiuser, the blocker, filter, and per-user
301 config will be stored in subdirectories of "confdir". For now, only confdir/
302 templates is used for storing HTML templates for CGI results.
304 The location of the configuration files:
306 confdir /etc/junkbuster # No trailing /, please.
309 The directory where all logging (i.e. logfile and jarfile) takes place. No
310 trailing "/", please:
312 logdir /var/log/junkbuster
315 Note that all file specifications below are relative to the above two
318 The "actionsfile" contains patterns to specify the actions to apply to requests
319 for each site. Default: Cookies to and from all destinations are filtered.
320 Popups are disabled for all sites. All sites are filtered if re_filterfile
321 specified. No sites are blocked. An empty image is displayed for filtered ads
322 and other images (formerly "tinygif"). The syntax of this file is explained in
325 actionsfile actionsfile
328 The "re_filterfile" file contains content modification rules. These rules
329 permit powerful changes on the content of Web pages, e.g., you could disable
330 your favourite JavaScript annoyances, rewrite the actual content, or just have
331 some fun replacing "Microsoft" with "MicroSuck" wherever it appears on a Web
332 page. Default: No content modification, or whatever the developers are playing
335 re_filterfile re_filterfile
338 The logfile is where all logging and error messages are written. The logfile
339 can be useful for tracking down a problem with Junkbuster (e.g., it's not
340 blocking an ad you think it should block) but in most cases you probably will
343 Your logfile will grow indefinitely, and you will probably want to periodically
344 remove it. On Unix systems, you can do this with a cron job (see "man cron").
345 For Redhat, a logrotate script has been included.
347 On SuSE Linux systems, you can place a line like "/var/log/junkbuster.* +1024k
348 644 nobody.nogroup" in /etc/logfiles, with the effect that cron.daily will
349 automatically archive, gzip, and empty the log, when it exceeds 1M size.
351 Default: Log to the a file named logfile. Comment out to disable logging.
356 The "jarfile" defines where Junkbuster stores the cookies it intercepts. Note
357 that if you use a "jarfile", it may grow quite large. Default: Don't store
363 If you specify a "trustfile", Junkbuster will only allow access to sites that
364 are named in the trustfile. You can also mark sites as trusted referrers, with
365 the effect that access to untrusted sites will be granted, if a link from a
366 trusted referrer was used. The link target will then be added to the
367 "trustfile". This is a very restrictive feature that typical users most
368 propably want to leave disabled. Default: Disabled, don't use the trust
374 If you use the trust mechanism, it is a good idea to write up some online
375 documentation about your blocking policy and to specify the URL(s) here. They
376 will appear on the page that your users receive when they try to access
377 untrusted content. Use multiple times for multiple URLs. Default: Don't display
378 links on the "untrusted" info page.
380 trust-info-url http://www.your-site.com/why_we_block.html
381 trust-info-url http://www.your-site.com/what_we_allow.html
384 -------------------------------------------------------------------------------
386 Other Configuration Options
388 This part of the configuration file contains options that control how
391 "Admin-address" should be set to the email address of the proxy administrator.
392 It is used in many of the proxy-generated pages. Default: fill@me.in.please.
394 #admin-address fill@me.in.please
397 "Proxy-info-url" can be set to a URL that contains more info about this
398 Junkbuster installation, it's configuration and policies. It is used in many of
399 the proxy-generated pages and its use is highly recommended in multi-user
400 installations, since your users will want to know why certain content is
401 blocked or modified. Default: Don't show a link to online documentation.
403 proxy-info-url http://www.your-site.com/proxy.html
406 "Listen-address" specifies the address and port where Junkbuster will listen
407 for connections from your Web browser. The default is to listen on the
408 localhost port 8000, and this is suitable for most users. (In your web browser,
409 under proxy configuration, list the proxy server as "localhost" and the port as
412 If you already have another service running on port 8000, or if you want to
413 serve requests from other machines (e.g. on your local network) as well, you
414 will need to override the default. The syntax is "listen-address
415 [<ip-address>]:<port>". If you leave out the IP address, junkbuster will bind
416 to all interfaces (addresses) on your machine and may become reachable from the
417 Internet. In that case, consider using access control lists (acl's) (see
418 "aclfile" above), or a firewall.
420 For example, suppose you are running Junkbuster on a machine which has the
421 address 192.168.0.1 on your local private network (192.168.0.0) and has another
422 outside connection with a different address. You want it to serve requests from
425 listen-address 192.168.0.1:8000
428 If you want it to listen on all addresses (including the outside connection):
433 If you do this, consider using ACLs (see "aclfile" above). Note: you will need
434 to point your browser(s) to the address and port that you have configured here.
435 Default: localhost:8000 (127.0.0.1:8000).
437 The debug option sets the level of debugging information to log in the logfile
438 (and to the console in the Windows version). A debug level of 1 is informative
439 because it will show you each request as it happens. Higher levels of debug are
440 probably only of interest to developers.
442 debug 1 # GPC = show each GET/POST/CONNECT request
443 debug 2 # CONN = show each connection status
444 debug 4 # IO = show I/O status
445 debug 8 # HDR = show header parsing
446 debug 16 # LOG = log all data into the logfile
447 debug 32 # FRC = debug force feature
448 debug 64 # REF = debug regular expression filter
449 debug 128 # = debug fast redirects
450 debug 256 # = debug GIF deanimation
451 debug 512 # CLF = Common Log Format
452 debug 1024 # = debug kill popups
453 debug 4096 # INFO = Startup banner and warnings.
454 debug 8192 # ERROR = Non-fatal errors
457 It is highly recommended that you enable ERROR reporting (debug 8192), at least
458 until the next stable release.
460 The reporting of FATAL errors (i.e. ones which crash JunkBuster) is always on
461 and cannot be disabled.
463 If you want to use CLF (Common Log Format), you should set "debug 512" ONLY, do
464 not enable anything else.
466 Multiple "debug" directives, are OK - they're logical-OR'd together.
468 debug 15 # same as setting the first 4 listed above
475 debug 8192 # Errors - *we highly recommended enabling this*
478 Junkbuster normally uses "multi-threading", a software technique that permits
479 it to handle many different requests simultaneously. In some cases you may wish
480 to disable this -- particularly if you're trying to debug a problem. The
481 "single-threaded" option forces Junkbuster to handle requests sequentially.
482 Default: Multi-threaded mode.
487 "toggle" allows you to temporarily disable all Junkbuster's filtering. Just set
490 The Windows version of Junkbuster puts an icon in the system tray, which also
491 allows you to change this option. If you right-click on that icon (or select
492 the "Options" menu), one choice is "Enable". Clicking on enable toggles
493 Junkbuster on and off. This is useful if you want to temporarily disable
494 Junkbuster, e.g., to access a site that requires cookies which you normally
495 have blocked. This can also be toggled via a web browser at the Junkbuster
496 internal address of http://i.j.b./ on any platform.
498 "toggle 1" means Junkbuster runs normally, "toggle 0" means that Junkbuster
499 becomes a non-anonymizing non-blocking proxy. Default: 1 (on).
504 For content filtering, i.e. the "+filter" and "+deanimate-gif" actions, it is
505 neccessary that Junkbuster buffers the entire document body. This can be
506 potentially dangerous, since a server could just keep sending data indefinitely
507 and wait for your RAM to exhaust. With nasty consequences.
509 The buffer-limit option lets you set the maximum size in Kbytes that each
510 buffer may use. When the documents buffer exceeds this size, it is flushed to
511 the client unfiltered and no further attempt to filter the rest of it is made.
512 Remember that there may multiple threads running, which might require
513 increasing the "buffer-limit" Kbytes each, unless you have enabled
514 "single-threaded" above.
519 To enable the web-based actionsfile editor set enable-edit-actions to 1, or 0
520 to disable. Note that you must have compiled JunkBuster with support for this
521 feature, otherwise this option has no effect. This internal page can be reached
524 Security note: If this is enabled, anyone who can use the proxy can edit the
525 actions file, and their changes will affect all users. For shared proxies, you
526 probably want to disable this. Default: enabled.
528 enable-edit-actions 1
531 Allow JunkBuster to be toggled on and off remotely, using your web browser. Set
532 "enable-remote-toggle"to 1 to enable, and 0 to disable. Note that you must have
533 compiled JunkBuster with support for this feature, otherwise this option has no
536 Security note: If this is enabled, anyone who can use the proxy can toggle it
537 on or off (see http://i.j.b./), and their changes will affect all users. For
538 shared proxies, you probably want to disable this. Default: enabled.
540 enable-remote-toggle 1
543 -------------------------------------------------------------------------------
545 Access Control List (ACL)
547 Access controls are included at the request of some ISPs and systems
548 administrators, and are not usually needed by individual users. Please note the
549 warnings in the FAQ that this proxy is not intended to be a substitute for a
550 firewall or to encourage anyone to defer addressing basic security weaknesses.
552 If no access settings are specified, the proxy talks to anyone that connects.
553 If any access settings file are specified, then the proxy talks only to IP
554 addresses permitted somewhere in this file and not denied later in this file.
556 Summary -- if using an ACL:
558 Client must have permission to receive service.
560 LAST match in ACL wins.
562 Default behavior is to deny service.
564 The syntax for an entry in the Access Control List is:
566 ACTION SRC_ADDR[/SRC_MASKLEN] [ DST_ADDR[/DST_MASKLEN] ]
569 Where the individual fields are:
571 ACTION = "permit-access" or "deny-access"
573 SRC_ADDR = client hostname or dotted IP address
574 SRC_MASKLEN = number of bits in the subnet mask for the source
576 DST_ADDR = server or forwarder hostname or dotted IP address
577 DST_MASKLEN = number of bits in the subnet mask for the target
580 The field separator (FS) is whitespace (space or tab).
582 IMPORTANT NOTE: If the junkbuster is using a forwarder (see below) or a gateway
583 for a particular destination URL, the DST_ADDR that is examined is the address
584 of the forwarder or the gateway and NOT the address of the ultimate target.
585 This is necessary because it may be impossible for the local Junkbuster to
586 determine the address of the ultimate target (that's often what gateways are
589 Here are a few examples to show how the ACL features work:
591 "localhost" is OK -- no DST_ADDR implies that ALL destination addresses are OK:
593 permit-access localhost
596 A silly example to illustrate permitting any host on the class-C subnet with
597 Junkbuster to go anywhere:
599 permit-access www.junkbusters.com/24
602 Except deny one particular IP address from using it at all:
604 deny-access ident.junkbusters.com
607 You can also specify an explicit network address and subnet mask. Explicit
608 addresses do not have to be resolved to be used.
610 permit-access 207.153.200.0/24
613 A subnet mask of 0 matches anything, so the next line permits everyone.
615 permit-access 0.0.0.0/0
618 Note, you cannot say:
623 to allow all *.org domains. Every IP address listed must resolve fully.
625 An ISP may want to provide a Junkbuster that is accessible by "the world" and
626 yet restrict use of some of their private content to hosts on its internal
627 network (i.e. its own subscribers). Say, for instance the ISP owns the Class-B
628 IP address block 123.124.0.0 (a 16 bit netmask). This is how they could do it:
630 permit-access 0.0.0.0/0 0.0.0.0/0 # other clients can go anywhere
631 # with the following exceptions:
633 deny-access 0.0.0.0/0 123.124.0.0/16 # block all external requests for
634 # sites on the ISP's network
636 permit 0.0.0.0/0 www.my_isp.com # except for the ISP's main
639 permit 123.124.0.0/16 0.0.0.0/0 # the ISP's clients can go
643 Note that if some hostnames are listed with multiple IP addresses, the primary
644 value returned by DNS (via gethostbyname()) is used. Default: Anyone can access
647 -------------------------------------------------------------------------------
651 This feature allows chaining of HTTP requests via multiple proxies. It can be
652 used to better protect privacy and confidentiality when accessing specific
653 domains by routing requests to those domains to a special purpose filtering
654 proxy such as lpwa.com. Or to use a caching proxy to speed up browsing.
656 It can also be used in an environment with multiple networks to route requests
657 via multiple gateways allowing transparent access to multiple networks without
658 having to modify browser configurations.
660 Also specified here are SOCKS proxies. Junkbuster SOCKS 4 and SOCKS 4A. The
661 difference is that SOCKS 4A will resolve the target hostname using DNS on the
662 SOCKS server, not our local DNS client.
664 The syntax of each line is:
666 forward target_domain[:port] http_proxy_host[:port]
667 forward-socks4 target_domain[:port] socks_proxy_host[:port] http_proxy_host[:
669 forward-socks4a target_domain[:port] socks_proxy_host[:port] http_proxy_host[:
673 If http_proxy_host is ".", then requests are not forwarded to a HTTP proxy but
674 are made directly to the web servers.
676 Lines are checked in sequence, and the last match wins.
678 There is an implicit line equivalent to the following, which specifies that
679 anything not finding a match on the list is to go out without forwarding or
680 gateway protocol, like so:
682 forward .* . # implicit
685 In the following common configuration, everything goes to Lucent's LPWA, except
686 SSL on port 443 (which it doesn't handle):
688 forward .* lpwa.com:8000
692 See the FAQ for instructions on how to automate the login procedure for LPWA.
693 Some users have reported difficulties related to LPWA's use of "." as the last
694 element of the domain, and have said that this can be fixed with this:
696 forward lpwa. lpwa.com:8000
699 (NOTE: the syntax for specifiying target_domain has changed since the previous
700 paragraph was written -- it will not work now. More information is welcome.)
702 In this fictitious example, everything goes via an ISP's caching proxy, except
703 requests to that ISP:
705 forward .* caching.myisp.net:8000
709 For the @home network, we're told the forwarding configuration is this:
711 forward .* proxy:8080
714 Also, we're told they insist on getting cookies and JavaScript, so you need to
715 add home.com to the cookie file. We consider JavaScript a security risk. Java
718 In this example direct connections are made to all "internal" domains, but
719 everything else goes through Lucent's LPWA by way of the company's SOCKS
720 gateway to the Internet.
722 forward_socks4 .* lpwa.com:8000 firewall.my_company.com:1080
723 forward my_company.com .
726 This is how you could set up a site that always uses SOCKS but no forwarders:
728 forward_socks4a .* . firewall.my_company.com:1080
731 An advanced example for network administrators:
733 If you have links to multiple ISPs that provide various special content to
734 their subscribers, you can configure forwarding to pass requests to the
735 specific host that's connected to that ISP so that everybody can see all of the
736 content on all of the ISPs.
738 This is a bit tricky, but here's an example:
740 host-a has a PPP connection to isp-a.com. And host-b has a PPP connection to
741 isp-b.com. host-a can run a Junkbuster proxy with forwarding like this:
744 forward isp-b.com host-b:8000
747 host-b can run a Junkbuster proxy with forwarding like this:
750 forward isp-a.com host-a:8000
753 Now, anyone on the Internet (including users on host-a and host-b) can set
754 their browser's proxy to either host-a or host-b and be able to browse the
755 content on isp-a or isp-b.
757 Here's another practical example, for University of Kent at Canterbury students
758 with a network connection in their room, who need to use the University's Squid
761 forward *. ssbcache.ukc.ac.uk:3128 # Use the proxy, except for:
762 forward .ukc.ac.uk . # Anything on the same domain as us
763 forward * . # Host with no domain specified
764 forward 129.12.*.* . # A dotted IP on our /16 network.
765 forward 127.*.*.* . # Loopback address
766 forward localhost.localdomain . # Loopback address
767 forward www.ukc.mirror.ac.uk . # Specific host
770 If you intend to chain Junkbuster and squid locally, then chain as browser ->
771 squid -> junkbuster is the recommended way.
773 Your squid configuration could then look like this:
775 # Define junkbuster as parent cache
777 cache_peer 127.0.0.1 parent 8000 0 no-query
779 # Define ACL for protocol FTP
782 # Do not forward ACL FTP to junkbuster
783 always_direct allow FTP
785 # Do not forward ACL CONNECT (https) to junkbuster
786 always_direct allow CONNECT
788 # Forward the rest to junkbuster
789 never_direct allow all
792 -------------------------------------------------------------------------------
796 Junkbuster has a number of options specific to the Windows GUI interface:
798 If "activity-animation" is set to 1, the Junkbuster icon will animate when
799 "Junkbuster" is active. To turn off, set to 0.
804 If "log-messages" is set to 1, Junkbuster will log messages to the console
810 If "log-buffer-size" is set to 1, the size of the log buffer, i.e. the amount
811 of memory used for the log messages displayed in the console window, will be
812 limited to "log-max-lines" (see below).
814 Warning: Setting this to 0 will result in the buffer to grow infinitely and eat
820 log-max-lines is the maximum number of lines held in the log buffer. See above.
825 If "log-highlight-messages" is set to 1, Junkbuster will highlight portions of
826 the log messages with a bold-faced font:
828 log-highlight-messages 1
831 The font used in the console window:
833 log-font-name Comic Sans MS
836 Font size used in the console window:
841 "show-on-task-bar" controls whether or not Junkbuster will appear as a button
842 on the Task bar when minimized:
847 If "close-button-minimizes" is set to 1, the Windows close button will minimize
848 Junkbuster instead of closing the program (close with the exit option on the
851 close-button-minimizes 1
854 The "hide-console" option is specific to the MS-Win console version of
855 JunkBuster. If this option is used, Junkbuster will disconnect from and hide
861 -------------------------------------------------------------------------------
865 The "actionsfile" is used to define what actions Junkbuster takes, and thus
866 determines how images, cookies and various other aspects of HTTP content and
867 transactions are handled. Images can be anything you want, including ads,
868 banners, or just some obnoxious image that you would rather not see. Cookies
869 can be accepted or rejected. The default file is in fact named actionsfile.
871 To determine which actions apply to a request, the URL of the request is
872 compared to all patterns in this file. Every time it matches, the list of
873 applicable actions for the URL is incrementally updated. You can trace this
874 process by visiting http://i.j.b/show-url-info.
876 The actions file can be edited with a browser by loading http://i.j.b, and then
877 select "Edit Actions".
879 There are four types of lines in this file: comments (begin with a "#"
880 character), actions, aliases and patterns, all of which are explained below, as
881 well as the configuration file syntax that Junkbuster understands.
883 -------------------------------------------------------------------------------
885 URL Domain and Path Syntax
887 Generally, a pattern has the form <domain>/<path>, where both the <domain> and
888 <path> part are optional. If you only specify a domain part, the "/" can be
891 www.example.com - is a domain only pattern and will match any request to
894 www.example.com/ - means exactly the same.
896 www.example.com/index.html - matches only the single document "/index.html" on
899 /index.html - matches the document "/index.html", regardless of the domain.
901 index.html - matches nothing, since it would be interpreted as a domain name
902 and there is no top-level domain called ".html".
904 The matching of the domain part offers some flexible options: if the domain
905 starts or ends with a dot, it becomes unanchored at that end. For example:
907 .example.com - matches any domain that ENDS in ".example.com".
909 www. - matches any domain that STARTS with "www".
911 Additionally, there are wildcards that you can use in the domain names
912 themselves. They work pretty similar to shell wildcards: "*" stands for zero or
913 more arbitrary characters, "?" stands for any single character. And you can
914 define charachter classes in square brackets and they can be freely mixed:
916 ad*.example.com - matches "adserver.example.com", "ads.example.com", etc but
917 not "sfads.example.com".
919 *ad*.example.com - matches all of the above, and then some.
921 .?pix.com - matches "www.ipix.com", "pictures.epix.com", "a.b.c.d.e.upix.com",
924 www[1-9a-ez].example.com - matches "www1.example.com", "www4.example.com",
925 "wwwd.example.com", "wwwz.example.com", etc., but not "wwww.example.com".
927 If Junkbuster was compiled with "pcre" support (default), Perl compatible
928 regular expressions can be used. See the pcre/docs/ direcory or "man perlre"
929 (also available on http://www.perldoc.com/perl5.6/pod/perlre.html) for details.
930 A brief discussion of regular expressions is in the Appendix. For instance:
932 /.*/advert[0-9]+\.jpe?g - would match a URL from any domain, with any path that
933 includes "advert" followed immediately by one or more digits, then a "." and
934 ending in either "jpeg" or "jpg". So we match "example.com/ads/advert2.jpg",
935 and "www.example.com/ads/banners/advert39.jpeg", but not "www.example.com/ads/
936 banners/advert39.gif" (no gifs in the example pattern).
938 Please note that matching in the path is case INSENSITIVE by default, but you
939 can switch to case sensitive at any point in the pattern by using the "(?-i)"
942 www.example.com/(?-i)PaTtErN.* - will match only documents whose path starts
943 with "PaTtErN" in exactly this capitalization.
945 -------------------------------------------------------------------------------
949 Actions are enabled if preceded with a "+", and disabled if preceded with a
950 "-". Actions are invoked by enclosing the action name in curly braces (e.g.
951 {+some_action}), followed by a list of URLs to which the action applies. There
952 are three classes of actions:
954 * Boolean (e.g. "+/-block"):
956 {+name} # enable this action
957 {-name} # disable this action
960 * Parameterized (e.g. "+/-hide-user-agent"):
962 {+name{param}} # enable action and set parameter to "param"
963 {-name} # disable action
966 * Multi-value (e.g. "{+/-add-header{Name: value}}", "{+/-wafer{name=value}}
969 {+name{param}} # enable action and add parameter "param"
970 {-name{param}} # remove the parameter "param"
971 {-name} # disable this action totally
974 If nothing is specified in this file, no "actions" are taken. So in this case
975 JunkBuster would just be a normal, non-blocking, non-anonymizing proxy. You
976 must specifically enable the privacy and blocking features you need (although
977 the provided default actionsfile file will give a good starting point).
979 Later defined actions always over-ride earlier ones. For multi-valued actions,
980 the actions are applied in the order they are specified.
982 The list of valid Junkbuster "actions" are:
984 * Add the specified HTTP header, which is not checked for validity. You may
985 specify this many times to specify many different headers:
987 +add-header{Name: value}
990 * Block this URL totally.
995 * De-animate all animated GIF images, i.e. reduce them to their last frame.
996 This will also shrink the images considerably (in bytes, not pixels!). If
997 the option "first" is given, the first frame of the animation is used as
998 the replacement. If "last" is given, the last frame of the animation is
999 used instead, which propably makes more sense for most banner animations,
1000 but also has the risk of not showing the entire last frame (if it is only a
1001 delta to an earlier frame).
1003 +deanimate-gifs{last}
1004 +deanimate-gifs{first}
1007 * "+downgrade" will downgrade HTTP/1.1 client requests to HTTP/1.0 and
1008 downgrade the responses as well. Use this action for servers that use HTTP/
1009 1.1 protocol features that Junkbuster doesn't handle well yet. HTTP/1.1 is
1010 only partially implemented. Default is not to downgrade requests.
1015 * Many sites, like yahoo.com, don't just link to other sites. Instead, they
1016 will link to some script on their own server, giving the destination as a
1017 parameter, which will then redirect you to the final target. URLs resulting
1018 from this scheme typically look like: http://some.place/some_script?http://
1021 Sometimes, there are even multiple consecutive redirects encoded in the
1022 URL. These redirections via scripts make your web browing more traceable,
1023 since the server from which you follow such a link can see where you go to.
1024 Apart from that, valuable bandwidth and time is wasted, while your browser
1025 ask the server for one redirect after the other. Plus, it feeds the
1028 The "+fast-redirects" option enables interception of these requests by
1029 Junkbuster, who will cut off all but the last valid URL in the request and
1030 send a local redirect back to your browser without contacting the remote
1036 * Filter the website through the re_filterfile:
1041 * Block any existing X-Forwarded-for header, and do not add a new one:
1046 * If the browser sends a "From:" header containing your e-mail address, this
1047 either completely removes the header ("block"), or changes it to the
1048 specified e-mail address.
1051 +hide-from{spam@sittingduck.xqq}
1054 * Don't send the "Referer:" (sic) header to the web site. You can block it,
1055 forge a URL to the same server as the request (which is preferred because
1056 some sites will not send images otherwise) or set it to a constant string
1059 +hide-referer{block}
1060 +hide-referer{forge}
1061 +hide-referer{http://nowhere.com}
1064 * Alternative spelling of "+hide-referer". It has the same parameters, and
1065 can be freely mixed with, "+hide-referer". ("referrer" is the correct
1066 English spelling, however the HTTP specification has a bug - it requires it
1067 to be spelled "referer".)
1072 * Change the "User-Agent:" header so web servers can't tell your browser
1073 type. Warning! This breaks many web sites. Specify the user-agent value you
1074 want. Example, pretend to be using Netscape on Linux:
1076 +hide-user-agent{Mozilla (X11; I; Linux 2.0.32 i586)}
1079 * Treat this URL as an image. This only matters if it's also "+block"ed, in
1080 which case a "blocked" image can be sent rather than a HTML page. See
1081 "+image-blocker{}" below for the control over what is actually sent.
1086 * Decides what to do with URLs that end up tagged with "{+block +image}".
1087 There are 4 options. "-image-blocker" will send a HTML "blocked" page,
1088 usually resulting in a "broken image" icon. "+image-blocker{logo}" will
1089 send a "JunkBuster" image. "+image-blocker{blank}" will send a 1x1
1090 transparent GIF image. And finally, "+image-blocker{http://xyz.com}" will
1091 send a HTTP temporary redirect to the specified image. This has the
1092 advantage of the icon being being cached by the browser, which will speed
1095 +image-blocker{logo}
1096 +image-blocker{blank}
1097 +image-blocker{http://i.j.b/send-banner}
1100 * By default (i.e. in the absence of a "+limit-connect" action), Junkbuster
1101 will only allow CONNECT requests to port 443, which is the standard port
1102 for https as a precaution.
1104 The CONNECT methods exists in HTTP to allow access to secure websites
1105 (https:// URLs) through proxies. It works very simply: the proxy connects
1106 to the server on the specified port, and then short-circuits its
1107 connections to the client and to the remote proxy. This can be a big
1108 security hole, since CONNECT-enabled proxies can be abused as TCP relays
1111 If you want to allow CONNECT for more ports than this, or want to forbid
1112 CONNECT altogether, you can specify a comma separated list of ports and
1113 port ranges (the latter using dashes, with the minimum defaulting to 0 and
1116 +limit-connect{443} # This is the default and need no be specified.
1117 +limit-connect{80,443} # Ports 80 and 443 are OK.
1118 +limit-connect{-3, 7, 20-100, 500-} # Port less than 3, 7, 20 to 100
1119 #and above 500 are OK.
1122 * "+no-compression" prevents the website from compressing the data. Some
1123 websites do this, which can be a problem for Junkbuster, since "+filter",
1124 "+no-popup" and "+gif-deanimate" will not work on compressed data. This
1125 will slow down connections to those websites, though. Default is
1126 "nocompression" is turned on.
1131 * Prevent the website from reading cookies:
1136 * Prevent the website from setting cookies:
1141 * Filter the website through a built-in filter to disable those obnoxious
1142 JavaScript pop-up windows via window.open(), etc. The two alternative
1143 spellings are equivalent.
1149 * This action only applies if you are using a jarfile for saving cookies. It
1150 sends a cookie to every site stating that you do not accept any copyright
1151 on cookies sent to you, and asking them not to track you. Of course, this
1152 is a (relatively) unique header they could use to track you.
1157 * This allows you to add an arbitrary cookie. It can be specified multiple
1158 times in order to add as many cookies as you like.
1163 The meaning of any of the above is reversed by preceding the action with a "-",
1164 in place of the "+".
1168 Turn off cookies by default, then allow a few through for specified sites:
1170 # Turn off all cookies
1171 { +no-cookies-read }
1174 # Execeptions to the above, sites that need cookies
1175 { -no-cookies-read }
1183 # Alternative way of saying the same thing
1184 {-no-cookies-set -no-cookies-read}
1189 Now turn off "fast redirects", and then we allow two exceptions:
1194 # Reverse it for these two sites, which don't work right without it.
1196 www.ukc.ac.uk/cgi-bin/wac\.cgi\?
1200 Turn on page filtering, with one exception for sourceforge:
1202 # Run everything through the default filter file (re_filterfile):
1205 # But please don't re_filter code from sourceforge!
1207 .cvs.sourceforge.net
1210 Now some URLs that we want "blocked", ie we won't see them. Many of these use
1211 regular expressions that will expand to match multiple URLs:
1215 /.*/(.*[-_.])?ads?[0-9]?(/|[-_.].*|\.(gif|jpe?g))
1216 /.*/(.*[-_.])?count(er)?(\.cgi|\.dll|\.exe|[?/])
1217 /.*/(ng)?adclient\.cgi
1218 /.*/(plain|live|rotate)[-_.]?ads?/
1219 /.*/(sponsor)s?[0-9]?/
1220 /.*/_?(plain|live)?ads?(-banners)?/
1222 /.*/ad(sdna_image|gifs?)/
1223 /.*/ad(server|stream|juggler)\.(cgi|pl|dll|exe)
1227 /.*/adv((er)?ts?|ertis(ing|ements?))?/
1231 /.*/cgi-bin/centralad/getimage
1232 /.*/images/addver\.gif
1233 /.*/images/marketing/.*\.(gif|jpe?g)
1237 /.*/sponsors?[0-9]?/
1238 /.*/advert[0-9]+\.jpg
1245 /graphics/defaultAd/
1247 /image\.ng/transactionID
1248 /images/.*/.*_anim\.gif # alvin brattli
1249 /ip_img/.*\.(gif|jpe?g)
1253 /cgi-bin/nph-adclick.exe/
1254 /.*/Image/BannerAdvertising/
1256 /.*/adlib/server\.cgi
1260 -------------------------------------------------------------------------------
1264 Custom "actions", known to Junkbuster as "aliases", can be defined by combining
1265 other "actions". These can in turn be invoked just like the built-in "actions".
1266 Currently, an alias can contain any character except space, tab, "=", "{" or "}
1267 ". But please use only "a"- "z", "0"-"9", "+", and "-". Alias names are not
1268 case sensitive, and must be defined before anything else in actionsfile! And
1269 there can only be one set of "aliases" defined.
1271 Now let's define a few aliases:
1273 # Useful customer aliases we can use later. These must come first!
1275 +no-cookies = +no-cookies-set +no-cookies-read
1276 -no-cookies = -no-cookies-set -no-cookies-read
1278 -block -no-cookies -filter -fast-redirects -hide-referer -no-popups
1279 shop = -no-cookies -filter -fast-redirects
1280 +imageblock = +block +image
1282 #For people who don't like to type too much: ;-)
1285 c2 = -no-cookies-set +no-cookies-read
1286 c3 = +no-cookies-set -no-cookies-read
1287 #... etc. Customize to your heart's content.
1290 Some examples using our "shop" and "fragile" aliases from above:
1292 # These sites are very complex and require
1293 # minimal interference.
1295 .office.microsoft.com
1296 .windowsupdate.microsoft.com
1299 # Shopping sites - still want to block ads.
1302 .worldpay.com # for quietpc.com
1306 # These shops require pop-ups
1312 -------------------------------------------------------------------------------
1316 The filter file defines what filtering of web pages Junkbuster does. The
1317 default filter file is re_filterfile, located in the config directory. In this
1318 file, any document content, whether viewable text or embedded non-visible
1319 content, can be changed.
1321 This file uses regular expressions to alter or remove any string in the target
1322 page. Some examples from the included default re_filterfile:
1324 Stop web pages from displaying annoying messages in the status bar by deleting
1327 # The status bar is for displaying link targets, not pointless buzzwords.
1328 # Again, check it out on http://www.airport-cgn.de/.
1329 s/status='.*?';*//ig
1332 Just for kicks, replace any occurrence of "Microsoft" with "MicroSuck":
1334 s/microsoft(?!.com)/MicroSuck/ig
1337 Kill those auto-refresh tags:
1339 # Kill refresh tags. I like to refresh myself. Manually.
1340 # check it out on http://www.airport-cgn.de/ and go to the arrivals page.
1342 s/<meta[^>]*http-equiv[^>]*refresh.*URL=([^>]*?)"?>/<link rev="x-refresh" href
1344 s/<meta[^>]*http-equiv="?page-enter"?[^>]*content=[^>]*>/<!
1345 --no page enter for me-->/i
1348 -------------------------------------------------------------------------------
1350 Quickstart to Using Junkbuster
1352 Install package, then run and enjoy! Junbuster accepts only one command line
1353 option -- the configuration file to be used. Example Unix startup command:
1356 # /usr/sbin/junkbuster /etc/junkbuster/config &
1360 If no configuration file is specified on the command line, Junkbuster will look
1361 for a file named config in the current directory. Except on Amiga where it will
1362 look for AmiTCP:db/junkbuster/config and Win32 where it will try junkbstr.txt.
1363 If no file is specified on the command line and no default configuration file
1364 can be found, Junkbuster will fail to start.
1366 Be sure your browser is set to use the proxy which is by default at localhost,
1367 port 8000. With Netscape (and Mozilla), this can be set under Edit ->
1368 Preferences -> Advanced -> Proxies -> HTTP Proxy. For Internet Explorer: Tools
1369 > Internet Properties -> Connections -> LAN Setting. Then, check "Use Proxy"
1370 and fill in the appropriate info (Address: localhost, Port: 8000). Include if
1371 HTTPS proxy support too.
1373 The included default configuration files should give a reasonable starting
1374 point, though may be somewhat aggressive in blocking junk. You will probably
1375 want to keep an eye out for sites that require cookies, and add these to
1376 actionsfile as needed. By default, most of these will be blocked until you add
1377 them to the configuration. If you want the browser to handle this instead, you
1378 will need to edit actionsfile and disable this feature. If you use more than
1379 one browser, it would make more sense to let Junkbuster handle this. In which
1380 case, the browser(s) should be set to accept all cookies.
1382 If a particular site shows problems loading properly, try adding it to the
1383 {fragile} section of actionsfile. This will turn off most actions for this
1386 HTTP/1.1 support is not fully implemented. If browsers that support HTTP/1.1
1387 (like Mozilla or recent versions of I.E.) experience problems, you might try to
1388 force HTTP/1.0 compatiblity. For Mozilla, look under Edit -> Preferences ->
1389 Debug -> Networking. Or set the "+downgrade" config option in actionsfile.
1391 After running Junkbuster for a while, you can start to fine tune the
1392 configuration to suit your personal, or site, preferences and requirements.
1393 There are many, many aspects that can be customized. "Actions" (from
1394 actionsfile) can be adjusted by pointing your browser to http://i.j.b./, and
1395 then follow the link to "edit the actions list". (This is an internal page and
1396 does not require Internet access.)
1398 In fact, various aspects of Junkbuster configuration can be viewed from this
1399 page, including current configuration parameters, source code version numbers,
1400 the browser's request headers, and "actions" that apply to a given URL. In
1401 addition to the actionsfile editor mentioned above, Junkbuster can also be
1402 turned "on" and "off" from this page.
1404 If you encounter problems, please verify it is a Junkbuster bug, by disabling
1405 Junkbuster, and then trying the same page. Also, try another browser if
1406 possible to eliminate browser or site problems. Before reporting it as a bug,
1407 see if there is not a configuration option that is enabled that is causing the
1408 page not to load. You can then add an exception for that page or site. If a
1409 bug, please report it to the developers (see below).
1411 -------------------------------------------------------------------------------
1413 Contact the Developers
1415 Feature requests and other questions should be posted to the Feature request
1416 page at SourceForge. There is also an archive there.
1418 Anyone interested in actively participating in development and related
1419 discussions can join the appropriate mailing list here. Archives are available
1422 Please report bugs, using the form at Sourceforge. Please try to verify that it
1423 is a Junkbuster bug, and not a browser or site bug first. Also, check to make
1424 sure this is not already a known bug.
1426 -------------------------------------------------------------------------------
1428 Copyright and History
1432 Internet Junkbuster is free software; you can redistribute it and/or modify it
1433 under the terms of the GNU General Public License as published by the Free
1434 Software Foundation; either version 2 of the License, or (at your option) any
1437 This program is distributed in the hope that it will be useful, but WITHOUT ANY
1438 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
1439 PARTICULAR PURPOSE. See the GNU General Public License for more details, which
1440 is available from the Free Software Foundation, Inc, 59 Temple Place - Suite
1441 330, Boston, MA 02111-1307, USA.
1443 -------------------------------------------------------------------------------
1447 Junkbuster was originally written by Anonymous Coders and JunkBusters
1448 Corporation, and was released as free open-source software under the GNU GPL.
1449 Stefan Waldherr made many improvements, and started the SourceForge project to
1450 rekindle development. The last stable release was v2.0.2, which has now grown
1453 -------------------------------------------------------------------------------
1457 http://sourceforge.net/projects/ijbswa
1459 http://ijbswa.sourceforge.net/
1463 http://www.junkbusters.com/ht/en/cookies.html
1465 http://www.waldherr.org/junkbuster/
1467 http://privacy.net/analyze/
1469 http://www.squid-cache.org/
1473 -------------------------------------------------------------------------------
1479 Junkbuster can use "regular expressions" in various config files. Assuming
1480 support for "pcre" (Perl Compatible Regular Expressions) is compiled in, which
1481 is the default. Such configuration directives do not require regular
1482 expressions, but they can be used to increase flexibility by matching a pattern
1483 with wildcards against URLs.
1485 If you are reading this, you probably don't understand what "regular
1486 expressions" are, or what they can do. So this will be a very brief
1487 introduction only. A full explanation would require a book ;-)
1489 "Regular expressions" is a way of matching one character expression against
1490 another to see if it matches or not. One of the "expressions" is a literal
1491 string of readable characters (letter, numbers, etc), and the other is a
1492 complex string of literal characters combined with wildcards, and other special
1493 characters, called metacharacters. The "metacharacters" have special meanings
1494 and are used to build the complex pattern to be matched against. Perl
1495 Compatible Regular Expressions is an enhanced form of the regular expression
1496 language with backward compatibility.
1498 To make a simple analogy, we do something similar when we use wildcard
1499 characters when listing files with the dir command in DOS. *.* matches all
1500 filenames. The "special" character here is the asterik which matches any and
1501 all characters. We can be more specific and use ? to match just individual
1502 characters. So "dir file?.text" would match "file1.txt", "file2.txt", etc. We
1503 are pattern matching, using a similar technique to "regular expressions"!
1505 Regular expressions do essentially the same thing, but are much, much more
1506 powerful. There are many more "special characters" and ways of building complex
1507 patterns however. Let's look at a few of the common ones, and then some
1510 . - Matches any single character, e.g. "a", "A", "4", ":", or "@".
1512 ? - The preceding character or expression is matched ZERO or ONE times. Either/
1515 + - The preceding character or expression is matched ONE or MORE times.
1517 * - The preceding character or expression is matched ZERO or MORE times.
1519 \ - The "escape" character denotes that the following character should be taken
1520 literally. This is used where one of the special characters (e.g. ".") needs to
1521 be taken literally and not as a special metacharacter.
1523 [] - Characters enclosed in brackets will be matched if any of the enclosed
1524 characters are encountered.
1526 () - Pararentheses are used to group a sub-expression, or multiple
1529 | - The "bar" character works like an "or" conditional statement. A match is
1530 successful if the sub-expression on either side of "|" matches.
1532 s/string1/string2/g - This is used to rewrite strings of text. "string1" is
1533 replaced by "string2" in this example.
1535 These are just some of the ones you are likely to use when matching URLs with
1536 Junkbuster, and is a long way from a definitive list. This is enough to get us
1537 started with a few simple examples which may be more illuminating:
1539 /.*/banners/.* - A simple example that uses the common combination of "." and "
1540 *" to denote any character, zero or more times. In other words, any string at
1541 all. So we start with a literal forward slash, then our regular expression
1542 pattern (".*") another literal forward slash, the string "banners", another
1543 forward slash, and lastly another ".*". We are building a directory path here.
1544 This will match any file with the path that has a directory named "banners" in
1545 it. The ".*" matches any characters, and this could conceivably be more forward
1546 slashes, so it might expand into a much longer looking path. For example, this
1547 could match: "/eye/hate/spammers/banners/annoy_me_please.gif", or just "/
1548 banners/annoying.html", or almost an infinite number of other possible
1549 combinations, just so it has "banners" in the path somewhere.
1551 A now something a little more complex:
1553 /.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward
1554 slashes again ("/"), so we are building another expression that is a file path
1555 statement. We have another ".*", so we are matching against any conceivable
1556 sub-path, just so it matches our expression. The only true literal that must
1557 match our pattern is adv, together with the forward slashes. What comes after
1558 the "adv" string is the interesting part.
1560 Remember the "?" means the preceding expression (either a literal character or
1561 anything grouped with "(...)" in this case) can exist or not, since this means
1562 either zero or one match. So "((er)?ts?|ertis(ing|ements?))" is optional, as
1563 are the individual sub-expressions: "(er)", "(ing|ements?)", and the "s". The "
1564 |" means "or". We have two of those. For instance, "(ing|ements?)", can expand
1565 to match either "ing" OR "ements?". What is being done here, is an attempt at
1566 matching as many variations of "advertisement", and similar, as possible. So
1567 this would expand to match just "adv", or "advert", or "adverts", or
1568 "advertising", or "advertisement", or "advertisements". You get the idea. But
1569 it would not match "advertizements" (with a "z"). We could fix that by changing
1570 our regular expression to: "/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/", which
1571 would then match either spelling.
1573 /.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward
1574 slashes. Anything in the square brackets "[]" can be matched. This is using
1575 "0-9" as a shorthand expression to mean any digit one through nine. It is the
1576 same as saying "0123456789". So any digit matches. The "+" means one or more of
1577 the preceding expression must be included. The preceding expression here is
1578 what is in the square brackets -- in this case, any digit one through nine.
1579 Then, at the end, we have a grouping: "(gif|jpe?g)". This includes a "|", so
1580 this needs to match the expression on either side of that bar character also. A
1581 simple "gif" on one side, and the other side will in turn match either "jpeg"
1582 or "jpg", since the "?" means the letter "e" is optional and can be matched
1583 once or not at all. So we are building an expression here to match image GIF or
1584 JPEG type image file. It must include the literal string "advert", then one or
1585 more digits, and a "." (which is now a literal, and not a special character,
1586 since it is escaped with "\"), and lastly either "gif", or "jpeg", or "jpg".
1587 Some possible matches would include: "//advert1.jpg", "/nasty/ads/
1588 advert1234.gif", "/banners/from/hell/advert99.jpg". It would not match
1589 "advert1.gif" (no leading slash), or "/adverts232.jpg" (the expression does not
1590 include an "s"), or "/advert1.jsp" ("jsp" is not in the expression anywhere).
1592 s/microsoft(?!.com)/MicroSuck/i - This is a substitution. "MicroSuck" will
1593 replace any occurence of "microsoft". The "i" at the end of the expression
1594 means ignore case. The "(?!.com)" means the match should fail if "microsoft" is
1595 followed by ".com". In other words, this acts like a "NOT" modifier. In case
1596 this is a hyperlink, we don't want to break it ;-).
1598 We are barely scratching the surface of regular expressions here so that you
1599 can understand the default Junkbuster configuration files, and maybe use this
1600 knowledge to customize your own installation. There is much, much more that can
1601 be done with regular expressions. Now that you know enough to get started, you
1602 can learn more on your own :/
1604 More reading on Perl Compatible Regular expressions: http://www.perldoc.com/
1605 perl5.6/pod/perlre.html