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 * Modularized configuration that will allow for system wide settings, and
63 individual user settings.
65 * A browser based GUI configuration utility (not finished).
67 * Blocking of annoying pop-up browser windows (previously available as a
70 * Partial support for HTTP/1.1.
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 -------------------------------------------------------------------------------
84 Junkbuster is available as raw source code, or pre-compiled binaries. See the
85 Junkbuster Home Page for current release info. Junkbuster is also available via
86 CVS. This is the recommended approach at this time. But please be aware that
87 CVS is constantly changing, and it may break in mysterious ways.
89 -------------------------------------------------------------------------------
93 For gzipped tar archives, unpack the source:
95 tar zxvf ijb_source_2.9*
99 For retrieving the current CVS sources, you'll need the CVS package installed
100 first. To download CVS source:
102 cvs -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa login
103 cvs -z3 -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa co current
107 This will create a directory named current/, which will contain the source
110 Then, in either case, to build from source:
112 autoconf #recommended for CVS source
119 For Redhat and SuSE Linux RPM packages, see below.
121 -------------------------------------------------------------------------------
125 To build Redhat RPM packages, install source as above. Then:
127 autoconf #recommended for CVS source
132 This will create both binary and src RPMs in the usual places. Example:
134 /usr/src/redhat/RPMS/i686/junkbuster-2.9.8-1.i686.rpm
136 /usr/src/redhat/SRPMS/junkbuster-2.9.9-1.src.rpm
138 To install, of course:
140 rpm -Uvv /usr/src/redhat/RPMS/i686/junkbuster-2.9.9-1.i686.rpm
143 This will place the Junkbuster configuration files in /etc/junkbuster/, and log
144 files in /var/log/junkbuster/.
146 -------------------------------------------------------------------------------
150 To build SuSE RPM packages, install source as above. Then:
152 autoconf #recommended for CVS source
157 This will create both binary and src RPMs in the usual places. Example:
159 /usr/src/suse/RPMS/i686/junkbuster-2.9.9-1.i686.rpm
161 /usr/src/suse/SRPMS/junkbuster-2.9.9-1.src.rpm
163 To install, of course:
165 rpm -Uvv /usr/src/suse/RPMS/i686/junkbuster-2.9.9-1.i686.rpm
168 This will place the Junkbuster configuration files in /etc/junkbuster/, and log
169 files in /var/log/junkbuster/.
171 -------------------------------------------------------------------------------
175 The OS/2 version of Junkbuster requires the EMX runtime library to be
176 installed. The EMX runtime library is available on the hobbes OS/2 archive,
177 among many other locations: http://hobbes.nmsu.edu/cgi-bin/h-search?sh=1&button
178 =Search&key=emxrt.zip&stype=all&sort=type&dir=%2Fpub%2Fos2%2Fdev%2Femx%2Fv0.9d
180 Junkbuster is packaged in a WarpIN self- installing archive. The
181 self-installing program will be named depending on the release version,
182 something like: ijbos123.exe. In order to install it, simply run this
183 executable or double-click on its icon and follow the WarpIN installation
184 panels. A shadow of the Junkbuster executable will be placed in your startup
185 folder so it will start automatically whenever OS/2 starts.
187 The directory you choose to install Junkbuster into will contain all of the
190 If you would like to build binary images on OS/2 yourself, you will need a
191 working EMX/GCC environment, plus several Unix-like tools. The Hobbes OS/2
192 archive is a good place to start when building such an environment. A set of
193 Unix-like tools named gnupack is located here: http://hobbes.nmsu.edu/cgi-bin/
194 h-search?sh=1&key=gnupack&stype=all&sort=type&dir=%2Fpub%2Fos2%2Fapps
196 Once you have the source code unpacked as above, you can build the binaries
197 from the current/ directory:
204 -------------------------------------------------------------------------------
208 Click-click. (I need help on this. Not a clue here. Also for configuration
211 -------------------------------------------------------------------------------
215 Some quick notes on other Operating Systems.
217 For FreeBSD (and other *BSDs?), the build will need gmake instead of the
218 included make. gmake is available from http://www.gnu.org. The rest should be
219 the same as above for Linux/Unix.
221 -------------------------------------------------------------------------------
223 Junkbuster Configuration
225 For Unix, *BSD and Linux, all configuraton files are located in /etc/junkbuster
226 / by default. For MS Windows and OS/2, these are all in the same directory as
227 the Junkbuster executable. The name and number of configuration files has
228 changed from previous versions, and is subject to change as development
231 The installed defaults provide a reasonable starting point. For the time being,
232 there are only three default configuration files (this will change in time):
234 * The main configuration file is named config on Linux, Unix, BSD, and OS/2,
235 and junkbustr.txt on Windows. On Amiga, it is AmiTCP:db/junkbuster/config.
237 * The actionsfile file is used to define various actions relating to images,
238 banners, pop-ups, banners and cookies. There is a CGI based editor for this
239 file that can be accessed via http://ijbswa.sourceforge.net/config/. (Still
240 under active development.)
242 * The re_filterfile file can be used to rewrite the raw page content,
243 including text as well as embedded HTML and JavaScript.
245 actionsfile and re_filterfile can use Perl style regular expressions for
246 maximum flexibility. All files use the "#" character to denote a comment. Such
247 lines are not processed by Junkbuster. After making any changes, restart
248 Junkbuster in order for the changes to take effect.
250 -------------------------------------------------------------------------------
252 The Main Configuration File
254 Again, the main configuration file is named config on Linux/Unix/BSD and OS/2,
255 and junkbustr.txt on Windows. Configuration lines consist of an initial keyword
256 followed by a list of values, all separated by whitespace (any number of spaces
257 or tabs). For example:
259 blockfile blocklist.ini
262 Indicates that the blockfile is named "blocklist.ini".
264 A "#" indicates a comment. Any part of a line following a "#" is ignored,
265 except if the "#" is preceded by a "\".
267 Thus, by placing a "#" at the start of an existing configuration line, you can
268 make it a comment and it will be treated as if it weren't there. This is called
269 "commenting out" an option and can be useful to turn off features: If you
270 comment out the "logfile" line, junkbuster will not log to a file at all. Watch
271 for the "default:" section in each explanation to see what happens if the
272 option is left unset (or commented out).
274 Long lines can be continued on the next line by using a "\" as the very last
277 There are various aspects of Junkbuster behavior that can be tuned.
279 -------------------------------------------------------------------------------
281 Defining Other Configuration Files
283 Junkbuster can use a number of other files to tell it what ads to block, what
284 cookies to accept, etc. This section of the configuration file tells Junkbuster
285 where to find all those other files.
287 On Windows, Junkbuster looks for these files in the same directory as the
288 executable. On Unix and OS/2, Junkbuster looks for these files in the current
289 working directory. In either case, an absolute path name can be used to avoid
292 When development goes modular and multiuser, the blocker, filter, and per-user
293 config will be stored in subdirectories of "confdir". For now, only confdir/
294 templates is used for storing HTML templates for CGI results.
296 The location of the configuration files:
298 confdir /etc/junkbuster # No trailing /, please.
301 The directory where all logging (i.e. logfile and jarfile) takes place. No
302 trailing "/", please:
304 logdir /var/log/junkbuster
307 Note that all file specifications below are relative to the above two
310 The "actionsfile" contains patterns to specify the actions to apply to requests
311 for each site. Default: Cookies to and from all destinations are filtered.
312 Popups are disabled for all sites. All sites are filtered if re_filterfile
313 specified. No sites are blocked. An empty image is displayed for filtered ads
314 and other images (formerly "tinygif"). The syntax of this file is explained in
317 actionsfile actionsfile
320 The "re_filterfile" file contains content modification rules. These rules
321 permit powerful changes on the content of Web pages, e.g., you could disable
322 your favourite JavaScript annoyances, rewrite the actual content, or just have
323 some fun replacing "Microsoft" with "MicroSuck" wherever it appears on a Web
324 page. Default: No content modification, or whatever the developers are playing
327 re_filterfile re_filterfile
330 The logfile is where all logging and error messages are written. The logfile
331 can be useful for tracking down a problem with Junkbuster (e.g., it's not
332 blocking an ad you think it should block) but in most cases you probably will
335 Your logfile will grow indefinitely, and you will probably want to periodically
336 remove it. On Unix systems, you can do this with a cron job (see "man cron").
337 For Redhat, a logrotate script has been included.
339 On SuSE Linux systems, you can place a line like "/var/log/junkbuster.* +1024k
340 644 nobody.nogroup" in /etc/logfiles, with the effect that cron.daily will
341 automatically archive, gzip, and empty the log, when it exceeds 1M size.
343 Default: Log to the a file named logfile. Comment out to disable logging.
348 The "jarfile" defines where Junkbuster stores the cookies it intercepts. Note
349 that if you use a "jarfile", it may grow quite large. Default: Don't store
355 If you specify a "trustfile", Junkbuster will only allow access to sites that
356 are named in the trustfile. You can also mark sites as trusted referrers, with
357 the effect that access to untrusted sites will be granted, if a link from a
358 trusted referrer was used. The link target will then be added to the
359 "trustfile". This is a very restrictive feature that typical users most
360 propably want to leave disabled. Default: Disabled, don't use the trust
366 If you use the trust mechanism, it is a good idea to write up some online
367 documentation about your blocking policy and to specify the URL(s) here. They
368 will appear on the page that your users receive when they try to access
369 untrusted content. Use multiple times for multiple URLs. Default: Don't display
370 links on the "untrusted" info page.
372 trust-info-url http://www.your-site.com/why_we_block.html
373 trust-info-url http://www.your-site.com/what_we_allow.html
376 -------------------------------------------------------------------------------
378 Other Configuration Options
380 This part of the configuration file contains options that control how
383 "Admin-address" should be set to the email address of the proxy administrator.
384 It is used in many of the proxy-generated pages. Default: fill@me.in.please.
386 #admin-address fill@me.in.please
389 "Proxy-info-url" can be set to a URL that contains more info about this
390 Junkbuster installation, it's configuration and policies. It is used in many of
391 the proxy-generated pages and its use is highly recommended in multi-user
392 installations, since your users will want to know why certain content is
393 blocked or modified. Default: Don't show a link to online documentation.
395 proxy-info-url http://www.your-site.com/proxy.html
398 "Listen-address" specifies the address and port where Junkbuster will listen
399 for connections from your Web browser. The default is to listen on the
400 localhost port 8000, and this is suitable for most users. (In your web browser,
401 under proxy configuration, list the proxy server as "localhost" and the port as
404 If you already have another service running on port 8000, or if you want to
405 serve requests from other machines (e.g. on your local network) as well, you
406 will need to override the default. The syntax is "listen-address
407 [<ip-address>]:<port>". If you leave out the IP adress, junkbuster will bind to
408 all interfaces (addresses) on your machine and may become reachable from the
409 internet. In that case, consider using access control lists (acl's) (see
412 For example, suppose you are running Junkbuster on a machine which has the
413 address 192.168.0.1 on your local private network (192.168.0.0) and has another
414 outside connection with a different address. You want it to serve requests from
417 listen-address 192.168.0.1:8000
420 If you want it to listen on all addresses (including the outside connection):
425 If you do this, consider using ACLs (see "aclfile" above). Note: you will need
426 to point your browser(s) to the address and port that you have configured here.
427 Default: localhost:8000 (127.0.0.1:8000).
429 The debug option sets the level of debugging information to log in the logfile
430 (and to the console in the Windows version). A debug level of 1 is informative
431 because it will show you each request as it happens. Higher levels of debug are
432 probably only of interest to developers.
434 debug 1 # GPC = show each GET/POST/CONNECT request
435 debug 2 # CONN = show each connection status
436 debug 4 # IO = show I/O status
437 debug 8 # HDR = show header parsing
438 debug 16 # LOG = log all data into the logfile
439 debug 32 # FRC = debug force feature
440 debug 64 # REF = debug regular expression filter
441 debug 128 # = debug fast redirects
442 debug 256 # = debug GIF deanimation
443 debug 512 # CLF = Common Log Format
444 debug 1024 # = debug kill popups
445 debug 4096 # INFO = Startup banner and warnings.
446 debug 8192 # ERROR = Non-fatal errors
449 It is highly recommended that you enable ERROR reporting (debug 8192), at least
450 until the next stable release.
452 The reporting of FATAL errors (i.e. ones which crash JunkBuster) is always on
453 and cannot be disabled.
455 If you want to use CLF (Common Log Format), you should set "debug 512" ONLY, do
456 not enable anything else.
458 Multiple "debug" directives, are OK - they're logical-OR'd together.
460 debug 15 # same as setting the first 4 listed above
467 debug 8192 # Errors - *we highly recommended enabling this*
470 Junkbuster normally uses "multi-threading", a software technique that permits
471 it to handle many different requests simultaneously. In some cases you may wish
472 to disable this -- particularly if you're trying to debug a problem. The
473 "single-threaded" option forces Junkbuster to handle requests sequentially.
474 Default: Multi-threaded mode.
479 "toggle" allows you to temporarily disable all Junkbuster's filtering. Just set
482 The Windows version of Junkbuster puts an icon in the system tray, which allows
483 you to change this option without having to edit this file. If you right-click
484 on that icon (or select the "Options" menu), one choice is "Enable". Clicking
485 on enable toggles Junkbuster on and off. This is useful if you want to
486 temporarily disable Junkbuster, e.g., to access a site that requires cookies
487 which you normally have blocked.
489 "toggle 1" means Junkbuster runs normally, "toggle 0" means that Junkbuster
490 becomes a non-anonymizing non-blocking proxy. Default: 1.
495 For content filtering, i.e. the "+filter" and "+deanimate-gif" actions, it is
496 neccessary that Junkbuster buffers up the entire document body. This can be
497 potentially dangerous, since a server could just keep sending data indefinitely
498 and wait for your RAM to exhaust.
500 The buffer-limit option lets you set the maximum size in Kbytes that each
501 buffer may use. When the documents buffer exceeds this size, it is flushed to
502 the client unfiltered and no further attempt to filter the rest of it is made.
503 Remember that there may multiple threads running, which might require
504 increasing the "buffer-limit" Kbytes each, unless you have enabled
505 "single-threaded" above.
510 To enable the web-based actionsfile editor set enable-edit-actions to 1, or 0
511 to disable. Note that you must have compiled JunkBuster with support for this
512 feature, otherwise this option has no effect. This internal page can be reached
513 at http://ijbswa.sourceforge.net/config/.
515 Security note: If this is enabled, anyone who can use the proxy can edit the
516 actions file, and their changes will affect all users. For shared proxies, you
517 probably want to disable this. Default: enabled.
519 enable-edit-actions 1
522 Allow JunkBuster to be toggled on and off remotely, using your web browser. Set
523 "enable-remote-toggle"to 1 to enable, and 0 to disable. Note that you must have
524 compiled JunkBuster with support for this feature, otherwise this option has no
527 Security note: If this is enabled, anyone who can use the proxy can toggle it
528 on or off, and their changes will affect all users. For shared proxies, you
529 probably want to disable this. Default: enabled.
531 enable-remote-toggle 1
534 -------------------------------------------------------------------------------
536 Access Control List (ACL)
538 Access controls are included at the request of some ISPs and systems
539 administrators, and are not usually needed by individual users. Please note the
540 warnings in the FAQ that this proxy is not intended to be a substitute for a
541 firewall or to encourage anyone to defer addressing basic security weaknesses.
543 If no access settings are specified, the proxy talks to anyone that connects.
544 If any access settings file are specified, then the proxy talks only to IP
545 addresses permitted somewhere in this file and not denied later in this file.
547 Summary -- if using an ACL:
549 Client must have permission to receive service.
551 LAST match in ACL wins.
553 Default behavior is to deny service.
555 The syntax for an entry in the Access Control List is:
557 ACTION SRC_ADDR[/SRC_MASKLEN] [ DST_ADDR[/DST_MASKLEN] ]
560 Where the individual fields are:
562 ACTION = "permit-access" or "deny-access"
564 SRC_ADDR = client hostname or dotted IP address
565 SRC_MASKLEN = number of bits in the subnet mask for the source
567 DST_ADDR = server or forwarder hostname or dotted IP address
568 DST_MASKLEN = number of bits in the subnet mask for the target
571 The field separator (FS) is whitespace (space or tab).
573 IMPORTANT NOTE: If the junkbuster is using a forwarder (see below) or a gateway
574 for a particular destination URL, the DST_ADDR that is examined is the address
575 of the forwarder or the gateway and NOT the address of the ultimate target.
576 This is necessary because it may be impossible for the local Junkbuster to
577 determine the address of the ultimate target (that's often what gateways are
580 Here are a few examples to show how the ACL features work:
582 "localhost" is OK -- no DST_ADDR implies that ALL destination addresses are OK:
584 permit-access localhost
587 A silly example to illustrate permitting any host on the class-C subnet with
588 Junkbuster to go anywhere:
590 permit-access www.junkbusters.com/24
593 Except deny one particular IP address from using it at all:
595 deny-access ident.junkbusters.com
598 You can also specify an explicit network address and subnet mask. Explicit
599 addresses do not have to be resolved to be used.
601 permit-access 207.153.200.0/24
604 A subnet mask of 0 matches anything, so the next line permits everyone.
606 permit-access 0.0.0.0/0
609 Note, you cannot say:
614 to allow all *.org domains. Every IP address listed must resolve fully.
616 An ISP may want to provide a Junkbuster that is accessible by "the world" and
617 yet restrict use of some of their private content to hosts on its internal
618 network (i.e. its own subscribers). Say, for instance the ISP owns the Class-B
619 IP address block 123.124.0.0 (a 16 bit netmask). This is how they could do it:
621 permit-access 0.0.0.0/0 0.0.0.0/0 # other clients can go anywhere
622 # with the following exceptions:
624 deny-access 0.0.0.0/0 123.124.0.0/16 # block all external requests for
625 # sites on the ISP's network
627 permit 0.0.0.0/0 www.my_isp.com # except for the ISP's main
630 permit 123.124.0.0/16 0.0.0.0/0 # the ISP's clients can go
634 Note that if some hostnames are listed with multiple IP addresses, the primary
635 value returned by DNS (via gethostbyname()) is used. Default: Anyone can access
638 -------------------------------------------------------------------------------
642 This feature allows chaining of HTTP requests via multiple proxies. It can be
643 used to better protect privacy and confidentiality when accessing specific
644 domains by routing requests to those domains to a special purpose filtering
645 proxy such as lpwa.com. Or to use a caching proxy to speed up browsing.
647 It can also be used in an environment with multiple networks to route requests
648 via multiple gateways allowing transparent access to multiple networks without
649 having to modify browser configurations.
651 Also specified here are SOCKS proxies. Junkbuster SOCKS 4 and SOCKS 4A. The
652 difference is that SOCKS 4A will resolve the target hostname using DNS on the
653 SOCKS server, not our local DNS client.
655 The syntax of each line is:
657 forward target_domain[:port] http_proxy_host[:port]
658 forward-socks4 target_domain[:port] socks_proxy_host[:port] http_proxy_host[:
660 forward-socks4a target_domain[:port] socks_proxy_host[:port] http_proxy_host[:
664 If http_proxy_host is ".", then requests are not forwarded to a HTTP proxy but
665 are made directly to the web servers.
667 Lines are checked in sequence, and the last match wins.
669 There is an implicit line equivalent to the following, which specifies that
670 anything not finding a match on the list is to go out without forwarding or
671 gateway protocol, like so:
673 forward .* . # implicit
676 In the following common configuration, everything goes to Lucent's LPWA, except
677 SSL on port 443 (which it doesn't handle):
679 forward .* lpwa.com:8000
683 See the FAQ for instructions on how to automate the login procedure for LPWA.
684 Some users have reported difficulties related to LPWA's use of "." as the last
685 element of the domain, and have said that this can be fixed with this:
687 forward lpwa. lpwa.com:8000
690 (NOTE: the syntax for specifiying target_domain has changed since the previous
691 paragraph was written -- it will not work now. More information is welcome.)
693 In this fictitious example, everything goes via an ISP's caching proxy, except
694 requests to that ISP:
696 forward .* caching.myisp.net:8000
700 For the @home network, we're told the forwarding configuration is this:
702 forward .* proxy:8080
705 Also, we're told they insist on getting cookies and JavaScript, so you need to
706 add home.com to the cookie file. We consider JavaScript a security risk. Java
709 In this example direct connections are made to all "internal" domains, but
710 everything else goes through Lucent's LPWA by way of the company's SOCKS
711 gateway to the Internet.
713 forward_socks4 .* lpwa.com:8000 firewall.my_company.com:1080
714 forward my_company.com .
717 This is how you could set up a site that always uses SOCKS but no forwarders:
719 forward_socks4a .* . firewall.my_company.com:1080
722 An advanced example for network administrators:
724 If you have links to multiple ISPs that provide various special content to
725 their subscribers, you can configure forwarding to pass requests to the
726 specific host that's connected to that ISP so that everybody can see all of the
727 content on all of the ISPs.
729 This is a bit tricky, but here's an example:
731 host-a has a PPP connection to isp-a.com. And host-b has a PPP connection to
732 isp-b.com. host-a can run a Junkbuster proxy with forwarding like this:
735 forward isp-b.com host-b:8000
738 host-b can run a Junkbuster proxy with forwarding like this:
741 forward isp-a.com host-a:8000
744 Now, anyone on the Internet (including users on host-a and host-b) can set
745 their browser's proxy to either host-a or host-b and be able to browse the
746 content on isp-a or isp-b.
748 Here's another practical example, for University of Kent at Canterbury students
749 with a network connection in their room, who need to use the University's Squid
752 forward *. ssbcache.ukc.ac.uk:3128 # Use the proxy, except for:
753 forward .ukc.ac.uk . # Anything on the same domain as us
754 forward * . # Host with no domain specified
755 forward 129.12.*.* . # A dotted IP on our /16 network.
756 forward 127.*.*.* . # Loopback address
757 forward localhost.localdomain . # Loopback address
758 forward www.ukc.mirror.ac.uk . # Specific host
761 If you intend to chain Junkbuster and squid locally, then chain as browser ->
762 squid -> junkbuster is the recommended way.
764 Your squid configuration could then look like this:
766 # Define junkbuster as parent cache
768 cache_peer 127.0.0.1 parent 8000 0 no-query
770 # Define ACL for protocol FTP
773 # Do not forward ACL FTP to junkbuster
774 always_direct allow FTP
776 # Do not forward ACL CONNECT (https) to junkbuster
777 always_direct allow CONNECT
779 # Forward the rest to junkbuster
780 never_direct allow all
783 -------------------------------------------------------------------------------
787 Junkbuster has a number of options specific to the Windows GUI interface:
789 If "activity-animation" is set to 1, the Junkbuster icon will animate when
790 "Junkbuster" is active. To turn off, set to 0.
795 If "log-messages" is set to 1, Junkbuster will log messages to the console
801 If "log-buffer-size" is set to 1, the size of the log buffer, i.e. the amount
802 of memory used for the log messages displayed in the console window, will be
803 limited to "log-max-lines" (see below).
805 Warning: Setting this to 0 will result in the buffer to grow infinitely and eat
811 log-max-lines is the maximum number of lines held in the log buffer. See above.
816 If "log-highlight-messages" is set to 1, Junkbuster will highlight portions of
817 the log messages with a bold-faced font:
819 log-highlight-messages 1
822 The font used in the console window:
824 log-font-name Comic Sans MS
827 Font size used in the console window:
832 "show-on-task-bar" controls whether or not Junkbuster will appear as a button
833 on the Task bar when minimized:
838 If "close-button-minimizes" is set to 1, the Windows close button will minimize
839 Junkbuster instead of closing the program (close with the exit option on the
842 close-button-minimizes 1
845 The "hide-console" option is specific to the MS-Win console version of
846 JunkBuster. If this option is used, Junkbuster will disconnect from and hide
852 -------------------------------------------------------------------------------
856 The "actionsfile" is used to define what actions Junkbuster takes, and thus
857 determines how images, cookies and various other aspects of HTTP content and
858 transactions are handled. Images can be anything you want, including ads,
859 banners, or just some obnoxious image that you would rather not see. Cookies
860 can be accepted or rejected. The default file is in fact named actionsfile.
862 To determine which actions apply to a request, the URL of the request is
863 compared to all patterns in this file. Every time it matches, the list of
864 applicable actions for the URL is incrementally updated. You can trace this
865 process by visiting http://i.j.b/show-url-info.
867 There are four types of lines in this file: comments (begin with a "#"
868 character), actions, aliases and patterns, all of which are explained below.
870 -------------------------------------------------------------------------------
872 URL Domain and Path Syntax
874 Generally, a pattern has the form <domain>/<path>, where both the <domain> and
875 <path> part are optional. If you only specify a domain part, the "/" can be
878 www.example.com - is a domain only pattern and will match any request to
881 www.example.com/ - means exactly the same.
883 www.example.com/index.html - matches only the single document "/index.html" on
886 /index.html - matches the document "/index.html", regardless of the domain.
888 index.html - matches nothing, since it would be interpreted as a domain name
889 and there is no top-level domain called ".html".
891 The matching of the domain part offers some flexible options: if the domain
892 starts or ends with a dot, it becomes unanchored at that end. For example:
894 .example.com - matches any domain that ENDS in ".example.com".
896 www. - matches any domain that STARTS with "www".
898 Additionally, there are wildcards that you can use in the domain names
899 themselves. They work pretty similar to shell wildcards: "*" stands for zero or
900 more arbitrary characters, "?" stands for any single character. And you can
901 define charachter classes in square brackets and they can be freely mixed:
903 ad*.example.com - matches "adserver.example.com", "ads.example.com", etc but
904 not "sfads.example.com".
906 *ad*.example.com - matches all of the above, and then some.
908 .?pix.com - matches "www.ipix.com", "pictures.epix.com", "a.b.c.d.e.upix.com",
911 www[1-9a-ez].example.com - matches "www1.example.com", "www4.example.com",
912 "wwwd.example.com", "wwwz.example.com", etc., but not "wwww.example.com".
914 If Junkbuster was compiled with "pcre" support (default), Perl compatible
915 regular expressions can be used. See the pcre/docs/ direcory or "man perlre"
916 (also available on http://www.perldoc.com/perl5.6/pod/perlre.html) for details.
917 A brief discussion of regular expressions is in the Appendix. For instance:
919 /.*/advert[0-9]+\.jpe?g - would match a URL from any domain, with any path that
920 includes "advert" followed immediately by one or more digits, then a "." and
921 ending in either "jpeg" or "jpg". So we match "example.com/ads/advert2.jpg",
922 and "www.example.com/ads/banners/advert39.jpeg", but not "www.example.com/ads/
923 banners/advert39.gif" (no gifs in the example pattern).
925 Please note that matching in the path is case INSENSITIVE by default, but you
926 can switch to case sensitive at any point in the pattern by using the "(?-i)"
929 www.example.com/(?-i)PaTtErN.* - will match only documents whose path starts
930 with "PaTtErN" in exactly this capitalization.
932 -------------------------------------------------------------------------------
936 Actions are enabled if preceded with a "+", and disabled if preceded with a
937 "-". Actions are invoked by enclosing the action name in curly braces (e.g.
938 {+some_action}), followed by a list of URLs to which the action applies. There
939 are three classes of actions:
941 * Boolean (e.g. "+/-block"):
943 {+name} # enable this action
944 {-name} # disable this action
947 * Parameterized (e.g. "+/-hide-user-agent"):
949 {+name{param}} # enable action and set parameter to "param"
950 {-name} # disable action
953 * Multi-value (e.g. "{+/-add-header{Name: value}}", "{+/-wafer{name=value}}
956 {+name{param}} # enable action and add parameter "param"
957 {-name{param}} # remove the parameter "param"
958 {-name} # disable this action totally
961 If nothing is specified in this file, no "actions" are taken. So in this case
962 JunkBuster would just be a normal, non-blocking, non-anonymizing proxy. You
963 must specifically enable the privacy and blocking features you need (although
964 the provided default actionsfile file will give a good starting point).
966 Later defined actions always over-ride earlier ones. For multi-valued actions,
967 the actions are applied in the order they are specified.
969 The list of valid Junkbuster "actions" are:
971 * Add the specified HTTP header, which is not checked for validity. You may
972 specify this many times to specify many different headers:
974 +add-header{Name: value}
977 * Block this URL totally.
982 * De-animate all animated GIF images, i.e. reduce them to their last frame.
983 This will also shrink the images considerably (in bytes, not pixels!). If
984 the option "first" is given, the first frame of the animation is used as
985 the replacement. If "last" is given, the last frame of the animation is
986 used instead, which propably makes more sense for most banner animations,
987 but also has the risk of not showing the entire last frame (if it is only a
988 delta to an earlier frame).
990 +deanimate-gifs{last}
991 +deanimate-gifs{first}
994 * "+downgrade" will downgrade HTTP/1.1 client requests to HTTP/1.0 and
995 downgrade the responses as well. Use this action for servers that use HTTP/
996 1.1 protocol features that Junkbuster doesn't handle well yet. HTTP/1.1 is
997 only partially implemented. Default is not to downgrade requests.
1002 * Many sites, like yahoo.com, don't just link to other sites. Instead, they
1003 will link to some script on their own server, giving the destination as a
1004 parameter, which will then redirect you to the final target. URLs resulting
1005 from this scheme typically look like: http://some.place/some_script?http://
1008 Sometimes, there are even multiple consecutive redirects encoded in the
1009 URL. These redirections via scripts make your web browing more traceable,
1010 since the server from which you follow such a link can see where you go to.
1011 Apart from that, valuable bandwidth and time is wasted, while your browser
1012 ask the server for one redirect after the other. Plus, it feeds the
1015 The "+fast-redirects" option enables interception of these requests by
1016 Junkbuster, who will cut off all but the last valid URL in the request and
1017 send a local redirect back to your browser without contacting the remote
1023 * Filter the website through the re_filterfile:
1028 * Block any existing X-Forwarded-for header, and do not add a new one:
1033 * If the browser sends a "From:" header containing your e-mail address, this
1034 either completely removes the header ("block"), or changes it to the
1035 specified e-mail address.
1038 +hide-from{spam@sittingduck.xqq}
1041 * Don't send the "Referer:" (sic) header to the web site. You can block it,
1042 forge a URL to the same server as the request (which is preferred because
1043 some sites will not send images otherwise) or set it to a constant string
1046 +hide-referer{block}
1047 +hide-referer{forge}
1048 +hide-referer{http://nowhere.com}
1051 * Alternative spelling of "+hide-referer". It has the same parameters, and
1052 can be freely mixed with, "+hide-referer". ("referrer" is the correct
1053 English spelling, however the HTTP specification has a bug - it requires it
1054 to be spelled "referer".)
1059 * Change the "User-Agent:" header so web servers can't tell your browser
1060 type. Warning! This breaks many web sites. Specify the user-agent value you
1061 want. Example, pretend to be using Netscape on Linux:
1063 +hide-user-agent{Mozilla (X11; I; Linux 2.0.32 i586)}
1066 * Treat this URL as an image. This only matters if it's also "+block"ed, in
1067 which case a "blocked" image can be sent rather than a HTML page. See
1068 "+image-blocker{}" below for the control over what is actually sent.
1073 * Decides what to do with URLs that end up tagged with "{+block +image}".
1074 There are 4 options. "-image-blocker" will send a HTML "blocked" page,
1075 usually resulting in a "broken image" icon. "+image-blocker{logo}" will
1076 send a "JunkBuster" image. "+image-blocker{blank}" will send a 1x1
1077 transparent GIF image. And finally, "+image-blocker{http://xyz.com}" will
1078 send a HTTP temporary redirect to the specified image. This has the
1079 advantage of the icon being being cached by the browser, which will speed
1082 +image-blocker{logo}
1083 +image-blocker{blank}
1084 +image-blocker{http://i.j.b/send-banner}
1087 * By default (i.e. in the absence of a "+limit-connect" action), Junkbuster
1088 will only allow CONNECT requests to port 443, which is the standard port
1089 for https as a precaution.
1091 The CONNECT methods exists in HTTP to allow access to secure websites
1092 (https:// URLs) through proxies. It works very simply: the proxy connects
1093 to the server on the specified port, and then short-circuits its
1094 connections to the client and to the remote proxy. This can be a big
1095 security hole, since CONNECT-enabled proxies can be abused as TCP relays
1098 If you want to allow CONNECT for more ports than this, or want to forbid
1099 CONNECT altogether, you can specify a comma separated list of ports and
1100 port ranges (the latter using dashes, with the minimum defaulting to 0 and
1103 +limit-connect{443} # This is the default and need no be specified.
1104 +limit-connect{80,443} # Ports 80 and 443 are OK.
1105 +limit-connect{-3, 7, 20-100, 500-} # Port less than 3, 7, 20 to 100
1106 #and above 500 are OK.
1109 * "+no-compression" prevents the website from compressing the data. Some
1110 websites do this, which can be a problem for Junkbuster, since "+filter",
1111 "+no-popup" and "+gif-deanimate" will not work on compressed data. This
1112 will slow down connections to those websites, though. Default is
1113 "nocompression" is turned on.
1118 * Prevent the website from reading cookies:
1123 * Prevent the website from setting cookies:
1128 * Filter the website through a built-in filter to disable those obnoxious
1129 JavaScript pop-up windows via window.open(), etc. The two alternative
1130 spellings are equivalent.
1136 * This action only applies if you are using a jarfile for saving cookies. It
1137 sends a cookie to every site stating that you do not accept any copyright
1138 on cookies sent to you, and asking them not to track you. Of course, this
1139 is a (relatively) unique header they could use to track you.
1144 * This allows you to add an arbitrary cookie. It can be specified multiple
1145 times in order to add as many cookies as you like.
1150 The meaning of any of the above is reversed by preceding the action with a "-",
1151 in place of the "+".
1155 Turn off cookies by default, then allow a few through for specified sites:
1157 # Turn off all cookies
1158 { +no-cookies-read }
1161 # Execeptions to the above, sites that need cookies
1162 { -no-cookies-read }
1170 # Alternative way of saying the same thing
1171 {-no-cookies-set -no-cookies-read}
1176 Now turn off "fast redirects", and then we allow two exceptions:
1181 # Reverse it for these two sites, which don't work right without it.
1183 www.ukc.ac.uk/cgi-bin/wac\.cgi\?
1187 Turn on page filtering, with one exception for sourceforge:
1189 # Run everything through the default filter file (re_filterfile):
1192 # But please don't re_filter code from sourceforge!
1194 .cvs.sourceforge.net
1197 Now some URLs that we want "blocked", ie we won't see them. Many of these use
1198 regular expressions that will expand to match multiple URLs:
1202 /.*/(.*[-_.])?ads?[0-9]?(/|[-_.].*|\.(gif|jpe?g))
1203 /.*/(.*[-_.])?count(er)?(\.cgi|\.dll|\.exe|[?/])
1204 /.*/(ng)?adclient\.cgi
1205 /.*/(plain|live|rotate)[-_.]?ads?/
1206 /.*/(sponsor)s?[0-9]?/
1207 /.*/_?(plain|live)?ads?(-banners)?/
1209 /.*/ad(sdna_image|gifs?)/
1210 /.*/ad(server|stream|juggler)\.(cgi|pl|dll|exe)
1214 /.*/adv((er)?ts?|ertis(ing|ements?))?/
1218 /.*/cgi-bin/centralad/getimage
1219 /.*/images/addver\.gif
1220 /.*/images/marketing/.*\.(gif|jpe?g)
1224 /.*/sponsors?[0-9]?/
1225 /.*/advert[0-9]+\.jpg
1232 /graphics/defaultAd/
1234 /image\.ng/transactionID
1235 /images/.*/.*_anim\.gif # alvin brattli
1236 /ip_img/.*\.(gif|jpe?g)
1240 /cgi-bin/nph-adclick.exe/
1241 /.*/Image/BannerAdvertising/
1243 /.*/adlib/server\.cgi
1247 -------------------------------------------------------------------------------
1251 Custom "actions", known to Junkbuster as "aliases", can be defined by combining
1252 other "actions". These can in turn be invoked just like the built-in "actions".
1253 Currently, an alias can contain any character except space, tab, "=", "{" or "}
1254 ". But please use only "a"- "z", "0"-"9", "+", and "-". Alias names are not
1255 case sensitive, and must be defined before anything else in actionsfile! And
1256 there can only be one set of "aliases" defined.
1258 Now let's define a few aliases:
1260 # Useful customer aliases we can use later. These must come first!
1262 +no-cookies = +no-cookies-set +no-cookies-read
1263 -no-cookies = -no-cookies-set -no-cookies-read
1265 -block -no-cookies -filter -fast-redirects -hide-referer -no-popups
1266 shop = -no-cookies -filter -fast-redirects
1267 +imageblock = +block +image
1269 #For people who don't like to type too much: ;-)
1272 c2 = -no-cookies-set +no-cookies-read
1273 c3 = +no-cookies-set -no-cookies-read
1274 #... etc. Customize to your heart's content.
1277 Some examples using our "shop" and "fragile" aliases from above:
1279 # These sites are very complex and require
1280 # minimal interference.
1282 .office.microsoft.com
1283 .windowsupdate.microsoft.com
1286 # Shopping sites - still want to block ads.
1289 .worldpay.com # for quietpc.com
1293 # These shops require pop-ups
1299 -------------------------------------------------------------------------------
1303 The filter file defines what filtering of web pages Junkbuster does. The
1304 default filter file is re_filterfile, located in the config directory. In this
1305 file, any document content, whether viewable text or embedded non-visible
1306 content, can be changed.
1308 This file uses regular expressions to alter or remove any string in the target
1309 page. Some examples from the included default re_filterfile:
1311 Stop web pages from displaying annoying messages in the status bar by deleting
1314 # The status bar is for displaying link targets, not pointless buzzwords.
1315 # Again, check it out on http://www.airport-cgn.de/.
1316 s/status='.*?';*//ig
1319 Just for kicks, replace any occurrence of "Microsoft" with "MicroSuck":
1321 s/microsoft(?!.com)/MicroSuck/ig
1324 Kill those auto-refresh tags:
1326 # Kill refresh tags. I like to refresh myself. Manually.
1327 # check it out on http://www.airport-cgn.de/ and go to the arrivals page.
1329 s/<meta[^>]*http-equiv[^>]*refresh.*URL=([^>]*?)"?>/<link rev="x-refresh" href
1331 s/<meta[^>]*http-equiv="?page-enter"?[^>]*content=[^>]*>/<!
1332 --no page enter for me-->/i
1335 -------------------------------------------------------------------------------
1337 Quickstart to Using Junkbuster
1339 Install package, then run and enjoy! Junbuster accepts only one command line
1340 option -- the configuration file to be used. Example Unix startup command:
1343 # /usr/sbin/junkbuster /etc/junkbuster/config &
1347 If no configuration file is specified on the command line, Junkbuster will look
1348 for a file named config in the current directory. Except on Amiga where it will
1349 look for AmiTCP:db/junkbuster/config and Win32 where it will try junkbstr.txt.
1350 If no file is specified on the command line and no default configuration file
1351 can be found, Junkbuster will fail to start.
1353 Be sure your browser is set to use the proxy which is by default at localhost,
1354 port 8000. With Netscape (and Mozilla), this can be set under Edit ->
1355 Preferences -> Advanced -> Proxies -> HTTP Proxy. For Internet Explorer: Tools
1356 > Internet Properties -> Connections -> LAN Setting. Then, check "Use Proxy"
1357 and fill in the appropriate info (Address: localhost, Port: 8000). Include if
1358 HTTPS proxy support too.
1360 The included default configuration files should give a reasonable starting
1361 point, though may be somewhat aggressive in blocking junk. You will probably
1362 want to keep an eye out for sites that require cookies, and add these to
1363 actionsfile as needed. By default, most of these will be blocked until you add
1364 them to the configuration. If you want the browser to handle this instead, you
1365 will need to edit actionsfile and disable this feature. If you use more than
1366 one browser, it would make more sense to let Junkbuster handle this. In which
1367 case, the browser(s) should be set to accept all cookies.
1369 If a particular site shows problems loading properly, try adding it to the
1370 {fragile} section of actionsfile. This will turn off most actions for this
1373 HTTP/1.1 support is not fully implemented. If browsers that support HTTP/1.1
1374 (like Mozilla or recent versions of I.E.) experience problems, you might try to
1375 force HTTP/1.0 compatiblity. For Mozilla, look under Edit -> Preferences ->
1376 Debug -> Networking. Or set the "+downgrade" config option in actionsfile.
1378 After running Junkbuster for a while, you can start to fine tune the
1379 configuration to suit your personal, or site, preferences and requirements.
1380 There are many, many aspects that can be customized. "Actions" (from
1381 actionsfile) can be adjusted by pointing your browser to http://
1382 ijbswa.sourceforge.net/config/, and then follow the link to "edit the actions
1383 list". (This is an internal page and does not require Internet access.)
1385 In fact, various aspects of Junkbuster configuration can be viewed from this
1386 page, including current configuration parameters, source code version numbers,
1387 the browser's request headers, and "actions" that apply to a given URL. In
1388 addition to the actionsfile editor mentioned above, Junkbuster can also be
1389 turned "on" and "off" from this page.
1391 If you encounter problems, please verify it is a Junkbuster bug, by disabling
1392 Junkbuster, and then trying the same page. Also, try another browser if
1393 possible to eliminate browser or site problems. Before reporting it as a bug,
1394 see if there is not a configuration option that is enabled that is causing the
1395 page not to load. You can then add an exception for that page or site. If a
1396 bug, please report it to the developers (see below).
1398 -------------------------------------------------------------------------------
1400 Contact the Developers
1402 Feature requests and other questions should be posted to the Feature request
1403 page at SourceForge. There is also an archive there.
1405 Anyone interested in actively participating in development and related
1406 discussions can join the appropriate mailing list here. Archives are available
1409 Please report bugs, using the form at Sourceforge. Please try to verify that it
1410 is a Junkbuster bug, and not a browser or site bug first. Also, check to make
1411 sure this is not already a known bug.
1413 -------------------------------------------------------------------------------
1415 Copyright and History
1419 Internet Junkbuster is free software; you can redistribute it and/or modify it
1420 under the terms of the GNU General Public License as published by the Free
1421 Software Foundation; either version 2 of the License, or (at your option) any
1424 This program is distributed in the hope that it will be useful, but WITHOUT ANY
1425 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
1426 PARTICULAR PURPOSE. See the GNU General Public License for more details, which
1427 is available from the Free Software Foundation, Inc, 59 Temple Place - Suite
1428 330, Boston, MA 02111-1307, USA.
1430 -------------------------------------------------------------------------------
1434 Junkbuster was originally written by Anonymous Coders and JunkBusters
1435 Corporation, and was released as free open-source software under the GNU GPL.
1436 Stefan Waldherr made many improvements, and started the SourceForge project to
1437 rekindle development. The last stable release was v2.0.2, which has now grown
1440 -------------------------------------------------------------------------------
1444 http://sourceforge.net/projects/ijbswa
1446 http://ijbswa.sourceforge.net/
1448 http://ijbswa.sourceforge.net/config/
1450 http://www.junkbusters.com/ht/en/cookies.html
1452 http://www.waldherr.org/junkbuster/
1454 http://privacy.net/analyze/
1456 http://www.squid-cache.org/
1460 -------------------------------------------------------------------------------
1466 Junkbuster can use "regular expressions" in various config files. Assuming
1467 support for "pcre" (Perl Compatible Regular Expressions) is compiled in, which
1468 is the default. Such configuration directives do not require regular
1469 expressions, but they can be used to increase flexibility by matching a pattern
1470 with wildcards against URLs.
1472 If you are reading this, you probably don't understand what "regular
1473 expressions" are, or what they can do. So this will be a very brief
1474 introduction only. A full explanation would require a book ;-)
1476 "Regular expressions" is a way of matching one character expression against
1477 another to see if it matches or not. One of the "expressions" is a literal
1478 string of readable characters (letter, numbers, etc), and the other is a
1479 complex string of literal characters combined with wildcards, and other special
1480 characters, called metacharacters. The "metacharacters" have special meanings
1481 and are used to build the complex pattern to be matched against. Perl
1482 Compatible Regular Expressions is an enhanced form of the regular expression
1483 language with backward compatibility.
1485 To make a simple analogy, we do something similar when we use wildcard
1486 characters when listing files with the dir command in DOS. *.* matches all
1487 filenames. The "special" character here is the asterik which matches any and
1488 all characters. We can be more specific and use ? to match just individual
1489 characters. So "dir file?.text" would match "file1.txt", "file2.txt", etc. We
1490 are pattern matching, using a similar technique to "regular expressions"!
1492 Regular expressions do essentially the same thing, but are much, much more
1493 powerful. There are many more "special characters" and ways of building complex
1494 patterns however. Let's look at a few of the common ones, and then some
1497 . - Matches any single character, e.g. "a", "A", "4", ":", or "@".
1499 ? - The preceding character or expression is matched ZERO or ONE times. Either/
1502 + - The preceding character or expression is matched ONE or MORE times.
1504 * - The preceding character or expression is matched ZERO or MORE times.
1506 \ - The "escape" character denotes that the following character should be taken
1507 literally. This is used where one of the special characters (e.g. ".") needs to
1508 be taken literally and not as a special metacharacter.
1510 [] - Characters enclosed in brackets will be matched if any of the enclosed
1511 characters are encountered.
1513 () - Pararentheses are used to group a sub-expression, or multiple
1516 | - The "bar" character works like an "or" conditional statement. A match is
1517 successful if the sub-expression on either side of "|" matches.
1519 s/string1/string2/g - This is used to rewrite strings of text. "string1" is
1520 replaced by "string2" in this example.
1522 These are just some of the ones you are likely to use when matching URLs with
1523 Junkbuster, and is a long way from a definitive list. This is enough to get us
1524 started with a few simple examples which may be more illuminating:
1526 /.*/banners/.* - A simple example that uses the common combination of "." and "
1527 *" to denote any character, zero or more times. In other words, any string at
1528 all. So we start with a literal forward slash, then our regular expression
1529 pattern (".*") another literal forward slash, the string "banners", another
1530 forward slash, and lastly another ".*". We are building a directory path here.
1531 This will match any file with the path that has a directory named "banners" in
1532 it. The ".*" matches any characters, and this could conceivably be more forward
1533 slashes, so it might expand into a much longer looking path. For example, this
1534 could match: "/eye/hate/spammers/banners/annoy_me_please.gif", or just "/
1535 banners/annoying.html", or almost an infinite number of other possible
1536 combinations, just so it has "banners" in the path somewhere.
1538 A now something a little more complex:
1540 /.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward
1541 slashes again ("/"), so we are building another expression that is a file path
1542 statement. We have another ".*", so we are matching against any conceivable
1543 sub-path, just so it matches our expression. The only true literal that must
1544 match our pattern is adv, together with the forward slashes. What comes after
1545 the "adv" string is the interesting part.
1547 Remember the "?" means the preceding expression (either a literal character or
1548 anything grouped with "(...)" in this case) can exist or not, since this means
1549 either zero or one match. So "((er)?ts?|ertis(ing|ements?))" is optional, as
1550 are the individual sub-expressions: "(er)", "(ing|ements?)", and the "s". The "
1551 |" means "or". We have two of those. For instance, "(ing|ements?)", can expand
1552 to match either "ing" OR "ements?". What is being done here, is an attempt at
1553 matching as many variations of "advertisement", and similar, as possible. So
1554 this would expand to match just "adv", or "advert", or "adverts", or
1555 "advertising", or "advertisement", or "advertisements". You get the idea. But
1556 it would not match "advertizements" (with a "z"). We could fix that by changing
1557 our regular expression to: "/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/", which
1558 would then match either spelling.
1560 /.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward
1561 slashes. Anything in the square brackets "[]" can be matched. This is using
1562 "0-9" as a shorthand expression to mean any digit one through nine. It is the
1563 same as saying "0123456789". So any digit matches. The "+" means one or more of
1564 the preceding expression must be included. The preceding expression here is
1565 what is in the square brackets -- in this case, any digit one through nine.
1566 Then, at the end, we have a grouping: "(gif|jpe?g)". This includes a "|", so
1567 this needs to match the expression on either side of that bar character also. A
1568 simple "gif" on one side, and the other side will in turn match either "jpeg"
1569 or "jpg", since the "?" means the letter "e" is optional and can be matched
1570 once or not at all. So we are building an expression here to match image GIF or
1571 JPEG type image file. It must include the literal string "advert", then one or
1572 more digits, and a "." (which is now a literal, and not a special character,
1573 since it is escaped with "\"), and lastly either "gif", or "jpeg", or "jpg".
1574 Some possible matches would include: "//advert1.jpg", "/nasty/ads/
1575 advert1234.gif", "/banners/from/hell/advert99.jpg". It would not match
1576 "advert1.gif" (no leading slash), or "/adverts232.jpg" (the expression does not
1577 include an "s"), or "/advert1.jsp" ("jsp" is not in the expression anywhere).
1579 s/microsoft(?!.com)/MicroSuck/i - This is a substitution. "MicroSuck" will
1580 replace any occurence of "microsoft". The "i" at the end of the expression
1581 means ignore case. The "(?!.com)" means the match should fail if "microsoft" is
1582 followed by ".com". In other words, this acts like a "NOT" modifier. In case
1583 this is a hyperlink, we don't want to break it ;-).
1585 We are barely scratching the surface of regular expressions here so that you
1586 can understand the default Junkbuster configuration files, and maybe use this
1587 knowledge to customize your own installation. There is much, much more that can
1588 be done with regular expressions. Now that you know enough to get started, you
1589 can learn more on your own :/
1591 More reading on Perl Compatible Regular expressions: http://www.perldoc.com/
1592 perl5.6/pod/perlre.html