3 By: Junkbuster Developers
5 $Id: user-manual.sgml,v 1.23 2001/12/02 00:20:41 hal9 Exp $
7 The user manual gives the users information on how to install and configure
8 Internet Junkbuster. Internet Junkbuster is an application that provides
9 privacy and security to users of the World Wide Web.
11 You can find the latest version of the user manual at http://
12 ijbswa.sourceforge.net/user-manual/.
14 Feel free to send a note to the developers at <
15 ijbswa-developers@lists.sourceforge.net>.
17 -------------------------------------------------------------------------------
33 3. Junkbuster Configuration
35 3.1. The Main Configuration File
39 4. Quickstart to Using Junkbuster
40 5. Contact the Developers
41 6. Copyright and History
49 8.1. Regular Expressions
53 Internet Junkbuster is a web proxy with advanced filtering capabilities for
54 protecting privacy, filtering web page content, managing cookies, controlling
55 access, and removing ads, banners, pop-ups and other obnoxious Internet Junk.
56 Junkbuster has a very flexible configuration and can be customized to suit
57 individual needs and tastes. Internet Junkbuster has application for both
58 stand-alone systems and multi-user networks.
60 This documentation is included with the current development version of Internet
61 Junkbuster and is incomplete at this point. The most up to date reference for
62 the time being is still the comments in the source files and in the individual
63 configuration files. Development of version 3.0 is currently underway, and
64 includes many significant changes and enhancements over earlier verions. The
65 target release date for stable v3.0 is December 2001.
67 Since this is a development version, some features are in the process of being
68 implemented. This documentation may be slightly out of sync as a result. And
69 there are bugs, though hopefully not many!
71 -------------------------------------------------------------------------------
75 In addition to Junkbuster's traditional features of ad and banner blocking and
76 cookie management, this is a list of new features currently under development:
78 * A browser based configuration utility (WIP at http://i.j.b).
80 * Modularized configuration that will allow for system wide settings, and
81 individual user settings. (not implemented yet)
83 * Blocking of annoying pop-up browser windows (previously available as a
86 * Support for HTTP/1.1 (partially implemented at this point).
88 * Support for Perl Compatible Regular Expressions in the configuration files,
89 and generally a more sophisticated configuration syntax over previous
92 * Web page content filtering.
96 In addition, the configuration is more versatile overall.
98 -------------------------------------------------------------------------------
102 Junkbuster is available as raw source code, or pre-compiled binaries. See the
103 Junkbuster Home Page for current release info. Junkbuster is also available via
104 CVS. This is the recommended approach at this time. But please be aware that
105 CVS is constantly changing, and it may break in mysterious ways.
107 -------------------------------------------------------------------------------
111 For gzipped tar archives, unpack the source:
113 tar xzvf ijb_source_* [.tgz or .tar.gz]
114 cd ijb_source_2.9.9_alpha
117 For retrieving the current CVS sources, you'll need the CVS package installed
118 first. To download CVS source:
120 cvs -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa login
121 cvs -z3 -d:pserver:anonymous@cvs.ijbswa.sourceforge.net:/cvsroot/ijbswa co current
125 This will create a directory named current/, which will contain the source
128 Then, in either case, to build from tarball/CVS source:
130 ./configure (--help to see options)
131 make (the make from gnu, gmake for *BSD)
133 make -n install (to see where all the files will go)
134 make install (to really install)
137 For Redhat and SuSE Linux RPM packages, see below.
139 -------------------------------------------------------------------------------
143 To build Redhat RPM packages, install source as above. Then:
145 autoheader [suggested for CVS source]
146 autoconf [suggested for CVS source]
151 This will create both binary and src RPMs in the usual places. Example:
153 /usr/src/redhat/RPMS/i686/junkbuster-2.9.8-1.i686.rpm
155 /usr/src/redhat/SRPMS/junkbuster-2.9.9-1.src.rpm
157 To install, of course:
159 rpm -Uvv /usr/src/redhat/RPMS/i686/junkbuster-2.9.9-1.i686.rpm
162 This will place the Junkbuster configuration files in /etc/junkbuster/, and log
163 files in /var/log/junkbuster/.
165 -------------------------------------------------------------------------------
169 To build SuSE RPM packages, install source as above. Then:
171 autoheader [suggested for CVS source]
172 autoconf [suggested for CVS source]
177 This will create both binary and src RPMs in the usual places. Example:
179 /usr/src/packages/RPMS/i686/junkbuster-2.9.9-1.i686.rpm
181 /usr/src/packages/SRPMS/junkbuster-2.9.9-1.src.rpm
183 To install, of course:
185 rpm -Uvv /usr/src/packages/RPMS/i686/junkbuster-2.9.9-1.i686.rpm
188 This will place the Junkbuster configuration files in /etc/junkbuster/, and log
189 files in /var/log/junkbuster/.
191 -------------------------------------------------------------------------------
195 The OS/2 version of Junkbuster requires the EMX runtime library to be
196 installed. The EMX runtime library is available on the hobbes OS/2 archive,
197 among many other locations: http://hobbes.nmsu.edu/cgi-bin/h-search?sh=1&button
198 =Search&key=emxrt.zip&stype=all&sort=type&dir=%2Fpub%2Fos2%2Fdev%2Femx%2Fv0.9d
200 Junkbuster is packaged in a WarpIN self- installing archive. The
201 self-installing program will be named depending on the release version,
202 something like: ijbos123.exe. In order to install it, simply run this
203 executable or double-click on its icon and follow the WarpIN installation
204 panels. A shadow of the Junkbuster executable will be placed in your startup
205 folder so it will start automatically whenever OS/2 starts.
207 The directory you choose to install Junkbuster into will contain all of the
210 If you would like to build binary images on OS/2 yourself, you will need a
211 working EMX/GCC environment, plus several Unix-like tools. The Hobbes OS/2
212 archive is a good place to start when building such an environment. A set of
213 Unix-like tools named gnupack is located here: http://hobbes.nmsu.edu/cgi-bin/
214 h-search?sh=1&key=gnupack&stype=all&sort=type&dir=%2Fpub%2Fos2%2Fapps
216 Once you have the source code unpacked as above, you can build the binaries
217 from the current/ directory:
224 -------------------------------------------------------------------------------
228 Click-click. (I need help on this. Not a clue here. Also for configuration
231 -------------------------------------------------------------------------------
235 Some quick notes on other Operating Systems.
237 For FreeBSD (and other *BSDs?), the build will need gmake instead of the
238 included make. gmake is available from http://www.gnu.org. The rest should be
239 the same as above for Linux/Unix.
241 -------------------------------------------------------------------------------
243 3. Junkbuster Configuration
245 For Unix, *BSD and Linux, all configuraton files are located in /etc/junkbuster
246 / by default. For MS Windows and OS/2, these are all in the same directory as
247 the Junkbuster executable. The name and number of configuration files has
248 changed from previous versions, and is subject to change as development
251 The installed defaults provide a reasonable starting point. For the time being,
252 there are only three default configuration files (this will change in time):
254 * The main configuration file is named config on Linux, Unix, BSD, and OS/2,
255 and config.txt on Windows. On Amiga, it is AmiTCP:db/junkbuster/config.
257 * The ijb.action file is used to define various "actions" relating to images,
258 banners, pop-ups, access restrictions, banners and cookies. There is a CGI
259 based editor for this file that can be accessed via http://i.j.b. This is
260 the easiest method of configuring actions. (Still under active
263 * The re_filterfile file can be used to rewrite the raw page content,
264 including text as well as embedded HTML and JavaScript.
266 ijb.action and re_filterfile can use Perl style regular expressions for maximum
267 flexibility. All files use the "#" character to denote a comment. Such lines
268 are not processed by Junkbuster. After making any changes, restart Junkbuster
269 in order for the changes to take effect.
271 While under development, the configuration content is subject to change. The
272 below documentation may not be accurate by the time you read this. Also, what
273 constitutes a "default" setting, may change, so please check all your
274 configuration files on important issues.
276 -------------------------------------------------------------------------------
278 3.1. The Main Configuration File
280 Again, the main configuration file is named config on Linux/Unix/BSD and OS/2,
281 and config.txt on Windows. Configuration lines consist of an initial keyword
282 followed by a list of values, all separated by whitespace (any number of spaces
283 or tabs). For example:
285 blockfile blocklist.ini
288 Indicates that the blockfile is named "blocklist.ini".
290 A "#" indicates a comment. Any part of a line following a "#" is ignored,
291 except if the "#" is preceded by a "\".
293 Thus, by placing a "#" at the start of an existing configuration line, you can
294 make it a comment and it will be treated as if it weren't there. This is called
295 "commenting out" an option and can be useful to turn off features: If you
296 comment out the "logfile" line, junkbuster will not log to a file at all. Watch
297 for the "default:" section in each explanation to see what happens if the
298 option is left unset (or commented out).
300 Long lines can be continued on the next line by using a "\" as the very last
303 There are various aspects of Junkbuster behavior that can be tuned.
305 -------------------------------------------------------------------------------
307 3.1.1. Defining Other Configuration Files
309 Junkbuster can use a number of other files to tell it what ads to block, what
310 cookies to accept, etc. This section of the configuration file tells Junkbuster
311 where to find all those other files.
313 On Windows, Junkbuster looks for these files in the same directory as the
314 executable. On Unix and OS/2, Junkbuster looks for these files in the current
315 working directory. In either case, an absolute path name can be used to avoid
318 When development goes modular and multiuser, the blocker, filter, and per-user
319 config will be stored in subdirectories of "confdir". For now, only confdir/
320 templates is used for storing HTML templates for CGI results.
322 The location of the configuration files:
324 confdir /etc/junkbuster # No trailing /, please.
327 The directory where all logging (i.e. logfile and jarfile) takes place. No
328 trailing "/", please:
330 logdir /var/log/junkbuster
333 Note that all file specifications below are relative to the above two
336 The "ijb.action" file contains patterns to specify the actions to apply to
337 requests for each site. Default: Cookies to and from all destinations are kept
338 only during the current browser session (i.e. they are not saved to disk).
339 Popups are disabled for all sites. All sites are filtered if "re_filterfile"
340 specified. No sites are blocked. An empty image is displayed for filtered ads
341 and other images (formerly "tinygif"). The syntax of this file is explained in
344 actionsfile ijb.action
347 The "re_filterfile" file contains content modification rules. These rules
348 permit powerful changes on the content of Web pages, e.g., you could disable
349 your favourite JavaScript annoyances, rewrite the actual content, or just have
350 some fun replacing "Microsoft" with "MicroSuck" wherever it appears on a Web
351 page. Default: No content modification, or whatever the developers are playing
354 re_filterfile re_filterfile
357 The logfile is where all logging and error messages are written. The logfile
358 can be useful for tracking down a problem with Junkbuster (e.g., it's not
359 blocking an ad you think it should block) but in most cases you probably will
362 Your logfile will grow indefinitely, and you will probably want to periodically
363 remove it. On Unix systems, you can do this with a cron job (see "man cron").
364 For Redhat, a logrotate script has been included.
366 On SuSE Linux systems, you can place a line like "/var/log/junkbuster.* +1024k
367 644 nobody.nogroup" in /etc/logfiles, with the effect that cron.daily will
368 automatically archive, gzip, and empty the log, when it exceeds 1M size.
370 Default: Log to the a file named logfile. Comment out to disable logging.
375 The "jarfile" defines where Junkbuster stores the cookies it intercepts. Note
376 that if you use a "jarfile", it may grow quite large. Default: Don't store
382 If you specify a "trustfile", Junkbuster will only allow access to sites that
383 are named in the trustfile. You can also mark sites as trusted referrers, with
384 the effect that access to untrusted sites will be granted, if a link from a
385 trusted referrer was used. The link target will then be added to the
386 "trustfile". This is a very restrictive feature that typical users most
387 propably want to leave disabled. Default: Disabled, don't use the trust
393 If you use the trust mechanism, it is a good idea to write up some online
394 documentation about your blocking policy and to specify the URL(s) here. They
395 will appear on the page that your users receive when they try to access
396 untrusted content. Use multiple times for multiple URLs. Default: Don't display
397 links on the "untrusted" info page.
399 trust-info-url http://www.your-site.com/why_we_block.html
400 trust-info-url http://www.your-site.com/what_we_allow.html
403 -------------------------------------------------------------------------------
405 3.1.2. Other Configuration Options
407 This part of the configuration file contains options that control how
410 "Admin-address" should be set to the email address of the proxy administrator.
411 It is used in many of the proxy-generated pages. Default: fill@me.in.please.
413 #admin-address fill@me.in.please
416 "Proxy-info-url" can be set to a URL that contains more info about this
417 Junkbuster installation, it's configuration and policies. It is used in many of
418 the proxy-generated pages and its use is highly recommended in multi-user
419 installations, since your users will want to know why certain content is
420 blocked or modified. Default: Don't show a link to online documentation.
422 proxy-info-url http://www.your-site.com/proxy.html
425 "Listen-address" specifies the address and port where Junkbuster will listen
426 for connections from your Web browser. The default is to listen on the
427 localhost port 8000, and this is suitable for most users. (In your web browser,
428 under proxy configuration, list the proxy server as "localhost" and the port as
431 If you already have another service running on port 8000, or if you want to
432 serve requests from other machines (e.g. on your local network) as well, you
433 will need to override the default. The syntax is "listen-address
434 [<ip-address>]:<port>". If you leave out the IP address, junkbuster will bind
435 to all interfaces (addresses) on your machine and may become reachable from the
436 Internet. In that case, consider using access control lists (acl's) (see
437 "aclfile" above), or a firewall.
439 For example, suppose you are running Junkbuster on a machine which has the
440 address 192.168.0.1 on your local private network (192.168.0.0) and has another
441 outside connection with a different address. You want it to serve requests from
444 listen-address 192.168.0.1:8000
447 If you want it to listen on all addresses (including the outside connection):
452 If you do this, consider using ACLs (see "aclfile" above). Note: you will need
453 to point your browser(s) to the address and port that you have configured here.
454 Default: localhost:8000 (127.0.0.1:8000).
456 The debug option sets the level of debugging information to log in the logfile
457 (and to the console in the Windows version). A debug level of 1 is informative
458 because it will show you each request as it happens. Higher levels of debug are
459 probably only of interest to developers.
461 debug 1 # GPC = show each GET/POST/CONNECT request
462 debug 2 # CONN = show each connection status
463 debug 4 # IO = show I/O status
464 debug 8 # HDR = show header parsing
465 debug 16 # LOG = log all data into the logfile
466 debug 32 # FRC = debug force feature
467 debug 64 # REF = debug regular expression filter
468 debug 128 # = debug fast redirects
469 debug 256 # = debug GIF deanimation
470 debug 512 # CLF = Common Log Format
471 debug 1024 # = debug kill popups
472 debug 4096 # INFO = Startup banner and warnings.
473 debug 8192 # ERROR = Non-fatal errors
476 It is highly recommended that you enable ERROR reporting (debug 8192), at least
477 until the next stable release.
479 The reporting of FATAL errors (i.e. ones which crash JunkBuster) is always on
480 and cannot be disabled.
482 If you want to use CLF (Common Log Format), you should set "debug 512" ONLY, do
483 not enable anything else.
485 Multiple "debug" directives, are OK - they're logical-OR'd together.
487 debug 15 # same as setting the first 4 listed above
494 debug 8192 # Errors - *we highly recommended enabling this*
497 Junkbuster normally uses "multi-threading", a software technique that permits
498 it to handle many different requests simultaneously. In some cases you may wish
499 to disable this -- particularly if you're trying to debug a problem. The
500 "single-threaded" option forces Junkbuster to handle requests sequentially.
501 Default: Multi-threaded mode.
506 "toggle" allows you to temporarily disable all Junkbuster's filtering. Just set
509 The Windows version of Junkbuster puts an icon in the system tray, which also
510 allows you to change this option. If you right-click on that icon (or select
511 the "Options" menu), one choice is "Enable". Clicking on enable toggles
512 Junkbuster on and off. This is useful if you want to temporarily disable
513 Junkbuster, e.g., to access a site that requires cookies which you would
514 otherwise have blocked. This can also be toggled via a web browser at the
515 Junkbuster internal address of http://i.j.b on any platform.
517 "toggle 1" means Junkbuster runs normally, "toggle 0" means that Junkbuster
518 becomes a non-anonymizing non-blocking proxy. Default: 1 (on).
523 For content filtering, i.e. the "+filter" and "+deanimate-gif" actions, it is
524 neccessary that Junkbuster buffers the entire document body. This can be
525 potentially dangerous, since a server could just keep sending data indefinitely
526 and wait for your RAM to exhaust. With nasty consequences.
528 The buffer-limit option lets you set the maximum size in Kbytes that each
529 buffer may use. When the documents buffer exceeds this size, it is flushed to
530 the client unfiltered and no further attempt to filter the rest of it is made.
531 Remember that there may multiple threads running, which might require
532 increasing the "buffer-limit" Kbytes each, unless you have enabled
533 "single-threaded" above.
538 To enable the web-based ijb.action file editor set enable-edit-actions to 1, or
539 0 to disable. Note that you must have compiled JunkBuster with support for this
540 feature, otherwise this option has no effect. This internal page can be reached
543 Security note: If this is enabled, anyone who can use the proxy can edit the
544 actions file, and their changes will affect all users. For shared proxies, you
545 probably want to disable this. Default: enabled.
547 enable-edit-actions 1
550 Allow JunkBuster to be toggled on and off remotely, using your web browser. Set
551 "enable-remote-toggle"to 1 to enable, and 0 to disable. Note that you must have
552 compiled JunkBuster with support for this feature, otherwise this option has no
555 Security note: If this is enabled, anyone who can use the proxy can toggle it
556 on or off (see http://i.j.b), and their changes will affect all users. For
557 shared proxies, you probably want to disable this. Default: enabled.
559 enable-remote-toggle 1
562 -------------------------------------------------------------------------------
564 3.1.3. Access Control List (ACL)
566 Access controls are included at the request of some ISPs and systems
567 administrators, and are not usually needed by individual users. Please note the
568 warnings in the FAQ that this proxy is not intended to be a substitute for a
569 firewall or to encourage anyone to defer addressing basic security weaknesses.
571 If no access settings are specified, the proxy talks to anyone that connects.
572 If any access settings file are specified, then the proxy talks only to IP
573 addresses permitted somewhere in this file and not denied later in this file.
575 Summary -- if using an ACL:
577 Client must have permission to receive service.
579 LAST match in ACL wins.
581 Default behavior is to deny service.
583 The syntax for an entry in the Access Control List is:
585 ACTION SRC_ADDR[/SRC_MASKLEN] [ DST_ADDR[/DST_MASKLEN] ]
588 Where the individual fields are:
590 ACTION = "permit-access" or "deny-access"
592 SRC_ADDR = client hostname or dotted IP address
593 SRC_MASKLEN = number of bits in the subnet mask for the source
595 DST_ADDR = server or forwarder hostname or dotted IP address
596 DST_MASKLEN = number of bits in the subnet mask for the target
599 The field separator (FS) is whitespace (space or tab).
601 IMPORTANT NOTE: If the junkbuster is using a forwarder (see below) or a gateway
602 for a particular destination URL, the DST_ADDR that is examined is the address
603 of the forwarder or the gateway and NOT the address of the ultimate target.
604 This is necessary because it may be impossible for the local Junkbuster to
605 determine the address of the ultimate target (that's often what gateways are
608 Here are a few examples to show how the ACL features work:
610 "localhost" is OK -- no DST_ADDR implies that ALL destination addresses are OK:
612 permit-access localhost
615 A silly example to illustrate permitting any host on the class-C subnet with
616 Junkbuster to go anywhere:
618 permit-access www.junkbusters.com/24
621 Except deny one particular IP address from using it at all:
623 deny-access ident.junkbusters.com
626 You can also specify an explicit network address and subnet mask. Explicit
627 addresses do not have to be resolved to be used.
629 permit-access 207.153.200.0/24
632 A subnet mask of 0 matches anything, so the next line permits everyone.
634 permit-access 0.0.0.0/0
637 Note, you cannot say:
642 to allow all *.org domains. Every IP address listed must resolve fully.
644 An ISP may want to provide a Junkbuster that is accessible by "the world" and
645 yet restrict use of some of their private content to hosts on its internal
646 network (i.e. its own subscribers). Say, for instance the ISP owns the Class-B
647 IP address block 123.124.0.0 (a 16 bit netmask). This is how they could do it:
649 permit-access 0.0.0.0/0 0.0.0.0/0 # other clients can go anywhere
650 # with the following exceptions:
652 deny-access 0.0.0.0/0 123.124.0.0/16 # block all external requests for
653 # sites on the ISP's network
655 permit 0.0.0.0/0 www.my_isp.com # except for the ISP's main
658 permit 123.124.0.0/16 0.0.0.0/0 # the ISP's clients can go
662 Note that if some hostnames are listed with multiple IP addresses, the primary
663 value returned by DNS (via gethostbyname()) is used. Default: Anyone can access
666 -------------------------------------------------------------------------------
670 This feature allows chaining of HTTP requests via multiple proxies. It can be
671 used to better protect privacy and confidentiality when accessing specific
672 domains by routing requests to those domains to a special purpose filtering
673 proxy such as lpwa.com. Or to use a caching proxy to speed up browsing.
675 It can also be used in an environment with multiple networks to route requests
676 via multiple gateways allowing transparent access to multiple networks without
677 having to modify browser configurations.
679 Also specified here are SOCKS proxies. Junkbuster SOCKS 4 and SOCKS 4A. The
680 difference is that SOCKS 4A will resolve the target hostname using DNS on the
681 SOCKS server, not our local DNS client.
683 The syntax of each line is:
685 forward target_domain[:port] http_proxy_host[:port]
686 forward-socks4 target_domain[:port] socks_proxy_host[:port] http_proxy_host[:
688 forward-socks4a target_domain[:port] socks_proxy_host[:port] http_proxy_host[:
692 If http_proxy_host is ".", then requests are not forwarded to a HTTP proxy but
693 are made directly to the web servers.
695 Lines are checked in sequence, and the last match wins.
697 There is an implicit line equivalent to the following, which specifies that
698 anything not finding a match on the list is to go out without forwarding or
699 gateway protocol, like so:
701 forward .* . # implicit
704 In the following common configuration, everything goes to Lucent's LPWA, except
705 SSL on port 443 (which it doesn't handle):
707 forward .* lpwa.com:8000
711 See the FAQ for instructions on how to automate the login procedure for LPWA.
712 Some users have reported difficulties related to LPWA's use of "." as the last
713 element of the domain, and have said that this can be fixed with this:
715 forward lpwa. lpwa.com:8000
718 (NOTE: the syntax for specifiying target_domain has changed since the previous
719 paragraph was written -- it will not work now. More information is welcome.)
721 In this fictitious example, everything goes via an ISP's caching proxy, except
722 requests to that ISP:
724 forward .* caching.myisp.net:8000
728 For the @home network, we're told the forwarding configuration is this:
730 forward .* proxy:8080
733 Also, we're told they insist on getting cookies and JavaScript, so you should
734 add home.com to the cookie file. We consider JavaScript a security risk. Java
737 In this example direct connections are made to all "internal" domains, but
738 everything else goes through Lucent's LPWA by way of the company's SOCKS
739 gateway to the Internet.
741 forward-socks4 .* lpwa.com:8000 firewall.my_company.com:1080
742 forward my_company.com .
745 This is how you could set up a site that always uses SOCKS but no forwarders:
747 forward-socks4a .* . firewall.my_company.com:1080
750 An advanced example for network administrators:
752 If you have links to multiple ISPs that provide various special content to
753 their subscribers, you can configure forwarding to pass requests to the
754 specific host that's connected to that ISP so that everybody can see all of the
755 content on all of the ISPs.
757 This is a bit tricky, but here's an example:
759 host-a has a PPP connection to isp-a.com. And host-b has a PPP connection to
760 isp-b.com. host-a can run a Junkbuster proxy with forwarding like this:
763 forward isp-b.com host-b:8000
766 host-b can run a Junkbuster proxy with forwarding like this:
769 forward isp-a.com host-a:8000
772 Now, anyone on the Internet (including users on host-a and host-b) can set
773 their browser's proxy to either host-a or host-b and be able to browse the
774 content on isp-a or isp-b.
776 Here's another practical example, for University of Kent at Canterbury students
777 with a network connection in their room, who need to use the University's Squid
780 forward *. ssbcache.ukc.ac.uk:3128 # Use the proxy, except for:
781 forward .ukc.ac.uk . # Anything on the same domain as us
782 forward * . # Host with no domain specified
783 forward 129.12.*.* . # A dotted IP on our /16 network.
784 forward 127.*.*.* . # Loopback address
785 forward localhost.localdomain . # Loopback address
786 forward www.ukc.mirror.ac.uk . # Specific host
789 If you intend to chain Junkbuster and squid locally, then chain as browser ->
790 squid -> junkbuster is the recommended way.
792 Your squid configuration could then look like this:
794 # Define junkbuster as parent cache
796 cache_peer 127.0.0.1 parent 8000 0 no-query
798 # Define ACL for protocol FTP
801 # Do not forward ACL FTP to junkbuster
802 always_direct allow FTP
804 # Do not forward ACL CONNECT (https) to junkbuster
805 always_direct allow CONNECT
807 # Forward the rest to junkbuster
808 never_direct allow all
811 -------------------------------------------------------------------------------
813 3.1.5. Windows GUI Options
815 Junkbuster has a number of options specific to the Windows GUI interface:
817 If "activity-animation" is set to 1, the Junkbuster icon will animate when
818 "Junkbuster" is active. To turn off, set to 0.
823 If "log-messages" is set to 1, Junkbuster will log messages to the console
829 If "log-buffer-size" is set to 1, the size of the log buffer, i.e. the amount
830 of memory used for the log messages displayed in the console window, will be
831 limited to "log-max-lines" (see below).
833 Warning: Setting this to 0 will result in the buffer to grow infinitely and eat
839 log-max-lines is the maximum number of lines held in the log buffer. See above.
844 If "log-highlight-messages" is set to 1, Junkbuster will highlight portions of
845 the log messages with a bold-faced font:
847 log-highlight-messages 1
850 The font used in the console window:
852 log-font-name Comic Sans MS
855 Font size used in the console window:
860 "show-on-task-bar" controls whether or not Junkbuster will appear as a button
861 on the Task bar when minimized:
866 If "close-button-minimizes" is set to 1, the Windows close button will minimize
867 Junkbuster instead of closing the program (close with the exit option on the
870 close-button-minimizes 1
873 The "hide-console" option is specific to the MS-Win console version of
874 JunkBuster. If this option is used, Junkbuster will disconnect from and hide
880 -------------------------------------------------------------------------------
882 3.2. The Actions File
884 The "ijb.action" file (formerly actionsfile) is used to define what actions
885 Junkbuster takes, and thus determines how images, cookies and various other
886 aspects of HTTP content and transactions are handled. Images can be anything
887 you want, including ads, banners, or just some obnoxious image that you would
888 rather not see. Cookies can be accepted or rejected, or accepted only during
889 the current browser session (i.e. not written to disk).
891 To determine which actions apply to a request, the URL of the request is
892 compared to all patterns in this file. Every time it matches, the list of
893 applicable actions for the URL is incrementally updated. You can trace this
894 process by visiting http://i.j.b/show-url-info.
896 The actions file can be edited with a browser by loading http://i.j.b/, and
897 then select "Edit Actions".
899 There are four types of lines in this file: comments (begin with a "#"
900 character), actions, aliases and patterns, all of which are explained below, as
901 well as the configuration file syntax that Junkbuster understands.
903 -------------------------------------------------------------------------------
905 3.2.1. URL Domain and Path Syntax
907 Generally, a pattern has the form <domain>/<path>, where both the <domain> and
908 <path> part are optional. If you only specify a domain part, the "/" can be
911 www.example.com - is a domain only pattern and will match any request to
914 www.example.com/ - means exactly the same.
916 www.example.com/index.html - matches only the single document "/index.html" on
919 /index.html - matches the document "/index.html", regardless of the domain.
921 index.html - matches nothing, since it would be interpreted as a domain name
922 and there is no top-level domain called ".html".
924 The matching of the domain part offers some flexible options: if the domain
925 starts or ends with a dot, it becomes unanchored at that end. For example:
927 .example.com - matches any domain that ENDS in ".example.com".
929 www. - matches any domain that STARTS with "www".
931 Additionally, there are wildcards that you can use in the domain names
932 themselves. They work pretty similar to shell wildcards: "*" stands for zero or
933 more arbitrary characters, "?" stands for any single character. And you can
934 define charachter classes in square brackets and they can be freely mixed:
936 ad*.example.com - matches "adserver.example.com", "ads.example.com", etc but
937 not "sfads.example.com".
939 *ad*.example.com - matches all of the above, and then some.
941 .?pix.com - matches "www.ipix.com", "pictures.epix.com", "a.b.c.d.e.upix.com",
944 www[1-9a-ez].example.com - matches "www1.example.com", "www4.example.com",
945 "wwwd.example.com", "wwwz.example.com", etc., but not "wwww.example.com".
947 If Junkbuster was compiled with "pcre" support (default), Perl compatible
948 regular expressions can be used. See the pcre/docs/ direcory or "man perlre"
949 (also available on http://www.perldoc.com/perl5.6/pod/perlre.html) for details.
950 A brief discussion of regular expressions is in the Appendix. For instance:
952 /.*/advert[0-9]+\.jpe?g - would match a URL from any domain, with any path that
953 includes "advert" followed immediately by one or more digits, then a "." and
954 ending in either "jpeg" or "jpg". So we match "example.com/ads/advert2.jpg",
955 and "www.example.com/ads/banners/advert39.jpeg", but not "www.example.com/ads/
956 banners/advert39.gif" (no gifs in the example pattern).
958 Please note that matching in the path is case INSENSITIVE by default, but you
959 can switch to case sensitive at any point in the pattern by using the "(?-i)"
962 www.example.com/(?-i)PaTtErN.* - will match only documents whose path starts
963 with "PaTtErN" in exactly this capitalization.
965 -------------------------------------------------------------------------------
969 Actions are enabled if preceded with a "+", and disabled if preceded with a
970 "-". Actions are invoked by enclosing the action name in curly braces (e.g.
971 {+some_action}), followed by a list of URLs to which the action applies. There
972 are three classes of actions:
974 * Boolean (e.g. "+/-block"):
976 {+name} # enable this action
977 {-name} # disable this action
980 * Parameterized (e.g. "+/-hide-user-agent"):
982 {+name{param}} # enable action and set parameter to "param"
983 {-name} # disable action
986 * Multi-value (e.g. "{+/-add-header{Name: value}}", "{+/-wafer{name=value}}
989 {+name{param}} # enable action and add parameter "param"
990 {-name{param}} # remove the parameter "param"
991 {-name} # disable this action totally
994 If nothing is specified in this file, no "actions" are taken. So in this case
995 JunkBuster would just be a normal, non-blocking, non-anonymizing proxy. You
996 must specifically enable the privacy and blocking features you need (although
997 the provided default ijb.action file will give a good starting point).
999 Later defined actions always over-ride earlier ones. For multi-valued actions,
1000 the actions are applied in the order they are specified.
1002 The list of valid Junkbuster "actions" are:
1004 * Add the specified HTTP header, which is not checked for validity. You may
1005 specify this many times to specify many different headers:
1007 +add-header{Name: value}
1010 * Block this URL totally.
1015 * De-animate all animated GIF images, i.e. reduce them to their last frame.
1016 This will also shrink the images considerably (in bytes, not pixels!). If
1017 the option "first" is given, the first frame of the animation is used as
1018 the replacement. If "last" is given, the last frame of the animation is
1019 used instead, which propably makes more sense for most banner animations,
1020 but also has the risk of not showing the entire last frame (if it is only a
1021 delta to an earlier frame).
1023 +deanimate-gifs{last}
1024 +deanimate-gifs{first}
1027 * "+downgrade" will downgrade HTTP/1.1 client requests to HTTP/1.0 and
1028 downgrade the responses as well. Use this action for servers that use HTTP/
1029 1.1 protocol features that Junkbuster doesn't handle well yet. HTTP/1.1 is
1030 only partially implemented. Default is not to downgrade requests.
1035 * Many sites, like yahoo.com, don't just link to other sites. Instead, they
1036 will link to some script on their own server, giving the destination as a
1037 parameter, which will then redirect you to the final target. URLs resulting
1038 from this scheme typically look like: http://some.place/some_script?http://
1041 Sometimes, there are even multiple consecutive redirects encoded in the
1042 URL. These redirections via scripts make your web browing more traceable,
1043 since the server from which you follow such a link can see where you go to.
1044 Apart from that, valuable bandwidth and time is wasted, while your browser
1045 ask the server for one redirect after the other. Plus, it feeds the
1048 The "+fast-redirects" option enables interception of these requests by
1049 Junkbuster, who will cut off all but the last valid URL in the request and
1050 send a local redirect back to your browser without contacting the remote
1056 * Filter the website through the re_filterfile:
1061 * Block any existing X-Forwarded-for header, and do not add a new one:
1066 * If the browser sends a "From:" header containing your e-mail address, this
1067 either completely removes the header ("block"), or changes it to the
1068 specified e-mail address.
1071 +hide-from{spam@sittingduck.xqq}
1074 * Don't send the "Referer:" (sic) header to the web site. You can block it,
1075 forge a URL to the same server as the request (which is preferred because
1076 some sites will not send images otherwise) or set it to a constant string
1079 +hide-referer{block}
1080 +hide-referer{forge}
1081 +hide-referer{http://nowhere.com}
1084 * Alternative spelling of "+hide-referer". It has the same parameters, and
1085 can be freely mixed with, "+hide-referer". ("referrer" is the correct
1086 English spelling, however the HTTP specification has a bug - it requires it
1087 to be spelled "referer".)
1092 * Change the "User-Agent:" header so web servers can't tell your browser
1093 type. Warning! This breaks many web sites. Specify the user-agent value you
1094 want. Example, pretend to be using Netscape on Linux:
1096 +hide-user-agent{Mozilla (X11; I; Linux 2.0.32 i586)}
1099 * Treat this URL as an image. This only matters if it's also "+block"ed, in
1100 which case a "blocked" image can be sent rather than a HTML page. See
1101 "+image-blocker{}" below for the control over what is actually sent.
1106 * Decides what to do with URLs that end up tagged with "{+block +image}".
1107 There are 4 options. "-image-blocker" will send a HTML "blocked" page,
1108 usually resulting in a "broken image" icon. "+image-blocker{logo}" will
1109 send a "JunkBuster" image. "+image-blocker{blank}" will send a 1x1
1110 transparent GIF image. And finally, "+image-blocker{http://xyz.com}" will
1111 send a HTTP temporary redirect to the specified image. This has the
1112 advantage of the icon being being cached by the browser, which will speed
1115 +image-blocker{logo}
1116 +image-blocker{blank}
1117 +image-blocker{http://i.j.b/send-banner}
1120 * By default (i.e. in the absence of a "+limit-connect" action), Junkbuster
1121 will only allow CONNECT requests to port 443, which is the standard port
1122 for https as a precaution.
1124 The CONNECT methods exists in HTTP to allow access to secure websites
1125 (https:// URLs) through proxies. It works very simply: the proxy connects
1126 to the server on the specified port, and then short-circuits its
1127 connections to the client and to the remote proxy. This can be a big
1128 security hole, since CONNECT-enabled proxies can be abused as TCP relays
1131 If you want to allow CONNECT for more ports than this, or want to forbid
1132 CONNECT altogether, you can specify a comma separated list of ports and
1133 port ranges (the latter using dashes, with the minimum defaulting to 0 and
1136 +limit-connect{443} # This is the default and need no be specified.
1137 +limit-connect{80,443} # Ports 80 and 443 are OK.
1138 +limit-connect{-3, 7, 20-100, 500-} # Port less than 3, 7, 20 to 100
1139 #and above 500 are OK.
1142 * "+no-compression" prevents the website from compressing the data. Some
1143 websites do this, which can be a problem for Junkbuster, since "+filter",
1144 "+no-popup" and "+gif-deanimate" will not work on compressed data. This
1145 will slow down connections to those websites, though. Default is
1146 "nocompression" is turned on.
1151 * If the website sets cookies, "no-cookies-keep" will make sure they are
1152 erased when you exit and restart your web browser. This makes profiling
1153 cookies useless, but won't break sites which require cookies so that you
1154 can log in for transactions. Default: on.
1159 * Prevent the website from reading cookies:
1164 * Prevent the website from setting cookies:
1169 * Filter the website through a built-in filter to disable those obnoxious
1170 JavaScript pop-up windows via window.open(), etc. The two alternative
1171 spellings are equivalent.
1177 * This action only applies if you are using a jarfile for saving cookies. It
1178 sends a cookie to every site stating that you do not accept any copyright
1179 on cookies sent to you, and asking them not to track you. Of course, this
1180 is a (relatively) unique header they could use to track you.
1185 * This allows you to add an arbitrary cookie. It can be specified multiple
1186 times in order to add as many cookies as you like.
1191 The meaning of any of the above is reversed by preceding the action with a "-",
1192 in place of the "+".
1196 Turn off cookies by default, then allow a few through for specified sites:
1198 # Turn off all persistant cookies
1199 { +no-cookies-read }
1201 # Allow cookies for this browser session ONLY
1202 { +no-cookies-keep }
1204 # Execeptions to the above, sites that benefit from persistant cookies
1205 { -no-cookies-read }
1207 { -no-cookies-keep }
1214 # Alternative way of saying the same thing
1215 {-no-cookies-set -no-cookies-read -no-cookies-keep}
1220 Now turn off "fast redirects", and then we allow two exceptions:
1225 # Reverse it for these two sites, which don't work right without it.
1227 www.ukc.ac.uk/cgi-bin/wac\.cgi\?
1231 Turn on page filtering, with one exception for sourceforge:
1233 # Run everything through the default filter file (re_filterfile):
1236 # But please don't re_filter code from sourceforge!
1238 .cvs.sourceforge.net
1241 Now some URLs that we want "blocked", ie we won't see them. Many of these use
1242 regular expressions that will expand to match multiple URLs:
1246 /.*/(.*[-_.])?ads?[0-9]?(/|[-_.].*|\.(gif|jpe?g))
1247 /.*/(.*[-_.])?count(er)?(\.cgi|\.dll|\.exe|[?/])
1248 /.*/(ng)?adclient\.cgi
1249 /.*/(plain|live|rotate)[-_.]?ads?/
1250 /.*/(sponsor)s?[0-9]?/
1251 /.*/_?(plain|live)?ads?(-banners)?/
1253 /.*/ad(sdna_image|gifs?)/
1254 /.*/ad(server|stream|juggler)\.(cgi|pl|dll|exe)
1258 /.*/adv((er)?ts?|ertis(ing|ements?))?/
1262 /.*/cgi-bin/centralad/getimage
1263 /.*/images/addver\.gif
1264 /.*/images/marketing/.*\.(gif|jpe?g)
1268 /.*/sponsors?[0-9]?/
1269 /.*/advert[0-9]+\.jpg
1276 /graphics/defaultAd/
1278 /image\.ng/transactionID
1279 /images/.*/.*_anim\.gif # alvin brattli
1280 /ip_img/.*\.(gif|jpe?g)
1284 /cgi-bin/nph-adclick.exe/
1285 /.*/Image/BannerAdvertising/
1287 /.*/adlib/server\.cgi
1291 -------------------------------------------------------------------------------
1295 Custom "actions", known to Junkbuster as "aliases", can be defined by combining
1296 other "actions". These can in turn be invoked just like the built-in "actions".
1297 Currently, an alias can contain any character except space, tab, "=", "{" or "}
1298 ". But please use only "a"- "z", "0"-"9", "+", and "-". Alias names are not
1299 case sensitive, and must be defined before anything else in the ijb.actionfile
1300 ! And there can only be one set of "aliases" defined.
1302 Now let's define a few aliases:
1304 # Useful customer aliases we can use later. These must come first!
1306 +no-cookies = +no-cookies-set +no-cookies-read
1307 -no-cookies = -no-cookies-set -no-cookies-read
1309 -block -no-cookies -filter -fast-redirects -hide-referer -no-popups
1310 shop = -no-cookies -filter -fast-redirects
1311 +imageblock = +block +image
1313 #For people who don't like to type too much: ;-)
1316 c2 = -no-cookies-set +no-cookies-read
1317 c3 = +no-cookies-set -no-cookies-read
1318 #... etc. Customize to your heart's content.
1321 Some examples using our "shop" and "fragile" aliases from above:
1323 # These sites are very complex and require
1324 # minimal interference.
1326 .office.microsoft.com
1327 .windowsupdate.microsoft.com
1330 # Shopping sites - still want to block ads.
1333 .worldpay.com # for quietpc.com
1337 # These shops require pop-ups
1343 -------------------------------------------------------------------------------
1345 3.3. The Filter File
1347 The filter file defines what filtering of web pages Junkbuster does. The
1348 default filter file is re_filterfile, located in the config directory. In this
1349 file, any document content, whether viewable text or embedded non-visible
1350 content, can be changed.
1352 This file uses regular expressions to alter or remove any string in the target
1353 page. Some examples from the included default re_filterfile:
1355 Stop web pages from displaying annoying messages in the status bar by deleting
1358 # The status bar is for displaying link targets, not pointless buzzwords.
1359 # Again, check it out on http://www.airport-cgn.de/.
1360 s/status='.*?';*//ig
1363 Just for kicks, replace any occurrence of "Microsoft" with "MicroSuck":
1365 s/microsoft(?!.com)/MicroSuck/ig
1368 Kill those auto-refresh tags:
1370 # Kill refresh tags. I like to refresh myself. Manually.
1371 # check it out on http://www.airport-cgn.de/ and go to the arrivals page.
1373 s/<meta[^>]*http-equiv[^>]*refresh.*URL=([^>]*?)"?>/<link rev="x-refresh" href
1375 s/<meta[^>]*http-equiv="?page-enter"?[^>]*content=[^>]*>/<!
1376 --no page enter for me-->/i
1379 -------------------------------------------------------------------------------
1381 4. Quickstart to Using Junkbuster
1383 Install package, then run and enjoy! Junbuster accepts only one command line
1384 option -- the configuration file to be used. Example Unix startup command:
1387 # /usr/sbin/junkbuster /etc/junkbuster/config
1391 An init script is provided for SuSE and Redhat.
1393 For for SuSE: /etc/rc.d/junkbuster start
1395 For RedHat: /etc/rc.d/init.d/junkbuster start
1397 If no configuration file is specified on the command line, Junkbuster will look
1398 for a file named config in the current directory. Except on Amiga where it will
1399 look for AmiTCP:db/junkbuster/config and Win32 where it will try config.txt. If
1400 no file is specified on the command line and no default configuration file can
1401 be found, Junkbuster will fail to start.
1403 Be sure your browser is set to use the proxy which is by default at localhost,
1404 port 8000. With Netscape (and Mozilla), this can be set under Edit ->
1405 Preferences -> Advanced -> Proxies -> HTTP Proxy. For Internet Explorer: Tools
1406 > Internet Properties -> Connections -> LAN Setting. Then, check "Use Proxy"
1407 and fill in the appropriate info (Address: localhost, Port: 8000). Include if
1408 HTTPS proxy support too.
1410 The included default configuration files should give a reasonable starting
1411 point, though may be somewhat aggressive in blocking junk. You will probably
1412 want to keep an eye out for sites that require persistant cookies, and add
1413 these to ijb.action as needed. By default, most of these will be accepted only
1414 during the current browser session, until you add them to the configuration. If
1415 you want the browser to handle this instead, you will need to edit ijb.action
1416 and disable this feature. If you use more than one browser, it would make more
1417 sense to let Junkbuster handle this. In which case, the browser(s) should be
1418 set to accept all cookies.
1420 If a particular site shows problems loading properly, try adding it to the
1421 {fragile} section of ijb.action. This will turn off most actions for this site.
1423 HTTP/1.1 support is not fully implemented. If browsers that support HTTP/1.1
1424 (like Mozilla or recent versions of I.E.) experience problems, you might try to
1425 force HTTP/1.0 compatiblity. For Mozilla, look under Edit -> Preferences ->
1426 Debug -> Networking. Or set the "+downgrade" config option in ijb.action.
1428 After running Junkbuster for a while, you can start to fine tune the
1429 configuration to suit your personal, or site, preferences and requirements.
1430 There are many, many aspects that can be customized. "Actions" (as specified in
1431 ijb.action) can be adjusted by pointing your browser to http://i.j.b/, and then
1432 follow the link to "edit the actions list". (This is an internal page and does
1433 not require Internet access.)
1435 In fact, various aspects of Junkbuster configuration can be viewed from this
1436 page, including current configuration parameters, source code version numbers,
1437 the browser's request headers, and "actions" that apply to a given URL. In
1438 addition to the ijb.action file editor mentioned above, Junkbuster can also be
1439 turned "on" and "off" from this page.
1441 If you encounter problems, please verify it is a Junkbuster bug, by disabling
1442 Junkbuster, and then trying the same page. Also, try another browser if
1443 possible to eliminate browser or site problems. Before reporting it as a bug,
1444 see if there is not a configuration option that is enabled that is causing the
1445 page not to load. You can then add an exception for that page or site. If a
1446 bug, please report it to the developers (see below).
1448 -------------------------------------------------------------------------------
1450 5. Contact the Developers
1452 Feature requests and other questions should be posted to the Feature request
1453 page at SourceForge. There is also an archive there.
1455 Anyone interested in actively participating in development and related
1456 discussions can join the appropriate mailing list here. Archives are available
1459 Please report bugs, using the form at Sourceforge. Please try to verify that it
1460 is a Junkbuster bug, and not a browser or site bug first. Also, check to make
1461 sure this is not already a known bug.
1463 -------------------------------------------------------------------------------
1465 6. Copyright and History
1469 Internet Junkbuster is free software; you can redistribute it and/or modify it
1470 under the terms of the GNU General Public License as published by the Free
1471 Software Foundation; either version 2 of the License, or (at your option) any
1474 This program is distributed in the hope that it will be useful, but WITHOUT ANY
1475 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
1476 PARTICULAR PURPOSE. See the GNU General Public License for more details, which
1477 is available from the Free Software Foundation, Inc, 59 Temple Place - Suite
1478 330, Boston, MA 02111-1307, USA.
1480 -------------------------------------------------------------------------------
1484 Junkbuster was originally written by Anonymous Coders and JunkBusters
1485 Corporation, and was released as free open-source software under the GNU GPL.
1486 Stefan Waldherr made many improvements, and started the SourceForge project to
1487 rekindle development. The last stable release was v2.0.2, which has now grown
1490 -------------------------------------------------------------------------------
1494 http://sourceforge.net/projects/ijbswa
1496 http://ijbswa.sourceforge.net/
1500 http://www.junkbusters.com/ht/en/cookies.html
1502 http://www.waldherr.org/junkbuster/
1504 http://privacy.net/analyze/
1506 http://www.squid-cache.org/
1510 -------------------------------------------------------------------------------
1514 8.1. Regular Expressions
1516 Junkbuster can use "regular expressions" in various config files. Assuming
1517 support for "pcre" (Perl Compatible Regular Expressions) is compiled in, which
1518 is the default. Such configuration directives do not require regular
1519 expressions, but they can be used to increase flexibility by matching a pattern
1520 with wildcards against URLs.
1522 If you are reading this, you probably don't understand what "regular
1523 expressions" are, or what they can do. So this will be a very brief
1524 introduction only. A full explanation would require a book ;-)
1526 "Regular expressions" is a way of matching one character expression against
1527 another to see if it matches or not. One of the "expressions" is a literal
1528 string of readable characters (letter, numbers, etc), and the other is a
1529 complex string of literal characters combined with wildcards, and other special
1530 characters, called metacharacters. The "metacharacters" have special meanings
1531 and are used to build the complex pattern to be matched against. Perl
1532 Compatible Regular Expressions is an enhanced form of the regular expression
1533 language with backward compatibility.
1535 To make a simple analogy, we do something similar when we use wildcard
1536 characters when listing files with the dir command in DOS. *.* matches all
1537 filenames. The "special" character here is the asterik which matches any and
1538 all characters. We can be more specific and use ? to match just individual
1539 characters. So "dir file?.text" would match "file1.txt", "file2.txt", etc. We
1540 are pattern matching, using a similar technique to "regular expressions"!
1542 Regular expressions do essentially the same thing, but are much, much more
1543 powerful. There are many more "special characters" and ways of building complex
1544 patterns however. Let's look at a few of the common ones, and then some
1547 . - Matches any single character, e.g. "a", "A", "4", ":", or "@".
1549 ? - The preceding character or expression is matched ZERO or ONE times. Either/
1552 + - The preceding character or expression is matched ONE or MORE times.
1554 * - The preceding character or expression is matched ZERO or MORE times.
1556 \ - The "escape" character denotes that the following character should be taken
1557 literally. This is used where one of the special characters (e.g. ".") needs to
1558 be taken literally and not as a special metacharacter.
1560 [] - Characters enclosed in brackets will be matched if any of the enclosed
1561 characters are encountered.
1563 () - Pararentheses are used to group a sub-expression, or multiple
1566 | - The "bar" character works like an "or" conditional statement. A match is
1567 successful if the sub-expression on either side of "|" matches.
1569 s/string1/string2/g - This is used to rewrite strings of text. "string1" is
1570 replaced by "string2" in this example.
1572 These are just some of the ones you are likely to use when matching URLs with
1573 Junkbuster, and is a long way from a definitive list. This is enough to get us
1574 started with a few simple examples which may be more illuminating:
1576 /.*/banners/.* - A simple example that uses the common combination of "." and "
1577 *" to denote any character, zero or more times. In other words, any string at
1578 all. So we start with a literal forward slash, then our regular expression
1579 pattern (".*") another literal forward slash, the string "banners", another
1580 forward slash, and lastly another ".*". We are building a directory path here.
1581 This will match any file with the path that has a directory named "banners" in
1582 it. The ".*" matches any characters, and this could conceivably be more forward
1583 slashes, so it might expand into a much longer looking path. For example, this
1584 could match: "/eye/hate/spammers/banners/annoy_me_please.gif", or just "/
1585 banners/annoying.html", or almost an infinite number of other possible
1586 combinations, just so it has "banners" in the path somewhere.
1588 A now something a little more complex:
1590 /.*/adv((er)?ts?|ertis(ing|ements?))?/ - We have several literal forward
1591 slashes again ("/"), so we are building another expression that is a file path
1592 statement. We have another ".*", so we are matching against any conceivable
1593 sub-path, just so it matches our expression. The only true literal that must
1594 match our pattern is adv, together with the forward slashes. What comes after
1595 the "adv" string is the interesting part.
1597 Remember the "?" means the preceding expression (either a literal character or
1598 anything grouped with "(...)" in this case) can exist or not, since this means
1599 either zero or one match. So "((er)?ts?|ertis(ing|ements?))" is optional, as
1600 are the individual sub-expressions: "(er)", "(ing|ements?)", and the "s". The "
1601 |" means "or". We have two of those. For instance, "(ing|ements?)", can expand
1602 to match either "ing" OR "ements?". What is being done here, is an attempt at
1603 matching as many variations of "advertisement", and similar, as possible. So
1604 this would expand to match just "adv", or "advert", or "adverts", or
1605 "advertising", or "advertisement", or "advertisements". You get the idea. But
1606 it would not match "advertizements" (with a "z"). We could fix that by changing
1607 our regular expression to: "/.*/adv((er)?ts?|erti(s|z)(ing|ements?))?/", which
1608 would then match either spelling.
1610 /.*/advert[0-9]+\.(gif|jpe?g) - Again another path statement with forward
1611 slashes. Anything in the square brackets "[]" can be matched. This is using
1612 "0-9" as a shorthand expression to mean any digit one through nine. It is the
1613 same as saying "0123456789". So any digit matches. The "+" means one or more of
1614 the preceding expression must be included. The preceding expression here is
1615 what is in the square brackets -- in this case, any digit one through nine.
1616 Then, at the end, we have a grouping: "(gif|jpe?g)". This includes a "|", so
1617 this needs to match the expression on either side of that bar character also. A
1618 simple "gif" on one side, and the other side will in turn match either "jpeg"
1619 or "jpg", since the "?" means the letter "e" is optional and can be matched
1620 once or not at all. So we are building an expression here to match image GIF or
1621 JPEG type image file. It must include the literal string "advert", then one or
1622 more digits, and a "." (which is now a literal, and not a special character,
1623 since it is escaped with "\"), and lastly either "gif", or "jpeg", or "jpg".
1624 Some possible matches would include: "//advert1.jpg", "/nasty/ads/
1625 advert1234.gif", "/banners/from/hell/advert99.jpg". It would not match
1626 "advert1.gif" (no leading slash), or "/adverts232.jpg" (the expression does not
1627 include an "s"), or "/advert1.jsp" ("jsp" is not in the expression anywhere).
1629 s/microsoft(?!.com)/MicroSuck/i - This is a substitution. "MicroSuck" will
1630 replace any occurence of "microsoft". The "i" at the end of the expression
1631 means ignore case. The "(?!.com)" means the match should fail if "microsoft" is
1632 followed by ".com". In other words, this acts like a "NOT" modifier. In case
1633 this is a hyperlink, we don't want to break it ;-).
1635 We are barely scratching the surface of regular expressions here so that you
1636 can understand the default Junkbuster configuration files, and maybe use this
1637 knowledge to customize your own installation. There is much, much more that can
1638 be done with regular expressions. Now that you know enough to get started, you
1639 can learn more on your own :/
1641 More reading on Perl Compatible Regular expressions: http://www.perldoc.com/
1642 perl5.6/pod/perlre.html