Re-commit to solve various last minute issues for charsets, etc.

[privoxy.git] / doc / text / developer-manual.txt

                            Privoxy Developer Manual

   [Copyright[ © 2001-2008 by Privoxy Developers]]

   $Id: developer-manual.sgml,v 2.16 2008/01/19 17:52:38 hal9 Exp $

   The developer manual provides guidance on coding, testing, packaging,
   documentation and other issues of importance to those involved with
   Privoxy development. It is mandatory (and helpful!) reading for anyone who
   wants to join the team. Note that it's currently out of date and may not
   be entirely correct. As always, patches are welcome.

   Please note that this document is constantly evolving. This copy
   represents the state at the release of version 3.0.8. You can find the
   latest version of the this manual at
   http://www.privoxy.org/developer-manual/. Please see the Contact section
   on how to contact the developers.

   --------------------------------------------------------------------------

   Table of Contents

   1. Introduction

                1.1. Quickstart to Privoxy Development

   2. The CVS Repository

                2.1. Access to CVS

                2.2. Branches

                2.3. CVS Commit Guidelines

   3. Documentation Guidelines

                3.1. Quickstart to Docbook and SGML

                3.2. Privoxy Documentation Style

                3.3. Privoxy Custom Entities

   4. Coding Guidelines

                4.1. Introduction

                4.2. Using Comments

                             4.2.1. Comment, Comment, Comment

                             4.2.2. Use blocks for comments

                             4.2.3. Keep Comments on their own line

                             4.2.4. Comment each logical step

                             4.2.5. Comment All Functions Thoroughly

                             4.2.6. Comment at the end of braces if the
                             content is more than one screen length

                4.3. Naming Conventions

                             4.3.1. Variable Names

                             4.3.2. Function Names

                             4.3.3. Header file prototypes

                             4.3.4. Enumerations, and #defines

                             4.3.5. Constants

                4.4. Using Space

                             4.4.1. Put braces on a line by themselves.

                             4.4.2. ALL control statements should have a
                             block

                             4.4.3. Do not belabor/blow-up boolean
                             expressions

                             4.4.4. Use white space freely because it is free

                             4.4.5. Don't use white space around structure
                             operators

                             4.4.6. Make the last brace of a function stand
                             out

                             4.4.7. Use 3 character indentions

                4.5. Initializing

                             4.5.1. Initialize all variables

                4.6. Functions

                             4.6.1. Name functions that return a boolean as a
                             question.

                             4.6.2. Always specify a return type for a
                             function.

                             4.6.3. Minimize function calls when iterating by
                             using variables

                             4.6.4. Pass and Return by Const Reference

                             4.6.5. Pass and Return by Value

                             4.6.6. Names of include files

                             4.6.7. Provide multiple inclusion protection

                             4.6.8. Use `extern "C"` when appropriate

                             4.6.9. Where Possible, Use Forward Struct
                             Declaration Instead of Includes

                4.7. General Coding Practices

                             4.7.1. Turn on warnings

                             4.7.2. Provide a default case for all switch
                             statements

                             4.7.3. Try to avoid falling through cases in a
                             switch statement.

                             4.7.4. Use 'long' or 'short' Instead of 'int'

                             4.7.5. Don't mix size_t and other types

                             4.7.6. Declare each variable and struct on its
                             own line.

                             4.7.7. Use malloc/zalloc sparingly

                             4.7.8. The Programmer Who Uses 'malloc' is
                             Responsible for Ensuring 'free'

                             4.7.9. Add loaders to the `file_list' structure
                             and in order

                             4.7.10. "Uncertain" new code and/or changes to
                             existing code, use FIXME or XXX

                4.8. Addendum: Template for files and function comment
                blocks:

   5. Testing Guidelines

                5.1. Testplan for releases

                5.2. Test reports

   6. Releasing a New Version

                6.1. Version numbers

                6.2. Before the Release: Freeze

                6.3. Building and Releasing the Packages

                             6.3.1. Note on Privoxy Packaging

                             6.3.2. Source Tarball

                             6.3.3. SuSE, Conectiva or Red Hat RPM

                             6.3.4. OS/2

                             6.3.5. Solaris

                             6.3.6. Windows

                             6.3.7. Debian

                             6.3.8. Mac OSX

                             6.3.9. FreeBSD

                             6.3.10. HP-UX 11

                             6.3.11. Amiga OS

                             6.3.12. AIX

                6.4. Uploading and Releasing Your Package

                6.5. After the Release

   7. Update the Webserver

   8. Contacting the developers, Bug Reporting and Feature Requests

                8.1. Get Support

                8.2. Reporting Problems

                             8.2.1. Reporting Ads or Other Configuration
                             Problems

                             8.2.2. Reporting Bugs

                8.3. Request New Features

                8.4. Other

   9. Privoxy Copyright, License and History

                9.1. License

                9.2. History

   10. See also

1. Introduction

   Privoxy, as an heir to Junkbuster, is a Free Software project and the code
   is licensed under the GPL. As such, Privoxy development is potentially
   open to anyone who has the time, knowledge, and desire to contribute in
   any capacity. Our goals are simply to continue the mission, to improve
   Privoxy, and to make it available to as wide an audience as possible.

   One does not have to be a programmer to contribute. Packaging, testing,
   documenting and porting, are all important jobs as well.

   --------------------------------------------------------------------------

  1.1. Quickstart to Privoxy Development

   The first step is to join the developer's mailing list. You can submit
   your ideas, or even better patches. Patches are best submitted to the
   Sourceforge tracker set up for this purpose, but can be sent to the list
   for review too.

   You will also need to have a cvs package installed, which will entail
   having ssh installed as well (which seems to be a requirement of
   SourceForge), in order to access the cvs repository. Having the GNU build
   tools is also going to be important (particularly, autoconf and gmake).

   For the time being (read, this section is under construction), you can
   also refer to the extensive comments in the source code. In fact, reading
   the code is recommended in any case.

   --------------------------------------------------------------------------

2. The CVS Repository

   If you become part of the active development team, you will eventually
   need write access to our holy grail, the CVS repository. One of the team
   members will need to set this up for you. Please read this chapter
   completely before accessing via CVS.

   --------------------------------------------------------------------------

  2.1. Access to CVS

   The project's CVS repository is hosted on SourceForge. Please refer to the
   chapters 6 and 7 in SF's site documentation for the technical access
   details for your operating system. For historical reasons, the CVS server
   is called ijbswa.cvs.sourceforge.net, the repository is called ijbswa, and
   the source tree module is called current.

   --------------------------------------------------------------------------

  2.2. Branches

   Within the CVS repository, there are modules and branches. As mentioned,
   the sources are in the current "module". Other modules are present for
   platform specific issues. There is a webview of the CVS hierarchy at
   http://ijbswa.cvs.sourceforge.net/ijbswa/, which might help with
   visualizing how these pieces fit together.

   Branches are used to fork a sub-development path from the main trunk.
   Within the current module where the sources are, there is always at least
   one "branch" from the main trunk devoted to a stable release series. The
   main trunk is where active development takes place for the next stable
   series (e.g. 3.2.x). So just prior to each stable series (e.g. 3.0.x), a
   branch is created just for stable series releases (e.g. 3.0.0 -> 3.0.1 ->
   3.0.2, etc). Once the initial stable release of any stable branch has
   taken place, this branch is only used for bugfixes, which have had prior
   testing before being committed to CVS. (See Version Numbers below for
   details on versioning.)

   At one time there were two distinct branches: stable and unstable. The
   more drastic changes were to be in the unstable branch. These branches
   have now been merged to minimize time and effort of maintaining two
   branches.

   --------------------------------------------------------------------------

  2.3. CVS Commit Guidelines

   The source tree is the heart of every software project. Every effort must
   be made to ensure that it is readable, compilable and consistent at all
   times. There are differing guidelines for the stable branch and the main
   development trunk, and we ask anyone with CVS access to strictly adhere to
   the following guidelines:

   Basic Guidelines, for all branches:

     * Please don't commit even a small change without testing it thoroughly
       first. When we're close to a public release, ask a fellow developer to
       review your changes.

     * Your commit message should give a concise overview of what you changed
       (no big details) and why you changed it Just check previous messages
       for good examples.

     * Don't use the same message on multiple files, unless it equally
       applies to all those files.

     * If your changes span multiple files, and the code won't recompile
       unless all changes are committed (e.g. when changing the signature of
       a function), then commit all files one after another, without long
       delays in between. If necessary, prepare the commit messages in
       advance.

     * Before changing things on CVS, make sure that your changes are in line
       with the team's general consensus on what should be done.

     * Note that near a major public release, we get more cautious. There is
       always the possibility to submit a patch to the patch tracker instead.

   --------------------------------------------------------------------------

3. Documentation Guidelines

   All formal documents are maintained in Docbook SGML and located in the
   doc/source/* directory. You will need Docbook, the Docbook DTD's and the
   Docbook modular stylesheets (or comparable alternatives), and either jade
   or openjade (recommended) installed in order to build docs from source.
   Currently there is user-manual, FAQ, and, of course this, the
   developer-manual in this format. The README, AUTHORS, INSTALL, privoxy.1
   (man page), and config files are also now maintained as Docbook SGML.
   These files, when built, in the top-level source directory are generated
   files! Also, the Privoxy index.html (and a variation on this file,
   privoxy-index.html, meant for inclusion with doc packages), are maintained
   as SGML as well. DO NOT edit these directly. Edit the SGML source, or
   contact someone involved in the documentation.

   config requires some special handling. The reason it is maintained this
   way is so that the extensive comments in the file mirror those in
   user-manual. But the conversion process requires going from SGML to HTML
   to text to special formatting required for the embedded comments. Some of
   this does not survive so well. Especially some of the examples that are
   longer than 80 characters. The build process for this file outputs to
   config.new, which should be reviewed for errors and mis-formatting. Once
   satisfied that it is correct, then it should be hand copied to config.

   Other, less formal documents (e.g. LICENSE) are maintained as plain text
   files in the top-level source directory.

   Packagers are encouraged to include this documentation. For those without
   the ability to build the docs locally, text versions of each are kept in
   CVS. HTML versions are also being kept in CVS under doc/webserver/*. And
   PDF version are kept in doc/pdf/*.

   Formal documents are built with the Makefile targets of make dok, or
   alternately make redhat-dok. If you have problems, try both. The build
   process uses the document SGML sources in doc/source/*/* to update all
   text files in doc/text/ and to update all HTML documents in
   doc/webserver/.

   Documentation writers should please make sure documents build successfully
   before committing to CVS, if possible.

   How do you update the webserver (i.e. the pages on privoxy.org)?

    1. First, build the docs by running make dok (or alternately make
       redhat-dok). For PDF docs, do make dok-pdf.

    2. Run make webserver which copies all files from doc/webserver to the
       sourceforge webserver via scp.

   Finished docs should be occasionally submitted to CVS
   (doc/webserver/*/*.html) so that those without the ability to build them
   locally, have access to them if needed. This is especially important just
   prior to a new release! Please do this after the $VERSION and other
   release specific data in configure.in has been updated (this is done just
   prior to a new release).

   --------------------------------------------------------------------------

  3.1. Quickstart to Docbook and SGML

   If you are not familiar with SGML, it is a markup language similar to
   HTML. Actually, not a mark up language per se, but a language used to
   define markup languages. In fact, HTML is an SGML application. Both will
   use "tags" to format text and other content. SGML tags can be much more
   varied, and flexible, but do much of the same kinds of things. The tags,
   or "elements", are definable in SGML. There is no set "standards". Since
   we are using Docbook, our tags are those that are defined by Docbook. Much
   of how the finish document is rendered is determined by the "stylesheets".
   The stylesheets determine how each tag gets translated to HTML, or other
   formats.

   Tags in Docbook SGML need to be always "closed". If not, you will likely
   generate errors. Example: <title>My Title</title>. They are also
   case-insensitive, but we strongly suggest using all lower case. This keeps
   compatibility with [Docbook] XML.

   Our documents use "sections" for the most part. Sections will be processed
   into HTML headers (e.g. h1 for sect1). The Docbook stylesheets will use
   these to also generate the Table of Contents for each doc. Our TOC's are
   set to a depth of three. Meaning sect1, sect2, and sect3 will have TOC
   entries, but sect4 will not. Each section requires a <title> element, and
   at least one <para>. There is a limit of five section levels in Docbook,
   but generally three should be sufficient for our purposes.

   Some common elements that you likely will use:

   <para></para>, paragraph delimiter. Most text needs to be within paragraph
   elements (there are some exceptions).
   <emphasis></emphasis>, the stylesheets make this italics.
   <filename></filename>, files and directories.
   <command></command>, command examples.
   <literallayout></literallayout>, like <pre>, more or less.
   <itemizedlist></itemizedlist>, list with bullets.
   <listitem></listitem>, member of the above.
   <screen></screen>, screen output, implies <literallayout>.
   <ulink url="example.com"></ulink>, like HTML <a> tag.
   <quote></quote>, for, doh, quoting text.

   Look at any of the existing docs for examples of all these and more.

   You might also find "Writing Documentation Using DocBook - A Crash Course"
   useful.

   --------------------------------------------------------------------------

  3.2. Privoxy Documentation Style

   It will be easier if everyone follows a similar writing style. This just
   makes it easier to read what someone else has written if it is all done in
   a similar fashion.

   Here it is:

     * All tags should be lower case.

     * Tags delimiting a block of text (even small blocks) should be on their
       own line. Like:

        <para>
         Some text goes here.
        </para>


       Tags marking individual words, or few words, should be in-line:

         Just to <emphasis>emphasize</emphasis>, some text goes here.


     * Tags should be nested and step indented for block text like: (except
       in-line tags)

        <para>
         <itemizedlist>
          <para>
           <listitem>
             Some text goes here in our list example.
            </listitem>
          </para>
         </itemizedlist>
        </para>


       This makes it easier to find the text amongst the tags ;-)
     * Use white space to separate logical divisions within a document, like
       between sections. Running everything together consistently makes it
       harder to read and work on.

     * Do not hesitate to make comments. Comments can either use the
       <comment> element, or the <!-- --> style comment familiar from HTML.
       (Note in Docbook v4.x <comment> is replaced by <remark>.)

     * We have an international audience. Refrain from slang, or English
       idiosyncrasies (too many to list :). Humor also does not translate
       well sometimes.

     * Try to keep overall line lengths in source files to 80 characters or
       less for obvious reasons. This is not always possible, with lengthy
       URLs for instance.

     * Our documents are available in differing formats. Right now, they are
       just plain text, HTML, and PDF, but others are always a future
       possibility. Be careful with URLs (<ulink>), and avoid this mistake:

       My favorite site is <ulink url="http://example.com">here</ulink>.

       This will render as "My favorite site is here", which is not real
       helpful in a text doc. Better like this:

       My favorite site is <ulink
       url="http://example.com">example.com</ulink>.

     * All documents should be spell checked occasionally. aspell can check
       SGML with the -H option. (ispell I think too.)

   --------------------------------------------------------------------------

  3.3. Privoxy Custom Entities

   Privoxy documentation is using a number of customized "entities" to
   facilitate documentation maintenance.

   We are using a set of "boilerplate" files with generic text, that is used
   by multiple docs. This way we can write something once, and use it
   repeatedly without having to re-write the same content over and over
   again. If editing such a file, keep in mind that it should be generic.
   That is the purpose; so it can be used in varying contexts without
   additional modifications.

   We are also using what Docbook calls "internal entities". These are like
   variables in programming. Well, sort of. For instance, we have the
   p-version entity that contains the current Privoxy version string. You are
   strongly encouraged to use these where possible. Some of these obviously
   require re-setting with each release (done by the Makefile). A sampling of
   custom entities are listed below. See any of the main docs for examples.

     * Re- "boilerplate" text entities are defined like:

       <!entity supported SYSTEM "supported.sgml">

       In this example, the contents of the file, supported.sgml is available
       for inclusion anywhere in the doc. To make this happen, just reference
       the now defined entity: &supported; (starts with an ampersand and ends
       with a semi-colon), and the contents will be dumped into the finished
       doc at that point.

     * Commonly used "internal entities":

       p-version: the Privoxy version string, e.g. "3.0.8".
       p-status: the project status, either "alpha", "beta", or "stable".
       p-not-stable: use to conditionally include text in "not stable"
       releases (e.g. "beta").
       p-stable: just the opposite.
       p-text: this doc is only generated as text.

   There are others in various places that are defined for a specific
   purpose. Read the source!

   --------------------------------------------------------------------------

4. Coding Guidelines

  4.1. Introduction

   This set of standards is designed to make our lives easier. It is
   developed with the simple goal of helping us keep the "new and improved
   Privoxy" consistent and reliable. Thus making maintenance easier and
   increasing chances of success of the project.

   And that of course comes back to us as individuals. If we can increase our
   development and product efficiencies then we can solve more of the request
   for changes/improvements and in general feel good about ourselves. ;->

   --------------------------------------------------------------------------

  4.2. Using Comments

    4.2.1. Comment, Comment, Comment

   Explanation:

   Comment as much as possible without commenting the obvious. For example do
   not comment "variable_a is equal to variable_b". Instead explain why
   variable_a should be equal to the variable_b. Just because a person can
   read code does not mean they will understand why or what is being done. A
   reader may spend a lot more time figuring out what is going on when a
   simple comment or explanation would have prevented the extra research.
   Please help your brother IJB'ers out!

   The comments will also help justify the intent of the code. If the comment
   describes something different than what the code is doing then maybe a
   programming error is occurring.

   Example:

   /* if page size greater than 1k ... */
   if ( page_length() > 1024 )
   {
       ... "block" the page up ...
   }

   /* if page size is small, send it in blocks */
   if ( page_length() > 1024 )
   {
       ... "block" the page up ...
   }

   This demonstrates 2 cases of "what not to do".  The first is a
   "syntax comment".  The second is a comment that does not fit what
   is actually being done.

   --------------------------------------------------------------------------

    4.2.2. Use blocks for comments

   Explanation:

   Comments can help or they can clutter. They help when they are
   differentiated from the code they describe. One line comments do not offer
   effective separation between the comment and the code. Block identifiers
   do, by surrounding the code with a clear, definable pattern.

   Example:

   /*********************************************************************
    * This will stand out clearly in your code!
    *********************************************************************/
   if ( this_variable == that_variable )
   {
      do_something_very_important();
   }


   /* unfortunately, this may not */
   if ( this_variable == that_variable )
   {
      do_something_very_important();
   }


   if ( this_variable == that_variable ) /* this may not either */
   {
      do_something_very_important();
   }

   Exception:

   If you are trying to add a small logic comment and do not wish to
   "disrupt" the flow of the code, feel free to use a 1 line comment which is
   NOT on the same line as the code.

   --------------------------------------------------------------------------

    4.2.3. Keep Comments on their own line

   Explanation:

   It goes back to the question of readability. If the comment is on the same
   line as the code it will be harder to read than the comment that is on its
   own line.

   There are three exceptions to this rule, which should be violated freely
   and often: during the definition of variables, at the end of closing
   braces, when used to comment parameters.

   Example:

   /*********************************************************************
    * This will stand out clearly in your code,
    * But the second example won't.
    *********************************************************************/
   if ( this_variable == this_variable )
   {
      do_something_very_important();
   }

   if ( this_variable == this_variable ) /*can you see me?*/
   {
      do_something_very_important(); /*not easily*/
   }


   /*********************************************************************
    * But, the encouraged exceptions:
    *********************************************************************/
   int urls_read     = 0;     /* # of urls read + rejected */
   int urls_rejected = 0;     /* # of urls rejected */

   if ( 1 == X )
   {
      do_something_very_important();
   }


   short do_something_very_important(
      short firstparam,   /* represents something */
      short nextparam     /* represents something else */ )
   {
      ...code here...

   }   /* -END- do_something_very_important */

   --------------------------------------------------------------------------

    4.2.4. Comment each logical step

   Explanation:

   Logical steps should be commented to help others follow the intent of the
   written code and comments will make the code more readable.

   If you have 25 lines of code without a comment, you should probably go
   back into it to see where you forgot to put one.

   Most "for", "while", "do", etc... loops _probably_ need a comment. After
   all, these are usually major logic containers.

   --------------------------------------------------------------------------

    4.2.5. Comment All Functions Thoroughly

   Explanation:

   A reader of the code should be able to look at the comments just prior to
   the beginning of a function and discern the reason for its existence and
   the consequences of using it. The reader should not have to read through
   the code to determine if a given function is safe for a desired use. The
   proper information thoroughly presented at the introduction of a function
   not only saves time for subsequent maintenance or debugging, it more
   importantly aids in code reuse by allowing a user to determine the safety
   and applicability of any function for the problem at hand. As a result of
   such benefits, all functions should contain the information presented in
   the addendum section of this document.

   --------------------------------------------------------------------------

    4.2.6. Comment at the end of braces if the content is more than one screen
    length

   Explanation:

   Each closing brace should be followed on the same line by a comment that
   describes the origination of the brace if the original brace is off of the
   screen, or otherwise far away from the closing brace. This will simplify
   the debugging, maintenance, and readability of the code.

   As a suggestion , use the following flags to make the comment and its
   brace more readable:

   use following a closing brace: } /* -END- if() or while () or etc... */

   Example:

   if ( 1 == X )
   {
      do_something_very_important();
      ...some long list of commands...
   } /* -END- if x is 1 */

   or:

   if ( 1 == X )
   {
      do_something_very_important();
      ...some long list of commands...
   } /* -END- if ( 1 == X ) */

   --------------------------------------------------------------------------

  4.3. Naming Conventions

    4.3.1. Variable Names

   Explanation:

   Use all lowercase, and separate words via an underscore ('_'). Do not
   start an identifier with an underscore. (ANSI C reserves these for use by
   the compiler and system headers.) Do not use identifiers which are
   reserved in ANSI C++. (E.g. template, class, true, false, ...). This is in
   case we ever decide to port Privoxy to C++.

   Example:

   int ms_iis5_hack = 0;

   Instead of:

   int msiis5hack = 0; int msIis5Hack = 0;

   --------------------------------------------------------------------------

    4.3.2. Function Names

   Explanation:

   Use all lowercase, and separate words via an underscore ('_'). Do not
   start an identifier with an underscore. (ANSI C reserves these for use by
   the compiler and system headers.) Do not use identifiers which are
   reserved in ANSI C++. (E.g. template, class, true, false, ...). This is in
   case we ever decide to port Privoxy to C++.

   Example:

   int load_some_file( struct client_state *csp )

   Instead of:

   int loadsomefile( struct client_state *csp )
   int loadSomeFile( struct client_state *csp )

   --------------------------------------------------------------------------

    4.3.3. Header file prototypes

   Explanation:

   Use a descriptive parameter name in the function prototype in header
   files. Use the same parameter name in the header file that you use in the
   c file.

   Example:

   (.h) extern int load_aclfile( struct client_state *csp );
   (.c) int load_aclfile( struct client_state *csp )

   Instead of:

   (.h) extern int load_aclfile( struct client_state * ); or
   (.h) extern int load_aclfile();
   (.c) int load_aclfile( struct client_state *csp )

   --------------------------------------------------------------------------

    4.3.4. Enumerations, and #defines

   Explanation:

   Use all capital letters, with underscores between words. Do not start an
   identifier with an underscore. (ANSI C reserves these for use by the
   compiler and system headers.)

   Example:

   (enumeration) : enum Boolean { FALSE, TRUE };
   (#define) : #define DEFAULT_SIZE 100;

   Note: We have a standard naming scheme for #defines that toggle a feature
   in the preprocessor: FEATURE_>, where > is a short (preferably 1 or 2
   word) description.

   Example:

   #define FEATURE_FORCE 1

   #ifdef FEATURE_FORCE
   #define FORCE_PREFIX blah
   #endif /* def FEATURE_FORCE */

   --------------------------------------------------------------------------

    4.3.5. Constants

   Explanation:

   Spell common words out entirely (do not remove vowels).

   Use only widely-known domain acronyms and abbreviations. Capitalize all
   letters of an acronym.

   Use underscore (_) to separate adjacent acronyms and abbreviations. Never
   terminate a name with an underscore.

   Example:

   #define USE_IMAGE_LIST 1

   Instead of:

   #define USE_IMG_LST 1 or
   #define _USE_IMAGE_LIST 1 or
   #define USE_IMAGE_LIST_ 1 or
   #define use_image_list 1 or
   #define UseImageList 1

   --------------------------------------------------------------------------

  4.4. Using Space

    4.4.1. Put braces on a line by themselves.

   Explanation:

   The brace needs to be on a line all by itself, not at the end of the
   statement. Curly braces should line up with the construct that they're
   associated with. This practice makes it easier to identify the opening and
   closing braces for a block.

   Example:

   if ( this == that )
   {
      ...
   }

   Instead of:

   if ( this == that ) { ... }

   or

   if ( this == that ) { ... }

   Note: In the special case that the if-statement is inside a loop, and it
   is trivial, i.e. it tests for a condition that is obvious from the purpose
   of the block, one-liners as above may optically preserve the loop
   structure and make it easier to read.

   Status: developer-discretion.

   Example exception:

   while ( more lines are read )
   {
      /* Please document what is/is not a comment line here */
      if ( it's a comment ) continue;

      do_something( line );
   }

   --------------------------------------------------------------------------

    4.4.2. ALL control statements should have a block

   Explanation:

   Using braces to make a block will make your code more readable and less
   prone to error. All control statements should have a block defined.

   Example:

   if ( this == that )
   {
      do_something();
      do_something_else();
   }

   Instead of:

   if ( this == that ) do_something(); do_something_else();

   or

   if ( this == that ) do_something();

   Note: The first example in "Instead of" will execute in a manner other
   than that which the developer desired (per indentation). Using code braces
   would have prevented this "feature". The "explanation" and "exception"
   from the point above also applies.

   --------------------------------------------------------------------------

    4.4.3. Do not belabor/blow-up boolean expressions

   Example:

   structure->flag = ( condition );

   Instead of:

   if ( condition ) { structure->flag = 1; } else { structure->flag = 0; }

   Note: The former is readable and concise. The later is wordy and
   inefficient. Please assume that any developer new to the project has at
   least a "good" knowledge of C/C++. (Hope I do not offend by that last
   comment ... 8-)

   --------------------------------------------------------------------------

    4.4.4. Use white space freely because it is free

   Explanation:

   Make it readable. The notable exception to using white space freely is
   listed in the next guideline.

   Example:

   int first_value   = 0;
   int some_value    = 0;
   int another_value = 0;
   int this_variable = 0;

   if ( this_variable == this_variable )

   first_value = old_value + ( ( some_value - another_value ) - whatever )

   --------------------------------------------------------------------------

    4.4.5. Don't use white space around structure operators

   Explanation:

   - structure pointer operator ( "->" ) - member operator ( "." ) -
   functions and parentheses

   It is a general coding practice to put pointers, references, and function
   parentheses next to names. With spaces, the connection between the object
   and variable/function name is not as clear.

   Example:

   a_struct->a_member;
   a_struct.a_member;
   function_name();

   Instead of: a_struct -> a_member; a_struct . a_member; function_name ();

   --------------------------------------------------------------------------

    4.4.6. Make the last brace of a function stand out

   Example:

   int function1( ... )
   {
      ...code...
      return( ret_code );

   }   /* -END- function1 */


   int function2( ... )
   {
   }   /* -END- function2 */

   Instead of:

   int function1( ... ) { ...code... return( ret_code ); } int function2( ...
   ) { }

   Note: Use 1 blank line before the closing brace and 2 lines afterward.
   This makes the end of function standout to the most casual viewer.
   Although function comments help separate functions, this is still a good
   coding practice. In fact, I follow these rules when using blocks in "for",
   "while", "do" loops, and long if {} statements too. After all whitespace
   is free!

   Status: developer-discretion on the number of blank lines. Enforced is the
   end of function comments.

   --------------------------------------------------------------------------

    4.4.7. Use 3 character indentions

   Explanation:

   If some use 8 character TABs and some use 3 character TABs, the code can
   look *very* ragged. So use 3 character indentions only. If you like to use
   TABs, pass your code through a filter such as "expand -t3" before checking
   in your code.

   Example:

   static const char * const url_code_map[256] =
   {
      NULL, ...
   };


   int function1( ... )
   {
      if ( 1 )
      {
         return( ALWAYS_TRUE );
      }
      else
      {
         return( HOW_DID_YOU_GET_HERE );
      }

      return( NEVER_GETS_HERE );

   }

   --------------------------------------------------------------------------

  4.5. Initializing

    4.5.1. Initialize all variables

   Explanation:

   Do not assume that the variables declared will not be used until after
   they have been assigned a value somewhere else in the code. Remove the
   chance of accidentally using an unassigned variable.

   Example:

   short a_short = 0;
   float a_float  = 0;
   struct *ptr = NULL;

   Note: It is much easier to debug a SIGSEGV if the message says you are
   trying to access memory address 00000000 and not 129FA012; or
   array_ptr[20] causes a SIGSEV vs. array_ptr[0].

   Status: developer-discretion if and only if the variable is assigned a
   value "shortly after" declaration.

   --------------------------------------------------------------------------

  4.6. Functions

    4.6.1. Name functions that return a boolean as a question.

   Explanation:

   Value should be phrased as a question that would logically be answered as
   a true or false statement

   Example:

   should_we_block_this();
   contains_an_image();
   is_web_page_blank();

   --------------------------------------------------------------------------

    4.6.2. Always specify a return type for a function.

   Explanation:

   The default return for a function is an int. To avoid ambiguity, create a
   return for a function when the return has a purpose, and create a void
   return type if the function does not need to return anything.

   --------------------------------------------------------------------------

    4.6.3. Minimize function calls when iterating by using variables

   Explanation:

   It is easy to write the following code, and a clear argument can be made
   that the code is easy to understand:

   Example:

   for ( size_t cnt = 0; cnt < block_list_length(); cnt++ )
   {
      ....
   }

   Note: Unfortunately, this makes a function call for each and every
   iteration. This increases the overhead in the program, because the
   compiler has to look up the function each time, call it, and return a
   value. Depending on what occurs in the block_list_length() call, it might
   even be creating and destroying structures with each iteration, even
   though in each case it is comparing "cnt" to the same value, over and
   over. Remember too - even a call to block_list_length() is a function
   call, with the same overhead.

   Instead of using a function call during the iterations, assign the value
   to a variable, and evaluate using the variable.

   Example:

   size_t len = block_list_length();

   for ( size_t cnt = 0; cnt < len; cnt++ )
   {
      ....
   }

   Exceptions: if the value of block_list_length() *may* change or could
   *potentially* change, then you must code the function call in the
   for/while loop.

   --------------------------------------------------------------------------

    4.6.4. Pass and Return by Const Reference

   Explanation:

   This allows a developer to define a const pointer and call your function.
   If your function does not have the const keyword, we may not be able to
   use your function. Consider strcmp, if it were defined as: extern int
   strcmp( char *s1, char *s2 );

   I could then not use it to compare argv's in main: int main( int argc,
   const char *argv[] ) { strcmp( argv[0], "privoxy" ); }

   Both these pointers are *const*! If the c runtime library maintainers do
   it, we should too.

   --------------------------------------------------------------------------

    4.6.5. Pass and Return by Value

   Explanation:

   Most structures cannot fit onto a normal stack entry (i.e. they are not 4
   bytes or less). Aka, a function declaration like: int load_aclfile( struct
   client_state csp )

   would not work. So, to be consistent, we should declare all prototypes
   with "pass by value": int load_aclfile( struct client_state *csp )

   --------------------------------------------------------------------------

    4.6.6. Names of include files

   Explanation:

   Your include statements should contain the file name without a path. The
   path should be listed in the Makefile, using -I as processor directive to
   search the indicated paths. An exception to this would be for some
   proprietary software that utilizes a partial path to distinguish their
   header files from system or other header files.

   Example:

   #include <iostream.h>     /* This is not a local include */
   #include "config.h"       /* This IS a local include */

   Exception:

   /* This is not a local include, but requires a path element. */
   #include <sys/fileName.h>

   Note: Please! do not add "-I." to the Makefile without a _very_ good
   reason. This duplicates the #include "file.h" behavior.

   --------------------------------------------------------------------------

    4.6.7. Provide multiple inclusion protection

   Explanation:

   Prevents compiler and linker errors resulting from redefinition of items.

   Wrap each header file with the following syntax to prevent multiple
   inclusions of the file. Of course, replace PROJECT_H with your file name,
   with "." Changed to "_", and make it uppercase.

   Example:

   #ifndef PROJECT_H_INCLUDED
   #define PROJECT_H_INCLUDED
    ...
   #endif /* ndef PROJECT_H_INCLUDED */

   --------------------------------------------------------------------------

    4.6.8. Use `extern "C"` when appropriate

   Explanation:

   If our headers are included from C++, they must declare our functions as
   `extern "C"`. This has no cost in C, but increases the potential
   re-usability of our code.

   Example:

   #ifdef __cplusplus
   extern "C"
   {
   #endif /* def __cplusplus */

   ... function definitions here ...

   #ifdef __cplusplus
   }
   #endif /* def __cplusplus */

   --------------------------------------------------------------------------

    4.6.9. Where Possible, Use Forward Struct Declaration Instead of Includes

   Explanation:

   Useful in headers that include pointers to other struct's. Modifications
   to excess header files may cause needless compiles.

   Example:

   /*********************************************************************
    * We're avoiding an include statement here!
    *********************************************************************/
   struct file_list;
   extern file_list *xyz;

   Note: If you declare "file_list xyz;" (without the pointer), then
   including the proper header file is necessary. If you only want to
   prototype a pointer, however, the header file is unnecessary.

   Status: Use with discretion.

   --------------------------------------------------------------------------

  4.7. General Coding Practices

    4.7.1. Turn on warnings

   Explanation

   Compiler warnings are meant to help you find bugs. You should turn on as
   many as possible. With GCC, the switch is "-Wall". Try and fix as many
   warnings as possible.

   --------------------------------------------------------------------------

    4.7.2. Provide a default case for all switch statements

   Explanation:

   What you think is guaranteed is never really guaranteed. The value that
   you don't think you need to check is the one that someday will be passed.
   So, to protect yourself from the unknown, always have a default step in a
   switch statement.

   Example:

   switch( hash_string( cmd ) )
   {
      case hash_actions_file :
         ... code ...
         break;

      case hash_confdir :
         ... code ...
         break;

      default :
         log_error( ... );
         ... anomaly code goes here ...
         continue; / break; / exit( 1 ); / etc ...

   } /* end switch( hash_string( cmd ) ) */

   Note: If you already have a default condition, you are obviously exempt
   from this point. Of note, most of the WIN32 code calls `DefWindowProc'
   after the switch statement. This API call *should* be included in a
   default statement.

   Another Note: This is not so much a readability issue as a robust
   programming issue. The "anomaly code goes here" may be no more than a
   print to the STDERR stream (as in load_config). Or it may really be an
   abort condition.

   Status: Programmer discretion is advised.

   --------------------------------------------------------------------------

    4.7.3. Try to avoid falling through cases in a switch statement.

   Explanation:

   In general, you will want to have a 'break' statement within each 'case'
   of a switch statement. This allows for the code to be more readable and
   understandable, and furthermore can prevent unwanted surprises if someone
   else later gets creative and moves the code around.

   The language allows you to plan the fall through from one case statement
   to another simply by omitting the break statement within the case
   statement. This feature does have benefits, but should only be used in
   rare cases. In general, use a break statement for each case statement.

   If you choose to allow fall through, you should comment both the fact of
   the fall through and reason why you felt it was necessary.

   --------------------------------------------------------------------------

    4.7.4. Use 'long' or 'short' Instead of 'int'

   Explanation:

   On 32-bit platforms, int usually has the range of long. On 16-bit
   platforms, int has the range of short.

   Status: open-to-debate. In the case of most FSF projects (including
   X/GNU-Emacs), there are typedefs to int4, int8, int16, (or equivalence ...
   I forget the exact typedefs now). Should we add these to IJB now that we
   have a "configure" script?

   --------------------------------------------------------------------------

    4.7.5. Don't mix size_t and other types

   Explanation:

   The type of size_t varies across platforms. Do not make assumptions about
   whether it is signed or unsigned, or about how long it is. Do not compare
   a size_t against another variable of a different type (or even against a
   constant) without casting one of the values.

   --------------------------------------------------------------------------

    4.7.6. Declare each variable and struct on its own line.

   Explanation:

   It can be tempting to declare a series of variables all on one line.
   Don't.

   Example:

   long a = 0;
   long b = 0;
   long c = 0;

   Instead of:

   long a, b, c;

   Explanation: - there is more room for comments on the individual variables
   - easier to add new variables without messing up the original ones - when
   searching on a variable to find its type, there is less clutter to
   "visually" eliminate

   Exceptions: when you want to declare a bunch of loop variables or other
   trivial variables; feel free to declare them on one line. You should,
   although, provide a good comment on their functions.

   Status: developer-discretion.

   --------------------------------------------------------------------------

    4.7.7. Use malloc/zalloc sparingly

   Explanation:

   Create a local struct (on the stack) if the variable will live and die
   within the context of one function call.

   Only "malloc" a struct (on the heap) if the variable's life will extend
   beyond the context of one function call.

   Example:

   If a function creates a struct and stores a pointer to it in a
   list, then it should definitely be allocated via `malloc'.

   --------------------------------------------------------------------------

    4.7.8. The Programmer Who Uses 'malloc' is Responsible for Ensuring 'free'

   Explanation:

   If you have to "malloc" an instance, you are responsible for insuring that
   the instance is `free'd, even if the deallocation event falls within some
   other programmer's code. You are also responsible for ensuring that
   deletion is timely (i.e. not too soon, not too late). This is known as
   "low-coupling" and is a "good thing (tm)". You may need to offer a
   free/unload/destructor type function to accommodate this.

   Example:

   int load_re_filterfile( struct client_state *csp ) { ... }
   static void unload_re_filterfile( void *f ) { ... }

   Exceptions:

   The developer cannot be expected to provide `free'ing functions for C
   run-time library functions ... such as `strdup'.

   Status: developer-discretion. The "main" use of this standard is for
   allocating and freeing data structures (complex or nested).

   --------------------------------------------------------------------------

    4.7.9. Add loaders to the `file_list' structure and in order

   Explanation:

   I have ordered all of the "blocker" file code to be in alpha order. It is
   easier to add/read new blockers when you expect a certain order.

   Note: It may appear that the alpha order is broken in places by POPUP
   tests coming before PCRS tests. But since POPUPs can also be referred to
   as KILLPOPUPs, it is clear that it should come first.

   --------------------------------------------------------------------------

    4.7.10. "Uncertain" new code and/or changes to existing code, use FIXME or
    XXX

   Explanation:

   If you have enough confidence in new code or confidence in your changes,
   but are not *quite* sure of the repercussions, add this:

   /* FIXME: this code has a logic error on platform XYZ, * attempting to fix
   */ #ifdef PLATFORM ...changed code here... #endif

   or:

   /* FIXME: I think the original author really meant this... */ ...changed
   code here...

   or:

   /* FIXME: new code that *may* break something else... */ ...new code
   here...

   Note: If you make it clear that this may or may not be a "good thing
   (tm)", it will be easier to identify and include in the project (or
   conversely exclude from the project).

   --------------------------------------------------------------------------

  4.8. Addendum: Template for files and function comment blocks:

   Example for file comments:

const char FILENAME_rcs[] = "$Id: developer-manual.sgml,v 2.16 2008/01/19 17:52:38 hal9 Exp $";
/*********************************************************************
 *
 * File        :  $Source$
 *
 * Purpose     :  (Fill me in with a good description!)
 *
 * Copyright   :  Written by and Copyright (C) 2001-2007 the SourceForge
 *                Privoxy team. http://www.privoxy.org/
 *
 *                Based on the Internet Junkbuster originally written
 *                by and Copyright (C) 1997 Anonymous Coders and
 *                Junkbusters Corporation.  http://www.junkbusters.com
 *
 *                This program is free software; you can redistribute it
 *                and/or modify it under the terms of the GNU General
 *                Public License as published by the Free Software
 *                Foundation; either version 2 of the License, or (at
 *                your option) any later version.
 *
 *                This program is distributed in the hope that it will
 *                be useful, but WITHOUT ANY WARRANTY; without even the
 *                implied warranty of MERCHANTABILITY or FITNESS FOR A
 *                PARTICULAR PURPOSE.  See the GNU General Public
 *                License for more details.
 *
 *                The GNU General Public License should be included with
 *                this file.  If not, you can view it at
 *                http://www.gnu.org/copyleft/gpl.html
 *                or write to the Free Software Foundation, Inc.,
 *                51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 ,
 *                USA
 *
 * Revisions   :
 *    $Log$
 *
 *********************************************************************/


#include "config.h"

   ...necessary include files for us to do our work...

const char FILENAME_h_rcs[] = FILENAME_H_VERSION;

   Note: This declares the rcs variables that should be added to the
   "show-proxy-args" page. If this is a brand new creation by you, you are
   free to change the "Copyright" section to represent the rights you wish to
   maintain.

   Note: The formfeed character that is present right after the comment
   flower box is handy for (X|GNU)Emacs users to skip the verbiage and get to
   the heart of the code (via `forward-page' and `backward-page'). Please
   include it if you can.

   Example for file header comments:

#ifndef _FILENAME_H
#define _FILENAME_H
#define FILENAME_H_VERSION "$Id: developer-manual.sgml,v 2.16 2008/01/19 17:52:38 hal9 Exp $"
/*********************************************************************
 *
 * File        :  $Source$
 *
 * Purpose     :  (Fill me in with a good description!)
 *
 * Copyright   :  Written by and Copyright (C) 2001-2007 the SourceForge
 *                Privoxy team. http://www.privoxy.org/
 *
 *                Based on the Internet Junkbuster originally written
 *                by and Copyright (C) 1997 Anonymous Coders and
 *                Junkbusters Corporation.  http://www.junkbusters.com
 *
 *                This program is free software; you can redistribute it
 *                and/or modify it under the terms of the GNU General
 *                Public License as published by the Free Software
 *                Foundation; either version 2 of the License, or (at
 *                your option) any later version.
 *
 *                This program is distributed in the hope that it will
 *                be useful, but WITHOUT ANY WARRANTY; without even the
 *                implied warranty of MERCHANTABILITY or FITNESS FOR A
 *                PARTICULAR PURPOSE.  See the GNU General Public
 *                License for more details.
 *
 *                The GNU General Public License should be included with
 *                this file.  If not, you can view it at
 *                http://www.gnu.org/copyleft/gpl.html
 *                or write to the Free Software Foundation, Inc.,
 *                51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 ,
 *                USA
 *
 * Revisions   :
 *    $Log$
 *
 *********************************************************************/


#include "project.h"

#ifdef __cplusplus
extern "C" {
#endif

   ... function headers here ...


/* Revision control strings from this header and associated .c file */
extern const char FILENAME_rcs[];
extern const char FILENAME_h_rcs[];


#ifdef __cplusplus
} /* extern "C" */
#endif

#endif /* ndef _FILENAME_H */

/*
  Local Variables:
  tab-width: 3
  end:
*/

   Example for function comments:

   /*********************************************************************
    *
    * Function    :  FUNCTION_NAME
    *
    * Description :  (Fill me in with a good description!)
    *
    * parameters  :
    *          1  :  param1 = pointer to an important thing
    *          2  :  x      = pointer to something else
    *
    * Returns     :  0 => Ok, everything else is an error.
    *
    *********************************************************************/
   int FUNCTION_NAME( void *param1, const char *x )
   {
      ...
      return( 0 );

   }

   Note: If we all follow this practice, we should be able to parse our code
   to create a "self-documenting" web page.

   --------------------------------------------------------------------------

5. Testing Guidelines

   To be filled.

   --------------------------------------------------------------------------

  5.1. Testplan for releases

   Explain release numbers. major, minor. developer releases. etc.

    1. Remove any existing rpm with rpm -e

    2. Remove any file that was left over. This includes (but is not limited
       to)

          * /var/log/privoxy

          * /etc/privoxy

          * /usr/sbin/privoxy

          * /etc/init.d/privoxy

          * /usr/doc/privoxy*

    3. Install the rpm. Any error messages?

    4. start,stop,status Privoxy with the specific script (e.g.
       /etc/rc.d/init/privoxy stop). Reboot your machine. Does autostart
       work?

    5. Start browsing. Does Privoxy work? Logfile written?

    6. Remove the rpm. Any error messages? All files removed?

   --------------------------------------------------------------------------

  5.2. Test reports

   Please submit test reports only with the test form at sourceforge. Three
   simple steps:

     * Select category: the distribution you test on.

     * Select group: the version of Privoxy that we are about to release.

     * Fill the Summary and Detailed Description with something intelligent
       (keep it short and precise).

   Do not mail to the mailing list (we cannot keep track on issues there).

   --------------------------------------------------------------------------

6. Releasing a New Version

   When we release versions of Privoxy, our work leaves our cozy secret lab
   and has to work in the cold RealWorld[tm]. Once it is released, there is
   no way to call it back, so it is very important that great care is taken
   to ensure that everything runs fine, and not to introduce problems in the
   very last minute.

   So when releasing a new version, please adhere exactly to the procedure
   outlined in this chapter.

   The following programs are required to follow this process: ncftpput
   (ncftp), scp, ssh (ssh), gmake (GNU's version of make), autoconf, cvs.

   --------------------------------------------------------------------------

  6.1. Version numbers

   First you need to determine which version number the release will have.
   Privoxy version numbers consist of three numbers, separated by dots, like
   in X.Y.Z (e.g. 3.0.0), where:

     * X, the version major, is rarely ever changed. It is increased by one
       if turning a development branch into stable substantially changes the
       functionality, user interface or configuration syntax. Majors 1 and 2
       were Junkbuster, and 3 will be the first stable Privoxy release.

     * Y, the version minor, represents the branch within the major version.
       At any point in time, there are two branches being maintained: The
       stable branch, with an even minor, say, 2N, in which no functionality
       is being added and only bug-fixes are made, and 2N+1, the development
       branch, in which the further development of Privoxy takes place. This
       enables us to turn the code upside down and inside out, while at the
       same time providing and maintaining a stable version. The minor is
       reset to zero (and one) when the major is incremented. When a
       development branch has matured to the point where it can be turned
       into stable, the old stable branch 2N is given up (i.e. no longer
       maintained), the former development branch 2N+1 becomes the new stable
       branch 2N+2, and a new development branch 2N+3 is opened.

     * Z, the point or sub version, represents a release of the software
       within a branch. It is therefore incremented immediately before each
       code freeze. In development branches, only the even point versions
       correspond to actual releases, while the odd ones denote the evolving
       state of the sources on CVS in between. It follows that Z is odd on
       CVS in development branches most of the time. There, it gets increased
       to an even number immediately before a code freeze, and is increased
       to an odd number again immediately thereafter. This ensures that
       builds from CVS snapshots are easily distinguished from released
       versions. The point version is reset to zero when the minor changes.

       Stable branches work a little differently, since there should be
       little to no development happening in such branches. Remember, only
       bugfixes, which presumably should have had some testing before being
       committed. Stable branches will then have their version reported as
       0.0.0, during that period between releases when changes are being
       added. This is to denote that this code is not for release. Then as
       the release nears, the version is bumped according: e.g. 3.0.1 ->
       0.0.0 -> 3.0.2.

   In summary, the main CVS trunk is the development branch where new
   features are being worked on for the next stable series. This should
   almost always be where the most activity takes place. There is always at
   least one stable branch from the trunk, e.g now it is 3.0, which is only
   used to release stable versions. Once the initial *.0 release of the
   stable branch has been done, then as a rule, only bugfixes that have had
   prior testing should be committed to the stable branch. Once there are
   enough bugfixes to justify a new release, the version of this branch is
   again incremented Example: 3.0.0 -> 3.0.1 -> 3.0.2, etc are all stable
   releases from within the stable branch. 3.1.x is currently the main trunk,
   and where work on 3.2.x is taking place. If any questions, please post to
   the devel list before committing to a stable branch!

   Developers should remember too that if they commit a bugfix to the stable
   branch, this will more than likely require a separate submission to the
   main trunk, since these are separate development trees within CVS. If you
   are working on both, then this would require at least two separate check
   outs (i.e main trunk, and the stable release branch, which is v_3_0_branch
   at the moment).

   --------------------------------------------------------------------------

  6.2. Before the Release: Freeze

   The following must be done by one of the developers prior to each new
   release.

     * Make sure that everybody who has worked on the code in the last couple
       of days has had a chance to yell "no!" in case they have pending
       changes/fixes in their pipelines. Announce the freeze so that nobody
       will interfere with last minute changes.

     * Increment the version number (point from odd to even in development
       branches!) in configure.in. (RPM spec files will need to be
       incremented as well.)

     * If default.action has changed since last release (i.e. software
       release or standalone actions file release), bump up its version info
       to A.B in this line:

         {+add-header{X-Actions-File-Version: A.B} -filter -no-popups}

       Then change the version info in doc/webserver/actions/index.php, line:
       '$required_actions_file_version = "A.B";'

     * All documentation should be rebuild after the version bump. Finished
       docs should be then be committed to CVS (for those without the ability
       to build these). Some docs may require rather obscure processing
       tools. config, the man page (and the html version of the man page),
       and the PDF docs fall in this category. REAMDE, the man page, AUTHORS,
       and config should all also be committed to CVS for other packagers.
       The formal docs should be uploaded to the webserver. See the Section
       "Updating the webserver" in this manual for details.

     * The User Manual is also used for context sensitive help for the CGI
       editor. This is version sensitive, so that the user will get
       appropriate help for his/her release. So with each release a fresh
       version should be uploaded to the webserver (this is in addition to
       the main User Manual link from the main page since we need to keep
       manuals for various versions available). The CGI pages will link to
       something like http://privoxy.org/$(VERSION)/user-manual/. This will
       need to be updated for each new release. There is no Makefile target
       for this at this time!!! It needs to be done manually.

     * All developers should look at the ChangeLog and make sure noteworthy
       changes are referenced.

     * Commit all files that were changed in the above steps!

     * Tag all files in CVS with the version number with "cvs tag v_X_Y_Z".
       Don't use vX_Y_Z, ver_X_Y_Z, v_X.Y.Z (won't work) etc.

     * If the release was in a development branch, increase the point version
       from even to odd (X.Y.(Z+1)) again in configure.in and commit your
       change.

     * On the webserver, copy the user manual to a new top-level directory
       called X.Y.Z. This ensures that help links from the CGI pages, which
       have the version as a prefix, will go into the right version of the
       manual. If this is a development branch release, also symlink
       X.Y.(Z-1) to X.Y.Z and X.Y.(Z+1) to . (i.e. dot).

   --------------------------------------------------------------------------

  6.3. Building and Releasing the Packages

   Now the individual packages can be built and released. Note that for GPL
   reasons the first package to be released is always the source tarball.

   For all types of packages, including the source tarball, you must make
   sure that you build from clean sources by exporting the right version from
   CVS into an empty directory (just press return when asked for a password):

  mkdir dist # delete or choose different name if it already exists
  cd dist
  cvs -d:pserver:anonymous@ijbswa.cvs.sourceforge.net:/cvsroot/ijbswa login
  cvs -z3 -d:pserver:anonymous@ijbswa.cvs.sourceforge.net:/cvsroot/ijbswa export -r v_X_Y_Z current

   Do NOT change a single bit, including, but not limited to version
   information after export from CVS. This is to make sure that all release
   packages, and with them, all future bug reports, are based on exactly the
   same code.

   +------------------------------------------------------------------------+
   |                                Warning                                 |
   |------------------------------------------------------------------------|
   | Every significant release of Privoxy has included at least one package |
   | that either had incorrect versions of files, missing files, or         |
   | incidental leftovers from a previous build process that gave unknown   |
   | numbers of users headaches to try to figure out what was wrong.        |
   | PLEASE, make sure you are using pristene sources, and are following    |
   | the prescribed process!                                                |
   +------------------------------------------------------------------------+

   Please find additional instructions for the source tarball and the
   individual platform dependent binary packages below. And details on the
   Sourceforge release process below that.

   --------------------------------------------------------------------------

    6.3.1. Note on Privoxy Packaging

   Please keep these general guidelines in mind when putting together your
   package. These apply to all platforms!

     * Privoxy requires write access to: all *.action files, all logfiles,
       and the trust file. You will need to determine the best way to do this
       for your platform.

     * Please include up to date documentation. At a bare minimum:

       LICENSE (top-level directory)

       README (top-level directory)

       AUTHORS (top-level directory)

       man page (top-level directory, Unix-like platforms only)

       The User Manual (doc/webserver/user-manual/)

       FAQ (doc/webserver/faq/)

       Also suggested: Developer Manual (doc/webserver/developer-manual) and
       ChangeLog (top-level directory). FAQ and the manuals are HTML docs.
       There are also text versions in doc/text/ which could conceivably also
       be included.

       The documentation has been designed such that the manuals are linked
       to each other from parallel directories, and should be packaged that
       way. privoxy-index.html can also be included and can serve as a focal
       point for docs and other links of interest (and possibly renamed to
       index.html). This should be one level up from the manuals. There is a
       link also on this page to an HTMLized version of the man page. To
       avoid 404 for this, it is in CVS as
       doc/webserver/man-page/privoxy-man-page.html, and should be included
       along with the manuals. There is also a css stylesheets that can be
       included for better presentation: p_doc.css. This should be in the
       same directory with privoxy-index.html, (i.e. one level up from the
       manual directories).

     * user.action and user.filter are designed for local preferences. Make
       sure these do not get overwritten! config should not be overwritten
       either. This has especially important configuration data in it. trust
       should be left in tact as well.

     * Other configuration files (default.action, default.filter and
       standard.action) should be installed as the new defaults, but all
       previously installed configuration files should be preserved as
       backups. This is just good manners :-) These files are likely to
       change between releases and contain important new features and bug
       fixes.

     * Please check platform specific notes in this doc, if you haven't done
       "Privoxy" packaging before for other platform specific issues.
       Conversely, please add any notes that you know are important for your
       platform (or contact one of the doc maintainers to do this if you
       can't).

     * Packagers should do a "clean" install of their package after building
       it. So any previous installs should be removed first to ensure the
       integrity of the newly built package. Then run the package for a while
       to make sure there are no obvious problems, before uploading.

   --------------------------------------------------------------------------

    6.3.2. Source Tarball

   First, make sure that you have freshly exported the right version into an
   empty directory. (See "Building and releasing packages" above). Then run:

     cd current
     autoheader && autoconf && ./configure

   Then do:

     make tarball-dist

   To upload the package to Sourceforge, simply issue

     make tarball-upload

   Go to the displayed URL and release the file publicly on Sourceforge. For
   the change log field, use the relevant section of the ChangeLog file.

   --------------------------------------------------------------------------

    6.3.3. SuSE, Conectiva or Red Hat RPM

   In following text, replace dist with either "rh" for Red Hat or "suse" for
   SuSE.

   First, make sure that you have freshly exported the right version into an
   empty directory. (See "Building and releasing packages" above).

   As the only exception to not changing anything after export from CVS, now
   examine the file privoxy-dist.spec and make sure that the version
   information and the RPM release number are correct. The RPM release
   numbers for each version start at one. Hence it must be reset to one if
   this is the first RPM for dist which is built from version X.Y.Z. Check
   the file list if unsure. Else, it must be set to the highest already
   available RPM release number for that version plus one.

   Then run:

     cd current
     autoheader && autoconf && ./configure

   Then do

     make dist-dist

   To upload the package to Sourceforge, simply issue

     make dist-upload rpm_packagerev

   where rpm_packagerev is the RPM release number as determined above. Go to
   the displayed URL and release the file publicly on Sourceforge. Use the
   release notes and change log from the source tarball package.

   --------------------------------------------------------------------------

    6.3.4. OS/2

   First, make sure that you have freshly exported the right version into an
   empty directory. (See "Building and releasing packages" above). Then get
   the OS/2 Setup module:

  cvs -z3 -d:pserver:anonymous@ijbswa.cvs.sourceforge.net:/cvsroot/ijbswa co os2setup

   You will need a mix of development tools. The main compilation takes place
   with IBM Visual Age C++. Some ancillary work takes place with GNU tools,
   available from various sources like hobbes.nmsu.edu. Specificially, you
   will need autoheader, autoconf and sh tools. The packaging takes place
   with WarpIN, available from various sources, including its home page:
   xworkplace.

   Change directory to the os2setup directory. Edit the os2build.cmd file to
   set the final executable filename. For example,

     installExeName='privoxyos2_setup_X.Y.Z.exe'

   Next, edit the IJB.wis file so the release number matches in the PACKAGEID
   section:

     PACKAGEID="Privoxy Team\Privoxy\Privoxy Package\X\Y\Z"

   You're now ready to build. Run:

     os2build

   You will find the WarpIN-installable executable in the ./files directory.
   Upload this anonymously to uploads.sourceforge.net/incoming, create a
   release for it, and you're done. Use the release notes and Change Log from
   the source tarball package.

   --------------------------------------------------------------------------

    6.3.5. Solaris

   Login to Sourceforge's compilefarm via ssh:

     ssh cf.sourceforge.net

   Choose the right operating system (not the Debian one). When logged in,
   make sure that you have freshly exported the right version into an empty
   directory. (See "Building and releasing packages" above). Then run:

     cd current
     autoheader && autoconf && ./configure

   Then run

     gmake solaris-dist

   which creates a gzip'ed tar archive. Sadly, you cannot use make
   solaris-upload on the Sourceforge machine (no ncftpput). You now have to
   manually upload the archive to Sourceforge's ftp server and release the
   file publicly. Use the release notes and Change Log from the source
   tarball package.

   --------------------------------------------------------------------------

    6.3.6. Windows

   You should ensure you have the latest version of Cygwin (from
   http://www.cygwin.com/). Run the following commands from within a Cygwin
   bash shell.

   First, make sure that you have freshly exported the right version into an
   empty directory. (See "Building and releasing packages" above). Then get
   the Windows setup module:

  cvs -z3  -d:pserver:anonymous@ijbswa.cvs.sourceforge.net:/cvsroot/ijbswa co winsetup

   Then you can build the package. This is fully automated, and is controlled
   by winsetup/GNUmakefile. All you need to do is:

     cd winsetup
     make

   Now you can manually rename privoxy_setup.exe to privoxy_setup_X_Y_Z.exe,
   and upload it to SourceForge. When releasing the package on SourceForge,
   use the release notes and Change Log from the source tarball package.

   --------------------------------------------------------------------------

    6.3.7. Debian

   First, make sure that you have freshly exported the right version into an
   empty directory. (See "Building and releasing packages" above). Then add a
   log entry to debian/changelog, if it is not already there, for example by
   running:

     debchange -v 3.0.8-stable-1 "New upstream version"

   Then, run:

     dpkg-buildpackage -rfakeroot -us -uc -b

   This will create ../privoxy_3.0.8-stable-1_i386.deb which can be uploaded.
   To upload the package to Sourceforge, simply issue

     make debian-upload

   --------------------------------------------------------------------------

    6.3.8. Mac OSX

   First, make sure that you have freshly exported the right version into an
   empty directory. (See "Building and releasing packages" above). Then get
   the Mac OSX setup module:

  cvs -z3 -d:pserver:anonymous@ijbswa.cvs.sourceforge.net:/cvsroot/ijbswa co osxsetup

   Then run:

     cd osxsetup
     build

   This will run autoheader, autoconf and configure as well as make. Finally,
   it will copy over the necessary files to the ./osxsetup/files directory
   for further processing by PackageMaker.

   Bring up PackageMaker with the PrivoxyPackage.pmsp definition file, modify
   the package name to match the release, and hit the "Create package"
   button. If you specify ./Privoxy.pkg as the output package name, you can
   then create the distributable zip file with the command:

     zip -r privoxyosx_setup_x.y.z.zip Privoxy.pkg

   You can then upload privoxyosx_setup_x.y.z.zip anonymously to
   uploads.sourceforge.net/incoming, create a release for it, and you're
   done. Use the release notes and Change Log from the source tarball
   package.

   --------------------------------------------------------------------------

    6.3.9. FreeBSD

   Login to Sourceforge's compile-farm via ssh:

     ssh cf.sourceforge.net

   Choose the right operating system. When logged in, make sure that you have
   freshly exported the right version into an empty directory. (See "Building
   and releasing packages" above). Then run:

     cd current
     autoheader && autoconf && ./configure

   Then run:

     gmake freebsd-dist

   which creates a gzip'ed tar archive. Sadly, you cannot use make
   freebsd-upload on the Sourceforge machine (no ncftpput). You now have to
   manually upload the archive to Sourceforge's ftp server and release the
   file publicly. Use the release notes and Change Log from the source
   tarball package.

   --------------------------------------------------------------------------

    6.3.10. HP-UX 11

   First, make sure that you have freshly exported the right version into an
   empty directory. (See "Building and releasing packages" above). Then run:

     cd current
     autoheader && autoconf && ./configure

   Then do FIXME.

   --------------------------------------------------------------------------

    6.3.11. Amiga OS

   First, make sure that you have freshly exported the right version into an
   empty directory. (See "Building and releasing packages" above). Then run:

     cd current
     autoheader && autoconf && ./configure

   Then do FIXME.

   --------------------------------------------------------------------------

    6.3.12. AIX

   Login to Sourceforge's compilefarm via ssh:

     ssh cf.sourceforge.net

   Choose the right operating system. When logged in, make sure that you have
   freshly exported the right version into an empty directory. (See "Building
   and releasing packages" above). Then run:

     cd current
     autoheader && autoconf && ./configure

   Then run:

     make aix-dist

   which creates a gzip'ed tar archive. Sadly, you cannot use make aix-upload
   on the Sourceforge machine (no ncftpput). You now have to manually upload
   the archive to Sourceforge's ftp server and release the file publicly. Use
   the release notes and Change Log from the source tarball package.

   --------------------------------------------------------------------------

  6.4. Uploading and Releasing Your Package

   After the package is ready, it is time to upload it to SourceForge, and go
   through the release steps. The upload is done via FTP:

     * Upload to: ftp://upload.sourceforge.net/incoming

     * user: anonymous

     * password: ijbswa-developers@lists.sourceforge.net

   Or use the make targets as described above.

   Once this done go to
   http://sourceforge.net/project/admin/editpackages.php?group_id=11118,
   making sure you are logged in. Find your target platform in the second
   column, and click Add Release. You will then need to create a new release
   for your package, using the format of $VERSION ($CODE_STATUS), e.g. 3.0.8
   (beta).

   Now just follow the prompts. Be sure to add any appropriate Release notes.
   You should see your freshly uploaded packages in "Step 2. Add Files To
   This Release". Check the appropriate box(es). Remember at each step to hit
   the "Refresh/Submit" buttons! You should now see your file(s) listed in
   Step 3. Fill out the forms with the appropriate information for your
   platform, being sure to hit "Update" for each file. If anyone is
   monitoring your platform, check the "email" box at the very bottom to
   notify them of the new package. This should do it!

   If you have made errors, or need to make changes, you can go through
   essentially the same steps, but select Edit Release, instead of Add
   Release.

   --------------------------------------------------------------------------

  6.5. After the Release

   When all (or: most of the) packages have been uploaded and made available,
   send an email to the announce mailing list, Subject: "Version X.Y.Z
   available for download". Be sure to include the download location, the
   release notes and the Changelog. Also, post an updated News item on the
   project page Sourceforge, and update the Home page and docs linked from
   the Home page (see below). Other news sites and release oriented sites,
   such as Freshmeat, should also be notified.

   --------------------------------------------------------------------------

7. Update the Webserver

   The webserver should be updated at least with each stable release. When
   updating, please follow these steps to make sure that no broken links,
   inconsistent contents or permission problems will occur (as it has many
   times in the past!):

   If you have changed anything in the stable-branch documentation source
   SGML files, do:

  make dok dok-pdf # (or 'make redhat-dok dok-pdf' if 'make dok' doesn't work for you)

   That will generate doc/webserver/user-manual,
   doc/webserver/developer-manual, doc/webserver/faq, doc/pdf/*.pdf and
   doc/webserver/index.html automatically.

   If you changed the manual page sources, generate
   doc/webserver/man-page/privoxy-man-page.html by running "make man". (This
   is a separate target due to dependencies on some obscure perl scripts [now
   in CVS, but not well tested]. See comments in GNUmakefile.)

   If you want to add new files to the webserver, create them locally in the
   doc/webserver/* directory (or create new directories under doc/webserver).

   Next, commit any changes from the above steps to CVS. All set? If these
   are docs in the stable branch, then do:

     make webserver

   This will do the upload to the webserver (www.privoxy.org) and ensure all
   files and directories there are group writable.

   Please do NOT use any other means of transferring files to the webserver
   to avoid permission problems. Also, please do not upload docs from
   development branches or versions. The publicly posted docs should be in
   sync with the last official release.

   --------------------------------------------------------------------------

8. Contacting the developers, Bug Reporting and Feature Requests

   We value your feedback. In fact, we rely on it to improve Privoxy and its
   configuration. However, please note the following hints, so we can provide
   you with the best support:

   --------------------------------------------------------------------------

  8.1. Get Support

   For casual users, our support forum at SourceForge is probably best
   suited: http://sourceforge.net/tracker/?group_id=11118&atid=211118

   All users are of course welcome to discuss their issues on the users
   mailing list, where the developers also hang around.

   Note that the Privoxy mailing lists are moderated. Posts from unsubscribed
   addresses have to be accepted manually by a moderator. This may cause a
   delay of several days and if you use a subject that doesn't clearly
   mention Privoxy or one of its features, your message may be accidentally
   discarded as spam.

   If you aren't subscribed, you should therefore spend a few seconds to come
   up with a proper subject. Additionally you should make it clear that you
   want to get CC'd. Otherwise some responses will be directed to the mailing
   list only, and you won't see them.

   --------------------------------------------------------------------------

  8.2. Reporting Problems

   "Problems" for our purposes, come in two forms:

     * Configuration issues, such as ads that slip through, or sites that
       don't function properly due to one Privoxy "action" or another being
       turned "on".

     * "Bugs" in the programming code that makes up Privoxy, such as that
       might cause a crash.

   --------------------------------------------------------------------------

    8.2.1. Reporting Ads or Other Configuration Problems

   Please send feedback on ads that slipped through, innocent images that
   were blocked, sites that don't work properly, and other configuration
   related problem of default.action file, to
   http://sourceforge.net/tracker/?group_id=11118&atid=460288, the Actions
   File Tracker.

   New, improved default.action files may occasionally be made available
   based on your feedback. These will be announced on the ijbswa-announce
   list and available from our the files section of our project page.

   --------------------------------------------------------------------------

    8.2.2. Reporting Bugs

   Please report all bugs through our bug tracker:
   http://sourceforge.net/tracker/?group_id=11118&atid=111118.

   Before doing so, please make sure that the bug has not already been
   submitted and observe the additional hints at the top of the submit form.
   If already submitted, please feel free to add any info to the original
   report that might help to solve the issue.

   Please try to verify that it is a Privoxy bug, and not a browser or site
   bug or documented behaviour that just happens to be different than what
   you expected. If unsure, try toggling off Privoxy, and see if the problem
   persists.

   If you are using your own custom configuration, please try the stock
   configs to see if the problem is configuration related. If you're having
   problems with a feature that is disabled by default, please ask around on
   the mailing list if others can reproduce the problem.

   If you aren't using the latest Privoxy version, the bug may have been
   found and fixed in the meantime. We would appreciate if you could take the
   time to upgrade to the latest version (or even the latest CVS snapshot)
   and verify that your bug still exists.

   Please be sure to provide the following information:

     * The exact Privoxy version you are using (if you got the source from
       CVS, please also provide the source code revisions as shown in
       http://config.privoxy.org/show-version).

     * The operating system and versions you run Privoxy on, (e.g. Windows XP
       SP2), if you are using a Unix flavor, sending the output of "uname -a"
       should do, in case of GNU/Linux, please also name the distribution.

     * The name, platform, and version of the browser you were using (e.g.
       Internet Explorer v5.5 for Mac).

     * The URL where the problem occurred, or some way for us to duplicate
       the problem (e.g. http://somesite.example.com/?somethingelse=123).

     * Whether your version of Privoxy is one supplied by the Privoxy
       developers via SourceForge, or if you got your copy somewhere else.

     * Whether you are using Privoxy in tandem with another proxy such as
       Tor. If so, please temporary disable the other proxy to see if the
       symptoms change.

     * Whether you are using a personal firewall product. If so, does Privoxy
       work without it?

     * Any other pertinent information to help identify the problem such as
       config or log file excerpts (yes, you should have log file entries for
       each action taken).

   You don't have to tell us your actual name when filing a problem report,
   but please use a nickname so we can differentiate between your messages
   and the ones entered by other "anonymous" users that may respond to your
   request if they have the same problem or already found a solution.

   Please also check the status of your request a few days after submitting
   it, as we may request additional information. If you use a SF id, you
   should automatically get a mail when someone responds to your request.

   The appendix of the Privoxy User Manual also has helpful information on
   understanding actions, and action debugging.

   --------------------------------------------------------------------------

  8.3. Request New Features

   You are welcome to submit ideas on new features or other proposals for
   improvement through our feature request tracker at
   http://sourceforge.net/tracker/?atid=361118&group_id=11118.

   --------------------------------------------------------------------------

  8.4. Other

   For any other issues, feel free to use the mailing lists. Technically
   interested users and people who wish to contribute to the project are also
   welcome on the developers list! You can find an overview of all
   Privoxy-related mailing lists, including list archives, at:
   http://sourceforge.net/mail/?group_id=11118.

   --------------------------------------------------------------------------

9. Privoxy Copyright, License and History

   Copyright © 2001-2008 by Privoxy Developers
   <ijbswa-developers@lists.sourceforge.net>

   Some source code is based on code Copyright © 1997 by Anonymous Coders
   and Junkbusters, Inc. and licensed under the GNU General Public License.

   --------------------------------------------------------------------------

  9.1. License

   Privoxy is free software; you can redistribute it and/or modify it under
   the terms of the GNU General Public License, version 2, as published by
   the Free Software Foundation.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
   for more details, which is available from the Free Software Foundation,
   Inc, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA

   You should have received a copy of the GNU General Public License along
   with this program; if not, write to the

    Free Software
    Foundation, Inc. 51 Franklin Street, Fifth Floor
    Boston, MA 02110-1301
    USA

   --------------------------------------------------------------------------

  9.2. History

   A long time ago, there was the Internet Junkbuster, by Anonymous Coders
   and Junkbusters Corporation. This saved many users a lot of pain in the
   early days of web advertising and user tracking.

   But the web, its protocols and standards, and with it, the techniques for
   forcing ads on users, give up autonomy over their browsing, and for
   tracking them, keeps evolving. Unfortunately, the Internet Junkbuster did
   not. Version 2.0.2, published in 1998, was (and is) the last official
   release available from Junkbusters Corporation. Fortunately, it had been
   released under the GNU GPL, which allowed further development by others.

   So Stefan Waldherr started maintaining an improved version of the
   software, to which eventually a number of people contributed patches. It
   could already replace banners with a transparent image, and had a first
   version of pop-up killing, but it was still very closely based on the
   original, with all its limitations, such as the lack of HTTP/1.1 support,
   flexible per-site configuration, or content modification. The last release
   from this effort was version 2.0.2-10, published in 2000.

   Then, some developers picked up the thread, and started turning the
   software inside out, upside down, and then reassembled it, adding many new
   features along the way.

   The result of this is Privoxy, whose first stable version, 3.0, was
   released August, 2002.

   --------------------------------------------------------------------------

10. See also

   Other references and sites of interest to Privoxy users:

   http://www.privoxy.org/, the Privoxy Home page.

   http://www.privoxy.org/faq/, the Privoxy FAQ.

   http://sourceforge.net/projects/ijbswa/, the Project Page for Privoxy on
   SourceForge.

   http://config.privoxy.org/, the web-based user interface. Privoxy must be
   running for this to work. Shortcut: http://p.p/

   http://sourceforge.net/tracker/?group_id=11118&atid=460288, to submit
   "misses" and other configuration related suggestions to the developers.

   http://www.junkbusters.com/ht/en/cookies.html, an explanation how cookies
   are used to track web users.

   http://www.junkbusters.com/ijb.html, the original Internet Junkbuster.

   http://privacy.net/, a useful site to check what information about you is
   leaked while you browse the web.

   http://www.squid-cache.org/, a popular caching proxy, which is often used
   together with Privoxy.

   http://www.pps.jussieu.fr/~jch/software/polipo/, Polipo is a caching proxy
   with advanced features like pipelining, multiplexing and caching of
   partial instances. In many setups it can be used as Squid replacement.

   http://tor.eff.org/, Tor can help anonymize web browsing, web publishing,
   instant messaging, IRC, SSH, and other applications.

   http://www.privoxy.org/developer-manual/, the Privoxy developer manual.