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><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="CODING"
></A
>4. Coding Guidelines</H1
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="S1"
></A
>4.1. Introduction</H2
><P
>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
<SPAN
CLASS="APPLICATION"
>Privoxy</SPAN
>" consistent and reliable. Thus making
maintenance easier and increasing chances of success of the
project.</P
><P
>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. ;-></P
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="S2"
></A
>4.2. Using Comments</H2
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S3"
></A
>4.2.1. Comment, Comment, Comment</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>Comment as much as possible without commenting the obvious.
For example do not comment "aVariable is equal to bVariable".
Instead explain why aVariable should be equal to the bVariable.
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!</P
><P
>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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>/* if page size greater than 1k ... */
if ( PageLength() > 1024 )
{
... "block" the page up ...
}
/* if page size is small, send it in blocks */
if ( PageLength() > 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.</PRE
></TD
></TR
></TABLE
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S4"
></A
>4.2.2. Use blocks for comments</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>/*********************************************************************
* This will stand out clearly in your code!
*********************************************************************/
if ( thisVariable == thatVariable )
{
DoSomethingVeryImportant();
}
/* unfortunately, this may not */
if ( thisVariable == thatVariable )
{
DoSomethingVeryImportant();
}
if ( thisVariable == thatVariable ) /* this may not either */
{
DoSomethingVeryImportant();
}</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Exception:</I
></SPAN
></P
><P
>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.</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S5"
></A
>4.2.3. Keep Comments on their own line</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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.</P
><P
>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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>/*********************************************************************
* This will stand out clearly in your code,
* But the second example won't.
*********************************************************************/
if ( thisVariable == thatVariable )
{
DoSomethingVeryImportant();
}
if ( thisVariable == thatVariable ) /*can you see me?*/
{
DoSomethingVeryImportant(); /*not easily*/
}
/*********************************************************************
* But, the encouraged exceptions:
*********************************************************************/
int urls_read = 0; /* # of urls read + rejected */
int urls_rejected = 0; /* # of urls rejected */
if ( 1 == X )
{
DoSomethingVeryImportant();
}
short DoSomethingVeryImportant(
short firstparam, /* represents something */
short nextparam /* represents something else */ )
{
...code here...
} /* -END- DoSomethingVeryImportant */</PRE
></TD
></TR
></TABLE
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S6"
></A
>4.2.4. Comment each logical step</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>Logical steps should be commented to help others follow the
intent of the written code and comments will make the code more
readable.</P
><P
>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.</P
><P
>Most "for", "while", "do", etc... loops _probably_ need a
comment. After all, these are usually major logic
containers.</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S7"
></A
>4.2.5. Comment All Functions Thoroughly</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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.</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S8"
></A
>4.2.6. Comment at the end of braces if the
content is more than one screen length</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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.</P
><P
>As a suggestion , use the following flags to make the
comment and its brace more readable:</P
><P
>use following a closing brace: } /* -END- if() or while ()
or etc... */</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>if ( 1 == X )
{
DoSomethingVeryImportant();
...some long list of commands...
} /* -END- if x is 1 */
or:
if ( 1 == X )
{
DoSomethingVeryImportant();
...some long list of commands...
} /* -END- if ( 1 == X ) */</PRE
></TD
></TR
></TABLE
></DIV
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="S9"
></A
>4.3. Naming Conventions</H2
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S10"
></A
>4.3.1. Variable Names</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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++.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>int ms_iis5_hack = 0;</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Instead of:</I
></SPAN
></P
><P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>int msiis5hack = 0; int msIis5Hack = 0;</PRE
></TD
></TR
></TABLE
></P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S11"
></A
>4.3.2. Function Names</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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++.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>int load_some_file( struct client_state *csp )</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Instead of:</I
></SPAN
></P
><P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>int loadsomefile( struct client_state *csp )
int loadSomeFile( struct client_state *csp )</PRE
></TD
></TR
></TABLE
></P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S12"
></A
>4.3.3. Header file prototypes</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>(.h) extern int load_aclfile( struct client_state *csp );
(.c) int load_aclfile( struct client_state *csp )</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Instead of:</I
></SPAN
>
<TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>(.h) extern int load_aclfile( struct client_state * ); or
(.h) extern int load_aclfile();
(.c) int load_aclfile( struct client_state *csp )</PRE
></TD
></TR
></TABLE
></P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S13"
></A
>4.3.4. Enumerations, and #defines</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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.)</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>(enumeration) : enum Boolean { FALSE, TRUE };
(#define) : #define DEFAULT_SIZE 100;</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Note:</I
></SPAN
> 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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>#define FEATURE_FORCE 1
#ifdef FEATURE_FORCE
#define FORCE_PREFIX blah
#endif /* def FEATURE_FORCE */</PRE
></TD
></TR
></TABLE
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S14"
></A
>4.3.5. Constants</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>Spell common words out entirely (do not remove vowels).</P
><P
>Use only widely-known domain acronyms and abbreviations.
Capitalize all letters of an acronym.</P
><P
>Use underscore (_) to separate adjacent acronyms and
abbreviations. Never terminate a name with an underscore.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>#define USE_IMAGE_LIST 1</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Instead of:</I
></SPAN
></P
><P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>#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</PRE
></TD
></TR
></TABLE
></P
></DIV
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="S15"
></A
>4.4. Using Space</H2
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S16"
></A
>4.4.1. Put braces on a line by themselves.</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>if ( this == that )
{
...
}</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Instead of:</I
></SPAN
></P
><P
>if ( this == that ) { ... }</P
><P
>or</P
><P
>if ( this == that ) { ... }</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Note:</I
></SPAN
> 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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Status:</I
></SPAN
> developer-discretion.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example exception:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>while ( more lines are read )
{
/* Please document what is/is not a comment line here */
if ( it's a comment ) continue;
do_something( line );
}</PRE
></TD
></TR
></TABLE
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S17"
></A
>4.4.2. ALL control statements should have a
block</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>if ( this == that )
{
DoSomething();
DoSomethingElse();
}</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Instead of:</I
></SPAN
></P
><P
>if ( this == that ) DoSomething(); DoSomethingElse();</P
><P
>or</P
><P
>if ( this == that ) DoSomething();</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Note:</I
></SPAN
> 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.</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S18"
></A
>4.4.3. Do not belabor/blow-up boolean
expressions</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>structure->flag = ( condition );</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Instead of:</I
></SPAN
></P
><P
>if ( condition ) { structure->flag = 1; } else {
structure->flag = 0; }</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Note:</I
></SPAN
> 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-)</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S19"
></A
>4.4.4. Use white space freely because it is
free</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>Make it readable. The notable exception to using white space
freely is listed in the next guideline.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>int firstValue = 0;
int someValue = 0;
int anotherValue = 0;
int thisVariable = 0;
if ( thisVariable == thatVariable )
firstValue = oldValue + ( ( someValue - anotherValue ) - whatever )</PRE
></TD
></TR
></TABLE
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S20"
></A
>4.4.5. Don't use white space around structure
operators</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>- structure pointer operator ( "->" ) - member operator (
"." ) - functions and parentheses</P
><P
>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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>aStruct->aMember;
aStruct.aMember;
FunctionName();</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Instead of:</I
></SPAN
> aStruct -> aMember; aStruct . aMember;
FunctionName ();</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S21"
></A
>4.4.6. Make the last brace of a function stand
out</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>int function1( ... )
{
...code...
return( retCode );
} /* -END- function1 */
int function2( ... )
{
} /* -END- function2 */</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Instead of:</I
></SPAN
></P
><P
>int function1( ... ) { ...code... return( retCode ); } int
function2( ... ) { }</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Note:</I
></SPAN
> 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!</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Status:</I
></SPAN
> developer-discretion on the number of blank
lines. Enforced is the end of function comments.</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S22"
></A
>4.4.7. Use 3 character indentions</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>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 );
}</PRE
></TD
></TR
></TABLE
></DIV
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="S23"
></A
>4.5. Initializing</H2
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S24"
></A
>4.5.1. Initialize all variables</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>short anShort = 0;
float aFloat = 0;
struct *ptr = NULL;</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Note:</I
></SPAN
> It is much easier to debug a SIGSEGV if the
message says you are trying to access memory address 00000000
and not 129FA012; or arrayPtr[20] causes a SIGSEV vs.
arrayPtr[0].</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Status:</I
></SPAN
> developer-discretion if and only if the
variable is assigned a value "shortly after" declaration.</P
></DIV
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="S25"
></A
>4.6. Functions</H2
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S26"
></A
>4.6.1. Name functions that return a boolean as a
question.</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>Value should be phrased as a question that would logically
be answered as a true or false statement</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>ShouldWeBlockThis();
ContainsAnImage();
IsWebPageBlank();</PRE
></TD
></TR
></TABLE
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S27"
></A
>4.6.2. Always specify a return type for a
function.</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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.</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S28"
></A
>4.6.3. Minimize function calls when iterating by
using variables</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>It is easy to write the following code, and a clear argument
can be made that the code is easy to understand:</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>for ( size_t cnt = 0; cnt < blockListLength(); cnt ++ )
{
....
}</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Note:</I
></SPAN
> 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 blockListLength() 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 blockListLength() is a function
call, with the same overhead.</P
><P
>Instead of using a function call during the iterations,
assign the value to a variable, and evaluate using the
variable.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>size_t len = blockListLength();
for ( size_t cnt = 0; cnt < len; cnt ++ )
{
....
}</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Exceptions:</I
></SPAN
> if the value of blockListLength() *may*
change or could *potentially* change, then you must code the
function call in the for/while loop.</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S29"
></A
>4.6.4. Pass and Return by Const Reference</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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 );</P
><P
>I could then not use it to compare argv's in main: int main(
int argc, const char *argv[] ) { strcmp( argv[0], "privoxy"
); }</P
><P
>Both these pointers are *const*! If the c runtime library
maintainers do it, we should too.</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S30"
></A
>4.6.5. Pass and Return by Value</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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 )</P
><P
>would not work. So, to be consistent, we should declare all
prototypes with "pass by value": int load_aclfile( struct
client_state *csp )</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S31"
></A
>4.6.6. Names of include files</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>#include <iostream.h> /* This is not a local include */
#include "config.h" /* This IS a local include */</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Exception:</I
></SPAN
></P
><P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>/* This is not a local include, but requires a path element. */
#include <sys/fileName.h></PRE
></TD
></TR
></TABLE
></P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Note:</I
></SPAN
> Please! do not add "-I." to the Makefile
without a _very_ good reason. This duplicates the #include
"file.h" behavior.</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S32"
></A
>4.6.7. Provide multiple inclusion
protection</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>Prevents compiler and linker errors resulting from
redefinition of items.</P
><P
>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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>#ifndef PROJECT_H_INCLUDED
#define PROJECT_H_INCLUDED
...
#endif /* ndef PROJECT_H_INCLUDED */</PRE
></TD
></TR
></TABLE
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S33"
></A
>4.6.8. Use `extern "C"` when appropriate</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>#ifdef __cplusplus
extern "C"
{
#endif /* def __cplusplus */
... function definitions here ...
#ifdef __cplusplus
}
#endif /* def __cplusplus */</PRE
></TD
></TR
></TABLE
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S34"
></A
>4.6.9. Where Possible, Use Forward Struct
Declaration Instead of Includes</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>Useful in headers that include pointers to other struct's.
Modifications to excess header files may cause needless
compiles.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>/*********************************************************************
* We're avoiding an include statement here!
*********************************************************************/
struct file_list;
extern file_list *xyz;</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Note:</I
></SPAN
> 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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Status:</I
></SPAN
> Use with discretion.</P
></DIV
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="S35"
></A
>4.7. General Coding Practices</H2
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S36"
></A
>4.7.1. Turn on warnings</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation</I
></SPAN
></P
><P
>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.</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S37"
></A
>4.7.2. Provide a default case for all switch
statements</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>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 ) ) */</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Note:</I
></SPAN
> 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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Another Note:</I
></SPAN
> 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 ABEND condition.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Status:</I
></SPAN
> Programmer discretion is advised.</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S38"
></A
>4.7.3. Try to avoid falling through cases in a
switch statement.</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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.</P
><P
>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.</P
><P
>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.</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S39"
></A
>4.7.4. Use 'long' or 'short' Instead of
'int'</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>On 32-bit platforms, int usually has the range of long. On
16-bit platforms, int has the range of short.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Status:</I
></SPAN
> 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?</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S40"
></A
>4.7.5. Don't mix size_t and other types</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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. Try to avoid using size_t if
you can.</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S41"
></A
>4.7.6. Declare each variable and struct on its
own line.</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>It can be tempting to declare a series of variables all on
one line. Don't.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>long a = 0;
long b = 0;
long c = 0;</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Instead of:</I
></SPAN
></P
><P
>long a, b, c;</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
> - 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</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Exceptions:</I
></SPAN
> when you want to declare a bunch of loop
variables or other trivial variables; feel free to declare them
on 1 line. You should, although, provide a good comment on
their functions.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Status:</I
></SPAN
> developer-discretion.</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S42"
></A
>4.7.7. Use malloc/zalloc sparingly</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>Create a local struct (on the stack) if the variable will
live and die within the context of one function call.</P
><P
>Only "malloc" a struct (on the heap) if the variable's life
will extend beyond the context of one function call.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>If a function creates a struct and stores a pointer to it in a
list, then it should definitely be allocated via `malloc'.</PRE
></TD
></TR
></TABLE
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S43"
></A
>4.7.8. The Programmer Who Uses 'malloc' is
Responsible for Ensuring 'free'</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>int load_re_filterfile( struct client_state *csp ) { ... }
static void unload_re_filterfile( void *f ) { ... }</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Exceptions:</I
></SPAN
></P
><P
>The developer cannot be expected to provide `free'ing
functions for C run-time library functions ... such as
`strdup'.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Status:</I
></SPAN
> developer-discretion. The "main" use of this
standard is for allocating and freeing data structures (complex
or nested).</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S44"
></A
>4.7.9. Add loaders to the `file_list' structure
and in order</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Note:</I
></SPAN
> 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.</P
></DIV
><DIV
CLASS="SECT3"
><H3
CLASS="SECT3"
><A
NAME="S45"
></A
>4.7.10. "Uncertain" new code and/or changes to
existing code, use FIXME</H3
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Explanation:</I
></SPAN
></P
><P
>If you have enough confidence in new code or confidence in
your changes, but are not *quite* sure of the repercussions,
add this:</P
><P
>/* FIXME: this code has a logic error on platform XYZ, *
attempting to fix */ #ifdef PLATFORM ...changed code here...
#endif</P
><P
>or:</P
><P
>/* FIXME: I think the original author really meant this...
*/ ...changed code here...</P
><P
>or:</P
><P
>/* FIXME: new code that *may* break something else... */
...new code here...</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Note:</I
></SPAN
> 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).</P
></DIV
></DIV
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="S46"
></A
>4.8. Addendum: Template for files and function
comment blocks:</H2
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example for file comments:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>const char FILENAME_rcs[] = "$Id: developer-manual.sgml,v 1.46.2.8 2002/08/17 00:16:10 hal9 Exp $";
/*********************************************************************
*
* File : $Source$
*
* Purpose : (Fill me in with a good description!)
*
* Copyright : Written by and Copyright (C) 2001 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., 59
* Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Revisions :
* $Log$
*
*********************************************************************/
#include "config.h"
...necessary include files for us to do our work...
const char FILENAME_h_rcs[] = FILENAME_H_VERSION;</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Note:</I
></SPAN
> 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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Note:</I
></SPAN
> 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.</P
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example for file header comments:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>#ifndef _FILENAME_H
#define _FILENAME_H
#define FILENAME_H_VERSION "$Id: developer-manual.sgml,v 1.46.2.8 2002/08/17 00:16:10 hal9 Exp $"
/*********************************************************************
*
* File : $Source$
*
* Purpose : (Fill me in with a good description!)
*
* Copyright : Written by and Copyright (C) 2001 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., 59
* Temple Place - Suite 330, Boston, MA 02111-1307, 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:
*/</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Example for function comments:</I
></SPAN
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>/*********************************************************************
*
* 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 );
}</PRE
></TD
></TR
></TABLE
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>Note:</I
></SPAN
> If we all follow this practice, we should be
able to parse our code to create a "self-documenting" web
page.</P
></DIV
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