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Before contributing to this project, please read the following suggestions.
They'll make life easier for everyone. This file is somewhat of a work in
progress. Don't hesitate to ask about a situation that's not covered here: it
may lead to a more thorough document.
# Commit Messages
* Must be wrapped to 72 characters or less
* First line should indicate *what* was changed, in the present tense, e.g.
"Fix off-by-one error in foobar.c"
# Acknowledgement
If you wish to be acknowledged for your contributions, add your name (if it
isn't already present) to the AUTHORS file before commiting your changes so pull
requests already include the relevant information. The format should be:
Firstname Lastname or Pseudonym <email-address>
Brief summary of contributions, indented by four spaces.
At least one of the four identifiers must be used, preferably whatever matches
your `.gitconfig` user information.
Keep in mind that this project is also licensed under the GPL version 3. The
terms of the license can be found in the LICENSE file. Please do not contribute
to this project if the GPL 3 is not a satisfactory license for you. While some
licenses may be compatible with the GPL, licensing individual files with
different licenses between authors very quickly becomes a mess and would
diminish the value of this project.
# Categories
There are [three categories][clc-cats] of solutions to K&R exercises. This
project aims for Category-0 (zero) compliance, which means that only concepts
that have been covered *up to* the current exercise can be used, and the code
must adhere to the ANSI/ISO C89 standard.
# Code Style
* `snake_case` preferred. Shortened names are acceptable, e.g. `vectsize` in lieu
of `get_vector_size`
* K&R (AKA 1TBS) indenting should be used. Opening braces are not permitted to
be on their own line.
* Tabs are four spaces wide and are exclusively used for indenting
* Spaces may be used to align on `:` or `=`; never indentation
* Names not meant to be used directly should be preceded by an underscore
* Constants should be in `ALL_CAPS`; shortened names still okay
* Operators must have exactly one (1) space on both sides, e.g. `1 + 1` instead
of `1+1`. One exception is pointers; the `*` symbol must be directly before
the beginning of the variable or function name, e.g. `char *buffer;`
* If `;` or `,` are used in a multi-statement line, they must be followed by one
space, e.g. `for (foo = 0; foo < bar; foo++) {`
* Empty lines are not allowed inside blocks (and thus functions, including
`main()`)
You can use the [astyle][astyle-home] package to run code through to ensure it
meets style guidelines. You'll need to run it like so:
astyle -A2TpHUjSxek3W3 [filename]
There is an `astylerc` file included in the repository for convenience.
## Variable Names
Try to use short, but descriptive variables for data that will be used
in a non-trivial way, i.e. not used as a one-off in a loop. In general,
shorthand variables `i`, `j`, and `k` are used for various loop levels, `c` for
characters, `s` for quick-and-dirty strings. Such shorthand names should only be
used when the name isn't very important. For example:
int strlen(char *s) {
int i;
for (i = 0; s[i] != '\0'; i++) {
/* do stuff */
}
return i;
}
In the above, it'd be pointless for `s` to be something like `input_string`
because we know based on the function name and the type of `s` that we're
dealing with a simple C string and we're just getting its length. `i` could be
renamed to `length` and be more semantic, but in this case it'd be expanding
for little gain. To sum up, use your best judgment. If there's any chance for
ambiguity, use a better name.
(Note: At the time of writing, the original author has some cleaning up to do,
too :P)
## Function Names
Much like variables, aim for something short, but descriptive. A lot of what's
in the K&R is given to you, so wherever possible, solutions should make use of
functions already made available in the text, or minor alterations thereof.
## Comments
C has two commenting syntaxes. Most projects prefer one or the other. Both
syntaxes are generally okay; however, since Category-0 solutions adhere to the
C89/C90 standard, only multi-line comments (`/* like this */`) should be used.
At the time of writing, this is in need of correction and is already planned to
be retroactively fixed.
Comment use in code should be minimal; if a comment is reiterating what's
already there, it's a bad comment. Comments should discuss *what* is going on if
it's not obvious, and/or *why* you're doing it. The following is pretty useless:
int i; /* Array index */
But this can be useful for someone trying to follow along and learn:
/* Subtract one from the string's length to account for the NUL terminator.
* This ensures that the correct length for actual string content is
* reported.
*/
return (len - 1);
[clc-cats]: http://clc-wiki.net/wiki/K%26R2_solutions:Ancillary:Category_numbers
[astyle-home]: http://astyle.sourceforge.net
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