My C code style

c.md

my opinionated C coding style

derived from suckless coding style

standard

• always use -std=c99 -pedantic

comments

• prefer // ... style comments
• for multiline comments, keep initial * and last * on their own lines.

/*
 * hello!
 */

if

• do not explicitly test against NULL or 0

keywords

• space after if, while, for, switch
• make use of for initializer (c99)
• use () with sizeof
• do not use space(s) after the opening ( and closing )
• do not use space with sizeof()

switch

• do not indent cases

switch (a) {
case 50:
	break;
case 20:
	break;
default:
	break;

casing

• type names: HelloThereHowAreYouDoing
• everything else: hello_how_are_you_doing

types

• always typedef structs/unions
• capitalize type name, see casing
• feel free to typedef types using builtin types if you feel that they should be abstracted away
  • don't use this too much

lines

• max line length: 80 columns
• if if is too complex, wrap the entire statement like this:

if (
	something == 3 &&
	something_else == 40 ||
	i_dont_know == 130) {
	// hello
}

file structure

each of these sections must be separated by 2 newlines.

section 1 ends (newline)
(newline)
section 2 begins

1. comment describing file/license (optional)
2. any guards, if any
   • e.g. #pragma once or #ifndef guards
3. system/std headers
   • #include <s.h>
   • doesn't have to be in alphabetical order
4. local headers
   • #include "s.h"
   • doesn't have to be in alphabetical order
5. macros/typedefs
   • if any macros/typedefs have to be defined before includes, do so but add a comment describing why
6. type declarations (if any)
7. function declarations (if any)
8. function definition (code) + main

goto

• only use goto in order to clean up/defer actions upon error

void block() {
	if (action() == 1) {
		goto fail;
	}

	return;

fail:
	cleanup();
}

• do not indent labels

braces

• opening braces are always on the same line
  • except when ending block and continuing (else, else if)

void init_engine(int a, int b) {
	// ...
	if (a == 20) {
	} else if (b == 50) {
	} else {
		// ...
	}
}

functions

• keep variable declarations at the top of block
  • if needed, initialize them

void block() {
	int a = 20;
	bool something = false;
	// ...
}

• keep return type and name on the same line

void init_engine(int* a, const char* b) {
	// ...
}

• if there are too many arguments, wrap like this:

void init_engine(
	int* a,
	const char* b
) {
	// ...
}

variables

• * is next to type name, not variable name

int* int_ptr;

static

• things not used outside of the translation unit should be static
  • applies to functions and global variables

indentation

• always use tabs
  • set width to your liking in your editor
• use spaces for alignment
• things should line up regardless of tab width