skeeto

// Draw a triangle on Windows using OpenGL 1.1
// $ gcc -mwindows -o triangle triangle.c -lopengl32
// This is free and unencumbered software released into the public domain.
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <GL/gl.h>

#define countof(a) (int)(sizeof(a) / (sizeof(*(a))))

static LRESULT CALLBACK handler(HWND h, UINT msg, WPARAM wparam, LPARAM lparam)

skeeto

// 8-bit indexed PNG writer, no dependencies
// $ cc -o png png.c
// $ ./png >image.png
// This is free and unencumbered software released into the public domain.
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>

static uint32_t adler32(uint32_t sum, uint8_t *buf, ptrdiff_t len)
{

skeeto

// "Two Sum" benchmark
// $ cc -O1 -nostartfiles -o twoSum.exe twoSum.c
// $ cl /O1 twoSums.c /link /subsystem:console kernel32.lib libvcruntime.lib
// Ref: https://old.reddit.com/r/C_Programming/comments/1c36391
#include <stddef.h>
#include <stdint.h>
#include <string.h>

#define assert(c)     while (!(c)) *(volatile int *)0 = 0
#define new(a, t, n)  (t *)alloc(a, sizeof(t), _Alignof(t), n)

skeeto

// x86-64 Linux buffered "hello world"
// $ cc example.c && ./a.out
// Ref: https://old.reddit.com/r/C_Programming/comments/1bxvs3u
// Ref: https://thecoder08.github.io/hello-world.html
// Ref: https://nullprogram.com/blog/2023/02/13/
#include <stddef.h>
#include <string.h>

ptrdiff_t xwrite(int fd, void *buf, ptrdiff_t len)
{

skeeto

// $ cc -o persona persona.c
// $ ./persona <test.txt
// Ref: https://old.reddit.com/r/C_Programming/comments/1bmfb7p
#include <stddef.h>
#include <stdint.h>
#include <string.h>

#define assert(c)     while (!(c)) *(volatile int *)0 = 0
#define countof(a)    (ptrdiff_t)(sizeof(a) / sizeof(*(a)))
#define new(a, t, n)  (t *)alloc(a, sizeof(t), _Alignof(t), n)

skeeto

// Ref: https://old.reddit.com/r/golang/comments/1bcfe95/slice_as_map_key_in_go/
package main

import (
	"encoding/binary"
	"fmt"
	"math/rand"
	"slices"
	"strings"
	"testing"

skeeto

// $ cc -o graph graph.c
// $ ./a.out
// Ref: https://old.reddit.com/r/roguelikedev/comments/1b7pa9w/
#include <stdio.h>

static int rand31(unsigned long long *s)
{
    *s = *s*0x3243f6a8885a308dU + 1;
    return (int)(*s >> 33);
}

skeeto

// WriteProcessMemory demo
// $ cc -nostartfiles -o demo.exe demo.c
// $ cl demo.c /link /subsystem:console kernel32.lib
// This is free and unencumbered software released into the public domain.
#include <stddef.h>

#define countof(a) (ptrdiff_t)(sizeof(a) / sizeof(*(a)))

typedef unsigned char      u8;
typedef   signed int       b32;

skeeto

// Function hotpatch example
// $ gcc -nostartfiles -o hotpatch.exe hotpatch.c
// $ clang -nostdlib -Wl,/subsystem:console -o hotpatch.exe hotpatch.c -lkernel32
// This is free and unencumbered software released into the public domain.
#include <stddef.h>
#include <stdint.h>
#define W32 __attribute((dllimport, stdcall))
W32 void *CreateThread(void *, size_t, void *, void *, int, int *);
W32 int   FlushInstructionCache(void *, void *, size_t);
W32 void *GetStdHandle(int);

skeeto

#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define assert(c)     while (!(c)) *(volatile int *)0 = 0
#define countof(a)    (ptrdiff_t)(sizeof(a) / sizeof(*(a)))
#define new(a, t, n)  (t *)alloc(a, sizeof(t), n)
#define S(s)          (str){(char *)s, countof(s)-1}