alepez

// You have an API which requires functions to be called in a defined order
// This may be a C API
mod no_order_constraint {
    pub fn one() {
        println!("one");
    }

    pub fn two() {
        println!("two");
    }

alepez

wget https://github.com/llvm/llvm-project/archive/refs/tags/llvmorg-14.0.6.tar.gz
tar zxf llvmorg-14.0.6.tar.gz

cd llvm-project-llvmorg-14.0.6
rm -rf build
mkdir -p build
cd build

cmake \
  -G Ninja \

alepez

/// Simple DirectMedia Layer Example
/// If everything is correctly installed, you should see a black window
/// which is gradually filled with white, starting from the top.
#include <SDL2/SDL.h>

int main() {
  auto sdl_init_result = SDL_Init(SDL_INIT_VIDEO);

  if (sdl_init_result != 0) {
    return 1;

alepez

Say that you have compiled an executable for a Linux ARM system and you want to test it inside a Linux x86 system. Docker is able to use qemu to enable execution of different multi-architecture containers.

Execute the register script that registers binfmt_misc handlers for all supported processors except the current one in it when running the container.

docker run --rm --privileged multiarch/qemu-user-static --reset -p yes

alepez

#include <stdio.h>

// a is an input parameter
// b is an input parameter
// return the result
int divide_1(int a, int b) {
  return a / b;
}

// But what if we need to return an error code?

alepez

NixOs neon

Partitions

DISK=/dev/disk/by-id/ata-VBOX_HARDDISK_VBf3bca3fc-20a6ea2d
parted -s ${DISK} -- mklabel gpt
parted -s ${DISK} -- mkpart primary 512MiB -8GiB
parted -s ${DISK} -- mkpart primary linux-swap -8GiB 100%
parted -s ${DISK} -- mkpart ESP fat32 1MiB 512MiB

alepez

#!/bin/bash

init() {
  ip link set can0 type can bitrate 250000
  ip link set can0 up
}

rawdump() {
  candump can0
}

alepez

Unmanaged C code:

typedef void(read_fun_t)(void* user_data, const char* data, int data_len);

int native_consume_all(native_handler handler, void* user_data, read_fun_t* read_fun);

Managed C++ code:

alepez

VirtualBox gust screen resolution doesn't work well under i3wm, sometime it get stuck at some strange resolution.

This script can fix the window size.

From the guest side, we use VBoxManage to tell the guest that a new resolution is available.

Window is made floating, then the border is removed (it count as width/height), then the window is resized.

alepez

#!/bin/bash

init() {
  ip link set can0 type can bitrate 250000
  ip link set can0 up
}

rawdump() {
  candump can0
}