Hello, world!

This is the first tutorial in the series. It will show you how to create a simple "Hello, world!" program in C++ for skiftOS.

First, create a new directory for your project and navigate to it:

# You need to be in the root of the skiftOS repository

$ mkdir -p src/tutorial/hello-world

$ cd src/tutorial/hello-world

# Open the project directory in your favorite text editor, for example VSCode
$ code .

Write the manifest

Create a manifest.json file in the project directory:

{
    "$schema": "https://schemas.cute.engineering/stable/cutekit.manifest.component.v1",
    "id": "hello-world",
    "type": "exe",
    "description": "Greets the world",
    "requires": [
        "karm-sys"
    ]
}

Here is a brief explanation of the fields in the manifest:

$schema: The schema of the manifest file. It should always be https://schemas.cute.engineering/stable/cutekit.manifest.component.v1.
id: The unique identifier of the component. It should be unique across all components.
type: The type of the component. It should be exe for an executable.
description: A brief description of the component.
requires: A list of components that this component depends on.

Write the source code

Create a main.cpp file in the project directory:

#include <karm-sys/entry.h>

// The entry point of the program, skiftOS doesn't use `main` function
Async::Res<> entryPointAsync(Sys::Context &) {
    // Print "Hello, world!" to the console
    Sys::println("Hello, world!");

    // Return success
    co_return Ok();
}