C# | System.CommandLine ライブラリを使用したコマンドライン (CLI) アプリの構築

dotnet new console -n MyCommandLineApp
cd MyCommandLineApp

dotnet add package System.CommandLine --version 2.0.0-beta1.21308.1

using System.CommandLine;
using System.CommandLine.Invocation;

class Program
{
    static int Main(string[] args)
    {
        var rootCommand = new RootCommand
        {
            new Option<int>("--number", "An integer option"),
            new Option<bool>("--flag", "A boolean option"),
            new Argument<string>("input", "A required input argument")
        };

        rootCommand.Handler = CommandHandler.Create<int, bool, string>((number, flag, input) =>
        {
            // Your application logic goes here
            Console.WriteLine($"Number: {number}");
            Console.WriteLine($"Flag: {flag}");
            Console.WriteLine($"Input: {input}");
        });

        return rootCommand.Invoke(args);
    }
}

dotnet run -- --number 42 --flag true "Hello, CLI!"

var rootCommand = new RootCommand
{
    new Option<int>("--number", "An integer option"),
    new Option<bool>("--flag", "A boolean option"),
    new Argument<string>("input", "A required input argument")
};

rootCommand.Description = "A simple CLI app";
rootCommand.Handler = CommandHandler.Create<int, bool, string>((number, flag, input) =>
{
    Console.WriteLine($"Number: {number}");
    Console.WriteLine($"Flag: {flag}");
    Console.WriteLine($"Input: {input}");
});