build: initial project release

src/process.dummy.app/_commands/EchoCommand.cs

@@ -0,0 +1,25 @@
+// Copyright (c) The Geekeey Authors
+// SPDX-License-Identifier: EUPL-1.2
+
+using Spectre.Console.Cli;
+
+internal sealed class EchoCommand : AsyncOutputCommand<EchoCommand.Settings>
+{
+	public sealed class Settings : OutputCommandSettings
+	{
+		[CommandOption("--separator <char>")] public string Separator { get; init; } = " ";
+		[CommandArgument(0, "[line]")] public string[] Items { get; init; } = [];
+	}
+
+	public override async Task<int> ExecuteAsync(CommandContext context, Settings settings, CancellationToken cancellationToken)
+	{
+		using var output = Output.Connect();
+
+		foreach (var writer in output.GetWriters(settings.Target))
+		{
+			await writer.WriteLineAsync(string.Join(settings.Separator, settings.Items));
+		}
+
+		return 0;
+	}
+}