Imported Upstream version 5.2.0.175

Former-commit-id: bb0468d0f257ff100aa895eb5fe583fb5dfbf900

mcs/class/Mono.Options/Documentation/en/examples/commands.cs

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+// Sub-commands with Mono.Options.CommandSet
+//
+// Compile as:
+//   mcs -r:Mono.Options.dll commands.cs
+
+using System;
+using System.Collections.Generic;
+
+using Mono.Options;
+
+class CommandDemo {
+	public static int Main (string[] args)
+	{
+		var commands = new CommandSet ("commands") {
+			"usage: commands COMMAND [OPTIONS]",
+			"",
+			"Mono.Options.CommandSet sample app.",
+			"",
+			"Global options:",
+			{ "v:",
+			  "Output verbosity.",
+			  (int? n) => Verbosity = n.HasValue ? n.Value : Verbosity + 1 },
+			"",
+			"Available commands:",
+			new Command ("echo", "Echo arguments to the screen") {
+				Run = ca => Console.WriteLine ("{0}", string.Join (" ", ca)),
+			},
+			new RequiresArgs (),
+		};
+		return commands.Run (args);
+	}
+
+	public static int Verbosity;
+}
+
+class RequiresArgs : Command {
+
+	public RequiresArgs ()
+		: base ("requires-args", "Class-based Command subclass")
+	{
+		Options = new OptionSet () {
+			"usage: commands requires-args [OPTIONS]",
+			"",
+			"Class-based Command subclass example.",
+			{ "name|n=",
+			  "{name} of person to greet.",
+			  v => Name = v },
+			{ "help|h|?",
+			  "Show this message and exit.",
+			  v => ShowHelp = v != null },
+		};
+	}
+
+	public        bool    ShowHelp    {get; private set;}
+	public  new   string  Name        {get; private set;}
+
+	public override int Invoke (IEnumerable<string> args)
+	{
+		try {
+			var extra = Options.Parse (args);
+			if (ShowHelp) {
+				Options.WriteOptionDescriptions (CommandSet.Out);
+				return 0;
+			}
+			if (string.IsNullOrEmpty (Name)) {
+				Console.Error.WriteLine ("commands: Missing required argument `--name=NAME`.");
+				Console.Error.WriteLine ("commands: Use `commands help requires-args` for details.");
+				return 1;
+			}
+			Console.WriteLine ($"Hello, {Name}!");
+			return 0;
+		}
+		catch (Exception e) {
+			Console.Error.WriteLine ("commands: {0}", CommandDemo.Verbosity >= 1 ? e.ToString () : e.Message);
+			return 1;
+		}
+	}
+}