Intrinsic commands and log suppression

When the host starts up, configuration providers, logging infrastructure, and other services initialize before the CLI runs. This means commands like --help or --version can be preceded by startup noise in the output.

AddArgh addresses this automatically. If the invocation is an intrinsic command - a built-in (--help, -h, --version, __schema, __completion, __complete) or a user-defined method marked [CommandIntrinsic] - it configures logging to suppress entries below Warning before the host builds.

Mark any handler method [CommandIntrinsic] to opt it into the same log suppression. These commands still run through the full host and DI because they may need services:

public class InfoCommands
{
    private readonly IVersionService _version;
    public InfoCommands(IVersionService version) => _version = version;

    /// <summary>Print runtime version and environment info.</summary>
    [CommandIntrinsic]
    [CommandName("info")]
    public void Info() => Console.WriteLine(_version.Current);
}

builder.Services.AddArgh(args, b => b.Map<InfoCommands>());
		

Running dotnet run -- info produces output with no startup log noise.

The default minimum level is Warning (suppresses Information and below). Override it on the hosting builder:

builder.Services.AddArgh(args, b =>
{
    b.IntrinsicLogLevelMinimum(LogLevel.Trace);
    b.Map<InfoCommands>();
});
		

1. Re-enables all log levels for intrinsic commands

If host startup is expensive and you want zero overhead for the built-in intrinsic commands, call ArghApp.TryArghIntrinsicCommand(args) before Host.CreateApplicationBuilder. If the invocation is a built-in, the command runs and the process exits immediately. The host is never constructed.

await ArghApp.TryArghIntrinsicCommand(args);

var builder = Host.CreateApplicationBuilder(args);
builder.Services.AddArgh(args, b => { b.Map<InfoCommands>(); });
await builder.Build().RunAsync();
		

1. Built-ins exit here with no host overhead: --help, --version, __schema, etc.