dotnet-installer/build_projects/dotnet-cli-build/GetCurrentRuntimeInformation.cs

using Microsoft.Build.Framework;
using Microsoft.Build.Utilities;
using Microsoft.DotNet.InternalAbstractions;

namespace Microsoft.DotNet.Cli.Build
{
    public class GetCurrentRuntimeInformation : Task
    {
        [Output]
        public string Rid { get; set; }

        [Output]
        public string Architecture { get; set; }

        [Output]
        public string OSName { get; set; }

        public override bool Execute()
        {
            Rid = RuntimeEnvironment.GetRuntimeIdentifier();
            Architecture = RuntimeEnvironment.RuntimeArchitecture;
            OSName = Monikers.GetOSShortName();

            return true;
        }
    }
}