SHUTDOWNEVERYTHING.cs

using System;
using System.Collections.Generic;
using System.IO.Pipes;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SHUTDOWNEVERYTHING
{
    class Program
    {
        private static readonly byte[] validateBytes = new[] { 'S', 'Q', 'U', 'I', 'R', 'R', 'E', 'L' }.Select(x => (byte)x).ToArray();
        private static readonly byte[] exitMessage = new[] { 'E', 'X', 'I', 'T' }.Select(x => (byte)x).ToArray();
        static void Main(string[] args)
        {
            // note I did a s/Shimmer/Squirrel on the sample
            // if you kept the package name as ShimmerDesktopDemo change it here
            var pipeClient = new NamedPipeClientStream(".", "SquirrelPipe SquirrelDesktopDemo", PipeDirection.InOut, PipeOptions.None);
            bool connected = false;
            try
            {
                pipeClient.Connect(1000);
                connected = true;
            }
            catch (TimeoutException) { }

            if (connected)
            {
                var buffer = new byte[validateBytes.Length];
                pipeClient.Read(buffer, 0, validateBytes.Length);

                if (buffer.SequenceEqual(validateBytes))
                {
                    pipeClient.Write(exitMessage, 0, exitMessage.Length);
                    Console.WriteLine("Attempted to request running instance to exit");
                }
                else
                {
                    Console.WriteLine("Connected to a named pipe but didn't respond or wasn't Squirrel");
                }
            }
            else
            {
                Console.WriteLine("No running instances found to request exit");
            }
        }
    }
}