Sandman - simple program to immediately put my monitors to sleep when I'm going to bed, and keep them off for a certain amount of time. Got tired of simply waiting for my screens to turn off by themselves (since I never actually put my desktop to sleep), only to be randomly woken up by my mouse shifting a pixel due to some sensor noise or someth…

Sandman.cs

/*
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

using System;
using System.Runtime.InteropServices;
using System.Threading;

namespace Sandman
{
    class Program
    {
        [DllImport("user32.dll")]
        static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, UInt32 wParam, UInt32 lParam);

        [DllImport("kernel32.dll")]
        static extern IntPtr GetConsoleWindow();

        //Values from http://msdn.microsoft.com/en-us/library/windows/desktop/ms646360.aspx
        const UInt32 WM_SYSCOMMAND = 0x0112;
        const UInt32 SC_MONITORPOWER = 0xF170;
        enum SC_MONITORPOWER_LPARAM : uint
        {
            PoweringOn = unchecked((uint)-1),
            LowPower = 1,
            PoweringOff = 2
        }

        static void Main(string[] args)
        {
            int sleepTime = 3 * 60; //default 3 hours
            if( args.Length > 0 )
                Int32.TryParse(args[0], out sleepTime);
            
            Console.WriteLine("Hit Ctrl+C to cancel...");
            Console.ReadKey(true);

            Console.WriteLine( String.Format("Sleeping display(s) for {0} minutes...", sleepTime) );
            Thread.Sleep(1500);

            //repeatedly send the message, just to make sure no lingering Key Up or accidental/sensor noise mouse movement events accidentally wake the screens
            DateTime start = DateTime.UtcNow;
            do
            {
                SendMessage(GetConsoleWindow(), WM_SYSCOMMAND, SC_MONITORPOWER, (uint)SC_MONITORPOWER_LPARAM.PoweringOff);
                Thread.Sleep(5000);
            }
            while( DateTime.UtcNow < start.AddMinutes(sleepTime) );
        }
    }
}