//-----------------------------------------------------------------------
//  This file is part of the Microsoft .NET Framework SDK Code Samples.
// 
//  Copyright (C) Microsoft Corporation.  All rights reserved.
// 
//This source code is intended only as a supplement to Microsoft
//Development Tools and/or on-line documentation.  See these other
//materials for detailed information regarding Microsoft code samples.
// 
//THIS CODE AND INFORMATION ARE PROVIDED AS IS WITHOUT WARRANTY OF ANY
//KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
//IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
//PARTICULAR PURPOSE.
//-----------------------------------------------------------------------
using System;
using System.Collections;
using System.Security;
using System.Security.Permissions;

[assembly:EnvironmentPermission(SecurityAction.RequestMinimum,
Read="PROCESSOR_IDENTIFIER;PROCESSOR_REVISION;NUMBER_OF_PROCESSORS;OS")]
[assembly:EnvironmentPermission(SecurityAction.RequestOptional, Unrestricted=true)]
[assembly:EnvironmentPermission(SecurityAction.RequestRefuse,
Read="USERNAME;USERDOMAIN;USERDNSDOMAIN;COMPUTERNAME;LOGONSERVER",
Write="USERNAME;USERDOMAIN;USERDNSDOMAIN;COMPUTERNAME;LOGONSERVER")]

namespace Microsoft.Samples
{
	public sealed class PermRequest 
	{
		private PermRequest()
		{
		}

		public static void Main() 
		{
			//We are guaranteed to get these (providing they are set, of course)
			Console.WriteLine("Processor: {0}", GetEnvironmentValue("PROCESSOR_IDENTIFIER"));
			Console.WriteLine("Revision: {0}", GetEnvironmentValue("PROCESSOR_REVISION"));
			Console.WriteLine("Count: {0}", Environment.GetEnvironmentVariable("NUMBER_OF_PROCESSORs"));
			Console.WriteLine("Operating System: {0}", GetEnvironmentValue("OS"));

			//We may or may not get these depending upon security policy
			Console.WriteLine("System Drive: {0}", GetEnvironmentValue("SYSTEMDRIVE"));
			Console.WriteLine("System Path: {0}", GetEnvironmentValue("SYSTEMROOT"));
			Console.WriteLine("Extensions: {0}", GetEnvironmentValue("PATHEXT"));

			//Should always return a security exception
			Console.WriteLine("ComputerName: {0}", GetEnvironmentValue("COMPUTERNAME"));

			Console.Write("\nPress Enter to exit...");
			Console.Read();
		}

		private static string GetEnvironmentValue(string Var) 
		{
			try 
			{
				string Val = Environment.GetEnvironmentVariable(Var);
				if (Val == null)
					return "*Not Set*";
				else
					return Val;

			} 
			catch (SecurityException) 
			{
				return "*Inadequate Permissions*";
			} 
			catch (Exception e) 
			{
				return "*Exception: " + e.Message + "*";
			}			
		}
	}
}