Retrieves all Environment Variables

EnvironmentEx.cs

using System;
using System.Collections.Generic;
using System.Threading;
using System.Runtime.InteropServices;

namespace System
{
	public static class EnvironmentEx
	{
		[DllImport("kernel32.dll", CharSet = CharSet.Ansi, SetLastError = true)]
		[return: MarshalAs(UnmanagedType.Bool)]
		private static extern bool FreeEnvironmentStringsA(IntPtr buffer);

		[DllImport("kernel32.dll", CharSet = CharSet.Ansi, SetLastError = true)]
		private static extern IntPtr GetEnvironmentStringsA();

		private static readonly Lazy<List<string>> _lazyEnvironmentVariables = new Lazy<List<string>>(
			() =>
			{
				var result = new List<string>();

				var buffer = GetEnvironmentStringsA();
				var originalBuffer = buffer;

				while (true)
				{
					var text = Marshal.PtrToStringAnsi(buffer);

					if (string.IsNullOrEmpty(text)) break;

					result.Add(text);

					buffer += (text.Length + 1);
				}

				FreeEnvironmentStringsA(originalBuffer);

				return result;
			}, LazyThreadSafetyMode.ExecutionAndPublication);

		public static IEnumerable<string> EnvironmentVariables
		{
			get
			{
				foreach (var value in _lazyEnvironmentVariables.Value)
					yield return value;
			}
		}

		public static string[] GetEnvironmentVariables()
		{
			var variables = _lazyEnvironmentVariables.Value;

			var result = new string[variables.Count];

			for (int i = 0; i < variables.Count; i++)
			{
				result[i] = variables[i];
			}

			return result;
		}
	}
}