Created a namespace System.Private.PlatformSpecific.

Added implementations in Unix.cs and Windows.cs for retrieving
environment variables in a platform specific manner.
Implementations are called from Environment.cs

svn path=/trunk/mcs/; revision=554

mcs/class/corlib/System/Unix.cs

@@ -0,0 +1,80 @@
+//------------------------------------------------------------------------------
+// 
+// System.Private.Unix.cs 
+//
+// Copyright (C) 2001 Moonlight Enterprises, All Rights Reserved
+// 
+// Author:         Jim Richardson, develop@wtfo-guru.com
+// Created:        Tuesday, August 21, 2001 
+//
+//------------------------------------------------------------------------------
+using System;
+using System.IO;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+
+namespace System
+{
+	public sealed class PlatformSpecific
+	{	
+ 		/// <summary>
+		/// Gets the standard new line value
+		/// </summary>
+		public static string NewLine
+		{
+			get
+			{
+				return "\n";
+			}
+		}
+
+		[ DllImport("libc", EntryPoint="getpid") ]
+        private extern static int getPid();
+
+		private static char[] getPidFileContents(string fileName, ref int length)
+		{
+			Int32 pid = getPid();
+			// TODO: Use a special folder define probably for the proc folder
+			string path = Path.Combine("/proc", pid.ToString());
+			path = Path.Combine(path, fileName);
+			StreamReader stream = File.OpenText(path);
+			FileInfo finfo = new FileInfo(path);
+			length = (int)finfo.Length;
+			char[] buffer = new char[length];
+			stream.Read(buffer, 0, length);
+			return buffer;
+		}
+
+		public static string getEnvironment()
+		{
+			// couldn't DllImport environ from libc because it was a 
+			// global variable not a method couldn't find another
+			// way to access unsafe globals
+			// definitely a candidate for "libmono" 
+
+			string strEnv = null;
+
+			try
+			{ 
+				int length = 0;
+				char[] arEnv = getPidFileContents("environ", ref length);
+
+				for(int i = 0; i < length - 1; i++)
+				{
+					if(arEnv[i] == '\0')
+					{
+						arEnv[i] = '\t';  // safer delimeter
+					}
+				}
+				strEnv = new string(arEnv);
+				//Console.WriteLine(str);
+			}
+			catch(Exception e)
+			{
+				Debug.WriteLine(e.ToString());
+				strEnv = null;
+			}
+			return strEnv;
+		}
+	}
+}

mcs/class/corlib/System/Windoze.cs

@@ -0,0 +1,101 @@
+//------------------------------------------------------------------------------
+// 
+// System.Private.Windows.cs 
+//
+// Copyright (C) 2001 Moonlight Enterprises, All Rights Reserved
+// 
+// Author:         Jim Richardson, develop@wtfo-guru.com
+// Created:        Tuesday, August 21, 2001 
+//
+//------------------------------------------------------------------------------
+
+using System;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+
+namespace System
+{
+	public sealed class PlatformSpecific
+	{
+ 		/// <summary>
+		/// Gets the standard new line value
+		/// </summary>
+		public static string NewLine
+		{
+			get
+			{
+				return "\r\n";
+			}
+		}
+
+		// TODO: verify the "W" versions are available on 95/98/ME
+		// or whatever other windoze platforms we'll target
+		[ DllImport("kernel32", EntryPoint="GetEnvironmentStringsW") ]
+		private extern static IntPtr getEnvironStrings();
+		[ DllImport("kernel32", EntryPoint="FreeEnvironmentStringsW") ]
+		private extern static int freeEnvironStrings(IntPtr p);	
+
+		public static string getEnvironment()
+		{
+			IntPtr pEnv = getEnvironStrings();
+			int start = 0;
+			int offset = 0;
+			int length = 0;
+			int consecutive_nulls = 0;
+			int null_count = 0;
+			char ch;
+			string strEnv = null;
+
+			try
+			{
+				// the first string is just the process identifer, etc.
+				// the array of strings ends with double (perhaps) triple null
+				// if we read too far before we reach the end an exception will
+				// surely be thrown
+				while(length == 0)
+				{
+					ch = (char)System.Runtime.InteropServices.Marshal.ReadInt16(pEnv, offset);
+
+					offset += 2;
+
+					if(ch == '\0')
+					{
+						null_count++;
+						consecutive_nulls++;
+						if(start == 0 && null_count > 1)
+						{	// we skip the first two windows strings
+							// because they aren't environment variables
+							start = offset;
+						}
+						if(consecutive_nulls > 1)
+						{	// TODO: verify this length is exactly correct
+							// this was a quickie calculation that worked
+							length = offset - (consecutive_nulls + start);
+						}
+					}
+					else
+					{
+						consecutive_nulls = 0;
+					}
+				}
+
+				char[] arEnv = new char[length];
+				int index;
+				for(offset = start, index = 0; index < length; offset += 2, index++)
+				{
+					ch = (char)System.Runtime.InteropServices.Marshal.ReadInt16(pEnv, offset);
+					arEnv[index] = ch == '\0' ? '\n' : ch;
+				}
+				strEnv = new string(arEnv);
+				//Console.WriteLine(str);
+			}
+			catch(Exception ex)
+			{
+				Debug.WriteLine(ex.ToString());
+				strEnv = null;
+			}
+			freeEnvironStrings(pEnv);
+			return strEnv;
+		}
+	}
+}