mcs/class/corlib/System/Environment.cs

   1 //------------------------------------------------------------------------------
   2 //
   3 // System.Environment.cs
   4 //
   5 // Copyright (C) 2001 Moonlight Enterprises, All Rights Reserved
   6 //
   7 // Author:         Jim Richardson, develop@wtfo-guru.com
   8 //                 Dan Lewis (dihlewis@yahoo.co.uk)
   9 // Created:        Saturday, August 11, 2001
  10 //
  11 //------------------------------------------------------------------------------
  12 //
  13 // Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
  14 //
  15 // Permission is hereby granted, free of charge, to any person obtaining
  16 // a copy of this software and associated documentation files (the
  17 // "Software"), to deal in the Software without restriction, including
  18 // without limitation the rights to use, copy, modify, merge, publish,
  19 // distribute, sublicense, and/or sell copies of the Software, and to
  20 // permit persons to whom the Software is furnished to do so, subject to
  21 // the following conditions:
  22 //
  23 // The above copyright notice and this permission notice shall be
  24 // included in all copies or substantial portions of the Software.
  25 //
  26 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  27 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  28 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  29 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  30 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  31 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  32 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  33 //
  34
  35 using System.IO;
  36 using System.Collections;
  37 using System.Runtime.CompilerServices;
  38 using System.Security;
  39 using System.Security.Permissions;
  40 using System.Text;
  41 using System.Runtime.InteropServices;
  42 using System.Threading;
  43
  44 namespace System {
  45
  46         [ComVisible (true)]
  47         public static class Environment {
  48
  49                 /*
  50                  * This is the version number of the corlib-runtime interface. When
  51                  * making changes to this interface (by changing the layout
  52                  * of classes the runtime knows about, changing icall signature or
  53                  * semantics etc), increment this variable. Also increment the
  54                  * pair of this variable in the runtime in metadata/appdomain.c.
  55                  * Changes which are already detected at runtime, like the addition
  56                  * of icalls, do not require an increment.
  57                  */
  58 #pragma warning disable 169
  59                 private const int mono_corlib_version = 110;
  60 #pragma warning restore 169
  61
  62                 [ComVisible (true)]
  63                 public enum SpecialFolder
  64                 {
  65                         MyDocuments = 0x05,
  66                         Desktop = 0x00,
  67                         MyComputer = 0x11,
  68                         Programs = 0x02,
  69                         Personal = 0x05,
  70                         Favorites = 0x06,
  71                         Startup = 0x07,
  72                         Recent = 0x08,
  73                         SendTo = 0x09,
  74                         StartMenu = 0x0b,
  75                         MyMusic = 0x0d,
  76                         DesktopDirectory = 0x10,
  77                         Templates = 0x15,
  78                         ApplicationData = 0x1a,
  79                         LocalApplicationData = 0x1c,
  80                         InternetCache = 0x20,
  81                         Cookies = 0x21,
  82                         History = 0x22,
  83                         CommonApplicationData   = 0x23,
  84                         System = 0x25,
  85                         ProgramFiles = 0x26,
  86                         MyPictures = 0x27,
  87                         CommonProgramFiles = 0x2b,
  88 #if NET_4_0
  89                         MyVideos = 0x0e,
  90 #endif
  91 #if NET_4_0
  92                         NetworkShortcuts = 0x13,
  93                         Fonts = 0x14,
  94                         CommonStartMenu = 0x16,
  95                         CommonPrograms = 0x17,
  96                         CommonStartup = 0x18,
  97                         CommonDesktopDirectory = 0x19,
  98                         PrinterShortcuts = 0x1b,
  99                         Windows = 0x24,
 100                         UserProfile = 0x28,
 101                         SystemX86 = 0x29,
 102                         ProgramFilesX86 = 0x2a,
 103                         CommonProgramFilesX86 = 0x2c,
 104                         CommonTemplates = 0x2d,
 105                         CommonDocuments = 0x2e,
 106                         CommonAdminTools = 0x2f,
 107                         AdminTools = 0x30,
 108                         CommonMusic = 0x35,
 109                         CommonPictures = 0x36,
 110                         CommonVideos = 0x37,
 111                         Resources = 0x38,
 112                         LocalizedResources = 0x39,
 113                         CommonOemLinks = 0x3a,
 114                         CDBurning = 0x3b,
 115 #endif
 116                 }
 117
 118 #if NET_4_0
 119                 public
 120 #else
 121                 internal
 122 #endif
 123                 enum SpecialFolderOption {
 124                         None = 0,
 125                         DoNotVerify = 0x4000,
 126                         Create = 0x8000
 127                 }
 128
 129                 /// <summary>
 130                 /// Gets the command line for this process
 131                 /// </summary>
 132                 public static string CommandLine {
 133                         // note: security demand inherited from calling GetCommandLineArgs
 134                         get {
 135                                 StringBuilder sb = new StringBuilder ();
 136                                 foreach (string str in GetCommandLineArgs ()) {
 137                                         bool escape = false;
 138                                         string quote = "";
 139                                         string s = str;
 140                                         for (int i = 0; i < s.Length; i++) {
 141                                                 if (quote.Length == 0 && Char.IsWhiteSpace (s [i])) {
 142                                                         quote = "\"";
 143                                                 } else if (s [i] == '"') {
 144                                                         escape = true;
 145                                                 }
 146                                         }
 147                                         if (escape && quote.Length != 0) {
 148                                                 s = s.Replace ("\"", "\\\"");
 149                                         }
 150                                         sb.AppendFormat ("{0}{1}{0} ", quote, s);
 151                                 }
 152                                 if (sb.Length > 0)
 153                                         sb.Length--;
 154                                 return sb.ToString ();
 155                         }
 156                 }
 157
 158                 /// <summary>
 159                 /// Gets or sets the current directory. Actually this is supposed to get
 160                 /// and/or set the process start directory acording to the documentation
 161                 /// but actually test revealed at beta2 it is just Getting/Setting the CurrentDirectory
 162                 /// </summary>
 163                 public static string CurrentDirectory
 164                 {
 165                         get {
 166                                 return Directory.GetCurrentDirectory ();
 167                         }
 168                         set {
 169                                 Directory.SetCurrentDirectory (value);
 170                         }
 171                 }
 172
 173 #if NET_4_5
 174                 public static int CurrentManagedThreadId {
 175                         get {
 176                                 return Thread.CurrentThread.ManagedThreadId;
 177                         }
 178                 }
 179 #endif
 180
 181                 /// <summary>
 182                 /// Gets or sets the exit code of this process
 183                 /// </summary>
 184                 public extern static int ExitCode
 185                 {
 186                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 187                         get;
 188                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 189                         set;
 190                 }
 191
 192                 static public extern bool HasShutdownStarted
 193                 {
 194                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 195                         get;
 196                 }
 197
 198
 199                 /// <summary>
 200                 /// Gets the name of the local computer
 201                 /// </summary>
 202                 public extern static string MachineName {
 203                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 204                         [EnvironmentPermission (SecurityAction.Demand, Read="COMPUTERNAME")]
 205                         [SecurityPermission (SecurityAction.Demand, UnmanagedCode=true)]
 206                         get;
 207                 }
 208
 209                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 210                 extern static string GetNewLine ();
 211
 212                 static string nl;
 213                 /// <summary>
 214                 /// Gets the standard new line value
 215                 /// </summary>
 216                 public static string NewLine {
 217                         get {
 218                                 if (nl != null)
 219                                         return nl;
 220
 221                                 nl = GetNewLine ();
 222                                 return nl;
 223                         }
 224                 }
 225
 226                 //
 227                 // Support methods and fields for OSVersion property
 228                 //
 229                 static OperatingSystem os;
 230
 231                 static extern PlatformID Platform {
 232                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 233                         get;
 234                 }
 235
 236                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 237                 internal static extern string GetOSVersionString ();
 238
 239                 /// <summary>
 240                 /// Gets the current OS version information
 241                 /// </summary>
 242                 public static OperatingSystem OSVersion {
 243                         get {
 244                                 if (os == null) {
 245                                         Version v = Version.CreateFromString (GetOSVersionString ());
 246                                         PlatformID p = Platform;
 247                                         if (p == PlatformID.MacOSX)
 248                                                 p = PlatformID.Unix;
 249                                         os = new OperatingSystem (p, v);
 250                                 }
 251                                 return os;
 252                         }
 253                 }
 254
 255                 /// <summary>
 256                 /// Get StackTrace
 257                 /// </summary>
 258                 public static string StackTrace {
 259                         [EnvironmentPermission (SecurityAction.Demand, Unrestricted=true)]
 260                         get {
 261                                 System.Diagnostics.StackTrace trace = new System.Diagnostics.StackTrace (0, true);
 262                                 return trace.ToString ();
 263                         }
 264                 }
 265 #if !NET_2_1
 266                 /// <summary>
 267                 /// Get a fully qualified path to the system directory
 268                 /// </summary>
 269                 public static string SystemDirectory {
 270                         get {
 271                                 return GetFolderPath (SpecialFolder.System);
 272                         }
 273                 }
 274 #endif
 275                 /// <summary>
 276                 /// Get the number of milliseconds that have elapsed since the system was booted
 277                 /// </summary>
 278                 public extern static int TickCount {
 279                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 280                         get;
 281                 }
 282
 283                 /// <summary>
 284                 /// Get UserDomainName
 285                 /// </summary>
 286                 public static string UserDomainName {
 287                         // FIXME: this variable doesn't exist (at least not on WinXP) - reported to MS as FDBK20562
 288                         [EnvironmentPermission (SecurityAction.Demand, Read="USERDOMAINNAME")]
 289                         get {
 290                                 return MachineName;
 291                         }
 292                 }
 293
 294                 /// <summary>
 295                 /// Gets a flag indicating whether the process is in interactive mode
 296                 /// </summary>
 297                 [MonoTODO ("Currently always returns false, regardless of interactive state")]
 298                 public static bool UserInteractive {
 299                         get {
 300                                 return false;
 301                         }
 302                 }
 303
 304                 /// <summary>
 305                 /// Get the user name of current process is running under
 306                 /// </summary>
 307                 public extern static string UserName {
 308                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 309                         [EnvironmentPermission (SecurityAction.Demand, Read="USERNAME;USER")]
 310                         get;
 311                 }
 312
 313                 /// <summary>
 314                 /// Get the version of the common language runtime
 315                 /// </summary>
 316                 public static Version Version {
 317                         get {
 318                                 return new Version (Consts.FxFileVersion);
 319                         }
 320                 }
 321
 322                 /// <summary>
 323                 /// Get the amount of physical memory mapped to process
 324                 /// </summary>
 325                 [MonoTODO ("Currently always returns zero")]
 326                 public static long WorkingSet {
 327                         [EnvironmentPermission (SecurityAction.Demand, Unrestricted=true)]
 328                         get { return 0; }
 329                 }
 330
 331                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 332                 [SecurityPermission (SecurityAction.Demand, UnmanagedCode=true)]
 333                 public extern static void Exit (int exitCode);
 334
 335                 /// <summary>
 336                 /// Substitute environment variables in the argument "name"
 337                 /// </summary>
 338                 public static string ExpandEnvironmentVariables (string name)
 339                 {
 340                         if (name == null)
 341                                 throw new ArgumentNullException ("name");
 342
 343                         int off1 = name.IndexOf ('%');
 344                         if (off1 == -1)
 345                                 return name;
 346
 347                         int len = name.Length;
 348                         int off2 = 0;
 349                         if (off1 == len - 1 || (off2 = name.IndexOf ('%', off1 + 1)) == -1)
 350                                 return name;
 351
 352                         StringBuilder result = new StringBuilder ();
 353                         result.Append (name, 0, off1);
 354                         Hashtable tbl = null;
 355                         do {
 356                                 string var = name.Substring (off1 + 1, off2 - off1 - 1);
 357                                 string value = GetEnvironmentVariable (var);
 358                                 if (value == null && Environment.IsRunningOnWindows) {
 359                                         // On windows, env. vars. are case insensitive
 360                                         if (tbl == null)
 361                                                 tbl = GetEnvironmentVariablesNoCase ();
 362
 363                                         value = tbl [var] as string;
 364                                 }
 365
 366                                 // If value not found, add %FOO to stream,
 367                                 //  and use the closing % for the next iteration.
 368                                 // If value found, expand it in place of %FOO%
 369                                 int realOldOff2 = off2;
 370                                 if (value == null) {
 371                                         result.Append ('%');
 372                                         result.Append (var);
 373                                         off2--;
 374                                 } else {
 375                                         result.Append (value);
 376                                 }
 377                                 int oldOff2 = off2;
 378                                 off1 = name.IndexOf ('%', off2 + 1);
 379                                 // If no % found for off1, don't look for one for off2
 380                                 off2 = (off1 == -1 || off2 > len-1)? -1 :name.IndexOf ('%', off1 + 1);
 381                                 // textLen is the length of text between the closing % of current iteration
 382                                 //  and the starting % of the next iteration if any. This text is added to output
 383                                 int textLen;
 384                                 // If no new % found, use all the remaining text
 385                                 if (off1 == -1 || off2 == -1)
 386                                         textLen = len - oldOff2 - 1;
 387                                 // If value found in current iteration, use text after current closing % and next %
 388                                 else if(value != null)
 389                                         textLen = off1 - oldOff2 - 1;
 390                                 // If value not found in current iteration, but a % was found for next iteration,
 391                                 //  use text from current closing % to the next %.
 392                                 else
 393                                         textLen = off1 - realOldOff2;
 394                                 if(off1 >= oldOff2 || off1 == -1)
 395                                         result.Append (name, oldOff2+1, textLen);
 396                         } while (off2 > -1 && off2 < len);
 397
 398                         return result.ToString ();
 399
 400                 }
 401
 402                 /// <summary>
 403                 /// Return an array of the command line arguments of the current process
 404                 /// </summary>
 405                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 406                 [EnvironmentPermissionAttribute (SecurityAction.Demand, Read = "PATH")]
 407                 public extern static string[] GetCommandLineArgs ();
 408
 409                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 410                 internal extern static string internalGetEnvironmentVariable (string variable);
 411
 412                 /// <summary>
 413                 /// Return a string containing the value of the environment
 414                 /// variable identifed by parameter "variable"
 415                 /// </summary>
 416                 public static string GetEnvironmentVariable (string variable)
 417                 {
 418 #if !NET_2_1
 419                         if (SecurityManager.SecurityEnabled) {
 420                                 new EnvironmentPermission (EnvironmentPermissionAccess.Read, variable).Demand ();
 421                         }
 422 #endif
 423                         return internalGetEnvironmentVariable (variable);
 424                 }
 425
 426                 static Hashtable GetEnvironmentVariablesNoCase ()
 427                 {
 428                         Hashtable vars = new Hashtable (CaseInsensitiveHashCodeProvider.Default,
 429                                                         CaseInsensitiveComparer.Default);
 430
 431                         foreach (string name in GetEnvironmentVariableNames ()) {
 432                                 vars [name] = internalGetEnvironmentVariable (name);
 433                         }
 434
 435                         return vars;
 436                 }
 437
 438                 /// <summary>
 439                 /// Return a set of all environment variables and their values
 440                 /// </summary>
 441 #if !NET_2_1
 442                 public static IDictionary GetEnvironmentVariables ()
 443                 {
 444                         StringBuilder sb = null;
 445                         if (SecurityManager.SecurityEnabled) {
 446                                 // we must have access to each variable to get the lot
 447                                 sb = new StringBuilder ();
 448                                 // but (performance-wise) we do not want a stack-walk
 449                                 // for each of them so we concatenate them
 450                         }
 451
 452                         Hashtable vars = new Hashtable ();
 453                         foreach (string name in GetEnvironmentVariableNames ()) {
 454                                 vars [name] = internalGetEnvironmentVariable (name);
 455                                 if (sb != null) {
 456                                         sb.Append (name);
 457                                         sb.Append (";");
 458                                 }
 459                         }
 460
 461                         if (sb != null) {
 462                                 new EnvironmentPermission (EnvironmentPermissionAccess.Read, sb.ToString ()).Demand ();
 463                         }
 464                         return vars;
 465                 }
 466 #else
 467                 [EnvironmentPermission (SecurityAction.Demand, Unrestricted=true)]
 468                 public static IDictionary GetEnvironmentVariables ()
 469                 {
 470                         Hashtable vars = new Hashtable ();
 471                         foreach (string name in GetEnvironmentVariableNames ()) {
 472                                 vars [name] = internalGetEnvironmentVariable (name);
 473                         }
 474                         return vars;
 475                 }
 476 #endif
 477
 478                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 479                 private extern static string GetWindowsFolderPath (int folder);
 480
 481                 /// <summary>
 482                 /// Returns the fully qualified path of the
 483                 /// folder specified by the "folder" parameter
 484                 /// </summary>
 485                 public static string GetFolderPath (SpecialFolder folder)
 486                 {
 487                         return GetFolderPath (folder, SpecialFolderOption.None);
 488                 }
 489 #if NET_4_0
 490                 public
 491 #endif
 492                 static string GetFolderPath(SpecialFolder folder, SpecialFolderOption option)
 493                 {
 494                         SecurityManager.EnsureElevatedPermissions (); // this is a no-op outside moonlight
 495
 496                         string dir = null;
 497
 498                         if (Environment.IsRunningOnWindows)
 499                                 dir = GetWindowsFolderPath ((int) folder);
 500                         else
 501                                 dir = UnixGetFolderPath (folder, option);
 502
 503 #if !NET_2_1
 504                         if ((dir != null) && (dir.Length > 0) && SecurityManager.SecurityEnabled) {
 505                                 new FileIOPermission (FileIOPermissionAccess.PathDiscovery, dir).Demand ();
 506                         }
 507 #endif
 508                         return dir;
 509                 }
 510
 511                 private static string ReadXdgUserDir (string config_dir, string home_dir, string key, string fallback)
 512                 {
 513                         string env_path = internalGetEnvironmentVariable (key);
 514                         if (env_path != null && env_path != String.Empty) {
 515                                 return env_path;
 516                         }
 517
 518                         string user_dirs_path = Path.Combine (config_dir, "user-dirs.dirs");
 519
 520                         if (!File.Exists (user_dirs_path)) {
 521                                 return Path.Combine (home_dir, fallback);
 522                         }
 523
 524                         try {
 525                                 using(StreamReader reader = new StreamReader (user_dirs_path)) {
 526                                         string line;
 527                                         while ((line = reader.ReadLine ()) != null) {
 528                                                 line = line.Trim ();
 529                                                 int delim_index = line.IndexOf ('=');
 530                                                 if(delim_index > 8 && line.Substring (0, delim_index) == key) {
 531                                                         string path = line.Substring (delim_index + 1).Trim ('"');
 532                                                         bool relative = false;
 533
 534                                                         if (path.StartsWithOrdinalUnchecked ("$HOME/")) {
 535                                                                 relative = true;
 536                                                                 path = path.Substring (6);
 537                                                         } else if (!path.StartsWithOrdinalUnchecked ("/")) {
 538                                                                 relative = true;
 539                                                         }
 540
 541                                                         return relative ? Path.Combine (home_dir, path) : path;
 542                                                 }
 543                                         }
 544                                 }
 545                         } catch (FileNotFoundException) {
 546                         }
 547
 548                         return Path.Combine (home_dir, fallback);
 549                 }
 550
 551
 552                 // the security runtime (and maybe other parts of corlib) needs the
 553                 // information to initialize themselves before permissions can be checked
 554                 internal static string UnixGetFolderPath (SpecialFolder folder, SpecialFolderOption option)
 555                 {
 556                         string home = internalGetHome ();
 557
 558                         // http://freedesktop.org/Standards/basedir-spec/basedir-spec-0.6.html
 559
 560                         // note: skip security check for environment variables
 561                         string data = internalGetEnvironmentVariable ("XDG_DATA_HOME");
 562                         if ((data == null) || (data == String.Empty)) {
 563                                 data = Path.Combine (home, ".local");
 564                                 data = Path.Combine (data, "share");
 565                         }
 566
 567                         // note: skip security check for environment variables
 568                         string config = internalGetEnvironmentVariable ("XDG_CONFIG_HOME");
 569                         if ((config == null) || (config == String.Empty)) {
 570                                 config = Path.Combine (home, ".config");
 571                         }
 572
 573                         switch (folder) {
 574                         // MyComputer is a virtual directory
 575                         case SpecialFolder.MyComputer:
 576                                 return String.Empty;
 577
 578                         // personal == ~
 579                         case SpecialFolder.Personal:
 580 #if MONOTOUCH
 581                                 return Path.Combine (home, "Documents");
 582 #else
 583                                 return home;
 584 #endif
 585                         // use FDO's CONFIG_HOME. This data will be synced across a network like the windows counterpart.
 586                         case SpecialFolder.ApplicationData:
 587 #if MONOTOUCH
 588                         {
 589                                 string dir = Path.Combine (Path.Combine (home, "Documents"), ".config");
 590                                 if (option == SpecialFolderOption.Create){
 591                                         if (!Directory.Exists (dir))
 592                                                 Directory.CreateDirectory (dir);
 593                                 }
 594                                 return dir;
 595                         }
 596 #else
 597                                 return config;
 598 #endif
 599                         //use FDO's DATA_HOME. This is *NOT* synced
 600                         case SpecialFolder.LocalApplicationData:
 601 #if MONOTOUCH
 602                         {
 603                                 string dir = Path.Combine (home, "Documents");
 604                                 if (!Directory.Exists (dir))
 605                                         Directory.CreateDirectory (dir);
 606
 607                                 return dir;
 608                         }
 609 #else
 610                                 return data;
 611 #endif
 612
 613                         case SpecialFolder.Desktop:
 614                         case SpecialFolder.DesktopDirectory:
 615                                 return ReadXdgUserDir (config, home, "XDG_DESKTOP_DIR", "Desktop");
 616
 617                         case SpecialFolder.MyMusic:
 618                                 if (Platform == PlatformID.MacOSX)
 619                                         return Path.Combine (home, "Music");
 620                                 else
 621                                         return ReadXdgUserDir (config, home, "XDG_MUSIC_DIR", "Music");
 622
 623                         case SpecialFolder.MyPictures:
 624                                 if (Platform == PlatformID.MacOSX)
 625                                         return Path.Combine (home, "Pictures");
 626                                 else
 627                                         return ReadXdgUserDir (config, home, "XDG_PICTURES_DIR", "Pictures");
 628
 629                         case SpecialFolder.Templates:
 630                                 return ReadXdgUserDir (config, home, "XDG_TEMPLATES_DIR", "Templates");
 631 #if NET_4_0
 632                         case SpecialFolder.MyVideos:
 633                                 return ReadXdgUserDir (config, home, "XDG_VIDEOS_DIR", "Videos");
 634 #endif
 635 #if NET_4_0
 636                         case SpecialFolder.CommonTemplates:
 637                                 return "/usr/share/templates";
 638                         case SpecialFolder.Fonts:
 639                                 if (Platform == PlatformID.MacOSX)
 640                                         return Path.Combine (home, "Library", "Fonts");
 641
 642                                 return Path.Combine (home, ".fonts");
 643 #endif
 644                         // these simply dont exist on Linux
 645                         // The spec says if a folder doesnt exist, we
 646                         // should return ""
 647                         case SpecialFolder.Favorites:
 648                                 if (Platform == PlatformID.MacOSX)
 649                                         return Path.Combine (home, "Library", "Favorites");
 650                                 else
 651                                         return String.Empty;
 652
 653                         case SpecialFolder.ProgramFiles:
 654                                 if (Platform == PlatformID.MacOSX)
 655                                         return "/Applications";
 656                                 else
 657                                         return String.Empty;
 658
 659                         case SpecialFolder.InternetCache:
 660                                 if (Platform == PlatformID.MacOSX)
 661                                         return Path.Combine (home, "Library", "Caches");
 662                                 else
 663                                         return String.Empty;
 664
 665 #if NET_4_0
 666                                 // #2873
 667                         case SpecialFolder.UserProfile:
 668                                 return home;
 669 #endif
 670
 671                         case SpecialFolder.Programs:
 672                         case SpecialFolder.SendTo:
 673                         case SpecialFolder.StartMenu:
 674                         case SpecialFolder.Startup:
 675                         case SpecialFolder.Cookies:
 676                         case SpecialFolder.History:
 677                         case SpecialFolder.Recent:
 678                         case SpecialFolder.CommonProgramFiles:
 679                         case SpecialFolder.System:
 680 #if NET_4_0
 681                         case SpecialFolder.NetworkShortcuts:
 682                         case SpecialFolder.CommonStartMenu:
 683                         case SpecialFolder.CommonPrograms:
 684                         case SpecialFolder.CommonStartup:
 685                         case SpecialFolder.CommonDesktopDirectory:
 686                         case SpecialFolder.PrinterShortcuts:
 687                         case SpecialFolder.Windows:
 688                         case SpecialFolder.SystemX86:
 689                         case SpecialFolder.ProgramFilesX86:
 690                         case SpecialFolder.CommonProgramFilesX86:
 691                         case SpecialFolder.CommonDocuments:
 692                         case SpecialFolder.CommonAdminTools:
 693                         case SpecialFolder.AdminTools:
 694                         case SpecialFolder.CommonMusic:
 695                         case SpecialFolder.CommonPictures:
 696                         case SpecialFolder.CommonVideos:
 697                         case SpecialFolder.Resources:
 698                         case SpecialFolder.LocalizedResources:
 699                         case SpecialFolder.CommonOemLinks:
 700                         case SpecialFolder.CDBurning:
 701 #endif
 702                                 return String.Empty;
 703                         // This is where data common to all users goes
 704                         case SpecialFolder.CommonApplicationData:
 705                                 return "/usr/share";
 706                         default:
 707                                 throw new ArgumentException ("Invalid SpecialFolder");
 708                         }
 709                 }
 710
 711
 712                 [EnvironmentPermission (SecurityAction.Demand, Unrestricted=true)]
 713                 public static string[] GetLogicalDrives ()
 714                 {
 715                         return GetLogicalDrivesInternal ();
 716                 }
 717
 718 #if !NET_2_1
 719                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 720                 private static extern void internalBroadcastSettingChange ();
 721
 722                 public static string GetEnvironmentVariable (string variable, EnvironmentVariableTarget target)
 723                 {
 724                         switch (target) {
 725                         case EnvironmentVariableTarget.Process:
 726                                 return GetEnvironmentVariable (variable);
 727                         case EnvironmentVariableTarget.Machine:
 728                                 new EnvironmentPermission (PermissionState.Unrestricted).Demand ();
 729                                 if (!IsRunningOnWindows)
 730                                         return null;
 731                                 using (Microsoft.Win32.RegistryKey env = Microsoft.Win32.Registry.LocalMachine.OpenSubKey (@"SYSTEM\CurrentControlSet\Control\Session Manager\Environment")) {
 732                                         object regvalue = env.GetValue (variable);
 733                                         return (regvalue == null) ? null : regvalue.ToString ();
 734                                 }
 735                         case EnvironmentVariableTarget.User:
 736                                 new EnvironmentPermission (PermissionState.Unrestricted).Demand ();
 737                                 if (!IsRunningOnWindows)
 738                                         return null;
 739                                 using (Microsoft.Win32.RegistryKey env = Microsoft.Win32.Registry.CurrentUser.OpenSubKey ("Environment", false)) {
 740                                         object regvalue = env.GetValue (variable);
 741                                         return (regvalue == null) ? null : regvalue.ToString ();
 742                                 }
 743                         default:
 744                                 throw new ArgumentException ("target");
 745                         }
 746                 }
 747
 748                 public static IDictionary GetEnvironmentVariables (EnvironmentVariableTarget target)
 749                 {
 750                         IDictionary variables = (IDictionary)new Hashtable ();
 751                         switch (target) {
 752                         case EnvironmentVariableTarget.Process:
 753                                 variables = GetEnvironmentVariables ();
 754                                 break;
 755                         case EnvironmentVariableTarget.Machine:
 756                                 new EnvironmentPermission (PermissionState.Unrestricted).Demand ();
 757                                 if (IsRunningOnWindows) {
 758                                         using (Microsoft.Win32.RegistryKey env = Microsoft.Win32.Registry.LocalMachine.OpenSubKey (@"SYSTEM\CurrentControlSet\Control\Session Manager\Environment")) {
 759                                                 string[] value_names = env.GetValueNames ();
 760                                                 foreach (string value_name in value_names)
 761                                                         variables.Add (value_name, env.GetValue (value_name));
 762                                         }
 763                                 }
 764                                 break;
 765                         case EnvironmentVariableTarget.User:
 766                                 new EnvironmentPermission (PermissionState.Unrestricted).Demand ();
 767                                 if (IsRunningOnWindows) {
 768                                         using (Microsoft.Win32.RegistryKey env = Microsoft.Win32.Registry.CurrentUser.OpenSubKey ("Environment")) {
 769                                                 string[] value_names = env.GetValueNames ();
 770                                                 foreach (string value_name in value_names)
 771                                                         variables.Add (value_name, env.GetValue (value_name));
 772                                         }
 773                                 }
 774                                 break;
 775                         default:
 776                                 throw new ArgumentException ("target");
 777                         }
 778                         return variables;
 779                 }
 780
 781                 [EnvironmentPermission (SecurityAction.Demand, Unrestricted=true)]
 782                 public static void SetEnvironmentVariable (string variable, string value)
 783                 {
 784                         SetEnvironmentVariable (variable, value, EnvironmentVariableTarget.Process);
 785                 }
 786
 787                 [EnvironmentPermission (SecurityAction.Demand, Unrestricted = true)]
 788                 public static void SetEnvironmentVariable (string variable, string value, EnvironmentVariableTarget target)
 789                 {
 790                         if (variable == null)
 791                                 throw new ArgumentNullException ("variable");
 792                         if (variable == String.Empty)
 793                                 throw new ArgumentException ("String cannot be of zero length.", "variable");
 794                         if (variable.IndexOf ('=') != -1)
 795                                 throw new ArgumentException ("Environment variable name cannot contain an equal character.", "variable");
 796                         if (variable[0] == '\0')
 797                                 throw new ArgumentException ("The first char in the string is the null character.", "variable");
 798
 799                         switch (target) {
 800                         case EnvironmentVariableTarget.Process:
 801                                 InternalSetEnvironmentVariable (variable, value);
 802                                 break;
 803                         case EnvironmentVariableTarget.Machine:
 804                                 if (!IsRunningOnWindows)
 805                                         return;
 806                                 using (Microsoft.Win32.RegistryKey env = Microsoft.Win32.Registry.LocalMachine.OpenSubKey (@"SYSTEM\CurrentControlSet\Control\Session Manager\Environment", true)) {
 807                                         if (String.IsNullOrEmpty (value))
 808                                                 env.DeleteValue (variable, false);
 809                                         else
 810                                                 env.SetValue (variable, value);
 811                                         internalBroadcastSettingChange ();
 812                                 }
 813                                 break;
 814                         case EnvironmentVariableTarget.User:
 815                                 if (!IsRunningOnWindows)
 816                                         return;
 817                                 using (Microsoft.Win32.RegistryKey env = Microsoft.Win32.Registry.CurrentUser.OpenSubKey ("Environment", true)) {
 818                                         if (String.IsNullOrEmpty (value))
 819                                                 env.DeleteValue (variable, false);
 820                                         else
 821                                                 env.SetValue (variable, value);
 822                                         internalBroadcastSettingChange ();
 823                                 }
 824                                 break;
 825                         default:
 826                                 throw new ArgumentException ("target");
 827                         }
 828                 }
 829
 830                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 831                 internal static extern void InternalSetEnvironmentVariable (string variable, string value);
 832 #endif
 833                 [SecurityPermission (SecurityAction.LinkDemand, UnmanagedCode=true)]
 834                 public static void FailFast (string message)
 835                 {
 836                         throw new NotImplementedException ();
 837                 }
 838
 839 #if NET_4_0
 840                 [SecurityCritical]
 841                 public static void FailFast (string message, Exception exception)
 842                 {
 843                         throw new NotImplementedException ();
 844                 }
 845 #endif
 846
 847 #if NET_4_0
 848                 public static bool Is64BitOperatingSystem {
 849                         get { return IntPtr.Size == 8; } // FIXME: is this good enough?
 850                 }
 851
 852                 public static int SystemPageSize {
 853                         get { return GetPageSize (); }
 854                 }
 855 #endif
 856
 857 #if NET_4_0
 858                 public
 859 #else
 860                 internal
 861 #endif
 862                 static bool Is64BitProcess {
 863                         get { return IntPtr.Size == 8; }
 864                 }
 865
 866                 public static extern int ProcessorCount {
 867                         [EnvironmentPermission (SecurityAction.Demand, Read="NUMBER_OF_PROCESSORS")]
 868                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 869                         get;
 870                 }
 871
 872                 // private methods
 873 #if MOBILE
 874                 internal const bool IsRunningOnWindows = false;
 875 #else
 876                 internal static bool IsRunningOnWindows {
 877                         get { return ((int) Platform < 4); }
 878                 }
 879 #endif
 880
 881 #if !NET_2_1
 882                 //
 883                 // Used by gacutil.exe
 884                 //
 885 #pragma warning disable 169
 886                 private static string GacPath {
 887                         get {
 888                                 if (Environment.IsRunningOnWindows) {
 889                                         /* On windows, we don't know the path where mscorlib.dll will be installed */
 890                                         string corlibDir = new DirectoryInfo (Path.GetDirectoryName (typeof (int).Assembly.Location)).Parent.Parent.FullName;
 891                                         return Path.Combine (Path.Combine (corlibDir, "mono"), "gac");
 892                                 }
 893
 894                                 return Path.Combine (Path.Combine (internalGetGacPath (), "mono"), "gac");
 895                         }
 896                 }
 897 #pragma warning restore 169
 898                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 899                 internal extern static string internalGetGacPath ();
 900 #endif
 901                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 902                 private extern static string [] GetLogicalDrivesInternal ();
 903
 904                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 905                 private extern static string [] GetEnvironmentVariableNames ();
 906
 907                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 908                 internal extern static string GetMachineConfigPath ();
 909
 910                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 911                 internal extern static string internalGetHome ();
 912
 913                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 914                 internal extern static int GetPageSize ();
 915
 916                 static internal bool IsUnix {
 917                         get {
 918                                 int platform = (int) Environment.Platform;
 919
 920                                 return (platform == 4 || platform == 128 || platform == 6);
 921                         }
 922                 }
 923                 static internal bool IsMacOS {
 924                         get {
 925                                 return Environment.Platform == PlatformID.MacOSX;
 926                         }
 927                 }
 928         }
 929 }
 930