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 using System.Diagnostics.Contracts;
  44
  45 namespace System {
  46
  47         [ComVisible (true)]
  48         public static partial class Environment {
  49
  50                 /*
  51                  * This is the version number of the corlib-runtime interface. When
  52                  * making changes to this interface (by changing the layout
  53                  * of classes the runtime knows about, changing icall signature or
  54                  * semantics etc), increment this variable. Also increment the
  55                  * pair of this variable in the runtime in metadata/appdomain.c.
  56                  * Changes which are already detected at runtime, like the addition
  57                  * of icalls, do not require an increment.
  58                  */
  59 #pragma warning disable 169
  60                 private const int mono_corlib_version = 139;
  61 #pragma warning restore 169
  62
  63                 [ComVisible (true)]
  64                 public enum SpecialFolder
  65                 {
  66                         MyDocuments = 0x05,
  67                         Desktop = 0x00,
  68                         MyComputer = 0x11,
  69                         Programs = 0x02,
  70                         Personal = 0x05,
  71                         Favorites = 0x06,
  72                         Startup = 0x07,
  73                         Recent = 0x08,
  74                         SendTo = 0x09,
  75                         StartMenu = 0x0b,
  76                         MyMusic = 0x0d,
  77                         DesktopDirectory = 0x10,
  78                         Templates = 0x15,
  79                         ApplicationData = 0x1a,
  80                         LocalApplicationData = 0x1c,
  81                         InternetCache = 0x20,
  82                         Cookies = 0x21,
  83                         History = 0x22,
  84                         CommonApplicationData   = 0x23,
  85                         System = 0x25,
  86                         ProgramFiles = 0x26,
  87                         MyPictures = 0x27,
  88                         CommonProgramFiles = 0x2b,
  89                         MyVideos = 0x0e,
  90                         NetworkShortcuts = 0x13,
  91                         Fonts = 0x14,
  92                         CommonStartMenu = 0x16,
  93                         CommonPrograms = 0x17,
  94                         CommonStartup = 0x18,
  95                         CommonDesktopDirectory = 0x19,
  96                         PrinterShortcuts = 0x1b,
  97                         Windows = 0x24,
  98                         UserProfile = 0x28,
  99                         SystemX86 = 0x29,
 100                         ProgramFilesX86 = 0x2a,
 101                         CommonProgramFilesX86 = 0x2c,
 102                         CommonTemplates = 0x2d,
 103                         CommonDocuments = 0x2e,
 104                         CommonAdminTools = 0x2f,
 105                         AdminTools = 0x30,
 106                         CommonMusic = 0x35,
 107                         CommonPictures = 0x36,
 108                         CommonVideos = 0x37,
 109                         Resources = 0x38,
 110                         LocalizedResources = 0x39,
 111                         CommonOemLinks = 0x3a,
 112                         CDBurning = 0x3b,
 113                 }
 114
 115                 public
 116                 enum SpecialFolderOption {
 117                         None = 0,
 118                         DoNotVerify = 0x4000,
 119                         Create = 0x8000
 120                 }
 121
 122                 /// <summary>
 123                 /// Gets the command line for this process
 124                 /// </summary>
 125                 public static string CommandLine {
 126                         // note: security demand inherited from calling GetCommandLineArgs
 127                         get {
 128                                 StringBuilder sb = new StringBuilder ();
 129                                 foreach (string str in GetCommandLineArgs ()) {
 130                                         bool escape = false;
 131                                         string quote = "";
 132                                         string s = str;
 133                                         for (int i = 0; i < s.Length; i++) {
 134                                                 if (quote.Length == 0 && Char.IsWhiteSpace (s [i])) {
 135                                                         quote = "\"";
 136                                                 } else if (s [i] == '"') {
 137                                                         escape = true;
 138                                                 }
 139                                         }
 140                                         if (escape && quote.Length != 0) {
 141                                                 s = s.Replace ("\"", "\\\"");
 142                                         }
 143                                         sb.AppendFormat ("{0}{1}{0} ", quote, s);
 144                                 }
 145                                 if (sb.Length > 0)
 146                                         sb.Length--;
 147                                 return sb.ToString ();
 148                         }
 149                 }
 150
 151                 /// <summary>
 152                 /// Gets or sets the current directory. Actually this is supposed to get
 153                 /// and/or set the process start directory acording to the documentation
 154                 /// but actually test revealed at beta2 it is just Getting/Setting the CurrentDirectory
 155                 /// </summary>
 156                 public static string CurrentDirectory
 157                 {
 158                         get {
 159                                 return Directory.GetCurrentDirectory ();
 160                         }
 161                         set {
 162                                 Directory.SetCurrentDirectory (value);
 163                         }
 164                 }
 165
 166                 public static int CurrentManagedThreadId {
 167                         get {
 168                                 return Thread.CurrentThread.ManagedThreadId;
 169                         }
 170                 }
 171
 172                 /// <summary>
 173                 /// Gets or sets the exit code of this process
 174                 /// </summary>
 175                 public extern static int ExitCode
 176                 {
 177                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 178                         get;
 179                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 180                         set;
 181                 }
 182
 183                 static public extern bool HasShutdownStarted
 184                 {
 185                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 186                         get;
 187                 }
 188
 189
 190                 /// <summary>
 191                 /// Gets the name of the local computer
 192                 /// </summary>
 193                 public extern static string MachineName {
 194                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 195                         [EnvironmentPermission (SecurityAction.Demand, Read="COMPUTERNAME")]
 196                         [SecurityPermission (SecurityAction.Demand, UnmanagedCode=true)]
 197                         get;
 198                 }
 199
 200                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 201                 extern static string GetNewLine ();
 202
 203                 static string nl;
 204                 /// <summary>
 205                 /// Gets the standard new line value
 206                 /// </summary>
 207                 public static string NewLine {
 208                         get {
 209                                 if (nl != null)
 210                                         return nl;
 211
 212                                 nl = GetNewLine ();
 213                                 return nl;
 214                         }
 215                 }
 216
 217                 //
 218                 // Support methods and fields for OSVersion property
 219                 //
 220                 static OperatingSystem os;
 221
 222                 static extern PlatformID Platform {
 223                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 224                         get;
 225                 }
 226
 227                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 228                 internal static extern string GetOSVersionString ();
 229
 230                 /// <summary>
 231                 /// Gets the current OS version information
 232                 /// </summary>
 233                 public static OperatingSystem OSVersion {
 234                         get {
 235                                 if (os == null) {
 236                                         Version v = CreateVersionFromString (GetOSVersionString ());
 237                                         PlatformID p = Platform;
 238                                         if (p == PlatformID.MacOSX)
 239                                                 p = PlatformID.Unix;
 240                                         os = new OperatingSystem (p, v);
 241                                 }
 242                                 return os;
 243                         }
 244                 }
 245
 246
 247                 // a very gentle way to construct a Version object which takes
 248                 // the first four numbers in a string as the version
 249                 internal static Version CreateVersionFromString (string info)
 250                 {
 251                         int major = 0;
 252                         int minor = 0;
 253                         int build = 0;
 254                         int revision = 0;
 255                         int state = 1;
 256                         int number = -1; // string may not begin with a digit
 257
 258                         if (info == null)
 259                                 return new Version (0, 0, 0, 0);
 260
 261                         for (int i=0; i < info.Length; i++) {
 262                                 char c = info [i];
 263                                 if (Char.IsDigit (c)) {
 264                                         if (number < 0) {
 265                                                 number = (c - '0');
 266                                         }
 267                                         else {
 268                                                 number = (number * 10) + (c - '0');
 269                                         }
 270                                 }
 271                                 else if (number >= 0) {
 272                                         // assign
 273                                         switch (state) {
 274                                         case 1:
 275                                                 major = number;
 276                                                 break;
 277                                         case 2:
 278                                                 minor = number;
 279                                                 break;
 280                                         case 3:
 281                                                 build = number;
 282                                                 break;
 283                                         case 4:
 284                                                 revision = number;
 285                                                 break;
 286                                         }
 287                                         number = -1;
 288                                         state ++;
 289                                 }
 290                                 // ignore end of string
 291                                 if (state == 5)
 292                                         break;
 293                         }
 294
 295                         // Last number
 296                         if (number >= 0) {
 297                                 switch (state) {
 298                                 case 1:
 299                                         major = number;
 300                                         break;
 301                                 case 2:
 302                                         minor = number;
 303                                         break;
 304                                 case 3:
 305                                         build = number;
 306                                         break;
 307                                 case 4:
 308                                         revision = number;
 309                                         break;
 310                                 }
 311                         }
 312                         return new Version (major, minor, build, revision);
 313                 }
 314
 315                 /// <summary>
 316                 /// Get StackTrace
 317                 /// </summary>
 318                 public static string StackTrace {
 319                         [EnvironmentPermission (SecurityAction.Demand, Unrestricted=true)]
 320                         get {
 321                                 System.Diagnostics.StackTrace trace = new System.Diagnostics.StackTrace (0, true);
 322                                 return trace.ToString ();
 323                         }
 324                 }
 325 #if !NET_2_1
 326                 /// <summary>
 327                 /// Get a fully qualified path to the system directory
 328                 /// </summary>
 329                 public static string SystemDirectory {
 330                         get {
 331                                 return GetFolderPath (SpecialFolder.System);
 332                         }
 333                 }
 334 #endif
 335                 /// <summary>
 336                 /// Get the number of milliseconds that have elapsed since the system was booted
 337                 /// </summary>
 338                 public extern static int TickCount {
 339                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 340                         get;
 341                 }
 342
 343                 /// <summary>
 344                 /// Get UserDomainName
 345                 /// </summary>
 346                 public static string UserDomainName {
 347                         // FIXME: this variable doesn't exist (at least not on WinXP) - reported to MS as FDBK20562
 348                         [EnvironmentPermission (SecurityAction.Demand, Read="USERDOMAINNAME")]
 349                         get {
 350                                 return MachineName;
 351                         }
 352                 }
 353
 354                 /// <summary>
 355                 /// Gets a flag indicating whether the process is in interactive mode
 356                 /// </summary>
 357                 [MonoTODO ("Currently always returns false, regardless of interactive state")]
 358                 public static bool UserInteractive {
 359                         get {
 360                                 return false;
 361                         }
 362                 }
 363
 364                 /// <summary>
 365                 /// Get the user name of current process is running under
 366                 /// </summary>
 367                 public extern static string UserName {
 368                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 369                         [EnvironmentPermission (SecurityAction.Demand, Read="USERNAME;USER")]
 370                         get;
 371                 }
 372
 373                 /// <summary>
 374                 /// Get the version of the common language runtime
 375                 /// </summary>
 376                 public static Version Version {
 377                         get {
 378                                 return new Version (Consts.FxFileVersion);
 379                         }
 380                 }
 381
 382                 /// <summary>
 383                 /// Get the amount of physical memory mapped to process
 384                 /// </summary>
 385                 [MonoTODO ("Currently always returns zero")]
 386                 public static long WorkingSet {
 387                         [EnvironmentPermission (SecurityAction.Demand, Unrestricted=true)]
 388                         get { return 0; }
 389                 }
 390
 391                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 392                 [SecurityPermission (SecurityAction.Demand, UnmanagedCode=true)]
 393                 public extern static void Exit (int exitCode);
 394
 395                 internal static void _Exit (int exitCode)
 396                 {
 397                         Exit (exitCode);
 398                 }
 399
 400                 /// <summary>
 401                 /// Substitute environment variables in the argument "name"
 402                 /// </summary>
 403                 public static string ExpandEnvironmentVariables (string name)
 404                 {
 405                         if (name == null)
 406                                 throw new ArgumentNullException ("name");
 407
 408                         int off1 = name.IndexOf ('%');
 409                         if (off1 == -1)
 410                                 return name;
 411
 412                         int len = name.Length;
 413                         int off2 = 0;
 414                         if (off1 == len - 1 || (off2 = name.IndexOf ('%', off1 + 1)) == -1)
 415                                 return name;
 416
 417                         StringBuilder result = new StringBuilder ();
 418                         result.Append (name, 0, off1);
 419                         Hashtable tbl = null;
 420                         do {
 421                                 string var = name.Substring (off1 + 1, off2 - off1 - 1);
 422                                 string value = GetEnvironmentVariable (var);
 423                                 if (value == null && Environment.IsRunningOnWindows) {
 424                                         // On windows, env. vars. are case insensitive
 425                                         if (tbl == null)
 426                                                 tbl = GetEnvironmentVariablesNoCase ();
 427
 428                                         value = tbl [var] as string;
 429                                 }
 430
 431                                 // If value not found, add %FOO to stream,
 432                                 //  and use the closing % for the next iteration.
 433                                 // If value found, expand it in place of %FOO%
 434                                 int realOldOff2 = off2;
 435                                 if (value == null) {
 436                                         result.Append ('%');
 437                                         result.Append (var);
 438                                         off2--;
 439                                 } else {
 440                                         result.Append (value);
 441                                 }
 442                                 int oldOff2 = off2;
 443                                 off1 = name.IndexOf ('%', off2 + 1);
 444                                 // If no % found for off1, don't look for one for off2
 445                                 off2 = (off1 == -1 || off2 > len-1)? -1 :name.IndexOf ('%', off1 + 1);
 446                                 // textLen is the length of text between the closing % of current iteration
 447                                 //  and the starting % of the next iteration if any. This text is added to output
 448                                 int textLen;
 449                                 // If no new % found, use all the remaining text
 450                                 if (off1 == -1 || off2 == -1)
 451                                         textLen = len - oldOff2 - 1;
 452                                 // If value found in current iteration, use text after current closing % and next %
 453                                 else if(value != null)
 454                                         textLen = off1 - oldOff2 - 1;
 455                                 // If value not found in current iteration, but a % was found for next iteration,
 456                                 //  use text from current closing % to the next %.
 457                                 else
 458                                         textLen = off1 - realOldOff2;
 459                                 if(off1 >= oldOff2 || off1 == -1)
 460                                         result.Append (name, oldOff2+1, textLen);
 461                         } while (off2 > -1 && off2 < len);
 462
 463                         return result.ToString ();
 464
 465                 }
 466
 467                 /// <summary>
 468                 /// Return an array of the command line arguments of the current process
 469                 /// </summary>
 470                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 471                 [EnvironmentPermissionAttribute (SecurityAction.Demand, Read = "PATH")]
 472                 public extern static string[] GetCommandLineArgs ();
 473
 474                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 475                 internal extern static string internalGetEnvironmentVariable (string variable);
 476
 477                 /// <summary>
 478                 /// Return a string containing the value of the environment
 479                 /// variable identifed by parameter "variable"
 480                 /// </summary>
 481                 public static string GetEnvironmentVariable (string variable)
 482                 {
 483 #if !NET_2_1
 484                         if (SecurityManager.SecurityEnabled) {
 485                                 new EnvironmentPermission (EnvironmentPermissionAccess.Read, variable).Demand ();
 486                         }
 487 #endif
 488                         return internalGetEnvironmentVariable (variable);
 489                 }
 490
 491                 static Hashtable GetEnvironmentVariablesNoCase ()
 492                 {
 493                         Hashtable vars = new Hashtable (CaseInsensitiveHashCodeProvider.Default,
 494                                                         CaseInsensitiveComparer.Default);
 495
 496                         foreach (string name in GetEnvironmentVariableNames ()) {
 497                                 vars [name] = internalGetEnvironmentVariable (name);
 498                         }
 499
 500                         return vars;
 501                 }
 502
 503                 /// <summary>
 504                 /// Return a set of all environment variables and their values
 505                 /// </summary>
 506 #if !NET_2_1
 507                 public static IDictionary GetEnvironmentVariables ()
 508                 {
 509                         StringBuilder sb = null;
 510                         if (SecurityManager.SecurityEnabled) {
 511                                 // we must have access to each variable to get the lot
 512                                 sb = new StringBuilder ();
 513                                 // but (performance-wise) we do not want a stack-walk
 514                                 // for each of them so we concatenate them
 515                         }
 516
 517                         Hashtable vars = new Hashtable ();
 518                         foreach (string name in GetEnvironmentVariableNames ()) {
 519                                 vars [name] = internalGetEnvironmentVariable (name);
 520                                 if (sb != null) {
 521                                         sb.Append (name);
 522                                         sb.Append (";");
 523                                 }
 524                         }
 525
 526                         if (sb != null) {
 527                                 new EnvironmentPermission (EnvironmentPermissionAccess.Read, sb.ToString ()).Demand ();
 528                         }
 529                         return vars;
 530                 }
 531 #else
 532                 [EnvironmentPermission (SecurityAction.Demand, Unrestricted=true)]
 533                 public static IDictionary GetEnvironmentVariables ()
 534                 {
 535                         Hashtable vars = new Hashtable ();
 536                         foreach (string name in GetEnvironmentVariableNames ()) {
 537                                 vars [name] = internalGetEnvironmentVariable (name);
 538                         }
 539                         return vars;
 540                 }
 541 #endif
 542
 543                 /// <summary>
 544                 /// Returns the fully qualified path of the
 545                 /// folder specified by the "folder" parameter
 546                 /// </summary>
 547                 public static string GetFolderPath (SpecialFolder folder)
 548                 {
 549                         return GetFolderPath (folder, SpecialFolderOption.None);
 550                 }
 551
 552 // for monotouch, not monotouch_runtime
 553 #if !(MONOTOUCH && FULL_AOT_RUNTIME)
 554                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 555                 private extern static string GetWindowsFolderPath (int folder);
 556
 557                 public
 558                 static string GetFolderPath(SpecialFolder folder, SpecialFolderOption option)
 559                 {
 560                         SecurityManager.EnsureElevatedPermissions (); // this is a no-op outside moonlight
 561
 562                         string dir = null;
 563
 564                         if (Environment.IsRunningOnWindows)
 565                                 dir = GetWindowsFolderPath ((int) folder);
 566                         else
 567                                 dir = UnixGetFolderPath (folder, option);
 568
 569 #if !NET_2_1
 570                         if ((dir != null) && (dir.Length > 0) && SecurityManager.SecurityEnabled) {
 571                                 new FileIOPermission (FileIOPermissionAccess.PathDiscovery, dir).Demand ();
 572                         }
 573 #endif
 574                         return dir;
 575                 }
 576
 577                 private static string ReadXdgUserDir (string config_dir, string home_dir, string key, string fallback)
 578                 {
 579                         string env_path = internalGetEnvironmentVariable (key);
 580                         if (env_path != null && env_path != String.Empty) {
 581                                 return env_path;
 582                         }
 583
 584                         string user_dirs_path = Path.Combine (config_dir, "user-dirs.dirs");
 585
 586                         if (!File.Exists (user_dirs_path)) {
 587                                 return Path.Combine (home_dir, fallback);
 588                         }
 589
 590                         try {
 591                                 using(StreamReader reader = new StreamReader (user_dirs_path)) {
 592                                         string line;
 593                                         while ((line = reader.ReadLine ()) != null) {
 594                                                 line = line.Trim ();
 595                                                 int delim_index = line.IndexOf ('=');
 596                                                 if(delim_index > 8 && line.Substring (0, delim_index) == key) {
 597                                                         string path = line.Substring (delim_index + 1).Trim ('"');
 598                                                         bool relative = false;
 599
 600                                                         if (path.StartsWithOrdinalUnchecked ("$HOME/")) {
 601                                                                 relative = true;
 602                                                                 path = path.Substring (6);
 603                                                         } else if (!path.StartsWithOrdinalUnchecked ("/")) {
 604                                                                 relative = true;
 605                                                         }
 606
 607                                                         return relative ? Path.Combine (home_dir, path) : path;
 608                                                 }
 609                                         }
 610                                 }
 611                         } catch (FileNotFoundException) {
 612                         }
 613
 614                         return Path.Combine (home_dir, fallback);
 615                 }
 616
 617
 618                 // the security runtime (and maybe other parts of corlib) needs the
 619                 // information to initialize themselves before permissions can be checked
 620                 internal static string UnixGetFolderPath (SpecialFolder folder, SpecialFolderOption option)
 621                 {
 622                         string home = internalGetHome ();
 623
 624                         // http://freedesktop.org/Standards/basedir-spec/basedir-spec-0.6.html
 625
 626                         // note: skip security check for environment variables
 627                         string data = internalGetEnvironmentVariable ("XDG_DATA_HOME");
 628                         if ((data == null) || (data == String.Empty)) {
 629                                 data = Path.Combine (home, ".local");
 630                                 data = Path.Combine (data, "share");
 631                         }
 632
 633                         // note: skip security check for environment variables
 634                         string config = internalGetEnvironmentVariable ("XDG_CONFIG_HOME");
 635                         if ((config == null) || (config == String.Empty)) {
 636                                 config = Path.Combine (home, ".config");
 637                         }
 638
 639                         switch (folder) {
 640                         // MyComputer is a virtual directory
 641                         case SpecialFolder.MyComputer:
 642                                 return String.Empty;
 643
 644                         // personal == ~
 645                         case SpecialFolder.Personal:
 646                                 return home;
 647
 648                         // use FDO's CONFIG_HOME. This data will be synced across a network like the windows counterpart.
 649                         case SpecialFolder.ApplicationData:
 650                                 return config;
 651
 652                         //use FDO's DATA_HOME. This is *NOT* synced
 653                         case SpecialFolder.LocalApplicationData:
 654                                 return data;
 655
 656                         case SpecialFolder.Desktop:
 657                         case SpecialFolder.DesktopDirectory:
 658                                 return ReadXdgUserDir (config, home, "XDG_DESKTOP_DIR", "Desktop");
 659
 660                         case SpecialFolder.MyMusic:
 661                                 if (Platform == PlatformID.MacOSX)
 662                                         return Path.Combine (home, "Music");
 663                                 else
 664                                         return ReadXdgUserDir (config, home, "XDG_MUSIC_DIR", "Music");
 665
 666                         case SpecialFolder.MyPictures:
 667                                 if (Platform == PlatformID.MacOSX)
 668                                         return Path.Combine (home, "Pictures");
 669                                 else
 670                                         return ReadXdgUserDir (config, home, "XDG_PICTURES_DIR", "Pictures");
 671
 672                         case SpecialFolder.Templates:
 673                                 return ReadXdgUserDir (config, home, "XDG_TEMPLATES_DIR", "Templates");
 674                         case SpecialFolder.MyVideos:
 675                                 return ReadXdgUserDir (config, home, "XDG_VIDEOS_DIR", "Videos");
 676                         case SpecialFolder.CommonTemplates:
 677                                 return "/usr/share/templates";
 678                         case SpecialFolder.Fonts:
 679                                 if (Platform == PlatformID.MacOSX)
 680                                         return Path.Combine (home, "Library", "Fonts");
 681
 682                                 return Path.Combine (home, ".fonts");
 683                         // these simply dont exist on Linux
 684                         // The spec says if a folder doesnt exist, we
 685                         // should return ""
 686                         case SpecialFolder.Favorites:
 687                                 if (Platform == PlatformID.MacOSX)
 688                                         return Path.Combine (home, "Library", "Favorites");
 689                                 else
 690                                         return String.Empty;
 691
 692                         case SpecialFolder.ProgramFiles:
 693                                 if (Platform == PlatformID.MacOSX)
 694                                         return "/Applications";
 695                                 else
 696                                         return String.Empty;
 697
 698                         case SpecialFolder.InternetCache:
 699                                 if (Platform == PlatformID.MacOSX)
 700                                         return Path.Combine (home, "Library", "Caches");
 701                                 else
 702                                         return String.Empty;
 703
 704                                 // #2873
 705                         case SpecialFolder.UserProfile:
 706                                 return home;
 707
 708                         case SpecialFolder.Programs:
 709                         case SpecialFolder.SendTo:
 710                         case SpecialFolder.StartMenu:
 711                         case SpecialFolder.Startup:
 712                         case SpecialFolder.Cookies:
 713                         case SpecialFolder.History:
 714                         case SpecialFolder.Recent:
 715                         case SpecialFolder.CommonProgramFiles:
 716                         case SpecialFolder.System:
 717                         case SpecialFolder.NetworkShortcuts:
 718                         case SpecialFolder.CommonStartMenu:
 719                         case SpecialFolder.CommonPrograms:
 720                         case SpecialFolder.CommonStartup:
 721                         case SpecialFolder.CommonDesktopDirectory:
 722                         case SpecialFolder.PrinterShortcuts:
 723                         case SpecialFolder.Windows:
 724                         case SpecialFolder.SystemX86:
 725                         case SpecialFolder.ProgramFilesX86:
 726                         case SpecialFolder.CommonProgramFilesX86:
 727                         case SpecialFolder.CommonDocuments:
 728                         case SpecialFolder.CommonAdminTools:
 729                         case SpecialFolder.AdminTools:
 730                         case SpecialFolder.CommonMusic:
 731                         case SpecialFolder.CommonPictures:
 732                         case SpecialFolder.CommonVideos:
 733                         case SpecialFolder.Resources:
 734                         case SpecialFolder.LocalizedResources:
 735                         case SpecialFolder.CommonOemLinks:
 736                         case SpecialFolder.CDBurning:
 737                                 return String.Empty;
 738                         // This is where data common to all users goes
 739                         case SpecialFolder.CommonApplicationData:
 740                                 return "/usr/share";
 741                         default:
 742                                 throw new ArgumentException ("Invalid SpecialFolder");
 743                         }
 744                 }
 745 #endif
 746
 747
 748                 [EnvironmentPermission (SecurityAction.Demand, Unrestricted=true)]
 749                 public static string[] GetLogicalDrives ()
 750                 {
 751                         return GetLogicalDrivesInternal ();
 752                 }
 753
 754 #if !MOBILE
 755                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 756                 private static extern void internalBroadcastSettingChange ();
 757
 758                 public static string GetEnvironmentVariable (string variable, EnvironmentVariableTarget target)
 759                 {
 760                         switch (target) {
 761                         case EnvironmentVariableTarget.Process:
 762                                 return GetEnvironmentVariable (variable);
 763                         case EnvironmentVariableTarget.Machine:
 764                                 new EnvironmentPermission (PermissionState.Unrestricted).Demand ();
 765                                 if (!IsRunningOnWindows)
 766                                         return null;
 767                                 using (Microsoft.Win32.RegistryKey env = Microsoft.Win32.Registry.LocalMachine.OpenSubKey (@"SYSTEM\CurrentControlSet\Control\Session Manager\Environment")) {
 768                                         object regvalue = env.GetValue (variable);
 769                                         return (regvalue == null) ? null : regvalue.ToString ();
 770                                 }
 771                         case EnvironmentVariableTarget.User:
 772                                 new EnvironmentPermission (PermissionState.Unrestricted).Demand ();
 773                                 if (!IsRunningOnWindows)
 774                                         return null;
 775                                 using (Microsoft.Win32.RegistryKey env = Microsoft.Win32.Registry.CurrentUser.OpenSubKey ("Environment", false)) {
 776                                         object regvalue = env.GetValue (variable);
 777                                         return (regvalue == null) ? null : regvalue.ToString ();
 778                                 }
 779                         default:
 780                                 throw new ArgumentException ("target");
 781                         }
 782                 }
 783
 784                 public static IDictionary GetEnvironmentVariables (EnvironmentVariableTarget target)
 785                 {
 786                         IDictionary variables = (IDictionary)new Hashtable ();
 787                         switch (target) {
 788                         case EnvironmentVariableTarget.Process:
 789                                 variables = GetEnvironmentVariables ();
 790                                 break;
 791                         case EnvironmentVariableTarget.Machine:
 792                                 new EnvironmentPermission (PermissionState.Unrestricted).Demand ();
 793                                 if (IsRunningOnWindows) {
 794                                         using (Microsoft.Win32.RegistryKey env = Microsoft.Win32.Registry.LocalMachine.OpenSubKey (@"SYSTEM\CurrentControlSet\Control\Session Manager\Environment")) {
 795                                                 string[] value_names = env.GetValueNames ();
 796                                                 foreach (string value_name in value_names)
 797                                                         variables.Add (value_name, env.GetValue (value_name));
 798                                         }
 799                                 }
 800                                 break;
 801                         case EnvironmentVariableTarget.User:
 802                                 new EnvironmentPermission (PermissionState.Unrestricted).Demand ();
 803                                 if (IsRunningOnWindows) {
 804                                         using (Microsoft.Win32.RegistryKey env = Microsoft.Win32.Registry.CurrentUser.OpenSubKey ("Environment")) {
 805                                                 string[] value_names = env.GetValueNames ();
 806                                                 foreach (string value_name in value_names)
 807                                                         variables.Add (value_name, env.GetValue (value_name));
 808                                         }
 809                                 }
 810                                 break;
 811                         default:
 812                                 throw new ArgumentException ("target");
 813                         }
 814                         return variables;
 815                 }
 816
 817                 [EnvironmentPermission (SecurityAction.Demand, Unrestricted=true)]
 818                 public static void SetEnvironmentVariable (string variable, string value)
 819                 {
 820                         SetEnvironmentVariable (variable, value, EnvironmentVariableTarget.Process);
 821                 }
 822
 823                 [EnvironmentPermission (SecurityAction.Demand, Unrestricted = true)]
 824                 public static void SetEnvironmentVariable (string variable, string value, EnvironmentVariableTarget target)
 825                 {
 826                         if (variable == null)
 827                                 throw new ArgumentNullException ("variable");
 828                         if (variable == String.Empty)
 829                                 throw new ArgumentException ("String cannot be of zero length.", "variable");
 830                         if (variable.IndexOf ('=') != -1)
 831                                 throw new ArgumentException ("Environment variable name cannot contain an equal character.", "variable");
 832                         if (variable[0] == '\0')
 833                                 throw new ArgumentException ("The first char in the string is the null character.", "variable");
 834
 835                         switch (target) {
 836                         case EnvironmentVariableTarget.Process:
 837                                 InternalSetEnvironmentVariable (variable, value);
 838                                 break;
 839                         case EnvironmentVariableTarget.Machine:
 840                                 if (!IsRunningOnWindows)
 841                                         return;
 842                                 using (Microsoft.Win32.RegistryKey env = Microsoft.Win32.Registry.LocalMachine.OpenSubKey (@"SYSTEM\CurrentControlSet\Control\Session Manager\Environment", true)) {
 843                                         if (String.IsNullOrEmpty (value))
 844                                                 env.DeleteValue (variable, false);
 845                                         else
 846                                                 env.SetValue (variable, value);
 847                                         internalBroadcastSettingChange ();
 848                                 }
 849                                 break;
 850                         case EnvironmentVariableTarget.User:
 851                                 if (!IsRunningOnWindows)
 852                                         return;
 853                                 using (Microsoft.Win32.RegistryKey env = Microsoft.Win32.Registry.CurrentUser.OpenSubKey ("Environment", true)) {
 854                                         if (String.IsNullOrEmpty (value))
 855                                                 env.DeleteValue (variable, false);
 856                                         else
 857                                                 env.SetValue (variable, value);
 858                                         internalBroadcastSettingChange ();
 859                                 }
 860                                 break;
 861                         default:
 862                                 throw new ArgumentException ("target");
 863                         }
 864                 }
 865 #else
 866                 public static void SetEnvironmentVariable (string variable, string value)
 867                 {
 868                         if (variable == null)
 869                                 throw new ArgumentNullException ("variable");
 870                         if (variable == String.Empty)
 871                                 throw new ArgumentException ("String cannot be of zero length.", "variable");
 872                         if (variable.IndexOf ('=') != -1)
 873                                 throw new ArgumentException ("Environment variable name cannot contain an equal character.", "variable");
 874                         if (variable[0] == '\0')
 875                                 throw new ArgumentException ("The first char in the string is the null character.", "variable");
 876
 877                         InternalSetEnvironmentVariable (variable, value);
 878                 }
 879 #endif
 880                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 881                 internal static extern void InternalSetEnvironmentVariable (string variable, string value);
 882
 883                 [SecurityPermission (SecurityAction.LinkDemand, UnmanagedCode=true)]
 884                 public static void FailFast (string message)
 885                 {
 886                         throw new NotImplementedException ();
 887                 }
 888
 889                 internal static void FailFast (String message, uint exitCode)
 890                 {
 891                         throw new NotImplementedException ();
 892                 }
 893
 894                 [SecurityCritical]
 895                 public static void FailFast (string message, Exception exception)
 896                 {
 897                         throw new NotImplementedException ();
 898                 }
 899
 900                 public static bool Is64BitOperatingSystem {
 901                         get { return IntPtr.Size == 8; } // FIXME: is this good enough?
 902                 }
 903
 904                 public static int SystemPageSize {
 905                         get { return GetPageSize (); }
 906                 }
 907
 908                 public
 909                 static bool Is64BitProcess {
 910                         get { return IntPtr.Size == 8; }
 911                 }
 912
 913                 public static extern int ProcessorCount {
 914                         [EnvironmentPermission (SecurityAction.Demand, Read="NUMBER_OF_PROCESSORS")]
 915                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 916                         get;
 917                 }
 918
 919                 // private methods
 920 #if (MONOTOUCH || MONODROID || XAMMAC)
 921                 internal const bool IsRunningOnWindows = false;
 922 #else
 923                 internal static bool IsRunningOnWindows {
 924                         get { return ((int) Platform < 4); }
 925                 }
 926 #endif
 927
 928 #if !NET_2_1
 929                 //
 930                 // Used by gacutil.exe
 931                 //
 932 #pragma warning disable 169
 933                 private static string GacPath {
 934                         get {
 935                                 if (Environment.IsRunningOnWindows) {
 936                                         /* On windows, we don't know the path where mscorlib.dll will be installed */
 937                                         string corlibDir = new DirectoryInfo (Path.GetDirectoryName (typeof (int).Assembly.Location)).Parent.Parent.FullName;
 938                                         return Path.Combine (Path.Combine (corlibDir, "mono"), "gac");
 939                                 }
 940
 941                                 return Path.Combine (Path.Combine (internalGetGacPath (), "mono"), "gac");
 942                         }
 943                 }
 944 #pragma warning restore 169
 945                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 946                 internal extern static string internalGetGacPath ();
 947 #endif
 948                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 949                 private extern static string [] GetLogicalDrivesInternal ();
 950
 951                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 952                 private extern static string [] GetEnvironmentVariableNames ();
 953
 954                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 955                 internal extern static string GetMachineConfigPath ();
 956
 957                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 958                 internal extern static string internalGetHome ();
 959
 960                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 961                 internal extern static int GetPageSize ();
 962
 963                 static internal bool IsUnix {
 964                         get {
 965                                 int platform = (int) Environment.Platform;
 966
 967                                 return (platform == 4 || platform == 128 || platform == 6);
 968                         }
 969                 }
 970                 static internal bool IsMacOS {
 971                         get {
 972                                 return Environment.Platform == PlatformID.MacOSX;
 973                         }
 974                 }
 975
 976                 internal static bool IsCLRHosted {
 977                         get {
 978                                 return false;
 979                         }
 980                 }
 981
 982                 internal static void TriggerCodeContractFailure(ContractFailureKind failureKind, String message, String condition, String exceptionAsString)
 983                 {
 984
 985                 }
 986         }
 987 }
 988