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
  43 namespace System {
  44
  45         [ComVisible (true)]
  46         public static class Environment {
  47
  48                 /*
  49                  * This is the version number of the corlib-runtime interface. When
  50                  * making changes to this interface (by changing the layout
  51                  * of classes the runtime knows about, changing icall signature or
  52                  * semantics etc), increment this variable. Also increment the
  53                  * pair of this variable in the runtime in metadata/appdomain.c.
  54                  * Changes which are already detected at runtime, like the addition
  55                  * of icalls, do not require an increment.
  56                  */
  57 #pragma warning disable 169
  58                 private const int mono_corlib_version = 105 + 0x0210;
  59 #pragma warning restore 169
  60
  61                 [ComVisible (true)]
  62                 public enum SpecialFolder
  63                 {
  64                         MyDocuments = 0x05,
  65                         Desktop = 0x00,
  66                         MyComputer = 0x11,
  67                         Programs = 0x02,
  68                         Personal = 0x05,
  69                         Favorites = 0x06,
  70                         Startup = 0x07,
  71                         Recent = 0x08,
  72                         SendTo = 0x09,
  73                         StartMenu = 0x0b,
  74                         MyMusic = 0x0d,
  75                         DesktopDirectory = 0x10,
  76                         Templates = 0x15,
  77                         ApplicationData = 0x1a,
  78                         LocalApplicationData = 0x1c,
  79                         InternetCache = 0x20,
  80                         Cookies = 0x21,
  81                         History = 0x22,
  82                         CommonApplicationData   = 0x23,
  83                         System = 0x25,
  84                         ProgramFiles = 0x26,
  85                         MyPictures = 0x27,
  86                         CommonProgramFiles = 0x2b,
  87 #if NET_4_0 || MOONLIGHT || MOBILE
  88                         MyVideos = 0x0e,
  89 #endif
  90 #if NET_4_0
  91                         NetworkShortcuts = 0x13,
  92                         Fonts = 0x14,
  93                         CommonStartMenu = 0x16,
  94                         CommonPrograms = 0x17,
  95                         CommonStartup = 0x18,
  96                         CommonDesktopDirectory = 0x19,
  97                         PrinterShortcuts = 0x1b,
  98                         Windows = 0x24,
  99                         UserProfile = 0x28,
 100                         SystemX86 = 0x29,
 101                         ProgramFilesX86 = 0x2a,
 102                         CommonProgramFilesX86 = 0x2c,
 103                         CommonTemplates = 0x2d,
 104                         CommonDocuments = 0x2e,
 105                         CommonAdminTools = 0x2f,
 106                         AdminTools = 0x30,
 107                         CommonMusic = 0x35,
 108                         CommonPictures = 0x36,
 109                         CommonVideos = 0x37,
 110                         Resources = 0x38,
 111                         LocalizedResources = 0x39,
 112                         CommonOemLinks = 0x3a,
 113                         CDBurning = 0x3b,
 114 #endif
 115                 }
 116
 117 #if NET_4_0
 118                 public
 119 #else
 120                 internal
 121 #endif
 122                 enum SpecialFolderOption {
 123                         None = 0,
 124                         DoNotVerify = 0x4000,
 125                         Create = 0x8000
 126                 }
 127
 128                 /// <summary>
 129                 /// Gets the command line for this process
 130                 /// </summary>
 131                 public static string CommandLine {
 132                         // note: security demand inherited from calling GetCommandLineArgs
 133                         get {
 134                                 StringBuilder sb = new StringBuilder ();
 135                                 foreach (string str in GetCommandLineArgs ()) {
 136                                         bool escape = false;
 137                                         string quote = "";
 138                                         string s = str;
 139                                         for (int i = 0; i < s.Length; i++) {
 140                                                 if (quote.Length == 0 && Char.IsWhiteSpace (s [i])) {
 141                                                         quote = "\"";
 142                                                 } else if (s [i] == '"') {
 143                                                         escape = true;
 144                                                 }
 145                                         }
 146                                         if (escape && quote.Length != 0) {
 147                                                 s = s.Replace ("\"", "\\\"");
 148                                         }
 149                                         sb.AppendFormat ("{0}{1}{0} ", quote, s);
 150                                 }
 151                                 if (sb.Length > 0)
 152                                         sb.Length--;
 153                                 return sb.ToString ();
 154                         }
 155                 }
 156
 157                 /// <summary>
 158                 /// Gets or sets the current directory. Actually this is supposed to get
 159                 /// and/or set the process start directory acording to the documentation
 160                 /// but actually test revealed at beta2 it is just Getting/Setting the CurrentDirectory
 161                 /// </summary>
 162                 public static string CurrentDirectory
 163                 {
 164                         get {
 165                                 return Directory.GetCurrentDirectory ();
 166                         }
 167                         set {
 168                                 Directory.SetCurrentDirectory (value);
 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 = Version.CreateFromString (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                 /// <summary>
 247                 /// Get StackTrace
 248                 /// </summary>
 249                 public static string StackTrace {
 250                         [EnvironmentPermission (SecurityAction.Demand, Unrestricted=true)]
 251                         get {
 252                                 System.Diagnostics.StackTrace trace = new System.Diagnostics.StackTrace (0, true);
 253                                 return trace.ToString ();
 254                         }
 255                 }
 256 #if !NET_2_1
 257                 /// <summary>
 258                 /// Get a fully qualified path to the system directory
 259                 /// </summary>
 260                 public static string SystemDirectory {
 261                         get {
 262                                 return GetFolderPath (SpecialFolder.System);
 263                         }
 264                 }
 265 #endif
 266                 /// <summary>
 267                 /// Get the number of milliseconds that have elapsed since the system was booted
 268                 /// </summary>
 269                 public extern static int TickCount {
 270                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 271                         get;
 272                 }
 273
 274                 /// <summary>
 275                 /// Get UserDomainName
 276                 /// </summary>
 277                 public static string UserDomainName {
 278                         // FIXME: this variable doesn't exist (at least not on WinXP) - reported to MS as FDBK20562
 279                         [EnvironmentPermission (SecurityAction.Demand, Read="USERDOMAINNAME")]
 280                         get {
 281                                 return MachineName;
 282                         }
 283                 }
 284
 285                 /// <summary>
 286                 /// Gets a flag indicating whether the process is in interactive mode
 287                 /// </summary>
 288                 [MonoTODO ("Currently always returns false, regardless of interactive state")]
 289                 public static bool UserInteractive {
 290                         get {
 291                                 return false;
 292                         }
 293                 }
 294
 295                 /// <summary>
 296                 /// Get the user name of current process is running under
 297                 /// </summary>
 298                 public extern static string UserName {
 299                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 300                         [EnvironmentPermission (SecurityAction.Demand, Read="USERNAME;USER")]
 301                         get;
 302                 }
 303
 304                 /// <summary>
 305                 /// Get the version of the common language runtime
 306                 /// </summary>
 307                 public static Version Version {
 308                         get {
 309                                 return new Version (Consts.FxFileVersion);
 310                         }
 311                 }
 312
 313                 /// <summary>
 314                 /// Get the amount of physical memory mapped to process
 315                 /// </summary>
 316                 [MonoTODO ("Currently always returns zero")]
 317                 public static long WorkingSet {
 318                         [EnvironmentPermission (SecurityAction.Demand, Unrestricted=true)]
 319                         get { return 0; }
 320                 }
 321
 322                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 323                 [SecurityPermission (SecurityAction.Demand, UnmanagedCode=true)]
 324                 public extern static void Exit (int exitCode);
 325
 326                 /// <summary>
 327                 /// Substitute environment variables in the argument "name"
 328                 /// </summary>
 329                 public static string ExpandEnvironmentVariables (string name)
 330                 {
 331                         if (name == null)
 332                                 throw new ArgumentNullException ("name");
 333
 334                         int off1 = name.IndexOf ('%');
 335                         if (off1 == -1)
 336                                 return name;
 337
 338                         int len = name.Length;
 339                         int off2 = 0;
 340                         if (off1 == len - 1 || (off2 = name.IndexOf ('%', off1 + 1)) == -1)
 341                                 return name;
 342
 343                         StringBuilder result = new StringBuilder ();
 344                         result.Append (name, 0, off1);
 345                         Hashtable tbl = null;
 346                         do {
 347                                 string var = name.Substring (off1 + 1, off2 - off1 - 1);
 348                                 string value = GetEnvironmentVariable (var);
 349                                 if (value == null && Environment.IsRunningOnWindows) {
 350                                         // On windows, env. vars. are case insensitive
 351                                         if (tbl == null)
 352                                                 tbl = GetEnvironmentVariablesNoCase ();
 353
 354                                         value = tbl [var] as string;
 355                                 }
 356
 357                                 // If value not found, add %FOO to stream,
 358                                 //  and use the closing % for the next iteration.
 359                                 // If value found, expand it in place of %FOO%
 360                                 if (value == null) {
 361                                         result.Append ('%');
 362                                         result.Append (var);
 363                                         off2--;
 364                                 } else {
 365                                         result.Append (value);
 366                                 }
 367                                 int oldOff2 = off2;
 368                                 off1 = name.IndexOf ('%', off2 + 1);
 369                                 // If no % found for off1, don't look for one for off2
 370                                 off2 = (off1 == -1 || off2 > len-1)? -1 :name.IndexOf ('%', off1 + 1);
 371                                 // textLen is the length of text between the closing % of current iteration
 372                                 //  and the starting % of the next iteration if any. This text is added to output
 373                                 int textLen;
 374                                 // If no new % found, use all the remaining text
 375                                 if (off1 == -1 || off2 == -1)
 376                                         textLen = len - oldOff2 - 1;
 377                                 // If value found in current iteration, use text after current closing % and next %
 378                                 else if(value != null)
 379                                         textLen = off1 - oldOff2 - 1;
 380                                 // If value not found in current iteration, but a % was found for next iteration,
 381                                 //  use text from current closing % to the next %.
 382                                 else
 383                                         textLen = off1 - oldOff2;
 384                                 if(off1 >= oldOff2 || off1 == -1)
 385                                         result.Append (name, oldOff2+1, textLen);
 386                         } while (off2 > -1 && off2 < len);
 387
 388                         return result.ToString ();
 389
 390                 }
 391
 392                 /// <summary>
 393                 /// Return an array of the command line arguments of the current process
 394                 /// </summary>
 395                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 396                 [EnvironmentPermissionAttribute (SecurityAction.Demand, Read = "PATH")]
 397                 public extern static string[] GetCommandLineArgs ();
 398
 399                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 400                 internal extern static string internalGetEnvironmentVariable (string variable);
 401
 402                 /// <summary>
 403                 /// Return a string containing the value of the environment
 404                 /// variable identifed by parameter "variable"
 405                 /// </summary>
 406                 public static string GetEnvironmentVariable (string variable)
 407                 {
 408 #if !NET_2_1
 409                         if (SecurityManager.SecurityEnabled) {
 410                                 new EnvironmentPermission (EnvironmentPermissionAccess.Read, variable).Demand ();
 411                         }
 412 #endif
 413                         return internalGetEnvironmentVariable (variable);
 414                 }
 415
 416                 static Hashtable GetEnvironmentVariablesNoCase ()
 417                 {
 418                         Hashtable vars = new Hashtable (CaseInsensitiveHashCodeProvider.Default,
 419                                                         CaseInsensitiveComparer.Default);
 420
 421                         foreach (string name in GetEnvironmentVariableNames ()) {
 422                                 vars [name] = internalGetEnvironmentVariable (name);
 423                         }
 424
 425                         return vars;
 426                 }
 427
 428                 /// <summary>
 429                 /// Return a set of all environment variables and their values
 430                 /// </summary>
 431 #if !NET_2_1
 432                 public static IDictionary GetEnvironmentVariables ()
 433                 {
 434                         StringBuilder sb = null;
 435                         if (SecurityManager.SecurityEnabled) {
 436                                 // we must have access to each variable to get the lot
 437                                 sb = new StringBuilder ();
 438                                 // but (performance-wise) we do not want a stack-walk
 439                                 // for each of them so we concatenate them
 440                         }
 441
 442                         Hashtable vars = new Hashtable ();
 443                         foreach (string name in GetEnvironmentVariableNames ()) {
 444                                 vars [name] = internalGetEnvironmentVariable (name);
 445                                 if (sb != null) {
 446                                         sb.Append (name);
 447                                         sb.Append (";");
 448                                 }
 449                         }
 450
 451                         if (sb != null) {
 452                                 new EnvironmentPermission (EnvironmentPermissionAccess.Read, sb.ToString ()).Demand ();
 453                         }
 454                         return vars;
 455                 }
 456 #else
 457                 [EnvironmentPermission (SecurityAction.Demand, Unrestricted=true)]
 458                 public static IDictionary GetEnvironmentVariables ()
 459                 {
 460                         Hashtable vars = new Hashtable ();
 461                         foreach (string name in GetEnvironmentVariableNames ()) {
 462                                 vars [name] = internalGetEnvironmentVariable (name);
 463                         }
 464                         return vars;
 465                 }
 466 #endif
 467
 468                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 469                 private extern static string GetWindowsFolderPath (int folder);
 470
 471                 /// <summary>
 472                 /// Returns the fully qualified path of the
 473                 /// folder specified by the "folder" parameter
 474                 /// </summary>
 475                 public static string GetFolderPath (SpecialFolder folder)
 476                 {
 477                         return GetFolderPath (folder, SpecialFolderOption.None);
 478                 }
 479 #if NET_4_0
 480                 public
 481 #endif
 482                 static string GetFolderPath(SpecialFolder folder, SpecialFolderOption option)
 483                 {
 484                         SecurityManager.EnsureElevatedPermissions (); // this is a no-op outside moonlight
 485
 486                         string dir = null;
 487
 488                         if (Environment.IsRunningOnWindows)
 489                                 dir = GetWindowsFolderPath ((int) folder);
 490                         else
 491                                 dir = UnixGetFolderPath (folder, option);
 492
 493 #if !NET_2_1
 494                         if ((dir != null) && (dir.Length > 0) && SecurityManager.SecurityEnabled) {
 495                                 new FileIOPermission (FileIOPermissionAccess.PathDiscovery, dir).Demand ();
 496                         }
 497 #endif
 498                         return dir;
 499                 }
 500
 501                 private static string ReadXdgUserDir (string config_dir, string home_dir, string key, string fallback)
 502                 {
 503                         string env_path = internalGetEnvironmentVariable (key);
 504                         if (env_path != null && env_path != String.Empty) {
 505                                 return env_path;
 506                         }
 507
 508                         string user_dirs_path = Path.Combine (config_dir, "user-dirs.dirs");
 509
 510                         if (!File.Exists (user_dirs_path)) {
 511                                 return Path.Combine (home_dir, fallback);
 512                         }
 513
 514                         try {
 515                                 using(StreamReader reader = new StreamReader (user_dirs_path)) {
 516                                         string line;
 517                                         while ((line = reader.ReadLine ()) != null) {
 518                                                 line = line.Trim ();
 519                                                 int delim_index = line.IndexOf ('=');
 520                                                 if(delim_index > 8 && line.Substring (0, delim_index) == key) {
 521                                                         string path = line.Substring (delim_index + 1).Trim ('"');
 522                                                         bool relative = false;
 523
 524                                                         if (path.StartsWith ("$HOME/")) {
 525                                                                 relative = true;
 526                                                                 path = path.Substring (6);
 527                                                         } else if (!path.StartsWith ("/")) {
 528                                                                 relative = true;
 529                                                         }
 530
 531                                                         return relative ? Path.Combine (home_dir, path) : path;
 532                                                 }
 533                                         }
 534                                 }
 535                         } catch (FileNotFoundException) {
 536                         }
 537
 538                         return Path.Combine (home_dir, fallback);
 539                 }
 540
 541
 542                 // the security runtime (and maybe other parts of corlib) needs the
 543                 // information to initialize themselves before permissions can be checked
 544                 internal static string UnixGetFolderPath (SpecialFolder folder, SpecialFolderOption option)
 545                 {
 546                         string home = internalGetHome ();
 547
 548                         // http://freedesktop.org/Standards/basedir-spec/basedir-spec-0.6.html
 549
 550                         // note: skip security check for environment variables
 551                         string data = internalGetEnvironmentVariable ("XDG_DATA_HOME");
 552                         if ((data == null) || (data == String.Empty)) {
 553                                 data = Path.Combine (home, ".local");
 554                                 data = Path.Combine (data, "share");
 555                         }
 556
 557                         // note: skip security check for environment variables
 558                         string config = internalGetEnvironmentVariable ("XDG_CONFIG_HOME");
 559                         if ((config == null) || (config == String.Empty)) {
 560                                 config = Path.Combine (home, ".config");
 561                         }
 562
 563                         switch (folder) {
 564                         // MyComputer is a virtual directory
 565                         case SpecialFolder.MyComputer:
 566                                 return String.Empty;
 567
 568                         // personal == ~
 569                         case SpecialFolder.Personal:
 570 #if MONOTOUCH
 571                                 return Path.Combine (home, "Documents");
 572 #else
 573                                 return home;
 574 #endif
 575                         // use FDO's CONFIG_HOME. This data will be synced across a network like the windows counterpart.
 576                         case SpecialFolder.ApplicationData:
 577 #if MONOTOUCH
 578                         {
 579                                 string dir = Path.Combine (Path.Combine (home, "Documents"), ".config");
 580                                 if (option == SpecialFolderOption.Create){
 581                                         if (!Directory.Exists (dir))
 582                                                 Directory.CreateDirectory (dir);
 583                                 }
 584                                 return dir;
 585                         }
 586 #else
 587                                 return config;
 588 #endif
 589                         //use FDO's DATA_HOME. This is *NOT* synced
 590                         case SpecialFolder.LocalApplicationData:
 591 #if MONOTOUCH
 592                         {
 593                                 string dir = Path.Combine (home, "Documents");
 594                                 if (!Directory.Exists (dir))
 595                                         Directory.CreateDirectory (dir);
 596
 597                                 return dir;
 598                         }
 599 #else
 600                                 return data;
 601 #endif
 602
 603                         case SpecialFolder.Desktop:
 604                         case SpecialFolder.DesktopDirectory:
 605                                 return ReadXdgUserDir (config, home, "XDG_DESKTOP_DIR", "Desktop");
 606
 607                         case SpecialFolder.MyMusic:
 608                                 if (Platform == PlatformID.MacOSX)
 609                                         return Path.Combine (home, "Music");
 610                                 else
 611                                         return ReadXdgUserDir (config, home, "XDG_MUSIC_DIR", "Music");
 612
 613                         case SpecialFolder.MyPictures:
 614                                 if (Platform == PlatformID.MacOSX)
 615                                         return Path.Combine (home, "Pictures");
 616                                 else
 617                                         return ReadXdgUserDir (config, home, "XDG_PICTURES_DIR", "Pictures");
 618
 619                         case SpecialFolder.Templates:
 620                                 return ReadXdgUserDir (config, home, "XDG_TEMPLATES_DIR", "Templates");
 621 #if NET_4_0 || MOONLIGHT || MOBILE
 622                         case SpecialFolder.MyVideos:
 623                                 return ReadXdgUserDir (config, home, "XDG_VIDEOS_DIR", "Videos");
 624 #endif
 625 #if NET_4_0
 626                         case SpecialFolder.CommonTemplates:
 627                                 return "/usr/share/templates";
 628                         case SpecialFolder.Fonts:
 629                                 if (Platform == PlatformID.MacOSX)
 630                                         return Path.Combine (home, "Library", "Fonts");
 631
 632                                 return Path.Combine (home, ".fonts");
 633 #endif
 634                         // these simply dont exist on Linux
 635                         // The spec says if a folder doesnt exist, we
 636                         // should return ""
 637                         case SpecialFolder.Favorites:
 638                                 if (Platform == PlatformID.MacOSX)
 639                                         return Path.Combine (home, "Library", "Favorites");
 640                                 else
 641                                         return String.Empty;
 642
 643                         case SpecialFolder.ProgramFiles:
 644                                 if (Platform == PlatformID.MacOSX)
 645                                         return "/Applications";
 646                                 else
 647                                         return String.Empty;
 648
 649                         case SpecialFolder.InternetCache:
 650                                 if (Platform == PlatformID.MacOSX)
 651                                         return Path.Combine (home, "Library", "Caches");
 652                                 else
 653                                         return String.Empty;
 654
 655 #if NET_4_0
 656                                 // #2873
 657                         case SpecialFolder.UserProfile:
 658                                 return home;
 659 #endif
 660
 661                         case SpecialFolder.Programs:
 662                         case SpecialFolder.SendTo:
 663                         case SpecialFolder.StartMenu:
 664                         case SpecialFolder.Startup:
 665                         case SpecialFolder.Cookies:
 666                         case SpecialFolder.History:
 667                         case SpecialFolder.Recent:
 668                         case SpecialFolder.CommonProgramFiles:
 669                         case SpecialFolder.System:
 670 #if NET_4_0
 671                         case SpecialFolder.NetworkShortcuts:
 672                         case SpecialFolder.CommonStartMenu:
 673                         case SpecialFolder.CommonPrograms:
 674                         case SpecialFolder.CommonStartup:
 675                         case SpecialFolder.CommonDesktopDirectory:
 676                         case SpecialFolder.PrinterShortcuts:
 677                         case SpecialFolder.Windows:
 678                         case SpecialFolder.SystemX86:
 679                         case SpecialFolder.ProgramFilesX86:
 680                         case SpecialFolder.CommonProgramFilesX86:
 681                         case SpecialFolder.CommonDocuments:
 682                         case SpecialFolder.CommonAdminTools:
 683                         case SpecialFolder.AdminTools:
 684                         case SpecialFolder.CommonMusic:
 685                         case SpecialFolder.CommonPictures:
 686                         case SpecialFolder.CommonVideos:
 687                         case SpecialFolder.Resources:
 688                         case SpecialFolder.LocalizedResources:
 689                         case SpecialFolder.CommonOemLinks:
 690                         case SpecialFolder.CDBurning:
 691 #endif
 692                                 return String.Empty;
 693                         // This is where data common to all users goes
 694                         case SpecialFolder.CommonApplicationData:
 695                                 return "/usr/share";
 696                         default:
 697                                 throw new ArgumentException ("Invalid SpecialFolder");
 698                         }
 699                 }
 700
 701
 702                 [EnvironmentPermission (SecurityAction.Demand, Unrestricted=true)]
 703                 public static string[] GetLogicalDrives ()
 704                 {
 705                         return GetLogicalDrivesInternal ();
 706                 }
 707
 708 #if !NET_2_1
 709                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 710                 private static extern void internalBroadcastSettingChange ();
 711
 712                 public static string GetEnvironmentVariable (string variable, EnvironmentVariableTarget target)
 713                 {
 714                         switch (target) {
 715                         case EnvironmentVariableTarget.Process:
 716                                 return GetEnvironmentVariable (variable);
 717                         case EnvironmentVariableTarget.Machine:
 718                                 new EnvironmentPermission (PermissionState.Unrestricted).Demand ();
 719                                 if (!IsRunningOnWindows)
 720                                         return null;
 721                                 using (Microsoft.Win32.RegistryKey env = Microsoft.Win32.Registry.LocalMachine.OpenSubKey (@"SYSTEM\CurrentControlSet\Control\Session Manager\Environment")) {
 722                                         object regvalue = env.GetValue (variable);
 723                                         return (regvalue == null) ? null : regvalue.ToString ();
 724                                 }
 725                         case EnvironmentVariableTarget.User:
 726                                 new EnvironmentPermission (PermissionState.Unrestricted).Demand ();
 727                                 if (!IsRunningOnWindows)
 728                                         return null;
 729                                 using (Microsoft.Win32.RegistryKey env = Microsoft.Win32.Registry.CurrentUser.OpenSubKey ("Environment", false)) {
 730                                         object regvalue = env.GetValue (variable);
 731                                         return (regvalue == null) ? null : regvalue.ToString ();
 732                                 }
 733                         default:
 734                                 throw new ArgumentException ("target");
 735                         }
 736                 }
 737
 738                 public static IDictionary GetEnvironmentVariables (EnvironmentVariableTarget target)
 739                 {
 740                         IDictionary variables = (IDictionary)new Hashtable ();
 741                         switch (target) {
 742                         case EnvironmentVariableTarget.Process:
 743                                 variables = GetEnvironmentVariables ();
 744                                 break;
 745                         case EnvironmentVariableTarget.Machine:
 746                                 new EnvironmentPermission (PermissionState.Unrestricted).Demand ();
 747                                 if (IsRunningOnWindows) {
 748                                         using (Microsoft.Win32.RegistryKey env = Microsoft.Win32.Registry.LocalMachine.OpenSubKey (@"SYSTEM\CurrentControlSet\Control\Session Manager\Environment")) {
 749                                                 string[] value_names = env.GetValueNames ();
 750                                                 foreach (string value_name in value_names)
 751                                                         variables.Add (value_name, env.GetValue (value_name));
 752                                         }
 753                                 }
 754                                 break;
 755                         case EnvironmentVariableTarget.User:
 756                                 new EnvironmentPermission (PermissionState.Unrestricted).Demand ();
 757                                 if (IsRunningOnWindows) {
 758                                         using (Microsoft.Win32.RegistryKey env = Microsoft.Win32.Registry.CurrentUser.OpenSubKey ("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                         default:
 766                                 throw new ArgumentException ("target");
 767                         }
 768                         return variables;
 769                 }
 770
 771                 [EnvironmentPermission (SecurityAction.Demand, Unrestricted=true)]
 772                 public static void SetEnvironmentVariable (string variable, string value)
 773                 {
 774                         SetEnvironmentVariable (variable, value, EnvironmentVariableTarget.Process);
 775                 }
 776
 777                 [EnvironmentPermission (SecurityAction.Demand, Unrestricted = true)]
 778                 public static void SetEnvironmentVariable (string variable, string value, EnvironmentVariableTarget target)
 779                 {
 780                         if (variable == null)
 781                                 throw new ArgumentNullException ("variable");
 782                         if (variable == String.Empty)
 783                                 throw new ArgumentException ("String cannot be of zero length.", "variable");
 784                         if (variable.IndexOf ('=') != -1)
 785                                 throw new ArgumentException ("Environment variable name cannot contain an equal character.", "variable");
 786                         if (variable[0] == '\0')
 787                                 throw new ArgumentException ("The first char in the string is the null character.", "variable");
 788
 789                         switch (target) {
 790                         case EnvironmentVariableTarget.Process:
 791                                 InternalSetEnvironmentVariable (variable, value);
 792                                 break;
 793                         case EnvironmentVariableTarget.Machine:
 794                                 if (!IsRunningOnWindows)
 795                                         return;
 796                                 using (Microsoft.Win32.RegistryKey env = Microsoft.Win32.Registry.LocalMachine.OpenSubKey (@"SYSTEM\CurrentControlSet\Control\Session Manager\Environment", true)) {
 797                                         if (String.IsNullOrEmpty (value))
 798                                                 env.DeleteValue (variable, false);
 799                                         else
 800                                                 env.SetValue (variable, value);
 801                                         internalBroadcastSettingChange ();
 802                                 }
 803                                 break;
 804                         case EnvironmentVariableTarget.User:
 805                                 if (!IsRunningOnWindows)
 806                                         return;
 807                                 using (Microsoft.Win32.RegistryKey env = Microsoft.Win32.Registry.CurrentUser.OpenSubKey ("Environment", true)) {
 808                                         if (String.IsNullOrEmpty (value))
 809                                                 env.DeleteValue (variable, false);
 810                                         else
 811                                                 env.SetValue (variable, value);
 812                                         internalBroadcastSettingChange ();
 813                                 }
 814                                 break;
 815                         default:
 816                                 throw new ArgumentException ("target");
 817                         }
 818                 }
 819
 820                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 821                 internal static extern void InternalSetEnvironmentVariable (string variable, string value);
 822 #endif
 823                 [SecurityPermission (SecurityAction.LinkDemand, UnmanagedCode=true)]
 824                 public static void FailFast (string message)
 825                 {
 826                         throw new NotImplementedException ();
 827                 }
 828
 829 #if NET_4_0 || MOONLIGHT || MOBILE
 830                 [SecurityCritical]
 831                 public static void FailFast (string message, Exception exception)
 832                 {
 833                         throw new NotImplementedException ();
 834                 }
 835 #endif
 836
 837 #if NET_4_0
 838                 public static bool Is64BitOperatingSystem {
 839                         get { return IntPtr.Size == 8; } // FIXME: is this good enough?
 840                 }
 841
 842                 public static bool Is64BitProcess {
 843                         get { return Is64BitOperatingSystem; }
 844                 }
 845
 846                 public static int SystemPageSize {
 847                         get { return GetPageSize (); }
 848                 }
 849 #endif
 850
 851                 public static extern int ProcessorCount {
 852                         [EnvironmentPermission (SecurityAction.Demand, Read="NUMBER_OF_PROCESSORS")]
 853                         [MethodImplAttribute (MethodImplOptions.InternalCall)]
 854                         get;
 855                 }
 856
 857                 // private methods
 858
 859                 internal static bool IsRunningOnWindows {
 860                         get { return ((int) Platform < 4); }
 861                 }
 862 #if !NET_2_1
 863                 //
 864                 // Used by gacutil.exe
 865                 //
 866 #pragma warning disable 169
 867                 private static string GacPath {
 868                         get {
 869                                 if (Environment.IsRunningOnWindows) {
 870                                         /* On windows, we don't know the path where mscorlib.dll will be installed */
 871                                         string corlibDir = new DirectoryInfo (Path.GetDirectoryName (typeof (int).Assembly.Location)).Parent.Parent.FullName;
 872                                         return Path.Combine (Path.Combine (corlibDir, "mono"), "gac");
 873                                 }
 874
 875                                 return Path.Combine (Path.Combine (internalGetGacPath (), "mono"), "gac");
 876                         }
 877                 }
 878 #pragma warning restore 169
 879                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 880                 internal extern static string internalGetGacPath ();
 881 #endif
 882                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 883                 private extern static string [] GetLogicalDrivesInternal ();
 884
 885                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 886                 private extern static string [] GetEnvironmentVariableNames ();
 887
 888                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 889                 internal extern static string GetMachineConfigPath ();
 890
 891                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 892                 internal extern static string internalGetHome ();
 893
 894                 [MethodImplAttribute (MethodImplOptions.InternalCall)]
 895                 internal extern static int GetPageSize ();
 896
 897                 static internal bool IsUnix {
 898                         get {
 899                                 int platform = (int) Environment.Platform;
 900
 901                                 return (platform == 4 || platform == 128 || platform == 6);
 902                         }
 903                 }
 904                 static internal bool IsMacOS {
 905                         get {
 906                                 return Environment.Platform == PlatformID.MacOSX;
 907                         }
 908                 }
 909         }
 910 }
 911