irc/TechBot/CHMLibrary/HttpUtility.cs

   1 //
   2 // System.Web.HttpUtility
   3 //
   4 // Authors:
   5 //   Patrik Torstensson (Patrik.Torstensson@labs2.com)
   6 //   Wictor Wilén (decode/encode functions) (wictor@ibizkit.se)
   7 //   Tim Coleman (tim@timcoleman.com)
   8 //   Gonzalo Paniagua Javier (gonzalo@ximian.com)
   9 //
  10
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31 using System;
  32 using System.Collections;
  33 using System.Globalization;
  34 using System.IO;
  35 using System.Text;
  36 // using System.Web.Util;
  37
  38 namespace HtmlHelp.ChmDecoding
  39 {
  40         public sealed class HttpUtility {
  41
  42                 #region Fields
  43
  44                 const string _hex = "0123456789ABCDEF";
  45                 const string _chars = "<>;:.?=&@*+%/\\";
  46                 static Hashtable entities;
  47                 static object lock_ = new object ();
  48
  49                 #endregion // Fields
  50
  51                 static Hashtable Entities {
  52                         get {
  53                                 lock (lock_) {
  54                                         if (entities == null)
  55                                                 InitEntities ();
  56
  57                                         return entities;
  58                                 }
  59                         }
  60                 }
  61
  62                 #region Constructors
  63
  64                 static void InitEntities ()
  65                 {
  66                         // Build the hash table of HTML entity references.  This list comes
  67                         // from the HTML 4.01 W3C recommendation.
  68                         entities = new Hashtable ();
  69                         entities.Add ("nbsp", '\u00A0');
  70                         entities.Add ("iexcl", '\u00A1');
  71                         entities.Add ("cent", '\u00A2');
  72                         entities.Add ("pound", '\u00A3');
  73                         entities.Add ("curren", '\u00A4');
  74                         entities.Add ("yen", '\u00A5');
  75                         entities.Add ("brvbar", '\u00A6');
  76                         entities.Add ("sect", '\u00A7');
  77                         entities.Add ("uml", '\u00A8');
  78                         entities.Add ("copy", '\u00A9');
  79                         entities.Add ("ordf", '\u00AA');
  80                         entities.Add ("laquo", '\u00AB');
  81                         entities.Add ("not", '\u00AC');
  82                         entities.Add ("shy", '\u00AD');
  83                         entities.Add ("reg", '\u00AE');
  84                         entities.Add ("macr", '\u00AF');
  85                         entities.Add ("deg", '\u00B0');
  86                         entities.Add ("plusmn", '\u00B1');
  87                         entities.Add ("sup2", '\u00B2');
  88                         entities.Add ("sup3", '\u00B3');
  89                         entities.Add ("acute", '\u00B4');
  90                         entities.Add ("micro", '\u00B5');
  91                         entities.Add ("para", '\u00B6');
  92                         entities.Add ("middot", '\u00B7');
  93                         entities.Add ("cedil", '\u00B8');
  94                         entities.Add ("sup1", '\u00B9');
  95                         entities.Add ("ordm", '\u00BA');
  96                         entities.Add ("raquo", '\u00BB');
  97                         entities.Add ("frac14", '\u00BC');
  98                         entities.Add ("frac12", '\u00BD');
  99                         entities.Add ("frac34", '\u00BE');
 100                         entities.Add ("iquest", '\u00BF');
 101                         entities.Add ("Agrave", '\u00C0');
 102                         entities.Add ("Aacute", '\u00C1');
 103                         entities.Add ("Acirc", '\u00C2');
 104                         entities.Add ("Atilde", '\u00C3');
 105                         entities.Add ("Auml", '\u00C4');
 106                         entities.Add ("Aring", '\u00C5');
 107                         entities.Add ("AElig", '\u00C6');
 108                         entities.Add ("Ccedil", '\u00C7');
 109                         entities.Add ("Egrave", '\u00C8');
 110                         entities.Add ("Eacute", '\u00C9');
 111                         entities.Add ("Ecirc", '\u00CA');
 112                         entities.Add ("Euml", '\u00CB');
 113                         entities.Add ("Igrave", '\u00CC');
 114                         entities.Add ("Iacute", '\u00CD');
 115                         entities.Add ("Icirc", '\u00CE');
 116                         entities.Add ("Iuml", '\u00CF');
 117                         entities.Add ("ETH", '\u00D0');
 118                         entities.Add ("Ntilde", '\u00D1');
 119                         entities.Add ("Ograve", '\u00D2');
 120                         entities.Add ("Oacute", '\u00D3');
 121                         entities.Add ("Ocirc", '\u00D4');
 122                         entities.Add ("Otilde", '\u00D5');
 123                         entities.Add ("Ouml", '\u00D6');
 124                         entities.Add ("times", '\u00D7');
 125                         entities.Add ("Oslash", '\u00D8');
 126                         entities.Add ("Ugrave", '\u00D9');
 127                         entities.Add ("Uacute", '\u00DA');
 128                         entities.Add ("Ucirc", '\u00DB');
 129                         entities.Add ("Uuml", '\u00DC');
 130                         entities.Add ("Yacute", '\u00DD');
 131                         entities.Add ("THORN", '\u00DE');
 132                         entities.Add ("szlig", '\u00DF');
 133                         entities.Add ("agrave", '\u00E0');
 134                         entities.Add ("aacute", '\u00E1');
 135                         entities.Add ("acirc", '\u00E2');
 136                         entities.Add ("atilde", '\u00E3');
 137                         entities.Add ("auml", '\u00E4');
 138                         entities.Add ("aring", '\u00E5');
 139                         entities.Add ("aelig", '\u00E6');
 140                         entities.Add ("ccedil", '\u00E7');
 141                         entities.Add ("egrave", '\u00E8');
 142                         entities.Add ("eacute", '\u00E9');
 143                         entities.Add ("ecirc", '\u00EA');
 144                         entities.Add ("euml", '\u00EB');
 145                         entities.Add ("igrave", '\u00EC');
 146                         entities.Add ("iacute", '\u00ED');
 147                         entities.Add ("icirc", '\u00EE');
 148                         entities.Add ("iuml", '\u00EF');
 149                         entities.Add ("eth", '\u00F0');
 150                         entities.Add ("ntilde", '\u00F1');
 151                         entities.Add ("ograve", '\u00F2');
 152                         entities.Add ("oacute", '\u00F3');
 153                         entities.Add ("ocirc", '\u00F4');
 154                         entities.Add ("otilde", '\u00F5');
 155                         entities.Add ("ouml", '\u00F6');
 156                         entities.Add ("divide", '\u00F7');
 157                         entities.Add ("oslash", '\u00F8');
 158                         entities.Add ("ugrave", '\u00F9');
 159                         entities.Add ("uacute", '\u00FA');
 160                         entities.Add ("ucirc", '\u00FB');
 161                         entities.Add ("uuml", '\u00FC');
 162                         entities.Add ("yacute", '\u00FD');
 163                         entities.Add ("thorn", '\u00FE');
 164                         entities.Add ("yuml", '\u00FF');
 165                         entities.Add ("fnof", '\u0192');
 166                         entities.Add ("Alpha", '\u0391');
 167                         entities.Add ("Beta", '\u0392');
 168                         entities.Add ("Gamma", '\u0393');
 169                         entities.Add ("Delta", '\u0394');
 170                         entities.Add ("Epsilon", '\u0395');
 171                         entities.Add ("Zeta", '\u0396');
 172                         entities.Add ("Eta", '\u0397');
 173                         entities.Add ("Theta", '\u0398');
 174                         entities.Add ("Iota", '\u0399');
 175                         entities.Add ("Kappa", '\u039A');
 176                         entities.Add ("Lambda", '\u039B');
 177                         entities.Add ("Mu", '\u039C');
 178                         entities.Add ("Nu", '\u039D');
 179                         entities.Add ("Xi", '\u039E');
 180                         entities.Add ("Omicron", '\u039F');
 181                         entities.Add ("Pi", '\u03A0');
 182                         entities.Add ("Rho", '\u03A1');
 183                         entities.Add ("Sigma", '\u03A3');
 184                         entities.Add ("Tau", '\u03A4');
 185                         entities.Add ("Upsilon", '\u03A5');
 186                         entities.Add ("Phi", '\u03A6');
 187                         entities.Add ("Chi", '\u03A7');
 188                         entities.Add ("Psi", '\u03A8');
 189                         entities.Add ("Omega", '\u03A9');
 190                         entities.Add ("alpha", '\u03B1');
 191                         entities.Add ("beta", '\u03B2');
 192                         entities.Add ("gamma", '\u03B3');
 193                         entities.Add ("delta", '\u03B4');
 194                         entities.Add ("epsilon", '\u03B5');
 195                         entities.Add ("zeta", '\u03B6');
 196                         entities.Add ("eta", '\u03B7');
 197                         entities.Add ("theta", '\u03B8');
 198                         entities.Add ("iota", '\u03B9');
 199                         entities.Add ("kappa", '\u03BA');
 200                         entities.Add ("lambda", '\u03BB');
 201                         entities.Add ("mu", '\u03BC');
 202                         entities.Add ("nu", '\u03BD');
 203                         entities.Add ("xi", '\u03BE');
 204                         entities.Add ("omicron", '\u03BF');
 205                         entities.Add ("pi", '\u03C0');
 206                         entities.Add ("rho", '\u03C1');
 207                         entities.Add ("sigmaf", '\u03C2');
 208                         entities.Add ("sigma", '\u03C3');
 209                         entities.Add ("tau", '\u03C4');
 210                         entities.Add ("upsilon", '\u03C5');
 211                         entities.Add ("phi", '\u03C6');
 212                         entities.Add ("chi", '\u03C7');
 213                         entities.Add ("psi", '\u03C8');
 214                         entities.Add ("omega", '\u03C9');
 215                         entities.Add ("thetasym", '\u03D1');
 216                         entities.Add ("upsih", '\u03D2');
 217                         entities.Add ("piv", '\u03D6');
 218                         entities.Add ("bull", '\u2022');
 219                         entities.Add ("hellip", '\u2026');
 220                         entities.Add ("prime", '\u2032');
 221                         entities.Add ("Prime", '\u2033');
 222                         entities.Add ("oline", '\u203E');
 223                         entities.Add ("frasl", '\u2044');
 224                         entities.Add ("weierp", '\u2118');
 225                         entities.Add ("image", '\u2111');
 226                         entities.Add ("real", '\u211C');
 227                         entities.Add ("trade", '\u2122');
 228                         entities.Add ("alefsym", '\u2135');
 229                         entities.Add ("larr", '\u2190');
 230                         entities.Add ("uarr", '\u2191');
 231                         entities.Add ("rarr", '\u2192');
 232                         entities.Add ("darr", '\u2193');
 233                         entities.Add ("harr", '\u2194');
 234                         entities.Add ("crarr", '\u21B5');
 235                         entities.Add ("lArr", '\u21D0');
 236                         entities.Add ("uArr", '\u21D1');
 237                         entities.Add ("rArr", '\u21D2');
 238                         entities.Add ("dArr", '\u21D3');
 239                         entities.Add ("hArr", '\u21D4');
 240                         entities.Add ("forall", '\u2200');
 241                         entities.Add ("part", '\u2202');
 242                         entities.Add ("exist", '\u2203');
 243                         entities.Add ("empty", '\u2205');
 244                         entities.Add ("nabla", '\u2207');
 245                         entities.Add ("isin", '\u2208');
 246                         entities.Add ("notin", '\u2209');
 247                         entities.Add ("ni", '\u220B');
 248                         entities.Add ("prod", '\u220F');
 249                         entities.Add ("sum", '\u2211');
 250                         entities.Add ("minus", '\u2212');
 251                         entities.Add ("lowast", '\u2217');
 252                         entities.Add ("radic", '\u221A');
 253                         entities.Add ("prop", '\u221D');
 254                         entities.Add ("infin", '\u221E');
 255                         entities.Add ("ang", '\u2220');
 256                         entities.Add ("and", '\u2227');
 257                         entities.Add ("or", '\u2228');
 258                         entities.Add ("cap", '\u2229');
 259                         entities.Add ("cup", '\u222A');
 260                         entities.Add ("int", '\u222B');
 261                         entities.Add ("there4", '\u2234');
 262                         entities.Add ("sim", '\u223C');
 263                         entities.Add ("cong", '\u2245');
 264                         entities.Add ("asymp", '\u2248');
 265                         entities.Add ("ne", '\u2260');
 266                         entities.Add ("equiv", '\u2261');
 267                         entities.Add ("le", '\u2264');
 268                         entities.Add ("ge", '\u2265');
 269                         entities.Add ("sub", '\u2282');
 270                         entities.Add ("sup", '\u2283');
 271                         entities.Add ("nsub", '\u2284');
 272                         entities.Add ("sube", '\u2286');
 273                         entities.Add ("supe", '\u2287');
 274                         entities.Add ("oplus", '\u2295');
 275                         entities.Add ("otimes", '\u2297');
 276                         entities.Add ("perp", '\u22A5');
 277                         entities.Add ("sdot", '\u22C5');
 278                         entities.Add ("lceil", '\u2308');
 279                         entities.Add ("rceil", '\u2309');
 280                         entities.Add ("lfloor", '\u230A');
 281                         entities.Add ("rfloor", '\u230B');
 282                         entities.Add ("lang", '\u2329');
 283                         entities.Add ("rang", '\u232A');
 284                         entities.Add ("loz", '\u25CA');
 285                         entities.Add ("spades", '\u2660');
 286                         entities.Add ("clubs", '\u2663');
 287                         entities.Add ("hearts", '\u2665');
 288                         entities.Add ("diams", '\u2666');
 289                         entities.Add ("quot", '\u0022');
 290                         entities.Add ("amp", '\u0026');
 291                         entities.Add ("lt", '\u003C');
 292                         entities.Add ("gt", '\u003E');
 293                         entities.Add ("OElig", '\u0152');
 294                         entities.Add ("oelig", '\u0153');
 295                         entities.Add ("Scaron", '\u0160');
 296                         entities.Add ("scaron", '\u0161');
 297                         entities.Add ("Yuml", '\u0178');
 298                         entities.Add ("circ", '\u02C6');
 299                         entities.Add ("tilde", '\u02DC');
 300                         entities.Add ("ensp", '\u2002');
 301                         entities.Add ("emsp", '\u2003');
 302                         entities.Add ("thinsp", '\u2009');
 303                         entities.Add ("zwnj", '\u200C');
 304                         entities.Add ("zwj", '\u200D');
 305                         entities.Add ("lrm", '\u200E');
 306                         entities.Add ("rlm", '\u200F');
 307                         entities.Add ("ndash", '\u2013');
 308                         entities.Add ("mdash", '\u2014');
 309                         entities.Add ("lsquo", '\u2018');
 310                         entities.Add ("rsquo", '\u2019');
 311                         entities.Add ("sbquo", '\u201A');
 312                         entities.Add ("ldquo", '\u201C');
 313                         entities.Add ("rdquo", '\u201D');
 314                         entities.Add ("bdquo", '\u201E');
 315                         entities.Add ("dagger", '\u2020');
 316                         entities.Add ("Dagger", '\u2021');
 317                         entities.Add ("permil", '\u2030');
 318                         entities.Add ("lsaquo", '\u2039');
 319                         entities.Add ("rsaquo", '\u203A');
 320                         entities.Add ("euro", '\u20AC');
 321                 }
 322
 323                 public HttpUtility ()
 324                 {
 325                 }
 326
 327                 #endregion // Constructors
 328
 329                 #region Methods
 330
 331                 public static void HtmlAttributeEncode (string s, TextWriter output)
 332                 {
 333                         output.Write(HtmlAttributeEncode(s));
 334                 }
 335
 336                 public static string HtmlAttributeEncode (string s)
 337                 {
 338                         if (null == s)
 339                                 return null;
 340
 341                         if (s.IndexOf ('&') == -1 && s.IndexOf ('"') == -1)
 342                                 return s;
 343
 344                         StringBuilder output = new StringBuilder ();
 345                         foreach (char c in s)
 346                                 switch (c) {
 347                                 case '&' :
 348                                         output.Append ("&amp;");
 349                                         break;
 350                                 case '"' :
 351                                         output.Append ("&quot;");
 352                                         break;
 353                                 default:
 354                                         output.Append (c);
 355                                         break;
 356                                 }
 357
 358                         return output.ToString();
 359                 }
 360
 361                 public static string UrlDecode (string str)
 362                 {
 363                         return UrlDecode(str, Encoding.UTF8);
 364                 }
 365
 366                 private static char [] GetChars (MemoryStream b, Encoding e)
 367                 {
 368                         return e.GetChars (b.GetBuffer (), 0, (int) b.Length);
 369                 }
 370
 371                 public static string UrlDecode (string s, Encoding e)
 372                 {
 373                         if (null == s)
 374                                 return null;
 375
 376                         if (s.IndexOf ('%') == -1 && s.IndexOf ('+') == -1)
 377                                 return s;
 378
 379                         if (e == null)
 380                                 e = Encoding.UTF8;
 381
 382                         StringBuilder output = new StringBuilder ();
 383                         long len = s.Length;
 384                         NumberStyles hexa = NumberStyles.HexNumber;
 385                         MemoryStream bytes = new MemoryStream ();
 386
 387                         for (int i = 0; i < len; i++) {
 388                                 if (s [i] == '%' && i + 2 < len) {
 389                                         if (s [i + 1] == 'u' && i + 5 < len) {
 390                                                 if (bytes.Length > 0) {
 391                                                         output.Append (GetChars (bytes, e));
 392                                                         bytes.SetLength (0);
 393                                                 }
 394                                                 output.Append ((char) Int32.Parse (s.Substring (i + 2, 4), hexa));
 395                                                 i += 5;
 396                                         } else {
 397                                                 bytes.WriteByte ((byte) Int32.Parse (s.Substring (i + 1, 2), hexa));
 398                                                 i += 2;
 399                                         }
 400                                         continue;
 401                                 }
 402
 403                                 if (bytes.Length > 0) {
 404                                         output.Append (GetChars (bytes, e));
 405                                         bytes.SetLength (0);
 406                                 }
 407
 408                                 if (s [i] == '+') {
 409                                         output.Append (' ');
 410                                 } else {
 411                                         output.Append (s [i]);
 412                                 }
 413                         }
 414
 415                         if (bytes.Length > 0) {
 416                                 output.Append (GetChars (bytes, e));
 417                         }
 418
 419                         bytes = null;
 420                         return output.ToString ();
 421                 }
 422
 423                 public static string UrlDecode (byte [] bytes, Encoding e)
 424                 {
 425                         if (bytes == null)
 426                                 return null;
 427
 428                         return UrlDecode (bytes, 0, bytes.Length, e);
 429                 }
 430
 431                 private static int GetInt (byte b)
 432                 {
 433                         char c = Char.ToUpper ((char) b);
 434                         if (c >= '0' && c <= '9')
 435                                 return c - '0';
 436
 437                         if (c < 'A' || c > 'F')
 438                                 return 0;
 439
 440                         return (c - 'A' + 10);
 441                 }
 442
 443                 private static char GetChar (byte [] bytes, int offset, int length)
 444                 {
 445                         int value = 0;
 446                         int end = length + offset;
 447                         for (int i = offset; i < end; i++)
 448                                 value = (value << 4) + GetInt (bytes [offset]);
 449
 450                         return (char) value;
 451                 }
 452
 453                 public static string UrlDecode (byte [] bytes, int offset, int count, Encoding e)
 454                 {
 455                         if (bytes == null || count == 0)
 456                                 return null;
 457
 458                         if (bytes == null)
 459                                 throw new ArgumentNullException ("bytes");
 460
 461                         if (offset < 0 || offset > bytes.Length)
 462                                 throw new ArgumentOutOfRangeException ("offset");
 463
 464                         if (count < 0 || offset + count > bytes.Length)
 465                                 throw new ArgumentOutOfRangeException ("count");
 466
 467                         StringBuilder output = new StringBuilder ();
 468                         MemoryStream acc = new MemoryStream ();
 469
 470                         int end = count + offset;
 471                         for (int i = offset; i < end; i++) {
 472                                 if (bytes [i] == '%' && i + 2 < count) {
 473                                         if (bytes [i + 1] == (byte) 'u' && i + 5 < end) {
 474                                                 if (acc.Length > 0) {
 475                                                         output.Append (GetChars (acc, e));
 476                                                         acc.SetLength (0);
 477                                                 }
 478                                                 output.Append (GetChar (bytes, offset + 2, 4));
 479                                                 i += 5;
 480                                         } else {
 481                                                 acc.WriteByte ((byte) GetChar (bytes, offset + 1, 2));
 482                                                 i += 2;
 483                                         }
 484                                         continue;
 485                                 }
 486
 487                                 if (acc.Length > 0) {
 488                                         output.Append (GetChars (acc, e));
 489                                         acc.SetLength (0);
 490                                 }
 491
 492                                 if (bytes [i] == '+') {
 493                                         output.Append (' ');
 494                                 } else {
 495                                         output.Append ((char) bytes [i]);
 496                                 }
 497                         }
 498
 499                         if (acc.Length > 0) {
 500                                 output.Append (GetChars (acc, e));
 501                         }
 502
 503                         acc = null;
 504                         return output.ToString ();
 505                 }
 506
 507                 public static byte [] UrlDecodeToBytes (byte [] bytes)
 508                 {
 509                         if (bytes == null)
 510                                 return null;
 511
 512                         return UrlDecodeToBytes (bytes, 0, bytes.Length);
 513                 }
 514
 515                 public static byte [] UrlDecodeToBytes (string str)
 516                 {
 517                         return UrlDecodeToBytes (str, Encoding.UTF8);
 518                 }
 519
 520                 public static byte [] UrlDecodeToBytes (string str, Encoding e)
 521                 {
 522                         if (str == null)
 523                                 return null;
 524
 525                         if (e == null)
 526                                 throw new ArgumentNullException ("e");
 527
 528                         return UrlDecodeToBytes (e.GetBytes (str));
 529                 }
 530
 531                 public static byte [] UrlDecodeToBytes (byte [] bytes, int offset, int count)
 532                 {
 533                         if (bytes == null)
 534                                 return null;
 535
 536                         int len = bytes.Length;
 537                         if (offset < 0 || offset >= len)
 538                                 throw new ArgumentOutOfRangeException("offset");
 539
 540                         if (count < 0 || offset > len - count)
 541                                 throw new ArgumentOutOfRangeException("count");
 542
 543                         MemoryStream result = new MemoryStream ();
 544                         int end = offset + count;
 545                         for (int i = offset; i < end; i++){
 546                                 char c = (char) bytes [i];
 547                                 if (c == '+')
 548                                         c = ' ';
 549                                 else if (c == '%' && i < end - 2) {
 550                                         c = GetChar (bytes, i, 2);
 551                                         i += 2;
 552                                 }
 553                                 result.WriteByte ((byte) c);
 554                         }
 555
 556                         return result.ToArray ();
 557                 }
 558
 559                 public static string UrlEncode(string str)
 560                 {
 561                         return UrlEncode(str, Encoding.UTF8);
 562                 }
 563
 564                 public static string UrlEncode (string s, Encoding Enc)
 565                 {
 566                         if (s == null)
 567                                 return null;
 568
 569                         if (s == "")
 570                                 return "";
 571
 572                         byte [] bytes = Enc.GetBytes (s);
 573                         byte [] b =UrlEncodeToBytes (bytes, 0, bytes.Length);
 574                         return Encoding.ASCII.GetString (b,0,b.Length);
 575                 }
 576
 577                 public static string UrlEncode (byte [] bytes)
 578                 {
 579                         if (bytes == null)
 580                                 return null;
 581
 582                         if (bytes.Length == 0)
 583                                 return "";
 584
 585                         byte []b=UrlEncodeToBytes(bytes, 0, bytes.Length);
 586                         return Encoding.ASCII.GetString (b,0,b.Length);
 587                 }
 588
 589                 public static string UrlEncode (byte [] bytes, int offset, int count)
 590                 {
 591                         if (bytes == null)
 592                                 return null;
 593
 594                         if (bytes.Length == 0)
 595                                 return "";
 596
 597                         byte []b=UrlEncodeToBytes(bytes, offset, count);
 598                         return Encoding.ASCII.GetString (b,0,b.Length);
 599                 }
 600
 601                 public static byte [] UrlEncodeToBytes (string str)
 602                 {
 603                         return UrlEncodeToBytes (str, Encoding.UTF8);
 604                 }
 605
 606                 public static byte [] UrlEncodeToBytes (string str, Encoding e)
 607                 {
 608                         if (str == null)
 609                                 return null;
 610
 611                         if (str == "")
 612                                 return new byte [0];
 613
 614                         byte [] bytes = e.GetBytes (str);
 615                         return UrlEncodeToBytes (bytes, 0, bytes.Length);
 616                 }
 617
 618                 public static byte [] UrlEncodeToBytes (byte [] bytes)
 619                 {
 620                         if (bytes == null)
 621                                 return null;
 622
 623                         if (bytes.Length == 0)
 624                                 return new byte [0];
 625
 626                         return UrlEncodeToBytes (bytes, 0, bytes.Length);
 627                 }
 628
 629                 static char [] hexChars = "0123456789abcdef".ToCharArray ();
 630
 631                 public static byte [] UrlEncodeToBytes (byte [] bytes, int offset, int count)
 632                 {
 633                         if (bytes == null)
 634                                 return null;
 635
 636                         int len = bytes.Length;
 637                         if (len == 0)
 638                                 return new byte [0];
 639
 640                         if (offset < 0 || offset >= len)
 641                                 throw new ArgumentOutOfRangeException("offset");
 642
 643                         if (count < 0 || count > len - offset)
 644                                 throw new ArgumentOutOfRangeException("count");
 645
 646                         MemoryStream result = new MemoryStream ();
 647                         int end = offset + count;
 648                         for (int i = offset; i < end; i++) {
 649                                 char c = (char) bytes [i];
 650                                 if ((c == ' ') || (c < '0' && c != '-' && c != '.') ||
 651                                     (c < 'A' && c > '9') ||
 652                                     (c > 'Z' && c < 'a' && c != '_') ||
 653                                     (c > 'z')) {
 654                                         result.WriteByte ((byte) '%');
 655                                         int idx = ((int) c) >> 4;
 656                                         result.WriteByte ((byte) hexChars [idx]);
 657                                         idx = ((int) c) & 0x0F;
 658                                         result.WriteByte ((byte) hexChars [idx]);
 659                                 } else {
 660                                         result.WriteByte ((byte) c);
 661                                 }
 662                         }
 663
 664                         return result.ToArray ();
 665                 }
 666
 667                 public static string UrlEncodeUnicode (string str)
 668                 {
 669                         if (str == null)
 670                                 return null;
 671
 672                         StringBuilder result = new StringBuilder ();
 673                         int end = str.Length;
 674                         for (int i = 0; i < end; i++) {
 675                                 int idx;
 676                                 char c = str [i];
 677                                 if (c > 255) {
 678                                         result.Append ("%u");
 679                                         idx = ((int) c) >> 24;
 680                                         result.Append (hexChars [idx]);
 681                                         idx = (((int) c) >> 16) & 0x0F;
 682                                         result.Append (hexChars [idx]);
 683                                         idx = (((int) c) >> 8) & 0x0F;
 684                                         result.Append (hexChars [idx]);
 685                                         idx = ((int) c) & 0x0F;
 686                                         result.Append (hexChars [idx]);
 687                                         continue;
 688                                 }
 689
 690                                 if ((c == ' ') || (c < '0' && c != '-' && c != '.') ||
 691                                     (c < 'A' && c > '9') ||
 692                                     (c > 'Z' && c < 'a' && c != '_') ||
 693                                     (c > 'z')) {
 694                                         result.Append ('%');
 695                                         idx = ((int) c) >> 4;
 696                                         result.Append (hexChars [idx]);
 697                                         idx = ((int) c) & 0x0F;
 698                                         result.Append (hexChars [idx]);
 699                                         continue;
 700                                 }
 701
 702                                 result.Append (c);
 703                         }
 704
 705                         return result.ToString ();
 706                 }
 707
 708                 public static byte [] UrlEncodeUnicodeToBytes (string str)
 709                 {
 710                         if (str == null)
 711                                 return null;
 712
 713                         if (str == "")
 714                                 return new byte [0];
 715
 716                         return Encoding.ASCII.GetBytes (UrlEncodeUnicode (str));
 717                 }
 718
 719                 /// <summary>
 720                 /// Decodes an HTML-encoded string and returns the decoded string.
 721                 /// </summary>
 722                 /// <param name="s">The HTML string to decode. </param>
 723                 /// <returns>The decoded text.</returns>
 724                 public static string HtmlDecode (string s)
 725                 {
 726                         if (s == null)
 727                                 throw new ArgumentNullException ("s");
 728
 729                         if (s.IndexOf ('&') == -1)
 730                                 return s;
 731
 732                         bool insideEntity = false; // used to indicate that we are in a potential entity
 733                         string entity = String.Empty;
 734                         StringBuilder output = new StringBuilder ();
 735                         int len = s.Length;
 736
 737                         for (int i = 0; i < len; i++) {
 738                                 char c = s [i];
 739                                 switch (c) {
 740                                 case '&' :
 741                                         output.Append (entity);
 742                                         entity = "&";
 743                                         insideEntity = true;
 744                                         break;
 745                                 case ';' :
 746                                         if (!insideEntity) {
 747                                                 output.Append (c);
 748                                                 break;
 749                                         }
 750
 751                                         entity += c;
 752                                         int length = entity.Length;
 753                                         if (length >= 2 && entity[1] == '#' && entity[2] != ';')
 754                                                 entity = ((char) Int32.Parse (entity.Substring (2, entity.Length - 3))).ToString();
 755                                         else if (length > 1 && Entities.ContainsKey (entity.Substring (1, entity.Length - 2)))
 756                                                 entity = Entities [entity.Substring (1, entity.Length - 2)].ToString ();
 757
 758                                         output.Append (entity);
 759                                         entity = String.Empty;
 760                                         insideEntity = false;
 761                                         break;
 762                                 default :
 763                                         if (insideEntity)
 764                                                 entity += c;
 765                                         else
 766                                                 output.Append (c);
 767                                         break;
 768                                 }
 769                         }
 770                         output.Append (entity);
 771                         return output.ToString ();
 772                 }
 773
 774                 /// <summary>
 775                 /// Decodes an HTML-encoded string and sends the resulting output to a TextWriter output stream.
 776                 /// </summary>
 777                 /// <param name="s">The HTML string to decode</param>
 778                 /// <param name="output">The TextWriter output stream containing the decoded string. </param>
 779                 public static void HtmlDecode(string s, TextWriter output)
 780                 {
 781                         if (s != null)
 782                                 output.Write (HtmlDecode (s));
 783                 }
 784
 785                 /// <summary>
 786                 /// HTML-encodes a string and returns the encoded string.
 787                 /// </summary>
 788                 /// <param name="s">The text string to encode. </param>
 789                 /// <returns>The HTML-encoded text.</returns>
 790                 public static string HtmlEncode (string s)
 791                 {
 792                         if (s == null)
 793                                 return null;
 794
 795                         StringBuilder output = new StringBuilder ();
 796
 797                         foreach (char c in s)
 798                                 switch (c) {
 799                                 case '&' :
 800                                         output.Append ("&amp;");
 801                                         break;
 802                                 case '>' :
 803                                         output.Append ("&gt;");
 804                                         break;
 805                                 case '<' :
 806                                         output.Append ("&lt;");
 807                                         break;
 808                                 case '"' :
 809                                         output.Append ("&quot;");
 810                                         break;
 811                                 default:
 812                                         if ((int) c > 128) {
 813                                                 output.Append ("&#");
 814                                                 output.Append (((int) c).ToString ());
 815                                                 output.Append (";");
 816                                         }
 817                                         else
 818                                                 output.Append (c);
 819                                         break;
 820                                 }
 821                         return output.ToString ();
 822                 }
 823
 824                 /// <summary>
 825                 /// HTML-encodes a string and sends the resulting output to a TextWriter output stream.
 826                 /// </summary>
 827                 /// <param name="s">The string to encode. </param>
 828                 /// <param name="output">The TextWriter output stream containing the encoded string. </param>
 829                 public static void HtmlEncode(string s, TextWriter output)
 830                 {
 831                         if (s != null)
 832                                 output.Write (HtmlEncode (s));
 833                 }
 834
 835 #if NET_1_1
 836                 public string UrlPathEncode (string s)
 837                 {
 838                         if (s == null)
 839                                 return null;
 840
 841                         int idx = s.IndexOf ("?");
 842                         string s2 = null;
 843                         if (idx != -1) {
 844                                 s2 = s.Substring (0, idx-1);
 845                                 s2 = UrlEncode (s2) + s.Substring (idx);
 846                         } else {
 847                                 s2 = UrlEncode (s);
 848                         }
 849
 850                         return s2;
 851                 }
 852 #endif
 853                 #endregion // Methods
 854         }
 855 }