mcs/class/System.Web/System.Web.Util/UrlUtils.cs

   1 /**\r
   2  * Namespace: System.Web.UI.Util\r
   3  * Class:     UrlUtils\r
   4  * \r
   5  * Author:  Gaurav Vaish\r
   6  * Maintainer: gvaish@iitk.ac.in\r
   7  * Status:  ??%\r
   8  * \r
   9  * (C) Gaurav Vaish (2001)\r
  10  */\r
  11 \r
  12 using System;\r
  13 using System.Collections;\r
  14 using System.Text;\r
  15 \r
  16 namespace System.Web.Util\r
  17 {\r
  18         internal class UrlUtils\r
  19         {\r
  20                 /*\r
  21                  * I could not find these functions in the class System.Uri\r
  22                  * Besides, an instance of Uri will not be formed until and unless the address is of\r
  23                  * the form protocol://[user:pass]host[:port]/[fullpath]\r
  24                  * ie, a protocol, and that too without any blanks before,\r
  25                  * is a must which may not be the case here.\r
  26                  * Important: Escaped URL is assumed here. nothing like .aspx?path=/something\r
  27                  * It should be .aspx?path=%2Fsomething\r
  28                  */\r
  29                 public static string GetProtocol(string url)\r
  30                 {\r
  31                         //Taking code from Java Class java.net.URL\r
  32                         if(url!=null)\r
  33                         {\r
  34                                 if(url.Length>0)\r
  35                                 {\r
  36                                         \r
  37                                         int i, start = 0, limit;\r
  38                                         limit = url.Length;\r
  39                                         char c;\r
  40                                         bool aRef = false;\r
  41                                         while( (limit > 0) && (url[limit-1] <= ' '))\r
  42                                         {\r
  43                                                 limit --;\r
  44                                         }\r
  45                                         while( (start < limit) && (url[start] <= ' '))\r
  46                                         {\r
  47                                                 start++;\r
  48                                         }\r
  49                                         if(RegionMatches(true, url, start, "url:", 0, 4))\r
  50                                         {\r
  51                                                 start += 4;\r
  52                                         }\r
  53                                         if(start < url.Length && url[start]=='#')\r
  54                                         {\r
  55                                                 aRef = true;\r
  56                                         }\r
  57                                         for(i = start; !aRef && (i < limit) && ((c=url[i]) != '/'); i++)\r
  58                                         {\r
  59                                                 if(c==':')\r
  60                                                 {\r
  61                                                         return url.Substring(start, i - start);\r
  62                                                 }\r
  63                                         }\r
  64                                 }\r
  65                         }\r
  66                         return String.Empty;\r
  67                 }\r
  68                 \r
  69                 public static bool IsRelativeUrl(string url)\r
  70                 {\r
  71                         if(url.IndexOf(':') != -1)\r
  72                                 return !IsRootUrl(url);\r
  73                         return true;\r
  74                 }\r
  75 \r
  76                 public static bool IsRootUrl(string url)\r
  77                 {\r
  78                         if(url!=null)\r
  79                         {\r
  80                                 if(url.Length>0)\r
  81                                 {\r
  82                                         return IsValidProtocol(GetProtocol(url).ToLower());\r
  83                                 }\r
  84                         }\r
  85                         return true;\r
  86                 }\r
  87                 \r
  88                 public static bool IsRooted(string path)\r
  89                 {\r
  90                         if(path!=null && path.Length > 0)\r
  91                         {\r
  92                                 return (path[0]=='/' || path[0]=='\\');\r
  93                         }\r
  94                         return false;\r
  95                 }\r
  96                 \r
  97                 public static void FailIfPhysicalPath(string path)\r
  98                 {\r
  99                         if(path!= null && path.Length > 0)\r
 100                         {\r
 101                                 if(path[0]==':' || path.StartsWith(@"\\"))\r
 102                                         throw new HttpException(HttpRuntime.FormatResourceString("Physical_path_not_allowed", path));\r
 103                         }\r
 104                 }\r
 105                 \r
 106                 public static string Combine(string basePath, string relPath)\r
 107                 {\r
 108                         FailIfPhysicalPath(relPath);\r
 109                         if(IsRootUrl(relPath))\r
 110                         {\r
 111                                 if(relPath != null && relPath.Length > 0)\r
 112                                 {\r
 113                                         return Reduce(relPath);\r
 114                                 }\r
 115                                 return String.Empty;\r
 116                         }\r
 117                         if(relPath.Length < 3 || relPath[0]!='~' || (relPath[0]!='/' && relPath[0]!='\\'))\r
 118                         {\r
 119                                 if(basePath==null || basePath.Length==1 || basePath[0]=='/')\r
 120                                         basePath = String.Empty;\r
 121                                 return Reduce(basePath + "/" + relPath);\r
 122                         }\r
 123                         string vPath = HttpRuntime.AppDomainAppVirtualPath;\r
 124                         if(vPath.Length <= 1)\r
 125                                 vPath = String.Empty;\r
 126                         return Reduce(vPath + "/" + relPath.Substring(2));\r
 127                 }\r
 128                 \r
 129                 public static bool IsValidProtocol(string protocol)\r
 130                 {\r
 131                         if(protocol.Length < 1)\r
 132                                 return false;\r
 133                         char c = protocol[0];\r
 134                         if(!Char.IsLetter(c))\r
 135                         {\r
 136                                 return false;\r
 137                         }\r
 138                         for(int i=1; i < protocol.Length; i++)\r
 139                         {\r
 140                                 c = protocol[i];\r
 141                                 if(!Char.IsLetterOrDigit(c) && c!='.' && c!='+' && c!='-')\r
 142                                 {\r
 143                                         return false;\r
 144                                 }\r
 145                         }\r
 146                         return true;\r
 147                 }\r
 148                 \r
 149                 /*\r
 150                  * MakeRelative("http://www.foo.com/bar1/bar2/file","http://www.foo.com/bar1")\r
 151                  * will return "bar2/file"\r
 152                  * while MakeRelative("http://www.foo.com/bar1/...","http://www.anotherfoo.com")\r
 153                  * return 'null' and so does the call\r
 154                  * MakeRelative("http://www.foo.com/bar1/bar2","http://www.foo.com/bar")\r
 155                  */\r
 156                 public static string MakeRelative(string fullUrl, string relativeTo)\r
 157                 {\r
 158                         if(fullUrl==relativeTo)\r
 159                         {\r
 160                                 return String.Empty;\r
 161                         }\r
 162                         if(fullUrl.IndexOf(relativeTo)!=0)\r
 163                         {\r
 164                                 return null;\r
 165                         }\r
 166                         string leftOver = fullUrl.Substring(relativeTo.Length);\r
 167                         if(!fullUrl.EndsWith("/") && !leftOver.StartsWith("/"))\r
 168                         {\r
 169                                 return null;\r
 170                         }\r
 171                         if(leftOver.StartsWith("/"))\r
 172                         {\r
 173                                 leftOver = leftOver.Substring(1);\r
 174                         }\r
 175                         return leftOver;\r
 176                 }\r
 177                 \r
 178                 /*\r
 179                  * Check JavaDocs for java.lang.String#RegionMatches(bool, int, String, int, int)\r
 180                  * Could not find anything similar in the System.String class\r
 181                  */\r
 182                 public static bool RegionMatches(bool ignoreCase, string source, int start, string match, int offset, int len)\r
 183                 {\r
 184                         if(source!=null || match!=null)\r
 185                         {\r
 186                                 if(source.Length>0 && match.Length>0)\r
 187                                 {\r
 188                                         char[] ta = source.ToCharArray();\r
 189                                         char[] pa = match.ToCharArray();\r
 190                                         if((offset < 0) || (start < 0) || (start > (source.Length - len)) || (offset > (match.Length - len)))\r
 191                                         {\r
 192                                                 return false;\r
 193                                         }\r
 194                                         while(len-- > 0)\r
 195                                         {\r
 196                                                 char c1 = ta[start++];\r
 197                                                 char c2 = pa[offset++];\r
 198                                                 if(c1==c2)\r
 199                                                         continue;\r
 200                                                 if(ignoreCase)\r
 201                                                 {\r
 202                                                         if(Char.ToUpper(c1)==Char.ToUpper(c2))\r
 203                                                                 continue;\r
 204                                                         // Check for Gregorian Calendar where the above may not hold good\r
 205                                                         if(Char.ToLower(c1)==Char.ToLower(c2))\r
 206                                                                 continue;\r
 207                                                 }\r
 208                                                 return false;\r
 209                                         }\r
 210                                         return true;\r
 211                                 }\r
 212                         }\r
 213                         return false;\r
 214                 }\r
 215 \r
 216                 public static string Reduce(string path)\r
 217                 {\r
 218                         int len = path.Length;\r
 219                         int dotIndex = -1;\r
 220                         path = path.Replace('\\','/');\r
 221                         while(true)\r
 222                         {\r
 223                                 dotIndex++;\r
 224                                 dotIndex = path.IndexOf('.', dotIndex);\r
 225                                 if(dotIndex < 0)\r
 226                                 {\r
 227                                         return path;\r
 228                                 }\r
 229                                 if(dotIndex != 0 && path[dotIndex -1]=='/')\r
 230                                         continue;\r
 231                                 if(dotIndex+1 == len || path[dotIndex+1]=='/')\r
 232                                         break;\r
 233                                 if(path[dotIndex+1]=='.')\r
 234                                         continue;\r
 235                                 if(dotIndex+2 == len || path[dotIndex+2]=='/')\r
 236                                         break;\r
 237                         }\r
 238                         ArrayList list = new ArrayList();\r
 239                         StringBuilder sb = new StringBuilder();\r
 240                         dotIndex = 0;\r
 241                         int temp;\r
 242                         do\r
 243                         {\r
 244                                 temp = dotIndex;\r
 245                                 dotIndex = path.IndexOf('/', temp + 1);\r
 246                                 if(dotIndex < 0)\r
 247                                         dotIndex = len;\r
 248                                 if( (dotIndex - temp) <= 3 && (dotIndex < 1 || path[dotIndex - 1]== '.') && ( (temp+1) >= len || path[temp+1]=='.') )\r
 249                                 {\r
 250                                         if(dotIndex - temp == 3)\r
 251                                                 continue;\r
 252                                         if(list.Count == 0)\r
 253                                                 throw new System.Web.HttpException(System.Web.HttpRuntime.FormatResourceString("Cannot_exit_up_top_directory"));\r
 254                                         sb.Length = (int) list[list.Count - 1];\r
 255                                         list.RemoveRange(list.Count - 1, 1);\r
 256                                         continue;\r
 257                                 }\r
 258                                 list.Add(sb.Length);\r
 259                                 sb.Append(path, temp, dotIndex - temp);\r
 260                         } while(dotIndex != len);\r
 261                         return sb.ToString();\r
 262                 }\r
 263                 \r
 264                 public static string GetDirectory(string url)\r
 265                 {\r
 266                         if(url==null)\r
 267                         {\r
 268                                 return null;\r
 269                         }\r
 270                         if(url.Length==0)\r
 271                         {\r
 272                                 return String.Empty;\r
 273                         }\r
 274                         url.Replace('\\','/');\r
 275                         string baseDir = url.Substring(0, url.LastIndexOf('/'));\r
 276                         if(baseDir.Length==0)\r
 277                         {\r
 278                                 baseDir = "/";\r
 279                         }\r
 280                         return baseDir;\r
 281                 }\r
 282         }\r
 283 }\r