mcs/class/System/System.IO/SearchPattern.cs

   1 //
   2 // System.IO.SearchPattern2.cs: Filename glob support.
   3 //
   4 // Author:
   5 //   Dan Lewis (dihlewis@yahoo.co.uk)
   6 //
   7 // (C) 2002
   8 //
   9
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 // Copied from corlib/System.IO/SearchPatter.cs
  32 using System;
  33
  34 namespace System.IO {
  35
  36         // FIXME: there's a complication with this algorithm under windows.
  37         // the pattern '*.*' matches all files (i think . matches the extension),
  38         // whereas under UNIX it should only match files containing the '.' character.
  39
  40         class SearchPattern2 {
  41                 public SearchPattern2 (string pattern) : this (pattern, false) { }
  42
  43                 public SearchPattern2 (string pattern, bool ignore)
  44                 {
  45                         this.ignore = ignore;
  46                         this.pattern = pattern;
  47                         Compile (pattern);
  48                 }
  49
  50                 // OSX has a retarded case-insensitive yet case-aware filesystem
  51                 // so we need a overload in here for the Kqueue watcher
  52                 public bool IsMatch (string text, bool ignorecase)
  53                 {
  54                         if (!hasWildcard) {
  55                                 bool match = String.Compare (pattern, text, ignorecase) == 0;
  56                                 if (match)
  57                                         return true;
  58
  59                                 // This is a special case for FSW. It needs to match e.g. subdir/file.txt
  60                                 // when the pattern is "file.txt"
  61                                 int idx = text.LastIndexOf ('/');
  62                                 if (idx == -1)
  63                                         return false;
  64                                 idx++;
  65                                 if (idx == text.Length)
  66                                         return false;
  67
  68                                 return (String.Compare (pattern, text.Substring (idx), ignorecase) == 0);
  69                         }
  70
  71                         return Match (ops, text, 0);
  72                 }
  73
  74                 public bool IsMatch (string text)
  75                 {
  76                         return IsMatch (text, ignore);
  77                 }
  78
  79                 public bool HasWildcard {
  80                         get { return hasWildcard; }
  81                 }
  82                 // private
  83
  84                 Op ops;         // the compiled pattern
  85                 bool ignore;    // ignore case
  86                 bool hasWildcard;
  87                 string pattern;
  88
  89                 private void Compile (string pattern)
  90                 {
  91                         if (pattern == null || pattern.IndexOfAny (InvalidChars) >= 0)
  92                                 throw new ArgumentException ("Invalid search pattern: '" + pattern + "'");
  93
  94                         if (pattern == "*") {   // common case
  95                                 ops = new Op (OpCode.True);
  96                                 hasWildcard = true;
  97                                 return;
  98                         }
  99
 100                         ops = null;
 101
 102                         int ptr = 0;
 103                         Op last_op = null;
 104                         while (ptr < pattern.Length) {
 105                                 Op op;
 106
 107                                 switch (pattern [ptr]) {
 108                                 case '?':
 109                                         op = new Op (OpCode.AnyChar);
 110                                         ++ ptr;
 111                                         hasWildcard = true;
 112                                         break;
 113
 114                                 case '*':
 115                                         op = new Op (OpCode.AnyString);
 116                                         ++ ptr;
 117                                         hasWildcard = true;
 118                                         break;
 119
 120                                 default:
 121                                         op = new Op (OpCode.ExactString);
 122                                         int end = pattern.IndexOfAny (WildcardChars, ptr);
 123                                         if (end < 0)
 124                                                 end = pattern.Length;
 125
 126                                         op.Argument = pattern.Substring (ptr, end - ptr);
 127                                         if (ignore)
 128                                                 op.Argument = op.Argument.ToLower ();
 129
 130                                         ptr = end;
 131                                         break;
 132                                 }
 133
 134                                 if (last_op == null)
 135                                         ops = op;
 136                                 else
 137                                         last_op.Next = op;
 138
 139                                 last_op = op;
 140                         }
 141
 142                         if (last_op == null)
 143                                 ops = new Op (OpCode.End);
 144                         else
 145                                 last_op.Next = new Op (OpCode.End);
 146                 }
 147
 148                 private bool Match (Op op, string text, int ptr)
 149                 {
 150                         while (op != null) {
 151                                 switch (op.Code) {
 152                                 case OpCode.True:
 153                                         return true;
 154
 155                                 case OpCode.End:
 156                                         if (ptr == text.Length)
 157                                                 return true;
 158
 159                                         return false;
 160
 161                                 case OpCode.ExactString:
 162                                         int length = op.Argument.Length;
 163                                         if (ptr + length > text.Length)
 164                                                 return false;
 165
 166                                         string str = text.Substring (ptr, length);
 167                                         if (ignore)
 168                                                 str = str.ToLower ();
 169
 170                                         if (str != op.Argument)
 171                                                 return false;
 172
 173                                         ptr += length;
 174                                         break;
 175
 176                                 case OpCode.AnyChar:
 177                                         if (++ ptr > text.Length)
 178                                                 return false;
 179                                         break;
 180
 181                                 case OpCode.AnyString:
 182                                         while (ptr <= text.Length) {
 183                                                 if (Match (op.Next, text, ptr))
 184                                                         return true;
 185
 186                                                 ++ ptr;
 187                                         }
 188
 189                                         return false;
 190                                 }
 191
 192                                 op = op.Next;
 193                         }
 194
 195                         return true;
 196                 }
 197
 198                 // private static
 199
 200                 internal static readonly char [] WildcardChars = { '*', '?' };
 201                 internal static readonly char [] InvalidChars = { Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar };
 202
 203                 private class Op {
 204                         public Op (OpCode code)
 205                         {
 206                                 this.Code = code;
 207                                 this.Argument = null;
 208                                 this.Next = null;
 209                         }
 210
 211                         public OpCode Code;
 212                         public string Argument;
 213                         public Op Next;
 214                 }
 215
 216                 private enum OpCode {
 217                         ExactString,            // literal
 218                         AnyChar,                // ?
 219                         AnyString,              // *
 220                         End,                    // end of pattern
 221                         True                    // always succeeds
 222                 };
 223         }
 224 }