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                 public bool IsMatch (string text)
  51                 {
  52                         if (!hasWildcard)
  53                                 return (String.Compare (pattern, text, ignore) == 0);
  54
  55                         return Match (ops, text, 0);
  56                 }
  57
  58                 public bool HasWildcard {
  59                         get { return hasWildcard; }
  60                 }
  61                 // private
  62
  63                 Op ops;         // the compiled pattern
  64                 bool ignore;    // ignore case
  65                 bool hasWildcard;
  66                 string pattern;
  67
  68                 private void Compile (string pattern)
  69                 {
  70                         if (pattern == null || pattern.IndexOfAny (InvalidChars) >= 0)
  71                                 throw new ArgumentException ("Invalid search pattern: '" + pattern + "'");
  72
  73                         if (pattern == "*") {   // common case
  74                                 ops = new Op (OpCode.True);
  75                                 hasWildcard = true;
  76                                 return;
  77                         }
  78
  79                         ops = null;
  80
  81                         int ptr = 0;
  82                         Op last_op = null;
  83                         while (ptr < pattern.Length) {
  84                                 Op op;
  85
  86                                 switch (pattern [ptr]) {
  87                                 case '?':
  88                                         op = new Op (OpCode.AnyChar);
  89                                         ++ ptr;
  90                                         hasWildcard = true;
  91                                         break;
  92
  93                                 case '*':
  94                                         op = new Op (OpCode.AnyString);
  95                                         ++ ptr;
  96                                         hasWildcard = true;
  97                                         break;
  98
  99                                 default:
 100                                         op = new Op (OpCode.ExactString);
 101                                         int end = pattern.IndexOfAny (WildcardChars, ptr);
 102                                         if (end < 0)
 103                                                 end = pattern.Length;
 104
 105                                         op.Argument = pattern.Substring (ptr, end - ptr);
 106                                         if (ignore)
 107                                                 op.Argument = op.Argument.ToLower ();
 108
 109                                         ptr = end;
 110                                         break;
 111                                 }
 112
 113                                 if (last_op == null)
 114                                         ops = op;
 115                                 else
 116                                         last_op.Next = op;
 117
 118                                 last_op = op;
 119                         }
 120
 121                         if (last_op == null)
 122                                 ops = new Op (OpCode.End);
 123                         else
 124                                 last_op.Next = new Op (OpCode.End);
 125                 }
 126
 127                 private bool Match (Op op, string text, int ptr)
 128                 {
 129                         while (op != null) {
 130                                 switch (op.Code) {
 131                                 case OpCode.True:
 132                                         return true;
 133
 134                                 case OpCode.End:
 135                                         if (ptr == text.Length)
 136                                                 return true;
 137
 138                                         return false;
 139
 140                                 case OpCode.ExactString:
 141                                         int length = op.Argument.Length;
 142                                         if (ptr + length > text.Length)
 143                                                 return false;
 144
 145                                         string str = text.Substring (ptr, length);
 146                                         if (ignore)
 147                                                 str = str.ToLower ();
 148
 149                                         if (str != op.Argument)
 150                                                 return false;
 151
 152                                         ptr += length;
 153                                         break;
 154
 155                                 case OpCode.AnyChar:
 156                                         if (++ ptr > text.Length)
 157                                                 return false;
 158                                         break;
 159
 160                                 case OpCode.AnyString:
 161                                         while (ptr <= text.Length) {
 162                                                 if (Match (op.Next, text, ptr))
 163                                                         return true;
 164
 165                                                 ++ ptr;
 166                                         }
 167
 168                                         return false;
 169                                 }
 170
 171                                 op = op.Next;
 172                         }
 173
 174                         return true;
 175                 }
 176
 177                 // private static
 178
 179                 internal static readonly char [] WildcardChars = { '*', '?' };
 180                 internal static readonly char [] InvalidChars = { Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar };
 181
 182                 private class Op {
 183                         public Op (OpCode code)
 184                         {
 185                                 this.Code = code;
 186                                 this.Argument = null;
 187                                 this.Next = null;
 188                         }
 189
 190                         public OpCode Code;
 191                         public string Argument;
 192                         public Op Next;
 193                 }
 194
 195                 private enum OpCode {
 196                         ExactString,            // literal
 197                         AnyChar,                // ?
 198                         AnyString,              // *
 199                         End,                    // end of pattern
 200                         True                    // always succeeds
 201                 };
 202         }
 203 }