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                                 return (String.Compare (pattern, text, ignorecase) == 0);
  56
  57                         return Match (ops, text, 0);
  58                 }
  59
  60                 public bool IsMatch (string text)
  61                 {
  62                         return IsMatch (text, ignore);
  63                 }
  64
  65                 public bool HasWildcard {
  66                         get { return hasWildcard; }
  67                 }
  68                 // private
  69
  70                 Op ops;         // the compiled pattern
  71                 bool ignore;    // ignore case
  72                 bool hasWildcard;
  73                 string pattern;
  74
  75                 private void Compile (string pattern)
  76                 {
  77                         if (pattern == null || pattern.IndexOfAny (InvalidChars) >= 0)
  78                                 throw new ArgumentException ("Invalid search pattern: '" + pattern + "'");
  79
  80                         if (pattern == "*") {   // common case
  81                                 ops = new Op (OpCode.True);
  82                                 hasWildcard = true;
  83                                 return;
  84                         }
  85
  86                         ops = null;
  87
  88                         int ptr = 0;
  89                         Op last_op = null;
  90                         while (ptr < pattern.Length) {
  91                                 Op op;
  92
  93                                 switch (pattern [ptr]) {
  94                                 case '?':
  95                                         op = new Op (OpCode.AnyChar);
  96                                         ++ ptr;
  97                                         hasWildcard = true;
  98                                         break;
  99
 100                                 case '*':
 101                                         op = new Op (OpCode.AnyString);
 102                                         ++ ptr;
 103                                         hasWildcard = true;
 104                                         break;
 105
 106                                 default:
 107                                         op = new Op (OpCode.ExactString);
 108                                         int end = pattern.IndexOfAny (WildcardChars, ptr);
 109                                         if (end < 0)
 110                                                 end = pattern.Length;
 111
 112                                         op.Argument = pattern.Substring (ptr, end - ptr);
 113                                         if (ignore)
 114                                                 op.Argument = op.Argument.ToLower ();
 115
 116                                         ptr = end;
 117                                         break;
 118                                 }
 119
 120                                 if (last_op == null)
 121                                         ops = op;
 122                                 else
 123                                         last_op.Next = op;
 124
 125                                 last_op = op;
 126                         }
 127
 128                         if (last_op == null)
 129                                 ops = new Op (OpCode.End);
 130                         else
 131                                 last_op.Next = new Op (OpCode.End);
 132                 }
 133
 134                 private bool Match (Op op, string text, int ptr)
 135                 {
 136                         while (op != null) {
 137                                 switch (op.Code) {
 138                                 case OpCode.True:
 139                                         return true;
 140
 141                                 case OpCode.End:
 142                                         if (ptr == text.Length)
 143                                                 return true;
 144
 145                                         return false;
 146
 147                                 case OpCode.ExactString:
 148                                         int length = op.Argument.Length;
 149                                         if (ptr + length > text.Length)
 150                                                 return false;
 151
 152                                         string str = text.Substring (ptr, length);
 153                                         if (ignore)
 154                                                 str = str.ToLower ();
 155
 156                                         if (str != op.Argument)
 157                                                 return false;
 158
 159                                         ptr += length;
 160                                         break;
 161
 162                                 case OpCode.AnyChar:
 163                                         if (++ ptr > text.Length)
 164                                                 return false;
 165                                         break;
 166
 167                                 case OpCode.AnyString:
 168                                         while (ptr <= text.Length) {
 169                                                 if (Match (op.Next, text, ptr))
 170                                                         return true;
 171
 172                                                 ++ ptr;
 173                                         }
 174
 175                                         return false;
 176                                 }
 177
 178                                 op = op.Next;
 179                         }
 180
 181                         return true;
 182                 }
 183
 184                 // private static
 185
 186                 internal static readonly char [] WildcardChars = { '*', '?' };
 187                 internal static readonly char [] InvalidChars = { Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar };
 188
 189                 private class Op {
 190                         public Op (OpCode code)
 191                         {
 192                                 this.Code = code;
 193                                 this.Argument = null;
 194                                 this.Next = null;
 195                         }
 196
 197                         public OpCode Code;
 198                         public string Argument;
 199                         public Op Next;
 200                 }
 201
 202                 private enum OpCode {
 203                         ExactString,            // literal
 204                         AnyChar,                // ?
 205                         AnyString,              // *
 206                         End,                    // end of pattern
 207                         True                    // always succeeds
 208                 };
 209         }
 210 }