source/lib/regex.cpp

   1 /* Copyright (C) 2020 Wildfire Games.
   2  *
   3  * Permission is hereby granted, free of charge, to any person obtaining
   4  * a copy of this software and associated documentation files (the
   5  * "Software"), to deal in the Software without restriction, including
   6  * without limitation the rights to use, copy, modify, merge, publish,
   7  * distribute, sublicense, and/or sell copies of the Software, and to
   8  * permit persons to whom the Software is furnished to do so, subject to
   9  * the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included
  12  * in all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  15  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  16  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  17  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
  18  * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  19  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  20  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  21  */
  22
  23 // minimal regex implementation
  24
  25 #include "precompiled.h"
  26
  27 #include <cwctype>
  28
  29 int match_wildcard(const wchar_t* s, const wchar_t* w)
  30 {
  31         if(!w)
  32                 return 1;
  33
  34         // saved position in both strings, used to expand '*':
  35         // s2 is advanced until match.
  36         // initially 0 - we abort on mismatch before the first '*'.
  37         const wchar_t* s2 = 0;
  38         const wchar_t* w2 = 0;
  39
  40         while(*s)
  41         {
  42                 const wchar_t wc = *w;
  43                 if(wc == '*')
  44                 {
  45                         // wildcard string ended with * => match.
  46                         if(*++w == '\0')
  47                                 return 1;
  48
  49                         w2 = w;
  50                         s2 = s+1;
  51                 }
  52                 // match one character
  53                 else if(towupper(wc) == towupper(*s) || wc == '?')
  54                 {
  55                         w++;
  56                         s++;
  57                 }
  58                 // mismatched character
  59                 else
  60                 {
  61                         // no '*' found yet => mismatch.
  62                         if(!s2)
  63                                 return 0;
  64
  65                         // resume at previous position+1
  66                         w = w2;
  67                         s = s2++;
  68                 }
  69         }
  70
  71         // strip trailing * in wildcard string
  72         while(*w == '*')
  73                 w++;
  74
  75         return (*w == '\0');
  76 }