mdw@git.distorted.org.uk Git - anag/blob - wildcard.c

   1 /* -*-c-*-
   2  *
   3  * $Id: wildcard.c,v 1.1 2001/02/04 17:14:42 mdw Exp $
   4  *
   5  * Matches wildcard patterns
   6  *
   7  * (c) 2001 Mark Wooding
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Anag: a simple wordgame helper.
  13  *
  14  * Anag is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * Anag is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with Anag; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 /*----- Revision history --------------------------------------------------*
  30  *
  31  * $Log: wildcard.c,v $
  32  * Revision 1.1  2001/02/04 17:14:42  mdw
  33  * Initial checkin
  34  *
  35  */
  36
  37 /*----- Header files ------------------------------------------------------*/
  38
  39 #include "anag.h"
  40
  41 /*----- Data structures ---------------------------------------------------*/
  42
  43 typedef struct node_wild {
  44   node n;
  45   const char *p;
  46 } node_wild;
  47
  48 /*----- Main code ---------------------------------------------------------*/
  49
  50 /* --- @match@ --- *
  51  *
  52  * Arguments:   @const char *p@ = pointer to pattern string
  53  *              @const char *s@ = string to compare with
  54  *
  55  * Returns:     Nonzero if the pattern matches the string.
  56  *
  57  * Use:         Does simple wildcard matching.  This is quite nasty and more
  58  *              than a little slow.  Supports metacharacters `*', `?' and
  59  *              '['.
  60  */
  61
  62 static int match(const char *p, const char *s)
  63 {
  64   for (;;) {
  65     char pch = *p++, pche, sch;
  66     int sense;
  67
  68     switch (pch) {
  69       case '?':
  70         if (!*s)
  71           return (0);
  72         s++;
  73         break;
  74       case '*':
  75         if (!*p)
  76           return (1);
  77         while (*s) {
  78           if (match(p, s))
  79             return (1);
  80           s++;
  81         }
  82         return (0);
  83       case '[':
  84         if (!*s)
  85           return (0);
  86         sch = *s++;
  87         pch = *p++;
  88         sense = 1;
  89         if (pch == '^' || pch == '!') {
  90           sense = !sense;
  91           pch = *p++;
  92         }
  93         if (pch == ']') {
  94           if (*p == '-' && p[1] && p[1] != ']') {
  95             pche = p[1];
  96             p += 2;
  97             if (pch <= sch && sch <= pche)
  98               goto class_match;
  99           } else if (pch == sch)
 100             goto class_match;
 101           pch = *p++;
 102         }
 103         for (;; pch = *p++) {
 104           if (!pch || pch == ']')
 105             goto class_nomatch;
 106           if (*p == '-' && p[1] && p[1] != ']') {
 107             pche = p[1];
 108             p += 2;
 109             if (pch <= sch && sch <= pche)
 110               goto class_match;
 111           } else if (pch == sch)
 112             goto class_match;
 113         }
 114       class_match:
 115         if (!sense)
 116           return (0);
 117         for (;;) {
 118           pch = *p++;
 119           if (!pch)
 120             return (0);
 121           if (pch == ']')
 122             break;
 123           if (*p == '-' && p[1] && p[1] != ']')
 124             p += 2;
 125         }
 126         break;
 127       class_nomatch:
 128         if (sense)
 129           return (0);
 130         break;
 131       case '\\':
 132         pch = *p++;
 133       default:
 134         if (pch != *s)
 135           return (0);
 136         if (!pch)
 137           return (1);
 138         s++;
 139         break;
 140     }
 141   }
 142 }
 143
 144 /* --- Node matcher --- */
 145
 146 static int n_wild(node *nn, const char *p, size_t sz)
 147 {
 148   node_wild *n = (node_wild *)nn;
 149   return (match(n->p, p));
 150 }
 151
 152 /* --- Node creation --- */
 153
 154 node *wildcard(const char *const *av)
 155 {
 156   node_wild *n = xmalloc(sizeof(*n));
 157   n->n.func = n_wild;
 158   n->p = av[0];
 159   return (&n->n);
 160 }
 161
 162 /*----- That's all, folks -------------------------------------------------*/