sys/lib/libkern/pmatch.c

   1 /*      $NetBSD: pmatch.c,v 1.5 2005/12/11 12:24:37 christos Exp $      */
   2
   3 /*-
   4  * Copyright (c) 1980, 1991 The Regents of the University of California.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/param.h>
  33 #include <lib/libkern/libkern.h>
  34 /*
  35  * pmatch():
  36  *      Return 2 on exact match.
  37  *      Return 1 on substring match.
  38  *      Return 0 on no match.
  39  *      Return -1 on error.
  40  * *estr will point to the end of thelongest exact or substring match.
  41  */
  42 int
  43 pmatch(const char *string, const char *pattern, const char **estr)
  44 {
  45         u_char stringc, patternc, rangec;
  46         int match, negate_range;
  47         const char *oestr, *pestr, *testr;
  48
  49         if (estr == NULL)
  50                 estr = &testr;
  51
  52         for (;; ++string) {
  53                 stringc = *string;
  54                 switch (patternc = *pattern++) {
  55                 case 0:
  56                         *estr = string;
  57                         return stringc == '\0' ? 2 : 1;
  58                 case '?':
  59                         if (stringc == '\0')
  60                                 return 0;
  61                         *estr = string;
  62                         break;
  63                 case '*':
  64                         if (!*pattern) {
  65                                 while (*string)
  66                                         string++;
  67                                 *estr = string;
  68                                 return 2;
  69                         }
  70                         oestr = *estr;
  71                         pestr = NULL;
  72
  73                         do {
  74                                 switch (pmatch(string, pattern, estr)) {
  75                                 case -1:
  76                                         return -1;
  77                                 case 0:
  78                                         break;
  79                                 case 1:
  80                                         pestr = *estr;
  81                                         break;
  82                                 case 2:
  83                                         return 2;
  84                                 default:
  85                                         return -1;
  86                                 }
  87                                 *estr = string;
  88                         }
  89                         while (*string++);
  90
  91                         if (pestr) {
  92                                 *estr = pestr;
  93                                 return 1;
  94                         } else {
  95                                 *estr = oestr;
  96                                 return 0;
  97                         }
  98
  99                 case '[':
 100                         match = 0;
 101                         if ((negate_range = (*pattern == '^')) != 0)
 102                                 pattern++;
 103                         while ((rangec = *pattern++) != '\0') {
 104                                 if (rangec == ']')
 105                                         break;
 106                                 if (match)
 107                                         continue;
 108                                 if (rangec == '-' && *(pattern - 2) != '[' &&
 109                                     *pattern != ']') {
 110                                         match =
 111                                             stringc <= (u_char)*pattern &&
 112                                             (u_char)*(pattern - 2) <= stringc;
 113                                         pattern++;
 114                                 } else
 115                                         match = (stringc == rangec);
 116                         }
 117                         if (rangec == 0)
 118                                 return -1;
 119                         if (match == negate_range)
 120                                 return 0;
 121                         *estr = string;
 122                         break;
 123                 default:
 124                         if (patternc != stringc)
 125                                 return 0;
 126                         *estr = string;
 127                         break;
 128                 }
 129         }
 130 }