xref: /netbsd-src/sys/lib/libkern/pmatch.c (revision 48360965f30c307b6836d0d898d15ce6c1d9b387)
1 /*	$NetBSD: pmatch.c,v 1.6 2009/03/14 21:04:24 dsl 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 }
131