chiark / gitweb /
Quick lick of paint before we really get started.
[anag] / wildcard.c
CommitLineData
6e403221 1/* -*-c-*-
2 *
6e403221 3 * Matches wildcard patterns
4 *
5 * (c) 2001 Mark Wooding
6 */
7
0279756e 8/*----- Licensing notice --------------------------------------------------*
6e403221 9 *
10 * This file is part of Anag: a simple wordgame helper.
11 *
12 * Anag is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
0279756e 16 *
6e403221 17 * Anag is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
0279756e 21 *
6e403221 22 * You should have received a copy of the GNU General Public License
23 * along with Anag; if not, write to the Free Software Foundation,
24 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25 */
26
6e403221 27/*----- Header files ------------------------------------------------------*/
28
29#include "anag.h"
30
31/*----- Data structures ---------------------------------------------------*/
32
33typedef struct node_wild {
34 node n;
35 const char *p;
36} node_wild;
37
38/*----- Main code ---------------------------------------------------------*/
39
40/* --- @match@ --- *
41 *
42 * Arguments: @const char *p@ = pointer to pattern string
43 * @const char *s@ = string to compare with
44 *
45 * Returns: Nonzero if the pattern matches the string.
46 *
47 * Use: Does simple wildcard matching. This is quite nasty and more
48 * than a little slow. Supports metacharacters `*', `?' and
49 * '['.
50 */
51
52static int match(const char *p, const char *s)
53{
54 for (;;) {
55 char pch = *p++, pche, sch;
56 int sense;
57
58 switch (pch) {
59 case '?':
60 if (!*s)
61 return (0);
62 s++;
63 break;
64 case '*':
65 if (!*p)
66 return (1);
67 while (*s) {
68 if (match(p, s))
69 return (1);
70 s++;
71 }
72 return (0);
73 case '[':
74 if (!*s)
75 return (0);
76 sch = *s++;
77 pch = *p++;
78 sense = 1;
79 if (pch == '^' || pch == '!') {
80 sense = !sense;
81 pch = *p++;
82 }
83 if (pch == ']') {
84 if (*p == '-' && p[1] && p[1] != ']') {
85 pche = p[1];
86 p += 2;
87 if (pch <= sch && sch <= pche)
88 goto class_match;
89 } else if (pch == sch)
90 goto class_match;
91 pch = *p++;
92 }
93 for (;; pch = *p++) {
94 if (!pch || pch == ']')
95 goto class_nomatch;
96 if (*p == '-' && p[1] && p[1] != ']') {
97 pche = p[1];
98 p += 2;
99 if (pch <= sch && sch <= pche)
100 goto class_match;
101 } else if (pch == sch)
102 goto class_match;
103 }
104 class_match:
105 if (!sense)
106 return (0);
107 for (;;) {
108 pch = *p++;
109 if (!pch)
110 return (0);
111 if (pch == ']')
112 break;
113 if (*p == '-' && p[1] && p[1] != ']')
114 p += 2;
115 }
116 break;
117 class_nomatch:
118 if (sense)
119 return (0);
120 break;
121 case '\\':
122 pch = *p++;
123 default:
124 if (pch != *s)
125 return (0);
126 if (!pch)
127 return (1);
128 s++;
129 break;
130 }
131 }
132}
133
134/* --- Node matcher --- */
135
136static int n_wild(node *nn, const char *p, size_t sz)
137{
138 node_wild *n = (node_wild *)nn;
139 return (match(n->p, p));
140}
141
142/* --- Node creation --- */
143
144node *wildcard(const char *const *av)
145{
146 node_wild *n = xmalloc(sizeof(*n));
147 n->n.func = n_wild;
148 n->p = av[0];
149 return (&n->n);
150}
151
152/*----- That's all, folks -------------------------------------------------*/