chiark - git - mdw - anag/blame

Commit	Line	Data
6e403221	1	/* --c--
6e403221	2	*
	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
	33	typedef 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
	52	static 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
136	static 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
144	node 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 -------------------------------------------------/