summaryrefslogtreecommitdiffhomepage
path: root/shell/match.c
blob: 8b1ddacd5bdf82717b7e840b5499f0446a7f619b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
/*
 * ##/%% variable matching code ripped out of ash shell for code sharing
 *
 * This code is derived from software contributed to Berkeley by
 * Kenneth Almquist.
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 *
 * Copyright (c) 1989, 1991, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * Copyright (c) 1997-2005 Herbert Xu <herbert@gondor.apana.org.au>
 * was re-ported from NetBSD and debianized.
 */
#ifdef STANDALONE
# include <stdbool.h>
# include <stdio.h>
# include <stdlib.h>
# include <string.h>
# include <unistd.h>
#else
# include "libbb.h"
#endif
#include <fnmatch.h>
#include "match.h"

#define pmatch(a, b) !fnmatch((a), (b), 0)

char *scanleft(char *string, char *pattern, bool match_at_left)
{
	char c;
	char *loc = string;

	do {
		int match;
		const char *s;

		c = *loc;
		if (match_at_left) {
			*loc = '\0';
			s = string;
		} else
			s = loc;
		match = pmatch(pattern, s);
		*loc = c;

		if (match)
			return loc;

		loc++;
	} while (c);

	return NULL;
}

char *scanright(char *string, char *pattern, bool match_at_left)
{
	char c;
	char *loc = string + strlen(string);

	while (loc >= string) {
		int match;
		const char *s;

		c = *loc;
		if (match_at_left) {
			*loc = '\0';
			s = string;
		} else
			s = loc;
		match = pmatch(pattern, s);
		*loc = c;

		if (match)
			return loc;

		loc--;
	}

	return NULL;
}

#ifdef STANDALONE
int main(int argc, char *argv[])
{
	char *string;
	char *op;
	char *pattern;
	bool match_at_left;
	char *loc;

	int i;

	if (argc == 1) {
		puts(
			"Usage: match <test> [test...]\n\n"
			"Where a <test> is the form: <string><op><match>\n"
			"This is to test the shell ${var#val} expression type.\n\n"
			"e.g. `match 'abc#a*'` -> bc"
		);
		return 1;
	}

	for (i = 1; i < argc; ++i) {
		size_t off;
		scan_t scan;

		printf("'%s': ", argv[i]);

		string = strdup(argv[i]);
		off = strcspn(string, "#%");
		if (!off) {
			printf("invalid format\n");
			free(string);
			continue;
		}
		op = string + off;
		scan = pick_scan(op[0], op[1], &match_at_left);
		pattern = op + 1;
		if (op[0] == op[1])
			op[1] = '\0', ++pattern;
		op[0] = '\0';

		loc = scan(string, pattern, match_at_left);

		if (match_at_left) {
			printf("'%s'\n", loc);
		} else {
			*loc = '\0';
			printf("'%s'\n", string);
		}

		free(string);
	}

	return 0;
}
#endif