1 #include <linux/module.h> 1
2 #include <linux/glob.h>
3
4 /*
5 * The only reason this code can be compiled a
6 * ATA code that depends on it can be as well.
7 * both usually compiled in and the module ove
8 */
9 MODULE_DESCRIPTION("glob(7) matching");
10 MODULE_LICENSE("Dual MIT/GPL");
11
12 /**
13 * glob_match - Shell-style pattern matching,
14 * @pat: Shell-style pattern to match, e.g. "*
15 * @str: String to match. The pattern must ma
16 *
17 * Perform shell-style glob matching, returnin
18 * succeeds, or false (0) if it fails. Equiva
19 *
20 * Pattern metacharacters are ?, *, [ and \.
21 * (And, inside character classes, !, - and ].
22 *
23 * This is small and simple implementation int
24 * where a string is matched against a number
25 * does not preprocess the patterns. It is no
26 * is at most quadratic: strlen(@str)*strlen(@
27 *
28 * An example of the worst case is glob_match(
29 * it takes 6 passes over the pattern before m
30 *
31 * Like !fnmatch(@pat, @str, 0) and unlike the
32 * treat / or leading . specially; it isn't ac
33 *
34 * Note that according to glob(7) (and unlike
35 * are complemented by a leading !; this does
36 * [^a-z] syntax.
37 *
38 * An opening bracket without a matching close
39 */
40 bool __pure glob_match(char const *pat, char c
41 {
42 /*
43 * Backtrack to previous * on mismatch
44 * character later in the string. Bec
45 * (no exception for /), it can be eas
46 * never a need to backtrack multiple
47 */
48 char const *back_pat = NULL, *back_str
49
50 /*
51 * Loop over each token (character or
52 * it against the remaining unmatched
53 * on mismatch, or true after matching
54 */
55 for (;;) {
56 unsigned char c = *str++;
57 unsigned char d = *pat++;
58
59 switch (d) {
60 case '?': /* Wildcard: a
61 if (c == '\0')
62 return false;
63 break;
64 case '*': /* Any-length
65 if (*pat == '\0')
66 return true;
67 back_pat = pat;
68 back_str = --str;
69 break;
70 case '[': { /* Character c
71 bool match = false, in
72 char const *class = pa
73 unsigned char a = *cla
74
75 /*
76 * Iterate over each s
77 * A span is either a
78 * range a-b. The fir
79 */
80 do {
81 unsigned char
82
83 if (a == '\0')
84 goto l
85
86 if (class[0] =
87 b = cl
88
89 if (b
90
91
92 class
93 /* Any
94 }
95 match |= (a <=
96 } while ((a = *class++
97
98 if (match == inverted)
99 goto backtrack
100 pat = class;
101 }
102 break;
103 case '\\':
104 d = *pat++;
105 fallthrough;
106 default: /* Literal cha
107 literal:
108 if (c == d) {
109 if (d == '\0')
110 return
111 break;
112 }
113 backtrack:
114 if (c == '\0' || !back
115 return false;
116 /* Try again from last
117 pat = back_pat;
118 str = ++back_str;
119 break;
120 }
121 }
122 }
123 EXPORT_SYMBOL(glob_match);
124
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