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
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
|
// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package path
import (
"errors"
"internal/bytealg"
"unicode/utf8"
)
// ErrBadPattern indicates a pattern was malformed.
var ErrBadPattern = errors.New("syntax error in pattern")
// Match reports whether name matches the shell pattern.
// The pattern syntax is:
//
// pattern:
// { term }
// term:
// '*' matches any sequence of non-/ characters
// '?' matches any single non-/ character
// '[' [ '^' ] { character-range } ']'
// character class (must be non-empty)
// c matches character c (c != '*', '?', '\\', '[')
// '\\' c matches character c
//
// character-range:
// c matches character c (c != '\\', '-', ']')
// '\\' c matches character c
// lo '-' hi matches character c for lo <= c <= hi
//
// Match requires pattern to match all of name, not just a substring.
// The only possible returned error is ErrBadPattern, when pattern
// is malformed.
//
func Match(pattern, name string) (matched bool, err error) {
Pattern:
for len(pattern) > 0 {
var star bool
var chunk string
star, chunk, pattern = scanChunk(pattern)
if star && chunk == "" {
// Trailing * matches rest of string unless it has a /.
return bytealg.IndexByteString(name, '/') < 0, nil
}
// Look for match at current position.
t, ok, err := matchChunk(chunk, name)
// if we're the last chunk, make sure we've exhausted the name
// otherwise we'll give a false result even if we could still match
// using the star
if ok && (len(t) == 0 || len(pattern) > 0) {
name = t
continue
}
if err != nil {
return false, err
}
if star {
// Look for match skipping i+1 bytes.
// Cannot skip /.
for i := 0; i < len(name) && name[i] != '/'; i++ {
t, ok, err := matchChunk(chunk, name[i+1:])
if ok {
// if we're the last chunk, make sure we exhausted the name
if len(pattern) == 0 && len(t) > 0 {
continue
}
name = t
continue Pattern
}
if err != nil {
return false, err
}
}
}
// Before returning false with no error,
// check that the remainder of the pattern is syntactically valid.
for len(pattern) > 0 {
_, chunk, pattern = scanChunk(pattern)
if _, _, err := matchChunk(chunk, ""); err != nil {
return false, err
}
}
return false, nil
}
return len(name) == 0, nil
}
// scanChunk gets the next segment of pattern, which is a non-star string
// possibly preceded by a star.
func scanChunk(pattern string) (star bool, chunk, rest string) {
for len(pattern) > 0 && pattern[0] == '*' {
pattern = pattern[1:]
star = true
}
inrange := false
var i int
Scan:
for i = 0; i < len(pattern); i++ {
switch pattern[i] {
case '\\':
// error check handled in matchChunk: bad pattern.
if i+1 < len(pattern) {
i++
}
case '[':
inrange = true
case ']':
inrange = false
case '*':
if !inrange {
break Scan
}
}
}
return star, pattern[0:i], pattern[i:]
}
// matchChunk checks whether chunk matches the beginning of s.
// If so, it returns the remainder of s (after the match).
// Chunk is all single-character operators: literals, char classes, and ?.
func matchChunk(chunk, s string) (rest string, ok bool, err error) {
// failed records whether the match has failed.
// After the match fails, the loop continues on processing chunk,
// checking that the pattern is well-formed but no longer reading s.
failed := false
for len(chunk) > 0 {
if !failed && len(s) == 0 {
failed = true
}
switch chunk[0] {
case '[':
// character class
var r rune
if !failed {
var n int
r, n = utf8.DecodeRuneInString(s)
s = s[n:]
}
chunk = chunk[1:]
// possibly negated
negated := false
if len(chunk) > 0 && chunk[0] == '^' {
negated = true
chunk = chunk[1:]
}
// parse all ranges
match := false
nrange := 0
for {
if len(chunk) > 0 && chunk[0] == ']' && nrange > 0 {
chunk = chunk[1:]
break
}
var lo, hi rune
if lo, chunk, err = getEsc(chunk); err != nil {
return "", false, err
}
hi = lo
if chunk[0] == '-' {
if hi, chunk, err = getEsc(chunk[1:]); err != nil {
return "", false, err
}
}
if lo <= r && r <= hi {
match = true
}
nrange++
}
if match == negated {
failed = true
}
case '?':
if !failed {
if s[0] == '/' {
failed = true
}
_, n := utf8.DecodeRuneInString(s)
s = s[n:]
}
chunk = chunk[1:]
case '\\':
chunk = chunk[1:]
if len(chunk) == 0 {
return "", false, ErrBadPattern
}
fallthrough
default:
if !failed {
if chunk[0] != s[0] {
failed = true
}
s = s[1:]
}
chunk = chunk[1:]
}
}
if failed {
return "", false, nil
}
return s, true, nil
}
// getEsc gets a possibly-escaped character from chunk, for a character class.
func getEsc(chunk string) (r rune, nchunk string, err error) {
if len(chunk) == 0 || chunk[0] == '-' || chunk[0] == ']' {
err = ErrBadPattern
return
}
if chunk[0] == '\\' {
chunk = chunk[1:]
if len(chunk) == 0 {
err = ErrBadPattern
return
}
}
r, n := utf8.DecodeRuneInString(chunk)
if r == utf8.RuneError && n == 1 {
err = ErrBadPattern
}
nchunk = chunk[n:]
if len(nchunk) == 0 {
err = ErrBadPattern
}
return
}
|
