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
|
// Copyright 2011 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 os
const (
PathSeparator = '\\' // OS-specific path separator
PathListSeparator = ';' // OS-specific path list separator
)
// IsPathSeparator reports whether c is a directory separator character.
func IsPathSeparator(c uint8) bool {
// NOTE: Windows accept / as path separator.
return c == '\\' || c == '/'
}
// basename removes trailing slashes and the leading
// directory name and drive letter from path name.
func basename(name string) string {
// Remove drive letter
if len(name) == 2 && name[1] == ':' {
name = "."
} else if len(name) > 2 && name[1] == ':' {
name = name[2:]
}
i := len(name) - 1
// Remove trailing slashes
for ; i > 0 && (name[i] == '/' || name[i] == '\\'); i-- {
name = name[:i]
}
// Remove leading directory name
for i--; i >= 0; i-- {
if name[i] == '/' || name[i] == '\\' {
name = name[i+1:]
break
}
}
return name
}
func isAbs(path string) (b bool) {
v := volumeName(path)
if v == "" {
return false
}
path = path[len(v):]
if path == "" {
return false
}
return IsPathSeparator(path[0])
}
func volumeName(path string) (v string) {
if len(path) < 2 {
return ""
}
// with drive letter
c := path[0]
if path[1] == ':' &&
('0' <= c && c <= '9' || 'a' <= c && c <= 'z' ||
'A' <= c && c <= 'Z') {
return path[:2]
}
// is it UNC
if l := len(path); l >= 5 && IsPathSeparator(path[0]) && IsPathSeparator(path[1]) &&
!IsPathSeparator(path[2]) && path[2] != '.' {
// first, leading `\\` and next shouldn't be `\`. its server name.
for n := 3; n < l-1; n++ {
// second, next '\' shouldn't be repeated.
if IsPathSeparator(path[n]) {
n++
// third, following something characters. its share name.
if !IsPathSeparator(path[n]) {
if path[n] == '.' {
break
}
for ; n < l; n++ {
if IsPathSeparator(path[n]) {
break
}
}
return path[:n]
}
break
}
}
}
return ""
}
func fromSlash(path string) string {
// Replace each '/' with '\\' if present
var pathbuf []byte
var lastSlash int
for i, b := range path {
if b == '/' {
if pathbuf == nil {
pathbuf = make([]byte, len(path))
}
copy(pathbuf[lastSlash:], path[lastSlash:i])
pathbuf[i] = '\\'
lastSlash = i + 1
}
}
if pathbuf == nil {
return path
}
copy(pathbuf[lastSlash:], path[lastSlash:])
return string(pathbuf)
}
func dirname(path string) string {
vol := volumeName(path)
i := len(path) - 1
for i >= len(vol) && !IsPathSeparator(path[i]) {
i--
}
dir := path[len(vol) : i+1]
last := len(dir) - 1
if last > 0 && IsPathSeparator(dir[last]) {
dir = dir[:last]
}
if dir == "" {
dir = "."
}
return vol + dir
}
// fixLongPath returns the extended-length (\\?\-prefixed) form of
// path if possible, in order to avoid the default 260 character file
// path limit imposed by Windows. If path is not easily converted to
// the extended-length form (for example, if path is a relative path
// or contains .. elements), fixLongPath returns path unmodified.
func fixLongPath(path string) string {
// The extended form begins with \\?\, as in
// \\?\c:\windows\foo.txt or \\?\UNC\server\share\foo.txt.
// The extended form disables evaluation of . and .. path
// elements and disables the interpretation of / as equivalent
// to \. The conversion here rewrites / to \ and elides
// . elements as well as trailing or duplicate separators. For
// simplicity it avoids the conversion entirely for relative
// paths or paths containing .. elements. For now,
// \\server\share paths are not converted to
// \\?\UNC\server\share paths because the rules for doing so
// are less well-specified.
//
// For details of \\?\ paths, see:
// https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx#maxpath
if len(path) == 0 || (len(path) >= 2 && path[:2] == `\\`) {
// Don't canonicalize UNC paths.
return path
}
if !isAbs(path) {
// Relative path
return path
}
const prefix = `\\?`
pathbuf := make([]byte, len(prefix)+len(path)+len(`\`))
copy(pathbuf, prefix)
n := len(path)
r, w := 0, len(prefix)
for r < n {
switch {
case IsPathSeparator(path[r]):
// empty block
r++
case path[r] == '.' && (r+1 == n || IsPathSeparator(path[r+1])):
// /./
r++
case r+1 < n && path[r] == '.' && path[r+1] == '.' && (r+2 == n || IsPathSeparator(path[r+2])):
// /../ is currently unhandled
return path
default:
pathbuf[w] = '\\'
w++
for ; r < n && !IsPathSeparator(path[r]); r++ {
pathbuf[w] = path[r]
w++
}
}
}
// A drive's root directory needs a trailing \
if w == len(`\\?\c:`) {
pathbuf[w] = '\\'
w++
}
return string(pathbuf[:w])
}
|
