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
|
// Copyright 2009 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
import (
"os";
"syscall"
)
// Getwd returns a rooted path name corresponding to the
// current directory. If the current directory can be
// reached via multiple paths (due to symbolic links),
// Getwd may return any one of them.
func Getwd() (string, Error) {
// If the operating system provides a Getwd call, use it.
if syscall.ImplementsGetwd {
s, e := syscall.Getwd();
return s, ErrnoToError(e);
}
// Otherwise, we're trying to find our way back to ".".
dot, err := Stat(".");
if err != nil {
return "", err;
}
// Clumsy but widespread kludge:
// if $PWD is set and matches ".", use it.
pwd, _ := Getenv("PWD");
if len(pwd) > 0 && pwd[0] == '/' {
d, err := Stat(pwd);
if err == nil && d.Dev == dot.Dev && d.Ino == dot.Ino {
return pwd, nil
}
}
// Root is a special case because it has no parent
// and ends in a slash.
root, err := Stat("/");
if err != nil {
// Can't stat root - no hope.
return "", err;
}
if root.Dev == dot.Dev && root.Ino == dot.Ino {
return "/", nil
}
// General algorithm: find name in parent
// and then find name of parent. Each iteration
// adds /name to the beginning of pwd.
elem := make([]string, 0, 16);
pwd = "";
for parent := "..";; parent = "../" + parent {
if len(parent) >= 1024 { // Sanity check
return "", ENAMETOOLONG;
}
fd, err := Open(parent, O_RDONLY, 0);
if err != nil {
return "", err;
}
for {
names, err := fd.Readdirnames(100);
if err != nil {
fd.Close();
return "", err;
}
for i, name := range names {
d, err := Lstat(parent + "/" + name);
if d.Dev == dot.Dev && d.Ino == dot.Ino {
pwd = "/" + name + pwd;
goto Found;
}
}
}
fd.Close();
return "", ENOENT;
Found:
pd, err := fd.Stat();
if err != nil {
return "", err;
}
fd.Close();
if pd.Dev == root.Dev && pd.Ino == root.Ino {
break;
}
// Set up for next round.
dot = pd;
}
return pwd, nil
}
|
