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author | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
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committer | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
commit | 554fd8c5195424bdbcabf5de30fdc183aba391bd (patch) | |
tree | 976dc5ab7fddf506dadce60ae936f43f58787092 /libgo/go/os/getwd.go | |
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Diffstat (limited to 'libgo/go/os/getwd.go')
-rw-r--r-- | libgo/go/os/getwd.go | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/libgo/go/os/getwd.go b/libgo/go/os/getwd.go new file mode 100644 index 000000000..49aaea865 --- /dev/null +++ b/libgo/go/os/getwd.go @@ -0,0 +1,92 @@ +// 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 ( + "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, NewSyscallError("getwd", 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. + 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 _, name := range names { + d, _ := 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 +} |