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go/src/os/stat_windows.go
Alex Brainman 48c4eeeed7 os: treat "nul" as DevNull file on windows
Also add more tests to test both nul and NUL on windows.

Fixes #24482

Change-Id: I3dfe68ec8de7f90ca869c1096dde0054df3c5cf6
Reviewed-on: https://go-review.googlesource.com/102457
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-03-25 08:33:21 +00:00

118 lines
2.9 KiB
Go

// 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"
)
// isNulName returns true if name is NUL file name.
// For example, it returns true for both "NUL" and "nul".
func isNulName(name string) bool {
if len(name) != 3 {
return false
}
if name[0] != 'n' && name[0] != 'N' {
return false
}
if name[1] != 'u' && name[1] != 'U' {
return false
}
if name[2] != 'l' && name[2] != 'L' {
return false
}
return true
}
// Stat returns the FileInfo structure describing file.
// If there is an error, it will be of type *PathError.
func (file *File) Stat() (FileInfo, error) {
if file == nil {
return nil, ErrInvalid
}
if file.isdir() {
// I don't know any better way to do that for directory
return Stat(file.dirinfo.path)
}
if isNulName(file.name) {
return &devNullStat, nil
}
ft, err := file.pfd.GetFileType()
if err != nil {
return nil, &PathError{"GetFileType", file.name, err}
}
switch ft {
case syscall.FILE_TYPE_PIPE, syscall.FILE_TYPE_CHAR:
return &fileStat{name: basename(file.name), filetype: ft}, nil
}
fs, err := newFileStatFromGetFileInformationByHandle(file.name, file.pfd.Sysfd)
if err != nil {
return nil, err
}
fs.filetype = ft
return fs, err
}
// statNolog implements Stat for Windows.
func statNolog(name string) (FileInfo, error) {
if len(name) == 0 {
return nil, &PathError{"Stat", name, syscall.Errno(syscall.ERROR_PATH_NOT_FOUND)}
}
if isNulName(name) {
return &devNullStat, nil
}
namep, err := syscall.UTF16PtrFromString(fixLongPath(name))
if err != nil {
return nil, &PathError{"Stat", name, err}
}
fs, err := newFileStatFromGetFileAttributesExOrFindFirstFile(name, namep)
if err != nil {
return nil, err
}
if !fs.isSymlink() {
err = fs.updatePathAndName(name)
if err != nil {
return nil, err
}
return fs, nil
}
// Use Windows I/O manager to dereference the symbolic link, as per
// https://blogs.msdn.microsoft.com/oldnewthing/20100212-00/?p=14963/
h, err := syscall.CreateFile(namep, 0, 0, nil,
syscall.OPEN_EXISTING, syscall.FILE_FLAG_BACKUP_SEMANTICS, 0)
if err != nil {
return nil, &PathError{"CreateFile", name, err}
}
defer syscall.CloseHandle(h)
return newFileStatFromGetFileInformationByHandle(name, h)
}
// lstatNolog implements Lstat for Windows.
func lstatNolog(name string) (FileInfo, error) {
if len(name) == 0 {
return nil, &PathError{"Lstat", name, syscall.Errno(syscall.ERROR_PATH_NOT_FOUND)}
}
if isNulName(name) {
return &devNullStat, nil
}
namep, err := syscall.UTF16PtrFromString(fixLongPath(name))
if err != nil {
return nil, &PathError{"Lstat", name, err}
}
fs, err := newFileStatFromGetFileAttributesExOrFindFirstFile(name, namep)
if err != nil {
return nil, err
}
err = fs.updatePathAndName(name)
if err != nil {
return nil, err
}
return fs, nil
}