blob: fa98142484b015f848141a8300329582e68f7a22 [file] [log] [blame]
// Copyright 2013 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 vfs
import (
pathpkg "path"
// OS returns an implementation of FileSystem reading from the
// tree rooted at root. Recording a root is convenient everywhere
// but necessary on Windows, because the slash-separated path
// passed to Open has no way to specify a drive letter. Using a root
// lets code refer to OS(`c:\`), OS(`d:\`) and so on.
func OS(root string) FileSystem {
return osFS(root)
type osFS string
func (root osFS) String() string { return "os(" + string(root) + ")" }
func (root osFS) resolve(path string) string {
// Clean the path so that it cannot possibly begin with ../.
// If it did, the result of filepath.Join would be outside the
// tree rooted at root. We probably won't ever see a path
// with .. in it, but be safe anyway.
path = pathpkg.Clean("/" + path)
return filepath.Join(string(root), path)
func (root osFS) Open(path string) (ReadSeekCloser, error) {
f, err := os.Open(root.resolve(path))
if err != nil {
return nil, err
fi, err := f.Stat()
if err != nil {
return nil, err
if fi.IsDir() {
return nil, fmt.Errorf("Open: %s is a directory", path)
return f, nil
func (root osFS) Lstat(path string) (os.FileInfo, error) {
return os.Lstat(root.resolve(path))
func (root osFS) Stat(path string) (os.FileInfo, error) {
return os.Stat(root.resolve(path))
func (root osFS) ReadDir(path string) ([]os.FileInfo, error) {
return ioutil.ReadDir(root.resolve(path)) // is sorted