| // 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 ( |
| "fmt" |
| "go/build" |
| "io/ioutil" |
| "os" |
| pathpkg "path" |
| "path/filepath" |
| "runtime" |
| ) |
| |
| // 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 { |
| var t RootType |
| switch { |
| case root == runtime.GOROOT(): |
| t = RootTypeGoRoot |
| case isGoPath(root): |
| t = RootTypeGoPath |
| } |
| return osFS{rootPath: root, rootType: t} |
| } |
| |
| type osFS struct { |
| rootPath string |
| rootType RootType |
| } |
| |
| func isGoPath(path string) bool { |
| for _, bp := range filepath.SplitList(build.Default.GOPATH) { |
| for _, gp := range filepath.SplitList(path) { |
| if bp == gp { |
| return true |
| } |
| } |
| } |
| return false |
| } |
| |
| func (root osFS) String() string { return "os(" + root.rootPath + ")" } |
| |
| // RootType returns the root type for the filesystem. |
| // |
| // Note that we ignore the path argument because roottype is a property of |
| // this filesystem. But for other filesystems, the roottype might need to be |
| // dynamically deduced at call time. |
| func (root osFS) RootType(path string) RootType { |
| return root.rootType |
| } |
| |
| 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(root.rootPath, 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 { |
| f.Close() |
| return nil, err |
| } |
| if fi.IsDir() { |
| f.Close() |
| 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 |
| } |