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Diffstat (limited to 'src/pkg/path/filepath/path.go')
| -rw-r--r-- | src/pkg/path/filepath/path.go | 467 |
1 files changed, 0 insertions, 467 deletions
diff --git a/src/pkg/path/filepath/path.go b/src/pkg/path/filepath/path.go deleted file mode 100644 index 71603cc59..000000000 --- a/src/pkg/path/filepath/path.go +++ /dev/null @@ -1,467 +0,0 @@ -// 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 filepath implements utility routines for manipulating filename paths -// in a way compatible with the target operating system-defined file paths. -package filepath - -import ( - "errors" - "os" - "sort" - "strings" -) - -// A lazybuf is a lazily constructed path buffer. -// It supports append, reading previously appended bytes, -// and retrieving the final string. It does not allocate a buffer -// to hold the output until that output diverges from s. -type lazybuf struct { - path string - buf []byte - w int - volAndPath string - volLen int -} - -func (b *lazybuf) index(i int) byte { - if b.buf != nil { - return b.buf[i] - } - return b.path[i] -} - -func (b *lazybuf) append(c byte) { - if b.buf == nil { - if b.w < len(b.path) && b.path[b.w] == c { - b.w++ - return - } - b.buf = make([]byte, len(b.path)) - copy(b.buf, b.path[:b.w]) - } - b.buf[b.w] = c - b.w++ -} - -func (b *lazybuf) string() string { - if b.buf == nil { - return b.volAndPath[:b.volLen+b.w] - } - return b.volAndPath[:b.volLen] + string(b.buf[:b.w]) -} - -const ( - Separator = os.PathSeparator - ListSeparator = os.PathListSeparator -) - -// Clean returns the shortest path name equivalent to path -// by purely lexical processing. It applies the following rules -// iteratively until no further processing can be done: -// -// 1. Replace multiple Separator elements with a single one. -// 2. Eliminate each . path name element (the current directory). -// 3. Eliminate each inner .. path name element (the parent directory) -// along with the non-.. element that precedes it. -// 4. Eliminate .. elements that begin a rooted path: -// that is, replace "/.." by "/" at the beginning of a path, -// assuming Separator is '/'. -// -// The returned path ends in a slash only if it represents a root directory, -// such as "/" on Unix or `C:\` on Windows. -// -// If the result of this process is an empty string, Clean -// returns the string ".". -// -// See also Rob Pike, ``Lexical File Names in Plan 9 or -// Getting Dot-Dot Right,'' -// http://plan9.bell-labs.com/sys/doc/lexnames.html -func Clean(path string) string { - originalPath := path - volLen := volumeNameLen(path) - path = path[volLen:] - if path == "" { - if volLen > 1 && originalPath[1] != ':' { - // should be UNC - return FromSlash(originalPath) - } - return originalPath + "." - } - rooted := os.IsPathSeparator(path[0]) - - // Invariants: - // reading from path; r is index of next byte to process. - // writing to buf; w is index of next byte to write. - // dotdot is index in buf where .. must stop, either because - // it is the leading slash or it is a leading ../../.. prefix. - n := len(path) - out := lazybuf{path: path, volAndPath: originalPath, volLen: volLen} - r, dotdot := 0, 0 - if rooted { - out.append(Separator) - r, dotdot = 1, 1 - } - - for r < n { - switch { - case os.IsPathSeparator(path[r]): - // empty path element - r++ - case path[r] == '.' && (r+1 == n || os.IsPathSeparator(path[r+1])): - // . element - r++ - case path[r] == '.' && path[r+1] == '.' && (r+2 == n || os.IsPathSeparator(path[r+2])): - // .. element: remove to last separator - r += 2 - switch { - case out.w > dotdot: - // can backtrack - out.w-- - for out.w > dotdot && !os.IsPathSeparator(out.index(out.w)) { - out.w-- - } - case !rooted: - // cannot backtrack, but not rooted, so append .. element. - if out.w > 0 { - out.append(Separator) - } - out.append('.') - out.append('.') - dotdot = out.w - } - default: - // real path element. - // add slash if needed - if rooted && out.w != 1 || !rooted && out.w != 0 { - out.append(Separator) - } - // copy element - for ; r < n && !os.IsPathSeparator(path[r]); r++ { - out.append(path[r]) - } - } - } - - // Turn empty string into "." - if out.w == 0 { - out.append('.') - } - - return FromSlash(out.string()) -} - -// ToSlash returns the result of replacing each separator character -// in path with a slash ('/') character. Multiple separators are -// replaced by multiple slashes. -func ToSlash(path string) string { - if Separator == '/' { - return path - } - return strings.Replace(path, string(Separator), "/", -1) -} - -// FromSlash returns the result of replacing each slash ('/') character -// in path with a separator character. Multiple slashes are replaced -// by multiple separators. -func FromSlash(path string) string { - if Separator == '/' { - return path - } - return strings.Replace(path, "/", string(Separator), -1) -} - -// SplitList splits a list of paths joined by the OS-specific ListSeparator, -// usually found in PATH or GOPATH environment variables. -// Unlike strings.Split, SplitList returns an empty slice when passed an empty string. -func SplitList(path string) []string { - return splitList(path) -} - -// Split splits path immediately following the final Separator, -// separating it into a directory and file name component. -// If there is no Separator in path, Split returns an empty dir -// and file set to path. -// The returned values have the property that path = dir+file. -func Split(path string) (dir, file string) { - vol := VolumeName(path) - i := len(path) - 1 - for i >= len(vol) && !os.IsPathSeparator(path[i]) { - i-- - } - return path[:i+1], path[i+1:] -} - -// Join joins any number of path elements into a single path, adding -// a Separator if necessary. The result is Cleaned, in particular -// all empty strings are ignored. -func Join(elem ...string) string { - for i, e := range elem { - if e != "" { - return Clean(strings.Join(elem[i:], string(Separator))) - } - } - return "" -} - -// Ext returns the file name extension used by path. -// The extension is the suffix beginning at the final dot -// in the final element of path; it is empty if there is -// no dot. -func Ext(path string) string { - for i := len(path) - 1; i >= 0 && !os.IsPathSeparator(path[i]); i-- { - if path[i] == '.' { - return path[i:] - } - } - return "" -} - -// EvalSymlinks returns the path name after the evaluation of any symbolic -// links. -// If path is relative the result will be relative to the current directory, -// unless one of the components is an absolute symbolic link. -func EvalSymlinks(path string) (string, error) { - return evalSymlinks(path) -} - -// Abs returns an absolute representation of path. -// If the path is not absolute it will be joined with the current -// working directory to turn it into an absolute path. The absolute -// path name for a given file is not guaranteed to be unique. -func Abs(path string) (string, error) { - if IsAbs(path) { - return Clean(path), nil - } - wd, err := os.Getwd() - if err != nil { - return "", err - } - return Join(wd, path), nil -} - -// Rel returns a relative path that is lexically equivalent to targpath when -// joined to basepath with an intervening separator. That is, -// Join(basepath, Rel(basepath, targpath)) is equivalent to targpath itself. -// On success, the returned path will always be relative to basepath, -// even if basepath and targpath share no elements. -// An error is returned if targpath can't be made relative to basepath or if -// knowing the current working directory would be necessary to compute it. -func Rel(basepath, targpath string) (string, error) { - baseVol := VolumeName(basepath) - targVol := VolumeName(targpath) - base := Clean(basepath) - targ := Clean(targpath) - if targ == base { - return ".", nil - } - base = base[len(baseVol):] - targ = targ[len(targVol):] - if base == "." { - base = "" - } - // Can't use IsAbs - `\a` and `a` are both relative in Windows. - baseSlashed := len(base) > 0 && base[0] == Separator - targSlashed := len(targ) > 0 && targ[0] == Separator - if baseSlashed != targSlashed || baseVol != targVol { - return "", errors.New("Rel: can't make " + targ + " relative to " + base) - } - // Position base[b0:bi] and targ[t0:ti] at the first differing elements. - bl := len(base) - tl := len(targ) - var b0, bi, t0, ti int - for { - for bi < bl && base[bi] != Separator { - bi++ - } - for ti < tl && targ[ti] != Separator { - ti++ - } - if targ[t0:ti] != base[b0:bi] { - break - } - if bi < bl { - bi++ - } - if ti < tl { - ti++ - } - b0 = bi - t0 = ti - } - if base[b0:bi] == ".." { - return "", errors.New("Rel: can't make " + targ + " relative to " + base) - } - if b0 != bl { - // Base elements left. Must go up before going down. - seps := strings.Count(base[b0:bl], string(Separator)) - size := 2 + seps*3 - if tl != t0 { - size += 1 + tl - t0 - } - buf := make([]byte, size) - n := copy(buf, "..") - for i := 0; i < seps; i++ { - buf[n] = Separator - copy(buf[n+1:], "..") - n += 3 - } - if t0 != tl { - buf[n] = Separator - copy(buf[n+1:], targ[t0:]) - } - return string(buf), nil - } - return targ[t0:], nil -} - -// SkipDir is used as a return value from WalkFuncs to indicate that -// the directory named in the call is to be skipped. It is not returned -// as an error by any function. -var SkipDir = errors.New("skip this directory") - -// WalkFunc is the type of the function called for each file or directory -// visited by Walk. The path argument contains the argument to Walk as a -// prefix; that is, if Walk is called with "dir", which is a directory -// containing the file "a", the walk function will be called with argument -// "dir/a". The info argument is the os.FileInfo for the named path. -// -// If there was a problem walking to the file or directory named by path, the -// incoming error will describe the problem and the function can decide how -// to handle that error (and Walk will not descend into that directory). If -// an error is returned, processing stops. The sole exception is that if path -// is a directory and the function returns the special value SkipDir, the -// contents of the directory are skipped and processing continues as usual on -// the next file. -type WalkFunc func(path string, info os.FileInfo, err error) error - -var lstat = os.Lstat // for testing - -// walk recursively descends path, calling w. -func walk(path string, info os.FileInfo, walkFn WalkFunc) error { - err := walkFn(path, info, nil) - if err != nil { - if info.IsDir() && err == SkipDir { - return nil - } - return err - } - - if !info.IsDir() { - return nil - } - - names, err := readDirNames(path) - if err != nil { - return walkFn(path, info, err) - } - - for _, name := range names { - filename := Join(path, name) - fileInfo, err := lstat(filename) - if err != nil { - if err := walkFn(filename, fileInfo, err); err != nil && err != SkipDir { - return err - } - } else { - err = walk(filename, fileInfo, walkFn) - if err != nil { - if !fileInfo.IsDir() || err != SkipDir { - return err - } - } - } - } - return nil -} - -// Walk walks the file tree rooted at root, calling walkFn for each file or -// directory in the tree, including root. All errors that arise visiting files -// and directories are filtered by walkFn. The files are walked in lexical -// order, which makes the output deterministic but means that for very -// large directories Walk can be inefficient. -// Walk does not follow symbolic links. -func Walk(root string, walkFn WalkFunc) error { - info, err := os.Lstat(root) - if err != nil { - return walkFn(root, nil, err) - } - return walk(root, info, walkFn) -} - -// readDirNames reads the directory named by dirname and returns -// a sorted list of directory entries. -func readDirNames(dirname string) ([]string, error) { - f, err := os.Open(dirname) - if err != nil { - return nil, err - } - names, err := f.Readdirnames(-1) - f.Close() - if err != nil { - return nil, err - } - sort.Strings(names) - return names, nil -} - -// Base returns the last element of path. -// Trailing path separators are removed before extracting the last element. -// If the path is empty, Base returns ".". -// If the path consists entirely of separators, Base returns a single separator. -func Base(path string) string { - if path == "" { - return "." - } - // Strip trailing slashes. - for len(path) > 0 && os.IsPathSeparator(path[len(path)-1]) { - path = path[0 : len(path)-1] - } - // Throw away volume name - path = path[len(VolumeName(path)):] - // Find the last element - i := len(path) - 1 - for i >= 0 && !os.IsPathSeparator(path[i]) { - i-- - } - if i >= 0 { - path = path[i+1:] - } - // If empty now, it had only slashes. - if path == "" { - return string(Separator) - } - return path -} - -// Dir returns all but the last element of path, typically the path's directory. -// After dropping the final element, the path is Cleaned and trailing -// slashes are removed. -// If the path is empty, Dir returns ".". -// If the path consists entirely of separators, Dir returns a single separator. -// The returned path does not end in a separator unless it is the root directory. -func Dir(path string) string { - vol := VolumeName(path) - i := len(path) - 1 - for i >= len(vol) && !os.IsPathSeparator(path[i]) { - i-- - } - dir := Clean(path[len(vol) : i+1]) - last := len(dir) - 1 - if last > 0 && os.IsPathSeparator(dir[last]) { - dir = dir[:last] - } - if dir == "" { - dir = "." - } - return vol + dir -} - -// VolumeName returns leading volume name. -// Given "C:\foo\bar" it returns "C:" under windows. -// Given "\\host\share\foo" it returns "\\host\share". -// On other platforms it returns "". -func VolumeName(path string) (v string) { - return path[:volumeNameLen(path)] -} |