// The filepath package uses either forward slashes or backslashes,
// depending on the operating system. To process paths such as URLs
// that always use forward slashes regardless of the operating
-// system, see the path package.
+// system, see the [path] package.
package filepath
import (
"errors"
"io/fs"
"os"
+ "slices"
"sort"
"strings"
)
b.w++
}
+func (b *lazybuf) prepend(prefix ...byte) {
+ b.buf = slices.Insert(b.buf, 0, prefix...)
+ b.w += len(prefix)
+}
+
func (b *lazybuf) string() string {
if b.buf == nil {
return b.volAndPath[:b.volLen+b.w]
// If the result of this process is an empty string, Clean
// returns the string ".".
//
+// On Windows, Clean does not modify the volume name other than to replace
+// occurrences of "/" with `\`.
+// For example, Clean("//host/share/../x") returns `\\host\share\x`.
+//
// See also Rob Pike, “Lexical File Names in Plan 9 or
// Getting Dot-Dot Right,”
// https://9p.io/sys/doc/lexnames.html
volLen := volumeNameLen(path)
path = path[volLen:]
if path == "" {
- if volLen > 1 && originalPath[1] != ':' {
+ if volLen > 1 && os.IsPathSeparator(originalPath[0]) && os.IsPathSeparator(originalPath[1]) {
// should be UNC
return FromSlash(originalPath)
}
case os.IsPathSeparator(path[r]):
// empty path element
r++
- case path[r] == '.' && r+1 == n:
+ case path[r] == '.' && (r+1 == n || os.IsPathSeparator(path[r+1])):
// . element
r++
- case path[r] == '.' && os.IsPathSeparator(path[r+1]):
- // ./ element
- r++
-
- for r < len(path) && os.IsPathSeparator(path[r]) {
- r++
- }
- if out.w == 0 && volumeNameLen(path[r:]) > 0 {
- // When joining prefix "." and an absolute path on Windows,
- // the prefix should not be removed.
- out.append('.')
- }
case path[r] == '.' && path[r+1] == '.' && (r+2 == n || os.IsPathSeparator(path[r+2])):
// .. element: remove to last separator
r += 2
out.append('.')
}
+ postClean(&out) // avoid creating absolute paths on Windows
return FromSlash(out.string())
}
+// IsLocal reports whether path, using lexical analysis only, has all of these properties:
+//
+// - is within the subtree rooted at the directory in which path is evaluated
+// - is not an absolute path
+// - is not empty
+// - on Windows, is not a reserved name such as "NUL"
+//
+// If IsLocal(path) returns true, then
+// Join(base, path) will always produce a path contained within base and
+// Clean(path) will always produce an unrooted path with no ".." path elements.
+//
+// IsLocal is a purely lexical operation.
+// In particular, it does not account for the effect of any symbolic links
+// that may exist in the filesystem.
+func IsLocal(path string) bool {
+ return isLocal(path)
+}
+
+func unixIsLocal(path string) bool {
+ if IsAbs(path) || path == "" {
+ return false
+ }
+ hasDots := false
+ for p := path; p != ""; {
+ var part string
+ part, p, _ = strings.Cut(p, "/")
+ if part == "." || part == ".." {
+ hasDots = true
+ break
+ }
+ }
+ if hasDots {
+ path = Clean(path)
+ }
+ if path == ".." || strings.HasPrefix(path, "../") {
+ return false
+ }
+ return true
+}
+
// ToSlash returns the result of replacing each separator character
// in path with a slash ('/') character. Multiple separators are
// replaced by multiple slashes.
// as an error by any function.
var SkipDir error = fs.SkipDir
+// SkipAll is used as a return value from WalkFuncs to indicate that
+// all remaining files and directories are to be skipped. It is not returned
+// as an error by any function.
+var SkipAll error = fs.SkipAll
+
// WalkFunc is the type of the function called by Walk to visit each
// file or directory.
//
// The error result returned by the function controls how Walk continues.
// If the function returns the special value SkipDir, Walk skips the
// current directory (path if info.IsDir() is true, otherwise path's
-// parent directory). Otherwise, if the function returns a non-nil error,
-// Walk stops entirely and returns that error.
+// parent directory). If the function returns the special value SkipAll,
+// Walk skips all remaining files and directories. Otherwise, if the function
+// returns a non-nil error, Walk stops entirely and returns that error.
//
// The err argument reports an error related to path, signaling that Walk
// will not walk into that directory. The function can decide how to
return err
}
- dirs, err := readDir(path)
+ dirs, err := os.ReadDir(path)
if err != nil {
// Second call, to report ReadDir error.
err = walkDirFn(path, d, err)
if err != nil || err1 != nil {
// The caller's behavior is controlled by the return value, which is decided
// by walkFn. walkFn may ignore err and return nil.
- // If walkFn returns SkipDir, it will be handled by the caller.
+ // If walkFn returns SkipDir or SkipAll, it will be handled by the caller.
// So walk should return whatever walkFn returns.
return err1
}
// to walk that directory.
//
// WalkDir does not follow symbolic links.
+//
+// WalkDir calls fn with paths that use the separator character appropriate
+// for the operating system. This is unlike [io/fs.WalkDir], which always
+// uses slash separated paths.
func WalkDir(root string, fn fs.WalkDirFunc) error {
info, err := os.Lstat(root)
if err != nil {
err = fn(root, nil, err)
} else {
- err = walkDir(root, &statDirEntry{info}, fn)
+ err = walkDir(root, fs.FileInfoToDirEntry(info), fn)
}
- if err == SkipDir {
+ if err == SkipDir || err == SkipAll {
return nil
}
return err
}
-type statDirEntry struct {
- info fs.FileInfo
-}
-
-func (d *statDirEntry) Name() string { return d.info.Name() }
-func (d *statDirEntry) IsDir() bool { return d.info.IsDir() }
-func (d *statDirEntry) Type() fs.FileMode { return d.info.Mode().Type() }
-func (d *statDirEntry) Info() (fs.FileInfo, error) { return d.info, nil }
-
// Walk walks the file tree rooted at root, calling fn for each file or
// directory in the tree, including root.
//
} else {
err = walk(root, info, fn)
}
- if err == SkipDir {
+ if err == SkipDir || err == SkipAll {
return nil
}
return err
}
-// readDir reads the directory named by dirname and returns
-// a sorted list of directory entries.
-func readDir(dirname string) ([]fs.DirEntry, error) {
- f, err := os.Open(dirname)
- if err != nil {
- return nil, err
- }
- dirs, err := f.ReadDir(-1)
- f.Close()
- if err != nil {
- return nil, err
- }
- sort.Slice(dirs, func(i, j int) bool { return dirs[i].Name() < dirs[j].Name() })
- return dirs, nil
-}
-
// readDirNames reads the directory named by dirname and returns
// a sorted list of directory entry names.
func readDirNames(dirname string) ([]string, error) {
// Given "\\host\share\foo" it returns "\\host\share".
// On other platforms it returns "".
func VolumeName(path string) string {
- return path[:volumeNameLen(path)]
+ return FromSlash(path[:volumeNameLen(path)])
}