Function recursiveSymlinks

xunix/gpu.go:161–199

recursiveSymlinks returns all of the paths in the chain of symlinks starting at `path`. If `path` isn't a symlink, only `path` is returned. If at any point the symlink chain goes outside of `mountpoint` then nil is returned. Despite its name it's interestingly enough not implemented recursively.

(afs FS, mountpoint string, path string)

// point the symlink chain goes outside of `mountpoint` then nil is returned.
// Despite its name it's interestingly enough not implemented recursively.
func recursiveSymlinks(afs FS, mountpoint string, path string) ([]string, error) {
	if !strings.HasSuffix(mountpoint, "/") {
		mountpoint += "/"
	}

	paths := []string{}
	for {
		if !strings.HasPrefix(path, mountpoint) {
			return nil, nil
		}

		stat, err := afs.LStat(path)
		if err != nil {
			return nil, xerrors.Errorf("lstat %q: %w", path, err)
		}

		paths = append(paths, path)
		if stat.Mode()&os.ModeSymlink == 0 {
			break
		}

		newPath, err := afs.Readlink(path)
		if err != nil {
			return nil, xerrors.Errorf("readlink %q: %w", path, err)
		}
		if newPath == "" {
			break
		}

		if filepath.IsAbs(newPath) {
			path = newPath
		} else {
			dir := filepath.Dir(path)
			path = filepath.Join(dir, newPath)
		}
	}

	return paths, nil
}

// SameDirSymlinks returns all links in the same directory as `target` that
// point to target, either indirectly or directly. Only symlinks in the same