package alias import (	"context"	"errors"	"strings" 	"github.com/rclone/rclone/fs"	"github.com/rclone/rclone/fs/cache"	"github.com/rclone/rclone/fs/config/configmap"	"github.com/rclone/rclone/fs/config/configstruct"	"github.com/rclone/rclone/fs/fspath") // Register with Fsfunc init() {	fsi := &fs.RegInfo{		Name:        "alias",		Description: "Alias for an existing remote",		NewFs:       NewFs,		Options: []fs.Option{{			Name:     "remote",			Help:     "Remote or path to alias.\nCan be \"myremote:path/to/dir\", \"myremote:bucket\", \"myremote:\" or \"/local/path\".",			Required: true,		}},	}	fs.Register(fsi)} // Options defines the configuration for this backendtype Options struct {	Remote string `config:"remote"`} // NewFs constructs an Fs from the path.//// The returned Fs is the actual Fs, referenced by remote in the configfunc NewFs(ctx context.Context, name, root string, m configmap.Mapper) (fs.Fs, error) {	// Parse config into Options struct	opt := new(Options)	err := configstruct.Set(m, opt)	if err != nil {		return nil, err	}	if opt.Remote == "" {		return nil, errors.New("alias can't point to an empty remote - check the value of the remote setting")	}	if strings.HasPrefix(opt.Remote, name+":") {		return nil, errors.New("can't point alias remote at itself - check the value of the remote setting")	}	return cache.Get(ctx, fspath.JoinRootPath(opt.Remote, root))}