copyurl: add --auto-filename flag for using file name from url in destination path (#3451)

cmd/copyurl/copyurl.go

@@ -4,12 +4,18 @@ import (
 	"context"
 
 	"github.com/rclone/rclone/cmd"
+	"github.com/rclone/rclone/fs"
 	"github.com/rclone/rclone/fs/operations"
 	"github.com/spf13/cobra"
 )
 
+var (
+	autoFilename = false
+)
+
 func init() {
 	cmd.Root.AddCommand(commandDefintion)
+	commandDefintion.Flags().BoolVarP(&autoFilename, "auto-filename", "a", autoFilename, "Get the file name from the url and use it for destination file path")
 }
 
 var commandDefintion = &cobra.Command{
@@ -18,13 +24,22 @@ var commandDefintion = &cobra.Command{
 	Long: `
 Download urls content and copy it to destination 
 without saving it in tmp storage.
+
+Setting --auto-filename flag will cause retrieving file name from url and using it in destination path. 
 `,
 	Run: func(command *cobra.Command, args []string) {
 		cmd.CheckArgs(2, 2, command, args)
-		fsdst, dstFileName := cmd.NewFsDstFile(args[1:])
+
+		var dstFileName string
+		var fsdst fs.Fs
+		if autoFilename {
+			fsdst = cmd.NewFsDir(args[1:])
+		} else {
+			fsdst, dstFileName = cmd.NewFsDstFile(args[1:])
+		}
 
 		cmd.Run(true, true, command, func() error {
-			_, err := operations.CopyURL(context.Background(), fsdst, dstFileName, args[0])
+			_, err := operations.CopyURL(context.Background(), fsdst, dstFileName, args[0], autoFilename)
 			return err
 		})
 	},