Give Permission to Separate User Without Changing Pervious Permission

Question: now one new user is added to the OS. Now you should give the permission only to this new user for file /bashscript without affecting other user, group, root permission.
For this problem we can use Linux UNIX command acl
Acl-access control list
#mount –o remount /bashscript
#setfacl –m user +rwx /bashscript
You can check there permission by through getfacl command
Note: that director should mount using acl command then only it is work.
By through this method we can give full permission only to new user without changing other user permission