How will u list the contents of parent directory from the current directory? What are the default system wide permissions for a file and directory? What is the default umask value?A user is not able to change the permission , What can it happen? What's the difference between ls -F , ls -p? If a file permission are 000, can the superuser still read and write to that file.? What's the command to remove the files without write permission? How will u make sure that no one can see the files which u had created? How will u change the permissions of a directory recursively? Any response will be greatly appreciated?