Write a script that takes exactly one argument, a directory name. If the number of arguments is more or less than one, print a usage message. If the argument is not a directory, print another message. For the given directory, print the three biggest files and the three files that were most recently modified. Display your script on the terminal using the cat command. Test your script using arguments that cover two user error cases mentioned above. Then run your script with /usr/sbin as the input.