What happens when you give the following commands if the file named done already exists? $ cp to_do done $ mv to_do done how can you find out which utilities are available on your system for editing files? what happens when you use diff to compare two files? what is the result of giving the ""which"" utility the name of a command that resides in a directory that is not in your search path? how would you create a zipped tar file for one of your directories?