7. Modify your login scripts to redefine ls to be the same as /usr/bin/ls F.
   1. Once you have done this, how can you run the ls utility without the F option?
   2. Explain what happens if you use ls in a shell script after the above alias has been defined
   3. It is usually not a good idea to redefine the names of the standard linux utilities such as ls. Why not? List all the reasons you can think of.