ooad stuff

Encapsulation:

• Allows you to group objects into logical parts
• YOu can change one part without having to change the entire object
• You shoould encapsulate parts of objects( that may change )away from parts which change

Three ways in which well defined software is easier to use than sw wiht duplicate code:
1) modification is easy
2)cleaner?
 

shell

Shell:
You interact with unix using a special program called Shell. IT passes to commands to the Unix operating system.
It comes in different flavours: bash, Bourne shell(sh), C Shell(csh) etc.
Each shell uses a particular character (or string of characters) to prompt the user for commands; not surprisingly, this is known as a shell prompt. Exercises in this tutorial show the default shell prompt for csh, the "%" character.