The Linux Command Line, 2nd Edition

26TOP-DOWN DESIGN

As programs get larger and more complex, they become more difficult to design, code, and maintain. As with any large project, it is often a good idea to break large, complex tasks into a series of small, simple tasks. Let’s imagine we are trying to describe a common, everyday task, going to the market to buy food, to a person from Mars. We might describe the overall process as the following series of steps:

1. Get in car.
2. Drive to market.
3. Park car.
4. Enter market.
5. Purchase food.
6. Return to car.
7. Drive home.
8. Park car.
9. Enter house.

However, a person from Mars is likely to need more detail. We could further break down the subtask “Park ...