Chapter 4. Building Blocks

When you're young, you learn numbers, and then later you learn how to combine and work with those numbers using symbols such as +, , x, and =. So far in this book, you've learned several commands, but each one has been run one at a time. Commands can actually be combined in more complex and more interesting ways, however, using various symbols such as |, >, >>, and <. This chapter takes a look at those building blocks that enable you to do some useful things with the commands you've learned and the commands you'll be examining in greater detail in subsequent chapters.