Chapter 5. Flow Control

If you are a programmer, you may have read the last chapter-with its claim at the outset that the Korn shell has an advanced set of programming capabilities—and wondered where many features from conventional languages are. Perhaps the most glaringly obvious "hole" in our coverage thus far concerns flow control constructs like if, for, while, and so on.

Flow control gives a programmer the power to specify that only certain portions of a program run, or that certain portions run repeatedly, according to conditions such as the values of variables, whether or not commands execute properly, and others. We call this the ability to control the flow of a program's execution.