| After the subroutine has been executed, the accumulator contains the answer. |
| It can find the bug if you ask your subroutine for a scalar, but you mistakenly have the subroutine return an array. |
| A subroutine is a part of a program that can be re-used, just like movable type. |
| A unit test would directly call the subroutine I want to test, and it would rely as little as possible on other subroutines in the program. |
| Right after the subroutine we use it to create a format string to unpack the output from fdisk. |
| To be safe you can use the keyword before any subroutine call even if the subroutine is already defined. |
