Linux Shell Scripting with Bash

Chapter 10. Job Control and Signals

Although I grew up on a grape farm, I didn't spend a lot of time out in the fields. I suppose that was my father's way of not biasing me towards a life of sweat and sunburns. Somehow one farming skill that I never mastered was the use of hand signals. It seemed like those who had spent years outdoors were used to gesticulating over distances and noise, able to understand the most incomprehensible motioning. Not so for me.

One summer my father was trying to place a heavy piece of equipment into the back of a pickup truck using his tractor. He had me stationed at the base of the truck to line up the equipment and tell him when to start lowering. When everything looked in position, I gave him the signal. Unfortunately, ...