Introducing UNIX and Linux

Processes and devices

Overview
Processes
      Process status
      Foreground and background
      Process control
      Signals
Environment
      Environment variables
      Global and local variables
      Executable scripts
Program control
      Job control
      Command history list
      Running a job at a specific time
      Running programs periodically
      Big programs
      Timing a program
      Running programs in order
Quotes and escapes
Devices
Backquotes
Summary
Exercises

Overview

In this chapter you will learn about

processes, jobs and the execution environment; and
UNIX handling of input and output devices.

The basic program unit apparent to a programmer working in a UNIX environment is the 'process'. An understanding of how processes are handled is fundamental to the effective use of UNIX.