Workshop

The Workshop summarizes the key terms you learned and poses some questions about the topics presented in this chapter. It also provides you with a preview of what you will learn in the next hour.

Key Terms

control number A unique number that the C shell assigns to each background job for easy reference and for using with other commands, such as fg and kill.

current job The job that is currently running on the terminal and keyboard (it's the program you're actually running and working within).

errant process A process that is not performing the job you expected it to perform.

foreground job A synonym for current job.

job A synonym for process.

kill Terminate a process.

login shell The shell process that started when you logged in to the system. This is usually where you're working when you're logged in to UNIX.

process A program stopped or running within the UNIX operating system. Also known as a job.

signals Special messages that can be sent to stopped or running processes.

stop a job Stop the running program without terminating it.

wedged process A process that is stuck in memory and can't free up its resources even though it has ceased running. This is rare, but annoying.

zombie A terminated process that has not been cleaned up by the parent process.

Exercises

1:	Start a program, such as vi, and use ^z to stop it. Now terminate the process using kill.
2:	Start vi again, stop it, and put it in the background. Work on something else, and then return vi to the foreground.
3:	Use ps to check the status of processes to see what processes you have running that aren't shown on jobs. Why might ps and jobs list different processes?

Preview of the Next Hour

The next hour focuses on the many facets of printing and generating hard copy on the UNIX system. It's not as easy as you might think, so stay tuned!