CTS 1106 (Intro to Unix/Linux) Homework Assignment #7

 

Due: by the start of class on the date shown on the syllabus

Description:

Answer the following questions as briefly (but completely) as possible  (Some of these questions are based on the on-line crontab and at resources, and communication utility man pages.)

  1. If two users execute the same program at the same time, are the memory requirements doubled?
  2. How do you find out the complete command line of a running process by a user named romeo?
  3. How can you kill the last background job without knowing its PID?  Will that command work in all shells?
  4. What is the difference between a process run with & and one run with nohup?
  5. Name some commands (at least two) that don't require a separate process.
  6. What does the exit command do?
  7. Interpret the following crontab entries (i.e., when will they run and what will they do):
    1. * * * * * foo.sh
    2. 30 21 * * * find /tmp /usr/tmp -atime +30 -exec rm -f {} \;
  8. The administrator has decided that most users should be allowed to use at and cron.  What is the way to enable this, that requires the minimum effort?
  9. If talk displays a message “Your party is refusing messages”, what is the most likely cause?

Optional GUI Questions:

  1. What is the difference between removing a file with rm at the command line, and dragging it to the “Trash Can” from the GUI?
  2. What are the elements that comprise an X display?
  3. How is the DISPLAY variable more convenient to use than the -display option?
  4. What happens if there is no window manager running on your system?  Can you still work?
  5. How can you make one xterm window show a different name in its title bar?

To be turned in:

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