CS 497C - Homework 6 - Name:_________________

    DUE: Monday, November 26 (in class)

    Please show all work on a separate sheet attached to this sheet.
    (50 points - 5 points for each problem) + (10 bonus points)

    1. How do you find out the PID of your login shell?
       Which is the process that listens on every terminal for a login
       request?
       What is the role of th swap area in the control of processes?


    2. First create a directory foo and then fill up a shell script with
       three commands shown below. What happens when you execute this script 
       and why?

       mkdir foo; cd foo; pwd


    3. If this pipeline is run from a shell script, who will be the parent 
       and grandparent of all these processes?

       nl foo | sort -nr | cut -f2-


    4. What is the difference between a process run with & and one run
       with nohup?


    5. How are the signal numbers 2 and 9 generated? What are their names 
       and how do they differ in function?


    6. Frame regular expressions to match lines containing (i) jefferies
       jeffery jeffeys (ii) hitchen hitchin hitching (iii) Heard herd
       Hird (iv) dix dicks dickson dixon (v) Mcgee mcghee magee.


    7. Use command substitution with grep to list the names of the persons 
       from emp.lst who has birthday today.
       

    8. Find out the occurrences of three consecutive and identical word
       characters (like aaa or bbb) using (i) grep and (ii) sed. 
      

    9. Locate lines that are less than 100 characters in length using
       (i) grep and (ii) sed.


   10. What is wrong with this command? How do you correct it?

       sed 's/compute/calculated/g
       s/computer/host/g' foo


   11. Write a command sequence to find out the number of occurrences of
       the word "encryption" in a file. (Note: A word may occur more than
       once in a line.)


   12. Invert the names in short list on Page 275 and place a comma after the 
       last name (i.e. last name, first name). What the result should look like
       is as below: 

       2233|harris, charles |g.m.     |sales     |12/12/52| 90000
       9876|johnson, bill   |director |production|03/12/50|130000
       5678|dylan, robert   |d.g.m.   |marketing |04/19/43| 85000
       2365|woodcock, john  |director |personnel |05/11/47|120000
       5423|wood, barry     |chairman |admin     |08/30/56|160000

       Use as few commands as possible.