CSc265 -- Exercise 3

DUE: midnight, Tuesday 5 November 1996


Overview

The purpose of this exercise is to provide experience with using dbx. You are provided with the source code of the compress and uncompress programs. (These are the same compress and uncompress programs that are commonly used in Unix and other systems to reduce file sizes -- typically by 50% to 60% depending on the nature of the file.) You must compile the program following the instructions below. Then you must use dbx to run the program and answer some questions about the program's operation.

Preparing for the Assignment

The directory /home/csc265/Exercises/Ex3 contains three files, named README, testdata and compress.c. You should copy all three files into your own directory. You should execute the two commands below:
	% cc -g -o compress compress.c
	% ln compress uncompress  
There will be a couple of warning messages produced by the compiler; you can safely ignore these messages. The commands create two additional entries in your directory named compress and uncompress. These two entries both refer to the same executable file. (One of the first actions of the program is to test what command name was used to invoke it and that selects between the compression and decompression functions.)

Notes:



Submitting Your Solutions

The README file is in the form of a questionnaire. Use vi or your favourite text editor to add your answers to that file. Then e-mail the updated README file to the csc265 account. The following command will perform that task:
	% mail -s 'Exercise 3 submission' csc265@gulf < README


Grading Criteria

You will receive ten points for each question answered correctly. Submit the assignment only once. Only the first submission will be graded.