We will be using lab1b.cob
to learn how to run the debugger. In the terminal window click the top right
corner button, the one that looks like a box (not the dot) to maximize your
terminal window. You can toggle this button to enlarge and reduce your terminal
window. You MUST maximize your terminal window to run the debugger
effectively (actually, you need to maximize the terminal window before the runcbl command). Once you have maximized your terminal
window, type the following commands to first compile the program with debugging
information and then to run the lab in the debugger:
ccbl -Zd lab1b.cob
runcbl -d lab1b
You will see a menu at the top of the window (press F10 to activate the menu at the top of the screen, if necessary), a source code area and a command area at the bottom. A list of debugger commands can be accessed by typing help in the command area (use the up and down arrow keys to scroll and press enter to exit the help screen). Typing q! on the command line will exit the debugger at any time. Notice that a black box exists to the left of the PERFORM statement in paragraph 000-CALCULATE-FUTURE-VALUES. This is the cursor for the debugger.
A few commands that you will use
frequently are given below (do not try them yet!)
Create a file called lab3ques.txt
to hold the answers to the questions given below.
Compile the program appropriately
and start the debugger
Single step 4
times.
Single step 1 more
time.
Single step 3 more
times.
You will need to single step twice
to enter each set of input data. When asked, enter 10000 for the investment
amount, 10 for the number of years and 1000 for the yearly interest rate
(remember, the program does not accept edited input.
These inputs represent the values 10000, 10 and 10.00). Once you have entered
the data the debugger cursor should be to the left of the statement MOVE
INVESTMENT-AMOUNT TO FUTURE-VALUE.
Single step two
more times.
Set a breakpoint at paragraph
120-CALCULATE-NEXT-FV (A B should appear to the left of this paragraph
name). Enter g twice.
Enter g twice more.
8. What is the current value of
FUTURE-VALUE?
9. How many more times do you have to
enter g before something different happens?
10.
Why
did you get there?
Enter 1 to perform another
calculation and enter the same input information.
11.
What
debugger command will clear all breakpoints? Use help.
Clear all breakpoints. Type g. When asked to end the program or perform another
calculation, end the program.
Convert lab1b to use file I/O. So,
instead of inputting and outputting data to and from the terminal, you will
input and output the data using files. Name this COBOL program lab3b.cob, the input file will be named lab3bin.dat
and the output file lab3bout.dat. Your input data will include
investment amount, number of years and yearly interest rate. Do not assume that
you know how many sets of input you have. When you output the information be
sure to do so nicely, similar to the following:
Your investment amount was $999,999,999.99The number of years was 99The yearly interest rate was 99.99%The future value of your investment will be $999,999,999.99
You will need to create the input file yourself (just use an editor) that matches the file definition you have in the program. This must contain at least 5 records. This file must be submitted with your lab.
You can instead use report style output if you wish. Be sure to output the input values along with the results.
12.
What
happens if you move data to the FD variable then try to WRITE the record?
13.
What
happens if you move the output data to the record variable then try to WRITE
using the FD variable?
14.
If
you have already compiled the program but decide to change the input data in
the file, do you have to recompile the program to run with the new data?
Write a COBOL program (name it lab3c.cob)
to accomplish the following: St. Nowhere Hospital would like to determine how
much money in unpaid bills is still owed by people who have received patient
care at their facility. Once they have a listing of all of the patients and the
amount of each bill the hospital would also like to see the total amount still
owed and the average amount owed per patient.
The input file ~sgomori/students/cis314/lab3cin.dat
has been created for you and has the following specifications for each billing
recipient:
Add to your select statement for the
input file the following clause:
ORGANIZATION IS LINE SEQUENTIAL
and make sure the record description
has exactly 72 bytes.
Output the data to lab3cout.dat.
You will need to keep track of the number of lines you have printed in order to
advance to the next page at the appropriate time. Limit yourself to 65 lines
per page. Underline the column headings by ADVANCING 0 LINES. You will need to
use edited output for the dates and numeric data. The report format follows.
Vertical formatting (line spacing) must match exactly. Horizontal formatting
(columns) is up to you, but it must look nice (column headings centered over
data, etc.)
Sample output: