A short exercise in relative  files  using  pointers  to  implement  a
hierarchial structure and hashing for direct access.


The relative file CUSTOMER.REL contains information  about  
customers,

and is organized as follows:

     FD CUSTOMER-FILE.
     01 CUSTOMER-REC.
        02      CNO PIC XX.
        02      CNAME PIC X(10).
        02      CITY PIC X(15).
        02      NEXT-CUST       PIC 99.
        02      FIRST-ORDER     PIC 99.

NEXT-CUST  is  the  record  number  of  the  next   customer   record.
FIRST-ORDER  is  the  record  number of the first order record for 
the customer (not all customers have orders pending).  The first 
record is a  list header containing the record number of the first 
record in the list.  The last entry in the list points back to the list 
header.


The file ORDER.REL contains information about  orders  that  
customers have  made.   This  order  file  contains only basic 
information:  the line-by-line details of an order is contained in 
LINE.REL.  These last two files are described as follows:

     FD ORDER-FILE.
     01 ORDER-REC.
        02      ORDER-KEY.
                04      CNO PIC XX.
                04      ORDER-NO PIC X(3).
        02      DATE-OF-ORDER.
                04      MM PIC XX.
                04      DD PIC XX.
                04      YY PIC XX.
        02      NEXT-ORDER-SAME-CUSTOMER        PIC 99.
        02      NEXT-ORDER                      PIC 99.
        02      FIRST-ORDER-LINE                PIC 99.

NEXT-ORDER-SAME-CUSTOMER is the record number of the  next  
order  for the  current customer (0 if there are no more orders).  
NEXT-ORDER can be ignored for this exercise.  FIRST-ORDER-LINE is 
the  record  number of the first line record for this order.

     FD LINE-FILE.
     01 LINE-REC.
        02      LINE-KEY.
                04      ORDER-NO PIC XXX.
                04      LINE-NO PIC XX.
        02      CATALOG-NO PIC X(5).
        02      QTY PIC 99.
        02      NEXT-LINE-SAME-ORDER    PIC 99.


NEXT-LINE-SAME-ORDER is the record number of the next line in the 
same order (or zero if there are no more line records).


The file CATALOG.REL contains information about items for sale and  
is organized as follows:

     FD CATALOG-FILE.
     01 CATALOG-REC.
        02      CATALOG-NO PIC X(5).
        02      DESCRIPTION PIC X(20).
        02      UNIT-COST PIC 999V99.

     CATALOG.REL is hashed on CATALOG-NO using a divisor of  7  and  
a
     bucked size of 10.


     All files are in [MATTHEWS.CS255]

	Write a program which will list each customer;  for each
	customer list the orders the customer has (if any); for 
	each order, list the line items for the order.  No formatting
	is necessary:  for full credit on this exercise (15 pts.)	
	it is sufficient simply to print out the record.

	For 5 pts. extra credit:  Format the output a bit.

	For 10 pts. extra credit:  Finish the program by adding
	catalog information (hash into the catalog file) and
	retrieve the item description and cost.  Product subtotals
	and totals in your output listing.


     Call this program LIST01.COB.  Output should be directed  to  the
     file OUTPUT.LIS.

Due:  Day of final exam (Monday, Dec. 15)