Extract records by first letter of name - cobol

Question

I am trying to make the program below to pull out records that have customer names beginning with letter the "M" and write the records to a temporary file. The program runs but it won't write records to the output file. I debugged the code, and it seems like the code line "WRITE MAST2-RECORD" never runs. It skips this line of code.
ENVIRONMENT DIVISION.
INPUT-OUTPUT SECTION.
FILE-CONTROL.
SELECT MAST-FILE ASSIGN TO 'G:\CPSC315-COBOL\COBOLAssignments\P15-1\OVERDUE.IND.TXT'
ORGANIZATION IS INDEXED
ACCESS IS RANDOM
RECORD KEY IS M-ACCT-NUM.
SELECT MAST2-FILE ASSIGN TO 'G:\CPSC315-COBOL\COBOLAssignments\P15-1\OVERDUE2.IND.TXT'
ORGANIZATION IS LINE SEQUENTIAL.
DATA DIVISION.
FILE SECTION.
FD MAST-FILE
LABEL RECORDS ARE STANDARD.
01 MAST-RECORD.
05 M-ACCT-NUM PIC X(4).
05 M-CUSTOMER-NAME PIC X(15).
05 M-DAYS-OVERDUE PIC 99.
05 M-BALANCE-DUE PIC 999V99.
FD MAST2-FILE
LABEL RECORDS ARE STANDARD.
01 MAST2-RECORD PIC X(50).
WORKING-STORAGE SECTION.
01 COUNTER PIC 9.
01 PROGRAM-DATA-ITEMS.
05 WRITE-OK PIC X VALUE 'Y'.
PROCEDURE DIVISION.
10-MAINLINE.
OPEN OUTPUT MAST-FILE
OUTPUT MAST2-FILE
PERFORM 20-LOAD-MAST-FILE
CLOSE MAST-FILE
MAST2-FILE
STOP RUN.
20-LOAD-MAST-FILE.
PERFORM 30-INPUT-INDEX
PERFORM UNTIL M-ACCT-NUM = 0 OR WRITE-OK = 'N'
PERFORM 40-WRITE-FILE
PERFORM 50-FIND-CUSTOMER-START-WITH-M
PERFORM 30-INPUT-INDEX
END-PERFORM.
30-INPUT-INDEX.
DISPLAY 'ENTER ACCOUNT NUMBER (0 TO QUIT): ' WITH NO ADVANCING
ACCEPT M-ACCT-NUM.
40-WRITE-FILE.
DISPLAY ' ENTER CUSTOMER NAME: ' WITH NO ADVANCING
ACCEPT M-CUSTOMER-NAME
DISPLAY ' ENTER DAYS OVERDUE: ' WITH NO ADVANCING
ACCEPT M-DAYS-OVERDUE
DISPLAY ' ENTER BALANCE DUE: ' WITH NO ADVANCING
ACCEPT M-BALANCE-DUE
WRITE MAST-RECORD
INVALID KEY
MOVE 'N' TO WRITE-OK
DISPLAY 'ERROR ' MAST-RECORD
END-WRITE.
50-FIND-CUSTOMER-START-WITH-M.
MOVE 0 TO COUNTER
INSPECT MAST-RECORD TALLYING COUNTER FOR ALL ' M '
IF COUNTER > 0
WRITE MAST2-RECORD
END-IF.
end program Program1.

Answer 1

You are looking for blank-M-blank, across the entire record.
What you say you want to do is fine customer-names which begin with M.
05 M-CUSTOMER-NAME.
10 M-CUSTOMER-NAME-FIST-CHARACTER PIC X.
88 M-CUSTOMER-NAME-START-M VALUE "M".
If you use that definition in place of what you have, and use the 88 in the test for your write, you should get what you want.
Eg replace:
50-FIND-CUSTOMER-START-WITH-M.
MOVE 0 TO COUNTER
INSPECT MAST-RECORD TALLYING COUNTER FOR ALL ' M '
IF COUNTER > 0
WRITE MAST2-RECORD
END-IF.
By:
50-FIND-CUSTOMER-START-WITH-M.
IF M-CUSTOMER-NAME-START-M
WRITE MAST2-RECORD
END-IF
.
Simpler, easier to understand, so easier to maintain.
You should consider the possible "validity" of your names. In a good system, there will be no leading blanks. In a poor system there may be.
To deal with that, test the first byte of the customer-name for being space as well, if so, test the customer-name for entirely space. If not entirely space, loop until you find the first non-blank. Test that first non-blank for M. So in this case you have two tests.
You can assess the quality of your data separately by copying and cutting-down this program and reporting/outputting where the first byte of the customer-name is blank.
Once you know that, you go to the analyst (tutor) and ask if you need to deal with possible leading blanks. If you don't, keep the test for blank in your actual program, and crash in that case :-)