Cobol 1:n match sample

Here is a sample COBOL program that performs a 1:n match using a sequential search algorithm.

IDENTIFICATION DIVISION.
PROGRAM-ID. MATCH-EXAMPLE.

DATA DIVISION.
WORKING-STORAGE SECTION.
01 CUSTOMER-TABLE.
   05 CUSTOMER-ENTRY OCCURS 5 TIMES.
      10 CUSTOMER-NAME PIC X(20).
      10 CUSTOMER-AGE PIC 99.
      10 CUSTOMER-ZIP PIC X(5).
01 SEARCH-NAME PIC X(20).
01 MATCH-FOUND PIC X VALUE 'N'.
01 I PIC 99.

PROCEDURE DIVISION.
BEGIN.
   DISPLAY "Enter name to search for: "
   ACCEPT SEARCH-NAME
   PERFORM SEARCH-CUSTOMER-TABLE
   IF MATCH-FOUND = 'Y'
      DISPLAY "Match found for ", SEARCH-NAME
   ELSE
      DISPLAY "No match found for ", SEARCH-NAME
   END-IF
   STOP RUN.

SEARCH-CUSTOMER-TABLE.
   PERFORM VARYING I FROM 1 BY 1 UNTIL I > 5 OR MATCH-FOUND = 'Y'
      IF CUSTOMER-NAME(I) = SEARCH-NAME
         SET MATCH-FOUND TO 'Y'
      END-IF
   END-PERFORM.

In this example, we have a table of customer information with 5 entries. We prompt the user to enter a name to search for, and then perform a sequential search through the customer table to find a match. If a match is found, we set the MATCH-FOUND flag to 'Y' and exit the loop. If no match is found, we continue iterating through the table until we reach the end or find a match.

Note that this is a very simple example and is not optimized for performance or scalability. In a real-world scenario with a large dataset, a more efficient search algorithm such as binary search or hash table lookup would likely be used.