Finally it worked.

Here is the code:

   IDENTIFICATION DIVISION.
   PROGRAM-ID.RemoveDup2.
   ENVIRONMENT DIVISION.
   INPUT-OUTPUT SECTION.
   FILE-CONTROL.
   SELECT INPUTFILEDUP ASSIGN TO  C:CobolINPUTFILEDUP.txt 
           ORGANIZATION IS LINE SEQUENTIAL.
   SELECT OUTFILEDUP ASSIGN TO  C:CobolOUTFILEDUP.txt 
               ORGANIZATION IS LINE SEQUENTIAL.
   SELECT WorkFile ASSIGN TO "WORK.TMP".

   DATA DIVISION.

   FILE SECTION.
   FD INPUTFILEDUP.
   01 INPUTFILEDUPREC.
       88 EOFINPUTFILEDUP    VALUE HIGH-VALUES.
       02 INPUTFILEID        PIC 9(07).

   FD  OUTFILEDUP.
   01 OUTFILEDUPREC         PIC 9(07).

   SD WorkFile.
   01 WORKREC.
      02 WINPUTFILEID       PIC 9(07).

   WORKING-STORAGE SECTION.
   77 WS-VARIABLE            PIC 9(09) VALUE ZERO.
   77 REC-NOT-MATCH          PIC 9(01).
   77 CUR-VARIABLE           PIC 9(7) VALUE ZERO.

   PROCEDURE DIVISION.
   BEGIN.
       SORT WorkFile ON ASCENDING KEY WINPUTFILEID
       USING INPUTFILEDUP GIVING INPUTFILEDUP

   OPEN INPUT  INPUTFILEDUP
   OPEN OUTPUT OUTFILEDUP

       READ INPUTFILEDUP
               AT END SET EOFINPUTFILEDUP  TO TRUE
   END-READ
       PERFORM UNTIL (EOFINPUTFILEDUP)
           IF INPUTFILEID NOT EQUAL TO  WS-VARIABLE
                   MOVE  INPUTFILEID TO WS-VARIABLE
                   WRITE OUTFILEDUPREC  FROM  INPUTFILEID
                   READ  INPUTFILEDUP
                       AT END SET  EOFINPUTFILEDUP TO TRUE
       PERFORM UNTIL (EOFINPUTFILEDUP)
           ELSE
                   DISPLAY "DUPLICATE FOUND    "   INPUTFILEID

   READ INPUTFILEDUP
               AT END SET EOFINPUTFILEDUP  TO TRUE
   END-READ
   END-PERFORM

   CLOSE   INPUTFILEDUP
   CLOSE  OUTFILEDUP

   STOP RUN.

When Organization is Sequential, the record deleted is the last record read. The Delete statement is valid only when the last operation against the file is a successful Read statement. If not, the Delete returns a File Status value of 43. Because a Delete cannot return File Status values beginning with a 2 when the file is Open with Sequential Access, coding Invalid Key on such a Delete is not allowed.

When Dynamic or Random access is selected for the file, the Delete statment, like the Rewrite, becomes a little less restrictive. The record being deleted need not have bene previously read. Simply fill in the primary Key information in the record description for the fle and issue the Delete statement. If the record does not exist, a File Status of 23 is returned and an Invalid Key condition exists.

From page 274 of

Sams Teach Yourself COBOL in 24 Hours

page 274 (which I have just dusted down from off my bookshelf). So in your case you ll presumably set up your records to be sorted by INPUTFILEID, make a record as you go through of occurences of a given INPUTFILEID past its first occurence, and Delete accordingly (after you have written it to your output file).

If you will sort the file with an external sort prior to reading it in the cobol program you can remove the duplicates with the SORT keyword EQUALS. If you sort the file prior to the cobol program and do not drop duplicates then a simple IF statement and a save field will allow you to delete the dups.

Set up a INPUTFILEID-save field. Right after the read.... IF inputfileid equal inputfileid-save read again if not write... after the write move inputfileid to inputfileid-save. You will have to break up the current perform to do this.

If you do not fully understand what I am saying and will help you change the code just let me know

sort is standard for these OS close jobs to follow the DRY principle. Gears -t for separator and -u for uniques. It s C.