Cobol errors, cannot seem to figure it out

Question

I'm encountering compilation errors in my COBOL program, where the compiler is indicating that file names like 'INPUT-FILE' and 'OUTPUT-FILE' are not defined. Despite defining these files in the FILE SECTION of the program, the compiler seems unable to recognize them. I've tried adjusting the I/O setup, but the errors persist. Can anyone help me understand why these errors are occurring and how to resolve them? Below is a snippet of my COBOL code for reference.

abc.cob:6: error: 'INPUT-FILE' is not defined
abc.cob:6: error: 'INPUT-FILE' is not a file name
abc.cob:11: error: 'OUTPUT-FILE' is not defined
abc.cob:11: error: 'OUTPUT-FILE' is not a file name
abc.cob:44: error: 'INPUT-FILENAME' is not defined
abc.cob:45: error: 'INPUT-FILENAME' is not a file name
abc.cob:46: error: 'OUTPUT-FILE' is not a file name
abc.cob: in paragraph 'PROC-BODY':
abc.cob:62: error: 'INPUT-FILE' is not a file name
abc.cob: in paragraph 'INPUT-LOOP':
abc.cob:87: error: 'INPUT-FILE' is not a file name
abc.cob: in paragraph 'END-OF-JOB':
abc.cob:94: error: 'INPUT-FILE' is not a file name
abc.cob:94: error: 'OUTPUT-FILE' is not a file name

I've tried adjusing I/O setup, and nothing.

   IDENTIFICATION DIVISION.
   PROGRAM-ID. Calculate-Mean-StdDev.

   DATA DIVISION.
   FILE SECTION.
   FD INPUT-FILE.
   01 INPUT-VALUE-RECORD.
      02 IN-X        PIC S9(6)V9(2).
      02 FILLER      PIC X(72).

   FD OUTPUT-FILE.
   01 OUTPUT-RECORD.
      02 OUTPUT-LINE PIC X(80).

   WORKING-STORAGE SECTION.
   77 SUM-OF-X-SQR   PIC 9(14)V9(2).
   77 SUM-OF-X       PIC S9(10)V9(2).
   77 N              PIC S9(4).
   77 MEAN           PIC S9(6)V9(2).
   77 I              PIC S9(4).
   01 ARRAY-AREA.
      02 X           PIC S9(6)V9(2) OCCURS 1000 TIMES.
   01 OUTPUT-TITLE-LINE.
      02 FILLER      PIC X(28) VALUE
                    " MEAN AND STANDARD DEVIATION".
   01 OUTPUT-UNDERLINE.
      02 FILLER      PIC X(28) VALUE
                    "----------------------------".
   01 OUTPUT-COL-HEADS.
      02 FILLER      PIC X(10) VALUE SPACES.
      02 FILLER      PIC X(11) VALUE "DATA VALUES".
   01 OUTPUT-DATA-LINE.
      02 FILLER      PIC X(10) VALUE SPACES.
      02 OUT-X       PIC -(6)9.9(2).
   01 OUTPUT-RESULTS-LINE-1.
      02 FILLER      PIC X(9) VALUE " MEAN=   ".
      02 OUT-MEAN    PIC -(6)9.9(2).
   01 OUTPUT-RESULTS-LINE-2.
      02 FILLER      PIC X(9) VALUE " STD DEV=".
      02 STD-DEVIATION    PIC -(6)9.9(2).

   PROCEDURE DIVISION.
       DISPLAY "Enter the input file name: "
       ACCEPT INPUT-FILENAME
       OPEN INPUT INPUT-FILENAME
            OUTPUT OUTPUT-FILE.
       MOVE ZERO TO IN-X.
       PERFORM PROC-BODY
          UNTIL IN-X IS NOT LESS THAN 999999.99.
       PERFORM END-OF-JOB.

   PROC-BODY.
       WRITE OUTPUT-RECORD FROM OUTPUT-TITLE-LINE
          AFTER ADVANCING 0 LINES.
       WRITE OUTPUT-RECORD FROM OUTPUT-UNDERLINE
          AFTER ADVANCING 1 LINE.
       WRITE OUTPUT-RECORD FROM OUTPUT-COL-HEADS
          AFTER ADVANCING 1 LINE.
       WRITE OUTPUT-RECORD FROM OUTPUT-UNDERLINE
          AFTER ADVANCING 1 LINE.
       MOVE ZERO TO SUM-OF-X.
       READ INPUT-FILE INTO INPUT-VALUE-RECORD
          AT END PERFORM END-OF-JOB.
       PERFORM INPUT-LOOP
          VARYING N FROM 1 BY 1
          UNTIL N IS GREATER THAN 1000 OR IN-X IS NOT LESS THAN 999999.98.
       SUBTRACT 1 FROM N.
       DIVIDE N INTO SUM-OF-X GIVING MEAN ROUNDED.
       MOVE ZERO TO SUM-OF-X-SQR.
       PERFORM SUM-LOOP
          VARYING I FROM 1 BY 1
          UNTIL I IS GREATER THAN N.
       COMPUTE STD-DEVIATION ROUNDED = (SUM-OF-X-SQR / N) ** 0.5.
       WRITE OUTPUT-RECORD FROM OUTPUT-UNDERLINE
          AFTER ADVANCING 1 LINE.
       MOVE MEAN TO OUT-MEAN.
       WRITE OUTPUT-RECORD FROM OUTPUT-RESULTS-LINE-1
          AFTER ADVANCING 1 LINE.
       WRITE OUTPUT-RECORD FROM OUTPUT-RESULTS-LINE-2
          AFTER ADVANCING 1 LINE.

   INPUT-LOOP.
       MOVE IN-X TO X(N), OUT-X.
       WRITE OUTPUT-RECORD FROM OUTPUT-DATA-LINE
          AFTER ADVANCING 1 LINE.
       ADD X(N) TO SUM-OF-X.
       READ INPUT-FILE INTO INPUT-VALUE-RECORD
          AT END PERFORM END-OF-JOB.

   SUM-LOOP.
       COMPUTE SUM-OF-X-SQR = SUM-OF-X-SQR + (X(I) - MEAN) ** 2.

   END-OF-JOB.
       CLOSE INPUT-FILE, OUTPUT-FILE.
       STOP RUN.

I 've tried adjusting the I/O setup, but the errors persist. Can anyone help me understand why these errors are occurring and how to resolve them? Below is a snippet of my COBOL code for reference.

Answer 1

Between your Identification Division and your Data Division you need an Environment Division, in which you need an Input-Output Section, in which you need a File-Control paragraph, in which you need to code Select statements for your files.

Environment Division.
Input-Output Section.
File-Control.
    Select INPUT-FILE  Assign To INPUT-FILE-NAME.
    Select OUTPUT-FILE Assign To '~/output-file'.

The above is just freehand, not tested, presuming GNU COBOL as you are using their extension where the target of the Assign To can be a variable.

You will need to change your code so that the INPUT-FILE variable into which the ACCEPT statement places the file name and the file name in the SELECT an FD statements are different, above I did that with INPUT-FILE-NAME.

There may be other problems in your code, I didn't do an exhaustive analysis.