Reading Variable Length File Sequentially Example

Scenario - Reading all the records sequentially from a variable length PS (Sequential) file.

Input file -

----+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
E0001EMPLOYEE1      MANAGER   0000200000         EMPLOYEE RECORD 1
E0002EMPLOYEE2      TL        0000150000         EMP REC 2
E0003EMPLOYEE3      SE        0000050000         EMP 3
E0004EMPLOYEE4      SSE       0000040000
E0005EMPLOYEE5      SE        0000040000         EMP 5

Input file properties -

Data Set Name . . . . : MATEPK.EMPLOYEE.VINPFILE                        
                                                                        
General Data                           Current Allocation               
 Management class . . : **None**        Allocated cylinders : 5         
 Storage class  . . . : **None**        Allocated extents . : 1         
  Volume serial . . . : DEVHD2                                          
  Device type . . . . : 3390                                            
 Data class . . . . . : **None**                                        
  Organization  . . . : PS             Current Utilization              
  Record format . . . : VB              Used cylinders  . . : 1         
  Record length . . . : 84              Used extents  . . . : 1         
  Block size  . . . . : 840                                             
  1st extent cylinders: 5                                               
  Secondary cylinders : 5              Dates                            
  Data set name type  :                 Creation date . . . : 2024/05/16
  SMS Compressible. . : NO              Referenced date . . : 2024/05/16
                                        Expiration date . . : ***None***

Code -

----+----1----+----2----+----3----+----4----+
       IDENTIFICATION DIVISION.
       PROGRAM-ID. SEQVFLRD.
       AUTHOR. MTH.

       ENVIRONMENT DIVISION.
       INPUT-OUTPUT SECTION.
       FILE-CONTROL.
      * EMPFILE Definition
           SELECT EMPFILE ASSIGN TO INPUT01
           ORGANIZATION IS SEQUENTIAL
           ACCESS MODE  IS SEQUENTIAL
           FILE STATUS  IS WS-FS1.

       DATA DIVISION.
       FILE SECTION.
      * EMPFILE structure definition 
       FD EMPFILE
           RECORD VARYING FROM 47 TO 80 CHARACTERS
                  DEPENDING ON EMPREC-LEN 
           RECORDING MODE  IS  V.
      * EMPFILE record structure definition
       01 EMP-RECORD80     PIC X(80).

       WORKING-STORAGE SECTION.
       01 WS-VAR.
          05 EMPREC-LEN    PIC 9(02).
          05 WS-FS1        PIC 9(02).
          05 WS-EOF-SW     PIC X(01).
             88 WS-EOF               VALUE 'Y'.
             88 WS-NOT-EOF           VALUE 'N'.

       PROCEDURE DIVISION.
      * Opening EMPFILE for reading
           OPEN INPUT EMPFILE.

      * Loop for reading all records from EMPFILE
           SET  WS-NOT-EOF      TO  TRUE.
           PERFORM UNTIL WS-EOF
                READ EMPFILE
                         AT END SET WS-EOF TO TRUE 
                     NOT AT END DISPLAY EMP-RECORD80(1:EMPREC-LEN)
                END-READ
           END-PERFORM.

      * Closing EMPFILE
           CLOSE EMPFILE.
           STOP RUN.

Run JCL -

//MATEPKF JOB MSGLEVEL=(1,1),NOTIFY=&SYSUID
//*                                                 
//STEP01  EXEC PGM=SEQVFLRD
//STEPLIB  DD  DSN=MATEPK.COBOL.LOADLIB,DISP=SHR
//INPUT01  DD  DSN=MATEPK.EMPLOYEE.VINPFILE,DISP=SHR 
//SYSOUT   DD  SYSOUT=*

Output -

E0001EMPLOYEE1      MANAGER   0000200000         EMPLOYEE RECORD 1
E0002EMPLOYEE2      TL        0000150000         EMP REC 2
E0003EMPLOYEE3      SE        0000050000         EMP 3
E0004EMPLOYEE4      SSE       0000040000
E0005EMPLOYEE5      SE        0000040000         EMP 5

Explaining Example -

In the above example:

• Variable-length sequential file (PS file) is used as an input file and trying to read all the records sequentially.
• ORGANIZATION and ACCESS MODE should be sequential.
• File should declare with RECORD VARYING...DEPENDING clause to read the file record along with length.
• File reading starts from the first record and continue till the end of the file.