Line Sequential File support in Enterprise Cobol.

  IBM has added the support for the input and output of line sequential files to Enterprise COBOL. This allows a Cobol program running in mvs to use data stored in zOS/ Unix/HFS file (HFS – Hierarchical File System, is the is the system used to support z/OS UNIX)

Line sequential Files contain only characters(DISPLAY) data and instead of having pre- recorded boundaries, records are delimited by newline characters (x’15’).

Things to consider while writing a COBOL-Line Sequential File program 

  • Select statement

          Specify ORGANIZATION IS LINE SEQUENTAL

  • You cannot open a line sequential file in I-O mode and you cannot use REWRITE statement.
  • On READ, when a newline character is encountered, it will be replaced with the enough space to fill the record as described after FD.

         E.g. If the record length in the line sequential file is 10 and in the FD you given the record length as 200 then after READ, FD-variable will contain 10 characters from Line sequential file followed by 190 blank spaces.

  • On WRITE trailing spaces are removed and replaced by single newline character .

Things to consider while writing the JCL.

  • The ASSIGN TO clause in select statement names an external name

At run time, this external name can have a related DD statement that contains

PATH=’file_path’,FILEDATA=TEXT

Sample Program

       Identification Division.                            
       Program-Id.  unixfile.                              
       Author    .  Shibu thannikkunnath.                  
                                                           
       Environment Division.                               
       Input-Output Section.                               
       FIle-Control.                                       
           Select unixfle  assign to indd                  
           Organization is line sequential                 
           File status is unixfile-status.                 
                                                           
                                                           
           Select zfsfile  assign to zfdd                  
           File status  is zfsfile-status.                 
                                                           
       Data division.                                      
       File section.                                       
       FD  unixfle.                                        
       01  fs-unix-rec                 pic x(80).          
                                                           
       FD  zfsfile.                                        
       01  fs-zfs-rec                  pic x(80).          
                                                           
       Working-storage section.                            
       01  unixfile-status             pic x(2).           
       01  zfsfile-status              pic x(2).           
                                                           
       Eject.                                              
                                                           
       Procedure division.                                 
       A00100-MAIN.                                        
           Move spaces                 to unixfile-status. 
           Perform B00200-WRITE-FILE.                      
           perform C00300-READ-FILE.                       
           stop run.                                       
                                                           
       C00300-READ-FILE.                                   
           Open input unixfle.                                        
           Display ‘Read-Module started’.                             
           If unixfile-status not equal to 00 then                    
                   Display ‘UNIXFILE-STATUS: ‘ unixfile-status        
                   Display ‘File is not yet ready, Program terminating’
                   Move 8              to return-code                 
                   close unixfle                                      
                   stop run                                           
           else                                                       
                   Perform until unixfile-status = ‘en’               
                           read unixfle                               
                           at end move ‘en’                           
                                       to unixfile-status             
                           not at end Display fs-unix-rec             
                           end-read                                   
                   end-perform                                        
                   close unixfle                                      
           end-if.                                                    
           exit.                                                      
                                                                      
       B00200-WRITE-FILE.                                             
           Open output unixfle.                                       
           Open input zfsfile.                                        
           Display ‘Write-Module Started’.                            
           If unixfile-status not = 00 or zfsfile-status not = 00 then
                   Display ‘UNIXFILE-STATUS: ‘ unixfile-status        
                   Display ‘ZFSFILE-STATUS : ‘ zfsfile-status         
                   Display ‘File is not yet ready, Program terminating’
                   Move 8              to return-code                 
                   close unixfle                                      
                   close zfsfile                                      
                   stop run                                           
           else                                                       
                   Perform until zfsfile-status = ‘en’                
                           read zfsfile                               
                           at end move ‘en’                           
                                       to zfsfile-status              
                           not at end                                 
                               Move fs-zfs-rec                        
                                       to fs-unix-rec                 
                               Write fs-unix-rec                      
                           end-read                                   
                   end-perform                                        
                   Display ‘UNIXFILE-STATUS: ‘ unixfile-status        
                   Display ‘ZFSFILE-STATUS : ‘ zfsfile-status         
                   close unixfle                                      
                   close zfsfile                                      
           end-if.                                                    
           exit.    

Sample JCL to execute Program

***************************** Top of Data ******************************
//R0318BEJ   JOB  ‘SHIBU THANNIKKUNNATH’,REGION=0M,NOTIFY=&SYSUID     
//EXECPGM     EXEC PGM=UNIXPGM                                         
//INDD        DD   PATH=’/u/workds/helloworld.c’,                      
//        FILEDATA=TEXT
                                                
//ZFDD        DD   DSN=TSHRCI.PGMG.C(HLLOWRLD),DISP=SHR                
//STEPLIB     DD   DSN=TSHRCI.LOAD.LIB,DISP=SHR                        
//SYSIN        DD   *                                                   
/*                                                                     
//SYSOUT      DD   SYSOUT=*                                            
//                                                                   
 
**************************** Bottom of Data ****************************

Output in SPOOL

2 thoughts on “Line Sequential File support in Enterprise Cobol.

  1. Hi Shibu.
    I am copying one sequential file into various output files based on some condition. Now if an adend occurs i want to restart from the last commit point. But i want to do it using SMART/RESTART. Can u pls help me in this ?

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