It is recommended to use the sequential file if the simple file read and write is required and there are the less frequent search of a random and dynamic accessing of record is required. The Syntax of Sequential file. SELECT LOGICAL-FL ASSIGNED TO PHYSICAL FL ORGANIZATION IS SEQUENTIAL. This we code in the FILE-CONTROL under INPUT-OUTPUT SECTION which is defined under ENVIRONMENT DIVISION.
This name of the file is used only inside the cobol program) used in a file's FD entry is connected to an external file (Actual physical file on disk or tape) by means of the SELECT and ASSIGN clause. The SELECT and ASSIGN clause is an entry in the FILE-CONTROL paragraph in the INPUT-OUTPUT SECTION in the ENVIRONMENT DIVISION. Suppose we have a file with below type of data in our input file.
To connect the VSAM data set to your COBOL program for processing. WRITE To add records to a file or load a file. START To establish the current location in the cluster for a READ NEXT statement. START does not retrieve a record; it only sets the current record pointer. READ and READ NEXT To retrieve records from a file. REWRITE To update records. DELETE To logically remove records from.To read a record from a file. With sequential processing, a program reads one record after another in the same order in which the records were entered when the file was created. WRITE To create a record in a file. A program writes new records to the end of the file. CLOSE To release the connection between a file and the program. related tasks Defining line-sequential files and records in COBOL.Code for PROGRAM FOR READ DATA FROM INPUT-FILE AND MOVE INTO OUTPUT-FILE in Cobol identification division. program-id. test. environment division. configuration section. input-output section. file-control. select in-file assign to disk organization is line sequential. select out-file assign to disk organization is line sequential. data division. file section. fd in-file label records are.
The WRITE statement can only be executed for a sequential file opened in OUTPUT or EXTEND mode. When the punch function is used, the next I-O operation after the READ statement must be a WRITE statement for the punch function file. If you want to punch additional data into some of the cards and not into others, a dummy WRITE statement must be executed for the null cards, first filling the.Read More
File opened with Extend Mode appends the writing records at the end of the file. In COBOL program there is no much difference between these two types. If you are accessing ESDS VSAM file, then in COBOL program should coded like this. SELECT FILE ASSIGN TO AS-DDNAME. Actually DD name matches with JCL DD Name. But in COBOL Program DDNAMEs should be prefixed with AS- (In case of VSAM ESDS file.Read More
Things to consider while writing a COBOL-Line Sequential File program. 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.Read More
This program is designed to read the employee file, keep a running total of all salaries, and print out a report of employees and the total salary amount. My test file only has eight records in it, but that will be easy for us to double check when we run the program to make sure every record gets read. To read the file, we must assign the file in the environment division. The environment.Read More
This program will read a record sequential file and write to a VSAM Keyed-Sequential-Data-Set. The encoding schema (i.e. ASCII or EBCDIC) and record format (i.e. 512-byte, fixed-length records with packed and binary data fields) will be the same for both the input and output file. Note: Since this conversion task is only doing a file-format conversion and the record content is not processed.Read More
The COBOL source code (CBLVLRC2.cbl) for the program that converts a record sequential file with 80 bytes fixed length records to a mainframe (or ZOS) formatted sequential file with variable length records with the size varying from 4 to 32,760 bytes is available in a separate document.Read More
COBOL programs process the logical file the way file is logically defined in the program. Record structure. COBOL mainly process structured data. That is data organized as a record. A COBOL record is defined as a group variable with 01 level. Entire contents of group are part of a record. When a read statement is performed entire record (01.Read More
When you write COBOL Programs, that read data records from Files,. When you do a READ INPUT-FILE, the input record QUASAR 1000 20-10-06 is read from the file, and received and stored in EMPLOYEE-INPUT-RECORD Storage Area. Similarly, the Output Storage Area is the place in the COBOL Program, from where the data departs and is output to the File, here for the OUTPUT-FILE it is EMPLOYEE-OUTPUT.Read More
COBOL - File Access Mode. Every file organization (In our previous section, we discussed many file organizations) has different modes of access. The access mode is used to define the accessing way of the file based on the requirements in the program. In short, we can say, access mode defines how the data is required to read and write from the file.Read More
A program is required to produce a summary sales report from an unsorted sequential file containing the details of sales of essential and base oils to Aromamora customers. Read the program specification first.Read More