COBOL Tutorial Class 2 : Constants and Variable

In any programing language the data falls into two categories called constants and variables. Constants are those which cannot be modified during the program execution. Variables are data that can be modified during the program execution. In the hello word program the phrase "Hello world" is a constant. As in constants there is nothing much to learn let us directly jump into variables.

COBOL Tutorial Class 1: Introduction

Well, one more COBOL tutorial !  Already there are ample COBOL tutorial / free PDFs in the internet.  Why one more ? Well I guess I want to create a tutorial for the users who don’t have the time to go through an entire book or a PDF. This tutorial is going to be short and quick. Let me split this across multiple posts. Here is the first post.

Convert Gregorian date to Julian date in REXX

Using below simple REXX code one can covert Gregorian date to Julian format. Below code convert date with format CCYYMMDD to YYDDD format.

Execute a REXX code in batch

Here is how you can execute a REXX module in batch. This is the way to execute a REXX program using a JCL.  You need to use program IKJEFT01 to invoke a REXX module from a job.

Convert VB to FB

Converting variable block to fixed block file is often necessary in Mainframe. If the VB file has LRECL = n, the corresponding FB file record length will be n-4 as the first 4 bytes of VB file is used for Record Descriptor Word (RDW) containing the integer length of the record in bytes.

Practise rexx at home in windows pc

Many of us want to do REXX programing at home. If you want to do REXX programing  in your PC, you need a REXX interpreter. Regina REXX is one such interpreter you can download and use for free.

Example of skeleton JCL

A skeleton JCL or JCL skel is a JCL template that another program can use with certain parameter and create dynamic JCL on the fly. Today I will show how skeletal JCL works with a simple example. Here is one example of skeleton JCL.

Design ISPF panel for REXX tool

Designing a REXX tool with panel is not a tough task. You just need to learn to design ISPF panel and display panel from REXX code and you might also need to know how to use skeleton JCL and submit a job from REXX program.  So to design your REXX tool with panel you need to know following things.

Remove duplicate records without changing record order using SORT JCL

Whenever SORT utility is used for removing duplicates record order gets changed. Many times that is not the desired result. To remove duplicate records without changing record order use below trick. I have shown below example with file having record length 80. That needs to be changed according to file record length you want.

REXX tool for replacing a particular string in all the members of a PDS

CAWABATC tool can be used for replacing a particular string in all the members of a PDS provided CAFM is available in your shop.  However this does not work fine when the target string is longer than source string and the tool overwrites spaces next to the string to be replaced with the new string.

REXX tool to copy all PDS members to PS

Here is how to copy all PDS members to a single dataset.  Find below the REXX code. The tool can be executed both in front end and batch.