Modernizing COBOL: Adding a "Today" Field to Your Employee Screen on Linux

Modernizing COBOL: Adding a "Today" Field to Your Employee Screen on Linux

Introduction

Welcome to the first post in our series on modernizing COBOL development on Linux! In this series, we'll explore practical examples of how to enhance your COBOL applications in a modern environment. Today, we'll start with a simple but useful addition: displaying the current date on an employee screen.

Why Date Handling Matters

Date handling is a fundamental aspect of many business applications. Displaying the current date can be useful for various purposes, such as time-stamping records, providing context to users, and ensuring data accuracy.

Before and After

Here's a glimpse of what our employee screen will look like before and after adding the "today" field:

Before:

Employee ID: 12345
Name: John Doe
Department: Sales

After:

Employee ID: 12345
Name: John Doe
Department: Sales
Today: 08/29/2024

The COBOL Code

Let's dive into the COBOL code changes required to achieve this. We'll be using a simplified screen section concept for demonstration.

1. Data Division

First, we define variables to store the current date and format it for display:

COBOL

01  TODAYS-DATE.
    05  TODAYS-YEAR    PIC 9(4).
    05  TODAYS-MONTH   PIC 9(2).
    05  TODAYS-DAY     PIC 9(2).
01  DISPLAY-DATE      PIC X(10).
01  WS-DATE           PIC X(8). *> Work Storage for date
01  TEMP-MONTH        PIC XX.
01  TEMP-DAY          PIC XX.
01  TEMP-YEAR         PIC XXXX.

2. Procedure Division

We use the ACCEPT statement with the DATE clause to get the current date. We then format it for display.

COBOL

*> Get the current date
MOVE FUNCTION CURRENT-DATE TO WS-DATE.
MOVE WS-DATE(1:4) TO TODAYS-YEAR.
MOVE WS-DATE(5:2) TO TODAYS-MONTH.
MOVE WS-DATE(7:2) TO TODAYS-DAY.

*> Format for display (MM/DD/YYYY)
MOVE TODAYS-MONTH TO TEMP-MONTH.
MOVE TODAYS-DAY TO TEMP-DAY.
MOVE TODAYS-YEAR TO TEMP-YEAR.

STRING TEMP-MONTH "/" TEMP-DAY "/" TEMP-YEAR 
    DELIMITED BY SPACE INTO DISPLAY-DATE.

3. Screen Section

Finally, we add the new field to our screen layout. We position it appropriately and include a label.

COBOL

01  SCREEN-LAYOUT.
    05  FILLER        PIC X(5) VALUE SPACES.
    05  EMP-ID-LABEL  PIC X(10) VALUE "Employee ID:".
    05  EMP-ID-FIELD  PIC 9(5).
    05  FILLER        PIC X(5) VALUE SPACES.
    05  NAME-LABEL    PIC X(5) VALUE "Name:".
    05  NAME-FIELD    PIC X(20).
    05  FILLER        PIC X(5) VALUE SPACES.
    05  DEPT-LABEL    PIC X(10) VALUE "Department:".
    05  DEPT-FIELD    PIC X(15).
    05  FILLER        PIC X(5) VALUE SPACES.
    05  TODAY-LABEL   PIC X(6) VALUE "Today:".
    05  DISPLAY-DATE  PIC X(10).

Compilation and Execution

To compile the COBOL program on Linux, you would typically use a command like:

Bash

cobc -x myprogram.cob

And to run it:

Bash

./myprogram

After running the program, the updated employee screen with the "today" field will be displayed.

Explanation and Best Practices

• Date Formats: COBOL offers various date formats. Choose the one that best suits your application's requirements. We used MM/DD/YYYY in this example.
• Error Handling: In a real-world scenario, you should include error handling to ensure the date is valid.
• Performance: For this simple example, performance implications are minimal. However, for more complex date manipulations, consider performance optimization techniques.

Conclusion

In this post, we've demonstrated how to add a "today" field to an employee screen using COBOL on Linux. This is a simple but practical example of how to enhance your COBOL applications with modern features. In the next post, we'll explore input validation to make our employee screen more robust.

Need COBOL Expertise?

If you're looking for guidance on COBOL or any coding challenges, feel free to reach out! We'd love to help you tackle your COBOL projects. 🚀

Email us at: info@pacificw.com

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