Understand your legacy COBOL code

Example COBOL Program Documentation (example-cobol.cob) 🏷️

Welcome to the Markdown Documentation of the file example-cobol.cob! In this document, we will explore:

1. Introduction ✨
2. Program Overview 🏗️
3. Detailed Code Explanation 💡
4. Flowchart Diagram (Conceptual) 🔀
5. Key Variables and Purpose 📋
6. File Input & Output Explanation 🔍
7. Compilation & Execution Instructions ⚙️
8. Conclusion 💬

Introduction ✨

This COBOL program, named PAYROLL, processes employee salary data from an input file and generates a payroll report. It demonstrates typical COBOL constructs such as:

• DIVISIONS (IDENTIFICATION, ENVIRONMENT, DATA, and PROCEDURE).
• FILE I/O (reading from an input file, writing to an output file).
• STRING manipulation.
• COMPUTE statements for tax calculation and net salary computations.
• PERFORM UNTIL loops for file record processing.

Program Overview 🏗️

The example-cobol.cob file performs the following tasks:

1. Open Input File (EMP-IN): Reads employee data which includes Employee ID, Name, and Gross Salary.
2. Open Output File (EMP-OUT): Writes lines of text including a header, each employee’s payroll details, and totals at the end.
3. Process Records and compute each employee’s Net Salary by applying a TAX-RATE (default 20%).
4. Accumulate Totals of gross and net salaries for all processed employees.
5. Write the summarizing totals to the output file and close all files.

Key Points in the Code

• IDENTIFICATION DIVISION: Defines the program name (PAYROLL), author, and date.
• ENVIRONMENT DIVISION: Specifies the files and how they are organized.
• DATA DIVISION:
  • FILE SECTION: Layout of records for input and output files.
  • WORKING-STORAGE SECTION: Temporary variables, flags, accumulators (for totals).
• PROCEDURE DIVISION: Main logic including opening files, processing records in a loop, formatting output, and closing files.

Flowchart Diagram (Conceptual) 🔀

 ┌─────────────────────────────┐
 │        Start Program        │
 └─────────────────────────────┘
               │
               ▼
 ┌─────────────────────────────┐
 │ Open EMP-IN & EMP-OUT Files │
 └─────────────────────────────┘
               │
               ▼
 ┌─────────────────────────────┐
 │   Write Report Header Line  │
 └─────────────────────────────┘
               │
               ▼
 ┌───────────────────────────────────┐
 │                 Read             │
 │            EMP-IN RECORD         │
 └───────────────────────────────────┘
               │
         ┌─────┴─────────────────┐
         │  End of EMP-IN? (Y/N) │
         └─────┬─────────────────┘
               ▼ (No)
 ┌─────────────────────────────┐
 │   Increment Employee Count  │
 └─────────────────────────────┘
               │
               ▼
 ┌─────────────────────────────┐
 │  Compute Net Salary =       │
 │ Gross - (Gross * TAX-RATE)  │
 └─────────────────────────────┘
               │
               ▼
 ┌─────────────────────────────┐
 │ Accumulate Gross & Net      │
 └─────────────────────────────┘
               │
               ▼
 ┌─────────────────────────────┐
 │  Format and Write Employee  │
 │       Detail to Output      │
 └─────────────────────────────┘
               │
               └───────── (Loop back to Read next record)
               │
               ▼ (Yes, End)
 ┌─────────────────────────────┐
 │ Write Totals to Output File │
 └─────────────────────────────┘
               │
               ▼
 ┌─────────────────────────────┐
 │   Close EMP-IN & EMP-OUT    │
 └─────────────────────────────┘
               │
               ▼
 ┌─────────────────────────────┐
 │          Stop Run           │
 └─────────────────────────────┘
          

Key Variables and Purpose 📋

File Input & Output Explanation 🔍

• EMP-IN:
  • File: EMPLOYEE.DAT
  • Contains employee records with Employee ID, Name, and Gross Salary.
• EMP-OUT:
  • File: PAYROLL.RPT
  • Contains the formatted payroll report including details for each employee and summary totals.

Compilation & Execution Instructions ⚙️

1. Compilation (using GnuCOBOL):

   
   cobc -x example-cobol.cob -o payroll
                 

2. Execution:
   • Ensure EMPLOYEE.DAT is available.
   • Run the executable:

     
     ./payroll
                       

   • The report will be generated in PAYROLL.RPT.

Conclusion 💬

This documentation outlines the core functionality of the PAYROLL COBOL program. It demonstrates how employee data is read, processed, and summarized into a payroll report. Use this guide to better understand how legacy COBOL programs work and how you can extend or modernize them.

🏁 End of Documentation

Enjoy exploring COBOL and let DocuWriter.ai simplify your legacy projects!