COBOL Debugging Techniques

Code Example

## COBOL Debugging Techniques

Effective debugging in COBOL requires understanding of compiler options, runtime diagnostics, and structured testing approaches.

### Compiler Debug Options

- **TEST**: Enable interactive debugging
- **SOURCE**: Include source in listing
- **MAP/XREF**: Cross-reference listing
- **SSRANGE**: Subscript range checking
- **CHECK**: Additional runtime checks

### DISPLAY Debugging

Strategic DISPLAY statements to trace:
- Entry/exit of paragraphs
- Variable values at key points
- Condition evaluations
- Loop iterations

### USE FOR DEBUGGING

\`\`\`cobol
USE FOR DEBUGGING ON procedure-name/ALL PROCEDURES
\`\`\`

### Common Issues

1. **Data exceptions (S0C7)**: Invalid numeric data
2. **Subscript errors (S0C4)**: Out of range
3. **File status errors**: Check after every I/O
4. **Logic errors**: Trace program flow

### Best Practices

- Use meaningful variable names
- Check FILE STATUS after every I/O
- Validate input data early
- Use structured programming
- Comment complex logic