The readline module enables interactive command-line interfaces and line-by-line input processing.
Basic Usage#
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Promises API (Node 17+)#
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Event-Based Interface#
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Reading Files Line by Line#
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Interactive Menu#
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Password Input#
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Auto-Complete#
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Cursor Control#
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History#
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Best Practices#
Interface:
✓ Use promises API when available
✓ Handle close events properly
✓ Implement SIGINT handling
✓ Clean up resources
File Processing:
✓ Use async iterator for large files
✓ Set crlfDelay for cross-platform
✓ Handle stream errors
✓ Process in chunks if needed
CLI:
✓ Provide clear prompts
✓ Implement auto-complete
✓ Support command history
✓ Handle edge cases
Avoid:
✗ Forgetting to close interface
✗ Blocking event loop
✗ Ignoring input validation
✗ Memory issues with large files
Conclusion#
The readline module enables interactive CLI applications and efficient line-by-line file processing. Use the promises API for cleaner async code, implement auto-complete for better UX, and leverage cursor control for progress indicators. Always handle cleanup and edge cases properly.