lazystream

const lazystream = require('lazystream'); const fs = require('fs'); const path = require('path'); // Create a dummy file for reading const inputFile = path.join(__dirname, 'input.txt'); fs.writeFileSync(inputFile, 'Hello, lazy stream!'); // Define the output file const outputFile = path.join(__dirname, 'output.txt'); console.log('Creating lazy streams...'); // Create a lazy readable stream const lazyReadable = new lazystream.Readable(function () { console.log(' -> Actually opening read stream now.'); return fs.createReadStream(inputFile); }); // Create a lazy writable stream const lazyWritable = new lazystream.Writable(function () { console.log(' -> Actually opening write stream now.'); return fs.createWriteStream(outputFile); }); console.log('Lazy streams instantiated, but file handles are not yet open.'); // Pipe the lazy readable to the lazy writable lazyReadable.pipe(lazyWritable) .on('finish', () => { console.log('Piping finished. Content written to output.txt'); const content = fs.readFileSync(outputFile, 'utf8'); console.log('Output file content:', content); // Clean up fs.unlinkSync(inputFile); fs.unlinkSync(outputFile); }) .on('error', (err) => { console.error('Stream error:', err); // Clean up in case of error if (fs.existsSync(inputFile)) fs.unlinkSync(inputFile); if (fs.existsSync(outputFile)) fs.unlinkSync(outputFile); }); console.log('Piping operation initiated. Streams will open on first data access.');