readFromEnd.js

const fs = require('fs');

function readFromEnd(filePath, chunkSize = 1024) {
  const stats = fs.statSync(filePath);
  let position = stats.size;
  let buffer = '';
  const lines = [];

  const stream = fs.createReadStream(filePath, {
    highWaterMark: chunkSize,
    start: Math.max(0, position - chunkSize),
    end: position - 1
  });

  stream.on('data', (chunk) => {
    buffer = chunk.toString() + buffer;
    let newlineIndex;

    while ((newlineIndex = buffer.lastIndexOf('\n')) !== -1) {
      const line = buffer.slice(newlineIndex + 1);
      lines.push(line);
      buffer = buffer.slice(0, newlineIndex);
    }

    position -= chunkSize;
    if (position > 0) {
      stream.close();
      stream.open(filePath, {
        highWaterMark: chunkSize,
        start: Math.max(0, position - chunkSize),
        end: position - 1
      });
    } else {
      if (buffer.length > 0) {
        lines.push(buffer);
      }
      console.log('Finished reading file:', lines);
    }
  });

  stream.on('end', () => {
    if (buffer.length > 0) {
      lines.push(buffer);
    }
    console.log('Finished reading file:', lines);
  });

  stream.on('error', (err) => {
    console.error('Error reading file:', err);
  });
}

// Example usage
readFromEnd('path/to/your/file.jsonld');