如何在Javascript中只读入文件的第一行？

const fs = require('fs');

function readFirstLine(filePath) {
  return new Promise((resolve, reject) => {
    const stream = fs.createReadStream(filePath, { encoding: 'utf8' });
    let firstLine = '';

    stream.on('data', (chunk) => {
      const lines = chunk.split('\n');
      firstLine += lines[0];
      if (lines.length > 1) {
        stream.destroy(); // Stop reading after the first line
      }
    });

    stream.on('end', () => {
      resolve(firstLine);
    });

    stream.on('error', (err) => {
      reject(err);
    });
  });
}

// 使用示例
readFirstLine('path/to/your/file.txt')
  .then(firstLine => {
    console.log('第一行内容:', firstLine);
  })
  .catch(err => {
    console.error('读取文件时发生错误:', err);
  });