这是使用流在一行代码中复制文件的好方法：

var fs = require('fs');

fs.createReadStream('test.log').pipe(fs.createWriteStream('newLog.log'));

在节点v8.5.0中，添加了copyFile

const fs = require('fs');

// destination.txt will be created or overwritten by default.
fs.copyFile('source.txt', 'destination.txt', (err) => {
  if (err) throw err;
  console.log('source.txt was copied to destination.txt');
});