在node.js中一次读取一行文件？

从Node.js v0.12和Node.js
v4.0.0开始，有一个稳定的readline核心模块。这是从文件中读取行的最简单方法，而无需任何外部模块：

const fs = require('fs');const readline = require('readline');async function processLineByLine() {  const fileStream = fs.createReadStream('input.txt');  const rl = readline.createInterface({    input: fileStream,    crlfDelay: Infinity  });  // Note: we use the crlfDelay option to recognize all instances of CR LF  // ('rn') in input.txt as a single line break.  for await (const line of rl) {    // Each line in input.txt will be successively available here as `line`.    console.log(`Line from file: ${line}`);  }}processLineByLine();

或者：

var lineReader = require('readline').createInterface({  input: require('fs').createReadStream('file.in')});lineReader.on('line', function (line) {  console.log('Line from file:', line);});

即使没有final，也可以正确读取最后一行（从Node v0.12或更高版本开始）

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更新
：此示例已添加到Node的API官方文档中。