为了将每行作为数组中的一项，在Node.js v18.11.0中添加了一个逐行读取文件的新函数

filehandle.readLines([选项])

这就是如何将此用于文本文件，您希望读取文件并将每行放入数组中

import { open } from 'node:fs/promises';
const arr = [];
myFilereader();
async function myFileReader() {
    const file = await open('./TextFileName.txt');
    for await (const line of file.readLines()) {
        arr.push(line);
    }
    console.log(arr)
}

为了了解更多read Node.js文档，这里有文件系统readlines()的链接: https://nodejs.org/api/fs.html#filehandlereadlinesoptions

我有同样的问题，我已经解决了它与模块逐行

https://www.npmjs.com/package/line-by-line

至少对我来说，无论是在同步模式还是异步模式下，它都很有魅力。

同样，行终止不终止\n的问题可以用选项解决:

{ encoding: 'utf8', skipEmptyLines: false }

行同步处理:

var LineByLineReader = require('line-by-line'),
    lr = new LineByLineReader('big_file.txt');

lr.on('error', function (err) {
    // 'err' contains error object
});

lr.on('line', function (line) {
    // 'line' contains the current line without the trailing newline character.
});

lr.on('end', function () {
    // All lines are read, file is closed now.
}); 

同步:

var fs = require('fs');
var array = fs.readFileSync('file.txt').toString().split("\n");
for(i in array) {
    console.log(array[i]);
}

异步:

var fs = require('fs');
fs.readFile('file.txt', function(err, data) {
    if(err) throw err;
    var array = data.toString().split("\n");
    for(i in array) {
        console.log(array[i]);
    }
});

要将一个大文件读入数组，您可以逐行或逐块读取。

一行一行的参考我这里的答案

var fs = require('fs'),
    es = require('event-stream'),

var lines = [];

var s = fs.createReadStream('filepath')
    .pipe(es.split())
    .pipe(es.mapSync(function(line) {
        //pause the readstream
        s.pause();
        lines.push(line);
        s.resume();
    })
    .on('error', function(err) {
        console.log('Error:', err);
    })
    .on('end', function() {
        console.log('Finish reading.');
        console.log(lines);
    })
);

一块一块的参考本文

var offset = 0;
var chunkSize = 2048;
var chunkBuffer = new Buffer(chunkSize);
var fp = fs.openSync('filepath', 'r');
var bytesRead = 0;
while(bytesRead = fs.readSync(fp, chunkBuffer, 0, chunkSize, offset)) {
    offset += bytesRead;
    var str = chunkBuffer.slice(0, bytesRead).toString();
    var arr = str.split('\n');

    if(bytesRead = chunkSize) {
        // the last item of the arr may be not a full line, leave it to the next chunk
        offset -= arr.pop().length;
    }
    lines.push(arr);
}
console.log(lines);

我只是想添加@finbarr伟大的答案，在异步的例子中的一个小修复:

异步:

var fs = require('fs');
fs.readFile('file.txt', function(err, data) {
    if(err) throw err;
    var array = data.toString().split("\n");
    for(i in array) {
        console.log(array[i]);
    }
    done();
});

@ madphysics, done()释放async。调用。

使用readline(文档)。下面是一个例子，读取一个CSS文件，解析图标并将它们写入json

var results = [];
  var rl = require('readline').createInterface({
    input: require('fs').createReadStream('./assets/stylesheets/_icons.scss')
  });


  // for every new line, if it matches the regex, add it to an array
  // this is ugly regex :)
  rl.on('line', function (line) {
    var re = /\.icon-icon.*:/;
    var match;
    if ((match = re.exec(line)) !== null) {
      results.push(match[0].replace(".",'').replace(":",''));
    }
  });


  // readline emits a close event when the file is read.
  rl.on('close', function(){
    var outputFilename = './icons.json';
    fs.writeFile(outputFilename, JSON.stringify(results, null, 2), function(err) {
        if(err) {
          console.log(err);
        } else {
          console.log("JSON saved to " + outputFilename);
        }
    });
  });