node实现将大CSV文件拆分小CSV

const fs = require('fs');

const readline = require('readline');

// 定义输入文件的路径和输出文件的目录

const inputFilePath = '大的CSV文件.csv';

const outputDirectory = 'result';

 // 每个小文件包含的行数

const linesPerFile = 250000;

// 创建输出目录

if (!fs.existsSync(outputDirectory)) {

    fs.mkdirSync(outputDirectory);

}

// 读取大的CSV文件

const readStream = fs.createReadStream(inputFilePath, 'utf-8');

const rl = readline.createInterface({

    input: readStream,

    crlfDelay: Infinity,

});

let fileCounter = 1;

let writeStream = createWriteStream();

/**创建写入流 */

function createWriteStream() {

    const outputFilePath = `${outputDirectory}/小的CSV文件_${fileCounter}.csv`;

    fileCounter++;

    const ws = fs.createWriteStream(outputFilePath);

    // 读取标题行并添加到新文件

    ws.write(' \n');

    return ws;

}

let currentLine = 0;

rl.on('line', (line) => {

    if (currentLine > 0) {

        writeStream.write(line + '\n');

    }

    currentLine++;

    if (currentLine >= linesPerFile) {

        writeStream.end();

        writeStream = createWriteStream();

        currentLine = 0;

    }

});

rl.on('close', () => {

    writeStream.end();

    console.log('拆分完成！');

});