NodeJs的Stream(流)应用

const fs = require('fs');
var readStream = fs.createReadStream('./data.text')
var count = 0
var str = '';
// 监听正在读取
readStream.on('data', (data) => {
    str += data;
    count++;
})
// 监听读取结束
readStream.on('end', () => {
    console.log(str)
    console.log(count)
})
// 监听读取错误
readStream.on('err', (err) => {
    console.log(err)
})

const fs = require('fs');
var str = ''
for (let i = 0; i < 500; i++) {
    str += '写入数据\n'
}
var writeStream = fs.createWriteStream('./data.text')
writeStream.write(str)
// 标记写入完成
writeStream.end();
writeStream.on('finish', () => {
    console.log('写入完成')
})

const fs = require('fs');
var readStream = fs.createReadStream('./data.text')
var writeStream = fs.createWriteStream('./getData.text')
// 管道流 复制文件
readStream.pipe(writeStream)