let path =require('path');
let fs = require('fs');
let str = path.join(__dirname,'jiaody.txt');
fs.writeFile(str,'jiaoooo','utf-8',function(err){
if(err){
throw new Error('写入文件失败')
}else{
console.log('success')
}
})
let path =require('path');
let fs = require('fs');
let str = path.join(__dirname,'jiaody.txt');
fs.appendFile(str,'追加的数据',function(err){
if(err){
throw new Error("追加数据失败");
}else{
console.log("追加数据成功");
}
})
分批读取createReadStream和分批写入createWriteStream
let readPath = path.join(__dirname, "test.mp4");
let writePath = path.join(__dirname, "abc.mp4");
// 2.创建一个读取流
let readStream = fs.createReadStream(readPath);
// 3.创建一个写入流
let writeStream = fs.createWriteStream(writePath);
// 4.监听读取流事件
readStream.on("open", function () {
console.log("表示数据流和文件建立关系成功");
});
readStream.on("error", function () {
console.log("表示数据流和文件建立关系失败");
});
readStream.on("data", function (data) {
// console.log("表示通过读取流从文件中读取到了数据", data);
writeStream.write(data);
});
readStream.on("close", function () {
console.log("表示数据流断开了和文件的关系, 并且数据已经读取完毕了");
writeStream.end();
});
// 5.监听写入流的事件
writeStream.on("open", function () {
console.log("表示数据流和文件建立关系成功");
});
writeStream.on("error", function () {
console.log("表示数据流和文件建立关系失败");
});
writeStream.on("close", function () {
console.log("表示数据流断开了和文件的关系");
});
pipe文件拷贝
let readPath = path.join(__dirname, "test.mp4");
let writePath = path.join(__dirname, "abc.mp4");
// 2.创建一个读取流
let readStream = fs.createReadStream(readPath);
// 3.创建一个写入流
let writeStream = fs.createWriteStream(writePath);
// 利用读取流的管道方法来快速的实现文件拷贝
readStream.pipe(writeStream);