Buffer

• Buffer 是二进制数据，只不过呈现形式采用了两位的 16 进制

创建 指定 字节的 Buffer

let buf = Buffer.alloc(10);

通过字符串创建 Buffer

let buf = Buffer.from("hello world");

通过 16 进制创建 Buffer

let buf = Buffer.from([0x68,0x65,0x6c,0x6c,0x6f,0x20,0x77,0x6f,0x72,0x6c,0x64,
]);
// Buffer 转变为可读形式
console.log(buf.toString());

Buffer 的拼接

let buf1 = Buffer.from([0x68, 0x65, 0x6c, 0x6c, 0x6f]);
let buf2 = Buffer.from([0x20, 0x77, 0x6f, 0x72, 0x6c, 0x64]);
// Buffer 的连接
let buf = Buffer.concat([buf1, buf2]);
console.log(buf.toString());

Stream

• 默认会将大文件拆分为 64k 的小文件传输

// 创建一个可读流
let rStream = fs.createReadStream("001.txt");// 创建一个可写流
let wStream = fs.createWriteStream("002.txt");// 设置编码为 utf8。
rStream.setEncoding("UTF8");// 通过管道将每次获取的数据直接写入新文件中。
rStream.pipe(wStream);

通过流读取数据

let rStream = fs.createReadStream("001.txt");let res = "";
// 监听文件读取
rStream.on("data", (chunk) => {res += chunk.toString();
});// 文件读取结束
rStream.on("end", () => {console.log(res);
});// 文件流读取错误
rStream.on("error", (err) => {console.log(err);
});