9、Node.jsStream(流)

var fs &＃61; require(&＃39;fs&＃39;);
var data &＃61; &＃39;&＃39;;
// 创建可读流
var readStream &＃61; fs.createReadStream(&＃39;read_source.txt&＃39;);// 设置编码为 utf8
readStream.setEncoding(&＃39;UTF8&＃39;);// 处理流事件 --> data, end, and error
readStream.on(&＃39;data&＃39;, function (chunk) {data &＃61; chunk;
});readStream.on(&＃39;end&＃39;, function () {console.log(data);
});readStream.on(&＃39;error&＃39;, function (err) {console.log(err.stack)
});console.log(&＃39;程序执行完毕&＃39;);

var fs &＃61; require(&＃39;fs&＃39;);
var data &＃61; &＃39;love A&＃39;;// 创建写入流&＃xff0c;写入到文件 output.txt 中
var writerStream &＃61; fs.createWriteStream(&＃39;output.txt&＃39;);// 使用 utf8 编码写入数据
writerStream.write(data, &＃39;utf8&＃39;);// 标记文件末尾
writerStream.end();// 处理流事件 --> finish and error
writerStream.on(&＃39;finish&＃39;, function () {console.log(&＃39;写入完毕&＃39;);
});writerStream.on(&＃39;error&＃39;, function (err) {console.log(err.stack);
});console.log(&＃39;程序执行完毕&＃39;);

var fs &＃61; require(&＃39;fs&＃39;);var readStream &＃61; fs.createReadStream(&＃39;read_source.txt&＃39;);
var writerStream &＃61; fs.createWriteStream(&＃39;output2.txt&＃39;);// 管道读写操作
// 读取 read_source.txt 文件内容&＃xff0c;并将内容写入到 output2.txt中
readStream.pipe(writerStream);console.log(&＃39;程序执行完毕&＃39;);

var fs &＃61; require(&＃39;fs&＃39;);
var zlib &＃61; require(&＃39;zlib&＃39;);// 压缩 read_source.txt 成 read_source.txt.gz
var readStream &＃61; fs.createReadStream(&＃39;read_source.txt&＃39;);
var gzip &＃61; zlib.createGzip();
var writeStream &＃61; fs.createWriteStream(&＃39;read_source.txt.gz&＃39;);readStream.pipe(gzip);
gzip.pipe(writeStream);console.log(&＃39;文件压缩完成&＃39;);

var fs &＃61; require(&＃39;fs&＃39;);
var zlib &＃61; require(&＃39;zlib&＃39;);// 解压 read_source.txt.gz 成 depress.txt
var readStream &＃61; fs.createReadStream(&＃39;read_source.txt.gz&＃39;);
var gunzip &＃61; zlib.createGunzip();
var writeStream &＃61; fs.createWriteStream(&＃39;depress.txt&＃39;);readStream.pipe(gunzip);
gunzip.pipe(writeStream);console.log(&＃39;文件解压完成&＃39;);