nodejs copy视频到当前目录（stream）

方法一：

var fs=require('fs');

var readStream=fs.createReadStream('1.mp4');

var writeStream=fs.createWriteStream('1-stream.mp4');

readStream.on('data',function(chunk){

if( writeStream.write(chunk) ===false ){

console.log('still cached');

readStream.pause();

}

})

readStream.on('end',function(){

writeStream.end();

})

writeStream.on('drain',function(){

console.log('data drains');

readStream.resume();

})

方法二（pipe|管道）：

var fs= require('fs');

fs.createReadStream('1.mp4').pipe(fs.createWriteStream('1-pipe.mp4'));