node监听流创建结束

fs.createWriteStream后使用监听end和close都是无效的，需要监听finish

var tmpFile = "/tmp/somefilename.doc";var ws = fs.createWriteStream(tmpFile);ws.on('finish', function() {    // pipe done here, do something with file});var client = url.slice(0, 5) === 'https' ? https : http;client.get(url, function(response) {    return response.pipe(ws);});