file - Node : How to wait until a file is completed before processing it?

Question

我的问题是我无法确定文件何时成功写入以及文件何时关闭。考虑以下情况:

var fs = require('fs');
var outs = fs.createWriteStream('/tmp/file.txt');
var ins = <some input stream>

...
ins.on('data', function(chunk) { out.write(chunk); });
...
ins.on('end', function() {
   outs.end();
   outs.destroySoon();
   fs.stat('/tmp/file.txt', function(err, info) {

      // PROBLEM: Here info.size will not match the actual number of bytes.
      // However if I wait for a few seconds and then call fs.stat the file has been flushed.
   });
});

那么，我如何强制或以其他方式确保文件在访问之前已被正确刷新？我需要确保该文件存在且完整，因为我的代码必须生成一个外部进程来读取和处理该文件。

Answer 1

在可写流中对文件进行后处理 close事件:

outs.on('close', function() {
  <<spawn your process>>
});

此外，end 之后不需要destroySoon，它们是one and the same .