无限文件监视器 [英] Infinite file watcher

问题描述

您好，我试图在Dart中实现文件监视器。问题是，我不知道如何使流永远的列表。在我的代码 print 语句仅在文件更改时触发一次。我尝试了 while（true）{} ，但没有影响。

Hello I'm trying to implement file watcher in Dart. And the problem is that I can't figure out how to make forever lister for stream. In my code print statement fires only once, when file was changed. I tried while(true){} but didn't make affect.

import "dart:io";


void main(){
  List<String> paths = ['any.dart'];
  paths.forEach((fp){
    File f = new File(fp);
    f.watch().listen((e){
      print(e);
    });
  });
}

Dart信息： Dart VM版本：1.4.0 （Tue May 20 04:56:35 2014）onlinux_x64

推荐答案

查看watch函数的文档：

Please have a look into the doc of the watch function:

The implementation uses platform-dependent event-based APIs for receiving file-system notifications, thus behavior depends on the platform. 

* Windows: Uses ReadDirectoryChangesW. The implementation only 
    supports watching directories. Recursive watching is supported.

* `Linux`: Uses `inotify`. The implementation supports watching both 
    files and directories. Recursive watching is not supported.
    Note: When watching files directly, delete events might not happen
    as expected.

* `Mac OS`: Uses `FSEvents`. The implementation supports watching both 
    files and directories. Recursive watching is supported.

这意味着这不会在Windows上工作。对于你的问题，它说：

This means this won't work on Windows. For you problem it says:

The returned value is an endless broadcast [Stream], that only stops when
one of the following happends:

  * The [Stream] is canceled, e.g. by calling `cancel` on the
     [StreamSubscription].
  * The [FileSystemEntity] being watches, is deleted.

这意味着您的文件被删除，流被取消或这是一个错误，

This means either your file got deleted, the stream got canceled or this is a bug and you should file a ticket for this.

在Windows上没有任何反应。在Mac我得到这与您的代码：

On Windows there is no reaction for me. On Mac I get this with your code:

FileSystemModifyEvent('test_file_watcher.dart', contentChanged=true)
FileSystemModifyEvent('test_file_watcher.dart', contentChanged=true)
FileSystemModifyEvent('test_file_watcher.dart', contentChanged=true)
FileSystemModifyEvent('test_file_watcher.dart', contentChanged=true)
FileSystemModifyEvent('test_file_watcher.dart', contentChanged=true)
FileSystemModifyEvent('test_file_watcher.dart', contentChanged=true)

$ b b

如何测试你的代码？我简单地编辑和保存我的文件。所以它的工作对我很好。您使用哪个版本？

How do you test your code? I simple edited and saved my file. So it's working great for me. Which version are you using?

回报
Robert

Regards Robert

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