NodeJS：扔掉; //使用child_process spawn方法时未处理的'error'事件（events.js：72）

I've made an node.js app to list all .txt files from a directory recursively and, for each one, do some stuff.

我已经创建了一个node.js应用程序，以递归方式列出目录中的所有.txt文件，并为每个文件执行一些操作。

Here's my app.js:

这是我的app.js：

var spawn = require('child_process').spawn,
    dir = spawn('dir', ['*.txt', '/b']);

dir.stdout.on('data', function (data) {
    //do some stuff with each stdout line...
    console.log('stdout: ' + data);
});

dir.stderr.on('data', function (data) {
    //throw errors
    console.log('stderr: ' + data);
});

dir.on('close', function (code) {
    console.log('child process exited with code ' + code);
});

When I run node app.js via console, I get the error message below:

当我通过控制台运行节点app.js时，我收到以下错误消息：

events.js:72
        throw er; // Unhandled 'error' event
              ^
Error: spawn ENOENT
    at errnoException (child_process.js:980:11)
    at Process.ChildProcess._handle.onexit (child_process.js:771:34)

I'm using node v0.10.13 at win32 environment.

我在win32环境中使用节点v0.10.13。

I do this way (spawn) because I want to handle stdout line by line (the exec method release entire stdout as one string).

我这样做（spawn）因为我想逐行处理stdout（exec方法将整个stdout释放为一个字符串）。

* UPDATE *

*更新*

By the way, using spawn for child_process does not guarantee that the output for cmd dir will be line by line. I've created a question for that too.

顺便说一下，使用spawn for child_process并不能保证cmd dir的输出是逐行的。我也为此创建了一个问题。

2 个解决方案

#1

That happen because dir is not a executable in Windows. It's a command from the shell.
The solution for your problem is the following:

这是因为dir不是Windows中的可执行文件。这是来自shell的命令。您的问题的解决方案如下：

var dir = spawn('cmd', ['/c', 'dir']);
dir.stdout.on("data", function() {
    // do things
})

This exact problem was here also.

这个确切的问题也在这里。

#2

Several things:

几件事：

dir is not a real executable in windows, so node.js cannot find the program you want to run.
dir不是Windows中的真正可执行文件，因此node.js找不到您要运行的程序。
You didn't bind an 'error' handler to your child process and the event was turned into an exception that crashed your node instance. Do this:
您没有将“错误”处理程序绑定到子进程，并且该事件变为导致节点实例崩溃的异常。做这个：

dir.on('error', function (err) {
  console.log('dir error', err);
});

Use fs.readdir instead. It's a standard node.js API that does the same thing.
请改用fs.readdir。它是一个标准的node.js API，它做同样的事情。

#1