blocks|key|375978|text|我只想补充一点，使用console.log()输出派生进程的缓冲区字符串有一个小问题，那就是它添加了换行符，这可能会将派生进程的输出分散到其他行上。如果您使用process.stdout.write()而不是console.log()输出stdout或stderr，那么您将从衍生的进程“按原样”获得控制台输出。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|375979|我在这里看到了解决方案：Node.js:+printing+to+console+without+a+trailing+newline?|375980|希望这对使用上面的解决方案的人有帮助(这是一个很好的实时输出的解决方案，即使它来自文档)。|375981|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/6157497/node-js-printing-to-console-without-a-trailing-newline^0|A|D|27|M|2W|D|3B|6|3I|6|0|C|1K|0|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@$9|S|A|T|B|C]|$9|U|A|V|B|C]|$9|W|A|X|B|C]|$9|Y|A|Z|B|C]|$9|10|A|11|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|12|8|@]|D|@$9|13|A|14|1|15]]|E|$]]|$1|H|3|I|5|6|7|16|8|@]|D|@]|E|$]]|$1|J|3|-4|5|6|7|17|8|@]|D|@]|E|$]]]|K|$L|$5|M|N|O|E|$P|Q]]]]

I'd just like to add that one small issue with outputting the buffer strings from a spawned process with <code>console.log()</code> is that it adds newlines, which can spread your spawned process output over additional lines. If you output <code>stdout</code> or <code>stderr</code> with <code>process.stdout.write()</code> instead of <code>console.log()</code>, then you'll get the console output from the spawned process 'as is'.

I saw that solution here:
<a href="https://stackoverflow.com/questions/6157497/node-js-printing-to-console-without-a-trailing-newline">Node.js: printing to console without a trailing newline?</a>

Hope that helps someone using the solution above (which is a great one for live output, even if it is from the documentation).

blocks|key|375995|text|exec还将返回一个作为EventEmitter的ChildProcess对象。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|375996|var+exec+=+require('child_process').exec;
var+coffeeProcess+=+exec('coffee+-cw+my_file.coffee');

coffeeProcess.stdout.on('data',+function(data)+{
++++console.log(data);+
});|code-block|syntax|javascript|375997|或者将子进程的标准输出pipe到主标准输出。|375998|coffeeProcess.stdout.pipe(process.stdout);|375999|或者使用spawn继承stdio|376000|spawn('coffee+-cw+my_file.coffee',+{+stdio:+'inherit'+});|376001|entityMap^0|0|4|0|0|B|4|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|Y|8|@$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|11|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|12|8|@]|D|@]|E|$]]|$1|Q|3|R|5|H|7|13|8|@]|D|@]|E|$I|J]]|$1|S|3|-4|5|6|7|14|8|@]|D|@]|E|$]]]|T|$]]

<code>exec</code> will also return a ChildProcess object that is an EventEmitter. 

<pre><code>var exec = require('child_process').exec;
var coffeeProcess = exec('coffee -cw my_file.coffee');

coffeeProcess.stdout.on('data', function(data) {
 console.log(data); 
});
</code></pre>

OR <code>pipe</code> the child process's stdout to the main stdout. 

<pre><code>coffeeProcess.stdout.pipe(process.stdout);
</code></pre>

OR inherit stdio using spawn

<pre><code>spawn('coffee -cw my_file.coffee', { stdio: 'inherit' });
</code></pre>

blocks|key|591845|text|受Nathanael+Smith的答案和Eric+Freese的评论的启发，它可以像这样简单：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|591846|var+exec+=+require('child_process').exec;
exec('coffee+-cw+my_file.coffee').stdout.pipe(process.stdout);|code-block|syntax|javascript|591847|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Inspired by Nathanael Smith's answer and Eric Freese's comment, it could be as simple as:

<pre><code>var exec = require('child_process').exec;
exec('coffee -cw my_file.coffee').stdout.pipe(process.stdout);
</code></pre>

blocks|key|591873|text|在回顾了所有其他答案后，我得出了以下结论：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|591874|function+oldSchoolMakeBuild(cb)+{
++++var+makeProcess+=+exec('make+-C+./oldSchoolMakeBuild',
+++++++++function+(error,+stdout,+stderr)+{
+++++++++++++stderr+&&+console.error(stderr);
+++++++++++++cb(error);
++++++++});
++++makeProcess.stdout.on('data',+function(data)+{
++++++++process.stdout.write('oldSchoolMakeBuild:+'%2B+data);
++++});
}|code-block|syntax|javascript|591875|有时data会是多行的，所以oldSchoolMakeBuild标题会在多行中出现一次。但这还不足以让我改变它。|offset|length|style|CODE|591876|entityMap^0|0|0|2|4|E|I|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]|$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|N|$]]

After reviewing all the other answers, I ended up with this:

<pre><code>function oldSchoolMakeBuild(cb) {
 var makeProcess = exec('make -C ./oldSchoolMakeBuild',
 function (error, stdout, stderr) {
 stderr &amp;&amp; console.error(stderr);
 cb(error);
 });
 makeProcess.stdout.on('data', function(data) {
 process.stdout.write('oldSchoolMakeBuild: '+ data);
 });
}
</code></pre>

Sometimes <code>data</code> will be multiple lines, so the <code>oldSchoolMakeBuild</code> header will appear once for multiple lines. But this didn't bother me enough to change it.

blocks|key|591907|text|已经有几个答案，但是没有一个提到实现这一点的最佳(也是最简单的)方法，那就是使用spawn和{+stdio:+'inherit'+}+option。例如，当显示来自git+clone的进度信息时，它似乎能产生最准确的输出。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|591908|只需执行以下操作：|591909|var+spawn+=+require('child_process').spawn;

spawn('coffee',+['-cw',+'my_file.coffee'],+{+stdio:+'inherit'+});|code-block|syntax|javascript|591910|感谢@MorganTouvereyQuilling在this+comment中指出了这一点。|591911|entityMap|0|LINK|mutability|MUTABLE|url|https://nodejs.org/api/child_process.html#child_process_options_stdio|1|https://stackoverflow.com/questions/10232192/exec-display-stdout-live/43477289#comment73321259_30084906^0|14|5|1A|K|2A|9|1A|R|0|0|0|0|Q|C|1|0^^$0|@$1|2|3|4|5|6|7|Y|8|@$9|Z|A|10|B|C]|$9|11|A|12|B|C]|$9|13|A|14|B|C]]|D|@$9|15|A|16|1|17]]|E|$]]|$1|F|3|G|5|6|7|18|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|19|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|1A|8|@]|D|@$9|1B|A|1C|1|1D]]|E|$]]|$1|O|3|-4|5|6|7|1E|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]|W|$5|R|S|T|E|$U|X]]]]

There are already several answers however none of them mention the best (and easiest) way to do this, which is using <code>spawn</code> and the <a href="https://nodejs.org/api/child_process.html#child_process_options_stdio" rel="noreferrer"><code>{ stdio: 'inherit' }</code> option</a>. It seems to produce the most accurate output, for example when displaying the progress information from a <code>git clone</code>.

Simply do this:

<pre><code>var spawn = require('child_process').spawn;

spawn('coffee', ['-cw', 'my_file.coffee'], { stdio: 'inherit' });
</code></pre>

Credit to @MorganTouvereyQuilling for pointing this out in <a href="https://stackoverflow.com/questions/10232192/exec-display-stdout-live/43477289#comment73321259_30084906">this comment</a>.

blocks|key|376150|text|我发现在我的实用程序中添加一个自定义的exec脚本是很有帮助的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|376151|utilities.js|376152|const+{+exec+}+=+require('child_process')

module.exports.exec+=+(command)+=>+{
++const+process+=+exec(command)

++process.stdout.on('data',+(data)+=>+{
++++console.log('stdout:+'+%2B+data.toString())
++})

++process.stderr.on('data',+(data)+=>+{
++++console.log('stderr:+'+%2B+data.toString())
++})

++process.on('exit',+(code)+=>+{
++++console.log('child+process+exited+with+code+'+%2B+code.toString())
++})
}|code-block|syntax|javascript|376153|app.js|376154|const+{+exec+}+=+require('./utilities.js')

exec('coffee+-cw+my_file.coffee')|376155|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

I have found it helpful to add a custom exec script to my utilities that do this.

utilities.js

<pre><code>const { exec } = require('child_process')

module.exports.exec = (command) =&gt; {
 const process = exec(command)

 process.stdout.on('data', (data) =&gt; {
 console.log('stdout: ' + data.toString())
 })

 process.stderr.on('data', (data) =&gt; {
 console.log('stderr: ' + data.toString())
 })

 process.on('exit', (code) =&gt; {
 console.log('child process exited with code ' + code.toString())
 })
}
</code></pre>

app.js

<pre><code>const { exec } = require('./utilities.js')

exec('coffee -cw my_file.coffee')
</code></pre>

blocks|key|592020|text|child_process.spawn返回一个带有标准输出和标准错误流的对象。您可以点击stdout流来读取子进程发送回Node的数据。作为流的stdout具有流所具有的"data“、"end”和其他事件。当您希望子进程将大量数据返回到节点图像处理、读取二进制数据等时，spawn最适合使用。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|592021|因此，您可以使用下面使用的child_process.spawn来解决您的问题。|592022|var+spawn+=+require('child_process').spawn,
ls+=+spawn('coffee+-cw+my_file.coffee');

ls.stdout.on('data',+function+(data)+{
++console.log('stdout:+'+%2B+data.toString());
});

ls.stderr.on('data',+function+(data)+{
++console.log('stderr:+'+%2B+data.toString());
});

ls.on('exit',+function+(code)+{
++console.log('code+'+%2B+code.toString());
});|code-block|syntax|javascript|592023|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

child_process.spawn returns an object with stdout and stderr streams. 
You can tap on the stdout stream to read data that the child process sends back to Node. stdout being a stream has the "data", "end", and other events that streams have. spawn is best used to when you want the child process to return a large amount of data to Node - image processing, reading binary data etc.

so you can solve your problem using child_process.spawn as used below.

<pre><code>var spawn = require('child_process').spawn,
ls = spawn('coffee -cw my_file.coffee');

ls.stdout.on('data', function (data) {
 console.log('stdout: ' + data.toString());
});

ls.stderr.on('data', function (data) {
 console.log('stderr: ' + data.toString());
});

ls.on('exit', function (code) {
 console.log('code ' + code.toString());
});
</code></pre>

blocks|key|592095|text|下面是一个用typescript编写的异步助手函数，它似乎能帮我解决这个问题。我猜这对长时间的流程不起作用，但对某些人来说可能还是很方便的？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|592096|import+*+as+child_process+from+"child_process";

private+async+spawn(command:+string,+args:+string[]):+Promise<{code:+number+%7C+null,+result:+string}>+{
++++return+new+Promise((resolve,+reject)+=>+{
++++++++const+spawn+=+child_process.spawn(command,+args)
++++++++let+result:+string
++++++++spawn.stdout.on('data',+(data:+any)+=>+{
++++++++++++if+(result)+{
++++++++++++++++reject(Error('Helper+function+does+not+work+for+long+lived+proccess'))
++++++++++++}
++++++++++++result+=+data.toString()
++++++++})
++++++++spawn.stderr.on('data',+(error:+any)+=>+{
++++++++++++reject(Error(error.toString()))
++++++++})
++++++++spawn.on('exit',+code+=>+{
++++++++++++resolve({code,+result})
++++++++})
++++})
}|code-block|syntax|javascript|592097|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Here is an async helper function written in typescript that seems to do the trick for me. I guess this will not work for long-lived processes but still might be handy for someone?

<pre><code>import * as child_process from "child_process";

private async spawn(command: string, args: string[]): Promise&lt;{code: number | null, result: string}&gt; {
 return new Promise((resolve, reject) =&gt; {
 const spawn = child_process.spawn(command, args)
 let result: string
 spawn.stdout.on('data', (data: any) =&gt; {
 if (result) {
 reject(Error('Helper function does not work for long lived proccess'))
 }
 result = data.toString()
 })
 spawn.stderr.on('data', (error: any) =&gt; {
 reject(Error(error.toString()))
 })
 spawn.on('exit', code =&gt; {
 resolve({code, result})
 })
 })
}
</code></pre>

I have this simple script :

<pre><code>var exec = require('child_process').exec;

exec('coffee -cw my_file.coffee', function(error, stdout, stderr) {
 console.log(stdout);
});
</code></pre>

where I simply execute a command to compile a coffee-script file. But stdout never get displayed in the console, because the command never ends (because of the -w option of coffee).
If I execute the command directly from the console I get message like this :

<pre><code>18:05:59 - compiled my_file.coffee
</code></pre>

My question is : is it possible to display these messages with the node.js exec ? If yes how ? !

Thanks

Exec : display stdout "live"

图像处理

我有一个简单的脚本：var exec = require('child_process').exec;exec('coffee -cw my_file.coffee', function(error, stdout, stderr) {    console.log(stdout);});在这里，我只需执行一个命令来编...

问Exec :显示标准输出"live“
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