首页 \ 问答 \ 执行：显示stdout“活”(Exec : display stdout “live”)

执行：显示stdout“活”(Exec : display stdout “live”)

 我有这个简单的脚本：  
var exec = require('child_process').exec;

exec('coffee -cw my_file.coffee', function(error, stdout, stderr) {
    console.log(stdout);
});
 
 在那里我只需执行一个命令来编译一个咖啡脚本文件。 但是stdout不会在控制台中显示，因为命令永远不会结束（因为-w选项的咖啡）。 如果我直接从控制台执行命令，我会得到如下消息：  
18:05:59 - compiled my_file.coffee
 
 我的问题是：可以用node.js exec显示这些消息吗？ 如果是的话， ！  
 谢谢 

I have this simple script : 
var exec = require('child_process').exec;

exec('coffee -cw my_file.coffee', function(error, stdout, stderr) {
    console.log(stdout);
});
 
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 : 
18:05:59 - compiled my_file.coffee
 
My question is : is it possible to display these messages with the node.js exec ? If yes how ? ! 
Thanks

原文：https://stackoverflow.com/questions/10232192

更新时间：2022-08-26 14:08

最满意答案

 在最新版本的GHC中，可以使用setAllocationCounter和enableAllocationLimit来设置每个线程的分配计数器和限制。 当限制被设置并且计数器达到0时，线程接收异步异常。  
 计数器测量分配 ，而不是现场组的大小。 例如，这个代码达到了极限，尽管它的现场设置永远不会变得很大：  
{-# LANGUAGE NumDecimals #-}
module Main where

import Data.Foldable (for_)
import System.IO
import GHC.Conc (setAllocationCounter,enableAllocationLimit)

main :: IO ()
main = 
  do setAllocationCounter 2e9
     enableAllocationLimit
     let writeToHandle h =
            for_ ([1..]::[Integer])
                 (hPutStrLn h . show)
     withFile "/dev/null" WriteMode writeToHandle
     return ()
 
 分配有点粗糙，但它仍然可以用来检测一些“失控”的计算。  
 Simon Marlow的这篇博客更详细地介绍了这一点。 

In the latest versions of GHC, it is possible to set per-thread allocation counters and limits, using setAllocationCounter and enableAllocationLimit from GHC.Conc. When a limit is set and the counter reaches 0, the thread receives an asynchronous exception. 
The counters measure allocation, and not the size of the live set. For example, this code hits the limit, despite its live set never becoming very big: 
{-# LANGUAGE NumDecimals #-}
module Main where

import Data.Foldable (for_)
import System.IO
import GHC.Conc (setAllocationCounter,enableAllocationLimit)

main :: IO ()
main = 
  do setAllocationCounter 2e9
     enableAllocationLimit
     let writeToHandle h =
            for_ ([1..]::[Integer])
                 (hPutStrLn h . show)
     withFile "/dev/null" WriteMode writeToHandle
     return ()
 
Allocation is a bit crude as a measure, but it can still be useful to detect some "out of control" computations. 
This blog post by Simon Marlow goes into more detail.

执行：显示stdout“活”(Exec : display stdout “live”)

最满意答案

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