node.js - 访问系统命令的退出代码和stderr [英] node.js - Accessing the exit code and stderr of a system command

问题描述

下面显示的代码段非常适合获取对系统命令的标准输出的访问权限。有没有办法可以修改这段代码，以便访问系统命令的退出代码和系统命令发送给stderr的任何输出？

The code snippet shown below works great for obtaining access to the stdout of a system command. Is there some way that I can modify this code so as to also get access to the exit code of the system command and any output that the system command sent to stderr?

#!/usr/bin/node
var child_process = require('child_process');
function systemSync(cmd) {
  return child_process.execSync(cmd).toString();
};
console.log(systemSync('pwd'));

推荐答案

您不需要执行异步操作。你可以保留你的execSync函数。

You do not need to do it Async. You can keep your execSync function.

尝试包装它，传递给catch（e）块的Error将包含你正在寻找的所有信息。

Wrap it in a try, and the Error passed to the catch(e) block will contain all the information you're looking for.

var child_process = require('child_process');

function systemSync(cmd) {
  try {
    return child_process.execSync(cmd).toString();
  } 
  catch (error) {
    error.status;  // Might be 127 in your example.
    error.message; // Holds the message you typically want.
    error.stderr;  // Holds the stderr output. Use `.toString()`.
    error.stdout;  // Holds the stdout output. Use `.toString()`.
  }
};

console.log(systemSync('pwd'));

如果没有抛出错误，则：

If an error is NOT thrown, then:

• 状态保证为0


• stdout是函数返回的内容


• stderr几乎肯定是空的因为它成功了

在极少数情况下，命令行可执行文件返回stderr但退出状态为0（成功），并且您想要读取它，您将需要异步功能。

In the rare event the command line executable returns a stderr and yet exits with status 0 (success), and you want to read it, you will need the async function.

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