Node.js process.connected属性

process.connected 属性是 process 模块的内置属性，用于子进程检查它是否连接到父进程。

语法:

process.connected

返回值: 如果该进程是由另一个进程生成的，则process.connected属性将返回true，表示这两个进程已连接；否则，返回false。

示例1: 如果进程已连接，则process.connected将返回true。

Parent.js

// Require fork method from child_process  
// to spawn child process 
const fork = require('child_process').fork; 
  
// Child process file 
const child_file = 'Child.js'; 
  
// Spawn child process 
const child = fork(child_file);

Child.js

console.log('In Child.js') 
  
// If it is connected 
if (process.connected) { 
  
    // Print messages 
    console.log("Child.js is connected"); 
} else { 
  
    // Print messages 
    console.log("Child.js is disconnected"); 
}

请使用以下命令运行 Parent.js 文件：

node Parent.js

输出：

In Child.js
Child.js is connected

示例2： 如果进程断开连接，则process.connected将返回false。

Parent.js

// Require fork method from child_process  
// to spawn child process 
const fork = require('child_process').fork; 
  
// Child process file 
const child_file = 'Child.js'; 
  
// Spawn child process 
const child = fork(child_file);

Child.js

console.log('In Child.js') 
  
// Disconnect the process 
process.disconnect(); 
  
// If it is connected 
if (process.connected) { 
  
    // Print messages 
    console.log("Child.js is connected"); 
} else { 
  
    // Print messages 
    console.log("Child.js is disconnected"); 
}

使用以下命令运行 Parent.js 文件：

node Parent.js

输出：

In Child.js
Child.js is disconnected

参考： https://nodejs.org/api/process.html#process_process_connected