text: console.log(process.memoryUsage());
  // {
  //     rss: 26984448, heapTotal: 4636672,
  //     heapUsed: 3637184, external: 215165, 
  //     arrayBuffers: 12146;
  // }
  
  console.log(process.cpuUsage());
  // { user: 30905, system: 27236; }
  
  console.log(process.cwd());
  // /Users/xiangjinyu/Documents/devMaterials/NodeCourse
  
  console.log(process.versions);
  // {
  //   node: '16.13.1',
  //   v8: '9.4.146.24-node.14',
  //   uv: '1.42.0',
  //   zlib: '1.2.11',
  //   ...
  // }
  
  console.log(process.arch);
  // arm64
  
  console.log(process.platform);
  // OS platform
  
  console.log(process.env.NODE_ENV);
  // environment variables ...
  
  const osUser = process.env.USERPROFILE
    ? process.env.USERPROFILE // winOS
    : process.env.HOME;       // macOS
  console.log(osUser);
  // os user info
  
  console.log(process.argv);
  // init arguments
  // [
  //   '/usr/local/bin/node',
  //   '/Users/xiangjinyu/Documents/devMaterials/NodeCourse/nodeProcess.js'
  // ];
  
  console.log(process.pid);
  // process id of current program
  
  console.log(process.uptime());
  // time from start of excution to exit of excution
  
  
  // register events on process
  process.on("exit", (code) => {
    console.log("exit with " + code);
  });
  process.on("beforeExit", (code) => {
    console.log("before exit with " + code);
  });
  console.log("program excuted");