Node.js: وحدتا os و process

const os = require('os');

const cpus = os.cpus();
console.log(`CPU Number of cores: ${cpus.length}`);
console.log(`CPU Model: ${cpus[0].model}`);

const totalMem = os.totalmem();
const freeMem = os.freemem();
const usedPercent = ((totalMem - freeMem) / totalMem * 100).toFixed(1);

console.log(`Total Memory: ${(totalMem / 1024 / 1024 / 1024).toFixed(2)} GB`);
console.log(`Available memory: ${(freeMem / 1024 / 1024 / 1024).toFixed(2)} GB`);
console.log(`Memory Usage: ${usedPercent}%`);

CPU Number of cores: 8
CPU Model: Intel(R) Core(TM) i7-9700K CPU @ 3.60GHz
Total Memory: 15.88 GB
Available memory: 6.23 GB
Memory Usage: 60.7%

const os = require('os');

console.log(`Platform: ${os.platform()}`);
console.log(`System Type: ${os.type()}`);
console.log(`CPU Architecture: ${os.arch()}`);
console.log(`Hostname: ${os.hostname()}`);
console.log(`System Version: ${os.version()}`);

Platform: linux
System Type: Linux
CPU Architecture: x64
Hostname: web-server-01
System Version: #1 SMP Thu Jan 1 00:00:00 UTC 2026

const os = require('os');

const userInfo = os.userInfo();
console.log(`Username: ${userInfo.username}`);
console.log(`Home Directory: ${os.homedir()}`);
console.log(`Shell: ${userInfo.shell}`);
console.log(`Temporary Directory: ${os.tmpdir()}`);

Username: alice
Home Directory: /home/alice
Shell: /bin/bash
Temporary Directory: /tmp

const os = require('os');

const interfaces = os.networkInterfaces();
for (const [name, addrs] of Object.entries(interfaces)) {
  for (const addr of addrs) {
    if (addr.family === 'IPv4' && !addr.internal) {
      console.log(`${name}: ${addr.address} (${addr.family})`);
    }
  }
}

eth0: 192.168.1.100 (IPv4)
wlan0: 10.0.0.5 (IPv4)

function parseArgs(argv) {
  const args = {};
  for (let i = 2; i < argv.length; i++) {
    if (argv[i].startsWith('--')) {
      const key = argv[i].slice(2);
      const value = argv[i + 1] && !argv[i + 1].startsWith('--')
        ? argv[++i]
        : true;
      args[key] = value;
    }
  }
  return args;
}

const config = parseArgs(process.argv);
console.log(config);

node cli.js --env production --port 8080 --verbose

{ env: 'production', port: '8080', verbose: true }

console.log(`NODE_ENV: ${process.env.NODE_ENV || 'development'}`);
console.log(`PATH: ${process.env.PATH}`);

process.env.APP_MODE = 'production';
console.log(`APP_MODE: ${process.env.APP_MODE}`);

NODE_ENV: development
PATH: /usr/local/bin:/usr/bin:/bin
APP_MODE: production

const requiredEnv = ['DATABASE_URL', 'APP_SECRET'];
const missing = requiredEnv.filter(key => !process.env[key]);

if (missing.length > 0) {
  console.error(`Missing required environment variables: ${missing.join(', ')}`);
  process.exit(1);
}

console.log(`Working Directory: ${process.cwd()}`);
console.log(`Process ID: ${process.pid}`);
console.log(`Runtime: ${process.uptime().toFixed(0)} seconds`);

Missing required environment variables: DATABASE_URL, APP_SECRET

process.stdout.write('Please enter your name: ');

process.stdin.once('data', (data) => {
  const name = data.toString().trim();
  process.stdout.write(`Hello, ${name}!\n`);
  process.exit(0);
});

Please enter your name: Alice
Hello, Alice!

console.log('1 - Synchronize Code');

process.nextTick(() => {
  console.log('3 - nextTick callback');
});

console.log('2 - Synchronize Code');

setImmediate(() => {
  console.log('5 - setImmediate');
});

Promise.resolve().then(() => {
  console.log('4 - Promise then');
});

1 - Synchronize Code
2 - Synchronize Code
3 - nextTick callback
4 - Promise then
5 - setImmediate

const os = require('os');
const path = require('path');

const lines = ['First line', 'Second line', 'Third line'].join(os.EOL);
console.log('Escaping Line Breaks:', JSON.stringify(os.EOL));
console.log('Path separator:', os.sep);
console.log('path.join Results:', path.join('src', 'utils', 'index.js'));

Escaping Line Breaks: "\n"
Path separator: /
path.join Results: src/utils/index.js

NODE_ENV=production
DATABASE_URL=postgresql://db.example.com:5432/myapp
APP_SECRET=my-super-secret-key
APP_PORT=3000

require('dotenv').config();

console.log(`Environment: ${process.env.NODE_ENV}`);
console.log(`Database: ${process.env.DATABASE_URL}`);
console.log(`Port: ${process.env.APP_PORT}`);

Environment: production
Database: postgresql://db.example.com:5432/myapp
Port: 3000

function getEnv(key, options = {}) {
  const value = process.env[key];

  if (value === undefined) {
    if (options.required) {
      throw new Error(`Environment Variables ${key} It is necessary`);
    }
    return options.default ?? null;
  }

  if (options.type === 'number') {
    const num = Number(value);
    if (isNaN(num)) throw new Error(`Environment Variables ${key} It must be a number`);
    return num;
  }

  if (options.type === 'boolean') {
    return value === 'true' || value === '1';
  }

  return value;
}

const port = getEnv('APP_PORT', { default: 3000, type: 'number' });
const debug = getEnv('DEBUG', { default: false, type: 'boolean' });
const dbUrl = getEnv('DATABASE_URL', { required: true });

const os = require('os');

function parseArgs(argv) {
  const args = {};
  for (let i = 2; i < argv.length; i++) {
    if (argv[i].startsWith('--')) {
      const key = argv[i].slice(2);
      const value = argv[i + 1] && !argv[i + 1].startsWith('--')
        ? argv[++i] : true;
      args[key] = value;
    }
  }
  return args;
}

function formatBytes(bytes) {
  const units = ['B', 'KB', 'MB', 'GB'];
  let i = 0;
  let size = bytes;
  while (size >= 1024 && i < units.length - 1) {
    size /= 1024;
    i++;
  }
  return `${size.toFixed(2)} ${units[i]}`;
}

function getSystemInfo() {
  const cpus = os.cpus();
  const totalMem = os.totalmem();
  const freeMem = os.freemem();
  return {
    hostname: os.hostname(),
    platform: os.platform(),
    arch: os.arch(),
    osType: os.type(),
    cpuModel: cpus[0].model,
    cpuCores: cpus.length,
    totalMemory: formatBytes(totalMem),
    freeMemory: formatBytes(freeMem),
    memUsage: ((totalMem - freeMem) / totalMem * 100).toFixed(1) + '%',
    uptime: (os.uptime() / 3600).toFixed(1) + ' hours'
  };
}

function getEnvInfo(keys) {
  const result = {};
  for (const key of keys) {
    result[key] = process.env[key] || '(Not set)';
  }
  return result;
}

function printReport(sys, env) {
  const sep = '='.repeat(48);
  console.log(`\n${sep}`);
  console.log('  System Diagnostic Report');
  console.log(`${sep}`);
  console.log(`  Hostname     : ${sys.hostname}`);
  console.log(`  Platform       : ${sys.platform} / ${sys.arch}`);
  console.log(`  Operating System   : ${sys.osType}`);
  console.log(`  CPU        : ${sys.cpuModel}`);
  console.log(`  CPU Number of cores : ${sys.cpuCores}`);
  console.log(`  Total Memory     : ${sys.totalMemory}`);
  console.log(`  Available memory   : ${sys.freeMemory}`);
  console.log(`  Memory Usage : ${sys.memUsage}`);
  console.log(`  Runtime   : ${sys.uptime}`);
  console.log(`${sep}`);
  console.log('  Environment Variables');
  console.log('-'.repeat(48));
  for (const [key, val] of Object.entries(env)) {
    console.log(`  ${key.padEnd(20)} : ${val}`);
  }
  console.log(`${sep}\n`);
}

const args = parseArgs(process.argv);
const envKeys = args.envKeys
  ? args.envKeys.split(',')
  : ['NODE_ENV', 'HOME', 'PATH', 'SHELL'];
const sys = getSystemInfo();
const env = getEnvInfo(envKeys);
printReport(sys, env);

node syscheck.js --envKeys NODE_ENV,APP_PORT,DATABASE_URL

================================================
  System Diagnostic Report
================================================
  Hostname     : web-server-01
  Platform       : linux / x64
  Operating System   : Linux
  CPU        : Intel(R) Xeon(R) CPU E5-2680 v4
  CPU Number of cores : 8
  Total Memory     : 15.88 GB
  Available memory   : 6.23 GB
  Memory Usage : 60.7%
  Runtime   : 72.5 hours
================================================
  Environment Variables
------------------------------------------------
  NODE_ENV             : production
  APP_PORT             : (Not set)
  DATABASE_URL         : (Not set)
================================================