getProcessUsage.ts

import { exec } from 'node:child_process';
import os from 'node:os';

export function getProcessUsage() {
	let command = '';

	switch (os.platform()) {
		case 'darwin': command = `ps -p ${process.pid} -o %cpu,rss`; break;
		case 'linux': command = `ps -p ${process.pid} -o %cpu,rss`; break;
		default: return Promise.reject(new Error('Unsupported platform!'));
	}

	const formatBytes = (bytes: number) => {
		const sizes = ['B', 'KB', 'MB', 'GB', 'TB'];

		if (bytes === 0) return '0MB';

		const i = Math.floor(Math.log(bytes) / Math.log(1024));
		return parseFloat((bytes / Math.pow(1024, i)).toFixed(2)) + sizes[i];
	};

	const formatCpu = (cpu: number, numCores?: number) => {
		return numCores ? `${(cpu / numCores).toFixed(2)}%` : `${cpu.toFixed(2)}%`;
	};

	return new Promise<{ cpuUsage: string; memoryUsage: string; coreUsage: string; }>((resolve, reject) => {
		exec(command, (error, stdout, stderr) => {
			if (error) return reject(error);
			else if (stderr) return reject(new Error(stderr));

			const lines = stdout.trim().split('\n');
			if (lines.length < 2) return reject(new Error('Unexpected output!'));

			const data = lines[1].trim().split(/\s+/);
			const numCores = os.cpus().length;

			resolve({
				cpuUsage: formatCpu(parseFloat(data[0]), numCores),
				coreUsage: formatCpu(parseFloat(data[0])),
				memoryUsage: formatBytes(parseInt(data[1]) * 1024),
			});
		});
	});
}