Shows the difference between `netstat -s` captures in different files, in a nice table.

netstat-parse.js

const fs = require('fs').promises;

(async function () {
	let files = process.argv.slice(2);

	let tableColumns = {}

	for (var file of files) {
		let input = String(await fs.readFile(file))
		let lines = input.split('\n');

		for (var line of lines) {
			let match = line.match(/\b[0-9]+\b/)
			if (match && match[0]) {
				let column = line.replace(/\b[0-9]+\b/g, '').trim()
				if (!tableColumns[column]) {
					tableColumns[column] = [];
				}

				tableColumns[column].push(match[0].trim())
			}
		}
	}
  
	tableColumns = Object.entries(tableColumns).map(([k, v]) => [k, v.map((v, i, a) => {
		let diff = v - (a[i - 1] || 0);
		return [v, (diff < 0 ? '-' : '+') + Math.abs(diff)];
	})])

	tableColumns.sort((a, b) => parseInt(b[1][1][1]) - parseInt(a[1][1][1]))

	tableColumns.forEach((col) => {
		col[1] = col[1].map((itm, ind) => ind ? itm[1] : itm[0]) //itm.join(' '))
	})

	let table = Object.fromEntries(tableColumns);

	delete table['echo replies:'];
	delete table['destination unreachable:'];
	delete table['echo requests:'];

	console.table(table)
})()