Tiny useful scripts

epoch.js

#! node

let [epoch = Date.now()] = process.argv.slice(2);

let date = new Date(+epoch);

if (date.toString() === "Invalid Date" || date.getFullYear() === 1970) {
  epoch = +epoch * 1000;
  date = new Date(epoch);
}

let difference = Math.ceil((epoch - Date.now()) / (1000 * 60));

console.log(
  JSON.stringify(
    {
      epoch,
      utcTime: date.toUTCString(),
      localTime: date.toString(),
      relative: isNaN(difference)
        ? "-"
        : new Intl.RelativeTimeFormat().format(difference, "minutes"),
    },
    null,
    2
  )
);

jwt.mjs

#! node
// Tested with v16.17.1
import process from "node:process";
import { text } from "node:stream/consumers";
let [flag = "--help", ...args] = process.argv.slice(2);

/**
 *
 * @param token {string}
 * @param mode {string}
 */
function parse(token, mode) {
  const [header, payload, sign] = token.trim().replace("Bearer", "").split(".");
  if (mode === "--full") {
    console.log(
      JSON.stringify(
        {
          header: JSON.parse(Buffer.from(header, `base64`).toString()),
          payload: JSON.parse(Buffer.from(payload, `base64`).toString()),
          sign,
        },
        null,
        2
      )
    );
  } else {
    console.log(
      JSON.stringify(
        JSON.parse(Buffer.from(payload, `base64`).toString()),
        null,
        2
      )
    );
  }
}

if (!process.stdin.isTTY) {
  await text(process.stdin).then((token) => parse(token, flag));
} else {
  if (flag === "--help") {
    console.log(`
JWT Inspector

Usage
# Parse JWT
~ jwt --full <token>

# View payload (default)
~ jwt <token>
`);
  } else if (flag === "--payload" || flag === "--full") {
    parse(args.join(""), flag);
  } else {
    parse([flag, ...args].join(""), "--payload");
  }
}