Process Info

console.log("platform:", process.platform, "arch:", process.arch);
console.log("pid:", process.pid > 0);
console.log("execPath is absolute:", process.execPath.startsWith("/"));
console.log("node compat:", process.version, "klain:", process.versions.klain);

// emitWarning writes Node's `(node:<pid>) [<code>] <type>: <message>` line to
// stderr; the options form { type, code, detail } adds the code tag and a
// following detail line.
process.emitWarning("this is a demo warning");
process.emitWarning("legacy call site", "DeprecationWarning");
process.emitWarning("deprecated flag", { type: "DeprecationWarning", code: "DEP001", detail: "use --new-flag instead" });

process.env.GREETING = "hi";
console.log("env:", process.env.GREETING);

process.nextTick(() => {
  console.log("nextTick ran after synchronous code");
});

const start = process.hrtime.bigint();
let sum = 0;
for (let i = 0; i < 1000; i++) sum += i;
const elapsed = process.hrtime.bigint() - start;
console.log("did work, elapsed ns >= 0:", elapsed >= 0n);

// The legacy tuple form: hrtime(prev) returns the [seconds, nanoseconds] diff
// from a prior reading (nanoseconds always in [0, 1e9)).
const t0 = process.hrtime();
for (let i = 0; i < 1000; i++) sum += i;
const [ds, dns] = process.hrtime(t0);
console.log("diff nanoseconds in range:", dns >= 0 && dns < 1000000000);
console.log("uptime >= 0:", process.uptime() >= 0);

// memoryUsage() returns Node's shape. rss is the real instantaneous resident
// set; heapTotal/heapUsed report this compiler's own object heap (the C
// allocator arena by default, Boehm's heap under -mm=gc), so they are real and
// positive. external/arrayBuffers have no native off-heap analogue and are 0.
const mem = process.memoryUsage();
console.log("rss > 0:", mem.rss > 0, "heapUsed > 0:", mem.heapUsed > 0);

process.on('exit', (code: number) => {
  console.log("exiting with code", code);
});
process.exitCode = 0;
console.log("main finished");