Learn how to use standard input and standard output, using the global object process.

Process ID (pid)

It is important to understand that when you run a script, it is treated as its own process. You may have many processes running simultaneously on your machine, and each has its own unique identification called a Process ID (pid). You will learn how you can pass over responsibility to a separate process later on but, for now, here is how you can output the Process ID.

console.log(`This process is pid ${}`);

What about adding a callback when the current process has ended? When the script exits, this will fire.

process.on('exit', (code) => {
  console.log(`The process has now finished, exiting with code: ${code}`);

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