Why is the TTY module needed in nodejs?

Question

JavaScript

I read the documentation and did not understand why it is needed? After all, there are readline and REPL modules? Please tell me or give a description. Thank you in advance)))

Answer 1

In essence, the following happens inside the node:

const tty = require('tty');
if(tty.isatty(0)) {
  process.stdin = new tty.ReadStream();
} else {
  //init process.stdin from other stream
}

var outStream;
if(tty.isatty(1)) {
  outStream = new tty.WriteStream();
  process.stdout = outStream;
} else {
  //init process.stdout from other stream
}
if(tty.isatty(2)) {
  if(!outStream) {
    outStream = new tty.WriteStream();
  }
  process.stderr = outStream;
} else {
  //init process.stderr from other stream
}