Index - Node documentation

Usage in Deno

import * as mod from "node:tty";

The node:tty module provides the tty.ReadStream and tty.WriteStreamclasses. In most cases, it will not be necessary or possible to use this module directly. However, it can be accessed using:

const tty = require('node:tty');

When Node.js detects that it is being run with a text terminal ("TTY") attached, process.stdin will, by default, be initialized as an instance oftty.ReadStream and both process.stdout and process.stderr will, by default, be instances of tty.WriteStream. The preferred method of determining whether Node.js is being run within a TTY context is to check that the value of the process.stdout.isTTY property is true:

$ node -p -e "Boolean(process.stdout.isTTY)"
$ node -p -e "Boolean(process.stdout.isTTY)" | cat

In most cases, there should be little to no reason for an application to manually create instances of the tty.ReadStream and tty.WriteStreamclasses.



Represents the readable side of a TTY. In normal circumstances process.stdin will be the only tty.ReadStream instance in a Node.js process and there should be no reason to create additional instances.


Represents the writable side of a TTY. In normal circumstances,process.stdout and process.stderr will be the onlytty.WriteStream instances created for a Node.js process and there should be no reason to create additional instances.



The tty.isatty() method returns true if the given fd is associated with a TTY and false if it is not, including whenever fd is not a non-negative integer.

Type Aliases


-1 - to the left from cursor 0 - the entire line 1 - to the right from cursor