tty（终端）

tty 模块提供 tty.ReadStream 和 tty.WriteStream 类。 在大多数情况下，没有必要或可能直接使用此模块。 可以使用以下方法访问它：

const tty = require('tty');

当 Node.js 检测到它附加了文本终端（TTY）时，默认情况下，process.stdin 将被初始化为 tty.ReadStream 的一个实例，process.stdout 和 process.stderr 将被初始化为 tty.WriteStream 的实例。 判断 Node.js 是否在 TTY 上下文中运行的首选方法是检查 process.stdout.isTTY 属性的值是否为 true：

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

在大多数情况下，应用程序应该几乎没有理由手动创建 tty.ReadStream 和 tty.WriteStream 类的实例。

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

const tty = require('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 of tty.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)"
true
$ node -p -e "Boolean(process.stdout.isTTY)" | cat
false

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