Readline节点 JS - Javascript

Introduction

The Readline module in JS provides a way of interacting with a user through the command line, by allowing you to read input typed by the user and providing completion suggestions based on a given set of options. It is a powerful tool that can help make command-line interfaces more user-friendly.

To use the Readline module, you need to require it in your code:

const readline = require('readline');

Usage

Creating the Interface

To create a new Readline interface, you can use the createInterface() method, which takes an input and an output stream as parameters.

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});

In the example above, we have used the standard input and output streams as the input and output streams for the Readline interface.

Reading Input

To read input from the user, you can use the rl.question() method, which takes two arguments - the question to ask the user, and a callback function that will be called with the user's input.

rl.question('What is your name? ', (name) => {
    console.log(`Hello, ${name}!`);
    rl.close();
});

In the example above, we have asked the user their name, and then displayed a greeting that includes their name.

Providing Completion Suggestions

Readline also allows you to provide completion suggestions for a user when they are typing. To do this, you can use the rl.on('completer') event.

rl.on('completer', (line) => {
    const completions = ['apple', 'banana', 'cherry'];
    const hits = completions.filter((c) => c.startsWith(line));
    return [hits.length ? hits : completions, line];
});

In the example above, we have provided completion suggestions for the words "apple", "banana", and "cherry". When the user starts typing any of these words, they will be provided with a list of completion suggestions.

Conclusion

In conclusion, the Readline module in JS is a powerful tool for creating user-friendly command-line interfaces. It allows you to read input from a user, provide suggestions for completion, and more. By using this module, you can make your command-line interfaces more interactive and engaging for your users.